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EDITORIAL REVIEW COMMITTEE P.W. Taubenblat, Chairman I.E. Anderson, FAPMI T. Ando S.G. Caldwell S.C. Deevi D. Dombrowski J.J. Dunkley Z. Fang B.L. Ferguson W. Frazier K. Kulkarni, FAPMI K.S. Kumar T.F. Murphy J.W. Newkirk P.D. Nurthen J.H. Perepezko P.K. Samal H.I. Sanderow D.W. Smith, FAPMI R. Tandon T.A. Tomlin D.T. Whychell, Sr., FAPMI M. Wright, PMT A. Zavaliangos INTERNATIONAL LIAISON COMMITTEE D. Whittaker (UK) Chairman V. Arnhold (Germany) E.C. Barba (Mexico) P. Beiss (Germany) C. Blais (Canada) P. Blanchard (France) G.F. Bocchini (Italy) F. Chagnon (Canada) C-L Chu (Taiwan) H. Danninger (Austria) U. Engström (Sweden) N.O. Grinder (Sweden) S. Guo (China) F-L Han (China) K.S. Hwang (Taiwan) Y.D. Kim (Korea) G. Kneringer (Austria) G. L’Espérance, FAPMI (Canada) H. Miura (Japan) C.B. Molins (Spain) R.L. Orban (Romania) T.L. Pecanha (Brazil) F. Petzoldt (Germany) S. Saritas (Turkey) G.B. Schaffer (Australia) Y. Takeda (Japan) G.S. Upadhyaya (India) Publisher C. James Trombino, CAE
[email protected] Editor-in-Chief Alan Lawley, FAPMI
[email protected] Managing Editor James P. Adams
[email protected] Contributing Editor Peter K. Johnson
[email protected] Advertising Manager Jessica S. Tamasi
[email protected] Copy Editor Donni Magid
[email protected] Production Assistant Dora Schember
[email protected] President of APMI International Nicholas T. Mares
[email protected] Executive Director/CEO, APMI International C. James Trombino, CAE
[email protected]
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powder metallurgy Contents 2 5 9 13 19 25
44/3 May/June 2008
Editor's Note PM Industry News in Review PMT Spotlight On … Stephen P. Madill Consultants’ Corner John A. Shields, Jr. Innovations Drive PM's Growth Prospects Peter K. Johnson Exhibitor Showcase: PM2008 World Congress
GLOBAL REVIEW 41 Powder Metallurgy in Denmark, Finland, and Sweden O. Grinder and J. Tengzelius
ENGINEERING & TECHNOLOGY 57 Stainless Steel AISI Grades for PM Applications C.T. Schade, J.W. Schaberl and A. Lawley
69 Control of Defects in Powder Injection Molded Aluminum Matrix Composites F. Ahmad
RESEARCH & DEVELOPMENT 77 Universal Hardness Test to Characterize PM Steels G.F. Bocchini, B. Rivolta and R. Gerosa
85 86 87 88
DEPARTMENTS Meetings and Conferences APMI Membership Application PM Bookshelf Advertisers’ Index Cover: Diamond core drills. Photo courtesy Atlas Copco Craelius AB, Sweden.
The International Journal of Powder Metallurgy (ISSN No. 0888-7462) is a professional publication serving the scientific and technological needs and interests of the powder metallurgist and the metal powder producing and consuming industries. Advertising carried in the Journal is selected so as to meet these needs and interests. Unrelated advertising cannot be accepted. Published bimonthly by APMI International, 105 College Road East, Princeton, N.J. 08540-6692 USA. Telephone (609) 4527700. Periodical postage paid at Princeton, New Jersey, and at additional mailing offices. Copyright © 2008 by APMI International. Subscription rates to non-members; USA, Canada and Mexico: $95.00 individuals, $220.00 institutions; overseas: additional $40.00 postage; single issues $50.00. Printed in USA by Cadmus Communications Corporation, P.O. Box 27367, Richmond, Virginia 23261-7367. Postmaster send address changes to the International Journal of Powder Metallurgy, 105 College Road East, Princeton, New Jersey 08540 USA USPS#267-120 ADVERTISING INFORMATION Jessica Tamasi, APMI International INTERNATIONAL 105 College Road East, Princeton, New Jersey 08540-6692 USA Tel: (609) 452-7700 • Fax: (609) 987-8523 • E-mail:
[email protected]
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EDITOR’S NOTE
T
he PM2008 World Congress Show Issue is your preview to the industry’s largest international technical conference and trade exhibition. Held sexennially in North America, the congress site is America’s capital city, Washington, D.C., a convenient location for delegates from North America and overseas. The technical program embraces 95 sessions featuring close to 300 speakers, six special interest programs on timely and diverse topics, an extensive poster program, the presentation of the PM Design Excellence Awards, and entries in the PM Metallography Competition. The exhibition features more than 100 companies displaying the latest in PM equipment, powders, products, and services. The Exhibitor Showcase in this issue includes profiles of these companies. In addition, the 2008 International Conference on Tungsten, Refractory & Hardmaterials VII will be co-located and run concurrently with the World Congress. The technical program includes more than 100 presentations in 38 technical sessions addressing recent developments focusing on the processing, microstructure, properties, and applications of these materials. In keeping with tradition, the Show Issue includes Peter Johnson’s annual technology review of the PM industry, based on input from MPIF-member companies. Notwithstanding macroeconomic and increasing marketplace challenges, the PM industry is responding by investing in new technology focusing on metal powders, equipment, and processes. We welcome John Shields as a new contributor to the “Consultants’ Corner.” A consummate professional in refractory metals, John responds to readers’ questions concerning the effect of dew point on the sintering of molybdenum, tungsten, and their alloys, and the commercial status of activated sintering of these materials. The Show Issue reflects topical diversity with in-depth articles on AISI grades of stainless steels for PM applications, defect control in MIM aluminum matrix composites, and the application of a universal hardness test to characterize and differentiate between sintered steels derived from nominally equivalent powders. In their “Global Review,” Tengzelius and Grinder pen a comprehensive review of the PM industry in Denmark, Finland, and Sweden. Coverage includes powder production, pore-free ferrous products, diamond and superhard materials, the manufacture of consolidation equipment, and R&D activities. The front cover displays diamond core drills manufactured by Atlas Copco Craelius AB, Sweden.
Alan Lawley Editor-in-Chief
Regular readers of the “Editor’s Note” know that I frequently include commentary on engineering and its importance to society, from the perspective of the National Academy of Engineering (NAE). Based on input from a diverse international group of engineers, scientists, and medical doctors, NAE recently released a list of 14 Grand Challenges for engineering in the 21st century: • Make Solar Energy Affordable • Engineer Better Medicines • Provide Access to Clean Water • Reverse-Engineer the Brain • Provide Energy from Fusion • Enhance Virtual Reality • Restore and Improve Urban Infrastructure • Prevent Nuclear Terror • Develop Carbon Sequestration Methods • Advance Personalized Learning • Advance Health Informatics • Secure Cyberspace • Manage the Nitrogen Cycle • Engineer Tools for Scientific Discovery Does the list surprise you? Clearly these engineering grand challenges mandate a global approach for success. Materials, including powders and particulates, are intrinsic to a number of the cited areas. I solicit and welcome reader response and opinion on this topic.
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Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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PM INDUSTRY NEWS IN REVIEW The following items have appeared in PM Newsbytes since the previous issue of the Journal. To read a fuller treatment of any of these items, go to www.apmiinternational.org, login to the “Members Only” section, and click on “Expanded Stories from PM Newsbytes.”
Automotive-Supplier Strike Impacts PM Industry The UAW strike against American Axle & Manufacturing Inc. (AAM), Detroit, Mich., which began February 26, is sending ripples through the North American automotive industry, idling 20 OEM and auto-parts plants. As of March 6, GM V-8 engine plants stopped taking delivery of parts, a PM parts supplier reports. Chinese Company to Invest in Canadian Tungsten Mine Hunan Nonferrous Metals Corporation in China will acquire 13.4 million shares of North American Tungsten Corporation (NTC) in a private placement, representing nine percent of the company. The transaction, subject to approval by the TSX Venture Exchange, will raise approximately $19.4 million for developing NTC’s Mactung tungsten project in the Yukon.
Austria, will hold the 17th Plansee Seminar on high-performance PM materials May 25–30, 2009. The program, featuring oral and poster presentations, will cover metals, composites, and hardmaterials. Results Surge OM Group, Inc., Cleveland, Ohio, posted net 2007 sales of $1.02 billion, compared with $660.1 million in 2006. Gross profit for the specialty chemicals producer rose sharply to $313.2 million. Filtration Systems for Liquid/ Solid Separation Mott Corporation, Farmington, Conn., reports that its porous metal HyPulse filtration systems are replacing leaf filters, cyclones, and filter presses in refineries, special chemical processing, and pharmaceutical processing. The filtration systems provide solutions without using moving parts.
Laser Sintering Sales Increase Worldwide sales of laser sintering equipment at EOS, Munich, Germany, increased 14 percent in fiscal 2006–07 to 59.7 million (about $93 million). The company gained almost 50 new customers and experienced strong growth in Germany, Austria, and Switzerland.
Global Network Launched for PM Infiltrant Ultra Infiltrant, Carmel, Ind., has established an international network to sell, market and manufacture its wrought wire infiltration system. The network includes ACuPowder International, LLC, Union, N.J.; Luvata, London, U.K.; and Prince & Izant, Cleveland, Ohio.
Plans for 17th Plansee Seminar Announced The Plansee Group, Reutte,
Funding for Nanotechnology Development The Pennsylvania NanoMaterials
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
Commercialization Center, Pittsburgh, Pa., has approved the proposals of three Pennsylvaniabased companies to fund projects aimed at using nanotechnology to develop new products and processes. The projects, with funding valued at over $750,000, cover a spectrum sensor chip using nanoimprint lithography, supercapacitors using tunable nanoporous carbon electrodes, and developing semi-continuous processing for organic photovoltaic devices. Metal Powder Company Sold Carpenter Powdered Products, Inc., a subsidiary of Carpenter Technology Corporation, Wyomissing, Pa., has purchased the assets and business of UltraFine Powder Technology Inc., a private company in Woonsocket, R.I. UltraFine produces gas-atomized powders from ferrous, nickel, cobalt and copper alloys, and stainless steel powder for metal injection molding. Clayton to Receive Lifetime Achievement Award Arlan J. Clayton has been selected as the first recipient of MPIF’s Kempton H. Roll PM Lifetime Achievement Award. He will receive the award on June 9 at the Opening General Session of the 2008 World Congress on Powder Metallurgy & Particulate Materials, June 8–12, in Washington, D.C. ijpm
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PM INDUSTRY NEWS IN REVIEW
Firms Partner to Develop PM Applications MaxTek LLC, Milldale, Conn., has named PRIMA Problem Solving, State College, Pa., as its exclusive agent in the technical development of applications in the international PM industry for its super-abrasive machining equipment. MaxTek designs and sells machining systems for the aerospace, power gen-
eration, automotive, compressor, and medical industries.
titanium alloy and niobium powders and superalloys.
Ametek Buys Specialty Powder Producer Ametek, Inc., Paoli, Pa., has acquired Reading Alloys (RA), Robesonia, Pa., for an undisclosed amount. RA, formerly a subsidiary of KB Alloys, Inc., makes titanium master alloys,
Höganäs AB First Quarter Sales Up First-quarter 2008 sales at Höganäs AB, Sweden, increased 12 percent to about $269 million (1,583 MSEK). Income after taxes increased 15 percent to about $25 million (145 MSEK). ijpm
PURCHASER & PROCESSOR
Powder Metal Scrap (800) 313-9672 Since 1946
Ferrous & Non-Ferrous Metals Green, Sintered, Floor Sweeps, Furnace & Maintenance Scrap
1403 Fourth St. • Kalamazoo, MI 49048 • Tel: 269-342-0183 • Fax: 269-342-0185 Robert Lando E-mail:
[email protected]
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SPOTLIGHT ON ...
STEPHEN P. MADILL, PMT Education: BS Communications, Wingate University, 1997 Why did you study powder metallurgy/particulate materials? My study of PM began out of necessity when I joined Engineered Sintered Components (ESC) fresh from college. I was fascinated by what I learned during my studies and their application. The constant challenges arising in PM are what I continue to enjoy today. When did your interest in engineering/ science begin? My interest in science started when I was in high school (Amherst, New York). I had excellent teachers and they made the several science courses both interesting and challenging. This interest continued in college and I took extra courses in the basic science disciplines which were not required for my degree major. What was your first job in PM? What did you do? After college my first job was in the customer service group at ESC. Primarily, I handled day-to-day customer interactions. Describe your career path, companies worked for, and responsibilities. With ESC, I worked in various positions within the company: customer service, production control, and outside sales. The outside sales position dealt primarily with Japanese automotive companies, including Toyota, Honda, and Nissan. I left ESC for a short period to join North American Höganäs as an account manager. Here I was responsible for dedicated PM customers. The geographic areas I covered included the Southeast U.S., Canada, and New England. I was then recruited back to ESC to become sales & marketing manager. Since returning to this position, I have added management responsibilities for a section of the manufacturing facility.
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
What gives you the most satisfaction in your career? I enjoy troubleshooting and problem solving. I derive satisfation from seeing my ideas lead to problem solving. I enjoy the opportunity to help customers and appreciate the many friendships I have developed with customers, co-workers, and suppliers during my career. List your MPIF/APMI activities. I am currently chairman of the Southeast Chapter of APMI International. I am also a member of the committee organizing PM technical sessions at the 2008 SAE conference. What major changes/trend(s) in the PM industry have you seen? I would cite the latest trends in business being sourced offshore, and the continued increase in the sale of vehicles that use decreasing numbers of PM parts. As this happens, we will see ultra-competitive markets for PM components which will make it increasingly difficult to generate healthy profits. Kaizen and VA/VE ideas will become more and more important to both PM component and powder companies alike. Why did you choose to pursue PMT certification? I chose to take the PMT certification examination in order to see how my knowledge compared with what the industry expected. Also, the general stereotype of sales people is that they are not technical. I have always felt that I excelled in technical discussions and the PMT certification would help me overcome this stereotype image. Sales & Marketing Manager Engineered Sintered Components 250 Old Murdock Road Troutman, North Carolina 28166 Phone: 704-528-7500 ext. 7507 Fax: 704-528-7529 E-mail:
[email protected]
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SPOTLIGHT ON ...STEPHEN P. MADILL, PMT
How have you benefited from PMT certification in your career? PMT certification has helped by giving me a target to shoot for as I progress in professional development. By pushing myself to learn more about PM, I believe I am more knowledgeable and helpful to our customers.
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What are your current interests, hobbies, and activities outside of work? Outside of work, I am a sports freak. Golf is really the only sport I play anymore. I watch any sporting event, but I mostly enjoy attending sporting events of any kind, from football games to NASCAR races. I also enjoy traveling. ijpm
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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CONSULTANTS’ CORNER
JOHN A. SHIELDS, JR.* Q A
How important is dew point when sintering molybdenum, tungsten and their alloys in a hydrogen atmosphere? PM molybdenum and tungsten are usually pressed and sintered to make ingots for mill products rather than for pressed-and-sintered parts. The ingots are typically produced in a cold isostatic press (CIP) without binders or powder lubricants, and sintered in hydrogen atmosphere furnaces. Dew-point control during sintering is important. The metals are chemically similar, so I will use molybdenum to illustrate most of the points I want to make. Similar arguments apply to tungsten. Dew point indirectly measures the concentration of water vapor in the hydrogen gas. This water comes from several sources: residual water from the hydrogen-production process; water produced by reaction of hydrogen with residual oxygen and oxides present in the material and the sintering furnace; and water produced by the reaction of hydrogen with oxygen resulting from air leaks in the system. Three chemical equilibria must be controlled to produce a well-sintered product. One is the equilibrium between hydrogen and oxide films on the powder surfaces: 1/2 MoO2 + H2 ↔ 1/2 Mo + H2O
(1)
This reaction converts the oxygen in molybdenum oxide into water vapor, reducing the oxide to metal and producing clean surfaces for sintering. The second equilibrium is between water vapor in the gas and oxygen adsorbed on surfaces: O(adsorbed) + H2 ↔ H2O
(2)
The third equilibrium is between water vapor in the gas and oxygen dissolved in the metal itself: O(Mo) + H2 ↔ H2O
(3)
The hydrogen used to sinter molybdenum and tung-
sten has a low dew point, because it usually comes from a liquid hydrogen tank or a hydrogen generator that dehumidifies the gas to a low water content. Thermodynamic calculations indicate that hydrogen will react with adsorbed oxygen and oxide films, since both molybdenum and tungsten oxide are readily reduced chemically to metal, even when the hydrogen contains significant amounts of water. Hydrogen with a dew point of 25°C can reduce molybdenum oxide to molybdenum metal at temperatures >440°C. Hydrogen, with its high mobility, readily diffuses through pores in the pressed powder and reacts with molybdenum oxide and oxygen in the ingot to form water vapor. The practical problem is not getting the hydrogen to react with the oxygen, but removing the water molecules formed by the reaction. They are much larger than hydrogen molecules and much less mobile. The sintering process must allow time for the molecules to diffuse out via the interconnected pores and be carried away in the gas stream. It must accomplish this task before sintering starts and before pore closure occurs, trapping water vapor in the pores. Manufacturers employ proprietary sintering cycles tailored to the needs of their furnaces and components being sintered, to manage this process of removing water vapor. The equilibrium coefficient for reaction (3) shows why it is important to remove the water vapor. Since the molybdenum in the reaction is a pure metal, the constant can be written as: K=
ρ (H2O) ————— a (O(Mo))
(4)
where ρ (H2O) = partial pressure of water vapor, and
*Mill Creek Materials Consulting, 4457 Brooks Road, Cleveland, Ohio 44105-6053, USA; Phone: 216-701-4697; E-mail:
[email protected]
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CONSULTANTS’ CORNER
a(O(Mo)) = activity of oxygen dissolved in molybdenum (approximated by its atomic fraction) Since K is, by definition, a constant, any increase in the water content of the hydrogen gas will result in dissolution of oxygen in the metal. Oxygen in molybdenum and tungsten segregates to grain boundaries, and dramatically raises the ductile–brittle transition temperatures (DBTT)—an undesirable event. Producers strive to keep the oxygen content of their sintered material <50 ppm. For typical molybdenum sintering temperatures (~1,700°C), this means the hydrogen dew point must be <-25°C. This further reinforces the importance of managing the process in its early stages when water is created by reaction of hydrogen with the input material, sintering has not yet begun to close off the pores, and the diffusion rate of oxygen in molybdenum is low. Obtaining and maintaining a low dew point is not easy. In addition to the contribution from oxide films and adsorbed oxygen on the powder surface in the pressed component and the internal surfaces of the furnace, air can leak through faulty seals and joints in the gas-piping system and the furnace and increase the water content of the gas. It is of no value to use hydrogen with a dew point of -50°C at its source, if the dew point is 25°C when it enters the furnace because of air leaks. The gas will reduce oxide films and remove adsorbed oxygen, but it will not protect the sintered components from retaining oxygen in solution. In this case, increasing the hydrogen flow rate might reduce oxide films to metal more rapidly, but it will do nothing to lower the oxygen content of the metal. Alloys such as TZM (Mo-0.5 w/o Ti-0.08 w/o Zr0.05 w/o C) that contain reactive metals and carbon present special problems. They are produced by mixing pure molybdenum powder with alloy constituents from a variety of sources (e.g., pure metal powders, carbides, hydrides, or graphite). During sintering, the metals and the carbon can react with water vapor in the gas to produce oxide inclusions and lower the carbon content of the sintered solid compared with that of the powder mix. It is relatively straightforward to add sacrificial carbon to the mix to accommodate carbon loss, but the inclusion problem is intractable. Even if the gas entering the sintering furnace contains no water, the oxygen present on the powder surfaces will react with the alloy additions. ASTM specifications for molybdenum products1,2 recognize this problem, allowing
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CONSULTANTS’ CORNER
up to 300 ppm oxygen in TZM alloy (type 364), compared with a maximum oxygen content in PM molybdenum (type 361) of 70 ppm. As noted previously, manufacturers of molybdenum mill products routinely produce pure molybdenum with oxygen contents well below this maximum. PM TZM alloy typically contains oxygen in amounts not far below the 300 ppm maximum; this is evidence of how difficult it is to eliminate reaction between the alloy additions, especially zirconium, and oxygen. Unlike pure tungsten and molybdenum, tungsten heavy alloys (WHAs) containing 90–95 w/o W and mixtures of iron, nickel, copper, and other minor elements, benefit from controlled humidification of the hydrogen sintering atmosphere. They are usually produced by mixing pure metal constituents with a lubricant or binder. Before sintering, the binder must be removed at relatively low temperatures. The effectiveness of the debinding step is improved by humidifying the hydrogen atmosphere so that the water vapor reacts with the binders and lubricants, removing them more efficiently. WHAs are liquid-phase sintered. The lower melting components dissolve and redistribute tungsten to form large (~40 µm) tungsten spheres bound by the liquid phase made up of the alloy additions and some tungsten. There is evidence that humidifying the atmosphere during the liquid sintering phase of the process is beneficial because it can reduce porosity in the sintered product. The liquid-alloy phase has a high solubility for oxygen, dissolving adsorbed oxygen, oxygen contained in oxide films, and oxygen in solution in the tungsten. If the hydrogen has a low dew point, it will degas the liquid phase. If the liquid is high in oxygen, or the components being sintered are large, the degassing reaction may not have time to reach equilibrium before the sintering cycle is complete. In this case the remaining oxygen is rejected, creating porosity on solidification. Increasing the dew point raises the equilibrium oxygen content in the solidifying liquid, suppressing gas rejection and pore creation. Interactions between the furnace atmosphere and the furnace itself are also important. Furnace manufacturers who build high-temperature hydrogen furnaces are well aware of the need to employ stable refractory materials in the hot zone. Alumina will suffice for the sintering of molybdenum and WHAs. Tungsten requires sintering temperatures >2,000°C, which can undermine the stability of alumina if the hydrogen gas dew point is low enough. Using a
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CONSULTANTS’ CORNER
lower-purity refractory when rebuilding furnaces, or failing to maintain proper cleanliness when rebuilding, introduces easily reduced oxides. These impurity constituents can be redistributed to cooler regions of the furnace and appear as stalactites, or may even contaminate the materials being sintered. What is the commercial status of activated sintering applied to molybdenum and tungsten? Small additions of nickel do “magical things” to the sintering behavior of molybdenum and tungsten. Instead of requiring sintering temperatures of 1,700°C–2,200°C to attain 95% of the porefree density, a few tenths w/o nickel powder added to molybdenum or tungsten powder can activate the sintering process, promoting consolidation to full density at temperatures hundreds of degrees Celsius lower. Why not take advantage of the phenomenon, design more-efficient and lower -cost processes, and make molybdenum and tungsten parts via this technique? The binary phase diagrams of nickel or iron (another activating species) and molybdenum or tungsten exhibit eutectics at temperatures much lower than the normal sintering temperatures. Because of this, early investigators postulated that liquid grain-boundary films were the reason these activators were so effective. Enhanced solid-state diffusion at grain boundaries has also been proposed to explain the effect. Theoretical work has also continued to expand understanding. At PowderMet2007 German discussed the atomistic modeling of the effects of iron on tungsten {100} crystal faces. Calculations showed that iron readily adsorbs on tungsten {100} faces and promotes movement of tungsten through the iron monolayer. Other authors have performed Auger electron spectroscopy of materials consolidated by activated sintering, and confirmed that grain boundaries are enriched in the activating species. Boundary enrichment brings with it practical problems. Because of the tendency for eutectic formation, tungsten and molybdenum sintered with activators are hot short. Thus, standard processing to develop ductility in tungsten and molybdenum, with controlled reductions starting at high temperatures, is not an option. Boundary enrichment also increases the DBTT of the sintered product, so the materials are more fragile than standard sintered materials at ambient temperatures. Some molybdenum electrical and electronic com-
Q A
16
ponents do not require high strength and may not even need to have high ductility. These might be candidates for pressed-and-sintered parts that use activated sintering. Semiconductor heat sinks are one such application. Many tons of molybdenum powder are consumed each year to produce pressed-and-sintered heat sinks for low-power electrical devices, typically in rectifier circuits for consumer appliances. The heat sinks must be sintered at high temperatures to attain optimum properties, increasing capital and processing cost. Activated sintering offers reduced manufacturing costs, but brings with it substantial changes in the physical properties of the material as well. Heat removal and electrical conduction are both important factors in these parts; activators reduce these properties to unacceptable levels. If the activator content is increased to several w/o, instead of tenths of w/o, one creates the tungsten heavy alloys. Here there is no attempt to activate solid-state sintering. Instead, the alloy is designed to produce significant volume fractions of low-melting components during sintering, and to use this liquid phase to redistribute tungsten and produce a composite microstructure. The iron–nickel–tungsten liquid acts as a binder after solidification, producing a tungsten-base material with significant ductility and strength. Despite the hurdles to commercial application, activated sintering remains a much-studied subject. It is an intriguing materials phenomenon, providing fertile ground for academic research in both the experimental and modeling communities. Its potential for allowing the processing of molybdenum and tungsten at “normal” temperatures also makes it intriguing to the manufacturing community. Its time has not yet arrived in the commercial arena, but well may do so if these R&D efforts pay off. I acknowledge with gratitude the insight and assistance of Dr. Leonid Shekhter in the discussion of hydrogen dew point effects, and for providing calculational support in the examples cited. 1. “Standard Specification for Molybdenum and Molybdenum Alloy Plate, Sheet, Strip, and Foil,” ASTM B386-03, American Society for Testing and Materials, Conshohocken, PA, 2003. 2. “Standard Specification for Molybdenum and Molybdenum Alloy Bar, Rod, and Wire,” ASTM B387-90 (Reapproved 2001), American Society for Testing and Materials, Conshohocken, PA, 2001. ijpm
Readers are invited to send in questions for future issues. Submit your questions to: Consultants’ Corner, APMI International, 105 College Road East, Princeton, NJ 08540-6692; Fax (609) 987-8523; E-mail:
[email protected]
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Focusing on Solutions
At ACuPowder, we’ve created a unique “focused approach” designed to provide innovative solutions to our customers’ problems. We’re more than just a supplier of goods, we’re a provider of ideas. We work closely with customers to assess needs and create workable responses, tailored exactly to meet their objectives. Our knowledgeable support staff looks beyond the ordinary to develop programs that deliver extraordinary results. With more than 80 years industry experience, ACuPowder welcomes even the toughest assignments. Put us to the test. You’ll quickly learn that we are totally focused on you. So depend on ACuPowder as your “one-stop source” for Copper, Tin, Bronze, Brass, Copper Infiltrant, Bronze Premixes, Antimony, Bismuth, Chromium, Manganese, MnS+ Nickel, Silicon, Graphite and P/M Lubricants. We’re ready to serve your needs.
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ANNUAL TECHNOLOGY REVIEW
INNOVATIONS DRIVE PM'S GROWTH PROSPECTS Peter K. Johnson*
Faced with macroeconomic and marketplace challenges, the powder metallurgy (PM) industry is investing in new technology. Developments in metal powders, equipment, and processes are leading the way to higher-performance PM products and new applications. Counteracting rising commodity prices, metal powder makers are offering materials with lower alloy contents.
NEW METAL POWDERS Hoeganaes Corporation, Cinnaminson, New Jersey, is promoting AncorMax 200 to achieve a density of 7.5 g/cm3 by single pressingand-sintering without heating the powder, reports K.S. (Sim) Narasimhan, FAPMI, vice president and chief technology officer. Instead of heating the powders, the dies are heated to 90°C (194°F). Increases in densities of 0.15 to 0.2 g/cm3 can be attained compared with the standard lubricant system. The company recently finished a project on surface densification of gears to pore-free density with a core density of 7.5 g/cm3. Kobe Steel, Ltd., Japan, has developed a new material that increases the fatigue limit of powder forged (PF) connecting rods by 30%, reports Satoshi Masuhara, manager, technology section, steel powder division. The material controls the size and shape of micropores in the PF rods. Kobe has also introduced a new high-speed machining additive, KSX, for complicated PM parts. Compared to MnS, it improves tool life in drilling and turning, and does not generate soot during sintering. North American Höganäs (NAH), Hollsopple, Pennsylvania, continues to work on leaner versions of prealloyed chromium and nickel–molybdenum grades of steel powders, reports David Milligan, manager of technology. A new prealloyed nickel–molybdenum grade is a less expensive alternative to sinter-hardening grades such as FLC4608. Prealloyed chromium grades can achieve sinter-hardened tensile strengths >1,200 MPa (174,000 psi). NAH is researching lubricants that provide green densities of 7.3 to 7.4 g/cm3. Quebec Metal Powders Ltd. (QMP), Sorel-Tracy, Québec, Canada, is aiming R&D at new materials and process technologies to achieve higher densities after compacting and/or sintering, says Francois Chagnon, principal scientist. Additional programs on base powders, additives, and blending technology are aimed at improving the dimensional consistency of premixes. For example, substituting synthetic graphite for natural graphite reduced variation in dimensional change by 61% and provided tighter tolerances. QMP soft magnetic composite (SMC) powders are finding new use in three-dimensional designs for electrical applications. Replacing twodimensional steel laminations, the new designs require ferromagnetic *Contributing Editor, International Journal of Powder Metallurgy, APMI International, 105 College Road East, Princeton, New Jersey 08501-6692, USA; E-mail:
[email protected].
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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INNOVATIONS DRIVE PM’S GROWTH PROSPECTS
Figure 1. Wheel motor designed for QMP SMC powders—schematic
materials with isotropic properties. A wheel motor designed with a stator made from an assembly of SMC segments is used for the production of small motorized carts, Figure 1. Copper powder suppliers are offering new products as well. ACuPowder International, LLC, Union, New Jersey, supplies a high-strength, high-hardness heat-treatable bronze alloy for gears, reports Edul Daver, president. Metal injection molding (MIM) grade powders for copper
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parts are growing in usage because of the higher cost of machining copper bar stock. Epson Atmix Corporation in Japan has introduced stainless steel and high-alloy steel granular metal powders based on its ultrafine powder water -atomization technology, reports R yo Numasawa, sales representative. Powder with an average particle size of 5 to 10 µm is granulated to an apparent density similar to that of 150 µm (100 mesh) powder, making it possible to pressand-sinter ultrafine powder for conventional PM parts. The powder offers superior sintered densities and improved properties, the company claims. The technology can also be used to make high-hardness-alloy grade powders. Epson says the new technology will provide materials for the press-and-sinter industry that were previously limited to MIM processing. EQUIPMENT INNOVATIONS Compacting press makers have been developing new technology in response to the demand for changes to existing products or changes in the marketplace, which have led to new press
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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INNOVATIONS DRIVE PM’S GROWTH PROSPECTS
designs, says Robert Unkel, manager of PM marketing, Cincinnati Incorporated, Cincinnati, Ohio. He sees a trend of returning to cooperative development among press builders, powder suppliers, and tool makers, as a way of reducing costs. He also sees a movement away from the implementation of new technology toward optimizing existing technology. Examples of recently developed technology that can be used to expand the market include: presses with up to 11 levels, which will help reduce secondary operations and enable more parts to be net shaped; higher -tonnage presses up to 2,450 mt (2,700 st) which will allow larger parts; computer-controlled servo presses; hybrid servo-press systems; and new warm compaction heating and delivery systems. Dorst America, Inc., Bethlehem, Pennsylvania, CEO Greg Wallis reports on press developments such as in-line measurement of the height and contour of parts by laser as well as laser inscription for part identification. In addition, he sees automated die-set changes, side compaction of multi-level parts, and quick-tool-change systems. Arburg GmbH & Co. KG, Lossburg, Germany, has introduced an electric injection machine for metals and ceramics that offers lower noise, improved productivity, shorter start-up time, and increased precision, Figure 2, reports Uwe Haupt, overseas sales/PIM sales. The company will also introduce a new 15 mm screw-size electric injection machine for micromolding applications. Future trends include two-component molding— molding two materials with slightly different shrinkage rates in a two-component application. Other trends are parts weighing >0.5 kg and microparts for medical applications. In Japan, hot isostatic pressing (HIP) is a widely accepted process to make pore-free and nongas-emitting materials, reports Tomomitsu Nakai, isostatic press section, heavy machinery department, Kobe Steel, Ltd. The materials are used for vacuum chucks and sputtering targets. The market for sputtering targets made from tungsten and ceramic materials is increasing annually. HIP units operate at a temperature higher than 1,600°C (2,912°F). Cold isostatic pressing (CIP) is used to form ceramic rod or pipe shapes. Betaalumina tubes for batteries are made this way. In the future HIP and CIP processing will be integrated or combined with other processes such as physical vapor deposition (PVD), chemical vapor deposition (CVD), and ink-jet printing. Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
Figure 2. Arburg electric two-shot 110 mt MIM machine
Increasing productivity by upgrading existing equipment is an important step to enhance growth, proposes Harb Nayar, president of TAT Technologies, Inc., Summit, New Jersey. His suggestion includes the simultaneous training and motivation of employees and implementing the best possible operating practices. He believes that a 30% jump in productivity is possible by using current knowledge and technologies to upgrade existing equipment. SELEE Corporation, Hendersonville, North Carolina, has developed a 3.2 mm thick zirconiatoughened alumina microporous setter plate for the powder injection molding markets (MIM and PIM), reports Wendi P. Williams, sales representative. Ultra Infiltrant, Carmel, Indiana, has received a patent on its wrought material-infiltration technology, covering alloy composition, infiltrationprocessing conditions, and the shape or form of the material available in wire, wafer, disk, or washer configurations. The material has been tested on PM automotive parts such as valve-seat inserts, main bearing caps (Figure 3), actuator
Figure 3. Ultra Infiltrant technology used in a main bearing cap
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INNOVATIONS DRIVE PM’S GROWTH PROSPECTS
gears, and planetary gear carriers and is expected to be used in commercial production. PM PARTS MAKERS ADVANCE PROPERTIES Allread Products Company LLC, Terryville, Connecticut, is experiencing growth in PM applications requiring secondary machining, reports William O. Allread, owner. Because of this the company has substantially increased its CNCmachining capability. Capstan Atlantic, Wrentham, Massachusetts, has expanded surface densification from singlelevel parts to complex multilevel gears and sprockets, reports Richard H. Slattery, vice president of engineering. Demand for crowned helical gears with improved load distribution on the face width of the gears is increasing, Figure 4. Gino Olivares S.r.l., Italy, is producing highprecision PM structural parts from iron, steel, stainless steel, brass, and specialty alloys, Figure 5. The company has compacting and sizing presses up to 350 mt. Hitachi Powdered Metals Co., Ltd., in Japan, has produced the following products, according to
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Figure 4. Surface densified helical gears
Figure 5. High-precision parts
Hiroshi Fujinami, president: a high-strength PF aluminum alloy; low-friction bearings; highstrength/high-machinability materials for automo-
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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tive applications; and magnetic powder and cores with high magnetic properties for diesel engines. NetShape Technologies, Inc., Campbellsburg, Indiana, is advancing its proprietary densification process, reports Ron Arble, director of business development. The company has achieved singlepress and single-sintered densities up to 7.5 g/cm3 as well as 7.65 g/cm3 with repressing. It is expanding its conventional compacting technology to make part geometries with up to nine separate levels via net-shape compaction. Anticipating future growth, NetShape has opened a new Lean Manufacturing PM parts plant in Suzhou, China. MIM AND OTHER TECHNOLOGY TRENDS Parmatech Corp., Petaluma, California, expects its MIM business to grow by 10% to 20%, reports Brian McBride, general manager. He notes that markets such as automotive, aerospace, and military are more open to MIM parts as a way of reducing component costs. HJE Company, Inc., Queensbury, New York, sees growth in precious metal MIM applications in dental and jewelry products, says Joe Strauss, president. Complex and abrasion-resistant hardmetal parts made by powder injection molding are being developed by Materials Processing, Inc. (MPI), Fort Worth, Texas, reports Animesh Bose, president. Current markets include consumer goods, aerospace, oil and gas, and defense. Parts with 0.762 mm (0.03 in.) dia. holes are being made as well as larger parts, ~254 mm (10 in.). Injection molding has been successful in making hardmetal twist blades (Figure 6) with a uniform helical twist. MPI is producing tubes with an inner rifling pattern with a uniform twist, orifices with a cone shape that transition into a uniform diameter, and hourglass-shaped inside diameters. Bose sees new attention aimed at grain-size refinement of powders, especially for refractory materials, to obtain ultrafine or nanoscale grain sizes. He cites chemical precursors to achieve ultrafine and nanoscale powder, and high-energy milling. He says high-energy milling can produce equilibrium and non-equilibrium phases of solidsolution alloys, intermetallic compounds, amorphous materials, and microcrystalline and
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
Figure 6. Hardmetal helical twist blade
nanocrystalline materials. He cites a silver–tin oxide composite made by the process in which the final structure has nanoscale SnO2 particles dispersed in a silver matrix, using a tin–silver alloy and silver oxide as the starting material. Carpenter Powder Products, Bridgeville, Pennsylvania, continues to invest in new technology, reports Louis W. Lherbier, director of business development. The company has improved melting procedures to give guaranteed levels of powder cleanliness and has installed new melting capacity. Other trends include a rapidly increasing demand from the energy market for as-HIPed intricate near-net shapes made from stainless steels and nickel-base alloys. There is also increased demand for cobalt-base high-alloy casting powder that improves wear and corrosion resistance in saltwater applications. Future trends include increased demand for PM nearnet-shape monolithic and composite products, laser technology to make free-form near -netshape specialty alloy powders, and the use of specialty alloy powders to make intricate net-shape parts by the ink-jet process. Tungsten Powder Technology (TPT), Israel, has introduced a new grade of copper-coated tungsten powder, reports Dov Chaiat, president. The material has a copper content range of 5 to 25 w/o. The grade eliminates tungsten segregation, TPT says, a typical problem in tungsten–copper blends. In another development the company is consolidating nano and ceramic powders by highpressure technology to reach pressed densities of 90%. Final density is achieved by short low-temperature sintering cycles to retain the nanograin structure. ijpm
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Exhibitor Showcase Experts from leading PM and particulate materials companies will answer questions about the latest trends in powders, production equipment, process technologies, testing, and QC equipment and products. The exhibition features process equipment and provides a valuable opportunity to meet with current or new suppliers. Receive immediate help with production and materials questions. Arrange appointments now with the companies you want to visit and arrive with your list of technical issues for one-on-one discussions. Take advantage of this valuable opportunity to gain new information from major suppliers and network with industry technical leaders.
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Listing as of April 18, 2008 ABBOTT FURNACE COMPANY St. Marys, PA Abbott specializes in continuous furnaces for sintering, steam treating, quenching, annealing, tempering, and brazing. Silicon Carbide muffles, a Quality Delube Processor, and VariCool are all popular options. Pusher furnaces and ceramic belt models are suitable for higher temperature applications. Spare parts, fabrications, repairs, and calibrations are offered. ISO/IEC 17025 Accredited.
AIR PRODUCTS AND CHEMICALS, INC. Allentown, PA As a worldwide leading industrial gas supplier, Air Products brings over 50 years of experience in gas supply and safety to help improve your operations' performance. We offer a full line of high purity gases - oxygen, nitrogen, hydrogen, argon, helium and gas blends-through liquid, bulk and microbulk gas delivery solutions. We also provide a variety of technical services and gas-based technologies to the powder metal industry.
ABTEX CORPORATION Dresden, NY Abtex Corporation manufactures a comprehensive line of fiber abrasive brushes and application-specific deburring systems that are custom designed to provide superior part deburring and surface treatment solutions for the continually evolving field of metal forming. Abtex planetary head flowthrough systems, and rotary indexing cells for more complex geometries, are ideal for powder metal parts.
ALCOA HOWMET Whitehall, MI Alcoa Howmet Hot Isostatic Pressing (HIP), Whitehall, MI, leads North American HIP production and teams with Alcoa Howmet Research Center in developing advanced techniques. Alcoa Howmet produces powder-metal near-net shapes and cladded composites, manufactures zirconia nozzles for powder production, has two class 100,000 clean rooms, and is ISO9002, AS9100 and Nadcap certified.
ACUPOWDER INTERNATIONAL, LLC. Union, NJ & Greenback TN ACuPowder, with plants in NJ & TN, is a major U.S. producer of metal powders. Products include: Antimony, Bismuth, Brass, Bronze, Bronze Premixes, Chromium, Copper, Copper Alloys, Copper Oxide, Copper Premixes, Diluted Bronze Premixes, Graphite, High Strength Bronze, Cu Infiltrant, Manganese, MnS+, Nickel, Phos Copper, Silicon, Silver, Tin, Tin Alloys and PM Lubricants. New products include powders for MIM, Thermal Management, "Green" Bullets, Lead Free Solders, Plastic Fillers, Cold Casting and most recently ULTRA INFILTRANT the wrought/wire infiltration solution.
AMERICAN CHEMET CORPORATION East Helena, MT & Deerfield, IL American Chemet, est. in 1946, manufactures copper powders, dispersion strengthened Cu, and copper and zinc oxides. Chemet’s oxide reduction process allows a high degree of control over particle size and shape in powders ranging from molding grade (150 mesh) to 12 micron median size.
ADVANCED VACUUM SYSTEMS (AVS, INC.) Ayer, MA Advanced Vacuum Systems, Inc., manufactures original, cost effective standard and custom vacuum and/or pressure furnaces for a wide range of materials processing. Systems range from lab to production scale with temperatures to 2500°C and pressures from 1x10-6 torr to 2500 psi. AVS also markets, manufactures and services the AVSHetherington furnaces.
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
AMETEK, INC. Eighty Four, PA Ametek and Reading Alloys produce specialty powders primarily for aerospace, automotive, electronic, hardware and medical industries. Products include Ultra 300 and 400 series stainless powders for PM, MIM, and filter markets, nickel base thermal spray powders and specialty alloys such as titanium CP and Ti 6/4 powders. Ametek/ Reading Alloys is a world leader in research, development and manufacture of high-grade aerospace master alloys, specialty metals, and coatings materials. APMI INTERNATIONAL Princeton, NJ APMI International is the professional society for individuals involved in powder metallurgy and particulate materials. Members include metallurgists, engineers, teachers,
students and business people. Some of the many benefits include: International Journal of Powder Metallurgy, Who's Who in PM membership directory, full access to PM NEWSBYTES and monthly PM Industry News Online. Stop by our booth and learn how APMI can be your professional resource. APPLIED SEPARATIONS, INC. Allentown, PA Debinding without solvents, without acids, without heat. Applied Separations uses supercritical fluids to debind both metal and ceramic parts. The company's technology also cuts the debinding time to minutes. Applied Separations offers a variety of production scale systems to process various part sizes. They are showing a laboratory scale system at the booth to demonstrate the use of supercritical fluid technology to debind parts. ARBURG GMBH + CO KG Lossburg, Germany & Newington, CT Joining PowderMet 2008 in Washington D.C., ARBURG offers intensive individual consulting on site when it comes to the PIM sector. The ARBURG machines for processing metal and ceramic powders using the PIM process are based on the current ALLROUNDER machine series. In Washington D.C., the ARBURG PIM specialists look forward to seeing you at booth 430. ASBURY-SOUTHWESTERN GRAPHITE Asbury, NJ For over 100 years the worldwide leader in graphites and carbons for the Powder Metal industry. Our complete line of natural and synthetic graphites for conventional PM applications, specialty materials for forging, bearing, and hard metal applications will be presented. Asbury also supplies a complete line of graphite sintering trays and graphite lubricants to the industry. Metal sulphides and metal alloy powders are also available from Asbury. AUTOMATED CELLS & EQUIPMENT Painted Post, NY Quality through automation and technology will be the focus of ACE in Booth #324. Live demonstrations will include a carbide insert Press Takeout and Traying System with automatic tray exchange; Tool Changing and Punch/Die Cleaning featuring
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Exhibitors a FANUC LRMate robot and iR Vision errorproof part detection. Engineers will be on hand to discuss specific requirements. AVURE TECHNOLOGIES, INC. Columbus, OH Avure Technologies, Inc. is the world’s largest manufacturer of hot and cold isostatic presses. Designs range from compact laboratory models to high-volume production presses with work zone diameters exceeding 7 feet. Avure has its headquarters in Kent, Washington, with production and sales operations in Vasteras, Sweden and Columbus, Ohio. BASF CORPORATION Evans City, PA BASF Catamold® is a ready-to-mold feedstock for MIM and CIM. Our material portfolio includes various low alloy steels, stainless steels, tool steel, soft magnetic alloys, super alloys, oxide ceramics, and custom grades to fit your unique needs. BASF also manufactures and markets the most diversified range of Carbonyl Iron Powders (CIP) available. BASF carbonyl iron powders are the largest volume metal powders in the MIM industry. Contact BASF for more information at 724-538-1363, via email at
[email protected] or on the web at www.basf.com/catamold and www.basf.com/cip. BATTENFELD OF AMERICA, INC. South Elgin, IL Welcome to Wittmann-Battenfeld, a world leader in injection molding of powdered metal. Please visit booth #236 and let us show you how this well-developed technology can provide growth potential and diversify your customer base with a small investment. Wittmann-Battenfeld’s proven solutions can make this a winner for you. BODYCOTE-HIP Andover, MA Bodycote - HIP Powder Metal (PM) technology has the capability to provide a unique combination of properties for demanding applications. Unlike traditional press and sinter PM technology the HIP process is without die friction forces that limit product size and density. We routinely make 100% dense parts as large as 25,000lbs in weight
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BRONSON & BRATTON, INC. Burr Ridge, IL Bronson & Bratton, Inc. has been in the Tool & Die business since 1948, and has been building PM Tooling since 1970. We have the Design (CAD), Manufacturing (CAM), and the experience to design and build the Tooling/Adapters required to fit your existing Compacting/Sizing Presses. We are ISO 9001:2000 certified. C.I. HAYES INC. A SUBSIDIARY OF GASBARRE PRODUCTS, INC. Cranston, RI Manufacturers of custom-designed sintering and heat treating furnaces with temperatures to 3000º F. Hayes' atmosphere furnace designs include, belt, pusher, walking beam. Vacuum Furnaces in batch or continuous and feature isolated heating and quenching chambers. Continuous vacuum carburizing. Endothermic, exothermic, and DA Generators. Full line of replacement parts. CARPENTER POWDER PRODUCTS INC. Bridgeville, PA Provides prealloyed powders that are tailored to meet customer requirements for thermal surfacing processes, metal injection molding, near net shape hot consolidation technologies, and mill form products (billet, bar, wire, plate, sheet, and strip). Our manufacturing versatility and technical knowledge enable us to provide you with consistent high quality products. CENTER FOR POWDER METALLURGY TECHNOLOGY (CPMT) Princeton, NJ The Center for Powder Metallurgy Technology (CPMT) is a not-for-profit foundation established by members from the PM community. CPMT funds cooperative technology programs focusing on R&D that bring together the corporate, academic, and research organizations to advance PM technology. Center members benefit from periodic research reports and guide the direction of research activities. Other activities include scholarships and grants provided to industry students. CENTORR/VACUUM INDUSTRIES, INC. Nashua, NH High performance Metal Injection Molding
Furnaces for alloy steels,stainless steel, tool steel, hardmetals and ceramics. Laboratory toproduction size. Temperatures to 2300ºC in vacuum, inert, or Hydrogen gas from 10750 torr. Graphite or refractory metal hot zones with proprietary Sweepgas™ binder removal systems for injection molded parts. CINCINNATI INCORPORATED Cincinnati, OH CINCINNATI INCORPORATED manufactures PM Compacting and Restrike Presses. All presses are backed by extensive support services including a dedicated ReManufacturing Facility for Reconditioning and Up-grading existing equipment to ensure maximum performance and productivity. Video and Photographs will be shown highlighting various products and services available. CM FURNACES, INC. Bloomfield, NJ Fully automated high temperature continuous pusher furnaces for both traditional powder metal and metal injection molding with inline debinding. These furnaces operate in a hydrogen/nitrogen atmosphere up to 3100° F with extremely low dew points. Also being displayed will be our line of high temperature hydrogen batch furnaces. COMPASS WIRE CLOTH CORP. Westville, NJ Compass Wire Cloth, an ISO-certified fabricator of wire cloth, produces fine mesh hooked, bonded, pre-tension to fit all OEMs, and aggregate screens and related wear parts. We can also fabricate custom specialty wire products to your requirements, including Trommel screens, metal edging, seaming, spot welding and pressure vessel screens. CREMER GMBH Düren, Germany CREMER Thermoprozessanlagen-GmbH is one of the world’s leading furnace suppliers with more than 40 years experience and world-wide references, especially for sintering furnaces in the field of PM up to 2.000°C with protective gas atmospheres and accessory equipment. Supported by our R&D departments for innovative custommade developments for PM and MIM. Professional representatives and service offices all over the world.
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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DISTEK N.A. LLC Brookline, MA DiSTeK N.A - ArmorGalv™ - Revolutionary, environment-friendly, corrosion protection for PM parts. The Thermo-Diffusion Galvanizing process will greatly expand the range of parts produced by PM technology. The ArmorGalv™ process results in a surface which does not require pre-treatment (steam, resin impregnation) and is: Hard, abrasion resistant, non-sparking, heat resistant and an excellent substrate for paint and rubber/plastic molding. DORST AMERICA, INC. Bethlehem, PA Continuous innovation, leading technology and outstanding customer service have made Dorst the market leader for CNC hydraulic presses in the PM and related industries. Our all encompassing approach, ranging from products to technological support and after sales service, enables customers to optimize the most demanding jobs and perform with exceptional capability and productivity.
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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ECKA GRANULES OF AMERICA LP Louisville, KY ECKA Granules is the leading manufacturer of non-ferrous metal powders. The product range includes Aluminium, Magnesium, Copper, Calcium, Tin, Lead, Zinc, Silicon and their alloys as well as Ready-to-press premixes. Production techniques include milling and grinding, electro-deposition, air, water and gas atomization, granulation and melting for recycling. ECM USA, INC. Kenosha, WI ECM USA, Inc. is the World Leader in Low Pressure Vacuum Carburizing and High Pressure Gas Quenching furnaces with over 600 cells (100+ cells in the USA) and 120 systems installed worldwide. ECM provides solutions for LPC, Neutral Hardening and Low Pressure Carbonitriding. Information about greater fatigue strength and decreased distortion for your heat treated parts is available. ECM systems have added heat treating, flexibility, safety, reliability and cost savings to our customers. Visit ECM USA booth #123.
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ELINO INDUSTRIE OFENBAU Düren, Germany Almost 60 years ago Elino built its first continuous sintering furnaces. Since then we have evolved into a world leader in engineering and manufacturing PM heat-treatment equipment, such as: Mo, W and WC powder, production plants, High temperature sintering equipment, Continuos MIM debindering and sintering furnaces ELMCO ENGINEERING INC. Indianapolis, IN ELMCO Engineering Inc. is a leading manufacturer of new and rebuilt PM equipment of all makes and sizes. We service all makes of presses, and have an extensive parts inventory. We are North American Representatives for Yoshizuka presses. ELMCO also offers custom engineering for special applications. Visit us in booth #513. ELMET TECHNOLOGIES, INC. USA Lewiston, ME Elmet Technologies is a fully vertically integrated ISO9000 Advanced Enabling Materials company. We produce both mill
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Exhibitors and custom machined molybdenum and tungsten refractory metal products. Elmet focuses on new and emerging technologies. We are experts in providing “total-cost of ownership” customer solutions coupled with industry leading personalized sales and service. ELNIK SYSTEMS (Division of PVA MIMtech, LLC.) Cedar Grove, NJ Elnik will introduce a new furnace called "PLASMIM" incorporating a plasma source providing clean debinding and reduced processing time. The “ONE SOURCE MIM” equipment is also featured. Let DSH Technologies, our affiliate, prove the feasibility of the process parameters for your MIM parts before you invest in expensive capital equipment. ENGINEERED CERAMICS A Division of SELEE CORPORATION Gilberts, IL Engineered Ceramics specializes in alumina, fused silica, mullite and silicon carbide shapes for molten metal handling, kiln furniture and other high temperature applications. Via product development initiatives, we now offer Micromass® and ceramic
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foam low mass kiln furniture, which provide engineered solutions when chemical inertness and low mass insulating properties are beneficial. ISO certified since 1995. ENGINEERED PRESSURE SYSTEMS Haverhill, MA EPSI designs high-pressure systems for manufacturing, testing, research and specialized high-pressure applications. EPSI will be the sole strategic partner of FCT Systeme within the USA and Canada. FCT is world-wide leading producer of high temperature/ high-pressure gas pressure sintering furnaces and spark plasma sintering equipment. ERAMET MARIETTA INC. Marietta, OH Eramet Marietta, Inc. is a leading producer of high-purity chromium metal and chromium carbide powders. Produced to meet exacting customer requirements, these powders are used in powder-metallurgy parts, consumable electrodes for welding, hard-facing applications, thermal-sprayed coatings, plasma-arc welding, electrical-resistance alloys, sputtering targets, and infiltrants.
ERASTEEL KLOSTER AB DIVISION OF ERAMET Söderfors, Sweden Erasteel: Your flexible powder source with atomization units based in Sweden and 40 years of experience, Erasteel is the world leading producer of high quality gas-atomized metal powders for tooling and components. Alloy types include high speed steels, tool steels, stainless steels and other alloys. Contact us at
[email protected] EROWA TECHNOLOGY, INC. Arlington Heights, IL “Pulverizing Set Up Times” - EROWA Technology (Arlington Heights, IL) is the world leader in palletization and automation solutions for the manufacturing industry. EROWA’S PM Tooling System palletizes the punches as well as the die/mold; enabling press resetting in less than 3 minutes. The 0.002mm repeatability eliminates punch damage during press set-up. See us at the PM2008 World Congress booth #600! EUROPEAN POWDER METALLURGY ASSOCIATION Shrewsbury, England The European Powdered Metallurgy
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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Association (EPMA) serves all types of powder metallurgy companies/organisations from component manufacturers, metal powder producers, equipment makers through to end-users, universities and individuals who have an interest in PM. Find out about EPMA Membership and how it can benefit your company at www.epma.com EUROTUNGSTENE - MEMBER OF THE ERAMET GROUP Grenoble, France Eurotungstene supplies high purity metal and poly-metallic powders to answer customers needs. Experience and an ongoing process of innovation have established eurotungstene as a technological leader and a specialist in powder metallurgy. Markets : Diamond Tools (pre-alloyed NEXT® and Keen®, Cobalt), Cemented Carbides, MIM, High Density Materials. FETTE COMPACTING Rockaway, NJ FETTE GmbH, the world leader in tablet press technology, also offers a range of high-precision hydraulic presses for the manufacturing of carbide cutting inserts. These systems can be provided complete with Pick-and-Place robots for off-loading and the touch-screen control system includes advanced data-acquisition capabilities. FLUIDTHERM TECHNOLOGY Chennai, India Fluidtherm manufactures belt & pusher furnaces for the PM, MIM & Hardmetal industry for debindering, sintering, powder annealing and carburisation as well as furnaces for steam treatment & heat treatment (including low pressure carburising with pressure gas quench). Ruggedly constructed by a skilled & experienced workforce, Fluidtherm furnaces are characterised by very high uptime & low energy consumption. FRAUNHOFER IFAM Bremen, Germany The Shaping and Functional Materials Division of Fraunhofer IFAM offers contract research and development services in the areas: Powder Technology and Powder Metallurgy - Rapid Manufacturing Nanopowders - Metal Injection Moulding Laser Sintering - Warm Flow Compaction Micro engineering - Composite Materials Sintering Technologies - Cellular Materials. Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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GASBARRE PRESS DIVISION GASBARRE PRODUCTS, INC. DuBois, PA Designers and manufacturers of single-level and multi-level Mechanical and CNC Hydraulic Presses - 5 to 1200 Tons for compacting and sizing of structural PM parts. Removable die set presses are available. Hydropulsor High Velocity Compacting Presses to 2000 Tons. TOPS Powder Heating Systems, Die Wall Lubrication Units, Fluidized Filler Shoes, Parts Automation, and Powder Handling Systems. Extensive rebuild services. GRAPHIT KROPFMÜHL AG Hauzenberg, Germany Graphit Kropfmühl AG has a 125 year tradition of competence in raw materials and decades-long experience in graphite refining. With their own raw material resources, global commitment and permanent research work, Graphit Kropfmühl AG continuously open up new fields of application and develop efficient tailor-made solutions together with their customers. GRIPM ADVANCED MATERIALS CO., LTD Beijing, China GRIPM, largest electrolytic copper powder producer in China with annual capacity 8000 MT. Specializing in powders of: Bronze, brass, P-bronze, Ti-bronze and CuAl; Atomized tin, diffusion CuSn alloy; ferroalloy (MoFe, PFe, TiFe, CrFe); cobalt, cobalt alloy etc. applied in PM parts, diamond tools, carbon brushes, friction material and electronic chemical industry etc. Powders and wires used in thermal spray applications supplied also. H.C. STARCK, INC. Newton, MA H.C. Starck ranks among the world’s leading manufacturers of refractory metals such as tungsten, molybdenum, tantalum, niobium, and rhenium; electronic chemicals and ceramic powders. H.C. Starck continues to strive to further strengthen its ability to bring material solutions to the market. Please visit our booth for more details. H.W.F. INC. Cincinnati, OH H.W.F. INC. will be showing a Tsukimura press model PT-40 multi-motion die set.
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H2GEN INNOVATIONS, INC. Alexandria, VA H2Gen manufactures low-cost, small-scale hydrogen generators for industrial applications and for the emerging fuel cell vehicle and distributed power generation markets. Our proprietary packaged hydrogen generator modules (HGM) produce pure hydrogen from natural gas. The system operates automatically and is fitted with a remote monitoring system. Cost, utility consumption, footprint and start-up time of the HGM have been greatly reduced compared to standard industrial practice through our patented break-through design and careful integration of the HGM’s individual components. HENKEL TECHNOLOGIES Rocky Hill, CT Henkel, a recognized and valued supplier of engineered adhesives and sealants, has developed the Loctite® Impregnation Systems (LIS) of Loctite® high performance impregnation technology for sealing powder metal components. Henkel maintains an Impregnation Process Engineering Laboratory in Madison Heights, MI to evaluate and test customer parts and optimize the choice of impregnation resin and equipment. HERNON MANUFACTURING, INC. Sanford, FL Hernon Manufacturing, Inc., is ISO9001:2000 Registered, manufacturing a complete line of Anaerobic and heat cure impregnation resins and equipments for past 30 years. Hernon’s HPS 990 and HPS 991 are QPL listed and meet MIL-STD-276, MIL-I-17563, MIL-I-13857, MIL-I-6869, and automotive approvals. Hernon also manufactures HPS 1200 flexible resins for electronic applications, high temperature sealants, spray on sealants and process verification marking. Please contact Hernon customer service for your impregnation resin needs. HK TECHNOLOGIES, A SUBSIDIARY OF CLEVELAND VIBRATOR CO. Salem, OH HK Technologies, an affiliate of The Cleveland Vibrator Co., will be exhibiting our full line of ultrasonic screening equipment. Models range from 8" diameter lab units to
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Exhibitors larger production models. The HK Ultrasonic conversion screener will be displayed. This unit equips any screener with the HK Ultrasonic Deblinding System. HOEGANAES CORPORATION Cinnaminson, NJ Hoeganaes Corporation, world leader in ferrous powder production, has been a driving force within the PM industry’s growth for over 50 years. It has seven manufacturing facilities in the United States and Europe to meet customers’ needs worldwide. The company continues to invest in programs that increase production capacity while improving metal powder manufacturing. It holds these certifications: ISO 14001, ISO/TS 16949, and QS 9000. HOLROYD EDGETEK Farmington, CT Holroyd Edgetek's line of Superabrasive Machines provide greatly reduced cycle times while reducing consumable costs by as much as 90% through the use of Superabrasives incorporating HEDG technology. Extremely effective in interrupted cuts and machining of otherwise difficult to machine materials found in the Powdered Metal, Aerospace and Medical industries. HYDROPULSOR AB Karlskoga, Sweden With cost-effective green densities as high as 97%, and re-strike densities as high as 7.7 g/cc, Hydropulsor AB is the leading manufacturer of high velocity compaction and high velocity restrike equipment. Also included in the product program is a new generation of Result hydraulic presses for the carbide industry. IMPCO, INC. East Providence, RI Impco Inc. is a manufacturer of anaerobic and thermoset impregnating resins for sealing porosity in powdered metal components. Our PoreSeal impregnation process has been refined to produce consistent impregnation quality to insure successful secondary operations such as plating. Impco also designs and manufactures complete impregnation process lines for all porosity applications. INCO SPECIAL PRODUCTS Mississauga, Ontario, Canada Inco Special Products is a dedicated busi-
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ness unit of Vale Inco Limited, the World's Leading Nickel Company. Refineries in North America and Europe produce carbonyl nickel powders of various sizes, shapes, and morphologies to the ISO9002 standard. Products supplied to the PM and MIM industries include: T123 PM, T110 D, T255, T287 and Novamet 4SP-10. INDUSTRIAL HEATING MAGAZINE Pittsburgh, PA The Metal Powder industry's only fully audited monthly trade journal for metal powder engineers, part designers, applications engineers, equipment manufacturers, powder producers, and suppliers." INTERNATIONAL SPECIALTY PRODUCTS, INC. Wayne, NJ ISP is the sole U.S. manufacturer of carbonyl iron products, with 65 years experience in R&D, production, QA and global distribution. Distinct characteristics of the MICROPOWDER Iron products include spherical shape, fine micron size, uniform distribution and high purity. ISP markets more than 25 MICROPOWDER Iron grades for MIM, classical PM, microwave absorbers, electronics, pharmaceutical and other applications. JAPAN POWDER METALLURGY ASSOCIATION Tokyo, Japan Japan Powder Metallurgy Association (JPMA) is a trade organization consisted of manufacturers of PM products, raw powder materials, related equipment, and business enterprises. We are contributing to the promotion of the world PM industries cooperating with MPIF, EPMA, and Asian PM related Associations. Following PM 2010 Firenze to be carried by EPMA, PM 2012 Yokohama will be held by JPMA jointly with JSPM, at Yokohama, Japan in October, 2012. KITTYHAWK PRODUCTS Garden Grove, CA Kittyhawk Products - qualified experts in the field of HOT Isostatic Processing - HIP is a process of unique benefit in solving complex design problems while increasing the strength of properties. Through our sister company, Synertech PM, Inc., we offer unmatched net shape capabilities with powder metal parts design and manufacture. Kittyhawk Products holds ISO9001 and AS9100 certification.
KOBELCO METAL POWDER OF AMERICA, INC. Seymour, IN Kobelco Metal Powder of America, Inc. a subsidiary of Kobe Steel, Ltd. is a major U.S. producer of high quality, water-atomized ferrous powders, pre-alloy powders and premixes for use in the PM and related industries. An ISO/TS-16949 certified company. Kobelco offers complete production and laboratory facilities for testing and development activities. LASCO ENGINEERING SERVICES, L.L.C. Detroit, MI LASCO Engineering Services is the US arm of LASCO Umformtechnik in Coburg, Germany. LASCO is a 135 year old company producing metal forming machines for export around the world. LASCO Engineering Services will be presenting their new line of powder metal compacting presses along with coining and powder metal forging equipment. LOCTITE See Henkel Technologies LONZA INC. Allendale, NJ Lonza is the world’s leading producer of ethylene bis-stearamide lubricants to the Powdered Metal Industry. Lonza’s Acrawax C® Atomized and Powdered Grades are 100% organic clean burning lubricants, and are long time standards for Powdered Metal Applications. They provide excellent flow, green strength, and sintering properties. With its manufacturing base in Central Pennsylvania, Lonza is known for its outstanding service to the Powdered Metal Industry. LUOYANG ACHEMETAL CO. LTD, CHINA U.S. Contact: Achemetal, Inc. Luoyang, Henan, China & Wayne, NJ Luoyang Achemetal Co. Ltd manufactures Molybdenum, TZM, Tungsten, Tantalum and Niobium in form of Sheet, Plate, Foil, Bar, Rod, Tube as well as finished machining part per ASTM, AMS, and Mil Spec etc.
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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Exhibitors MAGNAFLUX - QUASAR PRODUCTS Albuquerque, NM The new Quasar 4000 Nondestructive Test System is a computer-based production test system for robust and inexpensive structural part sorting. It reliably classifies defective powder metal parts containing cracks, chips, voids, and unacceptable deviation in material, hardness, porosity, density, and dimension while ignoring normal production variations. Manual and automated handling available.
METAL POWDER INDUSTRIES FEDERATION Princeton, NJ Stop by to learn about membership benefits, programs, association committee activities, and any other topic of interest to you. If you have comments or ideas regarding the Federation and its services, let us know when visiting us at our booth. If your company is not a member of MPIF, you can discuss membership opportunities and benefits with someone from headquarters staff.
MAGNESIUM ELEKTRON POWDERS Manchester, NJ Magnesium Elektron Powders is a producer of magnesium powders and specialty niche alloy powders. It has three facilities in North America, producing various types of powders. The company manufactures a wide range of atomized and ground powders to military specification. The company also manufactures powders for steel desulphurization, chemical synthesis, welding applications, powder metallurgy, specialty pyrotechnics, and flameless ration-heater pads.
METAL POWDER REPORT Oxford, UK England Metal Powder Report has charted the expansion of the powder metallurgy business over the past 50 years. It is the premier international and independent magazine for the powder metallurgy industry reporting on technical trends in the manufacture, research and use of metal powders. Sample copies will be available at the booth or logo on to http://www.metalpowder.net/sample.asp
MANITOBA CORPORATION Lancaster, NY Manitoba Corporation is currently celebrating our 92nd anniversary. Our main focus is the sale of recycled and primary non- ferrous metals. We currently supply copper, zinc, silicon, & iron to the primary aluminum and powder metal industries. We also provide packaging services for the powder metal industries. We can package bulk powder or metal flake into many different containers such as bags, boxes, pails, cans and drums. MAX-TEK® LLC Milldale, CT MAX-TEK®, LLC designs and sells Superabrasive Machining Systems specifically suited for a variety of customer applications; automotive, aerospace, power generation, pump, compressor and medical industries. We have developed several innovative cost competitive machine designs that are a culmination of over 25 years experience in the design and construction of Superabrasive Machinery. The MAX-TEK®, LLC machines are built to the highest industry standards with many new features not found on competitive machines in the marketplace today.
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METAL PROCESSING SYSTEMS INC. Elk Grove Village, IL Metal Processing Systems, Inc. is an importer of state-of-the-art metal processing equipment for North America. One of which is Spark Plasma Sintering. SPS is a breakthrough powdered metal rapid sintering technology capable of achieving single press full density or high porosity samples with little particulate damage and no need for binders. METEC POWDER METAL AB Karlskoga, Sweden When it comes to cost-effective, high density PM components, Metec Powder Metal AB is setting new standards for the industry with its unique combination of HVC (high velocity compaction) and HVR (high velocity re-strike) equipment, state of the art sintering, and Metec’s patented process for agglomerating high alloy powder metals. MINOX/ELCAN, INC. Mamaroneck, NY Minox-Elcan specializes in advanced screening equipment used in the powdered metals industry. Minox tumbler screeners utilize several types of anti-blinding devices that yield high efficiency and throughput. Kroosher screeners have been very effective in powdered metals applications due to
the high energy transfer to the screen surface. Both technologies are available for testing and toll processing of up to 100,000 lb lots of materials. MOLDED FIBER GLASS TRAY CO. Linesville, PA Molded Fiber Glass Tray Company manufactures a wide range of sizes and styles of reinforced composite trays and boxes for the handling of both formed and sintered parts. Load carrying capability, stacking ability, and heat resistance are benefits for powder metallurgy manufacturers. Visit our website at www.mfgtray.com, or call 1-800458-6050. NANJING EAST PRECISION MACHINERY CO. LTD Nanjing, China EPM is a leading automatic mechanical dry powder compacting machine manufacturer in China, which has 70% market share in China and produces more than 300 pieces of machines in one year with 7 series and more than 20 types from tonnage 3 to 200. EPM is starting its international strategy and is believed to be able to satisfy the world customers. NETZSCH INSTRUMENTS INC. Huntersville, NC Thermal analysis & thermal properties instruments w. contract testing services available; Dilatometers for CTE and sintering optimization, Laser Flash Thermal Diffusivity & Thermal Conductivity, DSC, DTA, TGA, STA (TGA-DSC/DTA), coupling to FTIR & MS, DMA, TMA, Guarded Hot Plate, Heat Flow Meters, plus a fully equipped contract testing lab in Burlington, MA. NIRO INC. Columbia, MD Niro is a world leader in spray drying technology for production of hard metal powders and carbides. Spray drying is the preferred technology for production of ready-to-press powders and applied by most of the industry due to its ability to control particle formation and because it gives a free-flowing powder in one single operation. NORILSK NICKEL JSC MMC Moscow, Russia “Norilsk Nickel” is one of the world’s premier mining and metallurgical companies and Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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leading producer of Nickel, Cobalt and Platinum group metals with stable foreign trade in Europe, North & South America and Asia. Unique nickel powders of “Norilsk Nickel” can be used in PM, magnets, ferrites, special plating, ceramics and batteries production. NORTH AMERICAN HÖGANÄS, INC. Hollsopple, PA North American Höganäs, Inc. offers metal powder solutions that create new business and profitable growth for partners and customers. Metal powder range includes: Plain Iron, Prealloyed Steel, Diffusion Alloyed, Stainless Steel, Tool Steel, Gas Atomized and Electrolytic Iron. Premixed and bonded Starmix materials OSRAM SYLVANIA PRODUCTS, INC. Towanda, PA OSRAM SYLVANIA’S Global Tungsten and Powders Division, located in Towanda, Pennsylvania, and OSRAM BRUNTAL, located in Bruntal, Czech Republic, combine to create a world leader in the production of tungsten, tungsten carbide, molybdenum, cobalt, and tantalum powder products. OSRAM SYLVANIA features its SYLCARB™ tungsten carbide powders, POWDER PERFECT™ thermal spray powders, and high green strength tungsten powders for a number of applications and manufacturing processes including MIM. We are also a major producer of tungsten and molybdenum ingots, billets, plate, sheet and wire. We service the hard materials, energy, automotive, defense, electronics, medical, and aerospace markets OSTERWALDER AG Lyss, Switzerland OSTERWALDER AG, the leading powder press manufacturer, presents our newest developments in our Hydraulic Powder Presses CA-SP, CA-MP, CA-NC II, UPP as well as the Mechanical Hydraulic Powder Press KPP. These developments bring surpassing savings in set-up time and unrivaled benefits in the overall quality and productivity of your compacts. PHILIPS ADVANCED METAL SOLUTIONS Turnhout, Belgium Philips Advanced Metal Solutions is a specialist producer of tungsten and molybdenum components serving applications in various industries. Our broad technical Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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expertise in alloying, material engineering and shaping technologies enables us to deliver the refractory metal products you need in a reliable and cost-effective way. For more information, visit: www.philips.com/ams PLANSEE GROUP Reutte, Austria Three Divisions – one aim Excellence in Powder Metallurgy. Plansee Group is one of the world’s leading suppliers of powder metallurgical products and components based on high performance materials (molybdenum, tungsten, tantalum, niobium and their alloys) and ferrous powders. www.planseegroup.com. To support our customers as well as future technology, we have concentrated our material competencies into three independent divisions: Plansee High Performance Materials, Ceratizit Hardmetals & Tools and PMG PM-Products. POLYMER-CHEMIE GMBH Bad Sobernheim, Germany Polymer-Chemie was founded in 1973 and is a leading compounder with a production volume exceeding 150,000 tons of polymer compounds per year. Metal Powder Compounds is a division of Polymer-Chemie GmbH founded in 2005 specialised in the development and marketing of standard and custom-made feedstock for metal injection moulding under the product name polyMIM®. All common MIM metal alloys are available as standard feedstock compounds. The portfolio includes low alloy, stainless and super alloy feedstock. POMETON POWDER Venice, Italy Founded in 1940 and based in Venice, Italy, Pometon supplies its range of ferrous and non-ferrous powders to PM and other industrial clients in over 40 countries worldwide. We produce pure powders such as iron, copper (both electrolytic and atomised), bronze, brass, tin and zinc, and press-ready iron and bronze premixes. POWDER INJECTION MOLDING INTERNATIONAL Shrewsbury, England Powder Injection Moulding International is a quarterly magazine that offers in-depth industry coverage of the MIM, CIM and carbide injection moulding industries. Each issue features industry news, company
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reports, exclusive commissioned features and leading technical papers. The publisher, Inovar Communications, will also be presenting the latest “International Powder Metallurgy Directory” 2008-2009”. PRECISION COMPACTING TECHNOLOGIES, INC. Bentonville, AR Precision Compacting Technologies, Inc. offers a full range of new, used, and remanufactured mechanical and hydraulic powder compacting presses. We maintain the largest inventory of high precision compacting presses in the United States and are the North American distributor of ATLASpress. PRECISION EFORMING Cortland, NY Precision Eforming manufactures electroformed filtration material, for precision separation of materials. The highly adaptable material is available with openings in micron increments from 3 to 2,000. The material can be used with any existing separation system, both in the lab and production. Featured at our booth will be our new ultrasonic system. PTX-PENTRONIX, INC. A SUBSIDIARY OF GASBARRE PRODUCTS, INC. Lincoln Park, MI Designers and manufacturers of highspeed, mechanical compacting presses, 2 tons to 35 tons. Anvil and opposed-ram designs available. With speeds up to 300 pcs/min, and multiple cavity capabilities, extremely high production and high precision are achieved on PTX presses. PTXPentronix also manufactures automatic, high-speed parts handling and robotic parts -palletizing systems. Distributors for Simac Isostatic Dry Bag Presses. PYROTEK INC. Canastota, NY Pyrotek is a leading international company focused on improving customer performance in high-temperature material industries. We supply a wide range of products including; coatings, sintering furnace materials, precast refractories, graphite tubes and fixtures, and custom safety clothing. Our mission is to provide innovative solutions to customer needs utilizing our global resources.
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Exhibitors QMP Sorel-Tracy, Canada QMP, registered to ISO 9001, ISO 14001, and ISO/TS 16949, manufactures a full product line of iron and steel powders. ATOMET standard grades and prealloys, binder treated FLOMET™ mixes, diffusion bonded ATOMET DB powders, machinable (sulphur-free) grades, sinter-hardening grades, and soft magnetic composite materials are available to customers worldwide.
QUANTACHROME INSTRUMENTS Boynton Beach, FL Laboratory analyzers for porous materials and powders; tapped bulk density, true density, porosity, pore size, B.E.T surface area. Instruments include tap density testers, gas pycnometers, intrusion porosimeters, gas sorption analyzers and last but not least rotary rifflers for powder sample splitting. ISO 9001 registered manufacturer. Sales and support worldwide."
QUALA-DIE, INC. St. Marys, PA QUALA-DIE, INC., St Marys, PA, Powder Metal Tooling and Precision Machining for all industries. From design through manufacturing Quala-Die stands for Quality, Competitive Pricing, and Delivery. Visit us on the web at www.quala-die.com or call (814) 781-6280
READING ALLOYS, INC. See Ametek, Inc.
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ROBOWORKER AUTOMATION GMBH Weingarten, Germany The core business of ROBOWORKER comprises the development and production of loading and unloading systems as well as solutions for palletising tasks and quality control. With focus on the development of first class technologies for the automation of
presses and tooling machines, we have special knowledge in the carbide sector. The state-of-the-art systems of ROBOWORKER are “Made in Germany” and they are in use all over the world. RUSSELL FINEX, INC. Pineville, NC Russell vibratory screeners and separators improve particle size control and ensure that your products meet precise specification. The Compact screener is suitable for highcapacity check-screening and grading metal powders. The Vibrasonic deblinding system eliminates mesh blinding and increases screening efficiency, allowing metal powders to be accurately screened down to 20 microns RYER, INC. Temecula, CA Ryer, Inc. is a Manufacturer, Developer and Supplier of Custom and Standard
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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Feedstock’s for the Metal Injection Molding Industry. Ryer manufactures a variety of Standard Feedstocks in addition to our Custom formulated Feedstocks to match your current material shrink specifications. For more information visit us on the WEB at www.ryerinc.com. SANDVIK OSPREY LTD. (Powder Group) Neath, United Kingdom Specialist manufacturers of gas atomised powders with a size range from 1 - 250 microns. Their alloy range, already the largest in the world for MIM applications, also includes thermal spray, rapid prototyping, HIPping and brazing powders. Accredited to ISO 9001:2000 and ISO 14000, Osprey is a Sandvik Materials Technology Company. SCM METAL PRODUCTS, INC. A Gibraltar Industries Company Research Triangle Park, NC & Suzhou, China SCM Metal Products is a leading manufacturer of powdered metals and pastes with manufacturing facilities in the U.S. and China. Our metal powders include, copper, bronze, brass, infiltration, friction copper, copper oxide, tin and lead. SCM also produces a line of specialty paste products for infiltrating and sinterbrazing PM parts as well as for furnace brazing of steel components. SELEE CORPORATION Hendersonville, NC SELEE Corporation manufacturers Micromass® micro-porous and Tylar® open cell ceramic, custom-made, low mass, kiln furniture. Our low mass plates allow for fast heat up and cool down shortening your firing cycles, increasing productivity and reducing energy consumption as compared to traditional dense kiln furniture. We are an ISO9001 and ISO 14001 certified company. SELEE Corporation is located in North Carolina. Please come see us at booth # 520. We look forward to meeting you! SHANGHAI LEADING METAL TECHNOLOGY Shanghai, China ISO 9001:2000 certified manufacturer and supplier of finished component and semi-finished stock from Tungsten, W-Ni-Fe, WCu, Molybdenum, Titanium, Tantalum, Niobium, Zirconium. Various forms available. Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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Specialize in production of W-Ni-Fe, W-Cu and Mo-Cu thin sheet and part, X-ray rotating anode target for X-ray tube SHIVANSHU SINTERED PRODUCTS PVT LTD Haryana, India Shivanshu Sintered Products (SSPPL) is upcoming world class plant in India for a large range of sintered products. Our motto is to achieve the highest level of Customer satisfaction by providing the fastest best quality sintered products to them. We are capable of manufacturing the sintered parts like valve train parts (Valve seat, valve guide etc.), Transmission parts (Engaging gear, Synchro Key etc.) bush, pulley, oil pump rotors, water pump pulley , sleeve and other structural parts. We at SSPPL believe in building world class Infrastructure backed with experienced Manpower and strong Design & Development and Vendor support. SINTERITE FURNACE DIVISION - GASBARRE PRODUCTS, INC. St. Marys, PA Sinterite designs and manufactures continuous belt and batch furnaces for sintering, steam treating, annealing, brazing, and heat-treating applications. High-Temperature Pusher Furnaces (over 350 manufactured) in several designs for iron and stainless steel parts (to 3000˚ F). VersaCool in-line cooling systems for sinter-hardening; Accelerated De-lubrication Systems (ADS). Alloy or Ceramic muffles available. Replacement muffles, powder-handling equipment, and fabrication products. SINTEZ RUS MIM, LTD. Dzerzhinsk, Russia Sintez RusMIM is a leading Russian manufacturer of standard and custom-made carbonyl iron powders widely used in metal injection moulding, diamond tools and synthetic diamonds production, radiotechnology and electronics. For more information visit us on the web at www.sintez-rusmim.ru. SMART MATERIALS MLC EXTRUSION SYSTEMS Kochav Yair, Israel Extrusion Ltd from Israel developed and designed Super High Pressure (SHP) pressing and extrusion system with seals and vessels for pressures of up to 18000 bars. Smart Materials Israeli engineering compa-
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ny for PM technologies is developing processes to press metal and ceramic powders by SHP technology to reach 95% of the theoretical density. SMS MEER A COMPANY OF THE SMS GROUP Moenchengladbach, Germany & Pittsburgh, PA In addition to equipment for pipe and long product rolling mills, forging presses and the NF metal industries, we design and build hydraulic and mechanical powder presses of which we have already sold more than 1,800. For over 50 years, we have been the competent partner for the metal powder, ceramics and tungsten carbide industry. SOLAR ATMOSPHERES INC. Souderton, PA Solar Atmospheres, vacuum heat treating specialists, provides vacuum sintering, degassing, low temperature drying, high temperature purification, high temperature compound formation, carburizing, and nitriding for the powder metal industry. Capabilities include over 40 vacuum furnaces, from laboratory, for cycle development, up to 36 feet long for production services. AS9100:2004 SPHERIC TECHNOLOGIES, INC. Phoenix, AZ Spheric Technologies markets Spheric/Syno-Therm™ microwave sintering systems and technology for the powdered metals and advanced ceramic industries. Spheric Technologies holds the exclusive license from Penn State University for patents covering microwave technology to sinter powdered metal, certain other materials and industrial microwave furnace design. Spheric is the exclusive Western Hemisphere distributor of Syno-Therm hightemperature microwave systems. www.spherictechnologies.com SUPERIOR GRAPHITE CO. Chicago, IL Superior Graphite specializes in thermal purification, advanced sizing, blending and coating technologies, providing value added graphite and carbon-based solutions globally. Combining 90 years of experience and advanced technologies into every faucet of the organization, a wide range of markets are served such as; advanced ceramics, agriculture, battery/fuel cells, ceramic armor, carbon
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Exhibitors parts, ferrous/nonferrous metallurgy, friction management, hot metal forming, polymer/composites, powder metals, lubricants and performance drilling additives. North and South America contact:
[email protected] m or in Europe/Africa/Asia/Australia contact: CustomerServiceEU@Superior Graphite.com TECHNICAL PRECISION, INC. Hadley, PA Technical Precision Inc. is a tool manufacturing leader in the PM industry with services ranging from complete sets and hardware to expedited reworks and reface’s. Our modern facility hosts state-of-the-art equipment with an experienced workforce. Our team is dedicated to quality and appreciates the opportunity to service you and your tooling requirements. THE ALLOY ENGINEERING COMPANY Berea, OH The Alloy Engineering Co has been recognized for its expertise in the design and fabrication of products utilized in high temperature and corrosive environments since 1943. We
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have also acquired two major high-temperature fabricators - TEI/Rolock and Walmil - that has strengthened our engineering and fabricated-product offering to the powder metal industry. In addition to a variety of products including fabricated muffles and high temperature fans, Alloy Engineering offers extensive alloy-materials expertise, design know-how, and fabrication capabilities.
parts, on time, giving you and your customer confidence in the quality of your parts. NDT-RAM systems detect variances in nodularity, dimension, geometry, weight, voids, cracks, density, porosity, bonding, brazing, and machine process. A free parts test will determine if your part is a good candidate for NDT-RAM. Contact TMS at www.ndt-ram.com.
THE CENTER FOR INNOVATIVE SINTERED PRODUCTS (CISP) University Park, PA The Center for Innovative Sintered Products (CISP) is a powder processing development facility that is fully equipped for both fabrication and analysis of particulate materials. The facility offers powder characterization, thermal analysis, powder mixing, shape forming, and sintering. We do short term and long term development projects and testing services.
THE WIRE MESH BELT COMPANY Brampton, Ontario, Canada Manufacturing top quality mesh belting for use in high temperature furnaces for 40 years. Specializing in custom designed Double Balanced & Balanced Flat Spiral (BFS) belting used in sintering, brazing and annealing operations in temperatures to 2300°F. Our flexibility and service will eliminate costly downtime with delivery in days.
THE MODAL SHOP, INC. Cincinnati, OH The Modal Shop’s NDT-RAM systems are designed to help you deliver fully inspected
THERMAL TECHNIC Newburyport, MA Thermal Technic, Inc., builder of the Thermal Force muffle, specializes in designing and building the alloy muffle for sintering and annealing processes. Our muffle
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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designers and network of heat resistant alloy metallurgists combine to manufacture muffles that provide extreme service life. We welcome muffle problems and challenges anywhere in the world. Additionally, Thermal Technic proudly represents Wire Mesh Products in the Northeast and Western U.S. states. THERMAL TECHNOLOGY LLC Santa Rosa, CA Thermal Technology LLC is a high temperature equipment manufacturing company whose broad line of equipment includes: spark plasma sintering (SPS), crystal growing systems, arc furnaces, and high temperature vacuum and controlled atmosphere furnaces. This incredible product line with its associated engineering and applications skills make Thermal Technology LLC one of your best resources for thermal processing. THINK “SOLUTIONS!” TIMCAL GROUP Westlake, OH Timcal Graphite and Carbon, a member of Imerys a global leader in adding value to minerals, produces a full line of graphites designed specifically for the PM industry: including high performance primary synthetics and custom sized natural flakes using raw material sourced from our 100% owned North American mining operation. U.S. DEPARTMENT OF COMMERCE Washington, DC The U.S. Commercial Service — Your
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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Global Business Partner. With offices across the United States and in more than 75 countries, the U.S. Commercial Service of the U.S. Department of Commerce’s International Trade Administration supported nearly 12,000 U.S. business successes in 174 markets around the world. Through our unique mix of trade expertise, governmental influence and worldwide reach, we helped companies leverage U.S. trade agreements, target the best opportunities with our worldclass market research. To learn more, visit export.gov/cs or call us at 800.USA.TRADE. ULTRA INFILTRANT Carmel, IN The patented Ultra Infiltrant Wrought/Wire Copper Infiltration Technology has raised the bar. The surface erosion, adherent residue, high cost and hassle factor associated with pressed copper powder infiltrants are things of the past. UI delivers superior mechanical and metallurgical results that far exceed the MPIF Standard 35. UI also adds solid performance to your bottom line – Custom made preform parts manufactured to your exacting specifications are delivered ready for assembly with your green parts – All the non-value added process is removed. Now that’s a Solid Line of Thinking!!! Come visit Ultra Infiltrant in booth #639. UNION PROCESS, INC. Akron, OH Attritor mills for fine grinding, flaking or mechanical alloying of metal powders are displayed. Attritors are ruggedly constructed
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and designed with interchangeable components to meet a variety of processing requirements, wet or dry. Sizes range from research to production sized mills. Systems for grinding under inert gases or cryogenic grinding and metal-free grinding are offered. UNITED STATES BRONZE POWDERS, INC. Flemington, NJ Major global producer of non-ferrous metal powders and flakes, including aluminum, aluminum premixes, copper, copper alloys, bronze premixes, nickel silver, infiltrants, and tin. Subsidiaries are AMPAL, Inc., Palmerton, PA; Makin Metal Powders, Ltd., United Kingdom; and Poudres Hermillon, France. UTRON, INC. Manassas, VA UTRON is an award winning R&D company with an exemplary history of providing advanced technological innovations to NASA, DOE, NSF, the Army, the Navy, and other organizations. We have pioneered the development and application of Combustion Driven Compaction and developed a set of globally unique technologies that are providing revolutionary improvements in materials and materials processing. The text in this Exhibitor Showcase has been provided by the exhibiting companies and has not been edited for style or content by the Journal editors.
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GLOBAL REVIEW
POWDER METALLURGY IN DENMARK, FINLAND, AND SWEDEN Jan Tengzelius* and Olle Grinder**
INTRODUCTION Denmark, Finland, and Sweden together have only about 20 million inhabitants. Some key figures (2007) for the Nordic PM companies are: • invoiced sales: about US$7.5 billion, a substantial increase from US$2.6 billion in 2001. • employees: 26,000 • R&D expenditures: 4%–5% of invoiced sales Globalization is of major importance and a key issue for the Nordic PM companies, due to several compelling factors: • the export share on average is as high as 95% • a significant part of the Nordic PM industry has international owners • several companies have large global production facilities • about 50% of all employees work outside the Nordic countries • the largest PM companies support R&D globally, for example, doctoral studies at technical universities and research institutes.
The powder metallurgy (PM) industry in the Nordic countries Denmark, Finland, and Sweden has for many years had a unique and strong position internationally. Globalization of the PM industry has further been strengthened in recent years due to acquisitions and investments in new production facilities and R&D activities outside these three countries. Strong sectors in the cited countries are the production of iron and steel powders, cobalt and nickel powders, inert gas-atomized high-alloy powders, fully dense highspeed steel and tool-steel products, cemented carbides and hot and cold isostatic pressing equipment.
Metal Powders There is a comprehensive production of primarily ferrous and carbide powders for different PM applications in the Nordic countries. The powders are used in-house in the case of the production of cemented carbide parts, and fully dense high-speed-steel (HSS) and tool-steel products. Powders for sintered steel components, metal injection molded (MIM) parts, filters, hot isostatically pressed (HIPed) components, bearings, and surface coating are supplied by independent metal powder manufacturers. The latter will be discussed in this section, and the former in the section on hard materials and fully dense steel components, and semi-finished products. H gan s AB This group is the world’s largest manufacturer of iron and steel powders. The company also produces cobalt and nickel alloy powders for thermal coating as well as spherical magnetite particulates for copying applications. The total production in 2007 was >400,000 mt with a sales value of over EUR 600 million. The group has production facilities at eleven locations close to all major markets in America, Asia, and Europe. The headquarter of the company is in Höganäs, Sweden. This is also *Technical Director, H gan s AB, SE-263 83 H gan s, Sweden; E-mail:
[email protected]; **Managing Director, PM Technology AB, Drottning Kristinas v g 48, SE-114 28 Stockholm, Sweden; E-mail:
[email protected]
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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where the global development center is located. Over several years the company has set up Technical Centres in Höganäs (Sweden), Johnstown (U.S.), and in Shanghai (China) with the objective of providing technical services and R&D capabilities close to its customers. The water-atomization plant in Sweden is situated in Halmstad about a one-hour drive north of Höganäs. The plant has a 50 mt electric arc furnace, Figure 1. The atomized powder is transported with specially designed trucks from Halmstad to Höganäs for further processing. There are three plants in Höganäs. One plant is for the production of sponge iron powder. In this plant three tunnel kilns operate continuously. In the factory for annealing of iron powders a number of annealing furnaces produce plain iron powders based on both sponge powder and water-atomized powders. The third plant in Höganäs manufactures lowalloy powders such as diffusion-alloyed powders and fully prealloyed powders (Astaloy™ grades) as well as powder mixes without organic bonding, and as bonded mixes under the trade name Starmix®. Outside Sweden the company has fully integrated production plants for iron powder and lowalloy steel powders in Brazil, India, and the U.S. Powder mixes and bonded powder mixes (Starmix®) are produced at the plants in Brazil, China, India, Japan, and the U.S. High-alloy steels such as stainless steel powders and metal powders for thermal-spray coating are produced in Belgium, the UK, and the U.S. Examples of development during the last years are bonded powder mixes (Starmix®), chromium-
Figure 1. Sampling of steel melt before water atomization at the Halmstad Steel Plant. Höganäs A, Sweden
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alloyed powders (Astaloy™ CrM and Astaloy™ CrL), high-density PM steels and soft magnetic composites (Somaloy®). The Somaloy® technology creates unique soft magnetic properties in components which result in low energy losses and the opportunity to design electrical machines that are both smaller and lighter than conventional designs using electrical steel laminates. Many new soft magnetic applications have been developed together with customers and end users using the Somaloy® technology. One example of this is a core for an ignition coil, Figure 2. This coil requires a high voltage which has been achieved using the soft magnetic composite material. The coil is mounted in a 320 hp natural-gas engine used in commercial vehicles and buses. This ignition system is produced by the Opcon Group based in Åmål, Sweden. Another example is a servo motor developed together with ABB Sace S.p.A. in Italy. This electrical motor utilizes the three-dimensional design flexibility offered by PM to reduce the manufacturing cost compared with the use of electrical steel laminates, Figure 3. It is a brushless servo motor with permanent magnets. Decisive factors in selecting the Somaloy® technology instead of conventional laminates were the lower energy losses and the ease of assembly of the motor.
Figure 2. Ignition coil for a 320 hp natural gas engine. Opcon Group AB, Sweden
Figure 3. Servo motors with Somaloy® components. ABB Sace S.p.A., Italy
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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When it comes to grinding or flaking metal powders, Carpenter Powder Products AB Carpenter Powder Products AB, owned by Carpenter Technology, Inc., is one of the leading global producers of gas-atomized metal powders. The production program covers iron-base alloys including stainless steels, tool steels, and HSS, as well as nickel and cobalt-base alloy powders. Carpenter Powder Products AB atomizes from two different tundish systems. One is the plasmaheated tundish in 5–6 mt batches, which produces a clean material with low oxygen and slag contents, and the other is the standard tundish. The atomized powder is screened or air classified and used in various applications, such as HIPing, MIM, plasma transferred arc (PTA) welding, and in thermal spraying. A majority of the powder (primarily tool steel, HSS, and stainless steel) is consolidated by HIPing into near-netshape (NNS) products, billets, bars, and hollows. OMG Kokkola Chemicals Oy This Finnish company belongs to the OM Group, Inc. It is a diversified global developer, producer, and marketer of value-added specialty chemicals and advanced materials that are essential in complex chemical and industrial processes. Key technology-based end-use applications include affordable energy, portable power, clean air, clean water, and proprietary products and services for the microelectronics industry. The OM Group is the largest producer worldwide of cobalt products. Production last year amounted to 9,100 mt, of which an important part was fine cobalt powder for cemented carbides, diamond tools, and PM. Headquartered in Cleveland/Ohio, the OM Group operates manufacturing facilities in Africa, the Americas, Asia, and Europe. Norilsk Nickel Harjavalta OY OJSC MMC Norilsk Nickel, Russia, last year acquired the OM Group’s nickel business including the Harjavalta nickel-refining facilities in Finland. This company is now renamed Norilsk Nickel Harjavalta OY and is the largest producer worldwide of nickel and palladium and also a major producer of copper and platinum. Norilsk Nickel Harjavalta OY has a large production capacity for nickel powder for PM applications. PM PARTS PRODUCTION PM parts manufacturing companies in Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
Think Union Process Heavy Duty Attritors SC-30 The “SC” Series with tapered tank is the ideal choice for grinding tungsten carbide.
SDL-30 This dry grinding “batch” mill is specially designed for cryogenic grinding.
• Union Process manufactures a variety of wet and dry grinding mills for size reduction, mechanical alloying and flaking of metal powders • Mills can be equipped for milling in inert atmosphere or liquid nitrogen • Full range of mills offered from lab size to full production • Lab and pilot plant test facility available
We provide solutions for all your grinding needs.
Contact us today! Phone (330) 929-3333 Fax (330) 929-3034 www.unionprocess.com © 2008, Union Process, Inc. All rights reserved. 108-25
Expanding the Possibilities For Size Reduction
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Scandinavia are of medium size and the applications cover a wide range of component and material types. Four of these companies are in Sweden and three in Denmark. A short description of these companies and their most recent developments are cited. GKN Sinter Metals AB, Kolsva GKN Sinter Metals AB in Kolsva is responsible for the Scandinavian market within the group. Primary customers are found within the automotive/truck industry and its sub-suppliers. The latest technology in, for example, sintering furnaces is used to produce high-strength structural components with close dimensional tolerances, Figure 4. In addition to full-scale in-house capability for PM parts manufacturing, Scandinavian customers are supported by other GKN capabilities for PM filters, PM bronze bearings, forged PM and MIM parts. GKN’s technical center includes an advanced materials laboratory, and design, simulation, and validation capabilities. SKF Mekan AB SKF Mekan AB in Katrineholm develops, manufactures, and markets bearing houses and bearing components for use in machines and industry, where SKF bearings are built-in. The major activity is casting, with an annual capacity of 24,000 mt. The manufacture of sintered components is primarily for use in bearings but the company also supplies industries outside SKF with PM parts. The production level is ~8 million PM components annually. Recently the company initiated commercial production of high-density components using high-velocity compaction (HVC). This new technology is used for components requiring high density and high mechanical strength. The company focuses on this technology in order to manufacture components in competition with other technologies such as casting and machining.
Figure 4. New sintering furnace at GKN Sinter Metals, Kolsva plant
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Callo AB Callo AB is a family-owned company producing structural components, sintered filters, and PM bearings. Their growth has been over 15% per year during the last two years. Through the development of furnaces and control of sintering atmospheres, the company manufactures parts made from low-alloy chromium steel with close dimensional tolerances and precise carbon control. The sintering system is also suitable for sinter hardening of chromium-alloyed steels. The sinter-hardened chromium steels reach the same mechanical performance as those made from quenched and tempered nickel–molybdenum steels. Figure 5 illustrates a hardness profile of a case-hardened component made by Callo. Metec Powder Metal AB Metec is a new company utilizing HVC technology developed by Hydropulsor AB. For structural components they use either the HVC or the highvelocity repressing (HVR) system. The latter utilizes high-velocity repressing technology which can achieve a density of 7.7 g/cm3. The company also has a process for the production of high-density stainless steel parts in which agglomerated gas-atomized 316L powder is compacted by HVC and sintered at 1,385°C. The company claims that by using this process for stainless steel, EN minimum values are exceeded for 316L bar materials in relation to tensile strength, impact toughness, proof strength, elongation, and reduction of area. FJ Sintermetal A/S FJ Sintermetal is an established PM parts manufacturer in Denmark and the company recently acquired a plant in Sweden (part of Viking Sewing Machines AB). They are active in PM structural parts manufacturing, soft magnetic components,
Figure 5. Hardness distribution in a case-hardened component produced from Astaloy™ CrM. Callo AB, Sweden
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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and wear-resistant materials. Recently the company launched two new wearresistant materials, Weardens® and Wearcomp®. The first material is an HSS with which net-shape components can be produced having a high density and hardness. It is especially suited for tools for wood cutting and also for wear-resistant parts in hydraulics. A cross section of the structure of Weardens® is shown in Figure 6. The second material is a metal matrix composite (MMC) and consists of a low-alloy steel reinforced by a high-alloy steel and hard particles. It is sinter forged to full density and the material is suitable for wear components in forestry, the minerals industry, and in recycling. Sintex A/S Sintex was founded by Grundfos A/S in 1997. Since then the company has grown at a rate ~25% per year. Sintex applies PM technology in four principal areas: stainless steel sintering, magnet manufacture, high-velocity oxygen fuel (HVOF) thermal spraying, and MIM, Figure 7.
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
One MIM component produced by the company had been previously deep-drawn which required 14 processing steps. By manufacturing the same component by MIM the number of processing
Figure 6. Scanning electron micrograph of Weardens® material for use in woodcutting tools. FJ Sintermetal A/S, Denmark
Figure 7. MIM stainless steel locker parts. Sintex A/S, Denmark
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steps was drastically reduced and, as a consequence, so was the manufacturing cost. For stainless steels, airbag nozzles with extremely tight demands on tolerances are a major product. The nozzles require a maximum tolerance width of 0.03 mm and are automatically inspected at 16 locations within 1.5 s. Magnetic components based on both soft magnetic composite (SMC) materials and hard magnetic materials of sintered as well as plastically bonded powders are produced. Applications for these materials include electrical appliances, transformers, sensors, and ignition systems. Dansk Sintermetal A/S Dansk Sintermetal was established in 1959 and is producing PM components made of a wide range of materials such as low-alloy steels, stainless steels, copper-base alloys and soft magnetic materials. For many years stainless steel PM parts have been a specialty of this company, and Dansk Sintermetal is one of the largest producers of these types of components in Europe. MAGNETIC MATERIALS Neorem Magnets OY, Finland This company is the second largest producer of sintered NdFeB permanent magnets in Europe after Vacuumschmelze GmbH & Co. KG, Germany. The Neorem Group consists of Neorem Magnets Oy in Ulvila and Neorem Magnets Ningbo Ltd., Co. Established in 2004, it is located in NIP, Nordic Industrial Park, Ningbo, China. Vacuumschmelze acquired a majority (>90%) of Neorem Group in June 2007. Neorem has a strong market position in large NdFeB magnets and subassemblies in Europe with a turnover of about US$30 million in 2008. The company specializes in permanent magnets for large motors (marine and elevator) and generator applications (wind energy). Neorem recently completed an US$8 million expansion program which increased its capacity to 400 mt of large magnets and magnet subassemblies. A new expansion program has already been started with the objective of increasing annual capacity to 850 mt, depending on market demand. FULLY DENSE STEEL COMPONENTS AND SEMI-FINISHED PRODUCTS Erasteel Kloster AB Erasteel Kloster AB, Söderfors, Sweden, is
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maintaining its leadership in PM ASP® HSS and ASP® tool steels for various applications. The process route of inert-gas atomization, encapsulation, HIPing, and subsequent hot and cold forming has been continuously improved and today produces the cleanest PM materials available. Dvalin™ is an innovative process developed within Erasteel to achieve significant low levels of nonmetallic inclusions and oxygen content resulting in higher toughness, less chipping at the cutting-tool edge, and fewer interruptions in EDM tool manufacturing. The large batch size of 10 mt guarantees uniform powder characteristics. As a complement to consolidated PM steels, Erasteel markets and sells powders. A variety of HSS grades, tool steels, stainless steels, and lowalloy steels are manufactured in Söderfors. The company offers high flexibility in meeting tailormade chemical analyses for customers. A significant investment has recently been made in a second flexible-gas-atomization unit. Flexiplant™ is now serving the market need for smaller batches from 500 kg to 1 mt in addition to R&D activities. Melting under a protective gas atmosphere, or in vacuum, and other metallurgical capabilities make it possible to produce grades in iron, nickel, and cobalt-base materials with high quality demands. Applications are many and examples include centrifugal casting, NNS parts, thermal spray, MIM, and standards for chemical analysis in various industries, for example, plastics, oil and gas, nuclear, pulp and paper, and automotive. Damasteel AB Damasteel AB, Söderfors, Sweden, manufactures HIPed PM damascene steels in flat or round bars for design-oriented handicraft companies, artists, and industries around the world. The company uses different grades of high-alloy steels that are premixed in several ingenious ways to obtain the different patterns. This modern damascene steel art is now found in many aesthetically designed products such as hunting and fishing knives, hunting firearms, jewelry, ornaments, cutlery, chef's knives, and golf clubs. One example of a decorative steel product is the mallet (gavel), Figure 8. Bodycote Hot Isostatic Pressing AB Bodycote Hot Isostatic Pressing AB, Surahammar, Sweden, is part of the Bodycote Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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2009 International Conference on Powder Metallurgy & Particulate Materials June 28–July 1, The Mirage Hotel, Las Vegas
• International Technical Program • Worldwide Trade Exhibition • Special Events
For complete program and registration information contact: INTERNATIONAL
METAL POWDER INDUSTRIES FEDERATION APMI INTERNATIONAL 105 College Road East Princeton, New Jersey 08540 USA Tel: 609-452-7700 ~ Fax: 609-987-8523 www.mpif.org
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Figure 8. Damascene steel gavel. Damasteel AB, Sweden
Figure 9. Duplex stainless steel HIPed manifold. Bodycote Hot Isostatic Pressing AB, Sweden
International Group. The group has over 8,000 employees worldwide and is divided into two divisions: the Thermal Processing division embraces heat treatment, HIPing, and coating activities, while the Testing Group, the second division, has vast know-how in relation to a wide range of materials. The plant in Surahammar specializes in HIPing. In total, the HIPing component of Bodycote operates a total of 11 plants of which seven are situated in Europe and four in North America. Since 1984, the plant in Surahammar has developed unique know-how for the design of both simple and complex PM components by different techniques for shaping plate into cans/capsules. They are the PM specialists in the group and have the largest HIPing unit in Europe. The company has 70 employees. It consumed 2,500 mt of high-alloy steel powder in 2007 and this number is expected to increase to 6,000–7,000 mt over the next few years. In 2007 Bodycote invested in a new workshop for capsule manufacturing in Surahammar. Next came the investment in a new HIP unit which was ordered last year and will be in operation in 2010. During 2008 and 2009 the plant will continue to Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
expand and prepare to install one of the largest hot isostatic presses in the world. The plant in Surahammar will double its turnover in the next 2–3 years. The company is expert in PM HIPed components for the tooling, oil and gas, marine, paper, and energy industries. Figure 9 illustrates an asHIPed manifold manufactured from a duplex stainless steel. Sandvik Powdermet AB Based in Sweden, Sandvik Powdermet AB focuses on materials technology by producing HIPed NNS PM components ranging in weight from 100 g to 15 mt in HSS, stainless steel, nickel, and chromium-base alloys and MMCs. Sandvik Powdermet AB is expanding applications for HIPed NNS products through development of the manufacturing technology for components with highly complex geometries. Important advantages with the HIP production of NNS components are fast delivery and tailor-made properties. Owned by Metso until 2006, Sandvik Powdermet AB is now part of the Sandvik Group, which has 46,000 employees, representation in 130 countries, and sales in excess of US$13 billion. Sandvik Powdermet AB is a part of Sandvik Materials Technology AB, which is a global developer of advanced alloys and ceramic materials that serves a range of industries with innovative products and system solutions. Examples of products are manifolds, pump casings, valves, special fittings, and pieces for three-phase fluid-measuring devices in subsea installations. In studies conducted together with SINTEF in Norway, it has been found that the inherent fine homogenous microstructure of HIPed steels is advantageous in several aspects, one of which is limited sensitivity to hydrogen-induced stressedcorrosion cracking (HISCC). HIPed PM components have a clear advantage over conventional castings or forging in subsea installations and this has resulted in a significant increase in the demand for HIPed products over the last 2–3 years. Overall the market for HIPed NNS components made and supplied by Sandvik Powdermet has more than doubled over this period of time. Kanthal AB Kanthal AB, fully owned by Sandvik AB, is a producer of materials and systems for generating, controlling, and protecting against or measuring
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heat. Their product line includes metallic, intermetallic, and ceramic materials. Several of these materials are processed by PM. A number of Kanthal products (for example, thermocouples, heating elements, and thermal insulation) are also used by the PM industry. Kanthal APMT is a ferritic high-temperature alumina-forming PM alloy with excellent corrosion properties and good mechanical properties at high temperatures. The alloy, which is a further development of the heat-resistant PM alloy Kanthal APM, combines the excellent heat-resistant properties of APM, with improved creep strength and stability at very high temperatures. Kanthal APMT is particularly suitable as a construction material at temperatures up to 1,300°C and is currently available in wire, rod, bar, and tube forms, and also as components produced via HIP. A range of applications includes radiant tubes, mesh belts, muffle tubes, furnace rollers, and furnace furniture. APMT furnace rollers in roller hearth furnaces offer a number of advantages including improved surface quality and lower maintenance costs, primarily due to its excellent oxidation resistance. Kanthal APM and APMT have been proven to give significant advantages in sulfidizing and carburizing environments where the alumina layer offers superior protection compared with conventional chromia-forming alloys. Uddeholm Tooling AB PM Steels: Uddeholm Vancron 40 is the latest PM development from Uddeholm Tooling. This is a nitrided PM tool steel offering a unique resistance to galling, adhesive wear, and low friction, Figure 10. Industrial experiences in Asia, Europe, and North America have demonstrated improved performance for Uddeholm Vancron 40 tools, compared with surface-coated tool steels or HSS in several cold-working applications. These include powder compacting, cold forming of mild steel and advanced high-strength steel (AHSS), blanking, and forming of stainless steel. Superclean 3, the third generation of PM tool steels and high-speed steels, offers enhanced mechanical properties due to improved cleanliness of the powder. This is achieved during the refining process in the large tundish prior to gas atomization. The size and the size distribution of the powders are smaller compared with powder from other producers. All the Uddeholm VANADIS
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Figure 10. Scanning electron micrograph of nitrogen-alloyed (1.8 w/o N) Vancron 40 tool steel for cold-forming operations. Uddeholm Tooling AB, Sweden
and Uddeholm ELMAX grades are processed according to the Superclean 3 process. Spray-Formed Steels: Uddeholm Tooling is the only company that offers tool steels produced commercially via spray forming, a process in which molten steel is sprayed on to a rotating disc forming a solid billet. The spray-formed billet can have dimensions up to 500 mm dia. × ~2 m in length with a weight of 3.5 mt. The billets are then forged, rolled, heat treated, and machined before the finished bars are delivered to market. Today two spray-formed tool-steel grades are produced; Uddeholm Weartec SF, a spray-formed high-vanadium tool steel offering excellent abrasive-wear resistance, and Uddeholm Sverker SF, a spray-formed AISI D2, in which the carbide size is smaller than that in conventionally produced tool steels. This results in an excellent combination of wear resistance and ductility. HARDMATERIALS Sandvik The Sandvik group is the largest cemented carbide producer in the world. Sandvik Tooling, with 16,400 employees, invoiced sales in 2007 were ~US$3.92 billion. A majority of the cemented carbide operations takes place within Sandvik Coromant AB and Sandvik Hard Materials AB. The latter company supplies a wide range of cemented carbide products from manufacturing plants around the world; these include: • Engineered Components: carbide rotary cutters for the nonwoven industry, tools for the Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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can industry, and rolls for the steel industry. • Tool Blanks or Semi-finished Products for the toolmaking industry for use in cutting and forming metals, composite materials, wood, brick, concrete, and rock. • Wear Parts for diverse applications in metal cutting, mining, mineral and civil engineering, agriculture, food processing, textiles, and other industrial sectors. Sandvik Coromant AB focuses on cutting tools and tooling systems with production plants in Sweden and additional local production in 10 countries throughout the world. Sandvik Coromant AB is highly export oriented, with 97% of its sales outside Sweden. It also provides specialist service to customers in 60 countries. The company has further developed the Coromant Recycling Concept which is a global recycling service for used carbide inserts and solid carbide tools. Six percent of the annual turnover is invested in R&D, in order to develop new workpiece materials and also new machining concepts and methods. This extensive activity results in a constant flow of patents covering new tools and cutting grades. For several years, about 25%–40% of all new patents linked to cutting tools issued in the U.S. were assigned to Sandvik Coromant. R&D work is concentrated in Sandvik Tooling’s Research and Technology Center in Stockholm. Operations have been expanded successively with new equipment, new processes, and more staff, and today is the world’s largest entity of its type. This extensive R&D effort has resulted in a constant flow of new products based on new cutting tool materials, new insert geometries, and tool designs. This gives improved cutting performance resulting in improved productivity and an attendant decrease in production costs. Some recent examples of new products are: • P25 grade GC4225 with enhanced turning performance, Figure 11 • CBN and ceramic machining grades • milling grades for steel and cast irons • high-pressure coolant system for chip control and extended tool life • development of new tooling concepts for highspeed machining Sandvik Mining and Construction (SMC) is a business area that incorporates several companies which together constitute the world’s largest producer of carbide tools for rock excavation.
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
Figure 11. New P25 grade GC4225 turning tools with enhanced machining performance. Sandvik Coromant AB, Sweden
Seco Tools AB Seco Tools AB, Sweden, is the fourth-largest cemented carbide tool manufacturer in the world with production plants for machining tools in the Czech Republic, India, Italy, and Sweden. The head office is located in Fagersta, Sweden. The tools are used in different machining operations, namely, turning, milling, and drilling. Tool materials include cemented carbides, cermets, cubic boron nitride, polycrystalline diamond, and HSS. Seco Tools AB has 4,660 employees, of whom nearly 1,580 work in Sweden. Sales in 2007 amounted to nearly US$1.0 billion. Recently the company introduced a new chemical vapor deposition (CVD) technology to deposit alpha-alumina with a controlled texture. Utilizing CVD, the growth of alpha-alumina can be directed, for example, along the c-axis. As shown in Figure 12 the alumina layer is composed of columnar grains grown primarily along the c-axis, thus orienting the basal planes parallel to the substrate. These textured alumina layers exhibit enhanced wear resistance and toughness compared with earlier alumina-coated grades. The technology is referred to as “Duratomic™”. This coating has been successful on new turning grades, such as TP2500, and milling grades, such as MK3000. Atlas Copco Secoroc AB Atlas Copco Secoroc AB is one of the world’s largest manufacturers of percussive and rotary rock-drill tools. The company has production facilities in South Africa, Sweden, and the U.S. The cemented carbide bits used in the drilling tools are manufactured from tungsten carbide and cobalt powder at the main factory in
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studs. As a result of technical innovations by Tikomet, both the purity and particle-size distribution of the powders produced by the zincreclaim process have improved considerably. Therefore, the use of zinc-reclaim powders is expected to increase in traditional applications and also to widen to embrace new applications.
Figure 12. Scanning electron micrograph of new multi-layered coating (Duratomic™) for turning and milling cemented carbide grades. Total coating thickness 10 µm. SECO Tools AB, Sweden
Fagersta, Sweden, and also in Springs, South Africa. Tikomet Oy Tikomet Oy, Jyväskylä, Finland, is a company specializing in the production of WC-Co powders by the zinc-reclaim process. Traditionally the bulk of the production has been sold to a Finnish sister company producing cemented carbide pins for tire studs. Tikomet has just completed the construction of a new 600 mt/year zinc-reclaim powder plant, tripling the production capacity of the company and making it the European market’s leader in this area. The plant sets new standards in the areas of zinc furnace technology and powder production technology. This expansion allows Tikomet to offer its services to external customers interested in buying zinc-reclaimed powders for the production of cemented carbide tools or having their cemented carbide tool scrap converted into powder. The decision to build a new modern plant was motivated by the strong interest by the industry in the recycling of used cemented carbide tools which have become economically attractive after the price of tungsten tripled in 2005 and has remained at a high level since then. Furthermore, there is a desire to reduce the dependence on China for tungsten raw materials. Traditionally, the use of powders produced by the zinc-reclaim process has been limited to applications such as indexable insert grades and tire
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DIAMOND TOOL PRODUCERS Several Nordic companies produce diamond and superhard materials such as CBN tools by PM methods for the mining, exploration, engineering, and industrial construction sectors. The product program is vast, comprising: • diamond core drill bits for exploration drilling and hole making in reinforced concrete, concrete, and tiles • diamond saw blades and saw wires used in dry or wet cutting of reinforced concrete, concrete, asphalt, brick, and stone • engineering products for grinding (such as cemented carbide products), honing, machining, and polishing. Atlas Copco Craelius AB is arguably the biggest producer of diamond tools for exploration and ground investigation drilling in the world. Production facilities are located in Canada, China, South Africa, and Sweden. As a result of recent intensive R&D, these tools can now be made by a unique production process. New designs and metallurgy have also resulted in tools for extremely hard rock formations and long life for deep hole drilling. The cutting part of the tool consists of a mixture of metal powders and synthetic diamonds, infiltrated with a copperbase braze. Figure 13 shows diamond core drills from Atlas Copco Craelius AB.
Figure 13. Diamond core drills. Atlas Copco Craelius AB, Sweden
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Diamond tooling is produced by several companies including Dimas AB and Sandvik Nora AB. PM PROCESS EQUIPMENT AND TECHNOLOGY Result Press AB Result Press AB manufactures hydraulic presses for powder compaction of hardmetals, ceramics, and sintered-steel components. The manufacturing facility is located in Härnösand, north Sweden. Hydropulsor AB This company was founded in the mid-1990s and utilizes adiabatic softening technology originating primarily as a result of military applications. With a new hydraulic system it was found possible to manufacture high-velocity compaction presses for PM components. The company manufactures four sizes of hydraulic presses. The smallest one, HYP35-02, has a compaction energy of 2 kNm corresponding to 100 mt and the largest one, HYP35-40, has a compaction energy of 40 kNm which is equivalent to ~2,000 mt. Avure Technologies AB Avure Technologies, Västerås, Sweden, the world’s leading supplier of isostatic presses, has produced presses for HIPing and for cold isostatic pressing (CIPing) in its Swedish and U.S. facilities since the early 1960s. The former ABB/ASEA company now operates as an independent corporation with a global footprint. The largest share of this rapidly growing US$65 million company is located in Sweden where its manufacturing, R&D, engineering, sales support, and service organization are based. In addition to isostatic presses Avure manufactures presses for sheet-metal forming for the automotive and aerospace industries, and for microbiological reduction and food safety improvement in the food industry. Over the years Avure has made large investments in supporting continuous advances in isostatic pressing equipment design and processing. This has resulted in decreased cycle times and higher product throughput, longer machine life, and more durable components and attendant lower maintenance costs. Primary achievements are rapid cooling, reliable furnace designs, loading and unloading vessel options, and optimization of support system and process control functionality. The paradigm shift we are now seeing in the industry is the realization of extremely large HIP Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
presses allowing batches of 20–40 mt of material to be processed in a 12–16 h cycle. This reduces the cost of the HIPing process to
Figure 14. DMLS dental products. EOS Finland OY
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biomedical materials such as titanium and cobalt–chrome alloys. In addition, there are many materials that have been developed for evaluation purposes, awaiting industrial application. The surface quality, mechanical properties, detail resolution, and flexibility of the DMLS process have improved to the point where applications have increased from tooling and prototyping to the direct manufacture of customized biomedical implants, surgical devices, dental restorations, and demanding aerospace and automotive components. It is expected that the number and range of applications will continue to expand. In particular, the trend towards using laser sintering for batch production of end-use parts and spare parts will increase, Figure 14. R&D ACTIVITIES The level of R&D in PM in Scandinavia is extensive. These activities include hardmetals, sintered steels, and fully dense PM steels. The largest share of R&D is carried out by the PM industry, but institutions such as Swerea KIMAB AB, Chalmers, and KTH are important contributors in the creation of new PM knowledge. The PM industry in Scandinavia spends between 4% and 5% of its turnover on R&D which is a high figure compared with the steel industry, which averages ~1.5%. A reason for this difference is that PM is less mature than the conventional steel industry and combines material-manufacturing and component-forming processes. A comparison can also be made with the automotive industry which spends ~6% of its turnover on R&D. A “snapshot” of R&D at research/academe institutions includes: Chalmers University of Technology PM research comprises a significant part of the activities in the Department of Materials and Manufacturing Technology. The yearly budget for PM-related research is close to EUR 1 million. The overall focus is on the correlation between processing, microstructure, and properties of PM materials, and product performance, Figure 15. Of particular concern are the chemical characteristics of metal powder surfaces and how these characteristics can be studied and tailored for improved product performance. Here, equipment for advanced surface chemical analysis such as X-ray photoelectron spectroscopy (XPS) and Auger spectroscopy is used. With the newest scanning
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Figure 15. Simulation of phase transformation during cooling of material based on Astaloy™ CrM from 1,120°C at 0.5°C/min. Composition: 96 w/o Fe, 3 w/o Cr, 0.05 w/o Mn, 0.5 w/o Mo, 0.45 w/o C. Grain size 140 µm. The simulation uses JmatPro software. Chalmers University, Sweden
Auger nanoprobe, surface chemical analysis of features down to 10 nm in lateral dimensions is possible. Other characterization tools include scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). Forming techniques including novel slurry methods such as starch consolidation and powder injection molding (PIM). New ways of improving the properties of ferrous sintered parts by means of materials design and process optimization for liquid-phase sintering (LPS) are addressed. This area includes both persistent liquid-phase sintering (PLPS) and supersolidus liquid-phase sintering (SSLPS) of HSS. PM intermetallics for high-temperature applications are synthesized, including iron aluminides and molybdenum silicides. Swerea KIMAB AB The Corrosion and Metals Research Institute in Stockholm performs research in close cooperation with the Swedish PM industry. The focus is on hardmetals, high-speed steels, tool steels, and materials for structural components. One example is phase equilibria in cemented carbides alloyed with chromium and vanadium. Small additions of these elements to cemented carbides are often used to restrict grain growth of the WC particles during sintering. The results show that both elements have a significant solubility in the cobalt-rich binder phase, both in the Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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solid and liquid phases. Chromium decreases the melting temperature of the cobalt-rich binder by ~100°C, and vanadium by ~50°C. This new information has been implemented in thermodynamic modeling, and reliable calculation of the phase relations in cemented carbides alloyed with chromium and vanadium is now possible. A tool to predict phase equilibria has been developed for this class of materials, which is also important for future modeling of the effect of chromium and vanadium on grain growth in cemented carbides, Figure 16. Another example of current research at Swerea KIMAB AB is the study of carbides in PM tool steels. The properties of PM tool steels are influenced by the type and fraction of carbides in the material. For the design of new alloys it is of interest to be able to make predictions on the role of carbides. A study of microstructures and phase compositions of PM tool steels with a high level of primary carbides after equilibrium heat treatment was made. By applying thermodynamic models
Figure 16. Optical micrograph of C-Co-Cr model alloy, heat treated at 1,450°C. The black phase is graphite, the dark grey phase is M7C3, and the white phase is fcc-Co. SwereaKIMAB AB, Sweden
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the phase compositions could be recalculated. It was found that accurate predictions of the fraction and type of primary carbides after HIPing is possible. The results can be used in alloy development in order to assess the influence of changes in alloy composition on microstructure. Activities at Luleå University in PM emphasize computer simulation for powder consolidation methods. A specific area is the simulation of metal powder die-filling processes. This work has been a part of the “Dienet” European project. VTT Technical Research Centre of Finland is located in Helsinki. There are two departments with PM activities: one is powder development, including spray drying, mechanical alloying, and gas atomization; the other is PM with capabilities utilizing HIPing, PIM, and spray forming. Royal Institute of Technology (KTH) has recently completed the research program “BRIIE” (Brinell Centre for Inorganic Inter facial Engineering), a center of excellence in PM. Current topics include: • Dry pressing of granulated powders • Rapid prototyping of hardmetal components • Direct casting of ceramic dental bridges • Transformation of austenite in sintered steels • Reactive gas transport in porous media • Carbide grain growth in cemented carbides • Solution-based gradient manufacture This program also involved Swerea KIMAB AB as a research organization and several major Swedish PM industries. The total budget was ~EUR 10 million over a period of 12 years. A new program, Vinnex HERO-M, was recently initiated with a focus on modeling of materials and the building of knowledge in databases for simulation of materials design and properties. ACKNOWLEDGEMENT We gratefully acknowledge the contributions and support received from our colleagues in the preparation of this report. ijpm
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ENGINEERING & TECHNOLOGY
STAINLESS STEEL AISI GRADES FOR PM APPLICATIONS Christopher T. Schade*, John W. Schaberl** and Alan Lawley***
INTRODUCTION MPIF Standard 351 lists the most common grades of stainless steel used by PM parts manufacturers. These include austenitic grades such as 303L, 304L, and 316L, and ferritic grades such as 409L, 410L, 430L, and 434L. However, with the continued growth of stainless steel there exist many opportunities for specialized stainless steel grades not covered by MPIF Standard 35. These include applications requiring enhanced physical properties, corrosion resistance, weldability, and machinability. There are additional grades covered by the AISI that can be manufactured by conventional press-and-sinter PM, Figure 1. The AISI designation for these alloys is well known, with the number series 200 and 300 referring to austenitic stainless steels and the 400 series covering the ferritic and martensitic stainless steels. Letter designa-
Figure 1. Available stainless steel alloy systems3
Applications requiring stainless steels are growing at a rate of about 5% annually. Opportunities for using powder metallurgy (PM) exist, but additional grades not covered by MPIF Standard 35 are required. The American Iron and Steel Institute (AISI) has standards for a broad range of stainless steels that can be used in many applications, but the compositions of these grades must be modified to be conducive to manufacture by conventional PM techniques. Several of these grades have been produced as standard press-and-sinter powders. The physical properties, mechanical properties, and microstructures of these various grades are reviewed to serve as a guideline for PM parts manufacturers and potential applications of these grades are addressed.
Presented at PowderMet2007 and published in Advances in Powder Metallurgy & Particulate Materials—2007, Proceedings of the 2007 International Conference on Powder Metallurgy & Particulate Materials, which are available from the Publications Department of MPIF (www.mpif.org).
*Manager– Pilot Plants, Hoeganaes Corporation, 1001 Taylors Lane, Cinnaminson, New Jersey 08077, USA; E-mail:
[email protected], **Plant Manager, Ancor Specialties, 2190 Montmorenci Road, Ridgway, Pennsylvania 15853, USA, ***Emeritus Professor, Drexel University, Department of Materials Science & Engineering, LeBow Engineering Building, Philadelphia, Pennsylvania 19104, USA
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tions attached to the end of the number series indicate modifications to the composition.2 Many societies, such as the Society for Automotive Engineers (SAE) and the American Society for Testing and Materials (ASTM), use the AISI specification, with the latter adding physical property specifications. 3 SAE and ASTM have worked together to create the unified numbering system (UNS) for metals and alloys, which is recognized globally and can be used as a cross-reference internationally.4 Other references covering both wrought and cast grades of stainless steel are available.5-6 There are hundreds of commercially available stainless steel compositions, fabricated by multiple processing steps which modify their properties. Fortunately, these stainless steels can be classified into several distinct categories. These include austenitic, ferritic, martensitic, precipitation hardening, and duplex stainless steels. For convenience, the development of additional PM grades of stainless steel will adhere to these categories. ALLOY PREPARATION AND TESTING The powders used in this study were produced by water atomization with a typical particle size (100 w/o) <150 µm (-100 mesh) and with 38–48 w/o <45 µm (-325 mesh). All the alloying elements were prealloyed into the melt prior to atomization, unless otherwise noted. Admixed copper, molybdenum, and nickel powders were used to make some compositions and are so designated in the tables of chemical composition. The stainless powders were mixed with 0.75 w/o Acrawax©C lubricant. Samples for transverse rupture (TR) and tensile testing were compacted uniaxially at 690 MPa (50 tsi). All the test pieces were sintered in a high-temperature Abbott continuous-belt furnace at 1,260°C (2,300°F) for 45 min in hydrogen with a dewpoint of -40°C (-40°F), unless otherwise noted. Prior to mechanical testing, green and sintered density, dimensional change (DC), and apparent hardness were determined on the tensile and TR samples. Five tensile specimens and five TR specimens were tested for each composition. The densities of the green and sintered steels were determined in accordance with MPIF Standard 42 and tensile testing followed MPIF Standard 10. Impact-energy specimens were tested in accordance with MPIF Standard 40. Apparent hardness measurements were conducted on tensile, TR, and
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impact specimens, following MPIF Standard 43. Rotating bending-fatigue (RBF) specimens were machined from test blanks that were pressed at 690 MPa (50 tsi) and sintered at 1,260°C (2,300°F). The dimensions of the test blanks were 12.7 mm × 12.7 mm × 100 mm. RBF tests were performed using rotational speeds in the range of 7,000–8,000 rpm at R equal -1 using four fatigue machines simultaneously. Thirty specimens were tested for each alloy composition, utilizing the staircase method to determine the 50% survival limit and the 90% survival limit for 107 cycles (MPIF Standard 56). Metallographic specimens of the test materials were examined by optical microscopy in the polished and etched (glyceregia) conditions. Etched specimens were used for microindentation hardness testing, per MPIF Standard 51. Salt-spray testing on TR bars was performed in accordance with ASTM Standard B 117-03. Five TR bars per alloy (prepared as previously described) were tested. The percent area of the bars covered by red rust was recorded as a function of time. The level of corrosion was documented photographically. RESULTS AND DISCUSSION Ferritic Stainless Steels For PM applications, the ferritic stainless steels are by far the most widely used grades, reflecting their application in the automotive industry. Examples are ABS sensor rings and muffler exhaust flanges. Chromium is the major alloy constituent of the ferritic grades along with minor additions of other ferrite stabilizers such as silicon and niobium (Table I). In general, the 400 series, ferritic stainless steels contain 11–27 w/o Cr, are magnetic, have moderate ductlity and corrosion resistance, and are relatively weak at high temperatures. 7-8 In order to form the passive oxide layer a minimum of about 11 w/o Cr is required. The early use of these grades was limited by the amount of carbon and nitrogen in the alloys. With higher levels of carbon and nitrogen, the ductileto-brittle transition can occur at high temperatures. However, with the advent of argon–oxygen– decarburization (AOD), lower values of nitrogen and carbon have been acheieved and the ductility of these grades has been greatly enhanced.9 The effect of carbon and nitrogen can further be reduced by the addition of niobium which comVolume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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TABLE I. COMPOSITION OF PM FERRITIC STAINLESS STEELS (w/o)
1 Covered by MPIF Standard 35
bines with the interstitial elements to prevent sensitization. Niobium is also a ferrite stabilizer which helps prevent the formation of martensite in the alloys. In general, the oxidation resistance and mechancial properties (Table II) increase as the chromium level increases. The addition of other alloying elements to the base compositions can enhance certain properties. For example, in the case of 434L, when molybdenum is added, the resistance of the alloy to corrosion by road salt is increased. Niobium is added to several stainless steel grades to prevent the formation of chromium carbides which leads to intergranular corrosion (409L, 436, and 439). This is particularly important when welding ferritic stainless steels, since the formation of chromium carbides is rapid and
difficult to avoid. Sulfur can be added to enhance the machinability of ferritic stainless steels. In AISI 416L, sulfur is prealloyed prior to atomization, and the element combines with manganese during solidification to form manganese sulfides that assist in machining. This technique has been used in the PM grade of 303L for many years. Super ferritics have been developed for increased oxidation or scaling resistance. In general, the higher the chromium content the higher the oxidation resistance. Additions of molybdenum and niobium can enhance oxidation resistance even further. Figure 2 shows that the oxidation resistance of S44626 (a super ferritic containing molybdenum) and S44100 (containing 1 w/o niobium) approach that of high chromium–nickel grades such as 310L and Hasteloy X (a superalloy).
TABLE II: MECHANICAL PROPERTIES OF PM FERRITIC STAINLESS STEELS
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Figure 2. Weight gain (in air) as a function of temperature for selected oxidationresistant alloys
Austenitic Stainless Steels The AISI 300 austenitic series stainless steels contain nickel and chromium and have excellent
corrosion resistance in diverse environments. The properties of austenite are generally described as nonmagnetic, with a relatively low yield strength, high ductility, and excellent impact toughness. Austenitic stainless steels behave in a manner similar to that of low-carbon steels but with enhanced high-temperature strength and oxidation resistance. Depending on chemical composition, these stainless steels can resist scaling up to 1,095°C (2,000°F). Conversely, austenitic stainless steels can be used in low-temperature applications where their high toughness levels are compatible with cryogenic applications. Based on Table III, there exists a wide range of 300 series stainless steels suitable for a variety of applications. This table also includes stainless steel grades commonly used by the PM industry and detailed in MPIF Standard 35, namely, 303L, 304L, and 316L. With the increased use of PM stainless parts an exploration of other grades listed in Table III would appear to be timely. There is a growing need to weld PM austenitic stainless steel parts to other structures. In doing
TABLE III. COMPOSITION OF PM AUSTENITIC STAINLESS STEELS (w/o)
1 Covered by MPIF Standard 35
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so, the normal grades of stainless steel (304L and 316L) are susceptible to sensitization, particularly in areas adjacent to the weld. Sensitization is the process by which chromium combines with carbon to form chromium carbides. The chromium is removed from areas close to the grain boundaries and leaves these areas depleted of chromium, with attendant susceptibility to intergranular corrosion. The formation of chromium carbides is enhanced by temperature and generally occurs in austenitic stainless steels at temperatures between 480°C and 815°C (900°F and 1,500°F). The cooling rate resulting from the welding process is generally slow which increases the likelihood of chromium carbide formation. Increased carbon levels due to insufficient lubricant burn-off can also increase the chance of sensitization. In order to avoid postweld heat treatment, stabilized grades of austenitic stainless steels have been developed. In order to prevent the chromium from forming carbides, strong carbide-forming elements have been added to the austenitic grades of stainless steel. In AISI grades 309Cb, 316Cb, and 321L, titanium and niobium were added for this reason. In PM products, the use of niobium is preferred because water atomization oxidizes the titanium. Table IV lists the mechanical properties of these
niobium-stabilized austenitic PM grades. In general, due to the addition of niobium and the formation of carbides, the ductility and impact toughness of these grades are slightly lower than those of the non-stabilized grades. However, in general, this decline in mechanical properties is small, and can be compensated for by an increase in the level of other elements (such as nickel and chromium). Due to the formation of the carbides, the creep resistance of these grades of stainless steel is improved. Other alloying elements, such as molybdenum, can be added to the austenitic stainless steels to improve corrosion resistance. Molybdenum, when added at levels between 2 w/o and 4 w/o, improves resistance to oxidation, pitting, and crevice corrosion. The addition of molybdenum also tends to improve both room and high-temperature properties such as tensile strength and creep resistance. The mechanical properties of AISI 317L are cited in Table IV and the corrosion resistance is illustrated in Figure 3. Currently PM fabricators sinter austenitic grades in a hydrogen/nitrogen atmosphere to increase strength (MPIF Standard 35: grades SS-304N and SS316N). In so doing, significant chromium nitride formation occurs, which is detrimental to the
TABLE IV. MECHANICAL PROPERTIES OF PM AUSTENITIC STAINLESS STEELS
Figure 3. Representative appearance of salt spray specimens: (a) 304L, (b) 316L, and (c) 317L. Magnification 75% of actual size
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Figure 4. Oxidation of 300 series stainless steels
overall corrosion resistance of the alloy. The addition of molybdenum is beneficial if both corrosion resistance and strength are required. More-highly alloyed 300 series stainless steels are available that are designed to resist oxidation at high temperatures while maintaining a high degree of tensile strength and creep resistance. These alloys rely on the formation of the chromium oxide film for protection from corrosion, but the additional nickel and silicon in these alloys helps to form a more ductile scale, which increas-
es its adherence to the base metal. The adherent scale is particularly important when service conditions involve cyclic temperatures. The properties of several of these PM grades (302B, 304L, and 310L) are listed in Table IV and the relative oxidation resistance of these grades is shown in Figure 4. As with the other categories of stainless steels, there exists “super austenitics” where increased levels of nickel, copper, and molybdenum provide superior or specialized corrosion resistance. However, for the PM grades of these alloys the increased alloy content has a negative impact on powder compressibility and therefore on overall density. In consequence, care has to be taken to ensure that the increased corrosion resistance and enhanced mechanical properties gained by the increase in alloy content are not offset by a reduction in achievable density. Type 904L stainless steel is considered a “super austenitic” stainless steel. Martensitic Stainless Steels Martensitic steels in the 400 series are similar to the ferritic stainless steels in that they contain chromium in the range of 11–18 w/o but also contain other elements such as nickel (Table V). The martensitic stainless steels are magnetic and are generally used in applications where hardness and/or wear resistance are required. When heat treated they can achieve high strength, and when tempered they can exhibit some ductility. Essentially, these steels achieve mechanical prop-
TABLE V: COMPOSITION OF PM MARTENSITIC STAINLESS STEELS (w/o)
M Designates material made from a mix of a base powder and additives such as nickel, graphite, copper, and molybdenum
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erties comparable with those of a heat-treatable low-alloy steel but with enhanced corrosion resistance, although their corrosion resistance is the lowest of any of the stainless steel categories. MPIF standard 35 recognizes SS-410-90HT as a martensitic alloy. For this grade, the sintering atmosphere contains a high level of nitrogen, and the alloys form high-temperature austenite, which transforms to martensite on cooling. Other AISI martensitic grades of stainless steel, such as 420, 440A, 440B, and 440C, can be processed by adding graphite to ferritic grades of stainless steels such as 410L and 430L. Table VI gives the mechanical properties of 420L, 440B, and 440C made by this approach. The level of carbon added to the alloy dictates the mechanical properties of the martensitic stainless steel. The higher the carbon content, the larger the extent of chromium carbide formation, and the higher the strength and apparent hardness of the alloy. A major drawback to carbon-containing martensitic stainless steels is their relatively poor corrosion resistance and ductility. Low carbon–containing martensitic stainless steels can be produced by adding nickel, molybdenum, and copper to form martensitic stainless steels with improved toughness and corrosion resistance. Table V cites the composition of several martensitic stainless steels made by adding nickel, copper, and molybdenum. Nickel and copper are austenite formers, while molybdenum improves properties via solid-solution strengthening; this element is responsible for improving high-temperature properties. While the apparent hardness of these alloys is slightly inferior to that of heattreated carbon-containing martensitic stainless steels, other mechanical properties such as tensile strength, toughness, and ductility are superior. These grades of stainless steel also exhibit
superior corrosion resistance which reflects the absence of carbide formation and hence sensitization, as shown in Figure 5. As with other categories of stainless steels, super-martensitic stainless steels can be formed by adding high levels of nickel, copper, and molybdenum. For PM alloys the prealloyed materials are usually low in compressibility but can exhibit superior corrosion resistance due to their high alloy content. Precipitation-Hardening Stainless Steels Precipitation-hardening stainless steels are not defined by their microstructure but, rather, by strengthening mechanism. These grades may have austenitic, semi-austenitic, or martensitic microstructures and can be hardened by aging at moderately elevated temperatures, 480°C to 620°C (900°F to 1,150°F). The strengthening effect is due to the formation of intermetallic precipitates from elements such as copper or aluminum. These alloys generally have high strength and high apparent hardness while exhibiting superior corrosion resistance compared with martensitic stainless steels. Heat treatments can be used to vary the properties of the alloys and involve short times (1 h) at temperatures ranging from 480°C to 620°C (900°F to 1,150°F). The aging treatment can take place in either air or in nitrogen, depending on the surface appearance required. However, these alloys should not be subjected to welding or in service temperatures above the heat-treatment temperature because strength can be lost due to overaging. The AISI designation for these alloys is the 600 series of stainless steels, but most are more commonly known by their alloy name, for example, 155PH, 17-4PH, and17-7PH. The aluminumcontaining precipitation-hardening alloys are diffi-
TABLE VI: MECHANICAL PROPERTIES OF PM MARTENSITIC STAINLESS STEELS
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Figure 5. Representative appearance of salt spray specimens: (a) 440B, (b) 440C, (c) 410Lcu, (d) super-martensitic admixed, and (e) supermartensitic prealloyed. Magnification 75% of actual size
cult to process by the PM route due to their high propensity for nitride formation and to the difficulty in reducing aluminum oxide during sintering. Tables VII and VIII give the chemical compositions and mechanical properties of several precipitation-hardening alloys produced by conventional PM techniques. 17-4PH is a martensitic grade in which ductility and toughness are generally higher than in the carbon-containing martensitic grades. The mechanical properties of 17-4PH can be increased 15% by aging at 538°C (1,000°F) for
1 h. Applications for this alloy exist in the food, chemical, and aerospace industries. 633 is a semi-austenitic precipitation-hardening stainless steel offering improved corrosion resistance compared with martensitic precipitation-hardening alloys. These alloys are used for parts requiring high strength at moderately elevated temperatures. Depending on the aging treatment, the ductility and toughness of this alloy can approach those of the austenitic stainless steels. The microstructure of the alloy is a
TABLE VII: COMPOSITION OF PM PRECIPITATION-HARDENING STAINLESS STEELS (w/o)
TABLE VIII: MECHANICAL PROPERTIES OF PM PRECIPITATION HARDENING STAINLESS STEELS
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STAINLESS STEEL AISI GRADES FOR PM APPLICATIONS
mixture of austenite, martensite, and small quantities of ferrite. Usage of the precipitation-hardening alloys is generally limited by the high cost of the alloying elements. Recently, a lower-cost PM precipitationhardening alloy has been introduced based on UNS J91151 (a cast grade).10 This alloy has only 13 w/o chromium and utilizes the precipitation of copper to provide a low-cost–high-strength alloy with moderate corrosion resistance. Table VIII shows that the mechanical properties approach those of 17-4PH, while still maintaining a level of corrosion resistance that is better than that of the high-carbon martensitic grades. Duplex Stainless Steels Technically, duplex steels are stainless steels that contain two phases.3 Duplex stainless steels are more accurately defined as alloys containing a mixed microstructure of ferrite and austenite. New alloys being developed that contain mixtures of ferrite and martensite are generally termed dual-phase.11 Compositions of PM Duplex/DualPhase stainless steels are listed in Table IX. A major advantage of these stainless steel grades is
that each phase imparts improved properties to the alloy. Duplex stainless steels are ferritic stainless steels (Figure 6(a)) containing chromium and molybdenum to which austenite formers (primarily nickel) have been added to ensure that austenite is present at room temperature. Duplex stainless steels have several advantages over the austenitic grades including high strength, acceptable toughness, and superior corrosion resistance, particularly to chloride-stress-corrosion cracking. The mechanical properties of a duplex stainless steel (2205) are shown in Table X. Dual-phase stainless steels vary in composition but are generally non-austenitic (Figure 6(b)) and magnetic, containing 11 w/o Cr. The chemistry of the alloy is balanced by ferrite formers and austenite formers. The austenite transforms to martensite upon cooling resulting in a mixture of ferrite and martensite. Because of the low cost of the alloy it is used as a replacement for plain carbon steels where increased corrosion resistance is needed. The martensite in the alloy allows the material to be used in applications requiring strength and wear resistance. The properties of a
TABLE IX. COMPOSITION OF PM DUPLEX/DUAL-PHASE STAINLESS STEELS (w/o)
Figure 6. Representative microstructures of (a) duplex stainless steel and (b) dual-phase stainless steel
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TABLE X. MECHANICAL PROPERTIES OF PM DUPLEX/DUAL PHASE STAINLESS STEELS
PM version of this stainless steel (S41003) are cited in Table X.
molybdenum results in harder martensite, which has a positive effect on fatigue strength.
FATIGUE BEHAVIOR OF PM STAINLESS STEELS Fatigue tests were performed on some of the high-strength PM alloys developed. The results of these tests, in terms of the 90% survival limit, are compared with fatigue data for other stainless steels by Shah et al.,12 Figure 7. The latter study compared the fatigue strength of various stainless steels as a function of tensile strength. The excellent fatigue response of these alloys is attributed to their high tensile strength. In general, fatigue-crack propagation rates in PM steels are high and the fatigue limit is dictated by crack initiation rather than by crack propagation. Resistance to crack initiation increases as the tensile strength increases. All the PM alloys included in Figure 7 have high tensile strengths, and therefore high fatigue endurance limits. It appears that the addition of copper, nickel, and
CONCLUSIONS • Many AISI grades of stainless steel can be made via conventional water atomization and press-and-sinter PM. These grades are not currently covered by MPIF Standard 35, but provide a range of properties and corrosion resistance that can lead to increased opportunities for PM parts producers. • These PM grades can be made as prealloys, or admixed nickel, copper, and molybdenum powders can be added to the base stainless steel. • In ferritic grades, higher levels of chromium, niobium, and sulfur can lead to improved mechanical properties, corrosion resistance, and machinability. • The addition of carbon to low-chromium PM alloys results in martensitic stainless steels with increased strength and apparent hardness. Additions of nickel, copper, and molyb-
Figure 7. Fatigue endurance limit (90% survival) of PM stainless steels as a function of tensile strength
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•
•
•
•
denum produce low-carbon martensitic stainless steels with increased toughness and corrosion resistance. Niobium, when added to PM austenitic stainless steels, improves weldability. Increases in the molybdenum content of austenitic stainless steels can increase strength and enhance corrosion resistance. Increases in chromium, nickel, and silicon levels enhance oxidation resistance. Several precipitation-hardening alloys with a range of mechanical properties, microstructures, and attendant corrosion resistance can be produced by conventional PM processes. Mixed-microstructure stainless steels exhibiting excellent mechanical properties and corrosion resistance can be produced by conventional PM processes. Fatigue response of the high-strength PM alloys is a function of their tensile strength.
5. 6. 7.
8.
9.
10.
11.
REFERENCES 1. MPIF Standard 35, Materials Standards for PM Structural Parts, 2007, Metal Powder Industries Federation, Princeton, NJ. 2. J.R. Davis, Alloying: Understanding the Basics, 2001, ASM International, Materials Park OH. 3. J. Beddoes and J.G. Parr, Introduction to Stainless Steels, 1999, ASM International, Materials Park, OH. 4. J.D. Redmond, Metals and Alloys in the Unified Numbering
12.
System, 10th Edition, 2004, Joint Publication of the Society of Automotive Engineers, Inc., and the American Society for Testing and Materials. J.E. Bringas, Stainless Steel Data Book, 1992, CASTI Publishing Inc., Edmonton, Alberta, Canada. H. Cobb, Steel Products Manual— Stainless Steels, 1999, Iron and Steel Society, Warrendale, PA. T.R. Albee, P. DePoutiloff, G. Ramsey and G.E. Regan, “Enhanced Powder Metal Materials for Exhaust System Applications”, SAE Paper No. 970281, 1997, SAE International, Warrendale, PA, USA. T. Hubbard, K. Couchman and C. Lall, “Performance of Stainless Steel PM Materials in elevated Temperature Applications”, SAE Paper No. 970422, 1997, SAE International, Warrendale, PA, USA. R.J. Causton, T. Cimino-Corey and C.T. Schade, “Improved Stainless Steel Process Routes”, Advances in Powder Metallurgy and Particulate Materials— 2003, compiled by R. Lawcock and M. Wright, Metal Powder Industries Federation, Princeton, NJ, 2003, part 2, pp. 1–13. A. Lawley, R. Doherty, P. Stears and C.T. Schade, “Precipitation Hardening Stainless Steels”, Advances in Powder Metallurgy and Particulate Materials— 2006, compiled by W.R. Gasbarre and J.W. von Arx, Metal Powder Industries Federation, Princeton, NJ, 2006, part 7, pp. 141–153. A. Lawley, E. Wagner and C.T. Schade, “Development of a High-Strength–Dual-Phase P/M Stainless Steel”, Advances in Powder Metallurgy and Particulate Materials— 2005, compiled by C. Ruas and T. Tomlin, Metal Powder Industries Federation, Princeton, NJ, 2005, part 7, pp. 78–89. S.O. Shah, J.R. McMillen, P.K. Samal and L.F. Pease, “Mechanical Properties of High Temperature Sintered P/M 409LE and 409LNi Stainless Steels Utilized in the Manufacturing of Exhaust Flanges and Oxygen Sensor Bosses”, SAE Paper No. 2003-01-0451, 2003, SAE International, Warrendale, PA 15096, USA. ijpm
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ENGINEERING & TECHNOLOGY
CONTROL OF DEFECTS IN POWDER INJECTION MOLDED ALUMINUM MATRIX COMPOSITES Faiz Ahmad*
INTRODUCTION Because of high strength and light weight, aluminum matrix composites (AMCs) offer advantages in applications such as aerospace, automotive, and the defense industries. Powder injection molding (PIM) is an established technique for producing parts of complex geometry,1 and has been utilized in the processing of intermetallics,2–3 ceramics, 4–6 and ferrous 7 and nonferrous 8–10 metal matrix composites. Studies have shown that the defects in molded parts are introduced during die-cavity filling, solidification of the molten material, and as a result of differential cooling rates within the die cavity.11–13 The cooling rate of the molding material is affected by the viscosity of the mix and any abnormal cooling rates cause defects in the molded component.14 The machine settings such as compression pressure, and melt and mold temperatures have a significant effect on the quality of the molded component. Post-molding operations such as binder removal and sintering of PIM aluminum parts have been attempted using various furnace atmospheres.15–17 Recently, PIM aluminum parts were densified using liquid-phase sintering.18 The control of defects in PIM parts can reduce rejection during molding and post-molding operations. However, the application of PIM for AMCs is a new approach and further work is needed to produce net-shaped parts. The optimization of process variables in the operation of injection/MLFM machines and subsequent process controls to produce defect-free parts was accomplished in the present study. A modified MLFM has been developed to produce larger parts while controlling19–20 fiber orientations in test samples.8,21 Mixes of aluminum powder and glass fiber were prepared with a plastic binder. Composite mixes were extrusion compounded using a twin-screw extruder22 and evaluated for rheological properties.23 This research focused on developing PIM AMC test bars from a range of mixes using conventional and MLFM devices. Defects in test bars produced by conventional molding and by MLFM were compared in light of the MLFM process parameters. Samples were characterized in relation to defects
Machine parameters and flow properties of molding materials play a significant role in controlling the quality of powder injection molded (PIM) parts. Defects in molded parts can cause rejection at the binder removal and sintering stages. In this study, aluminum matrix composites were fabricated by PIM and the origins of defects analyzed. Conventional and multiple live-feed molding (MLFM) devices were used to produce the composites and the effects of machine parameters and flow characteristics of composite mixes on the occurrence of molding defects were studied utilizing X-ray radiography and scanning electron microscopy. Microdefects present were weld lines, microvoids, internal shrinkage cracks, and ejector pin marks. The orientation of fibers was examined in samples with and without weld lines. Specimens prepared by MLFM, were defect free and exhibited highly oriented fibers at the weld line. Macrodefects such as blisters were present on the surface of test samples molded at a higher temperature. From this study, a successful PIM technique has been identified for the production of defect-free 20 mm-thick bars of aluminum matrix composites.
*Associate Professor, Department of Mechanical Engineering, University of Technology Petronas, Bandar Seri Iskandar, Tronoh 31750, Perak, Malaysia; E-mail:
[email protected]
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such as weld lines, microvoids, internal shrinkage, and surface blisters. EXPERIMENTAL MATERIALS Materials used in this research were: spherical aluminum powder with a mean dia. of 22 µm. A wide particle-size distribution of the powder (8–45 µm) assisted in achieving optimum loading of the solids;24 glass fibers, 20 µm dia. × 5.0 mm long. The physical properties of the aluminum powder were: surface area 0.315 m2/g, aluminum content 99.70 w/o, and bulk density 2.7 g/cm3. Composite mixes were prepared using a corotating twin-screw extruder.22 Rheological studies were performed on the composite mixes23 and molding experiments led to the identification of a suitable mix containing 65 v/o aluminum powder. The fibers were substituted for metal powder, maintaining a constant total solids content. The formulations of the metal powder and plastic binders used in this study are listed in Tables I(a) and I(b). Mixes MC-1, MC-2, and MC-3 were compounded with binder B-1. The latter consisted of polypropylene, microcrystalline wax, and stearic acid. Mixes MC-4, MC-5, and MC-6 were prepared with binders B-1, B-2, and B-3. Binders B-2 and B-3 consisted of polypropylene as the major component plus wax as a flow enhancer. Mixes MC-1, MC-2, and MC-3 were evaluated for the effect of fiber v/o and viscosity on the quality of the molded parts. Mixes MC-4, MC-5, and MC-6 were prepared from a different binder formulation to modify the viscosity of the mixes. MULTIPLE LIVE-FEED MOLDING PROCESS The injection molding equipment was modified19 by incorporating an MLFM device between TABLE I(a): FORMULATIONS OF COMPOSITE MIXES Composite
MC-1
MC-2
MC-3
MC-4
MC-5
MC-6
Aluminum Powder (v/o) Fiberglass (v/o) Binder (v/o)
55 10 35 B-1 515
50 15 35 B-1 770
45 20 35 B-1 826
50 15 35 B-1 750
50 15 35 B-2 810
50 15 35 B-3 1,000
Viscosity (Pa·s)
TABLE I(b): BINDER CONSTITUENTS Binder
Polypropylene (v/o)
Wax (v/o)
Stearic Acid (v/o)
B-1 B-2 B-3
67.86 78.00 87.86
22.14 22.00 12.14
10.00 ---
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the molder nozzle and the die cavity. Earlier studies 7–9 demonstrated the benefits of the MLFM device in producing thick-section plastic parts and improving the orientation of short fibers in plastic and metal matrix composites. The MLFM device consists of a two-feed system with each feed system capable of independently supplying pressure to the die cavity. The main components of the device are: a) molder barrel screw, b) packing head, and c) mold, as shown in Figure 1(a). The packing head contains two separate hydraulics and valve systems that are used to drive two pistons, each 20 mm dia. The pistons are used for shearing and packing of the molding material within the die cavity. Both pistons are controlled by a microprocessor which activates pressure valves. After the molding material is injected into the die cavity, the action of the MLFM device results in shearing of the molten material. The device can be operated in any of the following three modes: Mode 1: Both pistons can be pumped back and forth at the same frequency with a phase difference of 180°. This mode shears the molten material within the die cavity and enhances the orientation of short fibers in the molding direction. It also reduces or eliminates internal weldline defects that occur as a result of injecting the melt into the die cavity from two separate gates. Figure 1(a) shows the device illustrating shearing of the melt in the die cavity. Synchronization setting for MLFM was used in Mode 1. Mode 2: Both pistons can move in forward and reverse directions at the same frequency and in phase. This mode provides for compression and decompression of the solidifying material within the die cavity. Each piston acts like an independent packing head and together they eliminate shrinkage defects and dimensional inaccuracy in the molded parts. Shrinkage in PIM composite parts may lead to the rejection of parts during the subsequent step of binder removal. Operation in Mode 2 is illustrated in Figure 1(b). Mode 3: This reflects two-gate injection molding practice during which both packing pistons are held down under the influence of static pressure. This mode introduces weld lines in molded parts that reduce tensile strength.14 Figure 1(c) illustrates operation in mode 3. PIM AMCs A die cavity 20 mm × 20 mm × 175 mm was Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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Figure 1(a). Multiple live-feed molding device showing shearing of melt in die cavity (Mode 1)
Figure 2. Die cavity; dimensions in mm
Figure1(b). Multiple live-feed molding device showing compression/ decompression of melt in mold cavity (Mode 2)
Figure 3. PIM AMC, MC-2 test bar (Mode 3)
Figure1(c). Multiple live-feed molding device for conventional injection molding (Mode 3)
used to prepare test bars. A schematic of this die is illustrated in Figure 2. A rectangularly shaped bar was selected in the molding experiments to induce a weld line in the center of the test bar, and to identify a suitable size of mold cavity for the application of MLFM to avoid premature solidification of the melt. Two tapered sprues 8 mm to 16 mm dia. were used for injecting material into the die cavity. Large diameter sprues were used to Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
avoid premature solidification of the melt. The molding material was injected from two points to produce test bars using MLFM modes 1, 2, and 3. The depth of the die cavity was varied between 6 mm and 20 mm using nonmetallic inserts to identify a suitable thickness for application of the MLFM device in the preparation of test bars. AMC test bars were produced using the conventional and MLFM devices. A molded test bar is illustrated in Figure 3. Surface defects such as blisters were recorded separately. Optimum parameters for producing defect-free AMC test bars using the standard and MLFM methods were established after trial experiments. The resulting molding parameters are listed in Table II(a) and Table II(b). SELECTED MLFM DEVICE PARAMETERS Compression Pressure and Relaxation Pressure
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TABLE II(a): MOLDING MACHINE PARAMETERS Injection Pressure (MPa) Injection Speed (m3 s-1) Hold Pressure (MPa) Screw Speed (rpm) Back Pressure (MPa)
TABLE III: X-RAY RADIOGRAPHY INTENSITY
50 1.20 X 10-4 20 150 0.5–1
Shot size: 45 mm, Mold temperature: 60°C, Profile of barrel temperatures: 190°C–200°C–200°C–215°C–215 °C
Mix
Sample Thickness (mm)
X-ray Intensity (KV)
Exposure Time (min)
MC-1 MC-2 MC-3 MC-4 MC-5 MC-6
10 10 10 6 6 6
65 65 65 35 35 35
30 30 30 10 10 10
TABLE II(b): MLFM PARAMETERS Parameters Duration (s) Compression Time (s) Relaxation Time (s) Compression Pressure (MPa) Relaxation Pressure (MPa)
Maximum Limit
S*0
S*1
S*2
1–1.2 1–1.2 1–1.2 174 174
40 1 1 110 50
10 1.5 1 165 50
20 1.2 1 110 50
*MLFM process stages
The compression pressure (CP) used in processing the AMC mixes was varied between 68 MPa and 170 MPa. The pressure was transmitted to the melt in the die cavity by 20 mm dia. pistons. The CP profile is dependent on the sequence of the MLFM process stages and the viscosity of the composite mix. For MC-1, the CP sequence (S0-S1-S2), was varied between 70, 125, and 156 MPa. The relaxation pressure (RP) for MC-1 was maintained within 35–50 MPa. For MC-2, the pressure profile sequence (S 1-S 2-S 0) was 170, 108, and 110 MPa. The RP for MC-2 was maintained at 50 MPa. For MC-3, the pressure profile sequence was S0-S1-S2 and the piston pressure was varied between 116, 178, and 170 MPa. For high-viscosity melts (MC-5 and MC-6) the same pressure profile was used. The RP for MC-5 and MC-6 was maintained at 50 MPa. Compression and Relaxation Time Compression time (CT) for MC-1 (S0-S1-S2) was 1.0, 1.5, and 1.2 s and relaxation time (RT) was varied between 0.1, 1.0, and 1.5 s. For MC-2, CT and RT were maintained at 1s. Bars of MC-3 were processed using the same time ranges. RT for mixes MC-5 and MC-6 was in the range 0.2–0.5 s due to the high viscosity and rapid solidification of the melt in the die cavity. Mold Temperature The mold temperature has a significant impact on the quality of the molded test bars. Initially, a
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mold temperature of 110°C was used to avoid premature solidification of the highly viscous melts. Bars produced at this temperature exhibited surface defects and delayed solidification of the melt in the cavity. After trial experiments, it was found that 60°C was the optimum mold temperature. Subsequently, this temperature was used to produce moldings from all the mixes. CHARACTERIZATION OF AMC TEST BARS X-ray Radiography X-ray radiography of the molded test bars was performed to identify defects. The X-ray system (Faxitron Series, Hewlett Packard Corp., USA) produced radiation intensity in the range 35–65 kV. The technique identifies microvoids, internal weld-line shrinkage and flow lines in the test bars. Surface defects such as blisters and cracks were recorded visually and by X-ray radiography. Machine conditions selected for X-ray radiography are listed in Table III. Scanning Electron Microscopy Scanning electron microscopy (SEM) was used to characterize fiber orientation in the composite test bars with and without weld-line defects produced via conventional and the MLFM techniques. Test bars were fractured in liquid nitrogen to avoid fiber pullout from the interface and fracture surfaces were examined to determine the orientation of fibers. RESULTS AND DISCUSSION Microdefects Weld-Line Defects This form of defect was present in the bars made from all the mixes. These bars were produced by injecting the melt into the die cavity through two gates using Mode 3. Weld lines occur in the molded samples when two free surfaces of the molding materials meet inside the cavity. The Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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Figure 4(a). Weld-line defect in MC-2 test bar (Mode 3)
Figure 4(b). Test bar of MC-2 without weld line (Mode 1)
temperature of the leading surface of the melt decreases in the die cavity due to the air inside the die which is colder than the die itself. Air at room temperature enters the die when the sample is ejected before the new mix enters the die. This cools the leading surface of the melt traveling inside the die cavity causing an increase in viscosity. Due to increased viscosity at the melt front, material entering from the two gates does not mix to form a homogenous mass and this results in the formation of a weld-line defect. An X-ray radiograph showing weld lines in MC-2 is illustrated in Figure 4(a). The corresponding X-ray radiograph of a bar made in Mode 1 (MLFM) had no weld-line defect, Figure 4(b). These radiographs indicate that the macroscopic shear induced by the MLFM device has eliminated the weld-line discontinuity in the bars. X-ray radiographs of bars made from the MC-5 and MC-6 mixes in Mode 3 did exhibit weld-line defects. These were eliminated in bars produced in Mode 1 with the MLFM device. A representative SEM image of a bar produced in Mode 3 showing random orientation of fibers at the weld line is shown in Figure 5(a). The corresponding micrograph showing highly oriented fibers in the bar produced in Mode 1 is given in Figure 5(b). Microvoids MC-1, MC-2, and MC-3 were similarly analyzed. Microvoids were observed in the bars produced by the conventional molding technique, Mode 3. A representative X-ray radiograph of a MC-1 bar is shown in Figure 6(a). The presence of Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
Figure 5(a). Fiber orientation at weld line of MC-1 test bar (Mode 3). SEM
Figure 5(b). Improved fiber orientation in weld-line region of MC-1 test bar (Mode 1). SEM
the microvoids is related to the lower molding pressure used (50 MPa). Composite mixes of aluminum powder and a highly conductive filler material dissipated heat rapidly to the die cavity maintained at the lower temperature to allow solidification of the melt. A higher temperature gradient between the melt and the die cavity resulted in rapid solidification of the molding material in the die cavity and air trapped in the die cavity appeared in test bar as microvoids. However, bars produced by the MLFM device in Mode 1 demonstrated no evidence of microvoids in the molded bars; a representative X-ray radiograph of MC-3 is shown in Figure 6(b). In this case, the MLFM device was operated at 165 MPa piston pressure for duration of 3 s and this eliminated the formation of microvoids. An X-ray radiograph of MC-3 is shown in Figure 6(b).
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Figure 6(a). X-ray radiograph showing microvoids in MC-1 test bar (Mode 3)
Figure 6(b). X-ray radiograph of MC-3 test bar without microvoids (Mode 1)
Parameters for the MLFM device were developed to produce bars of MC-4, MC-5, and MC-6 without microvoids. Flow Lines Flow lines were not observed in bars produced from mixes MC-2, MC-3, MC-5, and MC-6; this was related to their higher viscosity compared with MC-1. The higher viscosity of these mixes minimized the possibility of segregation of the molding material during melt shearing in the mold, resulting in bars without flow lines. Figure 7(a) shows flow lines in bars of MC-1 fabricated by the MLFM device in Mode 1. Excessive shearinduced flow lines in the bars are attributed to a low viscosity, namely 515 Pa·s for MC-1. The low viscosity of MC-1 resulted in segregation due to excessive macroshear induced by the MLFM 24 device. However, flow lines were not observed in MC-2; this was related to its higher viscosity. MC3 also did not exhibit flow lines; a representative X-ray radiograph is shown in Figure 7(b). Flow lines were not observed in bars of MC-2 produced by injecting material into the die cavity through a single point, Mode 3, Figure 7(c). Moldings of MC5 and MC-6 were without flow lines. The viscosity of MC-6 was >1,000 Pa·s and a maximum piston pressure of 178 MPa was insufficient to shear the melt in the die cavity. Bars developed using the standard molding technique, Mode 3, were also without flow lines. Internal Shrinkage Cracks Internal shrinkage cracks in a bar prepared from MC-1 are shown in Figure 8(a). These cracks
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are attributed to nonuniform shrinkage of the melt during solidification inside the die cavity. The melt was sheared at a high piston pressure of 170 MPa and this resulted in stresses on the solidifying melt. The analysis of these stresses is complex due to multiple constituents in the melt, each with different characteristics. The filler materials, powder and fibers, differ in size and thermal conductivity from the balance of the ingredients in the mix. This gives rise to differential solidification of the mix in the steel die held at a temperature lower than the melt temperature. Attendant complex heat transfer results in nonuniform shrinkage, leading to the development of internal cracks.11–12 A reduction of the molding pressure to 165 MPa eliminated shrinkage defects in MC-1, as shown in Figure 8(b). Ejector Pin Marks Ejector pins are used for the ejection of molded parts from the die cavity for subsequent operations such as binder removal and sintering. Ejector pin marks are visible in all the X-ray radi-
Figure 7(a). X-ray radiograph of MC-1 test bar showing flow lines (Mode 1)
Figure 7(b). X-ray radiograph of MC-3 test bar without flow lines (Mode 1)
Figure 7(c). X-ray radiograph of MC-2 test bar without flow lines (Mode 3/single feed)
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Figure 8(a). X-ray radiograph of MC-1 test bar showing internal cracks
Figure 9(a). X-ray radiograph of MC-1 test bar showing surface blister
Figure 8(b). X-ray radiograph of MC-1 test bar without internal cracks
Figure 9(b). X-ray radiograph of MC-2 test bar without surface blister
ographs of the molded bars. Force applied by the ejector pin develops residual stresses in the molded bars which, on binder removal, may lead to part rejection. This defect can be minimized by using mechanical devices to remove the parts from the die cavity, eliminating the need for ejector pins. MACRODEFECTS Surface Blisters Blisters on the surface of a MC-1 bar are shown in Figure 9(a). This defect occurs as a result of high mold and melt temperatures. A mold temperature of 110°C was used in the initial processing of composites MC-1 and MC-2. This temperature was selected to avoid premature solidification of the melt in the sprues but was higher than the melt temperature of the binder constituents. This melt temperature caused degradation of the lowtemperature constituents in the binder and the gases evolved were trapped in the bar during solidification of the melt. Blisters appeared on the surface of the molded bar immediately after it was ejected from the die cavity. This defect was particularly pronounced in the low-viscosity mix MC-1 and is related to the gas trapped in the bar processed at a high pressure (165 MPa). In subsequent trials, the mold temperature was reduced to 60°C and this eliminated blisters. A combination of mold temperature (60°C) and MLFM was used to prepare the balance of the bars. Piston pressure was maintained at 165 MPa and the melt injection speed was increased to 1.20 × 10-4 m3 s-1 (Table II(a)).These changes were effective in eliminating blisters. A high-quality X-ray radiograph of a bar produced from MC-2 is shown in Figure 9(b). Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
CONCLUSIONS This study has shown that MLFM—multiple live feed—process parameters can be optimized to develop AMCs 20 mm in thickness without defects. The results also show that the low-viscosity composite mix MC-1 develops flow lines in the bars. MC-2 has an acceptable viscosity for operating the MLFM device and parts were produced without flow lines, weld lines, and microvoids. For the high-viscosity mix MC-6, the MLFM device could not be activated due to rapid solidification of the melt in the die cavity. Blisters in molded bars were controlled by reducing the die cavity temperature; a high die temperature results in degradation of the low-temperature constituents in the binder. This study has demonstrated the potential of the MLFM process for producing lowweight, high-strength defect-free AMC parts by PIM. Potential applications for such parts are in the automotive and aerospace industries. REFERENCES 1. R.M. German and A. Bose, Injection Molding of Metals and Ceramics, 1997, Metal Powder Industries Federation, Princeton, N.J. 2. R.M. German and A. Bose, “Novel Processing Approaches to Intermetallic Matrix Composites”, Adv. Mat. and Manufacturing Process. 1988, vol. 3, no. 1, pp. 37–48. 3. D.E. Alman, N. S. Stoloff, A. Bose and R. M. German, “Structure and Properties of Aligned Short FibreReinforced Intermetallic Matrix Composites”, Journal of Materials Science, 1995, vol. 30, no. 20, pp. 5,251–5,258. 4. S.J. Steadman, “Injection Molded Composite Ceramics”, PhD Thesis, 1990, Brunel University of West London, UK. 5. S.J. Stedman, J.R.G. Evans, R.J. Brook and M.J. Hoffmann, “Anisotropic Sintering Shrinkage in Injection Molded Composite Ceramics”, J. Euro. Ceramic Society, 1993, vol. II, pp. 523–531. 6. H. Tuan and R.J. Brook, “Sintering of Hetrogenous
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CONTROL OF DEFECTS IN POWDER INJECTION MOLDED ALUMINUM MATRIX COMPOSITES
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Ceramic Compacts”, J. Mater. Sci., 1989, vol. 24, pp. 1,953–1,958. N.H. Loh, S.B. Tor and K.A. Khor, “Production of Metal Matrix Composite Parts by Powder Injection Molding”, Journal of Materials Processing Technology, 2001, vol. 108, no. 3, p. 398–407. I.E. Pinwill, F. Ahmad, P.S. Allan and M.J. Bevis, “Application of Shear Controlled Orientation Technology to Powder Injection Molding”, Powder Metallurgy, 1992, vol. 35, pp. 1–6. T. Zhang, J.R.G. Evans and M.J. Bevis, “Control of Orientation in Short Fiber -Reinforced Metal Matrix Composites”, Int. J. of Powder Metall., 1998. vol. 32, no. 4, pp. 331–339. F. Ahmad, “Injection Molded SiC-Reinforced PM Aluminum Matrix Composites”, Int. J. of Powder Metall., 2006, vol. 42, no. 3, pp. 67–73. T. Zhang and J.R.G. Evans, “The Solidification of Large Sections in Ceramic Injection Molding I: Conventional Molding”, J. Mat. Res., 1993, vol. 8, pp. 187–194. T. Zhang, M.J. Edirisinghe and J.R.G. Evans, “A Catalogue of the Ceramic Injection Molding Defects and Their Causes”, Ind. Ceramics, 1989, vol. 9, no. 2, pp. 72–82. P.S. Allan, M.J. Bevis, S.T. Hardwick and M. Murphy, “Moulding of Thick-Section Glass-Fibre Reinforced Thermoplastic Blocks Representing and Actuation System Support Structure”, Plastics and Rubber Processing and Applications, 1990, vol. 13, no. 1, pp. 15–27. P.S. Allan, M.J. Bevis, M.J. Edirisinghe, J.R.G. Evans and P.R. Hornsby, “Avoidance of Defects in Injection-Moulded Technical Ceramics”, J. Materials Science Letters, 1987, vol. 6, no. 2, pp. 165–175 I.E. Pinwill, M.J. Edirisinghe and M.J. Bevis, ”Development of Temperature-Heating Rate Diagrams for the Pyrolytic Removal of Binder used for Powder Injection Moulding”, J. Materials Science Letters, 1992, vol. 27, no. 16, pp. 4,381–4,388. A. Simchi, F. Petzoldt and H. Pohl, “On the Development of Direct Metal Laser Sintering for Rapid Tooling”, J. Materials Processing Technology, 2003, 141, pp. 319–328. T.B. Sercombe and G.B. Schaf fer, “On the Role of Magnesium and Nitrogen in the Infiltration of Aluminum by Aluminum for Rapid Prototyping Applications”, Acta Mater., 2004, vol. 52, no. 10, pp. 3,019–3,025. J.M. Marten and F. Castro, “Liquid Phase Sintering of P/M Aluminum Alloys: Effect of Processing Conditions”, J. Materials Process Technology, 2003, vol. 143–144, pp. 814–821. P.S. Allan and M.J. Bevis, "Multiple Live-Feed Injection Moulding," Plastics and Rubber Processing and Applications” , 1987, vol. 7, no. 1, pp. 3–10. M.J. Bevis and P.S. Allan, "Multiple Live-Feed Processing as a Route for Fibre Management in Composite Materials", Int. Conf. on New Materials & Their Applications, Institute of Physics, UK, 1990, pp. 13–23. F. Ahmad, “Orientation of Short Fiber in Powder Injection Molded Aluminum Matrix Composites”, Int. J. of Materials Processing Technology, 2005, vol. 169, no. 2, pp. 263–269, F. Ahmad, and M.J. Bevis, “A Study of Compounding Process for Metal Matrix Composites”, 5th International Symposium on Advanced Materials (ISAM), Kahuta
Research Laboratories, Rawalpindi, Pakistan, 1997, pp. 31–37. 23. F. Ahmad, “Rheology of Metal Composite Mixes for Powder Injection Molding”, Int. J. of Powder Metall., 2005, vol. 41, no. 4, pp. 43–49. 24. R.M. German and F. Ahmad, “Statistical Analysis of Fiber Fracture During Powder Injection Molding”, Powder Metallurgy, 2006, vol. 49, no. 44, pp. 307–313.
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RESEARCH & DEVELOPMENT
UNIVERSAL HARDNESS TEST TO CHARACTERIZE PM STEELS Gian F. Bocchini*, Barbara Rivolta** and Riccardo Gerosa**
INTRODUCTION According to Boyer,1 “There is probably no word in the English language for which so many definitions from so many sources have been offered as the term ‘hardness.’ Within the scientific community, hardness also represents different concepts: to a metallurgist, it represents resistance to penetration; to a lubrication engineer it means resistance to wear; whereas it denotes a measure of flow stress to a design engineer, resistance to scratching to a mineralogist, and resistance to cutting to a machinist. Although these actions appear to differ greatly in character, they are all related to the plastic flow stress of the material.” ASM2 defines hardness as, “Resistance of metals to plastic deformation, usually by indentation. However, the term may also refer to stiffness or temper or to resistance to scratching, abrasion or cutting. Indentation hardness may be measured by various hardness tests, such as Brinell, Rockwell and Vickers.” As is well known, the Vickers and Brinell tests require optical measurement of the indentation, while the Rockwell test requires the measurement of the indentation depth, after load removal, and may be carried out in a completely automated mode. The possibility of automatic testing is an advantage, but, unfortunately, the range of test loads is inadequate for measurements localized or focused on very small selected areas. This requirement may be satisfied by the Vickers hardness test, which has the advantage of a constant penetration angle, so that hardness results are essentially independent of the load. A comparison between the Rockwell and Vickers hardness tests identifies a new method, which simultaneously includes the advantages of automatic testing and numerical results which are not influenced by the load level. This optimum solution is a reality; since the late 1980s, it has been possible to carry out automated hardness tests by means of machines able to measure and record continuously the force and corresponding penetration depth. These two quantities are recorded during the entire test (loading and unloading). The physical property measured by the new method is termed universal hardness. In addition to automatic measurement of the hardness, the values of the force and the corresponding position of the indenter are useful in determining the elasto-plastic properties of materials, through suitable formulas. Analysis of the load vs. indenta-
Globalization enables powder metallurgy (PM) parts makers to choose powders from different sources. Raw materials of a specified composition produced by a given process should be equivalent. Differences in sintering behavior in industrial equipment have been investigated for PM steels obtained from four diffusionbonded powders with an atomized iron base and the same alloy content. Two levels of carbon and two sintering conditions were included. Results obtained from the application of a universal (instrumented) Vickers hardness test are presented which records simultaneously load and indentation depth, revealing the elasto-plastic parameters of the material. The comparison allows integration of the results obtained through conventional techniques, such as macrohardness, dimensional variation, transverse rupture strength, microstructures, microhardness distribution, or more advanced approaches, such as local nickel content, pore geometry, and fractal analysis. The method offers potential for powder producers to improve their products in relation to sintering practice.
*Powder Metallurgy Consultant, via Vespucci 48, 16035 Rapallo (GE), Italy; E-mail:
[email protected], **Assistant Professor, Politecnico di Milano, Polo Regionale di Lecco, via M. d’Oggiono 18a, 23900 Lecco, Italy; E-mail:
[email protected]
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tion depth curve also represents a powerful method for assessing the strength of surface layers deposited on metallic materials and parts. These studies led to the German standard DIN 50359, issued in 1997,3–5 which states: “With the so-called universal hardness test, the hardness is measured while the test force is still being applied.” Over the last twenty years, progress in force application, depth measurement, and data acquisition techniques have made it possible to develop this method to the point where it can finally be put into practice. One advantage of this method is that the indentation depth is not evaluated visually, but is measured automatically. Compared with other optical methods, the subjectivity of the observer is eliminated. UNIVERSAL (INSTRUMENTED) HARDNESS TESTING Test forces range from 2 N to 1,000 N for macrohardness testing and <2 N for microindentation hardness testing. It is interesting to note that the latter range is compatible with PM materials for mechanical components and self-lubricating applications. Experience has demonstrated that the maximum load required to exclude any influence of porosity is between 1 and 2 N. The universal hardness value (HU) is given by the ratio of the test force (F) to the area A(h), which is the (sloping) area of the indentation under the applied test force: F HU = —— [N/mm2] A(h)
α 4sin — 2 A(h) = ————— h2 = 26.43·h2 [mm2] α 2 cos — 2
( ) ( )
(1)
during the test is illustrated in Figure 1. The mechanical work produced during indentation (Wtotal) is only partially consumed as plastic deformation work (W plast ). The remainder is released as work of elastic recovery (Welast). From the definition of mechanical work, W = ∫ F dh, these two contributions can be represented by the two areas shown in Figure 2. Equation (3) allows for further characterization of the material. The total work spent during the period of load increase is Wtotal. From Figure 2, this is given by: Wtotal = Welast + Wplast
(3)
The elastic contribution is given by: Welast Welast ηHU = —————— ·100 = ——— ·100 [%] Wtotal Welast+Wplast
(4)
and the plastic contribution is given by: (2)
F [N] is the test force, h [mm] is the indentation depth while the force is being applied, and α is the vertex angle of the indenter. The DIN standard states that the test can be carried out at constant force or at constant indentation depth, and that it also requires a minimum level of surface preparation. The surface finish depends on test load. To ensure that surface roughness does not cause uncertainty in the measurement to exceed 10%, the indentation depth (h) needed to determine the universal hardness, shall be at least 20 times larger than the mean deviation of the surface profile (Ra). A typical plot of load vs. indentation depth recorded
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Figure 1. Typical load vs. indentation depth curve in the universal hardness test
Wplast Wplast ηplast = —————— ·100 =——— ·100 [%] Wtotal Welast+Wplast
(5)
Figure 2. Plastic and elastic contributions to work of indentation
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It follows that:
ηHU Wplast = Wtotal· 1– —— 100
(
)
(6)
According to DIN Standard 50359, the plastic hardness is given by the ratio of the test force to an area calculated by extrapolation, as shown in Figure 3: Fmax HUplast = ————— 26.43·h02
(7)
where h0 [mm] is the point of intersection of the tangent of the curve at maximum force (at removal of the test force) and the indentation depth axis (x-axis), while Fmax is the maximum force. Bocchini et al.6 approached the study of universal hardness testing by making tests on fully dense steels. The results were compared with “traditional” Vickers hardness tests on the same material. A strong correlation between the plastic hardness (HUplast), measured at 1 N load, and the Vickers microindentation hardness (HV 0.1) was observed. The authors successfully applied the test to PM steels, characterized by different chemical composition, different density, and different alloying method. The results confirmed that excellent correspondence existed between HV5 and HUplast (5 kg load) for all the PM steels examined. It is of interest to point out the formal analogy between the expression for plastic hardness and the common expression for Vickers hardness:
α sin —— 2 Fmax kg N =1.8544· ——— ——— or ——— (8) HV=2 Fmax ———— d2 d2 mm2 mm2
( )
[
] [
]
where d is the diagonal of the projected indenta-
Figure 3. Determination of plastic hardness—dashed line is tangent to the curve of decreasing test load
Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
tion area. Din Standard 50359 states that: “The modulus of elasticity (Young’s modulus) for the indentation (YHU) can be calculated from the slope of the tangent used to determine plastic hardness,” as shown in Figure 3. The indentation modulus is comparable with Young’s modulus for the material under test. 1 YHU= ——————————————— α ·h ·—— Δh h 4·tan — 2 0 ΔF max (1-νdia) ——————————— – ——— √π Edia
( )
(
)
1 = ———————————————— Δh (h )–7.813·10-7 5.586·h0· —— ΔF max
(9)
where h0 is the point of intersection of the tangent of the curve at maximum force and the indentation depth axis (x-axis) in mm, Δhmax/ΔF is the reciprocal slope of the tangent to the curve at maximum force in mm/N, νdia is the Poisson’s ratio for diamond (0.25), and Edia is the Young’s modulus for diamond (1.2 MN/mm2). The literature provides a theoretical rationale for equation (9) and defines the overall (or system) modulus as: 1–v2 1–vin2 E*= ——— + ——— E Ein
[
]
-1
1 —— dF = —— K√A dh
( )
(10)
where A is the true contact area at maximum load, and K is a constant, depending on the shape of the indenter. According to Doerner and Nix,7 for a pyramidshaped indenter, equation (10) can be modified to: ΔF √π E*= ——— —— 2√A* Δh
(11)
where A* is the projection on the test plane of the indentation surface corresponding to the maximum penetration depth hmax. By replacing the terms in (11), it is possible to again find the expression given by the standard. Several studies can be found in the technical literature investigating the method on different materials.8–23 According to DIN Standard 50359 for homogeneous materials (i.e., materials in which the amount of inhomogeneities at the surface is small compared with the indentation depth), the following equation applies (at least over some portions of the force–indentation curve): h = m·√F
(12)
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where m [mm·N-1/2] is the slope, which can be determined by linear regression from the experimental results. In this case, the hardness (termed modified hardness) is given by a modified equation: 1 HUs= ————— 26.43m2
(13)
The DIN standard cites a specific advantage of this method, namely, that uncertainties in the zero point determination and surface roughness may be disregarded. The effect of vibration on the test results obtained with larger test forces and indentation depths is also reduced significantly. However, for materials in which hardness values change with indentation depth, HUs values deviate from the corresponding HU value. The differences between HU and HUs values, at least in principle, provide quantitative information about hardness gradients within the subsurface layers. Bocchini et al.6 reported all the data obtained from their experimental investigation and the results show that, for all the PM steels investigated, equation (12) is satisfied, as it is for the fully dense steels. Also, the differences between HU and HUs values observed for PM materials are comparable with those observed for fully dense steels. For completeness, two other outcomes of the universal hardness test are cited: • By measuring the change in the indentation depth at a constant test force, it is possible to obtain a measure of the creep behavior of a material; • By measuring the change in the test force at a constant indentation depth, it is possible to obtain a measure of the relaxation rate of a material. EXPERIMENTAL TESTS The abundance and variety of information that can be acquired rapidly and easily from an automated hardness test motivated application of the new method to PM materials. The authors have already applied the test successfully to PM steels.6 This paper reports the results of the universal hardness test to monitor the response to sintering of four diffusion-bonded powders (atomized base) from different producers. These powders, at least in Europe, are considered to be nominally equivalent. Two levels of carbon and two sintering conditions were investigated. The nominal composition of the powders was: 1.75 w/o Ni, 1.5 w/o Cu, 0.5
80
Figure 4. Experimental apparatus for four-point bend tests
w/o Mo. Each of the raw materials was coded: #1, #2, #3, or #4. For each base grade, two mixes were prepared, by the powder supplier, with the addition of 0.75 w/o lubricant, and 0.3 w/o or 0.6 w/o graphite. Current PM production parts compacted and sintered to a nominal density of 6.7–6.8 g/cm3 were selected as test samples. The compacts, grouped and marked, were sintered as follows: • belt conveyor furnace under endogas atmosphere from methane at 1,125°C, for 25 min; • combined transfer furnace under 90 v/o N2/10 v/o H2 atmosphere, at 1,180°C, for 30 min. After sintering the samples were characterized in terms of microstructure and hardness.24 Universal hardness tests were performed on each material using a maximum force of 49 N. Important parameters were calculated by analyzing the force–indentation curves. For each set of materials and conditions, ten indentations were made on the surface of the specimens after polishing by standard metallographic procedures. To compare the results obtained from the indentation modulus calculation (YHU), four-point bend tests were carried out. The bend deformation of the specimens was measured by means of strain gauges glued to the surface of the beam subjected to tensile stress at the location of constant bending moment. Deformation was measured by using a Wheatstone Bridge. 25 The experimental apparatus is shown in Figure 4. From the experimental data, Young’s modulus wsa calculated and the results compared with those obtained from the universal hardness test. RESULTS Figures 5 and 6 show the results obtained in Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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calculating the universal hardness HU of the PM steels with 0.3 w/o and 0.6 w/o carbon (nominal values). The carbon contents analyzed on sintered parts are presented in Table I. The values of universal hardness were evaluated at the maximum indentation force immediately prior to unloading. No significant dif ferences were observed between the steels sintered at a given temperature, with the exception of the steel based on powder #2, which exhibited a higher hardness value, but was characterized by a high standard deviation compared with the other powders after sintering at 1,125°C and 1,180°C. This tendency was not as evident for the 0.6 w/o carbon steel, since the PM steels from different powders appear to show the same behavior. For sintering at 1,125°C it is noted that the steel based on powder #2 no longer exhibited a higher hardness. Steels based on powders #1, #2, and #3 gave the same value of universal hardness, but
TABLE I. SINTERED CARBON CONTENT w/o C (Nominal)
Material Code #1 #2 #3 #4 w/o C After Sintering
Sintering Temperature (°C)
0.3
0.32 0.29
0.30 0.30
0.32 0.31
0.32 0.30
1,125 1,180
0.6
0.59 0.59
0.55 0.59
0.55 0.59
0.56 0.58
1,125 1,180
with a small decrease for powder #4. Moreover, the steels showed a different response to sintering at 1,180°C, similar to powders #2, #3, and #4, which showed lower values of universal hardness. This behavior is attributed to differences in cooling rates after sintering in different industrial furnaces and under different atmospheres. Figure 7 and Figure 8 illustrate the calculated data for plastic universal hardness. Values of the
Figure 5. HU values (at 49 N) of 0.3 w/o carbon steel sintered at 1,125°C or 1,180°C
Figure 7. Plastic universal hardness of 0.3 w/o carbon steel sintered at 1,125°C or 1,180°C
Figure 6. HU values (at 49 N) of 0.6 w/o carbon steel sintered at 1,125°C or 1,180°C
Figure 8. Plastic universal hardness of 0.6 w/o carbon steel sintered at 1,125°C or 1,180°C
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Figure 11. Typical indentation curves and deformed surface after load removal (a) ηHU = 100%, (b) ηHU = 0%
Figure 9. Maximum indentation depth measured on 0.3 w/o carbon steel after s intering at 1,125°C or 1,180°C
Figure 12. ηHU values for 0.3 w/o carbon steel after sintering at 1,125°C or 1,180°C
Figure 10. Maximum indentation depth measured on 0.6 w/o carbon steel after sintering at 1,125°C or 1,180°C
plastic universal hardness confirm this tendency for the universal hardness. The same tests provide information about the maximum indentation depth, in terms of a “deformability index” of the material, Figure 9 and Figure 10. From an analysis of the force–indentation curves it is possible to calculate more sophisticated parameters such as the elastic contribution to the indentation work, defined by equation (4). If ηHU is equal to 100%, the unloading curve tends to run through the loading curve, giving rise to no residual deformation and to a residual indentation depth equal to zero (all elastic recovery), Figure 11(a). If ηHU is equal to 0%, there is no elastic recovery of the indentation and the typical shape of the curve is represented by Figure 11(b). In this case, the final indentation depth after load removal is equal to the maximum value obtained during the test. The results obtained for the PM steels are displayed in Figure 12 and 13.
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Figure 13. ηHU values for 0.6 w/o carbon steel after sintering at 1,125°C or 1,180°C
All the PM steels containing 0.3 w/o carbon and sintered at 1,180°C show a higher elastic recovery in comparison with the steels sintered at 1,125°C. The response of the 0.6 w/o carbon steels is different: the powders from the different producers show differences in behavior at the same sintering temperature and a different response at the higher sintering temperature. Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
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TABLE II.YOUNG’S MODULUS FROM FOUR-POINT BEND TEST (E) AND UNIVERSAL HARDNESS TEST (YHU) Property
0.3 w/o C – 1,125°C
0.3 w/o C – 1,180 °C
0.6 w/o C– 1,125°C
0.6 w/o C– 1,180°C
E [GPa]
Average Std. dev.
105 5
102 7
105 4
105 3
YHU [GPa]
Average Std. dev.
122 6
116 3
112 9
118 10
After sintering at 1,125°C, the steel based on powder #1 shows a higher elastic recovery in comparison with those based on powders #2, #3, and #4. This behavior can be explained by the results of the microstructural analysis. 24 The steel from powder #1 sintered at 1,125°C is characterized by a bainitic microstructure, with small traces of fine pearlite and retained austenite, transforming into acicular structures. Higher amounts of retained austenite have been observed in the steels based on powders #2, #3, and #4, thus explaining the observed higher plastic work ratio. Also, the response to sintering at 1,180°C is different for the steel from powder #1, since it exhibits a large decrease in elastic recovery. As reported previously,24 this can be explained by the fact that the higher sintering temperature increases the extent of dif fusion of the alloying elements. The microstructure is more homogenous and initiation of the austenite transformation is shifted to lower temperatures. Finally, information about Young’s modulus of the PM steels was obtained both from the universal hardness tests and from the four-point bend tests. The results are reported in Table II. Good agreement exists between the results obtained from the two different techniques. CONCLUDING REMARKS Results obtained from the application of the universal hardness test on PM steels derived from nominally equivalent diffusion-bonded powders, at essentially the same density, sintered in different industrial furnaces are reported. On the basis of these results, the following conclusions can be made: • The universal hardness test is capable of characterizing sintered steels in the elastic and plastic fields; • The parameters HU and HUplast exhibit differences in behavior between steels from nominally equivalent powders; the differences become important for sintered steels containVolume 44, Issue 3, 2008 International Journal of Powder Metallurgy
ing 0.3 w/o carbon; • Differences between the 0.6 w/o carbon steels, not so evident in terms of hardness, are clearly seen in terms of the ηHU parameter, which is representative of the elastic ratio of the indentation work; • A complete analysis of the indentation curve reveals differences in the response of each base powder; • From the universal hardness test the indentation elastic modulus can be evaluated. Values are in good agreement with Young’s modulus obtained from the instrumented four-point bend test; • The universal hardness test is a reliable nondestructive method for making a comparative analysis of different powders. These analyses are particularly useful if standard tensile specimens cannot be produced "in-house." ACKNOWLEDGEMENTS The authors thank Stame (Arosio, CO, Italy) for preparing the PM steels used in the present investigation. REFERENCES 1. Hardness Testing, edited by H.E. Boyer, ASM International, Metals Park, OH, 1987. 2. Metals Handbook, Desk Edition, ASM International, Metals Park, OH, 1985. 3. DIN 50359-1, Universal Hardness Testing of Metallic Materials—Test Method, 1997. 4. DIN 50359-2, Universal Hardness Testing of Metallic Materials—Verification of Testing Machines, 1997. 5. DIN 50359-3, Universal Hardness Testing of Metallic Materials—Calibration of Reference Blocks, 1997. 6. G.F. Bocchini, B. Rivolta and G. Silva, “An Application of the Universal Hardness Test to P/M Materials”, Advances in Powder Metallurgy & Particulate Materials— 2002, compiled by V. Arnhold, C-L Chu, W.F. Jandeska Jr. and H.I. Sanderow, Metal Powder Industries Federation, Princeton, NJ, 2002, part 11, pp. 99–109. 7. M.F. Doerner and W.D. Nix, “A Method for Interpreting the Data from Depth-Sensing Indentation Instruments”, J. Mater. Res., 1986, vol. 1, no. 4, p. 601. 8. A.E. Giannakopoulos, P.L. Larsson and R. Vestergaard,
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“Analysis of Vickers Indentation”, Int. J. Solids Struct., 1994, vol. 31, no. 19, pp. 2,679–2,708. P.L. Larsson, A.E. Giannakopoulos, E. Soderlund, D.J. Rowcliffe and R. Vestergaard, “Analysis of Berkovich Indentation”, Int. J. Solids Struct., 1996, vol. 33, no. 2, p. 221. A.E. Giannakopoulos and P.L. Larsson, “Analysis of Pyramid Indentation of Pressure-Sensitive Hard Metals and Ceramics”, Mech. Mater., 1997, vol. 25, no. 1, pp. 1–35. B.J. Briscoe, K.S. Sebastian and M.J. Adams, “Effect of Indenter Geometry on the Elastic Response to Indentation”, J. of Physics D: Applied Physics, 1994, vol. 27, no. 6, pp. 1,156–1,162. Y. Cheng and C.M. Cheng, “What is Indentation Hardness”, Surface and Coatings Technology, 2000, vol. 133–134, pp. 417–424. T.A. Venkatesh, K.J. Van Vliet, A.E. Giannakopoulos and S. Suresh, “Determination of Elasto-Plastic Properties by Instrumented Sharp Indentation: Guidelines for Property Extraction”, Scripta Mater., 2000, vol. 42, no. 9, pp. 833–839. C.M. Cheng and Y.T. Cheng, “Scaling Relationships in Conical Indentation of Elastic-Perfectly Plastic Solids”, Int. J. of Solids and Structures, 1999, vol. 36, no. 8, pp. 1,231–1,243. C.M. Cheng and Y.T. Cheng, “On the Initial Unloading Slope in Indentation of Elastic-Plastic Solids by an Indenter with an Axisymmetric Smooth Profile”, Applied Physics Letters, 1997, vol. 71, no. 18, p. 2,623. W.C. Oliver and G.M. Pharr, “An Improved Technique for Determining Hardness and Elastic Modulus Using Load and Displacement Sensing Indentation Experiments”, J. Mater. Res., 1992, vol. 7, no. 6, pp. 1,564–1,580. A.E. Giannakopoulos and S. Suresh, “Determination of Elastoplastic Properties by Instrumented Sharp Indentation”, Scripta Mater., 1999, vol. 40, no. 10, pp. 1,191–1,198. F.M. Haggag, R.K. Nanstad and D.N. Braski, “Structural Integrity Evaluation Based on an Innovative Field Indentation Microprobe”, Innovative Approaches to Irradiation Damage and Fracture Analysis, edited by D.L.
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Marriott, T.R. Mager and W.H. Bamford, American Society of Mechanical Engineers, New York, NY, 1989, vol. 170, pp. 101–107. F.M. Haggag and R.K. Nanstad, “Estimating Fracture Toughness Using Tension or Ball Indentation Tests and a Modified Critical Strain Model,” ibid. reference no. 18, pp. 41–46. F.M. Haggag, R.K. Nanstad, J.T. Hutton, D.L. Thomas and R.L. Swain, “Use of Automated Ball Indentation to Measure Flow Properties and Estimate Fracture Toughness in Metallic Materials”, Applications of Automation Technology to Fatigue and Fracture Testing, American Society for Testing and Materials, Conshohocken, PA, 1992. F.M. Haggag, “In-Situ Measurements of Mechanical Properties Using Novel Automated Ball Indentation System”, Standard Technical Publication 1204, American Society for Testing and Materials, Conshohocken, PA, 1993. F.M. Haggag, J.A. Wang, M.A. Sokolov and K.L. Murty, “Use of Portable In-Situ Stress-Strain Mucroprobe System to Measure Stress-Strain Behavior and Damage in Metallic Materials and Structures”, Nontraditional Methods of Sensing Stress, Strain, and Damage in Materials and Structures, American Society for Testing and Materials, Special Technical Publication 1318, Conshohocken, PA, 1997. T. Sang Byun, J.W. Kim and J.H. Hong, “A Theoretical Model for Determination of Fracture Toughness of Reactor Pressure Vessel Steels in the Transition Region from Automated Ball Indentation Test”, J. Nuclear Materials, 1998, vol. 252, pp. 187–194. G.F. Bocchini, M.G. Ienco, M.R. Pinasco, A. Baggioli, R. Gerosa and B. Rivolta, “Nominally Equivalent Powders for P/M Steels: Analysis of Response to Sintering and Differences at Various C Content”, Materials Science Forum, 2006, vol. 534–536, pp. 701–704. G.F. Bocchini, B. Rivolta and G. Silva, “Properties of Steam-Treated P/M Materials Determined by Universal Hardness Testing”, Euro PM 2004, edited by H. Danninger and R. Ratzi, European Powder Metallurgy Association, Shrewsbury, UK, 2004, vol. 2, pp. 443–449. ijpm
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MEETINGS AND CONFERENCES
2008 REACH WORKSHOP May 29–30 Brussels, Belgium www.epma.com 2008 WORLD CONGRESS ON POWDER METALLURGY & PARTICULATE MATERIALS June 8–12 Washington, DC MPIF* 2008 INTERNATIONAL CONFERENCE ON TUNGSTEN, REFRACTORY & HARDMATERIALS VII June 8–12 Washington, DC MPIF* 19TH AEROMAT CONFERENCE & EXPOSITION June 23–26 Austin, TX www.asminternational.org/ aeromat ICCE-16 16TH ANNUAL INTERNATIONAL CONFERENCE ON COMPOSITES/ NANO ENGINEERING July 20–26 Kunming, China www.uno.edu/~engr/composite BASIC PM SHORT COURSE July 21–23 State College, PA MPIF* PM SINTERING SEMINAR September 23–24 Cleveland, OH MPIF* 5TH INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS AND PROCESSING September 3–6 Harbin, China icamp.hit.edu.cn
SUPERALLOYS 2008 September 14–18 Champion, PA www.tms.org/Meetings/ specialty/superalloys2008/ home.html INTERNATIONAL CONFERENCE ON ALUMINUM ALLOYS September 22–26 Aachen, Germany www.dgm.de EURO PM2008 September 29–October 1 Mannheim, Germany www.epma.com/pm2008 MATERIALS SCIENCE & TECHNOLOGY 2008 CONFERENCE & EXHIBITION October 5–9 Pittsburgh, PA www.matscitech.org/2008/ home.html 5TH INTERNATIONAL POWDER METALLURGY CONFERENCE October 8–12 Ankara, Turkey www.turkishpm.org/5pm2008 2008 CHINA (SHANGHAI) INTERNATIONAL POWDER METALLURGY EXHIBITION & CONGRESS October 25–26 Shanghai, China www.china-pmexpo.com/en SINTERING 2008 November 16–20 La Jolla, CA www.ceramics.org/sintering 2008 PMP III THIRD INTERNATIONAL CONFERENCE— PROCESSING MATERIALS FOR PROPERTIES December 7–10 Bangkok, Thailand www.tms.org/meetings/ specialty/pmp08
*Metal Powder Industries Federation 105 College Road East, Princeton, New Jersey 08540-6692 USA (609) 452-7700 Fax (609) 987-8523 Visit www.mpif.org for updates and registration. Dates and locations may change Volume 44, Issue 3, 2008 International Journal of Powder Metallurgy
2009 PM-09 5TH INTERNATIONAL CONFERENCE & EXHIBITION February 16–18 Goa, India www.pmai.in 17TH PLANSEE SEMINAR ON HIGH-PERFORMANCE PM MATERIALS May 25–29 Reutte, Austria www.plansee.com TOOL 09— TOOL STEELS June 2–4 Aachen, Germany www.tool09.rwth-aachen.de POWDERMET2009: MPIF/APMI INTERNATIONAL CONFERENCE ON POWDER METALLURGY & PARTICULATE MATERIALS June 28–July 1 Las Vegas, NV MPIF* THERMEC 2009: SIXTH INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS AND PROCESSES August 25–29 Berlin, Germany SDMA 2009/ICSF VII— 4TH INTERNATIONAL CONFERENCE ON SPRAY DEPOSITION AND MELT ATOMIZATION/7TH INTERNATIONAL CONFERENCE ON SPRAY FORMING September 7–9 Bremen, Germany www.sdma-conference.de
2010 POWDERMET2010: MPIF/APMI INTERNATIONAL CONFERENCE ON POWDER METALLURGY & PARTICULATE MATERIALS June 27–30 Hollywood (Ft. Lauderdale), FL MPIF*
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MAYBE NOW’S THE TIME TO JOIN APMI INTERNATIONAL… Here’s just a sample of the benefits you receive as an APMI member International Journal of Powder Metallurgy
Publications Receive discounts on PM publications covering every aspect of powder metallurgy processing and production.
Members receive both the print and electronic versions of the bi-monthly International Journal of Powder Metallurgy—the world’s leading and most authoritative journal covering scientific, technical, business and marketing information on the PM and advanced particulate industries. In each issue you will expert reports on: • • • • • • •
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Visit our Web sites: apmiinternational.org or mpif.org
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ADVERTISERS’ INDEX
ADVERTISER
FAX
WEB SITE
PAGE
ABBOTT FURNACE COMPANY________________________(814) 781-7334 _________www.abbottfurnace.com ___________________________26 ACE IRON & METAL CO. INC.______________________(269) 342-0185 ______________________________________________________6 ACUPOWDER INTERNATIONAL, LLC ________________(908) 851-4597 ________www.acupowder.com ___________________________17 ADVANCED METALWORKING______________________(317) 843-9359 ________www.advancedmetalworking.com _________________56 AMERICAN CHEMET _____________________________(847) 948-0811 ________www.chemet.com ______________________________47 AMETEK SPECIALTY METAL PRODUCTS _____________(724) 225-6622 ________www.ametekmetals.com ________________________11 ARBURG GmbH + Co KG _________________________(860) 667-6522 ________www.arburg.com _______________________________7 ASBURY CARBONS ________________________________(908) 537-2908 _________www.asbury.com _________________________________15 B HLER UDDEHOLM ____________________________(603) 883-3101 ________www.bucorp.com ______________________________29 BRONSON & BRATTON INC. ______________________(630) 570-4866
[email protected] _____________________76 CARPENTER POWDER PRODUCTS _________________(412) 257-5154 ________www.carpenterpowder.com ______________________40 CLEVELAND VIBRATOR __________________________(216) 241-3480 ________www.clevelandvibrator.com______________________22 CM FURNACES, INC. ____________________________(973) 338-1625 ________www.cmfurnaces.com __________________________10 CREMER ______________________________________+49 2421 63735 _______www.cremer-furnace.com ________________________8 ECKA GRANULES _______________________________(502) 253-4563 ________www.ecka-granules.com ________________________20 ELMCO ENGINEERING, INC._______________________(317) 788-0220 ________www.elmco-press.com__________________________68 ELNIK SYSTEMS ________________________________(973) 239-6066 ________www.elnik.com ________________________________14 HC STARCK____________________________________(617) 630-5919 ________www.hcstarck.com _____________________________12 HENKEL TECHNOLOGIES _________________________(315) 637-3086 ________www.henkel.com ______________________________36 HOEGANAES CORPORATION ______________________(856) 786-2574 ________www.hoeganaes.com ___________INSIDE FRONT COVER INCO SPECIAL PRODUCTS ________________________(201) 848-1022 ________www.incosp.com _______________________________4 KITTYHAWK PRODUCTS ____________________________(714) 895-5024 _________www.kittyhawkinc.com ____________________________67 KOBELCO _____________________________________(812) 522-5191 ________www.kobelcometal.com _________________________33 NIRO _________________________________________(410) 997-5021 ________www.niroinc.com ______________________________24 NORILSK NICKEL _______________________________(+ 7 495) 785 58 08 ____www.norilsknickel.com _________________________18 NORTH AMERICAN H GAN S INC. _________________(814) 479-2003 ________www.nah.com __________________________________3 OSTERWALDER ________________________________(513) 936 9006 ________www.osterwalder.com __________________________45 QMP _________________________________________(734) 953-0082 ________www.qmp-powders.com ________________BACK COVER QUAL-FAB, INC. ________________________________(440) 327-5599 ________www.qual-fab.net ______________________________30 SCM METAL PRODUCTS, INC. _____________________(919) 544-7996 ________www.scmmetals.com ____________INSIDE BACK COVER TIMCAL _______________________________________+41 91 873 2009 _______www.timcal.com_______________________________38 UNION PROCESS _______________________________(330) 929-3034 ________www.unionprocess.com _________________________43
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