International Journal of Powder Metallurgy Volume 43 Issue 6

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EDITORIAL REVIEW COMMITTEE P.W. Taubenblat, Chairman I.E. Anderson, FAPMI T. Ando S.G. Caldwell S.C. Deevi J.J. Dunkley W.B. Eisen Z. Fang B.L. Ferguson W. Frazier K. Kulkarni, FAPMI K.S. Kumar T.F. Murphy P.D. Nurthen J.H. Perepezko P.K. Samal H.I. Sanderow D.W. Smith, FAPMI J.E. Smugeresky 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 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 7 9 11

43/6 November/December 2007

Editor's Note Newsmaker Alexander Litvintsev PM Industry News in Review PMT Spotlight On … Maryann Wright PM Metallography Competition Research & Development, Product/Process Control and Artistic Categories

25 Outstanding Poster Awards Y.I. Seo, D.H. Shin, K.H. Min, Y.D. Yoon, S-Y Chang, K.H. Lee, and Y.D. Kim; C. McClimon, J.J. Williams and N. Chawla 27 Consultants’ Corner J.T. Strauss

35 Axel Madsen/CPMT Scholar Reports P. Lapointe, C. McClimon, D. Sampson and M. Sexton

ENGINEERING & TECHNOLOGY 39 Lubricants for High-Density Compaction at Moderate Temperatures L. Azzi, Y. Thomas and S. St-Laurent RESEARCH & DEVELOPMENT 47 R&D in Support of Powder Injection Molding: Status and Projections R.M. German 59 Sintering Response & Microstructural Evolution of an Al-Cu-Mg-Si Premix J.M. Martin and F. Castro 71 72 75 77 79 80

DEPARTMENTS Meetings and Conferences APMI Membership Application Instructions for Authors Table of Contents: Volume 43, Numbers 1–6, 2007 PM Bookshelf Advertisers’ Index Cover: Metallography Competition Winner. Photo courtesy: Bruce Lindsley, Hoeganaes Corporation, Cinnaminson, New Jersey

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 © 2007 by APMI International. Subscription rates to non-members; USA, Canada and Mexico: $90.00 individuals, $210.00 institutions; overseas: additional $35.00 postage; single issues $45.00. 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

D

iversity characterizes the content of this concluding issue of the Journal for 2007. In-depth technical articles focus on new lubricants for achieving high density via compaction at moderate temperatures; the status and future of the powder injection molding industry, based on supporting R&D; and microstructural evolution of an aluminum alloy premix during sintering. Joe Strauss is back in the “Consultants’ Corner,” and addresses the vexing problem of variability in the flow of inert-gas-atomized powders. He also discusses heat-transfer mechanisms in sintering as a function of furnace type, and expresses a poignant viewpoint on nanomaterials. I encourage you to read the reports prepared by the four 2007 CPMT/Axel Madsen Conference Grant recipients, based on their attendance at PowderMet2007. These are frank and incisive, and demonstrate the value of the program, both to students and the PM industry. Winning entries in the APMI 2007 PM Metallography Competition are recognized (Research & Development, Product/Process Control, and Artistic categories). In the first two categories, the content provides compelling examples of problem solving in PM via metallography. The front cover, titled “Feathers,” is illustrative of the artistic/aesthetic attributes of PM materials. Also recognized are the two Outstanding Posters from PowderMet2007.

Alan Lawley Editor-in-Chief

I always look forward to reading the September issue of R&D magazine since it includes the Annual R&D 100 Awards, recognizing the world’s best innovations from academe, government, and industry. Awards were given in 19 categories, including “Life Science/Materials” and “Materials & Metals.” Of the 12 awards in these two categories, three caught my eye: A new method (The Armstrong Process) for producing titanium powder on a continuous basis, with significant cost reduction (International Titanium Powder, Inc., www.itponline.com) A glass-forming overlay steel welding wire that does not require a metal binder phase, with superior properties and a price advantage over carbide wire in shielded and open arc applications (The NanoSteel Co. Inc., www.nanosteelco.com). Nickel aluminide intermetallic furnace rolls exhibiting superior yield strength, creep-rupture strength, and oxidation resistance compared with conventional austenitic stainless steel hot rolls (Duraloy Technologies Inc., www.duraloy.com). It is encouraging to note that the national laboratories continue to play an important role in the development of these new innovative processes and materials, in cooperation with industry—reflecting a wise allocation of tax dollars. Rewind to the evening of Tuesday, May 15, 2007. On that occasion, PowderMet2007 registrants participating in the conference social event attended a seemingly innocuous baseball game at Coors Field in Denver between the Colorado Rockies and the Arizona Diamondbacks. Who would have predicted that these two teams would battle for the National League Championship? I have a hunch that the Rockies season turned around when our very own Jean Lynn, enjoying a rare moment of stardom, caught a vicious foul ball!

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Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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Photo Ronnie Nilsson

You buy more than metal powder – you buy knowledge!

NAH 2004/04

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RHAPSODY, Copenhagen

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Metal powders open up new possibilities for creative technical solutions. Powder components require little or no subsequent machining, achieve nearly 100% material utilization, and deliver numerous performance benefits – including the lowest total unit cost for the manufacturer. These are just some of the reasons why over 40 million powder components are produced every single day. Actually, you find more and more of them in cars, computers, household machines and electrical tools. Have the advantage on your side, contact North American Höganäs, Inc. today.

North American Höganäs Inc., 111 Höganäs Way, Hollsopple, PA 15935-6416, USA, Phone +1 8144793500, Fax +1 8144792003, www.nah.com

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NEWSMAKER

ALEXANDER LITVINTSEV By Peter K. Johnson* Alexander Ivanovich Litvintsev, general director of Alspors Technology Ltd., Moscow, known for his work on aluminum powder metallurgy (PM), grew up in a scientific atmosphere. Born in Vladivostok, in the Far East region of Russia, he spent his early years in Aleksandrovsk-Sakhalinskiy, a small city on Sakhalin Island in the Sea of Japan. His father, a chemical engineer, managed the municipal chemistry laboratory there. In 1947, at the age of 18, he left home to attend the Moscow Railway Institute on a scholarship with lodging in a student hostel. “My main goal was to become a scientist,” he says. “I loved physics and chemistry. My father and mother wanted me to study in Moscow.” Having completed three years at the Railway Institute, Litvintsev hoped for a transfer to the Moscow Institute of Steel and Alloys to study at the new physical chemistry facility. However, rigid government regulations made this a difficult move. He was accepted initially for the 3rd course of the technological faculty. During the first semester in 1950 he completed all his examinations and was admitted to the 3rd course of the physical chemistry faculty. This resulted in the loss of his scholarship and residency in a student hostel. “My parents helped me to pay my living expenses for food and a rented room,” he says. The main condition of his move to the Moscow Institute of Steel and Alloys was achieving a first-class category in skiing. His athletic skills finally won over the institute’s director when he achieved a Master of Sport (first-class category) in skiing in 1949. He graduated from the institute with honors in 1954, receiving the equivalent of an MS in the physics of metals. Postgraduate studies on the Xray diffraction and electron microscopy of metals

followed. His interest in PM developed under the guidance of Professor Y. S. Umansky. Litvintsev received a PhD in 1958, concentrating on hightemperature tungsten carbide and titanium carbide. The title of his thesis was, “The Study of a Debye Characteristic Temperature for TiC-Based Carbides with Refractory Metals, Cr, Mo, and W.” After completing his education, he joined the light alloys plant in Kuntsevo, near Moscow, as head of the Xray laboratory. The plant was the first in Russia, he claims, that began producing hightemperature SAP (sintered aluminum powder) material.** “In 1958 I developed a method of mass spectrometric analysis of the kinetics of degassing aluminum powders during heating up to 600°C (1,112°F) in a vacuum and in argon,” he says. “Subsequently I developed a theory for aluminum powder degassing and an experimental process for degassing and producing semi-finished SAP products.” In 1961 he transferred to a branch of the AllUnion Institute of Aviation Materials at the Kuibyshev metallurgical plant. Using his degassing process, he designed a new technology for degassing cold-compacted aluminum powders in reusable cans in inert-gas flow. These results led to the commercial production of hot-extruded semi-finished products via the direct extrusion of aluminum PM alloys. During this time his interest in PM blossomed. He specialized in developing new PM aluminum materials such as high-strength, high-silicon alloys, metal matrix composites (MMC), and production processes. He recognizes the scientific guidance of academician I.N. Fridlaynder in this work. “Using X-ray methods I studied the processes of aluminum powder oxida-

*Managing editor and consultant ijpm **SAP, a fine dispersion of aluminum oxide in an aluminum matrix, was developed by researchers in Switzerland during the 1940s.

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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NEWSMAKER: ALEXANDER LITVINTSEV

tion and examined the phase composition of oxide films of various aluminum base melts,” he says. Litvintsev’s next career step was joining the Kuibyshev Polytechnic Institute in 1970 as assistant professor in the general physics department where he taught physics and materials science. He stayed there two years until returning to Moscow as deputy head of the aluminum powder laboratory and head of the aluminum powder section of the All-Union Institute of Light Alloys (VILS). “I concentrated on the development of technological processes for manufacturing semi-finished products from SAP alloys,” he says. “We used VILS pilot plant equipment: horizontal hydraulic presses and hydraulic cold compacting.” His work opened the way to make SAP bars and shapes for nuclear applications as well as sheet, strip, and bar for the aviation industry. “I paid special attention to developing a process for producing thinwalled SAP tubing including capillary tubes. I also developed a magnetic separation process for aluminum powders at one of the Ural powder shops.” His magnetic separation method led to the Russian standard for aluminum powders (1009676). Some additional accomplishments while working for VILS included the development of various aluminum alloys with zinc, copper, and magnesium, and an aluminum–silicon system for extruding semi-finished products and forged pistons for a tank engine. In 1991 he left VILS because of a management disagreement and formed his own company, Alspors Technology Ltd., to manufacture aluminum PM products. He collaborated with the joint stock company Nadvoitsky Aluminum Smelter in Korelia to make PM aluminum oil-pump bearings and a diesel engine camshaft support.

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His company produced 600,000 parts in 1994. “This was the first large-scale production of aluminum PM parts in Russia,” he notes. Leveraging his experience in manufacturing aluminum PM products, he developed a new process for making hot-extruded flat strip for the subsequent rolling of foamable precursors. He received a Russian patent (RU 2121904) for “A Method for Production of Porous Semiproducts from Aluminum Alloy Powder” in 1998. The method was based on the direct extrusion of an aluminum powder mixture with TiH2, a foaming agent. In this process he combined hot compaction and hot extrusion of the mixture of aluminum powder with TiH2, to make foamable precursors such as sheet, plate, strip, and rod. He received another patent (RU 2200647) in 2001 and a U.S. Patent Application in 2002 for producing foamable precursors via direct powder rolling. This patent opened the way for designing a continuous line for producing precursors via direct powder rolling with clad aluminum, titanium, and stainless steel, and without cladding. Several companies in the U.S. and Europe are interested in his foamed aluminum process. An APMI member for more than 10 years, he has 37 inventions and patents and has authored about 80 scientific papers, as well as one monograph, “Physical and Chemical Background of the Manufacture of Semi-Finished SAP Material.” Litvintsev has received numerous awards and medals for his research and commercial production processes. At the age of 78 he is still not only a creative engineer but an avid sportsman as well, walking 5 to 10 km daily at a steady pace of 6 km/h. ijpm

Volume 43, Issue 6, 2007 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.”

Miba Sells PM Plant Miba AG, Laakirchen, Austria, has sold its PM parts subsidiary in Barcelona, Spain, Miba Sinter S.A., to Allegra Capital GmbH, Munich, Germany. The purchase price was not disclosed. Market Share Blues Automotive News editors speculated on the further erosion of the Detroit 3’s U.S. market share to well below 50 percent. In July the market share of GM, Ford, and Chrysler slipped to 48.1 percent. PSM Industries Acquires Tungsten Carbide Firm PSM Industries, Inc., Los Angeles, Calif., has purchased Yillik Precision Industries, Inc. (YPI), Ontario, Calif., its fifth acquisition since 2000. YPI makes tungsten carbide PM products such as bushings, bearings, rollers, sizing dies, seal rings, and tooling guides. Chinese Company Buys Metal Flake Technology Nonfermet, Shenzhen, China, will install equipment developed and marketed by Zoz GmbH, Wenden, Germany, to produce nanosize ductile metal flakes in high volumes. Production is expected to begin by the end of 2007.

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

Domfer Explores Options Domfer Metal Powders Inc., LaSalle, Québec, filed a Notice of Intention with the Office of the Superintendent of Bankruptcy Canada, on August 14. The legal notice, similar to a Chapter 11 filing in the U.S., allows the company to explore various proposals with its creditors. PM Parts Maker Opens Office in Japan Chicago Powdered Metal Products Co., Schiller Park, Ill., has opened an engineering and sales service office in Nagoya, Japan. The office will mainly service North American OEM transplant companies, such as Toyota and Honda, in developing new PM parts applications. Spanish PM Parts Maker Expands Ames S.A., Barcelona, Spain, has opened its fifth powder metallurgy (PM) parts plant in the Aragón region of Spain. The new facility began production in June and is currently producing almost three million parts monthly. Tungsten Company Gains North American Tungsten Corporation Ltd., Vancouver, British Columbia, reported rising sales and earnings for the fiscal third quarter. Production at its Cantung mine increased to 80,357 metric ton units.

Nanofiber Market Surge The international market for nanofibers is forecast to exceed $800 million by 2017, reports BCC Research, Wellesley, Mass. The most important applications of nanofibers are mechanical/ chemical, energy, and electronics. PM Growing in Japan The Japan Powder Metallurgy Association, Tokyo, reports that automotive applications accounted for 92 percent of 2006 PM parts production in Japan. Production increased 4.2 percent to 116,925 short tons, while production of PM bearings declined slightly to 8,776 short tons. Sumitomo Electric Buys Cloyes Europe In a surprise move, Sumitomo Electric Industries, Ltd., and its wholly owned subsidiary Sumitomo Electric Sintered Alloys, Ltd., based in Japan, will acquire Cloyes Europe GmbH. Located in Zittau, Germany, the automotive PM parts operation is owned by Cloyes Gear & Products, Inc., Fort Smith, Ark., and its minority partner, Sumitomo Corporation Group. German Furnace Builder Opens New Business Sarnes ingenieure OHG, Ostfildern, Germany, has stablished SIT Sintertechnik GmbH, in Thale, eastern ijpm

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PM INDUSTRY NEWS IN REVIEW

Germany, to develop sintering technologies. The new company, a partner with PulverMetallurgisches Kompetenz-Centrum, a think tank for PM companies, has sintering and heat-treating capabilities for PM aluminum, PM steel, and metal injection molding. Nanomaterial Earns R&D Award NanoSteel Company, Providence, R.I., has received its third R&D 100 Award from R&D magazine for developing Hardmetal Alternative Technology: Super Hard Steel 9192 Weld Wire. The patented material has a very fine sub-micron microstructure that provides exceptional wear resistance, the company reports. Compacting Press Maker Moves SMS Meer Service Inc., owned by SMS Meer GmbH, Mönchengladbach, Germany, has moved its Pittsburgh office to Cranberry Township, Pa. The company’s broad line of steel products and services includes hydraulic compacting presses. PM Parts Maker Registers Sales Increase Miba AG, Laarkirchen, Austria, reported a four percent sales increase to 196.3 million euros (about $278 million) for the first half of its fiscal year. The company’s Sinter Group (PM parts) generated the largest share of sales at 44.8 percent or 87.9 million euros (about $125 million).

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Industry Leaders Meet PM industry leaders are gathered in Scottsdale, Ariz., for the Metal Powder Industries Federation’s (MPIF) Fall Management Conference and 63rd Annual Meeting. In his address to the delegates, MPIF President Ed Daver discussed the need to grow the global PM marketplace. PM Conference in India The Powder Metallurgy Association of India will sponsor the PM08 International Conference & Exhibition in Chennai, February 20–21, 2008. The technical program committee invites abstracts for oral and poster presentations which must be received by November 15, 2007. New MPIF Officers Mark C. Paullin, president and CEO of Capstan, Torrance, Calif., officially began serving a two-year term as president of the Metal Powder Industries Federation at the close of MPIF’s 63rd Annual Meeting in Scottsdale, Ariz. William A. Heath, PMT, vice president– marketing & business development, Metal Powder Products Corp., Westfield, Ind., began a two-year term as president of the Powder Metallurgy Parts Association. PM Design Competition Opens MPIF has opened the 2008 International PM Design Excellence Awards Competition, which recognizes outstanding achievements in the commercial production of powder metallurgy components. Entries must be received by January 31, 2008.

Hoeganaes Expands Annealing Capacity at Romanian Plant Hoeganaes Corporation, Cinnaminson, N.J., will install a second continuous annealing furnace at its Buz˘au, Romania, iron powder atomization plant. Scheduled to be operating in the second quarter of 2008, the furnace expansion follows the recent installation of a 20-ton blending unit. United States Bronze Powders Opens Distribution Center United States Bronze Powders, Inc., Flemington, N.J., has opened a distribution warehouse for the western Pennsylvania PM market at Jet Metals, Inc., in St. Marys. Jet Metals will stock all powder grades previously held at another location. MIM Business Growing Worldwide The Metal Injection Molding Association estimates that the international metal injection molding (MIM) parts market surged more than 25 percent in 2006 to about $550 million. MIM markets in Europe and Asia experienced the most growth. Arburg Opens Midwest Technology Center Arburg GmbH + Co KG, Lossburg, Germany, has opened a new technology center in Elgin, Ill., about 30 minutes from O’Hare International Airport. The company reports making a significant investment to serve its growing customer base in the Midwest. ijpm

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SPOTLIGHT ON ...

MARYANN WRIGHT Education: Siena College, BS Chemistry, 1979 Rensselaer Polytechnic Institute, MS Materials Engineering, 1982 Why did you study powder metallurgy/particulate materials? My introduction to powder metallurgy (PM) occurred in the first job after graduating from college. I was working as a chemist at Homogeneous Metals (HMI), a nickel-base superalloy powder producer. Subsequently, I took an introductory course in metallurgy at a local community college, and found the subject matter of sufficient interest that I applied to RPI’s master’s degree program in Materials Engineering, and was accepted. After obtaining my graduate degree from RPI, my career path tur ned to Materials Engineering. When did your interest in engineering/science begin? I have had an interest in chemistry, physics, and biology since I was in elementary school, and this interest continued through high school and college. I was considering a career in the health professions, but, after my first real job at HMI, I became hooked on materials engineering. What was your first job in PM? What did you do? In my first job at a PM company (HMI) I worked as an analytical chemist and trained as a process engineer. After graduate school, I worked as a powder metallurgist at Remington Arms Company on their metal and ceramic injection molding program. My first responsibilities included characterizing raw materials and assisting our suppliers in developing material specifications for metal injection molding (MIM). I also worked in the area of metal and ceramic injection molding feedstock development, together with scientists at DuPont.

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

Describe your career path, companies worked for, and responsibilities. I have been with the Powder Metal Products Division (PMPD) of Remington Arms Company for approximately 25 years. I started as a materials engineer and, through the years, remained with the MIM program from the early phases of development to where it is now. During my career in PMPD, I have worked in the areas of materials characterization, debinding and sintering, and many other aspects of MIM processing and component qualification. I currently work as the engineering supervisor of the division. What gives you the most satisfaction in your career? I find the equipment and process troubleshooting aspects of my job to be challenging and rewarding. I also enjoy working with our commercial customers on a variety of MIM applications. I am still learning about this process, even after 25 years. So, I like the continuing challenges and learning opportunities that my job provides. List your MPIF/APMI activities. Currently, I am a member of the Program Committee for the upcoming PM2008 World Congress, I also participate as a member of the Editorial Review Committee of the International Journal of Powder Metallurgy. What major changes/trend(s) in the PM industry have you seen? Because I have been in the MIM and PM industries for a number of years, I have been privileged to witness Engineering Supervisor Powder Metal Products Division Remington Arms Company 14 Hoefler Avenue Ilion, New York 13357 Telephone: (315) 895-3516 Fax: (315) 895-3227 E-mail: [email protected]

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SPOTLIGHT ON ...MARYANN WRIGHT

THE WORLDWIDE LEADER IN GRAPHITE AND CARBON POWDER FOR THE POWDERED METAL INDUSTRY

Enhance Your Powdered Metal Parts And Mixtures With Asbury Graphite NATURAL GRAPHITE

their growth, and, in particular, the MIM industry, from a fledgling technology to a viable, soughtafter metals manufacturing process. I have seen expansion of the applications for both technologies, and acceptance of the technologies, and the consolidation and assimilation of small parts producers into larger companies. Why did you choose to pursue PMT certification? I chose to use certification as a vehicle for training engineers and technicians new to PM and MIM, and, in the process, decided to obtain certification myself. I believe that having professional certification that is recognized by the industry demonstrates a high level of competency to colleagues and customers. For me, it was not only a training tool but also a marketing and career development tool. How have you benefited from PMT certification in your career? Certification helps to convince customers that they are working with an experienced, knowledgeable technical staff member. All of the engineers in PMPD have obtained their PMT Level I certification.

SYNTHETIC GRAPHITE GRAPHITE LUBRICANTS

What are your current interests, hobbies, and activities outside of work? I train at the gym, am active with a local running club, and practice yoga. I just completed my first Boilermaker 15K Road Race in Utica, New York. My husband, Michael, and I are in the process of renovating our summer home, and also spend time with our Little Brother, Nick, through the Big Brothers, Big Sisters Program. ijpm

ISO 9001 - 2000 CERTIFIED

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Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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PM METALLOGRAPHY COMPETITION

WINNING ENTRIES: 2007 APMI INTERNATIONAL PM METALLOGRAPHY COMPETITION, PART II RESEARCH & DEVELOPMENT 1st Place Bruce Lindsley & Gerard J. Golin Hoeganaes Corporation Cinnaminson, New Jersey

Introduction: Graphite, copper, and nickel are the most commonly used additives in ferrous PM. They are added to the base iron or low-alloy steel powders to enhance physical and mechanical properties. Their behavior and benefits are well known and reasonably well understood, but their effect on the pore structure remains more of a mystery. To shed light on this situation, an automated image analysis study was undertaken to help explain the effects of the individual additives and some of their interactions on the pore network.

graphite, 2 w/o Cu or 2 w/o Ni, 2 w/o Cu and 2 w/o Ni, and were copper free or nickel free. In all, eight compositions were selected for testing. The bars were prepared using standard metallographic techniques, backfilled with epoxy using vacuum impregnation, and re-prepared using optimal grinding and polishing practices. This preparation sequence was used to ensure the most faithful appearance of the pore structure. The samples were then analyzed using an automated image analysis system where pore sizes and shapes were measured and calculated. A total area of 4.86 mm2 was examined on each sample at a resolution of 0.36 mm/pixel. In looking at the individual pores, the total population was separated into two groups; small pores 6 mm. The shape analysis is the reason for the split by size because measuring shape on the smallest features skews the distribution toward higher values, thus giving misleading information on the sintering response of the material.

Experimental Procedure: A set of experiments was performed to compare the physical and mechanical properties of FL-4400 (prealloyed 0.85 w/o Mo) base powder with various additions of graphite, copper, and nickel. Transverse rupture (TR) bars were pressed at 690 MPa (50 tsi) and sintered at 1,120°C for 15 min at temperature in a 90 v/o nitrogen/10 v/o hydrogen atmosphere. Sintered densities ranged from 7.05 to 7.09 g/cm3 for the copper-containing materials and 7.09 to 7.18 g/cm3 for the copper-free materials. From these experiments, broken TR bars were selected for metallographic characterization of the pore structure. The bars contained 0.6 or 0.9 w/o

Results: Numbers of pores and the size and shape distributions were measured on each sample. Figure 1 shows the location of the copper particles and the areas where large pores will be located after the melting of the copper. The numbers of pores by mix composition and size group are shown in Figure 2. The 2 w/o Cu/0 w/o Ni samples clearly show a reduction in the total number of pores, especially in the number of pores in the small category. The other three groups show similar results. The number of large pores, defined as features >2,000 mm2 in area, are shown in Figure 3. All copper-containing samples show a large number of the countable pores

THE EFFECT OF ALLOYING ADDITIVES ON PORE MORPHOLOGY—A QUANTITATIVE STUDY

Presented at PowderMet2007 in Denver, Colorado. Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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PM METALLOGRAPHY COMPETITION

with a range of 17 to 22 in the total test area. The copper-free samples showed significantly fewer large pores, five or less for all four compositions. Figures 4 and 5 show the size and shape distribu-

tions using the results from the 0.6 w/o graphite samples. One graphite content is displayed in each case because of the similarity in results to the higher carbon level. In Figure 4, the size distribution for the copper-containing mixes show the presence of larger pores compared with the copper-free materials. The graph is a cumulative plot of the total area occupied by pores of a given size. Therefore, the copper-containing materials show pores >4,000 mm2 while the largest area in the copper -free bars was 2,000 mm2)

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Figure 5. Pore-shape analysis. Curves toward the right indicate smoother, rounder pores

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PM METALLOGRAPHY COMPETITION

(a)

(b)

Figure 6. Backscattered electron images: (a) alloying of copper, (b) copper–nickel. Bright regions indicate the presence of higher atomic number elements. In (a), copper is seen as thin areas between particles or blocky areas filling small pores. In (b), copper appears primarily in large concentrated regions

sample, shifted to the right, indicative of smoother pore surfaces. Discussion: Little difference was seen when comparing the copper-free materials in all categories measured. This is probably due to the fact that all diffusion occurs in the solid state. The two copper-containing materials were similar in relation to the number of large pores and the overall size distribution because of the particle size of the copper powder and the open space remaining as the copper particles melt. However, the total number of pores, both large and small, and the shape distribution show distinct differences. The number of small pores in Figure 2 is reduced by as much as 40% when comparing the copper– graphite sample with the copper–nickel–graphite, and the copper-free samples. A smaller reduction is seen in the larger pores shown in Figure 2, namely 10%–15%. Additionally, a major difference in pore shape is seen in the copper–graphite samples compared with the other three sets. A smoothing of the pore surfaces is seen due to the

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

liquid copper traveling along the particle surfaces (pore edges) and filling in asperities and small pores. This is not the case in the copper–nickel sample where the liquid copper runs along the boundaries until it encounters an area rich in nickel and alloying occurs with the nickel and copper (Figure 6). Alloying prevents the flow of copper along the pores, and therefore the loss in the pore numbers and the smoothing of the pore edges is not seen. Summary: Graphite and nickel appear to have similar effects on the size and shape of the pore structure due to solid state diffusion during sintering. However, the presence of liquid copper during sintering has a major effect on the number of large pores, and on the pore size distribution in all the copper-containing materials. The presence of nickel appears to interfere with the distribution of liquid copper and, consequently, reduces the effect on the reduction in the number of pores and the pore shape.

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PM METALLOGRAPHY COMPETITION

RESEARCH & DEVELOPMENT 2nd Place Louis G. Campbell Metallurgical Engineer Eaton Electrical 200 Westinghouse Circle Horseheads, New York 14845 GRAVITATIONAL EFFECTS ON LIQUID-PHASE MICROSTRUCTURES IN TUNGSTEN– NICKEL–IRON

93 w/o W/NiFe: Microgravity sintered 120 min at 1,500°C. Slip lines in liquid phase

SAMPLES: 35 w/o W/NiFe, 78 w/o W/NiFe, and 93 w/o W/NiFe alloys with 7:3 Ni:Fe weight ratio Liquid-phase sintered at 1,500°C for varying times under vacuum in orbital microgravity and on Earth PREPARATION: Section with precision wafering saw (Struers Accutom-5, alumina blade)

78 w/o W/NiFe: Earth sintered 180 min at 1,500°C. Slip lines in liquid phase

35 w/o W/NiFe: Earth sintered 180 min at 1,500°C. Slip lines in liquid phase. Anisotropy of indent on grain boundary 35 w/o W/NiFe: Microgravity sintered 600 min at 1,500°C. Immersion etched 90 s with 60 mL methanol, 15 mL HCI, 5 g FeCl3

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Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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PM METALLOGRAPHY COMPETITION

Hot compression mount, transparent acrylic (Struers Specifast) Wet hand grind, 320 grit SiC paper to unmask/ plane Wet hand grind, 600 grit equivalent Trizact (Leco Corp) Autopolish (Struers RotoPol-4 using Struers cloths): 9 µm polycrystalline diamond, MD-Plan, 2 min, 25N/sample 9 µm polycrystalline diamond, MD-Dac, 2 min, 25N/sample

35 w/o W/NiFe: Ground sintered 600 min at 1,500°C. Immersion etched 90 s with 60 mL methanol 15 mL HCI, 5 g FeCl3

3 µm polycrystalline diamond, MD-Dac, 2 min, 25N/sample 0.04 µm silica (Struers OP-S), MD-Chem, 4-6 min, 25N (only samples not used for hardness testing) HARDNESS TESTING: 10 kgf Vickers (Leco V-100C) Diagonal lengths by image analysis

35 w/o W/NiFe: Microgravity sintered 600 min, 1,500°C. Immersion etched 90 s with 60 mL methanol, 15 mL HCI, 5 g FeCl3

35 w/o W/NiFe: Earth sintered 180 min at 1,500°C 180 min at 1,500°C

35 w/o W/NiFe: Microgravity sintered. 180 min at 1,500°C

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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PM METALLOGRAPHY COMPETITION

35 w/o W/NiFe: Earth sintered 180 min at 1,500°C. Vickers hardness indents

35 w/o W/NiFe: Microgravity sintered 180 min at 1,500°C. Vickers hardness indents

During a study of the effects of gravity on the mechanical properties of liquid-phase sintered tungsten–nickel–iron alloys, the hardness of the segregated liquid phase in 35 w/o W/NiFe sintered in the Earth’s gravity was found to be significantly higher than either the settled tungsten-grain region of the same sample, or the sample sintered in microgravity with evenly dispersed tungsten grains. The increase in hardness in the settled region can be explained by the higher contiguity of the settled region formed by gravity. The increase in hardness in the segregated liquid-phase region could not be explained by tungsten continuity. Examination of the hardness indents revealed slip lines generated by the indents in the liquid phase for all three alloy compositions studied. The slip line pattern, plus anisotropy, on a hardness indent near a matrix grain boundary away from the gravitationally settled region, indicated a difference in grain-to-grain liquid-phase properties. Etching revealed a lamellar microstructure in the Earth-sintered 35 w/o W/NiFe liquid phase, away from the settled-grain region. Identical etching of microgravity sintered 35 w/o W/NiFe found

16

little occurrence of the lamellar structure. SEM/EDS of the etched Eearth-sintered liquid phase found smooth grains free of lamellae, typically bordered by tungsten precipitates or near tungsten grains, as well as the tungsten-rich lamellar regions. The smooth matrix microstructures were formed by heterogeneous nucleation during solidification, and the harder lamellar region was for med by homogeneous nucleation in the absence of heterogeneous sites such as tungsten grains or high-angle grain boundaries. The even distribution of tungsten grains in the microgravity-sintered sample prevents formation of these lamellar matrix microstructures, resulting in a lower hardness in the matrix phase.

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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PM METALLOGRAPHY COMPETITION

RESEARCH & DEVELOPMENT 3rd Place Professor Carl Blais & Maude Larouche Laval University Department of Mining, Metallurgical and Materials Engineering 1728 Pavillon Adrien-Pouliot Québec G1K 7P4 Canada

TABLE I. COMPOSITION OF MIXES

Mix A Mix B Mix C

C (w/o)

Si (w/o)

Cr (w/o)

Nb (w/o)

Fe (w/o)

4.5 4.5 4.5

3.0 3.0 3.0

30.0 30.0 30.0

-----5.0 10.0

Bal. Bal. Bal.

IRON-BASE WEAR-RESISTANT COATINGS WITH CHROMIUM CARBIDES VIA LIQUIDPHASE REACTIVE SINTERING INTRODUCTION Hardfacing refers to the deposition of hard, wear-resistant coatings on the surface of a component using welding processes (FCAW, SMAW, SAW).1 The attendant surface modification leads to reduced loss of material by erosion, abrasion, impact, etc. Nevertheless, many alloys containing chromium carbides check-crack during cooling. Such cracks are the result of high stresses induced by the contraction of weld metal as it cools. They typically propagate through the thickness of the weld bead and generally stop at the parent metal, provided it is not brittle. The presence of a high density of cracks leads to premature degradation of wear resistance. METHODOLOGY Table I presents the composition of the three different alloys studied. Niobium was added to mixes 2 and 3 in the hope that it could pin the primary chromium carbides in order to minimize their growth and retain their mean diameter under 50 µm. The chemistries presented in Table 1 were obtained using different amounts of powders of ferrochromium, ferroniobium, ferrosilicon, graphite, and iron. Samples were pressed using transverse rupture (TR) tooling to obtain bars with a density equivalent to 90% of the pore-free level of the alloy, and a thickness of 5 mm. Sintering was carried out in a tube furnace at a temperature of 1,225°C for 1 h under an atmosphere of argon. Each sintering test consisted of placing two TR bars from the same mix on an 18-gage sheet of low carbon steel (AISI/SAE 1005). A 5 mm space was initially left between the two TR bars prior to sintering. Figure 1 presents a plan view of the coating after sintering. Note that liquid formation has filled the space between the TR bars so that

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

Figure 1. Plan view of coating obtained after sintering. Morphology of the initial TR bars can no longer be distinguished

they can no longer be distinguished. Finally, a series of samples from mix C were quenched after sintering to characterize the effect of rapid cooling on the final hardness of the coating, as well as its propensity to cracking. OBJECTIVE Develop a wear-resistant coating that could be obtained by liquid-phase reactive sintering. Specific goals: • Develop a microstructure consisting of chromium carbides and niobium carbides dispersed in an iron matrix using a water-atomized iron powder and particulate ferroalloys • Control the reactive sintering process to obtain a pore-free microstructure and a carbide size 100 m2/g). This material is then coated with a catalyst (nickel, palladium, platinum, etc.) by precipitation or electrochemical methods. At PowderMet2007 there were three sessions devoted to nanomaterials plus nine other nanorelated papers and three nano-related posters.

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There is a lot of “nano” going on with some of it renaming the old and traditional, some new and with exciting potential. The challenge is to separate the wheat from the chaff. Is the term “nano” applied correctly? Is “nano” specific to PM, or is it a natural and common artifact of materials in general? It is time to use some macro critical thinking. So, if you are an engineer in a conventional ferrous press-and-sinter shop and your customers, or your management or marketing staff, are pushing you to do something nano, tell them nano is in the future of PM—and is likely to remain so!

Q A

What are the main heat-transfer mechanisms in sintering and their effects in different furnace types? In general, there are only three heat-transfer mechanisms, whether we are talking about a sintering furnace or the backyard grill. Heat transfer occurs from a hot entity to a cooler one by: (1) conduction, (2) convection, and (3) radiation. Heat transfer is actually the transfer of thermal (kinetic) energy from hot material (rapidly moving atoms or molecules) to cooler material (lower-energy atoms and molecules). Conduction is the transfer of thermal energy by direct contact between the hot and cold entities. Heat transfer occurs through the contacting interface. The rate of heat transfer is generally considered to be proportional to the temperature difference between the two entities. However, the rate is also dependent on the material properties (thermal conductivity), the amount of interface involved in the heat transfer, and the contact efficiency of the interface. Convection is heat transfer between bodies through a fluid (or within a fluid), such as the atmosphere in the furnace. As the temperature of the fluid changes, its density changes with respect to the surrounding furnace atmosphere. This causes gravity-induced flow, which allows continued thermal transfer to, or from, the fluid. To increase the heat-transfer rate, the motion of the fluid can be enhanced by forced circulation. Again, the rate of heat transfer is generally considered to be proportional to the temperature difference between the two entities. However, the rate is also dependent on the material properties of the solid and the fluid (thermal conductivity, heat capacity, and viscosity) and fluid velocity. In general, the more conducting the fluid, and the higher the velocity of the conducting fluid, the greater the Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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Brian Orges

Barbara McElwee

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T: 440.243.5151 Ext 226 | F: 440.243.4868 Email:[email protected]

T: 440.243.5151 Ext 250 | F: 440.243.4868 Email:[email protected]

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Industries and Specialties

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PrincetonOne Cleveland offers our clients a team of recruiting specialists who provide customized staffing solutions in the following industries and positions:

• Our business focuses on all levels throughout large and small manufacturing companies. • We have an established database of over 18,000 candidates. • Success and experience in single search assignments and large expansion projects • Domestic and international services Our clients have entrusted MRI Cleveland with staffing projects that have ranged in size from a single opening to more than 1000 openings at various levels and locations. Our Project Fulfillment Team is repeatedly requested because of our proven track record and ability to guarantee results. We are: • Consistently ranked in the top 5% of Worldwide offices • Winners of the prestigious Gold Club from 1999-2002 • Presidents Club winners in 1994, 1995, 1996, 1997, 1998

PrincetonOne of Cleveland provides: • Quality Candidates. We deliver only the highest caliber candidates, those who not only surpass your skill requirements, but who are also a good fit with your company culture. • Quick Results. Information sharing and support among our offices nationwide, and globally through the MRI, network, results in speedy and efficient searches. • Convenience. You deal with only one single point-of-contact for all your needs. • Commitment. We act as your strategic business partner, learning your company inside and out. This allows us to think beyond immediate assignments and quickly deal with new challenges when they arise.

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About MRI PrincetonOne is an affiliate of Management Recruiters International, Inc. MRI is the largest company of its kind in the world. MRI has over 1100 offices in 26 countries, and completes 45,000 searches annually. MRI provides both global resources and the latest technology that makes it possible to find and place the kind of top quality candidates our clients expect.

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NEXT JUNE THE PM WORLD CONVENES IN WASHINGTON, D.C. 2008 World Congress on Powder Metallurgy & Particulate Materials June 8–12, Washington, D.C. • International Technical Program • Worldwide Trade Exhibition • Special Events

This global PM event is sponsored by:

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

In cooperation with: GAYLORD NATIONAL RESORT & CONVENTION CENTER National Harbor on the Potomac

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CONSULTANTS’ CORNER

heat-transfer rate. The fluid can also be a liquid such as the molten salt in a salt bath, which is common in heat-treating applications. Radiation is the heat transfer of thermal energy by photons. All bodies radiate photons whose energy is related to the temperature of the body. The rate of heat transfer is proportional to (Th4Tc4), where Th and Tc are the temperatures of the hot and cold bodies, respectively. The rate of heat transfer is influenced by the emissivities of the bodies, which are essentially the efficiencies with which the bodies radiate and absorb photons (dark rough surfaces have high emissivities, shiny reflective smooth surfaces have low emissivities). Photons do not need a medium such as a gas or solid to travel, thus they can travel through a vacuum. Also, photons do not actually go around corners so heat transfer is considered “line-of-sight.” This means that only the portion of the surfaces in sight of each other can exchange thermal energy. One can see that any type of furnace or heating device will rely on all three heat-transfer mechanisms, but to different degrees. Sintering furnaces are usually either atmosphere furnaces or vacuum furnaces. Atmosphere furnaces can be batch or continuous. High-vacuum furnaces are of the batch configuration. No sintering furnace relies directly on heat transfer through conduction since PM parts do not contact the heating elements. Heat transfer is achieved through convection and radiation. But conduction still plays a part. Sintering furnaces have some form of heating element or hot surface. Heating elements are usually heated by electrical resistance. Fuel-heated furnaces employ the heat of combustion to heat a muffle, which becomes a hot surface, or use heated combusted gases as the heat source to convect directly with the parts (usually kilns for ceramics rather than metallic parts). For most metal-partsintering applications, a muffle is used to contain the parts and the protective or reducing sintering atmosphere. Thermal energy is convected from the hot muffle to the cold parts by circulation of the gas atmosphere. The heating rate is dependent on the magnitude of the gas flow rate. Continuous furnaces generally use much higher rates of gas flow, thus they are able to heat parts more rapidly. Batch furnaces use lower atmosphere flow rates. At low flow rates heat transfer is predominantly by natural convection. Forced convection, and the attendant higher heat-transfer rate, is achieved at higher gas flow rates. Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

Higher gas flow rates also produce a more uniform temperature environment in the furnace as the kinetics of heat transfer are higher and thermal equilibrium is approached more rapidly. Forced convection can be achieved by high gas flow rates, or by the use of a fan. Temperature uniformity is generally considered to be optimal in a continuous furnace. This is also a result of the relatively small area cross section of the muffle (measured perpendicular to the direction of movement of the parts). Although convection is greater in a continuous furnace, the high heating rate is also primarily a result of the existence of a preheated muffle. Batch furnaces start cold and the furnace must expend energy and time to bring the furnace and parts up to temperature. Thus, the area under the time–temperature curve can be much greater for a batch vs. a continuous furnace. While it is true that convection is important in atmosphere furnaces, so is radiation heat transfer. Heating elements radiate thermal energy to the muffle, which in turn radiates thermal energy to the parts; thus radiation is essential to heating the muffle and the parts. Heat transfer to the parts is shared by radiation and convection. The exact amount of each mechanism is dependent on the design of the furnace, the atmosphere flux through the furnace, and the operating parameters (heating rate). Continuous furnaces may rely on >50% convective heat transfer, while batch furnaces may rely on >50% radiative heat transfer. Setters and other furnace furniture also play a big part in heat transfer. Ideally they should be made of a material of high emissivity and thermal conductivity. Graphite setters are often used for this reason. But many material applications cannot use graphite and ceramics are used instead. These compromise the heat transfer from conductivity and radiation. This is more of a factor in continuous furnaces where high heating rates are produced. The thermal lag caused by a setter is essentially a temperature gradient. Vacuum furnaces rely primarily on heat transfer by radiation. The higher the vacuum, the greater the contribution to heating by radiation heat transfer. Most vacuum furnaces use a shield around the heating elements. This shield, by virtue of being made from a material with a high thermal conductivity, smoothes out the hot spots produced by the heating elements to provide a more uniform radiating surface to the parts. But the heating is still line-of-sight,

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CONSULTANTS’ CORNER

TRUST must be earned For 90 years, ACuPowder has been delivering the finest quality powders and the most conscientious service. Our customers know that serving their needs and solving their problems is our highest priority. Bring us your toughest assignments. We want to earn your trust, too. The finest powders are from ACuPowder: Copper, Tin, Bronze, Brass, Copper Infiltrant, Bronze Premixes, Antimony, Bismuth, Chromium, Manganese, MnS+, Nickel, Silicon, Graphite and P/M Lubricants.

901 Lehigh Ave., Union, NJ 07083 908-851- 4500, • Fax 908-851- 4597

6621 Hwy. 411 So., Greenback, TN 37742 865- 856- 3021 • Fax 865-856 -3083 e-mail: [email protected] web: www.acupowder.com ISO 9001 CERTIFIED

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which is why placement of the parts is more critical than in other furnaces. Parts can block other parts and setters can also shield parts. In some cases the setters may heat first and then the parts are heated by both radiation from the setter and conduction from the setter. The amount of convective heat transfer is essentially negligible in high vacuum. Once at thermal equilibrium (sintering temperature) the temperature gradients smooth out as all parts, setters, and furnace hardware radiate and absorb equally. It is the time to achieve the equilibrium temperature that produces the temperature gradients. And with temperature gradients there are sintering gradients, which can lead to density and property gradients and distortion in PM parts. In any furnace the objective is to produce an environment with a high degree of temperature and atmosphere uniformity and control. The more heat-transfer mechanisms that are active the greater the temperature uniformity in the furnace. Convection plays a major role in temperature uniformity, which may imply that a continuous furnace is best. However, better atmosphere control is achievable with batch or vacuum furnaces, and some materials require this. Two last items. First, the thermal properties of the part are also important in heat transfer. The green PM part is usually matte and porous and the sintered part can be shiny and dense. This implies that its emissivity is higher and its thermal conductivity lower when in the green state. Thus, the mechanisms of heat transfer within the part change during sintering, which can lead to temperature gradients within the part, especially in large parts. This can contribute to density gradients and distortion. Second, parts subjected to microwave or induction sintering are heated by joule heating. Thermal energy is produced internally in the part by resistive heating. Microwave or induction energy transfer is material dependent. Microwaves are transferred efficiently to a lowdensity green part and can be reflected by a highdensity sintered part. Induction energy couples best with a dense part and may not couple well to a green part. Thus, these two alternative heating methods are also not without challenges. 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 085406692; Fax (609) 987-8523; E-mail: [email protected] Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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PERSONAL INSIGHTS

AXEL MADSEN/CPMT SCHOLAR REPORTS PHILIPPE LAPOINTE Laval University Quebec, Canada PowderMet2007 was the first professional conference I ever attended. I have to admit that before the conference, I was slightly nervous and thrilled, considering the importance of the occasion. However, the first few events made me realize there was nothing to be worried about. Indeed, the friendly mind-set surrounding the conference was astonishing. I knew few people attending the conference before my arrival at the convention center, but my advising professor introduced me to his peers. In this way, I had the opportunity to meet some of the pioneers in the PM community. Also, the city in which the convention took place was amazing. Even though Denver stole the Quebec Nordiques, it is still a gorgeous city! The breathtaking view of the natural marvel that the Rocky Mountains constitute, and the cleanliness of the city, are just a few reasons that make Denver so beautiful. I would like to say that I am deeply thankful to the Scholarships & Grants Committee of the Center for Powder Metallurgy Technology for giving me the opportunity to enjoy this rewarding experience. One of the things that impressed me the most about PowderMet2007 was the overall structure of the conference. It started with social events such as the golf tournament and the welcoming reception in order to develop a friendly atmosphere. Then a wide array of technical sessions allowed everyone to find the subjects of primary interest. In my case, many of the sessions were closely related to my thesis project. The sessions on nanoscale powders enlightened me about ways to

produce nanoscale powders and the economic issues related to their use, while the sessions on sintering taught me about new sintering techniques such as microwave sintering. The convenient schedule of the conference allowed everyone to maximize attendance at presentations without having to run from one end of the conference hall to the other. Another surprising aspect of this event was the open-mindedness of everyone. No matter if you were a ”regular” or attending for the first time, no matter where you came from, as long as you spoke English (or tried to!), everyone was pleased to meet one another. It was also a great opportunity for people from academe to meet PM industry practitioners and vice versa. The social activities such as the night at Coors Field certainly enhanced the high level of networking opportunities. In the end, attending PowderMet2007 was a great opportunity for me to improve my knowledge of PM and particulate materials. I hope that eventually I will have the chance to renew this experience. It was a perfect occasion to meet people in the PM industry and colleagues in research, and to create new bonds or just reinforce existing ones. CASEY MCCLIMON Arizona State University Tempe, Arizona Before my advising professor approached me about the CPMT/Axel Madsen Conference Grant, I had only a vague idea about technical conferences. When I found out that I had been selected to attend PowderMet2007 in Denver I was really excited and could not wait to go. With the grant I would be able to experience the full conference,

Axel Madsen/CPMT Grants are awarded to deserving students with a serious interest in PM. The recipients were recognized at the Industry Recognition Luncheon during PowderMet2007.

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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AXEL MADSEN/CPMT SCHOLAR REPORTS

including taking part in the poster session. The conference was unforgettable and I would like to share some of my experiences with you. I would like to thank Professor Nik Chawla for nominating me, and the Scholarships & Grants Committee of the Center for Powder Metallurgy Technology for giving me the opportunity to attend. On Sunday I flew to Denver and began my conference experience. The conference was held in downtown Denver which gave visitors the opportunity to experience some of the downtown culture. I stayed at the hotel across the street from the convention center so it was easy to get to and from the conference. Coming from Arizona where there was currently a heat advisory, the cool weather in Denver was literally a breath of fresh air. That evening I attended the welcoming reception, the first social event of the conference. The reception allowed for old and new colleagues to gather and relax with a drink and catch up with each other. There were many people there and I looked forward to meeting some of them. This was my first technical conference and one of my biggest PM experiences. I had little knowledge of the PM industry, aside from the research I had been doing under the guidance of my professor at Arizona State University. I think that the reception would have been a better first experience if I had had someone to shadow and introduce me to people they knew. I enjoy speaking to new people, but no one seemed to want to interact with me. I came to the conference without any of my peers and I felt alone, somewhat rejected and slightly uncomfortable. So I left the reception early and headed back to the hotel to get some sleep and prepare for a full day of sessions. On Monday I attended the opening general session which was my first look into what MPIF and APMI are all about. The keynote speaker was Clyde Fessler, the former VP of business development for Harley-Davidson Motor Company. Everyone has heard of Harley-Davidson motorcycles so it was interesting to hear him talk about the ups and downs the company went through and what he learned from all of those experiences. His talk presented the four P’s of marketing; product, price, promotion, and place. Another P that he mentioned that is, if not, more important, was people. Mr. Fessler was an animated speaker and it was enjoyable to listen to him. His motivation and techniques were both inspiring and doable. I think that everyone benefited from listening to his

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speech. After the opening session, I headed off in search of some of the other presentations that were offered that day. The first session I attended was on fatigue. It so happened that my advisor, Professor Chawla, was the first speaker. He spoke about how cracks due to fatigue could actually show preferential cracking due to the large amount of porosity within PM steels. This topic was close to what I was studying for my poster project. After his talk I stayed in the fatigue session listening to the remaining speakers. At the Industry Recognition Luncheon, as a CPMT/Axel Madsen Conference Grant recipient, I was pointed toward a reserved seat near the front of the room. Soon after I arrived I had the privilege of meeting the chairman of the Scholarships & Grants Committee of the Center for Powder Metallurgy Technology. After a while more people began to arrive and I soon met the other three grant winners. The lunch was great and I was able to socialize with many people in the PM industry and I got to see the results of the metallography contest. I love microscopic images, so seeing all of the artistic and natural images captured under a microscope was really interesting to me. It would be cool to enter the competition in the future because it is amazing how beautiful even the most basic things are when you get down to the atomic and microscopic level. After lunch the Exhibition Hall opened for conference attendees. Many different companies set up booths in the hall promoting their services relating to the PM industry. Not knowing a whole lot about the PM industry I knew even less about the companies involved, so as I walked through the exhibits it was interesting to see all of the different companies. Also in the exhibit hall, the design excellence awards were on display. I have not had much experience with PM so I was surprised at the many different applications covered. The items displayed ranged from all kinds of applications such as handcuffs, dental braces, hearing aids, and automotive parts. After my first day I was feeling a little better about being in a new place. It was easier to be at the conference after having met the other grant winners because they were more my age and shared more of my interests. On Tuesday, I attended the speaker meet-andgreet and enjoyed a bagel and coffee with the other grant winners. While there, the new president of APMI approached me and let me know Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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AXEL MADSEN/CPMT SCHOLAR REPORTS

that my poster had been given one of the “outstanding poster” awards in the poster competition! I did not expect to get any sort of recognition so I was very excited. Later I attended the PM Design Excellence Awards Luncheon which highlighted the winners in the 2007 competition. And after lunch it was time to stand with my poster and answer questions from onlookers. Almost everyone who came by was impressed. It was really satisfying to have other people excited about something I was doing. Tuesday night was the main social event of the conference, “An Evening at Coors Field.” The accommodations we were given at the game were unbelievable. A baseball game will never be the same. We were served an amazing dinner in a luxury suite and the night got even better when I found out that the Colorado Rockies were playing the Arizona Diamondbacks. It almost felt like home! Unfortunately for the home team, the D’backs won! I met a lot of new people and I had a great time. It was one of the highlights of the conference for me. On the last day I attended more sessions and finally took down my poster and headed back to Phoenix. The experience I had in Denver was unforgettable. I was a CPMT/Axel Madsen Conference Grant recipient, I was able to attend this amazing conference in a great city, and to top it all off, I was one of two recipients of the “Outstanding Poster” award. I am so glad I was able to go to PowderMet2007 and I would definitely encourage anyone in the PM industry to attend the 2008 World Congress on Powder Metallurgy & Particulate Materials in Washington, D.C. DONALD SAMPSON Pennsylvania State University University Park, Pennsylvania I will be the first to admit that I was very skeptical at the thought of attending PowderMet2007. Having never been to a conference before, I was intimidated by a lack of experience. Day-to-day, I wasn’t sure what sort of functions I would be attending, and what would be expected of me. Also, having to present a poster covering my own research and the kinds of questions or criticisms I might endure was a frightening prospect. Finally, the simple fact that beyond my advisor and one other student I did not really know anyone attending the conference put me ill at ease. Upon arriving at PowderMet2007, all these fears were Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

quickly laid to rest. In the end, PowderMet2007 proved to be a most enjoyable and rewarding experience that was worthwhile professionally, academically, and socially. Arriving at the Hyatt Regency I was awed by the luxuriousness and elegance of our accommodations. This spectacular hotel provided excellent service and location adjacent to the Colorado Convention Center. In addition, the downtown location made for easy access to any number of Denver’s numerous attractions. It did not take long after the conference began for me to become comfortable with this new experience. The opening general session was nothing short of spectacular, inspiring the desire to strive for excellence in the field of powder metallurgy (PM). The keynote speaker, Clyde Fessler, formerly of the Harley Davidson Corporation, was charismatic, interesting, and funny during his presentation titled “The Rise and All of Harley-Davidson: The Building of a Brand.” From this point on, and to the conclusion of the conference, all my worries were allayed as I realized what a tight-knit community the PM industry really is. During the technical sessions, lunches, and conference events I met with former students from my own program, other students who participated in an international research experience with me, and professionals whose interests brought them in and out of my laboratory from time to time. In addition, I met numerous other people from a variety of backgrounds who, along with my fellow CPMT/Axel Madsen Conference Grant recipients, made the trip to Denver rewarding. This was particularly enjoyable as we took time to sample many of Denver’s best microbrews, steaks, and attended the conference’s main social event, “An Evening at Coor’s Field.” The professional and academic significance of attending the conference should not be undervalued. The technical sessions allowed me to broaden my horizons as to the cutting-edge technology on the forefront of the PM industry. Also, visiting the booths at the exhibit allowed me to talk with representatives from some of the finest companies in the PM industry. Finally, I would like to thank the Scholarships & Grants Committee of the Center for Powder Metallurgy Technology for selecting me for this wonderful experience, and my advisor Dr. Ivica Smid for nominating me. After all the uncertainty, the only disappointing part of PowderMet2007

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was when I had to finally leave the wonderful city of Denver. MIKE SEXTON Drexel University Philadelphia, Pennsylvania I would first like to thank the Scholarships & Grants Committee of the Center for Powder Metallurgy Technology for awarding me the funds to attend PowderMet2007 and my advisor, Professor Zavaliangos, for my nomination. Having been introduced to powder metallurgy (PM) last summer, it seemed like a niche process that only a few places performed. Consequently, it was surprising to see such a large number of attendees. Being a motorcycle owner and enthusiast, I found the keynote presentation by Clyde Fessler particularly interesting. I think he opened a lot of minds to creative ways of thinking for increasing the use and awareness of PM. Looking through the session schedule I noted that not only educational institutions but researchers from companies played a large part in the technical presentations. It was confusing to see companies sharing their efforts with their competitors, but as the day went on I realized that the PM industry is one that prefers to grow as a family rather than as cutthroat competitors. This realization was even more apparent as I attended the luncheons and other social events and began talking with other attendees. At the opening luncheon I spoke with two brothers, both with their own PM businesses. Listening to their perspective on the PM industry and how it has provided them with a rewarding career added newfound depth to my purpose at this event. Eager to learn as much as possible about ongoing research in powders, I was disappointed to realize that many presentations occurred concurrently. Fortunately, only on two occasions did I feel torn between any two. The breadth and diver-

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sity of topics presented offered something for everyone. Between modeling, sintering, atomization, and property enhancement, you would have had to tie me down to keep me in one room. Ever since I witnessed the atomization of a superalloy showering the cryogenic bath in the belly of a pilot gas atomizer, I cannot get enough of the new and interesting ways materials are being disintegrated into powders. Naturally, the sessions on centrifugal and close-coupled atomization methods provided grist for my curiosity mill. Not only were the technical sessions informative, but I learned a lot from discussing the products and services of the companies at their booths in the exhibit hall. I was intrigued by the use of coupled vibration and sonic energy resonance to increase the efficiency of sifting powders. I also enjoyed discussing the mechanics of spark plasma sintering and where research efforts are being directed in the companies that provide this service. I had an inkling that attendees would have little interest in my research on pharmaceutical powders and even though I was only asked one question, I relished the opportunity to speak with the other CPMT/Axel Madsen Conference Grant recipients and poster authors about their research and their involvement in PM. And now, as I am sure the other recipients have noted, I will reiterate the importance of an open forum amongst academe and industry to foster advancement and fuel progression. Well aware of the knowledge and experience gap between myself and the majority of the attendees, I never once felt anything less than a peer. I was even mistaken twice for a business owner while en route to Coors Field. I hope I get the chance to see everyone again in Washington, D.C. next year at the World Congress. Again, I extend my infinite gratitude to the Scholarships & Grants Committee of the Center for Powder Metallurgy Technology for granting me the opportunity to participate in PowderMet2007. ijpm

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ENGINEERING & TECHNOLOGY

LUBRICANTS FOR HIGHDENSITY COMPACTION AT MODERATE TEMPERATURES Lhoucine Azzi,* Yannig Thomas** and Sylvain St-Laurent***

INTRODUCTION The quest for parts with high density fabricated by inexpensive shaping processes is a constant focus of the PM industry. Cost effective compaction processes available to the PM industry in the production of high-green-density components are die-wall lubrication, warm compaction, and cold compaction using specialty lubricants. Warm pressing,1 which involves pressing a preheated powder mix in a heated die (~100°C to 180°C), enables the fabrication of parts with high density and green strength by increasing the ductility of the ferrous powder particles. The gain in green density achieved by warm compaction compared with conventional cold compaction generally ranges between 0.12 and 0.30 g/cm3. The main drawbacks to this technology are the need for specialty presses and tooling to heat both the powder mix and the die. The need for internal lubricants to provide adequate lubrication at the die walls during both the compaction and ejection steps adds to the complexity of this process. Die-wall lubrication2 is also a promising route to promote high green density when high compacting pressures are used. The benefit of this technique is the possibility of significantly reducing the internal lubricant level in the powder mix, while maintaining good lubrication at the die walls during compaction and ejection of the parts. This technique is not widely used on a mass production scale because of concerns regarding its reliability. Recent improvements appear to have addressed most of these concerns.3 Cold compaction using conventional lubricants, such as metallic stearates or amide-based waxes, does not generally yield high-greendensity parts. Recently, more effective lubricants have been developed for conventional compaction at room temperature. Hammond 4 describes a lubricant system which is solid at ambient conditions, but which transforms to a liquid phase upon the application of pressure. It is claimed that this lubricant can be used at a reduced concentration due to the efficiency of lubrication arising from the transformation from solid to liquid. Because less lubricant is used, the green density

The nature of the lubricant and the conditions of compaction, in particular the temperature and pressure, affect the densification of powder metallurgy (PM) powder mixes. While the effect of pressure on densification is straightforward, the effect of temperature is more complex. Depending on the lubricant, an increase in the compaction temperature can significantly affect the level of friction at the die walls, as well as the lubricant distribution in the compact, and therefore affect the compressibility of powder mixes. In this study, the compressibility and lubrication behavior of PM powder mixes containing conventional and new lubricants for high-density applications are reviewed. The effect of temperature on the pressing response of powder mixes containing the new lubricants is assessed.

*Research Associate, Materials and Processes/Powder Forming, **Research Officer Industrial Materials Institute/National Research Council Canada, 75 de Mortagne, Boucherville, Québec, Canada J4B 6Y4; E-mail: [email protected], ***Director, Product Development, Quebec Metal Powders Limited, 1655 Marie Victorin, Tracy, Québec, Canada, J3R 4R4

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LUBRICANTS FOR HIGH-DENSITY COMPACTION AT MODERATE TEMPERATURES

is increased. Compaction processes in which a nonheated powder is compacted in a heated die have also been developed. 5 The temperatures involved are ~60°C; thus presses with specialty tooling are not required. In addition, the flowability of the powder mixes is less of a concern than in warm compaction in which the powder mix is heated. In this study, the compressibility and lubrication behavior of PM powder mixes containing conventional and new lubricants for high-density applications are reviewed. The effect of the compacting temperature on PM powder mixes containing the new lubricants is evaluated. BACKGROUND Several factors affect the green density of PM parts. Among these factors are friction at the die walls, the intrinsic compressibility of the powder, and springback after ejection.6 Friction at the die walls can be described by the sliding coefficient, η.7,8 For a cylindrical part of dia. D, compacted in a single-action press, the sliding coefficient at the completion of compaction can be calculated from the relation: η = (Pt/Pa)

AF [—— SH ]

(1)

where Pa is the pressure applied to the punch, Pt is the pressure transmitted to the stationary punch and H is the height of the cylinder. F is the cross-section area and S is the cross-section perimeter. Numerical values of η vary from 0 to 1: the higher the sliding coefficient, the lower the friction at the die walls, and the more uniform the density through the compact. The intrinsic compressibility of the powder is a measure of the densification of a powder mix, in the absence of friction at the die walls, i.e., the pressure transmitted to the powder compact is equal to the applied pressure. This pressure can be evaluated by the relation between the average IN die density (the density of the part under pressure) and the average pressure seen by the compact. It has been shown7,8 that, for a cylindrical compact of dia. D, the average pressure (net pressure) PNET can be evaluated utilizing the relationship: PNET = Pa*η

H (—— 2D ) = (P *P )1/2 a t

(2)

The green density of a PM compact is usually

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described in terms of the percentage of its porefree density (i.e., the density of a pore-free powder compact). In practice, the maximum green density attainable is ~98% of the pore-free density. The pore-free density is a function of the composition of the powder mix. Alloying additions such as copper and nickel increase the pore-free density of iron-base powder compacts while graphite and lubricant lower the pore-free density. The lubricant, with a density ~1 g/cm3, is the additive that has the largest effect on the pore-free density of a PM compact. For example, the effect of the concentration of an admixed lubricant (density 1 g/cm3) on an FC0205 powder mix containing 2 w/o copper and 0.6 w/o graphite is shown on Figure 1. A way to increase the pore-free density and green density is to reduce the lubricant concentration in the powder mix. However, this can prove to be difficult from a practical point of view. Indeed, lowering the lubricant content can dramatically increase friction at the die walls and impede compaction. Another strategy to increase the green density of a PM compact is to use alternative lubricants and processing conditions that favor expulsion of the lubricant from the green compacts during compaction. For a given lubricant concentration, this should increase the pore-free density and, as a result, the green density. It was shown9 that the compressibility of stearate/steel mixes could be improved by increasing the compacting temperature. However, this was not attributed to the higher amount of lubricant expelled from the green compact at a higher temperature, but rather to

Figure 1. Effect of lubricant content (density 1 g/cm3) on the pore-free density of a FC0208 powder mix

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LUBRICANTS FOR HIGH-DENSITY COMPACTION AT MODERATE TEMPERATURES

enhanced plastic deformation of the metallic particles during compaction. Moreover, the green density improvement was limited because of the significant increase in friction at the die walls as the compacting temperature was raised. For certain stearate/steel mixes, this gave rise to “stick and slip” during ejection. Friction at the die walls increased by as much as 15% when the compacting temperature was raised from room temperature to the softening points of the lubricants. This was attributed to the low viscosity of the lubricant under these compacting conditions. In a study on lithium stearate/steel mixes,10 it was confirmed that the higher green density measured at the higher temperature was not due to expulsion of the lubricant from the compact. A study of the lubricant distribution in the compacts showed that the lubricant had a tendency to flow towards the die-wall surface, but under the compacting conditions used, a limited amount of lubricant was expelled from the compact. It must be emphasized that in both studies, the compacting pressure was limited to 620 MPa (45 tsi) due to insufficient lubrication on the die walls that prevented the application of higher pressures. This could explain the small quantity of lubricant that was expelled from the green compacts. Lubricant systems that exhibit compatible rheological behavior at moderate compacting temperatures (50°C to 100°C) result in lubricant expulsion from green compacts, while maintaining good lubrication at the die walls at pressures >760 MPa (55 tsi), have been developed. As a result, PM parts with improved green density can be obtained. EXPERIMENTAL PROCEDURE The compaction and ejection characteristics of FC0205 and FC0208 powder mixes made with ATOMET 1001 atomized steel powder were characterized at different compaction temperatures. These two mixes contain 2 w/o Cu (ACuPowder 165) and 0.6 w/o and 0.8 w/o natural graphite (Southwestern 1651), respectively. These powder mixes were admixed with conventional ethylene bis-stearamide (EBS) lubricant, and with two proprietary lubricants coded Lube A and Lube B, which were developed for high-density applications. Lube A and Lube B have a similar chemical structure but with softening points of 60°C and 80°C, respectively. The compaction and ejection characteristics of the FC0208 powder mix were Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

evaluated on an instrumented laboratory singleaction press (Powder Testing Center (PTC)11). Cylindrical specimens with a height of 15 mm and an aspect ratio of 6.3 (4.5 times the aspect ratio of rectangular bars (TR bar: 31.75 mm × 12.7 mm × 6.35 mm), were pressed in a WC-Co die having a 9.525 mm dia., at a compacting speed of 1 mm/s. The PTC press permits continuous recording of the moving punch displacement, the forces applied to the moving punch and transmitted to the stationary punch, and the IN die density, during the entire compaction and ejection processes. This allows for the determination of the intrinsic compressibility, the sliding coefficient, and the ejection forces. The stripping pressure (which corresponds to the force needed to start the ejection process divided by the friction area) and the ejection unit energy were estimated from the ejection curve in order to compare the lubricating performance. The ejection unit energy is evaluated from the area under the ejection curve (force vs. displacement) divided by the displacement and the friction area. The lubricant losses during compaction and after ejection were also measured on the FC0208 powder mix. TR bars were compacted at 760 MPa at 65°C to green densities of 6.8 g/cm 3 , 7.0 g/cm3, and 7.3 g/cm3, using a floating die and a 100 st hydraulic press. The specimens were lightly polished to eliminate the lubricant on the sample surface and then sintered at 1,120°C for 30 min in dissociated ammonia to remove lubricant. Compact weights before and after sintering were measured. The behavior of the FC0205 powder mix was evaluated on an industrial 150 st Gasbarre mechanical press. Straight gears (15 teeth), 25.4 mm thick, with an aspect ratio of 4.7, were pressed in a CPM15V tool steel die preheated to a temperature of 70°C. The steady-state temperature of the parts was ~80°C. The compacting pressure was varied from 415 to 830 MPa (30 to 60 tsi). Compressibility curves were monitored and ejection forces were recorded. RESULTS AND DISCUSSION Effect of Temperature on Compressibility and Ejection Forces Figure 2 shows the effect of temperature on the green density of two FC0208 powder mixes, compacted on the PTC press, containing 0.75 w/o EBS and Lube A, respectively. At room tempera-

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Figure 2. Effect of temperature on the green density of FC0208 powder mixes, compacted at 760 MPa, containing 0.75 w/o EBS or Lube A

Figure 4. Intrinsic compressibility of FC0208 powder mixes, containing 0.75 w/o EBS or Lube A at 55°C

ture, the green density of the two powder mixes is similar. However, for compacting temperatures near and above the softening point of Lube A (60°C), the green density of the mix containing Lube A experiences a significant jump, while that of the other mix remains essentially constant. At a compacting pressure of 760 MPa (55 tsi) and a temperature of 65°C, the green density of the mix containing Lube A is approximately 0.2 g/cm3 higher than that of the mix containing the EBS lubricant, and about 99.1% of the pore-free density. As shown in Figures 3 to 5, this increase in green density can be related, in part, to the increase of the intrinsic compressibility and the decrease of the springback after ejection when the compacting temperature is near or above the soft-

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Figure 3. Intrinsic compressibility of FC0208 powder mixes, containing 0.75 w/o EBS or Lube A at room temperature

Figure 5. Effect of temperature on the axial springback of FC0208 powder mixes containing 0.75 w/o EBS or Lube A

ening point of Lube A. This significant increase in the intrinsic compressibility can be explained by the improvement in internal lubrication, and by the expulsion of a portion of the lubricant from the green compacts. In the compacting temperature range used in this study, the effect of temperature on the ductility of the metallic powders should have limited effect. Another factor explaining this green density increase is the behavior of the sliding coefficient as a function of the compacting temperature (Figures 6 and 7). The sliding coefficient of the mix containing Lube A is maintained, or even improved, at a compacting temperature near or above the softening point of Lube A. This is a major difference compared with the warm compaction of stearate/steel mixes near the Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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LUBRICANTS FOR HIGH-DENSITY COMPACTION AT MODERATE TEMPERATURES

Figure 6. Effect of applied pressure on the sliding coefficient of FC0208 powder mixes, containing 0.75 w/o EBS or Lube A, compacted at room temperature

Figure 7. Effect of applied pressure on the sliding coefficient of FC0208 powder mixes containing 0.75 w/o EBS or Lube A, compacted at 55°C

Figure 8. Effect of temperature on the stripping pressures of FC0208 powder mixes containing 0.75 w/o EBS or Lube A

Figure 9. Effect of temperature on the stripping pressures of FC0208 powder mixes containing 0.75 w/o EBS or Lube A

melting points of the stearate lubricants, in which a sharp decline in the sliding coefficient is observed. 9 The increase in green density with temperature observed in this study can be explained by the improvement of the intrinsic compactability, the decrease of the springback after ejection, and by the ability of the lubricant (Lube A) to maintain good lubrication at the die walls during compaction. Figures 8 and 9 show the variation of the stripping pressure and ejection energy, for the two powder mixes containing EBS and Lube A lubricants, with the compacting temperature. Again, in sharp contrast to warm compaction of stearate/ steel mixes,9 the ejection performances of the mix containing Lube A are maintained, even though Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

the compacting temperature is near to the softening point of Lube A. This property allows highdensity, high-aspect-ratio PM compacts fabricated without damaging the tooling dies. Effect of Temperature on Lubricant Loss During Compaction Figure 10 shows that no lubricant was expelled from the powder compacts pressed from the mix containing the EBS lubricant. Similar behavior was recorded for the mix containing Lube A for green densities 12.7 mm. Figure 11 shows the compressibility of the two powder mixes. At 830 MPa (60 tsi), the green densities of the mixes containing Lube B and EBS were 7.3 g/cm3 and 7.23 g/cm3, respectively, or 97.7% and 96.6%, respectively, of the pore-free density. It must be emphasized that the surface of friction of the gear compacted with Lube B (6,452 mm2) was twice as high as that for a gear made using the EBS lubricant. As shown in Figure 12, the ejection performances of the mix containing Lube B were still better than those of the mix containing the EBS lubricant. CONCLUSIONS Lubricant systems designed for pressing at moderate temperature (100. To avoid ambiguity, in the following discussion, both “molding” and “moulding” were used to form composite searches, with corrections for those publications that used both terms. Searches of patent databases and publications revealed that the search terms must be properly selected to identify relevant articles. For example, “powder” + “molding” generated 46,414 patent citations, far in excess of the expected number. As listed in Table I, the most significant search term was “powder injection molding.” More than 40 search word combinations were tested and many proved to be fruitless. The highest frequency of valid citations in patent and publication searches

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TABLE I. PHRASES AND KEYWORDS ASSOCIATED WITH PIM R&D, RANKED BY IMPACT FACTOR (INCLUDES MOLDING AND MOULDING) Phrase “Powder injection molding” “Ceramic injection molding” “Metal injection molding” “Debinding” “Metal powder injection molding” “Debind” “Carbide injection molding” “Debound”

h-Factor 33 25 16 11 8 5 2 2

resulted from word combinations such as “binder” + “powder injection molding” and variants on the first word such as “metal,” “ceramic,” or “carbide.” Searches based on the term “metal injection molding” produced 1,810 publications, but about 30% were on thixomolding, metal tooling for injection molding, rapid prototyping, bonded magnets, and other topics. Searches using “MIM” gave 89,900 publications, many of which were associated with tumors, linguistics, immunodeficiency, and other distant concepts. Thus, use of “powder injection molding” or “metal powder injection molding” was the most fruitful. Table I lists the most significant search terms based on impact factors. At the end of 2006, the estimated PIM publication count was 3,120 and the estimated U.S. Patent count was about 400. However, probably only 83 patents were specific to PIM technology in the past 20 years. Unpublished conference papers were included in the tabulation, including 744 presentations where handouts were distributed in lieu of proceedings. Besides presentations, patents, and publications, 175 senior researchers were identified via various databases and publications. They were contacted and asked to respond to a brief survey on past, current, and future activities. About 10% of the respondents said they had discontinued R&D efforts in PIM. About 20% had moved, retired, were no longer living, found new employment, or were otherwise no longer involved in PIM. Over 30% provided full data and a few provided only partial data; thus, the survey achieved more than a 60% response, with half of the responses in the form of full participation. SCALE OF PIM R&D Early in a new technology statistics from the product life-cycle analysis show upwards of 10% Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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R&D IN SUPPORT OF POWDER INJECTION MOLDING: STATUS AND PROJECTIONS

Figure 1. Product life cycle in terms of sales with overlaid plot of appropriate R&D investment. Typically, when a technology is young, sales are small but up to 10% of sales are invested in R&D, usually for product development. As sales finally grow, the total R&D commitment peaks at the sales inflection point, usually averaging about 5% of sales. When the peak in sales is approached, the focus is on R&D for process improvements and cost reductions. Here the R&D investment drops to 1% of sales. When sales go into a prolonged decline, then R&D investment falls below 0.5% of sales

of sales devoted to R&D. As sales grow, a typical R&D investment strategy is shown in Figure 1. The absolute peak in R&D investment is at the inflection point in sales. Since products are at many different stages on the product life-cycle curve, in the U.S. the overall industrial R&D investment averages 2.7% of sales, but it is smaller at 2.3% globally.3 There are several ways to capture the total R&D investment in PIM. From various studies,4–33 the cumulative global sales for PIM since inception passed $8.7 billion in 2006. Profits are more difficult to assess, but the same sources suggest that up to 1991, the total loss for PIM was about $45 million, while the profit during the 1990s was upwards of $500 million (before interest and taxes). With reduced business and increased competition in recent years, cumulative profit from 2000 to 2006 is calculated at $100 million. For these estimates, an inflation of 5% was assumed. These and other data provide the following parameters for PIM R&D investment to date: Sales: Based on cumulative industry sales since inception to 2006 of $8.7 billion and an average investment of 2.5% of sales in R&D, with leveraging (10% industry R&D on average allocated to academe or government laboratories, which then leverage this by a factor of five), the total is Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

$326 million, with a probable error of $35 million. Profits: Based on cumulative estimated profits from PIM of $555 million, a typical allocation of 40% of profits to R&D, and with the government, academic, and foundation leveraging levels cited for sales, the total R&D investment is $330 million, with an error of $50 million. Publications: Based on 3,120 published papers (~45% in journals, 45% in conference proceedings, and 10% in magazines), a journal article on average results from $150,000 in R&D expenses, a conference publication results from $50,000, and a magazine article results from $20,000. This gives a total value of $287 million, with an estimated error of $45 million. Patents: Global patent activity is focused on the U.S. which accounts for nearly 200,000 new patents per year at an average R&D cost of $5 million per patent in industry and $43 million per patent in academe. Although 400 patents were identified, 25% were issued prior to the emergence of a PIM industry (early ceramic molding ideas), and about half of the remaining patents relate to bonded magnets, filled polymers, and related peripheral fields. This leaves 83 patents (mostly industrial) that are clearly the result of PIM R&D, for an investment of $415 million, but with a large error of $200 million. Researchers: Based on an average of 255 researchers over the past 20 years (the peak was 325 in 1996), with about 65% employed at universities, with a current expenditure per investigator of $200,000 per year in industry in the U.S. and $125,000 per year in academe, and with discounts for lower-cost portions of the world (further realizing that many investigators are not full time on PIM; for example, graduate students are only half time), gives a $428 million cumulative investment with an error of $200 million. The large error arises because costs at sites such as China, Korea, and India are not well documented. Capital Expense: It is recognized that industry invests on average 10.3% of sales in combined capital expense and R&D. Since previous reports on cumulative capital expense are published, the residual can be assigned to PIM R&D activities, giving $276 million, with an error ~$100 million. These five approaches are combined in Table II, giving an estimate of the cumulative PIM R&D investment at about $344 million, a standard deviation of $64 million, but with a realistic error of $105 million.

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R&D IN SUPPORT OF POWDER INJECTION MOLDING: STATUS AND PROJECTIONS

TABLE II. ESTIMATES OF GLOBAL R&D INVESTMENT IN PIM Basis Cumulative industry sales Cumulative industry profits Cumulative publications Patent activity Research personnel Capital expense

PIM R&D ($ million)

Error ($ million)

326 330 287 415 428 276

35 50 45 200 200 100

TABLE III. SOME SUMMARY STATISTICS ON PIM AND PIM R&D Measure

$ Million

Cumulative global PIM industry sales Cumulative global PIM industry profits Cumulative global PIM industry capital investment Cumulative global PIM R&D expenditures (all sources) Cumulative global PIM industry R&D expenditure Cumulative global PIM expenditures (academe, government laboratories & independent research centers)

8,700 555 620 344 230 114

As summarized in Table III, of the cumulative R&D investment in PIM, industry has provided about $230 million, the balance being derived from government, academe, and foundation sources. A good example of leveraging was the development of an aqueous binder system for PIM that was 50% subsidized over 15 years by several government programs. METRICS OF R&D GROWTH Knowledge is a critical factor in relation to commercial progress in a technical field. To assess the situation in PIM, the global publication database was assessed. Over 2,800 of the 3,120 publications were collected and categorized. The resulting partition, based on subject, materials, sources, topics, and other attributes, provides a clear indication of the situation in PIM. Geography The geographic trends in PIM R&D help predict locations for future activity concentration. In this study, the distribution was based on where the research was performed. If an investigator performed the study while in another country, then the host country is credited. In terms of publications, the U.S. is the largest with nearly 46% of the publications, followed by Japan with 14%. Third ranking goes to Germany with 9%, followed by the U.K., China, Taiwan, and Korea. Additional research publications were identified from

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Figure 2. Geographic distribution (%) of publications on PIM R&D

Australia, Austria, Belgium, Brazil, Canada, Columbia, the Czech Republic, Denmark, Egypt, Finland, France, India, Iran, Ireland, Israel, Italy, Latvia, Malaysia, Norway, Portugal, Romania, Russia, Singapore, Slovenia, South Africa, Spain, Sweden, Switzerland, Thailand, Turkey, and the Ukraine. In total, these countries account for only 16% of the total. Figure 2 illustrates the geographic information in the form of a pie chart grouped as Asia, Europe, and North America. The remaining large geographic regions of Africa, Australia, the Middle East, and South America constitute 646°C (based on DSC measurements) or 642°C (based on Thermo-Calc43 calculations performed with the COST 507 database44–46). Since general melting is not of interest during sintering, a description of the microstructural progress between 550°C and the sintering temperature is necessary in order to understand how the final microstructure of the alloy evolves. Figure 4 shows another important endothermic reaction at ~549°C; this reaction corresponds to:1 Al + CuAl2 → Liq. (548ºC)

(4)

This reaction occurs at locations where the copVolume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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per particles far removed from the magnesium particles did not interfere with reactions (1) to (3) due to insufficient concentration of magnesium. This reaction does not appear to result in swelling of the compact, since the amount of liquid present in the system is sufficient to produce shrinkage by normal liquid-phase sintering (LPS) mecha-

nisms. Figure 6 confirms this effect in the form of a change of slope in the dilatometer trace at ~540°C–555°C. At this stage, chemical homogenization of the alloy may be monitored in terms of the microstructures corresponding to specimens quenched from 570°C and 590°C. As observed in Figure 11(a), essentially all the

Figure 10. Representative microstructure showing microstructural evolution of Al-12 w/o Si particles while heating in nitrogen atmosphere to the sintering temperature. OM. (a) green compact, (b) after debinding for 20 min at 410°C, (c) quenched in water from 475°C after heating at 2°C/min, and (d) quenched in water from 525°C after heating at 2°C/min

Figure 11. Representative microstructure corresponding to samples quenched in water after heating at 2°C/min in nitrogen atmosphere. (a) 570°C and (b) 590°C. SEM backscattered images

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copper in the alloy has been incorporated in the microstructure, according to reaction (4), to form permanent aluminum/copper liquid which also contains small amounts of magnesium and silicon. This liquid appears to surround the aluminum grains after quenching. At this point compositional gradients have been smoothed out and the constitution of the alloy is nearing equilibrium. It is noted that intragranular CuAl2 precipitates may also form upon rapid cooling. At 590°C the microstructure contains the same constituents, but with an increasing volume of liquid as the temperature is increased, Figure 11(b). A higher heating rate to 590°C (from 2°C/min to 10°C/min) results in slower homogenization of the alloy, as observed in Figure 12. The cited reactions still take place at the same temperatures but the liquids formed have less time to spread. Also, the alloying elements have less time to diffuse into the aluminum and, in these microstructures, copper is not distributed homogeneously under these conditions (Figure 12). Some of the copper particles are either unaltered or tend to form a liquid (Figure 13). The behavior of this alloy following a conventional sintering cycle under varying conditions of temperature, time, and atmosphere was reported previously.47 Under a nitrogen atmosphere, an optimal combination of sintered density and hardness (2.59 g/cm3 (93% pore-free density) and 60 HRF) was obtained at 590°C for 20 min. Raising the sintering temperature to >590°C led to a small increase in density, but without any increase in hardness, due to grain growth. In contrast, sinter-

Figure 12. Representative microstructure of sample quenched in water from 590°C after heating at 10°C/min in nitrogen atmosphere. SEM backscattered image. EDS analyses on marked spots: (a) ~92 w/o Al-2 w/o Cu-4 w/o Mg-2 w/o Si, and (b) ~100 w/o AL

66

ing at 590°C under vacuum resulted in a density of 2.66 g/cm3 (95.7% pore-free density) and a hardness of 69 HRF. This constitutes an attractive improvement in both properties in the as-sintered state. The improvement in sintered density is attributed to the prevention of gas entrapment from the sintering atmosphere.48–49 As a further exploration of the effect of the sintering schedule and atmosphere on properties, the sintering regime illustrated in Figure 1 was utilized. This cycle represents an attempt to minimize distortion of the samples during sintering, assuming the distortion to be associated with the manner in which the liquid appears and spreads between the aluminum particles. Under these conditions, a sintering cycle with a slow heating rate and various holding steps should allow for uniform spreading of the liquid, and hence result in a uniform densification of the sample. The first step is carried out under vacuum in order to prevent gas entrapping in the pores.48–49 Table II presents a summary of the sintered density and hardness values as a function of sintering temperature at the upper holding step (T s ) in Figure 1. It is observed that the final sintered density is the same in all cases, but the hardness drops significantly at 630°C, due to grain growth.47 A set of tensile specimens with a green density of 2.61 ± 0.02 g/cm3 (93.9 ± 0.7% pore-free density) were sintered following this cycle at a temperature Ts of 590°C. After sintering, these samples exhibited a density of 2.745 ± 0.006 g/cm3 (98.7 ± 0.2% pore-free density). Some of these specimens were heat treated to the T4 or T6 condition. The effects of this additional heat treatment on tensile properties are summarized in Table III. These

Figure 13. Representative microstructure of sample quenched in water from 590°C after heating at 10°C/min in nitrogen atmosphere. SEM backscattered image

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property levels are considerably higher than those reported in the technical literature for this alloy14,16,30–31 and are comparable with recently reported values obtained after introducing slight modifications in chemical composition.34 A set of components pressed under industrial conditions (Figure 14) were sintered following the TABLE II. AS-SINTERED DENSITY AND HARDNESS AS A FUNCTION OF SINTERING TEMPERATURE (SINTERING CYCLE IN FIGURE 1) Ts (°C) 590 610 630

Sintered Density (g/cm3) Pore-Free Density (%) 2.72 ± 0.02 2.71 ± 0.02 2.717 ± 0.008

97.8 ± 0.6 97.5 ± 0.6 97.7 ± 0.3

HRF 73.9 ± 8.6 70.0 ± 12.4 59.8 ± 13.5

TABLE III. TENSILE PROPERTIES,YOUNG’S MODULUS AND HARDNESS OF ALLOYS SINTERED AT 590°C (SINTERING CYCLE IN FIGURE 1) Condition As-sintered T4 T6

UTS 0.2% Offset Yield (MPa) (MPa) 225 ± 20 318 ± 11 388 ± 26

152 ± 4 231 ± 6 370 ± 13

Elongation (%)

E (GPa)

HRF

2.9 ± 1.2 4.5 ± 0.6 0.26/0.73

61 ± 18 69 ± 3 71 ± 10

80 ± 4 92 ± 4 97 ± 4

cycle shown in Figure 1. The components were pressed to a green density of 2.52 g/cm3 (90.5% pore-free density) with a uniform external dia. 26.30 ± 0.02 mm from top to bottom. After sintering at 590°C for 20 min, the density increased to 2.66 g/cm3 (95.6% pore-free density) with an assintered hardness of 73 ± 5 HRF. Although the components exhibited a uniform contraction pattern, the as-sintered top and bottom diameter differed from 25.89 ± 0.14 to 25.97 ± 0.12 mm, respectively. These differences could be corrected after a sizing operation that also contributed to a slight increase in the surface hardness, and an improved surface finish. Figure 15 shows a representative microstructure of these components after sintering. As expected,1 and after verification by XRD (Figure 16), the intergranular phase is primarily CuAl2.

Figure 15. Representative microstructure of components in as-sintered state. SEM backscattered image

Figure 14. Component for shock absorbers: green (left) and as-sintered (right)

Figure 16. XRD trace of as-sintered alloy

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

Figure 17. Representative microstructure of components in T4 condition. EDS spot analyses on arrowed particles revealed the presence of iron. SEM backscattered image

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Figure 17 shows the microstructure of the components in the T4 condition. The microstructure consists of an aluminum solid solution and a dispersion of CuAl2 that formed during cooling, or which did not dissolve completely during the solution treatment. Additionally, EDS analyses revealed the presence of a few iron-containing particles which confir ms that the impurity observed in the interdendritic spaces within the original aluminum particles (Figure 3(c)) is iron. Upon sintering, the iron segregates to the liquid phase, forming an intermetallic phase which cannot be dissolved during the solution treatment. This iron-containing phase is present in the assintered compact, but the presence of CuAl2 tends to mask its identification in Figure 15. The presence of this type of particle is unavoidable and limits the final ductility of the alloy. CONCLUSIONS 1. When heating to the sintering temperature, several transient liquids form as a result of reactions between the elemental aluminum, elemental copper, Al-50 w/o Mg, and Al-12 w/o Si particles. 2. Concurrent with the generation and spreading of these transient liquids, alloying elements diffuse to the aluminum particles, leading to the formation of the alloy. 3. Spreading of the transient liquids, and chemical homogenization, result in swelling of the powder compact and the generation of porosity. 4. A permanent liquid (that promotes densification of the alloy by conventional liquid-phase sintering mechanisms) appears in the system at temperatures ≥590°C when alloying is complete. 5. A complex sintering cycle with a slow heating rate after dewaxing (2°C/min), a first holding step for 20 min at 570°C in vacuum, and a second holding step at 590°C for 20 min in nitrogen minimizes distortion and improves density. 6. Samples sintered via this cycle attain a density of 98% of the pore-free density and exhibit attractive mechanical properties in the as-sintered, T4, and T6 conditions. ACKNOWLEDGEMENT The authors gratefully acknowledge the Departamento de Educación, Universidades e Investigación of the Basque Government for financial support of this work. Special thanks are due Polmetasa, Sinterstahl Group, for their collaboration in fabricating the shock absorber components.

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REFERENCES 1. L.F. Mondolfo, Aluminum Alloys: Structure and Properties, 1976, Butterworth & Co. Ltd., London, UK. 2. Aluminum and Aluminum Alloys, ASM Specialty Handbook, edited by J.R. Davis, 1993, ASM International, Materials Park, OH. 3. E.J. Lavernia, J.D. Ayers and T.S. Srivatsan, “Rapid Solidification Processing with Specific Application to Aluminum Alloys”, Int. Mater. Rev., 1992, vol. 37, no. 1, pp. 1–44. 4. A. Greasley and H.Y. Shi, “Microstructural Development during Hot Working of Powdered Aluminum Alloy”, Powder Metall., 1993, vol. 36, no. 4, pp. 288–292. 5. Z. Ishijima, H. Shikata, H. Urata and S. Kawase, “Development of P/M Forged Al-Si Alloy for Connecting Rod”, Advances in Powder Metallurgy and Particulate Materials, compiled by T.M. Cadle and K.S. Narasimhan, Metal Powder Industries Federation, Princeton, NJ, 1996, vol. 4, part 14, pp. 3–14. 6. J.R. Pickens, “Aluminum Powder Metallurgy Technology for High-Strength Applications”, J. Mater. Sci., 1981, vol. 16, pp. 1,437–1,457. 7. M. Hull, “AMC: Leading Edge MMCs and Powder Materials”, Powder Metall., 1997, vol. 40, no. 2, pp. 102–103. 8. M.J. Couper, M. Nauer, R. Baumann and R.F. Singer, ”On the Break-Up and Redistribution of Oxides Following Powder Degassing and Consolidation of Elevated Temperature PM Aluminum Alloys”, Proc. International Conference on PM Aerospace Materials, MPR Publishing Services Ltd., Shrewsbury, England, 1988, paper 28, pp. 1–11. 9. A.D. Jatkar and R.R. Sawtell, “Aluminum PM Alloys for Aerospace Applications”, Proc. of International Conference on PM Aerospace Materials, MPR Publishing Services Ltd., Shrewsbury, England, 1992, paper 15, pp. 1–14. 10. F.V. Beaumont, “Aluminum P/M: Past, Present and Future”, Int. J. Powder Metall., 2000, vol. 36, no. 6, pp. 41–43. 11. P.S. Gilman, “Light High Temperature Aluminum Alloys for Aerospace Applications”, Proc. International Conference on PM Aerospace Materials, ibid. reference no. 9, paper 16, pp. 1–11. 12. “Part Winners Represent New Markets for PM”, Metal Powder Report, 1998, vol. 53, no. 7/8, pp. 12–15. 13. G.B. Schaffer and S.H. Huo, “High Strength Aluminum Alloys”, ibid. reference no. 5, vol. 4, part 14, pp. 27–39. 14. W.J. Ullrich, "Practical Considerations for Fabricating Aluminum P/M Parts", Progress in Powder Metallurgy, Metal Powder Industries Federation, Princeton, NJ, 1986, vol. 42, pp. 535–556. 15. G. Jangg, H. Danninger, K. Schröder, K. Abhari, H.C. Neubing and J. Seyrkammer, “PM Aluminum Camshaft Belt Pulleys for Automotive engines”, Mat.-wiss., u. Werkstofftech, 1996, vol. 27, pp. 179–189. 16. W.J. Huppmann, H. Kirschsieper, W. Häde and G. Schlieper, “Sintered Aluminum Parts for Automotive Applications”, Proc. 7th International Conference on Light Metals, Ver Metallwerke Ranshofen-Berndorf, BraunauRanshofen, Austria, 1981, pp. 236–237. 17. D. Apelian and D. Saha, “Aluminum P/M Processed Components—Challenges and Opportunities”, Proc. Second International Conference on Powder Metallurgy Aluminum and Light Alloys for Automotive Applications, edited by R.A. Chernenkoff and W. F. Jandeska, Jr., Metal

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Powder Industries Federation, Princeton, NJ, pp. 1–10. 18. P. Delarbre and M. Krehl, “Applications of P/M Aluminum Parts—Materials and Processing Schemes”, ibid. reference no. 17, pp. 33–39. 19. R.N. Lumley and G.B. Schaffer, “The Effect of Solubility and Particle Size on Liquid Phase Sintering”, Scripta Materialia, 1996, vol. 35, no. 5, pp. 589–595. 20. R.N. Lumley and G.B. Schaffer, “The Effect of Additive Particle Size on the Mechanical Properties of Sintered Aluminum-Copper Alloys”, Scripta Materialia, 1998, vol. 39, no. 8, pp. 1,089–1,094. 21. T. Wantanabe and K. Yamada, “Effects of Methods of Adding Copper on the Strength of Sintered Aluminum Copper Alloys”, Int. J. Powder Metall., 1968, vol. 4, no. 3, pp. 37–47. 22. H. Danninger, H.C. Neubing and J. Gradl, “Sintering of High Strength Al-Zn-Mg-Cu Alloys to Controlled Dimensions”, Proc. 1998 Powder Metallurgy World Congress and Exhibition, European Powder Metallurgy Association, Shrewsbury, UK, 1998, vol. 5, pp. 272–277. 23. R.N. Lumley, T.B. Sercombe and G.B. Schaffer, “Surface Oxide and the Role of Magnesium during the Sintering of Aluminum”, Metallurgical and Materials Transactions A, 1999, vol. 30A, pp. 457–463. 24. G.B. Schaffer and B.J. Hall, “Sintering of Aluminum in Argon and Nitrogen”, Advances in Powder Metallurgy and Particulate Materials, edited by V. Arnhold, C.L. Chu, W.F. Jandeska, Jr. and H.I. Sanderow, Metal Powder Industries Federation, Princeton, NJ, 2002, part 13, pp. 139–149. 25. I.A. Shibli and D.E. Davies, “Effect of Oxidation on Sintering Characteristics of Al Powder and Effect of some Minor Metallic Additions”, Powder Metall., 1987, vol. 30, no. 2, pp. 97–102. 26. W. Kehl and H. Fischmeister, “Observations on Dimensional Changes during Sintering of Al-Cu Compacts”, Sintering—Theory and Practice, Proc.5th International Round Table Conference on Sintering, edited by D. Kolar, S. Pejovnik and M.M. Ristic, Material Science Monographs, 1982, vol. 14, pp. 269–274. 27. A.P. Savitskii, G.N. Romanov and L.S. Martsunova, “Optimization of the Process from the Standpoint of the New Theory of Liquid Phase Sintering”, Proc.1997 European Conference on Advances in Structural PM Component Production, European Powder Metallurgy Association, Shrewsbury, UK, pp. 150–156. 28. F.F. Nia and B.L. Davies, “Production of Al-Cu and Al-CuSi Alloys by PM Methods”, Powder Metall., 1982, vol. 25, no. 4, pp. 209–215. 29. J.M. Martín, B. Navarcorena, I. Arribas, T. Gómez-Acebo and F. Castro, “Dimensional Changes and Secondary Porosity in Liquid Phase Sintered Al Alloys”, Proc. Powder Metallurgy World Congress and Exhibition (PM2004), edited by H. Danninger and R. Ratzi, EPMA Shrewsbury, UK, 2004, vol. 4, pp. 45–52. 30. H.C. Neubing and G. Jangg, “Sintering of Aluminum Parts: The State-of-the-Art”, Metal Powder Report, 1987, vol. 42, no. 5, pp. 354–358. 31. J.H. Dudas and C.B. Thompson, “Improved Sintering Procedures for Aluminum P/M Parts”, Moder n Developments in Powder Metallurgy, edited by H.H. Hausner, New York, Plenum Press, 1971, vol. 5, pp. 19–36. 32. M. Mühlburger and P. Paschen, “Flüssigphasensintern von AlZnMgCu-Legierungen”, Z. Metallkd., 1993, vol. 84, no. 5, pp. 346–350.

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33. E.M. Daver, W.J. Ullrich and K.B. Patel, “Aluminum P/M Parts—Materials, Production and Properties”, Key Engineering Materials, 1989, vol. 29-31, pp. 401–428. 34. T.B. Sercombe and G.B. Schaffer, “On the Use of Trace Additions of Sn to Enhance Sintered 2xxx Series Al Powder Alloy”, Mater. Sci. Eng. A, 1999, vol. A268, pp. 32–39. 35. H.C. Neubing, J. Gradl and H. Danninger, “Sintering and Microstructure of Al-Si P/M Components”, ibid. reference no. 24, part 13, pp. 128–138. 36. J.M. Martín, T. Gómez-Acebo and F. Castro, “Sintering Behaviour and Mechanical Properties of PM Al-Zn-Mg-Cu Alloy Containing Elemental Mg Additions”, Powder Metall., 2002, vol. 45, no. 2, pp. 173–180. 37. G.B. Schaffer and S.H. Huo, “On Development of Sintered 7xxx Series Aluminum Alloys”, Powder Metall., 1999, vol. 42, no. 3, pp. 219–226. 38. G.B. Schaffer, B.J. Hall, S.J. Bonner, S.H. Huo and T.B. Sercombe, “The Effect of the Atmosphere and the Role of Pore Filling on the Sintering of Aluminum”, Acta Materialia, 2006, vol. 54, no. 1, pp. 131–138. 39. W. Kehl and H.F. Fischmeister, “Liquid Phase Sintering of Al-Cu Compacts”, Powder Metall., 1980, vol. 23, no. 3, pp. 113–119. 40. “MPIF Standard No. 10, Preparing and Evaluating Tensile Specimens of Powder Metallurgy Materials”, Standard Test Methods for Metal Powders and Powder Metallurgy Products, Metal Powder Industries Federation, Princeton, New Jersey, USA, 1998. 41. A.P. Savitskii: Liquid Phase Sintering of the Systems with Interacting Components, 1993, Russian Academy of Sciences, Tomsk. 42. Diffusion in Solid Metals and Alloys, edited by H. Mehrer, Landolt-Börnstein, Numerical Data and Functional Relationships in Science and Technology, New Series, Group III, vol. 26, 1990, Springer-Verlag, Germany. 43. B. Sundman, B. Jansson and J.-O. Andersson, “The Thermo-Calc Databank System”, Calphad, 1985, vol. 9, no. 2, pp. 153–190. 44. “COST 507, Definition of Thermochemical and Thermophysical Properties to Provide a Database for the Development of New Light Alloys”, Proc. Final Workshop, edited by COST Secretariat, European Communities, Brussels, Belgium, 1998, vol. 1. 45. “COST 507, Definition of Thermochemical and Thermophysical Properties to Provide a Database for the Development of New Light Alloys, Thermochemical Database for Light Metal Alloys”, edited by I. Ansara, A.T. Dinsdale and M.H. Rand, European Communities, Brussels, Belgium, 1998, vol. 2. 46. “COST 507, Definition of Ther mochemical and Thermophysical Properties to Provide a Database for the Development of New Light Alloys, Critical Evaluation of Ternary Systems”, edited by G. Effenberg, European Communities, Brussels, Belgium, 1998, vol. 3. 47. J.M. Martín and F. Castro, “Liquid Phase Sintering of P/M Aluminum Alloys: Effect of Processing Conditions”, Journal of Materials Processing Technology, 2003, vol. 143–144, pp. 814–821. 48. R.M. German, Liquid Phase Sintering, 1985, Plenum Press, New York, USA. 49. H.H. Park, S.J. Cho and D.N. Yoon, “Pore Filling Process in Liquid Phase Sintering”, Metall. Trans. A, 1984, vol. 15A, pp. 1,075–1,080. ijpm

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NEW MPIF STANDARD 35, MATERIALS STANDARDS FOR PM STRUCTURAL PARTS 2007 EDITION

The most comprehensively revised Standard in almost 15 years, the new Standard 35, Materials Standards for PM Structural Parts—2007 Edition has just been published. Order enough for your own company use and for free distribution to your existing and potential customers. Keep a supply handy for future trade shows, plant visits, etc. Make sure that your quality assurance/laboratory staff and your sales and marketing personnel/representatives have the latest edition of this standard. Please note that publication of the 2007 Edition of this standard renders the 2003 Edition (and prior editions) obsolete. Previous editions should no longer be distributed but destroyed. The 2007 Edition contains: • Guidelines for specifying a PM Part • New and revised verbiage/data throughout the standard • Alphabetical index listing & guide to materials/designation codes in the family of MPIF Standard 35 publications • New information, revisions and/or re-designation of several material codes, chemical compositions and property data in the standard • 11 new materials, chemical compositions and mechanical property data • New—Steam Oxidation of Ferrous PM Materials • New material sections in the standard This standard is a must-have document for every engineering professional.

Price Item # 1026 Softcover Item # 1026cd CD-ROM Item # 1026e Electronic (pdf)

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For Quantity Discounts, Please Contact the MPIF Publications Department To Order: FAX:609-987-8523, Phone: 609-945-0009, E-mail: [email protected] or visit www.mpif.org METAL POWDER INDUSTRIES FEDERATION 105 College Road East, Princeton, NJ 08549-6692

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MEETINGS AND CONFERENCES

2007 5TH INTERNATIONAL CONFERENCE ON MATERIALS PROCESSING FOR PROPERTIES AND PERFORMANCE December 11–15 Singapore www.iommp3.org

2008 AUTOUKRAINE 2008 January 29 Kiev, Ukraine www.wbr.co.uk/autoukraine PM08 INTERNATIONAL CONFERENCE & EXHIBITION February 20–21 Chennai, India www.pmai.in/pm08 PIM2008 March 10–12 Long Beach, CA MPIF* SAE WORLD CONGRESS & EXPOSITION April 14–17 Detroit, MI www.sae.org HIP ’08—THE 9TH INTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING May 6–9 Huntington Beach, CA www.hip2008.com 2008 WORLD CONGRESS ON POWDER METALLURGY & PARTICULATE MATERIALS June 8–12 Gaylord National Hotel Washington, DC MPIF*

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2008 INTERNATIONAL CONFERENCE ON TUNGSTEN, REFRACTORY & HARDMATERIALS VII June 8–12 Gaylord National Hotel Washington, DC MPIF* BASIC PM SHORT COURSE July 21–23 State College, PA MPIF* PM SINTERING SEMINAR September TBA MPIF* SUPERALLOYS 2008 September 14–18 Champion, PA www.tms.org/Meetings/specialty/ superalloys2008/home.html

2009 POWDERMET2009: MPIF/APMI INTERNATIONAL CONFERENCE ON POWDER METALLURGY & PARTICULATE MATERIALS June 28–July 1 Las Vegas, NV MPIF*

2010 PM2010 WORLD CONGRESS October 10–14 Florence, Italy

INTERNATIONAL CONFERENCE ON ALUMINUM ALLOYS September 22–26 Aachen, Germany www.dgm.de 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

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INSTRUCTIONS FOR AUTHORS International Journal of Powder Metallurgy Instructions for Authors The Journal reports on scientific and technological developments worldwide in the powder metallurgy and particulate materials industries. Articles cover both the scientific/theoretical and practical aspects of the technology. Subjects addressed include: powder production and characterization; compaction; sintering; consolidation to full density; powder injection molding; consolidation to full density; and hybrid particulate processes such as spray forming and thermal spraying. The Journal also embraces review articles, PM industry news, company profiles, a consultants’ corner, newsmakers, conference reports and book reviews. The Journal’s audience includes: powder metallurgists, engineers, researchers, educators, students, technical managers, and users of powders, PM parts and particulate materials. Manuscript Requirements 1. The primary author should be a member of APMI International. 2. a. All manuscripts must be typewritten, double spaced and on one side of the paper only. Authors should limit manuscripts to 10 printed pages in the Journal—including text, references, figures and tables. For guidance, this is roughly 30 double-spaced pages—including text, references, figures and tables. b. Three copies of the manuscript are required. Each should contain original line drawings, photographs and/or micrographs mounted and labeled. Alternatively, digital images will be accepted provided they are in jpg or tif format (at least 4x6 inches at 300 dpi). c. Authors must submit the text portion of their manuscript on disk/CD in Microsoft Word or ASCII format, in addition to the hard copies of the manuscript. Digital images must be in separate files. d. Micrographs must include a magnification marker in the lower right-hand corner. e. Tables and figures must include complete descriptive captions. f. Equations, tables, references and figures should be numbered separately and consecutively throughout the text. g. Papers must be in English, be original and not be published elsewhere. Translated papers published in other languages will be considered provided the author receives permission and submits a copyright release from the publication involved. Particular attention should be given to grammar/syntax; the Journal is not in a position to assist foreign authors in technical writing. 3. Authors and co-authors must provide complete Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

names, mailing addresses, job titles and affiliations, as they wish them to appear in the Journal. A letter accompanying the manuscript should give the name, complete address, telephone number, fax number and e-mail address of the author to whom correspondence should be sent. 4. Each paper must include an abstract of approximately 100 words that summarizes concisely the paper’s objectives, methods, results, observations, mode of analysis and conclusions. 5. Système International (SI) units are mandatory. If industrial practice dictates the use of other systems of units, such units must be included in parentheses. As a guide for authors, frequently used SI units and the corresponding conversion factors are provided overleaf. 6. Weight percent, atomic percent and volume percent should be given as w/o, a/o and v/o, respectively. 7. References must be numbered, placed at the end of the paper, and must adhere to the following format: Journal T. Le, R. Stefaniuk, H. Henein and J-Y. Huôt, “Measurement and Analysis of Melt Flowrate in Gas Atomization”, Int. J. Powder Metall., 1999, vol. 35, no. 1, pp. 51–60. Book R.M. German, Powder Metallurgy Science, Second Edition, 1994, Metal Powder Industries Federation, Princeton, NJ. Article in Book/Conference Proceedings S.H. Luk, F.Y. Chau and V. Kuzmicz, “Higher Green Strength and Improved Density by Conventional Compaction”, Advances in Powder Metallurgy & Particulate Materials, compiled by J.J. Oakes and J.H. Reinshagen, Metal Powder Industries Federation, Princeton, NJ, 1998, vol. 3, part 11, pp. 81–99. Patent I.L. Kamel, A. Lawley and M-H. Kim, “Method of Molding Metal Particles”, U.S. Patent No. 5,328,657, July 12, 1994. Thesis D.J. Schaeffler, “High-Strength Low-Carbon Powder Metallurgy Steels: Alloy Development with Transition Metal Additions”, 1991, Ph.D. Thesis, Drexel University, Philadelphia, PA. Technical Report T.M. Cimino, A.H. Graham and T.F. Murphy, “The Effect of Microstructure and Pore Morphology on Mechanical and Dynamic Properties of Ferrous P/M Materials”, 1998, Hoeganaes Technical

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INSTRUCTIONS FOR AUTHORS

Data, Hoeganaes Corporation, Cinnaminson, NJ. Web Site Content J.R. Dale, “Connecting Rod Evaluation”, Metal Powder Industries Federation, http://www.mpif. org/design/conrod.pdf Private Communication P.W. Taubenblat, 1999, Promet Associates, Highland Park, NJ, private communication. The author(s) will be sent a copyright form, which must be returned before the paper can be published. A reprint order form will also be sent to the author(s). All manuscripts submitted to the Journal should be sent to the Editor-in-Chief, who will make an initial

decision on the paper’s suitability for external review. Papers are then subject to review by two members of the Editorial Review Committee. Papers are accepted with the understanding that they may be returned to the author(s) for revision, based on the reviewer’s recommendations. They may also be edited by the Journal’s staff for clarity and conciseness. Articles should be submitted to: Dr. Alan Lawley Editor-in-Chief International Journal of Powder Metallurgy 105 College Road East Princeton, NJ 08540-6692 USA

SYSTÈME INTERNATIONAL UNITS (SI) AND CONVERSION FACTORS Source: R.M. German, Powder Metallurgy Science, Second Edition, Metal Powder Industries Federation, Princeton, NJ 1994 Length Conversions: 1 m = 39.4 in. (inch) 1 m = 3.28 ft. (foot) 1 m = 1.09 yd. (yard) 1 cm = 0.394 in. (inch) 1 mm = 0.0394 in. (inch) 1 µm = 39.4 µin (microinch) 1 nm = 10 Å (angstrom) Area and Volume Conversions: 1 cm2 = 0.155 in.2 (square inch) 1 m2 = 1,550 in.2 (square inch) 1 cm3 = 0.061 in.3 (cubic inch) 1 m3 = 35 ft.3 (cubic foot) 1 L = 1,000 cm3 (cubic centimeter) 1 L = 0.264 gal. (gallons) 1 L = 1.06 qt. (quart) Amount of Substance Conversion: 1 mol = 6.022·1023 molecules Density Conversions: 1 Mg/m3 = 1 g/cm3 1 g/cm3 = 0.0361 lb./in.3 (pound per cubic inch) 1 kg/m3 = 10-3 g/cm3 Temperature Conversion: to convert K to °F (fahrenheit), multiply by 1.8 then subtract 459.4°F to convert °C to °F (fahrenheit), multiply by 1.8 then add 32°F Heating and Cooling Rate Conversions: 1 K/s = 1°C/s = 1.8°F/s 1 K/min = 1.8°F/min Mass Conversions: 1 g = 0.035 oz. (ounce) 1 kg = 2.2 lb. (pound) 1 Mg = 1.1 ton (ton = 2,000 pounds) Force Conversions: 1 N = 105 dyne 1 N = 0.225 lb. force (pound force) Pressure, Stress and Strength Conversions: 1 Pa = 0.0075 torr (millimeter of mercury)

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1 Pa = 10 dyne/cm2 (dyne per centimeter square) 1 kPa = 0.145 psi (pounds per square inch) 1 MPa = 9.87 bar (atmosphere) 1 MPa = 145 psi (pounds per square inch) 1 MPa = 0.145 kpsi (thousand pounds per square inch) 1 Gpa = 145 kpsi (thousand pounds per square inch) Energy Conversions: 1 J = 9.48 ·10-4 btu (British thermal unit) 1 J = 0.737 ft.·lb. (foot pound) 1 J = 0.239 cal (calorie) 1 J = 107 erg 1 J = 2.8 ·10-7 kw ·h (kilowatt hour) 1 J = 6.24 ·1018 eV (electron volt) 1 J = 4.83 hp · h (horsepower · hour) 1 J = 1 W· s (watt second) 1 J = 1 V· C (volt coulomb) 1 kJ = 0.239 kcal (kilocalorie) Power Conversions: 1 W = 0.737 ft.· lb./s (foot pound per second) 1 W = 1.34 ·10-3 hp (horsepower) Thermal Conversions: 1 J/(kg · K) = 2.39 ·10-4 btu/(lb .·°F) (British thermal unit per pound per degree fahrenheit) 1 J/(kg · K) = 2.39 ·10-4 cal/(g ·°C) (calorie per gram per degree celsius) 1 W/(m · K) = 0.578 btu/(ft.· h · °F) (British thermal unit per foot per hour per degree fahrenheit) 1 W/(m · K) = 2.39 · 10-3 cal/(cm · s · °C) (calorie per centimeter per second per degree celsius) Viscosity Conversions: 1 Pa· s = 1 kg/(m · s) 1 Pa· s = 10 P (poise) 1 Pa· s = 103 cP (centipoise) Stress Intensity Conversion: 1 MPa · m1/2 = 0.91 kpsi · in.1/2 (kilopounds per square inch times square root inch) Magnetic Conversions: 1 T = 104 G (gauss) 1 A/m = 1.257· 10-2 Oe (oersted) 1 Wb = 108 Maxwell Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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YEARLY CONTENTS INTERNATIONAL JOURNAL OF POWDER METALLURGY TABLE OF CONTENTS FOR VOLUME 43, NUMBERS 1–6, 2007 43/1 JANUARY/ FEBRUARY 2007 3 5 7 9 13 15

Editor’s Note Newsmaker John F. Sweet, PMT PM Industry News in Review Company Profile Hawk MIM PMT Spotlight On …Denis Christopherson Consultants’ Corner James G. Marsden, FAPMI

OUTSTANDING TECHNICAL PAPER FROM POWDERMET2006 17 Dimensional Control In Copper/Nickel-Containing Ferrous Powder Metallurgy Alloys B. Lindsley and T. Murphy ARCHAEOTECHNOLOGY 27 About the Pre-Hispanic Au-Pt “Sintering” Technique for Making Alloys M. Noguez, R. Garcia, G. Salas, T. Robert and J. Ramirez RESEARCH & DEVELOPMENT 35 Production of Nanometric Tungsten Carbide Powders by Planetary Milling B.G. Butler, J. Lu, Z.Z. Fang and R.K. Rajamani 45 48 49 64

DEPARTMENTS Conference Report Meetings and Conferences Web Site Directory Advertisers’ Index

43/2 MARCH/APRIL 2007 3 4 7 11 13

FOCUS: HARDMETALS 17 Hardmetals: Past, Present, and Future A. Bose 21 Magnetic Saturation and Coercivity Measurements on Chromium-Doped Cemented Carbides G.K. Schwenke and J.V. Sturdevant 33 Recent Advances in Tungsten-Based Hardmetals P.K. Mehrotra, K.P. Mizgalski and A.T. Santhanam 41 Early-Stage Sintering Densification and Grain Growth of Nanosized WC-Co Powders P. Maheshwari, Z. Fang and H.Y. Sohn 49 Microwave Sintering of Submicron Cemented Carbides L. Chen, T. Dennis, P. Gigl and B. Hampshire 60 61 63 64

ENGINEERING & TECHNOLOGY 41 Evaluation of Global PM Oil-Impregnated Bearings H.I. Sanderow, FAPMI and L.F. Pease III, FAPMI, PMTII 49 Chip Reclamation in Green Machining for HighPerformance PM Components E. Robert-Perron, C. Blais, S. Pelletier, Y. Thomas and S. St-Laurent RESEARCH & DEVELOPMENT 57 Kinetics of Cobalt Gradient Formation During Liquid-Phase Sintering of Functionally Graded WC-Co O. Eso, Z.Z. Fang and A. Griffo 65 66 69 71 72

DEPARTMENTS Meetings and Conferences APMI Membership Application Instructions for Authors PM Bookshelf Advertisers’ Index

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

DEPARTMENTS Meetings and Conferences Instructions for Authors PM Bookshelf Advertisers’ Index

43/4 JULY/AUGUST 2007

43/3 MAY/JUNE 2007 3 Editor's Note 7 PM Industry News in Review 9 Growth Opportunities for PM in India Peter K. Johnson 15 PMT Spotlight On … Timothy J. Hokkanen 17 Consultants’ Corner Howard I. Sanderow, FAPMI 21 New Technology Drives PM’s Future Peter K. Johnson 29 Exhibitor Showcase: PowderMet2007

Editor’s Note PM Industry News in Review Company Profile Korea Sintered Metals PMT Spotlight On …Charles B. Wood Consultants’ Corner Brian H. Pittenger

3 5 9 11 15

Editor's Note PM Industry News in Review PMT Spotlight On … Patricia A. Ditson Consultants’ Corner Myron I. Jaffe APMI Fellow Awards Thomas F. Murphy and Howard I. Sanderow 17 2007 PM Design Excellence Awards Winners P.K. Johnson HEALTH & ENVIRONMENT 27 The New European REACH Regulation: A Major Challenge to Manufacturers and Importers P. Brewin ENGINEERING & TECHNOLOGY 33 State of the PM Industry in North America—2007 E. Daver and C.J. Trombino RESEARCH & DEVELOPMENT 39 High-Performance PM Steels Utilizing Extra-Fine Nickel L. Azzi, T. Stephenson, S. Pelletier and S. St-Laurent 51 Precipitation Hardening PM Stainless Steels C. Schade, P. Stears, A. Lawley and R.D. Doherty 60 61 63 64

DEPARTMENTS Meetings and Conferences APMI Membership Application PM Bookshelf Advertisers’ Index

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YEARLY CONTENTS 43/5 SEPTEMBER/OCTOBER 2007 2 3 7 9 11 17

23 31 43 55

Editor's Note Newsmaker Chaman Lall PM Industry News in Review PMT Spotlight On … Ken Watson Consultants’ Corner Olle Grinder PM Metallography Competition Grand Prize FOCUS: COPPER PM—NEW DEVELOPMENT & APPLICATIONS Expanding the Market for PM Copper: Beyond Self-Lubricating Bearings P. Taubenblat Electronic Applications for Copper Powder J.A. Shields, Jr. and I. Smid Copper-Base PM—Past, Present & Future W. Ullrich Metal Powder Injection Molding of Copper and Copper Alloys for Microelectronic Heat Dissipation R.M. German and J.L. Johnson

64 Advertisers’ Index

43/6 NOVEMBER/DECEMBER 2007 2 5 7 9 11

Editor's Note Newsmaker Alexander Litvintsev PM Industry News in Review PMT Spotlight On … Maryann Wright PM Metallography Competition Research & Development, Product/Process Control and Artistic Categories 25 Outstanding Poster Awards Y.I. Seo, D.H. Shin, K.H. Min, Y.D. Yoon, S-Y Chang, K.H. Lee, and Y.D. Kim; C. McClimon, J.J. Williams and N. Chawla 27 Consultants’ Corner J.T. Strauss 35 Axel Madsen/CPMT Scholar Reports P. Lapointe, C. McClimon, D. Sampson and M. Sexton ENGINEERING & TECHNOLOGY 39 Lubricants for High-Density Compaction at Moderate Temperatures L. Azzi, Y. Thomas and S. St-Laurent RESEARCH & DEVELOPMENT 47 R&D in Support of Powder Injection Molding: Status and Projections R.M. German 59 Sintering Response & Microstructural Evolution of an Al-Cu-Mg-Si Premix J.M. Martin and F. Castro 71 72 75 77 79 80

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DEPARTMENTS Meetings and Conferences APMI Membership Application Instructions for Authors Table of Contents: Volume 43, Numbers 1–6, 2007 PM Bookshelf Advertisers’ Index

Volume 43, Issue 6, 2007 International Journal of Powder Metallurgy

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ADVERTISERS’ INDEX

ADVERTISER

FAX

WEB SITE

PAGE

ABBOTT FURNACE COMPANY __________________(814) 781-7334_______www.abbottfurnace.com______________________58 ACUPOWDER INTERNATIONAL, LLC _____________(908) 851-4597_______www.acupowder.com ________________________34 ASBURY CARBONS ___________________________(908) 537-2908_______www.asbury.com ___________________________10 ELNIK SYSTEMS _____________________________(973) 239-6066_______www.elnik.com _____________________________20 HOEGANAES CORPORATION ___________________(856) 786-2574_______www.hoeganaes.com ________INSIDE FRONT COVER KITTYHAWK PRODUCTS _______________________(714) 895-5024_______www.kittyhawkinc.com_______________________22 NORILSK NICKEL ____________________________(+ 7 495) 785 58 08 ___www.norilsknickel.com _______________________4 NORTH AMERICAN HÖGANÄS INC. ______________(814) 479-2003_______www.nah.com _______________________________3 PRINCETON ONE_____________________________(440) 243-4868_______www.princetonone.com ______________________31 QMP ______________________________________(734) 953-0082_______www.qmp-powders.com _____________BACK COVER SCM METAL PRODUCTS, INC. __________________(919) 544-7996_______www.scmmetals.com _________INSIDE BACK COVER

ADVERTISER’S REQUEST FOR INFORMATION FAX FORM Need more information on products or services seen in this issue? Complete the form below and fax to the advertiser(s) of your choice. Fax numbers are listed in the advertisers’ index above.

international journal of

powder metallurgy

To:___________________________________ Fax #: ____________________________________________________________________ Company: _______________________________________________________________________________________________________ Please send me more information on: __________________________________________________________________________ __________________________________________________________________________________________________________________ as advertised in the __________ issue of the International Journal of Powder Metallurgy. Please send information to: Name: Title:______________________________________________________________________________________________________ Company: _______________________________________________________________________________________________________ Address: _________________________________________________________________________________________________________ City:____________________________ State:_______________ Postal Code: ____________________________________________ Country: _________________________________________________________________________________________________________ Phone:___________________ Fax:___________________ E-Mail: ______________________________________________________

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SCM's products include: • • • • • • •

North Carolina USA

Manufacturing Sites • Research Triangle Park, North Carolina USA • Suzhou, China Tel: 919-544-8090 • www.SCMmetals.com

Copper, Tin and Bronze Premix Powders Prealloyed Bronze and Brass Powders Copper Base Infiltrating Powders High Green Strength Copper Powders Copper Oxides Copper Base Catalyst Powders Cubond® Furnace Brazing Pastes

Suzhou China

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