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Compaction of a stainless steel using a die wall lubrication system
MMC PRODUCTION AND CHARACTERIZATION BY REACTIVE METAL PENETRATION
A.Casagrande et al. (University of Bologna, Italy. I It was reported that metal matrix composites can be prepared by displacement reactions in systems such as Al-CuO and Al-SiO, yielding Al-CuAl,O, and Al-Si-Al,O,. Investigations were carried out to optimize process conditions. The energetics of the displacement reactions were discussed and processed materials were characterized. The properties of the composites were compared with those of composite materials made by other methods. USE OF HIGH TEMPERATURE SELF SUSTAINING SYNTHESIS FOR PRODUCTION OF POWDERS
J.V.Wood et al. (University of Nottingham, UK. ) SHS was discussed with reference to use in preparation of materials reinforced with ceramic particles, which are not easily produced by other means. Both ferrous and non-ferrous alloys can be made with ceramic reinforcements such as TIC and other carbides, and TiB,. The powders can be processed by conventional PM technology into wear and abrasion resistant parts. It was noted that there is a wide choice of matrix and reinforcement materials.
~PM2TEC’98. The following Abstracts are of papers that were presented at the 1998 International Conference on Powder Metallurgy and Particulate Materials held in Las Vegas, NV, USA, in June 1998.
Copper
powders
FlNE PARTICLE SIZE COPPER POWDERS FROM OXIDE RAW MATERIALS
N.Blossom et al. (American Chemet Corp, USA.) It was reported that lo-23 pm copper powders had been prepared from Cu,O feedstock. Relationships between the properties of Cu and Cu,O powders were reviewed. Effects ofreduction conditions on characteristics of the Cu powder were described. Applications of the powder and tests results in blends with Fe and in MIM use were presented. ELECTROLYTIC
COPPER POWDER
B.Mais, G.A.Mowbray. (Mowbray Industrial Consultants, UK.) It was noted that the production of electrolytic Cu powder had ceased in N. America although it was still widely used.
Recent developments to ensure environmentally friendly production, avoidance of toxic waste and improved efficiency of production from lean Cu ores and process residues were reported. Dust-free powders with an apparent density of 0.5 g.cm’ were reported to be available. It was shown that electrolytic Cu powder is particularly suitable for diffusion bonding. MODIFICATION OF PROPERTIES OF BRONZE BY PARTIAL PREALLOYING OF POWDERS D.F.Berry, W.K.Daye. (OMG Americas, USA.) Segregation, distortion and porosity occurring in 90/10 bronzes made from elemental powders were noted. It was shown that these can be minimized by use of prealloyed powders, which gives parts with a uniform microstructure, finer porosity, lower permeability and better surface finish. Parts can be made to closer dimensional tolerances. Details of green and sintered properties were described.
Stainless
stee/
EFFECTS OF DENSITY SINTERING CONDITIONS AND MICROSTRUCTURE ON FATIGUE OF STAINLESS STEEL
J.R.Spirko et al. (Concurrent Technologies Corp, USA.) Fatigue properties of six stainless steels were investigated by a rotating beam technique. Density was reported to be the most significant factor in influencing fatigue, composition and process conditions having only secondary effects. Small changes in microstructure, resulting from changes in process conditions, were insignificant. The highest fatigue strength was for 3431, steel. ELEVATED TEMPERATURE DESIGN PROPERTIES OF PM STAINLESS STEELS
F.G.Hanejko et al. (Hoeganaes Corp, Riverton, USA.) It was reported that the use of binder treated materials, such as ANCORBOND and ANCORDENSE, resulted in improved ferrous part performance. Current and future applications were outlined.
T.Cimino et al. (Hoeganaes Corp, Riverton, USA.) High temperature automotive applications of PM stainless steels were discussed with regard to mechanical properties and part design. Thermomechanical properties, relevant to design for high temperature application, of a range of stainless steels were investigated with and without the effects of corrosion. Results for PM and conventional wrought materials were compared to evaluate the suitability of the PM materials for relatively severe conditions in automotive applications.
HIGHER GREEN STRENGTH AND IMPROVED DENSITY BY CONVENTIONAL COMPACTION
COMPACTION OF A STAINLESS STEEL USING A DIE WALL LUBRICATION SYSTEM
S.H.Luk et al. (Hoeganaes Corp, Riverton, USA.) Development of a 0.85%Mo-2%Nilpgraphite steel, when pressed by a new system from prealloyed powder at 50 ton.ine2, was reported to have a green strength of 6983 psi and a density of 7.26 g.cm-? Conventionally pressed powder had a green strength of 2709 psi and 7.14 g.cm.” green density.
G.D.Flick, G.M.Angelo. (Gasbarre Products Inc, USA.) Investigations of the effect of varying the amount of Acrawax lubricant, used in the compaction of 409CB stainless steel, pressed at various loads with die wall lubrication, were described. The results were discussed.
GRAPHITE FORMATION IN BORON CONTAINING FERROUS ALLOYS AND
'CONTIBLU'- A NEW PROCESS FOR
Lubrication APPLICATION OF HIGH PERFORMANCE BINDER TREATED MATERIAL
SELF LUBRICATING EFFECTS
H.Nishie et al. (Mitsubishi Materials Corp, Japan.) Graphitization in Fe-Cu-C alloys, with graphite enhancers BN and Si, was investigated. BN was shown to be a potent graphitizer. Graphite precipitated on pore surfaces and morphology depended on pore shape. The precipitated graphite was an effective self lubricant. Effects of other elements, Mn, Cr, Ni and MO, were discussed.
Post sintering CONTINUOUS
treatment
STEAM TREATMENT
F.Sarnes et al. (SARNES Ingenieure, Germany. ) It was reported that a novel technique had been used for continuous steam treatment to oxidize PM steel parts. The system avoids the need for a boiler to produce steam. The process is multifunctional and couples generation of protective atmosphere, furnace heating and afterburning of flue gas. Energy consumption was small and the technique was shown to be cost effective.
MPR November 1998 41
A.Casagrande et al. (University of Bologna, Italy. I It was reported that metal matrix composites can be prepared by displacement reactions in systems such as Al-CuO and Al-SiO, yielding Al-CuAl,O, and Al-Si-Al,O,. Investigations were carried out to optimize process conditions. The energetics of the displacement reactions were discussed and processed materials were characterized. The properties of the composites were compared with those of composite materials made by other methods. USE OF HIGH TEMPERATURE SELF SUSTAINING SYNTHESIS FOR PRODUCTION OF POWDERS
J.V.Wood et al. (University of Nottingham, UK. ) SHS was discussed with reference to use in preparation of materials reinforced with ceramic particles, which are not easily produced by other means. Both ferrous and non-ferrous alloys can be made with ceramic reinforcements such as TIC and other carbides, and TiB,. The powders can be processed by conventional PM technology into wear and abrasion resistant parts. It was noted that there is a wide choice of matrix and reinforcement materials.
~PM2TEC’98. The following Abstracts are of papers that were presented at the 1998 International Conference on Powder Metallurgy and Particulate Materials held in Las Vegas, NV, USA, in June 1998.
Copper
powders
FlNE PARTICLE SIZE COPPER POWDERS FROM OXIDE RAW MATERIALS
N.Blossom et al. (American Chemet Corp, USA.) It was reported that lo-23 pm copper powders had been prepared from Cu,O feedstock. Relationships between the properties of Cu and Cu,O powders were reviewed. Effects ofreduction conditions on characteristics of the Cu powder were described. Applications of the powder and tests results in blends with Fe and in MIM use were presented. ELECTROLYTIC
COPPER POWDER
B.Mais, G.A.Mowbray. (Mowbray Industrial Consultants, UK.) It was noted that the production of electrolytic Cu powder had ceased in N. America although it was still widely used.
Recent developments to ensure environmentally friendly production, avoidance of toxic waste and improved efficiency of production from lean Cu ores and process residues were reported. Dust-free powders with an apparent density of 0.5 g.cm’ were reported to be available. It was shown that electrolytic Cu powder is particularly suitable for diffusion bonding. MODIFICATION OF PROPERTIES OF BRONZE BY PARTIAL PREALLOYING OF POWDERS D.F.Berry, W.K.Daye. (OMG Americas, USA.) Segregation, distortion and porosity occurring in 90/10 bronzes made from elemental powders were noted. It was shown that these can be minimized by use of prealloyed powders, which gives parts with a uniform microstructure, finer porosity, lower permeability and better surface finish. Parts can be made to closer dimensional tolerances. Details of green and sintered properties were described.
Stainless
stee/
EFFECTS OF DENSITY SINTERING CONDITIONS AND MICROSTRUCTURE ON FATIGUE OF STAINLESS STEEL
J.R.Spirko et al. (Concurrent Technologies Corp, USA.) Fatigue properties of six stainless steels were investigated by a rotating beam technique. Density was reported to be the most significant factor in influencing fatigue, composition and process conditions having only secondary effects. Small changes in microstructure, resulting from changes in process conditions, were insignificant. The highest fatigue strength was for 3431, steel. ELEVATED TEMPERATURE DESIGN PROPERTIES OF PM STAINLESS STEELS
F.G.Hanejko et al. (Hoeganaes Corp, Riverton, USA.) It was reported that the use of binder treated materials, such as ANCORBOND and ANCORDENSE, resulted in improved ferrous part performance. Current and future applications were outlined.
T.Cimino et al. (Hoeganaes Corp, Riverton, USA.) High temperature automotive applications of PM stainless steels were discussed with regard to mechanical properties and part design. Thermomechanical properties, relevant to design for high temperature application, of a range of stainless steels were investigated with and without the effects of corrosion. Results for PM and conventional wrought materials were compared to evaluate the suitability of the PM materials for relatively severe conditions in automotive applications.
HIGHER GREEN STRENGTH AND IMPROVED DENSITY BY CONVENTIONAL COMPACTION
COMPACTION OF A STAINLESS STEEL USING A DIE WALL LUBRICATION SYSTEM
S.H.Luk et al. (Hoeganaes Corp, Riverton, USA.) Development of a 0.85%Mo-2%Nilpgraphite steel, when pressed by a new system from prealloyed powder at 50 ton.ine2, was reported to have a green strength of 6983 psi and a density of 7.26 g.cm-? Conventionally pressed powder had a green strength of 2709 psi and 7.14 g.cm.” green density.
G.D.Flick, G.M.Angelo. (Gasbarre Products Inc, USA.) Investigations of the effect of varying the amount of Acrawax lubricant, used in the compaction of 409CB stainless steel, pressed at various loads with die wall lubrication, were described. The results were discussed.
GRAPHITE FORMATION IN BORON CONTAINING FERROUS ALLOYS AND
'CONTIBLU'- A NEW PROCESS FOR
Lubrication APPLICATION OF HIGH PERFORMANCE BINDER TREATED MATERIAL
SELF LUBRICATING EFFECTS
H.Nishie et al. (Mitsubishi Materials Corp, Japan.) Graphitization in Fe-Cu-C alloys, with graphite enhancers BN and Si, was investigated. BN was shown to be a potent graphitizer. Graphite precipitated on pore surfaces and morphology depended on pore shape. The precipitated graphite was an effective self lubricant. Effects of other elements, Mn, Cr, Ni and MO, were discussed.
Post sintering CONTINUOUS
treatment
STEAM TREATMENT
F.Sarnes et al. (SARNES Ingenieure, Germany. ) It was reported that a novel technique had been used for continuous steam treatment to oxidize PM steel parts. The system avoids the need for a boiler to produce steam. The process is multifunctional and couples generation of protective atmosphere, furnace heating and afterburning of flue gas. Energy consumption was small and the technique was shown to be cost effective.
MPR November 1998 41