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Influence of machining parameters on machinability of sintered steels
thin diamond coated tools are now commercially available in quantity and are used in a range of industies. Applications in machining of graphitic materials, plastics, composites and automotive parts were outlined. MICROSTRUCTURE AND CUTTING PERFORMANCE OF DIAMOND COATED CEMENTED CARBIDE Q. Deng. (Zhuzhou Cemented Carbide Works, China.) It was reported that diamond coatings had been deposited on WC-Co and WC-TiCCo substrates by hot filament assisted chemical vapour deposition. Films were characterized for structure and adhesion measured by a scratch test. Cutting performance was assessed by turning tests. Small amounts of wear, without flaking, were found when cutting Al-Si and Cu-Sn alloys. Coating was reported to extend tool life by a factor of 5. 1996 WORLD CONGRESS ON POW-
DER METALLURGY.The abstracts which follow are from papers which were presented at the Congress, which was held in Washington DC, UsA, in June 1996.
Aluminium
sintering
PARTICLE SIZE EFFECTS IN MULTICOMPONENT ALUMINIUM ALLOYS
R.N. Lumley, G.B. Schaffer. (University of Queensland, Australia.) Structural evolution during LPS of Al alloys was investigated with regard to composition and effects of additive particle size. It was reported that larger particles increased the amount of liquid phase. Structural development was shown to be influenced by interactions between alloy elements and was discussed in terms of solubility and diffusion effects. SINTERING OF HIGH TEMPERATURE RESISTANT PM ALUMINIUM ALLOYS J. Duszczuk et al. (Technological University, Delft, The Netherlands.) Al-2O%Si-X alloys were discussed with reference to automotive applications. Gas atomized A1-20%Si-5%Fe-2%Ni powders were characterized and fabricated by uniaxial pressing or CIP and sintered at a range of temperatures in N or air. Structure and properties were described. N atomized powder gave better part properties than air atomized powders.
Machinability ENHANCED MACHINABILITY OF VALVE GUIDES MADE FROM PM MATERIALS K Hayashi et al. (Hitachi Powdered Metals Co. Ltd., Chiba, Japan.)
It was noted that valve guides need wear resistance in service but machinability during manufacture. PM guides made from Cu-Sn-C-P steel were reported to have adequate wear resistance but machinability needed improvement. Machining enhancers, including MnS, were investigated. Machinability was shown to be enhanced without loss of wear resistance.
material of defined fine grain size, which are required for H storage, including melt spinning, atomization and crushing of bulk materials. Results were presented.
MACHINABILITY OF SINTERED 316L STAINLESS STEEL
A. Lawley, X. Du. (Drexel University, USA) Production of PM Mo-V-Nb steels was outlined. Fe-MO powders were blended with graphite and ferro-V or ferro-Nb, pressed and sintered for 30 mins at 1300°C in a N-H mixture of low dew point. Structure and properties were evaluated in assintered and heat treated states. It was concluded that solid phase hardening by Nb or V had been attained. Energetics of the processing were analysed and properties related to structure.
U. Kutsch, P. Beiss. (Inst. for Materials Science, Germany.) Investigation of the effects of MnS content, sintering atmosphere and cutting conditions on dry drilling machinability of 316L stainless steel was described. MnS improved machinability in terms of tool life and cost per hole. The results were reported to allow quantified minimization of production costs. INFLUENCE OF MACHINING PARAMETERS ON MACHINABILITY OF SINTERED STEELS L. Hultman. (Hans AB, Hans, Sweden.) Complexities of machining were discussed with reference to cutting conditions and work material characteristics. A range of cutting operations were carried out on several sintered steels. Cutting forces, surface finish, wear patterns and other factors were determined for different tools and machining parameters. Recommendations were given.
Powder production MONODISPERSE METAL POWDERS OF CONTROLLED SIZE AND SHAPE MADE BY POLYOL
PROCESS
K. Tekaia-Elhsissen, P.Y. Silvert. (University
of Piccardy, France.) The need for metal powders on high purity and uniform size and shape was noted. Production of metal powders by reduction of a metal salt in a non-aqueous solvent, polyol, was described with reference to stages in the process, dissolution of the salt, reduction, nucleation and growth of particles and effects of reaction parameters. It was reported that a range of metal and alloy powders with controlled size and shape had been made. POWDER PRODUCTION METHODS FOR HYDROGEN STORAGE MATERIALS MJ. Hohmann, HJ. Klmner. (AID Vacuum Technologies GmbH., Germany.) The potential of PM technologies for mass production of materials for H storage was noted. The paper reviewed methods for production of rapidly solidified high purity
High alloy sintering HIGH TEMPERATURE SINTERING OF NIOBIUM-VANADIUM STEELS
SINTERING OF A 4401 BASED STEEL P. Francois, E. Gautier. (Ecole des Mines de Nancy, France.) A study of the effects of sintering time and temperature on the hardenability of a 0.6%C-4.5%Ni-1.5%Cu-0.85%Mo-0.22%Mn steel was described. Sintering, in a dilatometer, was at 1120°C in H-N for 17, 25 or 35 minutes and cooling was at five different rates. Structures and hardnesses were determined. Transformation temperatures were identified for heating and cooling and a continuous cooling transformation diagram constructed.
High performance
materials
DESIGN OF LOW ALLOY STEEL POWDERS FOR SIN-TERIIARDENING APPLICATIONS F. Chagnon, Y. Trudel. (Quebec Metal Powders Ltd., Montreal, Canada.) Sinterhardening of steel was discussed with regard to the attendant reduction in processing and improved dimensional control. A programme to evaluate the of alloy elements on effects sinterhardenability was described. Atomized powders were pressed and sintered in furnaces with the option for variable cooling rates. Materials were characterized for structure and properties a composition for to optimize sinterhardenability at low cost. DEVELOPMENT OF HIGH PERFORMANCE PM STEELS R.J. Causton. (Hoeganaes Corporation, Riverton, New Jersey, USA) The paper critically examined materials development and the microstructural controls required to meet the demands for the production of new PM steel parts.
MPR February 1997 39
DER METALLURGY.The abstracts which follow are from papers which were presented at the Congress, which was held in Washington DC, UsA, in June 1996.
Aluminium
sintering
PARTICLE SIZE EFFECTS IN MULTICOMPONENT ALUMINIUM ALLOYS
R.N. Lumley, G.B. Schaffer. (University of Queensland, Australia.) Structural evolution during LPS of Al alloys was investigated with regard to composition and effects of additive particle size. It was reported that larger particles increased the amount of liquid phase. Structural development was shown to be influenced by interactions between alloy elements and was discussed in terms of solubility and diffusion effects. SINTERING OF HIGH TEMPERATURE RESISTANT PM ALUMINIUM ALLOYS J. Duszczuk et al. (Technological University, Delft, The Netherlands.) Al-2O%Si-X alloys were discussed with reference to automotive applications. Gas atomized A1-20%Si-5%Fe-2%Ni powders were characterized and fabricated by uniaxial pressing or CIP and sintered at a range of temperatures in N or air. Structure and properties were described. N atomized powder gave better part properties than air atomized powders.
Machinability ENHANCED MACHINABILITY OF VALVE GUIDES MADE FROM PM MATERIALS K Hayashi et al. (Hitachi Powdered Metals Co. Ltd., Chiba, Japan.)
It was noted that valve guides need wear resistance in service but machinability during manufacture. PM guides made from Cu-Sn-C-P steel were reported to have adequate wear resistance but machinability needed improvement. Machining enhancers, including MnS, were investigated. Machinability was shown to be enhanced without loss of wear resistance.
material of defined fine grain size, which are required for H storage, including melt spinning, atomization and crushing of bulk materials. Results were presented.
MACHINABILITY OF SINTERED 316L STAINLESS STEEL
A. Lawley, X. Du. (Drexel University, USA) Production of PM Mo-V-Nb steels was outlined. Fe-MO powders were blended with graphite and ferro-V or ferro-Nb, pressed and sintered for 30 mins at 1300°C in a N-H mixture of low dew point. Structure and properties were evaluated in assintered and heat treated states. It was concluded that solid phase hardening by Nb or V had been attained. Energetics of the processing were analysed and properties related to structure.
U. Kutsch, P. Beiss. (Inst. for Materials Science, Germany.) Investigation of the effects of MnS content, sintering atmosphere and cutting conditions on dry drilling machinability of 316L stainless steel was described. MnS improved machinability in terms of tool life and cost per hole. The results were reported to allow quantified minimization of production costs. INFLUENCE OF MACHINING PARAMETERS ON MACHINABILITY OF SINTERED STEELS L. Hultman. (Hans AB, Hans, Sweden.) Complexities of machining were discussed with reference to cutting conditions and work material characteristics. A range of cutting operations were carried out on several sintered steels. Cutting forces, surface finish, wear patterns and other factors were determined for different tools and machining parameters. Recommendations were given.
Powder production MONODISPERSE METAL POWDERS OF CONTROLLED SIZE AND SHAPE MADE BY POLYOL
PROCESS
K. Tekaia-Elhsissen, P.Y. Silvert. (University
of Piccardy, France.) The need for metal powders on high purity and uniform size and shape was noted. Production of metal powders by reduction of a metal salt in a non-aqueous solvent, polyol, was described with reference to stages in the process, dissolution of the salt, reduction, nucleation and growth of particles and effects of reaction parameters. It was reported that a range of metal and alloy powders with controlled size and shape had been made. POWDER PRODUCTION METHODS FOR HYDROGEN STORAGE MATERIALS MJ. Hohmann, HJ. Klmner. (AID Vacuum Technologies GmbH., Germany.) The potential of PM technologies for mass production of materials for H storage was noted. The paper reviewed methods for production of rapidly solidified high purity
High alloy sintering HIGH TEMPERATURE SINTERING OF NIOBIUM-VANADIUM STEELS
SINTERING OF A 4401 BASED STEEL P. Francois, E. Gautier. (Ecole des Mines de Nancy, France.) A study of the effects of sintering time and temperature on the hardenability of a 0.6%C-4.5%Ni-1.5%Cu-0.85%Mo-0.22%Mn steel was described. Sintering, in a dilatometer, was at 1120°C in H-N for 17, 25 or 35 minutes and cooling was at five different rates. Structures and hardnesses were determined. Transformation temperatures were identified for heating and cooling and a continuous cooling transformation diagram constructed.
High performance
materials
DESIGN OF LOW ALLOY STEEL POWDERS FOR SIN-TERIIARDENING APPLICATIONS F. Chagnon, Y. Trudel. (Quebec Metal Powders Ltd., Montreal, Canada.) Sinterhardening of steel was discussed with regard to the attendant reduction in processing and improved dimensional control. A programme to evaluate the of alloy elements on effects sinterhardenability was described. Atomized powders were pressed and sintered in furnaces with the option for variable cooling rates. Materials were characterized for structure and properties a composition for to optimize sinterhardenability at low cost. DEVELOPMENT OF HIGH PERFORMANCE PM STEELS R.J. Causton. (Hoeganaes Corporation, Riverton, New Jersey, USA) The paper critically examined materials development and the microstructural controls required to meet the demands for the production of new PM steel parts.
MPR February 1997 39