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Improvement in sintering quality in a multi-chamber vacuum sintering furnace
of Al, during CIP in rubber moulds, at up to 400 MPa, was described. PRODUCTION OF HIGH DENSITY NEAR NET SHAPE PARTS BY ROTOPRESSING W. Sobol et al (Rotopress International lnc, Quebec, Canada.) A rotary forming press for repressing of sintered parts was described. This uses less force that required for uniaxial repressing and densities of 95 to 98% were attained with improved dimensional accuracy and surface quality. The process was discussed in detail. VIBRATORY POWDERS DIE FILLING ON AN ELECTRIC DRIVE CNC COMPACTING PRESS H. Tsuru, T. Nakagawa (University of Tokyo, Tokyo, Japan) The need for uniform die filling in order to attain uniform density in parts was discussed with regard to physicomechanical factors. A computer controlled vibratory die filling system fitted to an electric drive CNC compacting press was described.
Sintering consolidation MODELLING OF GAS FLOW IN SINTERING FURNACE M.Petit et al (Pechiney CRV, Voreppe, France) (In French). A model of the gas flow field in a continuous sintering furnace was described. The presintering zone where there is lubricant/binder burn off was particularly considered with regard to the removal of gaseous products. The model takes the aerodynamic behaviour of the sintering atmosphere into account using finite element methods. SINTERING OF PM PARTS WITH A MODIFIED ZONED SYNTHETIC ATMOSPHERE
de-lubrication, sintering and cooling are carried out in separate chambers and the processing is computer controlled resulting in close control of dimensional tolerances and part properties. Results of sintering of hardmetals were presented. MAGNETIC PULSE PRESSING OF POWDERS AND SHAPING OF POWDER PRODUCTS V.Mironov (Riga Technical University, Riga, Latvia) The use of a pulsed electromagnetic field during the pressing of powders was discussed with respect to effects on structure and properties of products. Some examples of re-pressing of previously sintered parts were presented. A NEW CONCEPT FOR ATMOSPHERE PRODUCTION FOR POWDER METALLURGUY APPLICATION
EFFECT OF PRESSING CONDITIONS ON STRUCTURE AND PROPPERTIES OF ALUMINIUM ALLOYS
P. Pourtalet et al (Air Liquide, Loges en Josas, France) A method for reducing the 0 content of N, for use in sintering, from 0.5/5% down to below 5 ppm was outlined. The method is based on catalytic reduction of 0 with hydrocarbons. Improved part quality was reported.
A.Y. Kern (Mikrotekhnika, Rostow-on Don, Russia) Studies of the effects of lubricants on pressing and properties of Al compacts with Cu or Mg were described. A solid lubricant is shown to decrease strength and ductility by interfering with particle interfaces by contamination.
Aluminium
DETERMINATION OF LOAD FOR OPEN PIERCING OF SINTERED ALUMINIUM POWDER
alloys
PRODUCTION OF ALUMINIUM ALLOY PARTICLE COMPOSITES BY POWDER METALLURGY S. Holecek et al (Prague Inst. of Chemical Technology, Prague, Czech Republic) It was reported that hot pressing had been used to produce an Al-Si-Ni-Cu-FeMn-Ti alloy matrix composite with AlzO,, Si3N4, Sic or WC particle reinforcements. Increased hardness and improved wear properties were reported. POWDER METALLURGY ALUMINIUM ALLOY PISTONS FOR MOTORCYCLE ENGINES I. Koike, H. Yamagata (Yamaha Motor Co, Shizuoka, Japan) The use of a &17%Si-2%Fe-2%Mg-l%Cu1XNi alloy to make motorcycle pistons was reported. The alloy was shown to have high strength at elevated temperature, high resistance to degradation of properties with time, and good fatigue strength. The properties were said to be superior to those of cast pistons.
IMPROVEMENT IN SINTERING QUALITY IN A MULTI-CHAMBER VACUUM SINTERING FURNACE
IMPROVEMENT OF MECHANICAL PROPERTIES OF HIP ALUMINIUM ALLOY BY EXTRUSION
F. Bless, L. Oimann (lpsen Industries Int. GmbH, Kleve, Germany) Use of a three chamber vacuum sintering furnace was described in which
K Hanada et al (University of ElectroCommunication, Tsukuba lbaraki, Japan.) Fracture of HIP Al-Li alloys at prior particle boundaries, resulting in inadequate
MPR March 1995
EFFECT OF POWDER PROCESSING ON SOLID STATE BEHAVIOUR AND PROPERTIES OF ALUMINIUM ALLOY X.P. Nui et al (Katholieke University Leuven, Heverlee, Belgium) A comparison was made between Algwt%Mn alloys made from blended elemental powders and from mechanically alloyed powders and fabricated by extrusion. Formation of MnAla was studied. Double MA, with intermediate heat treatment, was reported to improve the distribution of MnAls in the alloys.
Y.T. Chen et al (Pitney Bowes lnc, Shelton, Connecticut, USA) A system for zoning the composition of the atmosphere in a sintering furnace was described. The atmosphere consisted of N, CO and H, at controlled dew point, in the burn off/preheat and first high heat zones, N and H in the sintering zone and N in cooling. The system was said to allow control of dimensional changes, zero in a Fe-C&C alloy.
40
properties, was noted. Efforts to improve this by extrusion after HIP were described. It was shown that extrusion inhibits fracture at prior particle boundaries.
G.H. Liaghat (Tarbiat Modarres University, Tehran, Iran) Calculations of the force required to pierce a sintered Al disc of diameter D with a punch of diameter d were carried out and compared with experimental measurements. It was shown that the mathematical method used could predict the force to an accuracy of 97%.
Structural applications COMPARISON OF CONVENTIONALLY MANUFACTURED AND PM GEARS N. Dautzenberg et al (Mannesmann Demag AG, Monchengladbach, Germany) The investigation described was carried out with conventional gears and gears made from water atomized heat treatable steel powders. Conventional case hardened gears had the highest levels of tooth root fatigue with the PM gear having lower values which could be improved by shot peening. Manufacturing processes were critically reviewed and it was shown that the PM single sintered gear could reduce manufacturing time by about 40%. HIGH DENSITY PM MATERIALS FOR FUTURE APPLICATIONS U. Engstron (Hogan& Al3, Ho”ganas, Sweden)
Sintering consolidation MODELLING OF GAS FLOW IN SINTERING FURNACE M.Petit et al (Pechiney CRV, Voreppe, France) (In French). A model of the gas flow field in a continuous sintering furnace was described. The presintering zone where there is lubricant/binder burn off was particularly considered with regard to the removal of gaseous products. The model takes the aerodynamic behaviour of the sintering atmosphere into account using finite element methods. SINTERING OF PM PARTS WITH A MODIFIED ZONED SYNTHETIC ATMOSPHERE
de-lubrication, sintering and cooling are carried out in separate chambers and the processing is computer controlled resulting in close control of dimensional tolerances and part properties. Results of sintering of hardmetals were presented. MAGNETIC PULSE PRESSING OF POWDERS AND SHAPING OF POWDER PRODUCTS V.Mironov (Riga Technical University, Riga, Latvia) The use of a pulsed electromagnetic field during the pressing of powders was discussed with respect to effects on structure and properties of products. Some examples of re-pressing of previously sintered parts were presented. A NEW CONCEPT FOR ATMOSPHERE PRODUCTION FOR POWDER METALLURGUY APPLICATION
EFFECT OF PRESSING CONDITIONS ON STRUCTURE AND PROPPERTIES OF ALUMINIUM ALLOYS
P. Pourtalet et al (Air Liquide, Loges en Josas, France) A method for reducing the 0 content of N, for use in sintering, from 0.5/5% down to below 5 ppm was outlined. The method is based on catalytic reduction of 0 with hydrocarbons. Improved part quality was reported.
A.Y. Kern (Mikrotekhnika, Rostow-on Don, Russia) Studies of the effects of lubricants on pressing and properties of Al compacts with Cu or Mg were described. A solid lubricant is shown to decrease strength and ductility by interfering with particle interfaces by contamination.
Aluminium
DETERMINATION OF LOAD FOR OPEN PIERCING OF SINTERED ALUMINIUM POWDER
alloys
PRODUCTION OF ALUMINIUM ALLOY PARTICLE COMPOSITES BY POWDER METALLURGY S. Holecek et al (Prague Inst. of Chemical Technology, Prague, Czech Republic) It was reported that hot pressing had been used to produce an Al-Si-Ni-Cu-FeMn-Ti alloy matrix composite with AlzO,, Si3N4, Sic or WC particle reinforcements. Increased hardness and improved wear properties were reported. POWDER METALLURGY ALUMINIUM ALLOY PISTONS FOR MOTORCYCLE ENGINES I. Koike, H. Yamagata (Yamaha Motor Co, Shizuoka, Japan) The use of a &17%Si-2%Fe-2%Mg-l%Cu1XNi alloy to make motorcycle pistons was reported. The alloy was shown to have high strength at elevated temperature, high resistance to degradation of properties with time, and good fatigue strength. The properties were said to be superior to those of cast pistons.
IMPROVEMENT IN SINTERING QUALITY IN A MULTI-CHAMBER VACUUM SINTERING FURNACE
IMPROVEMENT OF MECHANICAL PROPERTIES OF HIP ALUMINIUM ALLOY BY EXTRUSION
F. Bless, L. Oimann (lpsen Industries Int. GmbH, Kleve, Germany) Use of a three chamber vacuum sintering furnace was described in which
K Hanada et al (University of ElectroCommunication, Tsukuba lbaraki, Japan.) Fracture of HIP Al-Li alloys at prior particle boundaries, resulting in inadequate
MPR March 1995
EFFECT OF POWDER PROCESSING ON SOLID STATE BEHAVIOUR AND PROPERTIES OF ALUMINIUM ALLOY X.P. Nui et al (Katholieke University Leuven, Heverlee, Belgium) A comparison was made between Algwt%Mn alloys made from blended elemental powders and from mechanically alloyed powders and fabricated by extrusion. Formation of MnAla was studied. Double MA, with intermediate heat treatment, was reported to improve the distribution of MnAls in the alloys.
Y.T. Chen et al (Pitney Bowes lnc, Shelton, Connecticut, USA) A system for zoning the composition of the atmosphere in a sintering furnace was described. The atmosphere consisted of N, CO and H, at controlled dew point, in the burn off/preheat and first high heat zones, N and H in the sintering zone and N in cooling. The system was said to allow control of dimensional changes, zero in a Fe-C&C alloy.
40
properties, was noted. Efforts to improve this by extrusion after HIP were described. It was shown that extrusion inhibits fracture at prior particle boundaries.
G.H. Liaghat (Tarbiat Modarres University, Tehran, Iran) Calculations of the force required to pierce a sintered Al disc of diameter D with a punch of diameter d were carried out and compared with experimental measurements. It was shown that the mathematical method used could predict the force to an accuracy of 97%.
Structural applications COMPARISON OF CONVENTIONALLY MANUFACTURED AND PM GEARS N. Dautzenberg et al (Mannesmann Demag AG, Monchengladbach, Germany) The investigation described was carried out with conventional gears and gears made from water atomized heat treatable steel powders. Conventional case hardened gears had the highest levels of tooth root fatigue with the PM gear having lower values which could be improved by shot peening. Manufacturing processes were critically reviewed and it was shown that the PM single sintered gear could reduce manufacturing time by about 40%. HIGH DENSITY PM MATERIALS FOR FUTURE APPLICATIONS U. Engstron (Hogan& Al3, Ho”ganas, Sweden)