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Diffusion bonding of ferrous compacts during sintering
Powder production EFFECT OF NOZZLE GEOMETRY AND POSITION ON GAS ATOMIZATION
T. Le, H. Henein. (University of Alberta, Edmonton, Canada.) Znt. J. Powder MetalIurgv, Vol 32, No 4, 1996, 353-364. Gas atomization is discussed with reference to process design and conditions. In the study pressure measurements were made at the nozzle tip for different tip designs and the results used to optimize the design. Zn was atomized as a test material and it is reported that a narrow range of particle sizes could be obtained. PRODUCTION OF ULTRAFINE ZIRCONIA POWDERS BY SOLVENT EXTRACTION
introduced. The parameter is for spheres but can be extended to other shapes. It is shown that agglomeration is widespread in many automatic particle size analysers. DISCUSSION OF RADIAL CRUSHING STRENGTH TESTING W. Chonglin. (Metal Research Inst., Academia Sinica, China.) PM Technology, Vol 14, No 3, 1996, 206-211. (In Chinese). Stress distribution during crushing tests on rings is deduced. Tensile stress at the inner surface caused damage similar to bend tests on beams and the magnitude is related to ring dimensions. A relationship for bend strength testing by crushing is proposed. FINITE ELEMENT
MODELLING
OF PM
FORMING PROCESSES
J. Chen et al. (Chinese Academy of Sciences, Beijing, China.) Powder Technol063: Vol 89, No 2, 1996, 149-155. It is reported that ZrOz and YaO, doped ZrOz had been prepared by solvent extraction from perchloric/nitric acids with tri-n-butyl phosphate. Specific surfaces were 30 to 58m2.gm~’ for ZrOz and 230m2.gm~’ for ZrOz-YzOa.The amount of tetragonal ZrOz decreased with increased pH at precipitation. Powders were of high purity and 10 nm in size.
hai, China.) Z&ns. Non-Ferrous Metals Sot. China, Vol 5, No 3, 1995, 66-70. The use of a general 2-dimensional finite element computer program, S-FORGE, for simulation of dense and porous metal powder preforms is described. The program allows analysis of formation of parts, geometry evaluation and principal variables. Plastic deformation of porous materials can be described.
Fundamentals
Aluminium
MODELLING OF PACKING OF IRREGULARLY SHAPED PARTICLES DISPERSED IN A POLYMER MATRIX
MECHANICAL ALLOYING OF ALUMINIUM-COPPER-VANADIUM AND STRUCTURAL CHANGES
E. Kosior et al. (Royal Melbourne Inst. of Technology, Australia.) Powder Technoloa Vol 89, No 2, 1996, 115-127. The rheological properties of solid particle/polymer mixtures were investigated. Maximum packing fraction of irregular and spherical particles were compared. A model was constructed to predict packing fraction and verified experimentally.
N. Asahi, S. Noguchi. (Science University of Tokyo, Tokyo, Japan.) JJapan Sot. Powder and Powder Metallura Vo142, No 8, 1995, 960-963. (In Japanese.) It is reported that elemental Al15at%Cu- lO%V had been mechanically alloyed in Ar. Alloying, structure and thermal stability on heating were investigated. Amorphization occured after 15 to 30 hours milling. Powder milled for 20 hours recrystallized on heating to 460°C the structure being similar to quenched liquid.
A MEASURE OF THE NUMBER OF
PARTICLES IN AGGLOMERATES R.M. German. (Pennsylvania State University, Pennsylvania, USA) Znt. J. Powder Metallurgy, Vol 32, No 4, 1996, 365-373. The problem of agglomeration at small particle size and the error this causes in particle size measurement is discussed. A parameter to estimate the number of particles during particle size analysis of agglomerates is
Y. Wei, X. Ruan. (Jiatong University, Shang-
Powder and Powder Metallurgv, Vol 42, No 8, 1995, 948-953. (In Japanese.) Combustion synthesis of materials is discussed with reference to Cu matrix composites with intermetallic dispersoids. It is reported that a Cu-TiBz-TiNcomposite had been synthesized from Cu-Ti-BN mixtures. The dispersoids were finely distributed in the Cu alloy matrix.
Iron and steel ADDITIVES TO IMPROVE MACHINABILITY OF SINTERED IRON BASE MATERIALS G. Gengchen. (Metallurgical Industry Pnblishing House, Beijing, China.) R&f Technofogy, Vol 14, No 3, 1996, 225-231. (In Chinese.) Effects of additives on machinability of Fe base alloys are summarized with regard to evaluation of a range of additives including Pb, Bi, Se, Te, MO& MnS and BN. EFFECT OF SINTERING CONDITIONS ON DIMENSIONAL CHANGE IN IRON BASE POWDER COMPACTS J. Takata, N. Kawai. (Kobe Steel Ltd., Takasago, Japan.) J.Japan Sot. Powder and Powder Metal&@, Vol 42, No 7, 1995, 827-832. (In Japanese.) Dimensional changes during sintering of Fe-2wt%Cu-0.8%C-0.75%Zn stearate in endothermic gas and dissociated NH, were compared. Decrease in heating and cooling rates and increase in dew point increased shrinkage by different amounts for the two atmospheres. The shrinkage was blamed on decarburization. DIFFUSION BONDING OF FERROUS COMPACTS DURING SINTERING
Copper
K Asaka. (Hitachi Powdered Metals Co. Ltd., Matsudo, Japan.) JJapan Sot. Powder and Powder Metalk& Vol42, No 8, 1995, 884-890. (In Japanese.) Technological factors in diffusion bonding of ferrous parts during sintering, as opposed to sinter-fit bonding, are outlined. Factors to be noted are said to be thermal expansions of the materials, clearances and fits, effects of alloy elements and part geometry. Applications are discussed.
COMBUSTION SYNTHESIS OF COPPERTITANIUM-BORON NITRIDE COMPOSITES
EFFECT OF FLUX ADDITIONS ON ENHANCEMENT OF SINTERING OF STAINLESS STEEL COMPACTS
H. Tsuda et al. (University of Osaka Prefecture, Sakai, Japan.) J.Japan Sot.
G. Han et al. (Hiroshima University, Higashi-Hiroshima, Japan.) JJapan Sot. Powder MPR June 1997 35
T. Le, H. Henein. (University of Alberta, Edmonton, Canada.) Znt. J. Powder MetalIurgv, Vol 32, No 4, 1996, 353-364. Gas atomization is discussed with reference to process design and conditions. In the study pressure measurements were made at the nozzle tip for different tip designs and the results used to optimize the design. Zn was atomized as a test material and it is reported that a narrow range of particle sizes could be obtained. PRODUCTION OF ULTRAFINE ZIRCONIA POWDERS BY SOLVENT EXTRACTION
introduced. The parameter is for spheres but can be extended to other shapes. It is shown that agglomeration is widespread in many automatic particle size analysers. DISCUSSION OF RADIAL CRUSHING STRENGTH TESTING W. Chonglin. (Metal Research Inst., Academia Sinica, China.) PM Technology, Vol 14, No 3, 1996, 206-211. (In Chinese). Stress distribution during crushing tests on rings is deduced. Tensile stress at the inner surface caused damage similar to bend tests on beams and the magnitude is related to ring dimensions. A relationship for bend strength testing by crushing is proposed. FINITE ELEMENT
MODELLING
OF PM
FORMING PROCESSES
J. Chen et al. (Chinese Academy of Sciences, Beijing, China.) Powder Technol063: Vol 89, No 2, 1996, 149-155. It is reported that ZrOz and YaO, doped ZrOz had been prepared by solvent extraction from perchloric/nitric acids with tri-n-butyl phosphate. Specific surfaces were 30 to 58m2.gm~’ for ZrOz and 230m2.gm~’ for ZrOz-YzOa.The amount of tetragonal ZrOz decreased with increased pH at precipitation. Powders were of high purity and 10 nm in size.
hai, China.) Z&ns. Non-Ferrous Metals Sot. China, Vol 5, No 3, 1995, 66-70. The use of a general 2-dimensional finite element computer program, S-FORGE, for simulation of dense and porous metal powder preforms is described. The program allows analysis of formation of parts, geometry evaluation and principal variables. Plastic deformation of porous materials can be described.
Fundamentals
Aluminium
MODELLING OF PACKING OF IRREGULARLY SHAPED PARTICLES DISPERSED IN A POLYMER MATRIX
MECHANICAL ALLOYING OF ALUMINIUM-COPPER-VANADIUM AND STRUCTURAL CHANGES
E. Kosior et al. (Royal Melbourne Inst. of Technology, Australia.) Powder Technoloa Vol 89, No 2, 1996, 115-127. The rheological properties of solid particle/polymer mixtures were investigated. Maximum packing fraction of irregular and spherical particles were compared. A model was constructed to predict packing fraction and verified experimentally.
N. Asahi, S. Noguchi. (Science University of Tokyo, Tokyo, Japan.) JJapan Sot. Powder and Powder Metallura Vo142, No 8, 1995, 960-963. (In Japanese.) It is reported that elemental Al15at%Cu- lO%V had been mechanically alloyed in Ar. Alloying, structure and thermal stability on heating were investigated. Amorphization occured after 15 to 30 hours milling. Powder milled for 20 hours recrystallized on heating to 460°C the structure being similar to quenched liquid.
A MEASURE OF THE NUMBER OF
PARTICLES IN AGGLOMERATES R.M. German. (Pennsylvania State University, Pennsylvania, USA) Znt. J. Powder Metallurgy, Vol 32, No 4, 1996, 365-373. The problem of agglomeration at small particle size and the error this causes in particle size measurement is discussed. A parameter to estimate the number of particles during particle size analysis of agglomerates is
Y. Wei, X. Ruan. (Jiatong University, Shang-
Powder and Powder Metallurgv, Vol 42, No 8, 1995, 948-953. (In Japanese.) Combustion synthesis of materials is discussed with reference to Cu matrix composites with intermetallic dispersoids. It is reported that a Cu-TiBz-TiNcomposite had been synthesized from Cu-Ti-BN mixtures. The dispersoids were finely distributed in the Cu alloy matrix.
Iron and steel ADDITIVES TO IMPROVE MACHINABILITY OF SINTERED IRON BASE MATERIALS G. Gengchen. (Metallurgical Industry Pnblishing House, Beijing, China.) R&f Technofogy, Vol 14, No 3, 1996, 225-231. (In Chinese.) Effects of additives on machinability of Fe base alloys are summarized with regard to evaluation of a range of additives including Pb, Bi, Se, Te, MO& MnS and BN. EFFECT OF SINTERING CONDITIONS ON DIMENSIONAL CHANGE IN IRON BASE POWDER COMPACTS J. Takata, N. Kawai. (Kobe Steel Ltd., Takasago, Japan.) J.Japan Sot. Powder and Powder Metal&@, Vol 42, No 7, 1995, 827-832. (In Japanese.) Dimensional changes during sintering of Fe-2wt%Cu-0.8%C-0.75%Zn stearate in endothermic gas and dissociated NH, were compared. Decrease in heating and cooling rates and increase in dew point increased shrinkage by different amounts for the two atmospheres. The shrinkage was blamed on decarburization. DIFFUSION BONDING OF FERROUS COMPACTS DURING SINTERING
Copper
K Asaka. (Hitachi Powdered Metals Co. Ltd., Matsudo, Japan.) JJapan Sot. Powder and Powder Metalk& Vol42, No 8, 1995, 884-890. (In Japanese.) Technological factors in diffusion bonding of ferrous parts during sintering, as opposed to sinter-fit bonding, are outlined. Factors to be noted are said to be thermal expansions of the materials, clearances and fits, effects of alloy elements and part geometry. Applications are discussed.
COMBUSTION SYNTHESIS OF COPPERTITANIUM-BORON NITRIDE COMPOSITES
EFFECT OF FLUX ADDITIONS ON ENHANCEMENT OF SINTERING OF STAINLESS STEEL COMPACTS
H. Tsuda et al. (University of Osaka Prefecture, Sakai, Japan.) J.Japan Sot.
G. Han et al. (Hiroshima University, Higashi-Hiroshima, Japan.) JJapan Sot. Powder MPR June 1997 35