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New copper powders for electrical brushes and microbearings
Fundamentals
Products: Aluminium
COMPUTER AIDED SIMULATION DIE COMPACTION OF METAL POWDERS
OF
STRUCTURES
AND PROPERTIES
OF
MECHANICALLY ALLOYED ALUMINIUM WITH TRANSITION METAL OXIDES
R.W. Lewis et al (University College, Swansea, UK), Powder Metall, Znt., Vol 25, No 6, 1993, 287-293. A computer simulation of die compaction of metal powders is described. Finite element analysis is used to describe mechanical behaviour. A model in which equations are modified using experimental data are used to describe rheological behaviour taking friction into account. Results for parts with variable crosssection are presented. Numerical and experimental results are reported to agree.
J. Kaneko et al (Nihon University, Narashino, Japan), J. Japan Inst. of Metals, (Vol 57, No 11, 1993, 1325-1332. (In Japanese). A study of Al with dispersions of V, Nb or Ta oxides, introduced by MA with C and CHsOH, followed by hot pressing and heat treatment, is described. Reactions between Al and C and the oxides were investigated. Oxides were reduced and Al&s was formed giving a dispersion of ALzOa together with aluminides after heating.
PRESSING
NOTCH TOUGHNESS OF ALUMINIUMSILICON CARBIDE COMPOSITES
PRODUCTION STRUCTURES
FOR
OF FAULT FREE IN SINTERED
MATERIALS
D. Kwon et al (Pohang Inst. of Science and Technology, Pohang, Korea), J. Korean Inst. S.B. Zubro Poroshkovaya Metallurgiya, of Metals, Vol 31, No 6, 1993, 739-747. No 8, 1993, 33-37. (In Russian). (In Korean). The sintering of materials without large An investigation of the structure and pores was investigated. It was shown properties of 2124 and 2009 Al alloys theoretically that this should be possible reinforced with Sic whiskers is described. and was demonstrated experimentally. It is reported that the 2009 alloy composite Relationships with inclusions were showed improved fracture toughness. Alloys studied. A production technique is were tested under a range if conditions. described. . Cracking of the whiskers and decohesion at the matrix/whisker interface are shown to be the main causes of fracture. Quality assurance and
quality control
IS0
Copper
9000 AND ITS IMPACT IN THE
POWDER METALLURGY
INDUSTRY
M.K. Tarby (Metal Powder Industries Federation, Princeton, New Jersey, USA), Znt. J. Powder Metallurgy, Vol 30, No 2, 1994, 185-196. Purpose, direction and costs are considered in a review of the application of IS0 9000, which is not yet universally adopted, in quality assurance and control systems. The importance of IS0 9000 in the Automotive Industry Harmonised Standard is emphasized since it is standard for assessment of quality systems and not products. The component parts IS0 9001 to 9003 are discussed as these are related to organizational matters which are examined by external assessors on registration in the scheme. Impact in the PM industry is discussed.
62
MPR December
1994
Iron and steel EFFECT OF TEMPERING TEMPERATURE ON MACHINABILI’I AND FATIGUE IN HIGH STRENGTH STEEL
EFFECTSOFMICROSTRUCTUREON CONDITIONS
The development of a new Cu pov with high specific surface, low appa density and the ability to maintain a matrix at higher %C giving incre; electrical conductivity, for productiol Cu-C brushes, is reported. A low n bronze bearing alloy, made from pre-all powder, is shown to have a uniform a Sn structure, fine pore size from w microbearings can be produced to c dimensional tolerances.
RECENT FERROUS
DEVELOPMENTS
IN NON-
POWDERS
W.J. Ullrich et al (Alcan Powders and Pigments, Union, New Jersey, USA), Znt. J. Powder Metallurgy, Vol 30, No 2, 1994, 179-184. A review of recent development in Cubase powders is presented. Bronze premixes, forging grade Cu powder and lead-free brass powders are considered. NEW COPPER POWDERS FOR ELECTRICAL BRUSHES AND MICROBEARINGS
G.M. Rankinen, D.F. Berry (SCM Metal Products Inc., North Carolina, USA), Znt. J. Powder Metallurgy, Vol 30, No 2, 1994, 173-178.
K Lipp et al (Fraunhofer Inst., Darmst Germany), Powder Metall. Znt., Vol No 6, 1993, 261-266. Fatigue properties and machinabilil sintered prealloyed 1.75%Ni-1.5% 0.5%Mo steel powder with 0.5% 0.5%MnS, at a density of 7.1 gm/cm3, 1 investigated in hardened and tempt conditions. Optimum temper temperature, relative to machinability fatigue properties, is reported to be 30 The steel is considered to be suitable notched components. CREEP OF SINTERED
PURE AND
ALLOYED IRON AT ROOM TEMPERATURE
S. Klumpp, E. Macherauch (Techn University, Karlsruhe, Germany) Pou Metall. Znt., Vol 25, No 6, 1993, 267-25 It is reported that creep occurs at r( temperature in pure Fe, Fe-1.5%wt%Cu, 0.45%P and Fe-1.5%Cu-O.G%C at stre: below the 0.2% proof stress. This attributed to microplastic deformai and crack opening effects. Liquid pl sintering is reported to improve CI opportunities. FRACTURE SURFACE MORPHOLOG’ AND COMPOSITION OF SINTERED STEELS
J. Karwan-Baczewska, A Karamara (I versity of Mining and Metallurgy, Crak Poland), Powder Metall. Znt., Vol 25, Nc 1993, 271-274. An investigation of the effects of %C mechanical properties and fracture surf
Products: Aluminium
COMPUTER AIDED SIMULATION DIE COMPACTION OF METAL POWDERS
OF
STRUCTURES
AND PROPERTIES
OF
MECHANICALLY ALLOYED ALUMINIUM WITH TRANSITION METAL OXIDES
R.W. Lewis et al (University College, Swansea, UK), Powder Metall, Znt., Vol 25, No 6, 1993, 287-293. A computer simulation of die compaction of metal powders is described. Finite element analysis is used to describe mechanical behaviour. A model in which equations are modified using experimental data are used to describe rheological behaviour taking friction into account. Results for parts with variable crosssection are presented. Numerical and experimental results are reported to agree.
J. Kaneko et al (Nihon University, Narashino, Japan), J. Japan Inst. of Metals, (Vol 57, No 11, 1993, 1325-1332. (In Japanese). A study of Al with dispersions of V, Nb or Ta oxides, introduced by MA with C and CHsOH, followed by hot pressing and heat treatment, is described. Reactions between Al and C and the oxides were investigated. Oxides were reduced and Al&s was formed giving a dispersion of ALzOa together with aluminides after heating.
PRESSING
NOTCH TOUGHNESS OF ALUMINIUMSILICON CARBIDE COMPOSITES
PRODUCTION STRUCTURES
FOR
OF FAULT FREE IN SINTERED
MATERIALS
D. Kwon et al (Pohang Inst. of Science and Technology, Pohang, Korea), J. Korean Inst. S.B. Zubro Poroshkovaya Metallurgiya, of Metals, Vol 31, No 6, 1993, 739-747. No 8, 1993, 33-37. (In Russian). (In Korean). The sintering of materials without large An investigation of the structure and pores was investigated. It was shown properties of 2124 and 2009 Al alloys theoretically that this should be possible reinforced with Sic whiskers is described. and was demonstrated experimentally. It is reported that the 2009 alloy composite Relationships with inclusions were showed improved fracture toughness. Alloys studied. A production technique is were tested under a range if conditions. described. . Cracking of the whiskers and decohesion at the matrix/whisker interface are shown to be the main causes of fracture. Quality assurance and
quality control
IS0
Copper
9000 AND ITS IMPACT IN THE
POWDER METALLURGY
INDUSTRY
M.K. Tarby (Metal Powder Industries Federation, Princeton, New Jersey, USA), Znt. J. Powder Metallurgy, Vol 30, No 2, 1994, 185-196. Purpose, direction and costs are considered in a review of the application of IS0 9000, which is not yet universally adopted, in quality assurance and control systems. The importance of IS0 9000 in the Automotive Industry Harmonised Standard is emphasized since it is standard for assessment of quality systems and not products. The component parts IS0 9001 to 9003 are discussed as these are related to organizational matters which are examined by external assessors on registration in the scheme. Impact in the PM industry is discussed.
62
MPR December
1994
Iron and steel EFFECT OF TEMPERING TEMPERATURE ON MACHINABILI’I AND FATIGUE IN HIGH STRENGTH STEEL
EFFECTSOFMICROSTRUCTUREON CONDITIONS
The development of a new Cu pov with high specific surface, low appa density and the ability to maintain a matrix at higher %C giving incre; electrical conductivity, for productiol Cu-C brushes, is reported. A low n bronze bearing alloy, made from pre-all powder, is shown to have a uniform a Sn structure, fine pore size from w microbearings can be produced to c dimensional tolerances.
RECENT FERROUS
DEVELOPMENTS
IN NON-
POWDERS
W.J. Ullrich et al (Alcan Powders and Pigments, Union, New Jersey, USA), Znt. J. Powder Metallurgy, Vol 30, No 2, 1994, 179-184. A review of recent development in Cubase powders is presented. Bronze premixes, forging grade Cu powder and lead-free brass powders are considered. NEW COPPER POWDERS FOR ELECTRICAL BRUSHES AND MICROBEARINGS
G.M. Rankinen, D.F. Berry (SCM Metal Products Inc., North Carolina, USA), Znt. J. Powder Metallurgy, Vol 30, No 2, 1994, 173-178.
K Lipp et al (Fraunhofer Inst., Darmst Germany), Powder Metall. Znt., Vol No 6, 1993, 261-266. Fatigue properties and machinabilil sintered prealloyed 1.75%Ni-1.5% 0.5%Mo steel powder with 0.5% 0.5%MnS, at a density of 7.1 gm/cm3, 1 investigated in hardened and tempt conditions. Optimum temper temperature, relative to machinability fatigue properties, is reported to be 30 The steel is considered to be suitable notched components. CREEP OF SINTERED
PURE AND
ALLOYED IRON AT ROOM TEMPERATURE
S. Klumpp, E. Macherauch (Techn University, Karlsruhe, Germany) Pou Metall. Znt., Vol 25, No 6, 1993, 267-25 It is reported that creep occurs at r( temperature in pure Fe, Fe-1.5%wt%Cu, 0.45%P and Fe-1.5%Cu-O.G%C at stre: below the 0.2% proof stress. This attributed to microplastic deformai and crack opening effects. Liquid pl sintering is reported to improve CI opportunities. FRACTURE SURFACE MORPHOLOG’ AND COMPOSITION OF SINTERED STEELS
J. Karwan-Baczewska, A Karamara (I versity of Mining and Metallurgy, Crak Poland), Powder Metall. Znt., Vol 25, Nc 1993, 271-274. An investigation of the effects of %C mechanical properties and fracture surf