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Development of high strength PM Al Alloys
Literature AG, Bonn, Germany), Metall, Vol 44, No 6, 1990, 532-539, (in German).
PROPERTIES OF HIGH STRENGTH PM AI ALLOY ROLLED SHEET Y Suzuki, et al, J Japan Soc. Powder and Powder Metallurgy, Vol 37, No 3, 1990, 445--450, (in Japanese). Sheet of A1-6.5% Zn-2.6%Mg-l.6%Cu0.4%Co was rolled from sintered compacts produced from (a) elemental and (b) prealloyed powders in different proportions. Susceptibility to cracking varied according to the powder mix used. Cracking was least common in the alloy made from AI-0.5%Co with elemental powders. Tensile strengths up to 5 9 0 MPa and 11% elongation were measured. Sintering at 863 K gave residual H2 less than 2 ppm.
Wrought A1-Zn-Mg-Cu with Zr and Mn prepared from rapidly solidified (RS) powder. Increased strength said to be caused by precipitation of ZnMg2Cu, with further increase resulting from a fine dispersion of A13Zr and A16Mn and a fine grain structure.
ELEVATED TEMPERATURE PROPERTIES OF AI-AI4C3 M Shlesar, et al, Poroskovaya Metallurgia, 1990, No 11, 76-82, (in Russian). Mechanical properties of A1-5vol% A14C3 were measured in the range 100-4000C. Strength was said to be retained in this range. Deformation processes were analysed and fracture mechanisms determined.
DEVELOPMENT OF HIGH STRENGTH FERROUS SINTERED STRUCTURAL PARTS T Tabata, (Tokyo Sintered Metals Corp), J.
Japan Soc. Powder and Powder Metallurgy, Vol 37, No 3, 1990, 391-397, (in Japanese). Production of improved sintered metals with increased tensile strength, in excess of ll0N/mm2, shown to be possible by high density compaction, high temperature sintering and controlled heat treatment using high compressibility partially alloyed powders. Production of alloys with high toughness and wear resistance is described.
LASER HARDENING OF STEEL B J Fernandez, et al, (Cenim. Madrid, Spain),
Revista de Metallurgia, Vol 26, No 1, 1990, 17-25, (in Spanish).
MICROSTRUCTURE AND MECHANICAL PROPERTIES OF PM AI-Fe-V-Si ALLOY J-C Lee, et al, (Pohang Inst. of Science and Technology, Pohang, Korea) J. Korean Inst. of Metals, Vol 28, No 4, 1990, 350-359, (in Korean). The main factor leading to the embrittlement of RSP/PM A1-Fe-V-Si alloy after heating at temperatures above 480°C is established as formation of a banded structure of A13Fe, Formation of a non-uniform dispersion of silicides is also observed. The importance of microstructural control is emphasised. MECHANISM OF FRACTURE OF AN RSP/PM A1-3.5 %Fe-l.3 %V-1.7 %Si ALLOY J-C Lee, et al, (Pohang Inst. of Science and technology, Pohang Korea), J. Korean Inst. of Metals, Vol 28, No 4, 1990, 360-365, (in Korean). Fracture of the alloy was investigated. Specimens heated in range 150-4800C for 100 hours. Room temperature tensile fracture toughness and void initiationtests were carried out. At temperatures up to 425°C room temperature properties little changed but were reduced significantly after heating at 480°C. DEVELOPMENT OF HIGH STRENGTH PM AI ALLOYS J Mathy, et al, (Vereingte Aluminium-Werke
720
A mathematical model of laser heating is given which allows calculation of hardening effects in steel. Applications are discussed. STRUCTURE AND PROPERTIES OF HEAT TREATED PM ALLOYS MADE FROM POWDERS DERIVED FROM CAST IRON CHIPS A T Mamadov, A A Guliev, Poroskovaya Metallurgia, 1990, No 1, 47-53, (in Russian). The effect of hardening and tempering conditions on structure and properties of PM steels was studied. It was shown that hardening from 800"C does not result in redistribution of the C atoms. A sufficiently homogeneous structure is obtained on quenching from 900"C. Optimum tempering temperature is 250°C. Quenching from 1000°C leads to overheating although homogeneity increases.
CRACK RESISTANCE AND STRENGTH OF CARBIDE STEELS
MICROSTRUCTURE OF RAPIDLY SOLIDIFIED (RS) MARAGING STEEL POWDERS X Duan, R Yang, (University of Science and Technology, Beijing, China), Iron and Steel (China), Vol 23, No 12, 1988, 53-57, (in Chinese). Surface morphology and microstructure of RS maraging steel powder produced by N2 atomization and centrifugal atomization (CA) was examined by optical microscopy and SEM.
STRUCTURE OF Fe-FeO INTERFACE BY HIGH RESOLUTION ELECTRON MICROSCOPY
1990, No 1, 90-94, (in Russian).
K Saloata, K Ogawa, (Science University of Tokyo, Japan), J. Japan Inst. of Metals,, Vol 54, No 4, 1990, 357-361, (in Japanese).
Crack resistance of steels with an austenitic or austenitic-martensitic matrix and carbides was measured. Crack resistances compare unfavourably with WC hard alloys with a similar matrix volume. Relationships between crack resistance and other mechanical properties were examined.
The structure of the Fe-FeO interface in a sintered PM compact containing 30mol%FeO studied by Auger analysis X-ray photoelectron spectroscopy. A transition region with oxygen deficiency observed, due to diffusion of oxygen into the Fe phase, said to be of significance in adhesion.
E P Zhelibo, et al, Poroskovaya Metallurgia,
MPR October 1990
PROPERTIES OF HIGH STRENGTH PM AI ALLOY ROLLED SHEET Y Suzuki, et al, J Japan Soc. Powder and Powder Metallurgy, Vol 37, No 3, 1990, 445--450, (in Japanese). Sheet of A1-6.5% Zn-2.6%Mg-l.6%Cu0.4%Co was rolled from sintered compacts produced from (a) elemental and (b) prealloyed powders in different proportions. Susceptibility to cracking varied according to the powder mix used. Cracking was least common in the alloy made from AI-0.5%Co with elemental powders. Tensile strengths up to 5 9 0 MPa and 11% elongation were measured. Sintering at 863 K gave residual H2 less than 2 ppm.
Wrought A1-Zn-Mg-Cu with Zr and Mn prepared from rapidly solidified (RS) powder. Increased strength said to be caused by precipitation of ZnMg2Cu, with further increase resulting from a fine dispersion of A13Zr and A16Mn and a fine grain structure.
ELEVATED TEMPERATURE PROPERTIES OF AI-AI4C3 M Shlesar, et al, Poroskovaya Metallurgia, 1990, No 11, 76-82, (in Russian). Mechanical properties of A1-5vol% A14C3 were measured in the range 100-4000C. Strength was said to be retained in this range. Deformation processes were analysed and fracture mechanisms determined.
DEVELOPMENT OF HIGH STRENGTH FERROUS SINTERED STRUCTURAL PARTS T Tabata, (Tokyo Sintered Metals Corp), J.
Japan Soc. Powder and Powder Metallurgy, Vol 37, No 3, 1990, 391-397, (in Japanese). Production of improved sintered metals with increased tensile strength, in excess of ll0N/mm2, shown to be possible by high density compaction, high temperature sintering and controlled heat treatment using high compressibility partially alloyed powders. Production of alloys with high toughness and wear resistance is described.
LASER HARDENING OF STEEL B J Fernandez, et al, (Cenim. Madrid, Spain),
Revista de Metallurgia, Vol 26, No 1, 1990, 17-25, (in Spanish).
MICROSTRUCTURE AND MECHANICAL PROPERTIES OF PM AI-Fe-V-Si ALLOY J-C Lee, et al, (Pohang Inst. of Science and Technology, Pohang, Korea) J. Korean Inst. of Metals, Vol 28, No 4, 1990, 350-359, (in Korean). The main factor leading to the embrittlement of RSP/PM A1-Fe-V-Si alloy after heating at temperatures above 480°C is established as formation of a banded structure of A13Fe, Formation of a non-uniform dispersion of silicides is also observed. The importance of microstructural control is emphasised. MECHANISM OF FRACTURE OF AN RSP/PM A1-3.5 %Fe-l.3 %V-1.7 %Si ALLOY J-C Lee, et al, (Pohang Inst. of Science and technology, Pohang Korea), J. Korean Inst. of Metals, Vol 28, No 4, 1990, 360-365, (in Korean). Fracture of the alloy was investigated. Specimens heated in range 150-4800C for 100 hours. Room temperature tensile fracture toughness and void initiationtests were carried out. At temperatures up to 425°C room temperature properties little changed but were reduced significantly after heating at 480°C. DEVELOPMENT OF HIGH STRENGTH PM AI ALLOYS J Mathy, et al, (Vereingte Aluminium-Werke
720
A mathematical model of laser heating is given which allows calculation of hardening effects in steel. Applications are discussed. STRUCTURE AND PROPERTIES OF HEAT TREATED PM ALLOYS MADE FROM POWDERS DERIVED FROM CAST IRON CHIPS A T Mamadov, A A Guliev, Poroskovaya Metallurgia, 1990, No 1, 47-53, (in Russian). The effect of hardening and tempering conditions on structure and properties of PM steels was studied. It was shown that hardening from 800"C does not result in redistribution of the C atoms. A sufficiently homogeneous structure is obtained on quenching from 900"C. Optimum tempering temperature is 250°C. Quenching from 1000°C leads to overheating although homogeneity increases.
CRACK RESISTANCE AND STRENGTH OF CARBIDE STEELS
MICROSTRUCTURE OF RAPIDLY SOLIDIFIED (RS) MARAGING STEEL POWDERS X Duan, R Yang, (University of Science and Technology, Beijing, China), Iron and Steel (China), Vol 23, No 12, 1988, 53-57, (in Chinese). Surface morphology and microstructure of RS maraging steel powder produced by N2 atomization and centrifugal atomization (CA) was examined by optical microscopy and SEM.
STRUCTURE OF Fe-FeO INTERFACE BY HIGH RESOLUTION ELECTRON MICROSCOPY
1990, No 1, 90-94, (in Russian).
K Saloata, K Ogawa, (Science University of Tokyo, Japan), J. Japan Inst. of Metals,, Vol 54, No 4, 1990, 357-361, (in Japanese).
Crack resistance of steels with an austenitic or austenitic-martensitic matrix and carbides was measured. Crack resistances compare unfavourably with WC hard alloys with a similar matrix volume. Relationships between crack resistance and other mechanical properties were examined.
The structure of the Fe-FeO interface in a sintered PM compact containing 30mol%FeO studied by Auger analysis X-ray photoelectron spectroscopy. A transition region with oxygen deficiency observed, due to diffusion of oxygen into the Fe phase, said to be of significance in adhesion.
E P Zhelibo, et al, Poroskovaya Metallurgia,
MPR October 1990