High-temperature deformation behavior of aluminum alloys produced from centrifugally-atomized powders

Abstract

Powder metallurgy (P/M) aluminum alloys have been expected to have extended application in the production of such items as automobile, aeroplane and machine parts. P/M AlAl10mass%Mg and hyper-eutectic AlSi alloys have been produced using a centrifugal-atomization process, which is one of the rapid-solidification techniques, and the possibility of superplastic deformation has been investigated because the components required have become of more complicated shape. The ductility of the P/M alloys has been examined with respect to the effects of the test temperature, the strain rate and the consolidation process of the powders. P/M Al10Mg and AlSi alloys exhibit superplastic-like deformation behavior, and the optimum strain rate showing the maximum elongation is relatively high, 10 −1−10 0 s −1 for the Al-10Mg alloy. The maximum elongations of the P/M Al25Si and Al15Si alloys are more than 150 and 300%, respectively. The P/M AlSi alloys show the maximum elongation at temperatures very close to the each solidus temperature of the alloys. A fibrously-elongated microstructure is formed on the whole surfaces of the P/M AlSi alloys under the optimum condition of superplastic deformation.