Observation of Al-1%Mg₂Si alloy based alumina particles dispersed composite materials by analytical transmission electron microscope

Effects of aging treatment on Al-1%Mg₂Si-alumina particles dispersed composite materials were investigated by the observation of analytical transmission electron microscope and electrical resistivity measurement. An ability of age hardening is remarkably decreased by addition of 4% alumina particles as compared with that of Al-1%Mg₂Si alloy. When volume fraction of alumina particles is increased up to 20%, age hardenability is not obtained more. The lack of hardening in the matrices of the composite should be attributed to the decrease in β′ precipitates. The spinels are observed at composite materials and they show often twin structure.