Cast composite material from Al-Mg-Sr-Matrix with aluminium oxide reinforcement.

摘要

A cast composite material having little spinel therein is formed from a mixture having a composition of from about 5 to about 35 volume percent of aluminum oxide reinforcing particles and from about 95 to about 65 volume percent of a molten matrix alloy. The matrix alloy is an aluminum-based alloy containing from about 0.15 to about 3 weight percent magnesium and a sufficient amount of strontium to reduce or entirely suppress spinel formation. The strontium content is from about 0.1 to about 2 weight percent of the matrix alloy. This composition is mixed to wet the matrix alloy to the particles and to distribute the particles throughout the volume of the molten matrix, while minimizing the introduction of gas into and retention of gas within the mixture. The wetted mixture is cast into molds or forms.