Phase Diagram of the Al-Ca-Fe-Si System and Its Application for the Design of Aluminum Matrix Composites

摘要

The phase composition of aluminum alloys in the Al-Ca-Fe-Si system, including the distribution of phases in the solid state and solidification reactions, has been studied. It is shown that the addition of iron and silicon to Al-Ca alloys leads to the formation of ternary Al~(2)CaSi~(2)and Al~(10)CaFe~(2)compounds. The equilibrium between these compounds implies the occurrence of the quaternary L?→?Al?+?Al~(4)Ca?+?Al~(2)CaSi~(2)?+?Al~(10)CaFe~(2)eutectic reaction. The alloys near this eutectic have the best structure, which is typical of aluminum matrix composites. It is shown that Al-Ca alloys can have high manufacturability during both shape casting and rolling. This is due to the combination of a narrow temperature range of solidification and a favorable morphology for the eutectic, which has a fine structure. The combination of the mechanical and physical properties of the Al-Ca eutectic-based alloys significantly exceed those of branded alloys based on aluminum–silicon eutectics.