EFFECT OF SB AND SR ADDITIONS ON THE MICROSTRUCTURAL EVOLUTION OF MG-SN-AL-SI BASED ALLOYS

Abstract

A study has been made on the effect of Sb and Sr on the microstructure and mechanical properties of Mg-Sn-Al-Si based (TAS) alloy. When Sb is added to TAS alloy, the morphology of second phase particles changes to fine radial shape by the formation of nucleation cores. Refined microstructure of TAS-Sb alloys results in higher yield strength and larger elongation with lower creep resistance than those of TAS alloy. Sr addition induces the formation of large amount of thermally stable second phase particles. Due to the large amount of thermally stable second phase particles, TAS-Sr alloys show superior creep resistance and higher yield strength at both room and high temperatures than those of TAS alloy.