Effects of processing parameters and Ca content on microstructure and mechanical properties of squeeze casting AZ91-Ca alloys

摘要

AZ91-(1-3 wt%) Ca alloys were prepared by direct squeeze casting, in which the melt was solidified under applied pressure. The effects of processing parameters (such as applied pressure and pouring temperature) and Ca content on microstructure and mechanical properties of squeeze casting AZ91-Ca alloys were investigated. The results indicate that the microstructure was refined with the increase of applied pressure, and the mechanical properties were improved. When the pouring temperature was lowered down to near the liquidus, the microstructure was further refined and α-Mg grains turned rosette-like. The negative effect on ambient temperature mechanical properties caused by the addition of Ca into AZ91 alloy was inhibited by squeeze casting. Compared to conventional casting, squeeze casting process can offer AZ91-Ca alloys better mechanical properties, especially in elongation to failure (E_f).