Microstructure and Creep Property of As-Cast Mg-6Al-<i>X</i>Sr(<i>x</i>=0, 2, 3) Alloys

Abstract

The microstructure and creep property of as-cast Mg-6Al-xSr(x=0, 2,3) alloys were studied. Results showed that the branch-like Al4Sr phase is the main precipitating phase in these alloys containing Sr. Their secondary creep rates under the applied stress of 70MPa at 175°Cdecreased with the increasing in the content of Sr and reached the minimum value of 1.4×10-8s-1in the Mg-6Al-3Sr alloy, which is one thirtieth of secondary creep rates of the Mg-6Al alloy. It was mainly attributed to Al4Sr, which effectively hindered the grain boundaries sliding and dislocation motion in the creep.