Creep deformation mechanisms in coarse-grained solid solution Mg alloys

Abstract

Creep deformation behavior of coarse-grained Mg-Al based solid solution alloy (AZ31) was studied in a wide strain rate range of 2 × 10 -5∼7 × 10-2 s-1 at temperature range of 573-673 K. Viscous glide controlled creep (VGC), dislocation climb creep (DCC) and power law breakdown (PLB) showed up in order with increasing stress as the flow rate-controlling process. From the former results for Mg-Al and Mg-Al-Zn alloys, the creep mechanisms of VGC and DCC in Mg and Mg alloys are confirmed. Moreover, several theories presented for DCC and VGC are applied to convey the creep mechanisms in Mg and Mg alloys by analytical way. Transitions in Mg alloys are analyzed also by comparing experimental results and theories. Alloying effects on creep strength and transitions of deformation mechanism are analyzed.