Room-temperature compressive deformation behavior of Mg–Zn–Ca alloy processed by equal channel angular pressing

Abstract

The ultra-fine grained (UFG) Mg–5.25 wt.% Zn–0.6 wt.% Ca alloy was processed by equal channel angular pressing (ECAP), and the coarse grained (CG) alloy was prepared by subsequent annealing treatment. The microstructure, texture evolution and mechanical properties of the UFG and CG alloys during compressive deformation at ambient temperature were investigated. The results indicated that the dislocation slip was dominant in the UFG Mg alloy, and the compressive yield stress (CYS) of the UFG alloy was higher than that of the CG alloy due to grain refinement. In the CG Mg alloy, the activation of tension twinning also occurred in addition to basal slip, the work hardening rate was increased because of twin-induced additional hardening. Dynamic recrystallization (DRX) was observed in the CG alloy compressed to large strains at ambient temperature. Most of the {0 0 0 2} planes in both UFG and CG Mg alloys were rotated gradually to be perpendicular to the compressive direction (CD).