Influence of deformation rate on microstructure, texture and mechanical properties of indirect-extruded Mg–Zn–Ca alloy

Abstract

As-cast Mg–5.3Zn–0.6Ca (weight percent) alloy was indirectly extruded at 300°C with different deformation rates (ram speeds of 0.1, 0.3, 0.5mms−1), and the microstructure, texture and mechanical properties of the as-extruded alloys were investigated in the current study. With the increase of deformation rates, the average size and volume fraction of dynamic recrystallized grains were remarkably increased. The basal fiber texture became weak in the as-extruded alloy with higher volume fraction of recrystallized grains, because most of the basal planes in these grains were tilted to extrusion direction about 30–40°. The higher deformation rate decreased the tensile yield stress due to the grain coarsening and basal texture weakening, while the elongation was improved, which was resulted from the enhanced work hardening rate.