Effects of Zn addition on the mechanical properties and texture of extruded Mg-Zn-Ca-Ce magnesium alloy sheets

Abstract

Mg-x Zn-0.2Ca-0.2Ce (x = 0.5, 1.0, 1.5 and 2.0, wt%) alloys were subject to hot extrusion, for the purpose of evaluating the effects of Zn addition on the mechanical properties and texture characteristics in this current paper. A spread of basal poles in extrusion direction (ED) was found in all four extruded alloys, beyond that, the rare earth texture component existed in the alloys. It is interesting that both the ED-split texture and rare earth texture components reduced with the increasing Zn addition; furthermore, the increasing Zn addition leaded to a broader spread of basal poles toward transverse direction (TD). Both the strength and plasticity were improved with the increasing Zn addition, by solid solution hardening, solid solution softening, and the enhanced cohesion of grain boundaries; while further Zn addition deteriorated the plasticity, because of the dominant solid solution hardening. Mg-Zn-Ca-Ce magnesium alloys received the best comprehensive mechanical properties when Zn addition reached 1.5wt%, with tension yield strength (TYS) and tension fracture elongation (TFE) about 131.0MPa and 42.4%, respectively, in ED.