Microstructure and mechanical properties of Mg–4.0Zn–0.5Ca alloy

Abstract

A new kind of Mg–4.0 wt.%Zn–0.5 wt.%Ca alloy is fabricated by casting and hot extrusion for used as a high performance structure material as well as a biomaterial. In the as-cast alloy, the average grain size of the α-Mg is 120–150 µm and the precipitated second phases are distributed uniformly in α-Mg grains. The as-cast Mg–4.0 wt.%Zn–0.5 wt.%Ca alloy shows a good balance between the tensile strength (211 MPa) and ductility (17% in elongation). After hot extrusion at 593 K, the second phase is greatly refined and the average grain size of the α-Mg is reduced to 8–12 μm which is resulted from dynamic re-crystallization during hot extrusion. In this case, it exhibits a high tensile strength (273 MPa) and a high ductility (34% in elongation) at room temperature.