Microstructure and mechanical properties of extruded Mg–8.5Gd–2.3Y–1.8Ag–0.4Zr alloy

The microstructure, age hardening behavior and mechanical properties of an Mg–8.5Gd–2.3Y–1.8Ag–0.4Zr alloy prepared by casting and hot extrusion techniques were investigated. The solution-treated (T4 temper) alloys were extruded at 400, 450 and 500 °C with an extrusion ratio of 10:1, respectively. Optimized mechanical properties were obtained by extrusion at 400 °C followed by T5 treatment under the combined effects of grain refinement and precipitation strengthening. The alloy exhibits a grain size of about 5.0 μm, initial and peak microhardness of HV 109 and HV 129, respectively. The tensile yield strength, ultimate tensile strength and elongation at room temperature are 391 MPa, 430 MPa and 5.2%, respectively.