Effect of Ag addition on the elevated-temperature mechanical properties of an extruded high strength Mg–Gd–Y–Zr alloy

Abstract

Elevated-temperature mechanical properties of the extruded Mg–8.5Gd–2.5Y–0.5Zr (wt%) and Mg–8.5Gd–2.5Y–0.5Zr–2Ag (wt%) alloys were investigated by the shear punch test (SPT) in the temperature range of 25–300°С. The average sizes of the dynamically recrystallized grains of the Ag-free and Ag-containing alloys were about 8 and 3µm, respectively. Addition of Ag to the base alloy led to the formation of a new intermetallic phase with a composition close to Mg16Gd2YAg, and increased the volume fraction of the second phase particles from 2.5% to about 13%. This together with the refinement of microstructure resulted in superior mechanical properties of the Ag-containing alloy over the base material in the whole temperature range studied.