Enhanced age-hardening response and mechanical properties of the Mg-Gd-Y-Zn-Zr alloy by trace Ag addition

In the present study, we have systematically investigated how the influence of silver (Ag) addition (0.3 wt%) on the microstructural and mechanical properties of Mg-6Gd-3Y-1Zn-0.4Zr (wt%) alloy. The results indicate that the Ag addition enhances the age-hardening response, especially at the early stage of aging. The improved age-hardening response of the alloy is associated with dense nanosized basal γ'' precipitates formed upon the Ag addition and the β’ phase. Furthermore, the presence of Ag also improves the tensile properties of the peak-aged alloy. The Ag-containing alloy exhibits higher ultimate tensile strength, yield strength, and elongation to failure than the Ag-free alloy at room and elevated temperatures. We suggest that the improved strength and ductility of the Ag-containing alloy originate from the coprecipitation of the nanosized basal γ'' precipitates and the β’ phase.