Microstructure and mechanical property of Mg–8.31Gd–1.12Dy–0.38Zr alloy

The Mg–8.31Gd–1.12Dy–0.38Zr (mass%) alloy was prepared by casting technology, and the microstructure, age hardening behavior and mechanical property have been investigated. It is noted that the α-Mg and the different Mg-RE (RE = Gd/Dy) compounds are subsistent in the as-cast and annealed state samples. The age hardening behavior is observed during the investigated temperature range, and the alloy exhibits high Vickers hardness, excellent ultimate tensile strength and yield strength at peak hardness. The peak hardness and time of reaching peak hardness decrease with the increase of aging temperature. The high mechanical property is mainly attributed to the dispersed fine β′-Mg15RE3 and β-Mg5RE precipitates.