Effect of ageing treatment on the microstructure, texture and mechanical properties of extruded Mg-8.2Gd-3.8Y-1Zn-0.4Zr (wt%) alloy

Extruded Mg-8.2Gd-3.8Y-1Zn-0.4Zr (wt%) alloy was subjected to ageing treatment at 200. °C. The microstructures, textures and mechanical properties of the as-extruded and peak-aged alloys were investigated. Recrystallization occurred during ageing treatment. A large number of Β' phases were observed in the peak-aged alloy, accompanied with the decrease of the volume fraction of LPSO phases. A basal fiber texture and an unusual texture component with basal planes perpendicular to the extrusion direction were found in the as-extruded alloy, and the basal fiber texture was strengthened after ageing treatment. The peak-aged alloy exhibited a tensile yield strength (TYS), an ultimate tensile strength (UTS) and an elongation to failure of 395. MPa, 470. MPa and 8%, respectively, at ambient temperature, and 271. MPa, 311. MPa and 19%, respectively, at 300. °C. The superior strength of the peak-aged alloy was mainly attributed to the precipitation of fine Β' phases, the remaining LPSO phases and the texture modification.