An Extruded and Peak Aged Mg-5Gd-3Y-1Zn-Zr Alloy with High Strength

This article presents an extruded Mg-5Gd-3Y-1Zn-Zr alloy produced by conventional ingot metallurgy, exhibiting high-strength and excellent ductility at room and elevated temperatures, with a low density of 1.84g/cm3. The 0.2% yield strength (YS), ultimate tensile strength (UTS)and elongation-to-failure (EL)at room temperature, of samples in T5 condition, can reach 324MPa, 382MPa and 9.3%, respectively. At 250°C, the UTS can be still higher than 317MPa, with EL of 21%. The excellent mechanical properties were attributed to the high density of the static aging prismatic precipitates in the matrix, dynamic β phase precipitated on the dynamic recrystallization grain boundaries, and bimodal grain size distribution with fine recrystallized grains and large deformed grains with intense basal texture and LPSO phase inside the grain.