High-strength and good-ductility Mg–RE–Zn–Mn magnesium alloy with long-period stacking ordered phase

Abstract The microstructure and mechanical properties of Mg–8.40Gd–5.30Y–1.65Zn–0.59Mn (wt%) alloy were investigated in this study. The phase composition of the alloy involved an α-Mg matrix and long-period stacking ordered phases of Mg 12 Zn(Y,Gd) with some eutectic phases. After aging at 200 °C for 50 h following extrusion (extrusion ratio= 11:1, extrusion temperature=400 °C), the alloy achieved high strength (ultimate tensile strength=∼500 MPa, tensile yield strength=∼322 MPa) and good ductility (elongation=∼10.0%) and exhibited excellent comprehensive mechanical properties. These properties could be attributed to the numerous plate-shaped β′ phase precipitates in the α-Mg matrix, as well as the small dispersed block-shaped long-period stacking ordered phases along the grain boundaries.