Effect of Annealing Before Aging on Microstructure and Mechanical Properties of Mg-Gd-Y-Zn-Zr Alloy

In this study, in order to improve the elongation of Mg-9Gd-4Y-2Zn-0.5Zr alloy after aging, annealing treatment was introduced before aging. The alloy billet was subjected to 2 passes of cyclic expansion–extrusion with an asymmetrical cavity (CEE-AEC), then annealed and aged. Static recrystallization occurred during annealing, and the microstructure was refined. After annealing, the elongation of the sample reached the maximum, which is 7.4%, and the peak aging lagged due to dislocation consumption. Compared with the direct aging samples with the lowest elongation, aging after annealing could obtain more comprehensive mechanical properties. The ultimate tensile strength (UTS) was 362 MPa, and the elongation was 2.1%.