Microstructure and properties of AZ31 alloy by static recrystallisation at lower temperature

Abstract

The microstructure evolution and mechanical properties of AZ31 Mg sheets that was processed by rolling and subsequent annealing at lower temperature were investigated. The results indicated that few-pass rolling with large deformation is a better strategy to prepare AZ31 Mg sheets with higher deformation restored energy and less rolling defects. After annealing, the static recrystallisation occurred and the recrystallisation degree increases with the annealing temperature and time. Finally, the best comprehensive mechanical properties were obtained by 3-pass rolling with large deformation and annealing at 200 °C for 150 s and the corresponding YS, UTS and TEF of the AZ31 sheet were 225 MPa, 305 MPa and 32%, respectively. The improvement in the microstructure and mechanical properties can be attributed to an optimised static recrystallisation at a relatively low temperatures and in a short time.