Influence of temperature and cumulative strain on microstructure and mechanical properties of multi-directional forged Mg-Gd-Y-Zn-Zr alloy

Abstract

The multidirectional forging (MDF) experiments of Mg-Gd-Y-Zn-Zr alloy were performed. The effects of temperature and cumulative strain on microstructure and mechanical properties of multi-directional forged Mg-Gd-Y-Zn-Zr alloy were studied. The results showed that the recrystallization ratio of the alloy gradually increased with the initial forging temperature after 3 passes of MDF. Under the condition of the initial forging temperature of 500 °C, the grain size was gradually refined with increasing MDF passes, and the average grain size was refined to 1.49 μm after 12 MDF passes. With the increase in MDF passes, the maximum texture density of the alloy gradually decreased. The mechanical properties gradually increased with the MDF passes. In the first 6 MDF passes, the mechanical properties greatly increased, but after that, the increase gradually slowed down with additional MDF passes. The optimal mechanical properties were obtained after 12 MDF passes, and the tensile strength, yield strength, and elongation after fracture were 362 MPa, 294 MPa, and 14.5%, respectively.