Deformation mechanism of high ductility Mg-Gd-Mn alloy during tensile process

In this research, a high ductility Mg-Gd-Mn magnesium alloy was designed and developed, with an elongation capability surpassing 50%. To gain insights into the underlying mechanism behind the high ductility of the Mg-2Gd-0.5Mn alloy, quasi-in-situ electron backscattered diffraction and two-beam diffraction were conducted. The results reveal that the Mg-Gd-Mn alloy exhibits a distinct rare-earth texture, and the activation of non-basal slip systems is evident from the clear observation of non-basal slip traces during the later stages of deformation. However, the primary deformation mechanisms in Mg-Gd-Mn alloy remain basal slip and {10–12} tensile twinning, and the remarkable ductility observed in Mg-Gd-Mn alloys can be attributed to the softening of non-basal slip modes, which leads to a coordinated deformation between various modes of deformation. To further validate this conclusion, an analysis was conducted using a visco-plastic self-consistent (VPSC) model to investigate the relative activity of basal and non-basal slip in Mg-Gd-Mn alloys. The obtained results align well with experimental observations, providing additional support for the hypothesis.