Deformation behavior characterized by reticular shear bands and long chain twins in Mg-Gd-Nd(-Zn)-Zr alloys
Qian Zhang, Ziyi Chen, Quanan Li, Xiaoya Chen, Jiaxin Zhao, Jian Bao
Abstract
We analyzed the deformation behavior of Mg-Gd-Nd(-Zn)-Zr alloys under high temperature uniaxial compression, and reported two special nucleation mechanisms of dynamic recrystallization (DRX): Nucleation and expansion of DRX based on reticular shear bands (Shear band dynamic recrystallization, SBDRX) and long chain twins (Twin dynamic recrystallization, TDRX). The reticular shear bands in Mg-Gd-Nd-Zr alloy are mainly caused by the crossing of strain gradients from different directions, which is related to the high activity of pyramidal <c+a> slip at high temperature. The addition of Zn makes the DRX mechanism mutate, and TDRX is dominant in Mg-Gd-Nd-Zn-Zr alloy. The nucleation of a large number of {10–12} twins is abnormal, which may be related to the decrease of I 2 stacking fault energy caused by Gd/Nd–Zn compound addition. Based on the mechanical properties and microstructure, it can be concluded that the addition of Zn can promote the DRX, reduce the deformation resistance and improve the workability.