J. Mater. Sci. Technol. ›› 2021, Vol. 81: 212-218.DOI: 10.1016/j.jmst.2020.11.062

• Research Article • Previous Articles     Next Articles

The effect of basal <a> dislocation on $\left\{ 11\bar{2}1 \right\}$ twin boundary evolution in a Mg-Gd-Y-Zr alloy

Huan Zhanga, Yangxin Lia,*(), Yuxuan Liua, Qingchun Zhua, Xixi Qia, Gaoming Zhua, Jinhui Wangb, Peipeng Jinb, Xiaoqin Zenga,b,**()   

  1. aNational Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, Shanghai, 200240, PR China
    bQinghai Provincial Engineering Research Center for High Performance Light Metal Alloys and Forming, Qinghai University, Xining, 810016, PR China
  • Received:2020-09-05 Revised:2020-11-05 Accepted:2020-11-25 Published:2021-01-07 Online:2021-01-07
  • Contact: Yangxin Li,Xiaoqin Zeng
  • About author:**National Engineering Research Center of Light AlloyNet Forming and State Key Laboratory of Metal Matrix Composite, Shanghai JiaoTong University, 200240, Shanghai, PR China.E-mail addresses: xqzeng@sjtu.edu.cn (X. Zeng).
    *E-mail addresses: xqzeng@sjtu.edu.cn (X. Zeng).

Abstract:

This study aims to understand the features of $\left\{ 11\bar{2}1 \right\}$ twin boundaries in a high strain rate compressed Mg-10Gd-3Y-0.4Zr using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Based on the Schmid factor calculations, the basal <a> dislocations are easily activated within the $\left\{ 11\bar{2}1 \right\}$ twin and suppressed in the surrounding matrix. The consequent basal <a> dislocation-twin interaction during deformation can lead to the misorentiation deviation of $\left\{ 11\bar{2}1 \right\}$ twin boundaries, accompanying with the formation of a step at the twin boundary. Such a $\left\{ 11\bar{2}1 \right\}$ twin boundary evolution mechanism provides a new vision of twinning behavior in Mg alloys.

Key words: Mg alloys, Plastic deformation, Twinning, Dislocation, Misorientation