This study aims to understand the features of $\left\{11\overline{2}1\right\}$ twin boundaries in a high strain rate compressed Mg-10Gd-3Y-0.4 Zr 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 $\left\{11\overline{2}1\right\}$ twin and suppressed in the surrounding matrix. The consequent basal <a> dislocation-twin interaction during deformation can lead to the misorentiation deviation of $\left\{11\overline{2}1\right\}$ twin boundaries, accompanying with the formation of a step at the twin boundary. Such a $\left\{11\overline{2}1\right\}$ twin boundary evolution mechanism provides a new vision of twinning behavior in Mg alloys.

这项研究旨在了解 $\left\{11\overline{2}\mathrm{1个}\right\}$使用电子背散射衍射（EBSD）和透射电子显微镜（TEM）在高应变率压缩Mg-10Gd-3Y-0.4 Zr中形成双晶界。基于施密特因子的计算，基<a>位错很容易在$\left\{11\overline{2}\mathrm{1个}\right\}$并在周围的矩阵中被抑制。随之而来的基底<一>错双变形期间相互作用可导致的misorentiation偏差$\left\{11\overline{2}\mathrm{1个}\right\}$孪生边界，伴随在孪生边界处形成台阶。这样的$\left\{11\overline{2}\mathrm{1个}\right\}$ 孪晶边界演化机制为镁合金的孪生行为提供了新的视角。