The effect of basal <a> dislocation on 112¯1 twin boundary evolution in a Mg-Gd-Y-Zr alloy

This study aims to understand the features of 11 2 &#175; 1 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 dislocations are easily activated within the 11 2 &#175; 1 twin and suppressed in the surrounding matrix. The consequent basal dislocation-twin interaction during deformation can lead to the misorentiation deviation of 11 2 &#175; 1 twin boundaries, accompanying with the formation of a step at the twin boundary. Such a 11 2 &#175; 1 twin boundary evolution mechanism provides a new vision of twinning behavior in Mg alloys.