The effect of basal dislocation on { 11(2)1 } twin boundary evolution in a Mg-Gd-Y-Zr alloy

This study aims to understand the features of { 11(2)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)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)1 } twin boundaries,accompanying with the formation of a step at the twin boundary.Such a { 11(2)1 } twin boundary evolution mechanism provides a new vision of twinning behavior in Mg alloys.