Atomistic energy analysis on disconnection dipoles of extension twin in Mg

Abstract The migration of a twin boundary is contributed by the nucleation and expansion of twinning disconnection loops. The expansion of a loop is accomplished by the growth of disconnection dipoles in different directions. In this paper, the energetic and structural characteristics of " open=" 10 1 ¯ 1 and " open=" 1 2 ¯ 10 dipoles of { 10 1 ¯ 2 } extension twin in Mg are analyzed by utilizing atomistic simulation. Results show that comparing with a " open=" 10 1 ¯ 1 dipole, a " open=" 1 2 ¯ 10 dipole needs less energy to form and grow. The results explain the lateral growth of an extension twin reported previously.