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 101¯1 and 12¯10 dipoles of {101¯2} extension twin in Mg are analyzed by utilizing atomistic simulation. Results show that comparing with a 101¯1 dipole, a 12¯10 dipole needs less energy to form and grow. The results explain the lateral growth of an extension twin reported previously.