Interaction mechanisms of screw dislocations with and twin boundaries in Mg

Abstract

Molecular dynamics simulations were carried out to investigate the interactions between screw partials and the and twin boundaries in Mg. In the twin, the interaction was attractive and the partials were absorbed readily in the boundary. In the twin, however, they passed through the twin boundary because of a repulsive interaction when a large applied strain was applied. The total energy including the dislocation core energy and the twin boundary energy was found to be similar before and after the absorption of the partials in the twin boundary, while it increased upon the absorption of the partial in the twin boundary. The origins of the total energy variations are discussed from a crystallographic viewpoint.

Keywords:

• magnesium alloys
• dislocations
• twinning
• molecular dynamics