Structural evolution on {10−12} co-zone twin-twin junction in magnesium single crystal

The local stress state induced by twin-twin interaction leads to the complex microstructural evolution. In this paper, we studied the local structural characteristics on the {10–12} co-zone twin-twin junction in the compressed Mg single crystal. For parent crystal, the primary lattice rotation through the low-angle tilt around the [1−210] axis facilitates the formation of the reorientated parent-crystal substructure on the acute-angle side of incoming twin. Experimental results reveal that local stress field is formed on the acute-angle side of incoming twin, and the level of stress concentration increase with further twin-twin interaction. On the twin-twin junction, the local stress caused by twin-twin interaction induces the local lattice rotation of incoming twin, leading to the orientation of the incoming-twin tip close to that of encountering twin, which indicates a tendency of the twin-twin merger interaction. And the structural evolutions of the interacted twins are consistent with twinning dislocation reaction. The size difference between the interacted twins may be an important reason for twin-twin merger interaction.