Three-Dimensional Atomistic Simulations of \( \left\{ {10\bar{1}2} \right\}\) Non-cozone Twin–Twin Interaction in Mg—Role of Twin Stability and Mobility

Given the ease of activation of tensile twinning on the \( \left\{ {10\bar{1}2} \right\}\) planes in Mg, multiple \( \left\{ {10\bar{1}2} \right\}\) twin variants can be activated and interact with each other. The outcomes of these interactions are twin–twin junctions (TTJs) that can serve as initiation sites for microcracks. Here, we investigate the 3D structural characteristic and evolution of the non-cozone \( \left\{ {10\bar{1}2} \right\}\) twin–twin junctions using atomistic simulations. This comprehensive approach allows us to identify additional twin–twin boundaries (TTBs) such as the TTB_BP and TTB_K2. They formed due to the interaction between the basal prismatic (BP) and conjugate twin (K₂) interfaces with the coherent twin boundary (CTB). Moreover, the TTJs associated with the \( \left\{ {\bar{1}2\bar{1}2} \right\} \) TTBs are found to promote the growth of the 3-D twin along the normal and forward direction of the twin during the interaction and hinder the detwinning process when loading is reversed.