Faceting and Twin-Twin Interactions in {1121} and {1122} Twins in Titanium

Twin-twin interactions are an important component of the microstructural evolution of hexagonal close-packed metals undergoing plasticity. These interactions are prevalent because of the predominance of twinning due to limited easy slip modes. Despite their importance, the complexities of the atomic-scale behavior of interacting twins has limited robust characterization. Using interfacial defect theory, we developed a three-dimensional model of twin-twin interactions, double twinning and other complex interfacial reactions that occur between twins acting on different interface planes. Using molecular dynamics, {1122} and {1121} twins in titanium were activated and produced facets, twin-twin interactions and double twins that we characterized with our model. The results showed excellent agreement between the molecular dynamics results and the model. Surprisingly, some highly ordered and mobile boundaries can be produced by these complex reactions, which could provide important insights for higher scale models of plasticity.

Automated summary

Twin-twin interactions play a crucial role in the microstructural evolution of hexagonal close-packed metals during plasticity. However, the characterization of the atomic-scale behavior of interacting twins has been limited. In this study, a three-dimensional model based on interfacial defect theory was developed to characterize twin-twin interactions and other complex interfacial reactions. Molecular dynamics simulations were conducted on titanium, showing excellent agreement with the model. Surprisingly, highly ordered and mobile boundaries were produced by these complex reactions, which could provide important insights for higher scale models of plasticity.