First-Principles Calculation and Kink-Dislocation Dynamics Simulation on Dislocation Plasticity in TiZr-Based Concentrated Solid-Solution Alloys

The dislocation plasticity of TiZr-based hexagonal close-packed (HCP) concentrated solid-solution alloys (CSAs) is investigated using a multiscale simulation approach combining the first-principles calculation and Frenkel–Kontonova kink-dislocation model. The first-principles calculation reveals that dislocation-mediated slip is significantly enhanced by the additions of Y and Sc in TiZrHf CSAs. The dislocation kinetics is simulated using the kink-dislocation model at mesoscopic scales, and the predicted mechanical strength of CSA is found to be consistent with experimental results. In addition to predicting the mechanical properties of CSAs accurately, the multiscale simulation approach elucidates the deformation mechanisms in CSAs at atomic scales, suggesting that the approach is robust in modeling the dislocation plasticity of CSAs.