| Abstract Scope |
When high-Peierls-barrier materials, such as iron (Fe), silicon (Si), or high entropy alloys (HEAs), are deformed, dislocation kinks can be activated. The kink dynamics then dictates the dislocation activities and in turn, the material’s overall performance. Such kink-controlled dislocation dynamics is, however, not fully understood because it remains a challenge using single-scale techniques to simultaneously resolve the motion of a µm-long dislocation line and the atomic-level kink diffusion along the line. To meet this challenge, we perform concurrent atomistic-continuum simulations of dislocations in Fe, Si, and HEAs. For the first time, the dynamics of µm-long dislocation lines is quantified without smearing out the underlying kink dynamics at the atomic level. Kink diffusion, migration barrier, and dissipation parameter, are all found to be sensitive to the dislocation length. Length-dependent dislocation mobility laws are then formulated for higher-scale computer models to explain the experimental observations at the macroscale. |