Investigating the cross-slip rate in face-centered cubic metals using an atomistic-based cross-slip model in dislocation dynamics simulations

Abstract

The cross-slip rate of screw segments in dislocation dynamics simulations was calculated using the model of Esteban-Manzanares et al. (2020), which is based on a combination of the harmonic transition state theory and the Meyer–Neldel rule. In said model, the cross-slip rate is expressed as a function of the microstructure parameters. In particular, the rate prefactor depends on the nucleation length of cross-slip and the activation enthalpy, which are themselves functions of the local stress. Malka-Markovitz and Mordehai (2019) solved the line tension model of cross-slip exactly by linearizing the interaction force between the partials. They obtained analytical expressions for the nucleation length and the activation enthalpy as functions of a general stress state. These expressions were used to evaluate the cross-slip rate at each simulation step. The results are in quantitative agreement with atomistic simulations.