The effect of stress on the cross-slip energy in face-centered cubic metals: A study using dislocation dynamics simulations and line tension models

Abstract

Dislocation dynamics simulations were used to calculate the energy barrier of cross-slip via Friedel–Escaig mechanism in face centered-cubic copper. The energy barrier in the unstressed case was found to be 1.9 eV, as reported by Ramírez et al. (2012). The energy barrier was reduced by applying an external stress. The most effective way of reducing it, was by applying a compressive stress on the glide plane. Furthermore, it was confirmed using dislocation dynamics simulations, that both the Schmid and Escaig stress have a comparable effect in reducing the energy barrier, in qualitative agreement with the atomistic simulations performed by Kang et al. (2014) in face-centered cubic nickel. Most of the energy barrier values for stressed cross-slip fell within the experimental error of 1.15 ± 0.37 eV measured by Bonneville et al. (1988). Moreover, the activation enthalpy obtained from the line tension model of Kang et al. (2014) and the general expression for the activation enthalpy proposed by Malka-Markovitz and Mordehai (2019) were in good quantitative agreement with the simulation results. Hence, both could be used to calculate the activation enthalpy of screw segments in dislocation dynamics simulations.