Effects of applied mechanical strain on vacancy clustering in FCC Ni

Irradiation-induced vacancy evolution in face-centered cubic (FCC) Ni under mechanical strains was studied using molecular dynamics simulations. Applied hydrostatic strain s led to different stable forms of vacancy clusters, i.e., voids under epsilon >= +2% and stacking fault tetrahedras (SFTs) under epsilon <= 0. Direct transitions between SFT and void revealed that increasing epsilon magnitude facilitated the thermodynamic stability and dynamical evolution. The estimated free energy difference could well validate the dynamical simulations results by accounting for entropic contribution, which was revealed to play an important role in the thermodynamic stability of vacancy clusters in FCC Ni. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

In this study, irradiation-induced vacancy evolution in face-centered cubic (FCC) Ni under mechanical strains was investigated using molecular dynamics simulations. It was found that the applied strain led to different stable forms of vacancy clusters, with the entropy contribution playing an important role in the thermodynamic stability of these clusters. The results provide insights into the dynamic evolution and thermodynamic stability of vacancy clusters in FCC Ni.