Modeling microstructure evolution of f.c.c. metals under irradiation in the presence of He

We use kinetic Monte Carlo simulations with input parameters obtained from molecular dynamics calculations to study microstructure evolution in irradiated f.c.c. metals in the presence of He. This model is able to reproduce the characteristic swelling curve of a f.c.c. metal and the dependence of this curve with dose rate. We provide an atomistic description of the evolution of defects produced by irradiation and particularly of void nucleation. Stable, nanometer size He–vacancy complexes, created at the early stages of damage accumulation can grow under irradiation forming voids. These voids are responsible for macroscopic changes in the material, such as volume changes (void swelling). These simulations show how the initial clustering of vacancies in the cascade core influences the evolution of the microstructure and the nucleation of bubbles and voids.