Self-healing mechanism of irradiation defects near [formula omitted] grain boundary in copper

Abstract

Exploring the mechanism for elimination of vacancies and interstitial defects around grain boundaries is of special significance for nuclear materials. Formation energies and diffusion barriers of point defects at different sites near Σ=11(113) grain boundary in copper have been calculated by first principle in order to investigate the interactions between grain boundaries and defects. The results show that grain boundaries (GBs) facilitate the diffusion of both vacancy and interstitial defects to GBs, and the interstitials are more active than the vacancies in this kind of diffusions. Furthermore, with low energy barrier, interstitials could be emitted from the grain boundary and annihilate bulk vacancies, indicating that grain boundaries can play a role of the sink for both radiation-induced defects and significantly improve the radiation resistance of the material.