Effect of copper/tungsten heterophase interface on radiation resistance: Insights from atomistic simulations

Nanostructured materials have demonstrated superior radiation-damage tolerance compared to their coarse-grained counterparts, contributing to the extended lifespan of nuclear materials. However, the mechanisms underlying this enhanced irradiation resistance remain unclear. In this study, we present atomistic simulations to investigate the impact of Cu/W heterophase interface on the evolution of irradiation-induced defects. The simulation results reveal that the Cu/W interfaces can act as defect sinks, effectively trapping self-interstitial atoms (SIAs). Furthermore, the interface demonstrates both the interstitial emission and interstitial transfer mechanisms, wherein the trapped W SIAs facilitate the emission of Cu atoms from the interface to the Cu side. These emitted Cu SIAs can promote defect recombination on the Cu side, leading to a reduced defect concentration in the Cu/W nanomultilayers. Consequently, these combined mechanisms contribute to a lower overall concentration of irradiation-induced defect, thereby enhancing the radiation resistance of Cu/W nano-multilayers.