Enhanced self-healing of irradiation defects near a Ni–graphene interface by damaged graphene: Insights from atomistic modeling

Graphene-reinforced nickel matrix nanocomposites with high-density interfaces are recommended as candidate materials for advanced nuclear reactors because of the potential irradiation tolerance. Nonetheless, the mechanism that graphene damage due to irradiation affects the tolerance of the composites remains unclear. Here we report the relationships between irradiation damage behavior of graphene and defect sink efficiency of nickel–graphene interface by using atomistic simulations. With the accumulation of irradiation dose, a nickel–graphene interface exhibits enhanced trapping ability to defects despite the gradually deteriorative damage of graphene. The enhancement originates in that the damaged regions of graphene can provide abundant recombination and/or annihilation sites for irradiation defects and strengthen the energetic and kinetic driving forces of the interface to defects. This study reveals a new possible interface-mediated damage healing mechanism of irradiated materials.