Radiation tolerance of nickel-graphene nanocomposite with disordered graphene

Metal-graphene nanocomposites are expected to have excellent radiation tolerance, and may become a candidate structural material for advanced fission reactors. Nevertheless, whether the structural disorder of graphene introduced by preparation or irradiation can strongly affect the radiation tolerance of the composites is still unclear. Here we investigate the radiation tolerance of nickel-graphene nanocomposite by using 300 keV helium-ion irradiation at 823 K. Results showed that the intrinsic crystalline structure of graphene would be continuously disrupted by the elevated temperature and irradiation. However, lesser crystal defects, such as lattice swelling and stacking faults, and smaller helium bubbles are observed in the composite than those in its pure counterpart. The reason may be attributed to graphene's own capability in maintaining two-dimensional structure and inhibiting the formation of large-size defects. Thus, nickel-graphene interfaces can be maintained and their role in healing radiation-induced defects is still able to play. Results of the study highlight the potential of metal-graphene nanocomposites for use as radiation tolerance materials. (C) 2018 Elsevier B.V. All rights reserved.