Nanoindentation of bio-inspired graphene/nickel nanocomposites: A molecular dynamics simulation

In this paper, nanoindentation on graphene/nickel nanocomposites with a three-dimensional "brick-and-mortar" structure is studied by molecular dynamics (MD) simulation method. The effects of various geometrical variations on mechanical properties are investigated, including the length of graphene layer, the interlayer distance of two adjacent graphene layers, and the lateral gap size of adjacent graphene in each layer. The simulation results show that the addition of graphene sheets can effectively block the dislocation propagation. The strength and hardness of the bio-inspired nanocomposites decrease with the increase of the length of graphene layers, while the increase in the length of the graphene layer can avoid dislocations nucleation at the end of the graphene sheet. As the lateral gap of graphene increases, the strength of the material decreases, and dislocations are easier to pass through the gap. In the absence of defects, as the lateral gap increases, the strength becomes larger, and the hardness is not obviously affected. This result is expected to be helpful for the preparation of graphene/metal nanocomposites with extremely enhanced mechanical properties.