Atomistic study of the strengthening mechanisms of graphene coated aluminum

We have investigated the nano-indentation responses of graphene/aluminum systems via computational nano-indentation processes by using molecular dynamics simulations. The effects of system temperature, grain-orientation and bilayer graphene are also investigated. We demonstrate that, the graphene coating enlarges the load-carrying area by about 5.36 times and changes the deformation behaviors of aluminum substrate during nano-indentation processes. The load bearing capacity of graphene/Al system is significantly improved by about 4.7 times compared with that of bare Al system. It is revealed that higher system temperature weakens the ultimate indentation depth and corresponding load. The grain orientation of aluminum substrate hardly affect the indentation mechanical properties of graphene/Al system. The strengthening effect of bilayer graphene is about 1.5 times that of monolayer graphene.