Mechanical properties of graphene-metal composite system: a first principles study

High-strength graphene is an ideal reinforcer in preparing the composites. In this study, the binding ability of graphene to Al, Cu, Zn, Li, and Mg metal atoms and the mechanical properties of graphene metal composites are analyzed by the first-principle calculations. The results show that the adsorption of metal atoms causes lattice distortion of graphene to the certain level, and Al, Cu, and Li atoms have an adsorption potential well on graphene sheets, and the two atoms spontaneously form a bond. Moreover, the explicit electronic interaction between metal atoms and carbon atoms results in different adsorption energies of metal atoms. The mechanical properties of interface structure between (111) crystal plane and graphene were studied by using the equivalent cubic system elastic constants. Compared with other metals, the Cauchy pressure criterion of composite structure formed by FCC Al crystal and graphene is 37.4 ~ 64.7% higher and the modulus are up to 59.8% higher, which reflect stronger elasticity, good ductility, and strong anisotropy.