Tensile mechanical characteristics and deformation mechanism of metal-graphene nanolayered composites

Metal-graphene nanolayered composites (MGNLCs), composed of alternating layers of metal (copper here) and graphene layers, are new emerging engineering materials with outstandingly enhanced mechanical properties thanks to the high intrinsic in-plane strength and modulus of one-atom-thick layers of graphene. In this paper, mechanical behavior and elastic-plastic deformation mechanisms of MGNLCs subjected to uniaxial tensile loading were investigated based on molecular dynamics (MD) simulations. Stress-strain curves of the composite samples and their elastic properties were obtained and compared with their pure metal counterparts. In addition, influence of thickness of the metal layers on the composite performance was determined which seems tough or even impossible to be dealt with by the experimental techniques. Graphene inclusion outstandingly increased strength and failure strain of the composites and remarkably improved their stiffness and toughness. Graphene layers could provide effective barriers against shearing flows and dislocation propagation of the metal layers and made the applied strain energy spread out more evenly inside the material.