Effect of rare metal element interfacial modulation in graphene/Cu composite with high strength, high ductility and good electrical conductivity

Abstract We investigated the atomic and electronic structures and interface interaction of graphene/copper interface with rare earth elements (REEs) modified using density functional theory. The effect of interface interaction enhancement induced by interfacial modification is revealed, which results in significant improvement of the mechanical properties of graphene/copper. Thereby, we applied a novel strategy to incorporate Y element at the interface of graphene nanoplatelets/copper (GNPs/Cu) to improve mechanical properties of composites. Tensile tests demonstrated that the yield strength of composites increases by 95.4% via very low fraction (0.2 wt. %) of Y modification with elongation comparable to Cu, which exhibits excellent matched relationship between strength and ductility. Simultaneously, the composite equips with improved electrical conductivity compared with that of the matrix. We illustrated the strengthening effects of REEs modification at the interface that give rise to the effective load transfer, in consistence with the theoretical predication. Furthermore, the GNPs/Cu composites with the interface Ce/Sc elements modified were also fabricated, both of which showed excellent strength-ductility combination. Therefore, the universality of the present method is verified for the preparation of metal matrix composites with excellent mechanical properties through interface modification with REEs.