Molecular dynamics studies on mechanical properties and deformation mechanism of graphene/aluminum composites

In this study, the mechanical properties of a graphene/aluminum (Gr/Al) composite under uniaxial tension and compression were investigated using molecular dynamics (MD) simulations. Six different simulation models were used to investigate whether the addition of graphene significantly improved the stiffness and strength of Gr/Al composites. Moreover, the results show that the existence of a graphene layer can effectively prevent the propagation of dislocations at the interface, thus improving the mechanical properties of the composites. The deformation mechanism of the composites was studied by comparing the effects of the deformation behavior, compressive stress, and dislocation. The dislocation movement of the Al matrix during compression was further investigated. It was determined that stair-rod and Hirth dislocations occurred in the Al matrix, and the graphene layers exhibited bulging and kink deformation. Furthermore, the mean curvature and Gaussian curvature of the compressed graphene surface were measured, and the deformation characteristics of graphene in the composites were considered using the geometric method. We applied a new method to calculate the surface curvature and mechanical material deformation.