Strengthening effect of graphene-edge dislocation interaction in graphene reinforced copper matrix composites

Abstract

The strengthening effect of graphene blocking dislocation propagation in graphene reinforced copper matrix composites (Gr-CMCs) was investigated via molecular dynamics (MD) simulations. Atomic models of Gr-CMCs including an edge dislocation (b = 1/6 (112)) were built to explore dislocations motion and structure evolution under shear deformation. The effects of the rotation angle and the arrangement of graphene were taken into account. The interaction between the graphene and an edge dislocation, as well as the graphene effect on the dislocation motion, was investigated. The results indicate that the graphene has a significant effect on the motion and velocity of the dislocation. The dislocation velocity decreases significantly when it reaches the graphene, proving a good blocking effect from the latter. In addition to the blocking mechanism, the new dislocation planes that form near the graphene when the rotation angle is greater than 45° also contribute to the strengthening of the Gr-CMCs. Furthermore, the influence of the distance between two abreast graphene sheets on the dislocation motion is discussed. It is found that the strengthening effect can be improved by adjusting the angle and arrangement of the graphene in order to decrease the dislocation velocity and increase the dislocation density. The results of these simulations may provide guidance for the design of future composite materials.