Molecular Simulation-based Hardness Calculation of Graphene-reinforced Copper-tungsten Alloy Contacts

Copper-tungsten (CuW) alloy has been widely used in the contacts of circuit breaker. With the rapid development of power system to higher voltage levels, the existing contact material shows extremely deficient wear resistance, which is usually characterized by hardness property. In this paper, the models of CuW80 and CuW80Gr with different graphene contents are established. Then, the nanoindentation is used to calculate the material hardness, based on which the effect of graphene is discussed. Simulation results indicate that the addition of graphene can enhance the hardness of CuW alloy composites, and the hardness will decrease with graphene content. The indentation hardness of CuW80Gr with a graphene content of 0.037wt% reaches 13.16 GPa, which improves by 63% compared to CuW80 model. The research results in this paper can guide the design and modification of the contact material of circuit breaker.