Graphene-enhanced tribological behavior of CuCr alloys: a molecular dynamics study on wear resistance and friction mechanisms

During high-strain and high-friction working conditions, electrical contact materials often face severe challenges from strong mechanical wear, which can lead to surface material failure and thus endanger the stability of the friction pair system. Therefore, there is an urgent need to develop high-performance anti-wear materials. As a two-dimensional self-lubricating material, graphene possesses excellent mechanical and electrical properties, showing broad application prospects in the field of metal tribological modification. This paper utilizes the CuCr30 alloy, a common material in the field of electrical contacts, as the matrix to create composite models reinforced with varying mass fractions of graphene. Molecular dynamics simulations are used to clarify the evolution characteristics of its tribological properties, and friction experiments are conducted to validate the simulation results. This study shows that graphene reinforcement significantly improves the tribological performance of CuCr alloys. As the graphene content increases, both the coefficient of friction and wear rate decline synchronously. Notably, CuCr30Gr1 alloy exhibits reductions of 51.40% in coefficient of friction, 56.90% in atomic wear area, and 74.93% in wear rate compared to the unmodified CuCr matrix. Mechanistic analysis reveals that the high-rigidity framework of graphene hinders dislocation propagation within the matrix. The strong C-C bonds restrain tangential slip of matrix atoms, transforming normal displacement into wrinkling deformation of carbon rings. This significantly elevates the energy barrier for dislocation slip, thereby enhancing the alloy's resistance to plastic deformation. This work elucidates the microscopic wear resistance mechanisms of CuCr30Gr composites, providing both theoretical insights and technical guidance for the development of high-performance wear-resistant CuCr alloys in electrical contact applications.