A molecular dynamics simulation study on the role of graphene in enhancing the arc erosion resistance of Cu metal matrix

Abstract

Molecular dynamics simulation has been applied to study the mechanisms through which graphene protects Cu from arc erosion in Cu-W arcing contacts. The impact of arc erosion has been simplified as positive ion bombardments on a cathode surface. Sulphur ions were used as incident ions while the number of ions, incident energy, and incident area varied during the simulations. Cu covered by a graphene layer had fewer vacancies and sputtered atoms than in the pure Cu system. Results show that the graphene layer can dissipate the energy transferred from incident ions by a shock wave, and also prevent recoiled Cu atoms from penetrating the graphene layer resulting in better arc erosion performances than in the pure Cu system. For both models, the sputtering yield gradually decreases and maintains a very low value as the number of incident ions increases. Similar to the experimental results, the residual erosion crater on the Cu surface covered by graphene was shallower than that without a graphene layer.