Investigation of the structure and properties of electrodeposited Cu/graphene composite coatings for the electrical contact materials of an ultrahigh voltage circuit breaker

Abstract With the rapid development of ultrahigh voltage engineering (>500 kV), it has been increasingly difficult to satisfy the high requirements of traditional electrical contact materials for ultrahigh voltage circuit breakers. The copper/graphene (Cu/G) composite coatings on a pure copper substrate are successfully fabricated using a facile method of cathodic co-electrodeposition. The morphology, structure, coating composition and porosity of the Cu/G composite coatings were studied. The Vickers hardness of the Cu/G composite coating shows an increase of approximately 25% compared to a pure copper coating. The addition of graphene in the composite coating with a low friction factor of approximately 0.2 improves the wear resistance. The thermal conductivity of the Cu/G composite coating prepared in a plating solution of 10 g L −1 graphene content reaches 285.2 W m −1  k −1 at room temperature, which is an increase of 61.9% compared to a pure copper coating. The average chopping current (3.6 A) of the Cu/G composite coating is superior to that of the Cu20W80 alloy, indicating an improved arc ablation resistance. The Cu/G composite coating provides new possibilities to replace the traditional electrical contact materials of ultrahigh voltage circuit breakers.