Insights into the Tribological Properties and Electrical Conductivity of Cu–C Coating Under Grease Lubrication

In this paper, a Cu–C coating was prepared on a copper substrate through a magnetron sputtering coating process, and the effect of a composite grease containing WS₂ and MoS₂ on its tribological behavior and electrical conductivity was studied. Experimental results revealed that the Cu–C coating exhibited certain friction-reducing effects under dry sliding conditions with a 5 N load. In the lubricated state with polyurea-based grease, the Cu–C coating demonstrated lower friction coefficients and contact resistances at 2 N and 5 N loads, accompanied by reduced wear rates, indicating a synergistic effect between the lubricant and the coating, enhancing the friction-reducing performance. Furthermore, the incorporation of additives such as WS₂ and MoS₂ can effectively decrease both friction and contact resistance. Notably, 1% WS₂ grease, in combination with Cu–C coating, exhibits superior compatibility, resulting in optimized tribological properties and electrical conductivity. Therefore, the results of this study suggest that the combination of Cu–C coatings with WS₂ grease can effectively improve the electrical conductivity and friction-reducing and anti-wear capabilities of Cu–Cu sliding pairs, providing an effective solution for enhancing the electrical conductivity of electric vehicle connectors and improving the overall efficiency of the battery system.