Feasible preparation and improved properties of Ag-graphite composite coating for switch contact by cyanide-free electrodeposition

A cyanide-free electrodeposition system was employed to prepare Ag-graphite composite coatings on Cu substrate for switch contact. The effects of graphite concentration, current density, stirring speed, and plating temperature on the thickness and quality of the composite coating were investigated. The feasibility of cyanide-free electrodeposition for Ag-graphite composite was confirmed and the optimized conditions were determined. The growth mechanism of the composite coating was also analyzed. The properties of the composite coating were also investigated compared with Cu substrate and Ag coating. The results show that the Ag-graphite composite coating has the lowest friction coefficient, moderate corrosion resistance, and relatively low contact resistance. The present results indicate that Ag-graphite composite coating prepared by cyanide-free electrodeposition is suitable for disconnector coating.