Study on the Current Carrying Friction and Wear Performance of Conductive Rollers for Ni-Cr Electroplating at High Current Density

Conductive rollers in Ni-Cr electroplating require wear-resistant surfaces under current-carrying contact. Ag coatings are susceptible to deformation and wear, while the protective response of Ag-Cu coatings under lubricated current-carrying sliding remains insufficiently characterized. In this study, an Ag-Cu coating was prepared on a T2 Cu substrate by rotary spray deposition and evaluated through microstructural characterization, nanoindentation, and sliding tests. Current-carrying friction tests were conducted at 20 N under PAO 10 lubrication for 30 min. The coating exhibited a higher mean hardness (1.943 ± 0.997 GPa vs. 1.055 ± 0.070 GPa) than the substrate. At 20 A, the coating maintained a coefficient of friction of approximately 0.12 and exhibited a wear volume of 2.44 × 10−3 mm3 within the measured region, 19.7% lower than that of the substrate. Morphological and elemental observations were consistent with oxidation and material redistribution. No clear overall advantage was observed at 10 A, whereas severe damage occurred at 30 A despite lower friction. These results indicate a protective benefit at 20 A under the tested conditions and support further evaluation of Ag-Cu coatings for conductive roller protection.