Current-Carrying Friction Behavior and Interfacial Evolution Mechanism of Copper Alloys for Industrial Chromium-Plating Cathodes

In sliding electrical contact processes, the effects of applied electric current on frictional behavior and surface damage are not aligned, and elucidating the relationship between the two is critical for optimizing the performance of conductive friction pairs in continuous chromium plating systems. In this study, reciprocating friction tests on a self-lubricating copper alloy were performed under varying normal loads (5–20 N) and applied currents (0–5 A), and the frictional response and interfacial evolution of the material were characterized via 3D profilometry, SEM, EDS, and XRD. The results demonstrate that under a 10 N load, the applied current generally reduces the friction coefficient, while the wear-track volume exhibits a non-monotonic trend with current variation. Microstructural analysis reveals that current-carrying friction is accompanied by plastic flow of the Cu matrix, redistribution of carbon-enriched regions, and enhanced surface oxygen signals, reflecting dynamic interfacial evolution under the combined action of mechanical shear and electric current. This work uncovers the asynchronous relationship between current-carrying friction reduction and surface damage evolution, providing experimental evidence for operating condition optimization of sliding conductive materials in continuous chromium plating systems.