Current-carrying tribological behavior and wear mechanism of silver-based composite coatings: Incorporating nanosized Ag particles into lubricant

The application of conductive lubricants into the friction interface has emerged as a common and efficient approach to improve the current-carrying tribological behavior and wear characteristics on the metallic surface. This work incorporates 0.1[Formula: see text]wt.% nano-sized Ag particles as conductive fillers in lubricant and investigates the current-carrying tribological behavior of silver-based composite coatings through reciprocating sliding friction experiments. The wear mechanisms of the composite coatings are analyzed under different conditions, including varying lubricants, high loads, and high currents. The experimental results indicate that under lubrication, wear characteristics are dominated by mechanical friction and wear, with arc erosion occurring when the current reaches 20[Formula: see text]A. Furthermore, a wear severity progressively increases with higher currents when the load reaches 20[Formula: see text]N. The introduced Ag particles effectively diminish contact resistance at the current-carrying friction interface, and mitigating the wear severity of composite coatings, the wear volume decreased by about 18.9% under the same conditions. The wear behavior exhibits distinct patterns depending on the applied load and current conditions. Analysis of the mechanical properties of subsurface and the chemical composition of wear tracks surface. The mechanical properties reveal that the maximum surface nanohardness reaches 2.1[Formula: see text]GPa, while the maximum increase of subsurface nanohardness caused by current and load is 12.8% and 10.5%, respectively, and the degree of current-induced work hardening is more pronounced. Additionally, excessive loads and currents lead to interfacial heat generation, causing contact instability, friction pair separation, discharge events, and accelerated electrical damage and material transfer. The findings of this study provide important theoretical support and technical guidance for the surface protection of solid materials against current-carrying friction and wear in critical electrical equipment components.