Research on the Tribological Properties of Laser Cladding Mo‐Based Gradient Coatings on the Surface of Copper Alloy Conductive and Wear‐Resistant Components

Copper alloys are widely used as conductive wear‐resistant materials due to their excellent electrical conductivity, but their relatively low hardness, poor wear resistance, and limited thermal stability restrict applications under severe conditions. In this study, three types of molybdenum‐based gradient protective coatings were fabricated via laser cladding. First, dry sliding tests without electrical current showed that the coatings significantly reduced the friction coefficient and decreased weight loss by approximately three times compared to the bare copper alloy, along with producing smoother wear tracks. Subsequent current‐carrying friction tests were performed under varying current densities using a custom high‐current‐density (10 6 A/m 2 ) and high‐speed (1000 r/min) tribometer. The mechanisms were systematically investigated from perspectives including electrical conductivity, high‐temperature thermal stability, current intensity, aluminum adhesion behavior, and arc initiation rate. The Mo‐based coatings exhibited not only high electrical conductivity and thermal stability but also a strong ability to suppress aluminum adhesion on the copper matrix. Moreover, the lower arc initiation rate on the coating surfaces contributed to reduced interfacial temperature, thereby preventing the decomposition of the self‐lubricating Al 2 O 3 phase formed within the wear track.