Enhancing Current-Carrying Tribological Properties of Slip Rings by Laser-Cladded Copper-Based Composite Coatings

Abstract High-power electrical slip rings, such as those employed in marine electric propulsion, require low contact resistance, high wear resistance, and excellent arc erosion resistance. To address these issues, TiB2/Cu composite coatings were fabricated by laser cladding. The friction and wear mechanism of the cladding layer under current-carrying conditions was analyzed through current-carrying friction and wear tests. At a laser power of 1600 W, cracks and pores at the interface were minimized, yielding sound metallurgical bonding, and the clad layer achieved an electrical conductivity of 90.8% IACS (International Annealed Copper Standard) and a microhardness of 197 HV. The dominant mechanism changed from abrasive wear at 5 A to adhesive wear coupled with arc erosion at 20 A, and finally to arc erosion wear at 40 and 50 A. The results show that the coating's wear and anti-arc erosion resistance are markedly enhanced by the addition of a TiB2 reinforcing phase, delivering superior service performance under high-current conditions compared with a pure copper coating. The results supply theoretical and technical support aimed at improving the reliability of marine slip ring components exposed to high current.