An attempt to improve cavitation erosion resistance of UHMWPE coatings through enhancing thermal conductivity via the incorporation of copper frames

Abstract

Ultrahigh molecular weight polyethylene (UHMWPE) coating and UHMWPE‑copper (UHMWPE-Cu) coatings with different copper content were fabricated using a sintering method. The thermal conductivity of the coatings increased with the increasing copper content, but the resistance to cavitation erosion did not. The most optimised resistance was achieved by the coating with 8.3 wt% copper, whose thermal conductivity was 22.7% greater and total volume loss after 10 h cavitation erosion was 14% lower than those of pure UHMWPE coating. Underdosed and overdosed copper can significantly compromise the cavitation erosion resistance, as there is a trade-off between the benefit of enhancing thermal conductivity and the cost of weakening interface bonding. In addition, all the coatings exhibited the same damaged features. The in-situ observation was performed by a 3D profilometer to reveal the failure mechanism, finding that the process of the tilt-initiated pealing-off was the main source of the failure, which composed of preferential attack at the interface, tilting of the splats, and the detachment of the splat.