Synthesis of Cr3C2 coatings for tribological applications

PVD coatings such as TiN and CrN have been successfully applied to metal forming industries for their advanced wear resistance, Metal pick-up and sticking problems in certain deep drawing and plastic injection molding processes, however, demand more sophisticated tribological thin films. In this study, we evaluated chromium carbide coatings synthesized by PVD processes for potential applications in forming and molding operations. We deposited Cr3C2 thin films of 3 mu m thickness using both cathodic are evaporation and unbalanced magnetron sputtering to ensure superior adhesion strength at the film-substrate interface. Using X-ray diffraction(XRD), scanning electron microscopy (SEM)/electron desorption spectroscopy(EDS), Vicker's microhardness, and wear tests, we studied the influences of deposition parameters on microstructure and mechanical properties. Our results indicated that Cr3C2 outperforms hard chrome plating and CrN coatings in measures of sliding wear resistance and ease of mold release. We attributed Cr3C2's performance to its process-improved microhardness and low surface energy. In sum, we found Cr3C2 coatings to be highly promising for tribological applications at low-to-medium temperatures. (C) 1999 Elsevier Science S.A. All rights reserved.