WC/C:H films synthesized by an hybrid reactive magnetron sputtering/Plasma Enhanced Chemical Vapor Deposition process: An alternative to Cr (VI) based hard chromium plating

The film nanohardness and tribological properties (i.e. friction coefficient and wear rate) are directly connected to the film chemical composition and structure. High nanohardness (~ 20 GPa), friction coefficient of μ = 0.5 and high wear rate (5.4 · 10− 13 m2/N) are obtained for the lowest carbon content of 37 at.%. When increasing the carbon content in the film (77 at.%), the hardness strongly decreases to ~ 10 GPa and a lower friction coefficient (μ = 0.2) and wear rate (4.7 · 10− 15 m2/N) are obtained. These properties are similar and even better than the ones of Cr(VI) based electroplating coatings, demonstrating the attractiveness of our WC/C:H films as a potential alternative to these coatings.