Tribological behaviour of Mo-W doped carbon-based coating at ambient condition

Poor adhesion strength and low thermal stability often restrict the tribological applications of the state-of-the-art diamond-like-carbon coatings in automotive industry. A novel carbon-based coating doped with molybdenum and tungsten (Mo-W-C) is deposited using the advantages of HIPIMS to overcome these limitations and to provide enhanced tribological performance. Low friction (µ=0.335 against steel counterpart) and high wear resistance (Kc=3.87×10−16 m3 N−1 m−1) are observed after 7.5 km sliding distance and the coating remains intact within the wear track after sliding. It is concluded that the tribological performance of Mo-W-C coating at ambient condition excels due to its dense microstructure, interfacial adhesion strength and in-situ formation of solid lubricants such as graphitic carbon particles, MoO3 and Magnéli phase oxides of molybdenum and tungsten in the transfer layer during sliding.