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.