Achieving excellent tribological performance of a-C: WC film by controlling sub-nano-structure

To study the tribological behavior of a-C: WC films in the marine environment, the a-C: WC films fabricated by reactive magnetron sputter technique with different bias voltages were reciprocally sliding against Si3N4 balls in artificial seawater. Results showed that the a-C: WC film was an amorphous matrix mixed with plenty of short-range ordered structures in sub-nano scale. Excellent tribological performance of the a-C: WC film in seawater could be achieved when the sub-nano-structure possessed excellent overall mechanical properties in combination with fewer growth defects on the surface. The lowest COF and wear rate for a-C: WC film (−30 V) in seawater were 0.12 and 6.2 × 10−8 mm3N−1m−1, respectively. The results demonstrated the potential application of a-C: WC films as protective surfaces in marine environments.