Synthesis and characterization of Cu3N–WC nanocomposite films prepared by direct current magnetron sputtering

Cu3N–WC films were synthesized on an arc ion plated TiNx interlayer by direct current magnetron sputtering. The Cu3N–WC films, composed of columnar WC crystals 3–5 nm in size and amorphous Cu3N phases, were grown using the layer-plus-island mode. Deposition rate of Cu3N–WC films declined from 11.7 to 7.5 nm/min when the WC target power increased from 200 to 400 W because the Cu target was poisoned by the diffusion of WC molecules. Nano-indentation testing results showed that the highest measure of hardness of Cu3N–WC films was up to ∼ 41 GPa and the H3/E⁎2 value of the Cu3N–WC47.4 was around 0.41 GPa, indicating the excellent plastic deformation resistance of the film. Incorporation of the soft lubricant Cu3N phase and the uniform distribution of WC hard phases resulted in significant improvements in friction coefficient and wear resistance. As such, Cu3N–WC films have a good potential in future wear applications.