Mechanical Properties and Tribological Performance of TiN/VCN Multilayers

Monolithic TiN, VCN films and TiN/VCN nano-multilayer films with different modulation periods were prepared by magnetron sputtering. Microstructures, mechanical properties and friction properties at room and high temperature of these films were investigated by X-ray diffraction (XRD), nano-indentation, and CSM high temperature ball-on-disc tribometer. The results show that the TiN/VCN multilayer films are mainly nanocrystalline with δ-NaCl fcc structure. Maximum hardness of TiN/VCN multilayer films is 28.71 GPa, about 23% higher than the value calculated by the rule of mixtures. Based on these data, a mechanism of the superhardness in this system is proposed. Friction coefficients of TiN/VCN multilayers are similar to that of TiN films at room temperature, but lower than that of TiN films when testing temperature is increased to 700 Wear rates of TiN/VCN multilayers at room and high temperature decrease about 3×10-14 m3/(N·m) comparing to that of single layer film. The lubrication mechanism of Magnéli phase (V2O5) is discussed in terms of crystal chemistry and thermal measurement methods. In conclusion, compared to TiN films, the friction and wear properties of TiN/VCN multilayer films are greatly improved.