TiN/VCN多层膜的力学性能及摩擦磨损性能研究

采用多靶磁控溅射技术, 制备了TiN、VCN单层膜及调制比为1:1的系列调制周期的TiN/VCN多层膜。利用X射线衍射仪、纳米压痕仪、高温摩擦磨损测试仪和扫描电子显微镜研究了各种薄膜的微结构、力学性能及室温和高温摩擦磨损性能。研究表明: TiN/VCN多层膜以δ-NaCl面心立方结构为主; TiN/VCN多层膜的最大硬度值为28.71 GPa, 约为按混合法则计算所得理论硬度值的1.23倍, 并据此分析了TiN/VCN多层膜的致硬机理; TiN/VCN多层膜在室温下摩擦系数与TiN单层膜摩擦系数相近, 但当环境温度为700℃时, 摩擦系数约0.4, 较TiN单层膜(0.52)低。TiN/VCN多层膜室温和高温下的磨损率相比TiN单层膜减小了约3×10^-14 m³/(N·m)。从晶体化学和热测量方法角度讨论了TiN/VCN多层膜的Magnéli相V₂O₅的润滑机制。

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.