类金刚石膜的高温摩擦特性及热力学分析

Friction behavior of DLC films under high temperature and analysis of thermodynamics

采用等离子体增强化学气相沉积技术在H13钢基体上制备了含氢类金刚石(DLC)膜,摩擦配副为镀制了DLC膜的440C钢球。采用高温摩擦磨损试验机考察了DLC膜在大气环境下的高温摩擦特性。实验结果表明:DLC膜的摩擦特性随温度的升高而恶化。在摩擦初始阶段,温度低时DLC膜的摩擦系数随温度的升高而减少;而温度升高到400℃时,DLC膜的摩擦系数高达0.8。采用激光拉曼光谱仪及光学显微镜分析和观察了不同温度下摩擦副磨损表面的微观结构和表面形貌,并从热力学的角度研究了DLC膜及钢基体在大气环境下的摩擦特性。采用吉布斯自由能判据分析了高温下摩擦副摩擦化学反应发生的规律,实验结果与理论分析吻合较好,研究结果对DLC膜高温摩擦学性能的研究和设计提供参考。

Diamond-like-carbon( DLC) films was deposited on H13 steel substrate by plasma enhanced chemical vapor deposition technology. The friction behavior of self-mated DLC films was investigated by a high temperature friction and wear tester under high temperature friction conditions in the atmosphere. The results show that the friction behavior of DLC films is deteriorated with increase of temperature. At the initial stage,coefficient of friction( COF) decreases with increase of temperature below 400 ℃. However,COF is as high as 0. 8 at 400 ℃. Further more the friction behavior of DLC films and substrate in air was also investigated based on thermodynamics. The tribochemical reactions are analyzed by using Gibbs free energy criterion,it is found that the theoretical results are in agreement with the experiment data. The results can provide the reference for design and research of the tribological properties of DLC films at elevated temperature.