Most studies of liquid lubricants were carried out at temperatures below 200 °C. However, the service temperature of lubricants for aerospace and aeroengine has reached above 300 °C. In order to investigate the friction mechanism and provide data for high temperature lubrication, the friction and wear properties of chlorophenyl silicone oil (CPSO)-lubricated M50 steel and Si₃N₄ friction pairs were investigated herein. Ball-on-disk experimental results show that the lubrication performance of CPSO varies significantly with temperature. Below 150 °C, coefficient of friction (COF) remains at 0.13–0.15 after the short running-in stage (600 s), while the COF in the running-in stage is 0.2–0.3. At 200 °C and above, the running-in time is much longer (1,200 s), and the initial instantaneous maximum COF can reach 0.5. Under this condition, the COF gradually decreases and finally stabilizes at around 0.16–0.17 afterwards. This phenomenon is mainly due to the different thickness of boundary adsorption film. More importantly, the wear rate of M50 steel increases significantly with the temperature, while the wear rate barely changes at temperatures above 200 °C. The anti-wear mechanism is explained as tribochemical reactions are more likely to occur between CPSO and steel surface with the increased temperature, generating the FeCl₂ protective film on the metal surface. Accordingly, FeCl₂ tribochemical film improves the lubrication and anti-wear capacity of the system. At high temperatures (200–350 °C), FeCl₂ film becomes thicker, and the contact region pressure becomes lower due to the larger wear scar size, so the wear rate growth of M50 steel is much smaller compared with that of low temperatures (22–150 °C). The main findings in this study demonstrate that CPSO lubricant has good anti-wear and lubrication capacity, which is capable of working under temperatures up to 350 °C.

大多数液体润滑剂的研究都是在低于 200 °C 的温度下进行的。但航空航天、航空发动机用润滑油的使用温度已达到300℃以上。为了研究摩擦机理，为高温润滑提供数据，对氯苯基硅油(CPSO)润滑的M50钢与Si ₃ N ₄摩擦副的摩擦磨损性能进行了研究。球盘实验结果表明，CPSO的润滑性能随温度变化显着。在150℃以下，经过短暂的磨合阶段（600秒）后，摩擦系数（COF）保持在0.13-0.15，而磨合阶段的COF为0.2-0.3。在200℃及以上，磨合时间更长（1,200s），初始瞬时最大COF可达0.5。在此条件下，COF逐渐减小，最终稳定在0.16-0.17左右。这种现象主要是由于边界吸附膜厚度不同造成的。更重要的是，M50钢的磨损率随着温度的升高而显着增加，而在200℃以上的温度下磨损率几乎没有变化。其抗磨机理是随着温度的升高，CPSO与钢表面更容易发生摩擦化学反应，在金属表面生成FeCl ₂保护膜。因此，FeCl ₂摩擦化学膜提高了系统的润滑和抗磨损能力。在高温（200~350℃）下，FeCl ₂膜变厚，由于磨痕尺寸变大，接触区域压力变低，因此M50钢的磨损率增长与低温相比要小得多（ 22–150°C）。本研究的主要结果表明，CPSO润滑剂具有良好的抗磨和润滑能力，能够在高达350°C的温度下工作。