Tribological Performance and Lubrication Mechanism of Solid-Liquid Lubricating Materials in High-Vacuum and Irradiation Environments

摘要

In this paper, six solid-liquid lubricating materials have been prepared based on two kinds of liquid lubricants including perfluoropolyethers oil (PFPE) and chlorinated-phenyl and methyl-terminated silicone oil (CPSO) and three different solid lubrication materials [polyimide (PI), polytetrafluoroethylene and Cu-based alloy] by the dip-coating method. The tribological behaviors of these lubricating materials were comparatively investigated in high-vacuum condition. The results showed that the polymer-based solid-liquid lubricating materials exhibited the excellent tribological properties, which mainly attributed to the hydrodynamic lubrication. Moreover, as for the same solid substrate, the smaller the value of the steady-state contact angle was, the higher the friction coefficient was. Meanwhile, the effect of atomic oxygen (AO) and proton (H+) irradiations on structure and tribological properties of the PI/CPSO and PI/PFPE was further investigated in this work. The experimental results indicated that irradiations induced the degradation of the lubricating oil, which resulted in the increment of the friction coefficient and wear rate, thus decreasing the lubricating performance. In addition, the effect induced by H+ irradiation was more serious than that by AO irradiation. PI/CPSO solid-liquid lubricating material has good irradiation stability compared with PI/PFPE.