Tribological properties and bearing application of Mo-based films in space environment

Abstract

MoS2 film plays an important role in the field of space lubrication due to its excellent tribological properties, but the complex and changeable space environment has increasingly higher requirements for the lubricating layer. In order to improve the spatial tribological properties of the MoS2 film, the Mo-X (X = Pb, PTFE, C) binary composite films were prepared by radio frequency magnetron sputtering technology. Then, Mo/MoS2–Pb–PbS, Mo/MoS2-PTFE and Mo/MoS2–C films were obtained through the treatment of binary films by “low-temperature ion sulfurizing” technology. The structure, morphology and composition properties of the three films were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS).The tribological properties of the three films were tested through ultraviolet (UV), atomic oxygen (AO) and high-vacuum simulated space environment, and the results showed that the Mo/MoS2–Pb–PbS film has better comprehensive spatial tribological properties. The Mo/MoS2–Pb–PbS film was applied to practical bearings, which were simulated for life test after exposure to space environment. The wear life of the new bearing is an order of magnitude higher than that of the active bearing. Therefore, Mo/MoS2–Pb–PbS film has broad application prospects in the field of space solid lubrication.