Reseaerch On Loading Characteristics And The Correlation With Grease Of Solid Lubricating Films On 9Cr18 Steel Surface

With the development of space industry in China, the working condition of space machine bearings is more and more severe. Therefore, putting forward higher requirements about the reliability and lifetime of lubrication. In recent years, more and more surface technology is applied to precision bearing. The practice shows that the surface modification can prolong the bearing life and reduce the friction torque. The current commonly used bearing surface modified technology include ion implantation, physical vapor deposition(PVD), chemical vapor deposition(CVD), physical and chemical gas phase deposition(PCVD) and laser surface strengthening method. Nowadays, more scholars began to composite use surface modification and liquid lubricants(lubricating oil and grease). In order to guarantee the composite lubrication of film and lubricant in the aerospace demanding environment, it is necessary to study the friction and wear characteristics of the composite lubrication when they are compounded.In this paper, research the friction and wear characteristics of 9Cr18 steel surface with N ion implantation, magnetron sputtering plating DLC film and Mo S2 film under different conditions by the experiment, test, theoretical analysis, and other means. Then, analysis the anti-friction and anti-wear properties of 9Cr18 steel surface film. Thus, it can provide the experimental basis for the application of 9Cr18 steel surface film and the compound lubrication of lubricating grease.The friction and wear properties of the thin film were related to the structure and properties of the film. Firstly, research the surface mechanics and composition of 9Cr18 steel surface film. From the perspective of materials science, analysis the modified layer element concentration and phase structure by XPS, and use SEM and energy dispersive spectrometer to observe the change of layer elements distribution, using nano-indentation method measurements the mechanical properties of change layer hardness and elastic modulus of surface film intrinsic. And providing theoretical basis for the analysis of the friction and wear characteristics of the modified layer.Film surface of the friction and wear properties not only refers to the surface mechanical properties and composition of surfaces, but also to the bonding strength of surface film and the substrate. This paper will use the nano-scratch method to research the bonding strength of the 9Cr18 surface plating DLC films and Mo S2 coating, which bearing the normal load and tangential force at the same time. At the same time, the failure mode of the solid film is analyzed by combining the formation of the scratch forming process and the recovery degree, which can provide the theoretical basis for the practical application of the solid film.This research focused on the friction and wear characteristics of the 9Cr18 film and the grease lubricated condition. According to design parameters, analysis the friction and wear characteristics of 9Cr18 steel plate surface with N ion implantation, the DLC films, coated Mo S2 film and composite grease lubrication in different loads and surrounding environment(vacuum / air). And study the wear form of film surface under different conditions by SEM and energy dispersive spectrometer, and find the bearing boundary and the composite effects of films with grease lubrication film surface.