Research and application of bonded solid lubricating coatings (4)

3 domestic bonded solid lubricating coatings New progress of basic research applications <br> <br> solid lubricant coating domestic bond major research and production units are Lanzhou Institute of Chemical Physics. In recent years, the Institute’s urgent need for high-performance bonded solid lubricant coatings for the use of high-tech models of the national defense industry for extremely harsh working conditions and the inability of existing bonded solid lubricant coatings to meet the requirements of use have been focused on At the same time of the development of the model supporting special bonded solid lubricant coating materials, relevant application basic research was carried out for the difficult problems encountered in the application research work. The basic idea is to focus on the basic factors affecting the tribological properties of coating materials. On the basis of selecting or synthesizing high-performance raw materials, the compatibility matching characteristics and composite synergy between the components in the coating are investigated. The effects of coating lubrication and failure mechanisms were investigated to find ways to improve the tribological properties of the coating. The results of the study have played an important role in guiding the development of high performance bonded solid lubricant coatings.

3.1 Interaction and synergistic effects between multiple components in the coating

It has been found that in bonded solid lubricant coatings, some components have a negative effect, such as graphite and polytetrafluoroethylene, graphite and nylon, while other components have synergistic effects, such as graphite and MoS2, MoS2 and PTFE, etc., which are used in combination with an appropriate ratio, can significantly improve the antifriction and antiwear properties and load carrying capacity of the lubricating coating. The results of the composite effect of various rare earth compounds with MoS2 show that the composite addition of rare earth fluorides such as LaF3 and CeF3 and MoS2 in the bonded solid lubricating coating can greatly extend the wear life of the coating. For example (see Figure 4), the mechanism is that LaF3 has the effect of inhibiting the oxidation of MoS2, and at the same time can form the MoS2·nLaF3 structure. LaF3 bonds with MoS2 on the active MoS2 facet, preventing the bonding of MoS2 with oxygen and water. Opportunity, but does not destroy the layered structure of MoS2, so it has a synergistic effect. In order to solve the problem of oxidative wear of MoS2 lubricated coating and the electrochemical corrosion of graphite coating on metal substrate, we also synthesized oil-soluble organic rare earth compound di-n-butylphosphonium bromide (BuC) and added it to MoS2. In the bonded solid lubricating coating with graphite, it was found that due to the solubility of BuC in the solvent, it is enriched at the surface of the bond coat and the interface with the substrate, thereby preventing the action of air and MoS2, while It also inhibits the electrochemical action of graphite on the surface of the metal that is passivated by BuC, improving the tribological properties and corrosion resistance of the bonded solid lubricating coating (Fig. 5). We have also found that the wetting and dispersibility and matching stability of fillers and solid lubricants in binder systems have an important influence on the quality of coatings. Pretreatment of solid lubricants and fillers, such as irradiation, surface activity Agent treatment, coupling agent treatment, etc., can change the surface group properties and surface energy, etc., so that the compatibility with the resin system is fundamentally improved. The above research results lay the foundation for the development of high performance bonded solid lubricating coatings using the interaction of various components.

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