Study On The Tribological Properties Of Adhesive Solid Lubricating Coatings

The bonded solid lubricating coatings were prepared by spray method. The effects of the coating composition and prepared technology on the tribological properties and load capacity were investigated. The tribological behavior and wear mechanism of the coatings were also analyzed.Firstly, the amount of curing agent in the coatings, the best curing temperature and coupling agent treatment were determined by the test results of marking strength and friction and wear. The tribological properties and load capacity of the coatings with graphite, MoS2 and the mixture of graphite and MoS2 under increased loads with or without oil lubrication were tested in order to obtain the optimal composition of the coatings. A proper ratio of graphite to MoS2 will show a obvious synergistic effect. And the tribological properties of the coatings with the two solid lubricants are obviously better than those of the coatings with single solid lubricant. Furthermore, the results showed that the best ratios of graphite to MoS2 in oil and oilless conditions are different: in oil lubrication somewhat more graphite is beneficial to the tribological properties, while in oilless condition somewhat more MoS2 is beneficial to the tribological properties.Secondly, the tribological behavior and wear mechanisms of the bonded lubricating coatings under dry friction conditions (oilless) were further studied. A protection lubrication film on the coating surface and transfer films on the counterface were gradually formed in the action of thermal stress and contact stress. And the friction of the couples gradually changed into the friction of the protection film and the transfer film, at this time, the coating has excellent tribological performance. A proper increase of sliding speed and load is beneficial to the formation of the protection film and transfer films. However the high sliding speed and load will lead to the surface crack formation and propagation resulting in the decrease of the tribological properties and load capacity. In the condition of higher load and lower sliding speed or lower load and higher sliding speed, the bonded solid lubricating coatings have better tribological properties and durability.