Study On Temperature And Scuffing Properties For The Sliding Friction Pair On Considering Oil Additives

Scuffing is one of the main failures of material surface with big destruction; it appears mainly in sliding contact friction pairs under high-speed and heavy-loaded conditions. From the early 1930, theoretical analyses and experimental studies have been performed and many scuffing models have been developed; however none of these models could effectively interpret the complex phenomena observed in the scuffing experiments.The abrupt change in temperature is one of the main characteristics in scuffing. Studies have showed that friction pair temperature plays an important role in scuffing. Therefore, study temperature in friction pairs is significant to the research on scuffing.This paper studied the properties of line contact sliding friction pairs and the effects of many factors have been experimentally studied in details. Experiments were conducted to study the effects of additives in lubricating oils on the wear and scuffing resistant capability of sliding friction pairs. The results showed that the root-mean-square deviation (σ) in surface roughness has a significant effect on the critical scuffing load. There is an optimum σ, at which the surface scuffing load is maximum. Also, surface roughness has an effect on frictional coefficient and there is also an optimum σ, at which friction coefficient is minimum.The change in friction pair temperature with changing load has same trend as that of frictional coefficient and temperature increases with increasing frictional coefficient.The scuffing-resistant capability of friction pairs is enhanced with reducing sliding velocity. The additives T302,C9H21BO3,Lanthanum Borat Nanoparticle and CaCO3 Nanoparticle were studied to examine the effect of additives on the scuffing-resistant and friction –resistant capability of sliding friction pairs. The results showed that additives tend to improve friction-resistant capability of sliding friction pairs, enhance lubricating property of lubricating oil, and reduce frictional coefficient. The change in friction temperature is consistent with that of frictional coefficient. Frictional heat directly leads to the increase in friction pair temperature. Different additives have different mechanisms of increasing the scuffing and friction resistant capability of sliding friction pairs. In addition, numerical method was applied to study the temperature field in friction pairs under different operational conditions. The results showed that the surface temperature of friction pairs has a significant effect on scuffing. There is a critical temperature, under which no scuffing occurs. Friction pair temperature distributes symmetrically along the contacting line and the temperature at friction pair interface is highest. The critical scuffing temperature of friction pairs is not constant and changes with the friction pair operational conditions.