Tribology Properties And Wear Mechanism Of Water Lubricated Bearing Materials

Instead of lubricating oil by water on the one hand has low cost,recycling,reliable,on the other hand,can avoid pollution caused by leakage of lubricating oil.This makes the water to be the most promising lubricating medium.Polymers are being increasingly used in the field of tribology because of their low frictional coefficient,light weight,high strength,and erosive resistance in comparison with metal.In this paper,friction and wear properties of epoxy resin and polyacetal matrix composites under water lubricated conditions is studied.It provides an important theoretical and experimental basis of polymer matrix composites in the application of hydropower,shipping,marine operations and how to improve the service life and so on.For the purposes of improving the tribological properties of epoxy resin and polyoxymethylene.Analysis of composite both friction and wear properties of two composite system under water lubrication conditions have been analyzed.A in-depth analysis of transfer film were carried out in this dissertation.The main work and conclusions are as follows:Using MRH-3 type wear tester,friction couple were immersed in water,friction and wear properties of epoxy composites is investigated.The influence of the speed,various fillers on friction and wear properties of epoxy resin has been discussed.The two fibers have improved to varying degrees of epoxy resin material,carbon fiber is more suitable than glass fiber in water lubrication.Nano-silica is more suitable than the graphite for play synergistic effect with carbon fibers.Roughness size has a profound impact on the wear rate and lubrication changing.Wear rate and mixed lubrication state length in the percentage of speed range proportional to the size of roughness.Hydrodynamic lubrication state length in the percentage of speed range inversely proportional with the size of roughness.Composition of transfer film were analyzed.The cross section of the wear surface was got by focus ion beam and TEM,the composition,structure of a high quality transfer film which generated in experimental process was analyzed.The transfer film has a multilayer structure,composition of transfer film which contain a large amount of silica,iron oxide,and amorphous carbon.The anti-friction in reducing friction resistance effect of transfer film have been verified.Using M-200 type friction tester,friction and wear properties investigated POM matrix composites is investigated under water drip lubrication conditions,the impact of the two kinds of reinforced material on the friction and wear properties of POM were compared.The two fibers have improved to varying degrees of epoxy resin material.But wear rate of aramid pulp reinforced POM composites is smaller.Although the supporting role of the carbon fiber is stronger than aramid pulp,but not as good as the bonding properties of aramid pulp with the matrix material.The friction and wear properties of conventional solid lubricant PTFE and h-BN filled POM material is compared.h-BN can accelerate the crystallization rate of POM.h-BN has a stronger improvement on the tribological performance of POM than PTFE.The composition and mechanism of transfer film formed on the dual surface have analyzed.It is believed that the mechanical friction and chemical reactions are important factors in forming a lubricating film.The component of Transfer film is boron oxide,polyoxymethylene,and boron nitride particles.the synergistic effect of two fibers and boron nitride particles on improving tribological properties has examined.the boron nitride particles have better synergies with carbon fibers.