In Situ Optical Observation And Theoretical Analysis Of Soft Three-Body Friction Interface

Due to the presence of wear particles, solid lubricating medium, and grinding grain, the actual contact surface often form the situation of three-body contact. While most of the surface contact theory and experiment research stay in two-body contact. Lubrication of three-body particle is widely used in engineering fields, but for the asperity randomness distribution and particle movement disorder, three-body contact theory fall behind demand.In order to establish three-body contact model and theory, first of all, utilize in-situ observation to observe the three-body friction interface of real-time dynamic, which under specimen is optically transparent that can observe the surface roughness, load, sliding speed, amount of powder effect to powder’s damage forms, destruction process and area ratio. Especially, analysis the factors of adhesion effection presence and size; on the other hand, in situ observation of three-body experiments provides a reliable basis for theoretical research.Secondly, set up a three-body particle contact model, based on Reynolds equation, viscosity equation, GW models, analyze particle concentration, particle diameter, surface morphology, elastic modulus have an effect on interface, and analyze film thickness, surface roughness, load effection.Finally, combined simulation results, to discuss film thickness, surface roughness, load impact to pressure and friction distribution, and verify correction of the simulation results. The results show that:destruction process of three-body including five stages, which is powder complete, partial damage, destruction proliferation, adhesion damage, complete destruction, and adhered destroy is existed when roughness and load is large. Asperity, texture and thickness is simulated to research three-body contact process, asperity and texture affect each other effect the distribution of pressure and friction. Those can choice reasonable roughness and texture direction to improve the bearing and reducing friction force, so that the powder layer has better anti-friction and anti-wear properties. There are the destruction forms of three-body, destruction process combined with the simulation results, to analyze mechanism of destruction forms and destruction process.