Study On The Tribological Behavior Of Laser-Textured 9Cr18 Surface Under Impact Sliding Condition

Aerospace bearings long-term work in high-speed,heavy load,vibration,high temperature and other harsh conditions,the cage and the collar of the guide surface is often affected by the impact of sliding coupling,resulting in damage to the oil film,And thus lead to the overall lack of bearing life.Surface texture as a way to effectively reduce the friction surface friction and wear,improve the lubrication of the means,has received more and more scholars attention.In this paper,the method of improving the wear performance of the bearing surface of the bearing surface is proposed,and the simulation of the hydrodynamic lubrication of the surface of the friction surface is carried out.The experimental study of 9Cr18 laser texturing and the friction under the impact sliding condition The influence of surface texture on the impact sliding friction process is studied,which provides the basis for the application of surface texture to rolling bearing.In order to study the hydrodynamic lubrication characteristics of friction surface,the finite element simulation model of surface texture was established by using COMSOL Multiphysics.The texture parameters(including shape,width,diameter,depth,etc.)and working condition parameters,The viscosity of the lubricating oil),analyzed the hydrodynamic characteristics of the surface texture,and explored the mechanism of the structure to improve the bearing capacity of the oil film.It is found that the pit diameter and the groove texture have the best depth ratio and aspect ratio respectively to make the oil film carrying capacity reach the maximum;The bearing capacity of the oil film increases with the diameter of the pit texture and the width of the groove texture.Different forms of groove texture have an impact on the oil film pressure,rectangular groove bearing capacity is strong.Using UV laser processing for 9Cr18 process test,processing straight groove and pits in the air.The results of the process test show that the mechanism of UV laser on 9Cr19 is mainly thermal ablation,and the geometrical dimensions of the texture are related to the energy distribution of the laser on the surface of the material.The width and depth of the groove increases as the laser power increases and decreases as the repetition rate increases,and the width and depth of the groove increases with decreasing scanning speed within a certain range.After the speed is reduced to a certain value,the width and depth are no longer increased.When the laser processing parameters change.The diameter and depth of the pit increases as the processing time increasesIn order to simulate the friction and wear properties of the bearing guide surface under the impact of sliding,the inner surface of the 9Cr18 ring was subjected to laser weaving treatment,and the impact sliding test was carried out under the oil-rich and oilThe wear characteristics of the surface texture under the impact sliding condition were investigated.The experimental results show that some of the texture parameters can play a role in anti-friction,but other textures play a role in increasing the friction,the texture can be improved to some extent when the oil condition is not good lubrication.