Numerical Calculation And Experimental Study On Textured Surface Tribology Performance Under Mixed Lubrication

Friction and wear seriously reduce the utilization rate of energy.Surface texture technology3,as a feasible technology to improve tribological property,has important application value in transportation,mechanical manufacturing,aerospace industry and other fields.Under mixed lubrication condition,the interface of the friction pair consists of the direct contact of the rough peak and the support of the lubricating oil film.The proper micro-texture could bring the effects of "secondary lubrication" and "microfluidic dynamic pressure",how to construct a specific textured surface to improve the tribological property of the interface of the friction pair has been the key to surface texture technology.In order to understand the mechanism and regularity of the influence of the geometrical parameters and directional parameters of the textured surface on the friction and lubricaltion performance,this thesis could provide theoretical guidance for the design of the textured surface.Research is carried out in four aspects:theory,simulation,preparation and experiment,to explore the design parameters of the tribological performance of the textured surface under mixed lubrication regime.The main work and conclusions include:(1)The average Reynolds equation is used as the governing equation of the friction pair interface lubricating fluid,and the GW(Greenwood Williamson)contact model is used to calculate the friction generated by the rough peak contact and movement.From the point of view of numerical calculation,the discretization processing of the control equation is combined with the periodic boundary conditions to solve the friction lubrication performance parameters,and the program is completed by Matlab language.(2)Numerical calculation of the influence of texture area ratio Sp.radius R、depth dp rough surface direction parameter y and texture direction on tribological property,is completed.Under the test conditions,the results show that the optimal geometric parameters of circular texture are 20%texture area,100μm radius and 17μm depth;Three typical rough surface direction parameters have significant influence on tribological property,the isotropic rough surface(γ=1)has the best performance,and longitudinal rough surface(γ=9)produces the worst performance;To the ellipse,along the short axis of the ellipse produces better tribological property,and along the long axis has poor tribological property.(3)The preparation process of rough surface and micro-texture array on tin bronze material by nanosecond UV laser was explored.The controllable construct of surface roughness and direction was preliminarily realized,and different geometric features that circular and elliptical micro-textured arrays in a specific direction were successfully prepared.(4)The friction lubrication test was designed.The UMT-2 friction and wear tester on rotary part is used to simulate relative sliding via pin-to-disk between the friction pairs.The regularity of the surface texture and direction parameters affecting the tribological property was tested.The corresponding friction coefficient results of different circular texture geometric parameters、rough surface direction parameters and elliptical texture direction are obtained.The experimental results are in good agreement with the numerical results,which verifies the reliability of the numerical results.