Micro-texture Design Of Artificial Joint Surface And Its Wetting And Friction Characteristics

Artificial joint replacement has been widely used in clinical practice.Artificial joints have lost their self-lubricating mechanism,and problems such as joint failure and short life due to wear on the joint surface due to insufficient lubrication are still prominent.Therefore,it is of great significance to improve the lubricity and wear resistance of artificial joints.Microtexture has been used in the field of antifriction since it was proposed.Microtexture can not only change the contact type of the friction interface,but also change the wettability of the friction surface and regulate the adhesion of the lubricant to the solid surface.In this paper,microtexture is applied to the surface of artificial joints.The effects of microtextures on the friction characteristics of artificial joints are studied from both theoretical and experimental aspects.The main work is summarized as follows:(1)Based on the Reynolds equation,a hydrodynamic lubrication theoretical model of rhombic texture-surface is established,which is solved by Matlab programming,and the friction performance in the calculation domain is obtained.The influence of microtexture parameters on friction properties was analyzed.The conclusion is that the friction coefficient increases first and then decreases with the increase of the size and depth of the microtexture.There are optimal width and depth values to minimize the friction coefficient.(2)The effect of laser processing parameters on the size of the surface microtexture was experimentally studied.Matlab was used to fit the microtexture depth results to obtain a mathematical model between the microtexture depth and the laser processing parameters(number of markings,pulse frequency,output power,and number of scans).(3)Based on the classical contact angle model,The relationship between contact angle and adhesion was analyzed.The contact angle of the microtextured surface was measured,and the influence of the microtexture parameters on the contact angle was analyzed.It was concluded that increasing the size and depth of the microtexture in a certain range is beneficial to reducing the contact angle.(4)Under different lubrication conditions,the effects of microtexture parameters on the friction coefficient were studied by friction and wear experiments.The test results show that the bionic microtexture has anti-friction effect under the conditions of fluid lubrication and mixed lubrication.By changing the microtexture parameters,the friction behavior of the friction interface can be adjusted to reduce friction.