Research on the influence of diamond coating microtexture on graphitization law and friction coefficient

The micro-texture of the CVD diamond coating has the function of holding wear debris, and can reduce the friction coefficient of the cutting tool through graphitization to a certain extent. In order to investigate the influence of diamond coating micro-texture on the graphitization law and friction coefficient, the graphitization law test of diamond coating with different texture morphology, areal density and depth and the friction test of diamond coating with micro-texture were designed and carried out. It is found that the degree of graphitization of the diamond coating micro-texture decreases in the order of concentric circles, hexagonal, and diamond-shaped ribs. At the same time, it is also positively correlated with the areal density of the micro-texture. The depth of the texture has a weak positive effect on the degree of graphitization. Graphitization of the textured surface can rapidly reduce and stabilize the friction coefficient at the initial stage of friction. After stabilization, the friction coefficient of the diamond coating decreases with the increase of the degree of graphitization. The research results of the paper have high theoretical significance and practical value for expanding the application range of diamond coating and improving the service life and machining accuracy of diamond coating tools.