Tool anisotropic wear prediction and its influence on surface topography in diamond turning of oxygen-free copper

Oxygen-free copper components are widely used in high energy physics engineering, which are usually fabricated by the diamond machining process for achieving low roughness surface. However, the wear of diamond tool heavily affects the surface quality. In this work, the wear law of diamond tool in machining of oxygen-free copper is studied with consideration of the anisotropy of diamond strength. Firstly, the stress distribution on the tool face in machining is calculated. The results show that the cutting stress near the flank face is larger than that near the rake face. Secondly, the strength distribution of tool cutting edge is modeled. The theoretical prediction reveals that the anisotropy of diamond crystal leads to the great differences in the strength of cutting edge at different positions, and further affects the cutting edge wear resistance. Thirdly, the wear model of diamond tool is established with consideration of cutting stress distribution and tool edge strength, in which the mechanical wear is the dominant wear process. Finally, the variation of the surface roughness is analyzed on the basis of the tool wear through the cutting experiments. The experiment results indicate that the surface material deformation is closely related to the tool cutting edge wear transition area and results in different values of surface roughness. The obtained results can improve the understanding of the diamond tool wear law and estimate the diamond tool wear in machining of oxygen-free copper.