Effect of substrate surface texture on adhesion performance of diamond coating

Diamond coated tools are widely applied in the field of machining, however, its use is strictly limited by weak coating-substrate adhesion. As an effective method to generate functional surfaces, the technology of texture was applied in this research to try to change the distribution of interfacial stress and improve the adhesion of coating substrate system. Micro-textures with different densities and shapes were prepared on the surface of cemented carbide (YG6) by ultraviolet nanosecond laser, and heteroepitaxial growth of diamond coating on textured surface was realized by hot filament chemical vapor deposition (HFCVD) technology. By means of Rockwell indentation tests, micro-Raman spectrometer and thermo-solid coupling simulation analysis, the effect of textures on the adhesion of diamond coating was studied. Results indicate that the adhesion of coating-substrate increases with the increase of the micro-textures density. The normal compressive stress of diamond coating at the edges of texture inhibits the propagation of interfacial cracks, resulting in the deviation of the crack propagation path.