Investigating the ablation depth and surface roughness of laser-induced nano-ablation of CVD diamond material

Abstract The CVD diamond material with high wear resistant has been frequently used as the material of micro mills. The laser-based pre-treatment of CVD diamond has been identified as a favorable technique for subsequent precision machining in terms of efficiency and surface quality. This study is aimed to investigate the effect of CVD diamond material on the ablation depth and surface roughness (Sa and Sz) in laser-based machining, so as to improve the overall machined surface quality. Controlling ablation depth and high surface finish are the key indicator for the follow-up accurate treatment. In addition, the energy density distribution (EDD) model was established to better explain the microstructural changes in CVD diamond material after performing the laser machining. Through EDD model, the variation in ablation depth and surface roughness were evaluated at different laser parametric levels. The results showed that the ablation depth and surface roughness of EDD model are basically consistent with the experimental values. Moreover, at the same total energy density, the ablation depth and surface roughness Sa and Sz values are lower under the condition of low average laser power, large filling pitch and small laser scanning speed. In a nutshell, minimum surface roughness and a controlled ablation depth are achieved on CVD diamond by adjusting laser parameters.