Study on the Rate of the Removal of Nano-Crystalline Diamond-Coated Materials by Femtosecond Laser Etching

The rate of the removal of materials coated with nano-crystalline diamonds by femtosecond laser etching was examined by adjusting the repetition rate of the femtosecond laser, the energy-flux density of the concentrated spot, and the scanning speed. The observational results of the white-light interferometer and the numerical fitting approach were used to develop the removal rate function model of the nano-crystalline diamond-covered material etched by the femtosecond laser. The findings demonstrated that the rate of material removal was not greatly affected by the repetition frequency and that the amount of laser energy accumulated over time on the coated surface is steady. The processing outcomes under different laser scanning speeds are different, and the material removal rate tends to increase and then decrease with an increase in scanning speed. The greater the energy-flux density of the focused spot, the greater the etching intensity, and the greater the material removal rate. With an increase in scanning speed, the rate at which the material is removed often rises initially before falling.