Numerical Simulation of Femtosecond Laser Ablation of 304 Stainless Steel

The ablative effect of femtosecond laser on 304 stainless steel was investigated by using the double temperature equation. The distribution of the electron-lattice system temperature under the action of single-pulse and the relaxation time required to achieve equilibrium was numerically simulated, the ablation threshold of the material was calculated, and the variation of ablative depth and ablative radius under different energy densities were derived. The cumulative effect of energy during multiple pulses action under different periods was analyzed. The concept of overlap rate was introduced to compare the relationship between the ablative depth in the overlap area and the ablative depth in the centre of the spot at different overlap rates, which provided theoretical support for subsequent laser processing experiments.