Numerical simulation and experimental study on picosecond laser ablation of stainless steel

A fundamental study of the interaction between ultrashot laser and stainless steel will be useful in understanding the ablation characteristics and optimizing the ablation performance. A two dimensional finite element model consisting of two temperature equations, phase explosion mechanism and deformed geometry module was developed to simulate picosecond laser ablation of stainless steel. Single- and multi-pulse ablations with various laser fluences were simulated using the developed model. Thereafter, ablation experiments on stainless steel with the corresponding laser fluences and pulse numbers were conducted using a picosecond laser. It was found that the ablation depth and diameter increased with the increasing laser fluence under single-pulse irradiation. For multi-pulse ablation, the depth increased almost linearly with the increasing pulse number, whereas the ablation diameter changed a little. The predicted data overestimated the experimental ablation depths especially at high pulse number, but with the similar trend.