Ablation threshold estimation for femtosecond pulsed laser machining of AISI 316L

The diffusion of laser machines based on femtosecond and picosecond pulses is increasing in industry, thanks to their capacity of performing high precision, nano-scale machining operations, and to their applicability to a wide variety of materials. The quality of the obtained products depends heavily on the selection of proper machine parameters, which is a non-trivial task for such a nonlinear, multi-physics dependent process. In this work, we propose a new regression approach for the characterization of ablation threshold and incubation factor, which are the key parameters required for defining process recipes in ultra-short pulsed laser machining. The proposed method is applied to the estimation of these parameters for stainless steel AISI 316L, basing on hole drilling data measured by optical microscopy.