Dimple prediction modelling in ultrashort laser processing: A benchmark study on ablation threshold determination methods and incubation models

Abstract

The appropriate selection of ultrashort laser processing parameters is a complex task in which prediction models based on the logarithmic ablation law derived from the Two-Temperature model are commonly used to minimize experimental effort. Although the model's accuracy depends on the threshold fluence ( ) and energy penetration depth ( ) values used, which evolve with the number of pulses (Np) due to the incubation effect, there is no consensus on the optimal determination method or incubation description. A benchmark on ablation threshold determination methods and incubation models was conducted on stainless steel to (i) analyse their effects on and and (ii) evaluate the impact on diameter and depth prediction errors of multi-shot dimples. Four ablation threshold determination methods and four incubation models, along with their variants, were identified. This resulted in a total of 24 combinations, referred to as estimation approaches. For a single pulse, varied up to 73 % depending on the estimation approach, whereas was less sensitive, with differences up to 40 %. Regarding prediction errors, they remained below 12 % for diameter across all estimation approaches. Depth prediction errors exhibited greater sensitivity, ranging from 11 % to 33 %. This study emphasizes the importance of the estimation approach used for both ablation threshold and incubation parameter determination and its impact on the multi-shot dimple prediction accuracy.