Simplified method for predicting melting and ablation process parameters during laser surface treatment of metals and alloys

Abstract

In this paper, a simplified analytical solution to predict melting and ablation process parameter thresholds for short-pulsed laser irradiation is developed and applied to common metals and alloys, including aluminum, copper, titanium, stainless steel 316, and zirconium. The new approach utilizes material parameters at only two temperatures: room temperature and the material melting point, by introducing a new parameter called the Intensity Fluence Factor (IFF). Specifically, it considers density, specific heat capacity, thermal conductivity, and reflectivity to predict various thresholds for the given laser parameters (i.e., intensity and fluence). The IFF removes time dependency from the laser parameter to clearly demonstrate the temperature rise of the material, predicting phase transformation. This provides an initial predictive framework, offering a practical guideline for experimental setups. The generality and applicability of this method are examined through comparisons with Finite Element Method (FEM) models that incorporate fully variable temperature-dependent material properties. The Intensity Fluence Factor (IFF) introduced in this study and the associated prediction method demonstrate versatility across short-pulse laser processing conditions and material types. Furthermore, the derivation of this simplified analytical solution shows the equivalence between fluence and intensity with respect to achieving peak surface temperatures. The method helps in the optimization of laser irradiation parameters, namely, laser pulse fluence and intensity, which is especially beneficial in industrial contexts where laser parameters can be constrained by variability across different manufacturers.