Modelling of laser powder bed fusion process for different type materials

The main problematic coming from the Laser Powder Bed Fusion (L-PBF) technique is the achievement of a fully dense part out of the interconnected tracks. The correct choice of process parameters is of fundamental importance to obtain a porosity free component. In this work, a model is described as able to simulate the printing process. The proposed model is a simplified numerical tool for designing processing windows suitable for metal alloys of any composition. The considered approach makes the model used as much practical as possible while keeping the physical description representative. The model is validated fitting experimental measures of track width, depth and cross-sectional area taken from three literature sources, referring to Ti6Al4V, Inconel 625 and Al7050. Effective liquid pool thermal conductivity, laser absorptivity and depth of application of laser energy are here considered as fitting parameters. Laser absorptivity and depth of application of laser energy result to rise almost linearly with increasing specific energy; the slopes of the three analyzed alloys result very close to each other. The obtained results give confidence about the possibility of using the model as a predicting tool after further calibration on a wider range of metal alloys.