Analytical simulation of temperature distribution in selective laser melting using combined doublet and point solutions for a moving disk heat source

Abstract

This study presents a novel analytical model for simulating the selective laser melting (SLM) process. It integrates point and doublet moving disk-shaped heat sources to accurately resolve heat transfer dynamics between the laser beam and the near-surface layer of the powder bed. The model incorporates conductive heat losses within the powder bed, radiative and convective exchange with the surrounding gas, and evaluates the Marangoni force profile. This comprehensive approach enables computationally efficient predictions of melt pool temperature distribution and dimensions. Validation of the model against numerical data showed excellent predictive accuracy, with over 99 % agreement for the peak temperature at the top surface of the AlSi10Mg powder bed. When validated against experimental data, the model's reliability was further confirmed, yielding melt pool width and depth accuracies of 94.6 % and 88.1 % for AlSi10Mg, and 94.5 % and 85.3 % for Inconel 625, respectively. Parametric studies revealed that increasing the laser power from 150 W to 200 W significantly enlarged the AlSi10Mg melt pool, with the maximum depth rising from 22 μm to 32 μm. At 200 W and 800 mm/s, full powder bed penetration occurred, extending into the solidified layer. Conversely, slower scan speeds amplified Marangoni forces due to prolonged thermal exposure. By elucidating key process-physics relationships, this work provides a foundation for optimizing SLM parameters to enhance additive manufacturing outcomes.