Molten pool macroscopic thermodynamic analysis during selective laser melting of AlSi10Mg: Simulations and experiments

In this study, the three-dimensional (3D) finite element model of COMSOL Multiphysics was used to simulate the thermodynamic behavior of the AlSi10Mg molten pool (MP) during selective laser melting (SLM), and the results were verified by multiple groups of single-track SLM experiments. The simulations take into account numerous thermophysical phenomena such as fluid flow, heat conduction, heat radiation, and fluid mass transfer. The influence of laser power, scanning speed, and other process parameters on temperature, shape, and size of MP was investigated. The simulated results and the experimental validation show that the model predictions are highly consistent with the measured data for most sets laser parameters, especially the MP width of 142 μm vs. 145 μm, depth of 53 μm vs. 56 μm at a laser power of 250 W and a scanning speed of 1000 mm/s, which confirms the reliability and accuracy of the model. Furthermore, the model innovatively forecasts the critical parameters for solidification in MP and delves into the intricate relationship between the position in MP and key parameters such as temperature gradient, cooling rate, and solidification rate. The model's versatility ensures its applicability to SLM simulation processes across diverse alloys and varying parameters. This research not only enhances our comprehension of SLM but also establishes a scientific foundation for optimizing processes, controlling microstructures, and enhancing material performance.