High-performance phase-field lattice Boltzmann simulations for accurate thermal fluid flow in metal additive manufacturing

To enhance the performance of metal additive manufacturing (AM) products, it is crucial to accurately predict and control the solidification microstructure and defects formed during laser scanning. Numerical simulations are essential to achieve this goal. In this study, we developed a high-fidelity model and large-scale computational method combining the phase-field and lattice Boltzmann method to accurately predict the thermal fluid flow dynamics in the melt pool, which significantly affects the solidification microstructure and defect formation. The developed computational method reproduced steady-state melt pool dynamics within a realistic computation time using high-resolution grids that were previously unusable. Furthermore, the effects of grid resolution on melt pool dynamics were evaluated. The results demonstrate that the flow behavior in front of the keyhole is crucial for the overall melt pool dynamics, and achieving a high-accuracy flow representation in this region requires a high grid resolution. This method is expected to contribute significantly to the prediction of solidification microstructure and defects in metal AM.