Bai, X., Tang, C., Gao, S., Tran, V.-T., Zhou, K., & Du, H. (2025). Multiphysics modelling of pulsed-wave laser powder bed fusion. Additive Manufacturing, 109, 104833. https://doi.org/10.1016/j.addma.2025.104833
Abstract:
A fundamental understanding of process–structure–property correlations is crucial for improving the performances of metallic materials produced by additive manufacturing. In laser-based powder bed fusion (PBF-LB) process, compared to the conventional continuous-wave mode, the implementation of pulsed-wave mode has advantages such as less heat accumulation, fast cooling rates, and improved mechanical properties. However, the correlations between process parameters and as-built quality remain underexplored for pulsed-wave PBF-LB. In this study, we fill this gap by developing a computational fluid dynamics (CFD) model coupled with a cellular automaton (CA) model to investigate the influence of pulsed-wave laser on heat transfer and microstructure evolution in the melt pool. Several parameter sets including varying frequencies and scanning speeds were arranged to conduct numerical simulations and to print both single-track and cube stainless steel 316L samples for experimental validation. The predicted surface roughness, melt pool depth, print defects, cellular structures, and grain structures show good agreement with experimental measurements, with a maximum relative error of 17%. In our demonstration cases,S the application of a pulsed-wave laser increases the colling rate by at least 9%. The cooling rate increases at an approximate rate of 0.5 HZ·μs/K with decreasing laser frequency, leading to the formation of finer cellular and grain structures. This research offers new insights into the role of pulsed-wave PBF-LB in reducing process defects, controlling microstructures, and enhancing material properties.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
This research / project is supported by the National research foundation Singapore - Medium-Sized Centre funding scheme
Grant Reference no. : N.A