Publications

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Authors: Gowthaman Parivendhan, Philip Cardiff, Thomas Flint, Željko Tuković, Muhannad Obeidi, Dermot Brabazon, Alojz Ivanković

Abstract: Mathematical models provide valuable insight into the Laser Beam (opens in a new window)Powder Bed Fusion (PBF-LB) process. (opens in a new window)Numerical modelling of the PBF-LB process and the influence of the process parameters on the melt pool topology are presented in this study. A one-way coupled model using (opens in a new window)Computational Fluid Dynamics (CFD) and (opens in a new window)Discrete Element Method (DEM) is adopted to model the particle distribution in the powder bed and the melt pool formation and dynamics due to (opens in a new window)laser irradiation during the PBF process. The DEM method is used to model the interaction between particles in the powder bed, and CFD is used to simulate the melt pool formation, flow and solidification. The Volume of Fluid (VoF) approach was used to model the three phases. The effects of surface tension, (opens in a new window)Marangoni convection and (opens in a new window)recoil pressure at the metal/gas interface were included in this model. The predicted melt pool dimensions for various process parameters are validated against the experimental data. The different pore-forming mechanisms in multi-track, multi-layer cases and the effect of actual layer thickness are investigated. The proposed modelling approach is shown to capture the dominant physical mechanisms of the PBF-LB processes, potentially being used as a tool to understand process-structure–property relationships and aid in process optimisation.