Analysis on Spatter Behaviour in Powder Bed Fusion Using Solid-gas Multiphase Flow Analysis
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Powder Bed Fusion (PBF), one of metal additive manufacturing process, is gaining attention as a promising technology that aligns with the goals of the sustainable development goals, enhancing product functionality and reducing lead time. PBF fabricates by repeatedly recoating layers and selectively melting and solidifying the powder with a laser beam. PBF comparably high fabrication resolution, resulting in spread of its applications aerospace and automobile industries. However, several challenges are still remaining, e.g., the adherence of spatter and fume to the build surface, which deteriorates the fabrication quality [1]. To address this issue, gas flow systems for spatter and fumes collection have been commonly implemented [2]. In this study, we aimed to improve the collection efficiency of spatter and fume in a PBF chamber using gas flow. For evaluting the influence of inert gas flow on the behavior of spatter and fume, a solid-gas multiphase flow analysis was conducted. A 3D model of the build chamber was developed for the simulation as shown in Figure (a). The simulation useded the characteristics of SUS316L as powder material, and argon gas as the inert carrier gas. The gas flow rate was varied from 500 to 3000 L/min, and different shepes of flow-path geometries were designed and examined (Figure (b)). In addition, experimental observations of gas and spatter behavior were conducted with digital camera to validate the simulation results. As a result, the simulation showed that increasing the gas flow rate and could enhance the collection efficiency of spatter and fume. The validity of analysis regarding gas and spatter behavior was indicated high collection through comparison with experimental data.