laserbeamFoam: Laser ray-tracing and thermally induced state transition simulation toolkit

Flint, Thomas; Robson, Joseph D.; Parivendhan, Gowthaman; Cardiff, Philip

doi:10.1016/j.softx.2022.101299

Cited by 11 publications

(1 citation statement)

References 18 publications

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“…In view of the situation described above, simulation studies of L-PBF have increased in the last decade. For example, heat transfer analysis, which considers changes in physical properties associated with the phase change between solid and liquid metals [6,9,21]; elastoplastic simulation for evaluating residual stresses [9,22,23]; and multiphysics analysis which involves fluid dynamics, heat transfer considering solid-liquid-gas phase change, and laser ray tracing using multiphysics computational fluid dynamics (CFD) simulation [24][25][26][27][28][29][30][31][32][33]. The use of multiphysics CFD simulation has shown promise in predicting defect formation.…”

Section: Introductionmentioning

confidence: 99%

Particle Size Effect on Powder Packing Properties and Molten Pool Dimensions in Laser Powder Bed Fusion Simulation

Katagiri,

Nomoto,

Kusano

et al. 2024

JMMP

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Various defects are produced during the laser powder bed fusion (L-PBF) process, which can affect the quality of the fabricated part. Previous studies have revealed that the defects formed are correlated with molten pool dimensions. Powder particles are thinly spread on a substrate during the L-PBF process; hence, powder packing properties should influence the molten pool dimensions. This study evaluated the influence of particle size on powder packing properties and molten pool dimensions obtained through numerical simulations. Using particles with different average diameters (Dav) of 24, 28, 32, 36, and 40 μm, a series of discrete-element method (DEM) simulations were performed. The packing fraction obtained from DEM simulations became high as Dav became small. Several particles piled up for small Dav, whereas particles spread with almost one-particle diameter thickness for large Dav. Moreover, the packing structure was inhomogeneous and sparse for large Dav. As a result of multiphysics computational fluid dynamics (CFD) simulations incorporating particles’ positions as initial solid metal volume, the molten pool width obtained was hardly dependent on the Dav and was roughly equivalent to the laser spot size used in the simulations. In contrast, the molten pool depth decreased as Dav decreased. Even if the powder bed thickness is the same, small particles can form a complex packing structure by piling up, resulting in a large specific surface area. This can lead to a complex laser reflection compared to the large particles coated with almost one-particle thickness. The complex reflection absorbs the heat generated by laser irradiation inside the powder bed formed on the substrate. As a result, the depth of the molten pool formed below the substrate is reduced for small particles.

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