Heat Transfer and Fluid Flow During Laser Powder Bed Fusion of SS316L Stainless Steel

Abstract

Powder bed fusion using a laser-based (PBF-LB) process offers design freedom with an acceptable surface finish in several industrial applications. The judicial selection of the process parameters in the PBF-LB process can result in better performance of the additively manufactured products. The bead shape and size obtained in the PBF-LB process depend on the melt pool dimensions, while experimentally investigating the melt pool to understand the effect of PBF-LB process parameters is expensive and exhausting. Therefore, in the present study, melt pool dimensions are numerically envisaged for different process parameters to comprehensively understand the effect of various process parameters on the temperature distribution and molten pool size during PBF-LB of SS316L alloy. In this regard, a three-dimensional heat transfer analysis using finite element method (FEM) is attempted, and furthermore, the heat and mass transfer phenomenon in the molten pool during solidification is also analyzed utilizing finite volume method (FVM). A systematic comparison of the simulated results obtained from both methods is carried out in detail to understand the need to opt for FEM or FVM approach in predicting molten pool characteristics. The numerically predicted molten pool size is in good agreement with the experimental results.