Convection Heat Transfer Coefficients for Laser Powder Bed Fusion

This study investigates the effects of convection heat transfer during the laser-powder bed fusion (L-PBF) additive manufacturing process. For the L-PBF process, parts are fabricated under a purged, inert environment to avoid oxidation. Part of the delivered laser energy is transferred to the process chamber/environment through radiation and convection during fabrication. In this study, customized computational fluid dynamics (CFD) software is used to simulate the L-PBF of a single layer of stainless steel 17-4 PH. Local temperature and temperature gradients, as well as dimensionless numbers descriptive of important thermophysics, are provided in order to quantify local convective heat transfer. The results are used to predict local heat transfer coefficients during the L-PBF additive manufacturing process.