Computationally inexpensive semi-analytical thermal model to predict melt-pool dimensions for a single-track in selective laser melting

Abstract

Selective laser melting (SLM) has recently gained momentum as a state-of-the-art manufacturing process capable of building highly customized products. Localized heat input and short interaction time of laser beam intensify thermal gradient and deteriorate the part's quality due to thermal stresses and uncontrolled distortions. An algorithm is proposed that comprises of analytical solution for volumetric moving heat source combined with numerically formulated conduction and convection cooling to estimate the temperature distribution and melt-pool geometry during the SLM process. Fully implicit finite volume equations are framed with appropriate part boundary conditions for the two-dimensional domain and iteratively solved by Alternating Direction Implicit (ADI) method. The proposed methodology has shown the potential to develop a deep understanding of this dynamic process and deliver results at low computational costs. Simulations for single-track melting have been studied by changing the process parameters, and phase change from powder to solid is well exhibited by adopting temperature-dependent material properties. The proposed model has been validated by experimental data from the literature for two alloys - Inconel 718 and SS316L.