Parametric Study of Inverse Heat Source Model Based on Molten Pool Morphology for Selective Laser Melting

Abstract

In the selective laser melting preparation process, an accurate description of the temperature field is essential for improving the accuracy of finite element simulations of the forming process and mechanical property predictions, as well as for the reliable basis of process parameter control to ensure product quality. A novel finite element updating method based on image recognition of melt pool morphology is proposed for the Goldak double ellipsoid heat source model, which is known to have multiple unknown parameters that are difficult to determine. Finite element computational models of surface heat source, Gaussian body heat source, and Goldak double ellipsoid heat source are established, respectively, to describe the temperature field of selective laser melting. The reliability and applicability of the finite element prediction results are verified through experiments. Finally, the temperature field distributions, melt pool morphology, and dimensions of the model predictions are analyzed to further validate the reliability of the Goldak double ellipsoid heat source model obtained by inversion method.

Keywords: Selective laser melting, Inverse problem, Heat source parameters, Molten pool, Microstructure