Thermal Profile Modeling and Microstructural Evolution in Laser Processing of Inconel 625 Plates

Abstract

Thermal modeling is used in additive manufacturing laser processes to predict microstructural evolution of the materials under specified process conditions and parameters. The objective of this study was to develop, analyze and compare two predictive models: an analytical model and a numerical model for laser processing of materials of Inconel 625. These models were compared with experimental results for thermal profiling, and the effect of thermal profiles on microstructure of the experimental samples was explored. The three approaches; analytical modeling, numerical modeling, and experimental results were evaluated against thermal profile histories and correlated to microstructural evolution in laser processing. Maximum temperatures in the thermal profile of both models were shown in good agreement when compared to the experimental results. Cooling curves were also correlated with microstructure in terms of grain size, morphology, orientation, and texture evolution, with findings that match previously reported results. This research validates the proposed numerical model for examining optimal laser processing conditions for IN625 through both thermal history and microstructure comparison with experimental results using literature derived thermo-physical material properties.