On Modeling the Thermal Behavior of Single and Quad Laser Melting of Powdered Nickel Alloy

Abstract

Selective laser melting is an additive manufacturing process that uses high laser power beam to melt the powders and fuse together to form three-dimensional parts from CAD model. Inconel 625 is a nickel-based alloy that is widely used in aerospace, chemical, nuclear reactors, and marine applications. As these applications need high service temperatures and corrosion resistance properties, the quality of the parts fabricated should be taken into consideration while fabrication of parts. The formation of the temperature gradient is critical as it affects the stability and dimension of a molten pool, which in turn affects the surface finish and densification of the parts. However, for producing a quality part from selective laser melting, understanding the thermal behavior under laser melting is necessary, when subjected to different process settings. In this paper, using a thermal analysis was used to study the melting by selective laser melting. The different process settings chosen for analysis include laser power and scan speed using constant energy density model. The Gaussian model has been adopted for symmetrical distribution of laser irradiance across the beam. The simulation for temperature analysis was carried out using commercial FEM software for single and quad laser configurations. The temperature profiles were observed at several nodes by varying the process parameter and the temperature distribution during the fabrication was predicted.