Effect of Heat Input Parameters on Temperature Field in Inconel 718 Alloy during Selective Laser Melting

This article combines the finite element simulation and experimental verification to study the effect of laser power and scanning velocity on the temperature distribution, and the size of molten pool during selective laser melting, through simulating the laser reciprocating scanning and transformation between powder material and solidified alloy during SLM. A temperature dependent thermal-mechanical properties of materials is considered, which includes the properties conversion between powder layer and solidified alloy. By presenting a comprehensive parameter of laser heat input-laser line energy density, the effect of line energy density on molten pool in Inconel 718 alloy is summarized, and the size of molten pool can be predicted. The results indicate that temperature field isotherm distribution presents as ellipsoid with the effect of moving laser, and in addition, ellipsoid shifts to solidified alloy layer. Within the scope of the study parameters, the laser line energy density and the size of molten pool during the deformation exhibit linear growth relationship. Furthermore, several Inconel 718 alloy specimens in different laser input conditions were produced using SLM equipments, in order to verify the simulated molten pool size. The result shows that experimental measurements are in good agreement with the model predictions.