Sensitivity analysis of material and process parameters in finite element modeling of selective laser melting of Inconel 625

A prediction of the 2-D temperature profile and melt pool geometry for selective laser melting (SLM) of Inconel 625 metal powder with a numerically based approach for solving the heat conduction-diffusion equation was established in this paper. The finite element method is utilized to calculate two-dimensional (2-D) temperature profiles along the scanning (x-direction) and hatch direction (y-direction) for a moving laser heat source during SLM. The effects of varying laser power, scanning speed, and the powder material's density are analyzed. A sensitivity analysis has been conducted to investigate the influence of material properties and process parameters on the predicted temperature profile along the center of the laser beam path. It was found that the packing density (or porosity) significantly affects the temperature profile. The powder reflectivity has the greatest effect on the predicted peak temperature and melts pool geometry, followed by laser power and scanning speed. These results provide a detailed insight into the SLM process, since most of the predicted variables are very difficult to be measured experimentally.