Computational Analysis of Selective Laser Sintering of Inconel 625

A two-dimensional multi-physics finite element model is developed to simulate the Selective Laser Sintering (SLS) process using Inconel 625 powders. The validity of the developed model is first assessed by comparing its results with experimental data. Various factors such as phase transition, recoil pressure, surface tension, and the Marangoni force are considered. The study’s findings underscore that the morphology and thermal-fluid dynamics of the molten pool in the SLS process are predominantly shaped by the influence of the Marangoni force and recoil pressure acting on its surface. The recoil pressure at the front of the laser spot rises exponentially with temperature, making the liquid metal move downward, and creating a depression at the pool’s head. It also causes particles to splash from the pool’s rear edge. The study explores the influence of the backward Marangoni force, where high-temperature liquid flows from the front to the rear of the molten pool, creating a vortex and moving the pool in the rear. Process parameters like laser intensity, scan speed, and spot size were analyzed. The findings indicate that higher laser power lower scanning speed and laser beam spot size lead to increased width and depth of the molten pool.