Temperature and Fluid Velocity Field Estimation in Melt-Pool Using Multiphysics-Based Numerical Simulation for Multi-Track Selective Laser Melting Process

The selective laser melting (SLM) process involves various physics-based phenomena with many process variables, so predictions of its characteristics and part quality are tedious. Researchers are developing numerous numerical and analytical formulation models to simulate the SLM process realistically and efficiently to compute various functions and part characteristics. The present work developed a fully developed Multiphysics 3D Finite Element numerical model for the multi-track SLM process by incorporating transient heat transfer, fluid flow, Marangoni effect, and material phase transformation. The porosity and deformation behavior of the powder bed is also considered to replicate the possible contraction in the powder bed. The temperature-dependent material properties of Ti6Al4V alloy were used to run the simulation. The temperature and velocity distribution obtained after incorporating fluid behavior and Marangoni convection gives the final melt-pool dimensions by extrapolating the temperature isotherms. Melt-pool dimensions increase with the subsequent tracks due to higher temperature regions in consecutive tracks, which further stabilizes once it attains steady-state temperature. The model can be further improved to study the part distortion and residual stresses in the SLM process.