Hamed Sheikhbahaee, Ehsan Barati, Mohammad Erfanmanesh, Seyed Masoud Barekat,
Volume 9, Issue 2 (Journal OF Welding Science and Technology 2026)
Abstract
This study presents a coupled numerical–experimental analysis of the selective laser melting (SLM) process of AISI 316L stainless steel aimed at achieving minimum porosity (maximum density). A multiscale modeling approach integrates discrete element (DEM), finite volume (FVM), and finite element methods (FEM). First, additive manufacturing parameters were optimized to minimize porosity. Then, using the optimized parameters, DEM simulated powder spreading, followed by FVM for molten pool dynamics. Finally, the optimized parameters were applied in a macro-scale FEM simulation—using the National Institute of Standards and Technology (NIST) AM test artifact—to evaluate part distortion, thermal stress, and porosity. Results indicate the highest distortion occurs at the outer edges (0.9 mm), while the lowest is observed at the center of the top surface. Numerical studies also show that the thermal-stress distribution is complex due to alternating melting and solidification cycles, with maximum stress occurring between layers. The maximum thermal stress at the end of the additive manufacturing process is 750 MPa, and during the process it reaches 910 MPa. The experimental density after final finishing was measured at 99% (1% porosity), in complete agreement with the numerical results. The agreement among computer simulations, analytical predictions, and experimental data indicates this approach can be successfully used to investigate and optimize distortion, stress, and porosity during the SLM process.
