Development of a 3D multi-scale PBF-LB/M temperature history FEM simulation model

Abstract Among various additive manufacturing methods, powder bed fusion-laser beam/metal (PBF-LB/M) stands out for its rapid prototyping and design flexibility. However, temperature-related defects often limit its material suitability, and capturing temperature evolution during fabrication remains challenging. This study presents a 3D multi-scale finite element (FEM)-based model to predict locally-resolved time-temperature profiles in PBF-LB/M. The model integrates a macroscopic part-scale simulation with a meso-scale simulation by transferring temperature field data between them. DIN EN 1.4404 stainless steel is used, incorporating experimentally measured material and process parameters. The part-scale model employs a lumped-layer approach to enhance simulation speed at the expense of accuracy, while the meso-scale model focuses on detailed laser scanning and powder-solid transitions, demanding higher computational resources. Despite differing accuracy levels, both models yield consistent results in low-temperature regions, particularly at the end of each thermal cycle. Overall, the proposed multi-scale model effectively predicts the thermal history of the PBF-LB/M process, achieving a practical compromise between accuracy and computational efficiency.