| Abstract Scope |
Laser Powder Bed Fusion (LPBF) enables near-net-shape fabrication with refined microstructures and enhanced mechanical properties. However, steep thermal gradients can induce residual stresses, distortion, and warpage. This study introduces in-situ Dynamic Laser Area Heating (DLAH) during low-power Diode Point Melting (DPM) of SS316L to improve thermal control. The system combines a defocused 140 W, 915 nm diode laser with a 35 W, 450 nm DPM laser. In-situ DLAH reduces cooling rates, promoting 20.5% grain coarsening and the formation of ferrite alongside γ-austenite. Surface roughness improves from 14.94 μm to 8.14 μm, while common LPBF defects such as balling, lack of fusion, and spatter are suppressed. The DLAH approach provides enhanced thermal management, enabling controlled microstructural evolution and reduced defect formation in SS316L components. |