Process monitoring and defect control for laser powder bed fusion

To address the critical challenges of process monitoring and defect control in laser powder bed fusion (LPBF), we develop an integrated framework combining multimodal process tomography with multiphysics simulation to monitor, understand, and control defect formation and evolution. A visible-light tomography system and a thermal tomography system are employed for layer-wise monitoring throughout the LPBF process. The visible-light system captures the evolution of powder-bed and layer-surface morphology, enabling the identification of geometric anomalies, while the thermal tomography system records the transient thermal history associated with laser-material interaction. The formation and propagation mechanisms of representative defects are systematically investigated. Based on the identified defect signatures and underlying physical mechanisms, targeted process optimization and active control strategies are developed to suppress defect initiation and growth. The proposed monitoring and control methodology is further validated using representative LPBF components, providing a systematic approach for enhancing process stability, defect controllability, and quality consistency in metal additive manufacturing.

Prof. Huiliang Wei is from Nanjing University of Science and Technology. His researches mainly focus on the process, structure, and material properties for additive manufacturing. His exploration approaches include mechanistic models, data driven models, and in situ monitoring of the printing processes. He is the recipient of the National Science Fund for Excellent Young Scholars and the Jiangsu Outstanding Youth Fund. He has hosted over 10 projects including the National Key R&D Program of China and the National Natural Science Foundation of China. He has published over 80 peer-reviewed papers in mainstream journals including Progress in Materials Science, Additive Manufacturing and Acta Materialia, with over 10000 citations. He has applied more than 20 Chinese invention patents and has delivered over 20 keynote and invited presentations at conferences. He serves as the Program Committee Chair of the International Conference on Research Frontiers in Additive Manufacturing (RAAM). He has been selected for Jiangsu's "Double Innovation" Talent Program and obtained the First Prize of Jiangsu Provincial Science and Technology Award.