Invited Speaker

Abstract: While laser powder bed fusion (LPBF) has revolutionized the processing technologies of metal components, the persistent challenge of porosity defects, including cracks, lack-of-fusion, and gas pores, continues to impose critical limitations on the structural integrity and mechanical performance of printed alloys. Here, we propose a novel liquid-induced healing (LIH) post-process that employs an intergranular liquid via localized partial remelting at grain boundaries, enabling capillary-driven defect backfilling while establishing interconnected channels for gas evacuation. Employing LPBF-fabricated IN738LC and IN718 superalloys as model systems, we comprehensively evaluate the LIH process’s effectiveness in defect elimination and its influence on key mechanical properties, including tensile strength, fatigue resistance, and creep performance. Our findings demonstrate that the LIH treatment achieves near-complete porosity eradication and significantly enhances mechanical properties through a cost-effective methodology, thereby alleviating current limitations in metal additive manufacturing for engineering applications.

Biography: Dr. Xiaogang Hu serves as an Associate Professor at the School of Advanced Manufacturing, Sun Yat-sen University. His research focuses on advancing fundamental knowledge in additive manufacturing applications for high-performance metallic systems and metal-matrix composites. Professor Hu has pioneered several innovative technologies, including A liquid-induced healing post-treatment for cost-effective remediation of structural defects (e.g., microcracks, porosity, shrinkage cavities, and fatigue/creep damage), high-throughput evaluation of alloy creep behavior, and direct-write deposition for aluminum matrix composites. As principal investigator, he has secured and led over ten competitive research projects across national, provincial, and municipal funding tiers. His work bridges fundamental materials science with practical engineering applications in advanced manufacturing.