In situ Characterization of Laser Powder Bed Fusion Using High-Speed Synchrotron X-ray Imaging Technique

Additive manufacturing (AM, a.k.a. 3D printing) refers to a suite of transformative technologies that build three-dimensional objects by adding materials layer by layer based on digital design. Compared with conventional manufacturing techniques, AM exhibits many unique advantages, including short supply chain, on-site and on-demand manufacturing of spare units and tools, short design-to-market, less consumption of energy, and less generation of material waste. More importantly, AM almost eliminates tooling constraints, giving us the much-needed freedom to design and build parts with complex geometries and improved performance. Nowadays, there are tens of different AM technologies, which we can categorize into seven families: powder bed fusion, direct energy deposition, binder jetting, material jetting, sheet lamination, vat polymerization, material extrusion, and hybrid. Among all, laser powder bed fusion (LPBF) is the most extensively used technique for 3D printing metals, and has found many applications in the fields of biomedical, aerospace, automobile, and defense.