Probing Ultrafast Dynamics in Laser Powder Bed Fusion Using High-Speed X-Ray Imaging: A Review of Research at the Advanced Photon Source

Additive manufacturing (AM) is a transformative technology that opens up many exciting opportunities. In metal AM processes, high-power heat sources are often used to locally fuse the metal feedstock to the previous layer. Extreme thermal conditions are involved and unique microstructures are developed in AM-processed materials. At the Advanced Photon Source, we applied high-speed x-ray imaging to probe the ultrafast dynamics of the vapor depression, melt flow and particle spattering, among other transient phenomena. Demonstrated by the scientific cases reviewed and cited here, high-speed x-ray imaging is a unique tool for metal AM research. It provides invaluable information that can help address the critical issues in AM associated with structural defects, high-fidelity models, build reliability and repeatability.