The Structural Dynamics Beamline at High Energy Photon Source: Probing the Dynamics of Laser Additive Manufacturing in High-Density Alloys

The formation and evolution of defects and microstructures during the additive manufacturing of metallic materials are closely related to melt pool dynamics under rapid, non-equilibrium conditions. Synchrotron radiation provides a unique tool for the in-situ characterization of metallic additive manufacturing (AM), enabling the visualization of the “black box” phenomena hidden inside the process. However, the application of current synchrotron radiation techniques is limited by two major bottlenecks: first, the difficulty in achieving high spatiotemporal-resolution imaging for high-density metallic material systems; second, the lack of ultra-fast X-ray diffraction capabilities with high temporal resolution. To tackle these challenges, the Structural Dynamics Beamline (SDB) at the High Energy Photon Source (HEPS) prodeces high-energy, high-brilliance, narrow-bandwidth pink beams via optimized insertion devices and optical designs. By integrating the beamline with custom in-situ metallic AM instrumentation, we have established high-energy, high-temporal-resolution diffraction and imaging characterization approaches have been established, enabling ultrafast dual imaging and diffraction (DIAD). This paper systematically describes the design and methodological development of the SDB, focusing on the application of multimodal measurement techniques for investigating dynamic mechanisms of the melt pool. The results clearly demonstrate the significant potential of this platform for in-situ monitoring of dynamic, irreversible processes during the additive manufacturing of high-density systems.