Integrating In Situ x-Ray Imaging, Energy Dispersive Spectroscopy, and Calculated Phase Diagram Analysis of Solute Segregation During Solidification of an Al-Ag Alloy

High-energy, microfocus x-ray imaging, or x-radiography, is a useful tool for in situ analysis and monitoring of materials processing. Large fields-of-view, spatial and temporal resolutions sufficient for mesoscopic imaging, and high-energy x-rays capable of probing metallic alloy samples make the technique attractive for in situ solidification studies in the laboratory. Here, we demonstrate the usefulness of high-energy, microfocus x-radiography in the laboratory, particularly when paired with complementary techniques. Multimodal, multiscale characterization was performed, including x-radiographic analysis of solidifying Al-Ag and compositional analysis of the same sample after solidification with scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). The dynamics observed through x-radiography during solidification are compared to the compositional results obtained by EDS. The fraction solid measured in radiographs is also used in combination with a calculation of phase diagrams (CalPhaD) Scheil solidification simulation to reconstruct a spatiotemporal microsegregation map. The multimodal, multiscale characterization techniques presented here illustrate a promising pathway toward improved analyses and monitoring of materials processing within a laboratory setting.