X-ray imaging of Al-7at.%Cu during melting and solidification

Abstract

In situ characterization techniques are now affording direct interrogation of opaque materials during synthesis and processing. In this work, synchrotron X-ray radiography and tomography were performed at Argonne National Laboratory’s Advanced Photon Source to monitor metallic alloys during melting and solidification. X-ray radiographs of microstructure evolution in Al-7at.%Cu during continuous heating and cooling were obtained; the influence of cooling rate on microstructure evolution was also explored. X-ray tomography results of solidification progression in the mushy zone are also presented. These results demonstrate that synchrotron X-ray radiography and tomography can nondestructively and sequentially reveal metallic alloy melting and solidification over the micron length scale in 2D and 3D. In situ characterization will permit advances in solidification theory and allow for the development of predictive solidification and microstructure evolution models. Feedback from real-time imaging will ultimately enable in-process parameter adjustments to control microstructure evolution.