Understanding the Rapid Solidification of Al-4.3Cu and Al-17Cu Using X-Ray Tomography

摘要

X-ray tomography using synchrotron radiation with 1mu n. beam resolution at the European Synchrotron Radiation Facility was used to generate three-dimensional (3-D) images for rapidly solidified 660 mu m A14.3 wt pet Cu and 500 mu m A117 wt pet Cu atomized droplets. Based on the observation of microstructural features in the 3-D images, physical phenomena of rapid solidification such as nucleation and initial growth, recalescence, and porosity were apparent and are reported. A single nucleation site was observed and the coordinates of this single nucleation site were evaluated. The volume fraction of the initial growth regime and recalescence during solidification was successfully quantified. It was also possible to semiquantitatively explain the porosity distribution within the droplets. These observations will be used to present a description of the sequence of the solidification events in these droplets.