Growth of β intermetallic in an Al-Cu-Si alloy during directional solidification via machine learned 4D quantification

Fe contamination is a serious composition barrier for Al recycling. In Fe-containing Al-Si-Cu alloy, a brittle and plate-shaped beta phase forms, degrading the mechanical properties. Here, 4D (3D plus time) synchrotron X-ray tomography was used to observe the directional solidification of Fe-containing Al-Si-Cu alloy. The quantification of the coupled growth of the primary and beta phase via machine learning and particle tracking, demonstrates that the final size of the beta intermetallics were strongly influenced by the solute segregation and space available for growth whereas the orientation was controlled by the temperature gradient direction. The work can be used to validate predictive models. (C) 2019 Published by Elsevier Ltd on behalf of Acta Materialia Inc. All rights reserved.