4D X-Ray Tomography of Dendrite Evolution

Many metallic alloys solidify via the formation of dendrites, tree-like structures composed of primary trunks and higher order branches. Using 4D synchrotron X-Ray tomography at theAdvanced Photon Source at Argonne National Lab, we are able to capture the evolution of dendritic microstructures during the solidification of Al-Zn alloys. By analyzing the data obtained, we can obtain fundamental information about the dendrite evolution, including:

  • Dendrite tip radii and curvatures
  • Tipvelocities
  • Solid and liquid volume fractions
  • Interfacial area evolution
  • Secondary branch spacings
  • Crystallographic growth directions
  • Morphological symmetries

Importantly, we are able to identify how the solidification process and resulting dendrite structures are influenced by cooling rate and composition.

Analysis of the data from APS is facilitated by our group’s expertise in image analysis and high performance computing. Reconstructions of tomographic data are performed using Northwestern’s high performance computing cluster,  Quest. Segmentation of the reconstructed data is performed using convolutional neural networks for semantic segmentation.