Three-dimensional characterization of the permeability of W–Cu composites using a new “TriBeam” technique

Research output: Contribution to journalArticlepeer-review


  • Mclean P. Echlin
  • Michael Wang
  • Paul J. Mignone
  • Daniel P. Riley
  • George V. Franks
  • Tresa M. Pollock

Colleges, School and Institutes


Large three-dimensional microstructural datasets have been gathered for two W–Cu composites of 10 and 15 wt.% Cu using the TriBeam system via in situ femtosecond laser sectioning in a scanning electron microscope. Laser ablation was performed on W–Cu samples along a 90 ° edge, milling parallel with the imaging surface. Secondary electron images for 1000 two-dimensional slices were segmented into binary images representing Cu and W components using EM/MPM (expectation–maximization/maximization of the posterior marginals) image-processing algorithms. A statistically random volume sampling approach has been employed to evaluate the microstructural and property volume element sizes necessary for the assessment of volume fraction, surface-area to volume ratio and permeability, respectively. This approach also characterizes the mean values and variability in microstructure and properties for volume elements ranging from 10 μm to 160 μm on edge. The converged values of the volume fractions of Cu closely match experimental values measured by the Archimedes technique.


Original languageEnglish
Pages (from-to)307-315
Number of pages9
JournalActa Materialia
Early online date22 Nov 2013
Publication statusPublished - Feb 2014


  • Tungsten–copper, Microstructural volume element, Property volume element, Representative volume element, Femtosecond laser tomography