The results of the processed computed tomography data are shown
in Fig. 7 for the Cu-foam with a mean pore size of 0.5 mm used in the
test-column experiments. The tomograms were taken from the center
of the foam specimen. The homogeneous distribution of the surface
layer is clearly evident in Fig. 7b and c highlighting the open-cell structure
of the foam and interconnectivity of the pores. For reasons of clarity
the surface layer is illustrated separately in Fig. 7d and e. A quantification
of the surface layer in terms of volume percentage was estimated
to 4–5% of the total volume of the foam (including pores) or 17% of
the total volume of the solid phases of the foam (e.g. copper and oxides).