Time-resolved tomography (∼25 Hz) of AlSi10 + 0.5 wt% TiH2 precursor granules foaming at ∼923 K in a cylindrical BN crucible. (a) Tomogram of several granules at t = 7.695 s, with bubbles coloured for the central granule, and time evolution of the bubbles in this granule over five tomograms, each separated by only 39 ms. (b) Time evolution of the mean-equivalent bubble diameter over 156 ms corresponding to (a). (c) Series of six two-dimensional slices, each separated by 2.5 s, as extracted from the series recorded over 15.5 s during foaming, and showing the appearance and growth of gas bubbles and foam evolution. Small white dots correspond to TiH2 particles. (d) Two two-dimensional slices of one granule at t = 12.558 s and t = 12.597 s and the corresponding difference image showing changes in red.