Three-dimensional analysis of particle coarsening in high volume fraction solid–liquid mixtures

The three-dimensional microstructure of 78 and 52 vol.% Sn-rich particles coarsened within a liquid Pb–Sn matrix were determined by the reconstruction of serial sections. The three-dimensional particle size distribution (PSD) and the particle–particle contact distributions were determined. The three-dimensional PSDs do not match those predicted by particle coarsening theory, but there is reasonable agreement with the grain size distributions predicted by a grain growth simulation. In addition, when the particle–particle contact distribution is normalized to the average number of particle contacts, the distribution is statistically invariant with volume fraction. At 52 vol.% it is found that the number of contacts is proportional to the square of the average particle size, but this is not true for 78 vol.%. This is attributed to the increased shape distortions of the particles that are present in the higher volume fraction samples.