Drainage in standing liquid metal foams: modelling and experimental observations

A simple numerical model is presented for simulation of the redistribution of liquid within a metallic foam during processing. The main driving forces involved are gravitational and capillarity effects. The cell geometry is taken as a pentagonal dodecahedron. The model allows prediction of the development of vertical density gradients as a function of cell size, initial porosity level, specimen height and thermo-physical properties. Comparisons are made between model predictions and experimental data relating to particulate-containing aluminium foams. These suggest that the main factors involved have been correctly incorporated into the model. Deductions are made concerning the implications of the results for optimisation of melt processing operations involving metallic foams.