Stochastic modelling of removability of NaCl in sintering and dissolution process to produce Al foams

The sintering and dissolution process (SDP) is a novel method for manufacturing Al foams. One concern of the process is the presence of residual NaCl in the as manufactured Al foams under certain circumstances, which may have undesirable effects on the properties of the foams. This paper develops a stochastic model to predict the fraction of entrapped NaCl based on the assumptions that the particles of the Al and NaCl powders used in SDP are spherical and monosized and that they are distributed randomly in the preform. The model predicts that the fraction of entrapped NaCl in the foam decreases with increasing volume fraction of NaCl in the preform and with decreasing NaCl-to-Al particle size ratio. The model predictions are in general agreements with the preliminary experimental measurements. The model provides a basis for the selection of Al and NaCl powders in order to minimise the entrapped NaCl in the foam.