Investigation on the kinetics of infiltration of liquid aluminium into an alumina fibrous preform

The infiltration kinetics of liquid metal into a fibrous preform was analyz ed theoretically on the basis of Darcy's law and the assumptions that the p orous preform can be treated as "bundles of capillaries" and that the liqui d flow penetrating the preform is laminar. Experiments in infiltration kine tics were carried out with respect to an Al-1.5 Mg aluminium alloy/alumina short fiber preform system. It was revealed that an incubation time is requ ired to activate infiltration, that there is a parabolic dependence of the infiltrated depth on the infiltration time for an infiltration process unde r constant external pressure, and that the infiltration rate can be well pr edicted by the equation derived by the theoretical model proposed in the pr esent paper. Both the incubation time and the infiltration rate are influen ced significantly by the applied pressure. (C) 1999 Elsevier Science S.A. A ll rights reserved.