A study of micropyretic synthesis of slip cast colloidal SIO2-Al-C exothermic system

Abstract

The feasibility of micropyretic synthesis in Al2O3-SiC composites through the slip casting route has been investigated. The slip rheology and combustion kinetics in a colloidal silica suspended SiO2-Al-C system has been studied as an example of such processing. Colloidal silica functioned as a binder and also constitured part of the combustion source in the green compact. The degree of conversion and porosity level of the micropyretically synthesized product have been found to depend on the rheology of the suspensions including the solid concentration, particle size and pH value of the suspensions. The major phases, -Al2O3 and -SiC, in the composite produced with this new method were homogeneously distributed within each other. A modified analytical model for the slip cast micropyretic system has been developed considering slip parameters and the thermophysical and chemical properties of the reactants. Results obtained from the model are noted to be in close agreement with the experimental values.