Microstructure and properties characterization of a new ceramic filter — CEFILPB

Abstract

This work reports on the microstructure and properties obtained in new types of alumina-based filters when employing two different bonding agents, sodium silicate and monoaluminum phosphate, for their fabrication. The properties measured in this porous media, intended for liquid metal filtration, were: porosity, specific permeability, metallostatic prime head, pore and window sizes, thermal shock resistance and compression strength. It was found that thermal shock resistance and compression strength can be controlled independently from each other by choosing an appropriate agglomerant and sintering temperature. Thermal shock resistance is mainly influenced by the coefficient of volumetric thermal expansion of the resulting phases, while compression strength is strongly affected by the grain size in the final ceramic microstructure. Porosity and pore and window size distributions are the structural parameters that determine the fluidynamic characteristics of the filter. Ceramic consolidation during sintering should be considered to obtain specific values of these parameters.