Characterization of cellular ceramics for high-temperature applications

Polymeric sponge replication technique is the most used process to obtain ceramic foams with a cellular structure for filtration applications. This technique is based on an impregnation of a polymeric sponge with ceramic slurry, removal by squeezing, followed by burning out polymer and high temperature sintering. Ceramic filters must present high permeability and strength. However, these parameters are influenced in different ways by the processing method and the consequent cellular structure. In this work the relationship between permeability and strength has been investigated for 10- and 40-ppi (pores per linear inch) Al2O3–ZrO2 filter materials. Characterization included the evaluation of the permeability and strength as well as the microstructural analyses of the fracture surface