A New Method for Preparation of Cellular Ceramics by Gelcasting Approach

This paper presents the results of a novel-processing route for fabricating highly cellular ceramics. The method is based on the generation of foam in two continuously stages: one, is the foaming of ceramic suspension by use foaming agent prior to the polymerization and other, is the evaporation of light organic solvent such as acetone, methanol and ethanol during polymerization because of exothermic reaction of gelation. The resulting ceramic foams consisted of a highly interconnected network of cells with densities as low as 0.2 g/cm3. The distribution of cell size was dependent both on the density of the specimen produced and on the time for polymerization onset. The size ranged from approximately 50 to 1000 μm. Enlargement of cell size to achieve materials of high permeability was possible through expansion of the foam via pressure reduction before polymerization