Fabrication of alumina-based ceramic foams utilizing superplasticity

Model ceramic foams were fabricated by expanding once-sintered dense shells utilizing the superplastic deformation of alumina dispersed with 3 mol% yttria-stabilized zirconia (3YSZ) or magnesia. The grain growth of alumina was suppressed by adding 3YSZ and the resultant grain size and amount of dispersion were closely related to the total porosity. Total porosity of the ceramic foam depended on the grain size and their distributions irrespective of the size of starting powders.