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A novel process for low-density alumina foams has been studied. Aqueous acidic sucrose solution containing aluminum nitrate when concentrated by heating formed a viscous resin. The resin mixed well with aqueous alumina slurry and the resulting powder-filled resin underwent foaming on heating in a Teflon mold. The green foams produced had very good handling strength. Binder removal and sintering of the green foam prepared at sucrose to alumina weight ratio in the range 0.69-1.03 produced alumina foam bodies with porosities 93.5%-96.7%. Microstructure of the foams depends on sucrose to alumina weight ratio such that a clear transition from reticulated structure to cellular foam structure took place at sucrose to alumina weight ratio below 0.89. Average pore size depends on sucrose to alumina weight ratio and was observed in the range 0.48-2.69 mm.

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Ceria stabilized zirconia powders with ceria concentration varying from 6 to 16 mol% were synthesized using spray drying technique. Powders were characterized for their particle size distribution and specific surface area. The dense sintered ceramics fabricated using these powders were characterized for their microstructure, crystallite size and phase composition. The flexural strength, fracture toughness and microhardness of sintered ceramics were measured. High fracture toughness and flexural strength were obtained for sintered bodies with 12 mol% of CeO 2. Flexural strength and fracture toughness were dependent on CeO 2 concentration, crystallite size and phase composition of sintered bodies. Correlation of data has indicated that the transformable tetragonal phase is the key factor in controlling the fracture toughness and strength of ceramics. It has been demonstrated that the synthesis method is effective to prepare nanocrystalline tetragonal ceria stabilized zirconia powders with improved mechanical properties. Ce-ZrO 2 with 20 wt% alumina was also prepared with flexural strength, 1200 MPa and fracture toughness, 9⋅ ⋅2 MPa√ √m.