A novel process for low-density alumina foams

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.