cellular ceramic ware that is usually prepared from liquid foams and highly dispersed mineral powders, for example, Al2O3, MgO, and ZrO2. As the powder is wetted by the liquid foam, the solid particles become distributed in foam layers and the gas bubbles become surrounded by diphase envelopes. Upon drying, the liquid phase of the foamy mass evaporates and a solid foam is obtained, which can then be baked to impart strength.
The average density of the foamed ceramics depends on the porosity. For example, the density of alumina-based foamed ceramics with a porosity of 30 percent is 1,200 kg/m3, and with a porosity of 85 percent, 600 kg/m3. Foamed ceramics with low thermal conductivity and high thermal resistance are mainly used in thermal insulation.