Ceramics are non-organic, non-metallic materials, which show excellent resistance to high temperatures, abrasives and chemicals. They have comparatively low densities and are extremely hard, although some show poor shock resistance. A low density, permeable structure of cells and continuous ligaments offer a high surface area to volume ratio, and a high strength to weight ratio.
Ceramic foams can be produced using a range of ceramic materials, both oxide and non-oxide, and are being considered for many potential applications. These include hot gas filters, interpenetrating composites and biomedical applications as well as thermal insulation, kiln furniture and catalyst support. Generally, materials such as alumina, cordierite, mullite and zirconia are being used for foams, however, many other ceramics can be foamed, including non-oxides such as silicon carbide and aluminium nitride. The pore walls and struts are solid and fully dense, providing high strength and chemical resistance.
Ceramic foams have a wide range of potential applications in biomedicine, thermal insulation, filtration of molten metal alloys, adsorption of environmental pollutants, catalyst supports.