Ceramic foam is a tough foam

Foam

-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...

 made from ceramic

Ceramic

A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous...

s. Manufacturing techniques include impregnating open-cell polymer foams internally with ceramic slurry

Slurry

A slurry is, in general, a thick suspension of solids in a liquid.-Examples of slurries:Examples of slurries include:* Lahars* A mixture of water and cement to form concrete* A mixture of water, gelling agent, and oxidizers used as an explosive...

 and then firing in a kiln

Kiln

A kiln is a thermally insulated chamber, or oven, in which a controlled temperature regime is produced. Uses include the hardening, burning or drying of materials...

, leaving only ceramic material. The foams may consist of several ceramic materials such as aluminum oxide, a common high-temperature ceramic, and gets insulating powers from the many tiny air-filled voids within the material.

The foam can be used not only for thermal insulation, but for a variety of other applications such as acoustic insulation, absorption of environmental pollutants, filtration of molten metal alloys, and as substrate for catalysts requiring large internal surface area.

It has been used as stiff lightweight structural material, specifically for support of reflecting telescope

Reflecting telescope

A reflecting telescope is an optical telescope which uses a single or combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century as an alternative to the refracting telescope which, at that time, was a design that suffered from...

mirrors.