Ceramics

Ceramics is an applied science dealing with the preparation and application of a great number of organic chemicals. Until recently, ceramic materials were primarily silicate-bearing compounds. Now they include oxides, graphite, carbides, borides, silicides, nitrides, and systems compounded of these groups. Typical ceramic products are pottery, porcelain, enamels, refractories, glass, insulators, cement, bricks and building materials, and abrasives. Clay is still the basis of most commercial ceramic products, despite recent developments of new types of ceramic materials.

Ceramic products are usually man-made, although a number of ceramic products exist in a natural state, e.g. diamond, graphite, mica and marble. Ceramic products can be classified by the method of preparation into two groups: sintered and fused.

Silica, SiO2, is the main ingredient of all ceramic products. Its most common form is quartz. Kaolin or clay minerals are compound of silica and other metal oxides, particularly aluminium and magnesium, and are used in pottery manufacture. Mica minerals also consist of complex silicates. Mica is used as an insulator in electrical and electronic equipment.

An extensive technology is now developing around newer ceramics. Oxides have great potential because of their resistance to high temperatures and their electrical (insulation) properties. Graphite, because of its high melting point and high temperature strength, is finding wide-spread use in rocket building.

Ferrites (mixed oxides of iron and other metals) have magnetic properties which are of interest for computer components. Titanates, sapphire, rube and garnets are findig application in advanced communication equipment and energy and power-conversion equipment.

Cermets (combination of metals and ceramics) are becoming important ceramic systems.