A technical ceramic is any ceramic compound developed to exhibit very specific characteristics to suit the unique needs of demanding applications. These include ceramic materials used in aeronautical, biomedical, and high-performance mechanical applications. Commonly encountered special characteristics include high levels of resistance to extreme temperatures and abrasion achieved by the addition of oxides and nonoxides such as alumina, ceria, and boride to conventional ceramic bases. In some cases, ceramic particulate and fiber-reinforced composites may also be used as technical ceramic compounds. Technical ceramic materials may be used to produce solid, one-piece castings, or may be applied to existing products as a high-performance coating.
Ceramics are one of the oldest man-made materials, with pottery objects dating back 27,000 years, giving some idea of the longevity of man's association with the material. In essence, ceramics are inorganic compounds of a crystalline or amorphous nature formed by exposure of raw materials to extreme heat followed by a natural, unforced cooling process. Although ceramics are found in a myriad of forms ranging from coffee cups to floor tiles, there are four widely accepted classifications of the material. These are structural ceramics such as pipes and tiles, refractory ceramics including furnace linings, whiteware such as crockery, and high-performance technical ceramics.
Of these groups, technical ceramics are the most sophisticated and used in the most demanding applications. The applications include space shuttle re-entry shield tiles, ballistic missile nose cones, and the coatings of turbine blades in jet engines. High-performance bearings, gas burners, and some bullet-proof vest inserts are also made from technical ceramics. Biomedical implants such as dental bridges are another common destination for these high-tech ceramics. These highly taxing applications require the ceramic compounds to possess extreme levels of mechanical integrity while remaining sterile and structurally stable.
Most technical ceramic compounds begin as conventional ceramic bases and are imbued with their eventual specialist characteristics via the addition of other elements. These include oxides such as alumina, zirconia, and ceria, or nonoxides including carbide, boride, and nitride. Technical ceramic materials may also be created by forming composites of conventional ceramics with particulate or fiber reinforcement. These additives and composite elements effectively create specific groups of crystalline ceramic structures in the base material which lend the end products their outstanding performance. Items requiring the unique characteristics of technical ceramics may be made as solid castings or coated with a layer of ceramic material.
