Silicon carbide consists of the chemical elements silicon (like in sand) and carbon, and is very hard. Due to the good chemical resistance, silicon carbide can be applied very well under extreme conditions.
Due to its crystal structure, silicon nitride is one of the toughest ceramic materials. Furthermore it has a very good thermoshock resistance and good tribological properties.
Aluminum oxide (or alumina) is the most widely applied type of ceramics, often used as electrical insulator and for wear-resistant applications. The material is available in several grades.
Aluminum nitride combines a high thermal conductivity with a very low electrical conductivity. This heat conductor and electrical insulator is suitable for many electrical and electronical applications.
Zirconium oxide (or zirconia) is a type of ceramic with the highest fracture toughness. Due to the average crystal size of 0.5 microns, this material is very suitable for making, for example, ceramic knives.
In contrast to other ceramics, boron nitride with the hexagonal crystal structure is soft and easy to machine. Special property: BN is not wetted by liquid metals such as aluminum.
Boron carbide is an extremely hard type of ceramic with a low weight. This makes the material extremely useful for nozzles and ballistic applications.
Ruby is monocrystalline aluminum oxide where some of the aluminum atoms have been replaced by chromium atoms in a controlled way. This replacement is the cause of the typical ruby (red) colour.
Sapphire is monocrystalline aluminum oxide with controlled traces of other elements. As a transparent material, sapphire is suitable for optical applications.
Macor is the trade name of a machineable glass-ceramic, often used for electrical applications and at high temperatures.
ZTA and ATZ
Combining aluminum oxide with zirconium oxide results in a composite material with, among other things, improved fracture toughness.
In order to make ceramics tougher and more thermoshock resistant, embedding of ceramic fibres in a ceramic matrix is a solution.