Cordierite: is a refractory ceramic with low heat conduction and expansion. It is used when high-temperature insulation is required when there are frequent and large temperature fluctuations (heat shields, insulation of kilns, catalytic converters).

Oxide ceramics: Oxide ceramics are harder, more wear-resistant and more heat-resistant, but also more brittle than hard metals. They are highly corrosion-resistant even at high temperatures in the application range up to> 1000 ° C. Their low toughness and the low tolerance to rapid temperature changes have a disadvantage. A typical representative of oxide ceramics is aluminum oxide (Al2O3) with approx. 85% coverage of all applications.

Compared to oxide ceramics, nitrides, carbides or borides are characterized by mixed bonds with predominantly covalent and only minor proportions of ionic bonds. This means, due to the strong binding energies, high chemical and thermal stability, hardness and strength, but also low ductility and very high brittleness. Typical representatives here are silicon nitride, boron carbide, boron nitride, silicon carbide, aluminum nitride.