Ceramic is an inorganic, non-metallic material. It is shaped by adding water, dried at room temperature and hardened in a firing process. Ceramic materials can be of natural origin or manufactured synthetically. With the help of high-purity synthetic ceramic materials, the material properties can be set individually depending on the component or application.
Typical ceramic raw materials are on the one hand silicate raw materials, which are mostly of natural origin. This includes clay minerals and their mixtures, kaolins or non-plastic raw materials. Another class of ceramics are the oxidic raw materials, which are used in technical ceramics in particular. Some of them are produced synthetically and typical representatives are aluminum oxide, zirconium oxide, beryllium oxide and titanium oxide. There are also non-oxidic ceramic raw materials that are also used in technical ceramics and are manufactured entirely synthetically. These include in particular silicon carbide, boron nitride and boron carbide.
The most important properties of materials from technical ceramics are:
- Heat resistance up to well over 1000 °C
- Electrical insulation capacity (depending on type)
- High dielectric constant
- Abrasion and wear resistance
- Great hardness and dimensional stability
- Corrosion resistance
- High mechanical strength
- Low thermal expansion
Ceramic materials are now often used instead of metals. For example, they are used in medicine to replace bones and teeth. Another important area of application are the so-called hot applications such as furnace construction, heating or fuel elements with up to 2500 °C. Ceramic raw materials are also often used in electrical components such as ceramic capacitors or as insulator material. Due to the many positive properties of ceramic materials, there is a wide range of different applications. The only disadvantage compared to metal is that ceramic materials brittle more quickly due to its low fracture toughness.
Due to their high heat resistance, these raw materials are also suitable for marking solutions such as ceramic inks. In particular in very rough production conditions, such as press hardening in the automotive industry (temperatures above 900 °C), these can enable the complete identification of components.