Technical and industrial ceramics - the versatile material with a future
Engineering ceramics are also called technical ceramics, industrial ceramics, industrial ceramics or high-performance ceramics. In principle, it consists of the same basic materials as ceramics, which are produced for sanitary or decorative purposes. The different properties of the materials result from the different manufacturing processes.
Manufacture of engineering ceramics
The starting materials of these ceramic materials are a crystalline powder, an organic binder and a liquid. The resulting mass obtains its desired material properties by sintering. The grain size of the starting material, the firing temperature, the firing atmosphere used and the firing process largely determine these properties. The shape of the ceramic components also influences the material properties. Notches and corners in the component thus increase its tendency to brittle fracture. On the other hand, infinitely large and arbitrarily shaped components are not feasible. The problem lies in the fact that a homogeneous, uniform structure must be ensured with heat input only possible from outside. The limits for the size are approx. 30 cm diameter and 3 m length. At present there are about 40 manufacturers all over the world capable of doing this.
Properties of engineering ceramics
The ceramic materials used in technology can have very different properties. There are materials with high or low thermal conductivity as well as electrical insulators, semiconductors and piezoelectric materials. Some ceramic components can withstand temperatures of up to 1,000 °C. The materials produced in this way are often very hard, but also fragile, and have a high resistance to wear and abrasion. They have low thermal expansion and are corrosion resistant. For medical applications, the high biocompatibility of the ceramic is decisive. Despite all their positive properties, ceramic materials also have a major disadvantage. They are brittle and therefore break much faster than metals. The development of ceramic fibre composites has brought one way out, at least in part.
Applications of ceramic components
With the increasing development of materials, engineering ceramics are conquering more and more areas of application. Many ceramic components can be found in electrical engineering. There they are mainly used as insulators. However, there are also applications as semiconductors as well as hot and cold conductors. Another type of insulation is offered by ceramic materials in automotive and heating technology. The heat resistance of the materials is exploited there. They can be found, for example, in car spark plugs, engine parts or turbine blades. Wear resistance and good biocompatibility have made engineering ceramics omnipresent in medical technology. It is used there, for example, as a material for bone or dental prostheses. Everyone knows piezoelectric ceramics as an oscillating quartz in quartz watches. Another large field of application for this ceramic is fuel injection pumps in vehicles. In addition, they are often used, for example, to generate ultrasound.