Ceramic coatings play a dominating role in a large number of applications. They can perform functional tasks, such as piezo-electrical layers, controllable dielectrics, coatings for the photovoltaic energy conversion or electrolyte-layers in high-temperature fuel cells, which are only part of the whole range of applications possible. Moreover, ceramic coatings very often serve to protect load-bearing components made of other materials, mainly metals. In such applications, they are used to increase hardness, scratch resistance or to improve tribological properties in general.

The huge number of applications of ceramic coatings requires a high number of adapted process technologies for the application of the coatings onto the different substrates. These processes include the different Physical Vapour Deposition (PVD) and Chemical Vapour Deposition (CVD) techniques, sol-gel coatings, electrophoretic deposition or immersion techniques as well as thermal spray processes. Depending on material and coating type, the required properties, coatings thickness etc. a suitable process has to be selected, which has to be adapted if necessary.

This shows the very large band width covered by the field of ceramic coatings. However, the focus here is intended to be narrowed down to some examples of coatings and coatings systems that are relevant for many technical light-weight systems, in particular for high-temperature and very-high-temperature applications.