good electrical insulation
good thermal conductivity/insulation
High temperature lubrication is possible by using hexagonal boron nitride.
Just like carbon exists in the form of hard diamond and soft graphite, boron nitride can exist in the hard cubic structure and the soft, 'lubricating' hexagonal crystal structure.
Ceramics are very hard, have a high mechanical strength, an excellent wear-resistance and low friction. All this is useful for repeated, accurate positioning (e.g. zero point tooling systems).
Ceramic materials offer good wear-resistance and chemical resistance. Due to the high machining accuracy, we are able to produce 100% leak-proof ball valves.
Ceramic materials are used as linear guides in, among others, vacuum and E-Beam because of their high stiffness, their good tribological properties and the fact that they are not magnetic.