||High temperature coatings
based on advanced ceramic materials are used in order to change the characteristics
of substrate surfaces, mainly of metals and ceramics. These coatings are
used under extreme temperature conditions, for example as high temperature
lubricating and release agents. They can protect substrates like metals,
nitrides or carbon-containing workpieces against aggressive melts or gases
and by this prevent their chemical conversion. Besides, coatings are used
as marking material for the high temperature area, too.
Apart from the well-known
coating processes such as PVD, CVD and plasma suspensions are used, which
can be applied like wall paints. They usually contain ZrO2,
Y2O3, SiC, Si3N4 or BN, which
are suspended with bonding agents and additives blended in a carrier liquid
(water or organic solvents).