Ceramic Coatings:
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The oxides of different metals are commonly called Ceramics. The most commonly used ceramic coatings are Aluminium Oxide (Al2O3), Chromium Oxide (Cr2O3), Titanium Oxide (TiO2), and Zirconium Oxide (ZrO2). They differ concerning temperature resistance, electric conductivity, acids and alkalis resistance
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Depicted is a hollow shaft coated with chromium oxide ceramic because of wear resistance. Above you see an uncoated shaft.
Other applications for ceramic coatings are:
Chromium or Titanium Oxide for heat emission, e.g. in the aerospace industry
Zirkonium or Aluminium Oxide for heat insulation, e.g. in rocket- and jet-engines
Zirkonium Oxide as thermal insulation layer in pistons of diesel engines, for valves and cylinder heads
Chromium Oxide for dense, corrosion-resistant coatings in pump gaskets or wearing rings
Aluminium Oxide for applications in the textile industry and synthetic fibre industry which demand wear-resistant surfaces, e.g. thread guiding rolls
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Al2O3 ( Aluminium Oxide) coatings. Application: electric insulation for induction loops in induction heating units
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Close-up of a Al2O3 coating. Between substrate and ceramic coating you can see the bond coating.
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Properties:
- electrically insulating
- resistant against acids, alkalis and alcohol
- wear resistant up to approx. 900 ° celsius
- Heat-resisting up to approx. 1600°Celsius (depending on operating conditions)
- erosion-resistant over 845°Celsius
- thermo shock resistant
- resistant against hot corrosion in sulphur chlorine and sodium bearing atmosphere
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