Microstructural Characterization of Thermally Grown Oxide in Atmospheric Plasma Sprayed Thermal Barier Coatings

conference proceedings

English

Thermal barrier coating system is usually composed of nickel or cobalt based superalloy, metallic bond coat (M-CrAlY, where M means Ni, Co or their appropriate combination) and ceramic top coat (ZrO2+6-8%Y2O3) [1]. As the bond coats are primarily applied to protect the underlying metallic substrate against the oxidizing and hot-corrosive environment, the principal function of TBC, as its name suggests, is to reduce the metallic substrate temperature and thereby either increase the service life of the component or allow for higher combustion temperatures, which translates into increased aerospace engines efficiency. Together with active air cooling, TBCs can lower the substrate temperatures by more than 300oC, with the ceramic insulating coating alone credited with reducing the metal temperature by as much as 165oC [2,3]. The metallic bond coat serves as an oxidation resistant layer and protects the substrate against harsh working conditions. The bond coat also compensates the difference in CTE between the substrate and the top coat [4].

aluminium alloy;, thermal spraying; heat treatment; eutectic; scanning electron microscopy

ČELKO, L.; JECH, D.; SKALKA, P.; KLAKURKOVÁ, L.; SLÁMEČKA, K.; SPOTZ, Z.; ŠVEJCAR, J.

21. 7. 2013

Universidad de La Laguna

Spain

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