Fraunhofer-Gesellschaft

Publica

Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

The water-vapour hot gas corrosion behavior of Al2O3-Y2O3 materials, Y2SiO5 and Y3Al5O12-coated alumina in a combustion environment

 
: Fritsch, M.; Klemm, H.

Zhu, D. ; American Ceramic Society -ACerS-, Westerville/Ohio:
Advanced ceramic coatings and interfaces : A collection of papers presented at the 30th International Conference on Advanced Ceramics and Composites, January 22 - 27, 2006, Cocoa Beach, Florida; Symposium on Advanced Ceramic Coatings for Structural, Environmental and Functional Applications
Hoboken, NJ: Wiley, 2007 (Ceramic engineering & science proceedings 27.2006,3)
ISBN: 0-470-08053-1
ISBN: 978-0-470-08053-5
pp.149-159
International Conference on Advanced Ceramics and Composites <30, 2006, Cocoa Beach/Fla.>
Symposium on Advanced Ceramic Coatings for Structural, Environmental and Functional Applications <2006, Cocoa Beach/Fla.>
English
Conference Paper
Fraunhofer IKTS ()
Yttriumverbindung; Aluminiumverbindung; Yttriumsilicat; Wasserdampfkorrosion; Heißdampf; Hochtemperaturbeständigkeit; Schutzschicht; alumina; combustion; corrosion; environmental degradation; garnet; silicon compound; surface phase transformation; thermal barrier coating; yttrium compound

Abstract
The water vapour hot gas corrosion behavior of various oxide ceramics in the Al2O3-Y2O3 system (alpha-Al2O3, Y2Al5O12+alpha-Al2O3, Y3Al5O12 [yttrium aluminium garnet, or YAG], YAlO3 [yttrium aluminium perovskite or YAP], Y4Al2O9 [yttrium aluminium monocline, or YAM], Y4Al2O9+Y2O3) and of Y2SiO5 was determined. The tests were performed in a high temperature burner rig at temperatures between 1200 deg C and 1500 deg C, water vapour partial pressure of 0.24 atm, a total pressure of 1 atm, gas flow velocity of 100 m/s and test times about 100 .. 350 hours. YAG, YAP and YAM showed an order of magnitude lower corrosion rate in comparison to alumina. Nevertheless degradation and phase changes on surface were observed above 1350 deg C. Y2SiO5 showed absolutely no degradation even after corrosion exposure at 1500 deg C. The dependence of the temperature is discussed by compositional and microstructural investigations. Finally corrosion issues about environmental barrier coatings (EBC) on bulk are discussed. In case of EBC YAG coated Al2O3 improved hot gas stability was observed.

: http://publica.fraunhofer.de/documents/N-55482.html