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Title: Effect of CMAS composition on hot corrosion behavior of gadolinium zirconate thermal barrier coating materials

The resistance of synthesized pyrochlore-type Gd 2Zr 2O 7 bulk specimens to four calcium-magnesium aluminosilicate (CMAS) compositions at different temperatures was investigated. The reaction products were identified by x-ray diffraction and penetration depths were examined using scanning electron microscopy. A dense reaction layer is comprised mainly of Ca 2Gd 8(SiO 4) 6O 2 and a cubic fluorite phase formed during the CMAS attack, and some unreacted CMAS was found in a transition layer below the reaction layer. The overall infiltration depth changed slightly with temperature, however, the thickness of the reaction layer and the morphology of the transition layer varied distinctly with temperature. The sintered sample underwent the most severe degradation by the CaO-lean CMAS, whereas the effect of CaSO 4 and CaCO 3 was not significant. Furthermore, the Gd content of the ZrO 2-based cubic fluorite phase depends on the temperature and the molar ratio of Ca:Si in the CMAS.
 [1] ;  [1]
  1. Auburn Univ., Auburn, AL (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of the Electrochemical Society
Additional Journal Information:
Journal Volume: 164; Journal Issue: 9; Journal ID: ISSN 0013-4651
The Electrochemical Society
Research Org:
Auburn Univ., AL (United States)
Sponsoring Org:
USDOE Office of Fossil Energy (FE), Clean Coal and Carbon (FE-20)
Country of Publication:
United States
36 MATERIALS SCIENCE; CMAS; fluorite; Gd2Zr2O7; pyrochlore; thermal barrier coatings
OSTI Identifier: