Reactions of yttria-stabilized zirconia with oxides and sulfates of various elements. [8 wt % yttria, 1200 to 1400/sup 0/C]
Zirconia-based coatings are being evaluated as thermal barriers for air-cooled gas-turbine components. The reactions between partially stabilized zirconia, containing 8-weight-percent yttria, and oxides and sulfates of various elements were studied at 1200/sup 0/, 1300/sup 0/, and 1400/sup 0/C for times to 800, 400, and 200 hours, respectively. These oxides and sulfates represent impurities and additives potentially present in gas turbine fuels or impurities in the turbine combustion air as well as the elements of the substrate alloys in contact with zirconia. Based on the results, these compounds can be classified in four groups: compounds which did not react with zirconia (Na/sub 2/SO/sub 4/, K/sub 2/SO/sub 4/, Cr/sub 2/O/sub 3/, Al/sub 2/O/sub 3/ and NiO); compounds that reacted completely with both zirconia phases (CaO, BaO, and BaSO/sub 4/); compounds that reacted preferentially with monoclinic zirconia (Na/sub 2/O, K/sub 2/O, CoO, Fe/sub 2/O/sub 3/, MgO, SiO/sub 2/, and ZnO); and compounds that reacted preferentially with cubic zirconia (V/sub 2/O/sub 5/, P/sub 2/O/sub 5/). The phase compositions of the reaction products were determined by x-ray diffraction analysis. 1 figure, 1 table.
- Research Organization:
- National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
- DOE Contract Number:
- EF-77-A-01-2593
- OSTI ID:
- 6700072
- Report Number(s):
- DOE/NASA/2593-78/1; NASA-TM-78942
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
GAS TURBINES
PROTECTIVE COATINGS
OXIDES
CHEMICAL REACTIONS
SULFATES
ZIRCONIUM OXIDES
ADDITIVES
AIRCRAFT COMPONENTS
IMPURITIES
VERY HIGH TEMPERATURE
YTTRIUM OXIDES
CHALCOGENIDES
COATINGS
OXYGEN COMPOUNDS
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TURBINES
TURBOMACHINERY
YTTRIUM COMPOUNDS
ZIRCONIUM COMPOUNDS
360205* - Ceramics
Cermets
& Refractories- Corrosion & Erosion
400201 - Chemical & Physicochemical Properties