Sodium Vanadate-SO3 Equilibria in the Hot Corrosion of Zirconia Thermal Barrier Coatings

  • R. L. Jones


This paper describes a thermogravimetric study of the interaction of SO3 (as from engine gas) with vanadate-sulfate deposits at 700 and 800°C, and its effect on the reaction of the melt with ceramic oxides. Experiments using NaVO3 to simulate deposits having Na/V = 1, and where the controlling reaction is: 2 NaVO3 + SO3 = Na2SO4 + V2O5, gave reproducible equilibria over the range of 100 Pa to 0.01 Pa of SO3. India (In2O3, a possible corrosion-resistant stabilizer for ZrO2) was shown to be inert to the NaVO3-Na2SO4-V2O5 melt for SO3 levels up to about 5 Pa at 800°C (0.5 Pa at 700°C), where the melt V2O5 activity becomes increased enough that InVO4 begins to form. Although slow at lower SO3 pressures, the TGA-SO3 equilibria technique promises valuable information for understanding of the thermochemistry of vanadate-sulfate melts, and the development of corrosion-resistant engine ceramics.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Jones, R.L, Williams, C.B and Jones, S.R, Reaction of Vanadium Compounds with Ceramic Oxides. J. Electrochem. Soc., 1986, 133, 227–230.CrossRefGoogle Scholar
  2. 2.
    Siemers, P.A and McKee, D.W, Method of Coating a Superalloy Substrate, Coating Compositions, and Composites Obtained Therefrom. U.S. Pat. 4,328,285 (May 1982).Google Scholar
  3. 3.
    Jones, R.L and Ingel, R.P, Scandia-Stabilized Zirconia Coatings for Composites. U.S. Pat. 4,913,961 (April 1990).Google Scholar
  4. 4.
    Jones, R.L, to be publishedGoogle Scholar
  5. 5.
    Luthra, K.L and Spacil, H.S, Impurity Deposits in Gas Turbines from Fuels Containing Sodium and Vanadium. J. Electrochem. Soc., 1982, 129, 649–656.CrossRefGoogle Scholar
  6. 6.
    Mittal, S.K and Elliott, J.F, Thermodynamic Properties of Na2O-V2O5 Melts, 1030-1210 K. ibid., 1984, 131, 1194–1199.Google Scholar
  7. 7.
    Hwang, Y.-S and Rapp, R.A, Thermochemistry and Solubilities of Oxides in Sodium Sulfate-Vanadate Solutions. Corros., 1989,45,933–937.CrossRefGoogle Scholar
  8. 8.
    Berger, A.W, Driscoll, J.N and Morgenstern, P, Review and Statistical Analysis of Stack Sampling Procedures for the Sulfur and Nitrogen Oxides in Fossil Fuel Combustion. Am. Ind. Hygiene Assoc. J., 1972,33,397–405.CrossRefGoogle Scholar

Copyright information

© Elsevier Science Publishers Ltd and MPA Stuttgart 1992

Authors and Affiliations

  • R. L. Jones
    • 1
  1. 1.Naval Research LaboratoryUSA

Personalised recommendations