Accession Number : ADA307697

Title :   Experiences in Seeking Stabilizers for Zirconia Having Hot Corrosion-Resistance and High Temperature Tetragonal (t') Stability.

Descriptive Note : Interim rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC SURFACE CHEMISTRY BRANCH

Personal Author(s) : Jones, Robert L.

PDF Url : ADA307697

Report Date : 16 APR 1996

Pagination or Media Count : 24

Abstract : This report summarizes the results of a research effort aimed at identifying hot corrosion-resistant stabilizers for zirconia (ZrO2) which could be used in zirconia-based thermal barrier coatings (TBCs) for engines operating on marine fuel under sea-going conditions. Among the oxides investigated were TiO2, CeO2, Y2O3, MgO, Sc2O3, In2O3, and SnO2. A brief overview of the hot corrosion of zirconia TBCs is given to illustrate the rationale used in evaluating the hot corrosion performance of the candidate oxides. The most promising stabilizer found for hot corrosion resistance was Sc2O3, or perhaps mixtures of Sc2O3 and small amounts of Y2O3. It was also discovered that Sc2Os, Y2O3- stabilized ZrO2 (SYSZ), of approx. 7 mol% of total stabilizer of which 5-20% is Y2O3, shows improved 1400 deg C stability of the tetragonal (t') phase as compared to present-day Y2O3-stabilized ZrO2 TBC compositions. This new material may have potential for TBC use in future high temperature, high efficiency gas turbine engines.

Descriptors :   *STABILITY, *HIGH TEMPERATURE, *COATINGS, *CORROSION RESISTANCE, *ZIRCONIUM OXIDES, *STABILIZATION SYSTEMS, THERMAL PROPERTIES, METALS, MAGNESIUM, SHIPS, MATERIALS, FUELS, GAS TURBINES, OXIDES, CERIUM, BARRIERS, ENGINES, TIN, TITANIUM, INDIUM, YTTRIUM OXIDES, SCANDIUM.

Subject Categories : Inorganic Chemistry
      Properties of Metals and Alloys
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE