Accession Number:

ADA273403

Title:

An X-Ray Diffraction Investigation of alpha-Al2O2 Addition to Yttria Stabilized Zirconia (YSZ) Thermal Barrier Coatings Subject to Destabilizing Vanadium Pentoxide (V2O5) Exposure

Descriptive Note:

Master's thesis

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

Report Date:

1993-09-01

Pagination or Media Count:

79.0

Abstract:

Since the mid 1970s the U.S. Navy has used Yttria-stabilized zirconia YSZ as thermal barrier coatings for hot stage gas turbine components. Use of low cost, high contaminant, fuels has led to shortened component life from failure of YSZ coatings due to corrosive attack by vanadium and other combustion oxides. The object of this investigation was to determine the reactivity of adding alpha-Al203 to Current YSZ ceramics for creation of a ceramic composite which could improve mechanical properties and show improved durability to corrosive chemical attack. Ten powder samples of Zro28MolYzO3, alpha-Al2O3, and V20s5 of varying compositions were annealed at 900 deg C for 100 hours. X-Ray Diffraction analysis utilizing a standard search and match method was used to determine the phases present in the reacted powder samples. Peak intensity comparisons between reacted and un-reacted samples allowed for a quantitative determination for the reactivity of a-A1203 with the YSZ system exposed to V2O3. This investigation indicated that alpha-Al2O3 is non-reactive in all YSZ samples exposed to V205 at 900 deg C. Ceramic, Alpha alumina, YSZ, Vanadia, Surface-induced coating SIC, PSZ, XRD, SEM.

Subject Categories:

  • Inorganic Chemistry
  • Coatings, Colorants and Finishes
  • Fuels
  • Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE