Abstract
Testing was conducted on both plasma-sprayed (PS) and electron beam-physical vapor deposited (EB-PVD) Y2O3-stabilized ZrO2 (YSZ) thermal barrier coatings (TBCs) applied directly to oxidation-resistant substrates such as β-NiAl, oxide-dispersed FeCrAl, and NiCr. On an alloy that forms a very adherent alumina scale, β-NiAl + Zr, the coating lifetime of YSZ in furnace cyclic tests was 6 or more times longer than on state-of-the-art, YSZ coatings on single-crystal Ni-base superalloys with MCrAlY or Pt aluminide bond coats. Coatings on FeCrAl alloys appear to be a viable option for applications such as the external skin of the X-33, single stage to orbit, reusable launch vehicle. Model chromia-forming bond coat compositions also show promise for power generation applications at temperatures where hot corrosion may be a major problem. In general, while this work examined unique materials systems, many of the same fundamental failure mechanisms observed in conventional TBCs were observed.
| Original language | English |
|---|---|
| Pages (from-to) | 198-203 |
| Number of pages | 6 |
| Journal | Journal of Thermal Spray Technology |
| Volume | 9 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jun 2000 |
Funding
The authors thank B.A. Nagaraj, J. Schaeffer, S. Walston, A. Maricocchi, D. Wortman, and R. Darolia at GEAE, K. Alexander at LANL, and P. Tortorelli, J. DeVan, A. Haynes, and J. Di-Stefano at ORNL for their assistance. All of the EB-PVD coating work was performed at GEAE. The OD NiAl was produced with the help of NASA Lewis and EPRI. The NiAl + Zr alloy was provided by J. Whittenberger at NASA Lewis. Work at ORNL was supported by the U.S. Department of Energy (DOE), Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Industrial Technologies, as part of the Advanced Turbine Systems Program, and by the ORNL Laboratory Directed Research and Development program under Contract No. DE-AC05-96OR22464 with Lockheed Martin Energy Research.