Abstract
It is demonstrated that the addition of Pt to CoNiCrAlY overlay coating can significantly improve its oxidation resistance and thermal stability as well as its performance in thermal barrier coatings. The addition of Pt is found to stabilize a surface layer with composition based upon NiAlPt2 with L1o superlattice in addition to enhancing a more favorable distribution of Y and restricting the outward diffusion of detrimental substrate elements particularly Ta and Ti. Due to these beneficial effects, utilizing the Pt-modified bond coating in a TBC system with top coating of zirconia stabilized by yttria is found to extend its lifetime from 410 ± 42 h to 956 ± 48 h as determined from cycling oxidation tests at 1150 °C. However, spallation of the top coatings in the two systems has been correlated with loss of oxide adherence to the bond coatings.
| Original language | English |
|---|---|
| Pages (from-to) | 383-399 |
| Number of pages | 17 |
| Journal | Oxidation of Metals |
| Volume | 90 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - 1 Oct 2018 |
Bibliographical note
Publisher Copyright:© 2018, Springer Science+Business Media, LLC, part of Springer Nature.
Keywords
- Bond coatings
- Electron microscopy
- Oxidation
- Superalloys
- Thermal barrier coatings
ASJC Scopus subject areas
- Metals and Alloys
- Inorganic Chemistry
- Materials Chemistry