Abstract
A self‐healing thermal barrier coating (TBC) system is manufactured by air plasma spraying (APS) and tested by thermal cycling. The ceramic topcoat in the self‐healing APS TBC system consists of an yttria stabilised zirconia (YSZ) matrix and contains self‐shielding aluminium containing MoSi2 healing particles dispersed close to the topcoat/bond coat interface. After spraying the healing particles the material was annealed to promote the formation of an oxygen impermeable Al2O3 shell at the MoSi2‐TBC interfaces by selective oxidation of the aluminium fraction. The samples were subsequently thermally cycled between room temperature and 1100°C. The study focussed on the spontaneous formation of the Al2O3 shell as well as the subsequent damage evolution in the APS produced TBC during thermal cycling. Experimental evidence showing characteristic signs of crack healing in the topcoat is identified and analysed. The study shows that while the concept of the self‐healing APS TBCs containing self‐shielding MoSi2 particles is promising, future study is needed to improve the protectiveness of the Al2O3 shells by further tailoring the aluminium content in the MoSi2 and the particle shape to avoid the premature oxidation of the healing particles and maximise crack healing efficiency.
Original language | English |
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Pages (from-to) | 4899-4910 |
Journal | Journal of the American Ceramic Society |
Volume | 102 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2019 |
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-careOtherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Keywords
- Al-containing MoSi
- APS TBC
- oxidation
- self-healing
- self-shielding
- thermal cycling