This title appears in the Scientific Report :
2022
Please use the identifier:
http://hdl.handle.net/2128/31073 in citations.
Please use the identifier: http://dx.doi.org/10.1016/j.surfcoat.2022.128353 in citations.
Degradation and lifetime of self-healing thermal barrier coatings containing MoSi2 as self-healing particles in thermo-cycling testing
Degradation and lifetime of self-healing thermal barrier coatings containing MoSi2 as self-healing particles in thermo-cycling testing
Yttria-stabilized zirconia (YSZ) is the state-of-the-art top coat material for thermal barrier coatings (TBCs) applied on highly loaded gas turbine parts. During operation at high temperatures, stresses are induced by the thermal expansion coefficient mismatch between the ceramic TBC and the metalli...
Saved in:
Personal Name(s): | Koch, Denise (Corresponding author) |
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Mack, Daniel E. / Vaßen, Robert | |
Contributing Institute: |
Werkstoffsynthese und Herstellungsverfahren; IEK-1 |
Published in: | Surface and coatings technology, 437 (2022) S. 128353 - |
Imprint: |
Amsterdam [u.a.]
Elsevier Science
2022
|
DOI: |
10.1016/j.surfcoat.2022.128353 |
Document Type: |
Journal Article |
Research Program: |
Gas turbines |
Link: |
Restricted Published on 2022-03-17. Available in OpenAccess from 2024-03-17. |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1016/j.surfcoat.2022.128353 in citations.
Yttria-stabilized zirconia (YSZ) is the state-of-the-art top coat material for thermal barrier coatings (TBCs) applied on highly loaded gas turbine parts. During operation at high temperatures, stresses are induced by the thermal expansion coefficient mismatch between the ceramic TBC and the metallic substrate. As a consequence cracks can grow, propagate and finally lead to a spallation of the top coat. Using atmospheric plasma spraying (APS), so-called self-healing MoSi2 particles can be incorporated into the YSZ matrix to mitigate the propagation of cracks leading to a lifetime gain and possibly higher temperature capability of the TBC. In the present work, the healing process is realized by the oxidation of the self-healing particles, which introduces a volume expansion by a formation of reaction products, which can seal the cracks. The self-healing particles were introduced within the first 150 μm of the YSZ coating matrix immediately on top of the bond coat. The degradation and lifetime of such systems were studied in furnace cycling and in burner rig tests, in which a temperature gradient through the sample was applied. The lifetime of the self-healing coatings was then compared to the lifetime of an YSZ coating without self-healing particles. In burner rig tests a clear lifetime extension of the self-healing TBCs was observed. The origin of this different behavior was investigated by microstructural analysis in scanning electron microscopy. A further insight into the failure mechanisms was gained by the analysis of a self-healing TBC cycled in a furnace cycling test only for about 55% of its expected lifetime. |