This title appears in the Scientific Report :
2004
Please use the identifier:
http://dx.doi.org/10.1361/10599630420443 in citations.
Correlation between spraying conditions and micro crack density and their influence on thermal cycling life of thermal barrier coatings
Correlation between spraying conditions and micro crack density and their influence on thermal cycling life of thermal barrier coatings
It is generally known that the porosity of thermal barrier coatings is essential to guarantee a sufficiently high strain tolerance of the coating during thermal cycling. However, much less is known about the influence of the specific morphology of porosity, such as microcracks and typically larger p...
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Personal Name(s): | Vaßen, R. |
---|---|
Träger, F. / Stöver, D. | |
Contributing Institute: |
Werkstoffsynthese und Herstellungsverfahren; IWV-1 |
Published in: | Journal of thermal spray technology, 13 (2004) S. 396 - 404 |
Imprint: |
Boston, Mass.
Springer
2004
|
Physical Description: |
396 - 404 |
DOI: |
10.1361/10599630420443 |
Document Type: |
Journal Article |
Research Program: |
Werkstoffsysteme für Kraftwerke |
Series Title: |
Journal of Thermal Spray Technology
13 |
Subject (ZB): | |
Publikationsportal JuSER |
It is generally known that the porosity of thermal barrier coatings is essential to guarantee a sufficiently high strain tolerance of the coating during thermal cycling. However, much less is known about the influence of the specific morphology of porosity, such as microcracks and typically larger pores, on the performance of the coatings. Both features are usually formed during plasma spraying of yttria-stabilized zirconia (VSZ) thermal barrier coatings (TBCs). In this investigation, the influence of microcracks on the thermal cycling behavior was studied. The amount of microcracks within VSZ thermal barrier coatings was changed by changing the powder-feeding rate. Only small changes of the total porosity were observed. Mercury porosimetry served as a tool to investigate both the amount of microcracks and pores in the coating. Additionally, microcrack densities were determined from metallographical investigations. A linear dependence between the amount of fine pores determined by Hg porosimetry and the crack density was obtained for one set of coatings. Thermal cycling TBC specimens with different microcrack densities were produced and tested in a gas burner test facility. At high surface temperatures (above 1300 degreesC), failure occurred in the ceramic close to the surface. Under these conditions, the samples with increased horizontal microcrack densities showed a significant increase of thermal cycling life. |