| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Journal of the American Ceramic Society Awards Symposium
|
| Presentation Title |
Unique Performance of Thermal Barrier Coatings Made of Yttria Stabilized Zirconia at Extreme Temperatures (> 1500°C) |
| Author(s) |
Robert Vassen, Daniel Emil Mack, Martin Tandler, Yoo Jung Sohn, Doris Sebold, Olivier Guillon |
| On-Site Speaker (Planned) |
Robert Vassen |
| Abstract Scope |
Yttria stabilized zirconia (YSZ) as state of the art material for thermal barrier coatings has unique properties, further efficiency improvement is limited due to its maximum temperature capability of about 1200°C. Above this temperature the deposited metastable t´ phase undergoes a detrimental phase transformation as well as enhanced sintering. We show here for the first time experimentally, that under typical cycling conditions not the dwell time at elevated temperatures plays the major role for the reduced lifetime but the transient cooling rates. If cooling rates were reduced, TBC systems could be operated in a burner rig at a surface temperature well above 1500°C without lifetime reduction. These astonishing findings can be explained by the evaluation of energy release rate peaks during fast transient cooling in combination with the phase evolution. Furthermore, also recent experiments with dwell times included during the cooling phase will be presented and discussed. |