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| Home > Publications database > Degradation and Failure Modes of Advanced Materials in CMAS Burner Rig Testing |
| Home > Publications database > Degradation and Failure Modes of Advanced Materials in CMAS Burner Rig Testing |
| Conference Presentation (Invited) | FZJ-2015-07789 |
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2015
Abstract: Facing the demands on efficiency and operational flexibility of gas turbines advanced materials solutions allowing for use at increased turbine inlet temperatures are being developed with considerable progress. In addition to the extreme thermomechanical loads in the hottest part of the gas turbines also degradation of ceramic thermal barrier coatings (TBCs) due to calcium–magnesium–aluminosilicate (CMAS) glassy deposits from various sources has become a persistent challenge since some years. Meanwhile the understanding of the mechanism of CMAS induced degradation of TBC as well as approaches for mitigating CMAS attack by means of advanced TBC compositions have grown remarkably. However, most of the reported results have been obtained from isothermal lab testing or evaluation of ex-service components either.In this study a burner rig facility has been used for the evaluation of advanced TBC performance, where a thermal gradient is applied across the TBC, with simultaneous injection of CMAS to simulate the conditions closer to actual service in an engine. Tests have been performed on TBC systems comprising top coats from advanced materials as pyrochlores, garnets, hexaaluminates, spinels, or alumina. Characterization after test has been done by means of SEM, EDX and XRD. Major impacts of chemical degradation and mitigation mechanism on thermal gradient cycling lifetime are reviewed.
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