TERMAL BARİYER KAPLAMA SİSTEMLERİNDE YÜKSEK SICAKLIKTA DÜŞÜK ÇEVRİMLİ YORULMA ŞARTLARI ALTINDA OLUŞAN HASARLARIN İNCELENMESİ
Thermal Barrier Coatings (TBCs) are multi-layer protective coatings used in the hot section components such as combustor and turbine of advanced gas turbine engines to protect them from degrading affects of hot gases. Today, due to lack of a reliable life time assessment, the potential of these co...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Turkish Air Force Academy
2009-07-01
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| Series: | Havacılık ve Uzay Teknolojileri Dergisi |
| Subjects: | |
| Online Access: | http://www.jast.hho.edu.tr/JAST/index.php/JAST/article/view/206/195 |
| Summary: | Thermal Barrier Coatings (TBCs) are multi-layer protective coatings used in the hot section components such as
combustor and turbine of advanced gas turbine engines to protect them from degrading affects of hot gases.
Today, due to lack of a reliable life time assessment, the potential of these coatings cannot be fully used.
Understanding of damage mechanisms of thermal barrier coatings is the key factor to increase durability and
reliability.
In this paper TBCs are shortly introduced and then damages resulting from high temperature low cycle fatigue
tests and their probable reasons have been explained. Inconel 100, a directionally solidified nickel based
superalloy as a substrate, approximately 120 μm thick NiCoCrAlY bond coat and approximately 200 μm thick 7
wt % Yttria Stabilized Zirconia ceramic top coat have been used. Both layers are deposited by EB-PVD
technique. The results of the tests show that number and the size of the cracks changes with the strain range.
Cracks initiate in the TGO/BC interface and propagate into the substrate perpendicularly to the loading axes.
Ceramic thermal barrier coating retards the formation of cracks. On the surfaces of the specimens having only
bond coat, rumpling which is a typical service damage of turbine blades has been detected. |
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| ISSN: | 1304-0448 1304-0448 |