| Project/Area Number |
18560678
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
TAKAHASHI Satoru Tokyo Metropolitan University, Graduate School of Science and Engineering, Assistant Professor (80260785)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,750,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥150,000)
Fiscal Year 2007: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2006: ¥3,100,000 (Direct Cost: ¥3,100,000)
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| Keywords | High Temperature Materials / Thermal Barrier Coating / Failure Analysis / In-situ Observation / 遮熱コーディング / 溶射 |
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| Research Abstract |
Thermal barrier coating (TBC) systems have become today one of the indispensable technologies for hot-section components of advanced gas turbines. It is required to clarify the failure mechanism of TBC system under the complex modes of thermal-mechanical loadings for designing reasonably the advanced TBC system with more superior durability and reliability.
In the present study, in situ observation apparatus of TBC system failure behavior under various mechanical loadings was developed. Then, the crack initiation and propagation behavior of TBC systems with different coating microstructure were investigated under various mechanical loadings such as static creep dynamic fatigue and so on at room and elevated temperature and proposed the control plan for thermal-mechanical failure. The summary of results obtained is as follows ;
1)Under static creep loading, TBC system exhibits the typical creep rupture behavior with the manner of the nucleation and coalescence of mainly the grain boundary cracks in the alloy substrate interior,because the propagation of macrocracks developed in the ceramic top-coat (TC) into the metallic bond-coat (BC) and substrate can be prevented effectively by virtue of the stress relief due to the large magnitude of plastic flow in the BC layer at the elevated temperature which is higher than the ductile-brittle transition temperature (DBTT) of the BC.
2)Under dynamic fatigue loading, the failure behaviour of TBC systems depends strongly on the TC microstructure and the geometric morphology of the TC/BC interface. For all TBC systems, the concave region on the TC/BC interface and tip of macrocrack penetrating through the TC provides a nucleation site for the fatigue crack regardless of the DBTT of BC.
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