On TGO creep and the initiation of a class of fatigue cracks in thermal barrier coatings

SURFACE & COATINGS TECHNOLOGY

卷:203

Article

Hernandez, Mercedes T.¹  Karlsson, Anette M.¹  Bartsch, Marion² 

[1] Univ Delaware, Dept Mech Engn, Newark, DE 19716 USA

[2] German Aerosp Ctr DLR, Inst Mat Res, D-51147 Cologne, Germany

关键词: Thermal barrier coatings;    Thermally grown oxide;    Creep;    Fatigue cracks;    Finite element analysis;   

DOI  :  10.1016/j.surfcoat.2009.05.018

来源: Elsevier

【 摘 要 】

The initiation of a class of fatigue cracks observed in thermal barrier coatings (TBCs) subjected to thermal gradient mechanical fatigue testing is investigated. The coating system is based on a NiCoCrAlY bond coat and a partially yttria stabilized zirconia top coat. To explain the development of the cracks of interest, the thermo-mechanical response of the bond coat and the thermally grown oxide (TCO) is examined and quantified through finite element analyses. The models include non-linear and time-dependent behavior such as creep, TGO growth stress, and thermo-mechanical cyclic loading. The simulations suggest that stress-redistribution due to creep can lead to tensile stresses in the TGO during TGMF testing that are large enough to initiate the cracks investigated. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

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