Design of thermal barrier coatings using gadolinium zirconate ceramics: A study on gadolinium zirconate/YSZ bilayers
Daehyung LEE, Tae Woo KIM, Kee Sung LEE
Journal of the Ceramic Society of Japan
Abstract
FEM analysis and experiments are undertaken in this study for designing double ceramic-layered thermal barrier coatings (TBCs) to improve the resistance of coating layers to mechanical percussion. Double-coating layers, which comprise of a ther- mally insulating, Gd2Zr2O7-based layer upon a thermally adjustable, YSZ layer, are analyzed and designed with reference to indentation stress, and deposited by electron beam physical vapor deposition (EB PVD). Additional analysis is also performed to find the optimal coating thickness. Linear elastic behaviors are assumed for the analysis, and the indentation stress strain curves of the double-layer TBCs are compared with those of single-layer TBCs. The results from FEM analysis and experi- ments that use the Hertzian indentation technique indicate the advantage of double-layered TBCs for alleviating stress.
Keywords:Thermal barrier coatings; Hardness; Indentation; Gadolinium zirconate; Electron-beam physical vapor deposition
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