Title

Characterization Of Isothermally Oxidized Zro2-8Wt.%Y 2O3 Thermal Barrier Coatings By Electrochemical Impedance Spectroscopy

Keywords

Electrochemical impedance spectroscopy; Isothermal oxidation; Nondestructive evaluation; Thermal barrier coating; Thermally grown oxide

Abstract

Electrochemical impedance spectroscopy was employed to examine ZrO 2-8wt.%Y2O3 (yttria stabilized zirconia, YSZ) thermal barrier coating (TBC) as a function of isothermal exposure time at 1121°C. Electrochemical impedance response (resistance and capacitance of YSZ and thermally grown oxide (TGO)) of TBC specimens was analyzed with an alternative current equivalent circuit based on the multi-layered micro-constituents of TBC, and the impedance response was correlated with microstructural changes attributed to isothermal oxidation. The resistance of YSZ was observed to increase initially and then decrease with thermal exposure. The initial increase was related to the high temperature sintering of YSZ, and the subsequent decrease was discussed in terms of microcrack initiation and electrolyte penetration. The TGO thickness was linearly correlated to the capacitance of TGO.

Publication Date

1-1-2005

Publication Title

Materials Science Forum

Volume

486-487

Number of Pages

145-148

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.4028/0-87849-966-0.145

Socpus ID

35148901171 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/35148901171

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