Evaluation of thickness, porosity and pore shape of plasma sprayed TBC by electrochemical impedance spectroscopy

    Authors

    J. Zhang;V. Desai

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    Surf. Coat. Technol.

    Keywords

    impedance spectroscopy; porosity; thickness; plasma spraying; zirconium; oxide; thermal barrier coating; THERMAL BARRIER COATINGS; YTTRIA-STABILIZED ZIRCONIA; ORGANIC COATINGS; NONDESTRUCTIVE EVALUATION; AC-IMPEDANCE; BOND-COAT; NICKEL; ELECTRODEPOSITION; PASSIVATION MECHANISM; ELECTRICAL-PROPERTIES; ELECTRONIC TRANSPORT; Materials Science, Coatings & Films; Physics, Applied

    Abstract

    An equivalent circuit of electrochemical impedance spectroscopy (EIS) was suggested to model the morphological structure of nonexposure thermal barrier coating (TBC). The morphological properties of as-coated air plasma sprayed (APS) TBC were correlated with the EIS parameters. A linear relationship between TBC topcoat thickness, D-c, and ceramic resistance, R-c, has been found particularly When the TBC have the same porosity. The TBC porosity, P, shows to be a function of ceramic thickness, D-c, and porosity, P; in particular, it shows a proportional relationship with ceramic capacitance, C-c, when ceramic thickness, D-c, is kept unchanged. The pore size and shape in the TBC topcoat can be assessed by the pore resistance, R-p, as measured by EIS. The results indicate that electrochemical impedance spectroscopy can be used for quality assurance of TBC and, in particular, to evaluate TBC ceramic topcoat thickness, porosity and kinds of defects. (C) 2004 Elsevier B.V. All rights reserved.

    Journal Title

    Surface & Coatings Technology

    Volume

    190

    Issue/Number

    1

    Publication Date

    1-1-2005

    Document Type

    Article

    Language

    English

    First Page

    98

    Last Page

    109

    WOS Identifier

    WOS:000225305300014

    ISSN

    0257-8972

    Share

    COinS