Non-destructive evaluation of degradation in EB-PVD thermal barrier coatings by infrared reflectance spectroscopy

Journal Article · Fri Jan 25 00:00:00 EST 2013 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4789169· OSTI ID:22115972

Flattum, Richard Y.; Cooney, Adam T. ^[1]

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1. Air Force Research Laboratory, Materials and Manufacturing Directorate, NonDestructive Evaluation Branch, Wright-Patterson AFB, OH (United States)

At room temperature and atmospheric conditions infrared reflectance spectroscopy and X-ray diffraction were employed for the detection of the phase transformation and residual stress within thermal barrier coatings (TBC). The TBC's samples initially consisted of the porous ceramic topcoat deposited by electron beam plasma vapor deposition, a bond coat and a superalloy substrate. Reflectance spectroscopy scans were performed from 7497 cm{sup -1} to 68 cm{sup -1} to analysis the fingerprint region as well as the chemical bonding region. These regions should indicate if a detectable change within the TBC response is a result of thermal degradation of the microstructure and the changes in yttrium dispersion throughout the yttrium stabilized zirconium. The thermal degradation was induced by thermal cycling the samples to 1100 Degree-Sign C and then cooling them in an atmospheric environment. X-ray diffraction was also used to detect the phase composition within the TBC samples and see if either would clearly identify failure prior to actual spallation. The eventual measurability and quantify-ability of the phase changes within the TBC's may be used as an effective non-destructive evaluation (NDE) technique that would allow personnel in the field to know when servicing of the turbine blade was necessary.

• OSTI ID: 22115972
• Journal Information: AIP Conference Proceedings, Vol. 1511, Issue 1; Conference: 39. annual review of progress in quantitative nondestructive evaluation, Denver, CO (United States), 15-20 Jul 2012; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
CERAMICS
CHEMICAL BONDS
CRYSTAL STRUCTURE
INFRARED SPECTRA
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
NONDESTRUCTIVE TESTING
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SPECTRAL REFLECTANCE
SUBSTRATES
TEMPERATURE RANGE 0273-0400 K
THERMAL CYCLING
THERMAL DEGRADATION
TURBINE BLADES
ZIRCONIUM