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Monitoring Delamination of Thermal Barrier Coating During Interrupted High-Heat Flux Laser Testing Using Upconversion Luminescence ImagingUpconversion luminescence imaging of thermal barrier coatings (TBCs) has been shown to successfully monitor TBC delamination progression during interrupted furnace cycling. However, furnace cycling does not adequately model engine conditions where TBC-coated components are subjected to significant heat fluxes that produce through-thickness temperature gradients that may alter both the rate and path of delamination progression. Therefore, new measurements are presented based on luminescence imaging of TBC-coated specimens subjected to interrupted high-heat-flux laser cycling exposures that much better simulate the thermal gradients present in engine conditions. The TBCs tested were deposited by electron-beam physical vapor deposition (EB-PVD) and were composed of 7wt% yttria-stabilized zirconia (7YSZ) with an integrated delamination sensing layer composed of 7YSZ co-doped with erbium and ytterbium (7YSZ:Er,Yb). The high-heat-flux exposures that produce the desired through-thickness thermal gradients were performed using a high power CO2 laser operating at a wavelength of 10.6 microns. Upconversion luminescence images revealed the debond progression produced by the cyclic high-heat-flux exposures and these results were compared to that observed for furnace cycling.
Document ID
Document Type
Conference Paper
Eldridge, Jeffrey I.
(NASA Glenn Research Center Cleveland, OH, United States)
Zhu, Dongming
(NASA Glenn Research Center Cleveland, OH, United States)
Wolfe, Douglas E.
(Pennsylvania State Univ. University Park, PA, United States)
Date Acquired
August 25, 2013
Publication Date
January 24, 2011
Subject Category
Fluid Mechanics And Thermodynamics
Report/Patent Number
Meeting Information
34th International Annual Conference on Advanced Ceramics and Composites(Daytona Beach, CA)
Funding Number(s)
WBS: WBS 561581.
Distribution Limits
Public Use Permitted.
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