Application of infrared imaging to the study of controlled failure of thermal barrier coatings

A technique that uses high resolution infrared (IR) imaging was developed to track and analyze damage evolution of thermal barrier coatings (TBCs) during controlled mechanical testing of a TBC specimen. Coating debonding and spallation were examined during a monotonic load-to-TBC-failure test. The infrared imaging, in concert with a controlled thermal gradient in the specimen, was particularly effective in identifying and tracking localized damage evolution because the damage in the TBC was always associated with a measurable surface-temperature change. It is demonstrated that the combined use of high-resolution infrared imaging and controlled mechanical testing of TBCs is an effective method to characterize the evolution of their failure.