Thermal Barrier Coating (TBC) Lifing Technology using In-Situ Luminescence Imaging of Embedded Thermographic Phosphors

Since the remnant life of a thermal barrier coating (TBC) structure depends critically on the temperature history at the TBC/bondcoat interface, the development of viable lifing prognostics requires instrumentation to obtain accurate interface temperature data as input to life models. Such data is preferably obtained in real time and with sufficient spatial resolution to identify hot-spots. New advances in embedding thermographic phosphors within the very crystal structure of real TBC materials, and at sufficiently dilute concentrations not to affect the TBC microstructure, provide an opportunity for the first time to monitor temperature at the interface, in real-time, under realistic engine operation conditions. In this proposal we outline a plan to address TBC lifing in terms of a crucial combination of materials development, optical sensor instrumentation and life modeling. The materials science is being pioneered at the University of California Santa Barbara, which forms the basis of this proposal. During Phase I we will determine the feasible instrument requirements for interface temperature imaging, test a suitable lifing model, demonstrate the measurement concept and design a prototype to be developed during Phase II and tested in a thermal gradient burner rig.