title: Strain response of thermal barrier coatings captured under extreme engine environments through synchrotron X-ray diffraction.
abstract: The mechanical behaviour of thermal barrier coatings in operation holds the key to understanding durability of jet engine turbine blades. Here we report the results from experiments that monitor strains in the layers of a coating subjected to thermal gradients and mechanical loads representing extreme engine environments. Hollow cylindrical specimens, with electron beam physical vapour deposited coatings, were tested with internal cooling and external heating under various controlled conditions. High-energy synchrotron X-ray measurements captured the in situ strain response through the depth of each layer, revealing the link between these conditions and the evolution of local strains. Results of this study demonstrate that variations in these conditions create corresponding trends in depth-resolved strains with the largest effects displayed at or near the interface with the bond coat. With larger temperature drops across the coating, significant strain gradients are seen, which can contribute to failure modes occurring within the layer adjacent to the interface.
authors: Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida 32816, USA.
authors: Kevin
authors: K
authors: Knipe
authors: Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida 32816, USA.
authors: Albert
authors: A
authors: Manero
authors: Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida 32816, USA.
authors: Sanna F
authors: SF
authors: Siddiqui
authors: Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Werkstoff-Forschung, Linder Höhe 51147 Cologne Germany.
authors: Carla
authors: C
authors: Meid
authors: Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Werkstoff-Forschung, Linder Höhe 51147 Cologne Germany.
authors: Janine
authors: J
authors: Wischek
authors: X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors: John
authors: J
authors: Okasinski
authors: X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors: Jonathan
authors: J
authors: Almer
authors: Cleveland State University, 2121 Euclid Avenue, Cleveland, Ohio 44115, USA.
authors: Anette M
authors: AM
authors: Karlsson
authors: Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Werkstoff-Forschung, Linder Höhe 51147 Cologne Germany.
authors: Marion
authors: M
authors: Bartsch
authors: Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida 32816, USA.
authors: Seetha
authors: S
authors: Raghavan