Skip to main navigation Skip to search Skip to main content

Evolution of Surface Morphology of Thermo-Mechanically Cycled NiCoCrAlY Bond Coats

    • University of Delaware
    • German Aerospace Center

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We investigate morphological surface instabilities on bond coat surfaces of thermal barrier coatings, induced due to thermo-mechanical loading. Experimental results of hollow circular cylindrical specimens, consisting of a directionally solidified superalloy (IN 100 DS) coated with a NiCoCrAlY bond coat, show that the morphological instabilities are strongly dependent on the load conditions. In particular, the morphological instabilities develop during thermal cycling with a thermal gradient over the cylinder wall, whereas the surface remains smooth for thermal cyclic conditions without a gradient. Furthermore, if a cyclic, axial tensile force is applied (synchronized with the thermal cycling), the morphological instabilities become aligned with the axial direction. We discuss a model, quantified by finite element simulations, capturing this behavior and elucidating the thermo-mechanical response.

    Original languageAmerican English
    JournalMaterials Science & Engineering A
    Volume434
    DOIs
    StatePublished - Oct 25 2006

    Keywords

    • Elastic– plastic material; Finite elements; Thermo-mechanical testing; Thermal barrier coatings; Thermal cycling; Oxidation

    Disciplines

    • Mechanical Engineering

    Cite this