Modeling of Thermal Stresses in Yttrium Aluminum Garnet and Alumina Fibers Coated with β″-Alumina

    Volume 21, Issue 4 (October 1999)

    ISSN: 0884-6804

    CODEN: CTROAD

    Page Count: 9


    Ellenburg, MG
    Graduate student, Georgia Institute of Technology, Atlanta, GA

    Lackey, WJ
    Professor, George W. Woodruff School of Mechanical Engineering, Atlanta, GA

    (Received 7 October 1996; accepted 13 July 1999)

    Abstract

    Since layered aluminate coatings such as β″-alumina are being considered for tailoring the interfacial properties of oxidation-resistant fiber-reinforced composites, stresses arising from thermal expansion mismatch were calculated for the substrate fiber and coating. Both isotropic and anisotropic β″-alumina coatings were analyzed for yttrium aluminum garnet and single crystal and polycrystalline alumina fibers. It was possible to rank the various fiber-coating combinations in terms of the magnitude of maximum tensile stresses present in the coating. Polycrystalline alumina + isotropic β″-alumina yielded the lowest tensile stresses with radial stress on the order of 10 MPa, while single crystal alumina + anisotropic β″-alumina yielded the highest tensile stresses with tangential stress on the order of >100 MPa.


    Paper ID: CTR10982J

    DOI: 10.1520/CTR10982J

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    Author
    Title Modeling of Thermal Stresses in Yttrium Aluminum Garnet and Alumina Fibers Coated with β″-Alumina
    Symposium , 0000-00-00
    Committee D30