STP1392: Effect of Loading Mode on High-Temperature Tensile Deformation of a SiC/SiC Composite

    Ünal, Ü
    Associate Ceramist, Ames Laboratory, 207 Metals Development, Ames, IA

    Pages: 14    Published: Jan 2000


    Abstract

    Tensile deformation of a silicon carbide (SiC) matrix/Nicalon SiC fiber composite was studied under static and cyclic loads at 1300°C in nitrogen environment. Monotonic tensile tests were carried out to determine the stress levels to be applied during the ensuing tests. It was shown that under comparable stresses, higher strain accumulates under the static loads than the cyclic loads. Yet, the failure took place much more readily under the cyclic loads because of the damages induced on the load carrying O°-fibers. When the applied cyclic loads were small, the total strain and the rate of strain accumulation were similar under both types of loading, indicating similar deformation mechanisms in this range. At higher loads, however, under the cyclic loading, the matrix and fiber cracking controlled the deformation; under the static loading, the fiber creep dominated the deformation.

    Keywords:

    silicon carbide composite, tensile, creep, fatigue and high temperature


    Paper ID: STP15019S

    Committee/Subcommittee: D30.04

    DOI: 10.1520/STP15019S


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