STP633: Use of State Variables in the Description of Irradiation Creep and Deformation of Metals

    Hart, EW
    Professor, Cornell UniversityCorporate Research and Development, IthacaSchenectady, N.Y.N.Y.

    Li, CY
    Professor, Cornell University, Ithaca, N.Y.

    Pages: 11    Published: Jan 1977


    Abstract

    Our understanding and mode of description of the effects of irradiation on metal creep and deformation are not satisfactory as yet. This is due in part to the limitations on experimentation in radiation environment. Because of such limitations, theoretical considerations must play a strong role in the interpretation and representation of the phenomena. Reliable representations are necessary if we are to extrapolate the measured behavior beyond the experimental ranges of stress, temperature, flux, and time duration. Virtually all of the theoretical considerations currently employed are based on micromechanical models for the deformation behavior. While the fundamental mechanisms proposed, in fact, may be identified correctly, it is not at all clear that the quantitative conclusions from them are accurate. After all, the detailed micro-mechanical description of deformation even in the absence of irradiation is still moot.

    The recent theoretical and experimental development of a plastic equation of state for metal deformation has led to the identification of some of the principal micro-mechanisms in phenomenological terms. The role of the individual mechanisms can be related to the state variables of the description, and those variables are directly accessible measurable quantities.

    In this paper we will explore how irradiation might affect this description. It will be shown that the radiation flux and the radiation fluence are expected to affect different components of the equation of state. The resultant description makes considerable use of the information developed in radiation-free environment.

    Keywords:

    zirconium, creep properties, radiation, state variables


    Paper ID: STP35578S

    Committee/Subcommittee: B10.02

    DOI: 10.1520/STP35578S


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