STP1405

    Effects of Neutron Irradiation and Thermal Annealing on Model Alloys Using Positron Annihilation Techniques

    Published: Jan 2001


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    Abstract

    We present the results of a systematic investigation of neutron-irradiated and thermally annealed Fe-Cu-Ni-P model alloys using positron annihilation spectroscopy (PAS), including lifetime and Doppler broadening techniques, and Rockwell hardness. These alloys were examined in the as-fabricated state, after irradiation at 270° C to 1 × 1019 n.cm-2, and to 8 × 1019 n.cm-2, and after successive post-irradiation isochronal anneals at temperatures from 200 to 600° C. The results can be qualitatively explained by invoking an irradiation-induced microstructure consisting of a combination of small dislocation-type defects or defect clusters (matrix damage) and dense precipitation of fine scale irradiation-induced precipitates. The matrix damage anneals between 350° C and 450° C. The irradiation-induced precipitates also evolve with annealing, but at higher temperatures. The combined effect of high Cu and high Ni concentrations leads to more extensive irradiation-induced precipitation than in cases where either element is missing, whereas the effect of P is less pronounced. We analyze and compare the results with similar measurements performed on irradiated pressure-vessel steels and with other positron measurements on model alloys, reported in the literature.

    Keywords:

    positron annihilation, positron lifetime, Doppler broadening, irradiation hardening, model alloys, neutron irradiation, irradiation induced precipitates, matrix damage


    Author Information:

    Cumblidge, ES
    Professor and Associate Professor, The Pennsylvania State University, University Park, PA

    Catchen, GL
    Professor and Associate Professor, The Pennsylvania State University, University Park, PA

    Motta, AT
    Professor and Associate Professor, The Pennsylvania State University, University Park, PA

    Brauer, G
    Group Leader, Institut für Ionenstrahlphysik und Materialforschung, Forschungzentrum Rossendorf, Dresden,

    Böhmert, J
    Group Leader, Institut für Sicherheitsforschung, Forschungzentrum Rossendorf, Dresden,


    Paper ID: STP10537S

    Committee/Subcommittee: E10.07

    DOI: 10.1520/STP10537S


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