STP782: The Effect of Preimplanted Helium on the Microstructure of Neutron Irradiated Nb, Nb-1%Zr and Nb-1%Zr-0.4%Mo

    van Witzenburg, W
    Netherlands Energy Research Foundation, ECN, Petten,

    van Tilborg, PJ
    Netherlands Energy Research Foundation, ECN, Petten,

    Mastenbroek, A
    Netherlands Energy Research Foundation, ECN, Petten,

    Elen, JD
    Netherlands Energy Research Foundation, ECN, Petten,

    Pages: 9    Published: Jan 1982


    Abstract

    The effect of preimplanted helium on the microstructure of neutron irradiated pure niobium and two dilute niobium alloys, Nb-1%Zr and Nb-1%Zr-0.4%Mo, was investigated by electron microscopy. Helium was implanted in the materials by means of a cyclotron with α-particles of 35 MeV at specimen temperatures of 420 K. The helium content ranges from 10–1000 at. ppm. Helium-containing and helium-free specimens were irradiated with neutrons at 940 K to 1.4 × 1025 and 4.8 × 1025n.m−2 (E > 0.1 MeV). Preimplantation with helium had essentially no effect on cavity size, concentration and volume fraction in Nb. The volume fraction of cavities in the alloys, however, is larger with helium. The increase is due to a larger cavity concentration in Nb-Zr. In the Nb-Zr-Mo alloy cavities formed in the helium-containing specimens only.

    Keywords:

    Niobium, radiation effects, helium, microstructure, cavities, voids, electron microscopy


    Paper ID: STP34349S

    Committee/Subcommittee: E10.07

    DOI: 10.1520/STP34349S


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