Irradiation induced vacamcy-Cu aggregations in Fe-Cu model alloys or reactor pressure vessel steels studied by positron annihilation

Yasuyoshi Nagai, Kazuma Takadate, Zheng Tang, Hideaki Ohkubo, Masayuki Hasegawa

Research output: Contribution to journalConference articlepeer-review

4 Citations (Scopus)

Abstract

Fe-Cu model alloys (0, 0.05, 0.15, 0.30 and 1.00 wt.%Cu) of Nuclear Reactor Pressure Vessel Steels irradiated by fast neutrons (8.3 × 10 18 n/cm2) at about 100°C are studied by positron annihilation spectroscopy, positron lifetime and coincidence Doppler broadening, in order to analyze the irradiation-induced vacancy-Cu aggregation. We have observed nanovoids (vacancy clusters) whose inner surfaces are covered by Cu atoms in not only high and medium Cu (0.15-1.0 wt.%) alloys but also low Cu (0.05 wt.%) alloys, The typical size of the nanovoids and the fraction of the covering with Cu on the inner surfaces depend on the Cu content. The dissociation of vacancies from the nanovoids by the post-irradiation isochronal annealing at about 400°C leads to the formation of the ultrafine Cu precipitates even for the Fe-0.05wt.%Cu alloy.

Original languageEnglish
Pages (from-to)590-602
Number of pages13
JournalASTM Special Technical Publication
Issue number1447
Publication statusPublished - 2004 Jan 1
EventEffects of Radiation on Materials: 21st International Symposium - Tucson, AZ, United States
Duration: 2002 Jun 182002 Jun 20

Keywords

  • Coincidence Doppler broadening
  • Fe-Cu model alloy
  • Neutron irradiation
  • Positron lifetime
  • Post-irradiation annealing
  • Vacancy-Cu aggregation

ASJC Scopus subject areas

  • Engineering(all)

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