Hardening by point defects in neutron irradiated AIN and sic.

Takayoshi Iseki, Mitsuharu Tezuka, Chang sam Kim, Tetsuya Suzuki, Hisayuki Suematsu, Toyohiko Yano

Research output: Contribution to journalArticle

Abstract

Pressureless-sintered AlN and hot-pressed, pressureless-sintered and reaction-bonded SiC were neutron irradiated at temperatures between 100 and 785°C up to a fluence of 5.2 × 1024 n/m2. The hardness was increased by up to 51% in AlN and 84% in SiC, The hardness decreased after annealing at temperatures around the irradiation temperature. At the same temperatures, the macroscopic length, which was increased by irradiation, also began to decrease. The hardness and length were almost recovered after 1,200~1,400°C annealing. Thus, hardening in irradiated AlN and SiC is controlled by the number of point defects, or, more precisely, by the strain caused by small point defect clusters which pin down dislocation movement. Dislocation loops were still observed in some samples after 1,400°C annealing while the hardness was almost recovered to that in the unirradiated state. Thus, the existence of dislocation loops is not grounds for hardening in irradiated AlN and SiC.

Original languageEnglish
Pages (from-to)68-77
Number of pages10
JournalJournal of Nuclear Science and Technology
Volume30
Issue number1
DOIs
Publication statusPublished - 1993
Externally publishedYes

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Keywords

  • aluminium nitrides
  • annealing
  • defect cluster
  • dislocation
  • dislocation loop
  • hardening
  • neutron irradiation
  • point defects
  • silicon carbides
  • swelling
  • temperature dependence
  • Vickers hardness

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering

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