Co diffusion in a B2-type ordered NiAl compound

Yoritoshi Minamino, Yuichiro Koizumi, Nobuhiro Tsuji, Toru Yamada

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Co diffusion in a B2-type ordered NiAl compound was investigated at seven compositions between 40.9 at%Al and 52.6 at%Al at five temperatures from 1423 K to 1623 K, using a diffusion couple method. The Co diffusion coefficients at each temperature have a minimum value at the stoichiometric composition, while their activation energies and pre-exponential factors reveal maximum values at this composition. The activation energies decrease gently with the Ni content in the Ni-rich side, but decrease steeply with the Al content in the Al-rich side. The interpretation of this behavior is discussed in terms of the diffusion mechanisms; the triple defect mechanism at stoichiometric composition, the antisite bridge mechanism in the Ni-rich side, and the next nearest neighbor jump mechanism with the structural Ni vacancies.

Original languageEnglish
Pages (from-to)67-74
Number of pages8
JournalNippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals
Volume66
Issue number2
DOIs
Publication statusPublished - 2002 Feb

Keywords

  • Activation energy
  • Antisite atom
  • Cobalt
  • Diffusion
  • Diffusion couple
  • Divacancy
  • Next nearest neighbor jump
  • Nickel aluminide
  • Ordering
  • Pre-exponential factor
  • Triple defects
  • Vacancy

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys
  • Materials Chemistry

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