Determination of vacancy concentration and defect structure in the B2 type NiAl {beta}-phase alloys

Journal Article · Mon Jan 15 04:00:00 EST 1996 · Scripta Materialia

DOI:https://doi.org/10.1016/1359-6462(95)00514-5· OSTI ID:186796

Kogachi, M; Tanahashi, T ^[1]; Shirai, Y; Yamaguchi, M ^[2]

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1. Univ. of Osaka Prefecture, Sakai (Japan)
2. Kyoto Univ. (Japan). Dept. of Materials Science and Engineering

The B2 type NiAl {beta}-phase alloys exhibit a complex type of point defects as the constitutional defect in off-stoichiometric composition regions. This was first established by Bradley and Taylor from the measurements of density and lattice constant. Their proposed defect structure model, the BT model, is that, on the Ni-rich side of stoichiometry the Ni antistructure defects, the Ni-ASD, resulting from substitution of the excess of Ni atoms on the Al-site which is the lattice site assigned to Al atoms, are formed, whereas instead of formation of the Al-ASD, the vacancies on the Ni-site, the Ni-vacancies, are created on the Al-rich side. In this paper which is concerned with the defect structure appearing in the NiAl {beta}-phase, the authors report the results of density measurements by the use of powdered samples instead of bulk material and the results of X-ray analyses performed for these samples based on their own density data.

• OSTI ID: 186796
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 2 Vol. 34; ISSN 1359-6462; ISSN XZ503X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CRYSTAL LATTICES
CRYSTAL MODELS
DENSITY
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
NICKEL ALLOYS
POINT DEFECTS
POWDERS
STOICHIOMETRY
VACANCIES
X-RAY DIFFRACTION