Deformation behavior of B2 type aluminides; FeAl and NiAl
- Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.
In this paper first-principles calculation of the elastic constants, shear fault energies, cleavage strength, and bonding charge density of Ni Al and FeAl are presented. For NiAl, we find that the dissociation of {l angle}111{r angle} superdislocations into partial dislocations is unlikely, because of a high antiphase boundary (APB) energy and a weak repulsive elastic force between partial dislocations. The APB energy of FeAl is found to be highly anisotropic with respect to different slip planes. FeAl has a high ideal cleavage strength as a result of the directional d-bond formation at the Fe sites. The strong ordering behavior of NoAl is explained in terms of the repulsive interaction between Al atoms as a result of the Al-to-Ni charge transfer and the atomic size difference of Ni and Al. The active slip plane of {l brace}112{r brace} in FeAl at low temperatures is predicted on the basis of the anisotropic elastic coupling effect of non-glide stresses. The spontaneous glide decomposition of the {l angle}111{r angle} superdislocation in NiAl, which can be a source of {l angle}100{r angle} slip, is also discussed.
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 7238229
- Journal Information:
- Acta Metallurgica; (United States), Journal Name: Acta Metallurgica; (United States) Vol. 40:4; ISSN 0001-6160; ISSN AMETA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
664100 -- Theory of Electronic Structure of Atoms & Molecules-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
ATOM TRANSPORT
BINARY ALLOY SYSTEMS
CALCULATION METHODS
CHARGE DENSITY
DEFORMATION
ELASTICITY
FRACTURE MECHANICS
IRON ALLOYS
MECHANICAL PROPERTIES
MECHANICS
NEUTRAL-PARTICLE TRANSPORT
NICKEL ALLOYS
RADIATION TRANSPORT
SLIP VELOCITY
TENSILE PROPERTIES
VELOCITY