Bulk and defect properties of ordered intermetallics [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 1993.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 10 pages : digital, PDF file
- Additional Creators:
- Oak Ridge National Laboratory
United States. Department of Energy
United States. Department of Energy. Office of Scientific and Technical Information
- First-principles calculations based on the local-density-functional theory have been used to investigate the factors governing strength of ordered intermetallic alloys. Unlike Ni₃Al, calculated elastic constants and shear fault energies indicate anomalous yield strength behavior is not likely to occur in Ni₃Si. This suggests the inadequacy of cross-slip-pinning model to explain the strength anomaly in the L1₂ structure. For strongly ordered NiAl, the defect structure is dominated by two types of defects -- monovacancies on the Ni sites and substitutional antisite defects on the Al sites. By contrast, for Ni₃Al, absence of structural vacancies and deviations from stoichiometry are accommodated by substitutional antisite defects on both sublattices. Intrinsic strengthening mechanisms in TiAl are discussed in terms of calculated elastic constants and shear fault energies. Because of reduced fault energies at the γ/α₂ interface, slip and twinning contribute significantly to high shear deformation of the lamellar structure.
- Published through SciTech Connect.
Fall meeting of the Minerals, Metals and Materials Society: physical metallurgy and materials,Pittsburgh, PA (United States),17-21 Oct 1993.
Fu, C.L.; Yoo, M.H.
- Funding Information:
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