Ab-initio study of long-period superstructures and anti-phase boundaries in Al-rich γ-TiAl (L10)-based alloys

P. S. Ghosh, A. Arya, U. D. Kulkarni, G. K. Dey, Satoshi Hata, T. Nakano, K. Hagihara, Hideharu Nakashima

研究成果: ジャーナルへの寄稿記事

3 引用 (Scopus)

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In this work, we report first-principles investigation of structural stability of all experimentally observed ordered long-period superstructures (LPSs), viz., r-Al2Ti, h-Al2Ti, Al5Ti 3 along with Al5Ti3′, Al 11Ti7 and Al3Ti2 LPSs, which are observed only as short-range ordered clusters at nanoscale level in Al-rich TiAl-based alloys. We adopt a procedure based on space-filling tiling arrangement of ordered Ti2Al, Ti3Al, Ti4Al motifs and their combination along with a symmetry analysis programme to determine the unit cell and the crystallographic information of Al 5Ti3′, Al11Ti7 and Al 3Ti2 LPSs in terms of L10 fcc unit cell. First-principles calculations are performed to further refine these crystallographic parameters (Wyckoff positions and lattice parameters) obtained from the above procedure. Moreover, it is found that the family of five LPSs have subgroup-supergroup relationships with γ-TiAl (Sp. gr. P4/mmm) and among themselves. Further, we find the inherent stability of r-Al2Ti + γ-TiAl and 2Al5Ti3 + γ-TiAl phase mixtures at 0 K compared to isomolecular Al3Ti2 and Al 11Ti7 LPSs at their respective concentrations. The calculations of single-crystal elastic constants of Al5Ti 3, Al11Ti7, Al3Ti2 and Al5Ti3′ LPSs show all these four structures are mechanically stable. We also calculate antiphase boundary (APB) formation energies for two types of APBs, viz., type-A and type-C in ordered Al 5Ti3 LPS using the supercell approach. The relaxed APB energies for type-A and type-C APBs are 15.44 and 124.16 mJ/m2, respectively.

元の言語英語
ページ(範囲)1202-1218
ページ数17
ジャーナルPhilosophical Magazine
94
発行部数11
DOI
出版物ステータス出版済み - 4 13 2014

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antiphase boundaries
structural stability
energy of formation
subgroups
cells
lattice parameters
elastic properties
single crystals
symmetry
energy

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

これを引用

Ab-initio study of long-period superstructures and anti-phase boundaries in Al-rich γ-TiAl (L10)-based alloys. / Ghosh, P. S.; Arya, A.; Kulkarni, U. D.; Dey, G. K.; Hata, Satoshi; Nakano, T.; Hagihara, K.; Nakashima, Hideharu.

:: Philosophical Magazine, 巻 94, 番号 11, 13.04.2014, p. 1202-1218.

研究成果: ジャーナルへの寄稿記事

Ghosh, P. S. ; Arya, A. ; Kulkarni, U. D. ; Dey, G. K. ; Hata, Satoshi ; Nakano, T. ; Hagihara, K. ; Nakashima, Hideharu. / Ab-initio study of long-period superstructures and anti-phase boundaries in Al-rich γ-TiAl (L10)-based alloys. :: Philosophical Magazine. 2014 ; 巻 94, 番号 11. pp. 1202-1218.
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abstract = "In this work, we report first-principles investigation of structural stability of all experimentally observed ordered long-period superstructures (LPSs), viz., r-Al2Ti, h-Al2Ti, Al5Ti 3 along with Al5Ti3′, Al 11Ti7 and Al3Ti2 LPSs, which are observed only as short-range ordered clusters at nanoscale level in Al-rich TiAl-based alloys. We adopt a procedure based on space-filling tiling arrangement of ordered Ti2Al, Ti3Al, Ti4Al motifs and their combination along with a symmetry analysis programme to determine the unit cell and the crystallographic information of Al 5Ti3′, Al11Ti7 and Al 3Ti2 LPSs in terms of L10 fcc unit cell. First-principles calculations are performed to further refine these crystallographic parameters (Wyckoff positions and lattice parameters) obtained from the above procedure. Moreover, it is found that the family of five LPSs have subgroup-supergroup relationships with γ-TiAl (Sp. gr. P4/mmm) and among themselves. Further, we find the inherent stability of r-Al2Ti + γ-TiAl and 2Al5Ti3 + γ-TiAl phase mixtures at 0 K compared to isomolecular Al3Ti2 and Al 11Ti7 LPSs at their respective concentrations. The calculations of single-crystal elastic constants of Al5Ti 3, Al11Ti7, Al3Ti2 and Al5Ti3′ LPSs show all these four structures are mechanically stable. We also calculate antiphase boundary (APB) formation energies for two types of APBs, viz., type-A and type-C in ordered Al 5Ti3 LPS using the supercell approach. The relaxed APB energies for type-A and type-C APBs are 15.44 and 124.16 mJ/m2, respectively.",
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T1 - Ab-initio study of long-period superstructures and anti-phase boundaries in Al-rich γ-TiAl (L10)-based alloys

AU - Ghosh, P. S.

AU - Arya, A.

AU - Kulkarni, U. D.

AU - Dey, G. K.

AU - Hata, Satoshi

AU - Nakano, T.

AU - Hagihara, K.

AU - Nakashima, Hideharu

PY - 2014/4/13

Y1 - 2014/4/13

N2 - In this work, we report first-principles investigation of structural stability of all experimentally observed ordered long-period superstructures (LPSs), viz., r-Al2Ti, h-Al2Ti, Al5Ti 3 along with Al5Ti3′, Al 11Ti7 and Al3Ti2 LPSs, which are observed only as short-range ordered clusters at nanoscale level in Al-rich TiAl-based alloys. We adopt a procedure based on space-filling tiling arrangement of ordered Ti2Al, Ti3Al, Ti4Al motifs and their combination along with a symmetry analysis programme to determine the unit cell and the crystallographic information of Al 5Ti3′, Al11Ti7 and Al 3Ti2 LPSs in terms of L10 fcc unit cell. First-principles calculations are performed to further refine these crystallographic parameters (Wyckoff positions and lattice parameters) obtained from the above procedure. Moreover, it is found that the family of five LPSs have subgroup-supergroup relationships with γ-TiAl (Sp. gr. P4/mmm) and among themselves. Further, we find the inherent stability of r-Al2Ti + γ-TiAl and 2Al5Ti3 + γ-TiAl phase mixtures at 0 K compared to isomolecular Al3Ti2 and Al 11Ti7 LPSs at their respective concentrations. The calculations of single-crystal elastic constants of Al5Ti 3, Al11Ti7, Al3Ti2 and Al5Ti3′ LPSs show all these four structures are mechanically stable. We also calculate antiphase boundary (APB) formation energies for two types of APBs, viz., type-A and type-C in ordered Al 5Ti3 LPS using the supercell approach. The relaxed APB energies for type-A and type-C APBs are 15.44 and 124.16 mJ/m2, respectively.

AB - In this work, we report first-principles investigation of structural stability of all experimentally observed ordered long-period superstructures (LPSs), viz., r-Al2Ti, h-Al2Ti, Al5Ti 3 along with Al5Ti3′, Al 11Ti7 and Al3Ti2 LPSs, which are observed only as short-range ordered clusters at nanoscale level in Al-rich TiAl-based alloys. We adopt a procedure based on space-filling tiling arrangement of ordered Ti2Al, Ti3Al, Ti4Al motifs and their combination along with a symmetry analysis programme to determine the unit cell and the crystallographic information of Al 5Ti3′, Al11Ti7 and Al 3Ti2 LPSs in terms of L10 fcc unit cell. First-principles calculations are performed to further refine these crystallographic parameters (Wyckoff positions and lattice parameters) obtained from the above procedure. Moreover, it is found that the family of five LPSs have subgroup-supergroup relationships with γ-TiAl (Sp. gr. P4/mmm) and among themselves. Further, we find the inherent stability of r-Al2Ti + γ-TiAl and 2Al5Ti3 + γ-TiAl phase mixtures at 0 K compared to isomolecular Al3Ti2 and Al 11Ti7 LPSs at their respective concentrations. The calculations of single-crystal elastic constants of Al5Ti 3, Al11Ti7, Al3Ti2 and Al5Ti3′ LPSs show all these four structures are mechanically stable. We also calculate antiphase boundary (APB) formation energies for two types of APBs, viz., type-A and type-C in ordered Al 5Ti3 LPS using the supercell approach. The relaxed APB energies for type-A and type-C APBs are 15.44 and 124.16 mJ/m2, respectively.

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