Advertisement

Study of phase equilibria in the Nb-Ti-Al system theoretical study: CVM calculation of the phase diagram of bcc Nb-Ti-Al

  • V. Chaumat
  • F. Moret
  • C. Colinet
Basic And Applied Research

Abstract

The cluster variation method (CVM) in the irregular tetrahedron approximation has been used to calculate the temperature and composition limits of the ordered-cubic-centered B2 phase field in the Nb-Ti-Al system. Results show that this B2 domain is large and particularly extended toward the Nb-rich compositions. The order-disorder B2 → A2 transition temperature and the occupation probabilities of sites of the B2 phase are strongly dependent on composition that is in agreement with experimental results [98Cha].

Keywords

Ternary Interaction Cluster Variation Method BBBA Irregular Tetrahedron Natural Iteration Method 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 74Kikl:.
    R. Kikuchi and C.M. Van Baal, Phase Diagrams of fcc and bcc Ordered Alloys, Scr. Metall., Vol 8, 1974, p 425–430CrossRefGoogle Scholar
  2. 74Kik2:.
    R. Kikuchi, Superposition Approximation and Natural Iteration Calculation in Cluster Variation Method, J. Chem. Phys., Vol 60, 1974, p 1071–1080CrossRefADSGoogle Scholar
  3. 88Ben:.
    L.A. Bendersky and W.J. Boettinger, Investigation of B2 and Related Phases in the Ti-Al-Nb Ternary System, High-Temperature Ordered Intermetallic Alloy III (Boston, MA), 29 Nov–1 Dec 1988, Symposium Proceedings, Vol 133, Materials Research Society, 1989, p 45–50Google Scholar
  4. 89Ack:.
    H. Ackermann, G. Inden, and R. Kikuchi, Tetrahedron Approximation of the Cluster Variation Method for bcc Alloys, Acta Metall. Mater., Vol 37, 1989, p 1–7CrossRefGoogle Scholar
  5. 89Per:.
    J.H. Perepezko, Y.A. Chang, L.E. Seitzman, J.C. Lin, N.R. Bonda, T.J. Jewett, and J.C. Mishurda, High Temperature Phase Stability in the Ti-AlNb System, High Temperature Aluminides and Intermetallics (Indianapolis, IN), 1–5 Oct 1989, The Minerals, Metals & Materials Society, 1990, p 19Google Scholar
  6. 90Hel:.
    A. Hellwig, “Experimental Research of the Constitution of the Aluminum-Titanium-Niobium System,” Thesis, University Dortmund, 1990 (in German)Google Scholar
  7. 92Kat:.
    U.R. Kattner and W.J. Boettinger, Thermodynamic Calculation of the Ternary Ti-Al-Nb System, Mater. Sci. Eng., Vol 152, 1992, p 9–17CrossRefGoogle Scholar
  8. 92Men:.
    E.S.K. Menon, P.R. Subramanian, and D.M. Dimiduk, Phase Equilibria in Niobium Rich Nb-Al-Ti Alloys, Scr. Metall. Mater., Vol 27, 1992, p 265–270CrossRefGoogle Scholar
  9. 93Nak:.
    S. Naka, M. Marty, G. Lapasset, and T. Khan, Complex B2 Aluminides of Refractory Metals: An Attempt to Explore Novel Alloy System, First International Symposium on Structural Intermetallics (Champion, PA), 26–30 Sept 1993, The Minerals, Metals & Materials Society, 1993, p 647–656Google Scholar
  10. 93Shy:.
    J. Shyue, D.H. Hou, S.C. Johnson, and H.L Fraser, Phase Stability, Deformation Mechanisms and Mechanical Properties of Nb-Al-Ti Alloys, First International Symposium on Structural Intermetallics (Champion, PA), 26–30 Sept 1993, The Minerals, Metals & Materials Society, 1993, p 631–635Google Scholar
  11. 94Kum:.
    S.G. Kumar, R.G. Reddy, and L. Brewer, Phase Equilibrium in Ti3Al-Nb Alloys at 1000°C, J. Phase Equilibria, Vol 15 (No. 3), 1994, p 279–284CrossRefGoogle Scholar
  12. 95Ast:.
    M. Asta, A. Ormeci, and J.M. Wills, First-Principles Study of Intermetallic Phase Stability in the Ternary Ti-Al-Nb Alloy System, High-Temperature Ordered Intermetallic Alloys VI (Boston, MA), 28 Nov–1 Dec 1994, Symposium Proceedings, Vol 364, Materials Research Society, 1995, p 157–162Google Scholar
  13. 95Nak:.
    S. Naka, M. Marty, M. Thomas, and T. Khan, Variation in the Degree of Order and Its Influence on Mechanical Behavior in Complex B2 Aluminides of Refractory Metals, Mater. Sci. Eng., Vol A192/193, 1995, p 69–76Google Scholar
  14. 95Rub:.
    G. Rubin and A. Finel, Application of First-Principles Methods to Binary and Ternary Alloy Phase Diagram Predictions, J. Phys., Condens. Matter., Vol 7, 1995, p 3139–3152CrossRefADSGoogle Scholar
  15. 95Sik:.
    T. Sikora, G. Hug, M. Jaouen, and A.M. Flank, EXAFS Study of the Local Atomic Order in Ti2AlX (X=Nb, Mo), J. Physique, Vol 4 (No. 2), 1996, p 15–20 (in French)Google Scholar
  16. 96Cha:.
    V. Chaumat-Jacob, “Phase Equilibria and Microstructures in Nb-Ti-Al Alloys Prepared by Mechanical Alloying,” Thesis, INPG, Grenoble, France, 1996, (in French)Google Scholar
  17. 96Col:.
    C. Colinet and V. Jacob, Effect of Ternary Interactions on the B2/A2 Phase Boundary in the Nb-Ti-Al System, J. d’Etudes Equil. Phases, 15–16 April 1996 (in French)Google Scholar
  18. 96Sad:.
    F.A. Sadi and C. Servant, Transformations during Continuous Cooling of the Ti4Al3Nb Alloy, J. Phys., Vol 4 (No. 2), 1996, p 241–246 (in French)Google Scholar
  19. 97Col:.
    C. Colinet, A. Pasturel, D. Nguyen Manh, D.G. Pettigor, and P. Miodownick, Phase-Stability Study of the Al-Nb System, Phys. Rev. B, Vol 56 (No. 2), 1997, p 552–565CrossRefADSGoogle Scholar
  20. 97Hou:.
    D.-H. Hou and H.L. Fraser, The Ordering Scheme in Nb Aluminides with the B2 Crystal Structure, Scr. Mater., Vol 36 (No. 6), 1997, p 617–623CrossRefGoogle Scholar
  21. 97Sad:.
    F.A. Sadi, “Contribution to the Study of the Al-Nb-Ti Phase Diagram near the AlNbTi2 and Al3NbTi4 Compounds,” Thesis, Université Paris, Orsay, France, 1997 (in French)Google Scholar
  22. 98Cha:.
    V. Chaumat, E. Ressouche, B. Ouladdiaf, P. Desré, and F. Moret, Experimental Study of Phase Equilibria in the Nb-Ti-Al System, Scr. Mater., (in press)Google Scholar

Copyright information

© ASM International 1999

Authors and Affiliations

  • V. Chaumat
    • 1
  • F. Moret
    • 1
  • C. Colinet
    • 2
  1. 1.CEA/CEREM/DEM—Service of Materials EngineeringGrenoble cedex 9France
  2. 2.ENSEEG. LTPCMSaint Martin d’HèresFrance

Personalised recommendations