Microstructure/mechanical property relationship in a DS Cast Ni3Al-base alloy

  • Y. F. Han
  • Y. M. Wang
  • M. C. Chaturvedi
Materials Design


A Ni-Al-Mo directionally solidified (DS) casting γ-base superalloy, with the chemical composition (wt%) 7.5 to 8.5% Ni, 10 to 14% Al, Mo ≤0.15% B, has been developed for advanced gas turbine blades and vanes. The mechanical properties of this alloy have been determined by tensile tests at room temperature and in the temperature range 700 to 1000 °C and by stress-rupture tests in the temperature range 760 to 1100 °C. The microstructures of the as-cast and homogenized specimens and of specimens after creep de-formation at 1000 to 1100 °C have been examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and optical microscopy techniques. The results show that this alloy has a high yield strength from room temperature up to 1100 °C, excellent creep resistance at temperatures up to 1100 °C, as well as a lower density and higher melting point than currently available nickel superal-loys. The microstructural observations and analysis indicate that the superior mechanical properties of this alloy may be attributed to solid solution hardening by the large molybdenum addition, second-phase strengthening by y phase and other minor phases that precipitate in various temperature ranges, the for-mation of a γ raft structure during creep, and to the existence of high-density misfit dislocation networks at γ / γ interface areas due to a high value of γ / γ misfit.


creep microstructures misfit dislocations N13AI strengthening mechanism yield strength 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    K. Aoki and O. Izume,.J. Jpn. lint. Met., Vol 43. 1979, p I190CrossRefGoogle Scholar
  2. 2.
    S.M. Copley and B.H. Kear.Trans. AIME, Vol 239, 1967, p 997Google Scholar
  3. 3.
    D.H. Maxwell,Met. Eng. Quart.. Vol 10. Nov 1970, p 42Google Scholar
  4. 4.
    S. Chakravorty and D.R.F. West.Met. TechnoL. Oct 1980, p 414Google Scholar
  5. 5.
    C.T. Liu and V.K.Sikka, VOM. May 1986. p 19Google Scholar
  6. 6.
    C.H. Lee, T. Caulfield. and J.K. Tien.Scri. Metall.. Vol 2I.1987. p 925CrossRefGoogle Scholar
  7. 7.
    J.D. Deslefani,Adv. Mater. Process.. Vol 2, 1989. p 37Google Scholar
  8. 8.
    P.R. Munroeandl.Baker. Met. Mater.. Vol 4. 1988. p 435Google Scholar
  9. 9.
    S. Bellows, E.A. Schwarzkoph, and J.K. Tien,Metall. Trans. A, Vol 19, 1987, p 479CrossRefGoogle Scholar
  10. 10.
    Y.M. Wang, Ph.D. thesis. Institute of Aeronautical Materials, Beijing, China, 1991Google Scholar
  11. 11.
    A. Kelly and R.B. Nickolson,Strengthening Method in Crystals, Halsted Press Division, John Wiley & Sons, 1971, p 47Google Scholar
  12. 12.
    H. Brooks,Metal Interfaces. American Society for Metals. 1952. p20Google Scholar
  13. 13.
    M. Dollar and I.M. Bernstein,Superalloy 1988, Reichman et al., Ed., The Metallurgical Society, 1988, p 275Google Scholar
  14. 14.
    P. Nash, S. Fielding, and K.R.F. West,Met. Sci., Vol 17. Apr 1983, p 192CrossRefGoogle Scholar
  15. 15.
    Y. Mishima, S. Ochiai, M. Yodogawa, and T. Suzuki,Trans. Jpn. Inst. Met., Vol 27. 1986, p 41CrossRefGoogle Scholar
  16. 16.
    Y.F. Han and M.C. Chaturvedi, unpublished workGoogle Scholar
  17. 17.
    R.W. Guard and E.A. Smith,J. Inst. Met., Vol 88, 1959–60, p 283Google Scholar
  18. 18.
    V.Ya Markiv et al.,Akad USSR Met., Vol 5, 1969, p 180Google Scholar
  19. ba]19.
    L.I. Pryakhina et al., inDiagrammy Sostoyaniya Metallisch Sitstem, N.V. Aheev. Ed., Moscow, Nauka, 1971, p 112Google Scholar
  20. 20.
    D.B. Miracle, K.A. Lark, V. Srinivasan, and H.A. Lipsitt,Metall. Trans.A, Vol 15, 1984, p 481CrossRefGoogle Scholar
  21. 21.
    K. Wakashima, K. Higuchi, T. Suzuki, and S. Umekawa,Acta Metall, Vol 31, 1983, p 1937CrossRefGoogle Scholar
  22. 22.
    Hui Tian Wen et al.,.J. Jpn. Inst. Met., Vol 53, Oct 1989. p 1022- 1028CrossRefGoogle Scholar
  23. 23.
    D.D. Pearson, F.D. Lemkey, and B.H. Kear,Proc. 4th Int. Symp. Superalloys, American Society for Metals, 1980, p 513Google Scholar

Copyright information

© ASM International 1993

Authors and Affiliations

  • Y. F. Han
    • 1
  • Y. M. Wang
    • 1
  • M. C. Chaturvedi
    • 2
  1. 1.Institute or Aeronautical MaterialsBeijingChina
  2. 2.Department of Mechanical and Industrial EngineeringUniversity of ManitobaWinnipegCanada

Personalised recommendations