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

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Abstract

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.

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References

  1. 1.

    K. Aoki and O. Izume,.J. Jpn. lint. Met., Vol 43. 1979, p I190

  2. 2.

    S.M. Copley and B.H. Kear.Trans. AIME, Vol 239, 1967, p 997

  3. 3.

    D.H. Maxwell,Met. Eng. Quart.. Vol 10. Nov 1970, p 42

  4. 4.

    S. Chakravorty and D.R.F. West.Met. TechnoL. Oct 1980, p 414

  5. 5.

    C.T. Liu and V.K.Sikka, VOM. May 1986. p 19

  6. 6.

    C.H. Lee, T. Caulfield. and J.K. Tien.Scri. Metall.. Vol 2I.1987. p 925

  7. 7.

    J.D. Deslefani,Adv. Mater. Process.. Vol 2, 1989. p 37

  8. 8.

    P.R. Munroeandl.Baker. Met. Mater.. Vol 4. 1988. p 435

  9. 9.

    S. Bellows, E.A. Schwarzkoph, and J.K. Tien,Metall. Trans. A, Vol 19, 1987, p 479

  10. 10.

    Y.M. Wang, Ph.D. thesis. Institute of Aeronautical Materials, Beijing, China, 1991

  11. 11.

    A. Kelly and R.B. Nickolson,Strengthening Method in Crystals, Halsted Press Division, John Wiley & Sons, 1971, p 47

  12. 12.

    H. Brooks,Metal Interfaces. American Society for Metals. 1952. p20

  13. 13.

    M. Dollar and I.M. Bernstein,Superalloy 1988, Reichman et al., Ed., The Metallurgical Society, 1988, p 275

  14. 14.

    P. Nash, S. Fielding, and K.R.F. West,Met. Sci., Vol 17. Apr 1983, p 192

  15. 15.

    Y. Mishima, S. Ochiai, M. Yodogawa, and T. Suzuki,Trans. Jpn. Inst. Met., Vol 27. 1986, p 41

  16. 16.

    Y.F. Han and M.C. Chaturvedi, unpublished work

  17. 17.

    R.W. Guard and E.A. Smith,J. Inst. Met., Vol 88, 1959–60, p 283

  18. 18.

    V.Ya Markiv et al.,Akad USSR Met., Vol 5, 1969, p 180

  19. ba]19.

    L.I. Pryakhina et al., inDiagrammy Sostoyaniya Metallisch Sitstem, N.V. Aheev. Ed., Moscow, Nauka, 1971, p 112

  20. 20.

    D.B. Miracle, K.A. Lark, V. Srinivasan, and H.A. Lipsitt,Metall. Trans.A, Vol 15, 1984, p 481

  21. 21.

    K. Wakashima, K. Higuchi, T. Suzuki, and S. Umekawa,Acta Metall, Vol 31, 1983, p 1937

  22. 22.

    Hui Tian Wen et al.,.J. Jpn. Inst. Met., Vol 53, Oct 1989. p 1022- 1028

  23. 23.

    D.D. Pearson, F.D. Lemkey, and B.H. Kear,Proc. 4th Int. Symp. Superalloys, American Society for Metals, 1980, p 513

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Han, Y.F., Wang, Y.M. & Chaturvedi, M.C. Microstructure/mechanical property relationship in a DS Cast Ni3Al-base alloy. JMEP 2, 589–596 (1993). https://doi.org/10.1007/BF02661745

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Keywords

  • creep
  • microstructures
  • misfit dislocations
  • N13AI
  • strengthening mechanism
  • yield strength