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Influence of molybdenum on the creep properties of nickel-base superalloy single crystals

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Abstract

The influence of Mo on the creep properties of single crystals of a model nickel-base superalloy has been investigated. The Mo content was systematically varied from 9.8 to 14.6 wt pet in an alloy series based on Ni-6 wt pet Al-6 wt pet Ta. The optimum initial γ-γ′ microstructure for raft development and creep strength was produced in each alloy prior to testing. The creep lives at 982 °C and 234 MPa exhibited a steep peak as a function of Mo content, with the maximum in life occurring at about 14.0 wt pet Mo. Deviations of less than 1 wt pet Mo from the optimum composition resulted in an order of magnitude drop in properties. As the Mo content was increased from 9.8 to 14.0 wt pct, the magnitude of lattice mismatch significantly increased, which was believed to be beneficial because of stronger γ-γ′ interfaces. As the Mo content was increased further from 14.0 to 14.6 w/o, the mechanical properties degraded because of the precipitation of a deleterious third phase. The results suggest that small variations in refractory metal content and initial gg′ size can have profound effects on mechanical properties. Hence, composition ranges and microstructures for the attainment of optimum mechanical properties may be somewhat limited and require close process control.

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References

  1. M.V. Nathal:Metall. Trans. A, 1987, vol. 18A, pp. 1961–70.

    CAS  Google Scholar 

  2. R.A. MacKay and L.J. Ebert: inProc. 5th Int. Symp. on Superalloys, M. Gell, C.S. Kortovich, R.H. Bricknell, W.B. Kent, and J.F. Radavich, eds., AIME, New York, NY, 1984, pp. 135–44.

    Google Scholar 

  3. R.A. MacKay and M.V. Nathal: inMiCon 86: Optimization of Processing, Properties, and Service Performance Through Microstructural Control, ASTM STP 979, B.L. Bramfitt, R.C. Benn, C.R. Brinkman, and G.F. Vander Voort, eds., ASTM, Philadelphia, PA, 1988, pp. 202–21.

    Google Scholar 

  4. D.D. Pearson, B.H. Kear, and F.D. Lemkey: inCreep and Fracture of Engineering Materials and Structures, B. Wilshire and D.R.J. Owen, eds., Pineridge Press Ltd., Swansea, United Kingdom, 1981, pp. 213–33.

    Google Scholar 

  5. D.D. Pearson, F.D. Lemkey, and B.H. Kear: inProc. 4th Int. Symp. on Superalloys, J.K. Tien, S.T. Wlodek, H. Morrow, M. Gell, and G.E. Maurer, eds., ASM, Metals Park, OH, 1980, pp. 513–19.

    Google Scholar 

  6. P. Caron and T. Khan:Mater. Sci. Eng., 1983, vol.61, pp. 173–84.

    Article  Google Scholar 

  7. A.F. Giamei, D.D. Pearson, and D.L. Anton: inHigh-Temperature Ordered Intermetallic Alloys, C.C. Koch, C.T. Liu, and N.S. Stoloff, eds., MRS, Pittsburgh, PA, 1985, vol. 39, pp. 293–308.

    Google Scholar 

  8. M.V. Nathal, R.A. MacKay, and R.G. Garlick:Mater. Sci. Eng., 1985, vol. 75, pp. 195–205.

    Article  CAS  Google Scholar 

  9. M.V. Nathal, R.A. MacKay, and R.G. Garlick:Scripta Metall., 1988, vol. 22, pp. 1421–24.

    Article  CAS  Google Scholar 

  10. R.A. MacKay and M.V. Nathal:Acta Metall., 1990, in press.

  11. D. Hull, M.V. Nathal, and R.A. MacKay: NASA-Lewis Research Center, Cleveland, OH, unpublished research, 1989.

  12. R.A. MacKay and L.J. Ebert:Scripta Metall., 1983, vol. 17, pp. 1217–22.

    Article  CAS  Google Scholar 

  13. W.T. Loomis, J.W. Freeman, and D.L. Sponseller:Metall. Trans., 1972, vol. 3, pp. 989–1000.

    Article  CAS  Google Scholar 

  14. M.V. Nathal and R.A. MacKay:Mater. Sci. Eng., 1987, vol. 85, pp. 127–38.

    Article  CAS  Google Scholar 

  15. M.V. Nathal and L.J. Ebert:Metall. Trans. A, 1985, vol. 16A, pp. 1849–62.

    CAS  Google Scholar 

  16. T.P. Gabb, S.L. Draper, D.R. Hull, R.A. MacKay, and M.V. Nathal:Mater. Sic. Eng., 1989, vol. A118, pp. 59–69.

    Article  CAS  Google Scholar 

  17. T.C. Tearney, Jr. and N.J. Grant:Metall. Trans. A, 1982, vol. 13A, pp. 1827–36.

    Google Scholar 

  18. K.M. Delargy and G.D.W. Smith:Metall. Trans. A, 1983, vol. 14A, pp. 1771–83.

    CAS  Google Scholar 

  19. D. Blavette and A. Bostel:Acta Metall., 1984, vol. 32, pp. 811–16.

    Article  CAS  Google Scholar 

  20. A.A. Hopgood and J.W. Martin:Mater. Sci. Eng., 1986, vol. 82, pp. 27–36.

    Article  CAS  Google Scholar 

  21. R.A. Ricks, A.J. Porter, and R.C. Ecob:Acta Metall., 1983, vol. 31, pp. 43–53.

    Article  CAS  Google Scholar 

  22. D. Blavette, P. Caron, and T. Khan:Scripta Metall., 1986, vol. 20, pp. 1395–1400.

    Article  CAS  Google Scholar 

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Authors and Affiliations

  1. Materials Division, NASA-Lewis Research Center, 44135, Cleveland, OH

    R. A. MacKay (Materials Scientist) & M. V. Nathal (Deputy Branch Chief)

  2. United Technologies Research Center, 06108, East Hartford, CT

    D. D. Pearson (Senior Materials Scientist)

Authors
  1. R. A. MacKay
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  2. M. V. Nathal
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  3. D. D. Pearson
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MacKay, R.A., Nathal, M.V. & Pearson, D.D. Influence of molybdenum on the creep properties of nickel-base superalloy single crystals. Metall Trans A 21, 381–388 (1990). https://doi.org/10.1007/BF02782418

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  • DOI: https://doi.org/10.1007/BF02782418

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