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High-temperature deformation mechanisms and constitutive equations for the oxide dispersion-strengthened superalloy MA 956

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Abstract

An experimental study of the constitutive response of the oxide dispersion-strengthened (ODS) superalloy MA 956, which consists of an Fe-Cr-Al matrix dispersion strengthened with yttria, has been performed.Single-crystal specimens of MA 956 having remarkably simple initial microstructures have been tested in compression in the temperature range of 900 °C to 1200 °C and in the axial strain-rate range of 1.8 x 10-4 s-1 to 10-2 s-1. The deformation response of the material has been examined by performing constant true strain-rate tests, strain-rate jump tests, and stress relaxation tests. The orientation dependence of the stress-strain response of the single crystals has been compensated for by determining the operative slip systems and resolving the stresses and strains accordingly. These experiments, together with electron-microscopic observations of deformed and quenched specimens, allow a number of conclusions to be drawn about the physics of particle strengthening in this simple ODS alloy at high temperatures. Further, drawing on this physical understanding, a set of phenomenological internal variable constitutive equations which model the high-temperature deformation behavior of this alloy is also developed. These equations reasonably well model not only the temperature and strain-rate sensitivity of the flow stress but also the strain-hardening behavior of the material.

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References

  1. L.M. Brown and R.K. Ham:Strengthening Methods in Crystals, A. Kelly and R.B. Nicholson, eds., Elsevier, Amsterdam, 1971, p. 9.

    Google Scholar 

  2. R.S.W. Shewfelt and L.M. Brown:Phil. Mag., 1977, vol. 35, pp. 945–62.

    Article  CAS  Google Scholar 

  3. R.W. Lund and W.D. Nix:Acta Metall., 1976, vol. 24, pp. 469–81.

    Article  CAS  Google Scholar 

  4. J.H. Hausselt and W.D. Nix:Acta Metall., 1977, vol. 25, pp. 1491–1502.

    Article  CAS  Google Scholar 

  5. J.D. Whittenberger:Metall. Trans. A, 1979, vol. 10A, pp. 1285–95.

    CAS  Google Scholar 

  6. J.D. Whittenberger:Metall. Trans. A, 1981, vol. 12A, pp. 845–51.

    Google Scholar 

  7. J.D. Whittenberger:Metall. Trans. A, 1984, vol. 15A, pp. 1753–62.

    CAS  Google Scholar 

  8. T.E. Howson, J.E. Stulga, and J.K. Tien:Metall. Trans. A, 1980, vol. 11A, pp. 1599–1607.

    CAS  Google Scholar 

  9. A.H. Cooper, V.C. Nardone, and J.K. Tien:Superalloys 1984: Proc. 5th Int. Conf. on Superalloys, TMS-AIME, Warrendale, PA, 1984, p. 357.

    Google Scholar 

  10. D.J. Srolovitz, R. Petkovic-Luton, and M.J. Luton:Scripta Metall., 1982, vol. 16, pp. 1401–06.

    Article  Google Scholar 

  11. S.M. Allen:Phil. Mag. A, 1981, vol. 43 (2), pp. 325–35.

    Article  CAS  Google Scholar 

  12. M. Haghi: M.S. Thesis, Massachusetts Institute of Technology, Cambridge, MA, 1986.

    Google Scholar 

  13. L. Anand:J. Eng. Mater. Technol., 1982, vol. 104, pp. 12–17.

    Article  Google Scholar 

  14. S.B. Brown, K.H. Kim, and L. Anand:Int. J. Plas., 1989, vol. 5, pp. 95–130.

    Article  Google Scholar 

  15. E.E. Underwood:Quantitative Stereology, Addison-Wesley Publishing Company, Reading, MA, 1970, pp. 172–78.

    Google Scholar 

  16. E. Artz and M.F. Ashby:Scripta Metall., 1982, vol. 16, pp. 1285–90.

    Article  Google Scholar 

  17. D.J. Srolovitz, M.J. Luton, R. Petkovic-Luton, D.M. Barnett, and W.D. Nix:Acta Metall., 1984, vol. 32, pp. 1079–88.

    Article  CAS  Google Scholar 

  18. J.H. Schröder and E. Artz:Scripta Metall., 1985, vol. 19, pp. 1129–34.

    Article  Google Scholar 

  19. E. Artz and D.S. Wilkinson:Acta Metall., 1986, vol. 34, pp. 1893–98.

    Article  Google Scholar 

  20. P.B. Hirsch and F.J. Humphreys:Physics of Strength and Plas ticity, A.S. Argon, ed., MIT Press, Cambridge, MA, 1969, pp. 189–216.

    Google Scholar 

  21. J.P. Hirth and J. Lothe:Theory of Dislocations, John Wiley & Sons, Inc., New York, NY, 1982, p. 263.

    Google Scholar 

  22. M.F. Ashby:Physics of Strength and Plasticity, A.S. Argon, ed., MIT Press, Cambridge, MA, 1969, pp. 113–31.

    Google Scholar 

  23. J.W. Martin:Micromechanisms in Particle Hardened Alloys, Cambridge University Press, Cambridge, 1980, p. 44.

    Google Scholar 

  24. H.J. Frost and M.F. Ashby:Deformation-Mechanism Maps: the Plasticity and Creep of Metals and Ceramics, Pergamon Press, 1982.

  25. W.R. Manning and O. Hunter:J. Am. Chem. Soc., 1969, vol. 52, pp. 492–96.

    CAS  Google Scholar 

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Authors and Affiliations

  1. Department of Mechanical Engineering, Massachusetts Institute of Technology, 02139, Cambridge, MA

    M. Haghi (Graduate Student) & L. Anand (Associate Professor)

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  1. M. Haghi
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  2. L. Anand
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Haghi, M., Anand, L. High-temperature deformation mechanisms and constitutive equations for the oxide dispersion-strengthened superalloy MA 956. Metall Trans A 21, 353–364 (1990). https://doi.org/10.1007/BF02782415

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