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On the influence of grain morphology on creep deformation and damage mechanisms in directionally solidified and oxide dispersion strengthened superalloys

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Abstract

Directionally solidified (DS) and oxide dispersion strengthened (ODS) superalloys like CM 247 LC and MA 760 exhibit elongated macrograins. In uniaxial creep tests, the creep strength of such alloys in the direction of the longitudinal grains is higher than that of an equiaxed grain structure, because significantly less grain boundary (GB) segments are perpendicular to the axis of the applied stress. The present study investigates how creep in the longitudinal direction of these alloys is influenced (1) by deviations of individual grain orientations from the optimum growth direction during casting (CM 247 LC) and (2) by the spatial distribution of the small transverse GB segments (MA 760) for a given grain aspect ratio. In the case of creep ductile CM 247 LC, it was shown that if there is a large fraction of grains that are oriented for single slip, this results in higher creep rates and lower rupture times than if there is only a small fraction of such grains. The study of the influence of grain morphology on creep damage accumulation in the creep-brittle and notch-sensitive ODS alloy MA 760 showed that large scatter in creep rupture lives is related to (1) the stochastic nature of creep damage accumulation on transverse GB segments and (2) the spatial distribution of transverse GB segments. It is the combination of these two factors that results in increased scatter in rupture lives as compared to equiaxed fine grain structures.

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References

  1. F.L. Versnyder and M.E. Shank:Mater. Sci. Eng., 1970, vol. 6, pp. 213–47.

    Article  CAS  Google Scholar 

  2. M. McLean:Directionally Solidified Materials for High Temperature Service, The Metals Society, London, 1983.

    Google Scholar 

  3. G.H. Gessinger:Powder Metallurgy of Superalloys, Butterworth and Co., London, 1984.

    Google Scholar 

  4. P. Jongenburger: Ph.D. Thesis, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 1988.

    Google Scholar 

  5. J.J. Stephens: Ph.D. Thesis, Stanford University, 1984.

  6. P.N. Quested and S. Osgerby:Mater. Sci. Technol., 1986, vol. 2, pp. 461–75.

    CAS  Google Scholar 

  7. E. Arzt and R.F. Singer:Superalloys 1984, Proc. 5th Int. Symp. on Superalloys, Oct. 7–11, 1984, Seven Springs Mountain Resort, Champion, PA, M. Gell, C.S. Kortovich, R.H. Bricknell, W.B. Kent, and J.F. Radavich, TMS-AIME, Warrendale, PA, 1984.

    Google Scholar 

  8. B. deMestral and G. Eggeler:Prac. Metallogr., 1992, vol. 29, pp. 174–91.

    CAS  Google Scholar 

  9. H.J. Bunge:International Materials Reviews, 1987, vol. 32, pp. 265–91.

    CAS  Google Scholar 

  10. B. deMestral and G. Eggeler: Swiss Federal Institute of Technology, Lausanne, Switzerland, unpublished work, 1992.

  11. G. Jakobi: Diploma Thesis, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 1991.

    Google Scholar 

  12. B. deMestral, N. Merk, G. Eggeler: Final report of COST 501/II/WP5A, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 1993.

    Google Scholar 

  13. Gerald R. Leverant, Bernard H. Kear:Metall. Trans., 1970, vol. 1, pp. 491–98.

    CAS  Google Scholar 

  14. G.R. Leverant, B.H. Kear, and J.M. Oblak:Metall. Trans., 1973, vol. 4, pp. 355–62.

    CAS  Google Scholar 

  15. H. Riedel:Rupture at High Temperatures, Springer-Verlag, Berlin, 1987.

    Google Scholar 

  16. G.J.S. Higginbotham:Mater. Sci. Technol., 1986, vol. 2, pp. 442–60.

    Google Scholar 

  17. R.A. MacKay and R.D. Maier:Metall. Trans. A, 1982, vol. 13A, pp. 1747–54.

    Google Scholar 

  18. E. Schmid and W. Boas:Plasticity of Crystals, Hughes, London, 1950.

    Google Scholar 

  19. V. Guttmann and H. Fattori: Commission of the European Communities, Joint Research Centre Petten, unpublished results obtained within COST 501/II/WP1 (project CCR1), personal communication, 1992.

  20. N. Nilsvang and G. Eggeler:Pract. Metallogr., 1987, vol. 24, pp. 323–35.

    CAS  Google Scholar 

  21. G. Eggeler, J.C. Earthman, N. Nilsvang, and B. Ilschner:Acta Metall., 1989, vol. 37, pp. 49–60.

    Article  CAS  Google Scholar 

  22. G. Eggeler:Acta Metall. Mater., 1991, vol. 89, pp. 221–31.

    Google Scholar 

  23. M. Cans, B. deMestral, and G. Eggeler:Scripta Metall. Mater., 1994, vol. 30, pp. 107–12.

    Article  CAS  Google Scholar 

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Authors and Affiliations

  1. Fakultät für Maschinenbau, Institut für Werkstoffe, Ruhr-Universität Bochum, Institute of Materials, Ruhr-University, D-44780, Bochum, Germany

    B. DeMestral (Research Assistant) & G. Eggeler (Professor)

  2. Materials Technology Department, ABB Powder Generation Ltd., 5401, Baden, Switzerland

    H. -J. Klam (Materials Engineer)

Authors
  1. B. DeMestral
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  2. G. Eggeler
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  3. H. -J. Klam
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Additional information

This article is based on a presentation made at the “High Temperature Fracture Mechanisms in Advanced Materials” symposium as part of the 1994 Fall meeting of TMS, October 2-6, 1994, in Rosemont, Illinois, under the auspices of the ASM/SMD Flow and Fracture Committee.

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DeMestral, B., Eggeler, G. & Klam, H.J. On the influence of grain morphology on creep deformation and damage mechanisms in directionally solidified and oxide dispersion strengthened superalloys. Metall Mater Trans A 27, 879–890 (1996). https://doi.org/10.1007/BF02649755

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