Skip to main content
Log in

Structure Refinement by a Liquid Metal Cooling Solidification Process for Single-Crystal Nickel-Base Superalloys

  • Published:
Metallurgical and Materials Transactions A Aims and scope Submit manuscript

Abstract

Single crystals of a nickel-base superalloy were directionally solidified (DS) over a range of cooling rates to evaluate the benefits of a new high thermal gradient solidification process. Solidification experiments were conducted on cylindrical bars with a liquid-metal-enhanced cooling process. This higher gradient casting process was evaluated for the degree of structure refinement, microstructural variability, and porosity distributions. Cylindrical bars of 1.6-cm diameter were solidified at rates between 8.4 and 21.2 mm/min using a tin-based, liquid metal cooling (LMC) technique and at a rate of 3.4 mm/min with a conventional Bridgman process. The LMC process produced a refined microstructure with average primary dendrite arm spacing (PDAS) and secondary dendrite arm spacing (SDAS) values as low as 164 and 25 μm, respectively, for the bar geometry evaluated. An optimum intermediate withdrawal velocity of 12.7 mm/min produced up to a 50 and 60 pct refinement in PDAS and SDAS, respectively. Further increases in withdrawal velocity produced smaller SDAS and pore sizes, but undesirable grain boundaries and excessive secondary dendrite arm growth. Voronoi tessellation methods were used to examine the extremes of the dendrite arm spacings in comparison to the average measurements, the packing of dendrites, and the correlation of porosity size and location with the dendrite structure. A simple expression for prediction of the maximum pore size is developed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17

Similar content being viewed by others

Notes

  1. RENÉ is a trademark of the General Electric Company, Fairfield, CT.

References

  1. T.M. Pollock and S. Tin: J. Prop. Power, 2006, vol. 22, pp. 361–74.

    Article  CAS  Google Scholar 

  2. R.C. Reed: in The Superalloys: Fundamentals and Applications, Cambridge University Press, Cambridge, 2006, pp. 121–87.

  3. M. Gell, C.P. Sullivan, and F.L Ver Snyder: in Solidification Technology, J.J. Burke, M.C. Flemings, and A.E. Gorum, eds., Brook Hill, Chestnut Hill, MA, 1974, pp. 141–64.

    Google Scholar 

  4. M. Konter, E. Kats, and N. Hofmann: in Superalloys 2000, T.M. Pollock, R.D. Kissinger, R.R. Bowman, K.A. Green, M. McLean, S.L. Olson, and J.J. Schirra, eds., TMS, Warrendale, PA, 2000, pp. 189–200.

    Google Scholar 

  5. L. Liu, T.W. Huang, J. Zhang, and H.Z. Fu: Mater. Lett., 2007, vol. 61, pp. 227–30.

    Article  CAS  Google Scholar 

  6. F. Hugo, U. Betz, J. Ren, S.-C. Huang, J.A. Bondarenko, and V. Gerasimov: Int. Symp. on Liquid Metal Processing and Casting, A. Mitchell, L. Ridgway, and M. Baldwin, eds., AVS, New York, NY, 1999, pp. 16–30.

    Google Scholar 

  7. A.J. Elliott and T.M. Pollock: Metall. Mater. Trans. A, 2007, vol. 38A, pp. 871–82.

    Article  CAS  Google Scholar 

  8. A.J. Elliott, S. Tin, W.T. King, S.-C. Huang, M.F.X. Gigliotti, and T.M. Pollock: Metall. Mater. Trans. A, 2004, vol. 35A, pp. 3221–31.

    Article  CAS  Google Scholar 

  9. J.G. Tschinkel, A.F. Giamei, and B.H. Kearn: U.S. Patent No. 3,763,926, 1973.

  10. T.J. Fitzgerald and R.F. Singer: Metall. Mater. Trans. A, 1997, vol. 28A, pp. 1377–83.

    Article  CAS  Google Scholar 

  11. D.G. McCartney and J.D. Hunt: Acta Metall., 1981, vol. 29, pp. 1851–63.

    Article  CAS  Google Scholar 

  12. R.E. Spear and G.R. Gardner: AFS, 1963, vol. 71, pp. 209–15.

    Google Scholar 

  13. M. Karavelas: in CGAL User and Reference Manual, 3.3 ed., CGAL Editorial Board, ed., 2007. Available from: http://www.cgal.org.

  14. The MathWorks Inc., Natick, MA.

  15. W.S. Rasband: ImageJ, US National Institutes of Health, Bethesda, MA, 1997–2007, available from: http://rsb.info.nih.gov/ij/.

  16. Y. Murakami and M. Endo: Int. J. Fatigue, 1994, vol. 16, pp. 163–82.

    Article  CAS  Google Scholar 

  17. C. Brundidge, J.D. Miller, and T.M. Pollock: Metall. Mater. Trans. A, 2011, vol. 42A, pp. 2723–32.

    Article  Google Scholar 

  18. W. Wang, P.D. Lee, and M. Mclean: Acta Mater., 2003, vol. 51, pp. 2971–87.

    Article  CAS  Google Scholar 

  19. D. Ma: Metall. Mater. Trans. B, 2002, vol. 33B, pp. 223–33.

    Article  CAS  Google Scholar 

  20. D.R. Poirier, K. Yeum, and A. Maples: Metall. Mater. Trans. A, 1987, vol. 18A, pp. 1979–87.

    CAS  Google Scholar 

  21. H.W. Whitesell and R.A. Overfelt: Mater. Sci. Eng. A, 2001, vol. A318, pp. 264–76.

    CAS  Google Scholar 

  22. J. Madison, J. Spowart, D. Rowenhorst, L.K. Aagesen, K. Thornton, and T.M. Pollock: Acta Mater., 2010, vol. 58, pp. 2864–75.

    Article  CAS  Google Scholar 

  23. J.C. Heinrich and D.R. Poirier: C.R. Mecanique, 2004, vol. 332, pp. 429–45.

    Article  Google Scholar 

Download references

Acknowledgments

The authors acknowledge the assistance of C.J. Torbet. The funding provided by General Electric Aviation (GE-USA Program) is also gratefully acknowledged.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to C. L. Brundidge.

Additional information

Manuscript submitted January 17, 2011.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Brundidge, C.L., van Drasek, D., Wang, B. et al. Structure Refinement by a Liquid Metal Cooling Solidification Process for Single-Crystal Nickel-Base Superalloys. Metall Mater Trans A 43, 965–976 (2012). https://doi.org/10.1007/s11661-011-0920-8

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11661-011-0920-8

Keywords

Navigation