Advertisement

Simulation and Experimental Study on the Directional Solidification Process of a Single-Crystal Superalloy Plate Casting

  • Runnan Wang
  • Qingyan XuEmail author
  • Baicheng Liu
Conference paper
First Online:
Part of the Springer Proceedings in Physics book series (SPPHY, volume 217)

Abstract

The directional solidification (DS) process and as-cast microstructure of a single-crystal (SX) plate casting were investigated through simulations and experiments. Simulations were conducted to optimize the directional solidification process. The mushy zone showed flat and concave morphology at the withdrawing rate of 3 and 6 mm/min, respectively. Based on the simulation results, the directional solidification experiment was performed at the withdrawing rate of 3 mm/min to achieve a preferable microstructure. On the basis of the start block, many newly formed grains appeared due to the chilling effect of the chilling copper plate. With the increase of location height, these grains continuously coarsened and competed, and the grain density gradually decreased. Only a few grains entered into the spiral selector, and only one grain with the orientation close to [001] preferential orientation could get through it to form the SX structure of the plate casting. From the lower to the upper part of the SX plate casting, the primary dendritic arm spacing first decreased from 467.7 to 435.22 μm, and then increased to 565.81 μm; the secondary dendritic arm spacing increased by 11.4%, from 181.39 to 202.13 μm. The γ′ phases in the dendritic arms showed a cubical morphology, and some micropores appeared near the eutectic particles. The simulated grain structure evolutions conformed well with the experiments.

Keywords

Single-crystal Superalloy Numerical simulation Spiral selector Dendritic spacing 
This is a preview of subscription content, log in to check access.

Notes

Acknowledgements

This research was funded by the National Science and Technology Major Project (2017ZX04014001) and National Key R&D Program of China (2017YFB0701503).

References

  1. 1.
    J.H. Perepezko, The hotter the engine, the better. Science 326(5956), 1068–1069 (2009)CrossRefGoogle Scholar
  2. 2.
    R.C. Reed, The superalloys fundamentals and applications (Cambridge University Press, New York, 2006)CrossRefGoogle Scholar
  3. 3.
    M.M. Franke, R.M. Hilbinger, A. Lohmüller, R.F. Singer, The effect of liquid metal cooling on thermal gradients in directional solidification of superalloys: thermal analysis. J. Mater. Process. Technol. 213(12). 2081–2088 (2013)CrossRefGoogle Scholar
  4. 4.
    J.D. Miller, T.M. Pollock, Stability of dendrite growth during directional solidification in the presence of a non-axial thermal field. Acta Mater. 78, 23–36 (2014)CrossRefGoogle Scholar
  5. 5.
    J.D. Miller, L. Yuan, P.D. Lee, T.M. Pollock, Simulation of diffusion-limited lateral growth of dendrites during solidification via liquid metal cooling. Acta Mater. 69, 47–59 (2014)CrossRefGoogle Scholar
  6. 6.
    H. Zhang, Q. Xu, B. Liu, Numerical simulation and optimization of directional solidification process of single crystal superalloy casting. Materials 7(3), 1625–1639 (2014)CrossRefGoogle Scholar
  7. 7.
    D. Ma, P.R. Sahm, Primary spacing in directional solidification. Metall. Mater. Trans. 29A, 1113–1119 (1998)CrossRefGoogle Scholar
  8. 8.
    F. Wang, D.X. Ma, J. Zhang, S. Bogner, A. Bührig-Polaczek, A high thermal gradient directional solidification method for growing superalloy single crystals. J. Mater. Process. Technol. 214(12), 3112–3121 (2014)CrossRefGoogle Scholar
  9. 9.
    F. Wang, D. Ma, J. Zhang, S. Bogner, A. Bührig-Polaczek, Solidification behavior of a Ni-based single crystal CMSX-4 superalloy solidified by downward directional solidification process. Mater. Charact. 101, 20–25 (2015)CrossRefGoogle Scholar
  10. 10.
    F. Wang, D. Ma, J. Zhang, L. Liu, J. Hong, S. Bogner, A. Bührig-Polaczek, Effect of solidification parameters on the microstructures of superalloy CMSX-6 formed during the downward directional solidification process. J. Cryst. Growth 389, 47–54 (2014)CrossRefGoogle Scholar
  11. 11.
    F. Wang, D. Ma, J. Zhang, A. Bührig-Polaczek, Investigation of segregation and density profiles in the mushy zone of CMSX-4 superalloys solidified during downward and upward directional solidification processes. J. Alloy. Compd. 620, 24–30 (2015)CrossRefGoogle Scholar
  12. 12.
    F. Wang, D. Ma, J. Zhang, L. Liu, S. Bogner, A. Bührig-Polaczek, Effect of local cooling rates on the microstructures of single crystal CMSX-6 superalloy: a comparative assessment of the bridgman and the downward directional solidification processes. J. Alloy. Compd. 616, 102–109 (2014)CrossRefGoogle Scholar
  13. 13.
    X. Yang, D. Ness, P.D. Lee, N. D’Souza, Simulation of stray grain formation during single crystal seed melt-back and initial withdrawal in the Ni-base superalloy CMSX-4. Mater. Sci. Eng. A413–414, 571–577 (2005)CrossRefGoogle Scholar
  14. 14.
    D. Szeliga, K. Kubiak, J. Sieniawski, Control of liquidus isotherm shape during solidification of Ni-based superalloy of single crystal platforms. J. Mater. Process. Technol. 234, 18–26 (2016)CrossRefGoogle Scholar
  15. 15.
    X.B. Meng, J.G. Li, Z.Q. Chen, Y.H. Wang, S.Z. Zhu, X.F. Bai, F. Wang, J. Zhang, T. Jin, X.F. Sun, Z.Q. Hu, Effect of platform dimension on the dendrite growth and stray grain formation in a Ni-base single-crystal superalloy. Metall. Mater. Trans. 44A, 1955–1965 (2012)Google Scholar
  16. 16.
    X.B. Meng, J. Li, S. Zhu, H. Du, Z. Yuan, J. Wang, T. Jin, X. Sun, Z. Hu, Method of stray grain inhibition in the platforms with different dimensions during directional solidification of a Ni-base superalloy. Metall. Mater. Trans. 45A, 1230–1237 (2013)Google Scholar
  17. 17.
    R. Wang, X. Yan, Z. Li, Q. Xu, B. Liu, Effect of construction manner of mould cluster on stray grain formation in dummy blade of DD6 superalloy. High Temp. Mater. Processes 36(4), 399–409 (2017)CrossRefGoogle Scholar
  18. 18.
    J. Hong, D. Ma, J. Wang, F. Wang, A. Dong, B. Sun, A. Bührig-Polaczek, Geometrical effect of freckle formation on directionally solidified superalloy CM247 LC components. J. Alloys Compd. 648, 1076–1082 (2015)CrossRefGoogle Scholar
  19. 19.
    D. Ma, A.B. Polaczed, The influence of surface roughness on freckle formation in directionally solidified superalloy samples. Metall. Mater. Trans. 43B, 671–677 (2012)CrossRefGoogle Scholar
  20. 20.
    D. Ma, Q. Wu, B.P. Andreas, Some new observations on freckle formation in directionally solidified superalloy components. Metall. Mater. Trans. 43B, 344–357 (2012)CrossRefGoogle Scholar
  21. 21.
    J.W. Aveson, P.A. Tennant, B.J. Foss, B.A. Shollock, H.J. Stone, N. D′ Souza, On the origin of sliver defects in single crystal investment castings. Acta Mater. 61(14), 5162–5171 (2013)CrossRefGoogle Scholar
  22. 22.
    L. Cao, L. Yao, Y. Zhou, T. Jin, X. Sun, Formation of the surface eutectic of a Ni-based single crystal superalloy. J. Mater. Sci. Technol. 33(4), 347–351 (2017)CrossRefGoogle Scholar
  23. 23.
    H.N. Mathur, C. Panwisawas, C.N. Jones, R.C. Reed, C.M.F. Rae, Nucleation of recrystallisation in castings of single crystal Ni-based superalloys. Acta Mater. 129, 112–123 (2017)CrossRefGoogle Scholar
  24. 24.
    C. Panwisawas, H. Mathur, J. Gebelin, D. Putman, C.M.F. Rae, R.C. Reed, Prediction of recrystallization in investment cast single-crystal superalloys. Acta Mater. 61(1), 51–66 (2013)CrossRefGoogle Scholar
  25. 25.
    L.H. Rettberg, T.M. Pollock, Localized recrystallization during creep in nickel-based superalloys GTD444 and René N5. Acta Mater. 73, 287–297 (2014)CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  1. 1.Key Laboratory for Advanced Materials Processing Technology (MOE), School of Materials Science and EngineeringTsinghua UniversityBeijingChina

Personalised recommendations

Cite paper

Buy options