Numerical and Experimental Evaluation of Stray Grains Formation During Single Crystal Growth

Document Type : Original Articles

Authors

• mohsen Ghanbari
• Saeed Shabestari
• Mohammad Reza Aboutalebi

Iran University of Science and Technology.

10.22067/ma.v28i2.35238

Abstract

Stray grain formation during single crystal growth with growth rates of 3, 5 and 7 mm/min has been assessed. The results revealed that increasing the growth rate resulted in the decrement of thermal gradient in the solidification front and caused stray grain formation in the solidification front of the columnar grain growth. Experimental and numerical results showed that a well-oriented single crystal structure is obtained at a growth rate of 3 mm/min in Ni-based superalloy. Stray grain formation occurred at growth rates greater than 3 mm/min, as a result of high growth rate and low thermal gradient.

Keywords

• Single Crystal Growth
• Stray Grains Formation
• Thermal Gradient
• Growth Rate
• Numerical simulation

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References

1. Reed R.C., "The Superalloys: Fundamentals and Applications", Cambridge University Press, Cambridge, (2006).

2. Ross E.W., Sims C.T., "Superalloy", John Wiley & Sons, New York, (1987).

3. Gell M., Duhl D.N., Giamei A.F., “Superalloys”, American Society for Metals, Metals Park, OH, (1980).

4. McLean M., "Directionally Solidified Materials for High Temperature Service", The Metals Society, (1983).

5. Versnyder F., Shank F.E., "The Development of Columnar Grain and Single Crystal High Temperature Materials through Directional Solidification", Materials Science and Engineering, Vol. 6, pp. 213-247, (1970).

6. Zhou Y.Z., Green N.R., "Mechanism of Competitive Grain Growth In Directional Solidification Of A Nickel-Base Superalloy", Acta Materialia, Vol. 56, pp. 2631–263, (2010).

7. Meng X.B., Lua Q., Zhang X.L., Li J.G., Chen Z.Q, Wang Y.H., Zhou Y.Z., Jin T., Sun X.F., Hu Z.Q., "Mechanism Of Competitive Growth During Directional Solidification Of A Nickel-Based Superalloy In A Three-Dimensional Reference Frame", Acta Materialia, Vol. 60, pp. 3965–3975, (2012).

8. Xinbao Zh., Lin L., Weiguo Zh., Min Q., Jun Zh., Hengzhi F., "Analysis of Competitive Growth Mechanism of Stray Grains of Single Crystal Superalloys during Directional Solidification Process", Rare Metal Materials and Engineering, Vol. 40, 9 -13, (2011).

9. Zhou Y.Z., Green N.R., "Mechanism of Competitive Grain Growth in Directional Solidification of A Nickel-Base Superalloy", Acta Materialia, Vol. 56, pp. 2631–2637, (2011).

10. Zhou Y., Volek A., "Effect Of Carbon Additions On Hot Tearing Of A Second Generation Nickel-Base Superalloy", Materials Science and Engineering A, Vol. 479, pp. 324-332, (2009).

11. Cutler E.R., Wasson A.J., Fuchs G.E., "Effect Of Minor Alloying Additions On The Solidification Of Single-Crystal Ni-Base Superalloys", Journal of Crystal Growth, Vol. 311, pp. 3753–3760., (2009).

12. Gunduz M., Adirli E.C., "Directional Solidification of Aluminium–Copper Alloys", Materials Science and Engineering A, Vol. A327, pp. V, (2002).

13. Ares A.E., Gueijman S.F., Schvezov C.E., "An Experimental Investigation of The Columnar-To-Equiaxed Grain Transition In Aluminium–Copper Hypoeutectic And Eutectic Alloys", Journal of Crystal Growth, Vol. 312, pp. 2154–2170, (2010).

14. Willers B., Eckert S., Michel B., Haase I., Zouhar G., "The Columnar-To-Equiaxed Transition In Pb–Sn Alloys Affected By Electromagnetically Driven Convection", Materials Science and Engineering A, Vol. 402, pp. 55-65, (2005).

15. Dong Q., Zhang J., Dong J., Xie H., Li Zh., Dai Y., Liu Y., Sun B., "In Situ Observation of Columnar-To-Equiaxed Transition In Directional Solidification Using Synchrotron X-Radiation Imaging Technique", Materials Science and Engineering A, Vol. 530, pp. 271-276, (2011).

16. Dantzig J.A., Rappaz M., "Solidification", EPFL Press, (2009).

17. Rappaz M., "Probabilistic Modeling of Microstructure Formation in Solidification Processes", Acta Metallurgica Materialia, Vol. 41, pp. 345-360, (1993).

18. Lin Zh., Cai-bei Zh., "Two-Dimensional Cellular Automaton Model for Simulation Structure Evolution of Binary Alloys during Solidification", Transactions of nonferrous metals society of China, Vol. 16, pp. 1410-1416, (2006).

19. Ying L., Qingyan L., Baicheng L., "A Modified Cellular Automaton Method for The Modelling Of Dendritic Morphology Of Binary Alloys", Tsinghua Science and Technology, Vol. 11, pp. 495-500, (2006).

20. Gandin Ch., Rappaz M., "a coupled finite element cellular automaton model for the prediction of the dendritic grain structure in solidification processes", Acta Metallurgica Materialia, Vol. 42, No. 7, pp. 2233-2246, (1994).

21. Gandin Ch., Desbioles J., Rappaz M., Thevez Ph., "A three-dimensional cellular automaton-finite element model for prediction of solidification grain structures", Metallurgical and Materials Transactions A, Vol. 30A, pp. 3153-3165, (1999).

22. Toloraiy, V.N., Orekhov N.G., Kablov E.N., "Advanced Method for Single Crystal Casting Of Turbine Blades For Gas Turbine Engines And Plants", Metal Science and Heat Treatment, Vol. 44, No. 7 – 8, pp.11-16 (2002).

23. Poirier D.R, "Transport phenomena in materials processing", ed. TMS. (1994).

24. Kurz W., Fischer D.J., "Fundamentals of Solidification", Trans Tech Publications, (1986).

25. Kurz W., Giovanola B., Trivedi R., "Theory of Microstructural Development during Rapid Solidification", Acta Metallurgica Materialia, Vol. 34, No. 5, pp. 823.-830, (1986).

26. Elliott, A.J., Tin S., King W.T., Huang S.C, Gigliotti M.F., Pollock T.M., "Directional Solidification of Large Superalloy Castings with Radiation and Liquid-Metal Cooling: A Comparative Assessment", Metallurgical and Materials Transactions A, Vol. 35A, pp. 3221-3231, (2004).

27. Li, X., Fautrelle Y., Ren Zh., Gagnoud A., Zhang Y., Esling C., "Morphological instability of interface, cell and dendrite during directional solidification under strong magnetic field", Journal of Crystal Growth, Vol. 318, pp. 23–27, (2011).

28. Zhou, Y., "Formation of stray grains during directional solidification of a nickel-based superalloy", Scripta Materialia, Vol. 65, pp. 281–284, (2011).