Abstract
The grain refinement effect of a pulsed magnetic field on superalloy K417 was studied. The experimental results show that fine equiaxed grains are acquired with proper thermal control under the pulsed magnetic field. The refinement effect of the pulsed magnetic field is affected by the melt cooling rate and the melt superheating. The refinement effect of the pulsed magnetic field is attributed to the dissociation of nuclei from the mold wall by melt vibration and the subsequent dispersion of nuclei by melt convection. The Joule heat and the melt convection caused by the pulsed magnetic field may defer the formation of solidified shell, which prolongs the continuous refinement process. The decrease of melt cooling rate reduces the number of nuclei produced on the mold wall but prolongs the duration for the nuclei to depart from the mold wall and disperse in the melt, which enhances the refinement effect of the pulsed magnetic field. The increase of melt superheating lessens the survival probability of the nuclei in the melt, which weakens the refinement effect of the pulsed magnetic field.
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References
M. Woulds and H. Benson: Development of a conventional fine grain casting process, in Proceedings of the Superalloy 1984, edited by M. Gellm (Met. Soc. TMS-AIME, New York, 1984), p. 3.
E. Chang, B. Tseng, J.C. Chou, and V. Yin: Processing structure and mechanical property of investment cast IN713LC superalloy. AFS Trans. 96, 47 (1988).
L.F. Mondolfo: Grain refinement in the casting of non-ferrous alloys, in Grain Refinement in Casting and Welds, edited by G.J. Addaeshian (TMS-AIME, Warrendale, PA, 1983), p. 3.
B.A. Ewing and K.A. Green: Polycrystalline grain controlled castings for rotating compressor and turbine components, in Superalloys 1984, edited by M. Gell (TMS-AIME, Warrendale, PA, 1984), p. 33.
G.K. Bouse and M.R. Behrendt: Mechanical properties of microcast-X alloy 718 fine grain investment castings, in Superalloy 718–Metallurgy and Applications, edited by E. Loria (Met. Soc., Warrendale, PA, 1989), p. 319.
C. Vives: Effects of electromagnetic vibrations on the microstructure of continuously cast aluminum alloys. Mater. Sci. Eng. A. 173, l69 (1993).
A. Radjai and K. Miwa: Effects of the intensity and frequency of electromanetic vibrations on the microstructural refinement of hypereutectic Al-Si alloys. Metall. Mater. Trans A. 31, 755 (2000).
Y. Mizutani, T. Tamura, and K. Miwa: Microstructural refinement process of pure magnesium by electromagnetic vibrations. Mater. Sci. Eng. A. 413–414, 205 (2005).
B.T. Zi, Q.X. Ba, J.Z. Cui, Y.G. Bai, and X.J. Yan: Effect of strong pulsed electromagnetic field on metal’s solidified structure. Acta Phys. Sin. 49, 1010 (2000).
Y.L. Gao, Q.S. Li, Y.Y. Gong, and Q.J. Zhai: Comparative study on structural transformation of low-melting pure Al and highmelting stainless steel under external pulsed magnetic field. Mater. Lett. 61, 4011 (2007).
Q.S. Li, C.J. Song, H.B. Li, and Q.J. Zhai: Effect of pulsed magnetic field on microstructure of 1Cr18Ni9Ti austenitic stainless steel. Mater. Sci. Eng. A. 466, 101 (2007).
Q. Zhou, Y.S. Yang, and J.C. Ma: Effect of pulsed magnetic field on solidified structure of AZ91D magnesium alloy. Foundry 56, 148 (2007).
B. Wang, Y.S. Yang, J.X. Zhou, and W.H. Tong: Microstructure refinement of AZ91D alloy solidified with pulsed magnetic field. Trans. Nonferrous Met. Soc. China 18, 536 (2008).
R.T. Southin: Nucleation of the equiaxed zone in cast metals. Trans. TMS. 239, 220 (1976).
B. Chalmers: Principle of Solidification (John Wiley, New York, 1964), p. 259.
T.A. El-Bassyouni, A.A. Badr, A.N. Abdelm-Azim, J. Lakner, and Z. Olah: Effect of electromagnetic forces on aluminum cast structure. Light Metals 33, 733 (1983).
B.T. Zi, K.F. Yao, G.M. Xu, and J.Z. Cui: Numerical simulation of liquid alloy flow field during solidification under applied pulsed magnetic fields. Acta Phys. Sin. 52, 115 (2003).
A. Ohno: Solidification—The Separation Theory and Its Practical Applications (Springer-Verlag, Berlin, 1987), p. 15.
A. Ohno, T. Motegi, and H. Soda: Origin of the equiaxed crystals in castings. Trans. ISIJ 11, 18 (1971).
D.M. Herlach, K. Eckler, A. Karma, and M. Schwarz: Grain refinement through fragmentation of dendrites in undercooled melts. Mater. Sci. Eng. A. 304–306, 20 (2001).
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Ma, X., Li, Y. & Yang, Y. Grain refinement effect of a pulsed magnetic field on as-cast superalloy K417. Journal of Materials Research 24, 2670–2676 (2009). https://doi.org/10.1557/jmr.2009.0326
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DOI: https://doi.org/10.1557/jmr.2009.0326