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Grain refinement effect of pulsed magnetic field on solidified microstructure of superalloy IN718

Published online by Cambridge University Press:  31 January 2011

Yuansheng Yang*
Affiliation:
Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
*
a) Address all correspondence to this author. e-mail: ysyang@imr.ac.cn
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Abstract

The refinement mechanism of pulsed magnetic field (PMF) was discussed by experimental investigation, and the effects of exciting frequency, exciting voltage, and delay time of PMF on grains refinement of superalloy were studied. The experimental results show that, as exciting frequency or exciting voltage is increased, the grains are refined. However, the grains become coarse when frequency increases further. As delay time of PMF increases, the grain size increases. The refinement effect of PMF is attributed to the detachment of heterogeneous nuclei on the mold wall and subsequently separation of nuclei in the melt. The Joule heat can prolong the continuous nucleation process. However, the refinement effect will be impaired if the Joule heat is strong enough to remelt the detached nuclei.

Type
Articles
Copyright
Copyright © Materials Research Society 2009

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References

1.Woulds, M. and Benson, H.: Development of a conventional fine grain casting process, in Proceedings of the Superalloy 1984, edited by Gell, M. (TMS-AIME, New York, 1984), p. 3.Google Scholar
2.Mondolfo, L.F.: Grain refinement in the casting of non-ferrous alloys, in Grain Refinement in Casting and Welds, edited by Addaeshian, G.J. (TMS-AIME, Warrendale, PA, 1983), p. 3.Google Scholar
3.Bouse, G.K. and Behrendt, M.R.: Mechanical properties of microcast-X alloy 718 fine grain investment castings, in Superalloy 718—Metallurgy and Applications, edited by Loria, E. (TMS, Warrendale, PA, 1989), p. 319.Google Scholar
4.Vives, C.: Electromagnetic refining of aluminum alloys by the CREM process: Part I. Working principle and metallurgical results. Metall. Trans. B 20, 623 (1989).CrossRefGoogle Scholar
5.Radjai, A. and Miwa, K.: 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).CrossRefGoogle Scholar
6.Takagi, T., Iwai, K., and Asai, S.: Solidified structure of Al alloys by a local imposition of an electromagnetic oscillating force. ISIJ Int. 43, 842 (2003).CrossRefGoogle Scholar
7.Mizutani, Y., Tamura, T. and Miwa, K.: Microstructural refinement process of pure magnesium by electromagnetic vibrations. Mater. Sci. Eng., A 413414, 205 (2005).Google Scholar
8.Guo, S.J., Le, Q.C., Zhao, Z.H., Wang, Z.J., and Cui, J.Z.: Microstructural refinement of DC cast AZ80 Mg billets by low frequency electromagnetic vibration. Mater. Sci. Eng., A 404, 323 (2005).CrossRefGoogle Scholar
9.Li, M.J., Tamura, T., and Miwa, K.: Controlling microstructures of AZ31 magnesium alloys by an electromagnetic vibration technique during solidification: From experimental observation to theoretical understanding. Acta Mater. 55, 4635 (2007).CrossRefGoogle Scholar
10.Zi, B.T., Ba, Q.X., and Cui, J.Z.: Study on axial changes of as-cast structures of Al-alloy sample treated by the novel SPMF technique. Scr. Mater. 43, 377 (2000).Google Scholar
11.Zi, B.T., Ba, Q.X., Cui, J.Z., Bai, Y.G., and Yan, X.J.: Effect of strong pulsed electromagnetic field on metal's solidified structure. Acta Phys. Sin. 49, 1010 (2000).Google Scholar
12.Gao, Y.L., Li, Q.S., Gong, Y.Y., and Zhai, Q.J.: Comparative study on structural transformation of low-melting pure Al and highmelting stainless steel under external pulsed magnetic field. Mater. Lett. 61, 4011 (2007).CrossRefGoogle Scholar
13.Li, Q.S., Song, C.J., Li, H.B., and Zhai, Q.J.: Effect of pulsed magnetic field on microstructure of 1Cr18Ni9Ti austenitic stainless steel. Mater. Sci. Eng., A 466, 101 (2007).CrossRefGoogle Scholar
14.Zhou, Q., Yang, Y.S., and Ma, J.C.: Effect of pulsed magnetic field on solidified structure of AZ91D magnesium alloy. Foundry 56, 148 (2007).Google Scholar
15.Wang, B., Yang, Y.S., Zhou, J.X., and Tong, W.H.: Microstructure refinement of AZ91D alloy solidified with pulsed magnetic field. Trans. Nonferrous Met. Soc. China 18, 536 (2008).CrossRefGoogle Scholar
16.Ohno, A.: Solidification—the Separation Theory and Its Practical Applications (Springer-Verlag Press, Berlin, 1987).Google Scholar
17.Ohno, A., Motegi, T., and Soda, H.: Origin of the equiaxed crystals in castings. Trans ISIJ. 11, 18 (1971).CrossRefGoogle Scholar
18.Ma, X.P., Yang, Y.S., and Wang, B.: Effect of pulsed magnetic field on superalloy melt. Int. J. Heat Mass Transfer (in press), DOI: 10.1016/j.ijheatmasstransfer.2009.06.042.CrossRefGoogle Scholar
19.Ma, X.P., Li, Y.J., and Yang, Y.S.: Grain refinement effect of pulsed magnetic field on as-cast superalloy K417. J. Mater. Res. 24, 2670 (2009).CrossRefGoogle Scholar