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Convective effect on the solidification of hypermonotectic alloys

Published online by Cambridge University Press:  25 March 2011

Haili Li  and
Jiuzhou Zhao
Haili Li
Affiliation:
Shenyang Ligong University, Shenyang 110159, China
Jiuzhou Zhao*
Affiliation:
Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
*
a)Address all correspondence to this author. e-mail: jzzhao@imr.ac.cn
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Abstract

A model is developed to analyze the microstructure evolution in a continuously solidified hypermonotectic alloy. The model takes into account the common actions of the nucleation and diffusional growth/shrinkage of the minority phase droplets, the spatial phase segregation, and the convections of the melt. The microstructure formation in a continuously solidified hypermonotectic alloy is calculated. The numerical results demonstrate that the convections have great effect on the microstructure formation. The convective flow against the solidification direction causes an increase in the nucleation rate while the convective flow along the solidification direction causes a decrease in the nucleation rate of the minority phase droplets. The convections lead to a more nonuniform distribution of the minority phase droplets in the melt. It causes an increase in the size of the largest minority phase droplets and is against the obtaining of the hypermonotectic alloys with a well-dispersed microstructure.

Keywords

SimulationPhase TransformationRapid Solidification
Type
Articles
Information
Journal of Materials Research , Volume 26 , Issue 6 , 28 March 2011 , pp. 832 - 836
Copyright
Copyright © Materials Research Society 2011

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References

REFERENCES

1.Zhao, J.Z., Li, H.L., and Zhao, L.: Effect of convections and motions of minority phase droplets on solidification of monotectic alloys. Acta Metall. Sinica 45, 1335 (2009).Google Scholar
2.Zhao, J.Z. and Ratke, L.: A model describing the microstructure evolution during a cooling of immiscible alloys in the miscibility gap. Scr. Mater. 50, 543 (2004).CrossRefGoogle Scholar
3.Carlberg, T. and Fredriksson, H.: The influence of microgravity on the solidification of Zn–Bi immiscible alloy. Metall. Trans. A 11, 1165 (1980).CrossRefGoogle Scholar
4.Ozawa, S. and Motegi, T.: Solidification of hyper-monotectic Al–Pb alloy under microgravity using a 1000-in. drop shaft. Mater. Lett. 58, 2548 (2004).CrossRefGoogle Scholar
5.Davis, R.H. and Hassen, M.A.: Spreading of the interface at the top of a slightly polydisperse sedimenting susoension. J. Fluid Mech. 196, 107 (1988).CrossRefGoogle Scholar
6.Li, L.H. and Zhao, J.Z.: Microstructure formation in a directionally solidified immiscible alloy. Metall. Mater. Trans. A 39, 3308 (2008).CrossRefGoogle Scholar
7.Zhao, J.Z.: Formation of the minor phase shell on the surface of hypermonotectic alloy powders. Scr. Mater. 54, 247 (2006).CrossRefGoogle Scholar
8.Guo, J.J., Liu, Y., Jia, J., Su, Y.Q., and Ding, H.S.: Coarsening process of minority phase droplets during rapidly cooling an immiscible alloy through the miscibility gap. Acta Metall. Sinica 37, 363 (2001).Google Scholar
9.Cao, C.D. and Wei, B.B.: Microstructure evolution of Cu–Pb monotectic alloys processed in drop tube. J. Mater. Sci. Technol. 18, 73 (2002).Google Scholar
10.Wu, M.H., Ludwig, A., and Ratke, L.: Modeling of Marangoni-induced droplets motion and melt convection during solidification of hypermonotectic alloys. Metall. Mater. Trans. A 34, 3009 (2003).CrossRefGoogle Scholar
11.Li, H.L., Zhao, J.Z., and Zhang, Q.X.: Microstructure formation in a directionally solidified immiscible alloy metall. Mater. Trans. A 39, 3308 (2008).CrossRefGoogle Scholar
12.Ratke, L. and Thieringer, W.K.: The influence of particle motion on Ostwald ripening in liquids. Acta Metall. 33, 1973 (1985).CrossRefGoogle Scholar
13.Rogers, J.R. and Davis, R.H.: Modeling of collision and coalescence of droplets during microgravity processing of Zn–Bi immiscible alloy. Metall. Trans. A 21, 59 (1990).CrossRefGoogle Scholar
14.Christian, J.: The Theory of Phase Transformations in Metals and Alloys, 2nd ed. (Pergamon Press, Oxford, UK, 1975), p. 1-I.Google Scholar
15.Zhao, J.Z., Ratke, L., and Feuerbacher, B.: Microstructure evolution of immiscible alloys during cooling through the miscibility gap. Model. Simul. Mater. Sci. Eng. 6, 123 (1998).CrossRefGoogle Scholar
16.Thompson, C.V. and Spaepen, F.: Homogeneous crystal nucleation in binary metallic melts. Acta Metall. 31, 2021 (1983).CrossRefGoogle Scholar
17.Beer, S.Z.: Liquid Metals, (Marcel Dekker Inc., New York, 1972), p. 415.Google Scholar