Electromagnetic Braking of Natural Convection during Ohno Continuous Casting of an Industrial Aluminum Alloy
Author(s)
Simbarashe Fashu
Affiliation(s)
Department of Materials Science and Engineering, Harare Institute of Technology, Harare, Zimbabwe.
Department of Materials Science and Engineering, Harare Institute of Technology, Harare, Zimbabwe.
ABSTRACT
With the purpose of obtaining compositionally uniform ingots during Ohno continuous casting of a dilute industrial aluminum alloy through eliminating segregation due to convection, a magnetic field strength required to damp natural convection and suppress macrosegregation was numerically determined. This was achieved by solving conservation equations of continuity, momentum, energy and Maxwell’s equations in order to predict the magnetic field effects on flow field (determining macrosegregation). The electromagnetic field was applied orthogonally to the natural convection flow. Through this approach, the optimum magnetic field strength required to damp natural convection and establish diffusion controlled solute transport of the alloy during solidification was established.
With the purpose of obtaining compositionally uniform ingots during Ohno continuous casting of a dilute industrial aluminum alloy through eliminating segregation due to convection, a magnetic field strength required to damp natural convection and suppress macrosegregation was numerically determined. This was achieved by solving conservation equations of continuity, momentum, energy and Maxwell’s equations in order to predict the magnetic field effects on flow field (determining macrosegregation). The electromagnetic field was applied orthogonally to the natural convection flow. Through this approach, the optimum magnetic field strength required to damp natural convection and establish diffusion controlled solute transport of the alloy during solidification was established.
Cite this paper
Fashu, S. (2015) Electromagnetic Braking of Natural Convection during Ohno Continuous Casting of an Industrial Aluminum Alloy. International Journal of Nonferrous Metallurgy, 4, 37-45. doi: 10.4236/ijnm.2015.44005.
Fashu, S. (2015) Electromagnetic Braking of Natural Convection during Ohno Continuous Casting of an Industrial Aluminum Alloy. International Journal of Nonferrous Metallurgy, 4, 37-45. doi: 10.4236/ijnm.2015.44005.
References
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http://dx.doi.org/10.1016/j.jcrysgro.2004.06.020 [5] Watring, D.A. and Lehoczky, S.L. (1996) Magne-to-Hydrodynamic Damping of Convection during Vertical Bridgman- Stockbarger Growth of HgCdTe. Journal of Crystal Growth, 167, 478-487.
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http://dx.doi.org/10.1007/s00348-005-0065-x [7] Lei, H., Zhang, H. and He, J. (2009) Flow, Solidification, and Solute Transport in a Continuous Casting Mold with Electromagnetic Brake. Chemical Engineering & Technology, 32, 991-1002.
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http://dx.doi.org/10.1007/s11663-007-9109-3 [10] Mechighel, H. and Kadja, M. (2007) External Horizontally Uniform Magnetic Field Applied to Steel Solidification. Journal of Applied Sciences, 7, 903-912.
http://dx.doi.org/10.3923/jas.2007.903.912 [11] Wei, J.A., Zheng, L. and Zhang, H. (2009) Suppression of Melt Convection in a Proposed Bridgman Crystal Growth System. International Journal of Heat and Mass Transfer, 52, 3747-3756.
http://dx.doi.org/10.1016/j.ijheatmasstransfer.2009.02.029 [12] Battira, M. and Bessaih, R. (2008) Three-Dimensional Natural Convection in the Horizontal Bridgman Configuration under Various Wall Electrical Conductivity and Magnetic Field. Numerical Heat Transfer, Part A: Applications, 55, 58-76.
http://dx.doi.org/10.1080/10407780802603113 [13] Gelfgat, A. and Yoseph, P. (2001) The Effect of an External Magnetic Field on Oscillatory Instability of Convective Flows in a Rectangular Cavity. Physics of Fluids, 13, 2269-2278.
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[1] Ohno, A. (1986) Continuous Casting of Single Crystal Ingot by the OCC Process. Journal of Metals, 38, 14-16. [2] Ganapathysubramanian, B. and Zabaras, N. (2005) On the Control of Solidification Using Magnetic Fields and Magnetic Field Gradients. International Journal of Heat and Mass Transfer, 48, 4174-4189.
http://dx.doi.org/10.1016/j.ijheatmasstransfer.2005.04.027 [3] Hof, B., Juel, A. and Mullin, T. (2003) Magneto-hydrodynamic Damping of Convective Flows in Molten Gallium. Journal of Fluid Mechanics, 482, 63-179. [4] Ganapathysubramanian, B. and Zabaras, N. (2004) Using Magnetic Field Gradients to Control the Directional Solidification of Alloys and the Growth of Single Crystals. Journal of Crystal Growth, 270, 255-272.
http://dx.doi.org/10.1016/j.jcrysgro.2004.06.020 [5] Watring, D.A. and Lehoczky, S.L. (1996) Magne-to-Hydrodynamic Damping of Convection during Vertical Bridgman- Stockbarger Growth of HgCdTe. Journal of Crystal Growth, 167, 478-487.
http://dx.doi.org/10.1016/0022-0248(96)00279-5 [6] Bojarevics, A., Cramer, A., Gelfgatand, Y.U. and Gerbeth, G. (2006) Experiments on the Magnetic Damping of an Inductively Stirred Liquid Metal Flow. Experiments in Fluids, 40, 257-266.
http://dx.doi.org/10.1007/s00348-005-0065-x [7] Lei, H., Zhang, H. and He, J. (2009) Flow, Solidification, and Solute Transport in a Continuous Casting Mold with Electromagnetic Brake. Chemical Engineering & Technology, 32, 991-1002.
http://dx.doi.org/10.1002/ceat.200800346 [8] Tian, X., Zou, F., Li, B. and He, J. (2010) Numerical Analysis of Coupled Fluid Flow, Heat Transfer and Macroscopic Solidification in the Thin Slab Funnel Shape Mold with a New Type EMBr. Metallurgical and Materials Transactions B, 40, 112-120.
http://dx.doi.org/10.1007/s11663-009-9314-3 [9] Cukierski, K. and Thomas, B. (2008) Flow Control with Local Electromagnetic Braking in Continuous Casting of Steel Slabs. Metallurgical and Materials Transactions B, 39, 94-107.
http://dx.doi.org/10.1007/s11663-007-9109-3 [10] Mechighel, H. and Kadja, M. (2007) External Horizontally Uniform Magnetic Field Applied to Steel Solidification. Journal of Applied Sciences, 7, 903-912.
http://dx.doi.org/10.3923/jas.2007.903.912 [11] Wei, J.A., Zheng, L. and Zhang, H. (2009) Suppression of Melt Convection in a Proposed Bridgman Crystal Growth System. International Journal of Heat and Mass Transfer, 52, 3747-3756.
http://dx.doi.org/10.1016/j.ijheatmasstransfer.2009.02.029 [12] Battira, M. and Bessaih, R. (2008) Three-Dimensional Natural Convection in the Horizontal Bridgman Configuration under Various Wall Electrical Conductivity and Magnetic Field. Numerical Heat Transfer, Part A: Applications, 55, 58-76.
http://dx.doi.org/10.1080/10407780802603113 [13] Gelfgat, A. and Yoseph, P. (2001) The Effect of an External Magnetic Field on Oscillatory Instability of Convective Flows in a Rectangular Cavity. Physics of Fluids, 13, 2269-2278.
http://dx.doi.org/10.1063/1.1383789 [14] Hurle, D. (1966) Temperature Oscillations in Molten Metals and Their Relationship to Growth Striae in Melt-Grown Crystals. Philosophical Magazine, 13, 305-310.
http://dx.doi.org/10.1080/14786436608212608 [15] Utech, H.P. and Flemings, M.C. (1966) Elimination of Solute Banding in Indium Antimonide Crystals by Growth in a Magnetic Field. Journal of Applied Physics, 37, 2021-2024.
http://dx.doi.org/10.1063/1.1708664 [16] Utech, H.P. and Flemings, M.C. (1967) Thermal Convection in Metal-Crystal Growth—Effect of a Magnetic Field. Journal of Physics and Chemistry of Solids, 28, 651. [17] Oreper, H.P. and Szekely, J. (1984) The Effect of a Magnetic Field on Transport Phenomena in a Bridgman-Stock-barger Crystal Growth. Journal of Crystal Growth, 67, 405-419.
http://dx.doi.org/10.1016/0022-0248(84)90033-2 [18] Rudraiah, N., Barron, R.M., Venkatachalappa, M. and Subbaraya, C. (1995) Effect of a Magnetic Field on Free Convection in a Rectangular Enclosure. International Journal of Engineering Science, 33, 1075-1084.
http://dx.doi.org/10.1016/0020-7225(94)00120-9 [19] Motakef, S. (1990) Magnetic Field Elimination of Convective Interference with Segregation during Vertical-Bridgman Growth of Doped Semiconductors. Journal of Crystal Growth, 104, 833-850.
http://dx.doi.org/10.1016/0022-0248(90)90109-X [20] Kim, D.H., Adornato, P.M. and Brown, R.A. (1988) Effect of Vertical Magnetic Field on Convection and Segregation in Vertical Bridgman Crystal Growth. Journal of Crystal Growth, 89, 339-356.
http://dx.doi.org/10.1016/0022-0248(88)90419-8 [21] Ben Hadid, H., Henry, D. and Kaddeche, S. (1997) Numerical Study of Convection in the Horizontal Bridgman Configuration under the Action of a Constant Magnetic Field. Part 1. Two-Dimensional Flow. Journal of Fluid Mechanics, 333, 23-56.
http://dx.doi.org/10.1017/S0022112096004193 [22] Gunzberger, M., Ozugurlu, E., Turner, J. and Zhang, H. (2002) Controlling Transport Phenomena in the Czochralski Crystal Growth Process. Journal of Crystal Growth, 234, 47-62.
http://dx.doi.org/10.1016/S0022-0248(01)01635-9 [23] Bennon, D. and Incropera, F.P. (1987) A Continuum Model for Momentum, Heat and Species Transport in Binary Solid-Liquid Phase Change Systems—I. Model Formulation. International Journal of Heat and Mass Transfer, 30, 2161-2170.
http://dx.doi.org/10.1016/0017-9310(87)90094-9 [24] Fluent Inc. (2006) User’s Guide. 6.3.26 Version, Fluent Inc., New York.