Simulation of Low Frequency Electromagnetic DC Casting

Abstract:

A comprehensive multiphysics model has been developed to describe the effect of the low frequency electromagnetic field (LFEM) [1, on solidification in the hot-top Direct-Chill (DC) casting [ of round aluminium alloy billets. The volume averaged equations and the rigid solid phase assumption are assumed for fluid flow and heat transfer [. The electromagnetic induction equation for the field imposed by the coil is solved using the diffuse approximate method (DAM), structured in axial symmetry with Gaussian weight function, 6 polynomial basis and 9 nodded domains. The heat, mass, and momentum transfer equations are solved in primitive variables by meshless [ method using 5 nodded domains of influence and 5 scaled multiquadrics radial basis functions, using collocation. Explicit time stepping is used. Pressure-velocity coupling is performed by the fractional step method. The effects of intensity and frequency of the LFEM [ on the velocity and temperature fields is investigated. A comparison of the calculated results with different LFEM field process variables with that of the conventional hot-top DC casting process indicates that the velocity patterns, the temperature profiles, and the shape of the sump could be modified remarkably.

• Periodical: Materials Science Forum (Volumes 790-791)
• Pages: 390-395
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.790-791.390
• Online since: May 2014
• Authors: Nejc Kosnik, Robert Vertnik, Božidar Šarler
• Keywords: Aluminium Alloy, Direct-Chill Casting, Hot Top, Low Frequency Electromagnetic Casting, Meshless Method

References

[1] P.A. Davidson, An Introduction to Magnetohydrodynamics, Cambridge University Press, Cambridge, (2001).

[2] J. Dong, J.Z. Cui, Effect of low-frequency electromagnetic casting on the castability, microstructure, and tensile properties of direct-chill cast Al-Zn-Mg-Cu alloy, Metallurgical and Materials Transactions 35A (2004) 2487–2495.

DOI: 10.1007/s11661-006-0228-2

[3] H. Zhang, H. Nagaumi, Y. Zuo, J. Cui, Coupled modelling of electromagnetic field, fluid flow, heat transfer and solidification during low frequency electromagnetic casting of 7XXX aluminum alloys. Part 1: Development of a mathematical model and comparison with experimental results, Materials Science and Engineering A 448 (2007).

DOI: 10.1016/j.msea.2006.10.062

[4] H. Zhang, H. Nagaumi, J. Cui, Coupled modelling of electromagnetic field, fluid flow, heat transfer and solidification during low frequency electromagnetic casting of 7XXX aluminum alloys. Part II: The effects of electromagnetic parameters on casting processes, Materials Science and Engineering A 448 (2007).

DOI: 10.1016/j.msea.2006.10.063

[5] Y. Zuo, H. Nagaumi, J. Cui, Study on the sump and temperature field during low frequency electromagnetic casting a superhigh strength Al–Zn–Mg–Cu alloy, Journal of Materials Processing Technology 197 (2008) 109–115.

DOI: 10.1016/j.jmatprotec.2007.06.020

[6] D.G. Eskin, Physical Metallurgy of Direct Chill Casting of Aluminium Alloys, CRC Press/Taylor & Francis, Boca Raton (2008).

[7] M. Založnik, X. Shin, B. Šarler, Verification of a numerical model of macrosegregation in direct chill casting. International Journal of Numerical Methods for Heat & Fluid Flow 18 (2008) 308-324.

DOI: 10.1108/09615530810853600

[8] G.R. Liu, G.T. Liu, An Introduction to Meshfree Methods and Their Programming, Springer, Berlin, (2005).

[9] R. Vertnik, M. Založnik, B. Šarler, Solution of transient direct-chill aluminium billet casting problem with simultaneous material and interphase moving boundaries by a meshless method, Engineering Analysis with Boundary Elements 30 (2006).

DOI: 10.1016/j.enganabound.2006.05.004

[10] O. Schenk, K. Gärtner, Solving unsymmetric sparse systems of linear equations with PARDISO. Journal of Future Generation Computer Systems 20 (2004) 475–487.

DOI: 10.1016/j.future.2003.07.011

[11] O. Schenk, K. Gärtner, On fast factorization pivoting methods for symmetric indefinite systems. Elec. Trans. Numer. Anal. 23 (2006) 158–179.