Eur. Phys. J. Special Topics 220, 123-137 (2013)
https://doi.org/10.1140/epjst/e2013-01802-7

Review

Electromagnetic melt flow control during solidification of metallic alloys

¹ Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Fluid Dynamics, 01314 Dresden, Germany
² Technische Universität Dresden (TUD), Institute of Fluid Mechanics, 01062 Dresden, Germany
³ TUD, Institute for Scientific Computing, 01062 Dresden, Germany
⁴ TU Bergakademie Freiberg, CIC Virtuhcon Department of Energy, Process- and Chemical Engineering, Fuchsmühlenweg 9, 09596 Freiberg, Germany

Received: 16 January 2013
Revised: 5 February 2013
Published online: 26 March 2013

Abstract

In this minireview, we summarize experimental and numerical studies particularly concerned with applications of rotating magnetic fields (RMF) or travelling magnetic fields (TMF) to directional solidification of metal alloys. After introducing some fundamentals of electromagnetic stirring, we review the insights gained into flow-induced modifications of microstructure and the formation of freckles and macrosegregations. We further discuss recent strategies, using time-modulated RMF and TMF, which aim to overcome the deficiencies of conventional stirring, in particular flow-induced macrosegregation, by effectively controlling the flow field. On the microscale, we show that time-varying flows are able to alter the sidebranch characteristics vital to the potential of fragmentation.