Modeling the fluid dynamics and dendritic solidification in EM-levitated alloy melts

Bojarevics, Valdis, Kao, Andrew and Pericleous, Koulis (2012) Modeling the fluid dynamics and dendritic solidification in EM-levitated alloy melts. In: Solidification of Containerless Undercooled Melts. Wiley-VCH Verlag & Co., Weinheim, Germany, pp. 321-348. ISBN 9783527331222

Abstract

Containerless melting and solidification requires a sample that is in some way suspended, or levitated against gravity, away from contact with any containing walls. There are several ways of achieving this goal, as given in earlier chapters. In the case of electromagnetic levitation, the lifting/confining force is commonly provided using a medium/high-frequency AC current positioning coil. An opposing eddy current develops within the sample, which in this case needs to be electrically conducting; the interaction of the coil and induced currents leads to the repelling Lorentz force. Other interactions follow as a consequence: assuming that the sample is an alloy melt, the Lorentz force also drives convection within it and the induced current generates resistive heat in a sample of finite conductivity. These two effects have a bearing on how solidification proceeds and therefore it is important that they are accurately represented in any mathematical model of the process.

Actions (login required)