Premium
Free‐surface instabilities during electromagnetic shaping of liquid metals
Author(s) -
Karcher Ch.,
Kocourek V.
Publication year - 2007
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200700645
Subject(s) - liquid metal , lorentz force , levitation , magnetic levitation , drop (telecommunication) , free surface , electromagnetic field , mechanics , magnetic field , context (archaeology) , crucible (geodemography) , electromagnetic suspension , metal , materials science , chemistry , condensed matter physics , physics , composite material , metallurgy , magnet , mechanical engineering , engineering , paleontology , computational chemistry , quantum mechanics , biology
Electromagnetic shaping of free surfaces of liquid metals is a well‐known EPM technology used in a couple of metallurgic processes like cold crucible melting, semi‐levitation, and electromagnetic slit sealing, among others. However, the stability of such free surfaces is the most important problem and stability control is crucial for success. Within this context we investigate experimentally the stability behavior of liquid metal free surfaces submitted to a high‐frequency magnetic field. In this case, the induced Lorentz forces act as an electromagnetic pressure directly on the free surface of the liquid met al. We consider three experimental model configurations: (i) Sessile liquid metal drop (ii) liquid metal ring, and (iii) liquid metal disc. In each model experiment, upon increasing the feeding current beyond a certain threshold value, I C , we observe that the initial surface contour becomes unstable resulting in (i) drop oscillations (ii) electromagnetic pinching and (iii) static disc deformations. In each configuration the threshold value depends in a similar manner on the frequency of the applied magnetic field. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)