Damping behavior of disturbance on liquid metal surface submerged in an intermittent alternating magnetic field

摘要

In several material processes, stability of the free surface of a molten metal is important for producing high quality materials. The imposition of magnetic field on a molten metal was introduced as a efficacious mean controlling the free surfaceof a molten metal. Several investigators have verified that static and high frequency magnetic fields enable the suppression of the disturbance given on the free surface of a molten metal. However, it is not clear whether an intermittent alternatingmagnetic field has the suppression function as well as the static and high frequency magnetic fields.In this work, the possibility of the suppression of the disturbance on free surface through the periodical wave motion excited by the intermittent alternating magnetic field has been explored in an experiment. The surface behavior of the molten galliumdisturbed by the impact of a steel ball has been observed under the continuous or the intermittent alternating magnetic field. It has been found that the damping period of the disturbance under the imposition of the intermittent alternating magnetic field is shorter than those under the continuous alternating magnetic field and no magnetic field.