Temperature character of electromagnetic levitation melting

Abstract

Utilizing the formula of electromagnetic force and input power, we have derived the expression of input power of a spherical sample for a general electromagnetic levitation inductor without including the current of the inducer. Combining the power dissipation model of the spherical sample in free-convection gas medium and the expression of input power without including the current of inducer, the relation between processing parameters of electromagnetic levitation and temperature of levitation sample is established. The electromagnetic melting of spherical (TbDy)Fe2 alloys under the protection of Ar is employed as an example to study the effect of processing parameters on the temperature of levitation sample obtained by numerical computation. According to computation results and the character of actual electromagnetic levitation, the methods to decrease the temperature of the levitation melted sample are obtained: i.e. reducing the radius of the levitation melted sample, employing low frequencies of the inducer, adjusting the position of the levitated sample to a position at which the lowest levitation melting temperature can be obtained, reducing the radius of the lower levitation coil, increasing the space interval between the upper stability controlling coil and the lower levitation coil, increasing the radius of the upper stability controlling coil, and increasing the turns of the upper stability controlling coil.