Using Electromagnetic Levitation for Continuous Casting of Thin Aluminium Alloys Strip

The paper presents a method for computing the parameters of an electromagnetic mould for a horizontal continuous casting of thin aluminium alloys strip. The method is based on the calculation of the distribution of the magnetic field, which is based on the interaction between the inductor and the surface of the shaped molten metal. The interaction of fields of the inductor and its mirror image in the molten metal moves the centres of the electrical current flow closer together and increases the current density at the inductor's face adjacent to the liquid metal. The operating frequency of alternating current flowing through the inductor, which depends on the density, the surface tension, and specific electrical conductivity of the liquid metal, and the pool thickness, is determined. The mould was designed for the electromagnetic levitation a free surface of 150 × 20 mm strip from AlSi8.5Cu and AlSn20 alloys. It consists of a system of special inductors which are of the different configurations for shaping the upper and lower surfaces. At the inductor's width of 28 mm, the uniform magnetic field ensuring the steady air gap between the inductor and the liquid metal can be expected over the length of 24 mm.