Abstract
The objective of this study is to conduct the design and analysis of electromagnetic stirrer for molten metals. Based upon the fundamental theory of Magneto-hydrodynamics, the Lorentz forces generated by the interactions between a magnetic field and electrical currents in the liquid metals are employed for driving the metals and preventing the formation of dendrite microstructures at the solidification stage. Initially, simulation software for solving electromagnetic filed has been used for finding the distributions of the magnetic field along the flow path with various crucible designs and adjustable current inputs. The simulated results have indicated that the inclusions of ferro-magnetic iron core and the reduction of the air-gap can both strengthen the magnetic field. In the experimental verifications, element Gallium is employed for the molten metals whereas electric voltage and frequency are controlled through an inverter to energize the electromagnetic stirrer process. A prototype electromagnetic stirrer has been built for experimenting the effects of geometric dimensions and excitation parameters in the rotating magnetic fields; and, the experimental results have shown that the basic principle of electromagnetic stirring is verified. Keyword：MHD，Electromagnetic Stirring，Lorentz Force.