Abstract
Most of the work reported concerned the semi-solid processing of low melting point alloys, and in particular light alloys of aluminum and magnesium. The purpose of this paper is to develop a semi-solid microstructure of Cu alloys using electromagnetic stirring applicable for squirrel cage rotor of induction motor. The size of primary solid particle and the degree of sphericity as a function of the variation in cooling rate, stirring speed, and holding time were observed. By applying electromagnetic stirring, primary solid particles became finer and rounder relative to as-cast sample. As the input frequency increased from 30 to 40 Hz, particle size decreased. The size of primary solid particle was found to be decreased with increasing cooling rate. Also, it decreased with stirring up to 3 minutes but increased above that point. The degree of sphericity became closer to be 1 with hold time. Semi-solid microstructure of Cu alloys, one of the high melting point alloys, could be controlled by electromagnetic stirring.
