The effects of electromagnetic stirring on the morphology of primary
α phase in an Al-7%Si alloy are studied using a cold crucible type stirring method. The isothermal holding test reveals that the grain size of
α phase increases as the holding time increases. Time growth rate of the grain size is well explained by the Ostwald ripening theory. The growth rate is larger than that of previous work in which electromagnetic stirring is not used. In case of the continuous cooling, the granular shape of
α phase is obtained by cooling from temperature near liquidus with or without electromagnetic stirring. In case of cooling from 993K, the granular shape of
α phase is obtained by cooling down to near liquidus temperature (893K) with electromagnetic stirring and cooling down to room temperature without electromagnetic stirring. The grain size of the
α phase increases as the cooling rate decreases. The effect of the electromagnetic stirring on the grain size of
α phase is smaller than that of the cooling rate.
抄録全体を表示