Solidified Structure Comparison under Imposition of Oscillating Electromagnetic Force and DC Electromagnetic Force

摘要

Experimental work has been done to investigate difference of structures solidified under the imposition of an oscillating electromagnetic force and that under the imposition of a DC electromagnetic force. For excitation of the oscillating electromagnetic force, a static magnetic field and an alternating current are simultaneously imposed on a Sn-10mass%Pb alloy while the static magnetic field and a direct current are simultaneously imposed on the alloy for the excitation of the DC electromagnetic force. After the solidification, macrostructure is observed and it is concluded that both the electromagnetic forces have refining function of the solidified structure. Though magnitude of the DC force is weaker than that of the oscillating force, grain size solidified under the imposition of the DC force is smaller than that solidified under the imposition of the oscillating force. Nucleation is not induced under the imposition of the DC force while it is induced when the oscillating force is imposed on the alloy.