Abstract
In order to improve the surface quality of ingots fabricated by an electromagnetic casting, a header which restrains the growth and the movement of oxide films was set on the side free surface of a molten metal constrained by an electromagnetic force. The shapes and the materials of the header were examined under aluminum alloy castings. It is noticed that an electrically conducting graphite header provided the better surface qualities regarding the roughness and the thickness of oxide films than an electrically insulating refractory header did. The electromagnetic force and the velocity distribution in a molten metal are numerically calculated and the surface qualities obtained in the experiment are discussed in relation with the numerical results. It is found that a contacting pressure between a molten metal and the header is larger in graphite header than that in the refractory one and the molten metal just below the side free surface flows upward in the graphite header and downward in the refractory one.
