Semisolid high-speed roll casting was developed to improve the ductility of recycled aluminum alloys and aluminum alloys for casting. High-speed roll casting (high productivity) and rapid solidification could be realized using copper rolls, without using a parting material on the roll and at a low pouring temperature of molten metal. As a result, a semisolid strip could be continuously cast at a high speed. The casting speeds (rotation speeds of rolls) in this study were 20, 30 and 60 m/min. Detoxifying the Fe impurity included in recycled aluminum alloys from the outer and inner panels of automobiles was attempted by refining the impurity by rapid solidification. The detoxification of the Fe impurity was shown from results of tensile testing, bending and deep drawing. The possibility of sheet forming of aluminum alloys for casting was shown using deep drawing and three-roll bending. Eutectic Si of aluminum for casting was also refined by rapid solidification. Deep drawing with a limiting drawing ratio greater than 1.7 and three-roll bending were possible using by aluminum alloys for casting. It is shown in this study that the ductility of strips of recycled aluminum alloys and aluminum alloys for casting could be improved by semisolid high-speed roll casting.
Toshio HAGA (Tue,) studied this question.