Die-casting method and die-castings obtained thereby

Abstract

A die casting method and a casting that is obtained through use of the die casting method. The die casting method can solve problems such as air catching occurring at the time of injection into the cavity of a die and molten metal run defect, thereby enabling efficient production of defect-free perfect castings. Via a mouth piece and a molten-metal feed port , molten metal from a molten metal feeder flows into a casting sleeve while undergoing laminar flow. When the molten metal reaches a predetermined level, a plunger tip is moved upward within the casting sleeve and stops at a position where the side surface of the plunger tip closes the molten-metal feed port . The molten metal that has flowed into the casting sleeve is cooled by a cooling medium flowing through passages formed within the casting sleeve so that said molten metal forms primary crystals. Simultaneously, through use of a high frequency coil , the molten metal is subjected to electromagnetic agitation. As a result, the molten metal is fluidized and soaked. At this time, the temperature of the molten metal is detected by a sensor. When it is judged that the solid phase ratio has reached an arbitrary value in the range of 10-60%, the plunger tip is moved upward in order to inject the semi-solidified molten metal into the cavity of a die