Patent ID: 6848496
Filing Date: 2005-02-01
Classification: B22D

Abstract:
1. A gravity die casting apparatus for performing a casting while an oxide film formed on a surface of a molten metal is reduced by allowing the molten metal and a reducing compound to be contacted with each other, comprising: a metallic molding die having a cavity for receiving the molten metal, a sprue from which the molten metal is poured and a feeder head portion arranged between the sprue and the cavity, wherein a difference of heat insulation is partially provided between the feeder head portion and the cavity such that the molten metal filled in the cavity and the feeder head portion is sequentially solidified in a direction of from a terminal portion of the cavity to the feeder head portion, wherein surface areas of the feeder head portion, being different than a body of the feeder head portion, have a thermal conductivity which provides a cooling rate of molten metal poured into the feeder head portion of about 500° C./mm. or less, and surface areas of the cavity have a thermal conductivity which provides a cooling rate of the molten metal filled in an area of the cavity of about 500° C./min. or more.