| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for casting a piston with which the development of blow hole is remarkably reduced and the piston can simply be cast and the cost is comparatively low. <P>SOLUTION: A cavity 2 is formed with an interval between respective metallic molds 1a, 1b and each of metallic molds 1a, 1b and a core, and semi-solidified molten metal M2 is supplied into the cavity. This semi-solidified molten metal M2 is the molten metal used for well-known semi-solidifying method and is obtained by cooling the liquid-state molten metal and becoming the semi-solidifying state. When this molten metal M2 is used, the entrapment of the air in the cavity 2 is remarkably lowered and further, since the solid portion is possessed at not less than the half part, e.g. in the semi-solidified molten metal M2 becoming about 60% of the solid, the blow hole is scarcely developed in the inner part. Further, since the temperature of the semi-solidified molten metal M2 becomes lower in comparison with the liquid state molten metal, the thermal affection to the metallic molds 1a, 1b is little and also, the cooling time of the molten metal in the cavity 2 can be shortened. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
