Plastic-worked member and production method thereof

摘要

A metal ingot (1) solidified through unidirectional forced-cooling from a cooling member (100) to an end surface of a stopper (13), by the cooling member, of molten metal (1') teeming via a molten metal inlet (101) of a closable mold (12) into a mold cavity (16) is plastic-worked at percent working equl to or higher than a predetermined level to obtain a plastic-worked member. The end surface of the stopper and the cooling member partially define the mold cavity. The plastic-worked member is improved in mechanical characteristics that have heretofore been inferior on the side of the end surface of the stopper and is increased in entire strength.