PRODUCTION OF CASTING HAVING FINE CRYSTAL STRUCTURE

摘要

PURPOSE:To directionally solidify the molten metal in a main casting mold and to obtain a good-quality casting having fine secondary dendrite spacings by pouring the molten metal into the heated main casting mold and auxiliary casting mold having prescribed shapes and solidifying the molten metal in the auxiliary casting mold by force cooling then removing the same. CONSTITUTION:The molten metal 4 is poured into the main casting mold 1 heated by heating means 2 and the auxiliary casting mold 3 provided to the bottom thereof. The auxiliary casting mold 3 is quickly cooled by cooling water 8 so that the molten metal 4 in the auxiliary casting mold 3 is solidified by the force cooling. The molten metal 4 in the main casting mold 1 solidifies by having directivity from below and forms the fine-grained structure having the fine secondary dendrite spacings. The quality of the casting is thus improved. The auxiliary molding casting mold part 5 may be taken out and cut off after the solidification of the entire part.