CASTING METHOD OF TITANIUM CASTING CONSISTING OF PURE TITANIUM OR ALLOY CONSISTING ESSENTIALLY OF TITANIUM

摘要

PURPOSE:To obtain Ti castings with virtually no oxidation by using MgO molding materials only for the parts of the walls of casting molds where the walls contact with Ti casting materials and maintaining the Ti casting materials which are chrged into the casting molds at a specified temp. or below. CONSTITUTION:Parts 13A of the walls of a casting mold 13 for casting of a Ti casting material with an automatic precision casting machine where the walls contact with the material 3 are molded of pure MgO or MgO molding materials consisting essentially of MgO. The parts 13B except said parts are molded of molding materials consisting of materials differeing from the MgO molding materials. The material 3 is melted in a crucible 5 in an oxygen-free atmosphere, and while the oxygen-free atmosphere is maintained, the melt of the material 3 is charged into the casting mold 13. At least the parts 13A of the mold 13 are held from the beginning at the temp. at which the oxide forming energy of the material 3 attains the value larger than the MgO forming energy during the formation of MgO or is cooled quickly down to said temp. Thus, the Ti castings, which are not oxidized virtually or completely, are obtained.