PURPOSE: To improve the heat radiation of a casting mold and to accelerate the unidirectional solidification of a super alloy by coating the powder of the lower oxide of titanium, more preferably the lower oxide of titanium which is blackened and has high emissivity on the outside layer part of a shell mold for casting.

CONSTITUTION: Titanium is heated to about ≥1,000°C in a reducing atmosphere to release oxygen in TiO2 and to change the same to lower oxide, thereby yielding blackened TiO1.75WTiO1.65. The above-mentioned lower oxide is then coated on the outside layer of a casting mold with a binder consisting of butyl titanate and is calcined at a high temp. to complete an investment casting mold having the outside layer of high emissivity. The conversion to the lower oxide of titania can be accomplished in the process of manufacturing the casting mold as well. The heat radiatability of the titled casting mold is thus improved and the temp. gradient of the solid-liquid boundary during unidirectional solidification of the super alloy is increased and the crystal growth in the prior bearing direction of the alloy is accelerated.