PURPOSE: To provide a sintered body of a large size and intricate shape which can be internally chilled with a spheroidal graphite cast iron by increasing the ratio of TiO2 in an aluminum titanate ceramics within a specific range and adding oxide of Fe, Mn, etc., at a specific ratio thereto.
CONSTITUTION: This ceramics is the sintered body of the aluminum titanate ceramics which consists of an auxiliary material consisting, by weight, of 0.5 to 6% Fe2O3, 0.5 to 2% MnO2 of 0.5 to 2% Cr2O3 and a main material consisting of Al2O3 and TiO2 and has 0.97:1 to 0.8:1 molar ratio of the Al2O3 and the TiO2. Even if this sintered body is large in size, the internal chilling thereof with the spheroidal graphite cast iron having excellent high-temp. characteristics can be made and, therefore, the sintered body is adequate for use as the internal wall of the exhaust manihold of an internal combustion engine. The better result is obtd. as the ratio of the TiO2 is higher in terms of the prevention of the decomposition at a high temp. and catalyst effect. The soft structure is obtd. in the above-mentioned range. The oxide of the Mn and Cr suppresses grain growth, suppress the quantity of crack and prevents the segregation of different kinds of crystals.
OKASHIRO KOJI
SASAKI MANABU
