Prodn. of aluminium titanate ceramic - by calcining moulded body contg. alumina, titania, and additives contg. lanthanum

摘要

Prodn. of aluminium titanate ceramic (tialite) comprises calcining a moulded body of a mixt. of Al2O3, TiO2 and lanthanum-contg. additives and opt. other usual additives and/or unavoidable impurities at 1240 [deg]C or higher. The novelty is that: (a) the mixt. contains 0.1-3 (pref. 0.1-0.5) mol.% lanthanum titanate and 0.1-3 (pref. 0.4-1.0) mol.% Fe2O3. The Al2O3 has coarse grain size of 1-5 mu m at d10, 3-10 mu m at d50, 5-25 mu m at d90, and max. 45 mu m, and fine grain size of 0.5 mu m at d10, 0.4-1mu m at d50, 0.5-0.3 mu m at d90, and max. 8mu m. Ratio of fine Al2O3:coarse Al2O3 is 40-60:60-40. Calcination is carried out at 1300-1400 [deg]C. The aluminium titanate ceramic obtd. is also claimed, having a density of 3.25-3.45 g/cm3, a bending strength of 20-45 MPa, a V modulus of 3-15 GPa and a ratio of bending strength:V modulus of >= 0.3% of the crystals have a ratio of length to width of (5-15):1.