amp;alpha;-ALUMINA FOR CORDIERITE CERAMIC, METHOD OF PRODUCING THE SAME, AND STRUCTURE OF CORDIERITE CERAMIC USING THE amp;alpha;-ALUMINA

摘要

PROBLEM TO BE SOLVED: To provide α-alumina usable for producing cordierite ceramics having a low coefficient of thermal expansion and high thermal shock resistance and exhibiting small variance in characteristics, and to provide a method of producing the α-alumina and a structure of the cordierite ceramics using the α-alumina.;SOLUTION: The α-alumina for the cordierite ceramics having a secondary particle size of 40 to 70 μm, a primary particle size of 1.5 to 3.0 μm and a BET specific surface area of 0.5 to 1.5 m²/g is pulverized by means of a jet mill. The pulverized α-alumina comprises alumina particles of ≤3 μm in an amount of ≤30 mass % and alumina particles of ≤15 μm in an amount of ≥75 mass % in relation to a particle size distribution profile of the α-alumina, and has a mean particle size of 4 to 10 μm and a +90 μm sieve residue of ≤50 ppm by mass.;COPYRIGHT: (C)2003,JPO