Patent ID: 6753284
Filing Date: 2004-06-22
Classification: C04B

Abstract:
A sintered alumina ceramic substantially consisting of alumina, ReAlO3 and Re3Al5O12 wherein:the alumina particles contained in the sintered ceramic have an average particle size of 4.0 &mgr;m or smaller and more than 1 &mgr;m; the total content of alkali metal elements, alkaline earth metal elements, Si, and Ti, as convened to oxides, account for 0.1 mol or less per 100 mol of alumina contained in the sintered ceramic; and the total peak intensity for the principal peaks for ReAlO3 and Re3Al5O12, where Re is a Group 3A metal of Periodic Table, with respect to the intensity of the principal peak of alumina as measured by X-ray diffraction and calculated according to the following equation fall in a range of from 1 to 75%: (A+B)100/C where: A is the peak intensity of the (112) diffraction peak of ReAlO3, B is the peak intensity of the (420) diffraction peak of Re3Al5O12, and C is the peak intensity of the (113) diffraction peak of alumina.