ALUMINA-BASED SINTERED BODY AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an alumina-based sintered body which ensures variation of dielectric loss tangent according to difference in position and a method for manufacturing the same.SOLUTION: An AlOcontent in an alumina-based sintered body is included in a range of 99.4-99.8 mass% and an Si content is included in a range of 0.11-0.38 mass% (expressed in terms of SiO). Deviation of crystal grain diameter in each of a surface layer portion and an interior portion is ≤0.06 [μm] and deviation of occupancy of crystals having a grain diameter of ≥6.5 [μm] in each of the surface layer portion and the interior portion is ≤0.6%.