PROBLEM TO BE SOLVED: To provide a translucent zirconia sintered body that is excellent in light transmittance, hydrothermal deterioration resistance, and mechanical strength.SOLUTION: Provided is a zirconia sintered body comprising yttria by 6.5 to 10 mol% and alumina by 0.05 to 0.3 wt.% and in which the sum of the tetragonal crystal prime phase percentage and the cubic crystal phase percentage constitutes 90% or more, and the sintered body average particle≤1 μm or less and the light transmittance≥35% (600 nm, 1.0 mm thick), and said sintered body is obtained by sintering a compact of zirconia powder comprising yttria by 6.5 to 10 mol% and alumina by 0.05 to 0.3 wt.% and in which the yttria is in solid solution in the zirconia, and the BET: 6 to 15 m2/g and the average particle size≤0.7 μm, by increasing the temperature from 900°C at a speed of 50°C/hour or less and maintaining at 1170 to 1220°C for a predetermined period of time.COPYRIGHT: (C)2016,JPO&INPIT【課題】 光透過率、水熱劣化耐性、機械的強度に優れる透光性ジルコニア焼結体を提供する。【解決手段】イットリアを6.5~10モル%及びアルミナを0.05~0.3重量%含み、正方晶プライム相率と立方晶相率の和が90%以上からなり、焼結体平均粒≦1μm以下、光透過率≧35%(600nm、1.0mm厚)のジルコニア焼結体であり、該焼結体は、イットリアを6.5~10モル%及びアルミナを0.05~0.3重量%含み、該イットリアがジルコニアに固溶しており、BET:6~15m2/g、平均粒径≦0.7μmのジルコニア粉末の成形体を、900℃から50℃/時間以下の速度で昇温させて1170~1220℃で一定時間保持して焼結させて得る。【選択図】 なし
