PROBLEM TO BE SOLVED: To provide a zirconia sintered compact having a high sintered compact density and strength and excellent light transmitting feeling, which is produced without needing specific sintering such as HIP sintering.SOLUTION: The light transmitting zirconia sintered compact comprising zirconia containing 2-4 mol% of yttria as a stabilizer and less than 0.1 wt.% of alumina as an additive, and having a relative density of 99.8% or more and a light transmittance at a thickness of 1.0 mm of 35% or more is produced by normal pressure sintering. It is preferable to sinter a powder containing alumina in an amount less than 0.1 wt.%, and having a BET specific surface area of 10 to 15 m2/gm, an average particle diameter of 0.4 to 0.7 μm, and a sintering shrinkage rate (▵ρ/▵T:g/cm3 °C) during normal pressure sintering (in the atmosphere, temperature raising rate: 300°C/h) of 0.0125 to 0.0160 at a normal pressure in the atmosphere.COPYRIGHT: (C)2015,JPO&INPIT【課題】焼結体密度及び強度が高く、透光感に優れるジルコニア焼結体の製造にはHIP焼結等の特殊な焼結が必要であった。【解決手段】安定化剤として2~4mol%のイットリアを含み、添加剤としてアルミナを0.1wt%未満含むジルコニアからなり、相対密度が99.8%以上、かつ厚さ1.0mmでの全光線透過率が35%以上の透光性ジルコニア焼結体を常圧焼結によって製造する。アルミナを0.1wt%未満含むBET比表面積が10~15m2/gm、平均粒径が0.4~0.7μmの粉末で、常圧焼結(大気中、昇温速度300℃/時)における焼結収縮速度(△ρ/△T:g/cm3・℃)が0.0125以上0.0160以下の粉末を大気中で常圧焼結することが好ましい。【選択図】図1
