| 摘要 |
PROBLEM TO BE SOLVED: To provide a zirconia sintered body excellent in strength and toughness as well as water heat degradation resistance.SOLUTION: A zirconia sintered body yttria concentration containing 0.05 to 3 wt.% of alumina of 2 to 4 mol% with a relative density of the zirconia sintered body of 99.7% or more, an average particle diameter of crystal particles of 0.1 to 0.3 μm, flexure strength of 1600 MPa or more and monoclinic phase rate after immersing in hot water at 140°C for 75 hours of 5% or less is used. The sintered body is obtained by molding zirconia particles having the average particle diameter of secondary particles of 0.1 to 0.4 μm, a ratio of the average particle diameter of the secondary particles/the average particle diameter of primary particles measured by an electron microscope of 1 to 8 and yttria concentration containing 0.05 to 3 wt.% of alumina of 2 to 4 mol% and pre-sintering it at 1100 to 1200°C and conducting hot rolling isostatic press treatment on obtained pre-sintered body at pressure of 50 to 500 MPa and temperature of 1150 to 1250°C. |
