| abstract |
The conventional polycrystalline sintered body of zirconia having transparency requires an additive such as titania. In the sintered body containing such an additive, plasma resistance, refractive index, strength, etc. There was a problem. A primary sintered body having a density of 95% or more obtained by pressure-sintering zirconia powder mainly composed of yttria as a stabilizer is placed in a semi-sealed container at a temperature of 1600 to 1900 ° C. and a pressure of 50 MPa or more. Then, a zirconia polycrystalline sintered body having a high transparency with a linear transmittance of 50% or more is manufactured by performing a HIP treatment (secondary sintering) and, if necessary, a heat treatment in an oxidizing atmosphere. [Selection] Figure 1 |