Abstract
The mixed powder of ZrO2(3Y) and Al2O3 was ground by a bead milling method. The particle sizes of ZrO2(3Y) and Al2O3 were reduced to 10 nm and 18 nm by milling for 377 hours, respectively. Open pores in the specimen sintered at 1300°C were diminished to less than 0.1% of total volume for fine mixed powder milled for 422 hr, while open pores in the specimen sintered at the same conditions using mixed powder milled for 1 hr showed more than 17%. Therefore, it was concluded that the reduction of particle size mentioned above greatly enhanced the sinterability of the mixed powder. The relative density reached more than 99.7% of theoretical density when the pre-sintered bodies free from open pores were HIP'ed at temperatures from 1300°C to 1500°C under Ar gas pressure of 196 MPa. The bending strength of the HIP'ed specimen was 1520 MPa although that of pre-sintered specimen was 800 MPa.
