| 摘要 |
PURPOSE:To provide the titled ceramic composed of Y2O3 and MgO at respective specific mol.% and ZrO2 constituting the remaining part, containing respective specific amounts of SiO2 and Al2O3 as impurities and containing fine tetragonal crystals and monoclinic crystals distributed in cubic crystal particle and usable at a high temperature over a long period. CONSTITUTION:A formed article having a composition of ZrO2-MgO-Y2O3 composed of 0.2-3mol.% of Y2O3, 5-10mol.% of MgO and remaining part of ZrO2 and containing <=0.5wt.% of SiO2 and <=1.5wt.% of Al2O3 as impurities is calcined at a low temperature (1,550-1,730 deg.C) to obtain the ZrO2-MgO-Y2O3 ceramic material of the present invention having three-phase structure composed of cubic phase, orthogonal phase and monoclinic phase, having reduced crystal particle size and containing fine orthogonal and monoclinic crystals precipitated in cubic crystal particle by the heat-treatment at 1,100-1,350 deg.C. The ceramic has stable and high strength and toughness in addition to the above-mentioned characteristics. |
