| 摘要 |
A method for producing a ceramic is disclosed. The method involves comminuting a batch composed of from 6 to 95 percent of particulate ZrO2 and from 5 to 94 percent of particulate Al2O3. A part of the particulate ZrO2 is in a metastable tetragonal crystal structure, for example, as a consequence of 3m/o of Y2O3 dissolved therein and a part has a monoclinic crystal structure. The comminuted batch is compacted into a shape, and the shape is fired. The degree of comminution of the batch, the firing conditions and the proportions of stabilized and monoclinic ZrO2 in the batch are controlled to produce a dense, gas impervious ceramic which contains both metastable tetragonal and monoclinic ZrO2, and in such proportions that the ceramic has improved strength by comparison with an otherwise identical ceramic wherein all of the ZrO2 is in either a metastable tetragonal or a monoclinic crystal structure. Also disclosed is a method where the particulate alumina can be an alumina-chromia solid solution containing up to 50 m/o of chromia. In another embodiment, a ceramic article is disclosed. The article is composed of from 6 to 95 percent of particulate ZrO2, from 5 to 94 percent of particulate Al2O3, from 1/4 to 33/4 percent of MnO2 and from 1/4 to 33/4 percent of TiO2. |
