| 摘要 |
Zirconia ceramics containing substantial amounts of metastable tetragonal phase crystallites, so that they are tougher than most other ceramics, can be completely comminuted to powders, without applying any mechanical force, by treatment with water or steam at temperatures well above room temperature. This type of comminution is particularly useful for small, often hollow, spheres producing by rapidly solidifying melts of zirconia and a stabilizing oxide such as yttria. These spheres can be almost completely comminuted to a size suitable for wet vibratory milling by treatment for twenty-four hours at 250 C under sufficient steam pressure to maintain some liquid water in equilibrium. |
