| 摘要 |
A ceramic composed of 1 to 15 percent of glass and 99 to 85 percent of a mixture of particulates is disclosed. The glass, present as a vitreous phase bonding the particulates into a dense, gas impervious structure, contains 45 to 80 percent of SiO2, 8 to 65 percent of CaO and MgO and not more than 15 percent of Al2O3. The particulates, which are finer than 15 microns in ultimate particle size, include Al2O3 and at least one of ZrO2, HfO2 and solid solutions of the two. The ceramics are subject to microcracking, which can be cured by refiring, or prevented by including particulate Y2O3 as a stabilizer. |
