| 摘要 |
The present invention relates to novel glass and glass-ceramic materials, articles made from said novel glass-ceramic and to methods of preparing said novel glass-ceramics and articles. Said novel, transparent, translucent or opaque glass-ceramics, which contain, as main crystalline phase, a solid solution of beta-quartz or of beta-spodumene, essentially have the following composition, expressed as percentages by weight of oxides: 65 to 70% of SiO2; 18 to 23% of Al2O3;>4 to 5% of Li2O; 0 to <1% of MgO; 1 to 3% of ZnO; 0 to 2% of BaO; 1.8 to 4% of TiO2; 1 to 2.5% of ZrO2; 0.4 to 1% of K2O and/or Na2O; with, advantageously, an effective and non-excess amount of at least one fining agent. The glass-ceramic material is alse characterized by a water content of beta-OH higher than 0.2 mm<-1>, preferably higher than 0.4 mm<-1>. |
