摘要 |
A transparent, translucent or opaque vitroceramic, containing a solid solution of beta -quartz or beta -spodumene as its main crystalline phase, has the following composition expressed by wt of oxides: (A) 65 to 70 % of SiO 2; (B) 18 to 23 % of Al 2O 3; (C) greater than 4 to 5 % of LiO 2; (D) 0 to less than 1 % of MgO; (E) 1 to 3 % of ZnO; (F) 0 to 2 % of BaO: (G) 1.8 to 4 % of TiO 2; (H) 1 to 2.5 % of ZrO 2; (I) 0.4 to 1 % of K 2O and/or Na 2O; (J) with, advantageously, an effective and non-excessive quantity of at least one refining agent. Independent claims are also included for (A) a crystallisable glass mineral precursor of the vitroceramic; (B) an article made of the vitroceramic; (C) the production of the vitroceramic; (D) the production of the vitroceramic article. |