TRANSPARENT HEXAGONAL STUFFED β–QUARTZ GLASS-CERAMIC ARTICLES HAVING LARGE GRAIN SIZE

摘要

A glass-ceramic article includes 50 mol.% to 80 mol.% SiO₂; 10 mol.% to 25 mol.% Al₂O₃; 5 mol.% to 20 mol.% MgO; 0 mol.% to 10 mol.% Li₂O; and 1 mol.% to 3 mol.% of a nucleating agent. The nucleating agent is selected from the group consisting of ZrO₂, TiO₂, SnO₂, HfO₂, Ta₂O₅, Nb₂O₅, Y₂O₃, and combinations thereof. The nucleating agent may comprise greater than or equal to 50% ZrO₂ and less than 50% of at least one compound selected from the group consisting of TiO₂, SnO₂, HfO₂, Ta₂O₅, Nb₂O₅, Y₂O₃, and combinations thereof. The glass-ceramic article may have a molar ratio of MgO to Li₂O of greater than or equal to 1:1. The glass-ceramic article may satisfy the relationship 0.85≤ (MgO (mol%) + Li₂O (mol%))/Al₂O₃ (mol%) ≤ 1.2. The glass-ceramic article may comprise a crystalline phase comprising hexagonal stuffed β–quartz and glass.