Corning Incorporated
PERALUMINOUS LITHIUM ALUMINOSILICATES WITH HIGH LIQUIDUS VISCOSITY

Abstract:

The embodiments described herein relate to glass articles that include mechanically durable glass compositions having high liquidus viscosity. The glass articles may include glass compositions having from 50 mol. % to 80 mol. % SiO.sub.2; from 7 mol. % to 25 mol. % Al.sub.2O.sub.3; from 2 mol. % to about 14 mol. % Li.sub.2O; 0.4 mol. % P.sub.2O.sub.5; and less than or equal to 0.5 mol. % ZrO.sub.2. The quantity (Al.sub.2O.sub.3 (mol. %)-R.sub.2O (mol. %)-RO (mol. %)) is greater than zero, where R.sub.2O (mol. %) is the sum of the molar amounts of Li.sub.2O, Na.sub.2O, K.sub.2O, Rb.sub.2O, and Cs.sub.2O in the glass composition and RO (mol. %) is the sum of the molar amounts of BeO, MgO, CaO, SrO, BaO, and ZnO in the glass composition. A molar ratio of (Li.sub.2O (mol. %))/(R.sub.2O (mol. %)) may be greater or equal to 0.5. In embodiments, the glass composition may include B.sub.2O.sub.3. The glass compositions are fusion formable and have high damage resistance.