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. % SiO2; from 7 mol. % to 25 mol. % Al2O3; from 2 mol. % to about 14 mol. % Li2O; 0.4 mol. % P2O5; and less than or equal to 0.5 mol. % ZrO2. The quantity (Al2O3 (mol. %)-R2O (mol. %)-RO (mol. %)) is greater than zero, where R2O (mol. %) is the sum of the molar amounts of Li2O, Na2O, K2O, Rb2O, and Cs2O 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 (Li2O (mol. %))/(R2O (mol. %)) may be greater or equal to 0.5. In embodiments, the glass composition may include B2O3. The glass compositions are fusion formable and have high damage resistance.
Abstract:
Isopipes (13) for making glass sheets using a fusion process are provided. The isopipes are made from alumina materials which have low levels of the elements of group IVB of the periodic chart, i.e., Ti, Zr, and Hf, as well as low levels of Sn. In this way, the alumina isopipes can be used with glasses that contain tin (e.g., as a fining agent or as the result of the use of tin electrodes for electrical heating of molten glass) without generating unacceptable levels of tin-containing defects in the glass sheets, specifically, at the sheets' fusion lines. The alumina isopipes disclosed herein are especially beneficial when used with tin-containing glasses that exhibit low tin solubility, e.g., glasses that have (RO+R2O)/Al2O3 ratios between 0.9 and 1.1, where, in mole percent on an oxide basis, (RO+R2O) is the sum of the concentrations of the glass' alkaline earth and alkali metal oxides and Al2O3 is the glass' alumina concentration.
Abstract:
A method of making a glass sheet includes exposing a refractory block material comprising at least one multivalent component to a reducing atmosphere for a time and at a temperature sufficient to substantially reduce the at least one multivalent component of the refractory block material. The method also includes flowing molten glass over the refractory block material that has been exposed to the reducing atmosphere while preventing substantial re-oxidation of the at least one multivalent component.
Abstract:
Ion exchangeable glass compositions that develop concentration profiles and stress profiles that have higher magnitudes of concentration and compressive stress profiles than those provided by the error function (erfc)-shaped compressive stress profile for similar surface concentrations of stress-inducing components such as K+ or K2O and stresses. The advantaged stress profile is the result of a glass composition that is low in K2O (or potassium) in the base glass prior to ion exchange. A glass comprising lower amounts of K+ or K2O has a stronger dependence of diffusivity on concentration, leading to a non-erfc-shaped concentration profile. Several glass compositions that contain low amounts of K+ or K2O exhibit this beneficial effect, whereas other glasses containing higher amounts of K+ or K2O do not exhibit this effect.
Abstract:
A method of making a glass sheet includes exposing a refractory block material comprising at least one multivalent component to a reducing atmosphere for a time and at a temperature sufficient to substantially reduce the at least one multivalent component of the refractory block material. The method also includes flowing molten glass over the refractory block material that has been exposed to the reducing atmosphere while preventing substantial re-oxidation of the at least one multivalent component.
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. % SiO2; from 7 mol. % to 25 mol. % Al2O3; from 2 mol. % to about 14 mol. % Li2O; 0.4 mol. % P2O5; and less than or equal to 0.5 mol. % ZrO2. The quantity (Al2O3 (mol. %)−R2O (mol. %)−RO (mol. %)) is greater than zero, where R2O (mol. %) is the sum of the molar amounts of Li2O, Na2O, K2O, Rb2O, and Cs2O 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 (Li2O (mol. %))/(R2O (mol. %)) may be greater or equal to 0.5. In embodiments, the glass composition may include B2O3. The glass compositions are fusion formable and have high damage resistance.
Abstract:
A method of making a glass sheet includes treating a refractory block material comprising at least one multivalent component with a vehicle comprising at least one redox altering component or precursor. The method also includes flowing molten glass over the refractory block material, wherein the treatment of the refractory block material with the vehicle comprising at least one redox altering component or precursor reduces the amount of oxygen production resulting from interaction between the at least one multivalent component and the molten glass.
Abstract:
A glass that is down-drawable and ion exchangeable. The glass has a temperature T35kp which the viscosity is 35 kilopoise. T35kp is less than the breakdown temperature Tbreakdown of zircon.
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. % SiO2; from 7 mol. % to 25 mol. % Al2O3; from 2 mol. % to about 14 mol. % Li2O; 0.4 mol. % P2O5; and less than or equal to 0.5 mol. % ZrO2. The quantity (Al2O3 (mol. %)-R2O (mol. %)-RO (mol. %)) is greater than zero, where R2O (mol. %) is the sum of the molar amounts of Li2O, Na2O, K2O, Rb2O, and Cs2O 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 (Li2O (mol. %))/(R2O (mol. %)) may be greater or equal to 0.5. In embodiments, the glass composition may include B2O3. The glass compositions are fusion formable and have high damage resistance.
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. % SiO2; from 7 mol. % to 25 mol. % Al2O3; from 2 mol. % to about 14 mol. % Li2O; 0.4 mol. % P2O5; and less than or equal to 0.5 mol. % ZrO2. The quantity (Al2O3 (mol. %)-R2O (mol. %)-RO (mol. %)) is greater than zero, where R2O (mol. %) is the sum of the molar amounts of Li2O, Na2O, K2O, Rb2O, and Cs2O 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 (Li2O (mol. %))/(R2O (mol. %)) may be greater or equal to 0.5. In embodiments, the glass composition may include B2O3. The glass compositions are fusion formable and have high damage resistance.