Abstract: Glass and glass ceramic compositions having at least a lithium disilicate crystalline phase, a petalite crystalline phase, and a residual glass phase along with methods of making the glass and glass ceramic compositions are described. The compositions are compatible with conventional rolling and float processes, are transparent or translucent, and have high mechanical strength and fracture resistance. Additionally, processes of 3D forming glass ceramic preforms having the glass ceramic composition discussed to produce glass ceramic articles are described. Further, the compositions are able to be chemically tempered to even higher strength glass ceramics that are useful as large substrates in multiple applications.

Abstract: A method for ceramming a glass article to a glass-ceramic includes placing a glass article into a heating apparatus, and heating the glass article to a first hold temperature at a first predetermined heating rate. The glass article is held at the first hold temperature for a first predetermined duration. The viscosity of the glass article is maintained within log viscosity ±1.0 poise during the first predetermined duration. The glass article is then heated from the first hold temperature to a second hold temperature at a second predetermined heating rate. The glass article is held at the second hold temperature for a second duration. A density of the glass article is monitored from the heating of the glass article from the first hold temperature through the second duration, and the second duration is ended when an absolute value of a density rate of change of the glass article is less than or equal to 0.10 (g/cm3)/min.

Abstract: A glass ceramic article including a lithium disilicate crystalline phase, a petalite crystalline phased, and a residual glass phase. The glass ceramic article has a warp (?m)<(3.65×10?9/?m×diagonal2) where diagonal is a diagonal measurement of the glass ceramic article in ?m, a stress of less than 30 nm of retardation per mm of glass ceramic article thickness, a haze (%)<0.0994t+0.12 where t is the thickness of the glass ceramic article in mm, and an optical transmission (%)>0.91×10(2-0.03t) of electromagnetic radiation wavelengths from 450 nm to 800 nm, where t is the thickness of the glass ceramic article in mm.

Abstract: A three dimensional glass ceramic article with a thickness between 0.1 mm and 2 mm, having a dimensional precision control of less than or equal to ±0.1 mm. A method for forming a three dimensional glass ceramic article including placing a nucleated glass article into a mold, and heating the nucleated glass article to a crystallization temperature, where the nucleated glass article is in the mold during the heating. Then, holding the nucleated glass article at the crystallization temperature for a duration sufficient to crystallize the nucleated glass article and form a three dimensional glass ceramic article, where the nucleated glass article is in the mold during the holding, and removing the three dimensional glass ceramic article from the mold.

Abstract: A glass ceramic article including a lithium disilicate crystalline phase, a petalite crystalline phased, and a residual glass phase. The glass ceramic article has a warp (?m)<(3.65×10?9/?m×diagonal2) where diagonal is a diagonal measurement of the glass ceramic article in ?m, a stress of less than 30 nm of retardation per mm of glass ceramic article thickness, a haze (%)<0.0994t+0.12 where t is the thickness of the glass ceramic article in mm, and an optical transmission (%)>0.91×10(2?0.03t) of electromagnetic radiation wavelengths from 450 nm to 800 nm, where t is the thickness of the glass ceramic article in mm.

Abstract: Glass stack configurations including a carrier plate, setter plates, and glass sheets for thermal treatment of the glass sheets to form glass ceramic articles are provided. The glass stacking configurations and components described herein are selected to improve thermal uniformity throughout a glass stack during ceramming processes while maintaining or even reducing the stresses in the resultant glass ceramic article. Accordingly, the glass ceramic articles made according to the various embodiments described herein exhibit improved optical qualities and less warp than glass ceramic articles made according to conventional processes. Various embodiments of carrier plates, setter plates, parting agent compositions, and methods of stacking glass sheets are described.

Abstract: A three dimensional glass ceramic article with a thickness between 0.1 mm and 2 mm, having a dimensional precision control of less than or equal to ±0.1 mm. A method for forming a three dimensional glass ceramic article including placing a nucleated glass article into a mold, and heating the nucleated glass article to a crystallization temperature, where the nucleated glass article is in the mold during the heating. Then, holding the nucleated glass article at the crystallization temperature for a duration sufficient to crystallize the nucleated glass article and form a three dimensional glass ceramic article, where the nucleated glass article is in the mold during the holding, and removing the three dimensional glass ceramic article from the mold.

Abstract: A method of modifying a substrate comprising an etching step comprising contacting one or more primary surfaces of a glass, glass-ceramic, or ceramic substrate with a solution for a time period of 20 minutes to 8 hours to generate one or more etched primary surfaces, the solution comprising over 10 percent by weight of one or more alkali hydroxides, the solution having a temperature within the range of 100° C. to 150° C., the substrate having a thickness between the primary surfaces that decreases during the time period by 5 ?m to 100 ?m at a rate of 2 ?m per hour or greater. The solution of the etching step does not comprise hydrogen fluoride. The one or more alkali hydroxides of the solution of the etching step can be sodium hydroxide (NaOH), potassium hydroxide (KOH), or a combination of both sodium hydroxide and potassium hydroxide.

Abstract: A glass ceramic article including a lithium disilicate crystalline phase, a petalite crystalline phased, and a residual glass phase. The glass ceramic article has a warp (?m)<(3.65×10?9/?m×diagonal2) where diagonal is a diagonal measurement of the glass ceramic article in ?m, a stress of less than 30 nm of retardation per mm of glass ceramic article thickness, a haze (%)<0.0994t+0.12 where t is the thickness of the glass ceramic article in mm, and an optical transmission (%)>0.91×10(2?0.03t) of electromagnetic radiation wavelengths from 450 nm to 800 nm, where t is the thickness of the glass ceramic article in mm.

Abstract: A glass ceramic article including a lithium disilicate crystalline phase, a petalite crystalline phased, and a residual glass phase. The glass ceramic article has a warp (?m)<(3.65×10?9/?m×diagonal2) where diagonal is a diagonal measurement of the glass ceramic article in ?m, a stress of less than 30 nm of retardation per mm of glass ceramic article thickness, a haze (%)<0.0994t +0.12 where t is the thickness of the glass ceramic article in mm, and an optical transmission (%)>0.91×10(2-0.03t) of electromagnetic radiation wavelengths from 450 nm to 800 nm, where t is the thickness of the glass ceramic article in mm.

Abstract: A method of modifying a substrate comprising an etching step comprising contacting one or more primary surfaces of a glass, glass-ceramic, or ceramic substrate with a solution for a time period of 20 minutes to 8 hours to generate one or more etched primary surfaces, the solution comprising over 10 percent by weight of one or more alkali hydroxides, the solution having a temperature within the range of 100° C. to 150° C., the substrate having a thickness between the primary surfaces that decreases during the time period by 5 ?m to 100 ?m at a rate of 2 ?m per hour or greater. The solution of the etching step does not comprise hydrogen fluoride. The one or more alkali hydroxides of the solution of the etching step can be sodium hydroxide (NaOH), potassium hydroxide (KOH), or a combination of both sodium hydroxide and potassium hydroxide.

Abstract: A three dimensional glass ceramic article with a thickness between 0.1 mm and 2 mm, having a dimensional precision control of less than or equal to ±0.1 mm. A method for forming a three dimensional glass ceramic article including placing a nucleated glass article into a mold, and heating the nucleated glass article to a crystallization temperature, where the nucleated glass article is in the mold during the heating. Then, holding the nucleated glass article at the crystallization temperature for a duration sufficient to crystallize the nucleated glass article and form a three dimensional glass ceramic article, where the nucleated glass article is in the mold during the holding, and removing the three dimensional glass ceramic article from the mold.

Abstract: A glass ceramic article including a lithium disilicate crystalline phase, a petalite crystalline phased, and a residual glass phase. The glass ceramic article has a warp (?m)<(3.65×10?6/?m×diagonal2) where diagonal is a diagonal measurement of the glass ceramic article in ?m, a stress of less than 30 nm of retardation per mm of glass ceramic article thickness, a haze (%)<0.0994t+0.12 where t is the thickness of the glass ceramic article in mm, and an optical transmission (%)>0.91×10(2-0.03t) of electromagnetic radiation wavelengths from 450 nm to 800 nm, where t is the thickness of the glass ceramic article in mm.

Abstract: A glass-ceramic article having one or more crystalline phases; a residual glass phase; a compressive stress layer extending from a first surface to a depth of compression (DOC); a maximum central tension greater than 70 MPa; a stored tensile energy greater than 22 J/m2; a fracture toughness greater than 1.0 MPa?m; and a haze less than 0.2.

Abstract: A method for ceramming a glass article to a glass-ceramic includes placing a glass article into a heating apparatus, and heating the glass article to a first hold temperature at a first predetermined heating rate. The glass article is held at the first hold temperature for a first predetermined duration. The viscosity of the glass article is maintained within log viscosity ±1.0 poise during the first predetermined duration. The glass article is then heated from the first hold temperature to a second hold temperature at a second predetermined heating rate. The glass article is held at the second hold temperature for a second duration. A density of the glass article is monitored from the heating of the glass article from the first hold temperature through the second duration, and the second duration is ended when an absolute value of a density rate of change of the glass article is less than or equal to 0.10 (g/cm3)/min.

Abstract: Glass stack configurations including a carrier plate, setter plates, and glass sheets for thermal treatment of the glass sheets to form glass ceramic articles are provided. The glass stacking configurations and components described herein are selected to improve thermal uniformity throughout a glass stack during ceramming processes while maintaining or even reducing the stresses in the resultant glass ceramic article. Accordingly, the glass ceramic articles made according to the various embodiments described herein exhibit improved optical qualities and less warp than glass ceramic articles made according to conventional processes. Various embodiments of carrier plates, setter plates, parting agent compositions, and methods of stacking glass sheets are described.

Abstract: A glass sheet is formed on a mold into a glass article having a three-dimensional shape. The mold, with the glass article thereon, is arranged within an interior space of a radiation shield such that the mold is between a leading end barrier and a trailing end barrier of the radiation shield. The mold, glass article, and radiation shield are translated through a sequence of cooling stations while maintaining the mold between the leading and trailing end barriers, wherein the leading and trailing end barriers inhibit radiation heat transfer at leading and trailing ends of the mold.

Abstract: A method of forming a shaped glass article includes placing a glass sheet on a mold such that a first glass area of the glass sheet corresponds to a first mold surface area of the mold and a second glass area of the glass sheet corresponds to a second mold surface area of the mold. The first glass area and the second glass area are heated such that the viscosity of the second glass area is 8 poise or more lower than the viscosity of the first glass area. A force is applied to the glass sheet to conform the glass sheet to the mold surface. During the heating of the second glass area, the first mold surface area is locally cooled to induce a thermal gradient on the mold.

Abstract: A method of forming a shaped glass article includes placing a glass sheet on a mold such that a first glass area of the glass sheet corresponds to a first mold surface area of the mold and a second glass area of the glass sheet corresponds to a second mold surface area of the mold. The first glass area and the second glass area are heated such that the viscosity of the second glass area is 8 poise or more lower than the viscosity of the first glass area. A force is applied to the glass sheet to conform the glass sheet to the mold surface. During the heating of the second glass area, the first mold surface area is locally cooled to induce a thermal gradient on the mold.

Abstract: Methods for compensating for the warp exhibited by three-dimensional glass covers as a result of ion exchange strengthening are provided. The methods use a computer-implemented model to predict/estimate changes to a target three-dimensional shape for the 3D glass cover as a result of ion exchange strengthening. The model includes the effects of ion exchange through the edge of the 3D glass cover. In an embodiment, the inverse of the predicted/estimated changes is used to produce a compensated (corrected) mold which produces as-molded parts which when subjected to ion exchange strengthening have shapes closer to the target shape than they would have had if the mold had not been compensated (corrected).