Glass compositions and glass articles formed therefrom having improved mechanical durability

Abstract

A glass composition includes: greater than or equal to 20 mol% and less than or equal 60 mol% SiO2; greater than or equal to 15 mol% and less than or equal to 40 mol% Al2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 0.05 mol% and less than 13.3 mol% MgO. Another glass composition includes: greater than or equal to 20 mol% and less than or equal 46 mol% SiO2; greater than or equal to 15 mol% and less than or equal to 40 mol% Al2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 13.3 mol% and less than or equal to 26 mol% MgO.

Description

GLASS COMPOSITIONS AND GLASS ARTICLES FORMED THEREFROM HAVING IMPROVED MECHANICAL DURABILITYCross-reference to Related Applications

[0001] This application claims the benefit of priority of U.S. Provisional Application Serial No. 63 / 633,265, filed on April 12, 2024, the content of which is relied upon and incorporated herein by reference in its entirety.Field

[0002] The present specification generally relates to glass compositions and, in particular, to glass compositions having improved mechanical durability.Technical Background

[0003] Glass articles, such as cover glasses, glass backplanes, housings, and the like, are employed in both consumer and commercial electronic devices, such as smart phones, smart watches, and tablets. The mobile nature of these portable devices makes the devices and the glass articles included therein particularly vulnerable to accidental drops on hard surfaces, such as the ground. Moreover, glass articles, such as cover glasses, may include “touch” functionality, which necessitates that the glass article be contacted by various objects including a user’s fingers and / or stylus devices. The glass articles, therefore, must be sufficiently robust to endure accidental dropping and regular contact without damage, such as scratching. Additionally, when dropped, the glass article may forcefully fragment, causing damage and negatively impacting the functionality of the device.

[0004] Accordingly, a need exists for alternative glasses with improved mechanical properties.SUMMARY

[0005] According to a first aspect Al, a glass composition comprises: greater than or equal to 20 mol% and less than or equal 60 mol% SiCb; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol%Y2O3; and greater than or equal to 0.05 mol% and less than 13.3 mol% MgO, wherein a total sum of concentrations of oxide components in the glass composition is equal to 100 mol%.

[0006] A second aspect A2 includes the glass composition of the first aspect Al, wherein the glass composition comprises greater than or equal to 14 mol% and less than or equal to 18 mol% Y2O3.

[0007] A third aspect A3 includes the glass composition of the first aspect Al or the second aspect A2, wherein the glass composition comprises greater than or equal to 0.1 mol% and less than or equal to 11 mol% MgO.

[0008] A fourth aspect A4 includes the glass composition of any one of the first through third aspects Al -A3, wherein the glass composition comprises greater than or equal to 25 mol% and less than or equal to 55 mol% SiO2.

[0009] A fifth aspect A5 includes the glass composition of any one of the first through fourth aspects A1-A4, wherein the glass composition comprises greater than or equal to 17 mol% and less than or equal to 35 mol% AI2O3.

[0010] A sixth aspect A6 includes the glass composition of any one of the first through fifth aspects A1-A5, wherein the glass composition comprises greater than or equal to 0.1 mol% and less than or equal to 25 mol% ZrCh.

[0011] A seventh aspect A7 includes the glass composition of any one of the first through sixth aspects A1-A6, wherein the glass composition comprises greater than or equal to 0.5 mol% and less than or equal to 25 mol% Nl^Os.

[0012] An eighth aspect A8 includes the glass composition of any one of the first through seventh aspects A1-A7, wherein the glass composition comprises greater than or equal to 0.5 mol% and less than or equal to 25 mol% Ta2Os.

[0013] A ninth aspect A9 includes the glass composition of any one of the first through eighth aspects A1-A8, wherein Y2O3 + MgO + ZrO2 + Nl^Os + Ta2Os is greater than or equal to 12.5 mol% and less than or equal to 45 mol%.

[0014] A tenth aspect A10 includes the glass composition of any one of the first through ninth aspects A1-A9, wherein the glass composition comprises greater than or equal to 1 mol% and less than or equal to 20 mol% U2O.

[0015] An eleventh aspect Al l includes the glass composition of any one of the first through tenth aspects A1-A10, wherein the glass composition comprises greater than 0 mol% and less than or equal to 20 mol% Na2O.

[0016] A twelfth aspect Al 2 includes the glass composition of any one of the first through eleventh aspects Al -Al 1, wherein the glass composition comprises greater than 0 mol% and less than or equal to 20 mol% CaO.

[0017] A thirteenth aspect Al 3 includes the glass composition of any one of the first through twelfth aspects Al -Al 2, wherein the glass composition comprises greater than or equal to 0.1 mol% and less than or equal to 5 mol% B2O3.

[0018] A fourteenth aspect Al 4 includes the glass composition of any one of the first through thirteenth aspects A1-A13, wherein the glass composition is free or substantially free of TiCh.

[0019] A fifteenth aspect Al 5 includes the glass composition of any one of the first through fourteenth aspects Al -Al 4, wherein the glass composition comprises a liquidus temperature greater than or equal to 1200 °C.

[0020] According to a sixteenth aspect Al 6, a glass article includes the glass composition of any one of the first through fifteenth aspects Al -Al 5.

[0021] A seventeenth aspect Al 7 includes the glass article of the sixteenth aspect Al 6, wherein the glass article comprises a Young’s modulus greater than or equal to 100 GPa, as measured using resonant ultrasound spectroscopy in accordance with ASTM C623.

[0022] According to an eighteenth aspect Al 8, a consumer electronic device comprises: a housing having a front surface, a back surface, and side surfaces; and electrical components provided at least partially within the housing, the electrical components including at least a controller, a memory, and a display, the display being provided at or adjacent the front surface ofthe housing; wherein the display includes the glass article of the sixteenth aspect Al 6 or the seventeenth aspect Al 7.

[0023] According to a nineteenth aspect Al 9, a glass composition comprises: greater than or equal to 20 mol% and less than or equal 46 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 13.3 mol% and less than or equal to 26 mol% MgO, wherein a total sum of concentrations of oxide components in the glass composition is equal to 100 mol%.

[0024] A twentieth aspect A20 includes the glass composition of the nineteenth aspect Al 9, wherein the glass composition comprises greater than or equal to 14 mol% and less than or equal to 18 mol% Y2O3.

[0025] A twenty -first aspect A21 includes the glass composition of the nineteenth aspect Al 9 or twentieth aspect A20, wherein the glass composition comprises greater than or equal to 15 mol% and less than or equal to 24 mol% MgO.

[0026] A twenty-second aspect A22 includes the glass composition of any one of the nineteenth through twenty-first aspects A19-A21, wherein the glass composition comprises greater than or equal to 25 mol% and less than or equal to 44 mol% SiO2.

[0027] A twenty-third aspect A23 includes the glass composition of any one of the nineteenth through twenty-second aspects A19-A22, wherein the glass composition comprises greater than or equal to 17 mol% and less than or equal to 35 mol% AI2O3.

[0028] A twenty-fourth aspect A24 includes the glass composition of any one of the nineteenth through twenty-third aspects A19-A23, wherein the glass composition comprises greater than or equal to 0.1 mol% and less than or equal to 25 mol% ZrCh.

[0029] A twenty-fifth aspect A25 includes the glass composition of any one of the nineteenth through twenty -fourth aspects A19-A24, wherein the glass composition comprises greater than or equal to 0.5 mol% and less than or equal to 25 mol% Nl^Os.

[0030] A twenty-sixth aspect A26 includes the glass composition of any one of the nineteenth through twenty-fifth aspects A19-A25, wherein the glass composition comprises greater than or equal to 0.5 mol% and less than or equal to 25 mol% Ta2Os.

[0031] A twenty-seventh aspect A27 includes the glass composition of any one of the nineteenth through twenty-sixth aspects A19-A26, wherein Y2O3 + MgO + ZrCh + Nl^Os + Ta20s is greater than or equal to 25.8 mol% and less than or equal to 55 mol%.

[0032] A twenty-eighth aspect A28 includes the glass composition of any one of the nineteenth through twenty-seventh aspects A19-A27, wherein the glass composition comprises greater than or equal to 1 mol% and less than or equal to 20 mol% Li2O.

[0033] A twenty-ninth aspect A29 includes the glass composition of any one of the nineteenth through twenty-eighth aspects A19-A28, wherein the glass composition comprises greater than 0 mol% and less than or equal to 20 mol% Na2O.

[0034] A thirtieth aspect A30 includes the glass composition of any one of the nineteenth through twenty-ninth aspects A19-A29, wherein the glass composition comprises greater than 0 mol% and less than or equal to 20 mol% CaO.

[0035] A thirty-first aspect A31 includes the glass composition of any one of the nineteenth through thirtieth aspects A19-A30, wherein the glass composition comprises greater than or equal to 0.1 mol% and less than or equal to 5 mol% B2O3.

[0036] A thirty-second aspect A32 includes the glass composition of any one of the nineteenth through thirty-first aspects A19-A31, wherein the glass composition is free or substantially free of T1O2.

[0037] A thirty-third aspect A33 includes the glass composition of any one of the nineteenth through thirty-second aspects A19-A32, wherein the glass composition comprises a liquidus temperature greater than or equal to 1200 °C.

[0038] According to a thirty-fourth aspect A34, a glass article includes the glass composition of any one of the nineteenth through thirty -third aspects A19-A33.

[0039] A thirty-fifth aspect A35 includes the glass article of the thirty-fourth aspect A34, wherein the glass article comprises a Young’s modulus greater than or equal to 100 GPa, as measured using resonant ultrasound spectroscopy in accordance with ASTM C623.

[0040] According to a thirty-sixth aspect A36, a consumer electronic device comprises: a housing having a front surface, a back surface, and side surfaces; and electrical components provided at least partially within the housing, the electrical components including at least a controller, a memory, and a display, the display being provided at or adjacent the front surface of the housing; wherein the display includes the glass article of the thirty-fourth aspect A34 or the thirty-fifth aspect A35.

[0041] According to a thirty-seventh aspect A37, a method of forming a glass article comprises: heating a glass composition, the glass composition comprising: greater than or equal to 20 mol% and less than or equal 60 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 0.05 mol% and less than 13.3 mol% MgO, wherein a total sum of concentrations of oxide components in the glass composition is equal to 100 mol%; and cooling the glass composition at a cooling rate greater than 50 °C / s to form the glass article.

[0042] A thirty-eighth aspect A38 includes the method of the thirty-seventh aspect A37, wherein the glass composition is cooled from a molding temperature to a formed temperature, wherein the formed temperature is greater than or equal to 400 °C less than the molding temperature.

[0043] A thirty -ninth aspect A39 includes the method of the thirty-seventh aspect A37 or the thirty eighth-aspect A38, wherein the glass composition is cooled for greater than 2 seconds.

[0044] A fortieth aspect A40 includes the method of any one of the thirty-seventh through thirtyninth aspects A37-A39, wherein the method comprises pressing and plastically deforming a gob of the glass composition.

[0045] A forty-first aspect A41 includes the method of any one of the thirty- seventh through fortieth aspects A37-A40, wherein the glass composition comprises a liquidus temperature greater than or equal to 1200 °C.

[0046] A forty-second aspect A42 includes the method of any one of the thirty- seventh through forty-first aspects A37-A41, wherein the glass composition comprises at least one of Li2O and Na2O.

[0047] A forty-third aspect A43 includes the method of the forty-second aspect A42, further comprising strengthening the glass article in an ion exchange bath at a temperature greater than or equal to 350 °C to less than or equal to 500 °C for a time period greater than or equal to 1 hour to less than or equal to 24 hours to form an ion exchanged glass article.

[0048] A forty-fourth aspect A44 includes the method of the forty -third aspect A43, wherein the ion exchange bath comprises NaNCh.

[0049] A forty-fifth aspect A45 includes the method of the forty-third aspect A43 or the fortyfourth aspect A44, wherein the ion exchange bath comprises KNO3.

[0050] A forty-sixth aspect A46 includes the method of any one of the thirty-seventh through forty-fifth aspects A37-A45, wherein the glass article comprises a Young’s modulus greater than or equal to 100 GPa, as measured using resonant ultrasound spectroscopy in accordance with ASTM C623.

[0051] According to a forty-seventh aspect A47, a method of forming a glass article comprises: heating a glass composition, the glass composition comprising: greater than or equal to 20 mol% and less than or equal 46 mol% SiO2; greater than or equal to 15 mol% and less than or equal to 40 mol% AbCh; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 13.3 mol% and less than or equal to 26 mol% MgO, wherein a total sum of concentrations of oxide components in the glass composition is equal to 100 mol%; and cooling the glass composition at a cooling rate greater than 50 °C / s to form the glass article.

[0052] A forty-eighth aspect A48 includes the method of the forty-seventh aspect A47, wherein the glass composition is cooled from a molding temperature to a formed temperature, wherein the formed temperature is greater than or equal to 400 °C less than the molding temperature.

[0053] A forty-ninth aspect A49 includes the method of the forty-seventh aspect A47 or the forty-eighth aspect A48, wherein the glass composition is cooled for greater than 2 seconds.

[0054] A fiftieth aspect A50 includes the method of the forty-seventh through forty-ninth aspects A47-A49, wherein the method comprises pressing and plastically deforming a gob of the glass composition.

[0055] A fifty-first aspect A51 includes the method of the forty-seventh through fiftieth aspects A47-A50, wherein the glass composition comprises a liquidus temperature greater than or equal to 1200 °C.

[0056] A fifty-second aspect A52 includes the method of the forty-seventh through fifty-first aspects A47-A51, wherein the glass composition comprises at least one of U2O and Na2O.

[0057] A fifty-third aspect A53 includes the method of the fifty-second aspect A52, further comprising strengthening the glass article in an ion exchange bath at a temperature greater than or equal to 350 °C to less than or equal to 500 °C for a time period greater than or equal to 1 hour to less than or equal to 24 hours to form an ion exchanged glass article.

[0058] A fifty-fourth aspect A54 includes the method of the fifty-third aspect A53, wherein the ion exchange bath comprises NaNCh.

[0059] A fifty-fifth aspect A55 includes the method of the fifty-third aspect A53 or the fiftyfourth aspect A54, wherein the ion exchange bath comprises KNO3.

[0060] A fifty-sixth aspect A56 includes the method of any one of the forty-seventh through fifty-fifth aspects A47-A55, wherein the glass article comprises a Young’s modulus greater than or equal to 100 GPa, as measured using resonant ultrasound spectroscopy in accordance with ASTM C623.BRIEF DESCRIPTION OF THE DRAWINGS

[0061] FIG. 1 is a plan view of an electronic device incorporating any of the glass articles according to one or more embodiments described herein.DETAILED DESCRIPTION

[0062] Reference will now be made in detail to various embodiments of glass compositions and glass articles formed therefrom having improved mechanical durability.

[0063] According to embodiments, a glass composition may comprise greater than or equal to 20 mol% and less than or equal 60 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 0.05 mol% and less than 13.3 mol% MgO. A total sum of oxide components in the glass composition may be equal to 100 mol%.

[0064] According to embodiments, a glass composition may comprise greater than or equal to 20 mol% and less than or equal 46 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 13.3 mol% and less than or equal to 26 mol% MgO. A total sum of oxide components in the glass composition may be equal to 100 mol%.

[0065] According to embodiments, a method of forming a glass article may comprise heating a glass composition and cooling the glass composition at a cooling rate greater than 50 °C / s to form the glass article. The glass composition may comprise greater than or equal to 20 mol% and less than or equal 60 mol% Si O2; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 0.05 mol% and less than 13.3 mol% MgO. A total sum of oxide components in the glass composition may be equal to 100 mol%.

[0066] According to embodiments, a method of forming a glass article may comprise heating a glass composition and cooling the glass composition at a cooling rate greater than 50 °C / s to form the glass article. The glass composition may comprise greater than or equal to 20 mol% and less than or equal 46 mol% Si O2; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 13.3 mol% and greater than or equal to 26 mol% MgO. A total sum of oxide components in the glass composition may be equal to 100 mol%.

[0067] Various embodiments of glass compositions and glass articles formed therefrom will be described herein with specific reference to the appended drawings.

[0068] Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0069] Directional terms as used herein - for example up, down, right, left, front, back, top, bottom - are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0070] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.

[0071] As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise.

[0072] As used herein, the phrase “at least one of’ does not modify each of the constituents or components in a list immediately following thereafter. For example, a recitation “at least one ofA, B, and C,” does not mean “at least one of A, at least one of B, and at least one of C.” Instead, this recitation indicates selection of at least one from a group including A, B, and C.

[0073] In the embodiments of the glass composition and the resultant glass article described herein, the concentrations of constituent components (e.g., SiCh, AI2O3, and the like) are specified in mole percent (mol%) on an oxide basis, unless otherwise specified. A total sum of concentrations of oxide components in the glass composition and the resultant glass article is equal to 100 mol%.

[0074] The term “substantially free,” when used to describe the concentration and / or absence of a particular constituent component in a glass composition and the resultant glass article, means that the constituent component is not intentionally added to the glass composition and the resultant glass article. However, the glass composition and the resultant glass article may contain traces of the constituent component as a contaminant or tramp in amounts of less than 0.05 weight percent (wt%). As noted herein, the remainder of the application specifies the concentrations of constituent component in mol%. The contaminant or tramp amounts of the constituent components are listed in wt% for manufacturing purposes and one skilled in the art would understand the contaminant and tramp amounts being listed in wt%.

[0075] The terms “0 mol%” and “free,” when used to describe the concentration and / or absence of a particular constituent component in a glass composition and the resultant glass article, means that the constituent component is not present in glass composition and the resultant glass article.

[0076] Density, as described herein, is measured by the buoyancy method of ASTM C693-93.

[0077] Refractive index, as described herein, is measured in accordance with ASTM El 967.

[0078] Stress optical coefficient (SOC), as described herein, is measured according to Procedure C (Glass Disc Method) described in ASTM standard C770-16, entitled “Standard Test Method for Measurement of Glass Stress-Optical Coefficient,” the contents of which are incorporated herein by reference in their entirety.

[0079] Young’s modulus, as described herein, is provided in units of gigapascals (GPa) and is measured using resonant ultrasound spectroscopy in accordance with ASTM C623, unless otherwise indicated.

[0080] Shear modulus, as described herein, is provided in units of gigapascals (GPa). The shear modulus of the glass composition is measured in accordance with ASTM C623, unless otherwise indicated.

[0081] Poisson’s ratio, as described herein, is measured in accordance with ASTM C623, unless otherwise indicated.

[0082] The term “liquidus temperature,” as described herein, refers to the temperature at which the glass composition begins to devitrify as determined with the gradient furnace method according to ASTM C829-81.

[0083] The term “strain point,” as described herein, refers to the temperature at which the viscosity of the glass composition is 1x101468poise as measured in accordance with ASTM C598.

[0084] The terms “anneal point” or “effective annealing temperature,” as described herein, refer to the temperature at which the viscosity of the glass composition is 1x1013 18poise as measured in accordance with ASTM C598.

[0085] The term “softening point,” as described herein, refers to the temperature at which the viscosity of the glass composition is IxlO76poise as measured in accordance with ASTM C598.

[0086] The term “linear coefficient of thermal expansion” or “CTE,” as described herein, is measured in accordance with ASTM E228-85 over the temperature range of 0 °C to 300 °C and is expressed in terms of “x 10'7 / °C” as an average over the temperature range.

[0087] Fracture toughness (Kic) represents the ability of a glass composition to resist fracture. Fracture toughness is measured on a non- strengthened glass article, such as measuring the Kic value prior to ion exchange treatment of the glass article, thereby representing a feature of a glass article prior to ion exchange. The fracture toughness test methods described herein are not suitable for glasses that have been exposed to ion exchange treatment. But, fracture toughnessmeasurements performed as described herein on the same glass article prior to ion exchange treatment correlate to fracture toughness after ion exchange treatment, and are accordingly used as such. The chevron notched short bar (CNSB) method utilized to measure the Kic value is disclosed in Reddy, K.P.R. et al, “Fracture Toughness Measurement of Glass and Ceramic Materials Using Chevron-Notched Specimens,” J. Am. Ceram. Soc., 71 [6], C-310-C-313 (1988) except that Y*mis calculated using equation 5 of Bubsey, R.T. et al., “Closed-Form Expressions for Crack-Mouth Displacement and Stress Intensity Factors for Chevron-Notched Short Bar and Short Rod Specimens Based on Experimental Compliance Measurements,” NASA Technical Memorandum 83796, pp. 1-30 (October 1992). Unless otherwise specified, all fracture toughness values were measured by chevron notched short bar (CNSB) method.

[0088] Vickers hardness, as described herein, is measured according to ASTM E384.

[0089] The term “low MgO,” as used herein, refers to glass compositions that include greater than or equal to 0.05 mol% and less than 13.3 mol% MgO.

[0090] The term “high MgO,” as used herein, refers to glass compositions that include greater than or equal to 13.3 mol% and less than or equal to 26 mol% MgO.

[0091] The description herein refers to both low MgO embodiments and high MgO embodiments, unless otherwise indicated. That is, ranges of constituents and properties provided herein may be applicable to both low MgO and high MgO embodiments.

[0092] The fracture toughness, scratch resistance, and frangibility of a glass article are generally controlled by the Young’s modulus of the glass. For example, for ion exchangeable glasses, a relatively high Young’s modulus may be advantageous because it increases the frangibility limit, allowing for more stress to be imparted before the glass becomes frangibility. Ion exchange may not be necessary if the glass achieves a desirably high Young’s modulus. Therefore, both ion exchangeable and non-ion-exchangeable glass compositions may be used to achieve a glass article having a relatively high Young’s modulus.

[0093] High field strength oxides such as Y2O3 and MgO may be added to increase the Young’s modulus of the glass. However, such oxides are generally highly refractory and, thus, additions of these oxides may increase the liquidus temperatures of the glass composition beyond thosesuitable for conventional glass manufacturing. Thus, alternative manufacturing methods may be considered such that glass compositions having a relatively high liquidus temperature may be manufactured to form glass articles having a relatively high Young’s modulus.

[0094] Disclosed herein are glass compositions and resultant glass articles that mitigate the aforementioned problems. Specifically, the glass compositions and the resultant glass articles disclosed herein comprise a relatively high concentration of Y2O3 (e.g., greater than or equal to 12.5 mol%) in combination with MgO, which results in glass compositions having improved Young’s modulus (e.g., greater than or equal to 100 GPa). In view of the relatively high liquidus temperatures (e.g., greater than or equal to 1200 °C) of the glass compositions disclosed herein, manufacturing methods that rapidly quench the glass composition (e.g., cooling rate greater than 50 °C / s) to reduce or avoid crystallization, such as gob pressing, may be used to form glass articles from the glass compositions.

[0095] The glass compositions and the resultant glass articles described herein may be described as aluminosilicate glass compositions and articles and comprise SiCh and AI2O3. The glass compositions and the resultant glass articles described herein also include Y2O3 in combination with MgO and optionally include ZrO2, bfcOs, and / or Ta20s to increase Young’s modulus. The glass compositions and the resultant glass articles described herein may also include alkali oxides, such as U2O and Na2O, to enable the ion exchangeability of the glass compositions.

[0096] SiO2 is the primary glass former in the glass compositions described herein and may function to stabilize the network structure of the resultant glass articles. The concentration of SiCh in the glass composition and the resultant glass article should be sufficiently high (e.g., greater than or equal to 20 mol%) to provide basic glass forming capability. In low MgO embodiments, the amount of SiO2 may be limited (e.g., less than or equal to 60 mol%) to control the softening point of the glass composition and, thus, may aid in improving the meltability and the formability of the resulting glass article. In high MgO embodiments, the amount of SiO2 may be limited (e.g., less than or equal to 46 mol%) to account for the MgO concentration.

[0097] Accordingly, in low MgO embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 20 mol% and less than or equal 60 mol% SiO2. In low MgO embodiments, the glass composition and the resultant glass article may comprise greaterthan or equal to 25 mol% and less than or equal to 55 mol% SiCh. In low MgO embodiments, the concentration of S i O2 in the glass composition and the resultant glass article may be greater than or equal to 20 mol%, greater than or equal to 25 mol%, greater than or equal to 30 mol%, greater than or equal to 35 mol%, or even greater than or equal to 40 mol%. In low MgO embodiments, the concentration of SiO2 in the glass composition and the resultant glass article may be less than or equal to 60 mol%, less than or equal to 57 mol%, less than or equal to 55 mol%, less than or equal to 53 mol%, or even less than or equal to 50 mol%. In low MgO embodiments, the concentration of SiO2 in the glass composition and the resultant glass article may be greater than or equal to 20 mol% and less than or equal to 60 mol%, greater than or equal to 20 mol% and less than or equal to 57 mol%, greater than or equal to 20 mol% and less than or equal to 55 mol%, greater than or equal to 20 mol% and less than or equal to 53 mol%, greater than or equal to 20 mol% and less than or equal to 50 mol%, greater than or equal to 25 mol% and less than or equal to 60 mol%, greater than or equal to 25 mol% and less than or equal to 57 mol%, greater than or equal to 25 mol% and less than or equal to 55 mol%, greater than or equal to 25 mol% and less than or equal to 53 mol%, greater than or equal to 25 mol% and less than or equal to 50 mol%, greater than or equal to 30 mol% and less than or equal to 60 mol%, greater than or equal to 30 mol% and less than or equal to 57 mol%, greater than or equal to 30 mol% and less than or equal to 55 mol%, greater than or equal to 30 mol% and less than or equal to 53 mol%, greater than or equal to 30 mol% and less than or equal to 50 mol%, greater than or equal to 35 mol% and less than or equal to 60 mol%, greater than or equal to 35 mol% and less than or equal to 57 mol%, greater than or equal to 35 mol% and less than or equal to 55 mol%, greater than or equal to 35 mol% and less than or equal to 53 mol%, greater than or equal to 35 mol% and less than or equal to 50 mol%, greater than or equal to 40 mol% and less than or equal to 60 mol%, greater than or equal to 40 mol% and less than or equal to 57 mol%, greater than or equal to 40 mol% and less than or equal to 55 mol%, greater than or equal to 40 mol% and less than or equal to 53 mol%, or even greater than or equal to 40 mol% and less than or equal to 50 mol%, or any and all sub-ranges formed from any of these endpoints.

[0098] In high MgO embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 20 mol% and less than or equal 46 mol% SiO2. In high MgO embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 25 mol% and less than or equal to 44 mol% SiO2. In high MgO embodiments, theconcentration of S i O2 in the glass composition and the resultant glass article may be greater than or equal to 20 mol%, greater than or equal to 25 mol%, greater than or equal to 30 %, or even greater than or equal to 35 mol%. In high MgO embodiments, the concentration of SiCh in the glass composition and the resultant glass article may be less than or equal to 46 mol%, less than or equal to 44 mol%, less than or equal to 42 mol%, or even less than or equal to 40 mol%. In high MgO embodiments, the concentration of SiO2 in the glass composition and the resultant glass article may be greater than or equal to 20 mol% and less than or equal 46 mol%, greater than or equal to 20 mol% and less than or equal 44 mol%, greater than or equal to 20 mol% and less than or equal 42 mol%, greater than or equal to 20 mol% and less than or equal 40 mol%, greater than or equal to 25 mol% and less than or equal 46 mol%, greater than or equal to 25 mol% and less than or equal 44 mol%, greater than or equal to 25 mol% and less than or equal 42 mol%, greater than or equal to 25 mol% and less than or equal 40 mol%, greater than or equal to 30 mol% and less than or equal 46 mol%, greater than or equal to 30 mol% and less than or equal 44 mol%, greater than or equal to 30 mol% and less than or equal 42 mol%, greater than or equal to 30 mol% and less than or equal 40 mol%, greater than or equal to 35 mol% and less than or equal 46 mol%, greater than or equal to 35 mol% and less than or equal 44 mol%, greater than or equal to 35 mol% and less than or equal 42 mol%, or even greater than or equal to 35 mol% and less than or equal 40 mol%, or any and all sub-ranges formed from any of these endpoints.

[0099] Like S iC>2, AI2O3 may also stabilize the glass network and additionally provide improved mechanical properties, such as Young’s modulus, and chemical durability to the resulting glass article. The amount of AI2O3 may also be tailored to the control the viscosity of the glass composition. The concentration of AI2O3 should be sufficiently high (e.g., greater than or equal to 15 mol%) such that the glass composition and the resultant glass article have the desired Young’s modulus (e.g., greater than or equal to 100 GPa). If the amount of AI2O3 is too high (e.g., greater than 40 mol%), the viscosity of the melt may increase, thereby diminishing the formability of the glass composition. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 17 mol% and less than or equal to 35 mol% AI2O3. In embodiments, the concentration of AI2O3 in the glass composition and the resultant glass article may be greater than or equal to 15 mol%, greater than or equal to 17 mol%, greater than or equal to 19 mol%, greater than or equalto 21 mol%, greater than or equal to 23 mol%, or even greater than or equal to 25 mol%. In embodiments, the concentration of AI2O3 in the glass composition and the resultant glass article may be less than or equal to 40 mol%, less than or equal to 37 mol%, less than or equal to 35 mol%, less than or equal to 33 mol%, less than or equal to 30 mol%, or even less than or equal to 27 mol%. In embodiments, the concentration of AI2O3 in the glass composition and the resultant glass article may be greater than or equal to 15 mol% and less than or equal to 40 mol%, greater than or equal to 15 mol% and less than or equal to 37 mol%, greater than or equal to 15 mol% and less than or equal to 35 mol%, greater than or equal to 15 mol% and less than or equal to 33 mol%, greater than or equal to 15 mol% and less than or equal to 30 mol%, greater than or equal to 15 mol% and less than or equal to 27 mol%, greater than or equal to 17 mol% and less than or equal to 40 mol%, greater than or equal to 17 mol% and less than or equal to 37 mol%, greater than or equal to 17 mol% and less than or equal to 35 mol%, greater than or equal to 17 mol% and less than or equal to 33 mol%, greater than or equal to 17 mol% and less than or equal to 30 mol%, greater than or equal to 17 mol% and less than or equal to 27 mol%, greater than or equal to 19 mol% and less than or equal to 40 mol%, greater than or equal to 19 mol% and less than or equal to 37 mol%, greater than or equal to 19 mol% and less than or equal to 35 mol%, greater than or equal to 19 mol% and less than or equal to 33 mol%, greater than or equal to 19 mol% and less than or equal to 30 mol%, greater than or equal to 19 mol% and less than or equal to 27 mol%, greater than or equal to 21 mol% and less than or equal to 40 mol%, greater than or equal to 21 mol% and less than or equal to 37 mol%, greater than or equal to 21 mol% and less than or equal to 35 mol%, greater than or equal to 21 mol% and less than or equal to 33 mol%, greater than or equal to 21 mol% and less than or equal to 30 mol%, greater than or equal to 21 mol% and less than or equal to 27 mol%, greater than or equal to 23 mol% and less than or equal to 40 mol%, greater than or equal to 23 mol% and less than or equal to 37 mol%, greater than or equal to 23 mol% and less than or equal to 35 mol%, greater than or equal to 23 mol% and less than or equal to 33 mol%, greater than or equal to 23 mol% and less than or equal to 30 mol%, greater than or equal to 23 mol% and less than or equal to 27 mol%, greater than or equal to 25 mol% and less than or equal to 40 mol%, greater than or equal to 25 mol% and less than or equal to 37 mol%, greater than or equal to 25 mol% and less than or equal to 35 mol%, greater than or equal to 25 mol% and less than or equal to 33 mol%, greater than or equal to 25 mol% and less than or equalto 30 mol%, or even greater than or equal to 25 mol% and less than or equal to 27 mol%, or any and all sub-ranges formed from any of these endpoints.

[0100] As noted hereinabove, Y2O3 and MgO may increase the Young’s modulus of the glass compositions and the resultant glass articles described herein.

[0101] In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 14 mol% and less than or equal to 18 mol% Y2O3. In embodiments, the concentration of Y2O3 in the glass composition and the resultant glass article may be greater than or equal to 12.5 mol%, greater than or equal to 13 mol%, greater than or equal to 13.5 mol%, or even greater than or equal to 14 mol%. In embodiments, the concentration of Y2O3 in the glass composition and the resultant glass article may be less than or equal to 20 mol%, less than or equal to 19 mol%, less than or equal to 18 mol%, less than or equal to 17 mol%, or even less than or equal to 16 mol%. In embodiments, the concentration of Y2O3 in the glass composition and the resultant glass article may be greater than or equal to 12.5 mol% and less than or equal to 20 mol%, greater than or equal to 12.5 mol% and less than or equal to 19 mol%, greater than or equal to 12.5 mol% and less than or equal to 18 mol%, greater than or equal to 12.5 mol% and less than or equal to 17 mol%, greater than or equal to 12.5 mol% and less than or equal to 16 mol%, greater than or equal to 13 mol% and less than or equal to 20 mol%, greater than or equal to 13 mol% and less than or equal to 19 mol%, greater than or equal to 13 mol% and less than or equal to 18 mol%, greater than or equal to 13 mol% and less than or equal to 17 mol%, greater than or equal to 13 mol% and less than or equal to 16 mol%, greater than or equal to 13.5 mol% and less than or equal to 20 mol%, greater than or equal to 13.5 mol% and less than or equal to 19 mol%, greater than or equal to 13.5 mol% and less than or equal to 18 mol%, greater than or equal to 13.5 mol% and less than or equal to 17 mol%, greater than or equal to 13.5 mol% and less than or equal to 16 mol%, greater than or equal to 14 mol% and less than or equal to 20 mol%, greater than or equal to 14 mol% and less than or equal to 19 mol%, greater than or equal to 14 mol% and less than or equal to 18 mol%, greater than or equal to 14 mol% and less than or equal to 17 mol%, or even greater than or equal to 14 mol% and less than or equal to 16 mol%, or any and all sub-ranges formed from any of these endpoints.

[0102] In low MgO embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.05 mol% and less than 13.3 mol% MgO. In low MgO embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.1 mol% and less than or equal to 11 mol% MgO. In low MgO embodiments, the concentration of MgO in the glass composition and the resultant glass article may be greater than or equal to 0.05 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol%, greater than or equal to 1 mol%, greater than or equal to 2 mol%, greater than or equal to 4 mol%, greater than or equal to 6 mol%, or even greater than or equal to 8 mol%. In embodiments, the concentration of MgO in the glass composition and the resultant glass article may be less than 13.3 mol%, less than or equal to 13 mol%, less than or equal to 11 mol%, less than or equal to 9 mol%, less than or equal to 7 mol%, less than or equal to 5 mol%, or even less than or equal to 3 mol%. In embodiments, the concentration of MgO in the glass composition and the resultant glass article may be greater than or equal to 0.05 mol% and less than 13.3 mol%, greater than or equal to 0.05 mol% and less than or equal to 13 mol%, greater than or equal to 0.05 mol% and less than or equal to 11 mol%, greater than or equal to 0.05 mol% and less than or equal to 9 mol%, greater than or equal to 0.05 mol% and less than or equal to 7 mol%, greater than or equal to 0.05 mol% and less than or equal to 5 mol%, greater than or equal to 0.05 mol% and less than or equal to 3 mol%, greater than or equal to 0.1 mol% and less than 13.3 mol%, greater than or equal to 0.1 mol% and less than or equal to 13 mol%, greater than or equal to 0.1 mol% and less than or equal to 11 mol%, greater than or equal to 0.1 mol% and less than or equal to 9 mol%, greater than or equal to 0.1 mol% and less than or equal to 7 mol%, greater than or equal to 0.1 mol% and less than or equal to 5 mol%, greater than or equal to 0.1 mol% and less than or equal to 3 mol%, greater than or equal to 0.5 mol% and less than 13.3 mol%, greater than or equal to 0.5 mol% and less than or equal to 13 mol%, greater than or equal to 0.5 mol% and less than or equal to 11 mol%, greater than or equal to 0.5 mol% and less than or equal to 9 mol%, greater than or equal to 0.5 mol% and less than or equal to 7 mol%, greater than or equal to 0.5 mol% and less than or equal to 5 mol%, greater than or equal to 0.5 mol% and less than or equal to 3 mol%, greater than or equal to 1 mol% and less than 13.3 mol%, greater than or equal to 1 mol% and less than or equal to 13 mol%, greater than or equal to 1 mol% and less than or equal to 11 mol%, greater than or equal to 1 mol% and less than or equal to 9 mol%, greater than or equal to 1 mol% and less than or equal to 7 mol%, greater than or equal to 1 mol% and less than or equal to 5 mol%, greater than or equal to 1 mol%and less than or equal to 3 mol%, greater than or equal to 2 mol% and less than 13.3 mol%, greater than or equal to 2 mol% and less than or equal to 13 mol%, greater than or equal to 2 mol% and less than or equal to 11 mol%, greater than or equal to 2 mol% and less than or equal to 9 mol%, greater than or equal to 2 mol% and less than or equal to 7 mol%, greater than or equal to 2 mol% and less than or equal to 5 mol%, greater than or equal to 2 mol% and less than or equal to 3 mol%, greater than or equal to 4 mol% and less than 13.3 mol%, greater than or equal to 4 mol% and less than or equal to 13 mol%, greater than or equal to 4 mol% and less than or equal to 11 mol%, greater than or equal to 4 mol% and less than or equal to 9 mol%, greater than or equal to 4 mol% and less than or equal to 7 mol%, greater than or equal to 4 mol% and less than or equal to 5 mol%, greater than or equal to 6 mol% and less than 13.3 mol%, greater than or equal to 6 mol% and less than or equal to 13 mol%, greater than or equal to 6 mol% and less than or equal to 11 mol%, greater than or equal to 6 mol% and less than or equal to 9 mol%, greater than or equal to 6 mol% and less than or equal to 7 mol%, greater than or equal to 8 mol% and less than 13.3 mol%, greater than or equal to 8 mol% and less than or equal to 13 mol%, greater than or equal to 8 mol% and less than or equal to 11 mol%, or even greater than or equal to 8 mol% and less than or equal to 9 mol%, or any and all sub-ranges formed from any of these endpoints.

[0103] In high MgO embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 13.3 mol% and less than or equal to 26 mol% MgO. In high MgO embodiments, the glass composition may comprise greater than or equal to 15 mol% and less than or equal to 24 mol% MgO. In high MgO embodiments, the concentration of MgO in the glass composition and the resultant glass article may be greater than or equal to 13.3 mol%, greater than or equal to 14 mol%, greater than or equal to 15 mol%, greater than or equal to 16 mol%, greater than or equal to 17 mol%, or even greater than or equal to 18 mol%. In high MgO embodiments, the concentration of MgO in the glass composition and the resultant glass article may be less than or equal to 26 mol%, less than or equal to 24 mol%, less than or equal to 22 mol%, less than or equal to 20 mol%, less than or equal to 18 mol%, or even less than or equal to 16 mol%. In high MgO embodiments, the concentration of MgO in the glass composition and the resultant glass article may be greater than or equal to 13.3 mol% and less than or equal to 26 mol%, greater than or equal to 13.3 mol% and less than or equal to 24 mol%, greater than or equal to 13.3 mol% and less than or equal to 22 mol%, greater than or equal to 13.3 mol% and less than or equal to 20 mol%, greater than or equal to 13.3 mol% and less than or equal to 18 mol%, greater than orequal to 13.3 mol% and less than or equal to 16 mol%, greater than or equal to 14 mol% and less than or equal to 26 mol%, greater than or equal to 14 mol% and less than or equal to 24 mol%, greater than or equal to 14 mol% and less than or equal to 22 mol%, greater than or equal to 14 mol% and less than or equal to 20 mol%, greater than or equal to 14 mol% and less than or equal to 18 mol%, greater than or equal to 14 mol% and less than or equal to 16 mol%, greater than or equal to 15 mol% and less than or equal to 26 mol%, greater than or equal to 15 mol% and less than or equal to 24 mol%, greater than or equal to 15 mol% and less than or equal to 22 mol%, greater than or equal to 15 mol% and less than or equal to 20 mol%, greater than or equal to 15 mol% and less than or equal to 18 mol%, greater than or equal to 15 mol% and less than or equal to 16 mol%, greater than or equal to 16 mol% and less than or equal to 26 mol%, greater than or equal to 16 mol% and less than or equal to 24 mol%, greater than or equal to 16 mol% and less than or equal to 22 mol%, greater than or equal to 16 mol% and less than or equal to 20 mol%, greater than or equal to 16 mol% and less than or equal to 18 mol%, greater than or equal to 17 mol% and less than or equal to 26 mol%, greater than or equal to 17 mol% and less than or equal to 24 mol%, greater than or equal to 17 mol% and less than or equal to 22 mol%, greater than or equal to 17 mol% and less than or equal to 20 mol%, greater than or equal to 17 mol% and less than or equal to 18 mol%, greater than or equal to 18 mol% and less than or equal to 26 mol%, greater than or equal to 18 mol% and less than or equal to 24 mol%, greater than or equal to 18 mol% and less than or equal to 22 mol%, or even greater than or equal to 18 mol% and less than or equal to 20 mol%, or any and all sub-ranges formed from any of these endpoints.

[0104] As noted hereinabove, the glass compositions and the resultant glass articles described herein may include ZrCh, bfeOs, and / or Ta2Os, which increase the Young’s modulus of the glass compositions and the resultant glass articles described herein.

[0105] In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.1 mol% and less than or equal to 25 mol% ZrCh. In embodiments, the concentration of ZrCh in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol%, greater than or equal to 1 mol%, greater than or equal to 2 mol%, greater than or equal to 3 mol%, greater than or equal to 4 mol%, or even greater than or equal to 5 mol%. In embodiments, the concentration of ZrCh in the glass composition and the resultant glass article may be less than orequal to 25 mol%, less than or equal to 20 mol%, less than or equal to 15 mol%, less than or equal to 12 mol%, less than or equal to 10 mol%, less than or equal to 8 mol%, less than or equal to 6 mol%, or even less than or equal to 4 mol%. In embodiments, the concentration of ZrCh in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 25 mol%, greater than or equal to 0 mol% and less than or equal to 20 mol%, greater than or equal to 0 mol% and less than or equal to 15 mol%, greater than or equal to 0 mol% and less than or equal to 12 mol%, greater than or equal to 0 mol% and less than or equal to 10 mol%, greater than or equal to 0 mol% and less than or equal to 8 mol%, greater than or equal to 0 mol% and less than or equal to 6 mol%, greater than or equal to 0 mol% and less than or equal to 4 mol%, greater than or equal to 0.1 mol% and less than or equal to 25 mol%, greater than or equal to 0.1 mol% and less than or equal to 20 mol%, greater than or equal to 0.1 mol% and less than or equal to 15 mol%, greater than or equal to 0.1 mol% and less than or equal to 12 mol%, greater than or equal to 0.1 mol% and less than or equal to 10 mol%, greater than or equal to 0.1 mol% and less than or equal to 8 mol%, greater than or equal to 0.1 mol% and less than or equal to 6 mol%, greater than or equal to 0.1 mol% and less than or equal to 4 mol%, greater than or equal to 0.5 mol% and less than or equal to 25 mol%, greater than or equal to 0.5 mol% and less than or equal to 20 mol%, greater than or equal to 0.5 mol% and less than or equal to 15 mol%, greater than or equal to 0.5 mol% and less than or equal to 12 mol%, greater than or equal to 0.5 mol% and less than or equal to 10 mol%, greater than or equal to 0.5 mol% and less than or equal to 8 mol%, greater than or equal to 0.5 mol% and less than or equal to 6 mol%, greater than or equal to 0.5 mol% and less than or equal to 4 mol%, greater than or equal to 1 mol% and less than or equal to 25 mol%, greater than or equal to 1 mol% and less than or equal to 20 mol%, greater than or equal to 1 mol% and less than or equal to 15 mol%, greater than or equal to 1 mol% and less than or equal to 12 mol%, greater than or equal to 1 mol% and less than or equal to 10 mol%, greater than or equal to 1 mol% and less than or equal to 8 mol%, greater than or equal to 1 mol% and less than or equal to 6 mol%, greater than or equal to 1 mol% and less than or equal to 4 mol%, greater than or equal to 2 mol% and less than or equal to 25 mol%, greater than or equal to 2 mol% and less than or equal to 20 mol%, greater than or equal to 2 mol% and less than or equal to 15 mol%, greater than or equal to 2 mol% and less than or equal to 12 mol%, greater than or equal to 2 mol% and less than or equal to 10 mol%, greater than or equal to 2 mol% and less than or equal to 8 mol%, greater than or equal to 2 mol% and less than or equal to 6 mol%, greater than or equal 1to 2 mol% and less than or equal to 4 mol%, greater than or equal to 3 mol% and less than or equal to 25 mol%, greater than or equal to 3 mol% and less than or equal to 20 mol%, greater than or equal to 3 mol% and less than or equal to 15 mol%, greater than or equal to 3 mol% and less than or equal to 12 mol%, greater than or equal to 3 mol% and less than or equal to 10 mol%, greater than or equal to 3 mol% and less than or equal to 8 mol%, greater than or equal to 3 mol% and less than or equal to 6 mol%, greater than or equal to 3 mol% and less than or equal to 4 mol%, greater than or equal to 4 mol% and less than or equal to 25 mol%, greater than or equal to 4 mol% and less than or equal to 20 mol%, greater than or equal to 4 mol% and less than or equal to 15 mol%, greater than or equal to 4 mol% and less than or equal to 12 mol%, greater than or equal to 4 mol% and less than or equal to 10 mol%, greater than or equal to 4 mol% and less than or equal to 8 mol%, greater than or equal to 4 mol% and less than or equal to 6 mol%, greater than or equal to 5 mol% and less than or equal to 25 mol%, greater than or equal to 5 mol% and less than or equal to 20 mol%, greater than or equal to 5 mol% and less than or equal to 15 mol%, greater than or equal to 5 mol% and less than or equal to 12 mol%, greater than or equal to 5 mol% and less than or equal to 10 mol%, greater than or equal to 5 mol% and less than or equal to 8 mol%, or even greater than or equal to 5 mol% and less than or equal to 6 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of ZrCh.

[0106] In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.5 mol% and less than or equal to 25 mol% bfeOs. In embodiments, the concentration of bfeOs in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.5 mol%, greater than or equal to 1 mol%, greater than or equal to 3 mol%, greater than or equal to 5 mol%, or even greater than or equal to 7 mol%. In embodiments, the concentration of bfeOs in the glass composition and the resultant glass article may be less than or equal to 25 mol%, less than or equal to 20 mol%, less than or equal to 15 mol%, less than or equal to 13 mol%, less than or equal to 11 mol%, less than or equal to 9 mol%, less than or equal to 7 mol%, or even less than or equal to 5 mol%. In embodiments, the concentration of bfeOs in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 25 mol%, greater than or equal to 0 mol% and less than or equal to 20 mol%, greater than or equal to 0 mol% and less than or equal to 15 mol%, greater than or equal to 0 mol% and less than or equal to 13 mol%, greater than or equal to 0 mol%and less than or equal to 11 mol%, greater than or equal to 0 mol% and less than or equal to 9 mol%, greater than or equal to 0 mol% and less than or equal to 7 mol%, greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0.5 mol% and less than or equal to 25 mol%, greater than or equal to 0.5 mol% and less than or equal to 20 mol%, greater than or equal to 0.5 mol% and less than or equal to 15 mol%, greater than or equal to 0.5 mol% and less than or equal to 13 mol%, greater than or equal to 0.5 mol% and less than or equal to 11 mol%, greater than or equal to 0.5 mol% and less than or equal to 9 mol%, greater than or equal to 0.5 mol% and less than or equal to 7 mol%, greater than or equal to 0.5 mol% and less than or equal to 5 mol%, greater than or equal to 1 mol% and less than or equal to 25 mol%, greater than or equal to 1 mol% and less than or equal to 20 mol%, greater than or equal to 1 mol% and less than or equal to 15 mol%, greater than or equal to 1 mol% and less than or equal to 13 mol%, greater than or equal to 1 mol% and less than or equal to 11 mol%, greater than or equal to 1 mol% and less than or equal to 9 mol%, greater than or equal to 1 mol% and less than or equal to 7 mol%, greater than or equal to 1 mol% and less than or equal to 5 mol%, greater than or equal to 3 mol% and less than or equal to 25 mol%, greater than or equal to 3 mol% and less than or equal to 20 mol%, greater than or equal to 3 mol% and less than or equal to 15 mol%, greater than or equal to 3 mol% and less than or equal to 13 mol%, greater than or equal to 3 mol% and less than or equal to 11 mol%, greater than or equal to 3 mol% and less than or equal to 9 mol%, greater than or equal to 3 mol% and less than or equal to 7 mol%, greater than or equal to 3 mol% and less than or equal to 5 mol%, greater than or equal to 5 mol% and less than or equal to 25 mol%, greater than or equal to 5 mol% and less than or equal to 20 mol%, greater than or equal to 5 mol% and less than or equal to 15 mol%, greater than or equal to 5 mol% and less than or equal to 13 mol%, greater than or equal to 5 mol% and less than or equal to 11 mol%, greater than or equal to 5 mol% and less than or equal to 9 mol%, greater than or equal to 5 mol% and less than or equal to 7 mol%, greater than or equal to 7 mol% and less than or equal to 25 mol%, greater than or equal to 7 mol% and less than or equal to 20 mol%, greater than or equal to 7 mol% and less than or equal to 15 mol%, greater than or equal to 7 mol% and less than or equal to 13 mol%, greater than or equal to 7 mol% and less than or equal to 11 mol%, or even greater than or equal to 7 mol% and less than or equal to 9 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of Nb2O5.

[0107] In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.5 mol% and less than or equal to 25 mol% Ta20s. In embodiments, the concentration of Ta20s in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.5 mol%, greater than or equal to 1 mol%, or even greater than or equal to 2 mol. In embodiments, the concentration of Ta2Os in the glass composition and the resultant glass article may be less than or equal to 25 mol%, less than or equal to 20 mol%, less than or equal to 15 mol%, less than or equal to 10 mol%, less than or equal to 7 mol%, or even less than or equal to 5 mol. In embodiments, the concentration of Ta2Os in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 25 mol%, greater than or equal to 0 mol% and less than or equal to 20 mol%, greater than or equal to 0 mol% and less than or equal to 15 mol%, greater than or equal to 0 mol% and less than or equal to 10 mol%, greater than or equal to 0 mol% and less than or equal to 7 mol%, greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0.5 mol% and less than or equal to 25 mol%, greater than or equal to 0.5 mol% and less than or equal to 20 mol%, greater than or equal to 0.5 mol% and less than or equal to 15 mol%, greater than or equal to 0.5 mol% and less than or equal to 10 mol%, greater than or equal to 0.5 mol% and less than or equal to 7 mol%, greater than or equal to 0.5 mol% and less than or equal to 5 mol%, greater than or equal to 1 mol% and less than or equal to 25 mol%, greater than or equal to1 mol% and less than or equal to 20 mol%, greater than or equal to 1 mol% and less than or equal to 15 mol%, greater than or equal to 1 mol% and less than or equal to 10 mol%, greater than or equal to 1 mol% and less than or equal to 7 mol%, greater than or equal to 1 mol% and less than or equal to 5 mol%, greater than or equal to 2 mol% and less than or equal to 25 mol%, greater than or equal to 2 mol% and less than or equal to 20 mol%, greater than or equal to 2 mol% and less than or equal to 15 mol%, greater than or equal to 2 mol% and less than or equal to 10 mol%, greater than or equal to 2 mol% and less than or equal to 7 mol%, or even greater than or equal to2 mol% and less than or equal to 5 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of Ta2Os.

[0108] In low MgO embodiments, the glass composition and the resultant glass article may comprise a total concentration or sum of Y2O3, MgO, ZrO2, and ISfeOs (i.e., Y2O3 (mol%) + MgO (mol%) + ZrO2 (mol%) + bfeOs (mol%)) greater than or equal to 12.5 mol% and less than or equalto 45 mol%. In low MgO embodiments, Y2O3 + MgO + ZrCh + bfeCh + Ta20s in the glass composition and the resultant glass article may be greater than or equal to 12.5 mol%, greater than or equal to 14 mol%, greater than or equal to 16 mol%, greater than or equal to 18 mol%, or even greater than or equal to 20 mol%. In low MgO embodiments, Y2O3 + MgO + ZrO2 + bfeOs + Ta20s in the glass composition and the resultant glass article may be less than or equal to 45 mol%, less than or equal to 40 mol%, less than or equal to 35 mol%, less than or equal to 30 mol%, or even less than or equal to 25 mol%. In low MgO embodiments, Y2O3 + MgO + ZrO2 + bfeOs + Ta20s in the glass composition and the resultant glass article may be greater than or equal to 12.5 mol% and less than or equal to 45 mol%, greater than or equal to 12.5 mol% and less than or equal to 40 mol%, greater than or equal to 12.5 mol% and less than or equal to 35 mol%, greater than or equal to 12.5 mol% and less than or equal to 30 mol%, greater than or equal to 12.5 mol% and less than or equal to 25 mol%, greater than or equal to 14 mol% and less than or equal to 45 mol%, greater than or equal to 14 mol% and less than or equal to 40 mol%, greater than or equal to 14 mol% and less than or equal to 35 mol%, greater than or equal to 14 mol% and less than or equal to 30 mol%, greater than or equal to 14 mol% and less than or equal to 25 mol%, greater than or equal to 16 mol% and less than or equal to 45 mol%, greater than or equal to 16 mol% and less than or equal to 40 mol%, greater than or equal to 16 mol% and less than or equal to 35 mol%, greater than or equal to 16 mol% and less than or equal to 30 mol%, greater than or equal to 16 mol% and less than or equal to 25 mol%, greater than or equal to 18 mol% and less than or equal to 45 mol%, greater than or equal to 18 mol% and less than or equal to 40 mol%, greater than or equal to 18 mol% and less than or equal to 35 mol%, greater than or equal to 18 mol% and less than or equal to 30 mol%, greater than or equal to 18 mol% and less than or equal to 25 mol%, greater than or equal to 20 mol% and less than or equal to 45 mol%, greater than or equal to 20 mol% and less than or equal to 40 mol%, greater than or equal to 20 mol% and less than or equal to 35 mol%, greater than or equal to 20 mol% and less than or equal to 30 mol%, or even greater than or equal to 20 mol% and less than or equal to 25 mol%, or any and all sub-ranges formed from any of these endpoints.

[0109] In high MgO embodiments, Y2O3 + MgO + ZrO2 + bfeOs + Ta2Os in the glass composition and the resultant glass article may be greater than or equal to 25.8 mol% and less than or equal to 55 mol%. In high MgO embodiments, Y2O3 + MgO + ZrO2 + Nb2Os + Ta2Os in the glass composition and the resultant glass article may be greater than or equal to 25.8 mol%, greaterthan or equal to 27 mol%, greater than or equal to 29 mol%, greater than or equal to 31 mol%, greater than or equal to 33 mol%, or even greater than or equal to 35 mol%. In high MgO embodiments, Y2O3 + MgO + ZrO2 + Nl^Os + Ta2Os in the glass composition and the resultant glass article may be less than or equal to 55 mol%, less than or equal to 50 mol%, less than or equal to 45 mol%, less than or equal to 40 mol%, or even less than or equal to 35 mol%. In high MgO embodiments, Y2O3 + MgO + ZrO2 + bfeOs + Ta2Os in the glass composition and the resultant glass article may be greater than or equal to 25.8 mol% and less than or equal to 55 mol%, greater than or equal to 25.8 mol% and less than or equal to 50 mol%, greater than or equal to 25.8 mol% and less than or equal to 45 mol%, greater than or equal to 25.8 mol% and less than or equal to 40 mol%, greater than or equal to 25.8 mol% and less than or equal to 35 mol%, greater than or equal to 27 mol% and less than or equal to 55 mol%, greater than or equal to 27 mol% and less than or equal to 50 mol%, greater than or equal to 27 mol% and less than or equal to 45 mol%, greater than or equal to 27 mol% and less than or equal to 40 mol%, greater than or equal to 27 mol% and less than or equal to 35 mol%, greater than or equal to 29 mol% and less than or equal to 55 mol%, greater than or equal to 29 mol% and less than or equal to 50 mol%, greater than or equal to 29 mol% and less than or equal to 45 mol%, greater than or equal to 29 mol% and less than or equal to 40 mol%, greater than or equal to 29 mol% and less than or equal to 35 mol%, greater than or equal to 31 mol% and less than or equal to 55 mol%, greater than or equal to 31 mol% and less than or equal to 50 mol%, greater than or equal to 31 mol% and less than or equal to 45 mol%, greater than or equal to 31 mol% and less than or equal to 40 mol%, greater than or equal to 31 mol% and less than or equal to 35 mol%, greater than or equal to 33 mol% and less than or equal to 55 mol%, greater than or equal to 33 mol% and less than or equal to 50 mol%, greater than or equal to 33 mol% and less than or equal to 45 mol%, greater than or equal to 33 mol% and less than or equal to 40 mol%, greater than or equal to 33 mol% and less than or equal to 35 mol%, greater than or equal to 35 mol% and less than or equal to 55 mol%, greater than or equal to 35 mol% and less than or equal to 50 mol%, greater than or equal to 35 mol% and less than or equal to 45 mol%, or even greater than or equal to 35 mol% and less than or equal to 40 mol%, or any and all sub-ranges formed from any of these endpoints.

[0110] The glass compositions and the resultant glass articles may contain alkali oxides, such as Li2O and Na2O, to enable the ion exchangeability of the resultant glass article. Li2O also reduces the softening point of the glass composition, thereby increasing the formability of the glass. Inembodiments, the glass composition and the resultant glass article may comprise greater than or equal to about 1 mol% and less than or equal to about 20 mol% Li2O. In embodiments, the concentration of Li2O in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.5 mol%, greater than or equal to 1 mol%, greater than or equal to 3 mol%, greater than or equal to 5 mol%, or even greater than or equal to 7 mol%. In embodiments, the concentration of Li2O in the glass composition and the resultant glass article may be less than or equal to 20 mol%, less than or equal to 18 mol%, less than or equal to 16 mol%, less than or equal to 14 mol%, less than or equal to 12 mol%, less than or equal to 10 mol%, or even less than or equal to 8 mol%. In embodiments, the concentration of Li2O in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 20 mol%, greater than or equal to 0 mol% and less than or equal to 18 mol%, greater than or equal to 0 mol% and less than or equal to 16 mol%, greater than or equal to 0 mol% and less than or equal to 14 mol%, greater than or equal to 0 mol% and less than or equal to 12 mol%, greater than or equal to 0 mol% and less than or equal to 10 mol%, greater than or equal to 0 mol% and less than or equal to 8 mol%, greater than or equal to 0.5 mol% and less than or equal to 20 mol%, greater than or equal to 0.5 mol% and less than or equal to 18 mol%, greater than or equal to 0.5 mol% and less than or equal to 16 mol%, greater than or equal to 0.5 mol% and less than or equal to 14 mol%, greater than or equal to 0.5 mol% and less than or equal to 12 mol%, greater than or equal to 0.5 mol% and less than or equal to 10 mol%, greater than or equal to 0.5 mol% and less than or equal to 8 mol%, greater than or equal to 1 mol% and less than or equal to 20 mol%, greater than or equal to 1 mol% and less than or equal to 18 mol%, greater than or equal to 1 mol% and less than or equal to 16 mol%, greater than or equal to 1 mol% and less than or equal to 14 mol%, greater than or equal to 1 mol% and less than or equal to 12 mol%, greater than or equal to 1 mol% and less than or equal to 10 mol%, greater than or equal to 1 mol% and less than or equal to 8 mol%, greater than or equal to 3 mol% and less than or equal to 20 mol%, greater than or equal to 3 mol% and less than or equal to 18 mol%, greater than or equal to 3 mol% and less than or equal to 16 mol%, greater than or equal to 3 mol% and less than or equal to 14 mol%, greater than or equal to 3 mol% and less than or equal to 12 mol%, greater than or equal to 3 mol% and less than or equal to 10 mol%, greater than or equal to 3 mol% and less than or equal to 8 mol%, greater than or equal to 5 mol% and less than or equal to 20 mol%, greater than or equal to 5 mol% and less than or equal to 18 mol%, greater than or equal to 5 mol% and less than or equalto 16 mol%, greater than or equal to 5 mol% and less than or equal to 14 mol%, greater than or equal to 5 mol% and less than or equal to 12 mol%, greater than or equal to 5 mol% and less than or equal to 10 mol%, greater than or equal to 5 mol% and less than or equal to 8 mol%, greater than or equal to 7 mol% and less than or equal to 20 mol%, greater than or equal to 7 mol% and less than or equal to 18 mol%, greater than or equal to 7 mol% and less than or equal to 16 mol%, greater than or equal to 7 mol% and less than or equal to 14 mol%, greater than or equal to 7 mol% and less than or equal to 12 mol%, greater than or equal to 7 mol% and less than or equal to 10 mol%, or even greater than or equal to 7 mol% and less than or equal to 8 mol%, or any and all sub-ranges formed from these endpoints. In embodiments, the glass composition may be free or substantially free of Li2O.

[0111] In addition to aiding in ion exchangeability of the glass composition, Na2O decreases the softening point and improves formability of the glass composition. However, if too much Na2O is added to the glass composition, the softening point may be too low. In embodiments, the glass composition and the resultant glass article may comprise greater than 0 mol% and less than or equal to 20 mol% Na2O. In embodiments, the concentration of Na2O in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.05 mol%, or even greater than or equal to 0.1 mol%. In embodiments, the concentration of Na2O in the glass composition and the resultant glass article may be less than or equal to 20 mol%, less than or equal to 15 mol%, less than or equal to 10 mol%, less than or equal to 5 mol%, less than or equal to 3 mol%, or even less than or equal to 1 mol%. In embodiments, the concentration of Na2O in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 20 mol%, greater than or equal to 0 mol% and less than or equal to 15 mol%, greater than or equal to 0 mol% and less than or equal to 10 mol%, greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0 mol% and less than or equal to 3 mol%, greater than or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0.05 mol% and less than or equal to 20 mol%, greater than or equal to 0.05 mol% and less than or equal to 15 mol%, greater than or equal to 0.05 mol% and less than or equal to 10 mol%, greater than or equal to 0.05 mol% and less than or equal to 5 mol%, greater than or equal to 0.05 mol% and less than or equal to 3 mol%, greater than or equal to 0.05 mol% and less than or equal to 1 mol%, greater than or equal to 0.1 mol% and less than or equal to 20 mol%, greater than or equal to 0.1 mol% and less than or equal to 15 mol%, greater than or equal to 0.1 mol% and less than orequal to 10 mol%, greater than or equal to 0. 1 mol% and less than or equal to 5 mol%, greater than or equal to 0.1 mol% and less than or equal to 3 mol%, or even greater than or equal to 0.1 mol% and less than or equal to 1 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition may be free or substantially free of Na2O.

[0112] The glass compositions and the resultant glass articles described herein may include other divalent oxides in addition to MgO, such as CaO. CaO may decrease the liquidus temperature of the glass composition. In embodiments, the glass composition and the resultant glass article may comprise greater than 0 mol% and less than or equal to 20 mol% CaO. In embodiments, the concentration of CaO in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.05 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol%, or even greater than or equal to 1 mol%. In embodiments, the concentration of CaO in the glass composition and the resultant glass article may be less than or equal to 20 mol%, less than or equal to 15 mol%, less than or equal to 10 mol%, less than or equal to 5 mol%, or even less than or equal to 1 mol%. In embodiments, the concentration of CaO in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 20 mol%, greater than or equal to 0 mol% and less than or equal to 15 mol%, greater than or equal to 0 mol% and less than or equal to 10 mol%, greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0.05 mol% and less than or equal to 20 mol%, greater than or equal to 0.05 mol% and less than or equal to 15 mol%, greater than or equal to 0.05 mol% and less than or equal to 10 mol%, greater than or equal to 0.05 mol% and less than or equal to 5 mol%, greater than or equal to 0.05 mol% and less than or equal to 1 mol%, greater than or equal to 0.1 mol% and less than or equal to 20 mol%, greater than or equal to 0.1 mol% and less than or equal to 15 mol%, greater than or equal to 0.1 mol% and less than or equal to 10 mol%, greater than or equal to 0.1 mol% and less than or equal to 5 mol%, greater than or equal to 0.1 mol% and less than or equal to 1 mol%, greater than or equal to 0.5 mol% and less than or equal to 20 mol%, greater than or equal to 0.5 mol% and less than or equal to 15 mol%, greater than or equal to 0.5 mol% and less than or equal to 10 mol%, greater than or equal to 0.5 mol% and less than or equal to 5 mol%, greater than or equal to 0.5 mol% and less than or equal to 1 mol%, greater than or equal to 1 mol% and less than or equal to 20 mol%, greater than or equal to 1 mol% and less than or equal to 15 mol%, greater than or equal to 1 mol% and less than or equalto 10 mol%, or even greater than or equal to 1 mol% and less than or equal to 5 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of CaO.

[0113] The glass compositions and the resultant glass articles described herein may include B2O3. B2O3 may decrease the liquidus temperature of the glass composition. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.1 mol% and less than or equal to 5 mol% B2O3. In embodiments, the concentration of B2O3 in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol%, or even greater than or equal to 1 mol%. In embodiments, the concentration of B2O3 in the glass composition and the resultant glass article may be less than or equal to 5 mol%, less than or equal to 4 mol%, less than or equal to 3 mol%, or even less than or equal to 2 mol%. In embodiments, the concentration of B2O3 in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0 mol% and less than or equal to 4 mol%, greater than or equal to 0 mol% and less than or equal to 3 mol%, greater than or equal to 0 mol% and less than or equal to 2 mol%, greater than or equal to 0.1 mol% and less than or equal to 5 mol%, greater than or equal to 0.1 mol% and less than or equal to 4 mol%, greater than or equal to 0.1 mol% and less than or equal to 3 mol%, greater than or equal to 0.1 mol% and less than or equal to 2 mol%, greater than or equal to 0.5 mol% and less than or equal to 5 mol%, greater than or equal to 0.5 mol% and less than or equal to 4 mol%, greater than or equal to 0.5 mol% and less than or equal to 3 mol%, greater than or equal to 0.5 mol% and less than or equal to 2 mol%, greater than or equal to 1 mol% and less than or equal to 5 mol%, greater than or equal to 1 mol% and less than or equal to 4 mol%, greater than or equal to 1 mol% and less than or equal to 3 mol%, or even greater than or equal to 1 mol% and less than or equal to 2 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of B2O3.

[0114] In embodiments, the glass composition may be free or substantially free of TiCh. TiCh may result in undesirable coloration and may also provide effective nucleation sites for undesirable crystallization to occur.

[0115] In embodiments, the glass compositions and the resultant glass article described herein may further include one or more fining agents. In embodiments, the fining agents may include, for example, SnCh. In embodiments, the concentration of SnCh in the glass composition and the resultant glass article may be greater than or equal to 0.05 mol% and less than or equal to 1 mol%, greater than or equal to 0.05 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.05 mol% and less than or equal to 0.25 mol%, greater than or equal to 0.1 mol% and less than or equal to 1 mol%, greater than or equal to 0.1 mol% and less than or equal to about 0.5 mol%, or even greater than or equal to 0.1 mol% and less than or equal to about 0.25 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be substantially free of SnCh.

[0116] In embodiments, the glass compositions and the resultant glass articles described herein may further include tramp materials such as FeO, Fe20s, MnO, MoOs, CdO, AS2O3, Sb2O3, sulfurbased compounds, such as sulfates, halogens, or combinations thereof.

[0117] According to embodiments, the glass composition and resultant glass article may comprise greater than or equal to 20 mol% and less than or equal 60 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 0.05 mol% and less than 13.3 mol% MgO. A total sum of oxide components in the glass composition may be equal to 100 mol%.

[0118] According to embodiments, the glass composition and resultant glass article may comprise greater than or equal to 20 mol% and less than or equal 46 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 13.3 mol% and less than or equal to 26 mol% MgO. A total sum of oxide components in the glass composition may be equal to 100 mol%.

[0119] The articles formed from the glass compositions described herein may be any suitable shape or thickness, which may vary depending on the particular application for use of the glass composition. Glass sheet embodiments may have a thickness greater than or equal to about 30 pm, greater than or equal to about 50 pm, greater than or equal to about 100 pm, greater than or equal to about 250 pm, greater than or equal to about 500 pm, greater than or equal to about 750gm, or even greater than or equal to about 1 mm. In embodiments, the glass sheet embodiments may have a thickness less than or equal to about 6 mm, less than or equal to about 5 mm, less than or equal to about 4 mm, less than or equal to about 3 mm, or even less than or equal to about 2 mm. In embodiments, the glass sheet embodiments may have a thickness greater than or equal to about 30 gm and less than or equal to about 6 mm, greater than or equal to about 30 um and less than or equal to about 5 mm, greater than or equal to about 30 gm and less than or equal to about 4 mm, greater than or equal to about 30 gm and less than or equal to about 3 mm, greater than or equal to about 30 gm and less than or equal to about 2 mm, greater than or equal to about 50 gm and less than or equal to about 6 mm, greater than or equal to about 50 gm and less than or equal to about 5 mm, greater than or equal to about 50 gm and less than or equal to about 4 mm, greater than or equal to about 50 gm and less than or equal to about 3 mm, greater than or equal to about 50 gm and less than or equal to about 2 mm, greater than or equal to about 100 gm and less than or equal to about 6 mm, greater than or equal to about 100 gm and less than or equal to about 5 mm, greater than or equal to about 100 gm and less than or equal to about 4 mm, greater than or equal to about 100 gm and less than or equal to about 3 mm, greater than or equal to about 100 gm and less than or equal to about 2 mm, greater than or equal to about 250 gm and less than or equal to about 6 mm, greater than or equal to about 250 gm and less than or equal to about 5 mm, greater than or equal to about 250 gm and less than or equal to about 4 mm, greater than or equal to about 250 gm and less than or equal to about 3 mm, greater than or equal to about 250 gm and less than or equal to about 2 mm, greater than or equal to about 500 gm and less than or equal to about 6 mm, greater than or equal to about 500 gm and less than or equal to about 5 mm, greater than or equal to about 500 gm and less than or equal to about 4 mm, greater than or equal to about 500 gm and less than or equal to about 3 mm, greater than or equal to about 500 gm and less than or equal to about 2 mm, greater than or equal to about 750 gm and less than or equal to about 6 mm, greater than or equal to about 750 gm and less than or equal to about 5 mm, greater than or equal to about 750 gm and less than or equal to about 4 mm, greater than or equal to about 750 gm and less than or equal to about 3 mm, greater than or equal to about 750 gm and less than or equal to about 2 mm, greater than or equal to about 1 mm and less than or equal to about 6 mm, greater than or equal to about 1 mm and less than or equal to about 5 mm, greater than or equal to about 1 mm and less than or equal to about 4 mm, greater than or equal to about 1 mm and lessthan or equal to about 3 mm, or even greater than or equal to about 1 mm and less than or equal to about 2 mm, or any and all sub-ranges formed from any of these endpoints.

[0120] As discussed hereinabove, the glass compositions and the resultant glass articles described herein may have increased Young’s modulus such that the glass compositions and the resultant glass articles are more elastic. In embodiments, the glass composition and the resultant glass article may have a Young’s modulus greater than or equal to 100 GPa, greater than or equal to 105 GPa, greater than or equal to 110 GPa, greater than or equal to 115 GPa, greater than or equal to 120 GPa, or even greater than or equal to 125 GPa. In embodiments, the glass composition and the resultant glass article may have a Young’s modulus less than or equal to 200 GPa, less than or equal to 175 GPa, or even less than or equal to 150 GPa. In embodiments, the glass composition and the resultant glass article may have a Young’s modulus greater than or equal to 100 GPa and less than or equal to 200 GPa, greater than or equal to 100 GPa and less than or equal to 175 GPa, greater than or equal to 100 GPa and less than or equal to 150 GPa, greater than or equal to 105 GPa and less than or equal to 200 GPa, greater than or equal to 105 GPa and less than or equal to 175 GPa, greater than or equal to 105 GPa and less than or equal to 150 GPa, greater than or equal to 110 GPa and less than or equal to 200 GPa, greater than or equal to 110 GPa and less than or equal to 175 GPa, greater than or equal to 110 GPa and less than or equal to 150 GPa, greater than or equal to 115 GPa and less than or equal to 200 GPa, greater than or equal to 115 GPa and less than or equal to 175 GPa, greater than or equal to 115 GPa and less than or equal to 150 GPa, greater than or equal to 120 GPa and less than or equal to 200 GPa, greater than or equal to 120 GPa and less than or equal to 175 GPa, greater than or equal to 120 GPa and less than or equal to 150 GPa, greater than or equal to 125 GPa and less than or equal to 200 GPa, greater than or equal to 125 GPa and less than or equal to 175 GPa, or even greater than or equal to 125 GPa and less than or equal to 150 GPa, or any and all sub-ranges formed from any of these endpoints.

[0121] As discussed hereinabove, the glass compositions and the resultant glass articles described herein may have relatively high liquidus temperatures (e.g., greater than or equal to 1200 °C) due to the inclusion of high field strength oxides such as Y2O3 and MgO and optionally ZrCh, Nb2Os, and / or Ta2Os. In embodiments, the glass composition and the resultant glass article may comprise a liquidus temperature greater than or equal to 1200 °C. In embodiments, may comprise a liquidus temperature greater than or equal to 1200 °C, greater than or equal to 1250 °C, greaterthan or equal to 1300 °C, greater than or equal to 1350 °C, greater than or equal to 1400 °C, or even greater than or equal to 1450 °C. In embodiments, may comprise a liquidus temperature less than or equal to 1600 °C, less than or equal to 1550 °C, less than or equal to 1500 °C, or even less than or equal to 1450 °C. In embodiments, the glass composition and the resultant glass article may comprise a liquidus temperature greater than or equal to 1200 °C and less than or equal to 1600 °C, greater than or equal to 1200 °C and less than or equal to 1550 °C, greater than or equal to 1200 °C and less than or equal to 1500 °C, greater than or equal to 1200 °C and less than or equal to 1450 °C, greater than or equal to 1250 °C and less than or equal to 1600 °C, greater than or equal to 1250 °C and less than or equal to 1550 °C, greater than or equal to 1250 °C and less than or equal to 1500 °C, greater than or equal to 1250 °C and less than or equal to 1450 °C, greater than or equal to 1300 °C and less than or equal to 1600 °C, greater than or equal to 1300 °C and less than or equal to 1550 °C, greater than or equal to 1300 °C and less than or equal to 1500 °C, greater than or equal to 1300 °C and less than or equal to 1450 °C, greater than or equal to 1350 °C and less than or equal to 1600 °C, greater than or equal to 1350 °C and less than or equal to 1550 °C, greater than or equal to 135 °C and less than or equal to 1500 °C, greater than or equal to 1350 °C and less than or equal to 1450 °C, greater than or equal to 1400 °C and less than or equal to 1600 °C, greater than or equal to 1400 °C and less than or equal to 1550 °C, greater than or equal to 1400 °C and less than or equal to 1500 °C, greater than or equal to 1400 °C and less than or equal to 1450 °C, greater than or equal to 1450 °C and less than or equal to 1600 °C, greater than or equal to 1450 °C and less than or equal to 1550 °C, or even greater than or equal to 1450 °C and less than or equal to 1500 °C, or any and all sub-ranges formed from any of these endpoints.

[0122] The glass compositions and the resultant glass articles described herein may comprise relatively high strain, anneal, and softening appoints, thereby allowing for high temperature, secondary processing steps, such as ion exchange and heat treatments to further improve mechanical properties (e.g., Young’s modulus).

[0123] In embodiments, the glass composition and the resultant glass article may have a strain point greater than or equal to 600 °C, greater than or equal to 650 °C, or even greater than or equal to 700 °C. In embodiments, the glass composition and the resultant glass article may have a strain point less than or equal to 950 °C, less than or equal to 900 °C, or even less than or equal to 850 °C. In embodiments, the glass composition and the resultant glass article may have a strain pointgreater than or equal to 600 °C and less than or equal to 950 °C, greater than or equal to 600 °C and less than or equal to 900 °C, greater than or equal to 600 °C and less than or equal to 850 °C, greater than or equal to 650 °C and less than or equal to 950 °C, greater than or equal to 650 °C and less than or equal to 900 °C, greater than or equal to 650 °C and less than or equal to 850 °C, greater than or equal to 700 °C and less than or equal to 950 °C, greater than or equal to 700 °C and less than or equal to 900 °C, or even greater than or equal to 700 °C and less than or equal to 850 °C, or any and all sub-ranges formed from any of these endpoints.

[0124] In embodiments, the glass composition and the resultant glass article may have an anneal point greater than or equal to 600 °C, greater than or equal to 650 °C, or even greater than or equal to 700 °C. In embodiments, the glass composition and the resultant glass article may have an anneal point less than or equal to 1000 °C, less than or equal to 950 °C, or even less than or equal to 900 °C. In embodiments, the glass composition and the resultant glass article may have an anneal point greater than or equal to 600 °C and less than or equal to 1000 °C, greater than or equal to 600 °C and less than or equal to 950 °C, greater than or equal to 600 °C and less than or equal to 900 °C, greater than or equal to 650 °C and less than or equal to 1000 °C, greater than or equal to 650 °C and less than or equal to 950 °C, greater than or equal to 650 °C and less than or equal to 900 °C, greater than or equal to 700 °C and less than or equal to 1000 °C, greater than or equal to 700 °C and less than or equal to 950 °C, or even greater than or equal to 700 °C and less than or equal to 900 °C, or any and all sub-ranges formed from any of these endpoints.

[0125] In embodiments, the glass composition and the resultant glass article may have a softening point greater than or equal to 800 °C, greater than or equal to 850 °C, or even greater than or equal to 900 °C. In embodiments, the glass composition and the resultant glass article may have a softening point less than or equal to 1150 °C, less than or equal to 1100 °C, or even less than or equal to 1050 °C. In embodiments, the glass composition and the resultant glass article may have a softening point greater than or equal to 800 °C and less than or equal to 1150 °C, greater than or equal to 800 °C and less than or equal to 1100 °C, greater than or equal to 800 °C and less than or equal to 1050 °C, greater than or equal to 850 °C and less than or equal to 1150 °C, greater than or equal to 850 °C and less than or equal to 1100 °C, greater than or equal to 850 °C and less than or equal to 1050 °C, greater than or equal to 900 °C and less than or equal to 1150 °C, greater than or equal to 900 °C and less than or equal to 1100 °C, or even greater than or equalto 900 °C and less than or equal to 1050 °C, or any and all sub-ranges formed from any of these endpoints.

[0126] In embodiments, the glass composition and the resultant glass article may have a density greater than or equal to 2.8 g / cm3, greater than or equal to 3.0 g / cm3, or even greater than or equal to 3.2 g / cm3. In embodiments, the glass composition and the resultant glass article may have a density less than or equal to 4.4 g / cm3, less than or equal to 4.2 g / cm3, less than or equal to 4.0 g / cm3, or even less than or equal to 3.8 g / cm3. In embodiments, the glass composition and the resultant glass article may have a density greater than or equal to 2.8 g / cm3and less than or equal to 4.4 g / cm3, greater than or equal to 2.8 g / cm3and less than or equal to 4.2 g / cm3, greater than or equal to 2.8 g / cm3and less than or equal to 4.0 g / cm3, greater than or equal to 2.8 g / cm3and less than or equal to 3.8 g / cm3, greater than or equal to 3.0 g / cm3and less than or equal to 4.4 g / cm3, greater than or equal to 3.0 g / cm3and less than or equal to 4.2 g / cm3, greater than or equal to 3.0 g / cm3and less than or equal to 4.0 g / cm3, greater than or equal to 3.0 g / cm3and less than or equal to 3.8 g / cm3, greater than or equal to 3.2 g / cm3and less than or equal to 4.4 g / cm3, greater than or equal to 3.2 g / cm3and less than or equal to 4.2 g / cm3, greater than or equal to 3.2 g / cm3and less than or equal to 4.0 g / cm3, or even greater than or equal to 3.2 g / cm3and less than or equal to 3.8 g / cm3, or any and all sub-ranges formed from any of these endpoints.

[0127] In embodiments, the glass composition and the resultant glass article may have a refractive index greater than or equal to 1.4, greater than or equal to 1.5, or even greater than or equal to 1.6. In embodiments, the glass composition and the resultant glass article may have a refractive index less than or equal to 2.0, less than or equal to 1.9, or even less than or equal to 1.8. In embodiments, the glass composition and the resultant glass article may have a refractive index greater than or equal to 1.4 and less than or equal to 2.0, greater than or equal to 1.4 and less than or equal to 1.9, greater than or equal to 1.4 and less than or equal to 1.8, greater than or equal to 1.5 and less than or equal to 2.0, greater than or equal to 1.5 and less than or equal to 1.9, greater than or equal to 1.5 and less than or equal to 1.8, greater than or equal to 1.6 and less than or equal to 2.0, greater than or equal to 1.6 and less than or equal to 1.9, or even greater than or equal to 1.6 and less than or equal to 1.8, or any and all sub-ranges formed from any of these endpoints.

[0128] In embodiments, the glass composition and the resultant glass article may have a SOC greater than or equal to 1.6 nm / mm / MPa or even greater than or equal to 1.8 nm / mm / MPa. In embodiments, the glass composition and the resultant glass article may have a SOC less than or equal to 2.5 nm / mm / MPa or less than or equal to 2.3 nm / mm / MPa. In embodiments, the glass composition and the resultant glass article may have a SOC greater than or equal to 1.6 nm / mm / MPa and less than or equal to 2.5 nm / mm / MPa, greater than or equal to 1.6 nm / mm / MPa and less than or equal to 2.3 nm / mm / MPa, greater than or equal to 1.8 nm / mm / MPa and less than or equal to 2.5 nm / mm / MPa, or even greater than or equal to 1.8 nm / mm / MPa and less than or equal to 2.3 nm / mm / MPa, or any and all sub-ranges formed from any of these endpoints.

[0129] In embodiments, the glass composition and the resultant glass article may have a shear modulus greater than or equal to 30 GPa, greater than or equal to 35 GPa, or even greater than or equal to 40 GPa. In embodiments, the glass composition and the resultant glass article may have a shear modulus less than or equal to 65 GPa, less than or equal to 60 GPa, or even less than or equal to 55 GPa. In embodiments, the glass composition and the resultant glass article may have a shear modulus greater than or equal to 30 GP and less than or equal to 65 GPa, greater than or equal to 30 GP and less than or equal to 60 GPa, greater than or equal to 30 GP and less than or equal to 55 GPa, greater than or equal to 35 GP and less than or equal to 65 GPa, greater than or equal to 35 GP and less than or equal to 60 GPa, greater than or equal to 35 GP and less than or equal to 55 GPa, greater than or equal to 40 GP and less than or equal to 65 GPa, greater than or equal to 40 GP and less than or equal to 60 GPa, or even greater than or equal to 40 GP and less than or equal to 55 GPa, or any and all sub-ranges formed from any of these endpoints.

[0130] In embodiments, the glass composition and the resultant glass article may have a Poisson’s ratio greater than or equal to 0.22, greater than or equal to 0.24, or even greater than or equal to 0.26. In embodiments, the glass composition and the resultant glass article may have a Poisson’s ratio less than or equal to 0.33, less than or equal to 0.31, or even less than or equal to 0.29. In embodiments, the glass composition and the resultant glass article may have a Poisson’s ratio greater than or equal to 0.22 and less than or equal to 0.33, greater than or equal to 0.22 and less than or equal to 0.31, greater than or equal to 0.22 and less than or equal to 0.29, greater than or equal to 0.24 and less than or equal to 0.33, greater than or equal to 0.24 and less than or equal to 0.31, greater than or equal to 0.24 and less than or equal to 0.29, greater than or equal to 0.26and less than or equal to 0.33, greater than or equal to 0.26 and less than or equal to 0.31, or even greater than or equal to 0.26 and less than or equal to 0.29, or any and all sub-ranges formed from any of these endpoints.

[0131] In embodiments, the glass composition and the resultant glass article may have a CTE greater than or equal to 35 x 10'7 / °C, greater than or equal to 40 x 10'7 / °C, or even greater than or equal to 45 x 10'7 / °C. In embodiments, the glass composition and the resultant glass article may have a CTE less than or equal to 70 x 10'7 / °C, less than or equal to 65 x 10'7 / °C, or even less than or equal to 60 x 10'7 / °C. In embodiments, the glass composition and the resultant glass article may have a CTE greater than or equal to 35 x 10'7 / °C and less than or equal to 70 x 10'7 / °C, greater than or equal to 35 x 10'7 / °C and less than or equal to 65 x 10'7 / °C, greater than or equal to 35 x 10'7 / °C and less than or equal to 60 x 10'7 / °C, greater than or equal to 40 x 10'7 / °C and less than or equal to 70 x 10'7 / °C, greater than or equal to 40 x 10'7 / °C and less than or equal to 65 x 10'7 / °C, greater than or equal to 40 x 10'7 / °C and less than or equal to 60 x 10'7 / °C, greater than or equal to 45 x 10'7 / °C and less than or equal to 70 x 10'7 / °C, greater than or equal to 45 x 10'7 / °C and less than or equal to 65 x 10'7 / °C, or even greater than or equal to 45 x 10'7 / °C and less than or equal to 60 x 10'7 / °C, or any and all sub-ranges formed from any of these endpoints.

[0132] In embodiments, the glass composition and the resultant glass article may have a Ki0fracture toughness of greater than or equal to 0.7 MPa m1 2, greater than or equal to 0.8 MPa m1 2, greater than or equal to 0.9 MPa m1 2, or even greater than or equal to 1 MPa m1 2.

[0133] In embodiments, the glass composition and the result glass article make have a Vickers hardness greater than or equal to 800 kgf / mm2

[0134] In embodiments, the method for forming a glass article may include heat treating the glass composition as described herein at one or more preselected temperatures for one or more preselected times to melt the glass composition and cooling the glass composition. As described herein, the glass compositions may have relatively high liquidus temperatures (e.g., greater than or equal to 1200 °C) that are beyond those suitable for conventional glass manufacturing. In embodiments, manufacturing methods that rapidly quench the glass composition (e.g., cooling rate greater than 50 °C / s) to reduce or avoid crystallization may be used to form glass articles from the glass compositions disclosed herein.

[0135] In embodiments, the heat treatment for making a glass article may include: (i) heating a glass composition at a rate of about 1-100 °C / min to a molding temperature; and (ii) and cooling the glass composition from the molding temperature to a formed temperature at a cooling rate greater than 50 °C / s, thereby forming the glass article.

[0136] “Molding temperature,” as used herein, refers to the temperature of the glass composition when it is poured onto a mold. The molding temperature may be a temperature greater than the liquidus temperature of the glass composition that obtains a crystal-free part. Accordingly, in embodiments, the molding temperature may be greater than or equal to 1200 °C, greater than or equal to 1250 °C, greater than or equal to 1300 °C, greater than or equal to 1350 °C, greater than or equal to 1400 °C, or even greater than or equal to 1450 °C. In embodiments, the molding temperature may be less than or equal to 1700 °C, less than or equal to 1650 °C, less than or equal to 1600 °C, or even less than or equal to 1550 °C. In embodiments, the molding temperature may be greater than or equal to 1200 °C and less than or equal to 1700 °C, greater than or equal to 1200 °C and less than or equal to 1650 °C, greater than or equal to 1200 °C and less than or equal to 1600 °C, greater than or equal to 1200 °C and less than or equal to 1550 °C, greater than or equal to 1250 °C and less than or equal to 1700 °C, greater than or equal to 1250 °C and less than or equal to 1650 °C, greater than or equal to 1250 °C and less than or equal to 1600 °C, greater than or equal to 1250 °C and less than or equal to 1550 °C, greater than or equal to 1300 °C and less than or equal to 1700 °C, greater than or equal to 1300 °C and less than or equal to 1650 °C, greater than or equal to 1300 °C and less than or equal to 1600 °C, greater than or equal to 1300 °C and less than or equal to 1550 °C, greater than or equal to 1350 °C and less than or equal to 1700 °C, greater than or equal to 1350 °C and less than or equal to 1650 °C, greater than or equal to 1350 °C and less than or equal to 1600 °C, greater than or equal to 1350 °C and less than or equal to 1550 °C, greater than or equal to 1400 °C and less than or equal to 1700 °C, greater than or equal to 1400 °C and less than or equal to 1650 °C, greater than or equal to 1400 °C and less than or equal to 1600 °C, greater than or equal to 1400 °C and less than or equal to 1550 °C, greater than or equal to 1450 °C and less than or equal to 1700 °C, greater than or equal to 1450 °C and less than or equal to 1650 °C, greater than or equal to 1450 °C and less than or equal to 1600 °C, or even greater than or equal to 1450 °C and less than or equal to 1550 °C, or any and all sub-ranges formed from any of these endpoints.

[0137] In embodiments, the formed temperature may be greater than or equal to 400 °C, greater than or equal to 500 °C, greater than or equal to 600 °C, or even greater than or equal to 700 °C less than the molding temperature. In embodiments, the formed temperature may be greater than or equal to 750 °C, greater than or equal to 800 °C, or even greater than or equal to 850 °C. In embodiments, the formed temperature may be less than or equal to 1050 °C, less than or equal to 1000 °C, or even less than or equal to 950 °C. In embodiments, the formed temperature may be greater than or equal to 750 °C and less than or equal to 1050 °C, greater than or equal to 750 °C and less than or equal to 1000 °C, greater than or equal to 750 °C and less than or equal to 950 °C, greater than or equal to 800 °C and less than or equal to 1050 °C, greater than or equal to 800 °C and less than or equal to 1000 °C, greater than or equal to 800 °C and less than or equal to 950 °C, greater than or equal to 850 °C and less than or equal to 1050 °C, greater than or equal to 850 °C and less than or equal to 1000 °C, or even greater than or equal to 850 °C and less than or equal to 950 °C, or any and all sub-ranges formed from any of these endpoints.

[0138] In embodiments, the cooling rate may be greater than 50 °C / s, greater than 60 °C / s, greater than 70 °C / s, greater than 80 °C / s, greater than 90 °C / s, or even greater than 100 °C / s. In embodiments, the glass composition may be cooled for greater than 2 seconds, greater than 3 seconds, greater than 4 seconds, greater than 5 seconds, or even greater than 6 seconds.

[0139] Various manufacturing methods may be used to form glass articles from the glass compositions described herein, provided that the method rapidly quenches the glass composition (e.g., cooling rate greater than 50 °C / s) to reduce or avoid crystallization. For example, in embodiments, the method may comprise pressing and plastically deforming a gob of the glass composition. Such “gob-pressing methods” are described in U.S. Patent Application No. 18 / 388,235 filed November 9, 2023, which is hereby incorporated herein by reference in its entirety. In such gob-pressing methods, the cooling step may comprise: (i) pouring the glass composition into a mold; (ii) traversing the mold into a press; (iii) pressing the glass composition; and (iv) traversing the mold out of the press.

[0140] In embodiments, the glass compositions described herein are ion exchangeable to facilitate strengthening the glass articles made from the glass compositions. In typical ion exchange processes, smaller metal ions in the glass article are replaced or “exchanged” with largermetal ions of the same valence within a layer that is close to the outer surface of the glass article. The replacement of smaller ions with larger ions creates a compressive stress within the layer of the glass article. In embodiments, the metal ions are monovalent metal ions (e.g., Li+, Na+, K+, and the like), and ion exchange is accomplished by immersing the glass article in a bath comprising at least one molten salt of the larger metal ion that is to replace the smaller metal ion in the glass article. Alternatively, other monovalent ions such as Ag+, Tl+, Cu+, and the like may be exchanged for monovalent ions. The ion exchange process or processes that are used to strengthen the glass article may include, but are not limited to, immersion in a single bath or multiple baths of like or different compositions with washing and / or annealing steps between immersions.

[0141] Upon exposure to the glass article, the ion exchange solution (e.g., KNO3 and / or NaNCh molten salt bath) may, according to embodiments, be at a temperature greater than or equal to about 350 °C and less than or equal to about 500 °C, greater than or equal to about 360 °C and less than or equal to about 450 °C, greater than or equal to about 370 °C and less than or equal to about 440 °C, greater than or equal to about 360 °C and less than or equal to about 420 °C, greater than or equal to about 370 °C and less than or equal to about 400 °C, greater than or equal to about 375 °C and less than or equal to about 475 °C, greater than or equal to about 400 °C and less than or equal to about 500 °C, greater than or equal to about 410 °C and less than or equal to about 490 °C, greater than or equal to about 420 °C and less than or equal to about 480 °C, greater than or equal to about 430 °C and less than or equal to about 470 °C, or even greater than or equal to about 440 °C and less than or equal to about 460 °C, or any and all sub-ranges between the foregoing values.

[0142] In embodiments, the glass article may be exposed to the ion exchange solution for a duration greater than or equal to about 1 hour and less than or equal to about 24 hours, greater than or equal to about 1 hour and less than or equal to about 18 hours, greater than or equal to about 1 hour and less than or equal to about 12 hours, greater than or equal to about 1 hour and less than or equal to about 6 hours, greater than or equal to about 2 hours and less than or equal to about 24 hours, greater than or equal to about 2 hours and less than or equal to about 18 hours, greater than or equal to about 2 hours and less than or equal to about 12 hours, greater than or equal to about 2 hours and less than or equal to about 6 hours, greater than or equal to about 4 hours and less than or equal to about 24 hours, greater than or equal to about 4 hours and less than or equal to about18 hours, or even greater than or equal to about 4 hours and less than or equal to about 12 hours, greater than or equal to about 4 hours and less than or equal to about 6 hours, or any and all subranges formed from any of these endpoints.

[0143] The glass composition and resultant glass article described herein may be used for a variety of applications including, for example, for cover glass or glass backplane applications in consumer or commercial electronic devices including, for example, LCD and LED displays, computer monitors, and automated teller machines (ATMs); for touch screen or touch sensor applications, for portable electronic devices including, for example, mobile telephones, personal media players, watches and tablet computers; for integrated circuit applications including, for example, semiconductor wafers; for photovoltaic applications; for architectural glass applications; for automotive or vehicular glass applications; or for commercial or household appliance applications. In embodiments, a consumer electronic device (e.g., smartphones, tablet computers, watches, personal computers, ultrabooks, televisions, and cameras), an architectural glass, and / or an automotive glass may comprise a glass article as described herein.

[0144] An example electronic device incorporating any of the glass articles disclosed herein is shown in FIG. 1. Specifically, FIG. 1 shows a consumer electronic device 100 including a housing 102 having front 104, back 106, and side surfaces 108; electrical components (not shown) that are at least partially inside or entirely within the housing and including at least a controller, a memory, and a display 110 at or adjacent to the front surface of the housing; and a cover substrate 112 at or over the front surface of the housing such that it is over the display. In embodiments, at least a portion of at least one of the cover substrate 112 and the housing 102 may include any of the glass articles disclosed herein.Examples

[0145] In order that various embodiments be more readily understood, reference is made to the following examples, which are intended to illustrate various embodiments of the glass compositions described herein.

[0146] Tables 1-4 show example glass compositions (in terms of mol%) and the respective properties of the glass compositions. Glass articles were formed from example glass compositionsE1-E247. Tables 1 and 2 encompass the low MgO embodiments described herein. Tables 3 and 4 encompass the high MgO embodiments described herein.

[0147] The mechanical properties (i.e., Young’s modulus, shear modulus, and Poisson’s ratio) of Examples El -El 34 in Table 1 and Examples E205-E227 in Table 3 were measured using Brillouin scattering (BRS). The mechanical properties of Examples E135-E204 in Table 2 and Examples E228-E247 in Table 4 were measured using resonant ultrasound spectroscopy (RUS) in accordance with ASTM C623.

[0148] BRS is measured using a tandem interferometer at 90 degrees and 532 nm excitation. The Brilluoin frequency shift lies in GHz frequency range and is related to material parameters and angle between excitation and scattering beam as:A / = (2 n sin q> / 2)V / A©, where n is refractive index, V is speed of sound, cp is angle between excitation and scattering beams, Ao is wavelength of light. Both longitudinal and transverse peaks are typically observed in solid materials, which allows for both longitudinal and transverse speeds of sound. When the angle is 180 degrees, one cannot observe transverse peaks, but the signal is very large and may be used in the test for better accuracy. Speed of sound is related to mechanical properties and density of the material. Using Brilluoin spectroscopy and knowing density, the speed of sound may be obtained and all major mechanical properties of the material such as Young’s modulus, shear modulus, and Poisson ratio may be derived therefrom.

[0149] For the purposes of this disclosure, BRS measurements are included in Tables 1 and 3 to provide a general scope of the Young’s moduli achieved by glass compositions and resultant glass articles disclosed herein. The BRS measurement values may be converted to RUS measured values according to the following formula: RUS value = BRS value / 1.0502. Except for the values provided in Tables 1 and 3, Young’ s modulus values provided herein, including those in the claims, are measured using RUS in accordance with ASTM C623.

[0150] Table 1Example El E2 E3 E4 E5SiO253.89 54.91 54.24 55.7 54.53 AI2O3 22.23 22.36 22.31 22.62 22.35 B2O3 Li2O Na2O 0.12 0.12 0.11 0.13 0.12 MgO 7.85 6.33 5.46 4.44 4.65 CaO 0.09 0.09 0.08 0.08 0.08 Y2O3 15.80 15.40 15.61 15.39 15.42 ZrO20.76 - 1.61 0.92 Nb2O5 2.15 - 1.91 TCI2O5 Total 99.98 99.97 99.96 99.97 99.98Y2O3 + MgO + ZrO223.65 22.49 23.22 21.44 22.90 + Nb2O5+ Ta2O5 Density (g / cm3) 3.456 3.458 3.503 3.491 Refractive Index (at 589.3) 1.661 1.677 1.686 1.681 1.686 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 129 133 128 131 130 Shear Modulus (GPa, BRS) 50.4 51.8 50.1 51.2 50.9 Poisson ’s Ratio (BRS) 0.282 0.283 0.281 0.282 0.281 Liquidus Temperature (°C) 1378 1379 >1450 1370 1403

[0151] Table ! cont.Example E6 E7 E8 E9 E10SiO254.06 56.23 55.17 55.01 53.88 AI2O3 22.40 22.92 22.66 22.49 22.3 B2O3 Li2O Na2O 0.13 0.13 0.12 0.12 0.12 MgO 3.88 2.49 2.52 2.10 2.46 CaO 0.07 0.08 0.06 0.06 0.06 Y2O3 15.48 15.49 15.25 15.44 15.41 ZrO22.62 2.31 0.91 Nb2O5 3.97 - 1.87 3.84 5.76 TCI2O5 Total 99.99 99.96 99.96 99.97 99.99Y2O3 + MgO + ZrO223.33 20.60 21.95 22.29 23.63 + Nb2O5+ Ta2O5 Density (g / cm3) 3.501 - 3.534 3.548 3.549 Refractive Index (at 589.3) 1.701 1.683 1.702 1.710 1.716 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 128 132 131 130 129 Shear Modulus (GPa, BRS) 50.1 51.4 51.1 50.8 50.2 Poisson ’s Ratio (BRS) 0.280 0.281 0.282 0.280 0.279 Liquidus Temperature (°C)

[0152] Table 1 cont.Example Ell Ell E13 E14 E15SiO256.98 56.51 55.79 54.96 44.40 AI2O3 22.93 22.88 22.74 22.52 27.55 B2O3 Li2O 7.89 Na2O 0.14 0.13 0.13 0.12 MgO 0.21 0.20 0.14 0.14 5.67 CaO 0.08 0.06 0.05 0.05 Y2O3 15.57 15.43 15.35 15.33 14.42 ZrO24.07 2.82 1.96 1.14 Nb2O5 1.94 3.81 5.71 TCI2O5 Total 99.98 99.97 99.97 99.97 99.92Y2O3 + MgO + ZrO219.85 20.39 21.26 22.32 20.09 + Nb2O5 + Ta2O5 Density (g / cm3) 3.521 3.574 3.581 3.585 3.299 Refractive Index (at 589.3) 1.687 1.705 1.711 1.722 1.663 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 132 132 131 129 124 Shear Modulus (GPa, BRS) 51.4 51.4 51.2 50.5 48.5 Poisson ’s Ratio (BRS) 0.280 0.280 0.279 0.278 0.277 Liquidus Temperature (°C) >1500

[0153] Table 1 cont.Example E16 E17 E18 E19 E20SiO244.40 43.18 45.27 43.22 42.18 AI2O3 27.51 26.75 27.71 27.02 26.52 B2O3 Li2O 7.87 7.57 7.87 7.60 7.38 Na2O MgO 4.66 4.60 2.94 3.39 3.42 CaO Y2O3 14.27 16.39 14.28 16.15 17.90 ZrO21.24 - 1.88 1.20 Nb2O5 1.44 - 1.36 2.54 TCI2O5 Total 99.93 99.93 99.94 99.94 99.94Y2O3 + MgO + ZrO220.16 22.43 19.10 22.10 23.86 + Nb2O5 + Ta2O5 Density (g / cm3) 3.322 3.335 3.358 3.361 3.378 Refractive Index (at 589.3) 1.668 1.676 1.678 1.681 1.690 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 123 122 124 126 124 Shear Modulus (GPa, BRS) 48.2 47.9 48.5 49.2 48.4 Poisson ’s Ratio (BRS) 0.276 0.277 0.275 0.275 0.275 Liquidus Temperature (°C) >1500 >1500 >1500 >1450 >1450

[0154] Table 1 cont.Example Ell Ell E13 E14 E15SiO243.77 42.61 45.42 45.95 45.49 AI2O3 27.25 26.85 29.59 30.44 29.65 B2O3 Li2O 7.58 7.44 Na2O 0.11 0.09 MgO 2.07 1.75 8.78 6.26 6.37 CaO Y2O3 15.93 17.97 16.00 15.92 16.52 ZrO21.98 0.89 - 1.25 Nb2O5 1.38 2.44 - - 1.87 TCI2O5 Total 99.95 99.95 99.90 99.91 99.91Y2O3 + MgO + ZrO221.34 23.05 24.78 23.44 24.76 + Nb2O5 + Ta2O5 Density (g / cm3) 3.385 3.420 3.446 3.491 3.505 Refractive Index (at 589.3) 1.687 1.695 1.674 1.685 1.691 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 123 123 132 132 131 Shear Modulus (GPa, BRS) 48.3 48.3 51.2 51.3 51.2 Poisson ’s Ratio (BRS) 0.274 0.275 0.284 0.284 0.283 Liquidus Temperature (°C) >1450 >1450

[0155] Table 1 cont.Example E26 E27 E28 E29 E30SiO246.29 45.78 46.32 46.76 46.49 AI2O3 30.94 30.42 29.65 31.17 30.58 B2O3 Li2O Na2O 0.11 0.02 - 0.12 0.03 MgO 4.63 4.19 4.93 2.81 2.32 CaO Y2O3 15.87 16.47 16.74 15.97 16.45 ZrO22.08 1.27 - 3.10 2.23 Nb2O5 1.78 2.27 - 1.83 TCI2O5 Total 99.92 99.93 99.92 99.92 99.93Y2O3 + MgO + ZrO222.58 23.71 23.95 21.88 22.83 + Nb2O5 + Ta2O5 Density (g / cm3) 3.524 3.544 3.548 3.557 3.583 Refractive Index (at 589.3) 1.695 1.699 1.707 1.700 1.712 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 133 130 130 132 133 Shear Modulus (GPa, BRS) 51.6 50.7 50.8 51.1 51.9 Poisson ’s Ratio (BRS) 0.285 0.284 0.284 0.286 0.285 Liquidus Temperature (°C)

[0156] Table 1 cont.Example E31 E32 E33 E34 E35SiO246.44 46.01 46.68 46.70 46.50 AI2O3 29.93 29.56 32.70 30.94 30.85 B2O3 Li2O Na2O 0.15 0.03 MgO 2.37 2.83 0.08 0.09 0.09 CaO Y2O3 16.51 16.41 15.89 16.37 16.35 ZrO21.36 - 4.42 3.75 2.49 Nb2O5 3.32 5.11 - 2.06 3.66 TCI2O5 Total 99.94 99.93 99.93 99.94 99.94Y2O3 + MgO + ZrO223.57 24.35 20.40 22.27 22.60 + Nb2O5 + Ta2O5 Density (g / cm3) 3.585 3.590 3.587 3.625 3.631 Refractive Index (at 589.3) 1.716 1.726 1.703 1.725 1.728 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 132 130 136 134 134 Shear Modulus (GPa, BRS) 51.5 50.8 52.9 52.3 52.0 Poisson ’s Ratio (BRS) 0.283 0.284 0.283 0.285 0.285 Liquidus Temperature (°C)

[0157] Table 1 cont.Example E36 E37 E38 E39 E40SiO246.43 44.94 44.18 44.24 43.62 AI2O3 30.16 30.00 29.25 29.30 28.68 B2O3 Li2O Na2O MgO 0.06 0.06 0.06 0.06 0.06 CaO Y2O3 16.24 17.00 16.24 16.30 15.68 ZrO21.76 - 2.27 - 3.96 Nb2O5 5.29 8.00 8.00 10.10 8.00 TCI2O5 Total 99.95 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO223.35 25.06 26.57 26.46 27.70 + Nb2O5 + Ta2O5 Density (g / cm3) 3.642 3.613 3.647 3.731 3.674 Refractive Index (at 589.3) 1.736 1.736 1.738 1.743 1.760 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 133 132 133 138 130 Shear Modulus (GPa, BRS) 51.6 51.49 52.08 53.78 50.47 Poisson ’s Ratio (BRS) 0.285 0.281 0.281 0.279 0.284 Liquidus Temperature (°C)

[0158] Table 1 cont.Example E41 E42 E43 E44 E45SiO243.57 43.05 43.01 42.27 42.27 AI2O3 28.63 28.11 28.07 27.34 27.34 B2O3 Li2O Na2O MgO 0.06 0.06 0.06 0.06 0.06 CaO Y2O3 15.63 15.11 15.07 14.33 14.33 ZrO22.16 5.67 3.83 8.00 5.87 Nb2O5 9.95 8.00 9.96 8.00 10.13 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO227.80 28.84 28.92 30.39 30.39 + Nb2O5 + Ta2O5 Density (g / cm3) 3.744 3.732 3.743 3.747 3.77 Refractive Index (at 589.3) 1.762 1.759 1.773 1.756 1.779 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 131 133 134 137 136 Shear Modulus (GPa, BRS) 51.22 51.9 52.0 53.5 53.0 Poisson ’s Ratio (BRS) 0.282 0.283 0.284 0.281 0.283 Liquidus Temperature (°C)

[0159] Table 1 cont.Example E46 E47 E48 E49 E50SiO242.27 43.08 43.01 43.66 43.70 AI2O3 27.34 28.15 28.08 28.72 28.77 B2O3 Li2O Na2O MgO 0.06 0.06 0.06 0.06 0.06 CaO Y2O3 14.33 15.14 15.08 15.72 15.76 ZrO28.00 8.00 5.77 8.00 5.98 Nb2O5 8.00 5.57 8.00 3.84 5.73 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO230.39 28.77 28.91 27.62 27.53 + Nb2O5 + Ta2O5 Density (g / cm3) 3.782 3.762 3.77 3.647 3.708 Refractive Index (at 589.3) 1.777 1.763 1.773 1.738 1.750 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 137 138 137 136 135 Shear Modulus (GPa, BRS) 53.6 53.9 53.3 53.1 52.7 Poisson ’s Ratio (BRS) 0.283 0.283 0.284 0.282 0.284 Liquidus Temperature (°C)

[0160] Table 1 cont.Example E51 E52 E53 E54 E55SiO243.58 44.21 44.25 44.23 44.15 AI2O3 28.64 29.29 29.32 29.30 29.21 B2O3 Li2O Na2O MgO 0.06 0.06 0.06 0.06 0.06 CaO Y2O3 15.64 16.27 16.31 16.30 16.22 ZrO24.08 8.00 6.01 4.40 2.36 Nb2O5 8.00 2.17 4.05 5.71 8.00 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO227.78 26.50 26.43 26.47 26.64 + Nb2O5 + Ta2O5 Density (g / cm3) 3.750 3.626 3.689 3.690 3.707 Refractive Index (at 589.3) 1.764 1.706 1.737 1.753 1.760 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 136 137 137 136 135 Shear Modulus (GPa, BRS) 53.1 53.2 53.5 52.9 52.7 Poisson ’s Ratio (BRS) 0.283 0.283 0.283 0.284 0.282 Liquidus Temperature (°C)

[0161] Table ! cont.Example E56 E57 E58 E59 E60SiO244.94 44.94 44.94 44.94 42.33 AI2O3 30.00 30.00 30.00 30.00 27.33 B2O3 Li2O Na2O MgO 0.06 0.06 0.06 0.06 8.66 CaO Y2O3 17.00 17.00 17.00 17.00 14.33 ZrO28.00 5.89 4.23 2.49 7.34 Nb2O5 2.11 3.77 5.51 TCI2O5 Total 100.00 100.00 100.00 100.00 99.99Y2O3 + MgO + ZrO225.06 25.06 25.06 25.06 30.33 + Nb2O5 + Ta2O5 Density (g / cm3) 3.576 3.659 3.677 3.691 3.552 Refractive Index (at 589.3) 1.694 1.720 1.732 1.745 1.713 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 138 139 137 137 133.1 Shear Modulus (GPa, BRS) 53.7 54.2 53.4 53.5 51.7 Poisson ’s Ratio (BRS) 0.282 0.280 0.284 0.281 0.286 Liquidus Temperature (°C)

[0162] Table 1 cont.Example E61 E62 E63 E64 E65SiO242.98 43.52 44.13 42.33 42.93 AI2O3 27.98 28.52 29.13 27.33 27.93 B2O3 Li2O Na2O MgO 8.20 4.82 5.22 12.65 12.43 CaO Y2O3 14.98 15.52 16.13 14.33 14.93 ZrO25.86 7.63 5.39 Nb2O5 3.35 1.79 TCI2O5 Total 100.00 100.01 100.00 99.99 100.01Y2O3 + MgO + ZrO229.04 27.97 26.74 30.33 29.15 + Nb2O5 + Ta2O5 Density (g / cm3) 3.546 3.585 3.562 3.436 3.420 Refractive Index (at 589.3) 1.714 1.726 1.711 1.674 1.673 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 133.9 133.7 133.1 134 135 Shear Modulus (GPa, BRS) 52.0 52.0 51.7 52.2 52.4 Poisson ’s Ratio (BRS) 0.287 0.286 0.287 0.288 0.285 Liquidus Temperature (°C)

[0163] Table 1 cont.Example E66 E67 E68 E69 E70SiO242.33 42.93 43.44 42.33 43.00 AI2O3 27.33 27.94 28.44 27.33 28.00 B2O3 Li2O Na2O MgO 9.66 9.01 9.34 6.09 5.57 CaO Y2O3 14.33 14.94 15.44 14.33 15.00 ZrO2Nb2O5 6.34 5.17 3.33 9.91 8.44 TCI2O5 Total 99.99 99.99 99.99 99.99 100.01Y2O3 + MgO + ZrO230.33 29.12 28.11 30.33 29.01 + Nb2O5 + Ta2O5 Density (g / cm3) 3.456 3.474 3.440 3.494 3.488 Refractive Index (at 589.3) 1.682 1.680 1.676 1.693 1.689 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 135 136 134 137 135 Shear Modulus (GPa, BRS) 52.3 52.7 52.2 53.2 52.8 Poisson ’s Ratio (BRS) 0.286 0.286 0.286 0.286 0.282 Liquidus Temperature (°C)

[0164] Table 1 cont.Example E71 E72 E73 E74 E75SiO243.48 44.03 42.27 43.09 43.66 AI2O3 28.48 29.04 27.33 28.14 28.72 B2O3 Li2O Na2O MgO 5.48 5.78 0.06 0.06 0.06 CaO Y2O3 15.48 16.04 14.33 15.14 15.72 ZrO2Nb2O5 7.06 5.11 16.00 13.56 11.83 TCI2O5 Total 99.98 100.00 99.99 99.99 99.99Y2O3 + MgO + ZrO228.02 26.93 30.39 28.76 27.61 + Nb2O5 + Ta2O5 Density (g / cm3) 3.497 3.496 3.544 3.545 3.545 Refractive Index (at 589.3) 1.689 1.688 1.705 1.699 1.694 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 137 133 137 135 135 Shear Modulus (GPa, BRS) 53.3 51.6 53.2 52.6 52.6 Poisson ’s Ratio (BRS) 0.285 0.286 0.284 0.285 0.285 Liquidus Temperature (°C)

[0165] Table 1 cont.Example E76 E77 E78 E79 E80SiO244.22 44.94 43.05 43.62 43.69 AI2O3 29.28 30.00 28.04 28.62 28.69 B2O3 Li2O Na2O MgO 0.06 0.06 11.72 12.14 9.91 CaO Y2O3 16.28 17.00 15.04 15.62 15.69 ZrO22.14 - 2.00 Nb2O5 10.16 8.00 TCI2O5 Total 100.00 100.00 99.99 100.00 99.98Y2O3 + MgO + ZrO226.50 25.06 28.90 27.76 27.60 + Nb2O5 + Ta2O5 Density (g / cm3) 3.533 3.524 3.456 3.420 3.467 Refractive Index (at 589.3) 1.694 1.689 1.680 1.670 1.683 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 135 134 134 133 134 Shear Modulus (GPa, BRS) 52.4 52.0 52.2 51.6 52.1 Poisson ’s Ratio (BRS) 0.286 0.284 Liquidus Temperature (°C)

[0166] Table 1 cont.Example E81 E82 E83 E84 E85SiO243.60 44.19 44.25 44.24 44.18 AI2O3 28.60 29.19 29.25 29.25 29.18 B2O3 Li2O Na2O MgO 8.40 10.42 8.21 6.64 4.93 CaO Y2O3 15.60 16.19 16.24 16.24 16.18 ZrO23.8 - 2.04 3.62 5.53 Nb2O5 TCI2O5 Total 100.00 99.99 99.99 99.99 100.00Y2O3 + MgO + ZrO227.80 26.61 26.49 26.50 26.64 + Nb2O5 + Ta2O5 Density (g / cm3) 3.500 3.424 3.486 3.513 3.611 Refractive Index (at 589.3) 1.688 1.673 1.683 1.691 1.710 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 134 132 134 135 137 Shear Modulus (GPa, BRS) 52.1 51.4 51.9 52.4 53.2 Poisson ’s Ratio (BRS) 0.288 0.286 0.288 0.288 Liquidus Temperature (°C)

[0167] Table 1 cont.Example E86 E87 E88 E89 E90SiO245.00 45.00 45.00 45.00 44.94 AI2O3 30.00 30.00 30.00 30.00 30.00 B2O3 Li2O Na2O MgO 8.00 5.74 4.05 2.35 0.06 CaO Y2O3 17.00 17.00 17.00 17.00 17.00 ZrO22.25 3.94 5.65 8.00 Nb2O5 TCI2O5 Total 100.00 99.99 99.99 100.00 100.00Y2O3 + MgO + ZrO225.00 24.99 24.99 25.00 25.06 + Nb2O5 + Ta2O5 Density (g / cm3) 3.545 3.451 3.494 3.536 3.572 Refractive Index (at 589.3) 1.697 1.674 1.687 1.693 1.700 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 136 133 134 135 136 Shear Modulus (GPa, BRS) 52.9 51.7 52.0 52.4 52.7 Poisson ’s Ratio (BRS) 0.287 0.288 0.288 0.287 0.287 Liquidus Temperature (°C)

[0168] Table 1 cont.Example E91 E92 E93 E94 E95SiO242.97 43.61 43.63 43.49 44.19 AI2O3 27.96 28.51 28.63 28.49 29.19 B2O3 Li2O Na2O MgO 12.21 12.17 10.31 9.05 10.44 CaO Y2O3 14.96 15.51 15.63 15.49 16.19 ZrO2Nb2O5 1.89 - 1.78 3.47 TCI2O5 Total 99.99 99.80 99.98 99.99 100.01Y2O3 + MgO + ZrO229.06 27.68 27.72 28.01 26.63 + Nb2O5 + Ta2O5 Density (g / cm3) 3.458 3.418 3.474 3.515 3.436 Refractive Index (at 589.3) 1.688 1.677 1.685 1.701 1.673 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 134 134 134 135 134 Shear Modulus (GPa, BRS) 52.0 51.9 52.1 52.3 52.1 Poisson ’s Ratio (BRS) 0.288 0.287 0.287 0.286 0.288 Liquidus Temperature (°C)

[0169] Table 1 cont.Example E96 E97 E98 E99 E100SiO244.21 44.19 44.08 45.00 45.00 AI2O3 29.21 29.18 29.08 30.00 30.00 B2O3 Li2O Na2O MgO 8.55 7.13 5.51 8.00 5.98 CaO Y2O3 16.21 16.18 16.08 17.00 17.00 ZrO2Nb2O5 1.81 3.31 5.24 - 2.01 TCI2O5 Total 99.99 99.99 99.99 100.00 99.99Y2O3 + MgO + ZrO226.57 26.62 26.83 25.00 24.99 + Nb2O5 + Ta2O5 Density (g / cm3) 3.491 3.530 3.578 3.452 3.511 Refractive Index (at 589.3) 1.690 1.705 1.723 1.678 1.694 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 134 134 133 134 134 Shear Modulus (GPa, BRS) 51.9 52.1 51.9 52.1 52.1 Poisson ’s Ratio (BRS) 0.288 0.287 0.286 0.287 0.287 Liquidus Temperature (°C)

[0170] Table 1 cont.Example E101 E102 E103 E104 E105SiO245.00 45.00 42.33 42.33 42.33 AI2O3 30.00 30.00 27.33 27.33 27.33 B2O3 Li2O Na2O MgO 4.36 2.60 11.81 12.35 8.51 CaO Y2O3 17.00 17.00 14.33 14.33 14.33 ZrO24.19 - 7.49 Nb2O5 3.64 5.39 - 3.65 TCI2O5 Total 100.00 99.99 99.99 99.99 99.99Y2O3 + MgO + ZrO225.00 24.99 30.33 30.33 30.33 + Nb2O5 + Ta2O5 Density (g / cm3) 3.559 3.604 3.485 3.488 3.505 Refractive Index (at 589.3) 1.711 1.726 1.683 1.704 1.693 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 134 134 137 134 137 Shear Modulus (GPa, BRS) 52.0 51.9 53.3 52.1 53.1 Poisson ’s Ratio (BRS) 0.287 0.286 0.288 0.287 0.287 Liquidus Temperature (°C)

[0171] Table ! cont.Example E106 E107 E108 E109 E110SiO242.33 42.33 42.33 42.33 42.33 AI2O3 27.33 27.33 27.33 27.33 27.33 B2O3 Li2O Na2O MgO 8.37 9.23 5.03 4.87 5.04 CaO Y2O3 14.33 14.33 14.33 14.33 14.33 ZrO24.16 - 10.97 7.56 4.43 Nb2O5 3.47 6.77 - 3.57 6.53 TCI2O5 Total 99.99 99.99 99.99 99.99 99.99Y2O3 + MgO + ZrO230.33 30.33 30.33 30.33 30.33 + Nb2O5 + Ta2O5 Density (g / cm3) 3.578 3.571 3.531 3.642 3.682 Refractive Index (at 589.3) 1.718 1.731 1.694 1.724 1.745 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 135 119 113 133 137 Shear Modulus (GPa, BRS) 52.4 46.4 43.9 51.6 53.2 Poisson ’s Ratio (BRS) 0.286 0.285 0.287 0.290 0.288 Liquidus Temperature (°C)

[0172] Table 1 cont.Example Elll E112 E113 E114 E115SiO242.27 46.79 48.39 50.10 50.66 AI2O3 27.33 22.75 22.15 22.94 22.25 B2O3 Li2O Na2O 0.12 0.11 0.12 0.12 MgO 0.06 12.27 12.26 7.91 8.97 CaO 0.12 0.11 0.09 0.09 Y2O3 14.33 15.48 15.51 15.63 15.49 ZrO211.97 2.43 - 1.89 Nb2O5 4.02 - 1.45 1.30 2.41 TCI2O5 Total 99.98 99.96 99.98 99.98 99.99Y2O3 + MgO + ZrO230.38 30.18 29.22 26.73 26.87 + Nb2O5 + Ta2O5 Density (g / cm3) 3.641 . . . . Refractive Index (at 589.3) 1.726 . . . . SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 138 136 132 134 130 Shear Modulus (GPa, BRS) 53.6 52.7 51.2 51.9 50.6 Poisson ’s Ratio (BRS) 0.285 0.288 0.286 0.287 0.285 Liquidus Temperature (°C)

[0173] Table 1 cont.Example E116 E117 E118 E119 E120SiO251.74 53.69 55.41 57.26 46.83 AI2O3 22.52 22.17 22.75 22.29 22.80 B2O3 Li2O Na2O 0.12 0.12 0.12 0.11 0.12 MgO 5.25 4.80 0.08 0.05 12.00 CaO 0.07 0.07 0.05 0.03 0.13 Y2O3 15.37 15.41 15.21 15.04 15.50 ZrO22.40 - 2.61 - 2.60 Nb2O5 2.50 3.74 3.75 5.20 TCI2O5 Total 99.97 100.00 99.98 99.98 99.98Y2O3 + MgO + ZrO225.52 23.95 21.65 20.29 30.10 + Nb2O5 + Ta2O5 Density (g / cm3) Refractive Index (at 589.3) SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 132 128 130 124 136 Shear Modulus (GPa, BRS) 51.4 49.7 50.7 48.3 52.8 Poisson ’s Ratio (BRS) 0.284 0.283 0.282 0.282 0.289 Liquidus Temperature (°C)

[0174] Table 1 cont.Example E121 E122 E123 E124 E125SiO245.48 47.76 46.99 48.15 46.91 AI2O3 22.21 23.33 22.91 23.47 22.88 B2O3 Li2O Na2O 0.12 0.12 0.12 0.13 0.13 MgO 13.08 8.80 8.56 5.16 5.66 CaO 0.12 0.12 0.11 0.09 0.09 Y2O3 15.52 15.51 15.58 15.64 15.33 ZrO24.33 2.35 4.00 2.56 Nb2O5 3.46 - 3.34 3.34 6.41 TCI2O5 Total 99.99 99.97 99.96 99.98 99.97Y2O3 + MgO + ZrO232.06 28.64 29.83 28.14 29.96 + Nb2O5 + Ta2O5 Density (g / cm3) Refractive Index (at 589.3) SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 133 137 135 136 136 Shear Modulus (GPa, BRS) 51.7 53.1 52.5 52.9 52.6 Poisson ’s Ratio (BRS) 0.287 0.288 0.283 0.284 0.289 Liquidus Temperature (°C)

[0175] Table 1 cont.Example E126 E127 E128 E129 E130SiO244.88 46.45 46.05 47.74 46.77 AI2O3 22.95 21.63 23.59 22.08 23.82 B2O3 Li2O Na2O 0.13 0.15 0.11 0.14 0.13 MgO 11.13 12.56 7.90 8.32 4.59 CaO 0.12 0.12 0.11 0.11 0.11 Y2O3 15.63 14.20 15.76 14.32 15.63 ZrO22.91 - 4.24 2.60 6.75 Nb2O5 2.23 2.00 2.21 1.93 2.17 TCI2O5 2.88 - 2.74 Total 99.98 99.99 99.97 99.98 99.97Y2O3 + MgO + ZrO231.90 31.64 30.11 29.91 29.14 + Nb2O5 + Ta2O5 Density (g / cm3) 3.686 3.885 3.730 3.984 3.826 Refractive Index (at 589.3) SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) Shear Modulus (GPa, BRS) Poisson ’s Ratio (BRS) Liquidus Temperature (°C)

[0176] Table 1 cont.Example E131 E132 E133 E134SiO248.38 49.54 41.23 43.83 AI2O3 22.18 21.68 23.07 23.31 B2O3 Li2O Na2O 0.16 0.16 0.13 0.14 MgO 4.26 4.94 12.86 7.70 CaO 0.10 0.09 0.14 0.11 Y2O3 14.38 13.58 15.59 15.50 ZrO25.73 3.07 3.79 3.81 Nb2O5 1.97 1.79 3.17 5.57 TCI2O5 2.83 5.13 Total 99.99 99.98 99.98 99.97Y2O3 + MgO + ZrO229.17 28.51 35.41 32.58 + Nb2O5 + Ta2O5 Density (g / cm3) 4.058 4.205 3.762 3.822 Refractive Index (at 589.3) SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 139 Shear Modulus (GPa, BRS) 53.9 Poisson ’s Ratio (BRS) 0.289 Liquidus Temperature (°C)

[0177] Table !Example E135 E136 E137 E138 E139SiO255.44 55.53 56.02 54.13 54.79 AI2O3 22.57 23.15 23.03 22.67 22.75 B2O3 Li2O Na2O 0.11 0.12 0.12 0.12 MgO 5.26 2.42 0.05 4.29 2.38 CaO 0.08 0.06 0.05 0.07 0.06 Y2O3 15.76 15.86 15.90 15.78 15.89 ZrO20.76 2.85 2.32 0.86 1.69 Nb2O5 2.48 2.05 2.30 TCI2O5 Total 99.87 99.98 99.97 99.97 99.98Y2O3 + MgO + ZrO221.78 21.13 20.75 22.98 22.26 + Nb2O5 + Ta2O5 Density (g / cm3) 3.428 3.465 3.518 3.488 Refractive Index (at 589.3) 1.6725 1.6763 1.6936 1.6869 1.6918 SOC (nm / mm / MPa) 1.993 2.057 2.126 2.078 2.088 Young’s Modulus (GPa, RUS) 120 121 120 121 121 Shear Modulus (GPa, RUS) 47.2 47.4 47.3 47.6 47.4 Poisson ’s Ratio (RUS) 0.275 0.272 0.274 0.274 0.272 Liquidus Temperature (°C) Strain Point (°C) 814 831 827 813 817 Anneal Point (°C) 853 871 865 853 855 Softening Point (°C) 1016 1028 1020 1009 1012 CTE (x 10~7 / °C)

[0178] Table 2 cont.Example E140 E141 E142 E143 E144SiO254.53 44.25 42.93 45.42 46.11 AI2O3 22.71 28.17 27.81 29.85 30.47 B2O3 Li2O 8.00 8.10 Na2O 0.12 . . . . MgO 2.47 2.81 2.91 8.26 4.48 CaO 0.07 . . . . Y2O3 15.64 14.51 14.75 16.24 16.32 ZrO20.79 0.37 - - 2.40 Nb2O5 3.65 1.69 3.28 TCI2O5 Total 99.98 99.80 99.79 99.77 99.78Y2O3 + MgO + ZrO222.55 19.37 20.95 24.50 23.20 + Nb2O5 + Ta2O5 Density (g / cm3) 3.377 3.406 3.455 3.534 Refractive Index (at 589.3) 1.6981 1.675 1.689 1.678 1.687 SOC (nm / mm / MPa) 2.151 - 2.075 1.894 1.921 Young’s Modulus (GPa, RUS) 121 123 122 126 128 Shear Modulus (GPa, RUS) 47.3 48.3 48.2 49.3 49.9 Poisson ’s Ratio (RUS) 0.273 0.268 0.268 0.278 0.278 Liquidus Temperature (°C) 1515 1505 1520 1490 Strain Point (°C) 809 710 709 809 819 Anneal Point (°C) 849 747 748 847 856 Softening Point (°C) 1003 906 900 1003 1011 CTE (x 10~7 / °C) 56 50 48.3

[0179] Table 2 cont.Example E145 E146 E147 E148 E149SiO246.09 47.08 46.50 46.24 45.80 AI2O3 30.61 31.10 30.70 30.70 30.28 B2O3 Li2O Na2O MgO 2.55 0.06 0.06 2.69 0.05 CaO Y2O3 16.41 16.52 16.46 16.39 16.32 ZrO21.99 5.02 3.70 3.76 1.30 Nb2O5 2.14 - 2.39 - 6.04 TCI2O5 Total 99.79 99.79 99.81 99.78 99.79Y2O3 + MgO + ZrO223.09 21.61 22.61 22.83 23.72 + Nb2O5 + Ta2O5 Density (g / cm3) 3.554 3.551 3.59 3.532 3.625 Refractive Index (at 589.3) 1.703 1.696 1.729 1.691 1.732 SOC (nm / mm / MPa) 1.990 1.961 2.004 1.903 Young’s Modulus (GPa, RUS) 127 127 127 128 127 Shear Modulus (GPa, RUS) 49.7 49.8 49.5 50.0 49.5 Poisson ’s Ratio (RUS) 0.274 0.275 0.282 0.280 0.280 Liquidus Temperature (°C) 1480 1485 1485 1475 1540 Strain Point (°C) 819 840 826 828 812 Anneal Point (°C) 858 877 863 867 848 Softening Point (°C) 1005 1024 1011 1016 CTE (x 10~7 / °C) 49.6 49.6

[0180] Table 2 cont.Example E150 E151 E152 E153 E154SiO244.94 45.01 45.05 44.78 44.82 AI2O3 29.08 28.98 28.89 28.77 28.37 B2O3 Li2O Na2O MgO 0.06 0.06 0.05 0.06 0.06 CaO 0.04 0.05 0.05 0.06 0.06 Y2O3 15.27 14.92 14.53 14.45 13.99 ZrO22.45 1.15 3.27 2.51 Nb2O5 10.61 8.54 10.28 8.61 10.19 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO225.93 25.96 26.01 26.40 26.75 + Nb2O5 + Ta2O5 Density (g / cm3) 3.683 3.684 3.684 3.676 3.703 Refractive Index (at 589.3) 1.743 1.760 1.762 1.759 1.773 SOC (nm / mm / MPa) 2.274 Young’s Modulus (GPa, RUS) 125 127 127 128 127 Shear Modulus (GPa, RUS) 48.9 49.8 49.7 50.2 49.8 Poisson ’s Ratio (RUS) 0.277 0.274 0.281 0.273 0.272 Liquidus Temperature (°C) 1555 1555 1555 1555 1560 Strain Point (°C) 790.7 798.4 787.6 798.2 788.2 Anneal Point (°C) 826.3 834.8 822.5 834.7 823.9 Softening Point (°C) 960.5 973.1 963.8 971.7 959 CTE (x 10~7 / °C)

[0181] Table 2 cont.Example E155 E156 E157 E158 E159SiO244.19 46.24 45.62 46.82 46.20 AI2O3 28.22 30.06 29.64 30.78 30.46 B2O3 Li2O Na2O MgO 0.06 0.05 0.05 0.06 0.06 CaO 0.05 0.05 0.05 0.05 0.05 Y2O3 14.04 15.47 15.37 16.01 16.04 ZrO24.42 3.69 2.86 3.77 2.54 Nb2O5 9.02 4.43 6.41 2.51 4.64 Ta2()5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO227.54 23.65 24.69 22.34 23.28 + Nb2O5 + Ta2Os Density (g / cm3) 3.702 3.618 3.643 3.576 3.605 Refractive Index (at 589.3) 1.756 1.738 1.750 1.706 1.737 SOC (nm / mm / MPa) 2.230 2.090 2.155 2.040 Young’s Modulus (GPa, RUS) 129 127.7 127.4 127.1 126.9 Shear Modulus (GPa, RUS) 50.4 49.972 50.1 49.91 49.8 Poisson ’s Ratio (RUS) 0.274 0.275 0.272 0.273 0.275 Liquidus Temperature (°C) Strain Point (°C) 793.2 818.8 843.5 827.4 818.8Anneal Point (°C) 828.8 855.7 808.1 865.3 856.7 Softening Point (°C) 996 985.9 1034.3 999.4 CTE (x 10~7 / °C)

[0182] Table 2 cont.Example E160 E161 E162 E163 E164SiO246.81 43.05 42.67 43.49 43.29 AI2O3 30.82 27.69 27.07 27.59 27.85 B2O3 Li2O Na2O MgO 0.06 13.15 9.89 9.63 8.78 CaO 0.05 0.12 0.10 0.09 0.09 Y2O3 16.49 14.12 13.49 13.98 14.29 ZrO23.39 . . . . Nb2O5 2.39 1.88 6.77 5.22 5.69 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO222.32 29.15 30.16 28.83 28.77 + Nb2O5 + Ta2O5 Density (g / cm3) 3.585 3.462 3.566 3.548 3.552 Refractive Index (at 589.3) 1.720 1.673 1.682 1.680 1.676 SOC (nm / mm / MPa) 2.003 1.970 - 2.092 2.093 Young’s Modulus (GPa, RUS) 129.7 127 127 127 127 Shear Modulus (GPa, RUS) 50.5 49.7 49.7 49.6 49.7 Poisson ’s Ratio (RUS) 0.285 0.278 0.276 0.276 0.276 Liquidus Temperature (°C) 1465 1550 1545 1530 Strain Point (°C) 827.6 783 770.1 779.5 779.3 Anneal Point (°C) 863.5 821.7 807.4 818.1 817 Softening Point (°C) 1010.5 972.5 952.2 961.2 961.9 CTE (x 10~7 / °C)

[0183] Table 2 cont.Example E165 E166 E167 E168 E169SiO244.30 44.18 44.41 44.63 44.05 AI2O3 27.25 27.79 28.24 28.77 27.49 B2O3 Li2O Na2O MgO 6.49 5.99 5.73 6.04 12.60 CaO 0.08 0.07 0.08 0.07 0.13 Y2O3 12.63 13.70 14.46 15.20 13.83 ZrO20.00 1.91 Nb2O5 9.24 8.27 7.08 5.29 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO228.36 27.96 27.27 26.53 28.34 + Nb2O5 + Ta2O5 Density (g / cm3) 3.616 3.612 3.589 3.585 3.444 Refractive Index (at 589.3) 1.693 1.689 1.689 1.688 SOC (nm / mm / MPa) 2.210 - 2.080 1.937 Young ’s Modulus (GPa, BRS) 126.1 126.3 127.4 127.3 129.6 Shear Modulus (GPa, BRS) 49.5 49.3 49.9 49.8 50.5 Poisson ’s Ratio (BRS) 0.273 0.28 0.278 0.278 0.282 Liquidus Temperature (°C) Strain Point (°C) 762.7 775.8 783 790.4 794.9 Anneal Point (°C) 798.9 812.9 820.2 727.1 834.1 Softening Point (°C) 942.6 948.1 955.4 970.9 982.4 CTE (x 10~7 / °C)

[0184] Table 2 cont.Example E170 E171 E172 E173 E174SiO244.06 44.96 45.34 45.82 44.56 AI2O3 28.15 29.26 29.39 29.82 27.75 B2O3 Li2O Na2O MgO 12.51 0.05 0.05 0.05 9.39 CaO 0.11 0.05 0.05 0.05 0.11 Y2O3 14.40 15.57 14.87 15.89 13.60 ZrO20.76 1.31 3.94 2.02 4.60 Nb2O5 8.80 6.36 6.35 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO227.67 25.73 25.21 24.31 27.59 + Nb2O5 + Ta2O5 Density (g / cm3) 3.436 3.682 3.650 3.635 3.489 Refractive Index (at 589.3) 1.738 1.763 1.753 1.713 SOC (nm / mm / MPa) 1.896 - 2.151 2.136 Young’s Modulus (GPa, RUS) 128 126 130 127 130 Shear Modulus (GPa, RUS) 49.8 49.3 50.8 49.6 50.8 Poisson ’s Ratio (RUS) 0.281 0.277 0.277 0.276 0.280 Liquidus Temperature (°C) Strain Point (°C) 795 798 810 808 802 Anneal Point (°C) 834 834 847 844 841 Softening Point (°C) 982 971 - 989 994 CTE (x 10~7 / °C)

[0185] Table 2 cont.Example E175 E176 E177 E178 E179SiO244.91 45.02 45.65 46.07 46.33 AI2O3 28.06 28.51 28.60 28.29 28.93 B2O3 Li2O Na2O MgO 8.92 9.02 5.30 4.88 5.75 CaO 0.10 0.10 0.09 0.09 0.08 Y2O3 14.22 14.82 14.26 14.78 15.38 ZrO23.79 2.53 6.11 5.88 3.53 Nb2O5 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO226.93 26.38 25.66 25.55 24.66 + Nb2O5 + Ta2O5 Density (g / cm3) 3.492 3.476 3.525 3.528 3.509 Refractive Index (at 589.3) 1.714 - - 1.726 1.711 SOC (nm / mm / MPa) Young’s Modulus (GPa, RUS) 130 129 130 133 130 Shear Modulus (GPa, RUS) 50.6 50.5 50.7 52.1 50.7 Poisson ’s Ratio (RUS) 0.282 0.282 0.279 0.275 0.286 Liquidus Temperature (°C) Strain Point (°C) 804 804 816 817 814 Anneal Point (°C) 843 843 854 857 853 Softening Point (°C) CTE (x 10~7 / °C)

[0186] Table 2 cont.Example E180 E182 E181 E182 E183SiO247.63 44.49 47.82 47.31 47.53 AI2O3 22.57 23.36 24.70 26.68 28.83 B2O3 Li2O Na2O MgO 9.12 10.30 6.58 4.67 2.66 CaO 0.11 0.13 0.10 0.08 0.07 Y2O3 15.57 16.07 15.79 15.71 15.80 ZrO24.89 5.56 4.90 5.42 4.98 Nb2O5 TCI2O5 Total 99.89 99.91 99.89 99.87 99.87Y2O3 + MgO + ZrO229.58 31.93 27.27 25.80 23.44 + Nb2O5 + Ta2O5 Density (g / cm3) 3.587 3.635 3.574 3.571 3.550 Refractive Index (at 589.3) SOC (nm / mm / MPa) Young’s Modulus (GPa, RUS) 128 131 129 129 129 Shear Modulus (GPa, RUS) 50.1 51.1 50.4 50.4 50.3 Poisson ’s Ratio (RUS) 0.275 0.278 0.276 0.276 0.278 Liquidus Temperature (°C) Strain Point (°C) Anneal Point (°C) Softening Point (°C) CTE (x 10~7 / °C)

[0187] Table 2 cont.Example E184 E185 E186 E187 E188SiO245.48 43.80 40.07 37.40 40.42 AI2O3 22.25 23.19 26.84 27.09 28.19 B2O3 Li2O 7.68 7.59 7.86 Na2O 0.21 0.20 0.22 MgO 11.07 11.85 5.90 6.06 0.09 CaO 0.13 0.14 3.09 3.47 4.12 Y2O3 15.34 16.05 16.16 18.18 16.90 ZrO25.64 4.88 - - 2.18 Nb2O5 TCI2O5 Total 99.91 99.91 99.95 99.99 99.98Y2O3 + MgO + ZrO232.05 32.78 22.06 24.24 19.17 + Nb2O5 + Ta2O5 Density (g / cm3) 3.627 3.632 3.411 3.505 3.433 Refractive Index (at 589.3) SOC (nm / mm / MPa) Young’s Modulus (GPa, RUS) 131 131 125 128 124 Shear Modulus (GPa, RUS) 51.1 51.5 49.2 50.5 48.9 Poisson ’s Ratio (RUS) 0.278 0.276 0.272 0.269 0.266 Liquidus Temperature (°C) Strain Point (°C) Anneal Point (°C) Softening Point (°C) CTE (x 10~7 / °C)

[0188] Table 2 cont.Example E189 E190 E191 E192 E193SiO238.38 41.68 43.83 43.85 50.14 AI2O3 28.04 27.72 26.81 26.67 19.72 B2O3 1.78 Li2O 7.61 7.91 8.49 8.68 11.99 Na2O 0.23 0.07 0.08 0.09 0.07 MgO 0.11 6.05 5.45 4.51 0.06 CaO 4.48 0.08 0.07 0.07 2.05 Y2O3 18.83 16.47 15.27 16.13 14.19 ZrO22.30 . . . . Nb2O5 TCI2O5 Total 99.98 99.98 100.00 100.00 100.00Y2O3 + MgO + ZrO221.24 22.52 20.72 20.64 14.25 + Nb2O5 + Ta2O5 Density (g / cm3) 3.508 3.424 3.373 3.392 3.256 Refractive Index (at 589.3) 1.677 1.672 1.677 1.651 SOC (nm / mm / MPa) 1.884 1.900 1.875 2.071 Young’s Modulus (GPa, RUS) 126 126 123 126 113 Shear Modulus (GPa, RUS) 49.7 49.6 48.6 49.6 44.6 Poisson ’s Ratio (RUS) 0.266 0.266 0.267 0.267 0.263 Liquidus Temperature (°C) Strain Point (°C) 705 696 703 673 Anneal Point (°C) 743 734 740 710 Softening Point (°C) 901 888 892 865 CTE (x 10~7 / °C)

[0189] Table 2 cont.Example E194 E195 E196 E197 E198SiO250.26 51.87 41.28 39.02 37.28 AI2O3 19.77 19.70 26.69 26.86 26.72 B2O3 1.53 1.77 Li2O 9.89 9.81 14.06 14.01 13.90 Na2O 0.06 0.07 MgO 0.06 0.06 2.02 4.04 6.07 CaO 2.09 2.07 Y2O3 16.32 14.63 15.76 15.89 15.82 ZrO2Nb2O5 TCI2O5 Total 99.98 99.98 99.81 99.82 99.79Y2O3 + MgO + ZrO216.38 14.69 17.78 19.93 21.89 + Nb2O5 + Ta2O5 Density (g / cm3) 3.355 3.262 Refractive Index (at 589.3) 1.663 1.647 SOC (nm / mm / MPa) 1.983 2.068 1.946 1.882 1.864 Young’s Modulus (GPa, RUS) 116 113 122 124 125 Shear Modulus (GPa, RUS) 45.9 44.6 48.0 49.0 49.2 Poisson ’s Ratio (RUS) 0.266 0.261 0.264 0.265 0.266 Liquidus Temperature (°C) Strain Point (°C) 692 691 676 662 655 Anneal Point (°C) 731 729 712 698 691 Softening Point (°C) 865 881 865 853 CTE (x 10~7 / °C)

[0190] Table 2 cont.Example E199 E200 E201 E202 E203SiO240.63 43.33 43.11 45.00 44.72 AI2O3 27.08 29.30 29.20 30.77 30.64 B2O3 Li2O 14.22 . . . . Na2O MgO 1.00 0.05 2.04 0.05 2.11 CaO 0.06 0.07 0.05 0.07 Y2O3 15.99 16.62 14.66 18.28 16.34 ZrO20.90 4.30 4.57 3.45 3.75 Nb2O5 6.35 6.35 2.39 2.37 TCI2O5 Total 99.82 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO217.89 27.31 27.62 24.17 24.57 + Nb2O5 + Ta2O5 Density (g / cm3) 3.733 3.676 3.669 3.613 Refractive Index (at 589.3) SOC (nm / mm / MPa) 1.919 . . . . Young’s Modulus (GPa, RUS) 122 - Shear Modulus (GPa, RUS) 47.9 . . . . Poisson ’s Ratio (RUS) 0.268 . . . . Liquidus Temperature (°C) Strain Point (°C) Anneal Point (°C) Softening Point (°C) 862 - 986 1008 CTE (x 10~7 / °C)

[0191] Table 2 cont.Example E204SiO244.67 AI2O3 30.70 B2O3 Li2O Na2O MgO 1.03 CaO 0.06 Y2O3 16.42 ZrO23.61 Nb2O5 3.52 TCI2O5 Total 100.00Y2O3 + MgO + ZrO224.58 + Nb2O5 + Ta2O5 Density (g / cm3) 3.631 Refractive Index (at 589.3) SOC (nm / mm / MPa) Young’s Modulus (GPa, RUS) Shear Modulus (GPa, RUS) Poisson ’s Ratio (RUS) Liquidus Temperature (°C) Strain Point (°C) Anneal Point (°C) Softening Point (°C) CTE (x 10~7 / °C)

[0192] Table 3Example E205 E206 E207 E208 E209SiO242.33 42.33 42.33 43.06 42.33 AI2O3 27.33 27.33 27.33 28.06 27.33 B2O3 Li2O Na2O MgO 16.00 16.00 16.00 13.82 16.00 CaO Y2O3 14.33 14.33 14.33 15.06 14.33 ZrO2Nb2O5 TCI2O5 Total 99.99 99.99 99.99 100.00 99.99Y2O3 + MgO + ZrO230.33 30.33 30.33 28.88 30.33 + Nb2O5+ Ta2O5 Density (g / cm3) 3.386 3.388 3.390 3.405 3.391 Refractive Index (at 589.3) 1.659 1.664 1.669 1.670 1.669 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 133.7 133 133 133 134 Shear Modulus (GPa, BRS) 51.9 51.8 51.9 51.7 52.0 Poisson ’s Ratio (BRS) 0.288 0.287 0.287 - 0.288 Liquidus Temperature (°C)

[0193] Table 3 cont.Example E210 E211 E212 E213 E214SiO243.05 42.33 42.33 36.46 39.14 AI2O3 28.05 27.33 27.33 27.33 25.26 B2O3 Li2O Na2O MgO 13.84 16.00 16.00 21.87 22.34 CaO Y2O3 15.05 14.33 14.34 14.34 13.26 ZrO2Nb2O5 TCI2O5 Total 99.99 99.99 100.00 100.00 100.00Y2O3 + MgO + ZrO228.89 30.33 30.34 36.21 35.60 + Nb2O5+ Ta2O5 Density (g / cm3) 3.408 3.399 3.395 3.435 3.394 Refractive Index (at 589.3) 1.670 1.669 1.665 1.672 1.670 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 134 134 133.0 136.4 133.3 Shear Modulus (GPa, BRS) 51.9 51.9 51.7 53.1 51.8 Poisson ’s Ratio (BRS) 0.288 0.288 0.286 0.285 0.287 Liquidus Temperature (°C)

[0194] Table 3 cont.Example E215 E216 E217 E218 E219SiO242.33 40.96 38.25 39.91 38.83 AI2O3 27.33 27.33 27.33 27.33 27.33 B2O3 Li2O Na2O MgO 16.00 16.00 18.72 16.00 16.00 CaO Y2O3 14.34 15.71 15.70 16.76 17.84 ZrO2Nb2O5 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO230.34 31.71 34.42 32.76 33.84 + Nb2O5+ Ta2O5 Density (g / cm3) 3.390 3.458 3.469 3.511 3.624 Refractive Index (at 589.3) 1.665 1.674 1.679 1.679 1.690 SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 133.0 134.7 135.7 136.0 139.8 Shear Modulus (GPa, BRS) 51.8 52.3 52.7 52.8 54.3 Poisson ’s Ratio (BRS) 0.285 0.286 0.288 0.288 0.287 Liquidus Temperature (°C)

[0195] Table 3 cont.Example E220 E221 E222 E223 E224SiO245.88 41.73 45.65 43.42 38.22 AI2O3 22.50 22.33 22.27 22.26 22.76 B2O3 Li2O Na2O 0.12 0.12 0.12 0.12 0.13 MgO 15.72 15.14 16.29 16.22 18.87 CaO 0.13 0.14 0.14 0.14 0.17 Y2O3 15.62 15.18 15.52 15.57 15.42 ZrO24.40 Nb2O5 5.33 - 2.26 TCI2O5 Total 99.97 99.97 99.99 99.99 99.97Y2O3 + MgO + ZrO231.34 35.65 31.81 34.05 38.69 + Nb2O5+ Ta2O5 Density (g / cm3) 3.676 3.490 3.567 3.689 Refractive Index (at 589.3) SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 133.7 - 134 136 Shear Modulus (GPa, BRS) 51.8 - 51.9 52.5 Poisson ’s Ratio (BRS) 0.292 - 0.290 0.290 Liquidus Temperature (°C)

[0196] Table 3 cont.Example E225 E226 E227SiO239.55 42.88 40.72 AI2O3 22.21 22.44 22.44 B2O3 Li2O Na2O 0.13 0.12 0.12 MgO 19.14 17.95 16.60 CaO 0.16 0.13 0.14 Y2O3 15.54 16.50 16.50 ZrO23.50 Nb2O5 3.25 TCI2O5 Total 99.98 100.03 100.02Y2O3 + MgO + ZrO237.93 34.45 36.60 + Nb2O5+ Ta2O5 Density (g / cm3) 3.627 3.499 3.610 Refractive Index (at 589.3) SOC (nm / mm / MPa) Young ’s Modulus (GPa, BRS) 137 135 138 Shear Modulus (GPa, BRS) 53.2 52.5 53.6 Poisson ’s Ratio (BRS) 0.292 0.289 0.291 Liquidus Temperature (°C)

[0197] Table 4Example E228 E229 E230 E231 E232SiO242.53 42.44 39.53 37.50 35.50 AI2O3 27.20 26.99 22.50 22.50 22.50 B2O3 Li2O Na2O MgO 16.43 13.31 18.48 20.50 22.50 CaO 0.14 0.13 Y2O3 13.70 13.61 16.50 16.50 16.50 ZrO2Nb2O5 3.53 2.99 3.00 3.00 TCI2O5 Total 100.00 100.00 100.00 100.00 100.00Y2O3 + MgO + ZrO230.13 30.45 37.97 40.00 42.00 + Nb2O5 + Ta2O5 Density (g / cm3) 3.396 3.492 Refractive Index (at 589.3) SOC (nm / mm / MPa) 1.895 2.033 Young’s Modulus (GPa, RUS) 127 127 - - Shear Modulus (GPa, RUS) 49.4 49.7 Poisson ’s Ratio (RUS) 0.28 0.279 Liquidus Temperature (°C) 1500 1475 Strain Point (°C) 785 777 - - Anneal Point (°C) 823 815 - - Softening Point (°C) 976 962 - - CTE (x 10~7 / °C)

[0198] Table 4 cont.Example E233 E234 E235 E236 E237SiO239.50 37.50 35.50 43.00 41.00 AI2O3 24.50 26.50 26.50 22.50 22.50 B2O3 Li2O Na2O MgO 16.50 16.50 18.50 18.00 20.00 CaO Y2O3 16.50 16.50 16.50 16.46 16.46 ZrO2Nb2O5 3.00 3.00 3.00 TCI2O5 Total 100.00 100.00 100.00 99.96 99.96Y2O3 + MgO + ZrO236.00 36.00 38.00 34.46 36.46 + Nb2O5 + Ta2O5 Density (g / cm3) Refractive Index (at 589.3) SOC (nm / mm / MPa) Young’s Modulus (GPa, RUS) Shear Modulus (GPa, RUS) Poisson ’s Ratio (RUS) Liquidus Temperature (°C) Strain Point (°C) Anneal Point (°C) Softening Point (°C) CTE (x 10~7 / °C)

[0199] Table 4 cont.Example E238 E239 E240 E241 E242SiO239.00 43.00 41.00 39.00 40.80 AI2O3 22.50 24.50 26.50 26.50 22.50 B2O3 Li2O Na2O MgO 22.00 16.00 16.00 18.00 16.70 CaO Y2O3 16.46 16.46 16.46 16.50 16.45 ZrO23.50 Nb2O5 TCI2O5 Total 99.96 99.96 99.96 100.00 99.95Y2O3 + MgO + ZrO238.46 32.46 32.46 34.50 36.65 + Nb2O5 + Ta2O5 Density (g / cm3) Refractive Index (at 589.3) SOC (nm / mm / MPa) Young’s Modulus (GPa, RUS) Shear Modulus (GPa, RUS) Poisson ’s Ratio (RUS) Liquidus Temperature (°C) Strain Point (°C) Anneal Point (°C) Softening Point (°C) CTE (x 10~7 / °C)

[0200] Table 4 cont.Example E243 E244 E245 E246 E247SiO238.80 36.80 40.80 38.80 36.80 AI2O3 22.50 22.50 24.50 26.50 26.50 B2O3 Li2O Na2O MgO 18.70 20.70 14.70 14.70 16.70 CaO Y2O3 16.45 16.45 16.45 16.45 16.50 ZrO23.50 3.50 3.50 3.50 3.50 Nb2O5 TCI2O5 Total 99.95 99.95 99.95 99.95 100.00Y2O3 + MgO + ZrO238.65 40.65 34.65 34.65 36.70 + Nb2O5 + Ta2O5 Density (g / cm3) Refractive Index (at 589.3) SOC (nm / mm / MPa) Young’s Modulus (GPa, RUS) Shear Modulus (GPa, RUS) Poisson ’s Ratio (RUS) Liquidus Temperature (°C) Strain Point (°C) Anneal Point (°C) Softening Point (°C) CTE (x 10~7 / °C)

[0201] As indicated by the example glass compositions in Tables 1-4, the glass compositions and the resultant glass articles described herein have a relatively high Young’s modulus.

[0202] Referring now to Table 5, glass articles having a 0.5 mm thickness and formed from example glass compositions E190-E196 were subjected to ion ion-exchange for the indicated time at 600 °C in 70.5% NaNCh and 29.5% Na2SC>4 (100% NaNCh bath equivalent) molten salt bath with 0.25 wt% salicic acid. The percent weight gain of the articles after ion exchange is shown in Table 4.

[0203] Table 5Example E190 E191 E192 E193 E194 E1969 hours 0.04 0.06 0.03 0.57 0.31 0.4725 hours 0.05 0.16 0.10 1.17 0.55 0.9236 hours 0.10 - 0.10 1.34 0.77 1.0849 hours 0.13 0.19 0.09

[0204] It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.

Claims

Claims1. A glass of composition comprising: greater than or equal to 20 mol% and less than or equal 60 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 0.05 mol% and less than 13.3 mol% MgO, wherein a total sum of concentrations of oxide components in the glass composition is equal to 100 mol%.

2. The glass of claim 1, wherein the composition comprises greater than or equal to 14 mol% and less than or equal to 18 mol% Y2O3.

3. The glass of claim 1 or claim 2, wherein the composition comprises greater than or equal to 0.1 mol% and less than or equal to 11 mol% MgO.

4. The glass of any one of claims 1-3, wherein the composition comprises greater than or equal to 25 mol% and less than or equal to 55 mol% SiO2.

5. The glass of any one of claims 1-4, wherein the composition comprises greater than or equal to 17 mol% and less than or equal to 35 mol% AI2O3.

6. The glass of any one of claims 1-5, wherein the composition comprises greater than or equal to 1 mol% and less than or equal to 20 mol% Li2O.

7. The glass of any one of claims 1-6, wherein the composition comprises greater than or equal to 0.1 mol% and less than or equal to 5 mol% B2O3.

8. A glass of composition comprising: greater than or equal to 20 mol% and less than or equal 46 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3;greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 13.3 mol% and less than or equal to 26 mol% MgO, wherein a total sum of concentrations of oxide components in the glass composition is equal to 100 mol%.

9. The glass of claim 8, wherein the composition comprises greater than or equal to 14 mol% and less than or equal to 18 mol% Y2O3.

10. The glass of claim 8 or claim 9, wherein the composition comprises greater than or equal to 15 mol% and less than or equal to 24 mol% MgO.

11. The glass of any one of claims 8-10, wherein the composition comprises greater than or equal to 25 mol% and less than or equal to 44 mol% SiO2.

12. The glass of any one of claims 8-11, wherein the composition comprises greater than or equal to 17 mol% and less than or equal to 35 mol% AI2O3.

13. A glass article comprising the glass of any one of claims 1-12.

14. A consumer electronic device comprising: a housing having a front surface, a back surface, and side surfaces; and electrical components provided at least partially within the housing, the electrical components including at least a controller, a memory, and a display, the display being provided at or adjacent the front surface of the housing; wherein the display comprises the glass article of claim 13.

15. A method of forming a glass article, the method comprising: heating a glass composition, the glass composition comprising: greater than or equal to 20 mol% and less than or equal 60 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; andgreater than or equal to 0.05 mol% and less than 13.3 mol% MgO, wherein a total sum of concentrations of oxide components in the glass composition is equal to 100 mol%; and cooling the glass composition at a cooling rate greater than 50 °C / s to form the glass article.

16. The method of claim 15, wherein the method comprises pressing and plastically deforming a gob of the glass composition.

17. The method of claim 15 or claim 16, further comprising strengthening the glass article in an ion exchange bath at a temperature greater than or equal to 350 °C to less than or equal to 500 °C for a time period greater than or equal to 1 hour to less than or equal to 24 hours to form an ion exchanged glass article.

18. A method of forming a glass article, the method comprising: heating a glass composition, the glass composition comprising: greater than or equal to 20 mol% and less than or equal 46 mol% SiCh; greater than or equal to 15 mol% and less than or equal to 40 mol% AI2O3; greater than or equal to 12.5 mol% and less than or equal to 20 mol% Y2O3; and greater than or equal to 13.3 mol% and less than or equal to 26 mol% MgO, wherein a total sum of concentrations of oxide components in the glass composition is equal to 100 mol%; and cooling the glass composition at a cooling rate greater than 50 °C / s to form the glass article.

19. The method of claim 18, wherein the method comprises pressing and plastically deforming a gob of the glass composition.

20. The method of claim 18 or claim 19, further comprising strengthening the glass article in an ion exchange bath at a temperature greater than or equal to 350 °C to less than or equal to 500 °C for a time period greater than or equal to 1 hour to less than or equal to 24 hours to form an ion exchanged glass article.

Images