Glass-based articles comprising metal oxide concentration gradients

Abstract

To provide a thin glass-based article exhibiting improved fracture resistance.SOLUTION: 45 mol% to 75 mol% of SiO2, 5 mol% to 20 mol% of Al2O3, 0.1 mol% to 6 mol% of B2O3, 1 mol% to 8 mol% of Na2O, 2 mol% to 10 mol% of Li2O, less than 3 mol% of K2O, up to 8 mol% of oxides of alkaline earth metals, and less than 1 mol% of ZrO2, when the total of Li2O, Na2O, and K2O is R2O, the ratio of Li2O (mol%) to R2O (mol%) is greater than 0.5, and the total of R2O is 5 mol% or more and 15 mol% or less.SELECTED DRAWING: None

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a divisional application of Japanese Patent Application No. 2018-552206, which claims the benefit of priority under 35 U.S.C. Section 119 of U.S. Provisional Application No. 62 / 366338, filed July 25, 2016, and U.S. Provisional Application No. 62 / 320077, filed April 8, 2016. [Technical Field]

[0002] The present disclosure relates to glass-based articles that exhibit improved damage resistance, including improved fracture resistance, and more particularly to glass and glass-ceramic articles that exhibit a non-zero metal oxide concentration gradient, i.e., a concentration that varies along a substantial portion of their thickness. [Background technology]

[0003] Glass-based articles are often subjected to high impacts that can introduce large flaws into the surface of the article. Such flaws can extend to a depth of approximately 200 micrometers (microns or μm) from the surface. Because heat-tempered glass often exhibits a large compressive stress (CS) layer (e.g., approximately 21% of the total thickness of the glass), which can prevent the flaws from propagating further into the glass, heat-tempered glass has traditionally been used to prevent defects caused by the introduction of such flaws into the glass. An example of a stress profile generated by heat tempering is shown in FIG. 1. In FIG. 1, a heat-treated glass article 100 includes a first surface 101, a thickness t1, and a surface CS 110. The heat-treated glass article 100 exhibits a CS that decreases from the first surface 101 to a depth of compression (DOC) 130, as defined herein, at which the stress changes from compressive to tensile, leading to a maximum central tension (CT) 120.

[0004] Thermal tempering is currently limited to thick glass-based articles (i.e., glass-based articles having a thickness t1 of about 3 millimeters or greater) because a sufficient thermal gradient must be formed between the center and surface of such articles to achieve thermal strengthening and the desired residual stresses. Such thick articles are undesirable or impractical in many applications, such as displays (e.g., consumer electronics including cell phones, tablets, computers, navigation systems, etc.), building components (e.g., windows, shower panels, countertops, etc.), transportation equipment (e.g., automobiles, trains, aircraft, ships, etc.), electrical appliances, or any application requiring a thin, lightweight article with good fracture resistance.

[0005] While chemical strengthening is not limited by the thickness of the glass-based article in the same way as thermal tempering, known chemically strengthened glass-based articles do not exhibit the stress profile of thermally tempered glass-based articles. An example of a stress profile produced by chemical strengthening (e.g., by an ion exchange process) is shown in FIG. 2. In FIG. 2, chemically strengthened glass-based article 200 has a first surface 201, a thickness t2, and a surface CS 210. Glass-based article 200 exhibits a CS that decreases from first surface 201 to a DOC 230, as defined herein, at which depth the stress changes from compressive to tensile stress, reaching a maximum CT 220. As shown in FIG. 2, such a profile exhibits a substantially flat CT region, or a CT region with a constant or near-constant tensile stress along at least a portion of the CT region. Often, known chemically strengthened glass-based articles exhibit a lower maximum CT value compared to the maximum central value shown in FIG. 1. Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, there is a need for thin glass-based articles that exhibit improved fracture resistance. [Means for solving the problem]

[0007] A first aspect of the present disclosure relates to a glass-based article including a first surface defining a thickness (t) and a second surface opposite the first surface, the glass-based article having a non-zero metal oxide concentration that varies along a thickness range from about 0·t to about 0.3·t, and a central tension (CT) region including a maximum CT of 71.5 / √(t) or greater, wherein, when the glass-based article is broken using a 5.08 cm × 5.08 cm (2 inch × 2 inch) square sample using the "Fragility Test" described in Z. Tang et al., "Automated Apparatus for Measuring the Frangibility and Fragmentation of Strengthened Glass." Experimental Mechanics (2014) 54:903-912, the glass-based article breaks into at least two fragments per square inch. The number of fragments is divided by the area (square inches) of the tested sample. As used herein, the change in metal oxide concentration can be referred to as a metal oxide concentration gradient. In one or more embodiments, the concentration of metal oxide is non-zero and varies along the entire thickness. In one or more embodiments, the CT region can comprise metal oxide that is non-zero and varies along the thickness range of about 0·t to about 0.3·t. The glass-based article of one or more embodiments can have a thickness t of about 3 millimeters (mm) or less, 2 mm or less, or about 1 mm or less.

[0008] A second aspect of the present disclosure relates to a glass-based article including a first surface defining a thickness (t) of about 3 millimeters or less and a second surface opposite the first surface, the glass-based article having a stress profile extending through the thickness, wherein all points on the stress profile between the thickness ranges of about 0·t to 0.3·t and greater than 0.7·t to t have a tangent with a slope of an absolute value greater than about 0.1 MPa / micrometer, the stress profile having a maximum C, DOC, and a maximum C equal to or greater than 71.5 / √(t), wherein the ratio of maximum C to the absolute value of maximum C is in the range of about 0.01 to about 0.2, and the DOC is equal to or greater than about 0.1·t.

[0009] A third aspect of the present disclosure relates to a glass-based article comprising a first surface defining a thickness (t) and a second surface opposite the first surface, having a concentration of metal oxide that is non-zero and varies along a thickness range of from about 0·t to about 0.3·t (or from about 0·t to about 0.4·t, or from about 0·t to about 0.45·t), having a surface compressive stress greater than about 200 MPa or greater, and having a CT region with a maximum CT of 71.5 / √(t) or greater.

[0010] A fourth aspect of the present disclosure is a glass-based article including a first surface defining a thickness (t) and a second surface opposite the first surface, the glass-based article including a metal oxide forming a concentration gradient, wherein the concentration of the metal oxide decreases from the first surface to a value at a point between the first surface and the second surface, and increases from that value to the second surface, where the concentration of the metal oxide at the point is non-zero, and the glass-based article has a thermal conductivity of about 0 J / m 2 More than 20J / m 2 A glass-based article having a stored tensile energy of less than about 70 GPa and a Young's modulus of about 70 GPa or greater.

[0011] A fifth aspect of the present disclosure is a glass-based article comprising a first surface defining a thickness (t) of about 3 millimeters or less and a second surface opposite the first surface, the glass-based article having a stress profile extending through the thickness, wherein all points on the stress profile between a thickness range of about 0·t to 0.3·t and greater than 0.7·t have a tangent with a slope of an absolute value greater than about 0.1 MPa / micrometer, the stress profile having a maximum C, a DOC, and a maximum C, wherein the ratio of the maximum C to the absolute value of the maximum C is within the range of about 0.01 to about 0.2, the DOC is about 0.1·t or greater, and the glass-based article has a stress profile of about 0 J / m 2 More than 20J / m 2 The present invention relates to a glass-based article having a stored tensile energy of less than about 70 GPa and a Young's modulus of about 70 GPa or greater. In one or more embodiments, the glass-based article has a non-zero concentration of metal oxide that varies continuously along its entire thickness. In some cases, the non-zero concentration of metal oxide varies continuously along a thickness of less than about 10 micrometers.

[0012] A sixth aspect of the present disclosure relates to a glass-based article having a stress profile comprising a CS region and a CT region, the CT region being represented by the equation: Stress (x)=MaxT-(((CTn·(n+1)) / 0.5n)·|(x / t)-0.5|n) where MaxT is the maximum tensile value, CTn is a positive value in MPa less than or equal to MaxT, x is the position along the thickness (t) in micrometers, and n is between 1.5 and 5. In some embodiments, the maximum CT value is in the range of about 50 MPa to about 250 MPa, and the maximum CT value is at a depth in the range of about 0.4·t to about 0.6·t. In one or more embodiments, from a thickness in the range of about 0·t to about 0.1·t, the stress profile comprises a slope in the range of about 20 MPa / micrometer to about 200 MPa / micrometer. In one or more embodiments, the stress profile is approximated by a plurality of error functions measured at 0.5·t to the surface.

[0013] According to one or more embodiments of the glass-based articles described herein, monovalent ions of a metal oxide generate stress along a thickness range (i.e., from about 0·t to about 0.3·t, from about 0·t to about 0.4·t, or from about 0·t to about 0.45·t). In one or more embodiments, the concentration of the metal oxide decreases from the first surface to a value at a point between the first and second surfaces, and then increases from that value to the second surface.

[0014] In one or more embodiments, the concentration of metal oxide is about 0.05 mol % or greater throughout the thickness. For example, in one or more embodiments, the concentration of metal oxide at the first surface is about 1.5 times (or greater) the concentration of metal oxide at a depth corresponding to about 0.5 t. In exemplary embodiments, the glass-based article has a total metal oxide concentration in the range of about 1 mol % to about 15 mol %. In one or more embodiments, the metal oxide may include, for example, one or more of Li2O, Na2O, KO, Rb2O, and Cs2O. In one or more embodiments, the monovalent ions of the metal oxide have the largest ionic diameter of all the metal oxides in the glass-based substrate or article.

[0015] In one or more embodiments, the CT region comprises a metal oxide that is non-zero and varies along the thickness range from about 0·t to about 0.3·t. In one or more embodiments of the glass-based articles described herein, the maximum CT is 71.5 / √(t) (MPa) or greater, where "71.5" is in units of MPa·(mm) and "t" is in millimeters (mm).

[0016] The glass-based article of some embodiments has a first metal oxide concentration and a second metal oxide concentration. In some embodiments, the first metal oxide concentration is in the range of about 0 mol% to about 15 mol% from a first thickness range of about 0 t to about 0.5 t. In some embodiments, the second metal oxide concentration is in the range of about 0 mol% to about 10 mol% from a second thickness range of about 0 micrometers to about 25 micrometers. The glass-based article may include an optional third metal oxide.

[0017] In one or more embodiments, the glass-based articles described herein can exhibit a surface compressive stress (CS) greater than the maximum CT. One or more embodiments of the glass-based articles described herein can include a surface CS of about 300 MPa or greater. In some instances, this surface CS is exhibited when the glass-based article has a thickness of about 2 mm or less. In one or more embodiments, the glass-based article exhibits a combination of a surface CS of about 200 MPa or greater and a chemical depth of layer of about 0.4·t or greater. In one or more embodiments, the glass-based article has a CS extending from the first surface to a DOC, where the DOC is about 0.1·t or greater. In some instances, the ratio of the maximum CT to the absolute value of the surface CS ranges from about 0.1 to about 0.8.

[0018] In one or more embodiments, the glass-based article has an amorphous structure. In some embodiments, the glass-based article may have a crystalline structure.

[0019] In one or more embodiments, the glass-based articles described herein can exhibit a transmittance of about 88% or greater over a wavelength range of about 380 nm to about 780 nm. In some examples, the glass-based articles described herein can exhibit CIELAB color space coordinates under CIE illuminant F02 with an L* value of about 88° or greater, an a* value within the range of about -3° to about +3°, and a b* value within the range of about -6° to about +6°. In one or more embodiments, the glass-based articles described herein can have a Young's modulus of about 70 GPa or greater. In some embodiments, the glass-based articles described herein have a liquid viscosity of less than about 100 kilopoise (kP). In one or more embodiments, the glass-based articles described herein have a liquid viscosity of about 0.65 MPa m 1 / 2In one or more embodiments, the glass-based articles described herein include any one or more of compositions comprising a combined amount of about 15 mol% or less Al2O3 and Na2O, compositions comprising about 4 mol% or more Na2O, compositions comprising any one or more of B2O3 and ZnO, and compositions that are substantially free of P2O5. In one or more embodiments, the glass-based articles exhibit a fracture toughness (K1C) of about 450 μm at about 460° C. 2 / hr (square micrometers per hour) or greater. In some embodiments, this monovalent ion diffusivity is exhibited in combination with a DOC greater than about 0.15 t and a surface CS that is 1.5 times or greater than the maximum CT.

[0020] In one or more embodiments, the glass-based articles described herein exhibit certain fracture behavior. For example, in one or more embodiments, when a sample is broken using a 5.08 cm x 5.08 cm (2 inch x 2 inch) square sample size and the glass-based article is broken by a single event (i.e., a single impact such as dropping or a single impact with an instrument), the glass-based article breaks into at least two fragments per square inch (fragments per square inch). The number of fragments is divided by the area (in square inches) of the sample being tested. In some embodiments, when the glass-based article is broken, the sample is broken into at least one fragment per square inch (fragments per square inch) and up to 40 fragments per square inch (fragments per square inch).

[0021] A seventh aspect of the present disclosure relates to the use of a glass substrate in a strengthened glass-based article. In one or more embodiments, the glass substrate comprises (in mole %): SiO in an amount ranging from about 68 to about 75, AlO in an amount ranging from about 12 to about 15, BO in an amount ranging from about 0.5 to about 5, LiO in an amount ranging from about 2 to about 10, NaO in an amount ranging from about 0 to about 6, MgO in an amount ranging from about 1 to about 4, ZnO in an amount ranging from about 0 to about 3, and CaO in an amount ranging from about 0 to about 5, and the glass substrate is ion-exchangeable and amorphous. In one or more embodiments, the glass substrate exhibits any one or more of: a ratio of Li2O to RO in the range of about 0.45 to about 1; a difference between the total amount of RO and the amount of Al2O3 in the range of about -5 to about 0; a difference between the total amount (mol %) of RxO and the amount of Al2O3 in the range of about 0 to about 3; and a ratio of the amount (mol %) of MgO to the total amount (mol %) of RO in the range of about 0 to about 1, wherein the glass substrate is substantially free of a nucleating agent.

[0022] An eighth aspect of the present disclosure relates to a glass substrate comprising a composition including, in mole percent, SiO in an amount ranging from about 68 to about 75, AlO in an amount ranging from about 12 to about 15, BO in an amount ranging from about 0.5 to about 5, LiO in an amount ranging from about 2 to about 10, NaO in an amount ranging from about 0 to about 6, MgO in an amount ranging from about 1 to about 4, ZnO in an amount ranging from about 0 to about 3, and CaO in an amount ranging from about 0 to about 5, wherein the glass substrate is ion-exchangeable and amorphous. In one or more embodiments, the glass substrate exhibits any one or more of the following: a ratio of LiO to RO in a range of from about 0.45 to about 1; a difference between the total amount of RO and the amount of AlO in a range of from about -5 to about 0; a difference between the total amount of RO (mol%) and the amount of AlO in a range of from about 0 to about 3; and a ratio of the amount of MgO (mol%) to the total amount of RO (mol%) in a range of from about 0 to about 1. In one or more embodiments, the glass substrate is substantially free of nucleating agents. A ninth aspect of the present disclosure relates to a glass substrate comprising, in mole percent, SiO in an amount ranging from about 68 to about 75, AlO in an amount ranging from about 12 to about 15, BO in an amount ranging from about 0.5 to about 5, LiO in an amount ranging from about 2 to about 10, NaO in an amount ranging from about 0 to about 6, MgO in an amount ranging from about 1 to about 4, ZnO in an amount ranging from about 0 to about 3, and CaO in an amount ranging from about 0 to about 5, wherein the glass substrate is amorphous and tempered. In one or more embodiments, the NaO concentration varies within the glass substrate. In one or more embodiments, the glass substrate is substantially free of a nucleating agent. According to one or more embodiments, the strengthened glass substrate exhibits any one or more of the following compositional relationships: a ratio of LiO to R2O in the range of about 0.45 to about 1; a difference between the total amount of R2O and the amount of Al2O3 in the range of about -5 to about 0; a difference between the total amount (mol %) of RxO and the amount of Al2O3 in the range of about 0 to about 3; and a ratio of the amount (mol %) of MgO to the total amount (mol %) of RO in the range of about 0 to about 1.

[0023] A tenth aspect of the present disclosure is a housing having a front surface, a back surface, and a side surface; an electrical component at least partially inside the housing; a display at or near the front surface of the housing; a cover substrate disposed over the display, the cover substrate comprising a glass-based article according to an embodiment described herein.

[0024] Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description, or will be recognized by practicing the embodiments described herein, including the following detailed description, claims, and accompanying drawings.

[0025] It is to be understood that the foregoing general description and the following detailed description are merely exemplary and are intended to provide an overview or framework for understanding the nature and characteristics of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s) and, together with the description, serve to explain the principles and operation of the various embodiments. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a cross-section through the thickness of a known thermally tempered glass article. [Figure 2] FIG. 2 is a cross-sectional view across the thickness of a known chemically strengthened glass article. [Figure 3] FIG. 3 is a cross-sectional view across the thickness of a chemically strengthened glass-based article according to one or more embodiments of the present disclosure. [Figure 4] FIG. 4 is a graph illustrating various stress profiles according to one or more embodiments of the present disclosure. [Figure 5] FIG. 5 is a schematic cross-sectional view of a ring-on-ring device. [Figure 6] FIG. 6 is a schematic cross-sectional view of one embodiment of an apparatus used to conduct the inverted ball-on-sandpaper (IBoS) test described in this disclosure. [Figure 7] FIG. 7 is a schematic cross-sectional view illustrating the main mechanisms of damage introduction and bending failure that typically occur in glass-based articles used in portable or handheld electronic devices. [Figure 8] FIG. 8 is a flow chart of a method for performing an IBoS test in an apparatus described herein. [Figure 9] FIG. 9 is a graph illustrating the concentration of Na2O in known chemically strengthened glass-based articles and glass-based articles according to one or more embodiments of the present disclosure. [Figure 10]FIG. 10 is a graph showing CT and DOC values ​​as a function of ion exchange time, according to one or more embodiments of the present disclosure. [Figure 11] FIG. 11 is a graph comparing the stress profile as a function of depth of a known chemically strengthened glass-based article and a glass-based article according to one or more embodiments of the present disclosure. [Figure 12] FIG. 12 shows a graph of the stress profile of known chemically strengthened glasses and glass-ceramics. [Figure 13] FIG. 13 shows a graph of the stress profile of glasses and glass-ceramics according to one or more embodiments of the present disclosure. [Figure 13A] FIG. 13A shows a graph of defect height in the drop test for Example 3D. [Figure 14] FIG. 14 is a graph comparing known stress profiles of a chemically strengthened glass-based article and a glass-based article according to one or more embodiments of the present disclosure. [Figure 15] FIG. 15 is a graph showing the stress profile as a function of thickness for Examples 4A-4D. [Figure 16] FIG. 16 is a graph showing the discrete stored tensile energy data points for Examples 4B-4D. [Figure 17] FIG. 17 is a graph showing the concentrations of K2O and Na2O as a function of depth for Examples 4A-4D. [Figure 18] FIG. 18 is a graph showing the same data as FIG. 16, but with a different scale to more clearly show the concentration of Na2O as a function of depth. [Figure 19] FIG. 19 is a graph showing the stress profile as a function of depth for Examples 4A and 4C-4F. [Figure 20] FIG. 20 is a graph showing different scales of FIG. [Figure 21] FIG. 21 is a graph showing the stress profile as a function of depth for Examples 5A-5G. [Figure 22] FIG. 22 is a graph showing the DOC values ​​for Examples 5A-5G as a function of the duration of the second and / or third ion exchange steps. [Figure 23] FIG. 23 is a graph showing the C T values ​​for Examples 5A-5G as a function of the duration of the second and / or third ion exchange steps. [Figure 24] FIG. 24 is a graph showing CT as a function of ion exchange time for Examples 6A-6G. [Figure 25] FIG. 25 is a graph showing the change in center tension and stored tensile energy as a function of ion exchange time for all Examples 6A to 6G. [Figure 26] FIG. 26 is a graph showing the stress profile as a function of depth for Comparative Example 7A and Example 7B. [Figure 27] FIG. 27 is a graph showing the stored tensile energy as a function of CT for Comparative Example 7A and Example 7B. [Figure 28] FIG. 28 is a graph showing the stored tensile energy as a function of CT for Comparative Example 7C and Example 7D. [Figure 29] FIG. 29 is a graph showing drop height defects for Examples 2 and 8 and Comparative Examples 8A and 8B. [Figure 30] FIG. 30 is a graph showing wear ring-on-ring results for Examples 2 and 8 and Comparative Examples 8B and 8C. [Figure 31] FIG. 31 is a Weibull distribution diagram showing the four-point bending results for Examples 2 and 8B. [Figure 32] FIG. 32 is a graph showing the maximum CT values ​​for Examples 9A-9E as a function of ion exchange time. [Figure 33] FIG. 33 is a graph showing the measured stress of Example 9D as a function of depth extending into the glass-based article from the surface of the glass-based article of Example 9D. [Figure 34]FIG. 34 is a graph showing load to failure values ​​for glass-based articles according to Example 10A after being abraded at different loads or pressures. [Figure 35] FIG. 35 is a graph showing the height at which a glass-based article according to Example 10A failed after being dropped onto 180-grit sandpaper and then onto 30-grit sandpaper. [Figure 36] FIG. 36 is a graph showing the height at which glass-based articles according to Example 10A and Comparative Example 10B failed after being dropped onto 30-grit sandpaper. [Figure 37] FIG. 37 is a graph comparing the average load to failure for glass-based articles according to Example 10A and Comparative Example 10B after being abraded at a load or pressure of 25 psi. [Figure 38] FIG. 38 is a graph comparing the average load to failure for glass-based articles according to Example 10A and Comparative Example 10B after being abraded at a load or pressure of 45 psi. [Figure 39] FIG. 39 is a front plan view of an electronic device incorporating one or more embodiments of the glass-based articles described herein. [Figure 40] FIG. 40 is a graph showing IBoS test results for samples according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0027] Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying examples and drawings.

[0028] In the following description, like reference numerals designate like or corresponding parts throughout the several views shown in the drawings. It is also understood that, unless otherwise specified, terms such as "top," "bottom," "outward," and "inward" are words of convenience and should not be construed as limiting terms. Furthermore, whenever a group is described as including at least one of a group of elements and combinations thereof, the group can include, consist essentially of, or consist of any number of those listed elements, individually or in combination with each other. Similarly, whenever a group is described as consisting of at least one of a group of elements or combinations thereof, it is understood that the group can be composed of any number of the listed elements, individually or in combination with each other. Unless otherwise specified, when listed, a range of values ​​includes both the upper and lower limits of the range, as well as any ranges therebetween. As used herein, unless otherwise specified, nouns refer to the object "at least one" or "one or more." It is also understood that the various features disclosed in this specification and the drawings can be used in any and all combinations.

[0029] As used herein, the terms "glass-based article" and "glass-based substrate" are used in their broadest sense to include any object composed entirely or partially of glass. Glass-based articles include laminates of glass and non-glass materials, laminates of glass and crystalline materials, and glass-ceramics (including amorphous and crystalline phases). Unless otherwise specified, all compositions are expressed in mole percent (mol%).

[0030] It should be noted that the terms "substantially" and "about" may be utilized herein to express the inherent degree of uncertainty that may result from any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to express the extent to which a quantitative representation may vary from the stated reference without resulting in a change in the basic functionality of the subject matter in question.

[0031] As used herein, the term "about" means that amounts, dimensions, compositions, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or dimensional, possibly subject to tolerances, conversion factors, rounding, measurement error, and other factors known to those skilled in the art. When the term "about" is used in describing a value or an endpoint of a range, the disclosure should be understood to include the specific value or endpoint referred to. Regardless of whether the numerical value or endpoint of a range in the specification implies "about," the numerical value or endpoint of the range is intended to include two embodiments: those modified by "about" and those not modified by "about." It will be further understood that the endpoints of each range are significant both in relation to the other endpoint and independently of the other endpoint.

[0032] Unless otherwise specified, all temperatures are expressed in degrees Celsius (°C). As used herein, the term "softening point" refers to the temperature at which the viscosity of a glass is about 107.6 poise (P), the term "annealing point" refers to the temperature at which the viscosity of a glass is about 1013.2 poise, the term "200 poise temperature (T200P)" refers to the temperature at which the viscosity of a glass is about 200 poise, the term "1011 poise temperature" refers to the temperature at which the viscosity of a glass is about 1011 poise, the term "35 kP temperature (T35kP)" refers to the temperature at which the viscosity of a glass is about 35 kilopoise (kP), and the term "160 kP temperature (T160kP)" refers to the temperature at which the viscosity of a glass is about 160 kP.

[0033] Referring generally to the drawings, and particularly to Figures 1-3, it will be understood that the figures are for purposes of illustrating particular embodiments and are not intended to limit the scope of the disclosure or the appended claims. The drawings are not necessarily to scale, and certain features and views of the drawings may be shown exaggerated or schematic in the interest of clarity and conciseness.

[0034] As used herein, DOC refers to the depth within a glass-based article where stress changes from compressive to tensile. At the DOC, the stress crosses from positive (compressive) to negative (tensile) stress (e.g., 130 in Figure 1), thus indicating a stress value of zero.

[0035] As used herein, the terms "chemical depth," "chemical depth of layer," and "chemical layer depth" can be used interchangeably and refer to the depth to which metal oxide or alkali metal oxide ions (e.g., metal ions or alkali metal ions) diffuse into a glass-based article and the depth at which the concentration of the ions reaches a minimum, as determined by electron probe microanalysis (EPMA) or glow discharge-optical emission spectroscopy (GD-OES). In particular, measurements can be made using EPMA and a surface stress meter (described in more detail below) to assess the depth of diffusion of NaO or Na+ ion concentration.

[0036] According to common practice in the art, compression is expressed as a negative (<0) stress and tension as a positive (>0) stress unless otherwise specified. However, throughout this specification, references to compressive stress Cs refer to either a positive or negative value, i.e., Cs = |Cs|, as described herein.

[0037] Described herein are thin, chemically strengthened glass-based articles, including glasses and glass-ceramics, such as silicate glasses, including alkali-containing glasses, that can be used as cover glasses for portable electronic devices and touch-enabled displays. The glass-based articles can also be used in displays (or display articles) (e.g., signs, point-of-sale systems, computers, navigation systems, etc.), architectural articles (walls, fixtures, panels, windows, etc.), transportation articles (e.g., automotive applications, trains, aircraft, ships, etc.), appliances (e.g., washers, dryers, dishwashers, refrigerators, etc.), or any article requiring some degree of fracture resistance. In particular, the glass-based articles described herein are thin, but typically exhibit stress profiles achievable only by tempering thicker glass articles (e.g., having thicknesses of about 2 mm or 3 mm or more). Glass-based articles exhibit unique stress profiles along their thickness. In some cases, the glass-based articles described herein exhibit greater surface CS than tempered glass articles. In one or more embodiments, the glass-based articles have a compressive stress layer that extends deep within the glass-based article (where CS decreases and increases more slowly than known chemically strengthened lath-based articles), thereby providing the glass-based article with substantially improved fracture resistance, even when the glass-based article or a device comprising the same is dropped onto a hard surface (e.g., granite) or a hard, rough surface (e.g., asphalt). The glass-based articles of one or more embodiments exhibit greater maximum CT values ​​than some known chemically strengthened glass substrates.

[0038] The penetration depth of CS and potassium ions ("potassium DOL") is measured using means known in the art. The potassium DOL is distinct from the DOC because it represents the depth of potassium penetration as a result of the ion exchange process. The potassium DOL is generally less than the DOC for the articles described herein. CS and potassium DOL are measured by a surface stress meter (FSM) using commercially available equipment, such as the FSM-6000 manufactured by Orihara Industries Co., Ltd. (Japan). Surface stress measurement relies on accurate measurement of the stress-optical coefficient (SOC), which is related to the birefringence of the glass. The SOC is then measured according to a modified version of Procedure C described in ASTM Standard C770-98 (2013), entitled "Standard Test Method for Measurement of the Stress-Optical Coefficient of Glass," the contents of which are incorporated herein by reference in their entirety. This modification involves using a glass disk as the test specimen, 5-10 mm thick and 12.7 mm in diameter, which is isotropic and homogeneous, with a hole drilled in the center and abraded and parallel surfaces. The correction also involves calculating the maximum force, Fmax, to be applied. This force must be large enough to generate a compressive stress of at least 20 MPa. Fmax is calculated as follows:

[0039] Fmax=7.854*D*h During the ceremony Fmax = force in Newtons D = disc diameter h = optical path thickness For each applied force, the stress is calculated as follows:

[0040] σMPa=8F / (π*D*h) During the ceremony F = force in newtons D = disc diameter h = optical path thickness.

[0041] The DOC and maximum CT value are measured using a scattered light polarizer (SCALP) technique known in the art. The refractive near-field (RNF) method or SCALP can be used to measure the stress profile. When the RNF method is used, the maximum CT value provided by SCALP is utilized. In particular, the stress profile measured by RNF is force balanced and calibrated to the maximum CT value provided by the SCALP measurement. The RNF method is described in U.S. Pat. No. 8,854,623, entitled "System and Method for Measuring Profile Properties of Glass Samples," which is incorporated herein by reference in its entirety. Specifically, the RNF method involves placing a glass-based article adjacent to a reference block, generating a polarization-switched light beam that switches between orthogonal polarizations at a rate between 1 Hz and 50 Hz, measuring the amount of force in the polarization-switched light beam, and generating a polarization-switched reference signal, wherein the measured amounts of force at each of the orthogonal polarizations are within 50% of each other. The method further includes transmitting a polarization-switched light beam through the glass sample and the reference block to different depths in the glass sample, then relaying the transmitted polarization-switched light beam to a signal light detector using a relay optical system, which generates a polarization-switched detector signal. The method also includes dividing the detector signal by the reference signal to form a normalized detector signal and determining profile characteristics of the glass sample from the normalized detector signal. The RNF profile is then smoothed and used in the CT region. As described above, the FSM technique is used to characterize the slope of the stress profile in the surface CS and near-surface CS regions.

[0042] As noted above, the glass-based articles described herein are chemically strengthened by ion exchange and exhibit stress profiles distinct from those exhibited by known strengthened glass articles. In this disclosure, glass-based substrates are typically not strengthened, and glass-based articles generally refer to glass-based substrates that have been strengthened (e.g., by ion exchange). In this process, ions at or near the surface of the glass-based article are replaced or exchanged with larger ions having the same valence or oxidation state. In embodiments where the glass-based article comprises an alkali aluminosilicate glass, the ions in the surface layer of the glass and the larger ions are monovalent alkali metal cations, such as Li+ (if present in the glass-based article), Na+, K+, Rb+, and Cs+. Alternatively, the monovalent cations in the surface layer may be replaced with monovalent cations other than alkali metal cations, such as Ag+. In such embodiments, the monovalent ions (or cations) exchanged into the glass-based substrate generate stress in the resulting glass-based article.

[0043] The ion exchange process is typically carried out by immersing the glass-based substrate in a molten salt bath (or two or more molten salt baths) containing larger ions to be exchanged for smaller ions in the glass-based substrate. It should be noted that aqueous salt baths can also be used. Furthermore, the bath composition can include two or more types of larger ions (e.g., Na+ and K+) or a single larger ion. Those skilled in the art will appreciate that the parameters of the ion exchange process, including but not limited to the bath composition and temperature, immersion time, number of immersions of the glass-based article in the salt bath(s), use of multiple salt baths, and additional steps such as annealing and washing, are generally determined by the composition of the glass-based article (including the structure of the article and any crystalline phases present) and the desired DOC and CS of the glass-based article resulting from strengthening. By way of example, ion exchange of a glass-based substrate can be achieved by immersing the glass-based substrate in at least one molten salt bath containing salts of larger alkali metal ions, such as, but not limited to, nitrates, sulfates, and chlorides. Typical nitrates include KNO3, NaNO3, LiNO3, NaSO4, and combinations thereof. The temperature of the molten salt bath typically ranges from about 380°C to about 450°C, and the immersion time ranges from about 15 minutes to about 100 hours, depending on the glass thickness, bath temperature, and glass (or monovalent ion) diffusivity. However, temperatures and immersion times other than those stated above can also be used.

[0044] In one or more embodiments, the glass-based substrate may be immersed in a molten salt bath of 100% NaNO having a temperature of about 370°C to about 480°C. In some embodiments, the glass-based substrate may be immersed in a molten mixed salt bath containing about 5% to about 90% KNO and about 10% to about 95% NaNO. In some embodiments, the glass-based substrate may be immersed in a molten mixed salt bath containing NaSO and NaNO having a wider temperature range (e.g., up to about 500°C). In one or more embodiments, the glass-based article may be immersed in a second bath after immersion in the first bath. Immersion in the second bath may include immersion in a molten salt bath containing 100% KNO for 15 minutes to 8 hours.

[0045] In one or more embodiments, the glass-based substrate can be immersed in a molten mixed salt bath containing NaNO and KNO (e.g., 49% / 51%, 50% / 50%, 51% / 49%) having a temperature of less than about 420° C. (e.g., about 400° C. or about 380° C.) for less than about 5 hours, or for up to about 4 hours.

[0046] The ion exchange conditions can be tailored to create a "spike" or increase the slope of the stress profile at or near the surface of the resulting glass-based article. This spike can be achieved by a single bath or multiple baths having a single or mixed composition due to the unique properties of the glass compositions used in the glass-based articles described herein.

[0047] As shown in FIG. 3, the glass-based article 300 of one or more embodiments includes a first surface 302 and a second surface 304 opposite the first surface, which define a thickness t. In one or more embodiments, the thickness t can be about 3 millimeters or less (e.g., in a range of about 0.01 millimeters to about 3 millimeters, about 0.1 millimeters to about 3 millimeters, about 0.2 millimeters to about 3 millimeters, about 0.3 millimeters to about 3 millimeters, about 0.4 millimeters to about 3 millimeters, about 0.01 millimeters to about 2.5 millimeters, about 0.01 millimeters to about 2 millimeters, about 0.01 millimeters to about 1.5 millimeters, about 0.01 millimeters to about 1 millimeter, about 0.01 millimeters to about 0.9 millimeters, about 0.01 millimeters to about 0.8 millimeters, about 0.01 millimeters to about 0.7 millimeters, about 0.01 millimeters to about 0.6 millimeters, about 0.01 millimeters to about 0.5 millimeters, about 0.1 millimeters to about 0.5 millimeters, or about 0.3 millimeters to about 0.5 millimeters).

[0048] The glass-based article includes a stress profile that extends from the first surface 302 to the second surface 304 (or along the entire thickness t). In the embodiment shown in Figure 3, stress profile 312. The y-axis represents stress values ​​and the x-axis represents the thickness or depth of the glass-based article.

[0049] 3, the stress profile 312 includes a CS layer 315 (with a surface CS 310), a CT layer 325 (with a maximum CT 320), and a DOC 330, where the stress profile 312 changes from compressive to tensile. The CS layer has an associated depth or length 317 that extends from the surfaces 302, 304 to the DOC 330. The CT layer 325 also has an associated depth or length 327 (CT region or layer).

[0050] Surface CS 310 can be about 150 MPa or greater or about 200 MPa or greater (e.g., about 250 MPa or greater, about 300 MPa or greater, about 400 MPa or greater, about 450 MPa or greater, about 500 MPa or greater, or about 550 MPa or greater). Surface CS 310 can be up to about 900 MPa, up to about 1000 MPa, up to about 1100 MPa, or up to about 1200 MPa. Surface CS values ​​herein can also include maximum CS. In some embodiments, surface CS is less than maximum CS.

[0051] The maximum CT320 may be about 71.5 / √(t) or greater. In some embodiments, the maximum CT320 is about 80 MPa or greater, about 85 MPa or greater, or about 90 MPa or greater. In some embodiments, the maximum CT320 may be in a range of greater than about 80 MPa to about 100 MPa (e.g., about 85 MPa to about 100 MPa, about 90 MPa to about 100 MPa, about 80 MPa to about 95 MPa, about 80 MPa to about 90 MPa, about 85 MPa to about 95 MPa, or about 88 MPa to about 92 MPa). The maximum CT320 may be located in a range of about 0.3·t to about 0.7·t, about 0.4·t to about 0.6·t, or about 0.45·t to about 0.55·t. It should be noted that any one or more of the surface CS310 and the maximum CT320 may depend on the thickness of the glass-based article. For example, a glass-based article having a thickness of about 0.8 mm may have a maximum CT in the range of about 85 MPa to about 100 MPa. As the thickness of the glass-based article decreases, the maximum CT value may increase. In other words, as the thickness decreases (or the glass-based article becomes thinner), the maximum CT value increases.

[0052] In some embodiments, the ratio of maximum CT320 to surface CS310 is within a range of about 0.1 to about 0.8 (e.g., within a range of about 0.1 to about 0.7, about 0.1 to about 0.6, about 0.1 to about 0.5, about 0.1 to about 0.4, about 0.1 to about 0.3, about 0.1 to about 0.25, about 0.1 to about 0.2, about 0.15 to about 0.8, about 0.2 to about 0.8, about 0.3 to about 0.8, about 0.4 to about 0.8, about 0.5 to about 0.8, or about 0.6 to about 0.8). In known chemically strengthened glass-based articles, the ratio of maximum CT320 to surface CS310 is 0.1 or less. In some embodiments, the surface CS can be 4 times (e.g., 5 times, 6 times, or 6.5 times) or more the maximum CT. In some embodiments, the surface CS can be up to about 47.5 times the maximum CT. The surface CS may be in the range of about 4 to about 7.5 times the maximum CT.

[0053] In one or more embodiments, stress profile 312 includes a maximum CS, which is typically a surface CS 310 and can be found at one or both of first surface 302 and second surface 304. In one or more embodiments, CS layer or region 315 extends along a portion of thickness 317 to DOC 330 and maximum CT 320. In one or more embodiments, DOC 330 can be about 0.1·t or greater. For example, DOC 330 can be about 0.12·t or greater, about 0.14·t or greater, about 0.15·t or greater, about 0.16·t or greater, 0.17·t or greater, 0.18·t or greater, 0.19·t or greater, 0.20·t or greater, about 0.21·t or greater, or up to about 0.25·t. In some embodiments, DOC 330 is less than the chemical depth. The chemical depth may be about 0.4·t or greater, 0.5·t or greater, about 0.55·t or greater, or about 0.6·t or greater.

[0054] In one or more embodiments, the glass-based article has a potassium DOL in the range of about 6 micrometers to about 20 micrometers. In some embodiments, the potassium DOL can be expressed as a function of the thickness, t, of the glass-based article. In one or more embodiments, the potassium DOL can be in the range of about 0.005·t to about 0.05·t. In some embodiments, the potassium DOL can be in the range of about 0.005·t to about 0.05·t, about 0.005·t to about 0.045·t, about 0.005·t to about 0.04·t, about 0.005·t to about 0.035·t, about 0.005·t to about 0.03·t, about 0.005·t to about 0.025·t, about 0.005·t to about 0.02·t, about 0.005·t to about 0.015·t, It may be in the range of about 0.005·t to about 0.01·t, about 0.006·t to about 0.05·t, about 0.008·t to about 0.05·t, about 0.01·t to about 0.05·t, about 0.015·t to about 0.05·t, about 0.02·t to about 0.05·t, about 0.025·t to about 0.05·t, about 0.03·t to about 0.05·t, or about 0.01·t to about 0.02·t.

[0055] In one or more embodiments, the compressive stress value at the potassium DOL depth may be in the range of about 50 MPa to about 300 MPa. In some embodiments, the compressive stress value at the potassium DOL depth may be in the range of about 50 MPa to about 280 MPa, about 50 MPa to about 260 MPa, about 50 MPa to about 250 MPa, about 50 MPa to about 240 MPa, about 50 MPa to about 220 MPa, about 50 MPa to about 200 MPa, about 60 MPa to about 300 MPa, about 70 MPa to about 300 MPa, about 75 MPa to about 300 MPa, about 80 MPa to about 300 MPa, about 90 MPa to about 300 MPa, about 100 MPa to about 300 MPa, about 110 MPa to about 300 MPa, about 120 MPa to about 300 MPa, about 130 MPa to about 300 MPa, or about 150 MPa to about 300 MPa.

[0056] In one or more embodiments, stress profile 312 can be described as parabolic in shape. In some embodiments, the stress profile along a region or depth of the glass-based article exhibiting tensile stress exhibits a parabolic shape. In one or more specific embodiments, stress profile 312 does not include a portion exhibiting a flat stress (either compressive or tensile) or a portion exhibiting a substantially constant stress (either compressive or tensile). In some embodiments, the CT region exhibits a stress profile that is substantially free of flat stress or substantially constant stress. In one or more embodiments, all points of stress profile 312 between the thickness ranges of about 0·t to about 0.2·t and greater than 0.8·t (or about 0·t to about 0.3·t and about 0.7·t to t) include a tangent with a slope of an absolute value greater than about 0.1 MPa / micrometer. In some embodiments, the slope of the tangent can have an absolute value greater than about 0.2 MPa / micrometer. In some more specific embodiments, the slope of the tangent can have an absolute value greater than about 0.3 MPa / micrometer. In even more specific embodiments, the slope of the tangent can have an absolute value greater than about 0.5 MPa / micrometer. In other words, the stress profiles of one or more embodiments along these thickness ranges (i.e., from 0·t to about 0.2·t and greater than 0.8·t, or from 0·t to about 0.3·t and greater than about 0.7·t) exclude points having a tangent with a zero slope, a near-zero slope, or a flat slope. Without being bound by theory, known error functions or quasi-linear stress profiles have points along these thickness ranges (i.e., from 0·t to about 0.2·t and greater than 0.8·t, or from 0·t to about 0.3·t and greater than about 0.7·t) that have a tangent with a slope of zero or near-zero, i.e., an absolute value less than about 0.1 MPa / micrometer (as shown in FIG. 2, 220, which shows a flat or zero-slope stress profile along such a thickness range).The glass-based articles of one or more embodiments of the present disclosure do not exhibit a stress profile with a flat or zero-gradient stress profile along these thickness ranges, as shown in FIG.

[0057] In one or more embodiments, the glass-based article exhibits a stress profile within thickness ranges of about 0.1·t to 0.3·t and about 0.7·t to 0.9·t, including tangents with maximum and minimum slopes. In some cases, the difference between the maximum and minimum slopes is about 3.5 MPa / micrometer or less, about 3 MPa / micrometer or less, about 2.5 MPa / micrometer or less, or about 2 MPa / micrometer or less.

[0058] In one or more embodiments, the glass-based article comprises a stress profile 312 that is substantially free of any flat portions extending across the depth or along at least a portion of the thickness t of the glass-based article. In other words, the stress profile 312 increases or decreases substantially continuously along the thickness t. In some embodiments, the stress profile is substantially free of any flat portions in the depth direction having a length of about 10 micrometers or more, about 50 micrometers or more, about 100 micrometers or more, or about 200 micrometers or more. As used herein, the term "flat" refers to a slope along a flat portion having a magnitude of less than about 0.5 MPa / micrometer, or less than about 0.2 MPa / micrometer. In some embodiments, one or more portions of the stress profile that are substantially free of any flat portions in the depth direction exist at a depth within the glass-based article of about 5 micrometers or more (e.g., 10 micrometers or more, or 15 micrometers or more) from one or both of the first surface or the second surface. For example, along a depth of about 0 micrometers to less than about 5 micrometers from the first surface, the stress profile may include a linear portion, but from a depth of about 5 micrometers or more from the first surface, the stress profile may not include a substantially flat portion. As used herein, "linear" includes line segments with a flat slope and line segments without a flat slope, see, for example, Figure 33 within a depth of about 12 micrometers from the surface.

[0059] In some embodiments, the stress profile may include a linear portion from a depth of about 0·t to about 0.1·t and may be substantially free of a flat portion from a depth of about 0.1·t to about 0.4·t. In some embodiments, the stress profile for a thickness in the range of about 0·t to about 0.1·t may have a slope with a magnitude (absolute value) in the range of about 20 MPa / micrometer to about 200 MPa / micrometer. As described herein, such embodiments may be formed using a single ion exchange process, or multiple (e.g., two or more) ion exchange processes, where the bath includes two or more alkali salts or is a mixed alkali salt bath.

[0060] In one or more embodiments, the glass-based article can be described in terms of the stress profile along the CT region (327 in Figure 3). For example, in some embodiments, the stress profile along the CT region (where the stress is tensile) can be approximated by the equation: In some embodiments, the stress profile along the CT region can be approximated by equation (1): Stress(x)=MaxT-(((CTn·(n+1)) / 0.5n)·|(x / t)-0.5|n) (1) In Equation (1), Stress(x) is the stress value at location x, where Stress is positive (tension). In Equation (1), MaxT is the maximum tension value, and CTn is the tension value at n, which is less than or equal to MaxT. Both MaxT and CTn are positive values ​​in MPa. The value x is a position along the thickness (t) in micrometers, ranging from 0 to t, where x=0 is on one side (302 in FIG. 3), x=0.5t is the center of the glass-based article (at which location Stress(x)=MaxT), and x=t is on the opposite side (304 in FIG. 3). MaxT, as used in Equation (1), is equivalent to the maximum CT, which may be greater than or equal to about 71.5 / √(t). In some embodiments, MaxT, as used in equation (1), can be in the range of greater than about 80 MPa to about 100 MPa (e.g., about 85 MPa to about 100 MPa, about 90 MPa to about 100 MPa, greater than about 80 MPa to about 95 MPa, greater than about 80 MPa to about 90 MPa, or about 85 MPa to about 95 MPa), and n is a fitting parameter of 1.5 to 5 (e.g., 2 to 4, 2 to 3, or 1.8 to 2.2), or about 1.5 to about 2. In one or more embodiments, n=2 can provide a parabolic stress profile, and the exponent resulting from n=2 provides a stress profile that approximates a parabolic stress profile. FIG. 4 is a graph illustrating various stress profiles according to one or more embodiments of the present disclosure based on variations in the fitting parameter n.

[0061] In one or more embodiments, CTn may be less than MaxT, in which case compressive stress spikes are present on one or both major surfaces of the glass-based article. In one or more embodiments, CTn is equal to MaxT, in which case compressive stress spikes are not present on one or both major surfaces of the glass-based article.

[0062] In some embodiments, the stress profile may be modified by heat treatment. In such embodiments, heat treatment may occur before any ion exchange process, during any ion exchange process, or after any ion exchange process. In some embodiments, heat treatment may reduce the absolute magnitude of the slope of the stress profile at or near the surface. In some embodiments where a steeper or larger slope is desired at the surface, an ion exchange process after heat treatment may be utilized to provide a "spike" or increase the slope of the stress profile at or near the surface.

[0063] In one or more embodiments, the stress profile 312 is generated due to a non-zero concentration of the metal oxide(s) varying along the thickness. As discussed above, the change in metal oxide concentration may be referred to herein as a metal oxide concentration gradient. In some embodiments, the concentration of the metal oxide is non-zero and varies along a thickness range of about 0·t to about 0.3·t. In some embodiments, the concentration of the metal oxide is non-zero and varies along a thickness range of about 0·t to about 0.35·t, about 0·t to about 0.4·t, about 0·t to about 0.45·t, or about 0·t to about 0.48·t. The metal oxide may be described as generating stress within the glass-based article. The change in concentration may be continuous along the thickness range described above. The change in concentration may include a change in metal oxide concentration of about 0.2 mol % along a thickness of about 100 micrometers. This change can be measured by methods known in the art, including a microprobe, as shown in Example 1. Metal oxides with non-zero concentrations that vary through the thickness can be described as generating stresses in the glass-based article.

[0064] The concentration change may be continuous along the thickness range described above. In some embodiments, the concentration change may be continuous along a thickness range of about 10 micrometers to about 30 micrometers. In some embodiments, the concentration of the metal oxide decreases from the first surface to a value at a point between the first surface and the second surface, and then increases from that value to the second surface.

[0065] The metal oxide concentration can include two or more metal oxides (e.g., a combination of Na2O and KO). In some embodiments where two metal oxides are used and the ions have different radii, the concentration of ions with larger radii is greater than the concentration of ions with smaller radii at shallower depths, while the concentration of ions with smaller radii is greater than the concentration of ions with larger radii at deeper depths. For example, if a single Na- and K-containing bath is used in an ion exchange process, the concentration of K+ ions in the glass-based article is greater than the concentration of Na+ ions at shallower depths, while the concentration of Na+ ions is greater than the concentration of K+ ions at deeper depths. This is due, in part, to the size of the monovalent ions that are exchanged into the glass for smaller monovalent ions. In such glass-based articles, regions at or near the surface will have a greater Cs due to a greater amount of larger ions (i.e., K+ ions) at or near the surface. This greater Cs can be indicated by a stress profile with a steeper slope at or near the surface (i.e., a spike in the stress profile at the surface).

[0066] The concentration gradient or variation of one or more metal oxides is created by chemically strengthening the glass-based substrate as described herein above to exchange a plurality of first metal ions in the glass-based substrate for a plurality of second metal ions. The first ions may be ions of lithium, sodium, potassium, and rubidium. The second metal ions may be ions of one of sodium, potassium, rubidium, and cesium, while the second alkali metal ions have an ionic radius larger than the ionic radius of the first alkali metal ions. The second metal ions are present in the glass-based substrate as their oxides (e.g., Na2O, KO, Rb2O, Cs2O, or combinations thereof).

[0067] In one or more embodiments, the metal oxide concentration gradient extends across a substantial portion of the thickness t or the entire thickness t of the glass-based article, including the CT layer 327. In one or more embodiments, the concentration of the metal oxide is about 0.5 mol % or greater in the CT layer 327. In some embodiments, the concentration of the metal oxide may be about 0.5 mol % or greater (e.g., about 1 mol % or greater) across the entire thickness of the glass-based article, being greatest at the first surface 302 and / or the second surface 304 and decreasing substantially at a constant rate to a value at a point between the first surface 302 and the second surface 304. At that point, the concentration of the metal oxide is lowest along the entire thickness t, but the concentration is also not zero at that point. In other words, a non-zero concentration of the particular metal oxide extends across a substantial portion of the thickness t (as described herein) or the entire thickness t. In some embodiments, the concentration of the particular metal oxide is lowest in the CT layer 327. The total concentration of the particular metal oxide in the glass-based article may range from about 1 mol % to about 20 mol %.

[0068] In one or more embodiments, the glass-based article includes a first metal oxide concentration and a second metal oxide concentration, where the first metal oxide concentration ranges from about 0 mol% to about 15 mol% along a first thickness range of about 0 t to about 0.5 t, and the second metal oxide concentration ranges from about 0 mol% to about 10 mol% along a second thickness range of about 0 micrometers to about 25 micrometers (or about 0 micrometers to about 12 micrometers), but the concentrations of one or both of the first metal oxide and the second metal oxide are non-zero along the entire thickness or a substantial portion of the glass-based article. The glass-based article can include an optional third metal oxide concentration. The first metal oxide can include NaO, and the second metal oxide can include KO.

[0069] The concentration of the metal oxide can be determined from the base amount of the metal oxide in the glass-based article before it is modified to have such a metal oxide concentration gradient.

[0070] In one or more embodiments, glass-based articles can be described in terms of how they break and the fragments resulting from such breakage, as measured by the "Fragility Test" described in Z. Tang et al., "Automated Apparatus for Measuring the Frangibility and Fragmentation of Strengthened Glass." Experimental Mechanics (2014) 54:903-912. In one or more embodiments, upon breakage, the glass-based article breaks into two or more fragments per square inch (or per 6.4516 square centimeters) of the glass-based article (before breakage). In some cases, the glass-based article breaks into three or more, four or more, five or more, or ten or more fragments per square inch (or per 6.4516 square centimeters) of the glass-based article (before breakage). In some examples, when broken, the glass-based article breaks into fragments such that 50% or more of the fragments have a surface area of ​​less than 5%, less than 2%, or less than 1% of the surface area of ​​the glass-based article (prior to breaking), and the sample dimensions used were 5.08 cm x 5.08 cm (2 inches x 2 inches) square. In some embodiments, when broken, the glass-based article breaks into fragments such that 90% or more or 100% of the fragments have a surface area of ​​less than 5%, less than 2%, or less than 1% of the surface area of ​​the glass-based article (prior to breaking).

[0071] In one or more embodiments, after chemically strengthening the glass-based article, the resulting stress profile 312 of the glass-based article provides improved fracture resistance. For example, in some embodiments, when broken, the glass-based article has fragments having an average longest cross-sectional dimension of about 2·t or less (e.g., 1.8·t, 1.6·t, 1.5·t, 1.4·t, 1.2·t, or 1·t or less), as measured by the "Fragility Test" described in Z. Tang et al., Automated Apparatus for Measuring the Frangibility and Fragmentation of Strengthened Glass. Experimental Mechanics (2014) 54:903-912. The number of fragments is divided by the area (in square inches) of the sample being tested, and the sample dimensions used were 5.08 cm x 5.08 cm (2 inches x 2 inches) square.

[0072] In one or more embodiments, the glass-based article has a modulus of about 0.65 MPa m 1 / 2 In some cases, fracture toughness is approximately 0.69 MPa m 1 / 2 Approximately 0.7MPa m 1 / 2 Approximately 0.8MPa m 1 / 2 or more or approximately 0.9 MPa m 1 / 2 In some embodiments, the fracture toughness may be about 0.65 MPa m 1 / 2 ~Approx. 1MPa m 1 / 2The fracture toughness values ​​(K1C) cited in this disclosure refer to values ​​measured by the chevron-notched short bar (CNSB) method disclosed in Reddy, KPR 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), where Y*m is calculated using Equation 5 in Bubsey, RT 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).

[0073] In some embodiments, the substrate has a hardness of about 500 HVN to about 800 HVN (kgf / mm) as measured by the Vickers hardness test under a load of 200 g. 2 In some embodiments, the glass-based article may include a Vickers hardness in the range of about 600 HVN to about 800 HVN.

[0074] The glass-based articles described herein have a thermal conductivity of 0 J / m 2 Super~about 40J / m 2 In some cases, the tensile energy reserve may be in the range of about 5 J / m 2 ~about 40J / m 2 , about 10J / m 2 ~about 40J / m 2 , about 15J / m 2 ~about 40J / m 2 , about 20J / m2 ~about 40J / m 2 , about 1J / m 2 ~About 35J / m 2 , about 1J / m 2 ~about 30J / m 2 , about 1J / m 2 ~about 25J / m 2 , about 1J / m 2 ~about 20J / m 2 , about 1J / m 2 ~about 15J / m 2 , about 1J / m 2 ~about 10J / m 2 , about 10J / m 2 ~about 30J / m 2 , about 10J / m 2 ~about 25J / m 2 , about 15J / m 2 ~about 30J / m 2 , about 15J / m 2 ~about 25J / m 2 , about 18J / m 2 ~About 22J / m 2 , about 25J / m 2 ~about 40J / m 2 or approximately 25 J / m 2 ~about 30J / m 2 The thermally and chemically strengthened glass-based article of one or more embodiments may have a thermal toughness in the range of about 6 J / m 2 Above, about 10J / m 2 Above, about 15J / m 2 or more or about 20 J / m 2 The above stored tensile energy can be shown.

[0075] The stored tensile energy can be calculated using equation (2) below:

[0076] Conserved tensile energy (J / m 2 )=[(1-ν) / E] ∫(σ^2)(dt) (2) where v is Poisson's ratio, E is Young's modulus (MPa), and σ is stress (MPa), and the integral is calculated over the thickness (micrometers) of the tensile region only. Each of the Young's modulus values ​​cited in this disclosure refers to values ​​measured by a resonant ultrasonic spectroscopy technique of the general type described in ASTM E2001-13, entitled "Standard Guide for Resonant Ultrasonic Spectroscopy for Defect Detection in Both Metallic and Non-Metallic Parts."

[0077] The glass-based articles described herein typically have a compressive strength of about 70 GPa or more (e.g., about 70 GPa to about 100 GPa, about 72 GPa to about 100 GPa, about 75 GPa to about 100 GPa, about 76 GPa to about 100 GPa, about 78 GPa to about 100 GPa, about 80 GPa to about 100 GPa, about 82 GPa to about 100 GPa, about 84 GPa to about 100 GPa, about 86 GPa to about 100 GPa). The Young's modulus of the glass-based article may be in the range of about 00 GPa, about 88 GPa to about 100 GPa, about 90 GPa to about 100 GPa, about 70 GPa to about 95 GPa, about 70 GPa to about 90 GPa, about 70 GPa to about 88 GPa, about 70 GPa to about 86 GPa, about 70 GPa to about 85 GPa, about 70 GPa to about 84 GPa, about 70 GPa to about 82 GPa, or about 70 GPa to about 80 GPa. The Young's modulus inherent in the composition of the glass-based article can provide a desired high stiffness, which is an extrinsic property, to the final glass-based article produced therefrom.

[0078] In some embodiments, the glass-based article comprises a low liquidus viscosity that enables the formation of the glass-based article via thin-rolling techniques. As used herein, the term "liquidus viscosity" refers to the viscosity of molten glass at its liquidus temperature, and the term "liquidus temperature" refers to the temperature at which crystals first appear as the molten glass cools from its melting temperature (or the temperature at which the last crystals melt as the temperature rises from room temperature). Generally, the glass-based articles described herein (or compositions used to form such articles) have a liquidus viscosity of less than about 100 kilopoise (kP). In some embodiments, the glass-based articles (or compositions used to form such articles) exhibit a liquidus viscosity of less than about 80 kP, less than about 60 kP, less than about 40 kP, or less than about 30 kP (e.g., in the range of about 15 kP to about 30 kP). The liquidus viscosity is determined in the following manner. First, the liquidus temperature of the glass is measured according to ASTM C829-81(2015), entitled "Standard Practice for Determining the Liquidus Temperature of Glass by the Gradient Furnace Method." The viscosity of the glass at the liquidus temperature is then measured according to ASTM C965-96(2012), entitled "Standard Practice for Measuring the Viscosity of Glass Above the Softening Point."

[0079] In one or more embodiments, the glass-based article exhibits a Knoop lateral crack scratch threshold in the range of about 4 N to about 7 N, about 4.5 N to about 7 N, about 5 N to about 7 N, about 4 N to about 6.5 N, about 4 N to about 6 N, or about 5 N to about 6 N. As used herein, the Knoop scratch lateral crack threshold is the initiation point of a lateral crack (at least three out of five scratches). A series of increasing constant load scratches (a minimum of three per load, but the number per load can be increased to increase the confidence level) is performed to determine the Knoop scratch threshold. For the Knoop scratch lateral crack threshold test, for each load, a sample of the glass substrate and / or article is scratched with a Knoop indenter over a length of 10 mm at a rate of 0.25 mm / s. The Knoop scratch threshold range can be determined by comparing specimens to one of the following three failure modes: 1) persistent side cracks greater than twice the width of the groove, 2) side cracks that contain damage within the groove but are less than twice the width of the groove and have damage visible to the naked eye, or 3) the presence of large subsurface transverse cracks greater than twice the width of the groove and / or a central crack at the highest level of the scratch. The scratch threshold is the highest load at which no failure occurs in three or more of the five conditions.

[0080] In one or more embodiments, the glass-based article exhibits a Vickers indentation fracture threshold in the range of about 10 kgf or more, about 12 kgf or more, or about 15 kgf or more. In some cases, the glass-based article exhibits a Vickers indentation fracture threshold in the range of about 15 kgf to about 25 kgf. As used herein, the Vickers indentation fracture threshold is the initiation point of a central / radial crack (in three or more of five indentation events) propagating from at least one corner of the indentation site. In the Vickers indentation fracture threshold test, glass substrate and article samples are repeatedly indented with a diamond tip (at a 136° angle) under increasing loads. Each indentation can generate four radial cracks, one from each corner of the indentation. By counting the average number of radial cracks at each indentation load, the crack threshold is the load at which there is an average of two cracks per indentation (or 50% crack threshold).

[0081] In one or more embodiments, glass-based articles exhibit improved surface strength when subjected to an abrasion ring-on-ring (AROR) test. The strength of a material is the stress at which fracture occurs. The AROR test is a surface strength measurement for testing flat glass specimens, and ASTM C1499-09(2013), entitled "Standard Test Method for Monotonic Equivalent Flexural Strength of Advanced Ceramics at Ambient Temperature," serves as the basis for the AROR test methodology described herein. The contents of ASTM C1499-09 are incorporated herein by reference in their entirety. In one embodiment, glass specimens are abraded prior to ring-on-ring testing using 90-grit silicon carbide (SiC) particles delivered to the glass sample using the method and apparatus described in Appendix A2, entitled "Abrasion Procedure," of ASTM C158-02(2012), entitled "Standard Test Method for Strength of Glass by Bending (Determination of Modulus of Rupture)." The contents of ASTM C158-02 and in particular the contents of Appendix 2 are incorporated herein by reference in their entirety.

[0082] Prior to ring-on-ring testing, the surface of the glass-based article is abraded as described in ASTM C158-02, Appendix 2, using the apparatus shown in Figure A2.1 of ASTM C158-02 to standardize and / or control the surface defect state of the sample. The abrasive is typically sandblasted onto the surface 110 of the glass-based article at a load of 15 psi using 304 kPa (44 psi) air pressure, although in the following examples, the abrasive was sandblasted onto the surface 110 at other loads (e.g., 25 psi or 45 psi). After the air flow was established, a 5 cm 3 of abrasive is dumped into the funnel and the sample is sandblasted for 5 seconds after the abrasive is introduced.

[0083] For AROR testing, a glass-based article having at least one wear surface 410, as shown in Figure 5, was placed between two concentric rings of different sizes, also shown in Figure 5, to determine the equivalent bending strength (i.e., the maximum stress the material can sustain when subjected to bending between two concentric rings). In the AROR configuration 400, the wear glass-based article 410 is supported by a support ring 420 having a diameter D2. A force F is applied by a load ring 430 of diameter D1 to the surface of the glass-based article by a load cell (not shown).

[0084] The ratio of the diameters of the load ring to the support ring, D1 / D2, can range from about 0.2 to about 0.5. In some embodiments, D1 / D2 is about 0.5. The load and support rings 130, 120 should be concentrically aligned to within 0.5% of the support ring diameter D2. The load cell used for testing should be accurate to within ±1% within the selected range at any load. In some embodiments, testing is performed at a temperature of 23±2°C and a relative humidity of 40±10%.

[0085] For fixture designs, the radius r of the protruding surface of the load ring 430 is h / 2≦r≦3h / 2, where h is the thickness of the glass-based article 410. The load and support rings 430, 420 are typically made of hardened steel with a hardness of HRc>40. AROR fixtures are commercially available.

[0086] The intended failure mechanism of the AROR test is to observe fracture of the glass-based article 410 beginning at surface 430a within the load ring 430. Failures occurring outside of this region, i.e., between the load ring 430 and the support ring 420, are excluded from data analysis. However, due to the thinness and high strength of the glass-based article 410, large deflections exceeding half the specimen thickness h can be observed. Therefore, it is not uncommon to observe a high percentage of failures originating from the underside of the load ring 430. Stress cannot be accurately calculated without knowing the stress evolution both inside and below the ring (collected by strain gauge analysis) and the origin of the defects in each specimen. Therefore, the AROR test focuses on the peak load at failure as the measured response.

[0087] The strength of glass-based articles depends on the presence of surface flaws. However, because the strength of glass is statistical in nature, the likelihood of a flaw of a given size cannot be accurately predicted. Therefore, in general, probability distributions can be used as statistical representations of the obtained data.

[0088] In some embodiments, the glass-based articles described herein have a surface or equivalent flexural strength of 20 kgf or greater, and up to about 30 kgf, as determined by the AROR test, which uses a load of 25 psi or 45 psi to abrade the surface. In other embodiments, the surface strength is 25 kgf or greater, and in still other embodiments, 30 kgf or greater.

[0089] In some embodiments, the glass-based articles described herein can be described in terms of their performance in an inverted ball-on-sandpaper (IBoS) test. The IBoS test, as shown schematically in FIG. 6, is a dynamic, component-level test that mimics the primary mechanisms of damage introduction and bending failure that typically occur in glass-based articles used in portable or handheld electronic devices. In the field, damage introduction occurs at the top surface of the glass-based article (FIG. 7a). Failure initiates at the top surface of the glass-based article, with damage penetrating the glass-based article (FIG. 7b), or propagating from the bending of the top surface of the glass-based article, or from an interior portion of the glass-based article (FIG. 7c). The IBoS test is designed to simultaneously damage the surface of the glass and apply bending under dynamic loads. In some instances, a glass-based article exhibits improved drop performance when subjected to compressive stress compared to the same glass-based article without compressive stress.

[0090] The IBoS testing apparatus is shown schematically in FIG. 6. The apparatus 500 includes a test stand 510 and a ball 530. The ball 530 is a hard or solid ball, such as a stainless steel ball. In one embodiment, the ball 530 is a 4.2 gram stainless steel ball with a diameter of 10 mm. The ball 530 is dropped directly onto a glass-based article sample 518 from a predetermined height h. The test stand 510 has a solid base 512 made of a hard, rigid material, such as granite. A sheet 514 having an abrasive surface is placed on top of the solid base 512 with the abrasive surface facing upward. In some embodiments, the sheet 514 is sandpaper with a 30-grit surface, and in other embodiments, it is sandpaper with a 180-grit surface. The glass-based article sample 518 is held above the sheet 514 by a sample holder 515 such that a gap 516 exists between the glass-based article sample 518 and the sheet 514. The gap 516 between the sheet 514 and the glass-based article sample 518 allows the glass-based article sample 518 to bend and touch the abrasion surface of the sheet 514 when impacted by the ball 530. In one embodiment, the glass-based article sample 518 is clamped at all corners to maintain bending only at the point of ball impact to ensure repeatability. In some embodiments, the sample holder 514 and test stand 510 are adapted to accommodate sample thicknesses up to about 2 mm. The gap 516 is in the range of about 50 μm to about 100 μm. The gap 516 is adapted to accommodate differences in material stiffness (Young's modulus, Emod), including the sample's Young's modulus and thickness. An adhesive tape 520 can be used to cover the top surface of the glass-based article sample 518 to recover fragments if the glass-based article sample 518 breaks upon impact with the ball 530.

[0091] A variety of materials can be used as the abrasive surface. In one particular embodiment, the abrasive surface is sandpaper, such as silicon carbide or alumina sandpaper, processed sandpaper, or any abrasive material known to those skilled in the art having comparable hardness and / or sharpness. In some embodiments, 30-grit sandpaper can be used, as it has a grain size and sharpness that produces a more consistent surface profile than either concrete or asphalt, and a desired level of damage to the sample surface.

[0092] In one embodiment, a method 600 for conducting an IBoS test using the apparatus 500 described above is shown in FIG. 8. In step 610, a glass-based article sample (218 in FIG. 6) is placed in the previously described test stand 510 and secured to a sample holder 515 such that an air gap 516 is formed between the glass-based article sample 518 and a sheet 514 having an abrasive surface. The method 600 assumes that the sheet 514 having an abrasive surface is already placed in the test stand 510. However, some embodiments include placing the sheet 514 in the test stand 510 with the surface having the abrasive material facing upward. In some embodiments (step 610a), an adhesive tape 520 is applied to the top surface of the glass-based article sample 518 before securing the glass-based article sample 518 in the sample holder 510.

[0093] In step 520, a solid ball 530 of predetermined mass and size is dropped from a predetermined height h onto the top surface of the glass-based article sample 518 such that the ball 530 impacts the top surface (or adhesive tape 520 applied to the top surface) approximately at the center of the top surface (i.e., within 1 mm, or 3 mm, or 5 mm, or 10 mm from the center). After the impact in step 520, the extent of damage to the glass-based article sample 518 is determined (step 630). As noted above, as used herein, the term "fracture" refers to the propagation of a crack through the entire thickness and / or surface of a substrate when the substrate is dropped or impacted by an object.

[0094] In method 600, the sheet 518 having a wear surface can be replaced after each drop to avoid the "aging" effect observed with repeated use of other types of drop test surfaces (e.g., concrete or asphalt).

[0095] Various predetermined drop heights h and increments are typically used in method 600. The test may, for example, utilize a minimum drop height (e.g., about 10-20 cm) to begin. The height may then be increased for successive drops by either set or variable increments. The test described in method 600 stops once the glass-based article sample 518 breaks or fractures (step 631). Alternatively, the drop test of method 300 may stop if the drop height h reaches a maximum drop height (e.g., about 100 cm) without fracture, or step 520 may be repeated at the maximum height until fracture occurs.

[0096] In some embodiments, the IBoS test of method 600 is performed only once on each glass-based article sample 518 at each predetermined height h. However, in other embodiments, each sample may be subjected to multiple tests at each height.

[0097] If failure of the glass-based article sample 518 occurs (step 631 in FIG. 8 ), IBoS testing according to method 600 is terminated (step 640). If failure is not observed upon ball drop at the predetermined drop height (step 632), the drop height is increased by a predetermined increment (step 634), e.g., 5, 10, 20 cm, etc., and steps 620 and 630 are repeated until sample failure is observed (631) or the maximum test height is reached without sample failure (636). Once either step 631 or 636 is reached, testing according to method 600 is terminated.

[0098] When subjected to the aforementioned inverted ball-on-sandpaper (IBoS) test, embodiments of the glass-based articles described herein have a survival rate of about 60% or greater when a ball is dropped onto the glass surface from a height of 100 cm. For example, a glass-based article is said to have a 60% survival rate when dropped from a given height if three out of five identical (or nearly identical) samples (i.e., having substantially the same composition and, if tempered, having substantially the same compressive stress and compression depth, or compressive stress layer as described herein) survive the IBoS drop test without breaking when dropped from the given height (here, 100 cm). In other embodiments, the survival rate of tempered glass-based articles in an 80 cm IBoS test is about 70% or greater, in other embodiments about 80% or greater, and in still other embodiments about 90% or greater. In other embodiments, the survival rate of a tempered glass-based article dropped from a height of 100 cm in the IBoS test is about 60% or greater, in other embodiments about 70% or greater, in still other embodiments about 80% or greater, and in other embodiments about 90% or greater. In one or more embodiments, the survival rate of a tempered glass-based article dropped from a height of 150 cm in the IBoS test is about 60% or greater, in other embodiments about 70% or greater, in still other embodiments about 80% or greater, and in other embodiments about 90% or greater.

[0099] To determine the survival rate of a glass-based article when dropped from a predetermined height using the IBoS test method and apparatus described above, at least five identical (or nearly identical) samples of the glass-based article (i.e., having approximately the same composition and, if tempered, approximately the same compressive stress and depth or layer of compression) are tested, although a greater number (e.g., 10, 20, 30, etc.) of samples can be tested to increase the confidence level of the test results. Each sample is dropped once from a predetermined height (e.g., 100 cm or 150 cm) or from progressively higher heights without breaking until it reaches the predetermined height, and then visually (i.e., with the naked eye) inspected for evidence of failure (i.e., crack formation and propagation throughout the thickness and / or surface of the sample). A sample is considered to have "survived" the drop test if no break is observed after being dropped from the predetermined height; if break is observed when the sample is dropped from a height equal to or less than the predetermined height, the sample is considered to have "failed" (or "not survived"). The survival rate is determined to be the percentage of the sample population that survived the drop test. For example, if seven samples out of a group of ten do not break when dropped from a given height, the survival rate of the glass is 70%.

[0100] The glass-based articles described herein may be transparent. In one or more embodiments, the glass-based article may have a thickness of about 3 millimeters or less, such as a thickness of 1 millimeter or less, and exhibit a transmittance of about 88% or greater over wavelengths in the range of about 380 nm to about 780 nm.

[0101] The glass-based article can also exhibit a substantially white color. For example, the glass-based article can exhibit CIELAB color space coordinates under CIE illuminant F02 of an L* value of about 88 or greater, an a* value within the range of about -3 to about +3, and a b* value within the range of about -6 to about +6. Alternatively, the glass-based article can exhibit CIELAB color space coordinates under CIE illuminant F02 of an L* value of about 40 or less, an a* value within the range of about -3 to about +3, and a b* value within the range of about -6 to about +6. Such color space coordinates may also exist under other CIE illuminants (e.g., D65).

[0102] The choice of substrate is not particularly limited. In some examples, the glass-based article can be described as having a high cation diffusivity for ion exchange. In one or more embodiments, the glass or glass ceramic has a fast ion exchange capacity, i.e., the glass or glass ceramic has a cation diffusivity of about 450 μm at 460° C. 2 / hour or more or approx. 500μm at 460℃ 2 In one or more embodiments, the glass or glass-ceramic exhibits a monovalent ion diffusivity of about 450 μm / hr at 460° C. 2 / hour or more or approx. 500μm at 460℃ 2 In one or more embodiments, the glass or glass-ceramic exhibits a sodium ion diffusivity of about 450 μm / hr at 460° C. 2 / hour or more or approx. 500μm at 460℃ 2 / hour or more potassium ion diffusivity.

[0103] The glass-based article may comprise an amorphous substrate, a crystalline substrate, or a combination thereof (e.g., a glass-ceramic substrate). In one or more embodiments, the glass-based article substrate (before being chemically strengthened as described herein) may have the following glass composition in mole percent (mol%):

[0104] SiO2 in the range of about 40 to about 80, Al2O3 in the range of about 10 to about 30, BO3 in the range of about 0 to about 10, RO in the range of about 0 to about 20, and RO in the range of about 0 to about 15. As used herein, RO refers to the total amount of alkali metal oxides such as Li2O, Na2O, KO, Rb2O, and Cs2O. RO refers to the total amount of alkaline earth metal oxides such as MgO, CaO, SrO, BaO, and ZnO. In some examples, the composition may include one or both of ZrO2 in the range of about 0 mol% to about 5 mol% and PO5 in the range of about 0 mol% to about 15 mol%. TiO2 may be present in an amount of about 0 mol% to about 2 mol%.

[0105] In some embodiments, the glass composition may include SiO2 in an amount, by mole percent, ranging from about 45 to about 80, from about 45 to about 75, from about 45 to about 70, from about 45 to about 65, from about 45 to about 60, from about 45 to about 65, from about 45 to about 65, from about 50 to about 70, from about 55 to about 70, from about 60 to about 70, from about 70 to about 75, from about 70 to about 72, or from about 50 to about 65.

[0106] In some embodiments, the glass composition may include Al2O3 in an amount, in mole percent, ranging from about 5 to about 28, from about 5 to about 26, from about 5 to about 25, from about 5 to about 24, from about 5 to about 22, from about 5 to about 20, from about 6 to about 30, from about 8 to about 30, from about 10 to about 30, from about 12 to about 30, from about 12 to about 18, or from about 12 to about 14.

[0107] In one or more embodiments, the glass composition may include B2O3 in an amount, in mole percent, ranging from about 0 to about 8, from about 0 to about 6, from about 0 to about 4, from about 0.1 to about 8, from about 0.1 to about 6, from about 0.1 to about 4, from about 1 to about 10, from about 2 to about 10, from about 4 to about 10, from about 2 to about 8, from about 0.1 to about 5, or from about 1 to about 3. In some instances, the glass composition may be substantially free of B2O3. As used herein, the phrase "substantially free" with respect to a component of a composition means that the component is not actively or intentionally added to the composition in the initial batch, but may be present as an impurity in an amount less than about 0.001 mole percent.

[0108] In some embodiments, the glass composition can include one or more alkaline earth metal oxides, such as MgO, CaO, and ZnO. In some embodiments, the total amount of the one or more alkaline earth metal oxides can be a non-zero amount up to about 15 mol%. In one or more specific embodiments, the total amount of any of the alkaline earth metal oxides can be a non-zero amount up to about 14 mol%, up to about 12 mol%, up to about 10 mol%, up to about 8 mol%, up to about 6 mol%, up to about 4 mol%, up to about 2 mol%, or up to about 1.5 mol%. In some embodiments, the total amount, in mol%, of the one or more alkaline earth metal oxides can be in the range of about 0.1 to 10, about 0.1 to 8, about 0.1 to 6, about 0.1 to 5, about 1 to 10, about 2 to 10, or about 2.5 to 8. The amount of MgO can be in the range of about 0 mol% to about 5 mol% (e.g., about 2 mol% to about 4 mol%). The amount of ZnO may be in the range of about 0 to about 2 mol % (e.g., about 0.1 mol % to about 2 mol %, about 0.1 mol % to about 1 mol %, or about 0.5 mol % to about 1.5 mol %). The amount of CaO may be about 0 mol % to about 2 mol %. In one or more embodiments, the glass composition may include MgO or may be substantially free of CaO and ZnO. In one variation, the glass composition may include either CaO or ZnO or may be substantially free of others of MgO, CaO, and ZnO. In one or more specific embodiments, the glass composition may include only two of the alkaline earth metal oxides MgO, CaO, and ZnO, and may be substantially free of a third earth metal oxide.

[0109] The total amount in mole percent of alkali metal oxides R2O2 in the glass composition may be in the range of about 5 to about 20, about 5 to about 18, about 5 to about 16, about 5 to about 15, about 5 to about 14, about 5 to about 12, about 5 to about 10, about 5 to about 8, about 5 to about 20, about 6 to about 20, about 7 to about 20, about 8 to about 20, about 8 to about 18, about 8 to about 16, about 8 to about 14, about 8 to about 12, or about 8 to about 11.

[0110] In one or more embodiments, the glass composition includes NaO in an amount ranging from about 0 mol% to about 18 mol%, from about 0 mol% to about 16 mol%, or from about 0 mol% to about 14 mol%, from about 0 mol% to about 12 mol%, from about 1 mol% to about 18 mol%, from about 1 mol% to about 16 mol%, from about 1 mol% to about 14 mol%, from about 1 mol% to about 12 mol%, from about 1 mol% to about 10 mol%, from about 1 mol% to about 8 mol%, from about 1 mol% to about 5 mol%, from about 1 mol% to about 4 mol%, or from about 1 mol% to about 3 mol%. In some embodiments, the composition may include less than about 4 mol% NaO.

[0111] In some embodiments, the amounts of LiO and NaO are controlled to specific amounts or ratios to balance formability and ion exchangeability. For example, increasing the amount of LiO reduces the liquidus viscosity, and some forming methods may not be usable. However, such glass compositions are ion-exchanged to deeper DOC levels as described herein. The amount of NaO can alter the liquidus viscosity but inhibit ion exchange to deeper DOC levels. In one or more embodiments, to achieve sufficient stress at a given depth in LiO-containing glass compositions (or compositions in which Na+ exchange for Li+ is the primary strengthening mechanism), the glass compositions of one or more embodiments include a LiO / (R2O) composition ratio greater than about 0.3, greater than about 0.45, greater than about 0.5, or greater than about 0.7. To maintain higher CS values ​​at greater depths in the glass-based articles described herein, particularly glass-based articles comprising NaO (or compositions in which the exchange of K+ for Na+ is the primary strengthening mechanism), the glass compositions of one or more embodiments comprise a compositional ratio of NaO / (RO) greater than about 0.3, greater than or equal to about 0.5, or greater than or equal to about 0.7.

[0112] In one or more embodiments, the glass composition may include KO in an amount less than about 5 mol%, less than about 4 mol%, less than about 3 mol%, less than about 2 mol%, or less than about 1 mol%. In one or more other embodiments, the glass composition may be substantially free of KO, as defined herein.

[0113] In one or more embodiments, the glass composition may contain Li2O in an amount of about 0 mol% to about 18 mol%, about 0 mol% to about 15 mol%, or about 0 mol% to about 10 mol%, about 0 mol% to about 8 mol%, about 0 mol% to about 6 mol%, about 0 mol% to about 4 mol%, or about 0 mol% to about 2 mol%. In some embodiments, the glass composition may contain Li2O in an amount of about 2 mol% to about 10 mol%, about 4 mol% to about 10 mol%, about 6 mol% to about 10 mol%, or about 5 mol% to about 8 mol%. In one or more other embodiments, the glass composition may be substantially free of Li2O, as defined herein.

[0114] In one or more embodiments, the glass composition may include FeO. In such embodiments, FeO may be present in an amount less than about 1 mol%, less than about 0.9 mol%, less than about 0.8 mol%, less than about 0.7 mol%, less than about 0.6 mol%, less than about 0.5 mol%, less than about 0.4 mol%, less than about 0.3 mol%, less than about 0.2 mol%, less than about 0.1 mol%, and all ranges and subranges therebetween. In one or more other embodiments, the glass composition may be substantially free of FeO, as defined herein.

[0115] In one or more embodiments, the glass composition may include ZrO. In such embodiments, ZrO may be present in an amount less than about 1 mol%, less than about 0.9 mol%, less than about 0.8 mol%, less than about 0.7 mol%, less than about 0.6 mol%, less than about 0.5 mol%, less than about 0.4 mol%, less than about 0.3 mol%, less than about 0.2 mol%, less than about 0.1 mol%, and all ranges and subranges therebetween. In one or more other embodiments, the glass composition may be substantially free of ZrO, as defined herein.

[0116] In one or more embodiments, the glass composition may contain P2O5 in the range of about 0 mol% to about 10 mol%, about 0 mol% to about 8 mol%, about 0 mol% to about 6 mol%, about 0 mol% to about 4 mol%, about 0.1 mol% to about 10 mol%, about 0.1 mol% to about 8 mol%, about 2 mol% to about 8 mol%, about 2 mol% to about 6 mol%, or about 2 mol% to about 4 mol%. In some examples, the glass composition may be substantially free of P2O5.

[0117] In one or more embodiments, the glass composition may include TiO. In such embodiments, TiO may be present in an amount less than about 6 mol%, less than about 4 mol%, less than about 2 mol%, or less than about 1 mol%. In one or more other embodiments, the glass composition may be substantially free of TiO, as defined herein. In some embodiments, TiO is present in an amount ranging from about 0.1 mol% to about 6 mol%, or from about 0.1 mol% to about 4 mol%.

[0118] In some embodiments, the glass composition can include various compositional relationships, such as a ratio of the amount of LiO (mol %) to the total amount of RO (mol %) ranging from about 0 to about 1, from about 0.4 to about 1, from about 0.45 to about 1, from about 0.5 to about 1, or from about 0.6 to about 1.

[0119] In some embodiments, the glass composition can include a difference between the total amount of R2O (mol %) and the amount of Al2O3 (mol %) (R2O-Al2O3) within a range of about -5 to about 2 (e.g., about -5 to about 1.5, about -5 to about 1, about -5 to about 0, about -5 to about -1, about -5 to about -2, about -4 to about 2, about -3 to about 2, about -2 to about 2, or about -3 to about -1).

[0120] In some embodiments, the glass composition can include a difference between the total amount of RxO (mol %) and the amount of Al2O3 (mol %) (RxO-Al2O3) within a range of about 0 to about 5 (e.g., about 0 to about 4, about 0 to about 3, about 0.1 to about 4, about 0.1 to about 3, about 1 to about 3, or about 1 to about 2). As used herein, RxO includes R2O and R0 as defined herein.

[0121] In some embodiments, the glass composition can have a ratio of the total amount of R2O (mol %) to the amount of Al2O3 (mol %) (R2O / Al2O3) in the range of about -4 to about 5, about -2 to about 4, or about 0.1 to about 5. For example, the ratio of the total amount of R2O (mol %) to the amount of Al2O3 (mol %) (R2O / Al2O3) may be within the range of about -4 to about 4.5, about -4 to about 4, about -4 to about 3.5, about -4 to about 3, about -4 to about 2.5, about -4 to about 2, about -4 to about 1.5, about -4 to about 1, about -3.5 to about 5, about -3 to about 5, about -2.5 to about 5, about -2 to about 5, about -1.5 to about 5, about -1 to about 5, about 0 to about 5, about 0 to about 4, about 0 to about 3, about 0.1 to about 4, about 0.1 to about 3, or about 0.1 to about 2.

[0122] In one or more embodiments, the glass composition has a combined amount of Al2O3 and Na2O of about 15 mol% or less (e.g., 14 mol% or less, 13 mol% or less, 12 mol% or less, 11 mol% or less, or about 10.5 mol% or less). The combined amount of Al2O3 and Na2O may be greater than about 5 mol%.

[0123] The glass composition of one or more embodiments can exhibit a ratio of the amount of MgO (mol %) to the total amount of RO (mol %) in the range of about 0 to about 1. In some embodiments, the MgO / RO ratio is in the range of about 0 to about 0.9, about 0 to about 0.8, about 0 to about 0.7, about 0 to about 0.6, about 0 to about 0.5, about 0.1 to about 1, about 0.2 to about 1, about 0.3 to about 1, about 0.4 to about 1, or about 0.5 to about 1.

[0124] In some embodiments, the glass composition may be substantially free of nucleating agents. Typical examples of nucleating agents include TiO2, ZrO2, etc. Nucleating agents are constituents in glass that can be described in terms of their function of initiating the formation of crystallites in the glass.

[0125] In some embodiments, the composition used in the glass substrate can be batch-formed using about 0 mol % to about 2 mol % of at least one fining agent selected from any one or more of Na2SO4, NaCl, NaF, NaBr, K2SO4, KCl, KF, KBr, As2O3, Sb2O3, and SnO2. The glass composition according to one or more embodiments can further include SnO2 in the range of about 0 to about 2, about 0 to about 1, about 0.1 to about 2, about 0.1 to about 1, or about 1 to about 2. The glass compositions disclosed herein can be substantially free of As2O3 and / or Sb2O3.

[0126] In one or more embodiments, the composition may specifically include 62 mol% to 75 mol% SiO, 10.5 mol% to about 17 mol% AlO, 5 mol% to about 13 mol% LiO, 0 mol% to about 4 mol% ZnO, 0 mol% to about 8 mol% MgO, 2 mol% to about 5 mol% TiO, 0 mol% to about 4 mol% BO, 0 mol% to about 5 mol% NaO, 0 mol% to about 4 mol% KO, 0 mol% to about 2 mol% ZrO, 0 mol% to about 7 mol% PO, 0 mol% to about 0.3 mol% FeO, 0 mol% to about 2 mol% MnO, and 0.05 mol% to about 0.2 mol% SnO.

[0127] In one or more embodiments, the composition can include 67 mol% to about 74 mol% SiO, 11 mol% to about 15 mol% AlO, 5.5 mol% to about 9 mol% LiO, 0.5 mol% to about 2 mol% ZnO, 2 mol% to about 4.5 mol% MgO, 3 mol% to about 4.5 mol% TiO, 0 mol% to about 2.2 mol% BO, 0 mol% to about 1 mol% NaO, 0 mol% to about 1 mol% KO, 0 mol% to about 1 mol% ZrO, 0 mol% to about 4 mol% PO, 0 mol% to about 0.1 mol% FeO, 0 mol% to about 1.5 mol% MnO, and 0.08 mol% to about 0.16 mol% SnO.

[0128] In one or more embodiments, the composition can include 70 mol% to 75 mol% SiO, 10 mol% to about 15 mol% AlO, 5 mol% to about 13 mol% LiO, 0 mol% to about 4 mol% ZnO, 0.1 mol% to about 8 mol% MgO, 0 mol% to about 5 mol% TiO, 0.1 mol% to about 4 mol% BO, 0.1 mol% to about 5 mol% NaO, 0 mol% to about 4 mol% KO, 0 mol% to about 2 mol% ZrO, 0 mol% to about 7 mol% PO, 0 mol% to about 0.3 mol% FeO, 0 mol% to about 2 mol% MnO, and 0.05 mol% to about 0.2 mol% SnO.

[0129] Other exemplary compositions of the glass-based articles described herein before chemical strengthening are shown in Table 1A. Table 1B lists selected physical properties determined for the examples listed in Table 1A. The physical properties listed in Table 1B include density; low- and high-temperature CTE; strain, annealing and softening points; 10 poise, 35 kP, 200 kP, liquidus, and zircon fracture temperatures; zircon decomposition and liquidus viscosity; Poisson's ratio; Young's modulus; refractive index, and stress-optical coefficient. In some embodiments, the glass-based articles and glass substrates described herein have a high-temperature CTE of 30 ppm / °C or less and / or a Young's modulus of 70 GPa or more, and in some embodiments, a Young's modulus of up to 80 GPa.

[0130] [Table 1A]

[0131] [Table 1B]

[0132] Table 1C shows the properties of Example H after being ion-exchanged in a molten salt bath having 80% KNO3 and 20% NaNO3 at a temperature of 430°C for 16 hours.

[0133] [Table 1C]

[0134] Here, the glass-based article comprises a glass-ceramic, and the crystalline phase may include β-spodumene, rutile, gahnite, or other known crystalline phases and combinations thereof.

[0135] The glass-based article may be substantially planar, although other embodiments may utilize curved or other shaped or engraved substrates. In some examples, the glass-based article may have a 3D or 2.5D shape. The glass-based article may be substantially optically clear, transparent, and free of light scattering. The glass-based article may have a refractive index in the range of about 1.45 to about 1.55. As used herein, refractive index values ​​are for a wavelength of 550 nm.

[0136] Additionally, or alternatively, the thickness of the glass-based article may be constant along one or more dimensions, or may vary along one or more of its dimensions for aesthetic and / or functional reasons. For example, the edges of the glass-based article may be thicker than more central regions of the glass-based article. The length, width, and thickness dimensions of the glass-based article may also vary depending on the application or use of the article.

[0137] Glass-based articles can be characterized by the method by which they are formed. For example, glass-based articles can be characterized as float-formable (i.e., formed by a float process), down-drawable, and particularly fusion-formable, or slot-drawable (i.e., formed by a down-draw process such as a fusion draw process or a slot draw process).

[0138] Float-formable glass-based articles are characterized by smooth surfaces and uniform thicknesses created by molten glass floating on a layer of molten metal, typically tin. In one exemplary process, molten glass is dispensed onto the surface of the molten tin layer to form a floating glass ribbon. As the glass ribbon flows along the tin bath, its temperature gradually decreases until it solidifies into a solid glass-based article, which can then be pulled from the tin onto rollers. Once out of the bath, the glass-based article can be further cooled and annealed to reduce internal stresses. In some cases, the glass-based article is a glass-ceramic, and float-formed glass-based articles can be subjected to a ceramming process to produce one or more crystalline phases.

[0139] The down-draw process produces glass-based articles of uniform thickness with relatively pristine surfaces. Because the average flexural strength of a glass-based article is controlled by the amount and size of surface flaws, pristine surfaces with fewer contacts have higher initial strength. When these high-strength glass-based articles are subsequently further strengthened (e.g., chemically), the resulting strength can be greater than that of glass-based articles with covered and polished surfaces. Down-draw glass-based articles can be drawn to thicknesses of less than about 2 mm. Furthermore, down-draw glass-based articles have very flat, smooth surfaces that can be used for end-use applications without expensive grinding and polishing. Here, the glass-based article is a glass-ceramic, and glass-based articles formed from the down-draw process can be subjected to a ceramming process to produce one or more crystalline phases.

[0140] The fusion draw process, for example, uses a drawing tank with a channel for receiving molten glass raw material. The channel has upwardly open weirs on both sides of the channel along the length of the channel. When the channel is filled with molten material, the molten glass overflows the weirs. Due to gravity, the molten glass flows down the outer surface of the drawing tank as two flowing glass films. These outer surfaces of the drawing tank extend downward and inward to meet at the lower edge of the drawing tank. The two flowing glass films meet and fuse at this edge to form a single flowing glass-based article. The fusion draw method offers the advantage that, as the two glass films flowing over the channel fuse together, neither of the outer surfaces of the resulting glass-based article comes into contact with any part of the equipment. This means that the surface properties of the fusion-draw glass-based article are not affected by such contact. Here, the glass-based article is a glass-ceramic, and the glass-based article formed from the fusion process can be subjected to a ceramming process to produce one or more crystalline phases.

[0141] The slot-draw process differs from the fusion draw process. In the slot-draw process, molten raw glass is fed into a drawing tank. The bottom of the drawing tank has an open slot with a nozzle extending the length of the slot. The molten glass flows through the slot / nozzle and is drawn downward as a continuous glass-based article, entering an annealing zone. Here, the glass-based article is a glass-ceramic; glass-based articles formed from the slot-draw process can be subjected to a ceramming process to produce one or more crystalline phases.

[0142] In some embodiments, the glass-based article can be formed using a thin rolling process as described in U.S. Patent No. 8,713,972, entitled "Precision Glass Roll Forming Process and Apparatus," U.S. Patent No. 9,003,835, entitled "Precision Roll Forming of Textured Sheet Glass," U.S. Patent Publication No. 20150027169, entitled "Method and Apparatus for Forming Glass Ribbons," and U.S. Patent Publication No. 20050099618, entitled "Apparatus and Method for Forming Thin Glass Articles," the contents of which are incorporated herein by reference in their entireties. More specifically, the glass-based article can be formed by providing a vertical flow of molten glass and shaping a supplied stream of molten glass or glass-ceramic using a pair of forming rolls maintained at a surface temperature of about 500°C or greater, or about 600°C or greater, to form a formed glass ribbon having a formed thickness, and sizing the formed glass ribbon using a pair of sizing rolls maintained at a surface temperature of about 400°C or less to create a sized glass ribbon having a desired thickness less than the formed thickness and a desired thickness uniformity. The apparatus used to form the glass ribbon may include: a glass supply device that supplies a supplied stream of molten glass; a pair of forming rolls maintained at a surface temperature of about 500°C or greater, the pair of forming rolls being closely spaced apart to define a glass forming gap between the forming rolls, the glass forming gap being vertically disposed below the glass supply device to receive the supplied stream of molten glass and attenuate the supplied stream of molten glass between the forming rolls to form a formed glass ribbon having a formed thickness; and a pair of sizing rolls maintained at a surface temperature of about 400°C or less, the pair of sizing rolls being closely spaced apart to define a glass sizing gap between the sizing rolls, the glass sizing gap being vertically disposed below the forming rolls to receive the formed glass ribbon and attenuate the formed glass ribbon to produce a sized glass ribbon having a desired thickness and a desired thickness uniformity.

[0143] In some instances, when the viscosity of the glass does not allow for the use of fusion or slot draw methods, thin-rolling processes can be utilized. For example, when the glass exhibits a liquidus viscosity of less than 100 kP, thin-rolling can be utilized to form glass-based articles.

[0144] Glass-based articles may be acid-abraded or otherwise treated to remove or reduce the effects of surface scratches. Another aspect of the present disclosure relates to devices comprising the glass-based articles described herein. For example, the device can include any device that includes a display or requires tempered thin glass. In one or more embodiments, the device is an electronic device, which may include a portable device such as a cell phone, laptop, tablet, MP3 player, navigation device, etc., or a stationary device such as a computer, electronic display, in-vehicle information / entertainment system, billboard, point of sale system, navigation system, etc. In some embodiments, the glass-based articles described herein can be incorporated into architectural articles (walls, fixtures, panels, windows, etc.), transportation articles (e.g., glazing or interior trim in automotive applications, trains, aircraft, marine vessels, etc.), appliances (e.g., washers, dryers, dishwashers, refrigerators, etc.), or any article requiring some degree of fracture resistance. As shown in FIG. 39, an electronic device 1000 can include a glass-based article 100 according to one or more embodiments described herein. The device 100 includes a housing 1020 having a front surface 1040, a back surface 1060, and sides 1080; and electrical components (not shown) at least partially within or entirely within the housing, including at least a controller, memory, and a display 1120 located on or adjacent to the front surface of the housing. The glass-based article 100 is shown as a cover disposed on or over the front surface of the housing, overlying the display 1120. In some embodiments, the glass-based article can be used as a back cover.

[0145] Another aspect of the present disclosure relates to a method for forming a fracture-resistant glass-based article. The method includes providing a glass-based substrate having a first surface and a second surface defining a thickness of about 3 millimeters or less, e.g., 1 millimeter or less, and generating a stress profile in the glass-based substrate as described herein to provide the fracture-resistant glass-based article. In one or more embodiments, generating the stress profile includes ion-exchanging a plurality of alkali ions into the glass-based substrate to form a non-zero alkali metal oxide concentration that varies along a substantial portion (as described herein) or the entire thickness. In one example, generating the stress profile includes immersing the glass-based substrate in a molten salt bath containing nitrates of Na+, K+, Rb+, Cs+, or a combination thereof at a temperature of about 350°C or greater (e.g., about 350°C to about 500°C). In one example, the molten bath can include NaNO3, KNO3, or a combination thereof and can have a temperature of about 485°C or less. In another example, the bath can include a mixture of NaNO3 and KNO3 and can have a temperature of about 460°C. The glass substrate can be immersed in the bath for at least about 2 hours and up to about 48 hours (e.g., about 2 hours to about 10 hours, about 2 hours to about 8 hours, about 2 hours to about 6 hours, about 3 hours to about 10 hours, or about 3.5 hours to about 10 hours).

[0146] In some embodiments, the method can include chemically strengthening or ion-exchanging a glass-based substrate in a single bath or in multiple steps using sequential immersion steps in multiple baths. For example, two or more baths can be used sequentially. The composition of one or more baths can include a single metal (e.g., Ag+, Na+, K+, Rb+, or Cs+) or a combination of metals in the same bath. When two or more baths are utilized, the baths can have the same or different compositions and / or temperatures. The immersion time in each such bath can be the same or can be varied to provide a desired stress profile.

[0147] In one or more embodiments of this method, a second or subsequent bath can be utilized to generate larger surface Cs. In some examples, the method includes immersing the glass-based substrate in a second or subsequent bath to generate larger surface Cs without significantly affecting the chemical depth and / or DOC of the layer. In such embodiments, the second or subsequent bath can include a single metal (e.g., KNO or NaNO) or a mixture of metals (e.g., KNO and NaNO). The temperature of the second or subsequent bath can be adjusted to generate larger surface Cs. In some embodiments, the immersion time of the glass-based substrate in the second or subsequent bath can also be adjusted to generate larger surface Cs without affecting the chemical depth and / or DOC of the layer. For example, the immersion time in the second or subsequent bath can be less than 10 hours (e.g., about 8 hours or less, about 5 hours or less, about 4 hours or less, about 2 hours or less, about 1 hour or less, about 30 minutes or less, about 15 minutes or less, or about 10 minutes or less).

[0148] In one or more alternative embodiments, the method can include one or more heat treatment steps that can be used in combination with the ion exchange methods described herein. The heat treatment involves heat treating the glass-based article to achieve a desired stress profile. In some embodiments, the heat treatment involves annealing, tempering, or heating the glass-based substrate to a temperature in the range of about 300°C to about 600°C. The heat treatment can last from 1 minute to about 18 hours. In some embodiments, the heat treatment can be used after or between one or more ion exchange processes. [Example]

[0149] Various embodiments will be further clarified by the following examples. In the examples, before tempering, the examples are referred to as "substrates." After tempering, the examples are referred to as "articles" or "glass-based articles."

[0150] Example 1 Glass-ceramic substrates were provided having the nominal composition shown in Table 2 below. The glass-ceramic substrates had a thickness of 0.8 millimeters and contained a crystalline phase population including a β-spodumene solid solution as a predominant crystalline phase and one or more minor phases including rutile. The glass-ceramic substrates were immersed in a molten salt bath containing NaNO at a temperature of 485°C for 10 hours (Condition A), 13 hours (Condition B), or 24 hours (Condition C), or in a molten salt bath containing NaNO at a temperature of 430°C for 2 hours (Comparative Condition D) to form glass-ceramic articles.

[0151] [Table 2]

[0152] The chemical profile of the glass-ceramic article was measured by microprobe and is shown in Figure 9. Stress is proportional to concentration according to equation (4).

[0153] Sigma(z)=BE / 1-n(Cavg-C(z)) (4) In equation (4), B is the lattice expansion coefficient, E is Young's modulus, n is Poisson's ratio, and C is the integral of the concentration across the sample. As shown in Figure 9, Na+ ions are exchanged through nearly the entire thickness of the article when higher temperature baths are used (i.e., conditions A-C). In such glass-ceramics, NaO is present in the CT region in amounts of about 1.2 mol % or greater. Glass-ceramic articles ion-exchanged in lower temperature baths (comparative condition D) exhibited stress profiles similar to known stress profiles.

[0154] Example 2 Glass substrates with the same composition as shown in Table 2, but with a thickness of 0.8 mm and an amorphous structure (no crystalline phases present), were chemically strengthened to provide glass articles by immersion in a molten salt bath containing 100% NaNO3 at a temperature of approximately 430 °C for various durations. The DOC and maximum CT values ​​of the glass articles were measured using SCALP. As shown in Figure 10, the increase in DOC and maximum CT depended on the length of immersion or ion exchange. The maximum CT value was observed after the glass was immersed for approximately 16 hours.

[0155] The stress profile of the glass article of Example 2 was measured using SCALP and is shown in Figure 11. The upper portion of the y-axis, representing positive stress values, is the CT layer, and the lower portion of the y-axis, representing negative stress values, is the CS value. The stress profile of the glass article chemically strengthened for 16 hours exhibited a maximum CT value (i.e., 175 MPa) and a parabolic shape without a substantially flat portion in the 100 μm depth direction. The surface CS measured by SCALP was approximately 410 MPa. Therefore, the ratio of the maximum CT to the absolute value of the surface CS for Example 2 is approximately 0.4375. In Figure 11, positive numbers are used for compressive stresses, and negative numbers indicate tensile stresses. This same convention (compressive stresses are indicated by positive values ​​on the y-axis and tensile stresses are indicated by negative values ​​on the y-axis) is also used in Figures 1-3 and 33. However, in the remaining figures, compressive stresses are indicated by negative values ​​on the y-axis and tensile stresses are indicated by positive values ​​on the y-axis.

[0156] Example 3 For comparison, the glass-ceramic substrate of Example 1 and the glass substrate of Example 2, each about 0.8 mm thick, were chemically strengthened by immersion in a molten salt bath of NaNO at a temperature of 350°C for 3.5 hours (Examples 3A and 3B, respectively). The resulting stress profiles (approximated by the chemical profiles measured by the microprobe using Equation 4) of the glass-ceramic and glass articles shown in Figure 12 resemble an error function (erfc) or quasi-linear. Furthermore, the CS depth of the layer is smaller than the depth of alkali ion-exchanged (or chemical ion-exchange depth) into the glass or glass-ceramic.

[0157] When the glass-ceramic substrate of Example 1 and the glass substrate of Example 2, each having a thickness of approximately 0.8 mm, were subjected to the chemical strengthening described herein by immersion in a molten salt bath of NaNO at a temperature of 430°C for 24 hours (Examples 3C and 3D, respectively), the resulting glass-based articles exhibited metal oxide concentration profiles (obtained by EPMA) as shown in Figure 13. The metal oxide concentration profile was parabolic, indicating ion exchange of Na+ ions throughout the thickness. The chemical profile was measured using EMPA, and the chemical depth of NaO diffusion was shown to be greater than 400 micrometers. Furthermore, NaO was present throughout the thickness, including in the CT layer, at a concentration of greater than about 1 mol%. The resulting glass-ceramic article of Example 3D exhibited excellent fracture resistance in a drop test in which the glass-ceramic substrate was incorporated into the same mobile phone housing. Specifically, five samples of Example 3D were incorporated into a mobile phone device and dropped successively onto sandpaper, starting from a height of 50 cm. As each sample survived the drop from one height, it was dropped again from an increased height until failure, at which point the defect height for that sample was recorded in Figure 13A. Example 3D exhibited an average defect height of 172.5 cm.

[0158] Figure 14 shows stress profiles for glass-based substrates chemically strengthened according to known methods and glass-based substrates chemically strengthened according to methods described herein. As shown in Figure 14, the stress profile of the glass-based article of embodiments described herein has a shape that is substantially free of flat portions (having a length or absolute depth greater than about 50 micrometers) and exhibits a DOC of about 0.2 t, while the known stress profile exhibits a substantially linear and / or flat portion at a depth of about 0.1 millimeter to about 0.7 millimeters (a total length of about 0.6 millimeters or 600 micrometers). The known stress profile also exhibits a lower CT value and a lower DOC.

[0159] Example 4 Glass substrates (each approximately 1 mm thick) having the compositions in Table 2 were chemically strengthened by immersion in a first molten salt bath of NaNO at a temperature of 430°C for 24 hours. One glass-based article did not undergo a further strengthening step (Example 4A). Three glass-based articles were subjected to a second strengthening step by immersion in a second molten salt bath of KNO at a temperature of approximately 430°C for either 0.75 hours, 4 hours, or 8 hours (Examples 4B, 4C, and 4D, respectively). The stress profiles of the resulting glass-based articles measured by SCALP are shown in Figure 15, where the depth or thickness of the glass-based article is plotted on the x-axis and stress is plotted on the y-axis. Positive stress values ​​are CT values, and negative stress values ​​are CS values. The spatial resolution of the instrument prohibits measurement of CS associated with the second KNO ion-exchange step. The glass-based articles of Examples 4A and 4B exhibited similar profiles. The glass-based articles of Examples 4C and 4D exhibited a decreased CT (compared to Examples 4A and 4B) and a decreased CS (compared to Examples 4A and 4B) over time and after immersion in the second tempering step. The glass-based articles of Examples 4C and 4D also exhibited an increased DOC compared to Examples 4A and 4B, such DOC values ​​being greater than 0.2 t.

[0160] FIG. 16 shows the stored tensile energy in J / m for each of Examples 4B to 4D. 2 and 15 J / m depending on the time of immersion in the second molten salt bath of KNO3. 2 The stored tensile energy can be calculated from the measured SCALP stress profile data using equation (2) above.

[0161] Figures 17 and 18 show the respective concentration profiles of KO and NaO as a function of depth (in micrometers) for each of Examples 4B-4D. As shown in Figure 17, the chemical depth of KO is 3 micrometers (Example 4B, immersed in a KNO bath for 0.75 hours), 6 micrometers (Example 4C, immersed in a KNO bath for 4 hours), and 5 micrometers (Example 4D, immersed in a KNO bath for 8 hours). As shown in Figure 18, NaO penetrates the entire depth and has a concentration of about 1 mol % or greater along the entire depth of the glass-based article for each of Examples 4B-4D.

[0162] Examples 4E and 4F comprise glass substrates (each approximately 1 mm thick) having the compositions in Table 2, which were chemically strengthened by immersion in a first molten salt bath of NaNO at 430°C for 24 hours, followed by heat treatment in air at 430°C for 4 hours or 8.25 hours, respectively. The stress profiles for the glass-based articles of Examples 4E and 4F are shown in Figure 19, along with the stress profiles of Examples 4A, 4C, and 4D for comparison. Figure 20 shows the same graph as Figure 19, but on a smaller scale to illustrate the difference in stress profiles at or near a depth of 0.5 t.

[0163] Example 5 Glass substrates (each approximately 1 mm thick) having the compositions shown in Table 2 were chemically tempered by immersion in a first molten salt bath of NaNO3 at a temperature of 430°C for 24 hours. One glass-based article was not subjected to an additional tempering step (Example 5A). Two glass-based articles were subjected to a second tempering step by placing the glass-based articles in a furnace at 390°C and maintaining the glass-based articles in the furnace for approximately 8 hours or 28 hours (Examples 5B and 5C, respectively). Four glass-based articles were subjected to a third tempering step (after either the first tempering step or a different second tempering step) by immersion in a second molten salt bath of KNO3 at a temperature of 430°C for 4 hours or 8 hours (Examples 5D-5G). The tempering steps for each of Examples 5A-5G are shown in Table 3. The measured CT values ​​are also shown in Table 3.

[0164] [Table 3]

[0165] The resulting stress profile of the glass-based article is shown in Figure 21, with the depth or thickness of the glass-based article plotted on the x-axis and stress plotted on the y-axis. Positive stress values ​​are CT values ​​and negative stress values ​​are CS values. As shown in Figure 21, as the duration of the second and / or third heat treatments increased, the DOC increased and the CT decreased. The decrease in DOC and CT is more clearly shown in Figures 22 and 23, respectively.

[0166] The glass-based articles of Examples 5A-5G were then subjected to a poke test in which one side of the glass-based article was attached to tape and a sharp instrument was struck against the other bare side to break the article. The number of fragments obtained can be correlated to the stored tensile energy of the glass-based article. Examples 5A, 5B, and 5D exhibited a large number of fragments (i.e., more than 50 and even 100 fragments), while Example 5F exhibited 10 fragments, Example 5C exhibited 3 fragments, and Examples 5E and 5G exhibited 4 fragments. Examples 5A, 5B, and 5D, which broke into numerous fragments, exhibited a higher CT (greater than about 100 MPa) than Examples 5C, 5E, 5F, and 5G, all of which had CT values ​​of about 100 MPa or less.

[0167] Example 6 Glass substrates having the nominal composition shown in Table 2 and each having a thickness of approximately 1 mm were subjected to chemical strengthening in a molten salt bath containing 100% NaNO at a temperature of 430° C. The immersion times of the glass substrates in the molten salt bath are shown in Table 5.

[0168] [Table 4]

[0169] The stress profiles of the glass-based articles of Examples 6A-6G are shown in Figure 24. The stress profiles were measured using SCALP. As shown in Figure 24, immersion of the glass substrates in the molten salt bath for 16 and 24 hours resulted in glass-based articles exhibiting the maximum absolute surface CS and CT values. Graphs showing the change in CT value and stored tensile energy as a function of ion-exchange time are shown in Figure 25.

[0170] Example 7 Glass substrates having the nominal compositions shown in Table 2 and each having a thickness of approximately 0.8 mm were chemically strengthened in a molten salt bath containing a mixture of NaNO3 and NaSO4 at a temperature of 500°C for 15 minutes (Comparative Example 7A) and 16 hours (Example 7B). The stress profiles of the glass-based articles of Examples 7A and 7B are shown in Figure 26. As shown in Figure 26, Comparative Example 7A exhibited a known stress profile, while Example 7B exhibited a stress profile according to one or more embodiments of the present disclosure. The retained tensile energy of the glass-based articles of Examples 7A and 7B was calculated in the same manner as Examples 4B-4D. The calculated retained tensile energy is plotted as a function of the measured CT (MPa), as shown in Figure 27.

[0171] As shown in Figure 27, for a given CT value, Comparative Example 7A exhibited a much higher stored tensile energy value than Example 7B (for the same CT value). In this figure, CT is the maximum CT among the samples. Specifically, at a CT of about 55 MPa, Comparative Example 7A exhibited a stored tensile energy value of about 12.5 J / m 2 Example 7B showed a stored tensile energy of about 9 J / m 2The stored tensile energy of Comparative Example 7A was 0.01. When Comparative Example 7A and Example 7B were fractured, Example 7B fractured into a smaller number of fragments than Comparative Example 7A, which fractured into a significantly larger number of fragments. Therefore, without being bound by theory, it is believed that controlling the stored tensile energy may provide a way to control or predict the fragmentation pattern or number of fragments resulting from fracture. In these examples, the same bath temperature and composition were used, but the CT was changed by maintaining the sample in the ion exchange bath for an extended period of time. In Figure 27, point 0 was not experimentally determined, but one skilled in the art would predict that this would be the case: if the CT is 0, the stored tensile energy is 0.

[0172] Glass substrates having the nominal compositions shown in Table 2 and each having a thickness of approximately 1 mm were chemically strengthened in a molten salt bath containing NaNO at a temperature of 430°C for 4 hours (Comparative Example 7C) and 61.5 hours (Example 7D). Comparative Example 7C exhibited a known stress profile, while Example 7D exhibited a stress profile in accordance with one or more embodiments of the present disclosure. The retained tensile energy of Examples 7C and 7D was calculated using the same method used for Examples 4B-4D and plotted as a function of the measured CT (MPa), as shown in Figure 28.

[0173] As shown in Figure 28, for a given CT value, Comparative Example 7C exhibited significantly greater stored tensile energy values ​​than Example 7D (for the same CT value) (again, as in Figure 27, these were at the maximum CT values, and similarly, the same ion exchange bath temperature and composition, but longer time, were used to vary the values). When Comparative Example 7C and Example 7D were fractured, Example 7D fractured into significantly fewer pieces than Comparative Example 7C, which fractured into significantly more pieces.

[0174] Example 8 A glass substrate having a nominal composition of 70.9 mol % SiO2, 12.8 mol % Al2O3, 1.95 mol % B2O3, 7.95 mol % Li2O, 2.43 mol % Na2O, 2.98 mol % MgO, 0.89 mol % ZnO, and 0.1 mol % SnO2 and a thickness of approximately 0.8 mm was subjected to the ion exchange conditions in Table 5. Table 6 compares various properties of Example 8 with Example 2.

[0175] [Table 5]

[0176] [Table 6]

[0177] The stress profile of the glass-based article of Example 8 was measured and exhibited the shape described herein.

[0178] Glass substrates according to Example 2, Comparative Examples 8A, and 8B were provided with the same thickness as Example 8. The glass substrate according to Example 2 was ion-exchanged in a molten bath of 100% NaNO at a temperature of 430°C for 33 hours. Comparative Example 8A was ion-exchanged in a molten bath of 100% NaNO at a temperature of 390°C for 16 hours and also exhibited a known error function stress profile. The glass substrate according to Example 8B, having a nominal composition of 57.5 mol% SiO, 16.5 mol% AlO, 16.7 mol% NaO, 2.5 mol% MgO, and 6.5 mol% PO, was ion-exchanged and exhibited a known error function stress profile. As used herein, the term "error function stress profile" refers to a stress profile similar to that shown in FIG. 1.

[0179] Next, the glass-based articles from Example 2, Example 8, and Comparative Examples 8A and 8B were assembled into the same mobile phone device. The phone device was dropped onto 30-grit sandpaper from increasing heights, starting at 20 centimeters. If the glass-based article survived the drop from one height (e.g., 20 cm), the mobile phone was dropped again from a greater height (e.g., 30 cm, 40 cm, 50 cm, etc.). The height at which the glass-based article developed defects is plotted in Figure 29, which also shows the average defect height for samples from Examples 2 and 8 and Comparative Examples 8A and 8B. As shown in Figure 29, Examples 2 and 8 exhibited defects at significantly higher drop heights than Comparative Examples 8A and 8B. Specifically, Comparative Examples 8A and 8B exhibited defects at drop heights of approximately 38 cm and 55 cm, respectively, while Examples 2 and 8 exhibited defects at drop heights of approximately 147 cm and 132 cm, respectively.

[0180] The same test was repeated on new samples using the same cell phone device on 180 grit sandpaper. The average defect height for Comparative Example 8A was 204 cm, the average defect height for Comparative Example 8B was 190 cm, the average defect height for Example 2 was 214 cm, and the average defect height for Example 8 was 214 cm.

[0181] A glass substrate according to Comparative Example 8C having a nominal composition of 65 mol% SiO2, 5 mol% B2O3, 14 mol% Al2O3, 14 mol% Na2O, 2 mol% MgO, and 0.1 mol% SnO2 and a thickness of 0.8 mm was ion-exchanged and exhibited the known error function stress profile. The glass-based article samples of Example 2 and Comparative Example 8B (which exhibit the above stress profile in this example), the glass-based article of Comparative Example 8C, and the glass-based article of Example 8 ion-exchanged according to Condition 4 as shown in Table 5 were subjected to the A-ROR test described herein.

[0182] Examples 6 and 8 and Comparative Example 8C were abraded using loads or pressures of 25 psi and 45 psi, while Example 2 was abraded using only a 25 psi load. The AROR data is shown in Figure 30. As shown in Figure 30, Examples 2 and 8 exhibited higher failure loads than Comparative Example 8B and Comparative Example 8C at each abrasion load or pressure.

[0183] Four-point bend tests were performed on the glass-based article sample of Example 2 (ion-exchanged as described above in this example) and the glass-based article sample of Example 8 (ion-exchanged under Condition 4). The results are shown in the Weibull distribution diagram of Figure 31. As shown in Figure 31, Example 8 exhibited a higher stress or failure load (e.g., greater than about 400 MPa).

[0184] As noted above, glass-based articles made from compositions with strain points greater than 525°C allow for ion exchange temperatures (or ion exchange bath temperatures) within the range of about 350°C to about 480°C. In some embodiments, glass compositions exhibiting monovalent ion diffusivities greater than about 800 square micrometers / hour allow metal oxides diffusing into the glass-based article to quickly penetrate the entire depth or thickness of the article so that stress relaxation is minimized. Excess stress relaxation can reduce surface compressive stresses in the glass-based article.

[0185] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention.

[0186] Example 9 Glass substrates having the same composition as in Example 8 and a thickness of approximately 0.8 mm were ion-exchanged by immersion in a 100% NaNO molten salt bath at a temperature of 430°C according to the conditions shown in Table 7. The resulting glass-based articles exhibited maximum CT values, which are plotted as a function of ion-exchange time in Figure 32.

[0187] [Table 7]

[0188] The stress profile of Example 9D was measured using refractive near-field (RNF) measurements, as described in U.S. Patent No. 8,854,623, entitled "System and Method for Measuring Profile Properties of Glass Samples," which is incorporated herein by reference in its entirety. Figure 33 shows the measured stress as a function of depth extending into the glass-based article from the surface of the glass-based article of Example 9D. The stress at specific depths, including the "knee," which is the depth where the stress slope changes abruptly, is shown in Table 8.

[0189] [Table 8]

[0190] Example 10 Example 10A included a 0.8 mm thick glass substrate having the same composition as Example 1. The glass substrate was ion-exchanged for 16 hours in a single molten salt bath containing 80% KNO and 20% NaNO and having a temperature of about 430° C. The resulting glass-based article exhibited a stress profile as set forth in Table 9.

[0191] [Table 9]

[0192] The glass-based articles according to Example 10A were subjected to the AROR test described herein. One set of the glass-based articles was abraded using a load or pressure of 5 psi, a second set of the glass-based articles was abraded using a load or pressure of 25 psi, and a third set of the glass-based articles was abraded using a load or pressure of 45 psi. The AROR data is shown in Figure 34. As shown in Figure 34, all of the glass-based articles according to Example 10A exhibited an average failure load of greater than about 25 kgf.

[0193] The glass-based articles according to Example 10A were incorporated into identical mobile phone devices. The phone devices were dropped onto 180-grit sandpaper from increasing heights, starting from 20 centimeters. If the glass-based article survived the drop from one height (e.g., 20 cm), the phone was dropped again from higher heights (e.g., 30 cm, 40 cm, 50 cm, etc.) up to 225 cm. The surviving glass-based article was then dropped onto 30-grit sandpaper (within the same phone device). The heights at which the glass-based articles failed on both 180-grit sandpaper and 30-grit sandpaper are plotted in Figure 35. As shown in Figure 35, all but three glass-based articles of Example 10A survived drops onto 180-grit sandpaper up to a height of approximately 225 cm (resulting in an average surviving drop height of approximately 215 cm). The average surviving drop height on 30-grit sandpaper was 132 cm.

[0194] The glass-based article according to Example 10A exhibited a dielectric constant of about 5.8 to about 6 over a frequency range of about 480 mHz to about 3000 mHz. The glass-based article according to Example 10A exhibited a dielectric loss tangent in the range of about 0.010 to about 0.013 over a frequency range of about 480 mHz to about 3000 mHz.

[0195] The refractive index of the glass-based article according to Example 10A is in the range of about 1.496 to about 1.523 over the wavelength range of about 380 nm to about 1550 nm, and in the range of about 1.496 to about 1.503 over the wavelength range of about 380 nm to about 800 nm.

[0196] The glass-based article according to Example 10A was subjected to various chemical treatments as shown in Table 10. The chemical durability of the glass-based article was compared with Comparative Examples 10B, 10C, and 10D. Comparative Example 10B was a glass substrate with a nominal composition of 64.3 mol% SiO, 7.02 mol% B2O, 14 mol% Al2O, 14 mol% Na2O, 0.5 mol% K2O, 0.03 mol% Fe2O, and 0.1 mol% SnO. Comparative Example 10C was a glass substrate with a nominal composition of 64.75 mol% SiO, 5 mol% B2O, 14 mol% Al2O, 13.75 mol% Na2O, 2.4 mol% MgO, and 0.08 mol% SnO. Comparative Example 10D was a glass substrate with a nominal composition of 57.5 mol % SiO2, 16.5 mol % Al2O3, 16.71 mol % Na2O, 2.8 mol % MgO, 0.05 mol % SnO2, and 6.5 mol % P2O5.

[0197] [Table 10]

[0198] Example 11 Example 11A included a 0.8 mm thick glass substrate having the same composition as Example 1. Comparative Example 11B included a 0.8 mm thick glass substrate having the same composition as Comparative Example 10D. The glass substrate of Example 11A was chemically strengthened in a single step using a single bath as described in Table 11. The glass substrate of Comparative Example 3B was ion-exchanged in a two-step process as described in Table 11.

[0199] [Table 11]

[0200] The glass-based articles of Example 11A and Comparative Example 11B were incorporated into identical mobile phone devices. The phone devices were dropped onto 30-grit sandpaper from increasing heights, starting at 20 centimeters. The heights at which the glass-based articles exhibited defects on the 30-grit sandpaper are plotted in Figure 36. As shown in Figure 36, the glass-based article of Example 11A exhibited an average remaining drop height (i.e., 127 cm) that was more than three times the average remaining drop height of Comparative Example 11B (i.e., 38 cm).

[0201] The glass-based articles of Example 11A and Comparative Example 11B were subjected to the AROR test described herein using a load or pressure of 25 psi. As shown in FIG. 37, the glass-based substrate of Example 10A exhibited an average failure load of approximately 31.3 kgf, while the glass-based substrate of Comparative Example 10B exhibited an average failure load of approximately 27.4 kgf. When the abrasion load or pressure was increased to 45 psi, the difference in average failure load between Example 10A and Comparative Example 10B increased. Specifically, as shown in FIG. 38, under a load or pressure of 45 psi, Example 10A exhibited an average failure load of approximately 28.9 kgf, while Comparative Example 10B exhibited an average failure load of approximately 19.6 kgf.

[0202] Example 12 Examples 12A and 12B included glass substrates having the same nominal composition as in Example 1H and a thickness of 0.8 mm. The glass substrate of Example 12A was chemically tempered in a bath containing 6.5% Na:93.5% K at 430°C for 4.5 hours to obtain a CS of about 656, a DOL of about 8.1, and a CS (or compressive stress at the knee) of about 105 to about 130 MPa. The substrate of Example 12B was chemically tempered in a bath containing 7% Na:93% K at 430°C for 4.5 hours to obtain a CS of about 640 MPa, a DOL of about 8.2, and a CS of about 100 MPa. Examples 12A and 12B were subjected to inverted ball drop-on-sandpaper (IBoS) testing according to the procedure described herein. Testing was performed using 30-grit sandpaper and a 4.2 g stainless steel ball with a diameter of 10 mm.

[0203] [Table 12]

[0204] Sample set 12A exhibited an average failure height of 88 cm. Additionally, four of the five samples survived drop heights of 75 cm, 80 cm, 85 cm, 90 cm, and 95 cm, respectively, resulting in an 80% survival rate at each of these heights. Sample set 12B exhibited an average failure height of 76 cm. Additionally, three of the five samples survived drop heights of 75 cm, 80 cm, and 85 cm, resulting in a 60% survival rate at each of these heights.

[0205] Sample sets 12A and 12B were also subjected to the Knoop scratch threshold test described above. Sample set 12A had a Knoop scratch threshold greater than 7 N and less than 14 N, while sample set 12B had a Knoop scratch threshold greater than 10 N and less than 16 N.

[0206] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the present invention. For example, various features can be combined according to the following exemplary embodiments.

[0207] Embodiment 1 a first surface defining a thickness (t) and a second surface defining an area (in square inches) opposite the first surface; having a non-zero concentration of metal oxide that varies along a thickness range of about 0·t to about 0.3·t; A glass-based article having a central tension (CT) region with a maximum CT of 71.5 / √(t) to 100 / √(t), A glass-based article such that, when a sample having dimensions of 5.08 cm x 5.08 cm (2 inches x 2 inches) is broken, the glass-based article breaks into more than 2 pieces / inch2 of the glass-based article.

[0208] Embodiment 2 2. The glass-based article of claim 1, wherein the concentration of metal oxide is non-zero and varies along the entire thickness.

[0209] Embodiment 3 3. The glass-based article of claim 1 or 2, wherein the monovalent ions of the metal oxide generate stress along the thickness range.

[0210] Embodiment 4 10. The glass-based article of any one of the preceding embodiments, wherein the concentration of metal oxide decreases from the first surface to a value at a point between the first surface and the second surface, and increases from that value to the second surface.

[0211] Embodiment 5 10. The glass-based article of any one of the preceding embodiments, further comprising a surface compressive stress (CS) of about 300 MPa or greater.

[0212] EMBODIMENT 6 6. The glass-based article of claim 5, wherein the surface Cs is greater than or equal to about 400 MPa.

[0213] EMBODIMENT 7 10. The glass-based article of any one of the preceding embodiments, wherein the concentration of metal oxide is greater than or equal to about 0.05 mol % throughout the thickness.

[0214] EMBODIMENT 8 10. The glass-based article of any one of the preceding embodiments, wherein the concentration of metal oxide at the first surface is about 1.5 times greater than the concentration of metal oxide at a depth corresponding to about 0.5 t.

[0215] EMBODIMENT 9 10. The glass-based article of any one of the preceding embodiments, wherein the glass-based article comprises a total concentration of metal oxides in the range of about 1 mol % to about 15 mol %.

[0216] EMBODIMENT 10 2. The glass-based article of any one of the preceding embodiments, wherein the metal oxides comprise any one or more of Li2O, Na2O, K2O, Rb2O, and Cs2O.

[0217] EMBODIMENT 11 10. The glass-based article of any one of the preceding embodiments, further comprising a surface C S of about 200 MPa or greater and a chemical depth of layer of about 0.4·t or greater.

[0218] EMBODIMENT 12 10. The glass-based article of any one of the preceding embodiments, further comprising a CS extending from the first surface to the DOC, wherein the DOC is about 0.1 t or greater.

[0219] EMBODIMENT 13 10. The glass-based article of any one of the preceding embodiments, wherein the CT region comprises a metal oxide.

[0220] EMBODIMENT 14 12. The glass-based article of embodiment 11, wherein the ratio of maximum CT to the absolute value of surface CS is in the range of about 0.1 to about 0.8.

[0221] EMBODIMENT 15 10. The glass-based article of any one of the preceding embodiments, wherein t comprises about 3 millimeters or less.

[0222] EMBODIMENT 16 10. The glass-based article of any one of the preceding embodiments, further comprising an amorphous structure.

[0223] EMBODIMENT 17 16. The glass-based article of any one of embodiments 1 to 15, further comprising a crystalline structure.

[0224] EMBODIMENT 18 The glass-based article of any one of the preceding embodiments, further exhibiting a transmittance of about 88% or greater over a wavelength range of about 380 nm to about 780 nm.

[0225] EMBODIMENT 19 10. The glass-based article of any one of the preceding embodiments, further exhibiting CIELAB color space coordinates under CIE illuminant F02 of an L* value of about 88 or greater, an a* value within the range of about −3 to about +3, and a b* value within the range of about −6 to about +6.

[0226] EMBODIMENT 20 further comprising a first metal oxide concentration and a second metal oxide concentration; the first metal oxide concentration is in the range of about 0 mol % to about 15 mol % from a first thickness range of about 0·t to about 0.5·t; the second metal oxide concentration is in the range of about 0 mol % to about 10 mol % from a second thickness range of about 0 micrometers to about 25 micrometers; 10. The glass-based article of any one of the preceding embodiments.

[0227] EMBODIMENT 21 21. The glass-based article of claim 20, further comprising a third metal oxide.

[0228] EMBODIMENT 22 10. The glass-based article of any one of the preceding embodiments, further having a Young's modulus of about 70 GPa or greater.

[0229] EMBODIMENT 23 10. The glass-based article of any one of the preceding embodiments, further comprising a liquidus viscosity of less than about 100 kilopoise (kP).

[0230] EMBODIMENT 24 moreover, a composition having a combined amount of Al2O3 and Na2O of about 17 mol% or less; a composition comprising about 4 mol% or less NaO; A composition comprising one or more of B2O3 and ZnO, and Compositions substantially free of P2O5 10. The glass-based article of any one of the preceding embodiments, comprising any one or more of:

[0231] EMBODIMENT 25 a housing having a front surface, a back surface, and a side surface; an electrical component at least partially inside the housing; a display at or near the front of the housing; a cover substrate disposed over the display, 25. A device wherein the cover substrate comprises the glass-based article of any one of embodiments 1 to 24.

[0232] EMBODIMENT 26 1. A glass-based article comprising a first surface defining a thickness (t) of about 3 millimeters or less and a second surface opposite the first surface, the glass-based article having a stress profile extending through the thickness, the stress profile extending through the thickness comprising: all points of the stress profile between thickness ranges of about 0·t to 0.3·t and greater than 0.7·t have a tangent with a slope of an absolute value greater than about 0.1 MPa / micrometer; the stress profile has a maximum CS, DOC, and a maximum CT in the range of about 71.5 / √(t) to about 100 / √(t), and the ratio of the maximum CT to the absolute value of the maximum CS is in the range of about 0.01 to about 0.2; DOC is approximately 0.1·t or more, A glass-based article such that when a sample having dimensions of 5.08 cm x 5.08 cm (2 inches x 2 inches) is broken, the glass-based article breaks into at least two pieces per square inch.

[0233] EMBODIMENT 27 27. The glass-based article of claim 26, further having a surface CS of about 300 MPa or greater.

[0234] EMBODIMENT 28 28. The glass-based article of claim 26 or 27, further having a surface Cs of about 200 MPa or greater and a chemical depth of layer of about 0.4·t or greater.

[0235] EMBODIMENT 29 29. The glass-based article of any one of embodiments 26-28, further comprising a CS layer extending from the first surface to the DOC, wherein the DOC is about 0.1·t or greater.

[0236] EMBODIMENT 30 30. The glass-based article of any one of embodiments 26-29, further comprising a CT region, the CT region having a non-zero and varying metal oxide concentration.

[0237] EMBODIMENT 31 31. The glass-based article of any one of embodiments 26-30, further having a ratio of maximum CT to absolute value of surface CS in the range of about 0.1 to about 0.8.

[0238] EMBODIMENT 32 32. The glass-based article according to any one of embodiments 26 to 31, further having a Young's modulus of 70 GPa or more.

[0239] EMBODIMENT 33 33. The glass-based article of any one of embodiments 26-32, further having a liquidus viscosity of less than about 100 kP.

[0240] EMBODIMENT 34 moreover, a composition having a combined amount of Al2O3 and Na2O of about 17 mol% or less; a composition comprising about 4 mol% or less NaO; A composition comprising one or more of B2O3 and ZnO, and Compositions substantially free of P2O5 34. The glass-based article of any one of embodiments 26 to 33, comprising any one or more of:

[0241] EMBODIMENT 35 a housing having a front surface, a back surface, and a side surface; an electrical component at least partially inside the housing; a display at or near the front of the housing; a cover substrate disposed over the display, A device wherein the cover substrate comprises the glass-based article of any one of embodiments 26 to 34.

[0242] EMBODIMENT 36 a first surface defining a thickness (t) and a second surface opposite the first surface; having a non-zero concentration of metal oxide that varies along a thickness range of about 0·t to about 0.3·t; It has a surface compressive stress of approximately 200 MPa or more, A glass-based article having a CT region with a maximum CT in the range of about 71.5 / √(t) to about 100 / √(t).

[0243] EMBODIMENT 37 37. The glass-based article of embodiment 36, wherein the thickness range of metal oxide concentration is from about 0·t to about 0.4·t.

[0244] EMBODIMENT 38 38. The glass-based article of embodiment 36 or 37, wherein the thickness range of metal oxide concentration is from about 0·t to about 0.45·t.

[0245] EMBODIMENT 39 39. The glass-based article of any one of embodiments 36-38, wherein the monovalent ions of the metal oxide create stress along the thickness range.

[0246] EMBODIMENT 40 40. The glass-based article of claim 39, wherein the monovalent ion of the metal oxide has the largest ionic diameter of all monovalent ions of metal oxides in the glass-based substrate.

[0247] EMBODIMENT 41 41. The glass-based article of any one of embodiments 36-40, wherein the concentration of metal oxide decreases from the first surface to a value at a point between the first surface and the second surface, and increases from that value to the second surface.

[0248] EMBODIMENT 42 42. The glass-based article of any one of claims 36-41, wherein when the glass-based article is broken using a sample having dimensions of 5.08 cm by 5.08 cm (2 inches by 2 inches) square, the glass-based article breaks into at least 1 fragment per inch and up to 40 fragments per inch.

[0249] EMBODIMENT 43 Glass-based products are approximately 450 μm at approximately 460°C. 2 / hr or more and a DOC greater than about 0.15 t, and the surface CS is 1.5 times or more the maximum CT.

[0250] EMBODIMENT 44 Glass-based products have a resistance of approximately 0.65 MPa·m 1 / 2 44. The glass-based article according to any one of embodiments 36 to 43, having a fracture toughness (K1C) of at least 100%.

[0251] EMBODIMENT 45 45. The glass-based article of any one of embodiments 36 to 44, wherein the surface CS is greater than the maximum CT.

[0252] EMBODIMENT 46 46. ​​The glass-based article of any one of embodiments 36-45, having a surface CS of about 300 MPa or more and a thickness of about 2 millimeters or less.

[0253] EMBODIMENT 47 47. The glass-based article of any one of embodiments 36-46, wherein the concentration of metal oxide is greater than or equal to about 0.05 mol % throughout the thickness.

[0254] EMBODIMENT 48 48. The glass-based article of any one of embodiments 36-47, wherein the concentration of metal oxide at the first surface is about 1.5 times greater than the concentration of metal oxide at a depth corresponding to about 0.5·t.

[0255] EMBODIMENT 49 49. The glass-based article of any one of embodiments 36-48, wherein the total concentration of metal oxides is in the range of about 1 mol % to about 15 mol %.

[0256] EMBODIMENT 50 50. The glass-based article of any one of embodiments 36-49, further having a chemical depth of layer of about 0.4·t or greater.

[0257] EMBODIMENT 51 51. The glass-based article of any one of embodiments 36-50, further comprising a CS layer extending from the first surface to the DOC, wherein the DOC is about 0.1·t or greater.

[0258] EMBODIMENT 52 52. The glass-based article of any one of embodiments 36-51, wherein the CT region comprises a metal oxide.

[0259] EMBODIMENT 53 53. The glass-based article of any one of embodiments 36-52, wherein the ratio of maximum CT to the absolute value of surface CS is in the range of about 0.1 to about 0.8.

[0260] EMBODIMENT 54 54. The glass-based article of any one of embodiments 36-53, wherein t comprises about 3 millimeters or less.

[0261] EMBODIMENT 55 55. The glass-based article of any one of embodiments 36 to 54, further having a Young's modulus of about 70 GPa or greater.

[0262] EMBODIMENT 56 56. The glass-based article of any one of embodiments 36 to 55, further having a liquidus viscosity of less than about 100 kP.

[0263] EMBODIMENT 57 moreover, a composition having a combined amount of Al2O3 and Na2O of about 17 mol% or less; a composition comprising about 4 mol% or less NaO; A composition comprising one or more of B2O3 and ZnO, and Compositions substantially free of P2O5 57. The glass-based article of any one of embodiments 36 to 56, comprising any one or more of:

[0264] EMBODIMENT 58 a housing having a front surface, a back surface, and a side surface; an electrical component at least partially inside the housing; a display at or near the front of the housing; A device comprising a cover substrate disposed on a display, the cover substrate comprising the glass-based article of any one of embodiments 36 to 57.

[0265] EMBODIMENT 59 1. A glass-based article comprising a first surface defining a thickness (t) and a second surface opposite the first surface, the glass-based article comprising metal oxides forming a concentration gradient, the concentration of the metal oxide decreases from the first surface to a value at a point between the first surface and the second surface and increases from that value to the second surface; The concentration of the metal oxide at that point is not zero, Glass-based products are approximately 0 J / m 2 More than 20J / m 2 A glass-based article having a stored tensile energy of less than about 70 GPa and a Young's modulus of about 70 GPa or greater.

[0266] EMBODIMENT 60 60. The glass-based article of claim 59, further having a surface CS of about 300 MPa or greater.

[0267] EMBODIMENT 61 61. The glass-based article of embodiment 59 or 60, wherein the concentration of metal oxide is greater than or equal to about 0.05 mol% throughout the thickness.

[0268] EMBODIMENT 62 62. The glass-based article of any one of embodiments 59-61, wherein the concentration of metal oxide at the first surface is about 1.5 times greater than the concentration of metal oxide at a depth corresponding to about 0.5·t.

[0269] 63. 63. The glass-based article of any one of embodiments 59-62, wherein the total concentration of metal oxides is in the range of about 1 mol % to about 15 mol %.

[0270] 64th embodiment 64. The glass-based article of any one of embodiments 59-63, wherein the metal oxide comprises any one or more of Li2O, Na2O, K2O, Rb2O, and Cs2O.

[0271] EMBODIMENT 65 65. The glass-based article of any one of embodiments 59-64, further comprising a CS layer extending from the first surface to the DOC, wherein the DOC is about 0.1·t or greater.

[0272] 66. The method of claim 66, 66. The glass-based article of any one of embodiments 59 to 65, further comprising a CT region having a metal oxide concentration gradient.

[0273] 67. The method of claim 67, 67. The glass-based article of embodiment 66, wherein the CT region has a maximum CT, and the ratio of maximum CT to the absolute value of the surface CS is in the range of about 0.1 to about 0.8.

[0274] 68. The method of claim 68, 68. The glass-based article of any one of embodiments 59-67, wherein t comprises about 3 millimeters or less.

[0275] 69. The method of claim 69, 68. The glass-based article of embodiment 67, wherein the maximum CT is in the range of about 71.5 / √(t) to about 100 / √(t).

[0276] EMBODIMENT 70 70. The glass-based article of any one of embodiments 59-69, further having a liquidus viscosity of less than about 100 kP.

[0277] EMBODIMENT 71 moreover, a composition having a combined amount of Al2O3 and Na2O of about 17 mol% or less; a composition comprising about 4 mol% or less NaO; A composition comprising one or more of B2O3 and ZnO, and Compositions substantially free of P2O5 71. The glass-based article of any one of embodiments 59 to 70, comprising any one or more of:

[0278] EMBODIMENT 72 a housing having a front surface, a back surface, and a side surface; an electrical component at least partially inside the housing; a display at or near the front of the housing; A device comprising a cover substrate disposed on a display, the cover substrate comprising the glass-based article of any one of embodiments 59 to 71.

[0279] EMBODIMENT 73 1. A glass-based article comprising: a first surface defining a thickness (t) of about 3 millimeters or less; and a second surface opposite the first surface; the glass-based article having a stress profile extending through the thickness; the stress profile at all points between about 0·t and 0.3·t and greater than 0.7·t has a tangent with a slope of an absolute value greater than about 0.1 MPa / micrometer; The stress profile has maximum CS, DOC and maximum CT, The ratio of the maximum CT to the absolute value of the maximum CS is within the range of about 0.01 to about 0.2, and the DOC is about 0.1 t or more. Glass-based products are approximately 0 J / m 2 More than 20J / m 2A glass-based article having a stored tensile energy of less than about 70 GPa and a Young's modulus of about 70 GPa or greater.

[0280] EMBODIMENT 74 74. The glass-based article of embodiment 73, further comprising a non-zero concentration of metal oxide that varies continuously throughout its thickness.

[0281] EMBODIMENT 75 75. The glass-based article of claim 73 or 74, further comprising a non-zero concentration of metal oxide that varies continuously along a thickness of less than about 10 micrometers.

[0282] EMBODIMENT 76 76. The glass-based article of any one of embodiments 73-75, comprising a maximum CS of about 300 MPa or greater.

[0283] EMBODIMENT 77 77. The glass-based article of any one of embodiments 73-76, further having a chemical depth of layer of about 0.4·t or greater.

[0284] EMBODIMENT 78 78. The glass-based article of any one of embodiments 73 to 77, further comprising a CT region having a metal oxide concentration gradient.

[0285] EMBODIMENT 79 79. The glass-based article of any one of embodiments 73-78, wherein t comprises about 3 millimeters or less.

[0286] EMBODIMENT 80 80. The glass-based article of any one of embodiments 73 to 79, wherein the maximum CT is 71.5 / √(t) or greater.

[0287] EMBODIMENT 81 81. The glass-based article of any one of embodiments 73 to 80, further having a liquidus viscosity of less than about 100 kP.

[0288] EMBODIMENT 82 moreover, a composition having a combined amount of Al2O3 and Na2O of about 17 mol% or less; a composition comprising about 4 mol% or less NaO; A composition comprising one or more of B2O3 and ZnO, and Compositions substantially free of P2O5 82. The glass-based article of any one of embodiments 73 to 81, comprising any one or more of:

[0289] 83rd Embodiment a housing having a front surface, a back surface, and a side surface; an electrical component at least partially inside the housing; a display at or near the front of the housing; A device comprising a cover substrate disposed on a display, the cover substrate comprising the glass-based article of any one of embodiments 73 to 82.

[0290] 84th embodiment 1. A glass-based article having a stress profile comprising a CS region and a CT region, wherein the CT region has a stress profile defined by the formula: Stress (x)=MaxT-(((CTn·(n+1)) / 0.5n)·|(x / t)-0.5|n) where MaxT is the maximum tensile value, CTn is a positive value in MPa less than or equal to MaxT, x is the position along the thickness (t) in micrometers, and n is between 1.5 and 5. Glass-based articles, estimated by:

[0291] EMBODIMENT 85 85. The glass-based article of embodiment 84, wherein the CT region has a maximum CT value in the range of about 50 MPa to about 250 MPa, the maximum CT value being at a depth in the range of about 0.4·t to about 0.6t.

[0292] 86. The method of claim 85, 86. The glass-based article of claim 84 or 85, wherein the stress profile has a slope in the range of about 20 MPa / micrometer to about 200 MPa / micrometer from a thickness in the range of about 0·t to about 0.1·t micrometers.

[0293] EMBODIMENT 87 87. The glass-based article of any one of embodiments 84 to 86, wherein the stress profile is approximated by a plurality of error functions measured at the 0.5·t~ surface.

[0294] User 88 Use of a glass substrate in a tempered glass-based article, the glass substrate comprising (mol %): SiO2 in an amount ranging from about 68 to about 75; Al2O3 in an amount ranging from about 10 to about 15; B2O3 in an amount ranging from about 0.5 to about 5; Li2O in an amount ranging from about 2 to about 10; Na2O in an amount ranging from about 0 to about 6; MgO in an amount ranging from about 1 to about 4; ZnO in an amount ranging from about 0 to about 3, and containing CaO in an amount ranging from about 0 to about 5; The glass substrate is ion-exchangeable and amorphous, The glass substrate is a ratio of Li2O to R2O in the range of about 0.45 to about 1; a difference between the total amount of R2O and the amount of Al2O3 in the range of about -5 to about 0; the difference between the total amount of RxO (mol %) and the amount of Al2O3 in the range of about 0 to about 3; and The ratio of the amount of MgO (mol %) to the total amount of RO (mol %) is in the range of about 0 to about 1. Show one or more of the following: The glass substrate is substantially free of nucleating agents.

[0295] EMBODIMENT 89 In mole %, SiO2 in an amount ranging from about 68 to about 75; Al2O3 in an amount ranging from about 10 to about 15; B2O3 in an amount ranging from about 0.5 to about 5; Li2O in an amount ranging from about 2 to about 10; Na2O in an amount ranging from about 0 to about 6; MgO in an amount ranging from about 1 to about 4; ZnO in an amount ranging from about 0 to about 3, and CaO in an amount ranging from about 0 to about 5 A glass substrate having a composition comprising: The glass substrate is ion-exchangeable and amorphous, The glass substrate is a ratio of LiO to R2O ranging from about 0.45 to about 1; a difference between the total amount of R2O and the amount of Al2O3 in the range of about -5 to about 0; the difference between the total amount of RxO (mol %) and the amount of Al2O3 in the range of about 0 to about 3; and The ratio of the amount of MgO (mol %) to the total amount of RO (mol %) is in the range of about 0 to about 1. Show one or more of the following: A glass substrate, wherein the glass substrate is substantially free of a nucleating agent.

[0296] EMBODIMENT 90 In mole %, SiO2 in an amount ranging from about 68 to about 75; Al2O3 in an amount ranging from about 10 to about 15; B2O3 in an amount ranging from about 0.5 to about 5; Li2O in an amount ranging from about 2 to about 10; Na2O in an amount ranging from about 0 to about 6; MgO in an amount ranging from about 1 to about 4; ZnO in an amount ranging from about 0 to about 3, and CaO in an amount ranging from about 0 to about 5 A glass substrate having a composition comprising: The glass substrate is amorphous and strengthened, The glass substrates have varying Na2O concentrations, and the glass substrates are substantially free of nucleating agents.

[0297] EMBODIMENT 91 moreover, a ratio of Li2O to R2O in the range of about 0.45 to about 1; a difference between the total amount of R2O and the amount of Al2O3 in the range of about -5 to about 0; the difference between the total amount of RxO (mol %) and the amount of Al2O3 in the range of about 0 to about 3; and The ratio of the amount of MgO (mol %) to the total amount of RO (mol %) is in the range of about 0 to about 1. 91. The glass substrate of embodiment 90, wherein the glass substrate exhibits one or more of the following:

[0298] EMBODIMENT 92 89. The glass-based article of any one of embodiments 1-88, wherein at least one of the first surface and the second surface has a Knoop scratch threshold of greater than 7N.

[0299] EMBODIMENT 93 93. The glass-based article of any one of embodiments 1-88 and 92, wherein at least one of the first surface and the second surface has a Knoop scratch threshold of less than 14 N.

[0300] EMBODIMENT 94 94. The glass-based article of any one of embodiments 1-88 and 92-93, wherein the tempered glass-based substrate has one of (i) at least 60% survival or (ii) at least 80% survival when subjected to an inverted ball drop test using a 4.2 g stainless steel ball having a 10 mm diameter from one of the following heights onto 30 grit sandpaper placed on the surface of the glass to leave a 100 μm gap between the sandpaper and the surface of the glass, the survival rate being based on testing of at least five samples.

[0301] EMBODIMENT 95 95. The glass-based article of any one of claims 1-88 and 92-94, wherein the tempered glass-based substrate has an average defect height of one of (i) greater than 70 cm, (ii) greater than 75 cm, (iii) greater than 80 cm, and (iv) greater than 85 cm when subjected to an inverted ball drop test using a 4.2 g stainless steel ball having a diameter of 10 mm on 30 grit sandpaper placed on the surface of the glass such that a 100 μm air gap is formed between the sandpaper and the surface of the glass, and wherein the survival rate is based on testing of at least five samples.

[0302] Preferred embodiments of the present invention will be described below in detail.

[0303] Embodiment 1 a first surface defining a thickness (t) and a second surface opposite the first surface; having a non-zero concentration of metal oxide that varies along a thickness range of about 0·t to about 0.3·t; It has a surface compressive stress of approximately 200 MPa or more, A glass-based article having a CT region with a maximum CT in the range of about 71.5 / √(t) to about 100 / √(t).

[0304] Embodiment 2 2. The glass-based article of embodiment 1, wherein the thickness range of metal oxide concentration is from about 0·t to about 0.4·t.

[0305] Embodiment 3 3. The glass-based article of embodiment 1 or 2, wherein the thickness range of metal oxide concentration is from about 0·t to about 0.45·t.

[0306] Embodiment 4 4. The glass-based article of any one of embodiments 1-3, wherein the monovalent ions of the metal oxide generate stress along the thickness range.

[0307] Embodiment 5 5. The glass-based article of embodiment 4, wherein the monovalent ions of the metal oxide have the largest ion diameter of all monovalent ions of the metal oxide in the glass-based substrate.

[0308] Embodiment 6 6. The glass-based article of any one of embodiments 1-5, wherein the concentration of metal oxide decreases from the first surface to a value at a point between the first surface and the second surface, and increases from that value to the second surface.

[0309] Embodiment 7 7. The glass-based article of any one of embodiments 1 to 6, wherein when a sample having dimensions of 5.08 cm x 5.08 cm square is broken, the glass-based article breaks into at least 1 fragment / inch and up to 40 fragments / inch.

[0310] Embodiment 8 Glass-based products are approximately 450 μm at approximately 460°C. 2 / hr or more and a DOC greater than about 0.15·t, and a surface CS greater than or equal to 1.5 times the maximum CT.

[0311] Embodiment 9 Glass-based products have a resistance of approximately 0.65 MPa·m 1 / 2 9. The glass-based article according to any one of embodiments 1 to 8, having a fracture toughness (K1C) of at least 100%.

[0312] Embodiment 10 10. The glass-based article of any one of embodiments 1-9, wherein the surface CS is greater than the maximum CT.

[0313] Embodiment 11 11. The glass-based article of any one of embodiments 1-10, wherein the surface CS is about 300 MPa or more and the thickness is about 2 millimeters or less.

[0314] Embodiment 12 12. The glass-based article of any one of embodiments 1-11, wherein the concentration of metal oxide is greater than or equal to about 0.05 mol % throughout the thickness.

[0315] Embodiment 13 13. The glass-based article of any one of embodiments 1-12, wherein the concentration of metal oxide at the first surface is about 1.5 times greater than the concentration of metal oxide at a depth corresponding to about 0.5·t.

[0316] Embodiment 14 14. The glass-based article of any one of embodiments 1 to 13, wherein the total concentration of metal oxides is in the range of about 1 mol % to about 15 mol %.

[0317] Embodiment 15 15. The glass-based article of any one of embodiments 1-14, further having a chemical depth of layer of about 0.4·t or greater.

[0318] Embodiment 16 16. The glass-based article of any one of embodiments 1-15, further comprising a CS layer extending from the first surface to the DOC, wherein the DOC is about 0.1·t or greater.

[0319] Embodiment 17 17. The glass-based article of any one of embodiments 1-16, wherein the CT region comprises a metal oxide.

[0320] Embodiment 18 18. The glass-based article of any one of embodiments 1-17, wherein the ratio of maximum CT to the absolute value of surface CS is in the range of about 0.1 to about 0.8.

[0321] Embodiment 19 19. The glass-based article of any one of claims 1-18, wherein t comprises about 3 millimeters or less.

[0322] Embodiment 20 20. The glass-based article according to any one of embodiments 1 to 19, further having a Young's modulus of about 70 GPa or more.

[0323] Embodiment 21 21. The glass-based article of any one of embodiments 1-20, further having a liquidus viscosity of less than about 100 kP.

[0324] Embodiment 22 moreover, a composition having a combined amount of Al2O3 and Na2O of about 17 mol% or less; a composition comprising about 4 mol% or less NaO; A composition comprising one or more of B2O3 and ZnO, and Compositions substantially free of P2O5 22. The glass-based article of any one of embodiments 1 to 21, comprising any one or more of:

[0325] Embodiment 23 a housing having a front surface, a back surface, and a side surface; an electrical component at least partially inside the housing; a display at or near the front of the housing; A device comprising a display and a cover substrate disposed on the display, the cover substrate comprising the glass-based article of any one of embodiments 1 to 22.

[0326] Embodiment 24 1. A glass-based article comprising: a first surface defining a thickness (t) of about 3 millimeters or less; and a second surface opposite the first surface; the glass-based article having a stress profile extending through the thickness; the stress profile at all points between about 0·t and 0.3·t and greater than 0.7·t has a tangent with a slope of an absolute value greater than about 0.1 MPa / micrometer; the stress profile has a maximum CS, a DOC, and a maximum CT, the ratio of the maximum CT to the absolute value of the maximum CS is within the range of about 0.01 to about 0.2, and the DOC is about 0.1 t or more; Glass-based products are approximately 0 J / m 2 More than 20J / m 2A glass-based article having a stored tensile energy of less than about 70 GPa and a Young's modulus of about 70 GPa or greater.

[0327] Embodiment 25 25. The glass-based article of embodiment 24, further comprising a non-zero concentration of metal oxide that varies continuously along the entire thickness.

[0328] Embodiment 26 26. The glass-based article of claim 24 or 25, further comprising a non-zero concentration of metal oxide that varies continuously along a thickness of less than about 10 micrometers.

[0329] Embodiment 27 27. The glass-based article of any one of embodiments 24-26, comprising a maximum CS of about 300 MPa or greater.

[0330] Embodiment 28 28. The glass-based article of any one of embodiments 24-27, further having a chemical depth of layer of about 0.4·t or greater.

[0331] Embodiment 29 29. The glass-based article of any one of embodiments 24 to 28, further comprising a CT region having a metal oxide concentration gradient.

[0332] Embodiment 30 30. The glass-based article of any one of claims 24-29, wherein t comprises about 3 millimeters or less.

[0333] Embodiment 31 31. The glass-based article of any one of embodiments 24 to 30, wherein the maximum CT is 71.5 / √(t) or greater.

[0334] Embodiment 32 32. The glass-based article of any one of embodiments 24-31, further having a liquidus viscosity of less than about 100 kP.

[0335] Embodiment 33 moreover, a composition having a combined amount of Al2O3 and Na2O of about 17 mol% or less; a composition comprising about 4 mol% or less NaO; A composition comprising one or more of B2O3 and ZnO, and Compositions substantially free of P2O5 33. The glass-based article of any one of embodiments 24 to 32, comprising any one or more of:

[0336] Embodiment 34 a housing having a front surface, a back surface, and a side surface; an electrical component at least partially inside the housing; a display at or near the front of the housing; A device comprising a cover substrate disposed on a display, the cover substrate comprising the glass-based article of any one of embodiments 24 to 33.

[0337] Embodiment 35 35. The glass-based article of any one of embodiments 1-34, wherein at least one of the first surface and the second surface has a Knoop scratch threshold of greater than 7N.

[0338] Embodiment 36 36. The glass-based article of any one of embodiments 1-35, wherein at least one of the first surface and the second surface has a Knoop scratch threshold of less than 14 N.

[0339] Embodiment 37 37. The glass-based article of any one of claims 1 to 36, wherein the tempered glass-based substrate has either (i) at least 60% survival rate or (ii) at least 80% survival rate when subjected to an inverted ball drop test using a 4.2 g stainless steel ball having a diameter of 10 mm from a height of one of (i) about 80 cm, (ii) about 88 cm, (iii) about 90 cm, and (iv) about 95 cm onto 30 grit sandpaper placed on the surface of the glass such that a gap of 100 μm is formed between the sandpaper and the surface of the glass, the survival rate being based on testing of at least five samples. Embodiment 38 38. The glass-based article of any one of claims 1-37, wherein the tempered glass-based substrate has an average defect height of one of (i) greater than 70 cm, (ii) greater than 75 cm, (iii) greater than 80 cm, and (iv) greater than 85 cm when subjected to an inverted ball drop test using a 4.2 g stainless steel ball having a diameter of 10 mm on 30 grit sandpaper placed on the surface of the glass such that a 100 μm air gap is formed between the sandpaper and the surface of the glass, and wherein the survival rate is based on testing of at least five samples. [Explanation of symbols]

[0340] 100 Glass items 101 First Surface 110 Surface CS 120 Central tension (CT) 130 Depth of Compression (DOC) 200 Glass products 201 First Surface 210 Surface CS 220 Max CT 230 DOC 300 Glass products 302 First Surface 304 Second Surface 310 Surface CS 312 Stress Profile 315 CS layer 317,327 depth or length 320 Max CT 325 CT layer 330 DOC 400 AROR configuration 410 Wear glass articles 430 Load Ring 420 Support Ring 430a surface 500 devices 510 Test Stand 512 Solid Base 514 seats 515 Sample Holder 516 void 518 Glass products 520 adhesive tape 530 balls 1000 electronic equipment 1020 Housing 1040 Front 1060 Back 1080 Side 1120 Display

Claims

1. 45 mol % or more and 75 mol % or less of SiO ２ and, 5 mol % or more and 20 mol % or less of Al ２ O ３ and, 0.1 mol % or more and 6 mol % or less of B ２ O ３ and, 1 mol% or more and 8 mol% or less of Na ２ O and 2 mol% or more and 10 mol% or less of Li ２ O and Less than 3 mol% K ２ O and up to 8 mol % of an alkaline earth metal oxide; Less than 1 mol% ZrO ２ and, A glass-based article comprising: Li in the glass-based article ２ O, Na ２ O and K ２ The sum of O is R ２ When the Li content in the glass-based article is O, ２ O (mol%) to R ２ O (mol%) is greater than 0.5, and R ２ The total amount of O is 5 mol% or more and 15 mol% or less. Glass-based items.

2. 0 mol% or more and 5 mol% or less of MgO; ZnO of 0 mol% or more and 2 mol% or less 10. The glass-based article of claim 1, comprising:

3. 0.1 mol% or more and 4 mol% or less of B ２ O ３ and, 1 mol% or more and 4 mol% or less of Na ２ O and 6 mol% or more and 10 mol% or less of Li ２ O and Less than 1 mol% K ２ O and up to 5 mol % of an alkaline earth metal oxide; Less than 0.5 mol% ZrO ２ and, 10. The glass-based article of claim 1, comprising:

4. TiO ２ and Fe ２ O ３ 10. The glass-based article of claim 1, wherein the glass-based article is substantially free of:

5. 0 mol % or more and 4 mol % or less of P ２ O ５ 10. The glass-based article of claim 1, comprising:

6. Li in the glass-based article ２ O (mol%) to R ２ 2. The glass-based article of claim 1, wherein the ratio of O (mol%) is greater than 0.

7.

7. 10. The glass-based article of claim 1, wherein the glass-based article is strengthened and has a surface compressive stress greater than 300 MPa.

8. 8. The glass-based article of claim 7, wherein the glass-based article has a thickness t and a compression depth of 0.1t or greater.

9. 10. The glass-based article of claim 1 having a Young's modulus of 70 GPa or greater.

10. 10. The glass-based article of claim 1 comprising a crystalline structure.

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