Glass and glass-ceramics comprising a concentration gradient of metal oxides

Abstract

An embodiment of a glass-based article is disclosed, the article comprising a first surface defining a thickness (t) of about 3 mm or less (e.g., about 1 mm or less) and a second surface opposite to the first surface, and a stress profile, wherein all points on the stress profile for thicknesses ranging from about 0.t to 0.3.t and greater than 0.7.t contain tangents less than about -0.1 MPa / μm or greater than about 0.1 MPa / μm. In some embodiments, the glass-based article comprises a non-zero metal oxide concentration varying along at least a portion of the thickness (e.g., 0.t to about 0.3.t). In some embodiments, the concentration of the metal oxide or alkali metal oxide decreases from the first surface to a location between the first and second surfaces, and increases from said location to the second surface. The metal oxide concentration throughout the thickness may be about 0.05 mol% or greater, or about 0.5 mol% or greater. Methods for forming these glass-based articles are also disclosed.

Description

[0001] This case is a divisional application of the patent application filed on October 8, 2015, with application number 2015800657548 and invention title "Glass and Glass-Ceramics Containing a Metal Oxide Concentration Gradient". Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application Serial No. 62 / 194967, filed July 21, 2015; U.S. Provisional Application Serial No. 62 / 171110, filed June 4, 2015; U.S. Provisional Application Serial No. 62 / 117585, filed February 18, 2015; and U.S. Provisional Application Serial No. 62 / 061372, filed October 8, 2014, the contents of which form the basis of this application and are incorporated herein by reference in their entirety. background This disclosure relates to glass-based articles exhibiting improved damage resistance, including improved fracture resistance, and more specifically, to glass and glass-ceramic articles exhibiting a non-zero metal oxide concentration gradient or a concentration that varies along most of the thickness.

[0003] Glass-based products frequently experience severe impacts that can introduce large defects into the surface. These defects can extend to a depth of no more than approximately 200 micrometers from the surface. Traditionally, heat-tempered glass is used to prevent defects from being introduced into the glass and causing failure, because heat-tempered glass often exhibits a large compressive stress (CS) layer (e.g., approximately 21% of the total glass thickness), which prevents defect propagation and subsequent failure. An example of a stress profile generated by heat tempering is shown below. Figure 1 . Figure 1 In the heat-treated glass substrate 100, there is a first surface 101, a thickness t1, and a surface CS110. The glass substrate 100 exhibits a CS that decreases from the first surface 101 as defined herein to a layer depth (DOL) 130, at which the stress changes from compressive stress to tensile stress and reaches the maximum central tension (CT) 120.

[0004] Heat tempering is currently limited to thicker glass-based products (i.e., glass-based products with a thickness t1 of approximately 3 mm or more) because a sufficient thermal gradient must be formed between the core and surface of these products to achieve heat strengthening and the required residual stress. These thicker products are undesirable and impractical in many applications, such as displays (e.g., consumer electronics, including mobile phones, tablets, computers, navigation systems, etc.), buildings (e.g., windows, shower enclosure panels, countertops, etc.), transportation vehicles (e.g., automobiles, trains, airplanes, ships, etc.), household appliances, or any thin and lightweight product requiring excellent fracture resistance.

[0005] Although chemical strengthening is not limited by the thickness of the glass substrate in the same way as thermal tempering, known chemically strengthened glass substrates do not exhibit the stress profiles of thermally tempered glass substrates. One example of a stress profile generated by chemical strengthening (e.g., through an ion exchange process) is shown below. Figure 2 . Figure 2 In this context, the chemically strengthened glass-based article 200 includes a first surface 201, a thickness t2, and a surface CS 210. The glass-based article 200 exhibits a CS that decreases from the first surface 201 as defined herein to a depth DOL 230, at which point the stress transitions from compressive stress to tensile stress and reaches a maximum CT 220. Figure 2 As shown, these curves exhibit flat CT regions or CT regions with constant or near-constant tensile stress, and often have a relative... Figure 1 The maximum CT value shown is lower than the maximum central value.

[0006] Therefore, there is a need for thin glass-based products that exhibit improved fracture resistance. Invention Overview A first aspect of this disclosure relates to a glass-based article comprising a first surface defining a thickness (t) (e.g., about 3 mm or less, 1 mm or less, or about 0.5 mm or less), a second surface opposite to the first surface, and a stress profile extending along the thickness. In one or more embodiments, all points on the stress profile with a thickness ranging from about 0.t to about 0.3.t and greater than 0.7.t have tangents less than about -0.1 MPa / μm or greater than about 0.1 MPa / μm.

[0007] In some embodiments, the glass-based article contains a non-zero concentration of metal oxides that varies along most or all of its thickness. This variation in metal oxide concentration may be referred to herein as a gradient. In some embodiments, the metal oxide concentration is not zero and varies along a thickness range of about 0.t to about 0.3.t. In some embodiments, the metal oxide concentration is not zero and varies along thickness ranges 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 oxides can be described as generating stress in the glass-based article. The variation in metal oxide concentration may include a change of about 0.2 mol% along a thickness segment of about 100 micrometers. The concentration variation may occur continuously along the aforementioned thickness range. In some embodiments, the concentration variation may occur continuously along a thickness segment ranging from about 10 micrometers to about 30 micrometers.

[0008] In some embodiments, the concentration of the metal oxide decreases from the first surface to a position between the first and second surfaces, and increases from said position to the second surface.

[0009] As used herein, the metal oxide contains reinforcing ions or ions that generate CS in the glass substrate. In some embodiments, the metal oxide has the largest ion diameter among all the total metal oxides in the glass substrate. In one or more embodiments, the metal oxide may contain alkali metal oxides, or different metal oxides or combinations of alkali metal oxides. Exemplary metal oxides include Ag₂O. Exemplary alkali metal oxides include any one or more of Li₂O, Na₂O, K₂O, Rb₂O, and Cs₂O. The metal oxide may be present at a non-zero concentration, wherein the concentration of a particular metal oxide varies along most or all of the thickness of the glass substrate. In some embodiments, the metal oxide concentration decreases from a first surface to a location between the first and second surfaces, and increases from said location to the second surface. The concentration of the metal oxide at this location may not be zero.

[0010] The concentration of metal oxides throughout the entire thickness can be about 0.05 mol% or greater, or about 1 mol% or greater. For example, the Na₂O concentration throughout the entire thickness of the glass substrate can be about 0.05 mol% or greater, but the Na₂O concentration decreases from the first surface to a location between the first and second surfaces, and increases from that location to the second surface. In some ions, the total concentration of metal oxides along the entire thickness of the glass substrate is in the range of about 1 mol% to about 20 mol%. In some embodiments, the concentration of metal oxides near the surface can be 1 to 1.5 times (e.g., 5, 10, 15, or even 20 times) greater than the concentration of the same metal oxides at a depth in the range of about 0.4 to about 0.6 t. The concentration of metal oxides can be determined by the baseline amount of that metal oxide concentration in the glass substrate before it is modified to exhibit a concentration profile (i.e., the gradient or change described herein).

[0011] In one or more embodiments, the glass-based article comprises a first metal oxide concentration and a second metal oxide concentration, such that the first metal oxide concentration is in the range of 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 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 comprise an optional third metal oxide concentration. The first metal oxide may be Na₂O, and the second metal oxide may be K₂O.

[0012] In one or more embodiments, the glass-based article has a surface pressure (CS) of about 150 MPa or greater, or about 200 MPa or greater. In one or more embodiments, the glass-based article may have a surface pressure (CS) greater than about 300 MPa, greater than about 600 MPa, or greater than about 700 MPa. The glass-based article may have a chemical depth of about 0.4 t or greater.

[0013] In some embodiments, the glass-based article may comprise a CS layer extending from a first surface to about 0.1•t or greater of DOC. In some examples, the glass-based article comprises a CT layer containing a non-zero metal oxide concentration varying along most of the thickness t. The CT layer may have a maximum CT such that the ratio of the maximum CT to the surface CS is in the range of about 0.01 to about 0.5. The maximum CT may be about 25 MPa or greater.

[0014] In one or more embodiments, the glass-based article may exhibit fracture resistance such that when the glass-based article breaks, it breaks into at least 2 fragments per inch. 2 In some ions, glass-based articles can break into 3 fragments per inch. 2 More or 5 pieces / inch2 More or 10 pieces / inch 2 Or more.

[0015] In some cases, glass-based articles can have a strength greater than about 0 J / m 2 And less than 20 J / m 2 Stretching energy storage.

[0016] The CT region of one or more embodiments of a glass-based article can exhibit a stress curve defined by the following formula: Stress(x) = MaxCT - (MaxCT•(n+1)) / 0.5 n •|(x / t)-0.5| n ), where MaxCT is the maximum CT value, which is a positive value in MPa, x is the position along the thickness (t) in micrometers, and n is between 1.5 and 5 (or between 1.8 and about 2).

[0017] Glass-based articles may contain amorphous structures, crystalline structures, or combinations thereof. Glass-based articles may be transparent or opaque. In some embodiments, the glass-based article is substantially white or substantially black. Additionally or alternatively, the glass-based article may contain a colorant that provides a specific color.

[0018] A second aspect of this disclosure relates to an amorphous glass substrate comprising, in mole percent: SiO2, in an amount ranging from about 68 to about 75; Al2O3, in an amount ranging from about 12 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 8; 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. In some embodiments, the glass substrate exhibits any one or more of the following: a Li2O to R2O ratio ranging from about 0.5 to about 1; a difference between the total amount of R2O and the amount of Al2O3 ranging from about -5 to about 0; R x The difference between the total amount of O (in mole%) and the amount of Al2O3 is in the range of about 0 to about 3; and the ratio of the amount of MgO (in mole%) to the total amount of RO (in mole%) is in the range of about 0 to about 2.

[0019] In one or more embodiments, the glass substrate is capable of ion exchange. In other embodiments, the glass substrate is strengthened using an ion exchange process.

[0020] A third aspect of this disclosure relates to a method for forming a fracture-resistant glass-based article as described herein. Embodiments of this method include providing a glass-based substrate having a first surface and a second surface defined as having a thickness of about 3 mm or less; generating a stress profile in the glass-based substrate comprising a CT layer and a CS layer, wherein the CS layer has a surface CS, a chemical depth of about 0.4 t or more, and a DOC of about 0.1 t or more; and the CT layer has a maximum CT, and the ratio of the maximum CT to the surface CS is about 0.01 to about 0.5.

[0021] Other features and advantages of the invention are set forth in the following detailed description, some of which will be readily apparent to those skilled in the art from the description, or will be recognized by practicing the various embodiments described herein, including the following detailed description, the claims, and the drawings.

[0022] It should be understood that the foregoing general description and the following detailed description are merely exemplary, intended to provide a general overview or framework for understanding the nature and characteristics of the claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, provide a further understanding of the invention. The drawings illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles and operation of various embodiments.

[0023] Brief description of the attached figures Figure 1 It is a cross-sectional view through the known thickness of a heat-tempered glass-based product; Figure 2 It is a cross-sectional view through the known thickness of a chemically strengthened glass-based article; Figure 3 It is a cross-sectional view through the thickness of a chemically strengthened glass-based article according to one or more embodiments of the present disclosure; Figure 4 This is a schematic cross-sectional view of the ring-to-ring device; Figure 5 It is a graph showing the Na2O concentration in known chemically strengthened glass articles and glass articles according to one or more embodiments of the present disclosure. Figure 6 It is a graph showing the relationship between CT values ​​and DOC values ​​and ion exchange time according to one or more embodiments of the present disclosure; Figure 7 It is a graph comparing stress curves that vary with depth of known chemically strengthened glass-based articles and glass-based articles according to one or more embodiments of the present disclosure. Figure 8The stress curves of known chemically strengthened glass and glass-ceramics are shown. Figure 9 Stress curves of glass and glass-ceramics according to one or more embodiments of the present disclosure are shown. Figure 9A The failure height diagram in the drop test of Example 3D is shown; Figure 10 It is a comparison graph showing stress curves of known chemically strengthened glass-based articles and glass-based articles according to one or more embodiments of the present disclosure. Figure 11 It is a graph showing the relationship between stress curves and thickness for Examples 4A to 4D; Figure 12 It is a graph showing discrete tensile energy storage data points of Examples 4B to 4D; Figure 13 It is a graph showing the relationship between the concentrations of K2O and Na2O and the depth in Examples 4A to 4D; Figure 14 It is a display Figure 12 The same data is presented in a chart, but at a different scale to more clearly illustrate the change in Na2O concentration with depth.

[0024] Figure 15 It is a graph showing the relationship between stress curves and depth for Examples 4A and 4C to 4F; Figure 16 It displays different proportions. Figure 14 The chart; Figure 17 It is a graph showing the relationship between stress curves and depth for Examples 5A to 5G; Figure 18 It is a graph showing the relationship between the DOC values ​​of Examples 5A-5G and the duration of the second and / or third ion exchange steps; Figure 19 It is a graph showing the relationship between the CT values ​​of Examples 5A to 5G and the duration of the second and / or third ion exchange steps; Figure 20 It is a graph showing the relationship between stress curves and depth for Examples 6A-1 to 6A-6; Figure 21 It is a graph showing the relationship between CT and DOC values ​​and ion exchange time for Examples 6A-1 to 6A-6; Figure 22 It is a graph showing the relationship between stress curves and depth for Examples 6B-1 to 6B-6; Figure 23 It is a graph showing the relationship between CT and DOC values ​​and ion exchange time for Examples 6B-1 to 6B-6; Figure 24 It is a graph showing the relationship between stress curves and depth for Examples 6C-1 to 6C-6; Figure 25 It is a graph showing the relationship between CT and DOC values ​​and ion exchange time for Examples 6C-1 to 6C-6; Figure 26 It is a graph showing the relationship between stress curves and depth for Examples 6D-1 to 6D-6; Figure 27 It is a graph showing the relationship between CT and DOC values ​​and ion exchange time for Examples 6D-1 to 6D-6; Figure 28 It is a graph showing the relationship between CT and ion exchange time in Examples 7A to 7G; Figure 29 It is a graph showing the changes in center tension values ​​and tensile energy storage of Examples 7A to 7G with ion exchange time; Figure 30 It is a graph showing the relationship between stress curves and depth for Comparative Example 8A and Example 8B; Figure 31 It is a graph showing the relationship between tensile energy storage and CT in Comparative Example 8A and Example 8B; and Figure 32 This is a graph showing the relationship between tensile energy storage and CT for Comparative Example 8C and Example 8D.

[0025] Figure 33 It is a graph showing the fall failure height of Examples 2, 6 and 9B and Comparative Example 9I; Figure 34 These are graphs showing the wear ring stacking results of Examples 2, 6, 9B and Comparative Example 9J; Figure 35 This is a Weibull distribution plot showing the four-point bending results of Examples 2 and 9B; Figure 36 This is a schematic cross-sectional view of one embodiment of the apparatus used for performing the Inverted Ball on Sandpaper (IBoS) test described in this disclosure; Figure 37 It is a schematic cross-sectional illustration of the main mechanisms of failure caused by damage introduction and bending, which commonly occur in glass-based products used in mobile or handheld electronic devices. Figure 38 A flowchart illustrating a method for performing IBoS testing in the device described herein; and Figure 39 It is a graph illustrating various stress curves according to one or more embodiments of the present disclosure. Invention Details Various implementation methods will now be described in detail, examples of which are shown in the accompanying embodiments and drawings.

[0026] In the following description, in several views shown in all the accompanying drawings, the same reference numerals denote similar or corresponding parts. It should also be understood that, unless otherwise stated, terms such as “top,” “bottom,” “outward,” “inward,” etc., are used for convenience and should not be considered restrictive. Furthermore, whenever a group is described as comprising at least one of a set of elements and combinations thereof, it should be understood that the group may contain any number of these listed elements in the form of individual elements or combinations thereof, or consist primarily of any number of these listed elements, or consist of any number of these listed elements. Similarly, whenever a group is described as consisting of at least one of a set of elements or combinations thereof, it should be understood that the group may consist of any number of these listed elements in the form of individual elements or combinations thereof. Unless otherwise stated, the enumerated numerical ranges include both the upper and lower limits of the range, as well as any range between the upper and lower limits. Unless otherwise stated, the modifiers “a” or “an” and their corresponding modifiers “the” used herein mean “at least one” or “one or more”. It should also be understood that the various features disclosed in the specification and drawings can be used in any and all combinations.

[0027] As used herein, the terms “glass-based article” and “glass-based substrate” are used in their broadest sense to include any object made wholly 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 stated, all compositions are expressed as mole percentages (mol%).

[0028] It should be noted that the terms "substantially" and "about" are used herein to indicate the inherent degree of uncertainty that may arise from any quantitative comparison, numerical value, measurement, or other method of representation. These terms are also used herein to indicate that the representation of quantities may deviate to a certain extent from the stated reference value, but without causing a change in the fundamental function of the object being addressed. Thus, for example, a glass-based article that is "substantially free of MgO" means that MgO is not actively added to or incorporated into the glass-based article, but may be present as a contaminant in very small amounts.

[0029] See the attached diagram for an overall view, and refer to the diagram for details. Figures 1-3It should be understood that the illustrations are for illustrating specific embodiments of the invention and do not constitute a limitation on the content of the invention or the appended claims. For clarity and simplicity, the drawings are not necessarily drawn to scale, and some features and views may be shown enlarged to scale or schematically.

[0030] As used herein, DOC refers to the depth at which stress within a glass-based material transitions from compressive stress to tensile stress. At the DOC, stress changes from positive (compressive) stress to negative (tensile) stress (e.g., ...). Figure 1 (130 in the middle), therefore the stress value at that point is zero.

[0031] As used herein, the terms "chemical depth," "chemical layer depth," and "depth of chemical layer" are used interchangeably and refer to the depth to which ions of metal oxides or alkali metal oxides (e.g., metal ions and alkali metal ions) diffuse into a glass substrate, and the depth to which the ion concentration reaches a minimum, as determined by electron probe microanalysis (EPMA) or glow discharge-emission spectroscopy (GD-OES). Specifically, to assess the depth of Na₂O diffusion or Na… + Ion concentrations can be determined using EPMA and FSM (described in detail below).

[0032] According to convention in the art, compression is expressed as negative (<0) stress, while tension is expressed as positive (>0) stress. However, in this specification, CS is expressed as a positive or absolute value, that is, as stated herein, CS = |CS|.

[0033] This article describes thin, chemically strengthened glass-based products, including: glass, such as silicate glass including alkali metal glass; and glass ceramics that can be used as cover glass for mobile electronic devices and touchscreen displays. Glass-based products can also be used in displays (or display products) (e.g., billboards, point-of-sale terminals, computers, navigation systems, etc.), building products (walls, fixtures, panels, windows, etc.), transportation products (e.g., for automotive applications, trains, airplanes, ships, etc.), household appliances (e.g., washers, desiccants, dishwashers, refrigerators, etc.), or any product requiring a certain degree of fracture resistance.

[0034] Specifically, the glass-based articles described herein are thin and exhibit stress profiles typically achievable only with tempering thicker glass articles (e.g., approximately 2 mm or 3 mm thick or more). The glass-based articles exhibit unique stress profiles along their thickness. In some cases, the glass-based articles exhibit a larger surface area coefficient (CS) than tempered glass articles. In one or more embodiments, the glass-based articles exhibit a deeper compressive stress layer depth (in which the CS decreases or increases more gradually compared to known chemically strengthened glass-based articles), resulting in significantly improved fracture resistance, even when the glass-based article or the device containing it is dropped onto a hard, rough surface. One or more embodiments of the glass-based articles exhibit a larger maximum CT value than some known chemically strengthened glass substrates.

[0035] The CS and the depth of the compressive stress layer (“DOL”) are measured using methods known in the art. DOL is distinguished from DOC by measurement techniques, wherein DOL is determined by a surface stress meter (FSM) using a commercially available instrument such as the FSM-6000 manufactured by Luceo Ltd. (Tokyo, Japan) or a similar instrument. Methods for measuring CS and layer depth are described in ASTM 1422C-99, entitled “Standard Specification for Chemically Strengthened Flat Glass,” and ASTM 1279.19779, “Standard Test Method for Non-Destructive Photoelastic Measurement of Edge and Surface Stresses in Annealed, Heat-Strengthened, and Fully-Tempered Flat Glass,” both of which are incorporated herein by reference in their entirety. Surface stress testing relies on the accurate determination of the stress optical coefficient (SOC), which is related to the birefringence of the glass. SOC is measured using methods known in the art, such as the fiber and four-point bending method and the large cylinder method. The fiber and four-point bending method is described in ASTM standard C770-98 (2008) entitled "Standard Test Method for Measurement of Glass Stress-Optical Coefficient," the full text of which is incorporated herein by reference.

[0036] For strengthened glass substrates where the compressive stress layer extends to a considerable depth within the substrate, FSM technology encounters contrast issues, affecting the observed DOL values. At deeper DOL values, the contrast between TE and TM spectra may be insufficient, making it more difficult to calculate the differences between TE and TM spectra (and to determine the DOL). Furthermore, FSM technology cannot determine the stress profile (i.e., the change in CS with depth within the glass substrate). Additionally, FSM technology cannot measure DOL resulting from ion exchange of certain elements (e.g., sodium replacing lithium).

[0037] The techniques described below were developed to enable more accurate determination of the DOC and stress profiles of reinforced glass-based articles.

[0038] U.S. Application Serial No. 13 / 463322 (hereinafter referred to as "Rostislav I"), entitled "Systems and Methods for Measuring the Stress Profile of Ion-Exchanged Glass," filed May 3, 2012, by Rostislav V. Roussev et al., discloses two methods for extracting detailed and accurate stress profiles (stress versus depth relationships) of tempered or chemically strengthened glass. This document claims priority to U.S. Provisional Patent Application No. 61 / 489800, filed May 25, 2011, with the same title. The spectra of TM and TE polarized band optical modes are collected using prism coupling techniques, and these spectra are used holistically to obtain detailed and accurate TM and TE refractive index profiles nTM(z) and nTE(z). The contents of the aforementioned application are incorporated herein by reference in their entirety.

[0039] In one implementation, the inverse Wenzel-Kremer-Brillouin (IWKB) method is used to obtain detailed refractive index profiles through modal spectra.

[0040] In another implementation, a detailed refractive index profile is obtained by fitting the measured modulus to a mathematically calculated spectrum in a predefined functional form describing the shape of the refractive index profile, and by extracting the parameters of the functional form from the best fit. The detailed stress profile S(z) is calculated from the difference between the recovered TM and TE exponents using known stress-optical coefficient (SOC) values. S(z)=[n TM (z)-n TE (z)] / SOC (2).

[0041] Due to the small SOC value, birefringence n at any depth z TM (z)-n TE (z) only accounts for the exponent n TM (z) and n TE(z) is a small fraction (typically around 1%). Obtaining a stress curve that is not significantly distorted by noise in the measured modulus spectrum requires determining the mode effective index with an accuracy of around 0.00001 RIU. The method disclosed in Roussev I also includes techniques applied to the raw data to ensure this high accuracy for the measured modulus index despite noise and / or poor contrast in the collected TE and TM modulus spectra or modulus images. These techniques include noise averaging, filtering, and curve fitting to find locations where the mode closely matches the subpixel resolution.

[0042] Similarly, U.S. Patent Application No. 14 / 033954 (hereinafter referred to as "Roussev II"), filed September 23, 2013, entitled "Systems and Methods for Measuring Birefringence in Glass and Glass-Ceramics," discloses an apparatus and method for optically measuring the birefringence of glass and glass-ceramic surfaces, including opaque glass and glass-ceramic surfaces. This document claims priority to U.S. Provisional Application Serial No. 61 / 706891, filed September 28, 2012, with the same title. Unlike Roussev I, which identifies discrete mode spectra, the method disclosed in Roussev II relies on careful analysis of the angular intensity distribution of TM and TE rays reflected from the prism-sample interface in a prism-coupled configuration being measured. The contents of the aforementioned applications are incorporated herein by reference in their entirety.

[0043] Therefore, the correct distribution of reflected light intensity vs. angle is far more important than in conventional prism-coupled stress testing, where only the location of discrete modes is sought. To this end, the methods disclosed in Roussev I and Roussev II include techniques for normalizing the intensity spectrum, including normalization to a reference image or signal, correction for detector nonlinearity, averaging multiple images to reduce image noise and speckle, and applying digital filtering to further smooth the angular intensity spectrum. Another method involves shaping the contrast signal, which is further normalized to correct for fundamental differences in the shapes of the TM and TE signals. These methods rely on obtaining two nearly identical signals and determining their mutual displacement at sub-pixel resolution by comparing the signal portions containing the most drastically changing regions. Birefringence is proportional to this mutual displacement and has a coefficient determined by the device design, which includes the prism geometry and refractive index, the focal length of the lens, and the pixel pitch on the display. The measured birefringence is multiplied using known stress-optical coefficients to determine the stress.

[0044] In another disclosed method, the derivatives of the TM and TE signals are determined after applying some combinations of the aforementioned signal conditioning techniques. The positions of the maximum derivatives of the TM and TE signals are obtained through sub-pixel resolution, and the birefringence is proportional to the distance between the two maximum values, having a coefficient previously determined by device parameters.

[0045] To address the need for modified intensity extraction, the apparatus includes several optimizations, such as using a light-scattering surface (electrostatic diffuser) adjacent to or located on the prism entrance surface to improve the angular uniformity of illumination; using a moving diffuser to reduce speckling when the light source is coherent or partially coherent; and applying light-absorbing coatings to the prism's input and output surfaces, as well as some portions of its sides, to mitigate parasitic background that tends to distort the intensity signal. Furthermore, these devices may include an infrared light source to enable measurements on opaque materials.

[0046] Furthermore, Roussev II disclosed a range of wavelengths and attenuation coefficients for the studied samples, within which measurements could be performed using the methods and equipment described above. This range is defined as α. s λ≤250πσ s , where α s It measures the optical attenuation coefficient at wavelength λ, σ sThis is the predicted value of the stress to be measured at the accuracy typically required in practical applications. This broad range allows for practically valuable measurements at wavelengths with high light attenuation, where previous measurement methods were inapplicable. For example, Roussev II disclosed the successful measurement of stress-induced birefringence in opaque white glass-ceramics at a wavelength of 1550 nm, where attenuation is greater than approximately 30 dB / mm.

[0047] Although the FSM technique has some limitations known above for deeper DOLs, it remains a useful and routine technique, with an error range that can be as high as + / - 20% when used at deeper DOLs. In this paper, DOL refers to the compressive stress layer depth calculated using the FSM technique, while DOC refers to the compressive stress layer depth determined using the methods described in Roussev I and II.

[0048] As described above, the glass-based articles described herein can be chemically strengthened through ion exchange and exhibit stress curves different from those of known strengthened glasses. In this process, ions at or near the surface of the glass-based article are replaced (or exchanged) by larger ions with the same valence or oxidation state. In embodiments where the glass-based article comprises alkaline aluminosilicate glass, the ions in the glass surface layer, as well as the larger ions, are monovalent alkali metal cations, such as Li. + (When present in glass-based products), Na + K + 、Rb + and Cs + Alternatively, monovalent cations in the surface layer can be replaced by substances such as Ag. + Substitution with monovalent cations other than alkali metal cations.

[0049] Ion exchange processes are typically performed by immersing a glass substrate in one (or two or more) molten salt baths containing larger ions to be exchanged with smaller ions in the glass substrate. It should be noted that aqueous solutions of the salt baths can also be used. Furthermore, the bath composition may contain more than one type of larger ion (e.g., Na+). + and K +(or a single, larger ion.) Those skilled in the art will understand that the parameters of the ion exchange process include, but are not limited to, the composition and temperature of the bath, the immersion time, the number of times the glass substrate is immersed in one (or more) salt baths, the use of multiple salt baths, and additional steps such as annealing and washing. These parameters are typically determined based on the composition of the glass substrate (including the structure of the substrate and any crystalline phases present) and the desired DOL or DOC and CS of the glass substrate obtained through strengthening operations. For example, ion exchange of glass substrates can be achieved by immersing the glass substrate in at least one molten bath containing salts, such as, but not limited to, nitrates, sulfates, and hydrochlorides of larger alkali metal ions. Typical nitrates include KNO3, NaNO3, LiNO3, NaSO4, and combinations thereof. The temperature of the molten salt bath is typically in the range of about 380°C to a maximum of about 450°C, while the immersion time ranges from about 15 minutes to a maximum of about 100 hours, depending on the glass thickness, bath temperature, and glass diffusivity. However, different temperatures and soaking times than those described above can also be used.

[0050] In one or more embodiments, the glass substrate can be immersed in a molten salt bath of 100% NaNO3 at a temperature of about 370°C to about 480°C. In some embodiments, the glass substrate can be immersed in a molten mixed salt bath containing about 5% to about 90% KNO3 and about 10% to about 95% NaNO3. In some embodiments, the glass substrate can be immersed in a molten mixed salt bath containing Na2SO4 and NaNO3 and having a wider temperature range (e.g., not exceeding about 500°C). In one or more embodiments, the glass substrate can 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% KNO3 for 15 minutes to 8 hours.

[0051] The conditions of ion exchange can be adjusted to provide a "spiking" or increase the slope of the stress curve at or near the surface. This spike can be achieved by a single bath or multiple baths having a single composition or a mixture of compositions, due to the unique properties of the glass compositions used in the glass-based articles described herein.

[0052] like Figure 3As shown, a glass-based article 300 according to one or more embodiments includes a first surface 302 defining a thickness t and a second surface 304 opposite to the first surface. In one or more embodiments, the thickness t may be about 3 mm or thinner (e.g., in the range of about 0.01 mm to about 3 mm, about 0.1 mm to about 3 mm, about 0.2 mm to about 3 mm, about 0.3 mm to about 3 mm, about 0.4 mm to about 3 mm, about 0.01 mm to about 2.5 mm, about 0.01 mm to about 2 mm, about 0.01 mm to about 1.5 mm, about 0.01 mm to about 1 mm, about 0.01 mm to about 0.9 mm, about 0.01 mm to about 0.8 mm, about 0.01 mm to about 0.7 mm, about 0.01 mm to about 0.6 mm, about 0.01 mm to about 0.5 mm, about 0.1 mm to about 0.5 mm, or about 0.3 mm to about 0.5 mm).

[0053] The glass-based article has a stress profile extending from the first surface 302 to the second surface 304 (or along the entire length of thickness t). Figure 3 The illustrated embodiment shows stress curve 312 measured using Roussev I and II as described herein and stress curve 340 estimated using FSM as described herein. The x-axis represents the stress value, and the y-axis represents the thickness or depth within the glass substrate.

[0054] like Figure 3 As shown, stress curve 312 reveals CS layer 315 (with surface CS 310), CT layer 325 (with maximum CT 320), and DOC 317, where stress curve 312 transitions from compression to tension at 330. CT layer 325 also has an associated depth or length 327 (CT region or layer). The estimated stress curve 340 exhibits a DOL greater than DOC. As used herein, DOC and DOL are relative to depths measured from one surface (first surface 302 or second surface 304), and it should be understood that DOC or DOL may also be measured from another surface.

[0055] Surface CS 310 may be approximately 150 MPa or greater, or approximately 200 MPa or greater (e.g., approximately 250 MPa or greater, approximately 300 MPa or greater, approximately 400 MPa or greater, approximately 450 MPa or greater, approximately 500 MPa or greater, or approximately 550 MPa or greater). Surface CS 310 may not exceed approximately 900 MPa, not exceed approximately 1000 MPa, not exceed approximately 1100 MPa, or not exceed approximately 1200 MPa. Maximum CT 320 may be approximately 25 MPa or greater, approximately 50 MPa or greater, or approximately 100 MPa or greater (e.g., approximately 150 MPa or greater, approximately 200 MPa or greater, approximately 250 MPa or greater, or approximately 300 MPa or greater). In some embodiments, the maximum CT 320 can be in the range of about 50 MPa to about 250 MPa (e.g., about 75 MPa to about 250 MPa, about 100 MPa to about 250 MPa, about 150 MPa to about 250 MPa, about 50 MPa to about 175 MPa, about 50 MPa to about 150 MPa, or about 50 MPa to about 100 MPa). The maximum CT 320 can be located in the 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 either or more of the surface CS 310 and the maximum CT 320 can depend on the thickness of the glass substrate article. For example, a glass substrate article with a thickness of about 0.8 mm can have a maximum CT of about 100 MPa or greater. When the thickness of the glass substrate article decreases, the maximum CT can increase. In other words, the maximum CT increases as the thickness decreases (or as the glass substrate becomes thinner).

[0056] In some embodiments, the ratio of the maximum CT 320 to the surface CS 310 can be in the range of about 0.05 to about 1 (e.g., in the ranges of about 0.05 to about 0.5, about 0.05 to about 0.3, about 0.05 to about 0.2, about 0.05 to about 0.1, about 0.5 to about 0.8, about 0.05 to about 1, about 0.2 to about 0.5, and about 0.3 to about 0.5). In known chemically strengthened glass-based articles, the ratio of the maximum CT 320 to the surface CS 310 is 0.1 or less. In some embodiments, the surface CS can be 1.5 times (or 2 times or 2.5 times) or greater than the maximum CT. In some embodiments, the surface CS can be up to about 20 times the maximum CT.

[0057] In one or more embodiments, stress profile 312 includes a maximum CS, which is typically surface CS 310, and may appear on either or both of the first surface 302 and the second surface 304. In one or more embodiments, the CS layer or region 315 extends along a portion of the thickness to DOC 317 and maximum CT 320. In one or more embodiments, DOC 317 may be about 0.1•t or greater. For example, DOC 317 may 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 not exceeding about 0.25•t. In some embodiments, DOC 317 is less than chemical depth 342. The chemical depth can be about 0.4 t or deeper, 0.5 t or deeper, about 55 t or deeper, or about 0.6 t or deeper. In one or more embodiments, the stress curve 312 can be described as having a parabolic shape. In some embodiments, the stress curve along the region or depth of the glass substrate exhibiting tensile stress exhibits a parabolic shape. In one or more embodiments, the stress curve 312 does not include a flat stress (i.e., compressive or tensile) portion or exhibits a substantially constant stress (i.e., compressive or tensile) portion. In some embodiments, the CT region exhibits a stress curve that substantially does not include flat stress or substantially constant stress. In one or more embodiments, all points on the stress curve 312 with a thickness ranging from about 0 t to about 0.2 t and greater than 0.8 t (or about 0 t to about 0.3 t and greater than 0.7 t) have a tangent less than about -0.1 MPa / μm or greater than about 0.1 MPa / μm. In some embodiments, the tangent may be less than about -0.2 MPa / µm or greater than about 0.2 MPa / µm. In some more specific embodiments, the tangent may be less than about -0.3 MPa / µm or greater than about 0.3 MPa / µm. In a more specific embodiment, the tangent may be less than about -0.5 MPa / µm or greater than about 0.5 MPa / µm. In other words, the stress curves of one or more embodiments along these thickness ranges (i.e., 0•t to about 2•t and greater than 0.8•t, or about 0t to about 0.3•t and 0.7•t or greater) do not contain points with tangents as described above.Unintentionally limited by theory, the known error function or quasi-linear stress curves along these thickness ranges (i.e., 0•t to about 2•t and greater than 0.8•t, or about 0•t to about 0.3•t and 0.7•t or greater) contain points with tangents in the following ranges: about -0.1 MPa / μm to about 0.1 MPa / μm, about -0.2 MPa / μm to about 0.2 MPa / μm, about -0.3 MPa / μm to about 0.3 MPa / μm, or about -0.5 MPa / μm to about 0.5 MPa / μm (including flatness or zero slope of the stress curves along these thickness ranges, e.g.) Figure 2 (As shown in 220). The stress curves of one or more embodiments of this disclosure do not exhibit stress curves with a flat or zero slope along these thickness ranges, such as... Figure 3 As shown.

[0058] In one or more embodiments, the glass-based article exhibits stress profiles with maximum and minimum tangents in thickness ranges of about 0.1•t to 0.3•t and about 0.7•t to 0.9•t. In some examples, the difference between the maximum and minimum tangents is about 3.5 MPa / μm or less, about 3 MPa / μm or less, about 2.5 MPa / μm or less, or about 2 MPa / μm or less.

[0059] In one or more embodiments, the stress curve 312 substantially does not contain any linear segments extending along the depth direction or along at least a portion of the thickness t of the glass substrate. In other words, the stress curve 312 substantially rises or falls continuously along the thickness t. In some embodiments, the stress curve substantially does not contain any linear segments along the depth direction that are approximately 10 micrometers or longer, approximately 50 micrometers or longer, approximately 100 micrometers or longer, or approximately 200 micrometers or longer. As used herein, the term "linear" means a slope along a linear segment that is less than approximately 5 MPa / micrometer or less than approximately 2 MPa / micrometer. In some embodiments, one or more portions of the stress curve that substantially contain no linear segments in the depth direction exist within the glass substrate at a depth of approximately 5 micrometers or deeper (e.g., 10 micrometers or deeper, or 15 micrometers or deeper), measured from one or both of the first or second surfaces. For example, along a depth from about 0 micrometers to less than about 5 micrometers from the first surface, the stress curve may contain a linear segment, but from a depth of about 5 micrometers or more from the first surface, the stress curve may substantially not contain a linear segment.

[0060] In some embodiments, the stress profile may include a linear segment at a depth of about 0 t to about 0.1 t, and substantially no linear segment at a depth of about 0.1 t to about 0.4 t. In some embodiments, the stress profile may have a slope ranging from about 20 MPa / µm to about 200 MPa / µm from a thickness in the range of about 0 t to about 0.1 t. As will be described herein, these embodiments may be formed using a single ion exchange process, in which the bath may contain two or more basic salts, or a mixed basic salt bath, or multiple (e.g., two or more) ion exchange processes.

[0061] In one or more embodiments, the glass-based article can be visualized by stress curves along the CT region ( Figure 3 The shape of 327 in the figure is used to describe this. For example, in some embodiments, the stress curve along the CT region (where the stress is tensile stress) can be estimated using a formula. In some embodiments, the stress curve along the CT region can be estimated using the following formula (1): Stress(x) = MaxCT - (MaxCT•(n+1)) / 0.5 n •|(x / t)-0.5| n (1) In equation (1), stress (x) is the stress value at position x. The stress here is a positive value (tension). MaxCT is the maximum center tension, a positive value in MPa. The value x is along the thickness (t), in micrometers, and falls within the range of 0 to t; x=0 is a surface ( Figure 3 In point 302), x=0.5t is the center of the glass-based product, stress (x)=MaxCT, and x=t is the opposite surface ( Figure 3 304 in Equation (1). The MaxCT used in Equation (1) can be in the range of about 50 MPa to about 350 MPa (e.g., 60 MPa to about 300 MPa, or about 70 MPa to about 270 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). n=2 can provide a parabolic stress curve, and the exponent derived from n=2 can provide a stress curve that approximates a parabolic stress curve. Figure 39 Exemplary stress curves for different combinations of MaxCT and n (as shown in the examples 1.5 to 5) of a glass substrate with a thickness of 0.8 mm are displayed.

[0062] In some embodiments, heat treatment can be used to modify the stress profile. In these embodiments, heat treatment can be performed before, between, or after any ion exchange treatment. In some embodiments, heat treatment can result in a decrease in the slope of the stress profile at or near the surface. In some embodiments, where a steeper or greater slope at the surface is desired, ion exchange treatment can be performed after heat treatment to give the stress profile a "peak" or a greater slope at or near the surface.

[0063] In one or more embodiments, stress curve 312 (and / or estimated stress curve 340) is generated by a non-zero metal oxide concentration varying along a portion of the thickness. This variation in concentration may be referred to herein as a gradient. In some embodiments, the metal oxide concentration is non-zero and varies along a thickness range of about 0.t to about 0.3.t. In some embodiments, the metal oxide concentration is non-zero and varies along thickness ranges 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 can be described as generating stress in the glass-based article. The concentration variation can occur continuously along the aforementioned thickness range. The concentration variation may include a metal oxide concentration varying by about 0.2 mol% along a thickness segment of about 100 micrometers. This variation can be measured by methods known in the art, including microprobes, as shown in Example 1. Metal oxides with a non-zero concentration and a concentration varying along a portion of the thickness can be described as generating stress in the glass-based article.

[0064] The concentration variation can occur continuously along the aforementioned thickness range. In some embodiments, the concentration variation can occur continuously along a thickness range of about 10 micrometers to about 30 micrometers. In some embodiments, the metal oxide concentration decreases from the first surface to a location between the first and second surfaces, and increases from said location to the second surface.

[0065] The concentration of metal oxides may include more than one metal oxide (e.g., a combination of Na₂O and K₂O). In some embodiments, when using two metal oxides with different ionic radii, at shallower depths, the concentration of ions with larger radii is greater than the concentration of ions with smaller radii, while at deeper depths, the concentration of ions with smaller radii is greater than the concentration of ions with larger radii. For example, in the case of using a single bath containing Na and K in ion exchange treatment, at shallower depths, the concentration of K in the glass substrate is higher than that of ions with larger radii. + Ion concentration greater than Na + Ion concentration, and at deeper depths, Na + Concentration greater than K +The concentration of ions. This is partly due to ion size. In these glass-based articles, the region at or near the surface has a larger CS (concentration stress), because there are more larger ions at or near the surface. This larger CS can be manifested as a steeper slope in the stress curve at or near the surface (i.e., another curve with a sharp peak at the surface).

[0066] The concentration gradient or variation of one or more metal oxides is generated by chemically strengthening the glass substrate, for example, through the ion exchange process described above, wherein a plurality of first metal ions in the glass substrate are exchanged by a plurality of second metal ions. The first ions may be lithium, sodium, potassium, and rubidium ions. The second metal ions may be ions of sodium, potassium, rubidium, and cesium, provided that the ionic radius of the second alkali metal ion is greater than the ionic radius of the first alkali metal ion. The second metal ions are present in the glass substrate as oxides (e.g., Na₂O, K₂O, Rb₂O, Cs₂O, or combinations thereof).

[0067] In one or more embodiments, a metal oxide gradient extends through most or all of the thickness t of the glass substrate, including the CT layer 325. In one or more embodiments, the metal oxide concentration in the CT layer 325 is about 0.5 mol% or greater. In some embodiments, the metal oxide concentration along the entire thickness of the glass substrate may be about 0.5 mol% or greater (e.g., about 1 mol% or greater), and is maximum at the first surface 302 and / or the second surface 304, decreasing at a substantially constant rate to a location between the first surface 302 and the second surface 304. At this location, the metal oxide concentration along the entire thickness t is minimum; however, the concentration is not zero at this location. In other words, a non-zero concentration of a specific metal oxide extends along most of the thickness t (as described herein) or the entire thickness t. In some embodiments, the minimum concentration of a specific metal oxide occurs in the CT layer 327. The total concentration of a particular metal oxide in the glass substrate may range from about 1 mol% to about 20 mol%.

[0068] In one or more embodiments, the glass-based article comprises a first metal oxide concentration and a second metal oxide concentration, such that the first metal oxide concentration is in the range of 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 is in the range of about 0 mol% to about 10 mol% (or about 0 micrometers to about 12 micrometers) from a second thickness range of about 0 micrometers to about 25 micrometers. The glass-based article may comprise an optional third metal oxide concentration. The first metal oxide may comprise Na₂O, and the second metal oxide may comprise K₂O.

[0069] The concentration of metal oxides can be determined by the baseline amount of those metal oxides in the glass matrix before it is modified to include a concentration gradient of those metal oxides.

[0070] In one or more embodiments, glass-based articles can be described by how they fracture and the fragments produced by said fracture. In one or more embodiments, upon fracture, the glass-based article breaks into two or more fragments per square inch (or 6.4516 square centimeters) of the original glass-based article (before fracture). 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 6.4516 square centimeters) of the original glass-based article (before fracture). In some examples, upon fracture, the glass-based article breaks into multiple fragments, of which 50% or more have a surface area less than 5%, 2%, or 1% of the surface area of ​​the original glass-based article fragments. In some embodiments, upon fracture, the glass-based article breaks into multiple fragments, of which 90% or more, or even 100%, have a surface area less than 5%, 2%, or 1% of the surface area of ​​the original glass-based article fragments.

[0071] In one or more embodiments, after chemical strengthening of the glass-based article, the resulting stress profile 317 (and estimated stress profile 340) provides improved fracture resistance. For example, in some embodiments, upon fracture, the glass-based article comprises fragments with an average longest cross-sectional dimension less than or equal to about 2 •t (e.g., 1.8 •t, 1.6 •t, 1.5 •t, 1.4 •t, 1.2 •t, or 1 •t or less).

[0072] In one or more embodiments, the glass-based article can exhibit a pressure of about 0.7 MPa•m. 1 / 2 or greater fracture toughness (K 1C In some cases, the fracture toughness can be approximately 0.8 MPa•m. 1 / 2 Or larger, or about 0.9 MPa•m 1 / 2 Or greater. In some embodiments, the fracture toughness can be around 0.7 MPa•m. 1 / 2 ~ Approximately 1 MPa•m 1 / 2 Within the range.

[0073] In some embodiments, the substrate may also be characterized as having a hardness of about 500 HVN to about 800 HVN, the hardness being determined by a Vickers hardness test under a load of 200 g.

[0074] The glass-based products described in this article can exhibit a J / m value greater than 0 J / m 2 Approximately 20 J / m 2Stretched energy storage within a certain range. In some examples, stretched energy storage can reach approximately 1 J / m³. 2 ~ Approximately 20 J / m 2 Approximately 2 J / m 2 ~ Approximately 20 J / m 2 Approximately 3 J / m 2 ~ Approximately 20 J / m 2 Approximately 4 J / m 2 ~ Approximately 20 J / m 2 Approximately 1 J / m 2 ~ Approximately 19 J / m 2 Approximately 1 J / m 2 ~ Approximately 18 J / m 2 Approximately 1 J / m 2 ~ Approximately 16 J / m 2 Approximately 4 J / m 2 ~ Approximately 20 J / m 2 or about 4 J / m 2 ~ Approximately 18 J / m 2 Within the range. The tensile energy storage can be calculated by integrating the elastic energy storage Σ in the tensile region with respect to the thickness t of each unit region of the specimen using equation (2): Σ=0.5σ 2 t / E (2), Where σ is stress and E is Young's modulus.

[0075] More specifically, the stretched energy storage is calculated using the following equation (3): Stretching energy storage (J / m) 2 =1-ν / 2E∫σ^2dt (3) Where n is Poisson's ratio, E is the elastic modulus, and the integral is performed only over the tensile region.

[0076] In one or more embodiments, glass-based articles exhibit improved surface strength when subjected to the Abrasion Ring-on-Ring (AROR) test. The strength of a material is defined as the stress at which fracture occurs. The A-ROR test is a method for measuring the surface strength of planar glass specimens, and ASTM C1499-09 (2013), entitled "Standard Test Method for Monotonic Equibiaxial Flexural Strength of Advanced Ceramics at Ambient Temperature," provides the basis for the Abrasion Ring-on-Ring (AROR) test method described herein. The contents of ASTM C1499-09 are incorporated herein by reference in their entirety. In one embodiment, prior to the ring stacking test, the glass specimen is abraded with silicon carbide (SiC) particles of size 90. The particles are delivered to the glass specimen using the methods and equipment described in Appendix A2 (titled "Abrasion Procedures") of ASTM C158-02 (2012), entitled "Standard Test Methods for Strength of Glass by Flexure (Determination of Modulus of Rupture)". The specific contents of ASTM C158-02 and Appendix 2 are incorporated herein by reference in their entirety.

[0077] Prior to the ring stacking test, the glass substrate was abraded according to ASTM C158-02, Appendix 2, to standardize and / or control the surface defects of the specimen using the equipment described in Figure A2.1 of ASTM C158-02. Typically, the abrasive material was abraded onto surface 110 of the glass substrate using an air pressure of 304 kPa (44 psi) at a load of 15 psi; although in the examples below, the abrasive material was abraded onto surface 110 at loads of 25 psi and 45 psi. After establishing the airflow, a 5 cm... 3 The abrasive material was poured into the funnel, and the sample was sandblasted for 5 seconds after the abrasive material was introduced.

[0078] For the ring-on-ring test, at least one such Figure 4 The glass substrate with the wear surface 410 shown was placed between two concentric rings of different sizes to determine the isoaxial bending strength (i.e., the maximum stress that the material can maintain when subjected to bending between two communicating rings), as well as... Figure 4As shown. In the wear ring stacked structure 400, the worn glass substrate 410 is supported by a support ring 420 having a diameter D2. A force F is applied to the surface of the glass substrate through a load ring 430 with a diameter D1 using a load element (not shown).

[0079] The diameter ratio D1 / D2 of the load ring to the support ring can be in the range of about 0.2 to about 0.5. In some embodiments, D1 / D2 is about 0.5. The load ring and support rings 130, 120 should be concentrically aligned, not exceeding 0.5% of the support ring diameter D2. The load element used for testing should be accurate to within ±1% of any load within the selected range. In some embodiments, the test is performed at a temperature of 23±2°C and a relative humidity of 40±10%.

[0080] For the design of the fixing device, the radius r of the protruding surface of the load ring 430 satisfies h / 2 ≤ r ≤ 3h / 2, where h is the thickness of the glass substrate 410. The load ring and support rings 430, 420 are typically made of hardened steel with a hardness HRc > 40. The ROR fixing device is commercially available.

[0081] The target failure mechanism for the ROR test is to observe the fracture of the glass substrate 410 originating from the surface 430a within the load ring 430. Failures occurring outside this region (i.e., between the load ring 430 and the support ring 420) are ignored in the data analysis. However, because the glass substrate 410 is thin and has high strength, large deflections exceeding half the specimen thickness h are sometimes observed. Therefore, it is not surprising to observe a high proportion of failures originating below the load ring 430. Stress cannot be accurately calculated without knowing the stress development and failure origin within and below the ring for each specimen (collectively referred to as strain gauge analysis). Therefore, the AROR test focuses on the peak load at failure as a measurement feedback.

[0082] The strength of glass-based products depends on the presence of surface defects. However, the probability of a defect of a given size cannot be accurately predicted because the strength of glass is statistically inherent. Therefore, a probability distribution is typically used as a statistical representative of the obtained data.

[0083] In some embodiments, the strengthened glass-based articles described herein have a surface or isoaxial flexural strength of at least 20 kgf to about 30 kgf, a result determined by a wear ring stacking test that wears the surface under a load of 25 psi or even 45 psi. In other embodiments, the surface strength is at least 25 kgf, and in still other embodiments, at least 30 kgf.

[0084] In some embodiments, the reinforced glass substrate described herein can be characterized by its performance in the Inverted Ball on Sandpaper (IBoS) test. The IBoS test is a dynamic component-level test that simulates the primary mechanisms of failure resulting from damage introduction and bending that typically occur in glass substrates used in mobile or handheld electronic devices, such as... Figure 36 As illustrated. At the scene, damage is introduced ( Figure 37 (a) occurs on the top surface of the glass-based article. The fracture begins on the top surface of the glass-based article, and the damage penetrates into the glass-based article. Figure 37 (b) or, the fracture originates from the bend on the top surface or spreads from the interior portion of the glass-based article ( Figure 37 (c) The IBoS test is designed to simultaneously introduce damage to the glass surface and apply bending under dynamic load. In some cases, when compressive stress is included, glass-based articles exhibit improved drop performance compared to the same glass-based article without compressive stress.

[0085] An IBoS testing device is schematically shown in Figure 36The apparatus 500 includes a test frame 510 and a ball 530. The ball 530 is a rigid 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 from a predetermined height h onto the glass substrate sample 518. The test frame 510 includes a solid base 512, which comprises a hard, rigid material, such as granite. A plate 514 with an abrasive material on its surface is placed on the upper surface of the solid base 512 with the abrasive material surface facing upwards. In some embodiments, the plate 514 is sandpaper with a 30-grit surface, while in other embodiments, it is sandpaper with a 180-grit surface. The glass substrate sample 518 is fixed above the plate 514 using a sample holder 515, such that an air gap 516 exists between the glass substrate sample 518 and the plate 514. An air gap 516 between the plate 514 and the glass-based specimen 518 allows the glass-based specimen 518 to bend and flex against the abraded surface of the plate 514 after being impacted by the ball 530. In one embodiment, all corners of the glass-based specimen 518 are clamped to ensure that bending occurs only at the point of impact with the ball, thereby ensuring repeatability. In some embodiments, the specimen holder 514 and the test fixture 510 are varied to accommodate specimen thicknesses up to about 2 mm. The air gap 516 is in the range of about 50 μm to about 100 μm. The air gap 516 is varied to be adjusted for different material hardness (Young's modulus, Emod), but also for elastic modulus and specimen thickness. Adhesive tape 520 may be used to cover the upper surface of the glass-based specimen to collect fragments generated during a fracture event of the glass-based specimen 518 after being impacted by the ball 530.

[0086] Various materials can be used as abrasives. In one specific 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 with considerable hardness and / or sharpness. In some embodiments, 30-grit sandpaper can be used, thus having a more uniform surface morphology than concrete or asphalt, and a grit size and sharpness capable of producing the desired level of surface damage to the specimen.

[0087] In one aspect, a method 600 for performing IBoS testing using the aforementioned device 500 is shown in... Figure 38 In step 610, the glass-based product sample ( Figure 36The glass substrate specimen 518 (218) is placed in the test holder 510 and fixed in the specimen holder 515, such that an air gap 516 is formed between the glass substrate specimen 518 and the plate 514 with the worn surface. Method 600 assumes that the plate 514 with the worn surface has been placed in the test holder 510. However, in some embodiments, the method may include placing the plate 514 in the test holder 510 with the surface of the worn material facing upward. In some embodiments (step 610a), adhesive tape 520 is applied to the upper surface of the glass substrate specimen 518 before fixing it in the specimen holder 510.

[0088] In step 520, a solid ball 530 of predetermined mass and size is dropped from a predetermined height h onto the upper surface of the glass-based article sample 518, such that the ball 530 impacts the upper surface (or the adhesive tape 520 fixed to the upper surface) approximately at the center of the upper surface (i.e., within 1 mm, 3 mm, 5 mm, or 10 mm of the center). After the impact in step 520, the degree of damage to the glass-based article sample 518 is determined (step 630). As described above, here, the term "fracture" refers to a crack propagating across the entire thickness and / or the entire surface of the substrate when it is dropped or impacted by an object.

[0089] In method 600, the plate 518 with the worn surface can be replaced after each drop to avoid the “aging” effect that has been observed in drop test surfaces that have been reused in other types of materials, such as concrete or asphalt.

[0090] Method 600 typically uses various predetermined drop heights h and increments. For example, a minimum drop height (e.g., about 10–20 cm) can be used to begin the test. Then, for a successful drop, the height can be increased in fixed or variable increments. Once the glass-based specimen 518 breaks or fractures, the test described in Method 600 is stopped (step 631). Alternatively, if the drop height reaches the maximum drop height (e.g., about 100 cm) without fracture, the drop test of Method 300 is also stopped, or step 520 can be repeated at the maximum height until fracture occurs.

[0091] In some embodiments, the IBoS test of method 600 is performed only once for each glass substrate specimen 518 at each predetermined height h. However, in other embodiments, each specimen is tested multiple times at each height.

[0092] If the glass-based product sample 518 has already fractured ( Figure 38If, in step 631, the IBoS test according to method 600 is terminated (step 640), then if no breakage due to the falling ball is observed at the predetermined drop height (step 632), the drop height is increased in predetermined increments (e.g., 5, 10, or 20 cm) (step 634), and steps 620 and 630 are repeated until specimen breakage is observed (631) or the maximum test height is reached (636) without specimen breakage. When step 631 or 636 is reached, the test according to method 600 is terminated.

[0093] When the above-described Inverted Ball on Sandpaper (IBoS) test is performed, the glass-based articles described herein have a survival rate of at least about 60% when the ball is dropped from a height of 100 cm onto the glass surface. For example, a glass-based article is described as having a 60% survival rate when dropped from a given height if, when dropped from a specified height (here, 100 cm), three out of five identical (or nearly identical) specimens (i.e., having substantially the same composition and, after strengthening, substantially the same compressive stress and compressive depth or compressive stress layer depth, as described above) survive the IBoS drop test without fracture. In other embodiments, the survival rate of the strengthened glass-based article in the 100 cm IBoS test is at least about 70%, in other embodiments at least about 80%, and in other embodiments at least about 90%. In other embodiments, the survival rate of the strengthened glass-based article dropped from a height of 100 cm in the IBoS test is at least about 60%, in other embodiments at least about 70%, in other embodiments at least about 80%, and in other embodiments at least about 90%. In one or more embodiments, the survival rate of the strengthened glass-based article dropped from a height of 150 cm in the IBoS test is at least about 60%, in other embodiments at least about 70%, in other embodiments at least about 80%, and in other embodiments at least about 90%.

[0094] To determine the survival rate of glass-based articles when dropped from a predetermined height using the IBoS test method and equipment described above, at least five identical (or nearly identical) glass-based article specimens (i.e., having approximately the same composition and, if strengthened, having approximately the same compressive stress and compressive depth or layer depth) were tested, although multiple specimens (e.g., 10, 20, 30, etc.) could be tested to improve the reliability of the test results. Each specimen was dropped once from a predetermined height (e.g., 100 cm or 150 cm), or dropped from an increasing height until the predetermined height without fracture, and then visually inspected (i.e., with the naked eye) for fracture (crack formation and propagation across the entire thickness and / or surface of the specimen). If no fracture was observed after dropping from the predetermined height, the specimen was considered to have "survived" the drop test; if fracture was observed when the specimen was dropped from a height less than or equal to the predetermined height, the specimen was considered to have "failed" (or "did not survive"). The percentage of specimens surviving the drop test out of the total number of specimens was determined as the survival rate. For example, if 7 out of a set of 10 samples do not break when dropped from a predetermined height, the survival rate of the glass is 70%.

[0095] The glass-based articles described herein may be transparent or opaque. In one or more embodiments, the glass-based articles may have a thickness of about 1 mm or less and exhibit a transmittance of about 88% or greater in the wavelength range of about 380 nm to about 780 nm. In another embodiment, the glass-based articles may have a thickness of about 1 mm or less and exhibit a transmittance of about 10% or less in the wavelength range of about 380 nm to about 780 nm.

[0096] Glass-based products can also be essentially white. For example, glass-based products can exhibit an L-shape under the CIE light source F02. The value is approximately 88 or greater, a The value is in the range of approximately -3 to approximately +3, and b CIELAB color space coordinates with values ​​ranging from approximately -6 to approximately +6. Alternatively, glass-based products can exhibit L under a CIE illuminator F02. The value is approximately 40 or less, a The value is in the range of approximately -3 to approximately +3, and b CIELAB color space coordinates with values ​​ranging from approximately -6 to approximately +6. These color space coordinates can also be found under other CIE light sources (such as D65).

[0097] The choice of substrate is not specifically limited. In some examples, glass-based articles can be described as having high cation diffusivity for ion exchange. In one or more embodiments, the glass or glass-ceramic has a first ion exchange capacity, i.e., greater than 500 micrometers.2 / hour, or can be characterized as greater than 450 micrometers at 460°C. 2 / hour diffusion rate.

[0098] At a certain temperature, the diffusivity is calculated using the following formula (4): Diffusion rate = DOL^2 / 5.6 T(4), Where DOL is the depth of the ion exchange layer, and T is the ion exchange time required to reach DOL.

[0099] Glass-based articles may comprise amorphous substrates, crystalline substrates, or combinations thereof (e.g., glass-ceramic substrates). In one or more embodiments, the glass-based article substrate (prior to the chemical strengthening described herein) may comprise a glass having the following composition, in mole percentage (mol%): The composition contains SiO2 in an amount ranging from about 40 to about 80; Al2O3 in an amount ranging from about 10 to about 30; B2O3 in an amount ranging from about 0 to about 10; R2O in an amount ranging from about 0 to about 20; and RO in an amount ranging from about 0 to about 15. In some examples, the composition may contain one or both of ZrO2 in an amount ranging from about 0 mol% to about 5 mol% and P2O5 in an amount ranging from about 0 to about 15 mol%. TiO2 may be present in an amount ranging from about 0 mol% to about 2 mol%.

[0100] In some embodiments, the glass composition may contain SiO2 in the following mole percent ranges: about 45 to about 80, about 45 to about 75, about 45 to about 70, about 45 to about 65, about 45 to about 60, about 45 to about 65, about 45 to about 65, about 45 to about 65, about 50 to about 70, about 55 to about 70, about 60 to about 70, about 70 to about 75, about 70 to about 72, or about 50 to about 65.

[0101] In some embodiments, the glass composition may contain Al2O3 in the following ranges in mol%: about 5 to about 28, about 5 to about 26, about 5 to about 25, about 5 to about 24, about 5 to about 22, about 5 to about 20, about 6 to about 30, about 8 to about 30, about 10 to about 30, about 12 to about 30, about 14 to about 30, about 16 to about 30, about 18 to about 30, about 18 to about 28, or about 12 to about 15.

[0102] In one or more embodiments, the glass composition may contain B2O3 in the following mol% ranges: about 0 to about 8, about 0 to about 6, about 0 to about 4, about 0.1 to about 8, about 0.1 to about 6, about 0.1 to about 4, about 1 to about 10, about 2 to about 10, about 4 to about 10, about 2 to about 8, about 0.1 to about 5, or about 1 to about 3. In some examples, the glass composition may be substantially free of B2O3. As used herein, the term "substantially free" in relation to a component of a glass composition means that the component was not actively or intentionally added to the glass composition during the initial formulation or subsequent ion exchange process, but the component may be present as an impurity. For example, when a component is present in an amount less than about 0.10001 mol%, the glass may be described as substantially free of that component.

[0103] In some embodiments, the glass composition may comprise one or more metal oxides, such as MgO, CaO, and ZnO. In some embodiments, the total amount of one or more alkaline earth metal oxides may be non-zero and not more than about 15 mol%. In one or more specific embodiments, the total amount of any one of the alkaline earth metal oxides may be non-zero and not more than about 14 mol%, not more than about 12 mol%, not more than about 10 mol%, not more than about 8 mol%, not more than about 6 mol%, not more than about 4 mol%, not more than about 2 mol%, or not more than about 1.5 mol%. In some embodiments, the total amount of one or more alkaline earth metal oxides, expressed as mol%, may be in the range of about 0.1–10, about 0.1–8, about 0.1–6, about 0.1–5, about 1–10, about 2–10, or about 2.5–8. The amount of MgO may 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%. The amount of CaO may be in the range of about 0 mol% to about 2 mol%. In one or more embodiments, the glass composition may contain MgO and may be substantially free of CaO and ZnO. In one variation, the glass composition may contain either CaO or ZnO and may be substantially free of other MgO, CaO, and ZnO. In one or more specific embodiments, the glass composition may contain only two of the alkaline earth metal oxides MgO, CaO, and ZnO and may be substantially free of a third of these alkaline earth metal oxides.

[0104] The total amount of alkali metal oxide R2O in the glass composition, expressed as mole percent, is in the following ranges: 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 9 to about 20, about 10 to about 20, about 6 to about 13, or about 8 to about 12.

[0105] In one or more embodiments, the glass composition comprises Na2O in the following ranges: about 0 mol% to about 18 mol%, about 0 mol% to about 16 mol%, or about 0 mol% to about 14 mol%, about 0 mol% to about 10 mol%, about 0 mol% to about 5 mol%, about 0 mol% to about 2 mol%, about 0.1 mol% to about 6 mol%, about 0.1 mol% to about 5 mol%, about 1 mol% to about 5 mol%, about 2 mol% to about 5 mol%, or about 10 mol% to about 20 mol%.

[0106] In some embodiments, the amounts of Li₂O and Na₂O are controlled in specific quantities or ratios to balance formability and ion exchangeability. For example, as the amount of Li₂O increases, the liquidus viscosity can decrease, rendering some forming methods unusable, but as described herein, these glass compositions are ion-exchanged to a deeper DOC level. The amount of Na₂O can alter the liquidus viscosity and also inhibit ion exchange to a deeper DOC level.

[0107] In some embodiments, the glass composition may contain K2O in the following ranges: 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 alternative embodiments, as defined herein, the glass composition may be substantially free of K2O.

[0108] In one or more embodiments, the glass composition may contain Li₂O in the following ranges: 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 the following ranges: 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 alternative embodiments, as defined herein, the glass composition may be substantially free of Li₂O.

[0109] In one or more embodiments, the glass composition may contain Fe2O3. In these embodiments, Fe2O3 may be present in amounts of 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 in all ranges and subranges thereof. In one or more alternative embodiments, as defined herein, the glass composition may be substantially free of Fe2O3.

[0110] In one or more embodiments, the glass composition may contain ZrO2. In these embodiments, ZrO2 may be present in amounts 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 in all ranges and subranges thereof. In one or more alternative embodiments, as defined herein, the glass composition may be substantially free of ZrO2.

[0111] In one or more embodiments, the glass composition may contain P2O5 in the following ranges: 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 4 mol% to about 8 mol%, or about 5 mol% to about 8 mol%. In some examples, the glass composition may be substantially free of P2O5.

[0112] In one or more embodiments, the glass composition may contain TiO2. In these embodiments, TiO2 may be present in amounts 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 alternative embodiments, as defined herein, the glass composition may be substantially free of TiO2. In some embodiments, TiO2 is present in amounts ranging from about 0.1 mol% to about 6 mol%, or from about 0.1 mol% to about 4 mol%.

[0113] In some embodiments, the glass composition may comprise various compositional relationships. For example, the glass composition may have a ratio of Li₂O (in mole%) to the total amount of R₂O (in mole%) in the range of about 0.5 to about 1. In some embodiments, the glass composition may have a difference between the total amount of R₂O (in mole%) and the amount of Al₂O₃ (in mole%) in the range of about -5 to about 0. In some examples, the glass composition may have an R₂O content in the range of about 0 to about 3.x The difference between the total amount of O (in mole %) and the amount of Al2O3. Glass compositions of one or more embodiments may exhibit a ratio of MgO (in mole %) to the total amount of RO (in mole %) in the range of about 0 to about 2.

[0114] In some embodiments, the glass composition may be substantially free of nucleating agents. Typical examples of nucleating agents are TiO2, ZrO2, etc. Nucleating agents can be described by their ability as a component in the glass to initiate the formation of microcrystals within the glass.

[0115] In some embodiments, the composition for the glass substrate may include 0 to 2 mol% of at least one clarifying agent selected from the group consisting of Na₂SO₄, NaCl, NaF, NaBr, K₂SO₄, KCl, KF, KBr, and SnO₂. The glass composition according to one or more embodiments may also contain SnO₂ in the following ranges: 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 described herein may be substantially free of As₂O₃ and / or Sb₂O₃.

[0116] In one or more embodiments, the composition may specifically comprise: 62 mol% to 75 mol% SiO2; 10.5 mol% to about 17 mol% Al2O3; 5 mol% to about 13 mol% Li2O; 0 mol% to about 4 mol% ZnO; 0 mol% to about 8 mol% MgO; 2 mol% to about 5 mol% TiO2; 0 mol% to about 4 mol% B2O3; 0 mol% to about 5 mol% Na2O; 0 mol% to about 4 mol% K2O; 0 mol% to about 2 mol% ZrO2; 0 mol% to about 7 mol% P2O5; 0 mol% to about 0.3 mol% Fe2O3; 0 mol% to about 2 mol% MnOx; and 0.05 mol% to about 0.2 mol% SnO2. In one or more embodiments, the composition may comprise: 67 mol% to about 74 mol% SiO2; 11 mol% to about 15 mol% Al2O3; 5.5 mol% to about 9 mol% Li2O; 0.5 mol% to about 2 mol% ZnO; 2 mol% to about 4.5 mol% MgO; 3 mol% to about 4.5 mol% TiO2; 0 mol% to about 2.2 mol% B2O3; 0 mol% to about 1 mol% Na2O; 0 mol% to about 1 mol% K2O; 0 mol% to about 1 mol% ZrO2; 0 mol% to about 4 mol% P2O5; 0 mol% to about 0.1 mol% Fe2O3; 0 mol% to about 1.5 mol% MnOx; and 0.08 mol% to about 0.16 mol% SnO2. In one or more embodiments, the composition may comprise: 70 mol% to 75 mol% SiO2; 10 mol% to about 15 mol% Al2O3; 5 mol% to about 13 mol% Li2O; 0 mol% to about 4 mol% ZnO; 0.1 mol% to about 8 mol% MgO; 0 mol% to about 5 mol% TiO2; 0.1 mol% to about 4 mol% B2O3; 0.1 mol% to about 5 mol% Na2O; 0 mol% to about 4 mol% K2O; 0 mol% to about 2 mol% ZrO2; 0 mol% to about 7 mol% P2O5; 0 mol% to about 0.3 mol% Fe2O3; 0 mol% to about 2 mol% MnOx; and 0.05 mol% to about 0.2 mol% SnO2.

[0117] In one or more embodiments, the composition may comprise: 52 mol% to about 63 mol% SiO2; 11 mol% to about 15 mol% Al2O3; 5.5 mol% to about 9 mol% Li2O; 0.5 mol% to about 2 mol% ZnO; 2 mol% to about 4.5 mol% MgO; 3 mol% to about 4.5 mol% TiO2; 0 mol% to about 2.2 mol% B2O3; 0 mol% to about 1 mol% Na2O; 0 mol% to about 1 mol% K2O; 0 mol% to about 1 mol% ZrO2; 0 mol% to about 4 mol% P2O5; 0 mol% to about 0.1 mol% Fe2O3; 0 mol% to about 1.5 mol% MnOx; and 0.08 mol% to about 0.16 mol% SnO2.

[0118] Other exemplary compositions of glass-based articles before chemical strengthening as described herein are shown in Table 1.

[0119] Table 1: Exemplary compositions before chemical fortification.

[0120] In glass-based articles containing glass ceramics, the crystalline phase may include β-spodumene, rutile, zinc spinel, or other known crystalline phases and combinations thereof.

[0121] Glass-based articles can be substantially planar, but other embodiments may use curved or otherwise shaped or sculpted substrates. In some examples, glass-based articles may have 3D or 2.5D shapes. Glass-based articles can be substantially optically clear, transparent, and do not scatter light. Glass-based articles may have a refractive index in the range of about 1.45 to about 1.55. As used herein, refractive index values ​​are relative to a wavelength of 550 nm.

[0122] Additionally or alternatively, for aesthetic and / or functional reasons, the thickness of a glass-based article may be constant or variable along one or more of its dimensions. For example, the edges of a glass-based article may be thicker than areas closer to the center of the article. The length, width, and thickness dimensions of a glass-based article may also be varied depending on its application or use.

[0123] Glass-based articles can be characterized by their forming method. For example, glass-based articles can be characterized as float-forming (i.e., formed by float process), drawable, and can be specifically characterized as fusion-forming or slot-drawing (i.e., formed by drawable methods such as fusion drawing or slot drawing).

[0124] Float glass-based articles are characterized by their smooth surface and uniform thickness, and can be manufactured by floating molten glass on a bed of molten metal (typically tin). In one exemplary method, molten glass is fed onto the surface of a bed of molten tin to form a floating glass ribbon. As the glass ribbon flows along the tin bath, the temperature gradually decreases until the glass ribbon solidifies into a solid glass-based article that can be lifted from the tin onto a roller. Once removed from the bath, the glass-based article can be further cooled and annealed to reduce internal stress. In cases where the glass-based article is a glass-ceramic, the glass-based article formed by the float process can be ceramicized to generate one or more crystalline phases.

[0125] The down-drawing process can produce glass-based articles with uniform thickness and relatively intact surfaces. Because the average flexural strength of a glass-based article is controlled by the amount and size of surface cracks, the intact surface with minimal contact has higher initial strength. When this high-strength glass-based article is further strengthened (e.g., chemically strengthened), the resulting strength can exceed that of glass-based articles whose surfaces have already been ground and polished. Down-drawn glass-based articles can be drawn to thicknesses of less than approximately 2 mm. Furthermore, down-drawn glass-based articles have very flat, smooth surfaces that can be used in their final applications without the need for expensive grinding and polishing. In cases where the glass-based article is a glass-ceramic, it can be ceramicized to generate one or more crystalline phases.

[0126] For example, fusion drawing uses a drawing groove having channels for receiving molten glass raw materials. Weirs with open tops are located on both sides of the channel along its length. When the channel is filled with molten material, molten glass overflows from the weirs. Under gravity, the molten glass flows down from the outer surface of the drawing groove in the form of two flowing glass films. These outer surfaces of the drawing groove extend downwards and inwards so that they converge at the lower edge of the drawing groove. The two flowing glass films converge and fuse at this edge to form a single flowing glass substrate. The advantage of fusion drawing is that, since the two glass films overflowing from the channel are fused together, neither outer surface of the resulting glass substrate comes into contact with any part of the equipment. Therefore, the surface properties of the glass substrate manufactured by fusion drawing are not affected by such contact. In the case where the glass substrate is glass-ceramic, the glass substrate formed by fusion can be ceramicized to generate one or more crystalline phases.

[0127] Slot drawing differs from fusion drawing. In slot drawing, molten raw glass is supplied to a drawing container. The bottom of the drawing container has an open slit with a nozzle extending along its length. The molten glass flows through this slit / nozzle, drawn downwards as a continuous glass substrate and into an annealing zone. When the glass substrate is glass-ceramic, it can be ceramicized to generate one or more crystalline phases.

[0128] In some embodiments, glass-based articles can be formed using the thin roll forming process described in the following documents: 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. 2015,002,7169, entitled "Methods and Apparatus For Forming A Glass Ribbon"; and U.S. Patent Publication No. 2005,009,9618, entitled "Apparatus and Method for Forming Thin Glass Articles," the contents of which are incorporated herein by reference in their entirety. Specifically, glass-based articles can be formed by: feeding a vertical stream of molten glass, shaping the supplied molten glass or glass-ceramic stream using a pair of forming rollers with a surface temperature maintained at about 500°C or higher or about 600°C or higher to form a glass ribbon with a forming thickness, and setting the dimensions of the formed glass ribbon using a pair of dimension setting rollers with a surface temperature maintained at about 400°C or lower to produce a dimensionally set glass ribbon with a desired thickness less than the forming thickness and desired thickness uniformity. Apparatus for forming glass ribbons may include: a glass feeding device for supplying a molten glass feed stream; a pair of forming rollers with a surface temperature maintained at about 500°C or higher, the forming rollers being spaced apart from each other to define a glass forming gap between the forming rollers, the glass forming gap being located vertically below the glass feeding device for receiving the molten glass feed stream and thinning the molten glass feed stream between the forming rollers to form a formed glass ribbon with a forming thickness; and a pair of dimensional setting rollers with a surface temperature maintained at about 400°C or lower, the dimensional setting rollers being spaced apart from each other to define a glass dimensional setting gap between the dimensional setting rollers, the glass dimensional setting gap being located vertically below the forming rollers for receiving the formed glass ribbon and thinning the formed glass ribbon to produce a dimensionally set glass ribbon with a desired thickness and desired thickness uniformity.

[0129] In some cases, thin-rolling processes can be used when the viscosity of the glass does not allow for fusion or slot drawing. For example, when the glass has a liquidus viscosity of less than 100 kP, thin-rolling can be used to form glass-based products.

[0130] Glass-based products can be acid-polished or otherwise treated to eliminate or reduce the effects of surface defects.

[0131] Another aspect of this 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 1 mm or less; and generating a stress profile in the glass-based substrate as described herein to provide a fracture-resistant glass-based article. In one or more embodiments, generating the stress profile includes ion-exchanging a plurality of alkali metal ions into the glass-based substrate to form a non-zero alkali metal oxide concentration varying along most or all of the thickness (as described herein). In one example, generating the stress profile includes immersing the glass-based substrate in a Na-containing solution at a temperature of about 350°C or higher (e.g., about 350°C to about 500°C). + K + 、Rb + Cs + Alternatively, a combination of nitrates may be immersed in a molten salt bath. In one example, the molten bath may contain NaNO3 and may have a temperature of about 485°C. In another example, the bath may contain NaNO3 and may have a temperature of about 430°C. The glass substrate may be immersed in the bath for about 2 hours or longer, but not exceeding 48 hours (e.g., about 12 hours to about 48 hours, about 12 hours to about 32 hours, about 16 hours to about 32 hours, about 16 hours to about 24 hours, or about 24 hours to about 32 hours).

[0132] In some embodiments, the method may include chemically strengthening or ion-exchanging the glass substrate using a series of immersion steps in more than one bath. For example, two or more baths may be used consecutively. The composition of one or more baths may include a single metal (e.g., Ag). + Na + K + 、Rb + 、or Cs + Alternatively, the metals may be combined in the same bath. When using more than one bath, these baths may have the same or different compositions and / or temperatures. The immersion times in each bath may be the same or varied to provide the stress profiles described.

[0133] In one or more embodiments, a second or subsequent bath may be used to generate a larger surface area CS. In some examples, the method includes immersing a glass substrate in a second or subsequent bath to generate a larger surface area CS without significantly affecting the chemical layer depth and / or DOC. In these embodiments, the second or subsequent bath may contain a single metal (e.g., KNO3 or NaNO3) or a mixture of metals (KNO3 or NaNO3). The temperature of the second or subsequent bath may be adjusted to generate a larger surface area CS. In some embodiments, the immersion time of the glass substrate in the second or subsequent bath may also be adjusted to generate a larger surface area CS without affecting the chemical layer depth and / or DOC. For example, the immersion time in the second or subsequent bath may 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).

[0134] In one or more alternative embodiments, the method may include one or more heat treatment steps that can be used in combination with the ion exchange process described herein. The heat treatment includes subjecting the glass substrate to heat treatment to obtain a desired stress profile. In some embodiments, the heat treatment includes annealing, tempering, or heating the glass substrate to a temperature in the range of about 300°C to about 600°C. The heat treatment may last from 1 minute to about 18 hours. In some embodiments, the heat treatment may be used after one or more ion exchange treatments or between multiple ion exchange treatments.

[0135] Example Various embodiments are further illustrated by the following examples. In these embodiments, the embodiment is referred to as a "substrate" before strengthening. After strengthening, the embodiment is referred to as an "article" or "glass-based article".

[0136] Example 1 A glass-ceramic substrate having a nominal composition as shown in Table 2 below is provided. The glass-ceramic substrate has a thickness of 0.8 mm and contains crystalline phase aggregates comprising a β-spodumene solid solution as the main crystalline phase and one or more secondary crystalline phases, including rutile. The glass-ceramic substrate is immersed in a molten salt bath containing NaNO3 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 NaNO3 at a temperature of 430°C for 2 hours (comparative condition D) to form a glass-ceramic article.

[0137] Table 2: Composition of the glass-ceramic substrate of Example 1 before chemical strengthening.

[0138] The stress curves of glass-ceramic products were measured using a microprobe and are shown below. Figure 5 In the middle. For example Figure 5 As shown, when a higher temperature bath is used (i.e., conditions A to C), the Na content is reduced across almost the entire thickness of the product. + All ions were ion-exchanged. In these glass-ceramics, Na₂O was present in the CT region at a concentration of approximately 1.2 mol% or greater. Glass-ceramics subjected to ion exchange in a lower temperature bath (comparative condition D) exhibited stress curves similar to known stress curves.

[0139] Example 2 Glass articles were provided by chemically strengthening glass substrates with the same composition as shown in Table 2 but with an amorphous structure (and no crystalline phase) by immersing them in a molten salt bath containing 100% NaNO3 at a temperature of approximately 430°C for various times. The DO (displacement) and maximum CT (coarse-field precipitate) values ​​of the glass articles were measured using a Scattered Amplitude Polarizer (SCALP). Figure 6 As shown, DOC and maximum CT increase with increasing immersion or ion exchange time. The maximum CT value was observed after immersion of the glass for approximately 16 hours.

[0140] The stress curve of the glass product in Example 2 was measured using SCALP and is shown below. Figure 7 In the figure, the upper part of the x-axis, representing the normal stress value, is the CT layer, while the lower part, representing the negative stress value, is the CS value. The stress curve of the chemically strengthened glass exhibits the maximum CT value (i.e., 175 MPa) and a parabolic shape, essentially devoid of a linear portion in the 100-micrometer depth direction. The surface CS, measured using SCALP, is approximately 410 MPa. Therefore, the ratio of the maximum CT to the surface CS in Example 2 is approximately 0.4375.

[0141] Example 3 For comparison, the glass-ceramic substrates of Example 1 and the glass substrates of Example 2, each with a thickness of about 0.8 mm, were chemically strengthened by immersing them in a NaNO3 molten salt bath at a temperature of 350°C for 3.5 hours (Examples 3A and 3B, respectively). Figure 8 The stress curves of the resulting glass-ceramic articles shown resemble the error function (erfc) or quasi-linear shape. Furthermore, the CS depth of the layer is shallower than the depth (or chemical ion exchange depth) of alkali metal ions exchanged into the glass or glass-ceramic.

[0142] When the glass-ceramic substrates of Example 1 and Example 2, each with a thickness of approximately 0.8 mm, were chemically strengthened as described above by immersing them in a NaNO3 molten salt bath at a temperature of 430°C for 24 hours (Examples 3C and 3D, respectively), the resulting glass-based articles exhibited the following characteristics: Figure 9 The concentration curves of the metal oxides shown are obtained using EPMA. These metal oxide concentration curves are parabolic in shape and show that Na... + Ion exchange occurs throughout the entire thickness. Chemical profiles were measured using EMPA, showing a chemical depth of Na₂O equal to or greater than 400 micrometers. Furthermore, Na₂O is present throughout the entire thickness at a concentration of approximately 1 mol% or greater, including in the CT layer. The glass-ceramic articles obtained in Example 3D exhibited excellent fracture resistance in drop tests where these glass-ceramic substrates were incorporated into identical mobile phone casings. Specifically, five samples from Example 3D were assembled into a mobile phone device and then repeatedly dropped onto sandpaper from a height of 50 cm. If a sample survived a drop from one height, it was dropped again from an increased height until it broke; this height was recorded as the failure height of the sample. Figure 9A In the example 3D, an average failure height of 172.5 cm is observed.

[0143] Figure 10 Stress profiles are shown for glass substrates chemically strengthened according to known processes and glass substrates chemically strengthened according to the methods described herein. Figure 10 As shown, the stress profile of the glass-based article described herein has a shape that substantially does not contain linear segments (having a length or absolute depth greater than about 50 micrometers) and exhibits a DOC of about 0.2•t, while known stress profiles exhibit a substantially linear portion at a depth of about 0.1 mm to about 0.7 mm (total length about 0.6 mm or 600 micrometers). Known stress profiles also exhibit lower CT values ​​and lower DOC.

[0144] Example 4 Glass substrates having the compositions shown in Table 2 (each approximately 1 mm thick) were chemically strengthened by immersing them in a first molten salt bath of NaNO3 at 430°C for 24 hours. One glass substrate article (Example 4A) underwent no additional strengthening steps. Three glass substrate articles were subjected to a second strengthening step by immersing them in a second molten salt bath of KNO3 at approximately 430°C for 0.75 hours, 4 hours, or 8 hours (Examples 4B, 4C, and 4D, respectively). The stress profiles of the resulting glass substrate articles, measured using SCALP, are shown below. Figure 11The x-axis represents the depth or thickness of the glass substrate, and the y-axis represents the stress. The normal stress value is the CT value, and the negative stress value is the CS value. The spatial resolution of the instrument makes it impossible to measure the CS related to the second KNO3 ion exchange step. The glass substrates of Examples 4A and 4B exhibit similar curves. The glass substrates of Examples 4C and 4D exhibit decreasing CT (compared to Examples 4A and 4B) and decreasing CS (compared to Examples 4A and 4B) over time after immersion in the second strengthening step. Examples 4C and 4D also exhibit increased DOC compared to Examples 4A and 4B, and these DOC values ​​are greater than 0.2•t.

[0145] Figure 12 The figures for each embodiment in Examples 4B to 4D are shown in J / m. 2 The tensile energy storage is greater than 15 J / m. 2 The immersion time in the second molten salt bath of KNO3 depends on the immersion time. The tensile energy storage can be calculated using the measured SCALP stress curve data and the above equation (3).

[0146] Figure 13 and 14 The concentration curves of K₂O and Na₂O for each of Examples 4B–4D are shown as a function of depth (in micrometers). Figure 13 As shown, the chemical depth of K2O was 3 micrometers (Example 4B, soaking in a KNO3 bath for 0.75 hours), 6 micrometers (Example 4C, soaking in a KNO3 bath for 4 hours), and 5 micrometers (Example 4D, soaking in a KNO3 bath for 8 hours). Figure 14 As shown, for each of Examples 4B to 4D, Na2O penetrates the entire depth and has a concentration of about 1 mol% or greater along the entire depth of the glass substrate.

[0147] Examples 4E and 4F comprise glass substrates (each with a thickness of approximately 1 mm) having the compositions shown in Table 2. These glass substrates were chemically strengthened by immersing them in a first molten salt bath of NaNO3 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 curves of the glass substrate articles of Examples 4E and 4F are shown together with the stress curves of the comparative Examples 4A, 4C, and 4D. Figure 15 . Figure 16 Shown at a smaller scale with Figure 15 The same figure is used to illustrate the differences in stress curves at or near a depth of 0.5•t.

[0148] Example 5 Glass substrates having the compositions shown in Table 2 (each approximately 1 mm thick) were chemically strengthened by immersing them in a first molten salt bath of NaNO3 at 430°C for 24 hours. One glass substrate (Example 5A) underwent no additional strengthening steps. Two glass substrates underwent a second strengthening step by placing them in a furnace at 390°C and holding them there for approximately 8 hours or 28 hours (Examples 5B-5C, respectively). Four glass substrates underwent a third strengthening step (after any of the first strengthening step and different second strengthening steps) by immersing them in a second molten salt bath of KNO3 at 430°C for 4 hours or 8 hours (Examples 5D-5G). The strengthening steps used for any of Examples 5A-5G are shown in Table 3. The measured CT values ​​are also shown in Table 3.

[0149] Table 3: Enhancement steps of Examples 5A to 5G.

[0150] The stress curves of the obtained glass-based products are shown in Figure 17 The x-axis represents the depth or thickness of the glass substrate, and the y-axis represents the stress. Normal stress values ​​are represented by CT values, and negative stress values ​​by CS values. For example... Figure 17 As shown, DOC increases and CT decreases with increasing duration of the second and / or third heat treatment. Figure 18 and 19 The reduction in DOC and CT is shown more clearly, respectively.

[0151] The glass substrate articles of Examples 5A to 5G were then subjected to puncture tests. In the puncture test, one side of the glass substrate article was attached to adhesive tape, while the opposite exposed side was impacted by a sharp tool and fractured. The number of fragments obtained is related to the tensile energy storage of the glass substrate article. Examples 5A, 5B, and 5D exhibited many fragments (i.e., more than 50 or 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 fractured into many fragments, exhibited a higher CT (greater than about 100 MPa) than Examples 5C, 5E, 5F, and 5G, which had a CT value of about 100 MPa or less.

[0152] Example 6 Chemical strengthening was performed on glass substrates with a nominal composition of 57.5 mol% SiO2, 16.5 mol% Al2O3, 16.7 mol% Na2O, 2.5 mol% MgO, and 6.5 mol% P2O5, and a thickness of approximately 0.4 mm, 0.55 mm, or 1 mm. The thickness and chemical strengthening conditions are shown in Table 4.

[0153] Table 4: Depth and chemical strengthening conditions of Examples 6A-6D.

[0154] Example 6A was immersed in the molten salt bath shown in Table 4 for 4 hours, 8 hours, 16 hours, 32 hours, 64 hours, and 128 hours (Examples 6A-1 to 6A-6). Example 6B was immersed in the molten salt bath shown in Table 4 for 4 hours, 8 hours, 16 hours, 32 hours, 64 hours, and 128 hours (Examples 6B-1 to 6B-6). Example 6C was immersed in the molten salt bath shown in Table 4 for 1 hour, 2 hours, 4 hours, 8 hours, 16 hours, and 32 hours (Examples 6C-1 to 6C-6). Example 6D was immersed in the molten salt bath shown in Table 4 for 4 hours, 8 hours, 16 hours, 32 hours, 64 hours, and 128 hours (Examples 6D-1 to 6D-6). The stress curves of Examples 6A-1 to 6A-6, 6B-1 to 6B-6, 6C-1 to 6C-6, and 6D-1 to 6D-6 are shown in Table 4. Figure 20 , 22 , 24 and 26. exist Figure 20 , 22 In Figures 24 and 26, the x-axis represents the depth or thickness of the glass product, and the y-axis represents the stress. The normal stress value is the CT value, and the negative stress value is the CS value.

[0155] The relationships between CT and DOC values ​​and immersion time in molten salt bath for Examples 6A-1 to 6A-6, 6B-1 to 6B-6, 6C-1 to 6C-6, and 6D-1 to 6D-6 are shown in the figures. Figure 21 , 23 25 and 27.

[0156] Example 7 A glass substrate with a nominal composition as shown in Table 2 and a thickness of approximately 1 mm was chemically strengthened in a molten salt bath containing 100% NaNO3 at a temperature of 430°C. The duration of immersion of the glass substrate in the molten salt bath is shown in Table 5.

[0157] Table 4: Chemical fortification duration (or ion exchange time) of Examples 7A-7G.

[0158] The stress curves of the glass-based articles in Examples 7A to 7G are shown in... Figure 28 Stress curves were measured using SCALP. (For example...) Figure 28 As shown, immersion of the glass substrate in a molten salt bath for 16 hours and 24 hours resulted in the glass substrate exhibiting the highest surface CS value and the highest CT value, respectively; these values ​​are absolute values. A graph showing the changes in CT value and tensile energy storage with ion exchange time is provided. Figure 29 .

[0159] Example 8 Chemical strengthening was performed on glass substrates with nominal compositions shown in Table 2 and a thickness of approximately 0.8 mm for 15 minutes (Comparative Example 8A) and 16 hours (Example 8B) in a molten salt bath containing a mixture of NaNO3 and NaSO4 at a temperature of 500°C. Stress curves of the glass substrates from Examples 8A and 8B are shown in... Figure 30 .like Figure 30 As shown, Comparative Example 8A exhibits a known stress curve, while Example 8B shows a stress curve according to one or more embodiments of the present disclosure. The tensile energy storage of the glass substrate articles of Examples 8A and 8B was calculated in the same manner as in Examples 4B-4D. A graph showing the calculated tensile energy storage versus the measured CT (MPa) was plotted, as shown below. Figure 31 As shown.

[0160] like Figure 31 As shown, at a given CT value, Comparative Example 8A exhibits a significantly greater tensile energy storage than Example 8B (for the same CT value). Specifically, at a CT of approximately 55 MPa, Comparative Example 8A exhibits approximately 8 J / m 2 The stretched energy storage, while Example 8B exhibits approximately 3.5 J / m 2 The tensile energy storage was used to induce fracture in Comparative Example 8A and Example 8B. Example 8B fractured into fewer fragments than Comparative Example 8A, which fractured into a much larger number of fragments. Therefore, it is not intended to limit the theory to suggest that controlling the tensile energy storage provides a way to control or predict the fragmentation pattern of multiple fragments resulting from fracture.

[0161] Chemical strengthening was performed on glass substrates with nominal compositions shown in Table 2 and a thickness of approximately 1 mm for 4 minutes (Comparative Example 8C) and 61.5 hours (Example 8D) in a molten salt bath containing NaNO3 at a temperature of 430°C. Comparative Example 8C exhibited a known stress profile, while Example 8D showed a stress profile according to one or more embodiments of the present disclosure. The tensile energy storage of Examples 8C and 8D was calculated using the same method used in Examples 4B-4D, and its relationship with the measured CT (MPa) was plotted, as shown below. Figure 32 As shown.

[0162] like Figure 32 As shown, at a given CT value, (for the same CT value) Comparative Example 8C exhibits a much larger tensile energy storage than Example 8D. When Comparative Example 8C and Example 8D were fractured, Example 8D fractured into fewer fragments than Comparative Example 8C, while Comparative Example 8C fractured into a much larger number of fragments.

[0163] Example 9 Ion exchange was performed on a glass substrate with 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. The various properties of Examples 9 and 2 are compared in Table 6.

[0164] Table 5: Ion exchange conditions in Example 9.

[0165] Table 6: Comparison of properties between Example 9B and Example 2.

[0166] The stress curve of the glass-based article of Example 9 was measured and the shape described herein was displayed.

[0167] Glass substrates of Examples 2, 6, and Comparative Example 9A, having the same thickness as Example 9, were provided. The glass substrate of Example 2 was subjected to ion exchange for 33 hours in a 100% NaNO3 molten bath at 430°C. Ion exchange of the glass substrate according to Example 6 exhibited a known error function stress curve. Ion exchange of Comparative Example 9A in a 100% NaNO3 molten bath at 390°C for 16 hours also exhibited a known error function stress curve. As used herein, the term "error function stress curve" refers to... Figure 1 Similar stress curves.

[0168] Then, the glass-based articles from Examples 2, 6, 9, and 9A were modified onto the same mobile phone device. The mobile phone device was dropped onto 30-grit sandpaper from increasing heights, starting at 20 cm. If the glass-based article survived a drop from one height (e.g., 20 cm), the phone was dropped again from even higher heights (e.g., 30 cm, 40 cm, 50 cm, etc.). The failure height of the glass-based article is plotted in Example 32, which also shows the average failure height of the samples from Examples 2, 6, and 9, and Comparative Example 9A. Figure 33 As shown, Examples 2 and 9 exhibit failure at much higher drop heights than Examples 6 and Comparative Example 9A. Specifically, Examples 6 and Comparative Example 9A exhibited failures at drop heights of approximately 38 cm and 55 cm, respectively, while Examples 2 and 9 exhibited failures at drop heights of approximately 147 cm and 132 cm, respectively.

[0169] The same mobile phone device was dropped onto 180-grit sandpaper to repeatedly perform the same test on the new sample. The average failure height of Example 6 was 190 cm, Comparative Example 9A was 204 cm, Example 2 was 214 cm, and Example 9 was 214 cm.

[0170] Ion exchange was performed on the glass substrate of Comparative Example 9B, which has 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, and exhibited a known error function stress curve. The A-ROR test, as described above, was performed on the glass substrate samples of Examples 2 and 6 (exhibiting the stress curves described above in the examples herein), Comparative Example 9B, and the glass substrate sample of Example 9, which were ion exchanged according to condition 4 as shown in Table 5.

[0171] Examples 6 and 9, as well as Comparative Example 9B, were worn using loads or pressures of 25 psi and 45 psi, while Example 2 was worn using only a load of 25 psi. AROR data are shown in... Figure 34 .like Figure 34 As shown, Examples 2 and 9 exhibit higher failure loads than Examples 6 and Comparative Example 9B.

[0172] Four-point bending tests were performed on glass substrate samples from Examples 2 (ion exchange performed according to the methods described above in the examples herein) and 9 (ion exchange performed according to condition 4). The results are shown in... Figure 35 The Weibull distribution plot. (See example.) Figure 35 As shown, Example 9 exhibits a higher stress or failure load (e.g., greater than about 400 MPa).

[0173] Glass-based articles made from compositions having a strain point greater than 525°C, as described above, allow for ion exchange temperatures (or ion exchange bath temperatures) in the range of about 350°C to about 480°C. In some embodiments, glass compositions exhibiting a diffusion rate greater than about 800 square micrometers per hour enable metal oxides to diffuse into the glass-based article to rapidly penetrate the entire depth or thickness of the article, thereby minimizing stress relaxation. Excessive stress relaxation can reduce the surface compressive stress of the glass-based article.

[0174] It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from its spirit and scope.

[0175] The embodiments of the present invention also include: Project 1. A glass-based article comprising: Define a first surface with thickness (t) and a second surface opposite to the first surface; and The concentration of the metal oxide, which is not zero and varies along a thickness range of approximately 0.t to approximately 0.3.t. When the glass-based article breaks, it breaks into at least 2 fragments per inch. 2 .

[0176] Project 2. The glass-based article as described in Project 1, characterized in that the concentration of the metal oxide is not zero and varies along the entire thickness.

[0177] Item 3. The glass-based article as described in any of the preceding items, characterized in that the metal oxide generates stress along the thickness range.

[0178] Item 4. The glass-based article as described in any of the preceding items, characterized in that the concentration of the metal oxide decreases from the first surface to a position between the first surface and the second surface, and increases from the position to the second surface.

[0179] Item 5. The glass-based article as described in any of the preceding items, characterized in that it also has a surface compressive stress (CS) of about 300 MPa or greater.

[0180] Item 6. The glass-based article as described in Item 5, characterized in that the surface CS is about 600 MPa or greater.

[0181] Item 7. The glass-based article as described in any of the preceding items, characterized in that the concentration of the metal oxide throughout the thickness is about 0.05 mol% or greater.

[0182] Item 8. The glass-based article as described in any of the preceding items, characterized in that the concentration of the metal oxide at the first surface is about 1.5 times that at a depth equal to about 0.5•t.

[0183] Item 9. The glass-based article as described in any of the preceding items, characterized in that the glass-based article has a total concentration of the metal oxide in the range of about 1 mol% to about 15 mol%.

[0184] Item 10. The glass-based article as described in any of the preceding items, characterized in that the metal oxide comprises any one or more of Li2O, Na2O, K2O, Rb2O and Cs2O.

[0185] Item 11. The glass-based article as described in any of the preceding items, characterized in that it further has a surface CS of about 300 MPa or greater and a chemical layer depth of about 0.4 t or greater.

[0186] Item 12. A glass-based article as described in any of the preceding items, characterized in that it further has a CS extending from the first surface to the DOC, and the DOC is about 0.1 t or greater.

[0187] Item 13. The glass-based article as described in any of the preceding items, characterized in that it further comprises a central tension (CT) region, and said CT region comprises the metal oxide concentration gradient.

[0188] Item 14. The glass-based article as described in Item 13, characterized in that the CT region has a maximum CT, and the ratio of the maximum CT to the surface CS is in the range of about 0.01 to about 0.5.

[0189] Item 15. A glass-based article as described in any of the preceding items, characterized in that t is about 3 mm or less.

[0190] Item 16. A glass-based article as described in any of the preceding items, characterized in that t is about 1 mm or less.

[0191] Item 17. The glass-based article as described in any of the preceding items, characterized in that it further comprises an amorphous structure.

[0192] Item 18. The glass-based article as described in any of the preceding items, characterized in that it further comprises a crystal structure.

[0193] Item 19. The glass-based article as described in any of the preceding items, characterized in that it also exhibits a transmittance of about 88% or greater in the wavelength range of about 380 nm to about 780 nm.

[0194] Item 20. The glass-based article as described in any of the preceding items, characterized in that it also exhibits a transmittance of about 10% or less in the wavelength range of about 380 nm to about 780 nm.

[0195] Item 21. The glass-based article as described in any of the preceding items, characterized in that it also exhibits L under the CIE light source F02. The value is approximately 88 or greater, a The value is in the range of approximately -3 to approximately +3, and b CIELAB color space coordinates with values ​​ranging from approximately -6 to approximately +6.

[0196] Item 22. The glass-based article as described in any of the preceding items, characterized in that it also exhibits L under the CIE light source F02. The value is approximately 40 or less, a The value is in the range of approximately -3 to approximately +3, and b CIELAB color space coordinates with values ​​ranging from approximately -6 to approximately +6.

[0197] Item 23. The glass-based article as described in any of the preceding items, characterized in that it further comprises: Define a first surface with thickness (t) and a second surface opposite to the first surface, and define a first metal oxide concentration and a second metal oxide concentration. Wherein, the concentration of the first metal oxide, starting from a first thickness range of about 0.t to about 0.5.t, is in the range of about 0 mol% to about 15 mol%. The concentration of the second metal oxide, ranging from about 0 micrometers to about 25 micrometers in a second thickness range, is in the range of about 0 mol% to about 10 mol%.

[0198] Item 24. The glass-based article as described in Item 23, characterized in that it further comprises a third metal oxide.

[0199] Item 25. A glass-based article comprising: Define a first surface with a thickness (t) and a second surface opposite to the first surface, wherein the thickness (t) is less than approximately 3 millimeters; and The stress curve extending along the thickness, Among them, all points on the stress curve with a thickness range of approximately 0.t to 0.3.t and greater than 0.7.t have tangents less than approximately -0.1 MPa / micrometer or greater than approximately 0.1 MPa / micrometer. Furthermore, the stress curve has a maximum CS, a maximum DOC, and a maximum CT, wherein the ratio of the maximum CT to the maximum CS is in the range of approximately 0.01 to approximately 0.5, and the DOC is approximately 0.1•t or greater. When the glass-based article breaks, it breaks into at least 2 fragments per inch. 2 .

[0200] Item 26. The glass-based article as described in Item 25, characterized in that it further has a surface pressure (CS) of about 300 MPa or greater.

[0201] Item 27. The glass-based article as described in Item 26, characterized in that the surface CS is about 600 MPa or greater.

[0202] Item 28. A glass-based article as described in any one of items 25 to 27, characterized in that it further has a surface CS of about 300 MPa or greater and a chemical layer depth (DOL) of about 0.4 t or greater.

[0203] Item 29. A glass-based article as described in any one of items 25 to 28, characterized in that it further comprises a CS layer extending from the first surface to the DOC, wherein the DOC is about 0.1 t or greater.

[0204] Item 30. The glass-based article as described in any one of items 25 to 29, characterized in that it further comprises a CT region, and the CT region comprises a metal oxide concentration gradient.

[0205] Item 31. The glass-based article as described in Item 26, characterized in that the CT region has a maximum CT, and the ratio of the maximum CT to the surface CS is in the range of about 0.01 to about 0.5.

[0206] Item 32. The glass-based article as described in any one of items 25 to 31, characterized in that t is about 2 mm or less.

[0207] Item 33. The glass-based article as described in any one of items 25 to 32, characterized in that t is about 1 mm or less.

[0208] Item 34. A glass-based article comprising: Define a first surface with thickness (t) and a second surface opposite to the first surface; and The concentration of the metal oxide, which is not zero and varies along a thickness range of about 0.t to about 0.3.t; and Surface pressure (CS) greater than approximately 200 MPa or larger.

[0209] Item 35. The glass-based article as described in Item 34, characterized in that the thickness is in the range of about 0.t to about 0.4.t.

[0210] Item 36. A glass-based article as described in Item 34 or 35, characterized in that the thickness is in the range of about 0.t to about 0.45.t.

[0211] Item 37. A glass-based article as described in any one of items 34 to 36, characterized in that the metal oxide generates stress along the thickness range.

[0212] Item 38. The glass-based article as described in Item 37, characterized in that the metal oxide has the largest ion diameter among all the total metal oxides in the glass-based substrate.

[0213] Item 39. A glass-based article as described in any one of items 34 to 38, characterized in that the concentration of the metal oxide decreases from the first surface to a position between the first surface and the second surface, and increases from the position to the second surface.

[0214] Item 40. A glass-based article as described in any one of items 34 to 39, characterized in that, when the glass-based article breaks, it breaks into at least one fragment per inch. 2 Up to 40 pieces / inch 2 .

[0215] Item 41. A glass-based article as described in any one of Items 34 to 40, characterized in that the glass-based article has a diameter of about 450 micrometers at about 460°C. 2 The surface CS is 1.5 times or greater than the maximum CT, with a diffusion rate of / hour or greater and a maximum CT of about 0.15 t.

[0216] Item 42. A glass-based article as described in any one of items 34 to 41, characterized in that the glass-based article has a strength of about 0.7 MPa•m. 1 / 2 or greater fracture toughness (K 1C ).

[0217] Item 43. The glass-based article as described in Item 41, characterized in that the surface CS is greater than the maximum CT.

[0218] Item 44. The glass-based article as described in any one of items 34 to 43, characterized in that the surface CS is about 300 MPa or greater.

[0219] Item 45. The glass-based article as described in any one of items 34 to 44, characterized in that the surface CS is about 600 MPa or greater.

[0220] Item 46. The glass-based article as described in any one of items 34 to 45, characterized in that the concentration of the metal oxide throughout the thickness is about 0.05 mol% or greater.

[0221] Item 47. The glass-based article as described in any one of items 34 to 46, characterized in that the concentration of the metal oxide at the first surface is about 1.5 times that at a depth equal to about 0.5•t.

[0222] Item 48. The glass-based article as described in any one of items 34 to 47, characterized in that the total concentration of the metal oxide is in the range of about 1 mol% to about 15 mol%.

[0223] Item 49. The glass-based article as described in any one of Items 34 to 48, characterized in that the metal oxide comprises any one or more of Li2O, Na2O, K2O, Rb2O and Cs2O.

[0224] Item 50. The glass-based article as described in any one of items 34 to 49, characterized in that it further has a chemical layer depth of about 0.4 t or more.

[0225] Item 51. A glass-based article as described in any one of items 34 to 50, characterized in that it further comprises a CS layer extending from the first surface to the DOC, wherein the DOC is about 0.1 t or greater.

[0226] Item 52. The glass-based article as described in any one of items 34 to 51, characterized in that it further comprises a CT region, and said CT region comprises a metal oxide concentration gradient.

[0227] Item 53. The glass-based article as described in Item 52, characterized in that the CT region has a maximum CT, and the ratio of the maximum CT to the surface CS is in the range of about 0.01 to about 0.5.

[0228] Item 54. The glass-based article as described in any one of items 34 to 53, characterized in that t is about 3 mm or less.

[0229] Item 55. A glass-based article as described in any one of items 34 to 54, characterized in that t is about 1 mm or less.

[0230] Item 56. A glass-based article comprising: Define a first surface with thickness (t) and a second surface opposite to the first surface; and Metal oxides that form a concentration gradient The concentration of the metal oxide decreases from the first surface to a position between the first surface and the second surface, and then increases from that position to the second surface. And the concentration of the metal oxide at the stated location is not zero, and The glass-based product has a strength greater than approximately 0 J / m 2 And less than 20 J / m 2 Stretching energy storage.

[0231] Item 57. The glass-based article as described in Item 56, characterized in that it further has a surface pressure (CS) of about 300 MPa or greater.

[0232] Item 58. The glass-based article as described in Item 57, characterized in that the surface CS is about 600 MPa or greater.

[0233] Item 59. The glass-based article as described in any one of items 56 to 58, characterized in that the concentration of the metal oxide throughout the thickness is about 0.05 mol% or greater.

[0234] Item 60. The glass-based article as described in any one of items 56 to 59, characterized in that the concentration of the metal oxide at the first surface is about 1.5 times that at a depth equal to about 0.5•t.

[0235] Item 61. The glass-based article as described in any one of Items 56 to 60, characterized in that the total concentration of the metal oxide is in the range of about 1 mol% to about 15 mol%.

[0236] Item 62. The glass-based article as described in any one of Items 56 to 61, characterized in that the metal oxide comprises any one or more of Li2O, Na2O, K2O, Rb2O and Cs2O.

[0237] Item 63. The glass-based article as described in any one of items 56 to 62, characterized in that it further has a surface CS of about 200 MPa or greater and a chemical layer depth of about 0.4 t or greater.

[0238] Item 64. A glass-based article as described in any one of items 56 to 63, characterized in that it further comprises a CS layer extending from the first surface to the DOC, wherein the DOC is about 0.1 t or greater.

[0239] Item 65. The glass-based article as described in any one of items 56 to 64, characterized in that it further comprises a CT region, and said CT region comprises a metal oxide concentration gradient.

[0240] Item 66. The glass-based article as described in any one of items 56 to 65, characterized in that the CT region has a maximum CT, and the ratio of the maximum CT to the surface CS is in the range of about 0.01 to about 0.5.

[0241] Item 67. The glass-based article as described in any one of items 56 to 66, characterized in that t is about 3 mm or less.

[0242] Item 68. The glass-based article as described in any one of items 56 to 67, characterized in that t is about 1 mm or less.

[0243] Item 69. A glass-based article comprising: Define a first surface with a thickness (t) and a second surface opposite to the first surface, wherein the thickness (t) is less than approximately 3 millimeters; and The stress curve extending along the thickness, Among them, all points on the stress curve with a thickness range of approximately 0t to 0.3t and greater than 0.7t have tangents less than approximately -0.1 MPa / micrometer or greater than approximately 0.1 MPa / micrometer. Furthermore, the stress curve has a maximum CS, a maximum DOC, and a maximum CT, wherein the ratio of the maximum CT to the maximum CS is in the range of approximately 0.01 to approximately 0.5, and the DOC is approximately 0.1•t or greater. The glass-based product has a strength greater than approximately 0 J / m 2 And less than 20 J / m 2 Stretching energy storage.

[0244] Item 70. The glass-based article as described in Item 69, characterized in that it further comprises a non-zero concentration of metal oxides that varies continuously along the entire thickness.

[0245] Item 71. A glass-based article as described in Item 69 or 70, characterized in that it further comprises a non-zero concentration of metal oxides that varies continuously along a thickness range of less than about 10 micrometers.

[0246] Item 72. The glass-based article as described in any one of items 67 to 71, characterized in that the maximum CS is about 300 MPa or greater.

[0247] Item 73. The glass-based article as described in any one of items 67 to 72, characterized in that the maximum CS is about 600 MPa or greater.

[0248] Item 74. The glass-based article as described in any one of items 67 to 73, characterized in that it further has a chemical layer depth of about 0.4 t or greater.

[0249] Item 75. The glass-based article as described in any one of items 67 to 74, characterized in that it further comprises a CT region, and said CT region comprises a metal oxide concentration gradient.

[0250] Item 76. The glass-based article as described in any one of items 67 to 75, characterized in that t is about 3 mm or less.

[0251] Item 77. The glass-based article as described in any one of items 67 to 76, characterized in that t is about 1 mm or less.

[0252] Item 78. A glass-based article comprising: The stress curve includes the CS region and the CT region, wherein the CT region is defined by the following formula: Stress(x) = MaxCT - (((MaxCT•(n+1)) / 0.5) n •|(x / t)-0.5| n ), Where MaxCT is the maximum CT value, which is a positive value in MPa, x is the position along the thickness (t) in micrometers, and n is between 1.5 and 5.

[0253] Item 79. The glass-based article as described in Item 78, characterized in that the CT region has a maximum CT value in the range of about 50 MPa to about 250 MPa, and the maximum CT value is located at a depth in the range of about 0.4t to about 0.6t.

[0254] Item 80. A glass-based article as described in Item 78 or 79, characterized in that the stress curve has a slope in the range of about 20 MPa / micrometer to about 200 MPa / micrometer, starting from a thickness in the range of about 0 t to about 0.1 t micrometers.

[0255] Item 81. The glass-based article as described in any one of Items 78 to 80, characterized in that the stress curve is defined by a plurality of error functions measured from 0.5t to within the surface.

[0256] Item 82. A method for forming a fracture-resistant glass-based article, the method comprising: A glass-based substrate having a first surface and a second surface, wherein the first and second surfaces define a thickness of about 3 mm or less; Stress profiles are generated in a glass substrate comprising a CT layer and a CS layer, wherein the CS layer has a surface CS, a chemical depth of about 0.4t or greater, and a DOC of about 0.1t or greater, and the CT layer has a maximum CT, and the ratio of the maximum CT to the surface CS is about 0.01 to about 0.5.

[0257] Item 83. The method of Item 82, wherein generating the stress curve comprises exchanging a plurality of metal ions into the glass substrate to form a metal oxide concentration gradient having a non-zero metal oxide concentration extending along the thickness.

[0258] Item 84. The method of Item 83, characterized in that the concentration of the metal oxide decreases from the first surface to a position between the first surface and the second surface, and increases from said position to the second surface. Item 85. The method of any one of items 82 to 84, characterized in that the CT layer contains a metal oxide concentration gradient.

[0259] Item 86. The method of any one of items 82 to 85, characterized in that it further includes increasing the surface CS by approximately 100 MPa or more after generating the stress curve.

[0260] Item 87. The method of Item 86, characterized in that generating the stress curve includes first ion-exchanging a first group of multiple ions into the glass substrate to form the metal oxide concentration gradient including a non-zero metal oxide concentration extending along the thickness, and increasing the surface CS includes ion-exchanging a second group of multiple alkali metal ions into the glass substrate having the alkali metal oxide concentration gradient.

[0261] Item 88. The method of Item 86, characterized in that generating the stress curve includes first ion-exchanging a plurality of ions into the glass substrate to form a metal oxide concentration gradient comprising a non-zero metal oxide concentration extending along the thickness, wherein the plurality of ions comprises two different ions with different ionic radii.

[0262] Item 89. Use of a glass composition in tempered glass, said glass composition comprising: SiO2, the amount of which is in the range of about 68 to about 75; Al2O3, the amount of which is in the range of about 12 to about 15; B2O3, in amounts ranging from approximately 0.5 to approximately 5; The amount of Li2O is in the range of about 2 to about 8. Na2O, the amount of which is in the range of about 0 to about 6; MgO, in amounts ranging from about 1 to about 4; ZnO, in amounts ranging from approximately 0 to approximately 3; and The amount of CaO is in the range of approximately 0 to approximately 5. The glass substrate is capable of ion exchange and is amorphous. Furthermore, the glass substrate exhibits one or more of the following: The ratio of Li₂O to R₂O is in the range of approximately 0.5 to approximately 1. The difference between the total amount of R2O and the amount of Al2O3 is in the range of approximately -5 to approximately 0. R x The difference between the total amount of O (in mole percent) and the amount of Al2O3 is in the range of approximately 0 to approximately 3; and The ratio of the amount of MgO (in mole%) to the total amount of RO (in mole%) is in the range of approximately 0 to approximately 2, and The glass substrate is substantially free of nucleating agents.

[0263] Item 90. A glass substrate comprising the following components, in mole percent: SiO2, the amount of which is in the range of about 68 to about 75; Al2O3, the amount of which is in the range of about 12 to about 15; B2O3, in amounts ranging from approximately 0.5 to approximately 5; The amount of Li2O is in the range of about 2 to about 8. Na2O, the amount of which is in the range of about 0 to about 6; MgO, in amounts ranging from about 1 to about 4; ZnO, in amounts ranging from approximately 0 to approximately 3; and The amount of CaO is in the range of approximately 0 to approximately 5. The glass substrate is capable of ion exchange and is amorphous. Furthermore, the glass substrate exhibits one or more of the following: The ratio of Li₂O to R₂O is in the range of approximately 0.5 to approximately 1. The difference between the total amount of R2O and the amount of Al2O3 is in the range of approximately -5 to approximately 0. R x The difference between the total amount of O (in mole percent) and the amount of Al2O3 is in the range of approximately 0 to approximately 3; and The ratio of the amount of MgO (in mole%) to the total amount of RO (in mole%) is in the range of approximately 0 to approximately 2, and The glass substrate is substantially free of nucleating agents.

[0264] Item 91. A glass substrate comprising the following components, in mole percent: SiO2, the amount of which is in the range of about 68 to about 75; Al2O3, the amount of which is in the range of about 12 to about 15; B2O3, in amounts ranging from approximately 0.5 to approximately 5; The amount of Li2O is in the range of about 2 to about 8. Na2O, the amount of which is in the range of about 0 to about 6; MgO, in amounts ranging from about 1 to about 4; ZnO, in amounts ranging from approximately 0 to approximately 3; and The amount of CaO is in the range of approximately 0 to approximately 5. The glass substrate is amorphous, and the glass is strengthened. Furthermore, the concentration of Na2O changes, and it basically does not contain nucleating agents.

[0265] Item 92. The reinforced glass substrate as described in Item 91, characterized in that it further exhibits any one or more of the following: The ratio of Li₂O to R₂O is in the range of approximately 0.5 to approximately 1. The difference between the total amount of R2O and the amount of Al2O3 is in the range of approximately -5 to approximately 0. R x The difference between the total amount of O (in mole percent) and the amount of Al2O3 is in the range of approximately 0 to approximately 3; and The ratio of the amount of MgO (in mole%) to the total amount of RO (in mole%) is in the range of about 0 to about 2.

Claims

1. A glass-based article comprising the following components, in mol%: SiO2, the amount of which is in the range of about 45 to about 75; Al2O3, the amount of which is in the range of about 10 to about 30; B2O3, the amount of which is in the range of about 0 to about 10; Na2O, the amount of which is in the range of about 0 to about 5; MgO, in amounts ranging from about 0 to about 5; ZnO, in amounts ranging from about 0 to about 2; and wherein The glass substrate is amorphous. The glass substrate exhibits the following characteristics: The ratio of Li2O to R2O is in the range of about 0.5 to about 1, where R2O is the total amount of alkali metal oxides; The difference between the total amount of R2O and the amount of Al2O3 is in the range of approximately -5 to approximately 0. The glass substrate undergoes ion exchange to exhibit a stress curve, wherein: The stress curve includes maximum CS, DOC, and maximum CT, wherein the ratio of maximum CT to maximum CS is in the range of approximately 0.01 to approximately 0.

5. The DOC is approximately 0.1 t or greater, where t is the thickness of the glass substrate, and The glass-based article comprises a tensile energy to break of about greater than 0 J / m 2 to less than 20 J / m 2 .

2. The glass-based article according to claim 1, wherein, The composition further comprises P2O5 in an amount ranging from 0 mol% to 10 mol%.

3. The glass-based article according to claim 2, wherein, The composition contains P2O5 in an amount ranging from 0.1 mol% to 8 mol%.

4. The glass-based article according to claim 2, wherein the composition further comprises Li2O in an amount ranging from 6 mol% to 10 mol%.

5. The glass-based article according to claim 4, wherein the composition comprises R2O in an amount ranging from 8 mol% to 20 mol% and B2O3 in an amount ranging from 4 mol% to 10 mol%.

6. The glass-based article according to any one of claims 1-5, further comprising a non-zero concentration of metal oxides that varies continuously along the entire thickness.

7. The glass-based article according to any one of claims 1-5, wherein the maximum CS comprises about 300 MPa or higher.

8. The glass-based article according to any one of claims 1-5, wherein the maximum CS comprises about 600 MPa or higher.

9. The glass-based article according to any one of claims 1-5, further comprising a chemical layer depth of about 0.4 t or greater.

10. The glass-based article of any one of claims 1-5, further comprising a CT region, wherein the CT region comprises a metal oxide concentration gradient.

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