Glass articles resistant to breakage and scratching

Abstract

This application relates to crack-resistant and scratch-resistant glass articles. Embodiments of glass compositions, glass articles, and chemically strengthened glass articles are disclosed. In one or more embodiments, the glass composition comprises: Li2O, greater than about 0.9 mole % B2O3, an amount of Al2O3 greater than or equal to 10 mole %, and about 60 - 80 mole % SiO2. Embodiments of the chemically strengthened glass article include: a first major surface and an opposite second major surface that define a thickness t, a compressive stress layer extending from the first major surface to a compressive depth greater than about 0.12t, a maximum compressive stress greater than or equal to about 200 MPa, and a Knoop lateral cracking scratch threshold greater than about 6 N, which is measured on either the first major surface or the second major surface. Also disclosed is a method for forming such chemically strengthened glass articles.

Description

[0001] This divisional application of a patent application for invention has an international application number of PCT / US2017 / 034442, an international filing date of May 25, 2017, and an application number for entering the Chinese national phase of 201780010712.3, and an invention title of "Breakage-Resistant and Scratch-Resistant Glass Articles".

[0002] Cross - reference to related applications

[0003] This application claims priority under 35 U.S.C.§119 to U.S. Provisional Application Serial No. 62 / 358379, filed on July 5, 2016, and U.S. Provisional Application Serial No. 62 / 342558, filed on May 27, 2016, which are hereby incorporated by reference in their entireties and made a part hereof. Background of the Invention

[0004] The present disclosure relates to breakage - resistant and scratch - resistant glass articles, and more particularly, to glass articles comprising a composition containing Li 2 O and B 2 O 3 which, after strengthening, exhibit a deep depth of compression and high scratch resistance.

[0005] Glass articles are often subjected to severe impacts, which can introduce large flaws into the surface of such articles. Such flaws can extend from the surface to a depth of up to about 200 micrometers (μm). Generally, heat - tempered glass articles have been used to prevent failure due to such flaws being introduced into the glass, because heat - tempered glass articles typically exhibit a deep compressive stress (CS) layer (e.g., about 21% of the total thickness of the glass article), which can prevent the flaws from further propagating into the glass article, thereby preventing failure. An example of the stress distribution produced by heat - tempering is as Figure 1 shown. Figure 1 is a cross - sectional view of the stress distribution of heat - tempered glass article 100 along its thickness (shown along the x - axis). The magnitude of the stress is shown on the y - axis, and line 101 represents the intersection between zero stress and the transition from compressive stress to tensile stress.

[0006] In Figure 1 the heat - treated glass article 100 includes a first surface 102, a thickness t 1 , and a surface CS 110. The heat - treated glass article 100 exhibits a CS that decreases from the first surface 101 to the depth of compression (DOC) 130, which is the depth within the glass article at which the stress changes from compressive to tensile. At depths beyond the DOC, the stress is tensile and reaches a maximum central tension (CT) 120.

[0007] Hot tempering is currently limited to thick glass articles (i.e., glass articles having a thickness t 1 greater than or equal to about 3 millimeters), because to achieve thermal strengthening and the desired residual stress, a sufficient thermal gradient must be formed between the core and the surface of such articles. In many applications, such as displays (e.g., consumer electronics, including mobile phones, tablets, computers, navigation systems, etc.), construction (e.g., windows, shower panels, work surfaces, etc.), transportation vehicles (e.g., vehicles, trains, spacecraft, seagoing vessels, etc.), appliances, or any application that requires excellent crack resistance but thin and lightweight articles, such thick articles are undesirable or impractical.

[0008] Although chemical strengthening is not limited by the thickness of the glass article as is the case with hot tempering, known chemically strengthened glass articles cannot exhibit the stress distribution of hot tempered glass articles. An example of the stress distribution produced by chemical strengthening (e.g., an ion exchange process) is as Figure 2 shown. Figure 2 is a cross-sectional view of the stress distribution along the thickness (shown along the x-axis) of a known chemically strengthened glass article 200. The magnitude of the stress is shown on the y-axis, and the line 201 represents the intersection of zero stress and the transition from compressive stress to tensile stress. In Figure 2 the chemically strengthened glass article 200 includes a first surface 201, a thickness t 2 , and a surface CS210. The CS exhibited by the glass article 200 decreases from the first surface 201 to the DOC 230, which is the depth at which the stress changes from compressive to tensile. Beyond the DOC, the stress is tensile and reaches a maximum CT 220. As Figure 2 shown, such a distribution exhibits a substantially flat CT region or a CT region having a constant or nearly constant tensile stress along at least a portion of the CT region. Generally, compared to the maximum central value shown in Figure 1 , known chemically strengthened glass articles exhibit a lower maximum CT value.

[0009] Accordingly, there is a need for thin glass articles that exhibit improved crack resistance. SUMMARY OF THE INVENTION

[0010] A first aspect of the present disclosure pertains to aluminosilicate glass articles having the following composition: comprising Li 2 O, P 2 O 5 , and greater than about 0.9 mole % B 2 O 3 . In one or more embodiments, the composition comprises: an amount of SiO 2 of about 60 - 80 mole %, Al 2 O 3The amount of is greater than or equal to about 10 mol% or 13.5 mol%, Li 2 The amount of O is about 5 - 11 mol%, P 2 O 5 The amount of is about 1 - 5 mol%, greater than about 0.9 mol% B 2 O 3 , and Na 2 The amount of O is about 0.5 - 12 mol%.

[0011] In one or more embodiments, the composition comprises: SiO 2 The amount of is about 60 - 80 mol%, Al 2 O 3 The amount of is greater than or equal to 10 mol%, Li 2 The amount of O is up to and including about 10 mol%, P 2 O 5 The amount of is about 1 - 5 mol%, greater than about 0.9 mol% B 2 O 3 , and Na 2 The amount of O is about 0.5 - 12 mol%.

[0012] In one or more embodiments, the amount of Al 2 O 3 present in the composition is about 13.5 - 18 mol%. In one or more embodiments, the amount of P 2 O 5 present in the composition can be less than about 3 mol%. In one or more embodiments, the amount of B 2 O 3 is about 0.9 - 6.5 mol% or about 1 - 6.5 mol%. In one or more embodiments, B 2 O 3 , P 2 O 5 , SiO 2 and Al 2 O 3 in total is greater than or equal to about 80 mol%.

[0013] In one or more embodiments, the composition comprises R 2 O. As used herein, R 2 O refers to alkali metal oxides such as Li 2 O, Na 2 O, K 2 O, Rb 2 O and Cs 2 O. In one or more embodiments, the total amount of R 2 O included in the composition (referring to the total amount of any and all alkali metal oxides in the composition) is about 12 - 20 mol%.

[0014] In one or more embodiments, Na 2 The amount of O is about 3-11 mol%. In some embodiments, the composition includes Li 2 The amount of O is about 5-11 mol % or about 5-7 mol %. Optionally, the composition may be substantially free of K. 2 O. In one or more embodiments, Na 2 The amount of O is greater than that of Li 2 The amount of O.

[0015] In one or more embodiments, the composition comprises RO. As used herein, RO refers to alkaline earth metal oxides, such as MgO, CaO, SrO, BaO, ZnO, etc. In some embodiments, the total amount of RO (referring to the total amount of any and all alkaline earth metal oxides in the composition) is about 0.05-4 mol%. In one or more specific embodiments, the amount of ZnO included in the composition is about 0.5-3 mol%.

[0016] The composition of one or more embodiments may include SnO 2 In one or more embodiments, the composition comprises less than about 15 mol % ZrO 2 .

[0017] In one or more embodiments, the composition exhibits a liquidus viscosity of less than or equal to about 300 kilopoise. In some other embodiments, the composition exhibits a liquidus viscosity greater than about 300 kilopoise.

[0018] A second aspect of the present disclosure pertains to chemically strengthened glass articles. In one or more embodiments, the chemically strengthened glass article comprises a first major surface and an opposing second major surface defining a thickness t, and further comprises a composition comprising: Li 2 O, P 2 O 5 , greater than about 0.9 mol % B 2 O 3 , Al 2 O 3 The amount is greater than or equal to 13.5 mol%, and about 0.5-12 mol% Na 2 In one or more embodiments, the composition of the chemically strengthened glass article may include: Li 2 The amount of O is less than or equal to about 10 mol%, P 2 O 5 , greater than about 0.9 mol % B 2 O 3 , Al 2 O 3 An amount greater than or equal to 10 mol %, and about 0.5-12 mol % Na2 O.

[0019] In one or more embodiments, a chemically strengthened glass article includes a CS layer extending from a first major surface to a DOC, where the DOC is greater than or equal to about 0.1t or greater than or equal to about 0.12t. In some embodiments, the chemically strengthened glass article includes a CS layer having a maximum CS greater than or equal to about 200 MPa. In some embodiments, the CS layer includes a surface CS greater than or equal to 300. In one or more embodiments, the chemically strengthened glass article includes a maximum CT greater than about 40 MPa or a maximum CT of about 40 - 100 MPa. In some cases, the maximum CT is less than about 100 MPa. In one or more embodiments, the chemically strengthened glass article exhibits an absolute value ratio of the maximum CT to the maximum CS of about 0.01 to about 0.2.

[0020] In one or more embodiments, the chemically strengthened glass article includes a stress profile extending throughout the thickness t, wherein all points of the stress profile in the thickness ranges from about 0t up to 0.3t and greater than 0.7t include a tangent having an absolute value of the slope greater than about 0.1 MPa / micron. In other embodiments, the chemically strengthened glass article includes a stress profile extending throughout the thickness t, wherein each of at least one point in the thickness range from about 0t up to 0.3t and at least one point in the stress profile in the thickness range greater than 0.7t includes a tangent having an absolute value of the slope greater than about 0.1 MPa / micron.

[0021] In one or more embodiments, the chemically strengthened glass article includes a metal oxide concentration that is non - zero and varies along the thickness range from about 0t to about 0.3t. In some embodiments, the metal oxide includes Na 2 O, K 2 O, Rb 2 O, and Cs 2 O, or any one or more thereof. In some embodiments, the concentration of the metal oxide is non - zero and varies throughout the thickness. In one or more embodiments, the metal oxide generates stress along the thickness range where its concentration is non - zero and varies. Optionally, the concentration of the metal oxide decreases from the first surface to a value at a point between the first and second surfaces and increases from that value to the second surface. In one or more embodiments, the chemically strengthened glass article exhibits a maximum chemical depth greater than or equal to about 0.4t.

[0022] In one or more embodiments, the chemically strengthened glass article includes a Young's modulus less than 85 MPa.

[0023] In one or more embodiments, the non-strengthened glass article and the chemically strengthened glass article include a Knoop lateral crack scratch threshold greater than about 6 N, which is measured on either the first major surface or the second major surface.

[0024] A third aspect of the present disclosure pertains to an apparatus, which includes: a housing having a front surface, a rear surface, and side surfaces; an electronic component at least partially disposed inside the housing; a display located on or adjacent to the front surface of the housing; and a cover article disposed on the display, wherein the cover article includes a chemically strengthened glass article according to the embodiments described herein.

[0025] Other features and advantages of the present disclosure 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 may be recognized by practicing the various embodiments described herein, which include the following detailed description, the claims, and the drawings.

[0026] It should be understood that both the foregoing general description and the following detailed description are merely exemplary and are intended to provide an overall review or framework for understanding the nature and characteristics of the claims. The accompanying drawings provide further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate one or more embodiments and, together with the specification, are used to explain the principles and operations of the various embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a cross-sectional view through the thickness of a known thermally tempered glass article;

[0028] Figure 2 is a cross-sectional view through the thickness of a known chemically strengthened glass article;

[0029] Figure 3 is a side view of a glass article according to one or more embodiments;

[0030] Figure 4 is a cross-sectional view through the thickness of a chemically strengthened glass article according to one or more embodiments of the present disclosure;

[0031] Figure 5 is a schematic cross-sectional view of a ring-on-ring apparatus;

[0032] Figure 6 is a schematic cross-sectional view of one embodiment of an apparatus for performing the in-ball-on-sandpaper (IBoS) test described herein;

[0033] Figure 7is a cross-sectional schematic view that depicts the main mechanisms of failure resulting from damage introduction plus bending, which are common in glass-based articles for mobile or handheld electronic devices;

[0034] Figure 8 is a flowchart of the method for performing IBoS testing in the devices described herein; and

[0035] Figure 9 is a front-plane schematic view of an electronic device incorporating one or more embodiments of the glass articles described herein;

[0036] Figure 10 is a side view of a test device for glass-based articles;

[0037] Figure 11 is Figure 10 a side view of a portion of the test device shown;

[0038] Figure 12 is Figure 10 a rear-end perspective view of the test device shown;

[0039] Figure 13 is Figure 10 a front-end perspective view of the test device shown;

[0040] Figure 14 is a side-schematic view of a test device for glass-based articles;

[0041] Figure 15 is Figure 10 a side view of a portion of the test device shown;

[0042] Figure 16 is a perspective view of another test device for glass-based articles;

[0043] Figure 17 is Figure 16 a side view of a portion of the test device of;

[0044] Figure 18 is with Figure 10 a graph of the results of a surface impact test of a glass sample tested with the device of;

[0045] Figure 19 is with Figure 16 a graph of the results of an edge impact test of a glass sample tested with the device of. Detailed Description of the Embodiments

[0046] Each embodiment is described in detail below.

[0047] In the following description, like reference numerals represent like or corresponding parts in several views shown in the drawings. It should also be understood that, unless otherwise indicated, terms such as "top", "bottom", "outward", "inward" are convenience words and do not constitute a limitation on the terms. In addition, whenever a group is described as including at least one of a group of elements and combinations thereof, it should be understood that the group can include any number of these listed elements in the form of a single element or in combination with each other, or consist essentially of them, or consist of them. Similarly, whenever a group is described as consisting of at least one of a group of elements or combinations thereof, it should be understood that the group can consist of any number of these listed elements in the form of a single element or in combination with each other. Unless otherwise specified, the recited numerical ranges include both the upper and lower limits of the range, as well as any range therebetween. Unless otherwise indicated, the indefinite article "a" or "an" and their corresponding definite article "the" as 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.

[0048] As used herein, the term "glass article" is used in its broadest sense and includes any object made wholly or in part of glass. Glass articles include laminates of glass and non-glass materials, laminates of glass and crystalline materials, and glass-ceramics (including amorphous and crystalline phases).

[0049] It should be noted that the terms "substantially" and "about" as used herein can represent the degree of inherent uncertainty caused by any quantitative comparison, numerical value, measurement or other representation method. These terms are also used herein to indicate that the indicated value of a quantity can deviate to a certain degree from the reference value, but will not cause a change in the basic function of the subject under consideration. Thus, for example, a glass article "substantially free of MgO" is a glass article in which MgO has not been actively added or formulated into the glass article, but may be present in very small amounts as a contaminant.

[0050] Unless otherwise indicated, all temperatures are expressed in degrees Celsius (°C). The unit of the coefficient of thermal expansion (CTE) is parts per million (ppm) / degree Celsius (°C) and represents a value measured over a temperature range of about 20 - 300 °C, unless otherwise indicated. The high temperature (or liquid) CTE is also expressed as ppm / °C and represents a value measured in the high temperature plateau region of the instantaneous CTE versus temperature curve. The high temperature CTE measures the volume change associated with heating or cooling the glass through the transition region.

[0051] As used herein, the term "softening point" refers to the temperature at which the viscosity of the glass is about 10 7.6The temperature of the annealing point, in poise (P), refers to the temperature at which the viscosity of the glass is approximately 10 13.2 poise, and the term "200 poise temperature (T 200P )" refers to the temperature at which the viscosity of the glass is approximately 200 poise, and the term "10 11 poise temperature" refers to the temperature at which the viscosity of the glass is approximately 10 11 poise, and the term "35 kP temperature (T 35kP )" refers to the temperature at which the viscosity of the glass is approximately 35 kilopoise (kP), and the term "160 kP temperature (T 160kP )" refers to the temperature at which the viscosity of the glass is approximately 160 kP.

[0052] A first aspect of the present disclosure pertains to aluminosilicate glass articles, which include the following composition: containing Li 2 O, P 2 O 5 , and B 2 O 3 . Unless otherwise specified, all compositions are described as mole percentages (mol%) based on oxide analysis and pertain to the glass article before chemical strengthening as described herein.

[0053] In one or more embodiments, the composition includes: the amount of SiO 2 is approximately 60 - 80 mol%, the amount of Al 2 O 3 is greater than or equal to 13.5 mol%, greater than approximately 0.9 mol% of B 2 O 3 , the amount of Li 2 O is approximately 5 - 11 mol%, the amount of P 2 O 5 is approximately 1 - 5 mol%, and the amount of Na 2 O is approximately 0.5 - 12 mol%.

[0054] In one or more embodiments, the composition includes: the amount of SiO 2 is approximately 60 - 80 mol%, the amount of Al 2 O 3 is greater than or equal to 10 mol%, greater than approximately 0.9 mol% of B 2 O 3 , the amount of Li 2 O is approximately 5 - 10 mol%, the amount of P 2 O 5 is approximately 1 - 5 mol%, and the amount of Na 2 O is approximately 0.5 - 12 mol%.

[0055] In one or more embodiments, the composition includes the following amount of SiO 2: from about 60 mole % to about 80 mole %, from about 60 mole % to about 78 mole %, from about 60 mole % to about 76 mole %, from about 60 mole % to about 75 mole %, from about 60 mole % to about 74 mole %, from about 60 mole % to about 72 mole %, from about 60 mole % to about 70 mole %, from about 60 mole % to about 68 mole %, from about 60 mole % to about 66 mole %, from about 60 mole % to about 64 mole %, from about 62 mole % to about 80 mole %, from about 64 mole % to about 80 mole %, from about 65 mole % to about 80 mole %, from about 66 mole % to about 80 mole %, from about 68 mole % to about 80 mole %, from about 70 mole % to about 80 mole %, from about 72 mole % to about 80 mole %, from about 74 mole % to about 80 mole %, from about 75 mole % to about 80 mole %, from about 62 mole % to about 68 mole %, or from about 63 mole % to about 64.5 mole %, and all ranges and sub - ranges therebetween.

[0056] In one or more embodiments, the composition comprises an amount of Al 2 O 3 greater than about 10 mole %, greater than about 12 mole %, greater than about 13 mole %, greater than about 13.5 mole %, or greater than about 14 mole %. In some cases, the Al 2 O 3 present in the compositions described herein can be in the following ranges: from about 10 mole % to about 20 mole %, from about 10 mole % to about 18 mole %, from about 10 mole % to about 16 mole %, from about 10 mole % to about 15 mole %, from about 10 mole % to about 14 mole %, from about 11 mole % to about 20 mole %, from about 12 mole % to about 20 mole %, from about 12.5 mole % to about 20 mole %, from about 13 mole % to about 20 mole %, from about 13.5 mole % to about 20 mole %, from about 14 mole % to about 20 mole %, or from about 12.5 mole % to about 17 mole %, and all ranges and sub - ranges therebetween.

[0057] In one or more embodiments, the composition contains an amount of B 2 O 3 . In one or more embodiments, the composition contains an amount of B 2 O 3 that is: greater than about 0.1 mole %, greater than about 0.2 mole %, greater than about 0.3 mole %, greater than about 0.4 mole %, greater than about 0.5 mole %, greater than about 0.6 mole %, greater than about 0.7 mole %, greater than about 0.8 mole %, greater than about 0.9 mole %, or greater than about 1 mole %. In one or more embodiments, the composition comprises the following amount of B 2 O 3: from about 0.5 mol% to about 7.5 mol%, from about 0.5 mol% to about 7 mol%, from about 0.5 mol% to about 6.5 mol%, from about 0.5 mol% to about 6 mol%, from about 0.5 mol% to about 5.5 mol%, from about 0.5 mol% to about 5 mol%, from about 0.5 mol% to about 4.5 mol%, from about 0.5 mol% to about 4 mol%, from about 0.5 mol% to about 3.5 mol%, from about 0.9 mol% to about 7.5 mol%, from about 0.9 mol% to about 7 mol%, from about 0.9 mol% to about 6.5 mol%, from about 0.9 mol% to about 6 mol%, from about 0.9 mol% to about 5.5 mol%, from about 0.9 mol% to about 5 mol%, from about 0.9 mol% to about 4.5 mol%, from about 0.9 mol% to about 4 mol%, from about 0.9 mol% to about 3.5 mol%, from about 1 mol% to about 7.5 mol%, from about 1 mol% to about 7 mol%, from about 1 mol% to about 6.5 mol%, from about 1 mol% to about 6 mol%, from about 1 mol% to about 5.5 mol%, from about 1 mol% to about 5 mol%, from about 1 mol% to about 4.5 mol%, from about 1 mol% to about 4 mol%, from about 1 mol% to about 3.5 mol%, from about 1.5 mol% to about 7.5 mol%, from about 2 mol% to about 7.5 mol%, from about 2.5 mol% to about 7.5 mol%, from about 3 mol% to about 7.5 mol%, from about 3.5 mol% to about 7.5 mol%, from about 4 mol% to about 7.5 mol%, from about 4 mol% to about 6 mol%, or from about 1.5 mol% to about 3 mol%, and all ranges and sub - ranges therebetween.

[0058] In one or more embodiments, the amount of B 2 O 3 is limited to less than or equal to 7.5 mol%. Without being bound by theory, it is believed that higher amounts of B 2 O 3 degrade the maximum CT value in the resulting chemically strengthened glass article. Additionally, the presence of B 2 O 3 increases the scratch resistance of the glass article and the strengthened glass article, as described herein. Without being bound by theory, relative to a glass article that does not contain B 2 O 3 , the inclusion of a three - coordinate network former (e.g., B 2 O 3 ) reduces the constraint on the glass network and allows the glass network to rearrange and densify when scratched (regardless of the indenter shape). Other components that behave the same or similarly to B 2 O 3 include P 2 O 5 , SiO 2 and Al 2 O 3. In one or more embodiments, the total amount of B is maximized to improve scratch resistance; however, the total amount of these components should not exceed the amount that would cause the maximum CT drop in the glass article after chemical strengthening. 2 O 3 、P 2 O 5 、SiO 2 and Al 2 O 3 such that the total amount of these components is maximized to improve scratch resistance; however, the total amount of these components should not exceed the amount that would cause the maximum CT drop in the glass article after chemical strengthening.

[0059] In one or more embodiments, the total amount of B 2 O 3 、P 2 O 5 、SiO 2 and Al 2 O 3 in the composition is greater than or equal to about 80 mol%. In some embodiments, the total amount of B 2 O 3 、P 2 O 5 、SiO 2 and Al 2 O 3 in the composition can be in the following ranges: about 80 mol% to about 94 mol%, about 80 mol% to about 92 mol%, about 80 mol% to about 90 mol%, about 80 mol% to about 88 mol%, about 80 mol% to about 86 mol%, about 82 mol% to about 94 mol%, about 84 mol% to about 94 mol%, about 86 mol% to about 94 mol%, or about 88 mol% to about 94 mol%, and all ranges and sub-ranges therebetween.

[0060] In one or more embodiments, the composition can include an R 2 O total amount in the following ranges: about 10 mol% to about 22 mol%, about 10 mol% to about 20 mol%, about 10 mol% to about 18 mol%, about 10 mol% to about 16 mol%, about 10 mol% to about 15 mol%, about 11 mol% to about 22 mol%, about 12 mol% to about 22 mol%, about 13 mol% to about 22 mol%, about 14 mol% to about 22 mol%, about 12 mol% to about 20 mol%, about 12 mol% to about 18 mol%, or about 13 mol% to about 17 mol%. In one or more embodiments, the composition can be substantially free of Rb 2 O, Cs 2 O, or can be substantially free of both Rb 2 O and Cs 2O. As used herein, the term "substantially free of" with respect to a component of a composition means that in the initial charge, the component is not added to the composition either actively or intentionally, but may be present as an impurity in an amount less than about 0.001 mole %.

[0061] In one or more embodiments, the composition comprises a certain amount of Li 2 O. For example, in one or more embodiments, the composition comprises Li 2 O in an amount greater than or equal to about 1 mole %, greater than or equal to about 2 mole %, greater than or equal to about 3 mole %, or greater than or equal to about 4 mole %. In one or more embodiments, the composition comprises an amount of Li 2 O: from about 2.5 mole % to about 11 mole %, from about 3 mole % to about 11 mole %, from about 3.5 mole % to about 11 mole %, from about 4 mole % to about 11 mole %, from about 4.5 mole % to about 11 mole %, from about 5 mole % to about 11 mole %, from about 5.5 mole % to about 11 mole %, from about 6 mole % to about 11 mole %, from about 5 mole % to about 10.5 mole %, from about 5 mole % to about 10 mole %, from about 5 mole % to about 9.5 mole %, from about 5 mole % to about 9 mole %, from about 5 mole % to about 8.5 mole %, from about 5 mole % to about 8 mole %, from about 5 mole % to about 7 mole %, from about 4 mole % to about 10.5 mole %, from about 4 mole % to about 10 mole %, from about 4 mole % to about 9.5 mole %, from about 4 mole % to about 9 mole %, from about 4 mole % to about 8.5 mole %, from about 4 mole % to about 8 mole %, from about 4 mole % to about 7 mole %, from about 4 mole % to about 6 mole %, from about 4.5 mole % to about 10 mole %, from about 5 mole % to about 10 mole %, from about 5.5 mole % to about 10 mole %, from about 6 mole % to about 10 mole %, from about 6.5 mole % to about 10 mole %, from about 7 mole % to about 10 mole %, from about 7.5 mole % to about 10 mole %, from about 8 mole % to about 10 mole %, from about 8.5 mole % to about 10 mole %, from about 9 mole % to about 10 mole %, or from about 5 mole % to about 6 mole %, and all ranges and subranges therebetween.

[0062] In one or more embodiments, Li 2 O and B 2 O 3 , P 2 O 5 , SiO 2 and Al 2 O 3 (B 2 O 3 +P 2 O 5 +SiO 2 +Al 2 O 3) is less than about 0.074 (e.g., less than or equal to about 0.073, less than or equal to about 0.072, less than or equal to about 0.071, less than or equal to about 0.07). In some embodiments, Li 2 O and B 2 O 3 、P 2 O 5 、SiO 2 and Al 2 O 3 is from about 0.065 to about 0.073. Adding some Li 2 O aids in ion exchange, e.g., enabling faster and / or deeper ion exchange, which provides a favorable CS curve. In some embodiments, the amount of Li 2 O can be balanced relative to B 2 O 3 、P 2 O 5 、SiO 2 and Al 2 O 3 (B 2 O 3 +P 2 O 5 +SiO 2 +Al 2 O 3 ), which provides scratch resistance. With an appropriate balance amount, such as maintaining this ratio of (Li 2 O to B 2 O 3 、P 2 O 5 、SiO 2 and Al 2 O 3 as described above), the glass can have favorable scratch resistance properties as well as drop properties (from the favorable CS curve).

[0063] In one or more embodiments, the composition has a certain amount of Na 2 O. For example, in one or more embodiments, the composition contains an amount of Na 2 O that is greater than or equal to about 0.5 mol%, greater than or equal to about 1 mol%, greater than or equal to about 2 mol%, greater than or equal to about 3 mol%, or greater than or equal to about 4 mol%. In one or more embodiments, the amount of Na 2 O is less than or equal to 10 mol%. In one or more embodiments, the composition includes an amount of Na 2O: from about 0.5 mole % to about 12 mole %, from 1 mole % to about 12 mole %, from 1.5 mole % to about 12 mole %, from 2 mole % to about 12 mole %, from about 2.5 mole % to about 12 mole %, from about 3 mole % to about 12 mole %, from about 3.5 mole % to about 12 mole %, from about 4 mole % to about 12 mole %, from about 4.5 mole % to about 12 mole %, from about 5 mole % to about 12 mole %, from about 5.5 mole % to about 12 mole %, from about 6 mole % to about 12 mole %, from about 3 mole % to about 12 mole %, from about 3 mole % to about 11 mole %, from about 3 mole % to about 10.5 mole %, from about 3 mole % to about 10 mole %, from about 3 mole % to about 9.5 mole %, from about 3 mole % to about 9 mole %, from about 3 mole % to about 8.5 mole %, from about 3 mole % to about 8 mole %, from about 3 mole % to about 7 mole %, from about 3.5 mole % to about 9 mole %, or from about 3 mole % to about 7.5 mole %, and all ranges and sub - ranges therebetween.

[0064] In one or more embodiments, the amount of Na 2 O in the composition is greater than the amount of Li 2 O. In some cases, the amount of Na 2 O can be greater than the total amount of Li 2 O and K 2 O. In one or more alternative embodiments, the amount of Li 2 O in the composition can be greater than the amount of Na 2 O or can be greater than the total amount of Na 2 O and K 2 O.

[0065] In one or more embodiments, the composition contains less than about 2 mole % K 2 O. In some cases, the composition can contain K 2 O in the following amounts: from about 0 mole % to about 2 mole %, from about 0 mole % to about 1.5 mole %, from about 0 mole % to about 1 mole %, from about 0 mole % to about 0.5 mole %, from about 0 mole % to about 0.2 mole %, or from about 0 mole % to about 0.1 mole %. In one or more embodiments, the composition can be substantially free of K 2 O.

[0066] In some embodiments, the glass composition may comprise one or more alkaline earth metal oxides (RO), such as MgO, CaO, SrO, BaO, and ZnO. In some embodiments, the total amount of RO may be a non-zero amount up to and including about 5 mol%. In one or more specific embodiments, the total amount of RO may be a non-zero amount up to and including about 4.5 mol%, up to and including about 4 mol%, up to and including about 3.5 mol%, up to and including about 3 mol%, up to and including about 2.5 mol%, up to and including about 2 mol%, up to and including about 1.5 mol%, or up to and including about 1 mol%. In one or more embodiments, the total amount of RO may be in the range of about 0.05 mol% to about 4.5 mol%, about 0.05 mol% to about 4 mol%, about 0.05 mol% to about 3.5 mol%, about 0.05 mol% to about 3 mol%, about 0.05 mol% to about 2.5 mol%, about 0.05 mol% to about 2 mol%, about 0.05 mol% to about 1.5 mol%, or about 0.05 mol% to about 1 mol%. In some embodiments, the total amount of RO may be in the range of about 1 mol% to about 4 mol%, about 1 mol% to about 3 mol%, or about 1 mol% to about 2 mol%.

[0067] In one or more embodiments, the composition may comprise a non-zero amount of MgO up to and including about 2 mol% or up to and including about 1 mol%. In some cases, the composition may be substantially free of MgO.

[0068] In one or more embodiments, the composition may comprise a non-zero amount of CaO up to and including about 2 mol% or up to and including about 1 mol%. In some cases, the composition may be substantially free of CaO.

[0069] In one or more embodiments, the composition may comprise a non-zero amount of SrO up to and including about 2 mol% or up to and including about 1 mol%. In some cases, the composition may be substantially free of SrO.

[0070] In one or more embodiments, the composition may comprise a non-zero amount of BaO up to and including about 2 mol% or up to and including about 1 mol%. In some cases, the composition may be substantially free of BaO.

[0071] In one or more embodiments, the composition can include a non-zero amount of ZnO, up to and including about 4.5 mole %, up to and including about 4 mole %, up to and including about 3.5 mole %, up to and including about 3 mole %, up to and including about 2.5 mole %, up to and including about 2 mole %, up to and including about 1.5 mole %, or up to and including about 1 mole %. In one or more embodiments, the total amount of ZnO can be in the range of: about 0.05 mole % to about 4.5 mole %, about 0.05 mole % to about 4 mole %, about 0.05 mole % to about 3.5 mole %, about 0.05 mole % to about 3 mole %, about 0.05 mole % to about 2.5 mole %, about 0.05 mole % to about 2 mole %, about 0.05 mole % to about 1.5 mole %, or about 0.05 mole % to about 1 mole %. In some embodiments, the total amount of ZnO can be in the range of: about 1 mole % to about 4 mole %, about 1 mole % to about 3 mole %, about 1 mole % to about 2 mole %, about 0.5 mole % to about 4 mole %, about 0.5 mole % to about 3 mole %, or about 0.5 mole % to about 2 mole %. In some cases, the composition can be substantially free of ZnO.

[0072] In one or more embodiments, the glass composition can contain ZnO and can be substantially free of MgO, CaO, SrO, and BaO. In one variation, the glass composition can contain ZnO and another RO (e.g., MgO, CaO, SrO, or BaO) and can be substantially free of other RO components. In one or more specific embodiments, the glass composition can contain only two of the alkaline earth metal oxides MgO, CaO, and ZnO and can be substantially free of the third alkaline earth metal oxide.

[0073] In one or more embodiments, the glass composition can include P in the following ranges 2 O 5 : about 0 mole % to about 10 mole %, about 0 mole % to about 8 mole %, about 0 mole % to about 7 mole %, about 0 mole % to about 6 mole %, about 0 mole % to about 4 mole %, about 0 mole % to about 3 mole %, about 0.1 mole % to about 10 mole %, about 0.1 mole % to about 8 mole %, about 0.1 mole % to about 6 mole %, about 0.1 mole % to about 5 mole %, about 0.1 mole % to about 4 mole %, about 0.1 mole % to about 3 mole %, about 0.5 mole % to about 5 mole %, about 0.5 mole % to about 4 mole %, about 0.5 mole % to about 3 mole %, about 1 mole % to about 5 mole %, about 1 mole % to about 4 mole %, about 1 mole % to about 3 mole %, or about 2 mole % to about 3 mole %. Without being limited by theory, including some P in the composition 2 O 5The liquidus behavior of the glass is managed and the high-temperature CTE is reduced, which enables the formation of thin glass articles. Without being limited to theory, it contains some P 2 O 5 also promotes the decomposition of zircon in the glass. In some embodiments, the composition contains a lower amount of Na 2 O (lower than that typically used in chemical strengthening, e.g., less than or equal to about 12 mol %), Li 2 O and P 2 O 5 , and the liquidus behavior exhibited by this combination provides the thermal history described herein, which enables the fusion forming of the glass. The presence of a specific thermal history in the glass article enables enhanced chemical strengthening.

[0074] In one or more embodiments, the composition may contain some TiO 2 . In such embodiments, the amount of TiO 2 present may be less than about 2 mol%, less than about 1 mol%, or less than about 0.5 mol%. In one or more alternative embodiments, the glass composition may be substantially free of TiO 2 .

[0075] In one or more embodiments, the composition may contain ZrO 2 . In such embodiments, the amount of ZrO 2 present may be less than about 2 mol%, less than about 1.5 mol%, 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 0.15 mol%, or less than about 0.1 mol%, and all ranges and sub-ranges therebetween. In one or more alternative embodiments, the glass composition may be substantially free of ZrO 2 , as defined herein.

[0076] In one or more embodiments, the composition may contain Fe 2 O 3 . In such embodiments, the amount of Fe 2 O 3 present may be less than about 1 mol%, less than about 0.9 mol%, less than about 0.8 mol%, less than about 0.7 mol%, less than about 0.6 mol%, less than about 0.5 mol%, less than about 0.4 mol%, less than about 0.3 mol%, less than about 0.2 mol%, less than about 0.1 mol%, and all ranges and sub-ranges therebetween. In one or more alternative embodiments, the glass composition may be substantially free of Fe 2 O 3, as defined herein.

[0077] In some embodiments, the composition may be formulated with about 0 - 2 mole % of at least one fining agent selected from the group consisting of: Na 2 SO 4 , NaCl, NaF, NaBr, K 2 SO 4 , KCl, KF, KBr, As 2 O 3 , Sb 2 O 3 and SnO 2 and any one or more of the following. The composition according to one or more embodiments may also contain about 0 - 2, about 0 - 1, about 0.1 - 2, about 0.1 - 1 or about 1 - 2 of SnO 2 . The glass compositions disclosed herein may be substantially free of As 2 O 3 and / or Sb 2 O 3 .

[0078] In one or more embodiments, specifically, the composition may comprise: 60 mole % to 65 mole % SiO 2 ; 12 mole % to about 18 mole % Al 2 O 3 ; 4 mole % to about 8 mole % Li 2 O; 0 mole % to about 4 mole % ZnO; 0 mole % to about 2 mole % MgO; 0 mole % to about 2 mole % TiO 2 ; 0.5 mole % to about 8 mole % B 2 O 3 ; 4 mole % to about 12 mole % Na 2 O; 0 mole % to about 2 mole % K 2 O; 0 mole % to about 2 mole % ZrO 2 ; 1 mole % to about 4 mole % P 2 O 5 ; and 0.05 mole % to about 0.2 mole % SnO 2 .

[0079] In one or more embodiments, specifically, the composition may comprise: 62 mole % to 65 mole % SiO 2 ; 12 mole % to about 18 mole % Al 2 O 3 ; 8 mole % to about 12 mole % Li 2 O; 0 mole % to about 2 mole % ZnO; 0 mole % to about 2 mole % MgO; 0 mole % to about 2 mole % TiO 2; 0.5 mol% to about 8 mol% B 2 O 3 ; 2 mol% to about 8 mol% Na 2 O; 0 mol% to about 2 mol% K 2 O; 0 mol% to about 2 mol% ZrO 2 ; 1 mol% to about 4 mol% P 2 O 5 ; and 0.05 mol% to about 0.2 mol% SnO 2 。

[0080] In one or more embodiments, specifically, the composition may comprise: 62 mol% to 68 mol% SiO 2 ; 10 mol% to about 18 mol% Al 2 O 3 ; 5 mol% to about 11 mol% Li 2 O; 0 mol% to about 2 mol% ZnO; 0 mol% to about 2 mol% MgO; 0 mol% to about 2 mol% TiO 2 ; 0.9 mol% to about 6 mol% B 2 O 3 ; 2 mol% to about 10 mol% Na 2 O; 0 mol% to about 2 mol% K 2 O; 0 mol% to about 2 mol% ZrO 2 ; 1 mol% to about 4 mol% P 2 O 5 ; and 0.05 mol% to about 0.2 mol% SnO 2 。

[0081] In some embodiments, the composition (or a glass article formed therefrom) has a liquidus viscosity that enables the formation of a glass article via a particular technique. As used herein, the term "liquidus viscosity" refers to the viscosity of molten glass at the liquidus temperature, where the term "liquidus temperature" refers to the temperature at which crystals first appear as molten glass is cooled from the melting temperature, or the temperature at which the last bit of crystal melts as the temperature is increased from room temperature.

[0082] In one or more embodiments, the composition (or glass article formed therefrom) exhibits a liquidus viscosity of about 100 - 500 kP. In some embodiments, the composition (or glass article formed therefrom) exhibits a liquidus viscosity of less than about 300 kilopoise (kP) or less. In some embodiments, the composition (or glass article formed therefrom) exhibits a liquidus viscosity of about 250 kP or less, about 200 kP or less, or about 180 kP or less. In some embodiments, the composition (or glass article formed therefrom) exhibits a liquidus viscosity greater than about 300 kP. In some embodiments, the composition (or glass article formed therefrom) exhibits a liquidus viscosity as follows: about 350 kP or greater, about 400 kP or greater, about 450 kP or greater, about 500 kP or greater, about 750 kP or greater, about 1000 kP or greater, or about 2000 kP or greater.

[0083] In one or more embodiments, measured over a temperature range from about 20 °C to about 300 °C, the composition (or glass article formed therefrom) exhibits a CTE as follows: about 55 x 10 -7 ppm / °C to about 80 x 10 -7 ppm / °C, about 58 x 10 -7 ppm / °C to about 80 x 10 -7 ppm / °C, or about 60 x 10 -7 ppm / °C to about 80 x 10 -7 ppm / °C.

[0084] In some embodiments, the composition (or glass article formed therefrom) exhibits a high temperature CTE (or liquid) CTE in the following range: about 8 x 10 -7 ppm / °C to about 18 x 10 -7 ppm / °C, about 10 x 10 -7 ppm / °C to about 18 x 10 - 7 ppm / °C, about 12 x 10 -7 ppm / °C to about 18 x 10 -7 ppm / °C, about 8 x 10 -7 ppm / °C to about 16 x 10 -7 ppm / °C, about 8 x 10 -7 ppm / °C to about 14 x 10 -7 ppm / °C, about 8 x 10 -7 ppm / °C to about 12 x 10 -7 ppm / °C or about 8 x 10 - 7 ppm / °C to about 10 x 10-7 ppm / °C.

[0085] In one or more embodiments, the composition or a glass article formed therefrom exhibits a Young's modulus in the following ranges: about 70 GPa to about 85 GPa, about 72 GPa to about 85 GPa, about 74 GPa to about 85 GPa, about 75 GPa to about 85 GPa, about 76 GPa to about 85 GPa, about 70 GPa to about 80 GPa, about 72 GPa to about 80 GPa, about 74 GPa to about 80 GPa, about 75 GPa to about 80 GPa, about 76 GPa to about 80 GPa, about 70 GPa to about 78 GPa, about 70 GPa to about 76 GPa, about 70 GPa to about 75 GPa, about 72 GPa to about 78 GPa, about 75 GPa to about 79 GPa, or about 70 GPa to about 77 GPa. The Young's modulus values stated in this disclosure refer to the measured values by a general type of resonant ultrasound spectroscopy technique presented in ASTM E2001-13, entitled "Standard Guide for Resonant Ultrasound Spectroscopy for Defect Detection in Both Metallic and Non-metallic Parts".

[0086] See Figure 3 , embodiments of the glass article 100 include: a first major surface 302, an opposite second major surface 304, and a thickness t 330 is defined between the first major surface and the second major surface. In one or more embodiments, the glass article may include the composition described herein.

[0087] In one or more embodiments, the thickness t may be less than or equal to about 3 millimeters (e.g., about 0.01 millimeter to about 3 millimeters, about 0.1 millimeter to about 3 millimeters, about 0.2 millimeter to about 3 millimeters, about 0.3 millimeter to about 3 millimeters, about 0.4 millimeter to about 3 millimeters, about 0.01 millimeter to about 2.5 millimeters, about 0.01 millimeter to about 2 millimeters, about 0.01 millimeter to about 1.5 millimeters, about 0.01 millimeter to about 1 millimeter, about 0.01 millimeter to about 0.9 millimeter, about 0.01 millimeter to about 0.8 millimeter, about 0.01 millimeter to about 0.7 millimeter, about 0.01 millimeter to about 0.6 millimeter, about 0.01 millimeter to about 0.5 millimeter, about 0.1 millimeter to about 0.5 millimeter, or about 0.3 millimeter to about 0.5 millimeter).

[0088] The glass article can be a substantially flat sheet, but other embodiments can employ articles that are curved or of any other shape or configuration. In some cases, the glass article can have a 3D or 2.5D shape. As a complement or alternative, for aesthetic and / or functional reasons, the thickness of the glass article can be constant along one or more dimensions, or can vary along one or more of its dimensions. For example, the edges of the glass article can be thicker than more central regions of the glass article. Depending on the application or use of the article, the length, width, and thickness dimensions of the glass article can also vary.

[0089] The glass article can be substantially transparent and free of light scattering. In one or more embodiments, when measured at a thickness of about 1 millimeter, the glass article can exhibit a light transmittance of greater than or equal to about 88% in the wavelength range of about 380 nm to about 780 nm.

[0090] The glass article can have a refractive index of about 1.45 - 1.55. As used herein, the refractive index value is relative to a wavelength of 550 nm.

[0091] The glass article can be characterized by the manner in which it is formed. For example, the glass article can be characterized as float - formable (i.e., formed by the float process), draw - down formable, specifically, fusion - formable or slot - drawable (i.e., formed by a draw - down process such as a fusion - draw process or a slot - draw process).

[0092] Some embodiments of the glass articles described herein can be formed by the float process. Float - formable glass articles can be characterized by a smooth surface and uniform thickness produced by causing molten glass to float on a bed of molten metal (commonly tin). In an exemplary process, molten glass is fed onto the surface of the molten tin bed to form a floating glass ribbon. As the ribbon flows along the tin bath, the temperature is gradually reduced until the ribbon solidifies into a solid glass article, which can be lifted from the tin onto rollers. Once out of the bath, the glass article can be further cooled and annealed to reduce internal stresses.

[0093] Some embodiments of the glass articles described herein can be formed by a draw - down process. The draw - down process produces glass articles with a uniform thickness and a relatively pristine surface. Since the average flexural strength of a glass article is controlled by the amount and size of surface flaws, the relatively pristine surface with minimal contact has a higher initial strength. Additionally, draw - down glass articles have a very flat and smooth surface that can be used in the final application without costly grinding and polishing.

[0094] Some embodiments of the glass article can be described as fusion formable (i.e., can be formed using a fusion draw process). The fusion process uses a draw vessel having a channel for receiving a molten glass feedstock. The channel has a weir that is open at the top on both sides of the channel along its length. When the channel is filled with the molten material, the molten glass overflows the weir. Under the action of gravity, the molten glass flows down as two flowing glass films from the outer surface of the draw vessel. The outer surfaces of these draw vessels extend downward and inward such that they join at the edge below the draw vessel. The two flowing glass films join at this edge to fuse and form a single flowing glass article. The advantage of the fusion draw method is that since the two glass films overflowing from the channel fuse together, neither outer surface of the resulting glass article contacts any part of the equipment. Thus, the surface properties of the fusion drawn glass article are not affected by such contact.

[0095] Some embodiments of the glass articles described herein can be formed by a slot draw process. The slot draw process is different from the fusion draw process. In the slot draw process, molten raw material glass is supplied to a draw vessel. The bottom of the draw vessel has an open slot having a nozzle extending along the length of the slot. The molten glass flows through the slot / nozzle and is drawn down as a continuous glass article and into an annealing zone.

[0096] In one or more embodiments, the glass articles described herein can exhibit an amorphous microstructure and can be substantially free of crystals or crystallites. In other words, the glass articles exclude glass-ceramic materials.

[0097] In one or more embodiments, the glass articles described herein can be chemically strengthened to impart a stress profile along the thickness t of the glass article. Figure 4 is a cross-sectional view of the stress profile of a chemically strengthened glass article 300 along its thickness 330 (shown along the x-axis). The magnitude of the stress is shown on the y-axis, and line 301 represents zero stress.

[0098] The stress profile 312 includes: a CS layer 315 (having a surface CS value 310) that extends from one or both of the first major surface 302 and the second major surface 304 to the DOC 330; and a CT layer 325 (having a maximum CT 320) that extends from the DOC 330 to the central portion of the article.

[0099] As used herein, DOC refers to the depth at which the stress within the glass article changes from compression to tension. At the DOC, the stress changes from a positive (compressive) stress to a negative (tensile) stress (e.g., Figure 4... thus exhibiting a zero stress value. Depending on the ion exchange treatment, the DOC can be measured by FSM or Scattering Light Polariscope (SCALP). When stress is generated in the glassware by exchanging potassium ions into the glassware, the FSM is used to measure the DOC. When stress is generated in the glassware by exchanging sodium ions into the glassware, the SCALP is used to measure the DOC. When stress is generated in the glass by exchanging both potassium and sodium ions into the glass, the DOC is measured by SCALP because it is believed that the exchange depth of sodium represents the DOC, and the exchange depth of potassium ions represents the change in the magnitude of the compressive stress (rather than a change in stress from compressive to tensile); in such glassware, the exchange depth of potassium ions is measured by FSM.

[0100] The CS layer has an associated depth or length 317 extending from the major surfaces 302, 304 to the DOC 330. The CT layer 325 also has an associated length or depth 327 (CT region or layer).

[0101] According to common practice in the art, unless otherwise stated, compressive or compressive stress is represented as negative stress (<0) and tensile or tensile stress is represented as positive stress (>0). However, throughout this specification, when referring to compressive stress CS, this does not consider positive or negative values, i.e., as described herein, CS = |CS| or the absolute value of CS.

[0102] The CS (including surface CS) is measured by a surface stress meter (FSM), using a commercial instrument (e.g., FSM - 6000) manufactured by Orihara Industrial Co., Ltd. (Japan). Surface stress measurement relies on the accurate measurement of the stress - optical coefficient (SOC), which is related to the birefringence of the glass. The SOC is then measured according to Procedure C (the glass disk method) described in ASTM standard C770 - 16, entitled "Standard Test Method for Measurement of Glass Stress - Optical Coefficient", the full text of which is incorporated herein by reference.

[0103] The known scattering light polariscope (SCALP) technique in the art is adopted to measure DOC and the maximum CT value. The refractive near field (RNF) method or SCALP can be used to measure the stress distribution. When the RNF method is adopted to measure the stress distribution, the maximum CT value provided by SCALP is used in the RNF method. Specifically, the stress distribution measured by RNF is in force balance and calibrated with the maximum CT value provided by the SCALP measurement. The RNF method is as described in U.S. Patent No. 8,854,623 entitled "Systems and methods for measuring a profile characteristic of a glass sample", the full text of which is incorporated herein by reference. Specifically, the RNF method includes placing a glass article close to a reference block, generating a polarization-switching beam (which switches between orthogonal polarizations at a rate of 1-50 Hz), measuring the amount of power in the polarization-switching beam, and generating a polarization-switching reference signal, wherein the amount of power measured in each orthogonal polarization is within 50% of each other. The method further includes passing the polarization-switching beam through the glass sample and the reference block, into different depths of the glass sample, and then using a delay optical system to delay the passed polarization-switching beam to reach a signal light detector, which generates a polarization-switching detector signal. The method further includes dividing the detector signal by the reference signal to form a normalized detector signal, and determining the profile characteristic of the glass sample from the normalized detector signal. Then the RNF curve is smoothed and used for the CT region. As described above, the FSM technique is used for the slope of the stress distribution in the surface CS and the CS region near the surface.

[0104] As described above, the stress distribution exhibited by the glass articles described herein is generated by chemical strengthening through ion exchange. During the ion exchange process, ions at or near the surface of the glass are replaced or exchanged with larger ions having the same valence state or oxidation state. In those embodiments where the glass article comprises an alkali aluminosilicate glass, the ions in the surface layer of the article and the larger ions are monovalent alkali metal cations, such as Li + , Na + , K + , Rb + and Cs + . Alternatively, the monovalent cations in the surface layer can be replaced with monovalent cations other than alkali metal cations, such as Ag + etc. In such embodiments, the monovalent ions (or cations) exchanged into the glass article generate stress.

[0105] The ion exchange process is typically carried out by immersing the glass article in a molten salt bath (or two or more molten salt baths), the molten salt bath containing larger ions to be ion exchanged with the smaller ions in the glass article. It should be noted that an aqueous salt bath can also be used. In addition, the bath composition can include more than one type of larger ion (e.g., Na + and K + ) or include a single type of larger ion. Those skilled in the art will understand that the parameters of the ion exchange process include but are not limited to bath composition and temperature, immersion time, number of immersions of the glass article in the salt bath (or salt baths), use of multiple salt baths, other steps (such as annealing and washing, etc.), which are generally determined by the following factors: the composition of the glass article (including the structure of the article and any crystalline phases present), and the DOC and CS required for the glass article obtained by strengthening. Exemplary molten salt bath compositions can include nitrates, sulfates, and chlorides of larger alkali metal cations. Typical nitrates include KNO 3 , NaNO 3 , LiNO 3 , NaSO 4 , and combinations thereof. The temperature of the molten salt bath is typically about 380 °C to up to about 450 °C, while the immersion time is about 15 minutes to up to 100 hours, depending on the glass article thickness, bath temperature, and glass (or monovalent ion) diffusion coefficient. However, different temperatures and immersion times can also be used.

[0106] In one or more embodiments, the glass article can be immersed in a molten salt bath of 100% NaNO 3 , 100% KNO 3 , or a combination of NaNO 3 and KNO 3 at a temperature of about 370 - 480 °C. In some embodiments, the glass article can be immersed in a mixed molten salt bath containing about 5 - 90% KNO 3 and about 10 - 95% NaNO 3 . In some embodiments, the glass article can be immersed in a mixed molten salt bath containing Na 2 SO 4 and NaNO 3 and having a wider temperature range (e.g., up to about 500 °C). In one or more embodiments, after immersion in the first bath, the glass article can be immersed in a second bath. The first and second baths can have different compositions and / or temperatures from each other. The immersion times in the first and second baths can vary. For example, the immersion in the first bath can be longer than the immersion in the second bath.

[0107] In one or more embodiments, the glass article can be immersed in a mixed molten salt bath containing NaNO3 and KNO 3 (e.g., 49% / 51%, 50% / 50%, 51% / 49%), at a temperature less than about 420 °C (e.g., about 400 °C or about 380 °C) for less than about 5 hours or even less than or equal to about 4 hours.

[0108] The ion exchange conditions can be adjusted to provide a "spike" or to increase the slope of the stress distribution at or near the surface of the resulting glass-based article. This spike can result in a greater surface CS value. Due to the unique properties of the glass compositions used in the glass articles described herein, this spike can be achieved by a single bath or multiple baths, the baths having a single composition or a mixed composition.

[0109] In one or more embodiments, when more than one monovalent ion is exchanged into the glass article, the different monovalent ions can be exchanged to different depths within the glass article (and different magnitudes of stress are generated at different depths within the glass article). The relative depths of the resulting stress-generating ions can be determined by different characteristics of the stress distribution and are responsible for different characteristics of the stress distribution.

[0110] In one or more embodiments, Na + and K + ions are exchanged into the glass article, and the depth of diffusion of Na + ions into the glass article is deeper than that of K + ions. The penetration depth of K+ ions ("potassium DOL") is different from DOC because it represents the depth of potassium penetration as a result of the ion exchange process. For the articles described herein, the potassium DOL is typically less than the DOC. A surface stress meter (e.g., a commercially available FSM-6000 surface stress meter manufactured by Orihara Industrial Co., Ltd. (Japan)) is used to measure the potassium DOL, which relies on an accurate measurement of the stress optical coefficient (SOC), as described above for CS measurement.

[0111] In one or more embodiments, a chemically strengthened glass article can exhibit a surface CS that is greater than or equal to 150 MPa or greater than or equal to about 200 MPa (e.g., greater than or equal to about 250 MPa, greater than or equal to about 300 MPa, greater than or equal to about 400 MPa, greater than or equal to about 450 MPa, greater than or equal to about 500 MPa, or greater than or equal to about 550 MPa). In some cases, the surface CS is greater than or equal to about 700 MPa. The surface CS can be up to about 900 MPa, up to about 1000 MPa, up to about 1100 MPa, or up to about 1200 MPa. In one or more embodiments, the surface CS can be about 400 - 900 MPa. The surface CS values provided herein can also include a maximum CS. In some embodiments, the surface CS is less than the maximum CS.

[0112] In one or more embodiments, a chemically strengthened glass article exhibits a maximum CT that is less than about 100 / √(t), less than or equal to about 95 / √(t), less than or equal to about 90 / √(t), less than or equal to about 85 / √(t), less than or equal to about 80 / √(t), or less than or equal to about 71.5 / √(t), where t is the thickness in mm. In one or more embodiments, the maximum CT can be greater than about 45 / √(t). In one or more embodiments, the maximum CT can be less than or equal to about 100 MPa, less than or equal to about 90 MPa, less than or equal to about 80 MPa, less than or equal to about 75 MPa, or less than or equal to about 70 MPa (e.g., less than or equal to about 60 MPa, less than or equal to about 55 MPa, less than or equal to about 50 MPa, or less than or equal to about 40 MPa). In one or more embodiments, the lower limit of the maximum CT can be 25 MPa, 40 MPa, or 50 MPa. In some embodiments, the maximum CT 320 can be in the range of about 25 - 100 MPa (e.g., about 25 MPa to about 90 MPa, about 25 MPa to about 85 MPa, about 25 MPa to about 80 MPa, about 25 MPa to about 75 MPa, about 25 MPa to about 70 MPa, about 25 MPa to about 65 MPa, about 40 MPa to about 100 MPa, about 40 MPa to about 90 MPa, about 40 MPa to about 80 MPa, about 40 MPa to about 75 MPa, about 40 MPa to about 70 MPa, about 40 MPa to about 65 MPa, about 45 MPa to about 80 MPa, about 50 MPa to about 80 MPa, or about 60 MPa to about 80 MPa).

[0113] The maximum CT 320 can be in the range of about 0.3t to about 0.7t, about 0.4t to about 0.6t, or about 0.45t to about 0.55t. It should be noted that one or more of the surface CS 310 and the maximum CT 320 can depend on the thickness of the glass article. For example, the maximum CT of a glass article having a thickness of about 0.8 mm can be less than or equal to about 75 MPa. When the thickness of the glass article decreases, the maximum CT can increase. In other words, the maximum CT increases as the thickness decreases (or as the glass article becomes thinner).

[0114] In some embodiments, the ratio of the maximum CT 320 to the surface CS 310 is about 0.01 to about 0.2 (e.g., about 0.01 to about 0.18, about 0.01 to about 0.16, about 0.01 to about 0.15, about 0.01 to about 0.14, about 0.01 to about 0.1, about 0.02 to about 0.2, about 0.04 to about 0.2, about 0.05 to about 0.2, about 0.06 to about 0.2, about 0.08 to about 0.2, about 0.1 to about 0.2, or about 0.12 to about 0.2). 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 48 times the maximum CT, up to 40 times the maximum CT, up to 20 times the maximum CT, up to 10 times the maximum CT, or up to 8 times the maximum CT. The surface CS can be from about 5 times to up to about 50 times the maximum CT.

[0115] In one or more embodiments, the stress distribution 312 includes a maximum CS, which is typically the surface CS 310, and can be located at one 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 the DOC 317. In one or more embodiments, the DOC 317 can be greater than or equal to about 0.1t. For example, the DOC 317 can be greater than or equal to about 0.12t, greater than or equal to about 0.14t, greater than or equal to about 0.15t, greater than or equal to about 0.16t, greater than or equal to about 0.17t, greater than or equal to about 0.18t, greater than or equal to about 0.19t, greater than or equal to about 0.20t, greater than or equal to about 0.21t, or up to about 0.25t. In one or more embodiments, the DOC 317 is substantially equal when measured from the first major surface 302 and the second major surface 304 of the article.

[0116] In one or more embodiments, the glass article includes potassium DOL of about 6 - 28 microns. In some embodiments, the potassium DOL can be expressed as a function of the thickness t of the glass article. In one or more embodiments, the potassium DOL can be from about 0.005t to about 0.07t. In some embodiments, the potassium DOL can be in the following ranges: from about 0.005t to about 0.07t, from about 0.005t to about 0.065t, from about 0.005t to about 0.06t, from about 0.005t to about 0.055t, from about 0.005t to about 0.05t, from about 0.005t to about 0.045t, from about 0.005t to about 0.04t, from about 0.005t to about 0.035t, from about 0.005t to about 0.03t, from about 0.005t to about 0.025t, from about 0.005t to about 0.02t, from about 0.005t to about 0.015t, from about 0.005t to about 0.01t, from about 0.006t to about 0.07t, from about 0.008t to about 0.07t, from about 0.01t to about 0.07t, from about 0.015t to about 0.07t, from about 0.02t to about 0.07t, from about 0.027t to about 0.05t, from about 0.03t to about 0.07t, or from about 0.01t to about 0.03t.

[0117] In one or more embodiments, the compressive stress value at the potassium DOL depth can be about 50 - 300 MPa. In some embodiments, the compressive stress value at the potassium DOL depth can be in the following ranges: from about 50 MPa to about 280 MPa, from about 50 MPa to about 260 MPa, from about 50 MPa to about 250 MPa, from about 50 MPa to about 240 MPa, from about 50 MPa to about 220 MPa, from about 50 MPa to about 200 MPa, from about 60 MPa to about 200 MPa, from about 70 MPa to about 200 MPa, from about 75 MPa to about 200 MPa, from about 80 MPa to about 200 MPa, from about 90 MPa to about 200 MPa, from about 100 MPa to about 200 MPa, from about 110 MPa to about 200 MPa, from about 120 MPa to about 200 MPa, from about 130 MPa to about 200 MPa, or from about 150 MPa to about 200 MPa, from about 60 MPa to about 300 MPa, from about 70 MPa to about 300 MPa, from about 75 MPa to about 300 MPa, from about 80 MPa to about 300 MPa, from about 90 MPa to about 300 MPa, from about 100 MPa to about 300 MPa, from about 110 MPa to about 300 MPa, from about 120 MPa to about 300 MPa, from about 130 MPa to about 300 MPa, or from about 150 MPa to about 300 MPa.

[0118] In one or more embodiments, the maximum chemical depth exhibited by the chemically strengthened glass article is greater than or equal to about 0.4t, greater than or equal to about 0.5t, greater than or equal to about 55t, or greater than or equal to about 0.6t. As used herein, the term "chemical depth" refers to the depth to which metal oxide or alkali metal oxide ions (e.g., metal ions or alkali metal ions) diffuse into the glass article and the depth at which the concentration of such ions reaches a minimum value, as determined by electron probe microanalysis (EPMA). As a result of ion exchange, ions diffuse into the chemically strengthened glass article. The maximum chemical depth refers to the maximum diffusion depth of any ion exchanged into the chemically strengthened glass article through the ion exchange process. For example, when the molten salt bath has more than one diffusing ionic species (i.e., a molten salt bath having both NaNO 3 and KNO 3 , different ionic species may diffuse into the chemically strengthened glass article to different depths. The maximum chemical depth is the maximum diffusion depth of all ionic species exchanged into the chemically strengthened glass article.

[0119] In one or more embodiments, the chemically strengthened glass article has a thickness of about 0.7 - 1.1 mm, a maximum CT of about 40 - 75 MPa, a surface CS of about 475 - 750 MPa, a DOC of about 0.11t - 0.17t, and a potassium DOL of about 6 - 30 microns.

[0120] In one or more embodiments, the strengthened glass article has a thickness of about 0.7 - 1.1 mm, a maximum CT of about 45 - 80 MPa, a surface CS of about 700 - 900 MPa, a DOC of about 0.11t - 0.2t, and a potassium DOL of about 8 - 26 microns.

[0121] In one or more embodiments, the chemically strengthened glass article has a thickness of about 0.7 - 1.1 mm, a maximum CT of about 70 - 100 MPa, a surface CS of about 700 - 900 MPa, and a DOC of about 0.17t - 0.2t.

[0122] In one or more embodiments, the stress distribution 312 can be described as having a parabolic shape. In some embodiments, the stress distribution along the region or depth where the glass article exhibits tensile stress exhibits a parabolic shape. In one or more specific embodiments, the stress distribution 312 does not include a flat stress (i.e., compressive or tensile) portion, or does not include a portion that exhibits substantially constant stress (i.e., compressive or tensile). In some embodiments, the stress distribution exhibited by the CT region is substantially free of flat stress or substantially constant stress. In one or more embodiments, the stress distribution 312 includes a tangent at all points between a thickness range of approximately 0t to up to approximately 0.2t and greater than 0.8t (or from approximately 0t to approximately 0.3t and greater than 0.7t) having a slope less than approximately -0.1 MPa / micron or greater than approximately 0.1 MPa / micron. In other embodiments, the stress distribution 312 includes a tangent at at least one point between a thickness range of approximately 0t to up to approximately 0.2t and at least one point of the stress distribution at a thickness greater than 0.8t (or from approximately 0t to approximately 0.3t and greater than or equal to 0.7t) having a slope less than approximately -0.1 MPa / micron or greater than approximately 0.1 MPa / micron. In some embodiments, the tangent slope can be less than approximately -0.2 MPa / micron or greater than approximately 0.2 MPa / micron. In some more specific embodiments, the tangent slope can be less than approximately -0.3 MPa / micron or greater than approximately 0.3 MPa / micron. In even more specific embodiments, the tangent slope can be less than approximately -0.5 MPa / micron or greater than approximately 0.5 MPa / micron. In other words, the stress distribution of one or more embodiments excludes points having a tangent slope along these thickness ranges (i.e., 0t to up to approximately 2t and greater than 0.8t, or approximately 0t to approximately 0.3t and greater than or equal to 0.7t), as described herein. Without being limited by theory, it is known that the points of the error function or quasi-linear stress distribution along these thickness ranges (i.e., approximately 0t to up to approximately 0.2t and greater than 0.8t, or approximately 0t to approximately 0.3t and greater than or equal to 0.7t) have a tangent with a zero slope or a tangent value close to zero, i.e., the following range: greater than approximately -0.1 MPa / micron to less than approximately 0.1 MPa / micron (indicating a flat or zero slope stress distribution along such thickness ranges, as shown in Figure 2 shown in 220). The glass article of one or more embodiments of the present disclosure does not exhibit such a stress distribution with a flat or zero slope stress distribution along these thickness ranges, as shown in Figure 3 shown.

[0123] In one or more embodiments, the glass article exhibits a stress profile that includes a maximum tangent slope and a minimum tangent slope within a thickness range of from about 0.1t to 0.3t and from about 0.7t to 0.9t. In some cases, the difference between the maximum tangent slope and the minimum tangent slope is less than or equal to about 3.5 MPa / micron, less than or equal to about 3 MPa / micron, less than or equal to about 2.5 MPa / micron, or less than or equal to about 2 MPa / micron.

[0124] In one or more embodiments, the glass article includes a stress profile 312 that is substantially free of any flat segments extending in a depth direction or along at least a portion of the thickness t of the glass article. In other words, the stress profile 312 increases or decreases substantially continuously along the thickness t. In some embodiments, the stress profile is substantially free of any flat segments in a depth direction having a length greater than or equal to about 10 microns, greater than or equal to about 50 microns, or greater than or equal to about 100 microns, or greater than or equal to about 200 microns. As used herein, the term "flat" means that the magnitude of the slope along the flat segment is less than about 0.55 MPa / micron, or less than about 0.22 MPa / micron. In some embodiments, one or more portions of the stress profile that are substantially free of any flat segments in a depth direction are present within a depth of the glass article that is greater than or equal to about 5 microns (e.g., greater than or equal to 10 microns or greater than or equal to 15 microns) from one or both of the first and second surfaces. For example, along a depth from about 0 microns to less than about 5 microns from the first surface, the stress profile may include a linear segment, but starting from a depth greater than or equal to about 5 microns from the first surface, the stress profile may be substantially free of flat segments. As used herein, "linear" includes linear segments having a flat slope and linear segments not having a flat slope.

[0125] In some embodiments, the stress profile may include a linear segment at a depth from about 0t up to about 0.1t, and may be substantially free of linear segments at a depth from about 0.1t to about 0.4t. In some embodiments, within a thickness range from about 0t to about 0.1t, the stress profile may have a slope (absolute value) magnitude of from about 20 MPa / micron to about 200 MPa / micron. As will be described herein, such embodiments may be formed by a single ion exchange process (the bath includes two or more alkaline salts, or the bath is a mixed alkaline salt bath) or by multiple (e.g., 2 or more) ion exchange processes.

[0126] In one or more embodiments, the shape of the stress profile along the CT region can be used Figure 3The glass article is described by (327) in. For example, in some embodiments, the stress distribution along the CT region (where the stress is in tension) can be approximated by an equation. In some embodiments, the stress distribution along the CT region can be approximated by Equation (1):

[0127] Stress(x) = Maximum T – (((CT n ·(n + 1)) / 0.5 n )·|(x / t) - 0.5| n )(1)

[0128] In Equation (1), Stress(x) is the stress value at the x position. Here, the stress is positive (tension). In Equation (1), Maximum T is the maximum tension value, and CT n is the tension value at n, which is less than or equal to Maximum T. Both Maximum T and CT n are positive values with the unit of MPa. The x value is the position along the thickness (t) with the unit of micrometer, and the range is from 0 to t; x = 0 is one surface ( Figure 3 in, 302), x = 0.5t is the center of the glass article where Stress(x) = Maximum CT, and x = t is the opposite surface ( Figure 3 in, 304). The Maximum T used in Equation (1) is equivalent to Maximum CT, which can be less than about 71.5 / √(t). In some embodiments, the Maximum T used in Equation (1) can be about 50 - 80 MPa (for example, about 60 MPa to about 80 MPa, about 70 MPa to about 80 MPa, about 50 MPa to about 75 MPa, about 50 MPa to about 70 MPa, or about 50 MPa to about 65 MPa), and n is a fitting parameter of 1.5 - 5 (for example, 2 - 4, 2 - 3, or 1.8 - 2.2) or about 1.5 - 2. In one or more embodiments, n = 2 can provide a parabolic stress distribution, and the stress distribution provided by an exponent deviating from n = 2 approximates a parabolic stress distribution. In one or more embodiments, CTn can be less than Maximum T, where there are compressive stress spikes on one or both main surfaces of the glass article. In one or more embodiments, when there are no compressive stress spikes on one or both main surfaces of the glass article, CTn is equal to Maximum T.

[0129] In some embodiments, the stress distribution can be altered by heat treatment. In such embodiments, the heat treatment can be performed before any ion exchange process, between ion exchange processes, or after all ion exchange processes. In some embodiments, the heat treatment can reduce the magnitude of the slope of the stress distribution at or near the surface. In some embodiments, when a steeper or larger slope is desired at the surface, the ion exchange process can be performed after the heat treatment to provide a "spike" or to increase the slope of the stress distribution at or near the surface.

[0130] In one or more embodiments, the stress distribution 312 of the chemically strengthened glass article is due to a non-zero concentration of metal oxide that varies along a portion of the thickness. This variation in metal oxide concentration can be referred to herein as a metal oxide concentration gradient. In some embodiments, the concentration of the metal oxide in the chemically strengthened glass article is non-zero and varies along a thickness range from about 0t to about 0.3t. In some embodiments, the concentration of the metal oxide is non-zero and varies along a thickness range from about 0t to about 0.35t, from about 0t to about 0.4t, from about 0t to about 0.45t, or from about 0t to about 0.48t. The metal oxide can be described as generating stress in the glass article. The variation in concentration can be continuous along the above thickness range. The concentration variation can include a change in metal oxide concentration of about 0.2 mole % along a thickness segment of about 100 microns. Such variation can be measured by methods known in the art, including microprobes. A metal oxide with a non-zero concentration that varies along a portion of the thickness can be described as generating stress in the glass article.

[0131] The variation in the metal oxide concentration of the chemically strengthened glass article can be continuous along the above thickness range. In some embodiments, the concentration variation can be continuous along a thickness segment of about 10 - 30 microns. In some embodiments, the concentration of the metal oxide decreases from the first surface to a value at a point between the first and second surfaces and increases from that value to the second surface.

[0132] The concentration of the metal oxide in the chemically strengthened glass article can include more than one metal oxide (e.g., a combination of Na 2 O and K 2 O). In some embodiments, when two metal oxides are used and when the ionic radii are different from each other, at a shallow depth, the concentration of the ion with the larger radius is greater than the concentration of the ion with the smaller radius, while at a deeper depth, the concentration of the ion with the smaller radius is greater than the concentration of the ion with the larger radius. For example, when a single bath containing Na and K is used in the ion exchange process, at a shallower depth, the concentration of K + ions in the glass article is greater than that of Na+ the concentration of ions, while at greater depths, Na + ions have a greater concentration than K + ions. This is at least in part due to the size of the monovalent ions that exchange into the glass with smaller monovalent ions. In such glass articles, due to the larger number of larger ions (i.e., K + ions) at or near the surface, the regions at or near the surface include a larger CS. A stress distribution with a steeper slope at or near the surface (i.e., a spike in the stress distribution at the surface) can exhibit this larger CS.

[0133] As described above, by chemically strengthening the glass article, a concentration gradient or variation of one or more metal oxides is produced, wherein a plurality of first metal ions in the glass article exchange with a plurality of second metal ions. The first ions can be ions of lithium, sodium, potassium, and rubidium. The second metal ions can be ions of one 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 article as their oxides (e.g., Na 2 O, K 2 O, Rb 2 O, Cs 2 O, or a combination thereof).

[0134] In one or more embodiments, the metal oxide concentration gradient of the chemically strengthened glass article extends through most or the entire thickness t of the glass article, including the CT layer 327. In one or more embodiments, the concentration of the metal oxide is greater than or equal to about 0.5 mole % in the CT layer 327. In some embodiments, the concentration of the metal oxide can be greater than or equal to about 0.5 mole % (e.g., greater than or equal to about 1 mole %) along the entire thickness of the glass article, and is maximum at the first surface 302 and / or the second surface 304, and decreases substantially constantly to a point between the first surface 302 and the second surface 304. At this point, the concentration of the metal oxide is the lowest along the entire thickness t; however, the concentration is also non-zero at this point. In other words, the non-zero concentration of the particular metal oxide extends along most of the thickness t (as described herein) or along the entire thickness t. In some embodiments, the lowest concentration of the particular metal oxide is in the CT layer 327. The total concentration of the particular metal oxide in the glass article can be about 1 - 20 mole %.

[0135] In one or more embodiments, a chemically strengthened glass article includes a first metal oxide concentration and a second metal oxide concentration such that the first metal oxide concentration in a first thickness range from about 0t to about 0.5t is about 0 - 15 mole percent, and the second metal oxide concentration in a second thickness range from about 0 microns to about 25 microns (or about 0 - 12 microns) is about 0 - 10 mole percent; however, the concentration of one or both of the first metal oxide and the second metal oxide is non-zero along most or all of the thickness of the glass article. The chemically strengthened glass article may include an optional third metal oxide concentration. The first metal oxide may include Na 2 O, and the second metal oxide may include K 2 O.

[0136] In embodiments of the chemically strengthened glass article, the concentration of the metal oxide can be determined by the baseline amount of the metal oxide in the glass article prior to modification to include the metal oxide concentration gradient.

[0137] In one or more embodiments, the non-strengthened and chemically strengthened glass articles exhibit a Knoop lateral cracking scratch threshold of greater than or equal to about 6 N, greater than or equal to about 8 N, greater than or equal to about 10 N, greater than or equal to about 12 N, greater than or equal to about 14 N, or greater than or equal to about 16 N. In some embodiments, the non-strengthened and chemically strengthened glass articles exhibit a Knoop lateral scratch threshold of from about 6 N to about 26 N, from about 8 N to about 26 N, from about 10 N to about 26 N, from about 12 N to about 26 N, from about 14 N to about 26 N, from about 15 N to about 26 N, from about 16 N to about 26 N, from about 18 N to about 26 N, from about 6 N to about 24 N, from about 6 N to about 22 N, from about 6 N to about 20 N, from about 6 N to about 18 N, from about 6 N to about 16 N, or from about 18 N to about 24 N. The Knoop lateral cracking threshold can be measured on the first major surface 302 or the second major surface 304 of the non-strengthened or chemically strengthened glass article. As used herein, the Knoop lateral cracking threshold is the starting point of lateral cracking (3 or more lateral cracks in 5 indentation events). In the Knoop lateral cracking scratch threshold test, first, a Knoop indenter is used to scratch the sample and the article of glass with a dynamic or increasing load to identify the range of lateral crack initiation loads for the sample population. Once the range of load that can be applied is identified, a series of increasing constant load scratches (each load being at least 3 or greater) are performed to identify the Knoop scratch threshold. The Knoop scratch threshold range can be determined by comparing the test specimen to one of the following 3 failure modes: 1) a continuous lateral surface crack that is more than twice the width of the groove; 2) breakage is limited within the groove, but there are lateral surface cracks less than twice the width of the groove and there is visible breakage to the naked eye; or 3) there are large subsurface lateral cracks that are greater than twice the width of the groove and / or there are medium cracks at the apex of the scratch.

[0138] Embodiments of the (both non-strengthened and chemically strengthened) glass articles can be used as cover glasses for handheld electronic devices and touchable displays. The glass articles can also be used in displays (or as display articles) (such as billboards, point-of-sale systems, computers, navigation systems, etc.), architectural articles (walls, fixtures, panels, windows, etc.), transportation articles (e.g., automotive applications, trains, airplanes, marine vessels, etc.), appliances (e.g., washing machines, dryers, dishwashers, refrigerators, etc.), or any article that requires a certain degree of crack resistance.

[0139] Specifically, the glass articles described herein are thin and, when chemically strengthened as described herein, exhibit a stress profile that is typically achievable only by tempering a thick glass article (e.g., having a thickness of about 2 mm or 3 mm or greater). The glass articles exhibit a unique stress profile along their thickness. In some cases, the surface CS of the glass articles described herein is greater than that of tempered glass articles. In one or more embodiments, the compressive stress layer of the glass article extends deeper into the glass article (where the decrease and increase in CS is more gradual compared to known chemically strengthened glass articles), such that the glass article exhibits significantly improved fracture resistance, even when the glass article or a device incorporating the same is dropped onto a hard surface (e.g., granite) or a rough surface (e.g., asphalt). The maximum CT value exhibited by the glass articles of one or more embodiments is greater than that of some known chemically strengthened glass articles.

[0140] In one or more embodiments, when subjected to the Annular Ring on Ring (AROR) test, the chemically strengthened glass articles described herein exhibit improved surface strength. The strength of a material is defined as the stress at which fracture occurs. The AROR test is a surface strength measurement for testing flat glass specimens, and ASTM C1499 - 09 (2013), entitled "Standard Test Method for Monotonic Equibiaxial Flexural Strength of Advanced Ceramics at Ambient Temperature", is used as the basis for the AROR test method described herein. The entire content of ASTM C1499 - 09 is incorporated herein by reference. In one embodiment, prior to performing the ring on ring test, the glass specimen is abraded with 90 - mesh silicon carbide (SiC) particles, and the particles are delivered to the glass sample using the method and equipment described in Appendix A2 (entitled "abrasion Procedures") of ASTM C158 - 02 (2012), entitled "Standard Test Methods for Strength of Glass by Flexure (Determination of Modulus of Rupture)". The entire content of ASTM C158 - 09, particularly Appendix A2, is incorporated herein by reference.

[0141] Before the ring-on-ring test, the surface of the glass article is abraded as described in Appendix 2 of ASTM C158-02 using the equipment shown in Figure A2.1 of ASTM C158-02 to standardize and / or control the surface defect state of the sample. Abrasive material is sandblasted onto the surface 110 of the glass article at an air pressure of 304 kPa (44 psi) with a load of 15 psi. After establishing the air flow, 5 cm 3 of abrasive material is poured into the funnel and, after introducing the abrasive material, the sample is sandblasted for 5 seconds.

[0142] For the AROR test, a chemically strengthened glass article having at least one abraded surface 410 as shown in Figure 5 is placed between two concentric rings of different sizes to determine the equibiaxial flexural strength (i.e., the maximum stress that the material can sustain when subjected to flexure between two concentric rings), also as schematically shown in Figure 5 . In the AROR configuration 400, the abraded glass article 410 is supported by a support ring 420 having a diameter of D 2 . A force F is applied to the surface of the glass article via a load ring 430 having a diameter of D 1 by a load cell (not shown).

[0143] The diameter ratio D 1 / D 2 of the load ring to the support ring can be approximately 0.2 - 0.5. In some embodiments, D 1 / D 2 is approximately 0.5. The load ring and the support rings 130, 120 should be concentrically aligned within 0.5% of the diameter D 2 of the support ring. At any load, the load cell used for testing should be accurate within ±1% of the selected range. In some embodiments, the test is conducted at a temperature of 23 ± 2 °C and a relative humidity of 40 ± 10%.

[0144] For the fixture design, the radius r of the protruding surface of the load ring 430 is h / 2 ≤ r ≤ 3h / 2, where h is the thickness of the glass article 410. The load ring and the support rings 430, 420 are typically made of hardened steel with a hardness HR c > 40. The AROR fixture is commercially available.

[0145] The target failure mechanism for the AROR test is to observe the breakage of the glass article 410 originating from the surface 430a within the load ring 430. For data analysis, failures that exist outside of this region (i.e., between the load ring 430 and the support ring 420) are ignored. However, due to the thinness and high strength of the glass article 410, large deflections greater than 1 / 2 the specimen thickness h are sometimes observed. Thus, a high percentage of failures originating below the load ring 430 are often observed. Stress cannot be accurately calculated without knowledge of the stress development and source of failure within and below the ring for each specimen (collectively referred to as strain gage analysis). Thus, the AROR test focuses on measuring the peak load at failure in response.

[0146] The strength of a glass article depends on the presence of surface flaws. However, the likelihood of the presence of flaws of a given size cannot be accurately predicted because the strength of glass is inherently statistical. Thus, a probability distribution is typically used as a statistical representation of the data obtained.

[0147] In some embodiments, the glass articles described herein have a surface or equibiaxial flexure strength greater than or equal to 20 kgf and up to about 30 kgf, which is determined by the AROR test using a load of 25 psi or even 45 psi to abrade the surface. In other embodiments, the surface strength is greater than or equal to 25 kgf, and in other embodiments, greater than or equal to 30 kgf.

[0148] In some embodiments, the chemically strengthened glass articles described herein can be characterized by the performance of an Inverted Ball on Sandpaper (IBoS) test. The IBoS test is a dynamic component-level test that simulates the primary mechanisms of failure due to damage introduction plus bending commonly found in glass articles used in mobile electronic devices or handheld electronic devices, as Figure 6 schematically shown. In the field, damage introduction occurs on the top surface of the glass article ( Figure 7 a in ). The fracture begins on the top surface of the glass article, and the damage penetrates the glass article ( Figure 7 b in ) or the fracture starts to propagate from a bend on the top surface or from an internal portion of the glass article ( Figure 7 c in ). The IBoS test is designed to simultaneously introduce damage to the surface of the glass and apply bending under dynamic loading. In some cases, the glass article exhibits improved drop performance when it includes a compressive stress as compared to the same glass article without the compressive stress.

[0149] The IBoS test apparatus is as Figure 6As shown schematically. Device 500 includes a test support 510 and a ball 530. The ball 530 is a rigid ball or a solid ball, for example, a stainless steel ball, etc. 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 a glassware sample 518. The test support 510 includes a solid base 512, which comprises a hard rigid material, such as granite, etc. A sheet 514 with abrasive material disposed on its surface is placed on the upper surface of the solid base 512 such that the surface with the abrasive material faces upward. In some embodiments, the sheet 514 is sandpaper with a 30-mesh surface (and in other embodiments, a 180-mesh surface). The glassware sample 518 is fixed in place on the sheet 515 by a sample holder 515 such that there is an air gap 516 between the glassware sample 518 and the sheet 514. The air gap 516 between the sheet 514 and the glassware sample 518 allows the glassware sample 518 to bend and bend onto the abrasive surface of the sheet 514 after being impacted by the ball 530. In one embodiment, the glassware sample 218 is clamped at all corners to maintain bending only at the ball impact point and ensure repeatability. In some embodiments, the sample holder 514 and the test support 510 are adapted to accommodate a sample thickness of up to about 2 mm. The air gap 516 is about 50 - 100 μm. The air gap 516 is adjusted for different material stiffnesses (Young's modulus) (but also including the Young's modulus and thickness of the sample). An adhesive strip 520 can be used to cover the upper surface of the glassware sample to collect debris in the event of breakage of the glassware sample 518 after being impacted by the ball 530.

[0150] Various materials can be used as the abrasive surface. In a particular embodiment, the abrasive surface is sandpaper, such as silicon carbide or alumina sandpaper, engineered sandpaper, or any abrasive material known to those skilled in the art with comparable hardness and / or sharpness. In some embodiments, 30-mesh sandpaper can be used because its surface topography is more uniform than that of concrete or asphalt, and the particle size and sharpness produce the desired level of specimen surface damage.

[0151] In one aspect, Figure 8Disclosed is a method 600 for performing an IBoS test using the device 500 described above. In step 610, the glass article is placed in the test holder 510 described above and fixed in the sample holder 515 such that an air gap 516 is formed between the glass article sample 518 and the sheet 514 having a ground surface. The method 600 assumes that the sheet 514 having a ground surface has already been placed in the test holder 510. However, in some embodiments, the method may include placing the sheet 514 in the test holder 510 such that the surface having the abrasive material faces upward. In some embodiments (step 610a), a bonding strip 520 is applied to the upper surface of the glass article sample 518 before the glass article sample 518 is fixed in the sample holder 510.

[0152] In step 520, a solid ball 530 having a predetermined mass and size is dropped from a predetermined height h onto the upper surface of the glass article sample 518 such that the ball 530 impacts the upper surface (or the bonding strip 520 adhered to the upper surface) at or near the approximate center of the upper surface (e.g., within 1 mm, or 3 mm, or 5 mm, or 10 mm of the center). After the impact in step 520, the degree of damage to the glass article sample 518 is determined (step 630). As described above, the term "rupture" herein refers to when a crack propagates through the entire thickness and / or the entire surface of a substrate when an object is dropped or impacts the substrate.

[0153] In the method 600, the sheet 518 having a ground surface can be replaced after each drop to avoid the "aging" effect that has been observed in the reuse of other types of (e.g., concrete or asphalt) drop test surfaces.

[0154] Various predetermined drop heights h and increments are typically used in the method 600. For example, a minimum drop height (e.g., about 10 - 20 cm) can be employed at the start of the test. Then, for successive drops, the height can be increased in fixed increments or varying increments. Once the glass article sample 518 breaks or ruptures, the test described in the method 600 is stopped (step 631). Alternatively, if the drop height h reaches the maximum drop height (e.g., about 100 cm) without rupture occurring, the drop test of the method 300 can also be stopped, or step 520 can be repeated at the maximum height until rupture occurs.

[0155] In some embodiments, at each predetermined height h, each glass article sample 518 is only subjected to the IBoS test of the method 600 once. However, in other embodiments, each sample can be subjected to multiple tests at each height.

[0156] If the glass article sample 518 ruptures ( Figure 8In step 631), the IBoS test according to method 600 is stopped (step 640). If breakage caused by a dropped ball at a predetermined drop height is not observed (step 632), the drop height is increased in a predetermined increment (step 634), such as 5, 10, or 20 cm, and steps 620 and 630 are repeated until sample breakage is observed (631) or the maximum test height (636) is reached without sample breakage occurring. When step 631 or 636 is reached, the test according to method 600 is terminated.

[0157] When subjected to the inverted ball on sandpaper (IBoS) test described above, when the ball is dropped from a height of 100 cm onto the glass surface, embodiments of the glass articles described herein have a survival rate of at least about 60% (i.e., the survival rate is greater than or equal to 60%). For example, when 3 out of 5 identical (or nearly identical) samples (i.e., having an approximate same composition and, when tempered, having an approximate same compressive stress and compressive depth or compressive stress layer as described herein) pass the IBoS drop test without breakage after being dropped from a given height (here 100 cm), the glass article is described as having a 60% survival rate when dropped from the given height. In other embodiments, the survival rate of the tempered glass article in the 100 cm IBoS test is at least about 70% (greater than or equal to 70%), in other embodiments, at least about 80% (greater than or equal to 80%), and in other embodiments, at least about 90% (greater than or equal to 90%). In other embodiments, in the IBoS test, the survival rate of the tempered glass article dropped from a height of 100 cm is at least about 60% (greater than or equal to 60%), in other embodiments, at least about 70% (greater than or equal to 70%), in other embodiments, at least about 80% (greater than or equal to 80%), and in other embodiments, at least about 90% (greater than or equal to 90%). In one or more embodiments, in the IBoS test, the survival rate of the tempered glass article dropped from a height of 150 cm is at least about 60% (greater than or equal to 60%), in other embodiments, at least about 70% (greater than or equal to 70%), in other embodiments, at least about 80% (greater than or equal to 80%), and in other embodiments, at least about 90% (greater than or equal to 90%).

[0158] To determine the survival rate of glass articles when dropped from a predetermined height using the IBoS test method and apparatus described above, at least 5 identically (or approximately identically) samples of the glass article (i.e., of approximately the same composition and, if tempered, of approximately the same compressive stress and compressive depth or layer depth) may be tested, but a greater number (e.g., 10, 20, 30, etc.) of samples may also be subjected to testing to increase the confidence level of the test results. Each sample is dropped once from a predetermined height (e.g., 100 cm or 150 cm), or dropped from gradually increasing heights without breaking until a predetermined height is reached, and visual (i.e., with the naked eye) inspection for evidence of breakage (formation of cracks and propagation through the entire thickness and / or entire surface of the sample) is performed. If no breakage is observed after dropping from the predetermined height, the sample is considered to "pass" the drop test, and if breakage is observed when the sample is dropped from a height less than or equal to the predetermined height, the sample is considered to "fail" (or "not pass"). The survival rate is determined as the percentage of the number of samples that pass the drop test. For example, if 7 out of a group of 10 samples do not break when dropped from the predetermined height, the survival rate of the glass would be 70%.

[0159] Another aspect of the present disclosure relates to an apparatus including the glass article described herein. For example, the apparatus may include a device containing a display or any device that requires strengthened thin glass. In one or more embodiments, the apparatus is an electronic device, which may include a handheld device, such as, for example, a mobile phone, laptop computer, tablet, mp3 player, navigation device, etc., or a stationary device, such as, for example, a computer, electronic display, in-vehicle infotainment system, billboard, point-of-sale system, navigation system, etc.). In some embodiments, the glass article described herein may be incorporated into building articles (walls, fixtures, panels, windows, etc.), transportation articles (e.g., glass windows or interior surfaces in vehicle applications, trains, airplanes, marine vessels, etc.), appliances (e.g., washing machines, dryers, dishwashers, refrigerators, etc.), or any article that requires a certain degree of fracture resistance. As Figure 9 shown, the electronic device 1000 may include a glass article 100 according to one or more embodiments described herein. The device 1000 includes: a housing 1020 having a front surface 1040, a back surface 1060, and side surfaces 1080; electronic components (not shown) that are at least partially located within or fully located within the housing and that at least include a controller, a memory; and a display 1120 located on or adjacent to the front surface of the housing. The display glass article 100 is disposed as a cover on or over the surface of the housing, such that it is over the display 1120. In some embodiments, the glass article may be used as a back cover.

[0160] Another aspect of the present disclosure pertains to a method of forming an embodiment of the chemically strengthened glass article described herein. The method includes: providing a glass article having a first surface and a second surface, the first and second surfaces defining a thickness less than or equal to about 3 millimeters; and creating a stress distribution in the glass article. In one or more embodiments, creating the stress distribution includes: ion-exchanging a plurality of alkaline ions into the glass article to form a non-zero concentration of alkali metal oxide that varies along most of the thickness (as described herein) or along the entire thickness. In one example, creating the stress distribution includes immersing the glass article in a molten salt bath that contains Na + 、K + 、Rb + 、Cs + nitrates or combinations thereof, at a temperature greater than or equal to about 350 °C (e.g., about 350 - 500 °C). In one example, the molten bath can contain NaNO 3 、KNO 3 or combinations thereof, and the temperature can be about less than or equal to 485 °C. In another example, the bath can contain a mixture of NaNO 3 and KNO 3 , and the temperature is about 460 °C. The glass article can be immersed in the bath for greater than or equal to about 2 hours, up to about 48 hours (e.g., about 2 - 10 hours, about 2 - 8 hours, about 2 - 6 hours, about 3 - 10 hours, or about 3.5 - 10 hours).

[0161] In some embodiments, the method can include immersing the glass article in a single bath, or in successive immersion steps, immersing the glass article in more than one bath. For example, two or more baths can be used sequentially. The composition of the one or more baths can include a single metal (e.g., Ag + 、Na + 、K + 、Rb + or Cs + ), or combinations of metals in the same bath. When more than one bath is used, the baths can have the same or different compositions and / or temperatures from each other. The immersion time in each such bath can be the same or can vary to provide the desired stress distribution.

[0162] In one or more embodiments of the method, a second bath or a subsequent bath can be employed to create a larger surface CS. In some cases, the method includes: immersing the glass article in the second bath or a subsequent bath to create a larger surface CS without significantly affecting the DOC. In such embodiments, the second bath or a subsequent bath can include a single metal (e.g., KNO 3 or NaNO 3 ) or a mixture of metals (KNO3 and NaNO 3 )。The temperature of the second bath or subsequent baths can be adjusted to produce a greater surface CS. In some embodiments, the immersion time of the glass article in the second bath or subsequent baths can be adjusted to produce a greater surface CS without significantly affecting the DOC. For example, the immersion time in the second bath or subsequent baths can be less than 10 hours (e.g., less than or equal to about 8 hours, less than or equal to about 5 hours, less than or equal to about 4 hours, less than or equal to about 2 hours, less than or equal to about 1 hour, less than or equal to about 30 minutes, less than or equal to about 15 minutes, or less than or equal to about 10 minutes).

[0163] In one or more embodiments, the method includes immersing the glass article in a 100% NaNO 3 molten salt bath at a temperature of 390 °C for a duration of about 2 - 10 hours (e.g., 7 hours). In one or more embodiments, the method includes immersing the glass article in an 80% KNO 3 and 20% NaNO 3 molten salt bath at a temperature of 390 °C for a duration of about 2 - 10 hours (e.g., 7 hours). In one or more embodiments, the method includes immersing the glass article in a 60% KNO 3 and 40% NaNO 3 molten salt bath at a temperature of 390 °C for a duration of about 2 - 10 hours (e.g., 4.5, 5, 6, or 7 hours). In one or more embodiments, the method includes immersing the glass article in a 60% KNO 3 and 40% NaNO 3 molten salt bath at a temperature of 390 °C for a duration of about 2 - 10 hours (e.g., 4.5, 5, 6, or 7 hours).

[0164] In one or more embodiments, the method can include imparting a thermal history to the glass article before ion-exchanging the glass article (i.e., immersing the glass article in a molten salt bath). In one or more embodiments, imparting a thermal history includes annealing or fictivating the glass article before ion-exchanging the glass article (i.e., immersing the glass article in a molten salt bath). In one or more embodiments, annealing the glass article includes heating the glass article to a temperature at which the glass article exhibits a 10 13.2 Poise viscosity. In one or more embodiments, the method includes fictivating the glass article to a 10 11 Poise temperature (i.e., the viscosity of the glass article is approximately 10 11The temperature of the anneal. As used herein, annealing a glass article or fictivating a glass article includes heating the glass article to a temperature such that the glass article exhibits a specified viscosity (i.e., 10 11 poise for fictivation and 10 13.2 poise for annealing), and then rapidly quenching the glass article to room temperature. Without being limited by theory, annealing or fictivating the glass article in this manner restricts or locks in the glass structure corresponding to that viscosity. Providing this thermal history to the glass article provides a structure that aids in chemical strengthening. Additionally, selecting this annealing or fictivation method and the associated viscosity level mimics the thermal history of fusion-formed glass, and can therefore be applied to glass that is not fusion-formed to produce the same thermal history and enhanced chemical strengthening. Thus, in one or more embodiments, the method includes annealing or fictivating a float-formed glass article, a slot-drawn glass article, or other non-fusion-formed glass article.

[0165] In one or more alternative embodiments, the method can include one or more heat treatment steps that can be used in combination with the ion exchange processes described herein. Heat treatment includes heat treating the glass article to obtain a desired stress distribution. In some embodiments, heat treatment includes annealing, tempering, or heating the glass article to a temperature of about 300 - 600 °C. The heat treatment can last from 1 minute up to about 18 hours. In some embodiments, heat treatment can be used after one or more ion exchange processes, or heat treatment can be used between ion exchange processes.

[0166] In one or more embodiments, the glass article can be acid polished or otherwise treated to remove or reduce the effect of surface flaws.

[0167] As used and recorded herein, the strain point temperature is determined by the fiber elongation method of ASTM C336-71(2015); the annealing temperature is determined by the fiber elongation method of ASTM C336-71(2015); the softening point is determined by the fiber elongation method of ASTM C338-93(2013); and the liquidus viscosity is determined as follows: First, the liquidus temperature of the glass is determined in accordance with ASTM C829-81(2015) entitled "Standard Practice for Measurement of Liquidus Temperature of Glass by the Gradient Furnace Method", and then the viscosity of the glass at the liquidus temperature is determined in accordance with ASTM C965-96(2012) entitled "Standard Practice for Measuring Viscosity of Glass Above the Softening Point".

[0168] In embodiments described herein that include the following material properties, testing is performed as follows, where the material property is that the threshold failure impact force exhibited by the article is greater than a certain force value when the article is bent to impart a tensile stress of 100 MPa. According to one or more embodiments, "threshold failure impact force" refers to the minimum impact force sufficient to cause an observable crack on the surface of the article, as described above with respect to Figure 7 that described. In one or more embodiments, the articles on which the "threshold failure impact force" test is performed are sheets having the following thicknesses: 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, or 2 mm.

[0169] Reliability testing of devices is essential for how they perform over their useful life. Device drop tests are commonly used to understand the reliability of handheld electronic devices (e.g., smartphones, tablets, laptops, etc.) after a drop event (e.g., the phone drops in a parking lot), as these events can compromise the functionality of the device. One consideration for devices is the reliability of the cover glass used in these devices. Breakage or cracking of the cover glass of a handheld electronic device can result in a device that is unavailable to the user and / or safety issues. Understanding the limitations of the cover material and how it relates to the device design is essential for improving the performance of the cover glass.

[0170] Typically, actual devices are dropped to understand their reliability. However, this can become very expensive and is only feasible when the device design has been finalized and the device has been manufactured. To address these drawbacks, alternative test media (reusable mock-ups similar in size and weight to the device) are used to simulate the device for performing cover glass performance tests. These alternative media help understand the glass's ability to meet consumer requirements and provide useful design feedback for cover glass survivability (e.g., bevel design). However, constructing the alternative media and conducting the (drop) tests are time-consuming and rather expensive. Therefore, instead, a device is used to test the surface of glass-based articles (e.g., cover glass for mobile electronic devices) to simulate the failure modes observed in the field, which are mainly a combination of stress (bending) and introduced damage. This known failure mode is recreated using a surface impact test based on the component level. Extensive tests have been conducted using this device, and through these tests, it has been recognized that certain glass compositions and ion exchange stress distributions improve cover glass survivability.

[0171] The device includes a simple pendulum-based dynamic impact test with a surface range from flat to curved, where the test specimen of the glass-based article is mounted to the oscillator hammer of the pendulum and then used to cause the test specimen to contact the impact surface (which can be a smooth or rough surface). To conduct the test, the sample is loaded onto a fixture and then pulled back from the pendulum's equilibrium position and released to create a dynamic impact on the impact surface. The test simulates a drop event such that the glass / specimen is the moving part while the surface is the stationary part. The available curved surfaces are a simulation of the stress numbers (bending stress) obtained from field failures. The glass-based article is the moving part that moves to impact the impact surface (which is the stationary part), replicating the device (moving part) dropping from a given height onto the surface (stationary part).

[0172] It is known that failure modes vary with the speed and curvature of the introduced breakage. Different from other component-level tests based on quasi-static load application used to characterize the performance of cover glasses (e.g., Ring-on-Ring (ROR), Indentation Fracture Threshold (IFT), and Abrasive Ring-on-Ring (ARoR), which involve slow bending through quasi-static load application after the introduction of breakage), this test is inherently dynamic. Additionally, as the demand for thin cover materials in mobile device applications has increased and become very popular, it has become crucial to have component-level tests to evaluate different thin cover materials. This test can be used to predict the potential drop performance response of such thin glasses, as it validates the credibility of the evaluation of glass materials with different compositions and IOX treatments down to a thickness of 0.3 mm. This test method enables a quick assessment of glass impact energy and the associated impact forces in a simple manner, which is comparable to the effects produced by system-level drop tests.

[0173] Now refer to Figures 10 - 15 , which shows an embodiment of an apparatus 1100 for performing a "Surface Threshold Failure Impact Force Test" on a brittle substrate, which includes a pendulum 1102, and the pendulum 1102 includes an oscillator hammer 1104 attached to a pivot 1106. The oscillator hammer on the pendulum is a heavy object suspended relative to the pivot and is connected to the pivot by an arm. Thus, the oscillator hammer 1104 shown in the figure is connected to the pivot 1106 by an arm 1108, and the arm 1108 can be in the form of a rope, or a rod, or multiple rods (e.g., 2 rods as shown in the figure). As Figure 14 best shown, the oscillator hammer 1104 has a balance position 1105, which is shown as a dashed line, such that the angle β is zero. In other words, the arm 1108 is not in a lifted position.

[0174] The oscillator hammer 1104 can simply be a brittle substrate fixed to the lower end of the arm 1108. In one or more embodiments, the oscillator hammer 1104 includes a base 1110 for receiving the brittle substrate. As Figure 15 shown in more detail, the base 1110 for receiving the brittle substrate 1112 has at least two ends 1114, 1116, an inner surface 1113, and an outer surface 1115. The base 1110 has a first end 1120 and a second end 1112, a curved surface 1124, which defines a radius of curvature between the first end 1120 and the second end 1122. The base 1110 can be made of any suitable material to provide a platform for fixing the substrate for impact testing, which will be described below. Suitable materials for the base 1110 can include wood, metal, ceramic, or a combination thereof. The curved surface 1124 has a vertex 1125.

[0175] The device 1100 according to one or more embodiments further includes a first fixture 1130 and a second fixture 1132 for holding at least two ends 1114, 1116 of the brittle substrate 1112 and applying a force such that the brittle substrate 1112 bends around the curved surface 1124 and conforms the brittle substrate to the radius of curvature. By bending the brittle substrate 1112, the brittle substrate has a vertex 1127 that conforms to the vertex 1125 of the curved surface 1124. In one or more specific embodiments, the curvature of the curved surface 1124 and the brittle substrate 1112 can be a fixed radius or a composite radius. The first fixture 1130 and the second fixture 1132 are respectively clamps, and in a specific embodiment, are hinged clamps, as Figure 15 shown. However, other types of fixtures such as bar clamps, C-clamps or other suitable fixtures can be used to hold the ends of the brittle substrate.

[0176] The device 1100 according to one or more embodiments further includes a roughened surface, which can be an abrasive sheet having an abrasive surface, for placement in contact with the outer surface 1115 of the substrate 1112. The abrasive sheet is attached to the impact surface 1150 (of the impact object 1140 described below) by a double-sided tape such that the abrasive surface of the abrasive sheet faces the curved surface 1124 on which the substrate 1112 is mounted. In other specific embodiments, the abrasive sheet includes sandpaper, which can have a grit size of 30 - 400 mesh, or 100 - 300 mesh (e.g., 180 mesh). A suitable sandpaper is Indasa Plus Line P180 mesh sandpaper. According to one or more embodiments, the sandpaper is cut into 25 mm 2 sheets, and if the sheet bends during the cutting process, the sandpaper is flattened.

[0177] The device 1100 further includes an impact object 1140 placed as follows, such that when the oscillator hammer 1104 is released from an angle β greater than zero degrees relative to the equilibrium position 1105, the curved surface 1124 of the oscillator hammer 1104 (or the substrate 1112 mounted on the curved surface 1124) comes into contact with the impact surface 1150 of the impact object 1140 (or the grinding side of the grinding sheet arranged on the impact surface 1150). In the illustrated embodiment, the impact object 1140 is an L-shaped bracket fixed to the platform 1142, and the impact object 1140 is fixed to the platform 1142 by a screw 1144. The impact object 1140 can also be fixed by other suitable mechanisms (e.g., bolts, rivets, clamps, etc.). The platform 1142 includes a stopper 1146, which can hold the device 1100 at the end of the workbench 1148. In the illustrated embodiment, when the oscillator hammer 1104 comes into contact with the impact object 1140 at the impact surface 1150, the impact object 1140 is fixed and does not move. The impact surface 1150 can be a separate element, which can move in the x-y plane in the slot 1152, as Figure 13 best shown. Alternatively, the impact surface 1150 does not need to move relative to the impact object 1140. In one or more embodiments, the size and shape of the oscillator hammer 1104 and the base 1100 are as follows: when the brittle substrate is fixed to the base 1110 and when the oscillator hammer 1104 is released from a position at an angle β greater than zero degrees relative to the equilibrium position 1105, the bending radius and impact force experienced by the brittle substrate 1112 simulate the bending radius of the chemically strengthened cover glass of a mobile phone or a tablet device when a user of the mobile phone or the tablet device drops the mobile phone or the tablet device onto a grinding surface.

[0178] The radius of curvature of the curved surface 1124 on the base 1110 is selected such that a bending tensile force of 100 MPa is provided when the substrate bends around the curved surface 1124, such that the tensile force is an externally applied tensile force caused by the stress of the substrate bending. Thus, when the substrate bends, the tensile force is located at the apex 1125 of the brittle substrate. The radius of curvature is 0.25 - 1.5 m, for example 0.5 - 1 m.

[0179] The distance between the first fixing device 1130 and the second fixing device 1132 is the length of the cover glass of a mobile phone or a tablet. For example, the distance between the first fixing device 1130 and the second fixing device 1132 is 50 - 500 mm.

[0180] Another aspect of the present disclosure pertains to an impact testing method for brittle sheets, which includes: bending a brittle sheet having a contact surface to provide a bent sheet having a radius of curvature and a vertex on the contact surface; and at the vertex, using a pendulum to impact the bent sheet with an impact object. In one embodiment, the bent sheet is connected to the pendulum oscillator hammer. In one embodiment, the bent sheet connected to the pendulum oscillator hammer is placed such that the impact object contacts the vertex of the contact surface. The range of the radius of curvature is as follows: it simulates the radius of curvature of the chemically strengthened or thermally strengthened cover glass of a mobile phone or a tablet device when a user of the mobile phone or the tablet device drops the mobile phone or the tablet device onto an abrasive surface, wherein the dropping event causes the edge of the device to first contact the abrasive surface (different from the case where the surface first drops, where the device usually impacts the abrasive surface in a direction such that the contact surface is substantially parallel to the abrasive surface).

[0181] Place the abrasive sheet on the impact surface 1150 at a position such that after the arm 1108 swings, it contacts the vertex of the brittle sheet. Fix the abrasive sheet and the impact object with a bilateral strip.

[0182] Now refer to Figure 10 and 11 , specific non-limiting details of the device operation include a pointer notch 1200 on the pivot 1106, which can point to various test positions 1202, that is, positions where the arm 1108 is at an angle β relative to the equilibrium position 1105, and the position where the pendulum starts to move. The pointer notch 1200 can be paired with various test positions 1202, which can be any suitable number of test positions, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc., with an increment up to 50 or more. The device 1100 may also include a locking device, which can be in the form of a nut 1204 to lock the arm 1108 in the desired rotational orientation about its central longitudinal axis, such that the base 1110 is at a right angle to the impact surface 1150 of the impact object 1140.

[0183] The device 1100 simulates an actual phone dropping event according to one or more embodiments. The impact energy E and the average impact force are provided by the following equations:

[0184] E = mgL{1 - cosβ}

[0185]

[0186] where m = the mass of the pendulum 1102 (including the swing arm 1108, the oscillator weight 1104, and the base 1110), L = the arm length, g = the acceleration of free fall, vf is the initial impact velocity (i.e., the velocity when the glass first contacts the impact surface 1150 of the impact object 1140), and vi is the final impact velocity (i.e., the velocity at which the glass leaves the impact surface 1150 of the impact object 1140, or in other words, the velocity at which the glass first separates from the impact surface 1150 of the impact object 1140), and Δt = the contact interaction time (i.e., the duration during which the glass is in contact with the impact surface 1150 of the impact object 1140). The contact interaction time is measured by a high-speed video camera by multiplying the number of frames in which the contact between the glass and the impact surface 1150 is observed by the number of frames taken by the high-speed video camera per unit time. The average force equation can be used for samples that have not broken, i.e., samples loaded into the device 1100 before the test have not broken. To obtain the average value for a given set of samples, the test is based on at least 5 identical (or approximately identical) samples of glass-based articles (i.e., approximately the same composition, and if strengthened, approximately the same compressive stress and compressive depth or layer depth), but a larger number (e.g., 10, 20, 30, etc.) of samples can also be tested to increase the confidence level of the test results. When the mass and length of the swing arm are known, the angle β is set to a selected position, and the impact force can be calculated and used to simulate the impact that occurs on the device when dropped from a specific height. For example, when dropped from a height of 1 meter, the average force experienced by the substrate-covered glass on a 130 g mobile phone device is calculated to be 800 N. Using the mass, arm length, and angle β, the Figures 10 - 15 device 1100 shown can be used to replicate this force.

[0187] Now refer to Figure 16 and 17 , which show an embodiment of a device 1600 for performing an "Edge Threshold Failure Impact Force Test" on a brittle substrate, which includes a pendulum 1602, and the pendulum 1604 includes an oscillator weight 1604 attached to a pivot 1606. The oscillator weight on the pivot is a heavy object suspended relative to the pivot and is connected to the pivot by an arm. Thus, Figure 16 the oscillator weight 1604 shown is connected to the pivot 1106 by an arm 1608 (shown in the form of two rods). Similar to the surface threshold impact force test, the oscillator weight 1604 has an equilibrium position where the angle β is zero. In other words, the arm 1608 is not in a raised position. Due to the similarity with the surface threshold failure impact force test, only their differences will be described for the edge threshold failure impact force test.

[0188] The oscillator hammer 1604 includes a flat sample holder 1610, a stopper 1620, and a support 1622. The sample holder 1610 is connected to the arm 1608. The stopper 1620 and the support are connected to the sample holder 1610. The sample 1712 is mounted on the sample holder 1610, the stopper 1620 abuts against one edge of the sample 1712, and then the support 1622 is fixed to the sample holder 1610 by a screw 1624 (etc.). The sample 1712 may be provided with strips on one surface to retain debris for further analysis of the fracture pattern after testing.

[0189] The apparatus 1600 also includes an impact object 1640 placed as follows such that when the oscillator hammer 1604 is released from an angle β greater than zero degrees relative to the equilibrium position, the corners (1701, 1702, 1703, or 1704) of the substrate 1712 mounted on the sample holder 1610 come into contact with the impact surface 1650 of the impact object 1640 (or the grinding side of the abrasive sheet disposed on the impact surface 1650). In the illustrated embodiment, the impact object 1640 is an L-shaped bracket fixed to the platform 1642, and the impact object 1640 is fixed to the platform 1644 by a screw 1642. The impact object 1640 may also be fixed by other suitable mechanisms (e.g., bolts, rivets, clamps, etc.). The platform 1642 includes a stopper 1646 that can hold the apparatus 1600 at the end of the workbench 1648. In the illustrated embodiment, when the oscillator hammer 1604 comes into contact with the impact object 1640 at the impact surface 1650, the impact object 1640 is fixed and does not move.

[0190] As Figure 17As shown, the sample 1712 is mounted to the fixture 1610 such that only one corner 1701 contacts the impact surface 1650 at a time. The sample 1712 can be reoriented in the fixture 1610 such that the remaining corners 1702, 1703, and 1704 contact the impact surface 1650 in turn. During sample testing, only one drop is performed on any particular corner 1701 - 1704, thereby avoiding the introduction of cumulative damage, i.e., such that the impact from one test does not affect subsequent tests. The test is performed by raising the pendulum to a first height (corresponding to a first impact force and a first impact energy) and impacting one corner of the sample 1712 against the impact surface 1650. If no breakage or fragmentation is observed, the sample is reoriented and tested on the opposite corner of the diagonal that has not been previously tested, and the test is performed at a higher pendulum height (increasing the impact force and impact energy). A typical test protocol includes testing corners 1701 and 1703 of a particular sample, or testing corner 1702 of the sample and then testing corner 1704; corners on the same end of the sample are not tested (e.g., if 1701 is tested, then 1704 is not tested). The testing is repeated until breakage or fragmentation is observed. If a sample (opposite corners on two diagonals) is tested without failure (breakage or fragmentation), a second sample of the same type (composition, ion exchange conditions, thickness, and edge finish) is tested in a similar manner, and as many samples as possible are tested in this way to obtain the pendulum height (impact force and impact energy) at which breakage or fragmentation occurs for that same type (composition, ion exchange conditions, thickness, and edge finish).

[0191] Example

[0192] The various embodiments are further illustrated by the following examples.

[0193] Example 1

[0194] Batch compositions 1 - 13 are formed into glass articles. The resulting glass articles are fictitiously annealed to 10 11 Poisson temperature and then ion exchanged according to ion exchange conditions A - C for different durations to form chemically strengthened glass articles having the stress distributions described herein. Ion exchange condition A includes immersion in a single bath of 100% NaNO at a temperature of 390°C 3 Ion exchange condition B includes immersion in a single bath of 80% KNO at a temperature of 390°C 3 and 20% NaNO 3 Ion exchange condition C includes immersion in a single bath of 60% KNO at a temperature of 390°C 3 and 40% NaNO 3In a single bath. Then, the stress distribution and the properties of the Knoop scratch lateral cracking threshold of the chemically strengthened glass articles were measured. Table 1 includes the properties of Compositions 1-13 and the non-strengthened glass articles. Table 2 shows the ion exchange conditions and properties of the chemically strengthened glass articles formed from Compositions 1-13.

[0195] Table 1: Properties of Compositions 1-13 and the Compositions and the Resulting Glass Articles

[0196]

[0197]

[0198] Table 1 (continued): Properties of Compositions 1-13 and the Compositions and the Resulting Glass Articles The density was determined by the buoyancy method of ASTM C693-93(2013).

[0199]

[0200]

[0201] Table 1 (continued): Properties of Compositions 1-13 and the Compositions and the Resulting Glass Articles

[0202]

[0203]

[0204] Table 2: Ion Exchange Conditions, Stress Distribution Properties, and Knoop Scratch Lateral Cracking Thresholds of Chemically Strengthened Glass Articles Formed from Compositions 1-13

[0205]

[0206]

[0207] Table 2 (continued): Ion Exchange Conditions, Stress Distribution Properties, and Knoop Scratch Lateral Cracking Thresholds of Chemically Strengthened Glass Articles Formed from Compositions 1-13

[0208]

[0209]

[0210] Table 2 (continued): Ion Exchange Conditions, Stress Distribution Properties, and Knoop Scratch Lateral Cracking Thresholds of Chemically Strengthened Glass Articles Formed from Compositions 1-13

[0211]

[0212]

[0213] Table 2 (continued): Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of chemically strengthened glass articles formed from Compositions 1-13

[0214]

[0215]

[0216] Table 2 (continued): Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of chemically strengthened glass articles formed from Compositions 1-13

[0217]

[0218]

[0219] Table 2 (continued): Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of chemically strengthened glass articles formed from Compositions 1-13

[0220]

[0221] Table 2 (continued): Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of chemically strengthened glass articles formed from Compositions 1-13

[0222]

[0223]

[0224] Table 2 (continued): Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of chemically strengthened glass articles formed from Compositions 1-13

[0225]

[0226]

[0227] Table 2: Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of chemically strengthened glass articles formed from Compositions 1-13

[0228]

[0229] Table 2 (continued): Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of chemically strengthened glass articles formed from Compositions 1-13

[0230]

[0231]

[0232] In Table 2, DOC is recorded as a fraction of the thickness and can be used to calculate the absolute value of DOC in mm. For example, after 2 hours of ion exchange under ion exchange condition A, the DOC recorded for the chemically strengthened glass article formed from Composition 1 is 0.14 of the thickness (i.e., 14% of the thickness or 0.14t). The absolute value of DOC is 0.11 mm, calculated by multiplying the thickness by 14% (0.14 * 0.79).

[0233] In Compositions 1 - 13, the amount of B 2 O 3 is increased in increments of about 0.5 mol% in sequence from Composition 1 to Composition 13. At the same time, from Composition 1 to Composition 13, the relative amounts of Al 2 O 3 and Na 2 O decrease in increments of about 0.15 mol% and 0.35 mol% respectively in sequence. These compositional changes reduce the average network connectivity of the glass - forming material while maintaining the maximum CT value exhibited by the chemically strengthened glass article. In addition, the resulting chemically strengthened glass articles exhibit an increased Knoop scratch lateral cracking threshold, as shown in Table 2. For example, the chemically strengthened glass articles formed from Compositions 10 - 12 exhibit a high Knoop scratch lateral cracking threshold while still maintaining a deep DOC value (e.g., greater than 0.12t) and a relatively high surface CS value (e.g., greater than 500 MPa). The chemically strengthened glass articles formed from Composition 6 and ion - exchanged for 4.5 hours, 5 hours, 6 hours, and 7 hours under ion exchange condition B exhibit an even higher surface CS value (e.g., greater than 700 MPa) while maintaining a deep DOC value (0.12t or greater).

[0234] Samples of the composition of Example 6 were subjected to ion exchange, which included: immersion in a bath of 30% KNO 3 and 70% NaNO 3 at 380 °C for 4 hours, followed by immersion in a bath of 93% KNO 3 and 7% NaNO 3 at 380 °C for 40 minutes. The resulting samples had a CS of 777 MPa, a potassium DOL of 8.2 microns, and a CT of 66.4 MPa. Then these samples were tested using the surface threshold failure impact force test (with 180 - mesh sandpaper on the impact surface) and the edge threshold failure impact force test (with 30 - mesh sandpaper on the impact surface). The results are shown in Figure 18 and 19As shown. All samples are 0.8 mm thick and have a bullnose edge finish. For the surface threshold failure impact force test, the samples were given a bending radius of 0.4 m (meters), with a length by width of 110 mm x 56 mm.

[0235] As can be seen from Figure 18 it, the samples of Example 6 (as described above) were able to withstand an average surface impact force of 851 N. Even further, each of the 10 samples tested withstood an average surface impact force of 851 N; no sample cracked. Thus, for at least 10 samples, the samples of Example 6 were able to withstand a maximum surface impact force and an average surface impact force exceeding 400 N, such as: 400 N to 851 N, 450 N to 851 N, 500 N to 851 N, 550 N to 851 N, 600 N to 851 N, 650 N to 851 N, 700 N to 851 N, 750 N to 851 N, or 800 N to 851 N.

[0236] In contrast, samples of Comparative Example 1 and Comparative Example 2 (C2) having the same dimensions and the same finish as the samples of Example 6 were tested in the same manner as the samples of Example 6; the results are as Figure 18 shown. In mole %, the nominal composition of Comparative Example 1 is: 57.4% SiO 2 、16.1% Al 2 O 3 、17.1% NaO, 2.8% MgO, and 6.54% P 2 O 5 . The samples of Comparative Example 1 were subjected to ion exchange, which included: immersion in a bath of 60% KNO 3 and 40% NaNO 3 at a temperature of 450 °C for 7 hours, followed by immersion in a bath of 99.5% KNO 3 and 0.5% NaNO 3 at a temperature of 390 °C for 12 minutes. The resulting samples had a surface CS of 870 MPa and a potassium DOL of 74.3 microns. As can be seen from Figure 18 it, the samples of Comparative Example 1 (C1 data) were able to withstand a maximum surface impact force of less than 400 N, and for 10 samples, the average surface impact force was 313 N. Comparative Example 2 had a nominal composition consistent with the glass manufactured by Asahi Glass Company (Japan), i.e., the following nominal composition in mole %: 64.8% SiO 2 、7.7% Al 2 O 3, 12.4% NaO, 4% K2O, 10.4% MgO, 0.3% CaO, 0.1% SrO, 0.5% ZrO 2 , and 0.03% BaO. The sample of Comparative Example 2 had a surface CS of 802 MPa and a potassium DOL of 24 microns. From Figure 18 it can be seen that the sample of Comparative Example 2 (C2 data) was able to withstand a maximum surface impact force of about 200 N, and for 10 samples, the average surface impact force was 152 N.

[0237] For the edge threshold failure impact force test, for each sample type, the points marked with arrows are the impact forces (in Newtons, N) and impact energies (in Joules, J) at which visual observation (i.e., with the naked eye) of glass breakage begins. That is, the arrows mark the points at which the samples did not pass the test, and at the data point immediately to the left of the marked one, all the samples passed the test. For example, in the case of the sample of Example 6, the arrow marks the data point at a 110-degree rotation angle, with an incident impact energy of 1.58 J and an average impact force slightly higher than 500 N; at this data point, the sample did not pass the test, but all the samples did pass the test at a 95-degree rotation angle, an incident impact energy of 1.28 J, and an average impact force of about 450 N. Higher values mean improved performance. All the samples were 0.8 mm thick and had a 2.5D finish of 0.3 mm at the edge.

[0238] From Figure 19 it can be seen that the sample of Example 6 (as described above) was able to withstand an edge impact force of about 200 N to about 450 N, for example: about 225 N to 450 N, about 250 N to about 450 N, about 275 N to about 450 N, about 300 N to about 450 N, about 325 N to about 450 N, about 350 N to about 450 N, about 400 N to about 450 N, or about 425 N to about 450 N. Similarly, the sample of Example 6 (prepared as described above) was able to withstand an edge incident impact energy of about 0.43 J to about 1.3 J, for example: about 0.44 J to about 1.3 J, about 0.45 J to about 1.3 J, about 0.46 J to about 1.3 J, about 0.47 J to about 1.3 J, about 0.48 J to about 1.3 J, about 0.49 J to about 1.3 J, about 0.5 J to about 1.3 J, about 0.55 J to about 1.3 J, about 0.6 J to about 1.3 J, about 0.65 J to about 1.3 J, about 0.7 J to about 1.3 J, about 0.75 J to about 1.3 J, about 0.8 J to about 1.3 J, about 0.9 J to about 1.3 J, about 1.0 J to about 1.3 J, about 1.1 J to about 1.3 J, about 1.2 J to about 1.3 J.

[0239] In contrast, samples of Comparative Example 3 and Comparative Example 4 having the same dimensions and the same edge finishing as the sample of Example 6 were tested in the same manner as the sample of Example 6; the results are as Figure 19 shown. In mol%, the nominal composition of Comparative Example 3 is: 63.6% SiO 2 、15.7% Al 2 O 3 、10.8% NaO、6.2% Li 2 O、1.2% ZnO、and 2.5% P 2 O 5 . The sample of Comparative Example 3 was subjected to ion exchange, which included: immersion in a bath of 75% KNO 3 and 25% NaNO 3 at a temperature of 380 °C for 3 hours and 36 minutes, followed by immersion in a bath of 91% KNO 3 and 9% NaNO 3 at a temperature of 380 °C for 30 minutes. The resulting sample had a surface CS of about 800 MPa to about 830 MPa, a DOC of about 155 microns, a CT of about 70 MPa, a potassium DOL of about 8 microns, and a CS of about 130 MPa at the potassium DOL. As can be seen from Figure 19 , the sample of Comparative Example 3 (C3 data) was able to withstand an edge impact force of about 200 N, and an edge impact energy of 0.42 J (50-degree rotation angle). In mol%, the nominal composition of Comparative Example 4 is: 64.6% SiO 2 、5.1 B 2 O 3 、14% Al 2 O 3 、13.8% NaO、and 2.4% MgO. After the ion exchange treatment, the surface CS of the sample was 870 MPa, the potassium DOL was 46 microns, and the CT was about 57 MPa. As can be seen from Figure 19 , the sample of Comparative Example 4 (C4 data) was able to withstand an edge impact force of less than 100 N, and an edge impact energy of less than 0.1 J (less than 20-degree rotation angle).

[0240] Example 2

[0241] Batch composition 14 - 26 was compounded and a glass article was formed. Then, the resulting glass article was annealed to the 10 13 Poisson temperature or fictitiously annealed to 10 11The soaking temperature (as shown in Table 4), and then ion exchange is carried out according to ion exchange condition B for different durations to form a chemically strengthened glass article. The resulting chemically strengthened glass article exhibits a stress distribution having the properties described herein, and the stress distribution and the Knoop scratch lateral cracking threshold are measured. Table 3 includes the properties of Compositions 14-26 and the unstrengthened glass article. Table 4 shows the ion exchange conditions and properties of the chemically strengthened glass articles formed from Compositions 14-26.

[0242] Table 3: Properties of Compositions 14-26 and the compositions and resulting glass articles

[0243]

[0244]

[0245] Table 3 (continued): Properties of Compositions 14-26 and the compositions and resulting glass articles

[0246]

[0247]

[0248] Table 3 (continued): Properties of Compositions 14-26 and the compositions and resulting glass articles

[0249]

[0250]

[0251] Table 4: Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of the chemically strengthened glass articles formed from Compositions 14-26

[0252]

[0253]

[0254] Table 4 (continued): Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of the chemically strengthened glass articles formed from Compositions 14-26

[0255]

[0256]

[0257] Table 4 (continued): Ion exchange conditions, stress distribution properties, and Knoop scratch lateral cracking thresholds of the chemically strengthened glass articles formed from Compositions 14-26

[0258]

[0259]

[0260] Table 4 (continued): Ion exchange conditions, stress distribution properties, and Knoop scratch lateral crack threshold of chemically strengthened glass articles formed from Compositions 14 - 26

[0261]

[0262]

[0263] In Table 4, the DOC is recorded as a fraction of the thickness and can be used to calculate the absolute value of the DOC in mm, as described above with respect to Table 2.

[0264] Generally speaking, Compositions 14 - 26 have different Al 2 O 3 , Li 2 O, and Na 2 O values compared to Compositions 1 - 13. In Compositions 14 - 26, the amount of B 2 O 3 is increased in increments of about 0.5 mol% from Composition 14 to Composition 26 in sequence. At the same time, from Composition 14 to Composition 26, the relative amounts of Al 2 O 3 and Na 2 O decrease in increments of about 0.15 mol% and 0.35 mol% respectively in sequence. These compositional changes reduce the average network connectivity of the glass - forming material while maintaining the maximum CT value exhibited by the chemically strengthened glass articles. In addition, the resulting chemically strengthened glass articles exhibit an increased Knoop scratch lateral crack threshold, as shown in Table 4. For example, the chemically strengthened glass articles formed from Compositions 16 - 20 exhibit a high Knoop scratch lateral crack threshold while still maintaining a deep DOC value (e.g., greater than 0.15t) and a relatively high surface CS value (e.g., greater than 700 MPa).

[0265] Example 3

[0266] Batch Composition 27 - 33 and form a glass article. Then the resulting glass article is fictitiously annealed to 10 11 Poisson temperature and then ion - exchanged according to Ion Exchange Condition A for different durations to form a chemically strengthened glass article. The resulting chemically strengthened glass article exhibits a stress distribution with the properties described herein, and the stress distribution as well as the Knoop scratch lateral crack threshold are measured. Table 5 includes the properties of Compositions 27 - 33 and the non - strengthened glass article. Table 6 shows the ion exchange conditions and properties of the chemically strengthened glass articles formed from Compositions 27 - 33.

[0267] Table 5: Properties of Compositions 27 - 33 and the Compositions and the Resulting Glass Articles

[0268]

[0269]

[0270] Table 5 (continued): Properties of Compositions 27 - 33 and the Compositions and the Resulting Glass Articles

[0271]

[0272]

[0273] Table 6: Ion Exchange Conditions, Stress Distribution Properties, and Knoop Scratch Lateral Cracking Thresholds of Chemically Strengthened Glass Articles Formed from Compositions 27 - 33

[0274]

[0275]

[0276] In Table 6, the DOC is recorded as a fraction of the thickness and can be used to calculate the absolute value of the DOC in mm, as described above with respect to Table 2.

[0277] Generally speaking, Compositions 27 - 33 have different Al 2 O 3 , Li 2 O, and Na 2 O values compared to Compositions 1 - 13. In Compositions 14 - 26, in turn, from Composition 27 to Composition 33, the amount of Li 2 O increases while the amount of Na 2 O decreases. Substituting Li 2 O for Na 2 O in the composition and subsequent ion exchange by immersion in a 100% NaNO 3 molten salt bath results in a chemically strengthened glass article having an increased maximum CT while maintaining a deep DOC that approaches and in at least one case achieves 0.2t.

[0278] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the scope or spirit of the invention. For example, various features can be combined in accordance with the following exemplary embodiments.

[0279] Embodiment 1, A glass article comprising a composition, the composition comprising:

[0280] SiO 2, the amount is about 60-80 mol%;

[0281] Al 2 O 3 , in an amount greater than or equal to about 13.5 mol %;

[0282] Li 2 O, in an amount of about 5-11 mol%;

[0283] P 2 O 5 , in an amount of about 1-5 mol%;

[0284] More than 0.9 mol% B 2 O 3 ;as well as

[0285] Na 2 O, the amount is about 0.5-12 mol%.

[0286] Embodiment 2, a glass product, comprising a composition, wherein the composition comprises:

[0287] SiO 2 , the amount is about 60-80 mol%;

[0288] Al 2 O 3 , in an amount greater than or equal to about 10 mol %;

[0289] Li 2 O, in an amount of about 4-11 mol%;

[0290] B 2 O 3 , in an amount of about 0.9-7.5 mol %;

[0291] B 2 O 3 , P 2 O 5 、SiO 2 and Al 2 O 3 A total amount of greater than or equal to about 80 mole %; and

[0292] Li 2 O and B 2 O 3 , P 2 O 5 、SiO 2 and Al 2 O 3 The ratio of the total amount is less than 0.074.

[0293] Embodiment 3, the glass product of embodiment 2, wherein SiO 2The amount is about 65 - 80 mol%.

[0294] Embodiment 4. A glass article such as that of Embodiment 2 or 3, further comprising: a non - zero amount of P 2 O 5 ; and K 2 O, the amount being less than 1.0 mol%.

[0295] Embodiment 5. A glass article such as that of any one of Embodiments 1 - 4, wherein the amount of B 2 O 3 is about 0.9 - 6.5 mol%.

[0296] Embodiment 6. A glass article such as that of any one of Embodiments 1 - 5, wherein the amount of Na 2 O is about 3 - 11 mol%.

[0297] Embodiment 7. A glass article such as that of any one of the foregoing embodiments, wherein the composition comprises Li 2 O in an amount of about 5 - 11 mol%.

[0298] Embodiment 8. A glass article such as that of any one of the foregoing embodiments, wherein the composition further comprises RO, where RO includes any one or more of MgO, CaO, SrO, BaO, and ZnO.

[0299] Embodiment 9. A glass article such as that of Embodiment 8, wherein the total amount of RO is at least one of the following: about 0.05 - 4 mol%, and about 0.05 - 2 mol%.

[0300] Embodiment 10. A glass article such as that of any one of the foregoing embodiments, wherein the composition is substantially free of K 2 O.

[0301] Embodiment 11. A glass article such as that of Embodiment 1 or any one of Embodiments 5 - 10, wherein the total amount of B 2 O 3 、P 2 O 5 、SiO 2 and Al 2 O 3 is greater than or equal to about 80 mol%.

[0302] Embodiment 12. A glass article such as that of any one of the foregoing embodiments, wherein, in mol%, the composition further comprises:

[0303] about 13.5 - 18 mol% Al 2 O 3 ; and

[0304] about 0.5 - 3 mol% ZnO.

[0305] Embodiment 13, a glass article according to any of the preceding embodiments, wherein Na 2 The amount of O is greater than that of Li 2 The amount of O.

[0306] Embodiment 14. The glass article of any of the preceding embodiments, wherein P 2 O 5 The amount is less than about 3 mol %.

[0307] Embodiment 15. The glass article of any of the preceding embodiments, wherein the composition further comprises SnO 2 .

[0308] Embodiment 16. The glass article of any of the preceding embodiments, wherein the composition further comprises a liquidus viscosity of less than or equal to about 300 kilopoise.

[0309] Embodiment 17. The glass article of any one of embodiments 1-16, wherein the composition further comprises a liquidus viscosity greater than about 300 kpoise.

[0310] Embodiment 18. The glass article of any of the preceding embodiments, wherein the composition further comprises less than about 1.5 mol% ZrO 2 .

[0311] Embodiment 19, a glass product, comprising a composition, wherein the composition comprises:

[0312] SiO 2 , the amount is about 60-80 mol%;

[0313] Al 2 O 3 , an amount greater than or equal to 10 mol%;

[0314] Li 2 O, in an amount of about 5-10 mol%;

[0315] P 2 O 5 , in an amount of about 1-5 mol%;

[0316] More than 0.9 mol% B 2 O 3 ;as well as

[0317] Na 2 O, the amount is about 0.5-12 mol%.

[0318] Embodiment 20, the glass article of embodiment 19, wherein the composition further comprises a total amount of about 12-20 mol% R 2 O.

[0319] Embodiment 21. A glass article according to any one of Embodiments 19 - 20, wherein B 2 O 3 is present in an amount of about 1 - 6.5 mol%.

[0320] Embodiment 22. A glass article according to any one of Embodiments 19 - 21, wherein Na 2 O is present in an amount of about 3 - 11 mol%.

[0321] Embodiment 23. A glass article according to any one of Embodiments 19 - 22, wherein Li 2 O is present in an amount of about 5 - 7 mol%.

[0322] Embodiment 24. A glass article according to any one of Embodiments 19 - 23, wherein the composition further comprises RO, where RO comprises any one or more of MgO, CaO, SrO, BaO, and ZnO.

[0323] Embodiment 25. A glass article according to Embodiment 24, wherein the total amount of RO is about 0.05 - 4 mol%.

[0324] Embodiment 26. A glass article according to any one of Embodiments 19 - 25, wherein the composition is substantially free of K 2 O and comprises less than about 1.5 mol% ZrO 2 .

[0325] Embodiment 27. A glass article according to any one of Embodiments 19 - 26, wherein the total amount of B 2 O 3 , P 2 O 5 , SiO 2 and Al 2 O 3 is greater than about 80 mol%.

[0326] Embodiment 28. A glass article according to any one of Embodiments 19 - 27, wherein the composition further comprises:

[0327] about 10 - 16 mol% Al 2 O 3 ; and

[0328] about 0.5 - 3 mol% ZnO.

[0329] Embodiment 29. A glass article according to any one of Embodiments 19 - 28, wherein the amount of Na 2 O is greater than the amount of Li 2 O.

[0330] Embodiment 30, a glass article as in any one of Embodiments 19 - 29, wherein P 2 O 5 is present in an amount less than about 3 mol%.

[0331] Embodiment 31, a glass article as in any one of Embodiments 19 - 30, wherein the composition further comprises SnO 2 .

[0332] Embodiment 32, a glass article as in any one of Embodiments 19 - 31, wherein the composition further comprises a liquidus viscosity less than or equal to about 300 kPoise.

[0333] Embodiment 33, a glass article as in any one of Embodiments 19 - 32, wherein the composition further comprises a liquidus viscosity greater than about 300 kPoise.

[0334] Embodiment 34, a chemically strengthened glass article comprising:

[0335] a first major surface and an opposing second major surface that define a thickness t of about 0.3 - 1.5 mm,

[0336] a composition comprising: Li 2 O, P 2 O 5 , greater than about 0.9 mol% B 2 O 3 , Al 2 O 3 in an amount greater than or equal to 13.5 mol%, and about 0.5 - 12 mol% Na 2 O,

[0337] a compressive stress (CS) layer extending from the first major surface to a compressive depth (DOC) greater than about 0.12t,

[0338] wherein the CS layer comprises a maximum stress greater than or equal to about 200 MPa, and

[0339] wherein the glass article comprises a Knoop lateral cracking scratch threshold greater than about 6 N, as measured on either the first major surface or the second major surface.

[0340] Embodiment 35, a chemically strengthened glass article comprising:

[0341] a first major surface and an opposing second major surface that define a thickness t of about 0.3 - 1.5 mm,

[0342] a composition comprising: SiO 2 in an amount of about 60 - 80 mol%, Al 2 O 3The amount of is greater than or equal to about 10 mol%, Li 2 The amount of O is about 4 - 11 mol%, B 2 O 3 The amount of is about 0.9 - 7.5 mol%, B 2 O 3 、P 2 O 5 、SiO 2 and Al 2 O 3 The total amount of and is greater than or equal to about 80 mol%, and Li 2 O and B 2 O 3 、P 2 O 5 、SiO 2 and Al 2 O 3 The ratio of the total amount of is less than 0.074;

[0343] A compressive stress (CS) layer extending from the first major surface to a compressive depth (DOC) greater than about 0.12t,

[0344] wherein the CS layer includes a maximum stress greater than or equal to about 200 MPa, and

[0345] wherein the glass article includes a Knoop lateral cracking scratch threshold greater than about 6 N, measured on either the first major surface or the second major surface.

[0346] Embodiment 36, a chemically strengthened glass article as in Embodiment 35, wherein the amount of SiO 2 is about 65 - 80 mol%.

[0347] Embodiment 37, a chemically strengthened glass article as in Embodiment 35 or 36, further comprising: a non-zero amount of P 2 O 5 ; and K 2 O, the amount being less than 1.0 mol%.

[0348] Embodiment 38, a chemically strengthened glass article as in any one of Embodiments 34 - 37, further comprising a metal oxide concentration that is non-zero and varies along a thickness range of about 0t to about 0.3t, wherein the metal oxide includes Na 2 O, K 2 O, Rb 2 O, and Cs 2 O, any one or more of them.

[0349] Embodiment 39. A chemically strengthened glass article as in any one of Embodiments 34-38, wherein the concentration of the metal oxide is non-zero and varies along the entire thickness.

[0350] Embodiment 40. A chemically strengthened glass article as in any one of Embodiments 34-39, wherein the metal oxide generates stress along a thickness range.

[0351] Embodiment 41. A chemically strengthened glass article as in any one of Embodiments 34-40, wherein the concentration of the metal oxide decreases from a first surface to a value at a point between the first surface and the second surface, and increases from this value to the second surface.

[0352] Embodiment 42. A chemically strengthened glass article as in any one of Embodiments 34-41, which further includes a maximum central tension greater than about 40 MPa.

[0353] Embodiment 43. A chemically strengthened glass article as in Embodiment 42, wherein the maximum CT is about 40-100 MPa.

[0354] Embodiment 44. A chemically strengthened glass article as in Embodiment 43, which further includes a Young's modulus less than 85 MPa.

[0355] Embodiment 45. A chemically strengthened glass article as in any one of Embodiments 34-44, wherein the article withstands a maximum surface impact force of about 400-851 N, as measured by a surface threshold failure impact force test.

[0356] Embodiment 46. A chemically strengthened glass article as in any one of Embodiments 34-45, wherein the article withstands an average edge impact force greater than about 200 N to about 500 N, as measured by an edge threshold failure impact force test.

[0357] Embodiment 47. A chemically strengthened glass article as in any one of Embodiments 34-46, wherein the article withstands an edge impact energy greater than about 0.43 J to about 1.3 J, as measured by an edge threshold failure impact force test.

[0358] Embodiment 48. An apparatus, comprising:

[0359] A housing having a front surface, a rear surface, and side surfaces;

[0360] Electronic components at least partially located within the housing;

[0361] A display located on the front surface of the housing or adjacent to the front surface of the housing; and

[0362] A cover article disposed on the display, wherein at least one of the cover article and at least a portion of the housing includes a chemically strengthened glass article according to any one of Embodiments 34-47.

[0363] Embodiment 49. A chemically strengthened glass article comprising:

[0364] A first major surface and a second major surface opposite the first surface, defining a thickness (t) of less than about 3 mm;

[0365] A composition comprising: Li 2 in an amount less than or equal to about 10 mol%, P 2 O 5 , greater than about 0.9 mol% B 2 O 3 , Al 2 O 3 in an amount greater than or equal to 10 mol%, and about 0.5-12 mol% Na 2 O; and

[0366] A stress distribution extending along the thickness,

[0367] wherein at least one point of the stress distribution between a thickness range of about 0t to up to 0.3t and at least one point of the stress distribution at a thickness greater than 0.7t includes a tangent having an absolute value of the slope greater than about 0.1 MPa / micron,

[0368] wherein the stress distribution includes a maximum CS, DOC, and a maximum CT of less than about 100 MPa, wherein the absolute value ratio of the maximum CT to the maximum CS is about 0.01 to about 0.2, and wherein the DOC is greater than or equal to about 0.1t.

[0369] Embodiment 50. A chemically strengthened glass article comprising:

[0370] A first major surface and a second major surface opposite the first surface, defining a thickness (t) of less than about 3 mm;

[0371] A composition comprising: SiO 2 in an amount of about 60-80 mol%, Al 2 O 3 in an amount greater than or equal to about 10 mol%, Li 2 O in an amount of about 4-11 mol%, B 2 O 3 in an amount of about 0.9-7.5 mol%, B 2 O 3 , P 2 O 5 , SiO2 and Al 2 O 3 in a total amount greater than or equal to about 80 mol%, and Li 2 O and B 2 O 3 , P 2 O 5 , SiO 2 and Al 2 O 3 in a ratio of the total amount less than 0.074; and

[0372] a stress distribution extending along the thickness,

[0373] wherein at least one point of the stress distribution between a thickness range of about 0t to up to 0.3t and at least one point of the stress distribution at a thickness greater than 0.7t includes a tangent having an absolute value of the slope greater than about 0.1 MPa / micron,

[0374] wherein the stress distribution includes a maximum CS, DOC, and a maximum CT less than about 100 MPa, wherein the absolute value ratio of the maximum CT to the maximum CS is about 0.01 to about 0.2, and wherein the DOC is greater than or equal to about 0.1t.

[0375] Embodiment 51, a chemically strengthened glass article as in Embodiment 50, wherein the amount of SiO 2 is about 65 - 80 mol%.

[0376] Embodiment 52, a chemically strengthened glass article as in Embodiment 50 or 51, further comprising: a non - zero amount of P 2 O 5 ; and K 2 O, in an amount less than 1.0 mol%.

[0377] Embodiment 53, a chemically strengthened glass article as in any one of Embodiments 49 - 52, further comprising a surface CS greater than or equal to about 300 MPa.

[0378] Embodiment 54, a chemically strengthened glass article as in any one of Embodiments 49 - 53, further comprising a Young's modulus less than 85 MPa.

[0379] Embodiment 55, a chemically strengthened glass article as in any one of Embodiments 49 - 54, further comprising a surface CS greater than or equal to about 200 MPa, and a maximum chemical depth greater than or equal to about 0.4t.

[0380] Embodiment 56. A chemically strengthened glass article as in any one of Embodiments 49-55, further comprising a CS layer extending from the first surface to the DOC, wherein the DOC is greater than or equal to about 0.1t.

[0381] Embodiment 57. A chemically strengthened glass article as in any one of Embodiments 49-56, further comprising a CT region, wherein the CT region comprises a metal oxide concentration gradient, and wherein the metal oxide comprises Na 2 O, K 2 O, Rb 2 O, and Cs 2 O, any one or more thereof.

[0382] Embodiment 58. A chemically strengthened glass article as in any one of Embodiments 49-57, further comprising a ratio of maximum CT to surface CS of about 0.01 to 0.2.

[0383] Embodiment 59. A chemically strengthened glass article as in any one of Embodiments 49-58, wherein the glass article comprises a Knoop lateral cracking scratch threshold greater than about 6N, which is measured on any one of the first major surface and the second major surface.

[0384] Embodiment 60. A chemically strengthened glass article as in any one of Embodiments 49-59, wherein the article withstands a maximum surface impact force of about 400 - 851N, which is measured by a surface threshold failure impact force test.

[0385] Embodiment 61. A chemically strengthened glass article as in any one of Embodiments 49-60, wherein the article withstands an average edge impact force greater than about 200N to about 500N, which is measured by an edge threshold failure impact force test.

[0386] Embodiment 62. A chemically strengthened glass article as in any one of Embodiments 49-61, wherein the article withstands an edge impact energy greater than about 0.43J to about 1.3J, which is measured by an edge threshold failure impact force test.

[0387] Embodiment 63. A consumer electronic product, comprising:

[0388] A housing having a front surface, a back surface, and side surfaces;

[0389] Electronic components at least partially located within the housing, the electronic components at least including a controller, a memory, and a display, the display being provided at or adjacent to the front surface of the housing; and

[0390] A cover substrate disposed on the display,

[0391] Wherein, at least one part of a portion of the outer shell or the covering substrate includes the tempered glass article of any one of Embodiments 49-62.

[0392] Embodiment 64, a chemically strengthened glass article, comprising:

[0393] A first major surface and an opposite second major surface, which define a thickness t of about 0.3-1.5 mm,

[0394] A composition of alkaline aluminosilicate, which contains Li 2 O and B 2 O 3 ;

[0395] A compressive stress (CS) layer extending from the first major surface to a compressive depth (DOC) greater than about 0.12t,

[0396] Wherein, the CS layer includes a maximum stress greater than or equal to about 200 MPa, and

[0397] Wherein, the glass article includes a Knoop lateral cracking scratch threshold greater than about 6 N, which is measured on any one of the first major surface and the second major surface, and

[0398] Wherein, at least one of the following:

[0399] (i) The article withstands a maximum surface impact force of about 400-851 N, which is measured by the surface threshold failure impact force test;

[0400] (ii) The article withstands an average edge impact force greater than about 200 N to about 500 N, which is measured by the edge threshold failure impact force test; and

[0401] (iii) The article withstands an edge impact energy greater than about 0.43 J to about 1.3 J, which is measured by the edge threshold failure impact force test.

[0402] Embodiment 65, a chemically strengthened glass article as in Embodiment 64, wherein the composition further includes the following components: SiO 2 in an amount of about 60-80 mol%, Al 2 O 3 in an amount greater than or equal to about 10 mol%, Li 2 O in an amount of about 4-11 mol%, B 2 O 3 in an amount of about 0.9-7.5 mol%, B 2 O 3 、P 2 O 5 、SiO2 and Al 2 O 3 the total amount of, and Li 2 O and B 2 O 3 , P 2 O 5 、SiO 2 and Al 2 O 3 is less than 0.074.

[0403] Embodiment 66, a chemically strengthened glass article as in Embodiment 64 or 65, further comprising: a non-zero amount of P 2 O 5 ; and K 2 O, in an amount less than 1.0 mol%.

[0404] Embodiment 67, a chemically strengthened glass article as in any one of Embodiments 64-66, further comprising a metal oxide concentration that is non-zero and varies along a thickness range of from about 0t to about 0.3t, wherein the metal oxide includes Na 2 O, K 2 O, Rb 2 O, and Cs 2 O, or any combination thereof.

[0405] Embodiment 68, a chemically strengthened glass article as in any one of Embodiments 64-67, wherein the concentration of the metal oxide is non-zero and varies throughout the thickness.

[0406] Embodiment 69, a chemically strengthened glass article as in any one of Embodiments 64-68, wherein the metal oxide generates stress along the thickness range.

[0407] Embodiment 70, a chemically strengthened glass article as in any one of Embodiments 64-69, wherein the concentration of the metal oxide decreases from a first surface to a value at a point between the first and second surfaces and then increases to the second surface.

[0408] Embodiment 71, a chemically strengthened glass article as in any one of Embodiments 64-70, further comprising a maximum center tension of from about 40-100 MPa.

[0409] Embodiment 72, a chemically strengthened glass article as in Embodiment 71, further comprising a Young's modulus of less than 85 MPa.

[0410] Embodiment 73, a chemically strengthened glass article as in any one of Embodiments 64-72, wherein SiO 2The amount is about 65-80 mol%.

[0411] Embodiment 74, an apparatus comprising:

[0412] a housing having a front surface, a rear surface, and side surfaces;

[0413] an electronic component at least partially located within the housing;

[0414] a display located on or adjacent to the front surface of the housing; and

[0415] a cover article disposed on the display, wherein at least one of the cover article and at least a portion of the housing comprises a chemically strengthened glass article according to any one of Embodiments 64-73.

Claims

1. A chemically strengthened glass article, which comprises: a first major surface and an opposite second major surface, which define a thickness t of 0.3 mm to 1.5 mm, an alkaline aluminosilicate composition, which comprises: Li 2 O; B 2 O 3 ; Al 2 O 3 , the amount is greater than or equal to 13 mol%; and A non-zero amount of P 2 O 5 ; and a compressive stress (CS) layer extending from the first major surface to a compressive depth (DOC) greater than 0.12t, wherein the CS layer comprises a maximum stress of 200 MPa or greater, and wherein the glass article comprises a Knoop lateral cracking scratch threshold greater than 6 N, which is measured on either the first major surface or the second major surface, and wherein at least one of the following: (i) the article withstands a maximum surface impact force of 400 N to 851 N, which is measured by a surface threshold failure impact force test; (ii) the article withstands an average edge impact force greater than 200 N to 500 N, which is measured by an edge threshold failure impact force test; and (iii) the article withstands an edge impact energy greater than 0.43 J to 1.3 J, which is measured by an edge threshold failure impact force test.

2. The chemically strengthened glass article according to claim 1, wherein, The composition further comprises the following components: SiO 2 , with a content of 60 mol% to 80 mol%; Li 2 O, with a content of 4 mol% to 11 mol%; the total amount of B 2 O 3 , P 2 O 5 , SiO 2 and Al 2 O 3 is 80 mol% or higher; and the ratio of Li 2 O to the total amount of B 2 O 3 , P 2 O 5 , SiO 2 and Al 2 O 3 is less than 0.

074.

3. The chemically strengthened glass article according to claim 1 or 2, further comprising K 2 O, in an amount less than 1.0 mol%.

4. The chemically strengthened glass article according to claim 1 or 2, which further comprises a metal oxide concentration, the metal oxide concentration being non-zero and varying along a thickness range of 0t to 0.3t, wherein, The metal oxide includes Na 2 O, K 2 O, Rb 2 O, and Cs 2 O, any one or more thereof.

5. The chemically strengthened glass article according to claim 4, wherein, the metal oxide concentration is non-zero and varies throughout the thickness.

6. The chemically strengthened glass article according to claim 4, wherein, the metal oxide generates stress along the thickness range.

7. The chemically strengthened glass article according to claim 4, wherein, the metal oxide concentration decreases from the first major surface to a value at a point between the first major surface and the second major surface, and increases from this value to the second major surface.

8. The chemically strengthened glass article according to claim 4, which further comprises a maximum central tension of 40 MPa to 100 MPa.

9. The chemically strengthened glass article according to claim 8, which further comprises a Young's modulus of less than 85 MPa.

10. The chemically strengthened glass article according to claim 1 or 2, wherein, SiO 2 is in an amount of 65 mol% to 80 mol%.

11. An apparatus, which comprises: a housing having a front surface, a rear surface and side surfaces; electronic components at least partially located within the housing; a display located on the front surface of the housing or adjacent to the front surface of the housing; and a cover article disposed on the display, wherein at least one of the cover article and at least a portion of the housing comprises the chemically strengthened glass article according to claim 1 or 2.

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