Fusion-formable glass with high fracture toughness

Abstract

The glass composition includes 56 mol% to 70 mol% SiO2, 12 mol% to 20 mol% Al2O3, 0 mol% to 4 mol% P2O5, 0 mol% to 8 mol% B2O3, 6 mol% to 12 mol% Li2O, 4 mol% to 12 mol% Na2O, 0.4 mol% to 3 mol% K2O, 2 mol% to 6 mol% MgO, 0.25 mol% to 6 mol% CaO, 0 mol% to 3 mol% SrO, 0 mol% to 5 mol% ZnO, and 0 mol% to 1 mol% ZrO2. The glass composition has a viscosity of 0.75 MPa m 0.5 or greater and a Young's modulus of 80 GPa or greater. The glass composition can be chemically strengthened. The glass composition can be used in glass-based articles or consumer electronic products.

Description

Priority

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 277,676, filed November 10, 2021, the contents of which are relied upon and incorporated herein by reference in their entirety. [Technical field]

[0002] This disclosure relates generally to glass compositions suitable for use in cover glass for electronic devices. More particularly, this disclosure relates to ion-exchangeable glasses that can be formed into cover glass for electronic devices. [Background technology]

[0003] The portable nature of portable devices such as smartphones, tablets, portable media players, personal computers, and cameras makes these devices particularly susceptible to situations where they are accidentally dropped onto a hard surface, such as the ground. These devices typically incorporate a cover glass that can be damaged upon impact with a hard surface. In many of these devices, the cover glass acts as a cover for the display and may provide touch functionality, and thus, use of the device is adversely affected when the cover glass is damaged.

[0004] There are two primary failure modes for cover glass when the associated portable device is dropped onto a hard surface. One of these modes is bending failure, which occurs due to bending of the glass when the device is subjected to dynamic loads from impact with the hard surface. The other mode is sharp contact failure, which occurs due to the introduction of damage into the glass surface. When glass impacts with rough hard surfaces such as asphalt, granite, etc., sharp indentations can be created on the glass surface. These indentations become breakage sites in the glass surface from which cracks can initiate and propagate.

[0005] Glass can be made more resistant to bending fracture by ion-exchange techniques, which involve inducing compressive stresses in the glass surface. However, ion-exchanged glass is still vulnerable to dynamic sharp contact due to high stress concentrations caused by localized indentation of the glass by the sharp contact.

[0006] Glass manufacturers and manufacturers of handheld devices have continually worked to improve the resistance of handheld devices to breakage due to sharp contact. Solutions range from coatings on the cover glass to bezels that prevent the cover glass from directly impacting a hard surface when the device is dropped onto it. However, due to constraints of aesthetic and functional requirements, it is very difficult to completely prevent the cover glass from impacting a hard surface.

[0007] It is also desirable for portable devices to be as thin as possible. Thus, in addition to strength, it is also desirable to make the glass to be used as a cover glass in a portable device as thin as possible. Therefore, in addition to enhancing the strength of the cover glass, it is also desirable for the glass to have mechanical properties that allow it to be formed by processes that allow the production of thin glass-based articles, such as thin glass sheets. Summary of the Invention [Problem to be solved by the invention]

[0008] Thus, there is a need for glasses that can be strengthened, such as by ion exchange, and that have mechanical properties that allow them to be formed into thin glass-based articles. [Means for solving the problem]

[0009] According to embodiment (1), a glass is provided, the glass comprising 56 mol% to 70 mol% SiO2, 12 mol% to 20 mol% Al2O3, 0 mol% to 4 mol% P2O5, 0 mol% to 8 mol% B2O3, 6 mol% to 12 mol% Li2O, 4 mol% to 12 mol% Na2O, 0.4 mol% to 3 mol% K2O, 2 mol% to 6 mol% MgO, 0.25 mol% to 6 mol% CaO, 0 mol% to 3 mol% SrO, 0 mol% to 5 mol% ZnO, and 0 mol% to 1 mol% ZrO2.

[0010] According to an embodiment (2), there is provided the glass of embodiment (1), comprising 60 mol % or more and 64 mol % or less of SiO2.

[0011] According to an embodiment (3), there is provided the glass of any of the previous embodiments, comprising 14 mol % or more and 16 mol % or less of Al2O3.

[0012] According to an embodiment (4), there is provided the glass of any of the previous embodiments, comprising 8 mol % or more and 9 mol % or less of Li2O.

[0013] According to an embodiment (5), there is provided the glass of any of the previous embodiments, comprising 7 mol % or more and 12 mol % or less Na2O.

[0014] According to an embodiment (6), there is provided the glass of any of the previous embodiments, comprising 7 mol % or more and 11 mol % or less Na2O.

[0015] According to an embodiment (7), there is provided the glass of any of the previous embodiments, comprising 0.4 mol % or more and 1 mol % or less of K2O.

[0016] According to an embodiment (8), there is provided the glass of any of the previous embodiments, comprising 2.5 mol % or more and 4 mol % or less of MgO.

[0017] According to an embodiment (9), there is provided the glass of any of the previous embodiments, comprising 1 mol % or more and 6 mol % or less of CaO.

[0018] According to an embodiment (10), there is provided the glass of any of the previous embodiments, comprising 1.5 mol % or more and 6 mol % or less of CaO.

[0019] According to an embodiment (11), there is provided the glass of any of the previous embodiments, comprising 0.05 mol % or more and 0.5 mol % or less of SnO2.

[0020] According to an embodiment (12), there is provided the glass of any of the previous embodiments, comprising from 0 mol % to 0.2 mol % of TiO2.

[0021] According to an embodiment (13), there is provided the glass of any of the previous embodiments, wherein the glass is substantially free of TiO2.

[0022] According to an embodiment (14), there is provided the glass of any of the previous embodiments, wherein the glass is substantially free of P2O5.

[0023] According to an embodiment (15), there is provided the glass of any of the previous embodiments, comprising greater than or equal to 0 mol % and less than or equal to 5 mol % B2O3.

[0024] According to an embodiment (16), there is provided the glass of any of the previous embodiments, wherein the glass is substantially free of B2O3.

[0025] According to an embodiment (17), there is provided the glass of any of the previous embodiments, comprising from 0 mol % to 2 mol % SrO.

[0026] According to an embodiment (18), there is provided the glass of any of the previous embodiments, wherein the glass is substantially free of SrO.

[0027] According to an aspect (19), there is provided the glass of any of the previous aspects, wherein the glass is substantially free of ZnO.

[0028] According to an embodiment (20), there is provided the glass of any of the previous embodiments, wherein the glass is substantially free of ZrO2.

[0029] According to an aspect (21), there is provided the glass of any of the previous aspects, wherein the glass is substantially free of Fe2O3.

[0030] According to an embodiment (22), there is provided the glass of any of the previous embodiments, wherein the glass is substantially free of Ta2O5, HfO2, La2O3, and Y2O3.

[0031] According to an embodiment (23), there is provided the glass of any of the previous embodiments, wherein the glass has a liquidus viscosity of 50 kP or greater.

[0032] According to aspect (24), the glass has a viscosity of 0.75 MPa m 0.5 Above 0.9MPa·M 0.5 Fracture toughness K IC The glass of any of the previous aspects is provided, having

[0033] According to an aspect (25), there is provided the glass of any of the previous aspects, wherein the glass has a Young's modulus of 80 GPa or more and 90 GPa or less.

[0034] According to aspect (26), there is provided a method comprising ion exchanging a glass-based substrate in a molten salt bath to form a glass-based article comprising a compressive stress layer extending from a surface of the glass-based article to a compression depth, the glass-based article comprising a central tension region, and the glass-based substrate made from the glass of any of the previous aspects.

[0035] According to an embodiment (27), there is provided the method of embodiment (26), wherein the molten salt bath comprises NaNO.

[0036] According to embodiment (28), there is provided the method of any of embodiments (26) through the immediately preceding embodiment, wherein the molten salt bath comprises KNO.

[0037] According to embodiment (29), there is provided the method of any of embodiments (26) to the immediately preceding embodiment, wherein the molten salt bath comprises NaNO3 and KNO3.

[0038] According to an embodiment (30), there is provided the method of any of the embodiments (26) through the immediately preceding embodiment, wherein the molten salt bath is at a temperature of from 400° C. or more to 550° C. or less.

[0039] According to embodiment (31), there is provided the method of any of embodiments (26) to the immediately preceding embodiment, wherein the ion exchange is for a period of from 0.5 hours or more to 48 hours or less.

[0040] According to embodiment (32), there is provided the method of any of embodiments (26) through the immediately preceding embodiment, further comprising ion exchanging the glass-based article in a second molten salt bath.

[0041] According to an embodiment (33), there is provided the method of embodiment (32), wherein the second molten salt bath comprises KNO.

[0042] According to embodiment (34), there is provided the method of any of embodiments (32) to the immediately preceding embodiment, wherein the ion exchange in the second molten salt bath is for a period of from 0.5 hours or more to 48 hours or less.

[0043] According to embodiment (35), a glass-based article is provided having a compressive stress layer extending from the surface to a compression depth of the glass-based article, a central tension region, and a composition at the center of the glass-based article that includes 56 mol% to 70 mol% SiO2, 12 mol% to 20 mol% Al2O3, 0 mol% to 4 mol% P2O5, 0 mol% to 8 mol% B2O3, 6 mol% to 12 mol% Li2O, 4 mol% to 12 mol% Na2O, 0.4 mol% to 3 mol% K2O, 2 mol% to 6 mol% MgO, 0.25 mol% to 6 mol% CaO, 0 mol% to 3 mol% SrO, 0 mol% to 5 mol% ZnO, and 0 mol% to 1 mol% ZrO2.

[0044] According to an embodiment (36), there is provided the glass-based article of embodiment (35), wherein the compressive stress layer has a compressive stress of 400 MPa or more and 2000 MPa or less.

[0045] According to embodiment (37), there is provided the glass-based article of any of embodiments (35) through the immediately preceding embodiment, wherein the central tension zone has a maximum central tension of from 30 MPa or more to 180 MPa or less.

[0046] According to embodiment (38), there is provided the glass-based article of any of embodiments (35) to the immediately preceding embodiment, wherein the compression depth is from 0.15t to 0.25t, inclusive, where t is the thickness of the glass-based article.

[0047] According to embodiment (39), there is provided the glass-based article of any of embodiments (35) through the immediately preceding embodiment, wherein the compressive stress layer has a compressive stress spike extending from a surface of the glass-based article to a compressive stress spike depth, the compressive stress spike depth being from 3 μm or more to 15 μm or less.

[0048] According to embodiment (40), there is provided the glass-based article of any of embodiments (35) to the immediately preceding embodiment, wherein the glass-based article has a thickness, t, of 0.2 mm or more and 2 mm or less.

[0049] According to embodiment (41), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 60 mol % or more and 64 mol % or less of SiO2.

[0050] According to embodiment (42), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 14 mol% or more and 16 mol% or less Al2O3.

[0051] According to embodiment (43), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 8 mol % or more and 9 mol % or less LiO.

[0052] According to embodiment (44), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 7 mol % or more and 12 mol % or less Na2O.

[0053] According to embodiment (45), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 7 mol% or more and 11 mol% or less Na2O.

[0054] According to embodiment (46), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 0.4 mol % or more and 1 mol % or less of KO.

[0055] According to embodiment (47), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 2.5 mol % or more and 4 mol % or less MgO.

[0056] According to embodiment (48), there is provided the glass of any of embodiments (35) through the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 1.5 mol % or more and 6 mol % or less CaO.

[0057] According to embodiment (49), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 1 mol % or more and 6 mol % or less CaO.

[0058] According to embodiment (50), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises 0.05 mol % or more and 0.5 mol % or less SnO2.

[0059] According to embodiment (51), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises greater than or equal to 0 mol % and less than or equal to 0.2 mol % TiO2.

[0060] According to embodiment (52), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article is substantially free of TiO2.

[0061] According to embodiment (53), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article is substantially free of P2O5.

[0062] According to embodiment (54), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises greater than or equal to 0 mol % and less than or equal to 5 mol % B2O3.

[0063] According to embodiment (55), there is provided the glass of any of embodiments (35) through the immediately preceding embodiment, wherein the composition at the center of the glass-based article is substantially free of B2O3.

[0064] According to embodiment (56), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article comprises greater than or equal to 0 mol % and less than or equal to 2 mol % SrO.

[0065] According to embodiment (57), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article is substantially free of SrO.

[0066] According to embodiment (58), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article is substantially free of ZnO.

[0067] According to embodiment (59), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article is substantially free of ZrO2.

[0068] According to embodiment (60), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article is substantially free of Fe2O3.

[0069] According to embodiment (61), there is provided the glass of any of embodiments (35) to the immediately preceding embodiment, wherein the composition at the center of the glass-based article is substantially free of Ta2O5, HfO2, La2O3, and Y2O3.

[0070] According to embodiment (62), there is provided the glass of any of embodiments (35) through the immediately preceding embodiment, wherein the glass having the same composition and microstructure as the composition at the center of the glass-based article has a liquidus viscosity of 50 kP or greater.

[0071] According to embodiment (63), a glass having the same composition and microstructure as the composition at the center of the glass-based article is melt-melted at 0.75 MPa m 0.5 Above 0.9MPa·M 0.5 Fracture toughness K IC The glass-based article of any of embodiment (35) to the immediately preceding embodiment is provided, having

[0072] According to embodiment (64), there is provided the glass-based article of any of embodiments (35) to the immediately preceding embodiment, wherein the glass having the same composition and microstructure as the composition at the center of the glass-based article has a Young's modulus of 80 GPa or more and 90 GPa or less.

[0073] According to aspect (65), there is provided a consumer electronics product comprising: a housing having a front, a back, and a side; electrical components disposed at least partially within the housing, the electrical components including at least a controller, a memory, and a display disposed at or adjacent to the front of the housing; and a cover substrate disposed over the display, at least a portion of at least one of the housing and the cover substrate being made from the glass-based article of any of aspects (35) through the immediately preceding aspect.

[0074] Additional features and advantages are set forth in the following detailed description, and in part will be readily apparent to those skilled in the art from that description, or will be learned by practicing the embodiments described herein, including the following detailed description, the claims, and the accompanying drawings.

[0075] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. [Brief description of the drawings]

[0076] [Figure 1] 1 is a schematic diagram of a cross section of a glass-based article having a compressive stress region according to embodiments described and disclosed herein; [Diagram 2] Schematic diagram of the specimen and its cross section used in the double cantilever beam (DCB) procedure for determining the fracture toughness KIC [Figure 3A] FIG. 1 is a plan view of an example electronic device incorporating any of the glass-based articles disclosed herein. [Figure 3B] FIG. 3B is a perspective view of the example electronic device of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0077] Reference will now be made in detail to lithium aluminosilicate glasses, according to various embodiments. Lithium aluminosilicate glasses have good ion exchangeability, and chemical strengthening processes have been used to achieve high strength and toughness properties in lithium aluminosilicate glasses. Lithium aluminosilicate glasses are highly ion-exchanged glasses with high glass quality. Substitution of Al2O3 in the silicate glass network increases the interdiffusivity of monovalent cations during ion exchange. Chemical strengthening in a molten salt bath (e.g., KNO3 or NaNO3) can result in glasses with high strength, high toughness, and high resistance to indentation crack formation. The stress profile achieved by chemical strengthening can have a variety of shapes that improve the drop performance, strength, toughness, and other attributes of glass-based articles.

[0078] Therefore, lithium aluminosilicate glasses with good physical properties, chemical durability, and ion exchangeability have been attracting attention for use as cover glasses. Specifically, lithium-containing aluminosilicate glasses with higher fracture toughness and higher Young's modulus are provided herein. By different ion exchange processes, larger central tension (CT), depth of compression (DOC), and high compressive stress (CS) can be achieved. However, the addition of lithium into aluminosilicate glasses can reduce the melting point, softening point, or liquidus viscosity of the glasses.

[0079] In the embodiments of the glass compositions described herein, concentrations of components (e.g., SiO2, Al2O3, Li2O, etc.) are given in mole percent (mol%) on an oxide basis unless otherwise specified. The components of the alkali aluminosilicate glass compositions according to the embodiments are described individually below. It should be understood that any of the various recited ranges of a component may be individually combined with any of the various recited ranges of any other component. As used herein, a trailing zero in a number is intended to represent a significant digit in that number. For example, "1.0" has two significant digits, and "1.00" has three significant digits.

[0080] As used herein, "glass substrate" refers to a piece of glass that has not been ion-exchanged. Similarly, "glass article" refers to a piece of glass that has been ion-exchanged and is formed by subjecting a glass substrate to an ion-exchange process. "Glass-based substrate" and "glass-based article" are defined accordingly and include glass substrates and glass articles, as well as substrates and articles made wholly or partially from glass, such as glass substrates and glass articles with surface coatings. Glass substrates and glass articles are sometimes referred to broadly and for convenience herein, although descriptions of glass substrates and glass articles should be understood to apply equally to glass-based substrates and glass-based articles.

[0081] High fracture toughness (K ICDisclosed herein is a lithium aluminosilicate glass composition containing MgO and CaO that exhibits a Young's modulus of at least 0.75 MPa m 0.5 K IC The glass composition is characterized by a fracture toughness value. In embodiments, the glass composition is characterized by a Young's modulus of at least 80 GPa. These properties are achieved, at least in part, by the inclusion of MgO, CaO, and Al2O3 in the glass.

[0082] While scratch performance is desirable, drop performance is a key attribute for glass-based articles incorporated into portable electronic devices. Fracture toughness and stress at depth are important for improving rough surface drop performance. For this reason, maximizing the amount of stress that can be provided to the glass before the frangibility limit is reached will increase stress at depth and rough surface drop performance. Fracture toughness is known to control the frangibility limit, and increasing fracture toughness increases the frangibility limit. The glass compositions disclosed herein have high fracture toughness and can achieve high compressive stress levels while remaining non-brittle. These features of the glass compositions allow for the development of improved stress profiles designed to address specific fracture modes. This capability allows ion-exchanged glass-based articles made from the glass compositions described herein to be customized with different stress profiles to address specific fracture modes of interest.

[0083] Glass compositions with high fracture toughness and Young's modulus are particularly suitable for forming chemically strengthened glass-based articles due to their ability to store large amounts of strain energy imparted by chemical strengthening without becoming brittle. The stored strain energy (Σ0) of commercial cover glasses and portable device housings is controlled to achieve the desired fracture resistance while avoiding the release of small particles upon fracture. The size (x) of the fragments that may form upon fracture is determined by the following formula:

[0084]

number

[0085] The fracture toughness (K IC ) and the maximum central tension (CT) of the glass-based article, where t is the thickness of the glass-based article, v is the Poisson's ratio of the glass utilized to form the chemically strengthened glass-based article, and DOC is the compression depth of the glass-based article. The above equation indicates that glass compositions with higher fracture toughness will produce chemically strengthened glass-based articles with reduced size of small particles expelled.

[0086] The number of fragments that are generated when a glass-based article breaks is calculated using the following formula:

[0087]

number

[0088] where E is the Young's modulus of the glass utilized to form the glass-based article, σ is the stress as a function of depth, z=0.5t-DOC, such that -z to z defines the central tension zone of the glass-based article. As shown by the stored strain energy equation above, glass compositions having higher Young's modulus values ​​have lower stored strain energy for any given stress profile, reducing the number of fragments produced when a glass-based article formed from that glass composition is fractured. Considering the fragment size equation and the stored strain energy equation together, it is apparent that glass compositions having high fracture toughness in combination with a high Young's modulus can produce glass-based articles with high maximum central tension while avoiding spallation.

[0089] The compositions described herein are selected to achieve high fracture toughness and Young's modulus values ​​while maintaining a desired degree of manufacturability. The compositions include high amounts of Al2O3 and Li2O to produce the desired fracture toughness while maintaining compatibility with desired manufacturing limitations. The drop performance of ion-exchanged glass-based articles formed from the glass compositions described herein is improved by increasing the amount of compressive stress imparted to the glass article. The glass compositions described herein provide improved ion exchange performance as evidenced by increased center tensile capacity and increased ion exchange rates.

[0090] In the glass compositions described herein, SiO2 is the most abundant component, and thus SiO2 is the main component of the glass network formed from the glass composition. Pure SiO2 has a relatively low CTE. However, the melting point of pure SiO2 is high. Thus, if the concentration of SiO2 in the glass composition is too high, the formability of the glass composition will be reduced because the higher concentration of SiO2 increases the difficulty of melting the glass, which in turn adversely affects the formability of the glass. In addition, if the glass composition contains too much SiO2, the glass's ability to generate compressive stress through ion exchange will be reduced. If the concentration of SiO2 in the glass composition is too low, the chemical durability of the glass may be reduced, and the glass will be susceptible to surface damage during post-molding processing. In embodiments, the glass composition generally comprises SiO2 in an amount of from 56 mol% to 70 mol%, e.g., from 57 mol% to 69 mol%, from 58 mol% to 68 mol%, from 59 mol% to 67 mol%, from 60 mol% to 66 mol%, from 61 mol% to 65 mol%, from 62 mol% to 64 mol%, and all ranges and subranges therebetween. In preferred embodiments, the glass composition comprises SiO2 in an amount of from 60 mol% to 64 mol%.

[0091] The glass composition includes Al2O3. Al2O3 may act as a glass network former, similar to SiO2. If the amount of Al2O3 is too high, Al2O3 may increase the liquidus viscosity of a glass melt formed from the glass composition and reduce the formability of the glass composition due to tetrahedral coordination. However, when the concentration of Al2O3 is balanced relative to the concentration of SiO2 and the concentration of alkali oxides in the glass composition, Al2O3 can reduce the liquidus temperature of the glass melt, thereby improving the liquidus viscosity and improving the compatibility of the glass composition with certain forming processes. Increasing the content of Al2O3 relative to the total content of alkali and alkaline earth oxides in the glass composition generally improves the durability of the glass. When the concentration of alkali oxides (R2O) approaches or exceeds the amount of Al2O3 in the glass composition, nearly all or all of the aluminum in the glass is present in a tetrahedral coordination state, and the alkali ions act as charge compensators. This charge balance increases the diffusivity of alkali ions and the rate of ion exchange. The inclusion of Al2O3 in the glass composition can provide high fracture toughness values, as described herein. In an embodiment, the glass composition includes Al2O3 in a concentration of from 12 mol% to 20 mol%, e.g., from 13 mol% to 19 mol%, from 14 mol% to 18 mol%, from 15 mol% to 17 mol%, from 12 mol% to 16 mol%, and all ranges and subranges therebetween. In a preferred embodiment, the glass composition includes Al2O3 in an amount of from 14 mol% to 16 mol%.

[0092] The glass composition includes Li2O. The inclusion of Li2O in the glass composition allows for better control of the ion exchange process and further reduces the softening point, liquidus temperature, and melting temperature of the glass, thereby enhancing the manufacturability of the glass. The presence of Li2O in the glass composition can also produce a stress profile having a parabolic shape. Li2O in the glass composition also enables the high fracture toughness values ​​described herein. If the glass composition contains too much Li2O, the thermal expansion coefficient of the glass increases and the chemical durability decreases. If the glass composition contains insufficient Li2O, the ability of the glass to be ion exchanged may be undesirably reduced and the desired stress profile may not be achieved. In an embodiment, the glass composition includes Li2O in an amount of 6 mol% to 12 mol%, e.g., 7 mol% to 11 mol%, 8 mol% to 10 mol%, 8 mol% to 9 mol%, and all ranges and subranges therebetween. In a preferred embodiment, the glass composition includes Li2O in an amount of 8 mol% to 9 mol%.

[0093] The glass compositions described herein include Na2O. Na2O aids in the ion-exchangeability of the glass composition, improving its formability, and therefore its manufacturability. However, adding too much Na2O to the glass composition may result in too low a CTE. Additionally, including too much Na2O in the glass relative to the amount of Li2O may reduce the glass's ability to achieve a large compression depth when ion-exchanged. In embodiments, the glass composition includes Na2O in an amount of 4 mol% to 12 mol%, e.g., 5 mol% to 11 mol%, 6 mol% to 10 mol%, 7 mol% to 9 mol%, 7 mol% to 8 mol%, and all ranges and subranges therebetween. In preferred embodiments, the glass composition includes Na2O in an amount of 7 mol% to 12 mol%, or even 7 mol% to 11 mol%.

[0094] The glass compositions described herein include K2O. The inclusion of K2O in the glass composition increases potassium diffusivity in the glass, resulting in a deeper compressive stress spike depth (DOL). SP ) can be achieved in shorter ion-exchange times. If the composition contains too much KO, the amount of compressive stress imparted during the ion-exchange process can be reduced. In embodiments, the glass composition contains KO in an amount of from 0.4 mol % to 3 mol %, e.g., from 0.5 mol % to 2.5 mol %, from 1.0 mol % to 2 mol %, from 1 mol % to 1.5 mol %, and all ranges and subranges therebetween. In preferred embodiments, the glass composition contains KO in an amount of from 0.4 mol % to 1 mol %.

[0095] The glass compositions described herein include MgO. MgO may reduce the liquidus viscosity of the glass and improve melting behavior, which improves the formability and manufacturability of the glass. The inclusion of MgO in the glass composition may also improve the strain point and Young's modulus of the glass composition. However, adding too much MgO to the glass composition may result in a liquidus viscosity that is too low to be compatible with desired forming techniques. Adding too much MgO may increase the density and CTE of the glass composition to undesirable levels and may reduce the mobility of alkali ions in the glass, reducing the effectiveness of ion exchange processes. The inclusion of MgO in the glass composition helps achieve the high fracture toughness values ​​described herein due to the strong electric field strength of MgO. In an embodiment, the glass composition includes MgO in an amount of from 2 mol% to 6 mol%, e.g., from 3 mol% to 5 mol%, from 2 mol% to 4 mol%, from 2.5 mol% to 4 mol%, and all ranges and subranges therebetween. In a preferred embodiment, the glass composition includes MgO in an amount of ≧2.5 mol % to ≦4 mol %.

[0096] The glass compositions described herein include CaO. The inclusion of CaO reduces the liquidus viscosity of the glass, which may improve formability, strain point, and Young's modulus. However, if too much CaO is added to the glass composition, the density and CTE of the glass composition may increase to unacceptable levels, and the ion-exchangeability of the glass may be undesirably hindered due to reduced alkali ion mobility. In embodiments, the glass composition includes CaO in an amount of 0.25 mol% to 6 mol%, e.g., 0.5 mol% to 5 mol%, 1 mol% to 4 mol%, 1.5 mol% to 3 mol%, 2 mol% to 5 mol%, and all ranges and subranges therebetween. In preferred embodiments, the glass composition includes CaO in an amount of 1 mol% to 6 mol%, or even 1.5 mol% to 6 mol%.

[0097] The glass compositions described herein may include P2O5. The inclusion of P2O5 increases the diffusivity of ions in the glass and increases the rate of the ion exchange process. If the composition contains too much P2O5, the amount of compressive stress imparted during the ion exchange process may decrease and volatility at the free surface during fabrication may increase to unacceptable levels. In embodiments, the glass compositions include P2O5 in an amount of from 0 mol% to 4 mol%, e.g., from 0 mol% to 3 mol%, from 0.5 mol% to 3.5 mol%, from 1 mol% to 3 mol%, from 1.5 mol% to 2.5 mol%, from 0.5 mol% to 2 mol%, and all ranges and subranges therebetween. In embodiments, the glass compositions are substantially free or free of P2O5.

[0098] The glass compositions described herein may include B2O3. The inclusion of B2O3 increases the fracture toughness of the glass, thereby increasing its damage resistance. Specifically, the glass compositions include boron in trigonal form, which increases the Knoop scratch threshold and fracture toughness of the glass. Including too much B2O3 in the composition reduces the amount of compressive stress imparted during the ion exchange process and may increase volatility at the free surface during fabrication to unacceptable levels. Including B2O3 in the glass composition also reduces the solution viscosity, which helps inhibit fracture of the zircon. In embodiments, the glass compositions include an amount of B2O3 from greater than or equal to 0 mol% to less than or equal to 8 mol%, e.g., from greater than or equal to 0 mol% to less than or equal to 5 mol%, from greater than 0 mol% to less than or equal to 7 mol%, from greater than or equal to 0.5 mol% to less than or equal to 6 mol%, from greater than or equal to 1 mol% to less than or equal to 5 mol%, from greater than 2 mol% to less than or equal to 4 mol%, from greater than or equal to 0 mol% to less than or equal to 3 mol%, and all ranges and subranges therebetween. In embodiments, the glass composition is substantially free or free of B2O3.

[0099] The glass compositions described herein may include SrO. SrO may reduce the viscosity of the glass, which may improve the formability, strain point, and Young's modulus. However, adding too much SrO to the glass composition may increase the density and CTE of the glass composition to unacceptable levels and may undesirably hinder the ion-exchangeability of the glass. In embodiments, the glass compositions include SrO in an amount of from 0 mol% to 3 mol%, e.g., from 0 mol% to 2 mol%, from 0.25 mol% to 2.5 mol%, from 0.5 mol% to 2 mol%, from 1 mol% to 1.5 mol%, and all ranges and subranges therebetween. In embodiments, the glass compositions are substantially free or free of SrO. As used herein, the term "substantially free" means that the component is not intentionally added as a component of the batch materials, even if the component is present in the final glass composition in very small amounts as a contaminant, such as less than 0.1 mol%.

[0100] The glass compositions described herein may include ZnO. ZnO may reduce the liquidus viscosity of the glass, which may improve formability, strain point, and Young's modulus. However, adding too much ZnO to the glass composition may increase the density and CTE of the glass composition to unacceptable levels. The inclusion of ZnO in the glass composition also provides protection against UV-induced discoloration. In embodiments, the glass composition includes an amount of ZnO from 0 mol% to 5 mol%, e.g., from 0.5 mol% to 5 mol%, from 1 mol% to 4 mol%, from 2 mol% to 3 mol%, and all ranges and subranges therebetween. In embodiments, the glass composition is substantially free or free of ZnO.

[0101] The glass compositions described herein include ZrO2. The inclusion of ZrO2 in the glass increases the fracture toughness and allows the glass composition to achieve the high fracture toughness values ​​described herein for high electric field strengths. The inclusion of ZrO2 in the glass composition also improves the chemical durability of the glass. If the glass composition contains too much ZrO2, undesirable zirconia inclusions may form in the glass due, at least in part, to the low solubility of ZrO2 in the glass. In addition, there are cost and supply constraints that make it undesirable to include too much ZrO2 in the glass composition. In embodiments, the glass composition includes ZrO2 in an amount from greater than 0 mol% to 1 mol%, e.g., from 0.25 mol% to 0.75 mol%, from 0.25 mol% to 0.5 mol%, and all ranges and subranges therebetween. In embodiments, the glass composition is substantially free or free of ZrO2.

[0102] The glass compositions described herein may include TiO2. If the glass composition contains too much TiO2, the glass may be prone to devitrification and / or exhibit undesirable coloration as well as undesirably alter the liquidus. The inclusion of some TiO2 in the glass composition may prevent undesirable discoloration of the glass when exposed to strong ultraviolet light, such as during post-fabrication processing. In embodiments, the glass composition includes TiO2 in an amount of from 0 mol% to 0.5 mol%, e.g., from 0.1 mol% to 0.4 mol%, e.g., from 0.2 mol% to 0.3 mol%, and all ranges and subranges therebetween. In embodiments, the glass composition is substantially free or free of TiO2. In preferred embodiments, the glass composition includes TiO2 in an amount of from 0 mol% to 0.2 mol%.

[0103] The glass composition may include one or more fining agents. In embodiments, an example of a fining agent may include SnO2. In embodiments, SnO2 may be present in the glass composition in an amount of 0.5 mol% or less, such as 0 mol% to 0.5 mol%, 0.05 mol% to 0.5 mol%, 0 mol% to 0.1 mol%, 0.1 mol% to 0.2 mol%, and all ranges and subranges therebetween. In some embodiments, the glass composition may be substantially free or free of SnO2. In preferred embodiments, the glass composition includes SnO2 in an amount of 0.05 mol% to 0.5 mol% or less. In embodiments, the glass composition may be substantially free of arsenic and / or antimony. In other embodiments, the glass composition may be free of arsenic and / or antimony.

[0104] The glass compositions described herein may be formed primarily from SiO2, Al2O3, Li2O, Na2O, K2O, MgO, and CaO. In embodiments, the glass compositions are substantially free or free of components other than SiO2, Al2O3, Li2O, Na2O, K2O, MgO, CaO, and fining agents. In embodiments, the glass compositions are substantially free or free of components other than SiO2, Al2O3, Li2O, Na2O, K2O, MgO, CaO, and TiO2. In embodiments, the glass compositions are substantially free or free of components other than SiO2, Al2O3, Li2O, Na2O, K2O, MgO, CaO, and TiO2 and fining agents.

[0105] In embodiments, the glass compositions may be substantially free or free of Fe2O3. Iron is often present in the raw materials utilized to form the glass compositions, and as a result, may be detectable in the glass compositions described herein even when not actively added to the glass batch.

[0106] In embodiments, the glass composition may be substantially free of, or free of, at least one of Ta2O5, HfO2, La2O3, and Y2O3. In embodiments, the glass composition may be substantially free of, or free of, Ta2O5, HfO2, La2O3, and Y2O3. These components, when included, may increase the fracture toughness of the glass, but there are cost and supply constraints that make these components undesirable for commercial purposes. Stated another way, the ability of the glass compositions described herein to achieve high fracture toughness values ​​by including Ta2O5, HfO2, La2O3, and Y2O3 provides cost and manufacturability advantages.

[0107] The physical properties of the glass compositions disclosed above are now described.

[0108] Glass compositions according to embodiments have high fracture toughness. Without intending to be bound by any particular theory, high fracture toughness may provide the glass compositions with improved drop performance. The high fracture toughness of the glass compositions described herein increases the damage resistance of the glass and allows the glass to be highly stressed by ion exchange without becoming brittle, as characterized by central tension. As utilized herein, fracture toughness is measured by the double cantilever beam (DCB) procedure, K, unless otherwise noted. IC The DCB specimen geometry is shown in Figure 2, with the parameters being the crack length a, the applied load P, the cross-sectional dimensions w and 2h, and the thickness of the crack induction groove b. The specimens are cut into rectangles with width 2h = 1.25 cm and thickness ranging from w = 0.3 mm to 1 mm, and the total length of the specimens varies from 5 cm to 10 cm, but this is not a critical dimension. Holes are drilled at both ends with a diamond drill to provide a means of attaching the specimen to a specimen holder and load. The crack "induction groove" is cut the length of the specimen into both flat sides using a wafer dicing saw with a diamond blade, leaving a "web" of material approximately half the total thickness of the plate (dimension b in Figure 2) with a height of 180 μm, which corresponds to the thickness of the blade. The precise dimensional tolerances of the dicing saw allow for minimal variation between specimens. This dicing saw is also used to cut the initial crack with a = 15 mm. This final operation results in the formation of a very thin wedge of material near the crack tip (due to the curvature of the blade), making it easier for crack initiation within the sample. The sample is mounted in a metal sample holder with a steel wire in the hole at the bottom of the sample. The sample is also supported at the opposite end to keep it horizontal under low load conditions. A spring in series with a load cell (FUTEK, LSB200) is hooked to the top hole, which is then stretched and gradually loaded using a rope and precision slide. The crack is monitored using a microscope with a resolution of 5 μm attached to a digital camera and computer. The following equation:

[0109]

number

[0110] Using the applied stress intensity K P For each specimen, a crack was first initiated at the tip of the web, and then the initiating crack was carefully grown subcritically until the dimension ratio a / h was greater than 1.5 in order to accurately calculate the stress intensity. At this point, the length a of the crack was measured and recorded using a moving microscope with a resolution of 5 μm. A drop of toluene was then placed in the crack groove and carried along the length of the groove by capillary forces, pinning the crack against movement until the fracture toughness was reached. The load was then increased until the specimen broke, and the critical stress intensity K was calculated from the fracture load and specimen dimensions. IC Calculate K P is the measurement method, K IC In addition, K IC The value is the K before the glass-based substrate is ion-exchanged to form the glass-based article. IC The K values ​​mentioned here are measured on unstrengthened glass samples. IC Values ​​are in MPa m unless otherwise stated 0.5 has been reported.

[0111] In an embodiment, the glass composition has a compressive strength of 0.75 MPa m 0.5 For example, 0.76 MPa m 0.5 More than 0.77MPa m 0.5 More than 0.78MPa m 0.5 More than 0.79MPa m 0.5 More than 0.80MPa m 0.5 More than 0.81MPa m 0.5 More than 0.82MPa m 0.5 More than 0.83MPa m 0.5 More than 0.84MPa m 0.5 More than 0.85MPa m 0.5 More than 0.86MPa m 0.5 More than 0.87MPa m 0.5 Above, 0.88MPa m 0.5 More than 0.89MPa m 0.5 Greater than or equal to K ICIn one embodiment, the glass composition has a hardness of 0.75 MPa m 0.5 Above 0.9MPa m 0.5 For example, 0.76 MPa m 0.5 Above 0.89MPa m 0.5 Below, 0.77MPa m 0.5 Above 0.88MPa m 0.5 Below, 0.78MPa m 0.5 Above 0.87MPa m 0.5 Below, 0.79MPa m 0.5 Above 0.86MPa m 0.5 Below, 0.80MPa m 0.5 Above 0.85MPa m 0.5 Below, 0.81MPa m 0.5 Above 0.84MPa m 0.5 Below, 0.82MPa m 0.5 Above 0.83MPa m 0.5 All ranges and subranges between the following and preceding values ​​of K IC Indicates the value.

[0112] Glass compositions according to embodiments have a high Young's modulus. High Young's modulus values ​​reduce the stored strain energy present in the glass after ion exchange. As used herein, Young's modulus (E) refers to a value measured by a resonant ultrasonic spectroscopy technique of the general type described in ASTM E2001-13, entitled "Standard Guide for Resonant Ultrasound Spectroscopy for Defect Detection in Both Metallic and Non-metallic Parts." In embodiments, the glass compositions have a Young's modulus of 80 GPa or more, e.g., 81 GPa or more, 82 GPa or more, 83 GPa or more, 84 GPa or more, 85 GPa or more, 86 GPa or more, 87 GPa or more, 88 GPa or more, 89 GPa or more, or more. In embodiments, the glass composition has a Young's modulus of from 80 GPa to 90 GPa, e.g., from 81 GPa to 89 GPa, from 82 GPa to 88 GPa, from 83 GPa to 87 GPa, from 84 GPa to 86 GPa, from 80 GPa to 85 GPa, and all ranges and subranges therebetween.

[0113] The glass compositions described herein have liquidus viscosities compatible with manufacturing processes that are particularly suited for forming thin glass sheets. For example, the glass compositions are compatible with conventional forming methods such as float, rolling, or pressing. Glass-based substrate embodiments may be described as fusion formable (i.e., formable using a fusion draw process). The fusion process uses a draw vessel having a passageway for receiving molten raw glass material. The passageway has a weir on either side of the passageway that is open at the top along the length of the passageway. When the passageway is filled with molten material, the molten glass overflows the weir. The molten glass flows down the exterior surfaces of the draw vessel as two flowing glass films due to gravity. These exterior surfaces of the draw vessel extend downward and inward to meet at the lower edge of the draw vessel. The two flowing glass films meet at this edge and fuse to form a flowing glass-based article. The fusion of these glass films creates a fusion line in the glass-based substrate that can identify a fusion-formed glass-based substrate without the need for additional knowledge of its manufacturing history. The fusion draw process offers the advantage that, as the two glass films overflowing the passageway fuse together, none of the exterior surfaces of the resulting glass-based article come into contact with any part of the equipment. Thus, the surface properties of the glass-based article produced by the fusion draw process are not affected by such contact.

[0114] The glass compositions described herein may be selected to have a liquidus viscosity that is compatible with the fusion draw process. Thus, the glass compositions described herein are compatible with existing forming processes, increasing the manufacturability of glass-based articles formed from the glass compositions. In embodiments, the glass compositions have a liquidus viscosity of 50 kP or more, e.g., 60 kP or more, 70 kP or more, 80 kP or more, 90 kP or more, 100 kP or more, 110 kP or more, 120 kP or more, 130 kP or more, 140 kP or more, 150 kP or more, 160 kP or more, 170 kP or more, 180 kP or more, 190 kP or more, 200 kP or more, 210 kP or more, 220 kP or more, or more. In embodiments, the glass composition has a liquidus viscosity of from 50 kP to 230 kP, e.g., from 60 kP to 220 kP, from 70 kP to 210 kP, from 80 kP to 200 kP, from 90 kP to 190 kP, from 100 kP to 180 kP, from 110 kP to 170 kP, from 120 kP to 160 kP, from 130 kP to 150 kP, from 50 kP to 140 kP, and all ranges and subranges therebetween. As used herein, the term "liquidus viscosity" refers to the viscosity of a molten glass at its liquidus temperature, where the liquidus temperature refers to the temperature at which crystals first appear as the molten glass cools from the melting temperature or at which the last crystals melt away as the temperature is increased from room temperature. Unless otherwise specified, the liquidus viscosity values ​​disclosed in this application are determined by the following method: First, the liquidus temperature of the glass is measured according to ASTM C829-81(2015), entitled "Standard Practice for Measurement of Liquidus Temperature of Glass by the Gradient Furnace Method." Then, the viscosity of the glass at its liquidus temperature is measured according to ASTM C965-96(2012), entitled "Standard Practice for Measuring Viscosity of Glass Above the Softening Point."Unless otherwise specified, the liquidus viscosity and temperature of a glass composition or article are measured before the composition or article is subjected to any ion exchange process or any other strengthening process. In particular, the liquidus viscosity and temperature of a glass composition or article are measured before the composition or article is exposed to, e.g., immersed in, an ion exchange solution.

[0115] In one or more embodiments, the glass compositions described herein may form glass-based articles that exhibit an amorphous microstructure and may be substantially free of crystals or crystallites. In other words, glass-based articles formed from the glass compositions described herein may exclude glass-ceramic materials.

[0116] As mentioned above, in embodiments, the glass compositions described herein can be strengthened, such as by ion exchange, to produce glass-based articles that are damage resistant for applications such as, but not limited to, display covers. Referring to FIG. 1, a glass-based article is shown having a first region under compressive stress (e.g., first and second compressive stress layers 120, 122 in FIG. 1) extending from the surface of the glass-based article to a depth of compression (DOC) and a second region under tensile stress or central tension (CT) (e.g., central region 130 in FIG. 1) extending from the DOC to a central or interior region of the glass-based article. As used herein, DOC refers to the depth at which stress within a glass-based article changes from compression to tension. At the DOC, the stress crosses from positive (compressive) stress to negative (tensile) stress, and therefore exhibits a stress value of zero.

[0117] According to common conventions in the art, compression or compressive stress is expressed as a negative (<0) stress, and tension or tensile stress is expressed as a positive (>0) stress. However, throughout this specification, CS is expressed as a positive or absolute value. That is, as set forth herein, CS=|CS|. Compressive stress (CS) has a maximum value at or near the surface of the glass-based article, and CS varies with distance d from the surface according to a function. Referring again to FIG. 1, the first section 120 extends from the first surface 110 to a depth d1, and the second section 122 extends from the second surface 112 to a depth d2. These sections together define the compression or CS of the glass-based article 100. Surface compressive stress (CS) may be measured using a scattered light polariscope (SCALP) technique known in the art.

[0118] In embodiments, the CS of the glass-based article is from 400 MPa to 2000 MPa, e.g., from 500 MPa to 1900 MPa, from 600 MPa to 1800 MPa, from 700 MPa to 1700 MPa, from 800 MPa to 1300 MPa, from 900 MPa to 1200 MPa, from 1000 MPa to 1100 MPa, and all ranges and sub-ranges therebetween.

[0119] In one embodiment, Na + and K. + ions are exchanged into the glass-based article, + The ion is K + ions diffuse into glass-based articles to greater depths than K + The depth of penetration of ions ("potassium DOL") is distinct from the DOC because it represents the depth of potassium penetration as a result of the ion exchange process. The potassium DOL is typically smaller than the DOC for the glass articles described herein. The potassium DOL may be measured using a surface stress meter, such as the commercially available FSM-6000 surface stress meter manufactured by Orihara Seisakusho Co., Ltd. (Japan). This surface stress meter relies on precise measurements of the stress optical coefficient (SOC). The potassium DOL is calculated by measuring the depth of the compressive stress spike (DOL SP), where the stress profile transitions from a steep spike region to a less steep deep region. The deep region extends from the base of the spike region to the compression depth. SP can be from 3 μm to 15 μm, e.g., from 4 μm to 14 μm, from 5 μm to 13 μm, from 6 μm to 12 μm, from 7 μm to 11 μm, from 8 μm to 10 μm, from 9 μm to 15 μm, and all ranges and sub-ranges therebetween.

[0120] The compressive stresses on both major surfaces (110, 112 in FIG. 1) are balanced by a stored tension in the central region (130) of the glass-based article. The surface compressive stress (CS), maximum central tension (CT), and DOC may be measured using the scattered light polariscope (SCALP) technique, which is known in the art. The SCALP method may also be used to determine the stress profile of the glass-based article.

[0121] The measurement of maximum CT value is an indication of the total amount of stress stored in a reinforced article. For this reason, the ability to achieve higher CT values ​​correlates to the ability to achieve higher degrees of reinforcement and improved performance. In embodiments, the glass-based article may have a maximum CT of 30 MPa or more to 180 MPa or less, e.g., 40 MPa or more to 170 MPa or less, 50 MPa or more to 160 MPa or less, 60 MPa or more to 150 MPa or less, 70 MPa or more to 140 MPa or less, 80 MPa or more to 130 MPa or less, 90 MPa or more to 120 MPa or less, 100 MPa or more to 110 MPa or less, and all ranges and subranges therebetween.

[0122] The high fracture toughness values ​​of the glass compositions described herein may also allow for improved performance. The brittleness limit of glass-based articles manufactured utilizing the glass compositions described herein depends at least in part on the fracture toughness. For this reason, the high fracture toughness of the glass compositions described herein allows the glass-based articles formed therefrom to have a large amount of stored strain energy without becoming brittle. The increased amount of stored strain energy that may be included in the glass-based article may then allow the glass-based article to exhibit increased fracture resistance, which may be observed through the drop performance of the glass-based article. The relationship between brittleness limit and fracture toughness is described in U.S. Patent Application Publication No. 2020 / 0079689A1, entitled "Glass-based Articles with Improved Fracture Resistance," published March 12, 2020, which is incorporated herein by reference in its entirety. The relationship between fracture toughness and drop performance is described in U.S. Patent Application Publication No. 2019 / 0369672 A1, entitled "Glass with Improved Drop Performance," published on December 5, 2019, which is incorporated herein by reference in its entirety.

[0123] As mentioned above, the DOC is measured using a scattered light polarimeter (SCALP) known in the art. The DOC is given herein as a fraction of the thickness (t) of the glass-based article in some embodiments. In embodiments, the glass-based article may have a depth of compression (DOC) of 0.15t or more to 0.25t or less, such as 0.16t or more to 0.24t or less, 0.17t or more to 0.23t or less, 0.18t or more to 0.22t or less, 0.19t or more to 0.20t or less, 0.15t or more to 0.21t or less, and all ranges and subranges therebetween. The high DOC values ​​that result when the glass compositions described herein are ion-exchanged provide improved fracture resistance, especially for situations where deep scratches may be introduced. For example, a deep DOC improves fracture resistance when dropped onto a rough surface.

[0124] The thickness (t) of the glass-based article 100 is measured between the surface 110 and the surface 112. In embodiments, the thickness of the glass-based article 100 can be in the range of 0.1 mm to 4 mm, e.g., 0.2 mm to 2 mm, 0.2 mm to 3.5 mm, 0.3 mm to 3 mm, 0.4 mm to 2.5 mm, 0.5 mm to 2 mm, 0.6 mm to 1.5 mm, 0.7 mm to 1 mm, 0.2 mm to 2 mm, and all ranges and subranges therebetween. In preferred embodiments, the glass-based article has a thickness of 0.2 mm to 2 mm. The glass substrate utilized to form the glass-based article can have the same thickness as desired for the glass-based article.

[0125] The compressive stress layer may be formed in the glass by exposing the glass to an ion-exchange medium. In embodiments, the ion-exchange medium may be a molten salt bath, such as a bath containing molten nitrates. In embodiments, the ion-exchange medium may be a molten salt bath including KNO3, NaNO3, or combinations thereof. In embodiments, other sodium and potassium salts may be used in the ion-exchange medium, such as, for example, sodium or potassium nitrates, phosphates, or sulfates. In embodiments, the ion-exchange medium may include a lithium salt, such as LiNO3. The ion-exchange medium may additionally include additives commonly included when ion-exchanging glasses, such as silicic acid. The ion-exchange process is performed on the glass-based substrate to form a glass-based article that includes a compressive stress layer and a central tension region that extend from the surface to the compression depth of the glass-based article. The glass-based substrate utilized in the ion-exchange process may include any of the glass compositions described herein.

[0126] In an embodiment, the ion exchange medium includes NaNO3. The sodium in the ion exchange medium exchanges with lithium ions in the glass to create a compressive stress. In an embodiment, the ion exchange medium may include 95% or less by weight NaNO3, e.g., 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or less. In an embodiment, the ion exchange medium may include 5% or more by weight NaNO3, e.g., 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or more. In embodiments, the ion exchange medium may include NaNO3 in an amount of from 0 to 100% by weight, such as from 10 to 90%, from 20 to 80%, from 30 to 70%, from 40 to 60%, from 50 to 90%, and all ranges and subranges therebetween. In embodiments, the molten ion exchange bath includes 100% NaNO3 by weight.

[0127] In embodiments, the ion exchange medium comprises KNO3. In embodiments, the ion exchange medium may comprise 95% by weight or less, e.g., 90% by weight or less, 80% by weight or less, 70% by weight or less, 60% by weight or less, 50% by weight or less, 40% by weight or less, 30% by weight or less, 20% by weight or less, 10% by weight or less, or less than that. In embodiments, the ion exchange medium may comprise 5% by weight or more, e.g., 10% by weight or more, 20% by weight or more, 30% by weight or more, 40% by weight or more, 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, or more than that. In embodiments, the ion exchange medium may include KNO3 in an amount of from 0 to 100% by weight, such as from 10 to 90%, from 20 to 80%, from 30 to 70%, from 40 to 60%, from 50 to 90%, and all ranges and subranges therebetween. In embodiments, the molten ion exchange bath includes 100% KNO3 by weight.

[0128] The ion exchange medium may include a mixture of sodium and potassium. In embodiments, the ion exchange medium is a mixture of potassium and sodium, such as a molten salt bath containing both NaNO3 and KNO3. In embodiments, the ion exchange medium may include any combination of NaNO3 and KNO3 in the amounts described above, such as a molten salt bath containing 40% NaNO3 and 60% KNO3 by weight.

[0129] The glass composition may be exposed to an ion exchange medium by immersing a glass substrate made from the glass composition in a bath of the ion exchange medium, spraying the ion exchange medium onto a glass substrate made from the glass composition, or otherwise physically applying the ion exchange medium to a glass substrate made from the glass composition to form an ion exchanged glass-based article. The ion exchange medium may be at a temperature of from 400° C. to 550° C., e.g., from 410° C. to 540° C., from 420° C. to 530° C., from 430° C. to 520° C., from 440° C. to 510° C., from 450° C. to 500° C., from 460° C. to 490° C., from 470° C. to 480° C., and all ranges and subranges therebetween during exposure to the glass composition, according to embodiments. In embodiments, the glass composition may be exposed to the ion exchange solution for a period of from 0.5 hours to 48 hours, e.g., from 1 hour to 24 hours, from 2 hours to 12 hours, from 1 hour to 18 hours, from 2 hours to 16 hours, from 7 hours to 12 hours, and all ranges and subranges therebetween.

[0130] The ion exchange process may include a second ion exchange process. In embodiments, the second ion exchange process may include ion exchanging the glass-based article in a second molten salt bath. The second ion exchange process may utilize any of the ion exchange media described herein at any of the conditions (temperature and time) described herein. In embodiments, the second ion exchange process utilizes a second molten salt bath that includes KNO3, such as a molten salt bath that includes 100% KNO3 by weight.

[0131] The ion exchange process may be carried out in an ion exchange medium under processing conditions that provide an improved compressive stress profile, such as those disclosed in U.S. Patent Application Publication No. 2016 / 0102011, which is incorporated herein by reference in its entirety. In some embodiments, the ion exchange process may be selected to produce a parabolic stress profile in the glass-based article, such as the stress profile described in U.S. Patent Application Publication No. 2016 / 0102014, which is incorporated herein by reference in its entirety.

[0132] It should be understood that after the ion-exchange process has been performed, the composition at the surface of the ion-exchanged glass-based article will differ from the composition of the as-formed glass substrate (i.e., the glass substrate before the ion-exchange process has been performed). + or K + Replaced by larger alkali metal ions such as Li + or Na + Such glass compositions may result from one type of alkali metal ion in the as-formed glass substrate, such as ion-exchanged glass, ion-exchanged glass, etc. However, the glass composition at or near the center of the depth of the glass-based article will, in embodiments, still have the composition of the as-formed, non-ion-exchanged glass substrate utilized to form the glass-based article. As used herein, the center of a glass-based article refers to any location in the glass-based article that is at least 0.5t away from all of its surfaces, where t is the thickness of the glass-based article.

[0133] The glass-based articles disclosed herein may be incorporated into another article, such as an article with a display (or display article) (e.g., consumer electronics including cell phones, tablets, computers, navigation systems, etc.), a building article, a transportation article (e.g., automobiles, trains, aircraft, ships, etc.), an appliance, or any article requiring some degree of transparency, scratch resistance, abrasion resistance, or a combination thereof. An exemplary article incorporating any of the glass-based articles disclosed herein is shown in Figures 3A and 3B. In particular, Figures 3A and 3B show a consumer electronics device 200 comprising a housing 202 having a front surface 204, a back surface 206, and a side surface 208; at least partially inside or completely within the housing, electrical components (not shown) including at least a controller, memory, and a display 210 at or adjacent to the front surface of the housing; and a cover 212 at or on the front surface of the housing to cover the display. In an embodiment, at least a portion of at least one of the cover 212 and the housing 202 may include any of the glass-based articles described herein. EXAMPLES

[0134] The embodiments will be further clarified by the following examples, which should be understood as not limiting the embodiments described above.

[0135] Glass compositions were prepared and analyzed. The analyzed glass compositions contained the components listed in Table I below and were prepared by conventional glass forming methods. In Table I, all components are expressed in mole percent and are K. ICThe fracture toughness was measured by the double cantilever beam (DCB) method described herein. The liquidus temperature and liquidus viscosity were measured according to the methods described herein. The Poisson's ratio (ν), Young's modulus (E), and shear modulus (G) of the glass compositions were measured by the general type of resonant ultrasonic spectroscopy technique described in ASTM E2001-13, entitled "Standard Guide for Resonant Ultrasound Spectroscopy for Defect Detection in Both Metallic and Non-metallic Parts". The refractive index and stress optical coefficient (SOC) at 589.3 nm of the substrates are also reported in Table I. The refractive index was measured using a PerkinElmer 950 spectrometer. The SOC was measured according to procedure C (glass disk method) described in ASTM standard C770-16, entitled "Standard Test Method for Measurement of Glass Stress-Optical Coefficient". The density of the glass compositions was determined using the buoyancy method of ASTM C693-93 (2013).

[0136] [Table 1-1a]

[0137] [Table 1-1b]

[0138] [Table 1-2a]

[0139] [Table 1-2b]

[0140] Substrates were formed from the compositions in Table I and subsequently ion-exchanged to form the exemplary articles. The ion-exchange involved immersing the substrate in a molten salt bath. The salt bath included 40% NaNO3 and 60% KNO3 by weight. Table II lists the thickness of the article, the length of ion-exchange, the bath temperature, the mass gain that occurred during the ion-exchange process, and the maximum central tension (CT), surface compressive stress (CS), and spike depth (DOL) of the ion-exchanged article. SP ) has been reported. Maximum central tension (CT) was measured according to the method described therein.

[0141] [Table 2-1]

[0142] [Table 2-2]

[0143] A 0.6 mm thick substrate was formed from composition II of Table I and subsequently ion-exchanged to form a chemically strengthened article. The ion exchange involved immersing the substrate in a first salt bath containing 40 wt. % NaNO3 and 60 wt. % KNO3 at a bath temperature of 430° C. for 10 hours, and then immersing the substrate in a second salt bath containing 100 wt. % KNO3 at a bath temperature of 430° C. for 0.5 hours. The resulting article had a surface compressive stress (CS) of 1.4 GPa, a maximum central tension (CT) of 120.1 MPa, and a spike depth (DOL) of 7.3 μm. SP )

[0144] All compositional components, relationships, and ratios described herein are given in mole percent unless otherwise specified. All ranges disclosed herein include any and all ranges and subranges encompassed by the broadly disclosed range, whether or not a range is expressly set forth before or after the disclosure.

[0145] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments disclosed herein without departing from the spirit and scope of the claimed subject matter. Therefore, it is intended that this specification cover modifications and variations of the various embodiments described herein, provided such modifications and variations come within the scope of the appended claims and their equivalents.

[0146] Preferred embodiments of the present invention will be described below in detail.

[0147] EMBODIMENT 1 A glass, SiO2, from 56 mol% to 70 mol% 12 mol% or more and 20 mol% or less of Al2O3, 0 mol% to 4 mol% P2O5, 0 mol% to 8 mol% B2O3, 6 mol % or more and 12 mol % or less of Li2O; 4 mol% or more and 12 mol% or less of Na2O, 0.4 mol % or more and 3 mol % or less of K2O, 2 mol % or more and 6 mol % or less of MgO; 0.25 mol% or more and 6 mol% or less of CaO; 0 mol % or more and 3 mol % or less of SrO; 0 mol % to 5 mol % ZnO, and 0 mol% to 1 mol% ZrO2; Including glass.

[0148] EMBODIMENT 2 2. The glass of embodiment 1 comprising from 60 mol % to 64 mol % SiO2.

[0149] EMBODIMENT 3 3. The glass of embodiment 1 or 2 comprising from 14 mol % to 16 mol % Al2O3.

[0150] EMBODIMENT 4 4. The glass of any one of the preceding claims, comprising from 8 mol % to 9 mol % LiO.

[0151] EMBODIMENT 5 5. The glass of any one of the preceding claims, comprising from 7 mol % to 12 mol % Na2O.

[0152] EMBODIMENT 6 6. The glass of any one of the preceding claims, comprising from 7 mol% to 11 mol% Na2O.

[0153] EMBODIMENT 7 7. The glass of any one of the preceding embodiments comprising from 0.4 mol % to 1 mol % of K2O.

[0154] EMBODIMENT 8 8. The glass of any one of the preceding claims comprising 2.5 mol % to 4 mol % MgO.

[0155] EMBODIMENT 9 9. The glass of any one of the preceding embodiments comprising from ≧1 mol % to ≦6 mol % CaO.

[0156] EMBODIMENT 10 10. The glass of any one of the preceding embodiments comprising ≧1.5 mol % to ≦6 mol % CaO.

[0157] EMBODIMENT 11 11. The glass of any one of the preceding claims, comprising from 0.05 mol % to 0.5 mol % SnO2.

[0158] EMBODIMENT 12 12. The glass of any one of the preceding claims, comprising from 0 to 0.2 mol % TiO2.

[0159] EMBODIMENT 13 13. The glass of any one of claims 1 to 12, wherein the glass is substantially free of TiO2.

[0160] EMBODIMENT 14 14. The glass of any one of the preceding claims, wherein the glass is substantially free of P2O5.

[0161] EMBODIMENT 15 15. The glass of any one of the preceding embodiments comprising from 0 to 5 mol % B2O3.

[0162] EMBODIMENT 16 16. The glass of any one of the preceding claims, wherein the glass is substantially free of B2O3.

[0163] EMBODIMENT 17 17. The glass of any one of the preceding embodiments, comprising from 0 to 2 mol % SrO.

[0164] EMBODIMENT 18 18. The glass of any one of the preceding claims, wherein the glass is substantially free of SrO.

[0165] EMBODIMENT 19 19. The glass of any one of the preceding claims, wherein the glass is substantially free of ZnO.

[0166] EMBODIMENT 20 20. The glass of any one of the preceding claims, wherein the glass is substantially free of ZrO2.

[0167] EMBODIMENT 21 21. The glass of any one of the preceding claims, wherein the glass is substantially free of Fe2O3.

[0168] EMBODIMENT 22 22. The glass of any of the preceding claims, wherein the glass is substantially free of Ta2O5, HfO2, La2O3, and Y2O3.

[0169] EMBODIMENT 23 23. The glass of any of the preceding claims, wherein the glass has a liquidus viscosity of 50 kP or greater.

[0170] EMBODIMENT 24 The glass has a viscosity of 0.75 MPa m 0.5 Above 0.9MPa·M 0.5 Fracture toughness K IC 24. The glass of any one of the preceding claims, having

[0171] EMBODIMENT 25 25. The glass of any one of the preceding claims, wherein the glass has a Young's modulus of 80 GPa or more and 90 GPa or less.

[0172] EMBODIMENT 26 In the method, ion exchanging the glass-based substrate in a molten salt bath to form a glass-based article; Including, 26. The method of claim 1, wherein the glass-based article comprises a compressive stress layer extending from a surface of the glass-based article to a compression depth, the glass-based article comprises a central tension region, and the glass-based substrate is made from the glass of any of claims 1 to 25.

[0173] EMBODIMENT 27 27. The method of embodiment 26, wherein the molten salt bath comprises NaNO.

[0174] EMBODIMENT 28 28. The method of embodiment 26 or 27, wherein the molten salt bath comprises KNO.

[0175] EMBODIMENT 29 29. The method of any of claims 26 to 28, wherein the molten salt bath comprises NaNO3 and KNO3.

[0176] EMBODIMENT 30 30. The method of any one of embodiments 26 to 29, wherein the molten salt bath is at a temperature of from 400° C. to 550° C.

[0177] EMBODIMENT 31 31. The method of any of embodiments 26 to 30, wherein the ion exchange is for a period of not less than 0.5 hours and not more than 48 hours.

[0178] EMBODIMENT 32 32. The method of any of claims 26 to 31, further comprising ion exchanging the glass-based article in a second molten salt bath.

[0179] EMBODIMENT 33 33. The method of any one of claims 26 to 32, wherein the second molten salt bath comprises KNO3.

[0180] EMBODIMENT 34 34. The method of any of embodiments 32-33, wherein the ion exchange in the second molten salt bath lasts for a period of 0.5 hours or more and 48 hours or less.

[0181] EMBODIMENT 35 In glass-based articles, a compressive stress layer extending from the surface of the glass-based article to a compression depth; a central tension area, and SiO2, from 56 mol% to 70 mol% 12 mol% or more and 20 mol% or less of Al2O3, 0 mol% to 4 mol% P2O5, 0 mol% to 8 mol% B2O3, 6 mol % or more and 12 mol % or less of Li2O; 4 mol% or more and 12 mol% or less of Na2O, 0.4 mol % or more and 3 mol % or less of K2O, 2 mol % or more and 6 mol % or less of MgO; 0.25 mol% or more and 6 mol% or less of CaO; 0 mol % or more and 3 mol % or less of SrO; 0 mol % to 5 mol % ZnO, and 0 mol% to 1 mol% ZrO2; A composition at the center of the glass-based article comprising: A glass-based article having the following structure.

[0182] EMBODIMENT 36 36. The glass-based article of embodiment 35, wherein the compressive stress layer has a compressive stress of from 400 MPa or more to 2000 MPa or less.

[0183] EMBODIMENT 37 37. The glass-based article of claim 35 or 36, wherein the central tension zone has a maximum central tension of from 30 MPa or more to 180 MPa or less.

[0184] EMBODIMENT 38 38. The glass-based article of any of claims 35-37, wherein the compression depth is from 0.15t to 0.25t, inclusive, where t is the thickness of the glass-based article.

[0185] EMBODIMENT 39 39. The glass-based article of any of claims 35 to 38, wherein the compressive stress layer has a compressive stress spike extending from a surface of the glass-based article to a compressive stress spike depth, the compressive stress spike depth being from 3 μm or more to 15 μm or less.

[0186] EMBODIMENT 40 40. The glass-based article of any of claims 35 to 39, wherein the glass-based article has a thickness, t, of from 0.2 mm or more to 2 mm or less.

[0187] EMBODIMENT 41 41. The glass-based article of any of claims 35 to 40, wherein the composition at the center of the glass-based article comprises from 60 mol% to 64 mol% SiO2.

[0188] EMBODIMENT 42 42. The glass-based article of any of claims 35 to 41, wherein the composition at the center of the glass-based article comprises from 14 mol% to 16 mol% Al2O3.

[0189] EMBODIMENT 43 43. The glass-based article of any of claims 35 to 42, wherein the composition at the center of the glass-based article comprises from 8 mol% to 9 mol% LiO.

[0190] EMBODIMENT 44 44. The glass-based article of any of claims 35 to 43, wherein the composition at the center of the glass-based article comprises from 7 mol% to 12 mol% Na2O.

[0191] EMBODIMENT 45 45. The glass-based article of any of claims 35 to 44, wherein the composition at the center of the glass-based article comprises from 7 mol% to 11 mol% Na2O.

[0192] EMBODIMENT 46 46. ​​The glass-based article of any of claims 35 to 45, wherein the composition at the center of the glass-based article comprises from 0.4 mol% to 1 mol% KO.

[0193] EMBODIMENT 47 47. The glass-based article of any of claims 35 to 46, wherein the composition at the center of the glass-based article comprises from ≧2.5 mol% to ≦4 mol% MgO.

[0194] EMBODIMENT 48 48. The glass-based article of any of claims 35 to 47, wherein the composition at the center of the glass-based article comprises from ≧1.5 mol% to ≦6 mol% CaO.

[0195] EMBODIMENT 49 49. The glass-based article of any of claims 35 to 48, wherein the composition at the center of the glass-based article comprises from ≧1 mol% to ≦6 mol% CaO.

[0196] EMBODIMENT 50 50. The glass-based article of any one of claims 35 to 49, wherein the composition at the center of the glass-based article comprises from 0.05 mol% to 0.5 mol% SnO2.

[0197] EMBODIMENT 51 51. The glass-based article of any of claims 35 to 50, wherein the composition at the center of the glass-based article comprises from greater than or equal to 0 mol% to less than or equal to 0.2 mol% TiO2.

[0198] EMBODIMENT 52 52. The glass-based article of any of claims 35 to 51, wherein the composition at the center of the glass-based article is substantially free of TiO2.

[0199] EMBODIMENT 53 53. The glass-based article of any of claims 35 to 52, wherein the composition at the center of the glass-based article is substantially free of P2O5.

[0200] EMBODIMENT 54 55. The glass-based article of any of claims 35 to 54, wherein the composition at the center of the glass-based article comprises from greater than or equal to 0 mol% to less than or equal to 5 mol% B2O3.

[0201] EMBODIMENT 55 55. The glass-based article of any of claims 35 to 54, wherein the composition at the center of the glass-based article is substantially free of B2O3.

[0202] EMBODIMENT 56 56. The glass-based article of any of claims 35 to 55, wherein the composition at the center of the glass-based article comprises from greater than or equal to 0 mol% to less than or equal to 2 mol% SrO.

[0203] EMBODIMENT 57 57. The glass-based article of any of claims 35 to 56, wherein the composition at the center of the glass-based article is substantially free of SrO.

[0204] EMBODIMENT 58 58. The glass-based article of any of claims 35 to 57, wherein the composition at the center of the glass-based article is substantially free of ZnO.

[0205] EMBODIMENT 59 59. The glass-based article of any of claims 35 to 58, wherein the composition at the center of the glass-based article is substantially free of ZrO2.

[0206] EMBODIMENT 60 60. The glass-based article of any of claims 35 to 59, wherein the composition at the center of the glass-based article is substantially free of Fe2O3.

[0207] EMBODIMENT 61 61. The glass-based article of any of claims 35 to 60, wherein the composition at the center of the glass-based article is substantially free of Ta2O5, HfO2, La2O3, and Y2O3.

[0208] EMBODIMENT 62 62. The glass-based article of any of claims 35 to 61, wherein a glass having the same composition and microstructure as the composition at the center of the glass-based article has a liquidus viscosity of 50 kP or greater.

[0209] EMBODIMENT 63 A glass having the same composition and microstructure as that at the center of the glass-based article is melted to a temperature of 0.75 MPa m 0.5 Above 0.9MPa·M 0.5 Fracture toughness K IC 63. The glass-based article of any of claims 35 to 62, having

[0210] EMBODIMENT 64 64. The glass-based article of any of claims 35 to 63, wherein a glass having the same composition and microstructure as the composition at the center of the glass-based article has a Young's modulus of 80 GPa or more and 90 GPa or less.

[0211] EMBODIMENT 65 In consumer electronics, a housing having a front, a back, and sides; Electrical components disposed at least partially within said housing, the electrical components including at least a controller, a memory, and a display disposed on or adjacent a front surface of the housing; and a cover substrate disposed over the display; Equipped with 65. A consumer electronic product, wherein at least a portion of at least one of the housing and the cover substrate is made from the glass-based article of any of claims 35 to 64. [Explanation of symbols]

[0212] 100 Glass-based products 110 First Surface 112 Second Surface 120 First Section 122 Second Section 130 Central area 200 Household electronics 202 Case 204 Front 206 Back 208 Side 210 Display 212 Cover

Claims

1. It is glass, 56 mol% or more to 70 mol% or less of SiO ２ , 14 mol% or more to 20 mol% or less of Al ２ O ３ , 0 mol % to 4 mol % P ２ O ５ , 0 mol % or more to 8 mol % or less of B ２ O ３ , 6 mol% or more to 12 mol% or less of Li ２ O. 4 mol% to 12 mol% Na ２ O. 0.4 mol % or more to 3 mol % or less of K ２ O. 2 mol% or more and 6 mol% or less of MgO; 0.25 mol% or more and 6 mol% or less of CaO; 0 mol % to 3 mol % SrO, 0 mol% to 5 mol% ZnO, and 0 mol % to 1 mol % ZrO ２ , Glass containing.

2. 0.05 mol % or more to 0.5 mol % or less of SnO ２ The glass of claim 1 comprising:

3. 0 mol % or more to 0.2 mol % or less of TiO ２ 3. The glass of claim 1, comprising:

4. The glass contains Fe ２ O ３ , Ta ２ O ５ , HfO ２ , La ２ O ３ , and Y ２ O ３ 3. The glass of claim 1, wherein the glass is substantially free of:

5. In the method, ion-exchanging the glass-based substrate in a molten salt bath to form a glass-based article; Including, 3. The method of claim 1, wherein the glass-based article comprises a compressive stress layer extending from a surface of the glass-based article to a compression depth, the glass-based article comprises a central tension region, and the glass-based substrate is made from the glass of claim 1 or 2.

6. In glass-based articles, a compressive stress layer extending from the surface of the glass-based article to a compression depth; the central tension area, and 56 mol% or more to 70 mol% or less of SiO ２ , 14 mol% or more to 20 mol% or less of Al ２ O ３ , 0 mol % to 4 mol % P ２ O ５ , 0 mol % or more to 8 mol % or less of B ２ O ３ , 6 mol% or more to 12 mol% or less of Li ２ O. 4 mol% to 12 mol% Na ２ O. 0.4 mol % or more to 3 mol % or less of K ２ O. 2 mol% or more and 6 mol% or less of MgO; 0.25 mol% or more and 6 mol% or less of CaO; 0 mol % to 3 mol % SrO, 0 mol% to 5 mol% ZnO, and 0 mol % to 1 mol % ZrO ２ , a composition at the center of the glass-based article comprising: A glass-based article having the following structure.

7. The glass-based article according to claim 6, wherein the compressive stress layer has a compressive stress of 400 MPa or more and 2000 MPa or less.

8. 7. The glass-based article of claim 6, wherein the central tension region has a maximum central tension of 30 MPa or more and 180 MPa or less.

9. 9. The glass-based article of any one of claims 6 to 8, wherein the compression depth is from 0.15t to 0.25t, inclusive, where t is the thickness of the glass-based article.

10. 9. The glass-based article of any one of claims 6 to 8, wherein the compressive stress layer comprises a compressive stress spike extending from a surface of the glass-based article to a compressive stress spike depth, the compressive stress spike depth being from 3 μm or more to 15 μm or less.

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