Glass-based articles with improved fracture resistance

Abstract

To provide glass-based articles that exhibit improved fracture resistance.SOLUTION: Relationships between properties attributable to the glass composition and stress profile of the glass-based articles are provided which indicate improved fracture resistance. Specifically, a glass-based article is provided which includes: a first surface; a second surface; and a stress profile having a first compressive region extending from a first surface to a first depth of compression DOC1, a second compressive region extending from a second surface to a second depth of compression DOC2, and a tensile region extending from DOC1 to DOC2, where the tensile region has a tensile stress factor KT greater than or equal to 1.31 MPa √(m) and less than 1.8 KIC, where KIC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article.SELECTED DRAWING: Figure 1

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority from U.S. Provisional Patent Application No. 62 / 729,735, filed September 11, 2018, the contents of which are relied upon and incorporated herein by reference in their entirety. This application is also a divisional application of Japanese Patent Application No. 2021-513874, filed September 11, 2019. [Technical field]

[0002] This specification relates generally to glass-based articles suitable for use as cover glasses for electronic devices. [Background technology]

[0003] Due to their portability, portable devices such as smartphones, tablets, portable media players, personal computers, and cameras are particularly vulnerable to accidental drops onto hard surfaces such as the ground. These devices typically incorporate a cover glass that can be damaged when struck against a hard surface. In many of these devices, the cover glass acts as a display cover and may incorporate touch functionality, which can adversely affect the use of the device if the cover glass is damaged.

[0004] There are two primary failure modes for cover glass when the associated mobile device is dropped onto a hard surface. One mode is bending fracture, which is caused by the glass bending when the device is subjected to dynamic loading from impact with a hard surface. The other mode is abrupt contact failure caused by the introduction of damage to the glass surface. Impact of glass with rough, hard surfaces such as asphalt, granite, etc. can result in sharp indentations in the glass surface. These indentations become breakage points in the glass surface from which cracks can initiate and propagate.

[0005] Ion-exchange techniques, which involve inducing compressive stresses in the glass surface, can render the glass more resistant to bending fracture. However, ion-exchanged glass is still vulnerable to dynamic sharp contact due to high stress concentrations caused by localized depressions in the glass resulting from the sudden contact. In addition, ion-exchanged glass articles can exhibit undesirable fracture modes resulting in multiple shards and / or energized shards due to the energy stored in the glass.

[0006] Glass manufacturers and handheld device manufacturers have been continuously working to improve the resistance of handheld devices to sudden contact failure. Solutions range from coating 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 with a hard surface.

[0007] It is also desirable for mobile devices to be as thin as possible. Thus, in addition to strength, it is also desirable for the glass used as the cover glass of a mobile device to be as thin as possible. Thus, 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 can produce thin glass articles, such as thin glass sheets. Summary of the Invention [Problem to be solved by the invention]

[0008] Thus, there is a need for a glass that can be strengthened, such as by ion exchange, and that does not shatter into multiple shards when broken. [Means for solving the problem]

[0009] According to aspect (1), a glass-based article is provided. The glass-based article includes a first surface; a second surface; and a stress profile having a first compressive region extending from the first surface to a first depth of compression DOC1, a second compressive region extending from the second surface to a second depth of compression DOC2, and a tensile region extending from DOC1 to DOC2. The tensile region has a stress profile of at least 1.31 MPa √(m) and at least 1.8 K. IC Tensile stress coefficient K less than T It has K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article.

[0010] According to aspect (2), K T is 1.41 MPa·√(m) or more.

[0011] According to aspect (3), K T is 2.0 MPa·√(m) or more.

[0012] According to aspect (4), K T is 1.781K IC There is provided a glass-based article according to any one of aspects (1) to (3), which is as follows:

[0013] According to aspect (5), K IC The glass-based article according to any one of aspects (1) to (4) is provided, wherein the modulus of elasticity is 0.67 MPa·√(m) or more.

[0014] According to aspect (6), K IC The glass-based article according to any one of aspects (1) to (5) is provided, wherein the modulus of elasticity is 1.3 MPa·√(m) or more.

[0015] According to an aspect (7), there is provided a glass-based article according to any one of aspects (1) to (6), comprising an alkali aluminosilicate.

[0016] According to an embodiment (8), there is provided the glass-based article according to any one of embodiments (1) to (7), wherein DOC1 = DOC2, measured from the first and second surfaces, respectively.

[0017] According to an aspect (9), there is provided the glass-based article according to any one of aspects (1) to (8), wherein the glass-based article is non-brittle.

[0018] According to aspect (10), there is provided a consumer electronic product. The consumer electronic product includes a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component comprising at least a controller, a memory, and a display, the display being at or adjacent to the front of the housing; and a cover substrate disposed over the display. A portion of at least one of the housing or the cover substrate comprises the glass-based article of any of aspects (1) to (9).

[0019] According to an embodiment (11), a glass-based article is provided. The glass-based article includes a surface; and a stress profile having a compressive region and a tensile region extending from the surface to a depth of compression DOC. The tensile region has a stress profile of 1.31 MPa √(m) or more and K T 限界 The tensile stress coefficient K T where K T 限界 is defined by the following formula:

[0020]

number

[0021] In the formula, K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article, and t is the thickness of the glass-based article.

[0022] According to aspect (12), K T is 1.41 MPa·√(m) or greater.

[0023] According to aspect (13), K T is 2.0 MPa·√(m) or more.

[0024] According to an embodiment (14), there is provided the glass-based article according to any one of embodiments (11) to (13), having a DOC / t of greater than 0.12.

[0025] According to an embodiment (15), there is provided the glass-based article according to any one of embodiments (11) to (14), having a DOC / t of greater than 0.18.

[0026] According to aspect (16), K IC The glass-based article according to any one of aspects (11) to (15) is provided, wherein the modulus of elasticity is 0.67 MPa·√(m) or more.

[0027] According to aspect (17), K IC The glass-based article according to any one of aspects (11) to (16) is provided, wherein the modulus of elasticity is 1.3 MPa·√(m) or more.

[0028] According to an embodiment (18), there is provided the glass-based article according to any one of embodiments (11) to (17), comprising an alkali aluminosilicate.

[0029] According to an aspect (19), there is provided the glass-based article according to any of aspects (11) to (18), wherein the glass-based article is non-brittle.

[0030] According to aspect (20), there is provided a consumer electronic product. The consumer electronic product includes a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component comprising at least a controller, a memory, and a display, the display being at or adjacent to the front of the housing; and a cover substrate disposed over the display. A portion of at least one of the housing or the cover substrate comprises the glass-based article of any of aspects (11) to (19).

[0031] According to aspect (21), a glass-based article is provided. The glass-based article includes a first surface; a second surface; and a stress profile having a first compressive region extending from the first surface to a first depth of compression DOC1, a second compressive region extending from the second surface to a second depth of compression DOC2, and a tensile region extending from DOC1 to DOC2. The tensile region has a stress profile of at least 1.31 MPa √(m) and a K T 限界 The tensile stress coefficient K T where K T 限界 is defined by the following formula:

[0032]

number

[0033] In the formula, K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article, t is the thickness of the glass-based article, and DOC1 and DOC2 are measured from the first surface.

[0034] According to aspect (22), K T is 1.41 MPa·√(m) or greater.

[0035] According to aspect (23), K T is 2.0 MPa·√(m) or more.

[0036] According to aspect (24), K T 0.95K T 限界 There is provided a glass-based article according to any one of aspects (21) to (23), wherein:

[0037] According to aspect (25), K T 0.85K T 限界There is provided a glass-based article according to any one of aspects (21) to (24), wherein:

[0038] According to aspect (26), K IC The glass-based article of any of aspects (21) to (25) is provided, wherein the modulus of elasticity is 0.67 MPa·√(m) or greater.

[0039] According to aspect (27), K IC is 1.3 MPa·√(m) or greater.

[0040] According to an aspect (28), there is provided the glass-based article according to any one of aspects (21) to (27), comprising an alkali aluminosilicate.

[0041] According to an embodiment (29), there is provided the glass-based article according to any one of embodiments (21) to (28), wherein DOC1=t-DOC2.

[0042] According to an aspect (30), there is provided the glass-based article of any of aspects (21) to (29), wherein the glass-based article is non-brittle.

[0043] According to aspect (31), there is provided a consumer electronic product. The consumer electronic product includes a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component comprising at least a controller, a memory, and a display, the display being at or adjacent to the front of the housing; and a cover substrate disposed over the display. A portion of at least one of the housing or the cover substrate comprises the glass-based article of any of aspects (21) to (30).

[0044] According to an embodiment (32), a glass-based article is provided. The glass-based article includes a surface; and a stress profile having a compressive region and a tensile region extending from the surface to a depth of compression DOC. The compressive region has a compressive stress coefficient K CSThe tensile region has a tensile stress coefficient K of 1.31 MPa √(m) or more. T It has 、 and:

[0045]

number

[0046] where K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article.

[0047] According to aspect (33),

[0048]

number

[0049] The glass-based article of claim 32 is provided,

[0050] According to aspect (34),

[0051]

number

[0052] The glass-based article according to aspect (32) or (33) is provided,

[0053] According to aspect (35), K T is 1.41 MPa·√(m) or greater.

[0054] According to aspect (36), K T The glass-based article of any of aspects (32) to (35) is provided, wherein the modulus of elasticity is 2.0 MPa·√(m) or greater.

[0055] According to an aspect (37), there is provided the glass-based article according to any one of aspects (32) to (36), comprising an alkali aluminosilicate.

[0056] According to an aspect (38), there is provided the glass-based article of any of aspects (32) to (37), wherein the glass-based article is non-brittle.

[0057] According to aspect (39), there is provided a consumer electronics product. The consumer electronics product includes a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component comprising at least a controller, a memory, and a display, the display being at or adjacent to the front of the housing; and a cover substrate disposed over the display. A portion of at least one of the housing or the cover substrate comprises the glass-based article of any of aspects (32) to (38).

[0058] 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 may be learned by practicing the embodiments described herein, including the following detailed description, the claims, and the accompanying drawings.

[0059] 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 in 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]

[0060] [Figure 1] Diagram showing non-vulnerable samples after vulnerability testing [Diagram 2] A diagram showing the vulnerability samples after vulnerability testing [Diagram 3] Schematic diagram of the specimen and its cross section used to determine fracture toughness KIC [Figure 4] 1 is a schematic diagram of a cross section of a glass-based article having a compressive stress layer on a surface thereof according to embodiments disclosed and described herein. [Diagram 5] Plot of branching per crack branch as a function of tensile stress coefficient KT for various compositions [Figure 6] Plot of the fragility limit of KT for the compositions in Figure 5 as a function of fracture toughness KIC [Figure 7] Plot of number of fragments after fracture as a function of KT for composition 2 samples with various thicknesses and ion exchange treatments [Figure 8] Plot of maximum non-fragile KT squared as a function of DOC / t for composition 2 samples [Figure 9] Plot of the data from Figure 8 as a function of BTZ / t [Figure 10] Plot of data from Figures 7 and 8 after combining with data on integral of squared stress in the compressive stress region (KT and KCS are the tensile and compressive stress coefficients, respectively). [Figure 11] Plot of data from Figures 7 and 8 after combining with data on integral of squared stress in the compressive stress region (KTn and KCSn are the tensile and compressive stress coefficients normalized to fracture toughness, respectively). [Figure 12A] FIG. 1 is a plan view of an exemplary electronic device incorporating any of the glass-based articles disclosed herein. [Figure 12B] FIG. 12B is a perspective view of the exemplary electronic device of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] Reference will now be made in detail to glass-based articles according to various embodiments. As used herein, "glass-based" refers to an article that includes a glass, such as a glass or glass-ceramic composition, where the glass-ceramic includes one or more crystalline phases and a residual glass phase. In general, a "glass-based substrate" refers to the article prior to ion exchange, and a "glass-based article" refers to the article that has been ion-exchanged.

[0062] The glass-based articles exhibit improved drop performance while at the same time not exhibiting fracture modes that produce multiple fragments. This quality makes them particularly suitable for use in electronic devices, especially portable electronic devices, which may be exposed to conditions during use that would cause the glass-based article to fracture. The glass-based articles include a compressive stress layer that extends from the surface of the glass-based article to the depth of compression.

[0063] The selection of a glass-based article for use in an electronic device can take into account the overall influence of a particular combination of properties resulting from the glass composition and the stress profile of the glass-based article. Stated differently, the behavior of an ion-exchanged glass-based article can be attributed to factors related to the composition of the glass-based substrate that is subjected to ion exchange to form the glass-based article, and factors resulting from the stress profile produced by the ion exchange process.

[0064] As glass-based articles are increasingly chemically strengthened, such as by ion exchange, in the pursuit of ever-increasing fracture resistance, there is an increased risk that the glass-based article will exhibit an undesirable fracture mode that produces multiple fragments, which may be referred to as brittleness. Previously, the criteria for avoiding brittleness in tempered glass were based on the maximum central tension (CT), stored strain energy (SSE), or tensile stress modulus (K T) to determine the fragility of glass-based articles. However, these limits are not universally applicable. Described herein are new criteria for determining the fragility of glass-based articles, particularly those that have higher fracture toughness and / or depth of compression relative to their thickness than previous glass-based articles. These criteria are based on the relationship between the properties of the glass-based substrate utilized to form the glass-based article, such as fracture toughness and Young's modulus, and the properties of the stress profile, such as depth of compression and tensile stress modulus. Additionally, these criteria can be applied in some embodiments without destroying the glass-based article, allowing for use in quality control applications.

[0065] As utilized herein, a glass-based article is considered "non-brittle" if it exhibits at least one of the following in the test area as a result of the brittle test: (1) no more than four fragments with a maximum dimension of at least 1 mm, and / or (2) no more than 1.5 branches per crack branch. The fragments, branches, and crack branches are counted based on a 5 cm x 5 cm square centered on the impact point. Thus, a glass is considered non-brittle if it meets one or both of tests (1) and (2) for a 5 cm x 5 cm square centered on the impact point where breakage occurs, according to the procedure described below. In the brittle test, an impact probe is contacted with the glass, and the depth to which the impact probe extends into the glass is increased with successive contact iterations. The stepwise increase in the depth of the impact probe allows the flaws created by the impact probe to reach the tension area while preventing the application of excessive external forces that would prevent accurate determination of the brittle behavior of the glass. The glass-based article is placed on a steel surface, such as the MVN precision vertical stage available from Newport Corporation. The impact probe is a 40 g stylus with a tungsten carbide tip (available from Fisher Scientific Industries under the trademark TOSCO® and manufacturer identification number #13-378 with a 60 degree cone-sphere tip) connected to a clamp on a gear drive mechanism that moves the stylus up and down. In one embodiment, the depth of the impact probe in the glass can be increased by about 5 μm with each iteration, and the impact probe is released from contact with the glass between each iteration. The test area is a 5 cm×5 cm square centered on the impact point. FIG. 1 shows the results of the non-brittle test. As shown in FIG. 1, the test area is a square centered on the impact point 135, with the side length d of the square being 5 cm. The non-brittle sample shown in FIG. 1 includes three fragments 142, as well as two crack branches 140 and a single branch 150. Thus, the non-brittle specimens shown in Figure 1 contain fewer than four fragments with a maximum dimension of at least 1 mm and have a number of branches less than or equal to the number of crack branches (0.5 branches per crack branch).As utilized herein, the crack branch initiates at the point of impact, and a fragment is considered to be within the test area if any portion of the fragment extends within the test area. Coatings, adhesive layers, and the like may be used in combination with the strengthened glass-based articles described herein, however, such external restraints are not used to determine the fragility or fragility behavior of the glass-based article. In some embodiments, a film that does not affect the fracture behavior of the glass-based article may be applied to the glass-based article prior to fragility testing to prevent the release of fragments from the glass-based article and to enhance the safety of the person conducting the test.

[0066] A brittle sample is shown in FIG. 2. The brittle sample includes six fragments 142 with a maximum dimension of at least 1 mm. The sample shown in FIG. 2 includes two crack branches 140 and four branches 150 (two branches per crack branch), generating more branches than crack branches. Thus, the sample shown in FIG. 2 does not exhibit less than four fragments or less than 1.5 branches per crack branch. Although FIGS. 1 and 2 include two crack branches 140 originating at the impact point 135, it should be understood that more than two crack branches may originate at the impact point, such as three or more crack branches.

[0067] In the brittleness test described herein, an impact is delivered to the surface of the glass article with just enough force to release the internally stored energy present within the strengthened glass article, i.e., the point impact force is sufficient to generate at least one new crack at the surface of the strengthened glass sheet and propagate the crack through the compressive stress CS region (i.e., through the depth of compression) into the central tensile region.

[0068] Thus, the glass-based articles described herein are "non-brittle" (i.e., do not exhibit the brittle behavior described above when impacted by a sharp object).

[0069] Previously, the most widely applicable empirical fragility limits for chemically strengthened glass-based articles were based on the tensile strain energy stored in the tension region of the strengthened glass-based article. As utilized herein, the term tensile strain energy (TSE) refers to the energy stored in the tension zone of a unit area (one square meter) of a sheet of a glass-based article. The TSE limit is approximately 18 J / m 2 It has been observed that the thermal conductivity of the glass-based article is about 9 J / m in each of two mutually orthogonal dimensions, x and y, parallel to the surface of the glass-based article. 2 A budget of is allowed. The TSE per dimension (x and y) is given by:

[0070]

number

[0071] where E is Young's modulus, ν is Poisson's ratio, DOC1 is the first depth of compression, DOC2 is the second depth of compression, z is the position in the thickness direction, and σ x and σ y are the components of the stress tensor in a plane parallel to the surface of the glass-based article in the directions of corresponding x- and y-axes that define the two-dimensional space of the glass-based article. Within the region of the glass-based article sheet, these two components of in-plane stress are approximately equal, and therefore each carries approximately the same strain energy, resulting in a total tensile strain energy fragility limit of 18 J / m 2 is a single component of the in-plane stress (e.g., σ x ) about 9J / m 2 can be replaced by the limit of

[0072] In a related approach, the brittle limit is given by K, which has units of stress intensity factor (e.g., MPa√m). T As used herein, the quantity K T is the tensile stress coefficient given by:

[0073]

number

[0074] where σ is represented by one of the in-plane components (since the in-plane components are assumed to be equal) and z is the position through the thickness. K in MPa√m T To obtain the value of , the stress values ​​under integration must be in MPa and the thickness position scale z must be in m.

[0075] In the specification of U.S. Pat. No. 9,604,876 (B2), in Table 2, T Specimens with a K of 1.4 MPa√m or more generate many fragments upon fracture. T It is disclosed that samples with a tensile strength of 1.3 MPa√m or less do not undergo excessive fragmentation. At the same time, the maximum central tension (CT) in the tensile zone was 74 MPa and 72 MPa for the highly fragmented examples, and did not exceed 68 MPa for all other examples. It should be noted that in most cases, typical of chemical strengthening, the CT is in the middle of the thickness of the glass sheet. These examples are T Higher fragmentation is reported with increasing values ​​of K T This is in agreement with the publication by E. Bouyne and O. Gaume, “Fragmentation of thin chemically tempered glass plates”, Glass Technology 2002, 43C, pp. 300-302, which showed that all samples with a modulus of 1.4 MPa√m or more produced numerous fragments (at least 5 in a 5 cm × 5 cm square area).

[0076] As used herein, the term "brittle limit" refers to the boundary between the condition at which a glass-based article exhibits excessive fragmentation (brittle) and the condition at which the glass-based article does not exhibit excessive fragmentation (non-brittle). The condition at the brittle limit is characterized by the tensile strain energy TSE or tensile stress modulus K, which have been shown to correlate with the degree of fragmentation. T The total tensile strain energy (taking into account both the x and y dimensions of strain) can be expressed as the tensile strain coefficient K measured for a single stress component (x or y) by the following equation:T Related to:

[0077]

number

[0078] If the stress components along x and y are significantly different and can be measured, the tensile strain energy stored in each dimension can be calculated separately as follows:

[0079]

number

[0080] The TSE and K T The fragility limit depends, at least in part, on material properties, such as the fracture toughness, of the glass-based substrate utilized to form the glass-based article, and on stress profile parameters, such as the ratio of compression depth to thickness of the glass-based article. Stated differently, the fragility limit described herein takes into account fracture toughness that has not been considered in previous fragility determinations.

[0081] Generally, the properties described herein, which refer to glasses having compositions comparable to those of the center of the glass-based article, depend on the composition of the glass-based substrate that was ion-exchanged to form the glass-based article. In practice, the composition of the center of a glass-based article can be measured by techniques known in the art, and the fracture toughness (K) of a manufactured glass composition having the measured composition can be determined by a method known in the art. IC ) and Young's modulus (E) values ​​can be measured. In addition, the center of the glass-based article is not or only minimally affected by the ion exchange process, and therefore the composition of the center of the glass-based article is substantially the same or the same as the composition of the glass-based substrate. For this reason, the K of a glass composition having this composition in the center of the glass-based article, among others, can be measured. IC The values ​​of and E can be determined by measuring these properties of the glass-based substrate before the ion-exchange treatment.

[0082] The following describes properties of the glass-based article that can be achieved by modifying the amounts of the components of the glass-based composition or the stress profile of the glass-based article.

[0083] The compositions utilized to form glass-based articles according to embodiments have high fracture toughness (K IC In some embodiments, the composition utilized in forming the glass-based article has a viscosity of 0.67 MPa√m or more, e.g., 0.68 MPa√m or more, 0.69 MPa√m or more, 0.70 MPa√m or more, 0.71 MPa√m or more, 0.72 MPa√m or more, 0.73 MPa√m or more, 0.74 MPa√m or more, 0.75 MPa√m or more, 0.76 MPa√m or more, 0.77 MPa√m or more, 0.78 MPa√m or more, 0.79 MPa√m or more 0.5 More than 0.80MPa m 0.5or more, 0.81MPa√m or more, 0.82MPa√m or more, 0.83MPa√m or more, 0.84MPa√m or more, 0.86MPa√m or more, 0.87MPa√m or more, 0.88MPa√m or more, 0.89MPa√m or more, 0.90MPa√m or more, 0.91MPa√m or more, 0.92MPa√m or more, 0.93MPa√m or more, 0.94MPa√m or more, 0.95MPa√m or more, 0.96MPa√m or more, 0.97MPa√m or more, 0.98MPa√m or more, 0.99MPa√m or more, 1.00MPa√m or more, 1.01MPa√m or more, 1.02MPa√m or more, 1.03MPa√m or more, 1.04MPa√m or more, 1.05MPa√m or more, 1.06MPa√m or more, 1.07MPa√m or more, 1.08MPa a√m or more, 1.09MPa√m or more, 1.10MPa√m or more, 1.11MPa√m or more, 1.12MPa√m or more, 1.13MPa√m or more, 1.14MPa√m or more, 1.15MPa√m or more, 1.16MPa√m or more, 1.17MPa√m or more, 1.18MPa√m or more, 1.19MPa√m or more, 1.20MPa√m or more, 1.21MPa√m or more, 1.22MPa√m or more, 1.23MPa√m or more, 1.24MPa√m or more, 1.25MPa√m or more, 1.26MPa√m or more, 1.27MPa√m or more, 1.28MPa√m or more, 1.29MPa√m or more, 1.30MPa√m or more, 1.31MPa√m or more, 1.32MPa√m or more, 1.33MPa√m or more, or 1.34MPa√m or more, K ICIn an embodiment, the composition utilized to form the glass-based article has a modulus of 0.67 MPa√m or more and 1.34 MPa√m or less, for example, 0.68 MPa√m or more and 1.33 MPa√m or less, 0.70 MPa√m or more and 1.32 MPa√m or less, 0.72 MPa√m or more and 1.31 MPa√m or less, 0.74 MPa√m or more and 1.30 MPa√m or less, 0.76 MPa√m or more and 1.29 MPa√m or less, 0.78 MPa√m or more and 1.28 MPa√m or less, for example ... a√m or less, 0.80MPa√m or more and 1.27MPa√m or less, 0.82MPa√m or more and 1.26MPa√m or less, 0.8MPa√m or more and 1.25MPa√m or less, 0.85MPa√m or more and 1.24MPa√ m or less, 0.86MPa√m or more and 1.23MPa√m or less, 0.87MPa√m or more and 1.22MPa√m or less, 0.88MPa√m or more and 1.21MPa√m or less, 0.89MPa√m or more and 1.20MPa√m 0.90MPa√m or more and 1.19MPa√m or less, 0.91MPa√m or more and 1.18MPa√m or less, 0.92MPa√m or more and 1.17MPa√m or less, 0.93MPa√m or more and 1.16MPa√m or less Lower, 0.94MPa√m or more and 1.15MPa√m or less, 0.95MPa√m or more and 1.14MPa√m or less, 0.96MPa√m or more and 1.13MPa√m or less, 0.97MPa√m or more and 1.12MPa√m or less , 0.98MPa√m or more and 1.11MPa√m or less, 0.99MPa√m or more and 1.10MPa√m or less, 1.00MPa√m or more and 1.09MPa√m or less, 1.01MPa√m or more and 1.08MPa√m or less, 1.02MPa√m or more and 1.07MPa√m or less, 1.03MPa√m or more and 1.06MPa√m or less, 1.04MPa√m or more and 1.05MPa√m or less, and all ranges and subranges therebetween. IC In some embodiments, the compositions utilized in forming the glass-based articles have a K value of 0.90 MPa√m or greater. IC In some embodiments, the compositions utilized in forming the glass-based articles have a K value of 1.5 MPa√m or less. IC Indicates the value.

[0084] As used herein, fracture toughness K IC is measured by the double cantilever beam (DCB) method. ICThe values ​​were measured on glass-based substrates prior to ion-exchange to form glass-based articles. The geometry of the DCB specimens is shown in Figure 3, with the critical parameters being the crack length a, the applied load P, the cross-sectional dimensions w and 2h, and the thickness b of the crack induction groove. The specimens were cut into rectangles with width 2h = 1.25 cm and thickness w = 0.3 mm to 1 mm, with the total length of the specimens varying from 5 cm to 10 cm, although this is not a critical dimension. Holes were drilled at both ends with a diamond drill to provide a means for attaching the specimen to a specimen holder and load. The crack "induction groove" was cut off the length of the specimen on both flat faces using a wafer dicing saw with a diamond blade, leaving a "web" of material approximately half the total thickness of the plate at a height of 180 μm corresponding to the thickness of the blade (dimension b in Figure 3). The high precision dimensional tolerances of the dicing saw allow for minimal variation between specimens. A dicing saw was also used to cut the initial crack of a = 15 mm. This final action resulted in the creation of a very thin wedge of material near the crack tip (due to the curvature of the blade), making it easier for cracks to initiate in the specimen. The specimen was mounted in a metal specimen holder with a steel wire in the hole at the bottom of the specimen. To keep the specimen horizontal under low load conditions, it was also supported on the other side. A spring in series with a load cell (FUTEK, LSB200) was hooked in the top hole and extended, and the load was gradually applied using a rope and a precision slide. The crack was monitored using a microscope with a resolution of 510 μm, connected to a digital camera and computer. The applied stress K P was calculated using the following formula:

[0085]

number

[0086] For each specimen, a crack was first initiated at the tip of the web, and then the starter crack was carefully grown subcritically until the ratio of dimensions a / h exceeded 1.5 (this is required for the above formula to accurately calculate the stress intensity). At this point, the length of the crack, a, 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 wicked up along the entire length of the groove by capillary forces, fixing the crack from moving until the fracture toughness was reached. The load was then increased until specimen failure occurred, and the critical stress intensity, K, was calculated from the fracture load and specimen dimensions. IC We calculated the K P Due to the measurement method, K IC is equivalent to

[0087] The Young's modulus (E) of the glass composition used to form the glass-based article is negatively correlated with the drop performance of the glass-based article. In an embodiment, the composition used to form the glass-based article has a Young's modulus of 60 GPa to 120 GPa, for example, 62 GPa to 115 GPa, 64 GPa to 113 GPa, 66 GPa to 112 GPa, 68 GPa to 111 GPa, 70 GPa to 110 GPa, 72 GPa to 109 GPa, 74 GPa to 108 GPa, 76 GPa to 107 GPa, 78 GPa to 106 GPa, 80 GPa The composition may exhibit a Young's modulus (E) of 80 GPa to 120 GPa, 82 GPa to 104 GPa, 84 GPa to 103 GPa, 86 GPa to 102 GPa, 88 GPa to 101 GPa, 90 GPa to 100 GPa, 91 GPa to 99 GPa, 92 GPa to 98 GPa, 93 GPa to 97 GPa, 94 GPa to 96 GPa, or equal to 95 GPa, as well as all ranges and subranges therebetween. In an embodiment, the composition utilized to form the glass-based article exhibits a Young's modulus (E) of 80 GPa to 120 GPa. In some embodiments, the composition utilized to form the glass-based article may have a Young's modulus (E) of 120 MPa or greater. The Young's Modulus values ​​listed in this disclosure refer to values ​​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."

[0088] The glass-based article can have any suitable thickness. In embodiments, the glass-based article can have a thickness (t) of from 0.2 mm to 2.0 mm, for example, from 0.3 mm to 1.0 mm, from 0.4 mm to 0.9 mm, from 0.5 mm to 0.8 mm, from 0.6 mm to 0.7 mm, and all ranges and subranges therebetween.

[0089] The Poisson's ratio values ​​set forth in this disclosure refer to values ​​measured in accordance with 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."

[0090] As described above, glass-based articles can be strengthened, such as by ion exchange, to make the glass damage-resistant for applications such as, but not limited to, articles for display covers or electronic device housings. With reference to FIG. 4, the glass-based article has a first region under compressive stress (e.g., first and second compressive layers 120, 122 in FIG. 4) that extends 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. 4) that extends 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 changes from compression to tension within the glass-based article. At the DOC, the stress transitions from positive (compressive) stress to negative (tensile) stress, thus exhibiting a zero stress value.

[0091] 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, CS=|CS|, as described herein. The compressive stress (CS) may be at or near a maximum value at the surface of the glass-based article, and CS varies with distance d from the surface according to a function. Referring again to FIG. 4, a first segment 120 extends from the first surface 110 to a depth d1, and a second segment 122 extends from the second surface 112 to a depth d2. Together, these segments define the compression or CS of the glass-based article 100. The compressive stresses of both major surfaces (110, 112 in FIG. 4) are balanced by tension accumulated in the central region (130) of the glass. In some embodiments, d1=d2, measured from the first surface 110 and the second surface 112, respectively. For convenience, when a single DOC is referenced herein, the stress profile is presumed to be symmetric such that DOC1=DOC2, measured from the first surface 110 and the second surface 112, respectively.

[0092] The stress profiles of the glass-based articles were measured with different methods based on the composition of the glass-based substrate utilized to form the glass-based article. The method utilized for the sodium aluminosilicate glasses was different than the method utilized for the lithium aluminosilicate glasses.

[0093] Stress profiles for glass-based articles formed from sodium aluminosilicate (SAS) glass-based substrates toughened by ion exchange of potassium for sodium were measured from TM and TE refractive index profiles obtained using inverse WKB profile extraction applied to the measured effective refractive indices of the TM and TE guided modes using a prism coupling technique at either 633 nm or 595 nm. Stress profiles were extracted in the range of K penetration by subtracting the two refractive index profiles and dividing by the stress-optical coefficient. In the tensile zone, the profile was then extracted from the DOC to a depth d where the profile flattens out. cIt starts with a parabolic shape up to the thickness d, then a constant tension equal to the profile CT passes through the middle thickness and to the same depth d on the other side. c It was assumed that the extension was up to 1.15 DOL for composition 2, which does not contain K in the base glass. K , and 1.4·DOL for compositions 1 and 4, which contain significant amounts of K in the base glass before ion exchange. K Depth d equal to c was chosen based on empirical observations, where DOL K refers to the "depth of layer-potassium" or depth of potassium penetration as a result of the ion exchange process, determined for a one-step ion exchange profile by a prism-coupled stress meter FSM-6000 manufactured by Orihara Seisakusho Co., Ltd., Japan. In this assumption, the thickness integral of the tension in the tensile zone is given by thickness t, DOC, and depth d c is known, it is a simple function of CT, and after equating this integral with the integral of the compressive stresses measured on either side of the tension zone (to ensure force balance), the central tension CT is found. Once the CT value is known, K can be determined from the assumed shape of the tension zone. T The values ​​and TSE values ​​are obtained.

[0094] A stress profile for a glass-based article formed from a lithium aluminosilicate (LAS) glass based substrate, the stress profile having a deep component produced by the exchange of Na with Li and a shallow component obtained by the exchange of K with Li or Na and Li ... T The values ​​of , were obtained by combining measurements of CT using a properly calibrated scattered light polarimeter (SCALP) manufactured by GlassStress and measurements of DOC using another scattered light polarimeter (SLP-1000) manufactured by Orihara Seisakusho. When a K-rich highly compressed layer is present at the surface, the surface compressive stress CS, the layer spike depth DOL sp , and DOL using prism bond stress measurements sp Knee stress in CS K Measurements of were also used.

[0095] The prism coupling measurements utilized the Refractive Near Field (RNF) method. The maximum CT value provided by SCALP is used in the RNF method. In particular, the stress profile measured by RNF is force balanced and calibrated to the maximum CT value provided by the SCALP measurement. The RNF method is described in U.S. Pat. No. 8,854,623, entitled "Systems and methods for measuring a profile characteristic of a glass sample," which is incorporated herein by reference in its entirety. In particular, the RNF method includes placing a glass article adjacent to a reference block, generating a polarization-switched light beam that is switched between orthogonal polarizations at a rate of 1 Hz to 50 Hz, measuring the amount of power in the polarization-switched light beam, and generating a polarization-switched reference signal, where the amount of power measured in each of the orthogonal polarizations is within 50% of each other. The method further includes transmitting the polarization-switched light beam through the glass sample and the reference block at various depths into the glass sample, and then relaying the transmitted polarization-switched light beam using relay optics to a signal photodetector that generates a polarization-switched detector signal. The method also includes dividing the detector signal by the reference signal to form a normalized detector signal, and determining a profile characteristic of the glass sample from the normalized detector signal.

[0096] To force balance the stress profile measured by RNF, the stress profile is shifted vertically until the sum of the stress depth areas of the compression regions equals the area of ​​the tension region. If the stress profile is symmetric, accuracy is improved by making the area of ​​the compression region closest to the reference block equal to half the area of ​​the tensile region also closest to the reference block. After force balancing, the CT of the force balanced RNF profile is divided by the CT of SCALP to obtain a calibration (scale) factor. The force balanced profile is then divided by the calibration factor to produce a force balanced and calibrated stress profile.

[0097] The contribution of the surface spike of K to CT is calculated as follows:

[0098]

number

[0099] where t is the thickness of the glass-based article. The spike refers to the steep portion of the stress profile near the surface that is rich in potassium and exhibits high compression. In an embodiment, the DOL sp is a graph showing the DOL of a glass-based article formed from a lithium-containing glass-based substrate and ion-exchanged in a potassium-containing salt bath. K The contribution of the deep component of the stress profile produced by ion-exchanging Na with Li is calculated as: CT 深さ =CT-CT sp For the example of interest using LAS glass, the Na diffusion depth is comparable to half the thickness of the glass sheet, and the shape of the stress profile in the tensile zone can be reasonably approximated as the absolute value of a power law shape, with the power factor p in the range of 1.5 to 3 (p = 2 corresponds to a parabolic shape). Under that assumption, p, CT 深さ Given the total CT measured by SCALP, the exact solution for the DOC / t ratio is:

[0100]

number

[0101] Measure CT and DOC as described above, measure thickness with a micrometer, and measure CT 深さ After calculating DOC / t, the power coefficient p was varied until the measured DOC / t value matched the ratio calculated based on the above formula. This fixed p value allows the tensile region, together with CT and DOC, to be completely determined.

[0102] By assigning a value z0 to the distance from the mid-thickness of the glass-based article to the point where compression becomes tension, we get: z0=0.5t-DOC Next, the tensile stress coefficient (K T ) and TSE are calculated as a function of the power coefficient p as follows:

[0103]

number

[0104] To reduce errors caused by laser speckle and other noise sources, the CT and DOC values ​​for each sample were averaged over at least 20 measurements, each resulting from separate scans acquired with a slight shift in the sample position on the instrument. The SLP-1000 sample surface localization was calibrated by measuring a SAS glass sample whose DOC was accurately determined by the IWKB-based stress profile extraction method.

[0105] Surface stress measurements rely on accurate measurement of the stress optical coefficient (SOC), which is related to the birefringence of the glass. SOC is measured in accordance with Procedure C (Glass Disk Method) described in ASTM Standard C770-16, entitled "Standard Test Method for Measurement of Glass Stress-Optical Coefficient," the entire contents of which are incorporated herein by reference.

[0106] In some embodiments, the tensile stress coefficient K T The fragility limit of a glass-based article with respect to the tensile strain energy TSE is not constant and depends on the fracture toughness K IC FIG. 5 shows the tensile stress coefficient K for three different SAS glass compositions with different fracture toughness. TFigure 5 shows the average number of branches per crack branch as a function of K. The number of crack branches was typically 2 or 3, each originating from a fracture origin location in the center of a 5 cm x 5 cm square glass-based article. In the experiment in Figure 5, the glass-based article had a thickness of 0.8 mm. The compositions in Figure 5 are detailed in Table 1 below. In practice, the brittle limit is T or TSE, above which the glass-based article becomes brittle. For the compositions shown in FIG. 5, the critical value of 1.5 branches per branch is K T This occurred at values ​​of 1.18, 1.215, and 1.29.

[0107] [Table 1]

[0108] Composition 8 is a transparent glass-ceramic. This composition was formed by ceramming a precursor glass.

[0109] As shown in Tables 2 and 3 below, the examples in FIG. 5 were produced using a single-step ion exchange with a bath composed primarily of KNO3 with a small amount of NaNO3. The duration of the ion exchange was varied over the ranges listed in Table 2 to produce samples with various tensile stress moduli and DOC / t. The resulting compressive stress was about 800 MPa for composition 2 and between 750 MPa and 800 MPa for compositions 1 and 3. The DOC ranged from 43 to 60 μm. The steep region of the curves shown in FIG. 5 began at a DOC greater than about 53 μm for compositions 1 and 3 and greater than about 47 μm for composition 2. The DOC / t ratios at the beginning of the steep region of the curves in FIG. 5 fell between 0.058 and 0.070 for all compositions.

[0110] [Table 2]

[0111] IOX conditions 10 and 11 utilized the same salt concentration and the same ion exchange time. However, condition 10 had a higher density packing (0.01 m per kg salt). 2 In condition 11, a glass sample with low density packing (0.005 m per kg salt) was used. 2 Less than 100% glass was used.

[0112] [Table 3-1]

[0113] [Table 3-2]

[0114] [Table 3-3]

[0115] Here, "L" indicates that the sample is on the margin of fragility, "N" indicates that the sample is non-fragile, "Y" indicates that the sample is fragile, and "L / Y" indicates that the sample is marginally or in some cases slightly fragile.

[0116] K of compositions 1, 2, and 3 in FIG. T The brittle limit of the fracture toughness K IC The trend line of the linear fit through the origin is IC Taking into account the experimental standard deviation in the measurements of K, this linear fit provides a good agreement with the experimental results in Fig. 6. T The fragility limit for the fracture toughness K IC t, with a proportionality coefficient of 1.78 when DOC / t is about 0.06. Thus, in some embodiments, the tensile stress coefficient K T exceeds 1.3MPa√m, but the value is 1.78 K ICSuch glass-based articles are provided that are strengthened by a factor of 10 or less, while still remaining non-brittle. T In some embodiments, the tensile stress modulus K T exceeds 1.4MPa√m and is 1.78 K IC not exceed.

[0117] In some embodiments, the glass-based article has a tensile strain modulus, K, of greater than 1.4 MPa√m. T and the tensile strain energy does not exceed the fragility limit with respect to the TSE given by:

[0118]

number

[0119] As an illustration, the fragility limit for the TSE, substituting the values ​​of Poisson's ratio and Young's modulus of composition 2 into the equation, is given by:

[0120]

number

[0121] In the embodiment, the tensile stress coefficient K T The fragility limit of a glass-based article in terms of tensile strain energy TSE depends on the DOC / t ratio, or on the BTZ / t ratio, e.g., the width of the tensile zone divided by the thickness of the sheet. BTZ may alternatively be denoted as DOC2-DOC1. Figure 7 shows experimental data using six different thicknesses of 5 cm x 5 cm squares of glass composition 2 chemically strengthened by prolonged ion exchange in a bath containing about 35% or 37% by weight NaNO3 and 65% or 63% by weight KNO3 at 450°C for an extended period of about 13 to 24.5 hours. The horizontal axis of Figure 7 represents the tensile stress coefficient K obtained from the extraction of the stress profile by the IWKB method. T, where the vertical axis shows the base 2 logarithm of the number of fragments for each fractured sample. Samples that fractured into 5 or more fragments had a logarithm greater than 2 and were considered brittle. All thickness data generally follow the same trend, except for a few outliers. These outliers may be due to false positives, for example, a blunt tip on the fracture tool or slight warping of the sample, which may promote the introduction of external energy (potential or kinetic) into the sample by the fracture tool, respectively. The data shown in Figure 7 are consistent with the coefficient K T This suggests that the critical value of (and correspondingly TSE) is virtually independent of thickness. Furthermore, the K T The critical values ​​of are significantly higher than those of the same composition 2 shown in Figure 5. One major difference between the samples shown in Figure 7 and those shown in Figure 5 is the value of the DOC / t ratio. The sample in Figure 5 was obtained by a relatively shallow ion exchange mainly with KNO3, resulting in a stress profile with a high surface CS of about 800 MPa and a moderate DOC, with the DOC / t ratio of about 0.058 for the part of composition 2 at or near the brittle limit. On the other hand, the sample shown in Figure 7 was strengthened by a very deep ion exchange with a lower surface CS in the range of 240-320 MPa and a significantly higher DOC / t ratio of about 0.13-0.21, resulting in a higher ratio at a smaller thickness and vice versa.

[0122] For each thickness shown in Fig. 7, the tensile strain energy TSE and modulus K T increases. The reported K T In the range of t = 0.4 mm, the DOC / t ratios varied in a relatively narrow range for each thickness, ranging from 0.193 to 0.206 at t = 0.4 mm, 0.161 to 0.179 at t = 0.5 mm, 0.164 to 0.177 at t = 0.55 mm, 0.143 to 0.161 at t = 0.6 mm, 0.138 to 0.167 at t = 0.7 mm, and 0.134 to 0.145 at t = 0.8 mm. The non-brittle samples were at the next highest level of K. TThe following values ​​were observed: 1.379 MPa√m at t = 0.4 mm, 1.37 MPa√m at t = 0.5 mm, 1.375 MPa√m at t = 0.55 mm, 1.36 MPa√m at t = 0.6 mm, 1.37 MPa√m at t = 0.7 mm, and 1.344 MPa√m at t = 0.8 mm. The brittle specimens had the next lowest level of K T was generated for each thickness: 1.313 MPa√m for t = 0.4 mm, 1.24 MPa√m for t = 0.5 mm, 1.368 MPa√m for t = 0.55 mm, 1.376 MPa√m for t = 0.6 mm, 1.334 MPa√m for t = 0.7 mm, and 1.296 MPa√m for t = 0.8 mm. If data points that are above the general trend are assigned as false positives and ignored, the K of weak parts with 8 or more fragments is T The minimum levels are: 1.366 MPa√m at t = 0.4 mm, 1.355 MPa√m at t = 0.5 mm, 1.368 MPa√m at t = 0.55 mm, 1.376 MPa√m at t = 0.6 mm, 1.357 MPa√m at t = 0.7 mm, and 1.343 MPa√m at t = 0.8 mm.

[0123] K in Figures 5 and 7 T The values ​​were squared and plotted in Figure 8 in combination with additional data for the same glass composition 2 obtained at a thickness of 0.4 mm. The additional data include estimates of the brittle limit obtained at very high DOC / t ratios by heat treating brittle samples with large DOC / t ratios above 0.2 until brittle behavior was no longer observed. Such samples were prepared by ion-exchanging in a bath containing 35% NaNO3 and 65% KNO3 at 450 °C for 14.4 to 16.5 h, or in a bath containing 17% NaNO3 and 83% KNO3 at 430 °C for 11.5 h, followed by 450 °C for 1.25 h. The latter samples were very brittle, but approached the brittle limit after 12 h of heat treatment at 400 °C. After heat treatment, the DOC increased to about 0.23t. Samples exchanged in a bath with a high Na content had a low K content after ion-exchange. T The lower values ​​required a shorter heat treatment to return the specimens from the brittle state to the non-brittle state after ion exchange.T 2 The data in Fig. 8 for is well fitted to an empirical linear model, and K T It was possible to determine the exact empirical dependence of the vulnerability limit of (and TSE) on the DOC / t ratio. In particular, for composition 2, the model gives:

[0124]

number

[0125] and:

[0126]

number

[0127] Based on these relationships, the fracture toughness K IC Considering that is 0.767MPa√m, K T The fragility limit, fracture toughness K IC The following empirical general relationship is generated between the DOC / t ratio:

[0128]

number

[0129] In some embodiments, the vulnerability limit K T This empirical general relationship for can be modified by the confidence factor (CF) as follows:

[0130]

number

[0131] Here, the confidence factor (CF) can have a value less than 1, such as in the range of 0.9 to 0.95, and can be used to estimate the K with an accuracy of only a few percent when it is very important to avoid failures due to fragmentation and the precision of the instrument is limited. TBy measuring the key parameters of the stress profile with high precision, K T Where values ​​of can be obtained with an accuracy of 1% or better, a confidence factor (CF) close to 1, such as in the range of 0.95 to 1, may be appropriate.

[0132] TSE and K T Based on this relationship, the following limits can be equally applied to TSE:

[0133]

number

[0134] For composition 2, the Poisson's ratio and Young's modulus have values ​​of 0.22 and 66 GPa, respectively. These values ​​can be used to generate a general TSE limit given by:

[0135]

number

[0136] FIG. 9 shows the data from FIG. 8 as a function of BTZ / t instead of DOC / t. K as a function of BTZ / t for the data for composition 2 T 2 A linear fit of the vulnerability limit was obtained from the following equation:

[0137]

number

[0138] and:

[0139]

number

[0140] Using BTZ, this relationship can be applied to glass-based articles with asymmetric stress profiles, such as those where DOC1 is not equal to DOC2 when measured from the first and second surfaces, respectively. Expressed in terms of fracture toughness, the relationship becomes:

[0141]

number

[0142] The confidence factor (CF) can range from 0.85 to 1 and can be applied in the same way as above.

[0143] The relevant TSE limit is given by:

[0144]

number

[0145] In addition, the compressive stress coefficient K CS is equal to the square root of the integrated compressive stress over the compressive stress regions on either side of the tensile stress region for a single component of stress, x or y, as follows:

[0146]

number

[0147] Or, generally, for any component:

[0148]

number

[0149] For a stress profile with two compressive regions on either side of a central tensile region, extending respectively from a first surface at z=0 to a first compression depth DOC1 and on a second side from a second surface z=t to DOC2, the compressive stress coefficient takes the form:

[0150]

number

[0151] For a symmetric stress profile, where DOC1 = DOC2 when measured from the first and second surfaces, respectively, and with a symmetric stress distribution, the compressive stress modulus is given by:

[0152]

number

[0153] The compressive stress energy value of a glass-based article can be explained as follows:

[0154]

number

[0155] This is K CS,x =K CS,y =K CS can be simplified to:

[0156]

number

[0157] K T The clear increase in the fragility limit for was correlated not only with the DOC / t ratio, but also with the relative magnitudes of the TSE and CSE. Notably, with increasing DOC / t ratio, the TSE constituted a larger proportion of the total strain energy (TSE+CSE) stored in the glass-based article as a result of chemical strengthening. Tables 4 and 5 contain a summary of the data for composition 2 and samples produced at various thicknesses and stress profiles.

[0158] [Table 4]

[0159] [Table 5]

[0160] TSE is K T 2 while CSE is proportional to K CS 2 In the experiment using composition 2, the normalized square coefficient K T and K CS It was determined that the specific sum of does not change substantially regardless of the DOC / t ratio. T 2 and K. CS 2 This indicates that the sum of / 28.5 is constant at the vulnerability limit for the tested range of DOC / t ratios.

[0161]

number

[0162] This includes K ranging from 1.215 MPa√m to 1.418 MPa√m T Examples of non-brittle examples include 1.244 MPa√m, 1.344 MPa√m, 1.35 MPa√m, 1.37 MPa√m, 1.375 MPa√m, and 1.379 MPa√m. Thus, in embodiments, K of 1.2 MPa√m or greater is included. T Also, the glass article having the following properties is satisfied:

[0163]

number

[0164] In an embodiment, the glass-based article has a K of 1.24 MPa√m or more, 1.3 MPa√m or more, 1.34 MPa√m or more, 1.36 MPa√m or more, 1.37 MPa√m or more, 1.4 MPa√m or more, or 1.41 MPa√m or more. T Furthermore, in some embodiments, K T is 2.2K IC , 2.1K IC , 2.0K IC , 1.9K IC、 1.8K IC , or 1.78K IC where K IC is the fracture toughness of the glass or glass composition locally at the point of highest tension (usually the mid-plane of the glass sheet).

[0165] Considering that the fracture toughness of composition 2 is 0.676 MPa√m, the data in Fig. 10 are shown in Fig. 11, where K T 2 and K CS 2 The weighted contribution of is normalized to the square of the fracture toughness. Then, to avoid brittleness:

[0166]

number

[0167] Or:

[0168]

number

[0169] K shown in Figure 11 Tn =K T / K IC and K CSn =K CS / K IC For normalized values ​​where , the condition can be further simplified as follows:

[0170]

number

[0171] In the embodiment, K is 1.31 MPa√m or more. T Also, the glass-based article having the following properties:

[0172]

number

[0173] A more conservative criterion could be used:

[0174]

number

[0175] Or:

[0176]

number

[0177] In an embodiment, K T is 1.2MPa√m or more, for example, 1.24MPa√m or more, 1.3MPa√m or more, 1.31MPa√m or more, 1.34MPa√m or more, 1.36MPa√m or more, 1.37MPa√m or more, 1.4MPa√m or more, 1.41MPa√m or more, 1.43MPa√m or more, 1.44MPa√m or more, 1.45MPa√m or more, 1.46MPa√m or more, 1.47MPa√m or more, 1.48MPa√m or more, 1.4 9 MPa √m or more, 1.50 MPa √m or more, 1.51 MPa √m or more, 1.52 MPa √m or more, 1.53 MPa √m or more, 1.54 MPa √m or more, 1.55 MPa √m or more, 1.56 MPa √m or more, 1.57 MPa √m or more, 1.58 MPa √m or more, 1.59 MPa √m or more, 1.60 MPa √m or more, 1.7 MPa √m or more, 1.8 MPa √m or more, 1.9 MPa √m, or 2 MPa √m or more. T is 2.1K IC Below, 2.0KIC Below, 1.9K IC Below, 1.8K IC Below, 1.78K IC Below, 1.75K IC Below, 1.7K IC Below, 1.65K IC Below or below 2.2K IC not exceed.

[0178] In some embodiments, the CS of the glass-based article is 300 MPa or more and 1300 MPa or less, for example, 325 MPa or more and 1250 MPa or less, 350 MPa or more and 1200 MPa or less, 375 MPa or more and 1150 MPa or less, 400 MPa or more and 1100 MPa or less, 425 MPa or more and 1050 MPa or more, 450 MPa or more and 1000 MPa or less, 475 MPa or more and 975 MPa or less, 500 MPa or more and 950 MPa or less, 525 MPa or more and 925 MPa or more, 550 MPa or more and 900 MPa or more, 575 MPa or more and 875 MPa or less, 600 MPa or more and 850 MPa or less, 625 MPa or more and 825 MPa or more, 650 MPa or more and 800 MPa or more, 675 MPa or more and 775 MPa or more, or 700 MPa or more and 750 MPa or more, and all ranges and subranges therebetween of the aforementioned values. In some embodiments, the CS of the glass-based article is 100 MPa or more.

[0179] DOL K The DOL of each of the first and second compressed layers 120, 122 is typically less than the DOC of the articles described herein. K In another embodiment, the DOL of each of the first and second packed layers 120, 122 is 5 μm or more and 30 μm or less, e.g., 6 μm or more and 25 μm or less, 7 μm or more and 20 μm or less, 8 μm or more and 15 μm or less, or 9 μm or more and 10 μm or less, and all ranges and subranges therebetween. K In yet another embodiment, the DOL of each of the first and second packed layers 120, 122 is 6 μm or more and 30 μm or less, e.g., 10 μm or more and 30 μm or less, 15 μm or more and 30 μm or less, 20 μm or more and 30 μm or less, or 25 μm or more and 30 μm or less, and all ranges and subranges therebetween. Kis from 5 μm to 25 μm, for example, from 5 μm to 20 μm, from 5 μm to 15 μm, or from 5 μm to 10 μm, and all ranges and subranges therebetween.

[0180] In embodiments, the glass-based article may have a maximum CT of 70 MPa or more, e.g., 75 MPa or more, 80 MPa or more, 85 MPa or more, 90 MPa or more, 95 MPa or more, 100 MPa or more, 105 MPa or more, 110 MPa or more, 110 MPa or more, 120 MPa or more, 130 MPa or more, 140 MPa or more, 150 MPa or more, 155 MPa or more, or more. In some embodiments, the glass-based article may have a maximum CT of 400 MPa or less, e.g., 350 MPa or less, 300 MPa or less, 250 MPa or less, 190 MPa or less, 180 MPa or less, 170 MPa or less, 160 MPa or less, 150 MPa or less, 140 MPa or less, 130 MPa or less, 120 MPa or less, 110 MPa, or 100 MPa or less. It should be understood that in embodiments, any of the above ranges can be combined with any other range. However, in other embodiments, the glass article may have a maximum CT of from 70 MPa to 400 MPa, such as from 90 MPa to 350 MPa, from 110 MPa to 200 MPa, from 120 MPa to 180 MPa, from 130 MPa to 160 MPa, or from 140 MPa to 150 MPa, as well as all ranges and subranges therebetween.

[0181] In embodiments, the maximum central tension (CT) can also be described with reference to the thickness of the glass-based article. In embodiments, the glass-based article has a maximum central tension (CT) of 360 / √(t)MPa or less (t in mm), e.g., 350 / √(t)MPa or less, 330 / √(t)MPa or less, 310 / √(t)MPa or less, 300 / √(t)MPa or less, 280 / √(t)MPa or less, 260 / √(t)MPa or less, 240 / √(t)MPa or less, 220 / √(t)MPa or less, 200 / √(t)MPa or less, 190 / √(t)MPa or less, The maximum CT may be 180 / √(t)MPa or less, 170 / √(t)MPa or less, 160 / √(t)MPa or less, 150 / √(t)MPa or less, 140 / √(t)MPa or less, 130 / √(t)MPa or less, 120 / √(t)MPa or less, 110 / √(t)MPa or less, 100 / √(t)MPa or less, 90 / √(t)MPa or less, 80 / √(t)MPa or less, 70 / √(t)MPa or less, or less. In an embodiment, the glass-based article has a modulus of 60 / √(t)MPa or more (t is in mm), e.g., 70 / √(t)MPa or more, 80 / √(t)MPa or more, 90 / √(t)MPa or more, 100 / √(t)MPa or more, 110 / √(t)MPa or more, 120 / √(t)MPa or more, 130 / √(t)MPa or more, 140 / √(t)MPa or more, 150 / √(t)MPa or more, 160 / √(t)MPa or more, 170 The maximum CT may be 180 / √(t)MPa or more, 190 / √(t)MPa or more, 200 / √(t)MPa or more, 220 / √(t)MPa or more, 240 / √(t)MPa or more, 260 / √(t)MPa or more, 280 / √(t)MPa or more, 300 / √(t)MPa or more, 320 / √(t)MPa or more, 340 / √(t)MPa or more, 350 / √(t)MPa or more or more.In embodiments, the glass-based article may have a maximum CT value of 60 / √(t)MPa or more and 360 / √(t)MPa or less (t is in mm), for example, 70 / √(t)MPa or more and 350 / √(t)MPa or less, 80 / √(t)MPa or more and 340 / √(t)MPa or less, 90 / √(t)MPa or more and 320 / √(t)MPa or less, 90 / √(t)MPa or more and 300 / √(t)MPa or less, 100 / √(t)MPa or more and 280 / √(t)MPa or less, 120 / √(t)MPa or more and 260 / √(t)MPa or less, 140 / √(t)MPa or more and 240 / √(t)MPa or less, 160 / √(t)MPa or more and 220 / √(t)MPa or less, 180 / √(t)MPa or more and 200 / √(t)MPa or less, as well as all ranges and subranges therebetween.

[0182] The glass-based article can have any suitable depth of compression (DOC). In an embodiment, the DOC is from 75 μm to 300 μm, for example, from 85 μm to 290 μm, from 95 μm to 280 μm, from 100 μm to 270 μm, from 110 μm to 260 μm, from 120 μm to 250 μm, from 130 μm to 240 μm, from 140 μm to 230 μm, from 150 μm to 220 μm, from 160 μm to 210 μm, from 170 μm to 200 μm, from 180 μm to 190 μm, and all ranges and subranges therebetween.

[0183] The DOC is provided in some embodiments herein as a fraction of the thickness (t) of the glass-based article. In embodiments, the glass article may have a depth of compression (DOC) of 0.15t or more and 0.40t or less, such as 0.18t or more and 0.38t or less, or 0.19t or more and 0.36t or less, 0.20t or more and 0.34t or less, 0.18t or more and 0.32t or more, 0.19t or more and 0.30t or more, 0.20t or more and 0.29t or less, 0.21t or more and 0.28t or less, 0.22t or more and 0.27t or more, 0.23t or more and 0.26t or less, or 0.24t or more and 0.25t or less, and all ranges and subranges therebetween.

[0184] In embodiments, the glass-based article can be characterized by any suitable DOC / t value. For example, DOC / t can be 0.12 or greater, e.g., 0.13 or greater, 0.14 or greater, 0.15 or greater, 0.16 or greater, 0.17 or greater, 0.18 or greater, 0.19 or greater, 0.20 or greater, 0.21 or greater, 0.22 or greater, 0.23 or greater, or greater.

[0185] The glass-based article can be formed by exposing a glass-based substrate to an ion exchange solution to form a glass-based article having a compressive stress layer extending from the glass-based article to a depth of compression. The ion exchange process can be carried out under conditions sufficient to produce a glass-based article that meets any of the fragility limits described herein. In embodiments, the ion exchange solution can be a molten nitrate. In some embodiments, the ion exchange solution can be molten KNO3, molten NaNO3, or a combination thereof. In certain embodiments, the ion exchange solution can include less than about 95% molten KNO3, e.g., less than about 90% molten KNO3, less than about 80% molten KNO3, less than about 70% molten KNO3, less than about 60% molten KNO3, or less than about 50% molten KNO3. In certain embodiments, the ion exchange solution can include at least about 5% molten NaNO3, e.g., at least about 10% molten NaNO3, at least about 20% molten NaNO3, at least about 30% molten NaNO3, or at least about 40% molten NaNO3. In other embodiments, the ion exchange solution may include about 95% molten KNO3 and about 5% molten NaNO3, about 94% molten KNO3 and about 6% molten NaNO3, about 93% molten KNO3 and about 7% molten NaNO3, about 80% molten KNO3 and about 20% molten NaNO3, about 75% molten KNO3 and about 25% molten NaNO3, about 70% molten KNO3 and about 30% molten NaNO3, about 65% molten KNO3 and about 35% molten NaNO3, or about 60% molten KNO3 and about 40% molten NaNO3, and all ranges and subranges between the aforementioned values. In embodiments, other sodium and potassium salts may be used in the ion exchange solution, such as, for example, sodium or potassium salts of nitrite, phosphate, or sulfate. In some embodiments, the ion exchange solution may include a lithium salt such as LiNO3.

[0186] The glass-based substrate can be exposed to the ion exchange solution by immersing the glass-based substrate in a bath of the ion exchange solution, spraying the ion exchange solution onto the glass-based substrate, or otherwise physically applying the ion exchange solution to the glass-based substrate. When exposed to the glass-based substrate, the ion exchange solution, according to embodiments, can be at a temperature of 340° C. to 500° C., e.g., 350° C. to 490° C., 360° C. to 480° C., 370° C. to 470° C., 380° C. to 460° C., 390° C. to 450° C., 400° C. to 440° C., 410° C. to 430° C., equal to 420° C., and all ranges and subranges between the aforementioned values. In embodiments, the glass composition may be exposed to the ion exchange solution for a period of time from 2 hours to 48 hours, e.g., from 4 hours to 44 hours, from 8 hours to 40 hours, from 12 hours to 36 hours, from 16 hours to 32 hours, from 20 hours to 28 hours, equal to 24 hours, and all ranges and subranges between the foregoing values.

[0187] The ion exchange process can be carried out in an ion exchange solution under processing conditions that result in an improved compressive stress profile, for example, as 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 can be selected to produce a parabolic stress profile in the glass 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.

[0188] It should be understood that after the ion-exchange process, the composition of the surface of the glass-based substrate will be different than the composition of the glass-based substrate before the glass-based substrate was subjected to the ion-exchange process. + Or Na + One type of alkali metal ion in the as-formed glass, e.g., Na + Or K +However, the glass composition at or near the center of the depth of the glass article still has the composition of the glass-based substrate, in embodiments.

[0189] The glass-based substrate that is ion-exchanged to form the glass-based article can have any suitable composition, such as an alkali aluminosilicate composition. In an embodiment, the glass-based substrate comprises SiO2, Al2O3, B2O3, and at least one alkali metal oxide. The at least one alkali metal oxide facilitates ion exchange of the glass-based substrate. For example, the glass-based substrate can comprise Li2O and / or Na2O, which are Na + and K + The ions are facilitated to exchange into the glass-based substrate to form the glass-based article. As discussed above, the composition of the glass-based substrate can be similar to the composition of the center of the glass-based article.

[0190] In the glass-based substrate embodiments 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 glass-based substrate according to the embodiments are discussed individually below. It should be understood that any of the various recited ranges for one component can be individually combined with any of the various recited ranges for any other component.

[0191] In the embodiments of the glass-based substrate disclosed herein, SiO2 is the largest component, and therefore SiO2 is the main component of the glass network formed from the glass composition. Pure SiO2 has a relatively low CTE and is alkali-free. However, pure SiO2 has a high melting point. Therefore, if the concentration of SiO2 in the glass-based substrate is too high, the formability of the glass composition may decrease, since a high concentration of SiO2 increases the difficulty of melting the glass, which in turn adversely affects the formability of the glass. In embodiments, the glass-based substrate generally comprises SiO2 in an amount of 50.0 mol% or more and 75.0 mol% or less, and all ranges and subranges therebetween. In an embodiment, the glass-based substrate comprises SiO2 in an amount of 51.0 mol% to 74.0 mol%, for example, 52.0 mol% to 73.0 mol%, 53.0 mol% to 72.0 mol%, 54.0 mol% to 71.0 mol%, 55.0 mol% to 70.0 mol%, 56.0 mol% to 69.0 mol%, 57.0 mol% to 68.0 mol%, 58.0 mol% to 67.0 mol%, 60.0 mol% to 66.0 mol%, 61.0 mol% to 65.0 mol%, 62.0 mol% to 64.0 mol%, 63.0 mol% to 64.0 mol%, and all ranges and subranges therebetween.

[0192] The glass-based substrate of the embodiment may further include Al2O3. Al2O3 can function as a glass network former, similar to SiO2. Due to its tetrahedral coordination in the glass melt formed from the glass composition, Al2O3 can increase the viscosity of the glass composition, and too much Al2O3 reduces the formability of the glass composition. However, when the concentration of Al2O3 is balanced with the concentration of SiO2 and the concentration of alkali oxides in the glass-based substrate, Al2O3 can reduce the liquidus temperature of the glass melt, thereby increasing the liquidus viscosity and improving the compatibility of the glass composition with certain forming processes, such as melt forming processes. In an embodiment, the glass-based substrate generally includes Al2O3 in a concentration of 4 mol% or more and 25.0 mol% or less, and all ranges and subranges between the aforementioned values. In an embodiment, the glass-based substrate comprises Al2O3 in an amount of 5.0 mol% to 24.5 mol%, e.g., 6 mol% to 24.0 mol%, 7 mol% to 23.5 mol%, 8 mol% to 23.0 mol%, 9 mol% to 22.5 mol%, 10 mol% to 22.0 mol%, 11 mol% to 21.5 mol%, 12 mol% to 21.0 mol%, 13 mol% to 20.5 mol%, 14 mol% to 20.0 mol%, 15 mol% to 19.5 mol%, or 16 mol% to 19.0 mol%, as well as all ranges and subranges between the aforesaid values.

[0193] Similar to SiO2 and Al2O3, B2O3 can be added to the glass-based substrate as a network former, which reduces the meltability and formability of the glass composition. Thus, B2O3 can be added in an amount that does not unduly reduce these properties. In an embodiment, the glass-based substrate can include B2O3 in an amount from 0 mol% or more B2O3 to 8.0 mol% or less B2O3, and all ranges and subranges between the aforementioned values. In an embodiment, the glass-based substrate includes B2O3 in an amount from 0.5 mol% to 7.5 mol%, for example, from 1.0 mol% to 7.0 mol%, from 1.5 mol% to 6.5 mol%, from 2.0 mol% to 6.0 mol%, from 2.5 mol% to 5.5 mol%, from 3.0 mol% to 5.0 mol%, or from 3.5 mol% to 4.5 mol%, and all ranges and subranges between the aforementioned values.

[0194] The inclusion of Li2O in the glass-based substrate allows for better control of the ion-exchange process and also reduces the softening point of the glass, thereby improving the manufacturability of the glass. In an embodiment, the glass-based substrate generally includes Li2O in an amount greater than 8.0 mol% and up to 18.0 mol%, as well as all ranges and subranges between the aforementioned values. In an embodiment, the glass-based substrate includes Li2O in an amount of 8.5 mol% or more and up to 17.5 mol%, for example, 9.0 mol% or more and up to 17.0 mol%, 9.5 mol% or more and up to 16.5 mol%, 10.0 mol% or more and up to 16.0 mol%, 10.5 mol% or more and up to 15.5 mol%, 11.0 mol% or more and up to 15.0 mol%, 11.5 mol% or more and up to 14.5 mol%, 12.0 mol% or more and up to 14.0 mol%, or 12.5 mol% or more and up to 13.5 mol%, as well as all ranges and subranges between the aforementioned values. In some embodiments, the glass-based substrate may be substantially free or free of Li2O.

[0195] According to embodiments, the glass-based substrate may include an alkali metal oxide such as Na2O other than or in addition to Li2O. Na2O aids in the ion exchange ability of the glass composition and also improves the formability and therefore manufacturability of the glass composition. However, adding too much Na2O to the glass-based substrate may result in too high a CTE and too high a melting point. In embodiments, the glass-based substrate generally includes Na2O in an amount from 0.5 mol% or more Na2O to 20.0 mol% or less Na2O, and all ranges and subranges therebetween. In embodiments, the glass-based substrate comprises Na2O in an amount of 1.0 mol% or more and 18 mol% or less, e.g., 1.5 mol% or more and 16 mol% or less, 2.0 mol% or more and 14 mol% or less, 2.5 mol% or more and 12 mol% or less, 3.0 mol% or more and 10 mol% or less, 3.5 mol% or more and 8 mol% or less, or 4.0 mol% or more and 6 mol% or less, and all ranges and subranges therebetween of the foregoing values. In some embodiments, the glass-based substrate is substantially free or may be free of Na2O.

[0196] Similar to Na2O, K2O also promotes ion exchange and increases the DOC of the compressive stress layer. However, adding K2O may result in a too low CTE and too high melting point. In some embodiments, the glass-based substrate may include K2O. In an embodiment, the glass composition is substantially free of potassium. As used herein, the term "substantially free" means that the component is not added as a component of the batch material, even though the component may be present in the final glass in very small amounts as a contaminant, e.g., less than 0.01 mol %. In other embodiments, K2O may be present in the glass-based substrate in an amount less than 1 mol %.

[0197] MgO reduces the viscosity of glass, enhancing the formability and manufacturability of glass. The inclusion of MgO in a glass-based substrate can also improve the strain point and Young's modulus of the glass composition, and can also improve the ion exchange capacity of the glass. However, adding too much MgO to the glass composition can result in an undesirable increase in the density and CTE of the glass composition. In embodiments, the glass-based substrate generally includes MgO in a concentration of 0 mol% to 17.5 mol%, inclusive, and all ranges and subranges therebetween. In an embodiment, the glass-based substrate contains MgO in an amount of 0.5 mol % or more and 17.0 mol % or less, for example, 1.0 mol % or more and 16.5 mol % or less, 1.5 mol % or more and 16.0 mol % or less, 2.0 mol % or more and 15.5 mol % or less, 2.5 mol % or more and 15.0 mol % or less, 3.0 mol % or more and 14.5 mol % or less, 3.5 mol % or more and 14.0 mol % or less, 4.0 mol % or more and 13.5 mol % or less, 4.5 mol % or more and 13.5 mol % or less, .0 mol% or less, 5.0 mol% to 12.5 mol%, 5.5 mol% to 12.0 mol%, 6.0 mol% to 11.5 mol%, 6.5 mol% to 11.0 mol%, 7.0 mol% to 10.5 mol%, 7.5 mol% to 10.0 mol%, 8.0 mol% to 9.5 mol%, or 8.5 mol% to 9.0 mol%, as well as all ranges and subranges between the aforesaid values.

[0198] CaO can reduce the viscosity of glass, increase the formability, strain point and Young's modulus, and improve ion exchange capacity. However, adding too much CaO to a glass-based substrate increases the density and CTE of the glass composition. In an embodiment, the glass-based substrate generally comprises CaO in a concentration of 0 mol% or more and 4.0 mol% or less, and all ranges and subranges between the aforementioned values. In an embodiment, the glass-based substrate comprises CaO in an amount of 0.5 mol% or more and 3.5 mol% or less, for example, 1.0 mol% or more and 3.0 mol% or less, or 1.5 mol% or more and 2.5 mol% or less, and all ranges and subranges between the aforementioned values.

[0199] TiO2 also contributes to improving the toughness of the glass while softening the glass. However, if too much TiO2 is added to the glass composition, the glass becomes prone to devitrification and exhibits undesirable coloration. In embodiments, the glass-based substrate comprises TiO2 in a concentration of, for example, 0 mol% to 2.0 mol%, and all ranges and subranges therebetween. In embodiments, the glass-based substrate comprises TiO2 in an amount of 0.5 mol% to 1.5 mol%. In some embodiments, the glass-based substrate is free or substantially free of TiO2.

[0200] ZrO2 contributes to the toughness of the glass. However, adding too much ZrO2 to the glass composition can result in the formation of undesirable zirconia inclusions in the glass, due at least in part to the low solubility of ZrO2 in the glass. In embodiments, the glass-based substrate comprises ZrO2 in a concentration of 0 mol% to 2.5 mol%, and all ranges and subranges therebetween. In embodiments, the glass-based substrate comprises ZrO2 in an amount of 0.5 mol% to 2.0 mol%, such as 1.0 mol% to 1.5 mol%, and all ranges and subranges therebetween. In some embodiments, the glass-based substrate is free or substantially free of ZrO2.

[0201] SrO reduces the liquidus temperature of the glass compositions disclosed herein. In embodiments, the glass-based substrate can include SrO in an amount of from 0 mol% to 2.0 mol%, such as from 0.2 mol% to 1.5 mol%, or from 0.4 mol% to 1.0 mol%, and all ranges and subranges therebetween. In some embodiments, the glass-based substrate can be substantially free or free of SrO.

[0202] In embodiments, the glass-based substrate may optionally include one or more fining agents. In some embodiments, the fining agent may include, for example, SnO2. In such embodiments, SnO2 may be present in the glass-based substrate in an amount of 0.2 mol% or less, such as from 0 mol% to 0.1 mol% or less, and all ranges and subranges between the aforementioned values. In other embodiments, SnO2 may be present in the glass-based substrate in an amount of 0 mol% to 0.2 mol%, or from 0.1 mol% to 0.2 mol%, and all ranges and subranges between the aforementioned values. In some embodiments, the glass-based substrate may be substantially free or free of SnO2.

[0203] In embodiments, the glass-based substrate may be substantially free of arsenic and / or antimony, hi other embodiments, the glass-based substrate may be free of arsenic and / or antimony.

[0204] In one or more embodiments, the glass-based articles described herein can exhibit an amorphous microstructure and may be substantially free of crystals or crystallites. In other words, the glass-based articles can, in some embodiments, exclude glass-ceramic materials.

[0205] The glass-based substrate may comprise a glass ceramic. The glass ceramic may comprise any suitable crystal structure, such as lithium silicate, beta-spodumene, or spinel crystal structures. The glass ceramic, including the glass-based substrate, may be formed by any suitable method, such as by ceramming a precursor glass.

[0206] The glass-based substrate can be manufactured by any suitable method. In embodiments, the glass-based substrate can be formed by processes including slot forming, float forming, rolling processes, and melt forming processes. The drawing process for forming the glass-based substrate is desirable because it can form thin glass articles with few defects.

[0207] Glass-based substrates can be characterized by the methods by which they can be formed. For example, glass-based substrates can be characterized as float formable (i.e., formed by a float process), down drawable, and especially melt formable or slot drawable (i.e., formed by a down draw process such as a fusion draw process or a slot draw process).

[0208] Some embodiments of the glass-based articles described herein can be formed by a down-draw process. The down-draw process produces a uniform thickness glass-based substrate with a relatively flawless surface. A flawless surface with minimal contact has a higher initial strength, since the average bending strength of the glass-based substrate and the resulting glass-based article is controlled by the amount and size of surface flaws. In addition, the downwardly drawn glass-based substrate has a very flat and smooth surface and can be used for its end use without expensive grinding and polishing.

[0209] Some embodiments of glass-based substrates can be described as fusion formable (i.e., formable using the fusion draw process). The fusion process uses a drawing tank with a channel for receiving molten glass frit. The channel has open-topped weirs on either side of the channel along the length of the channel. When the channel is filled with molten material, the molten glass spills over the weirs. Due to gravity, the molten glass flows down the outer surface of the drawing tank as two flowing glass films. These outer surfaces of the drawing tank extend downward and inward to meet at the lower edge of the drawing tank. The two flowing glass films meet at this edge and fuse to form a single flowing glass article. The fusion draw process offers the advantage that, because the two glass films flowing on the channel fuse to each other, neither of the outer surfaces of the resulting glass-based substrate comes into contact with any part of the apparatus. Thus, the surface properties of the fusion-drawn glass-based substrate are not affected by such contact.

[0210] Some embodiments of the glass-based substrates 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 glass is fed into a drawing tank. The bottom of the drawing tank has an open slot with a nozzle that runs the length of the slot. The molten glass flows through the slot / nozzle and is drawn downward into an annealing region as a continuous glass-based substrate.

[0211] The glass-based articles disclosed herein can be incorporated into another article, such as an article or articles with a display (e.g., consumer electronics including mobile phones, tablets, computers, navigation systems, etc.), a building product, a transportation product (e.g., automobiles, trains, aircraft, watercraft, etc.), a home appliance product, or any article that requires some degree of transparency, scratch resistance, abrasion resistance, or combinations thereof. An exemplary article incorporating any of the glass-based articles disclosed herein is shown in Figures 12A and 12B. Specifically, Figures 12A and 12B show a consumer electronics device 200 including a housing 202 having a front surface 204, a back surface 206, and a side surface 208; electrical components (not shown) at least partially within or entirely within the housing, including at least a controller, memory, and a display 210 at or adjacent to the front surface of the housing; and a cover substrate 212 at or on the front surface of the housing such that it is above the display. The cover substrate 212 and / or the housing can include any of the glass-based articles disclosed herein.

[0212] All ranges disclosed herein include any and all ranges and subranges encompassed by the broadly disclosed ranges, whether or not the ranges are explicitly stated before or after the ranges are disclosed.

[0213] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Accordingly, it is intended that the present specification cover modifications and variations of the various embodiments described herein, provided that such modifications and variations come within the scope of the appended claims and their equivalents.

[0214] Preferred embodiments of the present invention will be described below in detail.

[0215] EMBODIMENT 1 1. A glass-based article comprising: First surface; A second surface; and a stress profile having a first compressive region extending from a first surface to a first depth of compression DOC1, a second compressive region extending from a second surface to a second depth of compression DOC2, and a tensile region extending from DOC1 to DOC2. Including, The tensile region is 1.31MPa √(m) or more and 1.8 K IC Tensile stress coefficient K less than T where K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article; Glass-based items.

[0216] EMBODIMENT 2 K T 2. The glass-based article of claim 1, wherein the elastic modulus is 1.41 MPa √(m) or greater.

[0217] EMBODIMENT 3 K T 2.0 MPa √(m) or greater.

[0218] EMBODIMENT 4 K T is 1.781 K IC 2. The glass-based article of embodiment 1, wherein:

[0219] EMBODIMENT 5 K IC 2. The glass-based article of claim 1, wherein the elastic modulus is 0.67 MPa √(m) or greater.

[0220] EMBODIMENT 6 K IC 2. The glass-based article of embodiment 1, wherein the elastic modulus is 1.3 MPa·√(m) or more.

[0221] EMBODIMENT 7 2. The glass-based article of embodiment 1 comprising an alkali aluminosilicate.

[0222] EMBODIMENT 8 2. The glass-based article of claim 1, wherein DOC1 = DOC2, measured from the first and second surfaces, respectively.

[0223] EMBODIMENT 9 2. The glass-based article of claim 1, wherein the glass-based article is non-brittle.

[0224] EMBODIMENT 10 In consumer electronics, A housing including a front, back, and sides; an electrical component at least partially within the housing, the electrical component comprising at least a controller, a memory, and a display, the display being at or adjacent to the front surface of the housing; and A cover substrate disposed over the display. It is equipped with At least one portion of the housing or the cover substrate comprises the glass-based article of embodiment 1; Consumer electronics.

[0225] EMBODIMENT 11 1. A glass-based article comprising: Surface; and A stress profile having a compressive region extending from the surface to the depth of compression DOC and a tensile region. Including, The tensile region is 1.31MPa √(m) or more and K T 限界 The tensile stress coefficient K T where K T 限界 is defined by:

[0226]

number

[0227] In the formula, K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article, and t is the thickness of the glass-based article. Glass-based items.

[0228] EMBODIMENT 12 K T 12. The glass-based article of claim 11, wherein the elastic modulus is 1.41 MPa √(m) or greater.

[0229] EMBODIMENT 13 K T 12. The glass-based article of claim 11, wherein the elastic modulus is 2.0 MPa √(m) or greater.

[0230] EMBODIMENT 14 12. The glass-based article of claim 11, wherein the DOC / t is greater than 0.12.

[0231] EMBODIMENT 15 12. The glass-based article of claim 11, wherein the DOC / t is greater than 0.18.

[0232] EMBODIMENT 16 K IC 12. The glass-based article of claim 11, wherein the elastic modulus is 0.67 MPa √(m) or greater.

[0233] EMBODIMENT 17 K IC 12. The glass-based article of claim 11, wherein the elastic modulus is 1.3 MPa √(m) or more.

[0234] EMBODIMENT 18 12. The glass-based article of embodiment 11, comprising an alkali aluminosilicate.

[0235] EMBODIMENT 19 12. The glass-based article of claim 11, wherein the glass-based article is non-brittle.

[0236] EMBODIMENT 20 In consumer electronics, A housing including a front, back, and sides; an electrical component at least partially within the housing, the electrical component comprising at least a controller, a memory, and a display, the display being at or adjacent to the front surface of the housing; and A cover substrate disposed over the display. It is equipped with A portion of at least one of the housing or the cover substrate comprises the glass-based article of embodiment 11. Consumer electronics.

[0237] EMBODIMENT 21 1. A glass-based article comprising: First surface; A second surface; and a stress profile having a first compressive region extending from a first surface to a first depth of compression DOC1, a second compressive region extending from a second surface to a second depth of compression DOC2, and a tensile region extending from DOC1 to DOC2. Including, The tensile region is 1.31MPa √(m) or more and K T 限界 The tensile stress coefficient K T where K T 限界 is defined by:

[0238]

number

[0239] In the formula, K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article, t is the thickness of the glass-based article, and the DOC1 and DOC2 are measured from the first surface. Glass-based items.

[0240] EMBODIMENT 22 K T 22. The glass-based article of claim 21, wherein the elastic modulus is 1.41 MPa √(m) or greater.

[0241] EMBODIMENT 23 K T 22. The glass-based article of claim 21, wherein the elastic modulus is 2.0 MPa √(m) or greater.

[0242] EMBODIMENT 24 K T 0.95K T 限界 22. The glass-based article of embodiment 21, wherein:

[0243] EMBODIMENT 25 K T 0.85K T 限界 22. The glass-based article of embodiment 21, wherein:

[0244] EMBODIMENT 26 K IC 22. The glass-based article of claim 21, wherein the elastic modulus is 0.67 MPa √(m) or greater.

[0245] EMBODIMENT 27 K IC 22. The glass-based article of claim 21, wherein the elastic modulus is 1.3 MPa √(m) or greater.

[0246] EMBODIMENT 28 22. The glass-based article of embodiment 21, comprising an alkali aluminosilicate.

[0247] EMBODIMENT 29 22. The glass-based article of embodiment 21, wherein DOC1=t-DOC2.

[0248] EMBODIMENT 30 22. The glass-based article of claim 21, wherein the glass-based article is non-brittle.

[0249] EMBODIMENT 31 In consumer electronics, A housing including a front, back, and sides; an electrical component at least partially within the housing, the electrical component comprising at least a controller, a memory, and a display, the display being at or adjacent to the front surface of the housing; and A cover substrate disposed over the display. It is equipped with 22. A glass-based article according to claim 21, wherein at least one of the housing or the cover substrate comprises a portion of the glass-based article according to claim 21. Consumer electronics.

[0250] EMBODIMENT 32 1. A glass-based article comprising: Surface; and A stress profile with compressive and tensile regions extending from the surface to the depth of compression DOC. Including, The compression region is a compressive stress coefficient K CS and the tensile region has a tensile stress coefficient K of 1.31 MPa √(m) or more. T and:

[0251]

number

[0252] where K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article; Glass-based items.

[0253] EMBODIMENT 33

[0254]

number

[0255] 33. The glass-based article of embodiment 32, wherein

[0256] EMBODIMENT 34

[0257]

number

[0258] 33. The glass-based article of embodiment 32, wherein

[0259] EMBODIMENT 35 K T 33. The glass-based article of claim 32, wherein the elastic modulus is 1.41 MPa √(m) or greater.

[0260] EMBODIMENT 36 K T 33. The glass-based article of embodiment 32, wherein the elastic modulus is 2.0 MPa √(m) or greater.

[0261] EMBODIMENT 37 33. The glass-based article of embodiment 32, comprising an alkali aluminosilicate.

[0262] EMBODIMENT 38 33. The glass-based article of claim 32, wherein the glass-based article is non-brittle.

[0263] EMBODIMENT 39 In consumer electronics, A housing including a front, back, and sides; an electrical component at least partially within the housing, the electrical component comprising at least a controller, a memory, and a display, the display being at or adjacent to the front surface of the housing; and A cover substrate disposed over the display. It is equipped with 33. A portion of at least one of the housing or the cover substrate comprises the glass-based article of claim 32. Consumer electronics.

[0264] EMBODIMENT 40 1. A glass-based article comprising: First surface; A second surface; and a stress profile having a first compressive region extending from a first surface to a first depth of compression DOC1, a second compressive region extending from a second surface to a second depth of compression DOC2, and a tensile region extending from DOC1 to DOC2. Including, The tensile region is 1.31MPa √(m) or more and 1.8 K IC Tensile stress coefficient K less than T where K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article; Glass-based items.

[0265] EMBODIMENT 41 1. A glass-based article comprising: Surface; and A stress profile having a compressive region extending from the surface to the depth of compression DOC and a tensile region. Including, The tensile region is 1.31MPa √(m) or more and K T 限界 The tensile stress coefficient K T where K T 限界 is defined by:

[0266]

number

[0267] In the formula, K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article, and t is the thickness of the glass-based article. Glass-based items.

[0268] EMBODIMENT 42 42. The glass-based article of embodiment 41, having a DOC / t greater than 0.12.

[0269] EMBODIMENT 43 1. A glass-based article comprising: First surface; A second surface; and a stress profile having a first compressive region extending from a first surface to a first depth of compression DOC1, a second compressive region extending from a second surface to a second depth of compression DOC2, and a tensile region extending from DOC1 to DOC2. Including, The tensile region is 1.31MPa √(m) or more and K T 限界 The tensile stress coefficient K T where K T 限界 is defined by:

[0270]

number

[0271] In the formula, K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article, t is the thickness of the glass-based article, and the DOC1 and DOC2 are measured from the first surface. Glass-based items.

[0272] EMBODIMENT 44 K IC 44. The glass-based article of any one of claims 40, 41, and 43, wherein the elongation constant is 0.67 MPa √(m) or greater.

[0273] EMBODIMENT 45 1. A glass-based article comprising: Surface; and A stress profile having a compressive region extending from the surface to the depth of compression DOC and a tensile region. Including, The compression region has a compressive stress coefficient K CS and the tensile region has a tensile stress coefficient K of 1.31 MPa √(m) or more. T and:

[0274]

number

[0275] where K IC is the fracture toughness of a glass-based substrate having the same composition as the center of the glass-based article; Glass-based items.

[0276] EMBODIMENT 46

[0277]

number

[0278] 46. ​​The glass-based article of embodiment 45, wherein EMBODIMENT 47 K T 46. ​​The glass-based article of any one of claims 40, 41, 43, and 45, wherein the elastic modulus is 1.41 MPa √(m) or greater.

[0279] EMBODIMENT 48 46. ​​The glass-based article of any one of claims 40, 41, 43, and 45, wherein the glass-based article is non-brittle.

[0280] EMBODIMENT 49 In consumer electronics, A housing including a front, back, and sides; an electrical component at least partially within the housing, the electrical component comprising at least a controller, a memory, and a display, the display being at or adjacent to the front surface of the housing; and A cover substrate disposed over the display. It is equipped with At least one portion of the housing or the cover substrate comprises the glass-based article of any one of embodiments 40, 41, 43, and 45. Consumer electronics. [Explanation of symbols]

[0281] 100 Glass-based products 110 First Surface 112 Second Surface 120 First Segment 122 Second Segment 130 Central area 135 Impact Point 140 Cracked Branch 142 Debris 150 Branch 200 Consumer Electronics 202 Case 204 Front 206 206 208 Side 210 Display 212 Cover board

Claims

1. Glass-based articles, First surface; The second surface; and First depth of compression from the first surface DOC １ A first compression region extending to the second surface, and a second compression depth DOC ２ A second compression region extending to, and DOC １ From DOC ２ Stress profile with a tensile region extending to Includes, The tensile region is 1.31 MPa·√(m) or greater and 1.9·K ＩＣ Tensile stress coefficient K less than Ｔ It has, and here, K ＩＣ This is the fracture toughness of a glass-based substrate having the same composition as the core of the aforementioned glass-based article. Glass-based articles.

2. Glass-based articles, Surface; and A stress profile having a compression region extending from the surface to the compression depth DOC and a tensile region. Includes, The tensile region is 1.31 MPa·√(m) or more and K Ｔ 限界 has the following tensile stress coefficient K Ｔ where K Ｔ 限界 is defined as follows: [Math 1] In the ceremony, K ＩＣ is the fracture toughness of a glass substrate having the same composition as the core of the glass article, and t is the thickness of the glass article. Glass-based articles.

3. A glass-based article according to claim 2, wherein the DOC / t is greater than 0.

12.

4. Glass-based articles, First surface; The second surface; and First depth of compression from the first surface DOC １ A first compression region extending to the second surface, and a second compression depth DOC ２ A second compression region extending to, and DOC １ From DOC ２ Stress profile with a tensile region extending to Includes, The tensile region is 1.31 MPa·√(m) or more and K Ｔ 限界 The following tensile stress coefficient K Ｔ It has, and here, K Ｔ 限界 It is defined by: [Math 2] In the ceremony, K ＩＣ is the fracture toughness of a glass substrate having the same composition as the core of the glass article, t is the thickness of the glass article, and the DOC １ and the DOC ２ This is measured from the first surface, Glass-based articles.

5. K ＩＣ A glass-based article according to any one of claims 1, 2, and 4, wherein the pressure is 0.67 MPa·√(m) or greater.

6. Glass-based articles, Surface; and A stress profile having a compression region extending from the surface to the compression depth DOC and a tensile region. Includes, The compression region has a compressive stress coefficient K ＣＳ The tensile region has a tensile stress coefficient K of 1.31 MPa·√(m) or more. Ｔ It has, and: [Math 3] And here, K ＩＣ This is the fracture toughness of a glass-based substrate having the same composition as the core of the aforementioned glass-based article. Glass-based articles. [Request Item 7] [Number 4] The glass-based article according to claim 6.

8. K Ｔ A glass-based article according to any one of claims 1, 2, 4, and 6, wherein the pressure is 1.41 MPa·√(m) or greater.

9. The glass-based article according to any one of claims 1, 2, 4, and 6, wherein the glass-based article is non-fragile.

10. In consumer electronic products, Enclosure including the front, back, and sides; An electrical component that is at least partially located within the housing, wherein the electrical component comprises at least a controller, memory, and a display, and the display is located on or adjacent to the front of the housing; and Cover substrate placed on top of the display It is equipped with, At least one part of the housing or the cover substrate includes a glass-based article as described in any one of claims 1, 2, 4, and 6. Consumer electronic products.

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