阅读说明：本技术 强化玻璃制品及其形成方法 (Strengthened glass articles and methods of forming the same ) 是由 金宇辉 约书亚·詹姆斯·麦卡斯林 朴钟世 维托·马里诺·施耐德 孙伟 于 2021-05-14 设计创作，主要内容包括：一种玻璃制品以及形成该玻璃制品的方法,所述玻璃制品包括玻璃主体,该玻璃主体具有相对的第一主表面和第二主表面以及在主表面之间限定的厚度。玻璃主体包括压缩应力区域,所述压缩应力区域包括：大于约900MPa的表面应力(压缩),具有第一斜率的尖峰区域,以及具有第二斜率的尾部区域。尖峰区域和尾部区域可在具有大于约35MPa应力(压缩)的拐点区域相交,其中,拐点区域处的应力定义为尖峰区域和尾部区域的渐近外推交点。尖峰区域的第一斜率可比约-30MPa/μm更陡。(A glass article and method of forming the same includes a glass body having first and second opposing major surfaces and a thickness defined between the major surfaces. The glass body includes a compressive stress region comprising: a surface stress (compression) greater than about 900MPa, a peak region having a first slope, and a tail region having a second slope. The spike region and the tail region may intersect at an inflection region having a stress (compression) greater than about 35MPa, wherein the stress at the inflection region is defined as an asymptotically extrapolated intersection of the spike region and the tail region. The first slope of the spike region may be steeper than about-30 MPa/μm.)

1. A glass article comprising:

a glass body having opposing first and second major surfaces and a thickness defined therebetween, an

Wherein the glass body comprises a compressive stress region comprising:

a surface stress (compression) greater than about 900 MPa;

a spike region having a first slope; and

a tail region having a second slope, an

Wherein the spike region and the tail region intersect at an inflection region having a stress (compression) greater than about 35MPa, and wherein the stress at the inflection region is defined as the point at which an asymptotic extrapolation of the spike region and the tail region intersect, an

Wherein the first slope of the spike region is steeper than about-30 MPa/μm.

2. The glass article of claim 1, wherein the compressive stress region has a depth of compression greater than about 0.16 x (Th) at which the stress within the glass body is 0, wherein Th is the thickness of the glass body.

3. The glass article of claim 2, wherein a slope of the tail region from the inflection region to a compression depth is greater than about 241/(Th) MPa/μm, where Th is a thickness of the glass body in μm.

4. The glass article of claim 1, wherein a depth of layer of the spike region is greater than about 10 μ ι η.

5. The glass article of claim 1, wherein the surface stress of the compressive stress region is greater than about 950MPa (compression).

6. The glass article of any of claims 1-5, wherein the glass body is non-frangible and has a glass body Center Tension (CT) according to formula (I):

CT<(E/68GPa)*75MPa*1mm^0.5/(Th)^0.5 (I)

wherein E is the Young's modulus of the glass body, measured in GPa; th is the thickness of the glass body, measured in millimeters.

7. The glass article of any of claims 1-5, wherein the glass body is non-frangible and has less than about 20J/m²Tensile energy of

8. The glass article of any of claims 1-5, wherein the glass body is non-frangible and has less than about 60MPa²m^0.5Normalized tensile energy per thickness of

9. The glass article of any of claims 1-5, wherein the glass body is frangible and has a glass body Center Tension (CT) according to formula (I):

CT>(E/68GPa)*75MPa*1mm^0.5/(Th)^0.5 (I)

wherein E is the Young's modulus of the glass body, measured in GPa; th is the thickness of the glass body, measured in millimeters.

10. The glass article of any of claims 1-5, wherein the glass body is frangible and has greater than about 20J/m²Tensile energy of

11. The glass article of any of claims 1-5, wherein the glass body is frangible and has greater than about 60MPa²m^0.5Normalized tensile energy per thickness of

12. The glass article of any of claims 1-5, wherein the glass body has a thickness of about 0.2mm to about 1.3 mm.

13. A method of forming a plurality of glass articles, comprising:

a first ion exchange step comprising immersing a glass article in a first molten salt bath comprising potassium and sodium salts for a first predetermined period of time, wherein the glass article comprises a glass body having opposing first and second major surfaces and a thickness defined therebetween;

a second ion exchange step subsequent to the first ion exchange step, the second ion exchange step comprising immersing the glass article in a second molten salt bath comprising a potassium salt for a second predetermined period of time to form a compressive stress region having a surface stress (compression) greater than about 900 MPa; and

repeating the first ion exchange step and the second ion exchange step for one or more additional glass articles, wherein 0.0228m per kilogram potassium salt in the second molten salt bath²The surface area of the glass article is loaded, and the amount of increase in surface stress of each glass article in the second ion exchange step decreases by less than about 6MPa in each cycle of the first and second ion exchange steps.

14. The method of claim 13, wherein 0.0065m per kg of potassium salt in the second molten salt bath²A surface area glass article loading, a surface stress increase per cycle decrease per each glass article in the second ion exchange step of less than about 2 MPa.

15. The method of claim 13, wherein the initial concentration of potassium salt in the second molten salt bath is 100% (by weight).

16. The method of any of claims 13-15, wherein the compressive stress region of the first glass treated in the second ion exchange step has a surface stress greater than about 1000 MPa.

17. The method of any one of claims 13-15, wherein the first molten salt bath comprises about 80% potassium and 20% sodium (by weight).

18. The method of any one of claims 13-15, wherein the plurality of glass articles comprises lithium-based glass, the method further comprising replacing or regenerating the second molten salt bath when the lithium concentration in the second molten salt bath is from about 0.125% to about 0.25% (by weight).

19. The method of any of claims 13-15, wherein the second predetermined period of time is about 0.5 hours to about 4 hours.

20. The method of any of claims 13-15, wherein the first predetermined period of time is about 6 hours.

21. The method of any of claims 13-15, wherein the compressive stress region further comprises:

a spike region having a first slope; and

a tail region having a second slope, an

Wherein the spike region and the tail region intersect at a knee region having a stress (compression) greater than about 35MPa, wherein the stress at the knee region is defined as the point at which asymptotically extrapolated intersections of the spike region and the tail region, an

Wherein the first slope of the spike region is steeper than about-30 MPa/μm.

22. The method according to claim 21, wherein the compressive stress region has a depth of compression greater than about 0.16 x (Th), at which the stress within the glass body is 0, wherein Th is the thickness of the glass body.

23. The method of claim 21, wherein a slope of the tail region from the inflection region to the compression depth is greater than about 241/(Th) MPa/μm, where Th is a thickness of the glass body in μm.

24. The method of claim 21, wherein the peak region has a depth of layer greater than about 10 μm.

25. The method of any of claims 13-15, wherein the glass body is non-frangible and has one of:

tension (CT) at center of glass body according to formula (I):

CT<(E/68GPa)*75MPa*1mm^0.5/(Th)^0.5 (I)

wherein E is the Young's modulus of the glass body, measured in GPa, and Th is the thickness of the glass body, measured in millimeters;

less than about 20J/m²Tensile energy of

Less than about 60MPa²m^0.5Normalized tensile energy per thickness ofOr

Combinations thereof.

26. The method of any of claims 13-15, wherein the glass body is frangible and has one of:

tension (CT) at center of glass body according to formula (I):

CT>(E/68GPa)*75MPa*1mm^0.5/(Th)^0.5 (I)

wherein E is the Young's modulus of the glass body, measured in GPa, and Th is the thickness of the glass body, measured in millimeters;

greater than about 20J/m²Tensile energy of

Greater than about 60MPa²m^0.5Normalized tensile energy per thickness ofOr

Combinations thereof.

27. The method of any of claims 13-15, wherein the glass body has a thickness of about 0.2mm to about 1.3 mm.

Technical Field

The present disclosure relates generally to strengthened glass articles and methods of forming the same, and more particularly to chemically strengthened glass articles suitable for use in the automotive industry and methods of forming the same.

Background

Chemically strengthened glass is used in a variety of different applications, examples of which include hand-held electronic devices, such as mobile phones. Chemical strengthening (also referred to as ion exchange) of the glass can create a stress distribution within the glass that provides the glass with desired characteristics, such as strength or brittleness, depending on the intended use of the glass.

Glass used in the automotive industry may be used, for example, in windshields, windows, displays and mirrors, which may need to meet certain safety standards, one example including Head Impact Test (HIT). The HIT regulations are regulated by government regulations and thus may vary from geographical region to geographical region. For example, in the united states, the relevant HIT regulation is Federal Motor Vehicle Safety Standard (FMVSS) 201. In china, the relevant HIT regulation is GB11552-2009, and in europe and the united nations countries, the relevant HIT regulation is the united nations european Economic Commission (ECE) UN-R21. Conventional glass used in the automotive industry typically comprises glass laminates that can provide sufficient impact resistance for automotive applications at a reasonable cost. However, these glass laminates may be heavy and may not provide all of the characteristics required for a particular application.

Chemical strengthening can be used with relatively thin glass materials to produce materials with high levels of compressive stress. However, conventional ion exchange techniques have limited ability to produce stress profiles with certain levels of compressive stress and other characteristics suitable for meeting safety standards used in automotive applications. Another challenge with ion exchange technology is to provide a process that can handle sufficient glass loading to be available to the manufacturing process before process materials need to be replaced and/or regenerated.

In view of these considerations, there is a need for strengthened glass articles having stress profiles that can meet automotive safety standards (such as head impact testing), and which can be formed using ion exchange processes that can chemically strengthen sufficient glass loading to be suitable for use in a manufacturing environment.

Disclosure of Invention

According to one aspect of the present disclosure, a glass article includes a glass body having opposing first and second major surfaces and a thickness defined between the major surfaces. The glass body includes a compressive stress region comprising: a surface stress (compression) greater than about 900MPa, a peak region having a first slope, and a tail region having a second slope. The spike region and the tail region may intersect at a knee region having a stress (compression) greater than about 35MPa, wherein the stress at the knee region is defined as the point at which an asymptotic extrapolation of the spike region and the tail region intersect. The first slope of the spike region may be steeper than about-30 MPa/μm.

According to another aspect of the present disclosure, a method of forming a plurality of glass articles is provided. The method may include a first ion exchange step including immersing a glass article in a first molten salt bath including a potassium salt and a sodium salt for a first predetermined period of time, wherein the glass article includes a glass body having opposing first and second major surfaces and a thickness defined between the major surfaces, and a second ion exchange step after the first ion exchange step including immersing the glass article in a second molten salt bath including a potassium salt for a second predetermined period of time to form a compressive stress region having a surface stress (compression) greater than about 900 MPa. The method may further comprise repeating the first ion exchange step and the second ion exchange step for one or more additional glass articles, wherein 0.0228m per kilogram of potassium salt in the second molten salt bath²Surface area glass article loading, surface stress enhancement of each glass article during the second ion exchange stepA reduction of less than about 6MPa per cycle.

These and other aspects, objects, and features of the disclosure will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.

Drawings

In the drawings:

FIG. 1 is a schematic cross-sectional view of a chemically strengthened glass article, according to one aspect of the present disclosure;

FIG. 2 is a schematic illustration of a stress distribution of the chemically strengthened glass article of FIG. 1, in accordance with an aspect of the present disclosure;

FIG. 3 is a flow chart of a method of chemically strengthening a glass article according to one aspect of the present disclosure;

FIG. 4A is a surface stress (CS) and depth of layer (DOL) in accordance with an aspect of the present disclosure_k) A graph as a function of the number of cycles of use of the second ion-exchange molten salt bath (after immersion in the first ion-exchange molten salt bath);

FIG. 4B is a surface stress (CS) and depth of layer (DOL) of an exemplary ion exchange process, according to an aspect of the present disclosure_k) A graph as a function of the number of cycles of use of the second ion-exchange molten salt bath (after immersion in the first ion-exchange molten salt bath);

FIG. 5 is a stress profile of a glass article treated according to an exemplary ion exchange process having first and second ion exchange steps in which the treatment time periods are different, according to one aspect of the present disclosure;

FIG. 6A is an image of a glass article treated in the first ion exchange step of an exemplary ion exchange process, the image obtained using a FSM-6000LE surface stress meter from Orihara, Japan, operating at a wavelength of 589nm, according to one aspect of the present disclosure;

fig. 6B is an image of the glass article of fig. 6A after processing in the second ion exchange step of the exemplary ion exchange process, the image obtained using a FSM-6000LE surface stress meter from Orihara, japan operating at a wavelength of 589nm, according to one aspect of the present disclosure;

FIG. 7 is a stress profile of a glass article treated according to an exemplary ion exchange process having first and second ion exchange steps with different levels of lithium poisoning in the second ion exchange step, according to one aspect of the present disclosure;

FIG. 8 is a schematic view of a HIT system for determining surface damage of a glass article, according to one aspect of the present disclosure; and

FIG. 9 is a graph of exemplary deceleration and intrusion curves measured using the HIT system of FIG. 8, according to one aspect of the present disclosure.

Detailed Description

In the following detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth in order to provide a thorough understanding of various principles of the disclosure. However, it will be apparent to one having ordinary skill in the art having had the benefit of the present disclosure that the present disclosure may be practiced in other embodiments that depart from the specific details disclosed herein. Moreover, descriptions of well-known devices, methods and materials may be omitted so as not to obscure the description of the various principles of the present disclosure. Finally, wherever applicable, like reference numerals refer to like elements.

Unless expressly stated otherwise, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Thus, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This applies to any possible non-explicit basis for interpretation, including: logic issues regarding the arrangement of steps or operational flow; simple meaning derived from grammatical organization or punctuation; the number or type of embodiments described in the specification.

As used herein, the term "and/or," when used in a list of two or more items, means that any one of the listed items can be used alone, or any combination of two or more of the listed items can be used. For example, if a composition is described as containing components A, B and/or C, the composition may contain a alone; b alone; c alone; a combination of A and B; a combination of A and C; b and C in combination; or a combination of A, B and C.

Modifications of the disclosure will occur to those skilled in the art and to those who make or use the disclosure. Therefore, it is to be understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and are not intended to limit the scope of the disclosure, which is defined by the following claims as interpreted according to the principles of patent law, including the doctrine of equivalents.

As used herein, the term "about" means that amounts, dimensions, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. When the term "about" is used to describe a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to. Whether or not the numerical values or range endpoints in the specification recite "about," the numerical values or range endpoints are intended to include two embodiments: one modified with "about" and one not. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

The stress distribution reported herein is determined using a combination of techniques. The stress profiles reported herein were measured by a Refractive Near Field (RNF) method, where the Central Tension (CT) is similar to the CT measurement provided by scattering polarimetry using scapp-5 manufactured by isaniia Glasstress, inc. The RNF data do not always accurately provide stress information from the first-2 μm from the sample surface, so the RNF data are extrapolated to the surface. Stress at the surface (CS) was measured by a FSM-6000LE surface stress meter from Orihara, Japan. The stress distribution near the center reflects the measurements obtained using RNF, while the stress distribution near the surface reflects the data obtained from FSM-6000LE measurements. In this way, the two measurement techniques are combined to form a representation of the overall stress distribution of the article from the surface to the center of the article. Typically, the stress distribution reported herein measured using a FSM-6000LE instrument is reported at a wavelength of 589 nm. However, different wavelengths may be used depending on the thickness of the potassium layer at the sample surface. The ion exchanged glass of the present disclosure includes a spike region near the surface and a tail region that extends into the interior of the glass. As used herein, compressive stress is represented by stress values greater than 0 (positive values "+"), while tensile stress is represented by stress values less than 0 (negative values "-").

As used herein, Central Tension (CT) is the stress at the center of the glass, which is either a compressive stress or a tensile stress.

As used herein, surface stress and stress at surface (CS) are used interchangeably to refer to the stress measured at the surface of the glass. Surface stress (CS) may provide an estimate of surface compression, which may be related to the amount of stress applied to the surface of the article to cause glass failure.

As used herein, depth of layer (DOL)_k) Refers to the depth of the peak region in the stress distribution, which is related to the ion diffusion depth near the peak.

As used herein, inflection stress (CS)_k) Is the stress at the asymptotic extrapolation of the peak region of the stress distribution and the tail region of the stress distribution. Inflection stress (CS)_k) Which may be compressive or tensile.

As used herein, depth of compression (DOC) refers to the location where the internal stress in the glass is first zero and changes from compression (+) to tension (-) or vice versa.

As used herein, the terms "frangible" and "frangibility" are used to refer to those modes of severe or energetic breakage of a chemically strengthened glass article without any external constraints (e.g., coatings, adhesive bonding layers) when impacted by a sharp object. As used herein, the term "non-brittle" refers to glasses that do not exhibit brittle characteristics, i.e., they do not exhibit severe or high energy fragmentation when impacted by a sharp object.

As used herein, the term "ion-exchangeable" means that the glass is capable of exchanging cations located at or near the surface of the glass with cations of the same valence state. The term "ion exchange" is used interchangeably with the terms "treatment" or "process" to refer to the act of treating glass in a manner that causes cations located at or near the surface of the glass to exchange with cations in the same valence state.

Unless otherwise specified, the concentrations of the constituent components of the glass are expressed in weight percent (wt%) on an oxide basis, unless otherwise specified. As used herein, the term "about" with respect to the concentrations of the constituent components is intended to encompass values within ± 0.2 wt%.

The presently illustrated embodiments are generally directed to glasses and glass articles including a compressive stress region having a surface stress (CS) greater than about 900MPa (compressive), and methods of forming such glasses. Accordingly, the article components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Further, like numerals in the specification and drawings denote like elements.

In this document, relational terms such as "first" and "second," "top" and "bottom," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by "comprising … …" does not, without further constraint, exclude the presence of additional identical elements in a process, method, article, or apparatus that comprises the element.

Embodiments of the present disclosure generally relate to a glass chemically strengthened using an ion exchange process comprising at least two ion exchange steps configured to provide the glass with a stress profile suitable for meeting safety standards for automotive applications. In addition, the glass articles of the present disclosure may have a sufficiently high surface stress (CS) and depth of stress distribution to meet automotive safety standards for glass, such as the Head Impact Test (HIT).

In order to meet automotive safety standards, such as the Head Impact Test (HIT), the glass must generally have a high surface stress (CS). Ion exchange is one example of a process that can be used to chemically strengthen glass. In a typical ion exchange process, the glass is placed in an ion exchange bath that includes a source of alkaline cations that can be exchanged for the smaller alkaline cations within the glass. Ion exchange between the glass and the bath can produce a layer near the surface of the glass that is under compressive stress and extends to a depth in the glass. The high surface stress (CS) required for automotive applications may limit the number of cycles that an ion exchange bath can be used to chemically strengthen the glass to provide a glass with a desired stress profile. Embodiments of the present disclosure provide a method by which ion exchange baths may be used in multiple cycles (e.g., as in a manufacturing operation) to produce glass having a desired stress profile before the ion exchange bath needs to be changed or regenerated.

In accordance with embodiments of the present disclosure, a glass article may include a compressive stress region having a surface stress greater than about 900MPa (compressive), a spike region extending from a surface of the glass into the body, and a tail region extending between the spike region and a center of the glass. In one embodiment, the peak and tail regions of the stress distribution may be obtained by a multi-step ion exchange process. In one example, the multi-step ion exchange process includes a first ion exchange step and a second ion exchange step.

Fig. 1 illustrates a schematic cross-sectional view of a chemically strengthened glass article 10 according to an embodiment of the present disclosure. The glass article 10 comprises a glass having a thicknessA glass body 12 of degree ("Th"), a first major surface 14, and a second major surface 16. The glass article 10 may be treated in an ion exchange process to chemically strengthen the glass article 10 and generate a stress distribution within the glass body 12. Glass article 10 may include a first compressive stress region 20 extending to a depth d relative to first major surface 14₁A first depth of compression (DOC) 22. In some embodiments, glass article 10 may also have a second compressive stress region 30 extending to a depth d relative to second major surface 16₂And a second depth of compression (DOC) 32. The glass article 10 may also include a central tensile stress region 40 extending between the first and second compressive stress regions 20 and 30, respectively, and a center or midpoint 42 at the center of the glass body 12.

Glass articles 10 described herein may have a stress profile including a first compressive stress region 20 and a second compressive stress region 30 that vary with respect to a corresponding depth in first and second major surfaces 14 and 16, respectively. While aspects of the present disclosure are discussed in the context of stress profiles extending from a single major surface 14 of glass article 10, it should be understood that glass article 10 may have a stress profile extending from second major surface 16 of glass article 10 that is similar to the stress profile extending from first major surface 14. For example, for the exemplary embodiment of fig. 1, first and second major surfaces 14 and 16, respectively, may have substantially identical first and second stress profiles extending from their respective surfaces. In another example, glass article 10 can have different stress profiles extending from first major surface 14 and second major surface 16.

The glass article 10 can have any suitable dimensions. In some embodiments, the thickness Th of the glass article 10 is about 0.2mm to about 1.3 mm. For example, the thickness Th may be about 0.2mm to about 1.3mm, about 0.2mm to about 1.2mm, about 0.2mm to about 1.1mm, about 0.2mm to about 1.0mm, about 0.2mm to about 0.9mm, about 0.2mm to about 0.8mm, about 0.2mm to about 0.7mm, about 0.2mm to about 0.6mm, about 0.2mm to about 0.5mm, about 0.5mm to about 1.3mm, about 0.5mm to about 1.2mm, about 0.5mm to about 1.1mm, about 0.5mm to about 1.0mm, about 0.5mm to about 0.9mm, about 0.5mm to about 0.8mm, about 0.8mm to about 1.3mm, about 0.8mm to about 1.2mm, about 0.8mm to about 1.9 mm, about 0.9mm to about 0.8mm, about 0.9mm to about 1.9 mm, about 0.9mm, about 0mm to about 1.2mm, about 0.8mm, about 0mm to about 1.9 mm, or about 1 mm. For example, thickness Th of glass article 10 may be about 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, and all thickness values in between the foregoing. Although the glass article 10 is illustrated as a planar article, such as a sheet or plate, it should be understood that the glass article 10 may be curved and/or have any desired 3-dimensional shape or size.

Fig. 2 schematically illustrates an exemplary stress profile 100 of an article 10 according to an embodiment of the present disclosure. The x-axis is shown as a normalized position (z/Th), where the overall thickness Th of the body 12 is Th, and the particular position or depth within the article 10 is given by z. The normalized position is determined as the distance from the first major surface 14 divided by the total thickness Th of the body 12 (e.g., normalized position 0.5 corresponds to the center 42 of the body 12). The stress distribution 100 shown in fig. 2 corresponds to a first portion of the glass body 12 that extends from the first major surface 14 (normalized position 0) to the center 42 of the body 12 (normalized position 0.5). It is to be understood that the stress profile 100 can optionally include a second portion extending from the center 42 of the glass body 12 to the second major surface 16 that is substantially a mirror image of the stress profile 100 shown at 0 to 0.5 (normalized position).

The stress profile 100 has a maximum compressive stress, also referred to as a surface stress (CS), at the first major surface 14 that is greater than about 900MPa (compression). In some embodiments, the surface stress (CS) may be greater than about 900MPa, greater than about 925MPa, greater than about 950MPa, greater than about 975MPa, greater than about 1000MPa, greater than about 1025MPa, greater than about 1050MPa, greater than about 1075MPa, greater than about 1100MPa, greater than about 1125MPa, or greater than about 1150MPa (compression). For example, the surface stress (CS) may be from about 900MPa to about 1200MPa, from about 900MPa to about 1175MPa, from about 900MPa to about 1160MPa, from about 900MPa to about 1155MPa, from about 900MPa to about 1150MPa, from about 900MPa to about 1100MPa, from about 900MPa to about 1075MPa, from about 900MPa to about 1050MPa, from about 900MPa to about 1000MPa, from about 950MPa to about 1200MPa, from about 950MPa to about 1175MPa, from about 950MPa to about 1160MPa, from about 950MPa to about 1155MPa, from about 950MPa to about 1150MPa, from about 950MPa to about 1100MPa, from about 950MPa to about 1075MPa, from about 950MPa to about 1050MPa, from about 950MPa to about 1000MPa, from about 1000MPa to about 1200MPa, from about 1000MPa to about 1175MPa, from about 1000MPa to about 1160MPa, from about 1000MPa to about 1155MPa, from about 1050MPa to about 1150MPa, from about 1050MPa to about 1160MPa, from about 1000MPa to about 1100MPa, from about 1175MPa, from about 1050MPa to about 1160MPa, from about 1000MPa, from about 1050MPa to about 1200MPa, from about 1050MPa to about 1160MPa, from 1050MPa, from about 1100MPa, from 1050MPa to about 1200MPa, from 1050MPa, from about 1000MPa to about 1000MPa, from about 1000MPa to about 1200MPa, from about 1175MPa, from about 1000MPa, from 1050MPa to about 1100MPa, from about 1000MPa to about 1100MPa, from about 10MPa, from 1050MPa to about 10MPa to about 1200MPa, from 1050MPa, from the center, Or from about 1100MPa to about 1175MPa (compressed). In some examples, the surface stress (CS) may be about 900MPa, about 925MPa, about 926MPa, about 950MPa, about 957MPa, about 975MPa, about 1000MPa, about 1025MPa, about 1026MPa, about 1050MPa, about 1066MPa, about 1075MPa, about 1095MPa, about 1100MPa, about 1125MPa, about 1130MPa, about 1150MPa, about 1155MPa, about 1160MPa, about 1175MPa, about 1200MPa, or any surface stress (compressive stress) between these values.

The stress distribution 100 may include a spike region 102 and a tail region 104. The spike region 102 extends from the first major surface 14 to a depth of layer (DOL) corresponding to the depth of ion diffusion caused by the ion exchange process_k). Tail region 104 from depth of layer (DOL)_k) Extending through the center 42 of the glass body 12 (normalized position 0.5). Depth of layer (DOL)_k) And may be greater than about 10 μm. In some embodiments, depth of layer (DOL)_k) Can be greater than about 10 μm, greater than about 15 μm, or greater than about 20 μm. For example, depth of layer (DOL)_k) Can be about 10 μm to about 50 μm, about 10 μm to about 40 μm, about 10 μm to about 30 μm, about 10 μm to about 25 μm, about 10 μm to about 20 μm, about 15 μm to about 50 μm, about 15 μm to about 40 μm, about 15 μm to about 30 μm, about 15 μm to about 25 μm, about 15 μm to about 20 μm, about 20 μm to about 50 μm, about 20 μm to about 40 μm, about 20 μm to about 30 μm, or about 20 μm to about 25 μm. In some examples, depth of layer (DOL)_k) May be about 10 μm, about 12 μm, about 15 μm, about 16 μm, about 17 μm, about 17.6 μm, about 18 μm, about 18.2 μm, about 19 μm, about 20 μm, about 20.4 μm, about 21 μm, about 22 μm, about 23 μm, about 24 μm, about 24.5 μm, about 25 μm, about 30 μm,about 40 μm, about 50 μm, or any depth between these values.

The spike region 102 and tail region 104 may have a knee stress (CS) of greater than about 50MPa (compression)_k) At the inflection region 106. The inflection region 106 is defined as the point where the asymptotic extrapolation of the spike region 102 and the tail region 104 intersect. According to one embodiment, Corner Stress (CS)_k) Can be greater than about 35MPa, greater than about 40MPa, greater than about 45MPa, greater than about 50MPa, greater than about 55MPa, greater than about 60MPa, greater than about 65MPa, greater than about 70MPa, greater than about 80MPa, greater than about 90MPa, or greater than about 100MPa (compressed). For example, the inflection point (CSk) stress may be about 35MPa to about 120MPa, about 35MPa to about 110MPa, about 35MPa to about 100MPa, about 35MPa to about 90MPa, about 35MPa to about 80MPa, about 35MPa to about 70MPa, about 35MPa to about 60MPa, about 35MPa to about 50MPa, about 40MPa to about 120MPa, about 40MPa to about 110MPa, about 40MPa to about 100MPa, about 40MPa to about 90MPa, about 40MPa to about 80MPa, about 40MPa to about 70MPa, about 40MPa to about 60MPa, about 40MPa to about 50MPa, about 50MPa to about 120MPa, about 50MPa to about 110MPa, about 50MPa to about 100MPa, about 50MPa to about 90MPa, about 50MPa to about 80MPa, about 50MPa to about 70MPa, about 60MPa to about 120MPa, about 60MPa to about 110MPa, about 60MPa to about 100MPa, about 60MPa, about 80MPa to about 80MPa, about 80MPa to about 100MPa, about 80MPa to about 80MPa, about 90MPa, about 40MPa to about 80MPa, about 90MPa to about 90MPa, From about 90MPa to about 120MPa, from about 90MPa to about 110MPa, from about 90MPa to about 100MPa, or from about 100MPa to about 120MPa (compressed). In some examples, the inflection point (CSk) stress is about 35MPa, about 40MPa, about 45MPa, about 50MPa, about 55MPa, about 60MPa, about 65MPa, about 70MPa, about 75MPa, about 80MPa, about 85MPa, about 90MPa, about 95MPa, about 100MPa, about 105MPa, about 110MPa, about 115MPa, about 120MPa (compressive), or any stress value in between these values.

According to one aspect of the present disclosure, the spike region 102 may have a slope that is steeper than about-30 MPa/μm. As used herein, the term "steeper" with respect to the slope is used to indicate that the absolute value of the slope is greater in comparison; that is, the slope of the line is greater in magnitude relative to another value. The phrase "less steep" is used herein in relation to a slope to indicate that the absolute value of the slope is small in comparison; that is, the slope of the line is small in magnitude relative to another value. According to one embodiment, the spike region 102 has a steeper slope than about-30 MPa/μm, about-35 MPa/μm, about-40 MPa/μm, about-45 MPa/μm, about-50 MPa/μm, about-55 MPa/μm, or about-60 MPa/μm. For example, the spike region 102 may have a peak area of about-30 MPa/μm to about-70 MPa/μm, about-30 MPa/μm to about-65 MPa/μm, about-30 MPa/μm to about-60 MPa/μm, about-30 MPa/μm to about-55 MPa/μm, about-35 MPa/μm to about-70 MPa/μm, about-35 MPa/μm to about-65 MPa/μm, about-35 MPa/μm to about-60 MPa/μm, about-35 MPa/μm to about-55 MPa/μm, about-40 MPa/μm to about-70 MPa/μm, about-40 MPa/μm to about-65 MPa/μm, about-40 MPa/μm to about-60 MPa/μm, A slope of about-40 MPa/μm to about-55 MPa/μm, about-50 MPa/μm to about-70 MPa/μm, about-50 MPa/μm to about-65 MPa/μm, or about-50 MPa/μm to about-60 MPa/μm.

The tail region 104 may have a slope measured between the inflection region 106 and the depth of compression (DOC)22 that is less steep than the spike region 102. In some embodiments, the slope of the tail region 104 is steeper than about (241)/(Th) in MPa/μm, where Th is the thickness of the glass body 12 in μm. The expression for the slope of the tail region 104 is determined by having a stress of about 20MPa near the inflection point and a DOC of about 100 μm. For example, for a sample having a thickness Th of 1100 μm, an exemplary slope of the tail region 104 would be about 0.22MPa/μm. In some examples, the slope of the tail region 104 may be steeper than about (241)/(Th), steeper than about (100)/(Th), or steeper than about (50)/(Th).

With a stress of 0 within the glass body 12, the glass article 10 has a depth of compression (DOC)22 of greater than or equal to about 0.16 x (Th), where Th is the thickness of the glass body 12. For example, for a glass article 10 having a thickness Th of about 1100 μm, the depth of compression (DOC)22 may be about 150 μm to about 200 μm, about 160 μm to about 200 μm, about 170 μm to about 200 μm, about 180 μm to about 200 μm, or about 190 μm to about 200 μm. For parabolic stress profiles, the maximum depth of compression (DOC)22 is typically about 0.2115 x (Th), which is at least partially based on the two sides of the stress profile being the same. As the stress profile with the spike region 102 changes, the maximum depth of compression (DOC)22 may decrease to less than about 0.21 x (Th). In some examples, the maximum DOC may be reduced to about 0.18 x (Th) or about 0.19 x (Th) based at least in part on the spike region 102. Without being bound by any theory, it is believed that a DOC having ≧ about 0.16 (Th) may provide the glass article 10 with the desired drop performance. In some aspects, the depth of compression (DOC)22 may be ≧ 0.16 (Th),. gtoreq.0.18 (Th),. gtoreq.0.19 (Th), or ≧ 0.20 (Th). For example, the compression Depth (DOC)22 may be about 0.16 to about 0.2115, about 0.16 to about 0.21, about 0.16 to about 0.20, about 0.16 to about 0.2115, about 0.17 to about 0.21, about 0.17 to about 0.17, about 0.17 to about 0.20, about 0.17 to about 0.2115, about 0.18 to about 0.20, about 0.17 to about 0.19, about 0.18 to about 0.2115, about 0.18 to about 0.21, about 0.19 to about 0.19, about 0.19 to about 360 to about 3619, about 0.19 to about 360, about 0 to about 360.19, about 0 to about 19, about 0.19 to about 360.19.

A first compressive stress region 20 of the glass article 10 may extend from the first major surface 14 to a first depth of compression (DOC) 22. The tensile stress region 40 may extend from the first depth of compression (DOC)22 through at least a center 42 of the glass body 12. The glass article 10 may have a Central Tension (CT), i.e., a tensile stress at the center 42 (normalized position 0.5) of the glass body 12, of greater than about 40MPa (tensile). In some examples, the Central Tension (CT) is greater than about 40MPa, greater than about 45MPa, greater than about 50MPa, greater than about 55MPa, greater than about 60MPa, or greater than about 65MPa (tensile). For example, the Central Tension (CT) can be about 40MPa to about 70MPa, about 40MPa to about 65MPa, about 40MPa to about 60MPa, about 40MPa to about 50MPa, about 45MPa to about 70MPa, about 45MPa to about 65MPa, about 45MPa to about 55MPa, about 50MPa to about 70MPa, about 50MPa to about 65MPa, about 50MPa to about 60MPa, or about 60MPa to about 70 MPa.

According to one aspect of the present disclosure, the chemically strengthened glass articles described herein may be non-frangible. The non-frangible glass article of the present disclosure can have a Center Tension (CT) according to formula (I):

CT<((E/(68GPa))*(75MPa)*(1mm)^0.5)/(Th)^0.5 (I)

where E is the Young's modulus of the glass body 12, measured in GPa; th is the thickness of the glass body 12, measured in mm. Without wishing to be bound by any theory, the composition has a composition comprising about 64 mol% SiO₂、16mol％Al₂O₃、11mol％Na₂O、6.25mol％Li₂O、1mol％TiO₂、0.04mol％SnO₂And 2.5 mol% P₂O₅The young's modulus E of a representative aluminosilicate glass of composition (a) is about 68GPa, and the glass is experimentally found to have a brittleness limit of about 75 MPa. The brittleness limit was found to be roughly inversely proportional to the square root of the glass thickness and to vary linearly with the young's modulus E of the glass. By normalizing these relationships to apply to glasses having different thicknesses and/or young's moduli E, equation (I) is obtained.

The glass article of the present disclosure (e.g., glass article 10 shown in fig. 1) may include any suitable glass that may be chemically strengthened in an ion exchange process that converts potassium ions (K)⁺) Exchanged for smaller cations present in the glass. Without being bound by any theory, the glass articles of the present disclosure may be chemically strengthened in an ion exchange process, wherein ions at or near the surface of the glass are replaced (also referred to as exchanged) with larger ions, which generally have the same valence or oxidation state. According to one embodiment, the chemically strengthened glass disclosed herein can be formed by treating an alkali aluminosilicate glass comprising lithium in an ion exchange process to produce a desired stress profile as described herein. Non-limiting examples of glasses suitable for treatment according to the present disclosure include compositions comprising, among other components, SiO in the range of about 55 mol% to about 75 mol%₂B in an amount ranging from about 0 mol% to about 10 mol%₂O₃Al in an amount ranging from about 10 mol% to about 25 mol%₂O₃Na in an amount ranging from about 0 mol% to about 15 mol%₂O, K in an amount ranging from about 0 mol% to about 4 mol%₂O, LiO in the range of about 0 mol% to about 15 mol% (or about 5 mol% to about 12 mol%)₂MgO in an amount ranging from about 0 mol% to about 7 mol%, about 0 mol% to about 2moZnO in an amount ranging from l%, CaO in a range from about 0 mol% to about 2 mol%, SnO in a non-zero amount ranging from about 1 mol%₂And P in an amount ranging from about 0 mol% to about 4 mol%₂O₅. Unless otherwise indicated, the glass compositions disclosed herein are described in terms of mole percent (mol%) based on oxide analysis.

In one or more embodiments, the glass composition may include SiO in an amount in the range of about 66 mol% to about 80 mol%, about 67 mol% to about 80 mol%, about 68 mol% to about 80 mol%, about 69 mol% to about 80 mol%, about 70 mol% to about 80 mol%, about 72 mol% to about 80 mol%, about 65 mol% to about 78 mol%, about 65 mol% to about 76 mol%, about 65 mol% to about 75 mol%, about 65 mol% to about 74 mol%, about 65 mol% to about 72 mol%, or about 65 mol% to about 70 mol%, and all ranges and subranges therebetween₂。

In one or more embodiments, the glass composition includes Al in an amount greater than about 4 mol% or greater than about 5 mol%₂O₃. In one or more embodiments, the glass composition includes Al in the range of about 7 mol% to about 20 mol%, about 7 mol% to about 19 mol%, about 7 mol% to about 18 mol%, about 7 mol% to about 17 mol%, about 7 mol% to about 16 mol%, about 7 mol% to about 15 mol%, about 7 mol% to about 14 mol%, about 7 mol% to about 13 mol%, about 4 mol% to about 12 mol%, about 7 mol% to about 11 mol%, about 8 mol% to about 20 mol%, 9 mol% to about 20 mol%, about 10 mol% to about 20 mol%, about 11 mol% to about 20 mol%, about 12 mol% to about 20 mol%, about 11 mol% to about 18 mol%, or about 13 mol% to about 17 mol%, and all ranges and subranges therebetween₂O₃. In one or more embodiments, Al₂O₃The upper limit of (b) may be about 16 mol%, 16.2 mol%, 16.4 mol%, 16.6 mol%, or 16.8 mol%.

In one or more embodiments, the glass article is described as an aluminosilicate glass article or includes an aluminosilicate glass composition. In such embodiments, the glass composition or article formed therefrom comprises SiO₂And Al₂O₃And is not a soda-lime-silicate glass. In this respect, glassThe glass composition or articles formed therefrom include Al in an amount of about 2 mol% or greater, 2.25 mol% or greater, 2.5 mol% or greater, about 2.75 mol% or greater, about 3 mol% or greater₂O₃。

In one or more embodiments, the glass composition includes B₂O₃(e.g., about 0.01 mol% or greater). In one or more embodiments, the glass composition comprises from about 0 mol% to about 10 mol%, from about 0 mol% to about 9 mol%, from about 0 mol% to about 8 mol%, from about 0 mol% to about 7 mol%, from about 0 mol% to about 6 mol%, from about 0 mol% to about 5 mol%, from about 0 mol% to about 4 mol%, from about 0 mol% to about 3 mol%, from about 0 mol% to about 2 mol%, from about 0 mol% to about 1 mol%, from about 0 mol% to about 0.5 mol%, from about 0.1 mol% to about 10 mol%, from about 0.1 mol% to about 9 mol%, from about 0.1 mol% to about 8 mol%, from about 0.1 mol% to about 7 mol%, from about 0.1 mol% to about 6 mol%, from about 0.1 mol% to about 5 mol%, from about 0.1 mol% to about 4 mol%, from about 0.1 mol% to about 3 mol%, from about 0.1 mol% to about 2 mol%, from about 0.1 mol% to about 1 mol%, from about 0.1 mol% to about 0.5 mol% range, and all ranges and subranges therebetween.₂O₃. In one or more embodiments, the glass composition is substantially free of B₂O₃。

As used herein, the phrase "substantially free" with respect to a component of a composition means that the component is not actively or intentionally added to the composition during initial compounding, but may be present as an impurity in an amount less than about 0.001 mol%.

In one or more embodiments, the glass composition may optionally include P₂O₅(e.g., about 0.01 mol% or greater). In one or more embodiments, the glass composition includes a non-zero amount of P₂O₅Up to and including 3 mol%, 2.5 mol%, 2 mol%, 1.5 mol%, 1 mol% or 0.5 mol%. In one or more embodiments, the glass composition is substantially free of P₂O₅。

In one or more embodiments, the glass composition may include a total amount of R of greater than or equal to about 8 mol%, greater than or equal to about 10 mol%, or greater than or equal to about 12 mol%₂O (which is an alkali metal oxide such as Li)₂O、Na₂O、K₂O、Rb₂O and Cs₂Total amount of O). In some embodiments, the glass composition includes a total amount of R in the range of about 8 mol% to about 20 mol%, about 8 mol% to about 18 mol%, about 8 mol% to about 16 mol%, about 8 mol% to about 14 mol%, about 8 mol% to about 12 mol%, about 9 mol% to about 20 mol%, about 10 mol% to about 20 mol%, about 11 mol% to about 20 mol%, about 12 mol% to about 20 mol%, about 13 mol% to about 20 mol%, about 10 mol% to about 14 mol%, or 11 mol% to about 13 mol%, and all ranges and subranges therebetween₂And O. In one or more embodiments, the glass composition may be substantially free of Rb₂O and/or Cs₂And O. In one or more embodiments, R₂O may include only Li₂O、Na₂O and K₂The total amount of O. In one or more embodiments, the glass composition may include at least one selected from Li₂O、Na₂O and K₂An alkali metal oxide of O, wherein the alkali metal oxide is present in an amount greater than about 8 mol% or greater.

In one or more embodiments, the glass composition includes Na in an amount of greater than or equal to about 8 mol%, greater than or equal to about 10 mol%, or greater than or equal to about 12 mol%₂And O. In one or more embodiments, the composition includes Na from about 8 mol% to about 20 mol%, from about 8 mol% to about 18 mol%, from about 8 mol% to about 16 mol%, from about 8 mol% to about 14 mol%, from about 8 mol% to about 12 mol%, from about 9 mol% to about 20 mol%, from about 10 mol% to about 20 mol%, from about 11 mol% to about 20 mol%, from about 12 mol% to about 20 mol%, from about 13 mol% to about 20 mol%, from about 10 mol% to about 14 mol%, or from 11 mol% to about 16 mol%, and all ranges and subranges therebetween₂O。

In one or more embodiments, the glass composition includes less than about 4 mol%, less than about 3 mol%, or less than about 1 mol% of K₂And O. In some cases, the glass composition may include from about 0 mol% to about 4 mol%, from about 0 mol% to about 3.5 mol%, from about 0 mol% to about 3 mol%, from about 0 mol% to about 2.5 mol%, from about 0 mol% to about 2 mol%, from about 0 mol% to about 1.5 mol%, or a combination thereof,About 0 mol% to about 1 mol%, about 0 mol% to about 0.5 mol%, about 0 mol% to about 0.2 mol%, about 0 mol% to about 0.1 mol%, about 0.5 mol% to about 4 mol%, about 0.5 mol% to about 3.5 mol%, about 0.5 mol% to about 3 mol%, about 0.5 mol% to about 2.5 mol%, about 0.5 mol% to about 2 mol%, about 0.5 mol% to about 1.5 mol%, or about 0.5 mol% to about 1 mol% range, and all ranges and subranges therebetween, an amount of K₂And O. In one or more embodiments, the glass composition may be substantially free of K₂O。

In one or more embodiments, the glass composition is substantially free of Li₂And O. In one or more embodiments, Na is present in the composition₂The amount of O may be greater than Li₂The amount of O. In some cases, Na₂The amount of O may be greater than Li₂O and K₂The combined amount of O. In one or more alternative embodiments, Li in the composition₂The amount of O may be greater than Na₂Amount of O or Na₂O and K₂The combined amount of O. In one or more embodiments, the glass composition can include RO (which is the total of alkaline earth oxides such as CaO, MgO, BaO, ZnO, and SrO) in a total amount in a range from about 0 mol% to about 6 mol%. In some embodiments, the glass composition includes a non-zero amount of RO, which is up to about 6 mol%. In one or more embodiments, the glass composition includes RO in an amount from about 0 mol% to about 5 mol%, from about 0 mol% to about 4 mol%, from about 0 mol% to about 3 mol%, from about 0 mol% to about 2 mol%, from about 0 mol% to about 1.5 mol%, from about 0 mol% to about 1 mol%, from about 0 mol% to about 0.8 mol%, from about 0 mol% to about 0.5 mol%, and all ranges and subranges therebetween.

In one or more embodiments, the glass composition includes CaO in an amount less than about 2 mol%, less than about 1.5 mol%, less than about 1 mol%, less than about 0.8 mol%, or less than about 0.5 mol%. In one or more embodiments, the glass composition is substantially free of CaO.

In some embodiments, the glass composition comprises MgO in an amount from about 0 mol% to about 7 mol%, from about 0 mol% to about 6 mol%, from about 0 mol% to about 5 mol%, from about 0 mol% to about 4 mol%, from about 0.1 mol% to about 7 mol%, from about 0.1 mol% to about 6 mol%, from about 0.1 mol% to about 5 mol%, from about 0.1 mol% to about 4 mol%, from about 1 mol% to about 7 mol%, from about 2 mol% to about 6 mol%, or from about 3 mol% to about 6 mol%, and all ranges and subranges therebetween.

In one or more embodiments, the glass composition includes ZrO in an amount less than or equal to about 0.2 mol%, less than about 0.18 mol%, less than about 0.16 mol%, less than about 0.15 mol%, less than about 0.14 mol%, less than about 0.12 mol%₂. In one or more embodiments, the glass composition includes ZrO in an amount of about 0.01 mol% to about 0.2 mol%, about 0.01 mol% to about 0.18 mol%, about 0.01 mol% to about 0.16 mol%, about 0.01 mol% to about 0.15 mol%, about 0.01 mol% to about 0.14 mol%, about 0.01 mol% to about 0.12 mol%, or about 0.01 mol% to about 0.10 mol% range, and all ranges and subranges therebetween₂。

In one or more embodiments, the glass composition includes SnO in an amount of less than or equal to about 0.2 mol%, less than about 0.18 mol%, less than about 0.16 mol%, less than about 0.15 mol%, less than about 0.14 mol%, less than about 0.12 mol%₂. In one or more embodiments, the glass composition includes SnO in a range of about 0.01 mol% to about 0.2 mol%, about 0.01 mol% to about 0.18 mol%, about 0.01 mol% to about 0.16 mol%, about 0.01 mol% to about 0.15 mol%, about 0.01 mol% to about 0.14 mol%, about 0.01 mol% to about 0.12 mol%, or about 0.01 mol% to about 0.10 mol%, and all ranges and subranges therebetween₂。

In one or more embodiments, the glass composition can include an oxide that imparts a color or tint to the glass article. In some embodiments, the glass composition includes an oxide that prevents the glass article from discoloring when the glass article is exposed to ultraviolet radiation. Examples of such oxides include, but are not limited to: oxides of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ce, W and Mo.

In one or more embodiments, the glass composition includes Fe₂O₃Expressed Fe, wherein Fe is present in an amount up to (and including) about 1 mol%. In some embodiments, the glass composition is substantially free of Fe. In one or more embodiments, the glassThe composition includes Fe in an amount equal to or less than about 0.2 mol%, less than about 0.18 mol%, less than about 0.16 mol%, less than about 0.15 mol%, less than about 0.14 mol%, less than about 0.12 mol%₂O₃. In one or more embodiments, the glass composition includes Fe in a range of about 0.01 mol% to about 0.2 mol%, about 0.01 mol% to about 0.18 mol%, about 0.01 mol% to about 0.16 mol%, about 0.01 mol% to about 0.15 mol%, about 0.01 mol% to about 0.14 mol%, about 0.01 mol% to about 0.12 mol%, or about 0.01 mol% to about 0.10 mol%, and all ranges and subranges therebetween₂O₃。

When the glass composition comprises TiO₂Of TiO 2₂May be present in an amount of about 5 mol% or less, about 2.5 mol% or less, about 2 mol% or less, or about 1 mol% or less. In one or more embodiments, the glass composition may be substantially free of TiO₂。

Exemplary glass compositions include SiO in an amount in the range of about 65 mol% to about 75 mol%₂Al in an amount in the range of about 8 mol% to about 14 mol%₂O₃Na in an amount ranging from about 12 mol% to about 17 mol%₂O, K in an amount ranging from about 0 mol% to about 0.2 mol%₂O, and MgO in an amount ranging from about 1.5 mol% to about 6 mol%. Optionally, SnO can be included in amounts other than those disclosed herein₂。

According to embodiments of the present disclosure, the elastic energy stored by the stress profile of the glass article of the present disclosure may be determined according to formula (II):

where v is the Poisson's ratio of glass, E is the Young's modulus of glass, and σ is the stress. Unless otherwise stated, the unit of stress σ is MPa (equivalent to 10)⁶N/m²). For a material having a composition including about 64 mol% SiO₂、16mol％Al₂O₃、11mol％Na₂O、6.25mol％Li₂O、1mol％TiO₂、0.04mol％SnO₂And 2.5 mol% P₂O₅A poisson ratio v of about 0.22 and a young's modulus E of about 68 GPa.

For a symmetrical stress distribution, the elastic energy (per unit area of glass) in the compressive stress region 20 can be determined according to equation (III), while the elastic energy (per unit area of glass) in the tensile stress region 40 from the depth of compression (DOC)22 to the center 42 of the glass body 12 can be determined according to equation (IV):

the factor "2" is used to account for the symmetry of the stress distribution (extending between the first and second major surfaces 14, 16), so it is necessary to calculate the integral for only the first half of the stress distribution (i.e., the stress distribution from the first major surface 14 to the center 42 of the glass body 12).

The total elastic energy stored in the glass body 12 may be represented by the sum of the elastic energy of the individual compressive stress region 20 and half of the tensile stress region 40 according to equation (V):

the elastic energy unit (per unit substrate) includes:

another measure is the elastic energy per unit substrate area per unit substrate thickness, which is measured in J/m²mm is expressed in units. The elastic energy per unit substrate area per unit substrate thickness is independent of the glass thickness and is effective for thicknesses in the range of about 50 μm to about 2000 μm.

In one embodiment, the brittleness criterion can be represented by normalized total energy, compressive energy, and tensile energy according to equations (VI), (VII), and (VIII), respectively, all of which are in MPa²m is a unit:

the normalized energy may be further normalized by the square root of the thickness (denoted as parameter "WT"). WT parameter has unit MPa²m^0.5And has a variable thickness component embedded therein. The normalized total energy, compressive energy, and tensile energy per thickness can be represented by equations (IX), (X), and (XI), respectively:

according to one embodiment of the present disclosure, the chemically strengthened glass articles described herein may be frangible. The frangible glass article of the present disclosure can have a Center Tension (CT) according to formula (XII):

CT>((E/(68GPa))*(75MPa)*(1mm)^0.5)/(Th)^0.5 (XII)

wherein E is the Young's modulus of the glass body 12, measured in GPa; th is the thickness of the glass body 12, measured in mm.

According to one embodiment, the non-brittle glass article of the present disclosure may have less than about 20J/m²Elastic tensile energy ofIn some examples, the non-frangible glass article of the present disclosure can have about 10J/m²To about 20J/m²About 10J/m²To about 18J/m²About 12J/m²To about 20J/m²About 12J/m²To about 18J/m²About 14J/m²To about 20J/m²About 14J/m²To about 18J/m²About 16J/m²To about 20J/m²、16J/m²To about 18J/m²Or about 18J/m²To about 20J/m²Elastic tensile energy of

According to one embodiment, the non-brittle glass article of the present disclosure may have less than about 60MPa²m^0.5Normalized elastic tensile energy per thickness ofIn some examples, the non-frangible glass article of the present disclosure can have about 30MPa²m^0.5To about 60MPa²m^0.5About 30MPa of²m^0.5To about 50MPa²m^0.5About 30MPa of²m^0.5To about 40MPa²m^0.5About 40MPa, about²m^0.5To about 60MPa²m^0.5About 30MPa of²m^0.5To about 50MPa²m^0.5Or about 50MPa²m^0.5To about 60MPa²m^0.5Normalized elastic tensile energy per thickness of

FIG. 3 illustrates a method 200 of forming chemically strengthened glass according to an embodiment of the disclosure. Although the method 200 is described in the context of the exemplary glass article 10 of fig. 1, it should be understood that the method 200 may be used with other glasses to provide the glass with a desired stress profile. The method 200 includes a first ion exchange step 202 in which the glass article is immersed in a first molten salt bath that includes potassium metal ions and sodium metal ions. The potassium and sodium metal ions may each be provided individually as salts of nitrates, sulfates, chlorides, or combinations thereof. The salt bath is heated to a suitable temperature to generate a molten salt bath. Typical temperatures of the molten salt bath of potassium and sodium metal ions are in the range of about 380 ℃ to about 470 ℃. For example, the molten salt bath may be set at about 380 ℃, 390 ℃, 400 ℃, 410 ℃, 420 ℃, 430 ℃, 440 ℃, 450 ℃, 460 ℃, 470 ℃, and all molten salt bath temperatures between the foregoing temperatures.

The concentration of each of the potassium and sodium salts used to form the first molten salt bath, as well as the immersion or reaction time period (i.e., the time period during which the glass article is immersed in the salt bath), may vary based at least in part on the desired stress profile to be formed in the glass.

According to one embodiment, the first molten salt bath includes about 80% by weight (wt%) of a potassium salt and about 20% of a sodium salt. In some examples, the first molten salt bath may include a potassium salt in an amount of about 70 wt% to about 90 wt%, about 70 wt% to about 85 wt%, about 70 wt% to about 80 wt%, about 75 wt% to about 90 wt%, about 75 wt% to about 85 wt%, about 75 wt% to about 80 wt%, about 78 wt% to about 90 wt%, about 78 wt% to about 85 wt%, about 78 wt% to about 80 wt%, about 80 wt% to about 90 wt%, about 80 wt% to about 85 wt%, about 82 wt% to about 90 wt%, or about 82 wt% to about 85 wt%, with the balance made up of a sodium salt.

The first ion exchange step 202 may include a first reaction time period that is typically greater than about 1 hour and less than about 10 hours. In some embodiments, the first reaction time period of the first ion exchange step 202 may be about 1 hour to about 10 hours, about 1 hour to about 8 hours, about 1 hour to about 6 hours, about 1 hour to about 4 hours, about 2 hours to about 10 hours, about 2 hours to about 8 hours, about 2 hours to about 6 hours, about 2 hours to about 4 hours, about 4 hours to about 10 hours, about 4 hours to about 8 hours, about 4 hours to about 6 hours, about 6 hours to about 10 hours, or about 6 hours to about 8 hours. For example, the first reaction time period of the first ion exchange step 202 may be about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 9 hours, about 10 hours, or any time period in between these values. In one exemplary embodiment, the first reaction time period may be about 6 hours.

After the first ion exchange step 202, the glass article may be treated in a second ion exchange step 204. The second ion exchange step 204 may include immersing the glass article in a second molten salt bath including potassium metal ions. In accordance with embodiments of the present disclosure, the second ion exchange step 204 is adapted to form a compressive stress region in the glass article having a surface stress (CS) greater than about 900MPa (compressive). The potassium metal ions may be provided as salts of nitrates, sulfates, chlorides, or combinations thereof. Typical temperatures of the molten salt bath of potassium metal ions are in the range of about 380 ℃ to about 470 ℃. The concentration of the potassium salt used to form the second molten salt bath, as well as the immersion or reaction time (i.e., the time the glass article is immersed in the salt bath), may vary based at least in part on the desired stress profile to be formed in the glass article, including the desired characteristics of the compressive stress region. In one embodiment, the initial concentration of potassium salt in the second molten salt bath is about 100 wt%.

The second reaction time period can be selected to provide the glass article with a compressive stress region having desired characteristics, including a surface stress (CS) greater than about 900MPa (compression). The second reaction time period may also be selected to provide additional desired characteristics of the compressive stress region, such as a desired depth of layer (DOL)_k) Desired knee stress (CS)_k) And/or the slope of the peak region of the desired stress profile. In one embodiment, the second reaction time period is from about 0.5 hours to about 4 hours. For example, the second reaction time period can be about 0.5 hours to about 4 hours, about 0.5 hours to about 3 hours, about 0.5 hours to about 2 hours, about 0.5 hours to about 3 hoursAbout 1 hour, about 0.75 hour to about 4 hours, about 0.75 hour to about 3 hours, about 0.75 hour to about 2 hours, about 0.75 hour to about 1 hour, about 1 hour to about 4 hours, about 1 hour to about 3 hours, or about 1 hour to about 2 hours. In one embodiment, the second reaction time period is about 0.5 hours. According to one embodiment, the second reaction period is shorter than the first reaction period.

According to one aspect of the present disclosure, the first ion exchange step 202 using a given first molten salt bath and the second ion exchange step 204 using a given second molten salt bath may be repeated for a plurality of ion exchange cycles to treat a plurality of glass articles prior to replacing and/or regenerating the first and/or second molten salt baths. As used herein, the term "cycle" is used to describe an ion exchange process, referring to the treatment of a given glass article in a first ion exchange step 202 followed by treatment in a second ion exchange step 204.

Without wishing to be bound by any particular theory, the composition of the first molten salt bath in the first ion exchange step 202 and the second molten salt bath in the second ion exchange step 204, respectively, may vary for each ion exchange cycle. For example, as lithium ions within the glass exchange with sodium or potassium ions in the molten salt bath, the lithium ion concentration in the molten salt bath increases, which may be referred to as "lithium poisoning". As the amount of lithium poisoning in the first and/or second molten salt bath increases, the ability of method 200 to provide a glass having a desired stress profile may decrease. If the level of lithium poisoning increases too quickly, i.e., within too few ion exchange cycles, it may be difficult to chemically strengthen the glass using method 200 in a manner suitable for manufacturing. For example, for a given set of ion exchange processing parameters, the surface stress (CS) obtainable in the glass article decreases as the amount of lithium poisoning in the first and/or second molten salt bath increases. Over time, the surface stress (CS) obtainable by the ion exchange process may no longer meet the minimum required surface stress (CS).

According to one aspect, the first ion exchange step 202 and/or the second ion exchange step 204 may be adjusted such that the second ion exchange step creates a surface stress(CS) a compressive stress region greater than about 900MPa (compression) and such that the amount of increase in surface stress of the glass article in the second ion exchange step 204 decreases by less than a predetermined amount per ion exchange cycle. In one aspect, the first ion exchange step 202 and/or the second ion exchange step 204 may be adjusted such that 0.0228m per kilogram potassium salt in the second molten salt bath²The surface area of the glass article is loaded and the increase in the surface stress of the glass article in the second ion exchange step 204 decreases by less than about 6MPa per ion exchange cycle. For example, 0.0228m per kg potassium salt in the second molten salt bath²The surface area of the glass article can be reduced by an amount that increases the surface stress of the glass article per ion exchange cycle by less than about 6MPa, less than about 5.5MPa, less than about 5MPa, less than about 4.5MPa, less than about 4MPa, less than about 3.5MPa, less than about 3MPa, less than about 2.5MPa, less than about 2MPa, less than about 1.5MPa, or less than about 1 MPa. According to another aspect, the first ion exchange step 202 and/or the second ion exchange step 204 may be adjusted such that 0.0065m per kg potassium salt in the second molten salt bath²The surface area of the glass article is loaded and the increase in the surface stress of the glass article in the second ion exchange step 204 decreases by less than about 2MPa per ion exchange cycle. For example, 0.0065m per kg potassium salt in the second molten salt bath²The surface area of the glass article can be reduced by an amount that increases the surface stress of the glass article per ion exchange cycle by less than about 2MPa, less than about 1.75MPa, less than about 1.5MPa, less than about 1.25MPa, less than about 1MPa, less than about 0.75MPa, or less than about 0.5 MPa.

According to one aspect of the present disclosure, the first ion exchange step 202 and/or the second ion exchange step 204 may be adapted to provide the first glass article treated in the initial ion exchange cycle with a compressive stress region having an initial surface stress (CS) that satisfies a glass article minimum required surface stress (CS) based on the intended use of the glass article. The first ion exchange step 202 and/or the second ion exchange step 204 may also be adapted to allow a predetermined number of glass articles to be processed in a predetermined number of cycles while still providing glass articles that meet a minimum required surface stress (CS). The salt bath may be replaced and/or regenerated when the surface stress (CS) of the glass articles produced using the initial first and/or second molten salt baths does not meet the minimum desired surface stress (CS). For example, when the glass article has a minimum surface stress (CS) of about 950MPa, the first ion exchange step 202 and the second ion exchange step 204 may be adapted to provide a surface stress (CS) of greater than about 1000MPa to the starting glass article, and further adapted such that the rate of reduction of the surface stress (CS) obtained in each glass article per cycle allows for the processing of a predetermined number of glass articles before the first and/or second molten salt bath needs to be regenerated or replaced.

The rate of reduction of the surface stress (CS) for the ion exchange process of a given glass article can be determined experimentally or theoretically. For example, bath life studies may be conducted on a given glass article to determine parameters such as initial surface stress (CS), glass loading, and/or the number of cycles that may be run before a molten salt bath needs to be regenerated or replaced. Fig. 4A-4B illustrate results of an exemplary bath life study, according to aspects of the present disclosure. The bath life studies shown in fig. 4A-4B were performed on exemplary lithium-based glass samples treated according to the ion exchange process of method 200 of fig. 3, but at different glass loadings. In a first ion exchange step 202, glass samples were treated in a first molten salt bath comprising 80 wt% potassium and 20 wt% sodium at 390 ℃ for 6 hours. The glass samples were then treated in a second ion exchange step 204 in a second molten salt bath comprising 100 wt% potassium at 390 ℃ for 0.5 hours. Fig. 4A and 4B show the surface stress (CS) and depth of layer (DOL) according to the number of cycles (i.e., number of glass samples processed) after processing in the second ion exchange step 204_k). FIG. 4A shows 0.0065m per kg potassium salt in the second molten salt bath²Results of glass sample loading. FIG. 4B shows 0.0228m per kg potassium salt in the second molten salt bath²Results of glass sample loading. The slope of the least squares regression fit of the surface stress (CS) can be used to estimate the number of cycles the second molten bath can be used to form a glass article having the desired surface stress (CS) before regeneration or bath replacement is required, i.e., processed in the second molten bathThe number of cycles of the second molten bath may be used before the surface stress (CS) of the glass article does not meet the desired surface stress (CS).

Referring to FIG. 4A, the slope of the least squares regression fit of the surface stress (CS) is about-1.0216 MPa/cycle. Thus, for ion exchange processes in which it is desired to form glass articles having a surface stress (CS) greater than 950MPa, bath life studies can be used to estimate the number of cycles that the second molten bath can be used before it needs to be regenerated or replaced. In the example of fig. 4A, the surface stress (CS) of the initial glass sample treated according to method 200 is about 1155 MPa. Based on an estimate of a surface stress (CS) reduction of about-1.0216 MPa/cycle, the bath life study of fig. 4A can be used to estimate 0.0065m per kg potassium salt in the second molten salt bath before the surface stress (CS) in the glass drops below 950MPa²The second molten bath may be used for about 193 cycles.

Referring to FIG. 4B, the slope of the least squares regression fit of the surface stress (CS) is about-3.6685 MPa/cycle. Thus, for ion exchange processes in which it is desired to form glass articles having a surface stress (CS) greater than 950MPa, bath life studies can be used to estimate the number of cycles that the second molten bath can be used before it needs to be regenerated or replaced. In the example of fig. 4B, the surface stress (CS) of the initial glass sample treated according to method 200 is about 1155 MPa. Based on an estimate of a surface stress (CS) reduction of about-3.6685 MPa/cycle, the bath life study of fig. 4B can be used to estimate 0.0228m per kilogram potassium salt in the second molten salt bath before the surface stress (CS) in the glass drops below 950MPa²The second molten bath may be used for about 54 cycles.

Bath life studies, such as those discussed above with respect to fig. 4A and 4B, may be performed in a similar manner with respect to the first molten salt bath to determine the effect of other variables of the method 200 on the stress distribution of the treated glass article, non-limiting examples of which include glass load size, glass type, spike zone characteristics, tail zone characteristics, DOC, inflection zone characteristics, first and/or second molten salt bath temperatures, first and/or second molten salt bath concentrations, and so forth.

According to one aspect of the present disclosure, method 200 may include replacing or regenerating the second molten salt bath when the lithium concentration in the second molten salt bath reaches and/or exceeds a predetermined value or falls within a predetermined range. As described above, the amount of lithium present in the second molten salt bath, i.e., the amount of lithium poisoning in the second molten salt bath, affects the degree of surface stress (CS) that may form in glass articles treated in the second molten salt bath. In this manner, the amount of lithium poisoning may be correlated to surface stress (CS) that may develop in the glass article, and thus may be used as an indicator of when the second molten salt bath needs to be regenerated or replaced to continue being able to form a glass article having the desired surface stress (CS).

In some aspects, method 200 can be adapted such that the second molten salt bath can be utilized for at least about 10 cycles to form a compressive stress region in the glass having a surface stress (CS) greater than about 900MPa (compression). For example, method 200 may be adapted such that the second molten salt bath may be utilized for at least about 10 cycles, at least about 15 cycles, at least about 20 cycles, at least about 25 cycles, at least about 30 cycles, at least about 35 cycles, at least about 40 cycles, at least about 50 cycles, at least about 60 cycles, at least about 70 cycles, at least about 80 cycles, at least about 90 cycles, at least about 100 cycles, or at least about 150 cycles to form a compressive stress region in the glass having a surface stress (CS) greater than about 900MPa (compression). In some examples, method 200 may be adapted such that the second molten salt bath may be utilized from about 10 cycles to about 200 cycles, from about 10 cycles to about 150 cycles, from about 10 cycles to about 100 cycles, from about 10 cycles to about 90 cycles, from about 10 cycles to about 80 cycles, from about 10 cycles to about 70 cycles, from about 10 cycles to about 60 cycles, from about 10 cycles to about 50 cycles, from about 10 cycles to about 40 cycles, from about 10 cycles to about 30 cycles, from about 10 cycles to about 20 cycles, from about 20 cycles to about 150 cycles, from about 20 cycles to about 100 cycles, from about 20 cycles to about 90 cycles, from about 20 cycles to about 80 cycles, from about 20 cycles to about 70 cycles, from about 20 cycles to about 60 cycles, from about 20 cycles to about 50 cycles, from about 20 cycles to about 40 cycles, from about 20 cycles to about 30 cycles, About 30 cycles to about 150 cycles, about 30 cycles to about 100 cycles, about 30 cycles to about 90 cycles, about 30 cycles to about 80 cycles, about 30 cycles to about 70 cycles, about 30 cycles to about 60 cycles, about 30 cycles to about 50 cycles, about 30 cycles to about 40 cycles, about 40 cycles to about 150 cycles, about 40 cycles to about 100 cycles, about 40 cycles to about 90 cycles, about 40 cycles to about 80 cycles, about 40 cycles to about 70 cycles, about 40 cycles to about 60 cycles, about 40 cycles to about 50 cycles, about 50 cycles to about 150 cycles, about 50 cycles to about 100 cycles, about 50 cycles to about 90 cycles, about 50 cycles to about 80 cycles, about 50 cycles to about 70 cycles, about 50 cycles to about 60 cycles, about 60 cycles to about 150 cycles, About 60 cycles to about 100 cycles, about 60 cycles to about 90 cycles, about 60 cycles to about 80 cycles, about 60 cycles to about 70 cycles, about 70 cycles to about 150 cycles, about 70 cycles to about 100 cycles, about 70 cycles to about 90 cycles, about 70 cycles to about 80 cycles, about 80 cycles to about 150 cycles, about 80 cycles to about 100 cycles, about 80 cycles to about 90 cycles, about 90 cycles to about 150 cycles, about 90 cycles to about 100 cycles, or about 100 cycles to about 150 cycles. It should be understood that while the second molten bath is capable of forming a compressive stress region in the glass having a surface stress greater than about 900MPa (compressive) for "X" cycles, the second molten bath may be replaced or regenerated after a predetermined number of cycles less than X.

In one aspect, method 200 may include replacing or regenerating the second molten salt bath when the lithium concentration in the second molten salt bath is greater than about 0.125 wt%. In some aspects, method 200 may include replacing or regenerating the second molten salt bath when the lithium concentration in the second molten salt bath is greater than about 0.125 wt%, greater than about 0.25 wt%, greater than about 0.275 wt%, greater than about 0.3 wt%, greater than about 0.325 wt%, greater than about 0.35 wt%, or greater than about 0.375 wt%. In some aspects, method 200 can include when the lithium concentration in the second molten salt bath is about 0.125 wt% to about 0.5 wt%, about 0.125 wt% to about 0.475 wt%, about 0.125 wt% to about 0.45 wt%, about 0.125 wt% to about 0.425 wt%, about 0.125 wt% to about 0.4 wt%, about 0.125 wt% to about 0.375 wt%, about 0.125 wt% to about 0.35 wt%, about 0.125 wt% to about 0.325 wt%, about 0.125 wt% to about 0.3 wt%, about 0.125 wt% to about 275 wt%, about 0.125 wt% to about 0.25 wt%, about 0.125 wt% to about 0.225 wt%, about 0.125 wt% to about 0.2 wt%, about 0.2 wt% to about 0.5 wt%, about 0.2 wt% to about 0.475 wt%, about 0.2 wt% to about 0.425 wt%, about 0.0.35 wt% to about 0.375 wt%, about 0.0.125 wt%, about 0.125 wt% to about 0.35 wt%, about 0.2 wt% to about 0.2 wt%, about 0.2 wt% to about 0.5 wt%, about 0.35 wt%, about 0.375 wt%, about 0.2 wt%, about 0.35 wt%, about 0.2 wt%, about 0.35 wt%, about 0., About 0.2 wt% to about 0.225 wt%, about 0.225 wt% to about 0.5 wt%, about 0.225 wt% to about 0.475 wt%, about 0.225 wt% to about 0.45 wt%, about 0.225 wt% to about 0.425 wt%, about 0.225 wt% to about 0.4 wt%, about 0.225 wt% to about 0.375 wt%, about 0.225 wt% to about 0.35 wt%, about 0.225 wt% to about 0.325 wt%, about 0.225 wt% to about 0.3 wt%, about 0.225 wt% to about 0.275 wt%, about 0.225 wt% to about 0.25 wt%, about 0.25 wt% to about 0.5 wt%, about 0.25 wt% to about 0.475 wt%, about 0.25 wt% to about 0.45 wt%, about 0.25 wt% to about 0.425 wt%, about 0.25 wt% to about 0.275 wt%, about 0.25 wt% to about 0.25 wt%, about 0.275 wt% to about 0.25 wt%, about 0.25 wt% to about 0.275 wt%, about 0.0.25 wt%, about 0.25 wt% to about 0.375 wt%, about 0.25 wt% to about 0.25 wt%, about 0.25 wt% to about 0.275 wt%, about 0.25 wt% to about 0.25 wt%, about 0.25 wt% to about 0.25 wt%, about 0.275 wt%, about 0.25 wt%, about 0.9 wt%, about 0.25 wt% to about 0.25 wt%, about 0.25 wt% to about 0.35 wt%, about 0.275 wt%, about 0.9 wt%, about 0.25 wt%, about 0.35 wt%, about 0.9 wt%, about 0.35 wt%, about 0.25 wt%, about 0.275 wt%, about 0.25 wt%, about 0., About 0.275 wt% to about 0.4 wt%, about 0.275 wt% to about 0.375 wt%, about 0.275 wt% to about 0.35 wt%, about 0.275 wt% to about 0.325 wt%, about 0.275 wt% to about 0.3 wt%, about 0.3 wt% to about 0.5 wt%, about 0.3 wt% to about 0.475 wt%, about 0.3 wt% to about 0.45 wt%, about 0.3 wt% to about 0.425 wt%, about 0.3 wt% to about 0.4 wt%, about 0.3 wt% to about 0.375 wt%, about 0.3 wt% to about 0.35 wt%, about 0.35 wt% to about 0.5 wt%, about 0.35 wt% to about 0.475 wt%, about 0.35 wt% to about 0.45 wt%, about 0.35 wt% to about 0.425 wt%, about 0.35 wt% to about 0.35 wt%, about 0.35 wt% to about 0.375 wt%, about 0.35 wt% to about 0.35 wt%, about 0.375 wt%, about 0.35 wt% to about 0.375 wt%, about 0.35 wt% to about 0.35 wt%, about 0.35 wt% to about 0.375 wt%, about 0.35 wt% to about 0.35 wt%, about 0.375 wt%, about 0.35 wt% to about 0.375 wt%, about 0.35 wt%, about 0.475 wt%, about 0.35 wt%, about 0.375 wt%, about 0.35 wt% to about 0.35 wt%, about 0.375 wt%, about 0.35 wt%, about 0.475 wt%, about 0.35 wt%, or about 0.35 wt% to about 0.475 wt%, about 0.35 wt%, about 0.475 wt%, about 0.0.0.35 wt%, about 0.375 wt%, about 0.0.35 wt%, about 0.0.475 wt%, about 0.0.0.0.475 wt%, about 0.35 wt%, about 0.0.0.475 wt%, about 0.35 wt%, or about 0.475 wt%, about 0.0.0.475 wt%, about 0.0.475 wt%, about 0.45 wt%, about 0.0.45 wt%, about 0.0.0.475 wt%, about 0.35 wt%, about 0.475 wt%, about 0.0.0.0.0.0.45 wt%, about 0.475%, or about 0.0.0.0.45 to about 0.475%, or about 0.475%, about 0.0.0.0.0.475%, about 0.0.475%, about 0.0. It should be understood that the amount of lithium poisoning that is acceptable prior to replacing or regenerating the second molten salt bath may vary based on a number of factors, one example of which has a minimum required surface stress (CS) of the treated glass.

Any suitable method of regenerating the second molten salt bath may be used in the present disclosure. One exemplary method of regenerating the second molten salt bath may include sequestering lithium present in the bath, such as by using trisodium phosphate or other chemicals capable of sequestering lithium in the salt bath.

At step 206, the glass may optionally undergo one or more additional processing or treatment steps, non-limiting examples of which include annealing, shaping, cutting, laminating, and coating with a functional layer.

Examples of the invention

The following examples describe various features and advantages provided by the present disclosure, and are in no way intended to limit aspects of the present disclosure and the appended claims.

Example 1

Fig. 5 shows stress profile examples 1A-1D as a function of depth for exemplary glass samples processed in an ion exchange process according to aspects of the present disclosure. Examples 1A-1D were processed according to the same first and second ion exchange steps, except that the reaction time period of the second ion exchange step was different for each sample. Examples 1A-1D are all aluminosilicate glass samples having a thickness of about 1100 μm and a composition including about 64 mol% SiO2, 16 mol% Al₂O₃、11mol％Na₂O、6.25mol％Li₂O、1mol％TiO₂、0.04mol％SnO₂And 2.5 mol% P₂O₅. Examples 1A-1D were all treated in a first ion exchange step comprising treating in a first molten salt bath containing 80 wt% potassium and 20 wt% sodium at a temperature of about 390 ℃ for a reaction time period of about 6 hours. All samples were then processed in a second ion exchange step, which included a treatment at aboutTreating in a second molten salt bath containing 100 wt% potassium at a temperature of 390 ℃ for the following reaction time periods: 30 minutes (example 1A); 60 minutes (example 1B); 2 hours (example 1C); 4 hours (example 1D). The details of the stress profile for each example are listed in table 1 below. As described above, the surface stress (CS) is extrapolated to the Orihara FSM-6000LE measurement due to the uncertainty of the stress distribution measurement in the first approximately 2 μm obtained using the refracted near field method.

Table 1: stress distribution characteristics of examples 1A-1D

Sample (I)	Cs(MPa)	CSk(MPa)	DOLk(μm)	CT(MPa)	DOC(μm)
						Example 1A	1155	110	17.6	63	192
Example 1B	1130	100	18.2	63	187
						Example 1C	1095	65	20.4	60	187
Example 1D	1066	40	24.5	53	160

As shown in fig. 5 and the data in table 1, all examples 1A-1D exhibited stress profiles that included compressive stress regions with surface stresses (CS) greater than about 1000MPa (compression). Examples 1A-1D demonstrate that as the duration of the reaction period of the second ion exchange step increases, the inflection region (CS) can be reduced_k) Of the stress of (c). Examples 1A-1D also illustrate that as the duration of the reaction period of the second ion exchange step increases, the depth of layer (DOL)_k) It may increase, i.e., the thickness of the peak-to-peak region increases. Without wishing to be bound by any theory, it is believed that as the ion balance from the first ion exchange step is altered by the second ion exchange step, the surface stress (CS) and the inflection region (CS)_k) The stress at (a) is reduced. In certain applications, such as automotive applications, high surface stresses may be required. Thus, in applications requiring a maximum high surface stress (CS), examples 1A-1D suggest that the duration of the second ion exchange should be kept short, e.g., 0.5 hours in this example. Examples 1A-1D demonstrate the ability of the methods of the present disclosure to form compressive stress regions that include high surface stresses (e.g., greater than 1000MPa) that may be desirable in some applications.

Fig. 6A and 6B show images obtained by a FSM-6000LE surface stress meter operating at a wavelength of 589nm for example 1A. Fig. 6A is an image of the sample after the first ion exchange step and fig. 6B is an image of the sample after the second ion exchange step. FIG. 6A shows several distinct fringes, with a surface stress (CS) of 664MPa and depth of layer (DOL) after the first ion exchange step_k) 20.0 μm. Since the glass is a lithium-based glass, only a portion diffused with potassium can be seen in the image, and thus only the peak region up to the inflection point region can be measured. As shown in FIG. 6B, the second ion exchange step added a surface stress (CS) corresponding to 1155MPa and a spike region thickness (i.e., depth of layer (DOL)) of 17.6 μm_k) Additional groups of stripes.

Table 2 below shows the energy parameters for the tensile and compressive regions calculated as described above for examples 1A-1D. The poisson's ratio v and young's modulus of the glasses of examples 1A-1D are about 0.21 and 76.7GPa, respectively.

Table 2: energy parameters of the tensile and compressive regions of examples 1A-1D

The data for examples 1A-1D show that the elastic energy of the sample in the tensile stress region from the depth of compression (DOC) to the center of the glass body(per unit area of glass) (determined according to formula (IV) above) less than 20J/m²This may be an indication of a non-brittle trait. The glasses of examples 1A-1D also exhibited less than about 60MPa²m^0.5Normalized tensile energy per thickness ofThis may indicate the maximum energy allowed before the glass begins to exhibit brittle characteristics.

Example 2

FIG. 7 shows stress distribution as a function of depth for an exemplary glass sampleExamples 2A-2E, the glass samples were processed in an ion exchange process according to aspects of the present disclosure. Examples 2A-2E ("example 2A" - "example 2E") were treated according to the same first and second ion exchange steps, except that the second ion exchange step included treatment with a molten salt bath having a different amount of lithium present. As described above, as the second molten salt bath is used in a plurality of ion exchange cycles, the amount of lithium poisoning in the second molten salt bath increases with time. The different amounts of lithium present in the second molten salt bath of examples 2A-2E may simulate lithium poisoning that may occur over time as the second molten salt bath is used for multiple cycles. Examples 2A-2E are all aluminosilicate glass samples having a thickness of about 1100 μm and a composition comprising about 64 mol% SiO₂、16mol％Al₂O₃、11mol％Na₂O、6.25mol％Li₂O、1mol％TiO₂、0.04mol％SnO₂And 2.5 mol% P₂O₅. Examples 2A-2E were all treated in a first ion exchange step comprising treatment in a first molten salt bath containing 80 wt% potassium and 20 wt% sodium at a temperature of about 390 ℃ for a reaction time period of about 6 hours. All samples were then treated in a second ion exchange step comprising treatment in a second molten salt bath having a potassium concentration in wt% given by the formula (100-x), where x is the amount of lithium present, and where x is 0 wt% for example 2A; example 2B is 0.125 wt%; example 2C is 0.25 wt%; example 2D is 0.375 wt%; and 0.5 wt% for example 2E. For all samples (examples 2A-2E), the temperature of the second molten salt bath in the second ion exchange step was about 390 ℃, and the reaction time period for the second ion exchange step was 0.50 hours. The details of the stress profile for each example are listed in table 3 below. As described above, the surface stress (CS) is extrapolated to the Orihara FSM-6000LE measurement due to the uncertainty of the stress distribution measurement in the first approximately 2 μm obtained using the refracted near field method.

Table 3: stress distribution characteristics of examples 2A-2E

The results of examples 2A-2E show that as the lithium concentration in the second molten salt bath increases, the surface stress (CS) and the stress in the inflection region (CS)_k) And decreases. In contrast, depth of layer (DOL)_k) And depth of compression (DOC) remain fairly constant. In applications requiring minimal surface stress (CS), the results of examples 2A-2E indicate that the amount of lithium poisoning in the molten salt bath can be directly related to the surface stress (CS) available in the treated glass. This information can be used to configure the parameters of the ion exchange process to obtain an ion exchanged glass having the desired characteristics. For example, in the exemplary case where a surface stress greater than 950MPa is desired, the results of examples 2A-2E suggest that the second molten salt bath may produce an ion-exchanged glass having a surface stress (CS) greater than 950MPa while maintaining a lithium concentration in the second molten salt bath below about 0.25 wt%. The results of examples 2A-2E indicate that above 0.25 wt%, the surface stress (CS) of the ion-exchanged glass treated in the second molten salt bath is less than about 950MPa, and thus the second molten salt bath may need to be replaced or regenerated to continue producing glass having the desired surface stress (CS).

Table 4 below shows the results of the modeled Head Impact Test (HIT) for examples 2A-2E. The HIT system 300 is schematically illustrated in fig. 8. The HIT system 300 is designed to represent a biaxial bending situation during head impact, which typically has a 35% or higher deceleration than the related U.S. HIT regulation FMVSS 201. The HIT system 300 is designed for a 3 millisecond deceleration of 110G with a maximum deceleration of 125G, while the related regulations require a 3 millisecond deceleration of 80G. Thus, samples tested by the HIT system 300 can reasonably be expected to pass the relevant.

The HIT system 300 includes a glass sample 302 having a thickness of about 1100 μm and sample dimensions of about 91mm by about 152mm (about 3.6 inches by about 6 inches). The glass sample 302 was finished using a 400 grit edge polish followed by an 800 grit edge polish using a rounded edge. The glass sample 302 was mounted with double-sided adhesive tape 304 to a polymer plate 306 supported on two pieces of foam 308. The entire device is connected to a metal frame 31 having sufficient rigidity0 is coupled so that the deformation of the metal frame 310 can be neglected in the test. The double-sided adhesive tape 304 is a 3M tape of 101.6mm by 152.4mm^TM VHB^TMA strip of thickness 0.127mm (3M)^TMProduct number F9496 PC). Polymer plate 306 is 149.2mm 193.6mm whiteAcetal resin, 3.175mm thick (available from McMaster Carr). The foam pieces 308 are each 149.2mm x 193.6mmA hard foam of polystyrene (XPS) was extruded at 250 a thickness of 25.4mm (available from Owens Corning). The impact head 320 is about 165mm in diameter and weighs about 6.8 kg. During testing, the impact head 320 was directed to impact the glass sample 302 at a speed of 6.67m/s at a 90 degree orientation (as indicated by arrow 322). The impact head 320 is configured to simulate a human head. The results for 20 samples of each of examples 2A-2E are shown in table 4 below. Fig. 9 illustrates typical deceleration and intrusion response curves obtained by the HIT system 300 for exemplary eyewear.

Table 4: HIT results for examples 2A-2E

The HIT results in table 4 show that surface failure begins to occur between lithium poisoning levels of about 0.25 wt% Li to about 0.375 wt% Li, which corresponds to glasses having a surface stress (CS) of about 957MPa to about 926 MPa. In this test, edge damage due to poor edge finishing of the glass sample was not counted as surface damage.

The present disclosure includes the following non-limiting aspects. To the extent not already described, any of the features of the first through twenty-seventh aspects may be combined, in part or in whole, with features of any one or more of the other aspects of the disclosure to form further aspects, even if such combinations are not explicitly described.

According to aspect 1 of the present disclosure, a glass article includes a glass body having opposing first and second major surfaces and a thickness defined therebetween, wherein the glass body includes a compressive stress region comprising: a surface stress (compression) greater than about 900MPa, a spike region having a first slope, and a tail region having a second slope, and wherein the spike region and the tail region intersect at a knee region having a stress (compression) greater than about 35MPa, wherein the stress at the knee region is defined as the point at which asymptotic extrapolation of the spike region and the tail region intersect, and wherein the first slope of the spike region is steeper than about-30 MPa/μm.

According to aspect 2 of the present disclosure, the glass article of aspect 1, wherein the compressive stress region has a depth of compression greater than about 0.16 x (Th), at which the stress within the glass body is 0, wherein Th is the thickness of the glass body.

According to aspect 3 of the present disclosure, the glass article of aspect 2, wherein a slope of the tail region from the inflection region to a compression depth is greater than about 241/(Th) MPa/μ ι η, where Th is a thickness of the glass body in μ ι η.

The glass article of any of aspects 1-3, aspect 4 of the present disclosure, wherein the depth of layer of the spike region is greater than about 10 μ ι η.

The glass article of any of aspects 1-4, aspect 5 of the present disclosure, wherein the compressive stress region has a surface stress (compression) greater than about 950 MPa.

According to aspect 6 of the present disclosure, the glass article of any one of aspects 1-5, wherein the glass body is non-frangible and comprises a glass body Center Tension (CT) according to formula (I):

CT<(E/68GPa)*75MPa*1mm^0.5/(Th)^0.5 (I)

where E is the Young's modulus of the glass body, measured in GPa, and Th is the thickness of the glass body, measured in millimeters.

According to the bookAspect 7 of the disclosure, the glass article of any of aspects 1-6, wherein the glass body is non-frangible and has less than about 20J/m²Tensile energy of

The glass article of any of aspects 1-8, aspect 8, and aspect 8 of the present disclosure, wherein the glass body is non-frangible and has less than about 60MPa²m^0.5Normalized tensile energy per thickness of

According to aspect 9 of the present disclosure, the glass article of any one of aspects 1-5, wherein the glass body is frangible and comprises a glass body Center Tension (CT) according to formula (I):

CT>(E/68GPa)*75MPa*1mm^0.5/(Th)^0.5 (I)

where E is the Young's modulus of the glass body, measured in GPa, and Th is the thickness of the glass body, measured in millimeters.

The glass article of any of aspects 1-5 or 9, according to aspect 10 of the present disclosure, wherein the glass body is frangible and comprises greater than about 20J/m²Tensile energy of

The glass article of any of aspects 1-5 or 9-10, according to aspect 11 of the present disclosure, wherein the glass body is frangible and comprises greater than about 60MPa²m^0.5Normalized tensile energy per thickness of

The glass article of any of aspects 1-11, aspect 12 of the present disclosure, wherein the glass body has a thickness of about 0.2mm to about 1.3 mm.

According to aspect 13 of the present disclosure, a method of forming a plurality of glass articles comprises: a first ion exchange step comprising immersing a glass article in a first molten salt bath comprising a potassium salt and a sodium salt for a first predetermined period of time, wherein the glass article comprises a glass body having opposing first and second major surfaces and a thickness defined therebetween, and a second ion exchange step subsequent to the first ion exchange step comprising immersing the glass article in a second molten salt bath comprising a potassium salt for a second predetermined period of time to form a compressive stress region having a surface stress (compression) greater than about 900 MPa; and repeating the first ion exchange step and the second ion exchange step for one or more additional glass articles, wherein 0.0228m per kilogram of potassium salt in the second molten salt bath²The surface area glass article loading, the increase in surface stress of each glass article during the second ion exchange process, decreases by less than about 6MPa in each cycle of the first and second ion exchange steps.

According to aspect 14 of the present disclosure, the method of aspect 13, wherein 0.0065m per kg potassium salt in the second molten salt bath²A surface area glass article loading, a surface stress increase per cycle decrease of less than about 2MPa for each glass article in the second ion exchange step.

According to aspect 15 of the present disclosure, the method of aspect 13 or aspect 14, wherein the initial concentration of the potassium salt in the second molten salt bath is 100% (by weight).

According to aspect 16 of the present disclosure, the method of any one of aspects 13-15, wherein the compressive stress region of the first glass treated in the second ion exchange step has a surface stress greater than about 1000 MPa.

According to aspect 17 of the present disclosure, the method of any one of aspects 13-16, wherein the first molten salt bath comprises about 80% potassium and 20% sodium (by weight).

According to aspect 18 of the present disclosure, the method of any one of aspects 13-17, wherein the plurality of glass articles comprises lithium-based glass, the method further comprising replacing or regenerating the second molten salt bath when the lithium concentration in the second molten salt bath is from about 0.125% to about 0.25% (by weight).

According to aspect 19 of the present disclosure, the method of any one of aspects 13-18, wherein the second predetermined period of time is about 0.5 hours to about 4 hours.

According to aspect 20 of the present disclosure, the method of any one of aspects 13-19, wherein the first predetermined period of time is about 6 hours.

According to aspect 21 of the present disclosure, the method of any one of aspects 13-20, wherein the compressive stress region further comprises: a spike region having a first slope; and a tail region having a second slope, and wherein the spike region and the tail region intersect at a knee region having a stress (compression) greater than about 35MPa, wherein the stress at the knee region is defined as the point at which an asymptotic extrapolation of the spike region and the tail region intersect, and wherein the first slope of the spike region is steeper than about-30 MPa/μm.

According to aspect 22 of the present disclosure, the method of aspect 21, wherein the compressive stress region has a depth of compression greater than about 0.16 x (Th) at which the stress within the glass body is 0, wherein Th is the thickness of the glass body.

According to aspect 23 of the present disclosure, the method of aspect 21 or aspect 22, wherein a slope of the tail region from the inflection region to the compression depth is greater than about 241/(Th) MPa/μ ι η, where Th is a thickness of the glass body in μ ι η.

According to aspect 24 of the present disclosure, the method according to any one of aspects 21-23, wherein the depth of layer of the spike region is greater than about 10 μm.

According to aspect 25 of the present disclosure, the method of any of aspects 13-24, wherein the glass body is non-frangible and comprises one of: tension (CT) at center of glass body according to formula (I):

CT<(E/68GPa)*75MPa*1mm^0.5/(Th)^0.5 (I)

wherein E is the Young's modulus of the glass body, measured in GPa, and Th is the thickness of the glass body, measured in millimeters; less than about 20J/m²Tensile energy ofLess than about 60MPa²m^0.5Normalized tensile energy per thickness ofOr a combination thereof.

According to aspect 26 of the present disclosure, the method of any of aspects 13-24, wherein the glass body is frangible and comprises one of: tension (CT) at center of glass body according to formula (I):

CT>(E/68GPa)*75MPa*1mm^0.5/(Th)^0.5 (I)

wherein E is the Young's modulus of the glass body, measured in GPa, and Th is the thickness of the glass body, measured in millimeters; greater than about 20J/m²Tensile energy ofGreater than about 60MPa²m^0.5Normalized tensile energy per thickness ofOr a combination thereof.

According to aspect 27 of the present disclosure, the method of any one of aspects 13-26, wherein the glass body has a thickness of about 0.2mm to about 1.3 mm.

Many variations and modifications may be made to the above-described embodiments of the disclosure without departing substantially from the spirit and various principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

To the extent not already described, the different features of the various aspects of the present disclosure may be used in combination with each other as desired. Particular features not explicitly shown or described with respect to each aspect of the disclosure are not meant to be construed as such, but are done for brevity and conciseness of description. Thus, various features of the different aspects may be mixed and matched as desired to form new aspects, whether or not the new aspects are explicitly disclosed.