Cross-Reference to Related Applications

[0001] This application claims the benefit of priority under 35 U. S.C. § 119 of U. S. Provisional Application No. 63/347,128 filed on May 31, 2022, the content of which is incorporated herein by reference in its entirety.

Field

[0002] The present specification generally relates to methods of ion exchange, and in particular methods of ion exchanging copper containing glass articles.

Technical Background

[0003] Aluminosilicate glass articles may exhibit superior ion-exchangeability and drop performance. Various industries, including the consumer electronics industry, desire colored materials with the same or similar strength and fracture toughness properties. One such colorant is copper. However, existing ion exchange techniques are not necessarily compatible with copper containing glass articles.

[0004] Accordingly, a need exists for an alternative ion exchange process for chemically strengthening copper containing glass articles.

SUMMARY

[0005] According to an aspect, a method is provided. The method includes adding silicic acid to a molten salt bath to form a treated molten salt bath, wherein the molten salt bath comprises Na ₃ PO ₄ , LiNO ₃ , and at least one of KN0 ₃ and NaNO ₃ ; and contacting the treated molten salt bath with a glass-based substrate to form a glass-based article, wherein the glass-based substrate comprises copper and the glass-based article comprises a compressive stress region extending from a surface of the glass-based article to a depth of compression.

[0006] According to another aspect, a glass-based substrate is provided. The glass-based substrate includes greater than or equal to 40 mol% and less than or equal to 70 mol% SiO ₂ ; greater than or equal to 4 mol% and less than or equal to 20 mol% A1 ₂ O ₃ ; greater than or equal to 1 mol% and less than or equal to 10 mol% B ₂ O ₃ ; greater than or equal to 5 mol% and less than or equal to 30 mol% Li ₂ O; greater than or equal to 0.5 mol% and less than or equal to 10 mol% Na ₂ 0; and greater than or equal to 0.01 mol% and less than or equal to 2 mol% CuO.

[0007] Additional features and advantages of the glass-based articles described herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings.

[0008] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principlesand operations of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a plan view of an electronic device incorporating any of the glass-based articles accordingto one or more embodiments described herein;

[0010] FIG. 2 is a perspective view of the electronic device of FIG. 1 ;

[0011] FIG. 3 is a photograph of an edge lit comparative example after ion exchange treatment;

[0012] FIG. 4 is a photograph of a glass article produced by a method according to an embodiment;

[0013] FIG. 5 is an optical microscopy image of the comparative example of FIG. 3;

[0014] FIG. 6 is an optical microscopy image of the example of FIG. 4;

[0015] FIG. 7 is a SIMS analysis of the comparative example of FIG. 3;

[0016] FIG. 8 is a SIMS analysis of the example of FIG. 4; and [0017] FIG. 9 is a plot of a* (x-axis) versus b* (y-axis) of comparative and example glassbased substrates, according to one or more embodiments described herein.

DETAILED DESCRIPTION

[0018] Reference will now be made in detail to various embodiments of methods of ion exchanging copper containing glass-based substrates to form glass-based articles having relatively high lightness (“L*”) values.

[0019] In embodiments, the method includes adding silicic acid to a molten salt bath to form a treated molten salt bath, wherein the molten salt bath comprises Na ₃ PO ₄ , LiNO ₃ , and at least one of KN0 ₃ and NaNO ₃ ; and contacting the treated molten salt bath with a glass-based substrate to form a glass-based article, wherein the glass-based substrate comprises copper and the glass-based article comprises a compressive stress region extending from a surface of the glass-based article to a depth of compression.

[0020] In other embodiments, a glass-based substrate includes greater than or equal to 40 mol% and less than or equal to 70 mol% SiO ₂ ; greater than or equal to 4 mol% and less than or equal to 20 mol% A1 ₂ O ₃ ; greater than or equal to 1 mol% and less than or equal to 10 mol% B ₂ O ₃ ; greater than or equal to 5 mol% and less than or equal to 30 mol% Li ₂ O; greater than or equal to 0.5 mol% and less than or equal to 10 mol% Na ₂ O; and greater than or equal to 0.01 mol% and less than or equal to 2 mol% CuO.

[0021] Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use ofthe antecedent“about,” itwill be understood that the particular value forms another embodiment. 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.

[0022] Directional terms as used herein - for example up, down, right, left, front, back, top, bottom - are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0023] Unless otherwise expressly stated, 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, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim doesnot actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.

[0024] As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise.

[0025] In the embodiments of the glass compositions and the resultant glass-based substrates described herein, the concentrations of constituent components in oxide form (e.g., SiO ₂ , A1 ₂ O ₃ , and the like) are specified in mole percent (mol%) on an oxide basis, unless otherwise specified. While the amounts of the constituent components are described herein with respect to the glass-based substrate, one skilled in the art would appreciate that the amounts provided herein may be with respect to the glass composition used to form the glass-based substrate and the glass-based article formed from the glass-based substrate.

[0026] The term “substantially free,” when used to describe the concentration and/or absence of a particular constituent component in a glass composition and the resultant glass-based substrate, means that the constituent component is not intentionally added to the glass composition and the resultant glass-based substrate. However, the glass composition and the glass-based substrate may contain traces of the constituent component as a contaminant or tramp, such as in amounts of less than 0.01 mol%, unless specified otherwise herein.

[0027] The terms “0 mol%” and “free,” when used to describe the concentration and/or absence of a particular constituent component in a glass composition and the resultant glassbased substrate, means that the constituent component is not present in the glass composition and the resultant glass-based substrate. [0028] Surface compressive stress is measured with a surface stress meter (FSM) such as commercially available instruments such as the FSM-6000, manufactured by Orihara Industrial Co., Ltd. (Japan). Surface stress measurements rely upon the measurement of the stress optical coefficient (SOC), which is related to the birefringence of the glass article. SOC, in turn, is measured according to Procedure C (Glass Disc Method) described in ASTM standard C770-16, entitled “Standard TestMethod for Measurement of Glass Stress-Optical Coefficient,” the contents of which are incorporated herein by reference in their entirety. Depth of compression (DOC) is also measured with the FSM. The maximum central tension (CT) values are measured using a scattered light polariscope (SCALP) technique known in the art.

[0029] The term “depth of compression” (DOC), as used herein, refers to the position in the article where compressive stress transitions to tensile stress.

[0030] The term “CIELAB color space,” as used herein, refers to a color space defined by the International Commission on Illumination (CIE) in 1976. It expresses color as three values: L* for the lightness from black (0) to white (100), a* from green (-) to red (+), and B* from blue (-) to yellow (+).

[0031] The term “glass-based substrate,” as used herein, refers to the material formed when a glass composition is heat treated at one or more preselected temperatures for one or more preselected times to melt the glass composition and cool the glass composition.

[0032] The term “glass-based article,” as used herein, refers to the material formed when the glass-based substrate is ion exchanged as described herein.

[0033] In the context of this application, the term “glass-based” refers to an article or substrate made wholly or partially from glass, and includes glass-ceramic and glass laminate materials. For the sake of convenience, glass-based articles and glass-based substrates may be referred to herein as glass articles and glass substrates, respectively.

[0034] Copper has been included in alkali aluminosilicate glass articles as a colorant, to provide a desired color to the glass. Such glasses are ion exchanged to provide additional strength and damage resistance, and may be employed in housings for electronic devices. It has been discovered that when the copper containing glass-based substrates are ion exchanged in molten salt baths that have been regenerated with trisodium phosphate (TSP or Na ₃ PO4), particle defects are produced on the surface of the resulting glass articles, producing an undesirable hazy appearance. The particle defects may be removed by physical or chemical polishing, but such an approach adds complexity and cost to the ion exchange process and may result in the removal of a portion of the compressive stress layer produced by the ion exchange. Described herein is a method for ion exchanging copper containing glass-based substrates in molten salt baths that have been regenerated with TSP that avoids the formation of particle defects on the surface of the resulting glass article. Additionally, due to the presence of copper, the glass-based substrates and resultingglass-based articles have relatively high lightness (“L*”) values.

[0035] In typical ion-exchange processes, smaller metal ions in the glass compositions are replaced or “exchanged” with larger metal ions of the same valence within a layer that is close to the outer surface of the glass-based substrate. The replacement of smaller ions with larger ions creates a compressive stress within the layer of the glass article. In embodiments, the metal ions are monovalent metal ions (e.g., Li ⁺ , Na ⁺ , K ⁺ , and the like), and ion-exchange is accomplished by immersing the glass-based substrate in a bath comprising at least one molten salt of the larger metal ion that is to replace the smaller metal ion in the glass-based substrate. Alternatively, other monovalent ions such as Ag ⁺ , Tl ⁺ , and the like may be exchanged for monovalent ions. The ion-exchange process or processes that are used to strengthen the glassbased substrate may include contacting the glass-based substrate with an ion-exchange medium. In embodiments, the ion-exchange medium maybe a molten salt bath. For example, the ion-exchange process may include, but is not limited to, immersion in a single bath or multiple baths of like or different compositions with optional washing and/or annealing steps between immersions.

[0036] The ion-exchange process also changes the composition of the ion-exchange medium. For example, if Li ⁺ ions are exchanged out of the glass for Na ⁺ and/or K ⁺ ions from the bath, the bath becomes enriched in Li ⁺ ions and depleted in Na ⁺ and/or K ⁺ ions. This change in bath composition may prevent the achievement of the desired stress profile in the glass articles when the bath is reused. To address this issue, the bath may be regenerated to return the bath to the desired composition. An approach to regenerating the bath is to add TSP to the bath, which provides additional Na ⁺ ions to the bath while the phosphate reacts with and removes free Li ⁺ ions from the bath. This regeneration process allows the ion exchange bath to be utilized for more production runs while maintaining the desired stress profile. [0037] The inventors have discovered that when a copper containing glass-based substrate is ion exchanged in a molten salt bath that has been regenerated with TSP, particle defects are formed at the surface of the glass article. These particle defects cannot be removed by ultrasonication washing processes that utilize an alkaline detergent. The surface particle defects mean that to ion exchange a copper containing glass-based substrate, either a fresh bath (not regenerated with TSP) must be employed, or the particle defects must be removed by chemical or physical polishing, all of which increase the cost and complexity of the ion exchange process significantly. The inventors have discovered a method to ion exchange copper containing glass-based substrate in a molten salt bath that has been regenerated with TSP while avoiding the formation of particle defects on the surface. The method saves cost and time by addressing the particle defect formation in the ion exchange process as opposed to by post-strengthening treatments, and is especially suitable for forming glass articles that are difficult to polish, such as those with curved features or holes.

[0038] The ion exchange method includes adding silicic acid to the TSP regenerated molten salt bath after the addition of the TSP but prior to the ion exchange of the copper containing glass-based substrates. In embodiments, silicic acid is added to a molten salt bath to form a treated molten salt bath, and contacting the treated molten salt bath with a glass-based substrate to form a glass-based article. The molten salt bath may include Na ₃ PO4, LiNO ₃ , and at least one of KN0 ₃ andNaNO ₃ , and the glass-based substrate includes copper. The produced glass-based article includes a compressive stress region extending from a surface of the glassbased article to a depth of compression.

[0039] Without wishing to be bound by any particular theory, the silicic acid may prevent the formation of particle defects on the surface of the resulting glass articles by interacting with the TSP. A first mechanism is that free phosphate ions from the TSP added to the bath may hydrolyze and form hydroxy ions, which may then etch the surface of the glass and leach copper out of the glass. The addition of silicic acid may neutralize these hydroxy ions and prevent the etching of the glass surface. A second mechanism is that a small amount of TSP particles may be suspended in the molten salt bath, which may attach to the surface of the glass. The addition of silicic acid may help to precipitate the TSP particles to the bottom of the molten salt bath, preventing contact of the TSP particles with the glass surface. These mechanisms may operate in conjunction or separately, and there may be other mechanisms by which the addition of silicic acid prevents the formation of particle defects on the glass surface. [0040] The silicic acid may be added to the TSP containing molten saltbath in any appropriate amount. In embodiments, the silicic acid is added in an amount greater than or equal to 0.5 wt% to less than or equal to 10 wt% based on the total weight of the molten salt bath, such as greater than or equal to 1 wt% to less than or equal to 9 wt%, greater than or equal to 2 wt% to less than or equal to 8 wt%, greater than or equal to 3 wt% to less than or equal to 7 wt%, greater than or equal to 4 wt% to less than or equal to 6 wt%, greater than or equal to 0.5 wt% to less than or equal to 5 wt%, and any and all sub-ranges formed from the foregoing endpoints. In a preferred embodiment, the silicic acid is added in an amount of about 1 wt% based on the total weight of the molten salt bath. The silicic acid must be added to the molten salt bath afterthe addition of the TSP butpriorto contactingthe copper containing glass-based substrate with the molten salt bath to achieve the desired avoidance of particle defects on the surface of the copper containing glass article.

[0041] The molten salt bath includesLiNO ₃ and atleast one of NaNO ₃ and KN0 ₃ . The LiNO ₃ in the bath may be added to achieve the desired stress profile characteristics, or may be the result of previous use of the molten salt bath to ion exchange glass-based substrates. The NaNO ₃ and KN0 ₃ are present in the bath to provide strengthening ions to the glass-based substrates duringion exchange treatments. In embodiments, the bath may include both NaNO ₃ and KN0 ₃ to provide a multiple ion strengthening approach, where the potassium produces a high compressive stress “spike” at the surface of the glass article and the sodium produces a deep depth of compressive stress in the glass article.

[0042] The molten salt bath to which the silicic acid is added may contain any appropriate amount of LiNO ₃ . In embodiments, the molten salt bath includes LiNO ₃ in an amount greater than or equal to 0.5 wt% to less than or equal to 2 wt% based on the total weight of the molten salt bath, such as greater than or equal to 0.5 wt% to less than or equal to 1.5 wt%, greater than or equal to 0.5 wt% to less than or equal to 1 wt%, and any and all sub-ranges formed between the foregoing endpoints.

[0043] The molten salt bath may be formed by adding TSP to a salt bath that contains LiNO ₃ and atleast one of NaNO ₃ and KN0 ₃ , which maybe referred to as regenerating the saltbath. The TSP may be added to the bath in any appropriate amount. In embodiments, the TSP is added to the salt bath in an amount sufficient to return the LiNO ₃ concentration in the bath to the desired level, such as the LiNO ₃ concentration in a fresh molten salt bath prior to use in an ion exchange process. In embodiments, the TSP may be added to a molten salt bath with a LiNO ₃ concentration greater than or equal to 1.5 wt% to less than or equal to 10 wt% based on the total weight of the bath, such as greater than or equal to 2 wt% to less than or equal to 9 wt%, greater than or equal to 3 wt% to less than or equal to 8 wt%, greater than or equal to 4 wt% to less than or equal to 7 wt%, greater than or equal to 5 wt% to less than or equal to 6 wt%, and any and all sub-ranges formed from the foregoing endpoints.

[0044] After the addition of the silicic acid, the molten salt bath may be aged prior to contactingtheion exchange bath with the glass-based substrates. The aging allows the desired effect of the addition of the silicic acid to be fully achieved. In embodiments, the molten salt bath is aged for a time period of greater than or equal to 10 minutes to less than or equal to 4 hours after the addition of the silicic acid, such as greater than or equal to 20 minutes to less than or equal to 3.5 hours, greater than or equal to 30 minutes to less than or equal to 3 hours, greater than or equal to 1 hour to less than or equal to 2 hours, and any and all sub -ranges formed from the foregoing endpoints. The bath may also be aged for a time sufficientto return the bath to the desired bath temperature after the addition of the silicic acid.

[0045] The molten salt bath may also include silicic acid prior to the addition of silicic acid described herein. Silicic acid is added to molten salt baths for a variety of reasons. In embodiments, the molten salt bath may include any appropriate amount of silicic acid prior to the addition of silicic acid in the methods described herein. For example, the molten salt bath may include greater than or equal to 0.5 wt% to less than or equal to 10 wt% silicic acid based on the total weight of the molten salt bath prior to the addition of the silicic acid described herein, with a preferred content of silicic acid being greater than or equal to 0.5 wt% to less than or equal to 1 wt%.

[0046] Upon exposure to the glass-based substrate, the ion-exchange medium (e.g., molten salt bath) may, according to embodiments, be at a temperature greater than or equal to 350 °C and less than or equal to 500 °C, temperature greater than or equal to 350 °C and less than or equal to 480 °C, greater than or equal to 360 °C and less than or equal to 450 °C, greater than or equal to 370 °C and less than or equal to 440 °C, greater than or equal to 360 °C and less than or equal to 420 °C, greater than or equal to 370 °C and less than or equal to 400 °C, greater than or equal to 375 °C and less than or equal to 475 °C, greater than or equal to 400 °C and less than or equal to 500 °C, greater than or equal to 410 °C and less than or equal to 490 °C, greater than or equal to 420 °C and less than or equal to 480 °C, greater than or equal to 430 °C and less than or equal to 470 °C, or even greater than or equal to 440 °C and less than or equal to 460 °C, or any and all sub-ranges between the foregoing values. The silicic acid may begin to decompose at temperatures above 480 °C and as a result bath temperatures less than or equal to 480 °C may be preferred.

[0047] In embodiments, the glass-based substrate may be exposed to the ion-exchange medium for a duration greater than or equal to 2 hours and less than or equal to 24 hours, such as greater than or equal to 2 hours and less than or equal to 12 hours, greater than or equal to 2 hours and less than or equal to 6 hours, greater than or equal to 8 hours and less than or equal to 24 hours, greater than or equal to 6 hours and less than or equal to 24 hours, greater than or equal to 6 hours and less than or equal to 12 hours, greater than or equal to 8 hours and less than or equal to 24 hours, or even greater than or equal to 8 hours and less than or equal to 12 hours, or any and all sub-ranges formed from the foregoing endpoints.

[0048] The molten salt bath may include any appropriate amount of KN0 ₃ . In embodiments, the molten salt bath includes KN0 ₃ in an amount greater than or equal to 50 wt% based on the total weight of the bath, such as greater than or equal to 50 wt% to less than or equal to 100 wt%, greater than or equal to 60 wt% to less than or equal to 90 wt%, greater than or equal to 70 wt% to less than or equal to 80 wt%, and any and all sub-ranges formed from the foregoing endpoints. In embodiments, the molten salt bath may be substantially free or free of KNO ₃ .

[0049] The molten salt bath may include any appropriate amount ofNaNO ₃ . In embodiments, the molten salt bath includes NAN0 ₃ in an amount greater than or equal to 10 wt% to less than or equal to 50 wt% based on the total weight of the bath, such as greater than or equal to 15 wt% to less than or equal to 40 wt%, greater than or equal to 20 wt% to less than or equal to 30 wt%, and any and all sub-ranges formed from the foregoing endpoints. In embodiments, the molten salt bath may be substantially free or free of NaNO ₃ .

[0050] In embodiments, the glass-based substrate may be ion-exchanged to achieve a depth of compression of the glass-based article of greater than or equal to 30 pm, greater than or equal to 40 pm, greater than or equal to 50 pm, greater than or equal to 60 pm, greater than or equal to 70 pm, greater than or equal to 80 pm, greater than or equal to 90 pm, greater than or equal to 100 pm, or more. In embodiments, the glass-based substrate may have a thickness “f ’ and may be ion-exchanged to achieve a depth of compression of the glass-based article greater than or equal to 0. It, such as greater than or equal to 0.15t, greater than or equal to 0.2t, or more. In embodiments, the glass-based substrate described herein may have a thickness “t” and may be ion-exchanged to achieve a depth of compression of the glass-based article greater than or equal to 0. It and less than or equal to 0.3t, greater than or equal to 0.15t and less than or equal to 0.25t, or any and all sub-ranges formed from any of these endpoints.

[0051] The development of this surface compression layer is beneficial for achieving a better crack resistance and higher flexural strength compared to non-ion-exchanged materials. The surface compression layer has a higher concentration of the ions exchanged into the glass article in comparison to the concentration of the ions exchanged into the glass article for the body (i.e., the areanotincludingthe surface compression) ofthe glass article. In embodiments, the glass article may have a surface compressive stress after ion-exchange strengthening greater than or equal to 400 MPa, such as greater than or equal to 500 MPa, greater than or equal to 600 MPa, or more. In embodiments, the glass article may have a surface compressive stress after ion-exchange strengthening greater than or equal to 300 MPa and less than or equal to 1 .5 GPa, greater than or equal to 300 MPa and less than or equal to 1 GPa, greater than or equal to 400 MPa and less than or equal to 900 MPa, greater than or equal to 500 MPa and less than or equal to 800 MPa, greater than or equal to 600 MPa and less than or equal to 700 MPa, or any and all sub-ranges formed from the foregoing endpoints.

[0052] In embodiments, the glass articles may have a central tension after ion-exchange strengthening greater than or equal to 40 MPa, greater than or equal to 60 MPa, greater than or equal to 80 MPa, greater than or equal to 100 MPa, or more. In embodiments, the glass article may have a central tension after ion-exchange strengthening less than or equal to 250 MPa, less than or equal to 200 MPa, less than or equal to 150 MPa, or less. In embodiments, the glass article may have a central tension after ion-exchange strengthening greater than or equal to 40 MPa and less than or equal to 250 MPa, greater than or equal to 40 MPa and less than or equal to 200 MPa, greater than or equal to 40 MPa and less than or equal to 150 MPa, greater than or equal to 60 MPa and less than or equal to 250 MPa, greater than or equal to 60 MPa and less than or equal to 200 MPa, greater than or equal to 60 MPa and less than or equal to 150 MPa, greater than or equal to 80 MPa and less than or equal to 250 MPa, greater than or equal to 80 MPa and less than or equal to 200 MPa, greater than or equal to 80 MPa and less than or equal to 150 MPa, greater than or equal to 100 MPa and less than or equal to 250 MPa, greater than or equal to 100 MPa and less than or equal to 200 MPa, or even greater than or equal to lOOMPa and less than or equal to 150MPa, or any and all sub -ranges formed from any of these endpoints. As utilized herein, central tension refers to a maximum central tension value unless otherwise indicated.

[0053] In embodiments, a ratio of compressive stress to central tension of the glass article, after ion-exchange strengthening, may be from 2:1 to 10:1, from 2:1 to 8: 1, from 4: 1 to 10:1, from 4:1 to 8:1, from 6: 1 to 10:1, or even from 6:1 to 8:1, or any and all sub-ranges formed from any of these endpoints.

[0054] The glass articles described herein may be any suitable thickness, which may vary depending on the particular application of the glass article. In embodiments, the glass articles may have a thickness greater than or equal to 250 pm and less than or equal to 6 mm, greater than or equal to 250 pm and less than or equal to 4 mm, greater than or equal to 250 pm and less than or equal to 2 mm, greater than or equal to 250 pm and less than or equal to 1 mm, greater than or equal to 250 pm and less than or equal to 750 pm, greater than or equal to 250 pm and less than or equal to 500 pm, greater than or equal to 500 pm and less than or equal to 6 mm, greater than or equal to 500 pm and less than or equal to 4 mm, greater than or equal to 500 pm and less than or equal to 2 mm, greater than or equal to 500 pm and less than or equal to 1 mm, greater than or equal to 500 pm and less than or equal to 750 pm, greater than or equal to 750 pm and less than or equal to 6 mm, greater than or equal to 750 pm and less than or equal to 4 mm, greater than or equal to 750 pm andless than or equal to 2 mm, greater than or equal to 750 pm and less than or equal to 1 mm, greater than or equal to 1 mm and less than or equal to 6 mm, greater than or equal to 1 mm and less than or equal to 4 mm, greater than or equal to 1 mm and less than or equal to 2 mm, greater than or equal to 2 mm and less than or equal to 6 mm, greater than or equal to 2 mm and less than or equal to 4 mm, or even greater than or equal to 4 mm and less than or equal to 6 mm, or any and all sub-ranges formed from any of these endpoints.

[0055] The ion exchange methods described herein do notrequire postion exchange polishing treatments. In embodiments, the methods described herein do not include a physical polishing of the glass article, a chemical polishing of the glass article, or do not include chemically or physically polishing the glass article after ion exchange.

[0056] The glass-based substrates subjected to the ion exchanged treatments described herein include copper, and maybe alkali aluminosilicates. As described herein, copper, particularly CuO, is included as a colorant to provide a desired color to the glass-based substrate. In embodiments, the glass-based substratesmay include copper in a concentration of greaterthan or equal to 0.01 mol% to less than or equal to 2 mol% CuO, such as greaterthan or equal to 0.1 mol% to less than or equal to 1.5 mol% CuO, greater than or equal to 0.5 mol% to less than or equal to 1 .25 mol% CuO, greater than or equal to 0.75 mol% to less than or equal to 1 mol% CuO, and any and all sub-ranges formed from the foregoing endpoints. In embodiments, the concentration of CuO in the glass-based substrate may be greater than or equal to 0.01 mol%, greater than or equal to 0.02 mol%, or even greaterthan or equal to 0.03 mol%. In embodiments, the concentration of CuO in the glass-based substrate may be less than or equal to 2 mol%, less than or equal to 1 mol%, less than or equal to 0.5 mol%, less than or equal to 0.25 mol%, less than or equal to 0.1 mol%, or even less than or equal to 0.05 mol%. In embodiments, the concentration of CuO in the glass-based substrate may be greater than or equal to 0.01 mol% and less than or equal to 2 mol%, greater than or equal to 0.01 mol% and less than or equal to 1 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.25 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.1 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.05 mol%, greater than or equal to 0.02 mol% and less than or equal to 2 mol%, greater than or equal to 0.02 mol% and less than or equal to 1 mol%, greater than or equal to 0.02 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.02 mol% and less than or equal to 0.25 mol%, greaterthan or equal to 0.02 mol% and less than or equal to 0. 1 mol%, greater than or equal to 0.02 mol% and less than or equal to 0.05 mol%, greater than or equal to 0.03 mol% and less than or equal to 2 mol%, greater than or equal to 0.03 mol% and less than or equal to 1 mol%, greater than or equal to 0.03 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.03 mol% and less than or equal to 0.25 mol%, greaterthan or equal to 0.03 mol% and less than or equal to 0. 1 mol%, or even greater than or equal to 0.03 mol% and less than or equal to 0.05 mol%, or any and all sub-ranges formed from any of these endpoints.

[0057] SiO ₂ is the primary glass former in the glass-based substrates described herein and may function to stabilize the network structure of the glass-based substrates. The concentration of SiO ₂ in the glass-based substrates should be sufficiently high (e.g., greater than or equal to 40 mol%) to enhance the chemical durability of the glass-based substrate and, in particular, the resistance of the glass composition to degradation upon exposure to acidic solutions, basic solutions, and in water. The concentration of SiO ₂ may be limited (e.g., less than or equal to 70 mol%) to control the melting point of the glass-based substrate, as the melting point of pure SiO ₂ or high SiO ₂ glasses is undesirably high. Thus, limiting the concentration of SiO ₂ may aid in improving the meltability and the formability of the glassbased substrate. In embodiments, the glass-based substrate may comprise greater than or equal to 40 mol% and less than or equal to 70 mol% SiO ₂ . In embodiments, the concentration of SiO ₂ in the glass-based substrate may be greater than or equal to 40 mol%, greaterthan or equal to 45 mol%, greater than or equal to 50 mol%, or even greater than or equal to 55 mol%. In embodiments, the concentration of SiO ₂ in the glass-based substrate may be less than or equal to 70 mol%, less than or equal to 67 mol%, less than or equal to 65 mol%, less than or equal to 63 mol%, or even less than or equal 60 mol%. In embodiments, the concentration of SiO ₂ in the glass-based substrate may be greater than or equal to 40 mol% and less than or equal to 70 mol%, greater than or equal to 40 mol% and less than or equal to 67 mol%, greater than or equal to 40 mol% and less than or equal to 65 mol%, greater than or equal to 40 mol% and less than or equal to 63 mol%, greater than or equal to 40 mol% and less than or equal to 60 mol%, greater than or equal to 45 mol% and less than or equal to 70 mol%, greater than or equal to 45 mol% and less than or equal to 67 mol%, greater than or equal to 45 mol% and less than or equal to 65 mol%, greater than or equal to 45 mol% and less than or equal to 63 mol%, greater than or equal to 45 mol% and less than or equal to 60 mol%, greater than or equal to 50 mol% and less than or equal to 70 mol%, greater than or equal to 50 mol% and less than or equal to 67 mol%, greater than or equal to 50 mol% and less than or equal to 65 mol%, greater than or equal to 50 mol% and less than or equal to 63 mol%, greater than or equal to 50 mol% and less than or equal to 60 mol%, greater than or equal to 55 mol% and less than or equal to 70 mol%, greater than or equal to 55 mol% and less than or equal to 67 mol%, greater than or equal to 55 mol% and less than or equal to 65 mol%, greater than or equal to 55 mol% and less than or equal to 63 mol%, or even greater than or equal to 55 mol% and less than or equal to 60 mol%, or any and all sub-ranges formed from any of these endpoints.

[0058] Like SiO ₂ , A1 ₂ O ₃ may also stabilize the glass network and additionally provides improved mechanical properties and chemical durability to the glass-based substrate. The amount of A1 ₂ O ₃ may also be tailored to control the viscosity of the glass composition. However, if the amount of A1 ₂ O ₃ is too high (e.g., greaterthan 20 mol%), the viscosity of the melt may increase, thereby diminishing the formability of the glass-based substrate. Accordingly, in embodiments, the glass-based substrate may comprise greaterthan or equal to 4 mol% and less than or equal to 20 mol% A1 ₂ O ₃ . In embodiments, the concentration of A1 ₂ O ₃ in the glass-based substrate may be greater than or equal to 4 mol%, greater than or equal to 6 mol%, greater than or equal to 8 mol%, or even greater than or equal to 10 mol%. In embodiments, the concentration of A1 ₂ O ₃ in the glass-based substrate may be less than or equal to 20 mol%, less than or equal to 18 mol%, less than or equal to 16 mol%, or even less than or equal to 14 mol%. In embodiments, the concentration of A1 ₂ O ₃ in the glass-based substrate may be greater than or equal to 4 mol% and less than or equal to 20 mol%, greater than or equal to 4 mol% and less than or equal to 18 mol%, greater than or equal to 4 mol% and less than or equal to 16 mol%, greater than or equal to 4 mol% and less than or equal to 14 mol%, greater than or equal to 6 mol% and less than or equal to 20 mol%, greater than or equal to 6 mol% and less than or equal to 18 mol%, greater than or equal to 6 mol% and less than or equal to 16 mol%, greater than or equal to 6 mol% and less than or equal to 14 mol%, greater than or equal to 8 mol% and less than or equal to 20 mol%, greater than or equal to 8 mol% and less than or equal to 18 mol%, greater than or equal to 8 mol% and less than or equal to 16 mol%, greater than or equal to 8 mol% and less than or equal to 14 mol%, greater than or equal to 10 mol% and less than or equal to 20 mol%, greater than or equal to 10 mol% and less than or equal to 18 mol%, greater than or equal to 10 mol% and less than or equal to 16 mol%, or even greater than or equal to 10 mol% and less than or equal to 14 mol%, or any and all sub-ranges formed from any of those endpoints.

[0059] B ₂ O ₃ may improve the damage resistance of the glass-based substrate. In addition, B ₂ O ₃ is added to reduce the formation of non-bridging oxygen, the presence of which may reduce fracture toughness. The concentration of B ₂ O ₃ should be sufficiently high (e.g., greater than or equal to 1 mol%) to improve the formability and increase the fracture toughness of the glass-based substrate. However, if B ₂ O ₃ is too high (e.g., greater than 10 mol%), the annealing point and strain point may decrease, which increases stress relaxation and reduces the overall strength of the glass-based substrate. In embodiments, the glass-based substrate may comprise greater than or equal to 1 mol% and less than or equal to 10 mol% B ₂ O ₃ . In embodiments, the concentration of B ₂ O ₃ in the glass-based substrate may be greater than or equal to 1 mol%, greater than or equal to 2 mol%, greater than or equal to 3 mol%, or even greater than 4 mol%. In embodiments, the concentration of B ₂ O ₃ in the glass-based substrate may be less than or equal to 10 mol%, less than or equal to 8 mol%, or even less than or equal to 6 mol%. In embodiments, the concentration of B ₂ O ₃ in the glass-based substrate may be greater than or equal to 1 mol% and less than or equal to 10 mol%, greater than or equal to 1 mol% and less than or equal to 8 mol%, greater than or equal to 1 mol% and less than or equal to 6 mol%, greater than or equal to 2 mol% and less than or equal to 10 mol%, greater than or equal to 2 mol% and less than or equal to 8 mol%, greater than or equal to 2 mol% and less than or equal to 6 mol%, greater than or equal to 3 mol% and less than or equal to 10 mol%, greater than or equal to 3 mol% and less than or equal to 8 mol%, greater than or equal to 3 mol% and less than or equal to 6 mol%, greater than or equal to 4 mol% and less than or equal to 10 mol%, greater than or equal to 4 mol% and less than or equal to 8 mol%, or even greater than or equal to 4 mol% and less than or equal to 6 mol%, or any and all-subranges formed from any of these endpoints.

[0060] As described hereinabove, the glass-based substrates may contain alkali oxides, such as Li ₂ O, Na ₂ O, and K ₂ O, to enable the ion-exchangeability of the glass-based substrates.

[0061] Li ₂ O aids in the ion-exchangeability of the glass-based substrate and also reduces the softening point of the glass-based substrate, thereby increasing the formability of the glassbased substrate. The concentration of Li ₂ O in the glass-based substrate should be sufficiently high (e.g., greater than or equal to 5 mol%) to achieve a desired maximum central tension (e.g., greater than or equal to 40 MPa). However, if the amount of Li ₂ O is too high (e.g., greater than 30 mol%), the liquidus temperature may increase, thereby diminishing the manufacturability of the glass-based substrate. In embodiments, the glass-based substrate may comprise greater than or equal to 5 mol% and less than or equal to 30 mol% Li ₂ O. In embodiments, the concentration of Li ₂ O in the glass-based substrate may be greater than or equal to 5 mol%, greater than or equal to 7 mol%, greater than or equal to 10 mol%, greater than or equal to 15 mol%, greater than or equal to 17 mol%, or even greater than or equal to 20 mol%. In embodiments, the concentration of Li ₂ O in the glass-based substrate may be less than or equal to 30 mol%, less than or equal to 27 mol%, less than or equal to 25 mol%, less than or equal to 23 mol%, less than or equal to 20 mol%, less than or equal to 17 mol%, or even less than or equal to 15 mol%. In embodiments, the concentration of Li ₂ O in the glassbased substrate may be greater than or equal to 5 mol% and less than or equal to 30 mol%, greater than or equal to 5 mol% and less than or equal to 27 mol%, greater than or equal to 5 mol% and less than or equal to 25 mol%, greater than or equal to 5 mol% and less than or equal to 23 mol%, greater than or equal to 5 mol% and less than or equal to 20 mol%, greater than or equal to 5 mol% and less than or equal to 17 mol%, greater than or equal to 5 mol% and less than or equal to 15 mol%, greater than or equal to 7 mol% and less than or equal to 30 mol%, greater than or equal to 7 mol% and less than or equal to 27 mol%, greater than or equal to 7 mol% and less than or equal to 25 mol%, greater than or equal to 7 mol% and less than or equal to 23 mol%, greater than or equal to 7 mol% and less than or equal to 20 mol%, greater than or equal to 7 mol% and less than or equal to 17 mol%, greater than or equal to 7 mol% and less than or equal to 15 mol%, greater than or equal to 10 mol% and less than or equal to 30 mol%, greater than or equal to 10 mol% and less than or equal to 27 mol%, greater than or equal to 10 mol% and less than or equal to 25 mol%, greater than or equal to 10 mol% and less than or equal to 23 mol%, greater than or equal to 10 mol% and less than or equal to 20 mol%, greater than or equal to 10 mol% and less than or equal to 17 mol%, greater than or equal to 10 mol% and less than or equal to 15 mol%, greater than or equal to 13 mol% and less than or equal to 30 mol%, greater than or equal to 13 mol% and less than or equal to 27 mol%, greater than or equal to 13 mol% and less than or equal to 25 mol%, greater than or equal to 13 mol% and less than or equal to 23 mol%, greater than or equal to 13 mol% and less than or equal to 20 mol%, greater than or equal to 13 mol% and less than or equal to 17 mol%, greater than or equal to 13 mol% and less than or equal to 15 mol%, greater than or equal to 15 mol% and less than or equal to 30 mol%, greater than or equal to 15 mol% and less than or equal to 27 mol%, greater than or equal to 15 mol% and less than or equal to 25 mol%, greater than or equal to 15 mol% and less than or equal to 23 mol%, greater than or equal to 15 mol% and less than or equal to 20 mol%, greater than or equal to 15 mol% and less than or equal to 17 mol%, greater than or equal to 17 mol% and less than or equal to 30 mol%, greater than or equal to 17 mol% and less than or equal to 27 mol%, greater than or equal to 17 mol% and less than or equal to 25 mol%, greater than or equal to 17 mol% and less than or equal to 23 mol%, greater than or equal to 17 mol% and less than or equal to 20 mol%, greater than or equal to 20 mol% and less than or equal to 30 mol%, greater than or equal to 20 mol% and less than or equal to 27 mol%, greater than or equal to 20 mol% and less than or equal to 25 mol%, or even greater than or equal to 20 mol% and less than or equal to 23 mol%, or any and all sub-ranges formed from any of these endpoints.

[0062] Na ₂ O improves diffusivity of alkali ions in the glass and thereby reduces ion-exchange time and helps achieve the desired surface compressive stress (e.g., greater than or equal to 400 MPa). Na ₂ O also improves formability of the glass-based substrate. However, if too much Na ₂ O is added to the glass-based substrate, the melting point may be too low. As such, in embodiments, the concentration of Li ₂ O present in the glass-based substrate may be greater than the concentration of Na ₂ O present in the glass-based substrate. In embodiments, the glass-based substrate may be greater than or equal to 0.5 mol% and less than or equal to 10 mol% Na ₂ O. In embodiments, the concentration of Na ₂ O in the glass-based substrate may be greater than or equal to 0.5 mol%, greater than or equal to 1 mol%, greater than or equal to 2 mol%, or even greater than or equal to 3 mol%. In embodiments, the concentration ofNa ₂ O in the glass-based substrate may be less than or equal to 10 mol%, less than or equal to 8 mol%, less than or equal to 6 mol%, or even less than or equal to 4 mol%. In embodiments, the concentration of Na ₂ O in the glass-based substrate may be greater than or equal to 0.5 mol% and less than or equal to 10 mol%, greater than or equal to 0.5 mol% and less than or equal to 8 mol%, greater than or equal to 0.5 mol% and less than or equal to 6 mol%, greater than or equal to 0.5 mol% and less than or equal to 4 mol%, greater than or equal to 1 mol% and less than or equal to 10 mol%, greater than or equal to 1 mol% and less than or equal to 8 mol%, greater than or equal to 1 mol% and less than or equal to 6 mol%, greater than or equal to 1 mol% and less than or equal to 4 mol%, greater than or equal to 2 mol% and less than or equal to 10 mol%, greater than or equal to 2 mol% and less than or equal to 8 mol%, greater than or equal to 2 mol% and less than or equal to 6 mol%, greater than or equal to 2 mol% and less than or equal to 4 mol%, greater than or equal to 3 mol% and less than or equal to 10 mol%, greater than or equal to 3 mol% and less than or equal to 8 mol%, greater than or equal to 3 mol% and less than or equal to 6 mol%, or even greater than or equal to 3 mol% and less than or equal to 4 mol%, or any and all sub-ranges formed from any of these endpoints.

[0063] K ₂ O promotes ion-exchange and may increase the depth of compression and decrease the melting point to improve the formability of the colored glass article. However, adding too much K ₂ O may cause the surface compressive stress and melting point to be too low. Accordingly, in embodiments, the amount of K ₂ O added to the glass composition may be limited. In embodiments, the glass-based substrate may comprise greater than or equal to 0 mol% and less than or equal to 1 mol% K ₂ O. In embodiments, the concentration of K ₂ O in the glass-based substrate may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, or even greater than or equal 0.2 mol%. In embodiments, the concentration of K ₂ O in the glass-based substrate may be less than or equal to 1 mol%, less than or equal to 0.8 mol%, less than or equal to 0.6 mol%, or even less than or equal to 0.4 mol%. In embodiments, the concentration of K ₂ O in the glass-based substrate may be greater than or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0 mol% and less than or equal to 0.8 mol%, greater than or equal to 0 mol% and less than or equal to 0.6 mol%, greater than or equal to 0 mol% and less than or equal to 0.4 mol%, greater than or equal to 0.1 mol% and less than or equal to 1 mol%, greater than or equal to 0.1 mol% and less than or equal to 0.8 mol%, greater than or equal to 0. 1 mol% and less than or equal to 0.6 mol%, greater than or equal to 0.1 mol% and less than or equal to 0.4 mol%, greater than or equal to 0.2 mol% and less than or equal to 1 mol%, greater than or equal to 0.2 mol% and less than or equal to 0.8 mol%, greater than or equal to 0.2 mol% and less than or equal to 0.6 mol%, or even greater than or equal to 0.2 mol% and less than or equal to 0.4 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass-based substrate may be free or substantially free of K ₂ O.

[0064] In embodiments, the glass-based substrate may include alkaline earth oxides, such as CaO, to decrease the melting point of the glass-based substrate. In embodiments, the glassbased substrate may comprise greater than or equal to 0 mol% and less than or equal to 3 mol% CaO. In embodiments, the concentration of CaO in the glass-based substrate may be greater than or equal to 0 mol%, greater than or equal to 0.25 mol%, or even greater than or equal to 0.5 mol%. In embodiments, the concentration of CaO in the glass-based substrate may be less than or equal to 3 mol%, less than or equal to 2 mol%, or even less than or equal to 1 mol%. In embodiments, the concentration of CaO in the glass-based substrate may be greater than or equal to 0 mol% and less than or equal to 3 mol%, greater than or equal to 0 mol% and less than or equal to 2 mol%, greater than or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0.25 mol% and less than or equal to 3 mol%, greater than or equal to 0.25 mol% and less than or equal to 2 mol%, greater than or equal to 0.25 mol% and less than or equal to 1 mol%, greater than or equal to 0.5 mol% and less than or equal to 3 mol%, greater than or equal to 0.5 mol% and less than or equal to 2 mol%, or even greater than or equal to 0.5 mol% and less than or equal to 1 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass-based substrate may be free or substantially free of CaO.

[0065] In embodiments, the glass-based substrate may comprise a fining agent, such as SnO ₂ . In embodiments, the glass-based substrate may comprise greater than or equal to 0 mol% and less than or equal to 1 mol% SnO ₂ . In embodiments, the concentration of SnO ₂ in the glassbased substrate may be greater than or equal to 0 mol% or even greater than or equal to 0.05 mol%. In embodiments, the concentration of SnO ₂ in the glass-based substrate may be less than or equal to 1 mol%, less than or equal to 0.5 mol%, less than or equal to 0.25 mol%, or even less than or equal to 0.1 mol%. In embodiments, the concentration of SnO ₂ in the glassbased substrate may be greater than or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0 mol% and less than or equal to 0.5 mol%, greater than or equal to 0 mol% and less than or equal to 0.25 mol%, greater than or equal to 0 mol% and less than or equal to 0.1 mol%, greater than or equal to 0.05 mol% and less than or equal to 1 mol%, greater than or equal to 0.05 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.05 mol% and less than or equal to 0.25 mol%, or even greater than or equal to 0.05 mol% and less than or equal to 0.1 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass-based substrate may be free or substantially free of SnO ₂ .

[0066] In embodiments, in addition to CuO, other colorants, such as Cr ₂ O ₃ , NiO, CoO, Co ₃ O ₄ , and/or TiO ₂ , may be included in the glass-based substrate to provide a desired color to the glass-based substrate.

[0067] In embodiments, the glass-based substrate may comprise greater than or equal to 0 mol% and less than or equal to 1 mol% Cr ₂ O ₃ . In embodiments, the concentration of Cr ₂ O ₃ in the glass-based substrate may be greater than or equal to 0 mol% or even greater than or equal to 0.01 mol%. In embodiments, the concentration of Cr ₂ O ₃ in the glass-based substrate may be less than or equal to 1 mol%, less than or equal to 0.5 mol%, less than or equal to 0.1 mol%, or even less than or equal to 0.05 mol%. In embodiments, the concentration of Cr ₂ O ₃ in the glass-based substrate may be greater than or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0 mol% and less than or equal to 0.5 mol%, greater than or equal to 0 mol% and less than or equal to 0.1 mol%, greater than or equal to 0 mol% and less than or equal to 0.05 mol%, greater than or equal to 0.01 mol% and less than or equal to 1 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.1 mol%, or even greater than or equal to 0.01 mol% and less than or equal to 0.05 mol%, or any and all sub -ranges formed from any of these endpoints. In embodiments, the glass-based substrate may be free or substantially free of Cr ₂ O ₃ .

[0068] In embodiments, the glass-based substrate may comprise greater than or equal to 0 mol% and less than or equal to 1 mol% NiO. In embodiments, the concentration of NiO in the glass-based substrate may be greater than or equal to 0 mol%, greater than or equal to 0.001 mol%, or even greater than or equal to 0.01 mol%. In embodiments, the concentration of NiO in the glass-based substrate may be less than or equal to 1 mol%, less than or equal to 0.5 mol%, less than or equal to 0.1 mol% or even less than or equal to 0.05 mol%. In embodiments, the concentration of NiO in the glass-based substrate may be greater than or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0 mol% and less than or equal to 0.5 mol%, greater than or equal to O mol% and less than or equal to 0.1 mol%, greater than or equal to 0 mol% and less than or equal to 0.05 mol%, greater than or equal to 0.001 mol% and less than or equal to 1 mol%, greater than or equal to 0.001 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.001 mol% and less than or equal to 0.1 mol%, greater than or equal to 0.001 mol% and less than or equal to 0.05 mol%, greater than or equal to 0.01 mol% and less than or equal to 1 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.1 mol%, or even greater than or equal to 0.01 mol% and less than or equal to 0.05 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glassbased substrate may be free or substantially free of NiO.

[0069] In embodiments, the glass-based substrate may comprise greater than or equal to 0 mol% and less than or equal to 1 mol% CoO. In embodiments, the concentration of CoO in the glass-based substrate may be greater than or equal to 0 mol% or even greater than or equal to 0.01 mol%. In embodiments, the concentration of CoO in the glass-based substrate may be less than or equal to 1 mol%, less than or equal to 0.5 mol%, less than or equal to 0. 1 mol%, or even less than or equal to 0.05 mol%. In embodiments, the concentration of CoO in the glass-based substrate may be greaterthan or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0 mol% and less than or equal to 0.5 mol%, greater than or equal to 0 mol% and less than or equal to 0.1 mol%, greater than or equal to 0 mol% and less than or equal to 0.05 mol%, greater than or equal to 0.01 mol% and less than or equal to 1 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.01 mol% and less than or equal to 0.1 mol%, or even greater than or equal to 0.01 mol% and less than or equal to 0.05 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass-based substrate may be free or substantially free of CoO.

[0070] In embodiments, the glass-based substrate may comprise greater than or equal to 0 mol% and less than or equal to 1 mol% Co ₃ O ₄ . In embodiments, the concentration of Co ₃ O ₄ in the glass-based substrate may be greaterthan or equal to 0 mol%, greater than or equal to 0.0001 mol%, or even greater than or equal to 0.001 mol%. In embodiments, the concentration of Co ₃ O ₄ in the glass-based substrate may be less than or equal to 1 mol%, less than or equal to 0.5 mol%, less than or equal to 0.1 mol%, less than or equal to 0.05, or even less than or equal to 0.01 mol%. In embodiments, the concentration of CO3O4 in the glass-based substrate may be greater than or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0 mol% and less than or equal to 0.5 mol%, greater than or equal to 0 mol% and less than or equal to 0.1 mol%, greater than or equal to 0 mol% and less than or equal to 0.05 mol%, greater than or equal to 0 mol% and less than or equal to 0.01 mol%, greater than or equal to 0.0001 mol% and less than or equal to 1 mol%, greater than or equal to 0.0001 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.0001 mol% and less than or equal to 0.1 mol%, greater than or equal to 0.0001 mol% and less than or equal to 0.05 mol%, greater than or equal to 0.0001 mol% and less than or equal to 0.01 mol%, greater than or equal to 0.001 mol% and less than or equal to 1 mol%, greater than or equal to 0.001 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.001 mol% and less than or equal to 0.1 mol%, greater than or equal to 0.001 mol% and less than or equal to 0.05 mol%, or even greater than or equal to 0.001 mol% and less than or equal to 0.01 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass-based substrate may be free or substantially free of Co ₃ O ₄ .

[0071] In embodiments, the glass-based substrate may comprise greater than or equal to 0 mol% and less than or equal to 1 mol% TiO ₂ . In embodiments, the concentration of TiO ₂ in the glass-based substrate may be greater than or equal to 0 mol%, greater than or equal to 0.05 mol%, or even greater than or equal to 0.1 mol%. In embodiments, the concentration of TiO ₂ in the glass-based substrate may be less than or equal to 1 mol%, less than or equal to 0.75 mol%, less than or equal to 0.5 mol%, or even less than or equal to 0.25 mol%. In embodiments, greater than or equal to 0 mol% and less than or equal to 1 mol%, greater than or equal to 0 mol% and less than or equal to 0.75 mol%, greater than or equal to 0 mol% and less than or equal to 0.5 mol%, greater than or equal to 0 mol% and less than or equal to 0.25 mol%, greater than or equal to 0.05 mol% and less than or equal to 1 mol%, greater than or equal to 0.05 mol% and less than or equal to 0.75 mol%, greater than or equal to 0.05 mol% and less than or equal to 0.5 mol%, greater than or equal to 0.05 mol% and less than or equal to 0.25 mol%, greaterthan or equal to 0.1 mol% and less than or equal to 1 mol%, greater than or equal to 0.1 mol% and less than or equal to 0.75 mol%, greater than or equal to 0.1 mol% and less than or equal to 0.5 mol%, or even greater than or equal to 0.1 mol% andless than or equal to 0.25 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass-based substrate may be free or substantially free of TiO ₂ . [0072] In embodiments, the glass-based substrate may comprise greater than or equal to 40 mol% and less than or equal to 70 mol% SiO ₂ ; greater than or equal to 4 mol% and less than or equal to 20 mol% A1 ₂ O ₃ ; greater than or equal to 1 mol% and less than or equal to 10 mol% B ₂ O ₃ ; greater than or equal to 5 mol% and less than or equal to 30 mol% Li ₂ O; greater than or equal to 0.5 mol% and less than or equal to 10 mol% Na ₂ O; and greater than or equal to 0.01 mol% to less than or equal to 2 mol% CuO.

[0073] In embodiments, the process for making a glass-based substrate includes heat treating a glass composition atone or more preselected temperatures for one or more preselected times to melt the glass composition and cooling the glass composition. In embodiments, the heat treatment for making a glass-based substrate may include (i) heating a glass composition at a rate of 1-100 °C/min to glass melting temperature; (ii) maintaining the glass composition at the glass melting temperature for a time greater than or equal to 4 hours and less than or equal to 100 hours to produce a glass-based substrate; and (iii) cooling the formed glass-based substrate to room temperature. In embodiments, the glass melting temperature may be greater than or equal to 1500 °C and less than or equal to 1700 °C.

[0074] The glass articles formed by the methods described herein do not include significant particle deposits on the surfaces thereof. An investigation of the surface deposits produced when other ion exchange methods are applied to copper containing glass substrates indicated that the particles were copper-containing or copper-rich. The glass articles produced by the method described herein may be free of copper-containing particles on the surfaces thereof. The density of copper containing deposits on the surface of the glass articles is determined by optical microscopy with reflected light (top lighting) at 500x magnification, and a chemically specific surface analysis technique (such as ToF-SIMs analysis with high mass resolution and spatial resolution of about 200 nm) at 500-1 OOOx magnification to confirm that the deposits are copper containing. A minimum surface area of 10,000 um ² is considered when determining the copper containing deposit concentration. In embodiments, the glass articles include a surface with an average copper containing deposit density of less than or equal to 10 deposits per 10,000 um ² , such as an average copper containing deposit density of less than or equal to 1.25 deposits per 10,000 um ² , an average copper containing deposit density of less than or equal to 1 deposit per 10,000 um ² , an average copper containing deposit density of less than or equal to 0.1 deposit per 10,000 um ² , or less. If the density of copper containing deposits on the surface of the glass-based article is too high, the surface will have an undesired hazy appearance.

[0075] As described herein, due to the presence of copper, the glass substrates and articles formed therefrom have relatively high L* values. More specifically, in a given a* and b* space (e.g., a* greater than or equal to -20 and less than or equal to 5 and b* greater than or equal to -20 and less than or equal to 12), glass-based substrates comprising greater than or equal to 0.01 mol% and less than or equal to 2 mol% CuO and articles formed therefrom may have relatively higher L* values as compared to glass-based articles lacking copper. In embodiments, the glass-based substrate and the glass-based article may have an L* value, as measured at an article thickness of 1.5 mm under F2 illumination and a 10° standard ob server angle, greater than or equal to 60, greater than or equal to 65, greater than or equal to 70, greater than or equal to 75, greater than or equal to 80, greater than or equal to 85, or even greater than or equal to 90. In embodiments, the glass-based substrate and the glass-based article may have an L* value, as measured at an article thickness of 1.5 mm under F2 illumination and a 10° standard observer angle, less than or equal to 97, less than or equal to 95, or even less than or equal to 93. In embodiments, tthe glass-based substrate and the glassbased article may have an L*, as measured at an article thickness of 1.5 mm under F2 illumination and a 10° standard observer angle, greater than or equal to 60 and less than or equal to 97, greater than or equal to 60 and less than or equal to 95, greater than or equal to 60 and less than or equal to 93, greater than or equal to 65 and less than or equal to 97, greater than or equal to 65 and less than or equal to 95, greater than or equal to 65 and less than or equal to 93, greater than or equal to 70 and less than or equal to 97, greater than or equal to 70 and less than or equal to 95, greater than or equal to 70 and less than or equal to 93, greater than or equal to 75 and less than or equal to 97, greater than or equal to 75 and less than or equal to 95, greater than or equal to 75 and less than or equal to 93, greater than or equal to 80 and less than or equal to 97, greater than or equal to 80 and less than or equal to 95, greater than or equal to 80 and less than or equal to 93, greater than or equal to 85 and less than or equal to 97, greater than or equal to 85 and less than or equal to 95, greater than or equal to 85 and less than or equal to 93, greater than or equal to 90 and less than or equal to 97, greater than or equal to 90 and less than or equal to 95, or even greater than or equal to 90 and less than or equal to 93, or any and all sub-ranges formed from any of these endpoints. [0076] In embodiments, the glass-based substrate and the glass-based article may have an a* value, as measured at an article thickness of 1 .5 mm under F2 illumination and a 10° standard observer angle, greater than or equal to -20, greater than or equal to -15, greater than or equal to -10, or even greater than or equal to -5. In embodiments, the glass-based substrate and the glass-based article may have an a* value, as measured at an article thickness of 1.5 mm under F2 illumination and a 10° standard observer angle, less than or equal to 5, less than or equal to 3, less than or equal to 1, less than or equal to -1, or even less than or equal to -3. In embodiments, the glass-based substrate and the glass-based article may have an a* value, as measured at an article thickness of 1.5 mm under F2 illumination and a 10° standard ob server angle, greater than or equal to -20 and less than or equal to 5, greater than or equal to -20 and less than or equal to 3 , greater than or equal to -20 and less than or equal to 1 , greater than or equal to -20 and less than or equal to -1, greater than or equal to -15 and less than or equal to 5, greater than or equal to -15 and less than or equal to 3, greater than or equal to -15 and less than or equal to 1, greater than or equal to -15 and less than or equal to -1, greater than or equal to -10 and less than or equal to 5, greater than or equal to -10 and less than or equal to 3 , greater than or equal to -10 and less than or equal to 1 , greater than or equal to -10 and less than or equal to -1, greater than or equal to -5 and less than or equal to 5, greater than or equal to -5 and less than or equal to 3 , greater than or equal to -5 and less than or equal to 1, or even greater than or equal to -5 and less than or equal to -1, or any and all sub-ranges formed from any of these endpoints.

[0077] In embodiments, the glass-based substrate and the glass-based article may have an b* value, as measured at an article thickness of 1 .5 mm under F2 illumination and a 10° standard observer angle, greater than or equal to -20, greater than or equal to -10, greater than or equal to -5, greater than or equal to -3, greater than or equal to -1, greater than or equal to 1, or even greater than or equal to 3. In embodiments, the glass-based substrate and the glass-based article may have an b* value, as measured at an article thickness of 1.5 mm under F2 illumination and a 10° standard observer angle, less than or equal to 12, less than or equal to 10, less than or equal to 8, or even less than or equal to 6. In embodiments, the glass-based substrate and the glass-based article may have an b* value, as measured at an article thickness of 1.5 mm under F2 illumination and a 10° standard observer angle, greater than or equal to - 20 and less than or equal to 12, greater than or equal to -20 and less than or equal to 10, greater than or equal to -20 and less than or equal to 8, greater than or equal to -20 and less than or equal to 6, greater than or equal to -10 and less than or equal to 12, greaterthan or equal to - 10 and less than or equal to 10, greater than or equal to -10 and less than or equal to 8, greater than or equal to -10 and less than or equal to 6, greater than or equal to -5 and less than or equal to 12, greater than or equal to -5 and less than or equal to 10, greater than or equal to -5 and less than or equal to 8, greater than or equal to -5 and less than or equal to 6, greater than or equal to -3 and less than or equal to 12, greater than or equal to -3 and less than or equal to 10, greater than or equal to -3 and less than or equal to 8, greater than or equal to -3 and less than or equal to 6, greater than or equal to - 1 and less than or equal to 12, greater than or equal to -1 and less than or equal to 10, greater than or equal to -1 and less than or equal to 8, greater than or equal to -1 and less than or equal to 6, greater than or equal to 1 and less than or equal to 12, greater than or equal to 1 and less than or equal to 10, greater than or equal to 1 and less than or equal to 8, greater than or equal to 1 and less than or equal to 6, greater than or equal to 3 and less than or equal to 12, greater than or equal to 3 and less than or equal to 10, greater than or equal to 3 and less than or equal to 8, or even greater than or equal to 3 and less than or equal to 6, or any and all sub-ranges formed from any of these endpoints.

[0078] In embodiments, a glass-based substrate comprises greater than or equal to 0.01 mol% and less than or equal to 2 mol% CuO and the glass-based substrate and a glass-based article formed therefrom may have a transmittance color coordinate in the CIELAB color space, as measured at an article thickness of 1.5 mm under F2 illumination and a 10° standard ob server angle, of L* greater than or equal to 60 and less than or equal to 97, a* greater than or equal to -20 and less than or equal to 5, and b* greater than or equal to -20 and less than or equal to 12. In embodiments, a copper containing glass-based substrate and glass-based article formed therefrom may be visually green or blue in color. As such, relatively higher L* values lead to relatively visually brighter green and blue colors.

[0079] The glass articles described herein may be used for a variety of applications including for example, back cover applications in consumer or commercial electronic devices such as smartphones, tablet computers, personal computers, ultrabooks, televisions, and cameras. An exemplary article incorporating any of the glass articles disclosed herein is shown in FIGS. 1 and 2. Specifically, FIGS. 1 and 2 show a consumer electronic device 100 including a housing 102 having front 104, back 106, and side surfaces 108; electrical components (not shown) that are at least partially inside or entirely within the housing and including at least a controller, a memory, and a display 110 at or adjacent to the front surface of the housing; and a cover substrate 112 at or over the front surface of the housing such that it is over the display. In embodiments, at least a portion of housing 102, such as the back 106, may include any of the glass articles disclosed herein.

Examples

[0080] In order that various embodiments be more readily understood, reference is made to the following examples, which illustrate various embodiments of the methods described herein.

[0081] Particle Defects

[0082] An exemplary glass substrate had a composition of 61.3 wt% (58.4 mol%) SiO ₂ , 15.1 wt% (8.5 mol%) A1 ₂ O ₃ , 6 wt% (4.9 mol%) B ₂ O ₃ , 12.1 wt% (23.2 mol%) Li ₂ O, 4.1 wt% (3.8 mol%) Na ₂ O, 0.4 wt% (0.2 mol%) K ₂ O, 0.75 wt% (0.8 mol%) CaO, 0.0281 wt% (0.0106 mol%) Cr ₂ O ₃ , 0.009 wt% (0.0069 mol%) NiO, 0.0028 wt% (0.0007 mol%) Co ₃ O ₄ , and 0.2337 wt% (0.1682 mol%) CuO.

[0083] A comparative example was ion exchanged in molten salt bath at 380 °C for 9.5 hours, the molten salt bath included 72 g NaNO ₃ , 323.6 gKNO ₃ , 8.4 g LiNO ₃ , 2 g silicic acid, and 4.8 g TSP. The comparative example had a cloudy surface appearance, as shown in FIG. 3 which is an edge-lit picture of the comparative example.

[0084] After the ion exchange of the comparative example, 4 g (~1 wt%) of silicic acid was added to the bath and the bath was aged for 30 minutes. The exemplary glass substrate was then ion exchanged at the same salt bath temperature for the same time period as the comparative example. The example glass article produced after the addition of the silicic acid did not exhibit a hazy surface appearance after ion exchange, as shown in FIG. 4 which is an edge-lit picture of the example glass article.

[0085] Optical microscope images of the comparative example and example glass articles described above were taken to confirm that the hazy appearance of the comparative example glass article was due to the presence of particulate defects on the surface. A shown in FIG. 5, the surface of the comparative example glass article included a large number of particulate defects. By contrast, the optical microscope image of the example glass article shown in FIG. 6 does not include particulate defects. [0086] SIMS analysis of the comparative example and example glass articles described above were taken to confirm that the particulate defects on the surface were copper-rich. A shown in FIG. 7, the surface of the comparative example glass article included a large number of copper-rich particulate defects. By contrast, the surface of the example glass article does not include copper-rich particles, as shown in FIG. 8.

[0087] Lightness Values

[0088] Glass substrates were formed with a base glass composition including 58.20 wt% (61.40 mol%) SiO ₂ , 24.22 wt% (15.06 mol%) A1 ₂ O ₃ , 6.47 wt% (5.89 mol%) B ₂ O ₃ , 5.76 wt% (12.21 mol%) Li ₂ O, 3.86 wt% (3.94 mol%) Na ₂ O, 0.57 wt% (0.39 mol%) K ₂ O, 0.66 wt% (0.75 mol%) CaO, 0.20 wt% (0.082 mol%) SnO ₂ , 0.040 wt% (0.034 mol%)NiO, and 0.21 wt% (0.17 mol%) TiO ₂ . As shown in Table 1, comparative glass substrates C1-C18 were formed from the base glass composition and also included from 0.039 mol% to 0.063 mol% Fe ₂ O ₃ , from 0.0495 mol%to 0.050 mol% Cr ₂ O ₃ , and from 0.0061 to 0.0113 mol% Co ₃ O4. As shown in Table 2, example glass substrates E1-E58 were formed from the base composition and also included from0.0025 mol%to 0.0063 mol% Co ₃ O4, from 0.030 mol% to 0.041 mol% Cr ₂ O ₃ , and from 0.0014 mol% and 0.0151 mol% CuO. The transmittance color coordinates in the CIELAB color space, as measured at an article thickness of 1.5 mm under F2 illumination and a 10° standard observer angle, for each of the glass-based substrates are shown in the tables.

[0089] Table 1

[0090] Table 2

[0091] Referring now to FIG. 9, comparative glass substrates C1-C18 (shown as triangles), glass substrates lacking copper, exhibited L* values from 88.72 to 90.5. Example glass substrates E49-E58 (shown as circles), glass substrates including copper, exhibited L* values from 90.5 to 91. Example glass substrates E11-E48 (shown as squares), glass substrates including copper, exhibited L* values from 91 to 91 .72. Example glass substrates El -E10 (shown as diamonds), glass substrates including copper, exhibited L* values from 91.72 to 92.72. As exemplified by Tables 1 and 2 andFIG. 9, copper containing glass substrates have relatively higher L* values in a given a* and b* space as compared to glass substrates lacking copper.

[0092] It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, itis intended thatthe specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.