Patent Publication Number: US-2021188685-A1

Title: Contoured glass articles and methods of making the same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 62/506,024 filed on May 15, 2017, the content of which is relied upon and incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The present disclosure relates generally to the field of three-dimensional (3D) shaped glass for various applications including for automotive interiors. 
     There is interest in automotive displays having curved or conformal shapes (“conformal displays”) that can be integrated into the dashboard, console, or other auto interior locations that have a curved surface or partially curved surface. Such displays can include liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, micro light emitting diode (microLED) displays, and other displays. In addition, there is also interest in using a contoured cover glass to provide additional mechanical stability and reliability to the automotive displays. 
     Conformal shapes in displays and cover glass in automotive applications have been limited to shaping the cover glass, while the underlying displays are flat and rigid. The cover glass has been shaped by either hot forming or cold bending processes. Hot forming heats the glass to a temperature greater than its softening point to permanently bend the glass to the desired shape. Hot form processes can produce a variety of 3D shapes but adds significant cost. Moreover, hot formed glass need to be thermally shaped and then strengthened (e.g., by an ion exchange process). In contrast, in cold bending is performed at significantly lower temperatures (often room temperature); however, the achievable bend radius and shapes can be limited when glass sheets of constant thicknesses are used (i.e., such shapes may be limited to basic U- and S-curves with larger bend radii). More complex shapes create significant stress in the cold bent glass. moreover, decreasing the bend radius creates high bend stress in cold bent glass and requires more substantial mechanical frames or a strong adhesive to hold the cold bent glass in the correct shape due to overall stiffness. 
     Accordingly, there is a need for conformal displays and/or contoured cover glass shapes having high display quality and mechanical reliability. 
     SUMMARY 
     The present disclosure described embodiments of a method of making contoured glass articles and embodiments of the resulting contoured glass articles. 
     In one or more embodiments, the method of making a contoured glass article comprises cold bending a flat glass sheet having first and second opposing major surfaces, at least one region having a first thickness, and at least one region having a second thickness, to produce cold bent glass sheet having at least one bend region along a portion of the at least one region having the second thickness; and restraining the cold bent glass sheet to produce the contoured glass article, wherein the first thickness is greater than the second thickness. In one or more specific embodiments, cold bending and the retaining the cold bent glass sheet are accomplished sequentially or simultaneously. 
     In one or more embodiments, the contoured glass article comprising: a cold bent glass sheet having first and second opposing major surfaces, at least one region having a first thickness, at least one region having a second thickness, and at least one bend region along a portion of the at least one region having the second thickness, wherein the first thickness is greater than the second thickness. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are cross-sectional views of cold bent glass sheets having uniform thickness and  FIGS. 1C and 1D  are cross-sectional views of cold bent glass sheets having one or two localized thinned and cold-bent regions (each indicated by an arrow), according to one or more embodiments of this disclosure. 
         FIGS. 2A and 2B  are cross-sectional views of cold bent glass sheets having one or two localized thinned and cold-bent regions (each indicated by an arrow), according to one or more embodiments of this disclosure. 
         FIG. 3A  shows the cold-bent glass sheet of  FIG. 2B  (without a localized thinned region) that cannot neatly accommodate a functional item such as a display. 
         FIG. 3B  shows the cold bent glass sheet of  FIG. 2D  (with a localized thinned region) that can accommodate a functional item such as a display because of reduced curvature or superior flatness in the thinned region for attaching the functional item), according to one or more embodiments of this disclosure. 
         FIG. 4  schematically shows an example of a glass article according to one or more embodiments of this disclosure including a cold bent glass sheet, a frame (not shown) having localized thinning that can accommodate a functional item such as a display. 
         FIG. 5  is a side view illustration of a flat glass sheet according to one or more embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments of the disclosure will be described in detail with reference to drawings, if any. Reference to various embodiments does not limit the scope of the invention, which is limited only by the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not limiting and merely set forth some of the many possible embodiments of the claimed invention. 
     Definitions 
     “Cold bending,” “cold bend,” and like terms refer to bending a glass article at a temperature below the glass transition temperature (T g ) of the glass. Cold-bending can occur, for example, at below 800° C., such as at 700, 600, 500, 400, 300, 280, 200, 100, 50, and 25° C., including intermediate values and ranges. A feature of a cold-bent glass article is asymmetric surface compressive stress between a first major surface  11 ,  111  and the second major surface  12 ,  112  as shown in  FIGS. 1A and 1C . In one or more embodiments, prior to the cold-bending process or being cold-bent, the respective compressive stresses in the first major surface  11 ,  111  and the second major surface  12 ,  112  of the glass article are substantially equal. In one or more embodiments in which the glass article is unstrengthened, the first major surface  11 ,  111  and the second major surface  12 ,  112  exhibit no appreciable compressive stress, prior to cold-bending. In one or more embodiments in which the glass article is strengthened (as described herein), the first major surface  11 ,  111  and the second major surface  12 ,  112  exhibit substantially equal compressive stress with respect to one another, prior to cold-bending. In one or more embodiments, after cold-bending (shown, for example, in  FIGS. 1A and 1C ), the compressive stress on the surface having a concave shape after bending (e.g., first major surface  11 ,  111  in  FIGS. 1A and 1C ) increases. In other words, the compressive stress on the concave surface (e.g., first major surface  11 ,  111 ) is greater after cold-bending than before cold-bending. Without being bound by theory, the cold-bending process increases the compressive stress of the glass article being shaped to compensate for tensile stresses imparted during bending and/or forming operations. In one or more embodiments, the cold-bending process causes the concave surface (first major surface  11 ,  111 ) to experience compressive stresses, while the surface forming a convex shape (i.e., the second major surface  12 ,  112  in  FIGS. 12, 112 ) after cold-bending experiences tensile stresses. The tensile stress experienced by the convex surface (i.e., the second major surface  12 ,  112 ) following cold-bending results in a net decrease in surface compressive stress, such that the compressive stress in convex surface (i.e., the second major surface  12 ,  112 ) of a strengthened glass article following cold-bending is less than the compressive stress on the same surface (i.e., second major surface  12 ,  112 ) when the glass article is flat. When a strengthened glass article is utilized, the first major surface and the second major surface comprise a compressive stress that is substantially equal to one another prior to cold-bending, and thus the first major surface can experience greater tensile stress during cold-bending without risking fracture. This allows for the strengthened glass article to conform to more tightly curved surfaces or shapes. 
     “IOX,” “IOXing,” “IOX&#39;ed,” “ion-exchange,” “ion-exchanging,” or like terms refer to the ion exchange of ions, partially or completely, on at least a portion of the glass surface, on one or both sides as specified, with different ions such as an ion having a larger atomic radius compared to the exchanged ions such as K +  ions exchanged (i.e., replacing) for Na +  ions. 
     “Bend radius,” “radius,” or like terms refer to is the minimum radius measured to the inside curvature, alternatively or additionally, the maximum bend one can bend a glass sheet without damaging it or shortening its life. The smaller the bend radius, the greater is the material flexibility. A related term is “radius of curvature”. As the radius of curvature of the bent part or piece decreases, the curvature increases; a large radius of curvature represents a low curvature and a small radius of curvature represents high curvature. 
     Specific and preferred values disclosed for components, ingredients, additives, dimensions, conditions, times, and like aspects, and ranges thereof, are for illustration only; they do not exclude other defined values or other values within defined ranges. The composition and methods of the disclosure can include any value or any combination of the values, specific values, more specific values, and preferred values described herein, including explicit or implicit intermediate values and ranges. 
     A first aspect of this disclosure pertains to a contoured glass article as shown in  FIGS. 1C-1D, 2A-2B, 3B and 4 . As used herein, the phrase “contoured glass article” refers to a glass article that has been bent into a curved shape. The contoured glass article can be curved via cold bending as described herein. In one or more embodiments, the contoured glass article includes a cold bent glass sheet having a first major surface  111  (as shown in  FIG. 1C ), a second major surface  112  opposing the first major surface (or second opposing major surface), at least one region having a first thickness  115 , at least one region having a second thickness  116 , and at least one bend region  117  along a portion of the at least one region having the second thickness. In one or more embodiments, the first thickness  115  is greater than the second thickness  116 . In one or more embodiments, the contoured glass article further includes a frame  150  (as shown in  FIG. 2A ) attached to the second major surface  112  to retain the at least one bend region. In one or more alternative embodiments, the frame  150  maybe attached to the first major surface  111 . 
     In one or more embodiments, the contoured glass article (or the flat glass sheet that is used to form the contoured glass article) has a first thickness  115  that is about 2 mm or less, or about 1.5 mm or less. For example, the first thickness may be in a range from about 0.01 mm to about 1.5 mm, 0.02 mm to about 1.5 mm, 0.03 mm to about 1.5 mm, 0.04 mm to about 1.5 mm, 0.05 mm to about 1.5 mm, 0.06 mm to about 1.5 mm, 0.07 mm to about 1.5 mm, 0.08 mm to about 1.5 mm, 0.09 mm to about 1.5 mm, 0.1 mm to about 1.5 mm, from about 0.15 mm to about 1.5 mm, from about 0.2 mm to about 1.5 mm, from about 0.25 mm to about 1.5 mm, from about 0.3 mm to about 1.5 mm, from about 0.35 mm to about 1.5 mm, from about 0.4 mm to about 1.5 mm, from about 0.45 mm to about 1.5 mm, from about 0.5 mm to about 1.5 mm, from about 0.55 mm to about 1.5 mm, from about 0.6 mm to about 1.5 mm, from about 0.65 mm to about 1.5 mm, from about 0.7 mm to about 1.5 mm, from about 0.01 mm to about 1.4 mm, from about 0.01 mm to about 1.3 mm, from about 0.01 mm to about 1.2 mm, from about 0.01 mm to about 1.1 mm, from about 0.01 mm to about 1.05 mm, from about 0.01 mm to about 1 mm, from about 0.01 mm to about 0.95 mm, from about 0.01 mm to about 0.9 mm, from about 0.01 mm to about 0.85 mm, from about 0.01 mm to about 0.8 mm, from about 0.01 mm to about 0.75 mm, from about 0.01 mm to about 0.7 mm, from about 0.01 mm to about 0.65 mm, from about 0.01 mm to about 0.6 mm, from about 0.01 mm to about 0.55 mm, from about 0.01 mm to about 0.5 mm, from about 0.01 mm to about 0.4 mm, from about 0.01 mm to about 0.3 mm, from about 0.01 mm to about 0.2 mm, from about 0.01 mm to about 0.1 mm, from about 0.04 mm to about 0.07 mm, from about 0.1 mm to about 1.4 mm, from about 0.1 mm to about 1.3 mm, from about 0.1 mm to about 1.2 mm, from about 0.1 mm to about 1.1 mm, from about 0.1 mm to about 1.05 mm, from about 0.1 mm to about 1 mm, from about 0.1 mm to about 0.95 mm, from about 0.1 mm to about 0.9 mm, from about 0.1 mm to about 0.85 mm, from about 0.1 mm to about 0.8 mm, from about 0.1 mm to about 0.75 mm, from about 0.1 mm to about 0.7 mm, from about 0.1 mm to about 0.65 mm, from about 0.1 mm to about 0.6 mm, from about 0.1 mm to about 0.55 mm, from about 0.1 mm to about 0.5 mm, from about 0.1 mm to about 0.4 mm, or from about 0.3 mm to about 0.7 mm. 
     In one or more embodiments, the contoured glass article (and/the flat glass sheet that is used to form the contoured glass article) has a second thickness  116  that is less than the first thickness. In one or more embodiments, the first thickness is in a range from about 500 micrometers to about 2 mm, and the second thickness is in a range from about 10% to 90% of the first thickness (e.g., from about 10% to about 85%, from about 10% to about 80%, from about 10% to about 75%, from about 10% to about 70%, from about 10% to about 65%, from about 10% to about 60%, from about 10% to about 55%, from about 10% to about 50%, from about 10% to about 45%, from about 20% to about 90%, from about 25% to about 90%, from about 30% to about 90%, from about 35% to about 90%, from about 40% to about 90%, from about 45% to about 90%, from about 50% to about 90%, from about 55% to about 90%, from about 60% to about 90%, or from about 65% to about 90%). In one or more embodiments, the first thickness is in a range from greater than about 500 micrometers to about 2 mm, and the second thickness is in a range from about 300 micrometers to less than 500 micrometers. In some embodiments, the regions of first thickness can have a size having at least one linear dimension of from greater than or equal to one of 5, 10, 20, 50, 100 mm, and like thicknesses, including intermediate values and ranges. The regions of second thickness can have a size having at least one linear dimension of from greater than or equal to one of: 5, 10, 20, 50, 100 mm, and like thicknesses, including intermediate values and ranges. The thickness transition, for example a taper or step(s), between a first thickness and a second thickness can occur with a linear dimension of less than or equal to one of from 1, 10, 20, 50, 100 microns, and 1, 5, 10, 50, 100 mm, and like transition thicknesses, including intermediate values and ranges. 
     In one or more embodiments, the contoured article (and/or the flat glass sheet that is used to form the contoured glass article) has a, width (W) defined as a first maximum dimension of one of the first or second major surfaces, and a length (L) defined as a second maximum dimension of one of the first or second surfaces orthogonal to the width. The width and/or length of the flat glass sheet may be greater than width and/or length of the same glass sheet after cold bending into the contoured glass article because of the curvature in the contoured glass article. 
     In one or more embodiments, the contoured glass article (and/or the flat glass sheet that is used to form the contoured glass article) has a width (W) in a range from about 5 cm to about 250 cm, from about 10 cm to about 250 cm, from about 15 cm to about 250 cm, from about 20 cm to about 250 cm, from about 25 cm to about 250 cm, from about 30 cm to about 250 cm, from about 35 cm to about 250 cm, from about 40 cm to about 250 cm, from about 45 cm to about 250 cm, from about 50 cm to about 250 cm, from about 55 cm to about 250 cm, from about 60 cm to about 250 cm, from about 65 cm to about 250 cm, from about 70 cm to about 250 cm, from about 75 cm to about 250 cm, from about 80 cm to about 250 cm, from about 85 cm to about 250 cm, from about 90 cm to about 250 cm, from about 95 cm to about 250 cm, from about 100 cm to about 250 cm, from about 110 cm to about 250 cm, from about 120 cm to about 250 cm, from about 130 cm to about 250 cm, from about 140 cm to about 250 cm, from about 150 cm to about 250 cm, from about 5 cm to about 240 cm, from about 5 cm to about 230 cm, from about 5 cm to about 220 cm, from about 5 cm to about 210 cm, from about 5 cm to about 200 cm, from about 5 cm to about 190 cm, from about 5 cm to about 180 cm, from about 5 cm to about 170 cm, from about 5 cm to about 160 cm, from about 5 cm to about 150 cm, from about 5 cm to about 140 cm, from about 5 cm to about 130 cm, from about 5 cm to about 120 cm, from about 5 cm to about 110 cm, from about 5 cm to about 110 cm, from about 5 cm to about 100 cm, from about 5 cm to about 90 cm, from about 5 cm to about 80 cm, or from about 5 cm to about 75 cm. 
     In one or more embodiments, the contoured glass article (and/or the flat glass sheet that is used to form the contoured glass article) has a length (L) in a range from about 5 cm to about 250 cm, from about 10 cm to about 250 cm, from about 15 cm to about 250 cm, from about 20 cm to about 250 cm, from about 25 cm to about 250 cm, from about 30 cm to about 250 cm, from about 35 cm to about 250 cm, from about 40 cm to about 250 cm, from about 45 cm to about 250 cm, from about 50 cm to about 250 cm, from about 55 cm to about 250 cm, from about 60 cm to about 250 cm, from about 65 cm to about 250 cm, from about 70 cm to about 250 cm, from about 75 cm to about 250 cm, from about 80 cm to about 250 cm, from about 85 cm to about 250 cm, from about 90 cm to about 250 cm, from about 95 cm to about 250 cm, from about 100 cm to about 250 cm, from about 110 cm to about 250 cm, from about 120 cm to about 250 cm, from about 130 cm to about 250 cm, from about 140 cm to about 250 cm, from about 150 cm to about 250 cm, from about 5 cm to about 240 cm, from about 5 cm to about 230 cm, from about 5 cm to about 220 cm, from about 5 cm to about 210 cm, from about 5 cm to about 200 cm, from about 5 cm to about 190 cm, from about 5 cm to about 180 cm, from about 5 cm to about 170 cm, from about 5 cm to about 160 cm, from about 5 cm to about 150 cm, from about 5 cm to about 140 cm, from about 5 cm to about 130 cm, from about 5 cm to about 120 cm, from about 5 cm to about 110 cm, from about 5 cm to about 110 cm, from about 5 cm to about 100 cm, from about 5 cm to about 90 cm, from about 5 cm to about 80 cm, or from about 5 cm to about 75 cm. 
     In one or more embodiments, the contoured glass article (and/or the flat glass sheet that is used to form the contoured glass article) has a surface area in a range from about 10 cm 2 to about 50,000 cm 2    
     Suitable glass compositions for use in the contoured glass article (or flat glass sheet used to form the contoured glass article) include soda lime glass, aluminosilicate glass, borosilicate glass, boroaluminosilicate glass, alkali-containing aluminosilicate glass, alkali-containing borosilicate glass, and alkali-containing boroaluminosilicate glass. In one or more embodiments, the contoured glass article (or flat glass sheet used to form the contoured glass article) may be a single composition layer or may include multiple layers of different compositions and thicknesses. 
     In one or more embodiments, at least one of first major surface  111 , and the second major surface  112  may be unstrengthened, annealed or heat strengthened. In embodiments in which at least one of first major surface  111 , and the second major surface  112  may be unstrengthened, annealed or heat strengthened, such surface may exhibit a surface compressive stress of less than 120 MPa, less than 100 MPa, less than 75 MPa or less than 50 MPa). In one or more embodiments, at least one of the first major surface  111 , and the second major surface  112  may exhibit no ion-exchanged surfaces. 
     In one or more embodiments, at least one of the first and second major surfaces or both the first and second major surfaces of the contoured glass article is strengthened. In one or more embodiments, the flat glass sheet used to form the contoured glass article may be strengthened before forming into the contoured glass article. Such strength characteristics may be present in the final contoured glass article (with any additional characteristics attributable to cold bending such as the different in surface compressive stress between the first major surface and the second major surface, as described herein). 
     In one or more embodiments, the strengthened contoured glass article may include a compressive stress that extends from a surface (typically one of or both the first and second major surfaces) to a depth of compression or depth of compressive stress layer (DOC). The compressive stress at the surface is referred to as the surface CS. The CS regions are balanced by a central portion exhibiting a tensile stress. At the DOC, the stress crosses from a compressive stress to a tensile stress. The compressive stress and the tensile stress are provided herein as absolute values. 
     In one or more embodiments, the contoured glass article may be strengthened by any one or combinations of a thermal strengthening process, a chemical strengthening process and a mechanical strengthening process. In one or more embodiments, the contoured glass article (or flat glass sheet) may be mechanically strengthened by utilizing a mismatch of the coefficient of thermal expansion between portions of the article to create a compressive stress region and a central region exhibiting a tensile stress. In some embodiments, the contoured glass article (or flat glass sheet) may be thermally strengthened by heating the glass to a temperature above the glass transition point and then rapidly quenching. 
     In one or more embodiments, the contoured glass article (or flat glass sheet) may be chemically strengthened by ion exchange. In the ion exchange process, ions at or near the surface of the contoured glass article (or flat glass sheet) are replaced by—or exchanged with—larger ions having the same valence or oxidation state. In embodiments in which the contoured glass article comprises an alkali aluminosilicate glass, ions in the surface layer of the article and the larger ions are monovalent alkali metal cations, such as Li+, Na+, K+, Rb+, and Cs+. Alternatively, monovalent cations in the surface layer may be replaced with monovalent cations other than alkali metal cations, such as Ag+ or the like. In such embodiments, the monovalent ions (or cations) exchanged into the contoured glass article (or flat glass sheet) generate a stress. It should be understood that any alkali metal oxide containing glass article (or flat glass sheet) can be chemically strengthened by an ion exchange process. 
     Ion exchange processes are typically carried out by immersing a glass article (or flat glass sheet) in a molten salt bath (or two or more molten salt baths) containing the larger ions to be exchanged with the smaller ions in the glass article (or flat glass sheet). It should be noted that aqueous salt baths may also be utilized. In addition, the composition of the bath(s) may include more than one type of larger ion (e.g., Na+ and K+) or a single larger ion. It will be appreciated by those skilled in the art that parameters for the ion exchange process, including, but not limited to, bath composition and temperature, immersion time, the number of immersions of the glass article in a salt bath (or baths), use of multiple salt baths, additional steps such as annealing, washing, and the like, are generally determined by the composition of the glass article (including the structure of the article and any crystalline phases present) and the desired DOC and CS of the glass article that results from strengthening. Exemplary molten bath composition may include nitrates, sulfates, and chlorides of the larger alkali metal ion. Typical nitrates include KNO3, NaNO3, LiNO3, NaSO4 and combinations thereof. The temperature of the molten salt bath typically is in a range from about 380° C. up to about 450° C., while immersion times range from about 15 minutes up to about 100 hours depending on glass article (or flat glass sheet) thickness, bath temperature and glass (or monovalent ion) diffusivity. However, temperatures and immersion times different from those described above may also be used. 
     In one or more embodiments, the glass articles (or flat glass sheet) may be immersed in a molten salt bath of 100% NaNO3, 100% KNO3, or a combination of NaNO3 and KNO3 having a temperature from about 370° C. to about 480° C. In some embodiments, the glass article (or flat glass sheet) may be immersed in a molten mixed salt bath including from about 1% to about 99% KNO3 and from about 1% to about 99% NaNO3. In one or more embodiments, the glass article (or flat glass sheet) may be immersed in a second bath, after immersion in a first bath. The first and second baths may have different compositions and/or temperatures from one another. The immersion times in the first and second baths may vary. For example, immersion in the first bath may be longer than the immersion in the second bath. 
     In one or more embodiments, the glass article (or flat glass sheet) may be immersed in a molten, mixed salt bath including NaNO3 and KNO3 (e.g., 49%/51%, 50%/50%, 51%/49%) having a temperature less than about 420° C. (e.g., about 400° C. or about 380° C.). for less than about 5 hours, or even about 4 hours or less. 
     Ion exchange conditions can be tailored to provide a “spike” or to increase the slope of the stress profile at or near the surface of the resulting glass article (or flat glass sheet). The spike may result in a greater surface CS value. This spike can be achieved by single bath or multiple baths, with the bath(s) having a single composition or mixed composition, due to the unique properties of the glass compositions used in the glass articles (or flat glass sheet) described herein. 
     In one or more embodiments, where more than one monovalent ion is exchanged into the glass article (or flat glass sheet), the different monovalent ions may exchange to different depths within the glass article (and generate different magnitudes stresses within the glass article at different depths). The resulting relative depths of the stress-generating ions can be determined and cause different characteristics of the stress profile. 
     CS is measured using those means known in the art, such as by surface stress meter (FSM) using commercially available instruments such as the FSM-6000, manufactured by Orihara Industrial Co., Ltd. (Japan). Surface stress measurements rely upon the accurate measurement of the stress optical coefficient (SOC), which is related to the birefringence of the glass. SOC in turn is measured by those methods that are known in the art, such as fiber and four point bend methods, both of which are described in ASTM standard C770-98 (2013), entitled “Standard Test Method for Measurement of Glass Stress-Optical Coefficient,” the contents of which are incorporated herein by reference in their entirety, and a bulk cylinder method. As used herein CS may be the “maximum compressive stress” which is the highest compressive stress value measured within the compressive stress layer. In some embodiments, the maximum compressive stress is located at the surface of the glass article. In other embodiments, the maximum compressive stress may occur at a depth below the surface, giving the compressive profile the appearance of a “buried peak.” 
     DOC may be measured by FSM or by a scattered light polariscope (SCALP) (such as the SCALP-04 scattered light polariscope available from Glasstress Ltd., located in Tallinn Estonia), depending on the strengthening method and conditions. When the glass article is chemically strengthened by an ion exchange treatment, FSM or SCALP may be used depending on which ion is exchanged into the glass article. Where the stress in the glass article is generated by exchanging potassium ions into the glass article, FSM is used to measure DOL. Where the stress is generated by exchanging sodium ions into the glass article, SCALP is used to measure DOL. Where the stress in the glass article is generated by exchanging both potassium and sodium ions into the glass, the DOC is measured by SCALP, since it is believed the exchange depth of sodium indicates the DOC and the exchange depth of potassium ions indicates a change in the magnitude of the compressive stress (but not the change in stress from compressive to tensile); the exchange depth of potassium ions in such glass articles is measured by FSM. Central tension or CT is the maximum tensile stress and is measured by SCALP. 
     In one or more embodiments, the glass article (or flat glass sheet) maybe strengthened to exhibit a DOC that is described a fraction of the thickness t of the glass article (as described herein). For example, in one or more embodiments, the DOC may be equal to or greater than about 0.05 t, equal to or greater than about 0.1 t, equal to or greater than about 0.11 t, equal to or greater than about 0.12 t, equal to or greater than about 0.13 t, equal to or greater than about 0.14 t, equal to or greater than about 0.15 t, equal to or greater than about 0.16 t, equal to or greater than about 0.17 t, equal to or greater than about 0.18 t, equal to or greater than about 0.19 t, equal to or greater than about 0.2 t, equal to or greater than about 0.21 t. In some embodiments, the DOC may be in a range from about 0.08 t to about 0.25 t, from about 0.09 t to about 0.25 t, from about 0.18 t to about 0.25 t, from about 0.11 t to about 0.25 t, from about 0.12 t to about 0.25 t, from about 0.13 t to about 0.25 t, from about 0.14 t to about 0.25 t, from about 0.15 t to about 0.25 t, from about 0.08 t to about 0.24 t, from about 0.08 t to about 0.23 t, from about 0.08 t to about 0.22 t, from about 0.08 t to about 0.21 t, from about 0.08 t to about 0.2 t, from about 0.08 t to about 0.19 t, from about 0.08 t to about 0.18 t, from about 0.08 t to about 0.17 t, from about 0.08 t to about 0.16 t, or from about 0.08 t to about 0.15 t. In some instances, the DOC may be about 20 μm or less. In one or more embodiments, the DOC may be about 40 μm or greater (e.g., from about 40 μm to about 300 μm, from about 50 μm to about 300 μm, from about 60 μm to about 300 μm, from about 70 μm to about 300 μm, from about 80 μm to about 300 μm, from about 90 μm to about 300 μm, from about 100 μm to about 300 μm, from about 110 μm to about 300 μm, from about 120 μm to about 300 μm, from about 140 μm to about 300 μm, from about 150 μm to about 300 μm, from about 40 μm to about 290 μm, from about 40 μm to about 280 μm, from about 40 μm to about 260 μm, from about 40 μm to about 250 μm, from about 40 μm to about 240 μm, from about 40 μm to about 230 μm, from about 40 μm to about 220 μm, from about 40 μm to about 210 μm, from about 40 μm to about 200 μm, from about 40 μm to about 180 μm, from about 40 μm to about 160 μm, from about 40 μm to about 150 μm, from about 40 μm to about 140 μm, from about 40 μm to about 130 μm, from about 40 μm to about 120 μm, from about 40 μm to about 110 μm, or from about 40 μm to about 100 μm. 
     In one or more embodiments, the strengthened contoured glass article (or flat glass sheet) may have a CS (which may be found at the surface or a depth within the glass article) of about 200 MPa or greater, 300 MPa or greater, 400 MPa or greater, about 500 MPa or greater, about 600 MPa or greater, about 700 MPa or greater, about 800 MPa or greater, about 900 MPa or greater, about 930 MPa or greater, about 1000 MPa or greater, or about 1050 MPa or greater. In one or more embodiments, the strengthened contoured glass article (or flat glass sheet) may have a CS (which may be found at the surface or a depth within the glass article) from about 200 MPa to about 1500 MPa, from about 250 MPa to about 1500 MPa, from about 300 MPa to about 1500 MPa, from about 350 MPa to about 1500 MPa, from about 400 MPa to about 1500 MPa, from about 450 MPa to about 1500 MPa, from about 500 MPa to about 1500 MPa, from about 550 MPa to about 1500 MPa, from about 600 MPa to about 1500 MPa, from about 200 MPa to about 1400 MPa, from about 200 MPa to about 1300 MPa, from about 200 MPa to about 1200 MPa, from about 200 MPa to about 1100 MPa, from about 200 MPa to about 1050 MPa, from about 200 MPa to about 1000 MPa, from about 200 MPa to about 950 MPa, from about 200 MPa to about 900 MPa, from about 200 MPa to about 850 MPa, from about 200 MPa to about 800 MPa, from about 200 MPa to about 750 MPa, from about 200 MPa to about 700 MPa, from about 200 MPa to about 650 MPa, from about 200 MPa to about 600 MPa, from about 200 MPa to about 550 MPa, or from about 200 MPa to about 500 MPa. 
     In one or more embodiments, the strengthened contoured glass article (or flat glass sheet) may have a maximum tensile stress or central tension (CT) of about 20 MPa or greater, about 30 MPa or greater, about 40 MPa or greater, about 45 MPa or greater, about 50 MPa or greater, about 60 MPa or greater, about 70 MPa or greater, about 75 MPa or greater, about 80 MPa or greater, or about 85 MPa or greater. In some embodiments, the maximum tensile stress or central tension (CT) may be in a range from about 40 MPa to about 100 MPa, from about 50 MPa to about 100 MPa, from about 60 MPa to about 100 MPa, from about 70 MPa to about 100 MPa, from about 80 MPa to about 100 MPa, from about 40 MPa to about 90 MPa, from about 40 MPa to about 80 MPa, from about 40 MPa to about 70 MPa, or from about 40 MPa to about 60 MPa. 
     After a strengthening process, the resulting strengthened contoured glass article (or flat glass sheet) can include a symmetric stress profile or an asymmetric stress profile. A symmetric stress profile exists when both major surfaces of the glass article are symmetrically chemical strengthened and exhibit substantially the same surface compressive stress and depth of compressive stress layer. In one or more embodiments, the resulting strengthened glass article can exhibit an asymmetric stress profile exists in which the glass article exhibits different surface compressive stress on one major surface compared to the opposing major surface, at locations on each major surface that are directly opposite from one another. In one or more embodiments, an asymmetric stress profile may be generated or an existing asymmetric stress profile may be enhanced (to have greater asymmetry) from cold-bending the flat glass sheet, as described herein. 
     In one or more embodiments, the contoured glass article may include a plurality of regions having the second thickness. For example, in  FIGS. 1D, 2B and 3B , the glass article includes a plurality of regions having the second thickness. In one or more embodiments, the contoured glass article may include a plurality of bend regions. In the embodiments shown at  FIGS. 1D, 2B and 3B , each bend region is located at a region having the second thickness; however, it is possible to have fewer bend regions than regions with the second thickness and greater bend regions than regions with the second thickness. 
     In one or more embodiments, the contoured glass article may include at least one bend region below a plane and at least one bend region above the plane. The plane in such embodiments is defined by as a midpoint of a maximum cross-sectional dimension. 
     In one or more embodiments, the at least one bend region has a bend radius (measured at the concave surface) of about 20 mm or greater, 40 mm or greater, 50 mm or greater, 60 mm or greater, 100 mm or greater, 250 mm or greater or 500 mm or greater. In one or more embodiments, the bend radius is in a range from about 50 mm to about 10,000 mm. For example, the bend radius may be in a range from about 20 mm to about 1500 mm, from about 30 mm to about 1500 mm, from about 40 mm to about 1500 mm, from about 50 mm to about 1500 mm, 60 mm to about 1500 mm, from about 70 mm to about 1500 mm, from about 80 mm to about 1500 mm, from about 90 mm to about 1500 mm, from about 100 mm to about 1500 mm, from about 120 mm to about 1500 mm, from about 140 mm to about 1500 mm, from about 150 mm to about 1500 mm, from about 160 mm to about 1500 mm, from about 180 mm to about 1500 mm, from about 200 mm to about 1500 mm, from about 220 mm to about 1500 mm, from about 240 mm to about 1500 mm, from about 250 mm to about 1500 mm, from about 260 mm to about 1500 mm, from about 270 mm to about 1500 mm, from about 280 mm to about 1500 mm, from about 290 mm to about 1500 mm, from about 300 mm to about 1500 mm, from about 350 mm to about 1500 mm, from about 400 mm to about 1500 mm, from about 450 mm to about 1500 mm, from about 500 mm to about 1500 mm, from about 550 mm to about 1500 mm, from about 600 mm to about 1500 mm, from about 650 mm to about 1500 mm, from about 700 mm to about 1500 mm, from about 750 mm to about 1500 mm, from about 800 mm to about 1500 mm, from about 900 mm to about 1500 mm, from about 950 mm to about 1500 mm, from about 1000 mm to about 1500 mm, from about 1250 mm to about 1500 mm, from about 20 mm to about 1400 mm, from about 20 mm to about 1300 mm, from about 20 mm to about 1200 mm, from about 20 mm to about 1100 mm, from about 20 mm to about 1000 mm, from about 20 mm to about 950 mm, from about 20 mm to about 900 mm, from about 20 mm to about 850 mm, from about 20 mm to about 800 mm, from about 20 mm to about 750 mm, from about 20 mm to about 700 mm, from about 20 mm to about 650 mm, from about 20 mm to about 200 mm, from about 20 mm to about 550 mm, from about 20 mm to about 500 mm, from about 20 mm to about 450 mm, from about 20 mm to about 400 mm, from about 20 mm to about 350 mm, from about 20 mm to about 300 mm, from about 20 mm to about 250 mm, from about 20 mm to about 200 mm, from about 20 mm to about 150 mm, from about 20 mm to about 100 mm, from about 20 mm to about 50 mm, from about 60 mm to about 1400 mm, from about 60 mm to about 1300 mm, from about 60 mm to about 1200 mm, from about 60 mm to about 1100 mm, from about 60 mm to about 1000 mm, from about 60 mm to about 950 mm, from about 60 mm to about 900 mm, from about 60 mm to about 850 mm, from about 60 mm to about 800 mm, from about 60 mm to about 750 mm, from about 60 mm to about 700 mm, from about 60 mm to about 650 mm, from about 60 mm to about 600 mm, from about 60 mm to about 550 mm, from about 60 mm to about 500 mm, from about 60 mm to about 450 mm, from about 60 mm to about 400 mm, from about 60 mm to about 350 mm, from about 60 mm to about 300 mm, or from about 60 mm to about 250 mm. In one or more embodiments, glass articles having a first thickness or second thickness of less than about 0.4 mm may exhibit a bend radius that is less than about 100 mm, or less than about 60 mm. 
     As shown in  FIGS. 3B and 5 , the contoured glass article may include a display and/or touch panel ( 200 ,  430 ) disposed behind the at least one region having the second thickness. In one or more embodiments, the display and/or touch panel may be disposed behind the at least one region having the first thickness. In one or more embodiments, a display panel and/or touch panel may be disposed behind both the at least one region having the first thickness and the at least one region having the second thickness. 
     In one or more embodiments, the contoured glass article is a window glass, a structural glass, a glass component of a vehicle, or a combination thereof. 
     A second aspect of this disclosure pertains to a method of making a contoured glass article. 
     In or more embodiments of the method of making a contoured glass article comprises cold bending a flat glass sheet  100 . In one or more embodiments, as shown in  FIG. 5 , the flat glass sheet  100  has a first major surface  111 , an second major surface  112  that opposes the first major surface (or second opposing major surfaces ( 111 ,  112 , as shown in  FIG. 1C  and  FIG. 5 ), at least one region having a first thickness  115 , and at least one region having a second thickness  116 , wherein the first thickness is greater than the second thickness. In one or more embodiments, the method includes cold bending the flat glass sheet  100  to produce a cold bent glass sheet as shown in  FIG. 1C  having at least one bend region (indicated by an arrow) along a portion of the at least one region having the second thickness ( 116 ). In one or more embodiments, the method includes cold bending the flat glass sheet to produce a cold bent glass sheet having more than one bend region, as shown in  FIG. 1D . 
     In one or more embodiments, the method includes restraining the cold bent glass sheet to produce the contoured glass article, which still exhibits the first thickness that is greater than the second thickness. In one or more embodiments, restraining the cold bent glass sheet includes placing the cold bent glass sheet in a retaining frame that retains the cold bent glass sheet in a curved configuration or maintains the at least one bend in the cold bent glass sheet. The cold bent glass sheet may be placed in a retaining frame under tension. An adhesive or mechanical fasteners may be used to place and maintain the cold bent glass in the retaining frame. In one or more embodiments, restraining the cold bent glass sheet includes contacting the cold bent glass sheet with a pre-formed shape and an adhesive to bond the cold bent glass sheet to the pre-formed shape resulting in the contoured glass article. 
       , 
     In one or more embodiments, cold bending the glass sheet and the retaining the cold bent glass sheet (e.g., placing the cold bent glass sheet in the retaining frame) can be accomplished sequentially or simultaneously. 
       , 
     In one or more embodiments, the method includes strengthening the flat glass sheet before cold bending. For example, The flat glass sheet may be strengthened by any one or combinations of a thermal strengthening process, a chemical strengthening process and a mechanical strengthening process as described above with respect to the contoured glass article. 
     In one or more embodiments, the method may include strengthening at least one major surface of the cold bent glass sheet. For example, the at least one major surface or both major surfaces of the cold bent glass sheet may be strengthened thermally, mechanically or chemically as described herein. 
     In one or more embodiments, the flat glass sheet has a plurality of regions having the second thickness. In one or embodiments, the cold bent glass sheet may include a single bend region or a plurality of bend regions. 
     In one or more embodiments, the cold bent glass sheet can have, for example, at least one bend below a plane and at least one bend above a plane, the plane being defined by the plane of the first flat glass sheet. 
     In embodiments, the method includes thinning the flat glass sheet locally. For example, the method includes localized thinning of the flat glass sheet during or after formation of the glass article or a cover glass. In one or more embodiments, localized thinning of the flat glass sheet occurs during forming of the flat glass sheet and includes local stretching or drawing of the flat glass sheet. As used herein, this forming step is not used to create a bend. Instead, by thinning during the forming step, glass is locally heated and drawn (or stretched) so that the localized region is thinner than unheated and undrawn regions of the sheet. In one or more embodiments, the method may include strengthening the flat glass sheet with the locally thinned region formed by drawing and then subsequently cold bending the sheet with the bending occurring primarily in the thinner, more flexible region. 
     Examples of thinning after forming of the glass sheet include subtractive processes such as wet etching, dry etching, and sandblasting, which removes portions of the flat glass sheet to thin localized regions. 
     In one or more embodiments, the method of making a contoured glass article includes: localized thinning of a flat glass sheet in one or more regions or areas where a high bend or biaxial stress will occur. In one or more embodiments, after thinning, the flat glass sheet can be cold bent at or near the thinned region to a desired shape. The disclosed thinning and bending method produces lower stress in the cold bent glass sheet and/or the contoured glass article compared cold bent glass sheets or contoured glass articles having a constant thickness (which are shown in  FIGS. 1A and 1B ). Since the stiffness of the glass sheet or article is related to the cube of the glass thickness, i.e., (thickness) 3 , a thinned and cold bent glass sheet or contoured article made according to embodiments of the present disclosure also reduces the retaining mechanism requirements or requirements for the frame required to restrain a cold-bent glass sheet into a contoured glass article throughout its life. Specifically, a cold bent glass sheet or contoured glass article having locally reduced thickness (i e , thinned) experiences lower bend or biaxial stresses when in the bent configuration at the thinned location compared to at a thicker location. Similarly, a glass article having locally reduced stiffness requires less force from a retaining mechanism or framing structure to maintain the contoured glass article in a curved shape. These results in turn can provide a contoured product having reduced weight and reduced cost of the mechanical framing structure placed around the contoured glass article or a display/touch panel. 
     The embodiments described herein have the following exemplary advantages:
         the ability to achieve contoured glass articles with bends having a smaller bend radius;   the ability to achieve contoured glass articles with complex, permanent curvatures;   the ability to achieve contoured glass articles with increased mechanical reliability due to reduction of bend stresses;   the ability to achieve contoured glass articles with reduced mechanical framing required to hold the shaped glass after cold bending throughout the products life;   the ability to integrate larger displays into the contoured glass articles (i.e., displays can be bent along the bent regions to better match the curve of the contoured glass article and thus would not be limited to placement at flat regions);   the ability to achieve contoured glass articles at lower processing costs compared to hot forming methods; and   the ability to position a bend region(s) of a contoured glass article in a location where it is needed, which positioning permits display areas to remain flat and regions between displays to be curved.       

     Referring to the Figures,  FIGS. 1A to 1B  show a glass sheet that has been bent into shapes having constant thickness. In contrast,  FIGS. 1C and 1D  show cold bent glass sheets having similar shapes but have thinned regions at the locations where significant curvature occurs in the glass sheet. Curvatures made to the glass sheet can be positioned in regions or areas that have been locally thinned. The thicker regions in the glass sheet can remain flat or less curved compared to the thinned region(s). The thicker regions are potential locations for displays to be integrated or attached. In this instance, the parts can be bent into simple U- and S-shapes. More complex scenarios are also possible if the glass is thinned in more complex  2 D patterns across its surface or if the display is also locally thinned  FIGS. 1A and 1B  show cold bent glass sheets of constant thickness in simple U- and S-curves.  FIGS. 1C and 1D  show cold bent glass sheets having a first thickness and a second thickness, and having at least one region or side of localized thinning (see arrows). Localized thinning of glass sheets in areas where glass curves are to be made reduce the bend stress and the stiffness. A reduced stiffness of the resulting contoured glass article reduces the magnitude of the mechanical frame needed. The flatness of the non-thinned areas can also be increased if desired, and allows for straight forward display integration. 
     A locally thinned glass sheets can have displays (or other devices) integrated in the flat, thicker regions. The glass sheet can be locally thinned on either one or on both major surfaces. If the glass sheet is thinned on both surfaces, the thinned regions on each surface can be either aligned (i.e., coincident or co-located) or offset from each other. 
     In embodiments, the disclosure provides a method of making a display where a 3D glass form is selected and avoids excess stress on a display surface. In embodiments, the method provides for cold bending a flat glass sheet, having at least one region with a first thickness and at least one region with a second thickness, which leaves thicker or flatter areas situated between the bends for the display region. 
     In one or embodiments, the embodiments, the disclosure provides a contoured glass article, a display, and methods of making the same. In embodiments, the disclosure provides a contoured glass article and the integrated display (or other device). The contoured glass article can be an ion exchanged glass or another glass that can serve as a mechanical cover sheet for the display or device below it. In embodiments, the first thickness can be 3 mm or thinner including, for example, less than 1 mm, less than 0.7 mm, less than 0.5 mm, and less than 0.3 mm. The displays that may be integrated or combined with the contoured glass article include: LC displays, OLED displays, microLED displays, OLED lighting, touch sensors, speakers, instrument displays, and like other electronic devices. 
     In addition to display applications, the disclosed method and articles can be used in non-display applications that call for a shaped glass article that has bends or curves, for example, automotive lighting, instrument panels, touch sensors, mobile phone bodies, and like structures and uses. 
     In one or more alternative embodiments, instead of thinning the flat glass sheet in a simple single zone across its width, the method includes thinning the flat glass sheet in more complex patterns permits reduction of bend and biaxial stress as the glass article is subsequently cold bent in more complex 3D curvatures (thinning in this instance can be accomplished in the cover glass specifically where high stress would occur in the complex curvature). Such embodiments enable a reduction of stresses when the glass sheet is bent and mechanically isolates bends in different directions. Specific portions of the glass sheet can remain thicker where flatness, stiffness, or both properties are important Thinning can be located in specific regions where local 2D or 3D bending or mechanical isolation is desired.). 
     In one or more alternative embodiments, instead of just locally thinning the flat glass sheet or contoured glass article, the display (or other device) can also be locally thinned. This enables cold bending of the display (or other device) in shapes that match the cover glass. 
     In one or more embodiments, local thinning can also be used to create a pocket, groove, shallow, or like thinned region, for the display (or other device) to be positioned into and as shown schematically in  FIG. 4 .  FIG. 4  schematically shows an example of a glass article ( 400 ) of the disclosure that in embodiments can include a shaped glass piece ( 410 ) having a locally thinned area ( 420 ), which thinned area can accommodate a display element ( 430 ). 
     In embodiments, local thinning can also be used on glass sheets or articles having both hot formed and cold formed shapes to improve reliability and reduce system integration costs for complex surface designs. 
     In embodiments of the present process, local thinning of a display can be accomplished on the flat glass sheet either before or after the device fabrication has been completed. In one or more embodiments, local thinning of a flat glass sheet can occur before strengthening (e.g., by ion exchange) has been accomplished. In this instance, the flat glass sheet can be uniformly strengthened at a constant depth in regions both with and without local thinning In this example, the ion exchange process can occur on locally thinned individual glass sheets or on a larger sized glass sheet. If individual glass sheets are used, they can be ion exchanged while flat or while held in complex shapes (i.e., as a cold bent glass sheet). 
     In embodiments, local thinning of the flat glass sheet can occur after an ion exchange step has been accomplished. In this instance, the areas of local thinning create an asymmetric stress profile assuming it is primarily etched on a single side. If the glass sheet is etched on both sides, the DOC and/or surface CS may still remain symmetric. This asymmetric etching highlights the possibility that a locally thinned part need not be uniformly ion exchanged across its surface. 
     In embodiments, local thinning can be accomplished by etching, and the etching can also be used to produce, for example, anti-glare or other effects. 
     In embodiments, local thinning can be accomplished after the cold bent glass sheet has been restrained (e.g., by placing in a frame). After the cold bent glass is in a frame, the glass can then be locally thinned by, for example, a subtractive process. A reason for this order of events is that it can be easier to handle the glass when it is in a frame. 
     In embodiments, local thinning can be applied to glass articles that contain both hot formed and cold formed shapes. The thinning can be accomplished as part of the hot forming process or as a post-process treatment for a hot formed part. In embodiments, local thinning can also be accomplished with parts having both hot formed and cold formed regions. 
     In embodiments, local thinning of sheets can be accomplished by etching or re-drawing. In the instance of re-drawing, this can also occur while hot forming processes are performed to shape the part. 
     In embodiments, any etching used for local thinning can be accomplished during processes that also produce through-hole vias. 
     In embodiments, local thinning of sheets can be accomplished on individual parts or on larger size panels. 
     In embodiments, local thinning of sheets can have a different ion exchange or composition profile compared to the other areas of the glass. 
     In embodiments, locally thinned regions or sections can have an etched surface on either face of the article, or on both faces of the article. 
     EXAMPLES 
     The following Examples demonstrate making, use, and analysis of the disclosed methods in accordance with the above general procedures. 
     Example 1 (PROPHETIC) 
     Sequential Processing A flat glass sheet, having at least one region having a first thickness and at least one region having a second thickness (the first thickness is greater than the second thickness), is cold bent to produce a second glass sheet having at least one bend. The cold bent glass sheet having the at least one bend is placed in or restrained in a fixture to produce a contoured glass article held in a fixture. 
     Example 2 (PROPHETIC) 
     Simultaneous Processing A first flat glass sheet, having at least one region having a first thickness and at least one region having a second thickness (the first thickness is greater than the second thickness), is simultaneously placed in or restrained in a fixture and cold bent to simultaneously produce a cold bent glass sheet having at least one bend and a contoured glass article held in a fixture. 
     Example 3 (PROPHETIC) 
     A flat glass sheet, having at least one region having a first thickness and at least one region having a second thickness, the first thickness is greater than the second thickness, is integrated with another element besides the frame, and cold bent. This cold bending can occur either before or after integration of the additional element. The integrated element can be, for example, an electronic display, another electronic or opto-electronic device, or optical element such as a mirror or element having a visual pattern. 
     Example 4 (PROPHETIC) 
     A flat glass sheet, having at least one region having a first thickness and at least one region having a second thickness (the first thickness is greater than the second thickness), integrated with an automotive application such as dashboard, console, door, within the automotive interior, on the automotive exterior, or other. 
     Aspect (1) of this disclosure pertains to a method of making a contoured glass article comprising: cold bending a flat glass sheet having first and second opposing major surfaces, at least one region having a first thickness, and at least one region having a second thickness, to produce cold bent glass sheet having at least one bend region along a portion of the at least one region having the second thickness; and restraining the cold bent glass sheet to produce the contoured glass article, wherein the first thickness is greater than the second thickness. 
     Aspect (2) of this disclosure pertains to the method of Aspect (1), wherein the cold bending and the retaining the cold bent glass sheet are accomplished sequentially or simultaneously. 
     Aspect (3) of this disclosure pertains to the method of Aspect (1) or Aspect (2), wherein at least one of the first and second major surfaces of the flat glass sheet is unstrengthened, annealed or heat strengthened. 
     Aspect (4) of this disclosure pertains to the method of any one of Aspects (1) through (3), wherein at least one of the first and second major surfaces of the flat glass sheet is strengthened. 
     Aspect (5) of this disclosure pertains to the method of Aspects (1) through (4), further comprising strengthening at least one of the first and second major surfaces of cold bent glass sheet. 
     Aspect (6) of this disclosure pertains to the method of Aspects (1) through (5), wherein the flat glass sheet has a plurality of regions having the second thickness. 
     Aspect (7) of this disclosure pertains to the method of Aspects (1) through (6), wherein the cold bent glass sheet has a single bend region or a plurality of bend regions. 
     Aspect (8) of this disclosure pertains to the method of Aspects (1) through (7), wherein the cold bent glass sheet has at least one bend below a plane and at least one bend above the plane, the plane being defined by the plane of the flat glass sheet. 
     Aspect (9) of this disclosure pertains to the method of Aspects (1) through (8), wherein the first thickness is in a range from about 500 micrometers to about 2 mm, and the second thickness is in a range from about 10% to 90% of the first thickness. 
     Aspect (10) of this disclosure pertains to the method of Aspects (1) through (9), wherein the first thickness is in a range from greater than about 500 micrometers to about 2 mm, and the second thickness is in a range from about 300 micrometers to less than 500 micrometers. 
     Aspect (11) of this disclosure pertains to the method of Aspects (1) through (10), wherein the at least one bend region has a bend radius in a range from about 50 mm to about 10,000 mm. 
     Aspect (12) of this disclosure pertains to the method of Aspects (1) through (11), further comprising disposing the contoured glass article over a display or touch panel, wherein the display or touch panel is positioned behind the at least one region having the first thickness. 
     Aspect (13) of this disclosure pertains to the method of Aspects (1) through (10), further comprising attaching a display or touch panel to the at least one region having the first thickness. 
     Aspect (14) of this disclosure pertains to a contoured glass article comprising:
         a cold bent glass sheet having first and second opposing major surfaces, at least one region having a first thickness, at least one region having a second thickness, and at least one bend region along a portion of the at least one region having the second thickness, wherein the first thickness is greater than the second thickness.       

     Aspect (15) of this disclosure pertains to the contoured glass article of Aspect (14), further comprising a frame attached to the second major surface to retain the at least one bend region. 
     Aspect (16) of this disclosure pertains to the contoured glass article of Aspect (14) or Aspect (15), wherein at least one of the first and second major surfaces is unstrengthened, annealed or heat strengthened. 
     Aspect (17) of this disclosure pertains to the contoured glass article of any one of Aspects (14) through (16), wherein at least one of the first and second major surfaces is strengthened. 
     Aspect (18) of this disclosure pertains to the contoured glass article of any one of Aspects (14) through (17), comprising a plurality of regions having the second thickness. 
     Aspect (19) of this disclosure pertains to the contoured glass article of any one of Aspects (14) through (18), further comprising a plurality of bend regions. 
     Aspect (20) of this disclosure pertains to the contoured glass article of any one of Aspects (14) through (19), further comprising at least one bend region below a plane and at least one bend region above the plane, the plane being defined by as a midpoint of a maximum cross-sectional dimension. 
     Aspect (21) of this disclosure pertains to the contoured glass article of any one of Aspects (14) through (20), wherein the first thickness is in a range from about 500 micrometers to about 2 mm, and the second thickness is in a range from about 10% to 90% of the first thickness. 
     Aspect (22) of this disclosure pertains to the contoured glass article of any one of Aspects (14) through (21), wherein the first thickness is ion a range from greater than about 500 micrometers to about 2 mm, and the second thickness is in a range from about 300 micrometers to less than 500 micrometers. 
     Aspect (23) of this disclosure pertains to the contoured glass article of any one of Aspects (14) through (22), wherein the at least one bend region has a bend radius in a range from about 50 mm to about 10,000 mm. 
     Aspect 24) of this disclosure pertains to the contoured glass article of any one of Aspects (14) through (23), further comprising a display or touch panel disposed behind the at least one region having the second thickness. 
     Aspect (25) of this disclosure pertains to the contoured glass article of any one of Aspects (14) through (24), wherein the contoured glass article is a window glass, a structural glass, a glass component of a vehicle, or a combination thereof. 
     The disclosure has been described with reference to various specific embodiments and techniques. However, it should be understood that many variations and modifications are possible while remaining within the scope of the disclosure.