Method of forming and adjusting local transmittance contrast in glass-ceramic articles by laser bleaching

Abstract

A method of bleaching a glass-ceramic article is disclosed. The method includes illuminating a first portion of the body by directing a light beam from a laser to a thickness of the glass-ceramic article body to heat the first portion and form a first aperture therein. The body is configured to have an amorphous silicate glass phase, a crystalline phase, and a body transmittance. The first aperture is configured to have a first transmittance greater than the body transmittance at a first wavelength of about 350 nm to about 2500 nm. The light beam from the laser is configured to include a bleaching wavelength selected from a laser band within which residual absorption is continuously present in the aperture after illumination at the bleaching wavelength.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority under 35 U.S.C. §119 to U.S. Provisional Application No. 63 / 349,617, filed on June 7, 2022, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates generally to glass-ceramics and more particularly to forming and adjusting local transmittance contrasts in glass-ceramics using laser irradiation. Background Art

[0004] Some products require highly transparent apertures to be optically separated or isolated from each other, for example, by an opaque material in the middle of the apertures. In existing configurations, this optical separation can be achieved by precision machining an opaque material and a separate portion of a highly transparent material different from the opaque material, and then arranging the highly transparent material portion in the opaque material. However, precision machining and arranging different materials to achieve this optical separation can be complex and expensive. Therefore, there is a need for a bleachable monolithic glass-ceramic material that is configured for bleaching to provide one or more highly transparent apertures in the bleached region of the material and high light absorbance in the unbleached region of the material, thereby optically isolating the apertures. It would be very advantageous to provide this optical separation within a predetermined wavelength range. Summary of the invention

[0005] A first aspect of the present disclosure includes a method of bleaching a glass-ceramic article, comprising: irradiating a first portion of the body by directing a beam of light from a laser into the thickness of the glass-ceramic article to heat the first portion and form a first aperture therein, the body having an amorphous silicate glass phase, a crystalline phase, and a body transmittance, the first aperture having a first transmittance greater than the body transmittance at a first wavelength of 350 nm to 2500 nm, the beam of light comprising a bleaching wavelength selected from a laser wavelength band, within the laser wavelength band, residual absorption persists in the aperture after irradiation at the bleaching wavelength.

[0006] A second aspect of the present disclosure includes the method according to the first aspect, wherein the laser wavelength bands include at least two non-overlapping laser wavelength bands.

[0007] A third aspect of the present disclosure includes the method according to the first aspect or the second aspect, wherein the laser wavelength band includes a lower laser wavelength band adjacent to and / or overlapping with a lower end of the first wavelength.

[0008] The fourth aspect of the present disclosure includes the method according to any one of the first to third aspects, wherein the laser band includes a higher laser band adjacent to and / or overlapping with the upper end of the first wavelength.

[0009] The fifth aspect of the present disclosure includes the method according to any one of the first to fourth aspects, wherein in terms of transmittance, within the laser band, the residual absorption persists in the orifice after irradiation in a range of about 5% / mm to about 85% / mm.

[0010] The sixth aspect of the present disclosure includes the method according to any one of the first to fifth aspects, wherein the crystalline phase contains M x WO3 substance, where 0 < x < 1, and where M is an intercalated doping cation.

[0011] The seventh aspect of the present disclosure includes the method according to the sixth aspect, wherein the M x WO3 substance corresponds to the main absorption substance into which the bleaching wavelength is coupled during the irradiation.

[0012] The eighth aspect of the present disclosure includes the method according to the seventh aspect, wherein the body contains a secondary absorption substance into which the bleaching wavelength is coupled during the irradiation, the secondary absorption substance being different from the main absorption substance, so as to provide the residual absorption.

[0013] The ninth aspect of the present disclosure includes the method according to the eighth aspect, wherein the secondary absorption substance contains chemical hydroxyl groups.

[0014] The tenth aspect of the present disclosure includes the method according to the eighth or ninth aspect, wherein the secondary absorption substance includes the ultraviolet (UV) absorption edge of the glass phase.

[0015] The eleventh aspect of the present disclosure includes the method according to any one of the eighth to tenth aspects, wherein the secondary absorption substance contains a dopant, and the method further includes doping the body with the dopant before the irradiation.

[0016] The twelfth aspect of the present disclosure includes the method according to the eleventh aspect, wherein the dopant includes one or more of Ce, Er, Tb, Pr, Mn, Ti, Cu, Co, Ni, Fe, Cr, V, Ag, and Au in the form of oxides or metals.

[0017] The thirteenth aspect of the present disclosure includes the method according to the eleventh or twelfth aspect, wherein the body contains less than 2.5 mol% of dopants selected from: Ce, Er, Pr, Tb, and combinations thereof.

[0018] A fourteenth aspect of the present disclosure includes a method according to any one of aspects eleven to thirteen, wherein the body contains less than 0.5 mol% of a dopant selected from the group consisting of: Mn, Ti, Cu, Co, Ni, Fe, Cr, V, Ag, Au, and combinations thereof.

[0019] A fifteenth aspect of the present disclosure includes a method according to any one of the sixth to fourteenth aspects, wherein the irradiation is configured to heat the first portion of the body to a point where the M of the crystalline phase x The WO3 substance is substantially dissolved to the dissolution temperature in the body.

[0020] A sixteenth aspect of the present disclosure includes the method according to the fifteenth aspect, wherein the dissolution temperature is higher than the M x The liquidus temperature of WO3 substance.

[0021] A seventeenth aspect of the present disclosure includes the method according to the fifteenth aspect or the sixteenth aspect, wherein the dissolution temperature is in the range of about 600°C to about 1,100°C.

[0022] An eighteenth aspect of the present disclosure includes the method according to any one of the fifteenth to seventeenth aspects, wherein the dissolution temperature is in the range of about 900°C to about 1,100°C.

[0023] A nineteenth aspect of the present disclosure includes a method according to any one of the first to eighteenth aspects, wherein directing a beam from a laser includes adjusting a focus of the beam so that a maximum temperature is not exceeded within the first portion of the body during irradiation.

[0024] A twentieth aspect of the present disclosure includes the method of any one of the first to nineteenth aspects, wherein the laser includes a mid-infrared (IR) laser, and the light beam is directed from the mid-infrared laser using a plurality of laser parameters.

[0025] A twenty-first aspect of the present disclosure includes the method of aspect 20, wherein the laser parameters include a laser power in a range of about 17.5 W to about 39.0 W.

[0026] A twenty-second aspect of the present disclosure includes the method of aspect 20, wherein the laser parameters include a laser power in the range of about 25.0 W to about 30.0 W.

[0027] A twenty-third aspect of the present disclosure includes the method according to any one of aspects 20 to 22, wherein the laser parameters include a beam spot size in the range of about 0.20 mm to about 1.50 mm.

[0028] A twenty-fourth aspect of the present disclosure includes the method according to any one of the twentieth to twenty-second aspects, wherein the laser parameters include a beam spot size in the range of about 0.40 mm to about 1.0 mm.

[0029] A twenty-fifth aspect of the present disclosure includes the method according to any one of the twentieth to twenty-fourth aspects, wherein the laser parameters include an irradiation time in the range of about 0.70 s to about 12.0 s.

[0030] A twenty-sixth aspect of the present disclosure includes the method according to any one of the twentieth to twenty-fourth aspects, wherein the laser parameters include an irradiation time in the range of about 0.40 s to about 8.0 s.

[0031] A twenty-seventh aspect of the present disclosure includes the method according to any one of aspects 20 to 26, wherein the laser parameters are configured to form a first aperture having a target diameter.

[0032] A twenty-eighth aspect of the present disclosure includes the method according to the twenty-seventh aspect, wherein the target diameter is in the range of about 0.2 mm to about 5 mm.

[0033] A twenty-ninth aspect of the present disclosure includes a method according to any one of aspects one to twenty-eight, wherein the irradiating further comprises irradiating a second portion of the body by directing the light beam from the laser into the thickness of the body to heat the second portion and form a second aperture therein, the second aperture having a second transmittance greater than the body transmittance at the first wavelength.

[0034] A thirtieth aspect of the present disclosure includes the method of the twenty-ninth aspect, wherein the second aperture is spaced apart from the first aperture.

[0035] A thirty-first aspect of the present disclosure includes a method according to the twenty-ninth aspect or the thirtieth aspect, wherein the irradiation to form the first aperture and the irradiation to form the second aperture are performed simultaneously.

[0036] A thirty-second aspect of the present disclosure includes a method according to the twenty-ninth aspect or the thirtieth aspect, wherein the irradiation to form the first orifice and the irradiation to form the second orifice are performed sequentially with a dwell time in between.

[0037] A thirty-third aspect of the present disclosure includes a method according to any one of aspects 29 to 32, further comprising contacting a first heat sink portion with a first surface of a body configured to be irradiated, the first heat sink portion defining a corresponding first through hole, and a light beam from a laser being guided or passing through the first through hole to form the first opening and the second opening in the body.

[0038] A thirty-fourth aspect of the present disclosure includes a method according to the thirty-third aspect, which further includes contacting a second heat sink portion with a second surface of the body, the second surface being opposite to the first surface so that the first heat sink portion and the second heat sink portion sandwich the body in between.

[0039] A thirty-fifth aspect of the present disclosure includes a method according to the thirty-fourth aspect, wherein the second heat sink portion defines a corresponding second through hole, and the light beam from the laser is guided or passes through the second through hole to form the first aperture and the second aperture in the body.

[0040] A thirty-sixth aspect of the present disclosure includes the method according to any one of the first to thirty-fifth aspects, further comprising preheating the glass-ceramic article prior to the irradiating.

[0041] A thirty-seventh aspect of the present disclosure includes the method according to the thirty-sixth aspect, wherein the preheating includes heating the glass-ceramic article to a preheating temperature in a range of about 100°C to about 600°C.

[0042] A thirty-eighth aspect of the present disclosure includes the method of the thirty-sixth aspect, wherein the preheating includes heating the glass-ceramic article to a preheating temperature in a range of about 200°C to about 575°C.

[0043] A thirty-ninth aspect of the present disclosure includes the method of the thirty-sixth aspect, wherein the preheating includes heating the glass-ceramic article to a preheating temperature in a range of about 300°C to about 500°C.

[0044] A fortieth aspect of the present disclosure includes the method according to any one of the first to thirty-ninth aspects, further comprising annealing the glass-ceramic article by heating the glass-ceramic article to an annealing temperature.

[0045] A forty-first aspect of the present disclosure includes a method according to the fortieth aspect, wherein the annealing temperature is outside a threshold temperature so as to substantially maintain the first transmittance, and wherein the annealing further comprises: maintaining the annealing temperature for a first duration, and rapidly cooling the glass-ceramic article from the annealing temperature to room temperature at a cooling rate substantially greater than a furnace rate.

[0046] A forty-second aspect of the present disclosure includes the method according to aspect forty-first, wherein the first duration is about 12 hours.

[0047] The forty-third aspect of the present disclosure includes a method according to the fortieth aspect, wherein the annealing temperature includes a first annealing temperature and a second annealing temperature greater than the first annealing temperature, wherein the first annealing temperature and the second annealing temperature are outside a threshold temperature so as to substantially maintain the first transmittance, and wherein the annealing further includes: heating the first orifice to the first annealing temperature, heating the body to the second annealing temperature, gradually cooling the body to the first annealing temperature, and rapidly cooling the first orifice and the body from the first annealing temperature to room temperature at a cooling rate substantially greater than a furnace rate.

[0048] A forty-fourth aspect of the present disclosure includes a method according to the forty-third aspect, wherein heating the body to the second annealing temperature includes heating the body using a heater plate, the heater plate defining at least one through hole aligned with the first aperture.

[0049] A forty-fifth aspect of the present disclosure includes the method according to the forty-third aspect, wherein heating the body to the second annealing temperature includes heating the body using a mid-infrared heater.

[0050] A forty-sixth aspect of the present disclosure includes a method according to the forty-fourth aspect or the forty-fifth aspect, wherein during heating the body to the second annealing temperature, the first orifice is actively cooled by one or more of conduction and convection.

[0051] A forty-seventh aspect of the present disclosure includes a method according to any one of aspects forty-first to forty-sixth, wherein after annealing, the first transmittance decreases by less than 5% / mm.

[0052] A forty-eighth aspect of the present disclosure includes a method according to the fortieth aspect, wherein the annealing further includes setting the annealing temperature to a threshold temperature for a period of time so as to reduce the first transmittance.

[0053] A forty-ninth aspect of the present disclosure includes the method according to the fortieth aspect, wherein the annealing further includes setting the annealing temperature to gradually pass through a threshold temperature so as to reduce the first transmittance.

[0054] A fiftieth aspect of the present disclosure includes a method according to aspect 48 or aspect 49, wherein after annealing, the first transmittance decreases by at least 5% / mm.

[0055] A fifty-first aspect of the present disclosure includes a method according to any one of aspects 41 to 50 , wherein the threshold temperature is in a range from greater than about 460° C. to about 500° C.

[0056] A fifty-second aspect of the present disclosure includes a method according to any one of aspects 40 to 51, further comprising ion exchanging the glass-ceramic article in a bath containing sodium nitrate and / or potassium nitrate for 0.25 to 25 hours at a temperature between 360 and 450°C.

[0057] A fifty-third aspect of the present disclosure includes the method according to the fifty-second aspect, wherein a residual birefringence in the first pore after the annealing and before the ion exchanging is less than about 200 nm / mm.

[0058] A fifty-fourth aspect of the present disclosure includes a method according to any one of the first to fifty-third aspects, wherein the first transmittance can be selected between about 1% higher than the bulk transmittance and a transmittance of about 91% / mm at the first wavelength.

[0059] A fifty-fifth aspect of the present disclosure includes a method according to any one of aspects twenty-ninth to fifty-fourth, wherein the second transmittance can be selected between about 1% higher than the bulk transmittance and a transmittance of about 91% / mm at the first wavelength.

[0060] A fifty-sixth aspect of the present disclosure includes a method according to any one of the first to fifty-fifth aspects, wherein at the first wavelength, the bulk transmittance is in a range from about 0.001% / mm to about 1% / mm.

[0061] A fifty-seventh aspect of the present disclosure includes a method according to any one of the first to fifty-sixth aspects, wherein within a ratio band extending 100 nm between wavelengths of about 350 nm to about 2,500 nm, the ratio between the first transmittance and the bulk transmittance is at least 1.0×10 5 .

[0062] A fifty-eighth aspect of the present disclosure includes the method according to the fifty-seventh aspect, wherein the ratio band is centered at a wavelength of 450 nm.

[0063] A fifty-ninth aspect of the present disclosure includes a method according to any one of the first to fifty-sixth aspects, wherein within a ratio band extending 100 nm between wavelengths of about 350 nm to about 2,500 nm, a ratio between the first transmittance and the bulk transmittance is at least 8.0×10 26 .

[0064] A sixtieth aspect of the present disclosure includes the method according to the fifty-ninth aspect, wherein the ratio band is centered at a wavelength of 1340 nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is a schematic perspective view of a glass-ceramic article having a plurality of transparent regions laser bleached into an opaque body of the article;

[0066] Figure 2 yes Figure 1 Schematic side views of glass-ceramic articles with laser-bleached transparent regions having different configurations;

[0067] Figure 3 is an image of a protrusion that may have formed at the transparent area due to laser bleaching;

[0068] Figure 4 is through Figure 3 an image of light projected by the protrusion to illustrate the focusing function of the protrusion;

[0069] Figure 5 Laser bleaching of glass-ceramic products (such as Figure 1 and Figure 2 A flowchart of a method for preparing a product of the invention.

[0070] Figure 6 yes Figure 1 A schematic side view of a glass-ceramic article of , wherein a heat sink portion is disposed on a surface of the glass-ceramic article;

[0071] Figure 7 is a transmittance curve diagram based on preheating temperature in the bleaching region at a wavelength of 633 nm for different samples during laser bleaching according to Example 1;

[0072] Figure 8 is a graph of transmittance of bleached and unbleached regions of the glass-ceramic article according to Example 2 over a range of wavelengths, wherein the residual absorption region is shown to facilitate selection of the laser bleaching wavelength;

[0073] Fig. 9 is a graph of relative transmittance at different wavelengths versus annealing time and a graph of annealing temperature versus annealing time for a glass-ceramic sample according to Example 3, in order to illustrate the threshold temperature;

[0074] Fig.10 is a graph of relative transmittance at different wavelengths versus annealing time and a graph of annealing temperature versus annealing time for a glass-ceramic article according to another annealing cycle according to Example 3 to facilitate illustration of the threshold temperature;

[0075] Fig.11 is a graph of temperature versus annealing time for a glass-ceramic article according to Example 3 to illustrate preferential heating of selected portions of the glass-ceramic article;

[0076] Figures 12A-12D are images and data obtained from an experiment to evaluate the effects of alkali metal cation characteristics in glass-ceramic article samples according to Example 4;

[0077] Fig.13A and Fig. 13B are images and data obtained from another experiment according to Example 4 to evaluate the effect of alkali metal cation characteristics in glass-ceramic article samples;

[0078] Fig.14 are images obtained from experiments to evaluate the effect of laser beam spot size on the quality of the transparent area during laser bleaching;

[0079] Fig.15 is a graph illustrating the effect of laser beam irradiation time and laser beam spot size on the size of the transparent region during laser bleaching;

[0080] Fig.16 is a magnified digital image of a sample with a bleached orifice according to Example 6;

[0081] Fig.17 is a graph of the transmittance of the bleached aperture in the sample according to Example 6 over a range of wavelengths;

[0082] Fig.18 is a graph of the transmittance of the unbleached bulk glass in the sample according to Example 6 over a range of wavelengths;

[0083] Fig.19 According to Example 6 Fig.18 A plot of the transmittance of the bleached pore in the sample; and

[0084] Fig. 20 In the same wavelength range, Fig.19 The transmittance of the bleaching pore and Fig.18 A graph showing the ratio of the transmittance of the main glass in FIG. DETAILED DESCRIPTION

[0085] For the purpose of promoting an understanding of the principles of the present invention, reference is now made to the embodiments shown in the accompanying drawings and described in the following written specification. It should be understood that it is not intended to limit the scope of the present invention thereby. It should be further understood that the present invention includes any changes and modifications to the illustrated embodiments, and includes further applications of the principles disclosed herein, as would normally occur to a person skilled in the art to which the present invention belongs.

[0086] As used herein, when used to list two or more items, the term "and / or" means that any one of the listed items can be used alone, or any combination of two or more of the listed items can be used. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A alone; B alone; C alone; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C.

[0087] In this document, relational terms, such as first and second, top and bottom, and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0088] As used herein, the term "about" indicates that amounts, dimensions, formulations, parameters and other variables and characteristics are not and need not be exact, but may be approximate and / or larger or smaller as desired, reflecting tolerances, conversion factors, rounding and measurement errors, etc., as well as other factors known to those skilled in the art. When the term "about" is used to describe the value or endpoint of a range, it is understood that the present invention includes the specific value or endpoint referred to. Regardless of whether the numerical value or the endpoint of a range in this specification is stated "about", the numerical value or the endpoint of the range is intended to include two embodiments: one modified with "about" and one not modified with "about". It should be further understood that the endpoint values ​​of each range are meaningful when related to another endpoint value and when not related to another endpoint value.

[0089] As used herein, the terms "substantial," "substantially," and variations thereof, unless defined elsewhere in connection with a particular term or phrase, are intended to mean that the feature being described is equal to or approximately equal to a value or description. For example, a "substantially flat" surface is intended to mean a flat or approximately flat surface. Additionally, "substantially" is intended to mean that two values ​​are equal or approximately equal. In some embodiments, "substantially" can mean values ​​that are within about 10% of each other, such as values ​​that are within about 5% of each other, or values ​​that are within about 2% of each other.

[0090] Directional terms used herein, such as up, down, right, left, front, back, top, bottom, above, below, etc., are only used with reference to the drawings and are not intended to represent absolute orientations.

[0091] As used herein, the terms "the," "a," or "an" mean "at least one," and should not be limited to "only one," unless clearly indicated to the contrary. Thus, for example, reference to "a component" includes embodiments having two or more such components unless the context clearly indicates otherwise.

[0092] For purposes of this disclosure, the terms "bulk," "bulk composition," and / or "bulk composition" are intended to include the overall composition of the entire article. These terms may not be distinguished from a "topical composition" or "localized composition" (which refers to a composition at a specific location, region, or volume on or within an article). For example, a topical composition may differ from a bulk composition due to the formation of a crystalline phase and / or a ceramic phase. The bleaching orifices disclosed herein include topical compositions.

[0093] As used herein, the terms "article," "glass-article," "ceramic-article," "glass-ceramic," "glass element," "glass-ceramic article," and "glass-ceramic object" are used interchangeably and in the broadest sense to include any object made entirely or partially of glass and / or glass-ceramic material having a crystalline phase.

[0094] As used herein, "glass" or "glass state" refers to an inorganic amorphous phase material within the articles of the present disclosure, which is a melt product that cools to a rigid state without crystallization. As used herein, "glass-ceramic" or "glass-ceramic state" refers to an inorganic material within the articles of the present disclosure that includes both a glass state and a crystalline phase and / or crystalline precipitate, as described herein.

[0095] As used herein, "crystalline phase" and / or "crystalline precipitate" refers to an inorganic material within the article of the present invention, which is a solid composed of atoms, ions or molecules arranged in a three-dimensional periodic manner. Further, unless otherwise expressly stated, the following methods are used to determine the presence of the "crystalline phase" referred to in the present disclosure. First, powder x-ray diffraction ("XRD") is used to detect the presence of crystalline precipitates. Second, in the case where XRD is unsuccessful (e.g., due to the size, amount and / or chemical nature of the precipitate), Raman spectroscopy ("Raman") is used to detect the presence of crystalline precipitates. Optionally, transmission electron microscopy ("TEM") is used to visually confirm or otherwise confirm the determination of the crystalline precipitate obtained by XRD and / or Raman techniques. In some cases, the amount and / or size of the precipitate may be low enough that visual confirmation of the precipitate proves to be particularly difficult. Therefore, the larger sample size of XRD and Raman may be conducive to sampling a larger amount of material to determine the presence of the precipitate.

[0096] As used herein, "transmission", "transmittance", "optical transmittance" and "total transmittance" are used interchangeably in the present invention and refer to external transmission or transmittance, which takes into account absorption, scattering and reflection. Fresnel reflection is not subtracted from the transmission and transmittance values ​​recorded herein. The transmittance value referred to in a specific wavelength range is the average of the total transmittance values ​​measured in the specified wavelength range. Transmittance (T) is defined as the ratio of the transmitted intensity (I) to the incident intensity (I0), given by the equation T=I / I0. Transmittance takes values ​​between 0 and 1, but is usually expressed as a percentage. Transmittance is measured with a spectrophotometer.

[0097] As used herein, "optical density units", "optical density", "OD" and "OD units" are used interchangeably in the present invention to refer to optical density units, which are generally understood to be a measure of the "absorbance" of a test material measured with a spectrophotometer. The absorbance value stated within a specific wavelength range (e.g., UV wavelengths from 280 nm to 380 nm) is given as the average value of the absorbance within the specified wavelength range. Absorbance (A) is related to transmittance, transmitted intensity and incident intensity according to the formula A = log 10 *I0 / I=-log 10 *T. For example, an absorbance of 0 corresponds to 100% transmittance, while an absorbance of 1 corresponds to 10% transmittance. Unless otherwise specified, transmittance and absorbance were measured using a PerkinElmer Lambda 950 UV-VIS-NIR spectrophotometer, a commercially available spectrophotometer.

[0098] The present invention generally relates to articles having one or more (bleached) or transparent regions formed in a monomeric material that is highly opaque at visible and near infrared (NIR) wavelengths, and methods for forming these regions. Specifically, the high opacity in the present invention is achieved by high absorbance, which is superior to opaque scattering materials. The transparent region in an embodiment may include one or more apertures, louvers or any similar transparent light paths or channels that are configured to allow light to pass through the highly opaque material with a higher transmittance or substantially higher transmittance than transmitting through the highly opaque material. Those skilled in the art will recognize that, without departing from the concepts of the present invention, the transparent regions applied to the article may take a variety of forms. In an embodiment, the highly opaque monomeric material is configured to optically isolate one or more transparent regions with high absorbance with a minimum path length.

[0099] In various embodiments of the present invention, the bleached article can be a glass-ceramic article. The bleached article can be a glass-ceramic containing tungsten, molybdenum, titanium and / or magnesium, such as U.S. Pat. No. 10,246,371, entitled "ARTICLES INCLUDING GLASS AND / OR GLASS-CERAMICS AND METHODS OF MAKING THESAME", U.S. Pat. No. 10,370,291, entitled "ARTICLES INCLUDING GLASS AND / OR GLASS-CERAMICS AND METHODS OF MAKING THESAME", U.S. Pat. No. 10,450,220, entitled "GLASS-CERAMICS AND GLASSES", U.S. Pat. No. 10,450,220, entitled "POLYCHROMATICARTICLES AND METHODS OF MAKING THESAME ...POLYCHROMATICARTICLES AND METHODS OF MAKING THESAME", U.S. Pat. No. 10,450,220, entitled "POLYCHROMATICARTICLES AND METHODS OF MAKING THESAME", U. The present invention relates to those disclosed in U.S. patent application serial number 17 / 183,539 filed on February 24, 2021, entitled “LOW TEMPERATURE LASER BLEACHING OF POLYCHROMATIC GLASS CERAMICS”, the contents of each of which are incorporated herein by reference in their entirety.

[0100] In general, the crystalline phase formed by heat treating the composition of the article described herein (before bleaching) can be referred to as a suboxide. Tungsten bronze is an example of a suboxide because such crystals have a non-stoichiometric ratio of dopant to tungsten ions. The crystal structure present in the glass-ceramic article of the present invention can undergo changes in oxidation state and changes in dopant concentration, which is a result of one or more heating processes applied during the preparation process to achieve various colors and / or color characteristics of the glass-ceramic article. Similarly, the oxidation state and / or dopant concentration of the crystal structure of the present invention can be changed by the bleaching process disclosed herein. Changes in dopant concentration can also affect the absorbance of the composition in the ultraviolet (UV), visible and near infrared (NIR) wavelength ranges. In various examples, the crystal structure changes, stoichiometric changes and / or oxidation state changes caused by the beam from the laser may be accompanied by the redissolution of the crystals, so that the crystals are dissolved in the glass matrix. The properties of the crystal structure of the glass-ceramic article enable the glass-ceramic article of the present invention to be bleached at relatively low temperatures.

[0101] The composition of the glass-ceramic article can be designed for a specific forming process (e.g., melt forming, pressing, casting, etc.), and the glass-ceramic article can then be heat treated to adjust or fine-tune the color and / or saturation or absorbance of the glass-ceramic article to the desired color and / or saturation level. Regardless of the manner or method used in the formation of the glass-ceramic article, the glass-ceramic article can be bleached by the technology disclosed herein. The glass transition temperature T of the glass-ceramic article bleached by the method of the present invention is g However, the glass transition temperatures of the various compositions are each within the range of about 400°C to about 600°C.

[0102] The glass transition temperature is defined as the temperature at which the glass portion of a glass or glass-ceramic has a temperature of 10 12 The "annealing point" or "annealing temperature" is defined herein as the temperature at which the glass portion of a glass or glass-ceramic has a viscosity of 10 13 The "softening point" or "softening temperature" is defined herein as the temperature at which the glass portion of a glass or glass-ceramic has a viscosity of 10 7.6 The temperature at which the viscosity of the glass is 0.1 poise. When the article is cooled uniformly, the glass transition temperature or annealing temperature may be approximately the same throughout the article. However, if one portion of the article is cooled differently than another portion of the article, the glass transition temperature or annealing temperature may be different in the portions having different cooling rates or cooling histories. Local fluctuations in the glass composition may also result in slight variations in the glass transition temperature or annealing temperature.

[0103] The desired color and / or saturation level or absorbance of the glass-ceramic article may have an effect on the final contrast of the bleached area formed in the glass-ceramic article. The method disclosed herein is capable of bleaching the glass-ceramic article so that the bleached area is transparent or substantially transparent within a given wavelength range (e.g., one or more wavelengths of the visible spectrum from about 380nm to 740nm). Therefore, compared with the glass-ceramic article with a lower saturation level, the glass-ceramic article with a higher saturation level can exhibit a higher resulting contrast. Although one or more heating processes can be selectively applied during the manufacturing process to adjust the color and / or saturation level of the glass-ceramic article, the local heating process (e.g., laser bleaching) for bleaching the article disclosed herein can reverse one or more heating processes to remove the color of the bleached area and / or reduce the saturation level. Therefore, the color or other properties of the article can change in the bleached area. Examples of physical and chemical properties that are changed by interacting with a beam from a laser can include, but are not limited to, oxidation state, coordination number, structural phase, mechanical properties (e.g., local density and / or local stress), crystallinity, percent crystallinity and / or thermal properties (e.g., T g , fictive temperature and / or specific heat).

[0104] Reference Figure 1, which describes a glass-ceramic article 10. The article 10 has a thickness, a width, and a length. The thickness extends between the top surface 14 and the bottom surface 18 of the article 10. The width extends between the front surface 22 and the back surface 26 of the article 10. The length extends between the sides 30 and 34 of the article 10. In an embodiment, the article 10 has a width from about 0.100 mm to about 3.750 mm, or from about 0.050 mm to about 4.875 mm, or from about 0.090 mm to about 6.0 mm, or from about 0.050 mm to about 7.125 mm, or from about 0.080 mm to about 8.25 mm, or from about 0.050 mm to about 9.375 mm, or from about 0.070 mm to about 10.5 mm, or from about 0.050 mm to about 11.625 mm, or from about 0.0 The thickness of the substrate 10 can be from about 0.60 mm to about 12.75 mm, or from about 0.050 mm to about 13.875 mm, or from about 0.185 mm to about 15.0 mm, or from about 0.155 mm to about 15.0 mm, or from about 0.125 mm to about 15.0 mm, or from about 0.095 mm to about 15.0 mm, or from about 0.065 mm to about 15.0 mm, or from about 0.050 mm to about 15.0 mm, and all thickness values ​​between the endpoints of these thickness ranges. In addition, the article 10 can have a selected length and width or diameter to determine its surface area. The article 10 can have at least one edge defined by its length and width or diameter between the surfaces 14, 18 of the substrate 10.

[0105] The first bleached region 36 is exemplarily shown in dashed lines and is shown as a cylindrical orifice. The first bleached region 36 can extend through the entire thickness in a direction parallel to the thickness. The first bleached region 36 can have the same or substantially the same resolution throughout its entire range extending through the entire thickness. That is, the resolution of the first bleached region 36 can be the same or substantially the same at a portion of the first bleached region 36 near the top surface 14, at a portion of the first bleached region 36 near the bottom surface 18, and at a portion located between the top surface 14 and the bottom surface 18.

[0106] The second bleached zone 37 is exemplarily shown in dashed lines and is shown as a slit or skylight in the article 10. The second bleached zone 37 can extend through the entire thickness. Similar to the first bleached zone 36, the second bleached zone 37 can have the same or substantially the same resolution throughout the entire range in which the second bleached zone 37 extends through the thickness. Figure 1As shown in , the second bleaching region 37 in an embodiment can be oriented at an angle α relative to the surface between which the bleaching region extends. The angle α in an embodiment can be between 0.1° and arcsin (1 / n) relative to the thickness direction, where n is the refractive index. For n=1.45, arcsin (1 / n)=43.6°. In an embodiment, the article 10 can include a first bleaching region 36, a second bleaching region 37, or both a first bleaching region 36 and a second bleaching region 37. In an embodiment, the article 10 can include any number of other bleaching regions. The first bleaching region 36, the second bleaching region, and any additional bleaching regions can have any desired number, geometry, angle, and / or orientation. In an embodiment, the bleaching regions can be substantially repeated, for example, two first bleaching regions 36, 39 and / or two second bleaching regions 37, 40. There can be a minimum spacing between the bleaching regions. In an embodiment, the minimum spacing can be at least 0.5 mm. In other embodiments, the minimum spacing between the bleaching regions can be 1 mm or more. In some embodiments, the spacing between bleached areas or lines can vary from about 0.5 mm to about 10 mm.

[0107] The first bleached region 36, the second bleached region 37, and / or any number of additional bleached regions may form one or more apertures in or through the article 10. As used herein, an "aperture" refers to an integral portion of an article through which light travels at a higher or substantially higher transmittance than through an unbleached region of the article 10. In embodiments, the aperture cross-section may be non-polygonal (e.g., circular, elliptical, oval, or stadium-shaped), polygonal (e.g., rectangular, square, or triangular), or any suitable geometric shape. In embodiments where the aperture is formed through the thickness of the material defined by the first and second surfaces, as described above, the cross-sectional dimensions of the aperture may be the same throughout the thickness of the material, or may be different throughout the thickness of the material. As a non-limiting example, for an aperture having a circular cross-section, the aperture may be cylindrical and have the same cross-sectional diameter at the first and second surfaces of the material. In embodiments, the cross-sectional dimensions of the aperture are larger at the first surface of the material than at the second surface of the material. For example, the aperture may be conical in shape.

[0108] In embodiments, the orifice may be formed over a portion of the thickness of the glass-ceramic article, rather than through the entire thickness. For example, the orifice may extend through at least 5%, at least 10%, at least 20%, at least 30%, or at least 40%, or at least 45% of the thickness of the glass-ceramic article. In embodiments, the orifice may extend through at most 55%, at most 60%, at most 70%, at most 80%, at most 90%, or at most 95% of the thickness of the glass-ceramic article.

[0109] In the embodiments disclosed herein, the term "diameter" is not limited to circles. Thus, the "diameter" in the embodiments may refer to the distance between the edges of an orifice, which may be square, rectangular, polygonal, or any geometric shape suitable for a particular end use. For an orifice that is a polygon, the diameter refers to a straight line passing through the center of the orifice from one side to the other. In the case of a rectangle, the diameter refers to the smallest cross-sectional dimension of the rectangle. In the case of a triangle, the diameter refers to the smallest height of the triangle. In the case of an elliptical orifice, the diameter refers to the smallest cross-sectional dimension passing through the center of the ellipse.

[0110] In embodiments, the bleaching zone comprises a plurality of pores, wherein each pore has a diameter in the range of about 10 μm to about 100,000 μm, or in the range of about 10 μm to about 10,000 μm, or in the range of about 10 μm to about 5,000 μm, in the range of about 10 μm to about 1,000 μm, or in the range of about 10 μm to about 500 μm, or in the range of about 50 μm to about 10,000 μm, or in the range of about 50 μm to about 5,000 μm, or in the range of about 50 μm to about 50 μm. In an embodiment, the center-to-center spacing of the orifices is in the range of about 20 μm to about 200 μm or about 200 μm. In an embodiment, the center-to-center spacing of the orifices is in the range of about 20 μm to about 200 μm or about 200 μm. In an embodiment, the center-to-center spacing of the orifices is in the range of about 20 μm to about 200 μm or about 20 μm to about 100 μm.

[0111] The first portion 38 of the article 10 is the portion of the article 10 that is bleached due to the interaction between the article 10 and the beam from the laser. The second portion 42 of the article 10 is the area of ​​the article that is not exposed to the beam from the laser. The first portion 38 and the second portion 42 are sometimes referred to herein as the bleached area and the unbleached area, respectively. It should be understood that although the article 10 is Figure 1 1 is depicted as a rectangular substrate, but the invention is not so limited. Rather, the contour of article 10 may be such that one or more of top surface 14, bottom surface 18, front surface 22, back surface 26, side surface 30, and side surface 34 are provided with turning points, undulations, bevels, curvatures, and / or other perturbations such that a given surface may not lie entirely along a single plane.

[0112] Now refer to Figure 2 , describes a glass-ceramic article 10a. In addition to the configuration of the bleached region or the pores formed therein, Figure 2 The glass-ceramic product 10a and Figure 1 Similar to glass-ceramic products. Figure 2 In, with Figure 1 Features of the glass-ceramic article 10a that are substantially similar use the same reference numerals with an "a". The glass-ceramic article 10a includes a first orifice 44, a second orifice 48, a third orifice 52, and a fourth orifice 56 formed in the body 42b. The first orifice 44, the second orifice 48, and the third orifice 52 are formed over a portion of the thickness of the glass-ceramic article 10a, rather than through the entire thickness. For example, the first orifice 44 is formed over approximately 60% of the thickness of the glass-ceramic article 10a, and the second orifice 48 and the third orifice are each formed over approximately 40% of the thickness of the glass-ceramic article 10a.

[0113] When Figure 2 When formed over a portion of the thickness of the glass-ceramic article as shown in , the apertures may be adjacent to only one surface of the glass-ceramic article. For example, first aperture 44 and second aperture 48 are each adjacent to top surface 14a, while third aperture 52 is adjacent to bottom surface 18a. In embodiments, apertures formed over a portion of the thickness and adjacent to different or opposing surfaces may be aligned so as to be co-linear over the entire thickness or to have at least some overlap when viewed in the direction of extension, such as Figure 2 48 and the third orifice 52 shown in . In an embodiment, the second orifice 48 and the third orifice 52 can be formed from different or opposite surfaces, but the respective lengths are sufficient to allow the second orifice 48 and the third orifice 52 to intersect, thereby forming or substantially forming a single orifice. This embodiment including a single hole composed of corresponding hole portions formed from different or opposite sides may be useful when forming a bleached region in a relatively thick glass-ceramic article.

[0114] The aperture in embodiments may include a protrusion or projection at the surface through which it is formed in the glass-ceramic article. Figure 2 The fourth aperture 56a in the glass-ceramic article 10a includes a protrusion 58 protruding from the top surface 14a. During the bleaching process, as discussed later in this disclosure, the glass exposed to the laser can expand as it heats. This expansion can result in the formation of the protrusion 58. Figure 3 is a magnified image of a protrusion 58 protruding from an aperture formed in a glass-ceramic article prepared according to the methods disclosed herein. Protrusion 58 can act as a lens to focus light, which can be useful in various applications, such as a cover for a detector or sensor. Figure 4 is a projection that is transmitted through an aperture formed in a glass-ceramic article (e.g. Figure 2 and Figure 3 The light is projected onto a surface spaced apart from the glass-ceramic article. Figure 4 As shown in , the transmitted light image 60 includes a bright spot 64 in the center of the projected light image, indicating that the protrusion 58 can be used as a focusing optic. By changing the laser parameters, as discussed later in this disclosure, the geometry and / or shape of the protrusion 58 can be changed, thereby changing the numerical aperture of the lens. In embodiments, post-processing the protrusion 58 by grinding / polishing / CNC machining can further change the geometry and / or shape of the protrusion to change its focusing properties.

[0115] In an embodiment, the glass-ceramic article may include a bleached pattern formed by a plurality of orifices. For example, bleached lines and / or other patterns may be formed by bleaching a series of spots or holes that are close to each other or have partial overlap to form a design. This patterning process is similar to a graphic composed of pixels, and is similar to a painting technique called pointillism, in which an image is formed by spots of different colors. In a similar manner, patterning or formation of bleached shapes may be achieved by adjusting the shape of the laser beam. As discussed later in this disclosure, this technique is combined with partial or complete bleaching to enable the formation of images and patterns with varying transmittance levels or shadows. By partially bleaching the bleached areas in the sample so that the transmittance of the bleached areas is slightly higher than that of the unbleached areas, the bleached features or patterns may be effectively hidden until the sample is backlit to display them. This concept is sometimes referred to as "dead-fronting".

[0116] Reference Figure 5 , bleached glass-ceramic products (such as Figure 1 Glass-ceramic products 10 and Figure 2 The method 500 of the glass-ceramic article 10a) may include preheating the glass-ceramic article (block 504). The glass-ceramic article includes a body having an amorphous silicate glass phase, a crystalline phase, and a body transmittance. In an embodiment, the crystalline phase includes M xWO3 material, where 0 < x < 1 and M is an intercalation doping cation, such as one or more of H, Li, Na, K, Rb, Cs, Ca, Sr, Ba, Zn, Ag, Au, Cu, Sn, Cd, In, Tl, Pb, Bi, Th, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, U, Ti, V, Cr, Mn, Fe, Ni, Pd, Se, Ta, and / or Ce. In an embodiment, preheating can be carried out before other steps of method 500. It has been found that the temperature maintained by the glass-ceramic article during the bleaching process can affect the final transmittance achieved by bleaching, as shown in Example 1 discussed after this disclosure. In an embodiment, preheating includes heating the glass-ceramic article to a preheating temperature in the range of about 100 °C to about 600 °C, or about 200 °C to about 575 °C, or about 300 °C to about 500 °C, and also includes all sub-ranges and sub-values between the endpoints of these ranges.

[0117] Method 500 further includes irradiating a first portion of the body by directing a beam from a laser to reach the thickness of the glass-ceramic article body to heat the first portion in the body and form a first orifice, as Figure 1 the first bleaching region 36 and / or the second bleaching region 37 (block 508). After irradiation, the first orifice has a first transmittance at a first wavelength within a given range (such as from about 350 nm to about 2500 nm, or other ranges discussed after this disclosure), which is greater than or higher than the body transmittance. In an embodiment, at the first wavelength, the body transmittance is in the range of about 0.001% / mm to about 1% / mm, but other ranges discussed after this disclosure can also be considered. In an embodiment, the beam includes a bleaching wavelength selected from the laser band, and after irradiation at the bleaching wavelength in this band, residual absorption persists in the orifice.

[0118] As used herein, the term "residual absorption" refers to the absorption ability retained in the orifice within one or more laser bands after irradiation at the bleaching wavelength. The persistence of this post-irradiation residual absorption ensures sufficient absorption during irradiation to heat the irradiated portion to a sufficient temperature (hereinafter interchangeably referred to as the dissolution temperature) to cause the composition of the crystalline phase (e.g., M xWO3 substances) are significantly, substantially and / or completely dissolved in the bulk. In embodiments, in terms of transmittance, after irradiation, the residual absorption is from about 5% / mm to about 85% / mm (or an absorbance in the range of from about 1.3 / mm to about 0.071 / mm), or from about 10% / mm to about 85% / mm (or an absorbance in the range of from about 1.0 / mm to about 0.071 / mm), or from about 10% / mm to about 80% / mm (or an absorbance in the range of from about 1.0 / mm to about 0.097 / mm), or from about 10% / mm to about 70% / mm (or an absorbance in the range of from about 1.0 / mm to about 0.155 / mm). / mm), or from about 15% / mm to about 75% / mm (or absorbance in the range of from about 0.824 / mm to about 0.125 / mm), or from about 5% / mm to about 70% / mm (or absorbance in the range of from about 1.3 / mm to about 0.155 / mm), or from about 5% / mm to about 60% / mm (or absorbance in the range of from about 1.3 / mm to about 0.222 / mm) persists in the aperture, and also includes all sub-ranges and sub-values ​​between the endpoints of these ranges within one or more laser bands.

[0119] In an embodiment, the laser band from which the bleaching wavelength is selected includes at least two laser bands spaced apart such that the at least two laser bands do not overlap. In an embodiment, the at least two laser bands are spaced apart at opposite ends of the first wavelength range. For example, one of the at least two laser bands includes a lower laser band that is less than the first wavelength, and the other of the at least two laser bands includes an upper laser band that is greater than the first wavelength. In an embodiment, the lower laser band is adjacent to and / or overlaps with a lower end of the first wavelength. In an embodiment, the higher laser band is adjacent to and / or overlaps with an upper end of the first wavelength. In conjunction with Example 2 discussed later in this disclosure, the determination of the laser band in which residual absorption persists in the aperture after irradiation at the bleaching wavelength is described.

[0120] The bleaching wavelength is configured to couple into the absorption or absorption band of different absorbing species within the glass-ceramic article body to heat the irradiated portion of the body to the dissolution temperature. x The WO3 species corresponds to a primary absorbing species into which the bleaching wavelength is coupled during irradiation. In an embodiment, the body includes a secondary absorbing species into which the bleaching wavelength is coupled during irradiation. The secondary absorbing species is different from the primary absorbing species so as to provide residual absorption. In an embodiment, the secondary absorbing species includes a chemical hydroxyl group (i.e., OH group) in the body that can absorb in the infrared (IR) spectral region. In an embodiment, the secondary absorbing species includes an ultraviolet (UV) absorption edge of an amorphous silicate glass phase in the body, which can absorb in the UV spectral region.

[0121] In an embodiment, the secondary absorbing species comprises a dopant configured to absorb at the bleaching wavelength during irradiation. In such embodiments, method 500 further comprises doping the body with the dopant prior to irradiation. In an embodiment, the dopant comprises one or more of Ce, Er, Tb, Pr, Mn, Ti, Cu, Co, Ni, Fe, Cr, V, Ag, and Au in oxide or metallic form. In an embodiment, the body comprises less than 2.5 mol% of a dopant selected from the group consisting of Ce, Er, Pr, Tb, and combinations thereof (i.e., rare earth dopants). In an embodiment, the body comprises less than 0.5 mol% of a dopant selected from the group consisting of Mn, Ti, Cu, Co, Ni, Fe, Cr, V, Ag, Au, and combinations thereof. In an embodiment, the secondary absorbing species may comprise other absorbing species, including transient absorbing species.

[0122] According to an embodiment, the glass-ceramic article is processed by optically bleaching at least one discrete region in the article. Laser bleaching of the glass-ceramic article may occur due to a variety of mechanisms or processes.

[0123] In an absorptive glass-ceramic material such as the glass-ceramic compositions disclosed herein, the oxidation state of an ion (e.g., a metal ion or an ion complex, such as a tungstate or molybdate) can be changed by laser bleaching. The ion can absorb the laser energy directly and change the oxidation state, or it can undergo a change in oxidation state by absorption by another component of the glass-ceramic and interaction with the absorbing component (e.g., thermally or by electron transfer). For example, laser bleaching can cause a redox reaction in which an absorptive ion (e.g., a metal ion) is oxidized or reduced from an absorptive ion or a colored ion to a colorless or less colored ion within a specific wavelength spectrum (e.g., the visible spectrum). In various examples, a beam from a laser can be absorbed by a second absorbing species within the glass-ceramic article (e.g., a chemical hydroxyl group, a UV absorption edge of a glass phase, and / or one or more dopants having absorption at the laser wavelength), which in turn results in a thermal event that causes or initiates a redox reaction between tungsten and / or other multivalent species in the glass-ceramic article, which can contribute and / or accept electrons from other components (e.g., SnO2) present in the glass-ceramic article. It is worth noting that the M x Some crystals of the WO3 type may absorb at the wavelength of the laser beam. In this case, M xThe WO3 crystals may absorb energy from the laser beam, heat up due to the energy absorption, and cause the crystals to decompose, resulting in alkali delamination of the crystals and dissolution of alkali into the glass. In some instances, due to the interaction of the laser beam with the glass-ceramic article, the glass-ceramic article may experience an electron capture effect, wherein electron capture of or electron transfer from an absorbing ion results in a change in oxidation state, which increases the optical transmittance of the area exposed to the laser beam over a given wavelength range.

[0124] In an absorbent glass-ceramic material comprising at least one cation in the crystalline phase, bleaching can occur through a cation delamination process. During the cation delamination process, cations can be released from the crystals of the glass-ceramic article, thereby leaving behind oxidized metal oxides (e.g., tungsten oxide) in the bleached areas of the glass-ceramic article. In embodiments, the delamination cations can also undergo a change in oxidation state.

[0125] In an absorptive glass-ceramic material, upon exposure to a beam from a laser, crystals within the path of the laser beam in the glass-ceramic article may be removed so that components of the crystals dissolve back into the glass, resulting in dissolution of the crystals, which may be referred to as amorphization or vitrification.

[0126] Absorbent glass-ceramic materials can be bleached by exposing the glass-ceramic material to thermal energy. For example, laser bleaching disclosed herein can provide thermal energy for forming bleached regions in the glass-ceramic material. It is possible to achieve laser-induced bleaching by locally heating the bulk to a dissolution temperature, wherein the M of the crystalline phase x The WO3 species is significantly, substantially and / or completely dissolved into the bulk. In an embodiment, the dissolution temperature is above M x The liquidus temperature of the WO3 substance. In an embodiment, the dissolution temperature is in the range of about 600°C to about 1,100°C, or about 900°C to about 1,100°C, or about 650°C to about 1,050°C, or about 700°C to about 1,000°C, or about 800°C to about 1,150°C, and also includes all sub-ranges and sub-values ​​between the endpoints of these ranges. Heating the body to the dissolution temperature causes the irradiated / heated portion of the body to become transparent and / or have a higher and / or substantially higher transmittance than the body. Such heating to the dissolution temperature can eliminate or re-melt crystals within the path of the laser beam, thereby returning the crystalline components to the body.

[0127] It has been observed that if the glass-ceramic article is exposed to a tungsten bronze crystal (e.g., a crystalline phase of M xWO3 species) absorbs the laser wavelength, the resulting heating causes the alkali metal cations to delaminate from the crystal and return to the glass matrix, leaving only the stoichiometric tungsten oxide phase. Since this phase does not strongly absorb visible or near-infrared wavelengths, the temperature of the article decreases even with extended laser exposure. During cooling, some of the alkali leaves the glass and returns to the crystal, resulting in another improvement in absorbance and a decrease in transmittance. In order to completely dissolve the crystal back into the glass, the heating is configured to reach a temperature above the liquidus temperature of the crystal (e.g., the dissolution temperature) within an appropriate time. Therefore, in order to achieve substantial and / or complete dissolution of the crystal using laser exposure, the laser wavelength should be attenuated by the secondary absorbing species within the glass so that the glass continues to heat during laser exposure.

[0128] In absorptive glass-ceramic materials, bleaching may also occur when the glass-ceramic is converted to glass by rapid heating and cooling, including when the temperature of the area or portion exposed to the laser beam is below the dissolution temperature. Rapid heating and cooling can be achieved by exposing the glass-ceramic to a beam from a laser for a period of time that is long enough to convert the glass-ceramic to glass, but short enough to maintain the local temperature of the heated spot for a temperature below the dissolution temperature. For example, localized heating to a local temperature by one or more laser irradiation sources can be used to dissolve or redissolve (e.g., by remelting) various small crystalline phases (e.g., crystallites, micrometer-sized crystals (having a cross-sectional dimension of 10 μm or less), or nanometer-sized crystals (having a cross-sectional dimension of 100 nm or less)) in discrete localized areas of the glass or glass-ceramic substrate exposed to the laser beam.

[0129] Although the present invention is not limited by scientific principles or theories, in embodiments, local heating of discrete areas of a substrate to a local temperature that exceeds the global temperature results in a reversible redox reaction within the glass or glass-ceramic material that erases (e.g., dissociates, decomposes, dissolves, or otherwise eliminates) chromophores in the form of small crystals, thereby producing visible light absorption. As used herein, the term "global temperature" is intended to refer to the bulk or average temperature of a glass-ceramic article, as measured at a location on the glass-ceramic article away from an area actively bleached by a beam from a laser. When the chromophore is erased, the absorbance in the substrate decreases, and the average external transmittance increases. In embodiments, the heating or cooling rate can be changed by changing the power or focus of a continuous wave (CW) laser or by changing the time the glass-ceramic article is exposed to the laser beam.

[0130] Bleaching can be accomplished using any suitable apparatus or system to increase the average external light transmittance in discrete regions. In an embodiment, bleaching is accomplished by heat treating the discrete regions. Such heat treatment can be performed using energy sources known in the art, such as, but not limited to, furnaces, flames (such as gas flames), resistance furnaces, lasers, microwaves, and the like. Laser bleaching has been determined to provide discrete regions of the substrate with increased average external light transmittance after bleaching, and can provide higher resolution of the bleached regions.

[0131] Referring again to aspects of the method 500 for bleaching a glass-ceramic article, a plurality of laser parameters may be used to direct a laser beam into a first portion of a body. In an embodiment, directing a beam from a laser includes directing a focused beam within the thickness of the body to form a first aperture therein. It is contemplated that the glass-ceramic article may have standardized dimensions so that the beam from the laser may be focused in a calibration step before the method 500 begins. In an embodiment, directing a beam from a laser may include directing a defocused beam through the thickness of the body to form a first aperture therein. In such embodiments, the focus of the beam may be in front of or behind the body so that the defocused portion of the beam passes through the thickness of the body. In an embodiment, directing a beam from a laser may include directing a collimated beam through the thickness of the body to form an aperture therein. It is understood that any one or more of a focused beam, a defocused beam, a collimated beam, and other beam configurations may be directed into the thickness of the body to form an aperture therein.

[0132] Although higher transmittance in the first orifice can be achieved by heating the first portion of the body to a dissolution temperature so that the crystal is substantially and / or completely dissolved by the laser beam, it has been observed that heating the first portion of the body above or substantially above the dissolution temperature can lead to defects within the first orifice, such as microbubbles. In an embodiment, to mitigate the formation of such defects, directing the beam from the laser includes adjusting the focus of the beam so that the maximum temperature within the first portion of the body is not exceeded during the irradiation process. In an embodiment, adjusting the focus of the beam includes defocusing the beam so as not to exceed the maximum temperature. In an embodiment, the maximum temperature is the dissolution temperature, or, if the dissolution temperature is a range, the maximum temperature is the maximum endpoint value of the dissolution temperature range. In an embodiment, the maximum temperature is 1,100°C, or 1,125°C, or 1,150°C, or 1,175°C, or 1,200°C, or 1,250°C, or 1,300°C, or 1,500°C, or 1,600°C.

[0133] In an embodiment, directing the beam from the laser includes translating or moving at least one of the glass-ceramic article and the laser or laser beam to form the first aperture. The translation or movement may include vertical translation, horizontal translation, or a combination thereof to change the position of the beam relative to the glass-ceramic article.

[0134] In an embodiment, the laser parameters further include one or more of laser power, beam spot size, and beam exposure time. In an exemplary embodiment, the laser is a mid-infrared laser configured to emit a beam with a wavelength in the range of about 2.6 μm to 2.75 μm. A Cr:ZnSe / S mid-infrared laser from IPG Photonics can be used for the method disclosed herein. In an exemplary embodiment, the laser parameters are configured to form a first orifice with a target diameter in the range of about 2 mm to about 3 mm. In an exemplary embodiment, the laser power is in the range of about 12.5 W to about 45.0 W, or about 15.0 W to about 42.0 W, or about 17.5 W to about 39.0 W, or about 20.0 W to about 36.0 W, or about 22.5 W to about 33.0 W, or about 25.0 W to about 30.0 W, and also includes all sub-ranges and sub-values ​​between these range endpoints.

[0135] In an exemplary embodiment, the beam spot size is in the range of from about 0.20 mm to about 1.50 mm, or from about 0.24 mm to about 1.40 mm, or from about 0.28 mm to about 1.30 mm, or from about 0.32 mm to about 1.20 mm, or from about 0.36 mm to about 1.10 mm, or from about 0.40 mm to about 1.00 mm, or from about 0.44 mm to about 0.90 mm, or from about 0.48 mm to about 0.80 mm, and also includes all sub-ranges and sub-values ​​between these range endpoints. In an exemplary embodiment, the beam irradiation time is in a range from about 0.70 s to about 12.0 s, or from about 0.84 s to about 11.2 s, or from about 0.98 s to about 10.4 s, or from about 1.12 s to about 9.6 s, or from about 1.26 s to about 8.8 s, or from about 1.4 s to about 8.0 s, or from about 1.54 s to about 7.2 s, or from about 1.68 s to about 6.4 s, and also includes all sub-ranges and sub-values ​​between these range endpoints.

[0136] Refer again Figure 2, method 500 includes determining whether to form additional orifices in the glass-ceramic article, such as a repetition of the first bleached region 36 (e.g., a repetition of the first bleached region 39) and / or a repetition of the second bleached region 37 (e.g., a repetition of the second bleached region 40) (box 512). If additional orifices are to be formed, irradiating also includes irradiating a second portion of the body by directing a beam from a laser into the thickness of the body to heat the second portion and form a second orifice therein (box 508, repeated). After irradiating the second portion of the body, the second orifice has a second transmittance at the first wavelength or other range that is greater than or higher than the body transmittance. In embodiments where the second orifice is configured to be substantially a replica of the first orifice, the second transmittance substantially corresponds to and / or is equal to the first transmittance. In other embodiments, the second orifice may differ from the first orifice in any property of the first orifice. For example, the second aperture may differ from the first aperture in terms of transmittance, diameter, and / or any property related to size, cross-sectional shape, extent formed through the thickness (e.g., completely or partially through the thickness), angle extending relative to the thickness, etc.

[0137] In an embodiment, irradiating a first portion of the body to form a first orifice and irradiating a second portion of the body to form a second orifice are performed sequentially with a dwell time in between. The dwell time may be configured to improve stress distribution and reduce variation between the first orifice and the second orifice, and if desired, any further orifices. The dwell time in an embodiment may be configured to be a relatively long dwell time to allow the body to recover to a preheat temperature before irradiating the next portion of the body to form the next orifice. For example, after irradiating the first portion of the body to form the first orifice, the method 500 may include a dwell time of at least 10s, or at least 15s, or at least 20s, or at least 30s, or at least 40s, or at least 60s, or any longer dwell time before irradiating the second portion of the body to form the second orifice. In an embodiment, the dwell time may be configured to be a relatively short dwell time, for example, less than 5s. In an embodiment, the dwell time may be substantially zero, so that the second portion of the body is irradiated immediately after forming the first orifice to form the second orifice.

[0138] In an embodiment, irradiating a first portion of the body to form a first aperture and irradiating a second portion of the body to form a second aperture are performed substantially simultaneously. In such embodiments, the beam from the laser includes at least two beam portions, wherein the first beam portion and the second beam portion are configured to irradiate the first portion of the body and the second portion of the body, respectively. In an embodiment, the beam from the laser includes a plurality of beam portions, the number of which corresponds to the number of apertures to be formed substantially simultaneously in the body. The beam from the laser can be configured to be split or otherwise distributed to form a plurality of beam portions. Additionally, or alternatively, multiple beams from multiple lasers can be used to form some or all of the apertures to be formed substantially simultaneously.

[0139] Reference Figure 6 In an embodiment, method 500 may include contacting a first heat sink portion 304 to a first surface 14 of a body 42 of a glass-ceramic article 10, the first surface 14 being configured to be illuminated by a beam from a laser. The first heat sink portion 304 is configured to define a corresponding first through hole 306 through which the beam from the laser is directed or passed to form a first aperture 36, a second aperture 37, and / or any additional apertures (e.g., a repeating second aperture 40) in the body. In an embodiment, method 500 may further include contacting a second heat sink portion 308 to a second surface 18 of the body 42 opposite the first surface 14, such that the first heat sink portion 304 and the second heat sink portion 308 surround or sandwich the body 42 therebetween. In an embodiment, the second heat sink portion 308 is configured to define a corresponding second through hole 310 through which the beam from the laser is directed or passed to form the first aperture 36, the second aperture 37, and / or any additional apertures in the body. The first through hole 306 and the second through hole 310 may have the same size and / or different sizes as the corresponding adjacent apertures formed by the beam being directed and / or passing therethrough. The first heat sink portion 304 and / or the second heat sink portion 308 are configured to make the temperature substantially uniform across the glass-ceramic article during irradiation. Such temperature uniformity may be beneficial for improving stress distribution and reducing variation between the first aperture and the second aperture, and, if desired, any further apertures. In an embodiment, the first heat sink portion 304 and / or the second heat sink portion 308 may have a gap with the corresponding surface 14, 18 of the glass-ceramic article, for example, in the range of about 100 μm to 1,000 μm. The heat sink portions 304, 308 spaced apart from the surfaces 14, 18 of the glass-ceramic article enable the temperature of the glass to be closer to the set point of the stage temperature and do not reduce the local temperature of the glass directly exposed to the laser during the bleaching process.

[0140] It has been observed that laser bleaching of the glass-ceramic articles described herein can cause the glass exposed to the laser beam to expand due to heating, which in turn causes expansion of the glass-ceramic article material. In addition, the rapid cooling that may occur after bleaching can cause the virtual temperature of the bleached area to be higher than the surrounding unbleached material, which may cause complex stresses in the article. To alleviate these stresses, an annealing step is preferred. With a deeper understanding of the crystallization and light absorption enhancement in the glass-ceramic articles disclosed herein, it is possible to develop favorable annealing cycles that provide better optical transparency of the bleached area. Favorable annealing cycles also enable controlled regulation or reduction of the optical transparency of the bleached area and / or complete reversal of laser bleaching.

[0141] Refer again Figure 5 Once it is determined that no additional apertures are to be formed (block 512), method 500 further includes determining whether to reduce the transmittance of one or more apertures formed in the previous step (block 516). If the transmittance of one or more apertures in the glass-ceramic article is not to be reduced, method 500 further includes annealing the glass-ceramic article by heating the glass-ceramic article to an annealing temperature outside the threshold temperature to substantially maintain the first transmittance (block 520). As used herein, the term "threshold temperature" refers to a temperature range at which partial reduction of crystals (e.g., stoichiometric tungsten oxide) formed during a ceramic cycle occurs during cooling, and subsequent insertion of alkaline cations into these crystals occurs. Determination of the threshold temperature is illustrated in Example 3 discussed later in conjunction with the present disclosure. In an embodiment, the threshold temperature is in a range from greater than about 460°C to about 500°C, or from about 450°C to about 510°C, or from about 440°C to about 520°C, or from greater than 460°C to about 550°C, or from about 430°C to about 575°C, and also includes all subranges and subvalues ​​between these range endpoints.

[0142] When annealing at an annealing temperature other than the threshold temperature, the glass-ceramic article can undergo different annealing cycles. An evaluation of different annealing cycles is described in conjunction with Example 3 discussed later in this disclosure. Annealing according to an example annealing cycle includes maintaining the annealing temperature for a first duration, such as about 12 hours, and then rapidly cooling the glass-ceramic article from the annealing temperature to room temperature, such as at a cooling rate in the range of from about 50° C. per second to about 100° C. per second, which is substantially greater than the furnace rate.

[0143] In an embodiment, the annealing temperature may include a first annealing temperature and a second annealing temperature greater than the first annealing temperature. Annealing according to another example annealing cycle includes heating the first orifice to the first annealing temperature, heating the body to the second annealing temperature, gradually cooling the body to the first annealing temperature, and rapidly cooling the first orifice and the body from the first annealing temperature to room temperature at a cooling rate substantially greater than the furnace rate. In an embodiment, heating the body to the second annealing temperature may include heating the body using a heater plate. The heater plate may be configured to define at least one through hole aligned with the first orifice. In an embodiment, heating the body to the second annealing temperature may include heating the body using a mid-infrared heater. In an embodiment in which the first orifice and the body are heated to different temperatures during annealing, the first orifice may be actively cooled by one or more of conduction and convection during heating the body to the second annealing temperature.

[0144] In embodiments where the annealing temperature is outside the threshold temperature, the first transmittance decreases after annealing by less than 2% / mm, less than 3% / mm, less than 4% / mm, less than 5% / mm, less than 6% / mm, less than 7% / mm, less than 8% / mm, less than 9% / mm, or less than 10% / mm.

[0145] Refer again Figure 5 If the transmittance of one or more apertures in the glass-ceramic article is to be reduced, the method 500 further includes annealing the glass-ceramic article by heating the glass-ceramic article to an annealing temperature within or past the threshold temperature to reduce the first transmittance (block 524). In one example where the annealing cycle is configured to reduce the first transmittance, annealing includes setting the annealing temperature to the threshold temperature for a period of time to reduce the first transmittance. In another example where the annealing cycle is configured to reduce the first transmittance, annealing includes setting the annealing temperature to gradually pass the threshold temperature to reduce the first transmittance.

[0146] In embodiments where the annealing temperature is within or passes the threshold temperature, the first transmittance is reduced by at least 5% / mm, at least 10% / mm, at least 15% / mm, at least 20% / mm, at least 25% / mm, or at least 30% / mm, and / or no more than about 40% / mm, no more than about 50% / mm, no more than about 60% / mm, no more than about 70% / mm, or no more than about 80% / mm.

[0147] In an embodiment, annealing is performed during irradiation, after irradiation, or partly during irradiation and partly after irradiation.

[0148] In an embodiment, by irradiation and annealing, the first transmittance of the first aperture can be selected between about 1% above the bulk transmittance and about 91% / mm transmittance at the first wavelength. In one example, the irradiation is configured to form the first aperture with the selected first transmittance, and the annealing is configured to substantially maintain the selected first transmittance. In another example, the irradiation is configured to form the first aperture with an intermediate transmittance higher than the first transmittance, and the annealing is configured to reduce the intermediate transmittance to the selected first transmittance. As described herein, the second transmittance of the second aperture can be selected in the same manner as the first transmittance.

[0149] After annealing, the glass-ceramic article may be subjected to a finishing step to remove the protrusions 58 ( Figure 2 and Figure 3 ) ) if present, and improve surface quality.

[0150] After annealing, the bleached article can then be chemically strengthened by ion exchange. The bleached article can be ion exchanged in a molten salt bath containing a mixture of lithium nitrate, sodium nitrate, and potassium nitrate at a temperature between 360 and 450°C for 0.25 to 25 hours. In an embodiment, the ion exchange bath is substantially free of lithium nitrate. In an embodiment, the ion exchange bath may also contain silicic acid, sodium nitrite, potassium nitrite, silver nitrate, or a mixture thereof. For example, after bleaching, the part can be immersed in a salt bath containing 80 wt% potassium nitrate, 19.9% ​​sodium nitrate, and 0.1% silicic acid at a temperature of 390°C for 8 hours to strengthen the part and improve its scratch resistance.

[0151] Table 1 below lists non-limiting compositions of glass-ceramic materials that can be bleached and provide optical stability according to the principles of the present invention. Specifically, Table 1 lists various mixed molybdenum-tungsten glass-ceramic compositions (Samples 1-35), each of which contains a combination of WO3 and MoO3, as well as other ingredients, expressed in mol%. According to embodiments of the present invention, these compositions include specific dopant levels and ratios to achieve adjustable local transmittance contrast. These compositions are bleachable and provide optical stability (i.e., maintain transmittance) after thermal treatment (such as annealing and / or chemical strengthening by ion exchange).

[0152] Table 1

[0153]

[0154]

[0155]

[0156] * Combination of sodium nitrate and sodium carbonate

[0157] Prior to bleaching, the bleachable, high contrast glass-ceramic compositions disclosed in Table 1 achieve high absorbance (e.g., high OD≈5 or greater at a thickness of 1 mm) in the ultraviolet (UV), visible (VIS), and near infrared (NIR) wavelength regimes, and simultaneously remain transparent after bleaching and during annealing under appropriate conditions, as described throughout the present disclosure.

[0158] The bleachable, high contrast glass-ceramic compositions disclosed in Table 1 enable the manufacture of glass-ceramic articles having one or more highly transparent regions or "apertures" in a monolithic substrate or "bulk" that is bleached to be highly opaque at visible and near infrared (NIR) wavelengths. In embodiments, the bleached regions or apertures may have a transmittance of at least 60% / mm at wavelengths from 500 nm to 1,100 nm, or at wavelengths from 450 nm to 1,500 nm, or at wavelengths from 450 nm to 1,750 nm, or at wavelengths from 400 nm to 1,900 nm, or at wavelengths from 350 nm to 2,500 nm (i.e., across the entire visible and NIR spectral range). In an embodiment, the bleached region may have a transmittance of at least 70% / mm at a wavelength from 500nm to 1,100nm, or at a wavelength from 450nm to 1,500nm, or at a wavelength from 450nm to 1,750nm, or at a wavelength from 400nm to 1,900nm, or at a wavelength from 400nm to 2,400nm, or at a wavelength from 350nm to 2,500nm. In an embodiment, the bleached region may have a transmittance of at least 80% / mm at a wavelength from 500nm to 1,100nm, or at a wavelength from 450nm to 1,500nm, or at a wavelength from 450nm to 1,750nm, or at a wavelength from 425nm to 1,900nm, or at a wavelength from 425nm to 2,400nm, or at a wavelength from 350nm to 2,500nm. In embodiments, the bleached region may have a transmittance of at least 85% / mm at a wavelength from 500nm to 1,100nm, or at a wavelength from 450nm to 1,500nm, or at a wavelength from 450nm to 1,750nm, or at a wavelength from 450nm to 1,900nm, or at a wavelength from 450nm to 2,400nm, or at a wavelength from 350nm to 2,500nm. In embodiments, the bleached region may have a transmittance of at least 90% / mm (or even at least 91% / mm) at a wavelength from 600nm to 1,100nm, or at a wavelength from 600nm to 1,500nm, or at a wavelength from 600nm to 1,900nm, or at a wavelength from 600nm to 2,400nm, or at a wavelength from 350nm to 2,500nm. In embodiments, the bleached region may have a transmission of at least 85% / mm over a band at least 100 nm wide at any wavelength between 350 nm and 2,500 nm.

[0159] In embodiments, the non-bleached region may have a transmittance of at most 0.1% (or an absorbance of at least 3) at a wavelength from 500 nm to 1,100 nm, or at a wavelength from 450 nm to 1,500 nm, or at a wavelength from 450 nm to 1,750 nm, or at a wavelength from 400 nm to 1,900 nm, or at a wavelength from 350 nm to 2,500 nm (i.e., across the entire visible and NIR spectral range). In embodiments, the non-bleached region may have a transmittance of at most 0.01% (or an absorbance of at least 4) at a wavelength of from 500 nm to 1,100 nm, or at a wavelength of from 450 nm to 1,500 nm, or at a wavelength of from 450 nm to 1,750 nm, or at a wavelength of from 400 nm to 1,900 nm, or at a wavelength of from 400 nm to 2,400 nm, or at a wavelength of from 350 nm to 2,500 nm. In embodiments, the non-bleached region may have a transmittance of at most 0.005% (or an absorbance of at least 4.3) at a wavelength of from 500 nm to 1,100 nm, or at a wavelength of from 450 nm to 1,500 nm, or at a wavelength of from 450 nm to 1,750 nm, or at a wavelength of from 400 nm to 1,900 nm, or at a wavelength of from 400 nm to 2,400 nm, or at a wavelength of from 350 nm to 2,500 nm. In embodiments, the non-bleached region may have a transmittance of at most 0.001% (or an absorbance of at least 5) at a wavelength from 500 nm to 1,100 nm, or at a wavelength from 450 nm to 1,500 nm, or at a wavelength from 450 nm to 1,750 nm, or at a wavelength from 425 nm to 1,900 nm, or at a wavelength from 425 nm to 2,400 nm, or at a wavelength from 350 nm to 2,500 nm. In embodiments, the non-bleached region may have a transmittance of at most 0.001% / mm over a band at least 100 nm wide at any wavelength between 350 nm and 2,500 nm.

[0160] In an exemplary embodiment, the glass-ceramic composition comprises: about 60 mol% to about 70 mol% SiO2; about 8 mol% to about 13 mol% Al2O3; about 7 mol% to about 13 mol% B2O3; about 6 mol% to about 13 mol% R2O, wherein R2O is one or more of Li2O, Na2O, K2O, Rb2O, Cs2O; about 0 mol% to about 0.5 mol% CaO; about 0.01 mol% to about 1 mol% SnO2; about 2 mol% to about 9 mol% WO3; and about 0 mol% to about 2 mol% MoO3. In this embodiment, the amount of R2O minus the amount of Al2O3 is in the range of about -1 mol% to about 1 mol%. The glass-ceramic composition can include lower amounts of R2O (e.g., from about 4 mol% to about 13 mol%) and / or different forms of tin oxide (e.g., tin (II) oxide or tin (IV) oxide) and molybdenum oxide (e.g., molybdenum (IV) oxide or molybdenum (VI) oxide) and still achieve the optical properties described herein.

[0161] In another embodiment, the glass-ceramic composition comprises: about 62 mol% to about 64 mol% SiO2; about 9 mol% to about 12 mol% Al2O3; about 8.5 mol% to about 11.5 mol% B2O3; about 8 mol% to about 12 mol% R2O, wherein R2O is one or more of Li2O, Na2O, K2O, Rb2O, Cs2O; about 0.01 mol% to about 0.4 mol% CaO; about 0.05 mol% to about 0.5 mol% SnO2; about 4 mol% to about 8 mol% WO3; and about 0.05 mol% to about 2.5 mol% MoO3. In this embodiment, the amount of R2O minus the amount of Al2O3 is in the range of about -0.75 mol% to about 0 mol%.

[0162] The high contrast glass-ceramic compositions disclosed in Table 1 differ in that some compositions have lower oxide concentrations of tin, calcium, tungsten, molybdenum, and alkali metals. In addition, the R2O-Al2O3 values ​​of these compositions are less than 0, and as low as -0.49 mol%. Without being bound by theory, negative R2O-Al2O3 values ​​reduce the amount of alkali metal available for embedding in tungsten crystals. The lower concentration of calcium reduces the concentration of nucleation phases present in the glass-ceramic (where the nucleation phase is considered to be calcium tungstate). The lower concentration of tin reduces the electron source provided to the tungsten oxide crystals to partially reduce them. The lower concentrations of tungsten and molybdenum reduce the concentration of crystals present. The lower excess alkali metal (i.e., R2O-Al2O3) controls the stoichiometric range of alkali metal tungsten bronze crystals that can be produced, and their formation rate. In addition, there is evidence that the improved optical stability may be affected by the identity of the alkali metal cation, where the diffusion and intercalation rates decrease with increasing alkali metal cation radius (where Li is the fastest, followed by Na, K, and then Cs). Thus, by further reducing and / or eliminating Li (e.g., samples 28-30 in Table 1), further improved optical stability can be achieved, as evaluated in conjunction with Example 4 discussed later in this disclosure. The level at which the glass-ceramic composition includes dopant cations M other than alkali metal cations can be tailored to the desired transmittance regime. For example, limiting M to only alkali metal cations (e.g., Li, Na, K, Rb, Cs) can achieve the highest transmittance in the bleached state. If M is primarily alkali metals and other species (e.g., Sn), the glass-ceramic composition can produce strong absorbance in the unbleached state and some transmittance (e.g., >50% / mm) in the bleached state.

[0163] The high contrast glass-ceramic compositions disclosed in Table 1 are easily bleached by standard bleaching techniques. In other words, their strong absorbance is eliminated by laser bleaching, resulting in a highly transparent region with an average visible and NIR transmittance greater than 85%. However, it was found that when bleached samples formed from these compositions were subsequently subjected to subsequent thermal treatments such as annealing steps and / or ion exchange steps, their average transmittance decreased to a level less than 85% (i.e., the samples darkened). The laser bleaching technique disclosed herein was developed to prevent the high contrast glass-ceramic compositions of Table 1 from darkening during subsequent thermal treatments.

[0164] In addition to the laser bleaching methods disclosed herein, the high contrast glass-ceramic compositions of the present invention are uniquely configured to achieve high absorbance in the unbleached region (i.e., less than 0.001% / mm transmittance in the visible and NIR regions), high transmittance in the bleached region (i.e., greater than 85% / mm transmittance in the visible and NIR regimes), and optical stability or retained transmittance in the bleached region after subsequent thermal treatment (i.e., greater than 85% / mm transmittance in the visible and NIR regimes is maintained). As used herein, the term "retained transmittance" refers to the transmittance through the glass-ceramic material after the material has been laser bleached and after the material has been subjected to subsequent thermal treatment (such as encountered during annealing and / or chemical strengthening by ion exchange).

[0165] Due to the specific dopant levels and ratios described above, the glass-ceramic compositions disclosed in Table 1 achieve a high dynamic range between bleached and unbleached regions. These compositions can be bleached according to the laser bleaching techniques disclosed herein to provide optical stability (i.e., retained transmittance) after thermal treatment (e.g., annealing and / or chemical strengthening by ion exchange). In embodiments, the bleached region or pore includes components of the silicate glass phase and the crystalline phase of the glass-ceramic, but is substantially free of M x WO3 species. As used herein, an pore that is "substantially free" of an indicated species is an pore in which the species may be present but at a sufficiently low concentration to achieve a specified retention permeability through the pore.

[0166] In embodiments, the bleached region or aperture may have a retained transmittance of at least 50% / mm at a wavelength from 500nm to 1,100nm, or at a wavelength from 450nm to 1,500nm, or at a wavelength from 450nm to 1,750nm, or at a wavelength from 400nm to 1,900nm, or at a wavelength from 350nm to 2,500nm (i.e., across the visible and NIR spectral range). In embodiments, the bleached region may have a retained transmittance of at least 60% / mm at a wavelength from 500nm to 1,100nm, or at a wavelength from 450nm to 1,500nm, or at a wavelength from 450nm to 1,750nm, or at a wavelength from 400nm to 1,900nm, or at a wavelength from 390nm to 2,500nm, or at a wavelength from 350nm to 2,500nm. In embodiments, the bleached region may have a retained transmittance of at least 70% / mm at a wavelength of from 500nm to 1,100nm, or at a wavelength of from 450nm to 1,500nm, or at a wavelength of from 450nm to 1,750nm, or at a wavelength of from 400nm to 1,900nm, or at a wavelength of from 400nm to 2,400nm, or at a wavelength of from 350nm to 2,500nm. In embodiments, the bleached region may have a retained transmittance of at least 80% / mm at a wavelength of from 500nm to 1,100nm, or at a wavelength of from 450nm to 1,500nm, or at a wavelength of from 450nm to 1,750nm, or at a wavelength of from 425nm to 1,900nm, or at a wavelength of from 425nm to 2,400nm, or at a wavelength of from 350nm to 2,500nm. In embodiments, the bleached region may have a retained transmittance of at least 85% / mm at a wavelength of from 500nm to 1,100nm, or at a wavelength of from 450nm to 1,500nm, or at a wavelength of from 450nm to 1,750nm, or at a wavelength of from 450nm to 1,900nm, or at a wavelength of from 450nm to 2,400nm, or at a wavelength of from 350nm to 2,500nm. In embodiments, the bleached region may have a retained transmittance of at least 90% / mm at a wavelength of from 600nm to 1,100nm, or at a wavelength of from 600nm to 1,500nm, or at a wavelength of from 600nm to 1,900nm, or at a wavelength of from 600nm to 2,400nm, or at a wavelength of from 350nm to 2,500nm. In embodiments, the bleached region may have a retained transmission of at least 85% / mm over a band at least 100 nm wide at any wavelength between 350 nm and 2,500 nm.

[0167] Example

[0168] The following examples represent certain non-limiting examples of compositions of glass-ceramic articles of the present invention, methods of bleaching glass-ceramic articles, and / or experiments evaluating various aspects of the methods disclosed herein.

[0169] Example 1 - Preheating

[0170] The temperature at which the sample is maintained during laser bleaching (ie, the preheat temperature) can affect the transparency of the bleaching window. Figure 7 is a graph showing the transmittance of the sample at 633 nm as a function of the stage temperature during laser bleaching. Figure 7 A decrease in transmittance for temperatures above about 480°C–500°C is shown when slow cooling is performed after laser bleaching. However, with rapid cooling / quenching (e.g., about 100°C / s after laser bleaching), the decrease in transmittance may be less pronounced. It has been observed that this preheating step prior to laser bleaching may be important for reducing sample failure due to stress accumulation. It has also been observed that when an appropriate preheating temperature is selected, stress relaxation during the bleaching process can be achieved. Therefore, in an exemplary embodiment, the preheating temperature is equal to or less than about 600°C, or in the range of about 100°C to about 600°C.

[0171] Example 2 - Irradiation and bleaching wavelengths

[0172] As previously mentioned, bleaching causes a significant drop in absorption as the alkali metal is delaminated from the crystal, particularly in the band from about 800 nm to about 2,600 nm. If the laser is operated in this wavelength range, the absorption drops relatively quickly to very low levels, thereby inhibiting the irradiated area from heating to a sufficiently high temperature (e.g., the dissolution temperature) to dissolve the tungsten bronze crystal. In order to heat the volume to the dissolution temperature, residual absorption in (and close to) the bleached state at the laser wavelength is desirable. Figure 8 illustrates this concept.

[0173] Figure 8 Figure 2 is a graph of the transmittance of unbleached and bleached glass ceramics of the sample. The area surrounded by two rectangular boxes of the dashed type in the figure represents the position of the preferred laser wavelength for bleaching. Figure 8 As shown in FIG. 8 , a rectangular frame 80 represents a first laser wavelength band in which residual absorption exists, and a rectangular frame 84 represents a second laser wavelength band in which residual absorption exists. From a practical point of view, the residual absorption is preferably between 5% / mm transmittance and 85% / mm transmittance in terms of transmittance. Therefore, the rectangular frame 80 represents that the first laser wavelength band (i.e., the lower laser wavelength band) is in the range of about 350nm to about 740nm, and the rectangular frame 84 represents that the second laser wavelength band (i.e., the upper laser wavelength band) is in the range of about 2,430nm to about 3,300nm.

[0174] It should be understood that Figure 8 The transmittance and corresponding wavelengths plotted in are approximate and may vary to some extent for different compositions and with temperature. Therefore, for some compositions, the residual absorption in terms of transmittance is preferably between a different transmittance range than shown above, for example, between 10% / mm transmittance and 85% / mm transmittance. For this different transmittance range, the first or lower laser band is in the range from about 360nm to about 620nm, and the second or higher laser band is in the range from about 2,690nm to about 3,300nm. In embodiments, the residual absorption in terms of transmittance is preferably less than or equal to 70% / mm, otherwise complete bleaching may not be achieved with reasonable laser power. In embodiments, some compositions may have only one laser band within which there is sufficient residual absorption to provide the necessary heating as discussed previously.

[0175] Example 3 - Annealing and Threshold Temperature

[0176] In situ absorbance measurements made during crystal formation in the glass-ceramics disclosed herein show that the transmittance of these materials remains high and nearly constant over the hold time at the peak temperature of the thermal cycle. Fig. 9 As shown, when the material reaches a temperature between 460°C and 470°C, the transmittance decreases rapidly during cooling. Fig. 9 In-situ transmittance measurements of a tungsten glass-ceramic sample heated to 525°C at a ramp rate of 20°C / m, held for 30 minutes, cooled to 450°C at 1°C / m, and then cooled at the furnace rate are plotted. During the experiment, transmittance measurements were taken approximately every 5 minutes. As can be observed, the transmittance decreases rapidly when the sample reaches a temperature between 460°C and 470°C.

[0177] Ex situ Raman spectroscopy and the interpretation of these observations led to the hypothesis that stoichiometric tungsten oxide is formed during the hold period at the peak temperature of the pottery cycle, and that during cooling in this narrow temperature range, partial reduction of these crystals and subsequent intercalation of alkali metal cations occurs. To further confirm that this rapid change in transmittance is associated with the threshold temperature regime, additional in situ optical measurements were collected in which the sample was held at a temperature slightly above this threshold temperature for 1.8 hours and then reduced to the threshold temperature regime. During the extended hold time, the transmittance changes are minimal until the temperature is reduced to the threshold temperature regime, where it is believed that the alkali metals are intercalated into the crystals and the transmittance decreases rapidly, as shown in Figure 2. Fig.10 as shown in . Fig.10The in-situ transmittance measurement of a tungsten glass ceramic sample that was heated to 565°C at a rate of 30°C / min and then held at 565°C for 15 min is plotted. The sample was then rapidly cooled to 475°C and held for about 1.8 h. Subsequently, the sample was rapidly cooled to 465°C and held for 10 minutes. Afterwards, the heater was turned off and cooled to room temperature.

[0178] It has been observed that if the sample is annealed above the threshold temperature range in which the base is intercalated (e.g., T≥465°C), rapid cooling through this temperature to room temperature results in less transmittance loss than when cooling is slower (e.g., furnace speed (2.6°C / m)). More significantly, it has been observed that the transparency of the bleached pore can also be maintained if the sample is annealed at a temperature just below the threshold temperature regime (e.g., 12h at 460°C). In contrast, if the sample is annealed for the same duration at the threshold temperature regime, the sample becomes noticeably darker. After annealing, the optical retardation per unit thickness in the bleached region can be <12nm / mm, or preferably <10nm / mm.

[0179] Annealing (or stress relief) can be performed as a separate step in a furnace after laser bleaching, or can be performed as part of the laser bleaching process, or as a combination of both. For example, stress can be relieved to some extent by keeping the sample on a heating stage (e.g., at 500°C) for a period of time before unloading and rapid cooling to <=460°C to avoid darkening of the bleached area.

[0180] In addition, measures can be taken to promote more stress relief in dark unbleached regions (which may have higher tensile stress) by maintaining these regions at a slightly higher temperature than the bleached regions. For example, the bleached regions can be maintained at a temperature slightly below a threshold temperature (e.g., about 460°C) for a period of time, and the unbleached regions can be maintained at a temperature above the threshold temperature range (e.g., >470°C). This temperature difference can be promoted by: (i) using a heater plate that preferentially heats the unbleached regions, for example, by having holes corresponding to the bleached regions, or (ii) by using a mid-IR heater that preferentially heats the unbleached regions. In both cases, the bleached regions can be actively cooled by conduction (e.g., cooler metal prongs contact the bleached orifices) or convection (blowing a cooling fluid such as air onto the bleached regions) to prevent the bleached regions from heating due to conduction within the sample.

[0181] Next, if Fig.11 As shown in , before the entire sample is cooled to room temperature, the unbleached area can be gradually cooled to the same temperature as the bleached area and kept there for a period of time to further relieve stress. Fig.11Temperature versus time is plotted to illustrate how, during the annealing process, the bleached regions can be selectively cooled relative to the unbleached regions, allowing stress relief without re-darkening the bleached regions. This heat treatment can be performed immediately after laser bleaching (e.g., without cooling the sample to room temperature), or can be performed in a subsequent annealing step.

[0182] In embodiments, the bleached regions can then be preferentially heated (e.g., with a laser) to above the base embedding temperature to reduce the virtual temperature difference between the bleached and unbleached regions and relieve stress. A potential advantage is that faster cooling of the bleached regions can be achieved compared to heating the entire sample.

[0183] In embodiments, the annealing time and temperature may be adjusted to achieve different colors in the bleached area. In embodiments, the sample may appear completely dark but show a pattern under backlighting. The residual birefringence in the bleached window of the part / article (before ion exchange) should be less than about 200 nm / mm.

[0184] Example 4 - Annealing, Cation Identity and Crystallization Rate

[0185] Experiments were performed to evaluate whether the increased optical stability could be affected by the identity of the alkali cation, where diffusion and insertion rates decrease with increasing radius of the alkali cation (with Li being the fastest, followed by Na, K, and then Cs). Figures 12 and 13 show these experiments.

[0186] Fig. 12A Images and compositions (in as-batched mol%) of annealed cakes of glass-ceramics 714BBL (prepared with only Li) and 714BBM (prepared with only Na) cast on a steel table and annealed are shown. The Li-containing composition (714BBL) spontaneously crystallized upon pouring and turned a dark blue, indicating a higher crystallization rate than the sodium analog (714BBM). Fig. 12B Images of a ~2 mm thick splat quenched sheet and subsequent splat quenched glass samples heat treated at 600°C for 2 h and 650°C for 1 hour and 24 minutes are shown. As shown, the Li-containing glass changes color (i.e., crystallizes) after heat treatment at 600°C for 2 h, while the sodium analog does not crystallize until heat treated at 50°C higher. Despite this rate difference, the absorbance is similar, as shown in Figure 1. Fig. 12C Furthermore, this difference in crystallization rate does not seem to be due to differences in viscosity between the two glasses. In fact, the Na analogue has a lower strain and annealing point (see Fig.12D ), which may indicate that its diffusion occurs faster at a fixed temperature relative to the lithium analog.

[0187] Fig.13A Shown in Fig. 13B Images of Li, Na, K, and Cs analogs (glass codes 714BBL, M, N, and J, respectively) samples heat treated over a range of temperatures (500-800°C) in a "staircase" pattern are shown. Despite the differences in alkali metal identity, the annealing temperatures of the Li, Na, K, and Cs analogs are similar: 563.1°C, 522.2°C, 553.7°C, and 566.1°C, respectively. This similarity in annealing temperatures suggests that this difference in crystallization rate is not driven by differences in viscosity, but rather by differences in diffusivity and the ability of the alkali cations to intercalate into the crystal channels (i.e., the smaller the alkali metal, the easier it is to "fit" into the crystal).

[0188] Example 5 - Irradiation and Laser Parameters

[0189] Experiments were conducted to evaluate the influence of certain laser parameters. In general, the higher the temperature caused by laser irradiation, the better the transparency achieved with more complete dissolution of the tungsten bronze crystals. However, at temperatures above a certain value (referred to as the "maximum temperature" elsewhere in this disclosure), high tensile stresses within the bleaching window can lead to microbubbles (defects) within the window. Such defects can be avoided by defocusing the laser beam and / or choosing a shorter irradiation time. Fig.14 The effect of defocusing the laser beam is shown. Fig.14 Four side-by-side photographs of four different bleaching windows formed by different beam spot sizes are shown, with the beam spot size increasing in increments of about 10% in each of photographs #2-#4 from about 0.4 mm in photograph #1. Fig.14 As shown in , the defects are not visually detectable in photos #2-#4. In embodiments, absorption at the laser bleaching wavelength is also a factor in whether defects are formed during the bleaching process, and shorter laser wavelengths (eg, less than about 2.72 μm) may help avoid such defects.

[0190] Fig.15 The effect of irradiation time on the bleaching window diameter is shown. By changing the laser beam focusing conditions (#1 to #4, which correspond to Fig.14 The experiments were conducted with the laser beam focusing conditions #1 to #4) and a range of irradiation durations. Fig.15 As shown in , the bleaching window diameter is not greatly affected by the beam spot diameter, but is mainly affected by the irradiation time.

[0191] Although some of the laser parameters discussed in the present disclosure are configured to form one or more orifices with a target diameter in the range of about 2 mm to about 3 mm, other sizes and configurations of orifices may also be considered. In an embodiment, the target diameter may be in the range of from about 2 mm to about 4 mm, or from about 1.5 mm to about 3.5 mm, or from about 0.2 mm to about 2.5 mm, or from about 1 mm to about 4.5 mm, or from about 1 mm to about 5 mm, or greater or less than those described herein. In such embodiments, the laser parameters may be adjusted to form orifices with different target diameters. In an embodiment, the laser parameters are generally increased (e.g., higher laser power, larger beam spot size, longer irradiation time, etc.) to form an orifice with a target diameter greater than about 2 mm to about 3 mm. On the contrary, the laser parameters are generally reduced (e.g., lower laser power, smaller beam spot size, shorter irradiation time, etc.) to form an orifice with a target diameter less than about 2 mm to about 3 mm.

[0192] In embodiments, during irradiation, the laser parameters are fixed or static, such that each laser parameter remains substantially the same during irradiation. In embodiments, the laser parameters are dynamically adjustable during irradiation (e.g., on-line), such that each laser parameter can have multiple different values ​​and / or settings (e.g., different wavelengths, laser powers, focal points, beam spot sizes, irradiation times, etc.) during irradiation. Such dynamic adjustments can be useful for controlling heating during irradiation (e.g., to avoid exceeding a maximum temperature) and / or varying the degree of bleaching completeness between apertures and / or within the same aperture (e.g., between partial and complete bleaching).

[0193] Example 6 - Transmittance Measurement

[0194] The samples were prepared and processed according to the principles of the present invention. Each sample comprised a plate or chip formed from the same bulk glass composition. The length and width of each glass chip were roughly square, with sufficient area to accommodate the pattern of bleaching orifices (e.g., six to twelve orifices per sample). The thickness of the glass chip ranged from about 1.0 mm to about 1.1 mm. The diameter of the orifice 36 formed in each sample was about 2-3 mm. Fig.16 is a magnified digital image of the top surface of one of the samples showing a single aperture 36 (eg, a bleached region) surrounded by bulk glass 42 (eg, an unbleached region).

[0195] The bulk glass composition for the samples was developed through ongoing experimentation and was similar to the composition described above. The bulk glass composition for the samples included about 64.96 mol% silicon dioxide, about 10.83 mol% aluminum (III) oxide, about 9.38 mol% boron trioxide, about 5.84 mol% lithium oxide, about 4.69 mol% sodium oxide, about 0.25 mol% tin (II) oxide, about 3.9 mol% tungsten (VI) oxide, and about 0.15 mol% molybdenum (IV) oxide.

[0196] First, the sample is ceramicized according to the following ceramic schedule: heated to about 525°C, kept for about 16 hours, cooled to about 425°C at a rate of about 0.5°C / minute, and then cooled to roughly room temperature (e.g., an ambient air furnace for heating) with a furnace speed. After the sample is ceramicized, the aperture pattern is bleached into each sample. As described in Example 2, the bleaching wavelength is selected from one of a lower laser band and a higher laser band. During laser bleaching, the sample is heated to a preheating temperature in the range of from about 530°C to about 590°C. After the sample is bleached, the sample is annealed according to the following annealing schedule: heated to about 463.1°C at a rate of about 3°C / minute, kept at this temperature for about 3.5 hours to 4.5 hours, and then cooled with a furnace speed (e.g., in an ambient air furnace, about 2.6°C / minute).

[0197] Measurements were performed to evaluate the transmittance of each sample in 1 nm increments over the wavelength range from 350 nm to 1000 nm. UV-VIS-NIR transmittance was measured using an Ocean Optics QE Pro spectrophotometer with a Small Spot UMA accessory. The modular spectrophotometer setup included the following parameters: Integration time - 100 ms (sample spectrophotometer), 500 ms (reference spectrophotometer); Scans - 40 (sample spectrophotometer), 8 (reference spectrophotometer); Electronic dark - off; Nonlinear correction - off. Source optics included: Energetiq EQ99 source, coupled to input fiber, with 2", 75 mm FL lens; and 115 μm anti-overexposure fiber - coupled to Small Spot UMA. Detector optics included: Small Spot UMA with 2" sphere; 1000 μm fiber; and QEPro spectrophotometer with 25 μm slit. On the small spot UMA accessory, the axial transmission of the sample was measured relative to the open beam baseline.

[0198] Fig.176 is a graph of the transmittance of the bleaching orifice 36 in the sample prepared according to Example 6 (hereinafter referred to as "Sample 6-1") within the wavelength range. As shown in the figure, within the measured wavelength range, Sample 6-1 achieves a transmittance of at least 85% / mm in a band with a width greater than about 500nm. Within the measured wavelength range, Sample 6-1 achieves a transmittance of at least 90% / mm in a band with a width greater than about 400nm. Within the measured wavelength range, Sample 6-1 achieves a transmittance of at least 91% / mm in a band with a width greater than about 300nm.

[0199] Fig.18 and Fig.19 Graphs showing transmittances of the bulk glass 42 and the bleaching aperture 36 in a wavelength range (eg, 350 nm to 2,400 nm) in a sample prepared according to Example 6 (hereinafter referred to as “Sample 6-2”), respectively. Fig. 20 is the bleaching orifice 36 ( Fig.19 ) and the transmittance of the main glass 42( Fig.18 ) in the same wavelength range. Fig. 20 As shown in FIG. , within a ratio band extending 100 nm between wavelengths of about 350 nm to about 2,500 nm (e.g., where the ratio band is centered at a wavelength of about 450 nm), the ratio between the transmittance of the aperture 36 (e.g., the first transmittance) and the transmittance of the body glass 42 (e.g., the body transmittance) is at least 1.0×10 5 .like Fig. 20 As shown in FIG. , within a ratio band extending 100 nm between wavelengths of about 350 nm to about 2,500 nm (e.g., where the ratio band is centered at a wavelength of about 1,340 nm), the ratio between the transmittance of the aperture 36 (e.g., the first transmittance) and the transmittance of the body glass 42 (e.g., the body transmittance) is at least 8.0×10 26 .

[0200] Although the present invention has been shown and described in detail in the drawings and the foregoing description, it should be considered as illustrative rather than restrictive. It should be understood that only preferred embodiments have been presented and that all changes, modifications and further applications falling within the spirit of the invention are intended to be protected.

Claims

1. A method for bleaching a glass-ceramic product, comprising: A first portion of a glass-ceramic article body is irradiated by directing a beam of light from a laser into the thickness of the body to heat the first portion and form a first aperture therein, the body having an amorphous silicate glass phase, a crystalline phase, and a bulk transmittance, the first aperture having a first transmittance greater than the bulk transmittance at a first wavelength of 350 nm to 2500 nm, the beam of light comprising a bleaching wavelength selected from a laser wavelength band within which residual absorption persists in the aperture after irradiation at the bleaching wavelength. 2 . The method of claim 1 , wherein the laser wavelength bands include at least two non-overlapping laser wavelength bands.

3. The method of claim 1 or claim 2, wherein the laser wavelength band comprises a lower laser wavelength band adjacent to and / or overlapping a lower end of the first wavelength.

4. The method according to any one of claims 1 to 3, wherein the lasing wavelength band comprises a higher lasing wavelength band adjacent to and / or overlapping an upper end of the first wavelength.

5. The method according to any one of claims 1 to 4, wherein the residual absorption persists in the aperture in the range of about 5% / mm to about 85% / mm in terms of transmittance within the laser wavelength band after irradiation.

6. The method according to any one of claims 1-5, wherein the crystalline phase comprises M x WO3 material, where 0 < x < 1, and where M is an intercalated doping cation.

7. The method according to claim 6, wherein the M x The WO3 species corresponds to the main absorbing species into which the bleaching wavelength is coupled during the irradiation.

8. The method of claim 7, wherein the body comprises a secondary absorbing species into which the bleaching wavelength is coupled during the irradiation, the secondary absorbing species being different from the primary absorbing species so as to provide the residual absorption.

9. The method of claim 8, wherein the secondary absorbent species comprises chemical hydroxyls.

10. The method of claim 8 or claim 9, wherein the secondary absorbing species comprises an ultraviolet (UV) absorption edge of the glassy phase.

11. The method of any one of claims 8-10, wherein the secondary absorber species comprises a dopant, the method further comprising doping the body with the dopant prior to the irradiating.

12. The method of claim 11, wherein the dopant comprises one or more of Ce, Er, Tb, Pr, Mn, Ti, Cu, Co, Ni, Fe, Cr, V, Ag, and Au in oxide or metallic form.

13. The method of claim 11 or claim 12, wherein the body comprises less than 2.5 mol% of the dopant selected from the group consisting of Ce, Er, Pr, Tb, and combinations thereof.

14. The method of any one of claims 11-13, wherein the body comprises less than 0.5 mol% of the dopant selected from the group consisting of: Mn, Ti, Cu, Co, Ni, Fe, Cr, V, Ag, Au, and combinations thereof.

15. The method of any one of claims 6 to 14, wherein the irradiation is configured to heat the first portion of the body to a temperature where the crystalline phase x The WO3 substance is substantially dissolved to the dissolution temperature in the body.

16. The method of claim 15, wherein the dissolution temperature is higher than the M x The liquidus temperature of WO3 substance.

17. The method of claim 15 or claim 16, wherein the dissolution temperature is in the range of about 600°C to about 1,100°C.

18. The method of any one of claims 15-17, wherein the dissolution temperature is in the range of about 900°C to about 1,100°C.

19. The method of any one of claims 1-18, wherein directing a beam from a laser comprises adjusting a focus of the beam so that a maximum temperature is not exceeded within the first portion of the body during the irradiating.

20. The method of any of claims 1-19, wherein the laser comprises a mid-infrared (IR) laser, the light beam being directed from the mid-IR laser using a plurality of laser parameters.

21. The method of claim 20, wherein the laser parameters include a laser power in a range of about 17.5 W to about 39.0 W.

22. The method of claim 20, wherein the laser parameters include a laser power in a range of about 25.0 W to about 30.0 W.

23. The method of any one of claims 20-22, wherein the laser parameters include a beam spot size in the range of about 0.20 mm to about 1.50 mm.

24. The method of any one of claims 20-22, wherein the laser parameters include a beam spot size in the range of about 0.40 mm to about 1.0 mm.

25. The method of any one of claims 20-24, wherein the laser parameters include an illumination time in the range of about 0.70 s to about 12.0 s.

26. The method of any one of claims 20-24, wherein the laser parameters include an illumination time in the range of about 0.40 s to about 8.0 s.

27. The method of any one of claims 20-26, wherein the laser parameters are configured to form the first aperture having a target diameter.

28. The method of claim 27, wherein the target diameter is in the range of about 0.2 mm to about 5 mm.

29. The method of any one of claims 1-28, wherein the irradiating further comprises irradiating a second portion of the body by directing the beam from the laser into the thickness of the body to heat the second portion and form a second aperture therein, the second aperture having a second transmittance greater than the body transmittance at the first wavelength.

30. The method of claim 29, wherein the second aperture is spaced apart from the first aperture.

31. A method according to claim 29 or claim 30, wherein the irradiating to form the first aperture and the irradiating to form the second aperture are performed simultaneously.

32. A method according to claim 29 or claim 30, wherein the irradiation to form the first orifice and the irradiation to form the second orifice are performed sequentially with a dwell time in between.

33. The method of any one of claims 29-32, further comprising contacting a first heat sink portion with a first surface of the body configured to be irradiated, the first heat sink portion defining a corresponding first through hole, the light beam from the laser being directed or passing through the first through hole to form the first and second apertures in the body.

34. The method of claim 33, further comprising contacting a second heat sink portion with a second surface of the body, the second surface opposite the first surface such that the first heat sink portion and the second heat sink portion sandwich the body.

35. The method of claim 34, wherein a second heat sink portion defines respective second through holes through which the light beam from the laser is directed to form the first and second apertures in the body.

36. The method of any one of claims 1-35, further comprising preheating the glass-ceramic article prior to the irradiating.

37. The method of claim 36, wherein the preheating comprises heating the glass-ceramic article to a preheat temperature in a range of about 100°C to about 600°C.

38. The method of claim 36, wherein the preheating comprises heating the glass-ceramic article to a preheat temperature in a range of about 200°C to about 575°C.

39. The method of claim 36, wherein the preheating comprises heating the glass-ceramic article to a preheat temperature in a range of about 300°C to about 500°C.

40. The method of any one of claims 1-39, further comprising annealing the glass-ceramic article by heating the glass-ceramic article to an annealing temperature.

41. The method of claim 40, wherein the annealing temperature is outside a threshold temperature so as to substantially maintain the first transmittance, and wherein the annealing further comprises: maintaining the annealing temperature for a first duration, and The glass-ceramic article is rapidly cooled from the annealing temperature to room temperature at a cooling rate substantially greater than a furnace rate.

42. The method of claim 41, wherein the first duration is about 12 hours.

43. The method of claim 40, wherein the annealing temperature comprises a first annealing temperature and a second annealing temperature greater than the first annealing temperature, wherein the first annealing temperature and the second annealing temperature are outside a threshold temperature so as to substantially maintain the first transmittance, and wherein the annealing further comprises: heating the first orifice to the first annealing temperature, heating the body to the second annealing temperature, gradually cooling the body to the first annealing temperature, and The first aperture and the body are rapidly cooled from the first annealing temperature to room temperature at a cooling rate substantially greater than a furnace rate.

44. The method of claim 43, wherein heating the body to the second annealing temperature comprises heating the body using a heating plate, the heating plate defining at least one through hole aligned with the first aperture.

45. The method of claim 43, wherein heating the body to the second annealing temperature comprises heating the body using a mid IR heater.

46. ​​A method according to claim 44 or claim 45, wherein during heating of the body to the second annealing temperature the first aperture is actively cooled by one or more of conduction and convection.

47. The method of any one of claims 41-46, wherein after the annealing, the first transmittance decreases by less than 5% / mm.

48. The method of claim 40, wherein the annealing further comprises setting the annealing temperature to a threshold temperature for a period of time to reduce the first transmittance.

49. The method of claim 40, wherein the annealing further comprises setting the annealing temperature to gradually pass a threshold temperature so as to reduce the first transmittance.

50. The method of claim 48 or claim 49, wherein after said annealing, said first transmittance decreases by at least 5% / mm.

51. The method of any one of claims 41-50, wherein the threshold temperature is in the range of greater than about 460°C to about 500°C.

52. The method of any one of claims 40-51, further comprising ion exchanging the glass-ceramic article in a bath containing sodium nitrate and / or potassium nitrate at a temperature between 360 and 450°C for a period of 0.25 to 25 hours.

53. The method of claim 52, wherein the residual birefringence in the first pore after the annealing and before the ion exchanging is less than about 200 nm / mm.

54. The method of any one of claims 1-53, wherein the first transmittance is selectable between about 1% above the bulk transmittance and about 91% / mm transmittance at the first wavelength.

55. The method of any one of claims 29-54, wherein the second transmittance is selectable between about 1% above the bulk transmittance and about 91% / mm transmittance at the first wavelength.

56. The method of any one of claims 1-55, wherein at the first wavelength, the bulk transmittance is in a range from about 0.001% / mm to about 1% / mm.

57. The method of any one of claims 1-56, wherein the ratio between the first transmittance and the bulk transmittance is at least 1.0×10 5 .

58. The method of claim 57, wherein the ratio band is centered at a wavelength of 450 nm.

59. The method of any one of claims 1-56, wherein the ratio between the first transmittance and the bulk transmittance is at least 8.0×10 26 .

60. The method of claim 59, wherein the ratio band is centered at a wavelength of 1340 nm.

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