CN118666493A - Glass ceramic and glass - Google Patents

Abstract

The present application relates to glass ceramics and glass. The glass ceramics include: silicate glass and a crystalline phase, wherein the crystalline phase includes non-stoichiometric suboxides of tungsten and/or molybdenum (or titanium), forming a 'bronze' type solid defect structure, wherein vacancies are occupied by dopant cations.

Description

Glass Ceramics and Glass

Cross Reference

This application claims priority to U.S. Application No. 62/575,763, filed on October 23, 2017, and is a continuation-in-part of U.S. Application No. 15/840,040, filed on December 13, 2017, the contents of both applications are incorporated herein by reference in their entirety.

Technical Field

The present disclosure relates generally to articles comprising glass and/or glass-ceramics and, more particularly, to compositions and methods of forming such articles.

Background Art

Alkali silicate glass-ceramics with ultraviolet ("UV") and near infrared ("NIR") absorption are a class of glass-ceramics that exhibit optical properties depending on the wavelength of light impinging on the glass-ceramic. Conventional UV/IR blocking glasses (having low or high visible light transmittance) are formed by introducing certain cationic species (e.g., Fe2+ to absorb NIR wavelengths, Fe23+ to absorb UV wavelengths, and other dopants (e.g., Co, Ni, and Se) to modify visible light transmittance) that are combined with the glass network. Generally speaking, these glass-ceramics are produced by melting the components together to form a glass, followed by in-situ formation of submicron precipitates by post-forming heat treatment to form the glass-ceramic. These submicron-sized precipitates (e.g., tungstate-containing and molybdate-containing crystals) are absorptive for a band of light wavelengths, giving the glass-ceramic its own optical properties. Such conventional glass-ceramics produced can be in a transparent form as well as in an opalescent form.

It is believed that in order to produce glass and glass ceramics that are transparent at visible wavelengths, conventional tungsten-containing and molybdenum-containing alkali silicate glasses are limited to specific and narrow composition ranges. The composition range believed is based on the perceived solubility limit of tungsten oxide in over-alkaline glass. For example, when batching and melting are carried out in a conventional manner, at low temperatures during the initial stage of the melt immediately after being placed in a melting furnace, tungsten oxide can react with the alkali metal tungsten oxide in the batch material to form a dense alkaline tungstate liquid (for example, the reaction occurs at about 500°C). Due to this high-density phase, it is quickly separated at the bottom of the crucible. At significantly higher temperatures (for example, higher than about 1000°C), the silicate component begins to melt, and due to the lower density of the silicate component, it stays on the top of the alkaline tungstate liquid. The density difference of the components causes the stratification of different liquids, which makes those skilled in the art believe that they are mutually immiscible. This effect is particularly observed when _R2O (e.g., _Li2O , _Na2O , _K2O , _Rb2O , _Cs2O ) minus _Al2O3 is about 0 mol% or greater. The resulting apparent liquid immiscibility at the melting temperature causes the tungsten-rich _phase to separate and crystallize as it cools, which manifests itself as milky, opaque crystals. This problem also exists with molybdenum-containing melts.

Those skilled in the art have observed that the tungsten-rich phase and/or the molybdenum-rich phase separate from the silicate-rich phase, and they believe that there is a solubility limit for tungsten and/or molybdenum in the silicate-rich phase (e.g., about 2.5 mol%). The solubility limit that is believed to prevent the glass from becoming supersaturated with tungsten oxide or molybdenum oxide, thereby preventing the formation of glass-ceramics having crystalline phases containing these elements by controlled precipitation of components formed after heat treatment. Therefore, the solubility that is believed to prevent the development of such glass-ceramic compositions that achieve sufficient soluble tungsten and/or molybdenum to achieve the formation of wavelength-dependent submicron-sized crystals containing tungsten and/or molybdenum by subsequent heat treatment.

In view of these limitations, new compositions and methods are needed to make them useful for improving near-IR and UV blocking (eg, through higher tungsten and molybdenum solubility).

Summary of the invention

It has been discovered that a homogeneous single-phase W- or Mo-containing superalkaline melt can be obtained by using a "bound" alkaline material as described herein. Exemplary bound alkaline materials may include: feldspar, nepheline, borax, spodumene, other sodium or potassium feldspars, minerals containing alkaline aluminosilicates and/or other naturally occurring or artificial alkaline materials and one or more aluminum and/or silicon atoms. By introducing the alkaline material in a bound form, the alkaline material may not react with W or Mo present in the melt to form a dense alkaline tungstate and/or alkaline molybdate liquid. In addition, this batch change can achieve the melting of strongly superalkaline compositions (e.g., R ₂ O-Al ₂ O ₃ = about 2.0 mol% or greater) without the formation of any alkaline tungstate and/or alkaline molybdate second phases. This also allows for changing the melting temperature and mixing method and still producing a single-phase homogeneous glass.

According to aspects of the present disclosure, the glass-ceramic comprises: a silicate glass and a crystalline phase, wherein the crystalline phase comprises non-stoichiometric low-valent oxides of tungsten and/or molybdenum (or titanium), forming a 'bronze' type solid state defect structure, wherein vacancies are occupied by dopant cations.

In some embodiments, the glass-ceramic includes an amorphous phase and a crystalline phase, wherein the crystalline phase comprises a plurality of precipitates of the formula M _x WO ₃ and/or M _x MoO ₃ , wherein 0<x<1 and M is a dopant cation. In some such embodiments, the length of the precipitates is from about 1 nm to about 200 nm, as measured by electron microscopy. The precipitates of the crystalline phase may be substantially uniformly distributed in the glass-ceramic.

In addition, the glass-ceramic may include an amorphous phase and a crystalline phase, wherein the crystalline phase includes a plurality of precipitates of the formula M _x TiO ₂ , wherein 0<x<1 and M is a dopant cation. In some embodiments, the length of the precipitate is from about 1 nm to about 200 nm, or from 1 nm to about 300 nm, or from 1 nm to about 500 nm, as measured by electron microscopy. The precipitates of the crystalline phase may be substantially uniformly distributed in the glass-ceramic.

In some embodiments, the glass ceramic comprises a silicate glass and crystals of a non-stoichiometric ratio of tungsten and/or molybdenum suboxides uniformly distributed in the silicate glass and inserted with dopant cations. The glass ceramic may have a transmittance of about 5% or more per mm over at least one 50 nm wide wavelength band in the range of about 400 nm to about 700 nm. The dopant cations may be: 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, Cu, Pd, Se, Ta, Bi and/or Ce. In some such embodiments, at least some of the crystals are located at a depth greater than about 10 μm from the outer surface of the glass ceramic. The crystals may have a rod-like morphology.

In some embodiments, the glass-ceramic includes a silicate glass phase and a crystalline phase, wherein the crystalline phase includes a subvalent oxide of tungsten and/or molybdenum forming a solid defect structure, wherein the holes in the solid defect structure are occupied by dopant cations. The volume fraction of the crystalline phase in the glass-ceramic can be about 0.001% to about 20%.

In other embodiments, the glass-ceramic comprises a silicate glass and crystals of a non-stoichiometric titanium suboxide with dopant cations inserted therein uniformly distributed therein; and/or comprises a silicate glass phase and a crystalline phase comprising titanium suboxides forming a solid defect structure in which holes are occupied by dopant cations.

In some embodiments, the article includes at least one amorphous phase and one crystalline phase, the article comprising from about 1 mol% to about 95 mol% _SiO2 as a batch component. The crystalline phase includes an oxide of at least one of (i) W, (ii) Mo, (iii) V and an alkali metal cation, and (iv) Ti and an alkali metal cation. The article may be substantially free of Cd and Se.

In other embodiments, the glass (e.g., a glass precursor for a glass ceramic) comprises the following batch components: _SiO2 from about 25 mol% to about 99 mol%, _{Al2O3 from} about 0 mol% to about 50 mol%, _WO3 plus _MoO3 from about 0.35 mol% to about 30 mol%, _R2O from about 0.1 mol% to about 50 mol%, wherein _R2O is one or more of _Li2O , _Na2O , _K2O , _Rb2O , and _Cs2O , and wherein _{R2O minus Al2O3} is about -35 mol% to about 7 mol%. In some such embodiments, at least one of the following conditions exists: (i) RO ranges from about 0.02 mol% to about 50 mol%, and (ii) _SnO2 is about 0.01 mol% to about 5 mol%, wherein RO is one or more of MgO, CaO, SrO, BaO, and ZnO. In some such embodiments, if WO ₃ is about 1 mol % to about 30 mol %, the glass further comprises about 0.9 mol % or less of Fe ₂ O ₃ , or SiO ₂ is about 60 mol % to about 99 mol %. If WO ₃ is about 0.35 mol % to about 1 mol %, the glass may comprise about 0.01 mol % to about 5.0 mol % SnO ₂ . If MoO ₃ is about 1 mol % to about 30 mol %, the SiO ₂ may range from about 61 mol % to about 99 mol %, or Fe ₂ O ₃ may be about 0.4 mol % or less and R ₂ O is greater than RO. If MoO ₃ is about 0.9 mol % to about 30 mol % and SiO ₂ is about 30 mol % to about 99 mol %, the glass may further comprise about 0.01 mol % to about 5 mol % SnO ₂ .

In some embodiments, a method of forming a glass-ceramic comprises: melting together to form a glass melt: (1) a bound alkaline substance, (2) silicon dioxide, and (3) tungsten and/or molybdenum; solidifying the glass melt into glass; and precipitating a crystalline phase in the glass to form a glass-ceramic article. The glass can be a single homogeneous solid phase. The crystalline phase can contain tungsten and/or molybdenum. In addition, in some such embodiments, the bound alkaline substance comprises: (A) feldspar, (B) nepheline, (C) sodium borate, (D) spodumene, (E) albite, (F) potassium feldspar, (G) alkali-containing aluminum silicate, (H) alkali-containing silicate, and/or (I): (I-i) an alkaline substance bound to aluminum oxide, (I-ii) an alkaline substance bound to boron oxide, and/or (I-iii) an alkaline substance bound to silicon oxide.

In other embodiments, a method of forming a glass-ceramic includes the steps of melting silicon oxide with tungsten and/or molybdenum to form a glass melt; solidifying the glass melt to form glass; and precipitating bronze-type crystals containing tungsten and/or molybdenum in the glass. Precipitation of the crystalline phase may include thermally processing the glass. In at least some such embodiments, the method further includes the step of growing the precipitate of the crystalline phase to a length of at least about 1 nm and not more than about 500 nm.

In other embodiments, the glass-ceramic includes a silicate-containing glass phase; and a crystalline phase comprising a titanium suboxide, the titanium suboxide including a solid state defect structure in which holes are occupied by dopant cations.

In other embodiments, the glass-ceramic includes an amorphous phase; and a crystalline phase comprising a plurality of precipitates having a chemical formula of M _x TiO ₂ , wherein 0<x<1 and M is a dopant cation.

In other embodiments, the glass-ceramic includes a silicate-containing glass; and a plurality of crystals uniformly distributed in the silicate-containing glass, wherein the crystals include a suboxide of titanium in a non-stoichiometric ratio, and wherein the crystals are intercalated with dopant cations.

In other embodiments, the glass-ceramic article comprises at least one amorphous phase and a crystalline phase; and about 1 mol % to about 95 mol % SiO ₂ ; wherein the crystalline phase comprises about 0.1 mol % to about 100 mol % of a non-stoichiometric titanium suboxide of the crystalline phase, the oxide comprising at least one of: (i) Ti, (ii) V, and an alkali metal cation.

In other embodiments, a method of forming a glass-ceramic includes: melting components comprising silicon dioxide and titanium together to form a glass melt; allowing the glass melt to solidify to form glass, wherein the glass includes a first average near-infrared absorptivity; and precipitating a crystalline phase in the glass to form a glass-ceramic, wherein the glass-ceramic includes: (a) a second average near-infrared absorptivity, wherein a ratio of the second average near-infrared absorptivity to the first average near-infrared absorptivity is about 1.5 or greater, and (b) an average optical density per mm of about 1.69 or less.

In other embodiments, in batch components, the glass comprises: _SiO2 from about 1 mol% to about 90 mol%; _{Al2O3 from} about 0 mol% to about 30 mol%; _TiO2 from about 0.25 mol% to about 30 mol%; metal sulfides from about 0.25 mol% to about 30 mol%; _R2O from about 0 mol% to about 50 mol%, wherein _R2O is one or more of _Li2O , _Na2O , K2O, _Rb2O , _{and Cs2O ;} and RO from about 0 mol% to about 50 mol%, wherein RO is one or more of BeO, MgO, CaO, SrO, BaO, and ZnO, wherein the glass is substantially free of Cd.

These and other features, advantages and objects of the present disclosure will be further understood and appreciated by those skilled in the art by referring to the following description, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings provide further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate one or more embodiments and together with the detailed description are used to explain the principles and operations of the various embodiments. Therefore, the present disclosure will be better understood through the following detailed description in conjunction with the accompanying drawings, in which:

1 is a cross-sectional view of an article according to at least one example of the present disclosure, the article including a substrate including a glass-ceramic composition.

2A is a graph of transmittance versus wavelength for a comparative CdSe glass and a heat-treated glass-ceramic according to at least one example of the present disclosure.

FIG. 2B is an image of FIG. 2A rescaled to show the cutoff wavelengths of the comparative CdSe glass and the heat treated glass-ceramic sample.

3A is a graph of transmittance versus wavelength for comparative CdSe glass and glass-ceramic samples heat treated according to various conditions from 525° C. to 700° C. according to examples of the present disclosure.

3B is the image of FIG. 3A rescaled to show the cutoff wavelengths of the comparative CdSe glass and the glass-ceramic samples heat treated according to various conditions.

4A is a graph of transmittance versus wavelength for comparative CdSe glass and glass-ceramic samples heat treated at 700° C. and 800° C. according to various conditions according to examples of the present disclosure.

4B is the image of FIG. 4A rescaled to show the cutoff wavelengths of the comparative example CdSe glass and the glass-ceramic samples heat treated according to various conditions.

4C is a graph of the transmittance versus wavelength for the image in FIG. 4A and comparative CuInSe and CuInS glass samples, zoomed in to show the cutoff wavelengths for comparative CdSe glass, glass-ceramic samples heat treated according to various conditions, and CuInSe and SuInS samples.

5 is an X-ray diffraction ("XRD") pattern of a heat-treated glass-ceramic according to at least one example of the present disclosure.

6A-6C are representative Raman spectra of glass-ceramic samples heat treated at 650° C. and 700° C. according to various conditions and a splat-quenched glass-ceramic sample according to examples of the present disclosure.

7A & 7B are Raman spectra of glass-ceramic samples heat treated at 650° C. and 700° C. and splat-quenched according to various conditions according to examples of the present disclosure.

8 is a graph of residual stress versus substrate depth for two glass-ceramic samples having compressive stress regions resulting from two representative ion exchange processing conditions, according to examples of the present disclosure.

FIG. 9 is a scanning electron microscope (SEM) micrograph of a glass-ceramic according to an exemplary embodiment.

10A and 10B are SEM and transmission electron microscope (TEM) images, respectively, of a glass ceramic according to another exemplary embodiment.

11A and 11B are SEM and TEM micrographs, respectively, of a glass ceramic according to another exemplary embodiment.

12A and 12B are transmission and absorption spectra collected at OD/mm for a 0.5 mm polished plate of composition 889FLZ in an as-fabricated unannealed state and a heat treated state (600°C for 1 h).

13A and 13B are transmission and absorption spectra collected at OD/mm for a 0.5 mm polished plate of composition 889FMB in an as-fabricated unannealed state and a heat treated state (700°C for 1 h).

14A and 14B are transmission and absorption spectra of a 0.5 mm polished plate of composition 889FMC collected at OD/mm in an as-fabricated unannealed state and after heat treatment (500° C. 1 h and 600° C. 1 h).

15A and 15B are transmission and absorption spectra collected at OD/mm for a 0.5 mm polished plate of composition 889FMD in an as-fabricated unannealed state and after heat treatment (500°C for 1 h and 600°C for 1 h).

16A and 16B are transmission and absorption spectra collected at OD/mm for a 0.5 mm polished plate of composition 889FME in an as-fabricated unannealed state and after heat treatment (600°C for 1 h and 700°C for 1 h).

17A and 17B are transmission and absorption spectra collected at OD/mm for a 0.5 mm polished plate of composition 889FMG in an as-fabricated unannealed state and after heat treatment (700°C for 1 h and 700°C for 2 h).

18A-18D are TEM micrographs at four different magnifications of titanium-containing crystals within a sample of heat-treated composition 889FMC heat-treated at 700°C for 1 hour.

19A is a TEM micrograph of titanium-containing crystals within a sample of heat-treated composition 889FMC heat-treated at 700° C. for 1 hour.

19B is an electron dispersion spectroscopy (EDS) elemental map of titanium in the TEM micrograph of FIG. 19A.

DETAILED DESCRIPTION

Before referring to the following detailed description and drawings that specifically set forth exemplary embodiments, it should be understood that the present technology is not limited to the details or methods described in the specific description or shown in the drawings. For example, it will be understood by those skilled in the art that the features and attributes associated with an embodiment shown in one of the drawings or described in text associated with one of the embodiments may be well applied to other embodiments shown in other drawings or described in other text.

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

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.

Those skilled in the art and those who utilize and use the present disclosure will make improvements to the present disclosure. Therefore, it is to be understood that the embodiments shown in the drawings and described above are for illustrative purposes only and are not intended to limit the scope of the present disclosure, which is defined by the appended claims and is interpreted to include the doctrine of equivalents according to the principles of patent law.

Those skilled in the art will appreciate that the construction of the disclosure and other components is not limited to any specific materials. Unless otherwise specified herein, other exemplary embodiments of the disclosure disclosed herein can be formed from a wide variety of materials.

For purposes of this disclosure, the term "connected" (in all its forms: connected, coupled, connected, etc.) generally means that two components are joined together (electrically or mechanically) directly or indirectly to each other. Such joining may naturally be static or naturally may be movable. Such joining may be achieved by the two components and any additional intermediate elements (electrically or mechanically) that are integrally formed as a single unitary piece with each other or with the two components. Unless otherwise specified, such joining may naturally be permanent or naturally may be removable or disengageable.

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 disclosure includes the specific value or endpoint referenced. Regardless of whether the numerical value or the endpoint of a range of this specification is stated as "about", the numerical value or the endpoint of the range is intended to include two embodiments: one modified by "about" and one not modified by "about". It will also be understood that the endpoint values of each range are meaningful when they are related to another endpoint value and when they are not related to another endpoint value.

As used herein, the terms "substantially," "substantially," and variations thereof are intended to mean that the described feature is equal or approximately the same as a value or description. For example, a "substantially planar" surface is intended to mean a planar or approximately planar surface. Additionally, "substantially" is intended to mean that two values are equal or approximately equal. In some embodiments, "substantially" can mean that values are within about 10% of each other, such as within about 5% of each other, or within about 2% of each other.

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

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.

Unless otherwise stated, all compositions are expressed as the mole percent (mol %) of the batch. It will be appreciated by those skilled in the art that various melt components (e.g., fluorine, alkali metals, boron, etc.) may be subjected to different volatility levels (e.g., as a function of vapor pressure, melting time and/or melting temperature) during the melting of the components. Thus, the term "about" associated with such components is intended to include a value within about 0.2 mol % compared to the composition of the just-batch provided herein when the final product is measured. In view of the foregoing, it is expected that the substantial composition equivalence between the final product and the batch composition.

For the purposes of this disclosure, the terms "bulk", "bulk composition" and/or "overall composition" are intended to include the overall composition of the entire article, which may be different from the "local composition" or "localized composition", where the "bulk" may be different from the bulk composition due to the formation of crystalline and/or ceramic phases.

Furthermore, as used herein, the terms "article," "glass article," "ceramic article," "glass-ceramic," "glass element," "glass-ceramic article," and "glass-ceramic article" may be used interchangeably and include in their broadest scope any object made in whole or in part of glass and/or glass-ceramic materials.

As used herein, "glass state" refers to the inorganic amorphous phase material in the articles of the present disclosure, which is a fusion product cooled to a rigid state without crystallization. As used herein, "glass-ceramic state" refers to the inorganic material in the articles of the present disclosure, which includes both the glass state and the "crystalline phase" and/or "crystalline precipitate" as described herein.

The unit of coefficient of thermal expansion (CTE) is 10 ⁻⁷ /° C. and refers to values measured over a temperature range of about 0° C. to about 300° C. unless otherwise specified.

As used herein, "transmission" and "transmittance" refer to external transmission or transmittance, taking into account absorption, scattering and reflection. In the transmission and transmittance values reported herein, Fresnel reflections are not excluded.

As used herein, in the present disclosure, "optical density units", "OD" and "OD units" are used interchangeably to refer to optical density units, which are generally understood to be a measure of the absorbance of a test material, as measured by a spectrometer, resulting in OD = -log (I/I0), where _I0 is the intensity of light incident on the sample, and I is the intensity of light transmitted through the sample. In addition, the terms "OD/mm" or "OD/cm" used in the present disclosure are standardized absorbance measurements, determined by dividing the optical density units (i.e., as measured by an optical spectrometer) by the sample thickness (e.g., in millimeters or centimeters). In addition, any optical density units referred to over a specific wavelength range (e.g., 3.3 OD/mm to 24.0 OD/mm in UV wavelengths of 280 nm to 380 nm) are given as an average of the optical density units over that particular wavelength range.

As used herein, the term "haze" means the percentage of transmitted light that is scattered outside an angular cone of approximately ±2.5° as measured in a sample having a transmission path of approximately 1 mm according to ASTM method D1003.

In addition, as used herein, the term "[component]-free [glass or glass-ceramic]" (e.g., cadmium-free and selenium-free glass-ceramic) means that the glass or glass-ceramic is completely free of or substantially free of (i.e., <500 ppm) the listed component(s) and is prepared without the listed component(s) being actively, intentionally or purposefully added or dosed into the glass or glass-ceramic.

When referring to the glass-ceramics and glass-ceramic materials and articles of the present disclosure, compressive stress and depth of compression ("DOC") are measured by using commercial instruments, such as the Scattered Light Polarizer SCALP220 and accompanying software version 5 manufactured by GlasStress, Ltd. (Tallinn, Estonia); or the FSM-6000 manufactured by Orihara Co., Ltd. (Tokyo, Japan), unless otherwise stated. Both of these instruments measure optical retardation, which must be converted to stress via the stress optical coefficient ("SOC") of the material being measured. Therefore, stress measurements rely on accurate measurement of the SOC, which is related to the birefringence of the glass. The SOC is then measured according to an improved version of Scheme C described in ASTM Standard C770-98 (2013) ("Improved Scheme C"), entitled "Standard Test Method for Measurement of Glass Stress-Optical Coefficient", the entire text of which is incorporated herein by reference. Improved Scheme C includes using a glass disc or a glass ceramic disc as a specimen with a thickness of 5 to 10 mm and a diameter of 12.7 mm. The disc is isotropic and uniform, and after core drilling, both sides are polished and parallel. Improved Scheme C also includes calculating _the maximum force Fmax to be applied to the disc. The force should be sufficient to produce a compressive stress of at least 20 MPa. _Fmax is calculated using the following equation:

_Fmax = 7.854*D*h

Where _Fmax is the maximum force (N), D is the diameter of the disc (mm), and h is the thickness of the optical path (mm). For each force application, the stress is calculated using the following equation:

σ(MPa)＝8F/(π*D*h)

Where F is the force (N), D is the diameter of the disk (mm), and h is the thickness of the light path (mm).

In addition, as used herein, the terms "sharp cut-off wavelength" and "cut-off wavelength" are used interchangeably and refer to a cut-off wavelength in the range of about 350nm to 800nm, wherein the glass ceramic has a significantly higher transmittance above the cut-off wavelength (λc) than below the cut-off wavelength (λc). The cut-off wavelength (λc) is the wavelength at the midpoint between the "absorption limit wavelength" and the "high transmittance limit wavelength" in a given spectrum of the glass ceramic. The "absorption limit wavelength" is defined as the wavelength at which the transmittance is 5%; and in the "high transmittance wavelength", it is defined as the wavelength at which the transmittance is 72%. It will be understood that the "sharp UV cut-off" as used herein can be the sharp cut-off wavelength of the cut-off wavelength described above that occurs in the ultraviolet band of the electromagnetic spectrum.

The articles of the present disclosure include glasses and/or glass ceramics having one or more compositions listed herein. The articles can be used in any number of applications. For example, in any number of optically related applications and/or aesthetic applications, the articles can be used as a form of substrate, element, lens, covering and/or other element.

Article is formed by batch composition, and is cast in glass state.Article can be annealed and/or heat-processed (for example, heat-treated) to form glass-ceramic state with multiple ceramics or crystalline particles subsequently.It will be appreciated that, depending on the casting technique adopted, article can be easily crystallized and become glass-ceramic (for example, be cast into glass-ceramic state basically) without additional heat treatment.In the example of heat-processed after forming, a part of article, most of article, basically all articles or all articles can be converted into glass-ceramic state from glass state.Thus, although may be described in conjunction with glass state and/or glass-ceramic state, when converting between glass state and glass-ceramic state, the body composition of article can remain substantially unchanged, although the local part of article has different compositions (that is, due to forming ceramic or crystalline precipitate caused).

According to various examples, _the article may include: _Al2O3 ; _SiO2 ; _B2O3 ; _WO3 ; _MO3 ; _R2O , wherein _R2O is one or more of _Li2O , Na2O, _K2O , _Rb2O , and _Cs2O ; RO, wherein RO is one or more of MgO, _CaO , SrO, BaO, and ZnO; and various dopants. It will be appreciated that various other components (e.g., F, As, Sb, Ti, P, Ce, _Eu , La, Cl, Br, etc.) do not depart from the teachings provided herein.

According to the first example, the article may include: SiO2 _from about 58.8 mol% to about 77.58 mol%, _{Al2O3 from} about 0.66 mol% to about 13.69 mol%, _{B2O3 from} about 4.42 mol% to about 27 mol%, _R2O from about 0 mol% to about 13.84 mol%, RO from about 0 mol% to about 0.98 mol%, _WO3 from about 1.0 mol% to about 13.24 mol%, and _SnO2 from about 0 mol% to about 0.4 mol%. Such examples of articles may generally relate to Examples 1-109 of Table 1.

According to a second example, the article may include: SiO2 _from about 65.43 mol% to about 66.7 mol%, _{Al2O3 from} about 9.6 mol% to about 9.98 mol%, _{B2O3 from} about 9.41 mol% to about 10.56 mol%, _R2O from about 6.47 mol% to about 9.51 mol%, RO from about 0.96 mol% to about 3.85 mol%, _WO3 from about 1.92 mol% to about 3.85 mol%, _MoO3 from about 0 mol% to about 1.92 mol%, and _SnO2 from about 0 mol% to about 0.1 mol%. Such examples of articles may generally relate to Examples 110-122 of Table 2.

According to a third example, the article may include: SiO2 _from about 60.15 mol% to about 67.29 mol%, _{Al2O3 from} about 9.0 mol% to about 13.96 mol%, _{B2O3 from} about 4.69 mol% to about 20 mol%, _R2O from about 2.99 mol% to about 12.15 mol%, RO from about 0.00 mol% to about 0.14 mol%, _WO3 from about 0 mol% to about 7.03 mol%, _MoO3 from about 0 mol% to about 8.18 mol%, _SnO2 from about 0.05 mol% to about 0.15 mol%, and _{V2O5 from} about 0 mol% to about 0.34 mol%. Such examples of articles may generally relate to Examples 123-157 of Table 3.

According to a fourth example, the article may include: SiO2 _from about 54.01 mol% to about 67.66 mol%, _{Al2O3 from} about 9.55 mol% to about 11.42 mol%, _{B2O3 from} about 9.36 mol% to about 15.34 mol%, _R2O from about 9.79 mol% to about 13.72 mol%, RO from about 0.00 mol% to about 0.22 mol%, _WO3 from about 1.74 mol% to about 4.48 mol%, _MoO3 from about 0 mol% to about 1.91 mol%, _SnO2 from about 0.0 mol% to about 0.21 mol%, _{V2O5 from} about 0 mol% to about 0.03 mol%, Ag from about 0 mol% to about 0.48 mol%, and Au from about 0 mol% to about 0.01 mol%. Such examples of articles may generally relate to Examples 158-311 of Table 4.

According to a fifth example, the article may include: SiO2 _from about 60.01 mol% to about 77.94 mol%, _{Al2O3 from} about 0.3 mol% to about 10.00 mol%, _{B2O3 from} about 10 mol% to about 20 mol%, _R2O from about 0.66 mol% to about 10 mol%, _WO3 from about 1.0 mol% to about 6.6 mol%, and _SnO2 from about 0.0 mol% to about 0.1 mol%. Such examples of articles may generally relate to Examples 312-328 of Table 5.

The article may have about 1 mol % to about 99 mol % SiO ₂ , or about 1 mol % to about 95 mol % SiO ₂ , or about 45 mol % to about 80 mol % SiO ₂ , or about 60 mol % to about 99 mol % SiO ₂ , or about 61 mol % to about 99 mol % SiO ₂ , or about 30 mol % to about 99 mol % SiO ₂ , or about 58 mol % to about 78 mol % SiO ₂ , or about 55 mol % to about 75 mol % SiO ₂ , or about 50 mol % to about 75 mol % SiO ₂ , or about 54 mol % to about 68 mol % SiO ₂ , or about 60 mol % to about 78 mol % SiO ₂ , or about 65 mol % to about 67 mol % SiO ₂ , or about 60 mol % to about 68 mol % SiO ₂ , or about 56 mol % to about 72 mol % SiO ₂ , or about 60 mol % to about 70 mol % SiO ₂ . It will be appreciated that any and all values and ranges between the above-recorded ranges for SiO ₂ are contemplated. SiO ₂ may act as a primary glass-forming oxide and affect the stability, resistance to devitrification, and/or viscosity of the article.

The article may comprise: about 0 mol% to about 50 mol _{% Al2O3} , or about 0.5 mol% to about ₂₀ mol% _Al2O3 , or about 0.5 mol% to about 15 mol% _{Al2O3 ,} or about 7 mol% to about 15 mol% _Al2O3 , or about 0.6 mol% to about 17 _mol % _Al2O3 , or about 0.6 mol% to about 14 mol _{% Al2O3} , or about 7 mol% to about 14 mol _{% Al2O3} , or about 9.5 mol% to about 10 mol% _{Al2O3 ,} or about 9 mol% to about 14 mol% _{Al2O3 ,} about 9.5 mol% to about 11.5 mol% _{Al2O3 ,} or about 0.3 mol% to about 10 mol _{% Al2O3} , or about 0.3 mol% to about _{15 mol} % _Al2O3 , or about 2 mol % to about 16 mol % Al ₂ O ₃ , or about 5 mol % to about 12 mol % Al ₂ O ₃ , or about 8 mol % to about 12 mol % Al ₂ O ₃ , or about 5 mol % to about 10 mol % Al ₂ O ₃ . It will be understood that any and all values and ranges between the above noted Al ₂ O ₃ ranges are contemplated. Al ₂ O ₃ can act as an adjustable network former and contribute to stable articles with low CTE, article rigidity, and facilitate melting and/or forming.

The article may contain WO ₃ and/or MoO _3. For example, WO ₃ plus MoO ₃ may be about 0.35 mol % to about 30 mol %. _MoO3 may be about 0 mol% and _WO3 from about 1.0 mol% to about 20 mol%, or _MoO3 may be about 0 mol% and _WO3 from about 1.0 mol% to about 14 mol%, or _MoO3 from about 0 mol% to about 8.2 mol% and _WO3 from about 0 mol% to about 16 mol%, or _MoO3 from about 0 mol% to about 8.2 mol% and _WO3 from about 0 mol% to about 9 mol%, or _MoO3 from about 1.9 mol% to about 12.1 mol% and _WO3 from about 1.7 mol% to about 12 mol%, or _MoO3 from about 0 mol% to about 8.2 mol% and _WO3 from about 0 mol% to about 7.1 mol%, or _MoO3 from about 1.9 mol% to about 12.1 mol% and _WO3 from about 1.7 mol% to about 4.5 mol%, or _MoO3 from about 0 mol% and _WO3 from about 1.0 mol% to about 7.0 mol%. For _MoO3 , the glass composition may have about 0.35 mol% to about 30 mol% _MoO3 , or about 1 mol% to about 30 mol% _MoO3 , or about 0.9 mol% to about 30 mol% _MoO3 , or about 0.9 mol% to about 20 mol% _MoO3 , or about 0 mol% to about 1.0 mol% _MoO3 , or about 0 mol% to about 0.2 mol% _MoO3 . For WO ₃ , the glass composition may have: about 0.35 mol % to about 30 mol % WO ₃ , or about 1 mol % to about 30 mol % WO ₃ , or about 1 mol % to about 17 mol % WO ₃ , or about 1.9 mol % to about 10 mol % WO ₃ , or about 0.35 mol % to about 1 mol % WO ₃ , or about 1.9 mol % to about 3.9 mol % WO ₃ , or about 2 mol % to about 15 mol % WO ₃ , or about 4 mol % to about 10 mol % of WO ₃ , or about 5 mol % to about 7 mol % WO ₃ . It will be understood that any and all values and ranges between the above-recorded ranges for WO ₃ and/or MoO ₃ are contemplated.

The article may contain from about 2 mol% to about 40 mol _{% B2O3} , or from about 4 mol% to about 40 mol% _{B2O3 , or} from about 4.0 mol% to about 35 mol% _B2O3 , or from about 4.0 mol% to about 27 mol% _B2O3 , or from about 5.0 _mol % to about ₂₅ mol% _B2O3 , or from about 9.4 mol% to about 10.6 mol% _B2O3 , or from about 5 mol% to about 20 mol% _{B2O3 , or} from about 4.6 mol% to about 20 mol% _B2O3 , or from about 9.3 mol% to about 15.5 mol% _B2O3 , or from about _{10 mol} % to about 20 mol _{% B2O3} , or from _about 10 mol% to about 25 mol% _B2O3 . It will be appreciated that any and all values and ranges between _the above noted _B2O3 ranges are contemplated. _B2O3 may be a glass-forming _oxide that serves to reduce CTE, density, and viscosity, making the article easier to melt and form at low temperatures.

The article may include at least one alkali metal oxide. The alkali metal oxide may be represented by the chemical formula R ₂ O, wherein R ₂ O is one or more of Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O, Cs ₂ O, and/or a combination thereof. The article may have an alkali oxide composition of about 0.1 mol% to about 50 mol% _R2O , or about 0 mol% to about 14 mol% _R2O , or about 3 mol% to about 14 mol% _R2O , or about 5 mol% to about 14 mol% _R2O , or about 6.4 mol% to about 9.6 mol% _R2O , or about 2.9 mol% to about 12.2 mol% _R2O , or about 9.7 mol% to about 12.8 mol% _R2O , or about 0.6 mol% to about 10 mol% _R2O , or about 0 mol% to about 15 mol% _R2O , or about 3 mol% to about 12 mol% _R2O , or about 7 mol% to about 10 mol% _R2O . It will be appreciated that any and all values and ranges between the above noted _R2O ranges are contemplated. Basic oxides (e.g., _Li2O , _Na2O , _K2O , _Rb2O , and _Cs2O ) may be incorporated into articles for a variety of reasons, including (i) to lower melting temperature, (ii) to increase formability, (iii) to allow chemical strengthening by ion exchange, and/or (iv) as a species that divides certain crystallites.

According to various examples, the range of _{R2O minus Al2O3} is about -35 mol% to about 7 mol%, or about -12 mol% to about 2.5 mol%, or about -6% to about 0.25%, or about -3.0 mol% to about 0 mol%. It will be understood that any and all values and ranges between _the above-recorded ranges of _R2O minus _Al2O3 are contemplated.

The article may include at least one alkaline earth oxide. The alkaline earth oxide may be represented by the chemical formula RO, wherein RO is one or more of MgO, CaO, SrO, BaO, and ZnO. The article may include RO in an amount of about 0.02 mol% to about 50 mol% RO, or about 0.01 mol% to about 5 mol% RO, or about 0.02 mol% to about 5 mol% RO, or about 0.05 mol% to about 10 mol% RO, or about 0.10 mol% to about 5 mol% RO, or about 0.15 mol% to about 5 mol% RO, or about 0.05 mol% to about 1 mol% RO, or about 0.5 mol% to about 4.5 mol% RO, or about 0 mol% to about 1 mol% RO, or about 0.96 mol% to about 3.9 mol% RO, or about 0.2 mol% to about 2 mol% RO, or about 0.01 mol% to about 0.5 mol% RO, or about 0.02 mol% to about 0.22 mol% RO. It will be appreciated that any and all values and ranges between the above noted RO ranges are contemplated. According to various examples, R ₂ O can be greater than RO. Furthermore, the article can be free of RO. Alkaline earth oxides (e.g., MgO, CaO, SrO, and BaO) and other divalent oxides (e.g., ZnO) can improve the melting behavior of the article and can also serve to increase the CTE, Young's modulus, and shear modulus of the article.

The article may contain about 0.01 mol% to about 5 mol% _SnO2 , or about 0.01 mol% to about 0.5 mol% _SnO2 , or about 0.05 mol% to about 0.5 mol% _SnO2 , or about 0.05 mol% to about ₂ mol% SnO2, or about 0.04 mol% to about 0.4 mol% _SnO2 , or about 0.01 mol% to about 0.4 mol% _SnO2 , or about 0.04 mol% to about 0.16 mol% _SnO2 , or about 0.01 mol% to about 0.21 mol% _SnO2 , or about 0 mol% to about 0.2 mol% _SnO2 , or about 0 mol% to about 0.1 mol% _SnO2 . It will be appreciated that any and all values and ranges between the above noted _SnO2 ranges are contemplated. The article may also contain a low concentration of _SnO2 as a fining agent (e.g., other fining agents may include _{CeO2 , As2O3 , Sb2O5} , ^Cl- or F- ^, etc.) to help eliminate gaseous inclusions during melting. Certain fining agents may also act as redox pairs, color centers, and or nucleate or intercalate species into crystallites formed in the article.

The composition of certain components of the article may depend on the presence and/or composition of other components. For example, if WO ₃ is about 1 mol % to about 30 mol %, the article also contains about 0.9 mol % or less of Fe ₂ O ₃ , or SiO ₂ is about 60 mol % to about 99 mol %. In another example, if WO ₃ is about 0.35 mol % to about 1 mol %, the article contains about 0.01 mol % to about 5.0 mol % SnO ₂ . In another example, if MoO ₃ is about 1 mol % to about 30 mol %, SiO ₂ is about 61 mol % to about 99 mol %, or Fe ₂ O ₃ is about 0.4 mol % or less and R ₂ O is greater than RO. In another example, if MoO ₃ is about 0.9 mol % to about 30 mol % and SiO ₂ is about 30 mol % to about 99 mol %, the article contains about 0.01 mol % to about 5 mol % SnO ₂ .

The article may be substantially free of cadmium and substantially free of selenium. According to various examples, the article may also include at least one dopant selected from the group consisting of Ti, V, Cr, Mn, Fe, Ni, Cu, Pb, Pd, Au, Cd, Se, Ta, Bi, Ag, Ce, Pr, Nd, and Er for adjusting UV, visible, color, and/or near infrared absorptivity. The dopant concentration in the article may be from about 0.0001 mol % to about 1.0 mol %. For example, the article may include at least one of the following: Ag is from about 0.01 mol % to about 0.48 mol %, Au is from about 0.01 mol % to about 0.13 mol %, V ₂ O ₅ is from about 0.01 mol % to about 0.03 mol %, Fe ₂ O ₃ is from about 0 mol % to about 0.2 mol %, Fe ₂ O ₃ is from about 0 mol % to about 0.2 mol %, and CuO is from about 0.01 mol % to about 0.48 mol %. According to another example, the article may include at least one of: Ag is about 0.01 mol% to about 0.75 mol%, _Au is about 0.01 mol% to about 0.5 mol%, _V2O5 is about 0.01 mol% to about 0.03 mol%, and CuO is about 0.01 mol% to about 0.75 mol%. The article may include about 0 mol% to about 5 mol% fluorine to soften the glass. The article may include about 0 mol% to about 5 mol% phosphorus to further adjust the physical properties of the article and adjust crystal growth. The article may include _Ga2O3 , _In2O3 and/or _GeO2 to further adjust the physical and optical properties (e.g., refractive _index ) of the article _. Trace impurities of about 0.001 mol % to about 0.5 mol % may be present to further adjust the absorbance in the ultraviolet, visible (e.g., 390 nm to about 700 nm), and near infrared (e.g., about 700 nm to about 2500 nm) and/or to render the article fluorescent: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Se, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Te, Ta, Re, Os, Ir, Pt, Au, Ti, Pb, Bi, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. In addition, small amounts _{of P2O5} may be added to certain compositions to further adjust the physical properties and viscosity of the article.

It will be understood that each of the compositions and composition ranges noted above for _SiO2 , _Al2O3 , _{WO3, MoO3 , WO3} plus _MoO3 , _B2O3 , _R2O , RO, _V2O5 , Ag, Au, CuO, _SnO2 , and dopants may be used for any other compositions and/ _or composition ranges of other components of the articles listed herein _.

As explained above, conventional forming of tungsten-containing, molybdenum-containing or mixed tungsten-containing molybdenum alkali glasses is hampered by the separation of melt components during the melting process. The separation of glass components during the melting process leads to perceived solubility limits of alkali tungstates in molten glass and perceived solubility limits of products cast from such melts. Generally speaking, when tungsten melts, molybdenum melts or mixed tungsten-molybdenum melts are even slightly overalkaline (e.g., R ₂ O-Al ₂ O ₃ = about 0.25 mol % or greater), molten borosilicate glasses simultaneously form glass and dense liquid second phases. Although the concentration of the alkali tungstate second phase can be reduced by thorough mixing, high temperature melting and the use of small batch sizes (about 1000 g), it cannot be completely eliminated, resulting in the formation of a harmful second crystalline phase. It is believed that the formation of this alkali tungstate phase occurs in the initial stage of melting, where tungsten and/or molybdenum oxides react with "free" or "unbound" alkali carbonates. Due to the high density of the alkali tungstate and/or alkali molybdate relative to the formed borosilicate glass, it rapidly separates and/or delaminates, pools at the bottom of the crucible, and is unable to rapidly dissolve in the glass due to the significant density difference. Simply reducing the _R2O component present in the melt may be undesirable because _R2O can provide beneficial properties to the glass composition.

The inventors of the present disclosure have discovered that a homogeneous single-phase W- or Mo-containing superalkaline melt can be obtained by using a "bound" alkaline substance. For the purposes of the present disclosure, a "bound" alkaline substance is an alkaline element that is bound to alumina, boron oxide, and/or silicon oxide, while a "free" or "unbound" alkaline substance is an alkaline carbonate, alkaline nitrate, and/or alkaline sulfate, wherein the alkaline substance is not bound to silicon oxide, boron oxide, and/or alumina. Exemplary bound alkaline substances may include: feldspar, nepheline, borax, spodumene, other sodium or potassium feldspar, alkaline aluminosilicates, alkaline silicates, and/or other naturally occurring or artificial alkaline substances and one or more aluminum, boron, and/or silicon atoms. By introducing the alkaline substance in a bound form, the alkaline substance may not react with W or Mo present in the melt to form a dense alkaline tungstate and/or alkaline molybdate liquid. Furthermore, this batch material variation allows for the melting of strongly superbasic compositions (e.g., _R2O - _Al2O3 = about 2.0 mol% or greater ₎ without forming any alkali tungstate and/or alkali molybdate secondary phases. This also allows for the variation of the melting temperature and mixing method and still produces a single-phase homogeneous glass. It will be appreciated that, since the alkali tungstate phase is not completely immiscible with the borosilicate glass, extended stirring can also allow for the mixing of the two phases to allow for the casting of a single-phase article.

Once the glass melt is poured and solidified to obtain a glassy product, the product can be annealed, heat treated, or otherwise thermally processed to form a crystalline phase in the product. Thus, the product can be converted from a glassy state to a glass-ceramic state. The crystalline phase in the glass-ceramic state can have various morphologies. According to various examples, the crystalline phase is formed as a plurality of precipitates in the heat-treated region of the product. Thus, the precipitate can have a generally crystalline structure.

As used herein, "crystalline phase" refers to an inorganic material in the article of the present disclosure, which is a solid composed of atoms, ions or molecules, which are arranged in a three-dimensional periodic pattern. In addition, unless otherwise stated, the following method is 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. Then, in the case where XRD is unsuccessful (for example, due to the size, quality and/or chemistry of the precipitate), Raman spectroscopy ("Raman") is used to detect the presence of crystalline precipitates. Optionally, a transmission electron microscope ("TEM") is used to visually verify or confirm in any other way the determination of the crystalline precipitate obtained by XRD and/or Raman techniques. In some cases, the mass and/or size of the precipitate may be low enough, so that visual verification of the proof of the precipitate is particularly difficult. Thus, XRD and Raman of larger material sampling amounts may advantageously have larger sample sizes to determine the presence of precipitates.

Crystalline precipitate can have roughly rod-shaped or needle-shaped morphology.Precipitate can have following longest length dimension: about 1nm to about 500nm, or about 1nm to about 400nm, or about 1nm to about 300nm, or about 1nm to about 250nm, or about 1nm to about 200nm, or about 1nm to about 100nm, or about 1nm to about 75nm, or about 1nm to about 50nm, or about 1nm to about 25nm, or about 1nm to about 20nm, or about 1nm to about 10nm.Electron microscope can be adopted to measure the size of precipitate.For the purpose of the present disclosure, term "electron microscope" means that the longest length of precipitate is first visually measured by scanning electron microscope, and if precipitate cannot be distinguished, transmission electron microscope is used next.Because crystalline precipitate may have rod-shaped or needle-shaped morphology usually, the width of precipitate can be about 2nm to about 30nm, or about 2nm to about 10nm, or about 2nm to about 7nm. It will be understood that the size and/or morphology of the precipitate can be uniform, substantially uniform or may vary. Generally speaking, the overaluminous composition of the product can produce a needle-shaped precipitate with a length of about 100nm to about 250nm and a width of about 5nm to about 30nm. The overalkaline composition of the product can produce a needle-shaped precipitate with a length of about 10nm to about 30nm and a width of about 2nm to about 7nm. The Ag-containing, Au-containing and/or Cu-containing examples of the product can produce a rod-shaped precipitate with a length of about 2nm to about 20nm and a width or diameter of about 2nm to about 10nm. The volume fraction of the crystalline phase in the product can be about 0.001% to about 20%, or about 0.001% to about 15%, or about 0.001% to about 10%, or about 0.001% to about 5%, or about 0.001% to about 1%.

The smaller size of the precipitate may be advantageous for reducing the amount of light scattered by the precipitate, resulting in high optical clarity of the glass article when in the glass-ceramic state. As explained in more detail below, the size and/or mass of the precipitate in the article may vary, so that different portions of the article may have different optical properties. For example, portions of the article where the precipitate is present may result in changes in the absorptivity, color, reflectivity and/or transmission, and refractive index of light compared to portions of the article where there is a different (e.g., size and/or mass) precipitate and/or where there is no precipitate.

The precipitate may include an oxide of tungsten and/or an oxide of molybdenum. The crystalline phase includes an oxide of at least one of the following (about 0.1 mol % to about 100 mol % of the crystalline phase): (i) W, (ii) Mo, (iii) V and alkali metal cations, and (iv) Ti and alkali metal cations. Without being limited by theory, it is believed that during the thermal processing (e.g., heat treatment) of the product, tungsten and/or molybdenum cations aggregate to form a crystalline precipitate, thereby transforming from a glass state to a glass-ceramic state. The molybdenum and/or tungsten present in the precipitate may be reduced or partially reduced. For example, the molybdenum and/or tungsten in the precipitate may have an oxidation state of 0 to about +6. According to various examples, the molybdenum and/or tungsten may have a +6 oxidation state. For example, the precipitate may have a chemical structure of approximately WO ₃ and/or MoO _3. However, there may also be a significant portion of tungsten and/or molybdenum in the +5 oxidation state, and the precipitate may be referred to as a non-stoichiometric tungsten suboxide, a non-stoichiometric molybdenum suboxide, a "molybdenum bronze" and/or a "tungsten bronze". One or more of the above alkali metals and/or dopants may be present in the precipitate to compensate for the +5 charge of W or Mo. Tungsten bronze and/or molybdenum bronze are a group of non-stoichiometric tungsten and/or molybdenum suboxides having a general chemical formula of M _x WO ₃ or M _x MoO ₃ , where M = 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 and/or U, and where 0 < x < 1. M _x WO ₃ and M _x MoO ₃ structures are considered to be solid-state defect structures, in which the holes (i.e., the holes and/or channels in the lattice) in the network of reduced WO ₃ or MoO ₃ are randomly occupied by M atoms, which dissociate into M ⁺ cations and free electrons. Depending on the concentration of "M", the material properties can range from metallic to semiconductor, enabling the tuning of various optical absorption and electrical properties. The more W or Mo 5+, the more M+ cations are needed to compensate and the larger the value of x.

Tungsten bronze is a non-stoichiometric compound of the general formula M _x WO ₃ , where M is a cationic dopant, such as some other metal, most commonly an alkali metal, and x is a variable less than 1. For the purpose of clarity, although referred to as 'bronze', these compounds are structurally or chemically unrelated to metallic bronze, which is an alloy of copper and tin. Tungsten bronze is a solid phase spectrum with homogeneity varying with x. Depending on the dopant M and the corresponding concentration x, the material properties of tungsten bronze can range from metal to semiconductor and exhibit adjustable optical absorption. The structure of these bronzes is a solid defect structure in which M' cations are inserted into pores or channels of a binary oxide matrix and decompose into M+ cations and free electrons.

For the purpose of clarity, _MxWO3 is a naming _convention for a complex system of non-stoichiometric or 'sub-stoichiometric' compounds, which have varying crystal structures, which may be hexagonal, tetragonal, cubic or pyrochlore, wherein M may be one or a combination of certain elements on the periodic table, wherein x varies from 0<x<1, wherein the oxidation state of the bronze-forming species (in this case, W) is a mixture of species in its highest oxidation state (W6 ⁺ ) and lower oxidation states (e.g., W5 ⁺ ), and wherein the number three ("3") in _WO3 indicates that the number of oxygen anions may be between 2 and _3. Thus, as an alternative, _MxWO3 may be expressed as _the chemical form _MxWOZ , wherein 0<x<1 and 2<z<3, or as _{MxWO3 -z} , wherein 0<x<1 and 0<z< ₁ . However, for the purpose of convenience, _MxWO3 is used for such non-stoichiometric crystals. Similarly, 'bronze' generally applies to ternary metal oxides of _the formula _M'xM " _yOz , where (i) M" is a transition metal, (ii) M" _yOz is its highest binary oxide, (iii) _M ' is some other metal, and (iv) x is a variable falling in the range 0<x<1.

A portion of the article, a majority of the article, substantially the entire article, or the entire article may be thermally processed to form a precipitate. Thermal processing techniques may include, but are not limited to, furnaces (e.g., heat treatment furnaces), microwaves, lasers, and/or other techniques for local and/or bulk heating of the article. When thermally processed, crystalline precipitates are internally nucleated in a homogeneous manner within the article, wherein the article is thermally processed from a glass state to a glass-ceramic state. Thus, in some examples, the article may include both a glass state and a glass-ceramic state. In examples where the article body is thermally processed (e.g., the entire article is placed in a furnace), precipitates may be uniformly formed throughout the article. In other words, starting from the outer surface of the article, precipitates may be present throughout the entire body of the article (i.e., more than about 10 μm from the surface). In examples where the article is locally thermally processed (e.g., by laser), precipitates may only be present where the thermal processing reaches a sufficient temperature (e.g., at the surface and into the body of the article near the heat source). It will be understood that the article may be subjected to more than one thermal processing to produce a precipitate. Additionally or alternatively, thermal processing may be employed to remove and/or modify precipitates that have already formed (eg, as a result of prior thermal processing). For example, thermal processing may result in decomposition of the precipitates.

According to various examples, the article can be optically transparent to the visible region of the electromagnetic spectrum (i.e., from about 400 nm to about 700 nm) for both the presence and absence of precipitates (i.e., in the portion in the glass state or glass-ceramic state). As used herein, the term "optically transparent" refers to having a transmittance greater than about 1% over a 1 mm path length over at least one 50 nm wide wavelength band of light ranging from about 400 nm to about 700 nm (e.g., in %/mm). In some examples, the article has a transmittance of about 5%/mm or more, about 10%/mm or more, about 15%/mm or more, about 20%/mm or more, about 25%/mm or more, about 30%/mm or more, about 40%/mm or more, about 50%/mm or more, about 60%/mm or more, about 70%/mm or more, about 80%/mm or more, and all lower limits between these values, for at least one 50 nm wide wavelength band of light in the visible spectral region.

According to various examples, based on the presence of the precipitate, without the use of additional coatings or films, the glass-ceramic state of the article absorbs light in the ultraviolet ("UV") region (i.e., wavelengths less than about 400 nm). In some practical modes, the glass-ceramic state of the article is characterized as having a transmittance of less than 10%/mm, less than 9%/mm, less than 8%/mm, less than 7%/mm, less than 6%/mm, less than 5%/mm, less than 4%/mm, less than 3%/mm, less than 2%/mm, and even less than 1%/mm for at least one 50 nm wide wavelength band of light in the UV spectral region (e.g., from about 200 nm to about 400 nm). In some examples, the glass-ceramic state absorbs or has an absorption of at least 90%/mm, at least 91%/mm, at least 92%/mm, at least 93%/mm, at least 94%/mm, at least 95%/mm, at least 96%/mm, at least 97%/mm, at least 98%/mm, or even at least 99%/mm for at least one 50 nm wide wavelength band of light in the UV spectral region. The glass-ceramic state can have a sharp UV cutoff wavelength of about 320 nm to about 420 nm. For example, the glass-ceramic state can have a sharp UV cutoff of about 320 nm, about 330 nm, about 340 nm, about 350 nm, about 360 nm, about 370 nm, about 380 nm, about 390 nm, about 400 nm, about 410 nm, about 420 nm, about 430 nm, or any value therebetween.

In some examples, the glass-ceramic state of the article has a transmittance of greater than about 5%/mm, greater than about 10%/mm, greater than about 15%/mm, greater than about 20%/mm, greater than about 25%/mm, greater than about 30%/mm, greater than about 40%/mm, greater than about 50%/mm, greater than about 60%/mm, greater than about 70%/mm, greater than about 80%/mm, greater than about 90%/mm, and greater than all lower limits between these values, for at least one 50 nm wide wavelength band of light in the infrared (NIR) spectral region (e.g., from about 700 nm to about 2700 nm). In other examples, the glass-ceramic state of the article has a transmittance of less than about 90%/mm, less than about 80%/mm, less than about 70%/mm, less than about 60%/mm, less than about 50%/mm, less than about 40%/mm, less than about 30%/mm, less than about 25%/mm, less than about 20%/mm, less than about 15%/mm, less than about 10%/mm, less than about 5%/mm, less than 4%/mm, less than 3%/mm, less than 2%/mm, less than 1%/mm, and even less than 0.1%/mm, as well as less than all upper limits between these values, for at least one 50 nm wide wavelength band of light in the NIR spectral region. In other examples, the glass-ceramic state of the article absorbs or has an absorption of at least 90%/mm, at least 91%/mm, at least 92%/mm, at least 93%/mm, at least 94%/mm, at least 95%/mm, at least 96%/mm, at least 97%/mm, at least 98%/mm, or at least 99%/mm, or even at least 99.9%/mm for at least one 50 nm wide wavelength band of light in the NIR spectral region.

Various examples of the present disclosure may provide various properties and advantages. It will be understood that although certain properties and advantages may be disclosed in conjunction with certain compositions, the various properties and advantages disclosed may also apply to other compositions.

For the compositions of Tables 1 and 5 below, articles made from the disclosed compositions can exhibit a low coefficient of thermal expansion ("CTE"). For example, over a temperature range of about 0°C to about 300°C, the article can have a coefficient of thermal expansion of about ^10x10-7 °C ^-1 to about ^60x10-7 °C ^-1 . Such a low CTE can allow the article to withstand large and rapid fluctuations in temperature, making such articles suitable for operation in harsh environments. For optical properties, the article can exhibit: a transmittance of less than 1% at about 368nm or shorter wavelengths, optical transparency in the visible light region (e.g., about 500nm to about 700nm), and strong attenuation (e.g., blocking) of NIR wavelengths (e.g., about 700nm to about 1700nm). Such articles may be advantageous over conventional NIR management solutions because the article does not employ a coating or film (e.g., which may be mechanically brittle or sensitive to UV light and moisture). Because the article is impermeable to oxygen, moisture, and ultraviolet wavelengths (i.e., due to its glass or glass-ceramic properties), the NIR absorbing precipitate can be protected from harsh environmental conditions (e.g., moisture, caustic acids, bases, and gases) and rapidly changing temperatures. In addition, the UV cutoff wavelength and refractive index change of the glass-ceramic state of the article can be adjusted by post-forming heat treatment. The glass-ceramic state of the article can exhibit a change in UV cutoff or refractive index as a result of its crystalline precipitate. The glass state of the article can have a refractive index of about 1.505 to about 1.508, while the glass-ceramic state of the article can have a refractive index of about 1.520 to about 1.522. Thermally adjustable UV cutoff and refractive index can achieve a variety of UV cutoff glass specifications with a can of glass by changing the post-forming thermal processing conditions of the article. The thermally adjusted refractive index can produce a large refractive index Δ( ^10-2 ). Because the heat treatment required to adjust UV absorbency is accomplished at high viscosities (eg, 10 ⁸ to 10 ¹² poise), the final article can be thermally processed without damaging the surface or causing deformation.

For the compositions of Tables 1 and 2, articles made from these compositions can provide a new class of non-toxic, cadmium- and selenium-free articles that exhibit optical extinction with sharp and adjustable cut-off wavelengths. Unlike Cd-free alternatives to CdSe filter glasses containing Se, these articles do not contain Resource and Recovery Act ("RCRA") metals or other hazardous agents. In addition, unlike Cd-free alternatives containing indium and or gallium, the articles can be composed of lower cost elements. For optical properties, articles made from these compositions can provide high transparency in the NIR (e.g., greater than about 90%) for out to 2.7 microns. In addition, the articles can exhibit sharp visible light cut-off wavelengths of about 320 nm to about 525 nm, which can be adjusted by thermal processing conditions (e.g., time and temperature) and by composition.

For the composition of Table 3, the products of these exemplary compositions can use molybdenum instead of tungsten, which may be advantageous because molybdenum is generally not as expensive as tungsten. In addition, the products made of these compositions can be heat-processed into a glass-ceramic state, which provides various optical properties. For example, for a thickness of about 0.5 mm, the transmittance of the products of such compositions can be: about 4% to about 30% in the visible spectrum (e.g., about 400nm to about 700nm), about 5% to about 15% in NIR (e.g., about 700nm to about 1500nm), about 1% or less in UV transmittance of about 370nm wavelength or about 5% or less in UV transmittance of 370nm to about 390nm wavelength. According to some examples, the mixed molybdenum-tungsten example of the product can absorb 92.3% of the solar spectrum. Such optical properties can be visually perceived as the color of the product. Similar to other compositions, optical properties are produced by the growth of precipitates, and thus, based on thermal processing, color can change on the product. This thermally variable color can be used to create color gradients within an article, such as creating a shaded edge or boarder in a windshield or sunroof of an article. Such features may be advantageous for eliminating glass frit baked onto conventional windshield and sunroof surfaces. This thermally adjustable color can be used to create gradient absorption on an article. In addition, articles produced from these compositions can be bleached and patterned by lasers (e.g., operating at 355nm, 810nm, and 10.6μm wavelengths). Upon exposure to lasers at these wavelengths, the exposed portion of the article will transform from a blue or gray color (e.g., due to the color of the precipitate) to a transparent water white or yellowish color due to thermal decomposition of the UV and NIR absorbing precipitate. Patterns can be created in the article by rastering the laser along the surface of the article to selectively bleach the desired areas. When the article is bleached, the resulting glass state is no longer absorptive to the NIR, so that the bleaching process is self-limiting (i.e., because the NIR absorbing precipitate has decomposed). Furthermore, selective laser exposure can not only produce patterns, but also produce variable UV & NIR absorbance on the article. According to other examples, the article can be ground to a sufficiently small size and functionalized for use as a photothermal susceptible agent for cancer treatment (i.e., due to its NIR absorbing optical properties).

For the compositions of Table 4, articles made from these compositions may be capable of being heat treated after forming (e.g., forming a glass-ceramic state) to simultaneously adjust optical absorbency and produce a wide range of colors from a single composition. In addition, such examples may be fusion-formable and/or ion-exchangeable. Conventional colored glass compositions using Ag, Au, and/or Cu typically rely on forming nano-scale metal precipitates to produce color. The inventors of the present disclosure have discovered that Ag ¹⁺ cations can be inserted into tungsten and molybdenum oxides to form silver tungsten bronze and/or silver molybdenum bronze, which can provide multi-color properties for the article. Unexpectedly, adding low concentrations of AgO or AgNO ₃ to the M _x WO ₃ or M _x MoO ₃ of the article composition can produce a variety of colors (e.g., red, orange, yellow, green, blue, various browns, and/or combinations thereof) by subjecting the article to heat treatment at different times and temperatures. It will be understood that Au and/or Cu can be used in a similar manner. The analysis confirmed that the color tunability is not the result of forming an ensemble of metal nanoparticles templated on a crystalline phase (e.g., M _x WO ₃ or M _x MoO ₃ ). Rather, it is believed that the color tunability in these multicolor articles originates from the change in the band gap energy of the doped tungsten and/or molybdenum oxide precipitates, from the concentrations of the alkali ions and Ag ¹⁺ , Au and/or Cu cations inserted into the precipitates to form pure alkali, pure metal and/or mixed alkali metals, tungsten and/or molybdenum bronzes of different stoichiometric ratios. The band gap energy of the precipitates varies due to their stoichiometry and is thus largely independent of the precipitate size and/or shape. Thus, a doped M _x WO ₃ or M _x MoO ₃ precipitate can maintain the same size and/or shape, but can still have many different colors depending on the identity of the dopant "M" and the concentration "x". Heat treatment of such articles can produce a nearly complete rainbow color in a single article. In addition, the color gradient can be stretched or compressed over some physical distances by applying a thermal gradient to the article. In other examples, the article can be subjected to laser patterning to locally adjust the color of the article. Such articles may be advantageous for producing colored sunglass lens blanks, mobile phone and/or tablet covers, and/or other products that may be composed of glass ceramics and may have aesthetic colors. Since the precipitate is located in the glass ceramic, the scratch resistance and environmental durability are higher than the case where conventional metal color layers and polymer color layers are applied to provide color. Since the color of the article can be changed based on heat treatment, a can of glass melt can be used to continuously produce blanks, which can be heat treated to have a specific color indicated by consumer demand. In addition, articles made from these glass compositions can absorb UV and/or IR radiation, similar to other compositions disclosed herein.

According to various examples of the present disclosure, the article can be suitable for various fusion forming processes. For example, various compositions of the present disclosure can be used for a single fusion laminate or a double fusion laminate, wherein transparent tungsten, molybdenum, mixed tungsten molybdenum and/or titanium glass are used as a coating material around a substrate to form a laminated article. After being applied as a coating, the coating in the glass state can be converted into a glass-ceramic state. The glass-ceramic state coating of the fusion laminate can have a thickness of about 50 μm to about 200 μm and can have strong UV and IR attenuation and high average visible light transmittance (e.g., about 75% to about 85% for automotive windshields and/or architectural glazing), strong UV and IR attenuation and low visible light transmittance (e.g., about 5% to about 30% for automotive sidelights, automotive roof panels and privacy glazing), and/or a laminate that can adjust visible light and infrared absorbance by processing in a gradient furnace, local heating and/or localized bleaching. Furthermore, using the composition as an overlay to form an article provides a new process to fully achieve the goal of tunable optical properties while producing a strengthened monolithic glass sheet.

According to various examples, articles produced from the compositions of the present disclosure can be powdered or granulated and added to various materials. For example, the powdered articles can be added to coatings, adhesives, polymeric materials (e.g., polyvinyl butyral), sol-gels, and/or combinations thereof. Such features may be advantageous for imparting one or more properties of the articles to the materials described above.

According to various examples, the article may include TiO _2. The article may include TiO ₂ at a concentration of about 0.25 mol%, or about 0.50 mol%, or about 0.75 mol%, or about 1.0 mol%, or about 2.0 mol%, or about 3.0 mol%, or about 4.0 mol%, or about 5.0 mol%, or about 6.0 mol%, or about 7.0 mol%, or about 8.0 mol%, or about 9.0 mol%, or about 10.0 mol%, or about 11.0 mol%, or about 12.0 mol%, or about 13.0 mol%, or about 14.0 mol%, or about 15.0 mol%. mol%, or about 16.0 mol%, or about 17.0 mol%, or about 18.0 mol%, or about 19.0 mol%, or about 20.0 mol%, or about 21.0 mol%, or about 22.0 mol%, or about 23.0 mol%, or about 24.0 mol%, or about 25.0 mol%, or about 26.0 mol%, or about 27.0 mol%, or about 28.0 mol%, or about 29.0 mol%, or about 30.0 mol%, or any and all values and ranges therebetween. For example, the article can contain _TiO2 at a concentration of about 0.25 mol% to about 30 mol%, or about 1 mol% to about 30 mol% _TiO2 , or about 1.0 mol% to about 15 mol% _TiO2 , or about 2.0 mol% to about 15 mol% _TiO2 , or about 2.0 mol% to about 15.0 mol% _TiO2 . It will be understood that any and all values and ranges between the above-recorded _TiO2 ranges are contemplated.

According to various examples, the article may include one or more metal sulfides. For example, the metal sulfides may include MgS, _Na2S and/or ZnS. According to various examples, the article may include one or more metal sulfides. For example, the metal sulfides may include MgS, _Na2S and/or ZnS. The article may include the metal sulfide at a concentration of about 0.25 mol%, or about 0.50 mol%, or about 0.75 mol%, or about 1.0 mol%, or about 2.0 mol%, or about 3.0 mol%, or about 4.0 mol%, or about 5.0 mol%, or about 6.0 mol%, or about 7.0 mol%, or about 8.0 mol%, or about 9.0 mol%, or about 10.0 mol%, or about 11.0 mol%, or about 12.0 mol%, or about 13.0 mol%, or about 14.0 mol%. %, or about 15.0 mol%, or about 16.0 mol%, or about 17.0 mol%, or about 18.0 mol%, or about 19.0 mol%, or about 20.0 mol%, or about 21.0 mol%, or about 22.0 mol%, or about 23.0 mol%, or about 24.0 mol%, or about 25.0 mol%, or about 26.0 mol%, or about 27.0 mol%, or about 28.0 mol%, or about 29.0 mol%, or about 30.0 mol%, or any and all values and ranges therebetween. For example, the article may contain the metal sulfide at a concentration of about 0.25 mol% to about 30 mol%, or about 1.0 mol% to about 15 mol%, or about 1.5 mol% to about 5 mol%.

Similar to the oxides of tungsten and molybdenum described above, examples of products containing titanium can also produce crystalline phases, which include precipitates of titanium oxides. Crystalline phases include oxides of Ti and alkali metal cations (crystalline phases of about 0.1 mol % to about 100 mol %). Without being limited to theory, it is believed that during the thermal processing (e.g., heat treatment) of the product, titanium cations gather to form crystalline precipitates close to metal sulfides and or on metal sulfides, thereby changing from a glass state to a glass-ceramic state. Metal sulfides can play a dual role, playing the role of nucleating agents (i.e., because metal sulfides can have a higher melting temperature than the melt so as to serve as a crystal seed on which titanium can be gathered) and playing the role of reducing agents (i.e., metal sulfides are high reducing agents and can thus reduce the gathered titanium to 3+ states). Thus, due to metal sulfides, the titanium present in the precipitate can be reduced or partially reduced. For example, the titanium in the precipitate can have an oxidation state of 0 to about +4. For example, the precipitate can have a chemical structure of approximately _TiO2 . However, there may also be a significant portion of titanium in the +3 oxidation state, and in some cases these Ti ³⁺ cations may be charge stabilized by species inserted into channels in the titanium oxide lattice, forming compounds known as non-stoichiometric titanium suboxides, "titanium bronzes" or "bronze-type" titanium crystals. One or more of the above-mentioned alkali metals and/or dopants may be present in the precipitate to compensate for the +3 charge of Ti. Titanium bronzes are a group of non-stoichiometric titanium suboxides having the general chemical formula of M _x TiO ₂ , where M = one or more dopant cations 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, V, Cr, Mn, Fe, Ni, Cu, Pd, Se, Ta, Bi and Ce, and where 0 < x < 1. The M _x TiO ₂ structure is considered to be a solid-state defect structure, in which the holes (i.e., the vacancies or channels in the lattice) in the network of reduced TiO ₂ are randomly occupied by M atoms, which dissociate into M ⁺ cations and free electrons. Depending on the concentration of "M", the material properties can range from metallic to semiconductor, thereby enabling the tuning of various optical absorption and electrical properties. The more Ti3+, the more M+ cations are needed to compensate and the larger the value of x.

Consistent with the above disclosure, titanium bronzes are non-stoichiometric compounds of _the general formula _MxTiO2 , where M is a cationic dopant, such as some other metal, most commonly an alkali metal, and x is a variable less than 1. For purposes of clarity, although referred to as 'brons', these compounds are structurally or chemically unrelated to metallic bronze, which is an alloy of copper and tin. Titanium bronzes are solid phase spectra whose homogeneity varies with x. Depending on the dopant M and the corresponding concentration x, the material properties of titanium bronzes can range from metallic to semiconductor and exhibit tunable optical absorption. The structures of these bronzes are solid state defect structures in which M' dopant cations are inserted into (i.e., occupy) pores or channels of a binary oxide matrix and decompose into M+ cations and free electrons.

For the purpose of clarity, _MxTiO2 is a naming _convention for a complex system of non-stoichiometric or 'sub-stoichiometric' compounds with varying crystal structures, which may be monoclinic, hexagonal, tetragonal, cubic or pyrochlore, wherein M may be one or a combination of certain elements on the periodic table, wherein x varies from 0<x<1, wherein the oxidation state of the bronze-forming species (in this case, Ti) is a mixture of species in its highest oxidation state (Ti4 ⁺ ) and lower oxidation states (e.g., Ti3 ⁺ ), and wherein the number two ("2") in _TiO2 indicates that the number of oxygen anions may be between 1 and 2. Thus, _MxTiO2 may alternatively be expressed as _the chemical form _{MxTiO2Z ,} wherein 0<x<1 and 1<z<2, or as _{MxTiO2 -z} , wherein 0<x<1 and 0<z< ₁ . However, for the purpose of convenience, _MxTiO2 is used for such non-stoichiometric crystals. Similarly, 'bronze' generally applies to ternary metal oxides of _the formula _M'xM " _yOz , where (i) M" is a transition metal, (ii) M" _yOz is its highest binary oxide, (iii) _M ' is some other metal, and (iv) x is a variable falling in the range 0<x<1.

According to various examples, the glass-ceramic article containing titanium can be substantially free of W, Mo and rare earth elements. As described above, the ability of titanium to form its own suboxides can eliminate the need for tungsten and molybdenum, and the suboxides of titanium can eliminate the need for rare earth elements.

According to various examples, the glass-ceramic article can have a low concentration of iron or can be iron-free. For example, the article can include about 1 mol % or less Fe, or about 0.5 mol % or less Fe, or about 0.1 mol % or less Fe, or 0.0 mol % Fe, or any and all values and ranges therebetween.

According to various examples, the glass-ceramic article can have a low concentration of lithium or can be lithium-free. For example, the article can contain about 1 mol % or less of Li, or about 0.5 mol % or less of Li, or about 0.1 mol % or less of Li, or 0.0 mol % Li, or any and all values and ranges therebetween.

According to various examples, the glass-ceramic article can have a low concentration of zirconium or can be free of zirconium. For example, the article can contain about 1 mol % or less Zr, or about 0.5 mol % or less Zr, or about 0.1 mol % or less Zr, or 0.0 mol % Zr, or any and all values and ranges therebetween.

Similar to the formation of tungsten- or molybdenum-containing articles, titanium-containing articles can be formed by a method including the following steps: melting components containing silicon dioxide and titanium together to form a glass melt; allowing the glass melt to solidify to form glass; and precipitating bronze-type crystals containing titanium in the glass to form a glass ceramic. According to various examples, the precipitation of bronze-type crystals can be performed by one or more heat treatments. For titanium bronze-type crystals, the temperature at which the heat treatment is performed can be about 400°C to about 900°C, or about 450°C to about 850°C, or about 500°C to about 800°C, or about 500°C to about 750°C, or about 500°C to about 700°C, or any and all values and ranges therebetween. In other words, the precipitation of bronze-type crystals is performed at a temperature of about 450°C to about 850°C, or the precipitation of bronze-type crystals is performed at a temperature of about 500°C to about 700°C. The heat treatment may be carried out for a period of time of about 15 minutes to about 240 minutes, or about 15 minutes to about 180 minutes, or about 15 minutes to about 120 minutes, or about 15 minutes, or about 90 minutes, or about 30 minutes to about 90 minutes, or about 60 minutes to about 90 minutes, or any and all values and ranges therebetween. In other words, the precipitation of bronze-type crystals is carried out for a period of time of about 15 minutes to about 240 minutes, or the precipitation of bronze-type crystals is carried out for a period of time of about 60 minutes to about 90 minutes. The heat treatment may be carried out in ambient air, in an inert atmosphere, or in a vacuum.

The formation of titanium suboxides in titanium-containing examples of the article can result in different absorptivity and transmittance in different light wavelength bands. In the ultraviolet (UV) band of light (e.g., about 200nm to about 400nm), before the precipitation of titanium suboxides, the article in the glass state can have an average UV transmittance of about 18% to about 30%. For example, the average UV transmittance of the article in the glass state can be about 18%, or about 19%, or about 20%, or about 21%, or about 22%, or about 23%, or about 24%, or about 25%, or about 26%, or about 27%, or about 28%, or about 29%, or about 30%, or any and all values and ranges therebetween. After the formation or precipitation of titanium suboxides, the article in the glass-ceramic state can have an average UV transmittance of about 0.4% to about 18%. For example, the average UV transmittance of the article in the glass-ceramic state can be about 0.4%, or about 0.5%, or about 1%, or about 2%, or about 3%, or about 4%, or about 5%, or about 6%, or about 7%, or about 8%, or about 9%, or about 10%, or about 11%, or about 12%, or about 13%, or about 14%, or about 15%, or about 16%, or about 17%, or about 18%, or any and all values and ranges therebetween. It will be understood that the transmittance values described above can exist in articles having a thickness or optical path length of about 0.4 mm to about 1.25 mm.

In the visible band of light (e.g., about 400 nm to about 750 nm), before precipitation of titanium suboxides, the article in the glass state can have an average visible light transmittance of about 60% to about 85%. For example, the average visible light transmittance of the article in the glass state can be about 60%, or about 61%, or about 62%, or about 63%, or about 64%, or about 65%, or about 66%, or about 67%, or about 68%, or about 69%, or about 70%, or about 71%, or about 72%, or about 73%, or about 74%, or about 75%, or about 76%, or about 77%, or about 78%, or about 79%, or about 80%, or about 81%, or about 82%, or about 83%, or about 84%, or about 85%, or any and all values and ranges therebetween. After formation or precipitation of titanium suboxides, the article in the glass-ceramic state can have an average visible light transmittance of about 4% to about 85%. For example, the average UV transmittance of the article in the glass-ceramic state can be about 4%, or about 5%, or about 10%, or about 20%, or about 30%, or about 40%, or about 50%, or about 60%, or about 70%, or about 80%, or about 85%, or any and all values and ranges therebetween. It will be understood that the transmittance values described above can exist in articles having a thickness or optical path length of about 0.4 mm to about 1.25 mm.

In the near infrared (NIR) band of light (e.g., about 750 nm to about 1500 nm), before precipitation of titanium suboxides, the article in the glass state can have an average NIR transmittance of about 80% to about 90%. For example, the average NIR transmittance of the article in the glass state can be about 80%, or about 81%, or about 82%, or about 83%, or about 84%, or about 85%, or about 86%, or about 87%, or about 88%, or about 89%, or about 90%, or any and all values and ranges therebetween. After formation or precipitation of titanium suboxides, the article in the glass-ceramic state can have an average NIR transmittance of about 0.1% to about 10%. For example, the average UV transmittance of the article in the glass-ceramic state can be about 1%, or about 2%, or about 3%, or about 4%, or about 5%, or about 6%, or about 7%, or about 8%, or about 9%, or about 10%, or any and all values and ranges therebetween. It will be appreciated that the transmittance values described above may be present in articles having a thickness or optical path length of from about 0.4 mm to about 1.25 mm.

In the NIR band of light, the article in a glass state without low-valent oxides of titanium can have an average optical density per mm (i.e., first near-infrared absorptivity) of about 0.4 or less, or about 0.35 or less, or about 0.3 or less, or about 0.25 or less, or about 0.2 or less, or about 0.15 or less, or about 0.1 or less, or about 0.05 or less, or any and all values and ranges therebetween. After precipitation of the titanium suboxide, the article in the glass-ceramic state having the titanium suboxide can have an optical density per mm (i.e., a second near-infrared absorptivity) of about 6.0 or less, or about 5.5 or less, or about 5.0 or less, or about 4.5 or less, or about 4.0 or less, or about 3.5 or less, or about 3.0 or less, or about 2.5 or less, or about 2.0 or less, or about 2.0 or less, or about 1.5 or less, or about 1.0 or less, or about 0.5 or less, or any and all values and ranges therebetween. Thus, in some cases, the ratio of the second average near-infrared absorptivity to the first average near-infrared absorptivity can be about 1.5 or greater, or about 2.0 or greater, or about 2.5 or greater, or about 3.0 or greater, or about 5.0 or greater, or about 10.1 or greater. In such examples, the average optical density per mm of visible light wavelengths of the article in the glass-ceramic state having titanium suboxides may be 1.69 or less.

According to various examples, the article can exhibit low haze. For example, the article can exhibit a haze of about 20% or less, or about 15% or less, or about 12% or less, or about 11% or less, or about 10.5% or less, or about 10% or less, or about 9.5% or less, or about 9% or less, or about 8.5% or less, or about 8% or less, or about 7.5% or less, or about 7% or less, or about 6.5% or less, or about 6% or less, or about 5.5% or less. Less, or about 5% or less, or about 4.5% or less, or about 4% or less, or about 3.5% or less, or about 3% or less, or about 2.5% or less, or about 2% or less, or about 1.5% or less, or about 1% or less, or about 0.5% or less, or about 0.4% or less, or about 0.3% or less, or about 0.2% or less, or about 0.1% or less, or any and all values and ranges therebetween. The haze of the article is measured on a 1 mm thick sample and according to the protocol described above for haze measurement. According to various examples, the haze of the article can be lower than conventional glass ceramics due to the absence of β-quartz (i.e., virgilite), which is common in some glass ceramics but tends to increase haze. In other words, the glass ceramic article can be free of β-quartz crystalline phase. Additionally, the haze of the article may be due to a small amount or absence of large crystallites (eg, about <100 nm, or about <60 nm, or about <40 nm), which tend to scatter light.

The use of articles comprising titanium suboxides, crystals having the general formula _{MXTiO2 ,} or non-stoichiometric titanium bronzes may provide a number of advantages.

First, the thermal processing time to produce titanium suboxides can be shorter than that of other glass-ceramics. In addition, the thermal processing temperature can be lower than the softening point of the product. Such features may be beneficial for reducing manufacturing complexity and cost.

Second, color packages (e.g., _TiO2 + ZnS) can be introduced into a wide range of melt compositions, including those with ion exchangeable capabilities. In addition, such color packages may have less impact on chemical durability and other relevant properties of the article due to the lower concentration of color packages required.

Third, the use of titanium suboxide-containing glass-ceramics can provide fusion-formable and chemically strengthened materials for UV and/or IR blocking materials that may not have melting difficulties due to radiation capture. For example, for articles containing titanium suboxides, when melted or in a just-cast state (i.e., a green state before heat treatment), they are highly transparent in visible and NIR wavelengths, which is different from Fe2 ⁺ -doped glasses that still have strong absorption in the near infrared even when melted.

Example

The following examples represent non-limiting examples of compositions of the articles of the present disclosure.

Referring now to Table 1, the article may have: _SiO2 from about 58.8 mol% to about 77.58 mol%, _Al2O3 from about 0.66 mol% to about 13.69 mol%, _{B2O3 from} about 4.42 mol% to about 27 _mol %, _R2O from about 0 mol% to about 13.84 mol%, RO from about 0 mol% to about 0.98 mol%, _WO3 from about 1.0 mol% to about 13.24 mol%, and _SnO2 from about 0 mol% to about 0.4 mol%. It will be appreciated that any of the exemplary compositions of Table 1 may include: _MnO2 from about 0 mol% to about _0.2 mol%, _Fe2O3 from about 0 mol% to about 0.1 mol%, _TiO2 from about 0 mol% to about _0.01 mol%, _As2O5 from about 0 mol% to about 0.17 mol%, and/or _{Eu2O3 from} about 0 mol% to about 0.1 mol%. The compositions of Table 1 are provided in a freshly batched state in a crucible.

Table 1:

Referring now to Table 2, the article may have: _SiO2 from about 65.43 mol% to about 66.7 mol%, _{Al2O3 from} about 9.6 mol% to about 9.98 mol%, _{B2O3 from} about 9.41 mol% to about 10.56 mol%, _R2O from about 6.47 mol% to about 9.51 mol%, RO from about 0.96 mol% to about 3.85 mol%, _WO3 from about 1.92 mol% to about 3.85 mol%, _MoO3 from about 0 mol% to about 1.92 mol%, and _SnO2 from about 0 mol% to about 0.1 mol%. The composition of Table 2 is provided in a just-made state in a crucible.

Table 2

Referring now to Table 3, the article may have: _SiO2 from about 60.15 mol% to about 67.29 mol%, _Al2O3 from about 9.0 mol% to about 13.96 mol%, _{B2O3 from} about 4.69 mol% to about 20 _mol %, _R2O from about 2.99 mol% to about 12.15 mol%, RO from about 0.00 mol% to about 0.14 mol%, _WO3 from about 0 mol% to about 7.03 mol%, _MoO3 from about 0 mol% to about 8.18 mol%, _SnO2 from about 0.05 mol% to about 0.15 mol%, and _V2O5 from about 0 mol _% to about 0.34 mol%. It will be appreciated that any of the exemplary compositions of Table 3 may include _Fe2O3 from about 0 mol _% to about 0.0025 mol%. The compositions of Table 3 are provided in a just-batched state in a crucible.

Table 3

Referring now to Table 4, the article may have: _SiO2 from about 54.01 mol% to about 67.66 mol%, _Al2O3 from about 9.55 mol% to about 11.42 mol%, _{B2O3 from} about 9.36 mol% to about _15.34 mol%, _R2O from about 9.79 mol% to about 13.72 mol%, RO from about 0.00 mol% to about 0.22 mol%, _WO3 from about 1.74 mol% to about 4.48 mol%, _MoO3 from about 0 mol% to about 1.91 mol%, _SnO2 from about 0.0 mol% to about 0.21 mol%, _{V2O5 from} about 0 mol% to about 0.03 mol%, Ag from about 0 mol% to about 0.48 mol%, and Au from about 0 mol% to about 0.01 mol%. It will be appreciated that any exemplary composition of Table 4 may include: _CeO2 from about 0 mol% to about 0.19 mol%, CuO from about 0 mol% to about 0.48 mol%, Br from about 0 mol% to about 0.52 mol%, Cl from about 0 mol% to about 0.2 mol%, _TiO2 from about 0 mol% to about 0.96 mol%, and/or _Sb2O3 from about 0 mol% to about 0.29 mol%. The compositions of Table ₄ are provided in a freshly batched state in a crucible.

Table 4

Referring now to Table 5, the article may have: _SiO2 from about 60.01 mol% to about 77.94 mol%, _Al2O3 from about 0.3 mol% to about 10.00 mol%, _{B2O3 from} about 10 mol% to about 20 _mol %, _R2O from about 0.66 mol% to about 10 mol%, _WO3 from about 1.0 mol% to about 6.6 mol%, and _SnO2 from about 0.0 mol% to about 0.1 mol%. It will be appreciated that _any of the exemplary compositions of Table 5 may include _Sb2O3 from about 0 mol% to about 0.09 mol%. The compositions of Table 5 are provided in a freshly batched state in a crucible.

Table 5

Referring now to Table 6, a comparative example exemplary glass composition list is provided, which, when melted with unbound alkaline batch materials (e.g., alkaline carbonates) instead of bound alkaline substances (e.g., nepheline), forms a liquid alkaline tungstate separated during the melting process. As explained above, the second liquid alkaline tungstate phase may solidify as separate crystals, which may make the substrate made therefrom opalescent.

Table 6

Example Applications

For context, glasses containing cadmium and selenium ("CdSe glasses") can be characterized by their toxicity because they have appreciable amounts of cadmium and selenium. Some efforts have been made to develop non-toxic or low-toxic alternatives to CdSe glasses. For example, some conventional alternatives include glass compositions that do not contain Cd. However, these compositions still contain selenium and other expensive dopants, such as indium and gallium. In addition, conventional Cd-free selenium-containing glasses are characterized as having poor cutoff wavelength and/or viewing angle dependence relative to CdSe glasses. Therefore, the applicant believes that there is a need for cadmium-free and selenium-free materials that have comparable or improved optical properties relative to conventional CdSe glasses. Preferably, these materials have adjustable band gaps and sharp cutoffs as non-toxic alternatives to CdSe glasses. For the target applications of these materials, non-toxic CdSe glass alternatives are also needed to have the following characteristics: low coefficient of thermal expansion (CTE), durability, thermal stress resistance and/or relatively simple and low-cost manufacturing and processing requirements.

According to some aspects of the present disclosure, a glass-ceramic is provided that includes aluminoborosilicate glass; about 0.7 to about 15 mol % WO ₃ ; at least one alkali metal oxide, about 0.2 to about 15 mol %; and at least one alkaline earth metal oxide, about 0.1 to about 5 mol %.

According to some aspects of the present disclosure, a glass-ceramic is provided that includes aluminoborosilicate glass; about 0.7 to about 15 mol % of WO ₃ ; about 0.2 to about 15 mol % of at least one alkali metal oxide; and about 0.1 to about 5 mol % of at least one alkaline earth metal oxide. In addition, the glass-ceramic includes: an optical transmittance of at least 90% from 700 nm to 3000 nm, and a sharp cutoff wavelength of about 320 nm to about 525 nm.

According to other aspects of the present disclosure, a glass-ceramic is provided that includes aluminoborosilicate glass; about 0.7 to about 15 mol % of WO ₃ ; about 0.2 to about 15 mol % of at least one alkali metal oxide; and about 0.1 to about 5 mol % of at least one alkaline earth metal oxide. In addition, the glass-ceramic includes at least one of: alkaline earth, alkaline, and mixed alkaline earth-alkaline tungstate crystalline phases, which are in stoichiometric or non-stoichiometric form.

In some implementations of the aforementioned aspects of the glass-ceramic, the aluminoborosilicate glass comprises: _SiO2 about 55 to about 80 mol%, _Al2O3 about ₂ to about 20 mol%, and _B2O3 about ₅ to about 40 mol%, _SiO2 68 to 72 mol%, _{Al2O3 8} to 12 mol%, and _{B2O3 5} to 20 mol%. In addition, the at least one alkaline earth metal oxide may include MgO 0.1 to 5 mol%. The at least one alkali metal oxide may include _Na2O 5 to 15 mol%. In addition, the difference in the amount of the at least one alkali metal oxide _{and Al2O3} in the aluminoborosilicate glass may range from -6 mol% to +2 mol%.

In other implementations of the aforementioned aspects of the glass-ceramic, the glass-ceramic can be substantially free of cadmium and substantially free of selenium. In addition, the glass-ceramic can also include at least one dopant selected from the group consisting of F, P, S, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Sb, Te, and Bi. In other implementations of the aforementioned aspects of the glass-ceramic, the glass-ceramic can also include MoO ₃ , which is 0% to about 50% of the WO ₃ present in the glass-ceramic.

According to another aspect of the present disclosure, an article is provided comprising a substrate comprising a major surface and a glass-ceramic composition comprising: aluminoborosilicate glass; WO ₃ about 0.7 to about 15 mol%; at least one alkali metal oxide, about 0.2 to about 15 mol%; and at least one alkaline earth metal oxide, about 0.1 to about 5 mol%. In addition, in some practices of this aspect, the substrate further comprises a compressive stress region extending from the major surface to a first selected depth in the substrate and resulting from an ion exchange process. In addition, in some embodiments of this aspect, the substrate may include: an optical transmittance of at least 90% from 700 nm to 3000 nm, and a sharp cutoff wavelength of about 320 nm to about 525 nm.

According to another aspect of the present disclosure, a method for manufacturing a glass-ceramic is provided, comprising: mixing a batch material comprising aluminoborosilicate glass, about 0.7 to about 15 mol % of WO ₃ , about 0.2 to about 15 mol % of at least one alkali metal oxide, and about 0.1 to about 5 mol % of at least one alkaline earth metal oxide; melting the batch material at about 1500°C to about 1700°C to form a melt; annealing the melt at about 500°C to about 600°C to define an annealed melt; and heat treating the annealed melt at about 500°C to about 1000°C for about 5 minutes to about 48 hours to form a glass-ceramic.

In some practices of the aforementioned method for making glass ceramics, the heat treatment includes heat treating the annealed melt at about 600°C to about 800°C for about 5 minutes to about 24 hours to form the glass ceramic. In addition, the heat treatment includes heat treating the annealed melt at about 650°C to about 725°C for about 45 minutes to about 3 hours to form the glass ceramic. In some embodiments of the method, the glass ceramic may include: an optical transmittance of at least 90% from 700nm to 3000nm, and a sharp cutoff wavelength of about 320nm to about 525nm.

As described in detail in the present disclosure, provided cadmium-free and selenium-free glass-ceramic materials have comparable or improved optical properties compared to conventional CdSe glass. In embodiments, these materials have adjustable band gaps and sharp cutoffs as non-toxic alternatives to CdSe glass. Embodiments of these materials may also be characterized by low coefficient of thermal expansion (CTE), durability, thermal stress resistance, and/or relatively simple and low-cost manufacturing and processing requirements.

More generally, the glass-ceramic materials disclosed herein and articles containing them include a balance of aluminoborosilicate glass, tungsten oxide, at least one alkali metal oxide, and at least one alkaline earth metal oxide. These glass-ceramic materials can be characterized by an optical transmittance of at least 90% from 700nm to 3000nm, and a sharp cutoff wavelength of about 320nm to about 525nm. In addition, these materials can include, for example, at least one alkaline earth tungstate crystalline phase established by specific heat treatment conditions after forming the glass-ceramic. In addition, embodiments of these glass-ceramic materials are characterized in that the cutoff can be adjusted by selecting specific heat treatment conditions. Thus, these glass-ceramic materials provide non-toxic cadmium- and selenium-free glass-ceramics as a substitute for conventional CdSe glass.

Various embodiments of the glass-ceramic materials of the present disclosure may be used in the form of substrates, components, coverings, and other elements in any of the following applications: security and surveillance filters configured to suppress visible light for infrared illumination; airport runway lights; laser eyewear; gratings for motion control of motors; barcode readers; atomic force microscopes; nanoimprinters; laser interferometer metrology solutions; laser-based dynamic calibration systems; lithography solutions for integrated circuit manufacturing; photon bit error rate test solutions; photon digital communication analyzers; photon jitter generation and analysis systems; optical modulation analyzers; optical power meters; optical attenuators; light sources; light wave component analyzers; gas chromatographs; spectrometers; fluorescence microscopes; traffic monitoring cameras; environmental waste, water, and exhaust monitoring equipment; spectral filters for cameras; radiation thermometers; imaging brightness colorimeters; industrial image processing; controllable wavelength light sources for counterfeit detection; scanners for digitizing color images; astronomical filters; Humphrey field analyzers in medical diagnostic equipment; and filters for ultrashort pulse lasers. Embodiments of these glass-ceramic materials are also suitable for use in a variety of artistic endeavors and applications utilizing colored glass, glass-ceramics, and ceramics, such as by glassblowers, pyrotechnicians, stained glass artists, and the like.

Glass ceramic materials and the products containing them provide various advantages (including compared to CdSe glass) in the same field compared to conventional glass, glass ceramics and ceramic materials. As mentioned above, the glass ceramic materials of the present disclosure are free of cadmium and selenium, and provide sharp visible light extinction similar to the conventional CdSe filter glass of orange color simultaneously. The glass ceramic materials of the present disclosure also provide sharper visible light extinction compared to semiconductor-doped glass (conventional substitute of CdSe glass). In addition, compared to the conventional substitute of CdSe glass adopting indium, gallium and/or other high-cost metals and components, the glass ceramic materials of the present disclosure are prepared with lower cost materials. Another advantage of these glass ceramic materials is that they can be characterized as and can adjust the cut-off wavelength by selecting heat treatment temperature and time conditions. Another advantage of these glass ceramics is that they are transparent in near infrared (" NIR ") spectrum, and do not show transmittance decline (this is different from CdSe glass) at 900 to 1100nm wavelength. Furthermore, these glass-ceramic materials can be produced by conventional melt-quenching processes, unlike conventional CdSe glass substitutes (eg, semiconductor-doped glasses containing indium and gallium) that require additional semiconductor synthesis and milling steps.

Referring now to FIG. 1 , an article 100 is shown comprising a substrate 10 comprising a glass-ceramic composition according to the present disclosure. These articles can be used in any of the applications listed above (e.g., optical filters, airport runway lights, barcode readers, etc.). Thus, in some embodiments, the substrate 10 can be characterized by an optical transmittance of at least 90% from 700 nm to 3000 nm, and a sharp cutoff wavelength of about 320 nm to about 525 nm. The substrate 10 comprises a pair of opposing major surfaces 12, 14. In some embodiments of the article 100, the substrate 10 comprises a compressive stress region 50. As shown in FIG. 1 , the compressive stress region 50 of the article 110 is exemplary and extends from the major surface 12 to a first selected depth 52 within the substrate. Some embodiments of the article 100 (not shown) include a comparable additional compressive stress region 50 extending from the major surface 14 to a second selected depth (not shown). In addition, some embodiments of the article 100 (not shown) include a plurality of compressive stress regions 50 extending from the major surfaces 12, 14 of the substrate 10. In addition, some embodiments of the article 100 (not shown) include a plurality of compressive stress regions 50 extending from the respective major surfaces 12, 14, and compressive stress regions also extending from short edges (i.e., edges orthogonal to the major surfaces 12, 14) of the substrate 10. As will be appreciated by those skilled in the art of the present disclosure, various combinations of compressive stress regions 50 may be incorporated into the article 100, depending on the processing conditions used to produce these compressive stress regions 50 (e.g., fully immersing the substrate 10 in a molten salt ion exchange bath, partially immersing the substrate 10 in a molten salt ion exchange bath, fully immersing the substrate 10 while masking certain edges and/or surfaces, etc.).

As used herein, "selected depth" (e.g., selected depth 52), "depth of compression," and "DOC" may be used interchangeably to define the depth at which stress in a substrate 10 described herein changes from compression to tension. Depending on the ion exchange treatment, the DOC may be measured by a surface stress gauge (e.g., FSM-6000) or a scattered light polariscope (SCALP). When stress is induced in a substrate 10 having a glass or glass ceramic composition by exchanging potassium ions into a glass substrate, the DOC is measured using a surface stress gauge. When stress is induced in a glass article by exchanging sodium ions into a glass article, the DOC is measured using SCALP. When stress is induced in a substrate 10 having a glass or glass ceramic composition by exchanging both potassium and sodium ions into the glass, the DOC is measured by SCALP because it is believed that the depth of exchange of sodium represents the DOC, and the depth of exchange of potassium ions represents the change in the magnitude of the compressive stress (rather than the change in stress from compression to tension); in such glass substrates, the depth of exchange of potassium ions is measured by a surface stress gauge. Also as used herein, "maximum compressive stress" is defined as the maximum compressive stress within the compressive stress region 50 in the substrate 10. In some embodiments, the maximum compressive stress is achieved at or proximate to the one or more major surfaces 12, 14 defining the compressive stress region 50. In other embodiments, the maximum compressive stress is achieved between the one or more major surfaces 12, 14 and a selected depth 52 of the compressive stress region 50.

Referring again to FIG. 1 , the substrate 10 of the article 100 can be characterized by a glass-ceramic composition. In an embodiment, the glass-ceramic composition of the substrate 10 has: WO ₃ is 0.7 to 15 mol%, at least one alkali metal oxide is 0.2 to 15 mol%, at least one alkaline earth metal oxide is 0.1 to 5 mol%, and the balance is silicate-containing glass. These silicate-containing glasses include: aluminoborosilicate glass, borosilicate glass, aluminosilicate glass, soda-lime glass, and chemically strengthened versions of these silicate-containing glasses.

In addition, in the embodiment of the article 100 shown in Figure 1, the substrate 10 can have a selected length and width or diameter to define its surface area. The substrate 10 can have at least one edge defined by its length and width or defined by its diameter between the major surfaces 12, 14 of the substrate 10. The substrate 10 can also have a selected thickness. In some embodiments, the substrate has a thickness of about 0.2 mm to about 1.5 mm, about 0.2 mm to about 1.3 mm, and about 0.2 mm to about 1.0 mm. In other embodiments, the substrate has a thickness of about 0.1 mm to about 1.5 mm, about 0.1 mm to about 1.3 mm, or about 0.1 mm to about 1.0 mm.

In some embodiments of the article 100, as shown in the exemplary form of Figure 1, the substrate 10 is selected from a chemically strengthened aluminoborosilicate glass. For example, the substrate 10 can be selected from a chemically strengthened aluminoborosilicate glass having a compressive stress region 50 extending to a first selected depth 52 greater than 10 μm, having a maximum compressive stress greater than 150 MPa. In other embodiments, the substrate 10 is selected from a chemically strengthened aluminoborosilicate glass having a compressive stress region 50 extending to a first selected depth 52 greater than 25 μm, having a maximum compressive stress greater than 400 MPa. The substrate 10 of the article 100 may also include one or more compressive stress regions 50 extending from one or more of the major surfaces 12, 14 to a selected depth 52 (or depths) with a maximum compressive stress of greater than about 150 MPa, greater than 200 MPa, greater than 250 MPa, greater than 300 MPa, greater than 350 MPa, greater than 400 MPa, greater than 450 MPa, greater than 500 MPa, greater than 550 MPa, greater than 600 MPa, greater than 650 MPa, greater than 700 MPa, greater than 750 MPa, greater than 800 MPa, greater than 850 MPa, greater than 900 MPa, greater than 950 MPa, greater than 1000 MPa, and all maximum compressive stress levels between these values. In some embodiments, the maximum compressive stress is 2000 MPa or less. Additionally, the depth of compression (DOC) or first selected depth 52 can be set to 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, and to even higher depths, depending on the thickness of the substrate 10 and the processing conditions associated with generating the compressive stress region 50. In some embodiments, the DOC is less than or equal to 0.3 times the thickness (t) of the substrate 10, for example, 0.3t, 0.28t, 0.26t, 0.25t, 0.24t, 0.23t, 0.22t, 0.21t, 0.20t, 0.19t, 0.18t, 0.15t, or 0.1t.

As described above, the glass-ceramic material of the present disclosure (including the substrate 10 for the article 100, see FIG. 1) is characterized by the following glass-ceramic composition: WO ₃ 0.7 to 15 mol%; at least one alkali metal oxide 0.2 to 15 mol%; at least one alkaline earth metal oxide 0.1 to 5 mol%; and the balance silicate-containing glass, such as aluminoborosilicate glass. In an embodiment, the glass-ceramic material may be characterized by: an optical transmittance of at least 90% from 700 nm to 3000 nm, and a sharp cutoff wavelength of about 320 nm to about 525 nm. In some practical modes, the glass-ceramic material may also be characterized by the presence of at least one alkaline earth tungstate crystalline phase and/or at least one alkali metal tungstate crystalline phase. For example, the alkaline earth tungstate crystalline phase may be M _x WO ₃ , wherein M is at least one of Be, Mg, Ca, Sr, Ba, and Ra, and wherein 0<x<1. In an embodiment of the glass-ceramic of the present disclosure, the at least one alkaline earth tungstate crystalline phase is one or two of the following: MgWO ₄ crystalline phase (see, e.g., FIG. 5 and its corresponding description) and MgW ₂ O ₇ crystalline phase (see, e.g., FIG. 6A-6C, 7A & 7B and their corresponding descriptions). For another example, the alkaline tungstate crystalline phase may be M _x WO ₃ , wherein M is at least one of Li, Na, K, Cs, Rb, and wherein 0<x<1. For another example, the tungstate crystalline phase may be M _x WO ₃ , wherein M is a combination of an alkaline earth substance selected from Be, Mg, Ca, Sr, Ba and Ra and an alkali metal selected from Li, Na, K, Cs, Rb, and wherein 0<x<1.

In an embodiment, the glass ceramic of the present disclosure is optically transparent in the visible light region of the spectrum (i.e., about 400nm to about 700nm). As used herein, the term "optically transparent" refers to having a transmittance greater than about 1% (e.g., in %/mm) over a 1mm path length over at least one 50nm wide wavelength band of light in the range of about 400nm to about 700nm. In some embodiments, for at least one 50nm wide wavelength band of light in the visible spectrum region, the glass ceramic has the following transmittance: at least greater than about 5%/mm, greater than about 10%/mm, greater than about 15%/mm, greater than about 20%/mm, greater than about 25%/mm, greater than about 30%/mm, greater than about 40%/mm, greater than about 50%/mm, greater than about 60%/mm, greater than about 70%/mm, and greater than all lower limits between these values.

Embodiments of the glass-ceramics of the present disclosure absorb light in the ultraviolet ("UV") region (i.e., wavelengths less than about 370 nm) and/or near infrared ("NIR") region (i.e., wavelengths from about 700 nm to about 1700 nm) of the spectrum without the use of additional coatings or films. In some practical embodiments, the glass-ceramics are characterized as having a transmittance of less than 10%/mm, less than 9%/mm, less than 8%/mm, less than 7%/mm, less than 6%/mm, less than 5%/mm, less than 4%/mm, less than 3%/mm, less than 2%/mm, and even less than 1%/mm for at least one 50 nm wide wavelength band of light in the UV spectral region. In some embodiments, the glass-ceramic absorbs or has an absorption of at least 90%/mm, at least 91%/mm, at least 92%/mm, at least 93%/mm, at least 94%/mm, at least 95%/mm, at least 96%/mm, at least 97%/mm, at least 98%/mm, or even at least 99%/mm for at least one 50 nm wide wavelength band of light in the UV spectral region. In other practical modes, the glass-ceramic is characterized as having a transmittance of less than 10%/mm, less than 9%/mm, less than 8%/mm, less than 7%/mm, less than 6%/mm, less than 5%/mm, less than 4%/mm, less than 3%/mm, less than 2%/mm, and even less than 1%/mm for at least one 50 nm wide wavelength band of light in the NIR spectral region. In other embodiments, the glass-ceramic absorbs or has an absorption of at least 90%/mm, at least 91%/mm, at least 92%/mm, at least 93%/mm, at least 94%/mm, at least 95%/mm, at least 96%/mm, at least 97%/mm, at least 98%/mm, or even at least 99%/mm for at least one 50 nm wide wavelength band of light in the NIR spectral region.

Embodiments of the glass-ceramic materials of the present disclosure include aluminoborosilicate glass (e.g., containing SiO ₂ , Al ₂ O ₃ and B ₂ O ₃ ), WO ₃ , at least one alkali metal oxide, and at least one alkaline earth metal oxide. In some embodiments, the aluminoborosilicate glass comprises: about 55 mol % to about 80 mol % SiO ₂ , about 60 mol % to about 74 mol % SiO ₂ , or about 64 mol % to about 70 mol % SiO ₂ . In addition, the aluminoborosilicate glass of the glass-ceramic may comprise: about 2 mol % to about 40 mol % B ₂ O ₃ , about 5 mol % to about 16 mol % B ₂ O ₃ , or about 6 mol % to about 12 mol % B ₂ O ₃ . In addition, the aluminoborosilicate glass of the glass-ceramic may comprise: about 0.5 mol % to about 16 mol % Al ₂ O ₃ , about 2 mol % to about 20 mol % Al ₂ O ₃ , or about 6 mol % to about 14 mol % Al ₂ O ₃ .

The glass-ceramic material of the present disclosure comprises about 0.7 mol % to about 15 mol % WO _3. In some embodiments, the glass-ceramic material comprises about 1 mol % to about 6 mol % WO ₃ or about 1.5 mol % to about 5 mol % WO _3. In some practices, the glass-ceramic may also comprise about 0 mol % to about 50 mol % of the WO ₃ present in the composition (i.e., about 0 mol % to 5 mol %) of _{MoO 3.} In some embodiments, the glass-ceramic further comprises about 0 mol % to about 3 mol % or about 0 mol % to about 2 mol % MoO ₃ .

The glass-ceramic material of the present disclosure includes at least one alkali metal oxide. In an embodiment, the glass-ceramic material includes about 0.2 mol% to about 15 mol% of at least one alkali metal oxide. The at least one alkali metal oxide may be selected from the group consisting of Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O, and Cs ₂ O. In some practical modes, the difference between the amount of the at least one alkali metal oxide and Al ₂ O ₃ in the aluminoborosilicate glass ranges from -6 mol% to +2 mol%.

The glass-ceramic material of the present disclosure further comprises at least one alkaline earth metal oxide. In an embodiment, the glass-ceramic comprises from about 0.1 mol % to about 5 mol % of at least one alkaline earth metal oxide. The at least one alkaline earth metal oxide may be selected from the group consisting of MgO, SrO, and BaO. In other embodiments, the glass-ceramic material of the present disclosure comprises from about 0 mol % to about 0.5 mol %, from about 0 mol % to about 0.25 mol %, or from about 0 mol % to about 0.15 mol % SnO ₂ .

According to preferred practice, the glass-ceramic material of the present disclosure is substantially free of cadmium and substantially free of selenium. In embodiments, the glass-ceramic may further comprise at least one dopant selected from the group consisting of F, P, S, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Sb, Te, and Bi. In some embodiments, the at least one dopant present in the glass-ceramic is from about 0 mol % to about 0.5 mol %, calculated as oxide.

Non-limiting compositions of glass-ceramics according to principles of the present disclosure are shown below in Tables 1A (reported as weight %) and IB (reported as mole %).

Table 1A

Table 1A (continued)

Table 1B

Table 1B (continued)

According to an embodiment, the glass-ceramic material of the present disclosure can be manufactured by adopting a melt quenching process. The components of the appropriate proportion can be mixed and blended by turbulent mixing and/or ball milling. Batch materials may include, but are not limited to, one or more of: gravel, spodumene, petalite, nepheline, syenite, alumina, borax, boric acid, carbonates and nitrates of alkali metals and alkaline earth metals, tungsten oxides and ammonium tungstate. Then, the batched material is melted at a temperature of about 1500°C to about 1700°C for a predetermined time. In some practical ways, the predetermined time range is about 6 to about 12 hours, after which the resulting melt can be cast or formed, and then annealed, which is understood by those skilled in the art of the present disclosure. In some embodiments, the melt can be annealed at about 500°C to about 600°C to define the annealed melt.

At this stage of the process, the annealed melt is heat treated at about 500° C. to about 1000° C. for about 5 minutes to about 48 hours to form a glass-ceramic. In an embodiment, the heat treatment step is performed at or slightly above the annealing point and below the softening point of the glass-ceramic to establish one or more crystalline tungstate phases.

In some embodiments, the annealed melt is heat treated at about 600°C to about 800°C for about 5 minutes to about 24 hours to form a glass ceramic. According to some embodiments, the annealed melt is heat treated at about 650°C to about 725°C for about 45 minutes to about 3 hours to form a glass ceramic. In another practical mode, the annealed melt is heat treated according to the temperature and time to obtain specific optical properties, such as an optical transmittance of at least 90% from 700nm to 3000nm and a sharp cutoff wavelength of about 320nm to about 525nm. In addition, as described in the embodiments below, other heat treatment temperatures and times can be used to obtain glass ceramic materials.

Examples of Exemplary Applications

The following examples represent certain non-limiting examples of glass-ceramic materials and articles of the present disclosure, including methods of making them.

Referring now to Figures 2A and 2B, there are provided graphs of transmittance versus wavelength for a comparative CdSe glass ("Comparative Example 1") and a heat-treated glass-ceramic ("Example 1"). Note that Figure 2B is an image of Figure 2A, rescaled to show the cutoff wavelengths for the comparative CdSe glass and the heat-treated glass-ceramic samples. In this example _, the comparative _{CdSe glass (Comparative Example 1) has a conventional CdSe glass composition according to the following: 40-60% SiO2, 5-20% B2O3, 0-8% P2O5 , 1.5-6 % Al2O3 , 4-8} % _Na2O , 6-14% K2O, 4-12% ZnO, 0-6% BaO, 0.2-2.0CdO, 0.2-1% S, and 0-1% Se; while the heat-treated glass-ceramic has the same composition as the Example 1 sample shown in Tables 1A and 1B. In addition, the glass ceramic shown in Figures 2A and 2B is prepared according to the manufacturing method of the glass ceramic material described above in the present disclosure, including a heat treatment step, including heating the annealed melt at 700°C for about 1 hour. In addition, both samples shown in Figures 2A and 2B have a standardized path length of 4 mm. From these accompanying drawings, it is confirmed that the glass ceramic sample (Example 1) heat-treated at 700°C for 1 hour shows sharp cutoff and sharpness in the same wavelength range as the CdSe glass sample (Comparative Example 1).

Referring now to Figures 3A and 3B, there are provided graphs of transmittance versus wavelength for a comparative CdSe glass ("Comparative Example 1") and a heat-treated glass-ceramic ("Examples 1A-1K"). Note that Figure 3B is an image of Figure 3A, rescaled to show the cutoff wavelengths of the comparative CdSe glass and the heat-treated glass-ceramic samples. In this example _, the comparative CdSe glass (Comparative Example 1) has _a conventional CdSe glass composition according to the following: 40-60% _SiO2 , 5-20% _B2O3 , 0-8% _P2O5 , 1.5-6% _Al2O3 , 4-8% _Na2O , 6-14% _K2O , 4-12% ZnO, 0-6% BaO _, 0.2-2.0CdO, 0.2-1% S, and 0-1% Se; while the heat-treated glass-ceramic samples have the same composition as the Example 1 samples shown in Tables 1A and 1B, respectively. In addition, the glass ceramics shown in Figures 3A and 3B are prepared according to the manufacturing method of the glass ceramic material described above in the present disclosure, respectively, and include the following heat treatment steps after annealing: 525°C for 1 hour and 40 minutes (Example 1A); 525°C for 10 hours and 39 minutes (Example 1B); 550°C for 3 hours and 10 minutes (Example 1C); 600°C for 6 hours and 24 minutes (Example 1D); 600°C for 15 hours and 20 minutes (Example 1E); 650°C for 2 hours (Example 1F); 650°C for 3 hours (Example 1G); 650°C for 5 hours and 35 minutes (Example 1H); 650°C for 23 hours and 10 minutes (Example 1I); 700°C for 1 hour (Example 1J); and 700°C for 2 hours (Example 1K). In addition, all samples shown in Figures 3A and 3B have a standardized path length of 4 mm. It is confirmed from these figures that all glass ceramic samples (Examples 1A-1K) subjected to heat treatment according to various conditions exhibit sharp cutoff and sharpness in approximately the same wavelength range as CdSe glass (Comparative Example 1). In addition, it is confirmed from these figures that various heat treatment temperature and time conditions can be used to change and adjust the cutoff wavelength and its sharpness in the range of about 320nm to about 525nm.

According to another example, comparative CdSe glass and glass ceramic samples heat treated at 700°C and 800°C according to various conditions were prepared and their optical properties were evaluated. FIG4A is a graph of transmittance versus wavelength for comparative CdSe glass ("Comparative Example 1") and glass ceramic samples heat treated at 700°C and 800°C according to various conditions (Examples 1K and 2A). Note that FIG4B is an image of FIG4A that has been rescaled to show the cutoff wavelengths of comparative CdSe glass and glass ceramic samples heat treated according to various conditions. In this example, the comparative example CdSe glass (Comparative Example 1) has a conventional CdSe glass composition according _to the following: 40-60% _SiO2 , 5-20% _B2O3 , _0-8 % _P2O5 , _1.5-6 % _Al2O3 , 4-8% _Na2O , 6-14% _K2O , 4-12% ZnO, 0-6% BaO, 0.2-2.0CdO, 0.2-1% S, and 0-1% Se; the heat-treated glass-ceramic sample (Example 1K) has the same composition as the Example 1 sample shown in Tables 1A and 1B; and the heat-treated glass-ceramic sample (Example 2A) has the same composition as the Example 2 sample shown in Tables 1A and 1B. In addition, the glass ceramics shown in Figures 4A and 4B are prepared according to the manufacturing method of the glass ceramic material described above in the present disclosure, respectively, and include the following heat treatment steps after annealing: 700°C for 2 hours (Example 1K); and 800°C for 1 hour and 4 minutes (Example 2A). In addition, all samples shown in Figures 4A and 4B have a standardized path length of 4 mm. It is confirmed from these figures that all glass ceramic samples (Examples 1K and 2A) heat-treated according to various conditions exhibit sharp cutoff and sharpness in approximately the same wavelength range as CdSe glass (Comparative Example 1). In addition, it is also confirmed from these figures and the respective compositions of these glass ceramics (see Tables 1A and 1B) that these magnesium tungsten glass ceramic compositions can be used to change and adjust the cutoff wavelength and its sharpness in the range of about 320nm to about 525nm through specific heat treatment conditions. It is also apparent that the higher magnesium content (about 3.84 mol %) in the Example 2A glass ceramic compared to the Example 1K glass ceramic (about 0.95 mol %) may contribute to its lower cut-off wavelength and may contribute to its higher transmittance in the NIR range. Therefore, and without being limited by theory, changing the magnesium content in these glass ceramic compositions and changing the heat treatment conditions will have the effect of changing the spectrum and cut-off wavelength of the glass ceramics.

Referring now to FIG. 4C , the image of FIG. 4A is provided again, as well as a transmittance versus wavelength graph for comparative example CuInSe and CuInS glass samples (“Comparative Example 2” and “Comparative Example 3”, respectively). The spectra for Comparative Example 2 and Comparative Example 3 were obtained from the “Request for Renewal of Exemption 13(b)” submitted by Spectaris e.V. to Oko-Institute.V. on March 26, 2015. In addition, FIG. 4 is magnified to show the cutoff wavelengths for the comparative example CdSe glass (Comparative Example 1), the glass ceramic samples heat treated according to various conditions (Examples 1K and 2A), and the comparative example CuInSe and CuInS samples (Comparative Example 2 and Comparative Example 3). FIG. 4C confirms that the glass ceramic material according to the present disclosure (Example 1K and Example 2A) is superior to the comparative example CuInSe and CuInS glasses in approaching the cutoff wavelength of the comparative example CdSe glass. That is, the optical properties of these glass-ceramics are closer to those of CdSe glass than to other semiconductor-doped glass substitutes (CuInSe and CuInS).

Referring now to FIG. 5 , an X-ray diffraction (“XRD”) pattern of a heat-treated glass-ceramic (Example 1L, see Tables 1A and 1B) according to at least one example of the present disclosure is provided. This sample was heat treated at 700° C. for 17 hours and 16 minutes. From the peak evidence of the listed d spacings (e.g., d=3.6127, d=3.2193, etc.), the Example 1L glass-ceramic will include a crystalline MgWO ₄ tungsten oxide phase. Without being limited to theory, the XRD pattern of FIG. 5 also suggests that the glass-ceramic includes a non-stoichiometric MgWO ₄ phase or a mixed alkaline-MgWO ₄ phase, which can be described as M _x WO ₄ crystals, wherein M=Mg or M=Mg and one or more of an alkali metal selected from Li, Na, K, Rb and Cd, and 0<x<1.

Referring now to Fig. 6A-6C, there is provided a Raman spectrogram of a glass-ceramic sample (i.e., Fig. 6A, Example 1, no heat treatment after annealing) of splat-quenched and a glass-ceramic sample (respectively, Example 1H and Example 1L, as shown in Fig. 6B and 6C) of a heat treatment of 5 hours and 35 minutes at 650°C and 17 hours and 16 minutes at 700°C according to an example of the present disclosure. As in the previous embodiment, all glass-ceramic materials subjected to Raman microscopy testing all have the glass-ceramic composition according to Example 1 in Table 1A and 1B. The specific digital designation (e.g., "#1", "#2-orange", "#2-gray", etc.) associated with the data series in Fig. 6B&6C corresponds to a specific evaluation position (including the sample color at these positions) on the sample subjected to Raman spectroscopy testing. Fig. 6A confirms that the sample (Example 1) of splat-quenched without further heat treatment exhibits various increased intensity levels indicating that there is no crystalline phase (e.g., network bond Si-O, Al-O and BO at 470cm ^-1 ). In contrast, Figures 6B and 6C demonstrate that the heat treated samples (Examples 1H and 1L) have significantly higher intensity levels at the same Raman shift positions, which correlate with the lower intensity levels observed in the spray quenched sample (Example 1), indicating the presence of a crystalline phase (e.g., _WOW associated with _MgW2O7 at 846 & 868 cm ^-1 ). Thus, it appears to be demonstrated that the heat treatment conditions result in the establishment of a crystalline tungsten oxide phase (e.g., _{MgW2O7 )} , as evidenced by the presence of signal peaks at Raman shift positions (including but not limited to 345, 376, 404, 464, 718, 846, and 868 cm ^-1 ). Figures 6B and 6C also suggest that the heat treatment conditions result in the establishment of a crystalline tungsten suboxide phase (i.e., a non-stoichiometric phase) as a combination or alternative to the crystalline tungsten _{oxide phase (i.e., the MxWO4 crystalline} phase described above).

Referring now to Figs. 7A and 7B, Raman spectra of glass-ceramic samples (Example 1H and Example 1L, respectively) and glass-ceramic samples just sprayed and quenched (i.e., Example 1, without heat treatment after annealing) according to examples of the present disclosure are provided. As in the previous embodiments, all glass-ceramic materials subjected to Raman microscopy testing all have the glass-ceramic composition of Example 1 according to Tables 1A and 1B. The specific numerical designations (e.g., "#1", "#2-orange", etc.) associated with the data series in these figures correspond to specific evaluation locations (including the sample colors at these locations) on the samples subjected to Raman spectroscopy testing. Most importantly, Figs. 7A and 7B confirm that the sample subjected to spraying and quenching (Example 1) has a significantly lower intensity level at the same Raman shift position associated with the high intensity level associated with the sample subjected to specific heat treatment conditions (Examples 1H and 1L). Thus, it is demonstrated that the heat treatment conditions result in the establishment of a crystalline tungsten oxide phase (eg, MgW ₂ O ₇ as shown in both FIGS. 7A and 7B ) and/or a crystalline tungsten suboxide phase (ie, a non-stoichiometric phase).

Referring now to Fig. 8, there is provided a graph of residual stress (MPa) and substrate depth (mm) of two glass-ceramic samples (embodiment 10-10XA and embodiment 10-10XB) with compressive stress regions originating from two corresponding ion exchange process conditions. In Fig. 8, the y-axis is the residual stress in the substrate, and positive values refer to tensile residual stress and negative values refer to compressive residual stress. In addition, in Fig. 8, the x-axis is the depth in each substrate, and the values at 0mm and 1.1mm represent the main surface of the substrate (for example, the main surface 12 and 14 of the substrate 10 as shown in Figure 1). Each glass-ceramic sample (embodiment 10-10XA and embodiment 10-10XB) in this embodiment has the same composition as the embodiment 10 sample shown in Tables 1A and 1B. In addition, each sample is melted and cast onto a steel table to form an optical cake, consistent with the method described above in the present disclosure. Then, each sample is annealed at 570°C for one hour, and then cooled to ambient temperature at a furnace rate. The sample with dimensions of 25mm x 25mm x ~1.1mm was then ground and polished to form an annealed optical cake. Finally, the Example 10-IOXA sample was immersed in a 100% NaNO ₃ molten salt bath at 390°C for eight hours (8 hours) to form its compressive stress region. Similarly, Example 10-IOXB was immersed in a 100% NaNO ₃ molten salt bath at 390°C for sixteen hours (16 hours) to form its compressive stress region. It is noted that the actual thicknesses of Examples 10-IOXA and 10-IOXB measured were 1.10mm and 1.06mm, respectively.

Confirmed by Fig. 8, longer ion exchange duration tends to increase the size of DOC, storage strain energy and peak tension of glass ceramic (that is, the maximum tensile stress in the center tension zone), while reducing its maximum compressive stress.Specifically, the compressive stress region that the glass ceramic sample (embodiment 10-10XA) with shorter ion exchange duration exhibits has the compression depth (DOC) of 136.7 μm, the maximum compressive stress of about-320MPa, the center tension (CT) region given by the peak tension of 57MPa and the storage strain energy of 16.6J/m ^2.On the contrary, the glass ceramic sample (embodiment 10-10XB) with longer ion exchange duration exhibits 168.0 μm DOC, the maximum compressive stress of about-270MPa, the CT region given by the peak tension of 72MPa and the storage strain energy of 25J/m ² . Thus, the longer ion exchange duration of Example 10-IOXB results in a larger DOC, a lower maximum compressive stress, a CT area given by a larger peak tension, and a larger stored strain energy than Example 10-IOXA having a shorter ion exchange process duration.

Although it is confirmed that the above-mentioned glass-ceramic sample shown in Figure 8 exhibits a compressive stress region established by immersion in a molten salt bath of 100% _NaNO3 , other schemes are also considered in the present disclosure. For example, the glass-ceramic can also be ion-exchanged in a bath of molten _KNO3 , a mixture of _NaNO3 and _KNO3 , or first in a _NaNO3 bath and then in _KNO3 to increase the compressive stress level on the surface of the substrate and near the surface. Therefore, sulfates, chlorides and other salts of ion-exchanged metal ions (e.g., Na ⁺ , K ^+, etc.) can also be used in these baths. In addition, the ion exchange temperature can vary from about 350°C to 550°C, while the preferred range is 370°C to about 450°C to prevent salt decomposition and stress relaxation.

Referring generally to Figures 9 to 11B, different sized crystal regions are found in the tungsten bronze and multi-color tungsten bronze glass-ceramics described above. The crystal size depends on the base glass composition, but can also be slightly adjusted by heat treatment time and temperature. In addition, the crystallization rate is significantly increased with the addition of a small amount of calcium oxide (CaO), which is believed to interact with tungsten oxide to form nanocrystals of scheelite or non-stoichiometric scheelite-like structures that can act as nucleation sites.

Referring now to FIG. 9 , larger crystals are found in the highly peraluminous tungsten bronze melt (e.g., M _x WO ₃ glass ceramic) described above, and as shown in FIG. 9 . These crystals have a needle-like shape, a length of 100-250 nm, and a width of 5-30 nm. In the just-quenched state (rapid quenching between two iron plates, i.e., spray quenching), these glass-ceramic materials are X-ray amorphous and scanning electron microscope (SEM) analysis confirms the presence of no precipitates (crystals, microcrystals). After the quenched glass is heat treated at 700° C. for 30 minutes or more and cooled to room temperature at 10° C. per minute, tungsten bronze precipitates and alumina-enriched needles are formed. The precipitate concentration increases with increasing heat treatment time and temperature, for example, after heat treatment at 700° C. for 1 hour and 40 minutes and cooling to room temperature at 10° C./minute. The X-ray energy dispersive X-ray spectroscopy (EDS) diagram of the microcrystals formed after heat treatment shows that they include tungsten, oxygen, and potassium.

Referring to Figures 10A and 10B, for at least some of the overbased tungsten bronze melts ( _R2O - _AL2O3 >0), the crystallite _size is smaller than that in the overaluminous melts (Figure 9), and no alumina-enriched needles are formed. Similar to the overbased melts, this overbased material is X-ray amorphous when quenched between two iron plates (i.e., spray quenched). Microscope images show that no crystallites are present in the material prior to heat treatment. After heat treatment at 550°C spray quenching for 15 to 30 hours, followed by cooling to 475°C at 1°C/min, and then cooling to room temperature at a furnace rate, TEM analysis shows the formation of high aspect ratio needle-shaped tungsten bronze crystallites, as shown in Figures 10A to 10B. Most of the needles obtained are 2 to 7 nm in diameter and 10 to 30 nm in length. X-ray EDS of the heat treated, spray quenched samples shows that the crystallites contain tungsten.

Referring to Figures 11A and 11B, silver tungsten bronze glass-ceramics include crystallites that are roughly rod-shaped, with an aspect ratio of 2 to 4, most commonly about 2-20 nm in length, about 2-10 nm in diameter, and about 11 to 14.8% by volume of the material glass-ceramic. The sample shown in Figures 11A and 11B was heat treated at 550°C for 4 hours, cooled to 475°C at 1°C/minute, and then cooled to room temperature at a furnace rate. The rod was then placed in a gradient furnace for 5 minutes, so that one end of the rod was kept at room temperature and the other end of the rod was 650°C. The area between each end was exposed to an approximately uniform gradient between 25°C and 650°C temperatures. In the area where the temperature is higher than about 575°C, the color begins to shift from blue to green, to yellow, to orange, and finally to red. All colors are highly transparent.

As disclosed above, according to some exemplary embodiments, the glass ceramic has a transmittance of about 5%/mm or more in at least one 50nm wide wavelength band in the range of about 400nm to about 700nm. However, in other embodiments, the glass ceramic has a lower transmittance, such as those cases where it is opaque. According to at least some such embodiments, these glass ceramics are unique in that they have strong absorptivity, but do not scatter light and have very low haze. According to various such embodiments, for at least some (e.g., most, >90%) of light at 200-400nm wavelengths, the glass ceramic has an optical density per millimeter (OD/mm) of at least 0.07, a maximum of 25OD/mm for the same wavelength, and/or a haze of less than 10%, wherein the optical density is calculated by measuring the optical absorbance with a spectrophotometer, and the haze is measured by a haze meter wide angle scattering test. According to various such embodiments, for at least some (e.g., most, >90%) light of wavelengths between 400-750 nm, the glass-ceramic has an optical density per millimeter (OD/mm) of at least 0.022, up to 10 OD/mm for the same wavelength, and/or has a haze of less than 10%. According to various such embodiments, for at least some (e.g., most, >90%) light of wavelengths between 750-2000 nm, the glass-ceramic has an optical density per millimeter (OD/mm) of at least 0.04, up to 15 OD/mm for the same wavelength, and/or has a haze of less than 10%.

Embodiments containing titanium

Referring now to Tables 8A and 8B, a listing of exemplary glass-ceramic compositions for articles comprising titanium is provided.

Table 8A

Table 8B

Referring now to Table 8C and Figures 12A-17B, optical data for the composition samples of Tables 8A and 8B are provided.

Table 8C

The various compositions of Table 8C and Figures 12A-17B were prepared by weighing the batch components, mixing the batch components by a vibrating mixer or a ball mill, and melting in a fused silica crucible at a temperature of 1300°C-1650°C for 4-32 hours. The glass was poured onto a metal table to produce a 0.5 mm thick glass cake. Some of the melt was poured onto a steel table and then rolled into sheets using steel rollers. To establish and control optical transmittance and absorptivity, the samples were heat treated in an ambient air electric oven at a temperature of 425°C-850°C for 5-500 minutes. The sample cakes were then polished to a thickness of 0.5 mm and tested.

The data from Table 8C and Figures 12A-17B confirm that the as-fabricated state of titanium-containing glasses is highly transparent in the NIR region and is largely transparent at visible wavelengths. After heat treatment at temperatures of about 500°C to about 700°C, crystalline phases (i.e., titanium suboxides) precipitate, and the optical transmittance of these samples decreases and some become strongly absorbing in the NIR.

Powder X-ray diffraction was performed on each composition of Table 8C, indicating that all compositions were X-ray amorphous for the just-made and unannealed state. The heat-treated samples showed evidence of some titanium oxide-containing crystalline phases, including anatase (889FLY) and rutile (889FMC and 889FMD). The samples exhibited low haze (i.e., about 10% or less, or about <5% or less, or about 1% or less, or about 0.1% or less). Without being limited to theory, the low haze exhibited by these compositions in the just-made and heat-treated states is a result of the fact that the crystallites are very small (i.e., about 100nm or less) and are low in abundance (i.e., due to the fact that the introduced TiO ₂ is only about 2 mol %). Therefore, it is believed that the substances (size and abundance) formed in these materials are below the detection limit of conventional powder XRD. This conjecture was confirmed by TEM microscopy.

18A-D, TEM micrographs at four different magnifications of titanium oxide-containing crystals in a glass composition 889FMC sample heat treated at 700°C for 1 hour are provided. These crystals have a rod-like appearance and have an average width of about 5 nm and an average length of about 25 nm.

Referring now to Figures 19A and 19B, a TEM microscope image (Figure 19A) and a corresponding EDS elemental map (Figure 19B) of a heat-treated sample of glass number composition 889FMC are provided. As can be seen from Figure 19A, the sample includes a plurality of crystallites. The EDS map is set to detect titanium. It can be seen that the results of the EDS mapping of titanium closely follow the crystallite trajectory, indicating that the crystallites are enriched in titanium. In this figure, the bright or 'white' area indicates the presence of Ti.

Referring now to Table 9A, exemplary glass compositions that do not contain titanium are provided.

Table 9A

Table 9B provides solar performance measurements of various glasses. In Table 9B, composition 196KGA was combined as a cladding layer of a dual fusion laminate (i.e., total cladding glass ceramic thickness = 0.2 mm), wherein the core composition of the laminate was from Corning Inc. Chemical strengthening of Glass. Composition 196KGA is 1mm thick, heat treated at 550℃ for 30 minutes, and cooled to 475℃ at 1℃ per minute. 889FMD sample is 5mm thick, heat treated at 600℃ for 1 hour. 889FMG sample is 0.5mm thick, heat treated at 700℃ for 2 hours. VG10 sample refers to Saint-Gobain The glasses are sold under the trade name SGG VENUS (VG 10) and have different thicknesses from each other.

Table 9B

In Table 9B, T_L is the total visible light transmittance (this is the weighted average transmission of light through the glazing in the wavelength range of 380nm to 780nm, and is tested according to ISO 9050 Section 3.3). T_TS is the total transmitted solar energy (also called the Solar Factor ("SF") or Total Solar Heat Transmission ("TSHT"), which is the sum of T_DS (total direct solar energy) plus the portion absorbed by the glazing and then re-radiated into the vehicle interior, according to ISO 13837-2008 Annex B & ISO 9050-2003 Section 3.5). In this case, T_TS is calculated for a parked condition with a wind speed of 4m/s (14km/hr), and T_TS equals (%T_DS) + 0.276*(%Solar Absorption). T_DS is the total direct solar transmission (also called "solar transmittance" ("Ts") or "energy transmission", which is the weighted average transmission of light through the glazing in the wavelength range of 300nm to 2500nm, measured according to ISO13837, section 6.3.2). R_DS is the reflected solar component (i.e., nominal 4% Fresnel reflection). T_E is the direct solar transmission. T_UV is the UV transmittance, measured according to ISO 9050 and ISO 13837A. T_IR is the infrared transmittance, measured according to Volkswagen standard TL957.

As evidenced by the data in Table 9B, glass No. 196KGA has the best optical performance and is able to produce the lowest UV, visible light and NIR transmittance at a very short path length (0.2 mm). At 0.5 mm thickness, for path lengths of 3.85 mm or less, titanium-containing compositions 889FMD and 889FMG produce optical performance that is superior to that of VG10 glass. In other words, despite having a shorter path length, titanium-containing compositions 889FMD and 889FMG perform better than VG10 glass.

In addition, referring to at least some of the glass-ceramics disclosed or contemplated herein, the glass-ceramics include an amorphous phase and a crystalline phase, wherein the crystalline phase includes (e.g., comprises, is, is primarily) a bronze structure as disclosed herein, for example, a precipitate of formula M _x TiO ₂ , M _x WO _3, etc., as disclosed herein. The volume fraction of the crystalline phase may be about 0.001% to about 20%, or about 1% to about 20%, or about 5% to about 20%, about 10% to about 20%, or about 10% to about 30%, or about 0.001% to about 50%. In other embodiments, the volume fraction of the crystalline phase may be about 0.001% to about 20%, or about 0.001% to about 15%, or about 0.001% to about 10%, or about 0.001% to about 5%, or about 0.001% to about 1%. In other contemplated embodiments, the volume fraction of the crystalline phase in the glass-ceramic may be greater than 50%.

Further referring to at least some glass-ceramics disclosed or contemplated herein, the glass-ceramics include an amorphous phase and a crystalline phase, wherein the crystalline phase includes (e.g., comprises, is, is primarily) a bronze structure as disclosed herein, e.g., a glass-ceramic having a chemical formula of M _x TiO ₂ , M _x WO ₃ , etc., as disclosed herein, wherein M represents a dopant cation as disclosed herein, and the precipitate (e.g., crystal) is a low-valent oxide, wherein 0<x<1, for example, wherein 0<x<1, 0<x<0.9, for example, wherein 0<x<0.75, for example, wherein 0<x<0.5, for example, wherein 0<x<0.2, and/or for example, wherein 0.01<x<1, for example, wherein 0.01<x<1, for example, wherein 0.1<x<1, for example, wherein 0.2<x<1, and/or wherein 0.5<x<1, for example, wherein 0.001<x<0.999, for example, wherein 0.01<x<0.99, for example, wherein 0.1<x<0.9, for example, wherein 0.2<x<0.9, or wherein 0.1<x<0.8.

The construction and arrangement of the methods and products shown in various exemplary embodiments are only schematic. Although only some embodiments are described in detail in this disclosure, many improvements are feasible (e.g., the size, scale, structure, shape and ratio of various elements, parameter values, installation arrangements, use of materials, colors, orientations), which do not essentially deviate from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed can be composed of multiple parts or elements, the positions of the elements can be reversed or otherwise changed, and the properties or quantities of discrete elements or positions can be changed or altered. The order or sequence of any process, logical algorithm or method steps can be changed or reordered according to the alternative embodiments. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made to the design, operating conditions and arrangements of various exemplary embodiments.

Claims (18)

1. A method of making an article from a glass ceramic comprising a precipitate having the chemical formula M _xWO₃ and/or M _xMoO₃, wherein 0< x <1 and M is a dopant cation, the method comprising:

The regions of the glass-ceramic are bleached such that the concentration of precipitates in the bleached regions is lower than in the adjacent glass-ceramic.

2. The method of claim 1, wherein bleaching comprises laser rastering over the area.

3. A glass-ceramic article, comprising:

A precipitate of the formula M _xWO₃ and/or M _xMoO₃, wherein 0< x <1 and M is a dopant cation; and

The bleached region of the article has a lower concentration of the precipitate than the adjacent glass-ceramic of the article, wherein the precipitate is uniformly distributed in the glass-ceramic adjacent to the bleached region.

4. The article of claim 3, wherein the length of the precipitate is about 1nm to about 200nm as measured by electron microscopy.

5. The article of claim 3, wherein at least some of the precipitate is located at a depth greater than about 10 μm from the surface of the article.

6. The article of claim 3, wherein the volume fraction of precipitates in the glass-ceramic adjacent to the bleached region is from about 0.001% to about 20%.

7. An article according to claim 3, wherein the dopant cation is ：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、Cu、Pd、Se、Ta、Bi and/or Ce.

8. The article of claim 3, wherein the glass-ceramic adjacent to the bleached region has a transmittance of about 1%/mm or greater over at least one 50nm wide band of wavelengths of light in the range of about 400nm to about 700 nm.

9. The article of claim 8, wherein the glass-ceramic adjacent to the bleached region has an absorptivity of at least 90%/mm for light in at least one 50nm wide band of wavelengths of light in the ultraviolet portion of the spectrum.

10. The article of claim 8, wherein the glass-ceramic adjacent to the bleached region has an absorptivity of at least 90%/mm for light in at least one 50nm wide band of wavelengths of light in the near infrared portion of the spectrum, and the bleached region is non-absorptive in the near infrared portion.

11. A glass-ceramic article, comprising:

Precipitates of the formula M _xWO₃ and/or M _xMoO₃, wherein 0< x <1 and M is a cation of Ag, au and/or Cu; and

The bleached region of the article has a lower concentration of the precipitate than the adjacent glass-ceramic of the article, wherein the precipitate is uniformly distributed in the glass-ceramic adjacent to the bleached region.

12. The article of claim 11, wherein the length of the precipitate is about 1nm to about 200nm as measured by electron microscopy.

13. The article of claim 11, wherein at least some of the precipitate is located at a depth greater than about 10 μm from the surface of the article.

14. The article of claim 11, wherein the precipitate has a rod-like or needle-like morphology.

15. The article of claim 11, wherein the volume fraction of precipitates in the glass ceramic adjacent to the bleached region is about 0.001% to about 20%, and wherein the lower concentration in the bleached region is zero precipitates.

16. The article of claim 11, wherein the glass-ceramic adjacent to the bleached region has a transmittance of about 1%/mm or greater over at least one 50nm wide band of wavelengths of light in the range of about 400nm to about 700 nm.

17. The article of claim 16, wherein the glass-ceramic adjacent to the bleached region has an absorptivity of at least 90%/mm for light in at least one 50nm wide band of wavelengths of light in the ultraviolet portion of the spectrum.

18. The article of claim 16, wherein the glass-ceramic adjacent to the bleached region has an absorptivity of at least 90%/mm for light in at least one 50nm wide band of wavelengths of light in the near infrared portion of the spectrum, and the bleached region is non-absorptive in the near infrared portion.