Glass-ceramic, chemically strengthened glass-ceramic, cover plate glass and electronic device

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

Glass-ceramic, chemically strengthened glass-ceramic, cover glass and electronic equipment

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application No. 202410175049.4 filed with the State Intellectual Property Office of China on February 7, 2024, entitled “A glass-ceramic, chemically strengthened glass-ceramic, cover glass and electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the technical field of microcrystalline glass, and in particular to microcrystalline glass, chemically strengthened microcrystalline glass, cover glass and electronic equipment. Background Art

[0004] Glass-ceramics is a solid composite material formed by controlled crystallization of base glass during heat treatment. Glass-ceramics contains a microcrystalline phase and a glass phase. Compared with glass materials without a microcrystalline phase, glass-ceramics usually has higher strength. This is because the microcrystalline phase has higher strength than the glass phase and absorbs more energy when broken. In addition, the microcrystalline phase can extend the path of crack propagation and hinder the expansion of cracks, so it can consume more impact energy during the fracture process.

[0005] In recent years, glass-ceramics have been increasingly used in various electronic devices, such as mobile phones, watches, tablets, laptops, e-book readers, and similar devices, as cover glass for electronic devices, such as display screens and back covers. Display screens in electronic devices generally require cover glass with excellent optical properties, a thin thickness, and high mechanical properties. To further enhance the mechanical properties of glass-ceramics, chemical strengthening treatment is often required. Ion exchange is used to produce chemically strengthened glass-ceramics with higher stress levels, higher mechanical strength, and greater damage resistance.

[0006] Therefore, how to improve the chemical strengthening effect of microcrystalline glass while meeting excellent optical properties and to achieve rapid and efficient preparation of chemically strengthened microcrystalline glass with high stress levels and high mechanical strength properties is a technical problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0007] Because the structure of glass-ceramics differs from that of glass materials without a microcrystalline phase, the difficulty of chemical strengthening is also different. In order to prepare high-strength chemically strengthened glass-ceramics with high stress levels and high mechanical strength properties that meet the application requirements of cover glass optical performance, technicians in this field usually choose to chemically strengthen the existing glass-ceramics for a longer time, or use a high-temperature (e.g., over 480°C) molten salt bath to chemically strengthen the existing glass-ceramics. Whether extending the strengthening time or increasing the molten salt bath temperature, it will lead to an increase in the cost of chemically strengthening the glass-ceramics, that is, it will increase the manufacturing cost of high-strength chemically strengthened glass-ceramics.

[0008] The purpose of this application is to provide a microcrystalline glass with excellent optical properties and high intrinsic strength by adjusting the composition and structure of the microcrystalline glass, and the microcrystalline glass can be quickly and efficiently prepared under conventional chemical strengthening process conditions to obtain chemically strengthened microcrystalline glass with high stress level, excellent mechanical strength and excellent damage resistance.

[0009] In order to achieve the above objectives, this application provides the following technical solutions:

[0010] In a first aspect, a glass-ceramic is provided, wherein the glass-ceramic comprises a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the glass-ceramic;

[0011] Calculated by mole percentage of oxides, the components of the microcrystalline glass include: SiO2: 61.50% to 63.40%, Al2O3: 2.75% to 2.99%, P2O5: 0.91% to 1.91%, ZrO2: 4.20% to 4.85%, Na2O: 1.80% to 3.20%, B2O3: 0% to 1.00% and Li2O: 25.32% to 26.52%;

[0012] In the composition of the glass-ceramics, the molar percentage of Na2O [Na2O], the molar percentage of B2O3 [B2O3], and the molar percentage of ZrO2 [ZrO2] satisfy the following relationship:

[0013] Z=-1.344×(2.65-100×[Na2O])2+0.466×100×[B2O3]+1.203×100×[ZrO2], 4.80≤Z≤5.35, preferably, 4.98≤Z≤5.20.

[0014] By making the microcrystalline glass meet specific composition and crystal phase structure, making the content of each component of the microcrystalline glass and the ratio of the content of each component meet specific ranges, making Na2O, B2O3, ZrO2 or Li2O meet specific molar percentage relationships, and at the same time making the microcrystalline glass meet the requirement of lithium disilicate as the main crystal phase, not only can the microcrystalline glass be given excellent optical properties and high intrinsic strength, but also the microcrystalline glass can be quickly and efficiently produced with chemically strengthened microcrystalline glass with higher stress levels and higher mechanical strength properties under conventional chemical strengthening process conditions.

[0015] In some embodiments, in the composition of the glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of B2O3 [B2O3] satisfy the following relationship:

[0016] 0.90%≤[Na2O]-[B2O3]≤3.10%, preferably, 1.25%≤[Na2O]-[B2O3]≤3.02%, more preferably, 2.00%≤[Na2O]-[B2O3]≤3.00%.

[0017] In some embodiments, in the composition of the glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of Li2O [Li2O] satisfy the following relationship:

[0018] 8.55≤[Li2O] / [Na2O]≤13.85, preferably, 8.55≤[Li2O] / [Na2O]≤11.50.

[0019] In some embodiments, the weight proportion of the lithium disilicate crystal phase in all the crystal phases of the glass-ceramics is greater than 70%. Preferably, the weight proportion of the lithium disilicate crystal phase in all the crystal phases of the glass-ceramics is greater than 85%.

[0020] In some embodiments, the glass-ceramics comprises, in terms of mole percentage of oxides:

[0021] The molar percentage of SiO2 is 61.50% to 63.30%, preferably, the molar percentage of SiO2 is 62.00% to 62.60%; and / or,

[0022] The molar percentage of P2O5 is 1.20% to 1.91%, preferably, the molar percentage of P2O5 is 1.30% to 1.60%; and / or,

[0023] The molar percentage of Na2O is 1.85% to 3.05%, preferably, the molar percentage of Na2O is 2.20% to 3.00%; and / or,

[0024] The molar percentage of B2O3 is 0 to 0.65%; and / or, the molar percentage of ZrO2 is 4.20% to 4.80%; and / or,

[0025] The molar percentage of Li2O is 25.52% to 26.52%, and preferably, the molar percentage of Li2O is 25.52% to 26.00%.

[0026] In some embodiments, the glass-ceramics comprises, in terms of mole percentage of oxides:

[0027] The molar percentage of SiO2 is 62.88%, 63.30%, 62.50%, 63.26%, 62.38%, 62.27%, 62.45%, 62.22% or 63.17%; and / or,

[0028] The molar percentage of Al2O3 is 2.86%, 2.87%, 2.93%, 2.94% or 2.99%; and / or,

[0029] The mole percentage of P2O5 is 1.00%, 1.20%, 1.30%, 1.60%, 1.40%, 1.41%, 1.53% or 1.54%; and / or,

[0030] The molar percentage of ZrO2 is 4.80%, 4.74%, 4.84%, 4.33%, 4.34% or 4.35%; and / or,

[0031] The molar percentage of Na2O is 1.85%, 2.35%, 1.95%, 2.36%, 2.96%, 3.01%, 2.93% or 2.95%; and / or,

[0032] The molar percentage of Li2O is 25.62%, 25.82%, 25.69%, 25.36%, 25.77%, 25.87%, 25.90%, 25.79%, 26.03% or 25.74%.

[0033] In some embodiments, the composition of the glass-ceramics satisfies the following requirements, expressed in terms of the content expressed as a molar percentage of oxides:

[0034] The value of formula Z is 5.19, 5.10, 5.09, 5.06 or 5.13; and / or,

[0035] The value of [Na2O]-[B2O3] is 1.26%, 1.79%, 0.96%, 2.36%, 2.96%, 3.01%, 2.93% or 2.95%; and / or,

[0036] The value of [Li2O] / [Na2O] is 13.83, 10.93, 13.01, 10.92, 8.73, 8.61, 8.79 or 8.83.

[0037] In some embodiments, the crystallinity of the glass-ceramics is not less than 45%, preferably, the crystallinity of the glass-ceramics is 45% to 85%, and more preferably, the crystallinity of the glass-ceramics is 55% to 65%; and / or,

[0038] In the glass-ceramics, the average grain size does not exceed 100 nm, preferably, the average grain size does not exceed 40 nm, and more preferably, the average grain size is 15 to 30 nm.

[0039] In some embodiments, the microcrystalline glass is transparent in the visible light wavelength range. Preferably, at a thickness of 0.70 mm, for light with a wavelength of 550 nm, the transmittance of the microcrystalline glass is ≥90.00%, preferably the transmittance is >90.40%; and / or, at a thickness of 0.70 mm, the haze of the microcrystalline glass is <0.30%.

[0040] In some embodiments, at a thickness of 0.70 mm, the b value of the glass-ceramics is less than 0.70, and preferably, the b value is ≤ 0.60.

[0041] In some embodiments, the Young's modulus of the glass-ceramics is ≥100 GPa, preferably, the Young's modulus of the glass-ceramics is 105 to 112.50 GPa; and / or,

[0042] The Vickers hardness of the glass-ceramics is ≥640 kgf / mm 2 Preferably, the Vickers hardness of the glass-ceramics is 640-680 kgf / mm 2 .

[0043] In some embodiments, the glass-ceramic includes flat glass-ceramic or curved glass-ceramic; preferably, when the glass-ceramic is curved glass-ceramic, the glass-ceramic can be made by 3D hot bending processing of crystallized glass raw material with a crystallinity of not less than 5%.

[0044] In some embodiments, the microcrystalline glass is prepared by heat treatment of substrate glass. Preferably, the heat treatment process includes nucleation treatment and / or crystallization treatment. Preferably, the crystallization treatment includes one-step crystallization treatment or two-step crystallization treatment. Preferably, curved microcrystalline glass can be prepared by two-step crystallization treatment. When a two-step crystallization treatment is adopted, the second step crystallization treatment is to heat the crystallized glass raw material obtained by the first step crystallization treatment to the crystallization temperature and perform 3D hot bending forming treatment, and the second crystallization is performed during the 3D hot bending forming process.

[0045] In some embodiments, the glass-ceramics has a thickness of 0.10 to 5.00 mm.

[0046] In the second aspect, a chemically strengthened microcrystalline glass is provided, wherein the chemically strengthened microcrystalline glass is obtained by chemically strengthening the microcrystalline glass described in any embodiment of the first aspect, and the composition at the center of the chemically strengthened microcrystalline glass is the same as the composition of the microcrystalline glass described in any embodiment of the first aspect. The chemically strengthened microcrystalline glass includes a compressive stress layer region extending from the surface of the chemically strengthened microcrystalline glass to the compression depth, and has tensile stress inside the chemically strengthened microcrystalline glass, that is, the chemically strengthened microcrystalline glass includes a compressive stress layer and a tensile stress layer.

[0047] In some embodiments, the chemically strengthened glass-ceramics comprises a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the chemically strengthened glass-ceramics; and the composition at the center of the chemically strengthened glass-ceramics comprises, in terms of molar percentage of oxides: SiO2: 61.50% to 63.40%, Al2O3: 2.75% to 2.99%, P2O5: 0.91% to 1.91%, ZrO2: 4.20% to 4.85%, Na2O: 1.80% to 3.20%, B2O3: 0% to 1.00%, and Li2O: 25.32% to 26.52%.

[0048] In the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O], the molar percentage of B2O3 [B2O3], and the molar percentage of ZrO2 [ZrO2] satisfy the following relationship:

[0049] Z=-1.344×(2.65-100×[Na2O])2+0.466×100×[B2O3]+1.203×100×[ZrO2], 4.80≤Z≤5.35, preferably, 4.98≤Z≤5.20.

[0050] In some embodiments, in the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of B2O3 [B2O3] satisfy the following relationship:

[0051] 0.90%≤[Na2O]-[B2O3]≤3.10%, preferably, 1.25%≤[Na2O]-[B2O3]≤3.02%, more preferably, 2.00%≤[Na2O]-[B2O3]≤3.00%; and / or,

[0052] In the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of Li2O [Li2O] satisfy the following relationship:

[0053] 8.55≤[Li2O] / [Na2O]≤13.85, preferably, 8.55≤[Li2O] / [Na2O]≤11.50.

[0054] In some embodiments, the chemically strengthened glass-ceramics has a CT_LD of 45,000 to 55,000 MPa / mm, where CT_LD is a tensile stress linear density. Preferably, the chemically strengthened glass-ceramics has a CT_LD of 48,000 to 53,000 MPa / mm; and / or

[0055] The chemically strengthened glass-ceramics has a DOL_0 of 0.18t to 0.25t, where DOL_0 is a depth of a compressive stress layer and t is a thickness of the chemically strengthened glass-ceramics. Preferably, the chemically strengthened glass-ceramics has a DOL_0 of 0.20t to 0.25t; and / or

[0056] The chemically strengthened glass-ceramics has a CS_50 of 150 to 199 MPa, where CS_50 refers to the compressive stress value at a depth of 50 μm from the main surface of the chemically strengthened glass-ceramics. Preferably, the chemically strengthened glass-ceramics has a CS_50 of 160 to 199 MPa; and / or

[0057] The chemically strengthened glass-ceramics has a |CT_AV| of 80 to 98 MPa, where |CT_AV| is the absolute value of the average tensile stress; and / or,

[0058] The chemically strengthened glass-ceramics has a |CT_CV| of 115 to 142 MPa, where |CT_CV| is an absolute value of the maximum tensile stress. Preferably, the chemically strengthened glass-ceramics has a |CT_CV| of 120 to 140 MPa.

[0059] In some embodiments, the chemically strengthened glass-ceramics has a Vickers hardness greater than or equal to 680 kgf / mm 2 Preferably, the Vickers hardness of the chemically strengthened glass-ceramics is 700 kgf / mm 2 ~800kgf / mm 2 .

[0060] In a third aspect, a glass device is provided, wherein the glass device comprises the microcrystalline glass as described in any embodiment of the first aspect or the chemically strengthened microcrystalline glass as described in any embodiment of the second aspect.

[0061] In a fourth aspect, a cover glass is provided. The cover glass is made of the glass-ceramic described in any embodiment of the first aspect or the chemically strengthened glass-ceramic described in any embodiment of the second aspect. That is, the cover glass includes the glass-ceramic described in any embodiment of the first aspect or the chemically strengthened glass-ceramic described in any embodiment of the second aspect. The cover glass can be a display cover, back cover, or camera protection cover of an electronic device.

[0062] In a fifth aspect, an electronic device is provided, which includes the microcrystalline glass as described in any embodiment of the first aspect or the chemically strengthened microcrystalline glass as described in any embodiment of the second aspect.

[0063] In some embodiments, the electronic device includes a housing assembled on the outside of the electronic device, and a circuit board located inside the housing, and the housing includes the microcrystalline glass as described in any embodiment of the first aspect or the chemically strengthened microcrystalline glass as described in any embodiment of the second aspect.

[0064] In some embodiments, the housing includes a display cover assembled on the front side of the electronic device, and the display cover includes the microcrystalline glass as described in any embodiment of the first aspect or the chemically strengthened microcrystalline glass as described in any embodiment of the second aspect.

[0065] In some embodiments, the housing includes a back cover assembled on the back side of the electronic device, and the back cover includes the microcrystalline glass as described in any embodiment of the first aspect or the chemically strengthened microcrystalline glass as described in any embodiment of the second aspect.

[0066] In some embodiments, the electronic device also includes a camera assembly located inside the housing, the housing includes a camera protection cover, the camera protection cover is covered on the camera assembly, and the camera protection cover includes the microcrystalline glass as described in any embodiment of the first aspect or the chemically strengthened microcrystalline glass as described in any embodiment of the second aspect.

[0067] In some embodiments, the electronic device further includes a middle frame located between the display module and the housing, and the middle frame includes the microcrystalline glass as described in any embodiment of the first aspect or the chemically strengthened microcrystalline glass as described in any embodiment of the second aspect.

[0068] In some embodiments, the housing may be partially or entirely made of glass-ceramic or chemically strengthened glass-ceramic. The electronic device in this application may include a display cover, a back cover, a camera protection cover, or a middle frame that includes the glass-ceramic described in any embodiment of the first aspect or the chemically strengthened glass-ceramic described in any embodiment of the second aspect.

[0069] One or more of the above technical solutions provided by this application include the following advantages:

[0070] The present application makes the microcrystalline glass meet specific composition and crystal phase structure, makes the content of each component of the microcrystalline glass and the ratio of the content of each component meet specific ranges, makes Na2O, B2O3, ZrO2 or Li2O meet specific molar percentage relationships, and makes the microcrystalline glass meet the requirement of lithium disilicate as the main crystal phase. This not only gives the microcrystalline glass excellent optical properties and high intrinsic strength, but also enables the microcrystalline glass to be quickly and efficiently produced with high stress levels and high mechanical strength properties under conventional chemical strengthening process conditions, thereby effectively reducing the manufacturing cost of high-strength chemically strengthened microcrystalline glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0072] FIG1 is an XRD pattern of the glass-ceramics of Example 2.

[0073] FIG2 is a transmittance curve of the glass-ceramics of Example 2 in the 360 ​​nm-740 nm band.

[0074] FIG3 is a comparison diagram of the XRD patterns of the glass-ceramics of Example 2 before and after chemical strengthening.

[0075] FIG4 is a physical picture of the glass-ceramics of Example 2.

[0076] FIG5 is a physical picture of the glass-ceramics of Example 7.

[0077] FIG6 is a physical picture of the glass-ceramics of Comparative Example 5.

[0078] FIG7 is a physical picture of the glass-ceramics of Comparative Example 6.

[0079] FIG8 is a physical picture of the glass-ceramics of Comparative Example 8.

[0080] FIG9 is a schematic diagram of the front structure of an electronic device provided in an embodiment of the present application.

[0081] FIG10 is a schematic diagram of the rear structure of the electronic device provided in an embodiment of the present application.

[0082] FIG11 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0083] Figure numerals: 1-housing; 11-display screen cover; 12-back cover; 13-camera protection cover; 2-camera assembly; 3-middle frame; 4-display module. DETAILED DESCRIPTION

[0084] The embodiments of the present application will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0085] The endpoints and any values ​​of the scope disclosed in this article are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, between the endpoint values ​​of each scope, between the endpoint values ​​of each scope and a separate point value, and between separate point values, one or more new numerical ranges can be combined with each other, and these numerical ranges should be considered as specifically disclosed in this article. Wherein, the terms "optional" and "optional" all refer to and may include, but may not include (or may have, or may not have). As used herein, "and / or" is inclusive, for example, "A and / or B" refers to only A, or only B, or both A and B.

[0086] Explanation of terms and test methods:

[0087] In this application, glass-ceramics is a type of solid composite material that contains both a glass phase and a crystalline phase (also called a microcrystalline phase or a crystalline phase). Glass-ceramics is also known as glass ceramics or crystallized glass.

[0088] In this application, chemically strengthened glass-ceramics refers to a solid composite material obtained by chemically strengthening glass-ceramics. It should be understood that during chemical strengthening, alkali metal ions with large ionic radii (such as potassium ions or sodium ions) in the molten salt bath (also known as the molten salt bath) replace alkali metal ions with smaller ionic radii (such as sodium ions or lithium ions) in the glass-ceramics, thereby generating an exchange ion volume difference and producing compressive stress (also known as compression stress) on the surface of the glass-ceramics.

[0089] In the present application, substrate glass refers to glass that has not been subjected to nucleation treatment, crystallization treatment, and strengthening treatment, or is also called basic glass.

[0090] In this application, the composition at the center of a chemically strengthened glass-ceramics refers to the composition at or near the center of the depth or thickness of the chemically strengthened glass-ceramics, that is, the composition of the region of the chemically strengthened glass-ceramics that has not undergone ion exchange. It should be understood that the composition at the center of the chemically strengthened glass-ceramics is the same as or substantially the same as the composition of the glass-ceramics used to prepare the chemically strengthened glass-ceramics but which has not yet undergone chemical strengthening.

[0091] In this application, the visible light wavelength range refers to 360nm to 740nm.

[0092] In this application, haze is the percentage of transmitted light intensity that deviates from the incident light by more than 2.5° to the total transmitted light intensity.

[0093] In the present application, the main crystalline phase (or also referred to as the main crystalline phase) refers to a crystalline phase having a higher weight content (or also referred to as weight percentage, mass percentage) than other crystalline phases present in the microcrystalline glass.

[0094] In this application, the main surface refers to the surface with the largest surface area in a glass brick or glass sheet, such as the upper surface or lower surface of a horizontally placed microcrystalline glass sheet.

[0095] In this application, crystallinity refers to the percentage of the total mass of the crystalline phase or crystals in the microcrystalline glass to the mass of the microcrystalline glass, or is also called the total content of the crystalline phase in the microcrystalline glass.

[0096] In the present application, when light of a certain wavelength is irradiated onto the main surface of the microcrystalline glass, the light will be reflected, absorbed and transmitted, and the ratio of the intensity of the transmitted part to the intensity of the incident light is the transmittance.

[0097] In the present application, the D65 light source is a light source for measuring the color of an object illuminated by sunlight including ultraviolet light, having a color temperature of 6500K and a color rendering index Ra of more than 90, and exhibits a broad spectral distribution in the visible wavelength region.

[0098] In this application, crystallized glass raw material refers to glass raw material that has been heat treated for a period of time to achieve a certain degree of crystallinity, but has not yet reached the target crystallinity, and can continue to crystallize when heated to reach the target crystallinity.

[0099] In this application, CT_LD refers to the tensile stress linear density, and the unit is MPa / mm. It should be understood that after the microcrystalline glass is placed in a molten salt bath for ion exchange, a compressive stress layer (or also called a compressive stress layer) will be formed on the surface of the microcrystalline glass, and a tensile stress layer (or also called a tensile stress layer) will be formed inside the microcrystalline glass. Exemplarily, during chemical strengthening treatment, alkali metal ions with a large radius in the molten salt bath are ion exchanged with alkali metal ions with a small radius in the microcrystalline glass, thereby forming a compressive stress layer on the surface of the microcrystalline glass and a tensile stress layer inside the microcrystalline glass, that is, a chemically strengthened microcrystalline glass comprising a compressive stress layer and a tensile stress layer is prepared. In this application, CT_LD is calculated by the following formula:

[0100] Where t is the thickness of the chemically strengthened glass-ceramic, in mm; DOL_0 is the depth of the compressive stress layer of the chemically strengthened glass-ceramic, in μm; and |CT_AV| is the absolute value of the average tensile stress of the chemically strengthened glass-ceramic, in MPa. It should be understood that the calculation formula for tensile stress linear density is based on the aforementioned unit requirements, and the units are not involved in the calculation.

[0101] In this application, CS_50 refers to the compressive stress value at a depth of 50 μm from the main surface of the chemically strengthened microcrystalline glass, in MPa, obtained by testing with an SLP-2000 stress meter.

[0102] In this application, |CT_AV| refers to the absolute value of the average tensile stress, in MPa, specifically the absolute value of the average value of all tensile stresses in the tensile stress layer, obtained by testing with an SLP-2000 stress meter.

[0103] In this application, |CT_CV| refers to the absolute value of the maximum tensile stress, in MPa, specifically the absolute value of the maximum value of all tensile stresses in the tensile stress layer, obtained by testing with an SLP-2000 stress meter.

[0104] In this application, DOL_0 refers to the depth of the compressive stress layer, or the depth of the compressive stress layer, specifically the distance from any main surface of the chemically strengthened microcrystalline glass to the position where the compressive stress near the surface is zero, obtained by testing with the SLP-2000 stress meter.

[0105] In this application, the stress properties described above were tested using the following method: |CT_CV|, DOL_0, and |CT_AV| of the chemically strengthened glass-ceramics using an SLP 2000 stress meter. The stress meter parameters were set to: a light source wavelength of 518 nm, a SOC (photoelastic coefficient) of 26 [(nm / cm) / MPa], a refractive index of 1.56, and an exposure time of 300 μsec. The tensile stress linear density (CT_LD) of the chemically strengthened glass-ceramics was then calculated using the aforementioned tensile stress linear density formula.

[0106] In this application, the b value is used to characterize the yellow-blue value of a material. The b value in this application is the b value of transmitted light, and a positive b value indicates that the material is blue.

[0107] In this application, Vickers hardness refers to a standard for expressing the hardness of a material proposed by Robert L. Smith and George E. Sandland of the United Kingdom at Vickers Ltd in 1921.

[0108] In this application, the test method of Vickers hardness is as follows: make microcrystalline glass or chemically strengthened microcrystalline glass into a small piece with a length, width and thickness of 50mm×50mm×0.70mm, and select a glass sample with a clean surface and no visible scratches, pits, cracks and other damage as a test sample, and then use a Vickers hardness tester to measure its Vickers hardness. The Vickers hardness tester used in the test of this application is a digital display small load Vickers hardness tester with model VTD405 of Beijing Kewei Technology Co., Ltd. Test conditions: load 300gf, load time 10s, the effectiveness of the indentation complies with the "GB / T 37900-2019 Ultra-thin glass hardness and fracture toughness test method small load Vickers hardness indentation method" standard. Select 3 different positions on the surface of the same test sample for measurement, and take the average of the 3 measurement results, which is recorded as the Vickers hardness result of the test sample.

[0109] In this application, Young's modulus is used to characterize the ability of glass to resist elastic deformation due to external forces. This application uses the UMS-100 ultrasonic material characterization system to test the Young's modulus of microcrystalline glass using acoustic waves.

[0110] In the present application, nucleation treatment refers to the process of growing small crystal nuclei from nucleating substances in the substrate glass through heat treatment; and crystallization treatment refers to the process of growing certain crystals based on the crystal nuclei through heat treatment.

[0111] In this application, the thickness of the glass-ceramics is measured by micrometer testing. It should be understood that in the thickness direction, the degree of ion exchange varies gradually from the surface to the center, and the overall Na-K and / or Li-Na exchange increment (mass) generally does not exceed 1.5% of the total mass of the sample. Therefore, the expansion effect in the thickness direction is extremely slight, and it can be approximately considered that the thickness has basically not changed. In other words, the thickness of the glass-ceramics before and after chemical strengthening is very small and can be basically ignored. The thickness of the glass-ceramics is basically the same as the thickness of the chemically strengthened glass-ceramics obtained therefrom.

[0112] In this application, the size specifications of the microcrystalline glass sheets are tested using a two-dimensional measuring machine (instrument model is Miyu MY-YXCL-4030).

[0113] In the present application, the crystal phase, crystallinity and average grain size of the glass-ceramics or chemically strengthened glass-ceramics are confirmed by XRD testing.

[0114] Specifically:

[0115] (1) XRD testing: The glass-ceramics or chemically strengthened glass-ceramics of the present application were crushed and ground into samples with a particle size of less than 75 μm. The ground samples were tested using an X-ray diffractometer to obtain XRD diffraction peak curves and XRD diffraction data. The X-ray diffractometer used in this application was a Shimadzu XRD-6100, with a copper target, 2θ = 10°-50°, a scanning speed of 6° / min, an operating voltage of 40 kV, and an operating current of 30 mA.

[0116] (2) Determination of crystalline phase: XRD diffraction data were analyzed using Jade software (JADE Standard 8.6) to determine the crystalline phase in the sample.

[0117] (3) Determination of crystallinity (also known as total crystalline phase content): XRD test results (RAW format) were imported into the X-ray diffraction data Rietveld refinement software Jade for fitting and calculation to determine the crystallinity of the sample. Specifically, the ratio of the fitted crystalline phase peak area to the total fitted peak area was recorded as the crystallinity of the sample.

[0118] (4) Determination of average grain size (or also called average crystal size): The average grain size of the sample can be calculated using the result data obtained from the XRD test according to the Scherrer formula D = Kλ / (βcosθ). Wherein, λ is the X-ray wavelength, λ = 0.154056nm, β is the half-maximum width of the diffraction peak, K = 0.89, and θ is the Bragg diffraction angle. Specifically, the RAW format file output by the XRD instrument is curve fitted in the Jade software. Jade outputs a fitting report. Based on the angle 2θ value and Peak FWHM value corresponding to each diffraction peak in the fitting report, the Peak FWHM value is converted to radians: β = (FWHM / 180×3.14). The grain size of each diffraction peak is calculated using the Scherrer formula D = Kλ / (βcosθ) and then averaged to obtain the average grain size in the sample.

[0119] In this application, with reference to the national standard "GB / T 7962.12-2010 Test Methods for Colorless Optical Glass Part 12: Spectral Transmittance," a haze meter was used to test the transmittance, haze, and b-value of the glass-ceramics of this application. Specifically, a haze meter was used to test the transmittance, haze, and b-value of five glass-ceramics from the same batch for light of different wavelengths. The b-value and haze values ​​measured for the five glass-ceramics were averaged and recorded as the b-value and haze results, respectively, for the glass-ceramics. The transmittance of the five glass-ceramics at a wavelength of 550 nm was averaged and recorded as the transmittance of the glass-ceramics at a wavelength of 550 nm. The haze meter used in the test of this application is a Konica Minolta spectrophotometer CM-3600A from Japan. The light receiving optical system is transmission, the spectroscopic method is a plane reflective grating, the wavelength range is 360nm-740nm, the wavelength spacing is 10nm, the illumination light source is 4 pulsed xenon lamps, and the ambient temperature of the instrument is 24°C and the air humidity is 40%.

[0120] In this application, the average sandpaper drop height of the chemically strengthened glass-ceramics tested is the sum of the sandpaper drop heights of the chemically strengthened glass-ceramics in the same embodiment or the same comparative example, and the value obtained by dividing it by the number of samples tested is recorded as the average sandpaper drop height of the tested chemically strengthened glass-ceramics, which is used to characterize the drop damage resistance of the chemically strengthened glass-ceramics. Specifically, at least 10 samples are taken from each batch for testing, and the average sandpaper drop height is Where n is the number of glass samples tested in each batch, hi is the sandpaper drop resistance height of a single sample test;

[0121] Among them, the test method for a single sample's resistance to sandpaper drop height is:

[0122] Step 1: Apply 80-grit sandpaper to the bottom surface of the 181g model machine and place the model machine on the green figure LT-SKDL-CD drop machine;

[0123] Step 2: Place the chemically strengthened glass-ceramic sample to be tested directly under the model machine, with the chemically strengthened glass-ceramic sample facing the sandpaper, specifically, with the main surface of the chemically strengthened glass-ceramic facing the sandpaper. Make the model machine fall from a certain drop height to impact the chemically strengthened glass-ceramic sample directly under the model machine. If the chemically strengthened glass-ceramic sample does not break, increase the drop height of the model machine in a certain pattern, and make the model machine continue to fall, impacting the chemically strengthened glass-ceramic sample directly under the model machine, until the chemically strengthened glass-ceramic sample breaks. For example, the drop height of the model machine starts from 0.4m, and the sample is dropped once. If the sample does not break, the drop height of the model machine is increased by 0.1m, and it falls again. Repeat the above process until the chemically strengthened glass-ceramic sample breaks;

[0124] Step 3: The last drop height of the chemically strengthened glass-ceramic sample before it breaks is recorded as its sandpaper drop height. For example, if the drop height is increased by 0.1m each time, and the drop height of the sample is 0.5m when it breaks, the sandpaper drop height of the sample is 0.4m.

[0125] Without being bound by any theory, it is speculated that when glass-ceramics undergoes chemical strengthening treatment, it is mainly the alkali metal ions in the glass phase that undergo ion exchange with the alkali metal ions in the molten salt bath, thereby forming a compressive stress structure on the surface of the glass-ceramics, so as to further enhance the mechanical strength and damage resistance of the glass-ceramics. Although the dense grain structure contained in the glass-ceramics is beneficial to improving the intrinsic strength (or inherent strength) of the glass-ceramics and improving the damage resistance of the glass-ceramics, the interconnected structure formed by the dense grains in the glass-ceramics will seal the glass phase (or residual glass phase) between the grains, which will hinder the ion exchange path, thereby hindering the alkali metal ions in the glass phase from ion exchange with the alkali metal ions in the molten salt bath for chemical strengthening, which will increase the difficulty of obtaining high stress performance by chemically strengthening the glass-ceramics, that is, it will increase the difficulty of manufacturing high-strength chemically strengthened glass-ceramics. In particular, the lithium aluminum silicate glass system is prone to precipitating non-single crystalline phases after heat treatment. The possible precipitated crystalline phases include lithium disilicate crystalline phase, quartz crystalline phase or lithium metasilicate crystalline phase, and non-single crystalline phase microcrystalline glass often has higher crystallinity. The higher the crystal content, the more energy and time required for ion diffusion will tend to increase. That is, the non-single crystalline phase structure may further increase the difficulty of ion exchange in microcrystalline glass.

[0126] In existing technologies, to produce chemically strengthened glass-ceramics that meet application requirements, the existing glass-ceramics are typically chemically strengthened for a prolonged period of time, or chemically strengthened in a high-temperature (e.g., over 480°C) molten salt bath. However, both the extended strengthening time and the increased temperature of the molten salt bath increase the cost of chemically strengthening the glass-ceramics, leading to increased manufacturing costs for high-strength chemically strengthened glass-ceramics.

[0127] In view of this, and to improve economic efficiency, the present application provides a glass-ceramic that, unlike the prior art, has excellent optical properties and high intrinsic strength, and is capable of rapid ion exchange to achieve a high stress level. The glass-ceramic in the present application can be quickly and efficiently prepared under conventional chemical strengthening process conditions to obtain chemically strengthened glass-ceramics with high stress levels, excellent mechanical strength, and excellent damage resistance.

[0128] As described above, in some embodiments of the present application, a glass-ceramic is provided, wherein the glass-ceramic contains a lithium disilicate crystalline phase (Li2Si2O5), wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the glass-ceramic; and the components of the glass-ceramic, in terms of molar percentage of oxides, include: SiO2: 61.50% to 63.40%, Al2O3: 2.75% to 2.99%, P2O5: 0.91% to 1.91%, ZrO2: 4.20% to 4.85%, Na2O: 1.85% to 3.20%, B2O3: 0 to 1.00%, and Li2O: 25.32% to 26.52%.

[0129] In the composition of the glass-ceramics, the molar percentage of Na2O [Na2O], the molar percentage of B2O3 [B2O3], and the molar percentage of ZrO2 [ZrO2] satisfy the following relationship:

[0130] Z=-1.344×(2.65-100×[Na2O])2+0.466×100×[B2O3]+1.203×100×[ZrO2], 4.80≤Z≤5.35, preferably, 4.98≤Z≤5.20.

[0131] The lithium disilicate (Li2Si2O5) crystalline phase is an orthorhombic crystal based on an array of [Si2O5] tetrahedrons, and the shape of the crystal is flat or plate-like. Inside the glass-ceramics, the lithium disilicate crystals are randomly oriented interlocking microstructures, forcing the crack path to be distorted when passing through the crystal, thereby preventing the crack from expanding and improving the strength and fracture toughness of the glass-ceramics. At the same time, the refractive index of the lithium disilicate crystals is close to that of the glass matrix (such as the base glass for preparing the glass-ceramics in this application), and it is an ideal crystalline phase for preparing highly transparent glass-ceramics. In this application, the glass-ceramics contains a structure with lithium disilicate as the main crystalline phase, which is conducive to ensuring that it obtains high intrinsic strength (or also known as inherent strength) and excellent optical properties.

[0132] In the present application, by making the microcrystalline glass meet a specific composition and crystal phase structure, making the content of each component of the microcrystalline glass and the ratio of the content of each component meet a specific range, making the specific molar percentage relationship between Na2O, B2O3, ZrO2 or Li2O, and at the same time making the microcrystalline glass meet the requirement of lithium disilicate as the main crystal phase, not only can the microcrystalline glass be given excellent optical properties and high intrinsic strength, but also the microcrystalline glass can be quickly and efficiently produced with a higher stress level and higher mechanical strength performance under conventional chemical strengthening process conditions, thereby effectively reducing the manufacturing cost of high-strength chemically strengthened microcrystalline glass.

[0133] The glass-ceramics of the present application can be prepared by heat-treating a substrate glass. In terms of the molar percentage of oxides, the composition of the substrate glass used is the same or substantially the same as that of the glass-ceramics.

[0134] In the present application, SiO2 is an essential component for forming the glass network structure and is also one of the main components for forming lithium disilicate crystals. The higher the SiO2 content, the denser the network structure of the glass phase. Correspondingly, the mechanical strength of the microcrystalline glass will be higher, the thermal expansion coefficient will be smaller, and the heat resistance, dielectric properties and chemical stability will be better. However, if the SiO2 content is too high, the melting temperature of the substrate glass will be too high, the melt viscosity will be too high, and the molding difficulty of the substrate glass will be increased. Therefore, in order to take into account the formability and various excellent properties of the glass, the molar percentage of SiO2 in the substrate glass or microcrystalline glass is set to 61.50% to 63.40% in the present application, preferably 61.50% to 63.30%, and more preferably 62.00% to 62.60%.

[0135] In some embodiments of the present application, the content of SiO2 in the substrate glass or glass-ceramics can be 62.87%, 62.88%, 63.25%, 63.26%, 62.38%, 62.27%, 62.44%, 62.45%, 62.22%, 63.17%, 61.50%, 61.60%, 61.70%, 61.80%, 61.90%, 62.0 ... 62.10%, 62.20%, 62.30%, 62.40%, 62.50%, 62.60%, 62.70%, 62.80%, 62.90%, 63.00%, 63.10%, 63.20%, 63.30% or 63.40%, or a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the micro-ceramics or chemically strengthened micro-ceramics with the desired performance of the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the micro-ceramics or chemically strengthened micro-ceramics with the desired performance of the present application can be obtained.

[0136] In this application, Al2O3 is a component that forms the glass network structure. An appropriate amount of Al2O3 is beneficial for improving the chemical strengthening effect of the glass-ceramics and, to a certain extent, promoting ion exchange during the chemical strengthening process. However, excessive Al2O3 can increase the viscosity of the glass and easily lead to the precipitation of other crystalline phases, such as petalite, affecting the crystalline structure of the glass-ceramics. Therefore, in order to obtain the desired crystalline structure and improve the chemical strengthening effect of the glass-ceramics, the molar percentage of Al2O3 in the substrate glass or glass-ceramics is set at 2.75% to 2.99%.

[0137] In some embodiments of the present application, the content of Al2O3 in the substrate glass or glass-ceramics can be 2.75%, 2.77%, 2.79%, 2.81%, 2.83%, 2.85%, 2.86%, 2.87%, 2.89%, 2.91%, 2.93%, 2.94%, 2.95%, 2.97% or 2.99% in terms of molar percentage of oxide, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

[0138] In this application, P2O5 acts as a nucleating agent, promoting uniform nucleation of the glass. Excessive or excessive amounts of P2O5 can result in poor crystallization, affecting the optical properties of the resulting glass-ceramics and reducing their transparency. Therefore, to achieve the desired crystalline structure and, in turn, excellent optical properties and mechanical strength, the molar percentage of P2O5 in the substrate glass or glass-ceramics is set at 0.91% to 1.91%, preferably 1.20% to 1.91%, and more preferably 1.30% to 1.60%.

[0139] In some embodiments of the present application, the content of P2O5 in the substrate glass or microcrystalline glass can be 0.91%, 0.95%, 1.00%, 1.05%, 1.10%, 1.15%, 1.20%, 1.25%, 1.30%, 1.35%, 1.40%, 1.45%, 1.50%, 1.55%, 1.60%, 1.65%, 1.70%, 1.75%, 1.80%, 1.85%, 1.41%, 1.53%, 1.54% or 1.91%, or can be a value within the numerical range consisting of any two of the above specific values ​​as endpoints, as long as the microcrystalline glass or chemically strengthened microcrystalline glass with the required performance of the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the microcrystalline glass or chemically strengthened microcrystalline glass having the required performance of the present application can be obtained.

[0140] In this application, ZrO2 is an intermediate oxide in glass formation. An appropriate amount of ZrO2 can improve the chemical stability of glass-ceramics, increase their hardness, and enhance their scratch and drop resistance. Furthermore, due to the high cationic charge and strong electric field of ZrO2, it has a significant agglomeration effect and is often used as a nucleating agent in glass-ceramics. However, excessive ZrO2 content can cause glass phase separation or hinder the production of glass-ceramics with excellent optical properties. Therefore, in order to obtain glass-ceramics with excellent optical properties and high mechanical strength, the molar percentage of ZrO2 in the substrate glass or glass-ceramics is set to 4.20% to 4.85%, preferably 4.20% to 4.80%.

[0141] In some embodiments of the present application, the content of ZrO2 in the substrate glass or glass-ceramics can be 4.20%, 4.35%, 4.40%, 4.45%, 4.50%, 4.55%, 4.60%, 4.65%, 4.70%, 4.75%, 4.74%, 4.84%, 4.33%, 4.34%, 4.85% or 4.80%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

[0142] In this application, Na2O is a network-external oxide. A suitable amount of Na2O can provide free oxygen, improve the viscosity of the glass, promote the melting and clarification of the glass liquid, and also regulate the chemical strengthening rate. However, excessive Na2O not only reduces the crystallinity of the glass-ceramics but also affects the chemical strengthening effect of the glass-ceramics. Therefore, in order to improve the formability of the substrate glass and the chemical strengthening effect of the glass-ceramics, the molar percentage of Na2O in the substrate glass or glass-ceramics is set to 1.80% to 3.20%, preferably 1.85% to 3.05%, and more preferably 2.20% to 3.00%.

[0143] In some embodiments of the present application, the content of Na2O in the substrate glass or glass-ceramics can be 1.80%, 1.85%, 1.90%, 1.95%, 2.00%, 2.05%, 2.10%, 2.15%, 2.20%, 2.25%, 2.30%, 2.35%, 2.40%, 2.45%, 2.50%, 2.55%, 2.60%, 2.70%, 2.80%, 2.90%, 3.00%, 3.10%, 3.20%, 3.30%, 3.40%, 3.50%, 3.60%, 3.70%, 3.80%, 3.90%, 3.10%, 3.15%, 3.20%, 3.30%, 3.35 ... %, 2.65%, 2.70%, 2.75%, 2.80%, 2.85%, 2.90%, 2.95%, 3.00%, 3.20%, 2.36%, 2.96%, 3.01%, 2.93% or 3.05%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the micro-ceramics or chemically strengthened micro-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the micro-ceramics or chemically strengthened micro-ceramics with the performance required by the present application can be obtained.

[0144] In this application, B2O3, as a flux, can reduce the high-temperature viscosity of the glass, alleviate the melting difficulties caused by ZrO2, and lower the glass's sag temperature. However, excessive B2O3 can easily lead to reduced transparency of the glass-ceramics. Therefore, to improve the formability of the base glass and obtain glass-ceramics with desired properties, the molar percentage of B2O3 in the base glass or glass-ceramics is set to 0-1.00%, preferably 0-0.65%.

[0145] In some embodiments of the present application, the content of B2O3 in the substrate glass or glass-ceramics can be 0, 0.05%, 0.10%, 0.15%, 0.20%, 0.25%, 0.30%, 0.35%, 0.40%, 0.45%, 0.50%, 0.55%, 0.65%, 0.70%, 0.80%, 0.90%, 1.00% or 0.60%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

[0146] In the present application, Li2O is an essential component for forming the main crystalline phase, lithium disilicate, and is also an essential component for providing lithium ions for ion exchange during the chemical strengthening process. An appropriate amount of Li2O not only helps improve the viscosity of the glass and promotes the melting and clarification of the glass liquid, but also helps ensure that the desired content of lithium disilicate crystals is obtained. At the same time, Li2O can also provide alkali metal lithium ions for ion exchange with large-radius ions (such as sodium ions) in the molten salt bath, which is an important factor affecting the stress level that can be obtained by chemically strengthening microcrystalline glass. However, excessive Li2O will deteriorate the optical properties of microcrystalline glass. Therefore, in order to improve the formability of the substrate glass, obtain microcrystalline glass of the desired structure, and improve the chemical strengthening effect of the microcrystalline glass, the molar percentage of Li2O in the substrate glass or microcrystalline glass is 25.32% to 26.52%, preferably 25.52% to 26.52%, and more preferably 25.52% to 26.00%.

[0147] In some embodiments of the present application, the content of Li2O in the substrate glass or glass-ceramics may be 25.32%, 25.52%, 25.60%, 25.65%, 25.70%, 25.75%, 25.80%, 25.85%, 25.90%, 25.95%, 26.00%, 26.05%, 26.10%, 26.15%, 26.20%, 26.25%, 26.30%, 26.35%, 26.40%, 26.50%, 26.60%, 26.70%, 26.80%, 26.90%, 26.95%, 26.00%, 26.05%, 26.10%, 26.15%, 26.20%, 26.25%, 26.30%, 26.40%, 26.50%, 26.60%, 26.70%, 26.80%, 26.90%, 26.95%, 26.00%, 26.05%, 26.10%, 26.15%, 26.20%, 26.25%, 26. 26.30%, 26.35%, 26.40%, 26.45%, 25.62%, 25.82%, 25.69%, 25.36%, 25.77%, 25.87%, 25.79%, 26.03%, 25.74% or 26.52%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the micro-ceramics or chemically strengthened micro-ceramics with the performance required by the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the micro-ceramics or chemically strengthened micro-ceramics with the performance required by the present application can be obtained.

[0148] In the present application, on the basis of adjusting and controlling the content range of each oxide component, by adjusting and controlling the ratio relationship between each oxide component, especially the molar percentage relationship between Na2O, B2O3, ZrO2 or Li2O, it is not only beneficial to ensure that a microcrystalline glass that meets the desired crystal phase structure is obtained, but also beneficial to ensure that the microcrystalline glass obtains excellent optical properties and high intrinsic strength, but also beneficial to ensure that the obtained microcrystalline glass achieves better chemical strengthening effect, so that the microcrystalline glass can be quickly and efficiently produced under conventional chemical strengthening process conditions with a higher stress level and higher mechanical strength performance. Chemically strengthened microcrystalline glass, thereby effectively reducing the manufacturing cost of high-strength chemically strengthened microcrystalline glass.

[0149] In some embodiments of the present application, in the composition of the substrate glass or glass-ceramics, the value of the molar percentage relationship Z between Na2O, B2O3 and ZrO2 can be 4.80, 4.85, 4.90, 4.95, 4.98, 5.05, 5.06, 5.07, 5.08, 5.09, 5.10, 5.11, 5.12, 5.13, 5.14, 5.15, 5.16, 5.17, 5.18, 5.19, 5.35, 5.30 or 5.20, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

[0150] In some embodiments of the present application, in the composition of the substrate glass or microcrystalline glass, the molar percentage of Na2O [Na2O] and the molar percentage of B2O3 [B2O3] satisfy the following relationship: 0.90%≤[Na2O]-[B2O3]≤3.10%, preferably, 1.25%≤[Na2O]-[B2O3]≤3.02%, and more preferably, 2.00%≤[Na2O]-[B2O3]≤3.00%.

[0151] In some embodiments, in the composition of the substrate glass or glass-ceramics, the difference in molar percentage between Na2O and B2O3 [Na2O]-[B2O3] may be 0.90%, 1.00%, 1.20%, 1.25%, 1.26%, 1.35%, 1.45%, 1.55%, 1.65%, 1.75%, 1.85%, 1.95%, 2.00%, 2.05%, 2.15%, 2.25%, 2.3 5%, 2.45%, 2.50%, 2.55%, 2.65%, 2.75%, 2.85%, 2.95%, 3.10%, 1.79%, 0.96%, 2.36%, 2.96%, 3.01%, 2.93%, 3.00% or 3.02%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the micro-ceramics or chemically strengthened micro-ceramics with the performance required by the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the micro-ceramics or chemically strengthened micro-ceramics with the performance required by the present application can be obtained.

[0152] In some embodiments of the present application, in the composition of the substrate glass or microcrystalline glass, the molar percentage of Na2O [Na2O] and the molar percentage of Li2O [Li2O] satisfy the following relationship: 8.55≤[Li2O] / [Na2O]≤13.85, preferably, 8.55≤[Li2O] / [Na2O]≤11.50.

[0153] In some embodiments, in the composition of the substrate glass or glass-ceramics, the molar percentage ratio of Li2O to Na2O [Li2O] / [Na2O] can be 8.55, 9.00, 9.50, 10.00, 10.50, 10.55, 11.00, 11.50, 12.00, 12.50, 13.00, 13.50, 13.83, 10.93, 13.01, 10.92, 8.73, 8.61, 8.79, 8.83 or 13.85, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

[0154] In some embodiments of the present application, the composition of the substrate glass or glass-ceramics may further include other components within the aforementioned composition ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics having the desired properties is achieved. For example, in some embodiments, the composition of the substrate glass or glass-ceramics may further include, by mole percentage of oxides, the following: CaO: 0.00 mol%-1.00 mol%; KO: 0.00 mol%-1.00 mol%.

[0155] In the present application, “lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the glass-ceramic” or “lithium disilicate is the main crystalline phase” or other similar expressions means that the lithium disilicate crystalline phase accounts for more than 70 weight percent (wt%) of all crystalline phases of the glass-ceramic according to the embodiment of the present application. In some embodiments, the weight proportion of the lithium disilicate crystalline phase in all crystalline phases of the glass-ceramic is greater than 70%, and preferably, the weight proportion of the lithium disilicate crystalline phase in all crystalline phases of the glass-ceramic is greater than 85%. For example, in all the crystalline phases of the glass-ceramics, the weight proportion of the lithium disilicate crystalline phase can be 70%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 96%, 97%, 98%, 100% or 95%, or can be a value within the numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the required performance of the present application can be obtained. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the required performance of the present application can be obtained.

[0156] In some embodiments of the present application, the crystallinity of the glass-ceramics is not less than 45%, preferably, the crystallinity of the glass-ceramics is 45% to 85%, and more preferably, the crystallinity of the glass-ceramics is 55% to 65%. The higher the crystallinity of the glass-ceramics, the more conducive it is for the glass-ceramics to obtain high impact resistance and high intrinsic strength. However, excessive crystallinity will not only affect the chemical strengthening effect of the glass-ceramics, thereby prolonging the chemical strengthening time for obtaining chemically strengthened glass-ceramics with a high stress level, but also affect the optical properties of the glass-ceramics. In the present application, by ensuring that the glass-ceramics meet the desired crystallinity, it is beneficial to ensure that the glass-ceramics has excellent optical properties while meeting good impact resistance and high intrinsic strength, and at the same time it is beneficial to improve its chemical strengthening effect.

[0157] In some embodiments of the present application, the crystallinity of the glass-ceramics may be 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85%, or may be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics having the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges may be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

[0158] In some embodiments of the present application, non-limiting examples of other possible crystalline phases in the glass-ceramics include: petalite crystalline phase, and / or, lithium phosphate crystalline phase. In some embodiments, the glass-ceramics further contains petalite crystalline phase, preferably the weight percentage of petalite crystalline phase in the glass-ceramics is ≤20%, more preferably, the weight percentage of petalite crystalline phase in the glass-ceramics can be ≤15%, ≤10%, or ≤5%. In some embodiments, it is preferred that the glass-ceramics does not contain petalite crystalline phase. By controlling the precipitation of other crystalline phases, it is more conducive to ensuring that lithium disilicate forms the desired interlocking structure, thereby ensuring that the glass-ceramics obtains high mechanical strength, excellent optical properties and excellent damage resistance.

[0159] In some embodiments of the present application, in the glass-ceramics, the average grain size does not exceed 100 nm, preferably, the average grain size does not exceed 40 nm, and more preferably, the average grain size is 15 to 30 nm. An appropriate average grain size is beneficial for the glass-ceramics to have both excellent optical properties and high intrinsic strength. If the average grain size is too high, the glass-ceramics will easily lose clarity, and the chemical strengthening effect will also be affected. In the present application, by ensuring that the glass-ceramics meet an appropriate average grain size, it is beneficial to ensure that the glass-ceramics has excellent optical properties while meeting good impact resistance and high intrinsic strength, and at the same time it is beneficial to improve its chemical strengthening effect.

[0160] In some embodiments, the average grain size of the glass-ceramics can be 100 nm, 50 nm, 40 nm, 35 nm, 30 nm, 25 nm, 20 nm, 15 nm, or 10 nm, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics having the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

[0161] In some embodiments of the present application, the glass-ceramics is transparent within the visible light wavelength range. Preferably, at a thickness of 0.70 mm, for light with a wavelength of 550 nm, the glass-ceramics has a transmittance of ≥ 90.00%, preferably > 90.40%. Glass-ceramics meeting this transmittance can ensure good light transmittance and transparency, making them suitable for use in display screens with demanding display effects. The "visible light wavelength range" here refers to light with a wavelength of 360 nm to 740 nm.

[0162] In some embodiments, at a thickness of 0.70 mm, for light with a wavelength of 550 nm, the transmittance of the glass-ceramics may be 90.00%, 90.10%, 90.20%, 90.30%, 90.40%, 90.50%, 91.00%, 90.52%, 90.70%, 90.64%, 90.85%, 90.74%, 90.63%, 90.51% or 92.00%, or may be a value within a numerical range consisting of any two of the above specific values ​​as endpoints. For example, the transmittance of the glass-ceramics may be 90% to 92% or 90.4% to 92%, and so on, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges may be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

[0163] In some embodiments of the present application, at a thickness of 0.70 mm, the haze of the glass-ceramics is less than 0.30%. Haze is the cloudy or turbid appearance of the interior or surface of the glass-ceramics due to light diffusion. The smaller the haze, the better the transparency and display effects of the glass-ceramics. In some embodiments, at a thickness of 0.70 mm, the haze of the glass-ceramics can be 0.25%, 0.20%, 0.15%, 0.10%, 0.05%, 0.21%, 0.14%, 0.12%, 0.14%, 0.16% or 0.30%, or can be a value within the numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0164] In some embodiments of the present application, at a thickness of 0.70 mm, the glass-ceramic has a b-value less than 0.70, preferably ≤ 0.60. In this application, the b-value refers to the optical b-value measured under a D65 illuminant. This application uses a Konica Minolta CM-3600A in transmittance mode to test the b-value, with the results displayed as b(D65). A smaller b-value ensures a better display effect for the glass-ceramic. Excessively large b-values ​​can cause the glass-ceramic to exhibit undesirable colors, resulting in a display that fails to meet the application requirements of display cover glass.

[0165] In some embodiments, at a thickness of 0.70 mm, the b-value of the glass-ceramics may be 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.48, 0.47, 0.52, 0.51, 0.54, or 0.20, or may be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics having the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges may be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

[0166] The microcrystalline glass of the present application has a high transmittance, low haze, and low b value, which all indicate that the optical properties of the microcrystalline glass of the present application are excellent and uniform, and it is in a transparent state, which can meet the application requirements of the cover glass of the electronic device display screen.

[0167] In some embodiments of the present application, the Young's modulus of the glass-ceramics is ≥100 GPa, and preferably, the Young's modulus of the glass-ceramics is 105 to 112.50 GPa. By ensuring that the Young's modulus of the glass-ceramics is not less than 100 GPa, the present application helps ensure a high network strength of the glass-ceramics, helps reduce the stress relaxation effect of the glass-ceramics during ion exchange, and mitigates the weakening effect of factors such as high temperature and long time during ion exchange on deep stress in the composite compressive stress.

[0168] In some embodiments, the Young's modulus of the glass-ceramics can be 100 GPa, 105 GPa, 110 GPa, 106.32 GPa, 111.12 GPa, 110.82 GPa, 111.32 GPa, 110.91 GPa, 112.10 GPa, 111.87 GPa, or 112.50 GPa, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

[0169] In some embodiments of the present application, the Vickers hardness of the glass-ceramics is ≥640 kgf / mm 2 Preferably, the Vickers hardness of the glass-ceramics is 640-680 kgf / mm 2 The Vickers hardness of the glass-ceramics is within the above range, indicating that the glass-ceramics has high hardness and high intrinsic strength, thereby ensuring that it has excellent mechanical properties, which is conducive to ensuring that it can prepare chemically strengthened glass-ceramics with high mechanical strength and excellent damage resistance.

[0170] In some embodiments, the Vickers hardness of the glass-ceramics can be 640 kgf / mm 2 、650kgf / mm 2 、660kgf / mm 2 、670kgf / mm 2 、660.12kgf / mm 2 、654.02kgf / mm 2 、650.20kgf / mm 2 、652.31kgf / mm 2 、659.65kgf / mm 2 、651.70kgf / mm 2 , 654.92 or 680kgf / mm 2, or it can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the properties required by the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics or chemically strengthened glass-ceramics with the properties required by the present application can be obtained.

[0171] In some embodiments, the glass-ceramics include flat glass-ceramics or curved glass-ceramics. Preferably, when the glass-ceramics is a curved glass-ceramics, the glass-ceramics can be made by 3D hot bending processing of a crystallized glass raw material with a crystallinity of not less than 5%. Without being limited to any theory, the present application has found that by using partially crystallized glass raw materials for 3D hot bending, the glass continues to crystallize when heated while being bent and deformed to reach the target crystallinity, which can more accurately control the deformation amount after 3D hot bending, so that the tolerance fluctuation of the contour is small, the size is more stable, and the dimensional accuracy of the curved glass-ceramics after hot bending can be higher. Those skilled in the art can determine the crystallinity of the selected partially crystallized glass raw material according to the crystallinity of the required curved glass-ceramics. For example, when the crystallinity of the required curved glass-ceramics is about 60%, a partially crystallized glass raw material with a crystallinity of 50% can be selected for hot bending processing to obtain a curved glass-ceramics that meets the target crystallinity. In the present application, the composition of the partially crystallized glass is the same or substantially the same as the composition of the microcrystalline glass in terms of molar percentage of oxides.

[0172] In some embodiments, the glass-ceramics has a thickness of 0.10 to 5.00 mm. For example, the glass-ceramics may have a thickness of 0.10 to 2.00 mm, 0.20 to 1.00 mm, or 0.40 to 0.80 mm.

[0173] After introducing the composition and microstructure of microcrystalline glass, the preparation method of microcrystalline glass is introduced in detail below.

[0174] In the present application, the preparation process of glass-ceramics mainly includes: the preparation process of substrate glass and the heat treatment process of substrate glass.

[0175] In this application, the substrate glass can be prepared using conventional molding methods, without limitation. For example, the substrate glass can be molded using methods including, but not limited to, float, overflow, rolling, or casting processes. For example, the substrate glass can be obtained by uniformly mixing the components according to a formula, melting and forming the components, and then cooling and annealing the components.

[0176] Exemplarily, each raw material (conventional industrial raw material) is configured according to the formula ratio, a clarifier is added, and then mixed for a period of time to obtain a uniform raw material mixture. The raw material mixture is placed in a platinum crucible, heated to 1250°C to 1680°C, preferably with a melting temperature of 1480°C to 1680°C, and preferably kept warm at this temperature for 3 to 12 hours, then poured into a molding mold for cooling and molding, preferably cooled to 750°C to 1000°C, and then placed in an annealing furnace for annealing treatment, preferably with an annealing temperature of 400°C to 650°C, and preferably with an annealing time of 10 to 48 hours; then cooled to room temperature with the furnace to obtain the substrate glass. Those skilled in the art can select the type and amount of the clarifier according to their needs, and they do not need to pay creative labor. Furthermore, the clarifier can include but is not limited to one or more of sodium chloride, tin oxide, antimony oxide or arsenic oxide, and the amount of the clarifier added can be 0-1wt% of the total amount of each raw material.

[0177] In some embodiments of the present application, the heat treatment process of the substrate glass may include a nucleation treatment and / or a crystallization treatment, preferably a nucleation treatment and a crystallization treatment. In some embodiments, the crystallization treatment includes a one-step crystallization treatment or a two-step crystallization treatment. In some embodiments, in order to prepare curved microcrystalline glass, a two-step crystallization treatment may be adopted. When a two-step crystallization treatment is adopted, the second step crystallization treatment is to heat the crystallized glass raw material obtained by the first step crystallization treatment to the crystallization temperature and perform a 3D hot bending forming process, and perform a second crystallization during the 3D hot bending forming process.

[0178] In some embodiments of the present application, in order to obtain the desired physicochemical properties of the microcrystalline glass, when the substrate glass is heat-treated, a one-step heat treatment can be performed, or a two-step or multi-step heat treatment can be performed. If a one-step heat treatment is performed, it means that no nucleation treatment (i.e., nucleation treatment) is performed separately, and a one-step heating is performed directly, and nucleation and crystal growth are performed at the temperature reached by the one-step heating process, which can be understood as directly performing a crystallization treatment. If a two-step heat treatment is performed, it means that a two-step heating process is performed, including but not limited to the following methods: first performing a nucleation treatment, i.e., nucleation treatment, and then performing a target crystal growth treatment, i.e., crystallization treatment.

[0179] In order to make the microcrystalline glass precipitate the desired crystalline phase and obtain the desired physical and chemical properties, the temperature of the nucleation treatment can be 530-600°C, and the time of the nucleation treatment can be 0-24h, preferably 2-8h; the temperature of the crystallization treatment can be 700-750°C, and the time of the crystallization treatment can be 0.10-24h, preferably 1-3h. When performing heat treatment, it is preferred to control the heating rate to 5-15°C / min, and more preferably the heating rate to 10°C / min. Among them, the temperature of the nucleation treatment refers to the temperature at which the crystal nucleus can be formed. The temperature of the crystallization treatment refers to the temperature at which the target crystal is suitable for controllable growth.

[0180] After heat treatment, technicians in this field can also perform other conventional steps to obtain microcrystalline glass samples that meet the required specifications or requirements, such as shaping, cutting (such as cutting using a multi-wire cutting machine), CNC machining (computer numerical control, i.e., CNC machine tools), thinning or polishing.

[0181] In some embodiments of the present application, a chemically strengthened microcrystalline glass is further provided, wherein the chemically strengthened microcrystalline glass is obtained by chemically strengthening the aforementioned microcrystalline glass, and the composition at the center of the chemically strengthened microcrystalline glass is the same as the composition of the microcrystalline glass described in any of the aforementioned embodiments. The chemically strengthened microcrystalline glass includes a compressive stress layer region extending from the surface of the chemically strengthened microcrystalline glass to the compression depth, and has tensile stress inside the chemically strengthened microcrystalline glass, that is, the chemically strengthened microcrystalline glass includes a compressive stress layer and a tensile stress layer.

[0182] Chemical strengthening treatment, also known as ion exchange, is achieved by immersing the microcrystalline glass in a molten salt bath, so that the alkali metal ions with smaller ionic radius in the microcrystalline glass are exchanged with the alkali metal ions with larger ionic radius in the molten salt bath, thereby forming a compressive stress layer on the surface of the microcrystalline glass to obtain chemically strengthened microcrystalline glass with better mechanical properties.

[0183] It should be understood that the composition of the surface of the glass-ceramic article after chemical strengthening may be different from the composition of the newly formed glass-ceramic (i.e., the glass-ceramic before chemical strengthening, which has not been ion-exchanged). This is because, during ion exchange, one type of alkali metal ion (e.g., Li+) at the surface of the newly formed glass-ceramic is converted to ions. + Or Na + ) are replaced by larger alkali metal ions (e.g., Na + or K + ) is replaced. However, in the embodiment, the glass composition and phase assembly at or near the depth center of the glass-ceramic product will still have the composition and phase assembly of the newly formed glass-ceramic. That is, in the present application, the composition (e.g., the composition of the tensile stress layer) and phase assembly at the center of the chemically strengthened glass-ceramic that has undergone chemical strengthening treatment are the same or substantially the same as those of the newly formed glass-ceramic.

[0184] In some embodiments of the present application, the chemical strengthening treatment may adopt a single-step strengthening method or a multi-step strengthening method. The molten salt bath for chemical strengthening treatment is a molten salt bath containing sodium salt and / or potassium salt. Preferably, the molten salt bath for chemical strengthening treatment in the present application is a mixed molten salt bath containing sodium salt and potassium salt, and the temperature of the molten salt bath is preferably 380℃~470℃, more preferably 430℃~460℃. In some embodiments of the present application, the concentration of potassium salt in the salt bath is preferably 0wt%~90wt%, and the concentration of sodium salt is 10wt%~100wt%, and more preferably a certain amount (e.g., 0-0.2wt%) of lithium salt is added to the salt bath. In some embodiments of the present application, the time of chemical strengthening treatment is preferably 0.1~3h. Among them, the sodium salt can be selected from at least one of sodium nitrate, sodium sulfate, and sodium carbonate, preferably sodium nitrate; the potassium salt can be selected from at least one of potassium nitrate, potassium sulfate, and potassium carbonate, preferably potassium nitrate; the lithium salt can be selected from at least one of lithium nitrate, lithium sulfate, and lithium carbonate, preferably lithium nitrate.

[0185] In some embodiments of the present application, the chemically strengthened glass-ceramics contains a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the chemically strengthened glass-ceramics; and the composition at the center of the chemically strengthened glass-ceramics includes, in terms of molar percentage of oxides: SiO2: 61.50% to 63.40%, Al2O3: 2.75% to 2.99%, P2O5: 0.91% to 1.91%, ZrO2: 4.20% to 4.85%, Na2O: 1.80% to 3.20%, B2O3: 0 to 1.00%, and Li2O: 25.32% to 26.52%.

[0186] In the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O], the molar percentage of B2O3 [B2O3], and the molar percentage of ZrO2 [ZrO2] satisfy the following relationship:

[0187] Z=-1.344×(2.65-100×[Na2O])2+0.466×100×[B2O3]+1.203×100×[ZrO2], 4.80≤Z≤5.35, preferably, 4.98≤Z≤5.20.

[0188] In some embodiments of the present application, in the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of B2O3 [B2O3] satisfy the following relationship:

[0189] 0.90%≤[Na2O]-[B2O3]≤3.10%, preferably, 1.25%≤[Na2O]-[B2O3]≤3.02%, more preferably, 2.00%≤[Na2O]-[B2O3]≤3.00%; and / or,

[0190] In the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of Li2O [Li2O] satisfy the following relationship:

[0191] 8.55≤[Li2O] / [Na2O]≤13.85, preferably, 8.55≤[Li2O] / [Na2O]≤11.50.

[0192] In some embodiments of the present application, the chemically strengthened glass-ceramics has a CT_LD of 45,000 to 55,000 MPa / mm, where CT_LD represents the tensile stress linear density. Preferably, the chemically strengthened glass-ceramics has a CT_LD of 48,000 to 53,000 MPa / mm. Controlling the CT_LD of the chemically strengthened glass-ceramics to 45,000 to 55,000 MPa / mm helps ensure that the tensile stress stored within the chemically strengthened glass-ceramics is sufficiently dense, thereby ensuring a high surface stress level and excellent damage resistance, such as excellent drop resistance, to meet market demand.

[0193] In some embodiments, the CT_LD of the chemically strengthened glass-ceramics can be 45000 MPa / mm, 46000 MPa / mm, 47000 MPa / mm, 48000 MPa / mm, 49000 MPa / mm, 50000 MPa / mm, 51000 MPa / mm, 52000 MPa / mm, 53000 MPa / mm, 54000 MPa / mm, 50479 MPa / mm, 50547 MPa / mm, 50297 MPa / mm, 50497 MPa / mm, 50833 MPa / mm, 52768 MPa / mm or 55000 MPa / mm, or it can be a value within the numerical range formed by any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics with the performance required by this application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

[0194] In some embodiments of the present application, the chemically strengthened glass-ceramics has a CS_50 of 150 to 199 MPa, preferably 160 to 199 MPa. CS_50 refers to the compressive stress value at a depth of 50 μm measured from the main surface of the chemically strengthened glass-ceramics. When a blunt or sharp object contacts the chemically strengthened glass-ceramics, the stress structure on the surface of the chemically strengthened glass-ceramics will preferentially offset the impact force. By making the chemically strengthened glass-ceramics have a higher surface stress level, it can offset more residual energy from falling, squeezing, impact, or collision, thereby helping to ensure that it has excellent damage resistance, such as excellent drop resistance.

[0195] In some embodiments, the CS_50 of the chemically strengthened glass-ceramics may be 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa, 163.97 MPa, 173.80 MPa, 168.90 MPa, 174.60 MPa, 178.20 MPa, 176.89 MPa, 179.72 MPa, or 199 MPa, or may be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics having the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges may be combined with any other ranges, as long as the chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

[0196] In some embodiments of the present application, the chemically strengthened glass-ceramics has a |CT_AV| of 80 to 98 MPa. |CT_AV| refers to the absolute value of the average tensile stress in the tensile stress layer. By ensuring a |CT_AV| of 80 to 98 MPa, the chemically strengthened glass-ceramics has a more optimal tensile stress distribution structure, resulting in a higher surface stress level. A higher surface compressive stress level can offset more residual energy from drops, squeezes, impacts, or collisions, thereby ensuring the chemically strengthened glass-ceramics' excellent damage resistance.

[0197] In some embodiments, the |CT_AV| of the chemically strengthened glass-ceramics can be 80 MPa, 85 MPa, 90 MPa, 95 MPa, 96.94 MPa, 86.77 MPa, 89.37 MPa, 90.20 MPa, 92.10 MPa, 91.58 MPa, 93.60 MPa, or 98 MPa, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics having the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

[0198] In some embodiments of the present application, the chemically strengthened glass-ceramics has a |CT_CV| of 115 to 142 MPa. |CT_CV| refers to the absolute value of the maximum tensile stress. Preferably, the chemically strengthened glass-ceramics has a |CT_CV| of 120 to 140 MPa. By ensuring a |CT_CV| of 115 to 142 MPa, the chemically strengthened glass-ceramics has a higher surface stress level. A higher surface compressive stress level can offset more residual energy from drops, squeezes, impacts, or collisions, thereby ensuring the chemically strengthened glass-ceramics have excellent damage resistance.

[0199] In some embodiments, the |CT_CV| of the chemically strengthened glass-ceramics can be 115 MPa, 120 MPa, 125 MPa, 130 MPa, 135 MPa, 125.68 MPa, 133.49 MPa, 136.28 MPa, 141.54 MPa, 141.63 MPa, 138.76 MPa, or 142 MPa, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

[0200] In some embodiments of the present application, the Vickers hardness of the chemically strengthened glass-ceramics is ≥680 kgf / mm 2 Preferably, the Vickers hardness of the chemically strengthened glass-ceramics is 700 kgf / mm 2 ~800kgf / mm 2 By making the Vickers hardness of the chemically strengthened glass-ceramics within the above range, the chemically strengthened glass-ceramics can be given high hardness and high mechanical strength, thereby ensuring that it has excellent damage resistance.

[0201] In some embodiments, the Vickers hardness of the chemically strengthened glass-ceramics can be 680 kgf / mm 2 、690kgf / mm 2 , 700kgf / mm 2 、710kgf / mm 2 、720kgf / mm 2 , 730kgf / mm 2 , 740kgf / mm 2 , 750kgf / mm 2 、760kgf / mm 2 、770kgf / mm 2、780kgf / mm 2 、790kgf / mm 2 、726.25kgf / mm 2 、723.96kgf / mm 2 、724.50kgf / mm 2 、720.31kgf / mm 2 、730.98kgf / mm 2 、718.60kgf / mm 2 、731.57kgf / mm 2 or 800kgf / mm 2 , or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics with the properties required by the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the chemically strengthened glass-ceramics with the properties required by the present application can be obtained.

[0202] In some embodiments of the present application, the chemically strengthened glass-ceramics has a DOL_0 of 0.18t to 0.25t, where DOL_0 represents the depth of the compressive stress layer and t represents the thickness of the chemically strengthened glass-ceramics. Preferably, the chemically strengthened glass-ceramics has a DOL_0 of 0.20t to 0.25t. By ensuring that the chemically strengthened glass-ceramics have an appropriate DOL_0, it is possible to prevent sudden cracks from penetrating directly through the compressive stress region to the tensile stress region when blunt or sharp objects impact or pierce the glass-ceramics, thereby improving the chemically strengthened glass-ceramics' ability to offset the energy driving crack propagation, thereby ensuring that the chemically strengthened glass-ceramics has excellent damage resistance, such as excellent drop resistance.

[0203] In some embodiments, the DOL_0 of the chemically strengthened glass-ceramics may be 0.18t, 0.20t, 0.21t, 0.22t, 0.23t, 0.24t, or 0.25t, or may be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics having the desired properties of the present application is obtained. It should be understood that, in specific embodiments, any of the above ranges may be combined with any other ranges, as long as the chemically strengthened glass-ceramics having the desired properties of the present application is obtained. Illustratively, when the thickness of the chemically strengthened glass-ceramics is 0.7 mm, the DOL_0 of the chemically strengthened glass-ceramics can be 152.94 μm, 142.25 μm, 143.26 μm, 144.20 μm, 143.80 μm, 142.67 μm, 144.26 μm, 126 μm, 130 μm, 135 μm, 140 μm, 150 μm or 160 μm, or it can be a value within the numerical range formed by any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics with the performance required by this application can be obtained.

[0204] In some embodiments of the present application, the glass-ceramics or chemically strengthened glass-ceramics can be 2D, 2.5D, 3D, or a special shape; and / or, the glass-ceramics or chemically strengthened glass-ceramics can be of uniform or unequal thickness. Those skilled in the art can make this choice based on their needs. "Unequal thickness" here means that the glass-ceramics or chemically strengthened glass-ceramics contains at least two portions of different thicknesses.

[0205] In the present application, by making the chemically strengthened microcrystalline glass meet specific stress characteristics, it can be ensured that the chemically strengthened microcrystalline glass has excellent mechanical strength properties, excellent mechanical strength properties and excellent damage resistance, especially excellent drop damage resistance.

[0206] In some embodiments of the present application, a sandpaper drop resistance test was conducted on the chemically strengthened glass-ceramics with a thickness of 0.7 mm using 80-grit sandpaper. The average sandpaper drop resistance height of the chemically strengthened glass-ceramics was ≥1.0 m, preferably ≥1.2 m, and more preferably ≥1.5 m. This indicates that the chemically strengthened glass-ceramics of the present application have excellent drop resistance. In some embodiments, 80-grit sandpaper is used to perform a sandpaper drop resistance test on the chemically strengthened microcrystalline glass with a thickness of 0.7 mm. The average sandpaper drop resistance height of the chemically strengthened microcrystalline glass can be 1.0 m, 1.1 m, 1.2 m, 1.3 m, 1.4 m, 1.5 m, 1.6 m, 1.7 m, 1.8 m, 1.9 m, 2.0 m, 1.75 m, 1.68 m, 1.64 m, 1.57 m, 1.60 m, 1.62 m, 1.78 m or 2.1 m, etc.

[0207] The microcrystalline glass or chemically strengthened microcrystalline glass with excellent performance provided by the present application can be used in electronic devices, including but not limited to mobile phones, tablet computers, handheld game consoles, portable digital devices (such as digital cameras), vehicle-mounted central control, electronic whiteboard glass, smart home, smart wearable (such as smart bracelets, smart watches, smart glasses), and can also be used in vehicles, aircraft or aircraft, and can also be used in any glass device of microcrystalline glass required. For example, it can be used for display screens, cover glass, touch screens, glass inner screens or inner frames of electronic devices; for example, it can be used for windshields of vehicles, aircraft or aircraft, such as front windshields or side windshields. For example, it can be used for worktops, other surfaces, appliance doors, floor tiles, wall panels or storage containers. Other surfaces can include but are not limited to exterior wall surfaces, stair tread surfaces, column veneers or counter surfaces, and storage containers can include but are not limited to cups, plates, medicine bottles or beverage bottles.

[0208] For example, the glass-ceramics or chemically strengthened glass-ceramics with excellent performance provided herein can be used to manufacture glass devices. The glass devices referred to herein can be regular or irregular, and those skilled in the art can manufacture them according to their needs.

[0209] Exemplarily, the microcrystalline glass or chemically strengthened microcrystalline glass with excellent performance provided by the present application can be used to manufacture cover glass, and the cover glass can be a display cover, back cover or camera protection cover of an electronic device. Exemplarily, the microcrystalline glass or chemically strengthened microcrystalline glass with excellent performance provided by the present application can be used in electronic devices. Referring to Figures 9, 10 and 11, an embodiment of the present application provides an electronic device, which can be a mobile phone, a tablet computer, a smart wearable device or other electronic product, and the electronic device includes a housing 1 assembled on the outside of the electronic device, and components such as a circuit board and a battery located inside the housing 1. The housing 1 includes a display cover 11 assembled on the front side and a back cover 12 assembled on the back side. The display cover 11 is covered on the display module 4, wherein the display cover 11 and / or the back cover 12 can be made of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass. In the embodiment of the present application, the display cover 11 and the back cover 12 can be made entirely of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass, or they can be made only partially of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass. In the embodiment of the present application, the display screen may be a touch screen display screen, and the display screen cover 11 may be a protective cover plate provided on the touch screen display screen. In the embodiment of the present application, the back cover 12 may cover only the back side of the electronic device (i.e., the side facing away from the display screen), or may cover both the back side and the side frame of the electronic device. Optionally, the back cover 12 may cover all side frames around the electronic device, or may cover only part of the side frames.

[0210] In some embodiments of the present application, as shown in Figure 10, the electronic device also includes a camera assembly 2 located inside the housing 1, and the housing 1 may include a camera protection cover 13. The camera protection cover 13 is provided on the camera assembly 2 to protect the camera assembly 2. The camera protection cover 13 may be made of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass. In the embodiment of the present application, the camera protection cover 13 may be partially made of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass, or may be made of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass. In the embodiment of the present application, the setting position of the camera protection cover 13 is determined according to the setting position of the camera assembly 2. It may be located on the front side of the electronic device or on the back side of the electronic device. In some embodiments of the present application, the camera protection cover 13 may be a separate structure from the display screen cover 11 or the back cover 12. In other embodiments of the present application, the camera protection cover 13 may also be an integrated structure with the display screen cover 11 or the back cover 12.

[0211] In some embodiments of the present application, as shown in FIG11 , the electronic device further includes a middle frame 3 located between the display module 4 and the housing 1 , and the middle frame 3 may include the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass.

[0212] In the embodiment of the present application, the display screen cover, back cover, camera protection cover, and middle frame in the electronic device can be any one of the four using the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass, or any two of them can be using the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass, or all three can be using the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass, or all four can be using the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass.

[0213] In some embodiments of the present application, the display screen cover, back cover, camera protection cover, or middle frame of the electronic device may be 2D, 2.5D, 3D, or a special shape. In some embodiments of the present application, the display screen cover, back cover, camera protection cover, or middle frame of the electronic device may be of uniform or unequal thickness.

[0214] Those skilled in the art can select the thickness of the glass-ceramics or chemically strengthened glass-ceramics according to needs. For example, the thickness of the glass-ceramics or chemically strengthened glass-ceramics can be 0.1-5 mm, 0.1-2.0 mm, 0.2-1 mm or 0.4-0.8 mm.

[0215] The technical solution of the present application is further described in detail below in conjunction with the embodiments. The embodiments of the present application described in detail below are exemplary and are only used to explain the present application, and should not be understood as limiting the present application.

[0216] Example 1

[0217] (1) Preparation of substrate glass:

[0218] The raw materials (conventional industrial raw materials) were prepared according to the formula ratio in Table 1. The total mass of the prepared raw materials was 1000 g. 5 g of clarifier sodium chloride (NaCl) was added to the prepared raw materials, and then mixed in a V-type mixer for 30 minutes to obtain a uniform raw material mixture.

[0219] The raw material mixture is transferred to a platinum crucible, and then melted in a platinum crucible at 1650°C for 5 hours, and then poured into a forming mold for forming and cooling. After cooling to 900°C, it is placed in a 500°C annealing furnace for annealing for 24 hours, and then cooled to room temperature with the furnace to obtain the base material glass brick.

[0220] (2) Preparation of glass-ceramics: The base glass brick was placed in an annealing furnace and heated from room temperature to 550°C at a rate of 10°C / min for nucleation treatment. After being kept at this temperature for 4 hours, the temperature was then increased to 710°C at a rate of 10°C / min for crystallization treatment. The temperature was kept at this temperature for 1.5 hours, and then cooled to room temperature at a rate of 1°C / min to obtain a glass-ceramic sample brick. The composition of the prepared glass-ceramics was the same as that of the base glass in terms of molar percentage of oxides, as shown in Table 1.

[0221] The obtained glass-ceramic bricks are subjected to cold working processes such as cutting, CNC machining (the CNC equipment model used in this application is RCG500S), and polishing to produce glass-ceramic samples that meet the required specifications and requirements. In this application, the glass-ceramic bricks are subjected to the aforementioned cold working processes to produce glass-ceramic samples with a thickness of 0.70 mm, specifically, 50 mm × 50 mm × 0.70 mm glass-ceramic polished sheet samples.

[0222] The glass-ceramics sample obtained in Example 1 was tested as follows:

[0223] The crystal phase composition, crystallinity, average grain size, Vickers hardness, Young's modulus of the microcrystalline glass sample, as well as the optical b value, haze and transmittance (under 550nm wavelength light) of the microcrystalline glass sample with a thickness of 0.7mm were tested respectively, and the results are shown in Table 2.

[0224] (3) Preparation of chemically strengthened microcrystalline glass: The obtained microcrystalline glass sample is placed in the strengthening furnace cavity for preheating for 5 minutes, and then quickly placed in a molten salt bath at 460°C for chemical strengthening treatment. The composition of the molten salt is 70wt% KNO3+30wt% NaNO3+0.03wt% LiNO3 (based on the total mass of KNO3 and NaNO3, adding 0.03wt% LiNO3). After chemical strengthening treatment for 2 hours, the microcrystalline glass sample is taken out and placed on the strengthening furnace body to slowly cool to room temperature. The salt wrapped on the surface of the microcrystalline glass is washed off with clean water. After the microcrystalline glass sample is dried, the chemically strengthened microcrystalline glass can be obtained.

[0225] The chemically strengthened glass-ceramics obtained in Example 1 were tested as follows:

[0226] I. The chemically strengthened glass-ceramics were measured using an SLP 2000 stress meter (using a light source wavelength of 518 nm, SOC = 26 (nm / cm) / MPa, a refractive index of 1.56, and an exposure time of 300 μsec). |CT_CV|, DOL_0, CS_50, and |CT_AV| were measured. The tensile stress linear density (CT_LD) was then calculated. The results are shown in Table 3.

[0227] II. The Vickers hardness of the chemically strengthened glass-ceramics was tested. The results are shown in Table 3.

[0228] III. The average sandpaper drop height of the chemically strengthened glass-ceramics was tested. The results are shown in Table 3.

[0229] Example 2-Example 7

[0230] The above steps are respectively carried out with reference to Example 1, except that the raw material composition, different process parameters and corresponding test results of each example are shown in Tables 1 to 3, respectively.

[0231] The XRD spectrum of the glass-ceramics of Example 2 is shown in FIG1 . It can be seen from the figure that the main crystalline phase in the glass-ceramics is the lithium disilicate crystalline phase.

[0232] The transmittance curve of the glass-ceramics of Example 2 is shown in FIG2 . As can be seen from the figure, the glass-ceramics is transparent in the visible light range and has a high transmittance.

[0233] The XRD spectrum comparison of the microcrystalline glass of Example 2 before and after chemical strengthening is shown in Figure 3. It can be seen from the figure that the crystal phase structure of the microcrystalline glass has not changed significantly before and after the chemical strengthening treatment, and the main crystal phase of the chemically strengthened microcrystals made from the microcrystalline glass is also the lithium disilicate crystal phase.

[0234] Actual images of the glass-ceramics of Examples 2 and 7 are shown in Figures 4 and 5, respectively. To illustrate the state of the glass-ceramics, these images were taken on paper with a black background. As can be seen from the images, the glass-ceramics of this application are essentially transparent and colorless due to their low b-value, enabling a good display effect.

[0235] Comparative Example 1-Comparative Example 12

[0236] The above methods are respectively carried out with reference to Example 1, except that the raw material composition, different process parameters and corresponding test results of each comparative example are shown in Tables 1 to 3, respectively.

[0237] Figures 6, 7, and 8 show the actual glass-ceramics of Comparative Examples 5, 6, and 8, respectively. To illustrate the glass-ceramics' state, the images were taken on a black background. As can be seen from the images, the glass-ceramics of the comparative examples exhibit a noticeable bluish tint due to their relatively high b-values. The larger the b-value, the more pronounced the blue tint, and the greater its impact on the display quality.

[0238] Table 1

[0239] Note: Oxide contents marked "0" in Table 1 indicate that the component was not intentionally or deliberately added to the glass composition during the initial batching process, but may be present as an impurity. The percentages in the table are based on the moles of the oxides used in the formulas; molar units are not used in the calculations.

[0240] Table 2

[0241] Table 3

[0242] It can be seen from the embodiments and comparative examples in Tables 1 to 3 above that, compared with the comparative examples, the embodiment scheme of the present application is adopted, by controlling the various components and proportions of the microcrystalline glass, while satisfying the content range of each oxide, the molar percentage relationship between Na2O, B2O3, ZrO2 or Li2O is controlled to meet the specific range requirements, and at the same time, the microcrystalline glass forms a microstructure with lithium disilicate as the main crystalline phase, which not only gives the microcrystalline glass excellent optical properties (such as high transmittance, low haze and low b value) and high intrinsic strength (such as high Young's modulus and high Vickers hardness), but also can ensure that the microcrystalline glass can be quickly and efficiently prepared under conventional chemical strengthening process conditions. Chemically strengthened microcrystalline glass with high stress level and high mechanical strength performance, the chemically strengthened microcrystalline glass prepared in the embodiment of the present application has high CS_50, |CT_AV|, DOL_0 and CT_LD, and has excellent drop resistance.

[0243] In contrast, the glass formulations of Comparative Examples 1-12 do not simultaneously meet the requirements of the present application for the content of each oxide, as well as the molar percentage relationships between Na2O, B2O3, ZrO2, or Li2O. Consequently, in each of the comparative examples, either the optical properties of the resulting glass-ceramics are poor, such as low transmittance, high optical b-values, or high haze; or, under the same chemical strengthening process conditions, the stress performance of the chemically strengthened glass-ceramics produced is inferior to that of the embodiment, resulting in poor drop resistance. In other words, because the comparative examples do not simultaneously meet the requirements of the present application, they cannot simultaneously achieve both excellent optical properties and high stress levels.

[0244] The above are merely specific embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application. Industrial Applicability

[0245] The present application makes the microcrystalline glass meet specific composition and crystal phase structure, makes the content of each component of the microcrystalline glass and the ratio of the content of each component meet specific ranges, makes Na2O, B2O3, ZrO2 or Li2O meet specific molar percentage relationships, and makes the microcrystalline glass meet the requirement of lithium disilicate as the main crystal phase. This not only gives the microcrystalline glass excellent optical properties and high intrinsic strength, but also enables the microcrystalline glass to be quickly and efficiently produced with high stress levels and high mechanical strength properties under conventional chemical strengthening process conditions, thereby effectively reducing the manufacturing cost of high-strength chemically strengthened microcrystalline glass.

Claims

1. A glass-ceramic, characterized in that: The glass-ceramics contains a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the glass-ceramics; Calculated by molar percentage of oxides, the components of the microcrystalline glass include: SiO2: 61.50% to 63.40%, Al2O3: 2.75% to 2.99%, P2O5: 0.91% to 1.91%, ZrO2: 4.20% to 4.85%, Na2O: 1.80% to 3.20%, B2O3: 0 to 1.00% and Li2O: 25.32% to 26.52%; and in the composition of the microcrystalline glass, the molar percentage of Na2O [Na2O], the molar percentage of B2O3 [B2O3] and the molar percentage of ZrO2 [ZrO2] satisfy the following relationship: Z=-1.344×(2.65-100×[Na2O]) 2 +0.466×100×[B2O3]+1.203×100×[ZrO2], 4.80≤Z≤5.35, preferably, 4.98 ≤Z≤5.20。 2. The glass-ceramic according to claim 1, characterized in that In the composition of the microcrystalline glass, the molar percentage of Na2O [Na2O] and the molar percentage of B2O3 [B2O3] satisfy the following relationship: 0.90%≤[Na2O]-[B2O3]≤3.10%, preferably, 1.25%≤[Na2O]-[B2O3]≤3.02%, and more preferably, 2.00%≤[Na2O]-[B2O3]≤3.00%.

3. The glass-ceramics according to claim 1 or 2, characterized in that: In the composition of the microcrystalline glass, the molar percentage of Na2O [Na2O] and the molar percentage of Li2O [Li2O] satisfy the following relationship: 8.55≤[Li2O] / [Na2O]≤13.85, preferably, 8.55≤[Li2O] / [Na2O]≤11.

50.

4. The glass-ceramic according to any one of claims 1 to 3, characterized in that Among all the crystal phases of the glass-ceramics, the weight proportion of the lithium disilicate crystal phase is greater than 70%. Preferably, among all the crystal phases of the glass-ceramics, the weight proportion of the lithium disilicate crystal phase is greater than 85%.

5. The glass-ceramic according to any one of claims 1 to 4, characterized in that: Measured in terms of molar percentage of oxides, in the glass-ceramics: The molar percentage of SiO2 is 61.50% to 63.30%, preferably, the molar percentage of SiO2 is 62.00% to 62.60%; and / or, The molar percentage of P2O5 is 1.20% to 1.91%, preferably, the molar percentage of P2O5 is 1.30% to 1.60%; and / or, The molar percentage of Na2O is 1.85% to 3.05%, preferably, the molar percentage of Na2O is 2.20% to 3.00%; and / or, The molar percentage of B2O3 is 0 to 0.65%; and / or, the molar percentage of ZrO2 is 4.20% to 4.80%; and / or, The molar percentage of Li2O is 25.52% to 26.52%, and preferably, the molar percentage of Li2O is 25.52% to 26.00%.

6. The glass-ceramic according to any one of claims 1 to 4, characterized in that: Measured in terms of molar percentage of oxides, in the glass-ceramics: The molar percentage of SiO2 is 62.88%, 63.30%, 62.50%, 63.26%, 62.38%, 62.27%, 62.45%, 62.22% or 63.17%; and / or, The molar percentage of Al2O3 is 2.86%, 2.87%, 2.93%, 2.94% or 2.99%; and / or, The mole percentage of P2O5 is 1.00%, 1.20%, 1.30%, 1.60%, 1.40%, 1.41%, 1.53% or 1.54%; and / or, The molar percentage of ZrO2 is 4.80%, 4.74%, 4.84%, 4.33%, 4.34% or 4.35%; and / or, The molar percentage of Na2O is 1.85%, 2.35%, 1.95%, 2.36%, 2.96%, 3.01%, 2.93% or 2.95%; and / or, The molar percentage of Li2O is 25.62%, 25.82%, 25.69%, 25.36%, 25.77%, 25.87%, 25.90%, 25.79%, 26.03% or 25.74%.

7. The glass-ceramics according to any one of claims 1 to 6, characterized in that: The composition of the glass-ceramics satisfies the following requirements, expressed in terms of the content expressed as a molar percentage of oxides: The value of formula Z is 5.19, 5.10, 5.09, 5.06 or 5.13; and / or, The value of [Na2O]-[B2O3] is 1.26%, 1.79%, 0.96%, 2.36%, 2.96%, 3.01%, 2.93% or 2.95%; and / or, The value of [Li2O] / [Na2O] is 13.83, 10.93, 13.01, 10.92, 8.73, 8.61, 8.79 or 8.

83.

8. The glass-ceramic according to any one of claims 1 to 7, characterized in that: The crystallinity of the glass-ceramics is not less than 45%, preferably, the crystallinity of the glass-ceramics is 45% to 85%, more preferably, the crystallinity of the glass-ceramics is 55% to 65%; and / or, In the glass-ceramics, the average grain size does not exceed 100 nm, preferably, the average grain size does not exceed 40 nm, and more preferably, the average grain size is 15 to 30 nm.

9. The glass-ceramic according to any one of claims 1 to 8, characterized in that: The microcrystalline glass is transparent in the visible light wavelength range. Preferably, at a thickness of 0.70 mm, for light with a wavelength of 550 nm, the transmittance of the microcrystalline glass is ≥90.00%, preferably the transmittance is >90.40%; and / or, at a thickness of 0.7 mm, the haze of the microcrystalline glass is <0.30%.

10. The glass-ceramic according to any one of claims 1 to 9, characterized in that: At a thickness of 0.70 mm, the b value of the glass-ceramics is less than 0.70, and preferably, the b value is ≤ 0.

60.

11. The glass-ceramic according to any one of claims 1 to 10, characterized in that: The Young's modulus of the glass-ceramics is ≥100 GPa, preferably, the Young's modulus of the glass-ceramics is 105 to 112.50 GPa; and / or, The Vickers hardness of the glass-ceramics is ≥640 kgf / mm 2 Preferably, the Vickers hardness of the glass-ceramics is 640-680 kgf / mm 2 .

12. The glass-ceramic according to any one of claims 1 to 11, characterized in that: The glass-ceramics includes flat glass-ceramics or curved glass-ceramics; preferably, when the glass-ceramics is curved glass-ceramics, the glass-ceramics can be made by subjecting a crystallized glass raw material having a crystallinity of not less than 5% to a 3D hot bending process.

13. The glass-ceramic according to any one of claims 1 to 12, characterized in that: The microcrystalline glass is made by heat treatment of substrate glass. Preferably, the heat treatment process includes nucleation treatment and / or crystallization treatment. Preferably, the crystallization treatment includes one-step crystallization treatment or two-step crystallization treatment. Preferably, curved microcrystalline glass can be prepared by two-step crystallization treatment. When a two-step crystallization treatment is adopted, the second step crystallization treatment is to heat the crystallized glass raw material obtained by the first step crystallization treatment to the crystallization temperature and perform 3D hot bending forming treatment.

14. A chemically strengthened glass-ceramic, characterized in that: The composition at the center of the chemically strengthened glass-ceramics is the same as the composition of the glass-ceramics according to any one of claims 1 to 13, and the chemically strengthened glass-ceramics includes a compressive stress layer and a tensile stress layer.

15. The chemically strengthened glass-ceramics according to claim 14, wherein: The chemically strengthened glass-ceramics contains a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the chemically strengthened glass-ceramics; the components at the center of the chemically strengthened glass-ceramics include, in terms of molar percentage of oxides: SiO2: 61.50% to 63.40%, Al2O3: 2.75% to 2.99%, P2O5: 0.91% to 1.91%, ZrO2: 4.20% to 4.85%, Na2O: 1.80% to 3.20%, B2O3: 0% to 1.00%, and Li2O: 25.32% to 26.52%. In the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O], the molar percentage of B2O3 [B2O3], and the molar percentage of ZrO2 [ZrO2] satisfy the following relationship: Z=-1.344×(2.65-100×[Na2O]) 2 +0.466×100×[B2O3]+1.203×100×[ZrO2], 4.80≤Z≤5.35, preferably, 4.98 ≤Z≤5.20。 16. The chemically strengthened glass-ceramics according to claim 14 or 15, characterized in that: In the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of B2O3 [B2O3] satisfy the following relationship: 0.90% ≤ [Na2O] - [B2O3] ≤ 3.10%, preferably, 1.25% ≤ [Na2O] - [B2O3] ≤ 3.02%, more preferably, 2.00% ≤ [Na2O] - [B2O3] ≤ 3.00%; and / or, In the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of Li2O [Li2O] satisfy the following relationship: 8.55≤[Li2O] / [Na2O]≤13.85, preferably, 8.55≤[Li2O] / [Na2O]≤11.

50.

17. The chemically strengthened glass-ceramics according to any one of claims 14 to 16, characterized in that: The chemically strengthened glass-ceramics has a CT_LD of 45,000 to 55,000 MPa / mm, where CT_LD is a tensile stress linear density. Preferably, the chemically strengthened glass-ceramics has a CT_LD of 48,000 to 53,000 MPa / mm; and / or The chemically strengthened glass-ceramics has a DOL_0 of 0.18t to 0.25t, where DOL_0 is a depth of a compressive stress layer and t is a thickness of the chemically strengthened glass-ceramics. Preferably, the chemically strengthened glass-ceramics has a DOL_0 of 0.20t to 0.25t; and / or The chemically strengthened glass-ceramics has a CS_50 of 150 to 199 MPa, where CS_50 refers to the compressive stress value at a depth of 50 μm from the main surface of the chemically strengthened glass-ceramics. Preferably, the chemically strengthened glass-ceramics has a CS_50 of 160 to 199 MPa; and / or The chemically strengthened glass-ceramics has a |CT_AV| of 80 to 98 MPa, where |CT_AV| is the absolute value of the average tensile stress; and / or, The chemically strengthened glass-ceramics has a |CT_CV| of 115 to 142 MPa, where |CT_CV| is an absolute value of the maximum tensile stress. Preferably, the chemically strengthened glass-ceramics has a |CT_CV| of 120 to 140 MPa.

18. The chemically strengthened glass-ceramics according to any one of claims 14 to 17, characterized in that The Vickers hardness of the chemically strengthened glass-ceramics is greater than or equal to 680 kgf / mm 2 Preferably, the Vickers hardness of the chemically strengthened glass-ceramics is 700 kgf / mm 2 ~800kgf / mm 2 .

19. A cover glass, characterized in that: The cover glass includes the glass-ceramics according to any one of claims 1 to 13 or the chemically strengthened glass-ceramics according to any one of claims 14 to 18.

20. An electronic device, characterized in that: The electronic device includes the glass-ceramics according to any one of claims 1 to 13 or includes the chemically strengthened glass-ceramics according to any one of claims 14 to 18.

21. The electronic device according to claim 20, characterized in that The electronic device includes a housing assembled on the outside of the electronic device and a circuit board located inside the housing, wherein the housing includes the microcrystalline glass according to any one of claims 1 to 13 or the chemically strengthened microcrystalline glass according to any one of claims 14 to 18.

22. The electronic device according to claim 21, wherein: The housing includes a display cover assembled on the front side of the electronic device, and the display cover includes the glass-ceramics according to any one of claims 1 to 13 or the chemically strengthened glass-ceramics according to any one of claims 14 to 17.

23. The electronic device according to claim 21 or 22, characterized in that: The housing includes a back cover assembled on the back side of the electronic device, and the back cover includes the glass-ceramic according to any one of claims 1 to 13 or the chemically strengthened glass-ceramic according to any one of claims 14 to 18.

24. The electronic device according to any one of claims 21 to 23, characterized in that: The electronic device also includes a camera assembly located inside the housing, the housing includes a camera protection cover, the camera protection cover is covered on the camera assembly, and the camera protection cover includes the microcrystalline glass as described in any one of claims 1-13 or the chemically strengthened microcrystalline glass as described in any one of claims 14-18.

25. The electronic device according to any one of claims 20 to 24, characterized in that: The electronic device further includes a middle frame, wherein the middle frame includes the micro-ceramic glass according to any one of claims 1 to 13 or the chemically strengthened micro-ceramic glass according to any one of claims 14 to 18.