WO2025214396A1 - Chemically strengthened microcrystalline glass, cover glass, electronic device, and glass article - Google Patents

Abstract

A chemically strengthened microcrystalline glass, a cover glass, an electronic device, and a glass article, relating to the technical field of microcrystalline glass. An ultra-thin chemically strengthened microcrystalline glass having a thickness of 0.38-0.60 mm is configured to meet specific crystalline phase structural and stress structural requirements, so that the microcrystalline glass has good resistance to penetration by sharp objects and good resistance to drop damage on rough surfaces. In addition, the chemically strengthened microcrystalline glass further maintains good optical properties, and can satisfy application requirements for protective cover glass for an electronic device.

Description

Chemically strengthened microcrystalline glass, cover glass, electronic equipment and glass device

Cross-reference to related applications

This application claims priority to Chinese patent application No. 202410436177.X filed with the State Intellectual Property Office of China on April 11, 2024, entitled “A chemically strengthened microcrystalline glass, cover glass, electronic device and glass device”, the entire contents of which are incorporated by reference into this application.

Technical Field

The present application relates to the technical field of microcrystalline glass, and in particular to a chemically strengthened microcrystalline glass, cover glass, electronic equipment and glass devices.

Background Art

In recent years, with the continuous development of the electronic products industry, the market requirements for the performance of cover glass materials for electronic equipment have gradually increased. In response to this, the cover industry has successively launched chemically strengthened microcrystalline glass with superior mechanical strength to improve the problem of easy damage to cover glass, such as falling and shattering, puncture, scratches, etc.

Driven by the market demand for larger screens and thinner electronic devices, the thickness of cover glass materials has been required to be thinner and thinner, making ultra-thin cover glass an important development trend. However, with the reduction in thickness, the existing chemically strengthened microcrystalline glass used as cover glass generally has a significantly increased probability of damage, resulting in its inability to meet higher application requirements. In particular, when electronic devices (such as mobile phones, tablets, etc.) are accidentally dropped on gravel or asphalt roads with sharp protrusions, the thinner cover glass used in its screen is very likely to collide with sharp protruding objects, be penetrated by sharp protruding objects, or even pierce and shatter, which will not only directly affect the appearance of the electronic device screen, but also affect its normal use.

Therefore, in order to meet the market demand for thinness and lightness, it is necessary to develop a chemically strengthened microcrystalline glass with excellent damage resistance, especially to make it have excellent resistance to penetration by sharp objects and excellent resistance to drop and breakage, so as to reduce the probability of surface damage and breakage of the screen cover glass of electronic equipment due to impact or penetration by sharp objects, thereby ensuring the safe and stable operation of electronic equipment.

It should be noted that this part of the content of this application only provides background technology related to this application, and does not necessarily constitute prior art or public knowledge.

Summary of the Invention

The present application provides a chemically strengthened microcrystalline glass and a cover glass, an electronic device and a glass device comprising the chemically strengthened microcrystalline glass. The chemically strengthened microcrystalline glass can have both excellent resistance to penetration by sharp objects and excellent resistance to drop damage at an ultra-thin thickness.

Specifically, the technical solutions provided in this application include:

In a first aspect, a chemically strengthened glass-ceramics is provided, wherein the chemically strengthened glass-ceramics comprises a petalite crystalline phase and a lithium disilicate crystalline phase, wherein the petalite crystalline phase and the lithium disilicate crystalline phase have a higher mass percentage than other crystalline phases present in the chemically strengthened glass-ceramics;

The thickness t of chemically strengthened glass-ceramics is 0.38mm to 0.60mm;

Chemically strengthened glass-ceramics have a compressive stress layer on the surface and tensile stress inside. Chemically strengthened glass-ceramics meet the following requirements:
0.18≤DOL_0/t≤0.25,

Preferably, More preferably,

Where DOL_0 is the depth of the compressive stress layer, t is the thickness of the chemically strengthened glass-ceramics, h is the depth from the main surface of the chemically strengthened glass-ceramics, and CS(h) is the compressive stress value at the depth h. It is the integral of the compressive stress from any main surface of the chemically strengthened glass-ceramics to the compressive stress layer with a depth of 80 μm from the main surface.

This application improves the problem that the existing chemically strengthened microcrystalline glass needs to be improved in terms of resistance to penetration by sharp objects and resistance to damage from falling on rough surfaces after the thickness is thinned by making the thinner chemically strengthened microcrystalline glass meet specific crystal phase structure and stress structure. It gives the ultra-thin chemically strengthened microcrystalline glass excellent resistance to penetration by sharp objects and excellent resistance to damage from falling, and at the same time ensures that the chemically strengthened microcrystalline glass maintains excellent optical properties, so as to meet the application requirements of cover glass for screen protection of electronic devices.

As an optional embodiment, chemically strengthened glass-ceramics meets the following requirements:

Preferably, More preferably, Where |CT_AV| is the absolute value of the average tensile stress, expressed in MPa. By ensuring that thinner chemically strengthened glass-ceramics meet a specific stress structure, this stress structure improves mechanical strength, ultimately enabling the chemically strengthened glass-ceramics to achieve superior damage resistance.

As an optional embodiment, chemically strengthened glass-ceramics meets the following requirements:

100 MPa≤|CT_AV|, preferably, 110 MPa≤|CT_AV|, wherein |CT_AV| is the absolute value of the average tensile stress; and/or,

90 μm≤DOL_0, preferably, 90 μm≤DOL_0≤120 μm, more preferably, 105 μm≤DOL_0≤118 μm, wherein DOL_0 is the depth of the compressive stress layer; and/or,

55,000 MPa/mm ≤ CT_LD, preferably 56,400 MPa/mm ≤ CT_LD ≤ 72,000 MPa/mm, and more preferably 62,000 MPa/mm ≤ CT_LD ≤ 65,000 MPa/mm, where CT_LD is the tensile stress linear density. By ensuring that the chemically strengthened glass-ceramics meet an appropriate stress structure, chemically strengthened glass-ceramics with higher stress levels can be obtained. This, in turn, facilitates the improvement of mechanical strength properties achieved by the stress structure, ensuring that the chemically strengthened glass-ceramics meet excellent damage resistance.

As an optional embodiment, chemically strengthened glass-ceramics meets the following requirements:

The value of is: 17652.28 MPa·μm, 18648.12 MPa·μm, 18393.52 MPa·μm, 17182.91 MPa·μm, 16421.45 MPa·μm, 15951.66 MPa·μm, 16840.06 MPa·μm, 17087.83 MPa·μm, 20558.47 MPa·μm or 16014.47 MPa·μm; and/or,

The value of is: 1979.4 MPa ² ·mm, 2169.7 MPa ² ·mm, 2072.2 MPa ² ·mm, 1831.0 MPa ² ·mm, 1667.1 MPa ² ·mm, 1604.1 MPa ² ·mm, 1777.7 MPa ² ·mm, 1935.2 MPa ² ·mm, 2224.4 MPa ² ·mm or 2199.7 MPa ² ·mm; and/or,

the value of |CT_AV| is: 112.13 MPa, 116.35 MPa, 112.66 MPa, 106.6 MPa, 101.5 MPa, 100.6 MPa, 105.6 MPa, 113.25 MPa, 108.2 MPa or 137.36 MPa; and/or,

The value of DOL_0 is: 111.62 μm, 112.28 μm, 109.58 μm, 107.24 μm, 108.86 μm, 109.68 μm, 110.16 μm, 106.69 μm, 117.52 μm or 98.86 μm; and/or,

The values of CT_LD are: 62066.20 MPa/mm, 64094.89 MPa/mm, 63278.87 MPa/mm, 60850.02 MPa/mm, 57316.32 MPa/mm, 56440.71 MPa/mm, 59046.32 MPa/mm, 62375.72 MPa/mm, 61537.01 MPa/mm or 71118.98 MPa/mm.

As an optional embodiment, the composition of the center or tensile stress layer of the chemically strengthened glass-ceramics, calculated as a molar percentage of oxides, comprises:

_SiO2 : 64%-70%, _Al2O3 : 3.5%-5.0%, _P2O5 : 0.7%-1.5%, _ZrO2 : 1.5%-3%, _Na2O : 0-3%, _K2O : _0-1 %, _Li2O : 20%-26%, _CaO : ^0-1.5 %, _B2O3 : _0-2 %. Meeting a specific glass composition facilitates obtaining glass-ceramics with a specific crystalline phase structure and chemically strengthened glass-ceramics with a specific stress structure.

As an optional embodiment, the composition of the center or the tensile stress layer of the chemically strengthened glass-ceramics, measured in mole percentage of oxides, includes:

The molar percentage of _SiO2 is 64% to 69.5%, preferably, the molar percentage of _SiO2 is 67.5% to 69.5%; and/or,

The molar percentage of Al ₂ O ₃ is 4% to 4.8%, preferably, the molar percentage of Al ₂ O ₃ is 4% to 4.5%; and/or,

The molar percentage of P ₂ O ₅ is 0.8% to 1.5%, preferably, the molar percentage of P ₂ O ₅ is 0.8% to 1.2%; and/or,

The molar percentage of _ZrO2 is 2.5% to 3%, preferably, the molar percentage of _ZrO2 is 2.6% to 3%; and/or,

The molar percentage of Na ₂ O is 0-2%, preferably, the molar percentage of Na ₂ O is 0-1%; and/or,

The molar percentage of K ₂ O is 0 to 0.5%, preferably, the molar percentage of K ₂ O is 0 to 0.3%; and/or,

The molar percentage of Li ₂ O is 20.5% to 25%, preferably, the molar percentage of Li ₂ O is 20.5% to 23.5%; and/or,

The molar percentage of CaO is 0% to 1%, preferably, the molar percentage of CaO is 0.5% to 1%; and/or,

The molar percentage of B ₂ O ₃ is 0 to 1%, and preferably, the molar percentage of B ₂ O ₃ is 0 to 0.8%.

As an optional embodiment, the composition of the center or the tensile stress layer of the chemically strengthened glass-ceramics, measured in mole percentage of oxides, includes:

The molar percentage of _SiO2 is 68.02%, 65.37%, 64.39%, 68.21%, 68.74%, 68.10% or 68.31%; and/or,

The molar _percentage of _Al2O3 is 4.30%, 4.33%, 4.07%, 4.37%, 4.41%, 4.31% or 4.38%; and/or,

The mole _percentage of _P2O5 is 1.17%, 1.16%, 1.14%, 1.10%, 0.95%, 1.13% or 1.22%; and/or,

The mole percentage of _ZrO2 is 2.88%, 2.93%, 2.98%, 2.77%, 2.89%, 2.90% or 2.92%; and/or,

The molar percentage of Na ₂ O is 0.15%, 1.68%, 0.78%, 0.09% or 0%; and/or,

The molar percentage of K ₂ O is 0.07%, 0.06%, 0% or 0.61%; and/or,

The molar percentage of Li ₂ O is 22.40%, 23.17%, 25.68%, 22.47%, 21.48%, 22.43% or 22.50%; and/or,

The molar percentage of CaO is 1.29%, 0.89%, 0.93%, 0.73% or 0.52%; and/or,

The mole percentage of B ₂ O ₃ is 0.08%, 0.8% or 0%.

As an optional embodiment, in the composition of the center or tensile stress layer of the chemically strengthened glass-ceramics, the molar percentage of ZrO ₂ [ZrO ₂ ], the molar percentage of CaO [CaO], the molar percentage of P ₂ O ₅ [P ₂ O ₅ ], the molar percentage of Na ₂ O [Na ₂ O], the molar percentage of K ₂ O [K ₂ O], the molar percentage of B ₂ O ₃ [B ₂ O ₃ ], the molar percentage of Al ₂ O ₃ [Al ₂ O ₃ ], and the molar percentage of SiO ₂ [SiO ₂ ] satisfy the following relationship:

3.5%≤([ _ZrO2 ]+[CaO]+ _{[ P2O5} ])/EXP([ _Na2O ]+[ _K2O ]+[ _B2O3 ])≤5.5%, preferably, 4.5%≤([ _ZrO2 ]+[CaO]+[ _P2O5 ])/EXP _{( [ Na2O} ]+[ _K2O ]+ _{[B2O3 ]} )≤5.3%; and/or,

5%≤[P ₂ O ₅ ]+[Al ₂ O ₃ ]≤6%, preferably, 5.0%≤[P ₂ O ₅ ]+[Al ₂ O ₃ ]≤5.6%, and/or,

15≤([SiO ₂ ]+2×[B ₂ O ₃ ])/[Al ₂ O ₃ ]≤17, preferably, 15.0≤([SiO ₂ ]+2×[B ₂ O ₃ ])/[Al ₂ O ₃ ]≤16.5.

As an optional embodiment, in the composition of the center or tensile stress layer of the chemically strengthened glass-ceramics, the molar percentage of ZrO ₂ [ZrO ₂ ], the molar percentage of CaO [CaO], the molar percentage of P ₂ O ₅ [P ₂ O ₅ ], the molar percentage of Na ₂ O [Na ₂ O], the molar percentage of K ₂ O [K ₂ O], the molar percentage of B ₂ O ₃ [B ₂ O ₃ ], the molar percentage of Al ₂ O ₃ [Al ₂ O ₃ ], and the molar percentage of SiO ₂ [SiO ₂ ] satisfy the following relationship:

the value of ([ZrO ₂ ]+[CaO]+[P ₂ O ₅ ])/EXP([Na ₂ O]+[K ₂ O]+[B ₂ O ₃ ]) is 4.97%, 5.29%, 4.79%, 4.53%, 4.52% or 4.65%; and/or,

The value of [P ₂ O ₅ ]+[Al ₂ O ₃ ] is 5.49%, 5.21%, 5.47%, 5.36%, 5.44% or 5.60%; and/or

The value of ([SiO ₂ ]+2×[B ₂ O ₃ ])/[Al ₂ O ₃ ] is 15.86, 15.10, 15.82, 15.61, 15.95, 15.80, or 15.60.

As an optional embodiment, the sum of the mass of the petalite crystal phase and the lithium disilicate crystal phase accounts for more than 80wt% of all the crystal phases of the chemically strengthened glass-ceramics.

Preferably, the total mass of the petalite crystal phase and the lithium disilicate crystal phase accounts for 85 wt % to 100 wt % of all crystal phases of the chemically strengthened glass-ceramics.

As an optional embodiment, in the chemically strengthened glass-ceramics, the average grain size does not exceed 100 nm, preferably, the average grain size does not exceed 50 nm, and more preferably, the average grain size is 15 to 30 nm; and/or

The crystallinity of the chemically strengthened glass-ceramics is not less than 70%, preferably, the crystallinity of the chemically strengthened glass-ceramics is 80% to 90%, and more preferably, the crystallinity of the chemically strengthened glass-ceramics is 85% to 90%.

As an optional embodiment, the Young's modulus of the chemically strengthened glass-ceramics is greater than 100 GPa, preferably, the Young's modulus is greater than 105 GPa, and more preferably, the Young's modulus is 110 GPa to 120 GPa.

As an optional embodiment, the b value of the chemically strengthened microcrystalline glass is less than 1.0, preferably, the b value is less than 0.7, and more preferably, the b value is ≤0.6; and/or, the chemically strengthened microcrystalline glass is transparent in the visible light wavelength range, preferably, for light with a wavelength of 550nm, the transmittance of the chemically strengthened microcrystalline glass is ≥85%, preferably, the transmittance is ≥90%, and more preferably, the transmittance is ≥90.29%.

As an optional embodiment, a Mohs hardness pen with a Mohs hardness rating of 6 and a tip angle of 35° in horizontal projection is used. The tip of the Mohs hardness pen is vertically inserted into the chemically strengthened glass-ceramics along the thickness direction. When the penetration depth is 80 μm, the load F _{80 μm} required to be applied is ≥100 N, preferably, the load F _{80 μm} required to be applied is ≥110 N; and/or,

The chemically strengthened glass-ceramics is subjected to a sandpaper drop resistance test, using 80-grit sandpaper. The average sandpaper drop resistance height of the chemically strengthened glass-ceramics is ≥0.88 m, preferably, the average sandpaper drop resistance height of the chemically strengthened glass-ceramics is ≥1.1 m.

As an optional embodiment, a Mohs hardness pen with a Mohs hardness rating of 6 and a tip angle of 35° in horizontal projection is used, and the tip of the Mohs hardness pen is vertically inserted into the chemically strengthened micro-ceramics along the thickness direction. The chemically strengthened micro-ceramics meets the following requirements: Preferably More preferably Where h' is the depth of the Mohs hardness pen penetrating into the chemically strengthened micro-ceramic glass, and the angle θ is the angle of the Mohs hardness pen tip in horizontal projection, which is 35°.

In a second aspect, a glass device is provided, which comprises the chemically strengthened microcrystalline glass as described in any embodiment of the first aspect.

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

In a fourth aspect, an electronic device is provided, the electronic device comprising the chemically strengthened microcrystalline glass as described in any embodiment of the first aspect.

As an optional embodiment, 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 chemically strengthened microcrystalline glass as described in any embodiment of the first aspect.

As an optional embodiment, the housing includes a display screen cover assembled on the front side of the electronic device, and the display screen cover includes the chemically strengthened microcrystalline glass as described in any embodiment of the first aspect.

As an optional embodiment, the housing includes a back cover assembled on the back side of the electronic device, and the back cover includes the chemically strengthened microcrystalline glass as described in any embodiment of the first aspect.

As an optional embodiment, 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 chemically strengthened microcrystalline glass as described in any embodiment of the first aspect.

As an optional embodiment, the electronic device further includes a middle frame located between the display module and the housing, and the middle frame includes the chemically strengthened microcrystalline glass as described in any embodiment of the first aspect.

In some embodiments, the housing may be partially or entirely made of chemically strengthened glass-ceramics. The electronic device herein may comprise one or more of the display cover, back cover, camera protection cover, and midframe, wherein the chemically strengthened glass-ceramics described in any embodiment of the first aspect are used.

One or more of the above technical solutions provided by this application have the following advantages compared with the prior art:

This application improves the problem that existing chemically strengthened glass-ceramics, which have a thinner thickness of 0.38mm to 0.60mm, have a crystalline phase structure and stress structure that meet specific requirements. This improves the problem that the existing chemically strengthened glass-ceramics still need to improve their resistance to sharp object penetration and resistance to damage from falling on rough surfaces after the thickness is reduced. This gives the ultra-thin chemically strengthened glass-ceramics excellent resistance to sharp object penetration and excellent resistance to damage from falling on rough surfaces. At the same time, it can ensure that the chemically strengthened glass-ceramics maintains excellent optical properties, so as to meet the application requirements of cover glass for electronic device screen protection. While meeting the market demand for thinner and lighter electronic devices, the chemically strengthened glass-ceramics of this application can greatly reduce the probability of surface damage and breakage caused by impact or sharp object penetration of electronic device screen cover glass, thereby ensuring the safe and stable operation of electronic devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

FIG1 is an XRD pattern of the glass-ceramics of Example 1 of the present application;

FIG2 is a comparison of XRD patterns of the glass-ceramics of Example 1 of the present application and the chemically strengthened glass-ceramics;

FIG3 is a comparison of XRD patterns of the glass-ceramics provided in Example 1 and Comparative Example 1 of the present application;

FIG4 is a transmittance curve diagram of the glass-ceramics provided in Example 1 of the present application;

FIG5 is a comparison diagram of transmittance curves of the glass-ceramics provided in Example 1 of the present application and the chemically strengthened glass-ceramics;

FIG6 is a curve showing the change in compressive stress of the chemically strengthened glass-ceramics as a function of depth provided in Example 1, Comparative Example 1, and Comparative Example 5 of the present application;

FIG7 is a schematic diagram of the penetration resistance test performed in this application;

FIG8 is a schematic diagram of a partial structure of a Mohs hardness pen used for penetration resistance testing in this application;

FIG9 is a curve showing the relationship between load and penetration depth when the chemically strengthened glass-ceramics provided in Example 1 and Comparative Example 1 of the present application were subjected to penetration resistance testing;

FIG10 is a schematic diagram of the front structure of the electronic device mentioned in an embodiment of the present application;

FIG11 is a schematic diagram of the rear structure of the electronic device mentioned in an embodiment of the present application;

FIG12 is a schematic structural diagram of an electronic device mentioned in an embodiment of the present application.

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

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.

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", "optional" and other similar expressions all refer to and may include, but may not include (or may have, may not have). As referred to herein, "and/or" is inclusive, for example, "A and/or B" refers to only A, or only B, or both A and B.

Explanation of terms and test methods:

In this application, glass-ceramics is a type of solid composite material that contains both a glass phase and a crystalline phase (also known as a microcrystalline phase or crystalline phase) produced by targeted, controlled heat treatment of a base glass. Glass-ceramics are also known as glass ceramics, crystallized glass, or crystallized glass.

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.

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.

In this application, the composition at the center of the chemically strengthened microcrystalline glass refers to the composition at the center of the depth or thickness of the chemically strengthened microcrystalline glass or near the center of the depth or thickness, that is, the composition of the area in the chemically strengthened microcrystalline glass where no ion exchange occurs.

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

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 mass content than other crystalline phases present in the glass-ceramics or chemically strengthened glass-ceramics.

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

In this application, crystallinity refers to the percentage of the total mass of the crystalline phase in the microcrystalline glass or chemically strengthened microcrystalline glass to the mass of the microcrystalline glass or chemically strengthened microcrystalline glass, or is also called the total crystalline phase content in the microcrystalline glass or chemically strengthened microcrystalline glass.

In the present application, when light of a certain wavelength is irradiated onto the main surface of the microcrystalline glass or chemically strengthened 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.

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.

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:

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.

In this application, CS_80 refers to the compressive stress value at a depth of 80 μm measured from the main surface of the chemically strengthened microcrystalline glass, in MPa, obtained by testing with an SLP-2000 stress meter.

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.

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.

In this application, the test method of the aforementioned stress performance is as follows: SLP-2000 stress meter is used for testing, the light source wavelength is 518nm, SOC=25.5 (nm/cm)/MPa, refractive index=1.54, exposure time: 300usec. When testing the stress performance of chemically strengthened microcrystalline glass, it is necessary to first drip conductive liquid on the stress meter, and then wipe the chemically strengthened microcrystalline glass sample to be tested clean, place it on the test path, and test its stress value. Among them, the stress meter is SLP-2000 and the conductive liquid used is a conductive liquid with a refractive index of 1.51. Then, the tensile stress linear density (CT_LD) value of the chemically strengthened microcrystalline glass is calculated by the aforementioned tensile stress linear density calculation formula; the stress data of the chemically strengthened microcrystalline glass measured by SLP-2000 is calculated.

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.

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.

In this application, the thickness is obtained by micrometer testing. It should be understood that in the thickness direction of the glass-ceramic sample, the degree of ion exchange changes gradually from the surface to the center, and the overall Na-K and/or Li-Na exchange amount 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 change of the glass-ceramic before and after chemical strengthening is very small and can be basically ignored. The thickness of the glass-ceramic is basically the same as the thickness of the chemically strengthened glass-ceramic obtained from it.

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).

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.

In this application, the crystal phase, crystallinity and average grain size of the glass-ceramics or chemically strengthened glass-ceramics are confirmed by XRD testing. Specifically:

(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 0.2°/min, an operating voltage of 40 kV, and an operating current of 30 mA.

(2) Determination of crystalline phase: Jade software (JADE Standard 8.6) was used to analyze XRD diffraction data and determine the crystalline phase in the sample.

(3) Determination of crystallinity: The 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 fitted total peak area was recorded as the crystallinity of the sample.

(4) Determination of average grain size: The average grain size (or average crystal 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-height 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, and Jade outputs the fitting report. According to the angle 2θ value and Peak FWHM value corresponding to each diffraction peak in the fitting report, the Peak FWHM value is converted into radians: β = (FWHM/180×3.14). The grain size of each diffraction peak is calculated by the Scherrer formula D = Kλ/(βcosθ) and then averaged to obtain the average grain size in the sample.

In this application, the transmittance and b-value of the glass-ceramics of this application were tested using a haze meter, with reference to the national standard "GB/T 7962.12-2010 Test Methods for Colorless Optical Glass - Part 12: Spectral Transmittance." Specifically, the haze meter was used to test the transmittance and b-value of five glass-ceramics from the same batch at different wavelengths. The average b-value of the five glass-ceramics was taken as the b-value result for the glass-ceramics. The average transmittance of the five glass-ceramics at 550nm was taken as the transmittance result for the glass-ceramics at 550nm. The haze meter used in this test was a Konica Minolta CM-3600A spectrophotometer. Its optical system was transmission, its spectroscopic method was a planar reflective grating, its wavelength range was 360nm-740nm, and its wavelength spacing was 10nm. The illumination source was four pulsed xenon lamps. The instrument was placed in an ambient temperature of 24°C and an air humidity of 40%.

In the present application, a Shimadzu UV-2600 ultraviolet-visible spectrophotometer was also used to test the transmittance curve of the glass-ceramics under light with a wavelength ranging from 200 nm to 1000 nm.

The refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium.

Penetration resistance test: This application uses the tip of a Mohs hardness pen to penetrate chemically strengthened microcrystalline glass along the thickness direction to simulate a sharp protruding object penetrating the chemically strengthened microcrystalline glass. The ability to resist sharp object penetration here is obtained through the penetration test of a single sharp object, which can simulate the application scenario of chemically strengthened microcrystalline glass falling to the ground with a sharp protruding object. When the tip of the Mohs hardness pen penetrates to a depth of 80μm, the load F _80μm that needs to be applied to the Mohs hardness pen is tested. In this application, a pen with a Mohs hardness rating of 6 from Mineralab, USA is used as the test pen. The reason for choosing a pen with a Mohs hardness rating of 6 for testing is mainly because, in daily life, the environment that the cover glass of electronic equipment may be exposed to, such as cement floors, fine sand floors, etc., has a hardness roughly equivalent to a Mohs hardness rating of 6. The load F _80μm that needs to be applied when penetrating into the chemically strengthened microcrystalline glass to a depth of 80μm is used to characterize the sample's penetration resistance. The larger the F _80μm value, the greater the load or force required for the tip of a pen with a Mohs hardness rating of 6 to penetrate the chemically strengthened microcrystalline glass to a depth of 80μm, indicating that the chemically strengthened microcrystalline glass is more difficult to penetrate and has better anti-penetration performance.

The specific steps of the penetration resistance test include: first, placing a stainless steel plate on the bottom ring of a tensile testing machine (LT-850A), then placing the chemically strengthened micro-ceramic sample to be tested on the stainless steel plate. Equipped with a Mineralab Mohs hardness grade 6 (M6) squeeze pen (with an acute angle of 35° at the pen tip, as shown in Figure 8), the test software is launched, the movement speed is set to 1mm/min, and the test is started. The M6 squeeze pen will apply force to the center of the chemically strengthened micro-ceramic sample to be tested at the set movement speed until the chemically strengthened micro-ceramic sample cracks and breaks, as shown in Figure 7. The test software is used to output the raw data of the penetration depth and the load applied to the M6 pen tip. When the penetration depth is 80μm, the load applied to the M6 pen tip, F _80μm , is read as the representative value of the penetration resistance performance of the chemically strengthened micro-ceramic sample. Ten chemically strengthened glass-ceramics samples from the same batch were tested, and the average value of the test results was taken as the F _{80 μm} of the chemically strengthened glass-ceramics sample to be tested.

The fragmentation caused by local penetration refers to the partial destruction of the glass surface when it collides with a sharp object with greater hardness (such as a small stone or cement), forming a crack propagation source at the point of destruction. When the compressive stress level on the glass surface is not enough to offset the energy brought by the impact during the collision, the crack propagation will pass through the glass surface area. When the crack along the thickness direction passes through the depth of the compressive stress layer to reach the tensile stress layer area, the crack will rapidly expand in the tensile stress area, causing the crack to penetrate the entire glass, thereby causing the glass to break.

Density test: This application uses Japan ALFA MIRAGE's electronic density balance SD-200L to test the density of microcrystalline glass.

Refractive index test: This application uses the Abbe refractometer WYA-2WAJ produced by Shanghai Lichen Bangxi Instrument Technology Co., Ltd. in China to test the refractive index of microcrystalline glass.

Thermal expansion softening point test: The sample is formed into a cylinder with a diameter of 5.5 mm and a length of 20 mm. The sample is tested using a LINSEIS L75VD1000 thermal expansion instrument. The test output is a thermal expansion test curve. The temperature corresponding to the peak position of the curve is the thermal expansion softening point of the sample.

Average Sandpaper Drop Height Test: In this application, the average sandpaper drop height of the chemically strengthened glass-ceramics tested is calculated by adding the measured sandpaper drop heights of each sample from the same Example or Comparative Example and dividing the sum by the number of samples tested. This value is recorded as the average sandpaper drop height of the tested chemically strengthened glass-ceramics and is used to characterize the drop damage resistance of the chemically strengthened glass-ceramics. This drop damage resistance is measured using uniform sandpaper testing, simulating the application scenario of a chemically strengthened glass-ceramic being dropped onto a surface with relatively uniform roughness.

Specifically, at least 10 samples were taken from each batch for testing, and the average sandpaper drop height was

Where n is the number of glass samples tested in each batch, and hi is the sandpaper drop resistance height of a single sample tested.

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

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;

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. Make the model machine drop 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 drop, 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 is dropped again. Repeat the above process until the chemically strengthened glass-ceramic sample breaks;

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.

Without being bound by any theory, the stress structure, crystal phase structure, and composition of thin chemically strengthened glass-ceramics are closely related to their damage resistance, particularly their resistance to sharp penetration and drop damage. This application further improves the damage resistance of thin chemically strengthened glass-ceramics while maintaining excellent optical properties, particularly ensuring excellent resistance to sharp penetration and drop damage.

Without being bound by any theory, the present application has found that the larger the area enclosed by the compressive stress curve and the straight line y=0, the straight line x=0, and the straight line x=80μm, the greater the stress intensity value within the range of the compressive stress layer depth of 0μm and the compressive stress layer depth of 80μm, and the better the chemically strengthened microcrystalline glass's resistance to sharp object penetration and rough surface drop. Therefore, in the present application, by making the integral area of the compressive stress curve of the chemically strengthened microcrystalline glass in the range of h∈[0μm,80μm] greater than or equal to 15500MPa·μm, the chemically strengthened microcrystalline glass's resistance to sharp object penetration and resistance to rough surface drop damage can be improved, thereby improving the cover glass and the electronic device including the cover glass's resistance to surface penetration damage and drop damage.

To address the issue of chemically strengthened glass-ceramics' resistance to sharp object penetration and drop damage from rough surfaces after being reduced in thickness, a chemically strengthened glass-ceramic, cover glass, electronic device, and glass device are provided, meeting specific crystalline and stress structures. When the thickness is 0.38mm to 0.60mm, the chemically strengthened glass-ceramic exhibits excellent resistance to sharp object penetration and drop damage from rough surfaces, while maintaining excellent optical properties, meeting the application requirements of cover glass.

As described above, in some embodiments of the present application, a chemically strengthened glass-ceramics is provided, wherein the chemically strengthened glass-ceramics contains a petalite crystalline phase and a lithium disilicate crystalline phase, wherein the petalite crystalline phase and the lithium disilicate crystalline phase have a higher mass percentage than other crystalline phases present in the chemically strengthened glass-ceramics;

The thickness t of chemically strengthened glass-ceramics is 0.38mm to 0.60mm;

Chemically strengthened glass-ceramics have a compressive stress layer on the surface and tensile stress inside. Chemically strengthened glass-ceramics meet the following requirements:

0.18≤DOL_0/t≤0.25,

Preferably, More preferably,

Where DOL_0 is the depth of the compressive stress layer, t is the thickness of the chemically strengthened glass-ceramics, h is the depth from the main surface of the chemically strengthened glass-ceramics, and CS(h) is the compressive stress value at the depth h. It is the integral of the compressive stress from any main surface of the chemically strengthened glass-ceramics to the compressive stress layer with a depth of 80 μm from the main surface.

Lithium disilicate (Li ₂ Si ₂ O ₅ ) crystalline phase is an orthorhombic crystal based on an array of [Si ₂ O ₅ ] tetrahedrons, and the shape of the crystal is flat or plate-like. Petalite LiAlSi ₄ O ₁₀ is a monoclinic crystal having a three-dimensional framework structure including a layered structure with folded Si ₂ O ₅ layers connected by Li and Al tetrahedrons. The crystallinity of glass-ceramics with petalite and lithium disilicate as the main crystalline phases can reach more than 70wt%, and the presence of a large number of microcrystalline phases in the glass-ceramics is conducive to better preventing the expansion of cracks and consuming more impact energy during the fracture and crushing process, thereby helping to improve the strength and fracture toughness of the glass-ceramics. At the same time, the refractive index of 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 crystal phase for preparing highly transparent glass-ceramics. Using petalite and lithium disilicate as the main crystalline phases is also conducive to ensuring that the glass-ceramics maintains excellent optical properties. In addition, both the lithium disilicate crystal phase and the petalite crystal phase contain lithium ions that can participate in ion exchange and can be chemically strengthened in a molten salt bath. The Na ⁺ and/or K ⁺ in the salt bath replace the Li ⁺ in the crystal phase structure, forming a surface stress structure, which is beneficial to further improve the mechanical strength performance of the microcrystalline glass.

In this application, the chemically strengthened microcrystalline glass contains petalite crystal phase and lithium disilicate crystal phase as the main crystal phases, which is conducive to obtaining the desired stress structure while ensuring that it has high intrinsic strength (or also called inherent strength), thereby ensuring that the chemically strengthened microcrystalline glass achieves excellent damage resistance at ultra-thin thickness.

This application improves the problem that the existing chemically strengthened microcrystalline glass needs to be improved in terms of resistance to penetration by sharp objects and resistance to damage from falling on rough surfaces after the thickness is thinned by making the thinner chemically strengthened microcrystalline glass meet specific crystal phase structure and stress structure. It gives the ultra-thin chemically strengthened microcrystalline glass excellent resistance to penetration by sharp objects and excellent resistance to damage from falling on rough surfaces, and at the same time ensures that the chemically strengthened microcrystalline glass maintains excellent optical properties, so as to meet the application requirements of cover glass for screen protection of electronic devices.

In some embodiments, the thickness t of the chemically strengthened glass-ceramics can be 0.38mm, 0.39mm, 0.40mm, 0.41mm, 0.42mm, 0.43mm, 0.44mm, 0.45mm, 0.46mm, 0.47mm, 0.48mm, 0.49mm, 0.50mm, 0.51mm, 0.52mm, 0.53mm, 0.54mm, 0.55mm, 0.56mm, 0.57mm, 0.58mm, 0.59mm or 0.60mm, or it can be a value within the numerical range consisting of any two of the above-mentioned specific values as endpoints, as long as the glass-ceramics or chemically strengthened glass-ceramics with the required performance of the 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 with the required performance of the application can be obtained. At present, electronic devices often pursue lightness and thinness, and believe that the smaller the thickness, the lighter the weight, and the better the optical effect. The present application can make the chemically strengthened glass-ceramic product as thin as possible while ensuring strength, so as to meet the requirements of lightweight and thin electronic devices.

In some embodiments, the value of DOL_0/t in the chemically strengthened glass-ceramics can be 0.18-0.25, 0.19-0.24, 0.20-0.23 or 0.21-0.22. In some embodiments, the value of DOL_0/t in the chemically strengthened glass-ceramics can be 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24 or 0.25, or it can be a value within the numerical range consisting of any two of the above specific values as endpoints, as long as the 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 chemically strengthened glass-ceramics with the required performance of the present application can be obtained. By making the depth of the compressive stress layer and the thickness of the chemically strengthened glass-ceramics meet an appropriate proportional relationship, it is beneficial to ensure that the chemically strengthened glass-ceramics is in a better stress distribution state, and thus it is beneficial to play the role of the stress structure in improving the mechanical strength performance.

In some embodiments, The value of may be 15500 MPa·μm to 21000 MPa·μm, 16000 MPa·μm to 20000 MPa·μm, 16500 MPa·μm to 19500 MPa·μm, 17000 MPa·μm to 19000 MPa·μm or 17500 MPa·μm to 18500 MPa·μm. In some embodiments, The value can be 15500MPa·μm, 15900MPa·μm, 17500MPa·μm, 17652.28MPa·μm, 18648.12MPa·μm, 18393.52MPa·μm, 17182.91MPa·μm, 16421.45MPa·μm, 15951.66MPa·μm, 16840.06MPa·μm, 17087.83MPa·μm, 19000MPa·μm, 19500MPa·μm, 20558.47MPa·μm, 16014.47MPa·μm or 21000MPa·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 microcrystalline glass with the required performance of 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.

In some embodiments of the present application, the chemically strengthened glass-ceramics satisfies:

Preferably, More preferably, Where |CT_AV| is the absolute value of the average tensile stress, expressed in MPa. By ensuring that thinner chemically strengthened glass-ceramics meet a specific stress structure, this stress structure improves mechanical strength, ultimately enabling the chemically strengthened glass-ceramics to achieve superior damage resistance.

In some embodiments, The value of may be 1400 MPa ² ·mm to 2300 MPa ² ·mm, 1500 MPa ² ·mm to 2250 MPa ² ·mm, 1600 MPa ² ·mm to 2200 MPa ² ·mm, 1700 MPa ² ·mm to 2150 MPa ² ·mm, 1800 MPa ² ·mm to 2000 MPa ² ·mm, 1900 MPa ² ·mm to 2050 MPa ² ·mm, or 1950 MPa ² ·mm to 2000 MPa ² ·mm. In some embodiments, The value of may be 1400MPa ² ·mm, 1500MPa ² ·mm, 1600MPa ² ·mm, 1700MPa ² ·mm, 1800MPa ² ·mm, 1900MPa ² ·mm, 2000MPa ² ·mm, 2100MPa ² ·mm, 2200MPa ² ·mm, 2300MPa ² ·mm, 1979.4MPa ² ·mm, 2169.7MPa ² ·mm, 2072.2MPa ² ·mm, 1831.0MPa ² ·mm, 1667.1MPa ² ·mm, 1604.1MPa ² ·mm, 1777.7MPa ² ·mm, 1935.2MPa ² ·mm, 2224.4MPa ² The chemically strengthened glass-ceramics can be obtained by adjusting the pressure drop of the chemically strengthened glass-ceramics to 2199.7 MPa·mm or 2199.7 ^MPa ·mm, or can be 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.

In some embodiments of the present application, the chemically strengthened glass-ceramics satisfies: 30 MPa≤CS_80, wherein CS_80 refers to the compressive stress value at a depth of 80 μm measured from the main surface of the chemically strengthened glass-ceramics. In some embodiments, the CS_80 of the chemically strengthened glass-ceramics can be 30 MPa, 35 MPa, 40 MPa, 45 MPa, 50 MPa, 55 MPa, 60 MPa, 69 MPa, 85 MPa, 87.1 MPa, 94.79 MPa, 91.26 MPa, 79.59 MPa, 73.26 MPa, 69.37 MPa, 77.26 MPa, 79.63 MPa, 97.75 MPa, 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, or 150 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.

In some embodiments of the present application, the chemically strengthened glass-ceramics satisfies the following conditions: 100 MPa ≤ |CT_AV|, preferably 110 MPa ≤ |CT_AV|, where |CT_AV| is the absolute value of the average tensile stress. By ensuring that the |CT_AV| of the chemically strengthened glass-ceramics is above 100 MPa, the chemically strengthened glass-ceramics can be guaranteed to have a desired tensile stress layer distribution structure, ensuring a higher surface stress level. A higher surface compressive stress level can offset more residual energy from drops, squeezes, penetrations, impacts, or collisions, thereby ensuring that the chemically strengthened glass-ceramics have excellent damage resistance, such as excellent resistance to penetration by sharp objects and excellent resistance to damage from drops on rough surfaces.

In some embodiments, |CT_AV| of the chemically strengthened glass-ceramics may be 100 MPa to 160 MPa, 100 MPa to 125 MPa, 105 MPa to 120 MPa, 100 MPa to 150 MPa, or 110 MPa to 115 MPa. In some embodiments, the |CT_AV| of the chemically strengthened glass-ceramics can be 100 MPa, 110 MPa, 112.13 MPa, 116.35 MPa, 112.66 MPa, 106.6 MPa, 101.5 MPa, 100.6 MPa, 105.6 MPa, 113.25 MPa, 108.2 MPa, 137.36 MPa, 125 MPa, 130 MPa, 135 MPa, 140 MPa, 150 MPa, or 160 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 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 chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

In some embodiments of the present application, the chemically strengthened glass-ceramics satisfies the following: 90 μm ≤ DOL_0. For example, DOL_0 may be 90 μm to 135 μm, preferably 90 μm ≤ DOL_0 ≤ 120 μm, and more preferably 105 μm ≤ DOL_0 ≤ 118 μm, where DOL_0 represents the depth of the compressive stress layer. By ensuring that the chemically strengthened glass-ceramics have an appropriate DOL_0, it is possible to prevent sudden cracks from penetrating directly into the compressive stress region and the tensile stress region when blunt or sharp objects impact or penetrate the glass-ceramics, thereby shattering the chemically strengthened glass-ceramics. This helps to offset the energy driving crack propagation in the chemically strengthened glass-ceramics, thereby ensuring that the chemically strengthened glass-ceramics has excellent damage resistance, such as excellent resistance to sharp penetration and excellent resistance to drop damage.

In some embodiments, the DOL_0 of the chemically strengthened glass-ceramics can be 90 μm, 92 μm, 95 μm, 98 μm, 100 μm, 105 μm, 113 μm, 115 μm, 111.62 μm, 112.28 μm, 109.58 μm, 107.24 μm, 108.86 μm, 109.68 μm, 110.16 μm, 106.69 μm, 117.52 μm, 98.86 μm, 118 μm, 120 μm, 125 μm, 130 μm, or 135 μm, 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.

In some embodiments of the present application, the chemically strengthened glass-ceramics satisfies the following conditions: 55,000 MPa/mm ≤ CT_LD. For example, CT_LD may be 55,000 MPa/mm to 80,000 MPa/mm, preferably 56,400 MPa/mm ≤ CT_LD ≤ 72,000 MPa/mm, and more preferably 62,000 MPa/mm ≤ CT_LD ≤ 65,000 MPa/mm, where CT_LD represents the linear density of tensile stress. Controlling the CT_LD of the chemically strengthened glass-ceramics to be no less than 55,000 MPa/mm helps ensure a sufficiently dense tensile stress stored within the chemically strengthened glass-ceramics, thereby ensuring a high surface stress level and excellent damage resistance, such as excellent drop damage resistance, to meet market demand.

In some embodiments, the CT_LD of the chemically strengthened glass-ceramics may be 55,000 MPa/mm to 72,000 MPa/mm, 58,000 MPa/mm to 70,000 MPa/mm, 56,000 MPa/mm to 64,000 MPa/mm, or 57,000 MPa/mm to 63,000 MPa/mm. In some embodiments, the CT_LD of the chemically strengthened glass-ceramics can be 55000 MPa/mm, 56400 MPa/mm, 62000 MPa/mm, 64500 MPa/mm, 62066.20 MPa/mm, 64094.89 MPa/mm, 63278.87 MPa/mm, 60850.02 MPa/mm, 57316.32 MPa/mm, 56440.71 MPa/mm, 59046.32 MPa/mm, 62375.72 MPa/mm, 61537.01 MPa/mm. MPa/mm, 71118.98 MPa/mm, 65000 MPa/mm, 66000 MPa/mm, 67000 MPa/mm, 68000 MPa/mm, 69000 MPa/mm, 70000 MPa/mm, 72000 MPa/mm, 74000 MPa/mm, 76000 MPa/mm, 78000 MPa/mm or 80000 MPa/mm, or a value within a numerical range consisting of any two of the above specific values as endpoints, as long as the chemically strengthened micro-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 micro-ceramics having the desired properties of the present application can be obtained.

It should be understood that the chemically strengthened glass-ceramics of the present application can be made from glass-ceramics through chemical strengthening treatment, and unless excessive ion exchange treatment is performed, the composition and phase assembly of the chemically strengthened glass-ceramics deeper than the depth of the compressive stress layer (DOL), such as the center of the chemically strengthened glass-ceramics or the tensile stress layer, are the same or substantially the same as the composition and phase assembly of the glass-ceramics. Compared to the glass-ceramics before chemical strengthening treatment, the composition at the surface of the glass-ceramics article after chemical strengthening treatment may be different from the composition of the glass-ceramics before it undergoes the ion exchange process. This is because, when ion exchange is performed, in the newly formed glass-ceramics, one type of alkali metal ion (e.g., Li ⁺ or Na ⁺ ) at the surface of the glass-ceramics is replaced by a larger alkali metal ion (e.g., Na ⁺ or K ⁺ ), respectively. However, in an embodiment, the glass composition and phase assembly at or near the depth or thickness center of the glass-ceramics article will still have the composition and phase assembly of the newly formed glass-ceramics. That is, in the present application, the composition (eg, the composition of the tensile stress layer) and phase assembly at the center of the chemically strengthened glass-ceramics obtained by chemical strengthening treatment are the same or substantially the same as those of the glass-ceramics that have not been chemically strengthened.

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 is the same or substantially the same as that of the glass-ceramics.

In some embodiments of the present application, the composition of the substrate glass, the glass-ceramics, or the center or tensile stress layer of the chemically strengthened glass-ceramics, measured by molar percentage of oxides, _includes : _SiO₂ : 64%-70%, _Al₂O₃ : 3.5%-5.0%, _{P₂O₅ :} 0.7%-1.5%, _ZrO₂ : 1.5%-3%, _Na₂O : 0-3%, _K₂O : 0-1%, _Li₂O : 20%-26%, CaO: 0-1.5%, and _B₂O₃ : 0-2%. Meeting these specific glass compositions facilitates obtaining glass-ceramics with specific crystalline phase structures and chemically strengthened glass-ceramics _with specific stress structures. 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 with the desired properties is achieved.

In the present application, _SiO2 is an oxide that forms the glass network skeleton, is used to stabilize the network structure of the substrate glass, and is also an important component of the lithium disilicate crystal phase and the petalite crystal phase. When the glass composition contains a sufficiently high content of _SiO2 , it is conducive to the formation of a sufficient amount of petalite crystals and lithium disilicate crystals. However, when the _SiO2 content is too high, it will not only cause the glass's solubility to deteriorate, increase the viscosity of the molten glass liquid, make the glass liquid difficult to clarify, and increase the difficulty of forming the substrate glass, but also cause the substrate glass to prepare microcrystalline glass. The heat treatment time becomes longer. Therefore, in order to meet the glass formability requirements and achieve the desired crystallization effect of the present application, in the present application, the molar percentage content of _SiO2 is set at 64% to 70%, preferably 64% to 69.5%, and more preferably 67.5% to 69.5%.

In some embodiments, the molar percentage of _SiO2 in the composition of the substrate glass, the composition of the glass-ceramics, or the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer, measured as a mole percentage of oxide, can be 64%, 65%, 66%, 67%, 68%, 69%, 69.5%, 70%, 68.02%, 65.37%, 64.39%, 68.21%, 68.74%, 68.10% or 68.31%, 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 chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

In the present application, Al ₂ O ₃ can be used to construct the glass skeleton and is an indispensable component for the formation of petalite. An appropriate amount of Al ₂ O ₃ can stabilize the glass network structure, which is beneficial to improving the mechanical properties, chemical durability and chemical strengthening effect, and inhibits the phase separation of the glass, reduces the thermal expansion coefficient and increases the strain point. When the Al ₂ O ₃ content is too little, the glass tends to have a higher thermal expansion coefficient, its chemical durability is reduced, and the crystal nucleus becomes larger, and the microcrystalline glass is prone to white turbidity; when the Al ₂ O ₃ content is too much, the glass's solubility deteriorates, production becomes difficult, and crystals such as mullite are easily precipitated, causing the glass to lose clarity. Therefore, in order to meet the desired crystal phase structure and enable the microcrystalline glass or chemically strengthened microcrystalline glass to obtain the desired performance, the molar percentage of Al ₂ O ₃ in the present application is set to 3.5% to 5.0%, preferably 4% to 4.8%, and more preferably 4% to 4.5%.

In some embodiments, the molar percentage of _Al2O3 in the composition of the substrate glass, the composition of the glass-ceramics, or the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer, measured as a molar percentage of _oxide, can be 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.1%, 4.2%, 4.4%, 4.5%, 4.8%, 5.0%, 4.51%, 4.30%, 4.33%, 4.07%, 4.37%, 4.41%, 4.31%, or 4.38%, 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 chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

In the present application, _P2O5 is _a glass-forming oxide, which exists in the network structure as a phosphorus-oxygen tetrahedron [ _{PO4 ]} . _P2O5 appears preferentially during the heat treatment process, first causing the glass to phase-segregate and form an amorphous precursor phase _Li3PO4 , and then using _Li3PO4 as _a non-uniform nucleation point, crystalline phases such as lithium silicate grow on _the amorphous _Li3PO4 . As _{the P2O5} content increases, the non-uniform nucleation points increase, and _the grains with _Li3PO4 as nucleation _points are effectively refined, which is beneficial to improving the overall transmittance of the microcrystalline glass, the uniformity of the glass, and reducing the b value. However, when the _P2O5 content is too much, more _Li3PO4 crystals are easily generated, making the _Li2O content for forming _lithium silicate and _petalite insufficient, which in turn causes the substrate glass to easily precipitate quartz crystals, resulting in a decrease in the transmittance of the microcrystalline glass and a decrease in the overall optical uniformity of the microcrystalline glass. When the _P₂O₅ content is too low, the precipitated crystals are too large, which can easily cause the glass to lose clarity. Therefore, to achieve the desired crystallization effect and properties _of the glass-ceramics or chemically strengthened glass-ceramics, the molar percentage _{of P₂O₅} is set to 0.7% to 1.5%, preferably 0.8% to 1.5%, and more preferably 0.8% to 1.2%.

In some embodiments, the molar percentage of _{P2O5 in the composition of the substrate glass, the composition of the glass-ceramics, or the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer, measured as a molar percentage of oxides ,} can be 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.17%, 1.16%, 1.14%, 1.10%, 0.95%, 1.13% or 1.22%, 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 chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

In the present application, an appropriate amount of _ZrO2 can increase the viscosity, elastic modulus, refractive index, chemical stability of the glass and reduce the thermal expansion coefficient of the glass. _ZrO2 exists in the residual glass phase after heat treatment, which helps to improve the mechanical strength properties of the residual glass phase. However, excessive _ZrO2 increases the difficulty of melting the substrate glass and causes crystallization during the substrate glass melting process. Therefore, in order to meet the glass formability requirements and achieve the desired strength effect of the present application, the molar percentage content of _ZrO2 is 1.5% to 3%, preferably 2.5% to 3%, and more preferably 2.6% to 3%.

In some embodiments, the molar percentage of _ZrO2 in the composition of the substrate glass or the composition of the microcrystalline glass or the center of the chemically strengthened microcrystalline glass or the composition of the tensile stress layer can be 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 2.88%, 2.93%, 2.98%, 2.77%, 2.89% or 2.92%, or can be a value within a 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 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 microcrystalline glass with the desired properties of the present application can be obtained.

In this application, _Na₂O is a network-external oxide that provides free oxygen. An appropriate amount of _Na₂O improves the viscosity of the glass, promotes the melting and clarification of the glass liquid, and promotes the precipitation of lithium disilicate crystals, reducing the tendency of the glass to crystallize and increasing its transmittance. However, excessive _Na₂O can affect the glass network structure and, in turn, the strength of the glass-ceramics. Therefore, to ensure that the glass-ceramics or chemically strengthened glass-ceramics meet the desired structure and achieve the desired properties, the molar percentage of _Na₂O is 0-3%, preferably 0-2%, and more preferably 0-1%.

In some embodiments, in terms of molar percentage of oxides, in the composition of the substrate glass, the composition of the glass-ceramics, or the composition of the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer, Na ₂ The molar percentage of O can be 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 0.15%, 1.68%, 0.78% or 0.09%, 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 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 chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

In this application, _K₂O is an oxide outside the glass network. An appropriate amount of _K₂O can reduce the tendency of glass to crystallize and increase its transparency and gloss. However, excessive _K₂O content can increase the glass's crystallization ability, making it susceptible to devitrification and breakage. Therefore, to ensure that the glass-ceramics or chemically strengthened glass-ceramics meet the desired structure and properties, the molar percentage of _K₂O is 0-1%, preferably 0-0.5%, and more preferably 0-0.3%.

In some embodiments, the molar percentage of _{K2O in the composition of the substrate glass, the composition of the glass-ceramics, or the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer, measured as a molar percentage of oxides} , can be 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 0.07%, 0.06%, or 0.61%, 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 is 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 is obtained.

In the present application, _Li2O is the main component of the petalite crystal phase and the lithium disilicate crystal phase, and is also an essential component for achieving chemical strengthening. An appropriate amount of _Li2O is beneficial for ensuring that the transparency, melt forming effect, crystallization ability, chemical strengthening performance, etc. of the microcrystalline glass meet the requirements. When the _Li2O content is too low, not only will the glass easily precipitate impurity crystal phases such as mullite, causing the glass to lose clarity, but it will also easily reduce the glass's meltability or increase its viscosity, making the molding of the base glass difficult; when the _Li2O content is too high, it will easily affect the network structure of the glass and easily make the glass's crystallization ability too strong, increasing the glass's tendency to lose clarity. Therefore, in order to obtain microcrystalline glass or chemically strengthened microcrystalline glass that meets the desired crystal phase structure, optical properties, and mechanical strength properties, the molar percentage of _Li2O is 20% to 26%, preferably 20.5% to 25%, and more preferably 20.5% to 23.5%.

In some embodiments, the molar percentage of _Li₂O in the composition of the substrate glass, the composition of the glass-ceramics, or the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer, measured as a molar percentage of oxide, can be 20%, 20.5%, 21%, 21.5%, 22%, 22.5%, 23%, 23.5%, 24%, 24.5%, 25%, 25.5%, 26%, 22.40%, 23.17%, 25.68%, 22.47%, 21.48%, or 22.43%, 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 is 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 is obtained.

In the present application, CaO can reduce high-temperature viscosity, which is beneficial for glass molding. It can also strengthen the network structure, thereby enhancing the stress yield of the glass-ceramics during the strengthening process. When the CaO content is too high, too much CaO remains in the glass phase, resulting in a refractive index difference with the main crystalline phase, which will lead to a decrease in the transmittance of the glass-ceramics and an increase in haze. Therefore, in order to obtain glass-ceramics or chemically strengthened glass-ceramics that meet the desired optical properties and mechanical strength properties, the molar percentage of CaO is set to 0-1.5%, preferably 0%-1%, and more preferably 0.5%-1%.

In some embodiments, the molar percentage of CaO in the composition of the substrate glass, the composition of the glass-ceramics, or the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer, measured as a mole percentage of oxide, can be 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.29%, 0.89%, 0.93%, 0.73% or 0.52%, or can be a value within a numerical range consisting of any two of the above specific values as endpoints, as long as the 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 chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

In this application, _B2O3 helps lower the melting temperature of the substrate glass and improve _the transmittance, overall uniformity, and other properties of the glass- _ceramics or chemically strengthened glass-ceramics. However, when too much _B2O3 is added, the stress of the glass-ceramics or chemically strengthened glass-ceramics decreases. Furthermore, _{the increased B2O3 content} in the residual glass phase reduces the viscosity of the residual glass phase, promoting the growth of crystals such as lithium monosilicate, and affecting the optical transmittance of the glass-ceramics or chemically strengthened glass-ceramics. Therefore, to obtain glass-ceramics or chemically strengthened glass-ceramics that meet the desired optical and mechanical strength properties, the molar percentage _{of B2O3} is set to 0-2%, preferably 0-1%, and more preferably 0-0.8%.

In some embodiments, the molar percentage of _{B2O3 in the composition of the substrate glass, the composition of the glass-ceramics, or the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer, measured as a mole percentage of oxides ,} can be 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, or 0.08%, 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 chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

In some embodiments of the present application, in the composition of the substrate glass or the composition of the glass-ceramics or the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer, the molar percentage of ZrO ₂ [ZrO ₂ ], the molar percentage of CaO [CaO], the molar percentage of P ₂ O ₅ [P ₂ O ₅ ], the molar percentage of Na ₂ O [Na ₂ O], the molar percentage of K ₂ O [K ₂ O], and the molar percentage of B ₂ O ₃ [B ₂ O ₃ ] satisfy the following relationship:

3.5%≤([ZrO ₂ ]+[CaO]+[P ₂ O ₅ ])/EXP([Na ₂ O]+[K ₂ O]+[B ₂ O ₃ ])≤5.5%, preferably, 4.5%≤([ZrO ₂ ]+[CaO]+[P ₂ O ₅ ])/EXP([Na ₂ O]+[K ₂ O]+[B ₂ O ₃ ])≤5.3%. It should be noted that in the present application, the content relationship formulas for the various oxides are substituted into the formulas based on the percentage content calculated as the oxide mole, and the molar unit is not used in the calculation of the formulas. By adjusting the content of the various oxides to satisfy a specific content relationship, it is advantageous to obtain microcrystalline glass or chemically strengthened microcrystalline glass that meets the desired mechanical strength properties.

In some embodiments, the value of ([ZrO ₂ ]+[CaO]+[P ₂ O ₅ ])/EXP([Na ₂ O]+[K ₂ O]+[B ₂ O ₃ ]) can be 3.5%, 4.0%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 4.97%, 5.29%, 4.79%, 4.53%, 4.52%, or 4.65%, 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 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 micro-ceramics with the desired properties of the present application can be obtained.

In some embodiments of the present application, the molar percentage of _P2O5 [ _P2O5 ] and the molar percentage of _Al2O3 [ _{Al2O3 ]} in the composition of the substrate glass, the composition of the glass-ceramics, or the composition of the center of the chemically _strengthened glass-ceramics or the _tensile stress _layer satisfy the following relationship:

5%≤ _{[P2O5 ]} + _{[ Al2O3} ]≤6%, preferably, 5.0%≤ _{[ P2O5} ]+ _{[ Al2O3} ]≤5.6%. By adjusting the contents _{of P2O5 and Al2O3} to meet _specific ranges, it is beneficial to obtain microcrystalline glass or chemically strengthened microcrystalline glass meeting the desired crystal structure and stress structure.

In some embodiments, the value of [P ₂ O ₅ ] + [Al ₂ O ₃ ] can be 5%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, 6%, 5.49%, 5.21%, 5.47%, 5.36%, or 5.44%, 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 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 micro-ceramics or chemically strengthened micro-ceramics with the desired properties of the present application can be obtained.

In some embodiments of the present application, the molar percentage of B ₂ O ₃ [B ₂ O ₃ ], the molar percentage of Al 2 O 3 [Al ₂ O ₃ ], and the molar percentage of SiO ₂ [SiO ₂ ] in the composition of the substrate glass or the composition of the glass- _ceramics or the center of the chemically strengthened glass-ceramics or the composition of the tensile stress layer satisfy the _following relationship:

15≤([SiO ₂ ]+2×[B ₂ O ₃ ])/[Al ₂ O ₃ ]≤17, preferably, 15.0≤([SiO ₂ ]+2×[B ₂ O ₃ ])/[Al ₂ O ₃ ]≤16.5. By adjusting the contents of SiO ₂ , B ₂ O ₃ , and Al ₂ O ₃ to meet specific ranges, it is advantageous to obtain glass-ceramics or chemically strengthened glass-ceramics that meet desired inherent strength and stress structure.

In some embodiments, the value of ([SiO ₂ ]+2×[B ₂ O ₃ ])/[Al ₂ O ₃ ] can be 15, 15.1, 15.2, 15.3, 15.4, 15.5, 15.6, 15.7, 15.8, 15.9, 16, 16.5, 17, 15.86, 15.82, 15.61, or 15.95, 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 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 micro-ceramics or chemically strengthened micro-ceramics having the desired properties of the present application can be obtained.

In the present application, “the petalite crystalline phase and the lithium disilicate crystalline phase have a higher mass percentage than other crystalline phases present in the chemically strengthened glass-ceramics” or “petalite and lithium disilicate are the main crystalline phases” or other similar expressions mean that the sum of the mass of the petalite crystalline phase and the lithium disilicate crystalline phase accounts for more than 80 mass percent (mass %) of all crystalline phases of the chemically strengthened glass-ceramics according to the embodiments of the present application. In some embodiments of the present application, in the chemically strengthened glass-ceramics, the sum of the mass of the petalite crystalline phase and the lithium disilicate crystalline phase accounts for 80wt% to 100wt% of all crystalline phases of the chemically strengthened glass-ceramics, and preferably, among all crystalline phases of the chemically strengthened glass-ceramics, the sum of the mass of the petalite crystalline phase and the lithium disilicate crystalline phase accounts for 85wt% to 100wt%. In some embodiments, in all crystalline phases of the chemically strengthened glass-ceramics, the sum of the mass proportions of the petalite crystalline phase and the lithium disilicate crystalline phase can be 80 wt%, 80.5 wt%, 81 wt%, 81.5 wt%, 82 wt%, 82.5 wt%, 83 wt%, 83.5 wt%, 84 wt%, 84.5 wt%, 85 wt%, 85.5 wt%, 86 wt%, 86.5 wt%, 87 wt%, 87.5 wt%, 88 wt%, 88.5 wt%, 89 wt%, 89.5 wt%, 90 wt%, 95 wt% or 100 wt%, 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.

In some embodiments of the present application, the chemically strengthened glass-ceramics have an average grain size of no more than 100 nm, preferably no more than 50 nm, and more preferably, an average grain size of 15 to 30 nm. An appropriate average grain size helps the glass-ceramics achieve both excellent optical properties and high intrinsic strength. However, if the average grain size is too high, the glass-ceramics are prone to devitrification, and the chemical strengthening effect is also affected. In the present application, by ensuring that the chemically strengthened glass-ceramics meet an appropriate average grain size, it is beneficial to ensure that the chemically strengthened glass-ceramics achieves excellent mechanical strength and excellent optical properties.

In some embodiments, the average grain size of the chemically strengthened glass-ceramics can be 100 nm, 50 nm, 40 nm, 35 nm, 30 nm, 25 nm, 20 nm, 15 nm, 19.7 nm, 18.6 nm, 20.8 nm, 20.3 nm, 25.2 nm, 23.2 nm, 22.6 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 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.

In some embodiments of the present application, the crystallinity of the chemically strengthened glass-ceramics is not less than 70%. Preferably, the crystallinity of the chemically strengthened glass-ceramics is 80% to 90%, and more preferably, the crystallinity of the chemically strengthened glass-ceramics is 85% to 90%. It should be understood that in the present application, the crystallinity of the glass-ceramics does not change significantly after chemical strengthening to obtain the chemically strengthened glass-ceramics. That is, the crystallinity of the glass-ceramics is the same or substantially the same as the crystallinity of the chemically strengthened glass-ceramics. The higher the crystallinity of the glass-ceramics, the more conducive it is to obtaining high mechanical strength and high damage resistance. However, excessive crystallinity can easily affect the chemical strengthening effect of the glass-ceramics, resulting in a prolonged chemical strengthening time for preparing chemically strengthened glass-ceramics with high stress levels, and can also easily 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 for the chemically strengthened glass-ceramics obtained to also meet the desired crystallinity, which is more conducive to obtaining chemically strengthened glass-ceramics that meet the desired high mechanical strength, high damage resistance, and excellent optical properties.

In some embodiments, the crystallinity of the chemically strengthened glass-ceramics can be 70%, 72%, 74%, 76%, 78%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 86.2%, 88.6%, 87.5%, 87.2%, 86.5%, or 90%, 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.

In some embodiments of the present application, the Young's modulus of the chemically strengthened glass-ceramics is greater than 100 GPa, preferably, greater than 105 GPa, and more preferably, between 110 GPa and 120 GPa. It should be understood that, in the present application, the Young's modulus of the glass-ceramics does not decrease after chemical strengthening treatment to obtain the chemically strengthened glass-ceramics. That is, when the Young's modulus of the glass-ceramics is greater than 100 GPa, the Young's modulus of the chemically strengthened glass-ceramics obtained should also be greater than 100 GPa. A higher Young's modulus helps ensure that the chemically strengthened glass-ceramics have high mechanical strength and high damage resistance.

In some embodiments, the Young's modulus of the chemically strengthened glass-ceramics can be 101 GPa, 102 GPa, 103 GPa, 104 GPa, 105 GPa, 106 GPa, 107 GPa, 108 GPa, 109 GPa, 110 GPa, 111 GPa, 112 GPa, 113 GPa, 114 GPa, 115 GPa, 116 GPa, 117 GPa, 118 GPa, 112.04 GPa, 113.41 GPa, 112.25 GPa, 113.64 GPa, 115.25 GPa, 116.621 GPa, 115.07 GPa, 119 GPa or 120 GPa, 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 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 chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

In some embodiments of the present application, the b value of the chemically strengthened microcrystalline glass is less than 1.0, preferably, the b value is less than 0.70, and more preferably, the b value is ≤ 0.60. It should be understood that in the present application, after the microcrystalline glass is chemically strengthened to obtain chemically strengthened microcrystalline glass, its optical properties will not change significantly, that is, the b value, transmittance, etc. of the microcrystalline glass are the same or substantially the same as the b value, transmittance, etc. of the chemically strengthened microcrystalline glass. In the present application, the b value refers to the optical b value measured under the D65 light source. This application uses Konica Minolta CM-3600A to test the b value in transmittance mode, and b(D65) is displayed in the result. The smaller the b value, the better the display effect of the microcrystalline glass. When the b value is too large, the microcrystalline glass will appear unexpected color, resulting in its display effect failing to meet the application requirements of the display cover glass.

In some embodiments, the b-value of the chemically strengthened glass-ceramics can be 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.39, 0.49, 0.47, 0.59, 0.48, 0.52, 0.32, 0.37, 0.26 or 0.20, or can be a value within a numerical range consisting of any two of the above specific values as endpoints, as long as the 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.

In some embodiments of the present application, the chemically strengthened glass-ceramics is transparent within the visible light wavelength range. Preferably, for light with a wavelength of 550nm, the transmittance of the chemically strengthened glass-ceramics is ≥85%, preferably ≥90%, and more preferably ≥90.29%. Chemically strengthened glass-ceramics meeting this transmittance ensures good light transmittance and transparency, making them suitable for use in display screens with demanding visual effects. The "visible light wavelength range" here refers to light with a wavelength of 360nm-740nm.

In some embodiments, for light with a wavelength of 550 nm, the transmittance of the chemically strengthened glass-ceramics can be 85%, 90%, 90.10%, 90.20%, 90.30%, 90.40%, 90.50%, 91.00%, 91.05%, 91.14%, 90.69%, 90.81%, 90.29%, 90.77%, 90.42%, 91.08%, 91.14% or 92.00%, 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 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 chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

In some embodiments of the present application, a Mohs hardness pen with a Mohs hardness rating of 6 and a tip angle of 35° in horizontal projection is used. The tip of the Mohs hardness pen is vertically penetrated into the chemically strengthened glass-ceramics along the thickness direction. When the penetration depth is 80 μm, the load F _{80 μm} required to be applied is ≥100 N. Preferably, the load F _{80 μm} required to be applied is ≥110 N. In some embodiments, when the penetration depth is 80 μm, the load F _{80 μm} required to be applied can be 100 N, 105 N, 110 N, 115 N, 120 N, 125 N, 130 N, 140 N, 145 N, 150 N, 117.1 N, 128.6 N, 121.5 N, 110.6 N, 103.3 N, 100.12 N, 106.7 N, 108.3 N, 132.5 N, or 103.2 N, 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 micro-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 micro-ceramics having the desired properties of the present application can be obtained.

In some embodiments of the present application, a Mohs hardness pen with a Mohs hardness rating of 6 and a tip angle of 35° in horizontal projection is used, and the tip of the Mohs hardness pen is vertically inserted into the chemically strengthened micro-ceramics along the thickness direction. The chemically strengthened micro-ceramics meets the following requirements: Preferably More preferably Where h' is the depth of the Mohs hardness pen penetrating into the chemically strengthened micro-ceramic glass, and the angle θ is the angle of the Mohs hardness pen tip in horizontal projection, which is 35°.

In some embodiments, a Mohs hardness pen with a Mohs hardness rating of 6 and a tip angle of 35° in horizontal projection is used. When the tip of the Mohs hardness pen is vertically inserted into the chemically strengthened glass-ceramics along the thickness direction, h' is the depth of the Mohs hardness pen penetrating the chemically strengthened glass-ceramics, θ=35°, The value can be 8.3×10 ⁸ MPa·μm ⁴ , 8.5×10 ⁸ MPa·μm ⁴ , 9.0×10 ⁸ MPa·μm ⁴ , 9.4×10 ⁸ MPa·μm ⁴ , 9.9×10 ⁸ MPa·μm ⁴ , 9.8×10 ⁸ MPa·μm ⁴ , 9.2×10 ⁸ MPa·μm ⁴ , 8.8×10 ⁸ MPa·μm ⁴ , 9.1×10 ⁸ MPa·μm ⁴ , 9.5×10 ⁸ MPa·μm ⁴ , 1.0×10 ⁹ MPa·μm ⁴ , 1.1×10 ⁹ MPa·μm ⁴ or 1.2×10 ⁹ MPa·μm ⁴ , 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.

In some embodiments of the present application, the chemically strengthened microcrystalline glass is subjected to a sandpaper drop resistance test, and the sandpaper used is 80-mesh sandpaper. The average sandpaper drop resistance height of the chemically strengthened microcrystalline glass is ≥0.88m. Preferably, the average sandpaper drop resistance height of the chemically strengthened microcrystalline glass is ≥1.1m. In some embodiments, when the chemically strengthened microcrystalline glass is dropped on 80-grit sandpaper in a test, the average sandpaper drop resistance height can be 0.88m, 1.1m, 1.11m, 1.12m, 1.13m, 1.14m, 1.15m, 1.16m, 1.17m, 1.18m, 1.19m, 1.2m, 1.25m, 1.28m, 1.3m, 1.35m, 1.4m, 1.45m, 1.5m, 1.55m, 1.6m, 1.65m, 1.7m, 1.75m, 1.8m, 1.85m, 1.9m, 1.95m or 2m, 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 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 chemically strengthened glass-ceramics having the desired properties of the present application can be obtained.

After introducing the composition, crystal structure and stress structure of chemically strengthened microcrystalline glass, the preparation method of chemically strengthened microcrystalline glass is introduced in detail below.

In this application, the preparation process of chemically strengthened microcrystalline glass mainly includes: the preparation process of microcrystalline glass and the chemical strengthening treatment process, and the preparation process of microcrystalline glass mainly includes: the preparation process of substrate glass and the heat treatment process of substrate glass (through heat treatment, a crystalline phase is formed in the substrate glass, that is, the process of preparing microcrystalline glass).

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.

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 or furnace, heated to 1550°C to 1650°C, preferably kept warm for 5 hours or more under melting temperature conditions, then poured into a molding mold for cooling and molding, preferably cooled to about 900°C, and then placed in an annealing furnace for annealing treatment, preferably the annealing temperature is 450°C to 500°C, and the annealing time is preferably 12 to 48 hours, and 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. Further, 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.

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

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 process is directly performed, and nucleation and target crystal growth are carried out at the temperature reached by the one-step heating process, which can be understood as directly performing a crystallization process. If a two-step heat treatment is performed, it means that a two-step heating process is performed, first a nucleation treatment, i.e., nucleation treatment, is performed, and then a target crystal growth treatment, i.e., crystallization treatment, is performed.

In some embodiments of the present application, in order to precipitate the desired target crystalline phase in the microcrystalline glass and obtain the desired physical and chemical properties, the substrate glass is subjected to nucleation treatment and crystallization treatment in sequence. Furthermore, when performing the nucleation treatment, the nucleation temperature can be 500-700°C and the nucleation time can be 10-1440 minutes; when performing the crystallization treatment, the crystallization temperature can be 600-750°C and the crystallization time can be 5-1440 minutes. During the heat treatment process of the nucleation treatment and the crystallization treatment, it is preferred to control the heating rate to be 5-15°C/min, and more preferably the heating rate to be 10°C/min.

In the present application, after heat treatment, those skilled in the art may further perform other conventional steps to obtain a glass-ceramic sample that meets the required specifications or requirements, for example, shaping treatment, cutting treatment (e.g., cutting using a multi-wire cutting machine), CNC machining (computer numerical control, i.e., CNC machine tools), thinning treatment, or polishing treatment, etc.

In this application, the chemical strengthening treatment, namely the ion exchange method, is carried out 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, and obtaining chemically strengthened microcrystalline glass with better mechanical properties.

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 of 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°C to 550°C. In some embodiments of the present application, the concentration of potassium salt in the salt bath is preferably 0wt% to 80wt%, and the concentration of sodium salt is 20wt% to 100wt%, and more preferably a certain amount (e.g., 0.01wt%-0.3wt%) of lithium salt is added to the salt bath. In some embodiments of the present application, the time for chemical strengthening treatment is preferably 0.1 to 24h. 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.

The 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), car-mounted central control, electronic whiteboard glass, smart home, smart wear (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 that requires chemically strengthened microcrystalline glass. 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.

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

Exemplarily, the 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 screen cover, back cover or camera protection cover of an electronic device. Exemplarily, the chemically strengthened microcrystalline glass with excellent performance provided by the present application can be used in electronic devices. Referring to Figures 10, 11 and 12, 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 screen cover 11 assembled on the front side and a back cover 12 assembled on the back side. The display screen cover 11 is covered on the display module 4, wherein the display screen cover 11 and/or the back cover 12 can be made of the aforementioned chemically strengthened microcrystalline glass. In the embodiment of the present application, the display screen cover 11 and the back cover 12 can be made entirely of the aforementioned chemically strengthened microcrystalline glass, or only partially of the aforementioned 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 (and the side facing away from the display screen), or may cover both the back side and the side frames 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.

In some embodiments of the present application, as shown in Figure 11, 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, and the camera protection cover 13 adopts the aforementioned chemically strengthened microcrystalline glass. In the embodiment of the present application, the camera protection cover 13 may be partially made of the aforementioned chemically strengthened microcrystalline glass, or it may be made of the aforementioned 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, and it may be located on the front side of the electronic device, or it may be located 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.

In some embodiments of the present application, as shown in FIG12 , the electronic device further includes a middle frame 3 located between the display module 4 and the housing 1 . The middle frame 3 may include the aforementioned chemically strengthened microcrystalline glass.

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 chemically strengthened microcrystalline glass, or any two of them can be using the aforementioned chemically strengthened microcrystalline glass, or all three can be using the aforementioned chemically strengthened microcrystalline glass, or all four can be using the aforementioned chemically strengthened microcrystalline glass.

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.

Example 1

1. Preparation of substrate glass

The raw materials were prepared according to the ratio of the oxides 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 more than 30 minutes to obtain a uniform raw material mixture.

The mixed raw material mixture is transferred to a platinum crucible, and then melted in a 1600℃ lifting furnace for more than 5 hours, and then poured into a forming mold for cooling. After cooling to about 900℃, it is placed in a 470℃ annealing furnace for annealing for 12 hours, and then cooled to room temperature with the furnace to obtain the base material glass brick.

2. Preparation of glass-ceramics

Transparent glass-ceramics were produced by sequentially performing nucleation and crystallization treatments on the base glass brick. The composition of the resulting glass-ceramics, measured in molar percentages of oxides, was identical to that of the base glass, as detailed in Table 1.

In order to obtain the microcrystalline glass product of Example 1 of the present application, when performing the nucleation treatment, the temperature is raised to the nucleation temperature at a heating rate of 10°C/min, the nucleation temperature is 570°C, and the nucleation treatment time is 240 minutes; when performing the crystallization treatment, the temperature is raised from the nucleation temperature to the crystallization temperature at a heating rate of 10°C/min, the crystallization temperature is 715°C, and the crystallization treatment time is 90 minutes. The nucleation treatment time here refers to the time the crystallization furnace is kept warm after being heated to the set nucleation temperature at a set heating rate. The crystallization treatment time here refers to the time the crystallization furnace is kept warm after being heated to the set crystallization temperature at a set heating rate.

The obtained glass-ceramic bricks are subjected to cold working processes such as cutting, CNC machining (the CNC machine 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 were subjected to the aforementioned cold working processes to produce polished glass-ceramic sheet samples with a length and width of 50 mm × 50 mm and a thickness of 0.4 mm to 0.55 mm.

3. Preparation of chemically strengthened glass-ceramics

The obtained microcrystalline glass polishing sheet was subjected to a one-step chemical strengthening treatment in a mixed salt solution at 500° C. for 5.0 h. The composition of the mixed salt solution was: 29.99 wt % NaNO ₃ + 69.98 wt % KNO ₃ + 0.03 wt % LiNO ₃ .

After chemical strengthening treatment, take out the microcrystalline glass sample and place it on the strengthening furnace body to slowly cool to room temperature. Then use clean water to wash off the salt wrapped on the surface of the microcrystalline glass. After drying the microcrystalline glass sample, chemically strengthened microcrystalline glass can be obtained.

The glass-ceramics or chemically strengthened glass-ceramics obtained in Example 1 were tested as follows:

The crystal phase composition, crystallinity, average grain size, optical b value, transmittance (under 550 nm wavelength light), thermal expansion softening point, density, refractive index and Young's modulus of the glass-ceramics samples were tested respectively, and the results are shown in Table 2.

The DOL_0, CS_80, |CT_AV|, F _80μm and average sandpaper drop resistance of the chemically strengthened glass-ceramics samples were tested respectively. The CT_LD value was calculated according to the above-mentioned CT_LD calculation formula. At the same time, the stress data of the chemically strengthened glass-ceramics measured by SLP-2000 was used to calculate the The value of , combined with the penetration test results, is calculated The results are shown in Table 3.

Among them, the XRD pattern of the glass-ceramics of Example 1 is shown in Figure 1, and the comparison of the XRD patterns of the glass-ceramics of Example 1 and the chemically strengthened glass-ceramics is shown in Figure 2. As can be seen from Figures 1 and 2, in the present application, the main crystalline phases in the glass-ceramics and the chemically strengthened glass-ceramics are lithium disilicate crystalline phases and petalite crystalline phases, and the crystalline phase structure of the glass-ceramics does not change significantly before and after the chemical strengthening treatment.

The transmittance curve of the glass-ceramics of Example 1 is shown in Figure 4, and a comparison of the transmittance curves of the glass-ceramics provided in Example 1 and the chemically strengthened glass-ceramics is shown in Figure 5. As can be seen from Figures 4 and 5, in this application, both the glass-ceramics and the chemically strengthened glass-ceramics are transparent in the visible light range and have high transmittance. The transmittance of the glass-ceramics does not change significantly before and after the chemical strengthening treatment.

Example 2-Example 10

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.

Comparative Example 1-Comparative Example 8

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.

Among them, the XRD pattern comparison diagram of the micro-ceramics provided by Example 1 and Comparative Example 1 is shown in Figure 3. As can be seen from Figure 3, in the present application, the main crystalline phases in the micro-ceramics provided by Example 1 and Comparative Example 1 are lithium disilicate crystal phases and petalite crystal phases. The curve of the change of compressive stress with depth of the chemically strengthened micro-ceramics provided by Example 1, Comparative Example 1 and Comparative Example 5 is shown in Figure 6. As can be seen from this figure, the area enclosed by the compressive stress curve of the chemically strengthened micro-ceramics provided by Example 1 and the straight line y=0, straight line x=0, and straight line x=80μm is larger than that of Comparative Example 1 and Comparative Example 5. Therefore, the integrated area of the compressive stress curve of the chemically strengthened micro-ceramics provided by Example 1 within the range of h∈[0μm,80μm] is also larger than that of Comparative Example 1 and Comparative Example 5.

When the chemically strengthened microcrystalline glass provided in Example 1 and Comparative Example 1 was subjected to penetration resistance test, the relationship between the load and penetration depth was shown in FIG9 . As can be seen from the figure, the force required for the chemically strengthened microcrystalline glass provided in Example 1 to be penetrated to a depth of 80 μm was significantly greater than that in Comparative Example 1.

Table 1

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.

Table 2

Table 3

It can be seen from the embodiments and comparative examples of Tables 1 to 3 above that, compared with the comparative examples, the embodiment scheme of the present application is adopted, by making the chemically strengthened microcrystalline glass meet the specific crystal phase structure and stress structure, so that the chemically strengthened microcrystalline glass forms a microstructure with lithium disilicate and petalite as the main crystal phases, and the chemically strengthened microcrystalline glass meets the specific stress structure, which not only gives the chemically strengthened microcrystalline glass excellent optical properties (such as high transmittance and low b value) and high intrinsic strength (such as high Young's modulus), but also makes the ultra-thin chemically strengthened microcrystalline glass with a thickness of 0.38mm to 0.60mm have excellent resistance to sharp object penetration and excellent resistance to rough surface drop damage, which can meet the application requirements of cover glass. The chemically strengthened microcrystalline glass of the present application, while meeting the market demand for thin and light electronic equipment, can greatly reduce the probability of surface damage and breakage caused by impact or sharp object penetration of the cover glass of the electronic device screen, thereby ensuring the safe and stable operation of the electronic equipment.

However, in the schemes of Comparative Examples 1 to 8, the stress structure of the chemically strengthened microcrystalline glass does not meet the specific requirements of this application. Ultimately, the chemically strengthened microcrystalline glass obtained in the schemes of each comparative example cannot simultaneously meet the requirements of having excellent resistance to penetration by sharp objects and excellent resistance to damage from falling on rough surfaces.

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

This application improves the problem that existing chemically strengthened glass-ceramics, which have a thinner thickness of 0.38mm to 0.60mm, have a crystalline phase structure and stress structure that meet specific requirements. This improves the problem that the existing chemically strengthened glass-ceramics still need to improve their resistance to sharp object penetration and resistance to damage from falling on rough surfaces after the thickness is reduced. This gives the ultra-thin chemically strengthened glass-ceramics excellent resistance to sharp object penetration and excellent resistance to damage from falling on rough surfaces. At the same time, it can ensure that the chemically strengthened glass-ceramics maintains excellent optical properties, so as to meet the application requirements of cover glass for electronic device screen protection. While meeting the market demand for thinner and lighter electronic devices, the chemically strengthened glass-ceramics of this application can greatly reduce the probability of surface damage and breakage caused by impact or sharp object penetration of electronic device screen cover glass, thereby ensuring the safe and stable operation of electronic devices.

Claims (23)

A chemically strengthened glass-ceramic, characterized in that the chemically strengthened glass-ceramic contains a petalite crystalline phase and a lithium disilicate crystalline phase, wherein the petalite crystalline phase and the lithium disilicate crystalline phase have a higher mass percentage than other crystalline phases present in the chemically strengthened glass-ceramic; The thickness t of the chemically strengthened glass-ceramics is 0.38 mm to 0.60 mm; The chemically strengthened glass-ceramics has a compressive stress layer on the surface and tensile stress inside; the chemically strengthened glass-ceramics satisfies:
0.18≤DOL_0/t≤0.25, Preferably, More preferably, Where DOL_0 is the depth of the compressive stress layer, t is the thickness of the chemically strengthened glass-ceramics, h is the depth from the main surface of the chemically strengthened glass-ceramics, and CS(h) is the compressive stress value at the depth h. It is the integral of the compressive stress from any main surface of the chemically strengthened glass-ceramics to the compressive stress layer with a depth of 80 μm from the main surface. The chemically strengthened glass-ceramics according to claim 1, wherein the chemically strengthened glass-ceramics satisfies: Preferably, More preferably, Where |CT_AV| is the absolute value of the average tensile stress, in MPa. The chemically strengthened glass-ceramics according to claim 1 or 2, wherein the chemically strengthened glass-ceramics satisfies: 100 MPa≤|CT_AV|, preferably, 110 MPa≤|CT_AV|, wherein |CT_AV| is the absolute value of the average tensile stress; and/or, 90 μm≤DOL_0, preferably, 90 μm≤DOL_0≤120 μm, more preferably, 105 μm≤DOL_0≤118 μm, wherein DOL_0 is the depth of the compressive stress layer; and/or, 55000 MPa/mm≤CT_LD, preferably, 56400 MPa/mm≤CT_LD≤72000 MPa/mm, more preferably, 62000 MPa/mm≤CT_LD≤65000 MPa/mm, wherein CT_LD is the tensile stress linear density. The chemically strengthened glass-ceramics according to any one of claims 1 to 3, wherein the chemically strengthened glass-ceramics satisfies: The value of is: 17652.28 MPa·μm, 18648.12 MPa·μm, 18393.52 MPa·μm, 17182.91 MPa·μm, 16421.45 MPa·μm, 15951.66 MPa·μm, 16840.06 MPa·μm, 17087.83 MPa·μm, 20558.47 MPa·μm or 16014.47 MPa·μm; and/or, The value of is: 1979.4 MPa ² ·mm, 2169.7 MPa ² ·mm, 2072.2 MPa ² ·mm, 1831.0 MPa ² ·mm, 1667.1 MPa ² ·mm, 1604.1 MPa ² ·mm, 1777.7 MPa ² ·mm, 1935.2 MPa ² ·mm, 2224.4 MPa ² ·mm or 2199.7 MPa ² ·mm; and/or, the value of |CT_AV| is: 112.13 MPa, 116.35 MPa, 112.66 MPa, 106.6 MPa, 101.5 MPa, 100.6 MPa, 105.6 MPa, 113.25 MPa, 108.2 MPa or 137.36 MPa; and/or, The value of DOL_0 is: 111.62 μm, 112.28 μm, 109.58 μm, 107.24 μm, 108.86 μm, 109.68 μm, 110.16 μm, 106.69 μm, 117.52 μm or 98.86 μm; and/or, The values of CT_LD are: 62066.20 MPa/mm, 64094.89 MPa/mm, 63278.87 MPa/mm, 60850.02 MPa/mm, 57316.32 MPa/mm, 56440.71 MPa/mm, 59046.32 MPa/mm, 62375.72 MPa/mm, 61537.01 MPa/mm or 71118.98 MPa/mm. The chemically strengthened glass-ceramics according to any one of claims 1 to 4, wherein the composition of the center or the tensile stress layer of the chemically strengthened glass-ceramics, calculated as a molar percentage of oxides, comprises: SiO ₂ : 64% to 70%, Al ₂ O ₃ : 3.5% to 5.0%, P ₂ O ₅ : 0.7% to 1.5%, ZrO ₂ : 1.5% to 3%, Na ₂ O: 0 to 3%, K ₂ O: 0 to 1%, Li ₂ O: 20% to 26%, CaO: 0 to 1.5%, B ₂ O ₃ :0~2%. The chemically strengthened glass-ceramics according to any one of claims 1 to 5, characterized in that, in terms of molar percentage of oxides, the composition at the center or in the tensile stress layer of the chemically strengthened glass-ceramics comprises: The molar percentage of _SiO2 is 64% to 69.5%, preferably, the molar percentage of _SiO2 is 67.5% to 69.5%; and/or, The molar percentage of Al ₂ O ₃ is 4% to 4.8%, preferably, the molar percentage of Al ₂ O ₃ is 4% to 4.5%; and/or, The molar percentage of P ₂ O ₅ is 0.8% to 1.5%, preferably, the molar percentage of P ₂ O ₅ is 0.8% to 1.2%; and/or, The molar percentage of _ZrO2 is 2.5% to 3%, preferably, the molar percentage of _ZrO2 is 2.6% to 3%; and/or, The molar percentage of Na ₂ O is 0-2%, preferably, the molar percentage of Na ₂ O is 0-1%; and/or, The molar percentage of K ₂ O is 0 to 0.5%, preferably, the molar percentage of K ₂ O is 0 to 0.3%; and/or, The molar percentage of Li ₂ O is 20.5% to 25%, preferably, the molar percentage of Li ₂ O is 20.5% to 23.5%; and/or, The molar percentage of CaO is 0% to 1%, preferably, the molar percentage of CaO is 0.5% to 1%; and/or, The molar percentage of B ₂ O ₃ is 0 to 1%, and preferably, the molar percentage of B ₂ O ₃ is 0 to 0.8%. The chemically strengthened glass-ceramics according to any one of claims 1 to 6, characterized in that, in terms of molar percentage of oxides, the composition at the center or in the tensile stress layer of the chemically strengthened glass-ceramics comprises: The molar percentage of _SiO2 is 68.02%, 65.37%, 64.39%, 68.21%, 68.74%, 68.10% or 68.31%; and/or, The molar _percentage of _Al2O3 is 4.30%, 4.33%, 4.07%, 4.37%, 4.41%, 4.31% or 4.38%; and/or, The mole _percentage of _P2O5 is 1.17%, 1.16%, 1.14%, 1.10%, 0.95%, 1.13% or 1.22%; and/or, The mole percentage of _ZrO2 is 2.88%, 2.93%, 2.98%, 2.77%, 2.89%, 2.90% or 2.92%; and/or, The molar percentage of Na ₂ O is 0.15%, 1.68%, 0.78%, 0.09% or 0%; and/or, The molar percentage of K ₂ O is 0.07%, 0.06%, 0% or 0.61%; and/or, The molar percentage of Li ₂ O is 22.40%, 23.17%, 25.68%, 22.47%, 21.48%, 22.43% or 22.50%; and/or, The molar percentage of CaO is 1.29%, 0.89%, 0.93%, 0.73% or 0.52%; and/or, The mole percentage of B ₂ O ₃ is 0.08%, 0.8% or 0%. The chemically strengthened glass-ceramics according to any one of claims 1 to 7, characterized in that, in the composition of the center or the tensile stress layer of the chemically strengthened glass-ceramics, the molar percentage of _ZrO2 [ _ZrO2 ], the molar percentage of _CaO [ _CaO ], the molar percentage of _P2O5 [ _P2O5 ], the molar percentage of _Na2O [ _Na2O ], the molar percentage of _K2O [ _K2O ], the molar percentage of _{B2O3 [ B2O3} ], _the molar _{percentage of Al2O3 [Al2O3 ] and} the molar percentage of _SiO2 [ _SiO2 ] satisfy the following relationship: 3.5%≤([ _ZrO2 ]+[CaO]+ _{[ P2O5} ])/EXP([ _Na2O ]+[ _K2O ]+[ _B2O3 ])≤5.5%, preferably, 4.5%≤([ _ZrO2 ]+[CaO]+ _{[ P2O5} ])/EXP _{([Na2O]+[K2O]+[B2O3 ] ) ≤5.3 %} ; and/or, 5%≤[P ₂ O ₅ ]+[Al ₂ O ₃ ]≤6%, preferably, 5.0%≤[P ₂ O ₅ ]+[Al ₂ O ₃ ]≤5.6%, and/or, 15≤([SiO ₂ ]+2×[B ₂ O ₃ ])/[Al ₂ O ₃ ]≤17, preferably, 15.0≤([SiO ₂ ]+2×[B ₂ O ₃ ])/[Al ₂ O ₃ ]≤16.5. The chemically strengthened glass-ceramics according to any one of claims 1 to 8, characterized in that, in the composition of the center or the tensile stress layer of the chemically strengthened glass-ceramics, the molar percentage of _ZrO2 [ _ZrO2 ], the molar percentage of _CaO [ _CaO ], the molar percentage of _P2O5 [ _P2O5 ], the molar percentage of _Na2O [ _Na2O ], the molar percentage of _K2O [ _K2O ], the molar percentage of _{B2O3 [ B2O3} ], _the molar _{percentage of Al2O3 [Al2O3 ] and} the molar percentage of _SiO2 [ _SiO2 ] satisfy the following relationship: the value of ([ZrO ₂ ]+[CaO]+[P ₂ O ₅ ])/EXP([Na ₂ O]+[K ₂ O]+[B ₂ O ₃ ]) is 4.97%, 5.29%, 4.79%, 4.53%, 4.52% or 4.65%; and/or, The value of [P ₂ O ₅ ]+[Al ₂ O ₃ ] is 5.49%, 5.21%, 5.47%, 5.36%, 5.44% or 5.60%; and/or The value of ([SiO ₂ ]+2×[B ₂ O ₃ ])/[Al ₂ O ₃ ] is 15.86, 15.10, 15.82, 15.61, 15.95, 15.80, or 15.60. The chemically strengthened glass-ceramics according to any one of claims 1 to 9, characterized in that the sum of the mass of the petalite crystalline phase and the lithium disilicate crystalline phase accounts for more than 80 wt% of all crystalline phases of the chemically strengthened glass-ceramics. Preferably, the total mass of the petalite crystal phase and the lithium disilicate crystal phase accounts for 85 wt % to 100 wt % of all crystal phases of the chemically strengthened glass-ceramics. The chemically strengthened glass-ceramics according to any one of claims 1 to 10, characterized in that the chemically strengthened glass-ceramics has an average grain size of no more than 100 nm, preferably an average grain size of no more than 50 nm, and more preferably an average grain size of 15 to 30 nm; and/or The chemically strengthened glass-ceramics has a crystallinity of not less than 70%. Preferably, the chemically strengthened glass-ceramics has a crystallinity of 80% to 90%. More preferably, the chemically strengthened glass-ceramics has a crystallinity of 85% to 90%. The chemically strengthened glass-ceramics according to any one of claims 1 to 11 is characterized in that the Young's modulus of the chemically strengthened glass-ceramics is greater than 100 GPa, preferably, the Young's modulus is greater than 105 GPa, and more preferably, the Young's modulus is 110 GPa to 120 GPa. The chemically strengthened glass-ceramics according to any one of claims 1 to 12, wherein the b value of the chemically strengthened glass-ceramics is less than 1.0, preferably, the b value is less than 0.7, and more preferably, the b value is ≤ 0.6; and/or The chemically strengthened glass-ceramics is transparent in the visible light wavelength range. Preferably, for light with a wavelength of 550 nm, the transmittance of the chemically strengthened glass-ceramics is ≥85%, preferably ≥90%, and more preferably ≥90.29%. The chemically strengthened glass-ceramics according to any one of claims 1 to 13, characterized in that, when a Mohs hardness pen with a Mohs hardness rating of 6 and a tip angle of 35° in horizontal projection is used, the tip of the Mohs hardness pen is vertically inserted into the chemically strengthened glass-ceramics along the thickness direction, and when the penetration depth is 80 μm, the load required to be applied is F _{80 μm} ≥ 100 N, preferably, the load required to be applied is F _{80 μm} ≥ 110 N; and/or The chemically strengthened glass-ceramics is subjected to a sandpaper drop resistance test, using 80-mesh sandpaper. The average sandpaper drop resistance height of the chemically strengthened glass-ceramics is ≥0.88 m, preferably, the average sandpaper drop resistance height of the chemically strengthened glass-ceramics is ≥1.1 m. The chemically strengthened glass-ceramics according to any one of claims 1 to 14, characterized in that a Mohs hardness pen with a Mohs hardness rating of 6 and a tip angle of 35° in horizontal projection is used, and the tip of the Mohs hardness pen is vertically inserted into the chemically strengthened glass-ceramics along the thickness direction, and the chemically strengthened glass-ceramics meets the following requirements: Preferably, More preferably, Where h' is the depth of the Mohs hardness pen penetrating into the chemically strengthened micro-ceramic glass, and the angle θ is the angle of the Mohs hardness pen tip in horizontal projection, which is 35°. A cover glass, characterized in that the cover glass is made of the chemically strengthened microcrystalline glass according to any one of claims 1 to 15. An electronic device, characterized in that the electronic device comprises the chemically strengthened microcrystalline glass according to any one of claims 1 to 15. The electronic device according to claim 17 is 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, and the housing includes the chemically strengthened microcrystalline glass according to any one of claims 1 to 15. The electronic device according to claim 18, characterized in that the housing includes a display cover assembled on the front side of the electronic device, and the display cover includes the chemically strengthened microcrystalline glass according to any one of claims 1-15. The electronic device according to claim 18 or 19, characterized in that the housing includes a back cover assembled on the back side of the electronic device, and the back cover includes the chemically strengthened microcrystalline glass according to any one of claims 1 to 15. The electronic device according to any one of claims 18 to 20 is 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 chemically strengthened microcrystalline glass according to any one of claims 1-15. The electronic device according to any one of claims 18 to 21, characterized in that the electronic device further comprises a middle frame, and the middle frame comprises the chemically strengthened microcrystalline glass according to any one of claims 1 to 15. A glass device, characterized in that the glass device comprises the chemically strengthened micro-ceramic glass according to any one of claims 1 to 15.