Strengthened glass ceramic, cover glass, electronic apparatus and glass device

Abstract

The present application belongs to the technical field of glass ceramics and provides a strengthened glass ceramic, cover glass, an electronic apparatus, and a glass device. By using a zinc aluminum spinel-magnesium aluminum spinel solid solution as a principal crystalline phase of the glass ceramic, the glass ceramic can be endowed with high intrinsic strength. Additionally, by making the stress at different depths of a surface of the strengthened glass ceramic having the zinc aluminum spinel-magnesium aluminum spinel solid solution as the principal crystalline phase, the diffusion depth of K ions, and the depth of a compressive stress layer meet the requirements of formula X, the surface of the strengthened glass ceramic having high intrinsic strength exhibits a specific stress distribution structure, so that the strengthened glass ceramic exhibits excellent scratch resistance. Applying the strengthened glass ceramic to an electronic apparatus such as a mobile phone or a smart watch facilitates prolonging the service life of the electronic device and improving user experience.

Description

Strengthened glass-ceramics, cover glasses, electronic devices, and glass articles

[0001] Cross Reference to Related Applications

[0002] This application claims priority to the Chinese patent application entitled "Strengthened glass-ceramics, cover glasses, electronic devices, and glass articles" filed on June 7, 2024 with the China National Intellectual Property Office, having the application number 202410740145.9, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of glass-ceramics, and in particular, to a strengthened glass-ceramics, cover glasses, electronic devices, and glass articles. BACKGROUND

[0004] With the rapid development of the electronic information industry, electronic devices such as smart wear, smart phones, computer tablets, etc. are becoming more and more popular. In the process of updating and iterating electronic devices, many new materials are used in the design and manufacture of electronic devices. Glass-ceramic materials are gradually applied to electronic devices due to their excellent mechanical properties (such as bending strength, fracture toughness, surface hardness, etc.) and good light transmittance. For example, as display screen cover glasses, camera protection cover glasses, or back cover glasses of electronic devices, etc.

[0005] In daily use, in addition to the destructive damage caused by falling, impact, and extrusion, the cover glass on the surface of the electronic device will also face the problem of being scratched by dust, dirt (such as sand), etc. For example, after a long time of use, the display screen cover glass of the electronic device is easy to be contaminated by dust or dirt (such as sand), the main component of which is silicon dioxide, and its Mohs hardness level is about 6-7. The existing cover glass is mostly lower than the hardness of the silicon dioxide material. When the finger is drawn on the screen cover glass contaminated by dust or dirt, the dust or dirt will be rubbed on the cover glass, which will cause the surface of the cover glass to be scratched, leaving scratches, and producing a particularly rough hand feeling. Moreover, when the scratches are serious, it will directly affect the display effect of the screen, because when the scratches are serious, the optical performance of the screen cover glass will be greatly affected, such as the haze will increase significantly, thereby affecting the display effect of the screen. In some cases, the cover glass is directly scratched by sharp objects during use, leaving scratches.

[0006] It should be noted that this part of the present application only provides background technology related to the present application, and does not necessarily constitute prior art or known technology. SUMMARY

[0007] At present, the method for enhancing the scratch resistance of the cover plate glass mainly includes spin-coating protective film coating on the surface of the glass, preparing an organic thin film and the like, so as to improve the scratch resistance of the glass. In order to not affect the display effect and normal touch use of the electronic display screen, the scratch-resistant coating is usually set to be very thin, and long-time friction, vibration cracking and the like are easy to cause the coating to be worn off, thereby causing the scratch-resistant performance of the cover plate glass to be unable to be improved.

[0008] Therefore, the purpose of the present application is to provide a strengthened glass ceramic material with excellent scratch resistance, which is used as the display screen cover plate glass of an electronic device, and even if the scratch-resistant coating on the surface thereof is worn off, the excellent scratch resistance can still be maintained. The strengthened glass ceramic provided by the present application can significantly reduce the probability of the display screen cover plate glass being scratched by a hard object, reduce the adverse effects caused by the scratches after being scratched, and is beneficial to improve the service life and user experience of the electronic device.

[0009] In order to achieve the above purpose, the present application provides the following technical solutions.

[0010] In a first aspect, a strengthened glass ceramic is provided, wherein the strengthened glass ceramic comprises a main crystal phase of a zinc aluminum spinel-magnesium aluminum spinel solid solution and a secondary crystal phase of zirconium oxide.

[0011] The strengthened glass ceramic has a compressive stress layer on the surface and a tensile stress in the interior; the strengthened glass ceramic satisfies:

[0012] 1.50≤X≤4.70, preferably 1.50≤X≤4.00, more preferably 1.50≤X≤3.60;

[0013] CS_20 is the compressive stress value at a depth of 20 μm from the main surface of the strengthened glass ceramic, and the unit is MPa;

[0014] CS_30 is the compressive stress value at a depth of 30 μm from the main surface of the strengthened glass ceramic, and the unit is MPa;

[0015] CS_50 is the compressive stress value at a depth of 50 μm from the main surface of the strengthened glass ceramic, and the unit is MPa;

[0016] DOL_0 is the depth of the compressive stress layer of the strengthened glass ceramic, and the unit is μm;

[0017] DOL_K is K + diffusion depth, and the unit is μm;

[0018] In the formula X, the data is substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation.

[0019] In the present application, by taking the zinc aluminate-magnesium aluminate spinel solid solution as the main crystal phase of the glass ceramic, the glass ceramic can be endowed with high intrinsic strength (or also known as inherent strength). At the same time, by making the stress, K ion diffusion depth (or also known as K ion exchange (layer) depth) and the depth of the compressive stress layer of the surface of the strengthened glass ceramic with the main crystal phase being the zinc aluminate-magnesium aluminate spinel solid solution meet the requirements of formula X, the surface of the strengthened glass ceramic with high intrinsic strength has a specific stress distribution structure, and thus the strengthened glass ceramic has excellent scratch resistance. The application of the strengthened glass ceramic in electronic devices, such as in mobile phones, smart watches and other electronic devices, is conducive to improving the service life and user experience of electronic devices. In the present application, (Zn, Mg)Al2O4 is used to represent the zinc aluminate-magnesium aluminate spinel solid solution.

[0020] As an optional embodiment, the strengthened glass ceramic is in the form of a plate; the thickness t of the strengthened glass ceramic is 0.30 mm to 2.00 mm, preferably the thickness t is 0.35 mm to 1.50 mm, more preferably the thickness t is 0.40 mm to 1.00 mm; and / or the strengthened glass ceramic is 2D, 2.5D, 3D or of a special shape. At present, electronic devices are pursuing thinness, and when the thickness is too large, on the one hand, the weight will be increased, and on the other hand, the optical effect will be poor, which is not conducive to achieving high transparency.

[0021] As an optional embodiment, the strengthened glass ceramic satisfies:

[0022] 70.00 MPa≤CS_20≤250.00 MPa, preferably 75.00 MPa≤CS_20≤245.00 MPa, more preferably 80.00 MPa≤CS_20≤240.00 MPa; and / or,

[0023] 60.00 MPa≤CS_30≤240.00 MPa, preferably 65.00 MPa≤CS_30≤230.00 MPa, more preferably 70.00 MPa≤CS_30≤221.00 MPa; and / or,

[0024] 50.00 MPa≤CS_50≤210.00 MPa, preferably 55.00 MPa≤CS_50≤200.00 MPa, more preferably 59.00 MPa≤CS_50≤185.00 MPa; and / or,

[0025] 5.00 pm < DOL_K < 25.00 pm, preferably, 7.00 pm < DOL_K < 23.00 pm, more preferably, 9.00 pm < DOL_K < 21.00 pm; and / or

[0026] 0.17t < DOL_0 < 0.25t, preferably, 0.19t < DOL_0 < 0.25t, t being the thickness of the strengthened glass ceramic; and / or,

[0027] 65.00 pm < DOL_0 < 240.00 pm, preferably, 70.00 pm < DOL_0 < 225.00 pm, more preferably, 75.00 pm < DOL_0 < 215.00 pm. By making the strengthened glass ceramic satisfy the suitable stress profile, it is conducive to obtain the strengthened glass ceramic article with higher stress level, and further conducive to exert the improvement effect of the stress profile on the mechanical strength performance, to ensure that the strengthened glass ceramic satisfies excellent damage resistance and excellent scratch resistance.

[0028] As an alternative embodiment, the strengthened glass ceramic satisfies:

[0029] CS_20 is 104.13 MPa, 83.36 MPa, 90.30 MPa, 190.30 MPa, 203.57 MPa, 101.89 MPa, 80.76 MPa, 111.28 MPa, 122.29 MPa, 142.68 MPa, 111.31 MPa, 162.64 MPa, 172.84 MPa, 238.66 MPa or 131.91 MPa; and / or,

[0030] CS_30 is 95.34 MPa, 76.40 MPa, 78.38 MPa, 168.38 MPa, 187.61 MPa, 93.58 MPa, 73.53 MPa, 99.60 MPa, 110.58 MPa, 116.61 MPa, 103.81 MPa, 149.28 MPa, 149.98 MPa, 220.19 MPa or 124.52 MPa; and / or,

[0031] CS_50 is 78.00 MPa, 62.67 MPa, 69.80 MPa, 99.80 MPa, 156.09 MPa, 77.19 MPa, 59.24 MPa, 79.80 MPa, 87.68 MPa, 66.34 MPa, 88.96 MPa, 123.29 MPa, 124.92 MPa, 184.10 MPa or 109.86 MPa; and / or,

[0032] DOL_K is 12.20 pm, 10.40 pm, 9.60 pm, 14.10 pm, 13.30 pm, 12.80 pm, 11.90 pm, 11.50 pm, 12.20 pm, 10.10 pm, 14.20 pm, 12.50 pm, 12.80 pm, 16.30 pm, or 20.30 pm; and / or,

[0033] DOL_0 is 150.06 pm, 151.72 pm, 153.34 pm, 159.04 pm, 148.22 pm, 156.93 pm, 150.10 pm, 153.34 pm, 153.68 pm, 78.50 pm, 181.56 pm, 182.52 pm, 181.75 pm, 188.84 pm, or 214.61 pm; and / or,

[0034] The value of Formula X is 1.90, 1.56, 2.35, 3.24, 2.07, 1.92, 1.91, 2.27, 2.21, 3.51, 1.79, 2.02, 3.43, 2.59, or 2.18.

[0035] As an optional embodiment, the Vickers hardness of the strengthened glass ceramic is greater than or equal to 750 kgf / mm 2 , preferably, the Vickers hardness of the strengthened glass ceramic is greater than or equal to 800 kgf / mm 2 . By making the Vickers hardness of the strengthened glass ceramic in the range of greater than or equal to 750 kgf / mm 2 , the strengthened glass ceramic has high hardness and high intrinsic strength, thereby ensuring that it has excellent mechanical properties.

[0036] As an optional embodiment, the Vickers hardness of the strengthened glass ceramic is 850 kgf / mm 2 , 810 kgf / mm 2 , 821 kgf / mm 2 , 824 kgf / mm 2 , 806 kgf / mm 2 , 812 kgf / mm 2 , 811 kgf / mm 2 , 823 kgf / mm 2 , 804 kgf / mm 2 , 816 kgf / mm 2 , 845 kgf / mm 2 , 814 kgf / mm 2 , 816 kgf / mm 2 , or 840 kgf / mm 2 .

[0037] As an optional embodiment, the strengthened glass ceramic is transparent in the visible light wavelength range, preferably, the transmittance of the strengthened glass ceramic at 550 nm wavelength is ≥ 85%, preferably ≥ 89% when the thickness t of the strengthened glass ceramic is 0.40 mm to 1.00 mm. The strengthened glass ceramic satisfying the transmittance can ensure good optical performance, better transparency effect, and is suitable for use in electronic device display screens with display effect requirements.

[0038] As an optional embodiment, the composition at the center or the tensile stress layer of the strengthened glass ceramic comprises, in terms of molar percentage of oxides:

[0039] SiO2: 40.00% to 50.00%, Al2O3: 20.00% to 30.00%, MgO: 3.00% to 8.00%, ZnO: 8.00% to 12.00%, BaO: 0% to 8.00%, CaO: 0% to 8.00%, ZrO2: 3.00% to 6.00%, Na2O: 2.00% to 10.00%, Li2O: 3.00% to 12.00%, K2O: 0% to 1.00%, Y2O3: 0% to 15.00%, and La2O3: 0% to 15.00%. By adjusting and controlling the content range of each oxide component, it is beneficial to ensure that the strengthened glass ceramic satisfying the desired crystal phase structure is obtained, and it is also beneficial to ensure that the strengthened glass ceramic obtains excellent optical performance and high intrinsic strength.

[0040] As an optional embodiment, the composition at the center or the tensile stress layer of the strengthened glass ceramic comprises, in terms of molar percentage of oxides:

[0041] The molar percentage of SiO2 is 41.00% to 48.00%, preferably, the molar percentage of SiO2 is 42.00% to 47.00%; and / or,

[0042] The molar percentage of Al2O3 is 22.00% to 29.00%, preferably, the molar percentage of Al2O3 is 25.00% to 28.00%; and / or,

[0043] The molar percentage of MgO is 4.00% to 7.00%, preferably, the molar percentage of MgO is 5.00% to 6.00%; and / or,

[0044] The molar percentage of ZnO is 8.50% to 11.50%, preferably, the molar percentage of ZnO is 9.00% to 11.00%; and / or,

[0045] the mole percent of BaO is 0.50% to 5.00%, preferably the mole percent of BaO is 1.00% to 4.00%; and / or,

[0046] the mole percent of CaO is 0% to 3.00%, preferably the mole percent of CaO is 0% to 1.50%; and / or,

[0047] the mole percent of Zr02 is 3.00% to 5.00%, preferably the mole percent of Zr02 is 3.10% to 4.00%; and / or,

[0048] the mole percent of Na20 is 2.50% to 8.00%, preferably the mole percent of Na20 is 3.00% to 6.00%; and / or,

[0049] the mole percent of Li20 is 3.20% to 10.00%, preferably the mole percent of Li20 is 3.50% to 6.00%; and / or,

[0050] the mole percent of Y203 is 0% to 5.00%, preferably the mole percent of Y203 is 0% to 1.00%; and / or,

[0051] the mole percent of La203 is 0% to 5.00%, preferably the mole percent of La203 is 0% to 1.00%.

[0052] As an alternative embodiment, the composition at the center of the strengthened glass ceramic or the composition of the compressive stress layer, in mole percent of oxides, comprises:

[0053] the mole percent of Si02 is 45.31%, 45.76%, 46.29%, 45.13%, 45.85%, 46.76%, or 42.52%; and / or,

[0054] the mole percent of Al203 is 25.80%, 27.03%, 26.36%, 25.70%, 26.10%, 26.62%, or 27.36%; and / or,

[0055] the mole percent of MgO is 5.47%, 5.52%, 5.59%, 5.45%, 5.53%, 5.64%, or 5.80%; and / or,

[0056] the mole percent of ZnO is 9.71%, 9.80%, 10.91%, 9.67%, 9.82%, 9.92%, 10.02%, or 9.96%; and / or,

[0057] the mole percent of BaO is 1.16%, 1.17%, 0%, or 3.47%; and / or,

[0058] CaO is 0% or 0.99%; and / or,

[0059] Zr02is 3.39%, 3.42%, 3.46%, 3.38%, 3.43%, 3.50% or 3.48%; and / or,

[0060] Na20 is 3.39%, 3.43%, 3.47%, 3.38%, 5.39%, 3.50% or 3.55%; and / or,

[0061] Li20 is 5.77%, 3.87%, 3.92%, 5.75%, 3.88%, 4.91%, 3.96% or 3.86%; and / or,

[0062] Y203is 0% or 0.19%; and / or,

[0063] La203is 0% or 0.19%.

[0064] As an optional embodiment, the composition at the center of the strengthened glass ceramic or the tensile stress layer comprises Y203and / or La203, the mole percentage of Y203[Y2O3] and the mole percentage of La203[La2O3] satisfy the following relationship: 0% < [Y2O3] + [La2O3] < 15.00%; preferably, 0% < [Y2O3] + [La2O3] < 5.00%, more preferably, 0% < [Y2O3] + [La2O3] < 1.00%. By adding appropriate amount of Y2O3 and / or La2O3, the strength, hardness, stability and deformation resistance of the strengthened glass ceramic are improved on the basis of adjusting and controlling the content range of each oxide component.

[0065] As an optional embodiment, the composition at the center of the strengthened glass ceramic or the tensile stress layer satisfies: the value of [Y2O3] + [La2O3] is 0% or 0.38%.

[0066] As an optional embodiment, the composition of the strengthened glass ceramic does not contain P2O5, and / or does not contain B2O3, and / or does not contain TiO2, in terms of mole percentage of oxides. In the composition of the strengthened glass ceramic of the present application, the addition of P2O5 easily affects the optical performance of the strengthened glass ceramic, the addition of B2O3 although can improve the melting effect of the substrate glass, but easily affects the toughness and other performances of the strengthened glass ceramic, and the addition of TiO2 easily causes the strengthened glass ceramic to present an undesirable color. Therefore, it is preferred that the strengthened glass ceramic of the present application does not contain P2O5, B2O3, TiO2.

[0067] As an optional embodiment, the crystallinity of the strengthened glass ceramic is 30% to 55%, preferably 40% to 55%; and / or, the average crystal size in the strengthened glass ceramic is no more than 20 nm, preferably 1 nm to 15 nm, more preferably 3 nm to 8 nm. By making the glass ceramic meet the desired crystallinity and appropriate average crystal size, it is beneficial to make the glass ceramic maintain excellent optical performance while meeting excellent mechanical strength performance and high intrinsic strength.

[0068] As an optional embodiment, the strengthened glass ceramic has a haze increase factor of less than 3.00, preferably a haze increase factor of less than 2.50, more preferably a haze increase factor of less than 2.10, after the sandstone scratch test, compared to the haze of the strengthened glass ceramic before the sandstone scratch test.

[0069] The sandstone scratch test refers to placing the strengthened glass ceramic and 1 kg of silica sand in an oscillating abrasion tester for scratch testing, the oscillation frequency of the oscillating abrasion tester is 150 revolutions / min, and the time of the sandstone scratch test is 10 min; the haze increase factor = (the final haze of the strengthened glass ceramic after the sandstone scratch test - the initial haze of the strengthened glass ceramic before the sandstone scratch test) / the initial haze of the strengthened glass ceramic before the sandstone scratch test. The smaller the haze increase factor after the scratch test, the smaller the damage to the strengthened glass ceramic during the scratch test, and the more excellent the scratch resistance of the strengthened glass ceramic.

[0070] In a second aspect, a cover glass is provided, which is made of the strengthened glass ceramic according to any one of the embodiments of the first aspect, or which comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0071] In a third aspect, an electronic device is provided, which comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0072] As an optional embodiment, the electronic device comprises a housing assembled on the outer side of the electronic device, and the housing comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0073] As an optional embodiment, the housing comprises a display screen cover plate assembled on the front side of the electronic device, and the display screen cover plate comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0074] As an optional embodiment, the housing comprises a back cover assembled on the back side of the electronic device, and the back cover comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0075] As an optional embodiment, the electronic device further comprises a camera assembly located inside the housing, the housing comprises a camera protective cover plate covering the camera assembly, and the camera protective cover plate comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0076] As an optional embodiment, the electronic device further comprises a middle frame, and the middle frame comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0077] In some embodiments, the housing can be partially made of the strengthened glass ceramic or entirely made of the strengthened glass ceramic. The electronic device in the present application can be one or more of the display screen cover plate, the back cover, the camera protective cover plate, and the middle frame, which are made of the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0078] In a fourth aspect, a glass device is provided, which comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0079] Compared with the prior art, one or more of the above technical solutions provided in the present application have the following advantages:

[0080] In the present application, by taking the zinc-aluminum spinel-magnesium-aluminum spinel solid solution as the main crystal phase of the glass ceramic, the glass ceramic can be endowed with high intrinsic strength (or also known as inherent strength). At the same time, by making the stress, K ion diffusion depth (or also known as K ion exchange (layer) depth), and the depth of the compressive stress layer of the surface of the strengthened glass ceramic with the main crystal phase being the zinc-aluminum spinel-magnesium-aluminum spinel solid solution meet the requirements of formula X, the surface of the strengthened glass ceramic with high intrinsic strength has a specific stress distribution structure, and thus the strengthened glass ceramic has excellent scratch resistance. The application of the strengthened glass ceramic in electronic devices, such as mobile phones, smart watches, and other electronic devices, is conducive to improving the service life and user experience of the electronic devices. BRIEF DESCRIPTION OF DRAWINGS

[0081] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0082] FIG. 1 is a schematic diagram of a model of sandstone rubbing the surface of the glass ceramic.

[0083] FIG. 2 is a schematic diagram of the front side structure of the electronic device according to the embodiments of the present application.

[0084] FIG. 3 is a schematic diagram of the back side structure of an electronic device according to an embodiment of the present application.

[0085] FIG. 4 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application.

[0086] FIG. 5 is a comparison of XRD patterns of glass-ceramics and strengthened glass-ceramics according to Example 1 of the present application.

[0087] FIG. 6 is a comparison of transmittance curves of glass-ceramics and strengthened glass-ceramics according to Example 1 of the present application, wherein the curve labeled "before strengthening" refers to the transmittance curve of the glass-ceramics, and the curve labeled "after strengthening" refers to the transmittance curve of the strengthened glass-ceramics.

[0088] FIG. 7 is a micrograph of scratch points of strengthened glass-ceramics according to Example 1, Example 2, Comparative Example 1 and Comparative Example 2 after sandstone scratch testing, wherein the black points are scratch points, and wherein a is the test result of Example 1, b is the test result of Example 2, c is the test result of Comparative Example 1, and d is the test result of Comparative Example 2.

[0089] FIG. 8 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application.

[0090] FIG. 9 is a comparison of strengthened glass-ceramics according to Example 4 and Comparative Example 2 after sandstone scratch testing, wherein a is Example 4 and b is Comparative Example 2.

[0091] Reference numerals: 1 - housing; 11 - display screen cover plate; 12 - back cover; 13 - camera protection cover plate; 2 - camera assembly; 3 - middle frame; 4 - display module. DETAILED DESCRIPTION

[0092] The embodiments of the present application will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. The specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not marked with the manufacturer, which are all conventional products that can be purchased on the market.

[0093] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. The terms "optional," "optional," or other similar expressions mean that they may or may not be included (or may or may not be present). The term "and / or" as used herein is inclusive; for example, "A and / or B" means only A, or only B, or both A and B.

[0094] Terminology and testing methods:

[0095] In this application, glass-ceramics are a type of solid composite material that simultaneously contains a glassy phase and a crystalline phase (or microcrystalline phase, crystalline phase, or crystal phase) prepared by targeted and controlled heat treatment of a substrate glass. Glass-ceramics are also known as microcrystalline glass, crystallized glass, or crystalline glass.

[0096] In this application, reinforced glass-ceramics refer to solid composite materials obtained by chemically strengthening glass-ceramics. It should be understood that during chemical strengthening, alkali metal ions with large ionic radii (e.g., potassium or sodium ions) in the molten salt bath (or molten salt bath) will replace alkali metal ions with small ionic radii (e.g., sodium or lithium ions) in the glass-ceramics, thereby generating a volume difference in exchange ions and producing compressive stress (or compressive stress) on the surface of the glass-ceramics.

[0097] In this application, the substrate glass refers to glass that has not undergone nucleation treatment, crystallization treatment, or strengthening treatment, or it is also called base glass.

[0098] In this application, the composition at the center of the reinforced glass ceramic refers to the composition at or near the center of the depth or thickness of the reinforced glass ceramic, that is, the composition of the region in the reinforced glass ceramic that has not undergone ion exchange. It should be understood that the composition at the center of the reinforced glass ceramic is the same as or substantially the same as the composition of the glass ceramic used to prepare the reinforced glass ceramic but which has not yet undergone chemical strengthening treatment.

[0099] In this application, the visible light wavelength range refers to 360nm to 740nm.

[0100] In this application, haze is the percentage of transmitted light intensity that deviates from the incident light by more than 2.5° to the total transmitted light intensity.

[0101] In this application, fogging refers to a state that is semi-transparent, between transparent and opaque.

[0102] In the present application, devitrification refers to the complete loss of the transparent properties of the glass, so that no image can be seen through the glass.

[0103] In the present application, the main crystal phase (or also referred to as the primary crystal phase) refers to a crystal phase having a higher weight content (or also referred to as the weight percentage, the mass percentage) than other crystal phases present in the glass-ceramic.

[0104] In the present application, the crystallinity refers to the percentage of the total mass of the crystal phase or the crystal in the glass-ceramic, or also referred to as the total content of the crystal phase in the glass-ceramic.

[0105] In the present application, the main surface refers to the surface with the largest surface area, such as the upper surface or the lower surface of the horizontally placed glass-ceramic sheet.

[0106] In the present application, when the light of a certain wavelength is irradiated to the main surface of the glass-ceramic, 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.

[0107] In the present application, CS_20, CS_30 and CS_50 respectively refer to the compressive stress values at the depths of 20 μm, 30 μm and 50 μm from the main surface of the self-strengthening glass-ceramic, and the unit is MPa, which are obtained by SLP-2000 stress meter (or also referred to as the scattered light photoelastic stress meter).

[0108] In the present application, DOL_0 refers to the depth of the compressive stress layer, or also referred to as the depth of the compressive stress layer, which specifically refers to the distance from any main surface of the strengthened glass-ceramic to the position close to the surface where the compressive stress is zero, which is obtained by SLP-2000 stress meter.

[0109] In the present application, the test method of the aforementioned stress performance is as follows: when the SLP-2000 stress meter is used to test CS_20, CS_30, CS_50 and DOL_0 of the strengthened glass-ceramic, the related parameters of the stress meter are set as follows: the wavelength of the light source is 518 nm, SOC = 25.5 (nm / cm) / MPa, the refractive index = 1.60, the exposure time is 300 μsec, the stress meter is dripped with the special refractive liquid, then the strengthened glass-ceramic product is wiped clean and placed on the test channel to test its value. The refractive index of the refractive liquid used by SLP-2000 is 1.51.

[0110] In the present application, SOC, i.e. the photoelastic coefficient, photoelasticity mainly refers to the birefringence phenomenon caused by anisotropy after the transparent material is stressed. The value of the residual stress in the material can be obtained by measuring the photoelastic coefficient and the birefringence.

[0111] In the present application, DOL_K refers to the depth of the K + diffusion depth, or also referred to as the K + diffusion layer depth, or also referred to as the K+ exchange (layer) depth, specifically, the depth from any major surface of the strengthened glass-ceramic to the K + depth at which the slope value of the concentration distribution curve (or also referred to as the K concentration distribution curve) is equal to 0.000 for the first time, obtained by Shimadzu electron probe EPMA-1720HT testing. In the present application, the K + concentration distribution curve, the K + diffused into the surface of the glass-ceramic after ion exchange, and with increasing depth, the K + is less and less, and finally, at the depth at which the slope value of the concentration distribution curve is equal to 0.000 for the first time, the K + no longer diffuses inward.

[0112] Electron Probe X-ray Microanalysis (EPMA) testing: Take the tested strengthened glass-ceramic sample, mechanically grind one of the surfaces perpendicular to the glass surface to remove the strengthening layer (the amount of wear removal is 500 pm or more), prepare a cross-section sample, and after grinding the cross-section, perform 30 nm carbon spraying treatment. A linear line in the thickness direction is selected along the ground cross-section by a focused electron beam to obtain the element composition and element concentration distribution in the thickness direction. The electron probe X-ray microanalyzer used in the present application is Shimadzu's EPMA-1720HT, with an acceleration voltage of 15 kV, a probe current of 100 nA, a beam size of MIN, a step interval of 1 pm, and a time of 1 s / point; a spectrometer crystal RAP (Na K a ray), a spectrometer crystal PET (K K a ray); and the testing elements are Na and K.

[0113] In the present application, scratches refer to permanent scratches left on the surface of the glass-ceramic after friction by objects such as sand and stones.

[0114] In the present application, Vickers hardness refers to a standard for indicating the hardness of a material proposed by British Robert L. Smith and George E. Sandland in 1921 at Vickers Ltd.

[0115] In the present application, the testing method of Vickers hardness is as follows: the strengthened glass ceramic is made into a small piece with a size of 50 mm x 50 mm x 0.70 mm or φ46 mm x 0.70 mm, and a glass sample with a clean surface and no visible scratches, pits and cracks is selected as the test sample, and then the Vickers hardness of the sample is measured using a Vickers hardness tester. The Vickers hardness tester used in the present application is a digital small load Vickers hardness tester with a model number of VTD405 from Beijing Kewei Technology Co., Ltd. The test conditions are as follows: load 300 gf, loading time 10 s, and the validity of the indentation meets the standard of GB / T37900-2019 Ultra-thin glass hardness and fracture toughness test method Small load Vickers hardness indentation method. Three different positions on the surface of the same test sample are selected for measurement, and the average value of the three measurement results is taken as the Vickers hardness result of the test sample.

[0116] In the present application, the thickness of the glass ceramic is obtained by a micrometer test. It should be understood that in the thickness direction, the ion exchange degree changes from the surface to the center in a gradient, and the total Na-K and / or Li-Na exchange amount increment (mass) is generally not more than 1.5% of the total mass of the sample, so the expansion effect in the thickness direction is extremely slight, and the thickness can be approximately considered to be basically unchanged. That is, the thickness of the glass ceramic changes very little before and after chemical strengthening, and can be basically ignored. The thickness of the glass ceramic is basically the same as the thickness of the strengthened glass ceramic obtained therefrom.

[0117] In the present application, the density test adopts an electronic density balance SD-200L from Japan ALFAMIRAGE to test the density of the glass ceramic.

[0118] In the present application, the size of the glass ceramic piece is tested by a two-dimensional measuring machine (instrument model Miyu MY-YXCL-4030).

[0119] In the present application, the crystalline phase composition, crystallinity and average crystal size of the glass ceramic are confirmed by XRD test, which is as follows:

[0120] (1) XRD test: The glass ceramic or strengthened glass ceramic of the present application is crushed and ground into a sample with a particle size of less than 75 μm, and the ground sample is tested by an X-ray diffractometer to obtain an XRD diffraction peak curve and XRD diffraction data. The X-ray diffractometer used in the present application is Shimadzu XRD-6100, the target material is copper, 2θ = 10°-80°, the scanning speed is 2° / min, the working voltage is 40 kV, and the working current is 30 mA.

[0121] (2) Determination of crystalline phase: the XRD diffraction data are analyzed by Jade software (JADE Standard 8.6) to determine the crystalline phase in the sample.

[0122] (3) Determination of crystallinity: The test results of XRD (RAW format) were imported into Jade software for fitting, and the crystallinity of the sample was determined by the formula (diffraction peak intensity / total intensity) x 100%.

[0123] (4) Determination of average crystal size: The average crystal size (or also referred to as average grain size) of the sample can be calculated according to the Scherrer formula D = Kλ / (βcosθ) using the test results obtained by XRD. Wherein, λ is the X-ray wavelength, λ = 0.154056 nm, 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 Jade software, and the Jade outputs a fitting report. According to the angle 2θ value and the Peak FWHM value corresponding to each diffraction peak in the fitting report, the Peak FWHM value is converted to radians: β = (FWHM / 180x3.14), and the grain size of each diffraction peak is calculated by the Scherrer formula D = Kλ / (βcosθ) and then averaged to obtain the average crystal size in the sample.

[0124] In the present application, the transmittance of the glass-ceramics is tested by a spectrophotometer. Specifically, the transmittance of light of different wavelengths of 5 pieces of glass-ceramics in the same batch is tested by a spectrophotometer. The average value of the transmittance at 550 nm wavelength of the 5 pieces of glass-ceramics is taken as the transmittance result of the glass-ceramics at 550 nm wavelength. The spectrophotometer used in the present application is a Konica Minolta Spectrophotometer CM-3600A made in Japan, the light receiving system is transmission, the spectrophotometer is a plane diffraction grating, the wavelength range is 360nm-740nm, the wavelength interval is 10nm, the illumination light source is a pulse xenon lamp x 4, the environmental temperature for placing the instrument is 24℃, and the air humidity is 40%.

[0125] In the present application, the sand abrasion test of the strengthened glass ceramic is carried out by using the oscillating abrasion tester of American Taber, and after the sand abrasion test, the haze increase multiple of the strengthened glass ceramic is tested. The specific test process is as follows: take the strengthened glass ceramic sample to be tested, which has a clean surface without visible scratches, pits and cracks and other damages, measure the initial haze, then stick the strengthened glass ceramic sample to be tested on the bottom plate with adhesive tape, and place the bottom plate with the sample on the oscillating abrasion tester, with the strengthened glass ceramic sample facing up, cover the strengthened glass ceramic sample with silica sand, the weight of the silica sand is 1 kg, the particle size is less than 2.5 mm, set the oscillation frequency of the oscillating abrasion tester to 150 rpm, and carry out the sand abrasion test on the strengthened glass ceramic sample, the test time is 10 min. After the test, take out the strengthened glass ceramic sample, clean it and test the final haze after the sand abrasion test. Haze increase multiple = (final haze of the strengthened glass ceramic after the sand abrasion test-initial haze of the strengthened glass ceramic before the sand abrasion test) / initial haze of the strengthened glass ceramic before the sand abrasion test.

[0126] In the process of daily use, in addition to the destructive damage caused by falling, impact, extrusion and other factors, the cover glass on the surface of electronic equipment will also face the problem of scratches caused by dust or dirt. Dust or dirt scratches are also called abrasive wear. When the solid surface contacts dust or dirt, the protruding parts contact each other, and after plastic deformation under a large pressure, they adhere. The adhered parts slide due to friction, and the side of the material with lower hardness is sheared and adhered to the side with higher hardness, forming scratch points or damage points on the surface of the material with lower hardness, thereby causing scratches, as shown in FIG. 1. Scratches can leave scratches, produce a particularly rough feel, and when the scratches are severe, they can also directly affect the display effect of the screen.

[0127] Without being limited by any theory, when the size of dust or dirt (or sand) is less than 500 μm, the scratch distance after scratching is very small, and the smaller scratches can remove the material, thereby causing greater damage to the surface. The removal of the material is related to the interaction strength of the scratch distance between the adjacent modules, which causes the removal of the glass material. When the scratch distance is 1-2 μm, the larger size transverse cracks propagate to the surface, causing brittle peeling of the material. When the scratch distance is 4-10 μm, the material is mainly removed in a ductile manner. Glass brittleness is related to surface microcracks and air bubbles, etc. Increasing the stress of the glass surface to 50 μm and making the glass surface have a specific stress distribution structure can help reduce the above problems. Because the specific stress distribution structure can reduce the crack propagation ability and inhibit the crack propagation, and slow down the attenuation of elastic recovery. The increase in toughness and elastic recovery is achieved by increasing the stiffness and strength of the material, etc. Elastic recovery refers to the degree to which the material recovers to the degree before being stressed after the external force is removed, which is related to the elastic modulus, strength, deformation, fracture and other properties of the material, or crystallization in the glass.

[0128] Theoretically, precipitating high-hardness crystals, such as spinel crystals belonging to the cubic system, in a glass-ceramic material is beneficial to improving the scratch resistance of the glass-ceramic material. Specifically, the chemical general formula of the spinel crystal is AB2O4, wherein A is a divalent metal ion, such as Zn, Fe or Mg, having a tetrahedral coordination, and B is an Al, Cr or Fe metal ion having an octahedral coordination, exemplarily, such as a zinc aluminum spinel-magnesium aluminum spinel solid solution ((Zn, Mg)Al2O4) as shown in FIG. 1. Common spinel crystals include magnesium aluminum spinel (MgAl2O4, or also known as magnesia spinel) crystals and zinc aluminum spinel (ZnAl2O4, or also known as zinc spinel) crystals, because Al-O, Mg-O and Zn-O can all form strong ionic bonds, making the structure firm, hard and chemically stable. The Mohs hardness of the spinel crystal is basically between 7 and 8, close to 8. The strength of silicon dioxide yields to the spinel, so common dust and dirt are generally not easy to scratch the glass-ceramic material with spinel crystals as the main crystal phase. Therefore, theoretically, the controlled precipitation of zinc aluminum spinel crystals and / or magnesium aluminum spinel crystals and / or zinc aluminum spinel-magnesium aluminum spinel solid solution ((Zn, Mg)Al2O4) in the glass can obtain a spinel glass-ceramic with good mechanical properties and good scratch resistance.

[0129] However, the present application further found that the glass-ceramic material with spinel crystals as the main crystal phase, after being strengthened, does not necessarily all achieve excellent scratch resistance. The scratch resistance of the strengthened glass-ceramic material is closely related to the crystal phase composition and the stress distribution structure of the surface of the strengthened glass-ceramic.

[0130] Therefore, in order to make the strengthened glass-ceramic with spinel crystals as the main crystal phase obtain excellent scratch resistance, the present application further studies the crystal phase composition and the stress distribution structure of the surface of the strengthened glass-ceramic. It is found that the stress distribution structure of the surface of the strengthened glass-ceramic to a depth of 50 μm is crucial to improving the scratch resistance of the strengthened glass-ceramic. The greater the external force applied to the surface, the more sharply the elastic recovery decreases until the strengthened glass-ceramic leaves permanent damage. The surface stress structure of the strengthened glass-ceramic counteracts the external force applied to the surface, can slow down the decay of the elastic recovery, and enhance the scratch resistance of the strengthened glass-ceramic. That is, when the stress distribution structure of the surface of the strengthened glass-ceramic meets specific requirements, it can ensure that the strengthened glass-ceramic obtains excellent scratch resistance.

[0131] Therefore, the application provides a strengthened glass ceramic material meeting specific crystal phase composition and surface stress distribution structure, and the strengthened glass ceramic is used as a display screen cover glass of electronic equipment, and even if the scratch-resistant coating on the surface is worn off, the strengthened glass ceramic still has excellent scratch resistance.

[0132] In some embodiments of the application, a strengthened glass ceramic is provided, wherein the strengthened glass ceramic comprises a main crystal phase of zinc aluminate-magnesium aluminate spinel solid solution and a secondary crystal phase of zirconia;

[0133] The strengthened glass ceramic has a compressive stress layer on the surface and a tensile stress in the interior; and the strengthened glass ceramic meets the following conditions:

[0134] 1.50≤X≤4.70, preferably 1.50≤X≤4.00, more preferably 1.50≤X≤3.60;

[0135] CS_20 is the compressive stress value at a depth of 20 μm from the main surface of the strengthened glass ceramic, measured by SLP_2000, and the unit is MPa;

[0136] CS_30 is the compressive stress value at a depth of 30 μm from the main surface of the strengthened glass ceramic, measured by SLP_2000, and the unit is MPa;

[0137] CS_50 is the compressive stress value at a depth of 50 μm from the main surface of the strengthened glass ceramic, measured by SLP_2000, and the unit is MPa;

[0138] DOL_0 is the depth of the compressive stress layer of the strengthened glass ceramic, measured by SLP_2000, and the unit is μm;

[0139] DOL_K is K + diffusion depth, measured by EPMA, and the unit is μm;

[0140] In the formula X, the data is substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit is not involved in the calculation.

[0141] In the present application, by taking the zinc aluminate-magnesium aluminate spinel solid solution as the main crystal phase of the glass ceramic, the glass ceramic can be endowed with high intrinsic strength (or also known as inherent strength). Meanwhile, by making the stress, K ion diffusion depth (or also known as K ion exchange depth) and the depth of the compressive stress layer of the surface of the strengthened glass ceramic with the main crystal phase being the zinc aluminate-magnesium aluminate spinel solid solution satisfy the requirement of formula X, the strengthened glass ceramic with high intrinsic strength has a specific stress distribution structure on the surface, and thus the strengthened glass ceramic has excellent scratch resistance. The strengthened glass ceramic is applied in electronic devices, such as mobile phones, smart watches and other electronic devices, which is conducive to improving the service life and user experience of the electronic devices. In the present application, (Zn, Mg)Al2O4 is used to represent the zinc aluminate-magnesium aluminate spinel solid solution (or also known as zinc spinel-magnesium spinel solid solution, zinc magnesium spinel solid solution).

[0142] In some embodiments, the value of formula X can satisfy: 1.50≤X≤3.55, 1.75≤X≤3.45, 1.90≤X≤3.25 or 2.05≤X≤2.60. In some embodiments, the value of formula X can be 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.85, 1.90, 1.95, 2.00, 2.05, 2.10, 2.15, 2.20, 2.25, 2.30, 2.35, 2.40, 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95, 3.00, 3.05, 3.10, 3.15, 3.20, 3.25, 3.30, 3.35, 3.40, 3.45, 3.50, 3.55, 3.60, 3.65, 3.70, 3.75, 3.80, 3.85, 3.90, 3.95, 4.00, 4.05, 4.10, 4.15, 4.20, 4.25, 4.30, 4.35, 4.40, 4.45, 4.50, 4.55, 4.60, 4.65, 4.70, 1.56, 3.24, 2.07, 1.92, 1.91, 2.27, 2.21, 3.51, 1.79, 2.02, 3.43, 2.59 or 2.18, or can be a value within the numerical range formed by any two of the above specific numerical values as end points, as long as the strengthened glass ceramic with the required 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 range, as long as the strengthened glass ceramic with the required performance of the present application can be obtained.

[0143] In some embodiments of the application, the strengthened glass-ceramics satisfy: 70.00 MPa < CS_20 < 250.00 MPa, preferably, 75.00 MPa < CS_20 < 245.00 MPa, more preferably, 80.00 MPa < CS_20 < 240.00 MPa.

[0144] In some embodiments, the CS_20 of the strengthened glass-ceramics can satisfy: 90.00 MPa < CS_20 < 239.00 MPa, 101.00 MPa < CS_20 < 204.00 MPa, 111.00 MPa < CS_20 < 191.00 MPa, 122.00 MPa < CS_20 < 173.00 MPa, or 131.00 MPa < CS_20 < 163.00 MPa. In some embodiments, the CS_20 of the strengthened glass-ceramics can be: 70.00 MPa, 75.00 MPa, 80.00 MPa, 85.00 MPa, 90.00 MPa, 95.00 MPa, 100.00 MPa, 105.00 MPa, 110.00 MPa, 115.00 MPa, 120.00 MPa, 125.00 MPa, 130.00 MPa, 135.00 MPa, 140.00 MPa, 145.00 MPa, 150.00 MPa, 155.00 MPa, 160.00 MPa, 165.00 MPa, 170.00 MPa, 175.00 MPa, 180.00 MPa, 185.00 MPa, 190.00 MPa, 195.00 MPa, 200.00 MPa, 205.00 MPa, 210.00 MPa, 215.00 MPa, 220.00 MPa, 225.00 MPa, 230.00 MPa, 240.00 MPa, 250.00 MPa, 104.13 MPa, 83.36 MPa, 90.30 MPa, 190.30 MPa, 203.57 MPa, 101.89 MPa, 80.76 MPa, 111.28 MPa, 122.29 MPa, 142.68 MPa, 111.31 MPa, 162.64 MPa, 172.84 MPa, 238.66 MPa, or 131.91 MPa, or a value within a range bounded by any two of the foregoing specific values, as appropriate to yield a strengthened glass-ceramic having the desired properties. It should be appreciated that any of the foregoing ranges can be combined with any other range, as appropriate to yield a strengthened glass-ceramic having the desired properties.

[0145] In some embodiments of the application, the strengthened glass-ceramics satisfy: 60.00 MPa < CS_30 < 240.00 MPa, preferably, 65.00 MPa < CS_30 < 230.00 MPa, more preferably, 70.00 MPa < CS_30 < 221.00 MPa.

[0146] In some embodiments, the CS_30 of the strengthened glass-ceramics can satisfy: 78.00 MPa < CS_30 < 221.00 MPa, 93.00 MPa < CS_30 < 188.00 MPa, 99.00 MPa < CS_30 < 169.00 MPa, 110.00 MPa < CS_30 < 145.00 MPa, or 116.00 MPa < CS_30 < 125.00 MPa. In some embodiments, the CS_30 of the strengthened glass-ceramics can be: 60.00 MPa, 65.00 MPa, 70.00 MPa, 75.00 MPa, 80.00 MPa, 85.00 MPa, 90.00 MPa, 95.00 MPa, 100.00 MPa, 105.00 MPa, 110.00 MPa, 115.00 MPa, 120.00 MPa, 125.00 MPa, 130.00 MPa, 135.00 MPa, 140.00 MPa, 145.00 MPa, 150.00 MPa, 155.00 MPa, 160.00 MPa, 165.00 MPa, 170.00 MPa, 175.00 MPa, 180.00 MPa, 185.00 MPa, 190.00 MPa, 195.00 MPa, 200.00 MPa, 205.00 MPa, 210.00 MPa, 215.00 MPa, 220.00 MPa, 225.00 MPa, 230.00 MPa, 235.00 MPa, 240.00 MPa, 95.34 MPa, 76.40 MPa, 78.38 MPa, 168.38 MPa, 187.61 MPa, 93.58 MPa, 73.53 MPa, 99.60 MPa, 110.58 MPa, 116.61 MPa, 103.81 MPa, 149.28 MPa, 149.98 MPa, 220.19 MPa, or 124.52 MPa, or can be a value within a range defined by any two of the above specific values as endpoints, as long as a strengthened glass-ceramic having the desired properties of the application is obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a strengthened glass-ceramic having the desired properties of the application is obtained.

[0147] In some embodiments of the application, the strengthened glass-ceramic satisfies: 50.00 MPa < CS_50 < 210.00 MPa, preferably, 55.00 MPa < CS_50 < 200.00 MPa, more preferably, 59.00 MPa < CS_50 < 185.00 MPa.

[0148] In some embodiments, the CS_50 of the strengthened glass-ceramic can satisfy: 62.00 MPa < CS_50 < 184.00 MPa, 66.00 MPa < CS_50 < 160.00 MPa, 69.00 MPa < CS_50 < 130.00 MPa, 75.00 MPa < CS_50 < 110.00 MPa, or 85.00 MPa < CS_50 < 100.00 MPa. In some embodiments, the CS_50 of the strengthened glass-ceramic can be: 50.00 MPa, 55.00 MPa, 60.00 MPa, 65.00 MPa, 70.00 MPa, 75.00 MPa, 80.00 MPa, 85.00 MPa, 90.00 MPa, 95.00 MPa, 100.00 MPa, 105.00 MPa, 110.00 MPa, 115.00 MPa, 120.00 MPa, 125.00 MPa, 130.00 MPa, 135.00 MPa, 140.00 MPa, 145.00 MPa, 150.00 MPa, 155.00 MPa, 160.00 MPa, 165.00 MPa, 170.00 MPa, 175.00 MPa, 180.00 MPa, 185.00 MPa, 190.00 MPa, 195.00 MPa, 200.00 MPa, 205.00 MPa, 210.00 MPa, 78.00 MPa, 62.67 MPa, 69.80 MPa, 99.80 MPa, 156.09 MPa, 77.19 MPa, 59.24 MPa, 79.80 MPa, 87.68 MPa, 66.34 MPa, 88.96 MPa, 123.29 MPa, 124.92 MPa, 184.10 MPa, or 109.86 MPa, or can be a value within a range defined by any two of the above specific values as endpoints, as long as a strengthened glass-ceramic having the desired properties of the application is obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a strengthened glass-ceramic having the desired properties of the application is obtained.

[0149] In some embodiments of the application, the strengthened glass-ceramic satisfies: 5.00 μm < DOL_K < 25.00 μm, preferably, 7.00 μm < DOL_K < 23.00 μm, more preferably, 9.00 μm < DOL_K < 21.00 μm.

[0150] In some embodiments, the strengthened glass-ceramics can have a DOL K that satisfies 10.00 pm < DOL K < 17.00 pm, 11.00 pm < DOL K < 15.00 pm, 12.00 pm < DOL K < 14.00 pm, or 12.00 pm < DOL K < 13.00 pm. In some embodiments, the strengthened glass-ceramics can have a DOL K of 5.00 pm, 5.50 pm, 6.00 pm, 6.50 pm, 7.00 pm, 7.50 pm, 8.00 pm, 8.50 pm, 9.00 pm, 9.50 pm, 10.00 pm, 10.50 pm, 11.00 pm, 11.50 pm, 12.00 pm, 12.50 pm, 13.00 pm, 13.50 pm, 14.00 pm, 14.50 pm, 15.00 pm, 15.50 pm, 16.00 pm, 16.50 pm, 17.00 pm, 17.50 pm, 18.00 pm, 18.50 pm, 19.00 pm, 19.50 pm, 20.00 pm, 20.50 pm, 21.00 pm, 21.50 pm, 22.00 pm, 22.50 pm, 23.00 pm, 23.50 pm, 24.00 pm, 24.50 pm, 25.00 pm, 12.20 pm, 10.40 pm, 9.60 pm, 14.10 pm, 13.30 pm, 12.80 pm, 11.90 pm, 11.50 pm, 12.20 pm, 10.10 pm, 14.20 pm, 12.50 pm, 12.80 pm, 16.30 pm, or 20.30 pm, or a value within a range between any two of the above specifically named values, as long as a strengthened glass-ceramic having the desired properties of the present application is obtained. It is to be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a strengthened glass-ceramic having the desired properties of the present application is obtained.

[0151] In some embodiments of the application, the strengthened glass-ceramic satisfies: 0.17t < DOL_0 < 0.25t, preferably, 0.19t < DOL_0 < 0.25t, t being the thickness of the strengthened glass-ceramic. In some embodiments, the strengthened glass-ceramic can have a DOL_0 of 0.17t, 0.18t, 0.19t, 0.20t, 0.21t, 0.22t, 0.23t, 0.24t, or 0.25t, or a value within a range bounded by any two of the foregoing specific values, as long as a strengthened glass-ceramic having the desired properties of the application is obtained. It is understood that in specific embodiments, any of the foregoing ranges can be combined with any other range, as long as a strengthened glass-ceramic having the desired properties of the application is obtained.

[0152] In some embodiments of the application, the strengthened glass-ceramic satisfies: 65.00 μm < DOL_0 < 240.00 μm, preferably, 70.00 μm < DOL_0 < 225.00 μm, more preferably, 75.00 μm < DOL_0 < 215.00 μm.

[0153] In some embodiments, the strengthened glass-ceramic can have a DOL_0 that satisfies: 78.00 pm ≤ DOL_0 ≤ 215.00 pm, 148.00 pm ≤ DOL_0 ≤ 189.00 pm, 150.00 pm ≤ DOL_0 ≤ 190.00 pm, 153.00 pm ≤ DOL_0 ≤ 183.00 pm, or 153.00 pm ≤ DOL_0 ≤ 160.00 pm. In some embodiments, the strengthened glass-ceramic can have a DOL_0 of 65 pm, 70 pm, 75 pm, 80 pm, 85 pm, 90 pm, 95 pm, 100 pm, 105 pm, 110 pm, 115 pm, 120 pm, 125 pm, 130 pm, 135 pm, 140 pm, 145 pm, 150 pm, 155 pm, 160 pm, 165 pm, 170 pm, 175 pm, 180 pm, 185 pm, 190 pm, 195 pm, 200 pm, 205 pm, 210 pm, 215 pm, 220 pm, 225 pm, 230 pm, 235 pm, 240 pm, 150.06 pm, 151.72 pm, 153.34 pm, 159.04 pm, 148.22 pm, 156.93 pm, 150.10 pm, 153.34 pm, 153.68 pm, 78.50 pm, 181.56 pm, 182.52 pm, 181.75 pm, 188.84 pm, or 214.61 pm, or a value within a range between any two of the specifically named values, as long as the strengthened glass-ceramic has the desired properties. It will be appreciated that any of the above ranges can be combined with any other range, as long as the strengthened glass-ceramic has the desired properties.

[0154] In the present application, by making the strengthened glass-ceramic satisfy a suitable stress structure, it is beneficial to obtain a strengthened glass-ceramic article having a higher stress level, and further beneficial to exert the improving effect of the stress structure on the mechanical strength performance, to ensure that the strengthened glass-ceramic satisfies excellent damage resistance and excellent scratch resistance.

[0155] The thickness of the glass-ceramic or strengthened glass-ceramic can be selected by those skilled in the art according to requirements. In some embodiments of the present application, the glass-ceramic or strengthened glass-ceramic is in the form of a plate; the thickness t of the glass-ceramic or strengthened glass-ceramic is 0.30 mm to 2.00 mm, preferably, the thickness t is 0.35 mm to 1.50 mm, more preferably, the thickness t is 0.40 mm to 1.00 mm. Exemplarily, the thickness t of the glass-ceramic or strengthened glass-ceramic can be 0.30 mm to 1.50 mm, 0.30 mm to 1.00 mm, or 0.40 mm to 0.80 mm, 0.80 mm to 1.30 mm, or 0.70 mm to 1.00 mm. At present, electronic devices are pursuing light and thin, and when the thickness is too large, on the one hand, the weight will be increased, and on the other hand, the optical effect will be poor, which is not conducive to achieving high transparency.

[0156] In some embodiments of the present application, the glass-ceramic or strengthened glass-ceramic is 2D, 2.5D, 3D or profiled, that is, the glass-ceramic can be a 2D, 2.5D, 3D or profiled article, and the strengthened glass-ceramic can also be a 2D, 2.5D, 3D or profiled article; and / or, the glass-ceramic or strengthened glass-ceramic is of equal thickness or unequal thickness. Those skilled in the art can select according to requirements. "Unequal thickness" here means that the glass-ceramic or strengthened glass-ceramic contains at least two portions with different thicknesses.

[0157] In the present application, neither the spinel solid solution (Zn, Mg) Al2O4 as the main crystal phase nor the tetragonal ZrO2 crystal phase as the secondary crystal phase contains alkali metal ions, and thus does not participate in ion exchange in the chemical strengthening process. Based on this, the crystal phase structure of the strengthened glass-ceramic obtained by chemical strengthening in the present application is basically the same as that of the glass-ceramic used for chemical strengthening. That is, the crystal phase content, crystal composition, crystal size and other crystal phase structure characteristics of the strengthened glass-ceramic obtained by the chemical strengthening process in the present application are basically the same as those of the glass-ceramic used for chemical strengthening for preparing the strengthened glass-ceramic in the present application. As shown in FIG. 5, in Example 1, the XRD patterns of the glass-ceramic before chemical strengthening and the strengthened glass-ceramic obtained after chemical strengthening are basically the same. In addition, as shown in FIG. 6, in the present application, the transmittance of the glass-ceramic before and after chemical strengthening is also basically the same as that of the strengthened glass-ceramic, that is, in the present application, by using a glass-ceramic with high transmittance, a strengthened glass-ceramic article with the same excellent transmittance can be obtained by chemical strengthening treatment.

[0158] It should be understood that the stress structure generated by the chemical strengthening process can appropriately improve the mechanical properties of the glass article, and thus, in the present application, the mechanical properties such as Young's modulus and Vickers hardness of the glass-ceramic will not decrease after the glass-ceramic is subjected to chemical strengthening treatment to obtain a strengthened glass-ceramic.

[0159] In some embodiments of the present application, the strengthened glass ceramic has a Vickers hardness of greater than or equal to 750 kgf / mm 2 , preferably, the strengthened glass ceramic has a Vickers hardness of greater than or equal to 800 kgf / mm 2 . The Vickers hardness of the strengthened glass ceramic in the above range indicates that the strengthened glass ceramic has high hardness and high intrinsic strength, thereby ensuring excellent mechanical properties.

[0160] In some embodiments, the strengthened glass ceramic can have a Vickers hardness of 750 kgf / mm 2 , 800 kgf / mm 2 , 805 kgf / mm 2 , 810 kgf / mm 2 , 815 kgf / mm 2 , 820 kgf / mm 2 , 825 kgf / mm 2 , 830 kgf / mm 2 , 835 kgf / mm 2 , 840 kgf / mm 2 , 845 kgf / mm 2 , 850 kgf / mm 2 , 855 kgf / mm 2 , 860 kgf / mm 2 , 865 kgf / mm 2 , 870 kgf / mm 2 , 875 kgf / mm 2 , 880 kgf / mm 2 , 885 kgf / mm 2 , 890 kgf / mm 2 , 895 kgf / mm 2 , 900 kgf / mm 2 , 821 kgf / mm 2 , 824 kgf / mm 2 , 806 kgf / mm 2 , 812 kgf / mm 2 , 811 kgf / mm 2 , 823 kgf / mm 2 , 804 kgf / mm 2 , 816 kgf / mm 2 , 814 kgf / mm 2 , 816 kgf / mm 2 , or 814 kgf / mm 2or any value falling within a range defined by any two of the above specific values as endpoints, as long as the strengthened glass-ceramic has the desired properties. It should be understood that in specific embodiments, any of the above ranges can be combined with any of the other ranges, as long as the strengthened glass-ceramic has the desired properties.

[0161] In some embodiments of the application, the strengthened glass-ceramic is transparent in the visible wavelength range, preferably, the transmittance of the strengthened glass-ceramic at a wavelength of 550 nm is > 85%, preferably > 89% when the thickness t of the strengthened glass-ceramic is in the range of 0.40 mm to 1.00 mm.

[0162] The strengthened glass-ceramic satisfying the transmittance can ensure good optical performance and good transparency, and is suitable for use in electronic device display screens that have requirements for display effect. The "visible wavelength range" herein refers to light having a wavelength of 360 nm to 740 nm.

[0163] In some embodiments, the transmittance of the strengthened glass-ceramic at a wavelength of 550 nm can be 85.00%, 89.00%, 89.10%, 89.20%, 89.30%, 89.40%, 89.50%, 89.60%, 89.70%, 89.80%, 89.90%, 90.00%, 90.10%, 90.20%, 90.30%, 90.40%, 90.50%, 91.00%, 92.00%, 89.50%, 89.88%, 89.59%, 89.87%, 89.55%, 89.08%, 89.77%, 89.72%, or 89.17%, or any value falling within a range defined by any two of the above specific values as endpoints, as long as the strengthened glass-ceramic has the desired properties when the thickness t of the strengthened glass-ceramic is in the range of 0.40 mm to 1.00 mm. It should be understood that in specific embodiments, any of the above ranges can be combined with any of the other ranges, as long as the strengthened glass-ceramic has the desired properties.

[0164] It should be understood that the strengthened glass-ceramic of the present application is made from a glass-ceramic that is chemically strengthened, and the composition at the center of the strengthened glass-ceramic or the composition of the compressive stress layer is the same as or substantially the same as the composition of the glass-ceramic. Compared to the glass-ceramic before the chemical strengthening treatment (which involves ion exchange), the composition at the surface of the glass-ceramic article after the chemical strengthening treatment can be different from the composition of the glass-ceramic before the chemical strengthening treatment. This is because, during the chemical strengthening treatment, a type of alkali metal ion (e.g., Li + or Na +) will be replaced by alkali metal ions (e.g., Na + or K + ) with larger ionic radii. However, in embodiments, the glass composition and phase assemblage at or near the center of the depth or thickness of the glass-ceramic article will remain the same as that of the as-formed glass-ceramic. That is, in the present application, the composition (e.g., of the compressive stress layer) and phase assemblage at the center of the strengthened glass-ceramic is the same or substantially the same as that of the glass-ceramic without chemical strengthening treatment.

[0165] In the present application, the glass-ceramic used to prepare the strengthened glass-ceramic can be prepared from a base glass, and the composition of the base glass is the same or substantially the same as that of the glass-ceramic, in terms of mole percent of oxides.

[0166] In some embodiments of the present application, the composition at the center of the strengthened glass-ceramic or the compressive stress layer or the glass-ceramic used to prepare the strengthened glass-ceramic or the base glass comprises: Si02: 40.00% to 50.00%, AI2O3: 20.00% to 30.00%, MgO: 3.00% to 8.00%, ZnO: 8.00% to 12.00%, BaO: 0% to 8.00%, CaO: 0% to 8.00%, Zr02: 3.00% to 6.00%, Na20: 2.00% to 10.00%, Li20: 3.00% to 12.00%, K20: 0% to 1.00%, Y203: 0% to 15.00%, La203: 0% to 15.00%. By adjusting and controlling the content range of each oxide component, it is beneficial to ensure that the strengthened glass-ceramic satisfying the desired crystal phase structure is obtained, while it is also beneficial to ensure that the strengthened glass-ceramic obtains excellent optical performance and high intrinsic strength. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the strengthened glass-ceramic with the desired performance of the present application can be obtained.

[0167] In the present application, Si02 is a network former oxide of the glass network and is an indispensable component of the glass network structure. When the content of Si02 is increased, the stability and mechanical strength of the glass can be increased, but excessive Si02 will increase the viscosity of the base glass, making the glass melting more difficult, thereby reducing the formability of the base glass. In the present application, the mole percent of Si02 in the composition at the center of the strengthened glass-ceramic or the compressive stress layer or the glass-ceramic used to prepare the strengthened glass-ceramic or the base glass is 40.00% or more, preferably 40.00% to 50.00%, more preferably 41.00% to 48.00%, further preferably 42.00% to 47.00%, which is beneficial to balance the stability, formability and mechanical strength performance of the glass.

[0168] In some embodiments of the present application, the content of SiO2 in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 40.00%, 40.50%, 41.00%, 41.50%, 42.00%, 42.50%, 43.00%, 43.50%, 44.00%, 44.50%, 45.00%, 45.50%, 46.00%, 46.50%, 47.00%, 47.50%, 48.00%, 48.50%, 49.00%, 49.50%, 50.00%, 45.31%, 45.76%, 46.29%, 45.13%, 45.85%, 46.76%, or 42.52% in terms of mole percent of oxide, or can be a value within a range defined by any two of the above specific values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with 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 range, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the present application is obtained.

[0169] In the present application, Al2O3 is one of the components of the base glass that forms the main crystal phase (Zn, Mg)Al2O4 crystal phase after crystallization, and directly affects the content of the main crystal phase (Zn, Mg)Al2O4. As the content of Al2O3 increases, the strength of the glass phase in the glass-ceramic is also enhanced, and the mechanical properties of the glass-ceramic are enhanced. At the same time, since [AlO4] is larger in volume than [SiO4], it can provide more space for ion exchange, which is beneficial to the promotion of chemical strengthening. However, excessive Al2O3 will increase the viscosity of the base glass, and reduce the formability of the base glass. In the present application, the mole percent of Al2O3 in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass is greater than 20%, preferably 20% to 30%, more preferably 22.00% to 29.00%, and further preferably 25.00% to 28.00%.

[0170] In some embodiments of the present application, the content of Al2O3 in the composition of the center of the strengthened glass-ceramic or the composition of the compressive stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 20.00%, 20.50%, 21.00%, 21.50%, 22.00%, 22.50%, 23.00%, 23.50%, 24.00%, 24.50%, 25.00%, 25.50%, 26.00%, 26.50%, 27.00%, 27.50%, 28.00%, 28.50%, 29.00%, 29.50%, 30.00%, 25.80%, 27.03%, 26.36%, 25.70%, 26.10%, 26.62%, or 27.36% in terms of mole percent of oxide, or can be a value within a range defined by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with 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 range, as long as a glass-ceramic or strengthened glass-ceramic with desired properties of the present application can be obtained.

[0171] In the present application, ZnO provides the zinc necessary for the base glass to form the main crystalline phase (Zn, Mg) Al2O4 crystalline phase after crystallization. ZnO can reduce the thermal expansion coefficient of the glass, improve the chemical stability, thermal stability, and refractive index of the glass. MgO provides the magnesium necessary for the base glass to form the main crystalline phase (Zn, Mg) Al2O4 crystalline phase after crystallization. MgO can slow down the hardening speed of the glass, improve the forming properties of the glass; MgO can also reduce the crystallization tendency and crystallization speed, increase the high-temperature viscosity of the glass, and improve the chemical stability and mechanical strength of the glass. However, the addition of excessive amounts of MgO and ZnO tends to easily lead to excessively large spinel grains, and it is difficult to obtain a glass-ceramic with high transparency. In the present application, the composition of the center of the strengthened glass-ceramic or the composition of the compressive stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass is as follows: the mole percent of ZnO is 8.00% to 12.00%, preferably 8.50% to 11.50%, and more preferably 9.00% to 11.00%; the mole percent of MgO is 3.00% to 8.00%, preferably 4.00% to 7.00%, and more preferably 5.00% to 6.00%.

[0172] In some embodiments of the present application, the content of ZnO in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 10.50%, 11.00%, 11.50%, 12.00%, 9.71%, 9.80%, 10.91%, 9.67%, 9.82%, 9.92%, 10.02% or 9.96% in terms of mole percent of oxide, or can be a value within a range of values defined by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic 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 range, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained.

[0173] In some embodiments of the present application, the content of MgO in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 5.47%, 5.52%, 5.59%, 5.45%, 5.53%, 5.64% or 5.80% in terms of mole percent of oxide, or can be a value within a range of values defined by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic 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 range, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained.

[0174] In the present application, BaO is an optional component. An appropriate amount of BaO can improve the melting effect of the glass, increase the density of the glass, increase the Young's modulus, and to some extent, inhibit the growth of the crystal grains and improve the optical properties of the glass-ceramic. However, too much BaO has a strong inhibitory effect on the exchange process of Na ions and K ions. In the present application, the mole percent of BaO in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass is 0% to 8.00%, preferably 0% to 5.00%, and more preferably 0% to 4.00%.

[0175] In some embodiments of the application, the content of BaO in the composition of the center of the strengthened glass-ceramic or the composition of the tension stress layer or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 1.16%, 1.17%, 0% or 3.47% in terms of mole percent of oxide, or can be a value within a range of values formed by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the application can be obtained.

[0176] In the present application, CaO is an optional component. Appropriate amount of CaO can improve the chemical stability and mechanical properties of the glass, reduce the melting temperature and high temperature viscosity of the glass, and promote the melting and fining of the glass liquid. However, when the content of CaO is too high, it will increase the crystallization tendency of the glass, reduce the thermal stability of the glass, and increase the annealing temperature. In the present application, the mole percent of CaO in the composition of the center of the strengthened glass-ceramic or the composition of the tension stress layer or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass is 0% to 8.00%, preferably 0% to 3.00%, and more preferably 0% to 1.50%.

[0177] In some embodiments of the application, the content of CaO in the composition of the center of the strengthened glass-ceramic or the composition of the tension stress layer or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00% or 0.99% in terms of mole percent of oxide, or can be a value within a range of values formed by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the application can be obtained.

[0178] In the present application, Zr02 is an effective nucleating agent. During the heat treatment of the glass, Zr02 is precipitated in the form of crystals first, and the Zr02 crystals become the crystal nucleus for the growth of subsequent crystals. Within a certain range of glass composition, the content of Zr02 will affect the formation of the glass, affect the crystal shape, crystal type and crystal size of the glass-ceramic after heat treatment, etc. By adjusting the composition of the glass, Zr02 can be precipitated preferentially at the same temperature, and then the main crystal phase spinel crystal growth is realized. When the content of Zr02 is too low, it will affect the precipitation of the main crystal phase of the zinc-magnesium spinel solid solution; when the content of Zr02 is too high, it will cause the melting difficulty of the base glass to become larger, resulting in white unmelted substances in the base glass. In the present application, the molar percentage of Zr02 in the composition of the center of the strengthened glass-ceramic or the tensile stress layer, the composition of the glass-ceramic used to prepare the strengthened glass-ceramic, or the composition of the base glass is 3.00% to 6.00%, preferably 3.00% to 5.00%, and more preferably 3.10% to 4.00%.

[0179] In some embodiments of the present application, the content of Zr02 in the composition of the center of the strengthened glass-ceramic or the tensile stress layer, the composition of the glass-ceramic used to prepare the strengthened glass-ceramic, or the composition of the base glass can be 3.00%, 3.20%, 3.50%, 3.70%, 4.00%, 4.20%, 4.50%, 4.70%, 5.00%, 5.20%, 5.50%, 5.70%, 6.00%, 3.39%, 3.42%, 3.46%, 3.38%, 3.43%, or 3.48% in terms of molar percentage of oxide, or can be a value within a value range formed by any two of the above specific values as endpoints, as long as a glass-ceramic or a strengthened glass-ceramic with the required 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 range, as long as a glass-ceramic or a strengthened glass-ceramic with the required properties of the present application can be obtained.

[0180] In the present application, the increase of the content of Na20 helps to obtain higher surface compressive stress, while the melting temperature and the crystal precipitation temperature can be reduced. However, excessive addition of Na20 will cause the glass to be ceramized during annealing, or cause other impurities to be precipitated during heat treatment, which will affect the transmittance of the glass-ceramic. Too low content of Na20 will cause the heat treatment temperature to rise, and directly separate or precipitate impurities during heat treatment, resulting in a glass-ceramic with poor transparency or opaque effect. In the present application, the molar percentage of Na20 in the composition of the center of the strengthened glass-ceramic or the tensile stress layer, the composition of the glass-ceramic used to prepare the strengthened glass-ceramic, or the composition of the base glass is 2.00% to 10.00%, preferably 2.50% to 8.00%, and more preferably 3.00% to 6.00%.

[0181] In some embodiments of the application, the content of Na20 in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 3.39%, 3.43%, 3.47%, 3.38%, 5.39%, or 3.55% in terms of mole percent of oxide, or can be a value within a range defined by any two of the above specific values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the application is obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the application is obtained.

[0182] In the present application, Li20 helps to obtain a higher compressive stress layer depth and increase the Young's modulus; at the same time, it can reduce the melting temperature and the temperature of crystal precipitation, but excessive addition of Li20 can cause the glass to ceramize during annealing, or cause other impurity phases to precipitate during heat treatment, which affects the transmittance of the glass-ceramic, or cause the crystals to grow excessively during heat treatment, resulting in a decrease in the transmittance of the glass-ceramic. Too low an amount of Li20 can cause the heat treatment temperature to increase and the deep stress to decrease. In the present application, the mole percent of Li20 in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass is 3.00% to 12.00%, preferably 3.20% to 10.00%, and more preferably 3.50% to 6.00%.

[0183] In some embodiments of the present application, the content of Li20 in the composition of the center of the strengthened glass-ceramics or the composition of the tensile stress layer of the strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the strengthened glass-ceramics or the composition of the base glass can be 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 10.50%, 11.00%, 11.50%, 12.00%, 5.77%, 3.87%, 3.92%, 5.75%, 3.88%, 4.91%, 3.96% or 3.86% in terms of mole percent of oxide, or can be a value within a range defined by any two of the above specific values as endpoints, as long as a glass-ceramics or a strengthened glass-ceramics with 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 range, as long as a glass-ceramics or a strengthened glass-ceramics with desired properties of the present application can be obtained.

[0184] In the present application, K20 can be an optional component with a mole percent of 0% to 1.00%. In some embodiments, it is preferred that the composition of the center of the strengthened glass-ceramics or the composition of the tensile stress layer of the strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the strengthened glass-ceramics or the composition of the base glass does not contain K20.

[0185] In the present application, rare earth oxides Y2O3 and / or La2O3 can be optional components that can be added in appropriate amounts to improve the strength of the glass-ceramics. Y2O3 is an optional component that can improve the hardness and chemical stability of the glass-ceramics and inhibit crystallization during glass forming. Appropriate amounts of Y2O3 can improve the density of the glass phase and thus the overall strength of the glass-ceramics. Y2O3 can form a eutectic with ZrO2, which can reduce the problem of glass inhomogeneity caused by ZrO2 precipitation during melting in a furnace. However, excessive amounts of Y2O3 can affect the precipitation of the main crystal phase spinel crystals in the glass-ceramics, leading to a decrease in the optical properties of the glass-ceramics and a decrease in the chemical strengthening performance of the glass-ceramics. Appropriate amounts of La2O3 can improve the density of the glass-ceramics, improve the dielectric constant, mechanical strength, chemical stability, etc., increase the hardness and softening temperature. In the present application, the composition of the center of the strengthened glass-ceramics or the composition of the tensile stress layer of the strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the strengthened glass-ceramics or the composition of the base glass can have: a mole percent of Y2O3 of 0% to 15.00%, preferably 0% to 5.00%, more preferably 0% to 1.00%; and a mole percent of La2O3 of 0% to 15.00%, preferably 0% to 5.00%, more preferably 0% to 1.00%.

[0186] In some embodiments of the present application, the content of Y2O3 in the composition at the center of the strengthened glass-ceramic or the tensile stress layer, or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic, or the composition of the base glass can be 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 10.50%, 11.00%, 11.50%, 12.00%, 12.50%, 13.00%, 13.50%, 14.00%, 14.50%, 15.00%, or 0.19% in terms of mole percent of oxide, or can be a value within a range defined by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with 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 range, as long as a glass-ceramic or strengthened glass-ceramic with desired properties of the present application can be obtained.

[0187] In some embodiments of the present application, the content of La2O3 in the composition at the center of the strengthened glass-ceramic or the tensile stress layer, or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic, or the composition of the base glass can be 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 10.50%, 11.00%, 11.50%, 12.00%, 12.50%, 13.00%, 13.50%, 14.00%, 14.50%, 15.00%, or 0.19% in terms of mole percent of oxide, or can be a value within a range defined by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with 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 range, as long as a glass-ceramic or strengthened glass-ceramic with desired properties of the present application can be obtained.

[0188] In the present application, by adjusting and controlling the ratio relationship between the oxide components, adding appropriate amounts of Y2O3 and / or La2O3, on the basis of adjusting and controlling the content range of each oxide component, it is beneficial to improve the strength, hardness, stability and deformation resistance of the strengthened glass-ceramic.

[0189] In some embodiments of the present application, the sum of the mole percent of Y2O3 [Y2O3] and the mole percent of La2O3 [La2O3] in the composition at the center of the strengthened glass-ceramic or the composition of the glass-ceramic used to make the strengthened glass-ceramic or the composition of the base glass satisfies the following relationship: 0% < [Y2O3] + [La2O3] < 15.00%; preferably, 0% < [Y2O3] + [La2O3] < 5.00%, more preferably, 0% < [Y2O3] + [La2O3] < 1.00%.

[0190] In some embodiments, the sum of the mole percent of Y2O3 [Y2O3] and the mole percent of La2O3 [La2O3] in the composition at the center of the strengthened glass-ceramic or the composition of the glass-ceramic used to make the strengthened glass-ceramic or the composition of the base glass, [Y2O3] + [La2O3], can be 0.05%, 0.10%, 0.20%, 0.30%, 0.40%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 10.50%, 11.00%, 11.50%, 12.00%, 12.50%, 13.00%, 13.50%, 14.00%, 14.50%, 15.00%, or 0.38%, or a value within a range bounded by any two of the foregoing specific values, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained. It should be understood that in specific embodiments, any of the foregoing ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained.

[0191] In the present application, in order to obtain a strengthened glass-ceramic having excellent properties as desired in the present application, in addition to Y2O3 and La2O3, a metal oxide of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, or scandium, or a mixture of the foregoing metal oxides, can also be added to the composition of the glass-ceramic used to make the strengthened glass-ceramic or the composition of the base glass, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained. If the foregoing metal oxides are added to the composition of the glass-ceramic used to make the strengthened glass-ceramic or the composition of the base glass, these metal oxides should also be contained in the composition at the center of the strengthened glass-ceramic or the composition of the tension stress layer.

[0192] In some embodiments of the present application, since the addition of P2O5 can easily affect the optical properties of the glass-ceramics or strengthened glass-ceramics, the addition of B2O3, although can improve the melting effect of the base glass, can easily affect the toughness and other properties of the strengthened glass-ceramics, and the addition of TiO2 can easily result in the glass-ceramics or strengthened glass-ceramics exhibiting undesirable color. Therefore, it is preferred that the glass-ceramics or strengthened glass-ceramics of the present application do not contain P2O5, B2O3 or TiO2. In some embodiments, at the center of the strengthened glass-ceramics or the composition of the compressive stress layer, or the composition of the glass-ceramics used to prepare the strengthened glass-ceramics, or the composition of the base glass, in terms of mole percent of oxides: P2O5 is not contained, and / or, B2O3 is not contained, and / or, TiO2 is not contained.

[0193] In some embodiments of the present application, the crystallinity of the glass-ceramics or strengthened glass-ceramics is 30% to 55%, preferably 40% to 55%. In some embodiments, the crystallinity of the glass-ceramics or strengthened glass-ceramics can be 30%, 35%, 40%, 45%, 55%, 47%, 48%, 41%, 50%, 51% or 46%, or can be a value within a numerical range constituted by any two of the above specific numerical values as endpoints, as long as a glass-ceramics or 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 range, as long as a glass-ceramics or strengthened glass-ceramics with the desired properties of the present application can be obtained.

[0194] In the present application, "main crystal phase of zinc aluminate-magnesium aluminate spinel solid solution" or "zinc aluminate-magnesium aluminate spinel solid solution as the main crystal phase of glass-ceramics" or other similar expressions mean that the zinc aluminate-magnesium aluminate spinel solid solution accounts for more than 50% by mass of all crystal phases of the glass-ceramics or the strengthened glass-ceramics according to the embodiments of the present application. In some embodiments, the mass of the zinc aluminate-magnesium aluminate spinel solid solution accounts for more than 50% of all crystal phases of the glass-ceramics for preparing the strengthened glass-ceramics or the strengthened glass-ceramics, preferably, the mass of the zinc aluminate-magnesium aluminate spinel solid solution accounts for more than 70% of all crystal phases of the glass-ceramics for preparing the strengthened glass-ceramics or the strengthened glass-ceramics. For example, the mass fraction (or also referred to as the weight fraction) of the zinc aluminate-magnesium aluminate spinel solid solution crystal phase in all crystal phases of the glass-ceramics for preparing the strengthened glass-ceramics or the strengthened glass-ceramics can be 50%, 60%, 70%, 79%, 80%, 81%, 82%, 83%, 84%, 85% or 86%, or can be a value within a value range constituted by any two of the above specific values as end points, as long as a glass-ceramics or a strengthened glass-ceramics with the required 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 range, as long as a glass-ceramics or a strengthened glass-ceramics with the required performance of the present application can be obtained.

[0195] In some embodiments of the present application, the average crystal size in the glass-ceramics or the strengthened glass-ceramics is not more than 20 nm, preferably 1 nm to 15 nm, and more preferably 3 nm to 8 nm. In some embodiments, the average crystal size in the glass-ceramics or the strengthened glass-ceramics can be 4 nm, 5.6 nm, 5.7 nm, 6.9 nm, 6.4 nm, 7.3 nm, 5.6 nm, 6.6 nm, 6.1 nm or 5.5 nm, or can be a value within a value range constituted by any two of the above specific values as end points, as long as a glass-ceramics or a strengthened glass-ceramics with the required 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 range, as long as a glass-ceramics or a strengthened glass-ceramics with the required performance of the present application can be obtained.

[0196] By making the glass-ceramics or the strengthened glass-ceramics meet the desired crystallinity and appropriate average crystal size, it is beneficial to make the glass-ceramics or the strengthened glass-ceramics maintain excellent optical performance while meeting excellent mechanical strength performance and high intrinsic strength.

[0197] In some embodiments of the present application, the strengthened glass ceramic has a haze increase factor of less than 3.00, preferably a haze increase factor of less than 2.50, more preferably a haze increase factor of less than 2.10, after the sand abrasion test, compared to the haze of the strengthened glass ceramic before the sand abrasion test.

[0198] In some embodiments of the present application, the strengthened glass ceramic has a haze increase factor of less than 3.00, preferably a haze increase factor of less than 2.50, more preferably a haze increase factor of less than 2.10, after the sand abrasion test, compared to the haze of the strengthened glass ceramic before the sand abrasion test.

[0199] In some embodiments, the strengthened glass ceramic has a haze increase factor of less than 1.80, less than 1.60, less than 1.50, less than 1.20, or less than 1.00, after the sand abrasion test, compared to the haze of the strengthened glass ceramic before the sand abrasion test. In some embodiments, the haze increase factor can be 0.10, 0.20, 0.30, 0.40, 0.5, 0.6, 0.70, 0.80, 0.90, 1.00, 1.10, 1.20, 1.30, 1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, 0.22, 0.69, 1.15, 0.19, 1.46, 1.81, 1.56, 1.59, 2.03, 1.02, 0.76, 1.02, or 0.88, or a value within a range having any two of the above specific numeric values as endpoints, as long as a strengthened glass ceramic having the desired properties of the present application is obtained. It should be appreciated that in specific embodiments, any of the above ranges can be combined with any other range, as long as a strengthened glass ceramic having the desired properties of the present application is obtained.

[0200] After the foregoing introduces the composition, crystal phase and stress structure of the strengthened glass ceramic, the preparation method of the strengthened glass ceramic is introduced in detail.

[0201] In the present application, the preparation process of the strengthened glass ceramic mainly includes the preparation process of the glass ceramic and the chemical strengthening process, and the preparation process of the glass ceramic mainly includes the preparation process of the base glass and the heat treatment process of the base glass.

[0202] In the present application, the base glass can be prepared by using the forming method in the prior art, and the present application does not have any limitation thereon, for example, the forming method of the base glass can include but is not limited to the float method, the overflow method, the calendering process or the casting process. Illustratively, the components are mixed according to the formula, and after the melt forming, cooling and annealing treatment are performed, the base glass can be obtained.

[0203] Illustratively, the raw materials (industrial conventional raw materials) are configured according to the formula, a refining agent is added, and then the mixture is mixed for a period of time to obtain a raw material mixture with uniform mixture. The raw material mixture is placed in a platinum crucible, heated to 1450-1800°C, preferably the melting temperature is 1550-1680°C, and preferably the temperature is maintained for 3-15h, and then poured into a forming mold for cooling and forming, preferably cooled to 800-1000°C, and then placed in an annealing furnace for annealing treatment, preferably the annealing temperature is 500-700°C, and the annealing time is preferably 5-48h; and then the furnace is cooled to room temperature, and the base glass can be obtained. The person skilled in the art can select the type and amount of the refining agent according to the needs, and it does not require creative labor. Further, the refining agent 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 refining agent can be 0wt%-1wt% of the total amount of the raw material substances.

[0204] In some embodiments of the present application, the heat treatment process of the base glass can include nucleation treatment and / or crystallization treatment, and preferably nucleation treatment and crystallization treatment are used. In some embodiments, the crystallization treatment includes one-step crystallization treatment or two-step crystallization treatment.

[0205] In some embodiments of the present application, in order to obtain the desired physical and chemical properties of the glass ceramic, when the base glass is subjected to heat treatment, one-step heat treatment can be performed, or two-step or multi-step heat treatment can be performed. If one-step heat treatment is performed, it means that the nucleation treatment (i.e., nucleation treatment) is not performed separately, and one-step temperature rising is directly performed, and the nucleation and target crystal growth are performed at the temperature reached in the one-step temperature rising process, which can be understood as directly performing the crystallization treatment. If two-step heat treatment is performed, it means that two-step temperature rising process is performed, and the nucleation treatment (i.e., nucleation treatment) is performed first, and then the target crystal growth treatment (i.e., crystallization treatment) is performed.

[0206] In order to make the glass-ceramics precipitate the desired crystal phase, and obtain the desired physical and chemical properties, the nucleation treatment temperature can be 600-850°C, the nucleation treatment time can be 0-72h, preferably 0-10h; the crystallization treatment temperature can be 700-1000°C, the crystallization treatment time can be 0.10-24h, preferably 0.1-6h. When performing the heat treatment, the temperature rising rate is preferably controlled to be 5-15°C / min, more preferably the temperature rising rate is 10°C / min. The nucleation treatment temperature refers to the temperature at which the crystal nucleus can form. The crystallization treatment temperature refers to the temperature at which the target crystal can grow controllably.

[0207] After the heat treatment, the person skilled in the art can also perform other conventional steps to obtain the glass-ceramic sample / piece that meets the required specifications or requirements, for example, the sample / piece can be subjected to shaping treatment, cutting treatment (such as cutting using a multi-wire cutting machine), CNC machining treatment (computer numerical control), thinning treatment, or polishing treatment, etc.

[0208] In some embodiments of the present application, the glass-ceramic described above is subjected to a specific chemical strengthening treatment, and thus a strengthened glass-ceramic that meets the desired performance is obtained.

[0209] In the present application, the chemical strengthening treatment, i.e., the ion exchange method, is performed by immersing the glass-ceramic in a molten salt bath, so that the alkali metal ions with a smaller ionic radius in the glass-ceramic are exchanged with the alkali metal ions with a larger ionic radius in the molten salt bath, thereby forming a compressive stress layer on the surface of the glass-ceramic and obtaining a strengthened glass-ceramic with better mechanical properties.

[0210] In some embodiments of the present application, the chemical strengthening treatment can be performed by a single-step strengthening method or a multi-step strengthening method. The molten salt bath used in the chemical strengthening treatment is a molten salt bath containing sodium salt and / or potassium salt. Preferably, the chemical strengthening in the present application is performed by a two-step strengthening method, and the molten salt bath used in each step of the strengthening process is a pure salt bath containing sodium salt or potassium salt. Preferably, the temperature of the molten salt bath is 380-600°C, more preferably 400-500°C. In some embodiments of the present application, a certain amount (for example, 0wt%-0.5wt%) of lithium salt can be added to the salt bath. In some embodiments of the present application, the chemical strengthening treatment time is preferably 0.1h-48h, preferably 0.1h-24h. 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; and the lithium salt can be selected from at least one of lithium nitrate, lithium sulfate, and lithium carbonate, preferably lithium nitrate.

[0211] The glass-ceramics or strengthened glass-ceramics provided by the present application with excellent performance (especially excellent scratch resistance) can be used in electronic devices, including but not limited to mobile phones, tablet computers, palm game consoles, portable digital devices (such as digital cameras), vehicle center control, electronic whiteboard glass, smart home, smart wear (such as smart bracelet, smart watch, smart glasses), and can also be used in vehicles, aircraft or vessels, and can also be used in any desired glass-ceramic or strengthened glass-ceramic glassware. For example, it can be used in the display screen, cover glass, touch screen, glass inner screen or inner frame of an electronic device; for example, it can be used in the windshield of a vehicle, aircraft or vessel, such as the front windshield or side windshield. For example, it can be used in worktops, other surfaces, appliance doors, floor tiles, wall panels or storage containers, etc. Other surfaces can include but are not limited to exterior wall surfaces, stair tread surfaces, column facings or counter surfaces, etc., and storage containers can include but are not limited to cups, plates, medicine bottles or beverage bottles, etc.

[0212] For example, the glass-ceramics or strengthened glass-ceramics provided by the present application with excellent performance can be used to manufacture glassware. The glassware referred to herein can be regular or irregular, and those skilled in the art can manufacture it according to the needs.

[0213] For example, the glass-ceramics or strengthened glass-ceramics provided by the present application with excellent performance (especially excellent scratch resistance) can be used to manufacture cover glass, which can be a display screen cover, back cover or camera protection cover of an electronic device. For example, the glass-ceramics or strengthened glass-ceramics provided by the present application with excellent performance (especially excellent scratch resistance) can be used in electronic devices. Referring to FIGS. 2, 3, 4 and 8, in some embodiments of the present application, an electronic device is provided, which can be a mobile phone (as shown in FIG. 2), a tablet computer, a smart wearable device (as shown in FIG. 8), etc. The electronic device comprises a housing 1 assembled on the outer side of the electronic device, the housing 1 comprises a display screen cover 11 assembled on the front side and a back cover 12 assembled on the back side, and the display screen cover 11 is covered on the display module 4, wherein the display screen cover 11 and / or the back cover 12 are made of the aforementioned glass-ceramics or strengthened glass-ceramics. In the present application, the display screen cover 11 and the back cover 12 can be made of the aforementioned glass-ceramics or strengthened glass-ceramics entirely, or only partially. In the present application, the display screen can be a touch display screen, and the display screen cover 11 can be a protective cover plate arranged on the touch display screen. In the present application, the back cover 12 can cover only the back side of the electronic device (and the side away from the display screen), or can cover the back side and the side frame of the electronic device, and optionally, the back cover 12 can cover all the side frames around the electronic device, or can cover part of the side frames.

[0214] In some embodiments of the present application, as shown in FIG. 3, the electronic device can further include a camera assembly 2 located inside the housing 1, and the housing 1 can include a camera protective cover plate 13 covering the camera assembly 2 for protecting the camera assembly 2, and the camera protective cover plate 13 can be made of the aforementioned glass ceramic or strengthened glass ceramic. In the present application, the camera protective cover plate 13 can be partially made of the aforementioned glass ceramic or strengthened glass ceramic, or can be entirely made of the aforementioned glass ceramic or strengthened glass ceramic. In the present application, the camera protective cover plate 13 can be located on the front side of the electronic device, or can be located on the back side of the electronic device, depending on the location of the camera assembly 2. In some embodiments of the present application, the camera protective cover plate 13 can be in a separate structure from the display screen cover plate 11 or the back cover 12. In other embodiments of the present application, the camera protective cover plate 13 can be in an integrated structure with the display screen cover plate 11 or the back cover 12.

[0215] In some embodiments of the present application, as shown in FIG. 4, the electronic device can further include a middle frame 3 located between the display module 4 and the housing 1, and the middle frame 3 can be made of the aforementioned glass ceramic or strengthened glass ceramic.

[0216] In the embodiments of the present application, the display screen cover plate, the back cover, the camera protective cover plate, and the middle frame of the electronic device can be made of the aforementioned glass ceramic or strengthened glass ceramic, or any two of them can be made of the aforementioned glass ceramic or strengthened glass ceramic, or all three of them can be made of the aforementioned glass ceramic or strengthened glass ceramic, or all four of them can be made of the aforementioned glass ceramic or strengthened glass ceramic.

[0217] In some embodiments of the present application, the display screen cover plate, the back cover, the camera protective cover plate, or the middle frame of the electronic device can be 2D, 2.5D, 3D, or of a special shape. In some embodiments of the present application, the display screen cover plate, the back cover, the camera protective cover plate, or the middle frame of the electronic device can be of equal thickness or of unequal thickness.

[0218] The technical solutions of the present application are 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 cannot be understood as a limitation of the present application.

[0219] Embodiment 1

[0220] A strengthened glass ceramic is prepared by the following process:

[0221] (1) Preparation of base material glass:

[0222] Each raw material (industrial conventional raw material) was prepared according to the proportions of each component in Table 1, the total mass of the prepared raw material was 1000 g, 5 g of clarifying agent sodium chloride (NaCl) was added to the prepared raw material, and then the V-shaped mixer was mixed for 30 minutes to obtain a uniformly mixed raw material mixture.

[0223] The raw material mixture was transferred to a platinum crucible, then melted in the platinum crucible at 1650°C for 5 hours, then poured into a preheated molding mold at 300°C for cooling, cooled to 900°C, then placed in an annealing furnace at 600°C for annealing for 24 hours, and then cooled to room temperature in the furnace to obtain the base glass brick.

[0224] (2) Preparation of glass-ceramics:

[0225] According to the heat treatment process in Table 2, the base glass brick was placed in an annealing furnace, heated from room temperature to 750°C at a rate of 10°C / min for nucleation treatment, then heated to 755°C at a rate of 10°C / min for crystallization treatment, and then cooled to room temperature at a rate of 1°C / min. After holding at this temperature for 240 min, the glass-ceramic sample brick was obtained. The composition of the prepared glass-ceramics was the same as that of the base glass, which was shown in Table 1 in terms of mole percentage of oxides.

[0226] After the obtained glass-ceramic sample brick was subjected to cutting, CNC processing (the CNC instrument used in the present application was RCG500S), and polishing, the glass-ceramic samples / slices meeting the required specifications and requirements were prepared. In Examples 1-15 and Comparative Examples 1-20 of the present application, the glass-ceramic sample brick was subjected to the foregoing cold processing to prepare glass-ceramic samples / slices with a thickness of 0.70 mm, 0.40 mm, 0.90 mm, or 1.00 mm. Specifically, glass-ceramic polished slice samples with a size of 50 mm x 50 mm x 0.70 mm, 50 mm x 50 mm x 0.40 mm, 50 mm x 50 mm x 0.90 mm, 50 mm x 50 mm x 1.00 mm, φ46 mm x 0.70 mm, φ46 mm x 0.40 mm, φ46 mm x 0.90 mm, or φ46 mm x 1.00 mm were prepared. Among them, 50 mm x 50 mm x 0.70 mm is a square glass sheet with a length of 50 mm, a width of 50 mm, and a thickness of 0.70 mm; φ46 mm x 0.70 mm is a circular glass sheet with a diameter of 46 mm and a thickness of 0.70 mm. The rest of the size has a similar meaning.

[0227] Test conditions of the glass-ceramic samples / slices obtained in Example 1:

[0228] The crystalline phase composition, crystallinity, average crystal size, transmittance (at 550 nm wavelength) and density of the glass-ceramic samples / slices were tested, respectively, and the results are shown in Table 2.

[0229] (3) Preparation of strengthened glass-ceramics: The obtained glass-ceramic samples / slices were preheated in a strengthening furnace cavity for 5 min according to the chemical strengthening process in Table 3, and then quickly placed in a 455℃ molten salt bath for first-step strengthening treatment. The composition of the molten salt bath for the first-step strengthening treatment was 100wt% NaNO3, and the strengthening treatment time was 3.5 h. After the first-step strengthening treatment, the glass-ceramic samples / slices were cooled, washed and dried to ensure the absence of sodium salt. Then, the glass-ceramic samples / slices were placed in a 420℃ molten salt bath for second-step strengthening treatment. The composition of the molten salt bath for the second-step strengthening treatment was 100wt% KNO3, and the strengthening treatment time was 3.5 h. After the second-step strengthening treatment, the glass-ceramic samples / slices were taken out and slowly cooled to room temperature on the furnace body of the strengthening furnace. The salt wrapped on the surface of the glass-ceramic was washed off with clean water, and the glass-ceramic samples / slices were dried to obtain the strengthened glass-ceramics.

[0230] Test conditions for the strengthened glass-ceramics obtained in Example 1:

[0231] I. The CS_20, CS_30, CS_50 and DOL_0 of the strengthened glass-ceramics were measured on an SLP-2000 stress meter (which uses a light source wavelength of 518 nm, SOC = 25.5 (nm / cm) / MPa, refractive index set to 1.60, and exposure time: 300 μsec), and the results are shown in Table 3.

[0232] II. The DOL_K of the strengthened glass-ceramics was measured by micro-area composition analysis using characteristic X-rays generated by electron beam action on the samples / slices on a Shimadzu electron probe EPMA-1720HT, and the results are shown in Table 3.

[0233] According to the measured CS_20, CS_30, CS_50, DOL_0 and DOL_K, the value of Formula X was calculated, and the results are shown in Table 3.

[0234] III. The Vickers hardness of the strengthened glass-ceramics was tested, and the haze increase multiple of the strengthened glass-ceramics was calculated after scratch testing, and the results are shown in Table 3.

[0235] Examples 2-15

[0236] Each of Examples 2-15 was performed according to Example 1, except that the raw material composition, different process parameters and their corresponding test results of each example are shown in Tables 1-3.

[0237] The XRD patterns of the glass-ceramics and the strengthened glass-ceramics of Example 1 are compared in Figure 5. It can be seen from the figure that ① the main crystal phase of the glass-ceramics and the strengthened glass-ceramics is a zinc-aluminum spinel-magnesium-aluminum spinel solid solution (Zn, Mg) Al2O4, and the secondary crystal phase is ZrO2; ② the XRD patterns of the glass-ceramics and the strengthened glass-ceramics are basically coincident, and the crystal phase structure is basically unchanged before and after chemical strengthening.

[0238] The transmittance curves of the glass-ceramics and the strengthened glass-ceramics of Example 1 are compared in Figure 6. It can be seen from the figure that the glass-ceramics and the strengthened glass-ceramics prepared therefrom are both transparent in the visible light range, both have high transmittance, and the transmittance is basically unchanged before and after chemical strengthening.

[0239] Comparative Examples 1-3, Comparative Examples 5-20

[0240] Each of the comparative examples is prepared by referring to Example 1, except that the raw material compositions, different process parameters and the corresponding test results of each comparative example are shown in Tables 1-3.

[0241] Comparative Example 4 is a commercially available coated glass product (AF-coated glass product) purchased directly.

[0242] The micrographs of the scratch points of the strengthened glass-ceramics provided by Example 1, Example 2, Comparative Example 1 and Comparative Example 2 after the sandstone scratch test are shown in Figure 7. The black points in the figure are scratch points, or also called damage points, such as the points circled in the figure. Wherein a is the micrograph of the scratch point of Example 1, b is the micrograph of the scratch point of Example 2, c is the micrograph of the scratch point of Comparative Example 1, and d is the micrograph of the scratch point of Comparative Example 2. It can be seen from the figure that the scratch resistance of the strengthened glass-ceramics provided by the examples is significantly better than that of the comparative examples.

[0243] The real object comparison chart of the strengthened glass-ceramics provided by Example 4 and Comparative Example 2 after the sandstone scratch test is shown in Figure 9. It can be seen from Figure 9 that the scratch resistance of the strengthened glass-ceramics provided by the examples is significantly better than that of the comparative examples. After the scratch test, the optical performance of the strengthened glass-ceramics of the examples is less affected, while the optical performance of the strengthened glass-ceramics of the comparative examples is more affected.

[0244] Table 1 Note: In Table 1, the oxide content of "0%" means that the component is not intentionally or deliberately added to the glass composition during the initial batching process, but the component may exist as an impurity.

[0245] Table 2 Note: In Table 2, " / " means that the operation is not performed, or the feature is not contained, or the test of the related parameter is not performed.

[0246] Table 3 Note: 1. In Table 3,

[0247] 2. In Table 3, the composition of the salt bath component is in mass percentage, for example, "50% NaNO3+50% KNO3" means 50wt% of NaNO3and 50wt% of KNO3.

[0248] 3. In Table 3, the strengthening process is written in the form of "salt bath composition + strengthening temperature + strengthening time", for example, "100% NaNO3-455℃-3.5h" means strengthening in a 100wt% NaNO3salt bath at 455℃ for 3.5h.

[0249] 4. In the strengthening process of Comparative Example 1 and Comparative Example 2, "0.03% LiNO3" in the salt bath component "70% KNO3+30% NaNO3+0.03% LiNO3" means that 0.03wt% of LiNO3is added based on the total mass of KNO3and NaNO3.

[0250] 5. " / " in Table 3 means that the operation is not performed or the feature is not contained or the test of the related parameter is not performed.

[0251] 6. Comparative Example 4 is a commercially available coated glass product (AF-coated glass product) purchased.

[0252] From the above Table 1-Table 3, it can be seen that the embodiments of the present application can impart high intrinsic strength (or also known as inherent strength) to the strengthened glass ceramic by making the strengthened glass ceramic meet the specific crystal phase structure and by taking zinc aluminate-magnesium aluminate spinel solid solution as the main crystal phase of the glass ceramic. Meanwhile, the embodiments of the present application can make the surface of the strengthened glass ceramic with high intrinsic strength have a specific stress distribution structure by making the stress at different depths of the surface of the strengthened glass ceramic, the K ion diffusion depth (or also known as K ion exchange (layer) depth) and the depth of the compressive stress layer meet the requirements of formula X, and thus the strengthened glass ceramic has excellent scratch resistance. In the present application, the scratch resistance of the products of the embodiments and the comparative examples is embodied / characterized by the haze increase multiple after the scratch test, the greater the haze increase multiple, the worse the scratch resistance of the product, the more serious the damage of the product in the scratch test, and the smaller the haze increase multiple, the better the scratch resistance of the product, the less the damage of the product in the scratch test. The reason why the haze increase multiple can embody the scratch resistance is mainly because the scratch on the surface of the glass product will directly affect the haze of the glass product, affecting the optical performance and display effect of the glass product.

[0253] In the schemes of Comparative Examples 1 to 20, the crystalline phase structure or surface stress distribution of the strengthened glass ceramic or strengthened glass or coated glass does not meet the specific requirements of the present application, and the scratch resistance of the final strengthened glass ceramic is obviously not as good as that of the embodiments meeting the scheme requirements of the present application.

[0254] The data of each embodiment and comparative example are analyzed as follows:

[0255] In Example 1, after chemical strengthening treatment, the Vickers hardness of the obtained strengthened glass ceramic is 850 kgf / mm2. The chemical strengthening treatment forms a compressive stress structure on the surface of the glass ceramic, which can improve the mechanical properties of the glass ceramic. The strengthened glass ceramic obtained in Example 1 is subjected to scratch testing with sandstone, and after the scratch testing, the haze increase multiple of the strengthened glass ceramic is only 0.22, which indicates that the strengthened glass ceramic of Example 1 has excellent scratch resistance, and the friction between the sandstone and the surface of the strengthened glass ceramic has almost no damage. The surface micrograph of the strengthened glass ceramic of Example 1 after scratch testing is shown in Figure 7a.

[0256] In Example 2, the Vickers hardness of the obtained strengthened glass ceramic is 810 kgf / mm2. The strengthened glass ceramic is subjected to scratch testing with sandstone, and the testing conditions are the same as those of Example 1. After the scratch testing, the haze increase multiple of the strengthened glass ceramic is 0.69. The friction between the sandstone and the surface of the strengthened glass ceramic has almost no damage, and the surface micrograph of the strengthened glass ceramic of Example 2 after scratch testing is shown in Figure 7b.

[0257] Since the other embodiments and Examples 1 and 2 are basically similar, no further description is given here.

[0258] In Comparative Example 1, the obtained glass ceramic is based on petalite and lithium disilicate as the main crystalline phase. After chemical strengthening treatment, the Vickers hardness of the obtained strengthened glass ceramic is 712 kgf / mm2, which is obviously lower than that of the glass ceramic based on spinel as the main crystalline phase. The strengthened glass ceramic obtained in Comparative Example 1 is subjected to scratch testing with sandstone, and the testing conditions are the same as those of Example 1. After the scratch testing, the haze increase multiple of the strengthened glass ceramic is 6.5, which indicates that the scratch resistance of the strengthened glass ceramic of Comparative Example 1 is not as good as that of the embodiments of the present application. After the scratch testing with sandstone, the surface of the strengthened glass ceramic of Comparative Example 1 is severely damaged, resulting in a significant increase in haze. The surface micrograph of the strengthened glass ceramic of Comparative Example 1 after scratch testing is shown in Figure 7c.

[0259] Comparative Example 2 has the same crystal phase composition as Comparative Example 1. After chemical strengthening, the surface stress level of the strengthened glass ceramic prepared in Comparative Example 2 is higher than that of Comparative Example 1, and the Vickers hardness of the strengthened glass ceramic is 730 kgf / mm2. The strengthened glass ceramic prepared in Comparative Example 2 is subjected to the scratch test with sandstone, and the test conditions are the same as those of Example 1. After the scratch test, the haze increase multiple of the strengthened glass ceramic is 9.72. Like Comparative Example 1, the scratch resistance of the strengthened glass ceramic of Comparative Example 2 is not as good as that of the scheme of the present application. After the sandstone scratch test, the surface of the strengthened glass ceramic of Comparative Example 2 is also severely damaged, resulting in a significant increase in the haze thereof. The surface micrograph of the strengthened glass ceramic of Comparative Example 2 after the scratch test is shown as d in FIG. 7.

[0260] In Comparative Example 3, a strengthened glass without crystals is provided, and the performance thereof is relatively good. After chemical strengthening, the Vickers hardness of the obtained strengthened glass is 685 kgf / mm2, which is significantly lower than that of the glass ceramic with spinel as the main crystal phase. The strengthened glass prepared in Comparative Example 3 is subjected to the scratch test with sandstone, and the test conditions are the same as those of Example 1. After the scratch test, the haze increase multiple of the strengthened glass is 17.67. This indicates that the scratch resistance of the strengthened glass of Comparative Example 3 is not as good as that of the scheme of the present application.

[0261] In Comparative Example 4, a commercially available coated glass product is provided, specifically an AF-coated glass product, and the Vickers hardness thereof is 598 kgf / mm2. The coated glass provided in Comparative Example 4 is subjected to the scratch test with sandstone, and the test conditions are the same as those of Example 1. After the scratch test, the AF coating on the surface of the coated glass is ground off by the sandstone, and the haze increase multiple of the coated glass is 8.9. Although the coated glass is more resistant to scratching than the strengthened glass of Comparative Example 3 without coating, the scratch resistance thereof is not as good as that of the strengthened glass ceramic of the scheme of the present application.

[0262] Comparative Examples 5 to 20 are all glass ceramics of the spinel system, but because the composition of the glass ceramic and / or the surface stress distribution structure of the prepared strengthened glass ceramic does not meet the requirements of the present application, the value of Formula X related to the surface stress distribution is either too large or too small, and the scratch resistance of the finally prepared strengthened glass ceramic is obviously not as good as that of the scheme of the present application.

[0263] The above merely illustrates the specific embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. Industrial applicability

[0264] In the present application, by taking the zinc aluminum spinel-magnesium aluminum spinel solid solution as the main crystal phase of the glass ceramic, the glass ceramic can be endowed with high intrinsic strength (or also known as inherent strength). At the same time, by making the stress, K ion diffusion depth (or also known as K ion exchange (layer) depth) and the depth of the compressive stress layer of the surface of the strengthened glass ceramic with the main crystal phase of the zinc aluminum spinel-magnesium aluminum spinel solid solution meet the requirements of formula X, the surface of the strengthened glass ceramic with high intrinsic strength has a specific stress distribution structure, and thus the strengthened glass ceramic has excellent scratch resistance. The application of the strengthened glass ceramic in electronic devices, such as mobile phones, smart watches and other electronic devices, is conducive to improving the service life and user experience of the electronic devices.

Claims

1. A strengthened glass ceramic, wherein the strengthened glass ceramic includes a main crystal phase of a zinc aluminate-magnesium aluminate spinel solid solution and a sub-crystal phase of zirconia. The strengthened glass ceramic has a compressive stress layer on the surface and a tensile stress in the interior; the strengthened glass ceramic satisfies: 1.50≤X≤4.70, preferably 1.50≤X≤4.00, more preferably 1.50≤X≤3.60; wherein CS_20 is the compressive stress value at a depth of 20 pm from the main surface of the self-strengthening glass ceramic, in MPa; CS_30 is the compressive stress value at a depth of 30 pm from the main surface of the self-strengthening glass ceramic, in MPa; CS_50 is the compressive stress value at a depth of 50 pm from the main surface of the self-strengthening glass ceramic, in MPa; DOL_0 is the depth of the compressive stress layer of the strengthened glass ceramic, in pm; DOL_K is K + Diffusion depth in μm; in the formula X, the data are substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit is not involved in the calculation.

2. The strengthened glass ceramic of claim 1, wherein, the thickness t of the strengthened glass ceramic is 0.30 mm to 2.00 mm, preferably the thickness t is 0.35 mm to 1.50 mm, more preferably the thickness t is 0.40 mm to 1.00 mm; and / or, the strengthened glass ceramic is 2D, 2.5D, 3D or special-shaped.

3. The strengthened glass ceramic of claim 1 or 2, wherein, the strengthened glass ceramic satisfies: 70.00 MPa≤CS_20≤250.00 MPa, preferably 75.00 MPa≤CS_20≤245.00 MPa, more preferably 80.00 MPa≤CS_20≤240.00 MPa; and / or, 60.00 MPa≤CS_30≤240.00 MPa, preferably 65.00 MPa≤CS_30≤230.00 MPa, more preferably 70.00 MPa≤CS_30≤221.00 MPa; and / or, 50.00 MPa≤CS_50≤210.00 MPa, preferably 55.00 MPa≤CS_50≤200.00 MPa, more preferably 59.00 MPa≤CS_50≤185.00 MPa; and / or, 5.00 pm≤DOL_K≤25.00 pm, preferably 7.00 pm≤DOL_K≤23.00 pm, more preferably 9.00 pm≤DOL_K≤21.00 pm; and / or 0.17t≤DOL_0≤0.25t, preferably 0.19t≤DOL_0≤0.25t, t being the thickness of the strengthened glass ceramic; and / or, 65.00 pm≤DOL_0≤240.00 pm, preferably 70.00 pm≤DOL_0≤225.00 pm, more preferably 75.00 pm≤DOL_0≤215.00 pm.

4. The strengthened glass ceramic of any one of claims 1-3, wherein, The strengthened glass-ceramic has a Vickers hardness greater than or equal to 750 kgf / mm 2 , preferably, the strengthened glass-ceramic has a Vickers hardness greater than or equal to 800 kgf / mm 2 .

5. The strengthened glass ceramic of any one of claims 1-4, wherein, the strengthened glass ceramic is transparent in the visible wavelength range, preferably when the thickness t of the strengthened glass ceramic is 0.40 mm to 1.00 mm, the transmittance of the strengthened glass ceramic at a wavelength of 550 nm is ≥85%, preferably ≥89%.

6. The strengthened glass ceramic of any one of claims 1-5, wherein, the composition at the center or the tensile stress layer of the strengthened glass ceramic comprises, in terms of molar percentage of oxides: SiO2: 40.00% to 50.00%, Al2O3: 20.00% to 30.00%, MgO: 3.00% to 8.00%, ZnO: 8.00% to 12.00%, BaO: 0% to 8.00%, CaO: 0% to 8.00%, ZrO2: 3.00% to 6.00%, Na2O: 2.00% to 10.00%, Li2O: 3.00% to 12.00%, K2O: 0% to 1.00%, Y2O3: 0% to 15.00%, and La2O3: 0% to 15.00%.

7. The strengthened glass ceramic of any one of claims 1-6, wherein, The composition at the center of the strengthened glass-ceramic or of the tensile stress layer comprises, in mole percent of oxides: the mole percent of SiO2 is comprised between 41.00% and 48.00%, preferably between 42.00% and 47.00%; and / or, the mole percent of Al2O3 is comprised between 22.00% and 29.00%, preferably between 25.00% and 28.00%; and / or, the mole percent of MgO is comprised between 4.00% and 7.00%, preferably between 5.00% and 6.00%; and / or, the mole percent of ZnO is comprised between 8.50% and 11.50%, preferably between 9.00% and 11.00%; and / or, the mole percent of BaO is comprised between 0.50% and 5.00%, preferably between 1.00% and 4.00%; and / or, the mole percent of CaO is comprised between 0% and 3.00%, preferably between 0% and 1.50%; and / or, the mole percent of ZrO2 is comprised between 3.00% and 5.00%, preferably between 3.10% and 4.00%; and / or, the mole percent of Na2O is comprised between 2.50% and 8.00%, preferably between 3.00% and 6.00%; and / or, the mole percent of Li2O is comprised between 3.20% and 10.00%, preferably between 3.50% and 6.00%; and / or, the mole percent of Y2O3 is comprised between 0% and 5.00%, preferably between 0% and 1.00%; and / or, the mole percent of La2O3 is comprised between 0% and 5.00%, preferably between 0% and 1.00%.

8. The strengthened glass ceramic of any one of claims 1-7, wherein, The composition at the center of the strengthened glass-ceramic or of the tensile stress layer comprises Y2O3 and / or La2O3, the mole percent of Y2O3 [Y2O3] and the mole percent of La2O3 [La2O3] satisfying the following relationship: 0% < [Y2O3] + [La2O3] < 15.00%; preferably, 0% < [Y2O3] + [La2O3] < 5.00%, more preferably, 0% < [Y2O3] + [La2O3] < 1.00%.

9. The strengthened glass ceramic of any one of claims 1-8, wherein, The composition of the central part of the strengthened glass ceramic or the tensile stress layer satisfies: the value of [Y2O3] + [La2O3] is 0% or 0.38%.

10. The strengthened glass ceramic of any one of claims 1 to 9, wherein, The composition of the strengthened glass ceramic contains no P2O5, and / or contains no B2O3, and / or contains no TiO2, in terms of mole percent of oxides.

11. The strengthened glass ceramic of any one of claims 1 to 10, wherein, The crystallinity of the strengthened glass ceramic is 30% to 55%, preferably 40% to 55%; and / or, The average crystal size in the strengthened glass ceramic is not more than 20 nm, preferably 1 nm to 15 nm, and more preferably 3 nm to 8 nm.

12. The strengthened glass ceramic of any one of claims 1-11, wherein, The strengthened glass ceramic satisfies: CS_20 is 104.13 MPa, 83.36 MPa, 90.30 MPa, 190.30 MPa, 203.57 MPa, 101.89 MPa, 80.76 MPa, 111.28 MPa, 122.29 MPa, 142.68 MPa, 111.31 MPa, 162.64 MPa, 172.84 MPa, 238.66 MPa or 131.91 MPa; and / or, CS_30 is 95.34 MPa, 76.40 MPa, 78.38 MPa, 168.38 MPa, 187.61 MPa, 93.58 MPa, 73.53 MPa, 99.60 MPa, 110.58 MPa, 116.61 MPa, 103.81 MPa, 149.28 MPa, 149.98 MPa, 220.19 MPa or 124.52 MPa; and / or, CS_50 is 78.00 MPa, 62.67 MPa, 69.80 MPa, 99.80 MPa, 156.09 MPa, 77.19 MPa, 59.24 MPa, 79.80 MPa, 87.68 MPa, 66.34 MPa, 88.96 MPa, 123.29 MPa, 124.92 MPa, 184.10 MPa or 109.86 MPa; and / or, DOL_K is 12.20 μm, 10.40 μm, 9.60 μm, 14.10 μm, 13.30 μm, 12.80 μm, 11.90 μm, 11.50 μm, 12.20 μm, 10.10 μm, 14.20 μm, 12.50 μm, 12.80 μm, 16.30 μm or 20.30 μm; and / or, DOL_0 is 150.06 μm, 151.72 μm, 153.34 μm, 159.04 μm, 148.22 μm, 156.93 μm, 150.10 μm, 153.34 μm, 153.68 μm, 78.50 μm, 181.56 μm, 182.52 μm, 181.75 μm, 188.84 μm or 214.61 μm; and / or, The value of Formula X is 1.90, 1.56, 2.35, 3.24, 2.07, 1.92, 1.91, 2.27, 2.21, 3.51, 1.79, 2.02, 3.43, 2.59, or 2.

18.

13. The strengthened glass ceramic of any one of claims 1-12, wherein, the Vickers hardness of the strengthened glass ceramic is 850 kgf / mm 2 , 810 kgf / mm 2 , 821 kgf / mm 2 , 824 kgf / mm 2 , 806 kgf / mm 2 , 812 kgf / mm 2 , 811 kgf / mm 2 , 823 kgf / mm 2 , 804 kgf / mm 2 , 816 kgf / mm 2 , 845 kgf / mm 2 , 814 kgf / mm 2 , 816 kgf / mm 2 , or 840 kgf / mm 2 .

14. The strengthened glass ceramic of any one of claims 1 to 13, wherein, The composition at the center or the tensile stress layer of the strengthened glass ceramic comprises, in mole percent of oxides: the mole percent of SiO2is 45.31%, 45.76%, 46.29%, 45.13%, 45.85%, 46.76%, or 42.52%; and / or, the mole percent of Al2O3is 25.80%, 27.03%, 26.36%, 25.70%, 26.10%, 26.62%, or 27.36%; and / or, the mole percent of MgO is 5.47%, 5.52%, 5.59%, 5.45%, 5.53%, 5.64%, or 5.80%; and / or, the mole percent of ZnO is 9.71%, 9.80%, 10.91%, 9.67%, 9.82%, 9.92%, 10.02%, or 9.96%; and / or, the mole percent of BaO is 1.16%, 1.17%, 0%, or 3.47%; and / or, the mole percent of CaO is 0% or 0.99%; and / or, the mole percent of ZrO2is 3.39%, 3.42%, 3.46%, 3.38%, 3.43%, 3.50%, or 3.48%; and / or, the mole percent of Na2O is 3.39%, 3.43%, 3.47%, 3.38%, 5.39%, 3.50%, or 3.55%; and / or, the mole percent of Li2O is 5.77%, 3.87%, 3.92%, 5.75%, 3.88%, 4.91%, 3.96%, or 3.86%; and / or, the mole percent of Y2O3is 0% or 0.19%; and / or, the mole percent of La2O3is 0% or 0.19%.

15. The strengthened glass ceramic of any one of claims 1 to 14, wherein, The strengthened glass ceramic has a haze increase multiple of less than 3.00, preferably a haze increase multiple of less than 2.50, more preferably a haze increase multiple of less than 2.10, after a sand abrasion test, compared to the haze of the strengthened glass ceramic before the sand abrasion test; wherein the sand abrasion test refers to placing the strengthened glass ceramic and 1 kg of silica sand in an oscillating abrasion tester for the abrasion test, the oscillating frequency of the oscillating abrasion tester is 150 revolutions / min, the time of the sand abrasion test is 10 min; the haze increase multiple = (the final haze of the strengthened glass ceramic after the sand abrasion test - the initial haze of the strengthened glass ceramic before the sand abrasion test) / the initial haze of the strengthened glass ceramic before the sand abrasion test.

16. A cover glass, characterized by The cover glass is made of the strengthened glass ceramic according to any one of claims 1-15, or the cover glass comprises the strengthened glass ceramic according to any one of claims 1-15.

17. An electronic device, comprising: The electronic device comprises the strengthened glass ceramic according to any one of claims 1-15.

18. The electronic device of claim 17, wherein, The electronic device includes a housing including the strengthened glass-ceramic of any of claims 1-15.

19. The electronic device of claim 18, wherein, The housing includes a display screen cover that includes the strengthened glass-ceramic of any of claims 1-15.

20. The electronic device of claim 18 or 19, wherein, The housing includes a back cover that includes the strengthened glass-ceramic of any of claims 1-15.

21. The electronic device of any of claims 18-20, wherein, The electronic device further includes a camera assembly, the housing includes a camera protection cover that covers the camera assembly, the camera protection cover includes the strengthened glass-ceramic of any of claims 1-15.

22. The electronic device of any of claims 17-21, wherein, The electronic device further includes a middle frame that includes the strengthened glass-ceramic of any of claims 1-15.

23. A glass article, characterized by, The glass article includes the strengthened glass-ceramic of any of claims 1-15.

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