Lithium-free transparent spinel microcrystalline glass, preparation method and application thereof

Abstract

The present application relates to the technical field of glass-ceramics, in particular to a lithium-free transparent spinel glass-ceramics, a preparation method and application thereof. The lithium-free transparent spinel glass-ceramics is obtained by heat treatment of a base glass, and spinel crystal is the main crystal phase. The composition of the glass-ceramics contains the following oxides in mol%: SiO2 38.00-48.00%, Al2O3 25.50-30.00%, ZrO2 3.00-5.00%, MgO 5.00-8.00%, ZnO 8.00-14.00%, Na2O 7.20-14.00%, B2O3 3.00-8.00%, K2O 0-2.00%, and Y2O3 0-1.00%, and basically no Li2O. The glass-ceramics of the present application does not use high-cost lithium, and can obtain excellent surface and deep stress characteristics and excellent drop impact resistance through chemical strengthening.

Description

[0001] The present patent application is a divisional application of the patent application with application number 202211738867.8, application date December 30, 2022, and the title of "Lithium-free transparent spinel microcrystalline glass and preparation method and application thereof". TECHNICAL FIELD

[0002] The present application relates to the technical field of microcrystalline glass, in particular to a lithium-free transparent spinel microcrystalline glass that can be chemically strengthened, and a preparation method and application thereof. BACKGROUND

[0003] With the gradual thinning of electronic devices, the performance requirements for cover glasses are gradually increasing. For electronic cover glasses, excellent surface stress characteristics and excellent deep stress characteristics are required to achieve high mechanical performance. Among them, excellent deep stress characteristics are a necessary condition for cover glasses to achieve excellent impact resistance, such as excellent drop resistance.

[0004] Microcrystalline glass (glass ceramic) materials have become a better choice for screen covers due to their excellent mechanical properties and light transmittance. Among the many microcrystalline glasses, spinel microcrystalline glass with spinel as the main crystal phase has gradually attracted attention from industry insiders due to its high Young's modulus and shear modulus.

[0005] In order to make spinel microcrystalline glass meet the requirements of screen covers, researchers have attempted to chemically strengthen and toughen it. The main method is to first introduce lithium oxide and / or sodium oxide into the base glass, and then exchange lithium ions in the base glass with sodium ions in the salt bath, and / or exchange sodium ions in the base glass with potassium ions in the salt bath to achieve chemical strengthening.

[0006] Through research, the inventors found that using lithium ions to achieve chemical strengthening and toughening has many drawbacks. First, the radius difference between Li ions and Na ions is about 22 pm, and the radius difference between Na ions and K ions is about 40 pm. The stress performance is due to the "jamming" effect caused by ion exchange, so under the same exchange amount, the stress performance generated by Li ion and Na ion exchange is far less than that generated by Na ion and K ion exchange. Second, if you want to rely on Li ion and Na ion exchange to obtain high stress performance, you need to add a high content of lithium oxide to the base glass. Li2O is expensive, and the use of a large amount of lithium oxide will result in high glass costs. Third, if the base glass contains a large amount of Li, it is easy to cause the base glass to precipitate quartz, quartz solid solution and other impurities that affect the transmittance of the microcrystalline glass when the base glass is heat treated to obtain a microcrystalline glass, resulting in poor optical performance of the microcrystalline glass.

[0007] For the prior art scheme of using sodium ions to realize chemical strengthening toughening, the inventors found that the deep stress characteristics are poor, and the anti-drop impact effect is not ideal. For example, the application CN111908793A discloses a glass-ceramic with spinel crystal phase, the components are SiO2: 50-70 mol%, Al2O3: 5-21 mol%, Na2O: 6-21 mol%, ZnO: 2-12 mol%, TiO2: 0.5-10 mol%, MgO: 0-10 mol%; a large amount of Na2O is added. However, after chemical strengthening, the glass-ceramic can only obtain a compression stress layer depth of not higher than 40 microns, the deep stress characteristics are poor, and after drop impact, it is easily broken, and it is difficult to achieve excellent anti-drop impact effect.

[0008] In addition, the inventors also found that the existing transparent spinel microcrystalline glass requires a heat treatment temperature, mainly the crystallization temperature, of usually 900°C or even higher during preparation, which greatly limits the mass production of the spinel microcrystalline glass, and ordinary roller kiln cannot successfully mass-produce it. SUMMARY

[0009] Based on the above research, in order to improve the economic benefits and avoid the drawbacks of using lithium ions to realize chemical strengthening toughening in spinel microcrystalline glass, the inventors thought of not using lithium oxide but using sodium ions to realize chemical strengthening toughening of spinel microcrystalline glass.

[0010] However, the transparent spinel microcrystalline glass in the prior art that only uses sodium ions to realize chemical strengthening toughening has poor anti-drop performance, which cannot meet the requirements of screen cover plate for drop impact performance; and the existing transparent spinel microcrystalline glass has a crystallization temperature higher than 900°C, which affects the mass production performance.

[0011] The inventors found through in-depth research that the existing spinel microcrystalline glass containing only Na cannot achieve a high stress depth after chemical strengthening, the deep stress characteristics are poor, and the anti-drop performance is poor, mainly because the existing spinel microcrystalline glass has a microstructure that limits the depth of Na ions entering the glass interior and affects the depth of Na ion and K ion exchange. The volume of [AlO4] tetrahedron is larger than that of [SiO4], and theoretically, if the content of Al2O3 is increased, the ion exchange channel should be widened and the diffusion of Na ions should be promoted. However, the inventors found that a large amount of Al2O3 will greatly increase the melting difficulty of the base glass, especially without Li2O fluxing. Because the fluxing effect of Na2O is not as good as that of Li2O, and the melting difficulty of Al2O3 is greater than that of SiO2. A large amount of Na2O is introduced to play a fluxing effect, which will lead to uncontrollable crystallization and ceramicization of the base glass during forming or annealing.

[0012] To this end, the inventors have continuously adjusted the formulation, adjusted the amount of each oxide and the amount ratio of each oxide in the formulation, optimized the glass formulation, and taken into account the melting effect, stress effect, optical effect and mechanical properties, and finally developed a lithium-free transparent spinel microcrystalline glass with a specific structure, good overall uniformity and high intrinsic strength. The microcrystalline glass not only has lower preparation cost than existing lithium-containing spinel microcrystalline glass, excellent optical performance, high intrinsic strength, but also can obtain a strengthened microcrystalline glass with excellent surface stress characteristics and deep stress characteristics through chemical strengthening, thereby making the strengthened microcrystalline glass have excellent mechanical properties, such as excellent anti-drop impact performance. At the same time, the optimized glass formulation of the present application can obtain a transparent microcrystalline glass with a main crystal phase of zinc-magnesium spinel solid solution and excellent optical performance and high intrinsic strength at a heat treatment temperature of not more than 800℃. Compared with the prior art, the optimized spinel microcrystalline glass formulation scheme of the present application can significantly reduce the heat treatment temperature required for preparing the target microcrystalline glass, meet the development needs of energy saving and carbon reduction in the industry, improve the mass producibility of transparent spinel microcrystalline glass, and ensure the excellent optical performance and high intrinsic strength of the microcrystalline glass.

[0013] Specifically, the present application provides the following technical solutions:

[0014] In one aspect, the present application provides a lithium-free transparent spinel microcrystalline glass, which is prepared by heat treatment of a base glass, and contains spinel crystals, which are the main crystal phase of the microcrystalline glass.

[0015] The lithium-free transparent spinel microcrystalline glass contains the following oxides in the following proportions in mol%: SiO238.00-48.00%, Al2O3 25.50-30.00%, ZrO2 3.00-5.00%, MgO 5.00-8.00%, ZnO 8.00-14.00%, Na2O 7.20-14.00%, B2O3 3.00-8.00%, K2O 0-2.00%, and Y2O3 0-1.00%.

[0016] Among them, the lithium-free transparent spinel microcrystalline glass contains little Li2O, and the content of Li2O is less than 0.01% in mol%.

[0017] Preferably, the lithium-free transparent spinel glass-ceramics has a composition containing oxides in the following proportions in mol%: SiO2 38.00-44.00%, Al2O3 25.50-30.00%, ZrO2 3.00-4.00%, MgO 5.00-7.00%, ZnO 8.00-12.00%, Na2O 7.20-13.00%, B2O3 3.00-7.00%, K2O 0-2.00%, and Y2O3 0-1.00%.

[0018] Preferably, the lithium-free transparent spinel glass-ceramics has a composition containing oxides in the following proportions in mol%: SiO2 38.00-44.00%, Al2O3 25.50-30.00%, ZrO2 3.00-4.00%, MgO 5.00-7.00%, ZnO 8.00-12.00%, Na2O 7.20-13.00%, B2O3 3.00-7.00%, K2O 0-2.00%, and Y2O3 0-1.00%.

[0019] The value of A is calculated based on the following formula (1), and A is less than or equal to 0.18, preferably A is 0.05-0.15,

[0020] (1) A = 0.65 x Al2O3 + 3.5 x ZrO2 - 0.8 x Na2O - 2.5 x B2O3 + 0.5 x K2O - 0.5 x Y2O3 3；

[0021] and / or,

[0022] The value of B is calculated based on the following formula (2), and B is less than or equal to 0.80, preferably B is 0.60-0.78,

[0023] (2) B = 3.8 x Na2O + B2O3 + 4.5 x MgO + 6.0 x ZnO - 0.4 x Al2O3 - SiO2.

[0024] Preferably, the molar percentage of Na2O is 7.20-12.00%;

[0025] and / or, the molar percentage of Al2O3 is 25.50-28.00%;

[0026] and / or, the molar percentage of MgO is 5.00-6.50%;

[0027] and / or, the molar percentage of ZnO is 8.00-10.50%;

[0028] and / or, the molar percentage of B2O3 is 3.00-6.50%.

[0029] Preferably, in the lithium-free transparent spinel glass-ceramics, the molar percentages of Al2O3, MgO, and ZnO satisfy the following relationship: Al2O3 - MgO - ZnO = 8.00-15.00%.

[0030] Preferably, the composition of the lithium-free transparent spinel glass-ceramics satisfies:

[0031] The value of X is calculated based on the following formula (3), and the value of X is 30.00-50.00%, preferably the value of X is 34.00-46.00%,

[0032] (3) X = 2.1 x (Al2O3-MgO-ZnO) / (SiO2+Al2O3-MgO-ZnO+Na2O+K2O+B2O3);

[0033] and / or,

[0034] The value of Y is calculated based on the following formula (4), and the value of Y is 60.00-80.00%, preferably the value of Y is 60.00-75.00%,

[0035] (4) Y = (2.7 x Na2O + 1.8 x (Al2O3-MgO-ZnO)) / (SiO2+Al2O3-MgO-ZnO+Na2O+K2O+B2O3).

[0036] Preferably, the spinel crystal is (Zn,Mg)Al2O4; and / or, the lithium-free transparent spinel glass-ceramics further comprises a sub-crystal phase of tetragonal zirconia.

[0037] Preferably, the crystallinity of the lithium-free transparent spinel glass-ceramics is ≥20.00wt%, preferably the crystallinity is 20.00-50.00wt%, further preferably the crystallinity is 30.00-50.00wt%, more preferably the crystallinity is 35.00-45.00wt%.

[0038] Preferably, the average grain size in the lithium-free transparent spinel glass-ceramics is ≤15.0nm, preferably 1.0-15.0nm, further preferably 1.0-10.0nm, more preferably 4.5-8.0nm.

[0039] Preferably, the transmittance of the lithium-free transparent spinel glass-ceramics is greater than or equal to 85% for light of 550nm wavelength at a thickness of 0.7mm, preferably the transmittance is greater than or equal to 89%.

[0040] Preferably, the Young's modulus of the lithium-free transparent spinel glass-ceramics is ≥100GPa, preferably the Young's modulus is ≥110GPa, more preferably 114GPa≤Young's modulus≤140GPa.

[0041] Preferably, the optical b value of the lithium-free transparent spinel glass-ceramics is 0.20-1.50, preferably 0.50-1.20 at a thickness of 0.7 mm.

[0042] Preferably, the lithium-free transparent spinel glass-ceramics contains substantially no BaO, i.e. BaO is less than 0.01% in terms of mol%.

[0043] Preferably, the lithium-free transparent spinel glass-ceramics contains substantially no TiO2, i.e. TiO2 is less than 0.01% in terms of mol%.

[0044] In another aspect, the present application also provides a method for preparing the lithium-free transparent spinel glass-ceramics, comprising the following steps: subjecting a base glass to heat treatment to form the lithium-free transparent spinel glass-ceramics.

[0045] The lithium-free transparent spinel glass-ceramics contains spinel crystals, and the spinel crystals are the main crystal phase of the lithium-free transparent spinel glass-ceramics.

[0046] The lithium-free transparent spinel glass-ceramics contains oxides in the following proportions in terms of mol%: SiO238.00-48.00%, Al2O325.50-30.00%, ZrO23.00-5.00%, MgO 5.00-8.00%, ZnO 8.00-14.00%, Na2O 7.20-14.00%, B2O3 3.00-8.00%, K2O 0-2.00%, and Y2O3 0-1.00%.

[0047] Preferably, the lithium-free transparent spinel glass-ceramics contains substantially no Li2O, i.e. Li2O is less than 0.01% in terms of mol%.

[0048] Preferably, in the above method, the heat treatment comprises nucleation treatment and / or crystallization treatment; wherein: the temperature of the nucleation treatment is 600-850°C, preferably 600-750°C, preferably, the nucleation treatment time is 0-72h, preferably 0-24h.

[0049] Preferably, the temperature of the crystallization treatment is 700-1000°C, preferably 700-800°C, preferably, the crystallization treatment time is 0.1-72h, preferably 0.1-24h; and / or,

[0050] When the heat treatment is performed, the temperature increase rate is controlled to be 5-15K / min.

[0051] Preferably, in the above method, the composition of the lithium-free transparent spinel glass-ceramics satisfies the following conditions in terms of the content of each oxide in the lithium-free transparent spinel glass composition:

[0052] A = 0.65 * Al203 + 3.5 * Zr02 - 0.8 * Na20 - 2.5 * B203, wherein A < 0.18, preferably the value of A is 0.05-0.15;

[0053] and / or, B = 3.8 * Na20 + B203 + 4.5 * MgO + 6.0 * ZnO - 0.4 * Al203 - Si02, wherein B < 0.80, preferably the value of B is 0.60-0.78;

[0054] and / or, X = 2.1 * (Al203 - MgO - ZnO) / (Si02 + Al203 - MgO - ZnO + Na20 + K20 + B203), wherein X = 30.00-50.00%, preferably X = 34.00-46.00%;

[0055] and / or, Y = (2.7 * Na20 + 1.8 * (Al203 - MgO - ZnO)) / (Si02 + Al203 - MgO - ZnO + Na20 + K20 + B203), wherein Y = 60.00-80.00%, preferably Y = 60.00-75.00%;

[0056] and / or, in the lithium-free transparent spinel glass-ceramics, Al203 3、 The molar percentage of each component of MgO and ZnO satisfies the following relationship: Al203 - MgO - ZnO = 8.00-15.00%.

[0057] Preferably, in the above preparation method, the lithium-free transparent spinel glass-ceramics contains substantially no BaO, and the content of BaO is less than 0.01% in terms of mol%; and / or,

[0058] The lithium-free transparent spinel glass-ceramics contains substantially no Ti02, and the content of Ti02 is less than 0.01% in terms of mol%.

[0059] In another aspect, the present application also provides a base glass for preparing the above lithium-free transparent spinel glass-ceramics, which contains the following oxides in the following proportions in terms of mol%: Si02 38.00-48.00%, Al203 25.50-30.00%, Zr02 3.00-5.00%, MgO 5.00-8.00%, ZnO 8.00-14.00%, Na20 7.20-14.00%, B203 3.00-8.00%, K20 0-2.00%, and Y203 0-1.00%; wherein the base glass contains substantially no Li20, and the content of Li20 is less than 0.01% in terms of mol%.

[0060] Preferably, the composition of the substrate glass satisfies:

[0061] A = 0.65 x Al2O3 + 3.5 x ZrO2 - 0.8 x Na2O - 2.5 x B2O3, wherein A ≤ 0.18, preferably the value of A is 0.05-0.15;

[0062] and / or, B = 3.8 x Na2O + B2O3 + 4.5 x MgO + 6.0 x ZnO - 0.4 x Al2O3 - SiO2, wherein B ≤ 0.80, preferably the value of B is 0.60-0.78;

[0063] and / or, X = 2.1 x (Al2O3 - MgO - ZnO) / (SiO2 + Al2O3 - MgO - ZnO + Na2O + K2O + B2O3), wherein X = 30.00-50.00%, preferably X = 34.00-46.00%;

[0064] and / or, Y = (2.7 x Na2O + 1.8 x (Al2O3 - MgO - ZnO)) / (SiO2 + Al2O3 - MgO - ZnO + Na2O + K2O + B2O3), wherein Y = 60.00-80.00%, preferably Y = 60.00-75.00%;

[0065] and / or, the molar percentage of each of Al2O3, MgO and ZnO in the substrate glass satisfies the following relationship: Al2O3 - MgO - ZnO = 8.00-15.00%.

[0066] Preferably, the substrate glass contains substantially no BaO, i.e. BaO is less than 0.01% in mol%; and / or,

[0067] Preferably, the substrate glass contains substantially no TiO2, i.e. TiO2 is less than 0.01% in mol%.

[0068] In another aspect, the present application also provides a chemically strengthened glass, which is obtained by chemically strengthening the above lithium-free transparent spinel glass-ceramics, the lithium-free transparent spinel glass-ceramics prepared by the above method or the above substrate glass.

[0069] In another aspect, the present application also provides the use of the lithium-free transparent spinel glass-ceramics or the lithium-free transparent spinel glass prepared by the above preparation method or the substrate glass or the chemically strengthened glass in a mobile phone display screen, a tablet computer display screen, a handheld game console, an electronic terminal, a portable digital device, a vehicle-mounted central control screen, an electronic whiteboard glass, a smart home touch screen, a vehicle windshield, an aircraft windshield or a navigation device.

[0070] Advantages of the present application:

[0071] 1. The lithium-free transparent spinel glass provided by the present application has good economic benefits. On the one hand, the glass-ceramics of the present application does not need to use expensive lithium, and can also obtain excellent surface stress characteristics and deep stress characteristics through chemical strengthening, and obtain excellent drop impact resistance. On the other hand, the optimized glass formula of the present application corresponds to a substrate glass with low melting difficulty and is not prone to melting defects. And under the condition that the heat treatment temperature is not more than 800℃, a transparent glass-ceramics with main crystal phase of zinc magnesium spinel solid solution and excellent optical performance and high intrinsic strength can be obtained. The production difficulty of the transparent spinel glass-ceramics is greatly reduced, the production possibility is higher, and it meets the development needs of energy saving and carbon reduction in the industry.

[0072] 2. The lithium-free transparent spinel glass provided by the present application has high intrinsic strength, and can obtain a strengthened glass-ceramics with excellent drop impact resistance through chemical strengthening, which can meet the use requirements of electronic device cover glass. By adjusting the amount and the amount relationship of each oxide in the formula, and using the synergistic effect of specific content of each oxide component, the glass-ceramics has a specific network structure while obtaining the target main crystal phase (Zn, Mg) Al2O4 with the required content. By uniformly distributing a large amount of main crystal phase (Zn, Mg) Al2O4 with high Young's modulus and shear modulus in the specific glass network structure, the intrinsic strength of the glass-ceramics is greatly improved. On this basis, by chemically strengthening the glass-ceramics, a strengthened glass-ceramics with excellent surface stress characteristics and excellent deep stress characteristics can be obtained. The high intrinsic strength combined with excellent surface stress characteristics and deep stress characteristics endows the strengthened glass-ceramics with excellent mechanical properties, so that the strengthened glass-ceramics has excellent drop impact resistance. BRIEF DESCRIPTION OF DRAWINGS

[0073] Figure 1 The melting result diagram of the substrate glass of Example 1;

[0074] Figure 2 The melting result diagram of the substrate glass of Example 3;

[0075] Figure 3A melting result graph of the base glass of Example 1;

[0076] Figure 4 An appearance graph of the lithium-free transparent spinel glass-ceramics of Example 4;

[0077] Figure 5 An appearance graph of the lithium-free transparent spinel glass-ceramics of Example 5;

[0078] Figure 6 A thermogravimetric analysis curve of the base glass of Example 1;

[0079] Figure 7 An XRD diffraction graph of the lithium-free transparent spinel glass-ceramics of Example 1;

[0080] Figure 8 A transmittance curve of the lithium-free transparent spinel glass-ceramics of Example 5 under different wavelengths;

[0081] Figure 9 A melting result graph of the base glass of Comparative Example 1;

[0082] Figure 10 A melting result graph of the base glass of Comparative Example 2;

[0083] Figure 11 A melting result graph of the base glass of Comparative Example 3;

[0084] Figure 12 A melting result graph of the base glass of Comparative Example 6;

[0085] Figure 13 An appearance graph of the glass-ceramics of Comparative Example 19. DETAILED DESCRIPTION

[0086] The present inventors have repeatedly tested and researched, and as a result, have found that, by specifying the content and content ratio of specific components constituting the glass-ceramics to a specific ratio, the lithium-free transparent spinel glass-ceramics of the present application, which have a melting effect, a stress effect, an optical effect, and mechanical properties, can be obtained.

[0087] In the present application, unless otherwise indicated in specific cases, the numerical ranges listed herein include the upper and lower limit values, "above" and "below" include the end point values, and all integers and fractions within the range, and are not limited to the specific values listed in the defined range. As used herein, "and / or" is inclusive, for example, "A; and / or B" means only A, or only B, or both A and B.

[0088] As used herein, the language "substantially free of" or "free of" when used in reference to a constituent component of a composition, batch, melt, or article means that the constituent component is not intentionally added or dosed into the composition, batch, melt, or article but can be present in small amounts of less than about 0.01% (by mole of oxide) as a contaminant and / or due to the degree of inherent uncertainty attributed to any measurement or analytical technique.

[0089] In the present invention, the glass-ceramics, also known as glass ceramics, are a kind of solid composite materials containing both glass phase and crystal phase (microcrystalline phase, crystalline phase, crystal phase) prepared by targeted and controlled heat treatment of the base glass. It should be understood that the crystal phase and the crystal grain both refer to the crystals precipitated in the glass-ceramics, and the description methods are different. The crystal phase is the crystalline microstructure, which is determined by the conformation of the high molecular chain in the crystal and its arrangement.

[0090] In the present invention, the base glass refers to the glass that has not been subjected to nucleation treatment, crystallization treatment, and strengthening treatment.

[0091] In the present invention, the chemically strengthened glass refers to the solid composite material obtained after the base glass or the glass-ceramics is subjected to chemical strengthening treatment. The glass-ceramics subjected to chemical strengthening treatment obtains strengthened glass-ceramics.

[0092] It should be understood that when high-temperature chemical strengthening treatment is performed, the alkali metal ions with large ionic radius (such as potassium ions, sodium ions) in the salt bath / melt salt will replace the alkali metal ions with small ionic radius (such as sodium ions, lithium ions) in the base glass or the glass-ceramics, thereby generating an exchange ion volume difference and generating a compressive stress on the surface of the glass.

[0093] In the present invention, the nucleation treatment refers to the growth of small crystal nuclei from the nucleation substances in the glass through heat treatment; and the crystallization treatment refers to the growth of certain crystals on the basis of the crystal nuclei through heat treatment.

[0094] In the present invention, the nucleation temperature refers to the temperature at which the crystal nuclei are formed.

[0095] In the present invention, the crystallization temperature refers to the temperature at which the growth rate of the target crystal is controllable.

[0096] In the present invention, the optical b value represents the yellow-blue value of the material. In the present invention, the optical b value is the transmitted light b value, and the positive optical b value indicates that the material is blue.

[0097] The transmittance refers to the ratio of the radiation energy projected and transmitted through the object to the total radiation energy projected onto the object in the process of the incident light flux from the illuminated surface or the medium incident surface to the other surface. It should be understood that when the light of a certain wavelength is incident on the surface of the glass, the light will be reflected, absorbed, and transmitted, and the ratio of the intensity of the transmitted part to the intensity of the incident light is the transmittance.

[0098] In the present application, the transmittance of the glass-ceramics at 550 nm wavelength refers to the average value of the transmittance of multiple glass samples of the same batch at 550 nm wavelength, and at least 5 samples of each batch of glass-ceramics are tested. In the present application, the Konica Minolta Spectrophotometer CM-3600A is used to test the transmittance of each glass sample at 550 nm wavelength.

[0099] In the present application, fogging refers to the semi-transmission state between transparency and opacification due to large crystals or phase separation in the glass-ceramics / glass-ceramics.

[0100] In the present application, opacification refers to the complete loss of transparency of the glass due to large crystals or phase separation in the glass-ceramics / glass-ceramics, and the back of the glass cannot be seen.

[0101] In the present application, surface CS refers to surface compressive stress or surface compressive stress. After chemical strengthening of the glass-ceramics / glass-ceramics, the small radius alkali metal ions on the surface are replaced by large radius alkali metal ions. Due to the crowding effect of large radius alkali metal ions, the surface of the glass produces compressive stress, which is called surface compressive stress.

[0102] In the present application, |CT_CV| refers to the absolute value of the maximum tensile stress in the tensile stress layer, specifically the absolute value of the maximum value of all tensile stresses in the tensile stress layer.

[0103] In the present application, CS_50 refers to the compressive stress value at a depth of 50 μm from the surface of the glass.

[0104] In the present application, DOL_0 refers to the depth of the compressive stress layer, also known as the depth of the compressive stress layer, which refers to the distance from any surface of the glass to the position close to the surface where the compressive stress is zero.

[0105] In the present application, |CT_AV| refers to the absolute value of the average tensile stress in the tensile stress layer, specifically the absolute value of the average value of all tensile stresses in the tensile stress layer.

[0106] In the present application, CT_LD refers to tensile stress line density, which is the ratio of the absolute value of the sum of the tensile stress of the strengthened glass-ceramic measured by SLP-2000 stress meter to the thickness of the glass. The glass-ceramic is placed in a salt bath to perform ion exchange to form a compressive stress layer (i.e. a strengthened layer). During the ion exchange process, a tensile stress layer is formed inside the glass. The tensile stress layer has an upper boundary at a certain interval from the upper surface of the strengthened glass-ceramic and a lower boundary at a certain interval from the lower surface of the strengthened glass. The tensile stress at a point on a line segment in the tensile stress layer, which is perpendicular to the upper boundary and the lower boundary at the same time and whose upper and lower endpoints fall on the upper boundary and the lower boundary respectively, is taken as the Y-axis, and the distance of the corresponding point from the upper boundary is taken as the X-axis. The curve drawn by the above-mentioned Y and X is called the tensile stress curve. The ratio of the definite integral of the tensile stress curve to the thickness of the strengthened glass-ceramic is called the tensile stress line density.

[0107] In the present application, SOC refers to the photoelastic coefficient. Photoelasticity mainly refers to the anisotropy and birefringence phenomenon of transparent materials after being stressed. Through photoelastic coefficient and birefringence measurement, the value of the internal residual stress (MPa) of the material can be obtained.

[0108] In the present application, the surface K2O concentration is equal to the mass of K2O / the total mass of oxides, wherein the total mass of oxides includes SiO2, Al2O3, P2O5, ZrO2, Na2O, K2O and other oxides that can be accurately tested by XRF, and does not include the content of Li2O, B2O3 and other oxides that cannot be accurately tested by XRF. During XRF testing, no standard test is used, and the concentration of elements or oxides with atomic number 6 and below in the glass is not tested. That is, the total mass of oxides does not include the mass of elements or oxides with atomic number 6 and below in the glass when calculating the K2O concentration obtained by XRF testing in the present application.

[0109] In the present application, Vickers hardness refers to a standard for indicating the hardness of a material proposed by Robert L. Smith and George E. Sandland of Vicke rs Ltd in 1921.

[0110] In the present application, fracture toughness refers to the resistance value displayed by the material when the sample or component has a crack or crack-like defect and occurs as the starting point of rapid fracture with increasing load, i.e. the so-called unstable fracture.

[0111] In a specific embodiment of the present application, the lithium-free transparent spinel glass-ceramic is prepared by heat treatment of a base glass. The present application provides a lithium-free transparent spinel glass-ceramic, which contains spinel crystals and the spinel crystals are the main crystal phase of the lithium-free transparent spinel glass-ceramic.

[0112] The lithium-free transparent spinel glass-ceramics has the following composition in terms of mol%: SiO2 38.00-48.00%, Al2O3 25.50-30.00%, ZrO2 3.00-5.00%, MgO 5.00-8.00%, ZnO 8.00-14.00%, Na2O 7.20-14.00%, B2O3 3.00-8.00%, K2O 0-2.00%, and Y2O3 0-1.00%; wherein the lithium-free transparent spinel glass-ceramics is substantially free of Li2O, and the content of Li2O is less than 0.01% in terms of mol%.

[0113] Hereinafter, the ranges of the components of the lithium-free transparent spinel glass-ceramics of the present application are described.

[0114] The inventors have found that in the formulation system of the present application, the appropriate increase of the content of Na2O helps to obtain higher stress characteristics, including high surface stress characteristics and high deep stress characteristics, by chemical strengthening of the glass-ceramics, while reducing the melting temperature and the temperature of crystal precipitation. Too low content of Na2O is not conducive to obtaining high stress characteristics by strengthening of the glass-ceramics, and also leads to an increase in the heat treatment temperature, increasing the difficulty of mass production of the glass-ceramics, and also easily causes direct phase separation or precipitation of impurities affecting the optical properties of the glass-ceramics during the heat treatment process, resulting in semi-transparent or even non-transparent glass-ceramics. Excessive addition of Na2O also affects the network structure of the glass due to the provision of a large amount of free oxygen, and also easily leads to ceramming of the base glass during annealing or precipitation of impurities affecting the optical properties of the glass-ceramics during heat treatment of the base glass to prepare the glass-ceramics, resulting in a decrease in the transmittance of the glass-ceramics. Therefore, in the present application, the content of Na2O is 7.20-14.00% in terms of mol%, preferably 7.20-13.00%, and more preferably 7.20-12.00%.

[0115] In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise Na2O in a molar percentage of 7.20-13.50%, 7.20-13.00%, 7.20-12.50%, 7.20-12.00%, 7.20-11.50%, 7.20-11.00%, 7.20-10.50%, 7.20-10.00%, 7.20-9.50%, 7.20-9.00%, 7.70-14.00%, 8.20-14.00%, 8.70-14.00%, 9.20-14.00%, 9.70-14.00%, 10.20-14.00%, 10.70-14.00%, or 11.50-14.00%. In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise Na2O in a molar percentage of 7.20%, 7.70%, 8.20%, 8.70%, 9.20%, 9.70%, 10.20%, 10.70%, 11.20%, 11.50%, 12.20%, 12.70%, 13.20%, 13.70%, or 14.00%, or within a range bounded by any two of the foregoing as endpoints. It should be understood that any of the foregoing ranges can be combined with any other range to arrive at a glass having the desired properties of the present application.

[0116] The inventors have found that SiO2 is a network former oxide and is an indispensable component of the glass network structure. Increasing the content of SiO2 appropriately can increase the stability and mechanical strength of the glass, but excessive SiO2 can increase the viscosity of the base glass, making it difficult to melt the glass and thus reducing the formability of the base glass. Therefore, in the present application, the content of SiO2 is 38.00-48.00% in terms of mol%, preferably 38.00-44.00%.

[0117] In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise SiO2 in a molar percentage of 38.00-48.00%, 38.50-48.00%, 39.00-48.00%, 40.00-48.00%, 42.00-48.00%, 44.00-48.00%, 38.00-46.00%, 38.00-44.00%, 38.00-42.00%, 38.00-40.00%, 38.00-39.00%, 38.00-48.00%, 38.00-46.00%, 38.00-44.00%, 38.00-42.00%, 38.00-40.00%, 38.00-39.00%, 38.50-46.00%, 39.00-46.00%, 40.00-46.00%, 42.00-46.00%, 44.00-46.00%, 38.50-44.00%, 39.00-44.00%, 40.00-44.00%, 42.00-44.00%, or 44.00-48.00%.

[0118] 38.00% to 42.00% or 38.00% to 40.00% of Si02. In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise 38.00%, 38.50%, 39.00%, 40.00%, 41.00%, 42.00%, 43.00%, 44.00%, 45.00%, 46.00%, 47.00%, or 48.00% of Si02by mole, or a value of Si02within a range defined by any two of the above specifically named values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range to obtain a glass having the desired properties of the present application.

[0119] The inventors have found that in the formulation system of the present application, the appropriate addition of Al203not only promotes the precipitation of the main crystal phase spinel and inhibits the precipitation of other impurity phases such as quartz ss that affect the optical properties of the microcrystalline glass of the system, but also increases the ion exchange rate during the strengthening process and promotes the ion exchange process. However, too much Al203will cause the melting difficulty of the base glass to increase sharply, and at the same time, accelerate the crystallization rate of the base glass, so that the base glass is prone to crystallization and lose transparency during the normal cooling process during preparation. Therefore, in the present application, the content of Al203is 25.50-30.00% by mole, preferably 25.50-28.00%.

[0120] In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise 25.50-29.50%, 25.50-29.00%, 25.50-28.50%, 25.50-28.00%, 25.50-27.50%, 25.50-27.00%, 25.50-26.50%, 26.00-30.00%, 26.50-30.00%, 27.00-30.00%, 27.50-30.00%, 28.00-30.00%, 28.50-30.00%, or 29.00-30.00% of Al203by mole. In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise 25.50%, 26.00%, 26.50%, 27.00%, 27.50%, 28.00%, 28.50%, 29.00%, 29.50%, or 30.00% of Al203by mole, or a value of Al203within a range defined by any two of the above specifically named values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range to obtain a glass having the desired properties of the present application.

[0121] The inventors have found that in the formulation system of the present application, MgO and ZnO as the main components of spinel, when added in appropriate amounts, can promote the precipitation of spinel, and also to a certain extent, reduce the difficulty of melting the base glass, but excessive MgO and ZnO often leads to the spinel grains easily grow, it is difficult to get high transparency of the glass-ceramics. That is, the content of MgO and ZnO largely determines whether the glass-ceramics sample can be transparent and whether the optical performance is excellent. Therefore, in the present application, the content of MgO is 5.00% to 8.00% by mol, preferably 5.00 to 7.00%, more preferably 5.00 to 6.50%; the content of ZnO is 8.00% to 14.00% by mol, preferably 8.00 to 12.00%, more preferably 8.00 to 10.50%.

[0122] In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise MgO in a molar percentage of 5.50% to 8.00%, 6.00% to 8.00%, 6.50% to 8.00%, 7.00 to 8.00%, 5.00% to 7.50%, 5.00% to 7.00%, 5.00% to 6.50%, or 5.00% to 6.00%. In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise MgO in a molar percentage of 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50, or 8.00%, or within a range defined by any two of the above specific values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the desired properties of the glass of the present application are obtained.

[0123] In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise ZnO in a molar percentage of 8.50-14.00%, 9.00-14.00%, 9.50-14.00%, 10.00-14.00%, 10.50-14.00%, 11.00-14.00%, 11.50-14.00%, 12.00-14.00%, 8.00-13.50, 8.00-13.00, 8.00-12.50, 8.00-12.00, 8.00-11.50, 8.00-11.00, 8.00-10.50, or 8.00-10.00%. In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise ZnO in a molar percentage of 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 10.50%, 11.00%, 11.50%, 12.00%, 12.50%, 13.00%, 13.50%, or 14.00%, or ZnO within a range between any two of the above specifically named values as endpoints. It is understood that in specific embodiments, any of the above ranges can be combined with any other range to obtain a glass having the desired properties of the present application.

[0124] The inventors have found that in the formulation system of the present application, Zr02 acts as an effective nucleating agent. During the heat treatment of the base glass to produce the glass-ceramics, Zr02 is first precipitated from the glass in the form of crystals, which become the nuclei for the subsequent growth of the main crystal, spinel. Within a certain range of glass composition, the content of Zr02 will affect the formation of the base glass, the crystal shape, crystal type and crystal size of the glass-ceramics after heat treatment of the base glass. Therefore, in the present application, the content of Zr02 is 3.00-5.00% in mol%, preferably 3.00-4.00%.

[0125] In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise Zr02 in a molar percentage of 3.50-5.00%, 4.00-5.00%, 4.50-5.00%, 3.00-4.50%, 3.00-4.00%, or 3.00-3.50%. In some embodiments, the lithium-free transparent spinel glass-ceramics described above can comprise Zr02 in a molar percentage of 3.00%, 3.50%, 4.00%, 4.50%, or 5.00%, or Zr02 within a range between any two of the above specifically named values as endpoints. It is understood that in specific embodiments, any of the above ranges can be combined with any other range to obtain a glass having the desired properties of the present application.

[0126] The inventor has found that in the formula system of the present application, the appropriate amount of B2O3 can not only greatly reduce the melting difficulty of the base glass, but also is beneficial to promote the precipitation of the main crystal phase spinel. When the amount of B2O3 is too low, the base glass prepared by melting may have defects. However, when the amount of B2O3 is too high, the base glass may appear cloudy during heat treatment for preparing the microcrystalline glass, and other impurity crystal phases may be precipitated, which seriously affects the transparency of the microcrystalline glass. Therefore, in the present application, the content of B2O3 is 3.00-8.00% by mol, preferably 3.00-7.00% by mol, and more preferably 3.00-6.50% by mol.

[0127] In some embodiments, the lithium-free transparent spinel microcrystalline glass described above can contain B2O3 in a molar percentage of 3.50-8.00%, 4.00-8.00%, 4.50-8.00%, 5.00-8.00%, 5.50-8.00, 6.00-8.00%, 6.50-8.00%, 7.00-8.00%, 3.00-7.50%, 3.00-7.00%, 3.00-6.50%, 3.00-6.00%, 3.00-5.50%, 3.00-5.00%, 3.00-4.50%, or 3.00-4.00%. In some embodiments, the lithium-free transparent spinel microcrystalline glass described above can contain B2O3 in a molar percentage of 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, or 8.00%, or B2O3 within a numerical range formed by any two of the above specific numerical values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the glass has the desired properties of the present application.

[0128] In order to ensure the melting effect and optical properties of the glass, in the present application, Na2O+B2O3 is 10.20-20.00%, preferably 10.20-18.00%. The coordination of Na2O+B2O3 with the overall composition can not only solve the melting problem, but also enable the base glass to have better optical properties. In addition, the increase of Na2O and B2O3 can solve the melting problem caused by the increase of Al2O3 content.

[0129] The inventor has found that in the formula system of the present application, although BaO can improve the melting effect of the base glass and to some extent inhibit the growth of crystal grains, thereby improving the optical properties of the microcrystalline glass, it has a strong inhibitory effect on Na-K exchange, which is not conducive to the chemical strengthening of the microcrystalline glass. Therefore, in the present application, BaO is preferably not added, and the content of BaO is less than 0.01% by mol.

[0130] The inventors have found that, in the formulation system of the present application, the addition of TiO2 as a nucleating agent causes the substrate glass to exhibit an undesirable color. In order to obtain the desired transparent colorless glass-ceramics, the present application preferably does not contain TiO2, and the content of TiO2 is less than 0.01% in terms of mol%.

[0131] The inventors have found that, in the formulation system of the present application, K2O is an optional component that helps to improve the low-temperature melting and forming properties of the glass, and since K2O has a larger ionic radius than Na2O and K2O has a smaller ionic radius than Li2O, + Na2O and K2O have a larger ionic radius than Li2O, and K2O has a smaller ionic radius than Na2O. + The appropriate addition of K2O can reduce the crystallization tendency of the glass, increase the transparency and luster of the glass. However, if K2O is contained in excess, not only is it easy to cause a decrease in the chemical stability and hardness of the glass, but it also easily makes the crystallization ability of the glass stronger, and the glass is easy to lose transparency, and the crystallized glass is easy to break. Therefore, in the present application, the content of K2O is 0-2.00% in terms of mol%.

[0132] The inventors have found that, in the formulation system of the present application, Y2O3 is an optional component that improves the hardness and chemical stability of the glass-ceramics and inhibits the crystallization of the glass during forming, and the appropriate amount of Y2O3 can improve the density of the glass phase, thereby improving the overall strength of the glass-ceramics, and Y2O3 can form a eutectic body with ZrO2, thereby reducing the non-uniformity caused by the precipitation of ZrO2 during melting in the furnace. However, if the content of Y2O3 is too high, it will affect the precipitation of spinel crystals and reduce the chemical strengthening performance of the glass and glass-ceramics. Therefore, in the present application, the content of Y2O3 is 0-1.00% in terms of mol%.

[0133] In some preferred embodiments of the present application, the composition of the lithium-free transparent spinel glass-ceramics of the present application satisfies:

[0134] The value of A is calculated based on the following formula (1), wherein the value of A is less than or equal to 0.18, and preferably the value of A is 0.05-0.15,

[0135] (1) A = 0.65 x Al2O3 + 3.5 x ZrO2 - 0.8 x Na2O - 2.5 x B2O3;

[0136] and / or,

[0137] The value of B is calculated based on the following formula (2), wherein the value of B is less than or equal to 0.80, and preferably the value of B is 0.60-0.78,

[0138] (2) B = 3.8 x Na2O + B2O3 + 4.5 x MgO + 6.0 x ZnO - 0.4 x Al2O3 - SiO2.

[0139] The present inventors have found through experimental research that the A value calculated based on the above formula is closely related to the melting effect of the base glass used to prepare the lithium-free transparent spinel microcrystalline glass. By controlling the A value within a suitable range through the specific proportional relationship of the oxide components described above, it can be ensured that a transparent base glass meeting the requirements is obtained, and that each oxide component in the base glass is fully melted without un-melted components.

[0140] The present inventors have also found through experiments that the B value calculated based on the above formula is also closely related to the melting effect of the base glass used to prepare the lithium-free transparent spinel microcrystalline glass. By controlling the B value within a suitable range through the specific proportional relationship of the oxide components described above, it can be ensured that the base glass will not be ceramicized during the preparation process, especially during the annealing process, and thus a transparent base glass meeting the requirements can be obtained.

[0141] In some embodiments, the A value can be 0.07-0.15, 0.09-0.15, 0.11-0.15, 0.13-0.15, 0.05-0.13, 0.05-0.11, 0.05-0.09, or 0.05-0.07. In some embodiments, the lithium-free transparent spinel microcrystalline glass described above can include an A value of 0.05, 0.07, 0.09, 0.11, 0.13, 0.15, 0.17, or 0.18, or an A value within a numerical range formed by any two of the above specific numerical values as endpoints. 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 with the required properties of the present application can be obtained.

[0142] In some embodiments, the B value can be 0.60-0.76, 0.60-0.74, 0.60-0.72, 0.60-0.70, 0.60-0.68, 0.60-0.64, 0.62-0.78, 0.64-0.78, 0.66-0.78, 0.68-0.78, 0.70-0.78, 0.72-0.78, or 0.74-0.78. In some embodiments, the lithium-free transparent spinel microcrystalline glass described above can include a B value of 0.60, 0.62, 0.64, 0.66, 0.68, 0.70, 0.72, 0.74, 0.76, 0.78, or 0.80, or a B value within a numerical range formed by any two of the above specific numerical values as endpoints. 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 with the required properties of the present application can be obtained.

[0143] In some preferred embodiments of the present application, the above lithium-free transparent spinel glass-ceramics, the molar percentage of each component of Al2O3, MgO, ZnO satisfies the following relationship: the molar percentage of Al2O3 minus the molar percentage of MgO and the molar percentage of ZnO is 8.00-15.00%, i.e. the value of Al2O3-MgO-ZnO is 8.00-15.00%. Al2O3, MgO and ZnO are all main components of the main crystal phase spinel crystals of the present application. By adjusting the content relationship of Al2O3, MgO and ZnO, on the one hand, it can ensure that a glass-ceramics with high crystal content / crystallinity is obtained, which is conducive to improving the intrinsic strength of the glass-ceramics, on the other hand, by allowing an appropriate amount of Al2O3 to remain in the residual glass phase to form [AlO4] tetrahedral structure, it is also more conducive to realizing the chemical strengthening of the glass-ceramics, and it is conducive to making the glass-ceramics strengthening obtain high stress characteristics, because the volume of [AlO4] tetrahedron is larger than that of [SiO4], the presence of appropriate amount of [AlO4] is more conducive to widening the ion exchange channel and promoting the diffusion of alkali metal ions.

[0144] In some embodiments, the value of Al2O3-MgO-ZnO can be 8.50-15.00%, 9.00-15.00%, 9.50-15.00%, 10.00-15.00%, 10.50-15%, 11.00-15.00%, 11.50-15.00%, 12.00-15.00%, 12.50-15%, 13.00-15.00%, 13.50-15.00%, 14.00-15.00%, 8.00-14.50%, 8.00-14.00%, 8.00-13.50%, 8.00-13.00%, 8.00-12.50%, 8.00-12.00%, 8.00-11.50%, 8.00-11.00%, 8.00-10.50%, 8.00-10.00%, 8.00-9.50% or 8.00-9.00%. In some embodiments, the above lithium-free transparent spinel glass-ceramics can contain Al2O3-MgO-ZnO with a value of 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% or 15.00%, or the value of Al2O3-MgO-ZnO within the numerical range formed by any two specific numerical values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the desired performance of the glass of the present application is obtained.

[0145] In still another preferred embodiment of the present application, the composition of the lithium-free transparent spinel glass-ceramics of the present application satisfies:

[0146] The value of X is calculated based on the following formula (3), and the value of X is 30.00-50.00%, preferably the value of X is 34.00-46.00%,

[0147] (3) X = 2.1 x (Al2O3-MgO-ZnO) / (SiO2+Al2O3-MgO-ZnO+Na2O+K2O+B2O3);

[0148] and / or,

[0149] The value of Y is calculated based on the following formula (4), and the value of Y is 60.00-80.00%, preferably the value of Y is 60.00-75.00%,

[0150] (4) Y = (2.7 x Na2O+1.8 x (Al2O3-MgO-ZnO)) / (SiO2+Al2O3-MgO-ZnO+Na2O

[0151] +K2O+B2O3).

[0152] The present inventors have found through experimental research that the value of X calculated based on the above formula is closely related to the deep stress characteristics that can be obtained after chemical strengthening of the lithium-free transparent spinel glass-ceramics, and by controlling the value of X within a suitable range through the specific proportional relationship of the above oxide components, excellent deep stress characteristics can be obtained after chemical strengthening of the glass-ceramics of the present application, such as high CS_50, DOL_O, |CT_AV|, |CT_CV|, CT_LD values.

[0153] The present inventors have also found through experimental research that the value of Y calculated based on the above formula is closely related to the surface stress characteristics that can be obtained after chemical strengthening of the lithium-free transparent spinel glass-ceramics, and by controlling the value of Y within a suitable range through the specific proportional relationship of the above oxide components, excellent surface stress characteristics can be obtained after chemical strengthening of the glass-ceramics of the present application, such as high surface K2O concentration and high surface CS value.

[0154] In some embodiments, X can be 32.00-50.00%, 34.00-50.00%, 36.00-50.00%, 38.00-50.00%, 40.00-50.00%, 42.00-50.00%. 44.00-50.00%, 46.00-50.00%, 30.00-48.00%, 30.00-46.00%, 30.00-44.00%, 30.00-42.00%, 30.00-40.00%, 30.00-38.00%, 30.00-36.00%, or 30.00-34.00%. In some embodiments, the lithium-free transparent spinel glass-ceramics described above can include an X value of 30.00%, 32.00%, 34.00%, 36.00%, 38.00%, 40.00%, 42.00%, 44.00%, 46.00%, 48.00%, or 50.00%, or a value of X within a range defined by any two of the above-mentioned specific values as endpoints. It is understood that in specific embodiments, any of the above-mentioned ranges can be combined with any other range, as long as the resulting glass has the desired properties.

[0155] In some embodiments, Y can be 62.00-80.00%, 64.00-80.00%, 66.00-80.00%, 68.00-80.00%, 70.00-80.00%, 72.00-80.00%. 74.00-80.00%, 76.00-80.00%, 60.00-78.00%, 60.00-76.00%, 60.00-74.00%, 60.00-72.00%, 60.00-70.00%, 60.00-68.00%, 60.00-66.00%, or 60.00-64.00%. In some embodiments, the lithium-free transparent spinel glass-ceramics described above can include a Y value of 60.00%, 62.00%, 64.00%, 66.00%, 68.00%, 70.00%, 72.00%, 74.00%, 76.00%, 78.00%, or 80.00%, or a value of Y within a range defined by any two of the above-mentioned specific values as endpoints. It is understood that in specific embodiments, any of the above-mentioned ranges can be combined with any other range, as long as the resulting glass has the desired properties.

[0156] In some preferred embodiments of the present application, the spinel crystals of the present application are zinc-magnesium spinel solid solution (Zn, Mg)Al2O4, i.e. the main crystal phase of the lithium-free transparent spinel glass-ceramics of the present application is (Zn, Mg)Al2O4; and / or, the lithium-free transparent spinel glass-ceramics of the present application further comprises a secondary crystal phase of tetragonal zirconia. (Zn, Mg)Al2O4 has high Young's modulus and shear modulus, which is beneficial to improve the intrinsic strength of the glass-ceramics and glass-ceramic products of the present application, such as to make the glass-ceramics and glass-ceramic products have high hardness, strength, fracture toughness, etc.

[0157] In some preferred embodiments of the present application, the lithium-free transparent spinel glass-ceramics of the present application has good crystallinity, for example, the crystallinity of the lithium-free transparent spinel glass-ceramics is 20 wt% or more; preferably, the crystallinity is 20.00-50.00 wt%; further preferably, the crystallinity is 30.00-50.00 wt%; more preferably, the crystallinity is 35-45 wt%. High crystallinity / crystal content can endow the glass-ceramics with higher intrinsic strength, so that the glass-ceramics and glass-ceramic products of the present application have excellent mechanical properties.

[0158] In some embodiments, the lithium-free transparent spinel glass-ceramics of the present application can have a crystallinity of 22.00-50.00 wt%, 24.00-50.00 wt%, 26.00-50.00 wt%, 28.00-50.00 wt%, 30.00-50.00 wt%, 32.00-50.00 wt%, 34.00-50.00 wt%, 36.00-50.00 wt%, 38.00-50.00 wt%, 40.00-50.00 wt%, 42.00-50.00 wt%, 44.00-50.00 wt%, 46.00-50.00 wt%, 20.00-48.00 wt%, 20.00-46.00 wt%, 20.00-44.00 wt%, 20.00-42.00 wt%, 20.00-40.00 wt%, 20.00-38.00 wt%, 20.00-36.00 wt%, 20.00-34.00 wt%, 20.00-32.00 wt%, 20.00-30.00 wt%, 20.00-28.00 wt%, 20.00-26.00 wt%, or 20.00-24.00 wt%. In some embodiments, the lithium-free transparent spinel glass-ceramics (also for chemical strengthening) described above can have a crystallinity value of 20.00 wt%, 22.00 wt%, 24.00 wt%, 26.00 wt%, 28.00 wt%, 30.00 wt%, 32.00 wt%, 34.00 wt%, 35.00 wt%, 36.00 wt%, 38.00 wt%, 40.00 wt%, 42.00 wt%, 44.00 wt%, 45.00 wt%, 46.00 wt%, 48.00 wt%, or 50.00 wt%, or a crystallinity value within a range defined by any two of the above specific values as endpoints. It should be understood that any of the above ranges can be combined with any other range to achieve the desired properties of the glass in the present application.

[0159] In some preferred embodiments of the present application, the lithium-free transparent spinel glass-ceramics of the present application have an average grain size of < 15.0 nm, preferably 1.0-15.0 nm, further preferably 1.0-10.0 nm, and more preferably 4.5-8.0 nm. Suitable grain size is beneficial to achieve excellent optical performance of the glass-ceramics.

[0160] In some embodiments, the lithium-free transparent spinel glass-ceramics of the present application can have an average grain size in the range of 1.0-13.0 nm, 1.0-11.0 nm, 1.0-9.0 nm, 1.0-7.0 nm, 1.0-5.0 nm, 1.0-3.0 nm, 3.0-15.0 nm, 3.0-13.0 nm, 3.0-11.0 nm, 3.0-9.0 nm, 3.0-7.0 nm, or 3.0-5.0 nm. In some embodiments, the lithium-free transparent spinel glass-ceramics described above can have an average grain size value of 1.0 nm, 3.0 nm, 4.5 nm, 5.0 nm, 7.0 nm, 8.0 nm, 9.0 nm, 10.0 nm, 11.0 nm, 13.0 nm, or 15.0 nm, or an average grain size value within a range defined by any two of the above-mentioned specific values as endpoints. It is understood that in specific embodiments, any of the above-mentioned ranges can be combined with any other range, as long as the resulting glass has the desired properties of the present application.

[0161] In yet another preferred embodiment of the present application, the lithium-free transparent spinel glass-ceramics of the present application exhibit high transparency in the visible range (i.e., the lithium-free transparent spinel glass-ceramics are transparent). The lithium-free transparent spinel glass-ceramics of the present application exhibit high transmittance in the visible range, for example, the lithium-free transparent spinel glass-ceramics have a transmittance of 85% or greater, preferably 89% or greater, for light of 550 nm wavelength at a thickness of 0.7 mm.

[0162] In some embodiments, the lithium-free transparent spinel glass-ceramics of the present application can have a transmittance of 89.0%, 89.5%, 90.0%, 90.5%, or 91.0% for light of 550 nm wavelength at a thickness of 0.7 mm, or a transmittance within a range defined by any two of the above-mentioned specific values as endpoints. It is understood that in specific embodiments, any of the above-mentioned ranges can be combined with any other range, as long as the resulting glass has the desired properties of the present application.

[0163] In some preferred embodiments of the present application, the lithium-free transparent spinel glass-ceramics of the present application have a Young's modulus of 100 GPa or greater, preferably a Young's modulus of 110 GPa or greater, and more preferably a Young's modulus in the range of 114 GPa to 140 GPa.

[0164] In some embodiments, the lithium-free transparent spinel glass-ceramics of the present application can have a Young's modulus in the range of 114-138 GPa, 114-136 GPa, 114-134 GPa, 114-132 GPa, 114-130 GPa, 114-128 GPa, 114-126 GPa, 116-140 GPa, 118-140 GPa, 120-140 GPa, 122-140 GPa, 124-140 GPa, 126-140 GPa, or 128-140 GPa. In some embodiments, the lithium-free transparent spinel glass-ceramics can have a Young's modulus of 100 GPa, 114 GPa, 116 GPa, 118 GPa, 120 GPa, 122 GPa, 124 GPa, 126 GPa, 128 GPa, 130 GPa, 135 GPa, or 140 GPa, or a Young's modulus within a range defined by any two of the foregoing specific values as endpoints. It will be understood that in specific embodiments, any of the foregoing ranges can be combined with any of the other ranges to obtain a glass having the desired properties of the present application.

[0165] In some preferred embodiments of the present application, the lithium-free transparent spinel glass-ceramics of the present application can have an optical b-value in the range of 0.20-1.50, preferably 0.50-1.20, at a thickness of 0.7 mm.

[0166] In some embodiments, the lithium-free transparent spinel glass-ceramics of the present application can have an optical b-value in the range of 0.20-1.40, 0.20-1.30, 0.20-1.20, 0.20-1.10, 0.20-1.00, 0.20-0.90, 0.20-0.80, 0.20-0.70, 0.20-0.60, 0.30-1.50, 0.40-1.50, 0.50-1.50, 0.60-1.50, 0.70-1.50, 0.80-1.50, 0.90-1.50, 1.00-1.50, or 1.10-1.50, at a thickness of 0.7 mm. In some embodiments, the lithium-free transparent spinel glass-ceramics can have an optical b-value of 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.10, 1.20, 1.30, 1.40, or 1.50, or an optical b-value within a range defined by any two of the foregoing specific values as endpoints. It will be understood that in specific embodiments, any of the foregoing ranges can be combined with any of the other ranges to obtain a glass having the desired properties of the present application.

[0167] In a second aspect, the lithium-free transparent spinel glass-ceramics can be produced and manufactured by a method comprising the following steps: (1) preparing a base glass comprising the following oxides in the following proportions in mol%: SiO2 38.00-48.00%, Al2O3 25.50-30.00%, ZrO2 3.00-5.00%, MgO 5.00-8.00%, ZnO 8.00-14.00%, Na2O 7.20-14.00%, B2O3 3.00-8.00%, K2O 0-2.00%, and Y2O3 0-1.00%, wherein the base glass is substantially free of Li2O, and the content of Li2O is less than 0.01% in mol%; and (2) producing the lithium-free transparent spinel glass-ceramics by heat treating the base glass.

[0168] In an exemplary embodiment, the method for producing the lithium-free transparent spinel glass-ceramics comprises the following steps:

[0169] (1) preparing a base glass comprising the following oxides in the following proportions in mol%: SiO2 38.00-48.00%, Al2O3 25.50-30.00%, ZrO2 3.00-5.00%, MgO 5.00-8.00%, ZnO 8.00-14.00%, Na2O 7.20-14.00%, B2O3 3.00-8.00%, K2O 0-2.00%, and Y2O3 0-1.00%, wherein the base glass is substantially free of Li2O, and the content of Li2O is less than 0.01% in mol%;

[0170] (2) producing the lithium-free transparent spinel glass-ceramics by heat treating the base glass.

[0171] It should be understood that the composition of the base glass is the same as that of the lithium-free transparent spinel glass-ceramics, in terms of mol% of oxides.

[0172] The heat treatment in step (2) can comprise nucleation treatment and / or crystallization treatment, i.e., the heat treatment of the base glass can be performed in one step or in two or more steps. If the heat treatment is performed in one step, it means that the nucleation treatment is not performed separately, and the nucleation and the growth of target crystals are performed in one temperature rising process, which can be understood as direct crystallization treatment. If the heat treatment is performed in two steps, it means that the heat treatment is performed in two temperature rising processes, i.e., the nucleation treatment is performed first, and then the growth of target crystals is performed.

[0173] It should be understood that, in the present application, the nucleation treatment is to raise the temperature to a specified nucleation treatment temperature (also referred to as nucleation temperature), and after reaching the nucleation treatment temperature, the temperature is maintained for a certain period of time (i.e. nucleation treatment time, also referred to as nucleation time). The crystallization treatment is to raise the temperature to a specified crystallization treatment temperature (also referred to as crystallization temperature), and after reaching the crystallization treatment temperature, the temperature is maintained for a certain period of time (i.e. crystallization treatment time, also referred to as crystallization time).

[0174] In order to make the lithium-free transparent spinel microcrystalline glass precipitate the desired crystal phase and obtain the desired physical and chemical properties, the preferred heat treatment process of the present application is:

[0175] The temperature of the nucleation treatment is 600-850℃, and the nucleation treatment time can be 0-72h, preferably 0-24h; the temperature of the crystallization treatment is 700-1000℃, and the crystallization treatment time is 0.1-72h, preferably 0.1-24h.

[0176] It is worth mentioning that the inventors have found through a large number of experiments that, due to the optimization of the formula in the present application, the desired target microcrystalline glass can be prepared at a lower heat treatment temperature than the existing scheme, therefore, in the present application, the temperature of the nucleation treatment can be preferably 600-750℃, and the temperature of the crystallization treatment can be preferably 700-800℃, which is more conducive to improving the mass production performance of the microcrystalline glass and is also more in line with the development needs of energy saving and carbon reduction in the industry.

[0177] In some preferred embodiments of the present application, a two-step temperature rising heat treatment method is used to prepare the lithium-free transparent spinel microcrystalline glass, i.e. the nucleation treatment and the crystallization treatment are sequentially performed on the base glass to prepare the microcrystalline glass. In some embodiments, when the temperature of the nucleation treatment is 600-750℃, the nucleation treatment time is preferably 60-360min, and the nucleation time is more preferably 100-300min; and / or, when the temperature of the crystallization treatment is 700-800℃, the crystallization treatment time is preferably 60-360min, and the crystallization time is more preferably 100-300min.

[0178] In some preferred embodiments of the present application, when performing the heat treatment, the temperature rising rate is controlled to be 5-15K / min, and the temperature rising rate is preferably 10K / min. It should be understood that the temperature rising rate here includes the temperature rising rate from room temperature to the nucleation temperature, and also includes the temperature rising rate from the nucleation temperature to the crystallization temperature.

[0179] In some preferred embodiments of the present application, the composition of the base glass of the present application satisfies:

[0180] A = 0.65 x Al2O3 + 3.5 x ZrO2 - 0.8 x Na2O - 2.5 x B2O3, wherein A is less than or equal to 0.18, preferably the value of A is 0.05 to 0.15;

[0181] and / or B = 3.8 x Na2O + B2O3 + 4.5 x MgO + 6.0 x ZnO - 0.4 x Al2O3 - SiO2, wherein B is less than or equal to 0.80, preferably the value of B is 0.60 to 0.78;

[0182] and / or X = 2.1 x (Al2O3 - MgO - ZnO) / (SiO2 + Al2O3 - MgO - ZnO + Na2O + K2O + B2O3), wherein X is 30.00 to 50.00%, preferably X is 34.00 to 46.00%;

[0183] and / or Y = (2.7 x Na2O + 1.8 x (Al2O3 - MgO - ZnO)) / (SiO2 + Al2O3 - MgO - ZnO + Na2O + K2O + B2O3), wherein Y is 60.00 to 80.00%, preferably Y is 60.00 to 75.00%;

[0184] and / or the Al2O3 content in the chemically strengthened glass-ceramic is 0.5 to 5.0 mol%. 3、 The molar percentage of each component of MgO and ZnO satisfies the following relationship: Al2O3 - MgO - ZnO = 8.00 to 15.00%.

[0185] In some preferred embodiments of the present application, the substrate glass of the present application contains substantially no BaO, i.e. BaO is less than 0.01% in terms of mol%, and / or the substrate glass contains substantially no TiO2, i.e. TiO2 is less than 0.01% in terms of mol%.

[0186] In the present application, the lithium-free transparent spinel glass-ceramic obtained in step (2) can be subjected to cold working treatment as needed, which is to process the glass-ceramic into a glass-ceramic sample, for example, by one or more of slicing, grinding and polishing to process the glass-ceramic into a polished piece of desired size, such as a polished piece with a length of 50 mm, a width of 50 mm and a thickness of 0.7 mm.

[0187] In the present application, the thickness of the lithium-free transparent spinel glass-ceramic can be selected by those skilled in the art as needed, and for example, the thickness of the lithium-free transparent spinel glass-ceramic is 0.2 to 5.0 mm.

[0188] In the present application, the forming method of the substrate glass includes but is not limited to float method, overflow method, calendering method or casting method. Illustratively, the components are mixed uniformly according to the formula, after melting forming, cooling and annealing treatment, the substrate glass can be obtained. Preferably, the mixed raw materials are placed in an electric furnace or gas furnace for melting treatment at a melting temperature of 1250-1650°C, more preferably at a melting temperature of 1480-1650°C, and the melting time is 5-24 hours; after the melting treatment is completed, the glass liquid is cast into a mold for forming, and after cooling to 850-1000°C, the glass is preferably placed in an annealing furnace for annealing treatment, the annealing temperature is 500-650°C, and the annealing time is 12-48 hours.

[0189] In the present application, when preparing the substrate glass, a fining agent can be added to the raw materials for preparing the substrate glass, the fining agent includes but is not limited to one or more of NaCl, Na2SO4, SnO2, As2O3, Sb2O3, NaNO3, KNO3, CeO2 and (NH4)2SO4; preferably one or more of NaCl, SnO2, NaNO3 and CeO2. The fining agent is added in an amount of 0.01wt% to 2.00wt%, preferably 0.01wt% to 1.50wt%, based on the total mass of the raw materials of the substrate glass.

[0190] In a third aspect, the present application also provides a chemically strengthened glass, which is obtained by chemically strengthening the lithium-free transparent spinel glass-ceramic or the lithium-free transparent spinel glass-ceramic prepared by the method described above or the substrate glass described above. The lithium-free transparent spinel glass-ceramic described above is chemically strengthened to obtain a strengthened glass-ceramic, which comprises a compressive stress layer and a tensile stress layer.

[0191] In some embodiments, the lithium-free transparent spinel glass-ceramic described above can be processed into a sheet, and / or shaped (such as punched, heat-bent, etc.), polished and / or ground after shaping, and then chemically strengthened by a chemical strengthening process.

[0192] The chemical strengthening process described in the present application is ion exchange method. In the ion exchange process, the smaller alkali metal ions in the lithium-free transparent spinel glass-ceramic are replaced or "exchanged" by larger alkali metal ions with the same valence near the glass-ceramic, and the smaller ions are replaced by larger ions to form a compressive stress layer in the glass. The ion exchange strengthening method can be carried out in multiple steps, such as two steps, or in a single step. Ion exchange is carried out by immersing the glass-ceramic or substrate glass in a salt bath containing at least one molten salt of larger alkali metal ions, so that the larger alkali metal ions in the salt bath replace the smaller alkali metal ions in the glass-ceramic or substrate glass. Alternatively, other monovalent metal ions such as Ag + , Tl+ Cu + Other ions such as Na+, K+, Ag+, Tl+, and the like can also be used to exchange the monovalent ions. The ion exchange process can include, but is not limited to, immersing the glass in a single salt bath, or immersing the glass in multiple salt baths with the same or different compositions, and between immersions, wash and / or annealing steps can be provided.

[0193] In some embodiments, the lithium-free transparent spinel glass-ceramics or substrate glass of the present application can be immersed in a salt bath containing potassium salt for chemical strengthening treatment. In some embodiments, the temperature of the salt bath for chemical strengthening treatment is in the range of 380-600°C, preferably in the range of 400-550°C. Exemplarily, the glass-ceramics or substrate glass can be immersed in a salt bath containing molten potassium salt (such as one or more of potassium nitrate, potassium sulfate, potassium carbonate, preferably potassium nitrate KNO3) at a temperature in the range of about 380-600°C for about 4-48 hours for ion exchange, preferably the temperature of the salt bath for chemical strengthening treatment is in the range of 400-550°C, more preferably the temperature of the salt bath is in the range of 450-500°C, and preferably the ion exchange / chemical strengthening time is in the range of 12-48 hours.

[0194] In some preferred embodiments of the present application, the concentration of potassium salt in the salt bath for chemical strengthening treatment is in the range of 60wt%-100wt%. Exemplarily, the salt bath containing potassium salt can be 100wt% potassium nitrate, or a mixture of potassium nitrate and sodium nitrate, and the concentration of potassium nitrate in the mixture is greater than or equal to 60wt% and less than 100wt%. In addition, 0-1wt% of LiNO3 can be added to the salt bath as needed, based on the mass of the salt bath.

[0195] In the present application, through the chemical strengthening treatment step, K ions in the salt bath replace part of the Na ions in the glass-ceramics or substrate glass, thereby forming a compressive stress layer at the surface of the glass, obtaining a strengthened glass-ceramics, and achieving a specific stress distribution structure for the glass-ceramics or substrate glass, thereby endowing the glass-ceramics or substrate glass with specific and excellent surface stress properties and deep stress properties, and further endowing it with high mechanical properties.

[0196] In some embodiments, before the chemical strengthening treatment, the glass-ceramics or substrate glass can be preheated at 300-400°C as needed, and preferably the preheating time is in the range of 10-30min.

[0197] In some embodiments, a thermal migration process at 350-500°C can be performed as needed between multiple strengthening steps, and preferably the thermal migration time is in the range of 15-120min.

[0198] In some embodiments, in the single-step or multi-step strengthening process, after a plurality of batches of samples are continuously strengthened in a salt bath, when the surface CS of a batch of samples decreases to 10-20% of the initial batch, the strengthening in the salt bath is stopped, and the salt bath needs to be purified or replaced for the glass strengthening.

[0199] In some preferred embodiments of the present application, the strengthened glass-ceramics comprise a compressive stress layer and a tensile stress layer, the main crystal phase of the strengthened glass-ceramics is (Zn, Mg)Al2O4, and the secondary crystal phase comprises tetragonal ZrO2; the strengthened glass-ceramics essentially do not contain Li2O, and the content of Li2O is less than 0.01% in terms of mol%.

[0200] It should be understood that after the chemical strengthening ion exchange process, the composition at the surface of the glass-ceramics or the substrate glass can be different from that of the as-formed glass-ceramics or substrate glass (i.e., the glass-ceramics or substrate glass without ion exchange). That is, the composition of the compressive stress layer formed on the surface of the strengthened glass-ceramics by ion exchange can be different from that of the glass-ceramics for chemical strengthening (i.e., lithium-free transparent spinel glass-ceramics). This is because during ion exchange, one type of alkali metal ions (e.g., Li + or Na + ) in the as-formed glass-ceramics or substrate glass is replaced by a larger alkali metal ion (e.g., Na + or K + ), such as the exchange of Na + in the glass with K + in the strengthening salt bath, and the replacement of K + , and / or the exchange of Li + in the glass with Na + in the strengthening salt bath, and the replacement of Na + . However, in embodiments, the composition of the glass-ceramics or substrate glass at the center or near the center of the depth of the glass article can still have the composition of the as-formed glass-ceramics or substrate glass. That is, in the present application, the composition of the tensile stress layer of the strengthened glass-ceramics still has the composition of the above-mentioned lithium-free transparent spinel glass-ceramics (i.e., the glass-ceramics for chemical strengthening in the present application) of the present application.

[0201] In the present application, due to the exchange of alkali metal ions during the chemical strengthening process, the main crystal phase of the chemical strengthening glass-ceramics, i.e., the lithium-free transparent spinel glass-ceramics, is (Zn, Mg)Al2O4, and the secondary crystal phase comprises tetragonal ZrO2, which do not participate in ion exchange, and thus, the main crystal phase of the strengthened glass-ceramics obtained after chemical strengthening is still (Zn, Mg)Al2O4, and the secondary crystal phase comprises tetragonal ZrO2.

[0202] The present application has made a deep research on the intrinsic strength of the glass-ceramics and the stress characteristics that the glass can obtain after being strengthened. By making the specific system of the glass-ceramics with high intrinsic strength meet the specific stress characteristics after being strengthened, a strengthened glass-ceramics with excellent mechanical properties, such as excellent anti-drop impact performance, is finally obtained. In the present application, the excellent surface stress characteristics and deep stress characteristics are endowed to the strengthened glass-ceramics through the chemical strengthening process, which is combined with the high intrinsic strength of the glass-ceramics, so that the mechanical properties of the strengthened glass-ceramics are greatly improved, and the anti-drop impact effect of the strengthened glass-ceramics is much better than that of the existing spinel glass-ceramics.

[0203] In some preferred embodiments of the present application, the strengthened glass-ceramics satisfies: a compressive stress layer depth DOL_0≥0.13t, preferably 0.22t≥DOL_0≥0.15t, and t is the thickness of the strengthened glass-ceramics. In some embodiments, DOL_0 can be 0.15t-0.21t, 0.15t-0.20t, 0.15t-0.19t, 0.15t-0.18t, 0.15t-0.17t, 0.16t-0.21t, 0.17t-0.21t, 0.18t-0.21t or 0.19t-0.21t. In some embodiments, the DOL_0 of the above strengthened glass-ceramics can be 0.13t, 0.15t, 0.16t, 0.17t, 0.18t, 0.19t, 0.20t, 0.21t or 0.22t, or DOL_0 within the numerical range formed by any two of the above specific values as endpoints. Exemplarily, when the thickness of the strengthened glass-ceramics is 0.7mm, the compressive stress layer depth DOL_0≥91.00μm, preferably 105-150μm, the compressive stress layer depth DOL_0 can be 91.00μm, 105.00μm, 112.00μm, 119μm, 126.00μm, 133.00μm, 140.00μm, 147.00μm or 154.00μm, or DOL_0 within the numerical range formed by any two of the above specific values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the glass with the required performance of the present application can be obtained.

[0204] In some specific embodiments of the present application, the thickness t of the strengthened glass-ceramics is 0.2-5.0mm, preferably 0.3-2.0mm, more preferably 0.4-1.5mm.

[0205] In some preferred embodiments of the present application, the strengthened glass-ceramics satisfy: |CT_CV|≥80MPa, preferably 300MPa≥|CT_CV|≥80MPa. In some embodiments, |CT_CV| can be 80-280MPa, 80-260MPa, 80-240MPa, 80-220MPa, 80-200MPa, 80-180MPa, 80-160MPa, 100-280MPa, 120-280MPa, 140-280MPa, 160-280MPa, or 180-280MPa. In some embodiments, |CT_CV| of the above strengthened glass-ceramics can be 80MPa, 100MPa, 120MPa, 140MPa, 160MPa, 180MPa, 200MPa, 220MPa, 240MPa, 260MPa, 280MPa, or 300MPa, or |CT_CV| within a range defined by any two of the above specific values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the resulting glass has the desired properties of the present application.

[0206] In some preferred embodiments of the present application, the strengthened glass-ceramics satisfy: |CT_AV|≥70MPa, preferably 200MPa≥|CT_AV|≥70MPa. In some embodiments, |CT_AV| can be 70-180MPa, 70-160MPa, 70-140MPa, 70-120MPa, 70-100MPa, 90-180MPa, 110-180MPa, 130-180MPa, or 150-180MPa. In some embodiments, |CT_AV| of the above strengthened glass-ceramics can be 70MPa, 90MPa, 110MPa, 120MPa, 140MPa, 160MPa, 180MPa, or 200MPa, or |CT_AV| within a range defined by any two of the above specific values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the resulting glass has the desired properties of the present application.

[0207] In some preferred embodiments of the present application, the strengthened glass-ceramics satisfy: CS_50≥100MPa, preferably 500MPa≥CS_50≥140MPa. In some embodiments, CS_50 can be 140-480MPa, 140-460MPa, 140-440MPa, 140-420MPa, 140-400MPa, 140-380MPa, 140-360MPa, 140-340MPa, 160-480MPa, 180-480MPa, 200-480MPa, 220-480MPa, 240-480MPa, 260-480MPa, or 280-480MPa. In some embodiments, CS_50 of the above strengthened glass-ceramics can be 100MPa, 140MPa, 160MPa, 180MPa, 200MPa, 220MPa, 240MPa, 260MPa, 280MPa, 300MPa, 320MPa, 340MPa, 360MPa, 380MPa, 400MPa, 420MPa, 440MPa, 460MPa, 480MPa, or 500MPa, or a CS_50 within a range defined by any two of the above specific values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the resulting glass has the desired properties of the present application.

[0208] In some preferred embodiments of the present application, the strengthened glass-ceramics satisfy: CT_LD is 40000MPa / mm-85000MPa / mm, preferably 45000MPa / mm-85000MPa / mm, more preferably 48000MPa / mm-85000MPa / mm. In some embodiments, CT_LD can be 40000-80000MPa / mm, 40000-75000MPa / mm, 40000-70000MPa / mm, 40000-65000MPa / mm, 40000-60000MPa / mm, 45000-85000MPa / mm,

[0209] 50000MPa / mm-85000MPa / mm, 55000MPa / mm-85000MPa / mm,

[0210] 60000 MPa / mm-85000 MPa / mm or 65000 MPa / mm-85000 MPa / mm. In some embodiments, the compressive stress linear density CT LD of the strengthened glass-ceramic can be 40000 MPa / mm, 45000 MPa / mm, 50000 MPa / mm, 55000 MPa / mm, 60000 MPa / mm, 65000 MPa / mm,

[0211] 70000 MPa / mm, 75000 MPa / mm, 80000 MPa / mm or 85000 MPa / mm, or a compressive stress linear density CT LD within a range defined by any two of the above specific values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range to obtain a glass having the desired properties of the present application.

[0212] In some preferred embodiments of the present application, the surface K2O concentration of the strengthened glass-ceramic is ≥ 9.00 wt%, preferably 9.00-16.00 wt%. In some embodiments, the surface K2O concentration of the strengthened glass-ceramic can be 9.00-15.00 wt%, 9.00-14.00 wt%, 9.00-13.00 wt%, 9.00-12.00 wt%, 9.00-11.00 wt%, 10.00-16.00 wt%, 11.00-16.00 wt%, 12.00-16.00 wt%, 13.00-16.00 wt% or 14.00-16.00 wt%. In some embodiments, the surface K2O concentration of the strengthened glass-ceramic can be 9.00 wt%, 10.00 wt%, 11.00 wt%, 12.00 wt%, 13.00 wt%, 14.00 wt%, 15.00 wt% or 16.00 wt%, or a surface K2O concentration within a range defined by any two of the above specific values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range to obtain a glass having the desired properties of the present application.

[0213] It should be understood that the strengthened glass-ceramic of the present application is obtained by chemical strengthening of the above lithium-free transparent spinel glass-ceramic provided by the present application, and in the lithium-free transparent spinel glass-ceramic of the present application, the main crystal phase is (Zn, Mg)Al2O4, the secondary crystal phase includes tetragonal ZrO2, the crystal phase does not contain alkali metals and does not participate in ion exchange, so the crystal phase composition does not change substantially before and after strengthening.

[0214] In some preferred embodiments of the present application, the crystallinity of the strengthened glass-ceramics is ≥ 20.00 wt%; preferably, the crystallinity is 20.00-50.00 wt%; further preferably, the crystallinity is 30.00-50.00 wt%; more preferably, the crystallinity is 35.00-45.00 wt%.

[0215] In some preferred embodiments of the present application, the average grain size of the strengthened glass-ceramics is ≤ 15.0 nm, preferably 1.0-15.0 nm, further preferably 1.0-10.0 nm, more preferably 4.5-8.0 nm.

[0216] It should be understood that, in the present application, the composition of the crystalline phase in the glass-ceramics is substantially unchanged after the chemical strengthening treatment, and the optical properties of the glass-ceramics, such as the transmittance and the optical b value, are also substantially unchanged.

[0217] In some preferred embodiments of the present application, the strengthened glass-ceramics is transparent in the visible light range. Preferably, the transmittance of the strengthened glass-ceramics is greater than or equal to 85% for light with a wavelength of 550 nm at a thickness of 0.7 mm, preferably greater than or equal to 89%; and / or the absolute value of the optical b value of the strengthened glass-ceramics is 0.20-1.50, preferably 0.50-1.20, at a thickness of 0.7 mm.

[0218] In some preferred embodiments of the present application, the Vickers hardness of the strengthened glass-ceramics is 700-900 kgf / mm 2 In some embodiments, the Vickers hardness of the strengthened glass-ceramics can be 700-890 kgf / mm 2 , 700-880 kgf / mm 2 , 700-870 kgf / mm 2 , 700-860 kgf / mm 2 , 700-850 kgf / mm 2 , 700-840 kgf / mm 2 , 700-830 kgf / mm 2 , 700-820 kgf / mm 2 , 700-810 kgf / mm 2 , 700-800 kgf / mm 2 , 710-900 kgf / mm 2 , 720-900 kgf / mm 2 , 730-900 kgf / mm 2 , 740-900 kgf / mm 2 , 750-900 kgf / mm 2, 760 ~ 900 kgf / mm 2 , 770 ~ 900 kgf / mm 2 , 780 ~ 900 kgf / mm 2 , 790 ~ 900 kgf / mm 2 , or 800 ~ 900 kgf / mm 2 In some embodiments, the strengthened glass-ceramics described above can have a Vickers hardness of 700 kgf / mm 2 , 710 kgf / mm 2 , 720 kgf / mm 2 , 730 kgf / mm 2 , 740 kgf / mm 2 , 750 kgf / mm 2 , 760 kgf / mm 2 , 770 kgf / mm 2 , 780 kgf / mm 2 , 790 kgf / mm 2 , 800 kgf / mm 2 , 810 kgf / mm 2 , 820 kgf / mm 2 , 830 kgf / mm 2 , 840 kgf / mm 2 , 850 kgf / mm 2 , 860 kgf / mm 2 , 870 kgf / mm 2 , 880 kgf / mm 2 , 890 kgf / mm 2 , or 900 kgf / mm 2 , or a Vickers hardness within a range defined by any two of the above specific values as endpoints. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range to provide a glass having the desired properties of the application.

[0219] In some preferred embodiments of the application, the strengthened glass-ceramics described above have a fracture toughness of greater than or equal to 1.00 MPa m 1 / 2 , preferably greater than or equal to 1.20 MPa m 1 / 2 , and further preferably greater than or equal to 1.50 MPa m 1 / 2 In some embodiments, the fracture toughness can be in the range of 1.00 to 2.00 MPa m 1 / 2 , 1.20 to 2.00 MPa m 1 / 2 , 1.40 to 2.00 MPa m 1 / 2 , 1.50 to 2.00 MPa m 1 / 21.00-1.80 MPa.m 1 / 2 1.00-1.60 MPa.m 1 / 2 1.00-1.40 MPa.m 1 / 2 or 1.00-1.20 MPa.m 1 / 2 In some embodiments, the fracture toughness can be 1.00 MPa.m 1 / 2 1.20 MPa.m 1 / 2 1.30 MPa.m 1 / 2 1.40 MPa

[0220] m 1 / 2 1.50 MPa.m 1 / 2 1.51 MPa.m 1 / 2 1.57 MPa.m 1 / 2 1.60 MPa.m 1 / 2 1.64 MPa.m 1 / 2 1.66 MPa.m 1 / 2 1.70 MPa.m 1 / 2 1.80 MPa.m 1 / 2 1.90 MPa.m 1 / 2 or 2.00 MPa.m 1 / 2 or a fracture toughness within a range defined by any two of the above specific values as endpoints. It should be understood that any of the above ranges can be combined with any other range to obtain a glass having the desired properties of the present application.

[0221] It should be understood that the Young's modulus of the glass-ceramic will increase somewhat after chemical strengthening, and the above lithium-free transparent spinel glass-ceramic (i.e., the glass-ceramic of the present application that is chemically strengthened) has a Young's modulus of > 100 GPa, preferably a Young's modulus of > 110 GPa, and more preferably a Young's modulus of 114 GPa < Young's modulus < 140 GPa. Thus, the strengthened glass-ceramic has a Young's modulus of > 100 GPa, preferably a Young's modulus of > 110 GPa, and more preferably a Young's modulus of 114 GPa < Young's modulus < 140 GPa.

[0222] In some preferred embodiments of the present application, the strengthened glass-ceramics of the present application are subjected to sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm. The average sandpaper drop height of the strengthened glass-ceramics is calculated based on the sandpaper drop test results of at least 10 identical strengthened glass-ceramic samples. The average sandpaper drop height of the strengthened glass-ceramics is greater than 1.5 m, preferably greater than or equal to 1.80 m, more preferably in the range of 1.80-2.50 m, and even more preferably in the range of 2.00-2.50 m. In some embodiments, the average sandpaper drop height of the strengthened glass-ceramics can be 1.80 m, 2.00 m, 2.10 m, 2.20 m, 2.30 m, 2.40 m, or 2.50 m, or in the range of the average sandpaper drop height between any two of the above-mentioned specific values as the end points. It should be understood that in specific embodiments, any of the above-mentioned ranges can be combined with any other range, as long as the glass with the desired properties of the present application can be obtained.

[0223] In some preferred embodiments of the present application, the strengthened glass-ceramics of the present application are subjected to 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm. If the glass sample does not break after the drop, it is recorded as a pass. The pass rate of the strengthened glass-ceramics is calculated based on the 2.5 m drop test results of at least 10 identical strengthened glass-ceramic samples. The pass rate of the strengthened glass-ceramics is greater than or equal to 50%, preferably greater than or equal to 60%, more preferably greater than or equal to 70%, and even more preferably in the range of 60-100%. In some embodiments, the pass rate of the strengthened glass-ceramics subjected to 2.5 m drop test (120 grit sandpaper) can be 60%, 70%, 80%, 90%, or 100%, or in the range of the pass rate of the 2.5 m drop test (120 grit sandpaper) between any two of the above-mentioned specific values as the end points. It should be understood that in specific embodiments, any of the above-mentioned ranges can be combined with any other range, as long as the glass with the desired properties of the present application can be obtained.

[0224] In a fourth aspect, the above-mentioned lithium-free transparent spinel glass-ceramics, the above-mentioned substrate glass for preparing lithium-free transparent spinel glass-ceramics, or the above-mentioned chemically strengthened glass can be applied to a mobile phone display screen, a tablet computer display screen, a handheld game console, an electronic terminal, a portable digital device, a vehicle-mounted central control screen, an electronic whiteboard glass, a smart home touch screen, a vehicle windshield, an aircraft windshield, or a ship windshield.

[0225] The preparation of the lithium-free transparent spinel glass-ceramics and the beneficial effects achieved are described in detail below through examples and comparative examples.

[0226] 1: Specific operation examples

[0227] Example 1

[0228] According to the component ratio of the glass formula 1 of example 1 in table 1, the raw materials (industrial conventional raw materials) are configured in a platinum crucible, the total amount of the configured raw materials is 1000g, then mixed for 30 minutes by a V-type mixer, after mixing, 5g of clarifying agent NaCl is added, then the raw materials are transferred to a platinum crucible, then melted in a 1650℃ lifting furnace (lifting furnace model: SJF1750, manufacturer: Nanjing Boyuntong Instrument Science and Technology Co., Ltd.) for 5 hours, then poured into a preheated stainless steel mold at 300℃ (usually preheated to 200-400℃ can be used) to form cooling, cooled to 900℃, then placed in a 600℃ annealing furnace for annealing for 24 hours, then cooled to room temperature with the furnace, to obtain the base glass.

[0229] The above base glass is heat treated in a resistance furnace (equipment model: SLX1400-40, manufacturer: Shanghai Shengli Testing Instrument Co., Ltd.), the heat treatment process (nucleation temperature / nucleation time, crystallization temperature / nucleation time, heating rate during heat treatment process) is carried out according to table 1, to obtain lithium-free transparent spinel glass-ceramic sample bricks. After cutting, CNC processing (computer numerical control, the CNC instrument used in the present application is RCG500S), polishing, the smooth glass-ceramic sheet is obtained. In the present application, the size of the processed glass-ceramic sheet is 50mm×50mm×0.7mm.

[0230] The physical parameters of the prepared glass-ceramic are tested by the following method:

[0231] Young's modulus test: the Young's modulus of the sample is obtained by acoustic wave test, and the instrument is UMS-100 ultrasonic material characterization system.

[0232] XRD test: the glass-ceramic sheet is ground into glass powder with a particle size of less than 75μm by a grinding machine, and then tested by an X-ray diffractometer (XRD-6100 of Shimadzu) to obtain an XRD diffraction peak curve. The X-ray diffractometer used in the present application is XRD-6100 of Shimadzu, the target material is copper, the test incident angle range is 2θ=10-80°, the scanning speed is 0.2° / min, the working voltage is 40kV, and the working current is 30mA. The crystal phase of the sample is obtained by analyzing the XRD diffraction data by JADE software.

[0233] Average grain size: the average grain size of the sample can be calculated according to the Scherrer formula D = Kλ / (βcosθ), wherein λ is the X-ray wavelength of 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 file (diffraction spectrum) output by the XRD instrument is curve-fitted in Jade software, and the fitting report is output by Jade. According to the angle 2θ value and the Peak FWHM value (half-height width of the diffraction peak) corresponding to each diffraction peak in the fitting report, and the Peak FWHM value is converted into radian system β = (FWHM / 180*3.14), the grain size of each diffraction peak is calculated by D = Kλ / (βcosθ), and then the average grain size is obtained by averaging.

[0234] Test method of crystal content / crystallinity: the X-ray diffraction test result file (RAW format) is imported into X-ray diffraction data Ri etvel d refinement software (such as Gsas, Full prof, Maud) for fitting and calculation, so that the crystal content / crystallinity in the glass-ceramic sample can be obtained. The ratio of the peak area of the fitted crystal phase to the total peak area is the crystal content, i.e. the crystallinity referred to in the application.

[0235] b value determination: the b value of the sample is tested by using a Japanese Konica Minolta spectrophotometer CM-3600A, and the average value of 5 parallel samples is taken as the b value result of the sample to be tested.

[0236] Transmittance determination: the test is carried out according to the standard of GB / T 7962.12-2010 Colorless optical glass Test methods Part 12: Spectral transmittance. First, the sample to be tested is cleaned in an ultrasonic cleaning machine, and the cleaning conditions are as follows: cleaning time 5-10 min; cleaning agent: commonly used washing agent diluted 10 times; cleaning temperature: 45-65℃; cleaning frequency: 20-40 KHZ. Then, the transmittance of the sample under different wavelengths of light is tested by using a haze meter (Japanese Konica Minolta spectrophotometer CM-3600A).

[0237] The transmittance of the sample to 550 nm wavelength light is measured by using a Japanese Konica Minolta spectrophotometer CM-3600A, and the average value of 5 parallel samples is taken as the transmittance result of the sample to be tested under 550 nm wavelength light.

[0238] Thickness of the glass: determined by micrometer test. It should be understood that in the thickness direction, the degree of ion exchange varies from the surface to the center in a gradient, and the total Na-K and / or Li-Na exchange amount is generally not more than 1% of the total mass of the sample, and the difference in ionic radius is pm level, so the expansion effect in the thickness direction is slight, and it can be approximately considered that the thickness is basically unchanged. That is, the thickness of the glass-ceramic changes very little before and after chemical strengthening, which can be ignored.

[0239] Determination of density: the density value of the glass-ceramic sample is tested according to the principle of "Archimedes drainage method", and the testing instrument used in the present application is ALFA MIRAGE electronic density balance SD-200L.

[0240] After the above performance tests are completed, then, the 0.7mm thick glass-ceramic samples obtained above are subjected to chemical strengthening treatment according to the mixed or elemental molten salt composition, ion exchange temperature and ion exchange time shown in Table 2, to obtain strengthened glass-ceramics.

[0241] Among them, the sample is subjected to single-step strengthening, and the specific process is as follows:

[0242] IOX (ion exchange): 480℃x100% KNO3x24h (referring to exchange in 100wt% KNO3 molten salt at 480℃ for 24h; similar expressions herein have similar meanings, and the molten salt temperature, composition and ion exchange time used for ion exchange are abbreviated in this form);

[0243] The physical property parameters of the prepared strengthened glass-ceramics are tested according to the following method:

[0244] In the present application, CS_50, |CT_CV|, |CT_AV| and DOL_0 are tested by using a stress meter SLP-2000 of Japan Luceo (Japan Orikata). The test conditions are as follows: light source wavelength is 518 nm, SOC = 25.5 (nm / cm) / MPa, refractive index = 1.60, and exposure time is 300 usec. When testing CS_50, |CT_CV|, |CT_AV| and DOL_0, the special refractive liquid for the stress meter is first dripped, then the strengthened microcrystalline glass product is wiped clean and placed on the test channel to test the stress value. The refractive index of the refractive liquid used by SLP-2000 is 1.51. Unless otherwise specified, the test stress value in the examples and comparative examples of the present application is tested under the above-mentioned test conditions. It should be noted that when testing the stress value of Comparative Examples 10-15, the photoelastic constant is set to 25.5 and the refractive index nd is 1.6; other conditions are the same as the above-mentioned examples; when testing the stress value of Comparative Example 7, the photoelastic constant is set to 25.5 and the refractive index nd is 1.54; other conditions are the same as the above-mentioned examples; when testing the stress value of Comparative Example 8, the photoelastic constant is set to 28.6 and the refractive index nd is 1.51; other conditions are the same as the above-mentioned examples.

[0245] The tensile stress line density CT_LD is related to the thickness of the glass sheet, the strengthening depth and the average tensile stress, and can be used to evaluate the drop resistance of the glass sheet. In the present application, the CT_LD is calculated according to the following formula:

[0246]

[0247] wherein t represents the thickness of the microcrystalline glass sheet (the thickness of the glass in the examples and comparative examples below is 0.7 mm), in mm; DOL_0 represents the depth of the compressive stress layer, in μm; CT_AV represents the average internal tensile stress, and the absolute value is taken when calculating, in MPa. It should be understood that in the calculation formula of the tensile stress line density, the data is substituted into the calculation according to the above-mentioned unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation.

[0248] The exchange amount is calculated by the ratio of the mass difference of the microcrystalline glass sheet before and after chemical strengthening to the mass of the microcrystalline glass sheet before chemical strengthening.

[0249] Surface K2O concentration test: In the present application, the surface K2O concentration of the strengthened glass ceramic is measured by an X-ray fluorescence spectrometer (XRF), the model of which is (Thermo Scientific ARL PERFORM’X), the target material is Rh (rhodium), the light tube voltage is 40 kW, the current is 60 mA, the collimator is 0.15, the crystal is selected as LiF200, the detector is selected as FPC, the test range is 29 mm circle, and the analysis software is Uniquant non-standard analysis.

[0250] Test of Vickers hardness (HV): The chemically strengthened strengthened glass ceramic is made into a small piece with a length, width and thickness of 50 mm*50 mm*0.7 mm, and a glass sample with a clean surface, no visible scratches, pits and cracks and other damages is selected as a test sample, and then a Vickers hardness tester is used to measure the Vickers hardness. The Vickers hardness tester used in the present application is a digital small load Vickers hardness tester (Beijing Kewei Technology Co., Ltd., VTD405). Test conditions: load 300 gf, loading time 10 s, and the validity of the indentation meets the standard of “GB / T 37900-2019 Test methods for hardness and fracture toughness of ultra-thin glass Small load Vickers indentation method”. Three different positions on the surface of the same sample are selected for measurement, and the average value of three measurement results is selected as the Vickers hardness result of the glass sample to be tested.

[0251] Test of fracture toughness: The test is carried out according to the standard of “GB / T 37900-2019 Test methods for hardness and fracture toughness of ultra-thin glass Small load Vickers indentation method”. Specifically, the indentation is prepared by the same method as measuring the Vickers hardness, the crack length 2C1, 2C2 in the diagonal direction of the indentation is measured, and the maximum value thereof cannot exceed the thickness of the glass. At least 5 effective indentation morphologies are measured on the surface of one sample, and the average value thereof is calculated as the final result value of the sample.

[0252] Indentation fracture toughness calculation formula:

[0253] Wherein, I FR: indentation fracture toughness, unit: megapascal and one second power meter (MPa·m 1 / 2 ); E: elastic modulus of the sample, unit: gigapascal (GPa); 2C1, 2C2: crack propagation length in the diagonal direction of the indentation, unit: millimeter (mm), d1, d2: diagonal length of the indentation, unit: millimeter (mm), F: test load value, unit: newton (N).

[0254] The test method of the average anti-falling height is that the average anti-sandpaper falling height of each sample is added and averaged to represent the anti-falling performance of the glass-ceramic. At least 10 identical glass samples are taken from each batch for testing, and the average anti-sandpaper falling height is:

[0255]

[0256] wherein n is the number of glass samples tested in each batch, and hi is the anti-sandpaper falling height of each sample;

[0257] The test method of the anti-sandpaper falling height of each sample is as follows:

[0258] Step 1: 120-mesh sandpaper is attached to the lower surface of a 160g model machine, and the model machine is placed on a green map LT-SKDL-CD type falling machine;

[0259] Step 2: A glass sample to be tested with a length, width and thickness of 50mm*50mm*0.7mm is placed directly below the model machine, with the glass sample facing the sandpaper. The model machine is dropped with a certain falling height to impact the glass sample directly below the model machine. If the glass sample does not break, the falling height of the model machine is increased in a certain manner. For example, the falling height is started from 0.4m, and the sample is impacted once. If it is not broken, the height is increased by 0.1m and dropped again until the glass sample is broken.

[0260] Step 3: The last falling height of the glass sample before breaking is recorded as the anti-sandpaper falling height. For example, if the falling height at the time of breaking is 0.5m, the anti-sandpaper falling height of the sample is 0.4m.

[0261] The test method of the 2.5m falling test passing rate is that the number of samples passing the 2.5m falling test is divided by the total number of samples to calculate the percentage of passing samples. After the falling test, if the glass sample does not break, it is recorded as passing, otherwise it is recorded as not passing. The test method is used to represent the anti-falling performance of the glass-ceramic. At least 10 identical glass samples are taken from each batch for testing.

[0262] Specifically, the test method of the 2.5m falling test of each sample is as follows:

[0263] Step 1: 120-mesh sandpaper is attached to the lower surface of a 160g model machine, and the model machine is placed on a green map LT-SKDL-CD type falling machine;

[0264] Step 2: Place the glass sample to be tested with a length, width and thickness of 50 mm*50 mm*0.7 mm directly below the model machine, with the glass sample facing the sandpaper. Allow the model machine to drop once with an impact height of 2.5 m, and impact the glass sample directly below the model machine. If the glass sample is not broken, it is recorded as passing, otherwise it is recorded as failing.

[0265] The test method for high temperature and high humidity failure time is as follows: a QTH_80C full temperature and humidity alternating test box is used for testing, and the alternating test box conditions are set as follows: the temperature is 85°C and the relative humidity is 85%. Every 12 hours, the sample is observed and taken out, and the glass surface is wiped with a dust-free cloth to observe whether there are spots and fog points that cannot be wiped off. If, at this observation time, the sample has spots and fog points that cannot be wiped off, and at the last observation time, the sample did not have spots and fog points that cannot be wiped off, then the time at which the sample is taken out for observation is taken as the node, and the time for which the glass sample is placed in the test box is calculated, which is recorded as the high temperature and high humidity failure time of the test sample, and is used to represent the weather resistance.

[0266] Examples 2-5 were operated under the same operating conditions as Example 1, and corresponding tests were performed. Table 1 shows the glass formula composition and heat treatment process of the base material glass of Examples 1-5, and the performance parameters of the lithium-free transparent spinel microcrystalline glass prepared thereby; Table 2 shows the strengthening conditions of the lithium-free transparent spinel microcrystalline glass in Examples 1-5 and the performance parameters of the strengthened microcrystalline glass prepared thereby.

[0267] Table 1 shows the glass formula, melting state, heat treatment process of the base material glass of Examples 1-5, and the performance parameters of the lithium-free transparent spinel microcrystalline glass prepared thereby.

[0268]

[0269]

[0270] Table 2 shows the chemical strengthening conditions of the lithium-free transparent spinel microcrystalline glass in Examples 1-5 and the performance parameters of the strengthened microcrystalline glass prepared thereby.

[0271]

[0272]

[0273] Note: 1. Since the longest time for high temperature and high humidity failure test in the present application is 360h (15 days), if the glass sample is still free of spots and / or fog points that cannot be wiped off after 360h, it is determined that the high temperature and high humidity failure time of the glass sample is greater than 360h; 2. The surface K2O content in the table, i.e. the surface K2O concentration in the present application.

[0274] Examples 6-10 were operated under the same operating conditions as Example 1, and corresponding tests were performed. Table 3 is the glass formulation composition of the base substrate glass and the heat treatment process of Examples 6-10, and the performance parameters of the lithium-free transparent spinel microcrystalline glass prepared thereby; Table 4 is the strengthening condition of the lithium-free transparent spinel microcrystalline glass in Examples 6-10 and the performance parameters of the strengthened microcrystalline glass prepared thereby.

[0275] Table 3 Glass formulation, melting state, heat treatment process of the base substrate glass of Examples 6-10 and the performance parameters of the lithium-free transparent spinel microcrystalline glass prepared thereby

[0276]

[0277]

[0278] Table 4 Chemical strengthening condition of the lithium-free transparent spinel microcrystalline glass in Examples 6-10 and the performance parameters of the strengthened microcrystalline glass prepared thereby

[0279]

[0280]

[0281] Note: 1. Since the longest time for high temperature and high humidity failure test in the present application is 360h (15 days), if the glass sample is taken out for observation after 360h, the sample still does not appear spots and / or fog points that cannot be wiped off, it is judged that the high temperature and high humidity failure time of the glass sample is greater than 360h; 2. The surface K2O content in the table, that is, the surface K2O concentration in the present application.

[0282] Examples 11-15, respectively, the same microcrystalline glass as Examples 1, 4, 5 was used, and the strengthening was performed under different strengthening conditions. The specific strengthening process used and the performance parameters of the strengthened microcrystalline glass prepared thereby are shown in Table 5.

[0283] Table 5 Chemical strengthening condition of Examples 11-15 and the performance parameters of the strengthened microcrystalline glass prepared thereby

[0284]

[0285] Note: 1. Since the longest time for high temperature and high humidity failure test in the present application is 360h (15 days), if the glass sample is taken out for observation after 360h, the sample still does not appear spots and / or fog points that cannot be wiped off, it is judged that the high temperature and high humidity failure time of the glass sample is greater than 360h; 2. The surface K2O content in the table, that is, the surface K2O concentration in the present application.

[0286] Figure 1 Figure for the melting result of the base substrate glass of Example 1,Figure 2 This is a diagram showing the melting result of the substrate glass in Example 3. Figure 3 This is a diagram showing the melting result of the substrate glass in Example 4. Figure 4 This is an appearance diagram of the lithium-free transparent spinel microcrystalline glass of Example 4. Figure 5 This is an appearance diagram of the lithium-free transparent spinel microcrystalline glass of Example 5, from... Figures 1-5 It can be seen that the substrate glass prepared by the glass formulation of the present invention and the lithium-free transparent spinel microcrystalline glass prepared under a specific heat treatment process are both transparent glass materials in the visible light range.

[0287] Figure 6 The thermogravimetric analysis (TGA) curve of the substrate glass in Example 1 is shown below. The TGA test method is as follows: the substrate glass of Example 1 was ground into powder and passed through a 200-mesh sieve; the test conditions were: room temperature to 1100℃, heating rate of 10℃ / min; the test instrument was a Mettler Toledo TGA / DSC3+ thermogravimetric and simultaneous thermal analyzer. The obtained raw data were imported into OrganPro software to obtain the following results: Figure 6 The thermogravimetric analysis curve shown below indicates an endothermic peak. Figure 6 It can be seen that the first endothermic peak is 735℃; the upward peak is the exothermic peak, and the first exothermic peak is 848℃.

[0288] Figure 7 The XRD diffraction pattern of the lithium-free transparent spinel glass-ceramic of Example 1 is shown in the figure. Figure 7 It can be seen that the main crystalline phase of this glass-ceramic is (Zn,Mg)Al2O4 (card numbers: 74-1136 and 73-1959), and the secondary crystalline phase is zirconium oxide (card number: 80-1007).

[0289] Figure 8 The transmittance curves of the lithium-free transparent spinel microcrystalline glass of Example 5 under different wavelength conditions are shown below. Figure 8 It can be seen that the transmittance of this microcrystalline glass is greater than 90% at a wavelength of 550nm.

[0290] Based on Tables 1 and 3, combined with Figures 1-3 It can be seen that when preparing substrate glass using the glass formulation provided by this invention, substrate glass with good overall uniformity and transparency can be melted. Furthermore, the substrate glass prepared by this invention can be used to prepare microcrystalline glass with high crystallinity and excellent optical properties, with (Zn,Mg)Al2O4 as the main crystalline phase and tetragonal zirconium oxide as the secondary crystalline phase, at a heat treatment temperature not exceeding 800℃. Specifically, the crystallinity of the microcrystalline glass prepared by this invention is 37.52-40.41 wt%, and the Young's modulus reaches over 101 GPa; at a wavelength of 550 nm, the transmittance of the lithium-free transparent spinel microcrystalline glass prepared by this invention is greater than or equal to 89%.

[0291] As can be seen from Table 2, Table 4 and Table 5, the lithium-free transparent spinel microcrystalline glass of the present application can be prepared into the strengthened microcrystalline glass satisfying the specific stress characteristics after chemical strengthening, which has excellent surface stress characteristics and excellent deep stress characteristics. Specifically, the strengthened microcrystalline glass obtained by the present application has |CT_AV| of 73.38-125.91 MPa, |CT_CV| of 89.07-146.38 MPa, DOL_0 of 108.69-132.50 μm, which is greater than 0.13 times of the glass thickness (0.7 mm), CT_LD of 49620-80192 MPa / mm, and CS_50 of 148.02-337.69 MPa, which indicates that the strengthened microcrystalline glass has excellent deep stress. At the same time, the surface K2O content (i.e. surface K2O concentration) of the strengthened microcrystalline glass is 9.16%-15.21%, which indicates that the higher the surface K2O content, the more K-Na exchange occurs in the strengthening process, and the higher the surface compressive stress that the microcrystalline glass can obtain, and the more excellent the surface stress characteristics. The strengthened microcrystalline glass satisfying the specific stress characteristics prepared by the present application is subjected to the sandpaper drop impact test, and it can be found that the average sandpaper drop height (120 mesh sandpaper) of the strengthened microcrystalline glass of the present application can be as high as 2 m or more. At the same time, when subjected to the fixed height drop test of 2.5 m, the pass rate of the strengthened microcrystalline glass of the present application is greater than or equal to 70%.

[0292] In addition, the high temperature and high humidity failure time of the strengthened microcrystalline glass of the present application can reach 360 h or more, which indicates that the strengthened microcrystalline glass of the present application has excellent weather resistance.

[0293] Comparative Examples 1-6 were operated according to the same operating conditions as Example 1, and the corresponding tests were conducted. Table 6 shows the glass formula composition of the prepared base glass of Comparative Examples 1-6 and the melting state of the prepared base glass.

[0294] Table 6 shows the glass formula composition of the prepared base glass of Comparative Examples 1-6 and the melting state of the prepared base glass.

[0295]

[0296]

[0297] As can be seen from Table 6, the B value in Comparative Example 1 is 0.89, which is greater than 0.8, and the melting condition is as follows: Figure 9As shown, the base substrate glass after melting appears to be ceramicized; in Comparative Example 2, the Al2O3 content is too high, the B2O3 content is less and the A value is 0.24, which is greater than 0.18, resulting in melting defects, such as Figure 10 As shown, a large amount of unmelts appear in the base substrate glass after melting; in Comparative Example 3, the B2O3 content is less and the A value is 0.21, which is greater than 0.18, such as Figure 11 As shown, white precipitates appear in the base substrate glass after melting; in Comparative Example 4, the ZrO2 content is too high and the A value is 0.19, which is greater than 0.18, and white precipitates appear in the base substrate glass after melting; in Comparative Example 5, the MgO content is high and the B value is 0.84, which is greater than 0.8, and the base substrate glass after melting appears to be ceramicized; in Comparative Example 6, the ZnO content is high and the B value is 1.05, which is greater than 0.8, and the melting condition is as shown in Figure 12 As shown, the base substrate glass after melting appears to be ceramicized.

[0298] Comparative Examples 7-13 were operated according to the same operating conditions as Example 1, and corresponding tests were performed. Table 7 is the glass formula composition of the base substrate glass prepared in Comparative Examples 7-13, the melting state, the heat treatment process and the performance parameters of the microcrystalline glass prepared thereby; Table 8 is the chemical strengthening condition of the microcrystalline glass prepared in Comparative Examples 7-12 and the performance parameters of the strengthened microcrystalline glass prepared thereby. Among them, the glass formula of Comparative Example 9 and Comparative Example 13 is the same, that is, the base substrate glass prepared thereby is the same. Comparative Example 9 does not perform nucleation treatment, but only one-step heat treatment, that is, direct heating for crystallization treatment; Comparative Example 13 is crystallized at 800℃ for 240min, but no crystals are precipitated, but phase separation occurs, and the transmittance decreases; Comparative Example 12 does not perform separate nucleation treatment; Comparative Example 9 and Comparative Example 13 do not perform ion strengthening treatment; Comparative Example 7 is strengthened by using two conditions of 450℃×100% NaNO3×9h and 450℃×30% NaNO3+70% KNO3×8h, respectively.

[0299] Table 7 is the glass formula composition of the base substrate glass prepared in Comparative Examples 7-13, the melting state, the heat treatment process and the performance parameters of the microcrystalline glass prepared thereby

[0300]

[0301]

[0302]

[0303] Table 8 is the chemical strengthening condition of the microcrystalline glass prepared in Comparative Examples 7-12 and the performance parameters of the strengthened microcrystalline glass prepared thereby

[0304]

[0305]

[0306]

[0307] Note: 1. The longest time for high temperature and high humidity failure test in the present application is 360 h (15 days), if the glass sample is still free of spots and / or fog that cannot be wiped off after 360 h, it is judged that the high temperature and high humidity failure time of the glass sample is greater than 360 h; 2. The surface K2O content in the table is the surface K2O concentration in the present application.

[0308] It should be noted that the glass formula of Comparative Example 8 contains K2O, therefore, the measured surface K2O is not entirely the result of ion exchange, therefore, the surface K2O value of Comparative Example 8 is not given in Table 8.

[0309] Comparative Examples 14-19 were operated according to the same operating conditions as Example 1, and corresponding tests were performed. Table 9 is the glass formula composition, melting state, heat treatment process of the base material glass prepared in Comparative Examples 14-19, and the performance parameters of the microcrystalline glass prepared thereby; Table 10 is the chemical strengthening condition of the microcrystalline glass prepared in Comparative Examples 14-16, and the performance parameters of the strengthened microcrystalline glass prepared thereby; in addition, Comparative Examples 17-19 were not subjected to strengthening treatment.

[0310] Table 9 is the glass formula composition, melting state, heat treatment process of the base material glass prepared in Comparative Examples 14-19, and the performance parameters of the microcrystalline glass prepared thereby

[0311]

[0312]

[0313] Table 10 is the chemical strengthening condition of the microcrystalline glass prepared in Comparative Examples 14-16, and the performance parameters of the strengthened microcrystalline glass prepared thereby

[0314]

[0315] Note: 1. The longest time for high temperature and high humidity failure test in the present application is 360 h (15 days), if the glass sample is still free of spots and / or fog that cannot be wiped off after 360 h, it is judged that the high temperature and high humidity failure time of the glass sample is greater than 360 h; 2. The surface K2O content in the table is the surface K2O concentration in the present application.

[0316] As can be seen from Table 7 and Table 9, the content of Na2O in Comparative Example 9 is low, and no crystalline phase appears in the glass after heat treatment at a temperature lower than 800℃, and mullite appears after heat treatment at a temperature of 900℃, and the transmittance of the final prepared glass-ceramic sample is low, and the glass-ceramic sample is opaque; the content of MgO in Comparative Example 17 is low, and the average grain size of the glass-ceramic sample after crystallization is too large, and the transmittance is low, and the optical performance of the sample is poor; the content of ZnO in Comparative Example 18 is low, and the average grain size of the glass-ceramic sample after crystallization is too large, and a heterogeneous phase appears, and the transmittance is low, and the optical performance of the sample is poor; the content of Li2O in Comparative Example 19 is high, and the glass-ceramic sample after crystallization is seriously fogged, and the average grain size is too large, and a heterogeneous phase quartz SS appears, and the transmittance is low, and the optical performance of the sample is extremely poor, as shown in Table 7. Figure 13

[0317] As can be seen from Table 8 and Table 10, the content of Al2O3 in Comparative Example 10 is low, and the stress level of the final prepared strengthened glass-ceramic is low, and the anti-drop impact performance is poor; the value of X in Comparative Example 12 is 23.94%, and the value of Y is 44.77%, and the value of X in Comparative Example 14 is 29.95%, and the value of Y is 55.08%, and both of them do not satisfy the conditions of X = 30-50% and Y = 60-80%, and the stress level of the final prepared strengthened glass-ceramic is also poor, specifically, the average anti-sandpaper drop height of the strengthened glass-ceramic in Comparative Example 12 and Comparative Example 14 is lower than 1.4m when the drop test is performed by using 120-mesh sandpaper, which is far lower than the strengthened glass-ceramic prepared in the embodiments of the present application, and at the same time, the glass in Comparative Example 12 and Comparative Example 14 is broken when the 2.5m fixed-point height drop test is performed, and the pass rate is 0; the value of Y in Comparative Example 15 does not satisfy the condition of 60-80%, and the content of BaO and Al2O3 in the component also does not satisfy the requirements of the present application, and the stress level of the final prepared strengthened glass-ceramic is poor, and the average anti-sandpaper drop height is 0.6m when the drop test is performed by using 120-mesh sandpaper, which is far lower than the strengthened glass-ceramic prepared in the embodiments of the present application, and at the same time, the test pass rate of the strengthened glass-ceramic in Comparative Example 15 is also 0 when the 2.5m fixed-point height drop test is performed; the value of X in Comparative Example 11 is 38.15%, and the value of Y is 66.64%, but the component contains 2.21mol% of BaO, and the stress level after strengthening is low, and the anti-drop impact performance is poor. The value of X in Comparative Example 16 is 35.50%, and the value of Y is 59.10%, the value of X satisfies the condition of 30-50%, but the value of Y does not satisfy the condition of 60-80%, and the deep stress level of the prepared strengthened glass-ceramic is poor, and the average anti-sandpaper drop height is 1.02m when the drop test is performed by using 120-mesh sandpaper, which is far lower than the strengthened glass-ceramic prepared in the embodiments of the present application.

[0318] ​In summary, the strengthened microcrystalline glass prepared from the lithium-free transparent microcrystalline glass has excellent mechanical properties, such as excellent anti-drop impact performance. Specifically, the average sandpaper drop height (tested using 120-mesh sandpaper) of the strengthened microcrystalline glass of the present application is as high as 2 m or more. When performing a 2.5-m fixed-height drop test, the pass rate of the strengthened microcrystalline glass of the present application is greater than or equal to 70%. The drop level is comparable to that of Comparative Example 7 of high-crystallinity lithium aluminum silicon microcrystalline strengthened glass and is much higher than that of Comparative Example 8 of existing ordinary two-strength glass.

[0319] At the same time, since the present application does not contain Li2O, the raw material cost is much lower than that of Comparative Example 7 and Comparative Example 8, and the practical value is very considerable. Moreover, the base glass prepared from the glass formula of the present application can obtain transparent microcrystalline glass with main crystal phase of zinc-magnesium spinel solid solution and excellent optical performance and high intrinsic strength at a heat treatment temperature of not more than 800℃. The production difficulty of transparent spinel microcrystalline glass is greatly reduced, the mass production possibility is higher, and it meets the development needs of energy saving and carbon reduction in the industry.

[0320] Finally, it should be pointed out that the above preferred embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present application.

Claims

1. A strengthened microcrystalline glass characterized in that, The reinforced glass-ceramic comprises a compressive stress layer and a tensile stress layer. The tensile stress layer of the reinforced glass-ceramic contains, in mol%, the following proportions of oxides: SiO2 38.00–48.00%, Al2O3 25.50–30.00%, ZrO2 3.00–5.00%, MgO 5.00–8.00%, ZnO 8.00–14.00%, Na2O 7.20–14.00%, B2O3 3.00–8.00%, K2O 0–2.00%, and Y2O3 0–1.00%. The tensile stress layer of the reinforced microcrystalline glass is essentially free of Li2O, with Li2O content less than 0.01% in mol%. Based on the molar percentage of each oxide in the composition of the tensile stress layer of the reinforced glass-ceramic, the composition of the tensile stress layer of the reinforced glass-ceramic satisfies: The value of X is calculated based on the following formula, where X ranges from 30.00% to 50.00%. X=2.1×(Al2O3-MgO-ZnO) / (SiO2+Al2O3-MgO-ZnO+Na2O+K2O+B2O3), and, The value of Y is calculated based on the following formula, where Y is between 60.00% and 80.00%. Y=(2.7×Na2O+1.8×(Al2O3-MgO-ZnO)) / (SiO2+Al2O3-MgO-ZnO+Na2O+K2O+B2O3).

2. The strengthened microcrystalline glass of claim 1, wherein, The tensile stress layer of the reinforced microcrystalline glass contains the following oxides in mol% proportions: SiO2 38.00–44.00%, Al2O3 25.50–30.00%, ZrO2 3.00–4.00%, MgO 5.00–7.00%, ZnO 8.00–11.50%, Na2O 7.20–13.00%, B2O3 3.00–7.00%, K2O 0–2.00%, and Y2O3 0–1.00%.

3. The strengthened microcrystalline glass of claim 1 or 2, wherein, The composition of the tensile stress layer of the reinforced glass-ceramic, expressed as a molar percentage of each oxide, satisfies the following: A = 0.65 × Al₂O₃ + 3.5 × ZrO₂ - 0.8 × Na₂O - 2.5 × B₂O₃, where the value of A is less than or equal to 0.18; And / or, B = 3.8 × Na₂O + B₂O₃ + 4.5 × MgO + 6.0 × ZnO - 0.4 × Al₂O₃ - SiO₂, where the value of B is less than or equal to 0.80; And / or, Al2O3-MgO-ZnO=8.00~15.00%.

4. The strengthened microcrystalline glass of claim 3, wherein, The composition of the tensile stress layer of the reinforced glass-ceramic, expressed as a molar percentage of each oxide, satisfies the following: The value of A is 0.05 to 0.15; And / or, the value of B is 0.60 to 0.

78.

5. The strengthened microcrystalline glass of claim 1 or 2, wherein, The composition of the tensile stress layer of the reinforced glass-ceramic, expressed as a molar percentage of each oxide, satisfies the following: the X value is 34.00 to 46.00%, and / or the Y value is 60.00 to 75.00%.

6. The strengthened microcrystalline glass of claim 3, wherein, The composition of the tensile stress layer of the strengthened glass-ceramics satisfies: the X value is 34.00-46.00%, and / or the Y value is 60.00-75.00%, in terms of content of each oxide in mol%.

7. The strengthened microcrystalline glass of claim 1 or 2, wherein, The composition of the tensile stress layer of the strengthened glass-ceramics is substantially free of BaO, with BaO less than 0.01% in mol%. And / or, the composition of the tensile stress layer of the strengthened glass-ceramics is substantially free of TiO2, with TiO2 less than 0.01% in mol%.

8. The strengthened microcrystalline glass of claim 3, wherein, The composition of the tensile stress layer of the strengthened glass-ceramics is substantially free of BaO, with BaO less than 0.01% in mol%. And / or, the composition of the tensile stress layer of the strengthened glass-ceramics is substantially free of TiO2, with TiO2 less than 0.01% in mol%.

9. The strengthened microcrystalline glass of claim 5, wherein, The composition of the tensile stress layer of the strengthened glass-ceramics is substantially free of BaO, with BaO less than 0.01% in mol%. And / or, the composition of the tensile stress layer of the strengthened glass-ceramics is substantially free of TiO2, with TiO2 less than 0.01% in mol%.

10. The strengthened microcrystalline glass of claim 1, wherein, The composition of the tensile stress layer of the strengthened glass-ceramics satisfies: The mol% of SiO2 is 38.00-44.00%; And / or, the mol% of Na2O is 7.20-12.00%; And / or, the mol% of Al2O3 is 25.50-28.00%; And / or, the mol% of MgO is 5.00-6.50%; And / or, the mol% of ZnO is 8.00-10.50%; And / or, the mol% of B2O3 is 3.00-6.50%.

11. The strengthened microcrystalline glass of claim 1 or 2, wherein, The main crystal phase of the strengthened glass-ceramics is (Zn, Mg) Al2O4, and the secondary crystal phase includes tetragonal zirconia.

12. The strengthened glass ceramic of claim 3, wherein, The main crystal phase of the strengthened glass-ceramics is (Zn, Mg) Al2O4, and the secondary crystal phase includes tetragonal zirconia.

13. The strengthened glass ceramic of claim 5, wherein, The main crystal phase of the strengthened glass-ceramics is (Zn, Mg) Al2O4, and the secondary crystal phase includes tetragonal zirconia.

14. The strengthened microcrystalline glass of claim 7, wherein, The main crystal phase of the strengthened glass-ceramics is (Zn, Mg) Al2O4, and the secondary crystal phase includes tetragonal zirconia.

15. The strengthened microcrystalline glass of claim 10, wherein, The main crystal phase of the strengthened glass-ceramics is (Zn, Mg) Al2O4, and the secondary crystal phase includes tetragonal zirconia.

16. The strengthened glass ceramic of claim 1 or 2, wherein, The crystallinity of the strengthened glass-ceramics is ≥20.00wt%; and / or, The average grain size in the strengthened glass-ceramics is ≤15.0nm.

17. The strengthened microcrystalline glass of claim 16, wherein, The crystallinity of the strengthened glass-ceramics is 20.00-50.00wt%; and / or, The average grain size in the strengthened glass-ceramics is 1.0-15.0nm.

18. The strengthened microcrystalline glass of claim 16, wherein, The crystallinity of the strengthened glass-ceramics is 30.00-50.00wt%; and / or, The average grain size in the strengthened glass-ceramics is 1.0-10.0nm.

19. The strengthened microcrystalline glass of claim 16, wherein, The crystallinity of the strengthened glass-ceramics is 35.00-45.00wt%; and / or, The average grain size in the strengthened glass-ceramics is 4.5-8.0nm.

20. The strengthened glass ceramic of claim 3, wherein, The crystallinity of the strengthened glass-ceramics is ≥20.00wt%; and / or, The average grain size in the strengthened glass-ceramics is less than or equal to 15.0 nm.

21. The strengthened microcrystalline glass of claim 5, wherein, The crystallinity of the strengthened glass-ceramics is greater than or equal to 20.00 wt%; and / or, The average grain size in the strengthened glass-ceramics is less than or equal to 15.0 nm.

22. The strengthened microcrystalline glass of claim 7, wherein, The crystallinity of the strengthened glass-ceramics is greater than or equal to 20.00 wt%; and / or, The average grain size in the strengthened glass-ceramics is less than or equal to 15.0 nm.

23. The strengthened microcrystalline glass of claim 10, wherein, The crystallinity of the strengthened glass-ceramics is greater than or equal to 20.00 wt%; and / or, The average grain size in the strengthened glass-ceramics is less than or equal to 15.0 nm.

24. The strengthened microcrystalline glass of claim 11, wherein, The crystallinity of the strengthened glass-ceramics is greater than or equal to 20.00 wt%; and / or, The average grain size in the strengthened glass-ceramics is less than or equal to 15.0 nm.

25. The strengthened glass ceramic of claim 1 or 2, wherein, The strengthened glass-ceramics satisfies: a compressive stress layer depth DOL_0 is greater than or equal to 0.13t, t is the thickness of the strengthened glass-ceramics.

26. The strengthened microcrystalline glass of claim 25, wherein, The strengthened glass-ceramics satisfies: 0.22t is greater than or equal to DOL_0 which is greater than or equal to 0.15t.

27. The strengthened glass ceramic of claim 3, wherein, The strengthened glass-ceramics satisfies: a compressive stress layer depth DOL_0 is greater than or equal to 0.13t, t is the thickness of the strengthened glass-ceramics.

28. The strengthened glass ceramic of claim 5, wherein, The strengthened glass-ceramics satisfies: a compressive stress layer depth DOL_0 is greater than or equal to 0.13t, t is the thickness of the strengthened glass-ceramics.

29. The strengthened glass ceramic of claim 7, wherein, The strengthened glass-ceramics satisfies: a compressive stress layer depth DOL_0 is greater than or equal to 0.13t, t is the thickness of the strengthened glass-ceramics.

30. The strengthened glass ceramic of claim 10, wherein, The strengthened glass-ceramics satisfies: a compressive stress layer depth DOL_0 is greater than or equal to 0.13t, t is the thickness of the strengthened glass-ceramics.

31. The strengthened microcrystalline glass of claim 11, wherein, The strengthened glass-ceramics satisfies: a compressive stress layer depth DOL_0 is greater than or equal to 0.13t, t is the thickness of the strengthened glass-ceramics.

32. The strengthened microcrystalline glass of claim 16, wherein, The strengthened glass-ceramics satisfies: a compressive stress layer depth DOL_0 is greater than or equal to 0.13t, t is the thickness of the strengthened glass-ceramics.

33. The strengthened glass ceramic of claim 1 or 2, wherein, The strengthened glass-ceramics satisfies: |CT_CV| is greater than or equal to 80MPa.

34. The strengthened microcrystalline glass of claim 33, wherein, The strengthened glass-ceramics satisfies: 300MPa is greater than or equal to |CT_CV| which is greater than or equal to 80MPa.

35. The strengthened microcrystalline glass of claim 33, wherein, The strengthened glass-ceramics satisfies: |CT_CV| is 89.07-146.38MPa.

36. The strengthened glass ceramic of claim 3, wherein, The strengthened glass-ceramics satisfies: |CT_CV| is greater than or equal to 80MPa.

37. The strengthened glass ceramic of claim 5, wherein, The strengthened glass-ceramics satisfies: |CT_CV| is greater than or equal to 80MPa.

38. The strengthened glass ceramic of claim 7, wherein, The strengthened glass-ceramics satisfies: |CT_CV| is greater than or equal to 80MPa.

39. The strengthened glass ceramic of claim 10, wherein, The strengthened glass-ceramics satisfies: |CT_CV| is greater than or equal to 80MPa.

40. The strengthened glass ceramic of claim 11, wherein, The strengthened glass-ceramics satisfies: |CT_CV| is greater than or equal to 80MPa.

41. The strengthened microcrystalline glass of claim 16, wherein, The strengthened glass-ceramics satisfies: |CT_CV| is greater than or equal to 80MPa.

42. The strengthened glass ceramic of claim 25, wherein, The strengthened glass-ceramics satisfies: |CT_AV| is greater than or equal to 70MPa.

43. The strengthened glass ceramic of claim 1 or 2, wherein, The strengthened glass-ceramics satisfies: 200MPa is greater than or equal to |CT_AV| which is greater than or equal to 70MPa.

44. The strengthened microcrystalline glass of claim 43, wherein, The strengthened glass-ceramics satisfies: |CT_AV| is 73.38-125.91MPa.

45. The strengthened microcrystalline glass of claim 43, wherein, The strengthened glass-ceramics satisfies: |CT_AV| is greater than or equal to 70MPa.

46. The strengthened glass ceramic of claim 3, wherein, The strengthened glass-ceramics satisfies: |CT_AV| is greater than or equal to 70MPa.

47. The strengthened glass ceramic of claim 5, wherein, The strengthened glass-ceramics satisfies: |CT_AV| is greater than or equal to 70MPa.

48. The strengthened glass ceramic of claim 7, wherein, ​ 49. The strengthened glass ceramic of claim 10, wherein, The strengthened microcrystalline glass satisfies: |CT_AV|≥70MPa.

50. The strengthened glass ceramic of claim 11, wherein, The strengthened microcrystalline glass satisfies: |CT_AV|≥70MPa.

51. The strengthened glass ceramic of claim 16, wherein, The strengthened microcrystalline glass satisfies: |CT_AV|≥70MPa.

52. The strengthened glass ceramic of claim 25, wherein The strengthened microcrystalline glass satisfies: |CT_AV|≥70MPa.

53. The strengthened glass ceramic of claim 1 or 2, wherein The strengthened microcrystalline glass satisfies: CS_50≥100MPa.

54. The strengthened microcrystalline glass of claim 53, wherein, The strengthened microcrystalline glass satisfies: 500MPa≥CS_50≥140MPa.

55. The strengthened microcrystalline glass of claim 53, wherein, The strengthened microcrystalline glass satisfies: CS_50 is 148.02-337.69MPa.

56. The strengthened glass ceramic of claim 3, wherein, The strengthened microcrystalline glass satisfies: CS_50≥100MPa.

57. The strengthened glass ceramic of Claim 5, wherein, The strengthened microcrystalline glass satisfies: CS_50≥100MPa.

58. The strengthened glass ceramic of claim 7, wherein, The strengthened microcrystalline glass satisfies: CS_50≥100MPa.

59. The strengthened glass ceramic of claim 10, wherein, The strengthened microcrystalline glass satisfies: CS_50≥100MPa.

60. The strengthened glass ceramic of claim 11, wherein, The strengthened microcrystalline glass satisfies: CS_50≥100MPa.

61. The strengthened glass ceramic of Claim 16, wherein, The strengthened microcrystalline glass satisfies: CS_50≥100MPa.

62. The strengthened glass ceramic of Claim 25, wherein The strengthened microcrystalline glass satisfies: CS_50≥100MPa.

63. The strengthened glass ceramic of claim 1 or 2, wherein The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

64. The strengthened microcrystalline glass of claim 63, wherein, The strengthened microcrystalline glass satisfies: CT_LD is 45000MPa / mm-85000MPa / mm.

65. The strengthened microcrystalline glass of Claim 63, wherein, The strengthened microcrystalline glass satisfies: CT_LD is 48000MPa / mm-85000MPa / mm.

66. The strengthened microcrystalline glass of claim 63, wherein, The strengthened microcrystalline glass satisfies: CT_LD is 49620-80192MPa / mm.

67. The strengthened glass ceramic of Claim 3, wherein The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

68. The strengthened glass ceramic of Claim 5, wherein The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

69. The strengthened glass ceramic of claim 7, wherein, The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

70. The strengthened glass ceramic of Claim 10, wherein The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

71. The strengthened glass ceramic of Claim 11, wherein The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

72. The strengthened glass ceramic of Claim 16, wherein The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

73. The strengthened glass ceramic of Claim 25, wherein The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

74. The strengthened glass ceramic of Claim 33, wherein The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

75. The strengthened glass ceramic of Claim 43, wherein The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

76. The strengthened glass ceramic of Claim 53, wherein, The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm.

77. The strengthened glass ceramic of claim 1 or 2, wherein The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00wt%.

78. The strengthened microcrystalline glass of claim 77, wherein, The surface K2O concentration of the strengthened microcrystalline glass is 9.00-16.00wt%.

79. The strengthened microcrystalline glass of claim 77, wherein, The surface K2O concentration of the strengthened microcrystalline glass is 9.16-15.21 wt%.

80. The strengthened glass ceramic of claim 3, wherein, The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

81. The strengthened glass ceramic of Claim 5, wherein, The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

82. The strengthened glass ceramic of Claim 7, wherein The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

83. The strengthened glass ceramic of Claim 10, wherein The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

84. The strengthened glass ceramic of Claim 11, wherein, The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

85. The strengthened glass ceramic of Claim 16, wherein The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

86. The strengthened glass ceramic of Claim 25, wherein The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

87. The strengthened glass ceramic of Claim 33, wherein The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

88. The strengthened glass ceramic of Claim 43, wherein, The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

89. The strengthened glass ceramic of Claim 53, wherein, The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

90. The strengthened glass ceramic of Claim 63, wherein The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

91. The strengthened glass ceramic of claim 1 or 2, wherein The surface K2O concentration of the strengthened microcrystalline glass is ≥9.00 wt%.

92. The strengthened microcrystalline glass of claim 91, wherein, The strengthened microcrystalline glass is transparent in the visible light range.

93. The strengthened microcrystalline glass of claim 91, wherein, The transmittance of the strengthened microcrystalline glass is greater than or equal to 85% for light of a wavelength of 550 nm at a thickness of 0.7 mm; and / or the absolute value of the optical b value of the strengthened microcrystalline glass is 0.20-1.50 at a thickness of 0.7 mm.

94. The strengthened glass ceramic of Claim 3, wherein, The transmittance of the strengthened microcrystalline glass is greater than or equal to 89% for light of a wavelength of 550 nm at a thickness of 0.7 mm; and / or the absolute value of the optical b value of the strengthened microcrystalline glass is 0.50-1.20 at a thickness of 0.7 mm.

95. The strengthened glass ceramic of Claim 5, wherein, The strengthened microcrystalline glass is transparent in the visible light range.

96. The strengthened glass ceramic of Claim 7, wherein, The strengthened microcrystalline glass is transparent in the visible light range.

97. The strengthened glass ceramic of Claim 10, wherein The strengthened microcrystalline glass is transparent in the visible light range.

98. The strengthened glass ceramic of Claim 11, wherein The strengthened microcrystalline glass is transparent in the visible light range.

99. The strengthened glass ceramic of Claim 16, wherein The strengthened microcrystalline glass is transparent in the visible light range.

100. The strengthened glass ceramic of claim 25, wherein, The strengthened microcrystalline glass is transparent in the visible light range.

101. The strengthened glass ceramic of Claim 33, wherein The strengthened microcrystalline glass is transparent in the visible light range.

102. The strengthened glass ceramic of Claim 43, wherein The strengthened microcrystalline glass is transparent in the visible light range.

103. The strengthened glass ceramic of Claim 53, wherein, The strengthened microcrystalline glass is transparent in the visible light range.

104. The strengthened glass ceramic of Claim 63, wherein The strengthened microcrystalline glass is transparent in the visible light range.

105. The strengthened glass ceramic of Claim 77, wherein, The strengthened microcrystalline glass is transparent in the visible light range.

106. The strengthened glass ceramic of claim 1 or 2, wherein, The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

107. The strengthened glass ceramic of Claim 3, wherein The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

108. The strengthened glass ceramic of Claim 5, wherein The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

109. The strengthened glass ceramic of Claim 7, wherein The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

110. The strengthened glass ceramic of Claim 10, wherein The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

111. The strengthened glass ceramic of claim 11, wherein, The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

112. The strengthened glass ceramic of claim 16, wherein The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

113. The strengthened glass ceramic of Claim 25, wherein The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

114. The strengthened glass ceramic of Claim 33, wherein The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

115. The strengthened glass ceramic of Claim 43, wherein, The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

116. The strengthened glass ceramic of Claim 53, wherein, The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

117. The strengthened glass ceramic of Claim 63, wherein The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

118. The strengthened glass ceramic of Claim 77, wherein The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

119. The strengthened glass ceramic of Claim 91, wherein, The strengthened microcrystalline glass has a Vickers hardness of 700 to 900 kgf / mm 2 .

120. The strengthened glass ceramic of claim 1 or 2, wherein, The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

121. The strengthened glass ceramic of claim 120, wherein, The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.20 MPa.m 1 / 2 .

122. The strengthened glass ceramic of claim 120, wherein, The reinforced microcrystalline glass has a fracture toughness greater than or equal to 1.50 MPa.m 1 / 2 .

123. The strengthened glass ceramic of Claim 3, wherein, The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

124. The strengthened glass ceramic of Claim 5, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

125. The strengthened glass ceramic of Claim 7, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

126. The strengthened glass ceramic of Claim 10, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

127. The strengthened glass ceramic of Claim 11, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

128. The strengthened glass ceramic of Claim 16, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

129. The strengthened glass ceramic of Claim 25, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

130. The strengthened glass ceramic of Claim 33, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

131. The strengthened glass ceramic of Claim 43, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

132. The strengthened glass ceramic of Claim 53, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

133. The strengthened glass ceramic of Claim 63, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

134. The strengthened glass ceramic of Claim 77, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

135. The strengthened glass ceramic of Claim 91, wherein, The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

136. The strengthened glass ceramic of Claim 106, wherein The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 .

137. The strengthened glass ceramic of claim 1 or 2, wherein The strengthened microcrystalline glass is transparent in the visible light range.

138. The strengthened microcrystalline glass of claim 137, wherein, The strengthened microcrystalline glass is transparent in the visible light range.

139. The strengthened glass ceramic of Claim 137, wherein, The strengthened microcrystalline glass is transparent in the visible light range.

140. The strengthened glass ceramic of Claim 3, wherein The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa.

141. The strengthened glass ceramic of Claim 5, wherein The Young's modulus of the strengthened microcrystalline glass is ≥110 GPa.

142. The strengthened glass ceramic of Claim 7, wherein The Young's modulus of the strengthened microcrystalline glass satisfies: 114 GPa≤Young's modulus≤140 GPa.

143. The strengthened glass ceramic of Claim 10, wherein The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa.

144. The strengthened glass ceramic of Claim 11, wherein The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa.

145. The strengthened glass ceramic of Claim 16, wherein The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa.

146. The strengthened glass ceramic of Claim 25, wherein The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa.

147. The strengthened glass ceramic of Claim 33, wherein The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa. The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa. The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa. The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa.

148. The strengthened glass ceramic of Claim 43, wherein The reinforced glass ceramic has a Young's modulus of ≥ 100 GPa.

149. The strengthened glass ceramic of Claim 53, wherein, The reinforced glass ceramic has a Young's modulus of ≥ 100 GPa.

150. The strengthened glass ceramic of Claim 63, wherein The reinforced glass ceramic has a Young's modulus of ≥ 100 GPa.

151. The strengthened glass ceramic of Claim 77, wherein The reinforced glass ceramic has a Young's modulus of ≥ 100 GPa.

152. The strengthened glass ceramic of Claim 91, wherein The reinforced glass ceramic has a Young's modulus of ≥ 100 GPa.

153. The strengthened glass ceramic of Claim 106, wherein, The reinforced glass ceramic has a Young's modulus of ≥ 100 GPa.

154. The strengthened glass ceramic of Claim 120, wherein, The reinforced glass ceramic has a Young's modulus of ≥ 100 GPa.

155. The strengthened glass ceramic of claim 1 or 2, wherein, The reinforced glass ceramic has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

156. The strengthened microcrystalline glass of claim 155, wherein, The reinforced glass ceramic has an average sandpaper drop height of greater than or equal to 1.80 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

157. The strengthened glass ceramic of claim 155, wherein, The reinforced glass ceramic has an average sandpaper drop height of 1.80-2.50 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

158. The strengthened glass ceramic of claim 155, wherein, The reinforced glass ceramic has an average sandpaper drop height of 2.00-2.50 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

159. The strengthened glass ceramic of Claim 3, wherein The reinforced glass ceramic has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

160. The strengthened glass ceramic of Claim 5, wherein, The reinforced glass ceramic has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

161. The strengthened glass ceramic of Claim 7, wherein The reinforced glass ceramic has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

162. The strengthened glass ceramic of Claim 10, wherein The reinforced glass ceramic has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

163. The strengthened glass ceramic of claim 11, wherein, The reinforced glass ceramic has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

164. The strengthened glass ceramic of Claim 16, wherein The reinforced glass ceramic has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

165. The strengthened glass ceramic of Claim 25, wherein The reinforced glass ceramic has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

166. The strengthened glass ceramic of Claim 33, wherein The reinforced glass ceramic has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

167. The strengthened glass ceramic of Claim 43, wherein ​ 168. The strengthened glass ceramic of Claim 53, wherein The strengthened microcrystalline glass has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

169. The strengthened glass ceramic of Claim 63, wherein The strengthened microcrystalline glass has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

170. The strengthened glass ceramic of Claim 77, wherein The strengthened microcrystalline glass has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

171. The strengthened glass ceramic of Claim 91, wherein The strengthened microcrystalline glass has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

172. The strengthened glass ceramic of Claim 106, wherein The strengthened microcrystalline glass has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

173. The strengthened glass ceramic of Claim 120, wherein The strengthened microcrystalline glass has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

174. The strengthened glass ceramic of Claim 137, wherein The strengthened microcrystalline glass has an average sandpaper drop height of greater than 1.5 m when subjected to a sandpaper drop test using 120 grit sandpaper at a thickness of 0.7 mm.

175. The strengthened glass ceramic of claim 1 or 2, wherein The strengthened microcrystalline glass has a pass rate of 50% or greater when subjected to a 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm.

176. The strengthened microcrystalline glass of claim 175, wherein, The strengthened microcrystalline glass has a pass rate of 60% or greater when subjected to a 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm.

177. The strengthened microcrystalline glass of claim 175, wherein, The strengthened microcrystalline glass has a pass rate of 70% or greater when subjected to a 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm.

178. The strengthened glass ceramic of claim 175, wherein, The strengthened microcrystalline glass has a pass rate of 60% to 100% when subjected to a 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm.

179. The strengthened glass ceramic of Claim 3, wherein The strengthened microcrystalline glass has a pass rate of 50% or greater when subjected to a 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm.

180. The strengthened glass ceramic of Claim 5, wherein The strengthened microcrystalline glass has a pass rate of 50% or greater when subjected to a 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm.

181. The strengthened glass ceramic of Claim 7, wherein The strengthened microcrystalline glass has a pass rate of 50% or greater when subjected to a 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm.

182. The strengthened glass ceramic of claim 10, wherein The strengthened microcrystalline glass has a pass rate of 50% or greater when subjected to a 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm.

183. The strengthened glass ceramic of claim 11, wherein, The strengthened microcrystalline glass has a pass rate of 50% or greater when subjected to a 2.5 m drop test using 120 grit sandpaper at a thickness of 0.7 mm.

184. The strengthened glass ceramic of Claim 16, wherein ​ 185. The strengthened glass ceramic of Claim 25, wherein The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

186. The strengthened glass ceramic of Claim 33, wherein The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

187. The strengthened glass ceramic of Claim 43, wherein The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

188. The strengthened glass ceramic of Claim 53, wherein The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

189. The strengthened glass ceramic of Claim 63, wherein The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

190. The strengthened glass ceramic of Claim 77, wherein The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

191. The strengthened glass ceramic of Claim 91, wherein The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

192. The strengthened glass ceramic of Claim 106, wherein The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

193. The strengthened glass ceramic of claim 120, wherein, The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

194. The strengthened glass ceramic of Claim 137, wherein The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

195. The strengthened glass ceramic of Claim 155, wherein, The strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120 mesh sandpaper at a thickness of 0.7 mm, and the pass rate of the strengthened microcrystalline glass is greater than or equal to 50%.

196. The strengthened glass ceramic of claim 1 or 2, wherein, The thickness t of the strengthened microcrystalline glass is 0.2-5.0 mm.

197. The strengthened microcrystalline glass of claim 196, wherein, The thickness t of the strengthened microcrystalline glass is 0.3-2.0 mm.

198. The strengthened microcrystalline glass of claim 196, wherein, The thickness t of the strengthened microcrystalline glass is 0.4-1.5 mm.

199. The strengthened glass ceramic of Claim 1, wherein The molar percentage of SiO2 is 43.27%, 38.64%, 40.26%, 41.28%, 41.23%, 41.54%, 42.12%, 38.47%, 39.42%, or 40.66%; and / or, The molar percentage of Al2O3 is 26.33%, 27.89%, 25.91%, 26.89%, 26.54%, 27.26%, 27.1%, 27.77%, 29.85%, or 26.17; and / or, The molar percentage of ZrO2 is 3.46%, 3.31%, 3.84%, 3.42%, 3.37%, 3.44%, 3.48%, or 3.33%; and / or, The molar percentage of MgO is 5.78%, 5.52%, 5.49%, 5.7%, 5.63%, 5.75%, 6.11%, 5.71%, or 5.55%; and / or, the molar percentage of ZnO is 9.92%, 9.48%, 9.42%, 9.79%, 9.66%, 9.86%, 10.33%, 9.81% or 9.52%; and / or, the molar percentage of Na2O is 7.39%, 9.65%, 9.6%, 8.63%, 9.83%, 7.34%, 7.51%, 7.23% or 11.08%; and / or, the molar percentage of B2O3 is 3.85%, 5.51%, 5.48%, 3.79%, 3.74%, 3.82%, 6.33%, 4.56% or 3.69%.

200. The strengthened glass ceramic of Claim 1, wherein the value of X is 30.00%, 32.00%, 34.00%, 36.00%, 38.00%, 40.00%, 42.00%, 44.00%, 46.00%, 48.00% or 50.00%, and / or, the value of Y is 60.00%, 62.00%, 64.00%, 66.00%, 68.00%, 70.00%, 72.00%, 74.00%, 76.00%, 78.00% or 80.00%.

201. The strengthened glass ceramic of Claim 3, wherein the value of A is 0.05, 0.07, 0.09, 0.11, 0.13, 0.15, 0.17 or 0.18; and / or, the value of B is 0.60, 0.62, 0.64, 0.66, 0.68, 0.70, 0.72, 0.74, 0.76, 0.78 or 0.80; and / or, the value of Al2O3-MgO-ZnO is 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% or 15.00%.

202. An electronic terminal, characterized in that The electronic terminal comprises the strengthened glass ceramic according to any one of claims 1-201.

203. The electronic terminal of claim 202, wherein, The electronic terminal comprises a mobile phone display screen, a tablet computer display screen, a palm game machine, a portable digital device, a vehicle central control screen, an electronic whiteboard glass, a smart home touch screen.

204. Use of the strengthened glass ceramic according to any one of claims 1-201 in a mobile phone display screen, a tablet computer display screen, a palm game machine, an electronic terminal, a portable digital device, a vehicle central control screen, an electronic whiteboard glass, a smart home touch screen, a vehicle windshield, an aircraft windshield or a ship windshield.

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