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

Abstract

The invention relates to the technical field of glass ceramics, in particular to lithium-free transparent spinel glass ceramics as well as a preparation method and application thereof. The lithium-free transparent spinel glass ceramic is obtained by carrying out heat treatment on base material glass, and spinel crystal is a main crystal phase; the composition of the glass ceramic comprises the following oxides in terms of mol%: 28.00%-48.00% of SiO2, 25.50%-30.00% of Al2O3, 3.00%-5.00% of ZrO2, 5.00%-8.00% of MgO, 8.00%-14.00% of ZnO, 7.20%-14.00% of Na2O, 3.00%-8.00% of B2O3, 0-2.00% of K2O and 0-1.00% of Y2O3, and the glass ceramic basically contains no Li2O, and the glass ceramic does not adopt lithium with high cost, and can obtain excellent surface and deep stress characteristics and excellent drop impact resistance through chemical strengthening.

Description

[0001] This invention patent application is a divisional application of the invention patent application with application number 202211738867.8, application date December 30, 2022, and invention name "A lithium-free transparent spinel microcrystalline glass, its preparation method and application". Technical Field

[0002] The present invention relates to the technical field of glass-ceramics, and in particular to a chemically strengthened lithium-free transparent spinel glass-ceramics, and a preparation method and application thereof. Background Art

[0003] As electronic devices become thinner and lighter, the performance requirements for cover glass are gradually increasing. For electronic cover glass, it is necessary to have excellent surface stress characteristics and excellent deep stress characteristics to obtain high mechanical properties. Among them, excellent deep stress characteristics are a necessary condition for cover glass to obtain excellent impact resistance, such as excellent drop resistance.

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

[0005] In order to make spinel glass-ceramics meet the requirements of screen cover, researchers tried to chemically strengthen and toughen it. The main method is to first introduce lithium oxide and / or sodium oxide into the substrate glass, and then achieve chemical strengthening by exchanging lithium ions in the substrate glass with sodium ions in the salt bath, and / or exchanging sodium ions in the substrate glass with potassium ions in the salt bath.

[0006] After research, the inventors found that there are many disadvantages in using lithium ions to achieve chemical strengthening and toughening. First, the radius difference between Li ions and Na ions is about 22pm, and the radius difference between Na ions and K ions is about 40pm. The stress performance is caused by the "crowding" effect formed by ion exchange. Therefore, under the same exchange amount, the stress performance generated by the exchange of Li ions and Na ions is far inferior to the stress performance generated by the exchange of Na ions and K ions. Second, if you want to rely on the exchange of Li ions and Na ions to obtain high stress performance, you need to add a higher content of lithium oxide to the substrate glass. Li2O is expensive, and the large-scale use of lithium oxide will cause the cost of glass to be too high. Third, if there is a large amount of Li in the substrate glass, it is easy to cause the substrate glass to precipitate quartz, quartz solid solution, etc., which will affect the transmittance of microcrystalline glass when it is heat-treated to obtain microcrystalline glass, resulting in the optical properties of microcrystalline glass to deteriorate.

[0007] As for the scheme of chemical strengthening and toughening by sodium ions in the prior art, the inventors found that its deep stress characteristics are poor and the effect of anti-drop impact is not ideal. For example, the invention application CN111908793A discloses a glass ceramic with a 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%, wherein a large amount of Na2O is added. However, after chemical strengthening, the glass ceramic can only obtain a compressive stress layer depth of no more than 40 microns, and the deep stress characteristics are poor. After the drop impact, it is very easy to break, and it is difficult to achieve an excellent anti-drop impact effect.

[0008] In addition, the inventors also found that the heat treatment temperature required for the preparation of existing transparent spinel glass-ceramics, mainly the crystallization temperature, is usually 900°C or even higher, which greatly limits the mass production of spinel glass-ceramics and makes it impossible to successfully mass-produce ordinary roller kilns. Summary of the invention

[0009] Based on the above research, in order to improve economic benefits and avoid the drawbacks of using lithium ions to achieve chemical strengthening and toughening in spinel glass-ceramics, the inventors came up with the idea of ​​using sodium ions instead of lithium oxide to achieve chemical strengthening and toughening of spinel glass-ceramics.

[0010] However, the transparent spinel glass-ceramics in the prior art that is chemically strengthened and toughened only by sodium ions has poor anti-drop performance and cannot meet the drop impact performance requirements of the screen cover; and the existing transparent spinel glass-ceramics has a crystallization temperature higher than 900°C, which affects the mass production performance.

[0011] After in-depth research, the inventors found that the existing spinel glass-ceramics containing only Na cannot reach a higher stress depth after chemical strengthening, has poor deep stress characteristics and poor drop resistance, mainly because the microstructure of the existing spinel glass-ceramics limits the depth of Na ions entering the interior of the glass, affecting the depth at which Na ions and K ions can be exchanged. The volume of [AlO4] tetrahedron is larger than that of [SiO4]. In theory, 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 increase in Al2O3 will greatly increase the difficulty of melting the substrate glass, especially in the absence of Li2O fluxing. Because the fluxing effect of Na2O is not as good as Li2O, but the melting difficulty of Al2O3 is greater than that of SiO2. By introducing a large amount of Na2O to exert the fluxing effect, crystallization will be uncontrollable, and the substrate glass will be ceramicized during the molding or annealing process.

[0012] In this regard, the inventors continuously adjusted the formula, adjusted the amount of each oxide in the formula and the relationship between the amounts of each oxide, optimized the glass formula, took into account the melting effect, stress effect, optical effect and mechanical properties, and finally developed a lithium-free transparent spinel glass-ceramic with a specific structure, good overall uniformity and high intrinsic strength. The glass-ceramic not only has a lower preparation cost than the existing lithium-containing spinel glass-ceramic, excellent optical properties, and high intrinsic strength, but also can be obtained by chemical strengthening. Strengthened glass-ceramic with excellent surface stress characteristics and deep stress characteristics, thereby making the strengthened glass-ceramic have excellent mechanical properties, such as excellent drop impact resistance. At the same time, the substrate glass corresponding to the optimized glass formula of the present invention can obtain a transparent glass-ceramic with a main crystal phase of zinc-magnesium spinel solid solution, excellent optical properties and high intrinsic strength when the heat treatment temperature does not exceed 800°C. Compared with the prior art, the optimized spinel glass-ceramics formula of the present invention can significantly reduce the heat treatment temperature required for preparing the target glass-ceramics, which meets the development needs of the industry for energy conservation and carbon reduction, improves the mass producibility of transparent spinel glass-ceramics, and ensures the excellent optical properties and high intrinsic strength of the glass-ceramics.

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

[0014] In one aspect, the present invention provides a lithium-free transparent spinel glass-ceramics, wherein the lithium-free transparent spinel glass-ceramics is prepared by heat treatment of a substrate glass, wherein the lithium-free transparent spinel glass-ceramics contains spinel crystals, and the spinel crystals are the main crystalline phase of the glass-ceramics;

[0015] The composition of the lithium-free transparent spinel 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%;

[0016] Wherein, the lithium-free transparent spinel glass-ceramics substantially does not contain Li2O, and in terms of mol%, the Li2O content is less than 0.01%.

[0017] Preferably, the composition of the lithium-free transparent spinel glass-ceramics contains the following proportions of oxides in mol%: SiO2 38.00-44.00%, Al2O3 25.50-30.00%, ZrO2 3.00-4.00%, MgO5.00-7.00%, ZnO 8.00-12.00%, Na2O 7.20-13.00%, B2O3 3.00-7.00%, K2O0-2.00% and Y2O3 0-1.00%.

[0018] Preferably, the composition of the lithium-free transparent spinel glass-ceramics satisfies the following conditions, based on the content of each oxide in the composition expressed as a molar percentage:

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

[0020] (1)A=0.65×A l2O3+3.5×ZrO2-0.8×Na2O-2.5×B2O 3；

[0021] and / or,

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

[0023] (2)B=3.8×Na2O+B2O3+4.5×MgO+6.0×ZnO-0.4×A l2O3-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 the components 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 the following conditions, based on the content of each oxide in the composition expressed as a molar percentage:

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

[0032] (3)X=2.1×(A l2O3-MgO-ZnO) / (SiO2+A l2O3-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 to 80.00%, preferably 60.00 to 75.00%.

[0035] (4) Y=(2.7×Na2O+1.8×(A l2O3-MgO-ZnO)) / (SiO2+A l2O3-MgO-ZnO+Na2O+K2O+B2O3).

[0036] Preferably, the spinel crystal is (Zn, Mg)Al2O4; and / or, the lithium-free transparent spinel glass-ceramics also includes a secondary crystalline 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, in the lithium-free transparent spinel glass-ceramics, the average grain size is ≤15.0 nm, preferably 1.0 to 15.0 nm, more preferably 1.0 to 10.0 nm, and even more preferably 4.5 to 8.0 nm.

[0039] Preferably, at a thickness of 0.7 mm, for light of a wavelength of 550 nm, the transmittance of the lithium-free transparent spinel glass-ceramics is greater than or equal to 85%, and 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 ≥100 GPa, preferably the Young's modulus is ≥110 GPa, and more preferably 114 GPa≤Young's modulus≤140 GPa.

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

[0042] Preferably, the lithium-free transparent spinel glass-ceramics contains substantially no BaO, and the BaO content is less than 0.01% in mol%;

[0043] And / or, the lithium-free transparent spinel glass-ceramics does not substantially contain TiO2, and the TiO2 content is less than 0.01% in mol%.

[0044] On the other hand, the present invention also provides a method for preparing the above-mentioned lithium-free transparent spinel glass-ceramics, comprising the following steps: heat-treating a substrate glass to form a 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 composition of the lithium-free transparent spinel 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%;

[0047] Wherein, the lithium-free transparent spinel glass-ceramics substantially does not contain Li2O, and in terms of mol%, the Li2O content is less than 0.01%.

[0048] Preferably, in the above preparation method, the heat treatment includes 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 0-72 hours, preferably 0-24 hours;

[0049] and / or, the crystallization temperature is 700 to 1000° C., preferably 700 to 800° C., preferably, the crystallization time is 0.1 to 72 h, preferably 0.1 to 24 h; and / or,

[0050] During heat treatment, the heating rate is controlled to be 5 to 15 K / min.

[0051] Preferably, in the above preparation method, the composition of the lithium-free transparent spinel glass-ceramics satisfies the following conditions, based on the content expressed as the molar percentage of each oxide in the lithium-free transparent spinel glass composition:

[0052] A=0.65×Al2O3+3.5×ZrO2-0.8×Na2O-2.5×B2O3, wherein A≤0.18, preferably the value of A is 0.05~0.15;

[0053] and / or, B = 3.8 × Na2O + B2O3 + 4.5 × MgO + 6.0 × ZnO - 0.4 × Al2O3 - SiO2, wherein B ≤ 0.80, preferably the value of B is 0.60 to 0.78;

[0054] and / or, X=2.1×(Al2O3-MgO-ZnO) / (SiO2+Al2O3-MgO-ZnO+Na2O+K2O+B2O3), wherein X=30.00-50.00%, preferably X=34.00-46.00%;

[0055] and / or, Y=(2.7×Na2O+1.8×(Al2O3-MgO-ZnO)) / (SiO2+Al2O3-MgO-ZnO+Na2O+K2O+B2O3), wherein Y=60.00-80.00%, preferably Y=60.00-75.00%;

[0056] And / or, in the lithium-free transparent spinel glass-ceramics, Al2O 3、 The molar percentages of the components of MgO and ZnO satisfy the following relationship: Al2O3-MgO-ZnO=8.00~15.00%.

[0057] Preferably, in the above preparation method, the lithium-free transparent spinel glass-ceramics substantially does not contain BaO, and the BaO content is less than 0.01% in mol%; and / or,

[0058] The lithium-free transparent spinel glass-ceramics does not contain TiO2 substantially, and in terms of mol%, the TiO2 content is less than 0.01%.

[0059] On the other hand, the present invention also provides a substrate glass for preparing the above-mentioned lithium-free transparent spinel glass-ceramics, wherein the substrate glass contains the following oxides in mol% proportions: 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 substrate glass basically does not contain Li2O, and the content of Li2O is less than 0.01% in mol%.

[0060] Preferably, the composition of the substrate glass satisfies the following conditions, based on the content expressed as a molar percentage of each oxide in the substrate glass composition:

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

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

[0063] and / or, X=2.1×(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×Na2O+1.8×(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, in the substrate glass, the molar percentages of the components Al2O3, MgO and ZnO satisfy the following relationship: Al2O3-MgO-ZnO=8.00-15.00%.

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

[0067] The substrate glass substantially does not contain TiO2, and in terms of mol%, TiO2 is less than 0.01%.

[0068] On the other hand, the present invention also provides a chemically strengthened glass, which comprises the above-mentioned lithium-free transparent spinel microcrystalline glass or the lithium-free transparent spinel microcrystalline glass prepared by the above-mentioned preparation method or the above-mentioned substrate glass obtained by chemical strengthening treatment.

[0069] On the other hand, the present invention also provides the use of the above-mentioned lithium-free transparent spinel glass-ceramics or the lithium-free transparent spinel glass-ceramics prepared by the above-mentioned preparation method or the above-mentioned substrate glass or the above-mentioned chemically strengthened glass in mobile phone displays, tablet computer displays, handheld game consoles, electronic terminals, portable digital devices, vehicle central control screens, electronic whiteboard glass, smart home touch screens, vehicle windshields, aircraft windshields or aircraft windshields.

[0070] Beneficial effects of the present invention:

[0071] 1. The lithium-free transparent spinel glass-ceramics provided by the present invention has good economic benefits. On the one hand, the glass-ceramics of the present invention 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 substrate glass corresponding to the optimized glass formula of the present invention has low melting difficulty and is not prone to melting defects. And when the heat treatment temperature does not exceed 800°C, a transparent glass-ceramics with a main crystal phase of zinc-magnesium spinel solid solution, excellent optical properties and high intrinsic strength can be obtained. The difficulty of mass production of transparent spinel glass-ceramics is greatly reduced, and the possibility of mass production is higher, which meets the development needs of the industry for energy conservation and carbon reduction.

[0072] 2. The lithium-free transparent spinel glass-ceramics provided by the present invention has high intrinsic strength, and can obtain strengthened glass-ceramics with excellent drop impact resistance by chemical strengthening, which can meet the use requirements of electronic equipment cover glass. The present invention adjusts the amount of each oxide in the formula and the amount relationship of each oxide, and utilizes the synergistic coordination of each oxide component with a specific content. While obtaining the required content target main crystal phase (Zn, Mg) Al2O4, the glass-ceramics has a specific network structure, and a large amount of main crystal phase (Zn, Mg) Al2O4 with high Young's modulus and shear modulus is evenly distributed in the specific glass network structure, which greatly improves the intrinsic strength of the glass-ceramics. On this basis, by chemically strengthening the glass-ceramics, it is possible to obtain strengthened glass-ceramics with excellent surface stress characteristics and excellent deep stress characteristics. By utilizing high intrinsic strength combined with excellent surface stress characteristics and deep stress characteristics, the strengthened glass-ceramics is endowed with excellent mechanical properties, so that the strengthened glass-ceramics has excellent drop impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 This is a diagram of the melting results of the substrate glass of Example 1;

[0074] Figure 2 This is a diagram showing the melting results of the substrate glass of Example 3;

[0075] Figure 3This is a diagram showing the melting results of the substrate glass of Example 4;

[0076] Figure 4 This is an appearance diagram of the lithium-free transparent spinel glass-ceramics of Example 4;

[0077] Figure 5 This is an appearance diagram of the lithium-free transparent spinel glass-ceramics of Example 5;

[0078] Figure 6 is a thermogravimetric analysis curve of the substrate glass of Example 1;

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

[0080] Figure 8 1 is the transmittance curve of the lithium-free transparent spinel glass-ceramics of Example 5 under different wavelength conditions;

[0081] Fig. 9 This is a diagram of the melting results of the substrate glass of Comparative Example 1;

[0082] Fig.10 This is a diagram showing the melting results of the substrate glass of Comparative Example 2;

[0083] Fig.11 This is a diagram of the melting results of the substrate glass of Comparative Example 3;

[0084] Fig.12 This is a diagram of the melting results of the substrate glass of Comparative Example 6;

[0085] Fig.13 This is the appearance of the microcrystalline glass of comparative example 19. DETAILED DESCRIPTION

[0086] After repeated experiments and studies, the inventors have obtained the lithium-free transparent spinel glass-ceramics of the present invention that takes into account melting effect, stress effect, optical effect and mechanical properties by regulating the content and content ratio of the specific components constituting the glass-ceramics to a specific ratio.

[0087] In the present invention, unless otherwise specified in specific circumstances, the numerical ranges listed herein include upper and lower limits, and "above" and "below" include the endpoint values, as well as all integers and fractions within the range, and are not limited to the specific values ​​listed when the range is defined. "And / or" referred to herein 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 to describe constituent components of a composition, batch, melt or article refers to constituent components that have not been actively added or dosed into the composition, batch, melt or article but may be present in small amounts of less than about 0.01% (on an oxide mole basis) as a contaminant and / or due to the inherent degree of uncertainty attributable to any measurement or analytical technique.

[0089] In the present invention, glass-ceramics, also known as glass ceramics, are a type of solid composite material that is prepared by targeted controlled heat treatment of substrate glass and contains both glass phase and crystal phase (microcrystalline phase, crystal phase, crystalline phase). It should be understood that both crystal phase and crystal grain refer to crystals precipitated from glass-ceramics, but are described in different ways. The crystal phase is the microscopic structure of the crystal, which is determined by the conformation and arrangement of the polymer chains in the crystal.

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

[0091] In the present invention, chemically strengthened glass refers to a solid composite material obtained by chemically strengthening substrate glass or glass-ceramics. Glass-ceramics are strengthened by chemically strengthening to obtain strengthened glass-ceramics.

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

[0093] In the present invention, nucleation treatment refers to growing small crystal nuclei from nucleating substances in the glass through heat treatment; crystallization treatment refers to growing certain crystals based on the crystal nuclei through heat treatment.

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

[0095] In the present invention, the crystallization temperature refers to the temperature at which the target crystal growth rate can be controlled.

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

[0097] Transmittance refers to the ratio of the radiation energy projected and transmitted through the object to the total radiation energy projected on the object during the process of the incident light flux leaving from the illuminated surface or the incident surface of the medium to the other side. It should be understood that when a certain wavelength is irradiated on the glass surface, 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 invention, the transmittance result of the microcrystalline glass at a wavelength of 550nm refers to the average transmittance of multiple glass samples of the same batch measured at a wavelength of 550nm, and at least 5 samples of each batch of microcrystalline glass are taken for testing. In the present invention, a Konica Minolta spectrophotometer CM-3600A is used to test the transmittance of each glass sample at a wavelength of 550nm.

[0099] In the present invention, fogging refers to a semi-transparent state due to larger crystals or phase separation in the microcrystalline glass / glass ceramics, which is a state between transparency and devitrification.

[0100] In the present invention, devitrification means that due to the large crystals or phase separation in the microcrystalline glass / glass ceramic, the transparent property of the glass is completely lost, and any image on the back cannot be seen through the glass.

[0101] In the present invention, surface CS refers to surface compressive stress or surface compression stress. After the microcrystalline glass / glass ceramics are chemically strengthened, the alkali metal ions with a smaller radius on the surface are replaced by alkali metal ions with a larger radius. Due to the crowding effect of the alkali metal ions with a larger radius, compressive stress is generated on the glass surface, which is called surface compressive stress.

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

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

[0104] In the present invention, 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 a position close to the surface where the compressive stress is zero.

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

[0106] In the present invention, CT_LD refers to tensile stress linear density, which is the ratio of the absolute value of the sum of tensile stresses of strengthened microcrystalline glass measured by SLP-2000 stress meter to the glass thickness. Microcrystalline glass is placed in a salt bath for ion exchange to form a compressive stress layer (i.e., a strengthening layer). During the ion exchange process, a tensile stress layer is formed inside the glass. The tensile stress layer has an upper boundary that is spaced a certain distance from the upper surface of the strengthened microcrystalline glass and a lower boundary that is spaced a certain distance from the lower surface of the strengthened glass. A curve drawn with the tensile stress magnitude at a certain point on a line segment in the tensile stress layer that is perpendicular to the upper boundary and the lower boundary and whose upper and lower endpoints fall on the upper boundary and the lower boundary respectively as the Y axis and the distance from the corresponding point to the upper boundary as the X axis is recorded as a tensile stress curve, and the ratio of the definite integral of the tensile stress curve to the thickness of the strengthened microcrystalline glass is recorded as a tensile stress linear density.

[0107] In the present invention, SOC refers to the photoelastic coefficient. Photoelasticity mainly refers to the phenomenon of birefringence caused by anisotropy of transparent materials after being subjected to force. The value of the residual stress (MPa) inside the material can be obtained by measuring the photoelastic coefficient and birefringence.

[0108] In the present invention, the surface K2O concentration is equal to the K2O mass / total oxide mass, wherein the total oxide mass includes oxides such as SiO2, Al2O3, P2O5, ZrO2, Na2O, K2O, etc. that can be accurately tested by XRF, and does not include the content of oxides such as Li2O and B2O3 that cannot be accurately tested by XRF. The XRF test uses a non-standard test, and the concentration of elements or their oxides with atomic numbers 6 and below in the glass is not tested. That is, when calculating the K2O concentration obtained by the XRF test in the present invention, the total oxide mass does not include the mass of elements or their oxides with atomic numbers 6 and below in the glass.

[0109] In the present invention, Vickers hardness refers to a standard for expressing the hardness of a material proposed by Robert L. Smith and George E. Sandl and in Vickers Ltd in 1921.

[0110] In the present invention, fracture toughness refers to the impedance value displayed by the material when there is a crack or a crack-like defect in the sample or component and the material no longer breaks rapidly with the increase of load, that is, when the so-called unstable fracture occurs.

[0111] In a first aspect, in a specific embodiment of the present invention, the lithium-free transparent spinel glass-ceramics is prepared by heat treatment of a substrate glass. The present invention provides a lithium-free transparent spinel glass-ceramics, wherein the lithium-free transparent spinel glass-ceramics contains spinel crystals, and the spinel crystals are the main crystalline phase of the lithium-free transparent spinel glass-ceramics;

[0112] The composition of the lithium-free transparent spinel glass-ceramics contains the following proportions of oxides, calculated 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 lithium-free transparent spinel glass-ceramics basically does not contain Li2O, and, calculated in mol%, Li2O is less than 0.01%.

[0113] Next, the range of each component (ingredient) of the lithium-free transparent spinel glass-ceramics of the present invention is explained.

[0114] The inventors have found that in the formula system of the present invention, the appropriate increase in the content of Na2O helps the chemical strengthening of microcrystalline glass to obtain higher stress characteristics, including high surface stress characteristics and high deep stress characteristics, and can also reduce the melting temperature and the temperature of crystal precipitation. If the content of Na2O is too low, it is not only not conducive to strengthening microcrystalline glass to obtain high stress characteristics, but also leads to an increase in the heat treatment temperature, increasing the difficulty of mass production of microcrystalline glass, and during the heat treatment process, it is also easy to cause direct phase separation or precipitation of impurities that affect the optical properties of microcrystalline glass, resulting in translucent or even opaque microcrystalline glass. The excessive addition of Na2O will affect the network structure of the glass due to the provision of a large amount of free oxygen, and it is also easy to cause the ceramicization of the substrate glass during the annealing process or the precipitation of impurities that affect the optical properties of microcrystalline glass during the heat treatment of the substrate glass to reduce the transmittance of the obtained microcrystalline glass. Therefore, in the present invention, the content of Na2O is 7.20-14.00%, preferably 7.20-13.00%, and more preferably 7.20-12.00%.

[0115] In some embodiments, the lithium-free transparent spinel glass-ceramics may contain 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% Na2O. In some embodiments, the lithium-free transparent spinel glass-ceramics may contain 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% Na2O in molar percentage, or Na2O in a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

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

[0117] In some embodiments, the lithium-free transparent spinel glass-ceramics may include 38.00% to 48.00%, 38.50% to 48.00%, 39.00% to 48.00%, 40.00% to 48.00%, 42.00% to 48.00%, 44.00% to 48.00%, 38.00% to 46.00%, 38.00% to 44.00%,

[0118] 38.00% to 42.00% or 38.00% to 40.00% SiO2. In some embodiments, the lithium-free transparent spinel glass-ceramics may contain SiO2 with a molar percentage of 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%, or SiO2 within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the glass with the desired properties of the present invention can be obtained.

[0119] The inventors have found that in the formula system of the present invention, the appropriate addition of Al2O3 can not only promote the precipitation of the main crystal phase spinel, inhibit the precipitation of other impurities such as quartz SS that affect the optical properties of the microcrystalline glass of the present system, but also increase the ion exchange rate during the strengthening process and promote the ion exchange. However, too much Al2O3 will cause the melting difficulty of the substrate glass to increase sharply, and at the same time accelerate the crystallization rate of the substrate glass, so that the substrate glass is prone to crystallization and devitrification during the normal cooling process during preparation. Therefore, in the present invention, the Al2O3 content is 25.50-30.00% in mol%, preferably 25.50-28.00%.

[0120] In some embodiments, the lithium-free transparent spinel glass-ceramics may contain Al2O3 in a molar percentage of 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%. In some embodiments, the lithium-free transparent spinel glass-ceramics may contain Al2O3 in a molar percentage of 25.50%, 26.00%, 26.50%, 27.00%, 27.50%, 28.00%, 28.50%, 29.00%, 29.50% or 30.00%, or Al2O3 in a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

[0121] The inventors have found that in the formula system of the present invention, MgO and ZnO, as the main components of spinel, can promote the precipitation of spinel when added in appropriate amounts, and can also reduce the difficulty of melting the substrate glass to a certain extent. However, the addition of excessive MgO and ZnO often causes the spinel grains to grow very easily, and it is difficult to obtain microcrystalline glass with high transparency. That is, the content relationship of MgO and ZnO largely determines whether the microcrystalline glass sample can be transparent and whether the optical properties are excellent. Therefore, in the present invention, in terms of mol%, the MgO content is 5.00% to 8.00%, preferably 5.00 to 7.00%, and more preferably 5.00 to 6.50%; the ZnO content is 8.00% to 14.00%, preferably 8.00 to 12.00%, and more preferably 8.00 to 10.50%.

[0122] In some embodiments, the above-mentioned lithium-free transparent spinel glass-ceramics may contain MgO with 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 above-mentioned lithium-free transparent spinel glass-ceramics may contain MgO with a molar percentage of 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50 or 8.00%, or MgO within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

[0123] In some embodiments, the lithium-free transparent spinel glass-ceramics may contain 8.50% to 14.00%, 9.00% to 14.00%, 9.50% to 14.00%, 10.00 to 14.00%, 10.50 to 14.00%, 11.00 to 14.00%, 11.50 to 14.00%, 12.00 to 14.00%, 8.00 to 13.50, 8.00 to 13.00, 8.00 to 12.50, 8.00 to 12.00, 8.00 to 11.50, 8.00 to 11.00, 8.00 to 10.50 or 8.00 to 10.00% ZnO. In some embodiments, the lithium-free transparent spinel glass-ceramics may contain 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% ZnO in molar percentage, or ZnO in a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

[0124] The inventors have found that in the formula system of the present invention, ZrO2 acts as an effective nucleating agent. When the substrate glass is heat-treated to prepare microcrystalline glass, ZrO2 is first precipitated from the glass in the form of crystals, and the ZrO2 crystals become crystal nuclei for the subsequent growth of the main crystal spinel. Within a certain glass composition range, the content of ZrO2 will affect the formation of the substrate glass, the crystal shape, crystal type and crystal size of the microcrystalline glass after the substrate glass is heat-treated. Therefore, in the present invention, the ZrO2 content is 3.00-5.00%, preferably 3.00-4.00%, in terms of mol%.

[0125] In some embodiments, the above-mentioned lithium-free transparent spinel glass-ceramics may contain ZrO2 with 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 above-mentioned lithium-free transparent spinel glass-ceramics may contain ZrO2 with a molar percentage of 3.00%, 3.50%, 4.00%, 4.50% or 5.00%, or ZrO2 within a numerical range consisting of any two of the above-mentioned specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above-mentioned ranges can be combined with any other ranges, as long as the glass with the desired properties of the present invention can be obtained.

[0126] The inventors have found that in the formula system of the present invention, an appropriate amount of B2O3 can not only greatly reduce the difficulty of melting the substrate glass, but also help promote the precipitation of the main crystal phase spinel. When the amount of B2O3 added is too low, it is easy to cause melting defects during the preparation of the substrate glass. However, the addition of excessive B2O3 can easily lead to opacity in the glass when the substrate glass is heat-treated to prepare microcrystalline glass. At the same time, it may cause the precipitation of other impurity crystal phases, seriously affecting the transparency of the microcrystalline glass. Therefore, in the present invention, the content of B2O3 is 3.00-8.00% in mol%, preferably 3.00-7.00%, and more preferably 3.00-6.50%.

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

[0128] In order to ensure the melting effect and optical properties of the glass, in the present invention, Na2O+B2O3 is 10.20-20.00%, preferably 10.20-18.00%. The coordination of Na2O+B2O3 and the overall composition can solve the melting problem while enabling the base glass to obtain better optical properties. At the same time, the increase of Na2O and B2O3 can synergistically solve the melting problem caused by the increase of Al2O3 content.

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

[0130] The inventors have found that in the formula system of the present invention, the addition of TiO2 as a nucleating agent will cause the substrate glass to have an undesirable color. In order to obtain the desired transparent colorless microcrystalline glass, the present invention preferably does not contain TiO2, and the TiO2 content is less than 0.01% in mol%.

[0131] The inventors have found that in the formulation system of the present invention, K2O is an optional component that helps to improve the low temperature melting property and formability of the glass. + Radius larger than Na + , adding K2O in proper amount can reduce the tendency of glass to crystallize and increase the transparency and gloss of glass. However, if K2O is contained in excessive amount, it is not only easy to reduce the chemical stability and hardness of glass, but also easy to make the crystallization ability of glass stronger, glass is easy to lose transparency, and crystallized glass is easy to break. Therefore, in the present invention, the content of K2O is 0 to 2.00% in mol%.

[0132] The inventors have found that in the formula system of the present invention, Y2O3 is an optional component that improves the hardness and chemical stability of glass ceramics and inhibits the crystallization of glass forming. An appropriate amount of Y2O3 can improve the density of the glass phase, thereby improving the overall strength of the microcrystalline glass. At the same time, it can form a eutectic with ZrO2, reducing the unevenness caused by ZrO2 precipitation when melting in the furnace. However, when the Y2O3 content is too high, it will affect the precipitation of spinel crystals and reduce the chemical strengthening properties of glass and glass ceramics. Therefore, in the present invention, the Y2O3 content ranges from 0 to 1.00% in terms of mol%.

[0133] In some preferred embodiments of the present invention, the composition of the lithium-free transparent spinel glass-ceramics of the present invention satisfies the following requirements, based on the content of each oxide in the lithium-free transparent spinel glass composition expressed in mole percentage:

[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 to 0.15.

[0135] (1)A=0.65×A l2O3+3.5×ZrO2-0.8×Na2O-2.5×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 the preferred value of B is 0.60 to 0.78.

[0138] (2)B=3.8×Na2O+B2O3+4.5×MgO+6.0×ZnO-0.4×A l2O3-SiO2.

[0139] The inventors have discovered through experimental studies that the A value calculated based on the above formula is closely related to the melting effect of the substrate glass used to prepare the lithium-free transparent spinel glass-ceramics. By controlling the A value within an appropriate range through the specific proportional relationship of the above-mentioned oxide components, it can be ensured that a transparent substrate glass that meets the requirements is obtained, and that the oxide components in the substrate glass are completely melted without any unmelted components.

[0140] The inventors have also discovered through experiments that the B value calculated based on the above formula is also closely related to the melting effect of the substrate glass used to prepare the lithium-free transparent spinel glass-ceramics. By controlling the B value within an appropriate range through the specific proportional relationship of the above-mentioned oxide components, it can be ensured that the substrate glass will not be ceramicized during the preparation process, especially during the annealing process, thereby ensuring that a transparent substrate glass that meets the requirements is obtained.

[0141] In some embodiments, the A value may 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 above-mentioned lithium-free transparent spinel glass-ceramics may 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 consisting of any two of the above-mentioned specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above-mentioned ranges can be combined with any other ranges, as long as the glass with the desired performance of the present invention can be obtained.

[0142] In some embodiments, the B value may 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 glass-ceramics may 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 consisting of any two of the above specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges may be combined with any other ranges, as long as the glass with the desired properties of the present invention can be obtained.

[0143] In some preferred embodiments of the present invention, in the above-mentioned lithium-free transparent spinel glass-ceramics, the molar percentages of the components Al2O3, MgO, and ZnO satisfy the following relationship: the molar percentage of Al2O3 minus the molar percentage of MgO and the molar percentage of ZnO is 8.00 to 15.00%, that is, the value of Al2O3-MgO-ZnO is 8.00 to 15.00%. Al2O3, MgO and ZnO are all main components of the main crystal phase spinel crystal of the present invention. By adjusting the content relationship of Al2O3, MgO and ZnO, the present invention can, on the one hand, ensure the acquisition of microcrystalline glass with high crystal content / crystallinity, which is beneficial to improving the intrinsic strength of the microcrystalline glass. On the other hand, by leaving an appropriate amount of Al2O3 in the residual glass phase to form an [AlO4] tetrahedron structure, it is also more conducive to achieving chemical strengthening of the microcrystalline glass and helping the microcrystalline glass to obtain high stress characteristics after strengthening. Because the volume of the [AlO4] tetrahedron is larger than that of [SiO4], the presence of an appropriate amount of [AlO4] is more conducive to broadening 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 lithium-free transparent spinel glass-ceramics may contain Al2O3-MgO-ZnO in 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 in a value of Al2O3-MgO-ZnO in a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

[0145] In another preferred embodiment of the present invention, the composition of the lithium-free transparent spinel glass-ceramics of the present invention satisfies the following conditions, based on the content of each oxide in the lithium-free transparent spinel glass composition expressed in mole percentage:

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

[0147] (3)X=2.1×(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 to 80.00%, preferably 60.00 to 75.00%.

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

[0151] +K2O+B2O3).

[0152] The inventors have found through experimental research that the X value 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. By controlling the X value within an appropriate range through the specific proportional relationship of the above-mentioned oxide components, it can be ensured that the glass-ceramics of the present invention obtains excellent deep stress characteristics after chemical strengthening, such as high CS_50, DOL_O, |CT_AV|, |CT_CV|, and CT_LD values.

[0153] The inventors also discovered through experimental studies that the Y value 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. By controlling the Y value within an appropriate range through the specific proportional relationship of the above-mentioned oxide components, it can be ensured that the glass-ceramics of the present invention obtains excellent surface stress characteristics after chemical strengthening, such as a high surface K2O concentration and a high surface CS value.

[0154] In some embodiments, the value of 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 may 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 an X value within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

[0155] In some embodiments, the Y value 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 may 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 Y value within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

[0156] In some preferred embodiments of the present invention, the spinel crystal of the present invention is a zinc-magnesium spinel solid solution (Zn, Mg)Al2O4, that is, the main crystalline phase of the lithium-free transparent spinel glass-ceramics of the present invention is (Zn, Mg)Al2O4; and / or, the lithium-free transparent spinel glass-ceramics of the present invention also includes a secondary crystalline phase of tetragonal zirconium oxide. (Zn, Mg)Al2O4 has a high Young's modulus and shear modulus, which is conducive to improving the intrinsic strength of the glass-ceramics and glass-ceramics products of the present invention, such as making the glass-ceramics and glass-ceramics products have high hardness, strength, fracture toughness, etc.

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

[0158] In some embodiments, the crystallinity of the lithium-free transparent spinel glass-ceramics of the present invention may be 22.00-50.00wt%, 24.00-50.00wt%, 26.00-50.00wt%, 28.00-50.00wt%, 30.00-50.00wt%, 32.00-50.00wt%, 34.00-50.00wt%, 36.00-50.00wt%, 38.00-50.00wt%, 40.00-50.00wt%, 42.00-50.00wt%, 44.00-50.00wt%. %, 46.00~50.00wt%, 20.00~48.00wt%, 20.00~46.00wt%, 20.00~44.00wt%, 20.00~42.00wt%, 20.00~40.00wt%, 20.00~38.00wt%, 20.00~36.00wt%, 20.00~34.00wt%, 20.00~32.00wt%, 20.00~30.00wt%, 20.00~28.00wt%, 20.00~26.00wt% or 20.00~24.00wt%. In some embodiments, the above-mentioned lithium-free transparent spinel glass-ceramics (also chemically strengthened glass-ceramics) may include a crystallinity value of 20.00wt%, 22.00wt%, 24.00wt%, 26.00wt%, 28.00wt%, 30.00wt%, 32.00wt%, 34.00wt%, 35.00wt%, 36.00wt%, 38.00wt%, 40.00wt%, 42.00%, 44.00wt%, 45.00wt%, 46.00wt%, 48.00wt% or 50.00wt%, or a crystallinity value within a numerical range consisting of any two of the above-mentioned specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

[0159] In some preferred embodiments of the present invention, the average grain size of the lithium-free transparent spinel glass-ceramics of the present invention is ≤15.0 nm, preferably 1.0 to 15.0 nm, more preferably 1.0 to 10.0 nm, and more preferably 4.5 to 8.0 nm. Appropriate grain size is conducive to achieving excellent optical effects of the glass-ceramics.

[0160] In some embodiments, the average grain size of the lithium-free transparent spinel glass-ceramics of the present invention may be 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 above-mentioned lithium-free transparent spinel glass-ceramics may include 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 numerical range consisting of any two of the above-mentioned specific numerical values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges may be combined with any other ranges, as long as the glass with the desired properties of the present invention can be obtained.

[0161] In another preferred embodiment of the present invention, the lithium-free transparent spinel glass-ceramic of the present invention exhibits high transparency in the visible light range (i.e., the lithium-free transparent spinel glass-ceramic is transparent). The lithium-free transparent spinel glass-ceramic of the present invention exhibits high transmittance in the visible light range. For example, the lithium-free transparent spinel glass-ceramic, at a thickness of 0.7 mm, for light of a wavelength of 550 nm, has a transmittance greater than or equal to 85%, and preferably a transmittance greater than or equal to 89%.

[0162] In some embodiments, at a thickness of 0.7 mm, for light of 550 nm wavelength, the transmittance of the lithium-free transparent spinel glass-ceramics of the present invention can be 89.0%, 89.5%, 90.0%, 90.5% or 91.0%, or a transmittance within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the glass with the desired performance of the present invention can be obtained.

[0163] In some preferred embodiments of the present invention, the Young's modulus of the lithium-free transparent spinel glass-ceramics of the present invention is ≥100 GPa, preferably ≥110 GPa, and more preferably 114 GPa≤Young's modulus≤140 GPa.

[0164] In some embodiments, the Young's modulus of the lithium-free transparent spinel glass-ceramics of the present invention can be 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 Young's modulus of the lithium-free transparent spinel glass-ceramics may be 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 value within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired performance of the present invention can be obtained.

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

[0166] In some embodiments, at a thickness of 0.7 mm, the optical b-value of the lithium-free transparent spinel glass-ceramics of the present invention can be 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. In some embodiments, the optical b value of the lithium-free transparent spinel glass-ceramics may be 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 numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired performance of the present invention can be obtained.

[0167] In a second aspect, the lithium-free transparent spinel glass-ceramics of the present invention can be produced and manufactured by the following method: heat-treating a substrate glass to form the above-mentioned lithium-free transparent spinel glass-ceramics; the lithium-free transparent spinel glass-ceramics contain spinel crystals, and the spinel crystals are the main crystalline phase of the lithium-free transparent spinel glass-ceramics; the composition of the lithium-free transparent spinel glass-ceramics contains the following proportions of 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%; wherein, the lithium-free transparent spinel glass-ceramics basically does not contain Li2O, and in mol%, Li2O is less than 0.01%.

[0168] Exemplarily, the method for preparing the lithium-free transparent spinel glass-ceramics in the present invention may include the following steps:

[0169] (1) preparing a substrate glass: the substrate glass contains the following oxides in mol% ratio: 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 substrate glass substantially does not contain Li2O, and Li2O in mol% ratio is less than 0.01%;

[0170] (2) Preparation of lithium-free transparent spinel glass-ceramics: The substrate glass obtained in step (1) is heat-treated to obtain lithium-free transparent spinel glass-ceramics.

[0171] It should be understood that the composition of the substrate glass is the same as the composition of the lithium-free transparent spinel micro-ceramic glass of the present invention, measured in mol% of oxides.

[0172] The heat treatment in step (2) may include a nucleation treatment and / or a crystallization treatment, that is, when the substrate glass is heat treated, a one-step heat treatment may be performed or a two-step or multi-step heat treatment may be performed. If a one-step heat treatment is performed, it means that the nucleation treatment is not performed separately, and the nucleation and target crystal growth are directly performed in a one-step heating process, which can be understood as a direct crystallization treatment. If a two-step heat treatment is performed, it means that a two-step heating process is performed, first a nucleation treatment, i.e., a nucleation treatment, is performed, and then a target crystal growth treatment, i.e., a crystallization treatment, is performed.

[0173] It should be understood that in the present invention, the nucleation treatment is to increase the temperature to a prescribed nucleation treatment temperature (also called nucleation temperature), and after reaching the nucleation treatment temperature, maintain the temperature for a certain time (i.e., nucleation treatment time, also called nucleation time). The crystallization treatment is to increase the temperature to a prescribed crystallization treatment temperature (also called crystallization temperature), and after reaching the crystallization treatment temperature, maintain the temperature for a certain time (i.e., crystallization treatment time, also called crystallization time).

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

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

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

[0177] In some preferred embodiments of the present invention, the lithium-free transparent spinel glass-ceramics is prepared by a two-step temperature-increasing heat treatment method, that is, the substrate glass is sequentially subjected to a nucleation treatment and a crystallization treatment method to prepare the glass-ceramics. In some embodiments, when the temperature of the nucleation treatment is 600-750°C, the nucleation treatment time is preferably 60-360 minutes, and the nucleation time is more preferably 100-300 minutes; and / or, when the temperature of the crystallization treatment is 700-800°C, the crystallization treatment time is preferably 60-360 minutes, and the crystallization time is more preferably 100-300 minutes.

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

[0179] In some preferred embodiments of the present invention, the composition of the substrate glass of the present invention satisfies the following conditions, based on the content expressed as a molar percentage of each oxide in the substrate glass composition:

[0180] A=0.65×Al2O3+3.5×ZrO2-0.8×Na2O-2.5×B2O3, wherein A≤0.18, and the preferred value of A is 0.05~0.15;

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

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

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

[0184] And / or, in the chemically strengthened glass-ceramics, Al2O 3、 The molar percentages of the components of MgO and ZnO satisfy the following relationship: Al2O3-MgO-ZnO=8.00~15.00%.

[0185] In some preferred embodiments of the present invention, the substrate glass of the present invention substantially does not contain BaO, and the BaO content is less than 0.01% on a mol% basis; and / or, the substrate glass substantially does not contain TiO2, and the TiO2 content is less than 0.01% on a mol% basis.

[0186] In the present invention, the lithium-free transparent spinel glass-ceramics obtained in the above step (2) can be cold-processed as needed. The cold-processing treatment is to process the glass-ceramics into glass-ceramics samples. For example, the glass-ceramics can be processed into polished sheets of required sizes by one or more methods of slicing, grinding, and polishing, such as polished sheets with a length, width, and thickness of 50 mm×50 mm×0.7 mm.

[0187] In the present invention, those skilled in the art can select the thickness of the lithium-free transparent spinel glass-ceramics according to needs. Exemplarily, the thickness of the lithium-free transparent spinel glass-ceramics is 0.2-5.0 mm.

[0188] In the present invention, the molding method of the substrate glass includes but is not limited to float, overflow, rolling or casting process. Exemplarily, the components are mixed evenly according to the formula, and after melting and molding, they are cooled and annealed to obtain the substrate glass. Preferably, the mixed raw materials are placed in an electric furnace or a gas furnace, and melted at a melting temperature of 1250°C to 1650°C, more preferably at a melting temperature of 1480°C to 1650°C, and the melting time is 5 to 24 hours; after the melting treatment is completed, the glass liquid is cast into a mold for molding, and after cooling to 850°C to 1000°C, it is preferably placed in an annealing furnace for annealing, and the annealing temperature is 500°C to 650°C, and the annealing is kept warm for 12 to 48 hours.

[0189] In the present invention, when preparing the substrate glass, a clarifier may be added to the raw materials for preparing the substrate glass, and the clarifier 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. Based on the total mass of the raw materials of the substrate glass, the amount of the clarifier added is 0.01wt% to 2.00wt%, preferably 0.01wt% to 1.50wt%.

[0190] In a third aspect, the present invention further provides a chemically strengthened glass, the chemically strengthened glass comprising the above-mentioned lithium-free transparent spinel glass-ceramics or the lithium-free transparent spinel glass-ceramics prepared by the above-mentioned method or the above-mentioned substrate glass after chemical strengthening treatment. The above-mentioned lithium-free transparent spinel glass-ceramics is subjected to chemical strengthening treatment to obtain strengthened glass-ceramics, and the strengthened glass-ceramics comprises a compressive stress layer and a tensile stress layer.

[0191] In some embodiments, the lithium-free transparent spinel glass-ceramics can be processed into sheets, and / or shaped (such as punching, hot bending, etc.), polished and / or swept after shaping, and then chemically strengthened through a chemical strengthening process.

[0192] The chemical strengthening treatment described in the present invention is an ion exchange method. During the ion exchange process, the smaller alkali metal ions in the lithium-free transparent spinel glass-ceramics are replaced or "exchanged" by larger alkali metal ions with the same valence state close to the glass-ceramics, and the larger ions replace the smaller ions, thereby constructing 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. The ion exchange is carried out by immersing the glass-ceramics or substrate glass in a salt bath of at least one molten salt containing larger alkali metal ions, so that the larger alkali metal ions in the salt bath replace the smaller alkali metal ions in the glass-ceramics or substrate glass. Alternatively, other monovalent metal ions such as Ag + , Tl+ , Cu + etc. can also be used to exchange monovalent ions. The ion exchange process may include, but is not limited to, immersing it in a single salt bath, or immersing it in multiple salt baths of the same or different compositions, with washing and / or annealing steps between immersions.

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

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

[0195] In the present invention, through a chemical strengthening treatment step, K ions in the salt bath replace part of the Na ions in the microcrystalline glass or the substrate glass, thereby forming a compressive stress layer on the glass surface to obtain a strengthened microcrystalline glass, so that the microcrystalline glass or the substrate glass achieves a specific stress distribution structure, giving the microcrystalline glass or the substrate glass specific and excellent surface stress characteristics and deep stress characteristics, thereby giving it high mechanical properties.

[0196] In some embodiments, before the chemical strengthening treatment, the glass-ceramics or the substrate glass may be preheated at 300 to 400° C. as required, and the preheating time is preferably 10 to 30 minutes.

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

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

[0199] In some preferred embodiments of the present invention, the strengthened glass-ceramics comprises a compressive stress layer and a tensile stress layer, the main crystalline phase of the strengthened glass-ceramics is (Zn, Mg)Al2O4, and the secondary crystalline phase comprises tetragonal zirconia; the composition of the strengthened glass-ceramics does not substantially contain Li2O, and in terms of mol%, Li2O is less than 0.01%.

[0200] It should be understood that after the chemical strengthening ion exchange process, the composition of the surface of the glass-ceramic or substrate glass may be different from the composition of the newly formed glass-ceramic or substrate glass (i.e., the glass-ceramic or substrate glass that has not undergone ion exchange). That is, the composition of the compressive stress layer formed by ion exchange on the surface of the strengthened glass-ceramic may be different from the composition of the chemically strengthened glass-ceramic (i.e., lithium-free transparent spinel glass-ceramic). This is because during ion exchange, one type of alkali metal ion (e.g., Li + Or Na + ) are replaced by larger alkali metal ions (e.g., Na + or K + ) is replaced by, such as Na in glass + K in strengthening salt bath + Exchange, K + Replaced by, and / or, Li in glass + and Na in the strengthening salt bath + Exchange, by Na + However, in the embodiment, the composition of the glass-ceramic or substrate glass at the center of the depth of the glass product or near the center of the depth will still have the composition of the newly formed glass-ceramic or substrate glass. That is, in the present invention, the composition of the tensile stress layer of the strengthened glass-ceramic will still have the composition of the above-mentioned lithium-free transparent spinel glass-ceramic (that is, the chemically strengthened glass-ceramic in the present invention).

[0201] In the present invention, since the exchange of alkali metal ions occurs during the chemical strengthening process, the main crystalline phase of the chemically strengthened glass-ceramics of the present invention, i.e., the lithium-free transparent spinel glass-ceramics, is (Zn, Mg)Al2O4, and the secondary crystalline phase includes tetragonal ZrO2, neither of which participates in the ion exchange. Therefore, the main crystalline phase of the strengthened glass-ceramics obtained after chemical strengthening is still (Zn, Mg)Al2O4, and the secondary crystalline phase includes tetragonal ZrO2.

[0202] The present invention has conducted an in-depth study on the intrinsic strength of glass-ceramics and the stress characteristics that can be obtained by strengthening the glass-ceramics after strengthening. By strengthening a specific system of glass-ceramics with high intrinsic strength to meet specific stress characteristics, a strengthened glass-ceramics with excellent mechanical properties, such as excellent drop impact resistance, is finally obtained. In the present invention, the excellent surface stress characteristics and deep stress characteristics are given to the strengthened glass-ceramics through the chemical strengthening process, combined with the high intrinsic strength that the glass-ceramics originally possesses, and ultimately the mechanical properties of the strengthened glass-ceramics are greatly improved, so that the strengthened glass-ceramics can achieve a drop impact resistance effect that is far superior to the existing spinel glass-ceramics.

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

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

[0205] In some preferred embodiments of the present invention, the strengthened glass-ceramics satisfies: |CT_CV|≥80MPa, preferably 300MPa≥|CT_CV|≥80MPa. In some embodiments, |CT_CV| may 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, the |CT_CV| of the strengthened glass-ceramics may be 80 MPa, 100 MPa, 120 MPa, 140 MPa, 160 MPa, 180 MPa, 200 MPa, 220 MPa, 240 MPa, 260 MPa, 280 MPa or 300 MPa, or a |CT_CV| within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges may be combined with any other ranges, as long as the glass having the desired properties of the present invention can be obtained.

[0206] In some preferred embodiments of the present invention, the strengthened glass-ceramics satisfies: |CT_AV|≥70MPa, preferably 200MPa≥|CT_AV|≥70MPa. In some embodiments, |CT_AV| may 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 strengthened glass-ceramics may be 70MPa, 90MPa, 110MPa, 120MPa, 140MPa, 160MPa, 180MPa or 200MPa, or a |CT_AV| in a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges may be combined with any other ranges, as long as the glass with the desired properties of the present invention can be obtained.

[0207] In some preferred embodiments of the present invention, the strengthened glass-ceramics satisfies: CS_50≥100MPa, preferably 500MPa≥CS_50≥140MPa. In some embodiments, CS_50 may 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, the CS_50 of the strengthened glass-ceramics may be 100 MPa, 140 MPa, 160 MPa, 180 MPa, 200 MPa, 220 MPa, 240 MPa, 260 MPa, 280 MPa, 300 MPa, 320 MPa, 340 MPa, 360 MPa, 380 MPa, 400 MPa, 420 MPa, 440 MPa, 460 MPa, 480 MPa or 500 MPa, or a CS_50 within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges may be combined with any other ranges, as long as the glass having the desired performance of the present invention can be obtained.

[0208] In some preferred embodiments of the present invention, the strengthened glass-ceramics satisfies: CT_LD is 40000MPa / mm-85000MPa / mm, preferably 45000MPa / mm-85000MPa / mm, and 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] In some embodiments, the tensile stress line density CT_LD of the strengthened glass-ceramics may be 40000MPa / mm, 45000MPa / mm, 50000MPa / mm, 55000MPa / mm, 60000MPa / mm, 65000MPa / mm,

[0211] 70000MPa / mm, 75000MPa / mm, 80000MPa / mm or 85000MPa / mm, or a tensile stress linear density CT_LD within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

[0212] In some preferred embodiments of the present invention, the surface K2O concentration of the strengthened glass-ceramics is ≥9.00wt%, preferably 9.00-16.00wt%. In some embodiments, the surface K2O concentration of the strengthened glass-ceramics may be 9.00-15.00wt%, 9.00-14.00wt%, 9.00-13.00wt%, 9.00-12.00wt%, 9.00-11.00wt%, 10.00-16.00wt%, 11.00-16.00wt%, 12.00-16.00wt%, 13.00-16.00wt% or 14.00-16.00wt%. In some embodiments, the surface K2O concentration of the strengthened glass-ceramics may be 9.00wt%, 10.00wt%, 11.00wt%, 12.00wt%, 13.00wt%, 14.00wt%, 15.00wt% or 16.00wt%, or a surface K2O concentration within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges may be combined with any other ranges, as long as the glass having the desired properties of the present invention can be obtained.

[0213] It should be understood that the strengthened glass-ceramics of the present invention are obtained by chemically strengthening the above-mentioned lithium-free transparent spinel glass-ceramics provided by the present invention. In the lithium-free transparent spinel glass-ceramics of the present invention, the main crystalline phase is (Zn, Mg)Al2O4, and the secondary crystalline phase includes tetragonal ZrO2. The crystalline phase does not contain alkali metals and does not participate in ion exchange, so the crystalline phase composition does not change basically before and after strengthening.

[0214] In some preferred embodiments of the present invention, the crystallinity of the strengthened 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%.

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

[0216] It should be understood that in the present invention, after the chemical strengthening treatment, the crystal phase composition in the microcrystalline glass is basically unchanged, and the optical properties of the microcrystalline glass, such as transmittance and optical b value, are also basically unchanged.

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

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

[0219] In some preferred embodiments of the present invention, the fracture toughness of the strengthened glass-ceramics is greater than or equal to 1.00 MPa·m 1 / 2 , preferably greater than or equal to 1.20 MPa·m 1 / 2 , more preferably greater than or equal to 1.50 MPa m 1 / 2 In some embodiments, the fracture toughness may be 1.00 to 2.00 MPa·m 1 / 2 1.20~2.00MPa m 1 / 2 1.40~2.00MPa·m 1 / 2 1.50~2.00MPa·m 1 / 21.00~1.80MPa·m 1 / 2 1.00~1.60MPa·m 1 / 2 , 1.00~1.40MPa·m 1 / 2 or 1.00~1.20MPa·m 1 / 2 In some embodiments, the fracture toughness may be 1.00 MPa·m 1 / 2 , 1.20MPa·m 1 / 2 , 1.30MPa·m 1 / 2 , 1.40MPa

[0220] m 1 / 2 、1.50MPa·m 1 / 2 , 1.51MPa·m 1 / 2 、1.57MPa·m 1 / 2 , 1.60MPa·m 1 / 2 、1.64MPam 1 / 2 , 1.66MPa·m 1 / 2 , 1.70MPa·m 1 / 2 , 1.80MPa·m 1 / 2 , 1.90MPa·m 1 / 2 or 2.00MPam 1 / 2 , or the fracture toughness within the numerical range formed by any two of the above specific values ​​as endpoints. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges as long as the glass with the desired properties of the present invention can be obtained.

[0221] It should be understood that after chemical strengthening treatment, the Young's modulus of the glass-ceramics will increase appropriately, and the Young's modulus of the above-mentioned lithium-free transparent spinel glass-ceramics (i.e., the chemically strengthened glass-ceramics in the present invention) provided by the present invention is ≥100GPa, preferably ≥110GPa, and more preferably 114GPa≤Young's modulus≤140GPa. Therefore, the Young's modulus of the strengthened glass-ceramics is ≥100GPa, preferably ≥110GPa, and more preferably 114GPa≤Young's modulus≤140GPa.

[0222] In some preferred embodiments of the present invention, at a thickness of 0.7 mm, the tempered glass-ceramics of the present invention is subjected to a sandpaper drop resistance test using 120-grit sandpaper. The present invention uses at least 10 identical tempered glass-ceramics samples to perform a sandpaper drop resistance test to calculate the average sandpaper drop resistance height of the tempered glass-ceramics samples to obtain the average sandpaper drop resistance height of the tempered glass-ceramics; the average sandpaper drop resistance height of the tempered glass-ceramics is greater than 1.5 m, preferably greater than or equal to 1.80 m, more preferably 1.80 to 2.50 m, and more preferably 2.00 to 2.50 m. In some embodiments, the average sandpaper drop resistance height of the tempered glass-ceramics may be 1.80 m, 2.00 m, 2.10 m, 2.20 m, 2.30 m, 2.40 m, or 2.50 m, or the average sandpaper drop resistance height is within the numerical range formed by any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges may be combined with any other ranges, as long as the glass with the desired performance of the present invention can be obtained.

[0223] In some preferred embodiments of the present invention, at a thickness of 0.7 mm, the tempered glass-ceramics of the present invention is subjected to a 2.5 m drop test using 120-mesh sandpaper. If the glass sample does not break after falling, it is recorded as passed. The present invention uses at least 10 identical tempered glass-ceramics samples to perform a 2.5 m drop test to calculate the pass rate of the tempered glass-ceramics samples; the pass rate of the tempered glass-ceramics is ≥50%, preferably ≥60%, more preferably ≥70%, and more preferably, the pass rate is 60% to 100%. In some embodiments, the pass rate of the tempered glass-ceramics subjected to a 2.5 m drop test (120-mesh sandpaper) can be 60%, 70%, 80%, 90% or 100%, or the pass rate of the 2.5 m drop test (120-mesh sandpaper) is within the numerical range formed by any two of the above specific values ​​as endpoints. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the glass with the desired performance of the present invention can be obtained.

[0224] In the fourth aspect, the above-mentioned lithium-free transparent spinel glass-ceramics or the above-mentioned substrate glass for preparing the lithium-free transparent spinel glass-ceramics or the above-mentioned chemically strengthened glass provided by the present invention can be applied to mobile phone displays, tablet computer displays, handheld game consoles, electronic terminals, portable digital devices, vehicle central control screens, electronic whiteboard glass, smart home touch screens, vehicle windshields, aircraft windshields or aircraft windshields.

[0225] The following describes in detail how to prepare lithium-free transparent spinel glass-ceramics and the beneficial effects achieved through examples and comparative examples.

[0226] 1: Specific operation examples

[0227] Example 1

[0228] According to the component proportions of glass formula 1 of Example 1 in Table 1, various raw materials (conventional industrial raw materials) were configured in a platinum crucible, with a total amount of 1000 g of raw materials configured, and then mixed in a V-type mixer for 30 minutes. After mixing, 15 g of clarifier NaCl was added, and then the raw materials were transferred to a platinum crucible, and then melted in a 1650°C lifting furnace (lifting furnace model: SJF1750, manufacturer: Nanjing Boyuntong Instrument Technology Co., Ltd.) for 5 hours, and then poured into a stainless steel mold preheated at 300°C (usually preheated to 200-400°C) for molding and cooling, cooled to 900°C, and then placed in a 600°C annealing furnace for annealing for 24 hours, and then cooled to room temperature with the furnace to obtain the substrate glass.

[0229] The substrate glass was heat treated in a resistance furnace (equipment model: SLX1400-40, manufacturer: Shanghai Shengli Testing Instrument Co., Ltd.), and the heat treatment process (nucleation temperature / nucleation time, crystallization temperature / nucleation time, and heating rate during heat treatment) was carried out according to Table 1 to obtain a lithium-free transparent spinel microcrystalline glass sample brick. The microcrystalline glass sample brick was cut, CNC processed (computer nanometer control, i.e., CNC machine tool, the CNC equipment model used in the present invention is: RCG500S), and polished to obtain the smooth microcrystalline glass sheet. In the present invention, the specifications of the processed microcrystalline glass sheet are samples with a length, width, and thickness of 50mm×50mm×0.7mm.

[0230] The physical properties of the prepared glass-ceramics were tested according to the following method:

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

[0232] XRD test: The microcrystalline glass sheet is ground into glass fine powder with a grinding machine, and its particle size is less than 75μm, and then it is tested by an X-ray diffractometer (Shimadzu's XRD-6100) to obtain an XRD diffraction peak curve. The X-ray diffractometer used in the present invention is Shimadzu's XRD-6100, 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 XRD diffraction data is analyzed by JADE software to obtain the crystal phase of the sample.

[0233] Average grain size: Using the result data obtained from the XRD test, according to the Scherrer formula D = Kλ / (βcosθ), we can calculate the average grain size of the sample, where λ is the X-ray wavelength of 0.154056nm, β is the half-height width of the diffraction peak, K = 0.89, and θ is the Bragg diffraction angle. Specifically, the RAW file (diffraction spectrum) output by the XRD instrument is curve-fitted in the Jade software, and Jade outputs a fitting report. According to the angle 2θ value and 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 radians β = (FWHM / 180*3.14), the grain size of each diffraction peak is calculated by D = Kλ / (βcosθ) and then averaged to obtain the average grain size.

[0234] Testing method for crystal content / crystallinity: Import the X-ray diffractometer test result file (RAW format) into the X-ray diffraction data Rietveld refinement software (such as Gsas, Full prof, Maud), perform fitting and calculation, and then obtain the crystal content / crystallinity in the microcrystalline glass sample. The ratio of the fitted crystal phase peak area to the fitted total peak area is the crystal content, which is also referred to as crystallinity in the present invention.

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

[0236] Transmittance determination: Test according to GB / T 7962.12-2010 Test Method for Colorless Optical Glass Part 12: Spectral Transmittance. First, clean the glass-ceramic sample in an ultrasonic cleaner. The cleaning conditions are: cleaning time 5-10 minutes; cleaning agent used: commonly used detergent diluted 10 times; cleaning temperature: 45℃-65℃; cleaning frequency: 20KHZ-40KHZ. Then use a haze meter (Japan Konica Minolta spectrophotometer CM-3600A) to test its transmittance under different wavelengths of light.

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

[0238] Thickness of glass: Determined by micrometer test. It should be understood that in the thickness direction, the degree of ion exchange changes gradually from the surface to the center, and the total Na-K and / or Li-Na exchange amount generally does not exceed 1% of the total mass of the sample, and the difference in ion radius is at the pm level, so the expansion effect in the thickness direction is very slight, and it can be approximately considered that the thickness has basically not changed. That is, the thickness change of microcrystalline glass before and after chemical strengthening is very small and can be ignored.

[0239] Density determination: The density of the glass-ceramic sample is tested according to the principle of the “Archimedes drainage method”. The testing instrument used in the present invention is an ALFA MI RAGE electronic density balance SD-200L.

[0240] After completing the above-mentioned performance tests, the 0.7 mm thick microcrystalline glass sample obtained above is then chemically strengthened according to the mixed or single molten salt composition, ion exchange step temperature and ion exchange time conditions shown in Table 2 to obtain strengthened microcrystalline glass.

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

[0242] IOX (ion exchange): 480°C × 100% KNO3 × 24h (refers to exchange in 100wt% KNO3 molten salt at 480°C for 24h; similar expressions in this article 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 properties of the prepared strengthened glass-ceramics were tested according to the following method:

[0244] In the present invention, CS_50, |CT_CV|, |CT_AV|, and DOL_0 are tested using the stress meter SLP-2000 of Japan Luceo (Japan Orihara). The test conditions are: light source wavelength is 518nm, SOC=25.5 (nm / cm) / MPa, refractive index=1.60, and exposure time: 300usec. When testing CS_50, |CT_CV|, |CT_AV|, and DOL_0, it is necessary to first drip its special refractive liquid on the stress meter, then wipe the strengthened microcrystalline glass product clean, and place it on the test path to test its stress value. The refractive index of the refractive liquid used for SLP-2000 is 1.51. Unless otherwise specified, the above-mentioned test conditions are used when testing the stress values ​​in the embodiments and comparative examples of the present invention. It should be noted that when testing the stress values ​​of comparative examples 10-15, the photoelastic constant was set to 25.5 and the refractive index nd was 1.6; other conditions were the same as the above embodiment; when testing the stress value of comparative example 7, the photoelastic constant was set to 25.5 and the refractive index nd was 1.54; other conditions were the same as the above embodiment; when testing the stress value of comparative example 8, the photoelastic constant was set to 28.6 and the refractive index nd was 1.51; other conditions were the same as the above embodiment.

[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 invention, the CT_LD is calculated according to the following formula:

[0246]

[0247] Where t represents the thickness of the microcrystalline glass sheet (the glass thickness in the following embodiments and comparative examples of the present invention is 0.7 mm), in mm; DOL_0 represents the depth of the compressive stress layer, in μm; CT_AV represents the internal average tensile stress, and its absolute value is taken during calculation, in MPa. It should be understood that in the calculation formula of the tensile stress linear density, the data is substituted into the calculation according to the above unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation.

[0248] The calculation method of the exchange amount is: 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 invention, the K2O concentration on the surface of the strengthened microcrystalline glass is measured by an X-ray fluorescence spectrometer (XRF). The equipment model used is (Thermo Scientific ARL PERFORM'X), the target material is Rh (rhodium), the light tube voltage is 40kW, the current is 60mA, the collimator is 0.15, the crystal is Li F200, the detector is FPC, the test range is 29mm circle, and the analysis software is UniQuant standardless analysis.

[0250] Vickers hardness (HV) test: The chemically strengthened strengthened microcrystalline glass is made into a small piece with a length, width and thickness of 50mm*50mm*0.7mm, and a glass sample with a clean surface and no visible scratches, pits, cracks and other damage is selected as a test sample, and then the Vickers hardness is measured using a Vickers hardness tester. The Vickers hardness tester used in the present invention is a digital display small load Vickers hardness tester (Beijing Kewei Technology Co., Ltd., VTD405). Test conditions: load 300gf, load time 10s, the effectiveness of the indentation complies with the "GB / T37900-2019 Ultra-thin glass hardness and fracture toughness test method small load Vickers hardness indentation method" standard. Select 3 different positions on the same sample surface for measurement, and select the average value of the 3 measurement results as the Vickers hardness result of the glass sample to be tested.

[0251] Fracture toughness test: Test according to GB / T 37900-2019 Ultra-thin glass hardness and fracture toughness test method Small load Vickers hardness indentation method. Specifically, the indentation is prepared in the same way as the Vickers hardness measurement, and the crack length 2C1, 2C2 in the diagonal direction of the indentation is measured, and its maximum value 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 is calculated as the final result value of the sample.

[0252] Indentation fracture toughness calculation formula:

[0253] Where, IFR: Indentation fracture toughness, unit is MPa·m 1 / 2 ) ; E: elastic modulus of the specimen, in GPa; 2C1, 2C2: crack extension length in the diagonal direction of the indentation, in millimeter (mm); d1, d2: diagonal length of the indentation, in millimeter (mm); F: test load value, in Newton (N).

[0254] Test method for average drop resistance height: The average sandpaper drop resistance height refers to the average value of the sandpaper drop resistance height of each sample measured in multiple identical glass samples, which is used to characterize the drop resistance performance of microcrystalline glass. At least 10 identical glass samples are tested in each batch, and the average sandpaper drop resistance height is:

[0255]

[0256] Where n is the number of glass samples tested in each batch, hi is the sandpaper drop resistance height of a single sample test;

[0257] Among them, the test method for the sandpaper drop height of a single sample is:

[0258] Step 1: Paste 120-grit sandpaper on the lower surface of the 160g model machine, and place the model machine on the green figure LT-SKDL-CD drop machine;

[0259] Step 2: Place a glass sample to be tested with a length, width and thickness of 50mm*50mm*0.7mm directly under the model machine, with the glass sample facing the sandpaper. Make the model machine fall from a certain drop height to impact the glass sample directly under the model machine. If the glass sample does not break, the drop height of the model machine is increased according to a certain rule. For example, the drop height starts from 0.4m, and the sample is dropped once. If it does not break, increase the height by 0.1m each time and drop again until the glass sample breaks;

[0260] Step 3: The last drop height of the glass sample when it breaks is recorded as the anti-sandpaper drop height. For example, if the drop height when it breaks is 0.5m, the anti-sandpaper drop height of the sample is 0.4m.

[0261] Test method for 2.5m drop test pass rate: 2.5m drop test pass rate refers to the percentage of samples that pass after multiple identical glass samples are dropped from a height of 2.5m, divided by the total number of test samples. After the drop test, if the glass sample does not break, it is recorded as passed, otherwise it is recorded as failed; it is used to characterize the drop resistance of microcrystalline glass. Take at least 10 identical microcrystalline glass samples for each batch for testing.

[0262] Specifically, the method for a single sample to undergo a 2.5m drop test is as follows:

[0263] Step 1: Paste 120-grit sandpaper on the lower surface of the 160g model machine, and place the model machine on the green figure LT-SKDL-CD drop machine;

[0264] Step 2: Place a glass sample with a length, width and thickness of 50mm*50mm*0.7mm directly under the model machine, with the glass sample facing the sandpaper. Make the model machine fall once from a drop height of 2.5m to impact the glass sample directly under the model machine. If the glass sample does not break, it is recorded as passed, otherwise it is recorded as failed.

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

[0266] Examples 2-5 were operated under the same operating conditions as Example 1 and corresponding tests were carried out. Table 1 shows the glass formula compositions and heat treatment processes for preparing the substrate glass in Examples 1-5 and the performance parameters of the lithium-free transparent spinel glass-ceramics prepared therefrom; Table 2 shows the strengthening conditions of the lithium-free transparent spinel glass-ceramics in Examples 1-5 and the performance parameters of the prepared strengthened glass-ceramics.

[0267] Table 1 Base glass formula, melting state, heat treatment process and performance parameters of lithium-free transparent spinel glass-ceramics prepared in Examples 1-5

[0268]

[0269]

[0270] Table 2 Chemical strengthening conditions of lithium-free transparent spinel glass-ceramics in Examples 1-5 and performance parameters of the prepared strengthened glass-ceramics

[0271]

[0272]

[0273] Note: 1. Since the maximum time for the high temperature and high humidity failure test in the present invention is 360 hours (15 days), if the glass sample is taken out for observation after 360 hours, and the sample still has no 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 360 hours; 2. The surface K2O content in the table is the surface K2O concentration in the present invention.

[0274] Examples 6-10 were operated under the same operating conditions as Example 1 and were tested accordingly. Table 3 shows the glass formula compositions and heat treatment processes for preparing the substrate glass of Examples 6-10 and the performance parameters of the lithium-free transparent spinel glass-ceramics prepared therefrom; Table 4 shows the strengthening conditions of the lithium-free transparent spinel glass-ceramics in Examples 6-10 and the performance parameters of the prepared strengthened glass-ceramics.

[0275] Table 3 Base glass formula, melting state, heat treatment process and performance parameters of lithium-free transparent spinel glass-ceramics prepared by Examples 6-10

[0276]

[0277]

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

[0279]

[0280]

[0281] Note: 1. Since the maximum time for the high temperature and high humidity failure test in the present invention is 360 hours (15 days), if the glass sample is taken out for observation after 360 hours, and the sample still has no 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 360 hours; 2. The surface K2O content in the table is the surface K2O concentration in the present invention.

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

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

[0284]

[0285] Note: 1. Since the maximum time for the high temperature and high humidity failure test in the present invention is 360 hours (15 days), if the glass sample is taken out for observation after 360 hours, and the sample still has no 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 360 hours; 2. The surface K2O content in the table is the surface K2O concentration in the present invention.

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

[0287] Figure 6 The thermogravimetric analysis curve of the substrate glass of Example 1, wherein the thermogravimetric analysis test method is as follows: the substrate glass of Example 1 is ground and then passed through a 200-mesh sieve; the test conditions are: room temperature to 1100°C, 10°C / min heating rate; the test instrument is a Mettler-Toledo TGA / DSC3+ thermogravimetric and synchronous thermal analyzer. The obtained raw data is imported into the OrganicPro software to obtain the following Figure 6 The thermogravimetric analysis curve shown below shows the endothermic peak. Figure 6 It can be seen that the first endothermic peak is 735°C; upward is the exothermic peak, and the first exothermic peak is 848°C.

[0288] Figure 7 The XRD diffraction pattern of the lithium-free transparent spinel glass-ceramics of Example 1 is as follows: Figure 7 It can be seen that the main crystalline phase of the microcrystalline glass 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 is the transmittance curve of the lithium-free transparent spinel glass-ceramics of Example 5 under different wavelength conditions, Figure 8 It can be seen that the transmittance of the microcrystalline glass at a wavelength of 550 nm is greater than 90%.

[0290] From Table 1 and Table 3, combined Figure 1-Figure 3 It can be seen that when the substrate glass is prepared by the glass formula provided by the present invention, a substrate glass with good overall uniformity and transparency can be melted. At the same time, the substrate glass prepared by the present invention can be used to prepare microcrystalline glass with (Zn, Mg)Al2O4 as the main crystal phase and tetragonal zirconia as the secondary crystal phase, with high crystallinity and excellent optical properties under the condition of heat treatment temperature not exceeding 800°C. Specifically, the microcrystalline glass prepared by the present invention has a crystallinity of 37.52-40.41wt%, and a Young's modulus of more than 101GPa; at a wavelength of 550nm, the transmittance of the lithium-free transparent spinel microcrystalline glass prepared by the present invention is greater than or equal to 89%.

[0291] It can be seen from Tables 2, 4 and 5 that the lithium-free transparent spinel glass-ceramics of the present invention can be chemically strengthened to prepare strengthened glass-ceramics meeting specific stress characteristics, and the strengthened glass-ceramics have both excellent surface stress characteristics and excellent deep stress characteristics. Specifically, the strengthened glass-ceramics obtained by the present invention have |CT_AV| of 73.38-125.91MPa, |CT_CV| of 89.07-146.38MPa, DOL_0 of 108.69-132.50μm, all of which are greater than 0.13 times the glass thickness (0.7mm), CT_LD of 49620-80192MPa / mm, and CS _50 is 148.02-337.69MPa, and the higher |CT_AV|, |CT_CV|, DOL_0, CT_LD and CS_50 indicate that the strengthened glass-ceramics has excellent deep stress; at the same time, the K2O content on the surface of the strengthened glass-ceramics (that is, the surface K2O concentration) is 9.16%-15.21%. It should be understood that the K on the surface of the strengthened glass-ceramics mainly enters the glass surface through the chemical strengthening process and the salt bath exchange. The higher the surface K2O content, the more K-Na exchange occurs during the strengthening process, and the higher the surface compressive stress that the glass-ceramics can obtain, and the better the surface stress characteristics. The strengthened glass-ceramics that meet the specific stress characteristics prepared by the present invention are subjected to the sandpaper drop impact test, and it can be found that the average sandpaper drop height (120 mesh sandpaper) of the strengthened glass-ceramics of the present invention can be as high as 2m or more. At the same time, when the fixed-point height drop test of 2.5m is carried out, the pass rate of the strengthened glass-ceramics of the present invention 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 invention can reach more than 360 hours, indicating that the strengthened microcrystalline glass of the present invention has excellent weather resistance.

[0293] Comparative Examples 1-6 were operated and tested under the same operating conditions as Example 1. Table 6 shows the glass formula compositions of the substrate glasses prepared in Comparative Examples 1-6 and the melting states of the prepared substrate glasses.

[0294] Table 6 The glass formula composition of the substrate glass prepared in Comparative Examples 1-6 and the melting state of the prepared substrate glass

[0295]

[0296]

[0297] It can be seen from Table 6 that the B value in Comparative Example 1 is 0.89, which is greater than 0.8. Fig. 9As shown, the substrate glass is ceramicized after melting; 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 Fig.10 As shown, a large amount of unmelted material appears in the substrate glass after melting; in Comparative Example 3, the B2O3 content is relatively low and the A value is 0.21, which is greater than 0.18. Fig.11 As shown, white precipitate appears on the 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 precipitate appears on the substrate glass after melting; in Comparative Example 5, the MgO content is relatively high and the B value is 0.84, which is greater than 0.8, and the substrate glass is ceramicized after melting; in Comparative Example 6, the ZnO content is relatively high and the B value is 1.05, which is greater than 0.8, and the melting condition is as follows Fig.12 As shown, the base glass becomes ceramic after melting.

[0298] Comparative Examples 7-13 were operated under the same operating conditions as Example 1, and corresponding tests were performed. Table 7 shows the glass formula composition, melting state, heat treatment process and performance parameters of the prepared microcrystalline glass of Comparative Examples 7-13; Table 8 shows the chemical strengthening conditions of the microcrystalline glass prepared by Comparative Examples 7-12 and the performance parameters of the strengthened microcrystalline glass prepared by Comparative Examples 7-12. Among them, the glass formula of Comparative Examples 9 and Comparative Examples 13 is the same, that is, the prepared substrate glass is the same. Comparative Example 9 did not undergo nucleation treatment, but only one step of heat treatment, that is, direct temperature increase for crystallization treatment; Comparative Example 13 was crystallized at 800°C for 240min, but no crystals were precipitated, but phase separation occurred, and the transmittance decreased; Comparative Example 12 did not undergo a separate nucleation treatment; Comparative Examples 9 and 13 did not undergo ion strengthening treatment; Comparative Example 7 was strengthened under two conditions of 450°C×100%NaNO3×9h and 450°C×30%NaNO3+70%KNO3×8h, respectively.

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

[0300]

[0301]

[0302]

[0303] Table 8 Chemical strengthening conditions of the microcrystalline glass prepared in Comparative Examples 7-12 and performance parameters of the strengthened microcrystalline glass prepared therefrom

[0304]

[0305]

[0306]

[0307] Note: 1. Since the maximum time for the high temperature and high humidity failure test in the present invention is 360 hours (15 days), if the glass sample is taken out for observation after 360 hours, and the sample still has no 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 360 hours; 2. The surface K2O content in the table is the surface K2O concentration in the present invention.

[0308] It should be noted that the glass formula of Comparative Example 8 contains K2O, so 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 under the same operating conditions as Example 1 and were tested accordingly. Table 9 shows the glass formula composition, melting state, heat treatment process and performance parameters of the prepared glass-ceramics of the substrate glass of Comparative Examples 14-19; Table 10 shows the chemical strengthening conditions of the glass-ceramics prepared in Comparative Examples 14-16 and the performance parameters of the strengthened glass-ceramics prepared therefrom; in addition, Comparative Examples 17-19 were not subjected to strengthening treatment.

[0310] Table 9 Glass formula composition, melting state, heat treatment process and performance parameters of the prepared microcrystalline glass of the substrate glass of Comparative Examples 14-19

[0311]

[0312]

[0313] Table 10 Chemical strengthening conditions of the microcrystalline glass prepared in Comparative Examples 14-16 and properties of the strengthened microcrystalline glass prepared therefrom

[0314]

[0315] Note: 1. Since the maximum time for the high temperature and high humidity failure test in the present invention is 360 hours (15 days), if the glass sample is taken out for observation after 360 hours, and the sample still has no 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 360 hours; 2. The surface K2O content in the table is the surface K2O concentration in the present invention.

[0316] It can be seen from Tables 7 and 9 that in Comparative Example 9, the Na2O content is low. When the heat treatment temperature is lower than 800°C, no crystalline phase appears in the glass after heat treatment. When the heat treatment temperature reaches 900°C, mullite impurity phase appears after crystallization treatment. The transmittance of the finally obtained microcrystalline glass sample is low, showing devitrification; in Comparative Example 17, the MgO content is low, the average grain size in the microcrystalline glass sample after crystallization is too large, the transmittance is low, and the optical properties of the sample are poor; in Comparative Example 18, the ZnO content is low, the average grain size in the microcrystalline glass sample after crystallization is too large and impurity phase appears, the transmittance is low, and the optical properties of the sample are poor; in Comparative Example 19, the Li2O content is high, the microcrystalline glass sample after crystallization is severely fogged as a whole, the average grain size is too large, and impurity phase quartz SS appears, the transmittance is low, and the optical properties of the sample are extremely poor. Fig.13 shown.

[0317] It can be seen from Tables 8 and 10 that the Al2O3 content in Comparative Example 10 is low, and the stress level of the finally prepared strengthened microcrystalline glass is low, and the drop impact resistance is poor; the X value in Comparative Example 12 is 23.94%, the Y value is 44.77%, and the X value in Comparative Example 14 is 29.95%, and the Y value is 55.08%, which do not meet the conditions of X=30-50% and Y=60-80%, and the stress level of the strengthened microcrystalline glass prepared by the two is also poor. Specifically, when the drop test is performed using 120-mesh sandpaper, the average anti-sandpaper drop height of the strengthened microcrystalline glass in Comparative Examples 12 and Comparative Example 14 is less than 1.4m, which is much lower than the strengthened microcrystalline glass prepared in the embodiment of the present invention. At the same time, when the strengthened microcrystalline glass in Comparative Examples 12 and Comparative Example 14 is subjected to a 2.5m fixed-point height drop test, the glass is broken, and the pass rate is 0; the Y value in Comparative Example 15 does not meet the conditions of 60-80%, and the components contain BaO, A The content of l2O3 also does not meet the requirements of the present invention. The stress level of the strengthened microcrystalline glass obtained in Example 15 is poor. When the drop test is performed using 120-mesh sandpaper, the average sandpaper drop height is 0.6m, which is much lower than the strengthened microcrystalline glass obtained in the embodiment of the present invention. At the same time, when the drop test is performed from a fixed height of 2.5m, the test pass rate of the strengthened microcrystalline glass in Example 15 is also 0. The X value of Example 11 is 38.15%, and the Y value is 66.64%, but the component contains 2.21 mol% of BaO. The stress level obtained after strengthening is low, and the drop impact resistance is poor. The X value of Comparative Example 16 is 35.50% and the Y value is 59.10%. The X value meets the condition of 30-50%, and the Y value does not meet the condition of 60-80%. The deep stress level of the obtained strengthened microcrystalline glass is poor. When the drop test is carried out using 120-mesh sandpaper, the average sandpaper resistance drop height is 1.02m, which is much lower than the strengthened microcrystalline glass obtained in the embodiment of the present invention.

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

[0319] At the same time, since the present invention does not contain Li2O, the cost of raw materials is much lower than that of Comparative Examples 7 and 8, and its practical value is very considerable. Moreover, the substrate glass prepared by the glass formula of the present invention can obtain transparent microcrystalline glass with a main crystal phase of zinc-magnesium spinel solid solution and excellent optical properties and high intrinsic strength when the heat treatment temperature does not exceed 800°C. The difficulty of mass production of transparent spinel microcrystalline glass is greatly reduced, and the possibility of mass production is higher, which meets the development needs of energy conservation and carbon reduction in the industry.

[0320] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention 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 invention.

Claims

1. A strengthened glass-ceramic, characterized in that: The strengthened microcrystalline glass comprises a compressive stress layer and a tensile stress layer, and the tensile stress layer of the strengthened microcrystalline glass comprises the following oxides in mol%: SiO2 38.00-48.00%, Al2O3 25.50-30.00%, ZrO2 3.00-5.00%, MgO5.00-8.00%, ZnO 8.00-14.00%, Na2O 7.20-14.00%, B2O3 3.00-8.00%, K2O0-2.00% and Y2O3 0-1.00%; The tensile stress layer of the strengthened glass-ceramics contains substantially no Li2O, and the Li2O content is less than 0.01% in mol%. The composition of the tensile stress layer of the strengthened microcrystalline glass satisfies the following conditions, measured by the content expressed by molar percentage of each oxide in the composition of the tensile stress layer of the strengthened microcrystalline glass: The value of X is calculated based on the following formula, and the value of X is 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, and the value of Y is 60.00~80.00%, Y=(2.7×Na2O+1.8×(Al2O3-MgO-ZnO)) / (SiO2+Al2O3-MgO-ZnO+Na2O+K2O+B2O3).

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

3. The tempered glass-ceramics according to claim 1 or 2, characterized in that: The composition of the tensile stress layer of the strengthened glass-ceramics satisfies the following conditions, expressed in terms of the molar percentage of each oxide: A=0.65×Al2O3+3.5×ZrO2-0.8×Na2O-2.5×B2O3, wherein the value of A is less than or equal to 0.18, and the preferred value of A is 0.05 to 0.15; and / or, B = 3.8×Na2O+B2O3+4.5×MgO+6.0×ZnO-0.4×Al2O3-SiO2, wherein the value of B is less than or equal to 0.80, and preferably the value of B is 0.60 to 0.78; And / or, Al2O3-MgO-ZnO=8.00~15.00%.

4. The tempered glass-ceramics according to any one of claims 1 to 3, characterized in that: Measured by the content of each oxide expressed in molar percentage, the composition of the tensile stress layer of the strengthened microcrystalline glass satisfies: the X value is 34.00-46.00%, and / or the Y value is 60.00-75.00%.

5. The tempered glass-ceramics according to any one of claims 1 to 4, characterized in that: The tensile stress layer of the strengthened microcrystalline glass basically does not contain BaO, and the BaO content is less than 0.01% in mol%; and / or the tensile stress layer of the strengthened microcrystalline glass basically does not contain TiO2, and the TiO2 content is less than 0.01% in mol%.

6. The tempered glass-ceramics according to claim 1, characterized in that: The tensile stress layer of the strengthened glass-ceramics is composed of: The molar percentage of SiO2 is 38.00-44.00%; And / or, the molar percentage of Na2O is 7.20-12.00%; And / or, the molar percentage of Al2O3 is 25.50-28.00%; And / or, the molar percentage of MgO is 5.00-6.50%; And / or, the molar percentage of ZnO is 8.00-10.50%; And / or, the molar percentage of B2O3 is 3.00-6.50%.

7. The tempered glass-ceramics according to any one of claims 1 to 6, characterized in that: The main crystalline phase of the strengthened microcrystalline glass is (Zn, Mg)Al2O4, and the secondary crystalline phase includes tetragonal zirconia.

8. The tempered glass-ceramics according to any one of claims 1 to 7, characterized in that: The crystallinity of the strengthened glass-ceramics is ≥ 20.00wt%, preferably 20.00-50.00wt%, more preferably 30.00-50.00wt%, and further preferably 35.00-45.00wt%; and / or, In the strengthened glass-ceramics, the average grain size is ≤15.0 nm, preferably 1.0 to 15.0 nm, more preferably 1.0 to 10.0 nm, and further preferably 4.5 to 8.0 nm.

9. The tempered glass-ceramics according to any one of claims 1 to 8, characterized in that: The strengthened microcrystalline glass satisfies: the depth of the compressive stress layer DOL_0≥0.13t, preferably 0.22t≥DOL_0≥0.15t, where t is the thickness of the strengthened microcrystalline glass.

10. The tempered glass-ceramics according to any one of claims 1 to 9, characterized in that: The strengthened glass-ceramics satisfies: |CT_CV|≥80MPa, preferably 300MPa≥|CT_CV|≥80MPa, and further optionally, |CT_CV| is 89.07-146.38MPa.

11. The strengthened glass-ceramics according to any one of claims 1 to 10, characterized in that: The strengthened glass-ceramics satisfies: |CT_AV|≥70MPa, preferably 200MPa≥|CT_AV|≥70MPa, and further optionally, |CT_AV| is 73.38-125.91MPa.

12. The tempered glass-ceramics according to any one of claims 1 to 11, characterized in that: The strengthened microcrystalline glass satisfies: CS_50≥100MPa, preferably 500MPa≥CS_50≥140MPa, and further optionally, CS_50 is 148.02-337.69MPa.

13. The strengthened glass-ceramics according to any one of claims 1 to 12, characterized in that: The strengthened microcrystalline glass satisfies: CT_LD is 40000MPa / mm-85000MPa / mm, preferably 45000MPa / mm-85000MPa / mm, more preferably 48000MPa / mm-85000MPa / mm, and further optionally, CT_LD is 49620-80192MPa / mm.

14. The strengthened glass-ceramics according to any one of claims 1 to 13, characterized in that: The surface K2O concentration of the strengthened glass-ceramics is ≥9.00wt%, preferably 9.00-16.00wt%, and further optionally, the surface K2O concentration is 9.16%-15.21%.

15. The strengthened glass-ceramics according to any one of claims 1 to 14, characterized in that: The strengthened microcrystalline glass is transparent in the visible light range; preferably, at a thickness of 0.7 mm, for light of 550 nm wavelength, the transmittance of the strengthened microcrystalline glass is greater than or equal to 85%, preferably the transmittance is greater than or equal to 89%; And / or at a thickness of 0.7 mm, the absolute value of the optical b value of the strengthened microcrystalline glass is 0.20 to 1.50, preferably 0.50 to 1.

20.

16. The strengthened glass-ceramics according to any one of claims 1 to 15, characterized in that: The Vickers hardness of the reinforced microcrystalline glass is 700-900 kgf / mm 2 .

17. The strengthened glass-ceramics according to any one of claims 1 to 16, characterized in that: The fracture toughness of the strengthened microcrystalline glass is greater than or equal to 1.00 MPa·m 1 / 2 , preferably greater than or equal to 1.20 MPa·m 1 / 2 , more preferably greater than or equal to 1.50 MPa·m 1 / 2 .

18. The strengthened glass-ceramics according to any one of claims 1 to 17, characterized in that: The Young's modulus of the strengthened microcrystalline glass is ≥100 GPa, preferably ≥110 GPa, and more preferably 114 GPa≤Young's modulus≤140 GPa.

19. The strengthened glass-ceramics according to any one of claims 1 to 18, characterized in that: When the thickness is 0.7 mm, the tempered glass-ceramics is subjected to a sandpaper drop resistance test using 120-mesh sandpaper. The average sandpaper drop resistance height of the tempered glass-ceramics is greater than 1.5 m, preferably greater than or equal to 1.80 m, further preferably 1.80 to 2.50 m, and more preferably 2.00 to 2.50 m.

20. The strengthened glass-ceramics according to any one of claims 1 to 19, characterized in that: When the thickness is 0.7 mm, the strengthened microcrystalline glass is subjected to a 2.5 m drop test using 120-mesh sandpaper, and the pass rate of the strengthened microcrystalline glass is ≥50%, preferably ≥60%, more preferably ≥70%, and more preferably, the pass rate is 60% to 100%.

21. The strengthened glass-ceramics according to any one of claims 1 to 20, characterized in that: The thickness t of the strengthened microcrystalline glass is 0.2-5.0 mm, optionally 0.3-2.0 mm, and further optionally 0.4-1.5 mm.

22. The strengthened glass-ceramics according to claim 1, characterized in that: 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%.

23. The strengthened glass-ceramics according to claim 1, characterized in that: 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%.

24. The strengthened glass-ceramics according to claim 3, characterized in that: 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%.

25. An electronic terminal, characterized in that: The electronic terminal comprises the strengthened glass-ceramic according to any one of claims 1 to 24.

26. The electronic terminal according to claim 25, characterized in that: The electronic terminals include mobile phone display screens, tablet computer display screens, handheld game consoles, portable digital devices, vehicle-mounted central control screens, electronic whiteboard glass, and smart home touch screens.

27. Use of the tempered micro-ceramic glass according to any one of claims 1 to 26 in mobile phone displays, tablet computer displays, handheld game consoles, electronic terminals, portable digital devices, vehicle central control screens, electronic whiteboard glass, smart home touch screens, vehicle windshields, aircraft windshields or aircraft windshields.

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