Precursor glass, glass ceramic, chemically strengthened glass ceramic and glass preparation method

Abstract

The invention provides precursor glass, microcrystalline glass, chemically strengthened microcrystalline glass and a glass preparation method, and relates to the technical field of materials, the precursor glass meets the following relational expressions: delta = a * nRO + b * (nNa2O + nK2O) + c * nLi2O), eta = 12.5 / (0.57 + 4.58 * i0.55929), and 0.35 < = delta / eta < = 0.69; wherein delta represents the ion activity degree of each ion in the glass, eta represents the correlation index of the kinetic energy of thermal motion of oxide molecules in the glass and a characteristic temperature point, n represents the molar percentage content corresponding to each oxide, a, b and c are constants, i is a characteristic temperature coefficient, a is more than 1.1 and less than 1.9, b is more than 1.5 and less than 2.7, c is more than 1.1 and less than 1.6, and i is more than 5.29 and less than 9.73. According to the present invention, the crystallization tendency of the glass is represented by the delta / eta, the value range is optimally designed, such that the glass viscosity is suitable for low temperature crystallization, the impure phase control and the target crystal phase crystallinity are considered, and the optical property and the mechanical property of the glass are improved.

Description

Technical Field

[0001] The present application relates to the field of material technology, and in particular to the field of glass-ceramics technology. Specifically, the present application discloses a precursor glass, glass-ceramics, chemically strengthened glass-ceramics, and a glass preparation method. Background Art

[0002] Glass-ceramics contain tiny crystals that are inherently strong and can inhibit crack propagation when impacted. This gives glass-ceramics superior mechanical properties compared to ordinary glass, resulting in superior drop resistance. Glass-ceramics has experienced rapid development since the turn of the century, with particular growth in recent years for mobile phone covers. Due to its high strength and drop resistance, glass-ceramics has become increasingly popular in the consumer electronics market.

[0003] In the process of producing microcrystalline glass, the precursor glass is usually required to have a strong tendency to crystallize in order to ensure that the glass is uniformly crystallized as a whole. This leads to the easy generation of some impurities such as lithium metasilicate and spodumene, and these impurities have different degrees of damage to the mechanical properties and optical properties of microcrystalline glass, but are difficult to remove in the actual production process. These impurities may be generated in the glass melting, heat treatment process, and strengthening process. The main reason is that the crystal structure of these impurities is closely related to the structure of glass and microcrystalline glass, such as high-temperature phase transition and similar structure, and it is difficult to completely eliminate them. At present, the relevant technology generally uses a relatively mild heat treatment process (shorter heat treatment time and / or lower heat treatment temperature) to reduce the generation of impurities, that is, by losing crystallinity in exchange for a purer target crystal phase, but the optical and mechanical properties of microcrystalline glass cannot be effectively guaranteed.

[0004] It is important to note that the techniques described in this section are not necessarily those that have been previously conceived or employed. Unless otherwise indicated, it should not be assumed that any technique described in this section is prior art simply because it is included in this section. Similarly, unless otherwise indicated, the issues mentioned in this section should not be considered to have been recognized as prior art. Summary of the Invention

[0005] The present application provides a precursor glass, microcrystalline glass, chemically strengthened microcrystalline glass and a glass preparation method, aiming to solve at least one of the problems in the related art to a certain extent.

[0006] In a first aspect, the present application provides a precursor glass suitable for low-temperature crystallization treatment, wherein the precursor glass satisfies the following relationship:

[0007] δ=a*n RO +b*(n Na2O +n K2O )+c*nLi2O ,

[0008] η=12.5 / (0.57+4.58*i^0.55929)

[0009] 0.35≤δ / η≤0.69;

[0010] Among them, δ represents the ionic activity of each ion in the glass, η represents the correlation index between the kinetic energy of thermal motion of oxide molecules in the glass and the characteristic temperature point, n represents the molar percentage content of each oxide, a, b, and c are constants, and i is the characteristic temperature coefficient, 1.1<a<1.9, 1.5<b<2.7, 1.1<c<1.6, 5.29<i<9.73; among them, RO represents alkaline earth metal oxide, a is the calculation coefficient corresponding to alkaline earth metal oxide, b is the calculation coefficient corresponding to sodium oxide and potassium oxide, and c is the calculation coefficient corresponding to lithium oxide.

[0011] Optionally, the precursor glass further satisfies the following relationship:

[0012] ε=A*n SiO2 +F*n B2O3 +C*n Al2O3 +D*n P2O5 +E*n RO +F*n R2O ,

[0013] 21.3≤ε≤25.6;

[0014] Among them, ε represents the degree of atomic stacking, n represents the molar percentage content of each oxide, A, B, C, D, E, and F are constants, A = 26.1 to 28.3, B = 18.3 to 27.3, C = 40.2 to 42.7, D ​​= 56.1 to 63.7, E = 12.2 to 22.6, and F = 10.9 to 36.2.

[0015] Optionally, the precursor glass further satisfies the following relationship:

[0016] ε=A*n SiO2 +B*n B2O3 +C*n Al2O3 +D*n P2O5 +12.5*n MgO +14.4*n CaO +11.2*n Li2O +20.2*n Na2O +34*n K2O , where 22.1≤ε≤24.5.

[0017] Optionally, the precursor glass comprises, in mole percentage, the following components:

[0018] SiO2 greater than or equal to 63% and less than or equal to 72%;

[0019] 1.5% or more and 6% or less of Al2O3;

[0020] 16% or more and 26.8% or less of Li2O;

[0021] greater than or equal to 0 and less than or equal to 6.5% Na2O;

[0022] K2O greater than or equal to 0 and less than or equal to 4%;

[0023] 0.3% or more and 2.5% or less of P2O5;

[0024] ZrO2 greater than or equal to 0 and less than or equal to 5%;

[0025] RO is greater than or equal to 0 and less than or equal to 5.3%, and RO includes at least one of CaO, MgO, ZnO, and BaO;

[0026] Greater than or equal to 0 and less than or equal to 1% of clarifier.

[0027] Optionally, the components of the precursor glass, expressed in molar percentage, further include: greater than or equal to 0 and less than or equal to 4.8% B2O3; and / or greater than or equal to 0% and less than or equal to 4% TiO2; and / or greater than or equal to 0 and less than or equal to 0.5% La2O3.

[0028] Optionally, the precursor glass comprises, in mole percentage, Al2O3 in an amount greater than or equal to 1.5% and less than or equal to 5.5%.

[0029] Optionally, the precursor glass comprises, in molar percentage, Al2O3 in an amount greater than or equal to 2% and less than or equal to 4.2%; or Al2O3 in an amount greater than or equal to 3.5% and less than or equal to 5.2%.

[0030] Optionally, the precursor glass comprises, in mole percentage, P2O5 greater than or equal to 0 and less than or equal to 2.2%.

[0031] Optionally, the precursor glass comprises, in molar percentage, Li2O greater than or equal to 18% and less than or equal to 26.8%, Na2O greater than or equal to 0 and less than or equal to 6.5%, and K2O greater than or equal to 0 and less than or equal to 4%.

[0032] Optionally, the precursor glass comprises, in molar percentage, Li2O greater than or equal to 22.2% and less than or equal to 25.8%, Na2O greater than or equal to 0 and less than or equal to 3.1%, and K2O greater than or equal to 0 and less than or equal to 1.2%.

[0033] Optionally, the precursor glass comprises, in molar percentage, Li2O greater than or equal to 16% and less than or equal to 24%, Na2O greater than or equal to 0 and less than or equal to 5%, and K2O greater than or equal to 0 and less than or equal to 4%.

[0034] Optionally, the precursor glass comprises, in molar percentage, Li2O greater than or equal to 20.5% and less than or equal to 23.5%, Na2O greater than or equal to 0 and less than or equal to 2%, and K2O greater than or equal to 0 and less than or equal to 0.5%.

[0035] Optionally, the precursor glass also includes at least one of Y2O3, La2O3, Nb2O5, Ta2O5, HfO2, and Bi2O3.

[0036] Optionally, the components of the precursor glass, expressed in mole percentage, satisfy at least one of the following relationships:

[0037] 4≤n Li2O / (n Na2O +n K2O )≤17;

[0038] 6≤n Li2O / (n CaO +n MgO +n ZnO )≤18;

[0039] 0.24≤n Li2O / (n SiO2 +n Al2O3 )≤0.38;

[0040] Li2O, Na2O, and K2O are all alkali metal oxides. By adding alkali metal oxides in combination, a mixed alkali effect can be formed, which can improve the crosslinking density of the glass network, chemical stability and other properties, and significantly improve the stability of micro-glass products. Li2O / (Na2O+K2O) needs to meet a certain value range. If the ratio of (Na2O+K2O) is too low, the mixed alkali effect cannot be formed. If the ratio of (Na2O+K2O) is too high, it will affect the formation ratio and formation speed of lithium crystals in the glass; (CaO+MgO+ZnO) has a higher field strength, It can enhance the mechanical properties of glass, such as elastic modulus and Vickers hardness. If the ratio of (CaO+MgO+ZnO) is too low, the beneficial effect of enhancing the mechanical properties cannot be achieved. If it is too high, it will promote the malignant growth of crystals and make it difficult to form microcrystals. (SiO2+Al2O3) is the main network former in glass, which plays a decisive role in the viscosity of glass and the network crosslinking density. If the ratio of (SiO2+Al2O3) is too low, controllable crystallization cannot be formed under suitable viscosity and temperature conditions. If the ratio is too high, it will affect the crystallinity and crystal size of the glass, and at the same time make the glass viscosity too high, which is not conducive to production.

[0041] A second aspect of the present application provides a glass-ceramic, which is obtained by heat treating the precursor glass described in the first aspect.

[0042] Optionally, the lower limit crystallization temperature of the glass-ceramics is 553-639°C, and the upper limit crystallization temperature is 989-1123°C.

[0043] Optionally, the crystal phase of the glass-ceramics is lithium disilicate, and the lithium disilicate crystal phase meets the following indicators: an average grain size is less than or equal to 38 to 45.7 nm, and a crystallinity is greater than or equal to 56.38%.

[0044] Optionally, the lithium disilicate crystalline phase meets the following indicators: the size of 98% of the grains in the overall crystalline phase is less than or equal to 60 nm, the size of 95% of the grains in the overall crystalline phase is less than or equal to 55 nm, and the size of 80% of the grains in the overall crystalline phase is less than or equal to 50 nm; the crystallinity is greater than or equal to 61.22%.

[0045] Optionally, the glass-ceramics meets at least one of the following performance indicators: Vickers hardness greater than or equal to 727 kgf / mm 2 , fracture toughness greater than or equal to 1.01Mpa·m 1 / 2 , Young's modulus greater than or equal to 99GPa, shear modulus greater than or equal to 40GPa, |B| value less than or equal to 0.74% when the thickness is 0.55mm, haze less than or equal to 0.14%, and transmittance relative to visible light with a wavelength of 550nm greater than or equal to 91%.

[0046] A third aspect of the present application provides a chemically strengthened glass-ceramics, which is obtained by sequentially subjecting the precursor glass of the first aspect to heat treatment and ion exchange treatment.

[0047] Optionally, the chemically strengthened glass-ceramics meets at least one of the following performance indicators: Vickers hardness greater than or equal to 655 kgf / mm 2 , fracture toughness greater than or equal to 1.2Mpa·m 1 / 2 , Young's modulus greater than or equal to 98.38 GPa, shear modulus greater than or equal to 39.35 GPa, |B| value less than or equal to 0.74% when the thickness is 0.55 mm, haze less than or equal to 0.13%, transmittance relative to visible light with a wavelength of 550 nm is greater than or equal to 91%, the nine-point drop test height based on a 32g steel ball when the thickness is 0.55 mm is 980~1290 mm, the maximum bending strength is 1052~1200 MPa, the whole machine drop test height based on 80 mesh sandpaper is 850~1020 mm, and the whole machine drop test height based on 180 mesh sandpaper is 1200~1600 mm.

[0048] A fourth aspect of the present application provides a glass preparation method, comprising:

[0049] The raw materials are mixed evenly according to the glass formula, melted at a preset melting temperature and melting time, and then formed and annealed to obtain a precursor glass;

[0050] heat-treating the precursor glass to obtain glass-ceramics;

[0051] Wherein, the precursor glass satisfies the following relationship:

[0052] δ=a*n RO +b*(n Na2O +n K2O )+c*n Li2O ),

[0053] η=12.5 / (0.57+4.58*i^0.55929),

[0054] 0.35≤δ / η≤0.69;

[0055] Among them, δ represents the ionic activity of each ion in the glass, η represents the correlation index between the kinetic energy of thermal motion of oxide molecules in the glass and the characteristic temperature point, n represents the molar percentage content of each oxide, a, b, and c are constants, and i is the characteristic temperature coefficient, which is specifically stated in the specification as 1.1<a<1.9, 1.5<b<2.7, 1.1<c<1.6, and 5.29<i<9.73.

[0056] Optionally, the heat treatment of the precursor glass includes: placing the precursor glass in a crystallization furnace, heating it to 500-610°C at a heating rate greater than or equal to 6°C / min, and then keeping it warm for 200-300 minutes, then heating it to 655-800°C at a heating rate greater than or equal to 6°C / min, and then keeping it warm for 60-120 minutes, and finally cooling it at a cooling rate less than or equal to 2°C / min.

[0057] Optionally, the heat treatment of the precursor glass includes: placing the precursor glass in a crystallization furnace, heating it to 560-590°C at a heating rate of 8-12°C / min and keeping it warm for 220-250 minutes, then heating it to 750-790°C at a heating rate of 8-12°C / min and keeping it warm for 70-90 minutes, and finally cooling it at a cooling rate less than or equal to 2°C / min.

[0058] Optionally, the glass preparation method further includes: performing hot bending treatment on the microcrystalline glass through a hot bending workstation; wherein the pressure of the hot bending workstation is 0.7 to 1.1 MPa, and the operating time of a single workstation is 70 to 110 seconds.

[0059] Optionally, the hot bending treatment needs to go through four preheating workstations, three hot pressing workstations and two cooling workstations; wherein, the operating temperature of the first preheating workstation is 430-470°C, the operating temperature of the second preheating workstation is 530-570°C, the operating temperature of the third preheating workstation is 630-670°C, the operating temperature of the fourth preheating workstation is 710-730°C, the operating temperature of the first hot pressing workstation is 740-760°C, the operating temperature of the second hot pressing workstation is 740-760°C, the operating temperature of the third hot pressing workstation is 580-620°C, the operating temperature of the first cooling workstation is 430-470°C, and the operating temperature of the second cooling workstation is 280-320°C.

[0060] Optionally, the glass preparation method also includes: immersing the microcrystalline glass in a chemically strengthened salt bath for ion exchange treatment to obtain chemically strengthened microcrystalline glass; wherein the chemically strengthened salt bath includes, by mass percentage: greater than or equal to 9.99% and less than or equal to 39.99% KNO3, greater than or equal to 59.99 and less than or equal to 89.99% NaNO3, and greater than or equal to 0.03% and less than or equal to 0.1% LiNO3.

[0061] Optionally, the temperature of the chemical strengthening salt bath is 460-490° C., and the duration of the ion exchange treatment is 4-10 hours.

[0062] As can be seen from the above, according to the precursor glass, microcrystalline glass, chemically strengthened microcrystalline glass and glass preparation method provided by the present application, the precursor glass satisfies the following relationship: δ = a*n RO +b*(n Na2O +n K2O )+c*n Li2O ), 0.35≤δ / η≤0.69;. δ represents the ionic activity of each ion in the glass, η represents the correlation index between the kinetic energy of thermal motion of oxide molecules in the glass and the characteristic temperature point, n represents the molar percentage content of each oxide, a, b, and c are constants, and i is the characteristic temperature coefficient, 1.1<a<1.9, 1.5<b<2.7, 1.1<c<1.6, 5.29<i<9.73; alkali metals and alkaline earth metals have a significant effect on increasing the crystallization tendency of glass, among which Na2O and K2O have a particularly prominent effect on increasing the crystallization tendency of glass. This is because their small ionic radius makes them more easily attracted to high-field-strength ions under suitable temperature conditions. By introducing the δ calculation formula, oxides with different effects in the glass can be classified and calculated, and different factors affecting the crystallization tendency can be comprehensively evaluated to describe the relationship between electric field strength and ion migration of different oxides in the glass. The η calculation formula is then introduced to correlate the relationship between the kinetic energy of the thermal motion of glass oxide molecules and the characteristic temperature point with the above-mentioned crystallization intensity, and to comprehensively evaluate the crystallization tendency of crystallization at lower temperatures.

[0063] The crystallization tendency of the glass is characterized by describing the ionic activity of the glass using δ / η. Setting the value of δ / η within a specific range can ensure that the glass viscosity is suitable for low-temperature crystallization. It is worth mentioning that the suitability for low-temperature crystallization mentioned in this embodiment means that the crystallization temperature required in the embodiment of the present application is lower than the thermoforming and hot processing temperature, while still ensuring high crystallinity. Due to the relatively low crystallization temperature, the formation of impurity phases can be effectively controlled. By optimizing the range of its value, the present application can ensure that the glass viscosity is suitable for low-temperature crystallization, taking into account both impurity phase control and the crystallinity of the target crystalline phase, thereby improving the optical and mechanical properties of the glass.

[0064] It should be understood that the content described in this section is not intended to identify the key or important features of the present application, nor is it intended to limit the scope of the present application. The further effects of the above non-conventional optional manner will be described below in conjunction with specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The accompanying drawings illustrate exemplary embodiments and constitute a part of the specification. Together with the description of the specification, they serve to explain exemplary implementations of the embodiments. The drawings are shown for illustrative purposes only and do not limit the scope of the claims. Throughout the drawings, the same reference numerals designate similar, but not necessarily identical, elements.

[0066] Figure 1 The DSC test curve of the glass-ceramics corresponding to Example 4 provided in this application;

[0067] Figure 2 This is an XRD test graph of the glass-ceramics corresponding to Example 4 provided in this application;

[0068] Figure 3 This is a scanning electron microscope image of the glass-ceramics corresponding to Example 4 provided in this application;

[0069] Figure 4 The viscosity-temperature curve of the microcrystalline glass corresponding to Example 4 provided in this application. DETAILED DESCRIPTION

[0070] In order to make the purpose, features, and advantages of the invention of this application more obvious and easy to understand, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0071] In the description of the embodiments of the present application, the term "multiple" means two or more, unless otherwise clearly and specifically limited; the term "including" indicates the presence of the described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections; the term "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may include the existence of A alone, the existence of A and B at the same time, and the existence of B alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship; the term "about" means that the content, size, parameter, etc. are not and do not need to be exact. If necessary, they can be approximate or higher or lower. Generally speaking, regardless of whether there is an explicit description, the content, size, parameter, etc. should be "about" or "approximate"; the terms "preferably" and "optional" are not used to limit the scope of the present application, nor do they mean that certain technical features are critical or indispensable to the implementation methods of the present application. Instead, they should be understood as merely indicating specific aspects of the embodiments of the present application.

[0072] Unless otherwise indicated in specific circumstances, the numerical ranges described in the examples of the present application are intended to include the endpoints of the numerical range and all integers and fractions within the range. When an amount, solubility or other parameter is described in the form of a preferred range or preferred value, it should be understood that it is equivalent to revealing any range by combining any preferred range with a preferred range, a preferred value with a preferred value, or a preferred range with a preferred value, without considering whether such pairwise combinations are specifically explained in the examples.

[0073] Unless otherwise specified in specific circumstances, the component contents described in the examples of the present application are expressed in molar percentage (mol%).

[0074] Explanation of terms

[0075] Precursor glass: refers to glass that has not been subjected to nucleation, crystallization and strengthening treatments.

[0076] Glass-ceramics, also known as glass ceramics, are a type of solid composite material consisting of both a glass phase and a microcrystalline phase, produced by targeted, controlled heat treatment of a precursor glass. The microcrystalline phase is also referred to as the crystalline phase, crystallized phase, or crystalline phase in other materials.

[0077] Chemically strengthened glass-ceramics refers to the solid composite material obtained by chemically strengthening glass-ceramics. It should be understood that during high-temperature chemical strengthening or high-temperature ion exchange processes, alkali metal ions with large ionic radii (such as potassium and sodium ions) in the salt bath or molten salt (molten salt) will replace alkali metal ions with smaller ionic radii (such as sodium and lithium ions) in the glass-ceramics, resulting in a volume difference between the exchanged ions. This generates a compressive stress from high to low in the surface layer of the glass-ceramics, hindering and delaying the expansion of microcracks, thereby improving the mechanical strength of the glass-ceramics.

[0078] Nucleation temperature: refers to the temperature at which crystal nuclei are formed.

[0079] Crystallization temperature: refers to the temperature at which the target crystal growth rate can be controlled.

[0080] Transmittance: When light of a certain wavelength hits the glass surface, the light will be reflected, absorbed and transmitted. The ratio of the intensity of the transmitted part to the intensity of the incident light is the transmittance.

[0081] In the present invention, the average transmittance of glass-ceramics in the visible light range refers to the average transmittance of the glass-ceramics measured at wavelengths between 360 nm and 740 nm. The average transmittance of the glass-ceramics at wavelengths between 360 nm and 740 nm was measured using a Konica Minolta CM-3600A spectrophotometer.

[0082] Crystallinity: refers to the percentage of the total mass of the crystalline phase / crystals in the microcrystalline glass to the mass of the microcrystalline glass.

[0083] Haze (C) refers to the percentage of the transmitted light intensity that deviates from the incident light by more than 2.5° to the total transmitted light intensity. The haze in this invention is the haze value measured using a Konica Minolta CM-3600A spectrophotometer under standard C light source.

[0084] L value: In the present invention, the L value is the specular reflection light (SCI) L value, which indicates the brightness of the material. A positive L value indicates whiteness, and a negative L value indicates blackness.

[0085] a value: In the present invention, the a value is the specular reflection light (SCI) a value, which represents the red and green values ​​of the material. A positive a value indicates that the material is reddish, and a negative a value indicates that the material is greenish.

[0086] b value: In the present invention, the b value is the specular reflection light (SCI) b value, which represents the yellow-blue value of the material. A positive b value indicates that the material is yellowish, and a negative b value indicates that the material is blue.

[0087] 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. Sandland of the United Kingdom at Vickers Ltd in 1921.

[0088] In the present invention, fracture toughness refers to the impedance value displayed by the material when a crack or crack-like defect occurs in a specimen or component and the material no longer fractures rapidly with increasing load, that is, when so-called unstable fracture occurs.

[0089] In the present invention, CS_50 refers to the compressive stress value at a depth of 50 μm from the glass surface.

[0090] In the present invention, |CT_CV| refers to the absolute value of the maximum value of the tensile stress, specifically refers to the absolute value of the maximum value of all tensile stresses in the tensile stress layer.

[0091] 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.

[0092] 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.

[0093] In a first aspect, the present invention provides a strengthened glass-ceramic with the following crystallization characteristics and stress characteristics in order to make the strengthened glass-ceramic have excellent drop resistance.

[0094] Typical drop impacts are puncture-type failures. Sharp particles can easily penetrate the glass surface CS, creating a 30-50 micron deep pit. Cracks then form at this pit, extending through the compressive stress zone and shattering the glass. CS_50 represents the compressive stress at a depth of 50 microns. A higher stress at this point inhibits crack formation at the pit, while a deeper DOL-0 indicates a larger crack propagation barrier. CT-CV represents the point of maximum tensile stress, similar to the average tensile stress value of CT-AV. It indirectly indicates the magnitude of deep compressive stress. Better stress performance indicates less crack propagation.

[0095] Drop test: A glass piece is attached to a 200g counterweight steel sheet to simulate the entire device falling.

[0096] The substrate glass was heat treated in a resistance furnace. Following heat treatment procedures (nucleation temperature / nucleation time, crystallization temperature / nucleation time, and heating rate during the heat treatment process), chemically strengthened glass-ceramics were obtained. The glass-ceramics were then cut, CNC machined (using a computer numerical control machine, RCG500S), and polished to obtain the mirror-smooth glass-ceramics sheets.

[0097] The physical properties of the prepared glass-ceramics were tested according to the following method:

[0098] Upper and lower limits of crystallization: Use an Orton GTF-MD-16 gradient furnace for testing. Place the glass strip on the ceramic tube of the Orton gradient furnace, set the heating parameters, and after the furnace cools down, remove the sample and record the corresponding position. Since the temperature at one end of the sample is low and the other end is high, the temperature can be accurately determined. Refer to the standard ASTM E 228-17.

[0099] Vickers Hardness Test: A diamond Vickers indenter is pressed into the specimen surface with a load ranging from 1.916N to 49.03N to form an indentation. The load is divided by the surface area of ​​the indentation, calculated from the average diagonal length of the indentation. Refer to standard GBT37900-2019.

[0100] Fracture toughness test: A diamond Vickers indenter is pressed into the specimen surface with a load ranging from 1.916N to 49.03N to form an indentation. Pre-cracks are generated at the four vertices of the indentation. The value is calculated based on the load and the indentation crack propagation length, referring to the standard GBT 37900-2019.

[0101] Young's modulus test: The Young's modulus of the sample was obtained by ultrasonic testing using the UMS-100 ultrasonic material characterization system, with reference to the standard GBT 37780-2019.

[0102] XRD testing: The glass-ceramics were ground into a fine glass powder with a particle size of less than 75 μm using a mill. The powder was then tested using an X-ray diffractometer (Shimadzu XRD-6100) to obtain an XRD diffraction peak curve. The X-ray diffractometer used in the present invention was a Shimadzu XRD-6100, with a copper target, an incident angle range of 2θ = 10-80°, a scan speed of 0.2° / min, an operating voltage of 40 kV, and an operating current of 30 mA. The XRD diffraction data were then analyzed using JADE software to determine the crystalline phase of the sample.

[0103] Average grain size: The average grain size of the sample can be calculated using the result data obtained from the XRD test according to the Scherrer formula D = Kλ / (βcosθ), where λ is the X-ray wavelength, λ is 0.154056nm, β is the half-maximum width of the diffraction peak, and θ is the Bragg diffraction angle. Specifically, the RAW file (diffraction pattern) 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-maximum width of the diffraction peak) corresponding to each diffraction peak in the fitting report, the Peak FWHM value is converted to radians β = (FWHM / 180*3.14), and the grain size of each diffraction peak is calculated by D = Kλ / (βcosθ) and then averaged to obtain the average grain size. 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, Fullprof, Maud, Topas), 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.

[0104] 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.

[0105] Transmittance was measured according to the standard "GB / T 7962.12-2010 Test Methods for Colorless Optical Glass - Part 12: Spectral Transmittance." The glass-ceramic sample was first cleaned in an ultrasonic cleaner using the following cleaning conditions: 5-10 minutes; detergent: a 10-fold dilution of standard dishwashing liquid; temperature: 45°C-65°C; frequency: 20kHz-40kHz. The transmittance was then measured using a haze meter (Konica Minolta CM-3600A Spectrophotometer, Japan) at different wavelengths.

[0106] The transmittance of the sample under 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.

[0107] Glass thickness: Determined by micrometer testing. It should be understood that the degree of ion exchange varies gradually from the surface to the center of the glass through the thickness. The total Na-K and / or Li-Na exchange typically does not exceed 1% of the sample's mass, and the difference in ion radius is typically on the order of micrometers. Therefore, the expansion effect through the thickness is minimal, and the thickness can be considered essentially unchanged. In other words, the change in thickness of the glass-ceramic before and after chemical strengthening is negligible and very small.

[0108] Density determination: The density of the glass-ceramic sample was measured using the "Archimedes drainage method." The test instrument used in this invention is an ALFA MIRAGE electronic density balance SD-200. To at least partially address the problem in related art whereby crystallinity is sacrificed in exchange for a purer target crystalline phase, resulting in ineffective guarantees of the optical and mechanical properties of the glass-ceramic, one embodiment of this application provides a precursor glass suitable for low-temperature crystallization. The precursor glass can be understood as plain glass or glass stock obtained by melting glass raw materials. The precursor glass satisfies the following relationship:

[0109] δ=a*n RO +b*(n Na2O +n K2O )+c*n Li2O ,

[0110] η=12.5 / (0.57+4.58*i^0.55929)

[0111] 0.35≤δ / η≤0.69;

[0112] Among them, δ represents the ionic activity of each ion in the glass, η represents the correlation index between the kinetic energy of thermal motion of oxide molecules in the glass and the characteristic temperature point, n represents the molar percentage content of each oxide, a, b, and c are constants, and i is the characteristic temperature coefficient, 1.1<a<1.9, 1.5<b<2.7, 1.1<c<1.6, 5.29<i<9.73.

[0113] In an optional implementation manner of this embodiment, the value of δ / η can be 0.35, 0.37, 0.39, 0.41, 0.43, 0.45, 0.47, 0.49, 0.51, 0.53, 0.55, 0.57, 0.59, 0.61, 0.63, 0.65, 0.67, 0.69. In addition, the value range of δ / η can be 0.37~0.67, 0.39~0.65, 0.41~0.63, 0.43~0.61, 0.45~0.59, 0.47~0.57, 0.49~0.55, 0.51~0.53. Preferably, the value range of δ / η is 0.35~0.62.

[0114] It should be noted that i is the characteristic temperature coefficient, which corresponds to the temperature of the characteristic viscosity point of the heat treatment process involved in the embodiments of this application. In practical applications, characteristic glass temperatures such as the softening point, strain point, annealing point, and glass transition temperature can be obtained through testing using a high-temperature rotational viscometer, a plate viscometer, a strain point / annealing point tester, a linear dilatometer, or a differential scanning calorimeter (DSC). These temperatures are then tested, calculated, and fitted to obtain the corresponding temperature. The viscosity-temperature curve can then be fitted using the VFT equation to obtain the viscosity-temperature curve, which can then be used to determine the temperature of the characteristic viscosity point.

[0115] Through research, the applicant discovered that alkali metals and alkaline earth metals significantly increase the tendency of glass to crystallize, with Na2O and K2O being particularly prominent. This is because their small ionic radius makes them more easily attracted to high-field-strength ions under suitable temperature conditions. By introducing the δ calculation formula, the different oxides in the glass can be classified and calculated, and the different factors affecting the crystallization tendency can be comprehensively evaluated. This can describe the relationship between the electric field strength and ion migration of different oxides in the glass. Furthermore, by introducing the η calculation formula, the relationship between the kinetic energy of the thermal motion of the glass oxide molecules and the characteristic temperature point is linked to the aforementioned crystallization intensity, allowing a comprehensive assessment of the crystallization tendency at lower temperatures.

[0116] This embodiment characterizes the crystallization tendency of the glass by describing the ionic activity of the glass by δ / η. Setting the value of δ / η within a specific range can ensure that the viscosity of the glass is suitable for low-temperature crystallization. It is worth mentioning that the suitability for low-temperature crystallization mentioned in this embodiment means that the crystallization temperature required in the embodiment of this application is lower than the thermoforming and hot processing temperature, but high crystallinity can still be guaranteed. Since the crystallization temperature is relatively low, the generation of impurity phases can be effectively controlled.

[0117] In an optional implementation manner of this embodiment, the precursor glass also satisfies the following relationship:

[0118] ε=A*n SiO2 +B*n B2O3 +C*n Al2O3+D*n P2O5 +E*n RO +F*n R2O ,

[0119] 21.3≤ε≤25.6;

[0120] Among them, ε represents the degree of atomic stacking, n represents the molar percentage content of each oxide, A, B, C, D, E, and F are constants, A = 26.1 to 28.3, B = 18.3 to 27.3, C = 40.2 to 42.7, D ​​= 56.1 to 63.7, E = 12.2 to 22.6, and F = 10.9 to 36.2.

[0121] In an optional implementation manner of this embodiment, the value of ε can be 21.3, 21.5, 21.7, 21.9, 22.1, 22.3, 22.5, 22.7, 22.9, 23.1, 23.3, 23.5, 23.7, 23.9, 24.1, 24.3, 24.5, 24.7, 24.9, 25.1, 25.3, 25.5, 25.6. In an optional implementation manner, the value range can also be: 21.5-25.5, 21.7-25.3, 21.9-25.1, 22.1-24.9, 22.3-24.7, 22.5-24.5, 22.7-24.3, 22.9-24.1, 23.1-23.9, 23.3-23.7. Preferably, the value range of ε is 22-24.5.

[0122] In an optional implementation manner of this embodiment, the above atomic stacking degree calculation formula can be further expressed as:

[0123] ε=A*n SiO2 +B*n B2O3 +C*n Al2O3 +D*n P2O5 +12.5*n MgO +14.4*

[0124] n CaO +11.2*n Li2O +20.2*n Na2O +34*n K2O , 22.1≤ε≤24.5.

[0125] It should be noted that this embodiment regulates the content of glass components by using the atomic stacking degree calculation formula, which can improve the chemical stability and impact resistance of the glass phase in the microcrystalline glass.

[0126] It is worth mentioning that the formula / relationship described above in this embodiment is essentially a quantification of the degree of change in the glass viscosity and crystallization tendency related to the composition. It can understand the bond force between the anions and cations in the glass, the coordination number, and the degree of connectivity of the glass structure network, and then grasp the relationship between viscosity and glass composition. It can guide the crystallization temperature range of the glass and provide guidance for determining whether the glass formula is suitable for low-temperature crystallization.

[0127] The components of the precursor glass of this embodiment include, by mole percentage, the following: SiO2 greater than or equal to 63% and less than or equal to 72%; Al2O3 greater than or equal to 1.5% and less than or equal to 6%; Li2O greater than or equal to 16% and less than or equal to 26.8%; Na2O greater than or equal to 0% and less than or equal to 6.5%; K2O greater than or equal to 0 and less than or equal to 4%; P2O5 greater than or equal to 0.3% and less than or equal to 2.5%; ZrO2 greater than or equal to 0 and less than or equal to 5%; RO greater than or equal to 0 and less than or equal to 5.3%, and RO includes at least one of CaO, MgO, ZnO, and BaO; and a fining agent greater than or equal to 0 and less than or equal to 1%.

[0128] SiO2 is the basic component of the glass composition provided in this application. It is a network structure former of glass and glass-ceramics, and can form lithium silicate and lithium disilicate after crystallization. It should be noted that if the SiO2 content is low, then the crystals formed in the glass-ceramics will become fewer and the crystals will tend to become coarser, affecting the haze, drop ball test height and other properties of the glass-ceramics and glass-ceramics products. Therefore, the lower limit of the SiO2 content is set at 63%; in addition, if the SiO2 content is higher than a certain level, the glass melting temperature will be high, the material will be difficult to form, and it will not be easy to shape, affecting the consistency of the glass. Therefore, the upper limit of the SiO2 content is set at 72%. In some embodiments, the glass composition may contain approximately 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, or 72% SiO2. In some embodiments, the glass composition may further include SiO2 in an amount such as 64% or more and less than 71%, 65% or more and less than 70%, 66% or more and less than 69%, or 67% or more and less than 68%.

[0129] Al2O3 can be a component that forms the glass network structure or a cationic network member that acts as a charge balancer. In this application, Al2O3 is fully incorporated into the glass network structure, increasing the depth of the ion exchange layer and the surface compressive stress of the glass-ceramic product, enhancing the chemical stability of the glass, and improving its mechanical properties. On the one hand, if its content falls below a certain level, it will result in poor results. Therefore, the lower limit of the Al2O3 content by mass is 1.5%. On the other hand, if the Al2O3 content exceeds a certain level, the glass's meltability and resistance to devitrification will be reduced, and the crystals will tend to grow larger during crystallization, reducing the strength of the glass-ceramic and glass-ceramic products. Therefore, the upper limit of the Al2O3 content is 6%. In some embodiments, the glass composition may contain approximately 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, or 6% Al2O3. In some embodiments, the glass composition may further include Al2O3 in an amount such as greater than or equal to 2% and less than or equal to 5.5%, greater than or equal to 2.5% and less than or equal to 5%, greater than or equal to 3% and less than or equal to 4.5%, or greater than or equal to 3.5% and less than or equal to 4.5%.

[0130] Li2O is an essential component that forms a crystalline phase upon crystallization, contributing to the formation of lithium-containing crystalline phases such as lithium disilicate, petalite, and lithium silicate. It is also essential for chemical strengthening. However, if its content falls below a certain level, the effect is poor. Therefore, the lower limit of the Li2O content is 16%. Furthermore, if its content exceeds a certain level, the chemical stability of the glass is negatively impacted. Therefore, the upper limit of the Li2O content is preferably 26.8%. In some embodiments, the glass composition may include approximately 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, 19.5%, 20%, 20.5%, 21%, 21.5%, 22%, 22.5%, 23%, 23.5%, 24%, 24.5%, 25%, 25.5%, 26%, 26.5%, or 26.8% Li2O. In some embodiments, the glass composition may further include Li2O in an amount such as greater than or equal to 16.5% and less than or equal to 26.5%, greater than or equal to 17% and less than or equal to 26%, greater than or equal to 17.5% and less than or equal to 25.5%, greater than or equal to 18% and less than or equal to 25%, greater than or equal to 18.5% and less than or equal to 24.5%, greater than or equal to 19% and less than or equal to 24%, greater than or equal to 19.5% and less than or equal to 23.5%, greater than or equal to 20% and less than or equal to 23%, greater than or equal to 20.5% and less than or equal to 22.5%, or greater than or equal to 21% and less than or equal to 22%.

[0131] P2O5 helps improve the low-temperature melting properties of glass, enables phase separation and formation of crystal nuclei in the glass, and improves the thermal expansion stability of the glass during the crystallization process. The lower limit of the P2O5 content can be 0.3%. However, excessive P2O5 can easily reduce the glass's resistance to devitrification and cause phase separation, and the mechanical properties of the glass tend to deteriorate. Therefore, the upper limit of the P2O5 content is 2.5%. In some embodiments, the glass composition may include approximately 0.3%, 0.5%, 1%, 1.5%, 2%, or 2.5% P2O5. In some embodiments, the glass composition may also include P2O5 in amounts such as greater than or equal to 0.5% and less than or equal to 2%, or greater than or equal to 1% and less than or equal to 1.5%.

[0132] ZrO2 acts as a nucleating agent and helps improve the chemical stability of the glass. In this embodiment, the lower limit of the ZrO2 content can be 0. However, if too much ZrO2 is contained, the glass's resistance to devitrification can be easily reduced, and the control of the glass crystallization process becomes more difficult, requiring an increase in the crystallization temperature. Therefore, the upper limit of the ZrO2 content is 5%. In some embodiments, the glass composition may include approximately 0, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5% ZrO2. In some embodiments, the glass composition may also include ZrO2 in amounts such as: greater than or equal to 0.5% and less than or equal to 4.5%, greater than or equal to 1% and less than or equal to 4%, greater than or equal to 1.5% and less than or equal to 3.5%, or greater than or equal to 2% and less than or equal to 3%.

[0133] Na2O helps lower the glass transition temperature and crystallization temperature and inhibits the precipitation of unintended impurities. Its lower limit can be 0. However, if the Na2O content is too high, it increases the thermal expansion coefficient of the glass and reduces its thermal stability. Therefore, its upper limit is set at 6.5%. In some embodiments, the glass composition may include approximately 0, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, or 6.5% Na2O. In some embodiments, the glass composition may also include Na2O in amounts such as greater than or equal to 0.5% and less than or equal to 6%, greater than or equal to 1% and less than or equal to 5.5%, greater than or equal to 1.5% and less than or equal to 5%, greater than or equal to 2% and less than or equal to 4.5%, greater than or equal to 2.5% and less than or equal to 4%, or greater than or equal to 3% and less than or equal to 3.5%.

[0134] This embodiment optionally introduces 0-4% molar percentage of K2O into the glass composition, for example, 0, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, and 4% K2O. In some embodiments, the glass composition may further include K2O in amounts such as: greater than or equal to 0.5% and less than or equal to 4%, greater than or equal to 1% and less than or equal to 3.5%, greater than or equal to 1.5% and less than or equal to 3%, and greater than or equal to 2% and less than or equal to 2.5%. It is worth noting that the presence of multiple alkali metal oxides in the glass composition can exert a mixed alkali effect during the chemical strengthening of the glass-ceramics, restricting the migration of alkali metal ions during ion diffusion and helping to improve the chemical stability of the glass. Furthermore, the interaction of multiple alkali metal oxides can enhance the low-temperature melting and formability of the glass, and has a certain effect on lowering the softening point and molding temperature of the glass, thereby reducing the difficulty of chemical strengthening the glass-ceramics.

[0135] RO is an alkaline earth metal oxide, including at least one of CaO, MgO, ZnO, and BaO. The lower limit of the alkaline earth metal oxide content is 0 and the upper limit is 5.3%. In some embodiments, the glass composition may include approximately 0, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or 5.3% of the alkaline earth metal oxide. In some embodiments, the glass composition may also include alkaline earth metal oxide in an amount such as greater than or equal to 0.5% and less than or equal to 5%, greater than or equal to 1% and less than or equal to 4.5%, greater than or equal to 1.5% and less than or equal to 4%, greater than or equal to 2% and less than or equal to 3.5%, or greater than or equal to 2.5% and less than or equal to 3%.

[0136] In an optional embodiment of this embodiment, the glass composition includes: CaO (0% to 4%), MgO (0% to 4%), ZnO (0% to 4%), and BaO (0% to 4%). CaO helps reduce the high-temperature viscosity of the glass and increases its density; MgO helps reduce the viscosity of the glass, inhibits crystallization during glass forming, and improves its low-temperature melting properties; ZnO improves the melting properties of the glass, enhances its chemical stability, and refines the grain size during crystallization; and BaO improves the glass's glass-forming properties.

[0137] The glass composition of this embodiment may further include a fining agent, comprising one or more of SnO2, Sb2O3, and CeO2. The lower limit of the fining agent content is 0% and the upper limit is 1%. In some embodiments, the glass composition may include approximately 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1% of the fining agent. In some embodiments, the glass composition may further include a fining agent in an amount such as greater than or equal to 0.1% and less than or equal to 0.9%, greater than or equal to 0.2% and less than or equal to 0.8%, greater than or equal to 0.3% and less than or equal to 0.7%, or greater than or equal to 0.4% and less than or equal to 0.6%.

[0138] In an optional implementation manner of this embodiment, the components of the precursor glass, expressed in molar percentage, further include: B2O3 greater than or equal to 0 and less than or equal to 4.8%; and / or, TiO2 greater than or equal to 0% and less than or equal to 4%; and / or, Y2O3 greater than or equal to 0 and less than or equal to 4%; and / or, La2O3 greater than or equal to 0 and less than or equal to 0.5%.

[0139] B2O3 can lower the melting temperature of glass and remain in the glass phase after crystallization, ensuring the structural stability of the glass phase and improving the chemical stability of microcrystalline glass. However, too much B2O3 will increase volatilization during the glass melting process and increase the difficulty of glass homogenization. Based on this, the upper limit of the B2O3 content is set at 4.8%. In some embodiments, the glass composition may contain approximately 0, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, and 4.8% B2O3. In some embodiments, the glass composition may also contain B2O3 in amounts such as: greater than or equal to 0.5% and less than or equal to 4.8%, greater than or equal to 1% and less than or equal to 4.5%, greater than or equal to 1.5% and less than or equal to 4%, greater than or equal to 2% and less than or equal to 3.5%, and greater than or equal to 2.5% and less than or equal to 3%.

[0140] TiO2 helps lower the melting temperature of glass and improve its chemical stability. By introducing less than 4% by mass of TiO2, the glass crystallization process can be easily controlled. This embodiment optionally includes approximately 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, or 4% TiO2. In some embodiments, the glass composition may further include TiO2 in amounts such as greater than or equal to 0.5% and less than or equal to 3.5%, greater than or equal to 1% and less than or equal to 3%, or greater than or equal to 1.5% and less than or equal to 2.5%.

[0141] La2O3 and Y2O3 have high field strength and accumulation effect, which can strongly attract surrounding non-bridging oxygen (NBO, i.e., broken Si-O bonds), making the glass structure denser. At the same time, they can form La-O and YO bonds with stronger bond strength, thereby improving the chemical stability of the glass. La2O3 and Y2O3 are both commonly used oxides in optical glass, which can reduce dispersion and improve the optical properties of the glass. This embodiment optionally contains approximately 0, 0.1%, 0.15%, 0.25%, 0.3%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, and 4% La2O3 and / or Y2O3. In some embodiments, the glass composition may also contain La2O3 and / or Y2O3 in amounts such as greater than or equal to 0% and less than or equal to 4%, greater than or equal to 0.1% and less than or equal to 3%, and greater than or equal to 0.15% and less than or equal to 0.3%.

[0142] Nb2O5 and Ta2O5 have high field strength and also have the function of improving chemical stability, reducing glass dispersion and improving optical properties. Among them, Ta2O5 has lower dispersion, higher Abbe number, and extremely strong corrosion resistance, which can significantly improve chemical stability. Nb2O5 also has the function of promoting melting and increasing glass hardness and scratch resistance. This embodiment optionally contains approximately 0, 0.1%, 0.15%, 0.25%, 0.3%, 0.5%, and 1% of Nb2O5 and / or Ta2O5. In some embodiments, the glass composition may also contain Nb2O5 and / or Ta2O5 in the following content ranges: greater than or equal to 0% and less than or equal to 1%, greater than or equal to 0.15% and less than or equal to 0.5%, and greater than or equal to 0.2% and less than or equal to 0.3%.

[0143] In addition to having a high field strength that can improve chemical stability, HfO2 also has strong absorption of ultraviolet wavelengths, which can improve radiation protection and has a significant effect on protecting human eye health. This embodiment optionally contains approximately 0, 0.1%, 0.15%, 0.25%, 0.3%, 0.5%, and 1% HfO2. In some embodiments, the glass composition may also contain HfO2 in the following content ranges: greater than or equal to 0% and less than or equal to 1%, greater than or equal to 0.15% and less than or equal to 0.5%, and greater than or equal to 0.2% and less than or equal to 0.3%.

[0144] Bi2O3 has the properties of extremely high refractive index and low dispersion, and has a relatively low melting point, which can reduce the crystallization temperature of the glass. This embodiment optionally contains approximately 0, 0.1%, 0.15%, 0.25%, 0.3%, 0.5%, and 1% Bi2O3. In some embodiments, the glass composition may also contain Bi2O3 in the following content ranges: greater than or equal to 0% and less than or equal to 1%, greater than or equal to 0.15% and less than or equal to 0.5%, and greater than or equal to 0.2% and less than or equal to 0.3%.

[0145] In an optional implementation manner of this embodiment, the components of the precursor glass are expressed in mole percentages and satisfy at least one of the following relationships:

[0146] 5≤n Li2O / (n Na2O +n K2O )≤15;

[0147] 7≤n Li2O / (n CaO +n MgO +n ZnO )≤18;

[0148] 0.25≤n Li2O / (n SiO2 +n Al2O3 )≤0.5.

[0149] Li2O, Na2O, and K2O are all alkali metal oxides. By adding alkali metal oxides in combination, a mixed alkali effect can be formed, which can improve the crosslinking density of the glass network, chemical stability and other properties, and significantly improve the stability of micro-glass products. Li2O / (Na2O+K2O) needs to meet a certain value range. If the ratio of (Na2O+K2O) is too low, the mixed alkali effect cannot be formed. If the ratio of (Na2O+K2O) is too high, it will affect the formation ratio and formation speed of lithium crystals in the glass; (CaO+MgO+ZnO) has a higher field strength, It can enhance the mechanical properties of glass, such as elastic modulus and Vickers hardness. If the ratio of (CaO+MgO+ZnO) is too low, the beneficial effect of enhancing the mechanical properties cannot be achieved. If it is too high, it will promote the malignant growth of crystals and make it difficult to form microcrystals. (SiO2+Al2O3) is the main network former in glass, which plays a decisive role in the viscosity of glass and the network crosslinking density. If the ratio of (SiO2+Al2O3) is too low, controllable crystallization cannot be formed under suitable viscosity and temperature conditions. If the ratio is too high, it will affect the crystallinity and crystal size of the glass, and at the same time make the glass viscosity too high, which is not conducive to production.

[0150] Next, the embodiment of the present application also provides a micro-ceramic glass, which is obtained by heat treatment (i.e., nucleation and crystallization treatment) based on the aforementioned precursor glass, and the lower limit crystallization temperature of the micro-ceramic glass is 553-639°C and the upper limit crystallization temperature is 989-1123°C. The micro-ceramic glass meets at least one of the following performance indicators: Vickers hardness greater than or equal to 727kgf / mm 2 , fracture toughness greater than or equal to 1.01Mpa·m 1 / 2 , Young's modulus greater than or equal to 99GPa, shear modulus greater than or equal to 40GPa, |B| value less than or equal to 0.74% when the thickness is 0.55mm, haze less than or equal to 0.14%, and transmittance relative to visible light with a wavelength of 550nm greater than or equal to 91%.

[0151] The embodiments of the present application exemplarily provide a first microcrystalline glass, whose components, expressed in molar percentage, include: SiO2 greater than or equal to 60% and less than or equal to 78%; Al2O3 greater than or equal to 2% and less than or equal to 6.7%; Li2O greater than or equal to 16% and less than or equal to 24%; P2O5 greater than or equal to 0 and less than or equal to 2.2%; ZrO2 greater than or equal to 0 and less than or equal to 5%; RO greater than or equal to 0 and less than or equal to 5.3%, and RO includes at least one of CaO, MgO, ZnO, and BaO; Na2O greater than or equal to 0% and less than or equal to 5%; K2O greater than or equal to 0 and less than or equal to 4%; and a clarifier greater than or equal to 0 and less than or equal to 1%.

[0152] Among them, the preferred content of SiO2 is 66-71.28%, more preferably 66.5-70.8%, and further preferably 67.1-69.5%; the preferred content of Al2O3 is 3-5.5%, more preferably 3.5-5.2%, and further preferably 3.5-4.6%; the preferred content of P2O5 is 0.3-1.6%, more preferably 0.6-1.2%, and further preferably 0.8-1.1%; the preferred content of ZrO2 is 0-3. 7%, more preferably 0-2.6%, further preferably 0.6-2.6%; the preferred content of Na2O is 0-3.5%, more preferably 0-2.0%, further preferably 0-1.5%; the preferred content of K2O is 0-2%, more preferably 0-0.5%, further preferably 0-0.3%; the preferred content of Li2O is 18-23.5%, more preferably 20.5-23.5%, further preferably 21.5-23.5%. The alkaline earth metal oxides mentioned above are respectively comprised in the glass-ceramics of: greater than or equal to 0 and less than or equal to 4% CaO, greater than or equal to 0 and less than or equal to 4% MgO, greater than or equal to 0 and less than or equal to 4% ZnO, and greater than or equal to 0 and less than or equal to 4% BaO. The preferred content of CaO is 0-2.5%, more preferably 0-1.5%, and even more preferably 0.2-0.5%. The preferred content of MgO is 0-2.5%, more preferably 0-1%, and even more preferably 0-0.5%. The preferred clarifier is SnO2, with a preferred content of 0.05-0.5%, more preferably 0.05-0.2%, and even more preferably 0.05-0.15%. In addition, the microcrystalline glass may also include: B2O3 greater than or equal to 0 and less than or equal to 4.8%, and / or TiO2 greater than or equal to 0% and less than or equal to 4%, and / or Y2O3 greater than or equal to 0 and less than or equal to 4%, and / or La2O3 greater than or equal to 0 and less than or equal to 0.5%, wherein the preferred content of B2O3 is 0-3%, more preferably 0-1.6%, and further preferably 0-0.4%; the preferred content of TiO2 is 0-2.6%, more preferably 0-1.2%, and further preferably 0-0.6%; the preferred content of Y2O3 is 0-2%, more preferably 0-0.5%, and further preferably 0-0.3%; the preferred content of La2O3 is 0-2%, more preferably 0-0.5%, and further preferably 0-0.3%.

[0153] The crystal phases of the microcrystalline glass are lithium disilicate and petalite, the average grain size of the lithium silicate crystal phase is less than or equal to 32.5-39.3 nm, the average grain size of the petalite crystal phase is less than or equal to 24.6-29.1 nm, and the crystallinity is greater than or equal to 84.72%. Furthermore, the lithium disilicate crystalline phase meets the following indicators: the size of 98% of the grains in the lithium disilicate crystalline phase as a whole is less than or equal to 55 nm, the size of 95% of the grains in the lithium disilicate crystalline phase as a whole is less than or equal to 50 nm, and the size of 80% of the grains in the lithium disilicate crystalline phase as a whole is less than or equal to 45 nm; the petalite crystalline phase meets the following indicators: the size of 98% of the grains in the petalite crystalline phase as a whole is less than or equal to 45 nm, the size of 95% of the grains in the petalite crystalline phase as a whole is less than or equal to 40 nm, and the size of 80% of the grains in the petalite crystalline phase as a whole is less than or equal to 30 nm; the crystallinity is greater than or equal to 85.8%.

[0154] The embodiment of the present application exemplarily provides a second type of microcrystalline glass, whose components, expressed in molar percentage, include: SiO2 greater than or equal to 60% and less than or equal to 78%; Al2O3 greater than or equal to 1.5% and less than or equal to 5.5%; Li2O greater than or equal to 18% and less than or equal to 26.8%; P2O5 greater than or equal to 0.1 and less than or equal to 2.5%; ZrO2 greater than or equal to 0 and less than or equal to 5%; RO greater than or equal to 0 and less than or equal to 3.4%, and RO includes at least one of CaO, MgO, ZnO, and BaO; Na2O greater than or equal to 0% and less than or equal to 6.5%; K2O greater than or equal to 0 and less than or equal to 4%; and a clarifier greater than or equal to 0 and less than or equal to 1%.

[0155] Among them, the preferred content of SiO2 is 61.7-75.4%, more preferably 62.4-71.3%, and further preferably 64.7-68.3%; the preferred content of Al2O3 is 2-5.5%, more preferably 2-4.2%, and further preferably 2.5-3.5%; the preferred content of P2O5 is 0.6-2.5%, more preferably 0.6-1.5%, and further preferably 1.0-1.4%; the preferred content of ZrO2 is 0-3.7% , the more preferred content is 0-2.6%, and the further preferred content is 0.6-2.6%; the preferred content of Na2O is 0-4.8%, the more preferred content is 0-3.1%, and the further preferred content is 1.0-3.1%; the preferred content of K2O is 0-2%, the more preferred content is 0-1.2%, and the further preferred content is 0-0.6%; the preferred content of Li2O is 18-25.8%, the more preferred content is 22.2-25.8%, and the further preferred content is 23.4-24.4%. The alkaline earth metal oxides mentioned above are respectively comprised in the glass-ceramics of: greater than or equal to 0 and less than or equal to 4% CaO, greater than or equal to 0 and less than or equal to 4% MgO, greater than or equal to 0 and less than or equal to 4% ZnO, and greater than or equal to 0 and less than or equal to 4% BaO. The preferred content of CaO is 0-2.5%, more preferably 0-1.5%, and even more preferably 0-0.5%. The preferred content of MgO is 0-2.5%, more preferably 0-1.5%, and even more preferably 0-0.5%. The preferred clarifier is SnO2, with a preferred content of 0.05-0.5%, more preferably 0.05-0.2%, and even more preferably 0.05-0.15%. In addition, the microcrystalline glass may also include: B2O3 greater than or equal to 0 and less than or equal to 4.8%, and / or TiO2 greater than or equal to 0% and less than or equal to 4%, and / or Y2O3 greater than or equal to 0 and less than or equal to 4%, and / or La2O3 greater than or equal to 0 and less than or equal to 0.5%, wherein the preferred content of B2O3 is 0-3%, more preferably 0-1.6%, and further preferably 0-0.4%; the preferred content of TiO2 is 0-2.6%, more preferably 0-1.2%, and further preferably 0-0.6%; the preferred content of Y2O3 is 0-2%, more preferably 0-0.5%, and further preferably 0-0.3%; the preferred content of La2O3 is 0-2%, more preferably 0-0.5%, and further preferably 0-0.3%.

[0156] The crystalline phase of this glass-ceramic is lithium disilicate, which meets the following criteria: an average grain size of less than or equal to 38 to 45.7 nm, and a crystallinity greater than or equal to 56.38%. Furthermore, the lithium disilicate crystalline phase meets the following criteria: 98% of the grains in the overall crystalline phase have a size of less than or equal to 60 nm, 95% of the grains in the overall crystalline phase have a size of less than or equal to 55 nm, and 80% of the grains in the overall crystalline phase have a size of less than or equal to 50 nm; and the crystallinity is greater than or equal to 61.22%.

[0157] Next, an embodiment of the present application further provides a chemically strengthened glass-ceramics, which is obtained by sequentially subjecting the precursor glass provided in the aforementioned embodiment to heat treatment and ion exchange treatment.

[0158] It is worth mentioning that the chemically strengthened microcrystalline glass of this embodiment meets at least one of the following performance indicators: Vickers hardness greater than or equal to 655kgf / mm2, fracture toughness greater than or equal to 1.2Mpa·m1 / 2, Young's modulus greater than or equal to 98.38GPa, shear modulus greater than or equal to 39.35GPa, |B| value less than or equal to 0.74% when the thickness is 0.55mm, haze less than or equal to 0.13%, transmittance relative to visible light with a wavelength of 550nm greater than or equal to 91%, nine-point drop test height based on 32g steel ball when the thickness is 0.55mm is 980~1290mm, maximum bending strength is 1052~1200MPa, the whole machine drop test height based on 80 mesh sandpaper is 850~1020mm, and the whole machine drop test height based on 180 mesh sandpaper is 1200~1600mm.

[0159] Accordingly, an embodiment of the present application further provides a glass preparation method, which specifically includes:

[0160] Step A: Mix the raw materials uniformly according to the glass formula, melt them at a preset melting temperature and melting time, and then form and anneal them to obtain a precursor glass;

[0161] Step B: heat-treating the precursor glass to obtain glass-ceramics.

[0162] Among them, the precursor glass satisfies the following relationship:

[0163] δ=a*n RO +b*(n Na2O +n K2O )+c*n Li2O ,

[0164] η=12.5 / (0.57+4.58*i^0.55929)

[0165] 0.35≤δ / η≤0.69;

[0166] Among them, δ represents the ionic activity of each ion in the glass, η represents the correlation index between the kinetic energy of thermal motion of oxide molecules in the glass and the characteristic temperature point, n represents the molar percentage content of each oxide, a, b, and c are constants, and i is the characteristic temperature coefficient, 1.1<a<1.9, 1.5<b<2.7, 1.1<c<1.6, 5.29<i<9.73.

[0167] In actual applications, glass raw materials are first prepared according to the glass components and contents provided in the aforementioned embodiments, and the glass raw materials are evenly mixed and melted at 1350-1550°C. The precursor glass is then obtained after clarification, homogenization, forming, and annealing. Then, the precursor glass is crystallized using a two-stage heat treatment method. The first step of the heat treatment is a nucleation treatment, and the second step of the heat treatment is a crystallization treatment. The glass is then cooled to room temperature to obtain microcrystalline glass that meets the expected crystallinity, grain size, and crystal phase ratio.

[0168] Among them, corresponding to the first type of microcrystalline glass provided in the aforementioned embodiment, its heat treatment process may include: placing the glass raw material in a crystallization furnace, heating it to 500-610°C at a heating rate greater than or equal to 6°C / min, and then keeping it warm for 200-300 minutes, then heating it to 655-800°C at a heating rate greater than or equal to 6°C / min, and then keeping it warm for 60-120 minutes, and finally cooling it at a cooling rate less than or equal to 2°C / min.

[0169] Corresponding to the second type of microcrystalline glass provided in the aforementioned embodiment, its heat treatment process may include: placing the glass raw material in a crystallization furnace, heating it to 560-590°C at a heating rate of 8-12°C / min and then keeping it warm for 220-250 minutes, then heating it to 750-790°C at a heating rate of 8-12°C / min and then keeping it warm for 70-90 minutes, and finally cooling it at a cooling rate less than or equal to 2°C / min.

[0170] Therefore, by heat-treating glass raw materials of different components using different heat treatment processes, desired types of crystal phases, desired crystal ratios, grain size distributions, etc. can be obtained.

[0171] It is worth mentioning that the microcrystalline glass obtained in the above step B can be further cold-processed, that is, through shaping, multi-wire cutting, CNC, grinding, rough grinding, fine polishing, cleaning and other processes, to obtain microcrystalline glass with a thickness of 0.35 to 0.7 mm.

[0172] In addition, corresponding to the second type of microcrystalline glass provided in the aforementioned embodiment, this embodiment can also perform hot bending treatment on the microcrystalline glass, wherein the pressure of the hot bending workstation is 0.7~1.1MPa, and the operating time of a single workstation is 70~110s.

[0173] In an optional implementation manner of this embodiment, the hot bending treatment needs to go through four preheating workstations, three hot pressing workstations and two cooling workstations; among them, the operating temperature of the first preheating workstation is 430~470℃, the operating temperature of the second preheating workstation is 530~570℃, the operating temperature of the third preheating workstation is 630~670℃, the operating temperature of the fourth preheating workstation is 710~730℃, the operating temperature of the first hot pressing workstation is 740~760℃, the operating temperature of the second hot pressing workstation is 740~760℃, the operating temperature of the third hot pressing workstation is 580~620℃, the operating temperature of the first cooling workstation is 430~470℃, and the operating temperature of the second cooling workstation is 280~320℃.

[0174] In an optional implementation manner of this embodiment, the above-mentioned glass preparation method further includes: step C, immersing the microcrystalline glass in a chemical strengthening salt bath for ion exchange treatment to obtain chemically strengthened microcrystalline glass.

[0175] In this embodiment, when chemically strengthening the microcrystalline glass, the chemical strengthening salt bath includes, by mass percentage: KNO3 greater than or equal to 9.99% and less than or equal to 39.99%, NaNO3 greater than or equal to 59.99 and less than or equal to 89.99%, and LiNO3 greater than or equal to 0.03% and less than or equal to 0.1%. The temperature of the chemical strengthening salt bath is 460-490°C, and the duration of the ion exchange treatment is 4-10 hours.

[0176] Chemical strengthening involves placing glass-ceramics in a salt bath for ion exchange, which results in the formation of compressive and tensile stress layers. The salt bath in this embodiment is a mixed salt bath. Compared to traditional multiple strengthening processes, this embodiment achieves multiple ion exchange events between the salt bath and the glass-ceramics in a single strengthening step, improving chemical strengthening efficiency and reducing salt bath usage. The resulting chemically strengthened glass-ceramics exhibit a deeper compressive stress layer and higher surface compressive stress.

[0177] It's worth noting that after chemically strengthening the glass-ceramics, surface residue can be cleaned after removal from the salt bath, followed by re-grinding using a flat grinder. The re-grinding parameters are as follows: white abrasive, 75 hardness, 10 rpm for both upper and lower grinding discs, 1.13 g / cm³ grinding concentration, 150-250 kg pressure, and 100-300 re-grinding cycles. Finally, the chemically strengthened glass-ceramics can be cleaned using a neutral detergent with a pH of 7-9 to obtain chemically strengthened glass-ceramics products.

[0178] Corresponding to the first type of microcrystalline glass provided in the aforementioned embodiment, the chemically strengthened microcrystalline glass obtained after ion exchange treatment meets the following performance indicators: the surface compressive stress value is 255~280MPa, the compressive stress value at a depth of 50μm from the surface is 105~112MPa, the compressive stress value at a depth of 80μm from the surface is 65~70MPa, the depth of the compressive stress layer is 121~135μm, the absolute value of the maximum tensile stress is 100~110MPa, and the absolute value of the average tensile stress is 59~63Mpa.

[0179] Corresponding to the second type of microcrystalline glass provided in the aforementioned embodiment, the chemically strengthened microcrystalline glass obtained after ion exchange treatment meets the following performance indicators: the surface compressive stress value is 240~276MPa, the compressive stress value at a depth of 50μm from the surface is 102~125MPa, the compressive stress value at a depth of 80μm from the surface is 65~75MPa, the depth of the compressive stress layer is 113~130μm, the absolute value of the maximum tensile stress is 105~108MPa, and the absolute value of the average tensile stress is 58~63MPa.

[0180] Next, in order to illustrate the technical effects of the precursor glass, microcrystalline glass and chemically strengthened microcrystalline glass suitable for low-temperature crystallization of this embodiment, the present application conducted tests on glass products with different component contents to determine their characteristics. The embodiment in Table 1 shows the relevant test conditions and test data of the glass products with different component contents of this application.

[0181] Table 1

[0182]

[0183]

[0184]

[0185]

[0186] Table 2

[0187]

[0188]

[0189]

[0190]

[0191] On the one hand, it can be seen from Table 1 and Table 2 that the nucleation temperature and crystallization temperature of the glass-ceramics of the embodiments of the present application are in a relatively low range, that is, the heat treatment process applied to the precursor glass is relatively mild. The present application controls the viscosity of the glass to ensure that the glass-ceramics can achieve a sufficient degree of crystallization at a low temperature. On the other hand, referring to the mechanical property data (i.e., Vickers hardness, fracture toughness, Young's modulus, shear modulus, Poisson's ratio) and optical property data (i.e., refractive index, |B| value, haze, transmittance) provided in the embodiments in Tables 1 and 2 above, it can be seen that even if a relatively mild heat treatment process is used in the preparation of the glass-ceramics in order to control the impurity phase, the glass-ceramics finally obtained can still have a high degree of crystallinity and can maintain relatively excellent mechanical and optical properties. That is, the present application creatively optimizes the glass component ratio based on the activity level of ions in the glass, the correlation between the thermal kinetic energy of oxide molecules in the glass and the characteristic temperature, and the degree of atomic stacking, so that the viscosity of the glass is controlled and a strong crystallization tendency is exhibited at low temperatures, effectively overcoming the current problem faced in the production process of microcrystalline glass of the inability to balance the control of impurity phases with mechanical and optical properties.

[0192] like Figure 1 The DSC test curve of the glass-ceramics of Example 4 is shown. In the DSC test spectrum of the corresponding prepared glass-ceramics, the temperature of the first endothermic peak is 511.4°C, and the temperature of the first exothermic peak is 620°C. Figure 2 The figure shows the XRD test curve of the glass-ceramics corresponding to Example 4. It can be seen from the figure that the glass-ceramics provided by the present application has a lithium disilicate crystal phase. Figure 3 The figure shows a scanning electron microscope image of the glass-ceramics corresponding to Example 4. It can be seen from the figure that the grain size of the lithium disilicate crystal phase provided by the present application is less than 60nm; Figure 4 Shown is a viscosity-temperature characteristic diagram of the microcrystalline glass corresponding to Example 4, which is used to characterize the viscosity-temperature characteristics of the product.

[0193] It is also worth mentioning that due to the above-mentioned performance advantages of the chemically strengthened microcrystalline glass provided in the embodiments of the present application, it can be widely used in the production of protective covers of electronic devices, optical elements, photovoltaic devices or windows of household appliances.

[0194] Finally, it should be noted that in the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0195] The above is a description of the precursor glass, microcrystalline glass, chemically strengthened microcrystalline glass and glass preparation method provided in this application. For those skilled in the art, based on the ideas of the embodiments of this application, equivalent replacements made in the specific implementation methods and application scopes should all be covered by the scope of the claims of this application. In summary, the content of this specification should not be understood as a limitation on the scheme of this application.

Claims

1. A precursor glass suitable for low temperature crystallization treatment, characterized in that: The precursor glass satisfies the following relationship: δ=a*n RO +b*(n Na2O +n K2O )+c*n Li2O , η=12.5 / (0.57+4.58*i^0.55929) 0.35≤δ / η≤0.69; Among them, δ represents the ionic activity of each ion in the glass, η represents the correlation index between the kinetic energy of thermal motion of oxide molecules in the glass and the characteristic temperature point, n represents the molar percentage content of each oxide, a, b, and c are constants, and i is the characteristic temperature coefficient, 1.1<a<1.9, 1.5<b<2.7, 1.1<c<1.6, 5.29<i<9.

73.

2. The precursor glass according to claim 1, characterized in that The precursor glass also satisfies the following relationship: ε=A*n SiO2 +B*n B2O3 +C*n Al2O3 +D*n P2O5 +E*n RO +F*n R2O , 21.3≤ε≤25.6; Among them, ε represents the degree of atomic stacking, n represents the molar percentage content of each oxide, A, B, C, D, E, and F are constants, A = 26.1 to 28.3, B = 18.3 to 27.3, C = 40.2 to 42.7, D ​​= 56.1 to 63.7, E = 12.2 to 22.6, and F = 10.9 to 36.

2.

3. The precursor glass according to claim 2, characterized in that The precursor glass also satisfies the following relationship: ε=A*n SiO2 +B*n B2O3 +C*n Al2O3 +D*n P2O5 +12.5*n MgO +14.4*n CaO +11.2*n Li2O +20.2*n Na2O +34*n K2O 4 22.1≤ε≤24.

5.

4. The precursor glass according to claim 1, characterized in that Its components, expressed in mole percentage, include: SiO2 greater than or equal to 63% and less than or equal to 72%; 1.5% or more and 6% or less of Al2O3; 16% or more and 26.8% or less of Li2O; greater than or equal to 0 and less than or equal to 6.5% Na2O; K2O greater than or equal to 0 and less than or equal to 4%; 0.3% or more and 2.5% or less of P2O5; ZrO2 greater than or equal to 0 and less than or equal to 5%; RO is greater than or equal to 0 and less than or equal to 5.3%, and RO includes at least one of CaO, MgO, ZnO, and BaO; Greater than or equal to 0 and less than or equal to 1% of clarifier.

5. The precursor glass according to claim 4, characterized in that Its components, in molar percentage, also include: greater than or equal to 0 and less than or equal to 4.8% B2O3; and / or, greater than or equal to 0% and less than or equal to 2.6% TiO2; and / or, greater than or equal to 0 and less than or equal to 0.5% La2O3.

6. The precursor glass according to claim 4, characterized in that The components thereof include, in mole percentage, greater than or equal to 1.5% and less than or equal to 5.5% of Al2O3.

7. The precursor glass according to claim 4, characterized in that: The components thereof include, by mole percentage, greater than or equal to 0.6% and less than or equal to 1.6% of P2O5.

8. The precursor glass according to claim 4, characterized in that The components thereof include, by mole percentage, greater than or equal to 16% and less than or equal to 26.8% of Li2O, greater than or equal to 0 and less than or equal to 4.5% of Na2O, and greater than or equal to 0 and less than or equal to 2% of K2O.

9. The precursor glass according to claim 8, characterized in that The components thereof include, by mole percentage, greater than or equal to 22.2% and less than or equal to 25.8% of Li2O, greater than or equal to 0 and less than or equal to 3.1% of Na2O, and greater than or equal to 0 and less than or equal to 1.2% of K2O.

10. The precursor glass according to claim 9, characterized in that: The components thereof include, by mole percentage, greater than or equal to 20.5% and less than or equal to 23.5% of Li2O, greater than or equal to 0 and less than or equal to 2% of Na2O, and greater than or equal to 0 and less than or equal to 0.5% of K2O.

11. The precursor glass also includes at least one of Y2O3, La2O3, Nb2O5, Ta2O5, HfO2, and Bi2O3.

12. The precursor glass according to claim 4, characterized in that: The components of the precursor glass are expressed in mole percentages and satisfy at least one of the following relationships: 4≤n Li2O / (n Na2O +n K2O )≤17; 6≤n Li2O / (n CaO +n MgO +n ZnO )≤18; 0.24≤n Li2O / (n SiO2 +n Al2O3 )≤0.38。 13. A glass-ceramic, characterized in that: The glass-ceramics is obtained by heat treating the precursor glass according to any one of claims 1 to 11.

14. The glass-ceramic according to claim 13, characterized in that: The lower limit temperature of crystallization is 600-650℃, and the upper limit temperature of crystallization is 989-1123℃.

15. The glass-ceramic according to claim 13, characterized in that: The crystal phase is lithium disilicate, and the lithium disilicate crystal phase meets the following indicators: an average grain size is less than or equal to 38 to 45.7 nm, and a crystallinity is greater than or equal to 56.38%.

16. The glass-ceramic according to claim 15, characterized in that: The lithium disilicate crystalline phase meets the following indicators: the size of 98% of the grains in the overall crystalline phase is less than or equal to 60nm, the size of 95% of the grains in the overall crystalline phase is less than or equal to 55nm, and the size of 80% of the grains in the overall crystalline phase is less than or equal to 50nm; the crystallinity is less than or equal to 68.22%.

17. The glass-ceramic according to any one of claims 13 to 16, characterized in that: Meet at least one of the following performance indicators: Vickers hardness greater than or equal to 727kgf / mm 2 , fracture toughness greater than or equal to 1.01Mpa·m 1 / 2 , Young's modulus greater than or equal to 99GPa, shear modulus greater than or equal to 40GPa, |B| value less than or equal to 0.75% when the thickness is 0.55mm, haze less than or equal to 0.14%, and transmittance relative to visible light with a wavelength of 550nm greater than or equal to 91%.

18. A chemically strengthened glass-ceramic, characterized in that: The chemically strengthened glass-ceramics is obtained by sequentially subjecting the precursor glass according to any one of claims 1 to 11 to heat treatment and ion exchange treatment.

19. The chemically strengthened glass-ceramics according to claim 16, wherein: Meet at least one of the following performance indicators: Vickers hardness greater than or equal to 655kgf / mm 2 , fracture toughness greater than or equal to 1.2Mpa·m 1 / 2 , Young's modulus greater than or equal to 98.38 GPa, shear modulus greater than or equal to 39.35 GPa, |B| value less than or equal to 0.8% when the thickness is 0.55 mm, haze less than or equal to 0.13%, transmittance relative to visible light with a wavelength of 550 nm is greater than or equal to 91%, the nine-point drop test height based on a 32g steel ball when the thickness is 0.55 mm is 980~1290 mm, the maximum bending strength is 1052~1200 MPa, the whole machine drop test height based on 80 mesh sandpaper is 850~1020 mm, and the whole machine drop test height based on 180 mesh sandpaper is 1200~1600 mm.

20. A method for preparing glass, characterized in that: include: The raw materials are mixed evenly according to the glass formula, melted at a preset melting temperature and melting time, and then formed and annealed to obtain a precursor glass; heat-treating the precursor glass to obtain glass-ceramics; Wherein, the precursor glass satisfies the following relationship: δ=a*n RO +b*(n Na2O +n K2O )+c*n Li2O , η=12.5 / (0.57+4.58*i^0.55929) 0.35≤δ / η≤0.69; Among them, δ represents the ionic activity of each ion in the glass, η represents the correlation index between the kinetic energy of thermal motion of oxide molecules in the glass and the characteristic temperature point, n represents the molar percentage content of each oxide, a, b, and c are constants, and i is the characteristic temperature coefficient, 1.1<a<1.9, 1.5<b<2.7, 1.1<c<1.6, 5.29<i<9.

73.

21. The glass preparation method according to claim 18, characterized in that: The heat treatment of the precursor glass comprises: The precursor glass is placed in a crystallization furnace, heated to 500-610°C at a heating rate greater than or equal to 6°C / min, and then kept warm for 200-300 minutes, then heated to 655-800°C at a heating rate greater than or equal to 6°C / min, and then kept warm for 60-120 minutes, and finally cooled at a cooling rate less than or equal to 2°C / min.

22. The glass preparation method according to claim 18, wherein: The crystallization heat treatment of the precursor glass comprises: The precursor glass is placed in a crystallization furnace, heated to 560-590°C at a heating rate of 8-12°C / min, and then kept warm for 220-250 minutes. Then, it is heated to 750-790°C at a heating rate of 8-12°C / min, and then kept warm for 70-90 minutes. Finally, it is cooled at a cooling rate of less than or equal to 2°C / min.

23. The glass preparation method according to claim 18, characterized in that: Also includes: The glass-ceramics is subjected to heat bending treatment through a heat bending workstation; wherein, the pressure of the heat bending workstation is 0.7-1.1 MPa, and the operation time of a single workstation is 70-110 seconds.

24. The glass preparation method according to claim 21, characterized in that: The hot bending process needs to go through four preheating workstations, three hot pressing workstations and two cooling workstations; Among them, the operating temperature of the first preheating workstation is 430~470℃, the operating temperature of the second preheating workstation is 530~570℃, the operating temperature of the third preheating workstation is 630~670℃, the operating temperature of the fourth preheating workstation is 710~730℃, the operating temperature of the first hot pressing workstation is 740~760℃, the operating temperature of the second hot pressing workstation is 740~760℃, the operating temperature of the third hot pressing workstation is 580~620℃, the operating temperature of the first cooling workstation is 430~470℃, and the operating temperature of the second cooling workstation is 280~320℃.

25. The glass preparation method according to claim 20, characterized in that: Also includes: immersing the glass-ceramics in a chemically strengthened salt bath for ion exchange treatment to obtain chemically strengthened glass-ceramics; The chemical strengthening salt bath comprises, by mass percentage, KNO3 greater than or equal to 9.99% and less than or equal to 39.99%, NaNO3 greater than or equal to 59.99 and less than or equal to 89.99%, and LiNO3 greater than or equal to 0.03% and less than or equal to 0.1%.

26. The glass preparation method according to claim 25, characterized in that: The temperature of the chemical strengthening salt bath is 460-490° C., and the duration of the ion exchange treatment is 4-10 hours.

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