Spinel microcrystalline glass, preparation method and application thereof

Abstract

This invention provides a transparent spinel microcrystalline glass with spinel as the main crystalline phase and excellent optical properties. Compared with existing spinel microcrystalline glasses, the spinel microcrystalline glass provided by this invention is easier to polish, has lower polishing difficulty, and higher polishing efficiency. By adjusting the glass formulation and utilizing the synergistic effect of specific amounts of various oxide components, this invention achieves the desired target crystalline phase while giving the microcrystalline glass a specific microstructure. This not only ensures the high intrinsic strength and excellent optical properties of the microcrystalline glass but also significantly reduces the polishing difficulty of the spinel microcrystalline glass while ensuring that its weather resistance meets the application requirements. This results in higher polishing efficiency and easier mass production.

Description

Technical Field

[0001] This invention relates to the field of glass-ceramic technology, and in particular to a spinel glass-ceramic, its preparation method, and its applications. Background Technology

[0002] Microcrystalline glass (also known as glass-ceramic) has become a better choice for screen covers due to its excellent mechanical properties and light transmittance. The mainstream transparent microcrystalline glass on the market is mainly lithium aluminum silicon system, and its main crystalline phases are one or more of quartz, lithium feldspar, lithium silicate, and lithium disilicate.

[0003] Spinel crystals belong to the isometric crystal system, are face-centered cubic, have a Mohs hardness of 8, and zinc-aluminum spinel has a Young's modulus of 290 GPa and a shear modulus of 146 GPa. Within spinel glass-ceramics, spinel crystals can hinder crack propagation, distort the crack propagation path, and increase the crack propagation fracture energy, thus enabling transparent spinel glass-ceramics to exhibit high mechanical strength and hardness.

[0004] Given the excellent mechanical properties of spinel glass-ceramics, their application prospects in the field of smartphone glass covers are broad. However, existing transparent spinel glass-ceramics generally suffer from high machining difficulty, with polishing being significantly more challenging than that of ordinary lithium aluminum silicon glass-ceramics. How to reduce the polishing difficulty of spinel glass-ceramics, improve polishing efficiency, and enhance their mass production capabilities has become a pressing issue for those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a spinel microcrystalline glass and its preparation method, so as to improve the polishing efficiency of spinel microcrystalline glass. The specific technical solution is as follows:

[0006] In a first aspect, a spinel microcrystalline glass is provided, wherein the spinel microcrystalline glass comprises a spinel as the main crystalline phase; expressed as a molar percentage of oxides, the composition of the spinel microcrystalline glass comprises: SiO2 35.00 mol%–48.00 mol%, Al2O3 22.00 mol%–30.00 mol%, ZrO2 3.00 mol%–4.00 mol%, MgO 4.00 mol%–7.00 mol%, ZnO 8.00 mol%–11.00 mol%, Na2O 2.00 mol%–12.00 mol%, K2O 0.00 mol%–0.50 mol%, Li2O 0.00 mol%–4.00 mol%, B2O3 3.00 mol%–10.00 mol%, Y2O3 0.00 mol%–1.00 mol%, BaO 0.00 mol% to 2.00 mol%.

[0007] In some embodiments of the present invention, the composition of the spinel microcrystalline glass, based on the molar percentage of oxides, satisfies: X = (5.23B₂O₃ + 1.52Na₂O + 1.33Li₂O) / (100% - ZrO₂ - 2MgO - 2ZnO), 0.460 ≤ X ≤ 1.000, preferably, 0.460 ≤ X ≤ 0.900.

[0008] In some embodiments of the present invention, the composition of the spinel microcrystalline glass, based on the molar percentage of oxides, satisfies: Y = Al2O3 / (MgO + ZnO), 1.000 ≤ Y ≤ 2.000, preferably, 1.600 ≤ Y ≤ 1.800; and / or, Z = (Na2O + K2O + Li2O + B2O3) / (SiO2 + Al2O3), 0.100 ≤ Z ≤ 0.500, preferably, 0.150 ≤ Z ≤ 0.300.

[0009] In some embodiments of the present invention, the spinel is (Zn,Mg)Al2O4, which is zinc-magnesium spinel, or zinc-magnesium spinel solid solution, which is a solid solution formed by zinc-aluminum spinel and magnesium-aluminum spinel; and / or, the spinel microcrystalline glass includes the secondary crystalline phase tetragonal ZrO2.

[0010] In some embodiments of the present invention, the average grain size of the spinel microcrystalline glass is 3.00 nm to 25.00 nm, preferably 3.00 nm to 8.00 nm.

[0011] In some embodiments of the present invention, the crystallinity of the spinel microcrystalline glass is 10.00wt% to 50.00wt%, preferably 30.00wt% to 50.00wt%.

[0012] In some embodiments of the present invention, the spinel microcrystalline glass does not contain TiO2.

[0013] In some embodiments of the present invention, the spinel microcrystalline glass is transparent in the visible light range.

[0014] In some embodiments of the present invention, at a thickness of 0.7 mm, the transmittance of the spinel microcrystalline glass for light at a wavelength of 550 nm is greater than or equal to 85.00%, preferably 85.00% to 95.00%, more preferably 88.00% to 95.00%; and / or, at a thickness of 0.7 mm, the optical b-value of the spinel microcrystalline glass is 0.20 to 1.50, preferably 0.20 to 1.20, more preferably 0.20 to 1.00.

[0015] In some embodiments of the present invention, the Young's modulus of the spinel microcrystalline glass is 100 GPa to 150 GPa, preferably 110 GPa to 150 GPa.

[0016] In some embodiments of the present invention, the spinel microcrystalline glass has a Vickers hardness of 700 kgf / mm². 2 ~800kgf / mm 2 The preferred value is 700 kgf / mm 2 ~750kgf / mm 2 .

[0017] In some embodiments of the present invention, the spinel microcrystalline glass contains SiO2 at a molar percentage of 38.50 mol% to 44.00 mol%; and / or Al2O3 at a molar percentage of 24.00 mol% to 27.50 mol%; and / or ZrO2 at a molar percentage of 3.00 mol% to 3.50 mol%; and / or MgO at a molar percentage of 5.00 mol% to 6.00 mol%; and / or ZnO at a molar percentage of 8.00 mol% to 10.00 mol%; and / or Na2O at a molar percentage of 3.00 mol% to 10.00 mol%; and / or B2O3 at a molar percentage of 3.50 mol% to 9.00 mol%.

[0018] In some embodiments of the present invention, when the amount of spinel microcrystalline glass with a main surface size of 50mm×50mm is removed by polishing with a polishing machine and the polishing liquid added to the polishing machine is a polishing liquid with a pH of 9.0 to 10.0, the polishing time is less than 640min, preferably less than 480min, and more preferably less than 400min.

[0019] In a second aspect, a method for preparing spinel microcrystalline glass is provided, comprising the following steps: heat-treating a substrate glass to form an easily machinable spinel microcrystalline glass; wherein the spinel microcrystalline glass contains a spinel as the main crystalline phase; and the composition of the spinel microcrystalline glass, expressed as a molar percentage of oxides, includes: SiO2 35.00 mol%–48.00 mol%, Al2O3 22.00 mol%–30.00 mol%, ZrO2 3.00 mol%–4.00 mol%, MgO 4.00 mol%–7.00 mol%, ZnO 8.00 mol%–11.00 mol%, Na2O 2.00 mol%–12.00 mol%, K2O 0.00 mol%–0.50 mol%, Li2O 0.00 mol%–4.00 mol%, and B2O3. 3.00mol%~10.00mol%, Y2O30.00mol%~1.00mol%, BaO 0.00mol%~2.00mol%.

[0020] In some embodiments of the present invention, the composition of the spinel microcrystalline glass, based on the molar percentage of oxides, satisfies: X = (5.23B₂O₃ + 1.52Na₂O + 1.33Li₂O) / (100% - ZrO₂ - 2MgO - 2ZnO), 0.460 ≤ X ≤ 1.000, preferably, 0.460 ≤ X ≤ 0.900; and / or, Y = Al₂O₃ / (MgO + ZnO), 1.000 ≤ Y ≤ 2.000, preferably, 1.600 ≤ Y ≤ 1.800; and / or, Z = (Na₂O + K₂O + Li₂O + B₂O₃) / (SiO₂ + Al₂O₃), 0.100 ≤ Z ≤ 0.500, preferably, 0.150 ≤ Z ≤ 0.300.

[0021] In some embodiments of the present invention, the spinel is (Zn,Mg)Al2O4, which is zinc-magnesium spinel, or zinc-magnesium spinel solid solution, and is a solid solution formed by zinc-aluminum spinel and magnesium-aluminum spinel; and / or, the spinel microcrystalline glass includes the secondary crystalline phase tetragonal ZrO2; and / or, the average grain size of the spinel microcrystalline glass is 3.00 nm to 25.00 nm, preferably 3.00 nm to 8.00 nm; and / or, the crystallinity of the spinel microcrystalline glass is 10.00 wt% to 50.00 wt%, preferably 30.00 wt% to 50.00 wt%; and / or, the spinel microcrystalline glass does not contain TiO2; and / or, the spinel microcrystalline glass is transparent in the visible light range.

[0022] In some embodiments of the present invention, the heat treatment includes nucleation treatment and crystallization treatment; the temperature of the nucleation treatment is 650℃~850℃, preferably 650℃~750℃, and the nucleation treatment time is 0h~72h, preferably 0h~24h; the temperature of the crystallization treatment is 700℃~1000℃, preferably 700℃~850℃, and the crystallization treatment time is 0.1h~72h, preferably 0.1h~24h; and / or, the heating rate during the heat treatment process is controlled to be 5K / min~30K / min, preferably 5K / min~15K / min.

[0023] Thirdly, a chemically strengthened glass-ceramic is provided, which is obtained by chemical strengthening treatment of the aforementioned spinel glass-ceramic, or by chemical strengthening treatment of spinel glass-ceramic prepared by the aforementioned preparation method.

[0024] In some embodiments of the present invention, the chemically strengthened microcrystalline glass is subjected to a high-temperature and high-humidity failure test at a temperature of 85°C and a relative humidity of 85%, and the high-temperature and high-humidity failure time is ≥360h. The high-temperature and high-humidity failure time is the total time from the start of the high-temperature and high-humidity test on the chemically strengthened microcrystalline glass to the appearance of spots or fog that cannot be wiped off in the chemically strengthened microcrystalline glass.

[0025] Fourthly, a glass device is provided, which is made of the aforementioned spinel microcrystalline glass, or spinel microcrystalline glass prepared by the aforementioned preparation method, or chemically strengthened microcrystalline glass.

[0026] Fifthly, an electronic device is provided, which includes the aforementioned spinel microcrystalline glass, or includes spinel microcrystalline glass prepared by the aforementioned preparation method, or includes the aforementioned chemically strengthened microcrystalline glass.

[0027] In a sixth aspect, a substrate glass for preparing the aforementioned spinel microcrystalline glass is provided, expressed as a molar percentage of oxides, wherein the composition of the substrate glass comprises: SiO2 35.00 mol%–48.00 mol%, Al2O3 22.00 mol%–30.00 mol%, ZrO2 3.00 mol%–4.00 mol%, MgO 4.00 mol%–7.00 mol%, ZnO 8.00 mol%–11.00 mol%, Na2O 2.00 mol%–12.00 mol%, K2O 0.00 mol%–0.50 mol%, Li2O 0.00 mol%–4.00 mol%, B2O3 3.00 mol%–10.00 mol%, Y2O3 0.00 mol%–1.00 mol%, and BaO 0.00 mol%–2.00 mol%.

[0028] In some embodiments of the present invention, the composition of the substrate glass, based on the molar percentage of oxides, satisfies: X = (5.23B₂O₃ + 1.52Na₂O + 1.33Li₂O) / (100% - ZrO₂ - 2MgO - 2ZnO), 0.460 ≤ X ≤ 1.000, preferably, 0.460 ≤ X ≤ 0.900; and / or, Y = Al₂O₃ / (MgO + ZnO), 1.000 ≤ Y ≤ 2.000, preferably, 1.600 ≤ Y ≤ 1.800; and / or,

[0029] Z = (Na2O + K2O + Li2O + B2O3) / (SiO2 + Al2O3), 0.100 ≤ Z ≤ 0.500, preferably, 0.150 ≤ Z ≤ 0.300; and / or, the substrate glass does not contain TiO2.

[0030] Beneficial effects of this invention:

[0031] This invention provides a transparent spinel microcrystalline glass with spinel as the main crystalline phase and excellent optical properties. Compared with existing spinel microcrystalline glasses, the spinel microcrystalline glass provided by this invention is easier to polish, has lower polishing difficulty, and higher polishing efficiency. By adjusting the glass formulation and utilizing the synergistic effect of specific amounts of various oxide components, this invention achieves the desired target crystalline phase while giving the microcrystalline glass a specific microstructure. This not only ensures the high intrinsic strength and excellent optical properties of the microcrystalline glass but also significantly reduces the polishing difficulty of the spinel microcrystalline glass while ensuring that its weather resistance meets the application requirements. This results in higher polishing efficiency and easier mass production. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0033] Figure 1 The DSC test curve of the substrate glass in Example 1;

[0034] Figure 2 The XRD diffraction pattern of the spinel glass-ceramic in Example 1;

[0035] Figure 3 The transmittance diagram of the 0.7 mm thick spinel microcrystalline glass in Example 1 under different wavelength conditions;

[0036] Figure 4aThe image shows the melting result of the substrate glass in Comparative Example 6;

[0037] Figure 4b This is an image of the spinel glass-ceramic in Comparative Example 7.

[0038] Figure 4c The image shows the melting result of the substrate glass in Comparative Example 8;

[0039] Figure 4d The image shows the melting result of the substrate glass in Comparative Example 9;

[0040] Figure 4e This is an image of the spinel glass-ceramic in Comparative Example 10. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art based on the present invention are within the scope of protection of the present invention.

[0042] Terminology Explanation

[0043] Substrate glass: refers to glass that has not undergone nucleation, crystallization, or strengthening treatments.

[0044] Glass-ceramics, also known as glass-ceramics, are a type of solid composite material containing both a glassy phase and a microcrystalline phase, prepared through targeted and controlled heat treatment of a substrate glass. The microcrystalline phase is also referred to as the crystalline phase, crystallized phase, or crystalline phase in other sources.

[0045] Chemically strengthened glass-ceramics: refers to solid composite materials 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 larger ionic radii (such as potassium and sodium ions) in the salt bath or molten salt will replace alkali metal ions with smaller ionic radii (such as sodium and lithium ions) in the glass-ceramics. This creates a volume difference in the exchanged ions, generating compressive stress from the surface to the interior of the glass-ceramics, which hinders and delays the propagation of microcracks, thereby improving the mechanical strength of the glass-ceramics.

[0046] Nucleation temperature: refers to the temperature at which crystal nuclei form.

[0047] Crystallization temperature: refers to the temperature at which the growth rate of the target crystal can be controlled.

[0048] Optical b-value: The optical b-value represents the yellow-blue value of the microcrystalline glass material.

[0049] In this invention, the optical b-value is the transmitted light b-value, which is the optical b-value of the material obtained by the testing instrument when the light-receiving optical system is in the transmission state. For example, a positive optical b-value indicates that the material is bluish.

[0050] Transmittance: When light of a certain wavelength shines on a glass surface, the light will be reflected, absorbed, and transmitted. The ratio of the intensity of the transmitted portion to the intensity of the incident light is the transmittance.

[0051] In this invention, the transmittance result of the microcrystalline glass under 550nm wavelength light refers to the average of the transmittance measured under 550nm wavelength light from multiple microcrystalline glass samples in the same batch. At least five samples from each batch of microcrystalline glass are tested. This invention uses a Konica Minolta CM-3600A spectrophotometer to test the transmittance of each microcrystalline glass sample under 550nm wavelength light.

[0052] Surface roughness: refers to the unevenness of a machined surface, characterized by small gaps and minute peaks and valleys.

[0053] Weather resistance refers to a sample's ability to withstand the combined damage caused by climate conditions such as sunlight, heat, cold, wind, rain, and bacteria. In this invention, the weather resistance of the sample is characterized by conducting high-temperature and high-humidity failure tests and examining the failure time under these conditions.

[0054] Vickers hardness: In this invention, Vickers hardness refers to a standard for expressing the hardness of materials proposed by Robert L. Smith and George E. Sandland in 1921 at Vickers Ltd.

[0055] Polishing removal amount: In this invention, polishing removal amount refers to the thickness of the microcrystalline glass sample that is thinned during polishing.

[0056] In this invention, when used to describe the constituent components of a composition, batch, melt, or article, the term "free of" means that it has not been actively added to or incorporated into the composition, batch, melt, or article, but may be present in the constituent components in an amount of less than about 0.01% (in molar percentage of oxides), which is due to the inherent uncertainty of any measurement or analysis technique.

[0057] Current theories suggest that the polishing mechanism of glass products mainly consists of the following three types:

[0058] (1) Mechanical action: The tangential force generated when the fine hard abrasive particles move relative to the glass surface is used to cut away the protruding parts of the glass surface by the hard abrasive particles, gradually forming a smooth surface.

[0059] (2) Chemical reaction: Under the combined action of polishing powder and water, a complex chemical reaction occurs on the glass surface, thus forming a smooth surface.

[0060] (3) Physicochemical action: High pressure and relative motion friction generate heat, causing plastic flow on the glass surface, which in turn causes the raised parts of the glass surface to fill the concave parts, thus forming a smooth surface.

[0061] In this field, the commonly used polishing method is to use polishing powder and polishing machine together to polish the surface of microcrystalline glass samples, which mainly utilizes the polishing mechanism that combines mechanical and chemical actions.

[0062] To address the challenge of surface polishing in existing spinel glass-ceramics, the inventors discovered two main reasons. Firstly, the high hardness of spinel glass-ceramics significantly complicates surface polishing. Specifically, ordinary lithium aluminum silicon crystals have a Mohs hardness of 5–6.5, and petaloid crystals have a Mohs hardness of 6–6.5, while spinel crystals have a Mohs hardness of 8. This clearly demonstrates that spinel's Mohs hardness is far greater than that of ordinary lithium aluminum silicon and petaloid crystals. Consequently, spinel glass-ceramics, with spinel as the main crystalline phase, have a much higher hardness than ordinary lithium aluminum silicon glass-ceramics, making polishing them significantly more difficult. Secondly, spinel glass-ceramics are less prone to forming a hydration layer during polishing. According to the inventors' research, the formation of a hydration layer through the reaction of water with the surface of the spinel glass-ceramics during polishing is a key factor affecting polishing efficiency. The lower the hardness of the hydration layer, the faster it forms, and the higher the efficiency of polishing the surface of spinel microcrystalline glass. However, existing spinel microcrystalline glass is difficult to polish due to the difficulty in forming a hydration layer during polishing, making rapid mass production difficult.

[0063] To address the aforementioned problems, this invention provides a spinel microcrystalline glass and a chemically strengthened microcrystalline glass made from the spinel microcrystalline glass, as well as glass devices comprising the aforementioned spinel microcrystalline glass or chemically strengthened microcrystalline glass, and electronic devices comprising the aforementioned spinel microcrystalline glass or chemically strengthened microcrystalline glass. This invention optimizes the formulation of the spinel microcrystalline glass, ensuring that its optical performance, mechanical properties, and weather resistance all meet the required standards. Furthermore, under conventional polishing conditions, the spinel microcrystalline glass exhibits a faster hydration layer formation rate and lower hydration layer hardness, thereby significantly improving the efficiency of polishing the surface of the spinel microcrystalline glass.

[0064] A first aspect of the present invention provides a spinel glass-ceramic, comprising a spinel as the main crystalline phase; the composition of the spinel glass-ceramic, expressed as a molar percentage of oxides, includes: SiO2 35.00 mol%–48.00 mol%, Al2O3 22.00 mol%–30.00 mol%, ZrO2 3.00 mol%–4.00 mol%, MgO 4.00 mol%–7.00 mol%, ZnO 8.00 mol%–11.00 mol%, Na2O 2.00 mol%–12.00 mol%, K2O 0.00 mol%–0.50 mol%, Li2O 0.00 mol%–4.00 mol%, B2O3 3.00 mol%–10.00 mol%, Y2O3 0.00 mol%–1.00 mol%, and BaO 0.00 mol%–2.00 mol%.

[0065] The inventors discovered that SiO2, as a forming oxide of the glass network, is an indispensable component in the formation of the glass network structure. In the formulation system of this invention, the addition of an appropriate amount of SiO2 can increase the stability and mechanical strength of the glass structure, but excessive SiO2 will increase the viscosity of the substrate glass, making glass melting more difficult and thus reducing the formability of the substrate glass. Therefore, in this invention, the SiO2 content, in mol%, is 35.00 mol% to 48.00 mol%, preferably 38.50 mol% to 44.00 mol%. Within the above range, the strength and processing performance of the spinel microcrystalline glass can be guaranteed, as well as the structural stability and formability of the spinel microcrystalline glass.

[0066] In some embodiments, the SiO2 content can be 35.00 mol%, 36.00 mol%, 37.00 mol%, 38.00 mol%, 38.50 mol%, 39.00 mol%, 40.00 mol%, 41.00 mol%, 42.00 mol%, 43.00 mol%, 44.00 mol%, 45.00 mol%, 46.00 mol%, 47.00 mol%, 48.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired performance of the present invention can be obtained. In this application, "embodiment" also means "implementation".

[0067] The inventors discovered that, in the formulation system of this invention, the appropriate addition of Al2O3 can not only promote the precipitation of the main crystalline phase spinel and inhibit the precipitation of impurity phases such as quartz that affect the optical properties of the spinel microcrystalline glass of this system, but also increase the ion exchange rate during the chemical strengthening process and promote ion exchange. However, excessive Al2O3 will drastically increase the difficulty of melting the substrate glass and accelerate the crystallization rate of the substrate glass, making it prone to crystallization devitrification during the normal cooling process of the substrate glass during melting. Therefore, in this invention, the content of Al2O3, in mol%, is 22.00 mol% to 30.00 mol%, preferably 24.00 mol% to 27.50 mol%.

[0068] In some embodiments, the Al2O3 content can be 22.00 mol%, 23.00 mol%, 24.00 mol%, 25.00 mol%, 26.00 mol%, 27.00 mol%, 27.50 mol%, 28.00 mol%, 29.00 mol%, 30.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired properties of the present invention is obtained.

[0069] The inventors discovered that in the formulation system of this invention, ZrO2 acts as a nucleating agent for spinel glass-ceramics. During the heat treatment of the substrate glass, ZrO2 precipitates first in crystalline form, and these ZrO2 crystals become nuclei, providing sustenance for the subsequent growth of spinel crystals. The content of ZrO2 not only affects the formation of the substrate glass but also influences the shape, type, and size of the crystals precipitated during the heat treatment of the substrate glass (here, the heat treatment process refers to the process of preparing the microcrystalline glass from the substrate glass), thereby affecting the microstructure of the microcrystalline glass. Therefore, in this invention, the ZrO2 content, in mol%, is 3.00 mol% to 4.00 mol%, preferably 3.00 mol% to 3.50 mol%.

[0070] In some embodiments, the ZrO2 content can be 3.00 mol%, 3.10 mol%, 3.20%, 3.30 mol%, 3.40 mol%, 3.50 mol%, 3.60 mol%, 3.70%, 3.80 mol%, 3.90 mol%, 4.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired properties of the present invention is obtained.

[0071] The inventors discovered that in the formulation system of this invention, MgO and ZnO, as the main components of the spinel crystalline phase, can promote the precipitation of the main crystalline phase spinel when added in appropriate amounts, thereby ensuring the acquisition of spinel glass-ceramics with high crystallinity / crystal content. This guarantees the spinel glass-ceramics have high intrinsic strength and can also reduce the melting difficulty of the substrate glass to some extent. However, excessive MgO and ZnO often lead to spinel grains growing very easily, making it difficult to guarantee high transparency of the spinel glass-ceramics. In other words, the content relationship between MgO and ZnO largely determines whether the glass-ceramic sample can be transparent and whether its optical properties and intrinsic strength are excellent. It should be understood that the composition and microstructure of the glass-ceramic are key factors determining its intrinsic strength, and the intrinsic strength of the glass-ceramic determines its ability to resist external damage. The higher the intrinsic strength, the stronger the ability of the glass-ceramic to resist external damage. Therefore, in this invention, the content of MgO is 4.00 mol% to 7.00 mol%, preferably 5.00 mol% to 6.00 mol%, and the content of ZnO is 8.00 mol% to 11.00 mol%, preferably 8.00 mol% to 10.00 mol%.

[0072] In some embodiments, the MgO content can be 4.00 mol%, 4.50 mol%, 5.00 mol%, 5.50 mol%, 6.00 mol%, 6.50 mol%, 7.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired properties of the present invention is obtained.

[0073] In some embodiments, the ZnO content can be 8.00 mol%, 8.50 mol%, 9.00 mol%, 9.50 mol%, 10.00 mol%, 10.50 mol%, 11.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired properties of the present invention is obtained.

[0074] The inventors discovered that in the formulation system of this invention, Li₂O, Na₂O, and K₂O, as network oxides in the formation of spinel microcrystalline glass, provide free oxygen, affecting the network structure of the glass and thus its intrinsic strength. On the other hand, Li₂O and Na₂O provide alkali metal ions to participate in ion exchange, which is beneficial for the chemical strengthening of spinel microcrystalline glass and thus improves its mechanical strength. Appropriate amounts of Na₂O and Li₂O help spinel microcrystalline glass achieve higher stress characteristics during chemical strengthening. However, excessive Li₂O and Na₂O can cause the substrate glass to become ceramic during melting and annealing, or cause the substrate glass to precipitate impurities that affect the optical properties of the spinel microcrystalline glass during heat treatment, thus reducing the transmittance of the prepared spinel microcrystalline glass. Furthermore, the addition of Li₂O, Na₂O, and K₂O is beneficial for reducing the high-temperature viscosity of the glass and promoting the melting and clarification of the molten glass. Therefore, in order to achieve a good balance between melting effect, optical properties, mechanical properties and stress properties, in this invention, the content of Na2O is 2.00 mol% to 12.00 mol%, preferably 3.00 mol% to 10.00 mol%; the content of K2O is 0.00 mol% to 0.50 mol%; and the content of Li2O is 0.00 mol% to 4.00 mol%.

[0075] In some embodiments, the Na₂O content can be 2.00 mol%, 3.00 mol%, 4.00 mol%, 5.00 mol%, 6.00 mol%, 7.00 mol%, 8.00 mol%, 9.00 mol%, 10.00 mol%, 11.00 mol%, 12.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired properties of the present invention is obtained.

[0076] In some embodiments, the K₂O content can be 0.00 mol%, 0.10 mol%, 0.20%, 0.30 mol%, 0.40 mol%, 0.50 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired properties of the present invention is obtained.

[0077] In some embodiments, the Li₂O content can be 0.00 mol%, 0.50 mol%, 1.00 mol%, 1.50 mol%, 2.00 mol%, 2.50 mol%, 3.00 mol%, 3.50 mol%, 4.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired performance of the present invention is obtained.

[0078] The inventors discovered that in the formulation system of this invention, B2O3 not only acts as a flux in the melting process of the substrate glass, reducing the difficulty of melting the substrate glass, but also helps to increase the hydration layer formation rate during the polishing process of spinel microcrystalline glass, thereby reducing the polishing difficulty and improving the polishing efficiency of spinel microcrystalline glass. However, the addition of excessive B2O3 often leads to the precipitation of impurity crystalline phases that affect the optical properties of spinel microcrystalline glass during the forming and crystallization process, causing the obtained spinel microcrystalline glass to exhibit opacity and affecting its transparency. Controlling the B2O3 content within the above-mentioned range is beneficial for obtaining transparent and easily polishable spinel microcrystalline glass. Therefore, in this invention, the B2O3 content, in mol%, is 3.00 mol% to 10.00 mol%, preferably 3.50 mol% to 9.00 mol%.

[0079] In some embodiments, the B2O3 content can be 3.00 mol%, 3.50 mol%, 4.00 mol%, 5.00 mol%, 6.00 mol%, 7.00 mol%, 8.00 mol%, 9.00 mol%, 10.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired properties of the present invention is obtained.

[0080] The inventors discovered that in the formulation system of this invention, an appropriate amount of Y₂O₃ can improve the network structure and formability of spinel glass-ceramics. However, excessive addition of Y₂O₃ increases the crystallization tendency of the substrate glass, easily leading to uncontrollable crystallization during the preparation of glass-ceramics from the substrate glass, thereby affecting the transmittance of the resulting glass-ceramics. Therefore, in this invention, the content of Y₂O₃ is 0.00 mol% to 1.00 mol%.

[0081] In some embodiments, the Y₂O₃ content can be 0.00 mol%, 0.10 mol%, 0.20%, 0.30 mol%, 0.40 mol%, 0.50 mol%, 0.60 mol%, 0.70%, 0.80 mol%, 0.90 mol%, 1.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired properties of the present invention is obtained.

[0082] The inventors discovered that in the formulation system of this invention, an appropriate amount of BaO can improve the melting effect of the substrate glass, but it has a strong inhibitory effect on Na-K exchange (referring to the exchange of Na ions in spinel glass-ceramics with K ions in the chemical strengthening salt bath), which is detrimental to obtaining excellent stress characteristics through chemical strengthening of spinel glass-ceramics. Therefore, in this invention, the content of BaO is 0.00 mol% to 2.00 mol%.

[0083] In some embodiments, the BaO content can be 0.00 mol%, 0.20%, 0.40 mol%, 0.60 mol%, 0.80 mol%, 0.90 mol%, 1.00 mol%, 1.20 mol%, 1.40 mol%, 1.60 mol%, 1.80 mol%, 2.00 mol%, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired properties of the present invention is obtained.

[0084] In some embodiments of the present invention, the composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following:

[0085] X = (5.23B₂O₃ + 1.52Na₂O + 1.33Li₂O) / (100% - ZrO₂ - 2MgO - 2ZnO), 0.460 ≤ X ≤ 1.000, preferred.

[0086] Earth, 0.460≤X≤0.900.

[0087] Through research, the inventors discovered that there is a certain correlation between the various oxide components in the formulation system of this invention, and this correlation affects the structure and properties of the glass-ceramic, as well as its subsequent processing.

[0088] In some embodiments, X can be 0.460, 0.500, 0.550, 0.600, 0.650, 0.700, 0.750, 0.800, 0.850, 0.900, 0.950, 1.000, or a value within a range defined by any two of the above values ​​as endpoints. In this invention, each substance in the above formula represents the molar percentage content of the corresponding substance; for example, B2O3 represents the molar percentage content of B2O3.

[0089] In some embodiments of the present invention, the composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies: Y = Al₂O₃ / (MgO + ZnO), 1.000 ≤ Y ≤ 2.000, preferably 1.600 ≤ Y ≤ 1.800; and / or, Z = (Na₂O + K₂O + Li₂O + B₂O₃) / (SiO₂ + Al₂O₃), 0.100 ≤ Z ≤ 0.500, preferably 0.150 ≤ Z ≤ 0.300. In the present invention, each substance in the above formula represents the molar percentage content of the corresponding substance; for example, Al₂O₃ represents the molar percentage content of Al₂O₃.

[0090] Through research, the inventors discovered that in the formulation system of this invention, Al2O3, MgO, and ZnO are all major components of the spinel crystal, the main crystalline phase of this invention. By adjusting the content relationship of Al2O3, MgO, and ZnO, this invention, on the one hand, ensures the acquisition of spinel microcrystalline glass with high crystal content / crystallinity, which is beneficial to improving the intrinsic strength of spinel microcrystalline glass; on the other hand, by leaving an appropriate amount of Al2O3 in the residual glass phase to form a [AlO4] tetrahedral structure, it is more conducive to achieving chemical strengthening of spinel microcrystalline glass, which is beneficial to obtaining high stress characteristics of spinel microcrystalline glass through chemical strengthening. This is because the volume of [AlO4] tetrahedron is larger than that of [SiO4], and the presence of an appropriate amount of [AlO4] is more conducive to widening ion exchange channels and promoting the diffusion of alkali metal ions.

[0091] Furthermore, in the formulation system of this invention, the content relationships of Na2O, K2O, Li2O, B2O3, SiO2, and Al2O3 are all related to the melting of the substrate glass, the construction of the glass network structure, the preparation of spinel microcrystalline glass, the machining of spinel microcrystalline glass, and the chemical strengthening of spinel microcrystalline glass. This invention, by adjusting the content relationships of each oxide, can better achieve an effective balance of multiple effects.

[0092] In some embodiments, the Al2O3 / (MgO+ZnO) ratio Y can be 1.000, 1.050, 1.100, 1.150, 1.200, 1.250, 1.300, 1.350, 1.400, 1.450, 1.500, 1.550, 1.600, 1.650, 1.700, 1.750, 1.800, 1.850, 1.900, 1.950, 2.000, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired performance of the present invention is obtained.

[0093] In some embodiments, the ratio Z of (Na2O+K2O+Li2O+B2O3) / (SiO2+Al2O3) can be 0.100, 0.150, 0.200, 0.250, 0.300, 0.350, 0.400, 0.450, 0.500, or a value within a range defined by any two of the above values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as the spinel microcrystalline glass with the desired performance of the present invention is obtained.

[0094] In some embodiments of the present invention, the spinel is (Zn,Mg)Al2O4, which is a zinc-magnesium spinel crystal, or a zinc-magnesium spinel solid solution, formed by zinc-aluminum spinel and magnesium-aluminum spinel; and / or, the spinel glass-ceramic includes the secondary crystalline phase tetragonal ZrO2. (Zn,Mg)Al2O4 possesses high Young's modulus and shear modulus, which is beneficial for improving the intrinsic strength of the spinel glass-ceramic and spinel glass-ceramic products of the present invention, for example, giving the spinel glass-ceramic and spinel glass-ceramic products high hardness, strength, fracture toughness, etc.

[0095] In some embodiments of the present invention, the average grain size of the spinel microcrystalline glass is 3.00 nm to 25.00 nm, preferably 3.00 nm to 8.00 nm. A suitable grain size is beneficial for inhibiting crack propagation and for achieving excellent optical performance in the spinel microcrystalline glass.

[0096] In some embodiments, the average grain size in the spinel glass-ceramic can be 3.00 nm, 4.00 nm, 5.00 nm, 6.00 nm, 7.00 nm, 8.00 nm, 9.00 nm, 10.00 nm, 11.00 nm, 12.00 nm, 13.00 nm, 14.00 nm, 15.00 nm, 16.00 nm, 17.00 nm, 18.00 nm, 19.00 nm, 20.00 nm, 21.00 nm, 22.00 nm, 23.00 nm, 24.00 nm, 25.00 nm, or a value within a range of values ​​defined by any two of the above values ​​as endpoints.

[0097] In some embodiments of the present invention, the crystallinity of the spinel microcrystalline glass is 10.00wt% to 50.00wt%, preferably 30.00wt% to 50.00wt%. A higher crystallinity / crystal content within a suitable range not only imparts higher intrinsic strength to the spinel microcrystalline glass, giving it and its products excellent mechanical properties, but also ensures its optical performance.

[0098] In some embodiments, the crystallinity of the spinel glass crystal can be 10.00wt%, 15.00wt%, 20.00wt%, 25.00wt%, 30.00wt%, 35.00wt%, 40.00wt%, 45.00wt%, 50.00wt%, or a value within a range of any two of the above values ​​as endpoints.

[0099] The inventors discovered that in the formulation system of this invention, the addition of TiO2 as a nucleating agent causes an undesirable color to appear in the substrate glass, which in turn affects the optical properties of the spinel microcrystalline glass. To obtain the desired transparent and colorless spinel microcrystalline glass, in some embodiments of this invention, it is preferable that the spinel microcrystalline glass does not contain TiO2.

[0100] In some embodiments of the present invention, the spinel microcrystalline glass is transparent in the visible light range. This transparency in the visible light range indicates that the spinel microcrystalline glass of the present invention can be used as a cover glass for electronic device displays.

[0101] In some embodiments of the present invention, at a thickness of 0.7 mm, the transmittance of the spinel microcrystalline glass for light at a wavelength of 550 nm is greater than or equal to 85.00%, preferably 85.00% to 95.00%, more preferably 88.00% to 95.00%; and / or, at a thickness of 0.7 mm, the optical b-value of the spinel microcrystalline glass is 0.20 to 1.50, preferably 0.20 to 1.20, more preferably 0.20 to 1.00.

[0102] In some embodiments, with a thickness of 0.7 mm, the transmittance of the spinel microcrystalline glass for light at a wavelength of 550 nm can be 85.00%, 86.00%, 87.00%, 88.00%, 89.00%, 90.00%, 91.00%, 92.00%, 93.00%, 94.00%, 95.00%, or a value within a range defined by any two of the above values ​​as endpoints. This demonstrates that the spinel microcrystalline glass provided by the present invention possesses excellent optical properties and high transparency.

[0103] In some embodiments, at a thickness of 0.7 mm, the optical b-value of the spinel microcrystalline glass can 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, 1.50, or a value within a range defined by any two of the above values ​​as endpoints. This demonstrates that the spinel microcrystalline glass provided by the present invention possesses excellent optical properties.

[0104] In some embodiments of the present invention, the Young's modulus of the spinel microcrystalline glass is 100 GPa to 150 GPa, preferably 110 GPa to 150 GPa.

[0105] In some embodiments, the Young's modulus of the spinel glass-ceramic can be 100 GPa, 105 GPa, 110 GPa, 115 GPa, 120 GPa, 125 GPa, 130 GPa, 135 GPa, 140 GPa, 145 GPa, 150 GPa, or a value within a range defined by any two of the above values ​​as endpoints. This indicates that the spinel glass-ceramic provided by the present invention has high intrinsic strength and excellent mechanical properties.

[0106] In some embodiments of the present invention, the Vickers hardness of the spinel microcrystalline glass is 700 kgf / mm². 2 ~800kgf / mm 2 The preferred value is 700 kgf / mm 2 ~750kgf / mm 2 .

[0107] In some implementations, the Vickers hardness can be 700 kgf / mm. 2 710kgf / mm 2 720kgf / mm 2 730kgf / mm 2 740kgf / mm 2 750kgf / mm 2 760kgf / mm 2 770kgf / mm2 780kgf / mm 2 790kgf / mm 2 800kgf / mm 2 Or values ​​within a range defined by any two of the above values ​​as endpoints. This demonstrates that the spinel microcrystalline glass provided by the present invention possesses high intrinsic strength and excellent mechanical properties.

[0108] In some embodiments of the present invention, the spinel microcrystalline glass contains SiO2 at a molar percentage of 38.50 mol% to 44.00 mol%; and / or Al2O3 at a molar percentage of 24.00 mol% to 27.50 mol%; and / or ZrO2 at a molar percentage of 3.00 mol% to 3.50 mol%; and / or MgO at a molar percentage of 5.00 mol% to 6.00 mol%; and / or ZnO at a molar percentage of 8.00 mol% to 10.00 mol%; and / or Na2O at a molar percentage of 3.00 mol% to 10.00 mol%; and / or B2O3 at a molar percentage of 3.50 mol% to 9.00 mol%. That is, the composition of spinel glass-ceramics satisfies at least one of the following: SiO2 molar percentage of 38.50 mol% to 44.00 mol%, Al2O3 molar percentage of 24.00 mol% to 27.50 mol%, ZrO2 molar percentage of 3.00 mol% to 3.50 mol%, MgO molar percentage of 5.00 mol% to 6.00 mol%, ZnO molar percentage of 8.00 mol% to 10.00 mol%, Na2O molar percentage of 3.00 mol% to 10.00 mol%, and B2O3 molar percentage of 3.50 mol% to 9.00 mol%. Further optimization of the spinel microcrystalline glass formulation can not only ensure that the optical properties, mechanical properties and high temperature and humidity resistance (which can characterize weather resistance) of the spinel microcrystalline glass meet the requirements, but also facilitate the production of spinel microcrystalline glass with low polishing difficulty and high polishing efficiency, making it easier to achieve mass production of spinel microcrystalline glass.

[0109] In some embodiments of the present invention, when a polishing machine is used to polish the spinel microcrystalline glass with a main surface size of 50mm × 50mm and the amount of material removed is 0.08mm, and the polishing liquid added to the polishing machine is a polishing liquid with a pH of 9.0 to 10.0, the polishing time is less than 640 minutes, preferably less than 480 minutes, and more preferably less than 400 minutes. This demonstrates that the spinel microcrystalline glass provided by the present invention is easier to polish and has higher polishing efficiency compared to spinel microcrystalline glass in the prior art. Here, "main surface" refers to the upper and lower surfaces when the microcrystalline glass sheet is placed horizontally.

[0110] In this invention, those skilled in the art can select the thickness of the spinel microcrystalline glass according to their needs, and this invention does not limit this. Exemplarily, the thickness of the spinel microcrystalline glass can be 0.1mm to 5.0mm, preferably 0.1mm to 2.0mm. Exemplarily, the thickness of the spinel microcrystalline glass can be 0.1mm, 0.2mm, 0.5mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.5mm, 1.6mm, 1.8mm, 2.0mm, 2.5mm, 2.8mm, 3.0mm, 3.5mm, 3.8mm, 4.0mm, 4.5mm, 4.8mm, 5.0mm, or a value within a range defined by any two of the above values ​​as endpoints.

[0111] A second aspect of the present invention provides a method for preparing the spinel microcrystalline glass according to any of the foregoing embodiments, comprising the following steps: heat-treating a substrate glass to form an easily machinable spinel microcrystalline glass; wherein the spinel microcrystalline glass contains a spinel as the main crystalline phase; and the composition of the spinel microcrystalline glass, expressed as a molar percentage of oxides, includes: SiO2 35.00 mol%–48.00 mol%, Al2O3 22.00 mol%–30.00 mol%, ZrO2 3.00 mol%–4.00 mol%, MgO 4.00 mol%–7.00 mol%, ZnO 8.00 mol%–11.00 mol%, Na2O 2.00 mol%–12.00 mol%, K2O 0.00 mol%–0.50 mol%, Li2O 0.00 mol%–4.00 mol%, and B2O3. 3.00mol%~10.00mol%, Y2O30.00mol%~1.00mol%, BaO 0.00mol%~2.00mol%.

[0112] It should be understood that, in terms of oxide mol%, the composition of the substrate glass is the same as that of the spinel microcrystalline glass of the present invention.

[0113] In some embodiments of the present invention, the composition of the spinel microcrystalline glass, based on the molar percentage of oxides, satisfies: X = (5.23B₂O₃ + 1.52Na₂O + 1.33Li₂O) / (100% - ZrO₂ - 2MgO - 2ZnO), 0.460 ≤ X ≤ 1.000, preferably, 0.460 ≤ X ≤ 0.900; and / or, Y = Al₂O₃ / (MgO + ZnO), 1.000 ≤ Y ≤ 2.000, preferably, 1.600 ≤ Y ≤ 1.800; and / or, Z = (Na₂O + K₂O + Li₂O + B₂O₃) / (SiO₂ + Al₂O₃), 0.100 ≤ Z ≤ 0.500, preferably, 0.150 ≤ Z ≤ 0.300.

[0114] In some embodiments of the present invention, the spinel is (Zn,Mg)Al2O4, which is zinc-magnesium spinel, or zinc-magnesium spinel solid solution, and is a solid solution formed by zinc-aluminum spinel and magnesium-aluminum spinel; and / or, the spinel microcrystalline glass includes the secondary crystalline phase tetragonal ZrO2; and / or, the average grain size of the spinel microcrystalline glass is 3.00 nm to 25.00 nm, preferably 3.00 nm to 8.00 nm; and / or, the crystallinity of the spinel microcrystalline glass is 10.00 wt% to 50.00 wt%, preferably 30.00 wt% to 50.00 wt%; and / or, the spinel microcrystalline glass does not contain TiO2; and / or, the spinel microcrystalline glass is transparent in the visible light range.

[0115] In some embodiments of the present invention, the heat treatment includes nucleation treatment and crystallization treatment. The temperature of the nucleation treatment is 650℃~850℃, preferably 650℃~750℃, and the nucleation treatment time is 0h~72h, preferably 0h~24h. The temperature of the crystallization treatment is 700℃~1000℃, preferably 700℃~850℃, and the crystallization treatment time is 0.1h~72h, preferably 0.1h~24h. And / or, the heating rate during the heat treatment process is controlled to be 5K / min~30K / min, preferably 5K / min~15K / min.

[0116] It should be understood that heat treatment of the substrate glass can be performed in one step, two steps, or multiple steps. A one-step heat treatment means that nucleation is not performed separately; nucleation and target crystal growth are carried out directly in a single heating process, which can be understood as direct crystallization. A two-step heat treatment means that two heating processes are performed: first nucleation (nucleation treatment), and then target crystal growth (crystallization treatment). In a multi-step heat treatment, the nucleation and / or crystallization stages employ a stepped heating method, meaning that the entire heat treatment process involves multiple (more than two) heating stages. It should be understood that in this invention, the nucleation treatment involves heating to a specified nucleation temperature (also called nucleation temperature) and holding at that temperature for a certain period of time; this holding time is the nucleation treatment time (also called nucleation time). The crystallization process involves heating the temperature to a specified crystallization temperature (also known as the crystallization temperature) and then holding the temperature for a certain period of time after reaching the crystallization temperature. This holding time is called the crystallization time.

[0117] In some embodiments, the nucleation treatment temperature can be 650°C, 675°C, 700°C, 725°C, 750°C, 775°C, 800°C, 825°C, 850°C, or a value within a range defined by any two of the above values. The nucleation treatment time can be 0h, 12h, 24h, 36h, 48h, 60h, 72h, or a value within a range defined by any two of the above values. By controlling the nucleation treatment temperature and time within the above ranges, the formation of crystal nuclei can be controlled, which is beneficial for obtaining spinel microcrystalline glass that meets the requirements in subsequent crystallization processes, such as hardness, intrinsic strength, transmittance, and polishing efficiency.

[0118] In some embodiments, the crystallization temperature can be 700℃, 725℃, 750℃, 775℃, 800℃, 825℃, 850℃, 875℃, 900℃, 925℃, 950℃, 975℃, 1000℃, or a value within a range defined by any two of the above values. The crystallization time can be 0.1h, 12h, 24h, 36h, 48h, 60h, 72h, or a value within a range defined by any two of the above values. By controlling the crystallization temperature and crystallization time within the above ranges, it is beneficial to grow spinel crystals of suitable size, resulting in spinel microcrystalline glass that meets the requirements for hardness, intrinsic strength, transmittance, and polishing efficiency.

[0119] A third aspect of the present invention provides a chemically strengthened glass-ceramic, which is obtained by chemical strengthening treatment of the aforementioned spinel glass-ceramic, or by chemical strengthening treatment of spinel glass-ceramic prepared by the aforementioned preparation method.

[0120] The above-described chemical strengthening process can employ any chemical strengthening process known in the art, and this invention is not limited thereto. Exemplarily, the spinel microcrystalline glass of this invention can be chemically strengthened by placing it in a salt bath containing potassium salt for a certain period of time to obtain the chemically strengthened microcrystalline glass. The salt bath temperature can be 380℃~600℃, and the salt bath may also contain sodium salt and 0wt%~1wt% lithium salt. The potassium salt includes at least one of potassium nitrate, potassium sulfate, or potassium carbonate, preferably potassium nitrate; the sodium salt includes at least one of sodium nitrate, sodium sulfate, or sodium carbonate, preferably sodium nitrate; the lithium salt includes at least one of lithium nitrate, lithium sulfate, or lithium carbonate, preferably lithium nitrate. The above-described salt bath is a molten salt bath.

[0121] For the chemically strengthened glass-ceramics of the present invention: ion exchange forms a compressive stress layer of a certain depth on the surface of the spinel glass-ceramics, while a tensile stress layer capable of achieving force balance with the compressive stress layer is formed inside the spinel glass-ceramics. It should be understood that after chemical strengthening treatment, the composition at the surface of the glass-ceramics may differ from the composition of freshly formed glass-ceramics (i.e., glass-ceramics without ion exchange). That is, in the chemically strengthened glass-ceramics made from the spinel glass-ceramics described above, the composition of the compressive stress layer formed on the surface through ion exchange may differ from the composition of the spinel glass-ceramics. This is because during ion exchange, a certain type of alkali metal ion (e.g., Li) in the freshly formed glass-ceramics... + Or Na + ) will be affected by larger alkali metal ions (e.g., Na) + or K + Replaced by, for example, Na in glass-ceramics + With K in the salt bath + To exchange, K + The Li replaced, and / or, in the glass-ceramic + With Na in the salt bath + To exchange, by Na + However, in embodiments, the composition of the glass-ceramic at or near the center of the depth of the glass article will still have the composition of the newly formed glass-ceramic. That is, in the chemically strengthened glass-ceramic obtained by the spinel glass-ceramic described above in this invention, the composition of the tensile stress layer formed inside will still have the composition of the spinel glass-ceramic described above in this invention.

[0122] In this invention, since the chemical strengthening process involves the exchange of alkali metal ions (such as lithium ions, sodium ions, and potassium ions), and the main crystalline phase of the spinel microcrystalline glass of this invention 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 composition of the main crystalline phase and the secondary crystalline phase in the spinel microcrystalline glass remains basically unchanged before and after strengthening.

[0123] In some embodiments of the present invention, the chemically strengthened microcrystalline glass of the present invention is subjected to a high-temperature and high-humidity failure test at a temperature of 85°C and a relative humidity of 85%. The high-temperature and high-humidity failure time is ≥360 hours, which is the total time from the start of the high-temperature and high-humidity test to the appearance of spots or haze that cannot be wiped off in the chemically strengthened microcrystalline glass. This demonstrates that the chemically strengthened microcrystalline glass provided by the present invention has excellent high-temperature and high-humidity resistance, and thus its excellent weather resistance can be characterized.

[0124] The high-performance spinel microcrystalline glass and chemically strengthened microcrystalline glass provided by this invention can be used in various applications, such as worktops, other surfaces, covers for consumer electronics devices, appliance doors, floor tiles, wall panels, ceiling tiles, whiteboards, and storage containers. Other surfaces may include, but are not limited to, exterior wall surfaces, stair tread surfaces, column cladding, and counter surfaces. Consumer electronics devices may include, but are not limited to, handheld, desktop-mounted, and wall-mounted devices. Covers may include, but are not limited to, mobile phone covers, mobile phone back panels, tablet computer back panels, and wristband covers. Storage containers may include, but are not limited to, plates and beverage bottles.

[0125] A fourth aspect of the present invention provides a glass device made from the aforementioned spinel microcrystalline glass, or from spinel microcrystalline glass prepared by the aforementioned preparation method, or from the aforementioned chemically strengthened microcrystalline glass. For example, the glass device may include, but is not limited to, mobile phone display protective covers, mobile phone battery back covers, laptop screen protective covers, and automotive center console glass covers.

[0126] A fifth aspect of the present invention provides an electronic device comprising the aforementioned spinel microcrystalline glass, or spinel microcrystalline glass prepared by the aforementioned preparation method, or chemically strengthened microcrystalline glass. For example, the electronic device may include, but is not limited to, mobile phones, tablet computers, smart wearables, displays, or televisions. Smart wearables may include, but are not limited to, electronic watches, smart bracelets, smartwatches, and smart glasses; displays may include, but are not limited to, high-definition displays, automotive displays, and aerial displays.

[0127] For example, an electronic device may include a housing and electronic components partially located within the housing. The housing includes a front surface, a rear surface, and a side surface. The electronic components include a display device located on or adjacent to the front surface of the housing. The chemically strengthened microcrystalline glass provided by the present invention can be applied to the front surface and / or the rear surface and / or the side surface of the housing. Preferably, the electronic device may further include a cover article covering the front surface of the housing or located on the display device. The chemically strengthened microcrystalline glass provided by the present invention can be applied to the cover article.

[0128] A sixth aspect of the present invention provides a substrate glass, which, after heat treatment and crystallization, can be used to prepare the aforementioned spinel microcrystalline glass; the composition of the substrate glass, expressed as a molar percentage of oxides, includes: SiO2 35.00 mol%–48.00 mol%, Al2O3 22.00 mol%–30.00 mol%, ZrO2 3.00 mol%–4.00 mol%, MgO 4.00 mol%–7.00 mol%, ZnO 8.00 mol%–11.00 mol%, Na2O 2.00 mol%–12.00 mol%, K2O 0.00 mol%–0.50 mol%, Li2O 0.00 mol%–4.00 mol%, B2O3 3.00 mol%–10.00 mol%, Y2O3 0.00 mol%–1.00 mol%, and BaO 0.00 mol%–2.00 mol%.

[0129] In some embodiments of the present invention, the composition of the substrate glass, based on the molar percentage of oxides, satisfies: X = (5.23B2O3 + 1.52Na2O + 1.33Li2O) / (100% - ZrO2 - 2MgO - 2ZnO), 0.460 ≤ X ≤ 1.000, preferably, 0.460 ≤ X ≤ 0.900.

[0130] In some embodiments of the present invention, the composition of the substrate glass, based on the molar percentage of oxides, satisfies: Y = Al2O3 / (MgO + ZnO), 1.000 ≤ Y ≤ 2.000, preferably 1.600 ≤ Y ≤ 1.800; and / or, Z = (Na2O + K2O + Li2O + B2O3) / (SiO2 + Al2O3), 0.100 ≤ Z ≤ 0.500, preferably 0.150 ≤ Z ≤ 0.300; and / or, the substrate glass does not contain TiO2.

[0131] In this invention, the substrate glass can be prepared using conventional methods known in the art, and this invention does not limit this method. In some embodiments of this invention, the substrate glass is formed by processes including but not limited to float glass, overflow glass, calendering, or casting.

[0132] In some embodiments of the present invention, when preparing the substrate glass, a clarifying agent may be added to the raw materials for preparing the substrate glass. The clarifying agent includes, but is not limited to, at least one of SnO2, Sb2O3, and NaCl. Based on the total mass of the raw materials for the substrate glass, the amount of clarifying agent added is 0.01wt% to 2.00wt%, preferably 0.01wt% to 1.50wt%. For example, the amount of clarifying agent added can be 0.01wt%, 0.20wt%, 0.40wt%, 0.80wt%, 1.00wt%, 1.20wt%, 1.40wt%, 1.60wt%, 1.80wt%, 2.00wt%, or a value within a range of values ​​defined by any two of the above values ​​as endpoints.

[0133] In some embodiments of the present invention, the preparation process of the substrate glass is as follows: after mixing the raw materials according to the formula, a clarifying agent is added, and the mixture is melted at 1480℃~1650℃ for 3h~24h, preferably 3h~6h. After the melting treatment is completed, the glass liquid is poured into a mold to form a shape. After cooling to 850℃~1000℃, preferably, it is placed in an annealing furnace for annealing treatment at a temperature of 500℃~650℃. The annealing temperature is maintained for 12h~72h, and then the glass is cooled to room temperature with the furnace to obtain the substrate glass.

[0134] In some embodiments, the melting temperature of the substrate glass can be 1480°C, 1500°C, 1520°C, 1540°C, 1560°C, 1580°C, 1600°C, 1620°C, 1650°C, or a value within a range defined by any two of the above values. In some embodiments, the melting time of the substrate glass can be 3h, 3.5h, 4.0h, 4.5h, 5.0h, 5.5h, 6.0h, 8.0h, 10.0h, 12.0h, 14.0h, 16.0h, 18.0h, 20.0h, 22.0h, 24.0h, or a value within a range defined by any two of the above values. In some embodiments, the substrate glass, after molding, can be cooled to 850°C, 875°C, 900°C, 925°C, 950°C, 975°C, 1000°C, or a value within a range defined by any two of the above values. In some embodiments, the annealing temperature of the substrate glass can be 500°C, 525°C, 550°C, 575°C, 600°C, 625°C, 650°C, or a value within a range defined by any two of the above values. In some embodiments, the annealing holding time of the substrate glass can be 12h, 22h, 32h, 42h, 52h, 62h, 72h, or a value within a range defined by any two of the above values.

[0135] Test method:

[0136] 1. DSC test

[0137] The substrate glass was crushed, ground, and sieved through a 200-mesh sieve to obtain a sample. 20 mg of the sample was then weighed and heated from room temperature to 1100 °C at a rate of 10 °C / min using a differential thermal analysis (DTA) instrument under a nitrogen protective atmosphere to obtain the DSC test curve. The DTA instrument used in this invention was a Mettler Toledo TGA / DSC3+ thermogravimetric and simultaneous thermal analyzer. The standard used for testing was α-Al₂O₃ powder, and the sample was placed in a platinum crucible. The ambient temperature and humidity of the instrument were 24 °C and 40%, respectively.

[0138] 2. XRD Testing

[0139] Microcrystalline glass was pulverized and ground into samples with a particle size of less than 75 μm. The ground samples were then tested using an X-ray diffractometer to obtain XRD diffraction peak curves and XRD diffraction data. The crystal phase of the sample was then determined using Jade software. The X-ray diffractometer used was a Shimadzu XRD-6100, with an incident angle range of 2θ = 10°–80°, a scanning speed of 6° / min, an operating voltage of 40 kV, and an operating current of 30 mA.

[0140] Average grain size: Using the XRD test results, the average grain size of the sample can be calculated according to the Scherrer formula D = Kλ / (βcosθ). Here, λ is the X-ray wavelength (λ = 0.154056 nm), β is the full width at half maximum (FWHM) of the diffraction peak (K = 0.89), and θ is the Bragg diffraction angle. Specifically, the RAW file (diffraction pattern) output from the XRD instrument is curve-fitted in Jade software. Jade outputs a fitting report. Based on the angle 2θ and PeakFWHM value (FWHM value) corresponding to each diffraction peak in the fitting report, and converting the PeakFWHM value to radians: β = (FWHM / 180 × 3.14), the grain size of each diffraction peak is calculated using the Scherrer formula D = Kλ / (βcosθ), and then averaged to obtain the average grain size.

[0141] Crystallinity: Also known as crystal content. The crystallinity of a glass-ceramic sample can be obtained by importing the XRD test results (RAW format) into the Rietveld X-ray diffraction data refinement software Jade for fitting and calculation. Specifically, the ratio of the fitted crystalline phase peak area to the total fitted peak area is the crystallinity of the glass-ceramic.

[0142] 3. Thickness test

[0143] The thickness of the glass-ceramic was measured using a micrometer. Specifically, five points on the glass-ceramic sheet were selected for thickness measurement, and the average value of the five measurements was taken as the thickness of the glass-ceramic sheet. The five selected points were located at the center of the glass-ceramic sheet and near its four corners.

[0144] It should be understood that during chemical strengthening, the degree of ion exchange in the thickness direction of the glass-ceramic varies gradient from the surface to the center. The total Na-K and / or Li-Na exchange amounts generally do not exceed 1% of the total sample mass, and the differences in ion radii are all on the order of picometers (pm). Therefore, the expansion effect in the thickness direction is extremely slight, and the thickness can be approximated as essentially unchanged. In other words, the thickness change of the glass-ceramic before and after chemical strengthening is very small.

[0145] 4. Optical performance testing

[0146] Referring to the national standard GB / T 7962.12-2010 "Test Methods for Colorless Optical Glass - Part 12: Internal Spectral Transmittance", a haze meter was used to test the transmittance and optical b-value of the microcrystalline glass. Specifically, the transmittance and optical b-value of five microcrystalline glass pieces from the same batch for different wavelengths of light were measured using a haze meter. The transmittance of the five microcrystalline glass pieces measured at 550 nm wavelength was averaged, and the average value was taken as the transmittance of the batch of microcrystalline glass at 550 nm wavelength. The optical b-value of the five microcrystalline glass pieces was averaged, and the average value was taken as the optical b-value of the batch of microcrystalline glass.

[0147] The haze meter used in the test of this invention is a Konica Minolta CM-3600A spectrophotometer from Japan. The light receiving optical system is transmission, the spectral dispersive method is a planar refracting grating, the wavelength range is 360nm~740nm, the wavelength spacing is 10nm, the illumination source is a pulsed xenon lamp X4, the ambient temperature of the instrument is 24℃, and the air humidity is 40%.

[0148] 5. Young's modulus test

[0149] The Young's modulus of glass-ceramics was tested using the UMS-100 ultrasonic material characterization system via acoustic waves.

[0150] 6. Vickers hardness test

[0151] Microcrystalline glass was fabricated into small pieces with dimensions of 50mm × 50mm × 0.70mm. Glass samples with clean surfaces and free from visible scratches, dents, cracks, or other damage were selected as test samples. The Vickers hardness was then measured using a Vickers hardness tester. The Vickers hardness tester used in this invention was a digital display low-load Vickers hardness tester, model VTD405, manufactured by Beijing Kewei Technology Co., Ltd. Test conditions: load 300gf, loading time 10s, and the validity of the indentation conformed to the standard "GB / T37900-2019 Test Method for Hardness and Fracture Toughness of Ultra-thin Glass: Low-load Vickers Hardness Indentation Method".

[0152] Three different locations were selected on the surface of the same test sample for measurement, and the average value of the three measurement results was taken as the Vickers hardness result of the test sample.

[0153] 7. High temperature and high humidity failure test

[0154] In this invention, the high-temperature and high-humidity failure time of chemically strengthened glass-ceramics is tested under conditions of a test temperature of 85°C and a relative humidity of 85%. The high-temperature and high-humidity failure time is the total time from the start of the high-temperature and high-humidity test on the chemically strengthened glass-ceramics to the appearance of spots or haze that cannot be wiped off in the chemically strengthened glass-ceramics.

[0155] Specifically: Chemically strengthened glass-ceramic samples were placed in a temperature and humidity alternating test chamber at 85°C and 85% relative humidity, and the initial placement time was recorded. Every 12 hours thereafter, the samples were removed, and their surfaces were wiped with a lint-free cloth. The presence of irremovable spots and / or haze was observed. If no irremovable spots or haze appeared, the samples were placed back into the chamber for further observation until irremovable spots and / or haze were observed. The sampling time at which irremovable spots and / or haze appeared was recorded. This sampling time, minus the initial placement time, was recorded as the high-temperature and high-humidity failure time of the chemically strengthened glass-ceramic sample, used to characterize its weather resistance. For example, if spots and / or fog spots that cannot be wiped off appear in the sample during this sampling observation, while no such spots and / or fog spots appear in the sample during the previous sampling observation, then the high temperature and high humidity failure time of the chemically strengthened microcrystalline glass sample is recorded as the current sampling time minus the initial placement time.

[0156] The temperature and humidity alternating test chamber used in this invention is the QTH_80C All One temperature and humidity alternating test chamber, and the maximum test time is 360 hours, or 15 days. If, after 360 hours of testing, no spots and / or fogging that cannot be wiped off appear in the chemically strengthened glass-ceramic sample, then the high temperature and high humidity failure time of the glass-ceramic sample is determined to be greater than 360 hours.

[0157] 8. Density test

[0158] This invention uses an ALFA MIRAGE SD-200L electronic density balance from Japan to test the density of microcrystalline glass. The testing principle is based on Archimedes' method of water displacement.

[0159] Example 1

[0160] <Preparation of Substrate Glass>

[0161] According to Formula 1 in Table 1, the raw materials for spinel microcrystalline glass production were prepared by mixing 1000g of raw materials. The mixture was then mixed in a V-type mixer for 30 minutes. After mixing, 5g of clarifying agent NaCl was added, and the mixture was then transferred to a platinum crucible and melted in a 1650℃ heating furnace for 5 hours. The mixture was then poured into a molding mold and cooled to 900℃. Finally, it was placed in a 600℃ annealing furnace for 24 hours and then cooled to room temperature in the furnace to obtain the substrate glass.

[0162] like Figure 1 As shown, in the DSC test spectrum of the substrate glass prepared above, the temperature of the first endothermic peak is 718℃ and the temperature of the first exothermic peak is 856℃.

[0163] <Preparation of Spinel Glass-Ceramic>

[0164] The substrate glass prepared above was heat-treated in a resistance furnace (equipment model: SLX1400-40, manufacturer: Shanghai Shengli Test Instrument Co., Ltd.). The heat treatment process (nucleation temperature T1, nucleation time t1, crystallization temperature T2, crystallization time t2, and heating rate of the heat treatment process) was carried out according to Table 2.

[0165] The heat treatment process in Example 1 was as follows: the nucleation treatment temperature T1 was 740℃, and the nucleation treatment time t1 was 4 hours; the crystallization treatment temperature T2 was 790℃, and the crystallization treatment time t2 was 4 hours. During the heat treatment, the heating rate was controlled at 10K / min. That is, the substrate glass was first heated to the nucleation treatment temperature of 740℃ at a heating rate of 10K / min for nucleation treatment, and the nucleation treatment time was 4 hours; then, it was heated to the crystallization treatment temperature of 790℃ at a heating rate of 10K / min for crystallization treatment, and the crystallization treatment time was 4 hours, resulting in a spinel microcrystalline glass sample brick.

[0166] Processing of spinel microcrystalline glass

[0167] The spinel microcrystalline glass sample bricks prepared above were shaped, cut, ground, and CNC machined to obtain spinel microcrystalline glass frosted sheets with a length, width, and thickness of 50mm×50mm×0.78mm. Then, the surface of the spinel microcrystalline glass frosted sheets was polished to obtain spinel microcrystalline glass polished sheets with a length, width, and thickness of 50mm×50mm×0.70mm.

[0168] The specific polishing process is as follows:

[0169] The prepared spinel microcrystalline glass frosting sheet was placed horizontally in the epoxy plate of the polishing disc of a polishing machine (model YJ-13B6PD, manufactured by Hunan Yujing Machinery Co., Ltd.), ensuring that there were no foreign objects on the upper and lower surfaces of the frosting sheet. The processing parameters of the polishing machine were set as follows: first stage processing pressure 50 kg, lower disc speed 10 rpm; second stage processing pressure 100 kg, lower disc speed 20 rpm; third stage processing pressure 50 kg, lower disc speed 10 rpm. Polishing fluid was added for polishing treatment, with the flow rate adjusted to 3 L / min, pH 9.5, and polishing removal amount adjusted to 0.08 mm, until a spinel microcrystalline glass polishing sheet with dimensions of 50 mm × 50 mm × 0.70 mm was obtained. The polishing time was recorded. The water-powder concentration of the polishing fluid used in this invention was 1.13 ± 0.03 g / ml, and the pH was 9.53 ± 0.05. The polishing powder used in the preparation of the water-powder was TB-2825 white polishing powder from Dongguan Taixin Abrasive Materials Co., Ltd. During polishing, pay attention to whether there is any blockage in the dual powder water pipes, and ensure that the amount of water and powder flowing out is uniform.

[0170] Examples 2 to 5

[0171] Except for adjusting the formula according to Table 1 and the relevant preparation parameters according to Table 2, everything else is the same as in Example 1.

[0172] Example 6

[0173] <Preparation of Chemically Strengthened Microcrystalline Glass>

[0174] The spinel microcrystalline glass sample (i.e., the polished spinel microcrystalline glass) obtained in Example 1 was chemically strengthened in a mixed salt bath containing 30wt% NaNO3 and 70wt% KNO3 at a temperature T3 of 480℃ for a strengthening time t3 of 24h, thus obtaining chemically strengthened microcrystalline glass.

[0175] Examples 7 to 10

[0176] Except for adjusting the relevant preparation parameters according to Table 3, the rest is the same as in Example 6.

[0177] Comparative Examples 1 to 11

[0178] Except for adjusting the formula according to Table 1 and the relevant preparation parameters according to Table 2, everything else is the same as in Example 1.

[0179] Comparative Examples 12 to 16

[0180] Except for adjusting the relevant preparation parameters according to Table 3, the rest is the same as in Example 6.

[0181] The formulations, preparation parameters, and performance tests for each embodiment and comparative example are shown in Tables 1 to 3.

[0182] Table 1

[0183]

[0184] Note: The content of each substance in Table 1 is a molar percentage, i.e., mol%. “ / ” indicates that the component was not actively or intentionally added to the glass composition during the initial batching process, but the component may exist as an impurity.

[0185]

[0186]

[0187] Table 3

[0188]

[0189] Note: Since the maximum time for high temperature and high humidity failure testing in this invention is 360 hours (15 days), if the chemically strengthened glass-ceramic sample is taken out after 360 hours and no spots and / or fog spots that cannot be wiped off are still observed in the sample, it is determined that the high temperature and high humidity failure time of the chemically strengthened glass-ceramic sample is greater than 360 hours.

[0190] Referring to Table 2, the formulations of the spinel microcrystalline glass in Examples 1 to 5 are within the scope of this invention, while the glass formulations of Comparative Examples 1 to 11 are not. The spinel microcrystalline glass obtained in the embodiments of this invention exhibits significantly reduced polishing difficulty, shorter polishing time, and significantly improved polishing efficiency. Comparative Example 1 is a lithium aluminum silicon microcrystalline glass, which has high polishing efficiency. The formulations in Comparative Examples 2 to 5 do not meet the limitations of this invention, resulting in spinel microcrystalline glass with long polishing times and low polishing efficiency. The Al2O3 content in Comparative Example 6 exceeds the scope of this invention, and unmelted material (such as...) appears in the substrate glass during the melting process. Figure 4a (As shown). The MgO content in Comparative Example 7 exceeded the scope of this invention, and the spinel microcrystalline glass obtained after crystallization treatment of the substrate glass was devitrified (e.g. Figure 4b (As shown). The SiO2 content in Comparative Example 8 exceeded the scope of this invention and did not contain B2O3. The substrate glass showed delamination after melting and annealing (e.g. Figure 4c (As shown). The Na2O content in Comparative Example 9 exceeds the scope of this invention, and B2O3 is also not within the scope of this invention. Crystallization occurred in the substrate glass after melting (e.g. Figure 4d As shown), the transmittance decreased. The Li₂O content in Comparative Example 10 exceeded the scope of this invention, as did the MgO content, and it did not contain B₂O₃. After crystallization treatment, impurity phases appeared in the spinel microcrystalline glass obtained from the substrate glass, resulting in a decrease in transmittance (as shown). Figure 4e (As shown). The ZrO2 content in Comparative Example 11 exceeded the scope of the present invention, and a white precipitate appeared in the substrate glass during the melting process. Comparative Examples 6, 8, 9, and 11 failed to obtain substrate glasses with good transparency, and Comparative Examples 7 and 10 failed to obtain spinel microcrystalline glass with excellent transparency. Therefore, Comparative Examples 6 to 11 were not polished.

[0191] like Figure 2 The figure shows the XRD diffraction pattern of the spinel glass-ceramic in Example 1. It can be seen from the figure that the main crystalline phase of the glass-ceramic is (Zn,Mg)Al2O4 and the secondary crystalline phase is ZrO2.

[0192] like Figure 3 As shown, the transmittance of the spinel microcrystalline glass in Example 1 is under different wavelength conditions. Its transmittance for light with a wavelength of 550nm is greater than 90%, indicating that it has good transmittance and excellent transparency.

[0193] Referring to Table 3, chemically strengthened spinel glass-ceramics from some of the above embodiments and comparative examples were subjected to chemical strengthening treatment to obtain chemically strengthened glass-ceramics. Compared to comparative examples 12 to 16, the chemically strengthened glass-ceramics of Examples 6 to 10 still exhibit excellent high-temperature and high-humidity resistance, indicating that the chemically strengthened glass-ceramics of Examples 6 to 10 have excellent weather resistance. This demonstrates that the present invention can significantly reduce the polishing difficulty of spinel glass-ceramics while ensuring the excellent weather resistance of the obtained chemically strengthened glass-ceramics.

[0194] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0195] The various embodiments in this specification are described in a related manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0196] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A spinel microcrystalline glass, characterized in that, The spinel glass-ceramic comprises a spinel as the main crystalline phase; expressed as a molar percentage of oxides, the composition of the spinel glass-ceramic includes: SiO2 35.00mol%~48.00mol%, Al2O3 22.00mol%~30.00mol%, ZrO2 3.00mol%~4.00mol%, MgO 4.00mol%~7.00mol%, ZnO 8.00mol%~11.00mol%, Na2O 2.00mol%~12.00mol%, K2O0.00mol%~0.50mol%, Li2O 0.00mol%~4.00mol%, B2O3 3.00mol%~10.00mol%, Y2O3 0.00mol%~1.00mol%, BaO 0.00mol%~2.00mol%; The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: X=(5.23B2O3+1.52Na2O+1.33Li2O) / (100%-ZrO2-2MgO-2ZnO), 0.460≤X≤1.

000.

2. The spinel microcrystalline glass according to claim 1, wherein, The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: X=(5.23B2O3+1.52Na2O+1.33Li2O) / (100%-ZrO2-2MgO-2ZnO), 0.460≤X≤0.

900.

3. The spinel microcrystalline glass according to claim 1 or 2, wherein, The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: Y = Al₂O₃ / (MgO + ZnO), 1.000 ≤ Y ≤ 2.000; and / or, Z=(Na2O+K2O+Li2O+B2O3) / (SiO2+Al2O3), 0.100≤Z≤0.

500.

4. The spinel microcrystalline glass according to claim 3, wherein, The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: 1.600≤Y≤1.800; and / or, 0.150≤Z≤0.300。 5. The spinel microcrystalline glass according to claim 1 or 2, wherein, The spinel is (Zn,Mg)Al2O4; and / or, the spinel microcrystalline glass includes the secondary crystalline phase tetragonal ZrO2.

6. The spinel microcrystalline glass according to claim 3, wherein, The spinel is (Zn,Mg)Al2O4; and / or, the spinel microcrystalline glass includes the secondary crystalline phase tetragonal ZrO2.

7. The spinel microcrystalline glass according to claim 1 or 2, wherein, The spinel microcrystalline glass has an average grain size of 3.00 nm to 25.00 nm.

8. The spinel microcrystalline glass according to claim 7, wherein, The spinel microcrystalline glass has an average grain size of 3.00 nm to 8.00 nm.

9. The spinel microcrystalline glass according to claim 3, wherein, The spinel microcrystalline glass has an average grain size of 3.00 nm to 25.00 nm.

10. The spinel microcrystalline glass according to claim 5, wherein, The spinel microcrystalline glass has an average grain size of 3.00 nm to 25.00 nm.

11. The spinel microcrystalline glass according to claim 1 or 2, wherein, The spinel microcrystalline glass has a crystallinity of 10.00wt%~50.00wt%.

12. The spinel microcrystalline glass according to claim 11, wherein, The spinel microcrystalline glass has a crystallinity of 30.00wt%~50.00wt%.

13. The spinel microcrystalline glass according to claim 3, wherein, The spinel microcrystalline glass has a crystallinity of 10.00wt%~50.00wt%.

14. The spinel microcrystalline glass according to claim 5, wherein, The spinel microcrystalline glass has a crystallinity of 10.00wt%~50.00wt%.

15. The spinel microcrystalline glass according to claim 7, wherein, The spinel microcrystalline glass has a crystallinity of 10.00wt%~50.00wt%.

16. The spinel microcrystalline glass according to claim 1 or 2, wherein, The spinel microcrystalline glass does not contain TiO2.

17. The spinel microcrystalline glass according to claim 3, wherein, The spinel microcrystalline glass does not contain TiO2.

18. The spinel microcrystalline glass according to claim 1, wherein, The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: Z=(Na2O+K2O+Li2O+B2O3) / (SiO2+Al2O3), 0.190≤Z≤0.

300.

19. The spinel glass-ceramic according to claim 1, wherein, The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: X=(5.23B2O3+1.52Na2O+1.33Li2O) / (100%-ZrO2-2MgO-2ZnO), 0.477≤X≤0.

800.

20. The spinel microcrystalline glass according to claim 1, wherein, The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: Y=Al2O3 / (MgO+ZnO), 1.736≤Y≤1.

800.

21. The spinel microcrystalline glass according to claim 1 or 2, wherein, The spinel microcrystalline glass is transparent in the visible light range.

22. The spinel microcrystalline glass according to claim 1 or 2, wherein, At a thickness of 0.7 mm, the transmittance of the spinel microcrystalline glass for light at a wavelength of 550 nm is greater than or equal to 85.00%; and / or, At a thickness of 0.7 mm, the optical b-value of the spinel microcrystalline glass is 0.20 to 1.

50.

23. The spinel microcrystalline glass according to claim 22, wherein, At a thickness of 0.7 mm, the transmittance of the spinel microcrystalline glass for light at a wavelength of 550 nm is 85.00%~95.00%; and / or, At a thickness of 0.7 mm, the optical b-value of the spinel microcrystalline glass is 0.20 to 1.

20.

24. The spinel microcrystalline glass according to claim 22, wherein, At a thickness of 0.7 mm, the transmittance of the spinel microcrystalline glass for light at a wavelength of 550 nm is 88.00%~95.00%; and / or, At a thickness of 0.7 mm, the optical b-value of the spinel microcrystalline glass is 0.20 to 1.

00.

25. The spinel microcrystalline glass according to claim 1 or 2, wherein, The Young's modulus of the spinel microcrystalline glass is 100 GPa to 150 GPa.

26. The spinel microcrystalline glass according to claim 25, wherein, The Young's modulus of the spinel microcrystalline glass is 110 GPa to 150 GPa.

27. The spinel microcrystalline glass according to claim 1 or 2, wherein, The spinel microcrystalline glass has a Vickers hardness of 700 kgf / mm². 2 ~800kgf / mm 2 .

28. The spinel microcrystalline glass according to claim 27, wherein, The spinel microcrystalline glass has a Vickers hardness of 700 kgf / mm². 2 ~750kgf / mm 2 .

29. The spinel microcrystalline glass according to claim 1 or 2, wherein, In the spinel microcrystalline glass The molar percentage of SiO2 is 38.50 mol%~44.00 mol%; and / or, The molar percentage of Al2O3 is 24.00 mol%~27.50 mol%; and / or, The molar percentage of ZrO2 is 3.00 mol%~3.50 mol%; and / or, The molar percentage of MgO is 5.00 mol% to 6.00 mol%; and / or, The molar percentage of ZnO is 8.00 mol% to 10.00 mol%; and / or, The molar percentage of Na₂O is 3.00 mol% to 10.00 mol%; and / or, The molar percentage of B2O3 is 3.50 mol% to 9.00 mol%.

30. The spinel microcrystalline glass according to claim 3, wherein, In the spinel microcrystalline glass The molar percentage of SiO2 is 38.50 mol%~44.00 mol%; and / or, The molar percentage of Al2O3 is 24.00 mol%~27.50 mol%; and / or, The molar percentage of ZrO2 is 3.00 mol%~3.50 mol%; and / or, The molar percentage of MgO is 5.00 mol% to 6.00 mol%; and / or, The molar percentage of ZnO is 8.00 mol% to 10.00 mol%; and / or, The molar percentage of Na₂O is 3.00 mol% to 10.00 mol%; and / or, The molar percentage of B2O3 is 3.50 mol% to 9.00 mol%.

31. The spinel microcrystalline glass according to claim 1 or 2, wherein, When a polishing machine is used to polish the spinel microcrystalline glass with a main surface size of 50mm×50mm and the amount of material removed is 0.08mm, and the polishing liquid added to the polishing machine is a polishing liquid with a pH of 9.0~10.0, the polishing time is less than 640min.

32. The spinel microcrystalline glass according to claim 31, wherein, When a polishing machine is used to polish the spinel microcrystalline glass with a main surface size of 50mm×50mm and the amount of material removed is 0.08mm, and the polishing liquid added to the polishing machine is a polishing liquid with a pH of 9.0~10.0, the polishing time is less than 480min.

33. The spinel microcrystalline glass according to claim 31, wherein, When a polishing machine is used to polish the spinel microcrystalline glass with a main surface size of 50mm×50mm and the amount of material removed is 0.08mm, and the polishing liquid added to the polishing machine is a polishing liquid with a pH of 9.0~10.0, the polishing time is less than 400min.

34. A method for preparing spinel glass-ceramics as described in any one of claims 1-33, characterized in that, Includes the following steps: The substrate glass is heat-treated to form easily machinable spinel microcrystalline glass; The spinel microcrystalline glass contains spinel as the main crystalline phase; expressed as a molar percentage of oxides, the composition of the spinel microcrystalline glass includes: SiO2 35.00mol%~48.00mol%, Al2O3 22.00mol%~30.00mol%, ZrO2 3.00mol%~4.00mol%, MgO 4.00mol%~7.00mol%, ZnO 8.00mol%~11.00mol%, Na2O 2.00mol%~12.00mol%, K2O 0.00mol%~0.50mol%, Li2O 0.00mol%~4.00mol%, B2O3 3.00mol%~10.00mol%, Y2O3 0.00mol%~1.00mol%, BaO 0.00mol%~2.00mol%. The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: X=(5.23B2O3+1.52Na2O+1.33Li2O) / (100%-ZrO2-2MgO-2ZnO), 0.460≤X≤1.

000.

35. The method for preparing spinel glass-ceramics according to claim 34, wherein, The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: X = (5.23B₂O₃ + 1.52Na₂O + 1.33Li₂O) / (100% - ZrO₂ - 2MgO - 2ZnO), 0.460 ≤ X ≤ 0.900; and / or, Y = Al₂O₃ / (MgO + ZnO), 1.000 ≤ Y ≤ 2.000; and / or, Z=(Na2O+K2O+Li2O+B2O3) / (SiO2+Al2O3), 0.100≤Z≤0.

500.

36. The method for preparing spinel glass-ceramics according to claim 35, wherein, The composition of the spinel glass-ceramic, based on the molar percentage of oxides, satisfies the following: 1.600≤Y≤1.800; and / or, 0.150≤Z≤0.300。 37. The method for preparing spinel glass-ceramics according to claim 34 or 35, wherein, The spinel is (Zn,Mg)Al₂O₄; and / or, the spinel microcrystalline glass includes the secondary crystalline phase tetragonal ZrO₂; and / or In the spinel glass-ceramic, the average grain size is 3.00 nm to 25.00 nm; and / or, The spinel microcrystalline glass has a crystallinity of 10.00wt%~50.00wt%; and / or, The spinel microcrystalline glass does not contain TiO2; and / or The spinel microcrystalline glass is transparent in the visible light range.

38. The method for preparing spinel glass-ceramics according to claim 37, wherein, In the spinel glass-ceramic, the average grain size is 3.00 nm to 8.00 nm; and / or, The spinel microcrystalline glass has a crystallinity of 30.00wt%~50.00wt%.

39. The method for preparing spinel glass-ceramics according to claim 34 or 35, wherein, The heat treatment includes nucleation and crystallization; the nucleation temperature is 650℃~850℃, and the nucleation time is 0h~72h; the crystallization temperature is 700℃~1000℃, and the crystallization time is 0.1h~72h; and / or, the heating rate during the heat treatment process is controlled to be 5K / min~30K / min.

40. The method for preparing spinel glass-ceramics according to claim 39, wherein, The nucleation treatment temperature is 650℃~750℃, and the nucleation treatment time is 0h~24h; the crystallization treatment temperature is 700℃~850℃, and the crystallization treatment time is 0.1h~24h; and / or, the heating rate during the heat treatment process is controlled to be 5K / min~15K / min.

41. A chemically strengthened glass-ceramic, which is obtained by chemical strengthening treatment of the spinel glass-ceramic according to any one of claims 1-33, or by chemical strengthening treatment of the spinel glass-ceramic prepared by the preparation method according to any one of claims 34-40.

42. The chemically strengthened glass-ceramic according to claim 41, wherein, Under conditions of 85°C and 85% relative humidity, the chemically strengthened glass-ceramic is subjected to a high-temperature and high-humidity failure test, and its high-temperature and high-humidity failure time is ≥360h. The high-temperature and high-humidity failure time is the total time from the start of the high-temperature and high-humidity test to the appearance of spots or fog that cannot be wiped off in the chemically strengthened glass-ceramic.

43. A glass device made of spinel microcrystalline glass according to any one of claims 1-33, or spinel microcrystalline glass prepared by any one of claims 34-40, or chemically strengthened microcrystalline glass according to claims 41 or 42.

44. An electronic device comprising the spinel microcrystalline glass according to any one of claims 1-33, or the spinel microcrystalline glass prepared by any one of claims 34-40, or the chemically strengthened microcrystalline glass according to claims 41 or 42.

45. A substrate glass for preparing spinel microcrystalline glass as described in any one of claims 1-33, characterized in that, The composition of the substrate glass, expressed as a molar percentage of oxides, comprises: SiO2 35.00mol%~48.00mol%, Al2O3 22.00mol%~30.00mol%, ZrO2 3.00mol%~4.00mol%, MgO 4.00mol%~7.00mol%, ZnO 8.00mol%~11.00mol%, Na2O 2.00mol%~12.00mol%, K2O0.00mol%~0.50mol%, Li2O 0.00mol%~4.00mol%, B2O3 3.00mol%~10.00mol%, Y2O3 0.00mol%~1.00mol%, BaO 0.00mol%~2.00mol%; Wherein, the composition of the substrate glass, based on the molar percentage of oxides, satisfies: X=(5.23B2O3+1.52Na2O+1.33Li2O) / (100%-ZrO2-2MgO-2ZnO), 0.460≤X≤1.

000.

46. ​​The substrate glass according to claim 45, wherein, The composition of the substrate glass, based on the molar percentage of oxides, satisfies the following: X = (5.23B₂O₃ + 1.52Na₂O + 1.33Li₂O) / (100% - ZrO₂ - 2MgO - 2ZnO), 0.460 ≤ X ≤ 0.900; and / or, Y = Al₂O₃ / (MgO + ZnO), 1.000 ≤ Y ≤ 2.000; and / or, Z = (Na₂O + K₂O + Li₂O + B₂O₃) / (SiO₂ + Al₂O₃), 0.100 ≤ Z ≤ 0.500; and / or, The substrate glass does not contain TiO2.

47. The substrate glass according to claim 46, wherein, The composition of the substrate glass, based on the molar percentage of oxides, satisfies the following: 1.600≤Y≤1.800; and / or, 0.150≤Z≤0.300。

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