Transparent spinel glass-ceramics and methods of making and using the same

Abstract

The application discloses a transparent spinel glass ceramic, which comprises, in terms of molar percentage of oxides, Li2O: 3.50-6.00 mol%, Na2O: 2.00-4.00 mol%; the crystal phase of the glass ceramic contains spinel crystals and zirconium oxide crystals, and does not contain Li-containing crystals. The components of the spinel glass ceramic material are optimized, more Li ions and Na ions for chemical strengthening ion exchange are introduced into the spinel glass ceramic, the spinel glass ceramic without impurity crystal phase is obtained, the glass ceramic does not appear fogging and devitrification and the like, and excellent transmittance of the glass ceramic material is ensured. By introducing more Li ions and Na ions into the components of the spinel glass ceramic, the prepared spinel glass ceramic can be chemically strengthened, the transparent strengthened glass ceramic with high CS, DOL_0, CT_AV and CT_LD is obtained, and the strengthened glass ceramic exhibits excellent drop resistance.

Description

Technical Field

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

[0002] As electronic devices become increasingly thinner and lighter, the performance requirements for cover glass are rising. Glass-ceramics (glass-ceramics) have gained widespread attention due to their excellent impact resistance, scratch resistance, and wear resistance. Transparent spinel ceramics not only possess the high-temperature resistance, corrosion resistance, wear resistance, impact resistance, high hardness, and excellent insulation properties of general advanced ceramics, but also exhibit optical properties similar to sapphire single crystals, with good optical transmittance in the ultraviolet, visible, and infrared light bands. They are commonly used as transparent armor, missile windows, fairings, various substrate materials, new lighting fixtures, and observation windows for equipment operating under high temperature, high pressure, and corrosive environments. However, spinel microcrystalline glass generally cannot be chemically strengthened or toughened, resulting in poor toughness and drop resistance, especially at thinner thicknesses (≤1mm), where brittleness is more pronounced, making it unsuitable as electronic cover glass requiring high impact resistance.

[0003] For electronic cover glass, high CS, DOL_0, CT_AV, and CT_LD are required, especially high CT_LD, to achieve good drop resistance. To obtain high CS, DOL_0, CT_AV, and CT_LD, a certain amount of Li₂O and Na₂O needs to be added to the glass composition. However, as the amount of Li₂O and Na₂O added to the spinel glass-ceramic composition increases, crystals that affect the optical properties of the glass-ceramic often precipitate, such as β-quartz, β-quartz solid solution, and β-spodumene. The precipitation of these crystals easily causes the glass-ceramic to fog up or even become devitrified, making it difficult to obtain ideal transparent spinel glass-ceramics.

[0004] A novel transparent spinel glass-ceramic has been developed, which, while maintaining excellent optical properties, contains more Li and Na ions for chemical strengthening ion exchange. Furthermore, this transparent spinel glass-ceramic can be used to prepare reinforced glass-ceramics with high CS, DOL_0, CT_AV, and CT_LD, achieving excellent drop resistance. This is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a transparent spinel glass-ceramic. This spinel glass-ceramic contains a large number of Li and Na ions for chemical strengthening ion exchange, and does not contain impurity crystalline phases that would affect the transmittance of the glass-ceramic, thus exhibiting excellent transmittance. Using this transparent spinel glass-ceramic, transparent strengthened glass-ceramics with high CS, DOL_0, CT_AV, and CT_LD can be prepared through strengthening processes. The resulting transparent strengthened glass-ceramics exhibit excellent drop resistance. Furthermore, this invention also provides a method for preparing this transparent spinel glass-ceramic and its applications.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This invention provides a transparent spinel glass-ceramic, wherein, based on the molar percentage of oxides, the glass-ceramic comprises:

[0008] Li₂O: 3.50–6.00 mol%

[0009] Na₂O: 2.00–4.00 mol%;

[0010] The glass-ceramic crystal phase contains spinel crystals and zirconium oxide crystals, but does not contain Li-containing crystals.

[0011] The crystalline phase of the glass-ceramic does not contain quartz or quartz solid solution.

[0012] The glass-ceramic exhibits a crystallinity of at least 30.00 wt%.

[0013] The average crystal size in the glass-ceramic is less than or equal to 15.00 nm.

[0014] The spinel crystals include zinc spinel and magnesium spinel.

[0015] Specifically, at a thickness of 0.70 mm, the glass-ceramic exhibits a transmittance of greater than 85.00% at a wavelength of 550.00 nm.

[0016] The glass-ceramic further comprises, by molar percentage of oxides:

[0017] SiO2: 50.00~65.00 mol%,

[0018] Al2O3: 14.50~25.00mol%,

[0019] MgO: 3.50–8.00 mol%

[0020] ZnO: 8.00~16.00mol%

[0021] BaO: 0–2.00 mol%

[0022] TiO2+ZrO2: 3.00~5.50mol%.

[0023] In the glass-ceramic, the percentage of oxides is as follows:

[0024] 0.40≤(Al2O3+ZnO+MgO+ZrO2+TiO2) / (Li2O+Na2O+SiO2+BaO)≤0.70.

[0025] In the glass-ceramic, the percentage of oxides is as follows:

[0026] 0.43≤(Al2O3+ZnO+MgO+ZrO2+TiO2) / (Li2O+Na2O+SiO2+BaO)≤0.68.

[0027] In the glass-ceramic, the percentage of oxides is as follows:

[0028] Na2O / (Li2O+Na2O+SiO2+BaO)≥0.035;

[0029] and / or

[0030] Li2O / (Li2O+Na2O+SiO2+BaO)≥0.054.

[0031] In the glass-ceramic, the percentage of oxides is as follows:

[0032] 0.035≤Na2O / (Li2O+Na2O+SiO2+BaO)≤0.070;

[0033] and / or

[0034] 0.054≤Li2O / (Li2O+Na2O+SiO2+BaO)≤0.090.

[0035] The glass-ceramic comprises, by molar percentage of oxides, the following:

[0036] SiO2: 50.00–63.00 mol%, preferably 50.00–57.00 mol%; and / or

[0037] Al2O3: 14.50–20.00 mol%, preferably 15.00–19.00 mol%; and / or

[0038] MgO: 3.90–7.60 mol%, preferably 4.00–7.50 mol%; and / or

[0039] ZnO: 8.00–15.50 mol%, preferably 9.00–15.20 mol%; and / or

[0040] BaO: 0–1.50 mol%, preferably 1.00–1.35 mol%; and / or

[0041] Li₂O: 3.50–5.00 mol%, preferably 4.00–5.00 mol%; and / or

[0042] Na₂O: 2.30–3.60 mol%, preferably 3.00–3.60 mol%; and / or

[0043] TiO2: 0–2.00 mol%, preferably 0.30–1.30 mol%; and / or

[0044] ZrO2: 2.50–5.00 mol%, preferably 2.90–4.20 mol%.

[0045] This invention also provides a method for preparing transparent spinel glass-ceramics, comprising the following steps:

[0046] (1) Mix the ingredients according to the formula to prepare the glass precursor;

[0047] (2) The obtained glass precursor is subjected to nucleation and crystallization treatments in sequence to prepare the transparent spinel glass ceramic.

[0048] In step (2):

[0049] During nucleation, the nucleation temperature is 700–800℃ and the nucleation time is 30–1440 min.

[0050] When performing crystallization treatment, the crystallization temperature is 900-1000℃ and the crystallization time is 5-1440 min.

[0051] In step (2), during the crystallization process, the temperature is increased to the crystallization temperature at a rate greater than 20°C / min.

[0052] In step (2), during the crystallization process, the temperature is increased to the crystallization temperature at a rate greater than or equal to 25°C / min, preferably at a rate greater than or equal to 30°C / min.

[0053] In step (2), during the nucleation process, the temperature is increased to the nucleation temperature at a rate of 5 to 20 °C / min.

[0054] In step (2), the nucleation process is carried out by heating at a rate of 10°C / min to the nucleation temperature.

[0055] The present invention also provides a reinforced glass-ceramic, which is obtained by chemical strengthening ion exchange of the above-mentioned transparent spinel glass-ceramic; the reinforced glass-ceramic has a compressive stress region extending from its surface to the compression depth. Specifically:

[0056] The reinforced glass-ceramic can be prepared by performing one or more ion exchange steps in a salt bath on the above-mentioned transparent spinel glass-ceramic.

[0057] When performing a one-step ion exchange, the salt bath composition includes: 50-100 wt% NaNO3 + 0-50 wt% KNO3, the ion exchange temperature is 400-500℃, and the ion exchange time is 0.5-48 h.

[0058] When performing a two-step ion exchange, the first step involves a salt bath composition of 90–100 wt% NaNO3 + 0–10 wt% KNO3, an ion exchange temperature of 400–500 °C, and an ion exchange time of 0.5–48 h.

[0059] The second step involves a salt bath consisting of 0–10 wt% NaNO3 and 90–100 wt% KNO3. The ion exchange temperature is 400–500℃, and the ion exchange time is 0.5–48 h.

[0060] To improve the service life of a salt bath, a salt bath protectant comprising 0.1–5.0 wt% of the salt bath's mass can be added. This salt bath protectant includes agents for passivating, precipitating, or absorbing Li. + The substance.

[0061] Wherein, the compressive stress layer depth DOL_0 of the reinforced glass ceramic is greater than or equal to 14% of the thickness of the reinforced glass ceramic, and the tensile stress linear density CT_LD of the reinforced glass ceramic is greater than or equal to 25000MPa / mm.

[0062] The tensile stress linear density CT_LD of the reinforced glass ceramic is 25000-40000 MPa / mm, preferably 27000-40000 MPa / mm.

[0063] The surface compressive stress CS of the reinforced glass ceramic is greater than or equal to 650 MPa, preferably greater than or equal to 680 MPa.

[0064] The average tensile stress CT_AV of the reinforced glass ceramic is greater than or equal to 35.0 MPa, preferably greater than or equal to 39.0 MPa.

[0065] The Vickers hardness of the reinforced glass ceramic is greater than or equal to 740HV0.3.

[0066] Wherein, the fracture toughness of the reinforced glass-ceramic is greater than or equal to 1.500 MPa·m. 1 / 2 Preferably, it is greater than or equal to 1.560 MPa·m 1 / 2

[0067] The present invention also provides an electronic terminal as a consumer product, comprising:

[0068] The housing includes a front surface, a rear surface, and side surfaces;

[0069] And some electronic components located within the housing, the electronic components including a display device located on or adjacent to the front surface of the housing;

[0070] The front surface and / or rear surface and / or side surface comprise the reinforced glass-ceramic material described above;

[0071] It also includes a cover article covering the front surface of the housing or located on the display device, the cover article comprising the aforementioned reinforced glass-ceramic material;

[0072] The electronic terminals mentioned as consumer products include mobile phones, tablet computers, photovoltaic devices, or other electronic terminals (such as electronic watches).

[0073] The transparent spinel glass-ceramic material and the reinforced glass-ceramic material in this invention have excellent properties and can be included / applied in other products, such as watches, transparent armor, missile windows, fairings, substrate materials, new lamps, observation windows of equipment in high temperature, high pressure and corrosive environments, display protection materials and outer shell protection materials for portable smart electronic devices (portable smart electronic devices include mobile phones, tablets, electronic watches, etc.), building products, transportation products (e.g., automobiles, trains, airplanes, marine vehicles, etc.), appliances, or any product that requires a certain degree of transparency, scratch resistance, impact resistance, wear resistance or a combination thereof.

[0074] Compared with the prior art, the present invention has the following beneficial effects:

[0075] 1. This invention optimizes the composition of spinel glass-ceramic materials by introducing more Li and Na ions for chemical strengthening ion exchange into the spinel glass-ceramic, thereby obtaining spinel glass-ceramic without impurity crystal phases (such as impurity crystal phases containing Li crystal phase, quartz, quartz solid solution, etc.). The glass-ceramic does not exhibit phenomena such as fogging and devitrification, ensuring that the glass-ceramic material has excellent transmittance.

[0076] By introducing more Li and Na ions into the spinel glass-ceramic composition, the resulting spinel glass-ceramic can be chemically strengthened, resulting in a transparent strengthened glass-ceramic with high CS, DOL_0, CT_AV, and CT_LD, which exhibits excellent drop resistance.

[0077] 2. After performance testing of the glass-ceramic material prepared by the present invention, it was found that the transparent spinel glass-ceramic material of the present invention has a high degree of crystallinity, which brings excellent mechanical properties to the glass-ceramic material.

[0078] 3. The present invention also provides a method for preparing spinel glass ceramics. The process method provided by the present invention controls the process parameters of the crystallization process and the nucleation process, and sets the heating rate parameter requirements, and finally obtains spinel glass ceramics without impurity crystal phases (such as impurity crystal phases containing Li crystal phase, quartz, quartz solid solution and other impurity crystal phases), ensuring that the glass ceramic material has excellent optical properties. Attached Figure Description

[0079] Figure 1 This is a diagram showing the effect of a drop test on the entire machine.

[0080] Figure 2 The relationship between Li2O content and CT_LD is given, where D represents the comparative example and S represents the specific example.

[0081] Figure 3 These are DSC spectra of glass precursors with different Li contents.

[0082] Figure 4 XRD patterns of glass-ceramics prepared by different heating rates during crystallization treatment.

[0083] Figure 5 Photographs of glass-ceramics prepared using different heating rates during crystallization treatment, including:

[0084] (a) is glass that has not undergone heat treatment;

[0085] (b) Glass ceramics prepared by a heating rate of 5℃ / min during crystallization treatment;

[0086] (c) Glass ceramics prepared by a heating rate of 20℃ / min during crystallization treatment;

[0087] (d) is a glass-ceramic obtained by using a heating rate of 30℃ / min during crystallization treatment.

[0088] Figure 6 This diagram illustrates the transmittance of glass ceramics prepared at different heating rates to 550nm wavelength light during crystallization. Detailed Implementation

[0089] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings.

[0090] I. The relevant proprietary names and related measurement methods involved in this invention are explained as follows:

[0091] Glass ceramics: also known as microcrystalline glass, are a type of solid composite material that contains both glass phase and microcrystalline phase, prepared by targeted and controlled crystallization of a base glass.

[0092] Strengthened glass-ceramics are solid composite materials obtained by chemically strengthening glass-ceramics. During high-temperature chemical strengthening, alkali metal ions with large ionic radii (such as potassium and sodium ions) in the salt bath replace alkali metal ions with small ionic radii (such as sodium and lithium ions) in the glass-ceramics, thereby creating a volume difference in exchange ions and generating compressive stress on the surface of the glass-ceramics.

[0093] Surface compressive stress (CS): After chemical strengthening, the alkali metal ions with smaller surface radii are replaced by alkali metal ions with larger radii. Due to the crowding effect of the larger alkali metal ions, compressive stress is generated on the glass surface, which is called surface compressive stress.

[0094] The compressive stress layer depth DOL_0 refers to the distance from the surface of the reinforced glass ceramic to the location where the compressive stress is zero.

[0095] Tensile stress linear density (CT_LD): The ratio of the sum of tensile stresses obtained from testing with an SLP stress meter to the thickness of the glass-ceramic. After chemical strengthening, a tensile stress layer is formed inside the strengthened glass-ceramic. The tensile stress layer has an upper boundary at a certain distance from the upper surface of the strengthened glass-ceramic and a lower boundary at a certain distance from the lower surface of the strengthened glass-ceramic. The curve plotted with the tensile stress at a point on a line segment within the tensile stress layer that is perpendicular to both the upper and lower boundaries, with its upper and lower endpoints falling on the upper and lower boundaries respectively, is called the tensile stress curve. The ratio of the definite integral of the tensile stress curve to the thickness of the strengthened glass-ceramic is called the tensile stress linear density, which is also the ratio of the sum of tensile stresses of the strengthened glass-ceramic measured by the SLP-2000 stress meter to the thickness of the glass.

[0096] In chemically strengthened glass, compressive stress and tensile stress are in equilibrium and equal relationship. The SLP-2000 stress meter is more accurate in testing the tensile stress area of ​​glass. Therefore, the ratio of tensile stress integral to thickness is used to characterize the stress contained in glass ceramics per unit thickness, which is used to characterize the stress level of chemically strengthened glass ceramics.

[0097] CT_AV: refers to the average value of all tensile stresses in the tensile stress zone.

[0098] Nucleation temperature: The temperature at which crystal nuclei form.

[0099] Crystallization temperature: The temperature at which the growth rate of the target crystal can be controlled.

[0100] Transmittance: When light of a certain wavelength shines on a glass surface, it will be reflected, absorbed, and transmitted. The ratio of the intensity of the transmitted portion to the intensity of the incident light is called transmittance.

[0101] Fogging: Due to the large size or phase separation of crystals in glass and ceramics, it appears as a semi-transparent state, which is between transparent and devitrified.

[0102] De-opaqueness: Due to the large size or phase separation of crystals in the glass ceramic, the transparent properties of glass are completely lost, and it is impossible to see any image on the back through the glass.

[0103] Differential scanning calorimetry (DSC) testing:

[0104] After grinding the sample into powder, it was passed through a 200-mesh sieve.

[0105] The test conditions were: room temperature to 1100℃, heating rate of 10℃ / min;

[0106] The testing instrument was a Mettler Toledo TGA / DSC3+ thermogravimetric and simultaneous thermal analyzer.

[0107] Transmittance test:

[0108] The crystallized glass slides are first cleaned in an ultrasonic cleaner. The cleaning conditions include:

[0109] Cleaning time: 5-10 minutes;

[0110] Cleaning agent used: Common detergent diluted 10 times;

[0111] Cleaning temperature: 45℃-65℃;

[0112] Cleaning frequency: 20kHz-40kHz.

[0113] Then, the transmittance of the glass at different wavelengths was tested using a haze meter, and the test was carried out in accordance with the standard GB / T 7962.12-2010 Colorless Optical Glass Test Methods Part 12: Spectral Transmittance.

[0114] The haze meter used in this invention is a Konica Minolta CM-3600A spectrophotometer.

[0115] Whole machine drop test:

[0116] First, attach 120-grit sandpaper to a 160g Huawei P30 model, and place a 50*50*0.7mm reinforced glass ceramic sheet to be tested directly below the model. Then, drop the model from a specified height in an impact manner.

[0117] Each batch of samples must contain at least 10 pieces. The drop height starts from 0.4m. The sample is subjected to a drop impact. If it does not break, the height is increased by 0.1m each time and the sample is dropped again until the glass breaks. The average of the two break heights is taken as the drop resistance height.

[0118] In this invention, stress measurements can be performed using the FSM6000 and SLP2000 instruments manufactured by Orihara to measure the surface high-pressure stress zone and the deep low-pressure stress zone, respectively. The stress curves are then fitted using PMC software to obtain the corresponding test results. Alternatively, other stress testing instruments capable of measuring both the surface high-pressure stress zone and the deep low-pressure stress zone can also be used.

[0119] II. This invention provides a transparent spinel glass-ceramic, wherein, based on the molar percentage of oxides, the glass-ceramic comprises:

[0120] Li₂O: 3.50–6.00 mol%

[0121] Na₂O: 2.00–4.00 mol%;

[0122] The glass-ceramic crystal phase contains spinel crystals and zirconium oxide crystals, but does not contain Li-containing crystals.

[0123] This invention focuses on the composition of glass-ceramic materials. To achieve toughening through chemical strengthening and obtain high CS, DOL_0, CT_AV, and CT_LD, thus improving impact and drop resistance, it is necessary to add alkali metal oxides, especially Li₂O (lithium oxide) and Na₂O (sodium oxide). However, as the amount of Li₂O and Na₂O increases, it often leads to the precipitation of impurity crystals in the glass that affect the optical properties of the glass-ceramic, such as β-quartz, β-quartz solid solution, and β-spodumene. (Appendix) Figure 3 This is well confirmed; as the Li₂O content increases, the attached... Figure 3 The single peak formed by spinel gradually transforms into a multi-peak structure (spinel peak + other impurity crystal phases). The precipitation of these impurity crystals can easily cause the crystallized glass to appear hazy or even devitrified, which will seriously affect the optical properties of the glass ceramic.

[0124] To address this issue, existing technologies typically reduce the amount of Li₂O and Na₂O added to avoid the precipitation of excessive crystalline phases such as β-quartz, β-quartz solid solution, and β-spodumene, thereby preventing fogging and devitrification in glass-ceramics. However, this approach inevitably leads to relatively low CS, DOL_0, CT_AV, and CT_LD values ​​obtained through glass-ceramic strengthening, making it difficult to achieve excellent drop resistance.

[0125] In order to obtain transparent reinforced spinel glass-ceramics with high CS, DOL_0, CT_AV, and CT_LD, and to improve the drop resistance of spinel glass-ceramics, the composition of this invention has been optimized.

[0126] This invention, by introducing more Li₂O and Na₂O, yields spinel glass-ceramics free of impurity crystalline phases (such as those containing Li, quartz, or quartz solid solutions). The glass-ceramics exhibit no fogging or devitrification, ensuring excellent transmittance. Furthermore, by introducing more Li and Na ions into the spinel glass-ceramic composition, the resulting spinel glass-ceramic can be chemically strengthened, yielding transparent strengthened glass-ceramics with high CS, DOL_0, CT_AV, and CT_LD, exhibiting excellent drop resistance.

[0127] In the transparent spinel glass-ceramic provided by this invention:

[0128] The Li₂O content includes all ranges and subranges from 3.50 to 6.00 mol%, such as 3.50 to 5.00 mol%, 4.50 to 5.00 mol%, 4.50 to 5.50 mol%, 3.50 to 4.50 mol%, 4.00 to 5.00 mol%, 4.50 to 6.00 mol%, 5.00 to 6.00 mol%, 5.50 to 6.00 mol%, 3.50 to 4.00 mol%, 3.50 to 4.40 mol%, 3.80 to 5.50 mol%, 3.90 to 4.00 mol%, 3.60 to 4.40 mol%, 4.80 to 5.90 mol%, etc.; in some embodiments, The Li₂O content can be 3.50 mol%, 3.60 mol%, 3.70 mol%, 3.80 mol%, 3.90 mol%, 4.00 mol%, 4.10 mol%, 4.20 mol%, 4.30 mol%, 4.40 mol%, 4.50 mol%, 4.60 mol%, 4.70 mol%, 4.80 mol%, 4.90 mol%, 5.00 mol%, 5.10 mol%, 5.20 mol%, 5.30 mol%, 5.40 mol%, 5.50 mol%, 5.60 mol%, 5.70 mol%, 5.80 mol%, 5.90 mol%, 6.00 mol%, etc.

[0129] The Na₂O content includes all ranges and subranges from 2.00 to 4.00 mol%, such as 2.30–3.60 mol%, 3.00–3.60 mol%, 2.5–3.00 mol%, 2.40–3.80 mol%, 2.00–2.60 mol%, 2.00–2.80 mol%, 2.50–3.20 mol%, 2.50–3.60 mol%, 2.50–3.10 mol%, 2.50–3.40 mol%, 2.50–3.80 mol%, 2.80–3.50 mol%, and 2.10–3.90 mol%. In some embodiments, the Na2O content may be 2.00 mol%, 2.10 mol%, 2.20 mol%, 2.30 mol%, 2.40 mol%, 2.50 mol%, 2.60 mol%, 2.70 mol%, 2.80 mol%, 2.90 mol%, 3.00 mol%, 3.10 mol%, 3.20 mol%, 3.30 mol%, 3.40 mol%, 3.50 mol%, 3.60 mol%, 3.70 mol%, 3.80 mol%, 3.90 mol%, 4.00 mol%, etc.

[0130] In some embodiments, the crystalline phase of the glass-ceramic does not contain quartz or quartz solid solution. The presence of quartz and quartz solid solution can affect the optical properties of spinel glass-ceramics, easily causing the crystallized glass to exhibit haziness or even devitrification.

[0131] In some embodiments, the glass-ceramic exhibits a crystallinity of at least 30.00 wt%; the average crystal size in the glass-ceramic is less than or equal to 15.0 nm. By controlling to obtain sufficiently high crystallinity, the intrinsic strength of the glass-ceramic can be significantly improved, while by controlling the crystal size to ensure that the crystal size is small enough, the light transmittance of the glass-ceramic can be significantly improved, ensuring that the glass-ceramic has excellent optical properties. The glass-ceramic of the present invention exhibits a crystallinity of at least 30.00 wt%, including all ranges and subranges greater than or equal to 30.00 wt%, such as 30.00–50.00 wt%, 30.00–40.00 wt%, 40.00–50.00 wt%, 35.00–40.00 wt%, 30.00–44.00 wt%, 31.00–35.00 wt%, 42.00–45.00 wt%, 31.00–37.00 wt%, 30.00–38.00 wt%, 30.00–39.00 wt%, etc.; in In some embodiments, the crystallinity of the glass-ceramic of the present invention can be 30.00 wt%, 31.00 wt%, 32.00 wt%, 33.00 wt%, 34.00 wt%, 35.00 wt%, 36.00 wt%, 37.00 wt%, 38.00 wt%, 39.00 wt%, 40.00 wt%, 41.00 wt%, 42.00 wt%, 43.00 wt%, 44.00 wt%, 45.00 wt%, 46.00 wt%, 47.00 wt%, 48.00 wt%, 49.00 wt%, 50.00 wt%, etc. Meanwhile, the average crystal size in the glass-ceramic of the present invention is less than or equal to 15.0 nm, including all ranges and sub-ranges between 15.0 nm and therebetween, such as 5.0–10.0 nm, 5.0–11.0 nm, 5.0–13.0 nm, 4.0–10.0 nm, 3.0–15.0 nm, 6.0–13.0 nm, 7.0–12.0 nm, 2.0–10.0 nm, 5.0–14.0 nm, 4.0–9.0 nm, etc. In some embodiments, the average crystal size of the glass-ceramic of the present invention may be 2.0 nm, 3.0 nm, 4.0 nm, 5.0 nm, 6.0 nm, 7.0 nm, 9.0 nm, 10.0 nm, 11.0 nm, 12.0 nm, 13.0 nm, 14.0 nm, 15.0 nm, etc.

[0132] In some embodiments, the spinel crystal comprises zinc spinel and magnesium spinel, and / or a solid solution of zinc spinel (ZnAl₂O₄) and magnesium spinel (MgAl₂O₄). Zinc spinel (ZnAl₂O₄) is a cubic mineral with a Mohs hardness of 7.5–8 and a measured density of 4.38–4.60 g / cm³. 3 Under environmental pressure, zinc spinel has a Young's modulus of 290 GPa, a shear modulus of 146 GPa, and a refractive index of 1.79-1.80. Zinc spinel (ZnAl₂O₄) forms a solid solution with magnesium spinel (MgAl₂O₄), and the properties of the solid-solution spinel are almost identical to those of zinc spinel (ZnAl₂O₄). Differences include (Mg spinel relative to zinc spinel): (a) a lower refractive index (Mg spinel: 1.72 vs. Zinc spinel: 1.79-1.80); (b) a lower density (Mg spinel: 3.6-4.1 g / cm³). 3 vs. zinc spinel: 4.4-4.6 g / cm³ 3 (c) Lower Young's modulus (magnesium spinel: 283 GPa vs. zinc spinel: 290 GPa); (d) Higher shear modulus (magnesium spinel: 155 GPa vs. zinc spinel: 146 GPa). The high hardness, high density, and high elastic constant of zinc-magnesium spinel make the mechanical properties of the composite glass-ceramic superior to those of the precursor glass, because the mechanical properties of the composite glass-ceramic are a function of the mechanical properties of each component phase. Zinc-magnesium spinel glass-ceramics exhibit excellent resistance to crack propagation and scratches.

[0133] In some embodiments, the glass-ceramic, at a thickness of 0.7 mm, exhibits a transmittance greater than 85.00% at a wavelength of 550 nm. The glass-ceramic of the present invention is transparent in the visible light range and exhibits a transmittance of at least about 85.00% at a wavelength of 550 nm. The transmittance of the glass-ceramic of the present invention at a wavelength of 550 nm greater than 85.00% includes all ranges and subranges greater than 85.00%, such as 86.00%, 87.00%, 88.00%, 89.00%, 90.00%, 91.00%, 92.00%, 93.00%, etc.

[0134] In some embodiments, the glass-ceramic of the present invention further comprises, by molar percentage of oxides, the following components:

[0135] SiO2: 50.00~65.00 mol%,

[0136] Al2O3: 14.50~25.00mol%,

[0137] MgO: 3.50–8.00 mol%

[0138] ZnO: 8.00~16.00mol%

[0139] BaO: 0–2.00 mol%

[0140] TiO2+ZrO2: 3.00~5.50mol%.

[0141] Furthermore, based on the molar percentage of oxides, the glass-ceramic of the present invention further includes the following components:

[0142] SiO2: 50.00–63.00 mol%, preferably 50.00–57.00 mol%; and / or

[0143] Al2O3: 14.50–20.00 mol%, preferably 15.00–19.00 mol%; and / or

[0144] MgO: 3.90–7.60 mol%, preferably 4.00–7.50 mol%; and / or

[0145] ZnO: 8.00–15.50 mol%, preferably 9.00–15.20 mol%; and / or

[0146] BaO: 0–1.50 mol%, preferably 1.00–1.35 mol%; and / or

[0147] Li₂O: 3.50–5.00 mol%, preferably 4.00–5.00 mol%; and / or

[0148] Na₂O: 2.30–3.60 mol%, preferably 3.00–3.60 mol%; and / or

[0149] TiO2: 0–2.00 mol%, preferably 0.30–1.30 mol%; and / or

[0150] ZrO2: 2.50–5.00 mol%, preferably 2.90–4.20 mol%.

[0151] In this invention:

[0152] SiO2 (silicon dioxide) and Al2O3 (aluminum oxide) are the main components constituting the glass network structure. Sufficient SiO2 and Al2O3 ensure high network structure strength in the glass, which is beneficial for maintaining high intrinsic strength and thermal stability. However, excessive SiO2 and Al2O3 content increases the difficulty of glass melting. Al2O3 not only provides Al element for the precipitation of spinel crystals but also increases the surface compressive stress during chemical strengthening treatment.

[0153] MgO (magnesium oxide) and ZnO (zinc oxide) provide the necessary Mg and Zn elements for the formation of spinel crystals in glass ceramics. MgO increases the high-temperature viscosity of the molten glass, reduces the tendency and rate of crystallization, and improves the chemical stability and mechanical strength of the glass. ZnO, as a network intermediate, consumes free oxygen in the glass to form [ZnO4], which enters the glass's structural network, making the glass structure more stable. However, excessive ZnO can make the glass more prone to crystallization. Therefore, adjusting the ratio of MgO to ZnO can control the crystal precipitation rate.

[0154] Barium oxide (BaO) can accelerate the melting of glass, but if the content is too high, it can easily generate secondary bubbles, making clarification difficult.

[0155] TiO2 (titanium oxide) and ZrO2 (zirconia) are used as nucleating agents. ZrO2 increases the viscosity and chemical stability of glass, but excessive content can make the glass difficult to melt. TiO2 improves the chemical stability of glass and can also increase the uniformity of glass melting, but excessive content can cause the glass to become colored and increase its refractive index. The combined use of TiO2 and ZrO2 can achieve a very good nucleation effect.

[0156] The SiO2 content includes all ranges and subranges from 50.00 to 65.00 mol%, such as 50.00 to 63.00 mol%, 50.00 to 65.00 mol%, 50.00 to 60.00 mol%, 51.00 to 63.00 mol%, 52.00 to 65.00 mol%, 53.00 to 65.00 mol%, 55.00 to 65.00 mol%, 50.00 to 57.00 mol%, and 52.00 to 57.00 mol%. In some embodiments, the SiO2 content may be 50.00 mol%, 51.00 mol%, 52.00 mol%, 53.00 mol%, 54.00 mol%, 55.00 mol%, 56.00 mol%, 57.00 mol%, 58.00 mol%, 59.00 mol%, 60.00 mol%, 61.00 mol%, 62.00 mol%, 63.00 mol%, 64.00 mol%, 65.00 mol%, etc.

[0157] The content of Al2O3 includes all ranges and subranges from 14.50 to 25.00 mol%, such as 14.50 to 20.00 mol%, 15.00 to 19.00 mol%, 14.50 to 20.00 mol%, 15.50 to 20.00 mol%, 15.00 to 24.00 mol%, 14.90 to 23.00 mol%, 16.00 to 24.00 mol%, 17.00 to 25.00 mol%, 18.00 to 25.00 mol%, etc. In some embodiments, the content of Al2O3 may be 14.50 mol%, 14.90 mol%, 15.00 mol%, 15.50 mol%, 16.00 mol%, 17.00 mol%, 18.00 mol%, 19.00 mol%, 20.00 mol%, 23.00 mol%, 24.00 mol%, 25.00 mol%, etc.

[0158] The MgO content includes all ranges and subranges from 3.50 to 8.00 mol%, such as 4.00 to 7.50 mol%, 3.90 to 7.60 mol%, 3.50 to 4.00 mol%, 3.50 to 5.00 mol%, 3.50 to 6.00 mol%, 3.50 to 7.00 mol%, 4.50 to 6.00 mol%, 5.50 to 8.00 mol%, 6.50 to 8.00 mol%, etc. In some embodiments, the MgO content may be 3.50 mol%, 3.90 mol%, 4.00 mol%, 4.50 mol%, 5.00 mol%, 5.50 mol%, 6.00 mol%, 6.50 mol%, 7.00 mol%, 7.50 mol%, 7.60 mol%, 8.00 mol%, etc.

[0159] The ZnO content includes all ranges and subranges from 8.00 to 16.00 mol%, such as 8.00 to 15.50 mol%, 9.00 to 15.20 mol%, 8.00 to 13.00 mol%, 9.00 to 16.00 mol%, 10.00 to 16.00 mol%, 8.00 to 10.00 mol%, 8.00 to 11.00 mol%, 8.00 to 12.00 mol%, 9.00 to 14.00 mol%, and 9.00 to 12.00 mol%. In some embodiments, the ZnO content may be 8.00 mol%, 9.00 mol%, 10.00 mol%, 11.00 mol%, 12.00 mol%, 13.00 mol%, 14.00 mol%, 15.20 mol%, 15.50 mol%, 16.00 mol%, etc.

[0160] The BaO content includes all ranges and subranges from 0 to 2.00 mol%, such as 0 to 1.50 mol%, 1.00 to 1.40 mol%, 0 to 1.00 mol%, 1.00 to 2.00 mol%, 1.10 to 2.00 mol%, 1.20 to 2.00 mol%, 1.10 to 1.50 mol%, 1.20 to 1.80 mol%, etc. In some embodiments, the BaO content may be 0 mol%, 1.00 mol%, 1.10 mol%, 1.20 mol%, 1.40 mol%, 1.50 mol%, 1.80 mol%, 2.00 mol%, etc.

[0161] The content of TiO2+ZrO2 includes all ranges and subranges from 3.00 to 5.50 mol%, such as 3.00–5.00 mol%, 3.50–5.00 mol%, 4.50–5.00 mol%, 3.10–4.50 mol%, 3.30–4.70 mol%, 3.70–4.50 mol%, 3.10–4.80 mol%, 4.00–5.00 mol%, 3.00–4.20 mol%, 3.20–5.10 mol%, 3.40–5.40 mol%, 3.70–5.20 mol%, and 3.00–4.00 mol%. In some embodiments, the content of TiO2+ZrO2 can be 3.00 mol%, 3.10 mol%, 3.20 mol%, 3.30 mol%, 3.40 mol%, 3.50 mol%, 3.70 mol%, 4.00 mol%, 4.20 mol%, 4.50 mol%, 4.70 mol%, 4.80 mol%, 5.00 mol%, 5.10 mol%, 5.20 mol%, 5.40 mol%, 5.50 mol%, etc.

[0162] The TiO2 content includes all ranges and subranges from 0 to 2.00 mol%, such as 0.10 to 1.00 mol%, 0.50 to 1.00 mol%, 0.20 to 1.90 mol%, 0.40 to 1.20 mol%, 0.60 to 1.50 mol%, 0.80 to 1.00 mol%, 0.30 to 1.80 mol%, 0.20 to 1.50 mol%, 0.30 to 1.30 mol%, 0.10 to 1.70 mol%, etc. In some embodiments, the TiO2 content can be 0 mol%, 0.10 mol%, 0.20 mol%, 0.30 mol%, 0.40 mol%, 0.50 mol%, 0.60 mol%, 0.80 mol%, 0.90 mol%, 1.00 mol%, 1.20 mol%, 1.30 mol%, 1.50 mol%, 1.70 mol%, 1.80 mol%, 1.90 mol%, 2.00 mol%, etc.

[0163] The ZrO2 content includes all ranges and subranges from 2.50 to 5.00 mol%, such as 2.60 to 4.50 mol%, 2.70 to 4.50 mol%, 2.90 to 4.20 mol%, 2.90 to 3.50 mol%, 2.80 to 3.70 mol%, 2.50 to 3.10 mol%, 2.60 to 4.60 mol%, 3.50 to 5.00 mol%, 4.50 to 5.00 mol%, 3.10 to 4.50 mol%, 3.20 to 4.30 mol%, 2.90 to 3.80 mol%, and 2.70 to 3.80 mol%. In some embodiments, the ZrO2 content may be 2.50 mol%, 2.60 mol%, 2.70 mol%, 2.80 mol%, 2.90 mol%, 3.10 mol%, 3.20 mol%, 3.50 mol%, 3.70 mol%, 3.80 mol%, 4.20 mol%, 4.30 mol%, 4.50 mol%, 4.60 mol%, 5.00 mol%, etc.

[0164] After the ingredients are prepared, a clarifying agent needs to be added to the mixture. The clarifying agent is not particularly limited and can be sodium chloride (NaCl), tin oxide, etc. The amount of clarifying agent should not exceed 2 wt% of the weight of the mixture. For example, if the weight of the mixture prepared according to the formula is 1 kg, then the amount of clarifying agent added should not exceed 20 g. The clarifying agent is an auxiliary component added during the preparation process.

[0165] In some embodiments, the glass-ceramic contains, by molar percentage of oxides:

[0166] 0.40 ≤ (Al₂O₃ + ZnO + MgO + ZrO₂ + TiO₂) / (Li₂O + Na₂O + SiO₂ + BaO) ≤ 0.70. In this invention, by configuring crystallizable glasses to have this specified ratio, glass-ceramics made from these crystallizable glasses can possess the properties described in this invention, including the composition and / or amount and / or structure of zinc spinel and magnesium spinel. For example, the components in the glass-ceramic can be specified to satisfy the above molar ratio, such that the glass-ceramic contains zinc spinel, magnesium spinel, and a glass phase, thereby affecting the properties and / or characteristics of the glass-ceramic made therefrom. For example, the crystallinity of the glass-ceramic can be increased, resulting in superior intrinsic strength, while also achieving higher transmittance and rapid and efficient ion exchange. By configuring the crystallizable glasses in this way, this ratio allows for practical transformation processes (e.g., nucleation and crystallization temperatures and / or times), while allowing the formation of glass-ceramics characterized by the desired superior optical properties and intrinsic strength that can be achieved repeatedly and reliably. The ratio of (Al2O3+ZnO+MgO+ZrO2+TiO2) / (Li2O+Na2O+SiO2+BaO) includes all ranges and subranges from 0.40 to 0.70, such as 0.41–0.51, 0.43–0.68, 0.42–0.60, 0.43–0.55, 0.44–0.58, 0.42–0.68, 0.45–0.69, 0.46–0.62, 0.41–0.54, 0.43–0.54, 0.44–0.59, 0.49–0.70, etc. In some embodiments, the ratio of (Al2O3+ZnO+MgO+ZrO2+TiO2) / (Li2O+Na2O+SiO2+BaO) can be 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, etc.

[0167] In some embodiments, the glass-ceramic contains, by molar percentage of oxides:

[0168] The ratio of Na₂O / (Li₂O+Na₂O+SiO₂+BaO) is ≥0.035; and / or Li₂O / (Li₂O+Na₂O+SiO₂+BaO) is ≥0.054. Further investigation into the relationship between Na₂O and Li₂O and other components revealed that controlling the amounts of Na₂O and Li₂O within this specified ratio range ensures excellent ion exchange capacity in the glass-ceramic, guaranteeing the obtained transparent spinel glass-ceramic. Through chemically enhanced ion exchange, high CS, DOL_0, CT_AV, and CT_LD can be achieved.

[0169] The ratio of Na2O / (Li2O+Na2O+SiO2+BaO) includes all ranges and subranges greater than or equal to 0.035, such as 0.035~0.070, 0.039~0.058, 0.035~0.051, 0.035~0.052, 0.035~0.055, 0.040~0.060, 0.055~0.060, 0.038~0.052, etc. In some embodiments, the ratio of Na2O / (Li2O+Na2O+SiO2+BaO) can be 0.035, 0.036, 0.037, 0.038, 0.039, 0.040, 0.043, 0.045, 0.048, 0.050, 0.051, 0.052, 0.055, 0.058, 0.060, 0.063, 0.065, 0.068, 0.070, etc.

[0170] The ratio of Li2O / (Li2O+Na2O+SiO2+BaO) includes all ranges and subranges greater than or equal to 0.054, such as 0.054~0.090, 0.055~0.080, 0.056~0.074, 0.058~0.073, 0.056~0.071, 0.059~0.077, 0.055~0.065, 0.055~0.075, etc. In some implementations, the ratio of Li2O / (Li2O+Na2O+SiO2+BaO) can be 0.054, 0.055, 0.056, 0.058, 0.059, 0.060, 0.063, 0.065, 0.068, 0.070, 0.071, 0.073, 0.074, 0.075, 0.077, 0.080, 0.083, 0.085, 0.088, 0.090, etc.

[0171] III. This invention provides a method for preparing transparent spinel glass-ceramics, comprising the following steps:

[0172] (1) Mix the ingredients according to the formula to prepare the glass precursor;

[0173] (2) The obtained glass precursor is subjected to nucleation and crystallization treatments in sequence to prepare the above-mentioned transparent spinel glass ceramic.

[0174] In this invention, the ingredients are mixed according to the above formula for 30 minutes. After thorough mixing, a clarifying agent is added as needed, and the mixture is melted in a platinum crucible at 1650°C for 20 hours. The melt is then poured into a molding die, cooled to 900°C, and annealed in a 600°C annealing furnace for 6 hours. After annealing in the furnace to room temperature, a glass precursor is obtained. The glass precursor is then subjected to nucleation and crystallization treatments to prepare a transparent spinel glass-ceramic.

[0175] To obtain the transparent spinel glass-ceramic product of this invention, the nucleation treatment is performed at a temperature of 700–800°C for 30–1440 min; the crystallization treatment is performed at a temperature of 900–1000°C for 5–1440 min. Here, the nucleation treatment time refers to the time spent holding the crystallization furnace at the set temperature after heating it to the set nucleation temperature at the set heating rate. The crystallization treatment time refers to the time spent holding the crystallization furnace at the set temperature after heating it to the set crystallization temperature at the set heating rate.

[0176] The glass precursor is placed in a crystallization furnace and heated to the nucleation temperature at a rate of 5–20 °C / min, held for 30–1440 min to perform nucleation treatment, forming a sufficient number of crystal nuclei to ensure the crystallinity of the glass ceramic. After nucleation, the temperature is increased to the crystallization temperature at a rate greater than 20 °C / min, held for 5–1440 min to perform crystallization treatment, precipitating the desired zinc spinel and magnesium spinel, while effectively suppressing the precipitation of impurity phases. After crystallization, the furnace is cooled to room temperature. By adjusting the heating rate, temperature, and time of different treatment stages to suit the glass ceramic composition within the above range, it can be ensured that impurity phases affecting the transmittance of spinel glass ceramics will not precipitate, and that fogging and devitrification will not occur in the glass ceramics.

[0177] The nucleation temperature includes all ranges and subranges between 700 and 800°C, such as 710–790°C, 700–720°C, 700–730°C, 700–740°C, 700–750°C, 700–760°C, 730–800°C, 740–800°C, 750–800°C, 760–800°C, etc. The nucleation treatment time includes all ranges and subranges from 30 to 1440 min, such as 30–300 min, 30–200 min, 30–700 min, 30–500 min, 60–120 min, 80–144 min, 90–1200 min, 100–1100 min, 300–440 min, 100–500 min, 200–600 min, 300–540 min, 100–440 min, 300–440 min, etc.

[0178] The crystallization temperature includes all ranges and sub-ranges within the range of 900–1000℃, such as 900–980℃, 900–960℃, 900–950℃, 900–930℃, 920–950℃, 910–1000℃, 920–1000℃, 930–1000℃, 940–1000℃, etc. The crystallization treatment time includes all ranges and sub-ranges within the range of 5–1440 min, such as 5–100 min, 5–150 min, 5–200 min, 50–300 min, 100–440 min, 90–340 min, 200–1240 min, 800–1040 min, 500–740 min, 900–1040 min, 200–340 min, 100–300 min, 500–1440 min, etc.

[0179] In some embodiments, the heating rate during crystallization affects the crystalline phase composition of the glass-ceramic, ultimately influencing the performance of the glass-ceramic product. Different heating rates can result in different structures and properties for the glass-ceramic product. In the glass precursor prepared according to the formula of this invention, when the heating rate is maintained within the range of 0–20 °C / min during crystallization, impurity crystalline phases, such as Li-containing crystalline phases (β-spodumene, etc.), quartz, and quartz solid solutions, are easily precipitated in the glass-ceramic. The inventors have discovered that the presence of impurity crystalline phases such as β-quartz, β-quartz solid solutions, and β-spodumene in the spinel microcrystal system severely affects the optical properties of the spinel glass-ceramic material, causing fogging or even devitrification after crystallization, resulting in a significant decrease in the transmittance of the prepared glass-ceramic product. This situation is undesirable for cover glass products. When the heating rate is greater than 20°C / min, preferably greater than or equal to 25°C / min, and more preferably greater than or equal to 30°C / min, the Li ions introduced into the glass composition will always remain in the glass phase, which is prone to ion exchange. Other impurity crystalline phases that affect the optical properties of glass ceramics will not precipitate, and the transmittance of spinel glass ceramics will not be affected. For details, please refer to [link to relevant documentation]. Figure 4 and Figure 5 .

[0180] Depend on Figure 4 It is known that when crystallization is performed and the heating rate is maintained within the range of 0–20 °C / min, impurity crystals will precipitate in the glass (obvious redundant characteristic peaks appear on the XRD pattern), mainly β-quartz, β-quartz solid solution, β-spodumene and other crystalline phases, combined with Figure 5 It is known that these impurity crystalline phases precipitated in glass can severely affect the optical properties of the glass, causing it to fog or even become opaque. However, during crystallization treatment, when the heating rate is greater than 20℃ / min and reaches 30℃ / min, no impurity crystals precipitate, and the glass remains transparent. In this invention, the heating rate during crystallization treatment includes all ranges and sub-ranges between 20℃ / min and 35℃ / min, such as 21–30℃ / min, 22–25℃ / min, 25–30℃ / min, 23–28℃ / min, 22–30℃ / min, 23–30℃ / min, 24–30℃ / min, 25–28℃ / min, and 21–35℃ / min. In some embodiments, the heating rate during crystallization treatment can be 21°C / min, 22°C / min, 23°C / min, 24°C / min, 25°C / min, 28°C / min, 30°C / min, 35°C / min, etc.

[0181] The heating rate during nucleation affects the formation and number of crystal nuclei, ultimately influencing the crystallinity and intrinsic strength of the glass-ceramic. In this invention, the heating rate during nucleation includes all ranges and sub-ranges within the range of 5–20 °C / min, such as 5–10 °C / min, 10–20 °C / min, 11–20 °C / min, 12–15 °C / min, 9–20 °C / min, 13–20 °C / min, 10–19 °C / min, and 9–17 °C / min. In some embodiments, the heating rate during nucleation can be 5 °C / min, 9 °C / min, 10 °C / min, 11 °C / min, 12 °C / min, 13 °C / min, 15 °C / min, 16 °C / min, 17 °C / min, 19 °C / min, and 20 °C / min.

[0182] III. The present invention also provides a strengthened glass-ceramic. The strengthened glass-ceramic of the present invention is obtained by chemical strengthening and ion exchange of the above-mentioned transparent spinel glass-ceramic; the strengthened glass-ceramic has a compressive stress region extending from its surface to its compression depth. The strengthened glass-ceramic includes a compressive stress layer located on the surface and a tensile stress layer located internally. The compressive stress layer is the compressive stress region formed by chemical strengthening, and the tensile stress layer is the region that has not undergone ion exchange. The composition of the tensile stress layer of the strengthened glass-ceramic is the same as that of the above-mentioned transparent spinel glass-ceramic.

[0183] In practice, the aforementioned transparent spinel glass-ceramic can be prepared by performing one or more ion exchange steps in a salt bath.

[0184] The aforementioned transparent spinel glass-ceramics can undergo chemical strengthening. During the chemical strengthening ion exchange process, the glass-ceramics will undergo K-ion exchange stepwise or simultaneously. + -Na + Na + -Li + Binary ion exchange is used to give the glass ceramic a composite compressive stress layer after ion exchange, so that the strengthened glass ceramic has a compressive stress region extending from its surface to the compression depth.

[0185] The aforementioned transparent spinel glass-ceramics can be enhanced through multiple ion exchange processes. By employing ion exchange salt baths with different ion concentrations, stress profiles are generated at selected depths, resulting in reinforced glass-ceramics with excellent stress properties.

[0186] The reinforced glass-ceramic provided by this invention comprises spinel crystals and zirconium oxide crystals in its crystalline phase, but does not contain Li-containing crystals, quartz, or quartz solid solutions. The spinel crystals include zinc spinel and magnesium spinel, and / or solid solutions of zinc spinel (ZnAl₂O₄) and magnesium spinel (MgAl₂O₄). The reinforced glass-ceramic exhibits a crystallinity of at least 30.00 wt%, and the average crystal size in the reinforced glass-ceramic is less than or equal to 15.0 nm. At a thickness of 0.7 mm, the reinforced glass-ceramic has a transmittance of greater than 85.00% at 550 nm.

[0187] The compressive stress layer depth DOL_0 of the reinforced glass ceramic of the present invention is greater than or equal to 14% of the thickness of the reinforced glass ceramic. Due to the increase in Li2O and Na2O content, there are more Na ions and Li ions available for ion exchange in the glass ceramic, which can form a higher compressive stress layer depth.

[0188] When the glass-ceramic thickness is 0.7 mm, the range of DOL_0 is greater than or equal to 100.0 μm, including all ranges and sub-ranges of DOL_0 greater than or equal to 100.0 μm, such as 100.0~125.0 μm, 100.0~127.0 μm, 100.0~135.0 μm, 100.0~140.0 μm, 100.0~112.0 μm, 100.0~115.0 μm, 100.0~116.0 μm, 100.0~112.0 μm, 104.0~120.0 μm, 106.0~111.0 μm, 108.0~120.0 μm, 104.0~120.0 μm, 108.0~120.0 μm, etc. In some implementations, DOL_0 can be 100.0μm, 104.0μm, 106.0μm, 108.0μm, 111.0μm, 112.0μm, 115.0μm, 116.0μm, 120.0μm, 125.0μm, 127.0μm, 135.0μm, 140.0μm, etc.

[0189] The tensile stress linear density CT_LD of the reinforced glass ceramic of the present invention is greater than or equal to 25000 MPa / mm, including all ranges and sub-ranges between 25000 MPa / mm and therebetween, such as 25000~40000 MPa / mm, 27000~40000 MPa / mm, 25000~38000 MPa / mm, 25000~37000 MPa / mm, 25000~39000 MPa / mm, 27000~38000 MPa / mm, 27000~39000 MPa / mm, 28000~38000 MPa / mm, etc. In some implementations, CT_LD can be 25000MPa / mm, 27000MPa / mm, 28000MPa / mm, 37000MPa / mm, 38000MPa / mm, 39000MPa / mm, 40000MPa / mm, etc.

[0190] The surface compressive stress CS of the reinforced glass ceramic of the present invention is greater than or equal to 650 MPa, including all ranges and sub-ranges between CS and CS greater than or equal to 650 MPa, for example, preferably greater than or equal to 680 MPa, preferably greater than or equal to 700 MPa, preferably greater than or equal to 750 MPa, preferably greater than or equal to 800 MPa, preferably greater than or equal to 900 MPa, preferably greater than or equal to 1000 MPa, preferably 700-800 MPa, preferably 750-800 MPa, preferably 760-870 MPa, preferably 710-860 MPa, preferably 700-900 MPa, preferably 800-1000 MPa, preferably 850-1000 MPa, etc. In some implementations, CS can be 650MPa, 680MPa, 700MPa, 710MPa, 750MPa, 760MPa, 800MPa, 850MPa, 860MPa, 870MPa, 900MPa, 1000MPa, etc.

[0191] The average tensile stress CT_AV of the reinforced glass ceramic of the present invention is greater than or equal to 35.0 MPa, including all ranges and sub-ranges between CT_AV and 35.0 MPa, for example, preferably greater than or equal to 39.0 MPa, preferably greater than or equal to 40.0 MPa, preferably greater than or equal to 45.0 MPa, preferably greater than or equal to 50.0 MPa, preferably greater than or equal to 55.0 MPa, preferably greater than or equal to 60.0 MPa, preferably greater than or equal to 65.0 MPa, preferably greater than or equal to 70.0 MPa, preferably greater than or equal to 75.0 MPa, preferably 39.0 MPa to 65.0 MPa, preferably 35.0 MPa to 65.0 MPa, preferably 35.0 MPa to 55.0 MPa, preferably 35.0 MPa to 70.0 MPa, etc. In some implementations, CT_AV can be 35.0MPa, 39.0MPa, 40.0MPa, 45.0MPa, 50.0MPa, 55.0MPa, 60.0MPa, 65.0MPa, 70.0MPa, 75.0MPa, etc.

[0192] The reinforced glass ceramic of the present invention has a Vickers hardness greater than or equal to 740HV0.3, where 740 is the Vickers hardness and 0.3 refers to the load value used for measurement being 0.3 kg. This includes all ranges and sub-ranges greater than or equal to 740HV0.3 and in between, for example, preferably greater than or equal to 760HV0.3, preferably greater than or equal to 770HV0.3, preferably greater than or equal to 780HV0.3, preferably greater than or equal to 790HV0.3, preferably greater than or equal to 800HV0.3, preferably greater than or equal to 820HV0.3, preferably greater than or equal to 830HV0.3, preferably 740HV0.3~780HV0.3, preferably 740HV0.3~830HV0.3, etc. In some implementations, the Vickers hardness can be 740HV0.3, 760HV0.3, 770HV0.3, 780HV0.3, 790HV0.3, 800HV0.3, 820HV0.3, 830HV0.3, etc.

[0193] The fracture toughness of the reinforced glass-ceramic of the present invention is greater than or equal to 1.500 MPa·m. 1 / 2 The fracture toughness of the reinforced glass-ceramic includes a value greater than or equal to 1.500 MPa·m. 1 / 2 and all ranges and subranges thereof, preferably greater than or equal to 1.560 MPa·m 1 / 2 The preferred pressure is 1.500–1.560 MPa·m. 1 / 2 The preferred pressure is 1.600–1.700 MPa·m. 1 / 2The preferred value is 1.500–1.590 MPa·m. 1 / 2 The preferred value is 1.540–1.600 MPa·m 1 / 2 The preferred value is 1.500–1.610 MPa·m 1 / 2 The preferred value is 1.500–1.630 MPa·m 1 / 2 The preferred value is 1.500–1.700 MPa·m. 1 / 2 In some embodiments, the fracture toughness of the reinforced glass-ceramic can be 1.500 MPa·m. 1 / 2 1.540 MPa·m 1 / 2 1.560 MPa·m 1 / 2 1.590 MPa·m 1 / 2 1.600 MPa·m 1 / 2 1.610 MPa·m 1 / 2 1.630 MPa·m 1 / 2 1.700 MPa·m 1 / 2 wait.

[0194] In this invention, regardless of whether the transparent spinel glass-ceramic undergoes a single ion exchange or multiple ion exchanges, since the glass-ceramic has already achieved an increase in intrinsic strength, a reinforced glass-ceramic product with better performance can be obtained after ion exchange.

[0195] The salt bath used in this invention includes at least one of potassium salts and sodium salts. Nitrates are conventional for the salts used for ion exchange, but any suitable salt or combination of salts may also be used.

[0196] During one-step ion exchange, the salt bath composition includes: 50–100 wt% NaNO3 + 0–50 wt% KNO3, the ion exchange temperature is 400–500 °C, and the ion exchange time is 0.5–48 h. Here, "ion exchange time" refers to the time during which the glass ceramic is placed in a salt bath with the specified temperature and composition for chemical strengthening.

[0197] The ion exchange temperature includes all ranges and sub-ranges between 400 and 500℃, such as 400–500℃, 400–410℃, 400–420℃, 400–430℃, 400–440℃, 400–450℃, 400–460℃, 400–470℃, 410–450℃, 430–500℃, and 440–500℃. The ion exchange time includes all ranges and sub-ranges between 0.5 and 48h, such as 0.5–46h, 1–10h, 1–5h, 1–40h, 7–30h, 9–29h, 10–41h, 6–32h, 9–27h, 4–33h, 5–27h, and 6–38h.

[0198] The salt bath composition includes 50–100 wt% NaNO3 and all ranges and subranges thereof, such as 50–60 wt%, 50–70 wt%, 50–80 wt%, 50–90 wt%, 60–100 wt%, 70–100 wt%, 80–100 wt%, 50–89 wt%, 64–88 wt%, 90–100 wt%, etc.; and 0–50 wt% KNO3 and all ranges and subranges thereof, such as 0–40 wt%, 0–30 wt%, 0–20 wt%, 0–10 wt%, 0–14 wt%, 0–15 wt%, 0–35 wt%, 0–45 wt%, 5–40 wt%, 20–30 wt%, etc.

[0199] When performing a two-step ion exchange, the first step involves a salt bath composition of 90–100 wt% NaNO3 + 0–10 wt% KNO3, an ion exchange temperature of 400–500 °C, and an ion exchange time of 0.5–48 h.

[0200] The second step involves a salt bath consisting of 0–10 wt% NaNO3 and 90–100 wt% KNO3. The ion exchange temperature is 400–500℃, and the ion exchange time is 0.5–48 h.

[0201] The ion exchange temperature includes all ranges and sub-ranges between 400 and 500℃, such as 400–500℃, 400–410℃, 400–420℃, 400–430℃, 400–440℃, 400–450℃, 400–460℃, 400–470℃, 410–450℃, 430–500℃, and 440–500℃. The ion exchange time includes all ranges and sub-ranges between 0.5 and 48h, such as 0.5–46h, 1–10h, 1–5h, 1–40h, 7–30h, 9–29h, 10–41h, 6–32h, 9–27h, 4–33h, 5–27h, and 6–38h.

[0202] The first step salt bath composition includes 90–100 wt% NaNO3 and all ranges and subranges thereof, such as 91–100 wt%, 92–100 wt%, 93–100 wt%, 94–100 wt%, 95–100 wt%, 96–100 wt%, 97–100 wt%, 98–100 wt%, 99–100 wt%, etc.; and also includes 0–10 wt% KNO3 and all ranges and subranges thereof, such as 0–1 wt%, 0–2 wt%, 0–3 wt%, 0–4 wt%, 5–10 wt%, 2–10 wt%, 6–9 wt%, 3–8 wt%, 2–9 wt%, 1–8 wt%, etc.

[0203] The second step salt bath composition includes 0–10 wt% NaNO3 and all ranges and subranges therein, such as 0–1 wt%, 0–2 wt%, 0–3 wt%, 0–4 wt%, 2–10 wt%, 3–5 wt%, 5–10 wt%, 6–10 wt%, 2–7 wt%, 3–7 wt%, etc.; it also includes 90–100 wt% KNO3 and all ranges and subranges therein, such as 91–100 wt%, 92–100 wt%, 93–100 wt%, 94–100 wt%, 95–100 wt%, 96–100 wt%, 97–100 wt%, 98–100 wt%, etc.

[0204] To improve the service life of a salt bath, a salt bath protectant comprising 0.1–5 wt% of the salt bath's mass can be added. This salt bath protectant includes agents for passivating, precipitating, or absorbing Li. + Substances such as phosphates, silicates, and carbonates can be used for passivation, precipitation, or absorption of Li. + The substance is used as a salt bath protectant to prevent the Li exchanged during the salt bath from being damaged. + Increased concentration affects the ion exchange performance and lifespan of the salt bath. Salt bath preservatives include all ranges and subranges from 0.1 to 5.0 wt%, such as 0.1–4.0 wt%, 0.1–3.0 wt%, 0.1–2.0 wt%, 0.1–1.0 wt%, 0.2–5.0 wt%, 0.5–5.0 wt%, 4.1–5.0 wt%, 3.1–5.0 wt%, 2.6–4.5 wt%, 0.7–3.5 wt%, 0.8–2.5 wt%, 0.9–1.5 wt%, 0.8–2.5 wt%, etc.

[0205] IV. The present invention also provides an electronic terminal as a consumer product. The electronic terminal of the consumer product provided by the present invention includes a housing, the housing including a front surface, a rear surface and a side surface.

[0206] And some electronic components located within the housing, the electronic components including a display device located on or adjacent to the front surface of the housing;

[0207] The front surface and / or rear surface and / or side surface comprise the reinforced glass-ceramic material described above;

[0208] It also includes a cover article covering the front surface of the housing or located on the display device, the cover article comprising the aforementioned reinforced glass-ceramic material;

[0209] The electronic terminals mentioned as consumer products include mobile phones, tablet computers, photovoltaic devices, or other electronic terminals (such as electronic watches).

[0210] The transparent spinel glass-ceramic material and the reinforced glass-ceramic material in this invention have excellent properties and can be included / applied in other products, such as watches, transparent armor, missile windows, fairings, substrate materials, new lamps, observation windows of equipment in high temperature, high pressure and corrosive environments, display protection materials and outer shell protection materials for portable smart electronic devices (portable smart electronic devices include mobile phones, tablets, electronic watches, etc.), building products, transportation products (e.g., automobiles, trains, airplanes, marine vehicles, etc.), appliances, or any product that requires a certain degree of transparency, scratch resistance, impact resistance, wear resistance or a combination thereof.

[0211] V. The present invention will be described below through specific embodiments.

[0212] Table 1 lists the glass-ceramic material formulas for schemes 1 to 6 in this invention.

[0213]

[0214]

[0215] Table 2 shows the glass-ceramic material formulas for schemes 7-12 in this invention.

[0216] Basic glass composition (mol%) Option 7 Option 8 Option 9 Option 10 Option 11 Option 12 <![CDATA[SiO2]]> 62.60 62.34 61.88 51.13 50.81 50.49 <![CDATA[Al2O3]]> 15.05 14.99 14.88 15.80 15.70 15.60 <![CDATA[TiO2]]> 0.32 0.32 0.32 1.22 1.21 1.20 <![CDATA[ZrO2]]> 3.02 3.01 2.99 4.07 4.04 4.02 MgO 4.03 4.01 3.98 4.10 4.07 4.05 ZnO 8.13 8.10 8.04 15.20 15.11 15.01 <![CDATA[Na2O]]> 3.05 3.03 3.01 3.55 3.54 3.52 <![CDATA[Li2O]]> 3.80 4.20 4.90 3.60 4.20 4.80 BaO 0.00 0.00 0.00 1.33 1.32 1.31

[0217] Table 3 lists the glass-ceramic material formulas for comparative schemes 13-16 in this invention.

[0218] Basic glass composition (mol%) Comparison Option 13 Comparison Option 14 Comparison Option 15 Comparison Option 16 <![CDATA[SiO2]]> 53.94 54.44 51.02 59.25 <![CDATA[Al2O3]]> 19.50 19.50 22.01 15.33 <![CDATA[TiO2]]> 0.89 0.89 0.88 0.79 <![CDATA[ZrO2]]> 3.02 3.02 3.53 3.01 MgO 5.67 5.67 5.12 5.02 ZnO 9.86 9.86 10.26 9.22 <![CDATA[Na2O]]> 3.45 3.45 3.02 3.22 <![CDATA[Li2O]]> 2.50 2.00 3.00 3.00 BaO 1.17 1.17 1.16 1.16

[0219] Table 4 shows the properties of the glass-ceramics prepared in Examples 1-2 and Comparative Examples 13-16, as well as the corresponding reinforced glass-ceramics.

[0220]

[0221]

[0222] Note: DOL_0 is the compressive stress depth generated after the exchange of Li ions in the glass ceramic with Na ions in the salt bath;

[0223] DOL_2 is the depth of compressive stress generated by the exchange of Na ions in glass ceramics with K ions in the salt bath.

[0224] "450-3H" means that the ion exchange temperature is 450℃ and the ion exchange time is 3h. Other similar expressions have similar meanings.

[0225] "100% NaNO3" means 100 wt% NaNO3, and other similar expressions have similar meanings.

[0226] Table 5 shows the properties of the glass ceramics prepared in Examples 3-7 and the corresponding reinforced glass ceramics.

[0227]

[0228]

[0229] Note: DOL_0 is the compressive stress depth generated after the exchange of Li ions in the glass ceramic with Na ions in the salt bath;

[0230] DOL_2 is the depth of compressive stress generated by the exchange of Na ions in glass ceramics with K ions in the salt bath.

[0231] "450-3H" means that the ion exchange temperature is 450℃ and the ion exchange time is 3h. Other similar expressions have similar meanings.

[0232] "100% NaNO3" means 100 wt% NaNO3, and other similar expressions have similar meanings.

[0233] Table 6 shows the properties of the glass ceramics prepared in Examples 8-12 and the corresponding reinforced glass ceramics.

[0234]

[0235]

[0236] Note: DOL_0 is the compressive stress depth generated after the exchange of Li ions in the glass ceramic with Na ions in the salt bath;

[0237] DOL_2 is the depth of compressive stress generated by the exchange of Na ions in glass ceramics with K ions in the salt bath.

[0238] "450-3H" means that the ion exchange temperature is 450℃ and the ion exchange time is 3h. Other similar expressions have similar meanings.

[0239] "100% NaNO3" means 100 wt% NaNO3, and other similar expressions have similar meanings.

[0240] Table 7 shows the glass-ceramics prepared in Comparative Examples 1–6.

[0241]

[0242] Note: The quartz solid solution precipitated in the above comparative examples is mainly β-quartz solid solution.

[0243] Table 8 shows the glass-ceramics prepared in Comparative Examples 7–12.

[0244]

[0245]

[0246] Note: The quartz solid solution precipitated in the above comparative examples is mainly β-quartz solid solution.

[0247] Taking Example 1 as an example, the materials were mixed according to the formula in Scheme 1 for 30 minutes, with a total volume of 1000g. After thorough mixing, 5g of clarifying agent (NaCl) was added, and the mixture was melted in a platinum crucible at 1650℃ for 20 hours. The mixture was then poured into a molding die, cooled to 900℃, and annealed in a 600℃ annealing furnace for 6 hours. After annealing in the furnace to room temperature, a glass precursor was obtained. The glass precursor was then subjected to nucleation and crystallization treatments according to the corresponding process conditions in the table above to produce glass-ceramic products. The obtained glass-ceramic products were then chemically strengthened according to the corresponding strengthening process conditions in the table above to produce strengthened glass-ceramic products.

[0248] As can be seen from Tables 1-6, because the content of Li₂O and Na₂O in the glass frits of Comparative Examples 13-16 is lower than that in Examples 1-12, the CT_LD of the glass ceramics prepared from them after strengthening treatment is much lower than that of Examples 1-12, and some even fail to reach 20000 MPa / mm. The drop resistance of the strengthened glass ceramics prepared from the glass ceramics of Examples 1-12 is significantly better than that of Comparative Examples 13-16.

[0249] Ten pieces of each of the reinforced glass-ceramics from Comparative Examples 13 and 15, and Examples 5, 6, 11, and 12 were subjected to whole-machine drop tests. The test results are shown in the figure. Figure 1 .according to Figure 1It can be seen that Comparative Examples 13 and 15 exhibited poor drop performance, with drop heights concentrated between 0.7 and 1.7 m. Examples 5, 6, 11, and 12, due to their higher Li₂O content in the formulation, showed a significant increase in tensile stress linear density (CT_LD) and stress depth (DOL_0) after strengthening treatment, resulting in a significantly improved drop height. Meanwhile, Examples 12 and 6 showed comparable CT_LD levels, indicating that Example 12, with its higher crystallinity, had a significantly higher drop height; only 2 out of the 10 glass pieces dropped had a drop height below 2 m. This demonstrates that in strengthened glass ceramics, drop height is related to both crystallinity and CT_LD. This invention, by ensuring crystallinity while adding a larger amount of Li₂O, ensures a high CT_LD after strengthening and good drop resistance.

[0250] As can be seen from Tables 7 and 8, the heating rate during the crystallization process has a significant impact on the crystal phase type of glass ceramics. In Comparative Examples 1 to 12, when the crystallization heating rate is less than 20℃ / min, impurity quartz solid solution appears in the crystal phase of the glass ceramic material, and the grain size is significantly larger. Although the crystallinity is improved, the transmittance decreases significantly, and the refractive index cannot even be measured. Such glass ceramics cannot meet the requirements as cover plate materials.

[0251] The glass precursor obtained from the material formulation in Scheme 8 was subjected to microcrystallization treatment at different crystallization heating rates (5℃ / min, 20℃ / min, 30℃ / min). Photos of the resulting glass-ceramics are shown below. Figure 5 The XRD pattern of the prepared glass-ceramic is shown in [reference needed]. Figure 4 The transmittance of the prepared glass-ceramic to 550nm wavelength light is shown in the figure. Figure 6 .pass Figure 4-6 It can be seen that during crystallization treatment, when the heating rate is in the range of 0–20℃ / min, impurity crystals will precipitate in the glass (obvious redundant characteristic peaks appear on the XRD pattern), and the glass ceramic will become hazy or even devitrified. However, when the crystallization treatment is carried out at a heating rate of 30℃ / min, no impurity crystals precipitate, and the glass remains transparent.

[0252] This invention optimizes the composition of spinel glass-ceramic materials by introducing more Li and Na ions for chemically enhanced ion exchange into the spinel glass-ceramic, resulting in spinel glass-ceramic free of impurity crystalline phases (such as impurity crystalline phases containing Li, quartz, quartz solid solution, etc.). The glass-ceramic does not exhibit phenomena such as fogging or devitrification, ensuring that the glass-ceramic material has excellent transmittance.

[0253] By introducing more Li and Na ions into the spinel glass-ceramic composition, the resulting spinel glass-ceramic can be chemically strengthened, resulting in a transparent strengthened glass-ceramic with high CS, DOL_0, CT_AV, and CT_LD, which exhibits excellent drop resistance.

[0254] Performance tests on the glass-ceramic material prepared by this invention revealed that the transparent spinel glass-ceramic material of this invention has a high degree of crystallinity, which brings excellent mechanical properties to the glass-ceramic material.

[0255] The present invention also provides a method for preparing spinel glass ceramics. The process method provided by the present invention controls the process parameters of the crystallization process and the nucleation process, and sets the heating rate parameter requirements, and finally obtains spinel glass ceramics without impurity crystal phases (such as impurity crystal phases containing Li crystal phase, quartz, quartz solid solution and other impurity crystal phases), ensuring that the glass ceramic material has excellent optical properties.

[0256] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A transparent spinel glass-ceramic, characterized in that, The glass-ceramic comprises, by molar percentage of oxides: Li₂O: 3.50~6.00 mol%. Na₂O: 2.00~4.00 mol% SiO2: 50.00~65.00 mol% Al2O3: 14.50~25.00 mol% MgO: 3.50~8.00 mol% ZnO: 8.00~16.00 mol% BaO: 0~2.00 mol% TiO2+ZrO2: 3.00~5.50 mol% The glass-ceramic contains, by molar percentage of oxides: 0.40≤(Al2O3+ZnO+MgO+ZrO2+TiO2) / (Li2O+Na2O+SiO2+BaO)≤0.70; The glass-ceramic crystal phase contains spinel crystals and zirconium oxide crystals, but does not contain Li-containing crystals; The crystalline phase of the glass-ceramic does not contain quartz or quartz solid solution.

2. The transparent spinel glass-ceramic according to claim 1, characterized in that, The glass-ceramic exhibits a crystallinity of at least 30.00 wt%.

3. The transparent spinel glass-ceramic according to claim 1, characterized in that, The average crystal size in the glass-ceramic is less than or equal to 15.00 nm.

4. The transparent spinel glass-ceramic according to claim 1, characterized in that, The spinel crystals include zinc spinel and magnesium spinel.

5. The transparent spinel glass-ceramic according to claim 1, characterized in that, At a thickness of 0.70 mm, the glass-ceramic has a transmittance of greater than 85.00% at a wavelength of 550.00 nm.

6. The transparent spinel glass-ceramic according to claim 1, characterized in that, The glass-ceramic contains, by molar percentage of oxides: 0.43≤(Al2O3+ZnO+MgO+ZrO2+TiO2) / (Li2O+Na2O+SiO2+BaO)≤0.

68.

7. The transparent spinel glass-ceramic according to claim 1, characterized in that, The glass-ceramic contains, by molar percentage of oxides: Na2O / (Li2O+Na2O+SiO2+BaO)≥0.035; and / or Li2O / (Li2O+Na2O+SiO2+BaO)≥0.

054.

8. The transparent spinel glass-ceramic according to claim 7, characterized in that, The glass-ceramic contains, by molar percentage of oxides: 0.035≤Na2O / (Li2O+Na2O+SiO2+BaO) ≤0.070; and / or 0.054≤Li2O / (Li2O+Na2O+SiO2+BaO) ≤0.

090.

9. The transparent spinel glass-ceramic according to claim 1, characterized in that, The glass-ceramic comprises, by molar percentage of oxides: SiO2: 50.00~63.00 mol%; and / or Al2O3: 14.50~20.00 mol%; and / or MgO: 3.90~7.60 mol%; and / or ZnO: 8.00~15.50 mol%; and / or BaO: 0~1.50 mol%; and / or Li₂O: 3.50~5.00 mol%; and / or Na₂O: 2.30~3.60 mol%; and / or TiO2: 0~2.00 mol%; and / or ZrO2: 2.50~5.00 mol%.

10. The transparent spinel glass-ceramic according to claim 1, characterized in that, The glass-ceramic comprises, by molar percentage of oxides: SiO2: 50.00~57.00 mol%; and / or Al2O3: 15.00~19.00 mol%; and / or MgO: 4.00~7.50 mol%; and / or ZnO: 9.00~15.20 mol%; and / or BaO: 1.00~1.35 mol%; and / or Li₂O: 4.00~5.00 mol%; and / or Na₂O: 3.00~3.60 mol%; and / or TiO2: 0.30~1.30 mol%; and / or ZrO2: 2.90~4.20 mol%.

11. The method for preparing transparent spinel glass-ceramic according to any one of claims 1 to 10, characterized in that, Includes the following steps: (1) Mix the ingredients according to the formula to prepare the glass precursor; (2) The obtained glass precursor is subjected to nucleation and crystallization treatment in sequence to prepare the transparent spinel glass ceramic; in step (2), when crystallization treatment is performed, the temperature is increased to the crystallization temperature at a heating rate of more than 20℃ / min.

12. The preparation method according to claim 11, characterized in that, In step (2): During nucleation, the nucleation temperature is 700–800℃ and the nucleation time is 30–1440 min. When performing crystallization treatment, the crystallization temperature is 900-1000℃ and the crystallization time is 5-1440 min.

13. The preparation method according to claim 11, characterized in that, In step (2), during the crystallization process, the temperature is increased to the crystallization temperature at a rate greater than or equal to 25°C / min.

14. The preparation method according to claim 13, characterized in that, In step (2), during the crystallization process, the temperature is increased to the crystallization temperature at a rate greater than or equal to 30°C / min.

15. The preparation method according to claim 12, characterized in that, In step (2), during the nucleation process, the temperature is increased to the nucleation temperature at a rate of 5 to 20 °C / min.

16. The preparation method according to claim 15, characterized in that, In step (2), during the nucleation process, the temperature is increased to the nucleation temperature at a rate of 10℃ / min.

17. A reinforced glass ceramic, characterized in that: The reinforced glass-ceramic is obtained by chemically strengthening ion exchange of the transparent spinel glass-ceramic according to any one of claims 1 to 10; the reinforced glass-ceramic has a compressive stress region extending from its surface to the compression depth.

18. The reinforced glass-ceramic according to claim 17, characterized in that: The composition of the reinforced glass-ceramic tensile stress layer, based on the molar percentage of oxides, comprises: Li₂O: 3.50~6.00 mol% Na₂O: 2.00~4.00 mol% SiO2: 50.00~65.00 mol% Al2O3: 14.50~25.00 mol% MgO: 3.50~8.00 mol% ZnO: 8.00~16.00 mol% BaO: 0~2.00 mol% TiO2+ZrO2: 3.00~5.50 mol% The composition of the reinforced glass-ceramic tensile stress layer, by molar percentage of oxides, is as follows: 0.40≤(Al2O3+ZnO+MgO+ZrO2+TiO2) / (Li2O+Na2O+SiO2+BaO)≤0.

70.

19. The reinforced glass ceramic according to claim 18, characterized in that: The composition of the reinforced glass-ceramic tensile stress layer, in terms of the molar percentage of oxides, is as follows: 0.40≤(Al2O3+ZnO+MgO+ZrO2+TiO2) / (Li2O+Na2O+SiO2+BaO)≤0.70; and / or, Na2O / (Li2O+Na2O+SiO2+BaO)≥0.035; and / or Li2O / (Li2O+Na2O+SiO2+BaO)≥0.

054.

20. The reinforced glass ceramic according to claim 18, characterized in that: The composition of the reinforced glass-ceramic tensile stress layer, based on the molar percentage of oxides, includes: SiO2: 50.00~63.00 mol%; and / or Al2O3: 14.50~20.00 mol%; and / or MgO: 3.90~7.60 mol%; and / or ZnO: 8.00~15.50 mol%; and / or BaO: 0~1.50 mol%; and / or Li₂O: 3.50~5.00 mol%; and / or Na₂O: 2.30~3.60 mol%; and / or TiO2: 0~2.00 mol%; and / or ZrO2: 2.50~5.00 mol%.

21. The reinforced glass-ceramic according to claim 18, characterized in that: The composition of the reinforced glass-ceramic tensile stress layer, based on the molar percentage of oxides, includes: SiO2: 50.00~57.00 mol%; and / or Al2O3: 15.00~19.00 mol%; and / or MgO: 4.00~7.50 mol%; and / or ZnO: 9.00~15.20 mol%; and / or BaO: 1.00~1.35 mol%; and / or Li₂O: 4.00~5.00 mol%; and / or Na₂O: 3.00~3.60 mol%; and / or TiO2: 0.30~1.30 mol%; and / or ZrO2: 2.90~4.20 mol%.

22. The reinforced glass ceramic according to claim 18, characterized in that: The composition of the reinforced glass-ceramic tensile stress layer, by molar percentage of oxides, is as follows: 0.43≤(Al2O3+ZnO+MgO+ZrO2+TiO2) / (Li2O+Na2O+SiO2+BaO)≤0.68; and / or, 0.035≤Na2O / (Li2O+Na2O+SiO2+BaO) ≤0.070; and / or 0.054≤Li2O / (Li2O+Na2O+SiO2+BaO) ≤0.

090.

23. The reinforced glass ceramic according to claim 18, characterized in that: The crystalline phase of the strengthened glass-ceramic contains spinel crystals and zirconium oxide crystals, but does not contain Li-containing crystals; and / or, The reinforced glass-ceramic exhibits at least 30.00 wt% crystallinity, and the average crystal size in the reinforced glass-ceramic is less than or equal to 15.0 nm.

24. The reinforced glass ceramic according to claim 23, characterized in that: The spinel crystals include zinc spinel and magnesium spinel, and / or a solid solution of zinc spinel (ZnAl2O4) and magnesium spinel (MgAl2O4); and / or, The crystalline phase of the reinforced glass ceramic does not contain quartz or quartz solid solution.

25. The reinforced glass-ceramic according to claim 17, characterized in that: At a thickness of 0.7 mm, the reinforced glass-ceramic exhibits a transmittance greater than 85.00% at 550 nm; and / or, The compressive stress layer depth DOL_0 of the reinforced glass-ceramic is greater than or equal to 14% of the thickness of the reinforced glass-ceramic; and / or, The tensile stress linear density CT_LD of the reinforced glass-ceramic is greater than or equal to 25000 MPa / mm; and / or, The surface compressive stress CS of the reinforced glass-ceramic is greater than or equal to 650 MPa; and / or, The average tensile stress CT_AV of the reinforced glass ceramic is greater than or equal to 35.0 MPa; and / or, The fracture toughness of the reinforced glass-ceramic is greater than or equal to 1.500 MPa·m. 1 / 2 .

26. The reinforced glass ceramic according to claim 25, characterized in that: The tensile stress linear density CT_LD of the strengthened glass-ceramic is 25000~40000MPa / mm; and / or, The surface compressive stress CS of the reinforced glass-ceramic is 650MPa~1000MPa; and / or, The average tensile stress CT_AV of the reinforced glass ceramic is 35.0 MPa to 75 MPa; and / or, The fracture toughness of the reinforced glass-ceramic is 1.500 MPa·m. 1 / 2 ~1.700MPa·m 1 / 2 .

27. The application of the transparent spinel glass ceramics of any one of claims 1 to 10 and the reinforced glass ceramics of any one of claims 17 to 26 in watches, transparent armor, missile windows, fairings, substrate materials, lamps, observation windows of equipment in high temperature, high pressure and corrosive environments, automobiles, trains, airplanes, marine vehicles, building materials and portable smart electronic devices.

28. An electronic device, characterized in that, The electronic device includes transparent spinel glass-ceramics as described in any one of claims 1 to 10 and reinforced glass-ceramics as described in any one of claims 17 to 26.

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