Impact-resistant optical microcrystalline glass, and preparation method and application thereof

Abstract

The application provides an impact-resistant optical microcrystalline glass and a preparation method and application thereof. According to mass percentage, the impact-resistant optical microcrystalline glass comprises SiO2 30-50%, Al2O3 23-42%, Na2O 4-12%, CaO 4-12%, MgO 0.5-9%, and the impact-resistant optical microcrystalline glass is diffused with nano-alumina. The microcrystalline glass has good optical performance, and the diffused nano-alumina fine crystals can hinder the crack diffusion in the glass matrix, and improve the impact resistance of the microcrystalline glass. Meanwhile, the crack expansion on the surface of the microcrystalline glass can be inhibited through the high numerical value and high depth surface compressive stress layer on the surface of the microcrystalline glass, and the nano-alumina fine crystals and the surface compressive stress layer synergistically act, so that the microcrystalline glass has high impact resistance.

Description

Technical Field

[0001] This invention belongs to the field of microcrystalline glass technology, and relates to high impact-resistant microcrystalline glass, its preparation method and application. Background Technology

[0002] From the current development trend of optical glass, microcrystalline glass is widely regarded as the main development direction of high-performance display materials and lens materials due to its better comprehensive mechanical properties compared with traditional glass materials, and has been successfully applied to some high-end mobile phone screens and digital product protective screens in recent years. However, the mainstream microcrystalline display glass currently uses the Li2O-Al2O3-SiO2 material system. By nucleating and growing crystals in the glass casting brick at appropriate temperatures, crystals such as spodumene and lithium disilicate are precipitated in the glass. However, the Mohs hardness of this system of microcrystalline glass is relatively low (about 5-6). At the same time, the polarization ability of Li ions is strong, making it difficult to control the crystallization rate during the preparation of microcrystalline glass, thus making it difficult to control the amount of crystallization and crystal size. This results in large fluctuations in the light transmittance of the prepared cover glass, low product yield, and its impact resistance (drop ball impact height) is insufficient to meet the requirements of some electronic devices in extreme environments. Summary of the Invention

[0003] To address the aforementioned technical problems, the present invention aims to provide high-impact-resistant optical microcrystalline glass, its preparation method, and its applications.

[0004] To achieve the above objectives, the present invention proposes the following technical solution:

[0005] In a first aspect, a high-impact-resistant optical microcrystalline glass is provided, comprising, by mass percentage: 30-50% SiO2, 23-42% Al2O3, 4-12% Na2O, 4-12% CaO, and 0.5-9% MgO, wherein nano-alumina is dispersed in the impact-resistant optical microcrystalline glass.

[0006] Further, it comprises: SiO2 36~46%; and / or Al2O3 25~40%; and / or Na2O 6~12%; and / or CaO 5~9%; and / or MgO 2~8%.

[0007] Furthermore, by mass percentage, the impact-resistant optical microcrystalline glass also contains one or more of the following components: ZrO2 0~5%, K2O 0~6%, Li2O 0~5%, Sb2O3 0~1.5%, SnO2 0~1.5%, P2O5 0~1%, Y2O3 0~1%, La2O3 0~1%.

[0008] Further, it comprises: ZrO2 0.5~5%; and / or K2O 0.5~4%; and / or Li2O 0~3%; and / or Sb2O3 0.05~1%; and / or SnO2 0.05~0.5%; and / or P2O5 0.05~0.8%; and / or Y2O3 0.05~0.5%; and / or La2O3 0.05~0.5%.

[0009] Further, it comprises: ZrO2 1~4.5%; and / or K2O 0.5~3%; and / or Li2O 0.05~2.5%; and / or Sb2O3 0.1~0.5%; and / or SnO2 0.1~0.4%; and / or P2O5 0.05~0.6%; and / or Y2O3 0.05~0.3%; and / or La2O3 0.05~0.3%.

[0010] Furthermore, the grain size of the nano-alumina is less than 50 nm; the nano-alumina is uniformly dispersed in the impact-resistant optical microcrystalline glass.

[0011] Furthermore, the nano-precipitated phase of the microcrystalline glass is nano-alumina crystals.

[0012] Furthermore, the transmittance of 4mm thick microcrystalline glass at a wavelength of 550nm is over 88%.

[0013] Furthermore, the microcrystalline glass has one or more of the following characteristics:

[0014] The surface stress layer depth of the microcrystalline glass is less than 100 μm;

[0015] The surface residual stress of the microcrystalline glass is above 1200 MPa;

[0016] With a thickness of 0.6mm, the impact resistance height relative to a 130g steel ball is over 1500mm;

[0017] With a thickness of 4mm, the impact resistance height relative to a 5kg steel ball is over 300mm;

[0018] The Knoop hardness value of the microcrystalline glass is above 3.5 GPa.

[0019] Furthermore, the microcrystalline glass has one or more of the following characteristics:

[0020] The surface stress layer depth of the microcrystalline glass is 50~100μm;

[0021] The surface residual stress of the microcrystalline glass is above 1300 MPa;

[0022] With a thickness of 0.6mm, the impact resistance height relative to a 130g steel ball is over 1700mm;

[0023] With a thickness of 4mm, the impact resistance height relative to a 5kg steel ball is over 400mm;

[0024] The Knoop hardness value of the microcrystalline glass is 4~6 GPa.

[0025] Secondly, a glass cover is provided, including the aforementioned impact-resistant optical microcrystalline glass.

[0026] Thirdly, glass components are provided, including the aforementioned impact-resistant optical microcrystalline glass and / or the aforementioned glass cover.

[0027] Fourthly, a display device is provided, including the aforementioned impact-resistant optical microcrystalline glass, and / or the aforementioned glass cover plate, and / or the aforementioned glass components.

[0028] Fifthly, providing electronic devices, including the aforementioned impact-resistant optical microcrystalline glass, and / or the aforementioned glass cover, and / or the aforementioned glass components; and / or the aforementioned display devices.

[0029] Sixthly, a method for preparing high-impact-resistant optical microcrystalline glass is provided, comprising: mixing raw materials according to a formula, first heating to a first temperature and holding at that temperature, then heating to a second temperature and holding at that temperature, then heating to a third temperature and holding at that temperature, then casting the resulting molten glass liquid and rapidly cooling it to 800~1000℃ at a cooling rate of 100℃ / min or higher, and then cooling it to below 200℃ at a cooling rate of 5℃ / min or lower.

[0030] Furthermore, the first temperature is 900~1000℃; the holding time at the first temperature is 1~4h; and the temperature is increased to the first temperature at a rate of 3~5℃ / min.

[0031] Furthermore, the second temperature is 1350~1450℃; the holding time at the second temperature is 1~4h; and the temperature is increased to the second temperature at a rate of 2~5℃ / min.

[0032] Furthermore, the third temperature is 1550~1650℃; the holding time at the third temperature is 1~8h; and the temperature is increased to the third temperature at a rate of 2~5℃ / min.

[0033] Furthermore, it is cooled to 800-1000℃ at a cooling rate of 200-300℃ / min.

[0034] Furthermore, it is cooled to below 200°C at a cooling rate of 0.5~3°C / min.

[0035] Furthermore, it also includes a step of chemically strengthening the microcrystalline glass; the chemical strengthening includes immersing the microcrystalline glass in potassium nitrate molten salt at 420~550℃ for 1~16h.

[0036] Compared with the prior art, one or more of the above technical solutions can achieve at least one of the following beneficial effects:

[0037] An impact-resistant optical microcrystalline glass is provided, in which nano-alumina is dispersed. This microcrystalline glass not only has excellent optical properties, but the dispersed nano-alumina crystals can also hinder the propagation of cracks in the glass matrix, thereby improving the impact resistance of the microcrystalline glass. Simultaneously, the high numerical value and deep surface compressive stress layer on the surface of the microcrystalline glass can suppress the propagation of cracks on the microcrystalline glass surface. The synergistic effect of the nano-alumina crystals and the surface compressive stress layer gives the microcrystalline glass high impact resistance.

[0038] This invention employs a high-alumina content microcrystalline glass material system with a specific formulation. After molten glass is rapidly cooled, uniformly dispersed alumina crystals precipitate in the molten glass. Due to the rapid cooling rate, the viscosity of the molten glass increases rapidly, and the diffusion rate decreases rapidly, making it difficult for the precipitated alumina crystals to grow. This process allows for the production of microcrystalline glass materials with finely dispersed alumina crystals in the matrix. Furthermore, during the rapid cooling process, a large number of alumina tetrahedra in the molten glass do not have time to precipitate and remain in the glass network. Since the volume of aluminum-oxygen tetrahedra is larger than that of silicon-oxygen tetrahedra, the glass network structure contains a large number of large-sized aluminum-oxygen tetrahedra. This facilitates ion exchange between potassium ions in the molten salt and sodium ions in the glass during the subsequent KNO3 molten salt chemical strengthening process, enabling the formation of high compressive stress and a deep stress diffusion layer on the glass surface at a relatively low strengthening temperature. This special material structure, on the one hand, allows the fine alumina crystals in the glass matrix to hinder crack propagation within the glass matrix; on the other hand, the high numerical and deep compressive stress layer on the glass surface inhibits crack propagation, giving the glass high impact resistance.

[0039] Compared to the existing nucleation-then-crystallization process, this process has a shorter heat treatment flow, is simpler, and can precipitate alumina nanophase. Furthermore, the amount and size of crystallization are highly controllable, resulting in a higher yield when industrially producing high-performance optical microcrystalline glass. Attached Figure Description

[0040] 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 or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 The image shows the XRD pattern of the glass-ceramic prepared in Example 1.

[0042] Figure 2 This is a SEM image of the microcrystalline glass prepared in Example 1. Detailed Implementation

[0043] Some embodiments of the present invention provide an impact-resistant optical microcrystalline glass, comprising, by mass percentage: 30-50% SiO2, 23-42% Al2O3, 4-12% Na2O, 4-12% CaO, and 0.5-9% MgO, wherein nano-alumina is dispersed in the impact-resistant optical microcrystalline glass.

[0044] In some embodiments, the impact-resistant optical microcrystalline glass contains 30-50% SiO2 by weight percentage, such as 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, etc., preferably 32-48%, and more preferably 36-46%.

[0045] In some embodiments, the impact-resistant optical microcrystalline glass contains 23-42% Al2O3 by weight percentage, such as 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, etc., preferably 25-40%.

[0046] In some embodiments, the impact-resistant optical microcrystalline glass contains 4-12% Na2O by mass percentage, such as 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, etc., preferably 6-12%, and more preferably 7-11%.

[0047] In some embodiments, the impact-resistant optical microcrystalline glass contains 4-12% CaO by weight percentage, such as 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, etc., preferably 5-9%, and more preferably 5-8%.

[0048] In some embodiments, the impact-resistant optical microcrystalline glass contains 0.5-9% MgO by weight percentage, such as 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, etc., preferably 1-8%, and more preferably 2-8%.

[0049] In some preferred embodiments, the impact-resistant optical microcrystalline glass contains ZrO2 0~5% by mass percentage, such as 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc., preferably ZrO2 0.5~5%, and more preferably 1~5%.

[0050] In some preferred embodiments, the impact-resistant optical microcrystalline glass contains 0-6% K2O by weight percentage, such as 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, etc., preferably 0.5-4%, and more preferably 0.5-3%.

[0051] In some preferred embodiments, the impact-resistant optical microcrystalline glass contains 0-5% Li2O by mass percentage, such as 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc., preferably 0.05-3%, and more preferably 0.05-2.5%.

[0052] In some preferred embodiments, the impact-resistant optical microcrystalline glass contains 0-1.5% Sb₂O₃ by mass percentage, for example 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc., preferably 0.05-1%, and more preferably 0.1-0.5%.

[0053] In some preferred embodiments, the impact-resistant optical microcrystalline glass contains 0-1.5% SnO2 by weight, for example 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc., preferably 0.05-1% SnO2, more preferably 0.05-0.5% SnO2, and even more preferably 0.1-0.4% SnO2.

[0054] In some preferred embodiments, the impact-resistant optical microcrystalline glass contains 1% to 50% P2O5, for example, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, etc., preferably 0.05% to 0.8%, and more preferably 0.05% to 0.6%.

[0055] In some preferred embodiments, the impact-resistant optical microcrystalline glass contains 0-1% Y2O3 by mass percentage, such as 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, etc., preferably 0.05-0.5%, and more preferably 0.05-0.3% Y2O3.

[0056] In some preferred embodiments, the impact-resistant optical microcrystalline glass contains 0-1% La2O3 by mass percentage, such as 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, etc., preferably 0.05-0.5%, and more preferably 0.05-0.3%.

[0057] In some preferred embodiments, the grain size of the nano-alumina is no greater than 50nm, such as 50nm, 45nm, 40nm, 35nm, 30nm, 25nm, 20nm, 15nm, 10nm, 5nm, etc.

[0058] In some preferred embodiments, the nano-alumina is uniformly dispersed in impact-resistant optical microcrystalline glass.

[0059] In some preferred embodiments, the nano-precipitated phase of the microcrystalline glass is nano-alumina crystals.

[0060] In some preferred embodiments, the transmittance of the 4mm thick microcrystalline glass at a wavelength of 550nm is 88% or more, more preferably 89% or more, and even more preferably 90% or more.

[0061] In some preferred embodiments, the surface stress layer depth of the microcrystalline glass is less than 100μm, preferably 50~100μm, such as 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, etc.

[0062] In some preferred embodiments, the surface residual stress of the microcrystalline glass is 1200 MPa or more, preferably 1250 MPa or more, and more preferably 1300 MPa, for example 1300~1700 MPa, such as 1350 MPa, 1400 MPa, 1450 MPa, 1500 MPa, 1550 MPa, 1600 MPa, 1650 MPa, 1700 MPa, etc.

[0063] In some preferred embodiments, the impact resistance height relative to a 130g steel ball with a thickness of 0.6mm is 1500mm or more, preferably 1600mm or more, further preferably 1700mm or more, and even more preferably 1800mm or more, such as 1800mm, 1900mm, 2000mm, 2100mm, 2200mm, 2300mm, 2400mm, 2500mm, 2600mm, 2700mm, 2800mm, 2900mm, 3000mm, etc.

[0064] In some preferred embodiments, the impact resistance height relative to a 5kg steel ball with a thickness of 4mm is 300mm or more, preferably 350mm or more, further preferably 400mm or more, and even more preferably 450mm or more, for example 450mm, 500mm, 550mm, 600mm.

[0065] In some preferred embodiments, the Knoop hardness value of the microcrystalline glass is 3.5 GPa or higher, preferably 4 GPa or higher, and more preferably 4 to 6 GPa, such as 4 GPa, 4.2 GPa, 4.5 GPa, 4.8 GPa, 5 GPa, 5.2 GPa, 5.5 GPa, 5.8 GPa, 6 GPa, etc.

[0066] Provide glass cover plates, including the aforementioned impact-resistant optical microcrystalline glass.

[0067] Provide glass components, including the aforementioned impact-resistant optical microcrystalline glass, and / or the aforementioned glass cover plate.

[0068] Provide a display device, including the aforementioned impact-resistant optical microcrystalline glass, and / or the aforementioned glass cover plate, and / or the aforementioned glass components.

[0069] Provide electronic devices, including the aforementioned impact-resistant optical microcrystalline glass, and / or including the aforementioned glass cover, and / or the aforementioned glass components; and / or the aforementioned display devices.

[0070] Some embodiments of the present invention provide a method for preparing the aforementioned impact-resistant optical microcrystalline glass, comprising: mixing raw materials according to the formula, first heating to a first temperature and holding at that temperature, then heating to a second temperature and holding at that temperature, then heating to a third temperature and holding at that temperature, then casting the resulting molten glass liquid and rapidly cooling it to 800~1000°C at a cooling rate of 100°C / min or higher, and then cooling it to below 200°C at a cooling rate of 5°C / min or lower.

[0071] The preparation method provided by this invention involves holding the raw materials at a second temperature to allow all components to fully melt and form a homogeneous molten glass phase. The temperature is then raised to a third temperature and held thereafter. On the one hand, higher temperatures result in lower glass viscosity, which facilitates the removal of air bubbles from the molten glass. On the other hand, higher temperatures also increase the solubility of alumina in the molten glass. This material system has a high alumina content, and the high-temperature holding ensures the complete dissolution of the alumina component in the molten glass. The molten glass is then poured into a metal forming mold and rapidly cooled at room temperature. As the temperature of the molten glass decreases rapidly, the alumina precipitates in the glass matrix in the form of microcrystals due to the large amount of alumina present. With the decrease in temperature, the glass viscosity increases, and the diffusion rate required for alumina crystallization decreases rapidly. A large number of alumina tetrahedra in the molten glass do not have time to precipitate and remain in the glass network, forming a supersaturated solid solution. The glass brick, cooled to 800-1000°C, is then placed in an annealing furnace and cooled at a specific temperature to suppress the generation of large thermal stresses during the cooling process.

[0072] In the preparation method provided by this invention, the molten glass liquid with a high alumina concentration is rapidly cooled to 800~1000℃ at a third temperature. The solubility of alumina in the molten glass liquid decreases rapidly, and the alumina tends to precipitate from the glass liquid during the cooling process. Uniformly dispersed alumina crystals can be precipitated in the molten glass liquid. Moreover, due to the rapid cooling rate, the viscosity of the glass liquid increases rapidly, and the diffusion rate of the substance decreases rapidly, making it difficult for the precipitated alumina crystals to grow. The above process can obtain a microcrystalline glass material with fine alumina crystals dispersed in the matrix. The fine alumina crystals dispersed in the matrix can hinder the propagation of cracks in the glass matrix, thereby improving the impact resistance of the microcrystalline glass. Furthermore, during the rapid cooling process, a large number of alumina tetrahedra in the molten glass do not have time to precipitate and remain in the glass network. The volume of aluminum-oxygen tetrahedra is larger than that of silicon-oxygen tetrahedra, and the glass network structure contains a large number of large-sized aluminum-oxygen tetrahedra. This is beneficial for the subsequent KNO3 molten salt chemical strengthening process, where potassium ions in the molten salt exchange with sodium ions in the glass. This can form high compressive stress on the glass surface at a relatively low strengthening temperature, and at the same time, the stress diffusion layer has a high depth. Therefore, after strengthening, not only can the fine alumina crystals in the glass-ceramic hinder the propagation of cracks in the glass matrix, but the high numerical value and high depth of the compressive stress layer on the surface of the glass-ceramic can also inhibit the propagation of cracks on the glass surface. These two effects give the glass a very significant impact resistance.

[0073] In some preferred embodiments, the first temperature is 900~1000℃, such as 900℃, 910℃, 920℃, 930℃, 940℃, 950℃, 960℃, 970℃, 980℃, 990℃, 1000℃, etc.; the holding time at the first temperature is 1~4h, such as 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, etc.; the temperature is increased to the first temperature at a rate of 3~5℃ / min, such as 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min, 5℃ / min, etc.

[0074] In some preferred embodiments, the second temperature is 1350~1450℃, for example 1350℃, 1360℃, 1370℃, 1380℃, 1390℃, 1400℃, 1410℃, 1420℃, 1430℃, 1440℃, 1450℃, etc.; the holding time at the second temperature is 1~4h, for example 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, etc.; the temperature is increased to the second temperature at a rate of 2~5℃ / min, for example 2℃ / min, 2.5℃ / min, 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min, 5℃ / min, etc.

[0075] In some preferred embodiments, the third temperature is 1550~1650℃, for example 1550℃, 1560℃, 1570℃, 1580℃, 1590℃, 1600℃, 1610℃, 1620℃, 1630℃, 1640℃, 1650℃, etc.; the holding time at the third temperature is 1~8h, for example 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, etc.; the temperature is increased to the third temperature at a rate of 2~5℃ / min, for example 2℃ / min, 2.5℃ / min, 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min, 5℃ / min, etc.

[0076] In some preferred embodiments, the temperature is cooled to 800-1000°C (e.g., 800°C, 820°C, 850°C, 880°C, 900°C, 920°C, 950°C, 980°C, 1000°C, etc.) at a cooling rate of 100-300°C / min (e.g., 100°C / min, 120°C / min, 140°C / min, 160°C / min, 180°C / min, 200°C / min, 220°C / min, 240°C / min, 260°C / min, 280°C / min, 300°C / min, etc.).

[0077] In some preferred embodiments, the temperature is cooled to below 200°C at a cooling rate of 0.5~3°C / min (e.g., 0.5°C / min, 1°C / min, 1.5°C / min, 2°C / min, 2.5°C / min, 3°C / min, etc.).

[0078] In some preferred embodiments, the method further includes a step of chemically strengthening the microcrystalline glass; the chemical strengthening includes immersing the microcrystalline glass in potassium nitrate molten salt at 420~550℃ (e.g., 420℃, 450℃, 480℃, 500℃, 520℃, 550℃) for 1~16h (e.g., 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, etc.).

[0079] The performance indicators of the microcrystalline glass or microcrystalline glass products of this invention are tested using the following methods:

[0080] 1) HK hardness (Knoop hardness):

[0081] HK hardness is an important indicator for measuring the scratch resistance and abrasion resistance of glass-ceramics (including ion-exchange strengthened glass-ceramics). It is calculated by pressing a diamond indenter (long-ridged) into the material surface under a constant load and measuring the diagonal length of the indentation. The unit is GPa or kgf / mm². Formula:

[0082] HK=P / A p =14.229×P / d 2

[0083] P: Load (kgf);

[0084] d: Length of the long diagonal (mm);

[0085] A p : Projected area of ​​the indentation.

[0086] 2) 130g steel ball impact height test:

[0087] A microcrystalline glass product sample measuring 70×50mm and 0.6mm in thickness was placed on a glass bearing fixture. A 130g steel ball was dropped from a specified height. The maximum drop ball test height from which the sample could withstand the impact without breaking was determined. Specifically, the test was conducted starting from a drop ball test height of 400mm. Without breaking, the height was changed sequentially to 400mm, 500mm, 600mm, 700mm, and above, with each change at 100mm intervals. For the embodiment with a "drop ball test height," the microcrystalline glass product was used as the test object. In the embodiment, the test data recorded as 1600mm indicates that the sample withstood an impact of 1600mm without breaking. Breakage occurred when the test height was increased to 1700mm. Therefore, the drop ball test height was 1600mm.

[0088] 3) 5Kg steel ball impact height test:

[0089] A microcrystalline glass product sample with dimensions of 50×50mm and a thickness of 4mm was placed on a glass bearing fixture. A 130g steel ball was dropped from a specified height. The maximum drop ball test height from which the sample could withstand the impact without breaking was determined. Specifically, the test was conducted starting from a drop ball test height of 100mm. Without breaking, the height was changed sequentially to 150mm, 200mm, 250mm, 300mm, and above, with each change at 50mm intervals. For the embodiment with a "drop ball test height," the microcrystalline glass product was used as the test object. In the embodiment, the test data recorded as 200mm indicates that the sample withstood a 200mm impact without breaking. Breakage occurred when the test height was increased to 250mm; therefore, the drop ball test height was 200mm.

[0090] 4) Dual-ring test:

[0091] Equipment: ROR testing machine

[0092] Ensure the sample is free of defects such as cracks and notches that could affect its strength.

[0093] Use a stainless steel annular pressure head;

[0094] Test method:

[0095] Place the 60mm×60mm×6mm sample on the lower ring, adjust the product position to ensure its stability, and adjust the center lines of the upper and lower rings to be in the same position.

[0096] Compress the sample under the test conditions until it breaks, and record the maximum force and displacement at the time of breakage.

[0097] 5) Light transmittance test:

[0098] The light transmittance mentioned in this article refers to external transmittance, or simply transmittance.

[0099] The sample was processed to a thickness of 4mm and its opposing surfaces were polished parallel to each other to ensure that the test area was flat and free of defects such as scratches and bubbles. A transmittance meter was used for testing at a wavelength of 550nm. The equipment was calibrated before testing to ensure the accuracy of the results. The sample was placed in the testing instrument, the product was fixed, the test was started, and the results were recorded. The same product was tested three times, and the average value was calculated.

[0100] 6) Glass surface residual stress (CS) and glass surface stress layer depth (DOL) testing:

[0101] The surface compressive stress value CS and compressive stress depth DOL of each reinforced glass substrate were determined using an FSM-6000 glass surface stress tester.

[0102] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0103] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0104] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0105] The manufacturing process of glass-ceramics:

[0106] Weigh all the raw materials according to the formula, mix them evenly in a ball mill, put the evenly mixed raw materials into a glass melting furnace, heat them to 900-1000℃ at a rate of 3-5℃ / min and hold for 1-4 hours, then heat them to 1350-1450℃ at a rate of 2-5℃ / min and hold for 1-4 hours, then heat them to 1550-1650℃ at a rate of 2-5℃ / min and hold for 1-8 hours, then release the molten glass into the forming metal mold, and rapidly cool the molten glass to 800-1000℃ in the mold by air cooling or water cooling (cooling for 3-6 minutes), then put it into an annealing furnace and slowly cool it to 100-150℃ at a rate of 0.5-3℃ / min, then turn off the furnace and let it cool with the furnace. When the furnace temperature drops to room temperature, take out the glass bricks.

[0107] Chemical enhancement process:

[0108] After annealing, the glass bricks are cut, edged, and chamfered according to product specifications. After double-sided grinding, they are immersed in KNO3 molten salt at 420~550℃ for 1~16 hours for chemical strengthening. After the strengthened microcrystalline glass workpiece is cooled at room temperature, the surface is cleaned to obtain the product.

[0109] <Examples of Microcrystalline Glass>

[0110] Examples 1-5 are provided, in which microcrystalline glass with the composition shown in Table 1 is obtained by using the above-described microcrystalline glass manufacturing method, and the preparation process parameters are shown in Table 2.

[0111] Table 1 Chemical composition of glass-ceramics in Examples 1-5

[0112]

[0113] Table 2. Preparation process parameters of the microcrystalline glass in Examples 1-5

[0114]

[0115] The XRD pattern of the microcrystalline glass prepared in Example 1 before chemical strengthening is shown below. Figure 1 As shown, by Figure 1 It can be seen that alumina crystals are precipitated in the glass, that is, the precipitated phase of the glass-ceramic is alumina; the microstructure of the glass-ceramic prepared in Example 1 before chemical strengthening is shown in the figure below. Figure 2 As shown, by Figure 2 It can be seen that a large number of alumina nanocrystals with a diameter of less than 50 nm are uniformly dispersed in the glass matrix before strengthening. Analysis shows that the reason for preparing a glass-ceramic with a large number of dispersed alumina nanocrystals is that the raw materials are held at 1350~1450℃ to fully melt and form a homogeneous molten glass phase. Raising the temperature to 1550~1650℃ and holding it at this temperature serves two purposes: firstly, higher temperatures result in lower glass viscosity, which is beneficial for removing bubbles from the molten glass; secondly, higher temperatures increase the solubility of alumina in the molten glass. This material system has a high alumina content, and high-temperature holding ensures that the alumina component is completely dissolved in the molten glass. When the molten glass is poured into a metal forming mold and cooled at room temperature, the temperature of the molten glass drops rapidly. Because the molten glass contains a large amount of alumina, alumina precipitates in the glass matrix in the form of microcrystals. As the temperature decreases, the glass viscosity increases, and the diffusion rate of substances required for alumina crystallization decreases rapidly. A large number of alumina tetrahedra in the molten glass do not have time to precipitate and remain in the glass network, forming a supersaturated solid solution.

[0116] The properties of the microcrystalline glass prepared in each embodiment were determined by the testing method described in this invention. The properties before chemical strengthening are shown in Table 3, and the properties after chemical strengthening are shown in Table 4.

[0117] Table 3 Performance indicators of unchemically strengthened glass-ceramics prepared in Examples 1-5

[0118]

[0119] Table 4 Performance indicators of chemically strengthened glass-ceramics prepared in Examples 1-5

[0120]

[0121] Comparing the data in Tables 3 and 4, it can be seen that after conventional chemical strengthening, the optical properties of the glass-ceramic do not change significantly, but the HK hardness, impact resistance to low-mass and high-mass dropped balls, and double-ring test performance are all significantly improved. Furthermore, the residual stress on the glass surface reaches over 1300 MPa, and the stress layer depth on the glass surface reaches over 50 μm. Combined with... Figure 1 and Figure 2 The reasons for this phenomenon are as follows: Firstly, the microcrystalline glass contains a large number of uniformly dispersed nano-alumina crystal particles, which can hinder the propagation of cracks in the glass matrix. Secondly, during the rapid cooling process, a large number of alumina tetrahedra in the molten glass do not have time to precipitate and remain in the glass network. The volume of aluminum-oxygen tetrahedra is larger than that of silicon-oxygen tetrahedra. The glass network structure contains a large number of large-sized aluminum-oxygen tetrahedra, which is beneficial for the exchange of potassium ions in the molten salt with sodium ions in the glass during the subsequent KNO3 molten salt chemical strengthening process. This can form a high compressive stress on the glass surface at a lower strengthening temperature, and at the same time, the stress diffusion layer is deep. The high numerical and deep compressive stress layer on the surface of the microcrystalline glass can further inhibit the propagation of cracks on the glass surface. These two factors give the glass a very significant impact resistance.

[0122] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An impact-resistant optical microcrystalline glass, characterized in that, The material comprises, by mass percentage: 30-50% SiO2, 23-42% Al2O3, 4-12% Na2O, 4-12% CaO, 0.5-9% MgO, 0.5-5% ZrO2, 0.05-0.8% P2O5, and 0.05-0.5% Y2O3, wherein nano-alumina is dispersed in the impact-resistant optical microcrystalline glass.

2. The impact-resistant optical microcrystalline glass as described in claim 1, characterized in that, It contains: SiO2 36~46%; and / or Al2O3 25~40%; and / or Na2O 6~12%; and / or CaO 5~9%; and / or MgO 2~8%.

3. The impact-resistant optical microcrystalline glass as described in claim 1, characterized in that, The impact-resistant optical microcrystalline glass, by weight percentage, further comprises one or more of the following components: K2O 0~6%, Li2O 0~5%, Sb2O3 0~1.5%, SnO2 0~1.5%, La2O3 0~1%.

4. The impact-resistant optical microcrystalline glass as described in claim 3, characterized in that, It contains: ZrO2 1~5%; and / or K2O 0.5~4%; and / or Li2O 0~3%; and / or Sb2O3 0.05~1%; and / or SnO2 0.05~0.5%; and / or P2O5 0.05~0.7%; and / or Y2O3 0.05~0.4%; and / or La2O3 0.05~0.5%.

5. The impact-resistant optical microcrystalline glass as described in claim 4, characterized in that, It contains: ZrO2 1~4.5%; and / or K2O 0.5~3%; and / or Li2O 0.05~2.5%; and / or Sb2O3 0.1~0.5%; and / or SnO2 0.1~0.4%; and / or P2O5 0.05~0.6%; and / or Y2O3 0.05~0.3%; and / or La2O3 0.05~0.3%.

6. The impact-resistant optical microcrystalline glass according to any one of claims 1 to 5, characterized in that, The nano-alumina has a grain size of less than 50 nm; the nano-alumina is uniformly dispersed in the impact-resistant optical microcrystalline glass; the nano-precipitated phase of the microcrystalline glass is nano-alumina crystal.

7. The impact-resistant optical microcrystalline glass according to any one of claims 1 to 5, characterized in that, The transmittance of 4mm thick microcrystalline glass at a wavelength of 550nm is over 88%.

8. The impact-resistant optical microcrystalline glass according to any one of claims 1 to 5, characterized in that, The microcrystalline glass has one or more of the following characteristics: The surface stress layer depth of the microcrystalline glass is less than 100 μm; The surface residual stress of the microcrystalline glass is above 1200 MPa; With a thickness of 0.6mm, the impact resistance height relative to a 130g steel ball is over 1500mm; With a thickness of 4mm, the impact resistance height relative to a 5kg steel ball is over 300mm; The Knoop hardness value of the microcrystalline glass is above 3.5 GPa.

9. The impact-resistant optical microcrystalline glass as described in claim 8, characterized in that, The microcrystalline glass has one or more of the following characteristics: The surface stress layer depth of the microcrystalline glass is 50~100μm; The surface residual stress of the microcrystalline glass is above 1300 MPa; With a thickness of 0.6mm, the impact resistance height relative to a 130g steel ball is over 1700mm; With a thickness of 4mm, the impact resistance height relative to a 5kg steel ball is over 400mm; The Knoop hardness value of the microcrystalline glass is 4~6 GPa.

10. The impact-resistant optical microcrystalline glass according to any one of claims 1 to 5, characterized in that, Its preparation methods include: After mixing the raw materials according to the formula, the temperature is first raised to the first temperature and held, then raised to the second temperature and held, and then raised to the third temperature and held. The resulting molten glass is then cast and rapidly cooled to 800~1000℃ at a cooling rate of 100℃ / min or higher, and then cooled to below 200℃ at a cooling rate of 5℃ / min or lower.

11. The impact-resistant optical microcrystalline glass as described in claim 10, characterized in that, The first temperature is 900~1000℃; the holding time at the first temperature is 1~4h; the temperature is increased to the first temperature at a rate of 3~5℃ / min; The second temperature is 1350~1450℃; the holding time at the second temperature is 1~4h; the temperature is increased to the second temperature at a rate of 2~5℃ / min; The third temperature is 1550~1650℃; the holding time at the third temperature is 1~8h; and the temperature is increased to the third temperature at a rate of 2~5℃ / min. Cool to 800-1000℃ at a cooling rate of 100-300℃ / min; Cool to below 200°C at a cooling rate of 0.5~3°C / min.

12. The impact-resistant optical microcrystalline glass as described in claim 10, characterized in that, Also includes: The step of chemically strengthening the microcrystalline glass; The chemical strengthening includes immersing the microcrystalline glass in potassium nitrate molten salt at 420~550℃ for 1~16 hours.

13. A glass cover plate, characterized in that, Including the impact-resistant optical microcrystalline glass as described in any one of claims 1 to 12.

14. A glass component, characterized in that, It includes the impact-resistant optical microcrystalline glass according to any one of claims 1 to 12, and / or the glass cover plate according to claim 13.

15. A display device, characterized in that, It includes the impact-resistant optical microcrystalline glass according to any one of claims 1 to 12, and / or the glass cover plate according to claim 13, and / or the glass component according to claim 14.

16. An electronic device, characterized in that, It includes the impact-resistant optical microcrystalline glass according to any one of claims 1 to 12, and / or includes the glass cover plate according to claim 13, and / or the glass components according to claim 14; and / or the display device according to claim 15.

17. The method for preparing the impact-resistant optical microcrystalline glass according to any one of claims 1 to 9, characterized in that, include: After mixing the raw materials according to the formula, the temperature is first raised to the first temperature and held, then raised to the second temperature and held, and then raised to the third temperature and held. The resulting molten glass is then cast and rapidly cooled to 800~1000℃ at a cooling rate of 100℃ / min or higher, and then cooled to below 200℃ at a cooling rate of 5℃ / min or lower.

18. The method for preparing the impact-resistant optical microcrystalline glass as described in claim 17, characterized in that, The first temperature is 900~1000℃; the holding time at the first temperature is 1~4h; the temperature is increased to the first temperature at a rate of 3~5℃ / min; The second temperature is 1350~1450℃; the holding time at the second temperature is 1~4h; the temperature is increased to the second temperature at a rate of 2~5℃ / min; The third temperature is 1550~1650℃; the holding time at the third temperature is 1~8h; and the temperature is increased to the third temperature at a rate of 2~5℃ / min. Cool to 800-1000℃ at a cooling rate of 100-300℃ / min; Cool to below 200°C at a cooling rate of 0.5~3°C / min.

19. The method for preparing the impact-resistant optical microcrystalline glass as described in claim 17, characterized in that, Also includes: The step of chemically strengthening the microcrystalline glass; The chemical strengthening includes immersing the microcrystalline glass in potassium nitrate molten salt at 420~550℃ for 1~16 hours.

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