High-strength lithium-aluminum-silicon glass as well as preparation method and application thereof

Abstract

The invention relates to the technical field of glass manufacturing, in particular to high-strength lithium-aluminum-silicon glass as well as a preparation method and application thereof. According to the embodiment of the invention, the problem of non-uniform stress distribution caused by insufficient ion exchange in the prior art is effectively solved by accurately regulating and controlling the component system of the lithium aluminum silicon glass, optimizing the ion exchange dynamic process and establishing the optimal strengthening process parameters, and the spontaneous explosion risk caused by exceeding the critical stress in the strengthening process of the glass is remarkably reduced. The high-strength lithium aluminum silicon glass is prepared from the following raw material components in percentage by mass: 55 to 75 weight percent of SiO2, 14 to 32 weight percent of Al2O3, 0 to 8 weight percent of B2O3, 2 to 8 weight percent of Li2O, 3 to 16 weight percent of Na2O, 0 to 5 weight percent of K2O, 0 to 8 weight percent of MgO, 0 to 3.5 weight percent of ZnO, 0 to 2 weight percent of SrO, 0 to 15 weight percent of P2O5, 0 to 1 weight percent of ZrO2, 0.2 to 5 weight percent of TiO2, 0.8 to 1.5 weight percent of Y2O3 and 0.1 to 1.2 weight percent of clarifying agent, and the ratio of (ZrO2 + TiO2 + Y2O3) to P2O5 is 0.15 to 1.2.

Description

Technical Field

[0001] This invention relates to the field of glass manufacturing technology, and in particular to high-strength lithium aluminum silicon glass, its preparation method, and its applications. Background Technology

[0002] With the development of new display technologies towards innovation, diversification, and larger screens, and the widespread application of 5G communication technology, the market has placed more stringent demands on the mechanical strength, durability, and reliability of display panel materials. Among existing high-strength glass systems, lithium aluminum silicate glass, with its unique performance advantages, is gradually replacing traditional soda-lime silicate glass and high-alumina glass, becoming the representative material of third-generation high-strength glass substrates. This type of lithium aluminum silicate glass has a dense network structure and a high elastic modulus, making it particularly suitable for two-step or three-step chemical strengthening processes to obtain excellent mechanical properties. Li₂O, as a key component, plays a dual role in the glass structure: on the one hand, it provides smaller Li₂O ions for ion exchange. + Ions can synergistically enhance surface compressive stress and stress layer depth; on the other hand, they can significantly reduce the high-temperature viscosity of the glass melt and promote the full melting of high-content Al2O3. Currently, lithium aluminum silicon glass substrates of various specifications can be prepared through float glass or overflow processes, and after ion exchange strengthening, they are widely used in high-end fields such as cover plates for electronic information products, aircraft observation windows, and automotive displays.

[0003] However, existing technologies still have significant shortcomings: even after strengthening, the optical properties, mechanical strength, and drop resistance of traditional silicate glass still fall short of the demands of high-end electronic products; while mainstream high-alumina cover glass has been applied to mid-to-high-end smart devices, its overall performance still needs improvement. More critically, in the chemical strengthening process of lithium aluminum silicate glass, improper component ratios often lead to insufficient ion exchange, resulting in uneven stress distribution that may even exceed critical values, causing the risk of spontaneous glass breakage. Therefore, how to improve ion exchange efficiency through optimized glass component design, establish optimal strengthening process parameters, and eliminate stress distribution defects has become a core technical challenge that urgently needs to be addressed in the research and development of high-strength glass. Summary of the Invention

[0004] The purpose of this invention is to improve lithium aluminum silicate glass and its preparation method. The embodiments of this invention, through precise control of the composition system of the lithium aluminum silicate glass, optimization of the ion exchange kinetics, and establishment of optimal strengthening process parameters, effectively solve the problem of uneven stress distribution caused by insufficient ion exchange in existing technologies, and significantly reduce the risk of spontaneous breakage caused by the glass exceeding the critical stress during the strengthening process. This technical solution achieves a comprehensive improvement in the strengthening performance of glass through the synergistic effect of composition optimization and process improvement.

[0005] To solve the above technical problems, one of the purposes of the present application is to provide a high-strength lithium-aluminum-silicon glass, comprising the following raw material components in terms of mass percentage of oxides: 55-75wt% of SiO2, 14-32wt% of Al2O3, 0-8wt% of B2O3, 2-8wt% of Li2O, 3-16wt% of Na2O, 0-5wt% of K2O, 0-8wt% of MgO, 0-3.5wt% of ZnO, 0-2wt% of SrO, 0-15wt% of P2O5, 0-1wt% of ZrO2, 0.2-5wt% of TiO2, 0.8-1.5wt% of Y2O3, and 0.1-1.2wt% of a fining agent, wherein (ZrO2+TiO2+Y2O3) / P2O5 is 0.15-1.2.

[0006] According to a preferred embodiment, RO is the sum of mass percentages of MgO, ZnO and SrO in the glass composition, R2O is the sum of mass percentages of Na2O, K2O and Li2O, and RO / R2O is 0.1-0.8.

[0007] According to a preferred embodiment, Al2O3 / SiO2 is 0.236-0.342 in terms of mass.

[0008] According to a preferred embodiment, the high-strength lithium-aluminum-silicon glass has a potassium ion surface compressive stress (CS) of ≥950 Mpa and a sodium ion stress layer depth (Dol) of ≥110 μm.

[0009] One of the purposes of the present application is also to provide a preparation method of a lithium-aluminum-silicon glass, comprising the following steps: 55-75wt% of SiO2, 14-32wt% of Al2O3, 0-8wt% of B2O3, 2-8wt% of Li2O, 3-16wt% of Na2O, 0-5wt% of K2O, 0-8wt% of MgO, 0-3.5wt% of ZnO, 0-2wt% of SrO, 0-15wt% of P2O5, 0-1wt% of ZrO2, 0.2-5wt% of TiO2, and 0.8-1.5wt% of Y2O3 are mixed to form a batch, a fining agent of 0.1-1.2wt% is added for fining after melting, annealing is performed, and a glass sample is obtained; The glass sample is soaked in molten NaNO3, and is strengthened at a temperature in the range of 390-450℃.

[0010] According to a preferred embodiment, before strengthening, the glass sample is fixed as a 0.25-8 mm sheet-shaped glass sample based on a forming operation during annealing.

[0011] According to a preferred embodiment, the strengthening is divided into three times of strengthening using different molten salts, The molten salt for the first time of strengthening is selected from the group consisting of: 100wt% of NaNO3; 20~80wt% of NaNO3and 20~80wt% of KNO3; or 99.5~100wt% of NaNO3and 0~0.5wt% of LiNO3, The molten salt for the second time of strengthening is selected from the group consisting of: 100wt% of KNO3; or 0~10wt% of NaNO3and 90~100wt% of KNO3, The molten salt for the third time of strengthening is 100wt% of KNO3.

[0012] According to a preferred embodiment, the step of strengthening comprises: S1: immersing the glass sample in a molten salt with a composition of 20~80wt% of NaNO3and 20~80wt% of KNO3at a temperature range of 390℃~450℃; S2: immersing the glass sample after the first time of strengthening in a molten salt with a composition of 100wt% of KNO3at a temperature range of 390℃~450℃; S3: immersing the glass sample after the second time of strengthening in a molten salt with a composition of 100wt% of KNO3at a temperature range of 390℃~450℃.

[0013] According to a preferred embodiment, the melting temperature is 1530~1670℃; the temperature for refining is 1500~1580℃; and the temperature for annealing is 580~700℃.

[0014] Preferably, the step of strengthening comprises: S1: immersing the glass sample in a molten salt with a composition of 20~80wt% of NaNO3and 20~80wt% of KNO3at a temperature range of 390℃~450℃; S2: immersing the glass sample after the first time of strengthening in a molten salt with a composition of 100wt% of KNO3at a temperature range of 390℃~420℃; S3: immersing the glass sample after the second time of strengthening in a molten salt with a composition of 100wt% of KNO3at a temperature range of 390℃~420℃.

[0015] According to a preferred embodiment, the melting temperature is 1530~1670℃; the temperature for refining is 1500~1580℃; and the temperature for annealing is 580~700℃.

[0016] More preferably, the step of strengthening comprises: S1: immersing the glass sample in a molten salt at a temperature range of 440℃, the molten salt being configured as 20~80wt% of NaNO3 and 20~80wt% of KNO3; S2: immersing the once-strengthened glass sample in a molten salt at a temperature range of 410℃, the molten salt being configured as 100wt% of KNO3; S3: immersing the twice-strengthened glass sample in a molten salt at a temperature range of 410℃, the molten salt being configured as 100wt% of KNO3.

[0017] More preferably, the step of strengthening comprises: S1: immersing the glass sample in a molten salt at a temperature range of 390℃~450℃, the molten salt being configured as 40wt% of NaNO3 and 60wt% of KNO3; S2: immersing the once-strengthened glass sample in a molten salt at a temperature range of 390℃~420℃, the molten salt being configured as 100wt% of KNO3; S3: immersing the twice-strengthened glass sample in a molten salt at a temperature range of 390℃~420℃, the molten salt being configured as 100wt% of KNO3.

[0018] More preferably, the treatment time of S1 is 100 min. The treatment time of S2 is 60 min. The treatment time of S3 is 20 min.

[0019] According to a preferred embodiment, the melting temperature is 1530~1670℃; the refining temperature is 1500~1580℃; and the annealing temperature is 580~700℃.

[0020] According to a preferred embodiment, the sandpaper drop ball impact height of the lithium-aluminum-silicate glass is not less than 80 cm. Due to the uniform distribution of the strengthening stress of the lithium-aluminum-silicate glass, the shape of the glass after the drop ball impact is blocky.

[0021] According to a preferred embodiment, the Vickers hardness of the lithium-aluminum-silicate glass is ≥650 kgf / mm2 before strengthening. The Vickers hardness of the lithium-aluminum-silicate glass is not less than 720 kgf / mm2 after the third strengthening.

[0022] According to a preferred embodiment, the transmittance of the lithium-aluminum-silicate glass is ≥91 at a visible light wavelength of 550 nm.

[0023] According to a preferred embodiment, the expansion coefficient of the lithium-aluminum-silicate glass is 70×10 -7 ~80×10 -7 / ℃.

[0024] According to a preferred embodiment, the lithium aluminum silicon glass has a scratch first end and end width of 17.54-28.57 μm under a load of 1 kg. The lithium aluminum silicon glass has a limit scratch negative of not less than 3 kg under a load of 1 kg.

[0025] One of the purposes of the present application is also to provide the use of the lithium aluminum silicon glass in the smart device cover plate, wherein the lithium aluminum silicon glass is the high-strength lithium aluminum silicon glass described above or the lithium aluminum silicon glass prepared based on the preparation method described above.

[0026] Preferably, the lithium aluminum silicon glass for the smart device cover plate comprises 55-75 wt% of SiO2, 14-32 wt% of Al2O3, 0-8 wt% of B2O3, 2-8 wt% of Li2O, 3-16 wt% of Na2O, 0-5 wt% of K2O, 0-8 wt% of MgO, 0-3.5 wt% of ZnO, 0-2 wt% of SrO, 0-15 wt% of P2O5, 0-1 wt% of ZrO2, 0.2-5 wt% of TiO2, 0.8-1.5 wt% of Y2O3, and 0.1-1.2 wt% of a fining agent, wherein (ZrO2+TiO2+Y2O3) / P2O5 is 0.15-1.2.

[0027] According to a preferred embodiment, the preparation method of the lithium aluminum silicon glass for the smart device cover plate use comprises: ion exchange first strengthening temperature 440℃, treatment time 70-120 min; secondary strengthening temperature 410℃, treatment time 60-90 min; third strengthening temperature 410℃, treatment time 10-20 min.

[0028] Preferably, the preparation method of the lithium aluminum silicon glass for the smart device cover plate use comprises: ion exchange first strengthening temperature 440℃, treatment time 100 min; secondary strengthening temperature 410℃, treatment time 60 min; third strengthening temperature 410℃, treatment time 20 min.

[0029] The beneficial effects of the present technical solution are: The present application realizes the improvement of multiple technical effects by precisely regulating the component system of the lithium aluminum silicon glass. All components and their content ranges are based on systematic optimization design, and the synergistic effect is significant. The specific effects are reflected in the following aspects: The present application limits the SiO2 content to 55-75 wt%, which is both a builder of the three-dimensional skeleton of the glass and a silicon oxygen tetrahedron (SiO2) 4- which is the basic unit, endows the glass with excellent chemical stability, thermal stability, transparency, high softening temperature, hardness and mechanical strength; at the same time, with (AlO3) 5-The generation of alumina-silica anion groups provides structural support for subsequent chemical strengthening. If the SiO2 is too low, the thermal expansion coefficient increases, the scratch resistance decreases, the glass transition temperature decreases, and the strengthening effect is also affected; if the SiO2 is too high, other components are diluted, in addition to the sudden increase in melt viscosity, melting is difficult, and the overall performance will also be unpredictably degraded due to the imbalance of the ratio.

[0030] Al2O3 is preferably 14-32wt%. Al 3+ The coordination number can vary, and in the network, (AlO4) 4- or (AlO6) 8- exists; in the form of (AlO3) 5 under the action of R2O or RO, its molar volume is about 41 cm³ / mol, which is larger than that of (SiO2) 4 27.24 cm³ / mol, thus expanding the network gap and promoting ion diffusion. High content brings about crystallization inhibition and high temperature viscosity increase, making the glass have both ion exchange ability and producibility, retaining the intrinsic advantages and laying a foundation for subsequent deep processing.

[0031] Technically, in order to balance the complex system of lithium-aluminum-silicon glass and excellent bending resistance, the mass ratio of Al2O3 / SiO2 must be precisely in the range of 0.236-0.342, and deviation from this range will significantly weaken the bending strength.

[0032] Alkali metal oxides R2O (Na2O, K2O, Li2O) are outside the network and are also the core of chemical strengthening. They lower the melting temperature, and excessive amounts weaken water resistance and reduce surface compressive stress. When the total alkali amount is fixed, adjusting the ratio of any two alkalis will cause mixed alkali effect, and the mechanical properties will be enhanced; at the same time, the presence of Na2O and Li2O can realize two-step ion exchange, and the glass with better impact resistance can be obtained.

[0033] Li2O, Na2O, K2O lower the melting point, and Li2O reacts with SiO2 to form silicate at low temperature, acting as a strong flux; excessive R2O also weakens water resistance and surface compressive stress. Therefore, the total amount of R2O needs to be controlled within a reasonable range, and Na2O and Li2O need to coexist to support two-step ion exchange, and finally obtain high strength, high hardness, and high impact resistance.

[0034] Alkaline earth metal oxides RO (CaO, MgO) are fluxing, but excessive content shortens the workability, induces crystallization; CaO especially hinders ion exchange, easily causing molten salt "poisoning"; MgO improves chemical stability and mechanical properties, and has a fluxing effect at high temperature, but excessive amounts promote crystallization and increase the difficulty of forming, so it is usually less than 12wt%.

[0035] SnO2 does not interfere with melting and forming, and is crucial for the stability of the float process; as a transparent conductive material, it improves the chemical stability and transmittance of the glass.

[0036] Y2O3 and SiO2 are complementary: SiO2 forms the skeleton, and Y2O3 fills the gaps and homogenizes the structure. Studies have shown that Y2O3 weakens the SiO2 network connection, increases non-bridge oxygen, and improves atomic packing density; in cooperation with Al2O3, Al2O3 raises the temperature resistance to above 300℃, and Y 3+ High field strength further improves chemical stability. Y2O3 can also reduce high-temperature viscosity and melting temperature. When the addition is ≥1wt%, the clarification temperature decreases by 6-20℃, improving efficiency and reducing energy consumption. The optimal addition amount is 0.3-0.5wt%.

[0037] ZrO2 is wear-resistant, heat-resistant, corrosion-resistant, and oxidation-resistant, and can be used as a network former to significantly improve strength, thermal stability, and alkali resistance. Zr 4+ ZrO2 exists as [ZrO6] octahedrons, with strong Zr–O–Si bonds that are difficult to break, which can improve fracture properties and reduce the risk of fracture; however, ZrO2 is difficult to melt, and excessive introduction increases melting difficulty and promotes crystallization, which is not conducive to performance.

[0038] B2O3 is a network former that reduces viscosity at high temperatures with [BO3] triangles, and at low temperatures, it takes free oxygen to form [BO4] tetrahedrons, making the structure dense and improving chemical, thermal stability, and mechanical strength; excessive amounts reduce Young's modulus and acid resistance, and the dense network hinders ion migration, resulting in a sharp decrease in ion exchange capacity, so the content is limited to 0-3.5wt%.

[0039] SrO is an external network former that can improve chemical stability, accelerate melting, and reduce liquidus temperature, and appropriate addition can improve hardness and fracture resistance; however, excessive amounts can worsen clarification and increase density, so it is controlled at 0-2wt%.

[0040] P2O5 forms a layered network with [PO4] tetrahedrons, promotes ion exchange, and has damage resistance; excessive amounts weaken surface chemical stability and exacerbate devitrification, so the content is limited to 1.5-14wt%.

[0041] By precisely combining the above components, the present application obtains a lithium aluminum silicon glass with excellent comprehensive performance, and the strengthening effect is improved, which can be used as a smart terminal cover plate. The clarifier is 0.1-1.2wt%; RO is the sum of MgO+ZnO+SrO, and R2O is 8-18.5wt% (one or more of Li, Na, and K). The optimized formula ensures stability while promoting ion exchange by adjusting the components to form a thicker composite compressive stress layer, thereby improving strength, surface compressive stress, bending resistance, and drop resistance.

[0042] Preparation method: raw materials, glass powder and clarifying agent are mixed, melted, clarified, annealed, cut, ground, polished, CNC, washed, once strengthened, twice strengthened, and optionally thrice strengthened to complete the preparation of lithium-aluminum-silicon glass. Different salt bath combinations of NaNO3, KNO3 and LiNO3 are used to increase the surface DOL and make the CS peak close to the surface through small ion and large ion exchange, thereby significantly improving the impact resistance and drop resistance.

[0043] The obtained glass has greater surface compressive stress and deeper stress layer, and the optical, electrical, mechanical, impact resistance and drop resistance are comprehensively improved, and the sandpaper ball impact height is greater than or equal to 120 cm.

[0044] ZrO2, TiO2 and Y2O3 are high-field network modification oxides, which improve the mechanical strength and chemical stability; P2O5 is a network intermediate, and an excess amount reduces the density. If the synergistic ratio of the high-field oxides and P2O5 is less than 0.15, the network is unstable, and if the ratio is higher than 1.2, the network is prone to crystallization. RO (MgO+ZnO+SrO) enhances impact resistance, and R2O (Li2O+Na2O+K2O) affects the melting property; if the ratio of RO / R2O is less than 0.1, the glass is brittle, and if the ratio is higher than 0.8, the thermal stability decreases (in coordination with R2O in the range of 8-18.5wt%). DETAILED DESCRIPTION

[0045] The following examples are given to further illustrate the present application, but should not be construed as limiting the scope of the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present application shall still belong to the protection scope of the present application.

[0046] The performance indicators involved in the embodiments of the present application are explained as follows: CS is K + Surface compressive stress, unit: MPa; Dol is Na + Stress layer depth of layer, unit: μm; Dol-K is K + Stress layer depth of layer, unit: μm.

[0047] In the embodiments of the present application, the light transmittance is tested by using a spectrophotometer according to the standard ISO13468-1:1996, the thermal expansion coefficient is tested by using a STD dilatometer according to the standard GB / T 16920-2015, the expansion amount is tested by using a two-dimensional measuring instrument, the scratch resistance is tested by using a scratch resistance tester according to the standard ISO12137-2:1997, and the surface stress is tested by using a surface stress tester according to the standards GB / T 18144-2008 and ASTM 1422C-99.

[0048] Drop is the anti-drop resistance test, unit is cm. The mobile phone controlled drop tester GP-2112 is used, the parameter rising and falling speed is 350 m / s, and the specific test method is as follows: the sample with a size of 148*68*0.55 mm is simulated to have a real machine weight, the base height is 500 mm, the gradient is gradually increased by 100 mm, 1 time per height, glass + fixture = 213 g, and dropped on 80 mesh sandpaper.

[0049] Glass sandpaper ball drop test, unit is cm. The specific test method is as follows: 1) the sandpaper is placed on a marble platform, and the four edges are fixed by using a textured paper tape; 2) the battery cover appearance is placed downward, the position of the battery cover is adjusted, and the ball drop position is located at the center position of the battery cover; 3) the acrylic plate (thickness 6 mm) is placed; 4) the ball drop point position is located in the middle position of the acrylic plate; 5) the sandpaper is 180 mesh, the ball drop weight is 130 g, and the base height is 20 cm to start the test, and each test is increased by 5 cm until the glass is broken. The stress distribution is uniform, and the form after the ball drop impact is blocky. Otherwise, if small particles are generated after the sandpaper ball drop impact, and the glass does not stop exploding for about 1 minute after the impact.

[0050] 4Pb is the anti-4-point bending ability test, unit is MPa. The specific test method is as follows: the upper span is 20 mm, the lower span is 40 mm, the falling speed is 10 mm / min, until the product is broken, and the 4PB value at the time of breaking is recorded.

[0051] In the present application, wt% is the definition of wt% in the conventional sense, that is, the abbreviation of weight percent, indicating the mass proportion of a component in a mixture or solution.

[0052] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and not used to limit the scope of the present application. In addition, it should be understood that after reading the content taught by the present application, those skilled in the art can make various modifications or modifications to the present application, and these equivalent forms also fall within the scope defined by the claims attached to the present application.

[0053] The test method and test equipment in this paper are the commonly used methods for evaluating the related properties of glass in the industry, which is only a means to represent or evaluate the technical scheme and technical effect of the present application, and other test methods and test equipment can also be used, which does not affect the final result.

[0054] The lithium aluminum silicon glass provided by the present application, the preparation method thereof and the strengthened lithium aluminum silicon glass and the preparation method thereof will be specifically described below in conjunction with specific examples.

[0055] The application discloses a chemical strengthening method of lithium-aluminum-silicon glass, which comprises the following raw material components in percentage of mass of oxide: 55-75wt% of SiO2, 14-32wt% of Al2O3, 0-8wt% of B2O3, 2-8wt% of Li2O, 3-16wt% of Na2O, 0-5wt% of K2O, 0-8wt% of MgO, 0-3.5wt% of ZnO, 0-2wt% of SrO, 0-15wt% of P2O5, 0-1wt% of ZrO2, 0.2-5wt% of TiO2, 0.8-1.5wt% of Y2O3, and 0.1-1.2wt% of clarifying agent, wherein RO is the sum of mass percentages of MgO, ZnO and SrO in the glass composition, R2O is the sum of Na2O, K2O and / or Li2O, and RO / R2O is 0.1-0.8.

[0056] The application provides a preparation method of lithium-aluminum-silicon glass, which comprises the following steps: The following raw material components in percentage of mass of oxide are prepared: 55-75wt% of SiO2, 14-32wt% of Al2O3, 0-8wt% of B2O3, 2-8wt% of Li2O, 3-16wt% of Na2O, 0-5wt% of K2O, 0-8wt% of MgO, 0-3.5wt% of ZnO, 0-2wt% of SrO, 0-15wt% of P2O5, 0-1wt% of ZrO2, 0.2-5wt% of TiO2, 0.8-1.5wt% of Y2O3, and 0.1-1.2wt% of clarifying agent; the glass sample is obtained by batching, melting, clarifying, homogenizing, forming, annealing, and polishing, cleaning and CNC processing, etc.

[0057] The glass sample is made into a sample with specifications of 148*68*0.55mm, and is subjected to first strengthening, and the selected strengthening molten salt is: ① 100wt% of NaNO3; ② 20-80wt% of NaNO3 and 20-80wt% of KNO3; and ③ 100wt% of NaNO3 and 0-0.5wt% of LiNO3; the first strengthening temperature is 390-450 DEG C, and the time is 60-300 min.

[0058] The sample after the first strengthening is subjected to second strengthening, and the selected strengthening molten salt is: ① 100wt% of KNO3; and ② 0-10wt% of NaNO3 and 90-100wt% of KNO3; the second strengthening temperature is 390-420 DEG C, and the time is 30-150 min.

[0059] The sample after the second strengthening is subjected to three times of strengthening, and the selected strengthening molten salt is 100wt% KNO3.

[0060] Specifically, the composition of each component is shown in Tables 1-4, and 40 groups of different raw material chemical compositions of glass are set. At the same time, the 40 groups of different component glasses are divided into four groups, and the strengthening processes of each group are different.

[0061] The lithium aluminum silicon glass provided by the application, the preparation method thereof, the strengthened lithium aluminum silicon glass and the preparation method thereof are specifically described in combination with the following groups of specific examples.

[0062] The application provides a lithium aluminum silicon glass and a preparation method thereof. By adjusting the components of the lithium aluminum silicon glass, when the glass is chemically strengthened, the stability and other performances of the glass are ensured, and under the condition that the stability and other performances of the glass are not affected, ion exchange is promoted by adjusting the components of the lithium aluminum silicon glass, a thicker compound compressive stress layer is formed on the surface of the glass, the sandpaper drop ball impact performance of the glass is improved, the glass form is better judged through sandpaper drop ball testing, and the risk of glass self-explosion is eliminated.

[0063] Table 1

[0064] As shown in Table 1, group 6 (SiO2 is 62.49wt%; Al2O3 is 19.51wt%; Li2O is 4.25wt%; Na2O is 6.97wt%; K2O is 1.43wt%; MgO is 2.65wt%; ZrO2 is 2.56wt%; TiO2 is 0.14wt%; Y2O3 is 0.00wt%; and the fining agent is 0.20wt%) shows a relatively significant and balanced effect under the condition of only one time and two times of strengthening.

[0065] Table 2

[0066] Table 3

[0067] Table 4

[0068] According to the exploration of the actual quality parameters of the 40 groups of glasses with different process steps and component ratios, ion exchange is promoted by adjusting the components of the lithium aluminum silicon glass, the optimal strengthening process layout is arranged, stress distribution is uniform in the strengthening process of the glass, the critical point is not exceeded, and the risk of self-explosion is eliminated. In the preparation, the following conditions are strictly controlled: 1) Al2O3 / SiO2 mass ratio is controlled in (0.236~0.342); 2) Y2O3 is optimal for 0.3~0.5wt%; 3) TiO2 is optimal for 0.2~1wt%.

[0069] After the secondary (or tertiary) strengthening process, the lithium aluminum silicon glass prepared has greater surface compressive stress and deeper compressive stress layer, thus has more excellent optical performance, electrical performance, mechanical performance, impact resistance and drop resistance. The lithium aluminum silicate glass is in the form of block after sandpaper ball impact test, and is better suitable for various display protective glasses.

[0070] It should be noted that the above specific embodiments are exemplary, and those skilled in the art can think of various solutions under the inspiration of the disclosure of the present application, and these solutions also belong to the disclosed range of the present application and fall within the protection scope of the present application. Those skilled in the art should understand that the present application is illustrative and does not constitute a limitation on the claims. The protection scope of the present application is defined by the claims and their equivalents.

Claims

1. A high-strength lithium aluminosilicate glass, characterized in that, The raw material components include the following in terms of mass percentage of oxide: 55-75wt% SiO2, 14-32wt% Al2O3, 0-8wt% B2O3, 2-8wt% Li2O, 3-16wt% Na2O, 0-5wt% K2O, 0-8wt% MgO, 0-3.5wt% ZnO, 0-2wt% SrO, 0-15wt% P2O5, 0-1wt% ZrO2, 0.2-5wt% TiO2, 0.8-1.5wt% Y2O3, and 0.1-1.2wt% fining agent, wherein, (ZrO2+TiO2+Y2O3) / P2O5 is 0.15-1.

2.

2. The high-strength lithium aluminosilicate glass according to claim 1, wherein, RO is the sum of mass percentage of MgO, ZnO and SrO in the glass composition, R2O is the sum of mass percentage of Na2O, K2O and Li2O, and the RO / R2O is 0.1-0.

8.

3. The high-strength lithium aluminosilicate glass according to claim 1, wherein, The Al2O3 / SiO2 is 0.236-0.342 in mass.

4. The high-strength lithium aluminosilicate glass according to claim 1, wherein, The high-strength lithium-aluminum-silicon glass has a potassium ion surface compressive stress of ≥950 MPa and a sodium ion stress layer depth of ≥110 μm.

5. A method of making a lithium aluminosilicate glass, characterized by, The method comprises the following steps: 55-75wt% SiO2, 14-32wt% Al2O3, 0-8wt% B2O3, 2-8wt% Li2O, 3-16wt% Na2O, 0-5wt% K2O, 0-8wt% MgO, 0-3.5wt% ZnO, 0-2wt% SrO, 0-15wt% P2O5, 0-1wt% ZrO2, 0.2-5wt% TiO2, and 0.8-1.5wt% Y2O3 are mixed to form a batch, and after melting, 0.1-1.2wt% fining agent is added for fining, annealing, and obtaining a glass sample; The glass sample is soaked in molten salt NaNO3 and strengthened at a temperature of 390-450°C.

6. The method of claim 5, wherein the lithium aluminosilicate glass is prepared by the steps of: melting a batch of lithium aluminosilicate glass; and forming the lithium aluminosilicate glass into a desired shape. The strengthening is divided into three times of strengthening using different molten salts, The molten salt for the first time of strengthening is selected from the following group: 100wt% NaNO3; 20-80wt% NaNO3 and 20-80wt% KNO3; or 99.5-100wt% NaNO3 and 0-0.5wt% LiNO3, The molten salt for the second time of strengthening is selected from the following group: 100wt% KNO3; or 0-10wt% NaNO3 and 90-100wt% KNO3, The molten salt for the third time of strengthening is 100wt% KNO3.

7. The method of making lithium aluminosilicate glass according to claim 5, wherein The steps of the strengthening include: S1 the glass sample is soaked in molten salt at a temperature of 390-450°C, and the molten salt is configured as 20-80wt% NaNO3 and 20-80wt% KNO3; S2 the glass sample after the first time of strengthening is soaked in molten salt at a temperature of 390-450°C, and the molten salt is configured as 100wt% KNO3; S3 immerses the secondary strengthened glass sample in a molten salt at a temperature range of 390-450℃, and the molten salt is configured as 100wt% KNO3.

8. The method of making lithium aluminosilicate glass according to claim 5, wherein, The melting temperature is 1530-1670℃; the clearing temperature is 1500-1580℃; and the annealing temperature is 580-700℃.

9. Use of lithium-aluminum-silicon glass for the production of a cover sheet for a smart device, characterized in that The lithium-aluminum-silicon glass is the high-strength lithium-aluminum-silicon glass as claimed in any one of claims 1-4 or the lithium-aluminum-silicon glass prepared based on the preparation method as claimed in any one of claims 5-8.

10. Use according to claim 9, characterized in that, The lithium-aluminum-silicon glass has a potassium ion surface compressive stress of ≥950 Mpa and a sodium ion stress layer depth of ≥110 μm.

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