High-aluminum glass and preparation method thereof

Abstract

The invention belongs to the technical field of glass manufacturing, and particularly relates to high-aluminum glass and a preparation method thereof. The high-temperature-resistant ceramic material is prepared from the following raw material components in percentage by mass: 60.0% to 70.0% of SiO2, 10.0% to 20.0% of Al2O3, 3.0% to 6.0% of Na2O, 2.0% to 5.0% of K2O, 0.0% to 4.0% of Li2O, 1.0% to 5.0% of CaO, 0.5% to 4.0% of MgO, 1.0% to 4.0% of ZrO2, 0.5% to 3.0% of TiO2, 1.0% to 3.0% of Y2O3 and 0.5% to 1.0% of B2O3. According to the high-alumina glass and the preparation method thereof, the dosage of each component of the high-alumina glass is adjusted, so that the high-alumina glass is excellent in mechanical property, the surface compression stress (CS value) is greater than or equal to 1000MPa, the stress layer depth (DOL) is greater than or equal to 100mu m, and meanwhile, the high-alumina glass has excellent properties of high hardness, high light transmittance, scratch resistance, drop resistance, high stability and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of glass manufacturing, and particularly relates to a high-aluminum glass and a preparation method thereof. BACKGROUND

[0002] The high-aluminum glass is widely applied to the fields of touch screen cover plates, display devices, military industry and the like due to excellent mechanical properties, chemical stability and optical properties. Most of the screens of smart phones on the market adopt high-aluminum glass, which has improved mechanical properties compared with ordinary glass, but still cannot meet the high-strength and high-hardness requirements of future development of mobile terminals, and ordinary soda-lime glass cannot meet the required properties, and even after chemical strengthening, the properties are difficult to be improved. As a protective cover plate glass, it needs to meet the properties of thickness and transparency when contacting with the outside world, and also needs to meet the properties of high strength, high transmittance, pressure resistance, scratch resistance, impact resistance and chemical stability.

[0003] The mechanical properties of traditional glass are mainly limited by its composition and surface micro-cracks. The low hardness leads to easy scratching by hard objects such as keys and sand in daily use, affecting the display clarity and appearance. More seriously, when the device is accidentally dropped, the glass cover plate needs to bear a large impact stress, and the traditional glass is prone to breakage due to insufficient toughness, resulting in functional failure. In addition, consumers' requirements for screen visual effects are increasing, and the cover plate glass needs to have extremely high light transmittance to ensure the true restoration of color and the brightness of display. At the same time, in daily use, the cover plate glass will frequently contact with sweat, cosmetics, cleaning agents and other chemicals, and therefore excellent chemical stability is also the key to ensure the long-term stability of appearance and performance.

[0004] Therefore, it is of great significance to develop a high-aluminum glass with high strength, high transmittance, high impact resistance and high stability through component synergistic design and under an industrialized preparation process. SUMMARY

[0005] In view of the above problems, the application provides a high-aluminum glass and a preparation method thereof, which are used to solve the problem that the existing high-aluminum glass cannot obtain a glass with high hardness, high light transmittance, scratch resistance, drop resistance and high stability at the same time.

[0006] To achieve the above purpose, the technical scheme adopted by the application is as follows:

[0007] In one aspect of the present application, a high-alumina glass is provided, the raw material components of which, in mass percentage, comprise SiO2 60.0-70.0%, Al2O3 10.0-20.0%, Na2O 3.0-6.0%, K2O 2.0-5.0%, Li2O 0.0-4.0%, CaO 1.0-5.0%, MgO 0.5-4.0%, ZrO2 1.0-4.0%, TiO2 0.5-3.0%, Y2O3 1.0-3.0%, and B2O3 0.5-1.0%.

[0008] Further, the mass ratio of CaO to MgO is 1:0.8-1.5.

[0009] Further, the mass ratio of Y2O3 to B2O3 is 2-3.

[0010] Further, the high-alumina glass has a thickness of 0.5-2 mm.

[0011] The present application provides a high-alumina glass, and the composition of each component of the high-alumina glass is described as follows.

[0012] SiO2 is an essential component of the glass framework, which can improve the strength, chemical stability and the like of the glass, and can make the glass have a lower thermal expansion coefficient. When the content of SiO2 is too low, the main network structure of the glass is poor, the mechanical properties are not good, and the weather resistance is poor; when the content of SiO2 is too high, the network connection of the glass is reduced, thereby reducing the viscosity and melting temperature of the glass, and it is difficult to effectively perform the tempering treatment of the glass, because the structure is stable and ion migration is difficult, and it is difficult to form the required surface pressure layer. Therefore, the content of SiO2 is controlled to be 60.0-70.0%.

[0013] Al2O3 is a main component for improving the ion exchange performance of the glass, which can reduce the crystallization tendency of the glass, and is a main component for improving the chemical stability, mechanical strength and elastic modulus of the glass. In the microstructure of the glass, alumina is a network intermediate oxide between the network former and the network extender. The volume of the aluminum-oxygen tetrahedron formed by Al2O3 in the glass is larger than that of the silicon-oxygen tetrahedron, which will cause the expansion of the glass volume, thereby reducing the density of the glass, providing an exchange channel for the glass in the ion exchange process, improving the depth of the compressive stress layer of the glass, and the high Al2O3 concentration glass has a high strain point temperature, so that the glass can maintain a high compressive stress layer stress after ion exchange. Therefore, the content of Al2O3 is controlled to be 10.0-20.0%.

[0014] Na2O is one of the necessary components for ion exchange, and when the glass contains sufficient Na2O, a large amount of Na+ can be provided to the glass, which can be exchanged with K+ in the molten salt to form a compressive stress layer on the surface of the glass. + K+ in the molten salt can be exchanged with Na+ in the glass to form a compressive stress layer on the surface of the glass. +Ion exchange is performed to form high compressive stress on the surface of the glass. Meanwhile, Na2O can provide a large amount of free oxygen to destroy the Si-O bond of the silicon-oxygen network, reduce the viscosity and melting temperature of the glass. K2O is a component for promoting ion exchange, and in alkali metal oxides, it is a component with a high effect of increasing the thickness of the compressive stress layer. Li2O is one of the main components for ion exchange, and can effectively reduce the viscosity of the glass and reduce the melting temperature of the glass. Li + The ionic radius of Li is small, so it can fill the gaps inside the glass body and balance the free oxygen. In the mixed molten salt of NaNO3 and KNO3 used in the present application, the Li + in the glass and Na + performs ion exchange with the Na 4+ in the molten salt, can quickly obtain a high compressive stress layer depth, and make the glass obtain good compression resistance and impact resistance and other properties. K2O, Na2O and Li2O belong to alkali metal oxides, can increase the ion exchange speed and deepen the compressive stress layer, and can play a role in network breaking, reducing the viscosity and melting temperature of the glass. Therefore, the content of Na2O, K2O and Li2O is controlled to be 3.0-6.0%, 2.0-5.0% and 0.0-4.0% respectively, and the content of Na2O, K2O and Li2O is 8.0-12.0%.

[0015] CaO can enhance the chemical stability and mechanical strength of the glass, and excessive introduction can easily cause glass crystallization and reduce stability. At high temperature, the presence of CaO can reduce the viscosity of the glass, which is beneficial to clarification. MgO is a network outer component of the glass, which can reduce the melting temperature of the glass and is a good fluxing agent, which can improve the chemical stability of the glass. CaO and MgO can enhance the stability and mechanical strength of the glass when used together, but the amount ratio of the two must be strictly controlled. Therefore, the content of CaO and MgO is controlled to be 1.0-5.0% and 0.5-4.0% respectively.

[0016] ZrO2 helps to reduce the grain size during crystallization, thereby improving the transmittance, chemical stability and ion exchange performance of the glass, and increasing the surface hardness of the glass, so that the glass is more resistant to scratching and dropping. However, excessive ZrO2 can significantly increase the melting temperature of the glass, and at the same time, can bring defects such as stones, which is not conducive to production. Therefore, the content of ZrO2 is controlled to be 1.0-4.0%.

[0017] TiO2 as a fluxing agent can increase the transparency, brightness and tensile properties of the glass, and Ti 4+When ions enter the glass network, they can break the Si-O-Si or Al-O-Al bonds in the glass and form stronger Ti-O bonds with the oxygen ions. This stronger bonding makes the glass network structure less deformable when heated, significantly reducing the coefficient of thermal expansion of the glass. The introduction of TiO2 enhances the density of the glass network. Ti 4+ Ions can fill the network gaps, making the glass structure more robust, effectively resisting the erosion of water, acid, alkali and other substances. The appropriate amount of TiO2 can also reduce the high temperature viscosity of high aluminum glass, making it easier to melt and clarify, and to some extent improving the process performance. Therefore, the content of TiO2 is controlled to be 0.5-3.0%.

[0018] B2O3 is also a glass forming oxide, which exists in the form of boron oxygen triangle [BO3] and boron oxygen tetrahedron [BO4] in the glass, has the effect of reducing high temperature viscosity and density, and has the effect of stabilizing the glass, making the crystallization difficult to precipitate, and reducing the liquidus temperature. B2O3 can also accelerate the dissolution and clarification of glass. B2O3 also cooperates with Y2O3, and the ratio of the two must be strictly controlled. Therefore, the content of B2O3 is controlled to be 0.5-1.0%.

[0019] Y2O3 is a high-performance additive in glass. The introduction of Y2O3 into the glass network (usually as an external network oxide) can "strengthen" the glass structure, making it more difficult to be eroded by water, acid, alkali and other media. Strong Y-O bond increases the difficulty of atomic movement and rearrangement, thereby increasing the temperature (Tg) required for the glass to change from solid to supercooled liquid, which makes the glass more able to maintain its shape and performance at high temperature. Y2O3 can expand the glass forming range and interact with B2O3 to affect the structure. Y2O3 can act as a modifier for the conversion of "boron oxygen triangle [BO3]" to "boron oxygen tetrahedron [BO4]", changing the ratio of [BO3] / [BO4] and thus adjusting the coefficient of thermal expansion and chemical stability. As an external network oxide, Y2O3 can also provide free oxygen, promote the dissolution of Al 3+ In the form of [AlO4], thereby strengthening the silicon oxygen network. At the same time, Y 3+ And Al 3+ Both can occupy the network gap, play the role of "filling" and "pinning", make the glass structure more dense and firm, synergistically enhance the glass network, and significantly improve the chemical stability and hardness. Therefore, the content of Y2O3 is controlled to be 1.0-3.0%.

[0020] The second aspect of the present application provides a preparation method of high aluminum glass, the preparation method comprising at least the following steps:

[0021] (1) The raw materials are weighed according to the component ratio, mixed uniformly in a mixer to obtain a mixture of ingredients;

[0022] (2) the ingredient mixture is subjected to high-temperature melting treatment, and a moderate-strength magnetic field is introduced in the later stage of the melting treatment;

[0023] (3) the melted mixture is cast into a mold to form and is subjected to annealing treatment, to obtain a glass raw sheet;

[0024] (4) the glass raw sheet is subjected to strengthening treatment, to obtain a product high-alumina glass.

[0025] Further, the melting treatment temperature in step (2) is 1500-1600 DEG C, and the melting treatment time is 4-5h.

[0026] Further, the magnetic field treatment is for 20-40 minutes, and the magnetic field strength is 3-4T. The magnetic field can inhibit the thermal convection of the melt, so that the flow is more stable, thereby reducing the erosion of the refractory material and the generation of stripes, and improving the homogenization. The magnetic field can also eliminate bubbles. The magnetic field can change the tension of the glass liquid and bubble interface or the refractory material interface, which is beneficial to the detachment and growth of the bubbles. The magnetic field can also affect the diffusion and arrangement of metal ions, thereby affecting the glass performance.

[0027] Further, the annealing temperature in step (3) is 600-700 DEG C, and the annealing time is 2-4h.

[0028] Further, the strengthening treatment operation in step (4) is: the strengthening treatment operation is: the strengthening uses a mixed salt of sodium nitrate and potassium nitrate, and the mixing ratio is 1:1-2.5; the strengthening temperature is 350-420 DEG C, and the strengthening time is 1-3h.

[0029] Further, a microwave treatment of 2-3GHz is applied in the strengthening process. The microwave energy directly acts on the whole glass, and the inside and outside of the glass are heated at the same time, the heating speed is extremely fast, the process time can be shortened, the whole body is uniformly heated, and the micro-cracks caused by local overheating are avoided. The microwave auxiliary can make the potassium ions or sodium ions in the molten salt penetrate into the glass interior more quickly and deeply, so as to form a thicker compressive stress layer (DOL), which means that the glass can obtain higher impact resistance, bending resistance and damage resistance.

[0030] Compared with the prior art, the beneficial effects of the present application are:

[0031] The high-alumina glass provided by the present application has excellent mechanical properties, the surface compressive stress (CS value) is greater than or equal to 1000MPa, the stress layer depth (DOL) is greater than or equal to 100um, and at the same time has high hardness, high light transmittance, scratch resistance, drop resistance and high stability, etc. Attached Figure Description

[0032] Figure 1 This is a photograph of the original glass sheet prepared in Example 1;

[0033] Figure 2 This is a photograph of the high-alumina glass prepared in Example 1. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solution, the present invention will be described in detail below with reference to embodiments. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0035] Example 1

[0036] This embodiment discloses a method for preparing high-alumina glass, including the following steps:

[0037] (1) Weigh the raw materials according to the component ratio, put the raw materials into the mixer and mix them evenly to obtain the batching mixture;

[0038] (2) The ingredients mixture is melted at 1600℃ for 4 hours, and a 3T magnetic field is introduced for 30 minutes in the later stage of the melt treatment;

[0039] (3) The molten mixture is poured into a mold and shaped at 900°C, and then annealed at 700°C for 3 hours to obtain the glass sheet;

[0040] (4) The glass substrate was placed in a mixed salt bath of sodium nitrate and potassium nitrate (mass ratio of sodium nitrate to potassium nitrate is 1:1) at 400°C for 1.5 h; microwave assisted treatment at 2 GHz was used during the strengthening process.

[0041] Actual image of the original glass sheet Figure 1 As shown in the image, a physical picture of high-alumina glass (strengthened glass) is as follows. Figure 2 As shown.

[0042] Examples 2-5

[0043] Adjust the dosage of each component, otherwise remain the same as in Example 1. The dosage of each component in Examples 1-5 is shown in Table 1.

[0044] Table 1. Dosage of each component

[0045]

[0046] Comparative Example 1

[0047] Compared to Example 1, the difference is that the strengthening process does not use microwave assistance.

[0048] Comparative Example 2

[0049] The difference compared to Example 1 is that no magnetic field treatment is used after the melting treatment.

[0050] Comparative Example 3

[0051] The difference compared to Example 1 is that only the mixed salt of sodium nitrate and potassium nitrate is used for 3.5 h.

[0052] Comparative Example 4

[0053] The difference compared to Example 1 is that Y2O31.8% ， B2O31.2%, the mass ratio of Y2O3 to B2O3 is 1.5.

[0054] Comparative Example 5

[0055] The difference compared to Example 1 is that Y2O32.3% ， B2O30.7%.

[0056] Comparative Example 6

[0057] The difference compared to Example 1 is that no Y2O3 is used, and SiO2 is 67%.

[0058] Comparative Example 7

[0059] The difference compared to Example 1 is that no B2O3 is used, and SiO2 is 66%.

[0060] Comparative Example 8

[0061] The difference compared to Example 1 is that no TiO2 is used, and SiO2 is 66%.

[0062] Comparative Example 9

[0063] The difference compared to Example 1 is that no CaO is used, and MgO is 3%.

[0064] Comparative Example 10

[0065] The difference compared to Example 1 is that no MgO is used, and CaO is 3%.

[0066] Comparative Example 11

[0067] The difference compared to Example 1 is that CaO is 2% and MgO is 1%.

[0068] Comparative Example 12

[0069] The difference compared to Example 1 is that CaO is 1% and MgO is 2%.

[0070] The performance test results of Examples 1-5 and Comparative Examples 1-12 are shown in Tables 2-4.

[0071] Table 2 Performance parameter test values ​​of Examples 1-5

[0072]

[0073]

[0074]

[0075] It should be noted that, in this document, the terms "comprising," "including," and any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Specific examples have been used in this document to illustrate the principles and implementation methods of the present invention. These examples are merely for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be pointed out that, due to the limitations of written expression and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or variations without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, variations, or combinations, or the direct application of the concept and technical solution of the present invention to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A high-alumina glass, characterized in that, By mass percentage, its raw material components include SiO2 60.0~70.0%, Al2O3 10.0~20.0%, Na2O 3.0~6.0%, K2O 2.0~5.0%, Li2O 0.0~4.0%, CaO 1.0~5.0%, MgO 0.5~4.0%, ZrO2 1.0~4.0%, TiO2 0.5~3.0%, Y2O3 1.0~3.0%, and B2O3 0.5~1.0%; wherein the mass ratio of Y2O3 to B2O3 is 2-3.

2. The high-alumina glass according to claim 1, characterized in that, The mass ratio of CaO to MgO is 1:0.8-1.

5.

3. The high-alumina glass according to claim 1, characterized in that, The thickness of the high-alumina glass is 0.5-2mm.

4. The high-alumina glass according to claim 1, characterized in that, The combined content of Na2O, K2O, and Li2O is 8.0~12.0%.

5. The method for preparing high-alumina glass as described in claim 1, characterized in that, Includes the following steps: (1) Weigh the raw materials according to the component ratio, put the raw materials into the mixer and mix them evenly to obtain the batching mixture; (2) The ingredients mixture is subjected to high-temperature melting treatment, and a medium-intensity magnetic field is introduced in the later stage of the melting treatment; (3) The molten mixture is poured into a mold to form a shape and then annealed to obtain a glass sheet; (4) Strengthen the glass sheet to obtain high-alumina glass; The magnetic field treatment lasts for 20-40 minutes, with a magnetic field strength of 3-4T.

6. The method for preparing high-alumina glass according to claim 5, characterized in that, In step (2), the melting temperature is 1500-1600℃ and the melting time is 4-5h.

7. The method for preparing high-alumina glass according to claim 5, characterized in that, In step (3), the annealing temperature is 600-700℃ and the annealing time is 2-4h.

8. The method for preparing high-alumina glass according to claim 5, characterized in that, The enhancement treatment in step (4) is as follows: a mixed salt of sodium nitrate and potassium nitrate is used, with a mixing ratio of 1:1-2.5; the enhancement temperature is 350-420℃, and the enhancement time is 1-3h.

9. The method for preparing high-alumina glass according to claim 5, characterized in that, The enhancement process is aided by the application of 2-3 GHz microwave processing.

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