Magnesium-aluminum-silicon microcrystalline glass and preparation method thereof

Abstract

The invention relates to the technical field of glass ceramics, and discloses magnesium-aluminum-silicon glass ceramics and a preparation method thereof, and the crystalline phase content of the magnesium-aluminum-silicon glass ceramics is not less than 20%; the invention relates to a high-temperature-resistant magnesium alloy, which contains one or more crystalline phases selected from the group consisting of MgAl2Si3O10, MgAl2Si4O12 and Mg2Al4Si5O18. The average grain size is less than or equal to 50nm; in a visible light wavelength range, the light transmittance is greater than or equal to 80%; and the Vickers hardness is greater than or equal to 700kgf / mm The microcrystalline glass not only has good light transmission performance, but also has good hardness.

Description

Technical Field

[0001] The present invention relates to the technical field of glass-ceramics, and specifically to a magnesium-aluminum-silicon glass-ceramic and a preparation method thereof. Background Art

[0002] MgO-A1 2 0 3 -SiO 2 System glass-ceramics tend to phase separation during glass cooling. The glass consists of different glass phases, and these phase separation processes control the nucleation and crystallization processes of the formation of glass-ceramics. MgO-A1 2 0 3 -SiO 2 The crystallization of the system is relatively complex, and various metastable and stable crystals can be precipitated during the crystallization process. This is related to the glass composition, heat treatment process, and the type of nucleating agent. Among them, the most important is cordierite-type glass-ceramics. Although a series of phase transformation processes are experienced during the crystallization process, the stable main crystal phase precipitated is cordierite, and there are also cristobalite, rutile, and magnesium dititanate crystals. The glass-ceramics prepared from magnesium-aluminum-silicon-based glass have excellent properties such as good insulation, high mechanical strength, and excellent dielectric properties, and can be widely used in radar radomes, integrated circuit substrates, etc.!31. Therefore, magnesium-based glass-ceramics have always been a research hotspot.

[0003] The patent with the patent application number CN202111056618.6 discloses a transparent high-hard magnesium-aluminum-silicon glass-ceramic, and its raw materials are composed of the following components: SiO 2 、MgO、Al 2 O 3 、Li 2 O、ZnO、ZrO 2 、P 2 O 5 、CeO 2 、SnO 2 、Sb 2 O 3 。 The invention also simultaneously provides a preparation method of the above-mentioned transparent high-hard magnesium-aluminum-silicon glass-ceramic, including the following steps: uniformly mixing the raw materials, heating up to obtain molten glass liquid; pouring the molten glass liquid into a preheated mold for molding, demolding after cooling, then annealing, and then cooling to room temperature; cutting the obtained annealed glass into glass sheets and polishing; after cutting into the required specifications, performing nucleation treatment to obtain a transparent high-hard magnesium-aluminum-silicon glass-ceramic. The transparent high-hard magnesium-aluminum-silicon glass-ceramic of the present invention is a magnesium-aluminum-silicon glass-ceramic with high transmittance and high strength suitable for use on the surface of smart phones. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a magnesium-aluminum-silicon microcrystalline glass and a preparation method thereof. On the basis of ensuring good light transmission performance, the crystallization ability and bending strength of the magnesium-silicon-aluminum microcrystalline glass are also improved.

[0005] A magnesium-aluminum-silicon microcrystalline glass with a crystalline phase content of not less than 20%; containing one or more crystalline phases of MgAl 2 Si 3 O 10 、MgAl 2 Si 4 O 12 、Mg 2 Al 4 Si 5 O 18 ; the average grain size is less than or equal to 50 nm; in the visible light wavelength range, its light transmittance ≥ 80%; Vickers hardness ≥ 700 kgf / mm 2 .

[0006] Further, when the main crystal phase composition is MgAl 2 Si 3 O 10 or MgAl 2 Si 4 O 12 or MgAl 2 Si 3 O 10 and MgAl 2 Si 4 O 12 , the crystallinity of the magnesium-aluminum-silicon microcrystalline glass ≥ 60%.

[0007] Further, a silicon-nickel coating is provided on the surface of the magnesium-aluminum-silicon microcrystalline glass.

[0008] Furthermore, the thickness of the silicon-nickel coating is 0.1 - 2 µm.

[0009] A preparation method of the aforementioned magnesium-aluminum-silicon microcrystalline glass is carried out according to the following steps: (1) Preparation of the glass mixture: Weigh 50 - 62 parts by weight of glass components SiO 2 , 25 - 32 parts of Al 2 O 3 , 5 - 10 parts of MgO, 1.5 - 2.5 parts of LiO 2 and 3 - 8 parts of ZrO 2 , fully grind and mix evenly, and pass through a 50 - 100 mesh sieve to obtain the glass mixture; (2)Preparation of magnesium-aluminum-silicon glass-ceramics: Using a silicon carbide rod electric furnace, the glass mixture in step (1) is melted at 1300 - 1600 °C for 2 - 4 h. After the glass liquid is completely melted, it is poured onto a preheated stainless-steel mold. After forming, the sample is placed in a muffle furnace at 500 - 700 °C for heat preservation for 50 - 90 min for annealing treatment. Then, the obtained base glass is put into the muffle furnace and heated to 750 - 850 °C at a heating rate of 3 - 6 °C / min for heat preservation for 2 - 4 h for nucleation treatment, and then heated to 800 - 1100 °C at a heating rate of 6 - 10 °C / min for heat preservation for 3 - 6 h for crystallization treatment. Then it is cooled to room temperature to obtain the target glass-ceramics.

[0010] Further, the mixture in step 1 also contains 0 - 5 parts of P 2 O 5 , 0 - 0.5 parts of SrO, 0 - 0.5 parts of BaO, 0 - 0.5 parts of Na 2 O, 0 - 0.5 parts of K 2 O, 0 - 0.5 parts of CaO, 0 - 5 parts of B 2 O 3 , 0 - 4 parts of Y 2 O 3 , 0 - 1 part of Sb 2 O 3 .

[0011] The mass ratio of MgO / (MgO + CaO + SrO + BaO) in step 1 is 0.87 - 1; the mass ratio of Li 2 O / Li 2 O + Na 2 O + K 2 O is 0.86 - 1. The purpose of controlling the mass ratio of MgO / (MgO + CaO + SrO + BaO) is to ensure that the glass-ceramics have good transparency. When the proportion of CaO, SrO, and BaO exceeds the above limit, the transmittance decreases significantly. Mainly when there is a certain content of CaO, SrO, and BaO exceeding the above proportion limit, a small amount of CaO, SrO, and BaO-containing heterogeneous phase crystals are formed, and there are differences in the refractive index of the remaining target crystals, etc. Therefore, it will increase the refraction and scattering of light inside the glass-ceramics and reduce the transmittance. Li 2 O / Li 2 O + Na 2 O + K 2The purpose of the mass ratio of O is to achieve good melting effect and the required stress distribution after strengthening. Among the three alkali metal oxides of lithium, sodium, and potassium, the lithium ion has the smallest atomic radius, and has the most obvious effect on reducing the melting temperature. At the same time, when lithium-sodium and lithium-potassium ion exchanges occur, it is easy to achieve a larger ion exchange depth and a larger internal compressive stress, which is helpful for improving the overall mechanical properties of the strengthened glass-ceramics. If the lithium content is lower than the above limiting proportional relationship, it will have an adverse impact on the melting effect and the stress distribution after chemical strengthening.

[0012] Preferably, the magnesium-aluminum-silicon glass-ceramics obtained in the above steps can also be subjected to hot bending treatment. The specific step (3) is as follows: Place the glass-ceramics obtained in step (2) in the graphite mold cavity of an ultra-thin glass hot bending device, and perform a pressing operation on the glass by the upper and lower molds in the device. Perform hot pressing forming in a nitrogen atmosphere. At a certain preset molding rate, move the glass to the heating section, first keep it at 700 - 850 °C for 60 - 180 s, then raise the temperature to 850 - 900 °C and keep it for 60 - 180 s. Then move the glass to the bending section, keep it at 750 - 880 °C for 60 - 180 s, then move the glass to the annealing section, keep it at 820 - 870 °C for 60 - 180 s, and finally move it to the cooling section, keep it at 750 - 800 °C for 60 - 180 s, and cool it naturally to obtain hot-bent magnesium-aluminum-silicon glass-ceramics; In the step (3), the preset pressure is 0.2 - 0.9 MPa, and the preset molding rate is 10 - 15 mm / min.

[0013] The present invention also provides a preparation method of magnesium-aluminum-silicon glass-ceramics with a silicon-nickel coating on the surface. The magnesium-aluminum-silicon glass-ceramics are carried out according to the following steps: (1) Preparation of glass mixture: Weigh 50 - 62 parts by weight of SiO 2 、25 - 32 parts of Al 2 O 3 、5 - 10 parts of MgO, 1.5 - 2.5 parts of LiO 2 and 3 - 8 parts of ZrO 2 , fully grind and mix evenly, and pass through a 50 - 100 mesh sieve to obtain a glass mixture; (2)Preparation of the base glass-ceramics: Using a silicon carbide rod electric furnace, the glass mixture in step (1) is melted at 1300 - 1600 °C for 2 - 4 h. After the glass liquid is completely melted, it is poured onto a preheated stainless-steel mold. After forming, the sample is placed in a muffle furnace at 500 - 700 °C for heat preservation for 50 - 90 min for annealing treatment. Then, the obtained base glass is put into the muffle furnace and heated to 750 - 850 °C at a heating rate of 3 - 6 °C / min for heat preservation for 2 - 4 h for nucleation treatment. Then, it is heated to 800 - 1100 °C at a heating rate of 6 - 10 °C / min for heat preservation for 3 - 6 h for crystallization treatment. Then, it is cooled to room temperature to obtain the base glass-ceramics; (3)Preparation of the heat-bent magnesium-aluminum-silicon glass-ceramics: The base glass-ceramics in step (2) are placed in the graphite mold cavity of the ultra-thin glass heat-bending device. The glass is pressed by the upper and lower molds in the device, and hot pressing is carried out under a nitrogen atmosphere. At a certain preset molding rate, the glass is moved to the heating section, first heat-preserved at 700 - 850 °C for 60 - 180 s, then heated to 850 - 900 °C for heat preservation for 60 - 180 s. Then, the glass is moved to the bending section, heat-preserved at 750 - 880 °C for 60 - 180 s. Then, the glass is moved to the annealing section, heat-preserved at 820 - 870 °C for 60 - 180 s. Finally, it is moved to the cooling section, heat-preserved at 750 - 800 °C for 60 - 180 s, and cooled naturally to obtain the heat-bent magnesium-aluminum-silicon glass-ceramics; (4)Preparation of the silicon-nickel sol: Add tetraethyl orthosilicate, nickel nitrate hexahydrate, deionized water, and ethanol to the reaction flask, stir evenly, and then add hydrochloric acid with a mass fraction of 36 - 38%, and continue to stir for 5 - 12 h to mix evenly to obtain a transparent silicon-nickel sol; (5)Preparation of the magnesium-aluminum-silicon glass-ceramics with a silicon-nickel coating on the surface: After the surface of the heat-bent magnesium-aluminum-silicon glass-ceramics prepared in step (3) is cleaned, the sol in step (4) is evenly coated on the glass surface by the dip-coating and pulling method. After coating, it is dried in a constant-temperature oven at 40 - 60 °C for 4 - 8 h. Then, the sample is put into a temperature-controlled furnace for heat treatment, heated to 600 - 900 °C at a rate of 0.5 - 1 °C, heat-preserved at the end temperature for 2 - 5 h, and cooled to room temperature to obtain the magnesium-aluminum-silicon glass-ceramics with a silicon-nickel coating on the surface.

[0014] Further, in step (3), the preset pressure is 0.2 - 0.9 MPa, and the preset molding rate is 10 - 15 mm / min.

[0015] Further, in step (4), the dosage ratio of tetraethyl orthosilicate, nickel nitrate hexahydrate, deionized water, ethanol, and hydrochloric acid is 2 - 10 g: 0.5 - 2.5 g: 5 - 25 mL: 15 - 35 mL: 0.6 - 1.5 g in sequence.

[0016] Further, in the step (4), the stirring temperature is 40 - 60 °C, and the stirring time is 0.5 - 1 h.

[0017] Further, in the step (5), the pulling speed is 2 - 10 cm / min.

[0018] (III) Beneficial technical effects By controlling the proportional relationship of the main components in the magnesium-aluminum-silicon glass-ceramics, on the basis of ensuring the glass-ceramic network structure, the grain size is controlled so that the average grain size is less than 50 nm, ensuring that the glass-ceramics have good light transmission performance; at the same time, the main crystal phase in the prepared glass-ceramics has good hardness whether it is a single crystal phase or multiple crystal phases. In particular, the purpose of controlling the mass ratio of MgO / (MgO + CaO + SrO + BaO) is to ensure that the glass-ceramics have good transparency; Li 2 O / Li 2 O + Na 2 O + K 2 The purpose of the mass ratio of O is to achieve good melting effect and the required stress distribution after strengthening. Among the three alkali metal oxides of lithium, sodium, and potassium, the atomic radius of lithium ion is the smallest, and the effect on reducing the melting temperature is the most obvious. At the same time, when lithium-sodium and lithium-potassium ion exchanges occur, lithium ions are easy to achieve a larger ion exchange depth and a larger internal compressive stress, which is of great help for improving the overall mechanical properties of the strengthened glass-ceramics. If the content of lithium is lower than the above limiting proportional relationship, the melting effect and the stress distribution after chemical strengthening will be adversely affected.

[0019] Further, the silicon-nickel coating prepared by the sol-gel method is dip-coated and pulled on the magnesium-aluminum-silicon glass, so that the magnesium-silicon-aluminum glass has good corrosion resistance. The silicon-nickel coating prepared by the sol-gel method overcomes the problem of uneven mixing in the conventional method. In the subsequent heat treatment process, after the silica in the coating is gelated by heat treatment, it bonds with the silicon-oxygen bonds inside the glass, making the entire structure of the glass more firm. At the same time, the sol forms a dense coating on the glass surface, repairing the broken bonds and dangling bonds on the surface, and greatly improving the flexural strength and corrosion resistance; the 3D hot bending process goes through the stages of preheating, pressurization, annealing, and cooling, and transfers heat to the glass by means of heat conduction, making the glass heat evenly during the heating process and enhancing the mechanical properties of the glass. Description of the drawings

[0020] Figure 1 XRD pattern of the glass-ceramics prepared in Example 1 of the present invention; Figure 2 SEM photograph of the glass-ceramics prepared in Example 1 of the present invention; Figure 3Transmittance test results of the glass-ceramics prepared in Example 1 of the present invention. Detailed implementation manners

[0021] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0022] Example 1

[0023] (1) Preparation of glass mixture: Weigh 52 parts by weight of SiO 2 , 29.4 parts of Al 2 O 3 , 8.5 parts of MgO, 2.2 parts of Li 2 O, 7.4 parts of ZrO 2 and 0.5 part of Sb 2 O 3 After fully grinding and mixing evenly, pass through an 80-mesh sieve to obtain a glass mixture.

[0024] (2) Preparation of magnesium-aluminum-silicon glass-ceramics: Use a silicon carbide rod electric furnace to melt the glass mixture in step (1) at 1450 °C for 3 h. After the glass liquid is completely melted, pour it onto a preheated stainless steel mold. After forming, place the sample in a muffle furnace at 500 °C for 60 min for annealing treatment. Then, put the obtained base glass into the muffle furnace and raise the temperature to 750 °C at a heating rate of 5 °C / min for 3 h for nucleation treatment. Then, raise the temperature to 900 °C at a heating rate of 9 °C / min for 5 h for crystallization treatment. Then, cool to room temperature to obtain magnesium-aluminum-silicon glass-ceramics.

[0025] Perform XRD test on the obtained magnesium-aluminum-silicon glass-ceramics. The test results are as Figure 1 shown. From the XRD test pattern, it can be seen that the main crystal phase in the obtained glass-ceramics is MgAl 2 Si 3 O 10 , and at the same time, it contains a small amount of ZrO 2 . Perform SEM characterization on the obtained magnesium-aluminum-silicon glass-ceramics. The characterization results are as Figure 2 shown. From the SEM image, it can be seen that the overall crystallinity of the obtained glass-ceramics is relatively high. After calculation, the crystallinity of the glass-ceramics prepared in this example is 69.9%, and the average grain size does not exceed 50 nm. Perform transmittance test. In the visible light wavelength range, its transmittance is not less than 90%. The test results are as Figure 3 shown. The Vickers hardness of the magnesium-aluminum-silicon glass-ceramics in this example is 728 kgf / mm2。

[0026] Example 2

[0027] (1)Preparation of glass mixture: Weigh 52.6 parts by weight of glass component SiO 2 、31.2 parts of Al 2 O 3 、8.9 parts of MgO, 2.3 parts of Li 2 O, 0.1 part of Na 2 O, 4.6 parts of ZrO 2 and 0.4 part of Sb 2 O 3 , fully grind and mix evenly, pass through an 80-mesh sieve to obtain the glass mixture.

[0028] (2)Preparation of magnesium-aluminum-silicon glass-ceramics: Use a silicon carbide rod electric furnace to melt the glass mixture in step (1) at 1450 °C for 3 h. After the glass liquid is completely melted, pour it onto a preheated stainless steel mold. After molding, place the sample in a muffle furnace at 500 °C for 60 min for annealing treatment. Then put the obtained base glass into the muffle furnace, raise the temperature to 760 °C at a rate of 5 °C / min and hold for 4 h for nucleation treatment, and then raise the temperature to 950 °C at a rate of 9 °C / min and hold for 5 h for crystallization treatment. Then cool to room temperature to obtain magnesium-aluminum-silicon glass-ceramics.

[0029] Perform XRD testing on the prepared magnesium-aluminum-silicon glass-ceramics. It is clear from the XRD test results that the main crystal phases in the prepared glass-ceramics are MgAl 2 Si 3 O 10 and MgAl 2 Si 4 O 12 . Perform SEM characterization on the prepared magnesium-aluminum-silicon glass-ceramics. The SEM image shows that the overall crystallinity of the prepared glass-ceramics is relatively high. After calculation, the crystallinity of the glass-ceramics prepared in this example is 67.4%, and the average grain size does not exceed 50 nm. Perform transmittance testing. In the visible light wavelength range, its transmittance is not less than 88%. The Vickers hardness of the magnesium-aluminum-silicon glass-ceramics in this example is 724.6 kgf / mm 2 .

[0030] Example 3

[0031] (1)Preparation of glass mixture: Weigh 53.1 parts by weight of glass component SiO 2 、31.5 parts of Al 2 O 3 、9 parts of MgO, 2.25 parts of Li 2 O, 0.2 part of K 2O, 3.75 parts of ZrO 2 and 0.4 parts of Sb 2 O 3 , after fully grinding and mixing evenly, passing through an 80-mesh sieve to obtain a glass mixture.

[0032] (2) Preparation of magnesium aluminosilicate glass-ceramics: Using a silicon carbide rod electric furnace, melting the glass mixture in step (1) at 1450 °C for 3 h. After the glass liquid is completely melted, pour it onto a preheated stainless steel mold. After forming, place the sample in a muffle furnace at 650 °C for 70 min for annealing treatment. Then put the obtained base glass into the muffle furnace, raise the temperature to 800 °C at a heating rate of 5 °C / min and hold for 4 h for nucleation treatment, and then raise the temperature to 1000 °C at a heating rate of 9 °C / min and hold for 5 h for crystallization treatment. Then cool to room temperature to obtain magnesium aluminosilicate glass-ceramics. The Vickers hardness of the magnesium aluminosilicate glass-ceramics in this example is 722.4 kgf / mm 2 .

[0033] Conduct XRD testing on the prepared magnesium aluminosilicate glass-ceramics. From the results of the XRD test pattern, it is clear that the main crystal phase in the prepared glass-ceramics is MgAl 2 Si 4 O 12 . Conduct SEM characterization on the prepared magnesium aluminosilicate glass-ceramics. The SEM image shows that the overall crystallinity of the prepared glass-ceramics is relatively high. After calculation, the crystallinity of the glass-ceramics prepared in this example is 66.2%, and the average grain size does not exceed 50 nm. Conduct transmittance testing. In the visible light wavelength range, its transmittance is not less than 85%.

[0034] It is also possible to conduct hot bending treatment on the prepared magnesium aluminosilicate glass-ceramics: Place the base glass-ceramics in step (2) in the graphite mold cavity of an ultra-thin glass hot bending device, perform a pressurizing operation on the glass by the upper and lower molds in the device, and conduct hot pressing forming under a nitrogen atmosphere. At a pressure of 0.35 MPa and a preset mold pressing rate of 13 mm / min, move the glass to the heating section, first hold at 820 °C for 60 s, then raise the temperature to 870 °C and hold for 80 s. Then move the glass to the bending section, hold at 790 °C for 110 s, then move the glass to the annealing section, hold at 850 °C for 105 s, and finally move to the cooling section, hold at 760 °C for 80 s, and cool naturally to obtain the hot-bent magnesium aluminosilicate glass-ceramics.

[0035] Example 4

[0036] (1) Preparation of glass mixture: Weigh 58.2 parts of SiO 2 , 27.8 parts of Al 2 O 3 , 8.2 parts of MgO, 2 parts of Li2 O, 0.4 parts of K 2 O, 3.75 parts of ZrO 2 and 0.3 parts of Sb 2 O 3 , mix evenly after thorough grinding, and pass through an 80-mesh sieve to obtain a glass mixture.

[0037] (2) Preparation of magnesium aluminosilicate glass-ceramics: Using a silicon carbide rod electric furnace, melt the glass mixture in step (1) at 1450 °C for 3 h. After the glass melt is completely melted, pour it onto a preheated stainless steel mold. After forming, place the sample in a muffle furnace at 670 °C and hold for 60 min for annealing treatment. Then, put the obtained base glass into the muffle furnace, raise the temperature to 820 °C at a heating rate of 5 °C / min and hold for 4 h for nucleation treatment. Then, raise the temperature to 1050 °C at a heating rate of 9 °C / min and hold for 5 h for crystallization treatment. Then, cool to room temperature to obtain magnesium aluminosilicate glass-ceramics.

[0038] Perform XRD testing on the prepared magnesium aluminosilicate glass-ceramics. From the results of the XRD test pattern, it is clear that the main crystal phase in the prepared glass-ceramics is MgAl 2 Si 4 O 12 and Mg 2 Al 4 Si 5 O 18 . Perform SEM characterization on the prepared magnesium aluminosilicate glass-ceramics. The SEM image shows that the overall crystallinity of the prepared glass-ceramics is relatively high. After calculation, the crystallinity of the glass-ceramics prepared in this example is 50.4%, and the average grain size does not exceed 50 nm. Perform light transmittance testing. In the visible light wavelength range, its light transmittance is not less than 85%. The Vickers hardness of the magnesium aluminosilicate glass-ceramics in this example is 714.3 kgf / mm 2 .

[0039] Example 5 (1) Preparation of glass mixture: Weigh 61.5 parts of SiO 2 , 25.5 parts of Al 2 O 3 , 7.4 parts of MgO, 1.8 parts of Li 2 O, 0.4 parts of Na 2 O, 3.3 parts of ZrO 2 and 0.5 parts of Sb 2 O 3 , mix evenly after thorough grinding, and pass through an 80-mesh sieve to obtain a glass mixture.

[0040] (2)Preparation of magnesium aluminosilicate glass-ceramics: Using a silicon carbide rod electric furnace, the glass mixture in step (1) is melted at 1450 °C for 3 h. After the glass liquid is completely melted, it is poured onto a preheated stainless steel mold. After forming, the sample is placed in a muffle furnace at 700 °C and kept warm for 60 min for annealing treatment. Then, the obtained base glass is put into the muffle furnace and heated to 850 °C at a heating rate of 5 °C / min and kept warm for 4 h for nucleation treatment. Then, it is heated to 1100 °C at a heating rate of 9 °C / min and kept warm for 6 h for crystallization treatment. Then, it is cooled to room temperature to obtain magnesium aluminosilicate glass-ceramics.

[0041] XRD test is carried out on the prepared magnesium aluminosilicate glass-ceramics. From the results of the XRD test pattern, it is clear that the main crystal phase in the prepared glass-ceramics is Mg 2 Al 4 Si 5 O 18 . SEM characterization is carried out on the prepared magnesium aluminosilicate glass-ceramics. The SEM image shows that the overall crystallinity of the prepared glass-ceramics is relatively high. After calculation, the crystallinity of the glass-ceramics prepared in this example is 29.8%, and the average grain size does not exceed 50 nm. Transmittance test is carried out. In the visible light wavelength range, its transmittance is not less than 82%. The Vickers hardness of the magnesium aluminosilicate glass-ceramics in this example is 700.8 kgf / mm 2 .

[0042] The prepared magnesium aluminosilicate glass-ceramics can also be subjected to hot bending treatment: The base glass-ceramics in step (2) are placed in the graphite mold cavity of the ultra-thin glass hot bending device, and the glass is pressurized by the upper and lower molds in the device, and hot pressing forming is carried out under a nitrogen atmosphere. At a pressure of 0.35 MPa and a preset molding rate of 13 mm / min, the glass is moved to the heating section, first kept warm at 855 °C for 60 s, then heated to 900 °C and kept warm for 90 s, then the glass is moved to the bending section, kept warm at 810 °C for 100 s, then the glass is moved to the annealing section, kept warm at 870 °C for 120 s, and finally moved to the cooling section, kept warm at 800 °C for 80 s, and naturally cooled to obtain the hot-bent magnesium aluminosilicate glass-ceramics.

[0043] Example 6

[0044] (1)Preparation of glass mixture: Weigh 50.7 parts of SiO 2 , 30.5 parts of Al 2 O 3 , 5.2 parts of MgO, 2.1 parts of Li 2 O, 0.4 parts of Na 2 O, 0.1 parts of K 2 O, 6.9 parts of ZnO, 4.3 parts of ZrO 2 and 0.2 parts of Sb2 O 3 After thorough grinding, mix evenly and sieve through a 80-mesh sieve to obtain a glass mixture.

[0045] (2) Preparation of magnesium aluminosilicate glass-ceramics: Using a silicon carbide rod electric furnace, melt the glass mixture in step (1) at 1450 °C for 3 h. After the glass liquid is completely melted, pour it onto a preheated stainless steel mold. After forming, place the sample in a muffle furnace at 700 °C for 60 min for annealing treatment. Then, put the obtained base glass into the muffle furnace and heat it to 850 °C at a heating rate of 5 °C / min and hold for 3 h for nucleation treatment. Then, heat it to 1080 °C at a heating rate of 9 °C / min and hold for 5.5 h for crystallization treatment. Then, cool it to room temperature to obtain magnesium aluminosilicate glass-ceramics.

[0046] Perform XRD testing on the prepared magnesium aluminosilicate glass-ceramics. From the results of the XRD test pattern, it is clear that the main crystal phase in the prepared glass-ceramics is MgAl 2 Si 3 O 10 and Mg 2 Al 4 Si 5 O 18 . Perform SEM characterization on the prepared magnesium aluminosilicate glass-ceramics. The SEM image shows that the overall crystallinity of the prepared glass-ceramics is relatively high. After calculation, the crystallinity of the glass-ceramics prepared in this example is 42.5%, and the average grain size does not exceed 50 nm. Perform transmittance testing. In the visible light wavelength range, its transmittance is not less than 80%. The Vickers hardness of the magnesium aluminosilicate glass-ceramics in this example is 708.8 kgf / mm 2 .

[0047] Example 7

[0048] (1) Preparation of glass mixture: Weigh 52.2 parts of SiO 2 , 29.4 parts of Al 2 O 3 , 8.5 parts of MgO, 0.1 part of CaO, 2.2 parts of Li 2 O, 7.4 parts of ZrO 2 and 0.3 part of Sb 2 O 3 by weight. After thorough grinding, mix evenly and sieve through a 80-mesh sieve to obtain a glass mixture. After thorough grinding, mix evenly and sieve through a 80-mesh sieve to obtain a glass mixture.

[0049] (2)Preparation of magnesium-aluminum-silicon microcrystalline glass: Using a silicon carbide rod electric furnace, the glass mixture in step (1) is melted at 1450 °C for 3 h. After the glass liquid is completely melted, it is poured onto a preheated stainless steel mold. After forming, the sample is placed in a muffle furnace at 700 °C and kept warm for 60 min for annealing treatment. Then, the obtained base glass is put into the muffle furnace and heated to 850 °C at a heating rate of 6 °C / min and kept warm for 3 h for nucleation treatment. Then, it is heated to 1060 °C at a heating rate of 10 °C / min and kept warm for 6 h for crystallization treatment. Then, it is cooled to room temperature to obtain the base microcrystalline glass.

[0050] The prepared magnesium-aluminum-silicon microcrystalline glass is subjected to XRD testing. From the results of the XRD test pattern, it is clear that the main crystal phase in the prepared microcrystalline glass is MgAl 2 Si 3 O 10 and MgAl 2 Si 4 O 12 , the secondary crystal phase is Mg 2 Al 4 Si 5 O 18 , and there is also a small amount of ZrO 2 . The prepared magnesium-aluminum-silicon microcrystalline glass is characterized by SEM. The SEM image shows that the overall crystallinity of the prepared microcrystalline glass is relatively high. After calculation, the crystallinity of the microcrystalline glass prepared in this example is 49.6%, and the average grain size does not exceed 50 nm. The light transmittance is tested. In the visible light wavelength range, its light transmittance is not less than 80%. The Vickers hardness of the magnesium-aluminum-silicon microcrystalline glass in this example is 710.2 kgf / mm 2 .

[0051] After the crystal phase simulation of the microcrystalline glass prepared in Examples 1-7 is calculated by the crystal phase simulation of MDIJADE6.5, the obtained crystal phase content data are shown in Table 1.

[0052] Sample <![CDATA[MgAl 2 Si 3 O 10 > <![CDATA[MgAl 2 Si 4 O 12 > <![CDATA[Mg 2 Al 4 Si 5 O 18 > <![CDATA[ZrO 2 > Crystallinity Example 1 97.9% 0 0 2.1% 69.9% Example 2 49.4% 46.8% 0 3.8% 67.4% Example 3 9.8% 87.6% 0 2.6% 66.2% Example 4 0 4.2% 93.3% 2.5% 50.4% Example 5 0 0 95.7% 4.3% 29.8% Example 6 57.8% 0 39% 3.2% 42.5% Example 7 39.8% 42.4% 15.2% 2.6% 49.6%

[0053] In the prior art, it is generally considered that ZrO 2 is a refractory oxide. When it exceeds 3 wt%, it is difficult to dissolve, which has an adverse effect on the melting and transparency of the glass. In Examples 1-7 of the present invention, the component ratio in the raw materials is optimized and auxiliary components are added, overcoming the technical prejudice. The microcrystalline glass prepared in Examples 1-7 has good light transmittance performance in the visible light wavelength range and can be applied to electronic devices for use as displays or covers.

[0054] Example 8

[0055] The difference between this example and Example 1 is that in step (1), 52.9 parts by weight of SiO of the glass components are weighed2 、 31.2 parts of Al 2 O 3 、 8.9 parts of MgO, 0.2 parts of SrO, 2.3 parts of Li 2 O, 4.6 parts of ZrO 2 and 0.1 part of Sb 2 O 3 , with other conditions remaining the same.

[0056] Example 9

[0057] The difference between this example and Example 1 is that in step (1), 53 parts by weight of the glass component SiO 2 、 31.5 parts of Al 2 O 3 、 9 parts of MgO, 0.3 parts of BaO, 2.25 parts of Li 2 O, 3.75 parts of ZrO 2 and 0.5 part of Sb 2 O 3 , with other conditions remaining the same.

[0058] Example 10

[0059] The difference between this example and Example 1 is that in step (1), 58.1 parts by weight of the glass component SiO 2 、 27.8 parts of Al 2 O 3 、 8.2 parts of MgO, 0.4 parts of CaO, 0.4 parts of SrO, 0.4 parts of BaO, 2 parts of Li 2 O, 3.5 parts of ZrO 2 and 0.4 part of Sb 2 O 3 , with other conditions remaining the same.

[0060] Example 11

[0061] The difference between this example and Example 1 is that in step (1), 61.5 parts by weight of the glass component SiO 2 、 25.8 parts of Al 2 O 3 、 7.4 parts of MgO, 0.2 parts of CaO, 0.2 parts of BaO, 1.8 parts of Li 2 O, 0.2 part of K 2 O, 0.1 part of NaO 2 、 3.3 parts of ZrO 2 and 0.2 part of Sb 2 O 3 , with other conditions remaining the same.

[0062] Example 12

[0063] The difference between this embodiment and Embodiment 1 is that in step (1), 50.7 parts by weight of SiO in the glass composition are weighed 2 , 30.5 parts of Al 2 O 3 , 5.2 parts of MgO, 0.2 parts of SrO, 0.1 parts of BaO, 2.1 parts of Li 2 O, 0.1 parts of NaO 2 , 0.1 parts of K 2 O, 6.9 parts of ZnO, 4.3 parts of ZrO 2 and 0.3 parts of Sb 2 O 3 , and other conditions remain the same.

[0064] Embodiment 13

[0065] The difference between this embodiment and Embodiment 1 is that in step (1), 51.9 parts by weight of SiO in the glass composition are weighed 2 , 28.1 parts of Al 2 O 3 , 8.5 parts of MgO, 0.1 parts of CaO, 2.2 parts of Li 2 O, 7.2 parts 1.5 parts of Y 2 O 3 and 0.5 parts of Sb 2 O 3 , and other conditions remain the same.

[0066] Embodiment 14

[0067] The difference between this embodiment and Embodiment 1 is that in step (1), 52.6 parts by weight of SiO in the glass composition are weighed 2 , 28.5 parts of Al 2 O 3 , 8.9 parts of MgO, 0.2 parts of SrO, 2.3 parts of Li 2 O, 0.1 parts of NaO 2 , 2.5 parts of B 2 O 3 , 4.7 parts of ZrO 2 and 0.2 parts of Sb 2 O 3 , and other conditions remain the same.

[0068] Embodiment 15

[0069] The difference between this embodiment and Embodiment 1 is that in step (1), 52.85 parts by weight of SiO in the glass composition are weighed 2 , 30.1 parts of Al 2 O 3 , 9 parts of MgO, 0.15 parts of BaO, 2.3 parts of Li2 O, 0.25 parts of K 2 O, 1.2 parts of P 2 O 5 , 3.75 parts of ZrO 2 and 0.4 parts of Sb 2 O 3 , other conditions remain the same.

[0070] Example 16

[0071] The difference between this example and Example 1 is that in step (1), 55.5 parts by weight of SiO of the glass components are weighed 2 , 27.8 parts of Al 2 O 3 , 8.2 parts of MgO, 1.9 parts of Li 2 O, 0.3 parts of K 2 O, 0.8 parts of Y 2 O 3 , 1.2 parts of B 2 O 3 , 0.3 parts of P 2 O 5 , 3.5 parts of ZrO 2 and 0.5 parts of Sb 2 O 3 , other conditions remain the same.

[0072] Comparative Example 1 The difference between this example and Example 1 is that in step (1), 49 parts by weight of SiO of the glass components are weighed 2 , 29.4 parts of Al 2 O 3 , 8.5 parts of MgO, 0.5 parts of CaO, 2.2 parts of Li 2 O, 0.5 parts of K 2 O, 1 part of ZnO, 1.2 parts of B 2 O 3 , 0.3 parts of P 2 O 5 , 7.4 parts of ZrO 2 and 0.5 parts of Sb 2 O 3 , other conditions remain the same.

[0073] Comparative Example 2 The difference between this example and Example 1 is that in step (1), 64.3 parts by weight of SiO of the glass components are weighed 2 , 26 parts of Al 2 O 3 , 6.5 parts of MgO, 1.9 parts of Li 2 O, 0.3 parts of K 2 O, 0.8 parts of Y2 O 3 、 1.2 parts of B 2 O 3 、 0.3 parts of P 2 O 5 、 3.5 parts of ZrO 2 and 0.2 parts of Sb 2 O 3 , with other conditions remaining the same.

[0074] Comparative Example 3 The difference between this example and Example 1 is that in step (1), 55.6 parts by weight of SiO in the glass components are weighed 2 、 27.8 parts of Al 2 O 3 、 8.2 parts of MgO, 1.9 parts of Li 2 O, 0.3 parts of K 2 O, 0.8 parts of Y 2 O 3 、 1.2 parts of B 2 O 3 、 0.3 parts of P 2 O 5 、 3.5 parts of ZrO 2 and 0.4 parts of Sb 2 O 3 , with other conditions remaining the same.

[0075] Comparative Example 4 The difference between this example and Example 1 is that in step (1), 55.5 parts by weight of SiO in the glass components are weighed 2 、 27.8 parts of Al 2 O 3 、 8.2 parts of MgO, 1.9 parts of Li 2 O, 0.3 parts of K 2 O, 0.8 parts of Y 2 O 3 、 1.2 parts of B 2 O 3 、 0.3 parts of P 2 O 5 、 3.5 parts of ZrO 2 and 0.5 parts of Sb 2 O 3 , with other conditions remaining the same.

[0076] Table 2 Related data table of the glass-ceramics prepared in Examples 8 - 16 and Comparative Examples 1 - 4 Sample <![CDATA[MgAl 2 Si 3 O 10 > <![CDATA[MgAl 2 Si 4 O 12 > <![CDATA[Mg 2 Al 4 Si 5 O 18 > <![CDATA[ZrO 2 > Crystallinity Transmittance <![CDATA[Vickers hardness (kgf / mm 2 )]]> Example 8 83.9% 12.4% 0 3.7% 63.4% 88% >700 Example 9 84.9% 12.2% 0 2.9% 62.5% 87% >700 Example 10 81.3% 16.3% 0 2.4% 61.9% 86% >700 Example 11 80.6% 17.2% 0 2.2% 61.8% 86% >700 Example 12 49.5% 21.3% 25.7% 3.5% 45.3% 81% >700 Example 13 91.4% 4.7% 0 3.9% 65.2% 89% >700 Example 14 62.3% 35.5% 0 2.2% 60.1% 82% >700 Example 15 40.7% 18.9% 38.2% 2.2% 40.5% 80% >700 Example 16 42.5% 21.2% 34.4% 1.9% 38.7% 80% >700 Comparative Example 1 70% Comparative Example 2 55% Comparative Example 3 62% Comparative Example 4 58% Example 17

[0077] First, place the glass-ceramics in Example 1 in the graphite mold cavity of the ultra-thin glass hot bending device. Press the glass with the upper and lower molds in the device, and perform hot pressing forming under a nitrogen atmosphere. Under a pressure of 0.35 MPa and a preset molding rate of 13 mm / min, move the glass to the heating section. First, keep it at 820 °C for 55 s, then heat it up to 860 °C and keep it for 75 s. Then move the glass to the bending section, keep it at 790 °C for 90 s, then move the glass to the annealing section, keep it at 850 °C for 105 s, and finally move it to the cooling section, keep it at 750 °C for 60 s, and cool it naturally to obtain the hot-bent magnesium-aluminum-silicon glass-ceramics.

[0078] Next, preparation of the silicon-nickel sol: Add 2 g of tetraethyl orthosilicate, 0.5 g of nickel nitrate hexahydrate, 5 mL of deionized water, and 15 mL of ethanol to the reaction flask. Stir at 55 °C for 0.5 h. After stirring evenly, then add 0.6 g of hydrochloric acid with a mass fraction of 37%, and continue to stir for 10 h to mix evenly and obtain a transparent silicon-nickel sol.

[0079] Finally, preparation of the magnesium-aluminum-silicon glass-ceramics with a silicon-nickel coating on the surface: After the surface of the magnesium-aluminum-silicon glass-ceramics prepared in the above steps is cleaned, use the dip-coating and pulling method to evenly coat the silicon-nickel sol on the glass surface. The pulling speed is 4 cm / min. After coating, dry it in a constant-temperature oven at 50 °C for 6 h. Then put the sample into a temperature-controlled furnace for heat treatment, heat it up to 850 °C at a rate of 0.6 °C, keep it at the final temperature for 4 h, and cool it to room temperature to obtain the magnesium-aluminum-silicon glass-ceramics with a silicon-nickel coating on the surface.

[0080] Example 18

[0081] First, place the glass-ceramics prepared in Example 2 in the graphite mold cavity of the ultra-thin glass hot bending device. Press the glass with the upper and lower molds in the device, and perform hot pressing forming under a nitrogen atmosphere. Under a pressure of 0.4 MPa and a preset molding rate of 15 mm / min, move the glass to the heating section. First, keep it at 830 °C for 60 s, then heat it up to 900 °C and keep it for 90 s. Then move the glass to the bending section, keep it at 780 °C for 85 s, then move the glass to the annealing section, keep it at 850 °C for 110 s, and finally move it to the cooling section, keep it at 800 °C for 70 s, and cool it naturally to obtain the hot-bent magnesium-aluminum-silicon glass-ceramics.

[0082] Next, preparation of the silicon-nickel sol: Add 4 g of tetraethyl orthosilicate, 1 g of nickel nitrate hexahydrate, 10 mL of deionized water, and 20 mL of ethanol to the reaction flask. Stir at 55 °C for 1 h. After stirring evenly, then add 0.9 g of hydrochloric acid with a mass fraction of 38%, and continue to stir for 9 h to mix evenly and obtain a transparent silicon-nickel sol.

[0083] Finally, preparation of magnesium aluminosilicate glass-ceramics with a silicon-nickel coating on the surface: After the surface of the heat-bent magnesium aluminosilicate glass-ceramics is cleaned, the silicon-nickel sol is uniformly coated on the glass surface by dip-coating and pulling method, with a pulling speed of 5 cm / min. After coating, it is dried in a constant-temperature oven at 45 °C for 8 h. Then the sample is put into a temperature-controlled furnace for heat treatment, heated to 850 °C at a rate of 1 °C, held at the final temperature for 4 h, and cooled to room temperature to obtain magnesium aluminosilicate glass-ceramics with a silicon-nickel coating on the surface.

[0084] Example 19

[0085] First, place the glass-ceramics prepared in Example 3 in the graphite mold cavity of the ultra-thin glass heat-bending device, and perform a pressing operation on the glass by the upper and lower molds in the device. Heat-press molding is carried out in a nitrogen atmosphere. At a pressure of 0.6 MPa and a preset molding rate of 14 mm / min, the glass is moved to the heating section, first held at 835 °C for 50 s, then heated to 880 °C and held for 85 s. Then the glass is moved to the bending section, held at 780 °C for 100 s, then moved to the annealing section, held at 870 °C for 120 s, and finally moved to the cooling section, held at 760 °C for 65 s, and cooled naturally to obtain the heat-bent magnesium aluminosilicate glass-ceramics.

[0086] Next, preparation of the silicon-nickel sol: Add 6 g of tetraethyl orthosilicate, 1.5 g of nickel nitrate hexahydrate, 15 mL of deionized water, and 25 mL of ethanol to the reaction flask, stir at 60 °C for 1 h. After stirring evenly, add 1.2 g of hydrochloric acid with a mass fraction of 36%, and continue to stir for 8 h to mix evenly to obtain a transparent silicon-nickel sol.

[0087] Finally, preparation of magnesium aluminosilicate glass-ceramics with a silicon-nickel coating on the surface: After the surface of the heat-bent magnesium aluminosilicate glass-ceramics is cleaned, the silicon-nickel sol is uniformly coated on the glass surface by dip-coating and pulling method, with a pulling speed of 6 cm / min. After coating, it is dried in a constant-temperature oven at 50 °C for 7 h. Then the sample is put into a temperature-controlled furnace for heat treatment, heated to 900 °C at a rate of 0.5 °C, held at the final temperature for 3 h, and cooled to room temperature to obtain magnesium aluminosilicate glass-ceramics with a silicon-nickel coating on the surface.

[0088] Example 20

[0089] First, place the glass-ceramics prepared in Example 4 into the graphite mold cavity of the ultra-thin glass hot bending device. Press the glass with the upper and lower molds in the device, and perform hot pressing molding under a nitrogen atmosphere. Under a pressure of 0.6 MPa and a preset molding rate of 12 mm / min, move the glass to the heating section. First, keep it at 805 °C for 60 s, then raise the temperature to 900 °C and keep it for 75 s. Then move the glass to the bending section, keep it at 800 °C for 95 s, then move the glass to the annealing section, keep it at 860 °C for 100 s, and finally move it to the cooling section, keep it at 780 °C for 65 s, and cool it naturally to obtain the hot-bent magnesium-aluminum-silicon glass-ceramics.

[0090] Next, preparation of the silicon-nickel sol: Add 8 g of tetraethyl orthosilicate, 2.0 g of nickel nitrate hexahydrate, 20 mL of deionized water, and 30 mL of ethanol to a reaction flask. Stir at 50 °C for 0.5 h. After stirring evenly, then add 1.2 g of hydrochloric acid with a mass fraction of 38%, and continue to stir for 12 h to mix evenly to obtain a transparent silicon-nickel sol.

[0091] Finally, preparation of the magnesium-aluminum-silicon glass-ceramics with a silicon-nickel coating on the surface: After the surface of the hot-bent magnesium-aluminum-silicon glass-ceramics is cleaned, use the dip-coating and pulling method to evenly coat the silicon-nickel sol on the glass surface. The pulling speed is 10 cm / min. After coating, dry it in a constant-temperature oven at 60 °C for 6 h. Then place the sample in a temperature-controlled furnace for heat treatment, raise the temperature to 890 °C at a rate of 0.5 °C, keep it at the final temperature for 5 h, and cool it to room temperature to obtain the magnesium-aluminum-silicon glass-ceramics with a silicon-nickel coating on the surface.

[0092] Example 21

[0093] First, place the glass-ceramics prepared in Example 5 into the graphite mold cavity of the ultra-thin glass hot bending device. Press the glass with the upper and lower molds in the device, and perform hot pressing molding under a nitrogen atmosphere. Under a pressure of 0.2 MPa and a preset molding rate of 15 mm / min, move the glass to the heating section. First, keep it at 820 °C for 55 s, then raise the temperature to 850 °C and keep it for 80 s. Then move the glass to the bending section, keep it at 790 °C for 95 s, then move the glass to the annealing section, keep it at 860 °C for 115 s, and finally move it to the cooling section, keep it at 800 °C for 60 s, and cool it naturally to obtain the hot-bent magnesium-aluminum-silicon glass-ceramics.

[0094] Next, preparation of the silicon-nickel sol: Add 10 g of tetraethyl orthosilicate, 2.5 g of nickel nitrate hexahydrate, 25 mL of deionized water, and 35 mL of ethanol to a reaction flask. Stir at 50 °C for 1 h. After stirring evenly, then add 1.5 g of hydrochloric acid with a mass fraction of 37%, and continue to stir for 8 h to mix evenly to obtain a transparent silicon-nickel sol.

[0095] Finally, the preparation of magnesium aluminosilicate glass-ceramics with a silicon-nickel coating on the surface: After the surface of the heat-bent magnesium aluminosilicate glass-ceramics is cleaned, the silicon-nickel sol is uniformly coated on the glass surface by dip-coating and pulling method, the pulling speed is 5 cm / min, and after coating, it is dried in a constant temperature oven at 40 °C for 7 h. Then the sample is put into a temperature-controlled furnace for heat treatment, heated to 800 °C at a rate of 1 °C, held at the final temperature for 3 h, and cooled to room temperature to obtain magnesium aluminosilicate glass-ceramics with a silicon-nickel coating on the surface.

[0096] Table 3 Test table of magnesium aluminosilicate glass-ceramics with a silicon-nickel coating on the surface <![CDATA[Vickers hardness (kgf / mm 2 ).]]> Example 17 764 Example 18 761 Example 19 758 Example 20 750 Example 21 735 From the data in the above table, it can be seen that as the silicon-nickel content of the surface coating of magnesium aluminosilicate glass-ceramics increases, the bending strength of the glass is greatly improved, and that of Example 17 reaches 764 kgf / mm 2 , indicating that the 3D heat-bending process can significantly improve the strength of the glass. Then, with the silicon-nickel coating prepared by the sol-gel method, during the subsequent heat treatment process, after the silica gelation is heat-treated, it bonds with the silicon-oxygen bonds inside the glass, making the whole structure more firm. At the same time, the sol forms a dense coating on the glass surface, repairing the broken and dangling bonds on the surface, and greatly improving both the bending strength and corrosion resistance.

[0097] Although the embodiments of the present invention have been described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A magnesium-aluminum-silicon microcrystalline glass, characterized in that, Its crystal phase content is not less than 20%; it contains MgAl 2 Si 3 O 10 、MgAl 2 Si 4 O 12 、Mg 2 Al 4 Si 5 O 18 one or more of the crystal phases; the average grain size is less than or equal to 50 nm; in the visible light wavelength range, its light transmittance ≥ 80%.

2. The magnesium-aluminum-silicon microcrystalline glass according to claim 1, characterized in that, Its Vickers hardness ≥ 700 kgf / mm 2 .

3. The microcrystalline glass according to claim 1, characterized in that, The main crystal phase composition is MgAl 2 Si 3 O 10 or MgAl 2 Si 4 O 12 or MgAl 2 Si 3 O 10 and MgAl 2 Si 4 O 12 When this is the case, the crystallinity of the glass-ceramics is ≥ 60%.

4. A preparation method of the magnesium-aluminum-silicon microcrystalline glass as claimed in claim 1, characterized in that, the preparation of the magnesium-aluminum-silicon microcrystalline glass is carried out according to the following steps: (1)Preparation of glass batch: Weigh 50 - 62 parts by weight of glass component SiO 2 , 25 - 32 parts of Al 2 O 3 , 5 - 10 parts of MgO, 1.5 - 2.5 parts of LiO 2 and 3 - 8 parts of ZrO 2 . After fully grinding and mixing evenly, pass through a 50 - 100 mesh sieve to obtain the glass batch; (2) Preparation of magnesium-aluminum-silicon microcrystalline glass: Using a silicon carbide rod electric furnace, melting the glass mixture in step (1) at 1300 - 1600 °C for 2 - 4 h. After the glass liquid is completely melted, pour it onto a preheated stainless steel mold. After forming, place the sample in a muffle furnace at 500 - 700 °C for heat preservation for 50 - 90 min for annealing treatment. Then put the obtained base glass into the muffle furnace, raise the temperature to 750 - 850 °C at a heating rate of 3 - 6 °C / min for heat preservation for 2 - 4 h for nucleation treatment, and then raise the temperature to 800 - 1100 °C at a heating rate of 6 - 10 °C / min for heat preservation for 3 - 6 h for crystallization treatment. Then cool it to room temperature to obtain the target magnesium-aluminum-silicon microcrystalline glass.

5. The preparation method of the magnesium-aluminum-silicon microcrystalline glass according to claim 4, characterized in that, The mixture in the said step 1 further contains 0 - 5 parts of P 2 O 5 , 0 - 0.5 parts of SrO, 0 - 0.5 parts of BaO, 0 - 0.5 parts of Na 2 O, 0 - 0.5 parts of K 2 O, 0 - 0.5 parts of CaO, 0 - 5 parts of B 2 O 3 , 0 - 4 parts of Y 2 O 3 , 0 - 1 part of Sb 2 O 3 .

6. The preparation method of the magnesium-aluminum-silicon microcrystalline glass according to claim 5, characterized in that, In the step 1, the mass ratio of MgO / (MgO + CaO + SrO + BaO) is 0.87 - 1; Li 2 O / Li 2 O + Na 2 O + K 2 The mass ratio of O is 0.86 - 1.

7. The preparation method of the magnesium-aluminum-silicon microcrystalline glass according to claim 4, characterized in that, It further includes step (3) preparation of heat-bent magnesium-aluminum-silicon microcrystalline glass: Place the base microcrystalline glass in step (2) in the graphite mold cavity of an ultra-thin glass heat-bending device, and perform a pressurizing operation on the glass by the upper and lower molds in the device. Carry out hot pressing and forming under a nitrogen atmosphere. At a certain preset molding rate, move the glass to the heating section, first keep it at 700 - 850 °C for heat preservation for 60 - 180 s, then raise the temperature to 850 - 900 °C for heat preservation for 60 - 180 s, then move the glass to the bending section, keep it at 750 - 880 °C for heat preservation for 60 - 180 s, then move the glass to the annealing section, keep it at 820 - 870 °C for heat preservation for 60 - 180 s, and finally move it to the cooling section, keep it at 750 - 800 °C for heat preservation for 60 - 180 s, and cool it naturally to obtain the heat-bent magnesium-aluminum-silicon microcrystalline glass.

8. The preparation method of the magnesium-aluminum-silicon microcrystalline glass according to claim 7, characterized in that, the preset pressure in step (3) is 0.2 - 0.9 MPa, and the preset molding rate is 10 - 15 mm / min.

Images