Microcrystalline glass and its preparation methods, glass products

Abstract

This application provides a microcrystalline glass, its preparation method, and glass products. The microcrystalline glass comprises the following components by mass percentage: SiO2 54%~68%, Al2O3 15%~24.8%, Li2O 0.5%~4.5%, Na2O 0~1%, MgO 1%~5%, ZnO 1%~5%, CaO 0~1%, BaO 0~3%, TiO2 0.5%~4%, ZrO2 1%~5%, P2O5 0.5%~3%, and La2O3 0.1%~1%. The components of the microcrystalline glass of this application, when combined and synergistically mixed in a specific ratio, can produce a microcrystalline glass with a low coefficient of thermal expansion, excellent mechanical properties, and high visible light transmittance.

Description

Technical Field

[0001] This application relates to the field of glass technology, and in particular to a microcrystalline glass and its preparation method, as well as glass products. Background Technology

[0002] Microcrystalline glass is a new type of building decoration material, mainly composed of silicates. Due to its good chemical stability and mechanical strength, it is widely used in construction, home appliances, automobiles and other fields.

[0003] The main preparation method for microcrystalline glass involves high-temperature melting, molding, and heat treatment to precipitate a large number of tiny crystals inside the glass, thereby improving its strength and hardness. However, traditional microcrystalline glass has a high coefficient of thermal expansion, making it prone to deformation in high-temperature environments, which limits its application in high-temperature scenarios.

[0004] Therefore, further improvements are still needed to the traditional microcrystalline glass. Summary of the Invention

[0005] Based on this, one or more embodiments of this application provide a microcrystalline glass with a low coefficient of thermal expansion and excellent mechanical properties, a method for preparing the same, and glass products thereof.

[0006] According to a first aspect of the embodiments of this application, a microcrystalline glass is provided, comprising, by mass percentage, the following components:

[0007] SiO2 54%~68%, Al2O3 15%~24.8%, Li2O 0.5%~4.5%, Na2O 0~1%, MgO 1%~5%, ZnO 1%~5%, CaO 0~1%, BaO 0~3%, TiO2 0.5%~4%, ZrO2 1%~5%, P2O5 0.5%~3% and La2O3 0.1%~1%.

[0008] In some embodiments, the sum of the mass percentages of TiO2, ZrO2, and P2O5 is a%, and satisfies 5.57 ≤ a ≤ 8.73.

[0009] In some embodiments, the mass percentage of TiO2 is x%, the sum of the mass percentages of ZrO2 and P2O5 is y%, and satisfies 0.1≤x / y≤0.97.

[0010] In some embodiments, the sum of the mass percentages of SiO2, Al2O3, Li2O and La2O3 is m%, the sum of the mass percentages of TiO2, ZrO2 and P2O5 is n%, and satisfies 9.39≤m / n≤15.42.

[0011] In some embodiments, the sum of the mass percentages of MgO, ZnO, CaO and BaO is q%, and the sum of the mass percentages of Na2O and Li2O is p%, satisfying 1.52≤q / p≤5.69.

[0012] In some embodiments, the sum of the mass percentages of MgO and ZnO is b%, the mass percentage of Al2O3 is c%, and the condition 0.21 ≤ b / c ≤ 0.42 is satisfied.

[0013] In some embodiments, the microcrystalline glass satisfies at least one of the following conditions:

[0014] (1) By mass percentage, the microcrystalline glass comprises the following components: SiO2 56%~68%, Al2O3 15.5%~24.8%, Li2O 1.5%~4%, Na2O 0.5%~1%, MgO 1.5%~3.5%, ZnO 1.5%~5%, CaO 0.3%~0.9%, BaO 0~3%, TiO2 1%~4%, ZrO2 1%~4%, P2O5 0.5%~2.4% and La2O3 0.1%~0.9%;

[0015] (2) The main crystalline phase of the glass-ceramic includes one or more of quartz solid solution, spodumene and spinel;

[0016] (3) The crystallinity of the microcrystalline glass is 45%~58%.

[0017] According to a second aspect of the embodiments of this application, a method for preparing microcrystalline glass is provided, comprising the following steps:

[0018] The raw materials are provided according to the above-mentioned components of the microcrystalline glass, and the raw materials are mixed to prepare a mixture;

[0019] The mixture is subjected to melting, shaping, annealing and crystallization processes to obtain the microcrystalline glass.

[0020] In some embodiments, the preparation method satisfies at least one of the following conditions:

[0021] (1) The melting treatment temperature is 1620℃~1660℃ and the time is 4h~8h;

[0022] (2) The molding temperature is 1280℃~1380℃;

[0023] (3) The annealing temperature is 550℃~650℃ and the time is 4h~6h;

[0024] (4) The crystallization treatment temperature is 750℃~900℃ and the time is 1.5h~6h;

[0025] (5) The crystallization process includes: heating to the crystallization temperature at a rate of 2℃ / min to 5℃ / min;

[0026] (6) The crystallization treatment includes the following steps: cooling to room temperature at a rate of 0.5℃ / min to 2℃ / min.

[0027] According to a third aspect of the embodiments of this application, a glass article is provided, including the microcrystalline glass described above or the microcrystalline glass prepared by the above-described method.

[0028] Compared with traditional technologies, this application has the following advantages:

[0029] This application achieves this by rationally designing the chemical composition of the glass-ceramic. SiO2 and Al2O3 are the main components of the glass network structure. Li2O can reduce the high-temperature viscosity of the glass, Na2O can improve the melting performance of the glass, MgO has a fluxing effect, ZnO can reduce the high-temperature viscosity, CaO and BaO can lower the melting temperature of the glass, TiO2 and La2O3 can promote glass crystallization, ZrO2 can improve the crystallization efficiency of the glass, and P2O5 can improve the solubility of the glass components. The above components work together synergistically in the specific proportions of this application, thereby enabling the preparation of a glass-ceramic with a low coefficient of thermal expansion, excellent mechanical properties, and high visible light transmittance. Detailed Implementation

[0030] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in this application are commercially available or can be prepared by existing methods.

[0032] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0033] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0034] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature processing or allow for variation within a certain temperature range. It should be understood that the constant-temperature processing allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0035] Some embodiments of this application provide a microcrystalline glass comprising, by mass percentage, the following components:

[0036] SiO254%~68%, Al2O315%~24.8%, Li2O 0.5%~4.5%, Na2O 0~1%, MgO 1%~5%, ZnO 1%~5%, CaO 0~1%, BaO 0~3%, TiO20.5%~4%, ZrO21%~5%, P2O50.5%~3% and La2O30.1%~1%.

[0037] SiO2 serves as the main structural framework of the glass network and is also the component with the largest proportion in the glass composition. In this application, the mass percentage of SiO2 is 54% to 68%. Within this composition range, the microcrystalline glass has a low coefficient of thermal expansion and moderate glass hardness and high-temperature viscosity.

[0038] In this application, the mass percentage of SiO2 is "54%~68%", which can be the minimum and maximum value of the range 54%~68%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, or 68%; or any range consisting of any two of these values, such as 56.5%~62.5%.

[0039] In some optional examples, the mass percentage of SiO2 is 56% to 68%.

[0040] Al2O3 is an essential component for the formation of glass network structures. After heat treatment, most of it exists as part of the β-quartz solid solution crystalline phase, with a small amount present in the residual glass phase. By controlling the mass percentage of Al2O3 within a specific range, microcrystalline glass with low thermal expansion coefficient and high transparency can be prepared, while also achieving a suitable viscosity.

[0041] In this application, the mass percentage of Al2O3 is "15%~24.8%", which can be the minimum and maximum value of the range of 15%~24.8%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24% or 24.8%; or any range of any two of these values, such as: 16.5%~20.5%.

[0042] In some optional examples, the mass percentage of Al2O3 is 15% to 22%.

[0043] Li2O can reduce the high-temperature viscosity of glass and is also an essential component for the formation of β-quartz solid solution. Controlling its content within a specific range can make the crystallization ability of glass-ceramics moderate and the crystallization process less prone to getting out of control.

[0044] In this application, the mass percentage of Li2O is "0.5%~4.5%", which can be the minimum and maximum value of the range of 0.5%~4.5%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4% or 4.5%; or any range of any two of these values, such as: 2.2%~4.2%.

[0045] In some optional examples, the mass percentage of Li2O is 1.5% to 4%.

[0046] The addition of Na2O can improve the melting performance of glass-ceramics, but it will increase the proportion of residual glass phase in the glass-ceramics, increase the coefficient of thermal expansion, and may cause the product to become hazy; therefore, its mass percentage needs to be controlled within a specific range in order to achieve the purpose of improving the glass melting performance.

[0047] In this application, the mass percentage of Na2O is "0~1%", which can be the minimum and maximum value of the range 0~1%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%; or any range of any two of these values, such as 0.4%~0.8%.

[0048] In some optional examples, the mass percentage of Na2O is 0.5% to 1%.

[0049] MgO has a certain fluxing effect under high temperature conditions, and can also reduce the tendency and rate of crystallization, thereby improving the chemical stability and mechanical strength of glass.

[0050] In this application, the mass percentage of MgO is "1%~5%", which can be the minimum and maximum value of the range of 1%~5%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%; or any range of any two of these values, such as: 0.4%~4.4%.

[0051] In some optional examples, the mass percentage of MgO is 1.5% to 3.5%.

[0052] ZnO has the effect of reducing viscosity at high temperatures and increasing viscosity at low temperatures. Simultaneously, ZnO can reduce the CTE of glass and improve its chemical and thermal stability. In this application, the mass percentage of ZnO should not be too high. As the amount of ZnO added increases, the structure becomes increasingly porous, lowering the crystallization activation energy and making the transformation of β-quartz to β-spodumene easier. Furthermore, it causes crystal coarsening, resulting in a white, opaque sample.

[0053] In this application, the mass percentage of ZnO is "1%~5%", which can be the minimum and maximum value of the range of 1%~5%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%; or any range of any two of these values, such as: 0.4%~4.4%.

[0054] In some optional examples, the mass percentage of ZnO is 1.5% to 5%.

[0055] CaO can lower the melting temperature of glass-ceramics. During heat treatment, the crystallization rate of the glass decreases with increasing CaO content, while the softening temperature, crystallization temperature, and coefficient of thermal expansion of the glass increase with increasing CaO content. Therefore, the mass percentage of CaO needs to be properly controlled.

[0056] In this application, the mass percentage of CaO is "0~1%", which can be the minimum and maximum value of the range 0~1%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%; or any range of any two of these values, such as 0.3%~0.8%.

[0057] In some optional examples, the mass percentage of CaO is 0.3% to 0.9%.

[0058] BaO can not only lower the melting temperature of glass, but also improve its transparency; however, excessive BaO content may corrode refractory materials.

[0059] In this application, the mass percentage of BaO is "0~3%", which can be the minimum and maximum value of the range 0~3%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, or 3%; or any range consisting of any two of these values, such as 0.5%~2.8%.

[0060] In some optional examples, the mass percentage of BaO is 0% to 2.8%.

[0061] TiO2 can not only promote the crystallization of glass-ceramics and improve the crystallization ability of glass, but also reduce the viscosity of glass systems at high temperatures, thereby improving the melting and processing performance of glass.

[0062] In this application, the mass percentage of TiO2 is "0.5%~4%", which can be the minimum and maximum value of the range of 0.5%~4%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5% or 4%; or any range of any two of these values, such as: 0.5%~3.6%.

[0063] In some optional examples, the mass percentage of TiO2 is 1% to 4%.

[0064] ZrO2 can improve the crystallization efficiency of glass-ceramics and increase the stable temperature range of β-quartz solid solution, which is conducive to the formation of β-quartz solid solution and can prevent the transformation of β-quartz solid solution to β-spodumene solid solution. At the same time, ZrO2 can make the grain distribution in glass-ceramic samples more dispersed, thereby avoiding grain aggregation that leads to increased local stress and easy cracking. In addition, the independently dispersed grains are more likely to fill the defects in the glass, thus making the structure of glass-ceramics more compact and improving the flexural strength.

[0065] In this application, the mass percentage of ZrO2 is "1%~5%", which can be the minimum and maximum value of the range of 1%~5%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%; or any range of any two of these values, such as: 0.8%~4.2%.

[0066] In some optional examples, the mass percentage of ZrO2 is 1% to 4%.

[0067] The addition of P2O5 can significantly improve the solubility of ZrO2, preventing the formation of ZrO2 stones in the matrix glass. Furthermore, P2O5 can combine with Al2O3 to form AlPO4, replacing SiO2, reducing the high-temperature viscosity of the matrix glass, improving its uniformity and formability, while also reducing the tendency of β-quartz solid solution to transform into β-spodumene solid solution and adjusting the CTE of the glass-ceramic.

[0068] In this application, the mass percentage of P2O5 is "0.5%~3%", which can be the minimum and maximum value of the range of 0.5%~3%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5% or 3%; or any range of any two of these values, such as: 0.8%~2.6%.

[0069] In some optional examples, the mass percentage of P2O5 is 0.5% to 2.4%.

[0070] The addition of La2O3 enables microcrystalline glass to block ultraviolet light and reduces the viscosity of molten glass; it also promotes crystallization and weakens the transformation of metastable β-quartz solid solution to stable β-spodumene solid solution.

[0071] In this application, the mass percentage of La2O3 is "0.1%~1%", which can be the minimum and maximum value of the range 0.1%~1%, as well as every value between the minimum and maximum value. Specifically, it includes, but is not limited to, the point values ​​in the embodiments and the following point values: 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%; or any range of any two of these values, such as: 0.25%~0.75%.

[0072] In some optional examples, the mass percentage of La2O3 is 0.1% to 0.9%.

[0073] In some embodiments, the sum of the mass percentages of TiO2, ZrO2, and P2O5 is a%, and satisfies 5.57 ≤ a ≤ 8.73.

[0074] As an example, the value of 'a' can be, but is not limited to, specific values ​​such as 5.57, 5.6, 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, or 8.73.

[0075] In some embodiments, the mass percentage of TiO2 is x%, the sum of the mass percentages of ZrO2 and P2O5 is y%, and satisfies 0.1≤x / y≤0.97.

[0076] As an example, the values ​​of x / y can be, but are not limited to, specific values ​​such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 0.97.

[0077] Understandably, choosing TiO2, ZrO2, and P2O5 as composite nucleating agents can make the crystals of the microcrystalline glass finer, with higher peel strength and better transparency.

[0078] In some embodiments, the sum of the mass percentages of SiO2, Al2O3, Li2O and La2O3 is m%, the sum of the mass percentages of TiO2, ZrO2 and P2O5 is n%, and satisfies 9.39≤m / n≤15.42.

[0079] As an example, the value of m / n can be, but is not limited to, specific values ​​such as 9.39, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, or 15.42.

[0080] Understandably, controlling the value of m / n within the aforementioned specific range enables the glass-ceramic to precipitate a crystalline phase dominated by β-quartz solid solution, and it exhibits low expansion and heat resistance.

[0081] In some embodiments, the sum of the mass percentages of MgO, ZnO, CaO and BaO is q%, and the sum of the mass percentages of Na2O and Li2O is p%, satisfying 1.52≤q / p≤5.69.

[0082] As an example, the value of q / p can be, but is not limited to, specific values ​​such as 1.52, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, or 5.69.

[0083] Understandably, R2O and RO can form a "mixed alkali-alkaline earth effect", which significantly increases the expansion and softening temperature of glass; therefore, controlling the value of q / p within the above-mentioned specific range can achieve better results.

[0084] In some embodiments, the sum of the mass percentages of MgO and ZnO is b%, the mass percentage of Al2O3 is c%, and the condition 0.21 ≤ b / c ≤ 0.42 is met.

[0085] As an example, the values ​​of b / c can be, but are not limited to, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, or 0.42.

[0086] Understandably, adding MgO and ZnO can reduce raw material costs and lower the liquidus temperature, but excessive amounts can cause the precipitation of high CTE crystalline phases such as cordierite and spinel during glass crystallization, affecting the performance of the product.

[0087] In some optional examples, the microcrystalline glass comprises the following components by mass percentage:

[0088] SiO256%~68%, Al2O315.5%~24.8%, Li2O 5%~4%, Na2O 0.5~1%, MgO 5%~3.5%, ZnO5%~5%, CaO 0.3%~0.9%, BaO 0~3%, TiO21%~4%, ZrO21%~4%, P2O50.5%~3% and La2O30.1%~0.9%.

[0089] In some embodiments, the main crystalline phase of the glass-ceramic includes one or more of quartz solid solution, spodumene, and spinel.

[0090] In some embodiments, the crystallinity of the glass-ceramic is 45% to 58%.

[0091] The microcrystalline glass of this application is not easily deformed under high temperature conditions, which improves its application value in high temperature scenarios; moreover, the microcrystalline glass of this application does not require the use of a large amount of scarce resources such as lithium, and the preparation cost is low.

[0092] The softening temperature of the aforementioned microcrystalline glass exceeds 900℃, and its coefficient of thermal expansion is -2.6×10⁻⁶. -7 / ℃~5×10 -7 It has an impact strength of 0.72J and a transmittance of over 86% at ℃. It has the advantages of good heat resistance, low expansion coefficient, high mechanical strength and transparent appearance, and can be used in high-temperature scenarios such as electromagnetic lighting panels and home furnishing panels.

[0093] The microcrystalline glass of this application does not contain toxic and harmful raw materials such as As2O3 and Sb2O3, thus reducing environmental pollution.

[0094] Some embodiments of this application also provide a method for preparing microcrystalline glass, including steps S10 and S20.

[0095] S10: Provide raw materials according to the above-mentioned components of the microcrystalline glass, mix the raw materials, and prepare a mixture.

[0096] S20: The mixture is subjected to melting, shaping, annealing and crystallization to obtain microcrystalline glass.

[0097] In some embodiments, the melting process in S20 is carried out at a temperature of 1620°C to 1660°C for 4 hours to 8 hours. For example, the melting process temperature can be, but is not limited to, specific values ​​such as 1620°C, 1625°C, 1630°C, 1635°C, 1640°C, 1645°C, 1650°C, 1655°C, or 1660°C; the melting process time can be, but is not limited to, 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours.

[0098] This application optimizes and rationally designs the composition of microcrystalline glass, which can effectively reduce its melting temperature, thereby reducing production difficulty and saving production costs.

[0099] In some embodiments, the molding temperature in S20 is 1280°C to 1380°C. As an example, the molding temperature can be, but is not limited to, specific values ​​such as 1280°C, 1290°C, 1300°C, 1310°C, 1320°C, 1330°C, 1340°C, 1350°C, 1360°C, 1370°C, or 1380°C.

[0100] In some embodiments, the annealing temperature in S20 is 550°C to 650°C, and the time is 4h to 6h. As an example, the annealing temperature can be, but is not limited to, specific values ​​such as 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C, or 650°C; the annealing time can be, but is not limited to, specific values ​​such as 4h, 4.5h, 5h, 5.5h, or 6h.

[0101] In some embodiments, the crystallization treatment temperature in S20 is 750°C to 900°C, and the time is 1.5h to 6h. As examples, the crystallization treatment temperature can be, but is not limited to, specific values ​​such as 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C, or 900°C. The crystallization treatment time can be, but is not limited to, specific values ​​such as 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, or 6h.

[0102] In some embodiments, the crystallization process includes: heating from room temperature to the expansion softening temperature at a rate of 7°C / min to 10°C / min; then heating to the crystallization temperature at a rate of 2°C / min to 5°C / min; and cooling to room temperature at a rate of 0.5°C / min to 2°C / min after crystallization.

[0103] This application optimizes the temperature, time, and heating / cooling rates of the crystallization process to enable the glass-ceramic to form a specific crystal structure during crystallization, thereby obtaining glass-ceramic with heat resistance, low expansion, high strength, and transparency.

[0104] Some embodiments of this application also provide a glass article, including the microcrystalline glass described above or the microcrystalline glass prepared by the above-described method.

[0105] Glass products containing the aforementioned microcrystalline glass can be applied in technical fields such as household appliances, building decoration, and automobile manufacturing.

[0106] The present application will be further described below with reference to specific embodiments and comparative examples, but these should not be construed as limiting the scope of protection of the present application. Unless otherwise specified, the raw materials involved in the following specific embodiments are all commercially available, the instruments used are all commercially available, and the processes involved are conventionally selected by those skilled in the art unless otherwise specified.

[0107] Example 1

[0108] (1) Raw material supply: Select ultra-white sand, alumina powder, lithium carbonate, sodium carbonate, magnesium oxide, zinc oxide, calcium oxide, barium oxide, titanium dioxide, zirconium oxide, ammonium dihydrogen phosphate, and lanthanum oxide as raw materials. Weigh the raw materials according to the required component ratio, put them into a mixer for mixing, and prepare a uniform mixture. The mixing time is 30 min and the mixing speed is 500 rpm. The glass component ratio in Example 1 is shown in Table 1.

[0109] (2) Preparation of base glass: Pour the mixture obtained in step (1) into a platinum crucible, place it in a high-temperature furnace, heat it to 1630°C under an inert atmosphere, and hold it for 6 hours to obtain a glass melt; cool the glass melt to 1420°C~1460°C, use a mold to press the glass melt into shape, the forming temperature is 1280°C~1380°C, to obtain a glass sheet; put the glass sheet into an annealing furnace for annealing treatment, the annealing temperature is 550°C~650°C, hold for 5 hours, and cool naturally to room temperature to obtain base glass.

[0110] (3) Preparation of microcrystalline glass: The base glass is placed in a crystallization furnace and crystallization heat treatment is carried out by segmented heating and cooling: the temperature is raised to the crystallization temperature at a heating rate of 2℃ / min~5℃ / min, and the crystallization temperature is 760℃; the temperature is kept at the crystallization temperature for 6 hours, and then cooled to room temperature at a rate of 0.5℃ / min~2℃ / min to obtain microcrystalline glass.

[0111] (4) The crystal phase type and crystallinity of the microcrystalline glass prepared above were tested, and the results are shown in Table 1. At the same time, the coefficient of thermal expansion (50℃~750℃) and softening temperature were determined using a Netzsch DIL402 Expedis Classic thermal expansion instrument; the thermal shock temperature was tested according to the cold and hot shock resistance method specified in 6.2.3 of QB / T 4831-2015; the transmittance of the above microcrystalline glass with a thickness of 4mm was tested using a GBC Crintra2020 UV-Vis spectrophotometer; the Mohs hardness grade was tested according to the Mohs hardness test method specified in 6.5.4 of JC / T872-2000; the maximum ROR force and ROR strength were tested using a Protest PT-307A; and the impact strength was tested and calculated using a Protest PT-706 falling ball impact tester. The performance test results of the microcrystalline glass prepared in Example 1 are shown in Table 1.

[0112] Examples 2-15

[0113] The results are basically the same as in Example 1, except for the component ratios, melting temperature and time, and crystallization temperature and time of the glass-ceramic. Specifically, the glass-ceramic components, process parameters, and performance results of Examples 2-5 are shown in Table 1; those of Examples 6-10 are shown in Table 2; those of Examples 11-15 are shown in Table 3; those of Examples 16-20 are shown in Table 4; and those of Comparative Examples 1-3 are shown in Table 5.

[0114] Table 1

[0115]

[0116] Table 2

[0117]

[0118] Table 3

[0119]

[0120] Table 4

[0121]

[0122] The microcrystalline glass prepared in Examples 1-20 of this application has a softening temperature of over 900°C and a coefficient of thermal expansion of -2.6 × 10⁻⁶. -7 / ℃~5×10 -7 At ℃, the maximum ROR force reaches over 2800N, the ROR strength reaches over 73MPa, the impact strength reaches over 0.72J, and the transmittance reaches over 86%; it has the advantages of good heat resistance, low expansion coefficient, high mechanical strength, and transparent appearance.

[0123] In Example 16, the value of (MgO+ZnO) / Al2O3 is greater than 0.42, and the Mohs hardness of the prepared glass-ceramic is only 6. In Example 18, the value of TiO2 / (ZrO2+P2O5) is greater than 0.97, and the impact strength of the prepared glass-ceramic is only 0.725J. In Example 19, the value of (SiO2+Al2O3+Li2O+La2O3) / (TiO2+ZrO2+P2O5) is greater than 15.42, and the Mohs hardness of the prepared glass-ceramic is only 6. In Example 20, the value of (MgO+ZnO+CaO+BaO) / (Na2O+Li2O) is 6.11, which is greater than 5.69, and the maximum ROR force of the prepared glass-ceramic is only 2785N, the impact strength is only 0.713J, and the thermal shock strength is less than 800℃.

[0124] Table 5

[0125]

[0126] In Comparative Example 1, the Na₂O content was greater than 1%, resulting in a higher coefficient of thermal expansion, a lower softening temperature, and a Mohs hardness of only 5. In Comparative Example 2, the Al₂O₃ content was greater than 24.8%, resulting in a higher coefficient of thermal expansion and a Mohs hardness of only 6. In Comparative Example 3, the ZnO content was greater than 5%, resulting in a higher coefficient of thermal expansion, a lower softening temperature, a lower Mohs hardness, and an impact strength of only 0.714 J.

[0127] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0128] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A microcrystalline glass, characterized in that, By mass percentage, it includes the following components: SiO2 55%~68%, Al2O3 15%~24.8%, Li2O 1%~4.5%, Na2O 0~0.7%, MgO 1%~5%, ZnO 2%~5%, CaO 0.3%~0.9%, BaO 0~2%, TiO2 0.5%~3.5%, ZrO2 1%~5%, P2O5 0.5%~3% and La2O3 0.1%~1%; The sum of the mass percentages of TiO2, ZrO2, and P2O5 is a%, and satisfies 5.57≤a≤8.

73. The mass percentage of TiO2 is x%, and the sum of the mass percentages of ZrO2 and P2O5 is y%, satisfying 0.1≤x / y≤0.97; The sum of the mass percentages of SiO2, Al2O3, Li2O, and La2O3 is m%, and the sum of the mass percentages of TiO2, ZrO2, and P2O5 is n%, satisfying 9.39 ≤ m / n ≤ 15.42; The sum of the mass percentages of MgO, ZnO, CaO, and BaO is q%, and the sum of the mass percentages of Na2O and Li2O is p%, satisfying 1.52≤q / p≤5.69; The sum of the mass percentages of MgO and ZnO is b%, and the mass percentage of Al2O3 is c%, satisfying 0.21≤b / c≤0.

42.

2. The microcrystalline glass according to claim 1, characterized in that, The microcrystalline glass comprises the following components by mass percentage: SiO2 56%~68%, Al2O3 15.5%~24.8%, Li2O 1.5%~4%, Na2O 0.5%~0.7%, MgO 1.5%~3.5%, ZnO 2%~5%, CaO 0.3%~0.9%, BaO 0~2%, TiO2 1%~3.5%, ZrO2 1%~4%, P2O5 0.5%~2.4%, and La2O3 0.1%~0.9%.

3. The microcrystalline glass according to claim 1, characterized in that, The main crystalline phase of the microcrystalline glass includes one or more of quartz solid solution, spodumene, and spinel.

4. The microcrystalline glass according to claim 1, characterized in that, The crystallinity of the microcrystalline glass is 45%~58%.

5. A method for preparing microcrystalline glass, characterized in that, Includes the following steps: The raw materials are provided according to the components of the microcrystalline glass according to any one of claims 1 to 4, and the raw materials are mixed to prepare a mixture; The mixture is subjected to melting, shaping, annealing and crystallization processes to obtain the microcrystalline glass.

6. The method for preparing microcrystalline glass according to claim 5, characterized in that, The preparation method satisfies at least one of the following conditions: (1) The melting treatment temperature is 1620℃~1660℃ and the time is 4h~8h; (2) The molding temperature is 1280℃~1380℃; (3) The annealing temperature is 550℃~650℃ and the time is 4h~6h; (4) The crystallization treatment temperature is 750℃~900℃ and the time is 1.5h~6h; (5) The crystallization process includes: heating to the crystallization temperature at a rate of 2℃ / min to 5℃ / min; (6) The crystallization treatment includes the following steps: cooling to room temperature at a rate of 0.5℃ / min to 2℃ / min.

7. A glass article, characterized in that, This includes the microcrystalline glass as described in any one of claims 1 to 4, or the microcrystalline glass prepared by the method described in any one of claims 5 to 6.

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