A glass-ceramic based on a synchronized crystallization and chemical strengthening process, and a method for its production and use

Abstract

The application provides a glass-ceramic based on a synchronous crystallization and chemical strengthening process and a preparation method and application thereof, and the preparation method of the glass-ceramic based on the synchronous crystallization and chemical strengthening process comprises the following steps: formula design, preparation of a mixture, melting, forming, annealing, slicing, CNC processing, and synchronous chemical strengthening and crystallization. In the application, the base glass after annealing has no crystal in the interior, the glass strength is low, and the glass is easy to cut, so that the yield of the final product can be ensured. Compared with the preparation method of the glass-ceramic in the traditional crystallization and chemical strengthening process, the chemical strengthening process and the crystallization process are combined in the application, so that the two processes are completed at the same time, the process flow is greatly shortened, and the work efficiency is greatly improved. Meanwhile, the crystallization process of the glass-ceramic in the application is carried out in a salt bath, the temperature is more uniform, and the crystallization process of the glass-ceramic is more favorable.

Description

Technical Field

[0001] This invention relates to the field of glass technology, and in particular to a microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, its preparation method, and its application. Background Technology

[0002] Due to its significant mechanical properties, microcrystalline glass can be used as a cover glass for mobile phone displays. For example, Huawei Mate 60 and Huawei P60 series mobile phones both use transparent microcrystalline glass as cover glass. Other major domestic manufacturers such as Vivo, Oppo, and Xiaomi are also looking for suitable transparent microcrystalline glass to improve the performance of their products.

[0003] The traditional manufacturing process for microcrystalline glass is as follows: formula design → batch preparation → melting → calendering or casting → annealing → crystallization → slicing → CNC machining → chemical strengthening. However, the thickness of display cover glass is relatively thin, typically 0.33mm, 0.5mm, 0.55mm, 0.6mm, 0.7mm, 1.1mm, 3-8mm, etc. The calendering process in traditional microcrystalline glass manufacturing cannot achieve such thin thicknesses in a single step. Therefore, the glass needs to be prepared into glass ingots or glass sheets, and then cut to the target size using wire cutting. However, after crystallization, microcrystalline glass has high hardness and mechanical properties, making cutting difficult and resulting in a low yield. Summary of the Invention

[0004] This invention addresses the problems of high hardness and mechanical properties, high cutting difficulty, and low yield of existing microcrystalline glass after crystallization. It provides a method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, along with its applications. In this invention's preparation method, the base glass after annealing has low strength due to the absence of internal crystals, making it easier to cut and ensuring a high yield of the final product. Furthermore, traditional methods for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening require two heating processes. This invention employs high-temperature chemical strengthening, combining the chemical strengthening process with the crystallization step, allowing both steps to be completed simultaneously, significantly improving efficiency and shortening the process flow. Moreover, compared to traditional microcrystalline glass crystallization processes that rely on air heat transfer for crystal growth, the crystallization process in this invention is conducted in a salt bath, resulting in better temperature uniformity and promoting a more favorable crystallization process.

[0005] The technical solution adopted in this invention is:

[0006] A method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes includes the following steps:

[0007] Step S1: Weigh and mix the raw materials containing SiO2, Al2O3 and Na2O to obtain the base material;

[0008] Step S2: The base material obtained in step S1 is heated to gradually melt it, and after clarification, glass melt is obtained.

[0009] Step S3: The molten glass obtained in step S2 is formed into base glass using either a rolling or casting method.

[0010] Step S4: Anneal the base glass obtained in step S3;

[0011] Step S5: First, slice the base glass obtained in step S4 as needed, then CNC process it to the required size to obtain glass sheets, and then polish and clean the processed glass sheets in sequence.

[0012] In step S6, the glass sheet obtained in step S5 is placed in a salt bath for simultaneous chemical strengthening and crystallization to obtain microcrystalline glass.

[0013] Furthermore, the mass fractions of each component in the raw material are as follows: SiO2, 40~80wt%; Al2O3, 2~30wt%; Na2O, 0.1~5wt%; P2O5, 0~5wt%; ZrO2, 0~10wt%; Li2O, 0~15wt%; MgO, 0~10wt%; B2O3, 0~5wt%; SnO2, 0~5wt%; ZnO, 0~10wt%.

[0014] Furthermore, in step S2, the melting temperature of the base material is 1500–1650°C, and the melting and holding time is 2–12 hours.

[0015] Furthermore, in step S4, the annealing temperature of the base glass is 450~650℃, and the annealing time is 90~150min.

[0016] Furthermore, the salt in the salt bath in step S6 is a mixture of sodium sulfate and potassium sulfate.

[0017] Furthermore, in step S6, the temperature for simultaneous chemical strengthening and crystallization is T1±10℃, and the time for simultaneous chemical strengthening and crystallization is 0.5~12h;

[0018] in, ;

[0019] a1 = Molar percentage of sodium sulfate in the salt bath * 884;

[0020] b1 = Molar percentage of potassium sulfate in the salt bath * 1067;

[0021] c1 = Molar percentage of potassium sulfate in the salt bath * 884;

[0022] d1 = Molar percentage of sodium sulfate in the salt bath * 1067;

[0023] x1 = 0.5033;

[0024] y1=1.0731.

[0025] In this invention, the calculation formula for T1 is innovatively designed through the integration and summarization of a large amount of previous experimental data (melting point of salt, molar percentage of salt, and actual temperatures for simultaneous chemical strengthening and crystallization), thereby deriving coefficients x1 and y1, which serve as key parameters for subsequent salt bath temperature adjustments. During subsequent salt bath temperature adjustments, the theoretical temperatures for simultaneous chemical strengthening and crystallization can be calculated based on the melting point of salt, molar percentage of salt, and coefficients x1 and y1 for selection and use.

[0026] Furthermore, the salt in the salt bath in step S6 is a mixture of potassium chloride and potassium sulfate.

[0027] Further, in step S6, the temperature for simultaneous chemical strengthening and crystallization is T2±10℃, and the time for simultaneous chemical strengthening and crystallization is 0.5~12h; wherein, ;

[0028] a2 = Molar percentage of potassium chloride in the salt bath * 770;

[0029] b2 = Molar percentage of potassium sulfate in the salt bath * 1067;

[0030] c2 = Molar percentage of potassium sulfate in the salt bath * 770;

[0031] d2 = (Molar percentage of potassium chloride in the salt bath) * 1067;

[0032] x2 = 0.5389;

[0033] y2=1.0449.

[0034] The calculation formula for T2 in this invention is innovatively designed through the integration and summarization of a large amount of experimental data (melting point of salt, molar percentage of salt, and actual temperatures for simultaneous chemical strengthening and crystallization), thereby deriving coefficients x2 and y2, which serve as key parameters for subsequent salt bath temperature adjustments. During subsequent salt bath temperature adjustments, the theoretical temperatures for simultaneous chemical strengthening and crystallization can be calculated based on the melting point of salt, the molar percentage of salt, and coefficients x2 and y2 for selection.

[0035] Based on the same inventive concept, the present invention also provides a microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, which is prepared by the aforementioned method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes.

[0036] Based on the same inventive concept, the present invention also provides an application of microcrystalline glass based on synchronous crystallization and chemical strengthening processes, using the aforementioned microcrystalline glass as a display cover or back panel of an electronic terminal.

[0037] The beneficial effects of this invention are:

[0038] This invention provides a microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, its preparation method, and its application. The preparation method for microcrystalline glass based on simultaneous crystallization and chemical strengthening processes is as follows: formula design → batch preparation → melting → molding → annealing → slicing → CNC machining → simultaneous chemical strengthening and crystallization. On one hand, in the preparation method of this invention, the base glass after annealing has lower strength due to the absence of internal crystals, making it easier to cut and ensuring a higher yield of the final product. On the other hand, traditional microcrystalline glass preparation methods require two heating processes, while this invention uses high-temperature chemical strengthening and combines the chemical strengthening process with the crystallization process, allowing both processes to be completed simultaneously, greatly improving work efficiency and significantly shortening the process flow. Furthermore, compared to the traditional microcrystalline glass crystallization process that uses air heat transfer to grow crystals, the crystallization process in this invention is carried out in a salt bath, resulting in better temperature uniformity and further promoting the crystallization process of microcrystalline glass. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 The XRD results are those of the microcrystalline glass in Example 1 before and after undergoing simultaneous chemical strengthening and crystallization.

[0041] Figure 2 This is a distribution diagram of surface stress data of the microcrystalline glass tested using an SLP-2000 scattered photoelastic stress meter after synchronous chemical strengthening and crystallization in Example 1.

[0042] Figure 3 The XRD results are shown for the microcrystalline glass in Example 2 before and after undergoing simultaneous chemical strengthening and crystallization.

[0043] Figure 4 This is a distribution diagram of surface stress data of the microcrystalline glass tested using an SLP-2000 scattered photoelastic stress meter after synchronous chemical strengthening and crystallization in Example 2.

[0044] Figure 5The XRD results are shown for the microcrystalline glass in Example 3 before and after undergoing simultaneous chemical strengthening and crystallization.

[0045] Figure 6 This is a distribution diagram of surface stress data of the microcrystalline glass tested using an SLP-2000 scattered photoelastic stress meter after synchronous chemical strengthening and crystallization in Example 3.

[0046] Figure 7 The XRD results are shown for the microcrystalline glass in Example 4 before and after undergoing simultaneous chemical strengthening and crystallization.

[0047] Figure 8 This is a distribution diagram of surface stress data of the microcrystalline glass tested using an SLP-2000 scattered photoelastic stress meter after synchronous chemical strengthening and crystallization in Example 4. Detailed Implementation

[0048] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0049] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit the present invention.

[0050] The embodiments of the invention will now be described in detail with reference to the accompanying drawings.

[0051] Example 1

[0052] A method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, the process is as follows:

[0053] Step S1: Weigh and mix the raw materials containing SiO2, Al2O3, and Na2O to obtain the base material; wherein, the mass fraction of each component of the raw material is: SiO2, 71wt%; Al2O3, 6.89wt%; Na2O, 0.3wt%; P2O5, 2.65wt%; ZrO2, 6.55wt%; Li2O, 12.61wt%.

[0054] Step S2 involves heating the base material obtained in step S1 to gradually melt it, and after clarification, obtaining molten glass. The melting temperature is 1580℃, and the melting time is 3 hours.

[0055] Step S3: The molten glass obtained in step S2 is formed into base glass using a casting method.

[0056] Step S4: Anneal the base glass obtained in step S3. The annealing temperature is 630℃ and the annealing time is 2 hours.

[0057] Step S5: First, slice the base glass obtained in step S4 as needed, then CNC process it to the required size to obtain glass sheets, and then polish and clean the processed glass sheets in sequence.

[0058] In step S6, the glass slide obtained in step S5 is placed in a salt bath for simultaneous chemical strengthening and crystallization to obtain microcrystalline glass. The salt in the salt bath consists of potassium chloride and potassium sulfate in a molar ratio of 55:45, and T2 is calculated to be 730℃. The temperature for chemical strengthening and crystallization of the glass slide in the salt bath is 725℃, and the time is 2 hours.

[0059] In Example 1, the Vickers hardness of the base glass after annealing in step S4 is 550 kgf / mm. 2 The Vickers hardness of the microcrystalline glass prepared in step S6 is 850 kgf / mm. 2 The base glass has a relatively low hardness, making it easier to slice and process, resulting in a higher yield.

[0060] The XRD results of the microcrystalline glass in Example 1 before and after simultaneous chemical strengthening and crystallization are attached. Figure 1 As shown in the image. (Attached) Figure 1 The black curve represents the curves before simultaneous chemical strengthening and crystallization, indicating that the glass-ceramic was in an amorphous state before simultaneous chemical strengthening and crystallization. (See attached image.) Figure 1 The red curve in the middle represents the curve after simultaneous chemical strengthening and crystallization. The results show that obvious crystal diffraction peaks appeared inside the glass-ceramic, and the main crystalline phase was lithium disilicate, proving that the glass-ceramic completed the transformation from amorphous to crystalline state in the salt bath.

[0061] Appendix Figure 2 This is a distribution map of surface stress data for the microcrystalline glass in Example 1, measured using an SLP-2000 scattered photoelastic stress analyzer after simultaneous chemical strengthening and crystallization. (See attached image.) Figure 2It can be seen that the surface stress CS of the glass-ceramic is 250.80 MPa; and the stress gradually decreases with the increase of ion diffusion depth, with an ion exchange depth of 107.35 μm. The above test data prove that the surface of the glass-ceramic prepared by the preparation method in this embodiment generates compressive stress.

[0062] Based on the two sets of test data above, it can be seen that the microcrystalline glass prepared by the preparation method in this embodiment not only completed ion exchange during the simultaneous chemical strengthening and crystallization process, resulting in compressive stress on the surface, but also completed the crystallization process of the microcrystalline glass.

[0063] Traditional glass-ceramic strengthening requires nucleation in air for approximately 4 hours, followed by crystallization for approximately 5 hours. After crystallization, chemical strengthening is then performed for more than 5 hours. Generally, the entire process takes 29 hours (3 hours to nucleation + 4 hours of nucleation holding + 1 hour to crystallization + 5 hours of crystallization holding + 10 hours of cooling + 5 hours of chemical strengthening + 1 hour of cooling). However, Example 1 requires only 11 hours (4 hours of simultaneous chemical strengthening and crystallization + 2 hours of simultaneous chemical strengthening and crystallization holding + 5 hours of cooling), significantly reducing the process time. Furthermore, the glass-ceramic preparation method based on simultaneous crystallization and chemical strengthening in this example eliminates the complex traditional heat treatment process, combining crystallization heat treatment and chemical strengthening into a single step, greatly shortening the process flow. Finally, the traditional microcrystalline glass crystallization process uses air heat transfer to grow crystals, but the temperature uniformity of this process is far inferior to that using salt bath heat transfer, which is more conducive to the crystallization process of microcrystalline glass. This embodiment effectively integrates the key crystallization heat treatment and chemical strengthening technologies of microcrystalline glass, enabling the above two processes to be completed simultaneously, greatly improving work efficiency.

[0064] The microcrystalline glass prepared by the method in this embodiment can be used as a display cover or backplate for electronic terminals (such as mobile phones, tablets, etc.).

[0065] Example 2

[0066] A method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, the process is as follows:

[0067] Step S1: Weigh and mix the raw materials containing SiO2, Al2O3, and Na2O to obtain the base material; wherein the mass fraction of each component of the raw material is: SiO2, 43.18wt%; Al2O3, 26.74wt%; MgO, 6.98wt%; Na2O, 3.32wt%; B2O3, 2.65wt%; ZrO2, 5.05wt%; SnO2, 3.78wt%; ZnO, 8.3wt%.

[0068] Step S2 involves heating the base material obtained in step S1 to gradually melt it, and after clarification, obtaining molten glass. The melting temperature is 1620℃, and the melting time is 3 hours.

[0069] Step S3: The molten glass obtained in step S2 is formed into base glass using a casting method.

[0070] Step S4: Anneal the base glass obtained in step S3. The annealing temperature is 630℃ and the annealing time is 2 hours.

[0071] Step S5: First, slice the base glass obtained in step S4 as needed, then CNC process it to the required size to obtain glass sheets, and then polish and clean the processed glass sheets in sequence.

[0072] In step S6, the glass slide obtained in step S5 is placed in a salt bath for simultaneous chemical strengthening and crystallization to obtain microcrystalline glass. The salt in the salt bath consists of potassium chloride and potassium sulfate in a molar ratio of 31:69, and T2 is calculated to be 898℃. The temperature for chemical strengthening and crystallization of the glass slide in the salt bath is 900℃, and the time is 1 hour.

[0073] In Example 2, the Vickers hardness of the base glass after annealing in step S4 is 678 kgf / mm. 2 The Vickers hardness of the microcrystalline glass prepared in step S6 is 908 kgf / mm. 2 The base glass has a relatively low hardness, making it easier to slice and process, resulting in a higher yield.

[0074] The XRD results of the microcrystalline glass in Example 2 before and after simultaneous chemical strengthening and crystallization are attached. Figure 3 As shown in the image. (Attached) Figure 3 The black curve represents the curves before simultaneous chemical strengthening and crystallization, indicating that the glass-ceramic was in an amorphous state before simultaneous chemical strengthening and crystallization. (See attached image.) Figure 3 The red curve in the middle represents the curve after simultaneous chemical strengthening and crystallization. The results show that obvious crystal diffraction peaks appeared inside the glass-ceramic, and the main crystalline phase was spinel, proving that the glass-ceramic completed the transformation from amorphous to crystalline state in the salt bath.

[0075] Appendix Figure 4 This is a distribution map of surface stress data for the microcrystalline glass after simultaneous chemical strengthening and crystallization, measured using an SLP-2000 scattered photoelastic stress analyzer, as shown in Example 2. (From Appendix) Figure 4It can be seen that the surface stress CS of the glass-ceramic is 163.63 MPa; and the stress gradually decreases with the increase of ion diffusion depth, with an ion exchange depth of 61.39 μm. The above test data prove that the surface of the glass-ceramic prepared by the preparation method in this embodiment generates compressive stress.

[0076] Based on the two sets of test data above, it can be seen that the microcrystalline glass prepared by the preparation method in this embodiment not only completed ion exchange during the simultaneous chemical strengthening and crystallization process, resulting in compressive stress on the surface, but also completed the crystallization process of the microcrystalline glass.

[0077] Based on the two sets of test data above, it can be seen that the microcrystalline glass prepared by the preparation method in this embodiment not only completed ion exchange during the simultaneous chemical strengthening and crystallization process, resulting in compressive stress on the surface, but also completed the crystallization process of the microcrystalline glass.

[0078] Traditional glass-ceramic strengthening requires nucleation in air for approximately 4 hours, followed by crystallization for about 2 hours. After crystallization, chemical strengthening is then performed for more than 5 hours. Generally, the entire process takes 29 hours (4 hours to nucleation + 4 hours of nucleation holding + 3 hours to crystallization + 2 hours of crystallization holding + 10 hours of cooling + 5 hours of chemical strengthening + 1 hour of cooling). In contrast, Example 2 requires only 14 hours (5 hours of simultaneous chemical strengthening and crystallization + 1 hour of simultaneous chemical strengthening and crystallization holding + 8 hours of cooling), significantly reducing the process time. Furthermore, the glass-ceramic preparation method based on simultaneous crystallization and chemical strengthening in this example eliminates the complex traditional heat treatment process, combining crystallization heat treatment and chemical strengthening into a single step, greatly shortening the process flow. Finally, the traditional microcrystalline glass crystallization process uses air heat transfer to grow crystals, but the temperature uniformity of this process is far inferior to that using salt bath heat transfer, which is more conducive to the crystallization process of microcrystalline glass. This embodiment effectively integrates the key crystallization heat treatment and chemical strengthening technologies of microcrystalline glass, enabling the above two processes to be completed simultaneously, greatly improving work efficiency.

[0079] The microcrystalline glass prepared by the method in this embodiment can be used as a display cover or backplate for electronic terminals (such as mobile phones, tablets, etc.).

[0080] Example 3

[0081] A method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, the process is as follows:

[0082] Step S1: Weigh and mix the raw materials containing SiO2, Al2O3, and Na2O to obtain the base material; wherein the mass fraction of each component of the raw material is: SiO2, 75.46wt%; Al2O3, 5.99wt%; Na2O, 1.3wt%; P2O5, 2.08wt%; ZrO2, 6.42wt%; ZnO, 3.43wt%; Li2O, 5.32wt%.

[0083] Step S2 involves heating the base material obtained in step S1 to gradually melt it, and after clarification, obtaining molten glass. The melting temperature is 1550℃, and the melting time is 3 hours.

[0084] Step S3: The molten glass obtained in step S2 is formed into base glass using a casting method.

[0085] Step S4: Anneal the base glass obtained in step S3. The annealing temperature is 630℃ and the annealing time is 2 hours.

[0086] Step S5: First, slice the base glass obtained in step S4 as needed, then CNC process it to the required size to obtain glass sheets, and then polish and clean the processed glass sheets in sequence.

[0087] In step S6, the glass slide obtained in step S5 is placed in a salt bath for simultaneous chemical strengthening and crystallization to obtain microcrystalline glass. The salt in the salt bath consists of potassium chloride and potassium sulfate, with a molar ratio of 62:38. The calculated temperature T2 is 681℃. The temperature for chemical strengthening and crystallization of the glass slide in the salt bath is 680℃, and the time is 4 hours.

[0088] In Example 3, the Vickers hardness of the base glass after annealing in step S4 is 605 kgf / mm. 2 The Vickers hardness of the microcrystalline glass prepared in step S6 is 883 kgf / mm. 2 The base glass has a relatively low hardness, making it easier to slice and process, resulting in a higher yield.

[0089] The XRD results of the microcrystalline glass in Example 3 before and after simultaneous chemical strengthening and crystallization are attached. Figure 5 As shown in the image. (Attached) Figure 5 The black curve represents the curves before simultaneous chemical strengthening and crystallization, indicating that the glass-ceramic was in an amorphous state before simultaneous chemical strengthening and crystallization. (See attached image.) Figure 5 The red curve in the middle represents the curve after simultaneous chemical strengthening and crystallization. The results show that obvious crystal diffraction peaks appeared inside the glass-ceramic, and the main crystalline phase was quartz, proving that the glass-ceramic completed the transformation from amorphous to crystalline state in the salt bath.

[0090] Appendix Figure 6This is a distribution map of surface stress data for the microcrystalline glass after simultaneous chemical strengthening and crystallization, measured using an SLP-2000 scattered photoelastic stress analyzer, as shown in Example 3. (From Appendix) Figure 6 It can be seen that the surface stress CS of the glass-ceramic is 162.45 MPa; and the stress gradually decreases with the increase of ion diffusion depth, with an ion exchange depth of 151.32 μm. The above test data prove that the surface of the glass-ceramic prepared by the preparation method in this embodiment generates compressive stress.

[0091] Based on the two sets of test data above, it can be seen that the microcrystalline glass prepared by the preparation method in this embodiment not only completed ion exchange during the simultaneous chemical strengthening and crystallization process, resulting in compressive stress on the surface, but also completed the crystallization process of the microcrystalline glass.

[0092] Based on the two sets of test data above, it can be seen that the microcrystalline glass prepared by the preparation method in this embodiment not only completed ion exchange during the simultaneous chemical strengthening and crystallization process, resulting in compressive stress on the surface, but also completed the crystallization process of the microcrystalline glass.

[0093] Traditional glass-ceramic strengthening requires nucleation in air for approximately 4 hours, followed by crystallization for about 2 hours. After crystallization, chemical strengthening is performed for more than 5 hours. Generally, the entire process takes 22 hours (3 hours to nucleation + 4 hours of nucleation holding + 1 hour to crystallization + 2 hours of crystallization holding + 6 hours of cooling + 5 hours of chemical strengthening + 1 hour of cooling). However, Example 3 requires only 11.5 hours (3.5 hours of simultaneous chemical strengthening and crystallization + 4 hours of simultaneous chemical strengthening and crystallization holding + 4 hours of cooling), significantly reducing the process time. Furthermore, the glass-ceramic preparation method based on simultaneous crystallization and chemical strengthening in this example eliminates the complex traditional heat treatment process, combining crystallization heat treatment and chemical strengthening into a single step, greatly shortening the process flow. Finally, the traditional microcrystalline glass crystallization process uses air heat transfer to grow crystals, but the temperature uniformity of this process is far inferior to that using salt bath heat transfer, which is more conducive to the crystallization process of microcrystalline glass. This embodiment effectively integrates the key crystallization heat treatment and chemical strengthening technologies of microcrystalline glass, enabling the above two processes to be completed simultaneously, greatly improving work efficiency.

[0094] The microcrystalline glass prepared by the method in this embodiment can be used as a display cover or backplate for electronic terminals (such as mobile phones, tablets, etc.).

[0095] Example 4

[0096] A method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, the process is as follows:

[0097] Step S1: Weigh and mix the raw materials containing SiO2, Al2O3, and Na2O to obtain the base material; wherein the mass fraction of each component of the raw material is: SiO2, 66.46wt%; Al2O3, 11.06wt%; Na2O, 8.3wt%; P2O5, 2.36wt%; ZrO2, 4.47wt%; ZnO, 4.05wt%; Li2O, 3.3wt%.

[0098] Step S2 involves heating the base material obtained in step S1 to gradually melt it, and after clarification, obtaining molten glass. The melting temperature is 1600℃, and the melting time is 2.5 hours.

[0099] Step S3: The molten glass obtained in step S2 is formed into base glass using a casting method.

[0100] Step S4: Anneal the base glass obtained in step S3. The annealing temperature is 580℃ and the annealing time is 2 hours.

[0101] Step S5: First, slice the base glass obtained in step S4 as needed, then CNC process it to the required size to obtain glass sheets, and then polish and clean the processed glass sheets in sequence.

[0102] In step S6, the glass slide obtained in step S5 is placed in a salt bath for simultaneous chemical strengthening and crystallization to obtain microcrystalline glass. The salt in the salt bath consists of sodium sulfate and potassium sulfate, with a molar ratio of 53:47. The calculated temperature T2 is 774℃. The temperature for chemical strengthening and crystallization of the glass slide in the salt bath is 770℃, and the time is 3 hours.

[0103] In Example 4, the Vickers hardness of the base glass after annealing in step S4 is 538 kgf / mm. 2 The Vickers hardness of the microcrystalline glass prepared in step S6 is 837 kgf / mm. 2 The base glass has a relatively low hardness, making it easier to slice and process, resulting in a higher yield.

[0104] The XRD results of the microcrystalline glass in Example 4 before and after simultaneous chemical strengthening and crystallization are attached. Figure 7 As shown in the image. (Attached) Figure 7 The black curve represents the curves before simultaneous chemical strengthening and crystallization, indicating that the glass-ceramic was in an amorphous state before simultaneous chemical strengthening and crystallization. (See attached image.) Figure 7 The red curve in the middle represents the curve after simultaneous chemical strengthening and crystallization. The results show that obvious crystal diffraction peaks appeared inside the glass-ceramic, and the main crystalline phase was spodumene, proving that the glass-ceramic completed the transformation from amorphous to crystalline state in the salt bath.

[0105] Appendix Figure 8 This is a distribution map of surface stress data for the microcrystalline glass in Example 4, obtained using an SLP-2000 scattered photoelastic stress analyzer after simultaneous chemical strengthening and crystallization. (From Appendix) Figure 8 It can be seen that the surface stress CS of the glass-ceramic is 247.26 MPa; and the stress gradually decreases with the increase of ion diffusion depth, with an ion exchange depth of 114.96 μm. The above test data prove that the surface of the glass-ceramic prepared by the preparation method in this embodiment generates compressive stress.

[0106] Based on the two sets of test data above, it can be seen that the microcrystalline glass prepared by the preparation method in this embodiment not only completed ion exchange during the simultaneous chemical strengthening and crystallization process, resulting in compressive stress on the surface, but also completed the crystallization process of the microcrystalline glass.

[0107] Traditional glass-ceramic strengthening requires nucleation in air for approximately 4 hours, followed by crystallization for about 2 hours. After crystallization, chemical strengthening is performed for more than 5 hours. Generally, the entire process takes 25 hours (3.5 hours to nucleation + 4 hours for nucleation holding + 1.5 hours to crystallization + 2 hours for crystallization holding + 8 hours for cooling + 5 hours for chemical strengthening + 1 hour for cooling). However, Example 4 requires only 11.5 hours (4.5 hours for simultaneous chemical strengthening and crystallization + 3 hours for simultaneous chemical strengthening and crystallization holding + 4 hours for cooling), significantly reducing the process time. Furthermore, the glass-ceramic preparation method based on simultaneous crystallization and chemical strengthening in this example eliminates the complex traditional heat treatment process, combining crystallization heat treatment and chemical strengthening into a single step, greatly shortening the process flow. Finally, the traditional microcrystalline glass crystallization process uses air heat transfer to grow crystals, but the temperature uniformity of this process is far inferior to that using salt bath heat transfer, which is more conducive to the crystallization process of microcrystalline glass. This embodiment effectively integrates the key crystallization heat treatment and chemical strengthening technologies of microcrystalline glass, enabling the above two processes to be completed simultaneously, greatly improving work efficiency.

[0108] The microcrystalline glass prepared by the method in this embodiment can be used as a display cover or backplate for electronic terminals (such as mobile phones, tablets, etc.).

Claims

1. A method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, characterized in that, Includes the following steps: Step S1: Weigh and mix the raw materials containing SiO2, Al2O3, and Na2O to obtain the base material; wherein the mass fraction of each component of the raw material is: SiO2, 40~80wt%; Al2O3, 2~30wt%; Na2O, 0.1~5wt%; P2O5, 0~5wt%; ZrO2, 0~10wt%; Li2O, 0~15wt%; MgO, 0~10wt%; B2O3, 0~5wt%; SnO2, 0~5wt%; ZnO, 0~10wt%. Step S2: The base material obtained in step S1 is heated to gradually melt it, and after clarification, glass melt is obtained. Step S3: The molten glass obtained in step S2 is formed into base glass using either a rolling or casting method. Step S4: Anneal the base glass obtained in step S3; Step S5: First, slice the base glass obtained in step S4 as needed, then CNC process it to the required size to obtain glass sheets, and then polish and clean the processed glass sheets in sequence. In step S6, the glass sheet obtained in step S5 is placed in a salt bath for simultaneous chemical strengthening and crystallization to obtain microcrystalline glass.

2. The method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes according to claim 1, characterized in that, In step S2, the melting temperature of the base material is 1500–1650℃, and the melting and holding time is 2–12 hours.

3. The method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes according to claim 1, characterized in that, In step S4, the annealing temperature of the base glass is 450~650℃, and the annealing time is 90~150min.

4. The method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes according to any one of claims 1 to 3, characterized in that, The salt in the salt bath during step S6 is a mixture of sodium sulfate and potassium sulfate.

5. The method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes according to claim 4, characterized in that, In step S6, the temperature for simultaneous chemical strengthening and crystallization is T1±10℃, and the time for simultaneous chemical strengthening and crystallization is 0.5~12h. in, ; a1 = Molar percentage of sodium sulfate in the salt bath × 884; b1 = Molar percentage of potassium sulfate in the salt bath × 1067; c1 = Molar percentage of potassium sulfate in the salt bath × 884; d1 = Molar percentage of sodium sulfate in the salt bath × 1067; x1=0.5033； y1=1.0731。 6. The method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes according to any one of claims 1 to 3, characterized in that, In step S6, the salt in the salt bath is a mixture of potassium chloride and potassium sulfate.

7. The method for preparing microcrystalline glass based on simultaneous crystallization and chemical strengthening processes according to claim 6, characterized in that, In step S6, the temperature for simultaneous chemical strengthening and crystallization is T2±10℃, and the time for simultaneous chemical strengthening and crystallization is 0.5~12h; wherein, ; a2 = Molar percentage of potassium chloride in the salt bath × 770; b2 = Molar percentage of potassium sulfate in the salt bath × 1067; c2 = Molar percentage of potassium sulfate in the salt bath × 770; d2 = Molar percentage of potassium chloride in the salt bath × 1067; x2=0.5389； y2=1.0449。 8. A microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, characterized in that, It is prepared by the method for preparing microcrystalline glass based on synchronous crystallization and chemical strengthening processes as described in any one of claims 1 to 7.

9. An application of a microcrystalline glass based on simultaneous crystallization and chemical strengthening processes, characterized in that, The microcrystalline glass based on synchronous crystallization and chemical strengthening processes as described in claim 8 is used as the display cover or back panel of an electronic terminal.

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