A high-strength glass-ceramics and its preparation method and application

Abstract

The present invention discloses a high-strength glass-ceramics and its preparation method and application. The high-strength glass-ceramics is prepared from components including the following mass percentages: 5-10 wt% K2O, 6-12 wt% MgO, 2-8 wt% Li2O, 2-12 wt% B2O3, 2-5 wt% TiO2, 5-10 wt% CaO, 5-10 wt% Na2O, 40-60 wt% SiO2, 5-15 wt% CaF2, and 2-10 wt% Al2O3. The glass-ceramics prepared by the present invention has a compressive strength greater than 900 Mpa and a flexural strength greater than 150 Mpa, effectively solving the problem that traditional glass-ceramics perform poorly in terms of compressive strength and flexural strength. In addition, the formula of the present invention is simple and efficient, providing an ideal solution for large-scale industrial production.

Description

Technical Field

[0001] The present invention belongs to the field of advanced materials, and particularly relates to a high-strength glass-ceramics and its preparation method and application. Background Art

[0002] Glass-ceramics, also known as glass ceramics, are a kind of composite material refined through high-temperature melting, forming, and heat treatment processes, in which the crystal phase and the glass complement each other in the structure. This material is highly regarded for its excellent mechanical strength, adjustable thermal expansion coefficient, excellent thermal shock resistance, corrosion resistance, and low dielectric loss, etc. Thanks to these outstanding properties, glass-ceramics play a key role in multiple industries, including mechanical manufacturing, optical instruments, electronics and microelectronics technology, aerospace, chemical industry, biomedicine, and the construction industry, etc.

[0003] In these application fields, the strength of glass-ceramics is particularly crucial. The higher the strength, the greater the load and pressure the material can withstand, thus being widely used in key industries such as construction, automobile manufacturing, and aerospace. High-strength glass-ceramics not only enhance the wear and corrosion resistance and extend the service life of the material, but also in special environments such as chemical laboratories and ocean engineering, the high-strength characteristics can ensure the long-term stability of the devices.

[0004] In addition, the application of high-strength glass-ceramics in the construction industry is particularly important, and it is commonly used as decorative elements such as curtain walls and ceilings. If the material strength is insufficient, it may lead to structural detachment or breakage, thus triggering safety accidents. Therefore, in the production process of glass-ceramics, ensuring its sufficient strength is a key indicator that cannot be ignored. Nevertheless, the current glass-ceramics on the market still have certain limitations in mechanical strength, which to a certain extent restricts their application scope and restricts the further development of the glass-ceramics industry. To address this issue, future research and development work need to focus on enhancing the strength of glass-ceramics to meet broader industrial demands and promote the in-depth application of this material in various fields.

[0005] Patent CN 108017284 A discloses a high-strength glass-ceramics and its preparation method. The raw materials of the glass-ceramics are proportioned by mass as follows: 120-160 parts of cullet, 60-80 parts of modified quartz powder, 10-20 parts of tremolite, 10-20 parts of mordenite, 15-25 parts of nano-silica, 5-15 parts of brucite fiber, 2-6 parts of sodium borosilicate, 3-5 parts of sodium metasilicate pentahydrate, 2-4 parts of calcium aluminosilicate, 1-10 parts of boron oxide, 1-10 parts of ammonium nitrate, 1-10 parts of cerium dioxide, and 1-3 parts of calcium fluoride. The glass-ceramics is prepared by melting the raw materials, stirring and dissolving, standing and clarifying, pressing and forming, and homogenizing annealing. However, the maximum compressive strength of the glass-ceramics prepared by this invention is only 390.7 Mpa, and the maximum flexural strength is only 48.6 Mpa. Patent CN103803803 B proposes a high-strength glass-ceramics and its preparation method. The raw materials of the glass-ceramics are proportioned by mass as follows: by mass, it consists of the following components: 33-36 parts of silicon dioxide, 9-10 parts of calcium oxide, 10-12 parts of magnesium oxide, 8-12 parts of aluminum oxide, 8-10 parts of aluminum phosphate, 5-6 parts of calcium fluoride, 5-6 parts of zirconium oxide, 5-6 parts of lithium oxide, 0.1-3 parts of bismuth oxide, 1-3 parts of titanium oxide, 1-3 parts of barium oxide, 1-1.5 parts of antimony oxide, 1-1.5 parts of lanthanum oxide, 1-1.5 parts of strontium cerium carbonate, 0.01-0.04 parts of zinc oxide, 0.005-0.01 parts of gold trichloride, 0.01-0.02 parts of tin dioxide, and 0-5% of a cosolvent, 0-2% of a colorant. The raw material formula of this invention is complex, and the compressive strength of the prepared glass-ceramics is only 400-450 Mpa, and the flexural strength is 100-180 Mpa. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a high-strength glass-ceramics and its preparation method and application, so as to overcome the deficiencies of existing products in terms of strength. Traditional high-strength glass-ceramics usually have a compressive strength of no more than 500 Mpa, and their flexural strength is also mediocre. In contrast, the glass-ceramics of the present invention not only maintains the excellent comprehensive properties of the material, but also significantly improves its strength index, thereby broadening the application range and improving safety and reliability. This breakthrough not only responds to the urgent needs of the industrial field for high-performance materials, but also lays a solid foundation for the further development and innovation of glass-ceramics technology.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A high-strength microcrystalline glass is prepared from components including the following mass percentages: 5-10 wt% K2O, 6-12 wt% MgO, 2-8 wt% Li2O, 2-12 wt% B2O3, 2-5 wt% TiO2, 5-10 wt% CaO, 5-10 wt% Na2O, 40-60 wt% SiO2, 5-15 wt% CaF2, and 2-10 wt% Al2O3; the main crystal phase of the high-strength microcrystalline glass is Ca2Si2O7F2, and the secondary crystal phase is Ca2SiO4.

[0009] Preferably, the high-strength microcrystalline glass is prepared from components including the following mass percentages: 5-7 wt% K2O, 6-10 wt% MgO, 2-3 wt% LiO, 4-5 wt% B2O3, 2-5 wt% TiO2, 5-10 wt% CaO, 5-8 wt% Na2O, 45-55 wt% SiO2, 5-15 wt% CaF2, and 3-5 wt% Al2O3.

[0010] The preparation method of the above high-strength microcrystalline glass includes the following steps:

[0011] (1) Weigh each raw material according to the component ratio. After mixing each raw material evenly, carry out melting at 1350-1550 °C to obtain a glass melt; the melting temperature is adjusted according to the characteristics of the raw materials to ensure that the raw materials are fully melted and mixed.

[0012] (2) After the glass melt is annealed at 450-500 °C, transparent glass is obtained. The required size and shape of the glass material are formed during annealing, and annealing can eliminate internal stress.

[0013] (3) The transparent glass is first kept warm for nucleation at 520-630 °C for 2-4 h, and then kept warm for crystallization at 720-860 °C for 1-3 h to obtain the high-strength microcrystalline glass.

[0014] Preferably, in step (1), the method of mixing each raw material evenly is as follows: according to the mass ratio of raw material: grinding medium: absolute ethanol = 1:2:1, load the raw material, grinding medium, and absolute ethanol into a mixing tank, carry out ball milling and mixing for 8-12 h, and then dry at 60-80 °C for 8-12 h. The grinding medium is zirconia balls with a diameter of 1-50 mm.

[0015] Preferably, in step (1), the melting time is 1-4 h.

[0016] Preferably, in step (2), the annealing treatment time is 8-12 h.

[0017] Preferably, in step (3), the transparent glass is first heat-insulated and nucleated at 550-600 °C for 2-4 h, and then heat-insulated and crystallized at 750-850 °C for 1-2 h.

[0018] In the above solution, the K2O, MgO, Li2O, B2O3, TiO2, CaO, Na2O, SiO2, CaF2 and Al2O3 are respectively introduced by potassium carbonate, light magnesium oxide, lithium carbonate, boric acid, titanium dioxide, calcium carbonate, anhydrous sodium carbonate, silicon dioxide, calcium fluoride and aluminum oxide.

[0019] The functions of the components of the present invention are analyzed as follows:

[0020] K2O: As a flux, it can significantly reduce the viscosity of the glass melt, promote melting and forming. It also helps to reduce glass crystallization, enhance uniformity and stability.

[0021] MgO: It can improve chemical stability, resist chemical corrosion, enhance thermal stability, reduce deformation caused by temperature changes, and enhance mechanical strength. At the same time, it also reduces the crystallization tendency and maintains the homogeneity and transparency of the glass.

[0022] Li2O: As a flux, it can reduce the melting temperature, reduce energy consumption, improve chemical stability and mechanical strength. It reduces viscosity, improves fluidity, reduces the crystallization tendency, and maintains the amorphous state.

[0023] B2O3: As a flux, it can reduce the melting temperature, increase fluidity, and facilitate processing and forming. It improves thermal stability, reduces deformation, enhances chemical stability, increases hardness, and reduces the thermal expansion coefficient.

[0024] TiO2: As a nucleating agent, it enhances the network by forming an octahedral structure, improves chemical stability, and reduces ion leaching. It may increase the glass transition temperature, promote the formation of specific crystal phases, such as perovskite structure, improve mechanical strength and hardness, and regulate the crystallization behavior.

[0025] CaO: As a flux, it reduces the melting temperature and promotes melting. It improves chemical stability, enhances mechanical strength and hardness, and regulates viscosity and fluidity.

[0026] Na2O: As a strong flux, it significantly reduces the melting temperature, accelerates melting, and reduces energy consumption. It reduces viscosity, improves fluidity, enhances mechanical strength and impact resistance, and promotes crystal growth in glass-ceramics.

[0027] SiO2: As the main component of the glass, SiO2 constitutes the "skeleton", increases viscosity, controls fluidity, reduces the crystallization tendency, and improves transparency. It improves chemical and thermal stability, reduces deformation, and jointly enhances the structural network with B2O3.

[0028] CaF2: As a nucleating agent, CaF2 can promote crystal growth, affect the microstructure and properties. It reduces the thermal expansion coefficient, improves the mechanical strength and hardness, and reduces crystal defects, enhancing the crystal quality.

[0029] Al2O3: It can significantly improve the mechanical strength and impact resistance, enhance the chemical stability, reduce the thermal expansion coefficient, be suitable for high-temperature and thermal shock products, and improve the thermal stability.

[0030] The applications of the above high-strength glass-ceramics in the fields of electronics and microelectronics, architecture, automotive manufacturing, ocean engineering, and aerospace.

[0031] Compared with the prior art, the beneficial effects of the present invention include:

[0032] (1) The present invention provides a high-strength glass-ceramic material with excellent compressive strength (exceeding 900 Mpa) and flexural strength (exceeding 150 Mpa). This innovative achievement effectively solves the problem that traditional glass-ceramics perform poorly in terms of compressive strength (usually not exceeding 500 Mpa) and flexural strength (generally lower than 130 Mpa).

[0033] (2) The formula of the present invention is simple and efficient, without any toxic or harmful substances. The production process is simple and environmentally friendly, ensuring stability and product consistency. In addition, the present invention is cost-effective, providing an ideal solution for large-scale industrial production. Description of the Drawings

[0034] Figure 1 Comparison photos of the glass before and after crystallization prepared in Example 1.

[0035] Figure 2 Comparison photos of the glass before and after crystallization prepared in Example 2.

[0036] Figure 3 Comparison photos of the glass before and after crystallization prepared in Example 3.

[0037] Figure 4 Comparison photos of the glass before and after crystallization prepared in Example 4.

[0038] Figure 5 Comparison photos of the glass before and after crystallization prepared in Example 5.

[0039] Figure 6 Scanning electron microscope (SEM) images of the glass-ceramic material prepared in Example 1.

[0040] Figure 7 Scanning electron microscope (SEM) images of the glass-ceramic material prepared in Example 2.

[0041] Figure 8 Scanning electron microscope (SEM) image of the glass-ceramic material prepared in Example 3.

[0042] Figure 9 Scanning electron microscope (SEM) image of the glass-ceramic material prepared in Example 4.

[0043] Figure 10 Scanning electron microscope (SEM) image of the glass-ceramic material prepared in Example 5.

[0044] Figure 11 X-ray diffraction pattern (XRD) of the glass-ceramic material prepared in Example 1.

[0045] Figure 12 X-ray diffraction pattern (XRD) of the glass-ceramic material prepared in Example 2.

[0046] Figure 13 X-ray diffraction pattern (XRD) of the glass-ceramic material prepared in Example 3.

[0047] Figure 14 X-ray diffraction pattern (XRD) of the glass-ceramic material prepared in Example 4.

[0048] Figure 15 X-ray diffraction pattern (XRD) of the glass-ceramic material prepared in Example 5.

[0049] Figure 16 Differential scanning calorimetry (DSC) curve of the glass-ceramic material prepared in Example 3 of the figure. Detailed implementation manners

[0050] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0051] The ball milling medium in the embodiments is zirconia balls with a diameter of 1-50 mm. K2O, MgO, Li2O, B2O3, TiO2, CaO, Na2O, SiO2, CaF2 and Al2O3 in the embodiments are respectively introduced by potassium carbonate, light magnesium oxide, lithium carbonate, boric acid, titanium dioxide, calcium carbonate, anhydrous sodium carbonate, silicon dioxide, calcium fluoride and aluminum oxide.

[0052] Examples 1-5

[0053] A preparation method of a high-strength glass-ceramic, the steps are as follows:

[0054] (1) According to the formula shown in Table 1, calculate and weigh the actual amounts of each raw material according to the mass percentages of K2O, MgO, Li2O, B2O3, TiO2, CaO, Na2O, SiO2, CaF2 and Al2O3; after accurate weighing, load the total raw materials: grinding medium: absolute ethanol into the mixing tank according to the mass ratio of 1:2:1 and ball-mill and mix for 8 - 12 h to make it evenly mixed and dry at 60 - 80 °C for 8 - 12 h to obtain a uniformly mixed material;

[0055] (2) Place the mixed material obtained in step (1) in a crucible for melting, heat up to the corresponding melting temperature and hold for the corresponding duration according to Table 1 until the raw materials are melted into a uniform glass liquid;

[0056] (3) Cool and form the glass liquid obtained in step (2), and then anneal the formed glass at the annealing temperature shown in Table 1 for the corresponding duration to obtain transparent glass;

[0057] (4) First hold and nucleate the transparent glass prepared in step (3) at the nucleation temperature shown in Table 1 for the corresponding duration, and then hold and crystallize it at the corresponding crystallization temperature for the corresponding duration to obtain the corresponding high-strength glass-ceramics.

[0058] Table 1 List of formula compositions and process parameters for Examples 1 - 5

[0059]

[0060] Comparative Examples 1 - 5

[0061] Table 2 is a statistical table of the formula compositions and process parameters for Comparative Examples 1 - 5. Prepare the corresponding glass-ceramics for Comparative Examples 1 - 5 according to the raw material ratios and process parameters shown in Table 2.

[0062] Among them, in Comparative Example 1, TiO2 > 5 wt%, and due to the excessive content of the nucleating agent, the crystals are prone to grow rapidly during the crystallization process, resulting in difficult control of the nucleation and crystallization heat treatment, thus affecting the overall crystallization effect.

[0063] In Comparative Example 2, CaO > 10 wt%, which means that the calcium source for forming the crystal phase is in excess, but these excessive calcium sources have not been completely converted into the crystal phase, resulting in insufficient formation of the crystal phase.

[0064] In Comparative Example 3, the content of SiO2 < 40 wt%, resulting in insufficient supply of the silicon source for forming the crystal phase, and as a result, not enough crystal phases can be formed.

[0065] In Comparative Example 4, the content of SiO2 > 60 wt%, resulting in an excessive amount of the silicon source for forming the crystal phase. The excess of the silicon source also cannot be effectively converted into more crystal phases, affecting the formation of the crystal phase and unable to form enough crystal phases.

[0066] In Comparative Example 5, the content of CaF2 > 15 wt%, which results in an excess of fluorine and calcium sources for forming the crystal phase, but these excessive raw materials do not form more crystal phases.

[0067] Table 2 List of formulation compositions and process parameters of Comparative Examples 1 - 5

[0068]

[0069] Comparative Examples 6 - 11

[0070] Table 3 is a statistical table of the formulation compositions and process parameters of Comparative Examples 6 - 11. According to the raw material ratios and process parameters shown in Table 3, the corresponding glass-ceramics of Comparative Examples 6 - 11 were prepared.

[0071] In Comparative Examples 6 - 11, the industrial parameters of the heat treatment of the protective glass were changed.

[0072] Comparative Example 6 shows an inappropriate glass heat treatment process, in which the nucleation temperature < 520 °C. This temperature level is not sufficient to cause the nucleating agent to separate from the glass matrix, and the amount of crystal nuclei formed is insufficient. Even after subsequent crystallization heat treatment, due to the insufficient total amount of crystallization, this glass-ceramic cannot fully utilize the advantages of its high proportion of crystal phases.

[0073] In Comparative Example 7, the nucleation temperature > 630 °C. At this high temperature, the nucleating agent cannot effectively precipitate from the glass matrix, which results in insufficient crystallization during the subsequent crystallization process.

[0074] In Comparative Example 8, the nucleation time < 2 h, and this time length is too short to achieve sufficient crystallization, thus unable to exhibit the performance advantages of the glass-ceramic with a high proportion of crystal phases.

[0075] In Comparative Example 9, the crystallization temperature < 720 °C, and it is actually still in the nucleation heat treatment stage and fails to enter the true crystallization heat treatment stage. Therefore, the overall amount of crystallization is low.

[0076] In Comparative Example 10, the crystallization temperature > 860 °C, which makes the crystallization process difficult to control, the crystal phase grows rapidly, and may make the overall structure of the material unstable.

[0077] In Comparative Example 11, the crystallization time < 1 h, and this time is too short for the crystal phase to grow enough time to form a complete crystal structure.

[0078] Table 3 List of formulation compositions and process parameters of Comparative Examples 6 - 11

[0079]

[0080] The test of the mechanical properties of the glass-ceramics refers to the following standards:

[0081] Test method for compressive strength: Cut the prepared glass-ceramics into blocks with dimensions of 5×5×5 mm, and polish them to make the surface flat, smooth, and free of obvious defects. Use a universal testing machine to test the compressive strength. GB / T 4740-1999 Test method for compressive strength of ceramic materials.

[0082] Test method for flexural strength: Cut the prepared glass-ceramics into blocks with dimensions of 5×5×30 mm, and polish them to make the surface flat, smooth, and free of obvious defects. Use a universal testing machine to test the flexural strength, and the test standard refers to the national standard GB / T 37781-2019 Test method for flexural strength of glass materials.

[0083] The mechanical properties and crystallinity of the high-strength glass-ceramics prepared in Examples 1 to 5 are shown in Table 4.

[0084] Table 4 List of mechanical properties and crystallinity of the products corresponding to the examples

[0085]

[0086] The mechanical properties and crystallinity of the high-strength glass-ceramics prepared in Comparative Examples 1 to 5 are shown in Table 5.

[0087] Table 5 List of mechanical properties and crystallinity of the products corresponding to Comparative Examples 1 to 5

[0088]

[0089] The mechanical properties and crystallinity of the high-strength glass-ceramics prepared in Comparative Examples 6 to 11 are shown in Table 6.

[0090] Table 6 List of mechanical properties and crystallinity of the products corresponding to Comparative Examples 6 to 11

[0091]

[0092] As can be seen from Table 4, the high-strength glass-ceramics material provided by the present invention has good mechanical properties: the compressive strength is greater than 900 Mpa, and the flexural strength is greater than 150 Mpa. The crystallinity reaches more than 75%, indicating good crystallinity.

[0093] It can be seen from Table 5 and Table 6 that outside the glass formula ratio and the heat treatment process parameter range protected by the present invention, the glass formula and process cannot form glass-ceramics with a high crystallinity, resulting in a decrease in its compressive strength and flexural strength, affecting the mechanical properties of the glass-ceramics.

[0094] Figures 1 - 5The following are comparison pictures of the glass prepared in Examples 1 to 5 before and after microcrystallization. Figures 1 - 5 It can be seen that the high-strength microcrystalline glass material provided in the embodiment of the present invention is in a transparent state before microcrystallization and in a white opaque state after microcrystallization.

[0095] Figures 6 - 10 The scanning electron microscope (SEM) images of the glass-ceramics prepared in Examples 1 to 5 show that the glass-ceramics have an obvious crystalline structure inside.

[0096] Figures 11 - 15 The X-ray diffraction diagram (XRD) of the glass-ceramics prepared in Examples 1 to 5 shows that the main crystal phase of the glass-ceramics material is Ca2Si2O7F2, and the secondary crystal phase is Ca2SiO4. Each embodiment has a good crystallization rate, ranging from 76% to 85%. The crystallization rate of the glass-ceramics prepared in Example 3 reaches 85%.

[0097] Figure 16 is a differential scanning calorimetry (DSC) curve of the glass-ceramics prepared in Example 3. Figure 16 It can be seen that the microcrystalline glass has thermal stability and phase change characteristics.

[0098] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A high-strength microcrystalline glass, characterized in that, Prepared from components with the following mass percentages: 5-7 wt% K2O, 6-10 wt% MgO, 2-3 wt% Li2O, 4-5 wt% B2O3, 2-5 wt% TiO2, 5-10 wt% CaO, 5-8 wt% Na2O, 45-55 wt% SiO2, 5-15 wt% CaF2, and 3-5 wt% Al2O3; the main crystal phase of the high-strength glass-ceramics is Ca2Si2O7F2, and the secondary crystal phase is Ca2SiO4.

2. The preparation method of the high-strength glass-ceramics according to claim 1, characterized in that, Including the following steps: (1) Weigh each raw material according to the component ratio. After mixing the raw materials evenly, melt them at 1350-1550 °C to obtain a glass melt. (2) After annealing the glass melt in step (1) at 450-500 °C, a transparent glass is obtained. (3) The transparent glass in step (2) is first kept at 520-630 °C for nucleation for 2-4 h, and then kept at 720-860 °C for crystallization for 1-3 h to obtain the high-strength glass-ceramics.

3. The preparation method of the high-strength glass-ceramics according to claim 2, characterized in that, The method of mixing the raw materials evenly in step (1) is as follows: according to the mass ratio of raw material : grinding medium : absolute ethanol = 1 : 2 : 1, load the raw material, grinding medium, and absolute ethanol into a mixing tank, ball-mill and mix for 8-12 h, and then dry at 60-80 °C for 8-12 h.

4. The preparation method of the high-strength glass-ceramics according to claim 3, characterized in that, The grinding medium is zirconia balls with a diameter of 1-50 mm.

5. The preparation method of the high-strength glass-ceramics according to claim 2, characterized in that, The melting time in step (1) is 1-4 h.

6. The preparation method of the high-strength glass-ceramics according to claim 5, characterized in that, The annealing time in step (2) is 8-12 h.

7. The preparation method of the high-strength glass-ceramics according to claim 2, characterized in that, The transparent glass in step (3) is first kept at 550-600 °C for nucleation for 2-4 h, and then kept at 750-850 °C for crystallization for 1-2 h.

8. Application of the high-strength glass-ceramics according to claim 1 in the fields of electronics and microelectronics, architecture, automotive manufacturing, ocean engineering, and aerospace.

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