Glass ceramic and preparation method thereof, reinforced glass ceramic and preparation method thereof, and glass product

Abstract

The invention relates to the technical field of glass, in particular to microcrystalline glass and a preparation method thereof, reinforced microcrystalline glass and a preparation method thereof, and a glass product. The invention provides microcrystalline glass which comprises the following components in percentage by mass based on the total mass of 100%: 58.21-70.63% of SiO2; the content of Al2O3 is 6.46 to 7.83 percent; zrO2: 3.23% to 3.92%; 1.86%-2.3% of P2O5 (P2O5); 0.4 to 0.5 percent of B2O3; 1.9 to 14.4% of a rare earth metal oxide; an alkali metal oxide: 10.86 to 12.99%; wherein the rare earth metal oxide is prepared from Y2O3 and La2O3; the alkali metal oxide comprises Na2O and Li2O. According to the microcrystalline glass disclosed by the invention, the link of a glass network is enhanced by utilizing the rare earth metal oxide and Al2O3 together to form a high-density network structure, uniform nucleation is induced through the nucleating agent, fine grains are generated, grain boundary defects are reduced according to a multi-step nucleation-crystallization system, and the mechanical property is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of glass, and particularly to a glass-ceramic, a preparation method thereof, a strengthened glass-ceramic, a preparation method thereof, and a glass product. Background Art

[0002] With the rapid development of the intelligent touch-screen electronic product market, the performance requirements for display cover plate materials are increasing day by day, including but not limited to higher drop resistance and better scratch resistance. As a ceramic material prepared by precisely controlling the nucleation and crystallization processes, glass-ceramic has gradually become a preferred material in high-end flagship electronic devices due to its high transparency, excellent chemical stability, and mechanical strength.

[0003] Currently, the main crystal phase components of transparent glass-ceramics on the market are lithium disilicate and spodumene. Compared with traditional lithium aluminosilicate system glasses, significant improvements have been achieved in performance, especially in terms of drop resistance, which has been increased by nearly twice, reaching a height of more than 2 meters (under the condition of a 196-gram load). However, the transparent glass-ceramics in the prior art face the problem of mismatch between the types and proportions of nucleating agents, which easily leads to surface crystallization rather than overall uniform crystallization, resulting in uneven crystallization and segregation. In addition, although the alkali metals introduced to promote the formation of the target crystal phase solve the kinetic problem of crystal phase growth, they also cause the glass network structure to become loose, thus affecting the overall strength. These problems limit the potential of transparent glass-ceramics in wider applications. Summary of the Invention

[0004] The main object of the present invention is to propose a glass-ceramic, a preparation method thereof, a strengthened glass-ceramic, a preparation method thereof, and a glass product, aiming to solve the problems of loose glass network structure and low overall strength of transparent glass-ceramics in the prior art.

[0005] To achieve the above object, an embodiment of the present invention provides a glass-ceramic, calculated based on the total mass of the glass-ceramic being 100%, including the following components in mass percentage:

[0006]

[0007]

[0008] Among them, the rare earth metal oxides include Y2O3 and La2O3; the alkali metal oxides include Na2O and Li2O.

[0009] In some embodiments, the mass percentage contents of Al2O3, Y2O3, La2O3, ZrO2, and P2O5 satisfy 1.56 ≤ ([Al2O3] + [Y2O3] + [La2O3]) / ([ZrO2] + [P2O5]) ≤ 3.9, where [Al2O3] is the mass percentage content of Al2O3, [Y2O3] is the mass percentage content of Y2O3, [La2O3] is the mass percentage content of La2O3, [ZrO2] is the mass percentage content of ZrO2, and [P2O5] is the mass percentage content of P2O5.

[0010] In some embodiments, based on the total mass of the glass-ceramics being 100%, the mass percentage content of Y2O3 is 0 - 7.22%, and the mass percentage content of La2O3 is 0 - 7.18%.

[0011] In some embodiments, based on the total mass of the glass-ceramics being 100%, the mass percentage content of Na2O is 1.21 - 1.49%, and the mass percentage content of Li2O is 9.45 - 11.51%.

[0012] In some embodiments, the glass-ceramics further includes a fining agent. Based on the total mass of the glass-ceramics composition being 100%, the mass percentage content of the fining agent is 0.1 - 0.4%; the fining agent includes at least one of CeO2, SnO2, NaNO3, NH4NO3, Na2SO4, BaSO4, and CaSO4.

[0013] In some embodiments, based on the total mass of the glass-ceramics being 100%, the mass percentage content of CeO2 is 0 - 0.4%; the mass percentage content of SnO2 is 0 - 0.1%.

[0014] On the other hand, an embodiment of the present invention further provides a method for preparing glass-ceramics, including the following steps: preparing each component according to the above-mentioned glass-ceramics to obtain a batch mixture; heating the batch mixture to melt, clarify, shape, and anneal to obtain a glass frit; and subjecting the glass frit to heat treatment for crystallization to obtain the glass-ceramics.

[0015] In some embodiments, the heat treatment crystallization step includes the following four steps: the first nucleation: heating at a heating rate of 10 - 15 °C / min to 520 - 570 °C and holding for 3 - 4 h; the second nucleation: heating at a heating rate of 10 - 15 °C / min to 600 - 640 °C and holding for 3 - 4.5 h; the third crystallization: heating at a heating rate of 10 - 15 °C / min to 680 - 700 °C and holding for 1 - 5 h; the fourth nucleation: cooling at a cooling rate of 0 - 5 °C / min to 560 - 580 °C, holding for 1 - 2 h and then cooling.

[0016] On the other hand, an embodiment of the present invention further provides a strengthened glass-ceramic, which is obtained by ion exchange of the above-mentioned glass-ceramic.

[0017] In some embodiments, the strengthened glass-ceramic includes at least one of the following performance parameters:

[0018] (1) The elastic modulus of the strengthened glass-ceramic is 95 to 121 GPa;

[0019] (2) The fracture toughness of the strengthened glass-ceramic is 1.4 to 1.9 MPa·m 0.5 ;

[0020] (3) The four-point flexural strength of the strengthened glass-ceramic is 660 to 935 MPa;

[0021] (4) The haze of the strengthened glass-ceramic is 0.2% to 0.35%;

[0022] (5) The light transmittance of the strengthened glass-ceramic at a wavelength of 550 nm is 88.5% to 90.5%;

[0023] (6) The surface compressive stress value CS of the strengthened glass-ceramic is 210 to 245 MPa;

[0024] (7) The compressive stress value CS-30 at a depth of 30 μm of the strengthened glass-ceramic is 149 to 170 MPa;

[0025] (8) The ion exchange depth DOL of the compressive stress layer of the strengthened glass-ceramic is 126 to 135 μm;

[0026] (9) The failure height of the drop test of the strengthened glass-ceramic is 160 to 200 cm;

[0027] (10) At a frequency of 2.5 GHz, the dielectric loss of the strengthened glass-ceramic is 0.0025 to 0.0055, and the dielectric constant is 5.35 to 5.6;

[0028] (11) At a frequency of 10 GHz, the dielectric loss of the strengthened glass-ceramic is 0.0035 to 0.0068, and the dielectric constant is 5.52 to 6.14.

[0029] On the other hand, an embodiment of the present invention also provides a method for preparing strengthened glass-ceramics, comprising the following steps: placing the above-mentioned glass-ceramics, or the glass-ceramics prepared by the method for preparing the above-mentioned glass-ceramics, in a mixed molten salt for ion exchange treatment for 4 h to 8 h at a temperature of 440 °C to 460 °C, wherein the mixed molten salt comprises LiNO3, NaNO3 and KNO3, and the mass ratio of LiNO3, NaNO3, KNO3 is LiNO3:NaNO3:KNO3 = 0.02:(35 - 40):(60 - 65).

[0030] On the other hand, an embodiment of the present invention also provides a glass product, comprising the above-mentioned strengthened glass-ceramics, or the strengthened glass-ceramics prepared by the method for preparing the above-mentioned strengthened glass-ceramics.

[0031] Through composition optimization and synergistic effects, the glass-ceramic composition of the technical solution of the present invention successfully solves the problems of uneven crystallization, loose network structure and insufficient strength of existing transparent glass-ceramics. This composition uses rare earth metal oxides (such as Y2O3, La2O3) and Al2O3 to jointly enhance the link of the glass network, forming a highly dense network structure, and induces uniform nucleation through nucleating agents (ZrO2, P2O5) to generate fine grains. According to the multi-step nucleation-crystallization regime, the grain boundary defects are reduced, and the mechanical properties are significantly improved, including an elastic modulus of up to 95 - 121 GPa and a four-point flexural strength of 660 - 935 MPa.

[0032] In addition, the glass-ceramics has the characteristics of uniform crystallization and high transparency, with a transmittance of up to 88.5 - 90.5% @ 550 nm and a haze of only 0.2 - 0.35%. At the same time, excellent drop resistance and high-frequency dielectric properties are achieved. The application of the ion exchange strengthening technology enables the deep compressive stress layer to reach CS 210 - 245 MPa and DOL 126 - 135 μm, greatly enhancing the surface impact resistance. Finally, through the optimized four-step heat treatment process and cost control strategy, not only the process stability is improved, but also the production economy and the possibility of large-scale industrial application are improved. This innovation provides an ideal material solution for high-end displays and communication devices. Detailed Embodiments

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to 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.

[0034] In the present invention, the term "and / or" describes the relationship between related objects and indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, or B exists alone. Here, A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0035] In the present invention, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following items" or a similar expression means any combination of these items, including any combination of a single item or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can each be single or plural.

[0036] It should be understood that in various embodiments of the present invention, the magnitude of the sequence numbers of the above - mentioned processes does not imply the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0037] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The singular forms "a", "the", and "said" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0038] The weight of the relevant components mentioned in the specification of the embodiments of the present invention not only can refer to the specific content of each component, but also can represent the proportional relationship between the weights of each component. Therefore, as long as the content of the relevant components in the specification of the embodiments of the present invention is scaled up or down proportionally, it is within the scope disclosed in the specification of the embodiments of the present invention. Specifically, the mass described in the specification of the embodiments of the present invention can be mass units well - known in the chemical field such as μg, mg, g, kg, etc.

[0039] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on what can be achieved by those of ordinary skill in the art. When the combination of technical solutions results in contradictions or cannot be achieved, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] Currently, the main crystal phases of transparent glass-ceramics are lithium disilicate and spodumene, which have significantly improved performance in terms of anti-drop and other properties compared to traditional lithium aluminosilicate system glasses. However, there are still some challenges in the existing technology: for example, it is difficult to optimize the selection and proportion of nucleating agents, which often leads to crystal growth only on the surface rather than uniform crystallization of the entire material, resulting in problems such as uneven crystal distribution and compositional segregation.

[0041] Based on this, an embodiment of the present invention provides a glass-ceramic, calculated based on the total mass of the glass-ceramic being 100%, comprising components with the following mass percentages:

[0042]

[0043] Among them, rare earth metal oxides include Y2O3 and La2O3; alkali metal oxides include Na2O and Li2O.

[0044] Among them, SiO2 not only acts as a glass network former to construct its basic framework, but also serves as the silicon source for the main crystal phases such as lithium disilicate (Li2Si2O5) and spodumene (LiAlSi4O 10 ). Exemplarily, the mass percentage of SiO2 can be selected as typical but non-limiting values such as 58.2%, 59%, 60%, 62%, 64%, 66%, 68%, 70% or 70.63%. When the mass percentage of SiO2 is too high, it will lead to an increase in the melting temperature, thereby increasing the risk of generating stones, streaks and crystallization. On the contrary, if the mass percentage of SiO2 is too low, it is difficult to endow the material with key properties such as proper chemical stability, mechanical strength and hardness. By controlling the content of SiO2 within the range of 58.21% to 70.63%, not only can the above problems be avoided, but also the final product can have excellent comprehensive properties.

[0045] As an intermediate in the glass network, Al2O3 has two aspects of influence. On the one hand, the formed aluminum-oxygen tetrahedra create larger pores in the network structure compared to silicon-oxygen tetrahedra, which is beneficial for further improving properties such as the chemical stability and mechanical strength of the material through ion exchange subsequently. On the other hand, the addition of Al2O3 will cause a significant increase in the glass viscosity. This not only may lead to uneven streaks and bubbles being difficult to effectively remove during the clarification stage, but also will reduce the crystallization ability of the glass during the subsequent crystallization process. Especially at uneven streaks, crystallization devitrification is likely to occur, thus failing to meet the requirements of high crystallization rate and transparency. In view of the above factors, in the embodiments of the present invention, by controlling the content range of Al2O3 to be between 6.46% and 7.83%, the positive influence of Al2O3 on the glass network structure can be fully utilized to enhance the ion exchange performance and mechanical strength of the material, and a series of problems caused by too high content of Al2O3 can be avoided, such as difficulties in clarification, bubble residue, and crystallization devitrification and other defects. Exemplarily: the mass percentage content of Al2O3 can be typical but non-limiting values such as 6.46%, 6.5%, 6.7%, 7.0%, 7.2%, 7.4%, 7.6%, 7.8%, 7.83%, etc.

[0046] In the embodiments of the present invention, nucleating agents ZrO2 and P2O5 are also introduced, and these two components jointly promote the optimization of the glass system. First of all, P2O5 can achieve controllable nucleation of lithium disilicate crystals, significantly increase the nucleation density, and contribute to the control of the growth rate during the overall crystallization growth process. Due to the P 5+ ions competing with Si 4+ ions for oxygen ions in the glass network, the addition of P2O5 will cause phase separation of the glass, forming two amorphous phases (intermediate phases) rich in lithium orthophosphate and lithium metasilicate. By inducing this phase separation, phosphorus pentoxide promotes heterogeneous nucleation, thus forming an interlocking structure during the crystallization process, and further enhancing the chemical stability of the material. The content of P2O5 is controlled between 1.86% and 2.3%. Exemplarily, it can be typical but non-limiting values such as 1.86%, 1.88%, 1.9%, 1.95%, 2%, 2.1%, 2.2%, 2.3%, etc.

[0047] On the other hand, ZrO2, as one of the most widely used nucleating agents in the microcrystalline system, enhances the degree of linkage of the silicate glass network and the liquid-phase separation effect, and promotes the formation of the lithium metasilicate transition phase. However, with the increase in the content of ZrO2, the glass viscosity will also increase accordingly, which to a certain extent inhibits the formation of crystals. Therefore, in order to balance these effects and obtain the best comprehensive performance, the content of ZrO2 is controlled between 3.23% and 3.92%. Exemplarily, it can be typical but non-limiting values such as 3.23%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.92%, etc.

[0048] B2O3 is also introduced as a glass network former, and its role is dual. On the one hand, B2O3 can reduce the viscosity of the glass at high temperatures and increase the glass viscosity at low temperatures, thereby optimizing the melting process of the glass and improving the intrinsic scratch resistance of the glass at the macroscopic level. On the other hand, B2O3, as a flux, can accelerate the melting and clarification processes of the glass, which helps to improve production efficiency and product quality. However, B2O3 is prone to volatilization at high temperatures and has a strong corrosive effect on refractory materials. In addition, in this glass system, B2O3 mainly exists in the form of borate tetrahedra [BO4], and this structure can significantly reduce the crystallization tendency. But with the increase in the content of boron oxide, the so-called "boron anomaly" phenomenon will occur, that is, the physical properties of the glass such as density, refractive index, etc. change non-linearly, which may affect the overall performance of the glass.

[0049] In view of the above factors, the content of B2O3 is controlled between 0.4% and 0.5%. This range can not only make full use of the advantages of B2O3 in improving the glass melting process, but also avoid the negative impacts brought by its high-temperature volatility and corrosiveness to refractory materials, and at the same time minimize the occurrence of the "boron anomaly" phenomenon, making the glass have excellent stability and mechanical properties. Exemplarily, the content of P2O5 can be typical but non-limiting values such as 0.4%, 0.42%, 0.44%, 0.46%, 0.48%, 0.5%, etc.

[0050] The rare earth metal oxides Y2O3 and La2O3 introduced in the embodiments of the present application can inhibit the nucleation process of lithium metasilicate. These rare earth elements accelerate the transformation process from the intermediate phase lithium metasilicate to lithium disilicate through ion diffusion at high temperatures, and a lower diffusion energy barrier is exhibited in this process. The use of rare earth metal oxides not only promotes the formation of heterogeneous reinforcement phases, makes the grains more uniform and the packing density increase, thus significantly improving the overall performance of the material.

[0051] In this glass system, rare earth metal ions exist as network-forming ions, enhancing the compactness of the glass network structure and increasing the crystallization activation energy. This strengthening effect improves the microstructure of the glass, making it stronger and more stable. Specifically, the addition of rare earth metal oxides not only optimizes the crystal growth environment inside the glass but also enhances the overall properties and stability of the glass by adjusting the network structure.

[0052] By controlling the mass percentage content of rare earth metal oxides within the range of 1.9% to 14.4%, not only the microstructure of the glass-ceramics is regulated, but also its mechanical properties and chemical stability are significantly enhanced. Exemplarily, the content of rare earth metal oxides can be typical but non-limiting values such as 1.9%, 2.5%, 5%, 8%, 12%, 14.4%, etc.

[0053] Alkali metal oxides, including sodium oxide (Na2O) and lithium oxide (Li2O), are also introduced into this glass-ceramic composition as components outside the glass network. The combination of the two can produce a significant double-alkali effect, thereby reducing the viscosity of the glass. In the glass network structure, lithium ions (Li + ) can act as primary exchange ions and first form a preliminary compressive stress (CS) through the ion exchange process. Subsequently, sodium ions (Na + ) and their states after the initial exchange can serve as secondary exchange ions to further enhance the compressive stress value to a higher level.

[0054] In addition, Li + also acts as a lithium source for generating the main crystal phases (such as lithium disilicate and spodumene), providing necessary conditions for subsequent glass crystallization. However, it should be noted that the content of alkali metal ions (Na + , Li + ) should not be too high, because excessive amounts will cause the glass network structure to become loose, weaken the chemical stability of the uncrystallized glass substrate, and easily lead to stress relaxation phenomena, affecting the improvement of the chemical strengthening effect. By controlling the mass percentage content of alkali metal oxides within the range of 10.86% to 12.99%, the properties of the glass reach an optimal level. Exemplarily, the content of alkali metal oxides can be typical but non-limiting values such as 10.86%, 11%, 11.5%, 11.8%, 12%, 12.5%, 12.99%, etc.

[0055] In summary, a microcrystalline glass proposed in the embodiments of the present application significantly improves the existing transparent microcrystalline glass by precisely controlling the mass percentages of various components. This composition utilizes the synergistic effect of rare earth metal oxides and Al2O3 to enhance the linkage of the glass network structure, reduce structural pores, and form a highly dense network structure. At the same time, the nucleating agents ZrO2 and P2O5 induce uniform nucleation, generating fine-grained crystals and reducing grain boundary defects. In addition, rare earth metal oxides inhibit the crystallization of lithium metasilicate and promote the formation of lithium disilicate and spodumene, making the crystal phase distribution more uniform, thereby enhancing the mechanical properties and optical transparency of the material. This technical method solves the problems of uneven crystallization, loose network structure, and insufficient strength existing in traditional microcrystalline glass, improves the comprehensive performance, and meets the application requirements of high-end displays and communication devices.

[0056] In some embodiments, the mass percentage contents of Al2O3, Y2O3, La2O3, ZrO2, and P2O5 satisfy 1.56 ≤ ([Al2O3] + [Y2O3] + [La2O3]) / ([ZrO2] + [P2O5]) ≤ 3.9, where [Al2O3] is the mass percentage content of Al2O3, [Y2O3] is the mass percentage content of Y2O3, [La2O3] is the mass percentage content of La2O3, [ZrO2] is the mass percentage content of ZrO2, and [P2O5] is the mass percentage content of P2O5. Exemplarily, ([Al2O3] + [Y2O3] + [La2O3]) / ([ZrO2] + [P2O5]) can be typical but non-limiting values such as 1.56, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.3, 3.6, 3.9, etc.

[0057] When the mass percentage ratio of network formers / intermediates (Al2O3, Y2O3, La2O3) to nucleating agents (ZrO2 and P2O5) in the glass composition is controlled within 1.56 - 3.9, the performance of the microcrystalline glass is further improved through their synergistic effect. Specifically, the nucleating agents (ZrO2 and P2O5) provide a large number of heterogeneous nucleation sites, promoting uniform crystallization of grains and avoiding the strength reduction and optical scattering caused by grain coarsening in traditional processes. While the network formers (Al2O3) and rare earth metal oxides (Y2O3, La2O3) enhance the linkage of the glass network structure, reduce free oxygen, and inhibit abnormal grain growth. At the same time, rare earth ions preferentially occupy the nucleation sites of low-strength crystal phases (such as lithium metasilicate), promoting their transformation into high-strength lithium disilicate and spodumene, and improving the grain packing density through the filling effect, thus enhancing the flexural strength. In addition, the dense network structure also delays the Li + / Na +The diffusion rate forms a deeper compressive stress layer, enhancing the anti-drop performance. This proportion design resolves the contradiction in traditional microcrystalline glass where grain refinement is incompatible with high strength and high light transmittance by balancing the nucleation density and grain growth rate, achieving the synergistic optimization of nanoscale uniform crystallization, suppression of harmful crystal phases, and strengthening of the glass network.

[0058] In some embodiments, based on the total mass of the microcrystalline glass being 100%, the mass percentage content of Y2O3 is 0 - 7.22%, and the mass percentage content of La2O3 is 0 - 7.18%; exemplarily, the content of Y2O3 can be typical but non-limiting values such as 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7.22%, etc.; exemplarily, the content of La2O3 can be typical but non-limiting values such as 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7.18%, etc.

[0059] By controlling the content of Y2O3 and La2O3 within the ranges of 0% - 7.22% and 0% - 7.18%, this technical solution not only retains the core role of rare earth metal oxides in densifying the glass network and orienting the growth of crystal phases but also further improves the performance of the microcrystalline glass material.

[0060] In some embodiments, based on the total mass of the microcrystalline glass being 100%, the mass percentage content of Na2O is 1.21 - 1.49%, and the mass percentage content of Li2O is 9.45 - 11.51%; exemplarily, the content of Na2O can be typical but non-limiting values such as 1.21%, 1.3%, 1.35%, 1.4%, 1.45%, 1.49%, etc.; exemplarily, the content of Li2O can be typical but non-limiting values such as 9.5%, 10%, 10.5%, 11%, 11.5%, etc.

[0061] By regulating the mass percentage content of Na2O and Li2O within the above ranges, this technical solution further optimizes the ion exchange depth and thermal processing performance while maintaining high strength and high light transmittance.

[0062] In some embodiments, the microcrystalline glass further includes a clarifying agent. Based on the total mass of the microcrystalline glass composition being 100%, the mass percentage content of the clarifying agent is 0.1 - 0.4%; the clarifying agent includes at least one of CeO2, SnO2, NaNO3, NH4NO3, Na2SO4, BaSO4, and CaSO4.

[0063] By adding 0.1 - 0.4% of clarifying agents (such as CeO2, SnO2, nitrates, sulfates, etc.), the purity and micro - homogeneity of the glass - ceramic melt are significantly improved. For example, CeO2 and SnO2 can form an oxidation - reduction pair during the melting stage, decompose and promote the escape of bubbles; the high - temperature decomposition of Na2SO4 and BaSO4 can release SO3 gas, generating a gas expansion effect; and the decomposition of NH4NO3 and NaNO3 can produce nitrogen and water vapor, thereby removing bubbles and impurities in the melt, reducing the porosity and the residual sulfur content in the melt. These improvements greatly enhance the optical properties of the glass, increase the light transmittance, reduce the haze, and significantly optimize the overall quality and application effect of the transparent glass - ceramic.

[0064] In some embodiments, based on the total mass of the glass - ceramic being 100%, the mass percentage content of CeO2 is 0 - 0.4%; the mass percentage content of SnO2 is 0 - 0.1%.

[0065] Ce 4+ can, during the high - temperature melting stage (1400 - 1600 °C), through an oxidation reaction (such as oxidizing Fe 2+ to Fe 3+ , promoting the decomposition of CO3 2- into CO2), thereby removing reducing gases (such as CO, SO2) in the melt and reducing the residual bubbles. SnO2 can, during the 900 - 1200 °C stage, release O2 through the valence change of Sn 2+ / Sn 4+ , promoting the merger and floating of tiny bubbles, especially having a significant effect on the oxidative removal of sulfides (such as FeS). Both of these clarifying agents have the advantages of low residue and strong stability.

[0066] On the other hand, the embodiments of the present invention also provide a method for preparing a glass - ceramic, comprising the following steps: preparing each component of the glass - ceramic as described above, mixing to obtain a batch; heating the batch to melt, clarify, shape, and anneal to obtain a glass frit; and subjecting the glass frit to heat treatment for crystallization to obtain the glass - ceramic.

[0067] The glass - ceramic of the embodiments of the present invention can be manufactured by known and conventional glass - making processes in the art. Among them, the batch can be ground and sieved, which helps to improve the uniform mixing between various components during the subsequent melting process. For example, it can be sieved through a 80 - mesh sieve 3 to 5 times. "Melting" means heating the raw materials of the glass composition after mixing to a high temperature to make them completely melt. "Clarifying" means removing bubbles and other impurities. "Shaping" means shaping the molten glass into the desired shape. "Annealing" means reducing internal stress by controlling the cooling rate to improve the mechanical strength and stability of the glass.

[0068] In some embodiments, the forming method can be selected from the float process, the slot-draw process, or the overflow process. Among them, the float process means that molten glass is poured onto a layer of molten metal (usually tin) using the float process, and it naturally spreads to form a flat surface. The slot-draw process means that molten glass is uniformly drawn and formed through a slot die, which is suitable for producing thin sheet glass. The overflow process means that an overflow trough is used to make the molten glass flow out from both sides and converge at the bottom to form a high-quality surface that does not require further polishing.

[0069] In some embodiments, the heat treatment crystallization step includes the following four steps:

[0070] The first nucleation step: Heat from room temperature to 520 - 570 °C at a heating rate of 10 - 15 °C / min and hold for 3 - 4 h;

[0071] The second nucleation step: Based on the temperature of the first nucleation step, heat to 600 - 640 °C at a heating rate of 10 - 15 °C / min and hold for 3 - 4.5 h;

[0072] The third crystallization step: Based on the temperature of the second nucleation step, heat to 680 - 700 °C at a heating rate of 10 - 15 °C / min and hold for 1 - 5 h;

[0073] The fourth nucleation step: Based on the temperature of the third crystallization step, cool down to 560 - 580 °C at a cooling rate of 0 - 5 °C / min, hold for 1 - 2 h and then cool.

[0074] The preparation of existing transparent glass-ceramics faces the problem of complex crystallization processes. Due to its strong crystallization tendency, it is prone to excessive crystallization size, resulting in devitrification and non-uniformity. This preparation method further realizes a more highly dense glass network structure and further eliminates local stress through a four-step heat treatment process. This method reduces the existence of microcracks at grain boundaries and uses microcrystals to hinder crack propagation, thus significantly improving the drop resistance of the material.

[0075] Specifically: During the third crystallization step, spodumene, lithium disilicate, lithium metasilicate, and β-quartz solid solution are formed, achieving a crystallinity of 42% to 69%. Specifically, the crystal components generated in this process include: lithium disilicate accounting for 5.6% to 23.3%, spodumene accounting for 18.9% to 42.1%, lithium metasilicate accounting for 0% to 4.6%, and quartz solid solution accounting for 3.3% to 25.5%. Such a composition indicates that an ideal crystal ratio can be obtained by controlling the crystallization temperature, thereby optimizing the material properties. This step plays an important role in the strength, thermal stability, and chemical stability of the final product.

[0076] The fourth nucleation process helps to trigger new nucleation sites in the glass matrix and slow down the crystal form transformation rate of the quartz solid solution. This not only further improves the glass network structure, increases the density of the material, but also eliminates the local stress caused by the difference in thermal expansion coefficient between the lithium disilicate crystal and the residual glass phase during the cooling process and the crystal form transformation of the quartz solid solution. This process avoids the generation of grain boundary microcracks and plays a key role in further constructing the strengthened glass network structure.

[0077] The crystallization process in this embodiment exhibits excellent stability and reliability. By adopting the above four-step crystallization regime, the diffusion of microcracks can be better prevented, and the thermal stress can be reduced, thereby obtaining products with higher strength, toughness, excellent thermal stability and chemical erosion resistance.

[0078] In some embodiments, the heat treatment crystallization step further includes the following three steps: The first nucleation: heating from room temperature to 520 - 570 °C at a heating rate of 10 - 15 °C / min and holding for 3 - 4 h; The second nucleation: based on the temperature of the first nucleation, heating to 600 - 640 °C at a heating rate of 10 - 15 °C / min and holding for 3 - 4.5 h; The third crystallization: based on the temperature of the second nucleation, heating to 680 - 700 °C at a heating rate of 10 - 15 °C / min and holding for 1 - 5 h. By adopting the above three-step process, a highly dense glass network structure can also be achieved.

[0079] In some embodiments, the steps of heating the batch materials to melt, clarify, form, and anneal to obtain glass frit are as follows: heating the batch materials to 1500 - 1550 °C at a heating rate of 8 - 12 °C / min and holding for clarification for 2 - 3 h, then forming at a temperature of 350 - 450 °C, and then annealing at a temperature of 500 - 550 °C for 1 - 2 h.

[0080] On the other hand, the embodiments of the present application also provide a strengthened glass-ceramic, which is obtained by ion exchange of the above-mentioned glass-ceramic.

[0081] In some embodiments, the elastic modulus of the strengthened glass-ceramic is 95 - 121 GPa.

[0082] In some embodiments, the fracture toughness of the strengthened glass-ceramic is 1.4 - 1.9 MPa·m 0.5 .

[0083] In some embodiments, the four-point flexural strength of the strengthened glass-ceramic is 660 - 935 MPa.

[0084] In some embodiments, the haze of the strengthened glass-ceramic is 0.2% - 0.35%.

[0085] In some embodiments, the light transmittance of the strengthened glass-ceramics at a wavelength of 550 nm is 88.5% to 90.5%.

[0086] In some embodiments, the surface compressive stress value CS of the strengthened glass-ceramics is 210 to 245 MPa.

[0087] In some embodiments, the compressive stress value CS-30 at a depth of 30 μm of the strengthened glass-ceramics is 149 to 170 MPa.

[0088] In some embodiments, the ion exchange depth DOL of the compressive stress layer of the strengthened glass-ceramics is 126 to 135 μm.

[0089] In some embodiments, the failure height of the drop test of the strengthened glass-ceramics is 160 to 200 cm.

[0090] In some embodiments, at a frequency of 2.5 GHz, the dielectric loss of the strengthened glass-ceramics is 0.0025 to 0.0055, and the dielectric constant is 5.35 to 5.6; it should be noted that the dielectric loss of the unstrengthened glass-ceramics is 0.0031 to 0.0055.

[0091] In some embodiments, at a frequency of 10 GHz, the dielectric loss of the strengthened glass-ceramics is 0.0035 to 0.0068, and the dielectric constant is 5.52 to 6.14; it should be noted that the dielectric loss of the unstrengthened glass-ceramics is 0.004 to 0.0068.

[0092] On the other hand, an embodiment of the present invention further provides a method for preparing strengthened glass-ceramics, including the following steps: placing the above-mentioned glass-ceramics, or the glass-ceramics prepared by the above-mentioned method for preparing glass-ceramics, in a mixed molten salt for ion exchange treatment for 4 h to 8 h at a temperature of 440°C to 460°C. The mixed molten salt includes LiNO3, NaNO3, and KNO3, wherein the mass ratio of LiNO3:NaNO3:KNO3 is LiNO3:NaNO3:KNO3 = 0.02:(35 to 40):(60 to 65). As an example: the mass ratio of the three can be: 0.02:35:65, 0.02:36:64, 0.02:37:63, 0.02:38:62, 0.02:39:61, 0.02:40:60 and other typical but non-limiting values.

[0093] On the other hand, an embodiment of the present invention further provides a glass product, including the above-mentioned strengthened glass-ceramics, or the strengthened glass-ceramics obtained by the preparation method of the above-mentioned strengthened glass-ceramics. Due to the adoption of the above-mentioned strengthened glass-ceramics, it has higher strength, toughness, thermal stability, and chemical erosion resistance. The glass product can be a cover glass, backplane glass, or protective film of an electronic device, such as the cover glass, backplane glass, or protective film of a mobile phone. The specific application of the glass product is not limited herein.

[0094] The present invention will be described in detail below through examples and comparative examples. In the following examples and comparative examples, unless otherwise specified, all materials used can be obtained through commercial purchase, and unless otherwise specified, the methods used are conventional methods in the art.

[0095] Example 1

[0096] This example provides a glass-ceramics, its preparation method, a strengthened glass-ceramics, and its preparation method.

[0097] A glass-ceramics, calculated based on the total mass of the glass-ceramics being 100%, includes the following components in mass percentage: SiO2: 61.86%; Al2O3: 6.6%; Na2O: 1.3%; Li2O: 10%; ZrO2: 3.23%; P2O5: 2%; B2O3: 0.41%; Y2O3: 7.3%; La2O3: 7.1%; CeO2: 0.2%.

[0098] A preparation method of a glass-ceramics includes the following steps:

[0099] (1) Weigh each raw material according to the components of the glass-ceramics composition. Mix the raw materials of the glass-ceramics composition evenly to obtain a batch;

[0100] (2) Heat the batch at a heating rate of 10 °C / min to 1500 °C and keep it for clarification for 2 h, then place it in a 400 °C iron mold for forming, and place it in a muffle furnace for annealing at 500 °C for 2 h to obtain a glass frit.

[0101] (3) Obtain a glass-ceramics substrate after heat-treating and crystallizing the glass frit; the heat-treating and crystallizing step includes the following four steps:

[0102] The first nucleation: Heat from room temperature to 550 °C at a heating rate of 10 °C / min and keep it for 4 h;

[0103] The second nucleation: Based on the temperature of the first nucleation, heat to 640 °C at a heating rate of 10 °C / min and keep it for 3 h;

[0104] The third crystallization: Based on the nucleation temperature in the second step, raise the temperature to 700 °C at a heating rate of 10 °C / min and hold for 1 h;

[0105] The fourth nucleation: Based on the crystallization temperature in the third step, lower the temperature to 573 °C at a cooling rate of 5 °C / min, hold for 1 h and then cool down.

[0106] In the heat treatment process, spodumene (LiAlSi4O 10 ), lithium disilicate (Li2Si2O5), lithium metasilicate (Li2SiO3) and β-quartz solid solution (β-SiO2) are formed in the glass-ceramic substrate.

[0107] A preparation method of strengthened glass-ceramics includes: placing the above-mentioned glass-ceramic substrate in a mixed molten salt for ion exchange to obtain the strengthened glass-ceramics. In the ion exchange process, the mass ratio of LiNO3, NaNO3 and KNO3 in the mixed molten salt is LiNO3:NaNO3:KNO3 = 0.02:35:65, the ion exchange time is 7 h, and the ion exchange temperature is 460 °C.

[0108] Example 2-1

[0109] The difference between Example 2-1 and Example 1 is that: for a glass-ceramic, calculated based on the total mass of the glass-ceramic being 100%, it includes the following components in mass percentage: SiO2: 66.7%; Al2O3: 7.4%; Na2O: 1.4%; Li2O: 10.8%; ZrO2: 3.7%; P2O5: 2.2%; B2O3: 0.46%; Y2O3: 3.6%; La2O3: 3.64%; SnO2: 0.1%.

[0110] Example 2-2

[0111] The difference between Example 2-2 and Example 2-1 is that: the heat treatment crystallization step includes the following four steps:

[0112] The first nucleation: Raise the temperature from room temperature to 570 °C at a heating rate of 10 °C / min and hold for 4 h;

[0113] The second nucleation: Based on the nucleation temperature in the first step, raise the temperature to 630 °C at a heating rate of 10 °C / min and hold for 3 h;

[0114] The third crystallization: Based on the nucleation temperature in the second step, raise the temperature to 700 °C at a heating rate of 10 °C / min and hold for 2 h;

[0115] The fourth nucleation: Based on the crystallization temperature in the third step, lower the temperature to 573 °C at a cooling rate of 5 °C / min, hold for 1 h and then cool down.

[0116] Example 2-3

[0117] The difference between Example 2-3 and Example 2-1 is that the heat treatment crystallization step includes the following four steps:

[0118] The first nucleation step: heating from room temperature to 570 °C at a heating rate of 10 °C / min and holding for 4 h;

[0119] The second nucleation step: on the basis of the temperature of the first nucleation step, heating to 640 °C at a heating rate of 10 °C / min and holding for 3 h;

[0120] The third crystallization step: on the basis of the temperature of the second nucleation step, heating to 700 °C at a heating rate of 10 °C / min and holding for 4 h;

[0121] The fourth nucleation step: on the basis of the temperature of the third crystallization step, cooling to 573 °C at a cooling rate of 5 °C / min, holding for 2 h and then cooling.

[0122] Example 2-4

[0123] The difference between Example 2-4 and Example 2-1 is that the heat treatment crystallization step includes the following three steps:

[0124] The first nucleation step: heating from room temperature to 550 °C at a heating rate of 10 °C / min and holding for 4 h;

[0125] The second nucleation step: on the basis of the temperature of the first nucleation step, heating to 640 °C at a heating rate of 10 °C / min and holding for 3 h;

[0126] The third crystallization step: on the basis of the temperature of the second nucleation step, heating to 700 °C at a heating rate of 10 °C / min and holding for 1 h;

[0127] Example 3-1

[0128] The difference between Example 3-1 and Example 1 is that for a microcrystalline glass, calculated based on the total mass of the microcrystalline glass being 100%, it includes the following components in mass percentage: SiO2: 70.6%; Al2O3: 7.8%; Na2O: 1.42%; Li2O: 11.5%; ZrO2: 3.9%; P2O5: 2.3%; B2O3: 0.5%; Y2O3: 0.8%; La2O3: 1%; CeO2: 0.2%.

[0129] Its heat treatment crystallization step includes the following four steps:

[0130] The first nucleation step: heating from room temperature to 540 °C at a heating rate of 10 °C / min and holding for 4 h;

[0131] Second nucleation: Based on the temperature of the first nucleation, increase the temperature at a rate of 10 °C / min to 640 °C and hold for 3 h;

[0132] Third crystallization: Based on the temperature of the second nucleation, increase the temperature at a rate of 10 °C / min to 680 °C and hold for 4 h;

[0133] Fourth nucleation: Based on the temperature of the third crystallization, decrease the temperature at a rate of 5 °C / min to 573 °C, hold for 1 h and then cool down.

[0134] Example 3-2

[0135] The difference between Example 3-2 and Example 3-1 is that its heat treatment crystallization step includes the following four steps:

[0136] First nucleation: Increase the temperature from room temperature at a rate of 10 °C / min to 540 °C and hold for 4 h;

[0137] Second nucleation: Based on the temperature of the first nucleation, increase the temperature at a rate of 10 °C / min to 640 °C and hold for 3 h;

[0138] Third crystallization: Based on the temperature of the second nucleation, increase the temperature at a rate of 10 °C / min to 680 °C and hold for 5 h;

[0139] Fourth nucleation: Based on the temperature of the third crystallization, decrease the temperature at a rate of 5 °C / min to 573 °C, hold for 1 h and then cool down.

[0140] Example 3-3

[0141] The difference between Example 3-3 and Example 3-1 is that its heat treatment crystallization step includes the following four steps:

[0142] First nucleation: Increase the temperature from room temperature at a rate of 10 °C / min to 540 °C and hold for 4 h;

[0143] Second nucleation: Based on the temperature of the first nucleation, increase the temperature at a rate of 10 °C / min to 640 °C and hold for 3 h;

[0144] Third crystallization: Based on the temperature of the second nucleation, increase the temperature at a rate of 10 °C / min to 680 °C and hold for 4.5 h;

[0145] Fourth nucleation: Based on the temperature of the third crystallization, decrease the temperature at a rate of 5 °C / min to 573 °C, hold for 1 h and then cool down.

[0146] Example 3-4

[0147] Example 3-4 is different from Example 3-1 in that its heat treatment crystallization step includes the following three steps:

[0148] The first nucleation: Heating from room temperature to 540 °C at a heating rate of 10 °C / min and holding for 4 h;

[0149] The second nucleation: On the basis of the first nucleation temperature, heating to 640 °C at a heating rate of 10 °C / min and holding for 3 h;

[0150] The third crystallization: On the basis of the second nucleation temperature, heating to 680 °C at a heating rate of 10 °C / min and holding for 5 h;

[0151] Example 4

[0152] Example 4 is different from Example 1 in that a glass-ceramic, based on the total mass of the glass-ceramic being 100%, comprises components with the following mass percentages: SiO2: 64.2%; Al2O3: 7.1%; Na2O: 1.3%; Li2O: 10.42%; ZrO2: 3.4%; P2O5: 2.1%; B2O3: 0.42%; Y2O3: 4.6%; La2O3: 6.2%; CeO2: 0.2%; SnO2: 0.1%.

[0153] Example 5

[0154] Example 5 is different from Example 1 in that a glass-ceramic, based on the total mass of the glass-ceramic being 100%, comprises components with the following mass percentages: SiO2: 69.2%; Al2O3: 7.5%; Na2O: 1.45%; Li2O: 11.2%; ZrO2: 3.8%; P2O5: 1.9%; B2O3: 0.48%; Y2O3: 3%; La2O3: 1.27%; CeO2: 0.1%; SnO2: 0.1%.

[0155] Example 6

[0156] Example 6 is different from Example 1 in that a glass-ceramic, based on the total mass of the glass-ceramic being 100%, comprises components with the following mass percentages: SiO2: 67.9%; Al2O3: 7.5%; Na2O: 1.4%; Li2O: 11%; ZrO2: 3.75%; P2O5: 2.15%; B2O3: 0.47%; Y2O3: 4.5%; La2O3: 1.23%; SnO2: 0.1%.

[0157] Example 7

[0158] Example 7 is different from Example 1 in that: a glass-ceramic, calculated based on the total mass of the glass-ceramic being 100%, comprises components with the following mass percentages: SiO2: 65.41%; Al2O3: 7.3%; Na2O: 1.36%; Li2O: 9.4%; ZrO2: 3.6%; P2O5: 2.1%; B2O3: 0.42%; Y2O3: 5.2%; La2O3: 5.11%; SnO2: 0.1%.

[0159] Comparative Example 1

[0160] Comparative Example 1 is different from Example 5 in that: a glass-ceramic, calculated based on the total mass of the glass-ceramic being 100%, comprises components with the following mass percentages: SiO2: 71.81%; Al2O3: 8.1%; Na2O: 1.51%; Li2O: 12.1%; ZrO2: 3.75%; P2O5: 2.2%; B2O3: 0.42%; SnO2: 0.1%.

[0161] Performance Test

[0162] In order to verify the progressiveness of the embodiments of the present application, the following tests were respectively carried out on the samples of the embodiments and comparative examples:

[0163] 1. Test of crystal phase:

[0164] The surface of the example was tested by an X-ray diffractometer (XRD, Bruker D8 Advance, Germany), and the intensity and peak area of the characteristic peaks were analyzed by Jade software and compared with the standard PDF card to evaluate the crystal phase and crystallinity (mass percentage) of the sample.

[0165] 2. Test of average particle size:

[0166] After the cross-sections of each example were corroded with 10% HF acid for 30 s, ultrasonically cleaned, dried, and surface-sprayed with gold, the cross-sectional micro-morphology (50,000, 100,000, 150,000 times) was observed under a scanning electron microscope (SEM, Zeiss Sigma 300, Germany), and then the grain size was statistically analyzed by NanoMeasurer software.

[0167] 3. Tests of CS and DOL:

[0168] The glass-ceramic cover plates after ion exchange were respectively tested by an FSM-600LEUV and an SLP-2000 surface stress meter (Shihara, Japan). Among them, CS refers to the compressive stress value on the surface of the strengthened glass, CS-30 refers to the compressive stress value at a depth of 30 μm from the surface of the strengthened glass sample, and DOL refers to the ion exchange depth of the compressive stress layer of the strengthened glass.

[0169] 4. Whole machine drop performance test:

[0170] Based on the mobile phone controlled drop test machine (LT-SKDL-CD1800), test 180-mesh sandpaper with a total weight of 196 g respectively. With a base height of 60 cm and increasing the height by 10 cm until it drops and breaks, record it as the final drop performance.

[0171] 5. Haze test:

[0172] Test the haze of the glass based on the transmission haze meter i (BYK Chemie GmbH, Germany).

[0173] 6. Transmittance test:

[0174] Use an ultraviolet-visible spectrophotometer (Shimadzu UV2600i with an integrating sphere, Japan) to test the transmittance in the range of 220 - 1400 nm, and select the transmittance at 550 nm for characterization.

[0175] 7. Elastic modulus test:

[0176] Obtain the elastic modulus based on the dynamic elastic properties tester for solid materials (DST-V).

[0177] 8. Fracture toughness test:

[0178] According to the test method of national standard GB / T 37900-2019, calculate the fracture toughness through a Vickers hardness tester (Matsuzawa VMT-X7S, Japan).

[0179] 9. Four-point flexural test:

[0180] Test the four-point flexural strength based on a universal testing machine (PT307A). The size of the glass-ceramics is 150×70×0.6 mm. After chemical strengthening and then edge grinding and polishing, test the four-point flexure.

[0181] Table 1 and Table 2 are the component tables of the glass-ceramics of each example and comparative example.

[0182] Table 1

[0183]

[0184] Table 2

[0185]

[0186] Table 3 shows the heat treatment process of the glass-ceramics composition of the examples, the properties of the glass-ceramics composition, and the properties of the glass-ceramics cover plate.

[0187] Table 3

[0188]

[0189] Note: In the table, "S1: 550°C / 4h" refers to the first step: heat preservation at 550°C for 4h, and so on for the heat treatment process;

[0190] Table 4 shows the heat treatment processes, properties of the glass-ceramics, and properties of the glass-ceramic covers of the examples and comparative examples.

[0191] Table 4

[0192]

[0193]

[0194] Note: In the table, "S1: 550°C / 4h" refers to the first step: heat preservation at 550°C for 4h, and so on for the heat treatment process;

[0195] From the performance test results of the glasses of the examples and the comparative examples shown in Table 3 and Table 4, it can be seen that the strengthened glass-ceramics adopting the technical solution of the present invention exhibit a series of excellent physical and electrical properties: the elastic modulus is between 95 and 121 GPa, indicating its good rigidity and structural stability; the fracture toughness is in the range of 1.4 to 1.9 MPa·m 0.5 range, showing the good ability of the material to prevent crack propagation; the four-point flexural strength reaches between 660 and 935 MPa, further proving its excellent mechanical strength; the haze is maintained between 0.2% and 0.35%, meaning that this material performs excellently in terms of visual clarity; the transmittance is 88.5% to 90.5% at a wavelength of 550 nm, demonstrating its efficient light transmission performance as a transparent material; the surface compressive stress (CS value) ranges between 210 and 245 MPa, which helps to improve the impact resistance of the material; the CS-30 value is in the range of 149 to 170 MPa, reflecting the stress distribution inside the material; the depth of the compressive stress layer (DOL value) reaches 126 to 135 μm, enhancing the wear resistance of the surface; the safety drop height in the drop height test shows 160 to 200 cm; the dielectric loss is 0.0025 to 0.0055 at a frequency of 2.5 GHz and 0.0035 to 0.0068 at a frequency of 10 GHz, indicating its low energy loss in high-frequency applications; the dielectric constant: it is between 5.35 and 5.6 at 2.5 GHz, and is 5.52 to 6.14 at 10 GHz, which shows its stable electrical performance at different frequencies.

[0196] The above description is only an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention by using the content of the specification of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A glass-ceramic, characterized in that: Taking the total mass of the microcrystalline glass as 100%, the microcrystalline glass comprises the following components in percentage by mass: Wherein, the rare earth metal oxides include Y2O3 and La2O3; the alkali metal oxides include Na2O and Li2O.

2. The glass-ceramic according to claim 1, characterized in that: The mass percentages of Al2O3, Y2O3, La2O3, ZrO2 and P2O5 satisfy 1.56≤([Al2O3]+[Y2O3]+[La2O3]) / ([ZrO2]+[P2O5])≤3.9, wherein [Al2O3] is the mass percentage of Al2O3, [Y2O3] is the mass percentage of Y2O3, [La2O3] is the mass percentage of La2O3, [ZrO2] is the mass percentage of ZrO2, and [P2O5] is the mass percentage of P2O5.

3. The glass-ceramic according to claim 2, characterized in that: Taking the total mass of the microcrystalline glass as 100%, the mass percentage of Y2O3 is 0-7.22%, and the mass percentage of La2O3 is 0-7.18%.

4. The glass-ceramic according to claim 3, characterized in that: Taking the total mass of the microcrystalline glass as 100%, the mass percentage of Na2O is 1.21-1.49%, and the mass percentage of Li2O is 9.45-11.51%.

5. The glass-ceramic according to any one of claims 1 to 4, characterized in that: The microcrystalline glass also includes a clarifier, and the mass percentage of the clarifier is 0.1-0.4% based on the total mass of the microcrystalline glass as 100%; the clarifier includes at least one of CeO2, SnO2, NaNO3, NH4NO3, Na2SO4, BaSO4 and CaSO4.

6. The glass-ceramic according to claim 5, characterized in that: Taking the total mass of the microcrystalline glass as 100%, the mass percentage of CeO2 is 0-0.4%; the mass percentage of SnO2 is 0-0.1%.

7. A method for preparing glass-ceramics, characterized in that: The following steps are involved: Prepare the components of the glass-ceramics according to any one of claims 1 to 6, and mix them to obtain a batch; The batch material is heated to melt, clarified, formed, and annealed to obtain a glass frit; The glass-ceramics are obtained by crystallizing the glass frit through heat treatment.

8. The method for preparing glass-ceramics according to claim 7, characterized in that: The heat treatment crystallization step includes the following four steps: The first step is nucleation: heating to 520-570°C at a heating rate of 10-15°C / min and keeping warm for 3-4h; The second step is nucleation: heating to 600-640°C at a heating rate of 10-15°C / min and keeping warm for 3-4.5h; The third step is crystallization: heating to 680-700°C at a heating rate of 10-15°C / min and keeping warm for 1-5h; The fourth step is nucleation: cool down to 560-580°C at a cooling rate of 0-5°C / min, keep warm for 1-2 hours and then cool.

9. A strengthened glass-ceramic, characterized in that: The strengthened microcrystalline glass is obtained by ion exchange of the microcrystalline glass described in any one of claims 1 to 6 or the microcrystalline glass obtained by the preparation method described in claim 7 or 8.

10. The tempered glass-ceramics according to claim 9, wherein: The strengthened glass-ceramics includes at least one of the following performance parameters: (1) The elastic modulus of the strengthened glass-ceramics is 95 to 121 GPa; (2) The fracture toughness of the strengthened glass-ceramics is 1.4 to 1.9 MPa·m 0.5 ; (3) The four-point flexural strength of the strengthened glass-ceramics is 660-935 MPa-; (4) The haze of the strengthened glass-ceramics is 0.2% to 0.35%; (5) The light transmittance of the strengthened microcrystalline glass at a wavelength of 550 nm is 88.5% to 90.5%; (6) The surface compressive stress value CS of the strengthened glass-ceramics is 210 to 245 MPa; (7) The compressive stress value CS-30 of the strengthened glass-ceramics at a depth of 30 μm is 149 to 170 MPa; (8) The ion exchange depth DOL of the compressive stress layer of the strengthened glass-ceramics is 126 to 135 μm; (9) The failure height of the drop test of the tempered glass-ceramics is 160 to 200 cm; (10) At a frequency of 2.5 GHz, the dielectric loss of the strengthened microcrystalline glass is 0.0025 to 0.0055, and the dielectric constant is 5.35 to 5.6; (11) At a frequency of 10 GHz, the dielectric loss of the strengthened microcrystalline glass is 0.0035 to 0.0068, and the dielectric constant is 5.52 to 6.

14.

11. A method for preparing strengthened glass-ceramics, characterized in that: The method comprises the following steps: placing the glass-ceramics according to any one of claims 1 to 6, or the glass-ceramics prepared by the preparation method according to claim 7 or 8, in a mixed molten salt for ion exchange treatment for 4 h to 8 h at a temperature of 440°C to 460°C, wherein the mixed molten salt comprises LiNO3, NaNO3, and KNO3, wherein the mass ratio of LiNO3, NaNO3, and KNO3 is LiNO3:NaNO3:KNO3=0.02:(35-40):(60-65).

12. A glass product, characterized in that: Including the strengthened microcrystalline glass according to claim 9 or 10, or the strengthened microcrystalline glass prepared by the preparation method according to claim 11.

Images