Glass ceramic and preparation method thereof

Abstract

The invention discloses microcrystalline glass and a preparation method thereof, and relates to the technical field of microcrystalline glass materials, and the microcrystalline glass comprises the following components by mass: 67.3 wt% to 70.8 wt% of SiO2, 2 wt% to 4 wt% of Al2O3, 2.5 wt% to 4 wt% of P2O5, 10 wt% to 13 wt% of Li2O, 2.2 wt% to 5 wt% of Na2O, 1.2 wt% to 3 wt% of K2O, and 6 wt% to 9 wt% of ZrO2. By adjusting the components and the mass percentage of the glass ceramic, the problems of lower surface compressive stress and poorer scratch resistance of the glass ceramic are solved. The microcrystalline glass takes a lithium disilicate crystal phase as a main crystal phase, so that the hardness, the compressive stress, the anti-falling height performance, the optical performance and the crystallinity are improved, and the particle size is reduced.

Description

Technical Field

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

[0002] Glass-ceramics is a composite material composed of an amorphous glass matrix and uniformly distributed crystal phases. It combines the advantages of glass and ceramics and has excellent physical, chemical, and mechanical properties.

[0003] The crystal phases in the glass-ceramics can cause the bending and blunting of the crack tip, increase the fracture energy, thereby slowing down or even preventing the crack from passing through the crystal phase and the possible interface, and improving the mechanical properties such as the impact resistance, drop resistance, and scratch resistance of the glass. It can be widely used in the field of screen protection for mobile terminal display devices with requirements such as ultra-thin, high transparency, and high strength.

[0004] However, during chemical strengthening, due to the structural differences between the glass phase and the crystal phase in the glass-ceramics, it is difficult to increase the surface compressive stress of the glass-ceramics, resulting in insufficient surface hardness of the strengthened glass-ceramics and poor scratch resistance. Summary of the Invention

[0005] The main object of the present invention is to propose a glass-ceramics and a preparation method thereof, aiming to solve the problem of poor surface hardness and scratch resistance of glass-ceramics in the prior art.

[0006] To achieve the above object, the present invention proposes a glass-ceramics, which comprises the following components in mass percentage:

[0007] SiO2 67.3wt% - 70.8wt%, Al2O3 2wt% - 4wt%, P2O5 2.5wt% - 4wt%, Li2O 10wt% - 13wt%, Na2O 2.2wt% - 5wt%, K2O 1.2wt% - 3wt%, and ZrO2 6wt% - 9wt%.

[0008] In an embodiment, in the glass-ceramics, the mass percentage of ZrO2 is M1, the mass percentage of P2O5 is M2, the mass percentage of Li2O is M3, the mass percentage of Na2O is M4, the mass percentage of K2O is M5, and the mass percentage of Al2O3 is M6:

[0009] The M1, the M2, and the M3 satisfy the formula: 0.2 < A = (M1 - M2) / M3 ≤ 0.5; and / or,

[0010] The M4, the M5, and the M3 satisfy the formula: 0.46 < B = (M4 - M5) / M3 ≤ 0.52; and / or,

[0011] The M1, the M5, and the M6 satisfy the formula: 0.75 < C = (M1 - M5) / M6 ≤ 3.9.

[0012] In one embodiment, the thickness of the glass-ceramics is 0.3 mm to 2 mm; and / or,

[0013] The average particle size of the crystals in the glass-ceramics is < 30 nm.

[0014] In one embodiment, the crystal phase with the largest mass fraction in the glass-ceramics is Li2Si2O5; and / or,

[0015] The crystallinity of the glass-ceramics is > 50 wt%; and / or,

[0016] The average transmittance of the glass-ceramics with a thickness of ≤ 2 mm in the wavelength range of 380 nm to 780 nm is ≥ 90.6%; and / or,

[0017] The b value of the glass-ceramics with a thickness of ≤ 2 mm is ≤ 0.5; and / or,

[0018] The haze of the glass-ceramics with a thickness of ≤ 2 mm is ≤ 0.2%.

[0019] In one embodiment, the Vickers hardness of the glass-ceramics is > 850 HV; and / or,

[0020] The surface compressive stress of the glass-ceramics is > 330 MPa, the compressive stress at a depth of 30 nm from the surface to the inside of the glass-ceramics is > 230 MPa, and the stress layer depth of the glass-ceramics is > 110 μm; and / or,

[0021] The drop height of the glass-ceramics is ≥ 2 m.

[0022] The present invention also provides a method for preparing glass-ceramics, comprising the following steps:

[0023] S10. Mix a silicon source, an aluminum source, a phosphorus source, a lithium source, a sodium source, a potassium source, and a zirconium source, melt them, and prepare a green sheet glass;

[0024] S20. Perform nucleation treatment and crystallization treatment on the green sheet glass, and cool it to obtain a basic glass-ceramics;

[0025] S30. Preheat the basic glass-ceramics, and immerse the preheated basic glass-ceramics in a mixture of potassium salt and sodium salt for ion exchange treatment to obtain the glass-ceramics.

[0026] In one embodiment, in step S10:

[0027] The melting temperature is 1380 °C to 1450 °C; and / or,

[0028] The steps for preparing the plain glass plate include: clarification, homogenization, forming, annealing, and cutting. The forming methods include float forming, overflow forming, rolling, slot-draw or frit casting.

[0029] In one embodiment, in step S20:

[0030] The temperature of the nucleation treatment is 540 - 600 °C; and / or,

[0031] The time of the nucleation treatment is 2 - 4 h; and / or,

[0032] The temperature of the crystallization treatment is 720 - 760 °C; and / or,

[0033] The time of the crystallization treatment is 1 - 3 h.

[0034] In one embodiment, in step S30:

[0035] The temperature of the preheating is 350 - 390 °C; and / or,

[0036] The time of the preheating is 25 - 35 min.

[0037] In one embodiment, in step S30:

[0038] The mass percentage of potassium salt in the molten mixed salt is 60 - 75%, and the mass percentage of sodium salt in the molten mixed salt is 25 - 40%; and / or,

[0039] The temperature of the ion exchange treatment is 460 - 500 °C; and / or,

[0040] The time of the ion exchange treatment is 3 - 7 h.

[0041] In the technical solution of the present invention, by adjusting the composition and mass percentage of the glass-ceramics, the structures of the glass phase and the crystalline phase are improved, and the problems of low surface compressive stress and poor scratch resistance of the glass-ceramics are solved. The crystalline phase with the largest mass ratio in the glass-ceramics of the present invention is the lithium disilicate (Li2Si2O5) crystalline phase, that is, the main crystalline phase; the glass-ceramics have high hardness, good compressive stress and anti-drop height performance, good optical properties, large crystallinity, and small and uniform particle size, and can be applied to the field of screen protection for mobile terminal display devices with requirements such as ultra-thin, high transparency, and super strength.

[0042] The realization, functional characteristics, and advantages of the object of the present invention will be further described in conjunction with the embodiments. Specific Embodiments

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. For those not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution where both A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0044] Glass-ceramics is a composite material composed of an amorphous glass matrix and evenly distributed crystal phases. It combines the advantages of glass and ceramics and has excellent physical, chemical, and mechanical properties.

[0045] The crystal phase in the glass-ceramics can cause the bending and blunting of the crack tip, increase the fracture energy, thereby slowing down or even preventing the crack from passing through the crystal phase and the possible interface, and improving the mechanical properties such as impact resistance, drop resistance, and scratch resistance of the glass. It can be widely used in the field of screen protection for mobile terminal display devices with requirements such as ultra-thin, high transparency, and high strength.

[0046] Then, during chemical strengthening, due to the structural differences between the glass phase and the crystal phase in the glass-ceramics, it is difficult to increase the surface compressive stress of the glass-ceramics, resulting in insufficient surface hardness of the strengthened glass-ceramics and poor scratch resistance.

[0047] In view of this, the present invention provides a glass-ceramics, which comprises the following components in mass percentage:

[0048] SiO2 67.3wt% - 70.8wt%, Al2O3 2wt% - 4wt%, P2O5 2.5wt% - 4wt%, Li2O 10wt% - 13wt%, Na2O 2.2wt% - 5wt%, K2O 1.2wt% - 3wt%, and ZrO2 6wt% - 9wt%.

[0049] In the technical solution of the present invention, by adjusting the composition and mass percentage of the glass-ceramics, the structures of the glass phase and the crystallized phase are improved, solving the problems of relatively low surface compressive stress and poor scratch resistance of the glass-ceramics. The crystallized phase with the largest mass percentage in the glass-ceramics of the present invention is the lithium disilicate (Li2Si2O5) crystallized phase, that is, the main crystallized phase; the glass-ceramics have high hardness, good compressive stress and anti-drop height performance, good optical performance, large crystallinity, and small and uniform particle size, and can be applied to the field of screen protection for mobile terminal display devices with requirements such as ultra-thin, high transparency, and super strength.

[0050] In the technical solution of the present invention, SiO2 mainly exists in the form of silicon-oxygen tetrahedrons (SiO4) in the glass. These tetrahedrons are connected by covalent bonds to form a highly stable three-dimensional network structure; the mass percentage of SiO2 within the above range helps to reduce the thermal expansion coefficient of the glass, improve the thermal stability, heat resistance, chemical stability, and softening temperature of the glass, and can provide a source of SiO2 for the formation of the crystallized phase during the crystallization process of the glass; if the content of SiO2 is too high, there is a lack of sufficient network modifiers such as sodium oxide in the three-dimensional network structure of silicon dioxide to destroy the three-dimensional network structure of SiO2, making it easier for the SiO2 network to remain intact and tend to crystallize to form quartz or quartz solid solution during the cooling process; on the contrary, if the content of SiO2 is low, it is difficult to form glass. Therefore, the content of SiO2 is selected to be 67.3 wt% to 70.8 wt%.

[0051] In the technical solution of the present invention, after Al2O3 enters the glass network, it will exist in the form of aluminum-oxygen tetrahedrons (AlO4) or aluminum-oxygen hexahedrons (AlO6). Among them, the aluminum atom is the central cation with a positive charge of +3. Therefore, the mass percentage of Al2O3 within the above range can better increase the cation charge density in the three-dimensional network of the glass, help balance the negative charge in the network, reduce the formation of defects and pores, and thus improve the stability of the glass network structure. If the content of Al2O3 is too high, it can significantly increase the crystallization temperature of the glass-ceramics, inhibit the crystallization ability of the base glass, and it is difficult to form the lithium disilicate crystallized phase. Therefore, the content of Al2O3 is selected to be 2 wt% to 4 wt%.

[0052] In the technical solution of the present invention, P2O5 is used as a nucleating agent, which can better reduce the nucleation energy barrier. Li2O and P2O5 in the glass composition first react to form lithium phosphate (Li3PO4) crystal phase. The formation of Li3PO4 drives or induces the reaction between Li2O and SiO2 in the glass to form lithium silicate (Li2SiO3). Li2SiO3 further reacts with SiO2 to finally form the lithium disilicate (Li2Si2O5) crystal phase. If the content of P2O5 is too high, lithium metasilicate will precipitate during the crystallization process, resulting in too little glass phase, unable to form enough Li2Si2O5 crystal phase, and promoting the precipitation of quartz phase, making it difficult to obtain crystallized glass with high permeability. Therefore, considering comprehensively, the content of P2O5 is 2.5wt% - 4wt%.

[0053] In the technical solution of the present invention, Li2O promotes the formation of Li3PO4 during the crystallization process, which helps to form the lithium disilicate crystal phase during the crystallization process. If the content of Li2O is too high, it is difficult to obtain a chemically stable glass composition; if the content of Li2O is too low, it is difficult to form a crystal phase. Therefore, the content of Li2O is selected to be 10wt% - 13wt%.

[0054] In the technical solution of the present invention, Na2O with a mass percentage of 2.2% or more will weaken the formation ability of spodumene and is beneficial to the formation of lithium disilicate; at the same time, Na + can exchange with K + in the potassium nitrate molten salt soaked during the chemical strengthening process to be strengthened, and then generate high compressive stress on the glass surface and improve the glass strength. Therefore, the content of Na2O in the final glass-ceramics is 2.2wt% - 5wt%.

[0055] In the technical solution of the present invention, the introduction of K2O can improve the difference between the glass phase and the crystal phase. At high temperatures, K2O can weaken the ability of crystal growth, making the crystallization ability of the glass phase weaker; at the same time, K2O with a mass percentage of 1.2% or more is beneficial to improving the internal stress strength of the glass after strengthening the glass-ceramics. Therefore, the content of K2O in the final glass-ceramics is 1.2wt% - 3wt%.

[0056] In the technical solution of the present invention, ZrO2 is also used as a nucleating agent to promote the formation of spodumene (LiAlSi2O6). Its mass percentage within the above range helps to reduce the grain size during the crystallization process and improve the uniformity of crystallization, thereby improving the transmittance of the glass. Too high content of ZrO2 will cause the existence of unmolten ZrO2 in the glass, resulting in non-uniform crystallization of the glass. Therefore, the content of ZrO2 is selected to be 6wt% - 9wt%.

[0057] In some embodiments of the present invention, in the glass-ceramics, the mass percentage of ZrO2 is M1, the mass percentage of P2O5 is M2, the mass percentage of Li2O is M3, the mass percentage of Na2O is M4, the mass percentage of K2O is M5, and the mass percentage of Al2O3 is M6:

[0058] M1, M2, and M3 satisfy the formula: 0.2 < A = (M1 - M2) / M3 ≤ 0.5; and / or, M4, M5, and M3 satisfy the formula: 0.46 < B = (M4 - M5) / M3 ≤ 0.52; and / or, M1, M5, and M6 satisfy the formula: 0.75 < C = (M1 - M5) / M6 ≤ 3.9.

[0059] In the technical solution of the present invention, controlling the mass relationship of ZrO2, P2O5, and Li2O within the range of 0.2 < A ≤ 0.5 can, on the one hand, ensure that the glass of the present invention nucleates and crystallizes at a lower temperature; on the other hand, it can ensure that the size of the formed crystals is uniform and the particle size is < 50 nm, meeting the basic requirements of optical visibility. In some embodiments of the present invention, the thickness of the glass-ceramics is 0.3 mm to 2 mm; and / or, the average particle size of the crystals of the glass-ceramics is < 30 nm, preferably 10 nm to < 30 nm, further preferably 15 nm to < 30 nm, more preferably 20 nm to < 30 nm, that is, the glass-ceramics achieve a lower crystal particle size.

[0060] In the technical solution of the present invention, controlling the mass relationship of Na2O, K2O, and Li2O within the range of 0.46 < B ≤ 0.52 can ensure that Na2O and K2O weaken or inhibit the generation of the spodumene crystal phase better, reduce the size of the crystal grains during the crystallization process, so that the final crystal phase is mainly Li2S i2 O5, thereby further improving the transmittance of the glass and reducing the haze. In some embodiments of the present invention, the crystal phase with the largest mass fraction in the glass-ceramics is Li2Si2O5; and / or, the crystallinity of the glass-ceramics is > 50 wt%, preferably > 50 wt% to 75%, further preferably > 50 wt% to 70%, more preferably > 50 wt% to 65%; and / or, the average transmittance of the glass-ceramics with a thickness of ≤ 2 mm in the wavelength range of 380 nm to 780 nm is ≥ 90.6%, preferably 90.6% to 93%, further preferably 90.6% to 92%, more preferably 90.6% to 91%; and / or, the b value of the glass-ceramics with a thickness of ≤ 2 mm is ≤ 0.5, preferably 0.2 to 0.5, further preferably 0.3 to 0.5, more preferably 0.35 to 0.5; and / or, the haze of the glass-ceramics with a thickness of ≤ 2 mm is ≤ 0.2%, that is, the crystallinity and light transmittance of the glass-ceramics are improved, and the yellow degree b value and haze are reduced, which is convenient for application.

[0061] In the technical solution of the present invention, the mass relationship of ZrO2, K2O and Al2O3 is controlled such that 0.75 < C ≤ 3.9. The range of C can also be 1 - 3.5, 1 - 3, 1.5 - 3.5, 1.5 - 3, 1.5 - 2.5, 1 - 2, etc. Among them, the difference between ZrO2 and K2O (ZrO2 content is higher than K2O) increases the spatial difference between the glass phase and the microcrystalline phase. The high modulus and strong nucleation ability of ZrO2 make the microcrystalline phase denser, while the presence of K2O weakens the strength of the glass network and makes the glass phase relatively loose. This difference leads to the formation of more "void" regions between the microcrystalline phase and the glass phase, and the formation of continuous ion exchange channels between the glass phases, improving the internal stress strength of the glass after strengthening the glass-ceramics. After chemical strengthening, the glass-ceramics can form a large compressive stress and ion exchange depth, and have good hardness and anti-drop properties. In some embodiments of the present invention, the Vickers hardness of the glass-ceramics > 850 HV, and can also be preferably > 850 HV - 1000 HV, further preferably > 850 HV - 950 HV, more preferably > 850 HV - 900 HV; and / or, the surface compressive stress of the glass-ceramics > 330 MPa, and can also be preferably > 330 MPa - 800 MPa, further preferably > 330 MPa - 600 MPa, more preferably > 330 MPa - 500 MPa; the compressive stress at a depth of 30 nm from the surface to the inside of the glass-ceramics > 230 MPa, and can also be preferably > 230 MPa - 400 Mpa, further preferably > 230 MPa - 300 Mpa; the stress layer depth of the glass-ceramics > 110 μm, such as 120 μm, 130 μm, 140 μm, 150 μm, etc., and can also be preferably > 110 μm - 160 μm, further preferably > 110 μm - 150 μm, more preferably > 110 μm - 140 μm; and / or, the drop height of the glass-ceramics ≥ 2 m, and can also be preferably 2 m - 3 m, further preferably 2 m - 2.5 m, which greatly improves the hardness, compressive stress and anti-drop performance of the glass-ceramics.

[0062] It should be noted that simultaneously controlling the three parameters A, B, and C within the above ranges can make the glass-ceramics have lithium disilicate crystal phase as the single crystal phase, and improve the hardness, compressive stress, anti-drop height performance, optical performance, crystallinity, crystal distribution uniformity of the glass-ceramics, and reduce the crystal particle size of the microcrystalline phase.

[0063] The present invention also provides a method for preparing glass-ceramics, comprising the following steps:

[0064] S10. Mix a silicon source, an aluminum source, a phosphorus source, a lithium source, a sodium source, a potassium source and a zirconium source, melt them, and prepare a green sheet glass;

[0065] S20. Subject the raw board glass to nucleation treatment and crystallization treatment, and then cool it to obtain the basic glass-ceramics.

[0066] S30. Preheat the basic glass-ceramics, and then immerse the preheated basic glass-ceramics into a molten mixture of potassium salt and sodium salt for ion exchange treatment to obtain the glass-ceramics.

[0067] In the technical solution of the present invention, by adding a potassium source to the raw material components, the melting temperature of the raw materials is reduced, and the growth rate of crystal size is inhibited during the nucleation treatment and crystallization treatment, reducing the possibility of crystallization of the glass phase; in step S30, performing heat preservation pretreatment on the basic glass-ceramics can ensure that crystal nuclei are evenly distributed throughout the glass matrix, avoiding local over-crystallization or under-crystallization phenomena; immersing the preheated basic glass-ceramics into a molten mixture of potassium salt and sodium salt can enable potassium ions in the mixed salt to enter and exchange ions with sodium ions and lithium ions in the glass more quickly through the ion exchange channels formed between the crystal phase and the glass phase. When K + enters the glass surface and replaces the smaller Na + or Li + , a compressive stress layer will be generated on the glass surface, thereby improving the scratch resistance of the glass-ceramics; sodium ions in the mixed salt also exchange ions with lithium ions in the glass through the same channels; the through channels reduce the resistance of ion exchange and improve the exchange efficiency. The glass-ceramics prepared by the preparation method of the present invention have excellent physical and chemical properties and mechanical properties, and can be used as the front cover or back cover of a touch display screen, or for the protection of other electronic intelligent terminals, etc.

[0068] In some embodiments of the present invention, in step S10: the silicon source includes high-purity quartz sand; and / or, the aluminum source includes calcined alumina and / or feldspar, or other aluminum-containing inorganic salts; and / or, the phosphorus source includes aluminum metaphosphate and / or phosphorus pentoxide, etc.; and / or, the lithium source includes lithium carbonate and / or lithium oxide, or other lithium-containing inorganic salts; and / or, the sodium source includes sodium carbonate and / or sodium sulfate, or other sodium-containing inorganic salts; and / or, the potassium source includes potassium carbonate and / or potassium sulfate, or other potassium-containing inorganic salts; and / or, the zirconium source includes zircon powder and / or zirconia, or other zirconium-containing inorganic salts. That is, the sources of the silicon source, aluminum source, phosphorus source, lithium source, sodium source, potassium source, and zirconium source in the present invention can be adjusted according to actual situations. Preferably, the SiO2 in the composition of the glass of the present invention is introduced by high-purity quartz sand, Al2O3 is introduced by calcined alumina and feldspar, Li2O is mainly introduced by lithium carbonate, Na2O is mainly introduced by sodium carbonate and sodium sulfate, K2O is mainly introduced by potassium carbonate, ZrO2 is introduced by zircon powder, and P2O5 is introduced by aluminum metaphosphate.

[0069] In some embodiments of the present invention, in step S10: the melting temperature is 1380°C to 1450°C; and / or, the steps of preparing the plain glass plate include: clarification, homogenization, forming, annealing and cutting, and the forming method includes float forming, overflow forming, rolling, slot drawing or frit casting. Due to the limitation of the mass ratio of each component in the glass of the present invention, the melting temperature of the raw materials of the present invention after being calculated and mixed according to the final ratio is relatively low, and the energy consumption is low.

[0070] In some embodiments of the present invention, in step S20: the temperature of the nucleation treatment is 540 - 600°C; and / or, the time of the nucleation treatment is 2 - 4h; and / or, the temperature of the crystallization treatment is 720 - 760°C; and / or, the time of the crystallization treatment is 1 - 3h. That is, the temperature of the nucleation treatment can be 540°C, 580°C or 600°C, and the time of the nucleation treatment can be 2h, 3h or 4h. Controlling the time and temperature of the nucleation treatment within the above ranges can ensure that more and more uniformly distributed crystal nuclei are generated in the plain glass plate. The temperature of the crystallization treatment can be 720°C, 740°C or 760°C, and the time of the crystallization treatment can be 1h, 2h or 3h. Controlling the crystallization temperature and crystallization time within the above ranges can ensure that the final crystal phase is mainly lithium disilicate, and the optical properties of the glass-ceramics are better.

[0071] In some embodiments of the present invention, in step S30: the preheating temperature is 350 - 390°C; and / or, the preheating time is 25 - 35min. The preheating temperature and time within the above ranges can ensure that the crystal nuclei are uniformly distributed throughout the glass matrix, avoiding local over-crystallization or under-crystallization phenomena.

[0072] In some embodiments of the present invention, in step S30: the mass percentage of potassium salt in the molten mixed salt is 60 - 75%, and the mass percentage of sodium salt in the molten mixed salt is 25 - 40%; and / or, the temperature of the ion exchange treatment is 460 - 500°C; and / or, the time of the ion exchange treatment is 3 - 7h. By controlling the mass percentages of sodium salt and potassium salt in the molten mixed salt within the above ranges, a better ion exchange effect can be ensured, a larger compressive stress layer is formed in the glass, and the hardness, scratch resistance and drop resistance of the glass surface are improved. The temperature of the ion exchange treatment can be 460°C, 480°C or 500°C, and the time of the ion exchange treatment can be 3h, 5h or 7h. The time and temperature of the ion exchange within the above ranges can ensure that potassium ions with larger radii and the like more fully replace some sodium ions and lithium ions with smaller radii in the glass, so that a larger compressive stress layer is formed in the glass, and the hardness, scratch resistance and drop resistance of the glass surface are improved.

[0073] The technical solution of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0074] Example 1

[0075] Example 1 provides a glass-ceramic, comprising the following components in mass percentage:

[0076] SiO2 67.3wt%, Al2O3 2wt%, P2O5 2.5wt%, Li2O 13wt%, Na2O 5wt%, K2O 1.2wt%, and ZrO2 9wt%;

[0077] The glass-ceramic is prepared by the following preparation method:

[0078] S10. According to the glass composition, calculate the required glass raw materials, namely high-purity quartz sand, calcined alumina, feldspar, aluminum metaphosphate, lithium carbonate, sodium carbonate and sodium sulfate, potassium carbonate, mix all the raw materials, melt them, and then clarify, homogenize, shape, anneal, and finally cut to prepare a plain plate glass; the melting temperature is 1420 °C;

[0079] S20. Perform nucleation treatment and crystallization treatment on the plain plate glass, and then cool it to obtain a basic glass-ceramic; the temperature of the nucleation treatment is 600 °C and the time is 2 h; the temperature of the crystallization treatment is 760 °C and the time is 1 h;

[0080] S30. Preheat the basic glass-ceramic, and immerse the preheated basic glass-ceramic in a mixture of potassium nitrate and sodium nitrate for ion exchange treatment to obtain a glass-ceramic with the above mass percentage components; the mass percentages of potassium nitrate and sodium nitrate are 85% and 25% respectively; the preheating temperature is 370 °C and the time is 30 min; the ion exchange temperature is 500 °C and the time is 3 h.

[0081] Examples 2 to 7 are similar to Example 1, and the differences are shown in Table 1:

[0082] Table 1 Setting differences between Examples 1 to 7 and Comparative Example 1

[0083]

[0084] Performance test

[0085] Perform tests on the crystal phase, crystallinity, average grain size, b value, transmittance, haze, Vickers hardness, compressive stress value, compressive stress value at a depth of 30 microns, ion exchange depth of the compressive stress layer, and the whole machine sandpaper drop performance of Examples 1 to 7 and Comparative Example 1. The test methods are as follows:

[0086] Crystal phase and crystallinity: The crystal phase was determined by comparing the X-ray diffraction (XRD) peaks with the database spectra, and the crystallinity was obtained by calculating the proportion of the diffraction intensity of the crystalline phase in the overall spectral intensity using the Rietveld method;

[0087] Average grain size: It was measured using a scanning electron microscope (SEM). That is, the glass-ceramics were surface-treated in hydrofluoric acid, then chromium was sprayed and coated on the surface of the treated glass-ceramics, and surface scanning was carried out under the SEM to observe the diameter of the particles. The average grain size was obtained by summing up the average diameter sizes of all grain profiles and dividing by the number of grains in the SEM image;

[0088] b value: The color b value was tested using a Datacolor650 ultra-high-precision desktop spectrophotometer;

[0089] Transmittance: It was measured using a Lambda950 ultraviolet-visible spectrophotometer from Perkin Elmer, USA, with reference to the GB / T 40415 standard;

[0090] Haze: The haze of the sample was measured using a SUGA optical HZ-V3 haze meter with reference to the GB / T 2410 standard;

[0091] Vickers hardness: The Vickers hardness of the glass was measured with reference to GB / T 4340.4-2022, and the unit is HV;

[0092] Compressive stress detection: A surface stress meter, the Nisshinbo FSM-6000LE+SLP-2000 from Japan, was used to test each example after ion exchange. 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 microns after the strengthened glass sample is strengthened by mixed salts; DOC refers to the ion exchange depth of the compressive stress layer of the glass-ceramics;

[0093] Whole machine sandpaper drop performance: It was measured by a mobile phone controlled drop test machine. The specific test conditions were: 180-mesh sandpaper, total weight of 195 g, base height of 30 cm, increasing by 10 cm, and 1 drop at each height until it broke;

[0094] The test results are shown in Table 2.

[0095] Table 2 Performance tests of the glass-ceramics prepared in Examples 1-7 and Comparative Example 1

[0096]

[0097] As can be seen from Table 2 and Examples 1-7, when 0.2 < A ≤ 0.5, 0.46 < B ≤ 0.52, and 0.75 < C ≤ 3.9 are reasonably controlled, the crystallinity of the glass-ceramics > 50 wt%, the average particle size of the crystals < 30 nm, and the main crystal phase of the glass-ceramics is Li2Si2O5; the average transmittance of the 0.6 mm glass-ceramics at a wavelength of 560 nm ≥ 90.6%; the b value of the glass-ceramics (with a thickness of 0.6 mm) ≤ 0.5, the haze of the glass-ceramics ≤ 0.2%, the surface compressive stress (CS) of the glass-ceramics after chemical strengthening > 330 MPa, the compressive stress at a depth of 30 nm from the glass surface to the interior (CS30) > 230 MPa, the depth of the stress layer (DOC) > 110 μm, the Vickers hardness of the glass-ceramics > 850 HV, and the anti-drop height ≥ 2 m. After chemical strengthening, the glass-ceramics have the characteristics of high hardness and excellent anti-drop performance.

[0098] In Comparative Example 1, A = 0.15, C = 0.53, and B = 9.23, none of which are within the requirements of the present invention. After chemical strengthening, the glass-ceramics have low hardness and poor anti-drop performance.

[0099] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the patent protection scope of the present invention.

Claims

1. A glass-ceramic, characterized in that: The glass-ceramics includes the following components by mass percentage: SiO2 67.3wt% - 70.8wt%, Al2O3 2wt% - 4wt%, P2O5 2.5wt% - 4wt%, Li2O 10wt% - 13wt%, Na2O 2.2wt% - 5wt%, K2O 1.2wt% - 3wt%, and ZrO2 6wt% - 9wt%.

2. The glass-ceramic according to claim 1, characterized in that: In the glass-ceramics, the mass percentage of ZrO2 is M1, the mass percentage of P2O5 is M2, the mass percentage of Li2O is M3, the mass percentage of Na2O is M4, the mass percentage of K2O is M5, and the mass percentage of Al2O3 is M6: The M1, the M2 and the M3 satisfy the formula: 0.2 < A = (M1 - M2) / M3 ≤ 0.5; and / or, The M4, the M5 and the M3 satisfy the formula: 0.46 < B = (M4 - M5) / M3 ≤ 0.52; and / or, The M1, the M5 and the M6 satisfy the formula: 0.75 < C = (M1 - M5) / M6 ≤ 3.

9.

3. The glass-ceramic according to claim 1, characterized in that: The thickness of the glass-ceramics is 0.3mm - 2mm; and / or, The average particle size of the crystals in the glass-ceramics < 30nm.

4. The glass-ceramic according to claim 1, characterized in that: The crystal phase with the largest mass proportion in the glass-ceramics is Li2Si2O5; and / or, The crystallinity of the glass-ceramics > 50wt%; and / or, The average transmittance of the glass-ceramics with a thickness ≤ 2mm in the wavelength range of 380nm - 780nm ≥ 90.6%; and / or, The b value of the glass-ceramics with a thickness ≤ 2mm ≤ 0.5; and / or, The haze of the glass-ceramics with a thickness ≤ 2mm ≤ 0.2%.

5. The glass-ceramic according to claim 1, characterized in that: The Vickers hardness of the glass-ceramics > 850HV; and / or, The surface compressive stress of the glass-ceramics > 330MPa, the compressive stress at a depth of 30nm from the surface to the inside of the glass-ceramics > 230MPa, and the stress layer depth of the glass-ceramics > 110μm; and / or, The drop height of the glass-ceramics ≥ 2m.

6. A method for preparing glass-ceramics according to any one of claims 1 to 5, characterized in that: It includes the following steps: S10. Mix a silicon source, an aluminum source, a phosphorus source, a lithium source, a sodium source, a potassium source and a zirconium source, melt them, and prepare a green sheet glass. S20. Perform nucleation treatment and crystallization treatment on the green sheet glass, and cool it to obtain a basic glass-ceramics. S30. Preheat the basic glass-ceramics, and immerse the preheated basic glass-ceramics in a molten mixture of potassium salt and sodium salt for ion exchange treatment to obtain the glass-ceramics.

7. The method for preparing glass-ceramics according to claim 6, characterized in that: In step S10: The melting temperature is 1380°C - 1450°C; and / or, The step of preparing the green sheet glass includes: clarification, homogenization, forming, annealing and cutting, and the forming method includes float forming, overflow forming, rolling, slot-down or frit casting forming.

8. The method for preparing glass-ceramics according to claim 6, characterized in that: In step S20: The nucleation treatment temperature is 540 - 600°C; and / or, The nucleation treatment time is 2 - 4h; and / or, The crystallization treatment temperature is 720 - 760°C; and / or, The crystallization treatment time is 1 - 3h.

9. The method for preparing glass-ceramics according to claim 6, characterized in that: In step S30: The preheating temperature is 350-390° C.; and / or, The preheating time is 25 to 35 minutes.

10. The method for preparing glass-ceramics according to claim 6, characterized in that: In step S30: The mass percentage of potassium salt in the molten mixed salt is 60-75%, and the mass percentage of sodium salt in the molten mixed salt is 25-40%; and / or, The temperature of the ion exchange treatment is 460-500° C.; and / or, The time of the ion exchange treatment is 3 to 7 hours.

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