A triclinic nepheline glass-ceramic and a preparation method and application thereof

Abstract

The application relates to the technical field of glass ceramics, and discloses a tri-clinic nepheline glass ceramic as well as a preparation method and application thereof. The glass ceramic comprises the following components in terms of molar percentage: 43-58 mol% SiO2, 15-27 mol% Al2O3, 20-30 mol% Na2O, 0-10 mol% Li2O, 0-10 mol% K2O, 0-5 mol% P2O5 and 0-3 mol% ZrO2. The glass ceramic provided by the application has a crystallinity of more than 80%, a crystal size of less than 90 nm, an average transmittance of more than 90% in a visible light band, and a crystal phase composition containing only a main crystal phase tri-clinic nepheline phase or containing a secondary crystal phase nepheline phase and a phosphate phase. The reduction or removal of the phosphate phase in the crystal phase improves the chemical stability of the glass ceramic and enables chemical strengthening.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of glass ceramics, in particular to a tri-clinic nepheline glass ceramic and a preparation method and application thereof. BACKGROUND

[0002] Glass ceramics are a kind of composite materials combined with crystal phase and glass phase, which are prepared by high-temperature melting, forming and heat treatment. Compared with glass, glass ceramics contain more stable nano-crystal structure, and thus have higher mechanical strength and lower thermal expansion coefficient, so they are widely used in electronic devices, automobiles, buildings and other fields.

[0003] Nepheline glass ceramics have good mechanical strength and can be strengthened by known ion exchange method. The existing nepheline glass ceramics contain main phase nepheline phase and secondary phase phosphate phase, wherein the nepheline crystal can improve the mechanical strength of the glass ceramic, and the phosphate crystal is formed at a lower temperature than the nepheline crystal and nucleates the crystallization of nepheline at a fine scale (e.g., about tens of nanometers scale). However, the chemical stability of the phosphate phase is poor, and its presence reduces the corrosion resistance of the nepheline glass ceramic, which is not conducive to the implementation of subsequent chemical strengthening and cleaning steps of the glass ceramic, resulting in a decrease in the yield rate and production efficiency in the production process. SUMMARY

[0004] The present application aims to at least solve one of the above technical problems in the prior art. To this end, one of the objects of the present application is to provide a glass ceramic; the second object of the present application is to provide a preparation method of the glass ceramic; the third object of the present application is to provide a chemically strengthened glass ceramic; the fourth object of the present application is to provide a preparation method of the chemically strengthened glass ceramic; and the fifth object of the present application is to provide an application of the glass ceramic or the chemically strengthened glass ceramic.

[0005] To achieve the above objects, the technical solution adopted by the present application is as follows:

[0006] The first aspect of the present application provides a glass ceramic, which comprises the following components in terms of mole percentage:

[0007] 43-58 mol% SiO2;

[0008] 15-27 mol% Al2O3;

[0009] 20-30 mol% Na2O;

[0010] 0-10 mol% Li2O;

[0011] 0-10 mol% K2O;

[0012] 0-5 mol% P2O5;

[0013] 0-3 mol% Zr02.

[0014] Preferably, the glass-ceramic further comprises, in mole percent, the following components: 0-10 mol% ZnO;

[0015] 0-10 mol% CaO;

[0016] 0-10 mol% MgO;

[0017] 0-10 mol% SrO;

[0018] 0-10 mol% B203;

[0019] 0-10 mol% BaO.

[0020] Preferably, the glass-ceramic further comprises, in mole percent, the following components: 0-4 mol% ZnO;

[0021] 0-3 mol% CaO;

[0022] 0-3 mol% MgO;

[0023] 0-2 mol% SrO;

[0024] 0-3 mol% B203.

[0025] Preferably, the glass-ceramic comprises, in mole percent, the following components: 43-58 mol% Si02;

[0026] 15-23 mol% Al203;

[0027] 21-30 mol% Na20;

[0028] 0-10 mol% K20;

[0029] 1-4 mol% P205;

[0030] 0.3-3 mol% Zr02.

[0031] Preferably, the glass-ceramic comprises, in mole percent, the following components: 43-58 mol% Si02;

[0032] 15-25 mol% Al203;

[0033] 21-30 mol% Na20;

[0034] 0-10 mol% Li20;

[0035] 1-4 mol% P205;

[0036] 0-2 mol% Zr02.

[0037] Preferably, the glass-ceramic comprises, in mole percent, the following components: 48-58 mol% Si02;

[0038] 15-20 mol% Al203;

[0039] 21-30 mol% Na20;

[0040] 1.5-3.5 mol% P205;

[0041] 0.3-2 mol% Zr02.

[0042] Preferably, the glass-ceramic comprises, in mole percent, the following components:

[0043] 43-53 mol% Si02;

[0044] 18-25 mol% Al203;

[0045] 20-24 mol% Na20;

[0046] 2-6 mol% Li20;

[0047] 0-2 mol% K20;

[0048] 2.5-5 mol% P205.

[0049] Preferably, the content of Si02in the glass-ceramic can also be any one of 43-56 mol%, 43-54 mol%, 43-52 mol%, 45-58 mol%, 47-58 mol%, 49-58 mol%, 49-56 mol%, in mole percent. Si02, as the main component of the glass-ceramic, constitutes the glass matrix. In addition, Si02can be used as a viscosity enhancer for enhancing the glass forming ability while imparting mechanical durability to the glass.

[0050] Preferably, the content of Al203in the glass-ceramic can also be any one of 15-21 mol%, 17-25 mol%, 19-25 mol%, 19-23 mol%, in mole percent.

[0051] Preferably, the content of Na20 in the glass-ceramic can also be any one of 20-28 mol%, 20-26 mol%, 22-30 mol%, 24-30 mol%, 24-28 mol%, in mole percent.

[0052] Preferably, the content of K2O in the glass ceramic can also be any one of 0-8 mol%, 0-6 mol%, 2-10 mol%, 4-10 mol%, 4-8 mol% in terms of molar percentage.

[0053] Preferably, the content of Li2O in the glass ceramic can also be any one of 0-8 mol%, 0-6 mol%, 2-10 mol%, 4-10 mol%, 4-8 mol% in terms of molar percentage.

[0054] Preferably, the content of ZrO2 in the glass ceramic can also be 1-3 mol% in terms of molar percentage.

[0055] Preferably, the glass ceramic can also include a nucleating agent; the nucleating agent includes at least one of P2O5, ZrO2; the molar percentage content of P2O5 in the glass ceramic is 1-5 mol%; the molar percentage content of ZrO2 in the glass ceramic is 1-3 mol%; the ratio of the molar percentage content of P2O5 to ZrO2 is 0.25-4, which can be one of 4 / 1, 3 / 1, 2 / 1, 1, 1 / 2, 1 / 3, 1 / 4.

[0056] Preferably, the glass ceramic can also include a chemical clarifier; the chemical clarifier includes at least one of SnO2, As2O3, Sb2O3, F, Cl, Br, CeO2, Fe2O3, MnO2; when the chemical clarifier is selected from SnO2, As2O3, Sb2O3, F, Cl, Br, the mass percentage content in the glass ceramic is 0-3%, and is not 0, which can be one of 3wt%, 2wt%, 1wt%, 0.5wt%; when the chemical clarifier is selected from CeO2, Fe2O3, MnO2, the mass percentage content in the glass ceramic is 0-0.5%, and is not 0, which can be one of 0.5wt%, 0.4wt%, 0.3wt%, 0.2wt%, 0.1wt%.

[0057] Preferably, the glass ceramic can also include SnO2; the mass percentage content of SnO2 in the glass ceramic can be one of 0-3%, 0-2%, 0-1%, 0-0.5%, 0-0.1%. SnO2 is used as an agent to adjust various physical, melting, color or forming characteristics of the glass ceramic.

[0058] Preferably, the mass percentage content of As2O3, Sb2O3 or a combination thereof in the glass ceramic is 0-0.05%, i.e. the glass ceramic can not contain As2O3, Sb2O3 or a combination thereof.

[0059] Preferably, the glass ceramic is composed of a main crystal phase, a secondary crystal phase and a residual glass phase, wherein the mass percentage of the main crystal phase is 30-90%, and the mass percentage of the secondary crystal phase is 0-49%.

[0060] Preferably, the mass percentage of the main crystal phase is 60-85%.

[0061] Preferably, the mass percentage of the secondary crystal phase is 0-10%.

[0062] Preferably, the glass ceramic has a regionally divided grid-like microstructure; the diameter of the grid is 30-300 nm; the regionally divided grid-like microstructure can limit crystal growth and has a clear self-limiting crystallization effect.

[0063] Preferably, the average transmittance of the glass ceramic is 65-93% at a wavelength of 380-780 nm when the thickness of the glass ceramic is 0.7 mm; further preferably, the average transmittance of the glass ceramic is 68-91% at a wavelength of 380-780 nm when the thickness of the glass ceramic is 0.7 mm.

[0064] Preferably, the main crystal phase comprises one of triclinic nepheline phase, triclinic nepheline and a solid solution crystal phase thereof.

[0065] Preferably, the triclinic nepheline comprises at least one of low-temperature triclinic nepheline and high-temperature triclinic nepheline; the low-temperature triclinic nepheline (NaAlSiO4, low-carnegieite) has an orthorhombic crystal system (Orthorhombic) and a Pmaa space group; the high-temperature triclinic nepheline (NaAlSiO4, high-carnegieite) has a cubic crystal system (Cubic).

[0066] Preferably, the solid solution comprises at least one of NaAlSiO4-SiO2 solid solution, (Na, K)AlSiO4 solid solution, (Na, K)AlSiO4-SiO2 solid solution, R(Al, Si)O4 (wherein R = Na, K, Mg, Ca, Ba or a vacancy), (K, Na)SiO4, CaO, SiO2; the R(Al, Si)O4 (wherein R = Na, K, Mg, Ca, Ba or a vacancy) is an orthorhombic (Pmaa) network silicate, and its structure is a "filled" derivative of the β-cristobalite form of silica; in the (Na, K)AlSiO4-SiO2 solid solution, Na is dominant over K.

[0067] Preferably, the secondary crystal phase comprises at least one of nepheline phase and phosphate phase.

[0068] Preferably, the mass of the nepheline phase is 0-39% of the mass of the glass-ceramic; further preferably, the mass of the nepheline phase is 0-10% of the mass of the glass-ceramic.

[0069] Preferably, the mass of the phosphate phase is 0-10% of the mass of the glass-ceramic; further preferably, the mass of the phosphate phase is 0-5% of the mass of the glass-ceramic.

[0070] Preferably, the nepheline phase is a hexagonal (P63) network silicate whose structure is a "filled" derivative of the β-cristobalite form of silica.

[0071] Preferably, the phosphate phase comprises a crystalline phosphate phase and an amorphous phosphate phase; the amorphous or crystalline phosphate phase can form at a lower temperature than the nepheline crystal; the amorphous or crystalline phosphate phase (about tens of nanometers) promotes the precipitation of triclinic nepheline and nepheline; the size of the crystalline phosphate phase is ≤ 30 nm; the amorphous phosphate phase is distributed in the glass-ceramic in a uniform or connected manner.

[0072] Preferably, the glass-ceramic comprises at least one of triclinic nepheline phase grains, nepheline phase grains, and phosphate phase grains; the main cross-sectional dimension of the grains is less than 90 nm; further preferably, the main cross-sectional dimension of the grains is 30-89 nm.

[0073] Preferably, the glass-ceramic has a haze of 0.1-0.3; further preferably, the glass-ceramic has a haze of 0.1-0.2; the haze is the percentage of transmitted light scattered outside an angle cone of ± 4.0° according to ASTM method D1003.

[0074] Preferably, the glass-ceramic has a crystallinity of 30-90 wt%; further preferably, the glass-ceramic has a crystallinity of 40-90 wt%; still further preferably, the glass-ceramic has a crystallinity of 50-90 wt%; yet further preferably, the glass-ceramic has a crystallinity of 60-90 wt%; most preferably, the glass-ceramic has a crystallinity of 65-85 wt%.

[0075] Preferably, the glass-ceramic is colorless and transparent.

[0076] Preferably, the glass-ceramic has a refractive index of 1.4-1.6.

[0077] Preferably, the glass-ceramic has a Vickers hardness of 5-8.5 GPa.

[0078] The second aspect of the present application provides a method for preparing the glass-ceramic of the first aspect of the present application, comprising the following steps:

[0079] S1, melting and mixing the components at 1400-1600℃ to obtain a precursor glass;

[0080] S2, heat treating the precursor glass to obtain the glass ceramic.

[0081] Preferably, in the step S1, the time for the mixed melting is 3-5h.

[0082] Preferably, in the step S1, after the mixed melting, the step of casting forming and annealing is further included; the annealing temperature is 550-700℃, and the time is 3-5h.

[0083] Preferably, in the step S1, the precursor glass can be a glass sheet or any other shape, and the glass sheet can be formed by rolling, float method, spin coating method, pressing method, etc., and the thickness is less than 5mm.

[0084] Preferably, in the step S2, the heat treatment method is selected from any one of one-step ceramming and two-step ceramming.

[0085] Preferably, the one-step ceramming is: heating the precursor glass from room temperature to 620-800℃ at a heating rate of 1-10℃ / min, and keeping the temperature for 0.5-8h to obtain the glass ceramic.

[0086] Preferably, the two-step ceramming is selected from any one of the following:

[0087] (1) heating the precursor glass from room temperature to 600-650℃ at a heating rate of 1-10℃ / min, keeping the temperature for 0.5-2h, then heating to 650-750℃ at a heating rate of 1-10℃ / min, keeping the temperature for 1-8h to obtain the glass ceramic;

[0088] (2) heating the precursor glass from room temperature to 700-800℃ at a heating rate of 1-10℃ / min, keeping the temperature for 1-2h, then heating to 800-850℃ at a heating rate of 1-10℃ / min, keeping the temperature for 2-4h to obtain the glass ceramic.

[0089] Preferably, after the heat treatment, the step of room temperature cooling is further included.

[0090] The third aspect of the present application provides a chemically strengthened glass ceramic, comprising the glass ceramic of the first aspect of the present application.

[0091] Preferably, the chemically strengthened glass ceramic can form a surface compressive stress in the range of 200-3000MPa, and the depth of the surface compressive stress is in the range of 10-160μm.

[0092] Preferably, the chemical strengthened glass ceramic has a Vickers hardness of 6.5-9 GPa.

[0093] The fourth aspect of the present application provides a method for preparing the chemical strengthened glass ceramic according to the third aspect of the present application, comprising the following steps:

[0094] The glass ceramic is placed in a mixed salt bath containing NaNO3 and / or KNO3 for single or multiple ion exchange, to obtain the chemical strengthened glass ceramic.

[0095] Preferably, the method for preparing the chemical strengthened glass ceramic uses a one-step strengthening method using K + Na+ in the glass ceramic is exchanged + to generate a compressive stress layer and improve the strength of the glass.

[0096] Preferably, the mass ratio of NaNO3 to KNO3 is 1:(0.25-4).

[0097] Preferably, the ion exchange temperature is 400-600℃.

[0098] Preferably, the ion exchange time is 1-12 h; further preferably, the ion exchange time is 2-10 h; still further preferably, the ion exchange time is 2-8 h; yet further preferably, the ion exchange time is 4-8 h.

[0099] The fifth aspect of the present application provides the glass ceramic according to the first aspect of the present application, or the chemical strengthened glass ceramic according to the third aspect of the present application, for use in electronic devices, transportation tools, construction, and explosion-proof fields.

[0100] Compared with the prior art, the present application has the following advantages:

[0101] 1) The glass ceramic provided by the present application has a crystallinity of more than 80%, a crystal size of less than or equal to 80 nm, an average transmittance in the visible light band of more than 90%, and a crystal phase composition containing only the main crystal phase triclinic nepheline phase or containing the secondary crystal phase nepheline phase and phosphate phase. The reduction or removal of the phosphate phase in the crystal phase improves the chemical stability of the glass ceramic, allowing the glass ceramic to be chemically strengthened, which is beneficial to ensuring the yield rate and production efficiency during production.

[0102] 2) The method for preparing the glass ceramic provided by the present application is simple and time-saving, and the temperature-time distribution of the heat treatment step and the composition of the precursor glass can control the proportion of the secondary crystal phase and the residual glass phase, forming various crystal phase compositions and grain sizes.

[0103] 3) The chemical strengthened glass ceramic provided by the present application has good hardness and other physical properties.

[0104] 4) The glass-ceramics and chemically strengthened glass-ceramics provided by the present application have excellent performance and can meet the application in electronic devices, transportation tools, buildings, and explosion-proof fields. BRIEF DESCRIPTION OF DRAWINGS

[0105] Figure 1 is a picture of the glass-ceramic sample in Example 1;

[0106] Figure 2 is an XRD curve of the glass-ceramic in Example 3;

[0107] Figure 3 is a transmittance curve of the glass-ceramic in Example 1;

[0108] Figure 4 is a transmittance curve of the glass-ceramic in Example 8;

[0109] Figure 5 is an SEM image of the glass-ceramic in Example 13. DETAILED DESCRIPTION

[0110] The content of the present application is further illustrated in detail by specific examples. The raw materials, reagents or devices used in the examples and comparative examples are commercially available or can be obtained by prior art methods unless otherwise specified. The test or test method is a conventional method in the art unless otherwise specified.

[0111] Example 1

[0112] This example provides a glass-ceramic, the components of which are shown in Table 1:

[0113] Table 1 Components of the glass-ceramic in Example 1

[0114] Component Content (mol%) Component Content (mol%) SiO2 49.2 ZnO 0 Al2O3 15.3 CaO 0 B2O3 1.3 MgO 0 Na2O 30 P2O5 2.4 Li2O 0 ZrO2 1.5 K2O 0 SrO 0.3

[0115] The glass-ceramic is prepared by the following steps:

[0116] S1, melt and refine each raw material at 1600℃ for 4h, then cast into a rectangular slab, and anneal the slab at 600℃ for 4h to obtain a precursor glass;

[0117] S2, heat the precursor glass from room temperature to 620℃ at a heating rate of 5℃ / min, keep for 8h, and cool to room temperature to obtain a glass-ceramic.

[0118] Figure 1 is a picture of the glass-ceramic sample in Example 1, which shows that the obtained glass-ceramic is colorless and transparent. Figure 1

[0119] Example 2

[0120] ​The embodiment provides a glass ceramic, and components of the glass ceramic are shown in Table 2.

[0121] Table 2 Glass ceramic components of Example 2

[0122] Component Content (mol%) Component Content (mol%) SiO2 52 ZnO 3.1 Al2O3 15 CaO 2.8 B2O3 0 MgO 0 Na2O 21.8 P2O5 3.3 Li2O 0 ZrO2 2 K2O 0 SrO 0

[0123] The glass ceramic is prepared through the following steps:

[0124] S1, after each preparation raw material is refined at 1600 DEG C for 4h, the rectangular slab is cast, the slab is annealed at 600 DEG C for 4h, and the precursor glass is obtained;

[0125] S2, the precursor glass is heated from room temperature to 600 DEG C at a heating rate of 5 DEG C / min, is kept for 2h, is heated to 650 DEG C at a heating rate of 5 DEG C / min, is kept for 1h, and is cooled to room temperature, and the glass ceramic is obtained.

[0126] Example 3

[0127] The embodiment provides a glass ceramic, and components of the glass ceramic are shown in Table 3:

[0128] Table 3 Glass ceramic components of Example 3

[0129] Component Content (mol%) Component Content (mol%) SiO2 53 ZnO 0 Al2O3 18 CaO 0 B2O3 0 MgO 0 Na2O 20 P2O5 2.7 Li2O 4.3 ZrO2 0 K2O 1.7 SrO 0.3

[0130] The glass ceramic is prepared through the following steps:

[0131] S1, after each preparation raw material is refined at 1600 DEG C for 4h, the rectangular slab is cast, the slab is annealed at 600 DEG C for 4h, and the precursor glass is obtained;

[0132] S2, the precursor glass is heated from room temperature to 600 DEG C at a heating rate of 5 DEG C / min, is kept for 2h, is heated to 650 DEG C at a heating rate of 5 DEG C / min, is kept for 1h, and is cooled to room temperature, and the glass ceramic is obtained.

[0133] Example 4

[0134] The embodiment provides a glass ceramic, and components of the glass ceramic are shown in Table 4:

[0135] Table 4 Glass ceramic components of Example 4

[0136] Component Content (mol%) Component Content (mol%) SiO2 47.4 ZnO 0.5 Al2O3 20.5 CaO 0 B2O3 0.3 MgO 0 Na2O 23.4 P2O5 5 Li2O 2.3 ZrO2 0 K2O 0 SrO 0.6

[0137] The glass ceramic is prepared through the following steps:

[0138] S1, after each preparation raw material is refined at 1600 DEG C for 4h, the rectangular slab is cast, the slab is annealed at 600 DEG C for 4h, and the precursor glass is obtained;

[0139] S2, heat the precursor glass from room temperature to 650°C at a heating rate of 5°C / min, keep for 1 h, then heat to 730°C at a heating rate of 5°C / min, keep for 1 h, cool to room temperature to obtain the glass-ceramic.

[0140] Example 5

[0141] This example provides a glass-ceramic, the components of which are shown in Table 5:

[0142] Table 5 Glass-ceramic components of Example 5

[0143] Component Content (mol%) Component Content (mol%) SiO2 58 ZnO 0 Al2O3 16.4 CaO 0 B2O3 0 MgO 0 Na2O 23.2 P2O5 2.1 Li2O 0 ZrO2 0.3 [K2O] 0 SrO 0

[0144] The glass-ceramic is prepared by the following steps:

[0145] S1, melt and refine each of the raw materials at 1600°C for 4 h, then cast into a rectangular slab, and anneal the slab at 600°C for 4 h to obtain a precursor glass;

[0146] S2, heat the precursor glass from room temperature to 800°C at a heating rate of 5°C / min, keep for 1.5 h, cool to room temperature to obtain the glass-ceramic.

[0147] Example 6

[0148] This example provides a glass-ceramic, the components of which are shown in Table 6:

[0149] Table 6 Glass-ceramic components of Example 6

[0150] Component Content (mol%) Component Content (mol%) SiO2 45.1 ZnO 0 Al2O3 15 CaO 3 B2O3 1.3 MgO 1.9 Na2O 21.4 P2O5 1.3 Li2O 10 Zr02 1 K2O 0 SrO 0

[0151] The glass-ceramic is prepared by the following steps:

[0152] S1, melt and refine each of the raw materials at 1600°C for 4 h, then cast into a rectangular slab, and anneal the slab at 600°C for 4 h to obtain a precursor glass;

[0153] S2, heat the precursor glass from room temperature to 620°C at a heating rate of 5°C / min, keep for 1 h, then heat to 740°C at a heating rate of 5°C / min, keep for 1 h, cool to room temperature to obtain the glass-ceramic.

[0154] Example 7

[0155] This example provides a glass-ceramic, the components of which are shown in Table 7:

[0156] Table 7 Glass-ceramic components of Example 7

[0157] Component Content (mol%) Component Content (mol%) SiO2 43 ZnO 2.9 Al2O3 23 CaO 0 B2O3 0 MgO 2.1 Na2O 26.3 P2O5 1.9 Li2O 0 ZrO2 0.4 K2O 0.4 SrO 0

[0158] The glass-ceramic is prepared by the following steps:

[0159] S1, each of the raw materials was melted at 1600℃ for 4h, and then cast into a rectangular slab, which was annealed at 600℃ for 4h to obtain a precursor glass;

[0160] S2, the precursor glass was heated from room temperature to 770℃ at a heating rate of 5℃ / min, kept for 2h, and then cooled to room temperature to obtain a glass ceramic.

[0161] Example 8

[0162] This example provides a glass ceramic, the components of which are shown in Table 8:

[0163] Table 8 Glass ceramic components of Example 8

[0164] Component Content (mol%) Component Content (mol%) SiO2 46.8 ZnO 0 Al2O3 17.2 CaO 0 B2O3 0 MgO 0 Na2O 22.6 P2O5 1 Li2O 0 ZrO2 2.4 K2O 10 SrO 0

[0165] The glass ceramic was prepared by the following steps:

[0166] S1, each of the raw materials was melted at 1600℃ for 4h, and then cast into a rectangular slab, which was annealed at 600℃ for 4h to obtain a precursor glass;

[0167] S2, the precursor glass was heated from room temperature to 630℃ at a heating rate of 5℃ / min, kept for 0.5h, then heated to 660℃ at a heating rate of 5℃ / min, kept for 1h, and then cooled to room temperature to obtain a glass ceramic.

[0168] Example 9

[0169] This example provides a glass ceramic, the components of which are shown in Table 9:

[0170] Table 9 Glass ceramic components of Example 9

[0171] Component Content (mol%) Component Content (mol%) SiO2 44.1 ZnO 0 Al2O3 15.5 CaO 0 B2O3 1.5 MgO 0 Na2O 27.6 P2O5 0.9 Li2O 2 ZrO2 3 K2O 4 SrO 1.4

[0172] The glass ceramic was prepared by the following steps:

[0173] S1, each of the raw materials was melted at 1600℃ for 4h, and then cast into a rectangular slab, which was annealed at 600℃ for 4h to obtain a precursor glass;

[0174] S2, the precursor glass was heated from room temperature to 700℃ at a heating rate of 5℃ / min, kept for 2h, and then cooled to room temperature to obtain a glass ceramic.

[0175] Example 10

[0176] This example provides a glass ceramic, the components of which are shown in Table 10:

[0177] Table 10 Glass ceramic components of Example 10

[0178] Component Content (mol%) Component Content (mol%) SiO2 43.5 ZnO 0 Al2O3 25 CaO 0 B2O3 0 MgO 0 Na2O 23.2 P2O5 3.2 Li2O 5.1 ZrO2 0 K2O 0 SrO 0

[0179] The glass-ceramic is prepared by the following steps:

[0180] S1, after each preparation raw material is refined at 1600 ℃ for 4 h, it is cast into a rectangular slab, the slab is annealed at 600 ℃ for 4 h, and a precursor glass is obtained;

[0181] S2, the precursor glass is heated from room temperature to 760 ℃ at a heating rate of 5 ℃ / min, isothermal for 2 h, is heated to 850 ℃ at a heating rate of 5 ℃ / min, isothermal for 4 h, and is cooled to room temperature, and a glass-ceramic is obtained.

[0182] Example 11

[0183] The example provides a glass-ceramic, and components of the glass-ceramic are shown in Table 11:

[0184] Table 11 Glass-ceramic components of Example 11

[0185] Component Content (mol%) Component Content (mol%) SiO2 47 ZnO 0 Al2O3 19 CaO 0 B2O3 0 MgO 0 Na2O 28 P2O5 2.5 Li2O 0 Zr02 1.5 K2O 2 SrO 0

[0186] The glass-ceramic is prepared by the following steps:

[0187] S1, after each preparation raw material is refined at 1600 ℃ for 4 h, it is cast into a rectangular slab, the slab is annealed at 600 ℃ for 4 h, and a precursor glass is obtained;

[0188] S2, the precursor glass is heated from room temperature to 760 ℃ at a heating rate of 5 ℃ / min, isothermal for 2 h, is heated to 850 ℃ at a heating rate of 5 ℃ / min, isothermal for 4 h, and is cooled to room temperature, and a glass-ceramic is obtained.

[0189] Example 12

[0190] The example provides a glass-ceramic, and components of the glass-ceramic are shown in Table 12:

[0191] Table 12 Glass-ceramic components of Example 12

[0192] Component Content (mol%) Component Content (mol%) SiO2 50 ZnO 0 Al2O3 16 CaO 0 B2O3 2.2 MgO 0 Na2O 27.1 P2O5 2.5 Li2O 1 Zr02 0.2 K2O 1 SrO 0

[0193] The glass-ceramic is prepared by the following steps:

[0194] S1, after each preparation raw material is refined at 1600 ℃ for 4 h, it is cast into a rectangular slab, the slab is annealed at 600 ℃ for 4 h, and a precursor glass is obtained;

[0195] S2, the precursor glass is heated from room temperature to 760 ℃ at a heating rate of 5 ℃ / min, isothermal for 2 h, is heated to 850 ℃ at a heating rate of 5 ℃ / min, isothermal for 4 h, and is cooled to room temperature, and a glass-ceramic is obtained.

[0196] Example 13

[0197] This example provides a glass-ceramic, the components of which are shown in Table 13:

[0198] Table 13 Glass-ceramic components of Example 13

[0199] Component Content (mol%) Component Content (mol%) SiO2 48 ZnO 0 Al2O3 20 CaO 0 B2O3 0 MgO 0 Na2O 30 P2O5 1.5 Li2O 0 ZrO2 0.5 K2O 0 SrO 0

[0200] The glass-ceramic is prepared by the following steps:

[0201] S1, after each preparation raw material is refined at 1600 ℃ for 4 h, cast into a rectangular slab, the slab is annealed at 600 ℃ for 4 h, to obtain a precursor glass;

[0202] S2, the precursor glass is heated from room temperature to 700 ℃ at a heating rate of 5 ℃ / min, incubated for 2 h, cooled to room temperature, to obtain a glass-ceramic.

[0203] Example 14

[0204] This example provides a glass-ceramic, the components of which are shown in Table 14:

[0205] Table 14 Glass-ceramic components of Example 14

[0206] Figure 2 Figure 2 Figure 3 Figure 4 SiO2 49 Figure 3 0 Al2O3 17.6 Figure 4 0 B2O3 0 Figure 5 0 Na2O 26.7 [P2O5] 3 Li2O 3.3 ZrO2 0.4 K2O 0 Figure 5 0

[0207] The glass-ceramic is prepared by the following steps:

[0208] S1, after each preparation raw material is refined at 1600 ℃ for 4 h, cast into a rectangular slab, the slab is annealed at 600 ℃ for 4 h, to obtain a precursor glass;

[0209] S2, the precursor glass is heated from room temperature to 720 ℃ at a heating rate of 5 ℃ / min, incubated for 0.5 h, cooled to room temperature, to obtain a glass-ceramic.

[0210] Example 15

[0211] This example provides a glass-ceramic, the components of which are shown in Table 15:

[0212] Table 15 Glass-ceramic components of Example 15

[0213] ​ ​ ​ ​ SiO2 53 ​ 0 Al2O3 16.4 ​ 0 B2O3 0 ​ 0 Na2O 22 P2O5 0.4 Li2O 4.2 ZrO2 1.6 K2O 2.4 ​ 0

[0214] The glass-ceramic is prepared by the following steps:

[0215] S1, after each preparation raw material is refined at 1600 ℃ for 4 h, cast into a rectangular slab, the slab is annealed at 600 ℃ for 4 h, to obtain a precursor glass;

[0216] S2, heat the precursor glass from room temperature to 650℃ at a heating rate of 5℃ / min, keep for 1h, then heat to 700℃ at a heating rate of 5℃ / min, keep for 8h, cool to room temperature, to obtain the glass-ceramic.

[0217] Comparative Example 1

[0218] This comparative example provides a glass-ceramic, the components of which are shown in Table 16:

[0219] Table 16 Glass-ceramic components of Comparative Example 1

[0220] ​ ​ ​ ​ SiO2 49 ​ 0 Al2O3 17.6 ​ 0 B2O3 0 ​ 0 Na2O 26.7 P2O5 3 Li2O 3.3 ZrO2 0.4 [K2O] 0 ​ 0

[0221] The glass-ceramic is prepared by the following steps:

[0222] S1, after melting and refining the raw materials at 1600℃ for 4h, cast into a rectangular slab, and anneal the slab at 600℃ for 4h to obtain a precursor glass;

[0223] S2, heat the precursor glass from room temperature to 740℃ at a heating rate of 5℃ / min, keep for 1h, cool to room temperature, to obtain the glass-ceramic.

[0224] Comparative Example 2

[0225] This comparative example provides a glass-ceramic, the components of which are shown in Table 17:

[0226] Table 17 Glass-ceramic components of Comparative Example 2

[0227] ​ ​ ​ ​ SiO2 53 ​ 0 Al2O3 16.4 ​ 0 B2O3 0 ​ 0 Na2O 22 P2O5 0.4 Li2O 4.2 ZrO2 1.6 K2O 2.4 ​ 0

[0228] The glass-ceramic is prepared by the following steps:

[0229] S1, after melting and refining the raw materials at 1600℃ for 4h, cast into a rectangular slab, and anneal the slab at 600℃ for 4h to obtain a precursor glass;

[0230] S2, heat the precursor glass from room temperature to 650℃ at a heating rate of 5℃ / min, keep for 1h, then heat to 700℃ at a heating rate of 5℃ / min, keep for 8h, cool to room temperature, to obtain the glass-ceramic.

[0231] Glass-ceramic characterization and performance testing

[0232] 1, analyze the crystal phase composition of the glass-ceramics in Examples 1-15 and Comparative Examples 1-2, and the results are shown in Table 18:

[0233] Table 18 Crystal phase composition of glass-ceramics in Examples 1-15 and Comparative Examples 1-2

[0234]

[0235]

[0236] Note: "LC" in the table represents low temperature triclinic nepheline, and "HC" represents high temperature triclinic nepheline.

[0237] Table 18 is the crystal phase composition of the glass-ceramics in Examples 1-15. As shown in Table 18, the crystal phase of the ceramic glass in Examples 1-15 includes only triclinic nepheline crystal phase, triclinic nepheline crystal phase and solid solution thereof (the solid solution includes at least one of NaAlSiO4-SiO2 solid solution, (Na, K)AlSiO4 solid solution, (Na, K)AlSiO4-SiO2 solid solution, R(A1, Si)O4 (wherein R = Na, K, Mg, Ca, Ba or a vacancy), (K, Na)SiO4, CaO, SiO2), triclinic nepheline crystal phase and nepheline crystal phase, triclinic nepheline crystal phase and phosphate phase, and various combinations of triclinic nepheline crystal phase, nepheline phase and phosphate phase. The glass-ceramics in Example 3 were subjected to X-ray diffraction analysis, ​ Table 20 is the XRD curve of the glass-ceramics in Example 3, ​ It can be seen from Table 20 that the glass-ceramics in Example 3 has only one crystal phase of triclinic nepheline, and the crystal peak is obvious and the crystallinity is high. That is, the glass-ceramics provided by the present application can only contain triclinic nepheline crystal phase, and the reduction of the phosphate phase is beneficial to the improvement of the chemical stability of the ceramic glass.

[0238] 2. The transmittance, haze, crystallinity, refractive index and crystal size of the glass-ceramics in Examples 1-15 and Comparative Examples 1-2 were determined, and the results are shown in Table 19.

[0239] Table 19 is the properties of the glass-ceramics in Examples 1-15 and Comparative Examples 1-2.

[0240]

[0241]

[0242] Table 19 is the properties of the glass-ceramics in Examples 1-15 and Comparative Examples 1-2. As shown in Table 19, the crystallinity of the ceramic glass in Examples 1-15 is greater than 30wt%; the crystal size is less than or equal to 89nm; the average transmittance of the glass-ceramics with a thickness of 0.7mm is greater than or equal to 68% in the wavelength range of 380-780nm, and the refractive index is 1.46-1.51. ​ Figure 2 is the transmittance curve of the glass-ceramics in Example 1, ​ Figure 4 is the transmittance curve of the glass-ceramics in Example 8, ​ and ​It can be seen that the glass ceramics of Example 1 and Example 8 have an average transmittance of 90% and 91% respectively. It can be seen that the ceramic glass provided by the application has high average transmittance and high crystallinity. ​ The SEM image of the glass ceramic in Example 13 is shown in FIG. 13. ​ It can be seen that the glass ceramic has a clear grid-like microstructure with clear regional separation, the diameter of the grid is about 200 nm, and the existence of the grid hinders ion migration. The crystal size in Example 13 is only about 58 nm, and the self-limiting crystallization effect is obvious.

[0243] 2. Chemical stability test of the glass ceramics in Examples 11-15 and Comparative Examples 1-2:

[0244] The test refers to the standard GB / T 32644-2016, and the test results are shown in Table 20. Specifically, the weight loss method is used for testing, and a 25mm×50mm×1mm sample is prepared. After ultrasonic cleaning with a neutral, organic solvent and water that does not corrode the sample, the sample is dried in an oven at 110°C for 30min, and then weighed on a balance and placed in a desiccator. During testing, the acid and base concentrations, corrosion temperature and time, etc. are used. After testing, the sample is cleaned with pure water and weighed on a balance. The sample mass is accurate to 0.01mg; the total surface area is calculated according to formula (I), and the mass change per unit area is calculated according to formula (II):

[0245] A = (L x W x 2) + [(L x W) x T x 2] (I);

[0246] Wherein, L: length of the sample to be tested, cm;

[0247] W: width of the sample to be tested, cm;

[0248] T: thickness of the sample to be tested, cm;

[0249] A: total surface area of the sample to be tested, cm 2 ;

[0250]

[0251] Wherein, W1: original mass of the sample, mg;

[0252] W2: mass of the sample after testing, mg;

[0253] A: total surface area of the sample to be tested, cm 2 ;

[0254] W A : change in mass per unit area, mg / cm 2 .

[0255] Chemical stability tests include:

[0256] (1) Chemical stability 1: mass loss of the glass-ceramics immersed in 10% HF solution at 20℃ for 20 min;

[0257] (2) Chemical stability 2: mass loss of the glass-ceramics immersed in 5% NaOH solution at 95℃ for 6 h;

[0258] (3) Chemical stability 3: mass loss of the glass-ceramics immersed in 5% HCl solution at 95℃ for 24 h;

[0259] (4) Chemical stability 4: mass loss of the glass-ceramics immersed in 10% NH4F-HF buffer solution at 20℃ for 20 min.

[0260] Table 20: Results of chemical stability tests of the glass-ceramics in Examples 11-15 and Comparative Examples 1-2

[0261]

[0262] Table 20: Results of chemical stability tests of the glass-ceramics in Examples 11-15 and Comparative Examples 1-2

[0263] 3. The glass-ceramics in Examples 11-15 were chemically strengthened by placing the glass-ceramics in a mixed salt bath containing NaNO3 and KNO3 for ion exchange, the ratio of the molten salt was 1:1, the ion exchange temperature was 450℃, and the total ion exchange time was 4 h, to obtain chemically strengthened glass-ceramics. The hardness of the glass-ceramics before and after chemical strengthening was tested, and the surface compressive stress (CS) and the depth of layer (DOL) of the glass-ceramics after chemical strengthening were tested, the hardness test conditions were: maximum load 1.961 N, peak holding time 15 s, and the test results are shown in Table 21:

[0264] Table 21: Properties of the glass-ceramics in Examples 11-15 before and after chemical strengthening

[0265]

[0266] Table 21 is the performance of the glass-ceramics before and after chemical strengthening in Examples 11-15, from Table 21, it can be seen that by ion exchange method for chemical strengthening, the large radius cation exchange glass-ceramics exist in small radius cation, compared with before strengthening, the Vickers hardness of the chemical strengthening glass-ceramics is increased, and the physical properties are improved. Potassium cation exchanges into the glass-ceramics, especially into the triakisite crystal, and the sodium cation or smaller cation is exchanged out of the glass-ceramics, which will make the unit cell of the triakisite crystal swell, and generate larger compressive stress and deeper compressive stress layer on the surface of the glass-ceramics. It can be seen that the glass-ceramics provided by the present application, which does not contain phosphate phase or has a low content of phosphate phase, is beneficial to the implementation of chemical strengthening treatment.

[0267] The glass-ceramics provided by the present application is a glass-ceramics with triakisite as the main crystal phase, and the mass percentage of the main crystal phase is greater than or equal to 30%, which can contain at least one secondary crystal phase of nepheline phase and phosphate phase, and the mass percentage of the secondary crystal phase is 0-49%. By reducing the content of the secondary crystal phase (especially the phosphate phase), the chemical stability of the glass-ceramics is improved, which is beneficial to the implementation of subsequent chemical strengthening and cleaning steps, and guarantees the yield rate and production efficiency in the production process. The crystallinity of the glass-ceramics can reach more than 80%, the crystal size is less than or equal to 89nm, and the average transmittance in the visible light band can reach more than 90%. The crystal phase composition is diverse and can be controlled according to the heat treatment step in the preparation method, and the heat treatment time is short. The physical properties of the chemically strengthened glass-ceramics are good, which can meet the application in the fields of electronic devices, transportation tools, buildings and explosion-proof.

Claims

1. A glass-ceramic, characterized in that, The glass-ceramic comprises the following components in terms of mole percentage: 44.1-53 mole % SiO2; 15-20 mole % Al2O3; 21.4-30 mole % Na2O; 0-10 mole % Li2O; 0-10 mole % K2O; 0.4-3.3 mole % P2O5; 0.5-3 mole % ZrO2; wherein the ratio of the mole percentage content of P2O5 to ZrO2 is 0.25-4; The glass-ceramic is composed of a main crystal phase, a secondary crystal phase and a residual glass phase, wherein the mass of the main crystal phase accounts for 60-85 % of the mass of the glass-ceramic; the mass of the secondary crystal phase accounts for 0-10 % of the mass of the glass-ceramic. The main crystal phase is at least one of triclinic nepheline phase and triclinic nepheline solid solution crystal phase. The secondary crystal phase is at least one of nepheline phase and phosphate phase; wherein the mass of the nepheline phase accounts for 0-10 % of the mass of the glass-ceramic; the mass of the phosphate phase accounts for 0-10 % of the mass of the glass-ceramic.

2. The glass-ceramic according to claim 1, characterized in that, The glass-ceramic further comprises the following components in terms of mole percentage: 0-10 mole % ZnO; 0-10 mole % CaO; 0-10 mole % MgO; 0-10 mole % SrO; 0-10 mole % B2O3; 0-10 mole % BaO.

3. The glass-ceramic according to claim 2, characterized in that, The glass-ceramic further comprises the following components in terms of mole percentage: 0-4 mole % ZnO; 0-3 mole % CaO; 0-3 mole % MgO; 0-2 mole % SrO; 0-3 mole % B2O3.

4. The glass-ceramic according to any one of claims 1 to 3, characterized in that, The glass-ceramic has a regionally separated grid-like microstructure; the diameter of the grid is 30-300 nm.

5. The glass-ceramic according to any one of claims 1 to 3, characterized in that, The average transmittance of the glass-ceramic is 65-93 % at a wavelength of 380-780 nm when the thickness of the glass-ceramic is 0.7 mm.

6. The glass-ceramic according to claim 1, characterized in that, The triclinic nepheline includes at least one of low-temperature triclinic nepheline and high-temperature triclinic nepheline. The solid solution includes at least one of NaAlSiO4-SiO2 solid solution, (Na, K)AlSiO4 solid solution and (Na, K)AlSiO4-SiO2 solid solution.

7. Process for the production of the glass-ceramic according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: S1, melting and mixing the components at 1400-1600 ℃ to obtain a precursor glass; S2, performing heat treatment on the precursor glass to obtain the glass-ceramic.

8. The preparation method according to claim 7, characterized in that, In the step S2, the heat treatment mode is selected from any one of one-step ceramming and two-step ceramming. The one-step ceramming is heating the precursor glass from room temperature to 620-800 ℃ at a heating rate of 1-10 ℃ / min, and holding for 0.5-8 h to obtain the glass-ceramic. The two-step ceramming is selected from any one of the following: (1) heating the precursor glass from room temperature to 600-650 ℃ at a heating rate of 1-10 ℃ / min, holding for 0.5-2 h, then heating to 650-750 ℃ at a heating rate of 1-10 ℃ / min, holding for 1-8 h to obtain the glass-ceramic; (2) heating the precursor glass from room temperature to 700-800℃ at a heating rate of 1-10℃ / min, holding for 1-2h, and then heating to 800-850℃ at a heating rate of 1-10℃ / min, holding for 2-4h to obtain the glass ceramic.

9. A chemically strengthened glass-ceramic, characterized in that, The glass ceramic according to any one of claims 1-6.

10. The chemically strengthened glass ceramic according to claim 9, characterized in that, The surface compressive stress of the chemically strengthened glass ceramic can be 200-3000MPa, and the depth of the surface compressive stress can be 10-160μm.

11. The method of making a chemically strengthened glass-ceramic according to claim 9 or 10, characterized in that, The method comprises the following steps: The glass ceramic is placed in a salt bath containing NaNO3 and / or KNO3 for single or multiple ion exchange to obtain the chemically strengthened glass ceramic.

12. The method of making a chemically strengthened glass-ceramic according to claim 11, characterized in that, The ion exchange temperature is 400-600℃. The ion exchange time is 1-12h.

13. Use of the glass ceramic according to any one of claims 1-6, or the chemically strengthened glass ceramic according to claim 9 or 10 in the fields of electronic devices, transportation, building, and explosion protection.

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