CN113683309A

CN113683309A - Glass-ceramic and its preparation method and application

Info

Publication number: CN113683309A
Application number: CN202110983971.2A
Authority: CN
Inventors: 平文亮; 蒋江; 刘红刚; 王明忠; 肖子凡; 王琰; 康庆伟; 赵北玉
Original assignee: CSG Holding Co Ltd; Xianning CSG Photoelectric Glass Co Ltd; Qingyuan CSG New Energy Saving Materials Co Ltd
Current assignee: CSG Holding Co Ltd; Xianning CSG Photoelectric Glass Co Ltd; Qingyuan CSG New Energy Saving Materials Co Ltd
Priority date: 2021-08-25
Filing date: 2021-08-25
Publication date: 2021-11-23
Anticipated expiration: 2041-08-25
Also published as: CN113683309B; WO2023024164A1

Abstract

The present invention provides a glass-ceramic, the glass-ceramic comprises a glass substrate and a composite glass-ceramic layer coated on the surface of the glass substrate; wherein, the composite glass-ceramic layer comprises a hexagonal β-glass Spodumene, tetragonal β-spodumene and other glasses. The surface of glass-ceramic has very high Vickers hardness and compressive stress, thereby significantly improving the surface hardness and drop resistance of glass, while being easy to process and low cost.

Description

Microcrystalline glass and preparation method and application thereof

Technical Field

The invention relates to the field of glass, in particular to microcrystalline glass and a preparation method and application thereof.

Background

With the rapid development of the smart technology industry and the popularization of digital products in recent years, smart phones, tablet computers and the like equipped with touch screens have become indispensable parts in life, and the protective material of the cover plate at the outermost layer of the touch screen becomes a high-strength armor for protecting the touch screen. The cover plate of the traditional touch screen is mainly made of high-alumina glass, is mainly applied to the outmost layer of the touch screen and has the functions of impact resistance, scratch resistance, oil stain resistance, fingerprint resistance, light transmittance enhancement and the like. Currently, high-alumina glass is widely applied to various electronic consumer products with touch control function and display function.

In the traditional technology, high-aluminosilicate glass and lithium-aluminosilicate glass are developed by means of increasing the content of alumina, adding lithium oxide and the like, and the performances of impact resistance, scratch resistance, falling resistance, sweat corrosion resistance and the like of the glass are improved by one-time or multiple-time chemical strengthening. But is largely limited to rough ground due to the inherent brittleness and lower crack propagation resistance of glass materialsIs generally less than 1.4 meters, especially multiple times drop resistance; and the Vickers hardness of the alloy is usually 550Kgf/mm²～680Kgf/mm²Hardly exceeds 700Kgf/mm²I.e., less scratch resistance.

Also, a high strength glass-ceramic having a lithium feldspar and lithium silicate structure, which is an integrally crystallized glass-ceramic having high mechanical strength and fracture resistance, is prepared by conventional techniques. However, it contains more than 10 wt% of Li₂O component due to Li₂The O reserve is limited, and the cost is high throughout the year, so that the cost of the glass ceramics is very high and is more than 10 times higher than that of the similar lithium-aluminum-silicon glass; and because of the integral crystallization, the glass is similar to ceramics in the post-processing process of the glass, and the processing difficulty and the cost are far higher than those of the glass substrate.

Disclosure of Invention

Based on the structure, the invention provides the microcrystalline glass, wherein a composite microcrystalline glass layer containing a beta-spodumene crystal phase is formed on the surface of a glass substrate, and the surface of the microcrystalline glass has very high Vickers hardness and compressive stress, so that the surface hardness and the anti-falling performance of the glass are obviously improved, and the microcrystalline glass is easy to process and low in cost.

The invention is realized by the following technical scheme.

The microcrystalline glass comprises a glass substrate and a composite microcrystalline glass layer coated on the surface of the glass substrate;

wherein the composite microcrystalline glass layer comprises beta-spodumene in a hexagonal crystal form, beta-spodumene in a tetragonal crystal form and other glass.

In one embodiment, the composite glass-ceramic layer comprises, by mass, 19.2% to 88.5% of the hexagonal form of β -spodumene, 3% to 75.8% of the tetragonal form of β -spodumene, and 5% to 14.8% of the other glass.

In one embodiment, the other glass comprises SiO₂、Al₂O₃、Li₂O、Na₂O and other oxides; the other oxide is selected from K₂O、MgO、ZrO₂、B₂O₃、P₂O₅And ZnO; and/or

The glass substrate comprises SiO₂、Al₂O₃、Li₂O、Na₂O and other oxides; the other oxide is selected from K₂O、MgO、ZrO₂、B₂O₃、P₂O₅And ZnO.

In one embodiment, the thickness of the composite microcrystalline glass layer is 2-90 μm.

The invention also provides a preparation method of the microcrystalline glass, which comprises the following steps:

preparing a glass prefabricated part, and performing primary crystallization and secondary crystallization on the glass prefabricated part to prepare the composite microcrystalline glass layer;

wherein the temperature of the first crystallization is 630-700 ℃, and the time of the first crystallization is 2-10 h;

and after the first crystallization is finished, heating, and carrying out second crystallization, wherein the temperature of the second crystallization is 780-830 ℃, and the time of the second crystallization is 0.5-4 h.

In one embodiment, the raw materials of the glass prefabricated member are mixed, melted for 7 to 9 hours at 1500 to 1650 ℃, then cooled to 1300 to 1500 ℃, kept warm for 1.5 to 2.5 hours, molded, prepared into a glass block, annealed after the glass block is hardened, and cooled;

wherein the raw material of the glass preform comprises SiO₂、Al₂O₃、Li₂O、Na₂O and other oxides; the other oxide is selected from K₂O、MgO、ZrO₂、B₂O₃、P₂O₅And ZnO.

In one embodiment, the raw material of the glass preform comprises 50 to 68 mass percent of SiO₂、18％～29.5％Al₂O₃、2％～6.5％Li₂O、3％～10％Na₂O and 0.1-15% of other oxides.

In one embodiment, the temperature of the first crystallization is 660-700 ℃, and the time of the first crystallization is 2-10 h.

In one embodiment, the temperature of the second crystallization is 810-830 ℃, and the time of the second crystallization is 1-4 h.

In one embodiment, the temperature rise rate is 2-10 deg.C/min.

The invention also provides application of the microcrystalline glass in protective glass, special glass and architectural glass of electronic devices.

Compared with the prior art, the microcrystalline glass has the following beneficial effects:

the microcrystalline glass comprises a glass substrate and a composite microcrystalline glass layer which is formed on the surface of the glass substrate and contains a beta-spodumene crystal phase and other glass, wherein the beta-spodumene comprises a hexagonal crystal form and a tetragonal crystal form. The composite microcrystalline glass layer can form a uniform and compact compressive stress layer on the surface of glass, so that the composite microcrystalline glass layer has very high Vickers hardness and compressive stress, and the surface hardness and the drop resistance of the whole glass are obviously improved.

In addition, the microcrystalline glass provided by the invention keeps the advantage that the glass substrate is easy to process, and is low in cost and easy to industrialize.

Drawings

FIG. 1 is an XRD pattern of a sample provided by the present invention; wherein: 1 represents an XRD pattern of the microcrystalline glass preform composite microcrystalline glass layer provided in example 6, 2 represents an XRD pattern of the microcrystalline glass preform composite microcrystalline glass layer provided in example 12, 3 represents an XRD pattern of the microcrystalline glass preform composite microcrystalline glass layer provided in example 1, 4 represents an XRD pattern of a hexagonal β -spodumene sample, and 5 represents an XRD pattern of a tetragonal β -spodumene sample;

FIG. 2 is a sectional scanning electron microscope image of a sample provided in example 2 of the present invention.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the accompanying examples. The preferred embodiments of the present invention are given in the examples. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The invention provides microcrystalline glass, which comprises a glass substrate and a composite microcrystalline glass layer coated on the surface of the glass substrate;

wherein the composite microcrystalline glass layer comprises hexagonal beta-spodumene, tetragonal beta-spodumene and other glass.

In a specific example, the composite microcrystalline glass layer comprises 19.2-88.5% of beta-spodumene in a hexagonal crystal form, 3-75.8% of beta-spodumene in a tetragonal crystal form and 5-14.8% of other glass in percentage by mass.

In the glass-ceramic, the component species of the other glass are consistent with the composition of the glass matrix.

In one particular example, the other glass comprises SiO₂、Al₂O₃、Li₂O、Na₂O and other oxides; the other oxide is selected from K₂O、MgO、ZrO₂、B₂O₃、P₂O₅And ZnO.

In one particular example, the glass substrate comprises SiO₂、Al₂O₃、Li₂O、Na₂O and other oxides; the other oxide is selected from K₂O、MgO、ZrO₂、B₂O₃、P₂O₅And in ZnOThree are fewer.

In a specific example, the composite microcrystalline glass layer has a thickness of 2 μm to 90 μm. It is understood that in the present invention, the thickness of the composite microcrystalline glass layer includes, but is not limited to, 2 μm, 3 μm, 4 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm.

preparing a glass prefabricated part, and performing primary crystallization and secondary crystallization on the glass prefabricated part to prepare a composite microcrystalline glass layer;

After the glass prefabricated member is subjected to a specific twice crystallization process, a layer, namely a composite microcrystalline glass layer, is uniformly separated out on the surface layer, an intermediate glass layer is remained, and the composite microcrystalline glass layer and the glass layer form microcrystalline glass together.

In one particular example, the preparation of the glass preform comprises the steps of: mixing the raw materials of the glass prefabricated member, melting for 7-9 h at 1500-1650 ℃, then cooling to 1300-1500 ℃, preserving heat for 1.5-2.5 h, forming, preparing a glass block, annealing after the glass block is hardened, and cooling;

It is understood that in the present invention, SiO is contained as long as it is₂、Al₂O₃、Li₂O、Na₂O and other oxide species may be used as starting materials, including but not limited to: quartz sand, aluminium hydroxide, lithium carbonate/lithium glowStone, sodium carbonate, sodium nitrate.

In a specific example, the raw material of the glass preform includes 50% to 68% SiO in mass percentage₂、18％～29.5％Al₂O₃、2％～6.5％Li₂O、3％～10％Na₂O and 0.1-15% of other oxides.

Preferably, the temperature of the first crystallization is 660 to 700 ℃.

Preferably, the time for the first crystallization is 2h to 10 h.

Preferably, the temperature of the second crystallization is 810 ℃ to 830 ℃.

Preferably, the time for the second crystallization is 1h to 4 h.

In a specific example, the rate of temperature rise is 2 ℃/min to 10 ℃/min. As can be appreciated, in the present invention, the rate of temperature rise includes, but is not limited to, 2 deg.C/min, 3 deg.C/min, 4 deg.C/min, 5 deg.C/min, 6 deg.C/min, 7 deg.C/min, 8 deg.C/min, 9 deg.C/min, 10 deg.C/min.

The invention also provides application of the microcrystalline glass in protective glass, special glass and architectural glass of electronic devices. It is understood that electronic devices include, but are not limited to, smart display devices, mobile devices, and the like.

It is understood that in the present invention, the above-mentioned glass ceramics can be obtained in the conventional flat glass manufacturing process, and the manufacturing process is not limited to the float forming process, the overflow down-draw process, the up-draw process, the flat-draw process, the rolling process, etc.

The following describes the glass ceramics and the method for producing the same in further detail with reference to specific examples. The starting materials used in the following examples are all commercially available products unless otherwise specified.

Example 1

The embodiment provides microcrystalline glass and a preparation method thereof, and the microcrystalline glass comprises the following specific steps:

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

58% SiO₂22% of Al₂O₃0.5% of K₂O, 1.5% of MgO and 10% of Na₂O, 4% Li₂O, 2% ZrO ₂1% of B₂O₃1% of ZnO;

after fully and uniformly mixing, melting for 8h at 1650 ℃ with a platinum crucible, stirring with a platinum stirring paddle, after the stirring paddle is drawn out, cooling to 1300-1500 ℃, preserving heat for 2h, homogenizing, casting onto an iron mold to form a glass block with the size of about 80 x 160mm, preheating to 450 ℃ before casting, immediately transferring the glass block to an annealing furnace for annealing after hardening, preserving heat for 2h, then cooling for 6 h to 140 ℃, naturally cooling, and taking out for later use.

Step two: preparation of glass ceramics

Crystallizing the glass preform according to the following crystallization process, wherein TT1 refers to the time and temperature of the first crystallization process, and TT2 refers to the time and temperature of the second crystallization process:

TT1：645℃，4h；

TT2：800℃，1h；

the heating rate was 10 ℃/min.

Example 2

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

58% SiO₂20% of Al₂O₃4% of K₂O, 4% MgO, 4.5% Na₂O, 5% of Li₂O, 4.5% ZrO₂；

Step two: preparation of glass ceramics

TT1：630℃，6h；

TT2：810℃，1h；

the heating rate was 5 ℃/min.

Example 3

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

56% SiO₂26% of Al₂O₃1% of K₂O, 1.5% of MgO and 2% of Na₂O, 7% of Li₂O, 1% ZrO ₂1% of B₂O₃0.5% of P₂O₅4% of ZnO;

Step two: preparation of glass ceramics

TT1：680℃，4h；

TT2：810℃，1h；

the heating rate was 2 ℃/min.

Example 4

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

61% SiO₂23% of Al₂O₃1.3% of K₂O, 1.5% of MgO and 4.2% of Na₂O, 3.5% of Li₂O, 1% ZrO ₂3% of B₂O₃0.5% of P₂O₅1% of ZnO;

Step two: preparation of glass ceramics

TT1：650℃，10h；

TT2：800℃，2h；

the heating rate was 10 ℃/min.

Example 5

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

68% SiO₂18% of Al₂O₃1% of K₂O, 1.5% of MgO and 4% of Na₂O, 4.5% of Li₂O, 1% ZrO₂1.5% of B₂O₃0.5% of P₂O₅；

Step two: preparation of glass ceramics

TT1：660℃，4h；

TT2：810℃，1h；

the heating rate was 5 ℃/min.

Example 6

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

59% SiO₂25% of Al₂O₃1% of K₂O, 1.5% of MgO and 3% of Na₂O, 2% Li₂O, 0.5% ZrO ₂3% of B₂O₃5% of P₂O₅；

Step two: preparation of glass ceramics

TT1：675℃，4h；

TT2：795℃，1h；

the heating rate was 10 ℃/min.

Example 7

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

58% SiO₂22% of Al₂O₃1% of K₂O, 1% MgO, 3% Na₂O, 6% Li₂O, 2% ZrO ₂3% of B₂O₃2% of P₂O₅2% of ZnO;

Step two: preparation of glass ceramics

TT1：690℃，4h；

TT2：820℃，1h；

the heating rate was 2 ℃/min.

Example 8

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

50% SiO₂29.5% of Al₂O₃1.4% of K₂O, 0.5% of MgO and 7% of Na₂O, 4% Li₂O, 1% ZrO ₂5% of B₂O₃1.6% of P₂O₅；

Step two: preparation of glass ceramics

TT1：680℃，6h；

TT2：810℃，1h；

the heating rate was 5 ℃/min.

Example 9

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

57% SiO₂23% of Al₂O₃1.5% of K₂O, 3.5% of MgO and 4.5% of Na₂O, 4% Li₂O, 4% ZrO₂0.5% of B₂O₃1% of P₂O₅1% of ZnO;

Step two: preparation of glass ceramics

TT1：660℃，4h；

TT2：810℃，0.5h；

the heating rate was 5 ℃/min.

Example 10

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

56% SiO₂26% of Al₂O₃1.4% of K₂O, 3.5% of MgO and 5% of Na₂O, 4.5% of Li₂O, 3.6% ZrO₂；

Step two: preparation of glass ceramics

TT1：650℃，6h；

TT2：790℃，2h；

the heating rate was 2 ℃/min.

Example 11

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

56% SiO₂25% of Al₂O₃1.5% of K₂O, 1% of MgO and 7% of Na₂O, 5% of Li₂O, 2% ZrO ₂1% of B₂O₃1.5% of P₂O₅；

Step two: preparation of glass ceramics

TT1：645℃，4h；

TT2：810℃，1h；

the heating rate was 5 ℃/min.

Example 12

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

55% SiO₂25% of Al₂O₃1% of K₂O, 2% of MgO and 4% of Na₂O, 6.5% Li₂O, 1% ZrO ₂3% of B₂O₃0.5% of P₂O₅2% of ZnO;

Step two: preparation of glass ceramics

TT1：690℃，4h；

TT2：820℃，1h；

the heating rate was 10 ℃/min.

Example 13

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

60.5% SiO₂24% of Al₂O₃1% of K₂O, 1.5% of MgO and 4% of Na₂O, 4.5% of Li₂O, 1% ZrO ₂3% of B₂O₃0.5% of P₂O₅；

Step two: preparation of glass ceramics

TT1：700℃，2h；

TT2：820℃，1h；

the heating rate was 5 ℃/min.

Example 14

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

63% SiO₂22% of Al₂O₃1% of K₂O, 1% MgO, 4.5% Na₂O, 5% of Li₂O, 1% ZrO ₂2% of B₂O₃0.5% of P₂O₅；

Step two: preparation of glass ceramics

TT1：650℃，4h；

TT2：810℃，1.5h；

the heating rate was 10 ℃/min.

Example 15

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

55% SiO₂25% of Al₂O₃9% of Na₂O, 3% of Li₂O, 3% of B₂O₃4% of P₂O₅1% of ZnO;

Step two: preparation of glass ceramics

TT1：650℃，10h；

TT2：820℃，2h；

the heating rate was 2 ℃/min.

Example 16

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

53% SiO₂28% of Al₂O₃1.5% of MgO and 7% of Na₂O, 3% of Li₂O, 3.5% ZrO ₂1% of B₂O₃3% of P₂O₅；

Step two: preparation of glass ceramics

TT1：660℃，6h；

TT2：810℃，4h；

the heating rate was 10 ℃/min.

Example 17

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

57% SiO₂25% of Al₂O₃1.5% of K₂O, 3.5% of MgO and 4.5% of Na₂O, 4% Li₂O, 3% ZrO₂0.5% of B₂O₃1% of ZnO;

Step two: preparation of glass ceramics

TT1：630℃，8h；

TT2：810℃，1h；

the heating rate was 10 ℃/min.

Example 18

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

58.5% SiO₂25% of Al₂O₃1.5% of K₂O, 3.5% of MgO and 4.5% of Na₂O, 4% Li₂O, 2.5% ZrO₂0.5% of B₂O₃；

Step two: preparation of glass ceramics

TT1：645℃，10h；

TT2：780℃，4h；

the heating rate was 5 ℃/min.

Example 19

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

61% SiO₂24% of Al₂O₃1% of K₂O, 1% MgO, 4% Na₂O, 5% of Li₂O, 2% ZrO ₂2% of B₂O₃；

Step two: preparation of glass ceramics

TT1：645℃，4h；

TT2：810℃，1h；

the heating rate was 2 ℃/min.

Example 20

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

62% SiO₂24% of Al₂O₃0.5% of K₂O, 0.5% MgO, 4.5% Na₂O, 5% of Li₂O, 1% ZrO ₂2% of B₂O₃0.5% of P₂O₅；

Step two: preparation of glass ceramics

TT1：690℃，4h；

TT2：820℃，0.5h；

the heating rate was 10 ℃/min.

Example 21

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

62% SiO₂23% of Al₂O₃0.5% of K₂O, 0.5% of MgO and 5% of Na₂O, 5% of Li₂O, 2% ZrO₂1.5% of B₂O₃0.5% of P₂O₅；

Step two: preparation of glass ceramics

TT1：645℃，4h；

TT2：810℃，1h；

the heating rate was 2 ℃/min.

Example 22

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

62% SiO₂23% of Al₂O₃1% of K₂O, 0.5% of MgO and 5% of Na₂O, 5% of Li₂O, 1.5% ZrO₂1.5% of B₂O₃0.5% of P₂O₅；

Step two: preparation of glass ceramics

TT1：645℃，4h；

TT2：810℃，1h；

the heating rate was 5 ℃/min.

Example 23

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

56% SiO₂23% of Al₂O₃4% of K₂O, 7% of Na₂O, 3% of Li₂O, 2% ZrO ₂3% of P₂O₅2% of ZnO;

Step two: preparation of glass ceramics

TT1：650℃，10h；

TT2：810℃，1.5h；

the heating rate was 10 ℃/min.

Example 24

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

55% SiO₂25% of Al₂O₃3% of K₂O, 7% of Na₂O, 4% Li₂O, 2% of B₂O₃4% of P₂O₅；

Step two: preparation of glass ceramics

TT1：660℃，10h；

TT2：830℃，1h；

the heating rate was 5 ℃/min.

Example 25

the method comprises the following steps: production of glass preform

Mixing the following raw materials in percentage by mass:

56% SiO₂25% of Al₂O₃3% of MgO and 7% of Na₂O, 3% of Li₂O, 3.5% ZrO ₂1% of B₂O₃1.5% of P₂O₅；

Step two: preparation of glass ceramics

TT1：700℃，2h；

TT2：820℃，1h；

the heating rate was 10 ℃/min.

Effect test

The glass preform obtained in the first step of examples 1 to 25 was cut into a 70 × 140 × 0.7mm glass sheet by a line cutter STX-1203 of shenyan crystal, polished by a HD-640-5L double-side grinding polisher of shenzhen heider, CNC-edged, and tested for surface vickers hardness using a FALCON400 hardness tester from netherlands rank.

The microcrystalline glasses obtained in the second step of examples 1 to 25 were tested for Vickers hardness by a FALCON400 hardness tester of anethod, the United states PerkinElmer Lamba 950 ultraviolet-visible spectrophotometer, which tests the transmittance in the wavelength range of 400-.

The microcrystalline glass obtained in the second step of examples 1 to 25 was cut, the cross section was polished and ground, then etched for 20 seconds with 5 vol% HF solution, and the surface crystal phase structure and the crystal phase layer thickness were tested by the seemer fly FEI Apreo scanning electron microscope.

The glass ceramics obtained in the second step of the above examples 1 to 25 are cut into 20 × 20mm, the crystal phase type of the composite glass ceramics layer is tested by Bruker D8 advance of Bruker, and the proportions of different crystal phases and amorphous phases in the composite glass ceramics layer are calculated by simulation of TOPAS software.

The composition, crystallite process parameters and effect test results for examples 1-8 are shown in table 1.

TABLE 1

The composition, crystallite process parameters and effect test results for examples 9-16 are shown in table 2.

TABLE 2

The composition, crystallite processing parameters and effect test results for examples 17-25 are shown in table 3.

TABLE 3

Wherein, the XRD patterns of example 1, example 6 and example 12 are respectively shown in fig. 1, it can be seen that the less beta-spodumene (tetragonal form) in the crystal phase layer, especially less than 10.4%, the transmittance of the 0.7mm sample is higher than 90%, and the sample is transparent; beta-spodumene (tetragonal form) is increasing, especially above 40%, and the 0.7mm sample has a transmittance of less than 72% and an opaque white appearance.

Fig. 2 is a typical sectional scanning electron microscope image of a sample in example 12, which shows that after the above glass composition is subjected to a proper crystallization process, a crystal phase layer with a thickness of 2 μm to 90 μm can be uniformly precipitated on a surface layer, and the crystal phase layer and the intermediate glass layer are combined together to form a surface-crystallized glass-ceramic composition, and a uniform and dense compressive stress layer is formed on the surface of the glass through volume change caused by surface crystallization, so that the surface hardness and the sandpaper drop resistance of the glass can be significantly improved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, so as to understand the technical solutions of the present invention specifically and in detail, but not to be understood as the limitation of the protection scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. It should be understood that the technical solutions provided by the present invention, which are obtained by logical analysis, reasoning or limited experiments, are within the scope of the appended claims. Therefore, the protection scope of the present invention should be subject to the content of the appended claims, and the description and the drawings can be used for explaining the content of the claims.

Claims

1. A glass-ceramic, characterized in that the glass-ceramic comprises a glass substrate and a composite glass-ceramic layer coated on the surface of the glass substrate;

Wherein, the composite glass-ceramic layer includes hexagonal β-spodumene, tetragonal β-spodumene and other glasses.

2 . The glass-ceramic according to claim 1 , wherein, in mass percentage, the composite glass-ceramic layer comprises 19.2%-88.5% of the hexagonal β-spodumene, 3% ~75.8% of the tetragonal β-spodumene and 5% to 14.8% of the other glasses.

3 . The glass-ceramic according to claim 1 , wherein the other glass comprises SiO ₂ , Al ₂ O ₃ , Li ₂ O, Na ₂ O and other oxides; the other oxides are selected from K At least three of ₂ O, MgO, ZrO ₂ , B ₂ O ₃ , P ₂ O ₅ and ZnO; and/or

The glass matrix includes SiO ₂ , Al ₂ O ₃ , Li ₂ O, Na ₂ O and other oxides; the other oxides are selected from K ₂ O, MgO, ZrO ₂ , B ₂ O ₃ , P ₂ O ₅ with at least three of ZnO.

4 . The glass-ceramic according to claim 1 , wherein the composite glass-ceramic layer has a thickness of 2 μm˜90 μm. 5 .

5. A method for preparing glass-ceramic according to any one of claims 1 to 4, characterized in that, comprising the steps of:

preparing a glass preform, and performing the first crystallization and the second crystallization on the glass preform to prepare the composite glass-ceramic layer;

Wherein, the temperature of the first crystallization is 630℃～700℃, and the time of the first crystallization is 2h～10h;

After the first crystallization is completed, the temperature is raised, and the second crystallization is carried out.

6 . The preparation method of glass-ceramic according to claim 5 , wherein the preparation of the glass preform comprises the following steps: mixing the raw materials of the glass preform, and melting at 1500° C. to 1650° C. for 7 hours to 9 hours. 7 . , then cooled to 1300℃～1500℃, kept for 1.5h～2.5h, formed, and prepared glass blocks, annealed and cooled after the glass blocks were hardened;

Wherein, the raw materials of the glass preforms include SiO ₂ , Al ₂ O ₃ , Li ₂ O, Na ₂ O and other oxides; the other oxides are selected from K ₂ O, MgO, ZrO ₂ , B ₂ O ₃ At least three of , P ₂ O ₅ and ZnO.

7 . The method for preparing glass-ceramic according to claim 6 , wherein, in terms of mass percentage, the raw materials of the glass preforms comprise 50%-68% SiO ₂ , 18%-29.5% Al ₂ O ₃ . , 2% to 6.5% Li ₂ O, 3% to 10% Na ₂ O, and 0.1% to 15% of other oxides.

8 . The method for preparing glass-ceramic according to claim 5 , wherein the temperature of the first crystallization is 660° C. to 700° C., and the time of the first crystallization is 2 h to 10 h. 9 . .

9 . The method for preparing glass-ceramic according to claim 5 , wherein the temperature of the second crystallization is 810° C. to 830° C., and the time of the second crystallization is 1 h to 4 h. 10 . .

10 . The method for preparing glass-ceramic according to claim 5 , wherein the heating rate is 2° C./min to 10° C./min. 11 .

11. Application of the glass-ceramic according to any one of claims 1 to 4 in protective glass, special glass and architectural glass of electronic devices.