High-strength fluorophlogopite microcrystalline glass ceramic and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of mica microcrystalline glass ceramics, and particularly relates to a high-strength fluorophlogopite microcrystalline glass ceramic and a preparation method thereof.The preparation method comprises the following steps that fluorophlogopite powder, glass powder and ceramic powder are evenly mixed, and mixed powder is prepared; dissolving a dispersing agent in deionized water to prepare a solution; putting ceramic balls, the mixed powder and the solution into a ball milling tank to prepare premixed slurry; adding a binder into the pre-mixed slurry to prepare mixed slurry, and carrying out vacuum defoaming on the slurry to prepare microcrystalline glass ceramic slurry; injecting the prepared microcrystalline glass ceramic slurry into a mold to prepare a fluorophlogopite microcrystalline glass ceramic green body; and calcining to obtain the fluorophlogopite microcrystalline glass ceramic. The fluorophlogopite microcrystalline glass ceramic green body can be prepared by reasonably controlling the proportion of the dispersing agent, the binder, the deionized water and the like through ball milling, defoaming, pouring, drying and sintering, the process is simple, and forming is easy.

Description

Technical Field

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

[0002] Fluorophlogopite glass-ceramics not only have the advantages of high mechanical properties, good insulation, good chemical stability, low dielectric constant, small thermal expansion coefficient, good heat resistance, etc., but also have excellent workability, and are widely used in the fields of electronics, aerospace, machinery, chemical engineering, etc.

[0003] Fluorophlogopite belongs to layered silicate minerals. The layers in its structure are connected by van der Waals forces, with weak bonding and easy cleavage. It is very difficult to sinter fluorophlogopite ceramics densely. And using the traditional glass-ceramics preparation process, due to the poor thermal conductivity of the glass body, too thick or too large samples are likely to cause uneven annealing and crystallization processes, resulting in a decline in material properties or causing sample fragmentation. Therefore, it is very difficult to prepare large-size glass-ceramic materials using the traditional glass process, which limits the large-scale application of fluorophlogopite glass-ceramics. The sintering method is to make a green body by ceramic forming process and then obtain glass-ceramics after sintering. Currently, dry pressing is usually used to prepare glass-ceramics. Although this method has the advantages of convenient operation, short cycle, and high efficiency, the cost of the mold is high and the wear is large, and it is very difficult to prepare large-size green bodies. The gel-casting method has a simple process and can prepare large-size complex products, but currently the amount of organic matter used is large, which not only easily pollutes the environment, but also the volatilization of organic matter will have a greater impact on the properties of ceramics.

[0004] The preparation of existing fluorophlogopite glass-ceramics has the disadvantages of high cost, high energy consumption, and difficulty in preparing large-size products, which greatly limits the large-scale production and application of fluorophlogopite glass-ceramics. Therefore, how to prepare fluorophlogopite glass-ceramics at low cost is an urgent problem to be solved in this field. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above problems existing in the traditional technology, and provide a high-strength fluorophlogopite glass-ceramics and a preparation method thereof. The fluorophlogopite glass-ceramics prepared by this method have high strength, and this method is easy to prepare large-size products, with low cost and great application prospects.

[0006] To achieve the above technical purposes and reach the above technical effects, the present invention is realized through the following technical solutions:

[0007] A preparation method of a high-strength fluorophlogopite glass-ceramics comprises the following steps:

[0008] 1) Mix 30 - 80 wt% of fluorophlogopite powder, 20 - 70 wt% of glass powder, and 0 - 25 wt% of ceramic powder evenly to obtain a mixed powder;

[0009] 2) Dissolve a dispersant in deionized water at a mass ratio of dispersant:deionized water of (0.009 - 0.09):1, and stir rapidly for 2 - 5 min to obtain a solution;

[0010] 3) Place ceramic balls, the mixed powder prepared in step 1), and the solution prepared in step 2) in a ball mill tank at a mass ratio of ceramic balls:mixed powder:deionized water of (6 - 9):(3 - 4.5):1, and ball mill for 15 - 180 min to obtain a pre - mixed slurry;

[0011] 4) Add a binder to the pre - mixed slurry at a mass ratio of binder:deionized water of (0.006 - 0.15):1, ball mill for 30 - 120 min to obtain a mixed slurry, and degas the slurry under vacuum for 15 - 60 min to obtain a glass - ceramic slurry;

[0012] 5) Pour the glass - ceramic slurry prepared in step 4) into a mold, let it stand and cure at 15 - 40 °C for 36 - 96 h, then demold to obtain a fluorophlogopite glass - ceramic green body;

[0013] 6) Dry the fluorophlogopite glass - ceramic green body prepared in step 5) to constant weight, and calcine it at 850 - 1250 °C for 2 - 12 h to obtain fluorophlogopite glass - ceramic.

[0014] Furthermore, in step 1), the particle size of the fluorophlogopite powder is 13 - 150 μm.

[0015] Furthermore, in step 1), the glass powder is one of SiO2 - Al2O3 - CaO system glass powder, SiO2 - Al2O3 - CaO - B2O3 system glass powder, and SiO2 - B2O3 - Na2O / K2O system glass powder, and the particle size is ≤10 μm.

[0016] Furthermore, in step 1), the ceramic powder is one of silica powder, alumina powder, and mullite powder, with a purity ≥99.5 wt% and a particle size ≤10 μm.

[0017] Furthermore, in step 2), the dispersant is at least one of styrene - maleic anhydride copolymer, pentaethylenehexamine, tetraethylenepentamine, amide - ammonium salt type isobutylene maleic anhydride copolymer, and isobutylene maleic anhydride copolymer.

[0018] Furthermore, in step 3), the ceramic balls are one of alumina, zirconia, and agate ceramic balls.

[0019] Further, in step 4), the binder is one of 1,4-butanediol diglycidyl ether, diglycidyl ether, amide-ammonium salt type isobutene maleic anhydride copolymer, polyethylene glycol diglycidyl ether, and isobutene maleic anhydride copolymer.

[0020] The present invention also provides a high-strength fluorophlogopite glass-ceramics, which is prepared by the above preparation method.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. By reasonably controlling the proportions of the dispersant, binder, deionized water, etc., the fluorophlogopite glass-ceramics blank can be prepared through ball milling, defoaming, casting, drying, and sintering. The process is simple and easy to form.

[0023] 2. During the preparation process of the present invention, directly using fluorophlogopite, glass powder, and ceramic powder as the main raw materials, the price is low, the requirements for equipment are low, it is easy to scale up production, and it has great industrialization prospects.

[0024] 3. The present invention has the advantages of simple process, easy preparation of large-sized fluorophlogopite ceramics, low cost, etc.; the fluorophlogopite glass-ceramics prepared by this method have high density, high strength, and great application prospects.

[0025] Of course, it is not necessary for any product implementing the present invention to achieve all the above advantages simultaneously. Specific Embodiments

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. 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.

[0027] The related specific embodiments of the present invention are as follows:

[0028] Example 1

[0029] A preparation method of a high-strength fluorophlogopite glass-ceramics, comprising the following steps: 1) Mix 60 wt% of fluorophlogopite powder and 40% of SiO2-Al2O3-CaO system glass powder evenly to obtain a mixed powder;

[0030] 2) According to the mass ratio of dispersant: deionized water of 0.085:1, dissolve the dispersant in deionized water and stir rapidly for 2 - 5 min to obtain a solution;

[0031] 3) According to the ratio of ceramic balls: mixed powder: deionized water of 7:3.5:1, put the ceramic balls, the mixed powder prepared in step 1), and the solution prepared in step 2) into a ball mill tank, and ball mill for 30 min to obtain a pre-mixed slurry;

[0032] 4) According to the mass ratio of binder: deionized water of 0.12:1, add the binder to the pre-mixed slurry, ball mill for 60 min to obtain a mixed slurry, and vacuum defoam the slurry for 15 min to obtain a glass-ceramic slurry of fluorophlogopite;

[0033] 5) Inject the glass-ceramic slurry of fluorophlogopite prepared in step 4) into a mold, stand and cure at 20 °C for 72 h, and demold to obtain a fluorophlogopite glass-ceramic green body;

[0034] 6) Dry the fluorophlogopite glass-ceramic green body prepared in step 5) to constant weight, and calcine at 1180 °C for 2 h to obtain a fluorophlogopite glass-ceramic with a flexural strength of 120.6 MPa.

[0035] In this example, the dispersant is a mixture of styrene-maleic anhydride copolymer and tetraethylenepentamine, and their mass ratio is 1:1; the binder is 1,4-butanediol diglycidyl ether.

[0036] Example 2

[0037] A preparation method of high-strength fluorophlogopite glass-ceramic, comprising the following steps:

[0038] 1) Mix 67 wt% of fluorophlogopite powder, 25% of SiO2-Al2O3-CaO-B2O3 system glass powder, and 8% of silica powder evenly to obtain a mixed powder;

[0039] 2) According to the mass ratio of dispersant: deionized water of 0.009:1, dissolve the dispersant in deionized water, and stir rapidly for 2 - 5 min to obtain a solution;

[0040] 3) According to the ratio of ceramic balls: mixed powder: deionized water of 6:3:1, put the ceramic balls, the mixed powder prepared in step 1), and the solution prepared in step 2) into a ball mill tank, and ball mill for 30 min to obtain a pre-mixed slurry;

[0041] 4) According to the mass ratio of binder: deionized water of 0.006:1, add the binder to the pre-mixed slurry, ball mill for 60 min to obtain a mixed slurry, and vacuum defoam the slurry for 15 min to obtain a glass-ceramic slurry of fluorophlogopite;

[0042] 5) Inject the glass-ceramic slurry of fluorophlogopite prepared in step 4) into a mold, stand and cure at 20 °C for 48 h, and demold to obtain a fluorophlogopite glass-ceramic green body;

[0043] 6) Dry the fluorphlogopite glass-ceramic green body prepared in step 5) to constant weight, and calcine it at 1180 °C for 2 h to obtain fluorphlogopite glass-ceramic with a flexural strength of 112.2 MPa.

[0044] In this example, the dispersant is styrene-maleic anhydride copolymer; the binders are all isobutylene maleic anhydride copolymers.

[0045] Example 3

[0046] A preparation method of high-strength fluorphlogopite glass-ceramic, comprising the following steps:

[0047] 1) Mix 60 wt% fluorphlogopite powder, 28% SiO2-Al2O3-CaO system glass powder and 12% alumina powder evenly to obtain a mixed powder;

[0048] 2) Dissolve the dispersant in deionized water according to the mass ratio of dispersant: deionized water of 0.009:1, and stir rapidly for 2 - 5 min to obtain a solution;

[0049] 3) According to the ratio of ceramic balls: mixed powder: deionized water of 6:3:1, place the ceramic balls, the mixed powder prepared in step 1) and the solution prepared in step 2) in a ball mill jar, and ball mill for 30 min to obtain a premixed slurry;

[0050] 4) Add the binder to the premixed slurry according to the mass ratio of binder: deionized water of 0.006:1, ball mill for 60 min to obtain a mixed slurry, and remove air bubbles from the slurry under vacuum for 15 min to obtain a glass-ceramic slurry;

[0051] 5) Inject the glass-ceramic slurry prepared in step 4) into a mold, let it stand and cure at 20 °C for 48 h, and demold to obtain a fluorphlogopite glass-ceramic green body;

[0052] 6) Dry the fluorphlogopite glass-ceramic green body prepared in step 5) to constant weight, and calcine it at 1210 °C for 2 h to obtain fluorphlogopite glass-ceramic with a flexural strength of 124.7 MPa.

[0053] In this example, both the dispersant and the binder are amide-ammonium salt type isobutylene maleic anhydride copolymers.

[0054] Example 4

[0055] A preparation method of high-strength fluorphlogopite glass-ceramic, comprising the following steps:

[0056] 1) Mix 60 wt% fluorphlogopite powder and 40% SiO2-Al2O3-CaO-B2O3 system glass powder evenly to obtain a mixed powder;

[0057] 2) Dissolve the dispersant in deionized water according to the mass ratio of the dispersant to deionized water being 0.09:1, and stir rapidly for 2 - 5 min to obtain a solution.

[0058] 3) According to the mass ratio of ceramic balls: mixed powder: deionized water being 7:3.5:1, place the ceramic balls, the mixed powder prepared in step 1), and the solution prepared in step 2) into a ball - milling tank, and ball - mill for 30 min to obtain a pre - mixed slurry.

[0059] 4) According to the mass ratio of the binder to deionized water being 0.15:1, add the binder to the pre - mixed slurry, ball - mill for 60 min to obtain a mixed slurry, and vacuum - defoam the slurry for 15 min to obtain a mica glass - ceramic slurry.

[0060] 5) Inject the mica glass - ceramic slurry prepared in step 4) into a mold, let it stand and cure at 20°C for 72 h, and then demold to obtain a fluorophlogopite mica glass - ceramic green body.

[0061] 6) Dry the fluorophlogopite mica glass - ceramic green body prepared in step 5) to constant weight, and calcine it at 1210°C for 2 h to obtain a fluorophlogopite mica glass - ceramic with a flexural strength of 121.1 MPa.

[0062] In this example, the dispersant is pentaethylenehexamine; the binder is diglycidyl ether.

[0063] Example 5

[0064] A preparation method of a high - strength fluorophlogopite mica glass - ceramic, comprising the following steps:

[0065] 1) Mix 70 wt% fluorophlogopite powder, 20% glass powder of the SiO2 - B2O3 - Na2O system, and 10% mullite powder evenly to obtain a mixed powder.

[0066] 2) Dissolve the dispersant in deionized water according to the mass ratio of the dispersant to deionized water being 0.06:1, and stir rapidly for 2 - 5 min to obtain a solution.

[0067] 3) According to the mass ratio of ceramic balls: mixed powder: deionized water being 7:3.5:1, place the ceramic balls, the mixed powder prepared in step 1), and the solution prepared in step 2) into a ball - milling tank, and ball - mill for 40 min to obtain a pre - mixed slurry.

[0068] 4) According to the mass ratio of the binder to deionized water being 0.12:1, add the binder to the pre - mixed slurry, ball - mill for 60 min to obtain a mixed slurry, and vacuum - defoam the slurry for 30 min to obtain a mica glass - ceramic slurry.

[0069] 5) Inject the glass-ceramic slurry prepared in step 4) into a mold, let it stand and solidify at 20 °C for 72 h, and then demold to obtain a fluorophlogopite glass-ceramic green body;

[0070] 6) Dry the fluorophlogopite glass-ceramic green body prepared in step 5) to a constant weight, and calcine it at 850 °C for 2 h to obtain a fluorophlogopite glass-ceramic with a flexural strength of 108.4 MPa.

[0071] In this example, the dispersant is tetraethylenepentamine; the binder is polyethylene glycol diglycidyl ether.

[0072] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A preparation method of a high-strength fluorophlogopite glass-ceramics, characterized in that, It comprises the following steps: 1) Mix 30 - 80 wt% fluorophlogopite powder, 20 - 70 wt% glass powder and 0 - 25 wt% ceramic powder evenly to obtain a mixed powder; 2) Dissolve a dispersant in deionized water according to the mass ratio of dispersant:deionized water being (0.009 - 0.09):1, and stir rapidly for 2 - 5 min to obtain a solution; 3) According to the mass ratio of ceramic balls:mixed powder:deionized water being (6 - 9):(3 - 4.5):1, place the ceramic balls, the mixed powder prepared in step 1) and the solution prepared in step 2) in a ball mill tank, and ball mill for 15 - 180 min to obtain a pre - mixed slurry; 4) According to the mass ratio of binder:deionized water being (0.006 - 0.15):1, add a binder to the pre - mixed slurry, ball mill for 30 - 120 min to obtain a mixed slurry, and degas the slurry under vacuum for 15 - 60 min to obtain a glass - ceramic slurry of fluorophlogopite; 5) Inject the glass - ceramic slurry of fluorophlogopite prepared in step 4) into a mold, stand and cure at 15 - 40 °C for 36 - 96 h, and demold to obtain a fluorophlogopite glass - ceramic green body; 6) Dry the fluorophlogopite glass - ceramic green body prepared in step 5) to constant weight, and calcine it at 850 - 1250 °C for 2 - 12 h to obtain fluorophlogopite glass - ceramic; 2. The preparation method according to claim 1, characterized in that, In step 1), the particle size of the fluorophlogopite powder is 13 - 150 μm.

3. The preparation method according to claim 1, characterized in that, In step 1), the glass powder is one of SiO2 - Al2O3 - CaO system glass powder, SiO2 - Al2O3 - CaO - B2O3 system glass powder, SiO2 - B2O3 - Na2O / K2O system glass powder, and the particle size is ≤10 μm.

4. The preparation method according to claim 1, wherein In step 1), the ceramic powder is one of silicon oxide powder, alumina powder, mullite powder, with a purity ≥99.5 wt% and a particle size ≤10 μm.

5. The preparation method according to claim 1, characterized in that In step 2), the dispersant is at least one of styrene - maleic anhydride copolymer, pentaethylenehexamine, tetraethylenepentamine, amide - ammonium salt type isobutene maleic anhydride copolymer, isobutene maleic anhydride copolymer.

6. The preparation method according to claim 1, wherein, In step 3), the ceramic balls are one of alumina, zirconia, agate ceramic balls.

7. The preparation method according to claim 1, wherein In step 4), the binder is one of 1,4 - butanediol diglycidyl ether, diglycidyl ether, amide - ammonium salt type isobutene maleic anhydride copolymer, polyethylene glycol diglycidyl ether, isobutene maleic anhydride copolymer.

8. A high - strength fluorophlogopite glass - ceramic, which is prepared by the preparation method according to any one of claims 1 - 7.