Functional ceramic blank and preparation method thereof

Abstract

The invention relates to the technical field of ceramic materials, in particular to a functional ceramic blank and a preparation method thereof. The invention overcomes the problem that the existing ceramic blank is difficult to give consideration to both light weight and mechanical properties. The synthetic raw materials comprise kaolin, mullite, talc, a composite light filler, a modified reinforcing agent, an interface modifier and a functional additive. The preparation method comprises the following steps: crushing kaolin, mullite and talcum powder, mixing, sequentially adding the rest components, mixing again, adding deionized water, and carrying out ball milling to obtain a ceramic blank; according to the invention, all the components have a synergistic effect, the density is reduced by utilizing the light filler, the mechanical property is improved through the components such as the modified reinforcing agent and the interface modifier, and the obtained blank has good plasticity and good product performance and has a good application prospect in the light building industry.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic materials, and specifically to a functional ceramic blank and a preparation method thereof. Background Art

[0002] With the development of the construction industry towards green and energy-saving directions, lightweight building materials have become a research hotspot in the modern construction field due to their advantages such as reducing the self-weight of buildings, decreasing transportation energy consumption, and improving construction efficiency. Ceramic materials are widely used in the construction field due to their good durability, fire resistance, and decorative properties. However, traditional ceramic materials have a relatively large density and are difficult to meet the requirements of lightweight buildings. Therefore, developing ceramic blanks with both lightweight characteristics and excellent properties has become the key to promoting the innovative application of ceramic materials in the construction field.

[0003] Currently, in order to achieve the lightweight of ceramic blanks, the existing technologies mainly carry out research from two aspects. On the one hand, the density of the blank is reduced by adding lightweight fillers such as hollow glass microspheres and expanded perlite. On the other hand, processes such as the foaming method and the pore-forming agent method are used to introduce pore structures inside the ceramics. In addition, some studies have tried to optimize the proportion of traditional ceramic raw materials and improve the comprehensive properties of the blank by means of coupling agent modification and other means.

[0004] Although certain progress has been made in the existing technologies, there are still many problems. Adding lightweight fillers easily leads to a decrease in the interfacial bonding force inside the blank, significantly reducing the mechanical properties of the material. During the process of introducing pore structures, the pore size and distribution are difficult to precisely control, and pore agglomeration or too large pore diameter is likely to occur, affecting the properties such as the strength and waterproofness of the material. At the same time, the existing research often only focuses on the improvement of a single property, lacking systematic research on the synergistic optimization of lightweight and multiple properties such as mechanical properties and functionality, and it is difficult to prepare high-performance lightweight ceramic blanks that meet the diverse needs of modern buildings. In summary, the current ceramic blanks have the problem of being difficult to balance lightweight and mechanical properties, which affects the use of ceramics in the construction industry.

[0005] Therefore, a functional ceramic blank and a preparation method thereof are proposed. Summary of the Invention

[0006] The purpose of the present invention is to design a functional ceramic blank and a preparation method thereof. The synthetic raw materials of the present invention include kaolin, mullite, talc, composite lightweight filler, modification enhancer, interface modifier, and functional additive; first, kaolin, mullite, and talc are crushed and processed, and after mixing, the remaining components are added in sequence. After mixing again, deionized water is added for ball milling to obtain the ceramic blank. In the present invention, each component acts synergistically, using lightweight fillers to reduce the density and at the same time enhancing the mechanical properties through components such as modification enhancers and interface modifiers. The obtained blank product has good performance and has good application prospects in the lightweight construction industry.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] In one aspect, the present invention provides a functional ceramic blank, which comprises the following components in parts by weight:

[0009] Kaolin: 20-30 parts; Mullite: 10-20 parts; Talc: 35-45 parts; Composite lightweight filler: 15-25 parts; Modified reinforcing agent: 3-7 parts; Interface modifier: 1-5 parts; Functional additive: 1-5 parts;

[0010] Modified reinforcing agents include nanosilica, carbon fiber, polyvinyl alcohol, glycerol, and dibutyl phthalate;

[0011] The interface modifiers include silane coupling agent KH-550, aluminate coupling agent DL-411 and composite nanoclay;

[0012] Functional additives include aerogel powder, expanded perlite and nano-titanium dioxide.

[0013] Preferably, the composite lightweight filler includes hollow glass microspheres and diatomaceous earth, and the weight ratio of the hollow glass microspheres to the diatomaceous earth is 2-4:1.

[0014] Another aspect of the present invention provides a method for preparing a functional ceramic blank, the method comprising the following steps:

[0015] S1: talc, kaolin, and mullite are crushed separately, then put into a high-speed mixer and mixed at a speed of 600 rpm for 20 minutes to obtain a pretreated raw material;

[0016] S2: adding composite lightweight filler, modifying reinforcing agent, interfacial modifier and functional additive to the pretreated raw material in sequence, mixing at a speed of 600 rpm for 10 minutes after each addition of the raw material, and stirring for another 30 minutes after all the components are added to obtain a mixed material;

[0017] S3: adding deionized water to the mixture, wherein the weight ratio of the mixture to deionized water is 1:0.3-0.5, and ball milling is performed in a ball mill for 4 hours to obtain a ceramic blank.

[0018] Preferably, the specific process of the pulverization treatment is: talc is placed in a pulverizer and pulverized to a particle size of 2 μm, followed by vacuum drying; kaolin is first preliminarily pulverized in a pulverizer, then placed in a ball mill and ground at 400 rpm for 1 h-3 h, passed through a 300 mesh sieve, and finally vacuum dried; mullite is placed in a grinder and ground, the discharge particle size is adjusted to 3 μm-5 μm, and then placed in a muffle furnace and calcined at 800 ° C for 2 h.

[0019] Preferably, the preparation method of the modified reinforcing agent is as follows: Add 2-4 parts of nano-silica into 30 parts of absolute ethanol, and ultrasonically disperse for 30 min to obtain a silica dispersion; Place 1-3 parts of carbon fiber in a nitric acid solution with a concentration of 5%, soak it in a water bath at 60 °C for 50 min - 70 min, take it out, rinse it with deionized water until neutral, and then vacuum dry for 2 h to obtain pretreated carbon fiber; Sequentially add the silica dispersion, pretreated carbon fiber, 1-2 parts of polyvinyl alcohol, 0.5-1.5 parts of glycerol and 0.5 part of dibutyl phthalate into a high-speed mixer, and stir at a speed of 800 rpm for 30 min - 60 min to obtain the modified reinforcing agent.

[0020] Preferably, the preparation method of the interfacial modifier is as follows: Dry 1-2 parts of composite nano-clay at 150 °C for 2 h - 4 h to obtain pretreated composite nano-clay; Add 0.5-2.5 parts of silane coupling agent KH-550, 1-3 parts of aluminate coupling agent DL-411 and pretreated composite nano-clay into a reaction kettle, and stir and mix at 80 °C at a speed of 300 rpm for 1 h - 3 h to obtain the interfacial modifier; The composite nano-clay includes montmorillonite and sepiolite, and the weight ratio of montmorillonite to sepiolite is 2:1 - 3.

[0021] Preferably, the preparation method of the functional auxiliary is as follows: Pass 1-3 parts of aerogel powder through a 200-mesh sieve and dry it in a vacuum environment for 2 h to obtain pretreated aerogel; Soak 2-4 parts of expanded perlite in an aqueous solution of silane coupling agent KH-550 with a concentration of 3%, take it out after soaking at room temperature for 1 h - 3 h, and dry it at 100 °C for 8 h to obtain modified expanded perlite; Mix the pretreated aerogel, modified expanded perlite and 1-2 parts of nano-titanium dioxide in a mixer at a speed of 150 rpm for 20 min - 40 min to obtain the functional auxiliary.

[0022] Preferably, the composition of talc is: about 31.6% MgO, about 62.4% SiO2, about 4.5% H2O, and the rest is Al2O3, Fe2O3; The composition of kaolin is: about 38.2% Al2O3, about 46.1% SiO2, about 14% H2O, and the rest is impurities; The composition of mullite is: about 70.8% Al2O3, about 27.1% SiO2, and the rest is impurities such as CaO.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. Kaolin, mullite, and talc form the basic framework, and the composite lightweight filler composed of hollow glass microspheres and diatomite is evenly dispersed therein. The hollow glass microspheres significantly reduce the density of the green body due to their hollow structure, and the porous properties of diatomite further reduce the weight. At the same time, the adhesiveness of kaolin, the high strength of mullite, and the lubricity of talc, in cooperation with the lightweight filler, maintain the structural stability of the green body while reducing the density. The lightweight of the ceramic blank is achieved, the density is significantly reduced, meeting the requirements of lightweight building materials; at the same time, a certain mechanical strength is ensured, broadening the application scope of the product in the construction field.

[0025] 2. Nano-silica, carbon fiber, polyvinyl alcohol, glycerol, and dibutyl phthalate form a modified reinforcing agent. Nano-silica fills the micro-pores to enhance the density, carbon fiber provides a high-strength framework, and polyvinyl alcohol, glycerol, and dibutyl phthalate enhance the plasticity through hydrogen bonding and lubrication effects, and also build a flexible buffer system inside the green body. During the temperature change process, this system can absorb and buffer thermal stress, reduce the internal stress caused by thermal expansion and contraction, and avoid the generation and expansion of cracks. This multi-scale synergistic effect effectively improves the mechanical properties of the ceramic blank, optimizes the internal structure and stress distribution of the green body, significantly improves the thermal stability, and meets the requirements of high-performance applications.

[0026] 3. Silane coupling agent KH-550, aluminate coupling agent DL-411, and composite nano-clay form an interfacial modifier. The silane coupling agent reacts with the surface hydroxyl groups of the raw materials to form chemical bonds, the aluminate coupling agent reduces the surface energy and enhances the compatibility, and the composite nano-clay fills the particle gaps. The three work together to build a stable interfacial layer on the surface of the raw materials, enhancing the compatibility and bonding force between the components in the ceramic blank, reducing the internal defects of the raw materials, and improving the mechanical properties of the green body.

[0027] 4. Aerogel powder, expanded perlite, and nano-titanium dioxide constitute functional additives. Aerogel powder has an extremely low density and high porosity, and expanded perlite also has good lightweight characteristics after treatment, forming more pore structures in the green body, increasing the air content, and thus further reducing the density of the ceramic blank; they act together with the composite lightweight filler to further enhance the density reduction effect. Nano-titanium dioxide in the functional additives can refine the ceramic grains, improve the densification of the ceramic, and thus enhance the mechanical properties. Brief Description of the Drawings

[0028] Figure 1 It is a graph of the flexural strength and bulk density of Example 11 and Comparative Examples 17-21 in the present invention. Detailed Description of the Invention

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] The raw materials used in the present invention can all be obtained from commercially available products.

[0031] Specifically refer to Figure 1 , the present invention provides a functional ceramic blank and a preparation method thereof, and the technical solutions are as follows:

[0032] Example 1

[0033] Add 3 parts of nano-silica into 30 parts of absolute ethanol, and ultrasonically disperse for 30 min to obtain a silica dispersion; place 2 parts of carbon fiber in a nitric acid solution with a concentration of 5%, soak in a water bath at 60 °C for 60 min, take out and rinse with deionized water until neutral, and then vacuum dry for 2 h to obtain pretreated carbon fiber; sequentially add the silica dispersion, pretreated carbon fiber, 1.5 parts of polyvinyl alcohol, 1 part of glycerol and 0.5 part of dibutyl phthalate into a high-speed mixer, and stir at a speed of 800 rpm for 45 min to obtain a modified enhancer.

[0034] Dry 1.5 parts of composite nano-clay at 150 °C for 3 h to obtain pretreated composite nano-clay; add 1.5 parts of silane coupling agent KH-550, 2 parts of aluminate coupling agent DL-411 and pretreated composite nano-clay into a reaction kettle, and stir and mix at 80 °C at a speed of 300 rpm for 2 h to obtain an interfacial modifier; the composite nano-clay includes montmorillonite and sepiolite, and the weight ratio of montmorillonite to sepiolite is 2:2.

[0035] Pass 2 parts of aerogel powder through a 200-mesh sieve and dry in a vacuum environment for 2 h to obtain pretreated aerogel; soak 3 parts of expanded perlite in an aqueous solution of silane coupling agent KH-550 with a concentration of 3%, take out after soaking at room temperature for 2 h, and dry at 100 °C for 8 h to obtain modified expanded perlite; mix the pretreated aerogel, modified expanded perlite and 1.5 parts of nano-titanium dioxide in a mixer at a speed of 150 rpm for 30 min to obtain a functional additive.

[0036] Prepare a ceramic blank:

[0037] S1 Crush 40 parts of talc, 25 parts of kaolin, and 15 parts of mullite separately, then put them into a high-speed mixer and mix at a speed of 600 rpm for 20 min to obtain pretreated raw materials. The process of crushing treatment is as follows: Put talc into a crusher and crush it until the particle size reaches 2 μm, and then carry out vacuum drying; First, preliminarily crush kaolin in a crusher, then put it into a ball mill and grind it at 400 rpm for 2 h, sieve it through a 300-mesh sieve, and finally carry out vacuum drying; Put mullite into a grinding mill and grind it, adjust the discharge particle size to 4 μm, and then put it into a muffle furnace and calcine it at 800 °C for 2 h.

[0038] S2 Add 20 parts of composite lightweight filler, 5 parts of modified reinforcing agent, 3 parts of interfacial modifier, and 3 parts of functional additive to the pretreated raw materials in sequence. After adding each raw material, mix for 10 min. After all components are added, stir for another 30 min to obtain a mixed material. The composite lightweight filler includes hollow glass microspheres and diatomite, and the weight ratio of hollow glass microspheres to diatomite is 3:1.

[0039] S3 Add deionized water to the mixed material. The weight ratio of the mixed material to deionized water is 1:0.4, and ball mill it in a ball mill for 4 h to obtain a ceramic blank.

[0040] Examples 1-12 Refer to the parameter conditions in Example 1, and the specific differences are shown in Table 1.

[0041] Table 1 Parameter conditions of Examples 1-12

[0042]

[0043]

[0044] Comparative Example 1 Refer to the parameter conditions in Example 1, the difference is that kaolin is not added.

[0045] Comparative Example 2 Refer to the parameter conditions in Example 1, the difference is that mullite is not added.

[0046] Comparative Example 3 Refer to the parameter conditions in Example 1, the difference is that talc is not added.

[0047] Comparative Example 4 Refer to the parameter conditions in Example 1, the difference is that only hollow glass microspheres are added as the lightweight filler.

[0048] Comparative Example 5 Refer to the parameter conditions in Example 1, the difference is that only diatomite is added as the lightweight filler.

[0049] Comparative Example 6 Refer to the parameter conditions in Example 1, the difference is that the composite lightweight filler is not added.

[0050] Comparative Example 7 Refer to the parameter conditions in Example 1, the difference is that kaolin, mullite, and talc are not subjected to crushing treatment.

[0051] After firing the ceramics obtained from all the examples and comparative examples, tests were carried out.

[0052] All the parameter conditions of Example 1, Example 4, Example 7, and Example 10 are the same.

[0053] Mechanical property and density test of Experimental Example 1

[0054] In accordance with GB / T 1966-2024, the densities of Examples 1-3 and Comparative Examples 1-7 were measured, and a universal material testing machine was used to test the flexural properties of Examples 1-3 and Comparative Examples 1-7. The results are shown in Table 2.

[0055] Table 2 Mechanical property and density test of Examples 1-3 and Comparative Examples 1-7

[0056] Example Flexural strength / MPa <![CDATA[Bulk density / g / cm 3 > Example 1 81 1.49 Example 2 78 1.53 Example 3 76 1.55 Comparative Example 1 62 1.40 Comparative Example 2 67 1.45 Comparative Example 3 64 1.42 Comparative Example 4 74 1.61 Comparative Example 5 72 1.58 Comparative Example 6 68 1.72 Comparative Example 7 70 1.49

[0057] As can be seen from Table 2, kaolin plays a certain role in providing viscosity and plasticity in the blank. The lack of it in Comparative Example 1 will lead to poor formability of the green body, reduced flexural strength, and due to the absence of kaolin, the density of the overall blank will also decrease. Mullite has high strength and high-temperature resistance, which makes important contributions to the mechanical properties of ceramics. In Comparative Example 2, the lack of it will cause a significant decrease in flexural strength. At the same time, the absence of mullite will cause the green body to shrink greatly during firing, and the density will change. Talc can improve the processing performance and sintering performance of the blank. In Comparative Example 3, the absence of talc will lead to incomplete sintering of the green body, reduced flexural strength, and the density will also decrease due to sintering problems. In Comparative Examples 4-5, only a single lightweight filler is used, which will increase the density of the ceramic blank. The main function of the composite lightweight filler is to reduce the density. In Comparative Example 6, the absence of it will increase the density of the ceramic, and at the same time, it will affect the synergistic effect of other properties, resulting in a change in flexural strength. In Comparative Example 7, if kaolin, mullite, and talc are not pulverized, the raw material particles will be larger, the mixing will be uneven, and the structure of the green body will be incomplete, thus reducing the flexural strength, and the density will also change due to particle packing problems. In the examples, kaolin provides viscosity and plasticity, making the green body easy to form. After being mixed with other materials, it helps to form a uniform green body structure, improving the overall density and mechanical properties; mullite has high strength and high-temperature resistance, playing a role in strengthening the framework in the green body, and cooperating with other materials to improve the flexural strength and high-temperature resistance of the ceramics; talc improves the processing performance of the blank, making the green body more dense during sintering, and cooperating with kaolin, mullite, etc. to optimize the sintering performance and mechanical properties of the ceramics. The composite lightweight filler can reduce the density of the ceramics, and at the same time interact with other materials to achieve lightweighting without significantly reducing the mechanical properties, and may have a certain optimization effect on the microstructure of the green body, helping to improve other properties.

[0058] Comparative Example 8 refers to the parameter conditions in Example 4, with the difference that nano-silica is not added to the modified reinforcing agent.

[0059] Comparative Example 9 refers to the parameter conditions in Example 4, with the difference that carbon fiber is not added to the modified reinforcing agent.

[0060] Comparative Example 10 refers to the parameter conditions in Example 4, with the difference that polyvinyl alcohol is not added to the modified reinforcing agent.

[0061] Comparative Example 11 refers to the parameter conditions in Example 4, with the difference that glycerol is not added to the modified reinforcing agent.

[0062] Comparative Example 12 refers to the parameter conditions in Example 4, with the difference that the modified reinforcing agent is not added.

[0063] Experimental Example 2 Mechanical Property and Thermal Stability Tests

[0064] The flexural properties of Examples 4-6 and Comparative Examples 8-12 were tested using a universal material testing machine, and the thermal stability was detected according to the national standard. That is, Examples 4-6 and Comparative Examples 8-12 were placed on an electric furnace and heated to a bottom temperature of 450 °C, and then instantly poured into 100 ml of cold water at 20 °C. It was considered qualified if there was no crack after rapid cooling once. The obtained results are shown in Table 3.

[0065] Table 3 Mechanical properties and thermal stability tests of Examples 4-6 and Comparative Examples 8-12

[0066] Example Flexural strength / MPa Thermal stability Example 4 81 Qualified Example 5 77 Qualified Example 6 76 Qualified Comparative Example 8 68 Qualified Comparative Example 9 65 Qualified Comparative Example 10 70 Qualified Comparative Example 11 71 Qualified Comparative Example 12 56 Unqualified

[0067] It can be found from Table 3 that nano-silica has a high specific surface area and high activity, can fill the pores in the ceramic matrix, improve the density of the material, and at the same time chemically bond or physically adsorb with other components to enhance the interfacial bonding force, thereby improving the flexural strength and thermal stability. In Comparative Example 8, without adding nano-silica, the internal pores of the material increase and the interfacial bonding becomes weaker, resulting in a decrease in flexural strength and a deterioration in thermal stability. Carbon fiber has the characteristics of high strength and high modulus, can play a role in strengthening and toughening in the ceramic matrix, bear part of the load, and prevent crack propagation. In Comparative Example 9, lacking carbon fiber, the material is prone to cracks and rapid crack propagation when stressed, the flexural strength decreases, and it is also more likely to crack due to insufficient toughness during thermal shock. Polyvinyl alcohol can form a network structure in the ceramic green body, increase the plasticity and bonding strength of the green body, and make each component better combined. In Comparative Example 10, without adding polyvinyl alcohol, the forming performance of the green body becomes poor, the internal structure is not dense enough, and defects are prone to occur during the firing process, resulting in a decrease in flexural strength and thermal stability. The presence of glycerol makes the ceramic green body softer during the processing process, is conducive to the uniform mixing and forming of each component, and can improve the internal microstructure of the material and reduce stress concentration. In Comparative Example 11, lacking glycerol, microcracks will be generated in the material due to uneven internal stress during the processing process, reducing the flexural strength, and at the same time the thermal stability will also be affected. The various components in the modified reinforcing agent act synergistically to jointly improve the mechanical properties and thermal stability of the ceramic material. In Comparative Example 12, without adding the modified reinforcing agent, the material loses the filling and strengthening of nano-silica, the toughening of carbon fiber, the bonding of polyvinyl alcohol, and the lubrication and plasticization of glycerol, etc., and the performance will decrease significantly, the flexural strength will be greatly reduced, and the thermal stability is also difficult to meet the requirements.

[0068] Comparative Example 13 referred to the parameter conditions in Example 7, the difference being that no composite nano-clay was added to the interfacial modifier.

[0069] Comparative Example 14 referred to the parameter conditions in Example 7, the difference being that no silane coupling agent KH-550 was added to the interfacial modifier.

[0070] Comparative Example 15 Refer to the parameter conditions in Example 7, the difference is that no DL-411 aluminate coupling agent is added to the interfacial modifier.

[0071] Comparative Example 16 Refer to the parameter conditions in Example 7, the difference is that no interfacial modifier is added.

[0072] Experimental Example 3 Mechanical Property Test

[0073] The flexural properties of Examples 7-9 and Comparative Examples 13-16 were tested using a universal material testing machine, and the results are shown in Table 4.

[0074] Table 4 Mechanical Property Tests of Examples 7-9 and Comparative Examples 13-16

[0075] Example Flexural strength / MPa Example 7 81 Example 8 79 Example 9 77 Comparative Example 13 70 Comparative Example 14 71 Comparative Example 15 71 Comparative Example 16 64

[0076] It can be found from Table 4 that in Comparative Example 13, since the composite nanoclay is not added to the interfacial modifier, the modification effect is incomplete. The composite nanoclay can provide special surface properties and structures, which helps to enhance the interfacial bonding force. The lack of it will make the interfacial bonding slightly weaker, and crack propagation is likely to occur under stress, thus reducing the flexural strength of the ceramic. The silane coupling agent KH-550 can form chemical bonds between different components of the ceramic blank, effectively improving the interfacial bonding strength. In Comparative Example 14, without adding this coupling agent, the bonding force between the components of the blank is weakened, and damage is likely to occur at the interface under external force, further reducing the flexural strength. The aluminate coupling agent DL-411 also plays an important role in improving the interfacial properties. It can react chemically with other components to improve the interfacial compatibility and bonding force. In Comparative Example 15, the lack of this coupling agent makes the bonding effect at the interface worse, the overall mechanical properties of the material decline, and the flexural strength also decreases accordingly. In Comparative Example 16, without adding the interfacial modifier, the interfacial bonding between the components in the blank is in a poor state, and different materials cannot work well together. Under external force, defects and cracks are likely to occur at the interface, resulting in premature failure of the material and a significant reduction in the flexural strength. In the examples, the materials in the interfacial modifier effectively improve the properties of the ceramic blank through synergy. The silane coupling agent KH-550 and the aluminate coupling agent DL-411 can act on the inorganic and organic components in the blank respectively, forming a bridge between different materials and enhancing the interfacial bonding force. The composite nanoclay has a large specific surface area and a special layered structure. It can adsorb on the surface of other particles, further improving the microstructure of the interface, and enhancing the uniformity and stability of the interface. The three materials cooperate with each other, enabling the different components in the ceramic blank to be better combined together to form a tight and uniform overall structure. This good interfacial bonding state helps the stress to be evenly transmitted inside the material, avoiding stress concentration caused by interfacial defects, thereby improving the flexural strength of the ceramic and enabling the ceramic material to better exert its function.

[0077] Comparative Example 17 refers to the parameter conditions in Example 10, with the difference that aerogel powder is not added to the functional auxiliary agent.

[0078] Comparative Example 18 refers to the parameter conditions in Example 10, with the difference that expanded perlite is not added to the functional auxiliary agent.

[0079] Comparative Example 19 refers to the parameter conditions in Example 10, with the difference that nano-titanium dioxide is not added to the functional auxiliary agent.

[0080] Comparative Example 20 refers to the parameter conditions in Example 10, with the difference that the functional auxiliary agent is not added.

[0081] Comparative Example 21 refers to the parameter conditions in Example 10, with the difference that the composite light filler is not added.

[0082] Comparative Example 22 referred to the parameter conditions in Example 10, with the difference that the mixing method in S2 was to add the composite lightweight filler, modified reinforcing agent, interfacial modifier, and functional additives together and stir for 30 min, and the subsequent steps remained unchanged.

[0083] Mechanical property and density tests in Experimental Example 4

[0084] With reference to Experimental Example 1, mechanical properties and density tests were carried out on Examples 10 - 12 and Comparative Examples 17 - 22. The obtained results are shown in Table 5. The flexural strength and bulk density of Example 11 and Comparative Examples 17 - 21 are as Figure 1 shown.

[0085] Table 5 Mechanical property and density tests of Examples 10 - 12 and Comparative Examples 17 - 22

[0086]

[0087]

[0088] From Table 5 and Figure 1It can be found that without adding aerogel powder in Comparative Example 17, the pore structure of the material will not be optimized sufficiently, resulting in an increase in internal defects when stressed, a decrease in the flexural strength. The aerogel powder has a filling effect, and the absence of it slightly increases the bulk density of the material. Expanded perlite has functions such as light weight and heat insulation. Without adding it in Comparative Example 18, the light-weight property of the material will be weakened, leading to an increase in density. At the same time, its supporting effect on the internal structure of the material disappears, and the flexural strength decreases. Nano-titanium dioxide plays roles such as enhancing interfacial bonding and improving the microstructure in the material. The lack of it in Comparative Example 19 will cause the bonding force inside the material to decrease, thus reducing the flexural strength, and having a relatively small impact on the density. Without adding functional additives in Comparative Example 20, various functions cannot be achieved, the comprehensive performance of the material significantly decreases, the flexural strength drops greatly, and due to the lack of components helpful for reducing density, the density increases significantly. The composite lightweight filler plays an important role in reducing density and improving mechanical properties. Without adding it in Comparative Example 21, the material becomes heavier, the density increases significantly, and at the same time, the structural rationality of the material is damaged, and the flexural strength drops severely. In Comparative Example 22, when various materials are added simultaneously, agglomeration will occur, especially for some materials with smaller particle sizes or special properties, which are difficult to be evenly dispersed in the whole system in a short time. This will lead to uneven distribution of the material in the matrix, large local property differences, and thus affect the overall mechanical properties. Functional additives such as aerogel powder, expanded perlite, and nano-titanium dioxide cooperate with the composite lightweight filler. The aerogel powder optimizes the pore structure, the expanded perlite provides light-weight support, and the nano-titanium dioxide enhances interfacial bonding. Acting together with the composite lightweight filler, the material has good mechanical properties while having a low density; they improve the overall performance of the material by improving the microstructure of the material, enhancing the bonding force between components, etc., and achieve a good balance between low density and high flexural strength.

[0089] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A functional ceramic blank, characterized in that: By weight parts, the ceramic blank comprises the following components: Kaolin: 20 - 30 parts; Mullite: 10 - 20 parts; Talc: 35 - 45 parts; Composite lightweight filler: 15 - 25 parts; Modified reinforcing agent: 3 - 7 parts; Interface modifier: 1 - 5 parts; Functional auxiliary agent: 1 - 5 parts; The modified reinforcing agent comprises nano - silica, carbon fiber, polyvinyl alcohol, glycerol and dibutyl phthalate; The interface modifier comprises silane coupling agent KH - 550, aluminate coupling agent DL - 411 and composite nano - clay; The functional auxiliary agent comprises aerogel powder, expanded perlite and nano - titanium dioxide.

2. The functional ceramic blank according to claim 1, wherein: The composite lightweight filler comprises hollow glass microspheres and diatomite, and the weight parts ratio of the hollow glass microspheres to the diatomite is 2 - 4:

1.

3. A method for preparing a functional ceramic blank, characterized in that: To prepare the ceramic blank as claimed in claim 1, the preparation method comprises the following steps: S1 Crush talc, kaolin and mullite respectively, and then put them into a high - speed mixer and mix at a speed of 600 rpm for 20 min to obtain a pretreated raw material; S2 Sequentially add the composite lightweight filler, the modified reinforcing agent, the interface modifier and the functional auxiliary agent into the pretreated raw material. After each addition of the raw material, mix at a speed of 600 rpm for 10 min. After all components are added, stir for another 30 min to obtain a mixed material; S3 Add deionized water to the mixed material, and the weight parts ratio of the mixed material to the deionized water is 1:0.3 - 0.

5. Ball - mill in a ball mill for 4 h to obtain the ceramic blank.

4. The preparation method of a functional ceramic blank according to claim 3, characterized in that: The specific process of the crushing treatment is as follows: Put the talc into a crusher for crushing, and then carry out vacuum drying; First, preliminarily crush the kaolin in the crusher, then put it into a ball mill for grinding for 1 h - 3 h, sieve it and then carry out vacuum drying; Put the mullite into a powder mill for grinding, adjust the particle size of the discharged material to 3 μm - 5 μm, and then put it into a muffle furnace for calcination.

5. The preparation method of a functional ceramic blank according to claim 3, characterized in that: The preparation method of the modified reinforcing agent is as follows: Add 2 - 4 parts of nano - silica into 30 parts of absolute ethanol, and carry out ultrasonic dispersion for 30 min to obtain a silica dispersion liquid; Place 1 - 3 parts of carbon fiber in a 5% nitric acid solution, soak it in a water bath at 60 °C for 50 min - 70 min, take it out, rinse it with deionized water until neutral, and then carry out vacuum drying for 2 h to obtain pretreated carbon fiber; Sequentially add the silica dispersion liquid, the pretreated carbon fiber, 1 - 2 parts of polyvinyl alcohol, 0.5 - 1.5 parts of glycerol and 0.5 part of dibutyl phthalate into a high - speed stirrer, and stir at a speed of 800 rpm for 30 min - 60 min to obtain the modified reinforcing agent.

6. The preparation method of a functional ceramic blank according to claim 3, characterized in that: The preparation method of the interface modifier is as follows: drying 1-2 parts of composite nano-clay at 150 °C for 2-4 h to obtain pretreated composite nano-clay; adding 0.5-2.5 parts of silane coupling agent KH-550, 1-3 parts of aluminate coupling agent DL-411 and the pretreated composite nano-clay into a reaction kettle, and stirring and mixing at 80 °C at a rotation speed of 300 rpm for 1-3 h to obtain the interface modifier; the composite nano-clay includes montmorillonite and sepiolite, and the weight ratio of the montmorillonite to the sepiolite is 2:1-3.

7. The preparation method of a functional ceramic blank according to claim 3, characterized in that: The preparation method of the functional auxiliary is as follows: passing 1-3 parts of aerogel powder through a 200-mesh sieve and drying in a vacuum environment for 2 h to obtain pretreated aerogel; soaking 2-4 parts of expanded perlite in an aqueous solution of silane coupling agent KH-550 with a concentration of 3%, taking it out after soaking at room temperature for 1-3 h, and drying at 100 °C for 8 h to obtain modified expanded perlite; mixing the pretreated aerogel, the modified expanded perlite and 1-2 parts of nano-titanium dioxide in a mixer at a rotation speed of 150 rpm for 20-40 min to obtain the functional auxiliary.

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