Ceramic matrix composite pipe and method of making the same

Abstract

This invention relates to the technical field of tubing, and more particularly to a ceramic-based composite tubing and its preparation method. The ceramic-based composite tubing comprises the following components by weight: 40-60 parts silicon carbide, 20-30 parts clay, 10-15 parts silicon dioxide, 5-15 parts alumina, 5-10 parts silicon powder, and 5-15 parts reinforcing filler, wherein the reinforcing filler is selected from any one or more of carbon fiber, silicon carbide fiber, and carbon nanotubes. The preparation method of the ceramic-based composite tubing includes the following steps: S1, raw material weighing: The raw material is ball-milled and sieved to obtain powdered raw material; the powdered raw material is mixed with clay, dry-pressed, and dried to obtain the material to be sintered; S2, sintering. The combination of alumina and silicon carbide allows silicon carbide to act as a second phase, fixing and strengthening grain boundaries, and shielding cracks, improving the hardness and toughness of the tubing and extending its service life.

Description

Technical Field

[0001] This invention relates to the technical field of feed tubes, and more particularly to a ceramic-based composite feed tube and its preparation method. Background Technology

[0002] In the aluminum alloy die-casting process, molten aluminum alloy is transported through a feed pipe to complete the die casting. The feed pipe is a key consumable component in the aluminum alloy die-casting process, and its service life, performance stability, and other performance indicators decisively affect the final product quality of the aluminum alloy die-casting process.

[0003] Currently, most aluminum alloy die casting machines use hot work die steel H13 tubes. High-temperature resistant coatings are applied to the surface of the tubes to improve their high-temperature resistance. However, after prolonged use, the surface hardness will gradually age and fatigue. The gate area is subjected to chemical corrosion and wear from the molten alloy for a long time, and uneven heating of the inner surface will cause deformation and damage to the tube.

[0004] Therefore, we propose a ceramic-based composite tube and its preparation method to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the aforementioned background technology by proposing a ceramic-based composite tube and its preparation method.

[0006] In a first aspect, this application provides a ceramic-based composite tube comprising the following parts by weight: 40-60 parts silicon carbide, 20-30 parts clay, 10-15 parts silicon dioxide, 5-15 parts alumina, 5-10 parts silicon powder, and 5-15 parts reinforcing filler, wherein the reinforcing filler is selected from any one or more of carbon fiber, silicon carbide fiber, and carbon nanotubes.

[0007] By adopting the above technical solution and using silicon carbide as the substrate of the feed tube, the feed tube acquires excellent properties such as high temperature resistance, oxidation resistance, corrosion resistance, and wear resistance, making it less prone to damage and extending its service life. The combination of alumina and silicon carbide allows alumina to act as a second phase, fixing and strengthening grain boundaries, shielding cracks, and improving the hardness and toughness of the feed tube.

[0008] Adding carbon fiber to the tube substrate does not change the main phase of silicon carbide, but it effectively enhances the bonding tightness between the components in the tube substrate and can form an entanglement skeleton structure in the tube substrate. By supporting and improving the bonding tightness of the substrate, it stabilizes and improves the strength and density of the tube.

[0009] Adding silicon carbide fibers to the tubing substrate improves the bonding effect between the silicon carbide fibers and the tubing substrate, allowing the silicon carbide fibers to pull the components in the tubing substrate, thus stabilizing and enhancing the strength and density of the tubing.

[0010] Adding carbon nanotubes to the substrate of the tube, including both single-cell and aggregated forms, allows the carbon nanotubes to attract and pull the substrate, improving its density and strength. Simultaneously, the addition of carbon nanotubes can inhibit the growth of some grains in the substrate, reducing the possibility of voids caused by excessively large grains, further enhancing the tube's density and strength.

[0011] Optionally, the silicon carbide fiber is a carbon-coated silicon carbide nanowire.

[0012] By adopting the above technical solution, silicon carbide nanowires are added to the substrate of the tube. The silicon carbide nanowires have a high aspect ratio, enabling them to pull and anchor the substrate, thereby improving its density. Using carbon-coated silicon carbide nanowires effectively reduces the van der Waals forces and specific surface area of ​​the nanowires, weakens entanglement between them, and allows for ideal bonding between the nanowires and the substrate. This reduces the number of undesirable interfacial structures in the tube. Furthermore, the carbon layer, acting as an intermediate layer, further enhances the interfacial bonding between the silicon carbide nanowires and the substrate, stabilizing and strengthening the tube and extending its service life.

[0013] Optionally, the preparation method of the carbon-coated silicon carbide nanowires includes the following steps: immersing silicon carbide nanowires in toluene, ultrasonicating, heating and stirring, filtering, retaining the solid, and drying to obtain a surface-treated product; immersing the surface-treated product in a phenolic resin modified solution, ultrasonicating, stirring, filtering, retaining the solid, washing, and drying to obtain a product coated with phenolic resin; sintering the product coated with phenolic resin to obtain a sintered product, and acidifying the sintered product to obtain carbon-coated silicon carbide nanowires.

[0014] By employing the above technical solution, phenolic resin is coated onto the surface of silicon carbide nanowires. The phenolic resin and silicon carbide nanowires form a core-shell structure, protecting the silicon carbide nanowires from damage. After sintering, the phenolic resin undergoes carbonization, forming a bamboo-like carbonized layer on the silicon carbide surface, increasing the bonding strength between the silicon carbide nanowires and the substrate. The sintered product is then acidified. This acidification process grafts carboxyl functional groups onto the surface of the sintered product, reducing the aggregation of silicon carbide nanowires and resulting in uniform strength for the substrate.

[0015] Optionally, the reinforcing filler may further include boron nitride nanosheets.

[0016] By employing the above technical solution, boron nitride nanosheets possess a layered hexagonal crystal structure, enabling them to be intercalated and anchored within the tube substrate. This introduces a sheet-like structure into the tube, filling the pores in the substrate and hindering crack formation, thus stabilizing and improving the tube's strength and impact resistance. Simultaneously, the sheet-like structure of the boron nitride nanosheets introduces an isolation layer within the tube, preventing corrosive elements from eroding it and improving its corrosion resistance. Furthermore, due to the inertness and hydrophobicity of the boron nitride nanosheets, they promote the dispersion of components within the tube, preventing excessive aggregation and resulting in uniform density, strength, and corrosion resistance.

[0017] Optionally, a portion of the boron nitride may be coated onto the silicon carbide fibers.

[0018] By adopting the above technical solution, boron nitride can be used to coat silicon carbide fibers, thereby increasing the thickness of the silicon carbide fibers and forming a coating layer on the surface of the silicon carbide fibers. The coating layer can retain some layered structures, enhance the specific surface area and surface roughness of the silicon carbide fibers, further enhance the bonding strength and pinning effect of the silicon carbide fibers in the tube substrate, and thus improve the strength of the tube.

[0019] Optionally, the reinforcing filler may further include any one or more of andalusite, magnesium oxide, or titanium dioxide.

[0020] By adopting the above technical solution, andalusite is added to the substrate of the tube. Andalusite itself can undergo mullitization, transforming into mullite and silica-rich glass phase, which can then undergo secondary mullitization with alumina in the tube substrate. This is beneficial for the sintering of the tube and effectively improves the density of the tube.

[0021] When magnesium oxide is present, it can form aluminum magnesium spinel at the grain boundaries, which can coat the surface of silicon carbide particles, hindering the growth of silicon carbide grains, making the grain size in the tubing substrate uniform, and improving the compactness of the tubing.

[0022] When titanium dioxide is added to the substrate of the feed tube, it can form a solid solution phase with the mullite solid solution, which intensifies lattice distortion, promotes diffusion, and promotes the secondary mullite formation reaction of alumina. This can effectively reduce the sintering temperature of the feed tube and promote its sintering.

[0023] By combining andalusite, magnesium oxide, and titanium dioxide, the substrate in the feed tube can undergo secondary mullitization through its own mullite phase and solid solution phase, thereby promoting the sintering of the feed tube. It can also refine the grain size of each component in the feed tube substrate, resulting in a dense feed tube. In addition, titanium and magnesium elements can be more evenly distributed around the silicon carbide particles, further promoting the sintering effect of the feed tube.

[0024] Optionally, the alumina includes nano-alumina and an alumina 3D framework.

[0025] By adopting the above technical solution, nano-alumina and an alumina 3D skeleton are added to the substrate of the feed tube. The nano-alumina can be uniformly dispersed in the feed tube and can form a stable interface bond with silicon carbide, enhancing the density and strength of the feed tube. The addition of the alumina 3D skeleton can combine with the fiber network structure of the filler, stably enhancing the strength of the feed tube. Furthermore, because the alumina 3D skeleton can form a strong interface bond with the nano-alumina, it can improve the bonding effect between the filler and alumina, further increasing the bonding strength between the components inside the feed tube, and improving the density, strength, and corrosion resistance of the feed tube.

[0026] Optionally, the ceramic-based composite tubing may also include 1-3 parts by weight of a polyzirconane-polycarbosilane hybrid precursor polymer.

[0027] By adopting the above technical solution, the polyzirconium carbide-polycarbosilane hybrid precursor polymer has abundant active crosslinking sites. During the sintering process of the tube, the hybrid precursor structure can catalyze and promote the coupling reaction between active groups such as NH and Si-R, promote the crosslinking of active groups in each component of the tube substrate, and the precursor can pre-form a crosslinking network structure to encapsulate each component in the tube substrate, inhibit grain growth in the tube substrate, refine the grains, further improve the compactness of the tube, and enable the tube to obtain better high temperature resistance and stably extend the service life of the tube.

[0028] Optionally, the composite tube is coated with a coating comprising the following components by weight: 50-55 parts alumina, 40 parts aluminum phosphate, 1-2 parts zinc phosphate, 0.1-1 parts boron nitride, and 0.1-1 parts graphene.

[0029] By employing the above technical solution, alumina particles are added to the coating, enabling it to bond more tightly to the tube during the curing process and reducing the likelihood of coating detachment. During curing, boron nitride not only acts as a nucleation site for the binder phase, promoting coating solidification, but also seals the pores between alumina particles and on the tube surface, reducing surface defects and effectively improving the tube's corrosion resistance. Graphene is also added to the coating. Both graphene and boron nitride are layered structures, synergistically forming an isolation layer within the coating. Furthermore, the hydrophobic properties of boron nitride promote uniform dispersion of graphene within the coating, resulting in a uniform and dense corrosion-resistant effect. The isolation layer formed by graphene and boron nitride also possesses excellent thermal conductivity, facilitating heat dispersion and further reducing the possibility of heat-induced tube breakage.

[0030] Secondly, this application provides a method for preparing a ceramic-based composite tube, comprising the following steps: S1, raw material weighing: silicon carbide, clay, silicon dioxide, alumina, silicon powder and reinforcing filler are weighed according to weight parts, silicon carbide, silicon dioxide, alumina, silicon powder and reinforcing filler are ball-milled and sieved to obtain powdered raw materials, the powdered raw materials are mixed with clay, dry-pressed and dried to obtain the material to be fired; S2, sintering: the material to be fired is placed in a sintering device and sintered at atmospheric pressure to obtain the composite tube.

[0031] In summary, this application has the following technical effects:

[0032] 1. The combination of alumina and silicon carbide allows alumina to act as a second phase to fix and strengthen grain boundaries, shield cracks, and improve the hardness and toughness of the feed tube.

[0033] Adding carbon fiber to the tube substrate can effectively enhance the bonding tightness between the components in the tube substrate, and can cause entanglement in the tube substrate to form a skeleton structure. By supporting the skeleton and improving the bonding tightness of the substrate, the strength and density of the tube can be steadily improved.

[0034] Silicon carbide fiber has good compatibility with the tube substrate, which improves the bonding effect between the silicon carbide fiber and the tube substrate. This allows the silicon carbide fiber to pull the components in the tube substrate, thus stabilizing and enhancing the strength and density of the tube.

[0035] Carbon nanotubes, in their single-tube form, can attract and pull on the substrate, improving the density and strength of the nanotube. Simultaneously, they can inhibit the growth of some grains in the substrate, reducing the possibility of voids caused by excessively large grains, further enhancing the density and strength of the nanotube.

[0036] 2. The use of carbon-coated silicon carbide nanowires can effectively reduce the van der Waals forces and specific surface area of ​​silicon carbide nanowires, weaken the entanglement between silicon carbide nanowires, and enable silicon carbide nanowires to be ideally composited with the material substrate. This reduces the number of undesirable interface structures in the tube, and the carbon layer, as an intermediate layer, further enhances the interfacial bonding force between the silicon carbide nanowires and the material substrate, stabilizing and strengthening the tube and extending its service life.

[0037] 3. Boron nitride nanosheets possess a layered hexagonal crystal structure, enabling them to be intercalated and anchored within the tube substrate. This plate-like structure not only fills the pores in the substrate but also inhibits crack formation, stabilizing and improving the tube's strength and impact resistance. Simultaneously, the plate-like structure of boron nitride nanosheets introduces an isolation layer into the tube, hindering corrosive elements from eroding it and improving its corrosion resistance. Furthermore, the inertness and hydrophobicity of boron nitride nanosheets promote the dispersion of components within the tube, preventing excessive aggregation and resulting in uniform density, strength, and corrosion resistance.

[0038] 4. Graphene was added to the coating. Both graphene and boron nitride have sheet-like structures, which can synergistically construct an isolation layer in the coating. Furthermore, due to the hydrophobic properties of boron nitride, it promotes the uniform dispersion of graphene in the coating, resulting in a uniform and dense corrosion-resistant coating. In addition, the isolation layer constructed from graphene and boron nitride has excellent thermal conductivity, which is beneficial for dispersing heat and further reduces the possibility of the feed tube breaking due to heat. Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments.

[0040] Preparation Example

[0041] Example of Reinforcing Filler Preparation

[0042] Preparation Examples 1-9

[0043] Carbon fiber, silicon carbide fiber, carbon nanotubes, boron nitride, andalusite, magnesium oxide, and titanium dioxide were taken and mixed to prepare reinforcing fillers 1-9.

[0044] Table 1. Composition of reinforcing fillers in Preparation Examples 1-9

[0045]

[0046] Preparation Example 10

[0047] Carbon-coated silicon carbide nanowires

[0048] 0.1 kg of silicon carbide nanowires were immersed in 1.5 L of toluene, sonicated for 30 min, and then heated in an oil bath at 150 °C under an inert gas atmosphere with magnetic stirring. The mixture was then filtered, the solid was retained, and dried at 80 °C for 6 h to obtain a surface-treated product. 0.1 kg of the surface-treated product was added to 80 L of water, 32 L of anhydrous ethanol, and 0.4 L of ammonia. The mixture was sonicated for 30 min, then 0.6 kg of resorcinol was added and stirred. A 38% formaldehyde solution was added, and the mixture was stirred continuously to wash away unreacted substances. The product was dried at 80 °C for 6 h to obtain a product coated with phenolic resin. The phenolic resin-coated product was vacuum sintered to obtain a sintered product. The sintered product was placed in a container, and 65% concentrated nitric acid and 98% concentrated sulfuric acid were added. The mixture was sonicated, stirred at 200 rpm, filtered, the solid was retained, washed, and vacuum dried to obtain carbon-coated silicon carbide nanowires.

[0049] Preparation Example 11

[0050] Using BCl3 and NH3 as the reaction gas source, and Ar as the carrier gas and dilution gas, the pressure of the reaction system was 5 kPa, and the ratio of the reaction gas was NH3:BCl3:Ar = 3:1:5 (mL / min). Boron nitride was deposited on silicon carbide fibers to prepare silicon carbide fibers coated with boron nitride.

[0051] Preparation Example 12

[0052] The difference from Preparation Example 4 is that an equal mass of carbon-coated silicon carbide nanowires was used instead of silicon carbide fibers in Preparation Example 4 to prepare reinforcing filler 10.

[0053] Preparation Example 13

[0054] The preparation method of polyzirconium carbide-polycarbosilane hybrid precursor polymer includes the following steps: using xylene as solvent, polyzirconium carbide (PZC) and polycarbosilane (CS) are mixed at a mass ratio of 1:10, and magnetically stirred at 120°C under a nitrogen atmosphere for 4 hours to obtain a homogeneous yellow solution. After filtration, the solvent is removed by vacuum distillation to obtain a light yellow polyzirconium carbide-polycarbosilane hybrid precursor polymer.

[0055] Preparation Example 14

[0056] The method for preparing a 3D alumina skeleton includes the following steps: impregnating a three-dimensional mesh polyurethane sponge in alumina slurry, drying it with microwave, sintering it at 1600℃ under an argon atmosphere and holding it at that temperature for 3 hours to obtain a 3D alumina skeleton.

[0057] Preparation Example 15

[0058] 5 kg of nano-alumina and 1 kg of 3D alumina framework were mixed to prepare alumina 1.

[0059] Coating preparation example

[0060] Preparation Examples 16-18

[0061] Alumina, aluminum phosphate, zinc phosphate, boron nitride, and graphene were taken separately and mixed to obtain coatings 1-3.

[0062] Table 2. Coating composition of preparation examples 16-18

[0063] weight / kg Preparation Example 16 Preparation Example 17 Preparation Example 18 Alumina 50 53 55 Aluminum phosphate 40 40 40 Zinc phosphate 1 1.6 2 Boron nitride 0.1 0.5 1 graphene 0.1 0.5 1

[0064] Example

[0065] Examples 1-3

[0066] This application provides a ceramic-based composite tube, comprising the following materials: silicon carbide, clay, silicon dioxide, alumina, silicon powder, and reinforcing filler 1, the specific quantities of which are shown in Table 3.

[0067] This application also provides a method for preparing a ceramic-based composite tube, comprising the following steps:

[0068] S1. Raw material weighing: Weigh silicon carbide, clay, silicon dioxide, alumina, silicon powder and reinforcing filler 1 according to the weight parts. Take silicon carbide, silicon dioxide, alumina, silicon powder and reinforcing filler, ball mill, sieve to obtain powdered raw materials. Mix the powdered raw materials with clay, dry press into shape, dry to obtain the material to be fired.

[0069] S2. Sintering: The material to be sintered is placed in a sintering device and sintered under normal pressure to obtain a composite material tube.

[0070] Table 3 Composition of Composite Pipes in Examples 1-3

[0071] weight / kg Example 1 Example 2 Example 3 silicon carbide 40 50 60 clay 30 25 20 silicon dioxide 10 12 15 Alumina 5 10 15 Reinforced packing 1 5 10 15 silicon powder 5 8 10

[0072] Example 4-12

[0073] The difference from Example 2 is that: equal mass of reinforcing filler 2-10 is used to replace reinforcing filler 1 in Example 2 to prepare composite tubes.

[0074] Example 13

[0075] The difference from Example 4 is that the silicon carbide fiber includes equal mass of carbon-coated silicon carbide nanowires and silicon carbide fiber coated with boron nitride, in place of the silicon carbide fiber in Example 2, that is, in place of the reinforcing filler 2 in Example 2, to prepare the composite tube.

[0076] Example 14

[0077] The difference from Example 2 is that an equal mass of alumina 1 is used instead of the alumina in Example 2 to prepare the composite tube.

[0078] Example 15

[0079] The difference from Example 2 is that the feed tube also includes 2 kg of polyzirconane-polycarbosilane hybrid precursor polymer to prepare a composite feed tube.

[0080] Examples 16-18

[0081] The difference from Example 2 is that: coating 1-3 is applied to the inner and outer walls of the composite tube respectively, and cured at high temperature to prepare the composite tube.

[0082] Comparative Example

[0083] Comparative Example 1

[0084] The difference from Example 2 is that no alumina was added in this comparative example to prepare the composite tube.

[0085] Comparative Example 2

[0086] The difference from Example 2 is that no reinforcing filler was added in this comparative example to prepare the composite tube.

[0087] Performance testing

[0088] 1. Fracture toughness testing

[0089] The fracture toughness of the composite material was tested using an electronic universal testing machine. The test method was the three-point bending fracture method of a single-sided notched beam, and the sample size was 2mm×4mm×2mm.

[0090] 2. Wear resistance test

[0091] The bending strength of the composite tube was tested according to GB / T4741-1999 "Test Method for Bending Strength of Ceramic Materials". The sample size was 5mm×5mm×35mm, the loading rate was 0.5mm / min, and each sample was tested 3 times. The average value was taken as the result.

[0092] 3. Corrosion resistance test

[0093] The corrosion resistance of composite tubes was measured using a three-electrode system on an electrochemical workstation.

[0094] Table 4 Performance Test Table for Composite Pipes

[0095]

[0096]

[0097] Referring to the performance test comparison in Table 4, we can find that:

[0098] 1. A comparison of Examples 1-3, Examples 4-6, and Comparative Examples 1-2 reveals that the fracture toughness of the composite tubes prepared in Examples 1-3 is improved. This indicates that in this application, the combination of alumina and silicon carbide allows alumina to act as a second phase, fixing and strengthening grain boundaries, and shielding cracks, thus improving the hardness and toughness of the tube. Adding carbon fibers, silicon carbide fibers, and carbon nanotubes to the tube substrate increases the bonding tightness between the components and forms a skeletal structure, improving the strength and density of the tube. Simultaneously, it inhibits the growth of some grains in the tube substrate, reducing the possibility of voids caused by excessively large grains, further improving the density and strength of the tube.

[0099] 2. A comparison between Example 7 and Example 2 reveals that the composite tube prepared in Example 7 exhibits improved fracture toughness and corrosion resistance. This indicates that the boron nitride nanosheets in this application possess a layered hexagonal crystal structure, enabling them to be intercalated and anchored within the tube substrate. Introducing a sheet-like structure into the tube not only fills the pores in the substrate but also hinders crack formation, thus stabilizing and improving the tube's strength and impact resistance. Furthermore, the sheet-like structure of the boron nitride nanosheets can introduce an isolation layer into the tube, preventing corrosive elements from eroding it and improving its corrosion resistance.

[0100] 3. A comparison of Examples 8-10, 11 and 2 reveals that the composite tubes prepared in Examples 8-11 exhibit improved fracture toughness and corrosion resistance. This indicates that the combination of andalusite, magnesium oxide and titanium dioxide in this application can promote secondary mullitization of the substrate in the tube through its own mullite phase and solid solution phase, thereby promoting the sintering of the tube. It can also refine the grain size of each component in the substrate, resulting in a dense tube structure. Furthermore, titanium and magnesium elements can be more uniformly distributed around the silicon carbide particles, further promoting the sintering effect of the tube.

[0101] 4. A comparison of Examples 12, 13, and 4 reveals that the fracture toughness of the composite tubes prepared in Examples 12-12 is improved. This indicates that the use of carbon-coated silicon carbide nanowires in this application can reduce the entanglement between silicon carbide nanowires, enabling ideal composite formation between the silicon carbide nanowires and the substrate, reducing the number of undesirable interface structures in the tube. Furthermore, the carbon layer, as an intermediate layer, further enhances the interfacial bonding force between the silicon carbide nanowires and the tube substrate, stabilizing and strengthening the tube's strength and extending its service life. Boron nitride nanosheets have a layered hexagonal crystal structure and can be intercalated and anchored in the tube substrate. Introducing a sheet-like structure into the tube not only fills the pores in the substrate but also hinders crack formation, stabilizing and improving the tube's strength and impact resistance.

[0102] 5. A comparison between Examples 16-18 and Example 2 reveals that the composite tubes prepared in Examples 16-18 exhibit improved fracture toughness and corrosion resistance. This indicates that boron nitride in this application not only acts as a nucleation site for the binder phase, promoting coating curing, but also seals the pore structure between alumina particles and the pore structure on the tube surface, reducing surface defects and effectively improving the corrosion resistance of the tube. Both graphene and boron nitride are layered structures, enabling them to synergistically construct an isolation layer in the coating. This isolation layer not only provides excellent corrosion resistance but also superior thermal conductivity.

[0103] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A ceramic-based composite pipe, characterized in that, It comprises the following components by weight: 40-60 parts silicon carbide, 20-30 parts clay, 10-15 parts silicon dioxide, 5-15 parts alumina, 5-10 parts silicon powder and 5-15 parts reinforcing filler, wherein the reinforcing filler is silicon carbide fiber, and the silicon carbide fiber is carbon-coated silicon carbide nanowire. The method for preparing carbon-coated silicon carbide nanowires includes the following steps: immersing silicon carbide nanowires in toluene, ultrasonicating, heating and stirring, filtering, retaining the solid, and drying to obtain a surface-treated product; immersing the surface-treated product in a phenolic resin modified solution, ultrasonicating, stirring, filtering, retaining the solid, washing, and drying to obtain a product coated with phenolic resin; sintering the product coated with phenolic resin to obtain a sintered product, and acidifying the sintered product to obtain carbon-coated silicon carbide nanowires. It also includes 1-3 parts by weight of polyzirconane-polycarbosilane hybrid precursor polymer.

2. The ceramic-based composite tube according to claim 1, characterized in that, The reinforcing filler also includes boron nitride nanosheets.

3. The ceramic-based composite tube according to claim 2, characterized in that, The boron nitride is partially coated onto the silicon carbide fiber.

4. The ceramic-based composite tube according to claim 1, characterized in that, The reinforcing filler also includes any one or more of andalusite, magnesium oxide, or titanium dioxide.

5. A ceramic-based composite tube according to claim 1, characterized in that, The alumina includes nano-alumina and an alumina 3D framework.

6. The ceramic-based composite tube according to claim 1, characterized in that, The composite tube is coated with a coating comprising the following components by weight: 50-55 parts alumina, 40 parts aluminum phosphate, 1-2 parts zinc phosphate, 0.1-1 parts boron nitride, and 0.1-1 parts graphene.

7. A method for preparing a ceramic-based composite tube according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Raw material weighing: Weigh silicon carbide, clay, silicon dioxide, alumina, silicon powder and reinforcing filler according to the weight parts. Take silicon carbide, silicon dioxide, alumina, silicon powder and reinforcing filler, ball mill them, sieve them to obtain powdered raw materials. Mix the powdered raw materials with clay, dry press them into shape, dry them to obtain the material to be fired. S2. Sintering: The material to be sintered is placed in a sintering device and sintered under normal pressure to obtain a composite material tube.

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