Ultrahigh-temperature-resistant heat-proof and heat-insulating integrated material and forming method thereof

Abstract

The invention belongs to the technical field of thermal protection composite materials, and particularly relates to an ultrahigh-temperature-resistant heat prevention and insulation integrated material and a forming method thereof. Comprising a fiber skeleton, a ceramic layer, an aerogel heat insulation layer and a surface compact layer, a fiber cloth isolation layer is arranged between the ceramic layer and the aerogel heat insulation layer, and the material of the fiber cloth isolation layer is the same as or different from the fiber material of the fiber skeleton. The outer layer is ablation-resistant, the middle layer is reflection / oxygen barrier, the inner layer is efficient in heat insulation, the whole body is borne and sheared by a three-dimensional fiber network, and finally the light integrated thermal protection material is obtained.

Description

Technical Field

[0001] This application belongs to the field of thermal protection composite materials technology, and in particular relates to an integrated material for ultra-high temperature resistance and thermal insulation and its molding method. Background Technology

[0002] Thermal protective composite materials must withstand prolonged high temperatures (>1600℃), high dynamic pressure, and strong oxidative coupling environments under special conditions. Traditional multi-layer splicing solutions of "heat-resistant tiles + insulation felt" suffer from weak interlayer adhesive shear, insufficient coating temperature resistance, and easy delamination after repeated use, leading to thermal short circuits or even catastrophic failures. While a single ultra-high temperature ceramic dense shell is oxidation-resistant, its high density and brittleness make it impossible to balance lightweight and thermal insulation. Existing technologies attempt to reduce brittleness through fiber-reinforced ceramic matrix composites; however, ceramic slurry easily seeps into the insulation layer during impregnation, increasing weight, and the fiber skeleton lacks rigidity, resulting in irreversible deformation under prolonged high dynamic pressure. This makes it difficult to meet the integrated requirements of "lightweight, high-strength, high-efficiency thermal insulation, and oxidation resistance" for reusable aircraft. Summary of the Invention

[0003] This application provides an integrated heat-insulating material resistant to ultra-high temperatures and its molding method to solve the following technical problem: how to mold a lightweight integrated heat protection material with high-temperature ablation resistance, high-efficiency heat insulation, high shear strength and low density in one step.

[0004] In a first aspect, embodiments of this application provide an integrated material for ultra-high temperature resistant heat insulation, comprising: a fiber skeleton, a ceramic layer, an aerogel heat insulation layer, and a dense surface layer; The fiber skeleton is a needle-punched fiber preform or a three-dimensional woven fiber preform, and the fiber material of the fiber skeleton is selected from at least one of carbon fiber, quartz fiber, mullite fiber and alumina fiber. The ceramic layer is a layer formed by vacuum impregnation and drying of ultra-high temperature ceramic powder, wherein the ultra-high temperature ceramic powder is selected from at least one of ZrB2 and HfB2. The aerogel insulation layer is a carbon aerogel layer; The surface dense layer is a dense layer formed by chemical vapor deposition of SiC. A fiber cloth isolation layer is provided between the ceramic layer and the aerogel insulation layer. The material of the fiber cloth isolation layer may be the same as or different from the fiber material of the fiber skeleton.

[0005] Optionally, before forming the ceramic layer, the fiber skeleton undergoes vacuum heating pretreatment, organic solvent immersion treatment, drying treatment, chemical vapor deposition carbon coating treatment, and vacuum heating pre-tempering treatment in sequence.

[0006] Optionally, the ceramic layer is formed by immersing the fiber skeleton in a ceramic slurry under a vacuum of 0.05 atm to 0.1 atm and then repeatedly drying it 2 to 5 times.

[0007] Optionally, the ceramic slurry is prepared by ball milling ultra-high temperature ceramic powder, ethanol and dispersant at a mass ratio of 100:(20-50):(1-3) for 12-48 hours.

[0008] Optionally, the aerogel insulation layer is formed by vacuum impregnating the fiber skeleton with phenolic resin sol, followed by segmented heating and gel curing, solvent replacement, drying, and pyrolysis at 800℃~1000℃; the phenolic resin sol is prepared by mixing phenolic resin, solvent, and catalyst in a mass ratio of 50:(150~200):1.

[0009] Optionally, after pyrolysis, the carbon aerogel layer is further hydrothermally coated with a glucose solution of pH 2-4 and mass fraction 10wt%-20wt% and then pyrolyzed again at 800℃-1000℃ to form a sugar-carbon shell reinforced carbon aerogel insulation layer.

[0010] Optionally, the dense surface layer is formed by passing methyltrichlorosilane and hydrogen in a chemical vapor deposition furnace at a volume ratio of 1:3 to 5, and repeating the deposition-polishing-redeposition process 5 to 20 times at 1000°C to 1200°C until the mass change rate before and after polishing is ≤1%.

[0011] Secondly, this application provides a molding method for an integrated material resistant to ultra-high temperature and providing heat insulation, characterized in that the molding method includes, in sequence: a fiber skeleton preparation step, a skeleton pretreatment step, a ceramic layer prepreg preparation step, an aerogel heat insulation layer introduction step, and a surface densification step. The fiber skeleton preparation step is as follows: lay up a needle-punched fiber preform or a three-dimensional braided fiber preform, wherein the fiber material of the preform is selected from at least one of carbon fiber, quartz fiber, mullite fiber, and alumina fiber. The pretreatment step of the fiber skeleton is as follows: the fiber skeleton is heated at 800℃~1000℃ under vacuum conditions, cooled in the furnace, and then immersed in ethanol or acetone for 6h~12h. Then it is dried at 60℃~70℃ for 6h~24h. The dried fiber skeleton is then placed in a chemical vapor deposition furnace and a carbon coating is deposited at 800℃~1200℃ using methane or acetylene as the reaction gas and hydrogen or argon as the carrier gas. The volume ratio of the reaction gas to the carrier gas is 1:3~5, and the flow rate of the reaction gas is 0.5L / min~1.2L / min. The fiber skeleton after carbon coating is then heated again at 800℃~1300℃ under vacuum to obtain a pre-tempered fiber skeleton. The pre-preparation steps of the ceramic layer are as follows: ultra-high temperature ceramic powder, ethanol and dispersant are ball-milled at a mass ratio of 100:(20-50):(1-3) for 12-48 hours to obtain a ceramic slurry. The pre-tempered fiber skeleton is impregnated with the ceramic slurry under a vacuum of 0.05 atm to 0.1 atm for 0.5-1 hours, and then dried at 60-80℃ for 6-48 hours. The impregnation-drying process is repeated 2-5 times until the mass change rate after drying is ≤1%. The aerogel insulation layer introduction step is as follows: Phenolic resin, solvent and catalyst are prepared into a sol at a mass ratio of 50:(150~200):1. The fiber skeleton containing the ceramic layer is impregnated with the sol under a vacuum of 0.2atm~0.3atm and held under pressure for 10min~20min. After flipping, it is impregnated and held under pressure again, and this process is repeated 2~3 times, with a total holding time of 1h~6h. Then, the impregnated fiber skeleton is placed in a high-pressure reaction vessel and gelled in stages by heating. After curing, solvent replacement, drying and pyrolysis at 800℃~1000℃ are performed in sequence to obtain the carbon aerogel insulation layer. The surface densification step is as follows: the fiber skeleton containing the aerogel insulation layer is placed in a chemical vapor deposition furnace, and after vacuuming, a mixed gas of methyltrichlorosilane and hydrogen in a volume ratio of 1:3 to 5 is introduced. Deposition is carried out at 1000℃ to 1200℃. After the initial deposition, the surface is polished and the deposition-polishing process is repeated 5 to 20 times until the mass change rate after polishing is ≤1%, thus forming a dense surface layer.

[0012] Optionally, in the step of introducing the aerogel insulation layer, the temperature-time sequence for the segmented heating gel curing is as follows: 60℃~90℃ for 1h~2h, 100℃~120℃ for 1h~2h, 130℃~150℃ for 0.5h~1h, and 160℃~190℃ for 1h~2h.

[0013] Optionally, after pyrolysis, the carbon aerogel insulation layer is further immersed in a glucose solution with a pH of 2-4 and a mass fraction of 10wt%-20wt%, then hydrothermally heated at 170-190℃ for 4-6 hours in a high-pressure reaction vessel, followed by drying at 60℃-80℃ and secondary pyrolysis at 800℃-1000℃ to form a sugar-carbon shell-reinforced carbon aerogel insulation layer.

[0014] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides an integrated material for ultra-high temperature resistance and heat insulation. Based on the principle of "structure-function integration", it breaks down the four conflicting requirements of ablation resistance, high heat insulation, high shear and lightweight into different spatial scales and forms a whole in one go.

[0015] The fiber skeleton (needle-punched / 3D braided) provides a continuous reinforcing network at the millimeter-centimeter scale, directly transferring shear loads to high-modulus carbon fibers or ceramic fibers to achieve high shear strength; at the same time, the porous skeleton itself has low density, ensuring macroscopic lightweight.

[0016] On the surface of the skeleton filament bundle, a micron-sized "armor shell" is formed by vacuum impregnation and drying of the ZrB2 / HfB2 ultra-high temperature ceramic layer. Its high melting point, low oxygen diffusion coefficient, and self-generated B2O3 oxide film can melt and seal instantaneously at temperatures above 1800°C, blocking oxygen diffusion into the interior and solving the problem of high-temperature ablation resistance.

[0017] The inner side of the ceramic shell is isolated with fiber cloth of the same material, which not only prevents leakage of subsequent carbon aerogel precursors, but also retains fiber bridging to ensure interlayer shear continuity.

[0018] Carbon aerogel is generated in situ within the fiber fabric. The nanoporous structure (pore size <50nm) imparts extremely low solid-phase thermal conductivity and the Knudsen effect, effectively blocking conductive and radiative heat flow from the high-temperature side, achieving highly efficient thermal insulation; the carbon skeleton density is only 0.1–0.3 g / cm³. 3 It also takes into account lightweight design.

[0019] The outermost layer is a dense SiC layer deposited by CVD, which fills the surface microcracks, reduces the oxidation rate and increases the surface emissivity, reflects the radiant heat back to the outside, and forms a smooth aerodynamic surface to reduce mass erosion.

[0020] The four layers are sequentially filled in a single vacuum impregnation-sol-gel-CVD process, with the fiber skeleton serving as a shared "mold" and reinforcing phase, avoiding adhesive interfaces and achieving "one-step molding". The functions of each layer are decoupled but the structure is continuous: the outer layer is ablation resistant, the middle layer is reflective / oxygen barrier, and the inner layer is highly efficient insulated. The entire structure is supported by a three-dimensional fiber network to withstand shear, ultimately resulting in a lightweight, integrated thermal protection material. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the ultra-high temperature resistant and heat-insulating integrated material provided in the embodiments of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1~6" cover all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "including" and "contains" as used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship; "and / or" indicates that multiple situations can exist individually or simultaneously; expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.

[0026] Figure 1 This is a structural schematic diagram of the ultra-high temperature resistant and heat-insulating integrated material provided in the embodiments of this application, as shown below. Figure 1 As shown: In a first aspect, embodiments of this application provide an integrated material for ultra-high temperature resistant heat insulation, comprising: a fiber skeleton, a ceramic layer 1, an aerogel heat insulation layer 2, and a dense surface layer 3; The fiber skeleton is a needle-punched fiber preform or a three-dimensional woven fiber preform, and the fiber material of the fiber skeleton is selected from at least one of carbon fiber, quartz fiber, mullite fiber and alumina fiber. The ceramic layer 1 is a layer formed by vacuum impregnation and drying of ultra-high temperature ceramic powder, wherein the ultra-high temperature ceramic powder is selected from at least one of ZrB2 and HfB2. The aerogel insulation layer 2 is a carbon aerogel layer; The surface dense layer 3 is a dense layer formed by chemical vapor deposition of SiC. A fiber cloth isolation layer 4 is provided between the ceramic layer 1 and the aerogel insulation layer 2. The fiber cloth isolation layer 4 may be made of the same or different fiber material as the fiber skeleton.

[0027] The fiber skeleton is made of needle-punched fiber preforms or three-dimensional woven fiber preforms, and the fiber material is selected from at least one of carbon fiber, quartz fiber, mullite fiber, and alumina fiber, thereby providing ≤0.65g / cm³. 3 The lightweight matrix possesses an in-plane shear strength of ≥30MPa at room temperature; the ceramic layer 1 is formed by vacuum impregnation and drying of ZrB2 or HfB2 ultra-high temperature ceramic powder, thereby providing a linear ablation rate of ≤0.05mm / s under ablation conditions based on an oxygen-containing environment at 1600℃; the aerogel insulation layer 2 is a carbon aerogel layer, thereby locking the normal thermal conductivity at 800℃ in the range of 0.03W / m / K~0.08W / m / K; the surface dense layer 3 is a dense layer formed by chemical vapor deposition of SiC, thereby suppressing oxygen permeability to ≤1×10 -6 g / cm 2 / s; The fiber cloth isolation layer 4 is located between the ceramic layer 1 and the aerogel insulation layer 2, and its material is the same as or different from the fiber material of the fiber skeleton, thereby blocking the penetration path of the ceramic slurry into the aerogel insulation layer 2 and avoiding a weight gain of 0.05g / cm. 3 ~0.15g / cm 3 The above five-layer structure is formed in one step within the same material, thus solving the problem of "how to form a structure that simultaneously possesses 1600℃ ablation resistance, high-efficiency heat insulation, high shear strength, and a density ≤0.65g / cm³ in one step". 3 The technical problem of "lightweight integrated thermal protection materials".

[0028] Examples of fiber skeleton density values: 0.20 g / cm³, 0.25 g / cm³, 0.30 g / cm³, 0.35 g / cm³, 0.40 g / cm³, 0.45 g / cm³, 0.50 g / cm³, 0.55 g / cm³, 0.60 g / cm³, 0.65 g / cm³; Examples of ablation rate values ​​for ceramic layer 1: 0.01 mm / s, 0.02 mm / s, 0.03 mm / s, 0.04 mm / s, 0.05 mm / s; Examples of thermal conductivity values ​​for aerogel insulation layer 2: 0.03 W / m / K, 0.04 W / m / K, 0.05 W / m / K, 0.06 W / m / K, 0.07 W / m / K, 0.08 W / m / K; Examples of oxygen permeability values: 1 × 10⁻⁶. -6 g / cm 2 / s, 5×10 -7 g / cm 2 / s, 1×10 -7 g / cm 2 / s, 5×10 -8 g / cm 2 / s, 1×10 -8 g / cm 2 / s; Examples of weight gain inhibition interval values: 0.05g / cm3, 0.06g / cm3, 0.07g / cm3, 0.08g / cm3, 0.09g / cm3, 0.10g / cm3, 0.11g / cm3, 0.12g / cm3, 0.13g / cm3, 0.14g / cm3, 0.15g / cm3.

[0029] In some embodiments, the fiber skeleton undergoes vacuum heating pretreatment, organic solvent immersion treatment, drying treatment, chemical vapor deposition carbon coating treatment, and vacuum heating pre-tempering treatment in sequence before forming the ceramic layer 1.

[0030] Vacuum heating pretreatment at 800℃~1000℃ removes the slurry from the fiber skeleton surface and pre-sets it, thereby locking the initial porosity of the fiber skeleton at 60%~75%; organic solvent immersion treatment uses ethanol or acetone to dissolve residual adhesive residue, thereby increasing the surface energy of the fiber skeleton by 5mJ / m 2 ~15mJ / m 2 The drying process removes the solvent at 60℃~70℃ to prevent the carbon coating from peeling off due to solvent boiling during the subsequent CVD stage. The chemical vapor deposition carbon coating treatment introduces a 0.1μm~0.5μm thick carbon interface layer at 800℃~1200℃, thereby reducing the difference in thermal expansion coefficients between the fiber skeleton and ceramic layer 1 from 5×10⁻⁶. -6 K -1 Reduced to 1×10 -6 K -1 The carbon coating is partially graphitized by a second vacuum heating pre-tempering treatment at 800℃~1300℃, thereby increasing the compressive strength of the fiber skeleton from 50MPa to 120MPa. This five-step pretreatment chain endows the fiber skeleton with the rigidity to withstand a 1600℃ thermal shock, further supporting claim 1's solution to "how to form a fiber skeleton in one step that possesses 1600℃ ablation resistance, high thermal insulation, high shear strength, and a density ≤0.65g / cm³". 3 The technical problem of "lightweight integrated thermal protection materials".

[0031] Examples of vacuum heating pretreatment temperatures: 800℃, 825℃, 850℃, 875℃, 900℃, 925℃, 950℃, 975℃, 1000℃; Examples of porosity values: 60%, 62%, 64%, 66%, 68%, 70%, 72%, 74%, 75%; Example of surface energy enhancement: 5 mJ / m 2 7mJ / m 2 9mJ / m 211mJ / m2, 13mJ / m2, 15mJ / m2; Examples of carbon coating thickness values: 0.1μm, 0.15μm, 0.2μm, 0.25μm, 0.3μm, 0.35μm, 0.4μm, 0.45μm, 0.5μm; Examples of compressive strength values: 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, 100MPa, 110MPa, 120MPa.

[0032] In some embodiments, the ceramic layer 1 is formed by immersing the fiber skeleton in a ceramic slurry under a vacuum of 0.05 atm to 0.1 atm and then repeatedly drying it 2 to 5 times. The ceramic slurry is prepared by ball milling ultra-high temperature ceramic powder, ethanol and dispersant in a mass ratio of 100:(20 to 50):(1 to 3) for 12 to 48 hours.

[0033] Vacuuming at 0.05 atm to 0.1 atm removes residual gas from the fiber skeleton, thereby increasing the ceramic slurry filling rate from 75% to ≥95%. Repeated drying 2 to 5 times gradually reduces cracks and porosity, locking the final porosity of ceramic layer 1 at 3% to 8%. Ball milling for 12 to 48 hours reduces the particle size D50 of ZrB2 or HfB2 powder to 0.5 μm to 1.2 μm, thereby increasing the flexural strength of ceramic layer 1 from 80 MPa to 250 MPa. A dispersant mass ratio of 1 to 3 prevents particle agglomeration, thus controlling the thermal conductivity of ceramic layer 1 within the range of 8 W / m / K to 12 W / m / K. These parameters work synergistically to ensure that ceramic layer 1 maintains an intact shell at 1600℃, further supporting claim 1's solution to "how to form a ceramic layer with 1600℃ ablation resistance, high thermal insulation, high shear strength, and a density ≤0.65 g / cm³ in one step." 3 The technical problem of "lightweight integrated thermal protection materials".

[0034] Examples of vacuum degree values: 0.05 atm, 0.06 atm, 0.07 atm, 0.08 atm, 0.09 atm, 0.10 atm; Examples of filling rate values: 75%, 80%, 85%, 90%, 92%, 94%, 95%; Examples of drying times: 2 times, 3 times, 4 times, 5 times; Examples of ball milling time values: 12h, 16h, 20h, 24h, 28h, 32h, 36h, 40h, 44h, 48h; Particle size D50 number. Examples of values: 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1.0μm, 1.1μm, 1.2μm; Examples of values ​​for bending strength: 80MPa, 100MPa, 120MPa, 140MPa, 160MPa, 180MPa, 200MPa, 220MPa, 250MPa; Examples of values ​​for thermal conductivity: 8W / m / K, 9W / m / K, 10W / m / K, 11W / m / K, 12W / m / K.

[0035] In some embodiments, the aerogel insulation layer 2 is formed by vacuum impregnating the fiber skeleton with phenolic resin sol, followed by segmented heating gel curing, solvent replacement, drying, and pyrolysis at 800°C to 1000°C; the phenolic resin sol is prepared by mixing phenolic resin, solvent, and catalyst in a mass ratio of 50:(150 to 200):1.

[0036] Phenolic resin sol is immersed into the fiber skeleton under a vacuum of 0.2 atm to 0.3 atm, thereby increasing the sol filling rate to ≥90%; segmented heating and gel curing increases the crosslinking density of the phenolic resin from 0.8 × 10⁻⁶ to 0.5 × 10⁻⁶. -3 mol / cm 3 Increased to 1.5×10 -3 mol / cm 3 This process reduces the shrinkage rate of the carbon aerogel from 25% to 8%; solvent replacement removes uncrosslinked monomers, reducing the ash content from 5wt% to ≤1wt%; pyrolysis at 800℃~1000℃ transforms the phenolic resin into a three-dimensional network carbon skeleton, thus locking the compressive modulus of the aerogel insulation layer 2 within the range of 5MPa~20MPa; a mass ratio of 50:(150~200):1 ensures the sol viscosity is between 50mPa·s and 200mPa·s, thereby preventing the clogging of 0.1mm~0.5mm micropores during the impregnation process. These steps ensure that the aerogel insulation layer 2 maintains its nanoporous structure at 1600℃, further supporting claim 1's solution to the technical problem of "how to form a lightweight integrated thermal protection material with 1600℃ ablation resistance, high-efficiency thermal insulation, high shear strength, and a density ≤0.65g / cm3 in one step."

[0037] Examples of vacuum degree values: 0.2 atm, 0.22 atm, 0.24 atm, 0.26 atm, 0.28 atm, 0.3 atm; Examples of fill rate values: 85%, 87%, 89%, 90%, 91%, 92%, 93%, 94%, 95%; Example of crosslinking density value: 0.8 × 10⁻⁶ -3 mol / cm 3 0.9×10 -3 mol / cm 3 1.0×10 -3 mol / cm 3 1.1×10 -3 mol / cm 3 1.2×10 -3 mol / cm 3 1.3×10 -3 mol / cm 3 1.4×10 -3 mol / cm 3 1.5×10-3 mol / cm 3 Examples of shrinkage values: 25%, 22%, 19%, 16%, 13%, 10%, 8%; Examples of ash content values: 5wt%, 4wt%, 3wt%, 2wt%, 1wt%; Examples of pyrolysis temperature values: 800℃, 825℃, 850℃, 875℃, 900℃, 925℃, 950℃, 975℃, 1000℃; Examples of compression modulus values: 5MPa, 7MPa, 9MPa, 11MPa, 13MPa, 15MPa, 17MPa, 19MPa, 20MPa; Examples of viscosity values: 50mPa·s, 70mPa·s, 90mPa·s, 110mPa·s, 130mPa·s, 150mPa·s, 170mPa·s, 190mPa·s, 200mPa·s.

[0038] In some embodiments, the carbon aerogel layer is further hydrothermally coated with a glucose solution of pH 2-4 and mass fraction 10wt%-20wt% after pyrolysis, and then pyrolyzed again at 800℃-1000℃ to form a sugar-carbon shell reinforced carbon aerogel insulation layer 2.

[0039] An acidic environment of pH 2–4 catalyzes the condensation of glucose hydroxyl groups with carboxyl groups on the carbon skeleton surface, thereby forming a 5 nm–20 nm thick sugar-carbon shell on the nanopore walls. A 10 wt%–20 wt% glucose solution provides sufficient carbon source, thereby increasing the carbon yield from 40% to ≥70%. Hydrothermal treatment at 170–190℃ for 4–6 hours allows the sugar-carbon shell to uniformly coat pearl-like carbon particles, thus increasing the specific surface area of ​​the carbon aerogel insulation layer 2 from 600 m² / h. 2 / g decreased to 300m 2 / g and reduce radiative heat transfer; pyrolysis at 800℃~1000℃ further increases the graphitization degree of the sugar carbon shell from 10% to 30%, thereby further reducing the thermal conductivity of the carbon aerogel insulation layer 2 from 0.08W / m / K to 0.03W / m / K; the sugar carbon shell simultaneously seals microcracks, thereby increasing the compressive strength of the carbon aerogel insulation layer 2 from 5MPa to 15MPa. The above-mentioned reinforcing chains enable the carbon aerogel insulation layer 2 to maintain a nanoporous framework at 1600℃, thereby further supporting claim 1's solution to "how to form a material in one step that combines 1600℃ ablation resistance, high-efficiency heat insulation, high shear strength, and density ≤0.65g / cm³". 3 The technical problem of "lightweight integrated thermal protection materials".

[0040] Examples of pH values: 2.0, 2.5, 3.0, 3.5, 4.0; Examples of glucose mass fraction values: 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%; Examples of sugar-carbon shell thickness values: 5nm, 7nm, 9nm, 11nm, 13nm, 15nm, 17nm, 19nm, 20nm; Examples of carbon yield values: 40%, 45%, 50%, 55%, 60%, 65%, 70%; Specific surface area. Examples of values: 600 m² / g, 550 m² / g, 500 m² / g, 450 m² / g, 400 m² / g, 350 m² / g, 300 m² / g; Examples of graphitization values: 10%, 15%, 20%, 25%, 30%; Examples of thermal conductivity values: 0.08 W / m / K, 0.07 W / m / K, 0.06 W / m / K, 0.05 W / m / K, 0.04 W / m / K, 0.03 W / m / K; Examples of compressive strength values: 5 MPa, 7 MPa, 9 MPa, 11 MPa, 13 MPa, 15 MPa.

[0041] In some embodiments, the dense surface layer 3 is formed by passing methyltrichlorosilane and hydrogen in a chemical vapor deposition furnace at a volume ratio of 1:3 to 5, and repeating the deposition-polishing-redeposition process 5 to 20 times at 1000°C to 1200°C until the mass change rate before and after polishing is ≤1%.

[0042] A volume ratio of methyltrichlorosilane to hydrogen of 1:3–5 ensures a Si / C ratio close to 1:1, thereby increasing the purity of deposited SiC to ≥99%. A deposition temperature of 1000℃–1200℃ maintains the β-phase crystal structure of SiC, thus locking the thermal expansion coefficient of the dense surface layer 3 at 4.5 × 10⁻⁶. -6 / K~5.5×10 -6 / K and match with ceramic layer 1; repeat deposition-polishing 5 to 20 times to eliminate surface pinholes layer by layer, thereby reducing the porosity of the surface dense layer 3 from 15% to ≤1%; the mass change rate before and after polishing is ≤1% to determine the dense endpoint, thereby reducing the oxygen permeability from 1×10 -5 g / cm 2 / s decreased to ≤1×10 -6 g / cm 2 / s; the dense SiC layer achieves a hardness of 25 GPa, thereby reducing the surface ablation retreat rate at 1600℃ from 0.10 mm / s to ≤0.05 mm / s. This densification closed-loop structure makes the surface dense layer 3 an antioxidant barrier, further supporting claim 1's solution to "how to form a material in one step that possesses 1600℃ ablation resistance, high thermal insulation, high shear strength, and a density ≤0.65 g / cm³". 3 The technical problem of "lightweight integrated thermal protection materials".

[0043] Examples of volume ratio values: 1:3, 1:3.5, 1:4, 1:4.5, 1:5; Examples of deposition temperatures: 1000℃, 1025℃, 1050℃, 1075℃, 1100℃, 1125℃, 1150℃, 1175℃, 1200℃; Examples of SiC purity values: 99wt%, 99.2wt%, 99.4wt%, 99.6wt%, 99.8wt%, 99.9wt%; Example of thermal expansion coefficient: 4.5×10⁻⁶ -6 / K, 4.7×10 -6 / K, 4.9×10 -6 / K, 5.1×10 -6 / K, 5.3×10 -6 / K, 5.5×10 -6 / K; Examples of deposition counts: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20; Examples of porosity counts: 15%, 12%, 9%, 6%, 3%, 1%; Examples of oxygen permeability counts: 1×10 -5 g / cm 2 / s, 5×10 -6 g / cm 2 / s, 1×10 -6 g / cm 2 / s, 5×10 -7 g / cm 2 / s, 1×10 -7 g / cm 2 / s; Hardness values: 25GPa, 26GPa, 27GPa, 28GPa, 29GPa, 30GPa; Ablation retreat rate values: 0.10mm / s, 0.09mm / s, 0.08mm / s, 0.07mm / s, 0.06mm / s, 0.05mm / s.

[0044] Secondly, this application provides a molding method for an integrated material resistant to ultra-high temperature and providing heat insulation, characterized in that the molding method includes, in sequence: a fiber skeleton preparation step, a skeleton pretreatment step, a ceramic layer 1 prepreg step, an aerogel heat insulation layer 2 introduction step, and a surface densification step. The fiber skeleton preparation step is as follows: lay up a needle-punched fiber preform or a three-dimensional braided fiber preform, wherein the fiber material of the preform is selected from at least one of carbon fiber, quartz fiber, mullite fiber, and alumina fiber. The pretreatment step of the fiber skeleton is as follows: the fiber skeleton is heated at 800℃~1000℃ under vacuum conditions, cooled in the furnace, and then immersed in ethanol or acetone for 6h~12h. Then it is dried at 60℃~70℃ for 6h~24h. The dried fiber skeleton is then placed in a chemical vapor deposition furnace and a carbon coating is deposited at 800℃~1200℃ using methane or acetylene as the reaction gas and hydrogen or argon as the carrier gas. The volume ratio of the reaction gas to the carrier gas is 1:3~5, and the flow rate of the reaction gas is 0.5L / min~1.2L / min. The fiber skeleton after carbon coating is then heated again at 800℃~1300℃ under vacuum to obtain a pre-tempered fiber skeleton. The pre-preparation steps for the ceramic layer 1 are as follows: Ultra-high temperature ceramic powder, ethanol, and dispersant are ball-milled at a mass ratio of 100:(20-50):(1-3) for 12-48 hours to obtain a ceramic slurry. The pre-tempered fiber skeleton is then impregnated with the ceramic slurry under a vacuum of 0.05 atm to 0.1 atm for 0.5-1 hours, followed by drying at 60-80℃ for 6-48 hours. This impregnation-drying process is repeated 2-5 times until the mass change rate after drying is ≤1%. The aerogel insulation layer 2 is introduced as follows: phenolic resin, solvent, and catalyst are mixed in a mass ratio of 50:(150-200):1 to form a sol. The fiber skeleton containing the ceramic layer 1 is impregnated with the sol under a vacuum of 0.2 atm to 0.3 atm and held under pressure for 10 min to 20 min. After flipping, it is impregnated and held under pressure again, and this process is repeated 2 to 3 times, with a total holding time of 1 h to 6 h. Subsequently, the impregnated fiber skeleton is placed in a high-pressure reaction vessel and gelled in stages by heating. After curing, solvent replacement, drying, and pyrolysis at 800℃ to 1000℃ are performed sequentially to obtain the carbon aerogel insulation layer 2. The surface densification step is as follows: the fiber skeleton containing the aerogel insulation layer 2 is placed in a chemical vapor deposition furnace, and after vacuuming, a mixed gas of methyltrichlorosilane and hydrogen in a volume ratio of 1:3 to 5 is introduced. Deposition is carried out at 1000℃ to 1200℃. After the initial deposition, the surface is polished and the deposition-polishing process is repeated 5 to 20 times until the mass change rate after polishing is ≤1%, thus forming the surface dense layer 3.

[0045] The fiber skeleton preparation step uses needle-punched fiber preforms or three-dimensional braided fiber preforms to provide a three-dimensional interlocking skeleton. The skeleton pretreatment step involves vacuum heating at 800℃~1000℃, immersion in ethanol or acetone, drying at 60℃~70℃, CVD carbon coating at 800℃~1200℃, and subsequent vacuum heating at 800℃~1300℃, thereby increasing the compressive strength of the fiber skeleton from 50MPa to 120MPa. The ceramic layer 1 pretreatment step involves vacuum impregnation of ZrB2 / HfB2 slurry at 0.05atm~0.1atm and then... The ceramic layer 1 is dried 2–5 times to reduce its porosity to 3%–8%. The aerogel insulation layer 2 is introduced by vacuum impregnation of phenolic resin sol at 0.2 atm–0.3 atm, followed by segmented heating for gel curing, solvent replacement, drying, and pyrolysis at 800℃–1000℃, thereby locking the thermal conductivity of the carbon aerogel insulation layer 2 to 0.03 W / m / K–0.08 W / m / K. The surface densification step involves CVDSiC deposition at 1000℃–1200℃ followed by repeated deposition-polishing 5–20 times, thereby reducing the oxygen permeability to ≤1×10⁻⁶. -6 g / cm 2 / s. The above five continuous processes are completed in the same furnace, thus ensuring that the product achieves the desired properties in one step: 1600℃ ablation resistance, high heat insulation, high shear strength, and density ≤0.65g / cm³. 3 The technical problem of "lightweight integrated thermal protection materials".

[0046] Examples of vacuum heating temperatures: 800℃, 825℃, 850℃, 875℃, 900℃, 925℃, 950℃, 975℃, 1000℃; Examples of immersion times: 6h, 7h, 8h, 9h, 10h, 11h, 12h; Examples of drying temperatures: 60℃, 61℃, 62℃, 63℃, 64℃, 65℃, 66℃, 67℃, 68℃, 69℃, 70℃; Examples of CVD carbon coating temperatures: 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃, 1100℃, 1150℃, 1200℃; Examples of re-vacuum heating temperatures: 800℃, 825℃... Temperature ranges for vacuum impregnation: 850℃, 875℃, 900℃, 925℃, 950℃, 975℃, 1000℃, 1025℃, 1050℃, 1075℃, 1100℃, 1125℃, 1150℃, 1175℃, 1200℃, 1225℃, 1250℃, 1275℃, 1300℃; Examples of vacuum impregnation pressure values: 0.05atm, 0.06atm, 0.07atm, 0.08atm, 0.09atm, 0.10atm; Examples of impregnation time values: 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1.0h; Drying temperatures: 60℃, 62℃, 64℃, 66℃, 68℃. Temperatures: 70℃, 72℃, 74℃, 76℃, 78℃, 80℃; Drying time examples: 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h, 48h; Number of repetitions examples: 2 times, 3 times, 4 times, 5 times; Vacuum impregnation pressure examples: 0.2atm, 0.22atm, 0.24atm, 0.26atm, 0.28atm, 0.3atm; Holding time examples: 10min, 12min, 14min, 16min Examples of total holding time values: 1h, 2h, 3h, 4h, 5h, 6h; Examples of pyrolysis temperature values: 800℃, 825℃, 850℃, 875℃, 900℃, 925℃, 950℃, 975℃, 1000℃; Examples of deposition temperature values: 1000℃, 1025℃, 1050℃, 1075℃, 1100℃, 1125℃, 1150℃, 1175℃, 1200℃; Examples of deposition-polishing cycles: 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, 11 times, 12 times, 13 times, 14 times, 15 times, 16 times, 17 times, 18 times, 19 times, 20 times.

[0047] In some embodiments, during the introduction of the aerogel insulation layer 2, the temperature-time sequence for the segmented heating and gel curing is as follows: 60℃~90℃ for 1h~2h, 100℃~120℃ for 1h~2h, 130℃~150℃ for 0.5h~1h, and 160℃~190℃ for 1h~2h.

[0048] Holding the phenolic resin sol at 60℃~90℃ for 1h~2h allows the low molecular weight components to volatilize uniformly, thereby locking the initial foam pore size to 10nm~30nm; holding it at 100℃~120℃ for 1h~2h initiates phenolic hydroxymethyl condensation, thereby increasing the gel crosslinking density from 0.4×10 -3 mol / cm 3 Increased to 0.8×10 -3 mol / cm 3 The process involves holding the material at 130℃~150℃ for 0.5h~1h to accelerate moisture removal, thereby reducing the shrinkage stress from 0.8MPa to 0.3MPa; then holding it at 160℃~190℃ for 1h~2h to complete the phenolic three-dimensional network shaping, thereby reducing the final shrinkage rate of the carbon aerogel insulation layer 2 from 25% to 8%. This four-stage stepped heating avoids rapid boiling that could lead to framework collapse, further ensuring that the carbon aerogel insulation layer 2 prepared by the method described in claim 8 has a low thermal conductivity of 0.03W / m / K~0.08W / m / K, ultimately supporting the goal of "how to achieve a one-step molding process that combines 1600℃ ablation resistance, high-efficiency thermal insulation, high shear strength, and a density ≤0.65g / cm³". 3 The technical problem of "lightweight integrated thermal protection materials".

[0049] Examples of temperature values ​​in the first segment: 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, 72℃, 74℃, 76℃, 78℃, 80℃, 82℃, 84℃, 86℃, 88℃, 90℃; Examples of time values ​​in the first segment: 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h; Examples of temperature values ​​in the second segment: 100℃, 102℃, 104℃, 106℃, 108℃, 110℃, 112℃, 114℃, 116℃, 118℃, 120℃; Second time period examples: 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h; Third time period examples: 130℃, 132℃, 134℃, 136℃, 138℃, 140℃, 142℃, 144℃. 146℃, 148℃, 150℃; Examples of third-time values: 0.5h, 0.55h, 0.6h, 0.65h, 0.7h, 0.75h, 0.8h, 0.85h, 0.9h, 0.95h, 1h; Examples of fourth-time temperature values: 160℃, 162℃, 164℃, 166℃, 168℃, 170℃, 172℃, 174℃, 176℃, 178℃, 180℃, 182℃, 18 4℃, 186℃, 188℃, 190℃; Fourth time values: 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h; Pore size values: 10nm, 12nm, 14nm, 16nm, 18nm, 20nm, 22nm, 24nm, 26nm, 28nm, 30nm; Crosslinking density value: 0.4×10 -3 mol / cm 3 0.5×10 -3 mol / cm 3 0.6×10 -3 mol / cm 3 0.7×10 -3 mol / cm 3 0.8×10 -3 mol / cm 3 Examples of shrinkage stress values: 0.8MPa, 0.7MPa, 0.6MPa, 0.5MPa, 0.4MPa, 0.3MPa; Examples of shrinkage rate values: 25%, 22%, 19%, 16%, 13%, 10%, 8%.

[0050] In some embodiments, the carbon aerogel insulation layer 2 is further immersed in a glucose solution with a pH of 2-4 and a mass fraction of 10wt%-20wt% after pyrolysis, and then hydrothermally heated at 170-190°C for 4-6 hours in a high-pressure reaction vessel, followed by drying at 60-80°C and secondary pyrolysis at 800-1000°C to form a sugar-carbon shell reinforced carbon aerogel insulation layer 2.

[0051] An acidic environment of pH 2–4 catalyzes the intramolecular etherification of glucose molecules, thereby generating a 5 nm–20 nm thick sugar-carbon shell layer on the surface of the carbon aerogel framework. A 10 wt%–20 wt% glucose solution ensures sufficient carbon source, thus increasing the carbon yield from 40% to ≥70%. Hydrothermal treatment at 170–190℃ for 4–6 hours allows the sugar-carbon shell layer to uniformly coat pearl-like carbon particles, thereby increasing the specific surface area of ​​the carbon aerogel insulation layer 2 from 600 m² / h. 2 / g decreased to 300m 2 / g and reduce radiative heat transfer; drying at 60℃~80℃ removes free water, thereby avoiding water vapor bursting pore structure during secondary pyrolysis; secondary pyrolysis at 800℃~1000℃ partially graphitizes the sugar carbon shell, thereby further reducing the thermal conductivity of the carbon aerogel insulation layer 2 from 0.08W / m / K to 0.03W / m / K; the sugar carbon shell simultaneously seals microcracks, thereby increasing the compressive strength of the carbon aerogel insulation layer 2 from 5MPa to 15MPa. The above post-treatment closed loop ensures that the carbon aerogel insulation layer 2 still maintains a nanoporous framework at 1600℃, thereby ultimately ensuring that the ultra-high temperature resistant heat insulation integrated material prepared by the method described in claim 8 satisfies the technical problem of "how to form a lightweight integrated thermal protection material with 1600℃ ablation resistance, high heat insulation efficiency, high shear strength and density ≤0.65g / cm³ in one step".

[0052] Examples of pH values: 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0; Examples of glucose mass fraction values: 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%; Examples of hydrothermal temperature values: 170, 175, 180, 185, 190℃; Examples of hydrothermal time values: 4h, 4.2h, 4.4h, 4.6h, 4.8h, 5h, 5.2h, 5.4h, 5.6h, 5.8h. 6h; Examples of drying temperatures: 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, 72℃, 74℃, 76℃, 78℃, 80℃; Examples of secondary pyrolysis temperatures: 800℃, 825℃, 850℃, 875℃, 900℃, 925℃, 950℃, 975℃, 1000℃; Examples of sugar-carbon shell thickness: 5nm, 7nm, 9nm, 11nm, 13nm, 15nm, 17nm, 19nm, 20nm; Examples of carbon yield: 40%, 45%, 50%, 55%, 60%, 65%, 70%; Example of specific surface area: 600m² 2 / g、550m 2 / g、500m 2 / g、450m 2 / g、400m 2 / g, 350m 2 / g、300m 2 / g; Examples of thermal conductivity values: 0.08W / m / K, 0.07W / m / K, 0.06W / m / K, 0.05W / m / K, 0.04W / m / K, 0.03W / m / K; Examples of compressive strength values: 5MPa, 7MPa, 9MPa, 11MPa, 13MPa, 15MPa.

[0053] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0054] Example 1 A molding method for an integrated ultra-high temperature resistant and heat-insulating material includes the following steps: Fiber skeleton preparation steps: lay up needle-punched fiber preforms, wherein the fiber material of the needle-punched fiber preforms is carbon fiber; The pretreatment steps for the skeleton are as follows: The needled fiber preform is heated to 800°C under vacuum, cooled in the furnace, and then immersed in ethanol for 6 hours, followed by drying at 60°C for 6 hours; the dried needled fiber preform is placed in a chemical vapor deposition furnace, and a carbon coating is deposited at 800°C using methane as the reactant gas and hydrogen as the carrier gas, with a reactant gas to carrier gas volume ratio of 1:3 and a reactant gas flow rate of 0.5 L / min; the needled fiber preform after carbon coating is deposited is heated again at 800°C under vacuum to obtain a pre-strengthened fiber skeleton; Pre-preparation steps for ceramic layer 1: ZrB2 ultra-high temperature ceramic powder, ethanol, and polyvinylpyrrolidone dispersant are ball-milled at a mass ratio of 100:20:1 for 12 hours to obtain a ceramic slurry; the pre-tempered fiber skeleton is impregnated with the ceramic slurry under a vacuum of 0.05 atm for 0.5 hours, and then dried at 60°C for 6 hours. The impregnation-drying process is repeated twice until the mass change rate after drying is ≤1%. Steps for introducing aerogel insulation layer 2: Phenolic resin, solvent, and catalyst are mixed in a mass ratio of 50:150:1 to form a sol; the pre-tempered fiber skeleton containing ceramic layer 1 is impregnated with the sol under a vacuum of 0.2 atm and held under pressure for 10 min, then flipped over and impregnated and held under pressure again, repeated twice, for a total holding time of 1 h; the impregnated pre-tempered fiber skeleton is placed in a high-pressure reaction vessel and gelled in stages by heating, and after curing, solvent replacement, drying, and pyrolysis at 800℃ are performed sequentially to obtain carbon aerogel insulation layer 2; the carbon aerogel insulation layer 2 is immersed in a 10% glucose solution with pH 2, then transferred to a high-pressure reaction vessel and heated to 180℃ and held for 4 h, then dried at 60℃ and pyrolyzed again at 800℃ to obtain sugar-carbon shell reinforced carbon aerogel insulation layer 2; Surface densification step: The pre-tempered fiber skeleton of the sugar-containing carbon shell reinforced carbon aerogel insulation layer 2 is placed in a chemical vapor deposition furnace. After vacuuming, a mixed gas of methyltrichlorosilane and hydrogen in a volume ratio of 1:3 is introduced and deposited at 1000℃. After the initial deposition, the surface is polished and the deposition-polishing process is repeated 5 times until the mass change rate after polishing is ≤1%, forming a dense surface layer 3; finally, an ultra-high temperature resistant heat insulation integrated material is obtained.

[0055] Example 2 A molding method for an integrated ultra-high temperature resistant and heat-insulating material includes the following steps: Fiber skeleton preparation steps: lay up a three-dimensional braided fiber preform, wherein the fiber material of the three-dimensional braided fiber preform is quartz fiber; The skeleton pretreatment steps are as follows: The three-dimensional braided fiber preform is heated to 900°C under vacuum, cooled in the furnace, and then immersed in acetone for 9 hours, followed by drying at 65°C for 15 hours; the dried three-dimensional braided fiber preform is placed in a chemical vapor deposition furnace, and a carbon coating is deposited at 1000°C using acetylene as the reaction gas and argon as the carrier gas, with a reaction gas to carrier gas volume ratio of 1:4 and a reaction gas flow rate of 0.8 L / min; the three-dimensional braided fiber preform after carbon coating is reheated at 1050°C under vacuum to obtain a pre-tempered fiber skeleton; Pre-preparation steps for ceramic layer 1: HfB2 ultra-high temperature ceramic powder, ethanol, and sodium polyacrylate dispersant were ball-milled at a mass ratio of 100:35:2 for 30 hours to obtain a ceramic slurry; the pre-tempered fiber skeleton was impregnated with the ceramic slurry under a vacuum of 0.075 atm for 0.75 hours, followed by drying at 70°C for 27 hours. This impregnation-drying process was repeated three times until the mass change rate after drying was ≤1%. Steps for introducing aerogel insulation layer 2: Phenolic resin, solvent, and catalyst are mixed in a mass ratio of 50:175:1 to form a sol; the pre-tempered fiber skeleton containing ceramic layer 1 is impregnated with the sol under a vacuum of 0.25 atm and held under pressure for 15 min, then flipped over and impregnated and held under pressure again, repeated twice, for a total holding time of 3.5 h; the impregnated pre-tempered fiber skeleton is placed in a high-pressure reaction vessel and gelled in stages by heating, and after curing, solvent replacement, drying, and pyrolysis at 900 °C are performed sequentially to obtain carbon aerogel insulation layer 2; the carbon aerogel insulation layer 2 is immersed in a pH 3, 15% glucose solution, and then transferred to a high-pressure reaction vessel and heated to 180 °C for 5 h, and then dried at 70 °C and pyrolyzed again at 900 °C to obtain sugar-carbon shell reinforced carbon aerogel insulation layer 2; Surface densification step: The pre-tempered fiber skeleton of the sugar-containing carbon shell reinforced carbon aerogel insulation layer 2 is placed in a chemical vapor deposition furnace. After vacuuming, a mixed gas of methyltrichlorosilane and hydrogen in a volume ratio of 1:4 is introduced and deposited at 1100℃. After the initial deposition, the surface is polished and the deposition-polishing process is repeated 12 times until the mass change rate after polishing is ≤1%, forming a dense surface layer 3; finally, an ultra-high temperature resistant heat insulation integrated material is obtained.

[0056] Example 3 A molding method for an integrated ultra-high temperature resistant and heat-insulating material includes the following steps: Fiber skeleton preparation steps: lay up needle-punched fiber preforms, wherein the fiber material of the needle-punched fiber preforms is alumina fiber; The pretreatment steps for the skeleton are as follows: The needled fiber preform is heated to 1000°C under vacuum, cooled in the furnace, and then immersed in ethanol for 12 hours, followed by drying at 70°C for 24 hours; the dried needled fiber preform is placed in a chemical vapor deposition furnace, and a carbon coating is deposited at 1200°C using methane as the reactant gas and helium as the carrier gas, with a reactant gas to carrier gas volume ratio of 1:5 and a reactant gas flow rate of 1.2 L / min; the needled fiber preform after carbon coating is deposited is heated again at 1300°C under vacuum to obtain a pre-strengthened fiber skeleton; Pre-preparation steps for ceramic layer 1: ZrB2 and HfB2 mixed ultra-high temperature ceramic powder, ethanol, and sodium hexametaphosphate dispersant were ball-milled at a mass ratio of 100:50:3 for 48 hours to obtain a ceramic slurry; the pre-tempered fiber skeleton was impregnated with the ceramic slurry under a vacuum of 0.1 atm for 1 hour, followed by drying at 80℃ for 48 hours. This impregnation-drying process was repeated 5 times until the mass change rate after drying was ≤1%. Steps for introducing aerogel insulation layer 2: Phenolic resin, solvent, and catalyst are mixed in a mass ratio of 50:200:1 to form a sol; the pre-tempered fiber skeleton containing ceramic layer 1 is impregnated with the sol under a vacuum of 0.3 atm and held under pressure for 20 min, then flipped over and impregnated and held under pressure again, repeated 3 times, with a total holding time of 6 h; the impregnated pre-tempered fiber skeleton is placed in a high-pressure reaction vessel and gelled in stages by heating, and after curing, solvent replacement, drying, and pyrolysis at 1000℃ are performed sequentially to obtain carbon aerogel insulation layer 2; the carbon aerogel insulation layer 2 is immersed in a pH 4, 20% glucose solution, and then transferred to a high-pressure reaction vessel and heated to 180℃ and held for 6 h, and then dried at 80℃ and pyrolyzed again at 1000℃ to obtain sugar-carbon shell reinforced carbon aerogel insulation layer 2; Surface densification step: The pre-tempered fiber skeleton of the sugar-containing carbon shell reinforced carbon aerogel insulation layer 2 is placed in a chemical vapor deposition furnace. After vacuuming, a mixed gas of methyltrichlorosilane and hydrogen in a volume ratio of 1:5 is introduced and deposited at 1200℃. After the initial deposition, the surface is polished and the deposition-polishing process is repeated 20 times until the mass change rate after polishing is ≤1%, forming a dense surface layer 3; finally, an ultra-high temperature resistant heat insulation integrated material is obtained.

[0057] Comparative Example 1 (vacuum heating again without pre-tempered fiber skeleton) A molding method for an integrated ultra-high temperature resistant and heat-insulating material includes the following steps: Fiber skeleton preparation steps: lay up needle-punched fiber preforms, wherein the fiber material of the needle-punched fiber preforms is carbon fiber; The skeleton pretreatment steps are as follows: The needled fiber preform is heated to 800°C under vacuum conditions, cooled in the furnace, and then immersed in ethanol for 6 hours, followed by drying at 60°C for 6 hours; the dried needled fiber preform is placed in a chemical vapor deposition furnace, and a carbon coating is deposited at 800°C using methane as the reaction gas and hydrogen as the carrier gas, with a reaction gas to carrier gas volume ratio of 1:3 and a reaction gas flow rate of 0.5 L / min; the needled fiber preform after carbon coating deposition does not undergo vacuum heating again, and the unstrengthened fiber skeleton is obtained directly. The pre-preparation steps of ceramic layer 1, the introduction steps of aerogel insulation layer 2, and the surface densification steps are exactly the same as those in Example 1.

[0058] Comparative Example 2 (Deleted Sugar Carbon Shell Reinforcement Step) A molding method for an integrated ultra-high temperature resistant and heat-insulating material includes the following steps: The fiber skeleton preparation steps, skeleton pretreatment steps, and ceramic layer 1 prepreg preparation steps are exactly the same as in Example 2; Steps for introducing aerogel insulation layer 2: Phenolic resin, solvent, and catalyst are mixed in a mass ratio of 50:175:1 to form a sol; the pre-tempered fiber skeleton containing ceramic layer 1 is impregnated with the sol under a vacuum of 0.25 atm and held under pressure for 15 min, then flipped over and impregnated and held under pressure again, repeated twice, for a total holding time of 3.5 h; the impregnated pre-tempered fiber skeleton is placed in a high-pressure reaction vessel and gelled in stages by heating; after curing, solvent replacement, drying, and pyrolysis at 900℃ are performed sequentially to obtain carbon aerogel insulation layer 2; the carbon aerogel insulation layer 2 is directly used as sugar-free carbon shell carbon aerogel insulation layer 2 without undergoing hydrothermal carbon coating with glucose solution and secondary pyrolysis, and enters subsequent steps. The surface densification steps are exactly the same as in Example 2.

[0059] Comparative Example 3 (Missing surface densification step) A molding method for an integrated ultra-high temperature resistant and heat-insulating material includes the following steps: The fiber skeleton preparation steps, skeleton pretreatment steps, ceramic layer 1 prepreg steps, and aerogel insulation layer 2 introduction steps are exactly the same as in Example 3; The ultra-high temperature resistant heat insulation integrated material does not undergo a surface densification step, and directly uses the sugar-containing carbon shell layer reinforced carbon aerogel heat insulation layer 2 as the final material.

[0060] Experimental methods for evaluating results: 1. In-plane tensile strength determination The dense layer of the obtained ultra-high temperature resistant heat insulation integrated material was processed into a 120mm×10mm×2mm sample. Tensile properties were tested on it using a universal testing machine with a loading rate of 1mm / min. The maximum load was recorded and the tensile strength was calculated.

[0061] 2. Thermal shock test The obtained ultra-high temperature resistant heat insulation integrated material was placed on a mechanical vibration platform for thermal vibration testing. The test temperature was adjusted to 2000℃, and broadband random vibration with a vibration frequency of 500-2000Hz was performed for 300s. The material was then observed for any damage.

[0062] 3. 2500℃ ablation resistance test The obtained ultra-high temperature resistant heat insulation integrated material was processed into a φ30mm×10mm circular piece, placed in an oxy-acetylene flame, and the surface temperature of the sample was controlled at 2500℃. The sample was continuously ablated for 300s, the ablation depth in the thickness direction was measured, and the linear ablation rate was calculated.

[0063]

[0064] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A high-temperature resistant, heat-insulating integrated material, characterized in that, include: Fiber skeleton, ceramic layer, aerogel insulation layer and dense surface layer; The fiber skeleton is a needle-punched fiber preform or a three-dimensional woven fiber preform, and the fiber material of the fiber skeleton is selected from at least one of carbon fiber, quartz fiber, mullite fiber and alumina fiber. The ceramic layer is a layer formed by vacuum impregnation and drying of ultra-high temperature ceramic powder, wherein the ultra-high temperature ceramic powder is selected from at least one of ZrB2 and HfB2. The aerogel insulation layer is a carbon aerogel layer; The surface dense layer is a dense layer formed by chemical vapor deposition of SiC. A fiber cloth isolation layer is provided between the ceramic layer and the aerogel insulation layer. The material of the fiber cloth isolation layer may be the same as or different from the fiber material of the fiber skeleton.

2. The ultra-high temperature resistant and heat-insulating integrated material according to claim 1, characterized in that, Before forming the ceramic layer, the fiber skeleton undergoes vacuum heating pretreatment, organic solvent immersion treatment, drying treatment, chemical vapor deposition carbon coating treatment, and vacuum heating pre-tempering treatment in sequence.

3. The ultra-high temperature resistant and heat-insulating integrated material according to claim 1, characterized in that, The ceramic layer is formed by immersing the fiber skeleton in a ceramic slurry under a vacuum of 0.05 atm to 0.1 atm and then repeatedly drying it 2 to 5 times.

4. The ultra-high temperature resistant and heat-insulating integrated material according to claim 1, characterized in that, The ceramic slurry is prepared by ball milling ultra-high temperature ceramic powder, ethanol and dispersant at a mass ratio of 100:(20-50):(1-3) for 12-48 hours.

5. The ultra-high temperature resistant and heat-insulating integrated material according to claim 1, characterized in that, The aerogel insulation layer is formed by vacuum impregnating the fiber skeleton with phenolic resin sol, followed by segmented heating and gel curing, solvent replacement, drying, and pyrolysis at 800℃~1000℃; the phenolic resin sol is prepared by mixing phenolic resin, solvent, and catalyst in a mass ratio of 50:(150~200):

1.

6. The ultra-high temperature resistant and heat-insulating integrated material according to claim 4, characterized in that, After pyrolysis, the carbon aerogel layer is further hydrothermally coated with a glucose solution of pH 2-4 and mass fraction 10wt%-20wt% and then pyrolyzed again at 800℃-1000℃ to form a sugar-carbon shell reinforced carbon aerogel insulation layer.

7. The ultra-high temperature resistant and heat-insulating integrated material according to claim 1, characterized in that, The dense surface layer is formed by passing methyltrichlorosilane and hydrogen in a chemical vapor deposition furnace at a volume ratio of 1:3 to 5, and repeating the deposition-polishing-redeposition process 5 to 20 times at 1000℃ to 1200℃, until the mass change rate before and after polishing is ≤1%.

8. A molding method for an integrated ultra-high temperature resistant and heat-insulating material, characterized in that, The molding method includes, in sequence: fiber skeleton preparation step, skeleton pretreatment step, ceramic layer prepreg preparation step, aerogel insulation layer introduction step, and surface densification step. The fiber skeleton preparation step is as follows: lay up a needle-punched fiber preform or a three-dimensional braided fiber preform, wherein the fiber material of the preform is selected from at least one of carbon fiber, quartz fiber, mullite fiber, and alumina fiber. The pretreatment step of the fiber skeleton is as follows: the fiber skeleton is heated at 800℃~1000℃ under vacuum conditions, cooled in the furnace, and then immersed in ethanol or acetone for 6h~12h. Then it is dried at 60℃~70℃ for 6h~24h. The dried fiber skeleton is then placed in a chemical vapor deposition furnace and a carbon coating is deposited at 800℃~1200℃ using methane or acetylene as the reaction gas and hydrogen or argon as the carrier gas. The volume ratio of the reaction gas to the carrier gas is 1:3~5, and the flow rate of the reaction gas is 0.5L / min~1.2L / min. The fiber skeleton after carbon coating is then heated again at 800℃~1300℃ under vacuum to obtain a pre-tempered fiber skeleton. The pre-preparation steps of the ceramic layer are as follows: ultra-high temperature ceramic powder, ethanol and dispersant are ball-milled at a mass ratio of 100:(20-50):(1-3) for 12-48 hours to obtain a ceramic slurry. The pre-tempered fiber skeleton is impregnated with the ceramic slurry under a vacuum of 0.05 atm to 0.1 atm for 0.5-1 hours, and then dried at 60-80℃ for 6-48 hours. The impregnation-drying process is repeated 2-5 times until the mass change rate after drying is ≤1%. The aerogel insulation layer introduction step is as follows: Phenolic resin, solvent, and catalyst are prepared into a sol at a mass ratio of 50:(150~200):

1. The fiber skeleton containing the ceramic layer is impregnated with the sol under a vacuum of 0.2atm~0.3atm and held under pressure for 10min~20min. After flipping, it is impregnated and held under pressure again, and this process is repeated 2~3 times, with a total holding time of 1h~6h. Subsequently, the impregnated fiber skeleton is placed in a high-pressure reaction vessel and gelled in stages by raising the temperature. After curing, solvent replacement, drying, and pyrolysis at 800℃~1000℃ are performed in sequence to obtain the carbon aerogel insulation layer. The surface densification step is as follows: the fiber skeleton containing the aerogel insulation layer is placed in a chemical vapor deposition furnace, and after vacuuming, a mixed gas of methyltrichlorosilane and hydrogen in a volume ratio of 1:3 to 5 is introduced. Deposition is carried out at 1000℃ to 1200℃. After the initial deposition, the surface is polished and the deposition-polishing process is repeated 5 to 20 times until the mass change rate after polishing is ≤1%, thus forming a dense surface layer.

9. The molding method according to claim 8, characterized in that, In the step of introducing the aerogel insulation layer, the temperature-time sequence for the segmented heating gel curing is as follows: 60℃~90℃ for 1h~2h, 100℃~120℃ for 1h~2h, 130℃~150℃ for 0.5h~1h, and 160℃~190℃ for 1h~2h.

10. The molding method according to claim 8, characterized in that, After pyrolysis, the carbon aerogel insulation layer is further immersed in a glucose solution with a pH of 2-4 and a mass fraction of 10wt%-20wt%. Then, it is hydrothermally heated at 170-190℃ for 4-6 hours in a high-pressure reaction vessel, followed by drying at 60℃-80℃ and secondary pyrolysis at 800℃-1000℃ to form a sugar-carbon shell-reinforced carbon aerogel insulation layer.

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