Ablation-resistant efficient thermal insulation integrated thermal protection structure and preparation method thereof

Abstract

The invention relates to an ablation-resistant efficient thermal insulation integrated thermal protection structure and a preparation method thereof.The preparation method of the ablation-resistant efficient thermal insulation integrated thermal protection structure comprises the steps that a thermal insulation fiber material is processed to obtain a thermal insulation layer with a clamping structure on the surface; mixing the ablation-resistant fiber and the ablation-resistant resin to obtain an ablation-resistant bulk molding compound; the ablation-resistant bulk molding compound is filled into the surface, with the clamping structure, of the heat insulation layer and is pre-compacted, so that the ablation-resistant bulk molding compound and the clamping structure on the surface of the heat insulation layer are embedded and hooked to form an integrated blank; and integral vacuum hot pressing is conducted on the integrated blank, so that the ablation-resistant bulk molding compound forms an ablation-resistant layer on the surface of the thermal insulation layer, and the integrated thermal protection structure is obtained. The technical problems that in the prior art, thermal insulation layers and ablation-resistant layers need to be independently manufactured and then assembled, the thermal insulation layers are prone to layering, and finally the thermal protection structure loses efficacy are solved.

Description

Technical Field

[0001] This application relates to the field of spacecraft thermal protection structures, and in particular to an ablation-resistant, high-efficiency, integrated thermal protection structure and its preparation method. Background Technology

[0002] In high-temperature environments such as spacecraft and high-speed aircraft, thermal protection structures are typically required for the fabrication of the aircraft's outer shell. The core design principle of these structures is to reliably meet thermal insulation requirements, ensuring the safe operation of the aircraft under extreme temperature conditions. With the rapid development of aerospace technology, thermal protection structures are increasingly evolving towards higher temperature resistance and longer operating times. This trend places unprecedented demands on the ablation resistance and thermal insulation performance of these structures.

[0003] Currently, existing low-density integrated thermal insulation materials suffer from insufficient ablation resistance. To improve this resistance, an ablation-resistant layer is typically added to the surface of the insulation layer. While the traditional assembly of the insulation and ablation-resistant layers provides a basic level of protection, in practice, it requires separate fabrication of the insulation and ablation-resistant layers before splicing the ablation-resistant layer onto the insulation surface. This assembly process is difficult and time-consuming. Furthermore, because the insulation and ablation-resistant layers possess different thermophysical properties, they are prone to delamination under prolonged high-temperature conditions, ultimately leading to the failure of the thermal protection structure and severely limiting the durability of thermal protection effectiveness. Summary of the Invention

[0004] This application provides a method for preparing an integrated thermal protection structure with high efficiency and ablation resistance, in order to solve the technical problems in related technologies where the insulation layer and the ablation-resistant layer need to be made separately before assembly, and the insulation layer is prone to delamination, which ultimately leads to the failure of the thermal protection structure.

[0005] In a first aspect, a method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure is provided, characterized in that it comprises: The heat-insulating fiber material is processed to obtain a heat-insulating layer with a snap-fit ​​structure on the surface; Ablative fibers and ablative resins are mixed to obtain ablative bulk molding compound; The ablation-resistant bulk molding compound is filled onto the surface of the insulation layer with a snap-fit ​​structure and pre-compacted so that the ablation-resistant bulk molding compound and the snap-fit ​​structure on the surface of the insulation layer are interlocked to form an integrated blank. The integral blank is vacuum hot-pressed to form an ablation-resistant layer on the surface of the heat insulation layer, resulting in an integrated thermal protection structure.

[0006] In conjunction with the first aspect, in one embodiment, the heat-insulating fiber material is processed to obtain a heat-insulating layer with a snap-fit ​​structure on its surface, comprising the following steps: The heat-insulating fiber material is dried and impurities are removed to obtain a dry fabric; The dried fabric is laid into the mold and pre-pressed in sequence, and then removable material is embedded in the surface of the dried fabric. The insulating resin is poured into the mold, avoiding removable materials, to fully impregnate the dry fabric and obtain an insulating preform. After the heat insulation preform is cured, it is dried at room temperature, and the removable material is removed to form a root structure on the surface to form a snap-fit ​​structure, thus obtaining a heat insulation layer with a snap-fit ​​structure on the surface.

[0007] In conjunction with the first aspect, in one embodiment, the removable material includes soluble salts.

[0008] In conjunction with the first aspect, in one embodiment, the heat-insulating fiber material is processed to obtain a heat-insulating layer with a snap-fit ​​structure on its surface, comprising the following steps: The heat-insulating fiber material is dried and impurities are removed to obtain a dry fabric; The dried fabric is laid into the mold for pre-compression; Heat insulation resin is poured into the mold until the heat insulation resin fully impregnates the dry fabric at the lower first thickness portion, and leaves the upper second thickness portion, so that the upper second thickness portion forms a hair structure, and a heat insulation preform is obtained. After curing the heat insulation preform, it is dried at room temperature to allow the hair structure to form a snap-fit ​​structure, resulting in a heat insulation layer with a snap-fit ​​structure on the surface.

[0009] In conjunction with the first aspect, in one embodiment, an integrated thermal protection structure is obtained by integrally vacuum hot pressing an integrated blank, comprising: Place the integrated blank into a vacuum bag and vacuum it; The vacuum-sealed integral blank is placed into an autoclave and cured in a stepwise manner with gradually increasing temperature. After curing, demolding yields an integrated thermal protection structure.

[0010] In conjunction with the first aspect, in one embodiment, the vacuum-sealed integral blank is placed into an autoclave and subjected to step-curing, which includes: The vacuum-sealed, one-piece blank is then placed into an autoclave: First, a first-time curing process is performed at a first-time preset temperature within a first-time preset period. The first-time preset period and the first-time preset temperature are determined based on the curing requirements of the ablation-resistant bulk molding compound. Then, a second curing process is carried out at a second preset temperature within a second preset time. The second preset temperature is higher than the first preset temperature. The second preset temperature is determined according to the curing requirements of the ablation-resistant bulk molding compound. Finally, the material is cured three times at a third preset temperature within a third preset time period. The third preset temperature is higher than the second preset temperature. The third preset temperature is determined based on the curing requirements of the ablation-resistant bulk molding compound.

[0011] In conjunction with the first aspect, in one embodiment, the heat-insulating fiber material includes quartz needle-punched felt, the ablation-resistant fiber includes alumina ceramic fiber, and the ablation-resistant resin includes boron phenolic resin.

[0012] In conjunction with the first aspect, in one embodiment, the density of the insulation layer is between 0.4 g / cm³. 3 ~0.8g / cm 3 Between these values, the thermal conductivity is less than 0.1 W / (mK).

[0013] In conjunction with the first aspect, in one embodiment, the ablation-resistant layer has a thermal resistance temperature exceeding 2000°C.

[0014] Secondly, a method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure is provided: It is prepared using the above-mentioned method for manufacturing an ablation-resistant, high-efficiency, integrated thermal protection structure, which includes: The heat insulation layer has a snap-fit ​​structure on its surface; In addition, an ablation-resistant layer is disposed on the side of the heat insulation layer that has a snap-fit ​​structure, and the ablation-resistant layer is integrally formed with the heat insulation layer.

[0015] The beneficial effects of the technical solution provided in this application include: during the preparation of the heat insulation layer, an irregular shape design is performed on the surface of the heat insulation layer to obtain a heat insulation layer with a snap-fit ​​structure; then, ablation-resistant bulk molding compound is filled into the snap-fit ​​structure of the heat insulation layer and integrated compaction vacuum hot pressing is performed, thereby enabling the heat insulation layer and the ablation-resistant layer to be integrally manufactured, simplifying the assembly process. Furthermore, through the snap-fit ​​structure on the surface of the heat insulation layer, a mechanical interlock is formed between the heat insulation layer and the ablation-resistant layer, improving the tightness of the fit between the heat insulation layer and the ablation-resistant layer, realizing the organic combination of the interface between the ablation-resistant layer and the heat insulation layer, and reducing the possibility of delamination during long-term use in high-temperature environments, leading to failure of the thermal protection structure.

[0016] This application provides a method for preparing an integrated thermal protection structure with high efficiency and ablation resistance. Since the insulation layer and the ablation-resistant layer are integrally manufactured and the interlocking structure is used to improve the fit, the possibility of delamination during long-term use in high-temperature environments leading to failure of the thermal protection structure is reduced. This solves the technical problem in related technologies where the insulation layer and the ablation-resistant layer need to be manufactured separately and then assembled, and delamination between the insulation layers is easy to occur, ultimately leading to failure of the thermal protection structure. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the integrated thermal protection structure provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the heat insulation layer provided in the embodiments of this application; In the diagram: 1. Insulation layer; 11. Snap-fit ​​structure; 2. Erosion resistant layer. Detailed Implementation

[0019] 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.

[0020] This application provides an integrated thermal protection structure with high efficiency and ablation resistance and a method for its preparation. It can solve the technical problems in related technologies where the insulation layer and the ablation-resistant layer need to be made separately and then assembled, and the insulation layer is prone to delamination, which ultimately leads to the failure of the thermal protection structure.

[0021] For ease of understanding, this application describes a finished ablation-resistant, high-efficiency, integrated thermal protection structure, referring to... Figure 1 A detailed structural diagram of an ablation-resistant, high-efficiency, integrated thermal protection structure, and the specific steps of its fabrication method are as follows: S1: The heat insulation fiber material is processed to obtain a heat insulation layer 1 with a snap-fit ​​structure 11 on the surface; In one embodiment of this application, the specific steps include: S101(a): Drying and removing impurities from the heat insulation fiber material to obtain a dry fabric; Specifically, quartz needle-punched felt can be selected as the thermal insulation fiber material, as it possesses excellent high-temperature thermal insulation performance, including maintaining structural stability under high-temperature conditions, effectively inhibiting heat conduction paths, and exhibiting excellent chemical inertness and long-term thermal aging resistance. Therefore, using quartz needle-punched felt as the thermal insulation fiber material for the processing of thermal insulation layer 1 can significantly improve the thermal resistance performance and environmental adaptability of thermal insulation layer 1.

[0022] When quartz needle-punched felt is selected as the heat insulation fiber material, it is placed in an oven at 80℃~120℃ and dried for 2~4 hours to remove moisture and impurities from the fibers and obtain a dry fabric.

[0023] In addition, depending on the actual application requirements, the optional thermal insulation fiber materials also include glass fiber, asbestos fiber and aluminum silicate fiber. These materials all have good thermal insulation properties and can provide flexible solutions for different temperature ranges, corrosive environments or cost constraints, ensuring that the thermal insulation layer 1 achieves efficient thermal management under complex working conditions. When selecting different thermal insulation fiber materials, the specific drying temperature and drying time also need to be flexibly changed according to their own chemical properties.

[0024] S102(a): The dried fabric is laid into the mold and pre-pressed in sequence, and a removable material is embedded in the surface of the dried fabric; The dried fabric is laid into the test mold, and the mold is closed to pre-compress the fabric. The specific size of the test mold is selected according to the actual production requirements. After pre-compression, removable material is embedded in the surface of the dried fabric.

[0025] More specifically, in one embodiment of this application, the removable material is specifically selected from soluble salts. When selecting a soluble salt, its solubility, chemical stability, particle morphology, and removal efficiency must be comprehensively considered. Sodium chloride is a commonly used choice due to its excellent water solubility and chemical inertness. Its regular crystal structure makes it easy to sieve and control particle size. Its aqueous solution is neutral and it does not easily react with resin systems or fibers. It can be completely removed by washing with room temperature water without significant residue. Sodium sulfate also exhibits good water solubility, which increases significantly with increasing temperature. Dissolution efficiency can be optimized by adjusting the water temperature. Sodium sulfate is chemically stable and does not readily absorb moisture in dry environments, maintaining the integrity of the embedded structure. However, its aqueous solution is slightly alkaline, requiring assessment of its compatibility with subsequent insulation resins. Potassium chloride, as a substitute for sodium chloride, has slightly higher solubility and lower hygroscopicity, making it particularly suitable for systems sensitive to sodium ions. Its removal method is similar to that of sodium chloride, but potassium ions may have a smaller impact on certain ecological environments. Sodium bicarbonate decomposes upon heating or exposure to acid, releasing carbon dioxide. It can be used to create special porous structures, but it maintains good stability under neutral conditions and requires removal through water washing or a weak acid solution. Potassium nitrate's solubility is sensitive to temperature changes, making it suitable for applications requiring rapid dissolution. However, due to its oxidizing properties, contact with reducing components should be avoided to prevent side reactions.

[0026] Furthermore, when pre-embedding removable materials, attention must be paid to the crystal morphology and particle size distribution of soluble salts, as this directly affects the precision and consistency of the snap-fit ​​structure 11 on the insulation layer 1 after the removable material is removed. Simultaneously, environmental factors must be considered, prioritizing low-toxicity, readily biodegradable salts to reduce wastewater treatment burden. The final selection must be based on the specific resin system used later, the type of fiber fabric used earlier, and the process conditions during processing, ensuring that the soluble salts remain inert during the pre-embedding stage and leave no ionic residue after removal, thus avoiding any impact on the long-term performance of the insulation layer 1.

[0027] S103(a): Low-density resin is poured into a mold, and the dry fabric is fully impregnated, avoiding removable materials, to obtain an insulating preform; Specifically, the RTM process is used to inject low-density resin into the mold cavity, so that the heat insulation resin can fully impregnate the dry fabric while avoiding removable materials. This allows natural root channels to form on the surface of the dry fabric after the removable materials are removed, thus forming the snap-fit ​​structure 11.

[0028] RTM (Resin Transfer Molding) is an advanced closed-mold molding technology. Its basic principle involves injecting liquid resin into a sealed mold cavity containing pre-reinforcing material (such as the dry fabric in this application) using a precise pressure injection system. Under pressure, the injected insulating resin fully penetrates the fiber network of the dry fabric, effectively eliminating air bubbles and ensuring uniform impregnation. Subsequently, it is cured under controlled conditions via heat or chemical methods to form a high-precision, high-density composite material component. RTM not only significantly improves the interfacial bonding strength between the insulating resin and the dry fabric but also avoids defects such as air bubbles and dry spots found in traditional manual layup processes, ensuring the dimensional stability and mechanical properties of the insulating layer 1.

[0029] In this embodiment, the matrix of the thermal insulation resin is specifically selected as phenolic aerogel material. This material, based on a phenolic resin system, exhibits excellent high-temperature resistance, superior flame retardant properties, high chemical inertness, and long-term thermal stability after special aerogelation treatment. Its unique microporous network structure can effectively inhibit heat conduction paths, while its chemical properties enable it to effectively resist the erosion of various media in high-temperature, corrosive, or oxidizing environments, maintaining structural integrity and providing reliable thermal management capabilities for the thermal insulation layer 1.

[0030] In other embodiments, the insulating resin may also be selected from silicone resins or silica sols. Silicone resins, based on their unique silicon-oxygen bond structure, exhibit excellent thermal oxidation stability, superior chemical inertness, and long-term weather resistance, effectively resisting oxidative decomposition and thermal degradation processes in high-temperature environments while maintaining good flexibility and interfacial adhesion. Silica sols, existing in the form of high-purity silica colloids, possess excellent thermal conversion characteristics and chemical stability. They can rapidly form a dense silica network structure under high-temperature conditions, providing a highly efficient thermal barrier, while also exhibiting excellent acid and alkali resistance, corrosion resistance, and environmental adaptability, ensuring the maintenance of the material's structural integrity and thermal insulation performance under complex thermal conditions.

[0031] When avoiding removable materials, a baffle can be installed at the location where removable materials are pre-embedded to reduce the possibility that the heat insulation resin will cover the removable materials at the same time when impregnating the dry fabric.

[0032] S104(a): After curing the heat insulation preform, it is dried at room temperature, and the removable material is removed to form a root structure on the surface to form a snap-fit ​​structure 11, thereby obtaining a heat insulation layer 1 with a snap-fit ​​structure 11 on the surface.

[0033] Taking the embodiments of this application as an example, the heat insulation layer 1 in this application is specifically a quartz needle-punched felt reinforced phenolic aerogel material. When curing the heat insulation preform, the mold containing the heat insulation preform is placed in an oven at about 100℃~120℃ for 24 hours to allow the phenolic aerogel to undergo a sol-gel reaction to complete the curing.

[0034] The cured composite material is then removed and dried at room temperature and pressure for 48-72 hours to allow the internal solvent to evaporate. Finally, the removable material on the surface is removed by washing or chiseling, resulting in a natural root structure on the surface of the insulation layer 1, forming an interlocking structure 11, thus obtaining an insulation layer 1 with the interlocking structure 11 on its surface. When the ablation-resistant bulk molding compound is subsequently filled onto the insulation layer 1, the ablation-resistant bulk molding compound can be fully impregnated into the root channels, forming a mechanically interlocked interface layer, thereby improving the fit between the insulation layer 1 and the ablation-resistant layer 2.

[0035] Among them, the quartz needle-punched felt reinforced phenolic aerogel material, which serves as the heat insulation layer 1, has a density of 0.6 g / cm³. 3 The thermal conductivity is 0.03 W / (mK), which fully meets the thermal insulation requirements of the aircraft for thermal insulation layer 1.

[0036] In other embodiments, the curing temperature, curing time, and drying conditions are varied according to the actual selected heat-insulating fiber material and heat-insulating resin, so that the final heat-insulating layer 1 has a nanoporous structure and a density between 0.4 g / cm³. 3 ~0.8g / cm 3 Between these parameters, a thermal conductivity of less than 0.1 W / (mK) is sufficient to meet the thermal insulation requirements of the aircraft for thermal insulation layer 1.

[0037] In another embodiment of this application, it specifically includes the following steps: S101(b): Drying and removing impurities from the heat insulation fiber material to obtain a dry fabric; S102(b): The dried fabric is laid into the mold for pre-compression; In this embodiment, there is no need to pre-embed additional removable material after pre-compression; pre-compression can be performed directly after laying.

[0038] S103(b): Inject the heat-insulating resin into the mold until the heat-insulating resin fully impregnates the dry fabric at the lower first thickness portion and leaves the upper second thickness portion, so that the upper second thickness portion forms a hair structure and a heat-insulating preform is obtained. For example, if the total thickness of the dried fabric is 10cm, during impregnation, the first thickness is selected as the bottom 8cm. The dried fabric within the first thickness is impregnated with heat-insulating resin, and the top 2cm is reserved as the second thickness so that the fibers of the second thickness of the dried fabric can form a natural hair structure, ultimately forming the snap-fit ​​structure 11.

[0039] S104(b): After curing the heat insulation preform, it is dried at room temperature to form a snap-fit ​​structure 11 with the hair structure, thus obtaining a heat insulation layer 1 with the snap-fit ​​structure 11 on the surface.

[0040] When the ablation-resistant bulk molding compound is subsequently filled onto the heat insulation layer 1, the ablation-resistant bulk molding compound can fully wrap around the hair structure and impregnate the dry fabric to a second thickness, so that a portion of the heat insulation layer 1 is embedded in the ablation-resistant bulk molding compound, thereby improving the mechanical interlocking performance between the ablation-resistant layer 2 and the heat insulation layer 1. Compared with the above embodiment, this embodiment does not require additional removable material and eliminates the additional removal step, but it will relatively reduce the thickness of the heat insulation layer 1. Therefore, a flexible selection between the two implementation methods is required based on the actual aircraft application requirements.

[0041] S2: Ablative resistant fiber and ablative resistant resin-based composite material are mixed to obtain ablative resistant bulk molding compound; More specifically, a kneader can be used to thoroughly mix ablation-resistant fibers and ablation-resistant resin to obtain ablation-resistant bulk molding compound.

[0042] In this embodiment, the ablation-resistant fiber is specifically selected from alumina ceramic fibers. These fibers exhibit excellent oxidation resistance and structural stability even under extreme high-temperature ablation environments, effectively resisting molten material erosion and thermal shock while maintaining excellent thermal shock resistance and low thermal expansion characteristics, ensuring the aircraft maintains material integrity under continuous high-temperature conditions. The ablation-resistant resin is selected from boron phenolic resin. Its unique chemical properties enable it to intelligently form a dense carbonized protective layer during high-temperature ablation, significantly inhibiting heat transfer to the insulation layer 1 and enhancing the ablation barrier. Furthermore, the boron phenolic composite material also possesses excellent chemical inertness, oxidation resistance, and long-term thermal aging stability, providing a reliable ablation protection mechanism for the ablation-resistant layer 2.

[0043] In addition, depending on the actual application requirements, optional ablation-resistant fibers also include other ultra-high temperature ceramic fibers, such as silicon carbide fibers, boron nitride fibers, and mullite fibers. These fibers can achieve efficient thermal management and resist ablation damage in high heat flux environments. Optional ablation-resistant resin-based composite materials also include one or more mixtures of polyarylene acetylene resin and phenol triazine resin. They perform well under different ablation conditions, such as extreme temperatures, highly corrosive media, or dynamic thermal shock, providing a flexible material adaptation scheme for the ablation-resistant layer 2 and ensuring long-term thermal protection and structural reliability during the use of the aircraft.

[0044] S3: Fill the ablation-resistant bulk molding compound onto the surface of the heat insulation layer 1 with the snap-fit ​​structure 11 and pre-compact it so that the ablation-resistant bulk molding compound and the snap-fit ​​structure 11 on the surface of the heat insulation layer 1 are interlocked to form an integrated blank. More specifically, the heat insulation layer 1 prepared in S1 is placed in the mold beforehand, and the ablation-resistant bulk molding compound is filled on the surface of the heat insulation layer 1 with the snap-fit ​​structure 11. During filling, the ablation-resistant bulk molding compound and the snap-fit ​​structure 11 of the heat insulation layer 1 should be fully interlocked. Then, the mold is used to pre-compact the upper ablation-resistant bulk molding compound to obtain an integrated blank.

[0045] S4: The integral blank is vacuum hot-pressed to form an ablation-resistant layer 2 on the surface of the heat insulation layer 1, thus obtaining an integrated thermal protection structure.

[0046] S401: Place the integrated blank into a vacuum bag and vacuum it; S402: The vacuum-sealed integral blank is placed into an autoclave and cured in a stepwise manner with gradually increasing temperature. The autoclave can be pressurized using vacuum pressure or by applying external pressure of 0MPa to 1.5MPa inside the autoclave to assist in hot pressing. Stepped curing specifically includes: First, a first-time curing process is performed at a first-time preset temperature within a first-time preset period. The first-time preset period and the first-time preset temperature are determined based on the curing requirements of the ablation-resistant bulk molding compound. Then, a second curing process is carried out at a second preset temperature within a second preset time. The second preset temperature is higher than the first preset temperature. The second preset temperature is determined according to the curing requirements of the ablation-resistant bulk molding compound. Finally, the material is cured three times at a third preset temperature within a third preset time period. The third preset temperature is higher than the second preset temperature. The third preset temperature is determined based on the curing requirements of the ablation-resistant bulk molding compound.

[0047] Taking the ablation-resistant layer 2 in this embodiment as an example of alumina ceramic fiber reinforced boron phenolic composite material, the first curing is carried out at a high temperature of 120°C for 2 hours. Then, during the second curing, the temperature of the autoclave is adjusted to 180°C and cured for 4 hours. Finally, during the third curing, the temperature of the autoclave is adjusted to 200°C and cured for 2 hours. This allows the ablation-resistant bulk molding compound to form the ablation-resistant layer 2 on the surface of the heat insulation layer 1. The final ablation-resistant layer 2 has good high-temperature erosion resistance and can withstand long-term erosion at temperatures exceeding 2000°C.

[0048] In other embodiments, the combined selection of a first preset temperature, a second preset temperature, a third preset temperature, a first preset time, a second preset time, a third preset time, and a specific number of stepped curing cycles is made based on the materials specifically selected for the heat insulation layer 1 and the ablation-resistant layer 2.

[0049] S403: After curing, demolding yields an integrated thermal protection structure.

[0050] After the ablation-resistant layer 2 has been cured, the integrated thermal protection structure can be demolded to obtain an integrated thermal protection structure made of the heat insulation layer 1 and the ablation-resistant layer 2.

[0051] Furthermore, based on the aforementioned method for preparing an integrated thermal protection structure with high efficiency and ablation resistance, this application also claims protection for an integrated thermal protection structure with high efficiency and ablation resistance, specifically manufactured using the aforementioned method, and comprising an insulation layer 1 and an ablation-resistant layer 2. The insulation layer 1 has a snap-fit ​​structure 11 on its surface, and the ablation-resistant layer 2 is disposed on the surface of the insulation layer 1 with the snap-fit ​​structure 11. The ablation-resistant layer 2 and the insulation layer 1 are integrally formed, reducing the possibility of delamination during prolonged use in high-temperature environments leading to thermal protection structure failure. This solves the technical problems in related technologies where the insulation layer and ablation-resistant layer need to be manufactured separately before assembly, and where delamination easily occurs between the insulation layers, ultimately leading to thermal protection structure failure. More specifically, the density of insulation layer 1 is between 0.4 g / cm³. 3 ~0.8g / cm 3 Between these values, the thermal conductivity is less than 0.1 W / (mK). In this embodiment, the heat insulation layer 1 is specifically made of quartz needle-punched felt reinforced phenolic aerogel material; the heat resistance temperature of the ablation-resistant layer 2 exceeds 2000℃. In this embodiment, the ablation-resistant layer 2 is specifically made of alumina ceramic fiber reinforced boron phenolic composite material.

[0052] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0053] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0054] 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 method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure, characterized in that, It includes: The heat-insulating fiber material is processed to obtain a heat-insulating layer (1) with a snap-fit ​​structure (11) on the surface. Ablative fibers and ablative resins are mixed to obtain ablative bulk molding compound; The ablation-resistant bulk molding compound is filled into the surface of the heat insulation layer (1) with the snap-fit ​​structure (11) and pre-compacted so that the ablation-resistant bulk molding compound and the snap-fit ​​structure (11) on the surface of the heat insulation layer (1) are interlocked to form an integrated blank. The integral blank is subjected to integral vacuum hot pressing, so that the ablation-resistant bulk molding compound forms an ablation-resistant layer (2) on the surface of the heat insulation layer (1), thus obtaining an integrated thermal protection structure.

2. The method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure as described in claim 1, characterized in that: Processing the heat-insulating fiber material to obtain a heat-insulating layer (1) with a snap-fit ​​structure (11) on the surface includes the following steps: The heat-insulating fiber material is dried and impurities are removed to obtain a dry fabric; The dried fabric is laid into the mold and pre-pressed in sequence, and then removable material is embedded in the surface of the dried fabric. The insulating resin is poured into the mold, avoiding removable materials, to fully impregnate the dry fabric and obtain an insulating preform. After the heat insulation preform is cured, it is dried at room temperature, and the removable material is removed to form a root structure on the surface to form a snap-fit ​​structure (11), thus obtaining a heat insulation layer (1) with a snap-fit ​​structure (11) on the surface.

3. The method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure as described in claim 2, characterized in that: Removable materials include soluble salts.

4. The method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure as described in claim 1, characterized in that: Processing the heat-insulating fiber material to obtain a heat-insulating layer (1) with a snap-fit ​​structure (11) on the surface includes the following steps: The heat-insulating fiber material is dried and impurities are removed to obtain a dry fabric; The dried fabric is laid into the mold for pre-compression; Heat insulation resin is poured into the mold until the heat insulation resin fully impregnates the dry fabric at the lower first thickness portion, and leaves the upper second thickness portion, so that the upper second thickness portion forms a hair structure, and a heat insulation preform is obtained. After the heat insulation preform is cured, it is dried at room temperature to form a snap-fit ​​structure (11) of the hair structure, thus obtaining a heat insulation layer (1) with a snap-fit ​​structure (11) on the surface.

5. The method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure as described in claim 1, characterized in that: An integrated thermal protection structure is obtained by integrally vacuum hot pressing an integrated blank, which includes: Place the integrated blank into a vacuum bag and vacuum it; The vacuum-sealed integral blank is placed into an autoclave and cured in a stepwise manner with gradually increasing temperature. After curing, demolding yields an integrated thermal protection structure.

6. The method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure as described in claim 5, characterized in that: The vacuum-sealed integral blank is placed into an autoclave and subjected to step-curing, which includes: The vacuum-sealed, one-piece blank is then placed into an autoclave: First, a first-time curing process is performed at a first-time preset temperature within a first-time preset period. The first-time preset period and the first-time preset temperature are determined based on the curing requirements of the ablation-resistant bulk molding compound. Then, a second curing process is carried out at a second preset temperature within a second preset time. The second preset temperature is higher than the first preset temperature. The second preset temperature is determined according to the curing requirements of the ablation-resistant bulk molding compound. Finally, the material is cured three times at a third preset temperature within a third preset time period. The third preset temperature is higher than the second preset temperature. The third preset temperature is determined based on the curing requirements of the ablation-resistant bulk molding compound.

7. The method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure as described in claim 1, characterized in that: Thermal insulation fiber materials include quartz needle-punched felt, ablation-resistant fibers include alumina ceramic fibers, and ablation-resistant resins include boron phenolic resins.

8. The method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure as described in claim 1, characterized in that: The density of the insulation layer (1) is between 0.4 g / cm³. 3 ~0.8g / cm 3 Between these values, the thermal conductivity is less than 0.1 W / (mK).

9. The method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure as described in claim 1, characterized in that: The ablation resistant layer (2) has a thermal resistance temperature exceeding 2000℃.

10. A method for preparing an ablation-resistant, high-efficiency, integrated thermal protection structure, characterized in that: It is prepared by the method of preparing an ablation-resistant, high-efficiency, integrated thermal protection structure according to any one of claims 1-9, comprising: The heat insulation layer (1) has a snap-fit ​​structure (11) on its surface; In addition, an ablation-resistant layer (2) is disposed on the side of the heat insulation layer (1) on which the snap-fit ​​structure (11) is provided, and the ablation-resistant layer (2) and the heat insulation layer (1) are integrally formed.

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