A composite structure integrating active cooling, heat protection, and electromagnetic wave absorption functions based on porous metastructures

Abstract

This invention discloses an integrated composite structure based on a porous superstructure for active cooling, heat protection, and electromagnetic wave absorption. From bottom to top, it comprises: a metal base plate, a ceramic-based high-temperature absorbing superstructure layer, a fiber-reinforced aerogel insulation layer, and an ultra-high temperature ablation-resistant coating. This integrated composite structure utilizes a three-dimensional superstructure, formed by a periodic array of porous cells using a lightweight ceramic-based absorbing agent, as its core component. It comprehensively leverages the synergistic effects of multiple mechanisms: the active thermal protection through phase change and sweating of the porous superstructure, the efficient heat insulation of the aerogel nanoporous network structure, the high-temperature resistance and ablation resistance of the ultra-high temperature ceramic coating, and the high-loss absorption of electromagnetic waves in the wide frequency and angular domains of the three-dimensional superstructure. This results in an integrated structural and functional structure that easily integrates thermal and electromagnetic protection, providing a new approach for achieving integrated high-temperature resistance, ablation resistance, heat insulation, and electromagnetic wave absorption protection for future high-speed aircraft shell components.

Description

Technical Field

[0001] This invention relates to the field of multifunctional integrated shell material technology for aircraft, and in particular to an integrated composite structure based on a porous superstructure that combines active cooling and heat protection with electromagnetic wave absorption. Background Technology

[0002] With the rapid development and maturation of aerospace technology, high-speed aircraft, represented by manned spaceflight, lunar exploration, deep space exploration, space shuttles, spacecraft return capsules, and reusable launch vehicles, have become a research hotspot. New high-speed aircraft face increasingly harsh thermal environments, enduring extreme high temperatures exceeding 1000°C and ablation during flight, placing stringent requirements on the heat protection and insulation performance of their shell materials. Thermal protection material systems are crucial for ensuring the normal operation of internal electronic components and manned spacecraft, and are trending towards low density, low thermal conductivity, and compatibility of heat protection and insulation functions. Since the 1950s, thermal protection material systems for aircraft have continuously developed, especially advanced ultra-lightweight reusable thermal protection materials, represented by ceramizable composite materials and fiber-reinforced composite materials, which have been successfully applied in advanced spacecraft. In particular, resin-based ablation thermal protection materials achieve heat protection through physicochemical endothermic reactions and possess advantages such as high reliability, high cost-effectiveness, and simple assembly, making them one of the most effective, mature, and economical thermal protection methods.

[0003] The multi-functionality and integration of thermal protection systems are inevitable requirements for the future development of advanced spacecraft, aiming to achieve compatibility and integration of multiple functions such as heat protection, thermal insulation, thermal load bearing, electromagnetic protection, and flame retardancy. Implementing electromagnetic wave absorption capabilities on spacecraft helps reduce electromagnetic pollution and interference, suppress electromagnetic noise, improve the operational stability of onboard electronic equipment, and enable integrated electromagnetic stealth protection designs with low-scattering target characteristics to evade radar early warning detection. Therefore, the development of new multi-functional integrated materials for heat protection, thermal insulation, and electromagnetic wave absorption has become a key supporting technology for promoting the development of new high-speed spacecraft. Summary of the Invention

[0004] This invention proposes an integrated composite structure based on a porous superstructure, combining active cooling, heat protection, and electromagnetic wave absorption functions. This structure features integrated structural and functional design and easily achieves multi-functional integration of thermal and electromagnetic protection. It provides a new approach for achieving multi-functional compatibility and integration of heat protection, thermal insulation, and electromagnetic protection in future high-speed aircraft components. To achieve the above-mentioned objectives, this invention discloses the following technical solutions.

[0005] The composite structure based on the active cooling and heat protection and electromagnetic wave absorption functions of the porous superstructure includes, from bottom to top: a metal base plate, a ceramic-based high-temperature wave-absorbing superstructure layer, a fiber-reinforced aerogel insulation layer, and an ultra-high temperature ablation-resistant coating.

[0006] Furthermore, the ceramic-based high-temperature absorbing superstructure layer is a three-dimensional superstructure formed by molding a ceramic-based absorbing agent into a periodic array of porous structural cells. The pores of the porous ceramic-based high-temperature absorbing superstructure layer provide flow channels for the cooling medium in phase change sweating cooling and active thermal protection.

[0007] Optionally, the ceramic-based microwave absorbing agent includes any one of lanthanum strontium manganese oxide ceramic microwave absorbing agents, SiC microwave absorbing agents, SiBC microwave absorbing agents, etc.

[0008] Optionally, the cooling medium includes any one of gaseous or liquid fluids such as water or supercritical CO2.

[0009] Furthermore, the thickness of the ceramic-based high-temperature absorbing superstructure layer is 8~15 mm.

[0010] Furthermore, the fiber-reinforced aerogel insulation layer is composed of a mixture of ceramic fibers and ceramic aerogel.

[0011] Optionally, the ceramic fiber includes any one of quartz fiber, alumina fiber, etc.

[0012] Optionally, the ceramic aerogel includes any one of silica aerogel, alumina aerogel, etc.

[0013] Furthermore, the thickness of the fiber-reinforced aerogel insulation layer is 5~15 mm.

[0014] Furthermore, the ultra-high temperature ablation-resistant coating is formed by uniformly mixing a ceramicizable polymer precursor and ultra-high temperature ceramic powder and then heat-treating them.

[0015] Optionally, the ceramicizable polymer precursor includes at least one of polysilazane, polysiloborazane, polycarbosilane, etc., which can be converted into a Si(C / N) nano-ceramic phase under high temperature conditions.

[0016] Optionally, the ultra-high temperature ceramic powder includes at least one of carbides, borides, nitrides, etc.

[0017] Compared with the prior art, the beneficial effects of this invention include: The integrated composite structure of active cooling and thermal protection and electromagnetic wave absorption based on porous superstructure of this invention uses a three-dimensional superstructure as the core component, which is prepared by a lightweight ceramic-based absorbing agent into a periodic array of porous cell units. It comprehensively utilizes the synergistic effect of multiple mechanisms, such as the active thermal protection of the porous superstructure through phase change sweating, the efficient thermal insulation of the aerogel nanoporous network structure, the high temperature resistance and ablation resistance of the ultra-high temperature ceramic coating, and the high loss absorption of electromagnetic waves in the wide frequency and wide angle domain of the three-dimensional superstructure. It has the characteristics of integrated structure and function, and it is easy to achieve multi-functional integration of thermal protection and electromagnetic protection. It can provide a new way for future high-speed aircraft components to achieve integrated ablation resistance, thermal insulation and electromagnetic wave absorption protection. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention and do not constitute an undue limitation of the invention.

[0019] Figure 1 The following is a schematic diagram of an integrated composite structure based on a porous superstructure that combines active cooling, heat protection, and electromagnetic wave absorption functions.

[0020] Figure 2 The following is a schematic diagram of the structure of the ceramic-based high-temperature absorbing superstructure layer in the embodiments below.

[0021] Figure 3 for Figure 2 A schematic diagram of the cooling of porous cell structure in a ceramic-based high-temperature absorbing superstructure layer.

[0022] Figure 4 This is a schematic diagram of another ceramic-based high-temperature absorbing superstructure layer in the following embodiments.

[0023] Figure 5 for Figure 4 A schematic diagram of the cooling of the porous structure of the ceramic-based high-temperature absorbing superstructure layer.

[0024] Figure 6 for Figure 2 Simulation results of electromagnetic reflection of ceramic-based high-temperature absorbing superstructure.

[0025] Figure 7 for Figure 4 Simulation results of electromagnetic reflection of a ceramic-based high-temperature absorbing superstructure.

[0026] The markings in the diagram represent: 1-metal base plate, 2-ceramic-based high-temperature absorbing superstructure layer, 3-fiber-reinforced aerogel insulation layer, and 4-ultra-high temperature ablation-resistant coating. Detailed Implementation

[0027] For ease of description, the terms "up," "down," "left," and "right" appearing in this invention only indicate that they correspond to the up, down, left, and right directions in the accompanying drawings. They do not limit the structure and are merely used to facilitate the description of the invention and to simplify the description. They do not indicate or imply that the device or component referred to needs to have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. The invention will now be further described through the accompanying drawings and specific embodiments.

[0028] refer to Figure 1 This example illustrates an integrated composite structure based on a porous superstructure that combines active cooling and thermal protection with electromagnetic wave absorption. It comprehensively utilizes the synergistic effects of multiple mechanisms: the active thermal protection through phase change and sweating cooling of the porous superstructure, the efficient thermal insulation of the aerogel nanoporous network structure, the high-temperature resistance and ablation resistance of the ultra-high-temperature ceramic coating, and the high-loss electromagnetic wave absorption of the three-dimensional superstructure across a wide frequency and angle domain. This achieves multifunctional integration of thermal and electromagnetic protection. Specifically, the integrated composite structure based on a porous superstructure comprises, from bottom to top: a metal base plate 1, a ceramic-based high-temperature absorbing superstructure layer 2, a fiber-reinforced aerogel thermal insulation layer 3, and an ultra-high-temperature ablation-resistant coating 4. Wherein:

[0029] The ceramic-based high-temperature absorbing superstructure layer 2 is a three-dimensional superstructure formed by molding a ceramic-based absorbing agent into a periodic array of porous structural cells. The ceramic-based absorbing agent can be selected from any one of lanthanum-strontium-manganese oxide ceramic absorbing agents, SiC absorbing agents, SiBC absorbing agents, etc. The thickness of the ceramic-based high-temperature absorbing superstructure layer 2 is 8~15 mm, such as 8 mm, 10 mm, 12 mm, 15 mm, etc. Figure 2 and Figure 4 These are three-dimensional superstructures consisting of periodic arrays of porous cell units with two different structures. Figure 3 and Figure 5 These are schematic diagrams illustrating the cooling of cooling substrates (such as liquid water, supercritical CO2, etc.) through these two three-dimensional superstructures. This embodiment utilizes the porous structure of the ceramic-based high-temperature absorbing superstructure layer 2 to achieve phase change sweating cooling for active thermal protection, and the principle of high loss over a wide frequency and angle domain for electromagnetic waves in the three-dimensional superstructure. Specifically, the porous structure allows for the flow and infiltration of cooling media such as water and supercritical CO2, enabling effective heat protection through phase change sweating cooling. Furthermore, the strong loss absorption of electromagnetic waves over a wide frequency and angle domain by the cooling media and the three-dimensional electromagnetic superstructure achieves excellent electromagnetic protection performance. Figure 6 and Figure 7 The figures show the electromagnetic wave reflection simulation curves of two different porous three-dimensional superstructures formed using lanthanum-strontium-manganese-oxygen ceramic absorbing agents in the 2-40 GHz frequency band. Both of them clearly have wide-frequency low electromagnetic reflection characteristics.

[0030] The fiber-reinforced aerogel insulation layer 3 is composed of a mixture of ceramic fibers and ceramic aerogel. The ceramic fibers can be selected from any of the following: quartz fibers, alumina fibers, etc. The ceramic aerogel can be selected from any of the following: silica aerogel, alumina aerogel, etc. The thickness of the fiber-reinforced aerogel insulation layer 3 is 5~15 mm, such as 5 mm, 10 mm, 12 mm, 15 mm, etc. Benefiting from the high-temperature mechanical properties of the ceramic matrix material and the efficient thermal insulation performance of the porous network of the aerogel, the fiber-reinforced aerogel insulation layer 3 can achieve a high-temperature thermal insulation effect.

[0031] The ultra-high temperature ablation-resistant coating 4 is formed by uniformly mixing a ceramizable polymer precursor and ultra-high temperature ceramic powder, followed by heat treatment. The ceramizable polymer precursor can be selected from at least one of polysilazane, polysiloborazane, and polycarbosilane, and the ultra-high temperature ceramic powder can be selected from at least one of carbides, borides, and nitrides. The ceramizable polymer precursor can be transformed into nano-ceramic phases such as SiC, SiBC, and SiBCN at a high temperature of 800~1400℃, and then converted into a nano-multiphase ceramic coating by pneumatic heating, achieving an ultra-high temperature ablation-resistant thermal protection effect. This embodiment utilizes a three-dimensional superstructure, formed by a periodic array of porous cell units using a lightweight ceramic-based absorbing agent, as its core component. This comprehensively leverages the synergistic effects of multiple mechanisms: the active thermal protection through dielectric phase change sweating of the porous superstructure, the efficient thermal insulation of the aerogel nanoporous network structure, the high-temperature resistance and ablation resistance of the ultra-high-temperature ceramic coating, and the high-loss electromagnetic wave absorption of the three-dimensional superstructure across a wide frequency and angle domain. It possesses integrated structural and functional characteristics and easily achieves multi-functional integration of thermal and electromagnetic protection. This provides a new approach for achieving integrated ablation resistance, thermal insulation, and electromagnetic wave absorption protection for future high-speed aircraft components.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite structure integrating active cooling and thermal protection with electromagnetic wave absorption based on a porous metastructure, characterized in that, The composite structure, from bottom to top, includes: a metal base plate, a ceramic-based high-temperature absorbing superstructure layer, a fiber-reinforced aerogel insulation layer, and an ultra-high temperature ablation-resistant coating. The ceramic-based high-temperature absorbing superstructure layer is a three-dimensional superstructure formed by a periodic array of porous cell units using a ceramic-based absorbing agent. The pores of the porous ceramic-based high-temperature absorbing superstructure layer provide flow channels for the cooling medium in the phase change sweating cooling and active thermal protection system. The ceramic-based absorbing agent includes any one of lanthanum strontium manganese oxide ceramic absorbing agent, SiC absorbing agent, and SiBC absorbing agent. The cooling medium includes any one of water and supercritical CO2. The fiber-reinforced aerogel insulation layer is composed of a mixture of ceramic fibers and ceramic aerogel. The ultra-high temperature ablation-resistant coating is formed by uniformly mixing a ceramicizable polymer precursor and ultra-high temperature ceramic powder and then heating it.

2. The integrated composite structure based on porous metastructure with active cooling, heat protection, and electromagnetic wave absorption functions as described in claim 1, characterized in that, The thickness of the ceramic-based high-temperature absorbing superstructure layer is 8~15 mm.

3. The integrated composite structure based on porous metastructure with active cooling, heat protection, and electromagnetic wave absorption functions as described in claim 1, characterized in that, The ceramic fiber includes any one of quartz fiber and alumina fiber.

4. The integrated composite structure based on porous metastructure with active cooling, heat protection, and electromagnetic wave absorption functions as described in claim 1, characterized in that, The ceramic aerogel includes any one of silica aerogel and alumina aerogel.

5. The integrated composite structure based on porous metastructure with active cooling, heat protection, and electromagnetic wave absorption functions as described in claim 1, characterized in that, The thickness of the fiber-reinforced aerogel insulation layer is 5~15 mm.

6. The integrated composite structure based on porous metastructure with active cooling, heat protection, and electromagnetic wave absorption functions according to claim 1, characterized in that, The ceramizable polymer precursor includes at least one of polysilazane, polysiloborazane, and polycarbosilane.

7. The integrated composite structure based on porous metastructure with active cooling, heat protection, and electromagnetic wave absorption functions according to claim 1, characterized in that, The ultra-high temperature ceramic powder includes at least one of carbides, borides, and nitrides.

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