High-temperature-resistant semi-flexible thermal protection member and preparation method thereof

Abstract

The application provides a high-temperature-resistant semi-flexible heat protection component, and relates to the field of heat protection. The component comprises, from top to bottom, a silicon-based coating, a thin-wall metal radiation layer and a high-temperature-resistant heat insulation layer. The high-temperature-resistant heat insulation layer is made of multiple layers of aerogel heat insulation material and is wrapped by a fiber cloth material. The front surface of the thin-wall metal radiation layer corresponds to the high-temperature-resistant heat insulation layer, and the outer circle of the thin-wall metal radiation layer is bent to wrap the side edges of the high-temperature-resistant heat insulation layer. The thickness of the bent edge of the thin-wall metal radiation layer is higher than the thickness of the high-temperature-resistant heat insulation layer, and an air layer is formed between the thin-wall metal radiation layer and the high-temperature-resistant heat insulation layer. The silicon-based coating is uniformly sprayed on the surface of the side of the thin-wall metal radiation layer away from the high-temperature-resistant heat insulation layer. The heat protection component has the characteristics of high heat resistance, high corrosion resistance and conformability, and has the advantages of rigid and flexible heat protection components. The heat protection component is suitable for the heat protection of engines and other hot ends under complex environmental conditions such as high-efficiency heat insulation, high-temperature airflow scouring, rain and wet heat.

Description

Technical Field

[0001] This invention relates to the field of thermal protection technology, specifically to a high-temperature resistant semi-flexible thermal protection component and its preparation method. Background Technology

[0002] Thermal protection components are critical structures used in extreme high-temperature environments. Through material design and composite processes, they block heat transfer, thereby providing thermal protection for equipment, systems, and personnel. Hot-end components such as engines require thermal protection components that, within space and weight constraints, achieve efficient thermal insulation while also possessing excellent environmental adaptability, including resistance to high temperatures, humidity, and corrosion. Traditional thermal protection components include rigid ceramic insulation tiles and flexible insulation felt. Ceramic insulation tiles suffer from brittleness and poor mechanical properties, severely limiting their application in the field of thermal protection components. Insulation felt offers superior thermal matching and is relatively simple to manufacture and install; however, it is prone to deformation and peeling during long-term use, which can easily lead to functional failure. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention aims to provide a high-temperature resistant semi-flexible thermal protection component. This thermal protection component has the characteristics of high heat resistance, high corrosion resistance, and conformability, and combines the advantages of rigid and flexible thermal protection components. The component has strong overall thermal shock resistance and environmental adaptability, and can effectively adapt to complex environmental conditions such as high-efficiency heat insulation required by hot ends such as engines, high-temperature airflow scouring, rain or humid heat.

[0004] Another object of the present invention is to provide a method for preparing the above-mentioned high-temperature resistant semi-flexible thermal protection component.

[0005] The objective of this invention is achieved through the following technical solution: A high-temperature resistant semi-flexible thermal protection component comprises, from top to bottom, a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer is composed of multiple layers of aerogel insulation material, wrapped with fiber cloth material, and finally sewn together with high-temperature fiber stitching. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thickness of the bent edge of the thin-walled metal radiant layer is higher than the thickness of the high-temperature resistant insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature resistant insulation layer. The silicon-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature resistant insulation layer.

[0006] Based on further optimization of the above scheme, the silicon-based coating includes a silicone rubber matrix, phenyltrimethoxysilane, KH560 (γ-glycidoxypropyltrimethoxysilane), bismaleimide, and nano-SiO2 particles. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%, and the nano-SiO2 particles have a particle size of 20-50 nm. The thickness of the silicon-based coating is 30-70 μm.

[0007] Based on further optimization of the above scheme, the thin-walled metal radiation layer is made of Ti foil and is sequentially subjected to plasma etching, anodizing and immersion in 3-isocyanate propyltrimethoxysilane; the thickness of the thin-walled metal radiation layer is 0.05-0.15 mm.

[0008] Based on further optimization of the above scheme, the thickness of the air interlayer is 0.5-1mm; the outer ring of the thin-walled metal radiation layer is bent to wrap around the side of the high-temperature insulation layer, and the width of the protrusion on the back of the high-temperature insulation layer is 50-100mm.

[0009] Based on further optimization of the above scheme, the fiber cloth material is either basalt fiber cloth or glass fiber cloth, and the aerogel insulation material is at least one of glass fiber reinforced aerogel material, basalt fiber reinforced aerogel material, and alumina fiber reinforced aerogel material; the thickness of the fiber cloth material is 0.1-0.2 mm, and the thickness of the single-layer aerogel material is 0.5-2 mm.

[0010] A method for preparing a high-temperature resistant semi-flexible thermal protection component, comprising: Step S1, Pretreatment of thin-walled metal radiation layer: First, clean and vacuum dry the thin-walled metal radiation layer to remove oil stains from its surface; then, perform plasma etching and anodizing on the treated thin-walled metal radiation layer in sequence. Step S2, Preparation of Silicon-based Coating Base Solution: First, disperse nano-SiO2 particles in anhydrous toluene, and add hydroxyl-terminated polymethylphenylsiloxane (molecular weight 5000-10000). Under nitrogen protection, carry out a reflux reaction. After centrifugation and drying, add the coated nano-SiO2 particles and KH560 to a high-pressure reactor, and inject the silicone rubber matrix. After sealing, introduce CO2 to the critical state, stir evenly, and after depressurization, obtain a uniformly dispersed nano-SiO2 / silicone rubber matrix. Step S3, Thin-walled metal radiation layer treatment: Immerse the pretreated thin-walled metal radiation layer from step S1 in 3-isocyanate propyltrimethoxysilane, let it stand at room temperature for a period of time, and then take it out and dry it. Step S4, Silicon-based Coating Spraying: First, dissolve KH560 and phenyltrimethoxysilane in deionized water containing acetic acid, and stir at low temperature to form a hydrolyzed silane mixture; take the nano-SiO2 / silicone rubber matrix, hydrolyzed silane mixture and bismaleimide (BMI) from step S2, stir evenly, and spray it onto the surface of the thin-walled metal radiation layer in step S3, pre-curing to form the bottom layer; adjust the phenyltrimethoxysilane content of the hydrolyzed silane mixture in the spraying solution, with the other components the same as the bottom layer, and spray it onto the bottom layer surface, pre-curing to form the middle layer; adjust the phenyltrimethoxysilane and bismaleimide content of the hydrolyzed silane mixture in the spraying solution, spray it onto the middle layer surface, and pre-curing to form the top layer; finally, perform gradient temperature curing and annealing to obtain the thin-walled metal radiation layer with sprayed silicon-based coating; Step S5, Preparation of high temperature resistant insulation layer: First, arrange the multi-layer aerogel insulation material from top to bottom, then wrap the arranged multi-layer aerogel insulation material with fiber cloth material, and finally connect the wrapped material with high temperature fiber suture thread in a V-shape to obtain the high temperature resistant insulation layer. Step S6, Preparation of thermal protection components: The high-temperature resistant heat insulation layer from step S5 is placed on the side of the thin-walled metal radiation layer away from the silicon-based coating, and the high-temperature resistant heat insulation layer is covered by bending the side of the thin-walled metal radiation layer. The inner side of the thin-walled metal radiation layer (i.e. the side away from the silicon-based coating) is connected to the high-temperature resistant heat insulation layer by pre-coating with an adhesive.

[0011] Based on further optimization of the above scheme, the cleaning in step S1 is specifically as follows: ultrasonic cleaning with anhydrous ethanol for 13-17 min; vacuum drying at 60-70℃ for 1.3-1.7 h.

[0012] Based on further optimization of the above scheme, the plasma etching in step S1 is specifically as follows: argon gas is used for plasma etching, with a power of 100-150W, an argon gas flow rate of 18-22 sccm, a vacuum degree of 4.5-5.5Pa, and an etching time of 5-8 min; the anodic oxidation is specifically as follows: the thin-walled metal radiation layer after plasma etching is used as the anode, graphite is used as the cathode, 0.5 mol / L sulfuric acid solution is used as the electrolyte, and oxidation is carried out at a DC voltage of 9-11V for 12-18 min.

[0013] Based on further optimization of the above scheme, the mass-to-volume ratio of nano-SiO2 particles, anhydrous toluene, and hydroxyl-terminated polymethylphenylsiloxane in step S2 is 9.5–10.5 g: 95–105 mL: 4.5–5.5 g; the reflux reaction temperature is 75–85 °C and the time is 3.5–4.5 h; the centrifugal drying is specifically as follows: first, a high-speed centrifuge is used at a speed of 8000–10000 rpm for 15–20 min, and then the nano-SiO2 particles coated after centrifugation are placed in a vacuum drying oven at a temperature of 60–80 °C for 2–3 h.

[0014] Based on further optimization of the above scheme, the mass ratio of coated nano-SiO2 particles, KH560, and silicone rubber matrix in step S2 is 4.5-5.5: 0.2-0.3: 48-52; the critical state is a temperature of 31.1℃, a pressure of 7.38MPa, and a stirring time of 28-32min.

[0015] Based on further optimization of the above scheme, the resting time in step S3 is 8-12 minutes, the drying temperature is 75-85℃, and the drying time is 5-7 minutes.

[0016] Based on further optimization of the above scheme, in step S4, the mass-to-volume ratio of KH560, phenyltrimethoxysilane, and deionized water containing acetic acid is 1.8–2.2 g: 4.8–5.2 g: 48–52 mL; the acetic acid content in the deionized water is 0.08–0.12 wt%; the low-temperature stirring temperature is 3–5 °C, the stirring rate is 120–150 rpm, and the stirring time is 0.8–1.2 h.

[0017] Based on further optimization of the above scheme, in step S4, the content of phenyltrimethoxysilane in the bottom layer, middle layer, and surface layer increases sequentially, and the bismaleimide content in the surface layer is lower than that in the bottom layer; specifically: in the bottom layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.45-0.55, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 2.5-3.5 wt% of the nano-SiO2 / silicone rubber matrix; in the middle layer, the content of nano-SiO2 / silicone rubber matrix is ​​100:0.45-0.55, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 2.5-3.5 wt% of the nano-SiO2 / silicone rubber matrix; The mass ratio of iO2 / silicone rubber matrix to bismaleimide is 100:0.45-0.55, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 4.5-5.5 wt% of the nano-SiO2 / silicone rubber matrix; in the surface layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.25-0.35, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 7.5-8.5 wt% of the nano-SiO2 / silicone rubber matrix.

[0018] Based on further optimization of the above scheme, in step S4, the pre-curing temperature of the bottom layer, the middle layer and the top layer are all 75-85℃ and the pre-curing time is all 8-12min; the spraying thickness of the middle layer is greater than that of the bottom layer and the bottom layer and the top layer are equal.

[0019] Based on further optimization of the above scheme, the gradient temperature curing in step S4 specifically involves: placing the sprayed thin-walled metal radiation layer in an oven, heating it to 75–85°C at a rate of 4–6°C / min and holding it at that temperature for 28–32 min, then heating it to 115–125°C at a rate of 3–4°C / min and holding it at that temperature for 0.8–1.2 h, and finally heating it to 175–185°C at a rate of 3–4°C / min and holding it at that temperature for 1.8–2.2 h; the annealing specifically involves: after curing, cooling it to 58–62°C with the oven temperature and holding it at that temperature for 1.8–2.2 h, and then cooling it to room temperature at a rate of 0.5–1°C / min.

[0020] The following are the technical effects of the present invention: This invention achieves dual physical and chemical anchoring through pretreatment of a thin-walled metal radiant layer via plasma etching and anodic oxidation. Then, a silicon-based material, composed of KH560, phenyltrimethoxysilane, a nano-SiO2 / silicone rubber matrix, and bismaleimide, is sprayed onto the thin-walled metal radiant layer. This not only improves the overall mechanical properties and wear resistance of the silicon-based coating but also balances the high-temperature resistance and flexibility of the silicon-based coating through dynamic crosslinking and gradient coating design. This ensures that the silicon-based coating effectively resists stress and strain during bending and high-temperature processes of the thin-walled metal radiant layer, avoiding cracking caused by bending or thermal stress. Simultaneously, the design and preparation process of the silicon-based coating and the thin-walled metal radiant layer effectively enhances the bonding strength between them, preventing cracking and peeling of the coating due to the difference in expansion coefficients between the silicone rubber and titanium foil.

[0021] The thermal protection component provided by this invention can conformally match the hot end components, overcoming the shortcomings of metal corrosion and high-temperature oxidation under extreme environmental conditions. At the same time, the semi-open encapsulation structure effectively reduces weight and achieves lightweight thermal insulation. Furthermore, the entire thermal protection component has high overall bonding strength, good interface compatibility, and good thermal stability, effectively avoiding problems such as interlayer separation, coating cracking, or peeling during bending or high-temperature processes, ensuring long-term stability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the thermal protection component in an embodiment of the present invention.

[0023] Figure 2 This is a rear (or bottom) view of the thermal protection component in an embodiment of the present invention.

[0024] Among them, 10 is a silicon-based coating; 20 is a thin-walled metal radiation layer; 21 is an air interlayer; 31 is an aerogel insulation material; and 32 is a fiber cloth material. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0026] Example 1: A high-temperature resistant semi-flexible thermal protection component comprises, from top to bottom, a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer is composed of 16 layers of aerogel insulation material, wrapped with fiber cloth, and finally sewn together with high-temperature fiber stitching. The fiber cloth material is basalt fiber cloth, and the aerogel insulation material is a combination of glass fiber reinforced aerogel and basalt fiber reinforced aerogel. The fiber cloth material has a thickness of 0.1 mm, and the thickness of a single layer of aerogel material is 0.5 mm. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thin-walled metal radiant layer is made of Ti foil and is sequentially subjected to plasma etching, anodizing, and immersion in 3-isocyanate propyltrimethoxysilane. The thickness of the thin-walled metal radiant layer is 0.05 mm. The thickness of the bent edge of the thin-walled metal radiant layer is greater than that of the high-temperature resistant insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature resistant insulation layer; the thickness of the air gap is 0.5 mm; the outer ring of the thin-walled metal radiant layer is bent to wrap around the side of the high-temperature resistant insulation layer, and the width of the protrusion on the back of the high-temperature resistant insulation layer is 50 mm. A silicon-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature resistant insulation layer. The silicon-based coating includes a silicone rubber matrix, phenyltrimethoxysilane, KH560 (γ-glycidyl etheroxypropyltrimethoxysilane), bismaleimide, and nano-SiO2 particles. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%, and the nano-SiO2 particles have a particle size of 20 nm; the thickness of the silicon-based coating is 30 μm.

[0027] A method for preparing a high-temperature resistant semi-flexible thermal protection component, comprising: Step S1: Pretreatment of thin-walled metal radiation layer: First, ultrasonically clean the thin-walled metal radiation layer with anhydrous ethanol for 13 minutes, and then vacuum dry the cleaned thin-walled metal radiation layer at a temperature of 60℃ for 1.7 hours to remove oil stains from the surface of the thin-walled metal radiation layer.

[0028] The thin-walled metal radiant layer was then subjected to plasma etching and anodizing in sequence. The plasma etching was performed using argon gas at a power of 100W, a flow rate of 18sccm, a vacuum of 4.5Pa, and an etching time of 8min. The anodizing was performed using the plasma-etched thin-walled metal radiant layer as the anode and graphite as the cathode, with 0.5mol / L sulfuric acid solution as the electrolyte, and oxidation was carried out at a DC voltage of 9V for 18min.

[0029] Step S2, Preparation of Silicon-based Coating Base Solution: First, disperse nano-SiO2 particles in anhydrous toluene, and add hydroxyl-terminated polymethylphenylsiloxane (molecular weight 5000-10000). The mass-to-volume ratio of nano-SiO2 particles, anhydrous toluene, and hydroxyl-terminated polymethylphenylsiloxane is 9.5g:95mL:4.5g. Perform a reflux reaction under nitrogen protection at 75℃ for 4.5 hours. After centrifugation and drying, specifically, centrifuge at 8000 rpm for 20 minutes using a high-speed centrifuge, then... The centrifuged and coated nano-SiO2 particles were placed in a vacuum drying oven and dried at 60℃ for 3 hours. The coated nano-SiO2 particles and KH560 were added to a high-pressure reactor and a silicone rubber matrix was injected. The mass ratio of the coated nano-SiO2 particles, KH560, and silicone rubber matrix was 4.5:0.2:48. After sealing, CO2 was introduced to the critical state, which was 31.1℃ and 7.38MPa. The mixture was stirred evenly for 28 minutes. After depressurization, a uniformly dispersed nano-SiO2 / silicone rubber matrix was obtained.

[0030] Step S3, Thin-walled metal radiation layer treatment: Immerse the pretreated thin-walled metal radiation layer from step S1 in 3-isocyanate propyltrimethoxysilane, let it stand at room temperature for 8 minutes, then remove it and dry it at 75°C for 7 minutes.

[0031] Step S4, Silicon-based coating spraying: First, dissolve KH560 and phenyltrimethoxysilane in deionized water containing acetic acid. The mass-to-volume ratio of KH560, phenyltrimethoxysilane and deionized water containing acetic acid is 1.8g:4.8g:48mL, and the acetic acid content is 0.08wt%. Stir at low temperature to form a hydrolyzed silane mixture. The low temperature stirring temperature is 3℃, the stirring speed is 120rpm, and the stirring time is 1.2h.

[0032] After uniformly stirring the nano-SiO2 / silicone rubber matrix, hydrolyzed silane mixture, and bismaleimide (BMI) from step S2, spray it onto the surface of the thin-walled metal radiation layer in step S3, pre-curing to form the bottom layer. The pre-curing temperature is 75℃, the pre-curing time is 12 min, and the bottom layer thickness is 9 μm. Adjust the phenyltrimethoxysilane content of the hydrolyzed silane mixture in the spraying solution, keeping the other components the same as the bottom layer, and spray it onto the bottom layer surface. Pre-curing to form the middle layer, the pre-curing temperature is 75℃, the pre-curing time is 12 min, and the middle layer thickness is 12 μm. Adjust the phenyltrimethoxysilane and bismaleimide content of the hydrolyzed silane mixture in the spraying solution, spray it onto the middle layer surface, and pre-curing to form the top layer, the pre-curing temperature is 75℃, the pre-curing time is 12 min, and the top layer thickness is 9 μm. The bottom layer, middle layer, and top layer... The content of phenyltrimethoxysilane increases sequentially, with bismaleimide in the surface layer being lower than that in the bottom layer. Specifically: in the bottom layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.45, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 2.5 wt% of the nano-SiO2 / silicone rubber matrix; in the middle layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.45, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 4.5 wt% of the nano-SiO2 / silicone rubber matrix; in the surface layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.25, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 7.5 wt% of the nano-SiO2 / silicone rubber matrix.

[0033] Finally, gradient temperature curing and annealing are performed to obtain a thin-walled metallic radiation layer with a sprayed silicon-based coating. The gradient temperature curing is as follows: the sprayed thin-walled metallic radiation layer is placed in an oven and heated to 75°C at a rate of 4°C / min and held for 32 min, then heated to 115°C at a rate of 3°C / min and held for 1.2 h, and finally heated to 175°C at a rate of 3°C / min and held for 2.2 h. The annealing is as follows: after curing, the temperature is cooled to 58°C with the oven temperature and held for 2.2 h, and then cooled to room temperature at a rate of 0.5°C / min.

[0034] Step S5, Preparation of high-temperature heat insulation layer: First, arrange 16 layers of aerogel heat insulation material from top to bottom (the performance of the aerogel heat insulation material can be set to decrease sequentially according to the direction of the heat source, i.e., place the high-temperature section aerogel heat insulation material near the heat source, and then place the medium-temperature section or low-temperature section aerogel heat insulation material in sequence). Then, wrap the arranged 16 layers of aerogel heat insulation material with fiber cloth material. Finally, connect the wrapped material with high-temperature fiber suture thread in a V-shape to obtain the high-temperature heat insulation layer.

[0035] Step S6, Preparation of thermal protection components: The high-temperature resistant heat insulation layer from step S5 is placed on the side of the thin-walled metal radiation layer away from the silicon-based coating, and the high-temperature resistant heat insulation layer is covered by bending the side of the thin-walled metal radiation layer. The inner side of the thin-walled metal radiation layer (i.e. the side away from the silicon-based coating) is connected to the high-temperature resistant heat insulation layer by pre-coating with an adhesive (the adhesive can be silicone rubber).

[0036] Example 2: A high-temperature resistant semi-flexible thermal protection component comprises, from top to bottom, a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer consists of seven layers of aerogel insulation material stacked together, wrapped with fiber cloth, and finally sewn together with high-temperature fiber stitching. The fiber cloth material is basalt fiber cloth, and the aerogel insulation material is basalt fiber reinforced aerogel material. The thickness of the fiber cloth material is 0.15 mm, and the thickness of a single layer of aerogel material is 1.2 mm. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thin-walled metal radiant layer is made of Ti foil and is sequentially subjected to plasma etching, anodizing, and immersion in 3-isocyanate propyltrimethoxysilane. The thickness of the thin-walled metal radiant layer is 0.1 mm. The thickness of the bent edge of the thin-walled metal radiant layer is greater than that of the high-temperature resistant insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature resistant insulation layer; the thickness of the air gap is 0.7 mm; the outer ring of the thin-walled metal radiant layer is bent to wrap around the side of the high-temperature resistant insulation layer, and the width of the protrusion on the back of the high-temperature resistant insulation layer is 75 mm. A silicon-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature resistant insulation layer. The silicon-based coating includes a silicone rubber matrix, phenyltrimethoxysilane, KH560 (γ-glycidyl etheroxypropyltrimethoxysilane), bismaleimide, and nano-SiO2 particles. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%, and the nano-SiO2 particles have a particle size of 35 nm; the thickness of the silicon-based coating is 50 μm.

[0037] A method for preparing a high-temperature resistant semi-flexible thermal protection component, comprising: Step S1: Pretreatment of thin-walled metal radiation layer: First, ultrasonically clean the thin-walled metal radiation layer with anhydrous ethanol for 15 minutes, and then vacuum dry the cleaned thin-walled metal radiation layer at a temperature of 65℃ for 1.5 hours to remove oil stains from the surface of the thin-walled metal radiation layer.

[0038] The thin-walled metal radiant layer was then subjected to plasma etching and anodizing in sequence. The plasma etching was performed using argon gas at a power of 125W, a flow rate of 20sccm, a vacuum of 5Pa, and an etching time of 6.5min. The anodizing was performed using the plasma-etched thin-walled metal radiant layer as the anode and graphite as the cathode, with 0.5mol / L sulfuric acid solution as the electrolyte, and oxidation was carried out at a DC voltage of 10V for 15min.

[0039] Step S2, Preparation of Silicon-based Coating Base Solution: First, disperse nano-SiO2 particles in anhydrous toluene, and add hydroxyl-terminated polymethylphenylsiloxane (molecular weight 5000-10000). The mass-to-volume ratio of nano-SiO2 particles, anhydrous toluene, and hydroxyl-terminated polymethylphenylsiloxane is 10g:100mL:5g. Perform a reflux reaction under nitrogen protection at 80℃ for 4 hours. After centrifugation and drying, specifically, use a high-speed centrifuge at 9000rpm for 17 minutes, then... The nano-SiO2 particles coated with the core were placed in a vacuum drying oven and dried at 70℃ for 2.5h. The coated nano-SiO2 particles and KH560 were added to a high-pressure reactor and a silicone rubber matrix was injected. The mass ratio of the coated nano-SiO2 particles, KH560 and silicone rubber matrix was 5:0.25:50. After sealing, CO2 was introduced to the critical state, which was 31.1℃ and 7.38MPa. The mixture was stirred evenly for 30min. After depressurization, a uniformly dispersed nano-SiO2 / silicone rubber matrix was obtained.

[0040] Step S3, Thin-walled metal radiation layer treatment: Immerse the pretreated thin-walled metal radiation layer from step S1 in 3-isocyanate propyltrimethoxysilane, let it stand at room temperature for 10 minutes, then remove it and dry it at 80°C for 6 minutes.

[0041] Step S4, Silicon-based Coating Spraying: First, dissolve KH560 and phenyltrimethoxysilane in deionized water containing acetic acid. The mass-to-volume ratio of KH560, phenyltrimethoxysilane, and deionized water containing acetic acid is 2g:5g:50mL, and the acetic acid content is 0.1wt%. Stir at low temperature to form a hydrolyzed silane mixture. The low-temperature stirring temperature is 4℃, the stirring speed is 135rpm, and the stirring time is 1h.

[0042] After uniformly stirring the nano-SiO2 / silicone rubber matrix, hydrolyzed silane mixture, and bismaleimide (BMI) from step S2, spray it onto the surface of the thin-walled metal radiation layer in step S3, pre-curing to form the bottom layer. The pre-curing temperature is 80℃, the pre-curing time is 10 min, and the bottom layer thickness is 15 μm. Adjust the phenyltrimethoxysilane content of the hydrolyzed silane mixture in the spraying solution, keeping the other components the same as the bottom layer, and spray it onto the bottom layer surface. Pre-curing to form the middle layer, the pre-curing temperature is 80℃, the pre-curing time is 10 min, and the middle layer thickness is 20 μm. Adjust the phenyltrimethoxysilane and bismaleimide content of the hydrolyzed silane mixture in the spraying solution, spray it onto the middle layer surface, and pre-curing to form the top layer, the pre-curing temperature is 80℃, the pre-curing time is 10 min, and the top layer thickness is 15 μm. The bottom layer, middle layer, and top layer... The content of phenyltrimethoxysilane in the middle layer and the surface layer increases sequentially, with the bismaleimide content in the surface layer being lower than that in the bottom layer. Specifically: in the bottom layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.5, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 3 wt% of the nano-SiO2 / silicone rubber matrix; in the middle layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.5, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 5 wt% of the nano-SiO2 / silicone rubber matrix; in the surface layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.3, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 8 wt% of the nano-SiO2 / silicone rubber matrix.

[0043] Finally, gradient temperature curing and annealing are performed to obtain a thin-walled metallic radiation layer with a sprayed silicon-based coating. The gradient temperature curing is as follows: the sprayed thin-walled metallic radiation layer is placed in an oven and heated to 80°C at a rate of 5°C / min and held for 30 min, then heated to 120°C at a rate of 3.5°C / min and held for 1 h, and finally heated to 180°C at a rate of 3.5°C / min and held for 2 h. The annealing is as follows: after curing, the temperature is cooled to 60°C with the oven temperature and held for 2 h, and then cooled to room temperature at a rate of 0.7°C / min.

[0044] Step S5, Preparation of high temperature resistant insulation layer: First, arrange 7 layers of aerogel insulation material from top to bottom, then wrap the arranged 7 layers of aerogel insulation material with fiber cloth material, and finally connect the wrapped material with high temperature fiber suture thread in a V-shape to obtain the high temperature resistant insulation layer.

[0045] Step S6, Preparation of thermal protection components: The high-temperature resistant heat insulation layer from step S5 is placed on the side of the thin-walled metal radiation layer away from the silicon-based coating, and the high-temperature resistant heat insulation layer is covered by bending the side of the thin-walled metal radiation layer. The inner side of the thin-walled metal radiation layer (i.e. the side away from the silicon-based coating) is connected to the high-temperature resistant heat insulation layer by pre-coating with an adhesive (the adhesive can be silicone rubber).

[0046] Example 3: A high-temperature resistant semi-flexible thermal protection component comprises, from top to bottom, a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer is composed of five layers of aerogel insulation material, wrapped with fiber cloth, and finally sewn together with high-temperature fiber stitching. The fiber cloth is made of glass fiber cloth, and the aerogel insulation material is made of glass fiber reinforced aerogel. The thickness of the fiber cloth is 0.2 mm, and the thickness of a single layer of aerogel material is 2 mm. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thin-walled metal radiant layer is made of Ti foil and is sequentially subjected to plasma etching, anodizing, and immersion in 3-isocyanate propyltrimethoxysilane. The thickness of the thin-walled metal radiant layer is 0.15 mm. The thickness of the bent edge of the thin-walled metal radiant layer is greater than that of the high-temperature resistant insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature resistant insulation layer; the thickness of the air gap is 1 mm; the outer ring of the thin-walled metal radiant layer is bent to wrap around the side of the high-temperature resistant insulation layer, and the width of the protrusion on the back of the high-temperature resistant insulation layer is 100 mm. A silicon-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature resistant insulation layer. The silicon-based coating includes a silicone rubber matrix, phenyltrimethoxysilane, KH560 (γ-glycidyl etheroxypropyltrimethoxysilane), bismaleimide, and nano-SiO2 particles. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%, and the nano-SiO2 particles have a particle size of 50 nm; the thickness of the silicon-based coating is 70 μm.

[0047] A method for preparing a high-temperature resistant semi-flexible thermal protection component, comprising: Step S1: Pretreatment of thin-walled metal radiation layer: First, ultrasonically clean the thin-walled metal radiation layer with anhydrous ethanol for 17 minutes, and then vacuum dry the cleaned thin-walled metal radiation layer at a temperature of 70℃ for 1.3 hours to remove oil stains from the surface of the thin-walled metal radiation layer.

[0048] The thin-walled metal radiant layer was then subjected to plasma etching and anodizing in sequence. The plasma etching was performed using argon gas at a power of 150W, a flow rate of 22sccm, a vacuum of 5.5Pa, and an etching time of 5min. The anodizing was performed using the plasma-etched thin-walled metal radiant layer as the anode and graphite as the cathode, with 0.5mol / L sulfuric acid solution as the electrolyte, and oxidation was carried out at a DC voltage of 11V for 12min.

[0049] Step S2, Preparation of Silicon-based Coating Base Solution: First, disperse nano-SiO2 particles in anhydrous toluene, and add hydroxyl-terminated polymethylphenylsiloxane (molecular weight 5000-10000). The mass-to-volume ratio of nano-SiO2 particles, anhydrous toluene, and hydroxyl-terminated polymethylphenylsiloxane is 10.5g:105mL:5.5g. The reaction is carried out under nitrogen protection at 85℃ for 3.5 hours. After centrifugation and drying, the specific centrifugation process is as follows: first, centrifuge at 10000 rpm for 15 minutes using a high-speed centrifuge. The centrifuged and coated nano-SiO2 particles were then placed in a vacuum drying oven and dried at 80℃ for 2 hours. The coated nano-SiO2 particles and KH560 were added to a high-pressure reactor and a silicone rubber matrix was injected. The mass ratio of the coated nano-SiO2 particles, KH560, and silicone rubber matrix was 5.5:0.3:52. After sealing, CO2 was introduced to the critical state, which was 31.1℃ and 7.38MPa. The mixture was stirred evenly for 32 minutes. After depressurization, a uniformly dispersed nano-SiO2 / silicone rubber matrix was obtained.

[0050] Step S3, Thin-walled metal radiation layer treatment: Immerse the pretreated thin-walled metal radiation layer from step S1 in 3-isocyanate propyltrimethoxysilane, let it stand at room temperature for 12 minutes, then remove it and dry it at 85°C for 5 minutes.

[0051] Step S4, Silicon-based coating spraying: First, dissolve KH560 and phenyltrimethoxysilane in deionized water containing acetic acid. The mass-to-volume ratio of KH560, phenyltrimethoxysilane and deionized water containing acetic acid is 2.2g:5.2g:52mL, and the acetic acid content is 0.12wt%. Stir at low temperature to form a hydrolyzed silane mixture. The low temperature stirring temperature is 5℃, the stirring speed is 150rpm, and the stirring time is 0.8h.

[0052] After uniformly stirring the nano-SiO2 / silicone rubber matrix, hydrolyzed silane mixture, and bismaleimide (BMI) from step S2, spray it onto the surface of the thin-walled metal radiation layer in step S3, pre-curing to form the bottom layer at a temperature of 85℃ for 8 minutes, resulting in a bottom layer thickness of 20 μm. Adjust the phenyltrimethoxysilane content of the hydrolyzed silane mixture in the spray solution, keeping the other components the same as the bottom layer, and spray it onto the bottom layer surface. Pre-curing to form the middle layer at a temperature of 85℃ for 8 minutes, resulting in a middle layer thickness of 30 μm. Adjust the phenyltrimethoxysilane and bismaleimide content of the hydrolyzed silane mixture in the spray solution, spray it onto the middle layer surface, and pre-curing to form the top layer at a temperature of 85℃ for 8 minutes, resulting in a top layer thickness of 20 μm. The benzene content of the bottom layer, middle layer, and top layer... The content of phenyltrimethoxysilane increases sequentially, with the amount of bismaleimide in the surface layer being lower than that in the bottom layer. Specifically: in the bottom layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.55, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 3.5 wt% of the nano-SiO2 / silicone rubber matrix; in the middle layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.55, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 5.5 wt% of the nano-SiO2 / silicone rubber matrix; in the surface layer, the mass ratio of nano-SiO2 / silicone rubber matrix to bismaleimide is 100:0.35, and the content of phenyltrimethoxysilane in the hydrolyzed silane mixture accounts for 8.5 wt% of the nano-SiO2 / silicone rubber matrix.

[0053] Finally, gradient temperature curing and annealing are performed to obtain a thin-walled metallic radiation layer with a sprayed silicon-based coating. The gradient temperature curing is as follows: the sprayed thin-walled metallic radiation layer is placed in an oven and heated to 85°C at a rate of 6°C / min and held for 28 min, then heated to 125°C at a rate of 4°C / min and held for 0.8 h, and finally heated to 185°C at a rate of 4°C / min and held for 1.8 h. The annealing is as follows: after curing, the temperature is cooled to 62°C with the oven temperature and held for 1.8 h, and then cooled to room temperature at a rate of 1°C / min.

[0054] Step S5, Preparation of high-temperature heat insulation layer: First, arrange 5 layers of aerogel heat insulation material from top to bottom (the performance of the aerogel heat insulation material can be set to decrease sequentially according to the direction of the heat source, i.e., place the high-temperature section aerogel heat insulation material near the heat source, and then place the medium-temperature section or low-temperature section aerogel heat insulation material in sequence). Then, wrap the arranged 5 layers of aerogel heat insulation material with fiber cloth material. Finally, connect the wrapped material with high-temperature fiber suture thread in a V-shape to obtain the high-temperature heat insulation layer.

[0055] Step S6, Preparation of thermal protection components: The high-temperature resistant heat insulation layer from step S5 is placed on the side of the thin-walled metal radiation layer away from the silicon-based coating, and the high-temperature resistant heat insulation layer is covered by bending the side of the thin-walled metal radiation layer. The inner side of the thin-walled metal radiation layer (i.e. the side away from the silicon-based coating) is connected to the high-temperature resistant heat insulation layer by pre-coating with an adhesive (the adhesive can be silicone rubber).

[0056] Comparative Example 1: A high-temperature resistant semi-flexible thermal protection component comprises, from top to bottom, a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer consists of seven layers of aerogel insulation material stacked together, wrapped with fiber cloth, and finally sewn together with high-temperature fiber stitching. The fiber cloth material is basalt fiber cloth, and the aerogel insulation material is basalt fiber reinforced aerogel material. The thickness of the fiber cloth material is 0.15 mm, and the thickness of a single layer of aerogel material is 1.2 mm. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thin-walled metal radiant layer is made of Ti foil and is subjected to plasma etching and anodizing in sequence. The thickness of the thin-walled metal radiant layer is 0.1 mm. The thickness of the bent edge of the thin-walled metal radiant layer is greater than that of the high-temperature resistant insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature resistant insulation layer; the thickness of the air gap is 0.7 mm; the outer ring of the thin-walled metal radiant layer is bent to wrap around the side of the high-temperature resistant insulation layer, and the width of the protrusion on the back of the high-temperature resistant insulation layer is 75 mm. A silicon-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature resistant insulation layer. The silicon-based coating includes a silicone rubber matrix, phenyltrimethoxysilane, KH560 (γ-glycidyl etheroxypropyltrimethoxysilane), bismaleimide, and nano-SiO2 particles. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%, and the nano-SiO2 particles have a particle size of 35 nm; the thickness of the silicon-based coating is 50 μm.

[0057] The preparation method is described in Example 2.

[0058] Comparative Example 2: A high-temperature resistant semi-flexible thermal protection component comprises, from top to bottom, a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer consists of seven layers of aerogel insulation material stacked together, wrapped with fiber cloth, and finally sewn together with high-temperature fiber stitching. The fiber cloth material is basalt fiber cloth, and the aerogel insulation material is basalt fiber reinforced aerogel material. The thickness of the fiber cloth material is 0.15 mm, and the thickness of a single layer of aerogel material is 1.2 mm. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thin-walled metal radiant layer is made of Ti foil and is sequentially subjected to plasma etching, anodizing, and immersion in 3-isocyanate propyltrimethoxysilane. The thickness of the thin-walled metal radiant layer is 0.1 mm. The thickness of the bent edge of the thin-walled metal radiant layer is greater than that of the high-temperature resistant insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature resistant insulation layer; the thickness of the air gap is 0.7 mm; the outer ring of the thin-walled metal radiant layer is bent to wrap around the side of the high-temperature resistant insulation layer, and the width of the protrusion on the back of the high-temperature resistant insulation layer is 75 mm. A silicon-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature resistant insulation layer. The silicon-based coating includes a silicone rubber matrix, KH560 (γ-glycidyl etheroxypropyltrimethoxysilane), bismaleimide, and nano-SiO2 particles. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%, and the nano-SiO2 particles have a particle size of 35 nm; the thickness of the silicon-based coating is 50 μm.

[0059] The preparation method is described in Example 2.

[0060] Comparative Example 3: A high-temperature resistant semi-flexible thermal protection component comprises, from top to bottom, a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer consists of seven layers of aerogel insulation material stacked together, wrapped with fiber cloth, and finally sewn together with high-temperature fiber stitching. The fiber cloth material is basalt fiber cloth, and the aerogel insulation material is basalt fiber reinforced aerogel material. The thickness of the fiber cloth material is 0.15 mm, and the thickness of a single layer of aerogel material is 1.2 mm. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thin-walled metal radiant layer is made of Ti foil and is sequentially subjected to plasma etching, anodizing, and immersion in 3-isocyanate propyltrimethoxysilane. The thickness of the thin-walled metal radiant layer is 0.1 mm. The thickness of the bent edge of the thin-walled metal radiant layer is greater than that of the high-temperature insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature insulation layer; the thickness of the air gap is 0.7 mm; the outer ring of the thin-walled metal radiant layer is bent to wrap around the side of the high-temperature insulation layer, and the width of the protrusion on the back of the high-temperature insulation layer is 75 mm. A silicon-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature insulation layer. The silicon-based coating includes a silicone rubber matrix, phenyltrimethoxysilane, bismaleimide, and nano-SiO2 particles. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%, and the nano-SiO2 particles have a particle size of 35 nm; the thickness of the silicon-based coating is 50 μm.

[0061] The preparation method is described in Example 2.

[0062] Comparative Example 4: A high-temperature resistant semi-flexible thermal protection component comprises, from top to bottom, a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer consists of seven layers of aerogel insulation material stacked together, wrapped with fiber cloth, and finally sewn together with high-temperature fiber stitching. The fiber cloth material is basalt fiber cloth, and the aerogel insulation material is basalt fiber reinforced aerogel material. The thickness of the fiber cloth material is 0.15 mm, and the thickness of a single layer of aerogel material is 1.2 mm. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thin-walled metal radiant layer is made of Ti foil and is sequentially subjected to plasma etching, anodizing, and immersion in 3-isocyanate propyltrimethoxysilane. The thickness of the thin-walled metal radiant layer is 0.1 mm. The thickness of the bent edge of the thin-walled metal radiant layer is greater than that of the high-temperature resistant insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature resistant insulation layer; the thickness of the air gap is 0.7 mm; the outer ring of the thin-walled metal radiant layer is bent to wrap around the side of the high-temperature resistant insulation layer, and the width of the protrusion on the back of the high-temperature resistant insulation layer is 75 mm. A silicone-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature resistant insulation layer. The silicone-based coating includes a silicone rubber matrix, phenyltrimethoxysilane, KH560 (γ-glycidyl etheroxypropyltrimethoxysilane), and bismaleic anhydride. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%; the thickness of the silicone-based coating is 50 μm.

[0063] The preparation method is described in Example 2.

[0064] Comparative Example 5: A high-temperature resistant semi-flexible thermal protection component comprises, from top to bottom, a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer consists of seven layers of aerogel insulation material stacked together, wrapped with fiber cloth, and finally sewn together with high-temperature fiber stitching. The fiber cloth material is basalt fiber cloth, and the aerogel insulation material is basalt fiber reinforced aerogel material. The thickness of the fiber cloth material is 0.15 mm, and the thickness of a single layer of aerogel material is 1.2 mm. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thin-walled metal radiant layer is made of Ti foil and is sequentially subjected to plasma etching, anodizing, and immersion in 3-isocyanate propyltrimethoxysilane. The thickness of the thin-walled metal radiant layer is 0.1 mm. The thickness of the bent edge of the thin-walled metal radiant layer is greater than that of the high-temperature resistant insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature resistant insulation layer; the thickness of the air gap is 0.7 mm; the outer ring of the thin-walled metal radiant layer is bent to wrap around the side of the high-temperature resistant insulation layer, and the width of the protrusion on the back of the high-temperature resistant insulation layer is 75 mm. A silicon-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature resistant insulation layer. The silicon-based coating includes a silicone rubber matrix, phenyltrimethoxysilane, KH560 (γ-glycidoxypropyltrimethoxysilane), and nano-SiO2 particles. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%, and the nano-SiO2 particles have a particle size of 35 nm; the thickness of the silicon-based coating is 50 μm.

[0065] The preparation method is described in Example 2.

[0066] The thermal insulation performance and multiple bending tests (10 consecutive bends) of the thermal protection components prepared in Examples 1-3 and Comparative Examples 1-5 were conducted respectively. The test results are shown in the table below:

[0067] As can be seen from the table above, the thermal protection component prepared by the method of the present invention has excellent thermal insulation performance, and the bonding strength between the silicon-based coating and the thin-walled metal radiation layer is high and the conformability is good. It can still maintain excellent thermal insulation performance after multiple bending and will not have problems such as cracks or peeling.

Claims

1. A high-temperature resistant semi-flexible thermal protection component, characterized in that: From top to bottom, it includes a silicon-based coating, a thin-walled metal radiant layer, and a high-temperature resistant insulation layer. The high-temperature resistant insulation layer is made of multiple layers of aerogel insulation material, wrapped with fiber cloth, and finally sewn together with high-temperature fiber stitching. The front of the thin-walled metal radiant layer corresponds to the high-temperature resistant insulation layer, and its outer ring is bent to wrap the sides of the high-temperature resistant insulation layer. The thickness of the bent edge of the thin-walled metal radiant layer is higher than the thickness of the high-temperature resistant insulation layer, forming an air gap between the thin-walled metal radiant layer and the high-temperature resistant insulation layer. The silicon-based coating is uniformly sprayed on the surface of the thin-walled metal radiant layer away from the high-temperature resistant insulation layer. The silicon-based coating includes a silicone rubber matrix, phenyltrimethoxysilane, KH560, bismaleimide, and nano-SiO2 particles. The silicone rubber matrix is ​​made of methylphenyl silicone rubber with a phenyl content of 15%, and the nano-SiO2 particles have a particle size of 20-50 nm. The thin-walled metal radiation layer is made of Ti foil and is sequentially subjected to plasma etching, anodizing, and immersion in 3-isocyanate propyltrimethoxysilane.

2. The high-temperature resistant semi-flexible thermal protection component according to claim 1, characterized in that: The thickness of the silicon-based coating is 30–70 μm.

3. The high-temperature resistant semi-flexible thermal protection component according to claim 2, characterized in that: The thickness of the thin-walled metal radiation layer is 0.05–0.15 mm.

4. The high-temperature resistant semi-flexible thermal protection component according to claim 3, characterized in that: The thickness of the air interlayer is 0.5 to 1 mm; the outer ring of the thin-walled metal radiation layer is bent to wrap around the side of the high-temperature insulation layer, and the width of the protrusion on the back of the high-temperature insulation layer is 50 to 100 mm.

5. A high-temperature resistant semi-flexible thermal protection component according to claim 3, characterized in that: The fiber cloth material is either basalt fiber cloth or glass fiber cloth, and the aerogel insulation material is at least one of glass fiber reinforced aerogel material, basalt fiber reinforced aerogel material, and alumina fiber reinforced aerogel material; the thickness of the fiber cloth material is 0.1-0.2 mm, and the thickness of the single-layer aerogel material is 0.5-2 mm.

6. A method for preparing a high-temperature resistant semi-flexible thermal protection component according to any one of claims 3 to 5, characterized in that: include: Step S1: Pretreatment of thin-walled metal radiation layer: First, clean and vacuum dry the thin-walled metal radiation layer to remove oil stains from its surface. The thin-walled metal radiation layer is then subjected to plasma etching and anodizing in sequence. Step S2, Preparation of Silicon-based Coating Base Solution: First, disperse nano-SiO2 particles in anhydrous toluene and add hydroxyl-terminated polymethylphenylsiloxane. Under nitrogen protection, carry out a reflux reaction. After centrifugation and drying, add the coated nano-SiO2 particles and KH560 to a high-pressure reactor and inject the silicone rubber matrix. After sealing, introduce CO2 to the critical state, stir evenly, and after depressurization, obtain a uniformly dispersed nano-SiO2 / silicone rubber matrix. Step S3, Thin-walled metal radiation layer treatment: Immerse the pretreated thin-walled metal radiation layer from step S1 in 3-isocyanate propyltrimethoxysilane, let it stand at room temperature for a period of time, and then take it out and dry it. Step S4, Silicon-based Coating Spraying: First, dissolve KH560 and phenyltrimethoxysilane in deionized water containing acetic acid, and stir at low temperature to form a hydrolyzed silane mixture; take the nano-SiO2 / silicone rubber matrix, hydrolyzed silane mixture and bismaleimide from step S2, stir evenly, and spray it onto the surface of the thin-walled metal radiation layer in step S3, and pre-cur it to form the bottom layer; adjust the phenyltrimethoxysilane content of the hydrolyzed silane mixture in the spraying solution, with the other components the same as the bottom layer, and spray it onto the bottom layer surface, and pre-cur it to form the middle layer; adjust the phenyltrimethoxysilane and bismaleimide content of the hydrolyzed silane mixture in the spraying solution, spray it onto the middle layer surface, and pre-cur it to form the top layer; finally, perform gradient temperature curing and annealing to obtain the thin-walled metal radiation layer with sprayed silicon-based coating; Step S5, Preparation of high temperature resistant insulation layer: First, arrange the multi-layer aerogel insulation material from top to bottom, then wrap the arranged multi-layer aerogel insulation material with fiber cloth material, and finally connect the wrapped material with high temperature fiber suture thread in a V-shape to obtain the high temperature resistant insulation layer. Step S6, Preparation of thermal protection components: The high-temperature resistant heat insulation layer from step S5 is placed on the side of the thin-walled metal radiation layer away from the silicon-based coating, and the high-temperature resistant heat insulation layer is covered by bending the side of the thin-walled metal radiation layer. The inner side of the thin-walled metal radiation layer is connected to the high-temperature resistant heat insulation layer by pre-coating with an adhesive.

7. The method for preparing a high-temperature resistant semi-flexible thermal protection component according to claim 6, characterized in that: The cleaning process in step S1 specifically involves: ultrasonic cleaning with anhydrous ethanol for 13–17 min; and vacuum drying at a temperature of 60–70 °C for 1.3–1.7 h.

8. The method for preparing a high-temperature resistant semi-flexible thermal protection component according to claim 6, characterized in that: The plasma etching in step S1 specifically involves: using argon gas for plasma etching, with a power of 100-150W, an argon gas flow rate of 18-22 sccm, a vacuum degree of 4.5-5.5 Pa, and an etching time of 5-8 min; the anodic oxidation specifically involves: using the plasma-etched thin-walled metal radiation layer as the anode and graphite as the cathode, using a 0.5 mol / L sulfuric acid solution as the electrolyte, and oxidizing for 12-18 min at a DC voltage of 9-11 V.

9. The method for preparing a high-temperature resistant semi-flexible thermal protection component according to claim 6, characterized in that: In step S3, the resting time is 8-12 minutes, the drying temperature is 75-85℃, and the drying time is 5-7 minutes.

10. The method for preparing a high-temperature resistant semi-flexible thermal protection component according to claim 6, characterized in that: The gradient temperature curing in step S4 specifically involves: placing the sprayed thin-walled metal radiation layer in an oven, heating it to 75-85°C at a rate of 4-6°C / min and holding it for 28-32 minutes, then heating it to 115-125°C at a rate of 3-4°C / min and holding it for 0.8-1.2 hours, and finally heating it to 175-185°C at a rate of 3-4°C / min and holding it for 1.8-2.2 hours; the annealing specifically involves: cooling it to 58-62°C after curing and holding it for 1.8-2.2 hours, then cooling it to room temperature at a rate of 0.5-1°C / min.

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