Multi-system powder enhanced thermal protection damping coating and preparation method thereof

Abstract

The invention belongs to the technical field of light thermal insulation materials, and particularly relates to a multi-system powder enhanced thermal protection damping coating and a preparation method thereof. Comprising the steps that the surface of the thin-wall component is pretreated, a waterborne polyurethane solution is sprayed, and a polyurethane base body layer firmly attached to a substrate is obtained after vacuum drying; spraying a silane coupling agent on the surface of the polyurethane matrix layer; carrying out alkali washing treatment on the nano performance enhancing powder, drying to obtain hydroxylated nano powder, and spraying the hydroxylated nano powder to the surface of the treated polyurethane matrix layer to form a powder enhancing layer; the waterborne polyurethane solution is sprayed on the surface of the powder enhancement layer again to form a covering layer, and the powder enhancement layer is wrapped in the covering layer; and the sprayed component is subjected to vacuum drying, and the composite coating with the structure of the polyurethane base body layer, the powder enhancement layer and the polyurethane covering layer is obtained. The coating has a high damping effect, the damping effect of the structural part is effectively achieved, and the quality of the structural part cannot be remarkably improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of light thermal insulation materials, and particularly relates to a multi-system powder enhanced thermal protection and vibration reduction coating and a preparation method thereof. BACKGROUND

[0002] To meet the extreme pursuit of high thrust-to-weight ratio and fuel efficiency of new generation of aviation equipment, thin-walled components taking light metal and composite material as the core are widely used in key parts of advanced aircraft and aero-engines. However, such thin-walled structures need to continuously withstand the combined action of high temperature, wideband vibration and corrosive medium erosion in the service process. Under the harsh conditions of thermal-mechanical-chemical multi-field coupling, the components face a series of severe challenges such as high-temperature failure, stiffness degradation, aggravated vibration fatigue damage and surface erosion aging, which seriously restrict their service safety and life.

[0003] Advanced coating technology is one of the key means to improve the performance and service life of such thin-walled components. By constructing a functional coating on the surface of the component, it can provide overall protection such as thermal protection, vibration reduction and corrosion resistance without changing the structure size, and has the advantages of flexible process, on-site operation and low maintenance cost. However, the coating materials widely used at present are mostly single-layer single-system structures, and the functions are relatively single. For example, traditional thermal protection coatings focus on heat insulation, but have poor damping performance and are easy to crack under vibration; while conventional vibration reduction coatings are difficult to withstand high temperature. This functional split makes it difficult for existing coatings to provide coordinated protection for components in complex thermal-vibration coupled environments, and cannot meet the requirements of modern aerospace equipment for high performance and high reliability.

[0004] The patent "Method for in-situ growth of large-thickness high-temperature-resistant / heat-insulating / radiation-heat-dissipating integrated thermal protection coating with multi-level gradient pore structure on thin-walled metal surface", publication number CN119411198A, publication date February 11, 2025, uses a micro-arc oxidation process that has very high requirements for electrolyte composition and electrical parameter control, and the process is complex and difficult to industrialize on a large scale. In addition, the multi-level gradient pore coating structure designed by it needs to be further verified in terms of thermal-vibration resistance and mechanical strength at high temperature.

[0005] The patent "Ultrahigh-temperature thermal protection powder coating, ultrahigh-temperature thermal protection coating, and preparation method and application thereof", publication number CN119410176A, publication date February 11, 2025, improves the ablation resistance of the coating by adding metal carbide to the transition metal boride and silicon carbide composite coating. However, the preparation process of the ultrahigh-temperature thermal protection powder coating involves spray drying and induction plasma spheroidization, which has high equipment cost and complex operation. In addition, although the ablation resistance of the coating is improved to a certain extent, its oxidation resistance in a thermal environment is not clear.

[0006] Patent "High-reflective heat protection coating and its preparation method", publication number CN120666283A, publication date September 19, 2025, uses LSTN0.125 ceramic powder with high reflectivity as coating raw material, but the coating corresponding powder material preparation process is complex, involving ball milling, spray granulation, pre-sintering and other multi-step operations, low production efficiency.

[0007] Patent "Reproducible ultra-high temperature heat protection coating", publication number CN119020718A, publication date November 26, 2024, uses double powder feeding atmospheric plasma spraying technology to prepare gradient structure coating. However, the double powder feeding process has high requirements for equipment precision and operator skills, and the process is complex and difficult to industrialize on a large scale, and its long-term stability at extremely high temperature still needs further verification. In addition, this method is mainly aimed at ceramic matrix composites, and its applicability to thin-walled components composed of metals or resins is insufficient.

[0008] Patent "High-temperature-resistant heat protection coating reinforced composite material and its preparation method", publication number CN120588527A, publication date September 5, 2025, by spraying functional materials and reinforcing agents on the fiber web, a coating material with high thermal insulation performance is prepared. However, the preparation process of the coating of this method involves ball milling, spray granulation, needling, sol-gel and other multi-step operations, and the process is complex and costly. Secondly, although the thermal insulation performance of the coating is improved to a certain extent, the mechanical strength and erosion resistance at high temperature are not considered; in addition, this method is mainly applied to the field of light thermal insulation materials, and its applicability to other fields is low.

[0009] Patent "Nanometer structure heat protection coating resistant to long-time high temperature oxidation and its preparation method", publication number CN119797917A, publication date April 11, 2025, uses spray granulation and solid phase sintering technology to prepare nanometer structure spherical powder. However, the preparation process of nanometer structure powder is complex, involving ball milling, spray granulation, solid phase sintering and other multi-step operations, low production efficiency and high cost. Secondly, the thermal shock resistance and mechanical strength of the coating material at extremely high temperature still need further verification.

[0010] Patent "Heat protection coating, its preparation method and application", publication number CN119736572A, publication date April 1, 2025, by introducing nano-particle reinforcement phase, the crack resistance and oxidation resistance of the coating are improved, but the preparation process of the coating involves multi-step spraying and complex material ratio, and the performance improvement of the coating is mainly concentrated in the aspects of oxidation resistance and crack resistance, and the thermal insulation performance and vibration resistance at high temperature are not considered.

[0011] Patent "Nuclear radiation resistant heat insulation protective coating for steam pipeline and preparation method thereof", publication number CN119220173B, publication date December 31, 2024, uses the combination of organic coating and inorganic coating to improve the nuclear radiation resistance of the coating. However, this coating is mainly used for thermal protection of nuclear industry steam pipelines and does not consider the thermal shock resistance.

[0012] Despite numerous research and development attempts in the prior art on thermal protection coatings, the following common problems still exist: Complex manufacturing process: Most solutions rely on processes such as micro-arc oxidation, plasma spraying, spray granulation combined with high-temperature sintering, which have high equipment requirements, precise parameter control, high energy consumption, and are difficult to scale up.

[0013] Narrow substrate applicability: Many processes (such as thermal spraying) are mainly designed for metal substrates and are not suitable for heat-sensitive thin-walled components such as fiber-reinforced resin matrix composites, which can easily damage the substrate.

[0014] Insufficient comprehensive performance verification: Existing technologies focus on improving a single performance of the coating (such as ablation resistance, oxidation resistance), lacking systematic evaluation and verification of the coating's thermal shock resistance, heat insulation and vibration reduction synergy, and long-term environmental durability under simulated real service conditions.

[0015] In summary, developing a new multifunctional coating system with a relatively simple process, suitable for various substrates (metal and composite materials), and providing effective thermal protection and vibration reduction performance under thermal shock service conditions has become a technical bottleneck that needs to be broken through in the field. SUMMARY

[0016] To solve the problems in the prior art, the present application provides a multi-system powder enhanced thermal protection and vibration reduction coating and a preparation method thereof.

[0017] The technical solution of the present application is: The present application discloses a preparation method of a multi-system powder enhanced thermal protection and vibration reduction coating, comprising the following steps: S1, cleaning and silane coupling agent spraying pretreatment are performed on the surface of the thin-walled component to introduce coupling functional groups; S2, a water-based polyurethane solution is sprayed on the surface of the pretreated thin-walled component to form a first polyurethane layer; S3, the thin-walled component with the first polyurethane layer sprayed thereon is subjected to vacuum drying to obtain a polyurethane matrix layer firmly attached to the substrate; S4, a silane coupling agent is sprayed on the surface of the polyurethane matrix layer; S5, the nano performance enhancing powder is subjected to alkali washing treatment to hydroxylate the surface, and after drying, hydroxylated nano powder is obtained; S6, spraying the hydroxylated nano-powder to the surface of the polyurethane substrate layer treated in S4 to form a powder-reinforced layer; S7, spraying the aqueous polyurethane solution again on the surface of the powder-reinforced layer to form a cover layer, and covering the powder-reinforced layer inside; S8, vacuum drying the sprayed component to obtain a composite coating with a three-layer structure of "polyurethane substrate layer-powder-reinforced layer-polyurethane cover layer".

[0018] Further, in the preparation method of the multi-system powder-reinforced thermal protection and vibration reduction coating, the thin-walled component includes one of a fiber-reinforced resin-based composite thin-walled component, a metal alloy thin-walled component, or a resin-based fabric thin-walled component.

[0019] Further, in the preparation method of the multi-system powder-reinforced thermal protection and vibration reduction coating, the nano-property enhanced powder is a surface-hydroxylated nano-ceramic powder or a nano-ceramic-based hybrid powder; the nano-ceramic powder is preferably a nano-α-Al2O3 powder, and the nano-ceramic-based hybrid powder is preferably a mixture of a nano-α-Al2O3 powder and a nano-Y2O3 powder.

[0020] Further, in the preparation method of the multi-system powder-reinforced thermal protection and vibration reduction coating, in S1 and S4, the silane coupling agent is selected from at least one of a zirconium aluminate coupling agent and an epoxy silane coupling agent.

[0021] Further, in the preparation method of the multi-system powder-reinforced thermal protection and vibration reduction coating, in S2 and S7, the aqueous polyurethane solution is selected from at least one of a low-VOC aqueous polyurethane, an aqueous touch oil resin, and Syntegra YF4000 PUD.

[0022] Further, in the preparation method of the multi-system powder-reinforced thermal protection and vibration reduction coating, in S3 and S8, the solution used in the alkali washing treatment is an NaOH aqueous solution; and the conditions for the vacuum drying are as follows: a temperature of 30-80°C, a vacuum degree of -0.1 MPa, and a time of not less than 24 hours.

[0023] Further, in the preparation method of the multi-system powder-reinforced thermal protection and vibration reduction coating, the method further includes a step S9 of repeating the operations of S4 to S8 at least once to construct a gradient composite coating structure with multiple powder-reinforced layers.

[0024] The application also discloses a multi-system powder-reinforced vibration reduction thermal protection coating prepared by the preparation method. a polyurethane substrate layer chemically bonded to the surface of the thin-walled component through the silane coupling agent; a powder reinforced layer chemically bonded with the polyurethane matrix layer by silane coupling agent and composed of hydroxylated nano powder; a polyurethane cover layer combined with and covering the surface of the powder reinforced layer.

[0025] Advantages and beneficial effects of the present application: 1. In the preparation method of the present application, the thermal protection effect is mainly provided by the nano performance enhanced powder with high temperature resistance, which has good thermal protection effect and low thermal conductivity. In the present application, the nano performance enhanced powder is placed in the middle layer of the coating, effectively solving the adhesion problem of the nano performance enhanced powder.

[0026] 2. In the preparation method of the present application, the polyurethane matrix layer, the structural part layer, the polyurethane matrix layer, the powder reinforced layer and the cover layer are combined with each other through coupling reaction, forming a multi-coating system, and the interface bonding problem between the layers of the coating and between the coating and the surface of the structural part is effectively solved through polyurethane coating, and the interface bonding force is improved.

[0027] 3. The preparation method of the present application has simple process, strong universality and easy-to-obtain raw materials, and does not need high-energy-consuming steps such as high-temperature sintering, so that a high-temperature-resistant thermal protection coating can be prepared on the surface of the material. The high-temperature-resistant thermal protection coating can utilize the thermal protection function and low thermal conductivity of the powder reinforced layer in the heat protection process, thereby significantly reducing the ablation rate and mass loss rate of the material. Moreover, the areal density and thickness of the coating can be flexibly designed and adjusted according to needs, which is suitable for large-scale industrial application.

[0028] 4. The multi-system powder reinforced thermal protection and vibration reduction coating of the present application has high damping effect, which can effectively realize the vibration reduction effect of the structural part without significantly increasing the mass of the structural part. This vibration reduction performance is mainly due to the energy dissipation caused by the inter-particle friction of the powder reinforced layer in the deformation process, and the energy dissipation caused by the viscoelastic deformation of the matrix layer also plays an important role. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Figure 1 is a model diagram of the surface coating of the T700 carbon fiber sheet sample in Example 1, in which 1 is the powder reinforced layer; 2 is the polyurethane cover layer; 3 is the surface of the T700 carbon fiber sheet sample; 4 is the silane coupling reaction layer; and 5 is the polyurethane matrix layer. Figure 2 Figure 2 is a sample diagram, in which (a) is a T700 carbon fiber sheet sample without coating; (b) is a T700 carbon fiber sheet sample coated with a double-layer polyurethane coating according to Comparative Example 1; (c) is a T700 carbon fiber sheet sample coated with a multi-system powder reinforced vibration reduction thermal protection coating according to Example 1; and (d) is a T700 carbon fiber sheet sample coated with a multi-system powder reinforced vibration reduction thermal protection coating according to Example 2. Figure 3 Temperature rising curve of T700 carbon fiber sheet sample coated with coating of Example 1, 2 and Comparative Example 1 and T700 carbon fiber sheet sample without coating at constant temperature; Figure 4 Infrared thermal imaging contrast of T700 carbon fiber sheet sample coated with coating of Example 1, 2 and Comparative Example 1 and T700 carbon fiber sheet sample without coating at constant temperature; wherein (a) is the infrared thermal imaging contrast after 30 minutes after the test starts; (b) is the infrared thermal imaging contrast after 31 minutes and 30 seconds after the test starts; (c) is the infrared thermal imaging contrast after 32 minutes after the test starts; (d) is the infrared thermal imaging contrast after 32 minutes and 30 seconds after the test starts; (e) is the infrared thermal imaging contrast after 33 minutes and 30 seconds after the test starts; (f) is the infrared thermal imaging contrast after 34 minutes after the test starts; (g) is the infrared thermal imaging contrast after 34 minutes and 30 seconds after the test starts; (h) is the infrared thermal imaging contrast after 35 minutes after the test starts; P1 in the figure is the infrared thermal imaging of T700 carbon fiber sheet sample without coating, P2 is the infrared thermal imaging of T700 carbon fiber sheet sample coated with multi-system powder enhanced damping thermal protection coating of Example 1, P3 is the infrared thermal imaging of T700 carbon fiber sheet sample coated with double-layer polyurethane coating of Comparative Example 1, and P4 is the infrared thermal imaging of T700 carbon fiber sheet sample coated with multi-system powder enhanced damping thermal protection coating of Example 2; Figure 5 Three-dimensional surface topography of T700 carbon fiber sheet sample coated with coating of Example 1; Figure 6 Two-dimensional super-depth microscopic image of T700 carbon fiber sheet sample coated with coating of Example 1; Figure 7 Time domain response curve contrast of T700 carbon fiber sheet sample coated with coating of Example 1 and T700 carbon fiber sheet sample without coating under random vibration; Figure 8 Frequency domain response curve contrast of T700 carbon fiber sheet sample coated with coating of Example 1 and T700 carbon fiber sheet sample without coating under random vibration; Figure 9 Power spectral density curve contrast of T700 carbon fiber sheet sample coated with coating of Example 1 and T700 carbon fiber sheet sample without coating under random vibration; Figure 10 Cross-sectional super-depth microscopic image of T700 carbon fiber sheet sample coated with coating of Example 3. DETAILED DESCRIPTION

[0030] The application will be further described in detail in connection with the drawings of the specification and the examples. It should be understood that the examples described herein are only used to explain the application and not to limit the application.

[0031] The purity of all raw materials of the application is not particularly limited, and the application preferably uses industrial pure or conventional purity used in the art.

[0032] The device used in the application is not particularly limited and uses the device commonly used in the art.

[0033] In the following examples, the aqueous polyurethane solution is selected from low VOC aqueous polyurethane, specifically F0413 type aqueous polyurethane from Shenzhen Jitian Chemical Co., Ltd.

[0034] The spraying sample used is a T700 carbon fiber sheet, and the interlayer adhesive matrix is an epoxy resin provided by Weihai Guangwei Composite Material Co., Ltd.

[0035] The epoxy silane coupling agent is used as the coupling reaction reagent, specifically 3-glycidyloxypropyl trimethoxysilane provided by Aladdin Biochemical Technology Co., Ltd.

[0036] The nano performance enhancing powder is selected from nano type Al2O3 powder and Y2O3 powder, and the nano type Al2O3 powder and Y2O3 powder used are provided by Aladdin Biochemical Technology Co., Ltd.

[0037] NaOH solution is used as the main solution for alkaline washing, and the NaOH solution used is provided by Aladdin Biochemical Technology Co., Ltd.

[0038] Example 1 The preparation method of the multi-system powder enhanced thermal protection and damping coating of the present embodiment comprises the following steps: S1, uniformly spraying the silane coupling agent on the surface of the T700 carbon fiber sheet to make it couple with the surface resin matrix.

[0039] S2, uniformly coating the aqueous polyurethane on the treated surface. Through interfacial coupling reaction, the polyurethane forms a layer of adhesive matrix layer, firmly adheres to the substrate, and enhances the surface adhesion strength.

[0040] S3, placing the sprayed sample in a vacuum drying oven with a temperature of 30°C and a vacuum degree of -0.1 Mpa for drying for 24 hours to obtain a sample with a polyurethane matrix layer.

[0041] S4, treating the surface of the T700 carbon fiber sheet sample with a polyurethane matrix layer with a silane coupling agent to enhance the interfacial compatibility.

[0042] S5, the nano-Al2O3 powder is placed in a beaker and washed with NaOH solution to introduce hydroxyl groups on the surface thereof.

[0043] S6, the NaOH solution is filtered off using filter paper, and the solid precipitate on the filter paper is left to stand and then dried at normal temperature and pressure to obtain the surface-hydroxylated nano α-Al2O3 powder.

[0044] S7, the surface-hydroxylated nano α-Al2O3 powder is sprayed on the surface of the T700 carbon fiber sheet sample having a polyurethane matrix layer treated with a silane coupling agent to form a powder-reinforced layer.

[0045] S8, a layer of water-based polyurethane, i.e., a polyurethane cover layer, is coated on the surface of the powder-reinforced layer to wrap the nano α-Al2O3 powder-reinforced layer.

[0046] S9, the coated T700 carbon fiber sheet sample after the entire spraying is placed in a vacuum drying oven at a temperature of 30°C and a vacuum degree of -0.1 Mpa for drying for 24 hours to obtain a T700 carbon fiber sheet sample having a composite coating of "polyurethane matrix layer-powder-reinforced layer-polyurethane cover layer" structure.

[0047] A model diagram of the composite coating having the "polyurethane matrix layer-powder-reinforced layer-polyurethane cover layer" structure is shown in Figure 1 , which includes a polyurethane matrix layer 5, a powder-reinforced layer 1 and a polyurethane cover layer 2 on the surface 3 of the T700 carbon fiber sheet sample, wherein the surface 3 of the T700 carbon fiber sheet sample and the surface of the polyurethane matrix layer 5 are silane coupling reaction layers 4 having coupling functional groups.

[0048] Comparative Example 1 This comparative example provides a preparation method of a T700 carbon fiber sheet sample coated with a double-layer polyurethane coating, which specifically includes the following steps: S1, a silane coupling agent is uniformly sprayed on the surface of the T700 carbon fiber sheet to couple with the resin matrix on the surface.

[0049] S2, the treated surface is uniformly coated with water-based polyurethane. Through interfacial coupling reaction, the polyurethane forms a cohesive matrix layer, which is firmly attached to the substrate and enhances the surface adhesion strength thereof.

[0050] S3, the sprayed sample is placed in a vacuum drying oven at a temperature of 30°C and a vacuum degree of -0.1 Mpa for drying for 24 hours to obtain a sample having a polyurethane matrix layer.

[0051] S4, the surface of the sample is further treated with a silane coupling agent.

[0052] S5, coating a layer of water-based polyurethane on the surface of the sample.

[0053] S6, drying the sample with the sprayed coating T700 carbon fiber sheet in a vacuum drying oven at a temperature of 30°C and a vacuum degree of -0.1 Mpa for 24 hours to obtain a T700 carbon fiber sheet sample with a double-layer polyurethane coating on the surface.

[0054] Example 2 The preparation method of the multi-system powder-reinforced thermal protection and vibration damping coating of the present embodiment includes the following steps: S1, uniformly spraying a silane coupling agent on the surface of the T700 carbon fiber sheet to couple with the surface resin matrix.

[0055] S2, uniformly coating water-based polyurethane on the treated surface. Through interfacial coupling reaction, the polyurethane forms a cohesive matrix layer, firmly adhering to the substrate and enhancing the surface adhesion strength.

[0056] S3, placing the sample after spraying in a vacuum drying oven at a temperature of 30°C and a vacuum degree of -0.1 Mpa for 24 hours to obtain a sample with a polyurethane collective layer.

[0057] S4, treating the surface of the T700 carbon fiber sheet with a polyurethane matrix with a silane coupling agent to enhance interfacial compatibility.

[0058] S5, placing nano-Al2O3 powder and nano-Y2O3 powder in a beaker in a ratio of 10:1, washing with NaOH solution to introduce hydroxyl groups on the surface.

[0059] S6, filtering out the NaOH solution using filter paper, and then drying the solid precipitate on the filter paper at normal temperature and pressure to obtain mixed nano-performance enhancing powder of surface-hydroxylated nano-α-Al2O3 powder and nano-Y2O3 powder.

[0060] S7, spraying the hydroxylated mixed nano-performance enhancing powder on the surface of the T700 carbon fiber sheet with a polyurethane matrix treated with a silane coupling agent using a sandblasting gun to form a powder-reinforced layer.

[0061] S8, coating a layer of water-based polyurethane, i.e., a polyurethane cover layer, on the surface of the powder-reinforced layer to wrap the mixed powder-reinforced layer.

[0062] S9, placing the T700 carbon fiber sheet sample with the entire sprayed coating in a vacuum drying oven at a temperature of 30°C and a vacuum degree of -0.1 Mpa for 24 hours. A T700 carbon fiber sheet sample with a composite coating of "polyurethane matrix layer-powder-reinforced layer-polyurethane cover layer" structure is obtained.

[0063] Example 3 The preparation method of the multi-system powder reinforced thermal protection and vibration damping coating of the present example comprises the following steps: S1, uniformly spray silane coupling agent on the surface of T700 carbon fiber sheet, so that it is coupled with the surface resin matrix.

[0064] S2, uniformly coat the treated surface with water-based polyurethane. Through interfacial coupling reaction, the polyurethane forms a layer of adhesive matrix layer, firmly adheres to the substrate, and enhances the surface adhesion strength.

[0065] S3, place the sprayed sample in a vacuum drying oven, with a temperature of 80°C and a vacuum degree of -0.1 Mpa, and dry for 24 hours to obtain a sample with a polyurethane collective layer.

[0066] S4, treat the surface of the T700 carbon fiber sheet sample with a polyurethane matrix layer with silane coupling agent to enhance the interfacial compatibility.

[0067] S5, place nano-Al2O3 powder in a beaker and wash it with NaOH solution to introduce hydroxyl groups on its surface.

[0068] S6, filter out the NaOH solution using filter paper, and then dry the solid precipitate on the filter paper at room temperature and normal pressure to obtain nano α-type Al2O3 powder with surface hydroxylation.

[0069] S7, spray the nano α-type Al2O3 powder with surface hydroxylation on the surface of the T700 carbon fiber sheet sample with a polyurethane matrix layer treated with silane coupling agent using a sandblasting gun to form a powder reinforced layer.

[0070] S8, coat a layer of water-based polyurethane, i.e. polyurethane covering layer, on the surface of the powder reinforced layer to wrap the nano α-type Al2O3 powder reinforced layer.

[0071] S9, place the coated T700 carbon fiber sheet sample after all spraying is completed in a vacuum drying oven, with a temperature of 80°C and a vacuum degree of -0.1 Mpa, and dry for 24 hours.

[0072] S10, repeat the deposition and coating cycle 5 times to prepare a T700 carbon fiber sheet sample with a composite coating of 5-layer structure.

[0073] Figure 10 The cross-sectional ultra-depth microscopic image of the sample prepared in Example 3 shows that the adhesion between the layers is good and there is no obvious delamination. Figure 10 It can be seen that the adhesion between the layers is good and there is no obvious delamination.

[0074] Figure 2The sample images show uncoated T700 carbon fiber sheet samples and T700 carbon fiber sheet samples coated with Examples 1, 2 and Comparative Example 1, wherein... Figure 2 a is an uncoated T700 carbon fiber sample. Figure 2 b is the T700 carbon fiber sample coated with Comparative Example 1. Figure 2 c represents the T700 carbon fiber sample coated in Example 1. Figure 2 d represents the T700 carbon fiber sample coated in Example 2. It can be seen that the coating has little effect on thickness and surface roughness.

[0075] Figure 3 The graphs show the temperature rise of T700 carbon fiber sheets coated with the coatings of Examples 1, 2, and Comparative Example 1, and the uncoated T700 carbon fiber sheets under isothermal conditions. Figure 3 It can be seen that the sample coated in Example 2 heated up the slowest, followed by the sample coated in Example 1, demonstrating the contribution of the nano-performance-enhancing powder to the thermal insulation performance of the coating. The sample coated in Comparative Example 1 showed a similar heating curve to the uncoated sample, proving that the pure polyurethane matrix does not possess thermal insulation capabilities. However, Example 2, proposed in this invention, showed a 19.8% temperature reduction under 200°C thermal radiation for 60 minutes compared to the uncoated sample, demonstrating the thermal insulation performance of the multi-system powder-reinforced vibration-damping thermal protective coating proposed in this invention.

[0076] The samples of Examples 1, 2 and Comparative Example 1 were subjected to tests on the thermal insulation performance, surface morphology and vibration damping performance of the coatings.

[0077] Thermal insulation performance testing: The testing equipment includes a heating platform and an infrared thermal imager. By adjusting the heating platform to a constant temperature and using the infrared thermal imager to capture the heating process of different samples, the thermal insulation performance of the coating is evaluated. Specific test results are as follows... Figure 4 , Figure 5 As shown.

[0078] from Figure 4 It can be seen that the samples coated in Examples 1 and 2 show darker colors in their infrared spectra under thermal radiation at 200°C, indicating lower temperature and thermal penetration efficiency. In contrast, the infrared spectra of Comparative Example 1 and the uncoated sample are lighter in color and show highlights, indicating higher temperature and thermal penetration efficiency. This comparison indirectly demonstrates the effectiveness of the coating proposed in this invention in thermal protection.

[0079] from Figure 5The three-dimensional surface morphology of the coating surface has many irregular protrusions with a maximum height of 230 μm. The protrusions can effectively enhance the mechanical anchoring effect of the coating, thereby improving the adhesion and facilitating the improvement of the anti-peeling performance of the coating in an impact and thermal cycle environment. The surface roughness of the coating meets most engineering requirements.

[0080] Surface morphology test: The test equipment includes an ultra-depth microscope, a workstation and corresponding software. The surface morphology of the coating is scanned by the ultra-depth microscope to evaluate the surface roughness of the coating. The specific test results are shown in Figure 6 .

[0081] From Figure 6 the two-dimensional ultra-depth microscopic image, the treated nano powder has good compatibility with the polyurethane matrix without obvious pores or other defects. The nano particles are uniformly and fully dispersed in the matrix without obvious agglomeration, which is very important for improving the comprehensive performance of the coating.

[0082] Vibration reduction performance test: The test equipment includes an electromagnetic vibration table, an LMS data acquisition instrument and an acceleration sensor. The vibration reduction contribution of the coating is evaluated by comparing the vibration response of the sample coated with the coating and the sample without the coating under random excitation. The specific test results are shown in Figure 7 , Figure 8 and Figure 9 . As shown in Figure 7 , the time-domain vibration response of the T700 carbon fiber sheet sample coated with the coating of embodiment 1 under random vibration is lower than that of the uncoated sample, which proves the vibration reduction performance of the multi-system powder enhanced vibration reduction thermal protection coating proposed in the present application. As shown in Figure 8 , the vibration response peak value of the T700 carbon fiber sheet sample coated with the coating of embodiment 1 is 34.8% lower than that of the uncoated sample, which proves the vibration reduction performance of the multi-system powder enhanced coating proposed in the present application. In addition, the peak frequency is smaller than that of the uncoated sample, which is due to the mass contribution of the multi-system powder enhanced vibration reduction thermal protection coating. As shown in Figure 9 , the vibration response peak value of the T700 carbon fiber sheet sample coated with the coating of embodiment 1 is 41.2% lower than that of the uncoated sample, which proves that the multi-system powder enhanced vibration reduction thermal protection coating proposed in the present application has excellent energy dissipation capacity.

Claims

1. A method of making a multi-system, powder-reinforced thermal protection and vibration-damping coating, characterized in that, The method comprises the following steps: S1, cleaning and silane coupling agent spraying pretreatment are performed on the surface of the thin-walled component to introduce coupling functional groups; S2, a water-based polyurethane solution is sprayed on the surface of the pretreated thin-walled component to form a first polyurethane layer; S3, the thin-walled component sprayed with the first polyurethane layer is subjected to vacuum drying to obtain a polyurethane matrix layer firmly attached to the substrate; S4, a silane coupling agent is sprayed on the surface of the polyurethane matrix layer; S5, the nano-property enhanced powder is subjected to alkali washing treatment to hydroxylate the surface, and the hydroxylated nano powder is obtained after drying; S6, the hydroxylated nano powder is sprayed on the surface of the polyurethane matrix layer treated in S4 to form a powder enhanced layer; S7, a water-based polyurethane solution is again sprayed on the surface of the powder enhanced layer to form a covering layer, and the powder enhanced layer is covered inside; S8, the component after spraying is subjected to vacuum drying to obtain a composite coating layer with a structure of "polyurethane matrix layer-powder enhanced layer-polyurethane covering layer".

2. A method of making a multi-system powder reinforced thermal protection and vibration damping coating according to claim 1, characterized in that, The thin-walled component comprises one of a fiber reinforced resin-based composite thin-walled component, a metal alloy thin-walled component, or a resin-based fabric thin-walled component.

3. The method of claim 1, wherein the multi-system powder enhanced thermal protection and vibration damping coating is prepared by, In S5, the nano-property enhanced powder is a nano ceramic powder or a nano ceramic-based hybrid powder with a hydroxylatable surface.

4. The method of claim 1, wherein the multi-system powder enhanced thermal protection and vibration damping coating is prepared by, In S1 and S4, the silane coupling agent is selected from at least one of a zirconium aluminate coupling agent and an epoxy silane coupling agent.

5. The method of claim 1, wherein the multi-system powder enhanced thermal protection and vibration damping coating is prepared by, In S2 and S7, the water-based polyurethane solution is selected from at least one of a low VOC water-based polyurethane, a water-based touch oil resin, and Syntegra YF4000 PUD.

6. The method of claim 1, wherein the multi-system powder enhanced thermal protection and vibration damping coating is prepared by, In S3 and S8, the solution used for the alkali washing treatment is an aqueous NaOH solution, and the conditions for the vacuum drying are a temperature of 30-80°C, a vacuum degree of -0.1 MPa, and a time of not less than 24 hours.

7. A method of making a multi-layered powder reinforced thermal protection and vibration damping coating according to any one of claims 1 to 6, characterized in that, The method further comprises a step S9 of repeating the operations of S4 to S8 at least once to construct a gradient composite coating structure with multiple powder enhanced layers.

8. A multi-system powder reinforced thermal protection coating prepared by the method of any one of claims 1-7, wherein, The coating is attached to the surface of the thin-walled component and comprises, from inside to outside, in sequence: a polyurethane matrix layer chemically bonded to the surface of the thin-walled component through a silane coupling agent; a powder enhanced layer chemically bonded to the polyurethane matrix layer through a silane coupling agent and composed of hydroxylated nano powder; a polyurethane covering layer combined with the surface of the powder enhanced layer and covering the same.

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