Lightweight high-pressure-resistant heat-insulating thermal protection structure and preparation method thereof

Abstract

The application discloses a kind of light high compression resistance heat insulation type heat protection structure in the technical field of composite product, comprising: aerogel heat insulation plate, including square box body, four corners of box body and center are equipped with boss, round hole is set on boss;Mixed powder, including aerogel powder and SiC powder, filled in the cavity formed between aerogel heat insulation plate boss and box body;Ceramic cylinder, filled in the round hole of boss;Carbon fiber reinforced resin matrix composite board, bonded on aerogel heat insulation plate, to seal the cavity of aerogel heat insulation plate, the application structure bears well, light in weight, excellent heat insulation effect, simple structure, by adopting gradient heat insulation material, effectively reduce the overall structure quality, while sample can withstand 800 DEG C high temperature heat test, Si3N4 ceramic cylinder in structure, can bear higher pressure load.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, and in particular to a heat-protective brick and its preparation method. Background Technology

[0002] Thermal protection structure design is one of the key technologies for realizing and advancing the development of hypersonic vehicles. As the requirements for flight duration of hypersonic vehicles continue to increase, the aerodynamic thermal environment of long duration and high heat flux brings new challenges to the thermal protection structure design of hypersonic vehicles.

[0003] Traditional aircraft have separate load-bearing and thermal protection structures. This type of structure has a large mass, requires thermal sealing between different materials, and poses a risk of phase separation due to differences in thermal expansion coefficients.

[0004] Throughout the design and manufacturing process of the space shuttle, researchers conducted extensive design work on the thermal protection system. They designed thermal protection structures of different materials as a type of insulated brick that could be laid out, and then installed on the surface of the space shuttle during use. This method offered ease of manufacturing, but the characteristics of insulated ceramic tiles resulted in their fragile and easily damaged appearance, limiting their ability to withstand very small loads. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a lightweight, high-compression-resistant, and heat-insulating thermal protection structure and its preparation method. The structure has good load-bearing capacity, light weight, excellent heat insulation effect, and simple structure. By using gradient heat insulation materials, the overall structural weight is effectively reduced. At the same time, the sample can withstand high-temperature thermal testing at 800℃. The Si3N4 ceramic cylinder in the structure can withstand higher pressure loads.

[0006] The objective of this invention is achieved as follows: a lightweight, high-compression-resistant, and heat-insulating thermal protection structure, comprising:

[0007] Aerogel insulation board includes a square box body, with protrusions at the four corners and the center of the box body, and round holes formed on the protrusions;

[0008] The mixed powder, including aerogel powder and SiC powder, is filled in the cavity formed between the aerogel insulation plate boss and the box body;

[0009] A ceramic cylinder is filled into the circular hole of the boss;

[0010] Carbon fiber reinforced resin-based composite board is bonded to aerogel insulation board to seal the cavity of the aerogel insulation board.

[0011] Furthermore, the aerogel insulation board is made of silica aerogel composite aluminum silicate insulation cotton.

[0012] Furthermore, the aerogel powder is selected from SiO2 aerogel powder.

[0013] Furthermore, the ceramic cylinder is a Si3N4 ceramic cylinder.

[0014] A method for preparing a lightweight, high-compression-resistant, and heat-insulating thermal protection structure includes the following steps:

[0015] Step 1) Fabricate aerogel insulation board. The raw material is silica aerogel composite aluminum silicate insulation cotton. It is processed into shape using a carving machine and wire cutting process and then set aside.

[0016] Step 2) Filling the mixed powder: Thoroughly mix the SiO2 aerogel powder and SiC powder for later use;

[0017] Step 3) Fabricate carbon fiber reinforced resin-based composite board. Use carbon fiber and resin as raw materials to prepare carbon fiber prepreg, which is then laid, cured in an autoclave, and cut for later use.

[0018] Step 4) Fabricate Si3N4 ceramic cylinders, process them using a surface grinder, and set them aside for later use;

[0019] Step 5) Sample assembly: First, fill the aerogel insulation board with a sufficient mass of aerogel mixed powder. Then, apply a ring of sealant around the aerogel insulation board. Adhere the carbon fiber reinforced resin-based composite board to the top of the aerogel insulation board and lightly press it with a heavy object. Then, put it into the oven for curing. After curing, allow it to cool down naturally.

[0020] Step 6) Install the Si3N4 ceramic cylinder. Fill the opening position on the sample with the Si3N4 ceramic cylinder with adhesive. Press the upper and lower surfaces of the sample with a flat plate, attach a release cloth, and put it into the oven for curing. After curing, let it cool naturally. After the sample is taken out, clean the excess adhesive on the sample surface to obtain a lightweight, high-compression-resistant, heat-insulating thermal protection structure.

[0021] Furthermore, in step 2), the mass ratio of SiO2 aerogel powder to SiC powder is 100:20.

[0022] Further, step 3) specifically includes: preparing carbon fiber prepreg using carbon fiber and resin as raw materials; after the prepreg is prepared, it should be coated, wound, and stored; cutting the material according to the dimensions in the cutting drawing and laying it on the mold surface; after the layering is completed, laying peeling cloth, release film, breathable felt, and high-temperature vacuum bag film on the material sheet, sealing and pressing it with a vacuum bag, and then curing it in a hot autoclave; curing regime: 100℃ for 3 hours, 185℃ for 1 hour, 250℃ for 2 hours, with a heating rate of 1℃ / min; when the temperature reaches 100℃, pressurization begins at a pressure increase rate of 0.02 MPa / min, and the final curing pressure is 0.8 MPa; after the heat preservation is completed, cooling is carried out at a cooling rate of 1.5℃ / min; after the curing is completed, the skin base plate is demolded and cut into the design model size as required, and the hole is opened according to the drawing requirements.

[0023] Furthermore, the curing regime for steps 5) and 6) is: heat preservation at 80℃ for 6 hours.

[0024] The thermal protection structure includes:

[0025] Feature 1: Aerogel insulation board with bosses around the perimeter and center, and a hole in the center of the bosses to facilitate the later assembly of ceramic cylinders;

[0026] Feature 2, mixed powder: SiO2 aerogel powder and SiC powder;

[0027] Feature 3: Carbon fiber reinforced resin-based composite board;

[0028] Feature 4: Si3N4 ceramic cylinder;

[0029] The composite aerogel insulation board has a hollow design with protrusions at the four corners and the center. The protrusions have openings in the center, and Si3N4 ceramic cylinders are connected to the openings. The insulation board is filled with aerogel powder, and the bottom is sealed with a carbon fiber reinforced resin-based composite board. All structures are connected with inorganic high-temperature sealing adhesive.

[0030] The aerogel insulation panel in this structure uses a composite aerogel, a new generation of fire-resistant and heat-insulating material with ultra-low thermal conductivity, capable of operating at 900℃ for extended periods. It not only possesses superior ultra-low thermal conductivity compared to traditional aerogel materials but also boasts multiple advantages such as lightweight, high strength, processability, and waterproofing. Furthermore, the composite aerogel insulation panel in this structure features a hollow design, further reducing the overall mass of the sample; the aerogel powder filling the insulation panel is only 3 mg / cm³. 3Only three times heavier than air, this aerogel powder can reduce the density of the sample and achieve a lightweight effect. At the same time, the aerogel powder has a lower thermal conductivity than air, making it an ideal thermal insulation material. The Si3N4 ceramic cylinders used for sample connection have advantages such as high hardness, high strength of 2500MPa, high temperature resistance of 1200℃, good heat dissipation, good thermal shock resistance, and low density. The combination and assembly of the above materials for the thermal protection structure system can effectively solve the problems of large mass and low load-bearing capacity of traditional thermal protection structures.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] First, compared with the existing metal-based cover plate type thermal protection structure, the external frame of the present invention adopts a composite aerogel insulation board with hollowed-out interior, which better reduces the overall structural weight.

[0033] Second, compared with existing rigid ceramic heat insulation tiles, the present invention reduces the mass of the structural sample by filling it with aerogel powder that is lighter and has a lower thermal conductivity, while achieving the technical indicator of low thermal conductivity of the overall structural sample.

[0034] Third, compared with filling the interior with pure aerogel powder, the present invention achieves better shielding of infrared radiation by doping with a certain amount of light-blocking agent (SiC powder), which is the key to the sample having better temperature resistance and thermal insulation performance.

[0035] Fourth, compared with existing heat-protected sandwich structures that use high-temperature resistant fiber threads for stitching, this invention uses Si3N4 ceramic pillars and inorganic high-temperature sealant for connection, ensuring sample consistency while better blocking heat conduction. Simultaneously, the Si3N4 ceramic pillars have a compressive strength of 2500 MPa, enabling the overall structural sample to withstand higher compressive strength without damage. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the sample structure in Example 1.

[0038] Figure 2 This is a schematic diagram of the aerogel insulation plate in step 1) of Example 2.

[0039] Figure 3 This is a schematic diagram of step 5) of Example 2 after filling with the mixed powder.

[0040] Figure 4 This is a schematic diagram of the composite board after bonding in step 5) of Example 2.

[0041] Among them, 100 is an aerogel insulation board, 101 is a boss, 200 is a mixed powder, 300 is a ceramic cylinder, and 400 is a carbon fiber reinforced resin-based composite board. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1

[0044] like Figure 1-4 The lightweight, high-compression-resistant, and heat-insulating thermal protection structure shown includes:

[0045] The aerogel insulation board 100 includes a square box body, with protrusions 101 at the four corners and the center of the box body. Circular holes are opened on the protrusions 101. The aerogel insulation board 100 is made of silica aerogel composite aluminum silicate insulation cotton.

[0046] Mixed powder 200, including SiO2 aerogel powder and SiC powder, is filled in the cavity formed between the aerogel heat insulation plate 100 protrusion 101 and the box body.

[0047] Si3N4 ceramic cylinder 300 is filled into the round hole of boss 101;

[0048] A carbon fiber reinforced resin-based composite board 400 is bonded to an aerogel insulation board 100 to seal the cavity of the aerogel insulation board 100.

[0049] A method for preparing a lightweight, high-compression-resistant, and heat-insulating thermal protection structure includes:

[0050] Step 1) Fabricate the aerogel insulation board 100, mainly composed of silica aerogel composite aluminum silicate insulation cotton. It is processed using a carving machine and wire cutting technology, with a bottom and side thickness of 3mm, forming a square box structure. Bosses 101 are provided at the four corners and center of the box, with a central hole for each boss 101 to facilitate later assembly of the ceramic cylinder 300. Figure 2 As shown.

[0051] Step 2) Prepare mixed powder 200: Prepare SiO2 aerogel powder and SiC powder. The mass ratio of mixed powder 200 is: SiO2 aerogel powder: SiC powder = 100: 20. The powder should be shaken thoroughly to ensure uniform mixing before use.

[0052] Step 3) Carbon fiber reinforced resin matrix composite board 400, using T800 carbon fiber and B2501 type bismaleimide resin as raw materials, T800 / B2501 carbon fiber prepreg is prepared by a two-step method. After the prepreg is prepared, it should be coated, wound up and stored.

[0053] Cut the material according to the dimensions shown in the cutting diagram and lay it on the cleaned mold surface. The material is laid in one layer. After laying the first layer, lay a peeling cloth, release film, breathable felt, and high-temperature vacuum bag film on the material sheet. Vacuum the bag tightly and compact it. Place it in an autoclave for curing and shaping. The curing regime is: 100℃ for 3 hours, 185℃ for 1 hour, and 250℃ for 2 hours, with a heating rate of 1℃ / min. When the temperature reaches 100℃, begin pressurization at a pressure increase rate of 0.02 MPa / min, with a final curing pressure of 0.8 MPa. After the heat treatment, cool the material at a rate of 1.5℃ / min.

[0054] After curing, the skin base plate is demolded and cut into the designed digital model size as required. Holes are then made according to the drawings for later use.

[0055] Step 4) Si3N4 ceramic cylinder 300. The length dimension of the ceramic cylinder is machined using a surface grinder, with the length tolerance controlled within ±0.1mm and the parallelism guaranteed within 0.02mm. The outer diameter is machined using a centerless grinder, with the outer diameter tolerance controlled within ±0.005mm.

[0056] Step 5) The structural components of the thermal protection sample are bonded together using ceramic pillars and sealant. First, sufficient mass of aerogel mixed powder 200 is filled inside the aerogel insulation plate 100. Then, a ring of sealant is applied around the perimeter of the insulation plate. The carbon fiber reinforced resin-based composite plate 400 is then bonded to the top of the insulation plate, and light pressure is applied with a heavy object. The sample is then placed in an oven for curing at 80℃ for 6 hours. After curing, it is allowed to cool naturally. Figure 3-4 As shown.

[0057] Step 6) Remove the sample and fill the opening of the sample with the Si3N4 ceramic pillar containing adhesive. Press the upper and lower surfaces of the sample using a flat plate (apply release cloth to prevent the sample from sticking to the plate and causing damage). Curing in an oven at 80℃ for 6 hours. After curing, allow to cool naturally. After removing the sample, carefully clean any excess adhesive from the surface using 400# sandpaper to ensure a smooth and aesthetically pleasing outer surface.

[0058] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a lightweight, high-compression-strength, heat-insulating thermal protection structure, wherein the lightweight, high-compression-strength, heat-insulating thermal protection structure comprises: The aerogel insulation board (100) includes a square box body, with bosses (101) at the four corners and the center of the box body, and round holes on the bosses (101); A mixed powder (200), including aerogel powder and SiC powder, is filled in the cavity formed between the aerogel heat insulation plate (100) boss (101) and the box body; A ceramic cylinder (300) is filled into the circular hole of the boss (101); A carbon fiber reinforced resin-based composite board (400) is bonded to an aerogel insulation board (100) to seal the cavity of the aerogel insulation board (100); The aerogel insulation board (100) is made of silica aerogel composite aluminum silicate insulation cotton; The aerogel powder is selected from SiO2 aerogel powder; The ceramic cylinder (300) is a Si3N4 ceramic cylinder (300), characterized by the following steps: Step 1) Make an aerogel insulation board (100). The raw material is silica aerogel composite aluminum silicate insulation cotton. It is processed into shape using a carving machine and wire cutting process and then set aside. Step 2) Fill the mixed powder (200), and mix the SiO2 aerogel powder and SiC powder thoroughly for later use; Step 3) Fabricate carbon fiber reinforced resin-based composite board (400). Use carbon fiber and resin as raw materials to prepare carbon fiber prepreg, which is then laid, cured in an autoclave, and cut for later use. Step 4) Fabricate Si3N4 ceramic cylinders (300), process them using a surface grinder, and set them aside for later use; Step 5) Sample assembly: First, fill the aerogel insulation board (100) with a sufficient mass of aerogel mixed powder (200). Then, apply a ring of sealant around the aerogel insulation board (100). Adhere the carbon fiber reinforced resin-based composite board (400) to the aerogel insulation board (100) and lightly press it with a heavy object. Then, put it into the oven for curing. After curing, let it cool down naturally. Step 6) Install the Si3N4 ceramic cylinder (300). Fill the opening position on the sample with the Si3N4 ceramic cylinder with adhesive. Press the upper and lower surfaces of the sample with a flat plate, attach the release cloth, and put it into the oven for curing. After curing, let it cool naturally. After the sample is taken out, clean the excess adhesive on the sample surface to obtain a lightweight, high-compression-resistant, heat-insulating thermal protection structure.

2. The production method according to claim 1, characterized by, In step 2), the mass ratio of SiO2 aerogel powder to SiC powder is 100:

20.

3. The preparation method according to claim 1 or 2, characterized in that, Step 3) specifically includes: preparing carbon fiber prepreg using carbon fiber and resin as raw materials; after the prepreg is prepared, it should be coated, wound, and stored; cutting the material according to the dimensions in the cutting drawing and laying it on the mold surface; after the layering is completed, laying peeling cloth, release film, breathable felt, and high-temperature vacuum bag film on the material sheet, sealing and pressing it with a vacuum bag, and then curing it in a hot autoclave; curing regime: 100℃ for 3 hours, 185℃ for 1 hour, 250℃ for 2 hours, with a heating rate of 1℃ / min; when the temperature reaches 100℃, pressurization begins at a pressure increase rate of 0.02 MPa / min, and the final curing pressure is 0.8 MPa; after the heat preservation is completed, cooling is carried out at a cooling rate of 1.5℃ / min; after the curing is completed, the skin base plate is demolded and cut into the design mold size as required, and the holes are opened according to the drawing requirements.

4. The production method according to claim 1 or 2, characterized by, The curing regime for steps 5) and 6) is: 80℃ for 6 hours.

Images