A load-transmitting, wave-transmitting, and shielding integrated composite cabin body and a preparation method thereof

Abstract

The application discloses a bearing-wave-transparent-shielding integrated composite material cabin and a preparation method thereof, and belongs to the technical field of composite materials. The composite material cabin comprises a bearing structure, a wave-transparent area and a shielding layer; the bearing structure is used as a main part of the cabin and is selected from carbon fiber reinforced resin-based composite materials; the wave-transparent area is located on a wave-transparent window of the cabin and is selected from quartz fiber reinforced resin-based composite materials; the shielding layer is laid on the outer surface of the bearing structure and is selected from metal materials; and the bearing structure, the wave-transparent area and the shielding layer are integrally co-cured and formed. The composite material cabin has high bearing capacity, high wave-transparent performance and high shielding performance.

Description

Technical Field

[0001] This invention relates to a high-temperature resistant, load-bearing, wave-transmitting, and shielding integrated composite material cabin and its preparation method, belonging to the field of composite material technology. Background Technology

[0002] Currently, lightweight cabin design is one of the key research areas both domestically and internationally. Resin-based composite materials are characterized by their lightweight, high strength, and high design flexibility. Using resin-based composite materials to replace traditional metal materials in cabin fabrication can effectively reduce weight, improve fuel efficiency and load capacity, and also reduce production costs and shorten the production cycle.

[0003] Traditional composite material cabins mostly use epoxy resin composite materials. However, with the development of high speed, higher requirements have been put forward for the temperature resistance of composite material cabins. Polyimide, phthalonitrile and other resin systems have the characteristics of high temperature resistance and high load-bearing capacity, and have become the high temperature resistant resin systems with the best comprehensive performance.

[0004] Traditional methods of achieving wave-transmitting functionality in cabins often involve machining windows into a metal cabin and then connecting them to composite material windows using adhesive or riveting. This approach involves complex molding and assembly relationships, and the complex structure of the metal cabin necessitates 3D printing, resulting in low efficiency and high costs. In contrast, the integrated load-bearing, wave-transmitting, and shielding structure is a novel composite material component structure that integrates multiple functions. The load-bearing structure uses carbon fiber reinforced resin matrix composite material, the wave-transmitting area uses quartz fiber reinforced resin matrix composite material, and the shielding layer uses metal materials. The load-bearing structure, wave-transmitting area, and shielding layer are fabricated using a monolithic co-curing molding process. This monolithic co-curing molding replaces traditional separate molding methods such as adhesive bonding and riveting, effectively ensuring the overall performance and internal quality of the cabin, improving structural efficiency, and giving the structure excellent load-bearing capacity. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a lightweight integrated composite material cabin for load-bearing, wave-transmitting, and shielding, and its preparation method. The integrated composite material cabin uses carbon fiber reinforced high-temperature resistant resin matrix composite material as the load-bearing structure, quartz fiber reinforced high-temperature resistant resin matrix composite material as the wave-transmitting area, and metal material as the shielding layer. The composite material is prepared by integral co-curing through compression molding or autoclave molding process.

[0006] The technical solution of this invention:

[0007] An integrated composite material cabin for load-bearing, wave-transmitting, and shielding includes a load-bearing structure, a wave-transmitting area, and a shielding layer. The load-bearing structure, as the main body of the cabin, is made of carbon fiber reinforced resin matrix composite material. The wave-transmitting area, located at the wave-transmitting window on the cabin, is made of quartz fiber reinforced resin matrix composite material. The shielding layer, which is laid on the outer surface of the load-bearing structure, is made of metal material. The load-bearing structure, the wave-transmitting area, and the shielding layer are integrally co-cured and molded.

[0008] A method for preparing an integrated composite material cabin that combines load-bearing, wave-transmitting, and shielding components includes the following steps:

[0009] (1) The carbon fiber unidirectional prepreg is laid in the mold to form the load-bearing structure. Metal placeholders are used to occupy the wave-transparent area of ​​the composite material cabin forming mold, and then preforming is performed.

[0010] (2) After the preforming is completed, the shielding layer material is laid on the outside of the load-bearing structure, and carbon cloth prepreg is laid on the outside of the shielding layer. The metal occupant block is then removed.

[0011] (3) Place the quartz fiber prepreg in the wave-transparent area of ​​the mold;

[0012] (4) The carbon fiber unidirectional prepreg, the quartz fiber prepreg and the shielding layer material used for forming the load-bearing structure are co-cured and molded as a whole. After curing, the material is naturally cooled to room temperature and demolded to obtain the load-bearing-transparent-shielding integrated composite material cabin.

[0013] Furthermore, the carbon fiber used in the carbon fiber unidirectional prepreg in step (1) is one or more of grades such as T700, T800, T1000, and M40, selected according to the load-bearing capacity of the cabin design; the resin system used in the carbon fiber unidirectional prepreg includes, but is not limited to, polyimide resin and phthalonitrile resin.

[0014] Further, the carbon fiber unidirectional prepreg in step (1) is either a hot-melt prepreg or a wet prepreg; the hot-melt prepreg does not require solvent pretreatment and can be preformed directly; the wet prepreg generally contains solvent, and in order to avoid the problem of increased porosity caused by solvent evaporation during the curing process, solvent pretreatment is required before preforming. The solvent pretreatment adopts the method of vacuum bag sealing followed by heating and vacuum removal. The heating temperature is 80-200℃, and the removal time is 2-4.5h. Appropriate solvent pretreatment parameters are selected according to the type of solvent.

[0015] Further, the preforming in step (1) involves closing the mold and placing it on a press, preforming at 200-260°C for 2.5-4 hours, and then demolding the outer mold after preforming is completed.

[0016] Furthermore, in step (2), a resin film containing a carrier is laid on the inner side of the shielding layer material. The carrier is short-cut carbon fiber, and the resin film is made of the same resin system as the carbon fiber unidirectional prepreg. The film thickness is 0.25-0.5 mm, which can eliminate the thermal stress difference between the metal material and the composite material.

[0017] Furthermore, the shielding layer material in step (2) is selected from one or more of copper mesh, titanium foil, and nickel-plated carbon cloth, each with a thickness of 0.2 to 0.8 mm.

[0018] Furthermore, the carbon cloth used in the carbon cloth prepreg in step (2) is selected from, but is not limited to, T300-3K and T700-6K, and the resin system used is the same as the resin system used in the carbon fiber unidirectional prepreg.

[0019] Furthermore, in step (3), the quartz fiber prepreg is selected as unidirectional quartz fiber prepreg or quartz fiber cloth prepreg, wherein the SiO2 mass fraction of the quartz fiber needs to reach more than 99.9%; the resin system used is the same as the resin system used in the carbon fiber unidirectional prepreg.

[0020] Furthermore, the overall co-curing molding described in step (4) is performed by molding with a high-temperature press or by a hot autoclave. The curing process is 200~240℃ / 2~4h+240~300℃ / 0.5~2h+280~380℃ / 2~3h, and the pressure point is 220~320℃.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) In order to prevent carbon fiber from intruding into the wave-transmitting area and causing a decrease in wave transmission performance, the present invention uses metal placeholders at the corresponding positions in the wave-transmitting area to prevent contamination. The placeholders are connected with screws to ensure positional accuracy. The metal placeholders are removed after preforming.

[0023] (2) The integrated load-bearing, wave-transmitting, and shielding composite material described in this invention reduces weight by more than 27% compared to traditional metal structure solutions, effectively achieving structural weight reduction;

[0024] (3) The use of carbon fiber / quartz fiber composite material to replace metal structure in this invention can reduce production costs and shorten the production cycle;

[0025] (4) Compared with traditional split molding methods such as gluing and riveting, the integral co-curing molding described in this invention can greatly reduce the assembly process, effectively ensure the overall performance and internal quality of the cabin, improve structural efficiency, and give the structure good load-bearing capacity.

[0026] (5) The composite material cabin of the present invention has the characteristics of high temperature resistance, and the long-term use temperature can reach more than 400°C without an external heat protection layer. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a composite material cabin that integrates load-bearing, wave-transmitting, and shielding functions.

[0028] Figure 2 This is a schematic diagram of the surface of a composite material cabin that integrates load-bearing, wave-transmitting, and shielding functions.

[0029] In the diagram: 1-Bearing structure, 2-Wave-transparent area, 3-Shielding layer. Detailed Implementation

[0030] To make the various technical features, advantages, or effects of the present invention more apparent and understandable, a detailed description is provided below in conjunction with the accompanying drawings.

[0031] Example 1

[0032] A 4mm thick layer of T700-grade carbon fiber / polyimide prepreg was laid on the mold, and a wave-transparent area spacer was installed. The mold was then sealed in a vacuum bag and pretreated with solvent in a 200℃ oven for 3.5 hours. The mold was closed, and pre-molding was carried out at 260℃ for 4 hours. After cooling to room temperature, the mold was opened, and a 0.3mm thick resin film and a 0.4mm thick nickel-plated carbon cloth were laid on the outside of the T700-grade carbon fiber / polyimide prepreg. The wave-transparent area spacer was then removed. A 2mm thick layer of quartz fiber cloth / polyimide prepreg was laid on the area occupied by the spacer. The mold was closed again, and the composite material was prepared using a compression molding process. The curing regime was: 240℃ / 3h + 300℃ / 0.5h + 380℃ / 3h, with a pressure point of 320℃. After curing, the material was allowed to cool naturally to room temperature, and then demolded to obtain an integrated load-bearing, wave-transparent, and shielding composite material cabin.

[0033] Example 2

[0034] A 4mm thick layer of T800 grade carbon fiber / phthalonitrile prepreg was laid on the mold, and the wave-transparent area spacer block was installed. The mold was closed, and pre-molding was carried out at 160℃ for 2 hours and at 200℃ for 2.5 hours. After the temperature dropped to room temperature, the mold was opened, and a layer each of a 0.25mm thick resin film, a 0.25mm thick copper mesh, and a 0.2mm thick plain-weave carbon cloth were laid on the outside of the T800 grade carbon fiber / phthalonitrile prepreg. Then the wave-transparent area spacer block was removed. A 2mm thick layer of quartz fiber cloth / phthalonitrile prepreg was laid on the area occupied by the spacer block. The composite material was prepared using an autoclave process with a vacuum degree of -0.090 MPa and a curing regime of 200℃ / 4h + 240℃ / 2h + 280℃ / 2h. The pressure point was 220℃. After curing, the material was allowed to cool naturally to room temperature, demolded, and then post-treated in a 380℃ oven for 4h to obtain an integrated composite material cabin that combines load-bearing, wave-transmitting, and shielding properties.

[0035] Example 3

[0036] A 4mm thick layer of T700-grade carbon fiber / polyimide prepreg was laid on the mold, and a wave-transparent area spacer was installed. The mold was then sealed in a vacuum bag and pretreated with solvent in an 80℃ oven for 4.5 hours. The mold was closed, and pre-molding was carried out at 240℃ for 3 hours. After cooling to room temperature, the mold was opened, and a 0.5mm thick resin film and a 0.8mm thick nickel-plated carbon cloth were laid on the outside of the T700-grade carbon fiber / polyimide prepreg. The wave-transparent area spacer was then removed. A 2mm thick layer of quartz fiber cloth / polyimide prepreg was laid on the area occupied by the spacer. The mold was closed again, and the composite material was prepared using a compression molding process. The curing regime was: 220℃ / 2h + 280℃ / 1h + 320℃ / 2.5h, with a pressure point of 280℃. After curing, the material was allowed to cool naturally to room temperature, and then demolded to obtain an integrated load-bearing, wave-transparent, and shielding composite material cabin.

[0037] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0038] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Appropriate modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention should be covered within the protection scope of the present invention, which is defined by the claims.

Claims

1. A method for preparing an integrated composite material cabin that combines load-bearing, wave-transmitting, and shielding properties, characterized in that, Includes the following steps: (1) The carbon fiber unidirectional prepreg is laid in the mold at the position for forming the load-bearing structure. Metal placeholders are used to occupy the position in the wave-transparent area of ​​the composite material cabin forming mold, and then preforming is carried out. (2) After the preforming is completed, the shielding layer material is laid on the outside of the load-bearing structure, and carbon cloth prepreg is laid on the outside of the shielding layer. The metal occupant block is then removed. (3) Place the quartz fiber prepreg in the wave-transparent area of ​​the mold; (4) The carbon fiber unidirectional prepreg, the quartz fiber prepreg and the shielding layer material used for forming the load-bearing structure are co-cured and molded as a whole. After curing, the material is naturally cooled to room temperature and demolded to obtain the load-bearing-wave-shielding integrated composite material cabin.

2. The preparation method according to claim 1, characterized in that, The carbon fiber used in the carbon fiber unidirectional prepreg in step (1) is one or more of the following grades: T700, T800, T1000, and M40; the resin system used in the carbon fiber unidirectional prepreg is one of the following: polyimide resin and phthalonitrile resin.

3. The preparation method according to claim 1, characterized in that, The carbon fiber unidirectional prepreg in step (1) is either a hot melt prepreg or a wet prepreg. When it is a wet prepreg, a solvent pretreatment is performed before preforming. The solvent pretreatment is performed by vacuum bag sealing followed by heating and vacuum removal. The heating temperature is 80~200℃ and the removal time is 2~4.5h.

4. The preparation method according to claim 1, characterized in that, The preforming process described in step (1) involves closing the mold and placing it on a press, preforming at 200~260℃ for 2.5~4 hours, and then demolding the outer mold after the preforming is completed.

5. The preparation method according to claim 1 or 2, characterized in that, In step (2), a resin film containing a carrier is laid on the inner side of the shielding layer material. The carrier is short-cut carbon fiber, and the resin film is made of the same resin system as the carbon fiber unidirectional prepreg. The film thickness is 0.25~0.5mm.

6. The preparation method according to claim 1, characterized in that, The shielding layer material in step (2) is selected from one or more of copper mesh, titanium foil, and nickel-plated carbon cloth, and the thickness of each is 0.2~0.8mm.

7. The preparation method according to claim 1 or 2, characterized in that, In step (2), the carbon cloth used in the carbon cloth prepreg is either T300-3K or T700-6K, and the resin system used is the same as that used in the carbon fiber unidirectional prepreg.

8. The preparation method according to claim 1 or 2, characterized in that, In step (3), the quartz fiber prepreg is selected as unidirectional quartz fiber prepreg or quartz fiber cloth prepreg, wherein the SiO2 mass fraction of the quartz fiber reaches more than 99.9%; the resin system used is the same as the resin system used in the carbon fiber unidirectional prepreg.

9. The preparation method according to claim 1, characterized in that, The overall co-curing molding described in step (4) is performed by molding with a high-temperature press or by a hot autoclave. The curing process is 200~240℃ / 2~4h + 240~300℃ / 0.5~2h + 280~380℃ / 2~3h, and the pressure point is 220~320℃.

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