Anti-deformation tool for large-size three-way yarn winding prefabricated body and using method

Abstract

The invention discloses an anti-deformation tool for a large-size three-way yarn winding prefabricated body and a using method. And a gas medium transmission hole is reserved in the whole body of the tool. When the tool is used, the soft three-way yarn winding prefabricated body subjected to high-temperature treatment is vertically arranged in the barrel tool with the cover, leftover materials of the same material are filled between the prefabricated body and the tool, and the prefabricated body is prevented from moving in the tool; and placing the tool filled with the prefabricated body on a furnace platform of a chemical vapor deposition furnace, closing the furnace, and performing deposition treatment according to preset process parameters. The problems that other preforms placed on the preforms are extruded at different positions, deformation of the preforms is caused, finally, fibers in the preforms deviate from the original positions in the deformation process, the mechanical property of the C / C composite material prepared based on the preforms is further lost, and the product quality is affected are solved. According to the invention, the gas medium can uniformly and smoothly circulate around the green body in the deposition process, so that the high-quality deposition effect is realized.

Description

Technical Field

[0001] This invention patent belongs to the technical field of carbon / carbon composite material preparation equipment, specifically relating to an anti-deformation tooling for large-size three-dimensional yarn-wound preforms and its usage method. Background Technology

[0002] C / C composites are widely used in aerospace, high-end manufacturing, and other fields due to their low density, high strength, high modulus, good fatigue resistance, and excellent thermal shock resistance. In their preparation, the preform must first be placed in a high-temperature furnace to remove the slurry, impurities, and stress introduced onto the fiber surface during molding, thus adjusting the microstructure of the carbon fiber surface and improving interfacial bonding. This high-temperature treatment results in a softer preform. Because the preform itself has a loose structure and low strength, it is prone to deformation during subsequent chemical vapor deposition processes, especially large-sized triaxially wound preforms, under the influence of high temperature and gas erosion. This deformation of the fibers within the preform leads to a significant loss of the axial and radial mechanical properties of the C / C composite material prepared from it, severely impacting product quality and performance.

[0003] Currently, in similar preform processing, commonly used anti-deformation tooling mainly consists of simple fixing frames or support structures, such as using metal frames to provide external support for the preform. However, this anti-deformation method has very limited support effect on large-sized three-dimensional yarn-wound preforms, making it difficult to restrict their deformation in all directions. Furthermore, the metal material may react with the preform blank during high-temperature chemical vapor deposition, affecting the performance of C / C composite materials prepared based on the densification of the preform. Another anti-deformation measure is to use graphite plates for simple enclosure support, but this method cannot effectively solve the problem of gas medium circulation around the preform, resulting in uneven chemical vapor deposition and affecting the overall performance consistency of the C / C composite material.

[0004] The disadvantages of existing technology are: Poor deformation resistance: It cannot fully and effectively limit the deformation of large-size three-dimensional yarn-wound preforms in the deposition process, making it difficult to guarantee the dimensional accuracy and structural stability of the product.

[0005] Impact on deposition uniformity: The tooling structure is not conducive to the uniform flow of gas medium around the large-size triaxial yarn-wound preform, resulting in uneven deposition of carbon elements inside the large-size triaxial yarn-wound preform during the chemical vapor deposition process, which affects the consistency and stability of the properties of the C / C composite material prepared based on the densification of the preform.

[0006] Compatibility issues: During the high-temperature chemical vapor deposition stage, some tooling materials may react with the preform being resisted from deformation, introducing impurities and reducing the performance of C / C composite materials prepared based on the densification of the preform. Summary of the Invention

[0007] Based on the above-mentioned technical problems, this invention proposes an anti-deformation tooling and method for large-size triaxial wound preforms to solve the deformation problem of large-size triaxial wound preforms in the deposition process. At the same time, it optimizes the gas medium flow path to ensure the uniformity of deposited carbon inside the carbon fibers of the preform, improves the quality and performance of C / C composite materials prepared based on the densification of the preform, and ensures the elemental compatibility of the tooling and C / C composite materials in high-temperature environments, thereby improving the production efficiency and product quality of C / C composite materials.

[0008] To address the aforementioned technical problems, one objective of this invention is to provide an anti-deformation fixture for large-size three-dimensional yarn-wound preforms. This fixture consists of a cylindrical body and a cover capable of accommodating the large-size three-dimensional yarn-wound preform, wherein the cover and the cylindrical body are independent of each other, and the entire body has gas medium transmission pores. In use, the relatively soft three-dimensional yarn-wound preform after high-temperature treatment is vertically placed in the covered cylindrical fixture, and scrap material of the same material as the preform to be treated is filled between the preform and the fixture to prevent the preform from moving inside the fixture. Then, the fixture containing the preform is placed on the furnace platform of a chemical vapor deposition furnace. After the furnace is closed, chemical vapor deposition treatment is carried out according to predetermined process parameters.

[0009] Furthermore, the cylinder and cover of the anti-deformation tooling for the large-size three-dimensional yarn-wound preform are both made of graphite.

[0010] Furthermore, the cylinder has a height of Φ300mm~Φ600mm, a diameter of 500mm, a base thickness of 3cm, and a wall thickness of approximately 1cm.

[0011] Furthermore, the anti-deformation tooling cylinder and cover are provided with pores of Φ1~2 mm. These toolings with pores provide support and protection for the large-size three-dimensional yarn-wound preform and facilitate the flow of gas medium.

[0012] Furthermore, the deformation-resistant tooling cylinder that accommodates the large-size three-dimensional yarn-wound preform has a bottom.

[0013] Based on the same concept, this invention also proposes a method for using an anti-deformation tooling for large-size three-dimensional yarn-wound preforms, comprising the following steps: S1 Preparation: Before using the tooling, check whether each part of the tooling is intact. Then, check whether the height and diameter of the tooling meet the requirements for stable placement of the large-sized three-dimensional yarn-wound preform to be processed. S2 Material Placement: Before performing the chemical vapor deposition process, gently place the large-sized three-dimensional yarn-wound preform to be deposited at the bottom of the anti-deformation fixture, and ensure that the bottom surface of the preform is in stable contact with the bottom of the fixture. S3 Handling: After the tooling has been used to support and fix the large-size three-dimensional yarn-wound preform, the tooling containing the preform is slowly placed on the furnace platform of the chemical vapor deposition furnace. After the preform is adjusted again to ensure its stability, the graphite cover of the tooling is put on. The center of the cover should be aligned with the center of the bottom of the preform and the tooling. S4 Tooling Disassembly: After the deposition process is completed, in the reverse order of installation, first remove the tooling cover, then remove the scrap material around the preform, and then two operators work together to remove the large-sized three-way yarn-wound preform that has been deposited. After that, the tooling is recycled for the next use.

[0014] Furthermore, the S2 placement of the prefabricated body specifically involves: adjusting the position of the prefabricated body to ensure that its center basically coincides with the center of the tooling, and stuffing the octagonal corners of the prefabricated body and the gaps in the tooling with scrap material removed from the batch of prefabricated bodies to ensure that the material is subject to a certain lateral constraint and does not shake significantly.

[0015] The above-described technical solutions of this invention have at least one or more of the following technical effects: This invention belongs to a graphite cylinder-graphite barrel lid combined tooling. This tooling utilizes the principle of multi-point support and all-round constraint to simultaneously apply force to the bottom, side, and top surfaces of the large-size three-way wound yarn preform after high-temperature heat treatment. This ensures that the material is uniformly supported and constrained in all directions, effectively counteracting deformation caused by external forces, temperature changes, and other factors, thus improving deformation resistance by 100%. The uniform openings in the lid and throughout the tooling can increase gas permeability by 50%, thereby improving production efficiency and product quality. Attached Figure Description

[0016] Figure 1 Top view of the tooling cylinder containing the large-size three-way yarn-wound prefabricated body; Figure 2 Schematic diagram of anti-deformation tooling cylinder cover; Among them: 1-large-size three-way winding preform, 2-tool cylinder, 3-tool cylinder cover. Detailed Implementation

[0017] Carbon / carbon composites based on the densification of large-size triaxially wound preforms are becoming increasingly important. However, in the composite manufacturing process, especially when handling low-density large-size triaxially wound preforms in the chemical vapor deposition (CVD) stage, deformation and stability issues arise. This invention presents an anti-deformation fixture for large-size triaxially wound preforms. The fixture is a cylindrical, covered design with holes for gas medium transmission. The relatively soft triaxially wound preform blank, after high-temperature treatment, is placed in this fixture, which is then placed on the furnace platform of a CVD furnace. After the furnace is closed, deposition is performed according to predetermined process parameters. This avoids the compression of the triaxially wound preform at different locations by other preforms placed in the furnace with it, which can cause deformation and ultimately lead to the fibers inside the preform deviating from their original positions during deformation. This further results in a loss of mechanical properties in the C / C composite material based on the preform's densification, or cracking during subsequent processing, affecting product quality.

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments obtained. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0019] This invention relates to an anti-deformation fixture for large-size triaxially wound preforms, comprising a cylindrical body (with a bottom) capable of accommodating the large-size triaxially wound preform and a graphite cap, wherein the cap and the cylindrical body are independent of each other. During the chemical vapor deposition process, the large-size triaxially wound preform is placed in this fixture, and after the cap is closed, the fixture and the preform are placed on the furnace platform of the deposition furnace for subsequent processing. This fixture is convenient to use and reusable. The anti-deformation fixture for the large-size triaxially wound preform is made entirely of graphite, with a height of Φ300mm~Φ600mm, a diameter of 500mm, a base thickness of 3cm, and a wall thickness of approximately 1cm. Holes of Φ1~2mm are drilled in its bottom, cap, and walls to facilitate the flow of gaseous media.

[0020] The method of using the aforementioned anti-deformation tooling for large-size three-dimensional yarn-wound preforms: (1) Preparation: Before using the tooling, check whether each part of the tooling is intact. Then, check whether the height and diameter of the tooling meet the requirements for stable placement of the large-size three-way yarn-wound preform to be processed.

[0021] (2) Material Placement: Before chemical vapor deposition, carefully place the large-sized three-dimensional yarn-wound preform to be deposited at the bottom of the anti-deformation fixture, ensuring that the bottom surface of the preform is in stable contact with the bottom of the fixture. Adjust the position of the preform to ensure that the center of the preform is basically coincident with the center of the fixture, and fill the gaps between the octagonal corners of the preform and the fixture with scrap material removed from the preform during machining to ensure that the material is laterally constrained and does not wobble significantly.

[0022] (3) Handling: After the tooling has been used to support and fix the large-size three-dimensional yarn-wound preform, the tooling containing the preform is slowly placed on the furnace platform of the chemical vapor deposition furnace. After the preform is adjusted again to ensure its stability, the graphite cover of the tooling is put on. The center of the cover should coincide with the center of the bottom of the preform and the tooling.

[0023] (4) Tooling disassembly: After the deposition process is completed, in the reverse order of installation, first remove the cover of the tooling, then remove the scrap around the preform, and then two operators work together to remove the large-sized three-dimensional yarn-wound preform that has been deposited. After that, the tooling is recycled for the next use.

[0024] This invention employs a cylindrical structure, which provides uniform radial support force and effectively constrains the circumferential direction of large-sized three-dimensional wound preforms, preventing distortion or deformation of the preforms due to uneven stress during the deposition process. The Φ500mm diameter is suitable for common large-sized three-dimensional wound preforms, and the 1cm wall thickness ensures sufficient strength for the tooling to support the large-sized three-dimensional wound preforms without affecting gas flow or the overall weight of the tooling due to excessive wall thickness.

[0025] This invention features a pore distribution of Φ1~2cm on the barrel and lid of the tooling. This pore distribution provides support and protection for the large-sized three-dimensional wound preform while simultaneously allowing the gaseous medium during the deposition process to smoothly enter the tooling and flow around it. Good convection is formed between the pores and the internal space of the tooling, ensuring that all parts of the large-sized three-dimensional wound preform are fully in contact with the gaseous medium, achieving uniform deposition of pyrolytic carbon within the preform. During deposition, hydrocarbon gas enters the carbon fiber surface of the preform through these pores and decomposes at high temperatures. The resulting carbon elements are deposited on the carbon fiber surface of the large-sized three-dimensional wound preform. Due to the rational pore design, the carbon elements can grow uniformly on the surface of the large-sized three-dimensional wound preform, effectively improving the density uniformity and performance consistency of the C / C composite material based on this preform.

[0026] The tooling of this invention is made of graphite, which has excellent high-temperature resistance and can maintain stable physical and chemical properties in the high-temperature environment of the deposition furnace. It will not chemically react with the preform blank, ensuring the purity of the C / C composite material based on the preform for densification. Graphite also has certain strength and toughness, providing reliable support for large-size triaxial wound preforms. Furthermore, its coefficient of thermal expansion is close to that of low-density C / C composite materials. During temperature changes, the thermal stress between the tooling and the large-size triaxial wound preform is small, further reducing the risk of deformation of the large-size triaxial wound preform due to thermal stress.

[0027] The rationality of the tooling structure in this invention: The diameter, wall thickness, and pore size and distribution of the cylinder directly affect the tooling's support effect on large-sized three-dimensional wound preforms and the gas flow performance, which are key parameters for ensuring deformation resistance and deposition uniformity. The graphite-based anti-deformation tooling of this invention plays a decisive role in stability under high-temperature environments, compatibility with large-sized three-dimensional wound preforms, and support strength. This invention is already in use and has shown good results, effectively preventing deformation of the preform during the transformation to C / C composite materials, and effectively improving production efficiency and product quality.

[0028] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations to the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A deformation-resistant fixture for a large-size three-dimensional yarn-wound preform, characterized in that the fixture consists of a cylinder and a cover capable of accommodating the large-size three-dimensional yarn-wound preform, wherein the cover and the cylinder are independent of each other, and the entire body has gas medium transmission pores. In use, the relatively soft three-dimensional yarn-wound preform after high-temperature treatment is placed vertically in a covered cylindrical fixture, and scrap material of the same material is filled between the preform and the fixture to prevent the preform from moving inside the fixture. Then, the fixture containing the preform is placed on the furnace platform of the chemical vapor deposition furnace. After the furnace is closed, the deposition process is carried out according to the predetermined process parameters.

2. The anti-deformation tooling for large-size three-dimensional yarn-wound preforms according to claim 1, characterized in that: The cylinder and cover of the anti-deformation tooling for the large-size three-dimensional yarn-wound preform are both made of graphite.

3. The anti-deformation tooling for large-size three-dimensional wound yarn preforms according to claim 1, characterized in that: The cylinder has a height of Φ300mm~Φ600mm, a diameter of 500mm, a base thickness of 3cm, and a wall thickness of approximately 1cm.

4. The anti-deformation tooling for large-size three-dimensional yarn-wound preforms according to claim 1, characterized in that: The anti-deformation tooling cylinder and cover are provided with pores of Φ1~2mm. In addition to supporting and protecting the large-sized three-dimensional yarn-wound preform, the tooling with these pores also facilitates the flow of gas medium and the subsequent pyrolysis reaction.

5. The anti-deformation tooling for large-size three-dimensional wound yarn preforms according to claim 1, characterized in that: The cylindrical body with bottom is used to accommodate the large-sized three-dimensional yarn-wound preform.

6. The method of using the anti-deformation tooling for large-size three-dimensional yarn-wound preforms according to any one of claims 1-5, characterized in that, Includes the following steps: S1 Preparation: Before using the tooling, check whether each part of the tooling is intact. Then, check whether the height and diameter of the tooling meet the requirements for stable placement of the large-sized three-dimensional yarn-wound preform to be processed. S2 Material Placement: Before performing the chemical vapor deposition process, gently place the large-sized three-dimensional yarn-wound preform to be deposited at the bottom of the anti-deformation fixture, and ensure that the bottom surface of the preform is in stable contact with the bottom of the fixture. S3 Handling: After the tooling has been used to support and fix the large-size three-dimensional yarn-wound preform, the tooling containing the preform is slowly placed on the furnace platform of the chemical vapor deposition furnace. After the preform is adjusted again to ensure its stability, the graphite cover of the tooling is put on. The center of the cover should be aligned with the center of the bottom of the preform and the tooling. S4 Tooling Disassembly: After the deposition process is completed, in the reverse order of installation, first remove the tooling cover, then remove the scrap material around the preform, and then two operators work together to remove the large-sized three-way yarn-wound preform that has been deposited. After that, the tooling is recycled for the next use.

7. The method of using the anti-deformation tooling for large-size three-dimensional yarn-wound preforms according to claim 6, characterized in that, The S2 material placement specifically involves: adjusting the position of the preform to ensure that the center of the preform basically coincides with the center of the tooling, and stuffing the scrap material removed from the preform from the machine into the gaps between the octagonal corners of the preform and the tooling, so as to ensure that the preform to be chemically vapor-deposited is laterally constrained and does not shake significantly.

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