Preparation method and preparation mold of thin-wall ceramic matrix composite spray pipe

Abstract

The invention discloses a preparation method and a preparation mold for a thin-wall ceramic matrix composite spray pipe, belongs to the technical field of preparation of ceramic matrix composite spray pipes, and solves the problems that the preparation process of an existing three-dimensional needling preform is complicated and is not suitable for a thin-wall spray pipe preform. Comprising the following steps: driving a mold to rotate by utilizing a cloth tape winding machine, and winding a preform on the mold; cracking the preform by adopting a vapor deposition process; depositing a pyrolytic carbon interface layer on the surface of the preform; performing high-temperature treatment on the prefabricated body; impregnating and curing the prefabricated body by adopting a precursor impregnating and cracking process; carrying out SIC matrix deposition on the preform by adopting a chemical vapor deposition process; and machining the inner and outer molded surfaces of the prefabricated body. According to the method, the carbon cloth prepreg tape winding forming mode is adopted, so that the preparation precision of the preform can be improved, fiber faults in the machining process are reduced, and the circumferential strength is enhanced. And meanwhile, the fiber volume content of the preform can be increased by a prepreg tape winding preparation process.

Description

Technical Field

[0001] This invention relates to the field of ceramic matrix composite nozzle preparation technology, and in particular to a method for preparing a thin-walled ceramic matrix composite nozzle and a preparation mold. Background Technology

[0002] Ceramic matrix composites are a new type of strategic material with characteristics such as high temperature resistance, low density, high specific strength, high specific modulus, oxidation resistance, ablation resistance, insensitivity to cracks, and non-catastrophic damage. They have wide applications in aviation, aerospace, satellite spaceflight, nuclear energy, and photovoltaic fields.

[0003] As aircraft speeds and distances continue to increase, the performance requirements for engines are also rising. The exhaust nozzle is a key component in scramjet engines, responsible for converting the thermal energy of the high-temperature, high-pressure combustion gases into kinetic energy. With the diversification of nozzle application conditions, thin-walled nozzles can significantly reduce the mass of the preform while meeting the technical requirements of these applications. Therefore, the molding of ceramic-based thin-walled nozzle preforms and the fabrication of nozzles are urgent technological challenges that need to be addressed.

[0004] Currently, nozzles are typically fabricated using three-dimensional needle-punching technology. The nozzle preform employs a layered structure of longitudinal carbon fiber nonwoven fabric layup + mesh + circumferential fiber winding + mesh. After laying a layer of mesh, the fibers of the mesh are needled into adjacent nonwoven fabric or circumferential winding units. The Z-axis fibers improve the shear strength of the preform. For thin-walled nozzle preforms (preform thickness ≤ 5mm), the traditional three-dimensional needle-punching structure suffers from localized discontinuities in the continuous fiber layers on the inner and outer surfaces during machining due to the thinness of the preform. Furthermore, the limited number of continuous fiber layers due to the thin wall thickness significantly impacts the preform's strength. The fabrication process of three-dimensional needle-punched preforms involves repeated laying and needle-punching, making it complex, labor-intensive, and expensive. Chinese invention patent CN117818087A discloses a method for molding resin-based composite material nozzles using two-dimensional carbon cloth laying. This molding method has cutouts in each layer in the circumferential direction, which greatly reduces the circumferential stress of the preform. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and mold for preparing thin-walled ceramic matrix composite nozzles, which solves the problems that existing three-dimensional needle-punched preform preparation processes are complex and unsuitable for preparing thin-walled nozzle preforms.

[0006] Firstly, in order to achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for preparing a thin-walled ceramic matrix composite nozzle includes the following steps: S1: Assemble the mold and install it on the fabric wrapping machine; S2: Use a fabric wrapping machine to drive the mold to rotate and wrap the preform on the mold; S3: The preform is pyrolyzed using a vapor deposition process; S4: A pyrolytic carbon interface layer is deposited on the surface of the preform using the CVI process; S5: High-temperature treatment of the precast body; S6: The preform is impregnated and cured using a precursor impregnation and pyrolysis process; S7: SiC matrix deposition is performed on the preform using chemical vapor deposition (CVD) process; S8: Machining the inner and outer surfaces of the precast body; S9: The silicon carbide substrate of the preform is densified again using chemical vapor deposition.

[0007] In this scheme, a fabric wrapping machine drives the mold to rotate while carbon fiber prepreg is wound onto the mold to form a preform. The raw material used is 3K carbon fiber prepreg. This carbon fiber prepreg winding method can improve the preparation accuracy of the preform, reduce fiber breakage during machining, and enhance circumferential strength. Simultaneously, the prepreg winding process can increase the fiber volume content of the preform (3DN preform fiber volume fraction: 25-30%, fabric wrapping preform fiber volume fraction: 50%-60%). The preform can be prepared according to shape through CNC programming design, improving preparation accuracy, increasing preparation efficiency, and reducing subsequent processing.

[0008] Furthermore, S1 includes the following steps: S101: Assemble the upper inner mold and the lower inner mold. The upper inner mold and the lower inner mold are connected by double-headed bolts and nuts. S102: Pre-positioning fixture installed inside the lower inner mold; Post-positioning fixture installed at the end of the upper inner mold; S103: Fix the mounting shafts of the front positioning fixture and the rear positioning fixture onto the jaws and ejector pins of the tape winding machine, respectively.

[0009] Furthermore, S2 includes the following steps: S201: The fabric tape winding machine drives the mold to rotate. During the rotation, the carbon fiber phenolic resin prepreg tape is wound circumferentially along the outer surface of the lower inner mold and the upper inner film to form a preform. S202: After the preform is wound, 1 to 3 layers of carbon fiber bundles are wound on the outermost layer of the preform to increase the density of the preform after the carbon fiber phenolic resin prepreg tape is wound. S203: After the outer carbon fiber bundle is wound, remove the preform and mold from the tape winding machine, and remove the front positioning fixture and the rear positioning fixture. S204: 3K carbon fiber bundles are used to sew the wound preform along the Z-direction fiber sewing holes on the mold surface to strengthen the interlayer bonding between the carbon fiber phenolic resin prepreg layers. S205: Place the preform in a vacuum bag and evacuate it. After the vacuum degree of the preform stabilizes at -5 to -30 kPa, pre-cur the preform in an oven or autoclave. The curing temperature is 50 to 160℃ and the time is 1 to 2 hours.

[0010] In this scheme, carbon fiber phenolic resin prepreg tape is first wound around the mold, then a large bundle of carbon fiber filaments is wound around, and finally the carbon fiber is sewn along the Z-direction fiber sewing holes to ensure the connection and density between the fibers.

[0011] Furthermore, S5 includes the following steps: S501: Remove the seam between the precast body and the mold, remove the double-ended bolts and nuts, and remove the upper inner mold and the lower inner mold; S502: High-temperature treatment under an inert atmosphere; heat to 1800-2000℃ and hold for 1-3 hours, then cool naturally to room temperature; S503: Reinstall the upper and lower inner molds inside the precast body, and install the double-ended bolts and nuts.

[0012] In this scheme, the preform undergoes high-temperature treatment, which can increase the graphitization degree of the carbon fiber cloth and enhance its mechanical properties and temperature resistance.

[0013] Furthermore, S6 includes the following steps: S601: Polycarbosilane is used to impregnate the outer surface of the preform after molding under normal pressure. The impregnation time is 1~4h, so that the polycarbosilane can fully penetrate into the pores of the preform. S602: Curing is performed while the mold is in place, at a curing temperature of 80~200℃, and the curing time is 1~3 hours.

[0014] Furthermore, S7 includes the following steps: S701: Remove the upper inner mold and lower inner mold; S702: In a vapor deposition furnace, heat to 1100~1400℃ and hold for 1~2 hours to carry out pyrolysis; after pyrolysis, cool down to 890-1050℃. S703: After the temperature stabilizes, SiC matrix deposition is carried out. During the first deposition, the small end of the preform should face upward. S704: Perform a second deposition, with the small end of the preform facing upwards during the second deposition; repeat deposition until the density of the preform is ≥1.85g / cm³.

[0015] In this scheme, the density of the precast body is approximately 1.4~1.5 g / cm³. 3 At the same time, remove the sewing fibers from the precast body cavity. During the deposition process, change the way the components are placed in the furnace by flipping them over to ensure uniform deposition on all sides.

[0016] Furthermore, S8 includes the following steps: S801: Using a CNC lathe to machine the inner and outer surfaces of the precast body; S802: Apply SiC powder to areas with local appearance defects on the inner and outer surfaces of the preform to improve the surface quality of the preform after finishing.

[0017] Secondly, based on the method for preparing a thin-walled ceramic matrix composite nozzle provided in the first aspect, the present invention provides a mold for preparing a thin-walled ceramic matrix composite nozzle, including an upper inner mold and a lower inner mold; the lower inner mold has a flared structure, and the constricted end of the flared structure has a flange edge turned inward, and the interior of the upper inner mold also has a flange edge turned inward; the upper inner mold and the lower inner mold are connected by double-ended bolts that pass through the flange edge, and nuts are installed at both ends of the double-ended bolts.

[0018] Furthermore, it also includes a front positioning fixture and a rear positioning fixture; the rear positioning fixture is installed at the end of the upper inner mold by screws, and the mounting shaft in the middle of the rear positioning fixture is used to fix it on the chuck of the tape winding machine; the front positioning fixture is supported inside the flared end of the lower inner mold, and the flared end of the lower inner mold has a through hole in the radial direction. The front positioning fixture is fixed inside the lower inner mold by a positioning pin and a fastening bolt through the through hole, and the positioning pin and the fastening bolt are arranged alternately.

[0019] Furthermore, the upper inner mold and the lower inner mold are made of graphite; the surface of the lower inner mold is provided with Z-direction fiber sewing holes of φ3 to 5.

[0020] The beneficial effects of this invention are: This invention provides a method for preparing thin-walled ceramic matrix composite nozzles, specifically a method suitable for forming thin-walled (≤5mm) nozzle preforms. This method employs a prefabrication process involving carbon fiber phenolic resin prepreg winding, large-tow circumferential winding, Z-axis carbon fiber stitching, and pre-curing. Compared to traditional three-dimensional needle-punched preform structures, this method offers advantages such as conformal design and preparation, high fiber content, and high thickness accuracy during production. It solves problems associated with traditional three-dimensional needle-punched preforms, including low thickness accuracy, processing defects, low mechanical properties, and large machining operations. Furthermore, since carbon fiber prepreg winding technology is mature and offers a low-cost, mass-producible composite material preform preparation technology with controllable quality, it can significantly reduce the preparation cost of thin-walled nozzle preforms. The combination of PIP and CVI, with a single finishing process after achieving the required density, reduces the number of deposition furnaces and machining operations, shortening the overall process flow.

[0021] The method for preparing thin-walled ceramic matrix composite nozzles provided by this invention is applicable to the preparation of various thin-walled nozzle products and has a wide range of uses. Attached Figure Description

[0022] Figure 1 This is a flowchart of a method for preparing a thin-walled ceramic matrix composite nozzle according to the present invention; Figure 2 This is a schematic diagram of the structure of a mold for preparing a thin-walled ceramic matrix composite nozzle according to the present invention; Figure 3 This is a schematic cross-sectional view of a mold for preparing a thin-walled ceramic matrix composite nozzle according to the present invention. Figure 4 This is an exploded view of a mold for preparing a thin-walled ceramic matrix composite nozzle according to the present invention; Figure 5 This is a cross-sectional view of the preform of the present invention and a partial enlarged view of regions A and B.

[0023] Figure label: 11. Precast body; 12. Lower inner mold; 13. Upper inner mold; 14. Double-ended bolt; 21. Front positioning fixture; 22. Rear positioning fixture; 23. Screw; 24. Fastening bolt; 25. Positioning pin; Detailed Implementation The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Specific embodiments of the present invention are described below to facilitate understanding by those skilled in the art. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various modifications are obvious as long as they fall within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0024] Example 1 like Figures 2-4 As shown, this embodiment provides a mold for preparing a thin-walled ceramic matrix composite nozzle. This mold can be used to prepare the nozzle preform 11 using carbon cloth prepreg winding molding technology, thereby improving the preparation accuracy of the preform 11; specifically, it includes: Upper inner mold 13, lower inner mold 12, front positioning fixture 21 and rear positioning fixture 22; The lower inner mold 12 has a flared structure, with a flange at the constricted end. The upper inner mold 13 also has a flange inside. The upper inner mold 13 and the lower inner mold 12 are connected by double-ended bolts 14 that pass through the flanges, with nuts installed at both ends of the double-ended bolts 14. This reasonable modular design of the mold allows for effective demolding and mold closing within the precast body.

[0025] The rear positioning fixture 22 is installed at the end of the upper inner mold 13 by screws 23. The mounting shaft in the middle of the rear positioning fixture 22 is used to fix it to the chuck of the tape winding machine. The front positioning fixture 21 is supported inside the flared end of the lower inner mold 12. The flared end of the lower inner mold 12 has a through hole in the radial direction. The front positioning fixture 21 is fixed inside the lower inner mold 12 by positioning pins 25 and fastening bolts 24 that pass through the through hole. The positioning pins 25 and fastening bolts 24 are arranged alternately.

[0026] The upper inner mold 13 and the lower inner mold 12 are made of graphite; the surface of the lower inner mold 12 has Z-direction fiber sewing holes of φ3~5. The front positioning fixture 21 and the rear positioning fixture 22 are made of 45# steel.

[0027] The thickness of the mold body area is 15-20mm.

[0028] Example 2 like Figure 1 As shown, this embodiment, based on the thin-walled ceramic matrix composite nozzle preparation mold provided in Embodiment 1, provides a method for preparing a thin-walled ceramic matrix composite nozzle, including the following steps: S1: Assemble the mold and install it on the tape winding machine; specifically including: S101: Assemble the upper inner mold 13 and the lower inner mold 12. The upper inner mold 13 and the lower inner mold 12 are connected by double-headed bolts 14 and nuts. S102: Install the front positioning fixture 21 inside the lower inner mold 12; install the rear positioning fixture 22 at the end of the upper inner mold 13; S103: Fix the mounting shafts of the front positioning fixture 21 and the rear positioning fixture 22 onto the chuck and ejector pin of the fabric wrapping machine, respectively.

[0029] S2: Using a tape winding machine to drive the mold to rotate, the preform 11 is wound onto the mold; specifically including: S201: The fabric wrapping machine drives the mold to rotate. During rotation, the carbon fiber phenolic resin prepreg tape is wound circumferentially along the outer surfaces of the lower inner mold 12 and the upper inner mold 13 to form a preform 11. The preform 11 can be prepared using a conformal winding design. The carbon fiber prepreg tape uses a satin weave base fabric with a surface area of ​​200±10 g / m², and the width of the prepreg tape is 20–50 mm. Figure 5 As shown, in this embodiment, the wound preform 11 has a flared structure, and the wall thickness of the preform 11 gradually decreases towards the nozzle direction.

[0030] S202: After the preform 11 is wound, 1 to 3 layers of 6K or 12K carbon fiber bundles are wound on the outermost layer of the preform 11. Using large bundles of fibers increases the density of the preform 11 after the prepreg tape is wound and improves the uniformity of the wall thickness.

[0031] S203: After the outer carbon fiber bundle is wound, remove the preform 11 and the mold from the tape winding machine, and remove the front positioning fixture 21 and the rear positioning fixture 22. S204: 3K carbon fiber bundles are used to sew the wound preform 11 along the Z-direction fiber sewing holes on the surface of the mold to strengthen the interlayer bonding between the carbon fiber phenolic resin prepreg layers. S205: Make a vacuum bag, which includes a porous isolation film and a vacuum bag film; put the preform 11 into the vacuum bag and evacuate it. When the vacuum degree of the preform 11 is stable at -5 to -30 kPa, pre-cur the preform 11 in an oven or autoclave. The curing temperature is 50 to 160℃ and the time is 1 to 2 hours.

[0032] S3: The preform 11 is pyrolyzed using a vapor deposition process; the pyrolysis temperature is 800-1100℃ and the time is 3-6 hours.

[0033] S4: A pyrolytic carbon (PyC) interface layer is deposited on the surface of preform 11 using the CVI process, with a required interface layer thickness of 100–350 nm.

[0034] S5: High-temperature treatment of preform 11; specifically including: S501: Remove the seam between the precast body 11 and the mold, remove the double-headed bolt 14 and nut, and remove the upper inner mold 13 and the lower inner mold 12; S502: High-temperature treatment is carried out under an inert atmosphere (argon) protection; after heating to 1800-2000℃, it is held for 1-3 hours and then naturally cooled to room temperature to improve the graphitization degree of carbon fiber cloth and enhance its mechanical properties and temperature resistance. S503: Reinstall the upper inner mold 13 and lower inner mold 12 inside the precast body 11, and install the double-ended bolts 14 and nuts.

[0035] S6: The preform 11 is impregnated and cured using a precursor impregnation and pyrolysis process; specifically including: S601: Polycarbosilane (PCS) without curing agent is used to impregnate the outer surface of the preform 11 under normal pressure by casting. The impregnation time is 1~4h, so that the PCS can fully penetrate into the pores of the preform 11. S602: Curing is performed while the mold is in place, at a curing temperature of 80~200℃, and the curing time is 1~3 hours.

[0036] S7: SiC matrix deposition is performed on preform 11 using chemical vapor deposition (CVD); specifically including: S701: Remove the upper inner mold 13 and the lower inner mold 12; S702: In a vapor deposition furnace, heat to 1100~1400℃ and hold for 1~2 hours to carry out pyrolysis; after pyrolysis, cool down to 890-1050℃. S703: After the temperature stabilizes, SiC matrix deposition is carried out. During the first deposition, the small end of the preform 11 is facing upwards. S704: Perform a second deposition, with the small end of the preform 11 facing downwards during the second deposition; repeat deposition until the density of the preform 11 is ≥1.85 g / cm³.

[0037] During the deposition process, the density of the preform 11 is approximately 1.4~1.5 g / cm³. 3 At the same time, remove the sewing fibers from the inner cavity of the precast body 11. During the deposition process, the placement of the components in the furnace is changed by flipping them over to ensure uniform deposition on all sides.

[0038] S8: Machining the inner and outer surfaces of the preform 11; specifically including: S801: Use a CNC lathe to machine the inner and outer surfaces of the preform 11; S802: Apply SiC powder to areas with local appearance defects on the inner and outer surfaces of the preform 11 to improve the surface quality of the preform 11 after finishing. S9: The silicon carbide matrix of preform 11 is densified again using chemical vapor deposition to ensure that the density of the ceramic matrix composite nozzle drainage method is ≥1.95 g / cm³. 3 .

[0039] Example 3 This embodiment, based on Embodiment 2, provides a method for preparing a thin-walled ceramic matrix composite nozzle, including the following steps: S1: Assemble the mold and install it on the tape winding machine; S2: Using a tape winding machine to drive the mold to rotate, the preform 11 is wound onto the mold; specifically including: S201: The fabric tape winding machine drives the mold to rotate. During the rotation, the carbon fiber phenolic resin prepreg tape is wound circumferentially along the outer surfaces of the lower inner mold 12 and the upper inner mold 13 to form a preform 11. The preform 11 can be prepared by conformal winding design. The carbon fiber prepreg tape uses a satin weave base fabric with a surface area of ​​200±10g / m2 and a width of 30mm. S202: After the preform 11 is wound, one layer of 6K carbon fiber filaments is wound around the outermost layer of the preform 11. S203: After the outer carbon fiber bundle is wound, remove the preform 11 and the mold from the tape winding machine, and remove the front positioning fixture 21 and the rear positioning fixture 22. S204: The preform 11 after winding is stitched together with 3K carbon fiber bundles along the Z-direction fiber sewing holes on the surface of the mold. S205: Make a vacuum bag, which includes a porous isolation film and a vacuum bag film; put the preform 11 into the vacuum bag and evacuate it. After the vacuum degree of the preform 11 stabilizes at -10 to -15 kPa, pre-cur the preform 11 in an oven or autoclave at a curing temperature of 140℃ for 1 hour.

[0040] S3: Preform 11 was pyrolyzed using a vapor deposition process; pyrolysis temperature 1100℃, time 3 hours.

[0041] S4: A pyrolytic carbon (PyC) interface layer is deposited on the surface of preform 11 using the CVI process, with a required interface layer thickness of 100–350 nm.

[0042] S5: High-temperature treatment of preform 11; specifically including: S501: Remove the seam between the precast body 11 and the mold, remove the double-headed bolt 14 and nut, and remove the upper inner mold 13 and the lower inner mold 12; S502: High-temperature treatment is carried out under an inert atmosphere (argon) protection; the temperature is raised to 1800℃ and held for 1 hour, then naturally cooled to room temperature to improve the graphitization degree of carbon fiber cloth and enhance its mechanical properties and temperature resistance. S503: Reinstall the upper inner mold 13 and lower inner mold 12 inside the precast body 11, and install the double-ended bolts 14 and nuts.

[0043] S6: The preform 11 is impregnated and cured using a precursor impregnation and pyrolysis process; specifically including: S601: Polycarbosilane (PCS) without curing agent is used to impregnate the outer surface of the preform 11 under normal pressure by casting for 1.5 hours, so that the PCS can fully penetrate into the pores of the preform 11. S602: Curing is performed while the mold is in place, at a curing temperature of 150℃, and the curing time is 1 hour.

[0044] S7: SiC matrix deposition is performed on preform 11 using chemical vapor deposition (CVD); specifically including: S701: Remove the upper inner mold 13 and the lower inner mold 12; S702: In a vapor deposition furnace, heat to 1100℃ and hold for 1 hour to carry out pyrolysis; after pyrolysis, cool down to 1000℃. S703: After the temperature stabilizes, SiC matrix deposition is carried out. During the first deposition, the small end of the preform 11 is facing upwards. S704: Perform a second deposition, with the small end of the preform 11 facing downwards during the second deposition; repeat deposition until the density of the preform 11 is ≥1.85 g / cm³.

[0045] During the deposition process, the density of the preform 11 is approximately 1.4~1.5 g / cm³. 3 At the same time, remove the sewing fibers from the inner cavity of the precast body 11. During the deposition process, the placement of the components in the furnace is changed by flipping them over to ensure uniform deposition on all sides.

[0046] S8: Machining the inner and outer surfaces of the preform 11; specifically including: S801: Use a CNC lathe to machine the inner and outer surfaces of the preform 11; S802: Apply SiC powder to areas with local appearance defects on the inner and outer surfaces of the preform 11 to improve the surface quality of the preform 11 after finishing. S9: The silicon carbide matrix of preform 11 is densified again using chemical vapor deposition to ensure that the density of the ceramic matrix composite nozzle drainage method is ≥1.95 g / cm³. 3 .

[0047] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention and should be understood as not limiting the scope of protection of the invention to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed herein without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of the invention.

Claims

1. A method of fabricating a thin-walled ceramic matrix composite nozzle, characterized by: The method comprises the following steps: S1: assembling a mold and mounting the mold on a tape winding machine; S2: rotating the mold by using the tape winding machine, and winding a preform (11) on the mold; S3: pyrolyzing the preform (11) by using a vapor deposition process; S4: depositing a pyrolytic carbon interface layer on the preform (11) by using a CVI process; S5: high-temperature treating the preform (11); S6: impregnating and curing the preform (11) by using a precursor impregnation and pyrolysis process; S7: depositing a SiC matrix on the preform (11) by using a chemical vapor deposition process; S8: mechanically processing the inner and outer surfaces of the preform (11); S9: densifying the SiC matrix of the preform (11) by using a chemical vapor deposition process again.

2. The thin-walled ceramic matrix composite nozzle fabrication method of claim 1, wherein: The S1 comprises the following steps: S101: assembling an upper inner mold (13) and a lower inner mold (12), and connecting the upper inner mold (13) and the lower inner mold (12) by using a stud bolt (14) and a nut (15); S102: mounting a front positioning tool (21) in the lower inner mold (12), and mounting a rear positioning tool (22) at the end of the upper inner mold (13); S103: fixing the mounting shafts of the front positioning tool (21) and the rear positioning tool (22) on the clamping jaws and the ejector pins of the tape winding machine, respectively.

3. The method of claim 2, wherein: The S2 comprises the following steps: S201: rotating the mold by using the tape winding machine, and circularly winding carbon fiber phenolic resin prepreg tapes along the outer surfaces of the lower inner mold (12) and the upper inner mold (13) during the rotation to form a preform (11); S202: after the winding of the preform (11) is completed, winding 1-3 layers of carbon fiber tows on the outermost layer of the preform (11) to increase the compactness of the preform (11) after the winding of the carbon fiber phenolic resin prepreg tapes; S203: after the winding of the outer layer of carbon fiber tows is completed, taking the preform (11) and the mold off the tape winding machine, and disassembling the front positioning tool (21) and the rear positioning tool (22); S204: sewing the wound preform (11) by using a Z-direction fiber sewing hole along the surface of the mold to strengthen the interlayer bonding between the layers of the carbon fiber phenolic resin prepreg tapes; S205: placing the preform into a vacuum bag, and performing pre-curing on the preform in an oven or a hot press tank after the vacuum degree of the preform is stabilized at -5 to -30 kPa, and the curing temperature is 50-160 ℃, and the time is 1-2 hours.

4. The method of claim 3, wherein: The S5 comprises the following steps: S501: removing the sewing line between the preform (11) and the mold, disassembling the stud bolt (14) and the nut (15), and removing the upper inner mold (13) and the lower inner mold (12); S502: performing high-temperature treatment under the protection of an inert atmosphere; after being heated to 1800-2000 ℃, maintaining the temperature for 1-3 hours, and naturally cooling to room temperature; S503: re-mounting the upper inner mold (13) and the lower inner mold (12) in the preform (11), and mounting the stud bolt (14) and the nut (15).

5. The method of claim 4, wherein: The S6 comprises the following steps: S601: The outer surface of the closed preform (11) is impregnated with polycarbosilane under normal pressure for 1-4 h to allow polycarbosilane to fully penetrate into the pores of the preform (11); S602: Curing is performed in the state of the mold, and the curing temperature is 80-200°C, and the holding time is 1-3 h.

6. The method of claim 5, wherein: The S7 comprises the following steps: S701: The upper inner mold (13) and the lower inner mold (12) are removed; S702: The temperature is raised to 1100-1400°C in the vapor deposition furnace, and the holding time is 1-2 h to perform pyrolysis; after pyrolysis, the temperature is lowered to 890-1050°C; S703: After the temperature is stabilized, the SIC matrix deposition is performed, and the small end of the preform (11) faces upward during the first furnace deposition; S704: The second furnace deposition is performed, and the small end of the preform (11) faces downward during the second furnace deposition; the deposition is repeated until the density of the preform (11) is greater than or equal to 1.85 g / cm³.

7. The method of claim 6, wherein: The S8 comprises the following steps: S801: The inner and outer surfaces of the preform (11) are machined by a numerical control lathe; S802: The SIC powder is coated on the areas with local appearance defects on the inner and outer surfaces of the preform (11) to improve the surface quality of the machined preform (11).

8. A mold for use in a method of manufacturing a thin-walled ceramic matrix composite nozzle according to any one of claims 1 to 7, characterized in that: The upper inner mold (13) and the lower inner mold (12) are included; the lower inner mold (12) has an expanded structure, and the shrinkage end of the expanded structure has a flange inwardly turned, and the inside of the upper inner mold (13) also has a flange inwardly turned; the upper inner mold (13) and the lower inner mold (12) are connected by a double-headed bolt (14) penetrating the flanges, and nuts are installed at both ends of the double-headed bolt (14).

9. The mold for the fabrication of thin-walled ceramic matrix composite nozzle according to claim 8, characterized in that: The front positioning tool (21) and the rear positioning tool (22) are also included; the rear positioning tool (22) is installed on the end of the upper inner mold (13) by a screw (23), and the mounting shaft in the middle of the rear positioning tool (22) is used to fix the jaw of the tape winding machine; the front positioning tool (21) is supported inside the expanded end of the lower inner mold (12), the expanded end of the lower inner mold (12) is provided with a through hole in the radial direction, and the front positioning tool (21) is fixed inside the lower inner mold (12) by a positioning pin (25) and a fastening bolt (24) penetrating the through hole, and the positioning pin (25) and the fastening bolt (24) are arranged alternately.

10. The mold for the fabrication of thin-walled ceramic matrix composite nozzle according to claim 9, characterized in that: The materials of the upper inner mold (13) and the lower inner mold (12) are graphite; the surface of the lower inner mold (12) is provided with Z-direction fiber sewing holes with a diameter of φ3-5.

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