Frame type multi-cavity structure ceramic matrix composite component and preparation method thereof

Abstract

The invention discloses a frame type multi-cavity structure ceramic matrix composite component and a preparation method thereof, belongs to the technical field of ceramic matrix composite component forming, and solves the problem that the technical difficulty of frame type composite component overall woven preform forming and chemical vapor deposition is high. The method specifically comprises the following steps that a closed frame component is split into two parts, namely a semi-closed frame component and a flat plate component; performing prefabricated body forming on the semi-closed frame component by adopting a split mold; the box-type prefabricated body is assembled and fixed through a combined positioning mold, then the periphery of the prefabricated body is wrapped with a continuous fiber laying layer, and the prefabricated body is fixedly sewn; and preparing an interface layer and a base body on the whole frame component prefabricated body by adopting a chemical vapor deposition process. According to the closed frame type multi-cavity structure, the closed frame type multi-cavity structure is divided into the semi-closed frame component and the flat plate component, preparation of the two components is conducted, the two components are connected through the connecting piece, and preparation of the totally-closed frame component can be achieved.

Description

Technical Field

[0001] This invention relates to the field of ceramic matrix composite component molding technology, and in particular to a frame-type multi-cavity ceramic matrix composite component and its preparation method. Background Technology

[0002] In the field of satellite telescopes, frame-type components are commonly used as load-bearing structures. Satellite telescopes impose stringent requirements on the supporting structure of these frame-type components, demanding high rigidity, lightweight design, and sub-micron level optical positioning accuracy. Traditional frame-type components are fabricated using metal structures or metal-composite hybrid structures. Metal structures suffer from poor thermal performance; metal-composite hybrid structures have problems such as numerous parts, large cumulative assembly errors, and thermal expansion mismatch. Composite material frame components offer high strength, light weight, and excellent performance. Furthermore, functional requirements necessitate fully enclosed structures, but existing composite components cannot achieve fully enclosed fabrication due to limitations in mold release during the manufacturing process.

[0003] Furthermore, existing composite frame components are manufactured using a prefabricated, integrally woven process, which avoids the complexity of modular structures and simplifies assembly. However, the internal deposition process of these frame components requires structural considerations to ensure gas flow and improve deposition efficiency. Using modular composite prefabricated components, which involve assembling multiple prefabricated parts to achieve complex configurations, results in cumbersome assembly procedures, increased weight and cost. More importantly, because the components are not integrally deposited through vapor deposition, the continuity of optical alignment surfaces is interrupted, affecting overall stiffness and accuracy.

[0004] This patent proposes a method for preparing a closed-frame multi-cavity ceramic matrix composite component. By preparing the closed-frame composite component and the flat plate component separately, the two components are combined to achieve the preparation of a fully closed-frame composite component. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a frame-type multi-cavity ceramic matrix composite component and its preparation method, solving the problems of difficult preparation of fully enclosed frame-type composite components and the high technical difficulty of integral woven preform molding and chemical vapor deposition.

[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 frame-type multi-cavity ceramic matrix composite component includes the following steps: Step S1: Disassembly of the closed frame multi-cavity component structure; Step S2: Design the structure of the prefabricated composite frame components; Step S3: Use a split mold to weave the prefabricated body, and use the split mold to lay up and sew the internal cavity box-shaped prefabricated body; Step S4: Assemble and fix the sewn box-shaped prefabricated body using a combination positioning mold, and then cover the assembled prefabricated body with continuous fiber lay-up. Step S5: Fix and sew together the assembled box-shaped prefabricated parts and the outer continuous fiber prefabricated parts. Step S6: Prepare the interface layer of the precast frame components. Step S7: Perform high-temperature treatment on the frame components to improve the toughness of the precast fiber; Step S8: The prefabricated frame components are densified and then machined to obtain composite frame components. Step S9: Assemble the composite components using connectors; Step S10: Determine the quality of the composite frame components.

[0007] In this invention, the closed-frame multi-cavity structure consists of two parts: a semi-closed frame component and a flat plate component. These two components are fabricated separately and connected by connectors to achieve the fabrication of a fully enclosed frame component. The semi-closed frame component is fabricated by first sewing together a box-shaped prefabricated body to obtain the overall frame component prefabricated body. The flat plate component is prefabricated using a flat plate mold. An interface layer and a substrate are deposited between the two prefabricated bodies. This design combines integral fabric prefabrication technology with chemical vapor deposition technology to achieve a lightweight structure, simple assembly, continuous fibers, and dense and uniform deposition, meeting the high-precision optical load-bearing requirements of satellites.

[0008] Furthermore, in step S1, the fully enclosed frame composite component is divided into two parts: a semi-enclosed frame component and a flat plate component. In addition, a separate boss structure is set in the installation interface area.

[0009] Further, step S2 includes: Step S201: Set the thickness of the prefabricated frame components. Based on the strength and stiffness requirements of the component products, use finite element analysis combined with optical constraint requirements on the reference plane to optimize the structural thickness distribution and form a composite frame prefabricated body that meets mechanical and positioning accuracy requirements, with a wall thickness range of 3mm-10mm. Step S202: Several independent cavities are reserved inside the composite frame prefabrication. Each cavity is a separate box-shaped prefabrication. The size of each cavity meets the installation requirements of the optical components. Step S203: Based on the wall thickness requirements of the precast body and the combination of box-shaped precast bodies, the entire outer surface is woven with continuous fibers.

[0010] Furthermore, in step S3, the prefabricated frame components are laid with 3K twill fabric in the X and Y directions, and 3K carbon fiber single strand bidirectional stitching in the Z direction.

[0011] Furthermore, in step S6, a pyrolytic carbon interface layer is generated on the surface of the preform fiber using CVI vapor deposition technology to protect the fiber.

[0012] Further, step S8 includes: Step S801: Prepare SiC matrix for frame component preform using CVI vapor deposition process until the preform is densified to the specified density requirement; Step S802: After the precast body is densified to meet the density requirements, the composite components are processed. The external dimensions of the components are processed by machining, but the internal cavities are not processed. Step S803: The composite component is locally processed through grinding to meet the dimensional and geometric tolerance requirements of the component product.

[0013] Further, step S10 includes: Step S1001: Use a coordinate measuring machine to check the geometric tolerance of the positioning surface of the composite frame component. The surface form and position tolerance is required to be ≤ ±0.1, and the structural area accuracy requirement is ≤ ±0.01. Step S1002: Measure the density of the composite frame components using the drainage method and the volumetric method; Step S1003: Perform unconstrained modal vibration tests on the composite frame components. The deviation between the first natural frequency and the finite element simulation value is ≤5%.

[0014] In a second aspect, the present invention provides a frame-type multi-cavity ceramic matrix composite component; the component is prepared using the preparation method of the frame-type multi-cavity ceramic matrix composite component provided in the first aspect.

[0015] The beneficial effects of this invention are: The present invention provides a method for preparing a closed-frame multi-cavity ceramic matrix composite component, which solves the problem that traditional closed composite frame components cannot be demolded. It adopts the method of preparing split components to realize the preparation of a fully closed-frame multi-cavity composite structure.

[0016] In the preparation method of the frame-type multi-cavity ceramic matrix composite component provided by the present invention, the composite base component is an integrally molded component. Compared with the conventional composite component assembled separately, it has fewer parts, a simpler assembly process, and a shorter preparation cycle.

[0017] The composite base has a separate boss at the installation interface. The installation interface accuracy requirements can be ensured by machining the boss, avoiding large-area machining, ensuring the fiber continuity of the overall component, and improving the structural rigidity.

[0018] The prefabricated composite component features through-channels to ensure gas flow and improve densification efficiency during the vapor deposition process. Furthermore, the composite component has a semi-enclosed internal structure, allowing for demolding via these channels.

[0019] The composite base component is large in size and consists of multiple semi-enclosed cavities. The density of the component measured by conventional drainage and volumetric methods has errors. In order to ensure the quality of component fabrication, free modal testing is performed on the component and compared with the calculated structure, which can effectively detect the quality of component fabrication. Attached Figure Description

[0020] Figure 1 A flowchart illustrating a method for preparing a closed-frame, multi-cavity ceramic matrix composite component; Figure 2 A schematic diagram of the overall structure of a closed-frame multi-cavity ceramic matrix composite component; Figure 3 A structural cross-sectional view of a closed-frame multi-cavity ceramic matrix composite component; Figure 4 A schematic diagram showing the disassembled structure of a closed-frame multi-cavity ceramic matrix composite component; Figure 5 A schematic diagram of a semi-enclosed frame-type multi-cavity ceramic matrix composite component; Figure 6 This is a structural schematic diagram of a flat plate component; Figure 7 A structural diagram of a prefabricated ceramic matrix composite component with a semi-closed frame-type multi-cavity structure. Figure 8 A schematic diagram of a prefabricated ceramic matrix composite component with a semi-closed frame-type multi-cavity structure. Figure 9 This is a contour plot of the results from the free modal finite element method calculation.

[0021] Figure label: 1. Semi-enclosed frame components; 2. Flat plate components; 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.

[0022] like Figure 1As shown, this embodiment provides a method for preparing a frame-type multi-cavity ceramic matrix composite component. By combining an integral fabric preform with chemical vapor deposition, a lightweight structure with simple assembly, continuous fibers, and dense, uniform deposition is achieved, meeting the high-precision optical load-bearing requirements of satellites. The method includes the following steps: like Figure 2-8 As shown, the design of the prefabricated composite frame component structure includes: Step S1: The enclosed frame multi-cavity component structure is disassembled. The fully enclosed frame composite component is divided into two parts: a semi-enclosed frame component 1 and a flat plate component 2. In addition, a separate boss structure is set in the installation interface area.

[0023] Step S2: Design the structure of the prefabricated composite frame components; specifically including: Step S201: Set the thickness of the prefabricated frame components. Based on the strength and stiffness requirements of the component products, use finite element analysis combined with optical constraint requirements on the reference plane to optimize the structural thickness distribution and form a composite frame prefabricated body that meets mechanical and positioning accuracy requirements, with a wall thickness range of 3mm-10mm. Step S202: Several independent cavities are reserved inside the composite frame prefabrication. Each cavity is a separate box-shaped prefabrication. The size of each cavity meets the installation requirements of the optical components. Step S203: Based on the wall thickness requirements of the preform and the combination of the box-shaped preforms, continuous fibers are wound and woven on the overall outer surface; the fibers are kept continuous at the cavity separation of the box-shaped parts to ensure the overall fiber continuity, and the fiber volume fraction is controlled at 50-60% to prepare a multi-cavity fiber preform; Step S204: Based on the dimensional accuracy requirements of the component product, for areas requiring high-precision dimensions, design process bosses for subsequent separate processing to avoid fiber breakage caused by large-area processing.

[0024] Step S3: The prefabricated body is woven using a split mold. The internal cavity box-shaped prefabricated body is then laid up and sewn using the split mold. Toray T300-3K twill fabric (area density 200±5g / m²) is used in the X and Y directions of the frame component prefabricated body. 3 The layers are laid up, and Toray T300-3K carbon fiber single strand bidirectional stitching is used in the Z direction, with a stitch spacing of 5*5mm.

[0025] Step S4: Assemble and fix the sewn box-shaped prefabricated body using a combination positioning mold, and then cover the assembled prefabricated body with continuous fiber layup to meet the prefabricated body layup thickness requirements and ensure the fiber continuity of the prefabricated body.

[0026] Step S5: Fix and sew together the assembled box-shaped prefabricated parts and the external continuous fiber prefabricated parts.

[0027] Step S6: Prepare an interface layer on the precast frame component; use CVI vapor deposition to generate a pyrolytic carbon interface layer on the fiber surface of the precast component to protect the fiber.

[0028] Step S7: Perform high-temperature treatment on the frame components to improve the toughness of the precast fiber.

[0029] Step S8: The precast frame components undergo a densification process, followed by machining to obtain composite frame components; specifically including: Step S801: Prepare SiC matrix for frame component preform using CVI vapor deposition process until the preform is densified to the specified density requirement; Step S802: After the precast body is densified to meet the density requirements, the composite components are processed. The external dimensions of the components are processed by machining, but the internal cavities are not processed. Step S803: The composite component is locally processed through grinding to meet the dimensional and geometric tolerance requirements of the component product.

[0030] Step S9: Assemble the composite components using connectors.

[0031] Step S10: Determine the quality of the composite frame components; specifically including: Step S1001: Use a coordinate measuring machine to check the geometric tolerance of the positioning surface of the composite frame component. The surface form and position tolerance is required to be ≤ ±0.1, and the structural area accuracy requirement is ≤ ±0.01. Step S1002: The density of the composite frame components is measured using the drainage method and the volumetric method to ensure that the composite frame components meet the density and porosity requirements; Step S1003: Perform unconstrained modal vibration tests on the component; the deviation between the first natural frequency and the finite element simulation value is ≤5%. Figure 9 As shown.

[0032] Example 2 like Figure 2-8 As shown, this embodiment provides a frame-type multi-cavity ceramic matrix composite component, which is prepared using a preparation method for a frame-type multi-cavity ceramic matrix composite component provided in this embodiment.

[0033] 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 that the scope of protection of the invention is not limited 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 in this invention 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 for preparing a frame-type multi-cavity ceramic matrix composite component, characterized in that, Includes the following steps: Step S1: Disassembly of the closed frame multi-cavity component structure; Step S2: Design the structure of the prefabricated composite frame components; Step S3: Use a split mold to weave the prefabricated body, and use the split mold to lay up and sew the internal cavity box-shaped prefabricated body; Step S4: Assemble and fix the sewn box-shaped prefabricated body using a combination positioning mold, and then cover the assembled prefabricated body with continuous fiber lay-up. Step S5: Fix and sew together the assembled box-shaped prefabricated parts and the outer continuous fiber prefabricated parts. Step S6: Prepare the interface layer of the precast frame components. Step S7: Perform high-temperature treatment on the frame components to improve the toughness of the precast fiber; Step S8: The prefabricated frame components are densified and then machined to obtain composite frame components. Step S9: Assemble the composite components using connectors; Step S10: Determine the quality of the composite frame components.

2. The method for preparing the frame-type multi-cavity ceramic matrix composite component according to claim 1, characterized in that: In step S1, the fully enclosed frame composite component is divided into two parts: a semi-enclosed frame component (1) and a flat plate component (2). In addition, a separate boss structure is set in the installation interface area.

3. The method for preparing a frame-type multi-cavity ceramic matrix composite component according to claim 2, characterized in that, Step S2 includes: Step S201: Set the thickness of the prefabricated frame components. Based on the strength and stiffness requirements of the component products, use finite element analysis combined with optical constraint requirements on the reference plane to optimize the structural thickness distribution and form a composite frame prefabricated body that meets mechanical and positioning accuracy requirements, with a wall thickness range of 3mm-10mm. Step S202: Several independent cavities are reserved inside the composite frame prefabrication. Each cavity is a separate box-shaped prefabrication. The size of each cavity meets the installation requirements of the optical components. Step S203: Based on the wall thickness requirements of the precast body and the combination of box-shaped precast bodies, the entire outer surface is woven with continuous fibers.

4. The method for preparing the frame-type multi-cavity ceramic matrix composite component according to claim 3, characterized in that: In step S3, the precast frame components are laid with 3K twill fabric in the X and Y directions, and 3K carbon fiber single strand bidirectional stitching in the Z direction.

5. The method for preparing the frame-type multi-cavity ceramic matrix composite component according to claim 4, characterized in that: In step S6, a pyrolytic carbon interface layer is generated on the surface of the preform fiber using CVI vapor deposition technology to protect the fiber.

6. The method for preparing a frame-type multi-cavity ceramic matrix composite component according to claim 5, characterized in that: Step S8 includes: Step S801: Prepare SiC matrix for frame component preform using CVI vapor deposition process until the preform is densified to the specified density requirement; Step S802: After the precast body is densified to meet the density requirements, the composite components are processed. The external dimensions of the components are processed by machining, but the internal cavities are not processed. Step S803: The composite component is locally processed through grinding to meet the dimensional and geometric tolerance requirements of the component product.

7. The method for preparing a frame-type multi-cavity ceramic matrix composite component according to claim 6, characterized in that, Step S10 includes: Step S1001: Use a coordinate measuring machine to check the geometric tolerance of the positioning surface of the composite frame component. The surface form and position tolerance is required to be ≤ ±0.1, and the structural area accuracy requirement is ≤ ±0.

01. Step S1002: Measure the density of the composite frame components using the drainage method and the volumetric method; Step S1003: Perform unconstrained modal vibration tests on the composite frame components. The deviation between the first natural frequency and the finite element simulation value is ≤5%.

8. A frame-type multi-cavity ceramic matrix composite component, characterized in that: The component is prepared using the method described in any one of claims 1 to 7 for the preparation of a frame-type multi-cavity ceramic matrix composite material component.

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