A near-net forming die and forming method for ceramic matrix composite unidirectional stiffened panels

Abstract

This invention discloses a near-net-shape forming mold and method for unidirectional stiffened wall panels of ceramic matrix composites, relating to the field of ceramic composite component forming technology. The mold includes: a lower wall panel assembly with a through mounting groove along its length; two upper clamping assemblies, positioned opposite each other on the lower wall panel assembly, with an installation gap between them; the mounting groove and the installation gap connecting to form a T-shaped deposition cavity; and a unidirectional stiffened wall panel preform disposed within the deposition cavity. The lower wall panel assembly and the upper clamping assemblies jointly restrict deformation of the unidirectional stiffened wall panel preform during deposition, and deposition gas uniformly permeates from multiple slits into the stiffened transition area of ​​the unidirectional stiffened wall panel preform; this effectively avoids problems such as large deposition deformation and uneven deposition in the stiffened transition area.

Description

Technical Field

[0001] This invention relates to the field of ceramic composite component molding technology, and in particular to a near-net-shape molding die and molding method for unidirectional stiffened wall panels made of ceramic-based composite materials. Background Technology

[0002] Ceramic matrix composites possess unique advantages such as lightweight, high-temperature resistance, and oxidation resistance. However, existing ceramic matrix composite wall panels lack reinforcement structures, requiring numerous mounting holes to be machined on the heated surfaces, leading to complex installation operations. Furthermore, during installation or service, the flat surface of ceramic matrix composite heat-resistant wall panels is insufficient to withstand impacts from foreign objects, making them prone to breakage. Therefore, there is an urgent need for ceramic matrix composite components with reinforced structures.

[0003] For T-shaped stiffened wall panel preforms, a stiffened transition area is formed at the junction of the base plate and the stiffening plate. If the forming tooling cannot position the base plate and the stiffening plate separately, the preform may experience relative displacement or local warping during heating and deposition, causing the formed shape to deviate from the predetermined structure. If the tooling blocks the stiffened transition area or restricts the passage of reactive gases to this area, the conditions for gaseous reactants to enter the pores of the local preform may differ from those in the exposed area, resulting in local deposition differences.

[0004] In view of this, how to provide a device and method that can avoid large deposition deformation and uneven deposition in the reinforced transition area is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide an apparatus and method that can avoid large deposition deformation and uneven deposition in the reinforced transition area, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides a near-net-shape forming mold for a ceramic-based composite unidirectional stiffened wall panel, comprising: The lower wall panel assembly has a through mounting groove along its length. Two upper clamping components are disposed opposite to each other on the lower wall panel assembly, and there is an installation gap between the two upper clamping components. The installation groove is connected to the installation gap to form a T-shaped deposition cavity, and the unidirectional stiffened wall panel preform is disposed in the deposition cavity.

[0007] Furthermore, the upper clamping component is L-shaped, and it has multiple L-shaped sewing holes corresponding to the reinforced transition area of ​​the unidirectional reinforced wall panel prefabricated body. The multiple sewing holes are arranged along the length direction of the lower wall panel component. One end of the sewing hole is connected to the reinforced transition area, and the other end is connected to the outside.

[0008] Furthermore, the upper clamping assembly has a first through hole extending through the upper and lower surfaces, and the lower wall panel assembly has a second through hole corresponding to the first through hole. A first fastening bolt is provided in the first and second through holes, and the upper clamping assembly and the lower wall panel assembly are clamped by the first fastening bolt.

[0009] Furthermore, the bottom of the upper clamping assembly is provided with a positioning boss, and the lower wall panel assembly is provided with a positioning groove corresponding to the positioning boss, and the positioning boss and the positioning groove engage.

[0010] Furthermore, the upper clamping assembly has a second through hole extending through its inner and outer surfaces, and a second fastening bolt is disposed in the second through hole of the two upper clamping assemblies, thereby clamping the two upper clamping assemblies together.

[0011] Furthermore, a washer is provided on the second fastening bolt, and the washer is correspondingly disposed in the installation gap between the two upper clamping components.

[0012] This invention also provides a near-net-shape forming method for unidirectional stiffened wall panels made of ceramic matrix composites, using a near-net-shape forming mold for unidirectional stiffened wall panels made of ceramic matrix composites, including the following steps: S1: Place the precast unidirectional stiffened wall panel into the installation slot and assemble the clamping component on the lower wall panel assembly; S2: The lower wall panel assembly, the upper clamping assembly, and the unidirectional stiffened wall panel preform are placed together in the deposition furnace. Chemical vapor deposition is performed on the surface of the unidirectional stiffened wall panel preform. During the deposition process, the lower wall panel assembly and the upper clamping assembly jointly restrict the deformation of the unidirectional stiffened wall panel preform. The deposition gas permeates evenly from multiple slit holes into the stiffened transition area of ​​the unidirectional stiffened wall panel preform.

[0013] Furthermore, the unidirectional stiffened wall panel preform is prepared by the following steps: sewing two-dimensional silicon carbide fiber cloth, rolling it into a T-shape, and forming a unidirectional stiffened wall panel preform by longitudinal stitching and cutting.

[0014] Furthermore, carbon cloth is laid in the installation groove. After the unidirectional reinforced wall panel prefabricated body is placed in the installation groove, the carbon cloth wraps the bottom surface and left and right sides of the unidirectional reinforced wall panel prefabricated body.

[0015] Furthermore, during the deposition process, deposition was first carried out at 600℃ until a deposition interface of 500 nm was formed in the unidirectional stiffened wall panel preform. Then, deposition was carried out at 800℃-1000℃ until the density of the unidirectional stiffened wall panel preform reached 1.3~1.5 g / cm³. 3 Remove the upper clamping assembly to obtain a unidirectional stiffened wall panel.

[0016] The present invention discloses the following technical effects: This invention utilizes the mounting groove of the lower wall panel assembly to support and position the precast base plate. Two upper clamping assemblies limit the position from both sides of the stiffening plate, and the assembly position of the mold is maintained by positioning bosses, positioning grooves, and fastening bolts to reduce the relative displacement between the base plate and the stiffening plate during heating and deposition. The upper clamping assembly has multiple slit holes distributed along the length of the wall panel. These slit holes connect the external atmosphere and the stiffening transition area, ensuring that the area still has a pathway for reactive gas to reach the pores of the precast body when clamped by the tooling. This reduces the impact of partial obstruction by the tooling on gas transmission, thereby improving the deposition consistency in the stiffening transition area. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a side view of the present invention; Among them, 1. Lower wall panel assembly; 101. Mounting groove; 102. Positioning groove; 2. Upper clamping assembly; 201. Sewing hole; 202. Positioning boss; 3. First fastening bolt; 4. Second fastening bolt; 5. Washer. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Those skilled in the art will understand that the term "comprising" as used in this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements present. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a near-net-shape forming mold for a ceramic-based composite unidirectional stiffened wall panel, comprising: The lower wall panel assembly 1 has a through mounting groove 101 along its length; Two upper clamping components 2 are disposed opposite to each other on the lower wall panel component 1. There is an installation gap between the two upper clamping components 2. The installation groove 101 is connected to the installation gap and forms a T-shaped deposition cavity. The unidirectional stiffened wall panel prefabricated body is disposed in the deposition cavity.

[0023] In this embodiment, the upper clamping component 2 is L-shaped, and a plurality of L-shaped sewing holes 201 are provided in the reinforcing transition area of ​​the unidirectional reinforced wall panel preform. The plurality of sewing holes 201 are arranged along the length direction of the lower wall panel component 1. One end of the sewing hole 201 is connected to the reinforced transition area, and the other end is connected to the outside.

[0024] In this embodiment, the upper clamping component 2 has a first through hole extending through the upper and lower surfaces, and the lower wall panel component 1 has a second through hole corresponding to the first through hole. A first fastening bolt 3 is provided in the first through hole and the second through hole, and the upper clamping component 2 and the lower wall panel component 1 are clamped by the first fastening bolt 3.

[0025] In this embodiment, a positioning boss 202 is provided at the bottom of the upper clamping component 2, and a positioning groove 102 is provided on the lower wall panel component 1 corresponding to the positioning boss 202. The positioning boss 202 and the positioning groove 102 engage.

[0026] In this embodiment, the upper clamping component 2 has a second through hole through its inner and outer surfaces, and the second fastening bolt 4 is disposed in the second through hole of the two upper clamping components 2, and the two upper clamping components 2 are clamped by the second fastening bolt 4.

[0027] In this embodiment, a washer 5 is provided on the second fastening bolt 4, and the washer 5 is correspondingly provided in the installation gap between the two upper clamping components 2.

[0028] This invention also provides a near-net-shape forming method for unidirectional stiffened wall panels made of ceramic matrix composites, using a near-net-shape forming mold for unidirectional stiffened wall panels made of ceramic matrix composites, including the following steps: S1: Place the precast unidirectional stiffened wall panel into the mounting slot 101, and assemble the clamping component 2 on the lower wall panel component 1; S2: The lower wall panel assembly 1, the upper clamping assembly 2, and the unidirectional stiffened wall panel preform are placed together in the deposition furnace. Chemical vapor deposition is performed on the surface of the unidirectional stiffened wall panel preform. During the deposition process, the lower wall panel assembly 1 and the upper clamping assembly 2 jointly restrict the deformation of the unidirectional stiffened wall panel preform. The deposition gas permeates evenly from multiple slit holes 201 into the stiffened transition area of ​​the unidirectional stiffened wall panel preform.

[0029] In this embodiment, the unidirectional stiffened wall panel preform is prepared by the following steps: sewing two-dimensional silicon carbide fiber cloth, rolling it into a T-shape, and forming the unidirectional stiffened wall panel preform by longitudinal stitching and cutting.

[0030] In this embodiment, carbon cloth is laid in the mounting groove 101. After the unidirectional stiffened wall panel preform is placed in the mounting groove 101, the carbon cloth wraps the bottom surface and left and right sides of the unidirectional stiffened wall panel preform.

[0031] In this embodiment, during the deposition process, deposition is first carried out at 600℃ until a deposition interface of 500nm is formed in the unidirectional stiffened wall panel preform. Then, deposition is carried out at 800℃-1000℃ until the density of the unidirectional stiffened wall panel preform reaches 1.3~1.5g / cm³. 3 Remove the upper clamping component 2 to obtain a unidirectional stiffened wall panel.

[0032] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A near-net-shape forming mold for a ceramic-based composite unidirectional stiffened wall panel, characterized in that, include: The lower wall panel assembly (1) has a through mounting groove (101) along its length. Two upper clamping components (2) are disposed opposite to each other on the lower wall panel assembly (1). There is an installation gap between the two upper clamping components (2). The mounting groove (101) is connected to the installation gap and forms a T-shaped deposition cavity. The unidirectional stiffened wall panel preform is disposed in the deposition cavity.

2. The near-net-shape forming mold for a ceramic matrix composite unidirectional stiffened wall panel according to claim 1, characterized in that, The upper clamping component (2) is L-shaped, and it has multiple L-shaped sewing holes (201) in the reinforcing transition area corresponding to the unidirectional reinforced wall panel prefabricated body. The multiple sewing holes (201) are arranged along the length direction of the lower wall panel component (1). One end of the sewing hole (201) is connected to the reinforcing transition area, and the other end is connected to the outside.

3. The near-net-shape forming mold for a ceramic matrix composite unidirectional stiffened wall panel according to claim 2, characterized in that, The upper clamping assembly (2) has a first through hole through the upper and lower surfaces, and the lower wall panel assembly (1) has a second through hole corresponding to the first through hole. A first fastening bolt (3) is provided in the first through hole and the second through hole, and the upper clamping assembly (2) and the lower wall panel assembly (1) are clamped by the first fastening bolt (3).

4. The near-net-shape forming mold for a ceramic matrix composite unidirectional stiffened wall panel according to claim 2, characterized in that, The bottom of the upper clamping assembly (2) is provided with a positioning boss (202), and the lower wall panel assembly (1) is provided with a positioning groove (102) corresponding to the positioning boss (202). The positioning boss (202) and the positioning groove (102) engage.

5. The near-net-shape forming mold for a ceramic matrix composite unidirectional stiffened wall panel according to claim 2, characterized in that, The upper clamping assembly (2) has a second through hole through its inner and outer surfaces. The second fastening bolt (4) is set in the second through hole of the two upper clamping assemblies (2) and the two upper clamping assemblies (2) are clamped by the second fastening bolt (4).

6. The near-net-shape forming mold for a ceramic matrix composite unidirectional stiffened wall panel according to claim 5, characterized in that, The second fastening bolt (4) is provided with a washer (5), which is correspondingly provided in the installation gap between the two upper clamping components (2).

7. A near-net-shape forming method for a ceramic matrix composite unidirectional stiffened wall panel, characterized in that, The near-net-shape forming mold for ceramic matrix composite unidirectional stiffened wall panels according to any one of claims 2-6 includes the following steps: S1: Place the precast unidirectional stiffened wall panel into the mounting groove (101) and assemble the clamping assembly (2) on the lower wall panel assembly (1). S2: The lower wall panel assembly (1), the upper clamping assembly (2) and the unidirectional stiffened wall panel preform are placed together in the deposition furnace, and chemical vapor deposition is performed on the surface of the unidirectional stiffened wall panel preform. During the deposition process, the lower wall panel assembly (1) and the upper clamping assembly (2) jointly restrict the deformation of the unidirectional stiffened wall panel preform, and the deposition gas permeates evenly from multiple slit holes (201) into the stiffened transition area of ​​the unidirectional stiffened wall panel preform.

8. The near-net-shape forming method for a ceramic matrix composite unidirectional stiffened wall panel according to claim 7, characterized in that, The unidirectional reinforced wall panel preform is prepared by the following steps: sewing two-dimensional silicon carbide fiber cloth, rolling it into a T-shape, and forming a unidirectional reinforced wall panel preform by longitudinal stitching and cutting.

9. The near-net-shape forming method for a ceramic matrix composite unidirectional stiffened wall panel according to claim 7, characterized in that, Carbon cloth is laid in the installation groove (101). After the unidirectional reinforced wall panel preform is placed into the installation groove (101), the carbon cloth wraps the bottom surface and left and right sides of the unidirectional reinforced wall panel preform.

10. The near-net-shape forming method for a ceramic matrix composite unidirectional stiffened wall panel according to claim 7, characterized in that, During the deposition process, deposition was first carried out at 600℃ until a deposition interface of 500 nm was formed in the unidirectional stiffened wall panel preform. Then, deposition was carried out at 800℃-1000℃ until the density of the unidirectional stiffened wall panel preform reached 1.3~1.5 g / cm³. 3 Remove the upper clamping assembly (2) to obtain a unidirectional stiffened wall panel.

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