Preparation method of ceramic matrix composite material connecting piece

Abstract

The invention discloses a preparation method of a ceramic-based composite material connecting piece, which comprises the following steps: S1, pretreatment: weaving ceramic-based composite material fibers into a preform with the same shape as the connecting piece; s2, correcting and shaping, wherein a correcting tool is used for conducting mold pressing correcting and shaping on the prefabricated body; s3, primary vapor deposition: putting the corrected and shaped preform into vapor deposition equipment; s4, dipping and curing: putting the prefabricated body subjected to primary vapor deposition into dipping liquid for cracking, and curing to obtain a blank body of the connecting piece; s5, surface treatment is conducted, specifically, the surface of the blank body is subjected to grinding and polishing treatment; and S6, secondary vapor deposition is conducted, specifically, vapor deposition is conducted on the blank body subjected to surface treatment again, a functional coating is deposited on the surface of the blank body, and the connecting piece meeting the size requirement is obtained. The connecting piece prepared from the ceramic-based composite material according to the method has the characteristics of light weight, high heat-resistant temperature, high corrosion resistance, high material strength and the like after being formed.

Description

Technical Field

[0001] The invention relates to the technical field of connector production, and in particular to a method for preparing a ceramic-based composite connector. Background Art

[0002] With the rapid development of aerospace technology, aircraft engines, as key power devices, are the highest-end products in the field of equipment manufacturing. In the turbine engine structure of aircraft engines, the turbine system is the system with the largest thermal load and nuclear power load in the engine. It is characterized by high output power, high operating temperature, light weight requirements, strong corrosion resistance, and high material strength. The connection parts of the turbine shaft are one of the components with higher operating temperatures in the turbine system.

[0003] The connectors of turbine shafts need to work stably for a long time in extremely high temperature, high pressure and highly corrosive working environments. Ordinary metal connectors cannot meet these requirements, which places stringent demands on the material's high temperature resistance, oxidation resistance, mechanical strength and service life. Therefore, the development of connectors suitable for aircraft engine turbine shafts has become one of the key technical challenges in the development of modern aerospace technology. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a ceramic-based composite material connector. The connector prepared by the ceramic-based composite material according to the method has the characteristics of light weight, high heat resistance, strong corrosion resistance, high material strength, etc. after molding. At the same time, compared with metal materials, the ceramic-based composite material has high stability, longer service life and corrosion resistance in a high-temperature gas environment.

[0005] In order to solve the above technical problems, the present invention adopts the following solutions:

[0006] A method for preparing a ceramic matrix composite material connector comprises the following steps:

[0007] S1: pretreatment, using ceramic matrix composite fiber to weave into a preform with the same shape as the connecting part;

[0008] S2: Correction and shaping: using a correction tool to perform mold correction and shaping on the preform;

[0009] S3: initial vapor deposition, placing the corrected and shaped preform into the vapor deposition equipment;

[0010] S4: impregnation and curing, placing the preform after the primary vapor deposition into an impregnation liquid for cracking and curing to obtain a blank body of the connector;

[0011] S5: Surface treatment: grinding and polishing the surface of the blank;

[0012] S6: Secondary vapor deposition: vapor deposition is performed again on the surface treated blank to deposit a functional coating on the surface of the blank to obtain a connector that meets the size requirements.

[0013] In this scheme, the purpose of pretreatment is to provide a shape and material basis for subsequent processing steps. Ceramic-based composite fiber is used and woven according to the shape of the connector to form a preform. This step ensures that the shape of the preform matches the shape of the final product (connector) and utilizes the excellent performance of the ceramic-based composite material. The purpose of correction and shaping is to ensure that the shape of the preform is accurate and provides a stable basis for subsequent deposition and curing steps. The preform is molded and corrected by special correction tooling to adjust the shape of the preform to meet the predetermined requirements. The purpose of the initial vapor deposition is to form a base coating on the surface of the preform to provide an attachment point for subsequent steps. The corrected and shaped preform is placed in a vapor deposition device, and a coating is deposited on the surface of the preform by vapor deposition technology. The purpose of impregnation and curing is to allow the preform to be impregnated with the impregnation liquid through the impregnation and cracking curing process. The preforms are bonded together to enhance the structural strength of the preforms and form a blank body of the connector. The preform after the initial vapor deposition is placed in an impregnation liquid. Through the cracking and solidification process, the components in the impregnation liquid are tightly combined with the preform to form a more solid structure. The purpose of the surface treatment is to further improve the surface quality of the blank and provide a suitable substrate for the subsequent coating deposition. The blank is ground and polished to remove surface defects and unevenness to achieve a predetermined surface finish. The purpose of the secondary vapor deposition is to deposit a layer of functional coating on the surface of the blank to meet specific performance requirements. The coating material can be a thin film material with enhanced properties, such as nitrides, carbides, diamond coatings, ceramic coatings, etc. The surface treated blank is subjected to secondary vapor deposition. Through this step, a coating with specific functions (such as wear resistance, corrosion resistance, high temperature resistance, etc.) is formed on the surface of the blank. This coating not only improves the surface performance of the connector, but also ensures that the thickness of the connector meets the requirements after secondary vapor deposition. It also improves the overall strength and performance of the connector through integrated weaving molding. Through impregnation-curing-cracking, it can significantly improve the wear resistance, strength, corrosion resistance and fatigue life of the ceramic-based composite connector to meet the use requirements under harsh working conditions.

[0014] Furthermore, in S2, the correction and shaping is specifically: when the correction tool initially extrude the preform, the preform can automatically align to achieve shape correction, and the preform continues to be extruded after automatically aligning to achieve shaping.

[0015] Furthermore, the correction tooling includes a base, a top surface of the base is provided with a rotatable first bracket, movable second brackets are provided on both sides of the first bracket, the first bracket is provided with an inner mold for mounting the preform, the second bracket is provided with an outer mold adapted to the shape of the preform, and also includes a telescopic cylinder for driving the outer mold and the inner mold to clamp the preform and automatically align the preform at the same time.

[0016] Furthermore, the telescopic cylinder is installed on the support rods on both sides of the base, and the telescopic cylinder is located on the outside of the first bracket. The telescopic cylinder horizontally drives the outer mold to approach the inner mold until the preform is clamped with the inner mold. Under the action of the clamping force, the inner mold rotates so that the preform is adapted to the inner mold and automatically aligned.

[0017] Furthermore, the second bracket is in sliding contact with the base, and the base is provided with a slide groove adapted to the bottom end of the second bracket, and the bottom of the second bracket is provided with a waist-shaped hole, which passes through the bottom end of the second bracket from top to bottom, and the base is provided with an internal threaded hole. The bottom end of the second bracket is connected to the base through a locking bolt, and the locking bolt passes through the waist-shaped hole and is threadedly connected to the internal threaded hole.

[0018] Furthermore, a bearing is provided in the middle of the first bracket so that the parts above and below the bearing can rotate relatively, and a mounting cavity for mounting the first bracket is provided on the top surface of the base.

[0019] Furthermore, the shape of the inner mold is adapted to the inner cavity of the preform, and the inner mold is composed of an upper square part and a lower circular part. The four corners of the square part are arc corners, and an arc transition zone is formed in the connecting area between the square part and the circular part. The square part and the circular part are integrally formed.

[0020] Furthermore, the interface deposit of the initial vapor deposition is boron nitride, the boron nitride interface deposition process is 700-800℃ / 10±5h, the atmosphere gas is BCl3, the gas delivery rate is 1.5-2.5L / min, NH3, the gas delivery rate is 1.5-2.5L / min, argon, the gas delivery rate is 1.5-3.5L / min, and hydrogen gas delivery rate is 1.5-3.5L / min.

[0021] Furthermore, the interface deposit of the secondary vapor deposition is silicon nitride, the silicon nitride interface deposition process is 900-1100°C / / 30±10h, the atmosphere gas is methyltrichlorosilane, the gas delivery rate is 1-5L / min, nitrogen, the gas delivery rate is 1-5L / min, and the hydrogen gas delivery rate is 1-5L / min.

[0022] Furthermore, the impregnation liquid is prepared in a ratio of xylene: polycarbosilane: DVB = 5:2:1, and the preform after the initial vapor deposition is placed in the impregnation liquid to start the PIP process. The impregnation process is carried out in a vacuum high-pressure impregnation tank at a temperature of 30-60°C, a time of 1-1.5h, and a pressure impregnation of 4±2Mpa. The subsequent curing also uses a vacuum high-pressure impregnation tank, a curing temperature of 180-240°C / 4±1h, and a curing pressure of 5.0±2.0Mpa. Finally, the equipment used for cracking is a vacuum atmosphere box-type resistance furnace and a double-chamber horizontal oil-quenched air-cooled vacuum furnace. The cracking temperature is 900-1300°C, and the cracking pressure is 0.05-0.07Mpa. The PIP process needs to be cycled multiple times.

[0023] The present invention has the beneficial effects:

[0024] 1. In the present invention, the overall strength and performance of the connector are improved through integrated weaving molding, and the wear resistance, strength, corrosion resistance and fatigue life of the ceramic-based composite connector can be significantly improved through multiple cycles of impregnation-curing-cracking process to meet the use requirements under harsh working conditions.

[0025] 2. The rotatable inner mold enables the preform to be automatically positioned and aligned according to the outer shape during molding, avoiding the distortion and deformation of the complex surface preform during the molding process, and ensuring that the shape and size of the later molded connector meet the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the method flow of the present invention;

[0027] Figure 2 It is a structural diagram of the correction tooling;

[0028] Figure 3 Schematic diagram of the top view of the base;

[0029] Figure 4 This is a distribution structure diagram of waist-shaped holes at the bottom of the second bracket;

[0030] Figure 5 It is a structural schematic diagram of the inner mold;

[0031] Figure 6 This is a schematic diagram of the structure of the preform.

[0032] Figure markings: 1-inner mold, 101-square part, 102-circular part, 2-arc-shaped transition zone, 3-circular mouth, 4-inner cavity, 5-preform, 6-square mouth, 7-base, 8-bearing, 9-first bracket, 10-locking bolt, 11-outer mold, 12-second bracket, 13-telescopic cylinder, 14-support rod, 15-slide groove, 16-installation cavity, 17-inner threaded hole, 18-waist-shaped hole. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0034] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "longitudinal", "lateral", "horizontal", "inside", "outside", "front", "back", "top", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0035] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed", "opened", "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Example

[0037] A method for preparing a ceramic matrix composite material connector comprises the following steps:

[0038] S1: pretreatment, using ceramic matrix composite fiber to weave into a preform 5 with the same shape as the connecting part;

[0039] S2: Correction and shaping: using a correction tool to perform mold correction and shaping on the preform 5;

[0040] S3: initial vapor deposition, placing the corrected and shaped preform 5 into a vapor deposition device;

[0041] S4: impregnation and curing, placing the preform 5 after the initial vapor deposition into an impregnation liquid for cracking and curing to obtain a blank body of the connector;

[0042] S5: Surface treatment: grinding and polishing the surface of the blank;

[0043] S6: Secondary vapor deposition: vapor deposition is performed again on the surface treated blank to deposit a functional coating on the surface of the blank to obtain a connector that meets the size requirements.

[0044] In this embodiment, Figure 1As shown, the purpose of pretreatment is to provide a shape and material basis for subsequent processing steps. Ceramic-based composite fiber is used and woven according to the shape of the connector to form a preform 5. This step ensures that the shape of the preform 5 matches the shape of the final product (connector). At this time, the thickness of the preform 5 cannot meet the requirements of the finished product. The preform 5 formed by the weaving process constitutes the skeleton layer of the finished connector. The preform 5 has the characteristics of ceramic-based composite materials such as light weight, high heat resistance, strong corrosion resistance, high material strength, and designable strength. At the same time, compared with metal materials, ceramic-based composite materials have the advantages of high stability, long service life and corrosion resistance in high-temperature gas environments. Therefore, the connection of ceramic-based composite materials is the best material for turbine shaft connectors. The preform 5 is a tubular structure with a square opening 6 at one end and a circular opening 3 at the other end, and the middle part is a cavity; the purpose of correction and shaping is to ensure that the shape of the preform 5 is accurate and correct, and to provide a stable foundation for subsequent deposition and curing steps. The preform 5 is molded and corrected using a special correction tool to adjust the shape of the preform 5 to meet the predetermined requirements; the purpose of the initial vapor deposition is to form a base coating on the surface of the preform 5 to provide an attachment point for subsequent steps, and the preform 5 after correction and shaping is placed in a vapor deposition device, and a layer of coating is deposited on the surface of the preform 5 by vapor deposition technology; the purpose of impregnation curing is to allow the preform 5 to be impregnated with the impregnated preform 5 through the impregnation and cracking curing process. The preform 5 is bonded together by the impregnation liquid to enhance the structural strength of the preform 5 and form a blank body of the connector. The preform 5 after the initial vapor deposition is placed in the impregnation liquid. Through the cracking and solidification process, the components in the impregnation liquid are tightly combined with the preform 5 to form a more solid structure; the purpose of surface treatment is to further improve the surface quality of the blank and provide a suitable substrate for subsequent coating deposition. The blank is ground and polished to remove surface defects and unevenness to achieve a predetermined surface finish; the purpose of secondary vapor deposition is to deposit a layer of functional coating on the surface of the blank to meet specific performance requirements. The coating material can be a thin film material with enhanced properties, such as nitride, carbide, diamond coating, ceramic coating, etc. The surface treated blank is subjected to secondary vapor deposition. Through this step, a coating with specific functions (such as wear resistance, corrosion resistance, high temperature resistance, etc.) is formed on the surface of the blank. This coating not only improves the surface performance of the connector, but also ensures that the thickness of the connector meets the requirements after secondary vapor deposition. It also improves the overall strength and performance of the connector through integrated weaving molding. Through impregnation-curing-cracking, it can significantly improve the wear resistance, strength, corrosion resistance and fatigue life of the ceramic-based composite connector to meet the use requirements under harsh working conditions.

[0045] Furthermore, in S2, the correction and shaping is specifically: when the correction tool initially extrude the preform 5, the preform 5 can automatically align to achieve shape correction, and the preform 5 continues to be extruded after automatically aligning to achieve shaping.

[0046] Specifically, correction and shaping is actually a two-step continuous process. During the extrusion of the preform 5, the correction tool can first realize automatic alignment of the preform 5, so that the woven preform 5 has the same shape as the finished connector. After automatic alignment, the correction tool will continue to extrude the preform 5 to shape the corrected preform 5. In this way, in the subsequent processing steps, the shape of the preform 5 will not change again, ensuring the molding quality of the later products.

[0047] Furthermore, the correction tooling includes a base 7, a top surface of the base 7 is provided with a rotatable first bracket 9, movable second brackets 12 are provided on both sides of the first bracket 9, the first bracket 9 is provided with an inner mold 1 for mounting the preform 5, the second bracket 12 is provided with an outer mold 11 adapted to the shape of the preform 5, and also includes a telescopic cylinder 13 for driving the outer mold 11 and the inner mold 1 to clamp the preform 5 and simultaneously automatically align the preform 5.

[0048] Specifically, the preform 5 is the core structure of the connecting member. Figure 6 As shown, one end of the preform 5 is a square opening 6, and the other end is a circular opening 3. The square opening 6 and the circular opening 3 are connected, that is, the interior of the preform 5 has an inner cavity 4, and the size of the inner cavity 4 is adapted to the inner mold 1. The preform 5 is directly mounted on the inner mold 1. The preform 5 is woven from a fiber bundle of a ceramic-based composite material. The preform 5 itself has a certain rigidity, so that the preform 5 is not easy to collapse when it is mounted on the inner mold 11, which is convenient for automatic alignment during subsequent extrusion. Having a certain rigidity refers to a woven basket, backpack, etc., which can maintain the corresponding shape after weaving, but its shape needs to be further shaped by mold extrusion. The base 7 serves as the foundation of the entire tooling and provides a stable support platform, such as Figure 2As shown, the first bracket 9 is mounted on the top surface of the base 7 and can rotate, providing a basis for the subsequent alignment of the preform 5. The second bracket 12 is arranged on both sides of the first bracket 9 and can move laterally. By adjusting the position of the second bracket 12, it can be ensured that the outer mold 11 is perfectly adapted to the shape of the preform 5, which facilitates the subsequent clamping and alignment operations. The inner mold 1 is mounted on the first bracket 9 for mounting the preform 5. The shape and size of the inner mold 1 must match the interior of the preform 5 to ensure that the preform 5 maintains a stable shape during the processing. The outer mold 11 Installed on the second bracket 12 and adapted to the shape of the preform 5, the outer mold 11 not only fixes the preform 5, but also provides necessary support and protection for the preform 5 during the processing. The telescopic cylinder 13 is responsible for driving the outer mold 11 to move and clamp the preform 5 at the same time as the inner mold 1. When clamping, the air in the preform 5 can be squeezed out, making the gap between the fiber bundles of the ceramic-based composite material smaller, the preform 5 more dense, and the strength of the later formed connecting parts better. When clamping, the rotation of the inner mold 1 can automatically adjust the position of the preform 5 to achieve alignment. The telescopic cylinder 13 makes the outer mold 11 approach the preform 5 until it clamps the preform 5 with the inner mold 1, ensuring the stability of the preform 5 during the processing, ensuring that the preform 5 is evenly stressed to avoid stress concentration and deformation. While clamping the preform 5, the clamping force generated causes the inner mold 1 to rotate so that the preform 5 can fine-tune its position according to its own shape, and finally the preform 5 automatically adjusts to the correct position. This alignment operation can ensure that the preform 5 maintains an accurate shape and size during the subsequent processing, avoids the complex surface of the preform 5 from twisting and deformation during the molding process, and ensures that the quality of the preform 5 formed subsequently meets the requirements.

[0049] Furthermore, the telescopic cylinder 13 is installed on the support rods 14 on both sides of the base 7. The telescopic cylinder 13 is located on the outside of the first bracket 9. The telescopic cylinder 13 horizontally drives the outer mold 11 to approach the inner mold 1 until the preform 5 is clamped with the inner mold 1. Under the action of the clamping force, the inner mold 1 rotates so that the preform 5 is adapted to the inner mold 1 and automatically aligned.

[0050] Specifically, the telescopic cylinder 13 is fixedly mounted on the support rods 14 on both sides of the base 7, ensuring that the telescopic cylinder 13 has sufficient stability and supporting force during operation. The telescopic cylinder 13 is located on the outside of the second bracket 12. The telescopic cylinder 13 drives the outer mold 11 to approach the inner mold 1 in a horizontal manner. This driving method ensures the uniform distribution of the clamping force and avoids the deformation or damage of the preform 5 caused by uneven clamping force. When the outer mold 11 gradually approaches the inner mold 1 under the drive of the telescopic cylinder 13, it will clamp the preform 5 together with the inner mold 1. This clamping method not only ensures the stability of the preform 5 during the processing, but also prevents it from deforming under harsh environments such as high temperature and high pressure. Automatic control can be achieved through an external controller (PLC), which can ensure that the pressure applied by the telescopic cylinder 13 is controllable, and the gap between the inner mold 1 and the outer mold 11 can be accurately adjusted. In this way, the molding angle, curved surface and size of the preform 5 during the extrusion molding process can be more accurately controlled to ensure that the preform 5 is evenly stressed to avoid stress concentration and deformation. Under the action of the clamping force, if the position of the preform 5 is incorrect, the wall of its inner cavity 4 will not fit with the inner mold 1. Under the action of pressure, the inner mold 1 will rotate slightly to adapt to the shape of the inner cavity 4 of the preform 5. This adaptive rotation process enables the preform 5 and the inner mold 1 to achieve the best adaptation state and realizes the automatic alignment of the preform 5. This alignment method not only improves the accuracy of the preparation process, but also reduces the need for manual intervention.

[0051] The workflow is optimized to avoid distortion and deformation of the complex surface of the preform 5 during the forming process.

[0052] Specific steps:

[0053] Preparation stage: the preform 5 is placed in the inner mold 1 on the first bracket 9 , and the position of the second bracket 12 is adjusted so that the outer mold 11 roughly matches the shape of the preform 5 .

[0054] Clamping and alignment: Start the telescopic cylinder 13 to make the outer mold 11 approach the inner mold 1 in the horizontal direction until it clamps the preform 5 together with the inner mold 1. Under the action of the clamping force, the inner mold 1 will rotate adaptively to make the preform 5 and the inner mold 11 reach the best adaptation state and realize automatic alignment. After the processing is completed, the remaining processes can be carried out.

[0055] Furthermore, the second bracket 12 is in sliding contact with the base 7, and the base 7 is provided with a slide groove 15 adapted to the bottom end of the second bracket 12, and the bottom of the second bracket 12 is provided with a waist-shaped hole 18, and the waist-shaped hole 18 passes through the bottom end of the second bracket 12 from top to bottom. The base 7 is provided with an internal threaded hole 17, and the bottom end of the second bracket 12 is connected to the base 7 through a locking bolt 10, and the locking bolt 10 passes through the waist-shaped hole 18 and is threadedly connected to the internal threaded hole 17.

[0056] Specifically, Figure 2 As shown, the base 7 is provided with a slide groove 15 adapted to the bottom of the second bracket 12. The second bracket 12 can slide along the length direction of the slide groove 15 under the action of the telescopic cylinder 13, thereby driving the outer mold 11 to approach and clamp the preform 5, as shown in FIG. Figure 4 As shown, a waist-shaped hole 18 is provided on the top surface of the lower end of the second bracket 12, and the waist-shaped hole 18 passes through the lower end of the second bracket 12 from top to bottom. The design of the waist-shaped hole 18 provides additional adjustment space, because the locking bolt 10 can move within a certain range in the long axis direction of the waist-shaped hole 18. Before the preform 5 is clamped, the locking bolt 10 will not lock the second bracket 12 on the base 7. At this time, under the action of the telescopic cylinder 13, there is a relative displacement between the second bracket 12 and the locking bolt 10, so that the outer mold 11 can be close to the preform 5. After the outer mold 11 and the inner mold 1 clamp the preform 5 and the preform 5 is automatically aligned, the locking bolt 10 is tightened to ensure that the position of the second bracket 12 does not change, thereby ensuring that the outer mold 11 and the inner mold 1 can stably clamp the preform 5.

[0057] like Figure 3 As shown, further, a bearing 8 is provided in the middle of the first bracket 9 so that the parts above and below the bearing 8 can rotate relatively, and a mounting cavity 16 for mounting the first bracket 9 is provided on the top surface of the base 7.

[0058] Specifically, the first bracket 9 is equivalent to being divided into two parts, an upper part and an lower part, which can rotate relatively. In this way, when the preform 5 is extruded, the preform 5 can be automatically aligned by rotating the upper part of the first bracket 9 .

[0059] Furthermore, the outer shape of the inner mold 1 is adapted to the inner cavity 4 of the preform 5. The inner mold 1 is composed of an upper square portion 101 and a lower circular portion 102. The four corners of the square portion 101 are arc corners. An arc transition zone 2 is formed in the connecting area between the square portion 101 and the circular portion 102. The square portion 101 and the circular portion 102 are integrally formed.

[0060] Specifically, Figure 5 As shown, the inner mold 1 is composed of a square portion 101 and a circular portion 102. The four outer corners of the square portion 101 are all arc corners, the surface of the circular portion 102 is also an arc surface, and the connecting area between the two is also an arc transition zone 2. In this way, the surface of the entire inner mold 1 is streamlined. In this way, when the preform 5 is clamped, the preform 5 and the inner mold 1 can rotate relative to each other more flexibly, so that the automatic alignment of the preform 5 is faster and more accurate.

[0061] Specifically, the outer mold 11 is composed of two symmetrical templates. This symmetrical design not only enables the outer mold 11 to form a uniform clamping force when it is closed, but also improves the overall strength and stability of the outer mold 11. The shape of the cavity formed when the two templates are closed is completely compatible with the shape of the preform 5. This design ensures that the preform 5 can be tightly wrapped and fixed during the processing, thereby avoiding processing errors caused by looseness or deformation. Since the outer mold 11 is composed of two independent templates, it can adapt to preforms 5 of different shapes and sizes by adjusting the spacing or angle between the templates. This adjustability improves the flexibility and adaptability of the preparation tooling, allowing it to be applied to a wider range of preparation scenarios.

[0062] Clamping and fixing: When the telescopic cylinder 13 drives the outer mold 11 to approach the inner mold 1, the two molds will gradually close and clamp the preform 5. Since the shape of the inner cavity 4 is adapted to the shape of the preform 5, it can be ensured that the preform 5 will not be subjected to excessive pressure or deformation during the clamping process.

[0063] Automatic alignment: Under the action of the clamping force, the inner mold 1 will rotate adaptively to achieve the best fit with the preform 5. At the same time, since the cavity of the outer mold 11 is completely compatible with the shape of the preform 5, the preform 5 can also be automatically aligned to a certain extent. This alignment method not only improves the accuracy and efficiency of the preparation process, but also reduces the need for manual intervention.

[0064] Furthermore, the interface deposit of the initial vapor deposition is boron nitride, the boron nitride interface deposition process is 700-800℃ / 10±5h, the atmosphere gas is BCl3, the gas delivery rate is 1.5-2.5L / min, NH3, the gas delivery rate is 1.5-2.5L / min, argon, the gas delivery rate is 1.5-3.5L / min, and hydrogen gas delivery rate is 1.5-3.5L / min.

[0065] Furthermore, the interface deposit of the secondary vapor deposition is silicon nitride, the silicon nitride interface deposition process is 900-1100°C / / 30±10h, the atmosphere gas is methyltrichlorosilane, the gas delivery rate is 1-5L / min, nitrogen, the gas delivery rate is 1-5L / min, and the hydrogen gas delivery rate is 1-5L / min.

[0066] Furthermore, the impregnation liquid is prepared according to the ratio of xylene: polycarbosilane: DVB = 5:2:1, and the preform 5 after the initial vapor deposition is placed in the impregnation liquid to start the PIP process. The impregnation process is carried out in a vacuum high-pressure impregnation tank at a temperature of 30-60°C, a time of 1-1.5h, and a pressure impregnation of 4±2Mpa. The subsequent curing also uses a vacuum high-pressure impregnation tank, a curing temperature of 180-240°C / 4±1h, and a curing pressure of 5.0±2.0Mpa. Finally, the equipment used for cracking is a vacuum atmosphere box-type resistance furnace and a double-chamber horizontal oil-quenched air-cooled vacuum furnace. The cracking temperature is 900-1300°C and the cracking pressure is 0.05-0.07Mpa. The PIP process needs to be cycled multiple times.

[0067] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. According to the technical essence of the present invention, within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a ceramic matrix composite connector, characterized in that: The following steps are involved: S1: pretreatment, using ceramic matrix composite fiber to weave into a preform (5) with the same shape as the connecting part; S2: Correction and shaping, using a correction tool to perform mold correction and shaping on the preform (5); S3: initial vapor deposition, placing the corrected and shaped preform (5) into a vapor deposition device; S4: impregnation and solidification, placing the preform (5) after the primary vapor deposition into an impregnation liquid for cracking and solidification to obtain a blank body of the connector; S5: Surface treatment: grinding and polishing the surface of the blank; S6: Secondary vapor deposition: vapor deposition is performed again on the surface treated blank to deposit a functional coating on the surface of the blank to obtain a connector that meets the size requirements.

2. The method for preparing a ceramic matrix composite connector according to claim 1, characterized in that: In S2, the correction and shaping specifically includes: when the correction tool initially extrude the preform (5), the preform (5) can automatically align to achieve shape correction; after the preform (5) is automatically aligned, it continues to be extruded to achieve shaping.

3. The method for preparing a ceramic matrix composite connector according to claim 2, characterized in that: The correction tool comprises a base (7), a rotatable first bracket (9) is provided on the top surface of the base (7), movable second brackets (12) are provided on both sides of the first bracket (9), an inner mold (1) for mounting a preform (5) is provided on the first bracket (9), an outer mold (11) adapted to the shape of the preform (5) is provided on the second bracket (12), and a telescopic cylinder (13) is also included for driving the outer mold (11) and the inner mold (1) to clamp the preform (5) and simultaneously automatically align the preform (5).

4. The method for preparing a ceramic matrix composite connector according to claim 3, characterized in that: The telescopic cylinder (13) is installed on the support rods (14) on both sides of the base (7). The telescopic cylinder (13) is located outside the first bracket (9). The telescopic cylinder (13) drives the outer mold (11) to move closer to the inner mold (1) horizontally until the preform (5) is clamped with the inner mold (1). Under the action of the clamping force, the inner mold (1) rotates so that the preform (5) and the inner mold (1) are adapted and automatically aligned.

5. The method for preparing a ceramic matrix composite connector according to claim 4, characterized in that: The second bracket (12) is in sliding contact with the base (7); the base (7) is provided with a slide groove (15) adapted to the bottom end of the second bracket (12); the bottom of the second bracket (12) is provided with a waist-shaped hole (18); the waist-shaped hole (18) passes through the bottom end of the second bracket (12) from top to bottom; the base (7) is provided with an internal threaded hole (17); the bottom end of the second bracket (12) and the base (7) are connected by a locking bolt (10); the locking bolt (10) passes through the waist-shaped hole (18) and is threadedly connected to the internal threaded hole (17).

6. The method for preparing a ceramic matrix composite connector according to claim 4, characterized in that: A bearing (8) is provided in the middle of the first bracket (9), so that the parts above and below the bearing (8) can rotate relative to each other, and a mounting cavity (16) for mounting the first bracket (9) is provided on the top surface of the base (7).

7. The method for preparing a ceramic matrix composite connector according to claim 3, characterized in that: The outer shape of the inner mold (1) is adapted to the inner cavity (4) of the preform (5); the inner mold (1) is composed of an upper square portion (101) and a lower circular portion (102); the four corners of the square portion (101) are arc corners; an arc-shaped transition zone (2) is formed in the connection area between the square portion (101) and the circular portion (102); and the square portion (101) and the circular portion (102) are integrally formed.

8. The method for preparing a ceramic matrix composite connector according to claim 1, characterized in that: The interface deposit of the initial vapor deposition is boron nitride, the boron nitride interface deposition process is 700-800℃ / 10±5h, the atmosphere gas is BCl3, the gas delivery rate is 1.5-2.5L / min, NH3, the gas delivery rate is 1.5-2.5L / min, argon, the gas delivery rate is 1.5-3.5L / min, and hydrogen gas delivery rate is 1.5-3.5L / min.

9. The method for preparing a ceramic matrix composite connector according to claim 1, characterized in that: The interface deposit of the secondary vapor deposition is silicon nitride, the silicon nitride interface deposition process is 900-1100°C / / 30±10h, the atmosphere gas is methyltrichlorosilane, the gas delivery rate is 1-5L / min, nitrogen, the gas delivery rate is 1-5L / min, and hydrogen gas delivery rate is 1-5L / min.

10. The method for preparing a ceramic matrix composite connector according to claim 1, characterized in that: The impregnation liquid is prepared according to the ratio of xylene: polycarbosilane: DVB = 5:2:1, and the preform (5) after the initial vapor deposition is placed in the impregnation liquid to start the PIP process. The impregnation process is carried out in a vacuum high-pressure impregnation tank at a temperature of 30-60°C, a time of 1-1.5h, and a pressure impregnation of 4±2Mpa. The subsequent curing also uses a vacuum high-pressure impregnation tank, the curing temperature is 180-240°C / 4±1h, and the curing pressure is 5.0±2.0Mpa. Finally, the equipment used for cracking is a vacuum atmosphere box-type resistance furnace and a double-chamber horizontal oil-quenched air-cooled vacuum furnace, the cracking temperature is 900-1300°C, and the cracking pressure is 0.05-0.07Mpa. The PIP process needs to be cycled multiple times.

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