Hollow hexahedral member preform shaping mold for ceramic matrix composite and method for manufacturing hollow hexahedral member

Abstract

The application provides a ceramic matrix composite hollow hexahedral member preform shaping mold and a method for preparing a hollow hexahedral member, and can solve the problem of cracks in the hollow hexahedral member preform, uneven mold holding force and low fiber cloth adhesion rate when shaping with the existing mold, which leads to product delamination, porosity and affects the mechanical properties of the product. The shaping mold comprises an inner mold assembly, an outer mold assembly and a fastening assembly. The inner mold assembly comprises a left inner mold, a right inner mold, an inner mold adjusting plate, a windowed front panel and a first positioning pin. The left inner mold comprises upper, right, lower and left frames which are sequentially closed into a rectangular frame structure, and a windowed back panel arranged on the back side of the rectangular frame structure. The right inner mold has the same structure as the left inner mold. The windowed front panel is buckled on the front side of the rectangular frame structure. The outer mold assembly is arranged outside the inner mold assembly and comprises a front cover plate, an upper outer mold and a lower outer mold which are buckled into a rectangular frame with a back cover plate. The front cover plate is buckled on the front side of the rectangular frame.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of ceramic matrix composite component preform shaping mould and the preparation method of component, specifically relates to a kind of ceramic matrix composite hollow hexahedron component preform shaping mould and the preparation method of hollow hexahedron component. BACKGROUND

[0002] The shaping of ceramic matrix composite component preform is mainly realized by laying multiple layers of carbon fiber cloth or silicon carbide fiber cloth on the predetermined rigid curved surface of graphite shaping mould, and performing mould closing operation. However, during the shaping process of hollow hexahedron component preform, due to the difference between the thermal expansion coefficients of the existing hollow hexahedron type graphite shaping mould and the hollow hexahedron component preform, cracks are prone to occur in the hollow hexahedron component preform during subsequent high temperature treatment. In addition, due to the complex curved surface characteristics of the hollow hexahedron component preform, the holding force of the graphite shaping mould is often uneven and the adhesion rate with the fiber cloth is low, which leads to uneven deposition of the subsequent interface layer and matrix layer, and finally the hollow hexahedron component product has defects such as delamination and porosity, affecting the mechanical properties of the product. SUMMARY

[0003] The purpose of the present application is to solve the technical problems of cracks in the hollow hexahedron component preform, uneven holding force of the graphite shaping mould and low adhesion rate with the fiber cloth when using the existing hollow hexahedron type graphite shaping mould for shaping, which leads to defects such as delamination and porosity in the hollow hexahedron component product, affecting the mechanical properties of the product, and to provide a kind of ceramic matrix composite hollow hexahedron component preform shaping mould and the preparation method of hollow hexahedron component.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] A kind of ceramic matrix composite hollow hexahedron component preform shaping mould, which is characterized in that:

[0006] It comprises an inner mould assembly, an outer mould assembly and a fastening assembly for pressing the outer mould assembly;

[0007] The inner mold assembly comprises a left inner mold, a right inner mold, an inner mold adjusting plate, two windowed front panels, and at least two first positioning pins; the left inner mold comprises an upper frame, a right frame, a lower frame, and a left frame which are sequentially closed into a rectangular frame structure, and a windowed back panel arranged at the back side of the rectangular frame structure; the right frame of the left inner mold is provided with at least two first positioning holes; the right inner mold has the same structure as the left inner mold, and the left frame of the right inner mold is provided with at least two second positioning holes; the first positioning pin can sequentially pass through the first positioning hole, the inner mold adjusting plate, and the second positioning hole; the two windowed front panels are respectively buckled at the front side of the rectangular frame structure of the left inner mold and the rectangular frame structure of the right inner mold; the height of the inner mold adjusting plate in the up-down direction is less than the height of the two windowed front panels along the window edge in the up-down direction, and the width of the inner mold adjusting plate in the front-back direction is less than the distance between the windowed front panel and the windowed back panel;

[0008] The use profile of the inner mold assembly is provided with sewing holes;

[0009] The outer mold assembly is arranged outside the inner mold assembly, and the use profile of the outer mold assembly is matched with the use profile of the inner mold assembly; the outer mold assembly comprises an upper outer mold, a lower outer mold, and a front cover plate; the upper outer mold and the lower outer mold are symmetrical structures and are buckled into a rectangular frame with a back cover plate through a plurality of connecting tabs; the front cover plate is buckled at the front side of the rectangular frame; the front cover plate and the back cover plate are both windowed structures;

[0010] The front cover plate, the windowed front panel, the windowed back panel, and the back cover plate are sequentially arranged from front to back.

[0011] Further, the use profile of the inner mold assembly in the thickness direction is an equal-wall-thickness profile, and the wall thickness is 5-10 mm;

[0012] The use profile of the outer mold assembly in the thickness direction is an equal-wall-thickness profile, and the wall thickness is 8-12 mm;

[0013] The wall thickness of the inner mold adjusting plate is 1-5 mm.

[0014] Further, the left frame, the lower frame of the left inner mold, and the lower frame, the right frame of the right inner mold are provided with a plurality of damage grooves;

[0015] The aperture of the sewing hole is 1.5-10 mm, and the center distance between adjacent sewing holes is 1-15 mm.

[0016] Further, the fastening assembly comprises a plurality of reinforcing frames and wedge-shaped blocks; the reinforcing frame is sleeved outside the outer mold assembly, and the wedge-shaped block is arranged between the reinforcing frame and the outer mold assembly to press the outer mold assembly in the front-back direction;

[0017] The first detection reference hole is arranged on the windowed back panel; the second detection reference hole corresponding to the first detection reference hole is arranged on the windowed front panel, the back cover plate and the front cover plate, and the first detection reference hole and the second detection reference hole are used for re-inspection in a factory.

[0018] Further, a plurality of reinforcing ribs are arranged on the front side of the front cover plate and the rear side of the back cover plate.

[0019] The shape of the damage groove is rectangular, square, circular or special-shaped.

[0020] The material of the inner mold adjusting plate is ceramic matrix composite material.

[0021] The materials of the inner mold assembly, the outer mold assembly and the fastening assembly are high-temperature materials; the high-temperature materials are high-strength fine graphite, high-purity graphite or electrode graphite.

[0022] Meanwhile, the application also provides a preparation method of the ceramic matrix composite material hollow hexahedral component, and the speciality of the forming mold based on the above ceramic matrix composite material hollow hexahedral component preform lies in comprising the following steps:

[0023] 1) Assembling the inner mold assembly

[0024] 1.1) gluing the left inner mold and one of the windowed front panels, and gluing the right inner mold and the other windowed front panel;

[0025] 1.2) connecting and gluing the left inner mold, the inner mold adjusting plate and the right inner mold by using the first positioning pin to form the inner mold assembly;

[0026] 2) Forming the hollow hexahedral component preform

[0027] 2.1) calculating the amount of fiber cloth required by the hollow hexahedral component preform, and cutting;

[0028] 2.2) layer by layer laying and flanging the cut fiber cloth on the used surface of the inner mold assembly to obtain the intermediate body of the hollow hexahedral component preform;

[0029] 2.3) combining the intermediate body of the hollow hexahedral component preform and the rectangular frame formed by the upper outer mold and the lower outer mold with the front cover plate to form a trial assembly mold, removing the rectangular frame and the front cover plate after the trial assembly mold meets the requirements, and then sewing and locking edges to obtain the hollow hexahedral component preform;

[0030] 2.4) combining the hollow hexahedral component preform and the rectangular frame formed by the upper outer mold and the lower outer mold, combining the front cover plate on the front side of the rectangular frame, and finally fastening the outer mold assembly by using the fastening assembly;

[0031] 3) Preparing the interface layer and high-temperature treatment

[0032] The interface layer of the fastened hollow hexahedron component preform in step 2.4) is prepared by chemical vapor deposition, then the inner mold adjusting plate is removed, and high temperature treatment is performed;

[0033] 4) Preparation of silicon carbide matrix layer;

[0034] The silicon carbide matrix layer of the treated hollow hexahedron component preform in step 3) is prepared by chemical vapor deposition, and demolding is performed during the process;

[0035] 5) Mechanical processing

[0036] The hollow hexahedron component preform after the preparation of the silicon carbide matrix layer is mechanically processed and subsequently treated to obtain a ceramic matrix composite hollow hexahedron component.

[0037] Further, step 4) specifically comprises the following steps:

[0038] 4.1) Place the treated hollow hexahedron component preform in step 3) in a deposition furnace, and set the furnace pressure to 200-5000 Pa;

[0039] 4.2) Heat to 900-1200℃, and after holding for 1-2h, introduce a mixed gas of trichloromethylsilane, hydrogen and argon, the flow ratio of trichloromethylsilane, hydrogen and argon being 1-10:10-20:10-30, deposit for 30-80h, continue to hold for 2h, and then reduce to room temperature;

[0040] 4.3) Repeat step 4.2) two to four times, take out the hollow hexahedron component preform with the silicon carbide matrix layer, and remove the inner mold assembly by knocking the inner mold assembly;

[0041] 4.4) Place the hollow hexahedron component preform with the removed inner mold assembly in step 4.3) in a deposition furnace with a furnace pressure of 200-5000 Pa, and perform cyclic deposition according to the process of step 4.2) until the density of the silicon carbide matrix layer is 1.75-1.8g / cm 3 , and remove the outer mold assembly.

[0042] Further, step 2.3) specifically comprises the following steps:

[0043] 2.3.1) Try fitting the mold with the hollow hexahedron component preform intermediate and the rectangular frame formed by buckling the upper and lower outer molds;

[0044] 2.3.2) adopt 0.15mm plug gauge to detect the fit gap between the hollow hexahedral component preform intermediate body and the rectangular frame using profile, if the fit gap is ≥0.15mm, then execute step 2.3.3), if the fit gap is <0.15mm, then execute step 2.3.4);

[0045] 2.3.3) disassemble the rectangular frame, add the re-cut fiber cloth at the corresponding position of the using profile of the hollow hexahedral component preform intermediate body, then re-mold with the rectangular frame and return to step 2.3.2);

[0046] 2.3.4) fasten the front cover plate on the front side of the rectangular frame, then adopt the fastening assembly to fasten the outer mold assembly;

[0047] 2.3.5) adopt 0.15mm plug gauge to detect the fit gap between the hollow hexahedral component preform intermediate body and the front cover plate using profile, if the fit gap is ≥0.15mm, then execute step 2.3.6), if the fit gap is <0.15mm, then disassemble the rectangular frame and the front cover plate, then perform sewing and edge locking to obtain the hollow hexahedral component preform;

[0048] 2.3.6) disassemble the front cover plate, add the re-cut fiber cloth at the corresponding position of the using profile of the hollow hexahedral component preform intermediate body, then re-fasten the front cover plate on the front side of the rectangular frame and adopt the fastening assembly to fasten the outer mold assembly, return to step 2.3.5).

[0049] Further, step 3) specifically comprises the following steps:

[0050] 3.1) place the hollow hexahedral component preform fastened in step 2.4) in a deposition furnace, heat to 650-1000℃ under the furnace pressure of 50-1000Pa, after heat preservation for 1-3h, sequentially pass in argon, hydrogen, ammonia and boron trichloride gas for deposition until a hollow hexahedral component preform with a boron nitride interface layer of 150-750nm thickness is obtained, and then reduce to room temperature;

[0051] Or, place the hollow hexahedral component preform fastened in step 2.4) in a deposition furnace, heat to 500-1000℃ under the furnace pressure of 10-70Pa, after heat preservation for 1-3h, sequentially pass in argon and propylene for deposition until a hollow hexahedral component preform with a pyrolytic carbon interface layer of 100-350nm thickness is obtained, and then reduce to room temperature;

[0052] 3.2) Take out the hollow hexahedron component preform after the deposition of step 3.1), remove the first positioning pin, then remove the inner mold adjusting plate, and then reposition and connect the left inner mold and the right inner mold by using the first positioning pin, and finally perform high-temperature treatment at a temperature of 1750-2000 DEG C for 1-5 hours.

[0053] Further, step 5) is specifically:

[0054] The hollow hexahedron component preform after the outer mold assembly is removed in step 4.4) is machined, and then the deposition of the silicon carbide matrix layer is continued according to the method of step 4.1) and step 4.2) until the density of the silicon carbide matrix layer is greater than 2.0 g / cm 3 , and a ceramic matrix composite hollow hexahedron component is prepared.

[0055] The beneficial effects of the present application are:

[0056] 1. The present application provides a ceramic matrix composite hollow hexahedron component preform forming mold, which is a combined structure, which not only improves the machinability of the complex surface of the mold, improves the convenience of transportation and operation, but also effectively reduces the preparation cost. In addition, the holding force of the forming mold is uniform and the adhesion with the fiber cloth is good, which can avoid defects such as delamination and porosity of the hollow hexahedron component product, and greatly improve the mechanical properties of the product.

[0057] 2. The equal wall thickness profile provided in the present application can effectively improve the deposition efficiency and deposition uniformity in the subsequent preparation process, reduce the preparation cost, and further improve the mechanical properties of the product. The damage groove provided in the present application can reduce the difficulty of removing the inner mold assembly, which is beneficial to the removal of the inner mold assembly without affecting the use surface of the preform.

[0058] 3. The reinforcing frame and wedge in the present application can effectively improve the adhesion rate of the mold, which can reach more than 85%, and the thickness difference of different parts of the preform is less than 0.3mm, thereby improving the wall thickness uniformity of the preform in the subsequent chemical vapor deposition process, reducing the risk of delamination, and further improving the mechanical properties of the hollow hexahedron component product. The reinforcing rib in the present application can significantly improve the strength and stiffness of the front cover plate without changing the wall thickness of the front cover plate.

[0059] 4. The present application provides a preparation method of a ceramic matrix composite hollow hexahedron component, which is simple to operate and has high reliability, and can realize high-quality shaping of a complex surface hollow hexahedron component preform. The inner mold adjusting plate is removed before high-temperature treatment, which can avoid cracking of the component preform due to the difference in thermal expansion coefficient between the mold and the ceramic matrix composite. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1 is the installation structure schematic diagram of left inner mold, right inner mold and inner mold adjusting plate in the embodiment of the sizing mold of the hollow hexahedral member preform of the ceramic matrix composite material of the present application;

[0061] Figure 2 is the structure schematic diagram of the inner mold assembly in the embodiment of the sizing mold of the hollow hexahedral member preform of the ceramic matrix composite material of the present application;

[0062] Figure 3 is the structure schematic diagram of the hollow hexahedral member preform intermediate body in step 2.2) of the embodiment of the preparation method of the hollow hexahedral member of the ceramic matrix composite material of the present application;

[0063] Figure 4 is the structure schematic diagram of the upper outer mold and lower outer mold after buckling in the embodiment of the sizing mold of the hollow hexahedral member preform of the ceramic matrix composite material of the present application;

[0064] Figure 5 is the structure schematic diagram of the hollow hexahedral member preform and the upper outer mold and lower outer mold in the embodiment of the preparation method of the hollow hexahedral member of the ceramic matrix composite material of the present application;

[0065] Figure 6 is the structure schematic diagram of the hollow hexahedral member preform, upper outer mold, lower outer mold and front cover plate in the embodiment of the preparation method of the hollow hexahedral member of the ceramic matrix composite material of the present application;

[0066] Figure 7 is the structure schematic diagram of the hollow hexahedral member preform, outer mold assembly and fastening assembly in the embodiment of the preparation method of the hollow hexahedral member of the ceramic matrix composite material of the present application.

[0067] Explanation of reference signs:

[0068] 1-left inner mold; 2-right inner mold; 3-inner mold adjusting plate; 4-destroying groove; 5-first positioning hole; 6-first detection reference hole; 7-windowed front panel; 8-fastening assembly; 9-inner mold assembly; 10-hollow hexahedral member preform; 11-upper outer mold; 12-lower outer mold; 13-connection ear; 14-double head bolt; 15-nut; 16-stiffener; 17-front cover plate; 18-outer mold assembly; 19-stiffening frame; 20-windowed back panel; 21-back cover plate; 22-second detection reference hole; 23-second positioning pin. DETAILED DESCRIPTION

[0069] In designing the molding die for the hollow hexahedral preform of ceramic matrix composite material, the present invention should comprehensively consider factors such as the processability of complex surfaces, the adhesion rate with fiber cloth, the ease of demolding and the protection of the preform during demolding, as well as the uniformity of deposition density during subsequent chemical vapor deposition.

[0070] like Figures 1-7 As shown, a molding die for a preform of a hollow hexahedral component made of ceramic matrix composite material includes an inner mold assembly 9, an outer mold assembly 18, and a fastening assembly 8 for pressing the outer mold assembly 18. Specifically, the inner mold assembly 9 includes a left inner mold 1, a right inner mold 2, an inner mold adjusting plate 3, two window front panels 7, and two first positioning pins. The left inner mold 1 includes an upper frame, a right frame, a lower frame, and a left frame that are sequentially closed to form a rectangular frame structure, and a window rear panel 20 located on the rear side of the rectangular frame structure. The right frame of the left inner mold 1 is provided with two first positioning holes 5. The right inner mold 2 has the same structure as the left inner mold 1. The left frame of the right inner mold 2 is provided with two second positioning holes. The left frame and lower frame of the left inner mold 1 are... The lower and right sides of the inner mold 2 are provided with multiple evenly distributed breaking grooves 4. The shape of the breaking grooves 4 can be rectangular, square, circular, or irregular. Each first positioning pin can pass through the first positioning hole 5, the inner mold adjusting plate 3, and the second positioning hole in sequence. The two window front panels 7 are respectively fastened to the front side of the rectangular frame structure of the left inner mold 1 and the rectangular frame structure of the right inner mold 2. The height of the inner mold adjusting plate 3 in the vertical direction is less than the height of the two window front panels 7 near the window edge in the vertical direction. The width of the inner mold adjusting plate 3 in the front-back direction is less than the distance between the window front panel 7 and the window rear panel 20. The wall thickness of the inner mold adjusting plate 3 is 1-5mm, and the material of the inner mold adjusting plate 3 is ceramic matrix composite material. The service surface of the inner mold assembly 9 is provided with sewing holes. The diameter of the sewing holes is 1.5-10mm, and the center distance between adjacent sewing holes is 1-15mm.

[0071] The outer mold assembly 18 is arranged outside the inner mold assembly 9, and the use profile of the outer mold assembly 18 is matched with the use profile of the inner mold assembly 9, the outer mold assembly 18 comprises the upper outer mold 11, the lower outer mold 12, and the front cover plate 17, the upper outer mold 11 and the lower outer mold 12 are symmetrical structures, and are buckled into a rectangular frame with the rear cover plate 21 through cooperation of the four connecting tabs 13, the two second positioning pins 23, the four double-headed bolts 14 and the eight nuts 15, the second positioning pin 23 can avoid the relative dislocation between the upper outer mold 11 and the lower outer mold 12, causing the mold to be unable to be closed or not to be closed in place, thereby avoiding defects such as wall thickness exceeding and wrinkles in the final product. The front cover plate 17 is buckled on the front side of the rectangular frame, the front cover plate 17 and the rear cover plate 21 are both windowed structures, the front cover plate 17, the windowed front panel 7, the windowed rear panel 20 and the rear cover plate 21 are arranged in sequence from front to back, and a plurality of reinforcing ribs 16 are arranged on the front side of the front cover plate 17 and the rear side of the rear cover plate 21. The windowed rear panel 20 is provided with a first detection reference hole 6, the windowed front panel 7, the rear cover plate 21 and the front cover plate 17 are provided with a second detection reference hole 22 corresponding to the first detection reference hole 6, and the first detection reference hole 6 and the second detection reference hole 22 are used for re-inspection in the factory. The fastening assembly 8 comprises three reinforcing frames 19 and three wedge-shaped blocks, the three reinforcing frames 19 are sequentially sleeved outside the outer mold assembly 18, and each wedge-shaped block is arranged between the corresponding reinforcing frame 19 and the outer mold assembly 18, and is used for pressing the outer mold assembly 18 in the front-rear direction. In the embodiment, the use profile of the inner mold assembly 9 along the thickness direction is an equal-wall-thickness profile, the wall thickness is 5-10 mm, and the use profile of the outer mold assembly 18 along the thickness direction is an equal-wall-thickness profile, and the wall thickness is 8-12 mm. The materials of the inner mold assembly 9, the outer mold assembly 18 and the fastening assembly 8 are high-temperature materials, and the high-temperature materials can be high-strength fine graphite, high-purity graphite or electrode graphite.

[0072] As shown in Figures 1-7 The preparation method of the ceramic matrix composite hollow hexahedral member in the embodiment is based on the sizing mold of the ceramic matrix composite hollow hexahedral member preform, and comprises the following steps:

[0073] 1) Assemble the inner mold assembly 9

[0074] 1.1) Glue the left inner mold 1 and one of the windowed front panels 7, and glue the right inner mold 2 and the other windowed front panel 7;

[0075] 1.2) The left inner mold 1, the inner mold adjusting plate 3 and the right inner mold 2 are connected and glued by the first positioning pin to form the inner mold assembly 9.

[0076] 2) Sizing of the hollow hexahedral member preform 10

[0077] 2.1) Calculate the amount of fiber cloth required for the hollow hexahedral member preform 10, leave a proper hem allowance, and cut;

[0078] 2.2) Lay up and turn up the cut finished fiber cloth layer by layer on the use surface of the inner mold assembly 9 to obtain a hollow hexahedral component preform intermediate; wherein the lay-up thickness is 1.02-1.1 times the design thickness of the hollow hexahedral component preform, and the straight angle turn-up and the bevel turn-up are alternately used to turn up, which can ensure the misalignment of the cutting port and avoid the cracks, delamination and even fracture due to stress concentration of the cutting port in the subsequent preparation or evaluation process;

[0079] 2.3) Fit the hollow hexahedral component preform intermediate and the rectangular frame formed by buckling the upper outer mold 11 and the lower outer mold 12 and the front cover plate 17 to form a trial fitting mold, remove the rectangular frame and the front cover plate 17 after the trial fitting mold meets the requirements, and then sew and lock the edges to obtain the hollow hexahedral component preform 10; specifically:

[0080] 2.3.1) Trial fit the rectangular frame by buckling the hollow hexahedral component preform intermediate and the upper outer mold 11 and the lower outer mold 12;

[0081] 2.3.2) Detect the fit gap between the hollow hexahedral component preform intermediate and the use surface of the rectangular frame by using a 0.15 mm feeler gauge, if the fit gap is ≥0.15 mm, execute step 2.3.3), if the fit gap is <0.15 mm, execute step 2.3.4);

[0082] 2.3.3) Remove the rectangular frame, add the re-cut fiber cloth at the corresponding position of the use surface of the hollow hexahedral component preform intermediate, then re-fit with the rectangular frame and return to step 2.3.2);

[0083] 2.3.4) Buckle the front cover plate 17 on the front side of the rectangular frame, and then fasten the outer mold assembly 18 by using the reinforcing frame 19 and the wedge-shaped block;

[0084] 2.3.5) Detect the fit gap between the hollow hexahedral component preform intermediate and the use surface of the front cover plate 17 by using a 0.15 mm feeler gauge, if the fit gap is ≥0.15 mm, execute step 2.3.6), if the fit gap is <0.15 mm, remove the rectangular frame and the front cover plate 17, then sew and lock the edges to obtain the hollow hexahedral component preform 10; in this embodiment, the in-situ sewing method is used, the steel needle is perpendicular to the fiber cloth or the mold surface during the sewing process to avoid the internal inclusions caused by the sewing thread ends, the fiber thread ends are left on the non-use surface of the mold, the lock edge requires no needle drop and the needle spacing gap is ≤3 mm, which is used to prevent the delamination of the hollow hexahedral component preform 10 in the subsequent chemical vapor deposition process;

[0085] 2.3.6) dismount the front cover plate 17, add the re-cut fiber cloth on the used profile of the hollow hexahedral component preform intermediate corresponding to the used profile of the front cover plate 17, then re-attach the front cover plate 17 on the front side of the rectangular frame and fasten the outer mold assembly 18 with the reinforcing frame 19 and the wedge blocks, return to step 2.3.5).

[0086] 2.4) close the mold of the rectangular frame formed by the hollow hexahedral component preform 10 and the upper outer mold 11 and the lower outer mold 12, then attach the front cover plate 17 on the front side of the rectangular frame, finally fasten the outer mold assembly 18 with the reinforcing frame 19 and the wedge blocks, then detect the fit clearance between the hollow hexahedral component preform 10 and the upper outer mold 11, the lower outer mold 12 and the front cover plate 17 with a 0.15mm feeler gauge. If the fit clearance is ≥0.15mm, adjust the tightness of the reinforcing frame 19 by adjusting the wedge blocks until the fit clearance is <0.15mm; if the fit clearance is <0.15mm, execute step 3).

[0087] 3) preparation of interface layer and high temperature treatment

[0088] The hollow hexahedral component preform 10 fastened in step 2.4) is subjected to the preparation of interface layer by chemical vapor deposition, then the inner mold adjusting plate 3 is removed, and high temperature treatment is performed; specifically:

[0089] 3.1) place the hollow hexahedral component preform 10 fastened in step 2.4) in a deposition furnace, heat to 500-1000℃ under a furnace pressure of 10-70Pa, heat preservation for 1-3h, then sequentially introduce argon and propylene for deposition until the hollow hexahedral component preform 10 with a pyrolytic carbon interface layer of 100-350nm thickness is obtained, then reduce to room temperature; in this embodiment, the furnace pressure is 60Pa, the temperature is heated to 800℃, heat preservation for 3h, and the thickness of the pyrolytic carbon interface layer is 250nm.

[0090] In other embodiments, step 3.1) can be: place the hollow hexahedral component preform 10 fastened in step 2.4) in a deposition furnace, heat to 650-1000℃ under a furnace pressure of 50-1000Pa, heat preservation for 1-3h, then sequentially introduce argon, hydrogen, ammonia and boron trichloride gas for deposition until the hollow hexahedral component preform 10 with a boron nitride interface layer of 150-750nm thickness is obtained, then reduce to room temperature.

[0091] 3.2) because there is a difference in the thermal expansion coefficients between the shaped mold and the ceramic matrix composite, the thermal expansion coefficient of graphite is: (1-3) x 10 -6 / ℃, and the thermal expansion coefficient of the ceramic matrix composite is: (1-2.5) x 10 -6 / ℃, and the final product is prone to have defects such as pits and wrinkles due to the difference in thermal expansion coefficient during high-temperature treatment. Therefore, the hollow hexahedral component preform 10 after deposition in step 3.1) is removed, the first positioning pin is removed, the inner mold adjusting plate 3 is removed, the left inner mold 1 and the right inner mold 2 are repositioned and connected by using the first positioning pin, and finally high-temperature treatment is performed at a temperature of 1750-2000℃ for 1-5h. In this embodiment, the temperature is 1900℃, and the high-temperature treatment is performed for 2h.

[0092] 4) Preparation of silicon carbide matrix layer;

[0093] The hollow hexahedral component preform 10 after treatment in step 3) is subjected to preparation of a silicon carbide matrix layer by using a chemical vapor deposition method, and demolding is performed during the preparation; specifically:

[0094] 4.1) The hollow hexahedral component preform 10 after treatment in step 3) is placed in a deposition furnace, and the pressure in the furnace is set to 200-5000Pa;

[0095] 4.2) The temperature is raised to 900-1200℃, and after heat preservation for 1-2h, a mixed gas of trichloromethylsilane, hydrogen and argon is introduced, the flow rate ratio of trichloromethylsilane, hydrogen and argon is 1-10:10-20:10-30, deposition is performed for 30-80h, and then heat preservation is continued for 2h, and then the temperature is lowered to room temperature;

[0096] 4.3) After repeating step 4.2) for two to four times, the hollow hexahedral component preform 10 with a silicon carbide matrix layer is taken out, and the inner mold assembly 9 is removed by knocking the inner mold assembly 9;

[0097] 4.4) The hollow hexahedral component preform 10 after removal of the inner mold assembly 9 in step 4.3) is placed in a deposition furnace with a pressure of 200-5000Pa in the furnace, and the process of step 4.2) is repeated for cyclic deposition until the density of the silicon carbide matrix layer is 1.75-1.8g / cm 3 , and the outer mold assembly 18 is removed. In this embodiment, the pressure in the furnace is 3000Pa, the temperature is raised to 900℃, heat preservation is performed for 2h, the flow rate ratio of trichloromethylsilane, hydrogen and argon is 1:10:10, and deposition is performed for 60h.

[0098] 5) Mechanical processing

[0099] The hollow hexahedral component preform 10 after removal of the outer mold assembly 18 in step 4.4) is subjected to mechanical processing, and then the deposition of the silicon carbide matrix layer is continued according to the method of step 4.1) and step 4.2) until the density of the silicon carbide matrix layer is >2.0g / cm 3 , and a ceramic matrix composite hollow hexahedral component is prepared.

[0100] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any change or replacement within the technical scope disclosed by the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A sizing mold for a ceramic matrix composite hollow hexahedral component preform, characterized in that: it comprises an inner mold assembly (9), an outer mold assembly (18), and a fastening assembly (8) for pressing the outer mold assembly (18); the inner mold assembly (9) comprises a left inner mold (1), a right inner mold (2), an inner mold adjusting plate (3), two windowed front panels (7), and at least two first positioning pins; the left inner mold (1) comprises an upper edge frame, a right edge frame, a lower edge frame, and a left edge frame successively closed into a rectangular frame structure, and a windowed back panel (20) arranged on the back side of the rectangular frame structure; the right edge frame of the left inner mold (1) is provided with at least two first positioning holes (5); the right inner mold (2) has the same structure as the left inner mold (1), and the left edge frame of the right inner mold (2) is provided with at least two second positioning holes; the first positioning pins can successively pass through the first positioning holes (5), the inner mold adjusting plate (3), and the second positioning holes; the two windowed front panels (7) are respectively buckled on the front side of the rectangular frame structure of the left inner mold (1) and the rectangular frame structure of the right inner mold (2); the height of the inner mold adjusting plate (3) in the up-down direction is less than the height of the two windowed front panels (7) along the up-down direction, and the width of the inner mold adjusting plate (3) in the front-back direction is less than the distance between the windowed front panel (7) and the windowed back panel (20); a sewing hole is arranged on the use surface of the inner mold assembly (9); the outer mold assembly (18) is arranged outside the inner mold assembly (9), and the use surface of the outer mold assembly (18) is matched with the use surface of the inner mold assembly (9); the outer mold assembly (18) comprises an upper outer mold (11), a lower outer mold (12), and a front cover plate (17); the upper outer mold (11) and the lower outer mold (12) are symmetrical structures and are buckled into a rectangular frame with a back cover plate (21) through a plurality of connecting ear pieces (13); the front cover plate (17) is buckled on the front side of the rectangular frame; the front cover plate (17) and the back cover plate (21) are both windowed structures; the front cover plate (17), the windowed front panel (7), the windowed back panel (20), and the back cover plate (21) are arranged in sequence from front to back.

2. The sizing mold for a ceramic matrix composite hollow hexahedral component preform according to claim 1, characterized in that: the use surface of the inner mold assembly (9) is an equal-wall-thickness surface in the thickness direction, and the wall thickness is 5-10 mm; the use surface of the outer mold assembly (18) is an equal-wall-thickness surface in the thickness direction, and the wall thickness is 8-12 mm; the wall thickness of the inner mold adjusting plate (3) is 1-5 mm.

3. The sizing mold for a ceramic matrix composite hollow hexahedral component preform according to claim 1 or 2, characterized in that: the left edge frame, the lower edge frame of the left inner mold (1), and the lower edge frame, the right edge frame of the right inner mold (2) are provided with a plurality of damage grooves (4); the aperture of the sewing hole is 1.5-10 mm, and the center distance between adjacent sewing holes is 1-15 mm.

4. The sizing mold for a ceramic matrix composite hollow hexahedral component preform according to claim 3, characterized in that: ​ ​ The fastening assembly (8) comprises a plurality of reinforcing frames (19) and wedge blocks; the reinforcing frames (19) are sleeved outside the outer mold assembly (18), and the wedge blocks are arranged between the reinforcing frames (19) and the outer mold assembly (18) and used for pressing the outer mold assembly (18) in the front-rear direction; The first detection reference hole (6) is arranged on the windowed rear panel (20); the windowed front panel (7), the rear cover plate (21) and the front cover plate (17) are provided with the second detection reference hole (22) corresponding to the first detection reference hole (6), and the first detection reference hole (6) and the second detection reference hole (22) are used for re-inspection in a factory.

5. The sizing mold for the ceramic matrix composite hollow hexahedral component preform according to claim 4, characterized in that: A plurality of reinforcing ribs (16) are arranged on the front side of the front cover plate (17) and the rear side of the rear cover plate (21); The shape of the damage groove (4) is rectangular, square, circular or special-shaped; The material of the inner mold adjusting plate (3) is ceramic matrix composite material; The materials of the inner mold assembly (9), the outer mold assembly (18) and the fastening assembly (8) are high-temperature materials; the high-temperature materials are high-strength fine graphite, high-purity graphite or electrode graphite.

6. A method for producing a ceramic matrix composite hollow hexahedron member, based on a shaping mold for a ceramic matrix composite hollow hexahedron member preform according to any one of claims 1 to 5, characterized by, Comprising the following steps: 1) Assembling the inner mold assembly (9) 1.1) Gluing the left inner mold (1) and one of the windowed front panels (7), and gluing the right inner mold (2) and the other windowed front panel (7); 1.2) Positioning and connecting the left inner mold (1), the inner mold adjusting plate (3) and the right inner mold (2) by using the first positioning pin and gluing to form the inner mold assembly (9); 2) Sizing the hollow hexahedral component preform (10) 2.1) Calculating the required amount of fiber cloth for the hollow hexahedral component preform (10) and cutting; 2.2) Laying and turning the cut fiber cloth on the use profile of the inner mold assembly (9) layer by layer to obtain a hollow hexahedral component preform intermediate body; 2.3) Trying the mold by combining the hollow hexahedral component preform intermediate body, the rectangular frame formed by combining the upper outer mold (11) and the lower outer mold (12), and the front cover plate (17); after the mold meets the requirements, removing the rectangular frame and the front cover plate (17), then sewing and locking the edges to obtain the hollow hexahedral component preform (10); 2.4) Combining the hollow hexahedral component preform (10) and the rectangular frame formed by combining the upper outer mold (11) and the lower outer mold (12), then combining the front cover plate (17) on the front side of the rectangular frame, and finally fastening the outer mold assembly (18) by using the fastening assembly (8); 3) Preparing the interface layer and high-temperature treatment Using the chemical vapor deposition method to prepare the interface layer of the hollow hexahedral component preform (10) fastened in step 2.4), then removing the inner mold adjusting plate (3), and then performing high-temperature treatment; 4) Preparing the silicon carbide matrix layer; Using the chemical vapor deposition method to prepare the silicon carbide matrix layer of the hollow hexahedral component preform (10) treated in step 3), and performing demolding during the preparation; 5) Mechanical processing The hollow hexahedral member preform (10) with the prepared silicon carbide matrix layer is subjected to mechanical processing and subsequent treatment to obtain a ceramic matrix composite hollow hexahedral member.

7. The method of producing a ceramic matrix composite hollow hexahedron member according to claim 6, characterized by, Step 4) specifically comprises the following steps: 4.1) placing the hollow hexahedral member preform (10) after the treatment in step 3) in a deposition furnace and setting the pressure in the furnace to 200-5000 Pa; 4.2) heating to 900-1200℃, holding for 1-2 h, then introducing a mixed gas of trichloromethylsilane, hydrogen and argon, the flow ratio of trichloromethylsilane, hydrogen and argon being 1-10:10-20:10-30, depositing for 30-80 h, then continuing to hold for 2 h, and then reducing to room temperature; 4.3) repeating step 4.2) for two to four times, then taking out the hollow hexahedral member preform (10) with the silicon carbide matrix layer, and removing the inner mold assembly (9) by knocking the inner mold assembly (9); 4.4) placing the hollow hexahedral member preform (10) with the removed inner mold assembly (9) in step 4.3) in a deposition furnace with a pressure of 200-5000 Pa, and performing cyclic deposition according to the process of step 4.2) until the density of the silicon carbide matrix layer is 1.75-1.8 g / cm3, and then removing the outer mold assembly (18).

8. The method of claim 7, wherein the ceramic matrix composite hollow hexahedron member is prepared by the steps of: preparing a ceramic matrix composite hollow hexahedron member; and coating the ceramic matrix composite hollow hexahedron member with a coating layer. Step 2.3) specifically comprises the following steps: 2.3.1) fitting the hollow hexahedral member preform intermediate and the rectangular frame formed by fitting the upper outer mold (11) and the lower outer mold (12); 2.3.2) using a 0.15 mm plug gauge to detect the fitting gap between the hollow hexahedral member preform intermediate and the use profile of the rectangular frame, if the fitting gap is ≥0.15 mm, step 2.3.3) is performed, if the fitting gap is <0.15 mm, step 2.3.4) is performed; 2.3.3) disassembling the rectangular frame, adding newly cut fiber cloth at the corresponding position of the use profile of the hollow hexahedral member preform intermediate, then refitting with the rectangular frame and returning to step 2.3.2); 2.3.4) fitting the front cover plate (17) on the front side of the rectangular frame, and then fastening the outer mold assembly (18) using the fastening assembly (8); 2.3.5) using a 0.15 mm plug gauge to detect the fitting gap between the hollow hexahedral member preform intermediate and the use profile of the front cover plate (17), if the fitting gap is ≥0.15 mm, step 2.3.6) is performed, if the fitting gap is <0.15 mm, disassembling the rectangular frame and the front cover plate (17), then sewing and locking to obtain the hollow hexahedral member preform (10); 2.3.6) disassembling the front cover plate (17), adding newly cut fiber cloth on the use profile of the hollow hexahedral member preform intermediate corresponding to the use profile of the front cover plate (17), then refitting the front cover plate (17) on the front side of the rectangular frame and fastening the outer mold assembly (18) using the fastening assembly (8), and returning to step 2.3.5).

9. The method of producing a ceramic matrix composite hollow hexahedron member according to claim 8, characterized by, Step 3) specifically comprises the following steps: 3.1) Put the hollow hexahedron component preform (10) fastened in step 2.4) into a deposition furnace, and heat to 650-1000℃ under the pressure of 50-1000Pa in the furnace, and then deposit argon, hydrogen, ammonia and boron trichloride in sequence under the condition of 1-3h of heat preservation, until the hollow hexahedron component preform (10) with the interface layer of boron nitride of 150-750nm in thickness is obtained, and then reduce to room temperature; Or, put the hollow hexahedron component preform (10) fastened in step 2.4) into a deposition furnace, and heat to 500-1000℃ under the pressure of 10-70Pa in the furnace, and then deposit argon and propylene in sequence under the condition of 1-3h of heat preservation, until the hollow hexahedron component preform (10) with the interface layer of pyrolytic carbon of 100-350nm in thickness is obtained, and then reduce to room temperature; 3.2) Take out the hollow hexahedron component preform (10) deposited in step 3.1), remove the first positioning pin, then remove the inner mold adjusting plate (3), and then reposition and connect the left inner mold (1) and the right inner mold (2) by using the first positioning pin, and finally perform high temperature treatment at the temperature of 1750-2000℃ for 1h-5h.

10. The method of producing a ceramic matrix composite hollow hexahedron member according to claim 9, wherein Step 5) is specifically: Mechanically process the hollow hexahedron component preform (10) from which the outer mold assembly (18) is removed in step 4.4), and then continue to deposit the silicon carbide substrate layer according to the method of step 4.1) and step 4.2), until the density of the silicon carbide substrate layer is >2.0g / cm3, to obtain the ceramic matrix composite hollow hexahedron component.

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