A mold preparation method for ceramic matrix composite preforms

Abstract

The present application relates to a kind of mould preparation methods for ceramic matrix composite preform, to solve the technical problems of the size of existing ceramic matrix composite preform mould, connection mode is complex, ceramic matrix composite component deformation even scrap caused by difficult demoulding.The method comprises:1, design mould;2, processing mould;3, ceramic matrix composite preform shaping is carried out on inner mould;4, sub outer mould carries out test moulding, adjacent outer mould assembly surface has 1-3mm reserved gap and the gap of outer mould and ceramic matrix composite preform is less than 0.15mm, then test moulding is qualified;5, ceramic matrix composite preform is sutured with inner mould;6, outer mould assembly surface pretreatment;7, high temperature adhesive is brushed and pre-assembled, until the contour tolerance of external shape is ±0.05mm;8, high temperature adhesive solidification, obtain the mould for ceramic matrix composite preform.

Description

TECHNICAL FIELD

[0001] The present application relates to a mold preparation method of a composite material preform, in particular to a mold preparation method for a ceramic matrix composite material preform. BACKGROUND

[0002] The ceramic matrix composite material is widely used in the field of aerospace due to its excellent performance such as high strength, high rigidity, good fatigue resistance and designability of material layer. At present, the preparation processes of CMC-SiC ceramic composite material mainly include slurry impregnation-thermal pressure sintering method, direct oxidation deposition method (Direct Oxidation), chemical vapor infiltration method (Chemical Vapor Infiltration, CVI), precursor polymer decomposition (Polymer Impregnation Pyrolysis, PIP), reactive melt infiltration method (Reactive Melt Infiltration, RMI) and directional solidification method. Different preparation methods have a common point that a mold is needed to protect and fix the preform during the preparation process. Therefore, the mold is an indispensable equipment in the preparation process of the ceramic matrix composite material, and plays an important role in the preparation of components with various complex structures and different sizes. The structure and connection mode of the mold have important influence on its performance. For the mold design used in the shaping process of the ceramic matrix composite component, the specific mold design principles need to be formulated according to different types of components. However, the following points need to be considered during the mold design process: the accessibility of complex surface processing, the uniformity of component molding, the protection of component during demolding and the density uniformity during the subsequent chemical vapor deposition process.

[0003] Under the above requirements, the existing mold mainly adopts a combined form mold structure, the mold is designed by splitting, and the split molds are connected by graphite bolts and nuts. This connection method is too complex, the size of the mold is increased due to the need for connecting pieces, which leads to an increase in the cycle and time cost of mold processing, the wall thickness of the mold connecting piece connection position is relatively thick, which affects the uniformity of the subsequent hot forming preparation process during the component preparation process, thereby affecting the final mechanical properties of the component. Some structure molds are difficult to demold, are not easy to operate and may cause connection failure, thereby causing the component to deform or even be scrapped during the subsequent preparation process, and the mold is easily damaged, thereby increasing the cost of mold manufacturing and the cycle of component preparation. SUMMARY

[0004] The application aims to solve the technical problems of ceramic matrix composite component deformation or even scrapping caused by the large size of the existing ceramic matrix composite preform mold, the complex connection mode and the difficulty in demolding, and provides a mold preparation method for a ceramic matrix composite preform.

[0005] The technical scheme provided by the application is as follows:

[0006] The mold preparation method for the ceramic matrix composite preform has the speciality that it comprises the following steps:

[0007] S1, a mold is designed according to the shape of the ceramic matrix composite preform, and the mold comprises an inner mold, an outer mold and fasteners;

[0008] The outer mold comprises at least two sub-outer molds; the sub-outer molds have outer mold assembly surfaces for assembly, the outer mold assembly surfaces of the adjacent two sub-outer molds are connected, and the at least two sub-outer molds are assembled into an outer mold which is adapted to the ceramic matrix composite preform; the outer mold assembly surfaces are provided with outer mold positioning holes;

[0009] S2, the inner mold, each sub-outer mold and the fasteners are processed according to the mold designed in step S1, and the materials of the inner mold, the sub-outer molds and the fasteners are all graphite;

[0010] S3, carbon fiber cloth is laid on the outer side of the inner mold to shape the ceramic matrix composite preform;

[0011] S4, each sub-outer mold is sleeved on the outer side of the ceramic matrix composite preform and fixed by the fasteners to perform a trial assembly, so that the adjacent outer mold assembly surfaces have a reserved gap of 1-3 mm, and the gap between the outer mold and the ceramic matrix composite preform is measured; if the gap is less than 0.15 mm, the trial assembly is qualified; if the gap is greater than or equal to 0.15 mm, the carbon fiber cloth is laid on the outer side of the ceramic matrix composite preform until the trial assembly is qualified;

[0012] S5, the fasteners and the outer mold are removed, the ceramic matrix composite preform is sutured and fixed with the inner mold, and then the outer mold is sleeved on the outer side of the ceramic matrix composite preform;

[0013] S6, the positioning pins are positioned and assembled to the outer mold sleeved on the outer side of the ceramic matrix composite preform through the outer mold positioning holes on the outer mold assembly surfaces, and the adjacent outer mold assembly surfaces have a reserved gap of 1-3 mm; the outer mold assembly surfaces are treated clean and kept dry;

[0014] S7, the high-temperature adhesive is uniformly coated on the outer mold assembly surfaces, after one coating of the high-temperature adhesive on the outer mold assembly surfaces, the hot air gun is used to blow and coat the surface for not less than 50 s at 100-150 DEG C;

[0015] S8, repeat step S7, and pre-assemble the sub-outer mold. After pre-assembly, measure the overall size of the mold using a three-coordinate measuring instrument until the contour tolerance is ±0.05mm. Complete the assembly of the outer mold, and set the fasteners on the outside of the outer mold to complete the mold assembly;

[0016] S9, after the mold assembly of step S8 is completed using fasteners, it is placed at room temperature and pressure for at least 24 hours, or dried at 200-600°C for 3-20 hours, to obtain a mold for a ceramic matrix composite preform.

[0017] Further, in step S7, the maximum temperature of the effective working temperature range of the high-temperature adhesive is greater than the temperature at which the corresponding ceramic matrix composite preform is prepared by deposition.

[0018] Further, in step S1, the inner mold includes at least two sub-inner molds, and the sub-inner molds have inner mold assembly surfaces for assembly, and the inner mold assembly surfaces are provided with inner mold positioning holes;

[0019] In step S2, the inner mold is machined, specifically each sub-inner mold is machined;

[0020] In step S3, the ceramic matrix composite preform is shaped by laying carbon fiber cloth on the inner mold, specifically:

[0021] S3.1, the positioning pin is positioned and assembled on the inner mold through the inner mold positioning hole on the inner mold assembly surface, and the inner mold assembly surfaces have a reserved gap of 1-3mm; the inner mold assembly surface is treated clean and kept dry;

[0022] S3.2, the high-temperature adhesive is uniformly coated on the inner mold assembly surface, and after one coating of the high-temperature adhesive on the inner mold assembly surface, the hot air gun is adjusted to 100-150°C to blow the coating surface for not less than 50s;

[0023] S3.3, repeat step S3.2, and pre-assemble the sub-inner mold. After pre-assembly, detect the overall size of the mold using a three-coordinate measuring instrument until the contour tolerance is ±0.05mm, and complete the assembly of the inner mold;

[0024] S3.4, lay carbon fiber cloth on the inner mold assembled in step S3.3 to shape the ceramic matrix composite preform, and the thickness of the laid carbon fiber cloth is 1.02-1.1 times the designed thickness of the ceramic matrix composite preform.

[0025] Further, in step S3.2, the selection of the high-temperature adhesive: if the mold corresponds to a ceramic matrix composite preform that is subsequently prepared by deposition process, the high-temperature adhesive used for the assembly of the outer mold has a higher effective working temperature than the high-temperature adhesive used for the assembly of the inner mold.

[0026] If the outer mold is demolded first and then the inner mold is demolded in the subsequent deposition preparation process of the ceramic matrix composite preform corresponding to the mold, the effective working temperature of the high-temperature adhesive used in the assembly of the outer mold is lower than that of the high-temperature adhesive used in the assembly of the inner mold.

[0027] Further, in step S7, the high-temperature adhesive includes a first high-temperature adhesive with an effective working temperature range of room temperature-1200℃, a second high-temperature adhesive with an effective working temperature range of room temperature-1400℃, a third high-temperature adhesive with an effective working temperature range of room temperature-1600℃, or a fourth high-temperature adhesive with an effective working temperature range of room temperature-1800℃.

[0028] Further, in step S7, the first high-temperature adhesive includes, by weight fraction: PVA polyvinyl alcohol 2-8 parts, borax 1-3 parts, aluminum dihydrogen phosphate 2-6 parts, acrylamide 1-2 parts, N-N-methylene bisacrylamide 1-2 parts, graphite powder 5-10 parts, SiC powder 70-78 parts, and water 10-20 parts.

[0029] The second high-temperature adhesive includes, by weight fraction: PVA polyvinyl alcohol 4-15 parts, borax 1-5 parts, aluminum dihydrogen phosphate 2-10 parts, acrylamide 2-5 parts, N-N-methylene bisacrylamide 2-5 parts, graphite powder 5-10 parts, SiC powder 70-85 parts, and water 10-20 parts.

[0030] The third high-temperature adhesive includes, by weight fraction: PVA polyvinyl alcohol 2-8 parts, borax 1-5 parts, aluminum dihydrogen phosphate 2-10 parts, acrylamide 2-5 parts, N-N-methylene bisacrylamide 2-5 parts, zirconium carbide 1-2 parts, graphite powder 5-10 parts, SiC powder 70-85 parts, and water 10-20 parts.

[0031] The fourth high-temperature adhesive includes, by weight fraction: PVA polyvinyl alcohol 4-15 parts, borax 1-5 parts, aluminum dihydrogen phosphate 2-15 parts, acrylamide 2-5 parts, N-N-methylene bisacrylamide 2-5 parts, zirconium carbide 2-6 parts, graphite powder 5-10 parts, SiC powder 70-85 parts, and water 10-20 parts.

[0032] Further, in step S2, the graphite is high-strength fine graphite, high-purity graphite, or electrode graphite.

[0033] Further, in step S1, the shape of the ceramic matrix composite preform is a solid of revolution, a box, a curved surface, a blade, a U-shaped piece, an L-shaped piece, a Z-shaped piece, a W-shaped piece, a special-shaped piece, or a flat plate.

[0034] Further, the step S6, the outer mold assembly surface is treated clean and keep dry specifically is: after using handheld air gun to blow clean assembly surface, then using ethanol soaked dustless cloth to wipe, and under room temperature room pressure, standing for 5-10 min, make it dry fully.

[0035] The beneficial effects of the present application are:

[0036] 1、The mold preparation method provided by the present application adopts the method of connecting by high-temperature adhesive, which can effectively reduce the area required by the bolt and nut connection method, improve the connection quality, reduce the weight of the overall mold device, and reduce the space occupied during the preparation process of the composite component, thereby improving the preparation efficiency.

[0037] 2、The present application can select appropriate high-temperature adhesive according to the preparation process of the mold, so that the mold can be safely and conveniently detached without damaging the component and the mold, effectively improving the qualified rate of the component and the reuse rate of the mold, and reducing the time cost and economic cost.

[0038] 3、The preparation process of the present application is simple and convenient to operate, and since the mold is of split structure, the size of the mold is reduced, the processing cycle of the mold is shortened, the economic cost is reduced, and the transportation efficiency and safety are improved.

[0039] 4、The present application connects the mold by selecting different high-temperature adhesives through different process routes, and under the premise of avoiding deformation of the component, the inner mold and the outer mold can be separated at a specific temperature working interval through the failure of the high-temperature adhesive, thereby improving the deposition uniformity of the component and the final mechanical properties of the material.

[0040] 5、The method of connecting by high-temperature adhesive can effectively reduce the area required by the bolt and nut connection method, ensure the uniformity of the overall wall thickness of the mold, improve the deposition uniformity, and ensure the reliability of the prepared component.

[0041] 6、The present application connects the mold by high-temperature adhesive during the preparation of the composite material, avoids the occurrence of component deformation and scrap, mold damage, etc. due to the failure of the mold connecting piece, and ensures the stability of the size and shape during the preparation of the component. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 It is a box body component preform embodiment schematic diagram for the mold preparation method for ceramic matrix composite preform of the present application;

[0043] Figure 2 It is a mold design structure schematic diagram (without showing fasteners) in the embodiment of the present application;

[0044] Figure 3 It is an inner mold structure schematic diagram in the embodiment of the present application;

[0045] Figure 4 Figure 1 is a schematic diagram of the outer mold structure in the embodiment of the present application;

[0046] Figure 5 Figure 2 is a schematic diagram of the assembly surface structure in the embodiment of the present application; Figure 1 ;

[0047] Figure 6 Figure 3 is a schematic diagram of the assembly surface structure in the embodiment of the present application; Figure 2 ;

[0048] Figure 7 Figure 4 is a schematic diagram of the mold and preform assembly structure in the embodiment of the present application.

[0049] Reference signs:

[0050] 1 - ceramic matrix composite preform, 2 - inner mold, 3 - sub-outer mold, 4 - outer mold assembly surface, 5 - detection reference hole, 6 - limiting groove, 9 - outer mold positioning hole, 10 - fastener. DETAILED DESCRIPTION

[0051] In order to make the above objectives, features and advantages of the present application more apparent, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present application.

[0052] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced without the specific details that are set forth in the following description, and it is understood that persons having ordinary skill in the art can make and use other implementations of the present application according to the following description, without departing from the scope of the present application. Accordingly, the present application is not intended to be limited by the embodiments described herein.

[0053] The term "embodiment" as used herein means a specific feature, structure or characteristic that can be included in at least one implementation of the present application. The term "in other embodiments" does not mean the same embodiment, nor does it mean an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0054] The present application is described in detail with reference to the accompanying drawings. In the detailed description of the embodiments of the present application, the cross-sectional view of the device structure is partially enlarged without the general proportion for the convenience of description, and the schematic diagram is only an example, which should not limit the scope of protection of the present application. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in the actual manufacture.

[0055] The embodiment provides a mold preparation method for a ceramic matrix composite preform, taking a box type preform as an example, and the method comprises the following steps:

[0056] S1, a mold is designed according to the shape of the ceramic matrix composite preform 1, referring to FIG. 1, the mold comprises an inner mold 2, an outer mold and a fastener 10, the inner mold 2 and the outer mold are designed with equal thickness; the inner mold 2 is a one-piece structure, and the outer mold comprises two sub-outer molds 3; the sub-outer mold 3 has an outer mold assembly surface 4 for assembly, so as to be assembled into an outer mold matched with the ceramic matrix composite preform 1; the outer mold assembly surface 4 is provided with an outer mold positioning hole 9. Figures 1-6

[0057] S2, the inner mold 2, each sub-outer mold 3 and the fastener 10 are processed according to the mold designed in step S1, the materials of the inner mold 2, the sub-outer mold 3 and the fastener 10 are all graphite, and the graphite adopts high-strength fine graphite, high-purity graphite or electrode graphite.

[0058] The inner mold 2 and the sub-outer mold 3 are provided with detection reference holes 5 for detecting the processed inner mold 2 and sub-outer mold 3, and confirming whether they meet the use requirements.

[0059] S3, the ceramic matrix composite preform 1 is shaped by laying carbon fiber cloth on the inner mold 2.

[0060] S4, as shown in FIG. 4, each sub-outer mold 3 is sleeved on the outer side of the ceramic matrix composite preform 1, and is fixed by the fastener 10 to perform a trial mold, so that the adjacent outer mold assembly surfaces 4 have a reserved gap of 1-3 mm, and at the same time, the gap between the outer mold and the ceramic matrix composite preform 1 is measured by using a 0.15 mm feeler gauge, if the gap is <0.15 mm, the trial mold is qualified; if the gap is ≥0.15 mm, the carbon fiber cloth is continuously laid on the ceramic matrix composite preform 1 until the trial mold is qualified. Figure 7

[0061] S5, the fastener 10 and the outer mold are removed, the ceramic matrix composite preform 1 is sewn with the inner mold 2, the steel needle is perpendicular to the fiber cloth or the surface of the mold during the sewing process, the connecting head of the sewing is left on the non-use surface of the mold, and then the outer mold 3 is sleeved on the outer side of the ceramic matrix composite preform 1.

[0062] S6, the positioning pin is positioned and assembled to the outer mold sleeved on the ceramic matrix composite preform 1 through the outer mold positioning hole 9 on the outer mold assembly surface 4, and the outer mold assembly surfaces 4 have a reserved gap of 1-3 mm; the outer mold assembly surfaces 4 are treated clean and kept dry, specifically, the surface of the assembly surface is cleaned by using a hand-held air gun, then the surface is wiped by using an ethanol soaked dust-free cloth, and the outer mold assembly surfaces 4 are placed for 5-10 min under room temperature and room pressure, so that the outer mold assembly surfaces 4 are fully dried.

[0063] ​​S7, the high-temperature adhesive is uniformly coated on the outer mold assembly surface 4, and the effective working temperature range of the high-temperature adhesive is room temperature-1800 DEG C; specifically, the high-temperature adhesive includes a first high-temperature adhesive with an effective working temperature range of room temperature-1200 DEG C, a second high-temperature adhesive with an effective working temperature range of room temperature-1400 DEG C, a third high-temperature adhesive with an effective working temperature range of room temperature-1600 DEG C, and a fourth high-temperature adhesive with an effective working temperature range of room temperature-1800 DEG C, wherein the first high-temperature adhesive includes, by weight fraction, PVA polyvinyl alcohol 2-8 parts, borax 1-3 parts, aluminum dihydrogen phosphate 2-6 parts, acrylamide 1-2 parts, N-N-methylene bisacrylamide 1-2 parts, graphite powder 5-10 parts, SiC powder 70-78 parts, and water 10-20 parts; the second high-temperature adhesive includes, by weight fraction, PVA polyvinyl alcohol 4-15 parts, borax 1-5 parts, aluminum dihydrogen phosphate 2-10 parts, acrylamide 2-5 parts, N-N-methylene bisacrylamide 2-5 parts, graphite powder 5-10 parts, SiC powder 70-85 parts, and water 10-20 parts; the third high-temperature adhesive includes, by weight fraction, PVA polyvinyl alcohol 2-8 parts, borax 1-5 parts, aluminum dihydrogen phosphate 2-10 parts, acrylamide 2-5 parts, N-N-methylene bisacrylamide 2-5 parts, zirconium carbide 1-2 parts, graphite powder 5-10 parts, SiC powder 70-85 parts, and water 10-20 parts; and the fourth high-temperature adhesive includes, by weight fraction, PVA polyvinyl alcohol 4-15 parts, borax 1-5 parts, aluminum dihydrogen phosphate 2-15 parts, acrylamide 2-5 parts, N-N-methylene bisacrylamide 2-5 parts, zirconium carbide 2-6 parts, graphite powder 5-10 parts, SiC powder 70-85 parts, and water 10-20 parts.

[0064] The high-temperature adhesive will debond at a temperature higher than the effective working temperature range, because graphite powder begins to oxidize at 600 DEG C in an air atmosphere, and the oxidation reaches a peak at about 800 DEG C. When the continuous oxidation phenomenon occurs, the adhesive strength of the adhesive decreases, thereby achieving debonding. In this embodiment, the highest temperature of the effective working temperature range of the high-temperature adhesive is greater than the temperature at which the ceramic matrix composite preform 1 is prepared by deposition. After one coating of the high-temperature adhesive on the outer mold assembly surface 4, a hot air gun is used to blow the coated surface at 100-150 DEG C for not less than 50 s until the connecting surface has no sticky phenomenon. During the coating process, the principle of from top to bottom, from left to right, from inside to outside, from difficult to easy, and vertical and horizontal interlacing should be followed, and there should be no dripping phenomenon and no visible solution accumulation.

[0065] S8, repeat step S7, and pre-assemble the sub-outer mold 3, ensure that the upper and lower mold surfaces and the end surface interfaces of each mold are flush, the limiting groove 6 on the inner mold 2 is flush with the upper surface of the preform, and there is no obvious step or gap; after pre-assembly, measure the overall size of the mold using a three-coordinate measuring instrument until the contour tolerance is ±0.05mm, the outer mold is completed, and the fastener 10 is then arranged outside the outer mold 3 to complete the mold closing.

[0066] S9, after the mold of step S8 is fixed with the fastener 10, it is placed at room temperature and pressure for at least 24 hours, or dried at 200-600°C for 3-20 hours, until the high-temperature adhesive is cured, obtaining the mold for the ceramic matrix composite preform 1; subsequent processing can be performed. It can be understood that the two high-temperature adhesive curing methods can be flexibly selected according to the time requirements.

[0067] In other embodiments, in step S1, the inner mold 2 can include a plurality of sub-inner molds, and the sub-inner molds have inner mold assembly surfaces for assembly, and the inner mold assembly surfaces are provided with inner mold positioning holes; in step S2, the inner mold 2 is processed by processing each sub-inner mold; in step S3, the ceramic matrix composite preform 1 is shaped by laying carbon fiber cloth on the inner mold 2, specifically:

[0068] S3.1, the positioning pin is positioned and assembled on the inner mold 2 through the inner mold positioning hole on the inner mold assembly surface, and the inner mold assembly surfaces have a reserved gap of 1-3mm; the inner mold assembly surface is treated clean and kept dry.

[0069] S3.2, the high-temperature adhesive is uniformly coated on the inner mold assembly surface, and after one coating of the high-temperature adhesive on the inner mold assembly surface, the hot air gun is adjusted to 100-150°C to blow the coating surface for not less than 50s; here, the selection of the high-temperature adhesive needs to consider the working environment temperature of the subsequent processing of the preform, if the mold corresponds to the ceramic matrix composite preform 1, and the subsequent deposition preparation process is first demolded from the inner mold 2 and then demolded from the outer mold, the effective working temperature of the high-temperature adhesive used for the outer mold assembly is higher than that of the high-temperature adhesive used for the inner mold assembly; if the mold corresponds to the ceramic matrix composite preform 1, and the subsequent deposition preparation process is first demolded from the outer mold and then demolded from the inner mold 2, the effective working temperature of the high-temperature adhesive used for the outer mold assembly is lower than that of the high-temperature adhesive used for the inner mold assembly.

[0070] S3.3, repeat step S3.2, and pre-assemble the sub-inner mold 2, and after pre-assembly, detect the overall size of the mold using a three-coordinate measuring instrument until the contour tolerance is ±0.05mm, and the inner mold 2 is completed;

[0071] S3.4 Laying carbon fiber cloth on the assembled inner mold 2 to shape the ceramic matrix composite preform 1, the first step of the shaping operation is the calculation and cutting work of the fiber cloth, the amount of fiber cloth required for the maximum outer dimension of the box-shaped part is calculated, and an appropriate hem allowance is left, the reserved amount is not less than 10mm from the end face distance of the preform to the inner and outer mold; then the fiber cloth is cut according to the calculated size; the fiber cloth after cutting is folded layer by layer on the inner mold assembly using the profile, and the component is layered and folded layer by layer, the folding method of the box-shaped part mainly includes two kinds, which are right angle folding and bevel folding, the thickness of the laid carbon fiber cloth is 1.02-1.1 times the designed thickness of the ceramic matrix composite preform 1.

[0072] The above embodiment is based on the ceramic matrix composite preform 1 of the box body, the mold preparation method provided by the application is also applicable to a rotary body, a box body, a curved surface part, a blade part, a U-shaped part, an L-shaped part, a Z-shaped part, a W-shaped part, a special-shaped part or a flat plate part; the mold preparation method can avoid the need for additional connection structure design (for example, the need to design structures such as flanges and connection flanges for connection) in the existing mechanical connection, reduce the weight and volume of the mold, at the same time, only the mold and the ceramic matrix composite preform 1 integral component need to be heated to above the effective working temperature of the high-temperature adhesive used during demolding, which can automatically demold, avoiding the damage to the mold and the preform during demolding in the mechanical connection mode, reducing the cost, being convenient to operate, and effectively changing the uniformity in the subsequent deposition preparation process of the component, improving the mechanical properties of the component.

Claims

1. A mold preparation method for a ceramic matrix composite preform, characterized by, The method comprises the following steps: S1, a mold is designed according to the shape of the ceramic matrix composite preform (1), the mold comprises an inner mold (2), an outer mold and a fastener (10); the inner mold (2) comprises at least two sub-inner molds, and the sub-inner molds have inner mold assembly surfaces for assembly, and inner mold positioning holes are arranged on the inner mold assembly surfaces; the outer mold comprises at least two sub-outer molds (3); the sub-outer molds (3) have outer mold assembly surfaces (4) for assembly, the outer mold assembly surfaces (4) of adjacent two sub-outer molds (3) are connected, and the at least two sub-outer molds (3) are assembled into an outer mold matched with the ceramic matrix composite preform (1); outer mold positioning holes (9) are arranged on the outer mold assembly surfaces (4); S2, the inner mold (2), each sub-outer mold (3) and the fastener (10) are processed according to the mold designed in step S1, and the materials of the inner mold (2), the sub-outer molds (3) and the fastener (10) are all graphite; the inner mold (2) is processed, specifically, each sub-inner mold is processed; S3, carbon fiber cloth is laid on the outer side of the inner mold (2) to shape the ceramic matrix composite preform (1); specifically, S3.1, a positioning pin is positioned and assembled to the inner mold (2) through the inner mold positioning holes on the inner mold assembly surfaces, and a reserved gap of 1-3 mm is arranged between the inner mold assembly surfaces; the inner mold assembly surfaces are treated and kept dry; S3.2, high-temperature adhesive is uniformly coated on the inner mold assembly surfaces, after one coating of the high-temperature adhesive on the inner mold assembly surfaces, a hot air gun is used to blow and coat the surface at 100-150 DEG C for not less than 50 s; S4, each sub-outer mold (3) is sleeved on the outer side of the ceramic matrix composite preform (1), and is fixed by the fastener (10) to perform trial assembly, so that a reserved gap of 1-3 mm is arranged between adjacent outer mold assembly surfaces (4), and the gap between the outer mold and the ceramic matrix composite preform (1) is measured, if the gap is less than 0.15 mm, the trial assembly is qualified; if the gap is greater than or equal to 0.15 mm, carbon fiber cloth is laid on the outer side of the ceramic matrix composite preform (1) until the trial assembly is qualified; S5, the fastener (10) and the outer mold are removed, the ceramic matrix composite preform (1) is sutured and fixed with the inner mold (2), and then the outer mold is sleeved on the outer side of the ceramic matrix composite preform (1); S6, a positioning pin is positioned and assembled to the outer mold sleeved on the outer side of the ceramic matrix composite preform (1) through the outer mold positioning holes (9) on the outer mold assembly surfaces (4), and a reserved gap of 1-3 mm is arranged between the outer mold assembly surfaces (4); the outer mold assembly surfaces (4) are treated and kept dry; S7, high-temperature adhesive is uniformly coated on the outer mold assembly surfaces (4), after one coating of the high-temperature adhesive on the outer mold assembly surfaces (4), a hot air gun is used to blow and coat the surface at 100-150 DEG C for not less than 50 s; S8, step S7 is repeated, and pre-assembly of the sub-outer molds (3) is performed, after the pre-assembly, a three-coordinate measuring instrument is used to measure the overall size of the mold, until the contour tolerance of the outer shape is ±0.05 mm, the outer mold is completed, and the fastener (10) is arranged on the outer side of the outer mold (3) to complete the assembly of the mold. S9, after the mold of step S8 is fixed by fasteners (10), it is placed for at least 24 hours under normal temperature and pressure, or baked for 3-20 hours at 200-600℃, to obtain a mold for ceramic matrix composite preform (1); The selection of the high-temperature adhesive: if the inner mold (2) is demolded first and then the outer mold is demolded in the subsequent deposition preparation process of the ceramic matrix composite preform (1) corresponding to the mold, the effective working temperature of the high-temperature adhesive used for assembling the outer mold is higher than that of the high-temperature adhesive used for assembling the inner mold; If the outer mold is demolded first and then the inner mold (2) is demolded in the subsequent deposition preparation process of the ceramic matrix composite preform (1) corresponding to the mold, the effective working temperature of the high-temperature adhesive used for assembling the outer mold is lower than that of the high-temperature adhesive used for assembling the inner mold.

2. The mold preparation method for the ceramic matrix composite preform according to claim 1, characterized in that: In step S7, the highest temperature of the effective working temperature range of the high-temperature adhesive is higher than the temperature at which the ceramic matrix composite preform (1) is prepared by deposition.

3. The mold preparation method for the ceramic matrix composite preform according to claim 2, characterized in that: After step S3.2 of step S3, it further includes: S3.3, repeating step S3.2, pre-assembling the inner mold (2), and detecting the overall size of the mold by using a three-coordinate measuring instrument after pre-assembly until the contour tolerance is ±0.05mm, and the inner mold (2) is completed; S3.4, laying carbon fiber cloth on the inner mold (2) completed in step S3.3 to shape the ceramic matrix composite preform (1), and the thickness of the laid carbon fiber cloth is 1.02-1.1 times the designed thickness of the ceramic matrix composite preform (1).

4. The mold preparation method for the ceramic matrix composite preform according to any one of claims 1-3, characterized in that: In step S7, the high-temperature adhesive includes a first high-temperature adhesive with an effective working temperature range of room temperature-1200℃, a second high-temperature adhesive with an effective working temperature range of room temperature-1400℃, a third high-temperature adhesive with an effective working temperature range of room temperature-1600℃, or a fourth high-temperature adhesive with an effective working temperature range of room temperature-1800℃.

5. The mold preparation method for the ceramic matrix composite preform according to claim 4, characterized in that: In step S7, the first high-temperature adhesive includes, by weight fraction, PVA polyvinyl alcohol 2-8 parts, borax 1-3 parts, aluminum dihydrogen phosphate 2-6 parts, acrylamide 1-2 parts, N-N-methylene bisacrylamide 1-2 parts, graphite powder 5-10 parts, SiC powder 70-78 parts, and water 10-20 parts; The second high-temperature adhesive includes, by weight fraction, PVA polyvinyl alcohol 4-15 parts, borax 1-5 parts, aluminum dihydrogen phosphate 2-10 parts, acrylamide 2-5 parts, N-N-methylene bisacrylamide 2-5 parts, graphite powder 5-10 parts, SiC powder 70-85 parts, and water 10-20 parts; The third high-temperature adhesive comprises, by weight fraction, PVA polyvinyl alcohol 2-8 parts, borax 1-5 parts, aluminum dihydrogen phosphate 2-10 parts, acrylamide 2-5 parts, N-N-methylene bisacrylamide 2-5 parts, zirconium carbide 1-2 parts, graphite powder 5-10 parts, SiC powder 70-85 parts, and water 10-20 parts. The fourth high-temperature adhesive comprises, by weight fraction, PVA polyvinyl alcohol 4-15 parts, borax 1-5 parts, aluminum dihydrogen phosphate 2-15 parts, acrylamide 2-5 parts, N-N-methylene bisacrylamide 2-5 parts, zirconium carbide 2-6 parts, graphite powder 5-10 parts, SiC powder 70-85 parts, and water 10-20 parts.

6. The mold manufacturing method for the ceramic matrix composite preform according to claim 5, characterized in that: In step S2, the graphite is high-strength fine graphite, high-purity graphite or electrode graphite.

7. The mold manufacturing method for the ceramic matrix composite preform according to claim 6, characterized in that: In step S1, the shape of the ceramic matrix composite preform (1) is a rotation body, a box body, a curved surface piece, a blade piece, a U-shaped piece, an L-shaped piece, a Z-shaped piece, a W-shaped piece, a special-shaped piece or a flat plate piece.

8. The mold manufacturing method for the ceramic matrix composite preform according to claim 7, characterized in that: In step S6, the outer mold assembly surface (4) is treated and kept dry, specifically: after the surface of the assembly surface is cleaned by using a handheld air gun, the surface is wiped by using ethanol-drenched non-dusting cloth, and the assembly surface is kept dry at room temperature for 5-10 minutes.

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