Forming method and forming device for high-temperature-resistant hollow leading edge structure

Abstract

The invention provides a forming method and a forming device for a high-temperature-resistant hollow leading edge structure. According to the forming method, a V-shaped structure prefabricated body, an H-shaped structure prefabricated body, a flat plate structure prefabricated body, a corresponding V-shaped structure forming mold, a corresponding H-shaped structure forming mold and a corresponding flat plate structure forming mold are assembled to form a plurality of combined molds; the method comprises the following steps: firstly, preparing a plurality of combined molds, then performing densification treatment on the plurality of combined molds by adopting a precursor impregnation cracking process, then removing the molds, processing, preparing a coating on the surface of a component to obtain a V-shaped structure, an H-shaped structure and a flat plate structure, and finally assembling the V-shaped structure, the H-shaped structure and the flat plate structure to form the hollow front edge structural component. According to the method, preparation of the hollow leading edge structural member made of the carbon fiber reinforced ceramic matrix composite can be achieved, mold removal is convenient, and the mold can be repeatedly used.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material molding, and more specifically to a molding method and a molding device for a high-temperature resistant hollow leading edge structure. Background Art

[0002] Carbon fiber reinforced ceramic matrix composites have the unique advantages of ceramic materials such as high hardness, high strength, high temperature resistance, oxidation resistance, corrosion resistance, low density, and good wear resistance at high temperatures. At the same time, the introduction of carbon fiber reinforcements with high specific strength and high specific modulus improves the brittleness of ceramic materials and achieves the reinforcement and toughening of the ceramic matrix.

[0003] At present, carbon fiber reinforced ceramic matrix composites have become one of the important thermal structural material systems in the aerospace field, and are being used more and more widely in the fields of aero-engine hot end components, advanced aircraft thermal protection systems, and braking systems.

[0004] The aircraft leading edge structure is an important part of the aircraft wing. It is located at the front of the wing and has an important impact on the aerodynamic performance, structural stability and flight safety of the aircraft. The leading edge design needs to consider aerodynamic efficiency, structural strength and durability, and usually uses high-strength, lightweight materials such as aluminum alloys and titanium alloys. High-temperature resistant leading edges require materials that can withstand high temperatures to ensure that the integrity and performance of the structure are maintained in high-temperature environments. C / SiC ceramic-based composites can withstand higher temperatures than traditional high-temperature alloys. Usually, the temperature resistance limit of high-temperature alloys is maintained at around 1100°C, while C / SiC composites can reach 1200-1350°C or even higher. The density of C / SiC composites is usually lower than that of aluminum alloys and titanium alloys, which helps to reduce the weight of the aircraft and improve fuel efficiency. In addition, C / SiC composites have better mechanical properties as well as oxidation resistance and corrosion resistance. It has become a development trend to gradually replace traditional high-temperature alloy materials in the application of aircraft high-temperature resistant leading edge structures.

[0005] The hollow leading edge structure is a special design of the leading edge of the aircraft. The hollow structure means that the entire part of the component is hollow, which can reduce the use of materials without sacrificing structural strength, thereby reducing weight. The strength and rigidity of the structure can also be increased by adding reinforcements such as ribs and partitions inside or outside the hollow component. The interior of the hollow leading edge of the aircraft is mainly used to fill metal blocks and aerogels. The metal blocks can be used as reinforcements to improve the structural strength, rigidity and impact resistance of the leading edge of the aircraft, so as to withstand greater aerodynamic loads. Aerogel has extremely low thermal conductivity and can effectively isolate high temperatures and protect the internal structure and equipment of the aircraft. Its porous structure can effectively absorb sound and improve the noise environment inside the aircraft. The hollow leading edge structure of ceramic-based composite materials is difficult to prepare in the current existing technology due to its complex shape. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] The technical problem to be solved by the present invention is that the hollow leading edge structure of the existing ceramic-based composite material is difficult to prepare.

[0008] (II) Technical solution

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] In a first aspect, the present invention provides a method for forming a high temperature resistant hollow leading edge structure, comprising the following steps:

[0011] Preparing a V-shaped structure preform, an H-shaped structure preform and a flat plate structure preform;

[0012] Design and manufacture corresponding V-shaped structure forming molds, H-shaped structure forming molds and flat structure forming molds;

[0013] Placing a V-shaped structure preform in the cavity of a V-shaped structure forming mold and fastening the V-shaped structure forming mold, placing an H-shaped structure preform in the cavity of an H-shaped structure forming mold and fastening the H-shaped structure forming mold, placing a flat plate structure preform in the cavity of a flat plate structure forming mold and fastening the flat plate structure forming mold to form a plurality of combined molds;

[0014] Placing a plurality of the combined molds into an impregnation liquid, and using a precursor impregnation and cracking method to perform a densification treatment on the V-shaped structure preform, the H-shaped structure preform, and the flat structure preform;

[0015] After the densification treatment is completed, the multiple combined molds are disassembled to obtain a V-shaped structure, an H-shaped structure and a flat plate structure respectively;

[0016] Processing the V-shaped structure, H-shaped structure and flat plate structure to obtain V-shaped parts, H-shaped parts and flat plate components with preset sizes;

[0017] Preparing a silicon carbide coating on the surfaces of the V-shaped member, the H-shaped member and the flat plate member;

[0018] The V-shaped member, the H-shaped member and the flat plate member are assembled to form a hollow leading edge structure.

[0019] Preferably, the preparation of the V-shaped structure preform, the H-shaped structure preform and the flat structure preform comprises the following steps:

[0020] The composite material raw material is woven into a V-shaped woven structure, an H-shaped woven structure and a flat woven structure, and an interface layer is deposited on the surface of the V-shaped woven structure, the H-shaped woven structure and the flat woven structure to obtain a V-shaped structure preform, an H-shaped structure preform and a flat structure preform respectively.

[0021] Preferably, the weaving method of the V-shaped structure preform is as follows: prepare carbon fiber 2D cloth, lay out a V-shaped preform of equal thickness according to the shape of the component to be formed, add layers in the thicker area and then sew them together.

[0022] Preferably, the weaving method of the H-shaped structural preform is as follows: prepare carbon fiber 2D cloth, lay two U-shaped preforms of equal thickness according to the shape of the component to be formed, so that the sum of the single side or middle thickness meets the requirements, and add layers and then sew in the area where the thickness does not meet the requirements.

[0023] Preferably, the material of the interface layer may include pyrolytic carbon, boron nitride and a composite interface layer.

[0024] Preferably, the impregnation liquid is a solid polycarbosilane organic solution or a polymethylsilane organic solution.

[0025] Preferably, the coating is a silicon carbide coating.

[0026] In a second aspect, the present invention further provides a molding device for implementing the high temperature resistant hollow leading edge structure molding method described in any one of the above technical solutions, the molding device comprising:

[0027] The V-shaped structure forming mold comprises an upper cover mold and a first bottom mold which are fastened to each other, and a cavity for forming the V-shaped structure is formed between the upper cover mold and the first bottom mold;

[0028] An H-shaped structure forming mold comprises a top cover mold, a second bottom mold and an inner mold which are fastened to each other, the H-shaped structure has a wide end and a narrow end, the inner mold is arranged in the narrow end, the top cover mold, the second bottom mold and the inner mold together form a cavity for forming the H-shaped structure, wherein the inner mold comprises a first side block, a second side block and a middle block, one side of the middle block is connected to the first side block, and the other side of the middle block is connected to the second side block.

[0029] Preferably, the first side block, the second side block and the middle block are bonded and connected by room temperature adhesive.

[0030] Preferably, the inner mold is provided with a draft angle along the length direction.

[0031] Preferably, the upper cover mold, the first bottom mold, the top cover mold and the second bottom mold are all provided with impregnation holes.

[0032] Preferably, it also includes a fastener, wherein the fastener is used to fasten the upper cover mold and the first bottom mold, and the fastener is used to fasten the top cover mold and the second bottom mold.

[0033] Preferably, the fasteners include bolts and pins.

[0034] Preferably, the mold manufacturing material is graphite with required strength and purity.

[0035] (III) Beneficial effects

[0036] The above technical solution of the present invention has at least the following advantages:

[0037] 1. In the present invention, the hollow leading edge structure with a relatively complex structural profile is split into three components, namely, a V-shaped component, an H-shaped component and a flat component, and then assembled after the molding is completed, thereby realizing the preparation of the hollow leading edge structure of the carbon fiber reinforced ceramic matrix composite material involved. The carbon fiber reinforced ceramic matrix composite material combines the characteristics of high melting point, high hardness and high modulus of the silicon carbide ceramic matrix and the excellent characteristics of continuous carbon fiber such as high temperature resistance, wear resistance and strong fracture toughness, so that the component has excellent mechanical properties and high temperature resistance.

[0038] 2. In the present invention, for H-shaped components with variable cross-sections, when the mold with a smaller opening needs to be pulled out along the length direction, direct pulling out will cause surface interference. The present invention splits the inner mold design of the H-shaped structure forming mold into a first side block, a second side block and a middle block. The first side block, the second side block and the middle block are bonded together with a room temperature adhesive. After high-temperature pyrolysis, the room temperature adhesive will decompose, and then the first side block, the second side block and the middle block will be disconnected. During demolding, the middle block will not interfere with other structures. After the middle block is pulled out, there is enough space for the first side block and the second side block to be taken out, thereby facilitating demolding. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 It is a schematic diagram of the structure of a molding device provided in an embodiment of the present invention.

[0041] Figure 2 It is a schematic structural diagram of a V-shaped member, an H-shaped member and a flat plate member provided in an embodiment of the present invention.

[0042] Figure 3It is a structural schematic diagram of the hollow leading edge structure provided by an embodiment of the present invention.

[0043] Figure 4 Schematic diagram of the structures of the V-shaped structure weaving mold and the H-shaped structure weaving mold provided in the embodiments of the present invention.

[0044] The reference numerals in the figures are:

[0045] 100. Hollow leading edge structure; 10. V-shaped member; 20. H-shaped member; 30. Flat plate member; 1. V-shaped structure forming mold; 2. H-shaped structure forming mold; 3. Impregnation hole; 4. Bolt hole; 5. Pin hole; 11. Upper cover mold; 12. First bottom mold; 21. Top cover mold; 22. Second bottom mold; 23. Inner mold; 231. First side block; 232. Second side block; 233. Middle block. DETAILED DESCRIPTION

[0046] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0047] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly located on the other element or indirectly located on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

[0048] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention, and do not indicate that a device or element 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.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating relative importance or indicating the number of technical features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The specific implementation of the present invention is described in more detail below in conjunction with specific embodiments:

[0050] like Figure 1 , Figure 2 and Figure 3 As shown, an embodiment of the present invention further provides a molding device, the molding device comprising:

[0051] The V-shaped structure forming mold 1 comprises an upper cover mold 11 and a first bottom mold 12 which are fastened to each other, and a cavity for forming the V-shaped structure is formed between the upper cover mold 11 and the first bottom mold 12;

[0052] The H-shaped structure forming mold 2 includes a top cover mold 21, a second bottom mold 22 and an inner mold 23 which are fastened to each other. The H-shaped structure has a wide end 202 and a narrow end 201. The inner mold 23 is arranged in the narrow end 201. The top cover mold 21, the second bottom mold 22 and the inner mold 23 together form a cavity for forming the H-shaped structure, wherein the inner mold 23 includes a first side block 231, a second side block 232 and a middle block 233. One side of the middle block 233 is connected to the first side block 231, and the other side of the middle block 233 is connected to the second side block 232.

[0053] In one embodiment, the first side block 231, the second side block 232 and the middle block 233 are bonded together by a room temperature adhesive. For a variable cross-section H-shaped component, when the mold with a small opening needs to be pulled out along the length direction, direct pulling out will cause surface interference. In this embodiment, the inner mold 23 is split into the first side block 231, the second side block 232 and the middle block 233. The first side block 231, the second side block 232 and the middle block 223 are bonded together with a room temperature adhesive (such as AB glue). After high temperature cracking, the room temperature adhesive will decompose. In this embodiment, the inner mold design of the H-shaped structure forming mold is split into the first side block, the second side block and the middle block. The first side block, the second side block and the middle block are bonded together with a room temperature adhesive. After high temperature cracking, the room temperature adhesive will decompose, and then the first side block, the second side block and the middle block will be disconnected. When demoulding, the middle block will not interfere with other structures. After the middle block is pulled out, the first side block and the second side block also have enough space to be taken out, which is convenient for demoulding.

[0054] In one embodiment, the inner mold 23 is provided with a draft angle along the length direction. Specifically, one end of the inner mold 23 is wider and the other end is narrower, forming a draft angle in the length direction. When demolding, the inner mold 23 is demolded from the narrow to the wide direction, which can reduce the friction of demolding and facilitate demolding of the component.

[0055] In one embodiment, the upper cover mold 11, the first bottom mold 12, the top cover mold 21 and the second bottom mold 22 are all provided with impregnation holes 3. Under the premise of ensuring the mechanical strength of the mold, the impregnation holes 3 are designed along a certain direction to facilitate the impregnation liquid to reach the component through the impregnation holes 3 to impregnate the component, thereby improving the impregnation efficiency.

[0056] In one embodiment, it further includes a fastener (not shown), the fastener fastens and connects the upper cover mold 11 and the first bottom mold 12 , and the fastener fastens and connects the top cover mold 21 and the second bottom mold 22 .

[0057] In one embodiment, the fasteners include bolts and pins. Specifically, bolt holes 4 and pin holes 5 are respectively arranged at corresponding positions on the V-shaped structure forming mold 1 and the H-shaped structure forming mold 2, and the bolts can be used to press and fasten the molds through the bolt holes, and the pins can be used to position and install the molds through the pin holes 5.

[0058] An embodiment of the present invention provides a method for forming a high temperature resistant hollow leading edge structure, which is implemented by any one of the forming devices in the above embodiments, and includes the following steps:

[0059] Preparing a V-shaped structure preform, an H-shaped structure preform and a flat plate structure preform;

[0060] Design corresponding V-shaped structure forming mold 1, H-shaped structure forming mold 2 and flat structure forming mold;

[0061] The V-shaped structure preform is placed in the cavity of the V-shaped structure forming mold 1 and is fastened to the V-shaped structure forming mold 1, the H-shaped structure preform is placed in the cavity of the H-shaped structure forming mold 2 and is fastened to the H-shaped structure forming mold 2, and the flat plate structure preform is placed in the cavity of the flat plate structure forming mold and is fastened to the flat plate structure forming mold to form a plurality of combined molds;

[0062] Placing a plurality of combined molds into an impregnation liquid, and using a precursor impregnation and cracking method to densify a V-shaped structure preform, an H-shaped structure preform, and a flat structure preform;

[0063] After the densification treatment is completed, the multiple combined molds are disassembled to obtain a V-shaped structure, an H-shaped structure and a flat plate structure respectively;

[0064] Machining the V-shaped structure, the H-shaped structure and the flat plate structure to obtain the V-shaped member 10, the H-shaped member 20 and the flat plate member 30 with preset dimensions;

[0065] A silicon carbide coating is prepared on the surfaces of the V-shaped member 10, the H-shaped member 20 and the flat member 30;

[0066] The V-shaped member 10, the H-shaped member 20 and the flat plate member 30 are assembled to form the hollow front edge structure 100. Specifically, the V-shaped member 10, the H-shaped member 20 and the flat plate member 30 can be fixedly assembled by bolt connection, such as Figure 3 As shown, connection holes 110 are provided at corresponding positions of the components for bolt connection, and fixed assembly can also be achieved by gluing. A flat plate component 30 is placed in the middle of the H-shaped member 20 to increase the strength and rigidity of the overall structure of the hollow front edge structure 100. The flat plate component 30 can also be designed as a flat plate structure with a variable cross-section according to structural requirements to achieve different strength reinforcement at different positions in the length direction of the component.

[0067] In one embodiment, preparing a V-shaped structure preform, an H-shaped structure preform, and a flat structure preform comprises the following steps:

[0068] The composite material raw material is woven into a V-shaped woven structure, an H-shaped woven structure and a flat woven structure, and an interface layer is deposited on the surface of the V-shaped woven structure, the H-shaped woven structure and the flat woven structure to obtain a V-shaped structure preform, an H-shaped structure preform and a flat structure preform respectively.

[0069] In one embodiment, the material of the interface layer may include pyrolytic carbon, boron nitride and a composite interface layer. Specifically, the composite interface layer may be an interface layer formed by pyrolytic carbon and boron nitride, or may be an interface layer composed of other materials.

[0070] In one embodiment, the impregnation liquid is a solid polycarbosilane organic solution or a solid polymethylsilane organic solution.

[0071] The present invention is further described in detail below in conjunction with the accompanying drawings and the following embodiments:

[0072] A method for forming a high temperature resistant and high temperature resistant hollow front edge structure, the dimensions of the three components are: V-type: 477mm×81mm×117mm, the thickness of both sides is 3mm, the thickness of the bottom is 8.8mm, H-type: 468mm×99mm×72mm, the thickness of both sides is 3mm, the thickness of the middle is 5mm, flat plate type: 450mm×57.3mm×6mm, the schematic diagram of the component is as follows Figure 1 shown.

[0073] The following is a specific embodiment provided by the present invention:

[0074] The high temperature resistant hollow leading edge structure forming method comprises the following steps:

[0075] Step 1, prepare V-type structure preform, H-type structure preform and flat plate structure preform: the dimensions of the three components to be prepared are as follows: the dimensions of the V-type component: 477mm×81mm×117mm, the thickness of both sides is 3mm, the thickness of the bottom is 8.8mm, the dimensions of the H-type component: 468mm×99mm×72mm, the thickness of both sides is 3mm, the thickness of the middle is 5mm, the dimensions of the flat plate component: 450mm×57.3mm×6mm. HF40-6K carbon fiber twill cloth is used as the raw material, and the 2D cloth stitching and weaving method is adopted. According to the manufacturing requirements, a continuous fiber preform is prepared by leaving margins in all directions. The dimensions of the V-type structure preform, H-type structure preform and flat plate structure preform are designed as follows: (1) V-type structure preform: leave a margin of 0.55mm on the inner and outer surfaces, and extend 5mm outward in all directions. The thickness of both sides is 4mm, 7 layers of 2D cloth, the top thickness A is 9.8mm, and 23 layers of 2D cloth. (2) H-type structural preform: the inner surface margin on both sides is 1.05mm, the outer surface margin is 0.55mm, and it extends 5mm outward in all directions. The thickness on both sides is 4.5mm, with 11 layers of 2D cloth, and the middle thickness B is 6mm, with 14 layers of 2D cloth. (3) Flat plate structural preform: The upper and lower surfaces each have a margin of 0.55mm, and extend 5mm outward in all directions. The thickness is 7mm, with 17 layers of 2D cloth. The fiber volume fraction of the preform is about 40%. Furthermore, the V-type structural preform, the H-type structural preform and the flat plate structural preform are all prepared by weaving. Specifically, Figure 4 As shown, the weaving method of the V-shaped structure preform is as follows: first, a V-shaped structure weaving mold is manufactured, and the V-shaped structure weaving mold 6 is an outer surface consistent with the inner cavity surface of the component, that is, a solid metal block with an outer contour of an inverted V shape, and a V-shaped preform of equal thickness is laid on the V-shaped structure weaving mold, and the number of layers of cloth required in a specific area is calculated according to the thickness, and then the added layers are evenly added between the laid cloths, and finally stitched to obtain the V-shaped structure preform. The weaving method of the H-shaped structure preform is as follows: an H-shaped structure weaving mold is manufactured, and the V-shaped structure weaving mold includes an upper mold 7 and a lower mold 8. The outer surface of the upper mold 7 is consistent with the inner cavity surface of the upper half of the H-shaped preform, and the outer surface of the lower mold 8 is consistent with the inner cavity surface of the lower half of the H-shaped preform, that is, two solid metal blocks with an outer contour of an inverted U shape, and a base plate can be set at the bottom. Two U-shaped preforms of equal thickness are laid flat on the upper mold 7 and the lower mold 8, and the middle position is sewn after the middle thickness meets the requirements, and finally layers are added on both sides of the H shape to meet the thickness requirements and then sewn to obtain an H-shaped structural preform. When the thickness of the middle position is thicker, layers can also be added in the middle after the thickness of both sides meets the requirements.

[0076] A pyrolytic carbon (PyC) interface layer is prepared on the surface of a V-type structure preform, an H-type structure preform and a flat structure preform. The process is: methane is used as the carbon source, vacuum is drawn before deposition, the deposition temperature is 1150°C, the furnace pressure is maintained at about 3Kpa, the flow rate is 2000ml / min, the deposition time is 20h, and the weight gain is 20% to 30%.

[0077] Step 2, design the corresponding V-shaped structure forming mold 1, H-shaped structure forming mold 2 and flat structure forming mold, specifically including the following steps: design and manufacture the finalizing mold (V-shaped structure forming mold 1, H-shaped structure forming mold 2 and flat structure forming mold) according to the shape and size of the intended forming component (V-shaped component 10, H-shaped component 20 and flat component 30). Use UG to design and draw the mold. The mold cavity structure is consistent with the prefabricated structure. The mold design is as follows: Figure 1 As shown. A groove is set above the upper cover mold 11 of the V-type structure forming mold 1 to reduce the weight of the mold, and the inner mold 23 of the H-type structure forming mold 2 is divided into three parts (the first side block 231, the second side block 232 and the middle block 233) to facilitate demolding. Flat-type components generally do not require specially designed molds. They are placed between two graphite plates and a heavy object is pressed on them. The dimensions of the V-type structure forming mold 1 are: 535mm×197mm×190mm, and the dimensions of the H-type structure forming mold 2 are: 488mm×228mm×143mm. Both the V-type structure forming mold 1 and the H-type structure forming mold 2 are made of high-purity graphite materials for mold manufacturing.

[0078] Step 3, placing the V-shaped structure preform in the cavity of the V-shaped structure forming mold 1, and fastening the V-shaped structure forming mold 1, placing the H-shaped structure preform in the cavity of the H-shaped structure forming mold 2, and fastening the H-shaped structure forming mold 2, placing the flat structure preform in the cavity of the flat structure forming mold, and fastening the flat structure forming mold to form a plurality of combined molds; placing the plurality of combined molds in the impregnation liquid to densify the V-shaped structure preform, the H-shaped structure preform and the flat structure preform, specifically comprising the following steps: selecting a solid polycarbosilane (PCS) organic solution with a mass concentration of 50wt% as the impregnation liquid, using the traditional PIP process to densify the V-shaped structure preform, the H-shaped structure preform and the flat structure preform, and demolding after 10 times of impregnation-cracking. The mold can be removed during the densification process or after the densification is completed. For the H-shaped structure forming mold 2, when demoulding, the top cover mold 21 is first removed, and then the middle block 233, the first side block 231, the second side block 232 are removed in sequence, and finally the second bottom mold 22 is removed to obtain a V-shaped structure, an H-shaped structure and a flat plate structure.

[0079] Step 4: Mechanically process the V-shaped structure, H-shaped structure and flat plate structure to obtain V-shaped parts, H-shaped parts and flat plate components with preset sizes, and prepare components with shapes and sizes that meet the requirements.

[0080] Step 5: Prepare a silicon carbide coating on the surface of the V-shaped member 10, the H-shaped member 20 and the flat member 30, which is specifically achieved in the following manner: the gas source is methyltrichlorosilane (MTS), the deposition temperature is 1180°C, the pressure is 8KPa, the deposition time is 20h, and the molar ratio of the flow rate of MTS to H2 is 1:8. The thickness of the prepared silicon carbide coating is about 0.05mm.

[0081] Step 6, assemble the V-shaped member 10, the H-shaped member 20 and the flat plate member 30 to form a hollow leading edge structure 100: drill holes at corresponding positions, and connect the V-shaped member, the H-shaped member and the flat plate member together by bolting to obtain the hollow leading edge structure 100.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for forming a high temperature resistant hollow leading edge structure, characterized in that: The following steps are involved: Preparing a V-shaped structure preform, an H-shaped structure preform and a flat plate structure preform; Design and manufacture corresponding V-shaped structure forming molds, H-shaped structure forming molds and flat structure forming molds; Placing a V-shaped structure preform in the cavity of a V-shaped structure forming mold and fastening the V-shaped structure forming mold, placing an H-shaped structure preform in the cavity of an H-shaped structure forming mold and fastening the H-shaped structure forming mold, placing a flat plate structure preform in the cavity of a flat plate structure forming mold and fastening the flat plate structure forming mold to form a plurality of combined molds; Placing a plurality of the combined molds into an impregnation liquid, and using a precursor impregnation and cracking method to perform a densification treatment on the V-shaped structure preform, the H-shaped structure preform, and the flat structure preform; After the densification treatment is completed, the multiple combined molds are disassembled to obtain a V-shaped structure, an H-shaped structure and a flat plate structure respectively; Processing the V-shaped structure, H-shaped structure and flat plate structure to obtain V-shaped parts, H-shaped parts and flat plate components with preset sizes; Prepare a coating on the surface of the V-shaped member, the H-shaped member and the flat plate member; The V-shaped member, the H-shaped member and the flat plate member are assembled to form a hollow leading edge structure.

2. The method for forming a high temperature resistant hollow leading edge structure according to claim 1, characterized in that: The preparation of the V-shaped structure preform, the H-shaped structure preform and the flat structure preform comprises the following steps: The composite material raw material is woven into a V-shaped woven structure, an H-shaped woven structure and a flat plate woven structure, and an interface layer is deposited on the surface of the V-shaped woven structure, the H-shaped woven structure and the flat plate woven structure to obtain a V-shaped structure preform, an H-shaped structure preform and a flat plate structure preform, respectively.

3. The high temperature resistant hollow leading edge structure forming method according to claim 2, characterized in that: The material of the interface layer may include pyrolytic carbon, boron nitride and a composite interface layer, and the coating is a silicon carbide coating.

4. A molding device, characterized in that: Used to implement the high temperature resistant hollow leading edge structure forming method according to any one of claims 1 to 3, the forming device comprises: The V-shaped structure forming mold comprises an upper cover mold and a first bottom mold which are fastened to each other, and a cavity for forming the V-shaped structure is formed between the upper cover mold and the first bottom mold; An H-shaped structure forming mold comprises a top cover mold, a second bottom mold and an inner mold which are fastened to each other, the H-shaped structure has a wide end and a narrow end, the inner mold is arranged in the narrow end, the top cover mold, the second bottom mold and the inner mold together form a cavity for forming the H-shaped structure, wherein the inner mold comprises a first side block, a second side block and a middle block, one side of the middle block is connected to the first side block, and the other side of the middle block is connected to the second side block.

5. The molding device according to claim 4, characterized in that: The first side block, the second side block and the middle block are bonded and connected by room temperature adhesive.

6. The molding device according to claim 4, characterized in that: The inner mold is provided with a draft angle along the length direction.

7. The molding device according to claim 4, characterized in that: The upper cover mold, the first bottom mold, the top cover mold and the second bottom mold are all provided with impregnation holes.

8. The molding device according to claim 4, characterized in that: It also includes a fastener, which is used to fasten the upper cover mold and the first bottom mold, and the fastener is used to fasten the top cover mold and the second bottom mold.

9. The molding device according to claim 8, characterized in that: The fasteners include bolts and pins.

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