Method for controlling interface layer preparation uniformity of large-size ceramic matrix composite parts

Abstract

The present application relates to a kind of large size ceramic matrix composite part interface layer preparation uniformity control method.Solve the technical problem that interface layer is not uniform in the method for preparing large size ceramic matrix composite part interface layer of existing preparation.The present application method includes the following steps:1) L carbon cloth block string is hung in effective area;2) N carbon cloth block string is hung in most effective area;Carbon cloth block on carbon cloth block string is respectively wrapped using different layers of carbon cloth;3) deposition;4) the relative deposition efficiency η1 of effective area and most effective area is calculated;5) the relative deposition efficiency η2 of carbon cloth block wrapped with different layers of carbon cloth and carbon cloth block in most effective area is calculated respectively;Obtain the best wrapping layer number λ;6) calculate each furnace time of deposition;7) the part is deposited, and adjacent furnace parts are respectively positive and upside down;Part in most effective area is always wrapped with carbon cloth of λ layer in corresponding furnace, to control the interface layer uniformity of each area of part.

Description

TECHNICAL FIELD

[0001] The application relates to a ceramic matrix composite interface layer preparation method, in particular to a large-size ceramic matrix composite part interface layer preparation uniformity control method. BACKGROUND

[0002] As a new type of thermal structure / function integrated strategic material, the ceramic matrix composite has the characteristics of low density, high temperature resistance, high specific strength, high specific modulus, oxidation resistance, ablation resistance, crack insensitivity and no catastrophic damage, and is widely used in key fields such as aviation, aerospace, nuclear power and photovoltaic. The ceramic matrix composite product is usually assembled by a plurality of parts with different structures and sizes. The special structure of the outer part, such as the skin part, has a relatively large size, and the height size is greater than 1500mm, so the part interface layer preparation uniformity is crucial to the performance of the product.

[0003] The ceramic matrix composite part interface layer mainly protects the fibers from corrosion by harmful gases (such as HCl gas generated during deposition of the SiC matrix), reduces the thermal expansion difference between the fibers and the SiC matrix, fully utilizes the load-bearing capacity of the fibers, and makes the composite material have excellent fracture behavior. The ceramic matrix composite part interface layer preparation must be subjected to chemical vapor infiltration (CVI), and if the part is prepared in the most effective area of the deposition equipment, a uniform interface layer can be obtained. If the size of the part is greater than the most effective area of the deposition equipment, the part will have an uneven interface layer deposition phenomenon during preparation. Taking a 2000mm*1000mm flat plate as an example, according to the conventional process, the part will have a thicker interface layer in the middle region and a thinner interface layer in the upper and lower end regions, which seriously affects its performance. SUMMARY

[0004] The purpose of the present application is to solve the technical problem of uneven deposition of the interface layer of the existing large-size ceramic matrix composite part interface layer preparation method, and to provide a large-size ceramic matrix composite part interface layer preparation uniformity control method.

[0005] The technical solution of the present application is:

[0006] The large-size ceramic matrix composite part interface layer preparation uniformity control method of the present application adopts chemical vapor deposition furnace deposition, and the chemical vapor deposition furnace is divided into an effective area, a most effective area and a non-furnace area from bottom to top along the height direction, and the special feature is that the method comprises the following steps:

[0007] 1) Prepare the required number of carbon cloth blocks according to the preset requirements and weigh the total weight, string into L carbon cloth block strings, evenly hang L carbon cloth block strings in the effective area, evenly hang the same number of carbon cloth blocks on each carbon cloth block string, the length of the carbon cloth block string is adapted to the height of the effective area, and the upper and lower ends of each carbon cloth block string are respectively provided with carbon cloth blocks; L is a positive integer greater than or equal to 3;

[0008] 2) Again, prepare the required number of carbon cloth blocks according to the preset requirements and weigh the total weight, string into N carbon cloth block strings, evenly hang N carbon cloth block strings in the most effective area, evenly hang d carbon cloth blocks on each carbon cloth block string, the length of the carbon cloth block string is adapted to the height of the most effective area, and the upper and lower ends of each carbon cloth block string are provided with carbon cloth blocks; The d carbon cloth blocks on each carbon cloth block string are wrapped with 1 layer, 2 layers, 3 layers, …, d layers of carbon cloth respectively; d is a positive integer, and N is a positive integer greater than or equal to 3;

[0009] 3) Set the deposition parameters to be the same as the deposition parameters of the part to be deposited, and perform deposition for a specified duration;

[0010] 4) Weigh all carbon cloth blocks in the effective area and the most effective area respectively; Calculate the average weight gain rate m1 of the carbon cloth blocks in the effective area and the average weight gain rate m2 of the carbon cloth blocks in the most effective area; and calculate the relative deposition efficiency η1 of the effective area and the most effective area, η1 = m1 / m2;

[0011] 5) Group the carbon cloth blocks with the same number of carbon cloth layers into d groups; remove the wrapped carbon cloth from each group of carbon cloth blocks and weigh them again; Calculate the average weight gain m3 of each group of carbon cloth blocks, and calculate the relative deposition efficiency η2, η2 = m3 / m2; After all calculations are completed, find the carbon cloth layer number λ corresponding to η2 that is closest to the value of η1, and record it;

[0012] 6) Calculate the deposition time t of each furnace of the part according to the deposition time formula;

[0013] 7) Keep the deposition parameters unchanged, deposit the part for n times, n is an even number greater than or equal to 4, and the deposition time of each furnace is t; wherein, the parts of adjacent furnaces are respectively placed in the positive direction and the inverted direction; The placement position of each furnace of the part needs to ensure that the end edge of the part facing upwards is located at the upper limit position of the most effective area; After the first two furnaces are deposited, mark the part that is always in the most effective area in the positive direction and the inverted direction; Before the last two furnaces are deposited, use λ layers of carbon cloth to wrap the marked area of the part as in step 2), and obtain a large-size ceramic matrix composite part with uniform interface layer after all furnace depositions.

[0014] Further, in step 6), the deposition time formula is:

[0015] t = 2T / [n(1+η1)]

[0016] T is the total deposition time required to produce the same interface layer thickness of the part in the conventional technique.

[0017] Further, in step 1) and step 2), the interval between adjacent carbon cloth blocks on each carbon cloth block string is 120-150 mm.

[0018] Further, in step 1) and step 2), the size of the carbon cloth block is 50*50 mm.

[0019] Further, the carbon cloth block in step 1) and the carbon cloth block in step 2) are the same; the carbon cloth block in step 1) uses any one of 1K carbon fiber, 3K carbon fiber, 6K carbon fiber and 12K carbon fiber.

[0020] Further, in step 2), the carbon cloth used for wrapping is any one of 1K carbon fiber, 3K carbon fiber, 6K carbon fiber and 12K carbon fiber.

[0021] Further, in step 1), L is the same as N in step 2), and L is 3.

[0022] Further, in step 7), before deposition, a graphite pad is placed between the bottom end of the part and the furnace bottom plate to ensure that the edge of the upward end of the part is located at the upper limit position of the most effective area.

[0023] The beneficial effects of the present application are:

[0024] 1. The present application is a method for controlling the uniformity of the interface layer of a large-sized ceramic matrix composite part, which suspends carbon cloth blocks in the most effective area and the effective area for deposition, and simultaneously wraps the carbon cloth blocks in the most effective area with different numbers of carbon cloth layers, respectively calculates the relative deposition efficiency when the carbon cloth is wrapped, and the relative deposition efficiency when the wrapped carbon cloth is removed, to obtain the optimal number of carbon cloth wrapping layers; during the deposition process of the part, the part is preferentially placed in the most effective area of the equipment, and deposition preparation is performed by turning around on the basis of the part placement mode in each furnace. If the size of the part is larger than the most effective area of the equipment, most of the part area needs to be placed in the most effective area of the equipment, and the remaining small part area needs to be placed in the effective area of the equipment, and the deposition is adjusted by multiple furnaces and multiple times of turning around to ensure the interface layer preparation requirements. Since the middle area of the part is always in the most effective area of the equipment in multiple furnaces, the number of wrapping layers obtained by the carbon cloth block experiment is used for carbon cloth wrapping in the interface deposition preparation process of this area (the reason: there are pores on the surface of the carbon cloth, and the reaction gas will be reduced to adhere to the surface of the part during the preparation process), the deposition preparation amount of the interface layer in this area is reduced, and then the thickness of the interface layer of each area of the part is more uniform, and is within the process requirements, solving the problem of local deposition unevenness in the interface CVI preparation process of the ceramic matrix composite part.

[0025] 2. The method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part, wherein the deposition efficiencies of different devices and different areas are different. When a large-size part is prepared for the first time in a certain device, the deposition efficiencies of different areas are unknown, so the size of η1 must be determined through experiments, and then the number of layers of the carbon cloth wrapping is determined.

[0026] 3. The method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part, wherein the interval between adjacent carbon cloth blocks is 120-150 mm, and the interval size limits the number of carbon cloth blocks. In principle, the smaller the interval between the carbon cloth blocks, the more accurate the effective deposition efficiency calculation.

[0027] 4. The method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part, wherein the number of carbon cloth block strings is 3, and the more the number of strings, the more accurate the effective deposition efficiency calculation. However, the more processes are more complex, so the process content is reduced as much as possible while ensuring the deviation degree and efficiency.

[0028] 5. The method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part, which is suitable for devices of different sizes and specifications. As long as the height size of the part is greater than the most effective area of the device, the method is suitable. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The figure shows the area division of the chemical vapor deposition furnace used in the embodiment of the method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part;

[0030] Figure 2 The figure shows the vertical division area of the flat plate part selected in the embodiment of the method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part;

[0031] Figure 3 The figure shows the display of the flat plate part placed vertically in the furnace (furnaces 1 and 3) in the embodiment of the method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part;

[0032] Figure 4 The figure shows the display of the flat plate part placed vertically in the furnace (furnaces 1 and 3) in the embodiment of the method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part;

[0033] Figure 5 The figure shows the position of the carbon cloth block suspended in the chemical vapor deposition furnace in the embodiment of the method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part;

[0034] Figure 6The result display diagram of SEM detection of the plate part after deposition in different areas in the embodiment of the method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part is shown in the figure, wherein the figures (a)-(f) are SEM detection result diagrams of six different areas, respectively.

[0035] The figure shows the chemical vapor deposition furnace used in the embodiment of the method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part. DETAILED DESCRIPTION

[0036] The method is described in detail below through specific embodiments and the accompanying drawings.

[0037] The method for controlling the uniformity of the interface layer of a large-size ceramic matrix composite part adopts chemical vapor deposition furnace deposition, and the chemical vapor deposition furnace is divided into the deposition effective area 4, the deposition most effective area 3 and the non-furnace area 2 from bottom to top along the height direction. Figure 1 Taking the well chamber furnace equipment specification Φ1200×2400mm as an example, the uppermost end of the equipment is the furnace cover 1, and the lowermost end is the furnace bottom disc 5; the non-furnace area 2 of the equipment deposition is the safe height area of the equipment furnace loading, which is convenient for the introduction and diffusion of the reaction gas, such as the upper area shown in the figure. Figure 1 The most effective area 3 of the equipment is the equipment uniform temperature area, and the part deposition efficiency is the highest, such as the shadow area shown in the figure. Figure 1 The effective area 4 of the equipment is the equipment non-uniform temperature area, and the part deposition efficiency is relatively poor, such as the bottom area shown in the figure. Figure 1

[0038] The part in this embodiment is SiC / SiC or C / SiC composite material fiber fabric, taking a size of 2000mm×1000mm plate as an example, carbon interface layer deposition is carried out, the carbon interface layer deposition thickness requirement of the plate part is 150-250nm, and the deposition process parameters are controlled by 4 furnace times (the part is deposited every furnace time), the deposition process parameters are unchanged every furnace time, the effective deposition time of each area of the part is T, T is the total time required for preparing the same interface layer thickness of the part with a size less than the most effective area in the conventional technology, and T in this embodiment is 160h.

[0039] The specific interface layer preparation includes the following steps:

[0040] ​1) Prepare the required number of carbon cloth blocks 7 according to the preset requirements and weigh the total weight (use an electronic balance with an accuracy of 0.0001 g), string L carbon cloth block strings, and evenly hang L carbon cloth block strings in the effective area 4. The same number of carbon cloth blocks 7 are evenly hung on each carbon cloth block string. The size of the carbon cloth block 7 is 50x50 mm. The length of the carbon cloth block string is adapted to the height of the effective area 4. The upper and lower ends of each carbon cloth block string are respectively provided with carbon cloth blocks 7. The spacing between adjacent carbon cloth blocks 7 on each carbon cloth block string is 120-150 mm. L is a positive integer greater than or equal to 3.

[0041] 2) Again, prepare the required number of carbon cloth blocks 7 according to the preset requirements and weigh the total weight, string N carbon cloth block strings, and evenly hang N carbon cloth block strings in the most effective area 3. d carbon cloth blocks 7 are evenly hung on each carbon cloth block string. The size of the carbon cloth block 7 is 50x50 mm. The length of the carbon cloth block string is adapted to the height of the most effective area 3. The upper and lower ends of each carbon cloth block string are respectively provided with carbon cloth blocks 7. The spacing between adjacent carbon cloth blocks 7 on each carbon cloth block string is 120-150 mm. The d carbon cloth blocks 7 on each carbon cloth block string are wrapped with 1 layer, 2 layers, 3 layers, …, d layers of carbon cloth. d is a positive integer, and N is a positive integer greater than or equal to 3.

[0042] Step 1 and step 2) hanging carbon cloth block strings refer to Figure 5 , the same carbon cloth block 7 can be any one of 1K carbon fiber, 3K carbon fiber, 6K carbon fiber, and 12K carbon fiber. The carbon cloth used for wrapping in step 2) can be any one of 1K carbon fiber, 3K carbon fiber, 6K carbon fiber, and 12K carbon fiber. In this embodiment, 1K carbon cloth is used for wrapping. In this embodiment, L and N are the same, and the effective area 4 and the most effective area 3 respectively use 3 carbon cloth block strings. Under the condition that the accuracy is not affected, the use of carbon cloth block strings is minimized to make the process simpler and more convenient, fast and efficient. The carbon cloth block strings are hung in the effective area 4 and the most effective area 3, respectively, and the deposition interface layer prepared by the deposition of the carbon cloth block strings is used to determine the efficiency of the deposition of the parts. The deposition state of the parts can be adjusted according to the determination results in the later stage.

[0043] 3) Set the deposition parameters to be the same as the deposition parameters of the parts to be deposited, and perform 10h of deposition;

[0044] 4) After the furnace is opened, weigh all the carbon cloth blocks 7 in the effective area 4 and weigh all the carbon cloth blocks 7 in the most effective area 3 according to the division area. Calculate the average weight gain rate m1 of the carbon cloth blocks 7 in the effective area 4 and the average weight gain rate m2 of the carbon cloth blocks 7 in the most effective area 3. Calculate the relative deposition efficiency η1 of the parts in the effective area 4 and the most effective area 3, η1 = m1 / m2, and substitute the data as η1 = 0.31% / 0.51% = 0.61;

[0045] 5) For the carbon cloth blocks 7 in the most effective area 3, first group the carbon cloth blocks 7 with the same number of carbon cloth wrapping layers into d groups. Remove the 1K carbon cloth wrapping from each group of carbon cloth blocks 7 and weigh them. Calculate the average weight gain m3 of each group of carbon cloth blocks 7 and the relative deposition efficiency η2, η2 = m3 / m2. After calculating the average weight gain m3 of each group and the relative deposition efficiency η2 of each group, find the number of carbon cloth layers λ for the group whose value η2 is closest to η1 and record λ as 2.

[0046] Calculated values ​​for each group:

[0047]

[0048] 6) Deposition is performed for 4 times. The deposition time t of each part is calculated according to the deposition time formula:

[0049] The formula for sedimentation time is:

[0050] t=2T / [n(1+η1)]

[0051] n is the deposition furnace number, and n is an even number ≥ 4;

[0052] T is the total deposition time required to prepare the same interface layer thickness for parts smaller than the most effective area in conventional technology.

[0053] Substituting the data into the calculation, we can obtain t=T / [2(1+η1)]=t=2×160 / [4(1+0.61)]≈50h.

[0054] 7) The deposition process parameters of each furnace remain unchanged, and 4 furnaces of chemical vapor infiltration deposition are performed on the flat parts, and the deposition time of each furnace is t; among them, the parts of adjacent furnaces are placed upright and upside down respectively (that is, they are turned around before the next furnace deposition); the placement of the parts of each furnace must ensure that the upward end of the part is located at the upper limit of the most effective area 3; after the first two furnaces of deposition, the marked parts are always in the most effective area 3 when placed upright or upside down; before the third and fourth furnaces of deposition, the marked area of ​​the parts is wrapped with the same λ layer of carbon cloth as in step 2), and after all furnaces of deposition, a large-sized ceramic-based composite part with an interface layer uniformity that meets the requirements is obtained. The structure of the part is as follows Figure 2 As shown, the middle 1000mm area is always in the most effective area 3. Before deposition, a graphite pad is placed between the bottom end of the part and the furnace bottom plate 5 to ensure that the upward end of the part is located at the upper limit of the most effective area 3.

[0055] The first furnace, the flat plate parts are fixed vertically in the center of the furnace, the large end of the part is downward, and the bottom end is padded with 100mm graphite pad between the furnace bottom plate 5 (to ensure that the part is located in the most effective area 3 of the equipment). The 500mm height area of the large end of the part is in the effective area 4 of the equipment, and the remaining area of the part is in the most effective area 3 of the equipment, and the furnace loading mode is as shown in Figure 3 After the equipment is closed, the part is subjected to chemical vapor infiltration, and the first furnace deposition time is 50h.

[0056] The second furnace, after the equipment is opened, the flat plate parts are fixed vertically in the center of the furnace, the small end of the part is downward, and the bottom end is padded with 100mm graphite pad between the furnace bottom plate. The 500mm height area of the small end of the part is in the effective area 4 of the equipment, and the remaining area of the part is in the most effective area 3 of the equipment, and the furnace loading mode is as shown in Figure 4 After the equipment is closed, the part is subjected to chemical vapor infiltration, and the second furnace deposition time is 50h.

[0057] The third furnace, after the equipment is opened, the middle height 1000mm area of the part is marked (always in the most effective area 3 of the equipment), as shown in Figure 2 At the same time, the flat plate parts are fixed vertically in the center of the furnace, the large end of the part is downward, and the bottom end is padded with 100mm graphite pad between the furnace bottom plate. The 500mm height area of the large end of the part is in the effective area 4 of the equipment, and the remaining area of the part is in the most effective area 3 of the equipment, and the furnace loading mode is as shown in Figure 3 After the equipment is closed, the part is subjected to chemical vapor infiltration, and the third furnace deposition time is 50h.

[0058] The fourth furnace, after the equipment is opened, the flat plate parts wrapped with carbon cloth are fixed vertically in the center of the furnace, the small end of the part is downward, and the bottom end is padded with 100mm graphite pad between the furnace bottom plate. The 500mm height area of the small end of the part is in the effective area 4 of the equipment, and the remaining area of the part is in the most effective area 3 of the equipment, and the furnace loading mode is as shown in Figure 4 After the equipment is closed, the part is subjected to chemical vapor infiltration, and the fourth furnace deposition time is 50h.

[0059] After the deposition of the four furnaces, samples are taken in different areas of the flat plate parts, and the interface layer is detected by SEM, and the results are as shown in Figure 6 The SEM detection results of the four different areas of the flat plate parts which are always in the most effective area 3 during deposition are as shown in Figure 6 (a), (b), (c), (d) shown in Figure 6 The thickness in (a) is 190-240nm, Figure 6 The thickness in (b) is 191-223nm, Figure 6(c) the average thickness was 181 nm, Figure 6 (d) the average thickness was 196 nm; two different areas of the flat part deposited at the position of the effective area 4 were sampled, and the SEM detection results are as follows Figure 6 as shown in the middle (e) and (f), Figure 6 (e) the average thickness was 220 nm, Figure 6 (f) the average thickness was 238 nm. The results show that the flat part deposited according to the method of the present application has a small thickness deviation of different areas, meets the process deviation range requirement, and the interface layer uniformity of each area is good.

Claims

1. A method for controlling the uniformity of the interface layer of a large-sized ceramic matrix composite part, deposited by a chemical vapor deposition furnace, the chemical vapor deposition furnace being divided from bottom to top along the height direction into an effective area (4), a most effective area (3) and a non-furnace area (2), characterized in that, It comprises the following steps: 1) Prepare the required number of carbon cloth blocks (7) according to the preset requirements and weigh the total weight, string into L carbon cloth block strings, and uniformly hang L carbon cloth block strings in the effective area (4). Each carbon cloth block string uniformly suspends a plurality of carbon cloth blocks (7) with the same number, the length of the carbon cloth block string is adapted to the height of the effective area (4), and the upper and lower ends of each carbon cloth block string are respectively provided with carbon cloth blocks (7); L is a positive integer greater than or equal to 3; 2) Again, prepare the required number of carbon cloth blocks (7) according to the preset requirements and weigh the total weight, string into N carbon cloth block strings, and uniformly hang N carbon cloth block strings in the most effective area (3). Each carbon cloth block string uniformly suspends d carbon cloth blocks (7), the length of the carbon cloth block string is adapted to the height of the most effective area (3), and the upper and lower ends of each carbon cloth block string are provided with carbon cloth blocks (7). The d carbon cloth blocks (7) on each carbon cloth block string are wrapped with 1 layer, 2 layers, 3 layers, …, d layers of carbon cloth respectively; d is a positive integer, and N is a positive integer greater than or equal to 3; 3) Set the deposition parameters to be the same as the deposition parameters of the part to be deposited, and perform deposition for a specified duration; 4) Weigh all carbon cloth blocks (7) in the effective area (4) and the most effective area (3) respectively; calculate the average weight gain rate m1 of the carbon cloth blocks (7) in the effective area (4) and the average weight gain rate m2 of the carbon cloth blocks (7) in the most effective area (3); and calculate the relative deposition efficiency η1 of the effective area (4) and the most effective area (3), η1 = m1 / m2; 5) Divide the carbon cloth blocks (7) with the same number of carbon cloth layers into the same group, a total of d groups; remove the carbon cloth wrapped around each group of carbon cloth blocks (7) and weigh again; calculate the average weight gain m3 of each group of carbon cloth blocks (7) respectively, and calculate the relative deposition efficiency η2, η2 = m3 / m2; After all calculations are completed, find the carbon cloth layer number λ corresponding to η2 that is closest to the value of η1, and record it; 6) Calculate the deposition time t of each furnace of the part according to the deposition time formula; 7) Deposit the part for n furnaces, n is an even number greater than or equal to 4, the deposition time of each furnace is t, and the deposition parameters remain unchanged; wherein, the parts of adjacent furnaces are respectively placed in the positive and inverted positions; The placement position of each furnace part needs to ensure that the end of the part facing upwards is located at the upper limit position of the most effective area (3); After the first two furnaces are deposited, mark the part that is always in the most effective area (3) in the positive and inverted positions; Before the last two furnaces are deposited, use λ layers of carbon cloth to wrap the marked area of the part, and all furnace depositions are completed to obtain a large-size ceramic matrix composite part with uniform interface layer.

2. The method according to claim 1, wherein the deposition time formula in step 6) is: t = 2T / [n(1+η1)] T is the total deposition time required to prepare the same interface layer thickness for a part with a size smaller than the most effective area in conventional technology.

3. The method according to claim 1 or 2, wherein ​ In step 1) and step 2), the interval between adjacent carbon cloth blocks (7) is 120-150 mm.

4. The method according to claim 3, wherein the method is characterized in that: In step 1) and step 2), the size of the carbon cloth block (7) is 50*50 mm.

5. The method according to claim 4, wherein the method is characterized in that: The carbon cloth block (7) in step 1) is the same as the carbon cloth block (7) in step 2); The carbon cloth block (7) in step 1) is made of any one of 1K carbon fiber, 3K carbon fiber, 6K carbon fiber and 12K carbon fiber.

6. The method according to claim 5, wherein the method is characterized in that: In step 2), the carbon cloth used for wrapping is any one of 1K carbon fiber, 3K carbon fiber, 6K carbon fiber and 12K carbon fiber.

7. The method according to claim 6, wherein the method is characterized in that: In step 1), L is the same as N in step 2), and L is 3.

8. The method according to claim 7, wherein the method is characterized in that: In step 7), before deposition, a graphite pad is placed between the bottom end of the part and the furnace bottom plate (5) to ensure that the upward end of the part is located at the upper limit position of the most effective area (3).

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