A processing method for ceramic-based and carbon / carbon composite material components

Abstract

This application relates to a method for processing ceramic-based and carbon / carbon composite components. The method includes: obtaining the dimensional change of a resin-based composite material when converted into a target composite component and calculating the corresponding shrinkage rate; the shrinkage rate is obtained through preliminary experiments; reconstructing processing parameters for the resin-based composite component based on the net dimensional processing parameters of the target composite component and the shrinkage rate by inverse calculation; and processing the resin-based composite component based on the reconstructed processing parameters and experimental parameters from the preliminary experiments, and further preparing the target composite component. This method can reduce processing costs, reduce the difficulty of maintaining processing equipment, improve processing efficiency, and produce high-precision composite components.

Description

Technical Field

[0001] The present application relates to the technical field of composite material component processing, and in particular to a processing method for ceramic-based and carbon / carbon composite material components. Background Art

[0002] The processing technology of ceramic-based and carbon / carbon composite components plays an extremely important role in the preparation of composite materials and their components. Taking the processing of ceramic-based composites and their components as an example, when using the precursor conversion (PIP) process and chemical vapor infiltration (CVI) process to prepare C / SiC and SiC / SiC, and the reactive melt infiltration (RMI) process to prepare C / C-SiC and SiC / C-SiC, multiple machining operations are often required to obtain high-precision composite components.

[0003] The existing processing technology has the following deficiencies:

[0004] First, the cost of machining tools is high. Due to the high hardness of ceramic substrates such as SiC, expensive diamond tools and c-BN tools must be used. Even with high-hardness machining tools, they wear quickly during the machining process, requiring frequent tool replacement to ensure machining accuracy, resulting in high consumption and increased machining costs.

[0005] Secondly, the processing time is long. Due to the high brittleness of SiC and C matrices, and the fact that the machining tools are arranged in small, sharp-angled granules, the contact area between the tool and the workpiece is small during machining, resulting in small feed and slow cutting speed, long processing time and low processing efficiency.

[0006] Third, machining equipment is difficult to protect and susceptible to severe damage. The fine carbon fiber dust generated during machining, due to its high conductivity, can easily interfere with the electrical systems of machining equipment, even causing short circuits and burns. Ceramic dust, such as SiC, is very hard, making it difficult for negative pressure vacuum protection devices to completely remove it. Once inside the equipment, it can cause severe wear and tear on bearings, guide rails, and screws, compromising accuracy at best and even rendering the equipment useless at worst.

[0007] Precision machining equipment with numerous moving parts, such as those on three-, four-, and five-axis machines, is particularly challenging to maintain. Consequently, machining ceramic-based and carbon / carbon composite materials has become a significant challenge in manufacturing technology. Overall, machining costs for ceramic-based and carbon / carbon composite materials can account for over 30% of total manufacturing costs, and for complex components, even over 50%.

[0008] Current research on ceramic-based and carbon / carbon composite machining technologies focuses primarily on optimizing tool materials, machining parameters, and protective measures for machining equipment. Jian Ke (doctoral dissertation at the National University of Defense Technology) investigated the timing of machining C / SiC using the PIP process. He concluded that machining is relatively easy after four to five densification cycles. Beyond five, the SiC content in the matrix gradually increases, leading to a rapid increase in milling difficulty (indicating increased wear on diamond tools). While the paper addressed the issue of machining timing, it failed to address issues of machining accuracy and component deformation.

[0009] A few reports involve rough machining during the resin-based composite molding stage to reduce the amount of processing required for the final ceramic-based composite. For example, Frenkel (Walter Frenkel and Ralph Renz, Chapter 16, CMCs for Friction Applications, in Ceramic Matrix Composites (Fiber Reinforced Ceramics and their applications), Ed. Walter Frenkel, Wiley-VCH, 2008) reports that, when preparing C / C-SiC brake pads, after compression molding the resin-based composite, preliminary machining is performed to remove excess scrap. After siliconization is complete, fine machining is then performed. Summary of the Invention

[0010] Based on this, it is necessary to provide a processing method for ceramic-based and carbon / carbon composite components to address the above technical problems, so as to reduce processing costs and the difficulty of maintaining processing equipment, while improving processing efficiency and obtaining high-precision composite components.

[0011] The present invention provides a method for processing ceramic-based and carbon / carbon composite material components, comprising:

[0012] Obtaining the dimensional change when the resin-based composite material is converted into a target composite component and calculating the corresponding shrinkage rate; the shrinkage rate is obtained through preliminary experiments; the target composite component is a ceramic-based composite component or a carbon / carbon composite component;

[0013] The reconstructed processing parameters of the resin-based composite component are obtained by inverse calculation based on the net size processing parameters and shrinkage rate of the target composite component;

[0014] A resin-based composite material component is obtained by processing according to the reconstructed processing parameters and the experimental parameters of the preliminary experiment, and a target composite material component is further prepared.

[0015] The present invention creatively proposes: by accurately determining the shrinkage rate of the composite material during the preparation process, the precision machining of ceramic-based and carbon / carbon composite components is converted into the easy-to-carry precision machining of resin-based composite components. After the composite process is completed, the finished component meets the net dimensional accuracy requirements.

[0016] The outstanding advantages of the present invention are:

[0017] 1. Wide adaptability. The core of this technical solution is to advance difficult machining processes for materials like ceramics and transform them into easily accessible resin-based composite materials, significantly reducing the difficulty of producing high-precision composite components. Therefore, this solution can be used in any application where component dimensions constantly change during the molding and fabrication process.

[0018] 2. Significant reduction in processing costs. Due to the transformation of the processing stage, this solution significantly reduces processing costs in three aspects: First, ordinary, inexpensive white steel knives can meet the processing requirements of resin-based composite components, saving a lot of costs compared to expensive diamond and c-BN tools. Second, processing time is significantly shortened: because the processing parameters (feed amount and cutting speed) are an order of magnitude higher than those of diamond tools, processing time is reduced, and corresponding costs are reduced. Third, equipment damage is less, equipment protection is reduced, and equipment parts replacement is reduced, which also reduces costs.

[0019] 3. The difficulty of protecting processing equipment is significantly reduced. The background technology has already detailed the serious damage caused to processing equipment during the processing of ceramic-based and carbon / carbon composite materials. In addition, small feed amounts and slow tool speeds will generate finer dust. Longer processing times lead to greater accumulation of dust, which seriously damages the equipment. Conventional vacuum negative pressure extraction devices are difficult to effectively remove these harmful dusts.

[0020] This patented technology for precision machining of resin-based composite components completely eliminates the wear and tear of equipment caused by high-hardness ceramic dust. Furthermore, large chip size generated by high tool feed rates and rapid tool movement allows simple air settling to remove most of the dust, including conductive carbon fibers, which are often encapsulated in resin and are less likely to form floating debris, thus posing no threat to the equipment's electrical system. Furthermore, wet machining can be easily performed. These combined factors simplify the protection of machining equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1 is a schematic flow chart of a method for processing a ceramic-based and carbon / carbon composite material component in one embodiment;

[0022] Figure 2 Schematic diagram of a two-dimensional plane profile curve of a simple profile component in one embodiment;

[0023] Figure 3 A schematic diagram of the outer surface curved surface of a three-dimensional complex profile component in one embodiment;

[0024] Figure 4 A schematic diagram of the dimensional technical requirements for a C / SiC product in one embodiment;

[0025] Figure 5 A processing drawing obtained by inversion and reconstruction in one embodiment;

[0026] Figure 6 This is a drawing of the net dimensions of a C / C product in one embodiment.

[0027] Figure 7 is the z value (z i ) Schematic diagram of the curve after the intersection of the isoplane and the component. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0029] In one embodiment, Figure 1 As shown, a method for processing ceramic-based and carbon / carbon composite components is provided, comprising the following steps:

[0030] Step 102 : Obtain the dimensional change when the resin-based composite material is converted into a target composite material component and calculate the corresponding shrinkage rate.

[0031] The shrinkage rate is obtained through preliminary experiments. It is understood that the raw materials and process parameters used in the preliminary experiments are consistent with those used in the formal production process. The target composite component is a ceramic matrix composite component or a carbon / carbon composite component.

[0032] Step 104 , obtaining the reconstructed processing parameters of the resin-based composite material component by inverse calculation based on the net size processing parameters and shrinkage rate of the target composite material component;

[0033] That is, based on the net size drawing of the target composite material component, and taking into account the dimensional changes (i.e., shrinkage rate) during the preparation of the target composite material, the processing drawings of the resin-based composite material component are inverted and reconstructed to facilitate the subsequent precision processing of the component at the resin-based composite material stage. In other words, the difficult precision processing of ceramic-based and carbon / carbon composite material components is converted into the easy precision processing of resin-based composite material components.

[0034] Step 106 : Processing a resin-based composite material component according to the reconstructed processing parameters and the experimental parameters of the preliminary experiment to obtain a target composite material component.

[0035] The ceramic-based and carbon / carbon composite material components can be prepared using existing technologies.

[0036] After the processing of the resin-based composite material component is completed according to the reconstructed processing parameters and the densification of the target composite material is completed, the dimensional accuracy of the target composite material component meets the dimensional accuracy requirements required for the finished component.

[0037] Furthermore, obtaining the dimensional change when the resin-based composite material is converted into the target composite material component and calculating the corresponding shrinkage rate includes:

[0038] Determine the material system and process system for preparing the target composite material; the material system includes the fibers, fiber preforms, ceramic matrix and / or carbon matrix used; the process system includes the preparation process and corresponding process parameters; conduct preliminary experiments based on the material system and process system to obtain the dimensional changes of the resin-based composite material when it is converted into the target composite material during the preliminary experiment, and calculate the corresponding shrinkage rate.

[0039] The preparation of target composite components primarily involves molding fiber preforms, filling ceramic and carbon matrices, and machining. Different composite systems exhibit varying dimensional changes (shrinkage) in various directions due to differences in fibers, fiber preforms, preparation processes, and process parameters.

[0040] Taking a T300 3K carbon cloth laminate preform (fiber volume fraction 55%, thickness 5mm) as an example, polycarbosilane (PCS) / divinylbenzene (DVB) was used as the impregnation liquid, hot-pressed with a mold on a hot press, and after curing, the thickness was controlled using a graphite mold. The preform was then pyrolyzed at high temperatures to 1200°C. After repeated impregnation-curing-pyrolysis cycles, the flat plate component remained unchanged in thickness, but exhibited a shrinkage of 2.4‰ to 2.6‰ in length and width.

[0041] The shrinkage rates in various directions of other material systems, including target composite materials prepared by different processes, are determined using the same method.

[0042] Furthermore, the target composite material components and resin-based composite material components include two-dimensional simple profile components and three-dimensional complex profile components;

[0043] Two-dimensional simple surface components include plane surface components and arc surface components; plane surface components can be placed in a two-dimensional plane coordinate system; the edges and dimensions of arc surface components can be fully displayed in a two-dimensional plane coordinate system;

[0044] The three-dimensional surface component is located in a three-dimensional space coordinate system.

[0045] If the target composite component and the resin-based composite component are two-dimensional simple surface components, the reconstructed processing parameters of the resin-based composite component are obtained by inverse calculation based on the net size processing parameters and shrinkage rate of the target composite component, including:

[0046] Obtaining various plane profile curves of the target composite material component in the dimensional direction corresponding to the shrinkage rate; the plane profile curves are obtained based on the net size processing parameters;

[0047] When the plane profile curve has no symmetrical point and no sudden change point, the starting point of the plane profile curve is used as the reference point to calculate the net length from the starting point to the end point;

[0048] When the plane contour curve has a symmetrical point or a mutation point, the plane contour curve is segmented using the symmetrical point or the mutation point as a reference point to obtain a plurality of corresponding plane contour sub-curves, and the net length of each plane contour sub-curve is calculated respectively;

[0049] The reconstruction length of the corresponding plane profile curve or plane profile sub-curve is obtained according to the net length and the shrinkage rate, and the reconstruction processing parameters of the corresponding dimensional direction of the resin-based composite material component are calculated according to the reconstruction length and the curve function, starting point and ending point of the corresponding plane profile curve or plane profile sub-curve.

[0050] For two-dimensional simple surface components, such as plates, cylinders, and drums, it is only necessary to perform calculation corrections within the two-dimensional plane. To facilitate the explanation of the calculation process, the thickness dimension remains unchanged, the contour curve within the plane is y = f(x), and the dimensional shrinkage rate is α, such as Figure 2 As shown, a schematic diagram of the two-dimensional plane contour curve of a simple profile component is provided.

[0051] Taking point A as the reference, the net length of the component is the length L0 between A-A'. The length ΔL between any two points on the curve is:

[0052] ΔL 2 =(Δx) 2 +(Δy) 2 =(dx) 2 +(dy) 2

[0053] =(dx) 2 +(f'(x)) 2 (dx) 2

[0054] ={1+[f'(x)] 2}(dx) 2

[0055]

[0056] Considering the shrinkage rate α of the resin-based composite material when it is converted into the target composite material, the processing curve length L′ is:

[0057] L'=L0 / (1-α)

[0058] At this time, the coordinates of the point A in the middle of the curve length AA can be calculated by the following formula:

[0059]

[0060] Except for the endpoint A", the coordinates of each point on AA" can be obtained by the above formula, and then the processing drawing can be reconstructed by inversion.

[0061] If the curve has a symmetrical point, the symmetrical point can be used as the reference point. If the curve has a sudden change (such as a 90-degree bend), the processing coordinates can use the sudden change point as the reference point and generate processing drawings in sections.

[0062] Furthermore, if the target composite material component and the resin-based composite material component are three-dimensional complex surface components, the reconstructed processing parameters of the resin-based composite material component are obtained by inverse calculation based on the net size processing parameters and shrinkage rate of the target composite material component, including:

[0063] Obtaining the arc surface of the target composite material component in the dimensional direction corresponding to the shrinkage rate; the arc surface is obtained based on the net size processing parameters;

[0064] When a component has an axis of symmetry, the axis of symmetry is used as the reference line and the reference point is determined;

[0065] When a component has a center of symmetry, the center of symmetry is used as the reference point and the reference line is determined;

[0066] When the cambered surface has a sudden curve, the sudden curve is used as the reference line and the reference point is determined;

[0067] When the arc surface does not have an axis of symmetry, a center of symmetry, or a sudden curve, any boundary line of the arc surface is used as the reference line, and the midpoint of the reference line is used as the reference point;

[0068] Dividing the baseline into at least two sub-baselines based on the baseline point, obtaining a first reconstruction length of the corresponding sub-baseline according to the length and shrinkage rate of the sub-baseline, and calculating a reconstruction processing parameter of the baseline direction according to the first reconstruction length and the curve function, starting point, and ending point of the corresponding sub-baseline;

[0069] Intercept the arc surface with any plane passing through the reference point to obtain the corresponding intercept curve intersecting the arc surface;

[0070] The net length from the reference point to any point on the intercepted curve is calculated. The second reconstructed length from the reference line to the corresponding point on the intercepted curve is obtained based on the net length and the shrinkage rate. The reconstruction processing parameters in the intercepted curve direction are calculated based on the second reconstructed length and the corresponding curve function of the arc surface, the reference point and the corresponding point.

[0071] For three-dimensional complex surface components, the coordinates of the points on the surface in the processing diagram can also be inverted and reconstructed. To facilitate the explanation of the calculation process, the thickness direction dimension is assumed to be unchanged, and only the inner and outer surfaces of the component are considered. Figure 3 As shown, a schematic diagram of the outer surface curve of a three-dimensional complex surface component is provided.

[0072] Taking the outer surface as an example, the arc surface is AA'B'B, and the surface equation is ξ=f(x,u). The AB line is the reference line, the midpoint H of the AB line is the reference point, and the midpoint of A'B' is H'.

[0073] Since HA and HB are straight lines, the extension points A1 and B1 on the machining drawing can be simply calculated:

[0074]

[0075]

[0076] If HA and HB are also curves, the coordinates of their extension points A1 and B1 can be calculated using the formulas in the aforementioned simple profile components.

[0077] If the outer surface is intercepted by any plane passing through point H, an intersecting curve is obtained. The length ΔL between any two adjacent points on the curve is:

[0078] ΔL 2 =(Δx) 2 +(Δy) 2 +(Δξ) 2 =(dx) 2 +(dy) 2 +(dξ) 2

[0079] because so:

[0080]

[0081] The net length L0 from point H to any point G on the arc surface is:

[0082]

[0083] Processing drawing length L':

[0084] L′=L0 / (1-α)

[0085] Based on this, we can find the vertical coordinate (x G' ,y G' );ξ G' Calculated by ξ=f(x,y).

[0086]

[0087] Thus, the machining profile can be reconstructed by inverse calculation. Similarly, the inner profile can also be reconstructed by inverse calculation.

[0088] The same treatment is performed as for simple surface components. For components with an axis of symmetry or a center of symmetry, the axis of symmetry or the center of symmetry can be used as a reference to perform inversion reconstruction of the processing drawings. For cases where there are mutations on three-dimensional surfaces, the mutation curve (surface) can be used as the reference line (surface), and the coordinates of the points on both sides of the mutation curve (surface) can be calculated to obtain the processing drawing.

[0089] Obviously, the inversion reconstruction method of a two-dimensional simple surface component is a simple treatment for a three-dimensional complex surface component. In short, through the above processing method, the net size drawing of the target composite component can be converted into the processing drawing of the resin-based composite stage component.

[0090] Furthermore, processing the resin-based composite material component according to the reconstructed processing parameters and further preparing the target composite material component includes:

[0091] S1. Performing fiber surface treatment on the fiber preform;

[0092] S2, vacuum impregnating and molding the fiber preform obtained in step S1;

[0093] S3, processing the resin-based composite material obtained in step S2 according to the reconstructed processing parameters;

[0094] S4, performing high-temperature pyrolysis on the resin-based composite material obtained in step S3; the high-temperature pyrolysis is performed according to the existing preparation process parameters of the target composite material;

[0095] S5. Repeat the impregnation-curing-high-temperature cracking process for the composite material obtained in step S4 at least 4 times to obtain a target composite material component.

[0096] Furthermore, in step S1, the fiber preform is prepared by a general preform preparation process, such as one of unidirectional fiber laying, needle felt, fiber cloth lamination, 2.5D weaving, 3D weaving, or winding molding; depending on the requirements of the composite material, the fiber can be one or more of carbon fiber, SiC fiber, Si3N4 fiber, asphalt fiber, or graphite fiber;

[0097] Step S1 specifically includes: according to the requirements of the composite material preparation process, adopting a general fiber surface treatment process, such as CVD preparation of C, BN and / or SiC coating, resin impregnation-high temperature cracking to prepare cracked carbon, SiC, SiCN and / or BN coating, acid treatment to remove fiber surface sizing agent, high temperature heat treatment to remove surface sizing agent, in order to obtain a good fiber / matrix bonding interface.

[0098] Furthermore, in step S2, based on the specific requirements of the target composite material, a corresponding ceramic precursor is selected, such as one or more of polycarbosilane, polynitrosilane, polysiloxane, or polyborazane; the carbon matrix comprises one or more of phenolic resin or furan resin; and solvents, crosslinking agents, catalysts, initiators, etc. are added as necessary. Common molding processes for resin-based composite components are employed, such as net shape, compression molding, vacuum bag molding, and autoclave molding. Molds may be used as necessary to assist in resin infusion and curing.

[0099] Furthermore, the machining equipment used in step S3 includes one or more of a CNC milling machine, a CNC lathe, a CNC grinder or an electric spark wire cutting machine;

[0100] The processing tools are white steel tools or carbide tools, and the processing parameters (feed amount, cutting speed, etc.) follow the process parameters of ordinary resin-based composite materials. Generally, the feed amount and cutting speed are an order of magnitude higher than those of diamond tools and c-BN tools for ceramic-based and carbon / carbon composite materials.

[0101] Furthermore, when the ceramic-based material component is a C / C-SiC component, the resin-based composite material is a C / C blank, and step S5 includes: repeating the impregnation-curing-high-temperature cracking of the composite material of step S4 at least twice and then performing vapor phase siliconization to obtain a ceramic-based composite material component.

[0102] C / C-SiC is prepared by vapor phase siliconization. Since no additional products are attached to the surface of the porous C / C blank during the process, and the dimensional change from the porous C / C blank to the final C / C-SiC product is constant, precision machining can be performed at the porous C / C blank stage after considering the dimensional change. The accuracy of the final product after siliconization meets the design requirements.

[0103] In order to facilitate those skilled in the art to better understand the present invention, the content of the present invention is further explained below with reference to specific embodiments.

[0104] Comparative Example 1

[0105] S1: Preparation of fiber preforms

[0106] Take Japan Toray T300 3K fiber plain weave fabric (surface density 198g / m 2), cut into 1050mm×520mm size, a total of 25 sheets, stacked and sutured with T300 3K single-strand fiber, with a suture spacing of 10mm×10mm.

[0107] S2: Fiber surface treatment

[0108] A carbon coating with a thickness of 250 nm was deposited on the fiber surface of the fiber preform using a CVD process (950°C, 2 kPa, CH4 / H2).

[0109] S3: Resin-based composite molding

[0110] PCS (softening point 190℃) / DVB=1 / 1 (weight ratio) is used as the impregnation liquid. After vacuum impregnation, the product is cured and molded on a hot press with a graphite flat mold clamped at 120℃ / 1h, 150℃ / 1h, and 180℃ / 1h.

[0111] S4: Precision machining of resin-based composite flat panels

[0112] On the CNC machining center, white steel milling cutter is used to process composite materials to obtain the size (Unmachined) composite material flat plate.

[0113] S5: High temperature cracking

[0114] Under inert atmosphere, the processed composite material plate and two graphite plate molds (bolted together) were pyrolyzed according to the following pyrolysis schedule:

[0115] When the temperature is between room temperature and 300°C, the heating rate is 15°C / min;

[0116] When the temperature is 300-800℃, the heating rate is 10℃ / min;

[0117] When the temperature is 800-1200℃, the heating rate is 5℃ / min;

[0118] When the temperature reaches 1200℃, keep it warm for 1 hour.

[0119] S6: Repeated impregnation-curing-pyrolysis

[0120] Repeat the above steps S3 and S5 7 times to obtain a finished C / SiC flat plate.

[0121] After measurement, the dimensions of the finished C / SiC flat plate are: thickness 5.50mm, length 997.56mm, width 498.78mm, and shrinkage rate is 2.46‰.

[0122] Example 1

[0123] S1: Net dimension drawing of C / SiC products.

[0124] The dimensional technical requirements for C / SiC products are as follows: Figure 4 As shown, unit: mm.

[0125] S2: Determination of the processing drawings of resin-based composite material flat panels

[0126] According to the requirements of the net dimension drawing of C / SiC products, considering the in-plane shrinkage of 2.46‰ (corresponding to the process), the center of the length and width of the plate is determined as the reference line, and the intersection of the center lines is used as the reference. The inversion and reconstruction of the processing drawings are as follows: Figure 5 As shown, unit: mm.

[0127] Since the thickness of the flat plate component is controlled by the flat plate mold, only the periphery and through holes need to be processed.

[0128] S3: Preparation of fiber preform

[0129] Same as Comparative Example 1.

[0130] S4: Fiber surface treatment

[0131] Same as Comparative Example 1

[0132] S5: Resin-based composite flat panel molding

[0133] Same as Comparative Example 1

[0134] S6: Precision machining of resin-based composite flat panels

[0135] According to the processing drawings, the processing process is the same as that of comparative example 1. Based on the symmetrical center of the blank, the burrs around the blank are removed as evenly as possible.

[0136] S7: High-temperature cracking

[0137] The high temperature cracking system is the same as that of Comparative Example 1.

[0138] It should be noted that after high-temperature cracking, due to the low content of the matrix, the cleaning should focus on the surface and try not to touch the surrounding area.

[0139] S8: Repeated impregnation-curing-pyrolysis

[0140] Same as Comparative Example 1

[0141] After densification, clean the inner wall and surrounding edges of the hole manually with fine sandpaper.

[0142] After testing, the final dimensions of the C / SiC flat plate are: thickness 5.50mm; length (required ): 999.96, 999.96, 999.98mm (three measuring points); width (required ): 499.94, 499.96, 499.96mm (three measuring points); aperture (required ): 12.0, 12.02, 12.02 (three holes); hole spacing (required ): 250.02, 250.02mm, both meet the dimensional accuracy requirements.

[0143] Comparative Example 2

[0144] The steps of this comparative example are basically the same as those of comparative example 1, and the differences are described as follows:

[0145] S3: Forming of resin-based composite flat panels

[0146] Boron phenolic resin ethanol solution (concentration 50%) is used as the impregnation liquid. After vacuum impregnation of the fiber preform, it is formed on a hot press using a graphite flat plate as a mold. The curing system is: 80℃ / 1h, 120℃ / 2h.

[0147] S5: High temperature cracking

[0148] The cracking system is as follows:

[0149] When the temperature is between room temperature and 300°C, the heating rate is 15°C / min;

[0150] When the temperature is 300-800℃, the heating rate is 3℃ / min;

[0151] When the temperature is 800-1200℃, the heating rate is 5℃ / min;

[0152] When the temperature reaches 1200℃, keep it warm for 1 hour.

[0153] After the lysis is completed, clean the surface of the plate, weigh it, and measure its size.

[0154] S6: Repeated impregnation-curing-pyrolysis

[0155] Repeat the above steps S3 and S5 4 times to obtain a C / C flat plate product.

[0156] After measurement, the dimensions of the C / C flat plate are: thickness 5.50mm, length 997.90mm, width 498.94mm, and shrinkage rate is 2.1‰.

[0157] Example 2

[0158] S1: Net size drawing of C / C finished product

[0159] C / C product net size drawing as follows Figure 6 shown.

[0160] The technical requirements are as follows:

[0161] Thickness: 5.50mm (guaranteed by mold)

[0162] Part: Length (margin)

[0163] Width (margin)

[0164] Slotting: Length

[0165] width

[0166] Dimensional inspection: standard mold inspection

[0167] S2: Determination of processing drawings for resin-based composite components

[0168] First, the C / C product profile is rotated and translated in three-dimensional coordinates to obtain a certain z value (z i ) is the curve diagram after the intersection of the isoplane and the component, as shown in Figure 7 shown.

[0169] A certain level i The curve equation of the value (external surface A-A') is:

[0170] y=f(x)

[0171] y=2 / 3x3 / 2+z i

[0172] Then the length of the A-A' curve is

[0173]

[0174] The binomial expansion of is:

[0175]

[0176] Substituting into the above formula, we can use numerical integration to find L A-A’ .

[0177] Taking A (and the straight edge where A is located) as the reference line, after considering the shrinkage rate, the coordinates of the point A" corresponding to the extension of the curve A' can be calculated as follows:

[0178]

[0179] In this embodiment, α=2.1‰.

[0180] Similarly, the coordinates of all points on the A-A' curve can be calculated.

[0181] Transform zi The coordinates of all points on the surface can be calculated by the inversion and reconstruction of the surface processing drawings.

[0182] Similarly, the inner surface machining drawing can be obtained. The inner and outer surfaces are combined to obtain the inverse reconstructed machining drawing.

[0183] S3: Preparation of fiber preforms

[0184] Same as Comparative Example 2.

[0185] S4: Surface treatment of fibers

[0186] Same as Comparative Example 2.

[0187] S5: Resin-based composite component molding

[0188] Except that the graphite flat plate mold was changed to a contoured graphite mold, everything else was the same as in Comparative Example 2.

[0189] S6: Precision machining of resin-based composite components

[0190] On the three-axis CNC machining center, precision machining is carried out using white steel cutters according to the machining drawings.

[0191] S7: High-temperature cracking

[0192] The cracking system was the same as that of Comparative Example 2.

[0193] S8: Repeated impregnation-curing-pyrolysis

[0194] Same as Comparative Example 2.

[0195] After densification, manually clean the edges and grooved walls with fine sandpaper.

[0196] After testing, the C / C components and finished product standard inspection molds are in good condition and meet the dimensional accuracy requirements.

[0197] While various embodiments of the present invention have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limiting of the disclosed embodiments. Numerous modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. Therefore, the scope of the present invention shall be determined by the scope of the claims.

Claims

1. A method for processing ceramic-based and carbon / carbon composite material components, characterized in that: The method comprises: Obtaining a dimensional change when a resin-based composite material is converted into a target composite material component and calculating a corresponding shrinkage rate; the shrinkage rate is obtained through preliminary experiments; the target composite material component is a ceramic-based composite material component or a carbon / carbon composite material component; Obtaining reconstruction processing parameters of the resin-based composite material component by inverse calculation based on the net size processing parameters of the target composite material component and the shrinkage rate; Processing a resin-based composite component according to the reconstructed processing parameters and the experimental parameters of the preliminary experiment and further preparing a target composite component; The target composite material component and the resin-based composite material component include a two-dimensional simple profile component and a three-dimensional complex profile component; the two-dimensional simple profile component includes a plane profile component and a curved profile component; the plane profile component can be placed in a two-dimensional plane coordinate system; the edge line and size of the curved profile component can be fully displayed in the two-dimensional plane coordinate system; the three-dimensional complex profile component is located in a three-dimensional space coordinate system; If the target composite material component and the resin-based composite material component are two-dimensional simple surface components, the reconstruction processing parameters of the resin-based composite material component are obtained by inverse calculation based on the net size processing parameters of the target composite material component and the shrinkage rate, including: obtaining each plane contour curve of the target composite material component in the dimensional direction corresponding to the shrinkage rate; the plane contour curve is obtained based on the net size processing parameters; when the plane contour curve has no symmetry point and no mutation point, using the starting point of the plane contour curve as the reference point, calculating the net length from the starting point to the end point; when the plane contour curve has a symmetry point or a mutation point, dividing the plane contour curve with the symmetry point or the mutation point as the reference point to obtain corresponding multiple plane contour sub-curves, and calculating the net length of each plane contour sub-curve respectively; obtaining the reconstruction length of the corresponding plane contour curve or plane contour sub-curve based on the net length and the shrinkage rate; and calculating the reconstruction processing parameters of the resin-based composite material component in the corresponding dimensional direction based on the reconstruction length and the curve function, starting point and end point of the corresponding plane contour curve or plane contour sub-curve.

2. The method according to claim 1, characterized in that The step of obtaining the dimensional change when the resin-based composite material is converted into a target composite material component and calculating the corresponding shrinkage rate includes: Determining a material system and a process system for preparing a target composite material; the material system includes the fibers, fiber preforms, ceramic matrix and / or carbon matrix used; the process system includes the preparation process and corresponding process parameters; A preliminary experiment is conducted according to the material system and the process system to obtain the dimensional change of the resin-based composite material when it is converted into the target composite material during the preliminary experiment, and the corresponding shrinkage rate is calculated.

3. The method according to claim 1, characterized in that If the target composite material component and the resin-based composite material component are three-dimensional complex surface components, the reconstructed processing parameters of the resin-based composite material component obtained by inverse calculation based on the net size processing parameters of the target composite material component and the shrinkage rate include: Obtaining a curved surface of the target composite material component in a dimension direction corresponding to the shrinkage rate; the curved surface is obtained according to the net size processing parameters; When the component has an axis of symmetry, the axis of symmetry is used as a reference line and a reference point is determined; When the component has a center of symmetry, the center of symmetry is used as a reference point and a reference line is determined; When the arc surface has a sudden curve, the sudden curve is used as a reference line and a reference point is determined; When the arc surface does not have an axis of symmetry, a center of symmetry, or a sudden curve, any boundary line of the arc surface is used as a reference line, and the midpoint of the reference line is used as a reference point; Dividing the baseline into at least two sub-baselines based on the baseline point, obtaining a first reconstructed length of the corresponding sub-baseline according to the length of the sub-baseline and the shrinkage rate, and calculating a reconstructed processing parameter of the baseline direction according to the first reconstructed length and the curve function, starting point, and ending point of the corresponding sub-baseline; intercepting the arc surface with any plane passing through the reference point to obtain a corresponding intercepted curve intersecting the arc surface; Calculate the net length from the reference point to any point on the intercepted curve, obtain a second reconstructed length from the reference line to the corresponding point on the intercepted curve based on the net length and the shrinkage rate, and calculate the reconstruction processing parameters in the intercepted curve direction based on the second reconstructed length and the corresponding arc surface curve function, reference point and corresponding point.

4. The method according to claim 1, wherein The resin-based composite material component is obtained by processing according to the reconstructed processing parameters and further prepared to obtain the target composite material component, including: S1. Performing fiber surface treatment on the fiber preform; S2, vacuum impregnating and molding the fiber preform obtained in step S1; S3, processing the resin-based composite material obtained in step S2 according to the reconstructed processing parameters; S4, performing high-temperature cracking on the resin-based composite material obtained in step S3; S5. Repeat the impregnation-curing-high-temperature cracking process for the composite material obtained in step S4 at least 4 times to obtain a target composite material component.

5. The method according to claim 4, characterized in that In step S1, the fiber preform is prepared by one of unidirectional fiber laying, needle felt, fiber cloth lamination, 2.5D weaving, 3D weaving, or winding; wherein the fiber is one or more of carbon fiber, SiC fiber, Si3N4 fiber, asphalt fiber, or graphite fiber; The step S1 specifically includes: Any one of CVD preparation of C, BN and / or SiC coating, resin impregnation-high temperature cracking preparation of cracked carbon, SiC, SiCN and / or BN coating, acid treatment to remove fiber surface sizing agent, high temperature heat treatment to remove surface sizing agent.

6. The method according to claim 4, characterized in that The ceramic precursor used in step S2 includes one or more of polycarbosilane, polynitrosilane, polysiloxane or polyborazane; The carbon matrix includes one or more of a phenolic resin or a furan resin; The forming process is one of net forming, compression forming, vacuum bag forming and autoclave forming.

7. The method according to claim 4, characterized in that The machining equipment used in step S3 includes one or more of a CNC milling machine, a CNC lathe, a CNC grinder or an electric spark wire cutting machine; The processing tools are white steel knives or carbide knives.

8. The method according to claim 4, characterized in that When the ceramic-based composite material component is a C / C-SiC component, the resin-based composite material is a C / C blank; The step S5 comprises: repeating the impregnation-curing-high temperature cracking process at least twice on the composite material described in step S4 and then performing vapor phase siliconization to obtain a ceramic matrix composite material component.

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