A rapid preparation method of carbide ultra-high temperature ceramic-siC gradient and uniform modified C / C composite material

Abstract

The present application belongs to the technical field of matrix modified C / C composite material preparation, and particularly relates to a rapid preparation method of carbide ultra-high temperature ceramic-SiC gradient and uniform modified C / C composite material. The present application combines SPS technology with matrix modified C / C composite material preparation technology to achieve the purpose of rapid preparation. The present method has low fiber damage, the internal ceramic phase of the prepared material is tightly combined with the matrix, the laid powder can fully penetrate into the matrix, the caking and waste phenomenon of the accumulated powder outside the sample is avoided, and meanwhile, the powder penetration depth can be controlled by controlling the total amount of the powder laid on the upper and lower matrix, the SPS pressure and the reaction temperature to prepare gradient and uniform modified C / C composite material, so that the controllability is high. The present method has short preparation period, and the modified C / C composite material can be prepared within 1-2 hours, so that the present method is suitable for large-scale and low-cost preparation of carbon-based / ceramic-based composite material.

Description

Technical Field

[0001] This invention pertains to the preparation method of matrix-modified C / C composite materials, and relates to a rapid preparation method for carbide ultra-high temperature ceramic-SiC gradient and uniformly modified C / C composite materials. Background Technology

[0002] C / C composites are prone to oxidation and ablation damage under high-temperature and aerobic conditions, leading to a significant decrease in their mechanical properties and severely hindering their widespread application. Introducing oxidation inhibitors or anti-ablation components into the matrix for matrix modification is one of the most effective methods to address this problem. Therefore, researchers have proposed methods such as precursor impregnation pyrolysis, chemical vapor infiltration, chemical liquid vapor deposition, reactive melting, and slurry impregnation to introduce ultra-high-temperature ceramic phases into the C / C matrix, effectively improving the oxidation / ablation resistance of C / C composites.

[0003] CN116120095B reports a method for preparing gradient ultra-high temperature ceramic-modified C / C composite materials using selective area reactive infiltration. This method prepares selectively HfC-SiC gradient-modified C / C composite materials by modifying the powder preparation process in the reactive infiltration process and adopting a powder placement method with a certain area coverage. However, this method results in excess silicate powder laid on the outside of the matrix agglomerating and failing after high-temperature heat treatment, leading to waste and high preparation costs.

[0004] CN105016760B reports a method for preparing ultra-high temperature ceramic-modified C / C composite materials. This method uses chemical liquid phase vapor deposition technology to obtain ultra-high temperature ceramic-modified C / C composite materials, which can obtain uniformly distributed ultra-high temperature ceramics in the C / C composite materials, effectively improving the oxidation / ablation resistance of the C / C composite materials. However, this method has a preparation cycle of more than ten hours, and because the edges are prone to crusting during the preparation process, it is not conducive to the densification of the sample, resulting in a large number of internal defects.

[0005] Reference 1, "Miao Q, Fu YQ, Chen H, Zhang JH, Zhao JH, Zhang YL, Simultaneous enhancement of mechanical and ablation properties of C / C composites modified by (Hf-Ta-Zr)C solid solution ceramics, Journal of the European Ceramic Society, 43(2023)_3182-3190", describes the introduction of (Hf-Ta-Zr)C single-phase solid solution ceramics into C / C composites using a precursor impregnation pyrolysis method to prepare (Hf-Ta-Zr)C modified C / C composites. This method involved repeating the precursor impregnation pyrolysis process 10–12 times, with a preparation cycle lasting several months.

[0006] Reference 2, “Zhao RD, Hu CL, Wang YH, Pang SY, Li J, Tang SF, Cheng HM, Construction of sandwich-structured C / C-SiC and C / C-SiC-ZrC composites with good mechanical and anti-ablation properties, Journal of the European Ceramic Society, 42(2022)_1219-1226”, describes the preparation of four types of sandwich-structured C / C-SiC and C / C-SiC-ZrC composites using a combined process of electromagnetically coupled chemical vapor infiltration and precursor impregnation pyrolysis. This method involves a complex preparation process, requiring the impregnation, curing, and pyrolysis processes to be repeated ten times, resulting in a lengthy preparation cycle. Summary of the Invention

[0007] To address the shortcomings of existing matrix modification methods, such as significant damage to carbon fibers, raw material waste, long preparation cycles, and weak bonding between the ceramic phase and the matrix, this invention proposes a rapid preparation method for carbide-modified ultra-high temperature ceramic-SiC gradient and uniformly modified C / C composite materials. This method combines SPS technology with matrix-modified C / C composite material preparation technology to achieve rapid preparation. To achieve the above objectives, this invention adopts the following technical solution:

[0008] A rapid preparation method for carbide ultra-high temperature ceramic-SiC gradient and uniformly modified C / C composite materials, characterized by the following steps:

[0009] Step 1: Ultrasonically clean the low-density C / C with anhydrous ethanol and dry it in a far-infrared drying oven at 80-100℃ for 20-24 hours;

[0010] The low-density C / C ratio described above has a density of approximately 0.9–1.4 g / cm³. 3 .

[0011] Step 2: Pour the powder into a ball mill jar and ball mill it using a planetary ball mill to obtain silicide powder;

[0012] The powder is one or more of HfSi2, ZrSi2, TiSi2, TaSi2, NbSi2, etc., mixed in different proportions;

[0013] The ball mill rotation speed is 400-600 r / min;

[0014] The ball milling time is 8–12 hours;

[0015] The ball-milled powder is dried in a far-infrared drying oven at 50–100°C for 10–15 hours.

[0016] Step 3: As Figure 1 As shown in (a), a certain mass of silicate powder is evenly spread on top of low-density C / C, graphite paper is wrapped around the bottom of low-density C / C and around the low-density C / C and powder, and placed above the lower punch of the SPS mold. Graphite paper of the same shape is placed on top of the powder, and finally the upper punch is pressed in.

[0017] The mass of the silicide powder to be laid is calculated by the volume of the open pores in the area to be penetrated and the mixing density of the powder. The area to be penetrated depends on the degree of gradient of the required material and the performance requirements.

[0018] When the volume of the open pores in the desired infiltration region is equal to the volume of the open pores in the entire low-density C / C composite material, a carbide ultra-high temperature ceramic-SiC homogeneously modified C / C composite material can be obtained, such as... Figure 1 As shown in (b), it is necessary to ensure that half the mass of silicide powder is laid on the upper and lower surfaces of the low-density C / C to ensure the experimental results.

[0019] Step 4: Place the assembled mold in the SPS furnace, set the pressure and temperature program for high-temperature heat treatment, and remove it after cooling;

[0020] The pressure program involves applying a pressure of 6–15 kN throughout the entire process;

[0021] The temperature program is as follows: heating to 1500-2000℃ in a vacuum environment at a heating rate of 100-200℃ / min, holding at that temperature for 5-90min, and cooling to room temperature at a cooling rate of 100-200℃ / min.

[0022] The heat preservation time is related to the quality of the silicon powder laid in step 3.

[0023] Step 5: Use a 300-mesh diamond grinding disc to grind and clean the graphite paper remaining on the upper and lower surfaces and around the sample to obtain a carbide ultra-high temperature ceramic-SiC gradient or uniform modified C / C composite material with controllable powder penetration depth.

[0024] The advantages of this invention are:

[0025] 1. This invention proposes a rapid preparation method for carbide ultra-high temperature ceramic-SiC gradient and uniformly modified C / C composite materials. A certain mass of silicide powder is uniformly spread on top of low-density C / C. Graphite paper is wrapped around the bottom of the low-density C / C and around the powder. The mold is placed above the lower punch of an SPS mold. Graphite paper of the same shape is placed on top of the powder, and finally, the upper punch is pressed in. The assembled mold is placed in an SPS furnace, and high-temperature heat treatment is performed by setting the heating and pressure programs. After polishing with a diamond grinding wheel, a carbide ultra-high temperature ceramic-SiC gradient modified C / C composite material with controllable powder penetration depth is obtained. When the open pore volume of the desired penetration area is equal to the open pore volume of the entire low-density C / C, a carbide ultra-high temperature ceramic-SiC uniformly modified C / C composite material is obtained.

[0026] 2. Existing matrix modification methods, such as precursor impregnation pyrolysis and chemical vapor infiltration, suffer from drawbacks such as long preparation cycles. Reactive melting infiltration is characterized by raw material waste and potential damage to carbon fibers, while slurry impregnation results in poor bonding between the ceramic phase and the matrix. This method, however, leverages the rapid heating advantage of SPS to reduce the flow erosion of the high-temperature melt, minimizing damage to the carbon fibers and preventing prolonged powder residence time at relatively low temperatures that could lead to silicon reacting first to form SiC, causing pore sealing and hindering further infiltration and reaction of the ultra-high temperature ceramic. Furthermore, the pressure applied by SPS ensures that the melted powder fully penetrates the matrix, preventing powder agglomeration and waste on the sample's exterior. Simultaneously, the pressure ensures a tight bond between the ceramic phase and the matrix.

[0027] 3. This method can control the powder penetration depth by controlling the total amount of powder laid on the matrix, SPS pressure and reaction temperature to prepare gradient and uniform modified C / C composite materials. The operation steps are simple and the preparation cycle is short. Modified C / C composite materials can be prepared in 1 to 2 hours. The reaction time is fast and the preparation cycle is short, making it suitable for large-scale and low-cost preparation of carbon-based / ceramic-based composite materials.

[0028] 4. This method saves powder and avoids the clumping and waste of excess powder accumulated on the outside of the matrix.

[0029] 5. This invention can control the powder penetration depth by controlling the total amount of powder laid on the matrix, SPS pressure and reaction temperature to prepare gradient and uniform modified C / C composite materials, which has strong controllability. Attached Figure Description

[0030] Figure 1 The following are schematic diagrams of the present invention: (a) schematic diagram of gradient modified C / C composite material; (b) schematic diagram of uniformly modified C / C composite material.

[0031] Figure 2 The microstructure of the gradient HfC-SiC-C / C composite material in Example 1 is shown in the following images: (a) XRD pattern of the sample surface; (b) SEM image of the sample cross section; (c) high-magnification SEM image of the sample cross section.

[0032] Figure 3 The microstructure of the gradient (Zr,Hf)C-SiC-C / C composite material in Example 2 is shown in the following images: (a) XRD pattern of the sample surface; (b) low-magnification SEM image of the sample cross section; (c,d) SEM image of the sample cross section.

[0033] Figure 4 The microstructure of the gradient (Zr,Hf)C-SiC-C / C composite material in Example 3 is shown in the following images: (a) XRD pattern of the sample surface; (b) low-magnification SEM image of the sample cross section; (c,d) SEM image of the sample cross section.

[0034] Figure 5 The microstructure of the uniform ZrC-SiC-C / C composite material in Example 4 is shown in the images: (a) a low-magnification SEM image of the sample cross-section; (b, c) SEM images of the sample cross-section. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Example 1

[0037] This embodiment discloses a rapid preparation method for a carbide ultra-high temperature ceramic-SiC gradient and uniformly modified C / C composite material, including the following steps:

[0038] Step 1: Use anhydrous ethanol for ultrasonic cleaning of a sample with dimensions of Φ28mm × 5mm and a density of 1.19g / cm³. 3The low-density C / C was dried in a far-infrared drying oven at 80℃ for 20 hours.

[0039] Step 2: Evenly spread 2.5g of HfSi2 powder on top of the low-density C / C, wrap the bottom of the low-density C / C and the area around the powder with graphite paper, place it above the lower punch of the SPS mold, place a piece of graphite paper with a size of Φ30mm on top of the powder, and finally press in the upper punch.

[0040] Step 3: Place the assembled mold in an SPS furnace, set the pressure to 7kN, heat it to 1750℃ in a vacuum environment at a heating rate of 200℃ / min, hold it at that temperature for 10min, and then cool it to room temperature at a cooling rate of 200℃ / min before removing it.

[0041] 4. The residual graphite paper on the upper and lower surfaces and around the sample was cleaned using a 300-mesh diamond grinding disc to obtain the HfC-SiC gradient modified C / C composite material, the microstructure of which is as follows: Figure 2 As shown, the ceramic phase inside the sample is tightly bonded to the matrix.

[0042] Example 2

[0043] This embodiment discloses a rapid preparation method for a carbide ultra-high temperature ceramic-SiC gradient and uniformly modified C / C composite material, including the following steps:

[0044] Step 1: Use anhydrous ethanol for ultrasonic cleaning of a sample with dimensions of Φ28mm × 5mm and a density of 1.14g / cm³. 3 The low-density C / C was dried in a far-infrared drying oven at 80℃ for 20 hours.

[0045] Step 2: Pour ZrSi2 and HfSi2 into a ball mill jar at a molar ratio of 1:1 and ball mill them using a planetary ball mill. The ball-to-material ratio is 2:1, the ball milling speed is 400 r / min, and after ball milling for 8 hours, place the silicide powder in a far-infrared drying oven at 70℃ and dry it for 15 hours.

[0046] Step 3: Evenly spread 2.5g of mixed ZrSi2 and HfSi2 powder on top of low-density C / C. Wrap the bottom of low-density C / C and the area around the powder with graphite paper. Place it above the lower punch of the SPS mold. Place a piece of graphite paper with a size of Φ30mm on top of the powder. Finally, press in the upper punch.

[0047] Step 4: Place the assembled mold in an SPS furnace, set the pressure to 8kN, heat it to 1800℃ in a vacuum environment at a heating rate of 200℃ / min, hold it at that temperature for 15min, and then cool it to room temperature at a cooling rate of 200℃ / min before removing it.

[0048] Step 5: Use a 300-mesh diamond grinding wheel to polish and clean the residual graphite paper on the upper and lower surfaces and around the sample, obtaining the (Zr,Hf)C-SiC gradient modified C / C composite material, the microstructure of which is as follows: Figure 3 As shown, from Figure 3 As can be seen in (b), the ceramic phase content decreases from top to bottom in the sample.

[0049] Example 3

[0050] This embodiment discloses a rapid preparation method for a carbide ultra-high temperature ceramic-SiC gradient and uniformly modified C / C composite material, including the following steps:

[0051] Step 1: Use anhydrous ethanol for ultrasonic cleaning of a sample with dimensions of Φ28mm × 5mm and a density of 1.17g / cm³. 3 The low-density C / C was dried in a far-infrared drying oven at 80℃ for 20 hours.

[0052] Step 2: Pour ZrSi2 and HfSi2 into a ball mill jar at a molar ratio of 3:1 and ball mill them using a planetary ball mill with a ball-to-material ratio of 2:1 and a ball milling speed of 400 r / min. After ball milling for 8 hours, place the silicide powder in a far-infrared drying oven at 70℃ and dry it for 15 hours.

[0053] Step 3: Evenly spread 2g of mixed ZrSi2 and HfSi2 powder on top of low-density C / C. Wrap the bottom of low-density C / C and the area around the powder with graphite paper. Place it above the lower punch of the SPS mold. Place a Φ30mm graphite paper on top of the powder. Finally, press in the upper punch.

[0054] Step 4: Place the assembled mold in an SPS furnace, set the pressure to 8.5 kN, heat it to 1750°C in a vacuum environment at a heating rate of 200°C / min, hold it at that temperature for 15 min, and then cool it to room temperature at a cooling rate of 200°C / min before removing it.

[0055] Step 5: Use a 300-mesh diamond grinding wheel to polish and clean the residual graphite paper on the upper and lower surfaces and around the sample, obtaining the (Zr,Hf)C-SiC gradient modified C / C composite material, the microstructure of which is as follows: Figure 4 As shown, from Figure 4 As can be seen in (b), the ceramic phase content decreases from top to bottom in the sample.

[0056] Example 4

[0057] This embodiment discloses a rapid preparation method for a carbide ultra-high temperature ceramic-SiC gradient and uniformly modified C / C composite material, including the following steps:

[0058] Step 1: Use anhydrous ethanol for ultrasonic cleaning of a sample with dimensions of Φ28mm × 5mm and a density of 1.10g / cm³. 3 The low-density C / C was dried in a far-infrared drying oven at 80℃ for 20 hours.

[0059] Step 2: Evenly spread 2.25g of ZrSi2 powder on the top and bottom of the low-density C / C, place it above the lower punch of the SPS mold, wrap the low-density C / C and powder with graphite paper, place a piece of graphite paper with a size of Φ30mm in the area where the powder contacts the upper and lower punches, and finally press in the upper punch.

[0060] Step 3: Place the assembled mold in an SPS furnace, set the pressure to 9kN, heat it to 1750℃ in a vacuum environment at a heating rate of 200℃ / min, hold it at that temperature for 30min, and then cool it to room temperature at a cooling rate of 200℃ / min before removing it.

[0061] Step 4: Use a 300-mesh diamond grinding wheel to polish and clean the residual graphite paper on the upper and lower surfaces and around the sample to obtain a ZrC-SiC uniformly modified C / C composite material, the microstructure of which is as follows. Figure 5 As shown, from Figure 5 (a) It can be seen that the ceramic phase is evenly distributed from top to bottom and is tightly bonded to the matrix.

[0062] The specific embodiments of the present invention have been described in detail above, but they are merely examples, and the present invention is not equivalent to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims

1. A method for rapid fabrication of carbide ultra-high temperature ceramic-SiC gradient and homogenously modified C / C composites, characterized in that, The method comprises the following steps: Step 1: Use anhydrous ethanol for ultrasonic cleaning of particles with a density of 0.9–1.4 g / cm³. 3 The low-density C / C composite material was dried in a far-infrared drying oven at 80-100℃ for 20-24 hours. Step 2: one or more of HfSi2, ZrSi2, TiSi2, TaSi2, NbSi2 powders are mixed in different proportions and then poured into a ball mill tank for ball milling by using a planetary ball mill to obtain silicide powder; Step 3: a certain mass of silicide powder is uniformly laid above the low-density C / C composite material, the bottom of the low-density C / C composite material and the periphery of the low-density C / C composite material and the powder are wrapped with graphite paper, the installed mold is placed above the lower punch of the SPS mold, an equal-shaped graphite paper is placed above the powder, and finally the upper punch is pressed; Step 4: the installed mold is placed in the SPS furnace, a pressure and temperature program is set for high-temperature heat treatment, and after cooling, the mold is taken out; Step 5: the graphite paper remaining on the upper and lower surfaces and the periphery of the sample is polished and cleaned by using a 300-mesh diamond grinding disc, and a silicide powder infiltrated carbide ultra-high-temperature ceramic-SiC gradient or uniformly modified C / C composite material with controllable powder infiltration depth is obtained; In the step 3, the mass of the silicide powder is calculated by the open pore volume of the infiltration area and the mixed density of the powder, when the open pore volume of the infiltration area is the open pore volume of the entire low-density C / C, a carbide ultra-high-temperature ceramic-SiC uniformly modified C / C composite material is obtained, and different ultra-high-temperature ceramic-SiC gradients and uniformly modified C / C composite materials are obtained by changing the laying method and mass of the powder; the pressure program of step 4 is to apply a pressure of 6-15 kN throughout the process.

2. The method according to claim 1, wherein the method is characterized in that: The ball milling time of step 2 is 8-12 h, and the ball milling speed is 400-600 r / min.

3. The method of claim 1, wherein the method further comprises: mixing the carbon precursor and the carbonization agent to form a mixture; and heating the mixture to form the carbonized material. The ball-milled powder in step 2 is dried in a far-infrared drying box at 50-100℃.

4. The method of claim 1, wherein the method further comprises the steps of: providing a carbon matrix; and infiltrating the carbon matrix with a silicon carbide precursor. The high-temperature heat treatment in step 4 is in a vacuum environment, the heating rate is 100-200 / min, the temperature is heated to 1500-2000℃, and the holding time is 5-90 min.

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