Preparation of C / C-SiC composite material and method by low-temperature reactive infiltration of silicon-nickel alloy

Abstract

The present invention discloses a method for preparing a C / C-SiC composite material by low-temperature reactive infiltration of a silicon-nickel alloy. The method comprises the following steps: uniformly pressing silicon powder and nickel powder into a mold by mechanical stirring and grinding; heating the pressed block to form a silicon-nickel alloy, and crushing the alloy block into alloy particles; laying a porous C / C composite material on top of the silicon-nickel alloy particles, and reactive infiltration in a vacuum furnace in a vacuum atmosphere or an Ar or N2 inert atmosphere to obtain a C / C-SiC composite material. The silicon-nickel alloy is used to address the limitations of the C / C-SiC composite material prepared by the pure silicon reactive infiltration process, such as low strength, high reactive infiltration temperature, and damage to fiber strength. The present invention has the advantages of significantly reducing the reactive infiltration process temperature, improving the uniformity of SiC phase distribution in the matrix, and improving the mechanical properties of the composite material, such as flexural strength and fracture toughness.

Description

Technical Field

[0001] The present invention relates to the field of composite materials, and in particular to a method for preparing a high-strength and high-toughness C / C-SiC composite material through low-temperature reactive infiltration of silicon-nickel alloy. Background Art

[0002] C / C-SiC composites are widely used in various industries due to their excellent properties, including good oxidation resistance, low density, and superior thermal stability. Reactive infiltration is a low-cost, net-size method for preparing C / C-SiC composites using pure silicon as a silicon source at high temperatures of 1500-1600°C. However, this traditional process has certain limitations. These include lower material strength compared to alternative methods such as chemical vapor deposition (CVI) and polymer infusion pyrolysis (PIP). The high temperature environment during reactive infiltration, along with the highly reactive liquid silicon or partial silicon vapor, can damage the carbon fiber surface structure and severely impair its mechanical properties. Furthermore, the brittleness and limited mechanical strength of pure silicon contribute to the poor performance of the composite. The low strength of the material limits its load-bearing capacity and range of applications. In addition, the traditional reactive infiltration process requires high temperatures, usually higher than the melting point of silicon (1414°C), to promote the penetration of silicon into the porous carbon matrix. High temperatures increase the risk of fiber degradation and damage during the reactive infiltration process, resulting in reduced original strength of the composite material and shortened fiber service life. The required high process temperature may bring challenges such as increased energy consumption and high requirements for equipment stability. The need for stable high temperature conditions and long processing times further limits the feasibility and scalability of the traditional reactive infiltration process.

[0003] In order to avoid the corrosion of carbon fibers by high-temperature silicon melt during reactive infiltration and reduce the content of free silicon in the composite material, the prior art CN116332663A introduces a silicon carbide / molybdenum carbide mixed powder during the weaving process of the carbon fiber preform, and uses the rough layer structure of pyrolytic carbon to form a tight interface with the carbon fibers to protect the carbon fibers from high-temperature corrosion by silicon. However, the improvement in the mechanical properties of the composite materials prepared by reactive infiltration is still limited, only about 20%. Although researchers have tried to lower the reactive infiltration temperature, Liu et al. introduced Al elements into the silicon source to reduce the preparation temperature to below 1400°C. However, the problem of insufficient reaction activity during the infiltration process caused the infiltration depth to be less than 1 mm. (Liu L, Zhang L, Feng W, et al. Microstructure and properties of C / C–SiC composites prepared by reactive melt infiltration at low temperature in vacuum[J]. Ceramics International, 2020, 46(6): 8469-8472). The prior art CN116283325A addresses the above-mentioned problem by introducing acidic reactive molten salts (acidic silicon-based reactive molten salts and acidic aluminum-based reactive molten salts) into the carbon matrix. During the reaction infiltration, the molten salts melt and volatilize to break the carbon matrix and accumulate in the infiltration pores, so that the Si-Al melt front containing iron salts (FeCl2 / FeCl3) forms a local low viscosity and low surface tension area, which participates in the transport of Al and Si in the reaction, and mixes with the broken and coarsened carbon pore walls and forms a low viscosity and low surface tension area in the FeCl2 / FeCl3 melt front. 2+ / Fe 3+ Reactive infiltration is achieved under the synergistic effect of catalytic graphitization to produce C / C-SiC composites. However, the molten salt and composite powder processes required in this technology are complicated, with a long cycle and high cost. In addition, the mechanical properties of the composite materials prepared by this reactive infiltration process are still unsatisfactory and cannot achieve the same mechanical properties as those of CVI or PIP technologies.

[0004] In the field of composite materials, the traditional method of preparing C / C-SiC composites by reactive infiltration of pure silicon has limitations in terms of mechanical properties. Compared with alternative methods such as chemical vapor deposition (CVI) or polymer infusion pyrolysis (PIP), the strength of the composites obtained by the traditional reactive infiltration process using pure silicon is relatively low. The main limitation of the traditional process is the use of pure silicon as the silicon source for generating the SiC matrix. The silicon phase remaining in the composite material after reactive infiltration often exhibits brittleness, resulting in low toughness of the composite material, which greatly limits the application potential of composite materials in high-strength environments. At the same time, the high melting point of pure silicon leads to high energy consumption, long cycle time and high cost of the traditional reactive infiltration process. In addition, the excessively high infiltration temperature itself will damage the reinforcement effect of the fiber.

[0005] In order to overcome the above-mentioned limitations of low strength and high process temperature of materials prepared by pure silicon reactive infiltration, a specific proportion of silicon-nickel alloy was introduced for reactive infiltration, which provides a potential process route for traditional methods. The development of high-strength C / C-SiC composite materials with enhanced performance and wider applicability is a technical problem that needs to be solved urgently. Summary of the Invention

[0006] In order to solve the above-mentioned defects in the prior art, the purpose of the present invention is to provide a method for preparing C / C-SiC composite materials by low-temperature reactive infiltration of silicon-nickel alloy. The silicon-nickel alloy reacts with the carbon matrix in the porous C / C composite material at the reactive infiltration temperature to form silicon carbide (SiC) phase and alloy phase (NiSi2 and NiSi). The resulting composite material has excellent mechanical properties and greatly improved flexural strength and fracture toughness.

[0007] The present invention is achieved through the following technical solutions.

[0008] According to one aspect of the present invention, a method for preparing a C / C-SiC composite material by a silicon-nickel alloy low-temperature reactive infiltration method is provided, comprising:

[0009] Silicon powder and nickel powder are mechanically stirred and ground into a uniform mass ratio of (32-49): (51-68);

[0010] Pressing the mixed powder into a shape;

[0011] heating the pressed block to form a silicon-nickel alloy, and crushing the alloy block into alloy particles;

[0012] The porous C / C composite material is spread on the silicon-nickel alloy particles in a mass ratio of 1: (1.5-3), and the reaction infiltration is carried out at a temperature of 1150-1400 ° C in a vacuum furnace with a vacuum atmosphere of vacuum, Ar or N2 for 30-40 minutes. After cooling, the C / C-SiC composite material is obtained.

[0013] Preferably, the particle sizes of silicon powder and nickel powder in the silicon-nickel alloy are similar, and raw material powder of 5-8 μm is selected.

[0014] Preferably, the mixed powder is pressed at a pressure of 45-60 MPa to form a sample block.

[0015] Preferably, the porous C / C composite material is 2.5D needle-punched carbon fiber felt, chopped carbon fiber felt or stitched 2D carbon fiber cloth.

[0016] Preferably, the sample block is placed in a vacuum furnace and heated to 1050-1400° C. for 30-60 minutes.

[0017] Preferably, the porous C / C composite material and silicon-nickel alloy particles are placed in a graphite crucible, the vacuum degree of the reactive infiltration is 20-50 Pa, and the inert atmosphere is Ar or N2.

[0018] Preferably, the heating rate of the reactive infiltration does not exceed 10°C / min, and the cooling rate does not exceed 20°C / min.

[0019] According to another aspect of the present invention, a C / C-SiC composite material prepared by the method is provided.

[0020] The phase composition of the C / C-SiC composite material prepared by the invention consists of C, SiC, NiSi2 and NiSi, and the phase composition of the C / C-SiC composite material consists of C, SiC, NiSi2 and NiSi.

[0021] The present invention adopts the above technical solution, which has the following beneficial effects:

[0022] 1. This invention uses a silicon-nickel alloy to address the low strength of C / C-SiC composites prepared by pure silicon reactive infiltration (RMI), as well as the limitations of traditional reactive infiltration, such as high temperatures and fiber strength damage. Using a silicon-nickel alloy for infiltration, the material's open porosity and mechanical properties fluctuate minimally with varying holding temperatures (1150-1400°C), indicating a low dependence on temperature parameters. The holding temperature can be flexibly adjusted in actual production, reducing the need for temperature restrictions in actual production.

[0023] 2. The reactivity of silicon-nickel alloy with carbon fiber is lower than that of pure silicon, which can retain more carbon fiber reinforcement phase in the composite material. By introducing a specific proportion of silicon-nickel alloy during the reactive infiltration process, a high-density, high-strength C / C-SiC composite material with an open porosity below 4% and a strength of up to 400 MPa can be obtained by holding the material at low temperature (less than 1414°C) for a short time (30 minutes).

[0024] 3. This method can improve the mechanical properties of composite materials, making them reach or even exceed the performance indicators of CVI and PIP processes, while significantly reducing the temperature requirements for reactive infiltration. The reduction in process temperature effectively shortens the production cycle, improves industrial production efficiency, and better controls the infiltration process.

[0025] The invented C / C-SiC composite material can be used in aerospace, automobile, energy and other fields that require the preparation and application of high-performance composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute an improper limitation of the present invention. In the drawings:

[0027] Figure 1 1 is the XRD pattern of the C / C-SiC composite material prepared in Example 1 and the C / C-SiC composite material prepared in Comparative Example 1;

[0028] Figure 2 (a) and (b) are backscattered electron morphology photographs of the C / C-SiC composite material prepared in Example 1: (a) 50×, (b) 500×;

[0029] Figure 3 (a) and (b) are microscopic images of fiber damage of the C / C-SiC composite material prepared in Comparative Example 1 and the C / C-SiC composite material prepared in Example 1, respectively;

[0030] Figures 4 (a) and (b) are backscattered electron morphology photographs of different positions of the C / C-SiC composite material prepared in Comparative Example 2. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The exemplary embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0032] The embodiment of the present invention provides a method for preparing a C / C-SiC composite material by a silicon-nickel alloy low-temperature reactive infiltration method, comprising the following steps:

[0033] 1) Alloy preparation:

[0034] The powder mixture of 5-8 μm silicon powder and nickel powder is physically mixed by mechanical stirring in a mass ratio of (32-49): (51-68), and then ground and mixed thoroughly to ensure uniform distribution and enhance alloying. The silicon-nickel alloy has similar particle sizes of silicon powder and nickel powder, and the composition must be uniform and free of impurities.

[0035] The mixed powder was then placed in a mold and pressed into a sample block at a pressure of 45-60 MPa to obtain a sample block with a diameter of 30 mm;

[0036] The pressed block is placed in a vacuum furnace and heated to 1050-1400°C, and kept warm for 30-60min to melt the sample block and react to form a silicon-nickel alloy, and the alloy block is broken into alloy particles.

[0037] 2) Select porous C / C composite materials:

[0038] This method uses a density of 1.30 g / cm 3 2.5D needle-punched carbon fiber felt reinforced C / C composite material. It should be noted that the present invention can select a porous C / C composite material with corresponding characteristics according to actual needs. For example, low-cost chopped carbon fiber felt can be preferred. If there are certain requirements for both densification effect and isotropic strength, a moderately cost-effective 2.5D needle-punched laminated carbon fiber felt can be selected. If high densification technology requirements and high strength in the fabric direction are required, a high-cost stitched 2D carbon fiber cloth can be selected as the reinforcement.

[0039] 3) Low temperature reactive infiltration process:

[0040] Silicon-nickel alloy particles were placed in a graphite crucible containing graphite paper. A porous carbon / carbon composite was placed on top of the alloy particles. The mass of the silicon-nickel alloy particles was (1.5-3) times that of the porous carbon / carbon composite. The graphite crucible was placed in a controlled atmosphere vacuum furnace. The vacuum was evacuated to 10 Pa and the temperature was raised to 1050-1400°C. The temperature was maintained for 30-60 minutes. The heating rate did not exceed 10°C / min, and the cooling rate did not exceed 20°C / min.

[0041] In this step, under a vacuum of 20-50 Pa and an inert atmosphere of Ar or N₂, the silicon-nickel alloy particles melt and penetrate the pores of the porous C / C composite structure through capillary action, ensuring sufficient time for the reaction process to occur fully and evenly. The molten alloy reacts with the carbon matrix, forming silicon carbide (SiC) through a chemical reaction between silicon and carbon.

[0042] The use of silicon-nickel alloys enables the infiltration process at relatively low temperatures (below 1400°C). Experimental results show that holding at around 1390°C for 40 minutes achieves optimal results. During the infiltration process, the silicon-nickel alloy chemically reacts with the carbon source within the porous C / C composite, fully incorporating the alloy into the infiltration reaction process. This allows the SiC and alloy phases to be evenly distributed within the material, resulting in the formation of SiC and alloy phases uniformly distributed within the carbon matrix. This uniform distribution of these phases contributes to improved mechanical properties, including flexural strength and fracture toughness. The reduced process temperature significantly reduces damage to the fiber-reinforced phase caused by high temperatures, preserving the original strength of the fibers in the composite and contributing to improved mechanical properties, including flexural strength and fracture toughness.

[0043] The phase composition of the C / C-SiC composite material is composed of C, SiC, NiSi2, and NiSi. The density of the C / C-SiC composite material obtained in the temperature range of 1150 ℃~1390 ℃ is 2.28~2.50 g / cm 3 The open porosity is below 4.0%, the bending strength of the material can reach up to 409.1 MPa, and the fracture toughness can reach up to 9.64 MPa·m 1 / 2 .

[0044] The present invention is further described below through different embodiments.

[0045] Example 1:

[0046] 1) Alloy Preparation: Silicon-nickel alloy is prepared by weighing and mixing 5-8 μm silicon powder and nickel powder in a mass ratio of 49:51. The mixed powder is then pressed into shape under a pressure of 45 MPa and held at 1400°C for 40 min. It is then vacuum sintered to obtain a solid alloy block. The alloy is then removed and crushed to obtain millimeter-sized alloy particles.

[0047] 2) Porous C / C composite material: This method uses a density of 1.30 g / cm 3 2.5D needle-punched carbon fiber felt reinforced C / C composite material.

[0048] 3) Low-temperature reactive infiltration process: Si-Ni alloy particles are placed in a graphite crucible containing graphite paper. A porous C / C composite material is placed on top of the alloy particles, with the alloy mass being twice that of the porous C / C composite material. The graphite crucible is then placed in a controlled atmosphere vacuum furnace. The furnace is evacuated to 10 Pa and then heated at a rate of approximately 8°C / min. The furnace is heated to 1150°C and held at 1390°C for this example. The temperature is maintained for a predetermined duration, typically greater than 30 minutes. In this example, the holding time is 40 minutes, with a cooling rate of 15°C / min. Under vacuum conditions of 20 Pa and an Ar atmosphere, the molten alloy reacts with the carbon matrix, and the temperature is then cooled to produce a C / C-SiC composite material.

[0049] The density of the C / C-SiC composite material prepared by this process is 2.33 g / cm 3 The open porosity is 3.30%. The material is composed of four phases: C, SiC, NiSi2, and NiSi. Each phase is evenly distributed. The flexural strength is 409.1 MPa and the fracture toughness is 9.6 MPa·m 1 / 2 The obtained products were characterized by X-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM). Figure 1 The XRD spectrum of the product shows that the main components of the product are SiC, C, NiSi2, and NiSi. Figures 2 (a) and (b) show the backscattered electron morphology of the product at different magnifications. It can be seen that under this temperature condition, the silicon-nickel alloy can fully penetrate into the porous C / C composite material and uniformly generate the SiC phase. It can be clearly seen that the black area is the carbon phase, the white area is the alloy phase, and the gray area is the silicon carbide phase. The white alloy phase is composed of NiSi2 and NiSi phases. At the same time, Figure 3 (b) shows that almost no carbon fiber is consumed by Si to generate SiC, which greatly retains the strength and reinforcement properties of the fiber, making the composite material prepared by this process have excellent performance.

[0050] Example 2:

[0051] 1) Alloy Preparation: Silicon-nickel alloy is prepared by weighing and mixing 5-8 μm silicon powder and nickel powder in a mass ratio of 40:60. The mixed powder is then pressed into a shape under a pressure of 50 MPa and held at 1150°C for 30 min. It is then vacuum sintered to obtain a solid alloy block. The alloy is then removed and crushed to obtain millimeter-sized alloy particles.

[0052] 2) Porous C / C composite material: This method uses chopped carbon fiber felt.

[0053] 3) Low-temperature reactive infiltration process: Si-Ni alloy particles are placed in a graphite crucible containing graphite paper. A porous C / C composite material is placed on top of the alloy particles, with the alloy mass being 1.5 times that of the porous C / C composite material. The graphite crucible is then placed in a controlled atmosphere vacuum furnace. The furnace is evacuated to a vacuum of 10 Pa and then heated at a rate of approximately 9°C / min. The furnace is heated to 1050°C and held at 1350°C for this example. The temperature is maintained for a predetermined duration, typically greater than 30 minutes. In this example, the holding time is 50 minutes, with a cooling rate of 18°C / min. Under a vacuum of 40 Pa and an N2 atmosphere, the molten alloy reacts with the carbon matrix, and the C / C-SiC composite material is obtained after cooling.

[0054] The density of the C / C-SiC composite material prepared by this process is 2.28 g / cm 3 The open porosity is 2.50%. The material is composed of four phases: C, SiC, NiSi2, and NiSi. Each phase is evenly distributed. The flexural strength is 335.5 MPa and the fracture toughness is 8.5 MPa·m 1 / 2 The other results are the same as those in Example 1.

[0055] Example 3:

[0056] 1) Alloy Preparation: Silicon-nickel alloy is prepared by weighing and mixing 5-8 μm silicon powder and nickel powder in a mass ratio of 45:55. The mixed powder is then pressed into shape under a pressure of 55 MPa and held at 1050°C for 60 min. It is then vacuum sintered to obtain a solid alloy block. The alloy is then removed and crushed to obtain millimeter-sized alloy particles.

[0057] 2) Porous C / C composite material: This method uses 2.5D needle-punched laminated carbon fiber felt.

[0058] 3) Low-temperature reactive infiltration process: Si-Ni alloy particles are placed in a graphite crucible containing graphite paper. A porous C / C composite material is placed on top of the alloy particles, with the alloy mass being 2.5 times that of the porous C / C composite material. The graphite crucible is then placed in a controlled atmosphere vacuum furnace. The furnace is evacuated to 10 Pa and then heated at a rate of approximately 7°C / min to 1250°C. For this example, the holding temperature is 1310°C. The temperature is maintained for a predetermined duration of 60 minutes, with a cooling rate of 15°C / min. Under vacuum conditions of 50 Pa and an Ar atmosphere, the molten alloy reacts with the carbon matrix, and the C / C-SiC composite material is obtained after cooling.

[0059] The density of the C / C-SiC composite material prepared by this process is 2.33 g / cm 3The open porosity is 2.73%. The material is composed of four phases: C, SiC, NiSi2, and NiSi. Each phase is evenly distributed. The flexural strength is 378.9 MPa and the fracture toughness is 8.7 MPa·m 1 / 2 The other results are the same as those in Example 1.

[0060] Example 4:

[0061] 1) Alloy Preparation: Silicon-nickel alloy is prepared by weighing and mixing 5-8 μm silicon powder and nickel powder in a mass ratio of 32:68. The mixed powder is then pressed into shape under a pressure of 60 MPa and held at 1250°C for 40 min. It is then vacuum sintered to obtain a solid alloy block. The alloy is then removed and crushed to obtain millimeter-sized alloy particles.

[0062] 2) Porous C / C composite material: This method uses stitched 2D carbon fiber cloth.

[0063] 3) Low-temperature reactive infiltration process: Si-Ni alloy particles are placed in a graphite crucible containing graphite paper. A porous C / C composite material is placed on top of the alloy particles, with the alloy mass being three times that of the porous C / C composite material. The graphite crucible is then placed in a controlled atmosphere vacuum furnace. The furnace is evacuated to a vacuum of 10 Pa and then heated at a rate of approximately 8°C / min to 1050°C. For this example, the holding temperature is 1270°C. The temperature is maintained for a predetermined duration of 30 minutes, with a cooling rate of 12°C / min. Under vacuum conditions of 30 Pa and an Ar atmosphere, the molten alloy reacts with the carbon matrix, and the C / C-SiC composite material is obtained after cooling.

[0064] The density of the C / C-SiC composite material prepared by this process is 2.50 g / cm 3 The open porosity is 2.70%. The material is composed of four phases: C, SiC, NiSi2, and NiSi. Each phase is evenly distributed. The flexural strength is 307.9 MPa and the fracture toughness is 7.4 MPa·m 1 / 2 The other results are the same as those in Example 1.

[0065] The following comparative examples are given to further illustrate the preparation method of the present invention.

[0066] Comparative Example 1

[0067] The porous C / C composite material was directly treated with pure silicon by conventional reactive infiltration process. The infiltration temperature was 1500℃ and the holding time was 40min. From the XRD pattern of the product, the final composite material was composed of C, SiC and Si with a density of 2.21g / cm 3 , open porosity is 2.62%, flexural strength is 164.1 MPa, fracture toughness is 2.1 MPa·m1 / 2 From Figure 3 (a), we can see that a large amount of carbon fibers are consumed by Si and react to form SiC, which greatly reduces the mechanical properties of the material.

[0068] Comparative Example 2

[0069] Pure silicon was directly used in a conventional reactive infiltration process on a porous C / C composite at 1350°C for 40 minutes. Figures 4(a) and (b) confirm that the resulting material contains no SiC and is entirely C phase. Figures 4(a) and (b) show that under the same temperature conditions (1350°C), pure silicon is unable to penetrate the porous C / C composite, and no reaction occurs to form SiC.

[0070] The performance test results of the examples of the present application and the comparative examples are compared in Table 1.

[0071] Table 1 Performance comparison

[0072]

[0073] As can be seen from Table 1, the present invention prepares a dense, high-strength, and high-toughness C / C-SiC composite material, the density of which is not less than 2.28 g / cm2 relative to the comparative example. 3 , open porosity not higher than 3.30%, flexural strength not lower than 307.9 MPa, fracture toughness not lower than 7.4 MPa∙m 1 / 2 It can be seen that the C / C-SiC composite material prepared by the present invention not only has a low open porosity, but also has very excellent mechanical properties and fracture toughness. This process is low-cost and has a short cycle. It is a new process that can generate certain economic benefits and has a wide range of application scenarios.

[0074] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some of the technical features therein according to the disclosed technical content without creative labor, and these substitutions and modifications are all within the protection scope of the present invention.

Claims

1. A method for preparing C / C-SiC composite material by low-temperature reactive infiltration of silicon-nickel alloy, characterized in that: include: Silicon powder and nickel powder are mechanically stirred and ground into a uniform mass ratio of (32-49): (51-68); The mixed powder was pressed into a sample block at a pressure of 45-60 MPa; The pressed block is placed in a vacuum furnace and heated to 1050-1400°C, and kept warm for 30-60min to melt the sample block to form a silicon-nickel alloy, and the alloy block is crushed into alloy particles; The porous C / C composite material is spread on the silicon-nickel alloy particles in a mass ratio of 1:(1.5-3). The reaction infiltration is carried out in a vacuum furnace with a vacuum degree of 20-50 Pa and a temperature of 1150-1400 ° C for 30-40 minutes. The reaction infiltration heating rate does not exceed 10 ° C / min, and the cooling rate does not exceed 20 ° C / min. After cooling, a C / C-SiC composite material is obtained.

2. The method for preparing a C / C-SiC composite material according to claim 1, wherein: The particle sizes of silicon powder and nickel powder in silicon-nickel alloy are similar, and raw material powder of 5-8 μm is selected.

3. The method for preparing a C / C-SiC composite material according to claim 1, characterized in that: The porous C / C composite material is 2.5D needle-punched carbon fiber mat, chopped carbon fiber mat or stitched 2D carbon fiber cloth.

4. The method for preparing a C / C-SiC composite material according to claim 1, wherein: The porous C / C composite material and silicon-nickel alloy particles were placed in a graphite crucible for reaction infiltration.

5. A C / C-SiC composite material prepared by the method according to any one of claims 1 to 4.

6. The C / C-SiC composite material according to claim 5, characterized in that The phase composition of C / C-SiC composite material is composed of C, SiC, NiSi2 and NiSi, and the density is not less than 2.28g / cm 3 , the open porosity is below 4.0%, the flexural strength is not less than 409.1 MPa, and the fracture toughness is not less than 7.4 MPa·m 1 / 2 .

7. Application of the C / C-SiC composite material according to claim 6 in the fields of aerospace, automobile and energy.

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