C / SiC-Al composite material and preparation method thereof
By combining ceramic matrix composites with Al alloys and employing organic precursor impregnation-pyrolysis and metal infiltration processes, a lightweight and tough C/SiC-Al composite material was prepared. This solved the brittleness problem of C/SiC composite materials during processing and achieved efficient densification and cost reduction.
Patent Information
- Application Number
- CN202511498945.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-20
- Publication Date
- 2026-02-17
AI Technical Summary
Existing C/SiC composite matrix is brittle, especially for C/SiC composites with insufficient densification, which are prone to damage during processing such as sharp corners and edges, making it difficult to guarantee local integrity.
By combining ceramic matrix composites with Al alloys, and preparing semi-dense C/SiC composites through an organic precursor impregnation-pyrolysis process, aluminum alloys are introduced using a high-temperature metal infiltration process to achieve the preparation of lightweight and tough C/SiC-Al composites.
It improves the toughness and processability of C/SiC composite materials, broadens their application range, meets the graded and classified use requirements of ceramic matrix composite materials for high-speed aircraft, and reduces the preparation cost and cycle.
Smart Images
Figure CN121535162A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of composite material technology and relates to a method for preparing a continuous carbon fiber reinforced silicon carbide matrix composite material by using aluminum or its alloy. Background Technology
[0002] Carbon / silicon carbide (C / SiC) composites possess excellent properties such as high specific strength, strong designability, high temperature resistance, and oxidation resistance, making them an irreplaceable thermal structural composite material in the aerospace field. Among the preparation methods of continuous fiber reinforced ceramic matrix composites, the precursor impregnation pyrolysis (PIP) process has become the main method for C / SiC composite preparation due to its good processability. However, due to the hard and brittle nature of ceramic matrix composites, especially for C / SiC composites with insufficient densification, damage easily occurs during processing such as sharp corners and edges, making it difficult to guarantee local integrity. C / SiC composites prepared by the PIP process still retain porous characteristics, and the overall structural reliability still needs to be improved.
[0003] Metallic materials possess excellent toughness and high processing precision. Among them, aluminum and its alloys are the most widely studied materials in metal matrix composites, with carbon fiber reinforced aluminum matrix composites (C...) being a prime example. f The specific strength of Al is 667 MPa·cm. 3 Its density is 6 times that of steel and 3 to 3.5 times that of titanium alloys and aluminum alloys. Its specific modulus reaches 110 GPa·cm⁻¹. 3 / g, which is more than 3 times that of steel, aluminum alloys, and titanium alloys, C f / Al, with its excellent lightweight and high strength properties, provides important technical support for the lightweight, high precision and high reliability of aerospace structures. However, due to the limitations of the preparation process, this composite material cannot be mass-produced and made in large sizes.
[0004] Current matrix modification techniques for C / SiC composites primarily focus on effectively combining multifunctional integrated design with low-temperature, high-efficiency densification processes. These techniques utilize ultra-high-temperature ceramics, multi-element alloys, and novel reinforcement methods to enhance the overall performance of C / SiC composites. However, traditional refractory metals and their alloys, with their high density and thermal conductivity, are typically prepared through reactive melting at high temperatures (>2000℃), leading to carbon fiber damage and failing to meet the requirements for lightweight applications. Summary of the Invention
[0005] The technical problem solved by this application is to overcome the shortcomings of the prior art and provide a method for preparing C / SiC-Al composite materials, thereby improving the toughness of C / SiC composite materials and broadening their further applications and development. It solves the problem that "existing C / SiC composite matrix is brittle, especially for C / SiC composite materials with insufficient densification, which are prone to damage during processing such as sharp corners and edges, making it difficult to guarantee local integrity."
[0006] Specifically, this application combines ceramic matrix composites with Al alloys to achieve complementary performance advantages, making them widely applicable structural materials that meet the graded and classified use requirements of ceramic matrix composites for high-speed aircraft.
[0007] The technical solution provided in this application is as follows:
[0008] In a first aspect, a method for preparing C / SiC-Al composite materials is provided, comprising:
[0009] After preparing a semi-dense C / SiC composite material using an organic precursor impregnation-pyrolysis process, an aluminum alloy is uniformly introduced into the C / SiC composite material using a high-temperature metal infiltration process to obtain a C / SiC-Al composite material with excellent mechanical properties, thus realizing the rapid preparation of lightweight and tough ceramic / metal hybrid matrix composite materials.
[0010] In one possible implementation, the organic precursor impregnation-pyrolysis process yields a product with a density of 1.1–1.7 g / cm³. 3 C / SiC composite materials with a porosity of 15-50%, including:
[0011] Carbon fiber fabric is woven with reinforcement.
[0012] Carbon fiber fabric is placed in a chemical vapor deposition furnace for pyrolytic carbon deposition to obtain interfacial deposited fabric.
[0013] For interfacial deposited fabrics, liquid-phase special ceramic precursors are used as impregnating agents, and C / SiC composite materials are obtained through 2 to 6 cycles of organic precursor impregnation-pyrolysis process.
[0014] By repeating the organic precursor impregnation-pyrolysis process in multiple cycles, the density of the obtained C / SiC composite material was ensured to be between 1.1 and 1.7 g / cm³. 3 And the porosity is in the range of 15% to 50%.
[0015] In one feasible approach, the reinforcement is made of domestically produced carbon fiber, and the fabric structure is a fine-knitted, orthogonal triaxial, needle-punched structure, with the fabric thickness ranging from 5mm to 10mm.
[0016] In one feasible method, the deposition time of pyrolytic carbon deposition is 150h to 400h, and the thickness of the pyrolytic carbon layer formed is in the range of 0.5 to 2μm.
[0017] In one possible implementation, one round of the organic precursor impregnation-pyrolysis process includes: sequentially impregnating, curing, and pyrolyzing the fabric after interfacial deposition using a liquid-phase special ceramic precursor.
[0018] In one possible implementation, the impregnation pressure is 0.1–8 MPa, the impregnation time is 1–5 hours, and the impregnation temperature is 20–150°C.
[0019] In one possible implementation, the curing temperature is between 120 and 450°C, and the curing time is between 1 and 10 hours.
[0020] In one possible implementation, the pyrolysis temperature is between 900 and 1500°C, and the pyrolysis time is between 3 and 15 hours.
[0021] By controlling the pyrolysis temperature and the number of impregnation cycles, the porosity can be adjusted, ensuring that the C / SiC-Al composite material has good overall mechanical properties. When the initial porosity is too high or too low, it affects the mechanical properties of the C / SiC-Al composite material.
[0022] In one feasible embodiment, the densification degree of the medium-density C / SiC composite material can be adjusted during the preparation process using composite batches, according to the performance requirements of the C / SiC-Al composite material. The porosity of the C / SiC composite material ranges from 15% to 50%, and the density is 1.1 to 1.7 g / cm³. 3 .
[0023] In one possible implementation, the metal used in the high-temperature metal infiltration process is pure aluminum or aluminum alloy, the infiltration temperature is 500-1000℃, and the uniform introduction of the metal is achieved by using processes such as vacuum-pressurization and vacuum-pressurization alternation according to the wettability of the metal with C / SiC.
[0024] In one feasible approach, by adjusting the types of metals in the matrix and the relative content of the metals to SiC, the differentiated requirements of material load-bearing and heat protection for different application environments can be met.
[0025] Secondly, a method for preparing C / SiC-Al composite materials is provided, including the following steps:
[0026] 1) Reinforcing carbon fiber fabric weaving. Based on the characteristics of composite material preparation, the carbon fiber fabric structure can adopt fine weaving, orthogonal triaxial, needle punching and other structural forms, with the fabric thickness dimension ranging from 5 to 10 mm.
[0027] 2) Carbon fiber interface preparation. A chemical vapor deposition (CVD) method was used, in which carbon fiber fabric was placed in a CVD furnace for pyrolytic carbon deposition. The deposition time was 100-300 hours, resulting in a pyrolytic carbon layer with a thickness ranging from 0.5 to 2 μm, thus obtaining the interface-deposited fabric. Carbon readily reacts with metals, forming brittle metal carbides that create strong interfacial bonds, reducing the performance of the composite material.
[0028] 3) Densification of the ceramic matrix. After obtaining the interfacial deposited fabric, a liquid-phase special ceramic precursor, such as a liquid polycarbosilane precursor or an organic solution containing polycarbosilane, is used as an impregnating agent. Through 2–6 cycles of organic precursor impregnation-pyrolysis process, the matrix components of the composite material are semi-densified to obtain a density of 1.1–1.7 g / cm³. 3 C / SiC composite materials with a certain degree of porosity.
[0029] The C / SiC composite material is prepared by an organic precursor impregnation-pyrolysis process. The special precursor used has a curing temperature between 120 and 450°C and a curing time between 1 and 10 hours.
[0030] The cured C / SiC composite material needs to undergo high-temperature pyrolysis, with a pyrolysis temperature between 900 and 1500°C and a pyrolysis time of 3 to 15 hours.
[0031] 4) Densification of the metal matrix. Based on the preparation of C / SiC composite materials with through channels inside the material using the organic precursor impregnation-pyrolysis process (i.e., PIP method), the metal phase of aluminum and its alloys is introduced into the pores of the C / SiC composite material by melt infiltration at a temperature above its melting point through vacuum, pressure or a combination of both, to achieve rapid densification.
[0032] For C / SiC composites prepared using the PIP process, the elongated pores generated inside the material provide a natural channel for introducing molten aluminum and its alloys using the melt infiltration process. By combining C / SiC composites with lightweight, low-melting-point Al alloys and utilizing a combined PIP and melt infiltration process, a C / SiC-Al composite material can be developed that combines the high strength, high temperature resistance, and low coefficient of thermal expansion of ceramic matrix composites with the toughness and excellent processing characteristics of metallic materials. This will provide technical support for the toughening and rapid densification of C / SiC composites, and will further develop ceramic matrix composites to meet the weight reduction and high load-bearing requirements of various aerospace vehicles for thermal structural materials.
[0033] The advantages of this invention compared to the prior art include:
[0034] (1) This invention combines PIP (organic precursor impregnation-pyrolysis process) with metal infiltration, and uses their respective advantages to complement each other. Low-density C / SiC composite material is obtained by using PIP, and metal infiltration is used as a preform to achieve rapid densification of composite material, which significantly reduces the preparation cycle. There is no chemical reaction in the preparation process, the preparation process is controllable, and the obtained product has stable performance.
[0035] (2) The C / SiC-Al composite material prepared by the present invention has the performance characteristics of both ceramic materials and metal aluminum, with high strength, modulus and high temperature resistance as well as good ductility and low coefficient of thermal expansion. Due to the addition of metal aluminum, the processability of the composite material is greatly improved.
[0036] (3) Based on reducing the number of densification cycles of the ceramic matrix, the present invention further uses lower-cost metallic aluminum or its alloys to complete the final densification, which can greatly reduce the material preparation cost compared with traditional ceramic matrix composites.
[0037] (4) The C / SiC-Al composite material prepared by the present invention has a high degree of densification, a porosity of ≤5%, and a room temperature comprehensive mechanical property that is better than that of C / SiC. Its temperature resistance level is between that of metal matrix and C / SiC, which can meet the graded and classified use requirements of ceramic matrix composite materials.
[0038] (5) The relative content of ceramic and metal components in the matrix of the C / SiC-Al composite material prepared by the present invention can be controlled by the composite round of C / SiC material, and the melting and infiltration process can be carried out by using aluminum and its alloys to meet the different performance requirements of the material. Attached Figure Description
[0039] Figure 1 This is a schematic diagram of the preparation process for C / SiC-Al composite materials. Detailed Implementation
[0040] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments disclosed in this application will be described in further detail below with reference to the accompanying drawings.
[0041] All raw materials used in the embodiments are commercially available products.
[0042] Example 1
[0043] This invention provides a method for preparing C / SiC-Al composite materials, such as... Figure 1 As shown, it includes the following steps:
[0044] 1) The fabric is made of domestically produced T300-3K carbon fiber woven needle-punched material with a fabric density of 0.75 g / cm³. 3The dimensions are 300*200*8mm, and the thickness dimension of the woven needle-punched fabric is 8mm.
[0045] 2) Place the fabric in a heat treatment furnace and heat it to 900°C under inert gas protection to remove the sizing agent from the fiber surface.
[0046] 3) The fabric after removing the sizing agent is placed in a chemical vapor deposition furnace for pyrolytic carbon deposition. The deposition time is 100 h and the temperature is 1400℃~2500℃, forming a pyrolytic carbon layer with a thickness of 150 μm.
[0047] 4) The deposited fabric is placed in a tooling fixture, and a liquid polycarbosilane precursor is impregnated using vacuum-pressure impregnation. The precursor is immersed into the fabric at a pressure of 1.0 MPa, and cured at 0.5 MPa and 250°C for 5 hours. Then, it is pyrolyzed by treating it at 900°C in a high-temperature furnace for 4 hours. The above organic precursor impregnation-pyrolysis process is repeated a total of 4 times to obtain a density of 1.70 g / cm³. 3 A C / SiC composite material with a porosity of 35%.
[0048] 5) The C / SiC composite material was loaded into a graphite fixture, and aluminum-silicon alloy powder was used to embed the C / SiC. Melting and infiltration were performed under vacuum conditions at 800℃ to obtain a density of 2.0 g / cm³. 3 C / SiC-Al composite material with a porosity of 4.5%.
[0049] 6) Samples were taken from the upper and lower surfaces of the material to obtain the following mechanical properties: tensile strength 282 MPa, compressive strength 430 MPa, flexural strength 405 MPa, and fracture toughness 18.7 MPa·m. 1 / 2 .
[0050] Example 2
[0051] This invention provides a method for preparing C / SiC-Al composite materials, comprising the following steps:
[0052] 1) The fabric is a fine-knitted puncture-type fabric woven with domestically produced T300-3K carbon fiber, with a fabric density of 0.85 g / cm³. 3 The dimensions are 300*200*10mm, and the thickness dimension of the woven needle-punched fabric is 10mm.
[0053] 2) Place the fabric in a heat treatment furnace and heat it to 900°C under inert gas protection to remove the sizing agent from the fiber surface.
[0054] 3) The fabric after removing the sizing agent is placed in a chemical vapor deposition furnace for pyrolytic carbon deposition. The deposition time is 120 h and the temperature is 1400℃~2500℃, forming a pyrolytic carbon layer with a thickness of 200 μm.
[0055] 4) The deposited fabric is placed in a tooling fixture, and a liquid polycarbosilane precursor is impregnated using vacuum-pressure impregnation. The precursor is immersed into the fabric at a pressure of 1.0 MPa, and cured at 0.5 MPa and 250°C for 5 hours. Then, it is pyrolyzed by treating it at 1000°C in a high-temperature furnace for 3 hours. The above organic precursor impregnation-pyrolysis process is repeated a total of 5 times to obtain a density of 1.80 g / cm³. 3 A C / SiC composite material with a porosity of 20%.
[0056] 5) The C / SiC composite material was loaded into a graphite fixture, and pure aluminum powder was used to embed the C / SiC. Pure aluminum infiltration was carried out under vacuum conditions at 800℃ to obtain a density of 2.05 g / cm³. 3 C / SiC-Al composite material with a porosity of 5%.
[0057] 6) Samples were taken from the upper and lower surfaces of the material to obtain the following mechanical properties: tensile strength 370 MPa, compressive strength 450 MPa, flexural strength 596 MPa, and fracture toughness 19 MPa·m. 1 / 2 .
[0058] Example 3
[0059] The only difference from Example 2 is that the organic precursor impregnation-pyrolysis process was carried out four times, with the product being treated at 1300°C for 3 hours in a high-temperature furnace.
[0060] A density of 1.7 g / cm³ was obtained. 3 A C / SiC composite material with a porosity of 40%.
[0061] Pure aluminum powder was used to embed C / SiC.
[0062] Samples were taken from the upper and lower surfaces of the obtained C / SiC-Al composite material, and the mechanical properties of the material were obtained as follows: tensile strength 302 MPa, compressive strength 381 Pa, flexural strength 365 MPa, and fracture toughness 21.2 MPa·m. 1 / 2 .
[0063] Example 4
[0064] The only difference from Example 2 is that the organic precursor impregnation-pyrolysis process was carried out 5 times in a high-temperature furnace at 1300°C for 3 hours.
[0065] A density of 1.8 g / cm³ was obtained. 3 A C / SiC composite material with a porosity of 30%.
[0066] Aluminum-silicon alloy powder was selected for C / SiC embedding.
[0067] Samples were taken from the upper and lower surfaces of the obtained C / SiC-Al composite material, and the mechanical properties of the material were obtained as follows: tensile strength 338 MPa, compressive strength 450 Pa, flexural strength 468 MPa, and fracture toughness 15.2 MPa·m. 1 / 2 .
[0068] The contents not described in detail in this application specification are common knowledge to those skilled in the art.
[0069] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.
Claims
1. A method for preparing a C / SiC-Al composite material, characterized in that, include: A product with a density of 1.1–1.7 g / cm³ was prepared using an organic precursor impregnation-pyrolysis process. 3 C / SiC composite materials with a porosity of 15-50% are obtained by introducing pure aluminum or aluminum alloy into the C / SiC composite material using a metal infiltration process, thus obtaining C / SiC-Al composite material.
2. The method for preparing a C / SiC-Al composite material according to claim 1, characterized in that: The organic precursor impregnation-pyrolysis process yielded a product with a density of 1.1–1.7 g / cm³. 3 C / SiC composite materials with a porosity of 15-50%, including: Woven carbon fiber fabric; Carbon fiber fabric is placed in a chemical vapor deposition furnace for pyrolytic carbon deposition to obtain interfacial deposited fabric. For interfacial deposited fabrics, liquid-phase special ceramic precursors are used as impregnating agents, and C / SiC composite materials are obtained through 2 to 6 cycles of organic precursor impregnation-pyrolysis process.
3. The method for preparing a C / SiC-Al composite material according to claim 2, characterized in that: The carbon fiber fabric structure can be any one or more of fine knitting, orthogonal triaxial, or needle-punched structures, and the fabric thickness dimension ranges from 5mm to 10mm.
4. The method for preparing a C / SiC-Al composite material according to claim 2, characterized in that: The deposition time of the pyrolytic carbon is 150h to 400h, and the thickness of the pyrolytic carbon layer is 0.5 to 2μm.
5. The method for preparing a C / SiC-Al composite material according to claim 2, characterized in that: The liquid-phase special ceramic precursor includes a liquid polycarbosilane precursor or an organic solution containing polycarbosilane.
6. The method for preparing a C / SiC-Al composite material according to claim 2, characterized in that, One round of the organic precursor impregnation-pyrolysis process includes: The process involves sequentially impregnating, curing, and pyrolyzing the interfacial deposited fabric using a liquid-phase special ceramic precursor. The impregnation pressure is 0.1–8 MPa, the impregnation time is 1–5 hours, and the impregnation temperature is 20–150℃. The curing temperature is between 120 and 450°C, and the curing time is between 1 and 10 hours.
7. The method for preparing a C / SiC-Al composite material according to claim 6, characterized in that: The pyrolysis temperature is between 900 and 1500°C, and the pyrolysis time is between 3 and 15 hours.
8. The method for preparing a C / SiC-Al composite material according to claim 1, characterized in that: In the metal infiltration process, the infiltration temperature is 500-1000℃, and pressure or vacuum-pressure alternation is adopted according to the wettability of pure aluminum or aluminum alloy with C / SiC.
9. A C / SiC-Al composite material, characterized in that, The C / SiC-Al composite material is prepared according to any one of claims 1-8.