Near-zero expansion carbon fiber reinforced multiplet multilayer matrix composite material and preparation method and application

Abstract

The application discloses a near-zero-expansion carbon fiber reinforced multi-element multi-layer matrix composite material and a preparation method and application thereof, and relates to the technical field of ceramic matrix composite materials.The composite material comprises a carbon fiber bundle, an interface layer on the surface of the carbon fiber bundle, a multi-phase ceramic layer on the carbon interface layer and a silicon carbide coating arranged on the multi-phase ceramic layer; the multi-phase ceramic layer comprises a plurality of unit layers of different low-expansion phases which are alternately arranged; the interface layer is pyrolytic carbon or boron nitride; and the low-expansion phases comprise SiC, Si3N4 or PyC.The application effectively alleviates the thermal expansion mismatch between the fiber and the matrix in the composite material by introducing the multi-element multi-layer matrix, and greatly reduces the thermal expansion coefficient of the current ceramic matrix composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic matrix composites, in particular to a near-zero expansion carbon fiber reinforced multi-element multi-layer matrix composite material and a preparation method and application thereof. BACKGROUND

[0002] For the field of space exploration, lightweight space optical machine structural components are faced with challenges such as large changes in service environment temperature, space radiation, satellite debris impact, and space atomic oxygen corrosion. This requires space optical machine structural materials to have the characteristics of low density, excellent mechanical properties, and thermal and mechanical stability. At the same time, in order to ensure the service life and high resolution performance of lightweight space probes, the dimensional stability of space optical machine structural components such as optical mirrors and supporting structures needs to be further controlled. The space gravitational wave detection technology, as a representative, puts forward higher requirements for the precision of space probes. For space optical machine structural components as a platform for carrying optical elements, they need to meet the requirements of ultra-static and ultra-stable, i.e. the thermal expansion performance of space optical machine structural materials needs to achieve near-zero expansion within the service temperature range, with an absolute value of the thermal expansion coefficient less than 0.4×10 -6 / K.

[0003] Traditional space optical machine structural materials are mainly low-expansion materials with lightweight, high strength, and resistance to various complex service environments, mainly including metallic beryllium, traditional alloys (Ti or Al alloys), microcrystalline glass, invar alloy, and carbon fiber reinforced resin matrix composite materials. Beryllium has a small density and high mechanical properties, but has a large thermal expansion coefficient and is highly toxic; alloys have a large density, a low specific modulus, and poor thermal expansion performance; microcrystalline glass has excellent thermal expansion performance, but poor mechanical properties, and is suitable for mirror materials but not for large structural components; invar alloy has a thermal expansion coefficient of about 1.8×10 -6 / K, but has a large density of about 8.0 g / cm 3 ; carbon fiber reinforced resin matrix composite materials have a low density, but the resin matrix has poor radiation resistance, which will degrade in long-term exposure to space environment, and will also swell and deform when stored on the ground, which are difficult to meet the preparation of complex structure optical machine components. Ceramic matrix composites have the advantages of low bulk density, high modulus, low thermal expansion coefficient, and high environmental radiation resistance, and are one of the ideal choices for the next generation of space optical machine structural materials, but there is still a lack of feasible optimization direction for preparing near-zero expansion ceramic matrix composites that meet the requirements of space optical machine structural components.

[0004] The C / SiC composite material with a density of 2.65 g / cm 3 was obtained by liquid silicon infiltration process on C / C preform by ECM company in Germany, which achieved zero expansion in the temperature range of 30-100 K. This material is named It is reported that its thermal expansion coefficient at room temperature is 2.1×10-6 / K, the elastic modulus is 249 GPa, and the fracture toughness is 2.4 MPa·m 1 / 2 . and its derivative products have been widely used in space telescopes in various countries for many years.

[0005] For carbon fiber reinforced ceramic matrix composites, the thermal expansion coefficient matching and modulus matching between the fiber and the matrix are the key factors affecting the performance of the material. When the temperature cools from the preparation temperature to room temperature, the thermal expansion mismatch between the fiber and the matrix will cause residual thermal stress inside the material, which will further cause the matrix to crack. Meanwhile, considering that the thermal expansion coefficient of the commonly used SiC matrix is relatively high, it is difficult to achieve near-zero expansion by using SiC single phase as the matrix of carbon fiber reinforced ceramic matrix composites. In order to alleviate the thermal mismatch between the fiber and the matrix and realize the regulation of the expansion performance of the composite, a low-expansion or negative-expansion second phase is considered to be introduced into the SiC matrix. The thermal expansion coefficient of C / SiC prepared by the prior art is about 1.0-2.0 x 10 -6 / K. Therefore, it is difficult to achieve near-zero expansion by using SiC single phase as the matrix of C / SiC. For carbon fiber reinforced ceramic matrix composites, the thermal expansion coefficient matching and modulus matching between the fiber and the matrix are the key factors affecting the performance of the material. When the temperature cools from the preparation temperature to room temperature, the thermal expansion mismatch between the fiber and the matrix will cause residual thermal stress inside the material, which will further cause the matrix to crack, and the crack opening width and density will further affect the expansion behavior of the material. SUMMARY

[0006] In order to solve the problems existing in the background art, mainly aiming at the problem that the thermal expansion coefficient of the SiC matrix in the current C / SiC composite material is relatively high, and it is difficult to achieve near-zero expansion of the C / SiC composite material by using a single-phase matrix. The present application provides a near-zero expansion carbon fiber reinforced multi-element multi-layer matrix composite material and its preparation method and application. The method adopts a chemical vapor infiltration process, and realizes the preparation of a near-zero expansion carbon fiber reinforced alternating deposition multi-element multi-layer matrix composite material by regulating the cycle number and layer thickness ratio of multiple matrix phases in the alternating deposition process, so as to realize the readjustment and uniform distribution of the stress distribution inside the fiber bundle during the densification process. Compared with the traditional preparation process, the present application effectively alleviates the thermal expansion mismatch between the fiber and the matrix in the composite material, and greatly reduces the thermal expansion coefficient of the current ceramic matrix composite material.

[0007] In order to achieve the above purpose, the first aspect of the present application provides a near-zero expansion carbon fiber reinforced multi-element multi-layer matrix composite material, which comprises a carbon fiber bundle, an interface layer on the surface of the carbon fiber bundle, and a multi-phase ceramic matrix layer on the carbon interface layer and a silicon carbide coating layer arranged on the multi-phase ceramic layer.

[0008] The multi-phase ceramic layer comprises a plurality of unit layers of different low-expansion phases prepared alternately;

[0009] The interface layer is pyrolytic carbon or boron nitride;

[0010] The low-expansion phase comprises SiC, Si3N4 or PyC.

[0011] Preferably, the carbon fibers in the carbon fiber bundle have a diameter of 5-7 μm;

[0012] The carbon interface layer has a thickness of 150-600 nm;

[0013] The multi-phase ceramic layer has a thickness of 0.02-0.3 mm;

[0014] The silicon carbide coating has a thickness of 0.05-0.1 mm.

[0015] Preferably, the thermal expansion coefficient of the composite material is less than 0.4 x 10 -6 / K in absolute value.

[0016] The second aspect of the present application provides a method for preparing a near-zero-expansion carbon fiber-reinforced multi-element multi-layer matrix composite material, comprising the following steps:

[0017] Obtaining a carbon fiber preform;

[0018] Placing the carbon fiber preform in a deposition furnace, first vacuumizing, and then heating to 800-1000 °C, and then introducing argon and propylene, and maintaining the temperature for 60-200 h at 3-8 kPa to obtain an interface layer on the surface of the fiber bundle with a thickness of 150-600 nm, and then heating to 1500-2100 °C and maintaining the temperature for 1-2 h;

[0019] Then placing the carbon fiber preform containing the interface layer in a deposition furnace, vacuumizing, heating to a reaction temperature, and introducing different precursor gases into the reaction chamber to alternately deposit unit layers of different low-expansion phases, i.e. obtaining a multi-phase ceramic layer on the interface layer;

[0020] Placing the carbon fiber preform containing the multi-phase ceramic layer in a deposition furnace, vacuumizing, heating to 1000-1100 °C, introducing argon, hydrogen and trichloromethylsilane, and maintaining the temperature for 80-160 h to form a uniform and dense silicon carbide coating on the surface of the multi-phase ceramic layer, i.e. obtaining a near-zero-expansion carbon fiber-reinforced multi-element multi-layer matrix composite material.

[0021] Preferably, in the step of alternately depositing unit layers of different low-expansion phases, each alternately depositing is regarded as one cycle of alternately depositing, and by adjusting the cycle number of alternately depositing and the thickness ratio of the layers, the number of times of depositing each unit layer of low-expansion phase and the cycle number of alternately depositing are determined, and after the cycle number of alternately depositing,

[0022] According to the number of unit layers of each low-expansion phase and the number of cycles of the alternate deposition, the unit layers of different kinds of low-expansion phases are alternately deposited on the interface layer, i.e., a multi-phase ceramic layer is obtained on the interface layer;

[0023] The low-expansion phase comprises SiC, Si3N4 or PyC.

[0024] More preferably, when the low-expansion phase is SiC, the deposition process is as follows: after being heated to a deposition temperature of 800-1200℃, trichloromethylsilane is used as the precursor gas, argon is used as the dilution gas, hydrogen is used as the carrier gas, the ratio of the gas molar mixing ratio of hydrogen to trichloromethylsilane is 7-12, and the deposition time is 40-60h;

[0025] When the low-expansion phase is Si3N4, the deposition process is as follows: after being heated to a deposition temperature of 800-1100℃, SiCl4 and NH3 are used as the precursor gas, hydrogen is used as the dilution gas, and argon is used as the carrier gas, and the deposition time is 40-60h;

[0026] When the low-expansion phase is PyC, the deposition process is as follows: after being heated to 800-1000℃, propylene is used as the precursor gas, hydrogen is used as the dilution gas, and argon is used as the carrier gas, and the deposition time is 40-60h.

[0027] Preferably, the volume density of the multi-phase ceramic layer is controlled to be 1.7-1.9g / cm 3 , and the open porosity is 15-20vol.%.

[0028] Preferably, the pressure of the vacuum extraction is <300Pa.

[0029] Preferably, the carbon fiber preform comprises a 2D carbon fiber preform, a 2.5D carbon fiber preform or a 3D carbon fiber preform.

[0030] The 2D carbon fiber preform is obtained by weaving continuous carbon fiber tows into plain carbon fiber cloth and then laying the fiber cloth in the mold layer by layer according to the designed number of layers.

[0031] The 2.5D carbon fiber preform or the 3D carbon fiber preform is obtained by weaving in a woven manner.

[0032] The third aspect of the present application provides an application of the near-zero-expansion carbon fiber reinforced multi-element multi-layer matrix composite material in a space optical machine structure.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] The application provides a near-zero expansion carbon fiber reinforced multi-element multi-layer matrix composite material and a preparation method and application thereof. -6 / K, wherein the composite material with the deposition sequence of (SiC1-Si3N41)4-SiC1 has the best effect, the thermal expansion coefficient of which has reached 0.12*10 -6 / K, and the near-zero expansion target is achieved.

[0035] For a traditional carbon fiber reinforced composite material, the thermal expansion coefficient and modulus of carbon fiber and matrix usually have a large difference. When the preparation temperature is cooled to room temperature, the thermal expansion mismatch between the fiber and the matrix will generate residual thermal stress in the material, which will further cause the matrix to crack. The cracks generated in the fiber bundle provide space for expansion, thereby reducing the thermal expansion coefficient. Compared with the traditional carbon fiber reinforced single-phase matrix composite material, the carbon fiber reinforced multi-element multi-layer matrix composite material prepared by the application introduces multiple phases to the matrix by alternating deposition, uses a chemical vapor infiltration process, and sequentially deposits the interface and the matrix on a microscale to realize the readjustment and uniform distribution of the stress distribution inside and outside the fiber bundle during the densification process. The crack density and crack opening width in the matrix will change, effectively relieving the thermal mismatch between the fiber and the matrix and realizing the regulation of the expansion performance of the composite material, and achieving the near-zero expansion target. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a scanning electron microscope picture of the composite material prepared in Example 1.

[0037] Figure 2 It is a scanning electron microscope picture of the composite material prepared in Example 2.

[0038] Figure 3 It is a scanning electron microscope picture of the composite material prepared in Example 3. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solutions of the application and implement the same, the application will be further described below in conjunction with specific examples and drawings, but the examples are not intended to limit the application.

[0040] In order to realize the near-zero regulation of the expansion performance of the composite material, the original single-phase SiC matrix is introduced with a low expansion or negative expansion second phase, and the components and distribution thereof are accurately regulated. At present, the existing matrix preparation technology can realize the chemical vapor deposition preparation of SiC, Si3N4 and PyC matrix phases, so the Si3N4 and PyC are introduced into the C / SiC to prepare a SiC / Si3N4 / PyC multi-element and multi-layer matrix, so as to further realize the near-zero expansion optimization of the C / SiC material. Compared with the preparation route of the existing low-expansion C / SiC which usually adopts the slurry infiltration combined with the reaction melt infiltration process, the multi-element and multi-layer matrix in the present application is prepared by using the chemical vapor infiltration process, so that the regulation of the matrix components and distribution can be more accurately realized by optimizing the deposition sequence and time in the matrix preparation process, thereby accurately realizing the near-zero optimization of the expansion performance of the multi-element and multi-layer matrix modified C / SiC material.

[0041] Since the thermal expansion coefficient of the SiC matrix in the C / SiC composite material at the present stage is relatively high, the single-phase matrix is difficult to realize the near-zero expansion of the C / SiC composite material, and the existing carbon fiber reinforced multi-element and multi-layer matrix composite material is mainly used for optimizing the mechanical properties and high-temperature oxidation resistance. The present application provides a kind of near-zero expansion carbon fiber reinforced multi-element and multi-layer matrix composite material and its preparation method, which uses chemical vapor infiltration process to realize the preparation of near-zero expansion carbon fiber reinforced alternating deposition multi-element and multi-layer matrix composite material by regulating the cycle number and layer thickness ratio of multiple matrix phases in the alternating deposition process, so as to realize the readjustment and uniform distribution of the stress distribution inside and outside the fiber bundle during densification. Compared with the traditional preparation process, the present application effectively relieves the thermal expansion mismatch between the fiber and the matrix in the composite material by introducing the multi-element and multi-layer matrix, which greatly reduces the thermal expansion coefficient of the present ceramic matrix composite material.

[0042] The present application provides a kind of near-zero expansion carbon fiber reinforced multi-element and multi-layer matrix composite material, which comprises a carbon fiber bundle, an interface layer on the surface of the carbon fiber bundle, a multi-phase ceramic layer on the carbon interface layer and a silicon carbide coating layer arranged on the multi-phase ceramic layer.

[0043] The multi-phase ceramic layer comprises a plurality of unit layers of different low expansion phases arranged alternately.

[0044] The interface layer is pyrolytic carbon or boron nitride.

[0045] The low expansion phase includes SiC, Si3N4 or PyC.

[0046] It should be noted that the microstructure of the composite material mainly uses carbon fiber as the reinforcing body, and a plurality of low expansion phases such as SiC, Si3N4 and PyC are introduced around the carbon fiber to prepare a multi-element and multi-layer matrix.

[0047] According to the application, the carbon fibers in the carbon fiber bundle have a diameter of 5-7 microns;

[0048] The carbon interface layer has a thickness of 150-600 nm;

[0049] The multi-phase ceramic layer has a thickness of 0.02-0.3 mm;

[0050] The silicon carbide coating layer has a thickness of 0.05-0.1 mm.

[0051] The composite material has a thermal expansion coefficient of less than 0.4*10 -6 / K.

[0052] The application provides a preparation method of a near-zero-expansion carbon fiber reinforced multi-element multi-layer matrix composite material, comprising the following steps:

[0053] Obtaining a carbon fiber preform;

[0054] Placing the carbon fiber preform in a deposition furnace, first vacuumizing, and then heating to 800-1000 DEG C, and then introducing argon and propylene, and keeping the temperature for 60-200 hours under 3-8 kPa to obtain an interface layer with a thickness of 150-600 nm on the surface of the fiber bundle, and then heating to 1500-2100 DEG C, and keeping the temperature for 1-2 hours;

[0055] Placing the carbon fiber preform with the interface layer in a deposition furnace, vacuumizing, heating to a reaction temperature, and introducing different precursor gases into the reaction chamber to alternately deposit unit layers of different low-expansion phases, i.e. obtaining a multi-phase ceramic layer on the interface layer;

[0056] Placing the carbon fiber preform with the multi-phase ceramic layer in a deposition furnace, vacuumizing, heating to 1000-1100 DEG C, introducing argon, hydrogen and trichloromethylsilane, and keeping the temperature for 80-160 hours to form a uniform and dense silicon carbide coating layer on the surface of the multi-phase ceramic layer, i.e. obtaining the near-zero-expansion carbon fiber reinforced multi-element multi-layer matrix composite material.

[0057] In the step of alternately depositing unit layers of different low-expansion phases, each alternately depositing is regarded as one cycle of alternately depositing, the number of times of depositing each unit layer of low-expansion phase and the number of cycles of alternately depositing are determined by adjusting the ratio of the number of cycles of depositing each unit layer of low-expansion phase to the layer thickness, and after the number of cycles of alternately depositing,

[0058] According to the number of times of depositing each unit layer of low-expansion phase and the number of cycles of alternately depositing, alternately depositing unit layers of different low-expansion phases on the interface layer, i.e. obtaining a multi-phase ceramic layer on the interface layer;

[0059] The low-expansion phases include SiC, Si3N4 or PyC.

[0060] Specifically, when the low-expansion phase is SiC, the deposition process is as follows: after being heated to a deposition temperature of 800-1200℃, trichloromethylsilane is used as a precursor gas, argon is used as a dilution gas, hydrogen is used as a carrier gas, the gas molar mixing ratio of hydrogen to trichloromethylsilane is 7-12, and the deposition time is 40-60h;

[0061] When the low-expansion phase is Si3N4, the deposition process is as follows: after being heated to a deposition temperature of 800-1100℃, SiCl4 and NH3 are used as precursor gases, hydrogen is used as a dilution gas, argon is used as a carrier gas, and the deposition time is 40-60h;

[0062] When the low-expansion phase is PyC, the deposition process is as follows: after being heated to 800-1000℃, propylene is used as a precursor gas, hydrogen is used as a dilution gas, argon is used as a carrier gas, and the deposition time is 40-60h.

[0063] The volume density of the multiphase ceramic layer is controlled to be 1.7-1.9g / cm3, and the open porosity is 15-20vol.%. 3 The volume density of the multiphase ceramic layer is controlled to be 1.7-1.9g / cm3, and the open porosity is 15-20vol.%.

[0064] The pressure of the vacuum extraction is <300Pa.

[0065] Specifically, the carbon fiber preform includes a 2D carbon fiber preform, a 2.5D carbon fiber preform, or a 3D carbon fiber preform; the 2D carbon fiber preform is obtained by weaving continuous carbon fiber tows into a plain carbon fiber cloth and then laying the fiber cloth in the mold layer by layer according to the designed number of layers;

[0066] The 2.5D carbon fiber preform or the 3D carbon fiber preform is woven by using a weaving method.

[0067] In an embodiment, a preparation method of a near-zero-expansion carbon fiber reinforced multi-element multi-layer matrix composite material is provided, which includes:

[0068] Step S1: preparation of a carbon fiber preform: continuous carbon fiber tows are woven into a plain carbon fiber cloth, and then the fiber cloth is laid in the mold layer by layer according to the designed number of layers, the four corners of the mold are fixed with clamps, and then the continuous carbon fiber is stitched along the thickness direction to obtain a 2D carbon fiber preform; or a 2.5D or 3D preform is woven by using a weaving method;

[0069] Step S2: deposition and high-temperature treatment of a pyrolytic carbon interface layer: the carbon fiber preform is placed in the deposition, vacuum extraction is performed, and then the temperature is raised to 850℃, argon and propylene are introduced, the temperature is kept at 5kPa for 60-200h to obtain an interface layer with a thickness of 150-600nm on the surface of the fiber tows, and then the temperature is raised to 1800℃ and kept for 1-2h;

[0070] Step S3: Alternating deposition of multi-element and multi-layer matrix: One deposition in this step refers to placing the processed preform into a deposition furnace, heating to a reaction temperature under a pressure of <300 Pa, and carrying the precursor gas into the reaction chamber in the form of bubbling to generate the required matrix under a carrier gas, and holding for 40-60 h. For the preform processed in step S2, if the designed matrix is two phases A and B, then one deposition cycle is completed by depositing A for m furnace times and B for n furnace times (abbreviated as Am-Bn), and the deposition sequence of x cycles can be expressed as (Am-Bn)x. The cycle number and layer thickness ratio of the required deposition of different matrix phases are adjusted to control the bulk density of the material to 1.7-1.9 g / cm 3 , and the open porosity is 15-20 vol.%;

[0071] Step S4: Preparation of a silicon carbide coating: The carbon fiber preform with a dense multi-phase ceramic matrix is placed into a deposition furnace, vacuumed to a pressure of <300 Pa, heated to 1000-1100℃, and argon, hydrogen, and methyltrichlorosilane (MTS) are introduced. MTS undergoes a chemical reaction to generate a silicon carbide matrix, and the material is held for 80-160 h to generate a uniform and dense silicon carbide coating with a thickness of 0.05-0.1 mm on the surface of the material. The micropores present on the surface of the material are filled to obtain a carbon fiber reinforced multi-element and multi-layer matrix composite material with near-zero expansion.

[0072] In step S1, the fiber material is generally a carbon fiber bundle (such as T300, T800, M35J, M55J, etc.), and the carbon fiber preform is woven in one or more of various common carbon fiber weaves (such as 2D stacking, 2.5D weaving, 3D weaving, 3D needling, etc.).

[0073] The interface phase in step S2 is generally pyrolytic carbon or boron nitride.

[0074] The matrix in step S3 refers to multiple phases of SiC, Si3N4, PyC, etc. The deposition process of the SiC matrix is as follows: after heating to a deposition temperature of 800-1200℃, MTS is used as the precursor gas, argon is used as the dilution gas, and hydrogen is used as the carrier gas. The molar mixing ratio of hydrogen to MTS is 7-12, and the deposition time is 40 h. The deposition process of the Si3N4 matrix is as follows: after heating to a deposition temperature of 850℃, SiCl4 and NH3 are used as the precursor gas, hydrogen is used as the dilution gas, and argon is used as the carrier gas. The deposition time is 40 h. The deposition process of the PyC matrix is as follows: after heating to 800-1000℃, propylene is used as the precursor gas, hydrogen is used as the dilution gas, and argon is used as the carrier gas. The deposition time is 40 h.

[0075] It should be noted that by regulating the cycle number and layer thickness ratio of the multi-element multi-layer matrix, the linear expansion coefficient of the existing ceramic matrix composite material is greatly reduced, and the absolute value of the thermal expansion coefficient of the material is less than 0.4*10 -6 / K, wherein the deposition sequence is (SiC1-Si3N41)4-SiC1, the thermal expansion coefficient of the composite material is 0.12*10 -6 / K, and the near-zero expansion target is achieved.

[0076] Compared with the selection of fibers, modification of single-phase matrix, and multi-element multi-layer matrix aiming to alleviate the stress concentration of fiber-matrix interface and the problem of insufficient oxidation resistance of the traditional near-zero expansion material, the carbon fiber reinforced multi-element multi-layer matrix composite material prepared by the application introduces multiple phases into the matrix by alternating deposition, effectively alleviates the thermal mismatch between the fiber and the matrix by regulating the matrix phases with different thermal expansion properties, and realizes the regulation of the expansion performance of the composite material, thereby achieving the near-zero expansion target.

[0077] The application provides an application of the near-zero expansion carbon fiber reinforced multi-element multi-layer matrix composite material in a space optical machine structure.

[0078] The technical solutions of the application will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only exemplary and explanatory of the application, and should not be interpreted as limiting the scope of protection of the application. Any technology realized based on the above description of the application is covered within the scope of protection intended by the application.

[0079] It should be noted that, unless otherwise specified, the experimental methods used in the application are conventional methods; and unless otherwise specified, the reagents and materials used can be purchased on the market.

[0080] In the following embodiments, (Am-Bn-Cp)x represents that x cycles are deposited, each cycle is to deposit m furnace times of low expansion phase A, then to deposit n furnace times of low expansion phase B, and finally to deposit p furnace times of low expansion phase C.

[0081] Example 1

[0082] A plain-woven high-modulus carbon fiber cloth layer preform is used as a reinforcing body, the fiber volume content is 40 vol.%, a carbon interface phase is prepared on the surface of the fiber bundle of the preform by a chemical vapor infiltration process and high-temperature treatment, and a carbon interface layer with a thickness of 150 nm is obtained on the surface of the fiber bundle. Silicon carbide and silicon nitride matrices are deposited by a chemical vapor infiltration process, the deposition time of one furnace is 40 h, and the deposition sequence is (SiC1-Si3N41)5. The density of the obtained ceramic matrix composite material is 2.20 g / cm 3 , and the open porosity is 7.5 vol. %. Figure 1The microstructure of the material is mainly composed of carbon fiber bundle, pyrolytic carbon interface layer, SiC-Si3N4 matrix, etc. The in-plane linear expansion coefficient of the composite material measured in the range of -20-50°C is 0.12x10 -6 / K.

[0083] Example 2

[0084] A plain weave high modulus carbon fiber cloth layer preform is used as the reinforcing body, with a fiber volume content of 40 vol.%. A carbon interface layer with a thickness of 150 nm is prepared on the surface of the fiber bundle of the preform by a chemical vapor infiltration process and high temperature treatment. A SiC matrix is deposited by a chemical vapor infiltration process, with a one-furnace deposition time of 40 h and a deposition sequence of (SiC)7. Finally, a 0.1 mm SiC coating is prepared on the surface of the material by a chemical vapor deposition process. The density of the obtained ceramic matrix composite material is 2.11 g / cm 3 , and the open porosity is 11.9 vol. %. Figure 2 The microstructure of the material is mainly composed of carbon fiber bundle, pyrolytic carbon interface layer, SiC-Si3N4 matrix, etc. The in-plane linear expansion coefficient of the composite material measured in the range of -20-50°C is 0.12x10 -6 / K.

[0085] Example 3

[0086] A plain weave high modulus carbon fiber cloth layer preform is used as the reinforcing body, with a fiber volume content of 40 vol.%. A carbon interface layer with a thickness of 150 nm is prepared on the surface of the fiber bundle of the preform by a chemical vapor infiltration process and high temperature treatment. A SiC-Si3N4 matrix is deposited by a chemical vapor infiltration process, with a one-furnace deposition time of 50 h and a deposition sequence of Si3N41-SiC5. Finally, a 0.1 mm SiC coating is prepared on the surface of the material by a chemical vapor deposition process. The density of the obtained ceramic matrix composite material is 2.16 g / cm 3 , and the open porosity is 9.5 vol. %. Figure 3 The microstructure of the material is mainly composed of carbon fiber bundle, pyrolytic carbon interface layer, SiC-Si3N4 matrix, etc. The in-plane linear expansion coefficient of the composite material measured in the range of -20-50°C is 0.12x10 -6 / K.

[0087] Example 4

[0088] A plain weave high modulus carbon fiber cloth layering preform is used as a reinforcing body, the fiber volume content is 40 vol.%, a carbon interface phase is prepared on the fiber bundle surface of the preform by a chemical vapor infiltration process and high temperature treatment, a carbon interface layer with a thickness of 150 nm is obtained on the fiber bundle surface. A Si3N4 and SiC matrix is deposited by a chemical vapor infiltration process, the deposition time of one furnace is 60 h, the deposition sequence is Si3N41-SiC4. Finally, a 0.1 mm SiC coating is prepared on the material surface by a chemical vapor deposition process. The obtained ceramic matrix composite has a density of 2.04 g / cm 3 , an open porosity of 8.1 vol.%, and a linear expansion coefficient of 0.13 x 10 -6 / K in the in-plane direction within the range of -20℃ to 50℃.

[0089] Example 5

[0090] A plain weave T300 carbon fiber cloth layering preform is used as a reinforcing body, the fiber volume content is 40 vol.%, a carbon interface phase is prepared on the fiber bundle surface of the preform by a chemical vapor infiltration process and high temperature treatment, a carbon interface layer with a thickness of 150 nm is obtained on the fiber bundle surface. A PyC matrix is deposited by a chemical vapor infiltration process, propylene is used as the precursor gas at 5 kPa, the deposition temperature is 870℃, the deposition time of one furnace is 36 h. The deposition sequence is SiC2-PyC2-SiC3, finally, a 0.1 mm SiC coating is prepared on the material surface by a chemical vapor deposition process. The obtained ceramic matrix composite has a density of 2.08 g / cm 3 , an open porosity of 3.6 vol.%, and a linear expansion coefficient of 0.71 x 10 -6 / K in the in-plane direction within the range of -20℃ to 50℃.

[0091] In the exploration, some examples changing some process conditions are prepared, and the specific conditions are shown in Table 1.

[0092] Table 1: Deposition process and linear expansion coefficient of other examples

[0093]

[0094] From the above examples, it can be seen that different carbon fibers and matrix components have a great influence on the thermal expansion coefficient of the carbon fiber reinforced multi-component multi-layer matrix composite finally prepared, and the proportion and distribution position of each phase in the multi-component multi-layer matrix need to be optimized.

[0095] The preferred embodiments are described herein, including the best mode known to the inventors of practicing the application. Of course, variations on the preferred embodiments will occur to those of ordinary skill in the art once advised of the application in general, and the preferred embodiments in particular, without departing from the spirit and scope of the application. Therefore, it is well within the framewofk of the application to have other embodiments that are built upon the preferred embodiments and that can be missing, plus additional structures and / or functions. Accordingly, the appended claims are intended to encompass within their scope all alternatives, modifications, permutations, and variations of the preferred embodiments that have been described herein but also which can be apparent to those of ordinary skill in the art once advised of the application in general, and the preferred embodiments in particular. The following examples are provided to further illustrate the application, but should not be construed as limiting the scope of the application.

[0096] While the application has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, since the scope of the application is indicated by the appended claims, along with their equivalents.

Claims

1. A process for the production of a near-zero-expansion carbon fiber reinforced multiplet multilayer matrix composite material, characterized by, The composite material comprises carbon fiber bundles, an interface layer on the surface of the carbon fiber bundles, a multi-phase ceramic matrix layer on the interface layer, and a silicon carbide coating layer on the multi-phase ceramic matrix layer; The multi-phase ceramic matrix layer comprises a plurality of unit layers of different low-expansion phases prepared alternately; The interface layer is pyrolytic carbon; The low-expansion phases comprise SiC, Si3N4 and / or PyC; The preparation process of the composite material comprises: obtaining a carbon fiber preform; placing the carbon fiber preform in a deposition furnace, vacuumizing, heating to 800-1000 ℃, then introducing argon and propylene, and maintaining the temperature for 60-200 h at 3-8 kPa to obtain an interface layer with a thickness of 150-600 nm on the surface of the fiber bundle, and then heating to 1500-2100 ℃ and maintaining the temperature for 1-2 h; then placing the carbon fiber preform with the interface layer in a deposition furnace, vacuumizing, heating to a reaction temperature, and introducing different precursor gases into the reaction chamber to alternately deposit unit layers of different low-expansion phases, i.e. obtaining a multi-phase ceramic matrix layer on the interface layer; wherein in the step of alternately depositing unit layers of different low-expansion phases, each alternately depositing is regarded as one cycle of alternately depositing, the number of times of depositing each unit layer of low-expansion phase and the number of cycles of alternately depositing are determined by adjusting the ratio of the number of cycles of depositing different low-expansion phases to the thickness of the layer, and after the number of cycles of alternately depositing and the number of times of depositing each unit layer of low-expansion phase, unit layers of different low-expansion phases are alternately deposited on the interface layer, i.e. a multi-phase ceramic matrix layer is obtained on the interface layer; placing the carbon fiber preform with the multi-phase ceramic matrix layer in a deposition furnace, vacuumizing, heating to 1000-1100 ℃, introducing argon, hydrogen and trichloromethylsilane, and maintaining the temperature for 80-160 h to form a uniform and dense silicon carbide coating layer on the surface of the multi-phase ceramic matrix layer, i.e. obtaining a carbon fiber reinforced multi-element multi-layer matrix composite material with near-zero expansion; when the low-expansion phase is SiC, the deposition process is as follows: after heating to a deposition temperature of 800-1200 ℃, trichloromethylsilane is used as the precursor gas, argon is used as the dilution gas, hydrogen is used as the carrier gas, the ratio of the gas molar mixing ratio of hydrogen to trichloromethylsilane is 7-12, and the deposition time is 40-60 h; when the low-expansion phase is Si3N4, the deposition process is as follows: after heating to a deposition temperature of 800-1100 ℃, SiCl4 and NH3 are used as the precursor gas, hydrogen is used as the dilution gas, and argon is used as the carrier gas, and the deposition time is 40-60 h; when the low-expansion phase is PyC, the deposition process is as follows: heating to 800-1000 ℃, using propylene as the precursor gas, hydrogen as the dilution gas, and argon as the carrier gas, and the deposition time is 40-60 h; the diameter of the carbon fibers in the carbon fiber bundle is 5-7 μm; the thickness of the interface layer is 150-600 nm; the thickness of the multi-phase ceramic matrix layer is 0.02-0.3 mm; the thickness of the silicon carbide coating layer is 0.05-0.1 mm; The composite material has an absolute value of thermal expansion coefficient less than 0.4x10 -6 / K.

2. The process for the production of near-zero expansion carbon fiber reinforced multiplet multi-layer matrix composite material according to claim 1, characterized in that, The volume density of the multiphase ceramic matrix layer is controlled to be 1.7-1.9 g / cm 3 , and the open porosity is 15-20 vol.%.

3. The process for the production of near-zero expansion carbon fiber reinforced multiplet multi-layer matrix composite material according to claim 1, characterized in that, The carbon fiber preform comprises a 2D carbon fiber preform, a 2.5D carbon fiber preform or a 3D carbon fiber preform; The 2D carbon fiber preform is obtained by weaving continuous carbon fiber tows into a plain carbon fiber cloth and then laying the fiber cloth in a mold layer by layer according to the designed number of layers. The 2.5D carbon fiber preform or the 3D carbon fiber preform is woven by using a weaving method.

4. The process for the production of near-zero expansion carbon fiber reinforced multiplet multi-layer matrix composite material according to claim 1, characterized in that, The pressure of the vacuum extraction is less than 300 Pa.

5. Application of the near-zero-expansion carbon fiber reinforced multi-element multi-layer matrix composite material prepared by the method of any one of claims 1-4 to a space optical machine structure.

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