SiC / SiC composite material for rocket engine jet pipe and preparation method of SiC / SiC composite material
By depositing BN, PyC and SiC interface layers in the SiC/SiC composite in sequence, and combining impregnation curing and cracking processes, the insufficient performance of existing materials under high temperature conditions is solved, higher tolerance and mechanical properties are achieved, and the preparation cost and cycle are reduced.
Patent Information
- Application Number
- CN202510116280.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-05-30
AI Technical Summary
The existing SiC/SiC composite materials have poor resistance and mechanical properties under conditions above 1400°C, and the preparation process has problems such as long cycles, easy fiber damage, and hole formation.
Chemical vapor-phase permeation technology is used to deposit the BN interface layer, the PyC interface layer and the SiC interface layer in sequence, and the impregnation solution prepared by combining divinylbenzene and polycarbosilane is impregnated and cured and cracked for multiple times, and finally the rare earth silicate environmental barrier coating is deposited under vacuum conditions.
It significantly enhances the resistance and mechanical properties of SiC/SiC composites above 1400°C, improves the light weight of the material, reduces the preparation cost and cycle, and extends the high temperature and flame cycle life.
Smart Images
Figure CN120058369A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of composite material processing, and particularly relates to a SiC / SiC composite material for a rocket engine nozzle and a preparation method thereof. Background Art
[0002] The nozzle of a rocket engine is an important device in the engine thrust chamber. It is responsible for converting the thermal energy of the high-temperature and high-pressure gas generated by the combustion of the propellant into kinetic energy. It needs to withstand the intense high-temperature heating effect of the gas. The gas temperature reaches between 1000 and 3000 °C, and the gas jet speed at the nozzle outlet is as high as more than 3500 m / s. With the continuous improvement of the performance requirements for aeroengines, higher requirements are put forward for the light weight, high-temperature resistance performance, and mechanical properties of the hot-end component materials. The density of a SiC / SiC composite material is only 1 / 3 - 1 / 4 of that of a superalloy. Combined with the coolant in the sandwich layer, the operating temperature can be 150 - 400 °C higher than that of a superalloy, and the potential operating temperature can reach 1800 °C.
[0003] The preparation processes of SiC / SiC composite materials mainly include chemical vapor infiltration (CVI) process, polymer precursor infiltration and pyrolysis (PIP) process, and reactive melt infiltration (RMI) process. The chemical vapor infiltration process has disadvantages such as a long preparation cycle and easy formation of closed pores on the fiber surface, resulting in low final density of the composite material; the reactive melt infiltration process is prone to cause fiber damage during the high-temperature sintering process, resulting in low mechanical properties of the composite material. Due to the release of small molecules during the pyrolysis of the polymer precursor in the precursor infiltration and pyrolysis process, pores are easily formed in the SiC / SiC composite material, and its densification degree is low, thus reducing the mechanical properties of the SiC / SiC composite material and its poor tolerance and mechanical properties under conditions above 1400 °C. Summary of the Invention
[0004] The purpose of the present invention is to provide a SiC / SiC composite material for a rocket engine nozzle and a preparation method thereof, to enhance the tolerance and mechanical properties of the SiC / SiC composite material above 1400 °C, and to solve the problems existing in the prior art.
[0005] To solve the above technical problems, the present invention adopts the following solutions:
[0006] A preparation method of a SiC / SiC composite material for a rocket engine nozzle includes the following steps:
[0007] S1, weaving SiC fibers into a 2.5D plain weave fiber cloth, laying the fiber cloth in layers and continuously needling layer by layer to obtain a SiC fiber preform;
[0008] S2. Deposit a BN interface layer, a PyC interface layer, and a SiC interface layer on the surface of the SiC fiber preform in sequence to obtain a semi-densified SiC / SiC composite material;
[0009] S3. Subject the semi-densified SiC / SiC composite material to impregnation and curing, and then pyrolysis in sequence to obtain a SiC / SiC composite material with a porous matrix;
[0010] S4. Deposit an environmental barrier coating on the surface of the SiC / SiC composite material with a porous matrix, and then clean and dry it to obtain the SiC / SiC composite material.
[0011] Furthermore, in step S1, the SiC fibers are woven with a warp and weft of 8×8 bundles / cm 2 by a 2.5D shallow cross-bent double-strand weaving method;
[0012] The needling density is 25 - 30 needles / cm 2 .
[0013] Furthermore, when depositing the BN interface layer, place the SiC fiber preform in a chemical vapor deposition furnace, and introduce argon, hydrogen, boron trichloride, and nitrogen. The gas flow rates are 1.2 L / min, 0.8 L / min, 0.3 L / min, and 1.5 L / min respectively. The deposition time is 5 - 10 h, and the deposition times are 2 - 5 times to obtain a SiC fiber preform with a BN interface layer.
[0014] Furthermore, when depositing the PyC interface layer, place the SiC fiber preform with a BN interface layer in a chemical vapor deposition furnace, and introduce propylene and a nitrogen dilution gas. The flow rate ratio of the propylene to the nitrogen dilution gas is 3:1. The deposition pressure is 0.5 - 0.6 KPa, the deposition temperature is 850 °C, the deposition time is 30 - 40 h, and the deposition times are 4 - 6 times to obtain a SiC fiber preform with a BN interface layer and a PyC interface layer.
[0015] Furthermore, when depositing the SiC interface layer, introduce a mixture of argon, hydrogen, and methyltrichlorosilane. The gas flow rate is 1.8 L / min - 3.5 L / min, the deposition temperature is 950 °C, the deposition time is 5 - 15 h, and the deposition is carried out 5 - 8 times.
[0016] Furthermore, in the impregnation and curing step, place the semi-densified SiC / SiC composite material in an impregnation solution prepared from divinylbenzene and polycarbosilane for ultrasonic impregnation. The impregnation time is 50 - 70 min, and it is dried at room temperature for 24 h. Repeat the impregnation and curing step until the weight gain rate reaches 8 - 12%.
[0017] Furthermore, the mass ratio of the divinylbenzene to the polycarbosilane is 4:6.
[0018] Further, in the cracking step, the impregnated and cured semi-densified SiC / SiC composite material is immersed in a polyallylhydroxycarbosilane precursor solution under a pressure of -0.1 MPa for 1 to 3 hours at an impregnation temperature of 200°C to 230°C. After the precursor cross-links and cures or the solvent evaporates, it is then cracked at 1000°C to 1200°C for 4 hours under the protection of an inert gas.
[0019] Further, a physical vapor deposition (PVD) environmental barrier coating is carried out under vacuum conditions, and the environmental barrier coating is rare earth silicate.
[0020] The SiC / SiC composite material prepared by the above preparation method.
[0021] The beneficial effects of the present invention are as follows: By chemical vapor infiltration, the BN interface layer, PyC interface layer, and SiC interface layer are successively introduced into the SiC fiber preform, and then impregnated multiple times with an impregnating solution prepared from divinylbenzene and polycarbosilane, cured and cracked to obtain an SiC / SiC composite material that can withstand a maximum temperature of 1525°C. The SiC / SiC composite material is lighter in weight, reduces the consumption of raw materials required for generating the SiC matrix, has the remarkable advantages of reducing the preparation cost and shortening the preparation cycle, and enhances the mechanical properties.
[0022] At the same time, an environmental barrier coating is deposited on the surface of the SiC / SiC composite material, enhancing the high-temperature resistance temperature, thermal shock life, and flame cycle life of the SiC / SiC composite material. Description of the Drawings
[0023] Figure 1 It is a schematic diagram of the preparation process flow of the present invention. Detailed Embodiments
[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.
[0025] In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.
[0026] Example 1
[0027] A preparation method of an SiC / SiC composite material for a rocket engine nozzle, referring to Figure 1 , includes the following steps:
[0028] S1, Use 8×8 bundles / cm of SiC fibers as warp and weft, and weave them into a 2.5D plain weave fiber cloth through 2.5D shallow cross-linked double-strand weaving; after weaving, the warp density of the fabric is 7.0 roots / cm, the weft density is 3.0 roots / cm, the fiber volume fraction is 45%, and the average thickness of the 2.5D plain weave fiber cloth is 0.22 mm. 2 Lay up the 2.5D plain weave fiber cloth to form a 12-layer limited laminated cloth, and continuously needle-punch each layer. The needle-punching direction is perpendicular to the plane where the fiber cloth is located, and the needle-punching density is 30 needles / cm
[0029] to obtain a SiC fiber preform. 2
[0030] S2, Deposit a BN interface layer, a PyC interface layer, and a SiC interface layer on the surface of the SiC fiber preform in sequence to obtain a semi-densified SiC / SiC composite material;
[0031] When depositing the BN interface layer, place the SiC fiber preform in a chemical vapor deposition furnace, and introduce argon, hydrogen, boron trichloride, and nitrogen. The gas flow rates are 1.2 L / min, 0.8 L / min, 0.3 L / min, and 1.5 L / min respectively. The deposition time is 7.5 h, and the deposition times are 2 times, with a total deposition of 15 h, to obtain a SiC fiber preform with a BN interface layer, where the average thickness of the BN interface layer is 400 nm.
[0032] When depositing the PyC interface layer, place the SiC fiber preform with a BN interface layer in a chemical vapor deposition furnace, and introduce propylene and a nitrogen dilution gas. The flow rate ratio of the propylene to the nitrogen dilution gas is 3:1. The deposition pressure is 0.5 KPa, the deposition temperature is 850 °C, the deposition time is 30 h, and the deposition times are 4 times, with a total deposition of 120 h, to obtain a SiC fiber preform with an interface layer, where the average thickness of the PyC interface layer is 400 nm.
[0033] When depositing the SiC interface layer, introduce a mixture of argon, hydrogen, and methyltrichlorosilane. Hydrogen is used as a carrier to bring methyltrichlorosilane into the chemical vapor deposition furnace. The gas flow rate is 2.0 L / min, the deposition temperature is 950 °C, the deposition time is 10 h, and it is deposited 7 times, with a total deposition of 70 h. The weight gain rate of the SiC / SiC composite material obtained from the first deposition is 18%, and the density is 0.6 g / cm 3 ; the weight gain rate of the SiC / SiC composite material from the second deposition is 14%, and the density is 1.2 g / cm 3 , with multiple depositions, the open pores in the composite material are diffusely filled, and the weight gain rate decreases in sequence. Finally, after the 7th deposition, the weight gain rate of the SiC / SiC composite material reaches 1%, and the density reaches 3.0 g / cm 3 , a semi-densified SiC / SiC composite material is obtained.
[0034] S3, the semi-densified SiC / SiC composite material is successively impregnated and cured, and pyrolyzed to obtain a SiC / SiC composite material with a porous matrix;
[0035] In the impregnation and curing step, the semi-densified SiC / SiC composite material is ultrasonically impregnated in an impregnating solution prepared from divinylbenzene and polycarbosilane. The impregnation time is 50 min, the ultrasonic frequency is set at 40 KHz, and it is dried at room temperature for 24 h. The impregnation and curing step is repeated until the weight gain rate reaches 8%. The mass ratio of divinylbenzene to polycarbosilane is 4:6.
[0036] In the pyrolysis step, the semi-densified SiC / SiC composite material after impregnation and curing is immersed in a polyallylhydroxycarbosilane precursor solution under a pressure of -0.1 MPa for 1 h, and the impregnation temperature is 200 °C. Then it is cured at 200 °C for 6 h, and the curing pressure is 3 MPa; after the precursor crosslinks and cures or the solvent volatilizes, the semi-densified SiC / SiC composite material is taken out and placed in a vacuum furnace, and pyrolyzed at 1000 °C for 4 h under argon gas protection. The pyrolysis pressure at this time is 0.01 MPa to obtain a SiC / SiC composite material.
[0037] S4, a physical vapor deposition (PVD) environmental barrier coating is applied to the surface of the SiC / SiC composite material with a porous matrix under vacuum conditions. The environmental barrier coating is rare earth silicate. After cleaning and drying, a SiC / SiC composite material is obtained.
[0038] Example 2
[0039] A preparation method of a SiC / SiC composite material for a rocket engine nozzle, comprising the following steps:
[0040] S1, the SiC fibers are woven into a 2.5D plain weave fiber cloth by 2.5D shallow cross-bent double-strand weaving with a warp and weft of 8×8 bundles / cm 2 . After weaving, the fabric has a warp density of 7.3 roots / cm, a weft density of 2.7 roots / cm, a fiber volume fraction of 47%, and the average thickness of the 2.5D plain weave fiber cloth is 0.22 mm.
[0041] The 2.5D plain weave fiber cloth is laminated to form a 12-layer limited laminated cloth, and is continuously needled layer by layer. The needling direction is perpendicular to the plane where the fiber cloth is located, and the needling density is 25 needles / cm 2 , to obtain a SiC fiber preform.
[0042] S2, a BN interface layer, a PyC interface layer, and a SiC interface layer are successively deposited on the surface of the SiC fiber preform to obtain a semi-densified SiC / SiC composite material;
[0043] When depositing the BN interface layer, place the SiC fiber preform in a chemical vapor deposition furnace, and introduce argon, hydrogen, boron trichloride, and nitrogen. The gas flow rates are 1.2 L / min, 0.8 L / min, 0.3 L / min, and 1.5 L / min respectively. The deposition time is 5 h, the deposition times are 4 times, and the total deposition time is 20 h, obtaining a SiC fiber preform with a BN interface layer, where the average thickness of the BN interface layer is 400 nm.
[0044] When depositing the PyC interface layer, place the SiC fiber preform with a BN interface layer in a chemical vapor deposition furnace, and introduce propylene and a nitrogen dilution gas. The flow rate ratio of propylene to the nitrogen dilution gas is 3:1. The deposition pressure is 0.6 KPa, the deposition temperature is 850 °C, the deposition time is 30 h, the deposition times are 5 times, and the total deposition time is 150 h, obtaining a SiC fiber preform with an interface layer, where the average thickness of the PyC interface layer is 400 nm.
[0045] When depositing the SiC interface layer, introduce a mixture of argon, hydrogen, and methyltrichlorosilane. Here, hydrogen is the carrier to bring methyltrichlorosilane into the chemical vapor deposition furnace. The gas flow rate is 3.5 L / min, the deposition temperature is 950 °C, the deposition time is 8 h, and the deposition is carried out 8 times, with a total deposition time of 64 h. The weight gain rate of the SiC / SiC composite material obtained from the first deposition is 20%, and the density is 0.5 g / cm 3 ; The weight gain rate of the SiC / SiC composite material in the second deposition is 16%, and the density is 1.0 g / cm 3 , with multiple depositions, the open pores in the composite material are diffusely filled, and the weight gain rate decreases successively. Finally, after the 8th deposition, the weight gain rate of the SiC / SiC composite material reaches 1%, and the density reaches 3.1 g / cm 3 , obtaining a semi-densified SiC / SiC composite material.
[0046] S3, subject the semi-densified SiC / SiC composite material to impregnation curing and pyrolysis in sequence to obtain a SiC / SiC composite material with a porous matrix;
[0047] In the impregnation curing step, place the semi-densified SiC / SiC composite material in an impregnation solution prepared from divinylbenzene and polycarbosilane for ultrasonic impregnation. The impregnation time is 70 min, the ultrasonic frequency is set at 40 KHz, and it is dried at room temperature for 24 h. Repeat the impregnation curing step until the weight gain rate reaches 10%. The mass ratio of divinylbenzene to polycarbosilane is 4:6.
[0048] In the pyrolysis step, the impregnated and cured semi-densified SiC / SiC composite material is immersed in a polyallyl hydroxycarbosilane precursor solution under a pressure of -0.1 MPa for 3 hours at an impregnation temperature of 230°C, and then cured at 200°C for 6 hours under a curing pressure of 3 MPa. After the precursor crosslinks and cures or the solvent evaporates, the semi-densified SiC / SiC composite material is taken out and placed in a vacuum furnace, and pyrolyzed at 1200°C for 4 hours under argon gas protection. The pyrolysis pressure at this time is 0.01 MPa to obtain the SiC / SiC composite material.
[0049] S4. Under vacuum conditions, a physical vapor deposition (PVD) environmental barrier coating is applied to the surface of the SiC / SiC composite material with a porous matrix. The environmental barrier coating is rare earth silicate. After cleaning and drying, the SiC / SiC composite material is obtained.
[0050] Comparative Example
[0051] The comparative example is basically the same as Example 1, except that: in step S4, no environmental barrier coating is deposited.
[0052] The SiC / SiC composite materials obtained in the above Examples 1 and 2 and the SiC / SiC composite material obtained in the comparative example are used as test samples respectively, and their densities and mechanical properties of each test sample at 1200°C to 1400°C are tested respectively. The test data are shown in Table 1.
[0053] Table 1 Basic mechanical properties of each SiC / SiC composite material
[0054]
[0055]
[0056] The SiC / SiC composite materials prepared in Example 1, Example 2 and the comparative example are tested for temperature resistance, life and weight loss rate.
[0057] Temperature resistance and life: The instantaneous (<50 h) temperature resistance of Example 1 and Example 2 is 1510 - 1525°C, and the long-term (50 h - 100 h) temperature resistance is 1350 - 1400°C.
[0058] When testing the weight loss rate: under the test conditions of steam impact pressure of 6 atm, speed of 24 m / s, 1 h as a cycle period, and a total of 200 cycles of testing, the weight loss rate (matrix loss) of the SiC / SiC composite material components in Example 1 and Example 2 is <3%. The weight loss rate (matrix loss) of the SiC / SiC composite material components in the comparative example is >20%.
[0059] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A method for preparing a SiC / SiC composite material for a rocket engine nozzle, characterized in that: The following steps are involved: S1, weaving SiC fibers into 2.5D plain weave fiber cloth, laying the fiber cloth and continuously needle-punching the fiber cloth layer by layer to obtain a SiC fiber preform; S2, sequentially depositing a BN interface layer, a PyC interface layer and a SiC interface layer on the surface of the SiC fiber preform to obtain a semi-densified SiC / SiC composite material; S3, subjecting the semi-densified SiC / SiC composite material to sequential impregnation curing and cracking to obtain a SiC / SiC composite material having a porous matrix; S4, depositing an environmental barrier coating on the surface of the SiC / SiC composite material having a porous matrix, and obtaining the SiC / SiC composite material after cleaning and drying.
2. The method for preparing a SiC / SiC composite material for a rocket engine nozzle according to claim 1, characterized in that: In step S1, SiC fibers are used in 8×8 bundles / cm 2 The warp and weft are woven, and the weaving method is 2.5D shallow cross bend double strand weaving; The acupuncture density is 25 to 30 needles / cm 2 .
3. The method for preparing a SiC / SiC composite material for a rocket engine nozzle according to claim 1, characterized in that: When depositing the BN interface layer, the SiC fiber preform is placed in a chemical vapor deposition furnace, and argon, hydrogen, boron trichloride and nitrogen are introduced. The gas flow rates are 1.2 L / min, 0.8 L / min, 0.3 L / min and 1.5 L / min respectively. The deposition time is 5 to 10 hours, and the deposition times are 2 to 5 times to obtain a SiC fiber preform with a BN interface layer.
4. The method for preparing a SiC / SiC composite material for a rocket engine nozzle according to claim 1, characterized in that: When depositing the PyC interface layer, a SiC fiber preform with a BN interface layer is placed in a chemical vapor deposition furnace, and propylene and nitrogen dilution gases are introduced, wherein the flow ratio of the propylene to nitrogen dilution gases is 3:1, the deposition pressure is 0.5-0.6 KPa, the deposition temperature is 850°C, the deposition time is 30-40 hours, and the deposition times are 4-6 times, thereby obtaining a SiC fiber preform with a BN interface layer and a PyC interface layer.
5. The method for preparing a SiC / SiC composite material for a rocket engine nozzle according to claim 1, characterized in that: When depositing the SiC interface layer, a mixture of argon, hydrogen and monomethyltrichlorosilane is introduced, the gas flow rate is 1.8L / min to 3.5L / min, the deposition temperature is 950°C, the deposition time is 5 to 15h, and the deposition is performed 5 to 8 times.
6. The method for preparing a SiC / SiC composite material for a rocket engine nozzle according to claim 1, characterized in that: In the impregnation and curing step, the semi-densified SiC / SiC composite material is ultrasonically impregnated in an impregnation solution prepared from divinylbenzene and polycarbosilane for 50 to 70 minutes, dried at room temperature for 24 hours, and the impregnation and curing steps are repeated until the weight gain rate is 8 to 12%.
7. The method for preparing a SiC / SiC composite material for a rocket engine nozzle according to claim 6, characterized in that: The mass ratio of divinylbenzene to polycarbosilane is 4:
6.
8. The method for preparing a SiC / SiC composite material for a rocket engine nozzle according to claim 1, characterized in that: In the cracking step, the semi-densified SiC / SiC composite material that has been impregnated and cured is immersed in a polyallylhydroxycarbosilane precursor solution at a pressure of -0.1 MPa for 1 to 3 hours at a temperature of 200°C to 230°C. After the precursor is cross-linked and cured or the solvent evaporates, it is cracked at 1000°C to 1200°C for 4 hours under inert gas protection.
9. The method for preparing a SiC / SiC composite material for a rocket engine nozzle according to claim 1, characterized in that: The PVD physical surface deposition of the environmental barrier coating is carried out under vacuum conditions, wherein the environmental barrier coating is a rare earth silicate.
10. A SiC / SiC composite material prepared by the preparation method according to any one of claims 1 to 9.