CN106966738A - Self-healing ceramic matric composite combustion chamber flame drum and preparation method and application - Google Patents

Abstract

The invention relates to a self-healing ceramic matrix composite material combustion chamber flame cylinder and its preparation method and application. The preparation method includes the following steps: using a chemical vapor deposition method to prepare a SiC interface from a combustion chamber flame cylinder prefabricated body; and then impregnating it with a precursor Densification by pyrolysis method; repeat the precursor dipping and pyrolysis method until the obtained silicon carbide substrate has a density of 1.6-1.8g/cm ³ ; prepare SiC substrate layer and BCx substrate layer on the surface of silicon carbide substrate by chemical vapor deposition method, A borosilicate self-healing matrix with a density of 2.0-2.5 g/cm ³ is obtained, and then modified at 1000° C. for 1-3 hours to obtain a composite combustion chamber flame cylinder. The composite material combustion chamber flame cylinder provided by the invention can improve the bending strength, high temperature resistance, oxidation resistance, self-healing performance and gas efficiency of the combustion chamber flame cylinder, and reduce the quality of the combustion chamber flame cylinder and the discharge of waste.

Description

Self-healing ceramic matrix composite combustion chamber flame tube and its preparation method and application

technical field

The invention relates to the technical field of structural materials for aviation, in particular to a self-healing ceramic matrix composite material combustion chamber flame tube and its preparation method and application.

Background technique

The combustion chamber is one of the core components of an aero-engine. Its main function is to convert the chemical energy of the fuel into heat energy through combustion, so as to improve the ability of the gas to expand in the turbine and nozzle. In the structural composition of the combustion chamber, the flame tube is the place to organize the combustion, and it is the key component to ensure the air splitting, sufficient combustion, uniform mixing and effective cooling of the wall. The reliability, economy and life of the combustor depend largely on the reliability and effectiveness of the flame tube, so the development of a high-performance and long-life combustor flame tube plays a vital role in improving engine performance.

The combustor flame tube is a high-temperature component among engine components, and the ambient temperature is above 1300°C for a long time. The service temperature and service performance of existing high-temperature alloy turbine components are close to the limit, so air cooling and thermal barrier coating are often used for high-temperature components Layers and other protective measures. However, the application of cold air will not only reduce the combustion efficiency of the engine; it will also complicate the structure of the components and increase the difficulty of design and processing. High-performance aero-engines seek to continuously increase the temperature in front of the turbine. When the thrust-to-weight ratio is 12-15, the temperature at the inlet of the turbine is as high as 1800°C. Barrier coating technology is also difficult to meet the design requirements of the next generation of aero-engines. It is an advanced technology to use high-temperature-resistant ceramic matrix composite materials to prepare combustion chamber flame tubes. Ceramic-based composite materials have the characteristics of high temperature resistance, low density, corrosion resistance and oxidation resistance, and can meet the needs of hot-end components in higher temperature environments. Not only is it beneficial to greatly reduce weight, but it can also save air-conditioning or even eliminate the need for cooling, thereby increasing the overall pressure ratio (Overall PressureRatios, OPR), realizing a further increase in the working temperature of 300-500°C on the basis of the temperature resistance of superalloys, and reducing the weight of the structure by 50%- 70%, it is bound to become a key heat-resistant structure preparation material for high thrust-to-weight ratio aero-engines.

The existing silicon carbide ceramic matrix composites have excellent performance and are candidates to replace superalloys as materials for the hot end components of aero-engines. However, microcracks and pores in SiC _f composites are prone to Become the channel of oxidizing medium (O ₂ and H ₂ O) and gas corrosion, resulting in the oxidation damage of the interface phase and fiber in the SiC component; in addition, the stress in the service environment will promote the cracking of the composite material matrix and accelerate the material Damage and corrosion affect its long service life in high-temperature gas environment, which seriously restricts the application of SiC ceramic matrix composites in engine combustion chamber flame tubes.

Contents of the invention

In view of the defects in the prior art, the purpose of the present invention is to provide a self-healing ceramic matrix composite combustion chamber flame tube and its preparation method and application, so as to improve the bending strength, high temperature resistance and oxidation resistance of the combustion chamber flame tube and gas efficiency, reducing the quality of the combustion chamber flame tube and the emission of NOx, COx and other wastes, and endowing the combustion chamber flame tube with self-healing properties. When cracks and holes appear in the material, the glass phase can be self-generated in situ to achieve active The effect of sealing prevents the inward diffusion of oxidizing medium, reduces the oxidation and corrosion damage of the interface and fibers, and improves the life of the combustion chamber flame tube.

To achieve the above object, the technical solution provided by the invention is:

In the first aspect, the present invention provides a method for preparing a composite material combustor flame tube, comprising the following steps: S1: preparing the SiC interface of the combustor flame tube prefabricated body by chemical vapor deposition; wherein, the reaction of the chemical vapor deposition method The gas is trichloromethylsilane; S2: the mixed solution of polycarbosilane and xylene is used as the precursor solution, and the product obtained in step S1 is densified by the precursor impregnation cracking method; the precursor impregnation cracking method is repeatedly used to obtain The silicon carbide matrix has a density of 1.6-1.8g/cm ³ ; S3: The SiC matrix layer and the BCx matrix layer are prepared on the surface of the silicon carbide matrix by chemical vapor deposition to obtain carbon with a density of 2.0-2.5g/cm ³ Borosilicate self-healing matrix; wherein, the SiC matrix layer was prepared with trichloromethylsilane as the deposition gas, and the BCx matrix layer was prepared with boron trichloride and methane as the deposition gas; S4: the borosilicate self-healing matrix was prepared at 1000 The modification treatment is carried out at ℃ for 1-3 hours to obtain the composite material combustion chamber flame cylinder. It should be noted that the modification treatment in step S4 is to fill a large amount of dense borosilicate glass phases in the pores inside and on the surface of the borosilicate self-healing matrix; Combustion chamber flame cylinder of composite material, in the water-oxygen-gas stress coupling environment, a large number of glass phases formed by the self-healing components inside the borosilicate self-healing matrix, on the one hand, can prevent the internal silicon carbide phase from being oxidized and corroded. On the other hand, the self-healing matrix of borosilicate is densified, thereby improving the bending strength and modulus of the flame cylinder of the composite material combustion chamber.

In a further embodiment of the present invention, in step S1, the chemical vapor deposition method is specifically: trichloromethylsilane is used as the reaction gas, hydrogen is used as the carrier gas, argon is used as the dilution gas, the deposition temperature is 1100-1230 °C, and the pressure is 1~5kPa, and the deposition time is 5~15h; wherein, the volume ratio of hydrogen to trichloromethylsilane is 1:8~1:12. It should be noted that the prepared SiC interface is a single phase, and the thickness of the interface is preferably 3-10 μm. Depositing a layer of silicon carbide on the surface of the prefabricated body of the combustion chamber flame tube (silicon carbide fiber) can form a weak interfacial bond between the fiber and the matrix, so that the fiber can effectively consume energy through debonding and pulling out, making the composite material obtained It shows obvious ductile fracture characteristics during failure, which is beneficial to the improvement of mechanical properties of composite materials.

In a further embodiment of the present invention, in step S2, the precursor immersion cracking method includes: under vacuum conditions, immersing the product obtained in step S1 in a mixed solution of polycarbosilane and xylene for 4 to 6 hours, and then 100 to Dry at 140°C; crack the dried product in nitrogen or argon at 800-1200°C for 3-6 hours; repeat the steps of the precursor immersion cracking method until the density of the obtained silicon carbide matrix is 1.6-1.8g/cm ³ ; Wherein, the mass fraction of polycarbosilane in the mixed solution of polycarbosilane and xylene is 20% to 50%. It should be noted that the impregnation process can be carried out in an impregnation tank. Under vacuum conditions, according to capillary phenomenon and diffusion, polycarbosilane will penetrate into the interior of the prefabricated body of the combustion chamber flame tube and fill the pores therein; pyrolysis is The polycarbosilane is transformed from an organic polymer substance into a ceramic matrix to obtain a silicon carbide matrix.

In a further embodiment of the present invention, in step S3, the preparation method of the SiC base layer is specifically: using trichloromethylsilane (CH ₃ SiCl ₃ ) as the deposition gas, hydrogen as the carrier gas, and argon as the dilution gas, and depositing The temperature is 800-1100°C, the deposition time is 10-30 hours, and the pressure is 1kPa; the flow rate of hydrogen gas is 100-400ml/min, and the flow rate of argon gas is 100-300ml/min; the preparation method of the BCx matrix layer is as follows: Using boron trichloride and methane as deposition gas, hydrogen and argon as carrier gas, deposition temperature is 900-1000°C, deposition time is 10-30h, pressure is 1kPa; among them, the flow ratio of boron trichloride and methane is 2:1～6:1, the flow rates of hydrogen and argon are both 50～80mL/min.

In a further embodiment of the present invention, in step S3, on the surface of the silicon carbide substrate, alternately prepare SiC substrate layers and BCx substrate layers in sequence to obtain a borosilicate self-healing substrate with a density of 2.0 to 2.5 g/cm ³ ; Wherein, the outermost layer of the borosilicate self-healing matrix is a SiC matrix layer. It should be noted that: on the surface of the silicon carbide substrate, the SiC substrate layer is prepared first, and then the BCx substrate layer is prepared, and this cycle is repeated to obtain a borosilicate self-healing substrate with a density of 2.0-2.5g/cm ³ , and ensure that the carbon The outermost layer of the borosilicate self-healing matrix is a SiC matrix layer, that is to say, in the obtained borosilicate self-healing matrix, the SiC matrix layer is at least two layers, and the BCx matrix layer is at least one layer; the matrix layer The order setting is to take into account the thermal matching of the SiC substrate prepared by the PIP method. When the thermal expansion coefficient of the substrate is similar, it can reduce the cracks caused by the different thermal expansion coefficients of the material in a high-temperature environment. Therefore, a layer of silicon carbide is deposited on the surface of the silicon carbide substrate first SiC matrix, and then deposit a layer of BCx matrix, and then cycle, and alternately deposit SiC matrix and BCx matrix in turn; and the last layer is set as SiC matrix, considering that SiC matrix has higher temperature resistance and oxidation resistance than BCx matrix .

In a further embodiment of the present invention, a rare earth silicate environmental barrier coating is prepared on the surface of the composite material combustion chamber flame cylinder; the raw material of the rare earth silicate environmental barrier coating includes a first component and a second component, The first component is mullite, ytterbium silicate (Yb ₂ SiO ₅ ), polyvinyl butyral (PVB) and phosphate, and the second component is ethanol; where: the first component and the second component The mass ratio is 1:1～1:3, the mass fraction of polyvinyl butyral in the first component is 4%～8%, the mass fraction of phosphate ester in the first component is 0.4%～1.0%, The mass ratio of mullite to ytterbium silicate is 88:12. It should be noted that the rare earth silicate environmental barrier coating is prepared on the surface of the composite material combustor flame tube, that is, on the surface of the composite material combustor flame tube component and the harsh environment of the engine's ultra-high temperature, corrosive medium, and high-speed airflow Set up a barrier coating between them, which can reduce the influence of the engine environment on the performance of the composite material combustor flame tube components, avoid the deterioration of the stability of the material, prevent the mechanical properties of the material from significantly decreasing, and further improve the environment of the composite material combustor flame tube. Resistance and resistance to gas corrosion.

In a further embodiment of the present invention, the preparation method of the rare earth silicate environmental barrier coating comprises: ball milling and mixing the first component and the second component for 12 to 16 hours, and painting the obtained mixture on the composite material combustion chamber flame The surface of the cylinder is then sintered at 1400°C to 1500°C for 2 to 5 hours.

In a further embodiment of the present invention, the prefabricated body of the combustion chamber flame tube is braided by a three-dimensional four-step method using silicon carbide fibers, wherein the braiding angle is 20-45°, and the volume fraction of silicon carbide fibers is 30%-50%. . It should be noted that the combustion chamber flame cylinder is the core component of the engine combustion chamber, including the flame cylinder head and the cylinder body, and the cylinder body includes the inner wall and the outer wall; The three-part prefabricated body is connected together by fiber suture technology, and the obtained product is subjected to high-temperature heat treatment to remove surface glue and impurities to obtain the prefabricated body of the combustor flame tube; the prefabricated body of the combustor flame tube is braided by a three-dimensional four-step method body, which can improve the strength of the prefabricated body of the combustion chamber flame tube and ensure excellent mechanical properties. The connection part adopts fiber suture technology, which can avoid the damage caused by the large difference in linear expansion coefficient between the ceramic matrix composite material and the superalloy fastener, and ensure connection strength while canceling the cooling system.

In a second aspect, the present invention provides a composite material combustor flame cylinder prepared according to the above-mentioned method.

In a third aspect, the present invention provides the application of the composite material combustor flame cylinder prepared above in the preparation of an engine, especially an aero-engine.

The technical scheme provided by the invention has the following advantages:

(1) The present invention adopts the three-dimensional braiding method to prepare the prefabricated body, which not only makes the prefabricated body complete and continuous in the space multi-axial plane and between the planes, but also fundamentally avoids the difference in strength and modulus of the two-dimensional laminated prefabricated body in the thickness direction, and the layer The three-dimensional braided preform has good comprehensive mechanical properties and excellent thermal shock performance.

(2) Compared with the carbon interface, the silicon carbide interface adopted in the present invention has better oxidation resistance, and the pyrolytic carbon interface layer is prone to oxidation above 400 ° C, and the composite material will be oxidized rapidly due to the carbon interface under high temperature oxidation environment There is a sharp decline in strength, and the silicon carbide interface has strong oxidation resistance in high-temperature environments and is not easy to oxidize. It plays the role of interface load transfer, making the material have better mechanical properties in high-temperature environments.

(3) The present invention adopts PIP+CVI combined technology (precursor impregnation cracking method + chemical vapor infiltration method) to prepare self-healing modified matrix, and first adopts PIP process (precursor impregnation cracking method) to prepare a certain density of silicon carbide matrix , the precursor is easily immersed in the pores between the fiber bundles, and the degree of densification between the fiber bundles is high after ceramization, and then the CVI process (chemical vapor infiltration method) is used to alternately prepare BCx and SiC substrates, which solves the problem of single PIP method (precursor) The final density of the composite material caused by dipping cracking method) and the internal stress and microcracks of the components caused by the volume shrinkage, the ceramic matrix composite material and components prepared by the combined process of the present invention have higher final density And lower porosity, reduce the internal stress and micro-cracks and other defects of materials and components during the preparation process, and also solve the difficulty of filling fiber bundles when the self-healing matrix is prepared by the CVI process (chemical vapor infiltration method) alone The problem that the density of the composite material is not high enough caused by the interspace.

(4) The environmental barrier coating prepared by the ceramic matrix composite material prepared by the brushing method in the present invention, the long-term service temperature of the combustion chamber flame tube is 1300-1500 ℃ or above, which basically exceeds the long-term service temperature of the SiC/SiC composite material. The use temperature will sharply deteriorate the surface stability of the SiC/SiC composite combustor flame tube, resulting in a significant decline in the mechanical properties of the composite material, resulting in a greatly reduced lifespan, while the environmental barrier coating is on the surface of the composite material and the high temperature of the aeroengine is harsh. Set up a barrier coating between the use environment to prevent or reduce the impact of the engine environment on the composite material sheet. At present, the process of preparing the environmental barrier coating mostly adopts the plasma spraying method. The slurry coating method in the present invention can greatly reduce the preparation cost. and preparation cycle.

(5) The technical solution provided by the present invention can improve the bending strength, high temperature resistance and oxidation resistance of the combustion chamber flame tube, reduce the quality of the combustion chamber flame tube, the weight reduction effect reaches about 50%, and the mechanical properties are high; and the structure The design is simple, the cooling system is omitted, the gas efficiency is increased, and waste emissions such as NOx and COx are reduced; moreover, the combustion chamber flame cylinder of the present invention has self-healing properties through the modified BCx+SiC matrix, and when cracks appear in the material In the case of cracks and holes, the glass phase can be self-generated in situ to achieve the effect of active sealing, prevent the inward diffusion of oxidizing media, reduce the oxidation and corrosion damage of the interface and fibers, and meet the long-life use of the combustion chamber flame tube Require. The invention provides a silicon carbide ceramic matrix composite material combustion chamber flame tube with stable high-temperature performance and excellent mechanical properties and a self-healing matrix, which solves the problems of complex structure design, heavy weight, difficult processing and temperature resistance of the existing flame tube. Low and requires air cooling, insufficient combustion of gas, materials are easily corroded by gas and other technical problems.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

detailed description

The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The experimental methods in the following examples are conventional methods unless otherwise specified.

The test materials used in the following examples, unless otherwise specified, were purchased from conventional reagent stores.

In the quantitative experiments in the following examples, three repeated experiments were set up, and the data were the mean value or mean ± standard deviation of the three repeated experiments.

The invention provides a method for preparing a composite material combustion chamber flame tube, comprising the following steps:

S1: The SiC interface was prepared by the chemical vapor deposition method on the prefabricated body of the combustor flame tube; the reaction gas of the chemical vapor deposition method was trichloromethylsilane; Braided, wherein, the braiding angle is 20-45°, the volume fraction of silicon carbide fiber is 30%-50%; the chemical vapor deposition method is specifically: trichloromethylsilane as the reaction gas, hydrogen as the carrier gas, argon gas It is a diluent gas, the deposition temperature is 1100-1230°C, the pressure is 1-5kPa, and the deposition time is 5-15h; wherein, the volume ratio of hydrogen to trichloromethylsilane is 1:8-1:12.

S2: Using the mixed solution of polycarbosilane and xylene as the precursor solution, the product obtained in step S1 is densified by the precursor impregnation and cracking method; the precursor impregnation and cracking method is used repeatedly until the obtained silicon carbide matrix has a density of 1.6 ～1.8g/cm ³ ; the precursor immersion cracking method includes: under vacuum conditions, the product obtained in step S1 is immersed in the mixed solution of polycarbosilane and xylene for 4～6 hours, and then dried at 100～140°C; The final product is cracked at 800-1200°C for 3-6 hours in nitrogen or argon; repeat the steps of the precursor immersion cracking method until the density of the obtained silicon carbide matrix is 1.6-1.8g/cm ³ ; among them, polycarbosilane The mass fraction of polycarbosilane in the mixed solution with xylene is 20%-50%.

S3: SiC matrix layer and BCx matrix layer were prepared on the surface of silicon carbide matrix by chemical vapor deposition method to obtain borosilicate self-healing matrix with a density of 2.0-2.5g/ ^cm3 ; among them, trichloromethylsilane The SiC matrix layer is prepared for the deposition gas, and the BCx matrix layer is prepared with boron trichloride and methane as the deposition gas; the preparation method of the SiC matrix layer is specifically: using trichloromethylsilane as the deposition gas, hydrogen as the carrier gas, and argon as the Dilution gas, the deposition temperature is 800-1100°C, the deposition time is 10-30h, and the pressure is 1kPa; among them, the flow rate of hydrogen gas is 100-400ml/min, and the flow rate of argon gas is 100-300ml/min; the preparation of BCx substrate layer The specific method is as follows: boron trichloride and methane are used as deposition gas, hydrogen and argon are used as carrier gas, the deposition temperature is 900-1000°C, the deposition time is 10-30h, and the pressure is 1kPa; among them, boron trichloride and methane The flow ratio of hydrogen and argon is 2:1~6:1, and the flow rate of hydrogen and argon is 50~80mL/min; on the surface of silicon carbide substrate, SiC substrate layer and BCx substrate layer are alternately prepared in turn, and the density is 2.0~2.5 g/cm ³ borosilicate self-healing matrix; wherein, the outermost layer of the borosilicate self-healing matrix is a SiC matrix layer.

S4: modifying the borosilicate self-healing matrix at 1000° C. for 1 to 3 hours to obtain a composite combustion chamber flame tube.

S5: Prepare a rare earth silicate environmental barrier coating on the surface of the composite material combustion chamber flame tube; the raw material of the rare earth silicate environmental barrier coating includes the first component and the second component, and the first component is mullite Stone, ytterbium silicate, polyvinyl butyral and phosphoric acid ester, the second component is ethanol; wherein: the mass ratio of the first component to the second component is 1:1～1:3, polyvinyl butyral The mass fraction in the first component is 4% to 8%, the mass fraction of phosphate ester in the first component is 0.4% to 1.0%, the mass ratio of mullite and ytterbium silicate is 88:12; rare earth silicon The preparation method of the salt environment barrier coating comprises: mixing the first component and the second component by ball milling for 12 to 16 hours, painting the obtained mixture on the surface of the flame cylinder of the composite material combustion chamber, and then heating it at 1400°C to 1500°C Sintering under the protection of argon for 2 to 5 hours.

The preparation method of the composite material combustor flame cylinder provided by the present invention will be further described below in conjunction with specific examples.

Embodiment one

The silicon carbide fiber is woven into the combustor flame tube preform by three-dimensional four-step method, wherein the weaving angle is 40°, and the volume fraction of silicon carbide fiber is 35%; the obtained combustor flame tube preform is prepared by chemical vapor deposition method. interface, in which trichloromethylsilane is used as the reaction gas, hydrogen is used as the carrier gas, argon is used as the diluent gas, the volume ratio of hydrogen to trichloromethylsilane is 1:10, the deposition temperature is 1130°C, and the pressure is 4.5kPa. The deposition time was 8 hours, and the thickness of the prepared SiC interface was 6 μm.

The product obtained above was impregnated with a mixed solution of polycarbosilane and xylene under vacuum conditions for 6 hours, and then dried at 120°C; the dried product was cracked at 1000°C in nitrogen for 4 hours; the precursor impregnation cracking method was repeated for 10 cycles , the density of the obtained silicon carbide matrix is 1.73g/cm ³ ; wherein, the mass fraction of polycarbosilane in the mixed solution of polycarbosilane and xylene is 30%. The obtained silicon carbide substrate is alternately prepared by chemical vapor deposition method for SiC substrate layer and BCx substrate layer, and the SiC substrate layer is prepared first: trichloromethylsilane is used as the deposition gas, hydrogen is used as the carrier gas, and argon is used as the dilution gas. The temperature is 980°C, the deposition time is 15h, and the pressure is 1kPa; among them, the flow rate of hydrogen gas is 150ml/min, and the flow rate of argon gas is 180ml/min; then prepare the BCx substrate layer: use boron trichloride and methane as deposition gas, Hydrogen and argon are used as carrier gases, the deposition temperature is 980°C, the deposition time is 15h, and the pressure is 1kPa; the flow ratio of boron trichloride and methane is 4:1, and the flow rates of hydrogen and argon are both 60mL/min ; Circulate the above-mentioned method to prepare SiC matrix layer and BCx matrix layer successively, obtain the borosilicate self-healing matrix with a density of 2.3g/ ^cm3 , and the outermost layer of the borosilicate self-healing matrix is the SiC matrix layer . The obtained borosilicate self-healing matrix was modified at 1000°C for 1.5h to obtain a composite combustor flame cylinder.

Prepare the rare earth silicate environmental barrier coating in the obtained composite material combustion chamber flame cylinder: the raw material of the rare earth silicate environmental barrier coating includes the first component and the second component, the first component is mullite, silicon Ytterbium acid, polyvinyl butyral and phosphoric acid ester, the second component is ethanol; wherein: the mass ratio of the first component and the second component is 1:3, the amount of polyvinyl butyral in the first component The mass fraction is 4%, the mass fraction of phosphate ester in the first component is 0.6%, the mass ratio of mullite and ytterbium silicate is 88:12; the first component and the second component are ball milled and mixed for 15h, and the The obtained mixture is painted on the surface of the flame cylinder of the composite material combustion chamber, and then sintered at 1450° C. under the protection of argon for 3 hours to obtain the finished product.

Embodiment two

The silicon carbide fiber is woven into the combustor flame tube preform by three-dimensional four-step method, wherein the weaving angle is 30°, and the volume fraction of silicon carbide fiber is 35%; the obtained combustor flame tube preform is prepared by chemical vapor deposition method. interface, in which trichloromethylsilane is used as the reaction gas, hydrogen is used as the carrier gas, and argon is used as the diluent gas. The volume ratio of hydrogen to trichloromethylsilane is 1:9, the deposition temperature is 1150°C, and the pressure is 3kPa. The time is 6 hours, and the thickness of the prepared SiC interface is 4 μm.

The product obtained above was impregnated with a mixed solution of polycarbosilane and xylene under vacuum conditions for 5 hours, and then dried at 120°C; the dried product was cracked at 950°C in nitrogen for 6 hours; the precursor dipping cracking method was repeated for 8 cycles , the density of the obtained silicon carbide matrix is 1.62g/cm ³ ; wherein, the mass fraction of polycarbosilane in the mixed solution of polycarbosilane and xylene is 35%. The obtained silicon carbide substrate is alternately prepared by chemical vapor deposition method for SiC substrate layer and BCx substrate layer, and the SiC substrate layer is prepared first: trichloromethylsilane is used as the deposition gas, hydrogen is used as the carrier gas, and argon is used as the dilution gas. The temperature is 900°C, the deposition time is 13 hours, and the pressure is 1kPa; among them, the flow rate of hydrogen gas is 200ml/min, and the flow rate of argon gas is 300ml/min; then prepare the BCx substrate layer: use boron trichloride and methane as deposition gases, Hydrogen and argon were used as carrier gases, the deposition temperature was 950°C, the deposition time was 13 hours, and the pressure was 1kPa; the flow ratio of boron trichloride and methane was 3:1, and the flow rates of hydrogen and argon were both 65mL/min ; Circulate the above-mentioned method to prepare SiC base layer and BCx base layer in turn, and obtain a borosilicate self-healing matrix with a density of 2.1g/ ^cm3 , and the outermost layer of the boron-silicon self-healing matrix is a SiC base layer . The obtained borosilicate self-healing matrix was modified at 1000°C for 2 hours to obtain a composite combustor flame cylinder.

Prepare the rare earth silicate environmental barrier coating in the obtained composite material combustion chamber flame cylinder: the raw material of the rare earth silicate environmental barrier coating includes the first component and the second component, the first component is mullite, silicon Ytterbium acid, polyvinyl butyral and phosphoric acid ester, the second component is ethanol; wherein: the mass ratio of the first component and the second component is 1:2, the amount of polyvinyl butyral in the first component The mass fraction is 5%, the mass fraction of phosphate ester in the first component is 0.6%, the mass ratio of mullite and ytterbium silicate is 88:12; the first component and the second component are ball milled and mixed for 12h, and the The obtained mixture is painted on the surface of the flame cylinder of the composite material combustion chamber, and then sintered with argon at 1400° C. for 3 hours to obtain the finished product.

Embodiment three

The silicon carbide fiber is woven into the combustor flame tube prefabricated body by a three-dimensional four-step method, wherein the weaving angle is 20°, and the volume fraction of the silicon carbide fiber is 30%; the obtained combustor flame tube preform is prepared by chemical vapor deposition method. interface, in which trichloromethylsilane is used as the reaction gas, hydrogen is used as the carrier gas, argon is used as the diluent gas, the volume ratio of hydrogen to trichloromethylsilane is 1:8, the deposition temperature is 1100°C, the pressure is 1kPa, The time is 10 h, and the thickness of the prepared SiC interface is 8 μm.

The product obtained above was impregnated with a mixed solution of polycarbosilane and xylene for 4 h under vacuum conditions, and then dried at 100 ° C; the dried product was cracked at 900 ° C in nitrogen for 4 h; the precursor dipping cracking method was repeated for 8 cycles, The obtained silicon carbide matrix has a density of 1.64 g/cm ³ ; wherein, the mass fraction of polycarbosilane in the mixed solution of polycarbosilane and xylene is 50%. The obtained silicon carbide substrate is alternately prepared by chemical vapor deposition method for SiC substrate layer and BCx substrate layer, and the SiC substrate layer is prepared first: trichloromethylsilane is used as the deposition gas, hydrogen is used as the carrier gas, and argon is used as the dilution gas. The temperature is 800°C, the deposition time is 10h, and the pressure is 1kPa; among them, the flow rate of hydrogen gas is 100ml/min, and the flow rate of argon gas is 100ml/min; then prepare the BCx substrate layer: use boron trichloride and methane as deposition gases, Hydrogen and argon are used as carrier gases, the deposition temperature is 980°C, the deposition time is 10h, and the pressure is 1kPa; the flow ratio of boron trichloride and methane is 2:1, and the flow rates of hydrogen and argon are both 50mL/min ; Circulate the above-mentioned method to prepare SiC base layer and BCx base layer in turn, and obtain a borosilicate self-healing matrix with a density of 2.05g/ ^cm3 , and the outermost layer of the boron-silicon self-healing matrix is a SiC base layer . The obtained borosilicate self-healing matrix was modified at 1000°C for 1 hour to obtain a composite combustor flame cylinder.

Prepare the rare earth silicate environmental barrier coating in the obtained composite material combustion chamber flame cylinder: the raw material of the rare earth silicate environmental barrier coating includes the first component and the second component, the first component is mullite, silicon Ytterbium acid, polyvinyl butyral and phosphoric acid ester, the second component is ethanol; wherein: the mass ratio of the first component and the second component is 1:1, the polyvinyl butyral in the first component The mass fraction is 4%, the mass fraction of phosphate ester in the first component is 0.4%, the mass ratio of mullite and ytterbium silicate is 88:12; the first component and the second component are ball milled and mixed for 12h, and the The obtained mixture is painted on the surface of the flame tube of the composite material combustion chamber, and then sintered at 1400° C. under the protection of argon for 2 hours to obtain the finished product.

Embodiment Four

The silicon carbide fiber is woven into the combustor flame tube preform by three-dimensional four-step method, wherein the weaving angle is 45°, and the volume fraction of silicon carbide fiber is 50%; the obtained combustor flame tube preform is prepared by chemical vapor deposition method. interface, in which trichloromethylsilane is used as the reaction gas, hydrogen is used as the carrier gas, argon is used as the diluent gas, the volume ratio of hydrogen to trichloromethylsilane is 1:12, the deposition temperature is 1230°C, and the pressure is 5kPa. The time is 8 hours, and the thickness of the prepared SiC interface is 9 μm.

The product obtained above was impregnated with a mixed solution of polycarbosilane and xylene under vacuum conditions for 6 hours, and then dried at 140°C; the dried product was cracked at 1200°C in nitrogen for 6 hours; the precursor dipping cracking method was repeated for 12 cycles , the density of the obtained silicon carbide matrix is 1.8 g/cm ³ ; wherein, the mass fraction of polycarbosilane in the mixed solution of polycarbosilane and xylene is 50%. The obtained silicon carbide substrate is alternately prepared by chemical vapor deposition method for SiC substrate layer and BCx substrate layer, and the SiC substrate layer is prepared first: trichloromethylsilane is used as the deposition gas, hydrogen is used as the carrier gas, and argon is used as the dilution gas. The temperature is 1100°C, the deposition time is 30h, and the pressure is 1kPa; among them, the flow rate of hydrogen gas is 400ml/min, and the flow rate of argon gas is 200ml/min; then prepare the BCx substrate layer: use boron trichloride and methane as deposition gases, Hydrogen and argon are used as carrier gas, the deposition temperature is 1000°C, the deposition time is 30h, and the pressure is 1kPa; the flow ratio of boron trichloride and methane is 6:1, and the flow rate of hydrogen and argon is 80mL/min ; Circulate the above-mentioned method to prepare SiC base layer and BCx base layer in turn to obtain a borosilicate self-healing matrix with a density of 2.5g/ ^cm3 , and the outermost layer of the boron-silicon self-healing matrix is a SiC base layer . The obtained borosilicate self-healing matrix was modified at 1000°C for 3 hours to obtain a composite combustor flame cylinder.

Prepare the rare earth silicate environmental barrier coating in the obtained composite material combustion chamber flame cylinder: the raw material of the rare earth silicate environmental barrier coating includes the first component and the second component, the first component is mullite, silicon Ytterbium acid, polyvinyl butyral and phosphoric acid ester, the second component is ethanol; wherein: the mass ratio of the first component and the second component is 1:3, the amount of polyvinyl butyral in the first component The mass fraction is 8%, the mass fraction of phosphate in the first component is 1.0%, and the mass ratio of mullite and ytterbium silicate is 88:12; the first component and the second component are ball milled and mixed for 16h, and the The obtained mixture is painted on the surface of the flame cylinder of the composite material combustion chamber, and then sintered at 1500° C. under the protection of argon for 5 hours to obtain the finished product.

The composite material combustor flame cylinder prepared in Examples 1 to 4 of the present invention was tested for performance, and the TiAl superalloy combustion chamber flame cylinder in the prior art was used as a comparative example. The specific results are shown in Table 1 below:

Table 1 Performance of the flame tube in the composite material combustor

It should be noted that, in addition to the situations listed in the first to fourth examples above, it is also feasible to select other parameters of the preparation method.

The self-healing ceramic matrix composite aero-engine combustor flame tube provided by the preparation method provided by the present invention has the following advantages: (1) the present invention adopts a three-dimensional weaving method to prepare the preform, which not only makes the preform more space It is completely continuous in the axial plane and between the planes, fundamentally avoiding the shortcomings of poor strength and modulus in the thickness direction of the two-dimensional laminated prefabricated body, low interlayer shear strength and low damage tolerance, and the three-dimensional braided prefabricated body is comprehensive Good mechanical properties, excellent thermal shock properties. (2) Compared with the carbon interface, the silicon carbide interface adopted in the present invention has better oxidation resistance, and the pyrolytic carbon interface layer is prone to oxidation above 400 ° C, and the composite material will be oxidized rapidly due to the carbon interface under high temperature oxidation environment There is a sharp decline in strength, and the silicon carbide interface has strong oxidation resistance in high-temperature environments and is not easy to oxidize. It plays the role of interface load transfer, making the material have better mechanical properties in high-temperature environments. (3) The present invention adopts PIP+CVI combined technology (precursor impregnation cracking method + chemical vapor infiltration method) to prepare self-healing modified matrix, and first adopts PIP process (precursor impregnation cracking method) to prepare a certain density of silicon carbide matrix , the precursor is easily immersed in the pores between the fiber bundles, and the degree of densification between the fiber bundles is high after ceramization, and then the CVI process (chemical vapor infiltration method) is used to alternately prepare BCx and SiC substrates, which solves the problem of single PIP method (precursor) The final density of the composite material caused by dipping cracking method) and the internal stress and microcracks of the components caused by the volume shrinkage, the ceramic matrix composite material and components prepared by the combined process of the present invention have higher final density And lower porosity, reduce the internal stress and micro-cracks and other defects of materials and components during the preparation process, and also solve the difficulty of filling fiber bundles when the self-healing matrix is prepared by the CVI process (chemical vapor infiltration method) alone The problem that the density of the composite material is not high enough caused by the interspace. (4) The environmental barrier coating prepared by the ceramic matrix composite material prepared by the brushing method in the present invention, the long-term service temperature of the combustion chamber flame tube is 1300-1500 ℃ or above, which basically exceeds the long-term service temperature of the SiC/SiC composite material. The use temperature will sharply deteriorate the surface stability of the SiC/SiC composite combustor flame tube, resulting in a significant decline in the mechanical properties of the composite material, resulting in a greatly reduced lifespan, while the environmental barrier coating is on the surface of the composite material and the high temperature of the aeroengine is harsh. Set up a barrier coating between the use environment to prevent or reduce the impact of the engine environment on the composite material sheet. At present, the process of preparing the environmental barrier coating mostly adopts the plasma spraying method. The slurry coating method in the present invention can greatly reduce the preparation cost. and preparation cycle.

Adopting the technical solution provided by the invention can improve the bending strength, high temperature resistance and oxidation resistance of the combustion chamber flame cylinder, reduce the quality of the combustion chamber flame cylinder, achieve a weight reduction effect of about 50%, and have high mechanical properties; and the structure design is simple , save the cooling system, increase gas efficiency, and reduce waste emissions such as NOx and COx; moreover, the combustion chamber flame tube of the present invention has self-healing properties through the modified BCx+SiC matrix, and when cracks and holes appear in the material At the same time, the glass phase can be self-generated in situ at the cracks and holes to achieve the effect of active sealing, prevent the inward diffusion of oxidizing media, reduce the oxidation and corrosion damage of the interface and fibers, and meet the long-life service requirements of the combustion chamber flame tube. The invention provides a silicon carbide ceramic matrix composite material combustion chamber flame tube with stable high-temperature performance and excellent mechanical properties and a self-healing matrix, which solves the problems of complex structure design, heavy weight, difficult processing and temperature resistance of the existing flame tube. Low and requires air cooling, insufficient combustion of gas, materials are easily corroded by gas and other technical problems.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, those skilled in the art can make the above-mentioned The embodiments are changed, modified, replaced and modified without making the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention, and all of them should be covered by the scope of the claims and description of the present invention.

Claims (10)

1. a preparation method of a composite material combustor flame tube, is characterized in that, comprises the steps: S1: Prepare the SiC interface of the prefabricated body of the combustor flame tube by chemical vapor deposition; wherein, the reaction gas of the chemical vapor deposition method is trichloromethylsilane; S2: Using the mixed solution of polycarbosilane and xylene as the precursor solution, the product obtained in the step S1 is densified by the precursor impregnation cracking method; the precursor impregnation cracking method is repeatedly used to obtain the silicon carbide substrate The density is 1.6～1.8g/cm ³ ; S3: Prepare a SiC matrix layer and a BCx matrix layer on the surface of the silicon carbide matrix by chemical vapor deposition to obtain a borosilicate self-healing matrix with a density of 2.0 to 2.5 g/cm ³ ; wherein trichloroform base silane is used as deposition gas to prepare the SiC substrate layer, and boron trichloride and methane are used as deposition gas to prepare the BCx substrate layer; S4: The borosilicate self-healing matrix is modified at 1000° C. for 1-3 hours to obtain a composite combustion chamber flame tube. 2. the preparation method of composite material combustor flame tube according to claim 1, is characterized in that: in described step S1, described chemical vapor deposition method is specifically: take trichloromethylsilane as reaction gas, hydrogen is Carrier gas, argon is the diluent gas, the deposition temperature is 1100-1230°C, the pressure is 1-5kPa, and the deposition time is 5-15h; wherein, the volume ratio of the hydrogen to the trichloromethylsilane is 1:8 ~1:12. 3. The preparation method of the composite material combustor flame tube according to claim 1, characterized in that: in the step S2, the precursor immersion cracking method comprises: under vacuum conditions, the step S1 obtained The product is immersed in a mixed solution of polycarbosilane and xylene for 4-6 hours, and then dried at 100-140° C.; the dried product is cracked at 800-1200° C. for 3-6 hours in nitrogen or argon; repeat the The step of the precursor immersion cracking method, until the obtained silicon carbide matrix has a density of 1.6-1.8 g/cm ³ ; wherein, the mass fraction of polycarbosilane in the mixed solution of polycarbosilane and xylene is 20%-50% %. 4. the preparation method of composite material combustor flame tube according to claim 1, is characterized in that: in described step S3, the preparation method of described SiC matrix layer is specifically: take trichloromethylsilane as deposition gas, Hydrogen is the carrier gas, argon is the dilution gas, the deposition temperature is 800-1100°C, the deposition time is 10-30 hours, and the pressure is 1kPa; wherein, the flow rate of the hydrogen gas is 100-400ml/min, and the flow rate of the argon gas 100-300ml/min; the preparation method of the BCx substrate layer is as follows: using boron trichloride and methane as deposition gas, hydrogen and argon as carrier gas, deposition temperature is 900-1000°C, and deposition time is 10-100 °C. 30h, the pressure is 1kPa; wherein, the flow ratio of the boron trichloride and the methane is 2:1-6:1, and the flow rates of the hydrogen and the argon are both 50-80mL/min. 5. The preparation method of the composite material combustor flame tube according to claim 1, characterized in that: in the step S3, on the surface of the silicon carbide matrix, the SiC matrix layer and the BCx are alternately prepared successively The matrix layer is obtained with a borosilicate self-healing matrix with a density of 2.0-2.5 g/cm ³ ; wherein, the outermost layer of the borosilicate self-healing matrix is the SiC matrix layer. 6. the preparation method of composite material combustor flame tube according to claim 1 is characterized in that: on the surface of described composite material combustor flame tube, prepare rare earth silicate environmental barrier coating; Described rare earth silicic acid The raw material of the saline environmental barrier coating includes a first component and a second component, the first component is mullite, ytterbium silicate, polyvinyl butyral and phosphate, and the second component is ethanol ; Wherein: the mass ratio of the first component and the second component is 1:1～1:3, and the mass fraction of the polyvinyl butyral in the first component is 4%～ 8%, the mass fraction of the phosphoric acid ester in the first component is 0.4%-1.0%, and the mass ratio of the mullite to the ytterbium silicate is 88:12. 7. the preparation method of composite material combustor flame cylinder according to claim 6 is characterized in that: the preparation method of described rare earth silicate environmental barrier coating comprises: the described first component and the described second The components are ball-milled and mixed for 12-16 hours, and the obtained mixture is painted on the surface of the flame tube of the composite material combustion chamber, and then sintered at 1400°C-1500°C for 2-5 hours. 8. the preparation method of composite material combustor flame cylinder according to claim 1, is characterized in that: described combustion chamber flame cylinder prefabricated body is to adopt silicon carbide fiber to form with three-dimensional four-step method braiding, and wherein, braiding angle is 20-45°, the volume fraction of the silicon carbide fiber is 30%-50%. 9. The composite material combustor flame tube prepared by the method according to any one of claims 1 to 8. 10. The application of the composite material combustor flame cylinder according to claim 9 in the preparation of engines, especially in the preparation of aeroengines.