Preparation Method and Application of an Ultra-Thin Carbon-Ceramic Composite Nozzle Extension

Abstract

The present invention provides a manufacturing method and application of an ultra-thin carbon-ceramic composite nozzle extension section, belonging to the technical field of carbon fiber composite material preparation. The nozzle extension section provided by the present invention is a thin-walled rotary body structure with a bell-shaped outer shape feature. During the manufacturing process, near-net-size forming of the nozzle extension section is achieved through deformation control and deformation compensation. The carbon-ceramic composite nozzle extension section prepared by the present invention has the characteristics of light weight, low porosity, excellent mechanical properties, uniform distribution of ceramic phase, strong thermal stability and environmental adaptability, and has the advantages of simple process, convenient operation, short cycle and low comprehensive cost. It can be applied to the nozzle extension section of a new generation of high-performance solid / liquid rocket engines.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature structural components of carbon-ceramic composites, and particularly relates to a preparation method and application of an ultra-thin carbon-ceramic composite nozzle extension section. Background Art

[0002] Currently, most rocket engines use metal sandwich cooling and single-wall radiation cooling nozzles. As large expansion ratio nozzles, they have obvious structural weight disadvantages, and there are also problems such as insufficient high-temperature resistance, poor resistance to environmental erosion, and poor environmental adaptability.

[0003] Continuous carbon fiber reinforced ceramic matrix composites (carbon-ceramic composites) are new high-temperature structural materials with the characteristics of light weight, high temperature resistance, corrosion resistance, and reusability. They combine the excellent mechanical properties of carbon fibers and the good thermal stability and physical properties of carbide ceramics, and have excellent properties such as light weight, corrosion resistance, good wear resistance, good thermal shock resistance, good oxidation resistance, and good high-temperature mechanical properties. They are widely used in the thermal protection structures of aircraft and are an important development direction for rocket engine nozzles.

[0004] Replacing traditional metal materials with carbon-ceramic composite nozzle extension sections can reduce the weight of components by more than 50%, effectively improve the load of the engine. Their excellent heat resistance and anti-ablative properties can significantly simplify the cooling structure of the expansion section, greatly reducing the structural weight while improving the overall reliability of the structure. Therefore, carbon-ceramic composites can achieve the integration of multiple functions such as weight reduction, heat dissipation, and structure of rocket engine nozzles, and are the best choice for large-size, large expansion ratio, and lightweight nozzle materials.

[0005] Currently, the main methods for preparing carbon-ceramic composite nozzles are chemical vapor infiltration (CVI) and precursor infiltration and pyrolysis (PIP). The C / C-SiC composites prepared by the CVI method and the PIP method have excellent comprehensive properties, but both have the problems of high cost, long cycle, and environmental unfriendliness; reaction melt infiltration (RMI), as another method for preparing carbon-ceramic composites, is to infiltrate liquid metal into a porous carbon-carbon green body and form a carbon-ceramic composite through in-situ reaction. This method has the characteristics of short cycle and low cost. At present, no carbon-ceramic rotary body structural parts with ultra-thin wall characteristics have been found to be prepared by the RMI method. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a preparation method and application of an ultra-thin carbon-ceramic composite nozzle extension section. The method provided by the present invention is simple in process, convenient to operate, process controllable, low in cost, and short in cycle.

[0007] The present invention provides a preparation method of an ultra-thin carbon-ceramic composite nozzle extension section, including:

[0008] Perform a first high-temperature heat treatment on the carbon fiber profiling preform to obtain a product after the first high-temperature treatment;

[0009] Subject the product after the first high-temperature treatment to chemical vapor infiltration to obtain a porous carbon-carbon nozzle extension blank;

[0010] Perform a second high-temperature heat treatment and machining on the porous carbon-carbon nozzle extension blank to obtain a product after the second high-temperature treatment;

[0011] Subject the product after the second high-temperature treatment to reactive melt infiltration to obtain a carbon-ceramic nozzle extension blank;

[0012] Perform finish machining on the carbon-ceramic nozzle extension blank to obtain an ultra-thin carbon-ceramic composite nozzle extension;

[0013] During the first high-temperature heat treatment process, a first tooling is arranged inside the carbon fiber profiling preform, and the outer surface shape and size of the first tooling after expansion during the first high-temperature heat treatment are the same as the inner surface shape and size of the pre-obtained carbon fiber profiling preform.

[0014] Preferably, during the chemical vapor deposition process, a second tooling is arranged inside the product after the first high-temperature treatment, and the outer surface shape and size of the second tooling after expansion during chemical vapor deposition are the same as the inner surface shape and size of the pre-obtained porous carbon-carbon nozzle extension blank.

[0015] Preferably, during the chemical vapor deposition process, a third tooling is arranged outside the product after the first high-temperature treatment;

[0016] A gap is arranged between the third tooling and the product after the first high-temperature treatment, serving as a gas flow channel during the chemical vapor deposition process.

[0017] Preferably, the shape of the inner surface of the third tooling is designed to match the outer surface shape of the product after the first high-temperature treatment, so that the cross-sectional area of the gas used for chemical vapor deposition passing through between the product after the first high-temperature treatment and the third tooling is the same.

[0018] Preferably, during the second high-temperature treatment process, a fourth tooling is arranged inside the porous carbon-carbon nozzle extension blank, and the structural dimensions of the fourth tooling are the same as those of the first tooling.

[0019] Preferably, during the reactive melt infiltration process, a fifth tooling is arranged outside the product after the second high-temperature treatment; a gap is arranged between the product after the second high-temperature treatment and the fifth tooling, and the gap is filled with infiltration powder.

[0020] Preferably, a sixth tooling is arranged inside the product after the second high-temperature treatment during the reaction infiltration process, and the structural dimensions of the sixth tooling are the same as those of the first tooling.

[0021] Preferably, the materials of the first tooling, the second tooling, the third tooling, the fourth tooling, the fifth tooling, and the sixth tooling are independently selected from carbon materials.

[0022] Preferably, the distance of the gap is 30 - 80 mm.

[0023] The present invention provides a rocket engine, including: an ultra-thin carbon-ceramic composite nozzle extension section prepared by the method described in the above technical solution.

[0024] The present invention provides a manufacturing method for an ultra-thin wall carbon-ceramic composite nozzle extension section, which has the characteristics of simple method, convenient operation, controllable process, low cost, short cycle, etc., and is suitable for near-net shaping of special-shaped thin-wall carbon-ceramic composites and components, providing an effective method for the efficient preparation and low-cost production of special-shaped thin-wall carbon-ceramic composite components. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a process flow chart for preparing an ultra-thin wall carbon-ceramic composite nozzle extension section in an embodiment of the present invention;

[0026] Figure 2 It is a physical diagram of the ultra-thin wall carbon-ceramic composite nozzle extension section prepared in an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of different thickness regions of a carbon fiber profile preform prepared in an embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the allowance design of a carbon fiber profile preform in an embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of the allowance design of a carbon fiber profile preform in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] The present invention provides a preparation method for an ultra-thin carbon-ceramic composite nozzle extension section, including:

[0032] The carbon fiber profiling preform is subjected to a first high-temperature heat treatment to obtain a product after the first high-temperature treatment;

[0033] The product after the first high-temperature treatment is subjected to chemical vapor infiltration to obtain a porous carbon-carbon nozzle extension blank;

[0034] The porous carbon-carbon nozzle extension blank is subjected to a second high-temperature heat treatment and machining to obtain a product after the second high-temperature treatment;

[0035] The product after the second high-temperature treatment is subjected to reactive melt infiltration to obtain a carbon-ceramic nozzle extension blank;

[0036] The carbon-ceramic nozzle extension blank is subjected to finish machining to obtain an ultra-thin carbon-ceramic composite nozzle extension;

[0037] During the first high-temperature heat treatment process, a first tooling is arranged inside the carbon fiber profiling preform, and the outer shape size of the first tooling after expansion during the first high-temperature heat treatment is the same as the inner shape size of the pre-obtained carbon fiber profiling preform.

[0038] In the present invention, the ultra-thin carbon-ceramic composite nozzle extension is preferably an ultra-thin carbon-ceramic composite attitude control nozzle extension.

[0039] In the present invention, the thinnest part (minimum thickness dimension) of the wall thickness of the ultra-thin carbon-ceramic composite nozzle extension is preferably ≤2 mm; the method provided herein is also applicable to carbon-ceramic composite components with a wall thickness exceeding 2 mm.

[0040] In the present invention, the ultra-thin carbon-ceramic composite is preferably a carbon fiber reinforced carbon and ceramic dual matrix composite, and the ceramic is preferably a carbide ceramic, more preferably selected from one or more of SiC, ZrC, HfC, TiC, TaC, and NbC.

[0041] In the present invention, the ultra-thin carbon-ceramic composite nozzle extension is preferably a thin-walled rotating body structure with a bell-shaped outer shape feature; its wall thickness preferably has a gradual change feature, preferably gradually changing from 3.5 - 4 mm at the inlet end to 1.5 - 2 mm at the outlet end, as Figure 2 shown.

[0042] In the present invention, it is preferred to carry out structural design and molding on the carbon fiber profiling preform. In the present invention, the carbon fiber profiling preform is preferably a thin-walled, variable curvature, variable thickness structure, and its outer shape feature is similar to that of the nozzle extension product, and preferably a certain margin is set for the thickness and the axial direction. The method provided by the present invention is also applicable to the manufacturing of special-shaped components with non-rotating body and face-symmetric structural features and other carbon-ceramic composite components with simple outer shape features.

[0043] In the present invention, the carbon fiber preform preferably has a certain deformation allowance and machining allowance at the boundaries in the thickness direction and in-plane direction, such as Figure 4 and Figure 5 shown. The dark part is the product area, and the light part is the allowance of the preform, which is convenient for shape control. This part of the allowance will be removed in the final product processing section; the thickness direction allowance is preferably set to 0.5 - 2 mm, more preferably 1 - 1.5 mm; the single-segment allowance at the in-plane boundary is preferably set to 5 - 10 mm, more preferably 6 - 9 mm, and most preferably 7 - 8 mm.

[0044] In the present invention, the carbon fiber profiled preform is preferably a woven body, a two-dimensional laminated structure preform or a carbon fiber preform with other structures. In the present invention, the carbon fiber profiled preform is preferably a 2.5D needle-punched preform, a 3D stitched preform and a multi-dimensional woven preform, and more preferably a 2.5D needle-punched preform and / or a 3D stitched preform.

[0045] In the present invention, the carbon fiber profiled preform preferably uses carbon cloth / wire mesh / fiber grid or carbon cloth / fiber grid as the laminated structure unit, and preferably uses the needle-punching or stitching process to connect different laminated structures. In the present invention, the carbon cloth is preferably one or more of satin cloth, twill cloth and plain cloth; the arrangement direction of the fiber grid in the single laminated structure unit is preferably ±45°.

[0046] In the present invention, the forming process of the carbon fiber profiled preform is preferably completed using a mold. The carbon fiber profiled preform has a thin-wall feature, and its forming is realized by means of a profiled mold.

[0047] In the present invention, the carbon fiber profiled preform is preferably a two-dimensional laminated structure preform, and is preferably laminated periodically according to a certain angle change rule with carbon fiber cloth as the main body, and is connected in the Z direction (the thickness direction of the preform, perpendicular to the surface of the preform).

[0048] In the present invention, the thickness change of the carbon fiber profiled preform is preferably achieved by intercalation or layer reduction, such as Figure 3 shown, and the thickness of different regions can be set by changing the number of cloth layers.

[0049] In the present invention, the volume density of the carbon fiber preform is preferably 0.4 - 1.0 g / cm 3 ³, more preferably 0.55 - 0.9 g / cm 3 .

[0050] In view of the characteristics of the nozzle extension with a rotating body, variable curvature, variable thickness, and ultra-thin wall structure, a two-dimensional laminated structure preform with low manufacturing cost is selected. ±45° grid fibers with a certain tension are introduced inside the laminated structure unit, which improves the adhesion between the laminated structures, effectively ensures the consistency and compactness of the carbon fiber content and fiber arrangement inside the preform, reduces the content of interlayer defects, and ensures the overall performance and reliability of the carbon-ceramic composite nozzle extension.

[0051] In the present invention, it is preferably to achieve near-net shape forming of the nozzle extension through a fully carbonaceous deformation tooling control and deformation compensation technology during the manufacturing process.

[0052] In the present invention, the first high-temperature heat treatment is preferably carried out under the first tooling, and the first tooling is preferably arranged inside the carbon fiber profiling preform; the material of the first tooling is preferably a carbon material, more preferably graphite; the shape of the first tooling is similar to the shape of the ultra-thin carbon-ceramic composite nozzle extension, and the size of the first tooling is designed such that the outer surface size after expansion during the first high-temperature heat treatment reaches the inner surface size of the pre-obtained carbon fiber profiling preform. In the present invention, the size of the carbon fiber profiling preform meets the size requirements of the pre-obtained carbon fiber profiling preform after the first high-temperature heat treatment; the outer surface of the first tooling and the inner surface of the carbon fiber profiling preform reach the same size during the first high-temperature treatment, both being the inner surface size of the pre-obtained carbon fiber profiling preform.

[0053] In the present invention, the temperature of the first high-temperature treatment is preferably 1800 - 2300 °C, more preferably 2000 - 2200 °C, and most preferably 2100 °C; the holding time is preferably 0.5 - 4 hours, more preferably 2 - 3 hours, and most preferably 2 hours; the first high-temperature treatment is preferably carried out in a protective atmosphere; the protective atmosphere is preferably an inert gas, more preferably argon.

[0054] In the present invention, the chemical vapor infiltration is preferably carried out under a second tooling, and the second tooling is preferably arranged inside the product after the first high-temperature treatment; the material of the second tooling is preferably a carbon material, more preferably graphite; the shape of the second tooling is similar to the shape of the extended section of the ultra-thin carbon-ceramic composite nozzle, and the size of the second tooling is designed such that the outer surface size after expansion during chemical vapor infiltration reaches the inner surface size of the pre-obtained porous carbon-carbon nozzle extended section. In the present invention, the size of the product after the first high-temperature treatment reaches the inner surface size of the pre-obtained porous carbon-carbon nozzle extended section after chemical vapor infiltration; the outer surface of the second tooling and the inner surface of the product after the first high-temperature treatment reach the same size after chemical vapor infiltration, which is the inner surface size of the pre-obtained porous carbon-carbon nozzle extended section. Due to the different temperatures of the first high-temperature treatment and chemical vapor deposition, the expansion sizes of the toolings are different, and the sizes of the first tooling and the second tooling are also different.

[0055] In the present invention, the first tooling and the second tooling are filled inside the carbon fiber profiling preform to prevent it from deforming during the hot working process.

[0056] In the present invention, the chemical vapor infiltration is preferably carried out simultaneously under a third tooling. The third tooling is arranged outside the product after the first high-temperature treatment, and there is a gap between the third tooling and the product after the first high-temperature treatment, which is used as the gas flow channel during the chemical vapor infiltration process; the material of the third tooling is preferably a carbon material, more preferably graphite; the shape and size of the inner surface of the third tooling are designed to match the outer surface shape of the product after the first high-temperature treatment, so that the cross-sectional area of the gas flow channel between the third tooling and the product after the first high-temperature treatment is the same during the chemical vapor infiltration process; there are no special restrictions on the shape and size of the outer surface of the third tooling in the present invention. In the present invention, during the chemical vapor deposition process, the gas flows from the large inlet end to the small outlet end of the product after the first high-temperature treatment, and the cross-section of the gas passing through the gap between the third tooling and the product after the first high-temperature treatment is similar to an annulus, and the area of each annulus cross-section through which the gas passes is the same. In the present invention, the distance of the gap between the third tooling and the product after the first high-temperature treatment is preferably controlled within 20 - 90 mm, more preferably 30 - 80 mm. In the present invention, the chemical vapor infiltration (deposition) densification adopts a unidirectional infiltration method, and using the third tooling in the present invention can ensure the densification uniformity in the axial direction during the densification process of the carbon fiber preform.

[0057] In the present invention, the carbon source gas for chemical vapor infiltration is preferably a hydrocarbon gas, more preferably selected from natural gas and propylene, and most preferably propylene; the diluent gas is preferably nitrogen; the flow rate ratio of the carbon source gas to the diluent gas is preferably (2-4):1, more preferably (3-4):1; the deposition temperature is preferably 900-980 °C, more preferably 930-960 °C, and even more preferably 940-950 °C; the deposition pressure is preferably 0.6-1.5 kPa, more preferably 0.6-1.2 kPa, even more preferably 0.7-1.1 kPa, and most preferably 0.8-1.0 kPa.

[0058] In the present invention, the bulk density of the porous carbon-carbon nozzle extension blank is preferably 1.2-1.6 g / cm 3 , more preferably 1.3-1.45 g / cm 3 , and most preferably 1.35-1.4 g / cm 3 .

[0059] In the present invention, the second high-temperature treatment is preferably carried out under the fourth tooling; since the temperatures of the first high-temperature treatment and the second high-temperature treatment are the same, and the shapes and sizes of the first tooling and the fourth tooling are the same, the first tooling can be used instead of the fourth tooling; the fourth tooling is arranged inside the product after the second high-temperature treatment, and the material of the fourth tooling is preferably a carbon material, more preferably graphite.

[0060] In the present invention, the second high-temperature treatment preferably uses argon as the protective gas; the temperature of the second high-temperature treatment is preferably 1800-2300 °C, more preferably 2000-2200 °C, and most preferably 2100 °C; the heat preservation time is preferably 0.5-4 hours, more preferably 2-3 hours, and most preferably 2 hours. In the present invention, the fourth tooling is filled inside the product after the second high-temperature treatment and clamped to prevent the product from deforming during the hot processing, which is beneficial to realizing the near-net shaping of the thin-wall carbon-ceramic composite nozzle extension component and improving the overall stability of the component performance.

[0061] In the present invention, the machining refers to the mechanical machining of the outer surface and the axial end face of the porous carbon-carbon nozzle extension blank; it is preferably turning, milling and / or grinding, more preferably milling and / or grinding.

[0062] In the present invention, the reaction infiltration is preferably carried out under a fifth tooling. The fifth tooling is arranged outside the product after the second high-temperature treatment and has a gap with the product after the second high-temperature treatment. The infiltration powder (infiltrant) is filled. The gap between the second high-temperature treatment and the fifth tooling can enable the infiltrant powder to completely fill this gap after melting; the present invention has no special limitation on the shape of the fifth tooling, and the gap between the fifth tooling and the product after the second high-temperature treatment only needs to meet the filling requirements of the above-mentioned infiltrant powder. In the present invention, the gap between the product after the second high-temperature treatment and the fifth tooling is adjusted according to the powder consumption to determine the optimal filling effect and ensure the effective progress of infiltration. During the filling process, the small end of the outlet of the product after the second high-temperature treatment is at the bottom and the large end of the inlet is at the top.

[0063] In the present invention, the material of the fifth tooling is preferably a carbon material, more preferably a carbon material with surface ceramization treatment, and most preferably graphite with surface ceramization treatment. The method of ceramization treatment preferably includes:

[0064] Place Si powder under the graphite tooling, heat it, and use the reaction of Si vapor and graphite to form a SiC protective layer on the surface of the tooling.

[0065] In the present invention, the reaction infiltration is preferably also carried out under a sixth tooling. The sixth tooling is arranged inside the product after the second high-temperature treatment. Since the temperature of the reaction infiltration is close to that of the first high-temperature treatment, the shape and size of the sixth tooling are the same as those of the first tooling, and the first tooling can be used instead of the sixth tooling. The material of the sixth tooling is preferably a carbon material, and more preferably graphite.

[0066] In the present invention, the temperature of the reaction infiltration is preferably 1600 - 2300 °C, more preferably 1700 - 2200 °C, and most preferably 1800 - 2100 °C; the holding time is preferably 2 - 6 hours, more preferably 3 - 5 hours, and most preferably 4 hours; it is preferably carried out in an inert protective atmosphere, and more preferably argon; the reaction infiltration preferably adopts a unidirectional infiltration method.

[0067] In the present invention, the infiltrant of the reaction infiltration preferably includes: metal powder, or a mixture of metal powder and a compound, and the compound is a carbide of the metal powder; the metal powder is preferably selected from one or more of Si, Zr, Hf, Ti, Ta, Nb, etc.

[0068] The present invention has no special limitation on the preparation methods of the first tooling, the second tooling, the third tooling, the fourth tooling, the fifth tooling, and the sixth tooling. The carbon material can be prepared into toolings with the required shape and size by using the processing and forming methods well-known to those skilled in the art.

[0069] The present invention uses the reaction infiltration process to manufacture the carbon-ceramic composite nozzle extension section, which has the advantages of simple method, convenient operation, controllable process, low cost, short cycle, etc. The one-time introduction of the ceramic phase can reduce the thermal processing damage of the carbon-ceramic nozzle extension section caused by the multi-cycle thermal process and ensure the load-bearing performance of the carbon-ceramic nozzle extension section.

[0070] In the present invention, during the (product) finish machining, according to the product drawing, the carbon-ceramic nozzle extension section product is subjected to final machining; the machining needs to be realized by relying on machining fixtures; the machining method is preferably mainly milling and / or grinding.

[0071] In the present invention, the finish machining preferably includes the machining of the outer surface, inner surface, assembly surface, bolt holes, etc. Each machining process is preferably equipped with specific fixtures to avoid machining damage and ensure the surface accuracy of the nozzle product.

[0072] In the present invention, the manufacturing of the ultra-thin wall carbon-ceramic composite nozzle extension section is near-net size forming. During the manufacturing process, the surface deformation characteristics of the material during the hot processing are fully considered, and the post-processing amount of the product is small, which is beneficial to ensuring the continuity of the carbon fiber. The present invention focuses on realizing the near-net forming manufacturing of the ultra-thin wall carbon-ceramic composite nozzle extension section. On the basis of considering the thermal deformation characteristics of heterogeneous materials, a reasonable allowance is set for the carbon fiber preform, and deformation prevention fixtures are used for restraint, effectively reducing the processing amount and processing damage of the hard carbon-ceramic nozzle extension section.

[0073] The process flow chart for preparing the ultra-thin carbon-ceramic composite nozzle extension section in the embodiment of the present invention is as Figure 1 shown, preferably including:

[0074] Structural design and forming of the carbon fiber profile preform;

[0075] High-temperature heat treatment of the carbon fiber profile preform;

[0076] Using chemical vapor infiltration to prepare a porous carbon-carbon nozzle extension section blank;

[0077] High-temperature heat treatment and machining of the porous carbon-carbon nozzle extension section blank;

[0078] Using the reaction infiltration method to prepare a carbon-ceramic nozzle extension section blank;

[0079] Finish machining to obtain the carbon-ceramic composite nozzle extension section product.

[0080] In the present invention, for the structural design and forming of the carbon fiber profile preform, preferably, the preform structure is designed according to the specific performance requirements of the component product; the mold is designed based on the outer shape structure characteristics and forming characteristics of the component product, and the carbon fiber profile preform is formed on the mold.

[0081] In the present invention, for the high-temperature heat treatment of the carbon fiber profiling preform, it is preferably to hold and load the preform by using a fully carbonaceous deformation prevention tooling, and conduct the high-temperature heat treatment in an inert gas environment.

[0082] In the present invention, for the preparation of the porous carbon-carbon nozzle extension blank, it is preferably to hold and load the preform by using a fully carbonaceous deformation prevention tooling, and use the chemical vapor infiltration method to densify the pyrolytic carbon matrix of the carbon fiber preform; this step is stopped after the porous carbon-carbon nozzle extension blank reaches the designed density.

[0083] In the present invention, for the high-temperature heat treatment and machining of the porous carbon-carbon blank, it is preferably to conduct the high-temperature heat treatment of the porous carbon-carbon nozzle extension blank held and loaded by the fully carbonaceous deformation prevention tooling in an inert gas environment, and machine the porous carbon-carbon nozzle extension blank with a certain margin reserved based on the product size.

[0084] In the present invention, for the preparation of the carbon-ceramic nozzle extension blank, it is preferably to load the porous carbon-carbon nozzle extension by using a fully carbonaceous infiltration tooling with surface ceramization treatment, fill the infiltration powder in a predetermined space, and use the reactive infiltration method to prepare the carbon-ceramic composite nozzle extension blank.

[0085] In the present invention, for the finish machining of the (product), it is preferably to conduct the final machining of the carbon-ceramic nozzle extension product according to the product drawing with the assistance of a machining tooling.

[0086] The present invention provides a rocket engine, comprising: an ultra-thin carbon-ceramic composite nozzle extension prepared by the method described in the above technical solution.

[0087] In the present invention, the rocket can be a liquid rocket or a solid rocket, and the ultra-thin carbon-ceramic composite nozzle extension is preferably used for the nozzle extension of a rocket engine. The carbon-ceramic composite nozzle extension provided by the present invention can be applied to solid and liquid rocket engines, especially the thermal structure components of the nozzle extension of a liquid rocket engine.

[0088] The ultra-thin wall carbon-ceramic composite nozzle extension prepared by the method provided by the present invention has characteristics such as light weight, low porosity, and uniform distribution of ceramic phases, and can be applied to the nozzle extension of solid / liquid engines, especially suitable for the nozzle extension of the upper stage engine of a liquid rocket.

[0089] The manufacturing method of the ultra-thin wall carbon-ceramic composite nozzle extension provided by the present invention has characteristics such as simple method, convenient operation, controllable process, low cost, and short cycle, and is suitable for the near-net shaping of special-shaped thin-wall carbon-ceramic composites and components, providing an effective method for the efficient preparation and low-cost production of special-shaped thin-wall carbon-ceramic composite components.

[0090] Example 1

[0091] The nozzle extension of the carbon-ceramic composite material prepared in this example is of a bell-shaped structure (as Figure 2 shown), with a minimum wall thickness of 1.5 mm. The ceramic phase component is SiC, and it is manufactured by near-net shaping using a combination of the chemical vapor infiltration method and the reactive melt infiltration method. The specific method is as follows:

[0092] (1) Using satin cloth / mesh fiber as the ply structure unit, lay-up winding is carried out on a profiling mold, and the connection between plies is carried out by stitching (the stitching spacing is 5*5 mm) to obtain a carbon fiber profiling preform with a bulk density of 0.88 g / cm 3 . Among them, the allowance for the inner surface of the carbon fiber preform is set to 0.5 - 1.2 mm, the allowance for the outer surface is set to 2 mm, and the allowance for a single segment of the in-plane boundary (at both ends) is set to 10 mm.

[0093] (2) The carbon fiber profiling preform is clamped and loaded onto a profiling graphite anti-deformation tooling (the first tooling, which is set inside the carbon fiber profiling preform, and the outer surface dimension of the first tooling after expansion during the first high-temperature treatment is the same as the inner surface dimension of the carbon fiber profiling preform after expansion), and placed in a medium-frequency induction heating high-temperature furnace. High-temperature heat treatment (the first high-temperature treatment) is carried out under an argon protection atmosphere; among them, the heat treatment temperature is 2100 °C, and the holding time is 2 hours.

[0094] (3) The carbon fiber profiling preform (the second tooling, which is set inside the product after the first high-temperature treatment, and the outer surface dimension of the second tooling after expansion during chemical vapor deposition is the same as the inner surface dimension of the product after the first high-temperature treatment) clamped and loaded with the profiling graphite anti-deformation tooling after high-temperature heat treatment is placed in a chemical vapor deposition furnace, and the gas channel of the profiling graphite tooling (the third tooling, the gas channel between the third tooling and the product after the first high-temperature treatment makes the cross-sectional area of the gas passing through the gas channel the same during chemical vapor deposition) is utilized; propylene is used as the carbon source gas and nitrogen is used as the dilution gas for chemical vapor infiltration densification; among them, the propylene / nitrogen flow ratio is 3:1, the deposition temperature is 930 °C, and the deposition pressure is 0.6 - 1.0 kPa; after deposition for 150 h, a porous carbon-carbon composite nozzle extension blank with a bulk density of 1.38 g / cm 3 is obtained.

[0095] (4) The porous carbon-carbon composite nozzle extension blank together with the profiling graphite anti-deformation tooling (the first tooling) is placed in a medium-frequency induction heating high-temperature furnace, and high-temperature heat treatment (the second high-temperature treatment) is carried out under an argon protection atmosphere; among them, the heat treatment temperature is 2100 °C, and the holding time is 3 hours.

[0096] (5) Take out the porous carbon-carbon composite nozzle extension blank from the anti-deformation tooling. With the assistance of machining tooling, perform surface machining on the outer profile surface on a numerically controlled machine tool. The machining method is grinding, and the machining allowance in the thickness direction is 0.5 - 0.8 mm based on the outer profile of the preform; the machining allowance in the in-plane (end face) of the porous carbon-carbon composite nozzle extension is 1 - 2 mm.

[0097] (6) Carry out ceramicizing treatment on the profiling graphite infiltration tooling (set SiC coating, the fifth tooling). Load the porous carbon-carbon composite nozzle extension blank (with the first tooling installed inside) into the infiltration tooling (the fifth tooling). The gap between the outer profile surface of the porous carbon-carbon blank and the inside of the infiltration tooling is 7 mm; fill silicon powder with a particle size of 50 μm into the above gap space and tamp it. Then place the whole infiltration tooling in an intermediate frequency induction high-temperature furnace for reactive infiltration treatment. The infiltration temperature is 1700 °C, and the holding time is 4 hours; after the temperature in the furnace drops to room temperature, take it out of the furnace and remove the tooling to obtain a carbon-ceramic composite nozzle extension blank, and the density of this blank is about 2.21 g / cm 3 .

[0098] (7) Use machining tooling to perform finish machining on the carbon-ceramic composite nozzle extension (including inner profile surface, outer profile surface, assembly surface, and connection holes), etc. Finally, obtain a carbon-ceramic composite nozzle extension product with a bulk density of 2.18 g / cm 3 .

[0099] Perform performance testing on the in-furnace test samples of the products prepared in Example 1. The results are as follows:

[0100]

[0101]

[0102] Example 2

[0103] The carbon-ceramic composite nozzle extension prepared in this example is of a bell-shaped structure, with a minimum wall thickness of 1.5 mm. The ceramic phase component is SiC-ZrC, and it is manufactured by near-net shaping through a combination of chemical vapor infiltration method and reactive infiltration method. The specific method is as follows:

[0104] (1) Use satin cloth / mesh fiber as the ply structure unit to perform ply winding on the profiling mold, and use the stitching method for inter-ply connection (stitching spacing is 5*5 mm) to obtain a carbon fiber profiling preform with a bulk density of 0.82 g / cm 3 . Among them, the allowance for the inner profile surface of the carbon fiber preform is set to 0.5 - 1.2 mm, the allowance for the outer profile surface is set to 2 mm, and the single-segment allowance for the in-plane boundary (both ends) is set to 10 mm.

[0105] (2) The carbon fiber profiling preform is supported and loaded on a profiling graphite anti-deformation tooling (a first tooling, the first tooling is arranged inside the carbon fiber profiling preform, and the outer surface size of the first tooling after expansion during the first high-temperature treatment is the same as the inner surface size of the carbon fiber profiling preform after expansion), placed in a medium-frequency induction heating high-temperature furnace, and subjected to high-temperature heat treatment (first high-temperature treatment) under an argon protective atmosphere; wherein the heat treatment temperature is 2200°C and the insulation time is 2 hours.

[0106] (3) A carbon fiber profiling preform (a second tooling, the second tooling is arranged inside the product after the first high-temperature treatment, and the second tooling has the same outer surface size after expansion during chemical vapor deposition as the inner surface size after expansion of the product after the first high-temperature treatment) that has undergone high-temperature heat treatment and is supported and loaded with a profiling graphite anti-deformation tooling is placed in a chemical vapor deposition furnace, and a gas channel of the profiling graphite tooling is used (a third tooling, the gas channel between the third tooling and the product after the first high-temperature treatment makes the cross-sectional area of the gas passing through the gas channel during the chemical vapor deposition process the same), and chemical vapor infiltration densification is performed using propylene as the carbon source gas and nitrogen as the diluent gas; wherein the propylene / nitrogen flow ratio is 3:1, the deposition temperature is 940°C, and the deposition pressure is 0.6-1.0 kPa; after deposition for 120 hours, a volume density of 1.37 g / cm 3 A porous carbon-carbon composite nozzle extension section blank.

[0107] (4) placing the porous carbon-carbon composite nozzle extension blank together with the contoured graphite anti-deformation tooling (first tooling) in a medium frequency induction heating high-temperature furnace, and performing high-temperature heat treatment (second high-temperature treatment) under an argon protective atmosphere; wherein the heat treatment temperature is 2200° C. and the insulation time is 2 hours.

[0108] (5) The porous carbon-carbon composite nozzle extension section blank is taken out from the anti-deformation tooling, and the surface of the outer surface is machined on a CNC machine tool with the assistance of a machining tooling. The machining method is grinding, and the machining amount in the thickness direction is 0.5 to 0.8 mm based on the outer surface of the preform; the machining amount in the surface (end face) of the porous carbon-carbon composite nozzle extension section is 1 to 2 mm.

[0109] (6)Ceramify the profiling graphite infiltration tooling (set the SiC coating, the fifth tooling), load the porous carbon-carbon composite nozzle extension blank (with the first tooling inside) into the infiltration tooling (the fifth tooling), where the clearance between the outer profile of the porous carbon-carbon blank and the inside of the infiltration tooling is 5 mm; fill the above clearance space with a mixed powder of silicon powder and zirconium powder (mass ratio 4:1) and tamp it, then place the whole infiltration tooling in an intermediate frequency induction high-temperature furnace for reactive infiltration treatment, where the infiltration temperature is 2000 °C and the holding time is 4 hours. After the temperature in the furnace drops to room temperature, take it out of the furnace and remove the tooling to obtain the carbon-ceramic composite nozzle extension blank, and the density of this blank is about 2.36 g / cm 3 .

[0110] (7)Using the processing tooling, finish machine the carbon-ceramic composite nozzle extension (including the inner profile, outer profile, assembly surface and connection holes), etc., and finally obtain the carbon-ceramic composite nozzle extension product with a bulk density of 2.33 g / cm 3 .

[0111] Perform performance testing on the in-furnace test samples of the products prepared in Example 2, and the results are as follows:

[0112] Item Unit Value Test Standard Tensile Strength MPa 211 GJB 6475-2008 Flexural Strength MPa 184 GB / T 6569-2006 Shear Strength MPa 98 ASTM C1292-002 Compressive Strength MPa 427 JB / T8133.8-2013 Tensile Elastic Modulus GPa 62 GJB 6475-2008 Coefficient of Thermal Expansion (900℃) <![CDATA[1 / ℃×10 -6 > 1.58 GJB332A-2004 Thermal Conductivity (900℃) W / (m·K) 9.4 GJB1201.1-1991

[0113] Example 3

[0114] The carbon-ceramic composite nozzle extension prepared in this example is of a bell-shaped structure, with a minimum wall thickness of 1.5 mm, and the ceramic phase composition is SiC-TiC-HfC. It is manufactured by near-net shaping through a combination of chemical vapor infiltration and reactive infiltration processes. The specific method is as follows:

[0115] (1) Use twill cloth / net tire / mesh fiber as the ply structure unit to wind the ply on the profiling mold, and use the needling method to connect between the plies to obtain a carbon fiber profiling preform with a bulk density of 0.55 g / cm 3 . Wherein, the allowance for the inner profile of the carbon fiber preform is set to 0.8 - 1.5 mm, the allowance for the outer profile is set to 2 mm, and the single-segment allowance for the in-plane boundary (at both ends) is set to 10 mm.

[0116] (2) Clamp and load the carbon fiber profiling preform into the profiling graphite anti-deformation tooling (the first tooling, set the first tooling inside the carbon fiber profiling preform, and after the first high-temperature treatment, the outer profile size of the first tooling after expansion is the same as the inner profile size of the carbon fiber profiling preform after expansion), place it in an intermediate frequency induction heating high-temperature furnace, and perform high-temperature heat treatment (the first high-temperature treatment) under an argon protection atmosphere; wherein, the heat treatment temperature is 2200 °C and the holding time is 3 hours.

[0117] (3) Place the carbon fiber profiled preform (the second tooling, which is set inside the product after the first high-temperature treatment, and the outer profile size of the second tooling after expansion during chemical vapor deposition is the same as the inner profile size of the product after expansion after the first high-temperature treatment) clamped and loaded by a profiled graphite anti-deformation tooling after high-temperature heat treatment into a chemical vapor deposition furnace, and utilize the gas passage of the profiled graphite tooling (the third tooling, and the cross-sectional area of the gas passage between the third tooling and the product after the first high-temperature treatment is the same during the chemical vapor deposition process) to allow the gas during chemical vapor deposition to pass through; use propylene as the carbon source gas and nitrogen as the dilution gas for chemical vapor infiltration densification; wherein the propylene / nitrogen flow ratio is 4:1, the deposition temperature is 960 °C, and the deposition pressure is 0.8 - 1.2 kPa; after depositing for 210 h, a porous carbon-carbon composite nozzle extension blank with a bulk density of 1.32 g / cm 3 is obtained.

[0118] (4) Place the porous carbon-carbon composite nozzle extension blank together with the profiled graphite anti-deformation tooling (the first tooling) into an intermediate frequency induction heating high-temperature furnace for high-temperature heat treatment (the second high-temperature treatment) under an argon protection atmosphere; wherein, the heat treatment temperature is 2200 °C and the holding time is 3 hours.

[0119] (5) Take out the porous carbon-carbon composite nozzle extension blank from the anti-deformation tooling, and with the assistance of a machining tooling, perform surface machining on the outer profile on a numerical control machine, and the machining method is grinding, and the machining amount in the thickness direction is 0.5 - 0.8 mm based on the outer profile of the preform; the machining amount in the in-plane (end face) of the porous carbon-carbon composite nozzle extension is 1 - 2 mm.

[0120] (6) Perform ceramization treatment on the profiled graphite infiltration tooling (set an SiC coating, the fifth tooling), load the porous carbon-carbon composite nozzle extension blank (with the first tooling set inside) into the interior of the infiltration tooling, wherein the gap between the outer profile of the porous carbon-carbon blank and the interior of the infiltration tooling is 5 mm; fill the above gap space with a mixed powder of silicon powder, titanium powder and hafnium powder (mass ratio 4:1:1) and tamp it, and then place the entire infiltration tooling into an intermediate frequency induction high-temperature furnace for reactive infiltration treatment, wherein the infiltration temperature is 2200 °C and the holding time is 4 hours; after the temperature in the furnace drops to room temperature, take it out of the furnace and remove the tooling to obtain a carbon-ceramic composite nozzle extension blank, and the density of this blank is about 2.33 g / cm 3 .

[0121] (7) Utilize the machining tooling to perform finish machining on the carbon-ceramic composite nozzle extension (including the inner profile, outer profile, assembly surface and connection holes), etc., and finally obtain a carbon-ceramic composite nozzle extension product with a bulk density of 2.31 g / cm 3 .

[0122] Performance testing was carried out on the in-furnace test samples of the product prepared in Example 3, and the results are as follows:

[0123] Item Unit Value Test Standard Tensile Strength MPa 124 GJB 6475-2008 Flexural Strength MPa 153 GB / T 6569-2006 Shear Strength MPa 86 ASTM C1292-002 Compressive Strength MPa 419 JB / T8133.8-2013 Tensile Elastic Modulus GPa 45 GJB 6475-2008 Coefficient of Thermal Expansion (900℃) <![CDATA[1 / ℃×10 -6 > 1.26 GJB332A-2004 Thermal Conductivity (900℃) W / (m·K) 8.4 GJB1201.1-1991

[0124] Example 4

[0125] The carbon-ceramic composite nozzle extension prepared in this example has a bell-shaped structure with a minimum wall thickness of 1.5 mm. The ceramic phase composition is SiC-ZrC-HfC, and it is manufactured by near-net shaping using a combination of chemical vapor infiltration and reaction infiltration processes. The specific method is as follows:

[0126] (1) Using twill cloth / wire mesh / fiber grid as the ply structure unit, layering and winding are carried out on a profiling mold, and needle punching is used for inter-ply connection to obtain a carbon fiber profiling preform with a bulk density of 0.65 g / cm 3 ³. Among them, the inner surface allowance of the carbon fiber preform is set to 0.5 - 1.2 mm, the outer surface allowance is set to 2 mm, and the single-segment allowance of the in-plane boundary (both ends) is set to 10 mm.

[0127] (2) The carbon fiber profiling preform is clamped and loaded onto a profiling graphite anti-deformation tooling (the first tooling, which is set inside the carbon fiber profiling preform, and the outer surface size of the first tooling after expansion during the first high-temperature treatment is the same as the inner surface size of the carbon fiber profiling preform after expansion), and placed in a medium-frequency induction heating high-temperature furnace for high-temperature heat treatment (the first high-temperature treatment) under an argon protective atmosphere. Among them, the heat treatment temperature is 2000 °C, and the holding time is 3 hours.

[0128] (3) The carbon fiber profiling preform (the second tooling, which is set inside the product after the first high-temperature treatment, and the outer surface size of the second tooling after expansion during chemical vapor deposition is the same as the inner surface size of the product after the first high-temperature treatment) clamped and loaded with the profiling graphite anti-deformation tooling after high-temperature heat treatment is placed in a chemical vapor deposition furnace, and the gas passage of the profiling graphite tooling (the third tooling, the gas passage between the third tooling and the product after the first high-temperature treatment makes the cross-sectional area of the gas passing through the gas passage during chemical vapor deposition the same) is used to carry out chemical vapor infiltration densification with propylene as the carbon source gas and nitrogen as the dilution gas. Among them, the propylene / nitrogen flow ratio is 4:1, the deposition temperature is 950 °C, and the deposition pressure is 0.8 - 1.2 kPa; after deposition for 200 h, a porous carbon-carbon composite nozzle extension blank with a bulk density of 1.31 g / cm 3 ³ is obtained.

[0129] (4) Place the porous carbon-carbon composite nozzle extension blank together with the profiled graphite anti-deformation tooling (the first tooling) in a medium-frequency induction heating high-temperature furnace, and conduct high-temperature heat treatment (the second high-temperature treatment) under an argon protection atmosphere; among them, the heat treatment temperature is 2000 °C and the holding time is 3 hours.

[0130] (5) Remove the porous carbon-carbon composite nozzle extension blank from the anti-deformation tooling, and under the assistance of machining tooling, perform surface machining on the outer surface of the profile on a numerically controlled machine tool. The machining method is grinding, and the machining amount in the thickness direction is 0.5 - 0.8 mm based on the preformed outer profile; the machining amount of the porous carbon-carbon composite nozzle extension in the plane (end face) is 1 - 2 mm.

[0131] (6) Conduct ceramicization treatment on the profiled graphite infiltration tooling (set SiC coating, the fifth tooling), load the porous carbon-carbon composite nozzle extension blank (with the first tooling set inside) inside the infiltration tooling, where the gap between the outer profile of the porous carbon-carbon blank and the inside of the infiltration tooling is 6 mm; fill the above gap space with a mixture of silicon powder and nano-scale zirconium carbide powder and hafnium carbide powder (mass ratio 6:2:1) and vibrate it solid, then place the entire infiltration tooling in a medium-frequency induction high-temperature furnace for reactive infiltration treatment, where the infiltration temperature is 2000 °C and the holding time is 4 hours. After the temperature in the furnace drops to room temperature, take it out of the furnace and remove the tooling to obtain a carbon-ceramic composite nozzle extension blank, and the density of this blank is about 2.38 g / cm 3 .

[0132] (7) Use the machining tooling to perform finish machining on the carbon-ceramic composite nozzle extension (including the inner profile, outer profile, assembly surface, and connection holes), etc., and finally obtain a carbon-ceramic composite nozzle extension product with a bulk density of 2.35 g / cm 3 .

[0133] Perform performance testing on the in-furnace test specimens of the products prepared in Example 4, and the results are as follows:

[0134]

[0135]

[0136] Example 5

[0137] The carbon-ceramic composite nozzle extension prepared in this example is of a bell-shaped structure, with a minimum wall thickness of 1.5 mm. The ceramic phase component is SiC-TaC, and it is manufactured by near-net shaping through a combination of chemical vapor infiltration method and reactive infiltration method. The specific method is as follows:

[0138] (1) Using twill fabric / felt / grid fiber as the layup structure unit, layup winding is carried out on the profiling mold, and the connection between layups is carried out by needling to obtain a carbon fiber profiling preform with a bulk density of 0.58 g / cm 3 ; among them, the inner surface allowance of the carbon fiber preform is set to 0.5 - 1.2 mm, the outer surface allowance is set to 2 mm, and the single-segment allowance of the in-plane boundary (both ends) is set to 10 mm.

[0139] (2) Clamp and load the carbon fiber profiling preform on the profiling graphite anti-deformation tooling (the first tooling, the first tooling is set inside the carbon fiber profiling preform, and the outer surface size after expansion during the first high-temperature treatment is the same as the inner surface size of the carbon fiber profiling preform after expansion), place it in the intermediate frequency induction heating high-temperature furnace, and carry out high-temperature heat treatment (the first high-temperature treatment) under an argon protection atmosphere; among them, the heat treatment temperature is 2100 °C and the holding time is 3 hours.

[0140] (3) Place the carbon fiber profiling preform (the second tooling, the second tooling is set inside the product after the first high-temperature treatment, and the outer surface size after expansion during chemical vapor deposition is the same as the inner surface size of the product after the first high-temperature treatment) clamped and loaded with the profiling graphite anti-deformation tooling in the chemical vapor deposition furnace, and utilize the gas channel of the profiling graphite tooling (the third tooling, the gas channel between the third tooling and the product after the first high-temperature treatment enables the cross-sectional area of the gas passing through during chemical vapor deposition to be the same), and carry out chemical vapor infiltration densification with propylene as the carbon source gas and nitrogen as the dilution gas; among them, the propylene / nitrogen flow ratio is 3:1, the deposition temperature is 940 °C, and the deposition pressure is 0.8 - 1.2 kPa; after deposition for 300 h, a porous carbon-carbon composite nozzle extension blank with a bulk density of 1.42 g / cm 3 is obtained.

[0141] (4) Place the porous carbon-carbon composite nozzle extension blank together with the profiling graphite anti-deformation tooling (the first tooling) in the intermediate frequency induction heating high-temperature furnace, and carry out high-temperature heat treatment (the second high-temperature treatment) under an argon protection atmosphere; among them, the heat treatment temperature is 2100 °C and the holding time is 3 hours.

[0142] (5) Take out the porous carbon-carbon composite nozzle extension blank from the anti-deformation tooling, and with the assistance of the machining tooling, carry out surface machining of the outer surface on the numerical control machine. The machining method is grinding, and the machining amount in the thickness direction is 0.5 - 0.8 mm based on the outer surface of the preform; the machining amount of the porous carbon-carbon composite nozzle extension in the in-plane (end face) is 1 - 2 mm.

[0143] (6)Ceramify the profiling graphite infiltration tooling (set the SiC coating, the fifth tooling), load the porous carbon-carbon composite nozzle extension blank (with the first tooling inside) into the interior of the infiltration tooling, where the clearance between the outer profile of the porous carbon-carbon blank and the interior of the infiltration tooling is 7 mm; fill the above clearance space with a mixed powder of silicon powder and tantalum powder (mass ratio 5:1) and tamp it, then place the entire infiltration tooling in an intermediate frequency induction high-temperature furnace for reactive infiltration treatment, where the infiltration temperature is 2100 °C and the holding time is 3 hours; after the temperature in the furnace drops to room temperature, take it out of the furnace and remove the tooling to obtain a carbon-ceramic composite nozzle extension blank, and the density of this blank is about 2.19 g / cm 3 .

[0144] (7)Using the processing tooling, perform finish machining (including the inner profile, outer profile, assembly surface, and connection holes, etc.) on the carbon-ceramic composite nozzle extension, and finally obtain a carbon-ceramic composite nozzle extension product with a bulk density of 2.16 g / cm 3 .

[0145] Perform performance testing on the in-furnace test samples of the product prepared in Example 5, and the results are as follows:

[0146] Item Unit Value Test Standard Tensile Strength MPa 114 GJB 6475-2008 Flexural Strength MPa 126 GB / T 6569-2006 Shear Strength MPa 85 ASTM C1292-002 Compressive Strength MPa 372 JB / T8133.8-2013 Tensile Elastic Modulus GPa 46 GJB 6475-2008 Coefficient of Thermal Expansion (900℃) <![CDATA[1 / ℃×10 -6 > 1.37 GJB332A-2004 Thermal Conductivity (900℃) W / (m·K) 9.3 GJB1201.1-1991

[0147] The present invention provides a manufacturing method for an ultra-thin wall carbon-ceramic composite nozzle extension, which has the characteristics of simple method, convenient operation, process controllability, low cost, short cycle, etc., and is suitable for near-net shaping of special-shaped thin-wall carbon-ceramic composites and components, providing an effective method for the efficient preparation and low-cost production of special-shaped thin-wall carbon-ceramic composite components.

[0148] Although the present invention has been described and illustrated with reference to specific embodiments of the present invention, these descriptions and illustrations do not limit the present invention. Those skilled in the art can clearly understand that various changes can be made without departing from the true spirit and scope of the present invention as defined by the appended claims, so as to adapt a specific situation, material, material composition, substance, method, or process to the objectives, spirit, and scope of this application. All such modifications are intended to be within the scope of the appended claims herein. Although the methods disclosed herein have been described with reference to specific operations performed in a specific order, it should be understood that these operations can be combined, subdivided, or reordered without departing from the teachings of the present invention to form equivalent methods. Therefore, unless specifically indicated herein, the order and grouping of operations are not limitations of this application.

Claims

1. A preparation method of an ultra-thin carbon-ceramic composite nozzle extension section, characterized in that Including: (1) Using satin cloth / mesh fiber as the ply structure unit, layup winding is carried out on the profiling mold, and the connection between plies is carried out by stitching. The stitching spacing is 5*5 mm, and a carbon fiber profiling preform with a bulk density of 0.82 g / cm 3 is obtained; wherein, the inner surface allowance of the carbon fiber preform is set to 0.5~1.2 mm, the outer surface allowance is set to 2 mm, and ±45° mesh fibers with a certain tension are introduced inside the ply structure unit; (2) Clamp and load the carbon fiber profiled preform onto the profiled graphite anti-deformation tooling, place it in a medium-frequency induction heating high-temperature furnace, and conduct high-temperature heat treatment under an argon protection atmosphere; wherein, the heat treatment temperature is 2200 °C and the heat preservation time is 2 hours; the profiled graphite anti-deformation tooling is arranged inside the carbon fiber profiled preform, and the outer surface dimension of the profiled graphite anti-deformation tooling after expansion during high-temperature heat treatment is the same as the inner surface dimension of the carbon fiber profiled preform after expansion; (3) Place the carbon fiber profiled preform that has undergone high-temperature heat treatment and is clamped and loaded with a profiled graphite anti-deformation tooling into a chemical vapor deposition furnace. The profiled graphite tooling is arranged outside the carbon fiber profiled preform. Using the gas channels of the profiled graphite tooling, chemical vapor infiltration densification is carried out with propylene as the carbon source gas and nitrogen as the dilution gas. Among them, the propylene / nitrogen flow ratio is 3:1, the deposition temperature is 940 °C, and the deposition pressure is 0.6 - 1.0 kPa. After depositing for 120 h, a porous carbon-carbon composite nozzle extension blank with a bulk density of 1.37 g / cm 3 is obtained; the gas channels between the profiled graphite tooling and the carbon fiber profiled preform that has undergone high-temperature heat treatment and is clamped and loaded with the profiled graphite anti-deformation tooling make the cross-sectional areas of the gas passing through the gas channels during the chemical vapor deposition process the same; the outer profile dimensions of the profiled graphite anti-deformation tooling after expansion during chemical vapor deposition are the same as the inner profile dimensions of the carbon fiber profiled preform that has undergone high-temperature heat treatment and is clamped and loaded with the profiled graphite anti-deformation tooling after expansion; (4) Place the porous carbon-carbon composite nozzle extension blank together with the profiled graphite anti-deformation tooling in a medium-frequency induction heating high-temperature furnace, and conduct high-temperature heat treatment under an argon protection atmosphere, wherein the heat treatment temperature is 2200 °C and the heat preservation time is 2 hours; (5) Take out the porous carbon-carbon composite nozzle extension blank from the profiled graphite anti-deformation tooling, and conduct surface machining of the outer surface on a numerically controlled machine tool with the assistance of machining tooling. The machining method is grinding, and the machining amount in the thickness direction is 0.5 - 0.8 mm based on the outer surface of the preform; (6) Carry out ceramization treatment on the profiling graphite infiltration tooling, and load the porous carbon-carbon composite nozzle extension blank with the profiling graphite anti-deformation tooling inside into the interior of the infiltration tooling. The gap between the outer profile surface of the porous carbon-carbon composite nozzle extension blank and the interior of the profiling graphite infiltration tooling is 5 mm; fill the above gap space with a mixed powder of silicon powder and zirconium powder with a mass ratio of 4:1 and tamp it, and then place the entire infiltration tooling in an intermediate frequency induction high-temperature furnace for reactive infiltration treatment. The infiltration temperature is 2000 °C and the holding time is 4 hours; after the temperature in the furnace drops to room temperature, take it out of the furnace and remove the tooling to obtain a carbon-ceramic composite nozzle extension blank with a density of 2.36 g / cm 3 ; (7) Using a processing tooling, the carbon-ceramic composite nozzle extension section is finely processed to finally obtain a carbon-ceramic composite nozzle extension section product with a bulk density of 2.33 g / cm 3 ³.

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