Method and device for preparing micro-positive pressure impregnated Cu-C / C composite material by active cooling

Abstract

The application discloses a kind of active cooling type Cu-C / C composite material micro-positive pressure cycle impregnation preparation method and micro-positive pressure cycle impregnation device thereof, micro-positive pressure cycle impregnation preparation method includes copper-loaded polydopamine nano / micron capsule preparation, micro-positive pressure cycle impregnation and carbonization-graphitization;Micro-positive pressure cycle impregnation device is used for the micro-positive pressure cycle impregnation of C / C composite material, including storage bucket, impregnation barrel and vacuum pump.The application uses special copper-loaded polydopamine nano / micron capsule as solute, furan resin is solvent to impregnate composite C / C composite material, this method introduces metal copper into C / C composite material framework under normal temperature, micro-positive pressure condition, reduces C / C composite material production cycle, improves resin use and impregnation efficiency, improves product performance, reduces cost.The active cooling type Cu-C / C composite material prepared by the method of the application has the advantages of high strength, large modulus, high stress resistance, good heat resistance and good ablation resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of C / C composite ceramic material forming, in particular to a kind of active cooling type Cu-C / C composite material micro-positive pressure cycle impregnation preparation method and device. BACKGROUND

[0002] With the update iteration of aerospace technology, solid rocket engine also needs to maintain the basic state of low ablation and high temperature resistance in extremely harsh environment. C / C throat liner, as a key material of solid rocket engine, is prepared by carbon fiber through different weaving methods, and then through gas phase deposition or liquid phase impregnation, carbonization, graphitization, finishing and other process methods. Among them, gas phase deposition or resin impregnation is the most important process in the production process of C / C composite material. The impregnation efficiency of conventional liquid phase resin impregnation is affected by impregnation rate, and the production cycle is long without the aid of pressure. Moreover, after the resin is impregnated, high-temperature carbonization is needed. In the process of high-temperature carbonization, the volatilization of low-carbon hydrocarbon volatiles such as methane and carbon monoxide produced by impregnating agent will also cause the composite material to have a large volume shrinkage and become a porous structure, affecting its performance, especially the combination of resin carbon and matrix parts. In addition, the conventional liquid phase impregnation is difficult to achieve the purpose of improving the heat resistance and low ablation of C / C composite material.

[0003] In view of the long cycle, poor product performance and high cost of the existing resin impregnation process, it is urgent to provide a new process to improve the impregnation efficiency, improve the performance of C / C composite material products and reduce the cost. SUMMARY

[0004] In order to overcome the above technical deficiencies, the present application provides an active cooling type Cu-C / C composite material micro-positive pressure cycle impregnation preparation method and device, which solves the problems of long cycle of resin impregnation process and poor heat resistance and ablation resistance of products, so as to improve the impregnation efficiency of C / C composite material and the performance of products, and reduce the cost.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] An active cooling type Cu-C / C composite material micro-positive pressure cycle impregnation preparation method, comprising the following steps:

[0007] 1) Copper-loaded polydopamine nano / micron capsule preparation: take nano copper powder and hydrochloric acid dopamine in a weight ratio of 1-2:4, add Tris-HCl solution, mix, stir and react, and freeze-dry to obtain copper-loaded polydopamine nano / micron capsules;

[0008] 2) Micro-positive pressure cycle impregnation:

[0009] Composite resin preparation: the copper-loaded polydopamine nano / micro capsules are mixed with furan resin at a mass ratio of 1:18-23, and stirring is performed to obtain the composite resin;

[0010] Vacuumizing: the C / C composite material is placed in the impregnation barrel, and vacuumizing is performed;

[0011] Micro-positive pressure cyclic impregnation: the composite resin prepared is introduced into the impregnation barrel containing the C / C composite material, and N2 is introduced to maintain a micro-positive pressure state for 20-30 min for impregnation treatment, and then the N2 is discharged, the composite resin is extracted, and one impregnation process is completed; the extracted composite resin is introduced into the impregnation barrel containing the C / C composite material for the next impregnation process, and the cyclic impregnation process is repeated, and the cyclic impregnation time is controlled to be 6-8 h;

[0012] 3) Carbonization-graphitization:

[0013] The C / C composite material after micro-positive pressure cyclic impregnation is subjected to carbonization-graphitization treatment in a graphitization furnace; in the carbonization-graphitization treatment process, the temperature is first increased to 800-1000℃, and the temperature is maintained for 100±20 min, and in the temperature maintaining process, a protective gas is introduced to a micro-positive pressure, the pressure is maintained, then the temperature is increased to 1600-1800℃, and the temperature is maintained for 100±10 min, then the temperature is increased to 1900-2300℃, and the temperature is maintained for 150±10 min, finally the pressure is released and cooled to below 50℃, and the active cooling type Cu-C / C composite material is obtained.

[0014] Preferably, in the step 1), the stirring speed is 700-1200 rpm, the reaction temperature is controlled to be 25-35℃, the reaction pressure is controlled to be 250-350 Pa, and the reaction time is controlled to be 25-35 h; the temperature for freeze drying is below -20℃, and the freeze drying time is 24-48 h.

[0015] Preferably, in the composite resin preparation process of the step 2), the stirring speed is 1000-1200 rpm, and the stirring time is 2-4 h.

[0016] Preferably, in the step 2), the mass ratio of the copper-loaded polydopamine nano / micro capsules to the furan resin is 1:20.

[0017] Preferably, in the step 2), the temperature in the micro-positive pressure cyclic impregnation process is 20-25℃, and the pressure in the impregnation barrel is maintained at 0.1-0.3 MPa.

[0018] Preferably, in the step 3), the temperature increasing time for increasing the temperature to 800-1000℃ is controlled to be 400-800 min, the temperature increasing time for increasing the temperature to 1600-1800℃ is controlled to be 400-600 min, and the temperature increasing time for increasing the temperature to 1900-2300℃ is controlled to be 100-200 min.

[0019] Preferably, in the step 3), the protective gas is argon, the filling flow is 1-3 L / min, and the micro-positive pressure is 3-5 KPa.

[0020] A micro-positive pressure circulating impregnation device specially designed for the preparation method comprises a closed storage barrel for storing the composite resin and a closed impregnation barrel for impregnating the C / C composite material, the top of the storage barrel is sealingly connected with the top of the impregnation barrel through a resin feeding pipeline, and the bottom of the storage barrel is sealingly connected with the bottom of the impregnation barrel through a resin discharging pipeline; the top of the storage barrel is provided with a first exhaust port connected with a first vacuum pump through an exhaust pipeline; the top of the impregnation barrel is provided with a second exhaust port connected with a second vacuum pump through an exhaust pipeline; and the top of the impregnation barrel is further provided with a nitrogen inlet connected with a nitrogen pump through a suction pipeline; by controlling the first vacuum pump, the second vacuum pump and the nitrogen pump, the composite resin can be circulated between the storage barrel and the impregnation barrel.

[0021] Preferably, the impregnation barrel is provided with an impregnation basket for conveying the C / C composite material from outside the impregnation barrel into the impregnation barrel for impregnation treatment.

[0022] Preferably, the resin feeding pipeline is provided with a resin feeding switch, the resin discharging pipeline is provided with a resin discharging switch, the first vacuum pump and the first exhaust port are provided with a first filter, and the second vacuum pump and the second exhaust port are provided with a second filter.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] The active cooling type Cu-C / C composite material micro-positive pressure cycle impregnation preparation method designed by the application uses the special copper-loaded polydopamine nano / micron capsule as solute, and furan resin as solvent for impregnation and compounding, without using impregnating agent, thereby avoiding the influence of the impregnating agent on the combination of the resin carbon and the matrix product, and solving the uniformity problem of the composite resin compounding process. The amino group of the polydopamine can form a hydrogen bond with the oxygen atom of the furan, and the copper-loaded polydopamine nano / micron capsule can be well dispersed in the resin, thereby solving the dispersion problem of the copper metal in the organic resin and enabling the copper metal to be uniformly distributed in the C / C composite material. During the matrix impregnation, the nitrogen atom in the cyano group of the polyacrylonitrile fiber matrix and the amino group of the polydopamine can also form a dynamic chemical bond-hydrogen bond, thereby increasing the proportion of the copper-loaded polydopamine nano / micron capsule attached to the matrix carbon fiber pores, and increasing the proportion of the copper metal in the matrix carbon fiber pores. The copper metal is introduced into the C / C composite material framework under the condition of normal temperature and micro-positive pressure, without high pressure treatment, thereby reducing the production difficulty and production cost compared with the existing high pressure copper infiltration process. The cycle impregnation accelerates the compounding of the C / C composite material, shortens the compounding time, reduces the C / C composite material production cycle, reduces the production difficulty, and improves the resin use and impregnation efficiency.

[0025] The application solves the problem of long-time high-temperature resistance of the C / C composite material, and the copper metal framework introduced by the application improves the high-temperature resistance of the C / C composite material. During the flight process, the copper is preferentially reacted into copper oxide, the copper oxide can'sweat' sublimate to take away heat and actively cool the temperature around the throat liner, thereby improving the heat resistance of the C / C composite material. Compared with the pure C / C material, the active cooling type double-matrix Cu-C / C composite material prepared by the application has high strength, large modulus, high stress resistance, good heat resistance and good ablation resistance. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The figure is a structure diagram of the micro-positive pressure cycle impregnation device in the specific embodiment of the application.

[0027] The labels of the components in the figure are as follows: a storage barrel 1 (including a first exhaust port 11), an impregnation barrel 2 (including a nitrogen inlet 21, a second exhaust port 22 and an impregnation basket 23), a glue feeding pipeline 3 (including a resin inlet switch 31), a glue discharging pipeline 4 (including a resin outlet switch 41), a numerical control display control box 5, a first vacuum pump 6, a second vacuum pump 7, a nitrogen pump 8, a first filter 9 and a second filter 10. DETAILED DESCRIPTION

[0028] In order to better explain the application, the main content of the application is further illustrated by combining the figures and specific embodiments below, but the content of the application is not limited to the following embodiments.

[0029] AsFigure 1 As shown, the micro-positive pressure circulation impregnation device described in the embodiment has a closed storage barrel 1 for storing composite resin and a closed impregnation barrel 2 for C / C composite material impregnation. The closed structure of the storage barrel 1 and the impregnation barrel 2 can specifically adopt the barrel cover and bolt gasket sealing form. The top of the storage barrel 1 is sealingly connected with the top of the impregnation barrel 2 through a resin feeding pipeline 3, and the bottom of the storage barrel 1 is sealingly connected with the bottom of the impregnation barrel 2 through a resin discharging pipeline 4. A first exhaust port 11 is arranged at the top of the storage barrel 1, and the first exhaust port 11 is connected with a first vacuum pump 6 through an exhaust pipeline. A second exhaust port 22 is arranged at the top of the impregnation barrel 2, and the second exhaust port 22 is connected with a second vacuum pump 7 through an exhaust pipeline. A nitrogen inlet 21 is further arranged at the top of the impregnation barrel 2, and the nitrogen inlet 21 is connected with a nitrogen pump 8 through an air suction pipeline. By controlling the first vacuum pump 6, the second vacuum pump 7 and the nitrogen pump 8, the composite resin can be circulated between the storage barrel 1 and the impregnation barrel 2. More specifically, an impregnation basket 23 is arranged in the impregnation barrel 2, and the impregnation basket 23 is used to transport C / C composite material from outside the impregnation barrel 2 into the impregnation barrel 2 for impregnation treatment. In addition, a resin feeding switch 31 is arranged on the resin feeding pipeline 3, and a resin discharging switch 41 is arranged on the resin discharging pipeline 4. A first filter 9 is arranged between the first vacuum pump 6 and the first exhaust port 11, and a second filter 10 is arranged between the second vacuum pump 7 and the second exhaust port 22. The first filter 9 and the second filter 10 are respectively used to prevent the resin from entering, so as to ensure that the first vacuum pump 6 and the second vacuum pump 7 will not be damaged due to the inflow of the resin.

[0030] The micro-positive pressure circulation impregnation device is preferably operated through a numerical control display control box 5. An automatic operation panel is arranged on the numerical control display control box 5, which is used to control the resin feeding switch 31, the resin discharging switch 41, the first vacuum pump 6, the second vacuum pump 7 and the nitrogen pump 8. Such numerical control part is prior art, and will not be described in detail here.

[0031] The micro-positive pressure circulation impregnation device is controlled by an automatic production line in the embodiment, which realizes manualization, reduces manual input, liberates productive forces, improves work efficiency, adopts an intelligent operation system, has a simple and easy-to-grasp operation method, has a high safety factor of preparation process, and has an emergency stop alarm function of automatic control system to automatically monitor temperature and pressure changes in the reaction process at any time.

[0032] The active cooling type Cu-C / C composite material micro-positive pressure circulation impregnation preparation method using the micro-positive pressure circulation impregnation device includes the following steps:

[0033] 1) Preparation of copper-loaded polydopamine nano / micron capsules

[0034] In a 1L high-pressure reactor, 40g of dopamine hydrochloride and 600mL of Tris-HCl solution (10mM, pH=8.5) were added, and after stirring for 20min, 10-20g of copper nanometer powder was added, and the reaction was stirred, and the rotation speed was controlled at 700-1200rpm during the reaction process; the reaction temperature was controlled at 25-35℃, and the reaction pressure was controlled at 250-350Pa; the reaction time was controlled at 25-35h, and after the reaction was completed, it was frozen in a-20℃ refrigerator for 1d-2d, and then taken out and placed in a freeze dryer for freeze-drying to obtain copper-loaded polydopamine nanometer / micron capsules.

[0035] 2) Copper-loaded polydopamine nanometer / micron capsule / furan resin micro-positive pressure cyclic impregnation

[0036] Composite resin preparation: The prepared copper-loaded polydopamine nanometer / micron capsules were placed in a reaction kettle with furan resin at a mass ratio of 1:20, and the stirring speed was controlled at 1000-1200rpm during the stirring process, and the stirring time was 2-4h.

[0037] Vacuumizing: According to the size of the C / C composite material, select a suitable impregnation barrel 2, pour the copper-loaded polydopamine nanometer / micron capsules / furan resin into the storage barrel 1, and check and record it once. Keep the composite resin in the storage barrel 1 at 20-25℃. Place the standby C / C composite material in the impregnation basket 23 and gently put it into the impregnation barrel 2, close the barrel cover, and evenly tighten the bolts according to the diagonal method, requiring uniform gap and reliable sealing between the sealing surfaces. After starting the second vacuum pump 7, vacuumize the impregnation barrel 2.

[0038] Micro-positive pressure cyclic impregnation: Vacuumize the impregnation barrel 2, open the resin inlet switch 31, and close the resin outlet switch 41, so that the composite resin is sucked into the impregnation barrel 2 from the top to the bottom through the resin feeding pipe 3 until the composite resin liquid level in the storage barrel 1 is lowered to the minimum, and then the resin inlet switch 31 is closed, and the second vacuum pump 7 is closed. Start the nitrogen gas pump 8, and blow N2 into the impregnation barrel 2 through the nitrogen gas pump 8 to maintain a micro-positive pressure state of 0.1-0.3MPa for 20-30min. Then open the first vacuum pump 6 and the resin outlet switch 41, discharge N2 and draw the composite resin back into the storage barrel 1 from the bottom to the top through the resin discharging pipe 4, and close the resin outlet switch 41 to complete one impregnation process. The cyclic impregnation process is repeated for 6-8h. After completion, the composite resin is drawn back into the storage barrel 1, the impregnation barrel 2 is vented to room pressure, and the impregnated C / C composite material is taken out.

[0039] 3) Carbonization-graphitization

[0040] The impregnated C / C composite material is placed in a high-temperature graphitization furnace, a numerical control panel is started to set a temperature rising program, the temperature is raised to 800-1000℃ in 400-800 min, the temperature is kept for 100±20 min, the temperature is raised to 1600-1800℃ in 400-600 min, the temperature is kept for 100±10 min, the temperature is raised to 1900-2300℃ in 100-200 min, and the temperature is kept for 150±10 min. Argon is filled in during the first stage of keeping the temperature, the gas flow is 1-3 L / min, and the furnace is kept at a slight positive pressure (3-5 KPa). The pressure in the furnace is kept at 3-5 KPa until the end of the temperature rising. After the end of the temperature rising, the furnace is cooled to below 50℃, and the product is taken out.

[0041] Other parts not described belong to the prior art.

Claims

1. A method for preparing Cu-C / C composite materials by active cooling under micro-positive pressure cyclic impregnation, characterized in that: Includes the following steps: 1) Preparation of copper-loaded polydopamine nano / micro capsules: Take nano-sized copper powder and dopamine hydrochloride in a weight ratio of 1-2:4, add Tris-HCl solution, mix, stir and react, freeze dry to obtain copper-loaded polydopamine nano / micro capsules; 2) Micro-positive pressure cyclic impregnation: Preparation of composite resin: Take the copper-loaded polydopamine nano / micro capsules and mix them with furan resin at a mass ratio of 1:18-23, and stir to obtain composite resin; Vacuuming: Place the C / C composite material into the impregnation tank and vacuum it; Micro-positive pressure cyclic impregnation: The prepared composite resin is introduced into the impregnation tank containing C / C composite material, and N2 is introduced. The micro-positive pressure is maintained for 20-30 minutes for impregnation treatment. Then, the N2 is discharged and the composite resin is extracted to complete one impregnation process. The extracted composite resin is then added back into the impregnation tank containing C / C composite material for the next impregnation process. The impregnation process is repeated, and the cyclic impregnation time is controlled at 6-8 hours. 3) Carbonization-graphitization: The C / C composite material after micro-positive pressure cyclic impregnation was subjected to carbonization-graphitization treatment in a graphitization furnace. During the carbonization-graphitization treatment, the temperature was first raised to 800-1000℃ and held for 100±20min. During the holding process, a protective gas was introduced to micro-positive pressure and the pressure was maintained. Then, the temperature was raised to 1600-1800℃ and held for 100±10min. Next, the temperature was raised to 1900-2300℃ and held for 150±10min. Finally, the pressure was released and cooled to below 50℃, and the material was taken out to obtain an actively cooled Cu-C / C composite material.

2. The method for preparing Cu-C / C composite material by active cooling under micro-positive pressure cyclic impregnation according to claim 1, characterized in that: In step 1), the stirring speed is 700-1200 rpm, the reaction temperature is controlled at 25-35℃, the reaction pressure is controlled at 250-350 Pa, and the reaction time is controlled at 25-35 h; the freeze-drying temperature is below -20℃, and the freeze-drying time is 24-48 h.

3. The method for preparing Cu-C / C composite materials by active cooling under micro-positive pressure cyclic impregnation according to claim 1, characterized in that: In the preparation of the composite resin in step 2), the stirring speed is 1000-1200 rpm and the stirring time is 2-4 h.

4. The method for preparing Cu-C / C composite material by active cooling micro-positive pressure cyclic impregnation according to claim 1, characterized in that: In step 2), the mass ratio of copper-loaded polydopamine nano / microcapsules to furan resin is 1:

20.

5. The method for preparing Cu-C / C composite materials by active cooling micro-positive pressure cyclic impregnation according to any one of claims 1-4, characterized in that: In step 2), the temperature of the micro-positive pressure cyclic impregnation process is 20-25℃, and the pressure inside the impregnation tank is maintained at 0.1-0.3MPa.

6. The method for preparing Cu-C / C composite material by active cooling under micro-positive pressure cyclic impregnation according to claim 1, characterized in that: In step 3), the heating time is controlled to 400-800 min for heating to 800-1000℃, 400-600 min for heating to 1600-1800℃, and 100-200 min for heating to 1900-2300℃.

7. The method for preparing Cu-C / C composite materials by active cooling under micro-positive pressure cyclic impregnation according to claim 1 or 6, characterized in that: In step 3), the protective gas is argon, and the flow rate is 1-3 L / min; the micro-positive pressure is 3-5 KPa.

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