A method of manufacturing a liquid rocket engine faceplate

Abstract

This invention discloses a method for preparing a liquid rocket engine panel, belonging to the field of aero-rocket engine injector technology. The method includes: S1 alloy powder preparation, where CuCrZr alloy atomized powder and Cu-W composite powder are dried and subjected to ultrasonic vibration treatment for later use; S2 laser printing, where the injector panel is prepared using laser printing; S3 heat treatment, where heat treatment improves panel performance; S4 machining, where the panel surface is machined; S5 cold spraying, where an alloy coating is prepared; and S6 surface modification, where the surface is remelted using laser printing. This invention provides a method for preparing a liquid rocket engine panel, which produces injector panels with higher strength, better heat dissipation, and improved service life.

Description

Technical Field

[0001] This invention relates to the field of aero-rocket engine technology, specifically to a method for preparing a liquid rocket engine injector panel. Background Technology

[0002] The injector is a crucial component of a rocket engine. It's a fundamental component used to uniformly inject and atomize fuel and oxidizer in a specific ratio for complete combustion. Its purpose is to ensure the complete combustion of oxidizer and fuel, significantly impacting the stability of the rocket engine. The injector panel is equipped with numerous nozzles through which fuel and oxidizer are continuously injected into the combustion chamber for mixing and combustion. For example, in a hydrogen-oxygen engine, the hot side of the injector panel can reach temperatures of 3200°C, while the cold side, containing the hydrogen medium, has a temperature of -150°C. This complex operating environment places high demands on the materials used in the injector panel. Some scholars believe that relying solely on alloying of metallic materials without advanced sweating cooling technology is insufficient.

[0003] Currently, sweating cooling materials suffer from complex processes, requiring the preparation of porous material components and the exploration of cumbersome welding techniques. The overall process is complex, the production cycle is long, and it is limited by equipment size and complex welding processes. In addition, the obtained materials have problems such as uneven W distribution, limited improvement in high temperature resistance and heat dissipation capacity. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for preparing a liquid rocket engine panel.

[0005] The technical solution of this invention is: a method for preparing a liquid rocket engine injector panel, comprising the following steps:

[0006] S1. Alloy powder preparation: The CuCrZr alloy atomized powder and Cu-W composite powder are dried, cooled, and ultrasonically vibrated, and then sieved to obtain pretreated CuCrZr alloy powder and pretreated Cu-W composite powder; a 270-mesh sieve is used for sieving.

[0007] S2. Laser Printing: Import the drawn 3D model into the laser printer, fill it with the pre-treated CuCrZr alloy powder, place the base plate, install the scraper, and then evacuate the laser selective melting equipment to a vacuum degree of 3-5 Pa. Then, argon gas is introduced as a protective gas. The powder is evenly spread to the laser processing area by the scraper, and printed layer by layer according to the set printing parameters to obtain a semi-finished CuCrZr panel.

[0008] S3. Heat treatment: The semi-finished CuCrZr panel obtained in step S2 is subjected to vacuum heat treatment. The vacuum heat treatment temperature is 420-500℃, the heating rate is 9-11℃ / min, the holding time is 2-5h, and after the holding time is completed, it is cooled to 50-100℃ in the furnace and then removed from the furnace.

[0009] S4. Machining: Machining the surface of the semi-finished CuCrZr panel to make the surface roughness Ra≤1.6μm;

[0010] S5. Cold spraying: The pretreated Cu-W composite powder is loaded into the powder feeder and sprayed onto the semi-finished CuCrZr panel to obtain a panel with a Cu-W coating.

[0011] S6. Surface modification: The panel with Cu-W coating obtained in step S5 is placed into a laser printing device for surface remelting to obtain a finished injector panel that meets the requirements.

[0012] Furthermore, the CuCrZr alloy atomized powder comprises the following components by mass ratio: Cr: 0.5-1.2%, Zr: 0.03-0.3%, Fe≤0.08%, Si≤0.1%, with the balance being Cu; the Cu-W mixed powder comprises the following components by mass ratio: Co: 0.1-0.3%, RE: 0.3-2%, Cu: 38-41%, with the balance being W.

[0013] Note: The composition of the CuCrZr alloy atomized powder and Cu-W mixed powder is strictly controlled, and the prepared injector parts meet the requirements for strength, thermal conductivity, etc., which greatly improves the service life of the prepared injector panel.

[0014] Furthermore, in step S1, the drying time for the CuCrZr alloy atomized powder and the Cu-W mixed powder is 4–10 hours, and the vacuum degree in the vacuum drying oven is 10. -4 ~10 -3 Pa, the temperature inside the vacuum drying oven is 100~120℃.

[0015] Explanation: Drying reduces the moisture content of the raw material powder, preventing problems such as flowing, sticking, and collapsing during molding, thereby improving molding quality. Drying also makes the raw material powder more compact, reducing friction and resistance during molding, thus increasing molding speed. Moisture in the raw material powder evaporates during molding, which may lead to surface defects, porosity, and shrinkage. Drying can reduce the occurrence of these defects.

[0016] Furthermore, in step S1, the ultrasonic vibration treatment duration is 5–10 min, the ultrasonic vibration frequency is 35–40 kHz, and the ultrasonic vibration deviation angle is 8–10°.

[0017] Note: Ultrasonic vibration can make the molding quality more uniform and stable, thereby improving the molding quality and reliability.

[0018] Furthermore, in step S2, the printing parameters of the CuCrZr panel are set as follows: the thickness of a single layer of pretreated CuCrZr alloy powder is 0.03-0.06 mm, the scanning spacing is 0.05-0.1 mm, the power is 400-460 W, and the scanning speed is 400-1600 mm / s.

[0019] Furthermore, the specific printing method in step S2 is as follows: after each laser scan is completed, the base plate descends by one layer until printing is completed. The angle between the N+1th layer and the Nth layer scanning line in the laser scan is 45° to 90°. After processing, the surface powder needs to be recovered using a powder suction tube, the printed structure is removed, the printed structure is cut and separated from the substrate using wire cutting, and the support is removed.

[0020] Note: Scanning using the powder spreading method described above will recover the surface powder after the part is processed. The part quality obtained by the above layer-by-layer printing method is superior.

[0021] Further, in step S4, the processing of the semi-finished CuCrZr panel surface after the heat preservation is completed is as follows: when the heat preservation is completed and the surface naturally cools to 220-230°C, a treatment agent with a temperature of 70-80°C is sprayed onto the surface of the semi-finished CuCrZr panel, and mechanical polishing is performed simultaneously until the surface temperature of the semi-finished CuCrZr panel drops to 100-110°C. Then, a treatment agent with a temperature of 40-50°C is sprayed onto the surface of the semi-finished CuCrZr panel, and mechanical polishing is performed simultaneously until the surface temperature of the semi-finished CuCrZr panel drops to 50-60°C. Spraying and polishing are stopped, and a cleaning agent is used for flowing cleaning. During the cleaning process, the cleaning agent is initially at a temperature of 50-60°C, and then cooled at a rate of 4-6°C / min until the surface temperature of the semi-finished CuCrZr panel is 20-25°C, at which point the processing is complete.

[0022] Furthermore, the treatment agent is obtained by mixing nano-cerium oxide and phosphating polishing agent in a mass ratio of 1:10 to 20. The phosphating polishing agent is an acidic aqueous solution of Mn(H2PO4)2 with a pH value of 1-3.

[0023] Note: The surface processing methods described above can help improve polishing efficiency and form a uniform polishing film, which helps improve the durability and corrosion resistance of the workpiece, enhance the adhesion of subsequent alloy coatings, and thus improve the overall performance of the workpiece.

[0024] Further, in step S5, the parameters for cold spraying the Cu-Wu coating are set as follows: spraying temperature is 350-600℃, spraying gas is nitrogen, gas pressure is 4-8MPa, powder feeding rate of pretreated Cu-W composite powder is 150-350g / min, distance from nozzle to CuCrZr panel surface is 20-40mm, coating thickness is 3-5mm; and the thickness of the semi-finished CuCrZr panel is 10-20mm.

[0025] Explanation: Cold spraying is a solid-state deposition technique. The process involves preheating powder and injecting it into a high-temperature inert carrier gas. The powder is then accelerated to supersonic speed by a nozzle and impacts the substrate, causing plastic deformation and forming a dense layer that adheres firmly. Samples prepared using cold spraying technology have advantages such as low oxide content, low thermal stress, high hardness, and good bonding strength. It can also transfer the microstructure of the sprayed material to the substrate surface without altering its shape, playing a significant role in the preparation of composite materials with complex structures.

[0026] Further, in step S6, the surface modification is specifically performed as follows: the injector panel is placed on the base plate of the laser printing equipment with the coated side facing upwards, and then the laser selective melting equipment is evacuated to a vacuum degree of 3-5 Pa. Then, argon gas is introduced as a protective gas, and the surface is remelted according to the set printing parameters. The remelting parameters are set as follows: scanning distance of 0.05-0.1 mm, power of 450-500 W, and scanning speed of 1000-1600 mm / s.

[0027] Explanation: Laser remelting, also known as laser melting and solidification, is a process that uses laser heating to rapidly melt the surface of a metal, followed by rapid solidification through the metal's own heat transfer. Laser remelting can create a finer, non-equilibrium structure on the material surface, improving hardness, wear resistance, and corrosion resistance.

[0028] The beneficial effects of this invention are:

[0029] The liquid rocket engine injector panel of this invention combines 3D printing and cold spraying. The injector panel prepared by this method possesses both the high performance of laser printing and the cooling function of a sweating panel. Furthermore, cold spraying offers fast preparation speed, good process repeatability, and facilitates subsequent repairs. Compared to welding, the production cycle is shorter, saving costs. The innovation of the liquid rocket engine injector panel preparation method of this invention lies in the combination of laser remelting and cold spraying. The panel coating prepared by this method combines the advantages of mechanical bonding and metallurgical bonding, without affecting the performance of the panel substrate, while ensuring the density of the coating and resulting in a superior coating effect. This improves the wear resistance and high-temperature resistance of the material, making it suitable for liquid rocket engine injector panels. Attached Figure Description

[0030] Figure 1 This is a morphology diagram of the Cu-W60 coating on the CuCrZr surface of the present invention. Detailed Implementation

[0031] To further illustrate the methods and effects of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with experiments.

[0032] Example 1: A method for preparing a liquid rocket engine panel, comprising the following steps:

[0033] S1. Alloy powder preparation:

[0034] CuCrZr alloy atomized powder and Cu-W composite powder were respectively subjected to drying, cooling, and ultrasonic vibration treatment, followed by sieving to obtain pretreated CuCrZr alloy powder and pretreated Cu-W composite powder. The drying treatment was carried out in a vacuum drying oven at a temperature of 150℃ for 8 hours, with a vacuum degree of 10. -3 Pa; the ultrasonic vibration treatment time was 8 min, the ultrasonic vibration frequency was 38 kHz, and the ultrasonic vibration deviation angle was 9°.

[0035] CuCrZr alloy atomized powder comprises the following components by mass ratio: Cr: 0.9%, Zr: 0.1%, Fe: 0.05%, Si: 0.05%, with the balance being Cu; Cu-W mixed powder comprises the following components by mass ratio: Co: 0.2%, RE: 1%, Cu: 40%, with the balance being W.

[0036] S2, Laser Printing:

[0037] Import the drawn 3D model into the laser printer, fill it with the pre-treated CuCrZr alloy powder, place the base plate, install the scraper, then evacuate the laser selective melting equipment to a vacuum degree of 4Pa, and then introduce argon gas as a protective gas. Spread the powder evenly to the laser processing area through the scraper, and print to obtain a semi-finished CuCrZr panel.

[0038] The printing parameters for the semi-finished CuCrZr panel are set as follows: the thickness of a single layer of pre-treated CuCrZr alloy powder is 0.04 mm, the scanning spacing is 0.08 mm, the power is 420 W, and the scanning speed is 1000 mm / s.

[0039] The specific printing method is as follows: after each laser scan is completed, the base plate descends one layer until printing is completed. The angle between the N+1th layer and the Nth layer scanning line in the laser scan is 80°. After processing, the surface powder needs to be recovered using a powder suction tube, the printed structure is removed, the printed structure is cut and separated from the substrate using wire cutting, and the support is removed.

[0040] S3, Heat Treatment:

[0041] The semi-finished CuCrZr panel obtained in step S2 is subjected to vacuum heat treatment at a temperature of 450℃, a heating rate of 10℃ / min, and a holding time of 4h.

[0042] S4. Surface Finishing:

[0043] After the heat preservation is completed, the surface of the semi-finished CuCrZr panel is processed by mechanical polishing until the surface roughness Ra is 1.0μm.

[0044] S5, Cold Spray Coating:

[0045] Pretreated Cu-W composite powder is loaded into a powder feeder and sprayed onto a semi-finished CuCrZr panel to obtain a panel with a Cu-W coating. The cold spraying parameters are set as follows: spraying temperature is 450℃, spraying gas is nitrogen, gas pressure is 5MPa, powder feeding rate of pretreated Cu-W composite powder is 200g / min, distance from nozzle to CuCrZr panel surface is 30mm, coating thickness is 4mm, and the thickness of the semi-finished CuCrZr panel is 15mm.

[0046] S6, Surface remelting:

[0047] The panel with Cu-W coating obtained in step S5 is placed in a laser printing device for surface remelting to obtain the finished panel. The specific operation of surface remelting is as follows: the panel is placed on the base plate of the laser printing device with the Cu-W coating side facing up, and then the laser selective melting device is evacuated to a vacuum degree of 4 Pa. Then argon gas is introduced as a protective gas and surface remelting is performed. The parameters for surface remelting are set as follows: scanning distance of 0.08 mm, power of 480 W, and scanning speed of 1300 mm / s.

[0048] Example 2: This example differs from Example 1 in that the raw material composition is different. The CuCrZr alloy atomized powder includes the following components by mass ratio: Cr: 1.2%, Zr: 0.3%, Fe: 0.01%, Si: 0.01%, with the balance being Cu; the Cu-W mixed powder includes the following components by mass ratio: Co: 0.3%, RE: 2%, Cu: 38%, with the balance being W.

[0049] Example 3: This example differs from Example 1 in that the raw material composition is different. The CuCrZr alloy atomized powder includes the following components by mass ratio: Cr: 0.5%, Zr: 0.03%, Fe: 0.08%, Si: 0.1%, with the balance being Cu; the Cu-W mixed powder includes the following components by mass ratio: Co: 0.1%, RE: 0.3%, Cu: 41%, with the balance being W.

[0050] Example 4: This example differs from Example 1 in that the drying and ultrasonic vibration treatment parameters are different. The drying temperature is 100℃, the drying time is 4 hours, and the vacuum degree inside the vacuum drying oven is 10. -4 Pa; the ultrasonic vibration treatment time was 5 min, the ultrasonic vibration frequency was 35 kHz, and the ultrasonic vibration deviation angle was 10°.

[0051] Example 5: This example differs from Example 1 in that the drying and ultrasonic vibration treatment parameters are different. The drying temperature is 180℃, the drying time is 10 hours, and the vacuum degree inside the vacuum drying oven is 10. -3 Pa; the ultrasonic vibration treatment time was 10 min, the ultrasonic vibration frequency was 40 kHz, and the ultrasonic vibration deviation angle was 8°.

[0052] Example 6: This example differs from Example 1 in that the laser printing parameters are different. After installing the scraper, the laser selective melting equipment is evacuated to a vacuum level of 3 Pa. The pre-treated CuCrZr alloy powder is printed with a single layer thickness of 0.03 mm, a scanning spacing of 0.05 mm, a power of 380 W, and a scanning speed of 400 mm / s.

[0053] Example 7: This example differs from Example 1 in that the laser printing parameters are different. After installing the scraper, the laser selective melting equipment is evacuated to a vacuum level of 5 Pa. The pre-treated CuCrZr alloy powder is printed with a single layer thickness of 0.06 mm, a scanning spacing of 0.1 mm, a power of 460 W, and a scanning speed of 1600 mm / s.

[0054] Example 8: The difference between this example and Example 1 is that the angle between the N+1th layer and the Nth layer scan line in the laser scanning is 45°.

[0055] Example 9: The difference between this example and Example 1 is that the angle between the N+1th layer and the Nth layer scan line in the laser scanning is 90°.

[0056] Example 10: This example differs from Example 1 in that the heat treatment parameters are different. The semi-finished CuCrZr panel obtained in step S2 is subjected to vacuum heat treatment at a temperature of 420°C, a heating rate of 9°C / min, and a holding time of 2 hours.

[0057] Example 11: This example differs from Example 1 in that the heat treatment parameters are different. The semi-finished CuCrZr panel obtained in step S2 is subjected to vacuum heat treatment at a temperature of 500°C, a heating rate of 11°C / min, and a holding time of 5 hours.

[0058] Example 12: This example differs from Example 1 in that the cold spraying parameters are different. The spraying temperature is 600℃, the spraying gas is nitrogen, the gas pressure is 8MPa, the powder feeding rate of the pretreated Cu-W composite powder is 150g / min, the distance from the nozzle to the surface of the CuCrZr panel is 20mm, the coating thickness is 5mm, and the thickness of the semi-finished CuCrZr panel is 10mm.

[0059] Example 13: This example differs from Example 1 in that the cold spraying parameters are different. The spraying temperature is 350℃, the spraying gas is nitrogen, the gas pressure is 4MPa, the powder feeding rate of the pretreated Cu-W composite powder is 350g / min, the distance from the nozzle to the surface of the CuCrZr panel is 40mm, the coating thickness is 3mm, and the thickness of the semi-finished CuCrZr panel is 20mm.

[0060] Example 14: This example differs from Example 1 in that the surface remelting parameters are different. The vacuum is evacuated to a vacuum degree of 3 Pa, and then argon gas is introduced as a protective gas for surface remelting. The surface remelting parameters are set as follows: scanning interval of 0.1 mm, power of 450 W, and scanning speed of 1600 mm / s.

[0061] Example 15: This example differs from Example 1 in that the surface remelting parameters are different. The vacuum is evacuated to a vacuum degree of 5 Pa, and then argon gas is introduced as a protective gas for surface remelting. The surface remelting parameters are set as follows: scanning interval of 0.05 mm, power of 500 W, and scanning speed of 1000 mm / s.

[0062] Example 16: This example differs from Example 1 in that the surface of the semi-finished CuCrZr panel is processed after the heat preservation is completed as follows: After the heat preservation is completed and the surface is naturally cooled to 225°C, a treatment agent with a temperature of 75°C is sprayed onto the surface of the semi-finished CuCrZr panel, and mechanical polishing is performed simultaneously until the surface temperature of the semi-finished CuCrZr panel drops to 105°C. Then, a treatment agent with a temperature of 45°C is sprayed onto the surface of the semi-finished CuCrZr panel, and mechanical polishing is performed simultaneously until the surface temperature of the semi-finished CuCrZr panel drops to 55°C. Spraying and polishing are stopped, and a cleaning agent is used for flowing cleaning. During the cleaning process, the cleaning agent is cooled at an initial temperature of 55°C at a rate of 5°C / min until the surface temperature of the semi-finished CuCrZr panel is 22°C, at which point the processing is complete.

[0063] The treatment agent is obtained by mixing nano-cerium oxide and phosphating polishing agent at a mass ratio of 1:15. The phosphating polishing agent is an acidic aqueous solution of Mn(H2PO4)2 with a pH value of 2. The cleaning agent is commercially available CNW RBS high-performance alkaline cleaning agent.

[0064] Example 17: This example differs from Example 16 in that the surface processing parameters are different. After the heat preservation is completed and the surface cools naturally to 220°C, a treatment agent with a temperature of 80°C is sprayed onto the surface of the semi-finished CuCrZr panel, and mechanical polishing is performed simultaneously. When the surface temperature of the semi-finished CuCrZr panel drops to 100°C, a treatment agent with a temperature of 40°C is sprayed onto the surface of the semi-finished CuCrZr panel, and mechanical polishing is performed simultaneously. When the surface temperature of the semi-finished CuCrZr panel drops to 50°C, spraying and polishing are stopped, and a cleaning agent is used for flowing cleaning. During the cleaning process, the cleaning agent is initially at 50°C and then cooled at a rate of 4°C / min until the surface temperature of the semi-finished CuCrZr panel reaches 25°C, at which point the treatment is complete.

[0065] Example 18: This example differs from Example 16 in that the surface processing parameters are different. After the heat preservation is completed and the surface cools naturally to 230°C, a treatment agent with a temperature of 70°C is sprayed onto the surface of the semi-finished CuCrZr panel, and mechanical polishing is performed simultaneously. When the surface temperature of the semi-finished CuCrZr panel drops to 110°C, a treatment agent with a temperature of 50°C is sprayed onto the surface of the semi-finished CuCrZr panel, and mechanical polishing is performed simultaneously. When the surface temperature of the semi-finished CuCrZr panel drops to 60°C, spraying and polishing are stopped, and a cleaning agent is used for flowing cleaning. During the cleaning process, the cleaning agent is initially at 60°C and then cooled at a rate of 6°C / min until the surface temperature of the semi-finished CuCrZr panel reaches 20°C, at which point the treatment is complete.

[0066] Example 19: The difference between this example and Example 16 is that the composition of the treatment agent is different. The treatment agent is obtained by mixing nano-cerium oxide and phosphating polishing agent at a mass ratio of 1:20. The phosphating polishing agent is an acidic aqueous solution of Mn(H2PO4)2 with a pH value of 3.

[0067] Example 20: The difference between this example and Example 16 is that the composition of the treatment agent is different. The treatment agent is obtained by mixing nano-cerium oxide and phosphating polishing agent in a mass ratio of 1:10. The phosphating polishing agent is an acidic aqueous solution of Mn(H2PO4)2 with a pH value of 1.

[0068] Experimental Example: The description of this experimental example is based on the scheme described in Example 1, and aims to illustrate the practical application effect of the present invention.

[0069] Experimental Example: 1. Test the engine injector panels obtained in Examples 1 to 20 respectively.

[0070] The thermal fatigue test consisted of heating to 750℃ (upper limit temperature), holding at that temperature for 5 minutes, then removing the sample and immersing it in water to cool for 0.5 minutes at room temperature (lower limit temperature). This process was repeated 200 times. Every 40 cycles, the sample was removed, polished to remove the surface oxide film, and its Vickers hardness was measured. The hardness test load was 0.49 N, and the holding time was 10 seconds.

[0071] The test was repeated 200 times. The results are as follows:

[0072] 1. Investigate the effects of different treatment methods on the performance of the obtained engine injector panel;

[0073] Comparative Example 1: The difference from Example 1 is that no cold spraying was performed, and the semi-finished CuCrZr alloy panel was directly used as the sprayer panel.

[0074] Comparative Example 2: Unlike Example 1, cold spraying was not performed; the surface of the semi-finished CuCrZr panel was directly laser-remelted.

[0075] Comparative Example 3: The difference from Example 1 is that in step S6, the Cu-W coating is directly heated until it melts, without laser remelting;

[0076] Comparative Example 4: Unlike Example 1, no drying process was performed;

[0077] Comparative Example 5: Unlike Example 1, no ultrasonic treatment was performed.

[0078] Surface panel samples from Examples 1, 16, and Comparative Examples 1-3 were taken for comparison, and the experimental results are shown in Table 1.

[0079] Table 1. Experimental results showing the influence of different treatment methods on the performance of the obtained engine injector panel.

[0080]

[0081] As can be seen from Table 1, Example 1 has superior performance in all aspects;

[0082] Comparing Example 1 with Comparative Example 1, it can be seen that the semi-finished CuCrZr panel obtained by laser printing in Example 1 can better integrate with the Cu-W composite coating. Cu has a low melting point and will melt at high temperature to remove heat from the surface of CuCrZr. The two can play the "sweating" role of the porous matrix and the low melting point alloy in the sweating cooling material, thereby improving the heat resistance of the finished panel material. The performance after thermal fatigue treatment shows that the heat resistance of Example 1 is better.

[0083] Comparing Example 1 and Comparative Example 2, it can be seen that Comparative Example 2 did not undergo a cold spraying step. Since cold spraying has advantages such as low oxide content, low thermal stress, high hardness, good bonding strength, and the ability to transfer the microstructure of the sprayed material to the substrate surface without changing it, the hardness and other properties in Example 1 are superior to those in Comparative Example 2.

[0084] Comparing Example 1 and Comparative Example 3, it can be seen that the direct heating remelting in Comparative Example 3 is not superior to the laser treatment remelting in Example 1. The laser treatment remelting in Example 1 utilizes laser heating to rapidly melt the metal surface, followed by rapid solidification through the metal's own heat transfer. Laser remelting can create a finer non-equilibrium structure on the material surface, improving hardness and heat resistance. Therefore, Example 1 is more preferred.

[0085] Comparing Example 1 and Example 16, it can be found that in Example 16, the semi-finished CuCrZr panel underwent surface processing. Surface processing can enhance the adhesion between the coating and the semi-finished CuCrZr panel, thereby optimizing the effects of cold spraying and remelting, and making the finished panel perform better in heat fatigue resistance.

[0086] Comparing Example 1 and Comparative Example 4, it can be seen that the performance of Example 1 is slightly better than that of Comparative Example 4. This is because drying can reduce the moisture content of the raw material powder, preventing problems such as flowing, sticking, and collapsing during the molding process, thereby improving the molding quality. Drying can also make the raw material powder more compact, reducing friction and resistance during the molding process, thus increasing the molding speed. The moisture in the raw material powder will evaporate during the molding process, which may lead to surface defects, porosity, and shrinkage, resulting in a decrease in hardness performance after simulated brazing treatment. Drying can reduce the occurrence of these defects.

[0087] Comparing Example 1 and Comparative Example 5, it can be seen that the performance of Example 1 is slightly better than that of Comparative Example 5. This is because ultrasonic vibration can make the molding quality more uniform and stable, thereby improving the molding quality and reliability.

[0088] 2. Investigate the effects of different parameters on panel performance;

[0089] Examples 1 and 4-7 were compared, as shown in Table 2.

[0090] Table 2. Experimental results showing the influence of different preparation parameters on the performance of the obtained engine injector panel.

[0091]

[0092] As can be seen from Table 2, comparing Examples 1, 2, and 3, the raw material composition in Example 1 is more preferred; comparing Examples 1, 4, and 5, the drying and ultrasonic treatment parameters in Example 1 are more preferred; comparing Examples 1, 6, and 7, it is shown that the selection of laser printing parameters has an impact on the performance of the finished panel. By scanning using the powder spreading method of this scheme, the surface powder will be recycled after the parts are processed. The parts obtained by the above layer-by-layer printing method have better quality, and the laser printing parameters in Example 1 are more preferred; comparing Examples 1, 12, and 13, it can be seen that the cold spraying parameters in Example 1 are more preferred. The parameter settings in Example 1 can better bring out the advantages of cold spraying, such as low thermal stress, high hardness, and good bonding strength; comparing Examples 1, 14, and 15, it can be seen that the surface remelting parameters in Example 1 are more preferred. The laser heating in Example 1 can better form a finer non-equilibrium structure on the material surface, thereby improving the hardness, wear resistance, and other properties; comparing Example 16 in Table 1 with the key Examples 19 and 20 in Table 2, it can be seen that the surface processing parameters in Example 16 are more preferred.

Claims

1. A method for preparing a liquid rocket engine injector panel, characterized in that, Includes the following steps: S1. Preparation of alloy powder: CuCrZr alloy atomized powder and Cu-W composite powder were dried, cooled and ultrasonically vibrated respectively, and then sieved to obtain pretreated CuCrZr alloy powder and pretreated Cu-W composite powder. S2, Laser Printing: Import the drawn 3D model into the laser selective melting equipment, fill the pretreated CuCrZr alloy powder, place the base plate, install the scraper, and then evacuate the laser selective melting equipment to a vacuum degree of 3~5Pa. Then, argon gas is introduced as a protective gas. The powder is evenly spread to the laser processing area by the scraper and printed to obtain a semi-finished CuCrZr panel. S3, Heat Treatment: The semi-finished CuCrZr panel obtained in step S2 is subjected to vacuum heat treatment. The vacuum heat treatment temperature is 420~500℃, the heating rate is 9~11℃ / min, and the holding time is 2~5h. S4. Surface Finishing: After the heat preservation is completed, the surface of the semi-finished CuCrZr panel is processed until the surface roughness Ra≤1.6μm; S5, Cold Spray Coating: The pretreated Cu-W composite powder is loaded into the powder feeder and sprayed onto the semi-finished CuCrZr panel to obtain a panel with a Cu-W coating. S6, Surface remelting: The panel with Cu-W coating obtained in step S5 is placed in a laser selective melting device for surface remelting to obtain the finished panel.

2. The method for preparing a liquid rocket engine injector panel as described in claim 1, characterized in that, In step S1, the drying treatment is performed in a vacuum drying oven, the drying treatment temperature is 100-180℃, the drying treatment time is 4-10h, and the vacuum degree in the vacuum drying oven is 10 -4 ~10 -3 Pa.

3. The method for preparing a liquid rocket engine injector panel as described in claim 1, characterized in that, In step S1, the ultrasonic vibration treatment time is 5~10 min, the ultrasonic vibration frequency is 35~40 kHz, and the ultrasonic vibration deviation angle is 8~10°.

4. The method for preparing a liquid rocket engine injector panel as described in claim 1, characterized in that, In step S2, the printing parameters of the semi-finished CuCrZr panel are set as follows: the thickness of a single layer of pre-treated CuCrZr alloy powder is 0.03~0.06mm, the scanning spacing is 0.05~0.1mm, the power is 380~460W, and the scanning speed is 400~1600mm / s.

5. The method for preparing a liquid rocket engine injector panel as described in claim 1, characterized in that, In step S2, the printing includes: after each laser scan is completed, the base plate descends one layer until printing is completed, and the angle between the N+1th layer and the Nth layer scan line is 45°~90°.

6. The method for preparing a liquid rocket engine injector panel as described in claim 1, characterized in that, In step S5, the cold spraying parameters are set as follows: spraying temperature is 350~600℃, spraying gas is nitrogen, gas pressure is 4~8MPa, powder feeding rate of pretreated Cu-W composite powder is 150~350g / min, distance from nozzle to surface of semi-finished CuCrZr panel is 20~40mm, and ratio of coating thickness to thickness of semi-finished CuCrZr panel is 3~5:10~20.

7. The method for preparing a liquid rocket engine injector panel as described in claim 1, characterized in that, In step S6, the specific operation of surface remelting is as follows: the panel with Cu-W coating is placed on the base plate of the laser selective melting equipment with the Cu-W coating side facing upwards. Then, the laser selective melting equipment is evacuated to a vacuum degree of 3~5 Pa. Argon gas is then introduced as a protective gas, and surface remelting is performed. The parameters for surface remelting are set as follows: scanning interval of 0.05~0.1 mm, power of 450~500 W, and scanning speed of 1000~1600 mm / s.

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