A feasible forming method of a composite sandwich nozzle

Abstract

The application discloses a kind of feasibility forming methods of composite sandwich nozzle, belong to the technical field of aeronautical rocket nozzle, including S1, alloy powder preparation: CuCrZr alloy atomized powder and nickel powder are dried and ultrasonic vibration treatment standby;S2, cold spraying: setting parameter, and the blank of nozzle lining is prepared by cold spraying;S3, machining: the semi-finished nozzle lining with surface channel is obtained by machining;S4, surface treatment: CuCrZr layer and nickel layer are sprayed in turn on the outer surface of nozzle lining by cold spraying;S5, diffusion welding: diffusion welding is carried out by hot isostatic pressing furnace, and stainless steel outer wall is prepared;S6, post-processing: machining to target size;The feasibility forming method of composite sandwich nozzle provided by the application is novel in technology, greatly shortens test procedure and cycle, improves material utilization rate while ensuring stable operation of rocket nozzle.

Description

Technical Field

[0001] This invention relates to the field of aero-rocket nozzle technology, specifically to a feasible molding method for a composite sandwich nozzle. Background Technology

[0002] The nozzle is a crucial component of a rocket engine. It works by altering the geometry of the inner wall of the nozzle section to expand and accelerate the combustion products of the propellant, thereby providing propulsion. Combustion causes the gas to expand, which in turn increases its temperature. Within the main combustion chamber, the gas temperature can reach as high as 3500K. Currently, the mainstream cooling method for rocket engines is the sandwich regenerative cooling nozzle.

[0003] Currently, there are two main methods for forming regenerable cooling nozzles. One is the traditional "casting-forging-machining-diffusion welding" process. This process has a long production cycle and low material utilization, mainly because the forging and diffusion welding processes are time-consuming, and the entire forming process involves many steps, requiring more than three months to complete. Furthermore, this method results in a large machining allowance after forging, necessitating machining removal, and a material utilization rate of less than 10%. The second method involves "3D printing" technologies such as electron beam printing and laser printing. While this technology can fabricate complex structural parts, its drawbacks are also significant: slow printing speed (only 3-5 g / min) and immature technology, requiring densification through hot isostatic pressing. Therefore, we urgently need a forming method that offers fast production speed, good cooling effect, high material utilization, and good process repeatability to prepare regenerable cooling rocket nozzle components. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a feasible molding method for a composite sandwich nozzle.

[0005] The technical solution of this invention is: a feasible molding method for a composite sandwich nozzle, comprising the following steps:

[0006] S1. Alloy powder preparation: CuCrZr alloy atomized powder and nickel powder are dried separately in a vacuum drying oven. After drying, they are cooled with the furnace and then subjected to ultrasonic vibration treatment. Finally, they are sieved through a 270-mesh sieve and the sieve-underfill material is taken to obtain pretreated CuCrZr alloy powder and pretreated nickel powder.

[0007] S2. Cold spraying: The pretreated CuCrZr alloy powder and pretreated nickel powder are loaded into the powder feeder and sprayed on the aluminum substrate according to the set parameters to obtain the blank of the nozzle liner.

[0008] S3. Machining: Grooves are machined on the surface of the nozzle liner blank obtained in step S2 to obtain a semi-finished nozzle liner;

[0009] S4. Surface treatment: The channels on the semi-finished nozzle liner obtained in step S3 are sealed with soluble filler, and CuCrZr alloy atomized powder and nickel powder are sprayed onto the outer surface of the semi-finished nozzle liner by cold spraying, so as to generate CuCrZr interlayer and nickel interlayer in sequence, and obtain the surface-treated nozzle liner. The aluminum matrix inside the nozzle liner is then removed by machining.

[0010] S5. Diffusion Welding: Assemble the two pre-prepared stainless steel outer walls with the nozzle inner liner 1 obtained in step S4 after surface treatment, and weld the manifold to the upper and lower ends of the nozzle and the stainless steel outer walls using manual argon arc welding. Evacuate to 1×10 through the vacuum tube on the manifold. -3 ~1×10 -2 Pa, then welded and sealed, and hot isostatic diffusion welding of the inner and outer wall components of the nozzle is performed by hot isostatic pressing. After the hot isostatic diffusion welding is completed, a nozzle assembly with a sleeve is obtained.

[0011] S6. Post-processing: Remove excess material through machining to obtain the finished nozzle with a stainless steel outer wall.

[0012] Furthermore, in step S1, the drying time for CuCrZr alloy atomized powder and nickel powder is 4-10 hours, and the vacuum degree in the vacuum drying oven is 1×10⁻⁶. -4 ~1×10 -3 Pa, the temperature inside the vacuum drying oven is 100-180℃;

[0013] 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.

[0014] 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°.

[0015] Note: Ultrasonic vibration can make the molding quality more uniform and stable, thereby improving the molding quality and reliability.

[0016] Further, in step S2, the printing parameters of the inner wall of the cold spray nozzle are set as follows: the spraying temperature is 350-600℃, the spraying gas is nitrogen, the gas pressure is 3-7MPa, the powder feeding rate of pretreated CuCrZr powder and pure nickel powder is 150-350g / min, and the distance from the nozzle to the substrate surface is 20-40mm.

[0017] 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.

[0018] Further, in step S4, the surface treatment method is as follows: the channel is sealed with a soluble filler to ensure that the height of the soluble filler is equal to the height of the rib, and CuCrZr powder is cold-sprayed to 3-8mm to form a CuCrZr interlayer. Then, a nickel layer with a thickness of 3-5mm is sprayed using an air blower to form a nickel interlayer. Subsequently, the channel is heated until the soluble filler is completely melted and flows out. The channel is then washed with deionized water 3-5 times to remove the soluble filler in the channel.

[0019] Note: The above setup achieves higher spraying efficiency by sealing the channel before cold spraying. The nickel in the cold spray mainly helps the welding process to proceed faster, effectively improving the welding effect.

[0020] Furthermore, the soluble filler is a pure metal or alloy that can be chemically dissolved;

[0021] Note: Using pure metals or alloys as fillers can further avoid introducing new impurities, thereby reducing interference with the welding effect.

[0022] Furthermore, in step S5, before performing hot isostatic diffusion welding on the inner and outer wall components of the nozzle using a hot isostatic press, a first pulsed plasma explosion treatment is performed on the inner wall of the nozzle, followed by a second pulsed plasma explosion treatment on the outer wall of the nozzle. After the treatment is completed, the nozzle is subjected to ultrasonic water bath treatment at a temperature of 20-25°C for 20-25 minutes and then thoroughly dried. Finally, the inner and outer wall components of the nozzle are subjected to hot isostatic diffusion welding using a hot isostatic press.

[0023] The pulse energy of the first pulsed plasma explosion treatment is 35-45J, the impact frequency is 8-15 times / second, and the plasma temperature is 230-270℃; the pulse energy of the second pulsed plasma explosion treatment is 20-30J, the impact frequency is 8-15 times / second, and the plasma temperature is 200-230℃.

[0024] The temperature of the hot isostatic diffusion welding is 900-1000℃, the pressure of the diffusion welding is 100-150MPa, and the duration of the diffusion welding is 2-8h. During the process, an antioxidant is sprayed onto the inner and outer walls of the nozzle every 25-30 minutes, and the total coating thickness of the antioxidant is 1-1.5mm.

[0025] Note: Hot isostatic pressure diffusion welding is performed under high temperature and uniform pressure, which makes the metal material in the weld area have the same strength as the base material and excellent toughness. Hot isostatic pressure diffusion welding can precisely control the shape and size of the weld joint, thereby reducing the deformation and defects of the weld joint and improving the quality and reliability of the weld joint.

[0026] Pulsed plasma explosion treatment effectively removes dirt and oxides from the nozzle surface, while ultrasonic cleaning further cleans hard-to-reach areas such as tiny gaps and grooves on the nozzle surface. This two-step cleaning process significantly improves the cleanliness of the nozzle surface, creating favorable surface conditions for subsequent hot isostatic diffusion welding. Simultaneously, pulsed plasma explosion treatment and ultrasonic cleaning effectively enhance surface activity, improving the wettability and adhesion between the nozzle and the copper-chromium-zirconium and nickel layers, thus improving the quality of the weld joint and enhancing its strength, density, and durability. Furthermore, the addition of antioxidants reduces the need for subsequent heat treatment of the finished nozzle, improving manufacturing efficiency.

[0027] Further, the antioxidant comprises, by weight percentage: 85-90% sodium acetate, 0.3-0.5% borate ester, 0.05-0.1% sodium dihydrogen phosphate citrate, and the balance being ceramic particles;

[0028] Explanation: The antioxidants in the above-mentioned components can slow down the oxidation rate of copper-chromium-zirconium and nickel layers at high temperatures, reduce the resistance to element diffusion, and promote the interpenetration and diffusion of joint elements, thereby improving the strength and density of the welded joint. Sodium acetate can also reduce the resistance to element diffusion during metal welding and promote the interpenetration and diffusion of joint elements. Sodium citrate phosphate can further reduce the surface tension of the material and improve its corrosion resistance and oxidation resistance. Ceramic particles can increase the density of the weld zone, reduce the formation of pores and inclusions, and further improve the quality of diffusion welding. The antioxidants prepared by the above components have the effect of eliminating internal stress and improving the surface quality of the workpiece. Intermetallic compounds such as Ni3Al and Ni3Zr, which have good thermal stability and oxidation resistance, may be formed between CuCrZr alloy powder and nickel powder, which can reduce the resistance to element diffusion and further promote the interpenetration and diffusion of joint elements.

[0029] Furthermore, in step S6, the finished nozzle consists of a grooved cold-sprayed inner wall, a CuCrZr layer, a nickel layer, and a stainless steel outer wall 2, from the nozzle inner liner 1 to the stainless steel outer wall 2.

[0030] Note: The new design of the composite sandwich nozzle can improve cooling effect and connection reliability.

[0031] The beneficial effects of this invention are:

[0032] (1) The "cold spraying composite sandwich nozzle" method used in the forming method of the composite sandwich nozzle of the present invention is innovative in that it has a fast preparation speed, the powder feeding rate can reach 300g / min, the material utilization rate is high, the deposition rate can reach more than 95%, and the process repeatability is good. In addition, cold spraying can easily optimize the nozzle structure. Through the beneficial combination of cold spraying technology and diffusion welding, the production cycle can be significantly shortened while improving the cooling effect.

[0033] (2) Compared with conventional hot isostatic diffusion welding, the diffusion welding method of the present invention can effectively enhance surface activity, thereby facilitating the wetting and bonding between the nozzle and the copper-chromium-zirconium layer and nickel layer, improving the quality of the weld joint, and further enhancing the strength, density and durability of the weld joint; at the same time, the addition of antioxidants can avoid the oxidation of materials from affecting the welding quality and eliminate the need for subsequent heat treatment of the nozzle finished product, thereby improving the preparation efficiency. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of the finished composite sandwich nozzle of the present invention;

[0035] Figure 2 This is an assembly drawing of the hot isostatic diffusion welding process of the present invention;

[0036] Figure 3 This is a partial cross-sectional view of the composite sandwich nozzle of the present invention;

[0037] Among them, 1-nozzle liner, 2-stainless steel outer wall, 11-channel, 12-CuCrZr interlayer, 13-nickel interlayer. Detailed Implementation

[0038] The present invention will now be described in more detail with reference to specific embodiments, so as to better demonstrate the advantages of the present invention.

[0039] Example 1: A feasible molding method for a composite sandwich nozzle, comprising the following steps:

[0040] S1. Alloy powder preparation: CuCrZr alloy atomized powder and nickel powder are dried separately in a vacuum drying oven. After drying, they are cooled with the furnace and then subjected to ultrasonic vibration treatment. Finally, they are sieved through a 270-mesh sieve and the sieve-underfill material is taken to obtain pretreated CuCrZr alloy powder and pretreated nickel powder.

[0041] In step S1, the drying time for CuCrZr alloy atomized powder and nickel powder is 7 hours, and the vacuum degree in the vacuum drying oven is 1×10⁻⁶. -3.5 Pa, the temperature inside the vacuum drying oven is 140℃; the ultrasonic vibration treatment time is 7min, the ultrasonic vibration frequency is 38kHz, and the ultrasonic vibration deviation angle is 9°.

[0042] S2. Cold spraying: The pretreated CuCrZr alloy powder and pretreated nickel powder are loaded into the powder feeder and sprayed on the aluminum substrate according to the set parameters to obtain the blank of the nozzle liner 1.

[0043] In step S2, the printing parameters for the inner wall of the cold spray nozzle are set as follows: the spraying temperature is 475℃, the spraying gas is nitrogen, the gas pressure is 5MPa, the powder feeding rate of pretreated CuCrZr powder and pure nickel powder is 250g / min, and the distance from the nozzle to the substrate surface is 30mm.

[0044] S3. Machining: Grooves 11 are machined on the surface of the blank of the nozzle liner 1 obtained in step S2 to obtain a semi-finished nozzle liner.

[0045] S4. Surface treatment: The grooves 11 on the semi-finished nozzle liner obtained in step S3 are sealed with soluble filler, and CuCrZr alloy atomized powder and nickel powder are sprayed onto the outer surface of the semi-finished nozzle liner by cold spraying, so as to generate CuCrZr interlayer 12 and nickel interlayer 13 in sequence, and the surface-treated nozzle liner 1 is obtained. The aluminum matrix inside the nozzle liner 1 is then removed by machining.

[0046] In step S4, the surface treatment method is as follows: the channel 11 is sealed with soluble filler to ensure that the height of the soluble filler is equal to the height of the rib, and CuCrZr powder is cold sprayed to 5mm to form CuCrZr interlayer. Then, a nickel layer with a thickness of 4mm is sprayed using an air blower to form nickel interlayer 13. Subsequently, the channel 11 is heated until the soluble filler is completely melted and flows out. The channel 11 is then washed 4 times with deionized water to remove the soluble filler in the channel 11.

[0047] The soluble filler is a soluble magnesium alloy, of which magnesium powder accounts for 85%, aluminum powder 10%, and zinc powder 5%.

[0048] S5. Diffusion Welding: Assemble the two pre-prepared stainless steel outer walls 2 with the nozzle inner liner 1 obtained in step S4, and weld the manifold to the upper and lower ends of the nozzle and the stainless steel outer walls 2 using manual argon arc welding. Evacuate to 1×10 through the vacuum tube on the manifold. -2.5 Pa, then welded and sealed, and hot isostatic diffusion welding of the inner and outer wall components of the nozzle is performed by hot isostatic pressing. After the hot isostatic diffusion welding is completed, a nozzle assembly with a sleeve is obtained.

[0049] In step S5, before performing hot isostatic diffusion welding on the inner and outer wall components of the nozzle using a hot isostatic press, the inner wall of the nozzle is subjected to a first pulse plasma explosion treatment, and then the outer wall of the nozzle is subjected to a second pulse plasma explosion treatment. After the treatment is completed, the nozzle is subjected to ultrasonic water bath treatment at 23°C for 23 minutes and then fully dried. Then, the inner and outer wall components of the nozzle are subjected to hot isostatic diffusion welding using a hot isostatic press.

[0050] The pulse energy of the first pulsed plasma explosion treatment was 40J, the impact frequency was 12 times / second, and the plasma temperature was 2500℃; the pulse energy of the second pulsed plasma explosion treatment was 25J, the impact frequency was 12 times / second, and the plasma temperature was 2150℃.

[0051] The temperature of hot isostatic diffusion welding is 950℃, the pressure of diffusion welding is 125MPa, the duration of diffusion welding is 5h, and an antioxidant is sprayed onto the inner and outer walls of the nozzle every 28 minutes during the process, with a total coating thickness of 1.2mm.

[0052] The antioxidants, by weight percentage, comprise: 87% sodium acetate, 0.4% borate ester, 0.07% sodium dihydrogen phosphate citrate, and the balance being nano-alumina;

[0053] S6. Post-processing: Remove excess material through machining to obtain the finished nozzle with a stainless steel outer wall.

[0054] Example 2: Unlike Example 1, in step S1, the drying time for CuCrZr alloy atomized powder and nickel powder is 4 hours, and the vacuum degree in the vacuum drying oven is 1×10⁻⁶. -4 Pa, the temperature inside the vacuum drying oven is 100℃.

[0055] Example 3: Unlike Example 1, in step S1, the drying time for CuCrZr alloy atomized powder and nickel powder is 10 hours, and the vacuum degree in the vacuum drying oven is 1×10⁻⁶. -3 Pa, the temperature inside the vacuum drying oven is 180℃.

[0056] Example 4: Unlike Example 1, in step S1, the ultrasonic vibration treatment time is 5 min, the ultrasonic vibration frequency is 40 kHz, and the ultrasonic vibration deviation angle is 8°.

[0057] Example 5: Unlike Example 1, in step S1, the ultrasonic vibration treatment time is 10 min, the ultrasonic vibration frequency is 35 kHz, and the ultrasonic vibration deviation angle is 10°.

[0058] Example 6: Unlike Example 1, in step S2, the printing parameters of the inner wall of the cold spray nozzle are set as follows: spraying temperature is 350℃, spraying gas is nitrogen, gas pressure is 3MPa, powder feeding rate of pretreated CuCrZr powder and pure nickel powder is 150g / min, and distance from nozzle to substrate surface is 20mm.

[0059] Example 7: Unlike Example 1, in step S2, the printing parameters of the inner wall of the cold spray nozzle are set as follows: spraying temperature is 600℃, spraying gas is nitrogen, gas pressure is 7MPa, powder feeding rate of pretreated CuCrZr powder and pure nickel powder is 350g / min, and distance from nozzle to substrate surface is 40mm.

[0060] Example 8: Unlike Example 1, in step S4, the surface treatment method is as follows: the channel 11 is sealed with a soluble filler to ensure that the height of the soluble filler is equal to the height of the rib, and CuCrZr powder is cold-sprayed to 3mm to form a CuCrZr interlayer 12. Then, a nickel layer with a thickness of 3mm is sprayed using an air blower to form a nickel interlayer 13. Subsequently, the channel 11 is heated until the soluble filler is completely melted and flows out. The channel 11 is then washed three times with deionized water to remove the soluble filler from the channel 11.

[0061] Example 9: Unlike Example 1, in step S4, the surface treatment method is as follows: the channel 11 is sealed with a soluble filler to ensure that the height of the soluble filler is equal to the height of the rib, and CuCrZr powder is cold-sprayed to 8mm to form a CuCrZr interlayer 12. Then, a nickel layer with a thickness of 5mm is sprayed using an air blower to form a nickel interlayer 13. Subsequently, the channel 11 is heated until the soluble filler is completely melted and flows out. The channel 11 is then washed 5 times with deionized water to remove the soluble filler in the channel 11.

[0062] Example 10: Unlike Example 1, the soluble filler is a soluble Al alloy, in which aluminum powder accounts for 85%, magnesium powder accounts for 10%, and zinc powder accounts for 5%.

[0063] Example 11: Unlike Example 1, before performing hot isostatic diffusion welding on the inner and outer wall components of the nozzle using a hot isostatic press, a first pulsed plasma explosion treatment is performed on the inner wall of the nozzle, followed by a second pulsed plasma explosion treatment on the outer wall of the nozzle. After the treatment is completed, the nozzle is subjected to ultrasonic water bath treatment at 20°C for 20 minutes and then thoroughly dried. Finally, the inner and outer wall components of the nozzle are subjected to hot isostatic diffusion welding using a hot isostatic press.

[0064] The pulse energy of the first pulsed plasma explosion treatment was 35J, the impact frequency was 8 times / second, and the plasma temperature was 230℃; the pulse energy of the second pulsed plasma explosion treatment was 20J, the impact frequency was 8 times / second, and the plasma temperature was 200℃.

[0065] The temperature of hot isostatic diffusion welding is 900℃, the pressure of diffusion welding is 100MPa, and the duration of diffusion welding is 2h. During the process, an antioxidant is sprayed onto the inner and outer walls of the nozzle every 25 minutes, and the total coating thickness of the antioxidant is 1mm.

[0066] Example 12: Unlike Example 1, before performing hot isostatic diffusion welding on the inner and outer wall components of the nozzle using a hot isostatic press, a first pulsed plasma explosion treatment is performed on the inner wall of the nozzle, followed by a second pulsed plasma explosion treatment on the outer wall of the nozzle. After the treatment is completed, the nozzle is subjected to ultrasonic water bath treatment at 25°C for 25 minutes and then thoroughly dried. Finally, the inner and outer wall components of the nozzle are subjected to hot isostatic diffusion welding using a hot isostatic press.

[0067] The pulse energy of the first pulsed plasma explosion treatment was 45J, the impact frequency was 15 times / second, and the plasma temperature was 270℃; the pulse energy of the second pulsed plasma explosion treatment was 30J, the impact frequency was 15 times / second, and the plasma temperature was 230℃.

[0068] The temperature of hot isostatic diffusion welding is 1000℃, the pressure of diffusion welding is 150MPa, and the duration of diffusion welding is 8h. During the process, an antioxidant is sprayed onto the inner and outer walls of the nozzle every 30 minutes, and the total coating thickness of the antioxidant is 1.5mm.

[0069] Example 13: Unlike Example 1, the antioxidant, by mass percentage, comprises: 85% sodium acetate, 0.3% borate ester, 0.05% sodium dihydrogen phosphate citrate, and the balance being ceramic particles.

[0070] Example 14: Unlike Example 1, the antioxidant, by mass percentage, comprises: 90% sodium acetate, 0.5% borate ester, 0.1% sodium dihydrogen phosphate citrate, and the balance being ceramic particles.

[0071] Experimental Example: For the composite sandwich nozzles of each embodiment, five samples from each embodiment were taken to test the ultimate tensile strength and relative density of the composite sandwich nozzle liner at room temperature. The average value of the test results of the five samples for each embodiment was taken as the test result for that embodiment. The specific investigation is as follows:

[0072] 1. Investigate the influence of various process parameters on the mechanical properties of the composite sandwich nozzle liner.

[0073] Table 1 Mechanical properties of composite sandwich nozzle liners prepared in Examples 1-14

[0074]

[0075]

[0076] Comparative Example 1: Unlike Example 1, the soluble filler is a soluble Ni alloy, in which nickel powder accounts for 85%, aluminum powder accounts for 10%, and zinc powder accounts for 5%.

[0077] Comparative Example 2: Unlike Example 1, hot isostatic pressing diffusion welding was performed directly using a hot isostatic press.

[0078] Comparative Example 3: Unlike Example 1, no antioxidant was sprayed on the inner and outer walls of the nozzle.

[0079] Comparative Example 4: Unlike Example 1, the antioxidant, by mass percentage, comprises 87% sodium acetate, 0.4% borate ester, and the balance ceramic particles.

[0080] Conclusion: Comparison of data from Examples 1-5 shows that the drying parameters and ultrasonic vibration parameters of CuCrZr alloy atomized powder and nickel powder affect the performance of the composite sandwich nozzle liner. Excessive or insufficient drying parameters and ultrasonic vibration parameters are detrimental to the tight distribution of the raw material powder, leading to defects on the surfaces of the CuCrZr and nickel layers, further reducing the performance of the composite sandwich nozzle liner. Comparison of data from Examples 1 and 6-9 shows that cold spraying printing parameters and surface treatment parameters have a relatively small impact on the performance of the composite sandwich nozzle. However, comparison of data from Examples 1, 10, and Comparative Example 1 shows that while using Ni alloy as the soluble filler can avoid introducing new impurities, the slightly higher melting temperature of Ni alloy makes it difficult to remove the soluble filler from the channels, resulting in reduced performance of the composite sandwich nozzle.

[0081] A comparison of the data from Examples 1, 12-13, and Comparative Example 2 reveals that the thermal isostatic diffusion effect in Comparative Example 2 was significantly affected by the absence of pulsed plasma explosion and ultrasonic water bath treatment. This is because the pretreatment not only improves the cleanliness of the nozzle surface but also effectively enhances its surface activity, which is beneficial for improving the wettability and bonding force between the nozzle and the copper-chromium-zirconium and nickel layers, thereby significantly improving the tensile strength and density of the finished nozzle. A comparison of the data from Examples 1, 12-13, and Comparative Example 3 shows that the lack of antioxidant spraying reduces the effectiveness of the diffusion welding treatment. This is because antioxidants can slow down the oxidation rate of copper-chromium-zirconium and nickel layers at high temperatures, reduce the resistance to element diffusion, and promote the mutual penetration and diffusion of joint elements, thereby improving the strength and density of the welded joint. As can be seen from the data comparison of Examples 1, 14-15 and Comparative Example 4, the nozzle performance obtained in Comparative Example 4 is reduced. This is because sodium citrate phosphate can further reduce the surface tension of the material, effectively reduce the occurrence of residual stress inside the nozzle under high temperature conditions, and at the same time improve the corrosion resistance and oxidation resistance of the material. Therefore, considering all factors, Example 1 is selected as the optimal solution.

Claims

1. A feasible molding method for a composite sandwich nozzle, characterized in that, Includes the following steps: S1. Alloy powder preparation: CuCrZr alloy atomized powder and nickel powder are dried separately in a vacuum drying oven. After drying, they are cooled with the furnace and then subjected to ultrasonic vibration treatment. Finally, they are sieved through a 270-mesh sieve and the sieve-underfill material is taken to obtain pretreated CuCrZr alloy powder and pretreated nickel powder. S2, cold spraying: The above-mentioned pretreated CuCrZr alloy powder and pretreated nickel powder are loaded into the powder feeder and sprayed on the aluminum substrate according to the set parameters to obtain the blank of the nozzle liner (1). S3. Machining: Grooves (11) are machined on the surface of the blank of the nozzle liner (1) obtained in step S2 to obtain a semi-finished nozzle liner; S4. Surface treatment: The groove (11) on the semi-finished nozzle liner obtained in step S3 is sealed with a soluble filler, and CuCrZr alloy atomized powder and nickel powder are sprayed onto the outer surface of the semi-finished nozzle liner by cold spraying, so as to generate CuCrZr interlayer (12) and nickel interlayer (13) in sequence, and the surface-treated nozzle liner (1) is obtained. The aluminum matrix inside the nozzle liner (1) is removed by machining. S5. Diffusion Welding: Assemble the two pre-prepared stainless steel outer walls (2) with the nozzle liner (1) obtained in step S4, and weld the manifold to the upper and lower ends of the nozzle and the stainless steel outer walls (2) using manual argon arc welding. Evacuate to 1×10 through the vacuum tube on the manifold. -3 ~1×10 -2 Pa, then welded and sealed, and hot isostatic diffusion welding of the inner and outer wall components of the nozzle is performed by hot isostatic pressing. After the hot isostatic diffusion welding is completed, a nozzle assembly with a sleeve is obtained. S6. Post-processing: Remove excess material through machining to obtain the finished nozzle with a stainless steel outer wall.

2. The feasible molding method for a composite sandwich nozzle as described in claim 1, characterized in that, In step S1, the drying time for CuCrZr alloy atomized powder and nickel powder is 4-10 hours, and the vacuum degree in the vacuum drying oven is 1×10⁻⁶. -4 ~1×10 -3 Pa, the temperature inside the vacuum drying oven is 100-180℃.

3. The feasible molding method for a composite sandwich nozzle as described in claim 1, characterized in that, 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°.

4. The feasible molding method for a composite sandwich nozzle as described in claim 1, characterized in that, In step S2, the printing parameters for the inner wall of the cold spray nozzle are set as follows: spraying temperature is 350-600℃, spraying gas is nitrogen, gas pressure is 3-7MPa, powder feeding rate of pretreated CuCrZr powder and pure nickel powder is 150-350g / min, and distance from nozzle to substrate surface is 20-40mm.

5. A feasible molding method for a composite sandwich nozzle as described in claim 1, characterized in that, In step S4, the surface treatment method is as follows: the channel (11) is sealed with a soluble filler to ensure that the height of the soluble filler is equal to the height of the rib, and CuCrZr powder is cold sprayed to 3-8mm to generate a CuCrZr interlayer (12). Then, a nickel layer with a thickness of 3-5mm is sprayed using an air blower to generate a nickel interlayer (13). Subsequently, the channel (11) is heated until the soluble filler is completely melted and flows out. The channel (11) is washed with deionized water 3-5 times to remove the soluble filler in the channel (11).

6. The feasible molding method for a composite sandwich nozzle as described in claim 5, characterized in that, The soluble filler is a pure metal or alloy that can be chemically dissolved.

7. The feasible molding method for a composite sandwich nozzle as described in claim 1, characterized in that, In step S5, before performing hot isostatic diffusion welding on the inner and outer wall components of the nozzle using a hot isostatic press, the inner wall of the nozzle is subjected to a first pulse plasma explosion treatment, and then the outer wall of the nozzle is subjected to a second pulse plasma explosion treatment. After the treatment is completed, the nozzle is subjected to ultrasonic water bath treatment at a temperature of 20-25°C for 20-25 minutes and then fully dried. Finally, the inner and outer wall components of the nozzle are subjected to hot isostatic diffusion welding using a hot isostatic press. The pulse energy of the first pulsed plasma explosion treatment is 35-45J, the impact frequency is 8-15 times / second, and the plasma temperature is 2300-2700℃; the pulse energy of the second pulsed plasma explosion treatment is 20-30J, the impact frequency is 8-15 times / second, and the plasma temperature is 2000-2300℃. The temperature of the hot isostatic diffusion welding is 900-1000℃, the pressure of the diffusion welding is 100-150MPa, and the duration of the diffusion welding is 2-8h. During the process, an antioxidant is sprayed onto the inner and outer walls of the nozzle every 25-30 minutes, and the total coating thickness of the antioxidant is 1-1.5mm.

8. The feasible molding method for a composite sandwich nozzle as described in claim 7, characterized in that, The antioxidant comprises, by weight percentage: 85-90% sodium acetate, 0.3-0.5% borate ester, 0.05-0.1% sodium dihydrogen phosphate citrate, and the balance being ceramic particles.

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