Preparation method of cross-scale heat dissipation structure for spacecraft component

Abstract

The invention provides a preparation method of a cross-scale heat dissipation structure for a spacecraft component, and belongs to the technical field of additive manufacturing and spacecraft thermal control. A characteristic structural part with a millimeter-scale groove is printed by adopting an additive manufacturing technology, a corresponding space magnetic mask plate is printed by utilizing a non-metal additive manufacturing technology, and magnetic shape parts with different magnetic field intensities can be placed below the space magnetic mask plate; and preparing a coating with a micron-sized coarse structure on the characteristic structural member with the millimeter-sized groove. The coating with the micron-sized coarse structure increases the surface area of the characteristic structural part, and the distribution density of the micron-sized coarse structure can be further improved by introducing functional particles into the coating. By increasing the surface area, the radiation heat dissipation effect of spacecraft parts can be remarkably enhanced, and the reliability of spacecraft operation is improved. The cross-scale heat dissipation coating prepared by the method has potential application space in the field of heat dissipation of spacecrafts.

Description

Technical Field

[0001] This invention belongs to the fields of additive manufacturing and spacecraft thermal control technology, specifically relating to a method for preparing a multi-scale heat dissipation structure for spacecraft components. Background Technology

[0002] Current forced convection and natural convection cooling methods are unsuitable for spacecraft operating in the space environment; radiative cooling is the only heat dissipation method for spacecraft thermal management systems. If overheating occurs and is not addressed promptly and effectively, it can severely impact the spacecraft's lifespan. Thermal coatings can reduce the probability of overheating by altering the radiation characteristics of an object's surface. Therefore, the preparation of thermal coatings has significant application value. Currently reported thermal coating preparation technologies include atmospheric plasma spraying, micro-arc oxidation, and the sol-gel method. However, these methods are complex, require stringent equipment, and are costly.

[0003] Electrodeposition technology is widely used to prepare metal coatings due to its simplicity and low cost, producing coatings with low porosity and high quality. In particular, by adding functional particles to the metal electroplating solution to create a composite electroplating solution, functional multi-scale composite coatings can be prepared. However, pure electrodeposition also has certain drawbacks in preparing multi-scale heat dissipation coatings. Composite coatings prepared by electrodeposition have low surface roughness, and their heat dissipation performance is also relatively low, far from meeting the standards for heat dissipation coatings. Directly coating key structural components of spacecraft would result in the entire surface of these components being covered, including areas where coating is unnecessary, thus affecting the overall performance of the components. Summary of the Invention

[0004] This invention provides a method for fabricating a multi-scale heat dissipation structure for spacecraft components. It offers a manufacturing method for characteristic structural parts of spacecraft components with millimeter-level grooves. Non-metallic additive manufacturing technology is used to fabricate a space-grooved magnetic mask for the characteristic structural parts. Magnetic shapes with different magnetic field strengths can be placed below the space-grooved magnetic mask. Through the synergistic effect of the space-grooved magnetic mask and magnetic field-induced electrodeposition technology, micron-level rough structures are fabricated on the characteristic structural parts, increasing the heat dissipation surface area and significantly improving the cooling effect.

[0005] To achieve this goal, the following technical solution is adopted:

[0006] A method for fabricating a multi-scale heat dissipation structure for spacecraft components is characterized by employing additive manufacturing technology to print a feature structure with millimeter-level grooves, and performing precision machining within specific requirements for the millimeter-level groove feature structure; using non-metallic additive manufacturing technology to print a corresponding space magnetic mask, under which magnetic shaped parts with different magnetic field strengths can be placed; and preparing a coating with a micron-level rough structure on the feature structure with millimeter-level grooves.

[0007] Furthermore, the additive manufacturing technology is selected from selective laser sintering or selective laser melting; the millimeter-level groove shape of the feature structure is selected from rectangular, semi-circular or conical; the feature structure is selected from aluminum alloy, titanium alloy, nickel-based alloy and copper alloy; the groove feature structure needs to be precision machined to a surface roughness ≤1μm.

[0008] Furthermore, the non-metallic additive manufacturing technology is selected from photopolymerization molding technology or digital light processing technology; the solution is resin plus magnetic particles, the material of the magnetic particles is selected from neodymium iron boron or samarium cobalt, and the concentration of the magnetic particles is 5-20 g / L; the magnetic shaped part is 10-30 mm long, 1-3 mm wide, and 1-2 mm high, and the material of the magnetic shaped part is selected from neodymium iron boron or samarium cobalt.

[0009] A method for preparing a multi-scale heat dissipation coating, applicable to the aforementioned method for preparing a multi-scale heat dissipation structure for spacecraft components, characterized in that it includes:

[0010] Step S1, Surface treatment of workpiece: Clean the feature structure with millimeter-level grooves with deionized water and alcohol in sequence, and dry them for later use;

[0011] Step S2, Fabrication of spatial magnetic mask: Spatial magnetic mask corresponding to the feature structure is fabricated using non-metallic additive manufacturing technology;

[0012] Step S3: Prepare the Watt's nickel plating solution: First, heat the deionized water, then add boric acid, nickel sulfate hexahydrate, and nickel chloride hexahydrate to the heated deionized water. Stir the solution thoroughly, and add a specific concentration of ammonia during this process to ensure the pH of the plating solution remains stable within a certain range.

[0013] Step S4: Prepare the functional particle composite electroplating solution: Add the functional particles and ferromagnetic particles to the Watt nickel electroplating solution of step S2, and perform ultrasonic oscillation and mechanical stirring during the process, and then set it aside for later use.

[0014] Step S5: Install and fix the workpiece prepared in step S1 and the spatial magnetic mask prepared in step S2 on the worktable of the magnetic field induced electrodeposition manufacturing equipment.

[0015] Step S6, preparation of cross-scale heat dissipation coating: The functional particle composite electroplating solution obtained in step S4 is transferred to the electroplating tank of the magnetic field induced electrodeposition preparation equipment to prepare a cross-scale heat dissipation coating.

[0016] Step S7: Immersion, rinsing, and drying of the cross-scale heat dissipation coating: Immerse the cross-scale heat dissipation coating obtained in step S6 in deionized water, and then rinse it several times with deionized water to remove any residual electroplating solution from the surface of the cross-scale heat dissipation coating. Then place the resulting cross-scale heat dissipation coating in a ventilated area to air dry naturally.

[0017] Further, in step S3, the deionized water used to prepare the Watt's nickel plating solution is heated to 80-100℃; the amount of boric acid added is 10-60 g / L; the amount of nickel sulfate hexahydrate added is 220-280 g / L; and the amount of nickel chloride hexahydrate added is 10-60 g / L. Ammonia water with a mass fraction of 5-10% is added when preparing the Watt's nickel plating solution to maintain the pH of the plating solution at 3.6-4.5.

[0018] Furthermore, the functional particles used in step S4 are selected from silicon carbide, alumina, and iron oxide, and the addition range of functional particles is 3-9 g / L; the ferromagnetic particles are selected from nickel particles and iron particles, the particle size of the ferromagnetic particles is 10-50 μm, and the addition range of ferromagnetic particles in the Watt nickel plating solution is 2-8 g / L; the ultrasonic vibration frequency is 35-40 kHz, and the treatment time is 30-60 min; the mechanical stirring speed is 600-1200 r / min, and the treatment time is 30-60 min.

[0019] Furthermore, the specific parameters for preparing the multi-scale heat dissipation coating in step S6 are as follows: the temperature of the functional particle composite electroplating solution is maintained at 40-60℃, and the flow rate is controlled at 160-300L / h. ； The current density at the nozzle is set to 60-140 A / dm. 2 The deposition time is set to 25-45 min, the magnetic field strength in the cathode deposition area is controlled at 20-80 mT by the space magnetic mask, the nozzle scanning speed is adjusted to 3-5 mm / s, and the gap between the nozzle and the workpiece is set to 1-3 mm.

[0020] Furthermore, the multi-scale heat dissipation coating further improves the heat dissipation performance of the feature structure by increasing the heat dissipation surface area of ​​the groove; the multi-scale heat dissipation coating has a high average emissivity.

[0021] The advantages of this invention compared to the prior art are as follows:

[0022] This invention utilizes non-metallic additive manufacturing to construct corresponding spatial magnetic masks based on different structural features. By placing magnetic shapes with different magnetic field strengths below the spatial magnetic mask, the magnetic particles within the mask and the magnetic shapes together regulate the magnetic field distribution during coating preparation. The spatial magnetic mask has a short manufacturing time and high reliability.

[0023] This invention utilizes magnetic field-induced electrodeposition technology combined with a spatial magnetic mask to prepare a cross-scale heat dissipation coating with a micron-scale rough structure on a feature structure with millimeter-scale grooves. The cross-scale heat dissipation coating improves the overall heat dissipation performance of the feature structure by increasing the heat dissipation area on the surface of the feature structure.

[0024] This invention presents a novel electroplating solution system for preparing multi-scale heat dissipation coatings. Specifically, high-infrared-emissivity functional particles are added to a Watt's nickel electroplating solution. Utilizing the characteristic that ferromagnetic particles can act as carriers for these functional particles, the high-infrared-emissivity particles are introduced into the coating, increasing its surface area. This further improves the heat dissipation performance of the multi-scale heat dissipation coating, resulting in a high average emissivity. Attached Figure Description

[0025] Figure 1 Three-dimensional images of structural components with different features and corresponding spatial magnetic mask templates;

[0026] Figure 2 A 3D view showing the installation position of a magnetic shaped component in a space with a magnetic mask template;

[0027] Figure 3 This is a schematic diagram of the method for fabricating the multi-scale heat dissipation structure of the present invention;

[0028] Figure 4 This is a diagram illustrating the coating preparation process in Example 2;

[0029] Figure 5 These are scanning electron microscope images of Comparative Example 1 and Example 2;

[0030] Figure 6 The X-ray spectrum of Example 2;

[0031] Figure 7 The image shows a comparison of the infrared emissivity of the feature structure of Example 1 and Comparative Example 1 and Example 2.

[0032] The labels are as follows: 1-planar feature structure, 2-planar spatial magnetic mask, 3-curved surface feature structure, 4-curved spatial magnetic mask, 5-power supply, 6-nozzle, 7-working anode, 8-electroplating solution, 9-spatial magnetic mask, 10-feature structure cathode. Detailed Implementation

[0033] To more clearly illustrate the purpose, technical solution, and effects of this invention, specific examples are provided below for detailed description. It is important to note that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0034] Example 1:

[0035] The fabrication method of the feature structure with millimeter-level rectangular grooves and the corresponding spatial magnetic mask is as follows:

[0036] A feature structure with an array of rectangular grooves on its surface is constructed using laser selective melting forming technology. The feature structure is made of aluminum alloy and measures 30×30mm. The rectangular grooves are 30mm long, 3mm wide, and 2mm deep. Figure 1 As shown, the surface of the feature structure can be made into a plane 1 or a curved surface 3;

[0037] The surface is polished using electrical discharge machining (EDM) technology, resulting in a surface roughness of ≤1μm for the structural components. The pulse width of the EDM technology is 150μs, the pulse interval is 100μs, and the peak current is 30A.

[0038] Spatial magnetic photomasks were prepared using photopolymerization technology. A slurry containing resin and NdFeB particles was prepared and then cured in a photopolymerization apparatus to produce planar spatial magnetic photomasks 2 and curved spatial magnetic photomasks 4 to adapt to corresponding feature structures. The exposure intensity during the photopolymerization process was selected as 8000 μW / cm². 2 The exposure time was set to 6 seconds, the forming thickness to 91 μm, and the NdFeB particle concentration to 10 g / L. A magnetic shape element, 25 mm long, 2 mm wide, and 1 mm high, was added below the spatial magnetic mask. The specific installation position of the magnetic shape element is as follows... Figure 2 As shown.

[0039] Example 2:

[0040] Methods for preparing multi-scale heat dissipation coatings, such as Figure 4 As shown, the specific steps are as follows:

[0041] The feature structure prepared in Example 1 was selected as the cathode substrate material. The material was sequentially cleaned with acetone, alcohol, and deionized water. This process was carried out entirely under an ultrasonic environment of 40 kHz for 20 minutes. Then, a spatial mask was placed on the surface of the feature structure.

[0042] Heat 2000ml of deionized water to 85℃ in a water bath, then add 560g of nickel sulfate hexahydrate, 80g of nickel chloride hexahydrate, 80g of boric acid, and 10g of sodium saccharin in sequence, and finally stir thoroughly. During this process, add 5% ammonia water to adjust the pH of the Watt nickel plating solution to 4.0.

[0043] 12g of silicon carbide particles with an average particle size of 1μm and 6g of nickel particles with an average particle size of 50μm were dispersed in 2000ml of Watt's nickel electroplating solution and subjected to ultrasonic vibration and mechanical stirring for 45min to obtain silicon carbide composite electroplating solution.

[0044] The silicon carbide composite electroplating solution was poured into the electroplating tank of the magnetic field-induced electrodeposition machine and heated to 45°C using a water bath heating method. The solution was pumped at a flow rate of 200 L / h. The magnetic field strength on the surface of the cathode feature structure was controlled at 50 mT using a spatial magnetic mask. The nozzle scanning range was 30 mm, the scanning speed was 4 mm / s, the electrode gap was controlled at 2 mm, and the current density at the nozzle was controlled at 100 A / dm³. 2 The deposition time is 30 minutes;

[0045] Remove the space mask, then soak the obtained cross-scale heat dissipation coating in deionized water for 30 minutes. After that, take out the cross-scale heat dissipation coating and rinse it three times with deionized water. Finally, place the cross-scale heat dissipation coating in a ventilated place to air dry.

[0046] Implemented in Comparative Example 1: Multiscale thermal coating without added silicon carbide particles:

[0047] The difference between this comparative example and Example 2 is that no silicon carbide particles were added; only an electroplating solution containing nickel particles was prepared. Everything else is the same as in Example 2 and will not be repeated here.

[0048] Perform various performance analysis tests on the coating:

[0049] Surface morphology: The surface morphology of the multi-scale heat dissipation coating was observed using scanning electron microscopy. Comparative example 1 is... Figure 5 (a), Example 2 is Figure 5 (b) Both Comparative Example 1 and Example 2 exhibited a significant rough microstructure on their coating surfaces. Compared to Comparative Example 1, the rough microstructure on the surface of Example 2 was denser, and the heat dissipation area of ​​the coating surface was also increased.

[0050] Tissue structure analysis: Example 2 was analyzed using X-ray diffraction spectroscopy to determine its phase composition. The XRD pattern is shown below. Figure 6As shown. The nickel crystal planes are (111), (200), and (220), with a face-centered cubic structure, and the preferred orientation of the coating is (111). Peaks related to silicon carbide were also detected in the coating, proving that silicon carbide has been introduced into the coating.

[0051] Heat dissipation performance testing: The reflection method was used for testing. The infrared emissivity of the coating was measured using an infrared emissivity meter. The test wavelength was 8-14 μm. Figure 7 The infrared emissivity of the characteristic structural components of Example 1, Comparative Example 1, and Example 2 is shown. (Through...) Figure 7 As can be seen, the infrared emissivity of the coating in Comparative Example 1 (0.78) is significantly improved compared to that of the feature structure (0.12), indicating that the construction of the micron-level rough structure effectively enhances the heat dissipation performance of the feature structure. With the preparation of a new electroplating solution containing silicon carbide particles, the infrared emissivity of the surface of Example 2 prepared by the new electroplating solution system is further increased to 0.92, and the heat dissipation performance of the coating is further enhanced. In summary, through the synergistic effect of magnetic field-induced electrodeposition and spatial mask, a heat-dissipating coating with high infrared emissivity can be obtained, further improving the heat dissipation performance of the feature structure.

[0052] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A method for fabricating a multi-scale heat dissipation structure for spacecraft components, characterized in that, Additive manufacturing technology is used to print feature structures with millimeter-level grooves, and precision machining is performed on the millimeter-level groove feature structures within specific requirements. Non-metallic additive manufacturing technology is used to print corresponding spatial magnetic masks, and magnetic shapes with different magnetic field strengths can be placed below the spatial magnetic masks. A coating with a micron-level rough structure is prepared on the feature structures with millimeter-level grooves.

2. The method for fabricating a multi-scale heat dissipation structure for spacecraft components according to claim 1, characterized in that, The additive manufacturing technology is selected from selective laser sintering and selective laser melting; the millimeter-level groove shape of the feature structure is selected from rectangular, semi-circular and conical; the feature structure is selected from aluminum alloy, titanium alloy, nickel-based alloy and copper alloy. The groove feature structure needs to be precision machined to a surface roughness of ≤1μm.

3. The method for fabricating a multi-scale heat dissipation structure for spacecraft components according to claim 1, characterized in that, The non-metallic additive manufacturing technology is selected from photopolymerization molding technology or digital light processing technology; the solution is resin plus magnetic particles, the material of the magnetic particles is selected from neodymium iron boron and samarium cobalt, and the concentration of magnetic particles is 5-20g / L; the magnetic shaped part is 10-30mm long, 1-3mm wide, and 1-2mm high, and the material of the magnetic shaped part is selected from neodymium iron boron or samarium cobalt.

4. A method for preparing a multi-scale heat dissipation coating, applicable to the method for preparing a multi-scale heat dissipation structure for spacecraft components as described in claims 1-3, characterized in that, include: Step S1, Surface treatment of workpiece: Clean the feature structure with millimeter-level grooves with deionized water and alcohol in sequence, and dry them for later use; Step S2, Fabrication of spatial magnetic mask: Spatial magnetic mask corresponding to the feature structure is fabricated using non-metallic additive manufacturing technology; Step S3: Prepare the Watt's nickel plating solution: First, heat the deionized water, then add boric acid, nickel sulfate hexahydrate, and nickel chloride hexahydrate to the heated deionized water. Stir the solution thoroughly, and add a specific concentration of ammonia during this process to ensure the pH of the plating solution remains stable within a certain range. Step S4: Prepare the functional particle composite electroplating solution: Add the functional particles and ferromagnetic particles to the Watt nickel electroplating solution of step S2, and perform ultrasonic oscillation and mechanical stirring during the process, and then set it aside for later use. Step S5, Workpiece preparation: Install and fix the workpiece prepared in step S1 and the spatial magnetic mask prepared in step S2 on the worktable of the magnetic field induced electrodeposition manufacturing equipment. Step S6, preparation of cross-scale heat dissipation coating: The functional particle composite electroplating solution obtained in step S4 is transferred to the electroplating tank of the magnetic field induced electrodeposition preparation equipment to prepare a cross-scale heat dissipation coating. Step S7: Immersion, rinsing, and drying of the cross-scale heat dissipation coating: Immerse the cross-scale heat dissipation coating obtained in step S6 in deionized water, and then rinse it several times with deionized water to remove any residual electroplating solution from the surface of the cross-scale heat dissipation coating. Then place the resulting cross-scale heat dissipation coating in a ventilated area to air dry naturally.

5. The method for fabricating a multi-scale heat dissipation structure for spacecraft components according to claim 4, characterized in that, In step S3, the deionized water used to prepare the Watt's nickel plating solution is heated to 80-100℃; the amount of boric acid added is 10-60 g / L; the amount of nickel sulfate hexahydrate added is 220-280 g / L; and the amount of nickel chloride hexahydrate added is 10-60 g / L. Ammonia water with a mass fraction of 5-10% is added during the preparation of the Watt's nickel plating solution to maintain the pH of the plating solution at 3.6-4.

5.

6. The method for fabricating a multi-scale heat dissipation structure for spacecraft components according to claim 4, characterized in that, The functional particles used in step S4 are selected from silicon carbide, alumina, and iron oxide, and the addition range of functional particles is 3-9 g / L; the ferromagnetic particles are selected from nickel particles and iron particles, the particle size of the ferromagnetic particles is 10-50 μm, and the addition range of ferromagnetic particles in Watt's nickel plating solution is 2-8 g / L; the ultrasonic vibration frequency is 35-40 kHz, and the treatment time is 30-60 min; the mechanical stirring speed is 600-1200 r / min, and the treatment time is 30-60 min.

7. The method for fabricating a multi-scale heat dissipation structure for spacecraft components according to claim 4, characterized in that, The specific parameters for preparing the multi-scale heat dissipation coating in step S6 are as follows: the temperature of the functional particle composite electroplating solution is maintained at 40-60℃, and the flow rate is controlled at 160-300L / h; the current density at the nozzle is set to 60-140A / dm³. 2 The deposition time is set to 25-45 min, the magnetic field strength in the cathode deposition area is controlled at 20-80 mT by the space magnetic mask, the nozzle scanning speed is adjusted to 3-5 mm / s, and the gap between the nozzle and the workpiece is set to 1-3 mm.

8. A method for fabricating a multi-scale heat dissipation structure for a spacecraft component according to any one of claims 1-7, characterized in that, The aforementioned multi-scale heat dissipation coating further improves the heat dissipation performance of the feature structure by increasing the radiation surface area of ​​the groove; the multi-scale heat dissipation coating has a high average emissivity.

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