A satellite payload anti-radiation device made of an aluminum-tantalum metal composite material

Abstract

The present invention relates to the field of aerospace technology, and particularly relates to a satellite payload anti-radiation device made of an aluminum-tantalum metal composite material, comprising: an electronics box including a bottom plate and a main structure skeleton; side plates covering the outer side surfaces of the main structure skeleton; a top cover plate covering the top of the main structure skeleton; and a printed circuit board assembly installed inside the main structure skeleton; wherein the side plates and the top cover plate are respectively rolled from aluminum-tantalum composite laminated plates; and the bottom plate and the main structure skeleton of the electronics box are integrally formed by engraving and milling an aluminum ingot. The satellite payload anti-radiation device made of the aluminum-tantalum metal composite material provided by the present invention, compared with the satellite payload anti-radiation device made of traditional 2A12 aluminum alloy, can improve the anti-radiation ability while ensuring sufficient structural strength and good anti-mechanical ability under the condition of the same areal density.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and particularly relates to a satellite payload anti-radiation device made of an aluminum-tantalum metal composite material. Background Art

[0002] When a satellite payload operates in orbit, its electronic components will face radiation threats such as galactic cosmic rays, radiation belt protons, electrons, and solar high-energy particles, and also need to meet the harsh vacuum environment requirements of alternating high and low temperatures. During launch, it also needs to adapt to the mechanical environments such as the random vibration and shock of the launch vehicle. Therefore, the payload equipment not only needs to have anti-radiation capabilities but also ensure sufficient structural strength and good anti-mechanical capabilities.

[0003] At present, most of the satellite payloads in China use 2A12 aluminum alloy to prepare the electronics chassis. 2A12 aluminum alloy has a relatively small relative density, high strength, good mechanical properties, good thermal conductivity and heat resistance, and can also enhance the anti-corrosion ability through anodic oxidation. It has been widely used in space engineering tasks.

[0004] Although traditional 2A12 aluminum alloy has sufficient structural strength and mechanical properties, its anti-radiation efficiency is low and the protection quality cost is high. Although it has a certain shielding effect on the radiation in space, it is still difficult to meet the anti-radiation reinforcement requirements of medium and high orbit navigation and communication satellites and deep space exploration satellites. If you want to achieve an ideal protection effect, you need to increase a certain thickness, but this will also bring an unacceptable mass cost. For example, to control the radiation dose encountered by a spacecraft in the MEO orbit within 10 years to less than 100 krad[Si], at least 7 mm of aluminum alloy material is required, and the mass cost is hundreds of kilograms; in 2013, in order to cope with the strong radiation of the Jupiter system, NASA's JUNO Jupiter probe used a titanium alloy with a thickness of 10 mm and a weight of 180 kg and a local tantalum shielding box for radiation composite shielding protection. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problem of low radiation shielding efficiency of the traditional satellite payload electronics chassis in the prior art, and thus provide a satellite payload anti-radiation device made of an aluminum-tantalum metal composite material.

[0006] To solve the above technical problems, the satellite payload anti-radiation device made of an aluminum-tantalum metal composite material provided by the technical solution of the present invention includes:

[0007] An electronics box, including a bottom plate and a main structure skeleton;

[0008] Side plates, covering the outer side surfaces of the main structure skeleton;

[0009] A top cover plate, covering the top of the main structure skeleton; and

[0010] A printed circuit board assembly is installed inside the main structure framework; among which,

[0011] The side plates and the top cover plate are respectively rolled from aluminum tantalum composite laminated plates;

[0012] The bottom plate of the electronics box and the main structure framework are integrally formed by engraving and milling an aluminum ingot.

[0013] As an improvement of the above device, the electronics box is a cuboid; the side plates include: a front side plate, a rear side plate, a left side plate, and a right side plate that respectively cover and are connected to the four outer side surfaces of the main structure framework.

[0014] As an improvement of the above device, the bottom plate of the electronics box is provided with lugs integrally formed with the bottom plate;

[0015] The thickness of the bottom plate is 5 mm, the roughness is less than or equal to 3.2 μm, and the flatness is less than or equal to 0.1 mm / 100 mm×100 mm.

[0016] As an improvement of the above device, the printed circuit board assembly includes: a first printed circuit board, a second printed circuit board, and a third printed circuit board; among which, the first printed circuit board is connected to the bottom plate; the second printed circuit board and the third printed circuit board are connected to the main structure framework; among which, the second printed circuit board and the third printed circuit board are both provided with reinforcing ribs.

[0017] As an improvement of the above device, the thicknesses of the first printed circuit board, the second printed circuit board, and the third printed circuit board are all 2 mm, and the thicknesses of the reinforcing ribs are all 6 mm.

[0018] As an improvement of the above device, the aluminum tantalum composite laminated plate is obtained through the following process:

[0019] Surface treatment: Perform surface treatment on the 2A12 aluminum alloy plate and the Ta-2.5W tantalum tungsten alloy plate to remove the surface oxide film and impurities, and obtain an initial clean surface with a preset roughness;

[0020] Slab non-isothermal heating: Heat the 2A12 aluminum alloy plate and keep the original temperature of the Ta-2.5W tantalum tungsten alloy plate;

[0021] Stacking and blank forming: After heating the 2A12 aluminum alloy plate, bond the initial clean surfaces of the 2A12 aluminum alloy plate and the Ta-2.5W tantalum tungsten alloy plate together to form an aluminum tantalum composite laminated plate.

[0022] As an improvement of the above device, the thickness of the aluminum tantalum composite laminated plate is 2 mm, among which, the thickness of the 2A12 aluminum alloy plate is 1.6 mm, and the thickness of the Ta-2.5W tantalum tungsten alloy plate is 0.4 mm.

[0023] As an improvement of the above device, the rolling process is as follows:

[0024] Rolling and compounding the aluminum-tantalum composite laminated plate, and performing heat treatment on the rolled aluminum-tantalum composite laminated plate; wherein, the heat treatment includes: solution treatment and aging heat treatment.

[0025] As an improvement of the above device, after the heat treatment, it further includes treating the surface of the aluminum-tantalum composite laminated plate with a black anodic oxidation surface treatment process to form an oxide film on the surface.

[0026] Compared with the prior art, the advantages of the present invention are that the satellite payload anti-radiation device made of aluminum-tantalum metal composite material provided by the present invention has broken through a number of key technologies such as the rational design technology of composite material anti-radiation, the load application technology of aluminum-tantalum composite material, and the space environment adaptation technology of aluminum-tantalum heterogeneous metal composite material. By simulating and designing the optimal ratio of aluminum-tantalum composite material through GENANT4 software, and hot rolling it into a composite material plate with an aluminum-tantalum metal laminated structure to replace the traditional 2A12 aluminum alloy to make the electronics chassis of the satellite payload. Under the same areal density, while ensuring sufficient structural strength and good anti-mechanical ability, the anti-radiation ability is improved. The present invention uses aluminum-tantalum metal composite material to make the satellite payload electronics chassis, which can effectively reduce the cumulative ionization radiation dose of the internal components of the electronics box and improve the anti-radiation ability. Brief Description of the Drawings

[0027] Figure 1 It is a schematic diagram of the satellite payload anti-radiation device made of aluminum-tantalum metal composite material of the present invention;

[0028] Figure 2 It is the response curve of the vibration monitoring point in the X direction;

[0029] Figure 3 It is the response curve of the vibration monitoring point in the Y direction;

[0030] Figure 4 It is the response curve of the vibration monitoring point in the Z direction;

[0031] Figure 5 It is the temperature nephogram of the power supply component;

[0032] Figure 6 It is the temperature nephogram of the main control unit component;

[0033] Figure 7 It is the shielding dose of the composite material under 2mm equivalent thickness.

[0034] Reference Signs of the Drawings

[0035] 1 - Front side plate, 2 - Left side plate, 3 - Rear side plate, 4 - Right side plate, 5 - Top cover plate, 6 - Third printed circuit board, 7 - First printed circuit board, 8 - Electronics box. Detailed implementation mode

[0036] The technical solution provided by the present invention will be further described below in conjunction with embodiments.

[0037] This embodiment provides a satellite payload anti - radiation device made of aluminum - tantalum metal composite material, and its structure is as Figure 1 shown, including a front side plate 1, a left side plate 2, a rear side plate 3, a right side plate 4, a top cover plate 5, a third printed circuit board 6, a second printed circuit board (not shown in the figure), a first printed circuit board 7, and an electronics box 8. The electronics box 8 includes a bottom plate and a main structure skeleton.

[0038] The bottom plate and the main structure skeleton of the electronics box 8 are of an integral structure and are milled from a whole aluminum ingot.

[0039] In this embodiment, the overall structure form of the electronics box 8 is a cuboid, and the main structure skeleton is respectively connected to one side plate. In other embodiments, the electronics box 8 can also be of other shapes and be installed with more than 4 side plates.

[0040] In this embodiment, the front side plate 1, the rear side plate 3, the left side plate 2, and the right side plate 4 are connected to the main structure skeleton by M3 screws.

[0041] The bottom plate of the electronics box 8 is provided with mounting lugs for connecting to the satellite platform. During installation, the bottom plate is connected to the satellite platform by 4 M4 screws passing through the mounting lugs. The bottom plate of the electronics box 8 and the mounting lugs are integral. The thickness of the bottom plate is 5 mm, the roughness is less than or equal to 3.2 μm, and the flatness is less than or equal to 0.1 mm / 100 mm×100 mm. The mounting lugs are used for installation with the platform interface. The thickness of the four lugs is 5 mm, and the mounting hole diameter is 5.5 mm. The electrical connector is installed and led out from the front panel. The payload mark is a diamond - shaped frame engraving and is located on the front panel of the chassis.

[0042] A total of 3 printed circuit boards are designed for the anti - radiation device. The lowermost first printed circuit board 7 is directly fixed to the structural bottom plate by 8 M3 screws. For the two upper circuit boards to improve mechanical properties, 6 - mm - thick 2A12 aluminum alloy structural ribs are used for reinforcement and fixation during design (not shown in the figure), and then the PCB structural ribs are fixed to the main structure skeleton by M3 screws. The thicknesses of the first printed circuit board, the second printed circuit board, and the third printed circuit board are all 2 mm, and the thicknesses of the ribs are all 6 mm, ensuring sufficient strength and stiffness. Figure 1 Shows the installation schematic diagram of the lowermost first printed circuit board 7 and the uppermost third printed circuit board 6.

[0043] The present invention uses a composite rolling of three materials, namely aluminum, tungsten, and tantalum, to form a new alloy laminated composite material plate, which is used to make the shielding structure side plates and cover plates.

[0044] Among them, the side plates include: front side plate 1, rear side plate 3, left side plate 2, and right side plate 4. The cover plate is the top cover plate 5. The side plates and the cover plate are made of 5 pieces of 2-mm-thick aluminum-tantalum composite laminated materials rolled through multiple processes. The aluminum-tantalum composite laminated material consists of 1.6-mm 2A12 aluminum alloy and 0.4-mm aluminum-tantalum alloy, and a small amount of metallic tungsten is added during the high-temperature rolling process. In order to improve the corrosion resistance and heat conduction characteristics of the outermost layer of aluminum metal in the composite material, a black anodizing solution is used for surface treatment. The side plates and the top plate are fixed to the structural ribs by M3 screws.

[0045] The thicknesses of the printed circuit board, the reinforcing rib, and the side plate are all preferred dimensions for balancing strength and weight.

[0046] The main technical means and specific steps are as follows:

[0047] 1: Surface treatment: Use a mechanical and chemical method to perform surface treatment on the 2A12 aluminum alloy and Ta-2.5W alloy plates to obtain an initial clean surface without oxide film, oil stain, and other impurities, and form a certain roughness (0.1 - 50 μm).

[0048] 2: Slab non-isothermal heating: Heat the 2A12 aluminum alloy plate, and do not heat the Ta-2.5W alloy plate.

[0049] 3: Stacking and blank forming: After heating the 2A12 aluminum alloy, clean the surfaces of the 2A12 aluminum alloy plate and the surface-treated Ta-2.5W alloy plate and bond them together to form a combined structure of 2A12 / Ta-2.5W alloy composite blank.

[0050] 4: Rolling composite: Perform rolling composite on the assembled 2A12 / Ta-2.5W alloy composite blank. The rolling system mainly includes the single-pass reduction, the number of rolling passes, and the coordination between various process parameters.

[0051] 5: Heat treatment: Perform solution + aging heat treatment on the aluminum / tantalum laminated composite material to improve the overall performance.

[0052] Black anodizing is a surface treatment process for the load chassis. In an acidic electrolyte, non-ferrous metals such as aluminum and magnesium are used as anodes for electrolysis to form a dense oxide film on the material surface, improving the corrosion resistance and wear resistance. For black anodizing, black dyes are filled on the anodized surface, which is for the heat conduction characteristics of the chassis.

[0053] The 2A12 aluminum alloy material widely used in current satellite payload chassis not only has excellent mechanical and thermal properties, but also has a very important point: good casting performance and plastic processing performance. Cast aluminum alloy is melted from the ingredients and then cast into blanks by die casting with a mold, and then machined into structural components of any shape and thickness by CNC milling according to the mission and design requirements. The aluminum-tantalum metal composite material applied in the present invention is a 2A12 / Ta-2.5W alloy composite blank rolled and compounded with the latest breakthrough. Limited by the thickness of the composite material plate (total thickness 2mm, 1.6mm Al and 0.4mm Ta) and the particularity of being not easy to bend and shape, the present invention innovatively applies the aluminum-tantalum metal composite material plate as the side plate and the cover plate to match the structural skeleton made of 2A12 aluminum alloy to form a satellite payload chassis. In order to ensure sufficient structural strength, good anti-mechanical ability and improve the anti-radiation ability to meet the requirements of on-orbit applications, the following simulation and test analysis are carried out:

[0054] In the mechanical finite element modeling analysis, the maximum stress value on the structure in the random vibration is 3.9 MPa, which occurs in the y-direction vibration condition. According to the random vibration theory, the probability of the stress in the structure being 3 times the root mean square value of the stress is 0.03%, that is, in 99.97% of the cases, the maximum stress value is not higher than 3 times the root mean square value of the stress. Thus, the maximum stress value of the structure during vibration is:

[0055] 3 * 3.9 = 11.7 MPa

[0056] The aluminum-tantalum composite material plate used in the chassis structure has a tensile strength of 498 MPa, meeting the theoretical strength requirements. In the sine vibration simulation analysis of the structure, the maximum stress value on the structure is 0.34 MPa, which occurs in the z-direction vibration condition. The aluminum-tantalum composite material plate used in the chassis structure has a tensile strength of 498 MPa, meeting the theoretical strength requirements. This has also been verified in the subsequent vibration environment test Figure 2 shows the response curve of the monitoring point in the X-direction vibration of the random vibration test, Figure 3 shows the response curve of the monitoring point in the Y-direction vibration of the random vibration test, Figure 4 shows the response curve of the monitoring point in the Z-direction vibration of the random vibration test; as Figures 2 - 4 shown, the satellite payload anti-radiation device made of the aluminum-tantalum metal composite material provided by the present invention meets the satellite design and construction specifications and mechanical test requirements.

[0057] In the ICEPAK thermal simulation analysis results, the simulated temperature of the chassis is shown in Table 1, and the heat dissipation of each component in Table 1 is the maximum heat dissipation of the device and the PCB board. The temperature contour maps of each component are as Figures 5 - 6 shown. According to the derating temperature of the device of 85 °C, the temperature of the main control unit component is 86.1 °C, slightly exceeding the operating temperature, and the devices of other components meet the operating requirements.

[0058] Table 1: Summary of Simulated Temperatures of High-Power Devices for Each Module

[0059] Module Name Heat Dissipation (W) Simulated Temperature (°C) Temperature Rise (°C) Power Supply Component 1.3 82.7 12.7 Main Control Unit Component 0.8 86.1 16.1

[0060] In the subsequent thermal cycle test assessment, there were no visible changes in the appearance and structure of the chassis before and after the test. The situation during the test met the standard requirements, the test equipment satisfied the requirements of the test environment, no deviations beyond the limits occurred, and the functions of the test equipment were all normal.

[0061] In the composite material shielding analysis, for the low Earth orbit (LEO) Figure 7 Figure and Table 2 show the shielding effects of Al / Ta composite materials with different ratios under an equivalent 2 mm Al on radiation belt electrons and radiation belt protons. It can be seen from the figure that as the Al content increases, the shielding effect on radiation belt electrons becomes worse, while the shielding effect on radiation belt protons becomes better, and the final comprehensive protection effects are not very different.

[0062] Table 2: Shielding Doses of Composite Materials under an Equivalent Thickness of 2 mm

[0063]

[0064] Based on the traditional payload anti-radiation device made of 2A12 aluminum alloy, for the physical scenario of the satellite payload receiving radiation dose in orbit for a long time, through innovative design, a new alloy laminated composite material plate made by compound rolling of aluminum, tungsten, and tantalum materials is used to replace the original 3 mm aluminum alloy front panel, rear panel, left panel, right panel, and cover plate, almost shielding all incident directions of charged particles (the bottom surface is composed of 5 mm aluminum alloy with good shielding effect), greatly improving the radiation shielding effect. In the radiation environment of typical orbits, the outer layer of aluminum alloy material reduces the speed of most energetic electrons, the middle layer of tungsten material blocks most of the bremsstrahlung radiation, and the inner layer of tantalum material can absorb the secondary electrons and bremsstrahlung radiation generated by the tungsten material, forming a good dose shielding effect. Through the calculation and analysis results of the shielding effect, in the structural design with the same areal density, the Al / W / Ta alloy laminated composite material has a 70% improvement in anti-radiation ability compared with the traditional 2A12 aluminum alloy.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A satellite payload radiation-resistant device made of aluminum-tantalum metal composite material, comprising: Electronic box, including bottom plate and main structure frame; Side panels, covering the outer side of the main structural frame; The top cover plate covers the top of the main structural frame; and The printed circuit board assembly is installed in the main structure frame; wherein, The side plates and top cover plates are respectively formed by rolling aluminum-tantalum composite layered plates; The bottom plate and the main structural frame of the electronic box are integrally formed by engraving and milling of aluminum ingots; The aluminum-tantalum composite layered plate is obtained by the following process: Surface treatment: Surface treatment is performed on 2A12 aluminum alloy plates and Ta-2.5W tantalum-tungsten alloy plates to remove surface oxide films and impurities and obtain an initial clean surface with a preset roughness; Different temperature heating of slab: heating the 2A12 aluminum alloy plate and maintaining the original temperature of the Ta-2.5W tantalum-tungsten alloy plate; Stacking and assembly: after heating the 2A12 aluminum alloy plate, the initial clean surfaces of the 2A12 aluminum alloy plate and the Ta-2.5W tantalum-tungsten alloy plate are laminated together to form an aluminum-tantalum composite layered plate; The thickness of the aluminum-tantalum composite layered plate is 2 mm, wherein the thickness of the 2A12 aluminum alloy plate is 1.6 mm, and the thickness of the Ta-2.5W tantalum-tungsten alloy plate is 0.4 mm; The printed circuit board assembly includes: a first printed circuit board, a second printed circuit board and a third printed circuit board; wherein the first printed circuit board is connected to the base plate; the second printed circuit board and the third printed circuit board are connected to the main structure skeleton; wherein the second printed circuit board and the third printed circuit board are both provided with reinforcing ribs.

2. The satellite payload radiation resistant device of aluminum-tantalum metal composite material according to claim 1 is characterized in that: The electronic box is a rectangular parallelepiped; The side panels include: a front side panel, a rear side panel, a left side panel and a right side panel which respectively cover the four outer side surfaces of the main structure frame and are connected to the corresponding outer side surfaces.

3. The satellite payload radiation resistant device of aluminum-tantalum metal composite material according to claim 1 is characterized in that: The bottom plate of the electronic box is provided with a lug integrally formed with the bottom plate; The bottom plate has a thickness of 5 mm, a roughness of less than or equal to 3.2 μm, and a flatness of less than or equal to 0.1 mm / 100 mm×100 mm.

4. The satellite payload radiation resistant device of aluminum-tantalum metal composite material according to claim 1 is characterized in that: The thickness of the first printed circuit board, the second printed circuit board and the third printed circuit board are all 2 mm, and the thickness of the reinforcing ribs are all 6 mm.

5. The satellite payload radiation resistant device of aluminum-tantalum metal composite material according to claim 1 is characterized in that: The rolling process is as follows: The aluminum-tantalum composite layered plate is rolled and composited, and the rolled aluminum-tantalum composite layered plate is heat treated; wherein the heat treatment includes: solution treatment and aging heat treatment.

6. The satellite payload radiation resistant device of aluminum-tantalum metal composite material according to claim 5 is characterized in that: After the heat treatment, the surface of the aluminum-tantalum composite layered plate is treated by a black anodizing surface treatment process to form an oxide film on the surface.

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