A method for mixing powders of the interlayer shell of a lunar base and the structure of the interlayer shell

Abstract

The present invention discloses a method for mixing powder of a sandwich shell of a lunar base and a sandwich shell structure. The sandwich shell includes inner and outer thin-walled corrugated disks. Before being transported to the lunar surface, the inner and outer thin-walled corrugated disks are shrunk into a disk state, and the two are divided into a number of circular cavities for accommodating reaction raw material powders by an annular isolation film. The first reaction raw material powder and the second reaction raw material powder are alternately arranged in the circular cavities, and magnetic powder is added to the first reaction raw material powder. During construction, the sandwich shell is unfolded into a conical shell state along the axial direction of the corrugated disk, the annular isolation film ruptures, the first reaction raw material and the second reaction raw material come into contact, a magnetic field is applied to the sandwich shell, the movement of the magnetic powder in the sandwich is controlled, and the reaction raw material powders are mixed. The heat-insulating layer reaction raw material is directly encapsulated in the shell structure, which is convenient for transportation. Magnetic powder is added to the reaction raw material, and the comprehensive action of gravity and magnetic field can effectively improve the uniformity and efficiency of the mixed powder.

Description

Technical Field

[0001] The present invention relates to the field of powder mixing, and specifically to a method for mixing powder of the sandwich shell of a lunar base and the structure of the sandwich shell. Background Art

[0002] The structure of a lunar base usually needs to withstand long-term ultraviolet radiation and huge temperature changes on the lunar surface. Directly transporting heat-insulating coatings to the moon may cause insufficient adhesion of existing high-temperature-resistant coatings at high temperatures, easily resulting in phenomena such as coating peeling, greatly reducing the heat-insulating effect of the base, and thus losing the protective effect against extreme environments. Therefore, it is very important to prepare a high-temperature-resistant coating that can be cured in the lunar environment on-site as a heat-insulating layer, and the coating should also have good adhesion and durability.

[0003] By transporting the reaction raw material powder to the moon and then preparing the high-temperature-resistant coating on-site from the reaction raw materials, powder mixing is required during the preparation of the high-temperature-resistant coating. In the prior art, Chinese Patent Application No. CN202410072826.2 discloses a method for high-efficiency powder mixing. The mixing method is to divide the powder into different feeding bins, perform depolymerization and crushing treatments through a mixing table and complete primary mixing, then quantitatively extract the powder through "windmill-shaped" grooves, and then perform weighing and multiple mixings in an umbrella-shaped mixing area, and finally converge to the mixing bin area to achieve uniform and efficient mixing of the powder. However, this powder mixing method requires the preparation of feeding bins and is not convenient for transportation to the moon. Existing powder mixing technologies mostly rely on mechanical stirring or vibration treatment, and these methods all require special mechanical equipment and are not suitable for transportation to the moon. Summary of the Invention

[0004] Object of the Invention: Aiming at the above disadvantages, the present invention provides a method for mixing powder of the sandwich shell of a lunar base and the structure of the sandwich shell, which is convenient for transporting high-temperature-resistant coatings and enables efficient mixing of raw material powders.

[0005] Technical solution: To solve the above problems, the present invention adopts a method for mixing powders in the sandwich shell of a lunar base. The sandwich shell includes an inner thin-walled corrugated disk located on the inner side and an outer thin-walled corrugated disk located outside the inner thin-walled corrugated disk. Before being transported to the moon, the inner thin-walled corrugated disk and the outer thin-walled corrugated disk shrink into a disk state, and a number of circular cavities for accommodating reaction raw material powders are divided between the inner thin-walled corrugated disk and the outer thin-walled corrugated disk by an annular isolation film. The reaction raw material powders include a first reaction raw material powder and a second reaction raw material powder, and the first reaction raw material powder and the second reaction raw material powder are alternately arranged in the circular cavities. Magnetic powder is added to the first reaction raw material powder; during construction, the sandwich shell expands along the axial direction of the corrugated disk into a conical shell state, the annular isolation film ruptures, the first reaction raw material and the second reaction raw material come into contact, a magnetic field is applied to the sandwich shell, the movement of the magnetic powder in the sandwich is controlled, and the reaction raw material powders are mixed.

[0006] Further, the magnetic powder is magnetic nanoparticles, made of superparamagnetic iron oxide material, with a particle size less than 30nm. Under the condition of an external magnetic field, it can be quickly magnetized, and the powder can quickly demagnetize after removing the external magnetic field, and there is no magnetic residue in the powder, and the powders do not attract each other due to their own magnetism.

[0007] Further, the magnetic powder is magnetic core-shell powder, and the magnetic core-shell powder includes a magnetic core and an epoxy resin shell. The magnetic core is magnetic nanoparticles, made of superparamagnetic iron oxide material, with a particle size less than 30nm. Under the condition of an external magnetic field, it can be quickly magnetized, and the powder can quickly demagnetize after removing the external magnetic field, and there is no magnetic residue in the powder, and the powders do not attract each other due to their own magnetism.

[0008] Further, the preparation method of the magnetic core-shell powder is as follows:

[0009] Disperse magnetic nanoparticle - Fe3O4 powder in absolute ethanol and perform ultrasonic stirring to obtain a dispersion;

[0010] Prepare an aqueous solution of silane coupling agent KH570, mix it with the dispersion and perform mechanical stirring for grafting reaction to obtain intermediate Fe3O4;

[0011] Redisperse the intermediate Fe3O4 in absolute ethanol, add azobisisobutyronitrile AIBN, then perform mechanical stirring and slowly dropwise add glycidyl methacrylate GMA for polymerization reaction to obtain modified Fe3O4;

[0012] Disperse the modified Fe3O4 in xylene and perform ultrasonic stirring to obtain mixture A;

[0013] Add epoxy resin to mixture A and perform ultrasonic stirring to obtain mixture B;

[0014] Add polyetheramine to mixture B, stir well and degas under vacuum, and cure for 24 hours to obtain magnetic core-shell powder.

[0015] Furthermore, the reaction raw material powder includes epoxy resin powder, silicone resin, curing agent, filler, flame retardant, accelerator, fish scale texture agent and leveling agent. The first reaction raw material is a mixed powder of magnetic powder, epoxy resin powder, silicone resin, curing agent and filler, and the second reaction raw material is a mixed powder of flame retardant, accelerator, fish scale texture agent and leveling agent.

[0016] Furthermore, the composition ratios of the first reaction raw material and the second reaction raw material in two adjacent annular cavities are: 31% by weight of epoxy resin powder, 15.5% by weight of silicone resin, 11% by weight of curing agent, 36% by weight of filler, 4.5% by weight of flame retardant, 0.5% by weight of accelerator, 0.2% by weight of fish scale texture agent, 1.3% by weight of leveling agent.

[0017] Furthermore, the annular isolation film uses a metal thin film aluminum with a thickness of less than 0.1 mm, and the annular isolation film is a fine fishing net shape.

[0018] Furthermore, a wound coil is provided on the inner wall of the inner thin-walled corrugated disk, and an electromagnetic field is formed by energizing the coil to control the movement of magnetic powder in the interlayer.

[0019] Furthermore, a magnetic rod is clamped by a robotic arm inside the inner thin-walled corrugated disk to form a magnetic field for controlling the movement of magnetic powder in the interlayer, and the robotic arm moves the magnetic rod to control the movement of magnetic powder.

[0020] The present invention also adopts an interlayer shell structure applying the above-mentioned powder mixing method for the lunar base interlayer shell, including an interlayer shell and a heat insulation layer between the inner thin-walled corrugated disk and the outer thin-walled corrugated disk of the interlayer shell. The heat insulation layer is obtained by irradiating the mixed reaction raw materials with a thermal radiation light source and then reacting and curing.

[0021] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: the reaction raw materials of the heat insulation layer are directly encapsulated in the shell structure, which is convenient for transportation. Magnetic powder is added to the reaction raw materials, and through the action of the magnetic field, the movement state of the powder can be effectively changed, enabling it to form a directional flow with the assistance of gravity, overcoming the physical limitations in traditional mixing methods. Especially when dealing with powders with magnetic characteristics, the magnetic field can not only make their movement more flexible, but also prompt different types of powders to redistribute more quickly in the interlayer space, thus significantly improving the mixing uniformity and achieving efficient and uniform mixing of the raw material powders.

[0022] By utilizing the effects of gravity and magnetic fields, the mixing uniformity of powder materials has been significantly improved. Compared with traditional methods, the mixing time is shortened. By using the combined effects of the sandwich structure and magnetic fields, the uniformity and efficiency of the mixed powders can be effectively enhanced. When directly mixing and curing the powders piled up after the isolation film is ruptured, only the mixed powders around some of the isolation films can be uniformly mixed. However, in this invention, through the guidance of magnetic powders, the powder materials can be quickly and uniformly mixed within the sandwich layer, ultimately improving the overall performance of the materials.

[0023] The superparamagnetic iron oxide material used for the magnetic powders can be quickly magnetized under the condition of an external magnetic field, and the powder can quickly demagnetize after removing the external magnetic field, and there is no magnetic residue in the powder. The powders will not attract each other due to their own magnetism, improving the utilization efficiency of the magnetic powders, and the performance of the final product is more stable. Secondly, this invention also has strong adaptability and flexibility, avoiding the use of complex mechanical devices and reducing the difficulty during transportation and deployment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic flow diagram of the powder mixing method in this invention.

[0025] Figure 2 It is a schematic diagram of the storage of reaction raw material powders when the lunar base shrinks in this invention.

[0026] Figure 3 It is a schematic diagram of the powder accumulation when the lunar base is just deployed in this invention.

[0027] Figure 4 It is a schematic diagram of the movement of magnetic powders attracted by a magnetic rod in this invention.

[0028] Figure 5 It is a schematic diagram of the preparation process of the magnetic core-shell powders in this invention.

[0029] Figure 6 It is a schematic diagram of the movement of magnetic powders attracted by the wound coils inside the base in this invention.

[0030] Figure 7 It is a schematic diagram after the powders are uniformly mixed in this invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Example 1

[0032] As Figure 1As shown in the figure, in a method for mixing powders of the sandwich shell of a lunar base in this embodiment, the first reaction raw material and the second reaction raw material are separately packed on both sides of a diaphragm. After the thin-walled corrugated disk is unfolded, the diaphragm ruptures, and the first reaction raw material and the second reaction raw material come into contact. A magnetic field is applied to the sandwich shell to control the movement of magnetic powders in the sandwich and mix the reaction raw material powders. The sandwich shell includes an inner thin-walled corrugated disk 1 located on the inner side and an outer thin-walled corrugated disk 2 located outside the inner thin-walled corrugated disk. The thin-walled corrugated disk is made of a high-strength and high-elasticity thin-walled titanium alloy material, which can shrink and unfold the corrugated disk. After unfolding, it forms a conical thin-walled structure. The inner thin-walled corrugated disk and the outer thin-walled corrugated disk together form a closed internal space, and the reaction raw materials are separately packed in the internal space through the diaphragm.

[0033] As Figure 2 shown in the figure, the sandwich is located between the inner and outer corrugated disks. Before being transported to the lunar surface, in order to fix the reaction raw materials of the heat insulation layer, the annular array isolation film 3 that separates various reaction raw materials is adhesively bonded to the thin walls of the corrugated disks on both sides. The sandwich is divided into many parts by the annular array isolation film. Each part is filled with a mixed powder composed of raw materials of two high-temperature resistant materials. The raw materials are separated by a fine mesh isolation film made of soft aluminum material. When the base is compressed, the aluminum film stands upright inside the heat insulation layer. The annular array isolation film adopts a fishing net structure; during the stretching process of the base, the aluminum film is pulled open together with the corrugated disk and is in an ideal circular shape. However, due to the low strength of aluminum, the film will be torn during the stretching process to form a ruptured film.

[0034] The annular isolation film uses an aluminum thin film with a thickness of less than 0.1 mm. The tensile strength of aluminum is relatively low, and as the thickness decreases, its tensile strength further decreases. When the corrugated disk is unfolded, the aluminum film needs to bear the axial tensile stress and the extrusion stress of the powders on both sides. The extremely thin aluminum film is prone to plastic deformation or even fracture during the stretching process. The diaphragm is designed as a fine fishing net shape, and there are a large number of geometric weak points at the intersections of its grids. During the unfolding process, the stress will concentrate at the grid edges or nodes, resulting in local tearing.

[0035] The types of raw materials of the thermosetting high-temperature resistant powder coating include epoxy resin powder, silicone resin, curing agent, filler, flame retardant, accelerator, fish roe sand pattern agent, and leveling agent. The ratio of the high-temperature resistant powder materials is: epoxy resin: 31% (weight percentage), silicone resin: 15.5%, curing agent: 11%, filler: 36% (mica powder and flatting barite are mixed in a ratio of 1:1), flame retardant: 4.5%, accelerator: 0.5%, fish roe sand pattern agent: 0.2%, leveling agent: 1.3%. Among them, epoxy resin powder, silicone resin, curing agent, and filler form mixed powder 1, and flame retardant, accelerator, fish roe sand pattern agent, and leveling agent form mixed powder 2. Magnetic powders are added to mixed powder 1. After the sandwich shell is transported to the destination and unfolded, the annular array isolation film 3 is torn, and mixed powder 1 and mixed powder 2 are stacked inside the sandwich. AsFigure 3 As shown, the parts of the raw materials that come into contact with each other under the action of gravity are mixed. Since there is no external force to promote the stirring of the powder, the powder mixing is uneven. Figure 3 This is only a schematic illustration of uneven powder mixing, not a schematic illustration of horizontal stratification of different mixed powders. In reality, the powder does not stratify horizontally in sequence.

[0036] A magnetic field is applied to the sandwich shell to control the movement of magnetic powder in the sandwich and mix the reaction raw material powder. The magnetic powder is magnetic nanoparticles made of superparamagnetic iron oxide material. Superparamagnetic iron oxide material is a special kind of magnetic nanoparticles with a particle size less than 30 nanometers. This material has unique superparamagnetism, that is, it can be quickly magnetized under the action of an external magnetic field, and can quickly demagnetize after the magnetic field is removed without leaving any magnetic residue. This property makes the powder particles not attract each other due to their own magnetism, thus avoiding the agglomeration phenomenon. This material is prepared by mechanical ball milling method. This method involves putting Fe3O4 coarse particles with a particle size of dozens of micrometers into a ball mill, and making the Fe3O4 particles undergo plastic deformation and rupture through mechanical impact, so as to be refined into nanoscale Fe3O4 particles with superparamagnetic properties.

[0037] As Figure 4 shown, the magnetic field is formed by a robotic arm holding a magnetic rod 7. The robotic arm holding the magnetic rod 7 swings in the base space. The magnetic moment of the magnetic powder will quickly align with the magnetic field direction. The interaction between the magnetic moment of the magnetic powder and the external magnetic field makes the magnetic powder move along the magnetic field direction. By adjusting the robotic arm to adjust the position of the magnetic rod, the movement trajectory of the magnetic powder can be controlled, and a stirring effect is produced on the rest of the powder body, promoting the uniform mixing of the powder accumulated together due to the action of gravity. The schematic diagram of the powder after uniform mixing is as Figure 7 shown. After the powder is mixed, a thermal radiation light source is arranged inside the base. Under the irradiation of the light source, the mixed raw materials are quickly solidified to form a uniform and firm high-temperature resistant material, thus forming the heat insulation layer of the sandwich shell structure of the lunar base.

[0038] Example 2

[0039] In this example, the same sandwich shell structure and thermosetting high-temperature resistant powder coating raw materials as those in the powder mixing method of the lunar base sandwich shell described in Example 1 are adopted. The difference from Example 1 is that the magnetic powder is magnetic core-shell powder, and the magnetic core-shell powder includes a magnetic core and an epoxy resin shell. The magnetic core is magnetic Fe3O4 nanoparticles, and the same superparamagnetic iron oxide material as that in Example 1 is used. As Figure 5As shown, the preparation method of the magnetic core-shell powder is as follows: Fe₃O₄ is dispersed in anhydrous ethanol and ultrasonically stirred to obtain a dispersion. An aqueous solution of silane coupling agent KH570 is prepared, mixed with the dispersion, and mechanically stirred for a grafting reaction to obtain an intermediate Fe₃O₄. The intermediate Fe₃O₄ is redispersed in anhydrous ethanol, and after adding azobisisobutyronitrile (AIBN), mechanical stirring is performed while glycidyl methacrylate (GMA) is slowly added dropwise for polymerization to obtain modified Fe₃O₄. The modified Fe₃O₄ is dispersed in xylene and ultrasonically stirred to obtain a mixed solution A. Epoxy resin is added to mixed solution A and ultrasonically stirred to obtain a mixed solution B. Then, polyetheramine is added, stirred thoroughly, and vacuum degassing is performed. The mixture is cured for 24 hours to obtain a Fe₃O₄ epoxy resin composite powder, i.e., the magnetic core-shell powder.

[0040] Example 3

[0041] One embodiment of this embodiment adopts the same sandwich shell structure and thermosetting high-temperature resistant powder coating raw materials as in the powder mixing method of the moon base sandwich shell described in Example 1, and adds the same magnetic powder as in Example 1 to the mixed powder 1. The difference from Example 1 is that the magnetic field is formed by arranging a coil wound on the inner wall of the inner thin-walled corrugated disk and energizing the coil, such as Figure 6 As shown, the coil 8 is wound inside the base space, and the two ends of the coil are connected to the battery. After power is turned on, the wound coil generates an electromagnetic field, and the paramagnetic powder immediately generates magnetism and moves along the direction of the magnetic field. After a period of time, the positive and negative poles of the coil connection ends are changed, and the direction of the magnetic field changes accordingly, and the magnetic powder continues to move along the new direction of the magnetic field. At the same time, the number of turns of the coil winding is increased or decreased to achieve the effect of increasing or decreasing the size of the magnetic field. According to this method, the direction and size of the magnetic field are changed many times, and finally the magnetic powder is evenly mixed, and a stirring effect is produced on the remaining powders, promoting the uniform mixing of the powders piled together due to gravity. This process can be carried out in the lunar environment without complex mechanical devices or human intervention, so that the mixture can form a layer of uniform, strong, high-temperature resistant material in a short time, such as Figure 7 shown.

[0042] Example 4

[0043] One of the embodiments in this embodiment adopts the same sandwich shell structure and thermosetting high-temperature resistant powder coating raw materials in the lunar base sandwich shell powder mixing method described in Example 2, and adds the same magnetic powder as Example 2 to the mixed powder 1. The difference from Example 2 is that the magnetic field is realized through the structure in Example 3.

Claims

1. A powder mixing method for a lunar base sandwich shell, characterized in that: The sandwich shell includes an inner thin-walled corrugated disk located on the inner side and an outer thin-walled corrugated disk located on the outer side of the inner thin-walled corrugated disk. The heat insulation layer reaction raw materials are directly encapsulated in the shell structure. Before being transported to the lunar surface, the inner thin-walled corrugated disk and the outer thin-walled corrugated disk are shrunk into a disc state, and the inner thin-walled corrugated disk and the outer thin-walled corrugated disk are divided into several annular cavities for accommodating reaction raw material powder by an annular isolation membrane. The reaction raw material powder is used to prepare high-temperature resistant coatings. The reaction raw material powder includes a first reaction raw material powder and a second reaction raw material powder. The first reaction raw material powder includes a second reaction raw material powder and a third reaction raw material powder. A first reaction raw material powder and a second reaction raw material powder are alternately arranged in an annular cavity. The annular isolation membrane is in the shape of a fine fishing net. The annular isolation membrane adapts to the expansion of the shell structure during the deployment of the lunar base. Magnetic powder is added to the first reaction raw material powder, and the magnetic powder is made of superparamagnetic iron oxide material. During construction, the sandwich shell is axially expanded into a conical shell state along the corrugated disk, the annular isolation membrane is broken, the first reaction raw material and the second reaction raw material come into contact, a magnetic field is applied to the sandwich shell, the movement of the magnetic powder in the sandwich is controlled, and the reaction raw material powders are mixed.

2. The powder mixing method for the lunar base sandwich shell according to claim 1, characterized in that: The magnetic powder is a magnetic nanoparticle with a particle size of less than 30nm. It can be quickly magnetized under the condition of an external magnetic field. When the external magnetic field is removed, the powder can be quickly demagnetized. There is no magnetic residue in the powder, and the powders will not attract each other due to their own magnetism.

3. The powder mixing method for the lunar base sandwich shell according to claim 1, characterized in that: The magnetic powder is a magnetic core-shell powder, which includes a magnetic core and an epoxy resin shell. The magnetic core is a magnetic nanoparticle made of superparamagnetic iron oxide material with a particle size of less than 30nm. It can be quickly magnetized under the condition of an external magnetic field. When the external magnetic field is removed, the powder can be quickly demagnetized, and the powder has no magnetic residue. The powders will not attract each other due to their own magnetism.

4. The powder mixing method for the lunar base sandwich shell according to claim 3, characterized in that: The preparation method of the magnetic core-shell powder is: The magnetic nanoparticle Fe3O4 powder is dispersed in anhydrous ethanol and ultrasonically stirred to obtain a dispersion; A silane coupling agent KH570 aqueous solution was prepared, mixed with the dispersion and mechanically stirred to carry out a grafting reaction to obtain intermediate Fe3O4; The intermediate Fe3O4 was redispersed in anhydrous ethanol, and after adding azobisisobutyronitrile (AIBN), mechanical stirring was performed and glycidyl methacrylate (GMA) was slowly added dropwise to carry out polymerization reaction to obtain modified Fe3O4. The modified Fe3O4 was dispersed in xylene and ultrasonically stirred to obtain a mixed solution A; Adding epoxy resin to mixed solution A and stirring with ultrasonic waves to obtain mixed solution B; Polyetheramine was added to the mixed solution B, and the mixture was fully stirred and vacuum degassed, and then cured for 24 hours to obtain magnetic core-shell powder.

5. The powder mixing method for the lunar base sandwich shell according to claim 2 or 3, characterized in that: The reaction raw material powder includes epoxy resin powder, silicone resin, curing agent, filler, flame retardant, accelerator, fish roe sand grain agent and leveling agent. The first reaction raw material is a mixed powder of magnetic powder, epoxy resin powder, silicone resin, curing agent and filler. The second reaction raw material is a mixed powder of flame retardant, accelerator, fish roe sand grain agent and leveling agent.

6. The powder mixing method for the lunar base sandwich shell according to claim 5, characterized in that: The composition ratio of the first reaction raw material and the second reaction raw material in two adjacent annular cavities is: 31% by weight of epoxy resin powder, 15.5% by weight of silicone resin, 11% by weight of curing agent, 36% by weight of filler, 4.5% by weight of flame retardant, 0.5% by weight of accelerator, 0.2% by weight of fish roe sand grain agent and 1.3% by weight of leveling agent.

7. The powder mixing method for the lunar base sandwich shell according to claim 1, characterized in that: The annular isolation membrane is made of aluminum metal film with a thickness of less than 0.1 mm.

8. The powder mixing method for the sandwich shell of the lunar base according to claim 1, characterized in that: A winding coil is provided on the inner wall of the inner thin-wall corrugated disk, and an electromagnetic field is formed by energizing the coil to control the movement of magnetic powder in the interlayer.

9. The powder mixing method for the sandwich shell of the lunar base according to claim 1, characterized in that: The magnetic rod is clamped by a robotic arm and located inside the inner thin-wall corrugated disk, forming a magnetic field that controls the movement of magnetic powder in the interlayer. The robotic arm moves the magnetic rod to control the movement of magnetic powder.

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