Methods for connecting dissimilar metals in sheet metal mesh and surface tension storage tanks

Abstract

This invention provides a method for joining dissimilar metals in a metal joining process and a surface tension tank. The specific steps are as follows: S1, clamping multiple aluminum alloy perforated plates and stainless steel mesh using tooling; S2, clamping the assembled workpiece between the upper and lower electrodes of a roll welding machine; S3, welding the upper and lower electrodes together circumferentially. This invention features a simple process; the connection between the aluminum alloy perforated plates and stainless steel mesh requires only one clamping and one welding operation to form the mesh assembly, solving the problem of multiple clamping and welding operations required for traditional titanium alloy perforated plates and stainless steel mesh. It is also low-cost, as it does not require a vacuum environment, the forming and welding of the aluminum alloy perforated plates and stainless steel mesh involves fewer steps, has lower welding environment requirements, and the unit price of aluminum alloy is lower. Furthermore, it has a lower mass; aluminum alloy has a lower density, resulting in a smaller mass for the same thickness as titanium alloy.

Description

Technical Field

[0001] This invention relates to the field of metal joining methods, specifically to a method for joining dissimilar metals in a plate mesh and a surface tension tank. It is primarily used for joining aluminum alloy perforated plates and stainless steel screens, and the formed components can be used as liquid propellant management devices in aerospace applications such as satellites, spacecraft, and space stations. Background Technology

[0002] Surface tension tanks are tanks that manage propellants using the surface tension of liquids. Because they have no relatively moving parts during operation, they have advantages such as high reliability, long service life, and light weight, making them the preferred solution for liquid propulsion systems.

[0003] The core technology of the surface tension tank is its internal propellant management device (PMD). The PMD can manage liquids in a microgravity environment. The management capability of the PMD is a key indicator of the tank's performance. The design specification of the PMD is to reliably and without entrainment of liquids at any stage.

[0004] Currently, domestic surface tension storage tanks (PMDs) are still mainly of mesh structure, meaning the PMD is assembled from different screen components. Since stainless steel is the primary material for screens both domestically and internationally, and its manufacturing process is the most mature, while the perforated plates are mainly made of titanium alloy, the two materials have similar melting points, making welding relatively easy. The connection method is as follows: First, a stainless steel screen is roll-welded to a titanium alloy perforated plate using a roll welding machine. Then, the rolled-welded titanium alloy perforated plate and stainless steel screen assembly are assembled with another titanium alloy perforated plate, and edge sealing is performed using electron beam or argon arc welding. This connection method has the following disadvantages: First, the connection method involves multiple welding processes, such as roll welding followed by electron beam or argon arc welding. Furthermore, to prevent oxidation during welding, electron beam or argon arc welding must be performed in a vacuum environment, making the connection method complex, time-consuming, and labor-intensive. Second, the unit price of titanium alloy is relatively high, resulting in high costs. Third, compared to aluminum alloys and composite materials, titanium alloys have a higher density, resulting in a larger mass per unit volume of the connecting components.

[0005] In recent years, with the rapid development of applications in fields such as spacecraft, ships, and instruments, there has been a growing demand for lighter and lower-cost surface tension tanks. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for connecting dissimilar metals in a plate mesh and a surface tension storage tank.

[0007] According to the present invention, a method for connecting dissimilar metals in a mesh is provided, and the specific steps are as follows:

[0008] S1. Clamp multiple aluminum alloy perforated plates and stainless steel screens using tooling;

[0009] S2. Clamp the assembled workpiece between the upper and lower electrodes on the roll welding machine;

[0010] S3. The upper and lower electrodes are welded together in the circumferential direction to form the shape.

[0011] In some embodiments, the wall thickness of the aluminum alloy perforated plate is 0.2-3 mm.

[0012] In some embodiments, the number of aluminum alloy perforated plates is 2-4.

[0013] In some embodiments, the aluminum alloy perforated plate has holes inside, and the distance between the outermost holes and the edge is not less than 3mm.

[0014] In some embodiments, stainless steel screens are assembled between aluminum alloy perforated plates.

[0015] In some embodiments, in step S2, the welding voltage of the electrode and the lower electrode is 1.0-1.6V.

[0016] In some embodiments, in step S2, the welding current of the electrode and the lower electrode is 20,000-30,000 A.

[0017] In some embodiments, in step S2, the welding pressure of the electrode and the lower electrode is 0.1-0.5 MPa.

[0018] In some embodiments, in step S2, the welding speed of the electrode and the lower electrode is 10-150 mm / min.

[0019] The present invention also provides a surface tension tank using a method for connecting dissimilar metals in a mesh.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The process of this invention is simple. The connection between the aluminum alloy perforated plate and the stainless steel screen only requires one clamping and one welding to form the plate and screen assembly, which solves the problem that traditional titanium alloy perforated plates and stainless steel screens require multiple clamping and welding.

[0022] (2) The present invention has low cost, does not need to be carried out in a vacuum environment, requires fewer forming and welding steps between the aluminum alloy perforated plate and the stainless steel screen, has lower welding environment requirements, and has a lower unit price of aluminum alloy material.

[0023] (3) The present invention has a small mass and low density of aluminum alloy material, and the mass is even smaller under the premise of the same thickness of titanium alloy. Attached Figure Description

[0024] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of the connection method of the present invention.

[0026] Numbering on the map:

[0027] 1. Aluminum alloy perforated plate; 2. Stainless steel screen; 3. Upper electrode; 4. Lower electrode. Detailed Implementation

[0028] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0029] Example 1

[0030] According to the present invention, a method for connecting dissimilar metals in a mesh is provided, such as... Figure 1 As shown, the specific steps are as follows:

[0031] S1. Clamp multiple aluminum alloy perforated plates 1 and stainless steel screen 2 using tooling, so that the stainless steel screen 2 is assembled between the aluminum alloy perforated plates 1.

[0032] S2. The assembled workpiece is clamped between the upper electrode 3 and the lower electrode 4 on the roll welding machine. The non-hole part of the aluminum alloy in contact with the electrode is subjected to a voltage of 1.0-1.6V, a current of 20000-30000A, a pressure of 0.1-0.5MPa, and a welding speed of 10-150mm / min by the roll welding machine.

[0033] S3. The upper electrode 3 and the lower electrode 4 work together to simultaneously weld and form the workpiece in the circumferential or longitudinal direction.

[0034] More specifically, the aluminum alloy perforated plate 1 has a wall thickness of 0.2-3mm, and the number of aluminum alloy perforated plates 1 is 2-4. The aluminum alloy perforated plate 1 has holes inside, and the distance between the outermost hole and the edge is not less than 3mm.

[0035] Working principle:To avoid the difficulties in welding dissimilar metals caused by the large difference in melting points between stainless steel and aluminum alloy, multiple aluminum alloy perforated plates and stainless steel screens that need to be in direct contact with the stainless steel screen are clamped together at once to form a "sandwich" structure. This structure is then formed by roll welding in one go using a roll welding machine. During this process, under the appropriate voltage and current applied by the roll welding motor, the aluminum alloy plates between the upper and lower electrodes are completely fused together. In this process, the molten aluminum alloy passes through the screen, completely bonding the screen between the upper and lower perforated plates, thus achieving the connection between the aluminum alloy perforated plates and the stainless steel screen.

[0036] Example 2

[0037] The present invention also provides a surface tension tank, which uses the dissimilar metal connection method of plate mesh in Example 1.

[0038] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0039] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for connecting dissimilar metals in a plate mesh, characterized in that, The specific steps are as follows: S1. Clamp multiple aluminum alloy perforated plates (1) and stainless steel screens (2) using tooling; S2. The assembled workpiece is clamped between the upper electrode (3) and the lower electrode (4) on the roll welding machine; S3, The upper electrode (3) and the lower electrode (4) are welded together in the circumferential direction to form the shape; The wall thickness of the aluminum alloy perforated plate (1) is 0.2-3 mm; The aluminum alloy perforated plate (1) has holes inside, and the distance between the outermost holes and the edge is not less than 3mm; In step S2, the welding pressure of the electrode (3) and the lower electrode (4) is 0.1-0.5 MPa; The dissimilar metal mesh obtained by the connection method is used in a surface tension tank.

2. The method for connecting dissimilar metals in a mesh as described in claim 1, characterized in that, The number of the aluminum alloy perforated plate (1) is 2-4.

3. The method for connecting dissimilar metals in a mesh as described in claim 1, characterized in that, The stainless steel screen (2) is assembled between the aluminum alloy perforated plates (1).

4. The method for connecting dissimilar metals in a mesh as described in claim 1, characterized in that, In step S2, the welding voltage of the electrode (3) and the lower electrode (4) is 1.0-1.6V.

5. The method for connecting dissimilar metals in a mesh as described in claim 1, characterized in that, In step S2, the welding current of the electrode (3) and the lower electrode (4) is 20000-30000A.

6. The method for connecting dissimilar metals in a mesh as described in claim 1, characterized in that, In step S2, the welding speed of the electrode (3) and the lower electrode (4) is 10-150 mm / min.

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