Soldering tab, soldering tab manufacturing method, and heat exchanger

Abstract

This application provides a welding sheet, a method for manufacturing the welding sheet, and a heat exchanger. The welding sheet includes: an isolation layer comprising a first surface and a second surface; a brazing filler layer disposed on the first surface; and a zinc-containing layer disposed on the second surface. The corrosion resistance of the isolation layer is higher than that of the brazing filler layer. This application can improve the pitting or intergranular corrosion resistance of aluminum alloy heat exchangers, thereby enhancing their corrosion resistance.

Description

Technical Field

[0001] This application relates to the field of heat exchanger technology, and in particular to a welding sheet, a welding sheet manufacturing method, and a heat exchanger. Background Technology

[0002] Parallel flow heat exchangers are widely used in air conditioning, automotive, and microelectromechanical systems (MEMS) fields due to their high heat exchange efficiency and compact design. A parallel flow heat exchanger mainly consists of heat exchange tubes and fins. The heat exchange medium flows inside the heat exchange tubes, and the fins are welded to the outer surface of the heat exchange tubes to increase the heat exchange area. With increasing performance requirements, the materials, structure, and welding system of parallel flow heat exchangers are continuously being optimized and improved.

[0003] Aluminum alloy is a commonly used material for parallel flow heat exchangers. However, aluminum alloy heat exchangers are susceptible to corrosion during use, leading to leakage of the heat exchange medium within the heat exchange tubes. The main types of corrosion are pitting and intergranular corrosion. To meet practical application requirements, it is necessary to mitigate pitting and intergranular corrosion in aluminum alloy heat exchangers and improve their corrosion resistance. Summary of the Invention

[0004] This application provides a welding sheet, a method for manufacturing the welding sheet, and a heat exchanger to improve the corrosion resistance of aluminum alloy heat exchangers.

[0005] The first aspect of this application provides a solder pad, comprising:

[0006] An isolation layer, the isolation layer comprising a first surface and a second surface;

[0007] A solder layer is disposed on the first surface;

[0008] A zinc-containing layer is disposed on the second surface;

[0009] The corrosion resistance of the isolation layer is higher than that of the solder layer.

[0010] Optionally, the thermal conductivity of the insulating layer is higher than that of aluminum.

[0011] Optionally, the material of the isolation layer is metal or alloy, and the potential of the isolation layer is higher than that of the solder layer.

[0012] Optionally, the material of the isolation layer is C1100 copper, C1020 oxygen-free copper, or C1010 oxygen-free copper.

[0013] Optionally, the material of the solder layer is a 4-series aluminum alloy.

[0014] Optionally, the zinc content of the zinc-containing layer is 4 g / m2 to 12 g / m2.

[0015] Optionally, the thickness of the solder sheet is H, where 0.05mm < H ≤ 0.5mm.

[0016] Optionally, the thickness of the isolation layer is H1, where 0.04mm ≤ H1 ≤ 0.45mm.

[0017] Optionally, the thickness of the solder layer is H2, where 0.01mm ≤ H2 ≤ 0.4mm.

[0018] A second aspect of this application provides a method for manufacturing a solder pad, the method being used to manufacture the solder pad provided in this application, the method comprising the following steps:

[0019] Step S1: Prepare a composite sheet, wherein the composite sheet comprises a layered insulating material and a solder;

[0020] Step S2: Prepare a zinc-containing layer on the surface of the composite sheet to form a solder sheet, wherein the zinc-containing layer is disposed on the side of the insulating material opposite to the solder.

[0021] Optionally, step S1 includes:

[0022] Step S11: The insulating material is a sheet, and the solder is evenly applied to the first surface of the insulating material;

[0023] Step S12: The insulating material and the brazing filler metal are rolled and pressed to form a composite sheet.

[0024] Optionally, step S2 includes: spraying zinc onto the surface of the composite sheet at a zinc content of 4 g / m2 to 12 g / m2.

[0025] A third aspect of this application provides a heat exchanger comprising heat exchange tubes and fins, wherein the heat exchange tubes and the fins are brazed together using welding tabs provided in this application.

[0026] The technical solution provided in this application can achieve the following beneficial effects:

[0027] The solder sheet provided in this embodiment includes an isolation layer, a solder layer, and a zinc-containing layer. The isolation layer includes a first surface and a second surface, which are opposite to each other along the thickness direction of the isolation layer. The solder layer is disposed on the first surface, and the zinc-containing layer is disposed on the second surface. When this solder sheet is used to braze a first workpiece and a second workpiece, the solder layer melts and fills the space between the second workpiece and the isolation layer, achieving a connection between the second workpiece and the isolation layer. The second workpiece and the solder layer are directly exposed to the external environment. When the external ionic environment simultaneously connects the second workpiece and the solder layer, electrochemical corrosion will occur between them. The zinc-containing layer melts and diffuses towards the first workpiece and the isolation layer, achieving a connection between them. The isolation layer and the first workpiece surround the zinc-containing layer, preventing the zinc-containing layer with a lower potential from directly contacting the external environment, thus making it difficult for electrochemical corrosion to occur on the side where the first workpiece is located. The corrosion resistance of the isolation layer is higher than that of the solder layer, causing the solder layer to corrode preferentially over the isolation layer, ensuring that the isolation layer can perform a reliable isolation function.

[0028] When the first workpiece and the second workpiece are brazed together using this welding piece, the workpiece is corroded sequentially along the direction of the second workpiece, the isolation layer and the first workpiece, so that the second workpiece and the isolation layer play a protective role in sequence, ensuring that the workpiece as a whole can be corroded according to the expected potential design, effectively improving the overall corrosion resistance of the workpiece.

[0029] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the connection between a first workpiece and a second workpiece using a welding sheet, as provided in an embodiment of this application.

[0031] Figure 2 This is a schematic diagram of the structure of the solder sheet provided in the embodiments of this application;

[0032] Figure 3 A flowchart illustrating the solder sheet manufacturing method provided in this application embodiment.

[0033] Figure label:

[0034] 1-First workpiece;

[0035] 2-Second workpiece;

[0036] 3-Solder sheet;

[0037] 31 - Isolation layer;

[0038] 32-Solder filler layer;

[0039] 33 - Zinc-containing layer.

[0040] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0042] In the description of this application, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0043] In the description of this specification, it should be understood that the directional terms such as "upper" and "lower" used in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should also be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0044] like Figures 1-3 As shown in the illustration, this application provides a brazing tab 3 for brazing a first workpiece 1 and a second workpiece 2, both made of aluminum alloy. The first workpiece 1 has a higher potential, while the second workpiece 2 has a lower potential. The brazing tab 3 forms a welded structure between the first workpiece 1 and the second workpiece 2, connecting them to form a complete workpiece. The brazing tab 3 provided in this application has good brazing performance and low requirements for anti-corrosion processing, thus reducing the overall production cost of the workpiece. Furthermore, the workpiece formed by brazing using the brazing tab 3 provided in this application has strong corrosion resistance, effectively extending the overall service life of the workpiece.

[0045] In one embodiment, the entire workpiece is a heat exchanger. The first workpiece 1 is a heat exchange tube, and the second workpiece 2 is a fin. That is, the heat exchange tube and the fins are brazed together using welding tabs 3, thus forming the heat exchanger together. The wall thickness of the heat exchange tube is less than 1 mm or 0.4 mm to reduce the wall thickness and improve the heat exchange performance of the heat exchanger. The material of the heat exchange tube can be, for example, 1-series aluminum alloy, 2-series aluminum alloy, or 3-series aluminum alloy to improve the strength of the heat exchange tube and optimize the overall structure of the heat exchanger. The material of the fins can be, for example, 7-series aluminum alloy to reduce the fin potential, allowing the fins to act as sacrificial protection and improve the corrosion resistance of the heat exchanger.

[0046] The solder sheet 3 provided in this embodiment includes an isolation layer 31, a brazing filler layer 32, and a zinc-containing layer 33. The isolation layer 31 includes a first surface and a second surface, which are two opposing surfaces of the isolation layer 31 along its thickness direction. The brazing filler layer 32 is disposed on the first surface, and the zinc-containing layer 33 is disposed on the second surface. The corrosion resistance of the isolation layer 31 is higher than that of the brazing filler layer 32, meaning that the isolation layer 31 is less prone to corrosion than the brazing filler layer 32. When the solder sheet 3 is used to braze the first workpiece 1 and the second workpiece 2, the brazing filler layer 32 melts and fills the space between the second workpiece 2 and the isolation layer 31, thus connecting the second workpiece 2 and the isolation layer 31. The second workpiece 2 and the brazing filler layer 32 are directly exposed to the external environment. When the external ionic environment simultaneously connects the second workpiece 2 and the brazing filler layer 32, electrochemical corrosion will occur between the second workpiece 2 and the brazing filler layer 32. The zinc-containing layer 33 melts and diffuses simultaneously into the first workpiece 1 and the isolation layer 31, achieving a connection between the first workpiece 1 and the isolation layer 31. The isolation layer 31 and the first workpiece 1 surround the zinc-containing layer 33, preventing the zinc-containing layer 33 with its lower potential from directly contacting the external environment, thus making it difficult for electrochemical corrosion to occur on the side where the first workpiece 1 is located. Therefore, the second workpiece 2 can be ensured to play a sacrificial protection role, effectively improving the overall corrosion resistance of the workpiece. In addition, since the zinc-containing layer 33 quickly diffuses into the isolation layers 31 and the second workpiece 2 on both sides after melting during the brazing process, it can effectively prevent the zinc-containing layer 33 from boiling or spheroidizing after melting, which would lead to uneven diffusion of the zinc-containing layer 33 and reduce the difficulty of the preparation process of the zinc-containing layer 33.

[0047] This application also provides a method for manufacturing a solder sheet, which includes the following steps: Step S1, preparing a composite sheet, the composite sheet including a layered isolation material and a solder, wherein the isolation material ultimately forms the isolation layer 31 of the solder sheet 3, and the solder ultimately forms the solder layer 32 of the solder sheet 3; Step S2, preparing a zinc-containing layer 33 on the surface of the composite sheet to form the solder sheet 3 provided in this application embodiment, wherein the zinc-containing layer 33 is located on the side of the isolation material facing away from the solder. By first combining the thicker isolation layer 31 and the solder layer 32 to form a composite sheet, and then preparing the thinner zinc-containing layer 33, damage such as wear or falling off of the thinner zinc-containing layer 33 can be prevented, thereby ensuring that both the solder layer 32 and the zinc-containing layer 33 can uniformly and completely cover the surface of the isolation layer 31.

[0048] Further, step S1 includes: step S11, the isolation material is a sheet, and the solder is uniformly covered on the first surface of the isolation material. The solder can be any suitable form such as sheet, powder or paste; step S12, the isolation material and the solder are rolled and pressed to form a composite sheet to increase the density of the composite sheet, thereby improving the thermal conductivity of the solder sheet 3.

[0049] Further, step S2 includes: spraying zinc powder onto the surface of the composite sheet at a zinc content of 4 g / m² to 12 g / m². That is, zinc powder is sprayed onto the second surface of the isolation layer 31 to form a zinc layer. On the one hand, this ensures that the zinc-containing layer 33 contains virtually no other elements besides zinc, thereby maximizing the zinc content and providing reliable corrosion protection. On the other hand, the zinc spraying process is simple to operate, fast, and does not alter the structure or morphology of the isolation layer 31.

[0050] In the above embodiments, the isolation layer 31 can be made of a metal or alloy that is not easily corroded, or it can be made of a non-metallic material such as ceramic that will not corrode. The melting point of the isolation layer 31 should be higher than that of aluminum, and the isolation layer 31 should not melt during the brazing process.

[0051] Furthermore, the thermal conductivity of the isolation layer 31 is higher than that of aluminum to ensure efficient heat transfer between the second workpiece 2 and the first workpiece 1 and improve heat dissipation. For example, the material of the isolation layer 31 can be copper (Cu) and its alloys, gold (Au) and its alloys, silver (Ag) and its alloys, thermally conductive ceramics, etc.

[0052] In some embodiments, the material of the isolation layer 31 is a metal or alloy, such as copper (Cu) and its alloys, gold (Au) and its alloys, silver (Ag) and its alloys, etc. The potential of the isolation layer 31 is higher than that of the solder layer 32, so that the solder layer 32 provides sacrificial protection for the isolation layer 31, ensuring that the isolation layer 31 can perform a reliable isolation function. That is, when the first workpiece 1 and the second workpiece 2 are brazed together using this solder piece 3, the workpieces are corroded sequentially along the direction of the second workpiece 2, the isolation layer 31, and the first workpiece 1, so that the second workpiece 2 and the isolation layer 31 sequentially provide protection, ensuring that the workpiece as a whole can be corroded according to the expected potential design, effectively improving the overall corrosion resistance of the workpiece.

[0053] Specifically, when the material of the isolation layer 31 is metal or alloy, the workpiece as a whole includes three corrosion stages, and the order of the three corrosion stages is as follows: Stage 1, corrosion of the side where the second workpiece 2 is located, including corrosion of the second workpiece 2 and corrosion of the solder layer 32, the corrosion methods include electrochemical corrosion and conventional chemical corrosion, until the material on the side where the second workpiece 2 is located is completely removed; Stage 2, isolation layer 31 is corroded alone, the corrosion method is conventional chemical corrosion, until the isolation layer 31 is perforated, exposing the material on the side where the first workpiece 1 is located to the external environment; Stage 3, corrosion of the side where the first workpiece 1 is located.

[0054] In some embodiments, the material of the insulating layer 31 is C1100 copper, C1020 oxygen-free copper, or C1010 oxygen-free copper, which has good thermal conductivity, is widely available, and has a low material cost. Therefore, it can ensure the heat transfer efficiency between the second workpiece 2 and the first workpiece 1, reduce production costs, and also ensure high welding strength.

[0055] Furthermore, the material of the solder layer 32 includes silicon and aluminum. By reasonably setting the mass ratio of silicon and aluminum, the potential of the solder layer 32 can be higher than that of the second workpiece 2, while the potential of the isolation layer 31 is higher than that of the solder layer 32. This causes the potentials of the second workpiece 2, the solder layer 32, and the isolation layer 31 to increase sequentially, thereby ensuring that the second workpiece 2, the solder layer 32, and the isolation layer 31 are corroded uniformly in sequence. This allows each layer of material to fully exert its protective function and effectively improves the overall corrosion resistance of the workpiece.

[0056] Specifically, on the side where the second workpiece 2 is located (i.e., the first stage), corrosion is carried out in the following order: Stage 1.1: The second workpiece 2 and the solder layer 32 are exposed to the external environment. Electrochemical corrosion occurs between the second workpiece 2 and the solder layer 32. The second workpiece 2 with the lower potential corrodes and gradually falls off until the second workpiece 2 is completely removed; Stage 1.2: The solder layer 32 is exposed to the external environment. The solder layer 32 undergoes conventional chemical corrosion until the solder layer 32 forms a perforation, exposing the isolation layer 31 to the external environment; Stage 1.3: The solder layer 32 and the isolation layer 31 are exposed to the external environment. Electrochemical corrosion occurs between the solder layer 32 and the isolation layer 31. The solder layer 32 with the lower potential corrodes and gradually falls off until the solder layer 32 is completely removed.

[0057] Furthermore, the brazing filler layer 32 is made of 4-series aluminum alloy, such as 4343 aluminum alloy, 4043 aluminum alloy, or 4045 aluminum alloy. This results in high weld strength and good fluidity, thus ensuring reliable weld quality.

[0058] Furthermore, the zinc-containing layer 33 is made of zinc, giving it a lower potential. When the isolation layer 31 perforates due to conventional chemical corrosion and loses its isolation function, the zinc-containing layer 33 is exposed to the external environment. Since the potential of the zinc-containing layer 33 is lower than that of the isolation layer 31, it corrodes rapidly under electrochemical corrosion. This allows the zinc-containing layer 33 to act as a sacrificial shield for the first workpiece 1, thereby further improving the overall corrosion resistance of the workpiece. In addition, the diffusion of the zinc-containing layer 33 into the first workpiece 1 reduces the zinc content gradient from the outside to the inside of the surface, causing the potential of the first workpiece 1 to gradually increase from the outside to the inside. This ensures uniform corrosion of the first workpiece 1 from the outside to the inside according to the gradient, effectively preventing pitting or intergranular corrosion on the surface of the first workpiece 1 and improving its corrosion resistance.

[0059] Specifically, after the isolation layer 31 loses its isolation function, corrosion occurs on the side where the first workpiece 1 is located (i.e., the third stage) in the following order: in the third stage, the zinc-containing layer 33 near the isolation layer 31 gradually falls off under the action of electrochemical corrosion until the isolation layer 31 loses its connecting material and falls off; in the third stage, the zinc-containing layer 33 on the surface of the first workpiece 1 is detached by gradient corrosion from the outside to the inside.

[0060] Furthermore, the zinc content of the zinc layer 33 is 4 g / m2 to 12 g / m2, for example, the zinc content of the zinc layer 33 is 4 g / m2, 4.5 g / m2, 5 g / m2, 5.5 g / m2, 6 g / m2, 6.5 g / m2, 7 g / m2, 7.5 g / m2, 8 g / m2, 8.5 g / m2, 9 g / m2, 9.5 g / m2, 10 g / m2, 10.5 g / m2, 11 g / m2, 11.5 g / m2 or 12 g / m2, etc., to ensure that uniform and slow corrosion is formed on the surface of the first workpiece 1. When the zinc content of the zinc layer 33 is less than 4 g / m2, the diffusion depth of zinc on the surface of the first workpiece 1 is small, and it is difficult to form a uniform diffusion gradient. As a result, the first workpiece 1 is difficult to form a uniform gradient corrosion as expected. Therefore, the first workpiece 1 may still experience pitting corrosion or intergranular corrosion. When the zinc content of the zinc layer 33 is higher than 12 g / m2, the zinc content is too high, which leads to an accelerated corrosion rate on the surface of the first workpiece 1, thereby affecting the corrosion resistance of the first workpiece 1.

[0061] Furthermore, the thickness of the welding piece 3 is H, where 0.05mm < H ≤ 0.5mm. For example, H can be 0.051mm, 0.052mm, 0.053mm, 0.055mm, 0.06mm, 0.07mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm, etc., which ensures both reliable welding strength and high heat dissipation effect. When H ≤ 0.05mm, the material of the welded structure formed by the welding piece 3 is too small, making it difficult to guarantee the welding strength of the workpiece; when H > 0.5mm, the thickness of the welded structure formed by the welding piece 3 is too large, resulting in a longer heat transfer path between the second workpiece 2 and the first workpiece 1, thus affecting the heat dissipation effect.

[0062] Furthermore, the thickness of the isolation layer 31 is H1, the thickness of the solder layer 32 is H2, and the thickness of the zinc-containing layer 33 is H3. H1 > H2 > H3, meaning that the thicknesses of the isolation layer 31, solder layer 32, and zinc-containing layer 33 decrease sequentially. The isolation layer 31 has the largest thickness, ensuring that the welded structure formed by the solder sheet 3 has excellent thermal conductivity. H3 is approximately 0.002 mm, and the zinc-containing layer 33 has the smallest thickness, ensuring that the isolation layer 31 and the first workpiece 1 reliably surround the zinc-containing layer 33, preventing the material of the zinc-containing layer 33 from being exposed to the external environment, which would prevent corrosion from occurring in the expected order (i.e., the zinc-containing layer 33 has the lowest potential, and electrochemical corrosion occurs prematurely on the side where the first workpiece 1 is located), thus affecting the overall corrosion resistance of the workpiece.

[0063] Furthermore, the thickness H1 of the isolation layer 31 is within the following range: 0.04mm ≤ H1 ≤ 0.45mm. For example, H1 can be 0.04mm, 0.05mm, 0.07mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, or 0.45mm, etc., which can provide reliable isolation while meeting the heat transfer requirements between the second workpiece 2 and the first workpiece 1. When H1 < 0.04mm, the thickness of the isolation layer 31 is too thin, which may cause the zinc layer 33 to be exposed during brazing, preventing it from being corroded in the expected order; when H1 > 0.45mm, the thickness of the isolation layer 31 is too thick, resulting in a longer heat transfer path between the second workpiece 2 and the first workpiece 1, affecting heat dissipation and leading to material waste.

[0064] Furthermore, the density of the isolation layer 31 is 8.89 g / m³ to 8.93 g / m³, for example, it can be 8.89 g / m³, 8.90 g / m³, 8.91 g / m³, 8.92 g / m³, or 8.93 g / m³, to improve the thermal conductivity of the solder pad 3. When the density of the isolation layer 31 is less than 8.89 g / m³, the isolation layer 31 has more voids, resulting in poor thermal conductivity; when the density of the isolation layer 31 is greater than 8.93 g / m³, the production cost is too high.

[0065] Furthermore, the thickness H2 of the solder layer 32 is within the following range: 0.01mm ≤ H2 ≤ 0.4mm. For example, H2 can be 0.01mm, 0.02mm, 0.05mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, or 0.4mm, etc., which can ensure reliable welding quality and meet the heat transfer requirements between the second workpiece 2 and the first workpiece 1. When H2 < 0.01mm, the material of the solder layer 32 is too small, which is prone to welding defects; when H2 > 0.4mm, the thickness of the solder layer 32 is too large, and due to the low thermal conductivity of the solder layer 32, the heat dissipation effect is affected.

[0066] Furthermore, the density of the solder layer 32 is 2.66 g / m³ to 2.71 g / m³, for example, it can be 2.66 g / m³, 2.67 g / m³, 2.68 g / m³, 2.69 g / m³, 2.70 g / m³, or 2.71 g / m³, to improve the thermal conductivity of the solder sheet 3. When the density of the solder layer 32 is less than 2.66 g / m³, there are more voids in the solder layer 32, resulting in poor thermal conductivity; when the density of the solder layer 32 is greater than 2.71 g / m³, the production cost is too high.

[0067] A specific structure and manufacturing method of the solder sheet 3 provided in this application embodiment can be referred to as follows: The isolation material is a sheet with a thickness of 0.5mm to 3mm, and the material is C1010 oxygen-free copper; the brazing filler metal is a sheet with a thickness of 0.3mm to 0.5mm, and the material is 4343 aluminum alloy; the brazing filler metal is bonded to the first surface of the isolation material to form a composite sheet, and the composite sheet is rolled to make the thickness of the composite sheet <0.25mm; zinc is sprayed on the second surface of the isolation layer 31 with a zinc content of 5g / m2 to 11g / m2 to form the solder sheet 3.

[0068] To illustrate the welding performance and corrosion resistance of the welding sheet 3 provided in the embodiments of this application, a comparative experiment is conducted between the heat exchanger prepared by the welding sheet 3 provided in the embodiments of this application and an existing heat exchanger. The experimental results are detailed in Table 1.

[0069] Each sample number represents a group of identical heat exchangers. Except for the brazing material, all other parameters (e.g., heat exchanger tube material and thickness, fin material and thickness, etc.) of the heat exchangers in each group are exactly the same, and the experimental conditions are also exactly the same.

[0070] It should be noted that the specific structures of the heat exchangers in the embodiments and comparative examples in Table 1 are as follows:

[0071] Example 1

[0072] The insulating material is a 3mm thick sheet made of C1010 oxygen-free copper; the brazing filler metal is a 1mm thick sheet made of 4343 aluminum alloy; the brazing filler metal is bonded to the first surface of the insulating material to form a composite sheet, and the composite sheet is rolled to make the thickness of the composite sheet <0.45mm; the second surface of the insulating material is sprayed with zinc at a zinc content of 11g / m2 to form a weld sheet 3.

[0073] The heat exchange tubes are made of 3003 aluminum alloy, and the fins are made of 7072 aluminum alloy. The heat exchange tubes and fins are brazed together by welding tabs 3 to form a heat exchanger.

[0074] Example 2

[0075] The insulating material is a 0.5mm thick sheet made of C1100 copper; the brazing filler metal is a 0.5mm thick sheet made of 4045 aluminum alloy; the brazing filler metal is bonded to the first surface of the insulating material to form a composite sheet, and the composite sheet is rolled to make the thickness of the composite sheet <0.08mm; the second surface of the insulating material is sprayed with zinc at a zinc content of 10g / m2 to form a weld sheet 3.

[0076] The heat exchange tubes are made of 3003 aluminum alloy, and the fins are made of 7072 aluminum alloy. The heat exchange tubes and fins are brazed together by welding tabs 3 to form a heat exchanger.

[0077] Example 3

[0078] The insulating material is a 0.5mm thick sheet made of C1100 copper; the brazing filler metal is a 0.3mm thick sheet made of 4004 aluminum alloy; the brazing filler metal is bonded to the first surface of the insulating material to form a composite sheet, and the composite sheet is rolled to make the thickness of the composite sheet <0.1mm; the second surface of the insulating material is sprayed with zinc at a zinc content of 5.5g / m2 to form a weld sheet 3.

[0079] The heat exchange tubes are made of 3003 aluminum alloy, and the fins are made of 7072 aluminum alloy. The heat exchange tubes and fins are brazed together by welding tabs 3 to form a heat exchanger.

[0080] Example 4

[0081] The insulating material is a 1.5mm thick sheet made of C1100 copper; the brazing filler metal is a 0.5mm thick sheet made of 4045 aluminum alloy; the brazing filler metal is bonded to the first surface of the insulating material to form a composite sheet, and the composite sheet is rolled to make the thickness of the composite sheet <0.2mm; the second surface of the insulating material is sprayed with zinc at a zinc content of 5g / m2 to form a weld sheet 3.

[0082] The heat exchange tubes are made of 3003 aluminum alloy, and the fins are made of 7072 aluminum alloy. The heat exchange tubes and fins are brazed together by welding tabs 3 to form a heat exchanger.

[0083] Example 5

[0084] The insulating material is a 1.5mm thick sheet made of C1100 copper; the brazing filler metal is a 0.5mm thick sheet made of 4043 aluminum alloy; the brazing filler metal is bonded to the first surface of the insulating material to form a composite sheet, and the composite sheet is rolled to make the thickness of the composite sheet <0.25mm; the second surface of the insulating material is sprayed with zinc at a zinc content of 8.5g / m2 to form a weld sheet 3.

[0085] The heat exchange tubes are made of 3003 aluminum alloy, and the fins are made of 7072 aluminum alloy. The heat exchange tubes and fins are brazed together by welding tabs 3 to form a heat exchanger.

[0086] Comparative Example

[0087] The heat exchange tubes are made of 3003 aluminum alloy, and the surface of the heat exchange tubes is treated with zinc spraying at 8g / m2; the fins are made of 7072 aluminum alloy, and the surface of the fins is composited with 4343 aluminum alloy; the heat exchange tubes and fins are directly brazed to form a heat exchanger.

[0088] Table 1

[0089]

[0090]

[0091] According to the experimental results in Table 1, the heat exchanger prepared using the welding strips provided in this application embodiment has better welding quality and superior corrosion resistance compared to existing heat exchangers. Although the heat exchange performance is slightly reduced, it still meets the heat exchange requirements of the heat exchanger. Specifically, the brazed joint forming performance and erosion resistance of heat exchangers 1# to 5# are better than those of heat exchanger 6#, indicating higher welding quality. Under the same experimental environment and after the same duration, when heat exchanger 6# leaked, heat exchangers 1# to 5# did not leak. Therefore, the heat exchanger prepared using the welding strips provided in this application embodiment can improve the corrosion resistance of the heat exchanger and extend its service life.

[0092] Furthermore, #1, #4, and #5 only experienced stage 1 corrosion throughout the entire experimental cycle, and the corrosion occurred on the fins. #2 only experienced stage 1 corrosion throughout the entire experimental cycle, and the corrosion occurred sequentially on the fins and the brazing filler layer. #3 experienced stage 1, stage 2, and stage 3 corrosion throughout the entire experimental cycle, meaning that both the fins and the brazing filler layer were completely corroded, the isolation layer was perforated, and corrosion of the zinc-containing layer led to the detachment of the isolation layer. Therefore, it can be seen that the heat exchanger prepared with the soldered sheet provided in this application embodiment can undergo stage 1, stage 2, and stage 3 corrosion in the designed sequence, allowing the fins and isolation layer to fully exert their sacrificial protection function, thus effectively improving the corrosion resistance of the heat exchanger.

[0093] In addition, the heat exchanger made of the welding sheet provided in this application embodiment has an additional second-stage corrosion (i.e., isolation layer corrosion) that is not present in existing heat exchangers; the added second-stage corrosion separates the original first-stage corrosion and third-stage corrosion from each other, thereby strictly limiting the corrosion sequence of each layer of material and forming effective protection for the heat exchange tube.

[0094] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A soldering tab, characterized by include: An isolation layer, the isolation layer comprising a first surface and a second surface; A solder layer is disposed on the first surface; A zinc-containing layer is disposed on the second surface; The corrosion resistance of the isolation layer is higher than that of the solder layer.

2. The soldering tab of claim 1, wherein, The thermal conductivity of the insulating layer is higher than that of aluminum.

3. The soldering tab of claim 1, wherein, The isolation layer is made of metal or alloy, and the potential of the isolation layer is higher than that of the solder layer.

4. The soldering tab of claim 1, wherein, The material of the isolation layer is C1100 copper, C1020 oxygen-free copper, or C1010 oxygen-free copper.

5. The soldering tab of claim 1, wherein, The material of the solder layer is 4-series aluminum alloy.

6. The soldering tab of claim 1, wherein, The zinc content of the zinc-containing layer is 4 g / m2 to 12 g / m2.

7. The soldering lug according to any one of claims 1 to 6, characterized in that The thickness of the welding sheet is H, where 0.05mm < H ≤ 0.5mm.

8. The soldering tab according to any one of claims 1-6, characterized in that The thickness of the isolation layer is H1, where 0.04mm ≤ H1 ≤ 0.45mm.

9. The soldering tab according to any one of claims 1-6, characterized in that, The thickness of the solder layer is H2, where 0.01mm ≤ H2 ≤ 0.4mm.

10. A method of manufacturing a soldering tab, characterized by, The method for manufacturing a solder sheet is used to manufacture the solder sheet according to any one of claims 1-9, and the method for manufacturing a solder sheet includes the following steps: Step S1: Prepare a composite sheet, wherein the composite sheet comprises a layered insulating material and a solder; Step S2: Prepare a zinc-containing layer on the surface of the composite sheet to form a solder sheet, wherein the zinc-containing layer is disposed on the side of the insulating material opposite to the solder.

11. The method of claim 10, wherein Step S1 includes: Step S11: The insulating material is a sheet, and the solder is evenly applied to the first surface of the insulating material; Step S12: The insulating material and the brazing filler metal are rolled and pressed to form a composite sheet.

12. The method of claim 11, wherein Step S2 includes: spraying zinc onto the surface of the composite sheet at a zinc content of 4g / m2 to 12g / m2.

13. A heat exchanger, characterized by It includes a heat exchange tube and fins, wherein the heat exchange tube and the fins are brazed together using the welding plates described in any one of claims 1-9.

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