Embedded metal tube structure and brazing method

Abstract

The application discloses an embedded metal pipe structure and a brazing method, and relates to the technical field of brazing.The method comprises the following steps: embedding grooves are formed on the surface of a base; a support with a mesh hole is placed at the bottom of the embedding groove; a metal pipe to be brazed is placed in the embedding groove; an elastic top rod is used to apply pressure to the metal pipe; solid solder is placed on the top of the metal pipe; a heating device is used to apply high-temperature heating to the metal pipe and the base, so that the solid solder is melted to become liquid solder to fill the embedding groove; and pressure is applied to the surface of the metal pipe and ultrasonic vibration is applied to the surface of the metal pipe. The metal pipe is supported by the support, so that the metal pipe is spaced from the bottom of the embedding groove; when the solid solder is melted into liquid solder, the liquid solder can contact the bottom of the metal pipe; the metal pipe is limited by the elastic top rod, so that the metal pipe is prevented from floating up during brazing and the ultrasonic vibration is not affected on the propagation on the surface of the metal pipe; the brazing seam is filled fully; and the interface bonding strength is high.

Description

Technical Field

[0001] This invention relates to the field of brazing technology, specifically to an embedded metal tube structure and brazing method. Background Technology

[0002] Embedded metal tube structures are a common structural form in heat exchange systems, especially in structures with high requirements for tooling precision and heat exchange performance. Brazing is typically used to improve the heat exchange efficiency between the metal tube and the substrate. Specifically, solder is applied between the embedding groove and the metal tube. The molten solder, after being heated, fills the assembly gap between the embedding groove and the metal tube, causing a metallurgical reaction at the interface, thereby improving the interfacial bonding strength. High thermal conductivity alloy solders can further enhance the heat exchange efficiency between the substrate and the metal tube.

[0003] However, during the brazing process, the metal tube is placed directly at the bottom of the inlay groove. Under the buoyancy of the liquid solder, the metal tube will float out of the inlay groove, which will apply a rigid constraint to the metal tube so that it contacts the bottom of the groove. The bottom of the metal tube cannot contact the liquid solder, resulting in incomplete filling of the brazing seam and low interface bonding strength. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an embedded metal tube structure and brazing method to solve the technical problem in the prior art where, during the brazing process, the metal tube is directly placed at the bottom of the embedding groove and floats out of the embedding groove. Applying rigid constraints to make the metal tube contact the bottom of the groove prevents the bottom of the metal tube from contacting the liquid solder, resulting in incomplete brazing fill and low interface bonding strength.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an embedded metal tube structure, comprising: The substrate has an inlay groove. A support member is disposed at the bottom of the inlay groove, and the support member has a mesh. Metal tube, located on the support member; and Solder is used to fill the inlay groove and the mesh, and the solder covers all parts of the outside of the metal tube.

[0006] In some embodiments, the support is a one-dimensional metal wire, a two-dimensional metal woven mesh, or a three-dimensional metal foam, and the thickness of the support is 0.05-1mm.

[0007] Secondly, the present invention also provides a brazing method for an embedded metal tube structure, the brazing method being used to manufacture the aforementioned embedded metal tube structure, the brazing method comprising the following steps: An inlay groove is created on the substrate surface; A support with mesh is placed at the bottom of the inlay groove; Place the metal tube to be brazed into the mounting groove; A flexible push rod is used to apply pressure to both ends of the metal tube; Solid solder is placed on top of a metal tube. A heating device is used to heat the metal tube and the substrate to melt the solid solder, so that the solid solder becomes liquid solder and fills the insert groove. Pressure is applied to the surface of the metal tube and ultrasonic vibration is activated.

[0008] In some embodiments, the following steps are also included: After the support is placed in the mounting groove, an alloy solder sheet is laid on the support and bent to form a slot. Then, the metal tube is inserted into the slot for fixation.

[0009] In some embodiments, an alloy solder sheet is placed into the inlay groove, the alloy solder sheet being positioned above or below the support member, or the alloy solder sheet is first combined with the support member to form a composite solder sheet, and then the composite solder sheet is placed in the inlay groove.

[0010] In some embodiments, the pressure applied by the elastic push rod to the end of the metal tube can be adjusted in real time, with an adjustment range of 0-100MPa and an action distance of 50-1000mm.

[0011] In some embodiments, the vibrating head of an ultrasonic vibration device applies ultrasonic vibrations at intervals along the beginning and end of a metal tube.

[0012] In some embodiments, the ultrasonic vibration device has a vibration frequency of 18-40kHz, an amplitude of 8-60μm, applies a pressure of 0.1-5MPa to the metal tube, and has an ultrasonic vibration time of 10-300s. The ultrasonic loading direction includes, but is not limited to, being perpendicular to or parallel to the surface of the metal tube.

[0013] In some embodiments, the ultrasonic vibration device applies a vibration interval of 5-100 mm to the metal tube, or a vibrating head with continuous vibration acts on the surface of the metal tube and moves at a constant speed along the axial direction of the metal tube.

[0014] In some embodiments, the moving speed of the vibrating head is 0.2-2 mm / s.

[0015] In some embodiments, the following steps are also included: Use a scraper or steel brush to scrape the upper surface of the metal tube and the side wall of the mounting groove above the metal tube, and use a tool to vertically tap the surface of the metal tube until no impurities float to the surface of the liquid alloy solder, and keep the alloy solder in the brazing seam in a liquid phase state for a period of time.

[0016] In some embodiments, the following steps are also included: A two-dimensional metal mesh is laid on top of the metal tube, heating is stopped, and the liquid solder is allowed to completely solidify, forming a structure in which the metal tube is embedded in the groove.

[0017] Compared with the prior art, the embedded metal tube structure provided by the present invention places a support member with mesh at the bottom of the embedding groove, with the metal tube on top of the support member. The support member pads the metal tube so that the metal tube is separated from the bottom of the embedding groove and does not contact the bottom of the groove. When the solid solder is heated and melted into liquid solder, the liquid solder can contact the bottom of the metal tube. An elastic push rod is used to apply pressure to the metal tube to prevent the metal tube from floating during the brazing process, while not affecting the propagation of ultrasonic vibration on the surface of the metal tube. A two-dimensional metal mesh is laid on top of the metal tube, which can increase the strength of the solder layer on the metal tube and control the thermal expansion coefficient of the solder layer. After the liquid solder solidifies, it can completely cover the metal tube, resulting in full filling of the brazing seam and high interface bonding strength. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the embedded metal tube structure provided in an embodiment of the present invention; Figure 2 yes Figure 1 An enlarged schematic diagram of part A in the middle; Figure 3 This is a schematic diagram of the structure of a solid solder being heated and melted into a liquid solder according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a solid solder when heated and melted into a liquid solder according to another embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a metal tube brazed in an inlay groove according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the solid solder when it is completely melted according to an embodiment of the present invention; Figure 7 This is a schematic flowchart of the brazing method for embedded metal tubes provided in an embodiment of the present invention; Detailed Implementation To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] To address the technical problem in existing technologies where the metal tube directly contacts the bottom of the brazing tank during the brazing process, resulting in the bottom of the metal tube failing to make contact with the liquid solder, leading to incomplete brazing seam filling and low interface bonding strength, this invention provides an embedded metal tube structure that enables full contact between the liquid solder and the metal tube, resulting in full brazing seam filling and high interface bonding strength.

[0020] Please see Figures 1 to 4 , Figure 1 This is a schematic diagram of a brazing method for an embedded metal tube structure according to an embodiment of the present invention. The embedded metal tube structure includes a substrate 1, a support 3, a metal tube 2, and solder 6. The substrate 1 has an inlay groove 11; the support 3 is located at the bottom of the inlay groove 11 and has mesh; the metal tube 2 is located on the support 3; the solder 6 fills the inlay groove 11 and the mesh, and the solder 6 covers all parts of the outer side of the metal tube 2. In this embodiment, the metal tube 2 is located on top of the support 3, and the support 3 supports the metal tube 2 so that the metal tube 2 is spaced from the bottom of the inlay groove 11 and does not contact the bottom of the groove. When the solid solder is heated and melted into liquid solder, the liquid solder can contact the bottom of the metal tube 2. After the liquid solder solidifies, it can completely cover the metal tube 2, resulting in a full brazing seam and high interface bonding strength.

[0021] In some embodiments, the support 3 is a one-dimensional metal wire, a two-dimensional metal woven mesh, or a three-dimensional metal foam, and the thickness of the support 3 is 0.2-2 mm. In this embodiment, the support 3 is preferably a two-dimensional metal woven mesh, and the thickness of the woven mesh can be 0.2-2 mm. The woven mesh has a large number of mesh openings, which is conducive to the rapid penetration of liquid solder.

[0022] Secondly, please refer to Figures 5 to 7 The present invention also provides a brazing method for an embedded metal tube structure, the brazing method being used to manufacture the aforementioned embedded metal tube structure, the brazing method comprising the following steps: (a) An inlay groove 11 is formed on the surface of the substrate 1; According to the design requirements, an inlay groove 11 for embedding the metal tube 2 is machined at a designated location on the substrate 1. The cross-sectional profile of the inlay groove 11 and the outer cross-sectional profile of the metal tube 2 can be U-shaped, circular, rectangular, elliptical, irregular, or spiral. The dimensions of the inlay groove 11 are slightly larger than the outer diameter of the metal tube 2 to ensure that the metal tube 2 can be placed inside the inlay groove 11. The substrate can be made of stainless steel, with dimensions of 400mm × 40mm × 30mm (length × width × height), and the inlay groove 11 has dimensions of 400mm × 10mm × 10mm (length × width × height). The metal tube 2 can be a stainless steel tube with an outer diameter of 9mm, an inner diameter of 7mm, and a length of 400mm. Before placing the metal tube 2 into the inlay groove 11, the walls of the inlay groove 11 and the outer wall of the metal tube 2 are sanded with 180-grit sandpaper. Then, the walls of the inlay groove 11 and the outer wall of the metal tube 2 are wiped clean with lint-free paper soaked in anhydrous ethanol and allowed to air dry to remove surface impurities as much as possible and avoid impurities affecting the interfacial bonding strength of the metal tube 2.

[0023] (ii) Place a support member 3 with mesh holes at the bottom of the inlay groove 11; Select a suitable material and specification for the support component 3. For example, the support component 3 can be made of one-dimensional metal wire or two-dimensional metal braided mesh. The thickness of the braided mesh can be 0.2-2mm, and the numerous mesh openings facilitate the rapid penetration of liquid solder. The material of the support component 3 can be nickel, copper, titanium, aluminum, iron, or metal alloy composite materials, which have high thermal conductivity. Place the support component 3 flat on the bottom of the mounting groove 11, ensuring that the support component 3 can evenly support the metal tube 2, maintaining a certain distance between the metal tube 2 and the bottom of the mounting groove 11 to avoid direct contact between the metal tube 2 and the bottom of the mounting groove 11. A fixed gap and fully filled brazing seam can achieve uniform and efficient heat exchange performance of the heat exchange structure, and the high thermal conductivity of the support component 3 can further improve the heat exchange performance of the structure. In addition, the support member 3 is laid between the metal tube 2 and the wall of the inlay groove 11, which can effectively control the thermal mismatch between the brazing seam and the metal tube 2 and the wall of the inlay groove 11, improve the structure's resistance to temperature shock, and provide good conditions for the generation of ultrasonic cavitation effect, thereby promoting the metallurgical reaction at the brazing seam interface and significantly improving the interface bonding performance.

[0024] (iii) Place the metal tube 2 to be brazed into the mounting groove 11; Please see Figure 1 The pre-treated metal tube 2 to be brazed is placed on the support 3 that has been laid in the inlay groove 11. Ensure that the position of the metal tube 2 in the groove 11 is accurate and that it is in full contact with the support 3. At the same time, prevent the metal tube 2 from damaging or deforming the support 3 during placement.

[0025] (iv) Apply pressure to the metal tube 2 using the elastic push rod 9: Please see Figure 5 and Figure 6 The elastic push rod 8 is pressed onto the surface of the metal tube 2. The arrangement spacing, cross-sectional area and pressure of the elastic push rod 9 should be reasonably determined according to the size of the metal tube 2 to ensure that the metal tube 2 can be effectively confined during the brazing process and will not affect the propagation of ultrasonic vibration on the surface of the metal tube 2.

[0026] (iv) Place solid solder 4 on top of metal tube 3, use a heating device to heat metal tube 2 and substrate 1 at high temperature to melt solid solder 4 so that solid solder 4 becomes liquid solder to fill the inlay groove 11. Please see Figure 5 and Figure 6 According to the welding requirements, select a suitable solid solder 4 and place it on top of the metal tube 2. The amount of solid solder 4 should be reasonably determined according to the size of the insert groove 11 and the specifications of the metal tube 2 to ensure that it can fully fill the insert groove 11 after heating and melting and that the liquid solder will not overflow the insert groove 11.

[0027] Connect the heating device to the metal tube 2 and the substrate 1, and set the heating temperature to be 20℃-150℃ higher than the melting point of the solid solder 4, but lower than the melting points of the substrate 1 and the metal tube 2. Turn on the heating device to uniformly heat the metal tube 2 and the substrate 1, so that the solid solder 4 gradually melts into liquid solder and fills the embedding groove 11.

[0028] (v) Apply pressure to the surface of metal tube 2 and turn on ultrasonic vibration; Please see Figure 5 During the heating process, the vibrating head 51 of the ultrasonic vibration device 5 is aligned with the surface of the metal tube, and appropriate pressure is applied to ensure close contact between the vibrating head 51 and the surface of the metal tube 2. The vibration frequency of the ultrasonic vibration device 5 can be set to 18-40kHz, the amplitude can be controlled to 8-60μm, the pressure applied to the metal tube 2 can range from 0.1-5MPa, and the ultrasonic vibration time is determined according to the actual situation, usually 10-300s. The ultrasonic loading direction can be perpendicular or parallel to the surface of the metal tube 2, etc.

[0029] The ultrasonic vibration device 5 is activated, causing the metal tube 2 to vibrate slightly under the action of ultrasonic vibration, which promotes the liquid solder to better fill the inlay groove 11 and enhances the bonding force between the liquid solder and the metal tube 2 and the substrate 1.

[0030] In one embodiment, please refer to Figure 1 and Figure 2 It also includes the following steps: After placing the support 3 in the mounting groove 11, an alloy solder sheet 8 is laid on the support 3, and the alloy solder sheet 8 is bent to form a groove. The metal tube 2 is then inserted into the groove for fixation. The material and specifications of the alloy solder sheet 8 should match the substrate and the metal tube 2. Its function is to provide an additional source of solder during brazing and to enhance the bonding strength between the metal tube 2 and the substrate 1. By bending the alloy solder sheet 8 to form a groove, the position of the metal tube 2 can be effectively fixed, preventing the metal tube 2 from shifting or shaking during brazing, thus ensuring the stability of the welding process and the reliability of the welding quality.

[0031] In one embodiment, the following steps are also included: An alloy solder sheet 8 is inserted into the mounting groove 11, and the alloy solder sheet 8 is positioned above or below the support member 3, for example... Figure 2 In the embodiment shown, the alloy solder sheet 8 is placed above the support member 3. In other embodiments, the alloy solder sheet 8 can also be placed below the support member 3 and in contact with the groove wall of the inlay groove 11. When the alloy solder sheet 8 is heated and melted, it can fill the bottom of the metal tube 2.

[0032] In another embodiment, the alloy solder sheet 8 and the support member 3 can be combined outside the inlay groove 11 to form a composite solder sheet, and then the composite solder sheet can be placed in the inlay groove 11. The advantage of this method is that the alloy solder sheet 8 and the support member 3 are connected in advance and can remain relatively fixed after being placed in the inlay groove 11. After the alloy solder sheet 8 melts, it can effectively fill the bottom of the substrate 1.

[0033] In one embodiment, please refer to Figure 5 The vibrating head 51 is used to apply ultrasonic vibration at intervals along the metal tube 2 from the beginning to the end. After the ultrasonic vibration ends, the alloy solder in the brazing seam is kept in liquid phase for a period of time.

[0034] In one embodiment, the ultrasonic vibration device 5 has a vibration frequency of 18-40 kHz, an amplitude of 8-60 μm, applies a pressure of 0.1-5 MPa to the metal tube, and has an ultrasonic vibration time of 10-300 s. The ultrasonic loading direction includes, but is not limited to, being perpendicular to or parallel to the surface of the metal tube. Ultrasonic-assisted brazing can achieve metallurgical bonding between materials with poor surface wetting properties, and can promote the interfacial metallurgical reaction between the liquid phase solder and the metal tube 2 and the wall of the embedding groove 11, thereby improving the interfacial bonding strength and enhancing the load-bearing capacity of the structure.

[0035] In one embodiment, please refer to Figure 5 and Figure 6The ultrasonic vibration device 5 applies a vibration interval of 5-100mm to the metal tube 2, or a continuously vibrating vibrating head 51 acts on the surface of the metal tube 2 and moves at a uniform speed along the axis of the metal tube 2. The ultrasonic vibration device 5 applies a vibration interval of 5-100mm to the metal tube 2 to ensure that the ultrasonic vibration can uniformly cover the entire surface of the metal tube 2, so that the liquid solder can receive sufficient vibration assistance in all parts of the metal tube 2, thereby improving the welding quality of the entire brazing area. Alternatively, a continuously vibrating vibrating head 51 acts on the surface of the metal tube 2 and moves at a uniform speed along the axis of the metal tube 2. This method allows the metal tube 2 to be continuously subjected to ultrasonic vibration during the brazing process, which is beneficial to the filling and bonding of the solder. At the same time, the uniformly moving vibrating head ensures the uniformity and consistency of the ultrasonic vibration, further improving the welding effect. The moving speed of the vibrating head 51 can be set to 0.2-2mm / second. Extensive testing has shown that setting the moving speed of the vibrating head 51 to 0.2-2mm / second results in very good solder filling and bonding.

[0036] In one embodiment, please refer to Figure 3 It also includes the following steps: Use a scraper 7 or a steel brush to scrape the upper surface of the metal tube 2 and the side wall of the mounting groove above the metal tube 2: Before the liquid solder has completely solidified, use the scraper 7 to carefully scrape the side wall of the mounting groove 11 above the metal tube 2. This can remove the oxide film on the wall of the mounting groove 11, further promote the metallurgical reaction between the liquid solder and the wall, and improve the interfacial bonding strength.

[0037] Use a tool to vertically tap the surface of the metal tube: This vertical tapping causes impurities on the surface of the metal tube to float to the surface of the liquid alloy solder, further improving the purity and quality of the weld joint. Continue tapping until no impurities float to the surface of the liquid alloy solder.

[0038] Maintaining the alloy solder in the brazing seam in a liquid phase state for a period of time ensures that the liquid solder can fully fill and diffuse before solidification, thereby further improving the welding quality.

[0039] In one embodiment, please refer to Figure 4 It also includes the following steps: A two-dimensional metal mesh 10 is laid on top of the metal tube 2. The material of the metal mesh can be nickel, copper, titanium, aluminum, iron or metal alloy composite material. The metal mesh can increase the strength of the solder layer above the metal tube 2 and control the thermal expansion coefficient of the solder layer.

[0040] Stop heating and wait for the liquid solder to solidify completely: After confirming that the impurities in the liquid solder have been basically removed, stop heating and allow the liquid solder to solidify gradually under natural or controlled cooling conditions, eventually forming a solid structure in which the metal tube 2 is embedded in the inlay groove 11, thus completing the entire brazing process.

[0041] To better understand this invention, the following is combined with... Figures 1 to 7 The technical solution of the present invention will be described in detail below: The brazing method for the embedded metal tube 2 of this invention cleverly places a support member 3 with mesh at the bottom of the embedding groove 11, maintaining a gap between the metal tube 2 and the bottom of the embedding groove 11. This ensures that the solid solder can fully contact the bottom of the metal tube 2 after heating and melting. An elastic push rod 9 is used to limit the metal tube 2, preventing it from floating during welding and ensuring that the ultrasonic vibration propagation on the surface of the metal tube is not affected. This achieves full filling of the brazing seam and significantly improves the interface bonding strength. Furthermore, the application of ultrasonic vibration technology further optimizes the filling and bonding effect of the solder, effectively solving problems such as insufficient brazing seam filling and low bonding strength in traditional brazing methods. In addition, this invention also has the following advantages: 1) After the liquid phase solder enters the bottom of the metal tube 2, it can form a micro liquid phase molten pool between the metal tube 2 and the embedding groove 11, which is conducive to the formation of ultrasonic cavitation effect and to the realization of metallurgical bonding of the brazing interface.

[0042] 2) In addition to controlling the weld gap, the support member 3 can also play a good "double cross-penetration" strengthening role for the weld, regulate the thermal expansion coefficient of the weld, and improve the strength of the weld.

[0043] 3) After ultrasonic vibration, use a scraper or steel brush to scrape the upper surface of the metal tube 2 and the side wall of the inlay groove 11 above the metal tube 2. This helps to further remove the surface oxide film in these areas and promote the metallurgical bonding of the brazing interface.

[0044] 4) Laying a layer of two-dimensional metal mesh 10 on the surface of metal pipe 2 not only enhances the strength of the weld layer above the metal pipe and controls its thermal expansion coefficient, but also reduces the defects generated on the weld surface during solidification, making the weld surface smooth and dense.

[0045] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A brazing method for an embedded metal tube structure, the brazing method being used to manufacture the embedded metal tube structure, characterized in that, The embedded metal tube structure includes: The substrate has an inlay groove. A support member is disposed at the bottom of the inlay groove, and the support member has a mesh. Metal tube, located on the support member; and Solder is used to fill the inlay groove and the mesh, and the solder covers all parts of the outside of the metal tube; The brazing method includes the following steps: An inlay groove is created on the substrate surface; A support with mesh is placed at the bottom of the inlay groove; Place the metal tube to be brazed into the mounting groove; Pressure is applied to the metal tube using an elastic push rod; Solid solder is placed on top of a metal tube. A heating device is used to heat the metal tube and the substrate to melt the solid solder, so that the solid solder becomes liquid solder and fills the insert groove. Pressure is applied to the surface of the metal tube and ultrasonic vibration is activated; In this process, an alloy solder sheet is laid on the support member, and the alloy solder sheet is bent to form a groove, and then a metal tube is inserted into the groove for fixation.

2. The brazing method for the embedded metal tube structure according to claim 1, characterized in that, The support component is a one-dimensional metal wire, a two-dimensional metal woven mesh, or a three-dimensional metal foam, and the thickness of the support component is 0.05-1mm.

3. The brazing method for the embedded metal tube structure according to claim 1, characterized in that, It also includes the following steps: An alloy solder sheet is placed into the mounting groove. The alloy solder sheet is placed above or below the support member, or the alloy solder sheet is first combined with the support member to form a composite solder sheet, and then the composite solder sheet is placed in the mounting groove.

4. The brazing method for the embedded metal tube structure according to claim 1, characterized in that, The ultrasonic vibrator head of the ultrasonic vibrator applies ultrasonic vibrations at intervals along the metal tube from the beginning to the end.

5. The brazing method for the embedded metal tube structure according to claim 4, characterized in that, The ultrasonic vibration device has a vibration frequency of 18-40kHz, an amplitude of 8-60μm, applies a pressure of 0.1-5MPa to the metal tube, and has an ultrasonic vibration time of 10-300s. The ultrasonic loading direction includes, but is not limited to, being perpendicular to or parallel to the surface of the metal tube.

6. The brazing method for the embedded metal tube structure according to claim 4, characterized in that, The ultrasonic vibration device applies a vibration interval of 5-100mm to the metal tube, or uses a vibrating head that continuously vibrates to act on the surface of the metal tube and moves at a constant speed along the axis of the metal tube.

7. The brazing method for the embedded metal tube structure according to claim 4, characterized in that, The moving speed of the vibrating head is 0.2-2 mm / second.

8. The brazing method for the embedded metal tube structure according to claim 1, characterized in that, It also includes the following steps: Use a scraper or steel brush to scrape the upper surface of the metal tube and the side wall of the inlay groove above the metal tube, and use a tool to vertically tap the surface of the metal tube until no impurities float to the surface of the liquid alloy solder. Keep the alloy solder in the brazing seam in a liquid phase state for a period of time, stop heating, and wait for the liquid solder to completely solidify to form a metal tube embedded in the inlay groove structure.

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