Surface modification liquid, modification method and application for copper-plated solid welding wire

Abstract

The invention relates to a surface modification liquid for copper-plated solid welding wire, a modification method and an application thereof, and belongs to the technical field of surface treatment of welding wire for gas shielded welding. A surface modification liquid for copper-plated solid welding wire contains the following raw materials: 10.0-15.0 g of borax, 6.0-10.0 g of sodium silicate, 3.0-5.0 g of sulfur-containing antioxidant, 5.0-8.0 g of potassium iodide, 0.2-0.5 g of sodium dodecyl sulfonate, 2.0-3.0 g of thiolated chitosan, 30.0-50.0 g of thiourea, and 5.0-10.0 mL of amination multi-walled carbon nanotube NMP dispersion, wherein the content of amination multi-walled carbon nanotubes in the amination multi-walled carbon nanotube NMP dispersion is 5 mg / mL. A surface modification method for a copper-plated solid welding wire comprises: (1) preparing an etching solution; (2) preparing a surface modification solution; (3) spray etching the copper-plated solid welding wire; and (4) surface modification of the copper-plated solid welding wire. The method of the present invention improves the corrosion resistance and wire feedability of the welding wire through surface modification, and reduces large particle splashing during welding, which is of great significance to the development of gas shielded welding.

Description

Technical Field

[0001] The invention relates to a surface modification liquid for copper-plated solid core welding wire, a modification method and application thereof, and belongs to the technical field of surface treatment of welding wire for gas shielded welding. Background Art

[0002] In recent years, with the vigorous development of steel structure engineering in my country, gas shielded welding technology has been rapidly promoted. In the process of gas shielded welding, the use of solid welding wire not only has good economic benefits, but also can obtain excellent quality welds. Copper plating on the surface of solid welding wire can prevent welding wire oxidation, improve welding wire conductivity, reduce wire feeding resistance, and improve welding quality. Therefore, copper-plated solid welding wire is widely used in the field of gas shielded welding.

[0003] However, there are still many problems with copper-plated solid welding wires. In particular, the steel substrate is exposed after copper plating and drawing and sizing. It is very easy to rust, which leads to a decrease in conductivity, increased wire feeding resistance, and severe wear of the conductive nozzle, which directly affects welding efficiency and quality. In addition, copper-plated solid welding wires often have a high spatter rate and shallow penetration, which is very unfavorable for high-quality welding projects.

[0004] In order to improve the corrosion resistance of welding wire, reduce wire feeding resistance, reduce welding spatter, and increase penetration depth, the surface modification of copper-plated solid welding wire must not only complete passivation treatment, but also attach other substances on its surface, such as anti-friction materials, conductive materials, and active materials. For example, even if trace amounts of elements such as K and Na are added to the surface of the welding wire, they can improve arc stability, reduce spatter rate, and thus improve welding quality. Therefore, attaching a modified coating with both passivation and functionality on the surface of copper-plated solid welding wire and developing a new method for surface treatment of copper-plated solid welding wire are of great significance to welding engineering in the new era. Summary of the invention

[0005] In order to solve the problems of reduced conductivity, increased wire feeding resistance, unstable arc, etc. caused by easy rust on the surface of the current copper-plated solid welding wire, and to overcome welding phenomena such as high welding spatter rate, the present invention provides a surface modification liquid, modification method and application for copper-plated solid welding wire.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A surface modification liquid for a copper-plated solid welding wire contains the following raw materials: 10.0-15.0 g of borax, 6.0-10.0 g of sodium silicate, 3.0-5.0 g of a sulfur-containing antioxidant, 5.0-8.0 g of potassium iodide, 0.2-0.5 g of sodium dodecyl sulfonate, 2.0-3.0 g of thiolated chitosan, 30.0-50.0 g of thiourea, and 5.0-10.0 mL of an amination multi-walled carbon nanotube NMP dispersion liquid, wherein the content of the amination multi-walled carbon nanotube in the amination multi-walled carbon nanotube NMP dispersion liquid is 5 mg / mL.

[0008] Based on the surface modification liquid for the copper-plated solid welding wire, the preparation process is as follows: weigh borax, sodium sulfide, sodium silicate, sulfur-containing antioxidant, potassium iodide, sodium dodecyl sulfonate, thiolated chitosan and thiourea and dissolve them in 800 mL of deionized water in sequence, then add the amino multi-walled carbon nanotube NMP dispersion, stir evenly, and then add deionized water to 1000 mL to prepare the surface modification liquid.

[0009] A method for surface modification of a copper-plated solid welding wire comprises the following steps:

[0010] 1) Prepare etching solution;

[0011] 2) Preparation of surface modification solution: 10.0-15.0 g of borax, 16.0-20.0 g of sodium sulfide, 6.0-10.0 g of sodium silicate, 3.0-5.0 g of sulfur-containing antioxidant, 5.0-8.0 g of potassium iodide, 0.2-0.5 g of sodium dodecyl sulfonate, 2.0-3.0 g of thiolated chitosan and 30.0-50.0 g of thiourea were weighed and dissolved in 800 mL of deionized water, and then 5.0-10.0 mL of amination multi-walled carbon nanotube NMP dispersion was added, stirred evenly, and deionized water was added to 1000 mL to prepare a surface modification solution; wherein the content of amination multi-walled carbon nanotubes in the amination multi-walled carbon nanotube NMP dispersion was 5 mg / mL;

[0012] 3) Spray etching of copper-plated solid wire: The constant temperature of the salt spray chamber is 50 °C, and the compressed air pressure of the salt spray chamber is set to 1.00 kgf / cm 2 , after the copper-plated solid core welding wire is placed in the salt spray chamber for 3 to 5 minutes, it is taken out and washed with water to complete the spray etching of the copper-plated solid core welding wire;

[0013] 4) After the treatment in step 3), the copper-plated solid welding wire is immersed in the surface modification liquid and subjected to ultrasonic treatment. After 3 to 5 minutes, the copper-plated solid welding wire is taken out, and the surface modification of the copper-plated solid welding wire is completed after washing with water and drying.

[0014] Based on the above copper-plated solid welding wire surface modification method, the preparation process of the etching solution is as follows: 50-100 mL of glacial acetic acid is dissolved in 700 mL of deionized water and stirred evenly, and then 0.2-0.8 g of non-ionic surfactant, 0.5-2 g of hydroquinone, 50-80 g of thiourea and 5.0-10.0 g of cuprous oxide are dissolved in sequence, and after dissolution, the mixture is stirred evenly and the volume is fixed to 1000 mL.

[0015] Based on the above copper-plated solid core welding wire surface modification method, the surface modification liquid temperature in step 4) is 40~60 ℃.

[0016] Based on the surface modification method of the copper-plated solid welding wire, the non-ionic surfactant is one of OP-10, glucoside or PPE.

[0017] Based on the above copper-plated solid welding wire surface modification method, the sulfur-containing antioxidant is a combination of sodium sulfite and sodium thiosulfate, wherein the mass ratio of sodium sulfite to sodium thiosulfate is 1:2~4:1.

[0018] A copper-plated solid welding wire is obtained by the copper-plated solid welding wire surface modification method.

[0019] Working principle of the present invention:

[0020] By adding thiourea, a strong chelating agent of monovalent copper, to the etching solution, the etching solution is chelated and dissolved to produce a micro-nano surface. By adding monovalent copper, the exposed welding wire steel substrate is replaced and deposited with copper at the exposed part after contacting the etching solution, so as to better cover and protect the welding wire substrate. At the same time, in order to improve the effect of spray etching and increase the etching rate, a non-ionic surfactant is added to the etching solution to reduce the droplet particles and make it easier to infiltrate the surface of the copper-plated solid welding wire, so as to achieve the purpose of roughening the copper coating. In the preparation process of the surface modification solution, the pH of the solution is controlled to be weakly alkaline by borax, thereby promoting the formation of a passivation film. Furthermore, by adding thiourea, a strong chelating agent of monovalent copper, and sulfur ions and iodide ions, strong precipitants of monovalent copper, the copper on the surface of the copper-plated solid welding wire is promoted to be oxidized to monovalent copper and converted into monovalent copper sulfide and iodide, and the micro-nano surface obtained after the synergistic spray etching achieves the effect of passivation. Moreover, by adding sodium dodecyl sulfate to the surface modification liquid and supplementing with ultrasonic treatment during the surface modification process, the surface modification liquid can fully infiltrate the surface of the welding wire. The amino multi-walled carbon nanotubes in the surface modification liquid can be adsorbed on the surface of the coating through the action of amino groups and copper, thereby achieving the purpose of improving the conductivity and wire feeding after modification. The thiolated chitosan can be fully anchored to the copper and its oxidized surface through the thiol group, and at the same time has a certain water locking function, so that the sodium ions, potassium ions and silicate in the surface modification liquid are fixed in small amounts on the surface of the roughened copper coating after spray etching. The presence of elements such as sodium, potassium and silicon can improve the molten droplet transition morphology, improve arc stability, reduce spatter rate and increase penetration depth.

[0021] The advantages of the present invention are: it can not only improve the corrosion resistance of the copper coating, thereby solving a series of problems caused by poor corrosion resistance, such as decreased conductivity, increased wire feeding resistance, unstable arc, etc., but also can further improve the conductivity and wire feedability through the amino multi-walled carbon nanotubes fixed on the surface of the coating, and improve the droplet transition morphology through elements such as sodium, potassium, and silicon, thereby improving arc stability, reducing spatter rate, increasing penetration, and improving welding quality. It not only has good economic benefits, but also is of great significance for improving the quality of steel structure welding projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0023] Figure 1 To test the microscopic morphology of a copper-plated solid core welding wire after spray etching in step (3);

[0024] Figure 2 This is a test of the microscopic morphology of a copper-plated solid core welding wire after surface modification in step (4). DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] A surface modification method for a copper-plated solid welding wire is carried out in the following steps:

[0028] (1) Preparation of etching solution: 50-100 mL of glacial acetic acid is dissolved in 700 mL of deionized water and stirred evenly, and then 0.2-0.8 g of non-ionic surfactant, 0.5-2 g of hydroquinone, 50-80 g of thiourea and 5.0-10.0 g of cuprous oxide are dissolved in sequence, stirred evenly after dissolution and the volume is fixed to 1000 mL to prepare an etching solution; wherein the non-ionic surfactant is one of OP-10, glucoside or PPE;

[0029] (2) Preparation of surface modification liquid: 10.0-15.0 g of borax, 16.0-20.0 g of sodium sulfide, 6.0-10.0 g of sodium silicate, 3.0-5.0 g of sulfur-containing antioxidant, 5.0-8.0 g of potassium iodide, 0.2-0.5 g of sodium dodecyl sulfonate, 2.0-3.0 g of thiolated chitosan and 30.0-50.0 g of thiourea were weighed and dissolved in 800 mL of deionized water, and then 5.0-10.0 mL of amination multi-walled carbon nanotube NMP dispersion was added, stirred evenly, and deionized water was added to 1000 mL to prepare a surface modification liquid; wherein the content of amination multi-walled carbon nanotubes in the amination multi-walled carbon nanotube NMP dispersion was 5 mg / mL; wherein the sulfur-containing antioxidant is a combination of sodium sulfite and sodium thiosulfate, and the mass ratio of sodium sulfite to sodium thiosulfate is 1:2~4:1;

[0030] (3) Spray etching of copper-plated solid wire: The constant temperature of the salt spray chamber is 50 °C, and the compressed air pressure of the salt spray chamber is set to 1.00 kgf / cm 2 , after the copper-plated solid core welding wire is placed in the salt spray chamber for 3 to 5 minutes, it is taken out and washed with water to complete the spray etching of the copper-plated solid core welding wire;

[0031] (4) Surface modification of copper-plated solid welding wire: The surface modification liquid prepared in step (2) is maintained at a temperature of 40-60°C, and the copper-plated solid welding wire after the treatment in step (3) is immersed in the surface modification liquid and subjected to ultrasonic treatment. After 3-5 min, the copper-plated solid welding wire is taken out, washed with water, and blown dry to complete the surface modification of the copper-plated solid welding wire.

[0032] In this embodiment, thiourea is added to the etching solution to achieve the complex dissolution of copper by the etching solution to produce a micro-nano surface, and monovalent copper is added to make the exposed welding wire steel substrate displace and deposit copper at the exposed part after contacting the etching solution, thereby better covering and protecting the welding wire substrate. At the same time, in order to improve the effect of spray etching and increase the etching rate, a non-ionic surfactant is added to the etching solution to reduce the droplet particles and make it easier to infiltrate the surface of the copper-plated solid welding wire, thereby achieving the purpose of roughening the copper plating layer.

[0033] In the preparation process of the surface modification liquid, the pH of the solution is controlled to be weakly alkaline by borax, thereby promoting the formation of a passivation film. Furthermore, by adding a strong chelating agent for monovalent copper, thiourea, and strong precipitants for monovalent copper, sulfur ions and iodide ions, the copper on the surface of the copper-plated solid wire is promoted to be oxidized to monovalent copper and converted into monovalent copper sulfide and iodide, and the micro-nano surface obtained after synergistic spray etching achieves the effect of passivation. In addition, by adding sodium dodecyl sulfate to the surface modification liquid and supplementing with ultrasonic treatment during the surface modification process, the surface modification liquid can fully infiltrate the surface of the welding wire. The amino multi-walled carbon nanotubes in the surface modification liquid can be adsorbed on the surface of the coating through the action of amino groups and copper, thereby achieving the purpose of improving conductivity and wire feeding after modification. The thiolated chitosan can be fully anchored to the copper and its oxidized surface through the thiol group, and has a certain water-locking function, so that the sodium ions, potassium ions and silicate in the surface modification liquid are fixed in small amounts on the surface of the roughened copper coating after spray etching. The presence of elements such as sodium, potassium, and silicon can improve the droplet transition morphology, improve arc stability, reduce spatter rate, and increase melting depth.

[0034] The surface modification method of a copper-plated solid welding wire in this embodiment can not only improve the corrosion resistance of the copper coating, thereby solving a series of problems caused by poor corrosion resistance, such as decreased conductivity, increased wire feeding resistance, and unstable arc, but also further improve the conductivity and wire feedability through the amino multi-walled carbon nanotubes fixed on the surface of the coating, and improve the droplet transition morphology through elements such as sodium, potassium, and silicon, thereby improving arc stability, reducing spatter rate, increasing penetration, and improving welding quality. It not only has good economic benefits, but also is of great significance for improving the quality of steel structure welding projects.

[0035] Example 2

[0036] The difference between this specific embodiment and specific embodiment 1 is that the nonionic surfactant in step (1) is one of OP-10, glucoside or PPE. The rest is the same as specific embodiment 1.

[0037] The following test verifies that the present invention has a beneficial effect when used for surface modification of copper-plated solid welding wire:

[0038] Test 1: This test is a copper-plated solid core welding wire surface modification method, which is carried out according to the following steps:

[0039] (1) Preparation of etching solution: 100 mL of glacial acetic acid was dissolved in 700 mL of deionized water and stirred evenly. Then, 0.2 g of OP-10, 1.0 g of hydroquinone, 50 g of thiourea and 7.0 g of cuprous oxide were dissolved in sequence. After dissolution, the mixture was stirred evenly and the volume was fixed to 1000 mL to prepare the etching solution.

[0040] (2) Preparation of surface modification liquid: 15.0 g of borax, 16.0 g of sodium sulfide, 10.0 g of sodium silicate, 5.0 g of sulfur-containing antioxidant, 8.0 g of potassium iodide, 0.2 g of sodium dodecyl sulfonate, 2.0 g of thiolated chitosan and 50.0 g of thiourea were weighed and dissolved in 800 mL of deionized water, and then 10.0 mL of amination multi-walled carbon nanotube NMP dispersion was added, stirred evenly, and deionized water was added to 1000 mL to prepare a surface modification liquid; wherein the content of amination multi-walled carbon nanotubes in the amination multi-walled carbon nanotube NMP dispersion was 5 mg / mL; wherein the sulfur-containing antioxidant was a combination of sodium sulfite and sodium thiosulfate, and the mass ratio of sodium sulfite to sodium thiosulfate was 1:1;

[0041] (3) Spray etching of copper-plated solid welding wire: The temperature of the salt spray chamber is kept constant at 50 °C, and the compressed air pressure of the salt spray chamber is set to 1.00 kgf / cm2. After 5 min in the salt spray chamber, the φ 1.2 mm copper-plated solid welding wire is taken out and washed with water to complete the spray etching of the copper-plated solid welding wire.

[0042] (4) Surface modification of copper-plated solid welding wire: The surface modification liquid prepared in step (2) is maintained at 40°C, and the copper-plated solid welding wire after the treatment in step (3) is immersed in the surface modification liquid and subjected to ultrasonic treatment. After 5 min, the copper-plated solid welding wire is taken out, washed with water, and blown dry to complete the surface modification of the copper-plated solid welding wire.

[0043] from Figure 1 It can be seen that the copper plating layer on the surface of the welding wire is microscopically rough after spray etching, which is not only conducive to the subsequent construction of a low surface energy passivation film, but also more conducive to the coordinated thiolated chitosan locking of substances with welding active ingredients during the surface modification process. Figure 2 It can be seen that after surface modification, carbon nanotubes are adsorbed on the surface of the copper-plated welding wire, which is beneficial to reduce the friction coefficient and improve the wear problem of the conductive nozzle during welding.

[0044] Test 2: The surface modification method of a copper-plated solid welding wire in this test is carried out according to the following steps:

[0045] (1) Preparation of etching solution: 50 mL of glacial acetic acid was dissolved in 700 mL of deionized water and stirred evenly. Then, 0.8 g of glucoside, 2.0 g of hydroquinone, 80 g of thiourea and 10.0 g of cuprous oxide were dissolved in sequence. After dissolution, the mixture was stirred evenly and the volume was fixed to 1000 mL to prepare etching solution.

[0046] (2) Preparation of surface modification liquid: 10.0 g of borax, 20.0 g of sodium sulfide, 6.0 g of sodium silicate, 3.0 g of sulfur-containing antioxidant, 5.0 g of potassium iodide, 0.5 g of sodium dodecyl sulfonate, 3.0 g of thiolated chitosan and 30.0 g of thiourea were weighed and dissolved in 800 mL of deionized water, and then 5.0 mL of amination multi-walled carbon nanotube NMP dispersion was added. After stirring evenly, deionized water was added to 1000 mL to prepare a surface modification liquid; wherein the content of amination multi-walled carbon nanotubes in the amination multi-walled carbon nanotube NMP dispersion was 5 mg / mL; wherein the sulfur-containing antioxidant was a combination of sodium sulfite and sodium thiosulfate, and the mass ratio of sodium sulfite to sodium thiosulfate was 1:2;

[0047] (3) Spray etching of copper-plated solid welding wire: The temperature of the salt spray chamber is kept constant at 50 °C, and the compressed air pressure of the salt spray chamber is set to 1.00 kgf / cm2. After 3 min in the salt spray chamber, the φ 1.2 mm copper-plated solid welding wire is taken out and washed with water to complete the spray etching of the copper-plated solid welding wire.

[0048] (4) Surface modification of copper-plated solid welding wire: The surface modification liquid prepared in step (2) is maintained at 60°C, and the copper-plated solid welding wire after the treatment in step (3) is immersed in the surface modification liquid and subjected to ultrasonic treatment. After 3 min, the copper-plated solid welding wire is taken out, washed with water, and blown dry to complete the surface modification of the copper-plated solid welding wire.

[0049] Test 3: The surface modification method of a copper-plated solid core welding wire in this test is carried out according to the following steps:

[0050] (1) Preparation of etching solution: 60 mL of glacial acetic acid was dissolved in 700 mL of deionized water and stirred evenly. Then, 0.5 g of PPE, 0.5 g of hydroquinone, 60 g of thiourea and 5.0 g of cuprous oxide were dissolved in sequence. After dissolution, the mixture was stirred evenly and the volume was fixed to 1000 mL to prepare etching solution.

[0051] (2) Preparation of surface modification liquid: 13.0 g of borax, 18.0 g of sodium sulfide, 8.0 g of sodium silicate, 3.5 g of sulfur-containing antioxidant, 6.5 g of potassium iodide, 0.3 g of sodium dodecyl sulfonate, 2.5 g of thiolated chitosan and 40.0 g of thiourea were weighed and dissolved in 800 mL of deionized water, and then 7.0 mL of amination multi-walled carbon nanotube NMP dispersion was added. After stirring evenly, deionized water was added to 1000 mL to prepare a surface modification liquid; wherein the content of amination multi-walled carbon nanotubes in the amination multi-walled carbon nanotube NMP dispersion was 5 mg / mL; wherein the sulfur-containing antioxidant was a combination of sodium sulfite and sodium thiosulfate, and the mass ratio of sodium sulfite to sodium thiosulfate was 4:1;

[0052] (3) Spray etching of copper-plated solid welding wire: The temperature of the salt spray chamber is kept constant at 50 °C, and the compressed air pressure of the salt spray chamber is set to 1.00 kgf / cm2. After 4 min of exposure to the salt spray chamber, the copper-plated solid welding wire with a diameter of 1.2 mm is taken out and washed with water to complete the spray etching of the copper-plated solid welding wire.

[0053] (4) Surface modification of copper-plated solid welding wire: The surface modification liquid prepared in step (2) is maintained at 50°C, and the copper-plated solid welding wire after the treatment in step (3) is immersed in the surface modification liquid and subjected to ultrasonic treatment. After 4 min, the copper-plated solid welding wire is taken out, washed with water, and blown dry to complete the surface modification of the copper-plated solid welding wire.

[0054] The corrosion resistance of the copper-plated solid core welding wire after surface modification in Tests 1 to 3 was tested by a neutral salt spray test. A 5% NaCl solution was used as the corrosive medium. The working temperature of the salt spray box was set to 35 °C, and the compressed air pressure of the salt spray box was set to 1.00 kgf / cm. The neutral salt spray test results are shown in Table 1.

[0055] Table 1 Neutral salt spray test results of copper-plated solid welding wire before and after surface modification

[0056] The copper-plated solid core welding wires after surface modification in Tests 1 to 3 were treated in a neutral salt spray test chamber for 3 hours before welding. The current was set to 110 A, the voltage was 20 V, the wire feeding speed was 2.0 m / min, and the carbon dioxide flow rate was 20 L / min. The results are shown in Table 2.

[0057] Table 2 Comparison of welding performance of copper-plated solid welding wire before and after surface modification

[0058]

[0059] It can be seen from Table 1 and Table 2 that after the surface modification of Tests 1 to 3, the corrosion resistance, wire feedability and arc stability of the welding wire obtained are significantly improved, the spatter rate is significantly reduced, and the obtained weld is beautiful and has a deep penetration, which significantly improves the welding quality.

[0060] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for surface modification of a copper-plated solid welding wire, characterized in that: The following steps are involved: 1) Prepare etching solution: 50-100 mL of glacial acetic acid is dissolved in 700 mL of deionized water and stirred evenly, then 0.2-0.8 g of nonionic surfactant, 0.5-2 g of hydroquinone, 50-80 g of thiourea and 5.0-10.0 g of cuprous oxide are dissolved in turn, stirred evenly after dissolution and fixed to 1000 mL to prepare etching solution; 2) Preparation of surface modification solution: 10.0-15.0 g of borax, 16.0-20.0 g of sodium sulfide, 6.0-10.0 g of sodium silicate, 3.0-5.0 g of sulfur-containing antioxidant, 5.0-8.0 g of potassium iodide, 0.2-0.5 g of sodium dodecyl sulfonate, 2.0-3.0 g of thiolated chitosan and 30.0-50.0 g of thiourea were weighed and dissolved in 800 mL of deionized water, and then 5.0-10.0 mL of amination multi-walled carbon nanotube NMP dispersion was added, stirred evenly, and deionized water was added to 1000 mL to prepare a surface modification solution; wherein the content of amination multi-walled carbon nanotubes in the amination multi-walled carbon nanotube NMP dispersion was 5 mg / mL; 3) Spray etching of copper-plated solid wire: The constant temperature of the salt spray chamber is 50 °C, and the compressed air pressure of the salt spray chamber is set to 1.00 kgf / cm 2 , after the copper-plated solid core welding wire is placed in the salt spray chamber for 3 to 5 minutes, it is taken out and washed with water to complete the spray etching of the copper-plated solid core welding wire; 4) After the treatment in step 3), the copper-plated solid welding wire is immersed in the surface modification liquid and subjected to ultrasonic treatment. After 3 to 5 minutes, the copper-plated solid welding wire is taken out, and the surface modification of the copper-plated solid welding wire is completed after washing with water and drying.

2. The surface modification method of copper-plated solid welding wire according to claim 1, characterized in that: In step 4), the temperature of the surface modification liquid is 40-60 °C.

3. The surface modification method of copper-plated solid welding wire according to claim 1, characterized in that: The nonionic surfactant is one of OP-10, glucoside or PPE.

4. The surface modification method of copper-plated solid welding wire according to claim 1, characterized in that: The sulfur-containing antioxidant is a combination of sodium sulfite and sodium thiosulfate, wherein the mass ratio of sodium sulfite to sodium thiosulfate is 1:2~4:

1.

5. A copper-plated solid welding wire, characterized in that: The copper-plated solid welding wire is obtained by the surface modification method of any one of claims 1 to 4.

Images