Manufacturing method of high-conductivity coating composite contact tube

Abstract

The invention provides a manufacturing method of a composite contact tube with a high-conductivity coating. The manufacturing method comprises the following steps: firstly, cleaning the contact tube; secondly, the cleaned contact tube is subjected to silver pre-plating treatment; carrying out ultrasonic-assisted cyanide-free silver electroplating treatment on the contact tube subjected to silver pre-plating treatment; and finally, carrying out heat treatment on the contact tube subjected to silver plating treatment so as to form a copper-silver gradient diffusion coating on the inner wall of the wire guide hole of the contact tube. The gradient diffusion coating can effectively improve the binding force between the coating and a substrate; the surface silver-rich layer can provide good conductivity; the middle silver-copper diffusion layer can improve the mechanical property of the plating layer, and the wear resistance of the contact tube can be effectively improved; due to the gradient diffusion characteristic of the content of silver and copper, good binding force is formed between the silver plating layer and the contact tube, and the silver plating layer and the contact tube are not prone to overall falling off; in addition, due to the gradient change of the corrosion potential of the plating layer, the galvanic corrosion risk of the contact tube can be reduced when the plating layer is abraded in the wire feeding process of the contact tube.

Description

Technical Field

[0001] The invention relates to the field of aluminum alloy welding equipment, and in particular to a method for manufacturing a high-conductivity coating composite conductive nozzle. Background Art

[0002] In welding operations, the main function of the conductive tip is to effectively transfer the electrical energy from the welding machine to the welding wire, ensuring stable and reliable current transmission during welding. As a key part at the end of the welding gun, the performance of the conductive tip is directly related to the quality of welding, so choosing a high-quality conductive tip is crucial to ensure the smooth progress of welding operations.

[0003] The conductive nozzle is generally made of brass, copper, chrome-zirconium copper or beryllium copper. Copper has excellent conductivity, but its low hardness and poor wear resistance result in a short service life of the conductive nozzle. Therefore, chrome-zirconium copper conductive nozzles are currently commonly used. Although the wear resistance of chrome-zirconium copper is better than that of copper, its conductivity is lower than that of copper. However, most of the current research on chrome-zirconium copper conductive nozzles focuses on improvements in structure and wear resistance, while there is little research on improving the conductivity of chrome-zirconium copper conductive nozzles. For example, patent CN221389300U discloses a quick-install conductive nozzle, which solves the problem of cumbersome operating steps during the installation and removal of the conductive nozzle through structural improvements; patent CN219310306U discloses a wear-resistant coated conductive nozzle, which provides a wear-resistant coating on the conductive nozzle so that the conductive nozzle can maintain stable performance even in harsh working environments.

[0004] The inner wall of the wire guide hole of the conductive nozzle is the part that directly contacts the welding wire and has higher requirements for conductive performance, so it is particularly important to ensure the excellent conductivity of the inner surface of the wire guide hole. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for manufacturing a highly conductive coating composite conductive nozzle, so as to at least solve the problem that the conductivity and wear resistance of the existing conductive nozzle cannot reach the optimal state.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a method for manufacturing a highly conductive coated composite conductive nozzle, comprising the following steps: cleaning the conductive nozzle; pre-silvering the conductive nozzle after the cleaning treatment; ultrasonic-assisted cyanide-free electroplating silver treatment on the conductive nozzle after the pre-silvering treatment; heat-treating the conductive nozzle after the silvering treatment to form a copper-silver gradient diffusion coating on the inner wall of the guide wire hole.

[0007] Furthermore, the cleaning treatment of the conductive nozzle includes: using ultrasonic acetone to clean the inner wall of the guide wire hole for 5 minutes to 10 minutes; using ultrasonic ethanol to clean the inner wall of the guide wire hole for 5 minutes to 10 minutes; using ultrasonic acid pickling to clean the inner wall of the guide wire hole for 10 minutes to 20 minutes; and vacuum drying the conductive nozzle.

[0008] Furthermore, after the conductive nozzle is cleaned with ultrasonic ethanol for 5 to 10 minutes, the conductive nozzle is washed with deionized water for the first time; after the conductive nozzle is cleaned with ultrasonic acid washing for 10 to 20 minutes, the conductive nozzle is washed with deionized water for the second time.

[0009] Furthermore, after the conductive nozzle is pre-silver-plated, the manufacturing method further comprises: washing the conductive nozzle with deionized water for a third time and performing vacuum drying.

[0010] Furthermore, the conductive nozzle is pre-silver-plated, comprising: preparing a pre-plating solution with a concentration of 15 g / L silver nitrate and a concentration of 200 g / L thiourea, adjusting the pH of the pre-plating solution to 4.0, soaking the conductive nozzle in the pre-plating solution for 80 seconds, then rinsing with distilled water and drying.

[0011] Furthermore, the ultrasonic-assisted cyanide-free silver plating treatment of the conductive nozzle includes: preparing an electroplating solution with a concentration of 50-110 g / L nicotinic acid, a concentration of 15-50 g / L silver nitrate, a concentration of 40-80 g / L potassium carbonate, a concentration of 40-80 g / L ammonium acetate, and a concentration of 15-40 g / L potassium hydroxide, and adjusting the pH of the electroplating solution to 9 with ammonia water; setting the cathode current density of the electroplating to 0.1-0.8 A / dm 2 , setting the ultrasonic frequency to 40kHz, the ultrasonic power to 60W to 120W, and the electroplating time to 30min to 1h; placing the conductive nozzle in the electroplating solution for electroplating to obtain a silver-plated conductive nozzle.

[0012] Furthermore, the nicotinic acid concentration is 50 g / L, the silver nitrate concentration is 15 g / L, the potassium carbonate concentration is 40 g / L, the ammonium acetate concentration is 40 g / L, and the potassium hydroxide concentration is 15 g / L; the cathode current density of the electroplating is 0.2 A / dm 2 , the ultrasonic power is 60W, and the electroplating time is 40min.

[0013] Furthermore, the concentration of nicotinic acid is 110 g / L, the concentration of silver nitrate is 50 g / L, the concentration of potassium carbonate is 80 g / L, the concentration of ammonium acetate is 80 g / L, and the concentration of potassium hydroxide is 40 g / L; the cathode current density of the electroplating is 0.8 A / dm 2, the ultrasonic power is 120W, and the electroplating time is 30min.

[0014] Furthermore, heat treating the inner wall of the wire guide hole includes: heating the silver-plated conductive nozzle to 350°C to 800°C at a rate of 10°C / min, keeping the temperature for 6 to 24 hours, and finally obtaining a copper-silver gradient diffusion coating on the inner wall of the wire guide hole of the conductive nozzle.

[0015] Furthermore, the silver-plated conductive nozzle was heated to 750° C. at a rate of 10° C. / min and kept warm for 12 hours, and finally a copper-silver gradient diffusion coating was obtained on the inner wall of the wire guide hole of the conductive nozzle.

[0016] The manufacturing method of the conductive nozzle of the technical solution of the present invention first cleans the conductive nozzle; secondly, pre-silver-plating the conductive nozzle after the cleaning process; then, ultrasonic-assisted cyanide-free electroplating silver-plating the conductive nozzle after the pre-silver-plating process; finally, heat-treating the conductive nozzle after the silver-plating process to form a copper-silver gradient diffusion coating on the inner wall of the wire guide hole of the conductive nozzle. The gradient coating is a gradient coating of copper substrate-silver-copper diffusion layer-silver-plating layer from the inside to the outside; the gradient diffusion coating can effectively improve the bonding force between the coating and the substrate; the surface silver-rich layer can provide good electrical conductivity; the intermediate silver-copper diffusion layer can improve the mechanical properties of the coating and can effectively improve the wear resistance of the conductive nozzle; due to the gradient diffusion characteristics of the silver-copper content, the silver coating has a good bonding force with the conductive nozzle and is not easy to fall off as a whole; in addition, due to the gradient change of the corrosion potential of the coating, when the coating wears during the wire feeding process of the conductive nozzle, the risk of galvanic corrosion of the conductive nozzle can also be reduced. Therefore, the present invention achieves the transcendence of the traditional chromium-zirconium-copper conductive nozzle, and demonstrates its advantages in conductivity and wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 It is a schematic flow chart of a method for manufacturing a highly conductive coating composite conductive nozzle which can be selected according to an embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of a process for cleaning a conductive nozzle in a method for manufacturing a highly conductive coated composite conductive nozzle which can be selected according to an embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of a process of pre-silver plating a conductive tip in a method for manufacturing a highly conductive coated composite conductive tip according to an optional embodiment of the present invention;

[0021] Figure 4 The present invention is a schematic diagram of a process for electroplating a conductive nozzle in a method for manufacturing a highly conductive coated composite conductive nozzle, which may be selected according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0023] The present invention provides a method for manufacturing a highly conductive coating composite conductive nozzle, such as Figure 1 As shown, the specific steps include:

[0024] S102: cleaning the conductive nozzle of the conductive nozzle;

[0025] S104: Pre-silvering the conductive nozzle after the cleaning process;

[0026] S106: performing an ultrasonic-assisted cyanide-free electroplating silver treatment on the conductive nozzle that has undergone the pre-silver plating treatment;

[0027] S108: heat-treating the conductive nozzle that has been silver-plated to form a copper-silver gradient diffusion coating on the inner wall of the wire guide hole.

[0028] The manufacturing method of the conductive nozzle of the technical solution of the present invention first cleans the conductive nozzle; secondly, pre-silver-plating the conductive nozzle after the cleaning process; then, ultrasonic-assisted cyanide-free electroplating silver-plating the conductive nozzle after the pre-silver-plating process; finally, heat-treating the conductive nozzle after the silver-plating process to form a copper-silver gradient diffusion coating on the inner wall of the wire guide hole of the conductive nozzle. The gradient coating is a gradient coating of copper substrate-silver-copper diffusion layer-silver-plating layer from the inside to the outside; the gradient diffusion coating can effectively improve the bonding force between the coating and the substrate; the surface silver-rich layer can provide good electrical conductivity; the intermediate silver-copper diffusion layer can improve the mechanical properties of the coating and can effectively improve the wear resistance of the conductive nozzle; due to the gradient diffusion characteristics of the silver-copper content, the silver coating has a good bonding force with the conductive nozzle and is not easy to fall off as a whole; in addition, due to the gradient change of the corrosion potential of the coating, when the coating wears during the wire feeding process of the conductive nozzle, the risk of galvanic corrosion of the conductive nozzle can also be reduced. Therefore, the present invention achieves the transcendence of the traditional chromium-zirconium-copper conductive nozzle, and demonstrates its advantages in conductivity and wear resistance.

[0029] Furthermore, if Figure 2 As shown, the cleaning process of the conductive nozzle includes the following steps:

[0030] S1021: Use ultrasonic acetone to clean the contact nozzle for 5 to 10 minutes;

[0031] S1022: Use ultrasonic ethanol to clean the contact nozzle for 5 to 10 minutes;

[0032] S1023: Use ultrasonic pickling to clean the conductive nozzle for 10 to 20 minutes;

[0033] S1024: Finally, the conductive nozzle is vacuum dried.

[0034] Ultrasonic acetone cleaning can remove oil stains on the surface of the conductive nozzle, ultrasonic ethanol cleaning can remove acetone, and ultrasonic pickling can remove the oxide layer on the surface of the conductive nozzle and activate the surface at the same time, thereby increasing the bonding strength between the silver plating layer and the copper substrate. 2 SO 4 Clean for 10 minutes.

[0035] Furthermore, after the conductive nozzle is cleaned with ultrasonic ethanol for 5 to 10 minutes, the conductive nozzle is washed with deionized water for the first time to clean off the ethanol on the surface of the conductive nozzle; after the conductive nozzle is cleaned with ultrasonic acid washing for 10 to 20 minutes, the conductive nozzle is washed with deionized water for the second time to clean off the acid on the surface of the conductive nozzle.

[0036] Furthermore, after the conductive nozzle is pre-silver-plated, the manufacturing method further includes: washing the conductive nozzle with deionized water for a third time to clean off the pre-plating liquid on the surface of the conductive nozzle, and then vacuum drying.

[0037] In order to prevent the copper conductive tip from undergoing a replacement reaction with the plating solution when entering the plating solution, which would affect the stability of the plating solution and the electroplating effect, a pre-silver plating treatment is performed before electroplating. Figure 3 As shown, the pre-silvering treatment of the conductive tip includes the following steps:

[0038] S1041: preparing a pre-plating solution with 15 g / L silver nitrate and 200 g / L thiourea;

[0039] S1042: adjusting the pH of the pre-plating solution to 4.0;

[0040] S1043: Soak the conductive nozzle in the pre-plating solution for 80 seconds, then rinse with distilled water and dry.

[0041] Pre-silver plating can effectively prevent the copper conductive tip from undergoing a substitution reaction with the plating solution during electroplating.

[0042] The present invention adopts an ultrasonic-assisted cyanide-free silver electroplating process to electroplate the conductive tip. Specifically, Figure 4 As shown, the ultrasonic-assisted cyanide-free silver plating treatment of the conductive nozzle includes the following steps:

[0043] S1061: preparing an electroplating solution by mixing nicotinic acid with a concentration of 50-110 g / L, silver nitrate with a concentration of 15-50 g / L, potassium carbonate with a concentration of 40-80 g / L, ammonium acetate with a concentration of 40-80 g / L, and potassium hydroxide with a concentration of 15-40 g / L, and adjusting the pH to 9 with aqueous ammonia;

[0044] S1062: Set the cathode current density of electroplating to 0.1-0.8A / dm 2 , set the ultrasonic frequency to 40kHz, the ultrasonic power to 60W to 120W, and the electroplating time to 30min to 1h;

[0045] S1063: placing the conductive tip into an electroplating solution for electroplating to obtain a silver-plated conductive tip.

[0046] The silver plating performance of the nicotinic acid system is close to that of cyanide silver plating. The silver plating layer has a delicate appearance, good brightness and toughness. In addition, the auxiliary effect of ultrasound plays a positive role in improving the performance of the coating.

[0047] Furthermore, the heat treatment of the conductive nozzle includes: heating the silver-plated conductive nozzle to 350°C to 800°C at a rate of 10°C / min, keeping the temperature for 6 to 24 hours, and finally obtaining a copper-silver gradient diffusion coating with high conductivity and high wear resistance on the surface of the conductive nozzle. The surface silver-rich layer can provide good conductivity; the intermediate silver-copper diffusion layer can improve the mechanical properties of the coating and effectively improve the wear resistance of the conductive nozzle; due to the gradient diffusion characteristics of the silver-copper content, the silver coating has a good bonding force with the conductive nozzle and is not easy to fall off as a whole; in addition, due to the gradient change of the corrosion potential of the coating, the risk of galvanic corrosion of the conductive nozzle can also be reduced when the coating wears during the wire feeding process of the conductive nozzle.

[0048] Embodiment 1:

[0049] When the ultrasonic-assisted cyanide-free silver plating process is used to electroplate the conductive tip, the electroplating solution adopts the following ratio: nicotinic acid concentration is 50 g / L, silver nitrate concentration is 15 g / L, potassium carbonate concentration is 40 g / L, ammonium acetate concentration is 40 g / L, potassium hydroxide concentration is 15 g / L, and ammonia water is used to adjust the pH to 9; at the same time, the cathode current density of the electroplating is set to 0.2 A / dm 2 The ultrasonic frequency is set to 40kHz, the ultrasonic power is set to 60W, and the electroplating time is set to 40min. This process uses lower ultrasonic power to obtain a silver coating with fine grains and a complete surface without pinholes.

[0050] Then, the silver-plated conductive nozzle is heat treated. The process flow is: heating to 750°C at a rate of 10°C / min, keeping the temperature for 12 hours, and finally obtaining a copper-silver diffusion coating with high conductivity and high wear resistance on the surface of the conductive nozzle.

[0051] Embodiment 2:

[0052] When the ultrasonic-assisted cyanide-free silver plating process is used to electroplate the conductive tip, the electroplating solution adopts the following ratio: nicotinic acid concentration is 110 g / L, silver nitrate concentration is 50 g / L, potassium carbonate concentration is 80 g / L, ammonium acetate concentration is 80 g / L, potassium hydroxide concentration is 40 g / L, and ammonia water is used to adjust the pH to 9; at the same time, the cathode current density of the electroplating is set to 0.2 A / dm 2 , the ultrasonic frequency is set to 40kHz, the ultrasonic power is set to 60W, and the electroplating time is set to 30min. This process uses a higher concentration of plating solution, and the electroplating time is appropriately shortened to obtain a conductive nozzle that meets the process requirements.

[0053] Then, the silver-plated conductive nozzle is heat treated. The process flow is: heating to 750°C at a rate of 10°C / min, keeping the temperature for 12 hours, and finally obtaining a copper-silver diffusion coating with high conductivity and high wear resistance on the surface of the conductive nozzle.

[0054] Example 3

[0055] The conductive tip adopts the same pretreatment process, preplating process and plating solution formula as in Example 1, but adopts an ultrasonic assisted silver plating process different from that in Example 1. Specifically, the cathode current density is set to 0.8 A / dm 2 , the ultrasonic frequency is set to 40kHz, the ultrasonic power is set to 120W, the electroplating time is set to 30min and other parameters; this process can obtain a silver-plated conductive nozzle that also meets the process requirements by increasing the current density and ultrasonic power and reducing the electroplating time.

[0056] Then, the silver-plated conductive nozzle is heat treated. The process flow is: heating to 750°C at a rate of 10°C / min, keeping the temperature for 12 hours, and finally obtaining a copper-silver diffusion coating with high conductivity and high wear resistance on the surface of the conductive nozzle.

[0057] Example 4

[0058] The conductive tip adopts the same pretreatment process, pre-plating process and plating solution formula as in Example 1, but adopts an ultrasonic assisted silver plating process different from that in Example 1. Specifically, the cathode current density is set to 0.2 A / dm 2 , the ultrasonic frequency was set to 40kHz, the ultrasonic power was set to 60W, the electroplating time was set to 1h and other parameters.

[0059] Then, the silver-plated conductive tip is heat treated. The process flow is: heating to 350°C at a rate of 10°C / min, keeping the temperature for 24 hours, and finally obtaining a highly conductive copper-silver diffusion coating on the surface of the conductive tip. This process reduces the heat treatment temperature and prolongs the holding time to obtain a highly conductive silver-plated conductive tip.

[0060] Example 5

[0061] The conductive tip adopts the same pre-plating and ultrasonic-assisted cyanide-free electroplating silver plating process as in Example 1, and is modified by a heat treatment process different from that in Example 1. Specifically, the temperature is raised to 800°C at a rate of 10°C / min and kept at this temperature for 6 hours, and finally a copper-silver diffusion coating with high conductivity and high wear resistance is obtained on the surface of the conductive tip. This process increases the heat treatment temperature and reduces the holding time to obtain a silver-plated conductive tip that also meets the process requirements.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. 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 manufacturing a highly conductive coating composite conductive nozzle, characterized in that: The following steps are involved: Clean the conductive nozzle; Performing a pre-silver plating treatment on the conductive nozzle after the cleaning treatment; Performing ultrasonic-assisted cyanide-free electroplating silver treatment on the conductive nozzle that has undergone the pre-silver plating treatment; The conductive nozzle that has been silver plated is heat treated to form a copper-silver gradient diffusion coating on the inner wall of the guide wire hole.

2. The method for manufacturing a highly conductive coated composite conductive tip according to claim 1, characterized in that: The cleaning process of the conductive nozzle comprises: Using ultrasonic acetone to clean the inner wall of the wire guide hole for 5 minutes to 10 minutes; Using ultrasonic ethanol to clean the inner wall of the guide wire hole for 5 minutes to 10 minutes; The inner wall of the guide wire hole is cleaned by ultrasonic pickling for 10 to 20 minutes; The conductive nozzle is subjected to vacuum drying treatment.

3. The method for manufacturing a highly conductive coated composite conductive tip according to claim 2, characterized in that: After the conductive nozzle is cleaned with ultrasonic ethanol for 5 to 10 minutes, the conductive nozzle is washed with deionized water for the first time; after the conductive nozzle is cleaned with ultrasonic acid washing for 10 to 20 minutes, the conductive nozzle is washed with deionized water for the second time.

4. The method for manufacturing a highly conductive coated composite conductive tip according to claim 3, characterized in that: After the conductive nozzle is pre-silvered, the manufacturing method further comprises: The conductive nozzle is washed with deionized water for the third time and then vacuum dried.

5. The method for manufacturing a highly conductive coated composite conductive tip according to claim 1, characterized in that: The pre-silvering treatment of the conductive nozzle comprises: A pre-plating solution was prepared with 15 g / L silver nitrate and 200 g / L thiourea, the pH of the pre-plating solution was adjusted to 4.0, the conductive nozzle was immersed in the pre-plating solution for 80 seconds, then rinsed with distilled water and dried.

6. The method for manufacturing a highly conductive coating composite conductive tip according to claim 1, characterized in that: The ultrasonic-assisted cyanide-free silver plating treatment on the conductive nozzle comprises: Prepare an electroplating solution by mixing nicotinic acid with a concentration of 50-110 g / L, silver nitrate with a concentration of 15-50 g / L, potassium carbonate with a concentration of 40-80 g / L, ammonium acetate with a concentration of 40-80 g / L, and potassium hydroxide with a concentration of 15-40 g / L, and adjust the pH of the electroplating solution to 9 with aqueous ammonia; The cathode current density of the electroplating was set to 0.1-0.8A / dm 2 , set the ultrasonic frequency to 40kHz, the ultrasonic power to 60W to 120W, and the electroplating time to 30min to 1h; The contact tip is placed in an electroplating solution for electroplating to obtain a silver-plated contact tip.

7. The method for manufacturing a highly conductive coating composite conductive tip according to claim 6, characterized in that: The concentration of nicotinic acid is 50 g / L, the concentration of silver nitrate is 15 g / L, the concentration of potassium carbonate is 40 g / L, the concentration of ammonium acetate is 40 g / L, and the concentration of potassium hydroxide is 15 g / L; the cathode current density of the electroplating is 0.2 A / dm 2 , the ultrasonic power is 60W, and the electroplating time is 40min.

8. The method for manufacturing a highly conductive coated composite conductive tip according to claim 6, characterized in that: The concentration of nicotinic acid is 110 g / L, the concentration of silver nitrate is 50 g / L, the concentration of potassium carbonate is 80 g / L, the concentration of ammonium acetate is 80 g / L, and the concentration of potassium hydroxide is 40 g / L; the cathode current density of the electroplating is 0.8 A / dm 2 , the ultrasonic power is 120W, and the electroplating time is 30min.

9. The method for manufacturing a highly conductive coated composite conductive tip according to claim 1, characterized in that: The heat treatment of the inner wall of the guide wire hole comprises: The silver-plated conductive nozzle is heated to 350° C. to 800° C. at a rate of 10° C. / min, and kept warm for 6 to 24 hours, and finally a copper-silver gradient diffusion coating is obtained on the inner wall of the wire guide hole of the conductive nozzle.

10. The method for manufacturing a highly conductive coated composite conductive tip according to claim 9, characterized in that: The silver-plated conductive nozzle was heated to 750° C. at a rate of 10° C. / min and kept at this temperature for 12 hours, and finally a copper-silver gradient diffusion coating was obtained on the inner wall of the wire guide hole of the conductive nozzle.

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