A copper alloy thin-walled tube plasma liquid nanopolishing solution and a polishing method

Abstract

The application provides a copper alloy thin-walled tube plasma liquid nanometer polishing solution and a polishing method. The copper alloy thin-walled tube plasma liquid nanometer polishing solution uses an organic weak acid salt as a main salt, effectively reduces the degree of electrochemical reaction to avoid local overheating, uses an amino acid complexing agent to effectively complex copper ions dissolved in the polishing process of the copper alloy thin-walled tube to prevent secondary hydrolysis and oxidation, and uses an alcohol amine protective agent and a polyether leveling agent to cooperatively protect a sharp microstructure and regulate surface film formation, so that geometric shape high-fidelity polishing is realized, and the advantages of preventing local excessive melting of an end bevel sharp head, accurately controlling a wall thickness thinning rate, and inhibiting copper ion oxidation to keep a surface bright without an oxidation film are achieved.

Description

Technical Field

[0001] This application relates to the field of metal surface treatment technology, specifically to a copper alloy thin-walled tube plasma liquid nanopolishing slurry and a polishing method using the copper alloy thin-walled tube plasma liquid nanopolishing slurry. Background Technology

[0002] Copper alloy precision thin-walled tubes with beveled pointed ends are key components of high-end precision instruments. Their surface treatment must simultaneously meet the stringent requirements of being burr-free, having high geometric fidelity, and having a bright, oxide-free surface.

[0003] Existing plasma liquid nanopolishing technology uses low-concentration inorganic salt polishing slurries, which has significant drawbacks when processing ultra-thin copper alloy tubes with sharp microstructures. Under the action of a high-voltage electric field, areas with extreme curvature, such as beveled tips, experience severe localized erosion due to the highly concentrated electric field lines. This causes the originally sharp tips to quickly become blunt and rounded, resulting in geometrical failure.

[0004] Meanwhile, traditional inorganic salt systems react violently, making it difficult to control the thinning rate of ultra-thin walled tubes, which can easily lead to excessive wall thinning or even localized breakdown and scrapping. Furthermore, copper ions dissolved during polishing are prone to secondary hydrolysis and oxidation at high temperatures, forming black and red oxide patches that adhere to the surface, preventing the pure metallic color from being maintained after polishing. Existing technologies lack both mechanisms to prevent excessive corrosion in response to microscopic sharp structures and effective measures to inhibit copper ion oxidation, making it difficult to meet the processing requirements of precision instrument components.

[0005] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0006] The purpose of this application is to provide a copper alloy thin-walled tube plasma liquid nanopolishing slurry and a polishing method using the copper alloy thin-walled tube plasma liquid nanopolishing slurry, which has the advantages of preventing local excessive melting of the end beveled tip of the copper alloy precision thin-walled tube with beveled tip structure, accurately controlling the wall thickness reduction rate, and inhibiting copper ion oxidation to maintain a bright surface without oxide film.

[0007] To achieve the above-mentioned objective, this invention provides a copper alloy thin-walled tube plasma liquid nanopolishing solution; used for polishing copper alloy precision thin-walled tubes with beveled tips at the ends, wherein the copper alloy thin-walled tube plasma liquid nanopolishing solution comprises, by total mass percentage: Main salt: 3.0%–4.5%, wherein the main salt is an organic weak acid salt; Complexing agent: 1.0%–1.5%, wherein the complexing agent is an amino acid compound; The protective agent is 0.5% to 1.0%, and the protective agent is an alcohol amine compound; The leveling agent is 0.5% to 1.0%, and the leveling agent is a polyether compound; The remainder is water; The total mass percentage of the main salt, complexing agent, protective agent, and leveling agent is controlled within the range of 5% to 8%.

[0008] As a further improvement of the present invention, the main salt is sodium acetate, the complexing agent is glycine, the protective agent is triethanolamine, and the leveling agent is polyethylene glycol 400.

[0009] To achieve the above-mentioned objective, the present invention also provides a polishing method for polishing a copper alloy precision thin-walled tube with a beveled tip at the end. The polishing method includes the following steps: S1. Preparation of polishing slurry: Weigh 3.0% to 4.5% of main salt, 1.0% to 1.5% of complexing agent, 0.5% to 1.0% of protective agent, and 0.5% to 1.0% of leveling agent by mass percentage, add them to water and stir until completely dissolved to obtain a copper alloy thin-walled tube plasma liquid nanopolishing slurry with a total concentration of 5% to 8%. S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the copper alloy thin-walled tube plasma liquid nano-polishing liquid contained in the polishing tank through the polishing tank; and immerse the copper alloy precision thin-walled tube to be processed in the copper alloy thin-walled tube plasma liquid nano-polishing liquid for polishing. S3. Post-processing: After polishing, the copper alloy precision thin-walled tube is removed from the copper alloy thin-walled tube plasma liquid nano-polishing solution, immediately rinsed with water, and quickly dried to remove moisture from the surface of the copper alloy precision thin-walled tube.

[0010] As a further improvement of the present invention, in S1, the main salt is sodium acetate, the complexing agent is glycine, the protective agent is triethanolamine, and the leveling agent is polyethylene glycol 400.

[0011] As a further improvement of the present invention, in step S2, the temperature of the copper alloy thin-walled tube plasma liquid nanopolishing solution is controlled to be 85~90℃ during the polishing process.

[0012] As a further improvement of the present invention, in step S2, the voltage of the power supply is 300V; and the polishing time for a single polishing is 30±5s.

[0013] As a further improvement of the present invention, in step S3, the rapid drying specifically refers to drying at 80℃±5℃ for 5±0.5min.

[0014] The beneficial effects of this invention are as follows: The plasma liquid nanopolishing slurry for copper alloy thin-walled tubes of this application uses organic weak acid salts as the main salt to effectively reduce the intensity of electrochemical reactions and avoid local overheating. The use of amino acid complexing agents can effectively complex copper ions dissolved during the polishing process of copper alloy precision thin-walled tubes to prevent secondary hydrolysis and oxidation. The use of alcohol amine protective agents and polyether leveling agents can synergistically protect the tip microstructure and regulate the surface film formation, thereby achieving high-fidelity polishing of geometric shapes. It has the advantages of preventing excessive local melting of the beveled tip, precisely controlling the wall thickness reduction rate, and inhibiting copper ion oxidation to maintain a bright surface without oxide film. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a flowchart of the polishing method of the present invention; Figure 2 This is a trend graph showing the gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 1. Figure 3 This is a trend graph showing the gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 2. Figure 4 This is a trend graph showing the gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 3. Figure 5 This is a trend graph showing the gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 4. Figure 6 This is a trend graph showing the gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 5. Figure 7 The graph shows the trend of gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Comparative Example 1. Figure 8 The graph shows the trend of gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Comparative Example 2. Figure 9 The graph shows the trend of gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Comparative Example 3. Figure 10 This is a trend graph showing the gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Comparative Example 4. Detailed Implementation

[0017] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0018] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0019] Traditional plasma-liquid nanopolishing technology suffers from several problems when processing precision thin-walled copper alloy tubes with beveled tips. These problems include tip burn-out due to over-discharge, resulting in blunting and rounding of the tips; uncontrollable tube wall thinning rate or even breakdown; and the formation of a discolored oxide film with alternating black and red hues on the polished surface. Furthermore, traditional polishing slurries often contain ammonia nitrogen or phosphates, leading to high wastewater treatment costs and poor environmental performance.

[0020] To address this issue, this application proposes a plasma liquid nanopolishing slurry for polishing copper alloy thin-walled tubes with beveled tips. This plasma liquid nanopolishing slurry comprises, by total mass percentage, functional components such as a main salt, complexing agent, protective agent, and leveling agent, with the remainder being water. The total mass percentage of each functional component in the plasma liquid nanopolishing slurry is controlled within the range of 5% to 8%. Furthermore, by controlling the types and proportions of each functional component, it effectively solves the problems in existing technologies, such as poor microstructure preservation, uncontrollable thinning rate, easy surface oxidation and discoloration, and poor environmental friendliness of copper alloy precision thin-walled tubes with beveled tips after polishing.

[0021] In this application, the copper alloy thin-walled tube plasma liquid nanopolishing solution comprises: Main salt: 3.0% to 4.5%; wherein, the main salt is used to provide conductivity in the plasma liquid nanopolishing slurry for copper alloy thin-walled tubes to maintain plasma excitation and stabilize the pH value of the plasma liquid nanopolishing slurry for copper alloy thin-walled tubes; in this application, the main salt is an organic weak acid salt; such a setting can provide a certain buffering capacity while providing appropriate conductivity; preferably, the main salt is sodium acetate.

[0022] Complexing agent: 1.0% to 1.5%, wherein the complexing agent can form a stable complex with the metal ions (e.g., copper ions) generated during polishing in the plasma liquid nanopolishing solution for copper alloy thin-walled tubes, thereby inhibiting the secondary hydrolysis and oxidation of metal ions during the polishing process; in this application, the complexing agent is an amino acid compound to effectively complex the copper ions generated during the polishing process of copper alloy precision thin-walled tubes, effectively inhibiting the secondary hydrolysis and oxidation of copper ions in the high-temperature copper alloy thin-walled tube plasma liquid nanopolishing solution, thereby avoiding the formation of discolored films such as copper oxide or cuprous oxide on the surface of copper alloy precision thin-walled tubes; preferably, the complexing agent is glycine.

[0023] Protective agent: 0.5%~1.0%, wherein the protective agent can be adsorbed on the high electric field region of the plasma polished surface of the workpiece to form a barrier layer to prevent local excessive melting, thereby protecting the polished microstructure of the copper alloy precision thin-walled tube with beveled tips; in this application, the protective agent is an alkanolamine compound; subsequently, under the action of the electric field during the polishing process, it is directionally adsorbed to the high electric field region at the tip of the copper alloy precision thin-walled tube to form a high-viscosity barrier layer; effectively shielding the locally concentrated electric field energy, preventing the tip from melting and rounding due to excessive electrochemical corrosion, and ensuring the fidelity of the microstructure of the copper alloy precision thin-walled tube with beveled tips after polishing; preferably, the protective agent is triethanolamine.

[0024] Leveling agent: 0.5%–1.0%, wherein the leveling agent can effectively improve the wettability of the plasma liquid nanopolishing slurry for copper alloy thin-walled tubes, stabilize the plasma gas film during the plasma polishing process, and promote the surface flatness of the copper alloy precision thin-walled tubes; in this application, the leveling agent is a polyether compound; this setting can effectively improve the interfacial properties of the plasma liquid nanopolishing slurry for copper alloy thin-walled tubes, thereby stabilizing the morphology of the plasma gas film during the plasma liquid nanopolishing process and promoting the uniform peeling of micro-protrusions on the surface of the copper alloy precision thin-walled tubes. This helps to improve the surface flatness and gloss after polishing. Preferably, the leveling agent is polyethylene glycol 400.

[0025] Furthermore, the remainder in the plasma liquid nanopolishing slurry for copper alloy thin-walled tubes is water; and the total mass percentage of the main salt, complexing agent, protective agent, and leveling agent in the plasma liquid nanopolishing slurry for copper alloy thin-walled tubes is controlled within the range of 5% to 8%. This setting ensures that each functional component can play a synergistic role in the polishing process, providing sufficient conductivity and active material to achieve efficient polishing, while avoiding excessively violent reactions or increased costs due to excessive concentration. At the same time, it controls the thinning amount of the copper alloy precision thin-walled tube with beveled tips within an acceptable range.

[0026] For further details, please refer to Figure 1As shown, this application also provides a polishing method for polishing a copper alloy precision thin-walled tube with a beveled tip at the end. The polishing method includes the following steps: S1. Preparation of polishing slurry: Weigh 3.0% to 4.5% of main salt, 1.0% to 1.5% of complexing agent, 0.5% to 1.0% of protective agent, and 0.5% to 1.0% of leveling agent by mass percentage, add them to water and stir until completely dissolved to obtain a copper alloy thin-walled tube plasma liquid nanopolishing slurry with a total concentration of 5% to 8%. S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the copper alloy thin-walled tube plasma liquid nano-polishing liquid contained in the polishing tank through the polishing tank; then immerse the copper alloy precision thin-walled tube to be processed in the copper alloy thin-walled tube plasma liquid nano-polishing liquid for polishing. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the copper alloy thin-walled tube plasma liquid nano-polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0027] The following instruction manual will provide detailed explanations of S1 to S3.

[0028] In S1, the polishing solution is the aforementioned copper alloy thin-walled tube plasma liquid nanopolishing solution. Specifically, the main salt is sodium acetate, the complexing agent is glycine, the protective agent is triethanolamine, and the leveling agent is polyethylene glycol 400. Sodium acetate provides a stable electrochemical environment for the polishing process, glycine effectively prevents the surface of the polished copper alloy precision thin-walled tube from being oxidized and discolored again, triethanolamine precisely protects the pointed end structure of the copper alloy precision thin-walled tube from passivation, and the use of polyethylene glycol 400 ensures improved surface smoothness of the copper alloy precision thin-walled tube after polishing. In other words, by setting the components and formulation of the copper alloy thin-walled tube plasma liquid nanopolishing solution, precise control of the microstructure of the precision thin-walled tube can be achieved while ensuring polishing efficiency, effectively solving the geometric distortion and surface oxidation problems that easily occur in traditional polishing systems when dealing with complex microstructures.

[0029] In S2, the temperature of the copper alloy thin-walled tube plasma liquid nanopolishing slurry during the polishing process is controlled at 85~90℃. Specifically, the temperature of the copper alloy thin-walled tube plasma liquid nanopolishing slurry is a key parameter in the plasma liquid nanopolishing process, affecting the physicochemical properties of the slurry and the formation and stability of the plasma gas film. By controlling the temperature of the copper alloy thin-walled tube plasma liquid nanopolishing slurry at 85~90℃ during the polishing process, the viscosity of the slurry can be ensured to be moderate, which is conducive to the migration and mass transfer of ions during the polishing process. This promotes the formation of a uniform and stable plasma gas film on the surface of the copper alloy precision thin-walled tube with beveled tips, thereby ensuring the uniformity of arc discharge during the polishing process, effectively avoiding uneven local discharge caused by temperature fluctuations, and improving the removal effect of micro-burrs. In a preferred embodiment of this application, the heating of the copper alloy thin-walled tube plasma liquid nanopolishing slurry can be achieved by a heating element disposed in the polishing tank. Furthermore, a temperature sensor is also disposed in the polishing tank to facilitate monitoring of the heating temperature of the copper alloy thin-walled tube plasma liquid nanopolishing slurry.

[0030] In fact, during the polishing process of copper alloy precision thin-walled tubes, if there is a lack of precise control over the electric field strength and processing time during the polishing process, it is very easy to cause the tip of the copper alloy precision thin-walled tube with beveled tip to over-burn, the tube wall thinning to become uncontrolled, or even break down, and it is difficult to guarantee the stability of polishing efficiency and surface quality.

[0031] Based on this, during the S2 polishing process, the power supply voltage is controlled at 300V. This setting ensures that the plasma liquid nanopolishing slurry for copper alloy thin-walled tubes can be stably excited and maintain the plasma gas film, while avoiding over-discharge and burning of the tip of the copper alloy precision thin-walled tube with beveled tip due to excessive voltage or low polishing efficiency due to insufficient voltage.

[0032] Furthermore, in S2, the polishing time for a single polishing session is controlled to be 30±5s to effectively remove surface burrs from the copper alloy precision thin-walled tube with beveled tips, while preventing the tube wall thinning from exceeding expectations due to over-processing.

[0033] In some of the solutions described above in this application, a method for polishing copper alloy precision thin-walled tubes is proposed. However, in the post-polishing process, if the moisture on the surface of the tube cannot be removed in a timely and thorough manner, the residual moisture can easily cause secondary oxidation or corrosion on the copper alloy surface, thereby destroying the pure metallic luster obtained after polishing and affecting the surface quality of the final product.

[0034] Specifically, S3 involves: after polishing, removing the copper alloy precision thin-walled tube from the copper alloy thin-walled tube plasma liquid nano-polishing solution, rinsing it immediately with water, and drying it at 80℃±5℃ for 5±0.5min to quickly remove moisture from the surface of the copper alloy precision thin-walled tube.

[0035] Specifically, after polishing, the surface of the copper alloy precision thin-walled tube is in a highly activated state. While rinsing removes the copper alloy thin-walled tube's plasma liquid nano-polishing solution and prevents over-polishing, the activated copper alloy precision thin-walled tube is still highly susceptible to reaction with oxygen in the air and residual moisture from the rinsing process. In this application, by precisely controlling the drying temperature within the range of 80℃±5℃, heat energy is efficiently utilized to accelerate moisture evaporation while avoiding problems such as thermal stress on the metal surface and unnecessary oxidation discoloration caused by excessively high temperatures. Furthermore, by controlling the drying time to 5±0.5 min, it is ensured that moisture on the surface and in the tiny gaps of the copper alloy precision thin-walled tube can be completely removed, effectively blocking the conditions for secondary oxidation or corrosion reactions. This plays a crucial role in maintaining the pure metallic color of the polished copper alloy precision thin-walled tube and preventing surface quality deterioration, ensuring the final geometric accuracy and appearance quality of the polished copper alloy precision thin-walled tube.

[0036] The polishing method of this application will be described in detail below through specific embodiments.

[0037] Example 1 S1. Preparation of polishing slurry: Weigh 3.0% sodium acetate, 1.0% glycine, 0.5% triethanolamine and 0.5% PEG-400 by mass percentage, add them to water and stir until completely dissolved to obtain a copper alloy thin-walled tube plasma liquid nanopolishing slurry with a total concentration of 5%. S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the copper alloy thin-walled tube plasma liquid nano-polishing liquid contained in the polishing tank through the polishing tank; and immerse the copper alloy precision thin-walled tube to be processed in the copper alloy thin-walled tube plasma liquid nano-polishing liquid and polish it at 86°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the copper alloy thin-walled tube plasma liquid nano-polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0038] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tubes are shown in Table 1 below. Figure 2 As shown.

[0039] Table 1. Gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 1.

[0040] Example 2 S1. Preparation of polishing slurry: Weigh 3.8% sodium acetate, 1.2% glycine, 0.8% triethanolamine and 0.8% PEG-400 by mass percentage, add them to water and stir until completely dissolved to obtain a copper alloy thin-walled tube plasma liquid nanopolishing slurry with a total concentration of 6.6%. S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the copper alloy thin-walled tube plasma liquid nano-polishing liquid contained in the polishing tank through the polishing tank; and immerse the copper alloy precision thin-walled tube to be processed in the copper alloy thin-walled tube plasma liquid nano-polishing liquid and polish it at 88°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the copper alloy thin-walled tube plasma liquid nano-polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0041] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tube are shown in Table 2 below. Figure 3 As shown.

[0042] Table 2. Gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 2.

[0043] Example 3 S1. Preparation of polishing slurry: Weigh 4.5% sodium acetate, 1.5% glycine, 1.0% triethanolamine and 1.0% PEG-400 by mass percentage, add them to water and stir until completely dissolved to obtain a copper alloy thin-walled tube plasma liquid nanopolishing slurry with a total concentration of 8.0%. S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the copper alloy thin-walled tube plasma liquid nano-polishing liquid contained in the polishing tank through the polishing tank; and immerse the copper alloy precision thin-walled tube to be processed in the copper alloy thin-walled tube plasma liquid nano-polishing liquid and polish it at 89°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the copper alloy thin-walled tube plasma liquid nano-polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0044] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tubes are shown in Table 3 below. Figure 4 As shown.

[0045] Table 3. Gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 3.

[0046] Example 4 S1. Preparation of polishing slurry: Weigh 4.0% sodium acetate, 1.5% glycine, 0.5% triethanolamine and 1.0% PEG-400 by mass percentage, add to water and stir until completely dissolved to obtain a copper alloy thin-walled tube plasma liquid nanopolishing slurry with a total concentration of 7.0%. S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the copper alloy thin-walled tube plasma liquid nano-polishing liquid contained in the polishing tank through the polishing tank; and immerse the copper alloy precision thin-walled tube to be processed in the copper alloy thin-walled tube plasma liquid nano-polishing liquid and polish it at 87°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the copper alloy thin-walled tube plasma liquid nano-polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0047] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tube are shown in Table 4 below. Figure 5 As shown.

[0048] Table 4. Gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 4.

[0049] Example 5 S1. Preparation of polishing slurry: Weigh 3.5% sodium acetate, 1.0% glycine, 1.0% triethanolamine and 0.5% PEG-400 by mass percentage, add them to water and stir until completely dissolved to obtain a copper alloy thin-walled tube plasma liquid nanopolishing slurry with a total concentration of 6.0%. S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the copper alloy thin-walled tube plasma liquid nano-polishing liquid contained in the polishing tank through the polishing tank; and immerse the copper alloy precision thin-walled tube to be processed in the copper alloy thin-walled tube plasma liquid nano-polishing liquid and polish it at 85°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the copper alloy thin-walled tube plasma liquid nano-polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0050] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tube are shown in Table 5 below. Figure 6 As shown.

[0051] Table 5. Gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Example 5.

[0052] Comparative Example 1 S1. Preparation of polishing solution: Weigh 3.8% sodium acetate, 1.2% glycine and 0.8% PEG-400 by mass percentage, add to water and stir until completely dissolved to obtain polishing solution (using the formula of Example 2, the difference being: no triethanolamine added). S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the polishing liquid contained in the polishing tank through the polishing tank; then immerse the copper alloy precision thin-walled tube to be processed in the polishing liquid and polish it at 88°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0053] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tubes are shown in Table 6 below. Figure 7 As shown.

[0054] Table 6. Gloss and wall thickness reduction of the polished copper alloy precision thin-walled tube in Comparative Example 1.

[0055] Comparative Example 2 S1. Preparation of polishing solution: Weigh 3.8% sodium acetate, 0.8% triethanolamine and 0.8% PEG-400 by mass percentage, add to water and stir until completely dissolved to obtain polishing solution (using the formula of Example 2, the difference being that glycine was not added). S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the polishing liquid contained in the polishing tank through the polishing tank; then immerse the copper alloy precision thin-walled tube to be processed in the polishing liquid and polish it at 88°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0056] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tubes are shown in Table 7 below. Figure 8 As shown.

[0057] Table 7 Comparative Example 2: Gloss and Wall Thickness Reduction of Polished Copper Alloy Precision Thin-Walled Tubes

[0058] Comparative Example 3 S1. Preparation of polishing solution: Weigh 3.8% sodium acetate, 1.2% glycine and 0.8% triethanolamine by mass percentage, add them to water and stir until completely dissolved to obtain polishing solution (using the formula of Example 2, the difference being: no PEG-400 added). S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the polishing liquid contained in the polishing tank through the polishing tank; then immerse the copper alloy precision thin-walled tube to be processed in the polishing liquid and polish it at 88°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0059] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tubes are shown in Table 8 below. Figure 9 As shown.

[0060] Table 8. Gloss and wall thickness reduction of the polished copper alloy precision thin-walled tubes in Comparative Example 3.

[0061] Comparative Example 4 S1. Preparation of polishing solution: Weigh 1.2% glycine, 0.8% triethanolamine and 0.8% PEG-400 by mass percentage, add to water and stir until completely dissolved to obtain polishing solution (using the formula of Example 2, the difference being that sodium acetate was not added). S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the polishing liquid contained in the polishing tank through the polishing tank; then immerse the copper alloy precision thin-walled tube to be processed in the polishing liquid and polish it at 88°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0062] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tubes are shown in Table 9 below. Figure 10 As shown.

[0063] Table 9 Comparative Example 4: Gloss and Wall Thickness Reduction of Polished Copper Alloy Precision Thin-Walled Tubes

[0064] Comparative Example 5 S1. Use a low-concentration ammonium sulfate (inorganic single salt) with a mass fraction of 5.0% as the polishing solution; S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the polishing liquid contained in the polishing tank through the polishing tank; then immerse the copper alloy precision thin-walled tube to be processed in the polishing liquid and polish it at 88°C. S3. Post-processing: After polishing, remove the copper alloy precision thin-walled tube from the polishing solution, rinse it with water immediately, and quickly dry it to remove the moisture from the surface of the copper alloy precision thin-walled tube.

[0065] The gloss (GU) and wall thickness reduction (μm) of the polished copper alloy precision thin-walled tube are shown in Table 10 below.

[0066] Table 10 Comparative Example 5: Gloss and Wall Thickness Reduction of Polished Copper Alloy Precision Thin-Walled Tubes

[0067] It should be noted that in Examples 1-5 and Comparative Examples 1-5, a DC voltage of 300V was used, the polishing slurry temperature was controlled within the range of 85℃ to 90℃ (see the description of each example for details), and the total polishing time was 30s. The surface gloss was measured using the same material flat plate substitution method (initial value approximately 22 GU), and the average wall thickness reduction of the copper alloy thin tube was measured using the weighing method (initial thinning amount was 0 μm). Data was recorded every 5 seconds.

[0068] A systematic comparison of Examples 1-5 and Comparative Examples 1-5 reveals that the four components—sodium acetate, glycine, triethanolamine, and PEG-400—are indispensable and must work synergistically in the copper alloy thin-walled tube plasma liquid nanopolishing solution provided in this application. Sodium acetate provides the necessary conditions for conductive excitation (without it, polishing cannot be achieved, Comparative Example 4). Triethanolamine, as a protective agent, is the core component controlling the thinning rate and shape preservation (without it, the thinning amount increases from 2.05 μm to 10.80 μm in 30 seconds, and tip erosion becomes uncontrolled, Comparative Example 1). Glycine, as a complexing agent, is key to preventing oxidation (without it, the gloss level drops sharply from the peak to 30 GU after 15 seconds, and the surface turns black, Comparative Example 2). PEG-400... 400, as a leveling agent, is essential for improving the upper limit of gloss (without it, the gloss level can never exceed 100 GU, resulting in poor surface smoothness, as shown in Comparative Example 3). In contrast, the comparative scheme using a conventional inorganic salt system suffers wall thickness breakdown and becomes unusable within 20 seconds (Comparative Example 5). However, Example 2 (optimal formulation) can stably increase the gloss level from 21 GU to 126 GU within 30 seconds while precisely controlling the wall thickness reduction to 2.05 μm. This achieves the simultaneous attainment of four technical indicators: high-gloss surface, micron-level controllable removal, precision geometry preservation, and no oxidation discoloration. This fully demonstrates the significant superiority of this scheme in plasma polishing of copper alloy precision thin-walled tubes with beveled tips.

[0069] In summary, the plasma liquid nanopolishing slurry for copper alloy thin-walled tubes of this application effectively reduces the intensity of electrochemical reactions by using organic weak acid salts as the main salt to avoid local overheating. The use of amino acid complexing agents can effectively complex copper ions dissolved during the polishing process of copper alloy precision thin-walled tubes to prevent secondary hydrolysis and oxidation. The use of alkanolamine protective agents and polyether leveling agents can synergistically protect the tip microstructure and regulate the surface film formation, thereby achieving high-fidelity polishing of geometric shapes. It has the advantages of preventing excessive local melting of the beveled tip, precisely controlling the wall thickness reduction rate, and inhibiting copper ion oxidation to maintain a bright, oxide-free surface.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A copper alloy thin-walled tube plasma liquid nanopolishing slurry, characterized in that: For polishing precision thin-walled copper alloy tubes with beveled tips, the plasma liquid nanopolishing solution for copper alloy thin-walled tubes comprises the following functional components by total mass percentage: Main salt: 3.0%–4.5%, wherein the main salt is an organic weak acid salt; Complexing agent: 1.0%–1.5%, wherein the complexing agent is an amino acid compound; The protective agent is 0.5% to 1.0%, and the protective agent is an alcohol amine compound; The leveling agent is 0.5% to 1.0%, and the leveling agent is a polyether compound; The remainder is water; The total mass percentage of the main salt, complexing agent, protective agent, and leveling agent is controlled within the range of 5% to 8%.

2. The copper alloy thin-walled tube plasma liquid nanopolishing slurry according to claim 1, characterized in that, The main salt is sodium acetate, the complexing agent is glycine, the protective agent is triethanolamine, and the leveling agent is polyethylene glycol 400.

3. A polishing method, characterized in that: Polishing a precision thin-walled copper alloy tube with beveled tips includes the following steps: S1. Preparation of polishing slurry: Weigh 3.0% to 4.5% of main salt, 1.0% to 1.5% of complexing agent, 0.5% to 1.0% of protective agent, and 0.5% to 1.0% of leveling agent by mass percentage, add them to water and stir until completely dissolved to obtain a copper alloy thin-walled tube plasma liquid nanopolishing slurry with a total concentration of 5% to 8%. S2. Polishing: Connect the copper alloy precision thin-walled tube to be processed to the positive terminal of the power supply, and connect the negative terminal of the power supply to the copper alloy thin-walled tube plasma liquid nano-polishing liquid contained in the polishing tank through the polishing tank; and immerse the copper alloy precision thin-walled tube to be processed in the copper alloy thin-walled tube plasma liquid nano-polishing liquid for polishing. S3. Post-processing: After polishing, the copper alloy precision thin-walled tube is removed from the copper alloy thin-walled tube plasma liquid nano-polishing solution, immediately rinsed with water, and quickly dried to remove moisture from the surface of the copper alloy precision thin-walled tube.

4. The polishing method according to claim 3, characterized in that, In S1, the main salt is sodium acetate, the complexing agent is glycine, the protective agent is triethanolamine, and the leveling agent is polyethylene glycol 400.

5. The polishing method according to claim 3, characterized in that, In step S2, during the polishing process, the temperature of the copper alloy thin-walled tube plasma liquid nanopolishing solution is controlled to be 85~90℃.

6. The polishing method according to claim 3, characterized in that, In step S2, the voltage of the power supply is 300V; and the polishing time for a single polishing operation is 30±5s.

7. The polishing method according to claim 3, characterized in that, In step S3, the rapid drying specifically refers to drying at 80℃±5℃ for 5±0.5 min.

Images