Production process of aluminum oxide dispersion strengthened copper alloy pipe

Abstract

The invention relates to the technical field of metal pipe machining, in particular to a production process of an aluminum oxide dispersion strengthened copper alloy pipe. The titanium nitride coating is compact and stable, not only can the corrosion resistance of the copper alloy pipe be effectively improved, but also the wear resistance of the copper alloy pipe can be effectively improved, and the wear resistance of the copper alloy pipe can be further improved through mutual cooperation of the wear-resistant coating and the titanium nitride coating; furthermore, the microcapsule takes 19.6 Sn-31. 6Bi-48.8 In alloy as a core material and melamine modified urea-formaldehyde resin as a wall material, when the self-repairing layer is rubbed and heated and the local temperature of the self-repairing layer is too high, the microcapsule is broken, and the core material is melted to fill the damaged part, so that the self-repairing of the self-repairing layer is realized; the produced aluminum oxide dispersion strengthened copper alloy pipe has excellent wear resistance and outstanding oxidation resistance and corrosion resistance, the quality of the aluminum oxide dispersion strengthened copper alloy pipe is effectively guaranteed, and meanwhile the service life of the aluminum oxide dispersion strengthened copper alloy pipe is prolonged to a certain extent.

Description

Technical Field

[0001] This invention relates to the field of metal pipe processing technology, specifically to a production process for alumina dispersion-strengthened copper alloy pipes. Background Technology

[0002] Alumina dispersion-reinforced copper alloy tubes are widely used in electronic packaging, power transmission, and machinery manufacturing due to their excellent electrical conductivity, high strength, and superior thermal stability. However, in practical use, they face several challenges: the surface is prone to oxidation at high temperatures, reducing conductivity; in corrosive environments, the tube wall is easily eroded, leading to a decrease in strength; under mechanical friction conditions, surface wear is severe; and when minor surface damage occurs, the tube lacks self-repair capabilities, causing the damage to expand and increasing equipment maintenance costs and replacement frequency.

[0003] A manufacturing process for alumina dispersion-strengthened copper alloy tubes is disclosed in patent application number CN201910503369.7, belonging to the field of non-ferrous metal powder metallurgy materials. The specific method includes raw material preparation, cold isostatic pressing, pre-sintering, sintering, and hot isostatic pressing. The alumina dispersion-strengthened copper alloy tube comprises alumina and copper, with an alumina content of 0.10%-10.0% by mass, and the balance being copper. While the alumina dispersion-strengthened copper alloy tubes prepared in this patent possess advantages such as high strength, high conductivity, and excellent resistance to high-temperature softening, their wear resistance and corrosion resistance are relatively poor. This not only affects their quality but also shortens their service life to some extent. Therefore, this invention provides a manufacturing process for alumina dispersion-strengthened copper alloy tubes, aiming to solve the aforementioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide a production process for alumina dispersion-strengthened copper alloy tubes. The alumina dispersion-strengthened copper alloy tubes produced by this invention not only have excellent wear resistance but also outstanding oxidation resistance and corrosion resistance, effectively ensuring their quality and extending their service life to a certain extent.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A manufacturing process for alumina dispersion-strengthened copper alloy tubes includes the following steps:

[0007] Step 1: Add copper powder and ammoniated alumina together into a ball mill at a mass ratio of 10 to 18:1, and ball mill at a speed of 300 to 500 r / min for 12 to 24 hours under argon protection.

[0008] Step 2: After ball milling, heat the resulting mixed powder to 1200-1250℃, and then place it in an extrusion die with surrounding electromagnetic coils for electromagnetic extrusion molding. The resulting tube blank is then annealed and drawn, and then subjected to surface strengthening treatment by pulsed laser and plasma in sequence. The tube blank is annealed at 800-900℃ for 2-3 hours, and then drawn 3-5 times, with a diameter reduction of 10-15% each time.

[0009] Step 3: Pre-treat the tube blank after Step 2 by depositing a 1-1.5 μm thick titanium nitride coating on the surface of the tube blank using magnetron sputtering; then, spray a 0.4-0.7 mm thick wear-resistant coating and a 0.3-0.5 mm thick self-healing layer on the surface of the titanium nitride coating, and then perform thermosetting treatment.

[0010] The coating used in the self-healing layer is made by mixing microcapsules and adhesive in a mass ratio of 1:2 to 3; and the adhesive is made by mixing epoxy resin E-51, diethylenetriamine and acetone in a mass ratio of 100:8 to 12:12 to 18; the microcapsules use 19.6Sn-31.6Bi-48.8In alloy as the core material and melamine-modified urea-formaldehyde resin as the wall material.

[0011] Furthermore, the preparation method of the aminated alumina is as follows: γ-alumina with an average particle size of 10-15 nm is dispersed in an aqueous ethanol solution with a mass of 10-20 times that of γ-alumina and a volume concentration of 75-85%; then 10-20% by mass of 3-aminopropyltriethoxysilane is added, mixed well, and reacted at a temperature of 70-75°C for 10-15 h; after the reaction is completed, the product components are subjected to solid-liquid separation, alcohol washing, and drying treatment in sequence to obtain aminated alumina.

[0012] Furthermore, during electromagnetic extrusion molding, an alternating magnetic field of 35–45 Hz and 1.6–2.0 T is applied, the extrusion speed is 0.4–0.6 mm / s, the mold temperature is 520–560 ℃, and the extrusion pressure is 160–230 MPa.

[0013] Furthermore, when using pulsed lasers for enhancement, the process parameters are as follows: wavelength 1064–1070 nm, pulse frequency 10–50 kHz, pulse width 10–30 ns, and laser power density 2–6 GW / cm². 2 The scanning speed is 10–25 mm / s, and the scanning interval is 0.1–0.3 mm.

[0014] Furthermore, when plasma is used for enhancement, a mixture of Ar:H2 = 5 to 8:1 is used as the working gas, with a gas flow rate of 20 to 40 L / min, a voltage of 800 to 1200 V, and a time of 5 to 10 min.

[0015] Furthermore, the pretreatment process in step three is as follows: the tube blank is immersed in a 6-10 wt% hydrochloric acid solution for 15-20 minutes. After immersion, it is taken out, washed with water, and then ultrasonically cleaned with ethanol for 5-10 minutes. Finally, it is dried at a temperature of 105-115℃ for 90-120 minutes.

[0016] Furthermore, the method for preparing the microcapsules is as follows:

[0017] Step 1: Mix urea, melamine and aldehyde solution, adjust the pH to 8.5-9.5 with triethanolamine, and then keep the mixture at 65-75℃ and stir for 2-3 hours to obtain resin prepolymer; wherein, the aldehyde solution is a 37wt% formaldehyde aqueous solution; the molar ratio of urea, melamine and formaldehyde is 3-5:1-3:5-7.

[0018] The second step involves placing the metals in a crucible at a mass ratio of Sn:Bi:In = 19.6:31.6:48.8, heating them to 150–180°C under nitrogen protection to melt them, stirring at a rate of 300–400 r / min while providing ultrasonic assistance at a frequency of 20–25 kHz for 30–40 s; then using a gas atomization method to prepare the resulting melt into a core material with an average particle size of 15–30 μm.

[0019] The third step involves immersing the core material in a 3-5 wt% polyvinyl alcohol aqueous solution, which is 4-6 times its weight. After emulsification, resin prepolymer is added dropwise at a rate of 2-3 mL / min. After mixing, the pH of the resulting mixed phase is adjusted to 3.5-4.5 with a 10-15 wt% ammonium chloride aqueous solution. The mixture is then reacted at 50-60°C for 4-6 hours. After the reaction is complete, the product components are subjected to solid-liquid separation, washing, and drying to obtain microcapsules.

[0020] Furthermore, in the preparation of the titanium nitride coating, titanium target material and nitrogen gas are used as reactant gases, under a vacuum of 1×10⁻⁶. -4 ~1×10 -3 Sputtering was performed for 45–55 minutes at Pa, argon flow rate of 18–25 sccm, nitrogen flow rate of 8–12 sccm, sputtering power of 160–200 W, and temperature of 220–280 °C.

[0021] Furthermore, the method for preparing the wear-resistant coating is as follows: WC-Co powder with a WC mass fraction of 90-92% is sprayed onto the titanium nitride coating using a supersonic flame spraying method. Before spraying, the tube blank is heated to 230-270℃. The spraying distance is 110-130mm and the spraying speed is 7-9m / min.

[0022] Furthermore, the thermosetting treatment is performed at a pressure of 0.7–0.9 MPa, a temperature of 70–80 °C, and a treatment time of 20–30 min.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] The functional groups at one end of 3-aminopropyltriethoxysilane react with the hydroxyl groups on the alumina surface, while the functional groups at the other end can chemically react with the copper alloy matrix, thereby enhancing the bonding force between the alumina particles and the copper alloy matrix. The confinement field formed by electromagnetic force effectively controls the flow direction and speed of the semi-solid alloy, promoting the uniform distribution of nano-alumina particles, refining the grain size, and improving the density and forming accuracy of the alloy tube, thus ensuring the quality of the produced copper alloy tube. The prepared tube blank is then subjected to annealing and drawing treatments, followed by sequential pulsed laser and plasma surface strengthening treatments to further refine the grain size and enhance the interfacial bonding strength.

[0025] After pretreatment and surface cleaning, a titanium nitride coating, a wear-resistant coating, and a self-healing coating are sequentially deposited on the tube blank surface. The dense and stable titanium nitride coating effectively improves both the corrosion resistance and wear resistance of the copper alloy tube. The synergistic effect of the wear-resistant coating and the titanium nitride coating further enhances the wear resistance of the copper alloy tube. Furthermore, the microcapsules use a 19.6Sn-31.6Bi-48.8In alloy as the core material and melamine-modified urea-formaldehyde resin as the wall material. When the self-healing layer experiences frictional heating leading to excessively high local temperatures or external mechanical damage causing the microcapsules to rupture, the core material melts and fills the damaged area, achieving self-healing of the self-healing layer. After curing, the epoxy resin forms a dense polymer film that blocks oxygen, water vapor, and corrosive media. Its stable molecular structure resists chemical erosion. After hot pressing, the adhesive penetrates the pores of the wear-resistant coating to form a mechanical bond. Temperature promotes the full cross-linking of epoxy resin and curing agent, enhancing the bonding force of the self-healing layer and reducing the chance of it falling off.

[0026] In summary, the alumina dispersion reinforced copper alloy tube produced by this invention not only has excellent wear resistance but also outstanding oxidation resistance and corrosion resistance, effectively ensuring its quality and extending its service life to a certain extent. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] A manufacturing process for alumina dispersion-strengthened copper alloy tubes includes the following steps:

[0030] Step 1: Add copper powder and ammoniated alumina together into a ball mill at a mass ratio of 10:1 and ball mill at a speed of 300 r / min for 24 hours under argon protection.

[0031] Step 2: After ball milling, heat the resulting mixed powder to 1200℃, and then place it in an extrusion mold with electromagnetic coils around it for electromagnetic extrusion molding. The resulting tube blank is then annealed and drawn, and then subjected to surface strengthening treatment by pulsed laser and plasma in sequence. The tube blank is annealed at 800℃ for 3 hours, and then drawn 3 times, with a diameter reduction of 10% each time.

[0032] Step 3: Pre-treat the tube blank after Step 2 by depositing a 1μm thick titanium nitride coating on its surface using magnetron sputtering. Then, sequentially spray a 0.4mm thick wear-resistant coating and a 0.3mm thick self-healing layer onto the surface of the titanium nitride coating, followed by thermosetting treatment. The thermosetting treatment pressure is 0.7MPa, the temperature is 70℃, and the treatment time is 20min.

[0033] The coating used in the self-healing layer is made by mixing microcapsules and adhesive in a mass ratio of 1:2; the adhesive is made by mixing epoxy resin E-51, diethylenetriamine and acetone in a mass ratio of 100:8:12; the microcapsules use 19.6Sn-31.6Bi-48.8In alloy as the core material and melamine-modified urea-formaldehyde resin as the wall material.

[0034] The preparation method of aminated alumina is as follows: γ-alumina with an average particle size of 10 nm is dispersed in an aqueous ethanol solution with a volume concentration of 75% and a mass of 10 times that of γ-alumina; then 3-aminopropyltriethoxysilane with a mass of 10% of γ-alumina is added, mixed well, and reacted at 70°C for 10 h; after the reaction is completed, the product components are subjected to solid-liquid separation, alcohol washing, and drying treatment in sequence to obtain aminated alumina.

[0035] During electromagnetic extrusion molding, an alternating magnetic field of 35Hz and 1.6T is applied, the extrusion speed is 0.4mm / s, the mold temperature is 520℃, and the extrusion pressure is 160MPa.

[0036] When using pulsed laser for enhancement, the process parameters are as follows: wavelength 1064nm, pulse frequency 10kHz, pulse width 10ns, and laser power density 2GW / cm². 2 The scanning speed is 10 mm / s and the scanning interval is 0.1 mm.

[0037] When plasma enhancement is used, a mixture of Ar:H2 = 5:1 is used as the working gas, the gas flow rate is 20L / min, the voltage is 800V, and the time is 5min.

[0038] The pretreatment process in step three is as follows: immerse the tube blank in a 6wt% hydrochloric acid solution for 15 minutes. After immersion, take it out, wash it with water, and then ultrasonically clean it with ethanol for 5 minutes. Finally, dry it at 105℃ for 90 minutes.

[0039] The preparation method of microcapsules is as follows:

[0040] Step 1: Mix urea, melamine and aldehyde solution, adjust the pH to 8.5 with triethanolamine, and then keep the mixture at 65°C with stirring for 3 hours to obtain resin prepolymer; wherein, the aldehyde solution is a 37wt% formaldehyde aqueous solution; the molar ratio of urea, melamine and formaldehyde is 3:1:5.

[0041] The second step involves placing the metals in a crucible at a mass ratio of Sn:Bi:In = 19.6:31.6:48.8, heating them to 150°C under nitrogen protection to melt them, stirring at 300 r / min while ultrasonically assisted at 20 kHz for 40 s; then using a gas atomization method to prepare the resulting melt into a core material with an average particle size of 20 μm.

[0042] The third step involves immersing the core material in a 3wt% polyvinyl alcohol aqueous solution, four times its weight. After emulsification, resin prepolymer is added dropwise at a rate of 2 mL / min. After mixing, the pH of the resulting mixed phase is adjusted to 3.5 using a 10wt% ammonium chloride aqueous solution. The mixture is then reacted at 50°C for 6 hours. Once the reaction is complete, the product components are subjected to solid-liquid separation, washing, and drying to obtain microcapsules.

[0043] In the preparation of titanium nitride coatings, titanium target material and nitrogen gas were used as reaction gases, under a vacuum of 1×10⁻⁶. -4 Sputtering was performed for 45 minutes at a temperature of 220℃ and an argon flow rate of 18 sccm, a nitrogen flow rate of 8 sccm, a sputtering power of 160 W, and a sputtering temperature of 220℃.

[0044] The method for preparing the wear-resistant coating is as follows: WC-Co powder with a WC mass fraction of 90% is sprayed onto the titanium nitride coating by supersonic flame spraying. The tube blank is heated to 230℃ before spraying. The spraying distance is 110mm and the spraying speed is 7m / min.

[0045] Example 2

[0046] The manufacturing process of the alumina dispersion-reinforced copper alloy tube provided in this embodiment is basically the same as that in Embodiment 1, except that the specific composition of the coating used in the self-healing layer and the preparation method of the microcapsules are not exactly the same. The specific composition of the coating used in the self-healing layer and the preparation method of the microcapsules in this embodiment are as follows:

[0047] The coating used in the self-healing layer is made by mixing microcapsules and adhesive in a mass ratio of 1:2.5; and the adhesive is made by mixing epoxy resin E-51, diethylenetriamine and acetone in a mass ratio of 100:10:15.

[0048] The preparation method of microcapsules is as follows:

[0049] Step 1: Mix urea, melamine and aldehyde solution, adjust the pH to 9 with triethanolamine, and then keep the mixture at 70°C with stirring for 3 hours to obtain resin prepolymer; wherein, the aldehyde solution is a 37wt% formaldehyde aqueous solution; the molar ratio of urea, melamine and formaldehyde is 4:2:6.

[0050] The second step is to place the metals into a crucible according to the mass ratio of Sn:Bi:In = 19.6:31.6:48.8, heat it to 170°C under nitrogen protection to melt it, and stir it at a rate of 350 r / min while ultrasonically assisting it at a frequency of 25 kHz for 35 seconds.

[0051] The third step involves immersing the core material in a 4 wt% polyvinyl alcohol aqueous solution, five times its weight. After emulsification, resin prepolymer is added dropwise at a rate of 3 mL / min. After mixing, the pH of the resulting mixed phase is adjusted to 4 using a 15 wt% ammonium chloride aqueous solution. The mixture is then reacted at 50–60 °C for 5 hours. Once the reaction is complete, the product components are subjected to solid-liquid separation, washing, and drying to obtain microcapsules.

[0052] Example 3

[0053] The manufacturing process of the alumina dispersion-reinforced copper alloy tube provided in this embodiment is basically the same as that in Embodiment 1, except that the specific composition of the coating used in the self-healing layer and the preparation method of the microcapsules are not exactly the same. The specific composition of the coating used in the self-healing layer and the preparation method of the microcapsules in this embodiment are as follows:

[0054] The coating used in the self-healing layer is made by mixing microcapsules and adhesive in a mass ratio of 1:3; and the adhesive is made by mixing epoxy resin E-51, diethylenetriamine and acetone in a mass ratio of 100:12:18.

[0055] The preparation method of microcapsules is as follows:

[0056] Step 1: Mix urea, melamine and aldehyde solution, adjust the pH to 9.5 with triethanolamine, and then keep the mixture at 75°C with stirring for 2 hours to obtain resin prepolymer; wherein, the aldehyde solution is a 37wt% formaldehyde aqueous solution; the molar ratio of urea, melamine and formaldehyde is 5:3:7.

[0057] The second step is to place the metals into a crucible according to the mass ratio of Sn:Bi:In = 19.6:31.6:48.8, heat them to 180°C under nitrogen protection to melt them, and stir them at a rate of 400 r / min while ultrasonically assisted at a frequency of 25 kHz for 40 seconds.

[0058] The third step involves immersing the core material in a 5 wt% polyvinyl alcohol aqueous solution, which is six times its weight. After emulsification, resin prepolymer is added dropwise at a rate of 3 mL / min. After mixing, the pH of the resulting mixed phase is adjusted to 4.5 using a 15 wt% ammonium chloride aqueous solution. The mixture is then reacted at 60°C for 4 hours. After the reaction is complete, the product components are subjected to solid-liquid separation, washing, and drying to obtain microcapsules.

[0059] The difference between Comparative Example 1 and Example 1 is that the preparation steps of the titanium nitride coating are omitted in this comparative example.

[0060] The difference between Comparative Example 2 and Example 1 is that the preparation steps of the wear-resistant coating are omitted in this comparative example.

[0061] Comparative Example 3 differs from Example 1 in that the preparation step of the self-healing layer is omitted in this comparative example.

[0062] Test methods and data

[0063] I. Testing Methods

[0064] 1. Antioxidant performance test: The alloy tube was placed in a muffle furnace and held at 300℃ for 100 hours. The mass change before and after oxidation was measured using an electronic balance with an accuracy of 0.0001g, and the weight gain due to oxidation (mg / cm³) was calculated. 2 ).

[0065] 2. Wear life test: The test was conducted according to ASTM G75 standard. The test conditions were: 130N load, SiO2 abrasive slurry, and the failure criterion was matrix exposure.

[0066] 3. Self-healing performance test: Use a tool to create a scratch 0.2 mm wide and 0.1 mm deep on the sample surface, place it at 80℃ for 2 hours, observe the scratch with a laser confocal microscope, and calculate the repair area percentage (%). The higher the percentage, the better the self-healing performance.

[0067] 4. Corrosion resistance test: Referring to GB / T 10125-2021 standard for salt spray test of artificial atmosphere corrosion test, the alloy tube is placed in a salt spray chamber with 5wt% sodium chloride solution at 35℃ and sprayed continuously for 240h. The surface corrosion is observed and the corrosion weight loss rate is measured.

[0068] II. Test Data

[0069]

[0070] By comparing and analyzing the relevant data in the table, it can be seen that the alumina dispersion-strengthened copper alloy tube produced by this invention not only has excellent wear resistance but also outstanding oxidation resistance and corrosion resistance, effectively ensuring its quality and extending its service life to a certain extent. This indicates that the production process of the alumina dispersion-strengthened copper alloy tube provided by this invention has a broader market prospect and is more suitable for widespread application.

[0071] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A manufacturing process for an alumina dispersion-strengthened copper alloy tube, characterized in that, Includes the following steps: Step 1: Add copper powder and ammoniated alumina together into a ball mill at a mass ratio of 10 to 18:1, and ball mill at a speed of 300 to 500 r / min for 12 to 24 hours under argon protection. Step 2: After ball milling, heat the resulting mixed powder to 1200-1250℃, and then place it in an extrusion mold with electromagnetic coils around it for electromagnetic extrusion molding. The resulting tube blank is then annealed and drawn, and then subjected to surface strengthening treatment by pulsed laser and plasma in sequence. Step 3: Pre-treat the tube blank after Step 2 by depositing a 1-1.5 μm thick titanium nitride coating on the surface of the tube blank using magnetron sputtering. Then, a 0.4-0.7 mm thick wear-resistant coating and a 0.3-0.5 mm thick self-healing layer are sequentially sprayed onto the surface of the titanium nitride coating, followed by thermosetting treatment. The coating used in the self-healing layer is made by mixing microcapsules and adhesive in a mass ratio of 1:2 to 3; and the adhesive is made by mixing epoxy resin E-51, diethylenetriamine and acetone in a mass ratio of 100:8 to 12:12 to 18; the microcapsules use 19.6Sn-31.6Bi-48.8In alloy as the core material and melamine-modified urea-formaldehyde resin as the wall material.

2. The manufacturing process of an alumina dispersion-strengthened copper alloy tube according to claim 1, characterized in that, The preparation method of the aminated alumina is as follows: γ-alumina with an average particle size of 10-15 nm is dispersed in an aqueous ethanol solution with a volume concentration of 75-85% and a mass ratio of 10-20 times that of γ-alumina; then 10-20% by mass of 3-aminopropyltriethoxysilane is added, and after mixing, the mixture is reacted at a temperature of 70-75°C for 10-15 h; after the reaction is completed, the product components are subjected to solid-liquid separation, alcohol washing and drying treatment in sequence to obtain aminated alumina.

3. The manufacturing process of an alumina dispersion-strengthened copper alloy tube according to claim 1, characterized in that: During electromagnetic extrusion molding, an alternating magnetic field of 35–45 Hz and 1.6–2.0 T is applied, the extrusion speed is 0.4–0.6 mm / s, the die temperature is 520–560 ℃, and the extrusion pressure is 160–230 MPa.

4. The manufacturing process of an alumina dispersion-strengthened copper alloy tube according to claim 1, characterized in that, When using pulsed laser for enhancement, the process parameters are as follows: wavelength 1064–1070 nm, pulse frequency 10–50 kHz, pulse width 10–30 ns, and laser power density 2–6 GW / cm². 2 The scanning speed is 10–25 mm / s, and the scanning interval is 0.1–0.3 mm.

5. The manufacturing process of an alumina dispersion-strengthened copper alloy tube according to claim 1, characterized in that: When plasma is used for enhancement, a mixture of Ar:H2 = 5 to 8:1 is used as the working gas, with a gas flow rate of 20 to 40 L / min, a voltage of 800 to 1200 V, and a time of 5 to 10 min.

6. The manufacturing process of an alumina dispersion-strengthened copper alloy tube according to claim 1, characterized in that, The pretreatment process in step three is as follows: immerse the tube blank in a 6-10 wt% hydrochloric acid solution for 15-20 minutes. After immersion, remove it, wash it with water, and then ultrasonically clean it with ethanol for 5-10 minutes. Finally, dry it at a temperature of 105-115℃ for 90-120 minutes.

7. The manufacturing process of an alumina dispersion-strengthened copper alloy tube according to claim 1, characterized in that, The microcapsules are prepared by: Step 1: Mix urea, melamine and aldehyde solution, adjust the pH to 8.5-9.5 with triethanolamine, and then keep the mixture at 65-75℃ and stir for 2-3 hours to obtain resin prepolymer; wherein, the aldehyde solution is a 37wt% formaldehyde aqueous solution; the molar ratio of urea, melamine and formaldehyde is 3-5:1-3:5-7. The second step involves placing the metals in a crucible at a mass ratio of Sn:Bi:In = 19.6:31.6:48.8, heating them to 150–180°C under nitrogen protection to melt them, stirring at a rate of 300–400 r / min while providing ultrasonic assistance at a frequency of 20–25 kHz for 30–40 s; then using a gas atomization method to prepare the resulting melt into a core material with an average particle size of 15–30 μm. The third step involves immersing the core material in a 3-5 wt% polyvinyl alcohol aqueous solution, which is 4-6 times its weight. After emulsification, resin prepolymer is added dropwise at a rate of 2-3 mL / min. After mixing, the pH of the resulting mixed phase is adjusted to 3.5-4.5 with a 10-15 wt% ammonium chloride aqueous solution. The mixture is then reacted at 50-60°C for 4-6 hours. After the reaction is complete, the product components are subjected to solid-liquid separation, washing, and drying to obtain microcapsules.

8. The manufacturing process of an alumina dispersion-strengthened copper alloy tube according to claim 1, characterized in that, In the preparation of titanium nitride coatings, titanium target material and nitrogen gas were used as reaction gases, under a vacuum of 1×10⁻⁶. -4 ~1×10 -3 Sputtering was performed for 45–55 minutes at Pa, argon flow rate of 18–25 sccm, nitrogen flow rate of 8–12 sccm, sputtering power of 160–200 W, and temperature of 220–280 °C.

9. The manufacturing process of an alumina dispersion-strengthened copper alloy tube according to claim 1, characterized in that, The method for preparing the wear-resistant coating is as follows: WC-Co powder with a WC mass fraction of 90-92% is sprayed onto the titanium nitride coating using a supersonic flame spraying method. Before spraying, the tube blank is heated to 230-270℃. The spraying distance is 110-130mm and the spraying speed is 7-9m / min.

10. The manufacturing process of an alumina dispersion-strengthened copper alloy tube according to claim 1, characterized in that: The thermosetting treatment is performed at a pressure of 0.7–0.9 MPa, a temperature of 70–80 °C, and a treatment time of 20–30 min.

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