Electrolyte, application of electrolyte, copper-doped micro-arc oxidation film and preparation method of copper-doped micro-arc oxidation film

Abstract

The invention belongs to the technical field of alloy surface modification, and particularly relates to an electrolyte and application thereof, a copper-doped micro-arc oxidation film and a preparation method of the copper-doped micro-arc oxidation film. The invention provides an electrolyte. The electrolyte comprises a composite copper source, a film-forming agent, a surfactant, a pH value regulator and water, the composite copper source comprises soluble copper salt and sodium copper chlorophyllin. The chlorophyll copper complex ions and the copper ions are used as composite copper sources in the electrolyte, and the copper-doped micro-arc oxidation film formed by performing micro-arc oxidation on the chlorophyll copper complex ions and the copper ions has relatively high copper doping amount, so that the corrosion resistance and the antifouling property of the oxidation film are improved. And meanwhile, the working window is expanded when the electrolyte is used for micro-arc oxidation, and industrial application is facilitated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of alloy surface modification, and particularly relates to an electrolyte and application thereof, a copper-doped micro-arc oxidation film and a preparation method. BACKGROUND

[0002] In the through-sea pipeline system, titanium and its alloys have become the ideal material for key components such as pipelines, valves and their accessories due to their high specific strength, excellent corrosion resistance and lightweight characteristics. However, the harshness of the marine environment poses multiple challenges to titanium-based components: high-salinity seawater can easily damage the passivation film, inducing pitting and crevice corrosion; high-speed sand-laden water flow exacerbates erosion and wear; microorganisms such as bacteria, barnacles and algae are prone to adhere to the surface of titanium-based components, not only increasing the flow resistance and leading to pipeline blockage, but also forming an oxygen concentration cell and breeding sulfate-reducing bacteria (SRB), which can accelerate microbial corrosion. In addition, when titanium with a high potential (+0.15~+0.4V) is connected to low-potential metals (such as steel and aluminum), galvanic corrosion is easily induced.

[0003] At present, how to improve the corrosion resistance and antifouling performance of titanium-based components is a technical problem that needs to be solved. SUMMARY

[0004] Therefore, the application provides an electrolyte and application thereof, a copper-doped micro-arc oxidation film and a preparation method. The titanium alloy is subjected to micro-arc oxidation using the electrolyte provided by the application, so that a copper-doped micro-arc oxidation film with a high copper doping amount can be formed. The copper-doped micro-arc oxidation film has good corrosion resistance and antifouling performance, and can improve the service life of titanium-based alloys in marine environments.

[0005] To solve the above technical problems, the application provides an electrolyte, which comprises a composite copper source, a film-forming agent, a surfactant, a pH value regulator and water. The composite copper source comprises a soluble copper salt and sodium copper chlorophyll.

[0006] Preferably, the soluble copper salt comprises one or more of copper chloride, copper sulfate and copper nitrate. The molar ratio of the soluble copper salt to sodium copper chlorophyll is less than or equal to 4:1. The film-forming agent comprises sodium silicate, a phosphate or a meta-aluminate.

[0007] Preferably, the molar concentration of copper ions in the electrolyte is 0.1mol / L or less, the molar concentration of sodium copper chlorophyll is 0.005~0.045mol / L, the molar concentration of the film-forming agent is 0.05~0.2mol / L, and the molar concentration of the surfactant is 0.005~0.02mol / L.

[0008] Preferably, the surface active agent comprises sodium dodecyl sulfate, sodium dodecyl benzene sulfonate or sodium oleate. The pH regulator comprises a sodium hydroxide solution and / or a potassium hydroxide solution; the pH of the electrolyte is 8-11.

[0009] The application provides application of the electrolyte in preparation of a copper-doped micro-arc oxidation film.

[0010] The application further provides a preparation method of the copper-doped micro-arc oxidation film, comprising the following steps: The alloy substrate is used as an anode, and an inert electrode is used as a cathode to perform micro-arc oxidation, so as to form a copper-doped micro-arc oxidation film on the surface of the alloy substrate; the electrolyte for micro-arc oxidation is the electrolyte according to the above technical solution.

[0011] Preferably, the parameters of the micro-arc oxidation comprise: a constant current mode, a current density of 0.05-2.20 A / cm 2 , a working frequency of 100-2000 Hz, a distance between the anode and the cathode of 3-20 cm, a duty cycle of 5-40%, a processing time of 5-40 min, and a temperature of 10-30 DEG C. The micro-arc oxidation process is accompanied by ultrasonic assistance.

[0012] Preferably, the alloy substrate comprises pure titanium or a titanium alloy. The titanium alloy comprises TA1 titanium alloy, TA2 titanium alloy, TA3 titanium alloy, TC4 titanium alloy, Ti-Ni alloy, Ti-2Al-2.5Zr titanium alloy, Ti-32Mo titanium alloy or Ti-Mo-Ni titanium alloy. The inert electrode comprises a platinum sheet, graphite or stainless steel.

[0013] Preferably, when the alloy substrate is TC4 titanium alloy, the electrolyte for micro-arc oxidation comprises 0.12 mol / L sodium silicate, 0.04 mol / L copper sodium chlorophyll, 0.08 mol / L copper sulfate and 0.015 mol / L sodium dodecyl sulfate, and the pH of the electrolyte is 9.5-10.5. When the alloy substrate is TA1 titanium alloy, the electrolyte for micro-arc oxidation comprises 0.08 mol / L sodium silicate, 0.01 mol / L copper sodium chlorophyll, 0.01 mol / L copper sulfate and 0.005 mol / L sodium dodecyl sulfate, and the pH of the electrolyte is 9.5-10.5. When the alloy substrate is TA3 titanium alloy, the electrolyte for micro-arc oxidation comprises 0.1 mol / L sodium silicate, 0.02 mol / L copper sodium chlorophyll, 0.08 mol / L copper sulfate and 0.01 mol / L sodium dodecyl sulfate, and the pH of the electrolyte is 9.5-10.5.

[0014] The application further provides the copper-doped micro-arc oxidation film prepared by the preparation method.

[0015] The application provides an electrolyte, which comprises a composite copper source, a film forming agent, a surfactant, a pH value regulator and water; the composite copper source comprises a soluble copper salt and sodium copper chlorophyll. The copper-doped micro-arc oxidation film formed by the electrolyte has a high copper doping amount, so that the corrosion resistance and the antifouling performance of the oxidation film are improved. Meanwhile, the electrolyte provided by the application expands the working window of the micro-arc oxidation, which is beneficial to industrial application. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a schematic diagram of the micro-arc oxidation of the titanium-based workpiece as an anode and the copper ion and the sodium copper chlorophyll as the composite copper source (electrolyte) in the embodiments of the application, wherein the Cu-rich film layer is the copper-doped micro-arc oxidation film; Figure 2 It is an SEM image of the copper-doped micro-arc oxidation film in Example 1; Figure 3 It is an SEM image of the copper-doped micro-arc oxidation film in Example 2; Figure 4 It is an SEM image of the copper-doped micro-arc oxidation film in Example 3; Figure 5 It is a columnar comparison diagram of the copper content in the micro-arc oxidation films of Example 1 and Comparative Examples 1-5; Figure 6 It is a columnar comparison diagram of the copper content in the micro-arc oxidation films of Example 2 and Comparative Examples 6-10; Figure 7 It is a columnar comparison diagram of the copper content in the micro-arc oxidation films of Example 3 and Comparative Examples 11-15; Figure 8 It is a columnar comparison diagram of the low-frequency impedance modulus of the micro-arc oxidation films of Example 1 and Comparative Examples 1-5; Figure 9 It is a columnar comparison diagram of the low-frequency impedance modulus of the micro-arc oxidation films of Example 2 and Comparative Examples 6-10; Figure 10 It is a columnar comparison diagram of the low-frequency impedance modulus of the micro-arc oxidation films of Example 3 and Comparative Examples 11-15; Figure 11 It is a columnar comparison diagram of the antibacterial rate of the micro-arc oxidation films of Example 1 and Comparative Examples 1-5; Figure 12 It is a columnar comparison diagram of the antibacterial rate of the micro-arc oxidation films of Example 2 and Comparative Examples 6-10; Figure 13 A columnar contrast chart of the antibacterial rate of the micro-arc oxidation film of Example 3 and Comparative Examples 11-15. DETAILED DESCRIPTION

[0017] The present application provides an electrolyte, comprising a composite copper source, a film forming agent, a surfactant, a pH adjuster and water.

[0018] In the present application, the composite copper source comprises a soluble copper salt and sodium copper chlorophyllin; the soluble copper salt can comprise one or more of copper chloride, copper sulfate and copper nitrate, and can specifically be copper chloride, copper sulfate or copper nitrate; the molar ratio of the soluble copper salt and sodium copper chlorophyllin (SCC) can be less than or equal to 4:1, and can specifically be 4:1, 3.5:1, 3:1, 2:1, 1:1 or 0.5:1.

[0019] As a specific embodiment of the present application, the molar concentration of copper ions in the electrolyte can be 0.1 mol / L or less, and can specifically be 0.01 mol / L, 0.03 mol / L, 0.05 mol / L or 0.08 mol / L; the molar concentration of sodium copper chlorophyllin in the electrolyte can be 0.005-0.045 mol / L, and can specifically be 0.01 mol / L, 0.02 mol / L, 0.03 mol / L or 0.04 mol / L; the film forming agent can comprise sodium silicate, a phosphate or a meta-aluminate, the phosphate can be monosodium phosphate, disodium phosphate, monopotassium phosphate or dipotassium phosphate, and the meta-aluminate can be sodium meta-aluminate or potassium meta-aluminate; the molar concentration of the film forming agent in the electrolyte can be 0.05-0.2 mol / L, and can specifically be 0.08 mol / L, 0.1 mol / L, 0.12 mol / L or 0.18 mol / L; the molar concentration of sodium dodecyl sulfonate in the electrolyte can be 0.005-0.02 mol / L, and can specifically be 0.01 mol / L or 0.015 mol / L.

[0020] As a specific embodiment of the present application, the surfactant can comprise sodium dodecyl sulfate, sodium dodecyl benzene sulfonate or sodium oleate. In the present application, the surfactant can improve the solution stability and interfacial stability of the electrolyte.

[0021] As a specific embodiment of the present application, the pH adjuster can comprise a sodium hydroxide solution and / or a potassium hydroxide solution, and can specifically be a sodium hydroxide solution or a potassium hydroxide solution; the mass concentration of the pH adjuster can be 4-6 g / L, and can specifically be 5 g / L.

[0022] As a specific embodiment of the present application, the pH value of the electrolyte can be 8-11, which can be specifically 8, 8.5, 9, 9.5, 10 or 10.5. The present application does not have special requirements for the amount of the pH value regulator, as long as the pH value of the electrolyte can reach the required value.

[0023] As a specific embodiment of the present application, the water can be high-purity water or deionized water.

[0024] As a specific embodiment of the present application, the preparation method of the electrolyte can include the following steps: mixing soluble copper salt, sodium copper chlorophyll, film-forming agent, surfactant, pH value regulator and water to obtain the electrolyte; the mixing can be carried out under the condition of magnetic stirring.

[0025] The present application also provides the application of the electrolyte in the preparation of copper-doped micro-arc oxidation film.

[0026] The present application also provides a preparation method of copper-doped micro-arc oxidation film, which includes the following steps: The alloy substrate is used as an anode, and the inert electrode is used as a cathode to carry out micro-arc oxidation to form a copper-doped micro-arc oxidation film on the surface of the alloy substrate; the electrolyte for micro-arc oxidation is the electrolyte described in the above technical solution.

[0027] As a specific embodiment of the present application, the micro-arc oxidation can further include pretreating the alloy substrate; the pretreatment includes the following steps: cleaning the alloy substrate, then polishing, acetone washing and drying once, and coating the dried sample with insulating tape, and the surface outside the coating is the surface for micro-arc oxidation. The present application can remove the oil stains on the surface of the alloy substrate by cleaning, and the present application does not have special requirements for the cleaning, which can be carried out in a conventional manner in the art. As a specific embodiment of the present application, the polishing can be step-by-step polishing with 600#, 1000#, 1500# and 2000# sandpaper; the present application does not have special limitations for the acetone washing, drying and coating, which can be carried out in a conventional manner in the art.

[0028] As a specific embodiment of the present application, the alloy substrate can include pure titanium or titanium alloy; the titanium alloy can include TA1 titanium alloy, TA2 titanium alloy, TA3 titanium alloy, TC4 titanium alloy, Ti-Ni alloy, Ti-2Al-2.5Zr titanium alloy, Ti-32Mo titanium alloy or Ti-Mo-Ni titanium alloy; the inert electrode includes platinum sheet, graphite or stainless steel.

[0029] As a specific embodiment of the present application, when the alloy base is TC4 titanium alloy, the composition of the electrolyte for micro-arc oxidation can be 0.12 mol / L sodium silicate, 0.04 mol / L sodium copper chlorophyll, 0.08 mol / L copper sulfate, and 0.015 mol / L sodium dodecyl sulfate, and the pH value of the electrolyte is 9.5-10.5; when the alloy base is TA1 titanium alloy, the composition of the electrolyte for micro-arc oxidation can be 0.08 mol / L sodium silicate, 0.01 mol / L sodium copper chlorophyll, 0.01 mol / L copper sulfate, and 0.005 mol / L sodium dodecyl sulfate, and the pH value of the electrolyte is 9.5-10.5; when the alloy base is TA3 titanium alloy, the composition of the electrolyte for micro-arc oxidation can be 0.1 mol / L sodium silicate, 0.02 mol / L sodium copper chlorophyll, 0.08 mol / L copper sulfate, and 0.01 mol / L sodium dodecyl sulfate, and the pH value of the electrolyte is 9.5-10.5. The pH value of the electrolyte can be maintained by adding a pH value adjusting agent dropwise.

[0030] As a specific embodiment of the present application, the micro-arc oxidation can further comprise sequentially performing oil removal treatment, polishing treatment, cleaning treatment, and drying treatment on the alloy base. The present application does not have special requirements for the oil removal treatment, polishing treatment, cleaning treatment, and drying treatment, and the treatment can be performed in a conventional manner in the art; in the present application, the polishing treatment can be performed by using sandpaper to polish step by step, and the cleaning treatment can be performed by using acetone.

[0031] As a specific embodiment of the present application, the parameters of the micro-arc oxidation can include: a constant current mode, a current density of 0.05-2.20 A / cm 2 , a working frequency of 100-2000 Hz, a distance between the anode and the cathode of 3-20 cm, a current density of 0.05-2.20 A / cm 2 , a duty cycle of 5-40%, a treatment time of 5-40 min, and a temperature of 10-30°C; or a constant current mode, a current density of 0.08-0.12 A / cm 2 , a working frequency of 600-1000 Hz, a distance between the anode and the cathode of 6-12 cm, a duty cycle of 10-20%, a treatment time of 8-20 min, and a temperature of 15-25°C. The present application performs micro-arc oxidation under a constant current condition, and the micro-arc oxidation at a lower temperature can ensure the stability of the sodium copper chlorophyll.

[0032] As a specific embodiment of the present application, the micro-arc oxidation process can be accompanied by ultrasonic assistance, the frequency of the ultrasonic assistance can be 45-55 kHz, and can be specifically 50 kHz; the power of the ultrasonic assistance can be 150-250 W, and can be specifically 200 W. The present application can promote the convection of the solution during the micro-arc oxidation process, ensure the enrichment of Cu in the electrolyte near the anode surface, that is, after the SCC is consumed, the replenishment is carried out in time (mechanical effect), and at the same time, defects are introduced into the surface passivation film to promote the arcing effect (cavitation effect); thereby the thickness and compactness of the film layer can be improved. The present application selects the electro-attractive effect of the negatively charged copper chlorophyll complex ion on the positively charged copper ion to form a composite copper source, the alloy substrate is micro-arc oxidized as the anode, the inert electrode is micro-arc oxidized as the cathode, and the external ultrasonic assistance is added during the micro-arc oxidation process. Through the electromigration of the external electric field and the convection effect of the ultrasonic field, the directional migration of the copper ion to the surface of the alloy substrate is promoted, the content of copper on the surface of the alloy substrate is greatly improved, the mass percentage of copper in the film layer is improved, and the corrosion resistance and antifouling performance of the film layer are improved.

[0033] Figure 1 A schematic diagram of the micro-arc oxidation of a titanium alloy workpiece as an anode with copper ions and copper chlorophyll sodium as a composite copper source (electrolyte) in the embodiments of the present application.

[0034] As a specific embodiment of the present application, the micro-arc oxidation process can be accompanied by ultrasonic assistance, the frequency of the ultrasonic assistance can be 45-55 kHz, and can be specifically 50 kHz; the power of the ultrasonic assistance can be 150-250 W, and can be specifically 200 W. The present application can promote the convection of the solution during the micro-arc oxidation process, ensure the enrichment of Cu in the electrolyte near the anode surface, that is, after the SCC is consumed, the replenishment is carried out in time (mechanical effect), and at the same time, defects are introduced into the surface passivation film to promote the arcing effect (cavitation effect); thereby the thickness and compactness of the film layer can be improved. The present application selects the electro-attractive effect of the negatively charged copper chlorophyll complex ion on the positively charged copper ion to form a composite copper source, the alloy substrate is micro-arc oxidized as the anode, the inert electrode is micro-arc oxidized as the cathode, and the external ultrasonic assistance is added during the micro-arc oxidation process. Through the electromigration of the external electric field and the convection effect of the ultrasonic field, the directional migration of the copper ion to the surface of the alloy substrate is promoted, the content of copper on the surface of the alloy substrate is greatly improved, the mass percentage of copper in the film layer is improved, and the corrosion resistance and antifouling performance of the film layer are improved.

[0035] The present application also provides a copper-doped micro-arc oxidation film prepared by the preparation method described above, and the mass percentage of copper doping in the copper-doped micro-arc oxidation film is 0.8-5.5%, can be 1.4-5.1%, and can be specifically 2%, 3%, 4% or 5%. The present application improves the Cu doping amount while ensuring the growth and corrosion resistance of the micro-arc oxidation film layer, and finally realizes the improvement of the antifouling performance of the micro-arc oxidation film layer.

[0036] The present application can be used to prepare a workpiece of a through-hull pipeline system after forming a copper-doped micro-arc oxidation film on the surface of the titanium alloy, and has high corrosion resistance and antifouling performance, thereby prolonging the service life.

[0037] In order to further illustrate the present application, the technical solutions provided by the present application are described in detail below in conjunction with the embodiments, but they should not be understood as limiting the scope of protection of the present application.

[0038] Example 1 (1) TC4 titanium alloy as the substrate, the TC4 titanium alloy for cleaning oil dirt, then with 600#, 1000#, 1500#, 2000# sandpaper step by step polishing, washing with acetone and drying; TC4 titanium alloy with insulating tape, to ensure that the reaction surface size is 20mm x 20mm; (2) using a magnetic stirrer on copper sulfate, sodium copper chlorophyll, sodium silicate, sodium dodecyl sulfate, mass concentration of 5g / L potassium hydroxide solution and deionized water magnetic stirring, get electrolyte; the molar concentration of the components in the electrolyte: 0.12mol / L sodium silicate, 0.04mol / L of chlorophyll copper sodium (SCC), 0.08mol / L copper sulfate, 0.015mol / L dodecyl sulfate sodium; the pH value of the electrolyte is in the range of 9.5~10.5 (the pH value of the electrolyte is controlled by potassium hydroxide solution); (3) with pretreated TC4 alloy as anode, stainless steel as cathode, anode, cathode connected pulse power (micro-arc oxidation power supply); the distance between the cathode and the anode plate is 6cm, and they are placed in the electrolyte; set the parameters of micro-arc oxidation: the current density of constant current (the highest working voltage is 600V) is 0.08A / cm 2 , the frequency is 600Hz, the total duty cycle is 20%, the temperature is 30℃, and the time is 600s; at the same time, the ultrasonic field is started, and the ultrasonic assistance (UA) is carried out, and the parameters are: the frequency is 50kHz; the power is 200W; (4) after micro-arc oxidation, the TC4 titanium alloy with micro-arc oxidation film layer (ceramic film layer) is taken out and washed with deionized water, and naturally dried to obtain a TC4 titanium alloy with copper doped micro-arc oxidation film.

[0039] Example 2 (1) TA1 titanium alloy as the substrate, the TA1 titanium alloy for cleaning oil dirt, then with 600#, 1000#, 1500#, 2000# sandpaper step by step polishing, washing with acetone and drying; TA1 titanium alloy with insulating tape, to ensure that the reaction surface size is 10mm x 10mm; (2) using a magnetic stirrer on copper sulfate, sodium copper chlorophyll, sodium silicate, sodium dodecyl sulfate, mass concentration of 5g / L potassium hydroxide solution and deionized water magnetic stirring, get electrolyte; the molar concentration of the components in the electrolyte: 0.08mol / L sodium silicate, 0.01mol / L of chlorophyll copper sodium (SCC), 0.01mol / L copper sulfate, 0.005mol / L dodecyl sulfate sodium; the pH value of the electrolyte is in the range of 9.5~10.5 (the pH value of the electrolyte is controlled by potassium hydroxide solution); (3) The pretreated TA1 alloy is used as an anode, and stainless steel is used as a cathode. The anode and the cathode are connected to a pulse power source (a micro-arc oxidation power source). The distance between the cathode and the anode plate is 12 cm, and they are placed in an electrolyte. The parameters of micro-arc oxidation are set as follows: the current density of constant current (the highest working voltage is 600 V) is 0.12 A / cm 2 , the frequency is 100 Hz, the total duty cycle is 20%, the temperature is 30°C, and the time is 300 s. At the same time, an ultrasonic field is started to perform ultrasonic assistance (UA), and the parameters are as follows: the frequency is 50 kHz, and the power is 200 W. (4) After micro-arc oxidation, the TA1 titanium alloy with a micro-arc oxidation film layer (ceramic film layer) is taken out, washed with deionized water, and naturally dried to obtain a TA1 titanium alloy with a copper-doped micro-arc oxidation film.

[0040] Example 3 (1) The TA3 titanium alloy is used as a substrate. The TA3 titanium alloy is cleaned to remove oil stains, and then polished with 600#, 1000#, 1500#, and 2000# sandpaper. After being washed with acetone and dried, the TA3 titanium alloy is wrapped with insulating tape to ensure that the reaction surface has a size of 15 mm x 15 mm. (2) The copper sulfate, sodium copper chlorophyllin, sodium silicate, sodium dodecyl sulfate, potassium hydroxide solution with a mass concentration of 5 g / L, and deionized water are magnetically stirred by using a magnetic stirrer to obtain an electrolyte. The molar concentrations of the components in the obtained electrolyte are as follows: 0.10 mol / L of sodium silicate, 0.02 mol / L of sodium copper chlorophyllin (SCC), 0.08 mol / L of copper sulfate, and 0.01 mol / L of sodium dodecyl sulfate. The pH value of the electrolyte is in the range of 9.5-10.5. (3) The pretreated TA3 alloy is used as an anode, and stainless steel is used as a cathode. The anode and the cathode are connected to a pulse power source (a micro-arc oxidation power source). The distance between the cathode and the anode plate is 12 cm, and they are placed in an electrolyte. The parameters of micro-arc oxidation are set as follows: the current density of constant current (the highest working voltage is 600 V) is 0.10 A / cm 2 , the frequency is 1000 Hz, the total duty cycle is 10%, the temperature is 30°C, and the time is 1000 s. At the same time, an ultrasonic field is started to perform ultrasonic assistance (UA), and the parameters are as follows: the frequency is 50 kHz, and the power is 200 W. (4) After micro-arc oxidation, the TA3 titanium alloy with a micro-arc oxidation film layer (ceramic film layer) is taken out, washed with deionized water, and naturally dried to obtain a TA3 titanium alloy with a copper-doped micro-arc oxidation film.

[0041] Comparative Example 1 A micro-arc oxidation film is prepared on the surface of a TC4 titanium alloy according to the method of Example 1, except that the copper source in the electrolyte is 0.08 mol / L of copper sulfate (without adding SCC).

[0042] Comparative Example 2 A micro-arc oxidation film was prepared on the surface of TC4 titanium alloy according to the method of Example 1, except that the copper source in the electrolyte was 0.04 mol / L SCC (no copper sulfate was added).

[0043] Comparative Example 3 A micro-arc oxidation film was prepared on the surface of TC4 titanium alloy according to the method of Example 1, except that no ultrasonic assistance was performed during the micro-arc oxidation process.

[0044] Comparative Example 4 A micro-arc oxidation film was prepared on the surface of TC4 titanium alloy according to the method of Example 1, except that the copper source in the electrolyte was 0.002 mol / L SCC (no copper sulfate was added). Comparative Example 5 A micro-arc oxidation film was prepared on the surface of TC4 titanium alloy according to the method of Example 1, except that the copper source in the electrolyte was 0.05 mol / L SCC (no copper sulfate was added). Comparative Example 6 A micro-arc oxidation film was prepared on the surface of TA1 titanium alloy according to the method of Example 2, except that the copper source in the electrolyte was 0.01 mol / L copper sulfate (no SCC was added).

[0045] Comparative Example 7 A micro-arc oxidation film was prepared on the surface of TA1 titanium alloy according to the method of Example 2, except that the copper source in the electrolyte was 0.01 mol / L SCC (no copper sulfate was added).

[0046] Comparative Example 8 A micro-arc oxidation film was prepared on the surface of TA1 titanium alloy according to the method of Example 2, except that no ultrasonic assistance was performed during the micro-arc oxidation process.

[0047] Comparative Example 9 A micro-arc oxidation film was prepared on the surface of TA1 titanium alloy according to the method of Example 2, except that the SCC in the electrolyte was replaced by the same concentration of Cu-EDTA (0.01 mol / L copper sodium ethylenediaminetetraacetate), and no copper sulfate was added.

[0048] Comparative Example 10 A micro-arc oxidation film was prepared on the surface of TA1 titanium alloy according to the method of Example 2, except that the SCC in the electrolyte was replaced by the same concentration of Cu-EDTA (0.01 mol / L copper sodium ethylenediaminetetraacetate), and the same amount of copper sulfate was added.

[0049] Comparative Example 11 The micro-arc oxidation film was prepared on the surface of TA3 titanium alloy according to the method of Example 3, except that the copper source in the electrolyte was 0.08 mol / L copper sulfate (without adding SCC).

[0050] Comparative Example 12 The micro-arc oxidation film was prepared on the surface of TA3 titanium alloy according to the method of Example 3, except that the copper source in the electrolyte was 0.02 mol / L SCC (without adding copper sulfate).

[0051] Comparative Example 13 The micro-arc oxidation film was prepared on the surface of TA3 titanium alloy according to the method of Example 3, except that the ultrasonic assistance was not performed during the micro-arc oxidation process.

[0052] Comparative Example 14 The micro-arc oxidation film was prepared on the surface of TA3 titanium alloy according to the method of Example 3, except that the SCC in the electrolyte was replaced by the same concentration of Cu-EDTA (0.02 mol / L copper sodium ethylenediamine tetraacetate), and the unchanged content of copper sulfate was not added.

[0053] Comparative Example 15 The micro-arc oxidation film was prepared on the surface of TA3 titanium alloy according to the method of Example 3, except that the SCC in the electrolyte was replaced by the same concentration of Cu-EDTA (0.02 mol / L copper sodium ethylenediamine tetraacetate), and the unchanged content of copper sulfate was not added.

[0054] The copper-doped micro-arc oxidation films formed in Examples 1-3 were subjected to scanning electron microscope detection, and the SEM images are shown in FIG. 1, wherein FIG. 1a is the SEM image of Example 1, FIG. 1b is the SEM image of Example 2, and FIG. 1c is the SEM image of Example 3. Figures 2-4 Figure 2 Figure 3 Figure 4 Figures 2-4 It can be seen from FIG. 1 that the copper-doped micro-arc oxidation films are formed in Examples 1-3, and the film layers are porous film layers.

[0055] The copper contents in the micro-arc oxidation films in Examples 1-3 and Comparative Examples 1-15 were detected by a fluorescence spectrometer (XRF), and the results are listed in Table 1; the columnar comparison chart of the copper contents in the micro-arc oxidation films of different examples is shown in FIG. 2, wherein FIG. 2a is the columnar comparison chart of the copper contents in the micro-arc oxidation films of Example 1 and Comparative Examples 1-5, FIG. 2b is the columnar comparison chart of the copper contents in the micro-arc oxidation films of Example 2 and Comparative Examples 6-10, and FIG. 2c is the columnar comparison chart of the copper contents in the micro-arc oxidation films of Example 3 and Comparative Examples 11-15. Figures 5-7 Figure 5 Figure 6 Figure 7 Figures 5-7 ​​​​​​​​It can be seen that the copper-doped micro-arc oxidation film provided by the application contains a higher content of copper.

[0056] The low-frequency (0.01 Hz) impedance modulus of the micro-arc oxidation films of Examples 1-3 and Comparative Examples 1-15 was detected with the sample to be tested as the working electrode, a saturated calomel electrode as the reference electrode, and a Pt electrode as the counter electrode, and the results are shown in Table 1. The detection conditions include: the input signal is a sine wave with an amplitude of 5 mV, scanning is performed in a frequency range of 100 kHz-0.01 Hz, the temperature is room temperature, and the solution is a 3.5 wt% NaCl solution. The columnar comparison chart of the low-frequency impedance modulus of the micro-arc oxidation films of different examples is shown in Figures 8-10 , wherein Figure 8 is the columnar comparison chart of the low-frequency impedance modulus of the micro-arc oxidation films of Examples 1 and Comparative Examples 1-5, Figure 9 is the columnar comparison chart of the low-frequency impedance modulus of the micro-arc oxidation films of Examples 2 and Comparative Examples 6-10, Figure 10 is the columnar comparison chart of the low-frequency impedance modulus of the micro-arc oxidation films of Examples 3 and Comparative Examples 11-15.

[0057] The anti-pollution system common sulfate-reducing bacteria resistance of the micro-arc oxidation films of Examples 1-3 and Comparative Examples 1-15 was detected by using a sulfate-reducing bacteria (SRB) strain, and the obtained antibacterial rate results are shown in Table 1. The specific process includes: the sulfate-reducing bacteria were cultured in a culture medium, and after the concentration reached 10 6 cell / mL, the sample to be tested was added, and the culture was incubated at 37℃. The MPN method was used to quantitatively measure the SRB, and the antibacterial rate was calculated. The columnar comparison chart of the antibacterial rate of the micro-arc oxidation films of different examples is shown in Figures 11-13 , wherein Figure 11 is the columnar comparison chart of the antibacterial rate of the micro-arc oxidation films of Examples 1 and Comparative Examples 1-5, Figure 12 is the columnar comparison chart of the antibacterial rate of the micro-arc oxidation films of Examples 2 and Comparative Examples 6-10, Figure 13 is the columnar comparison chart of the antibacterial rate of the micro-arc oxidation films of Examples 3 and Comparative Examples 11-15.

[0058] Table 1 Performance parameters of the micro-arc oxidation films in Examples 1-3 and Comparative Examples 1-15

[0059] It can be seen from Table 1 and Figures 5-7 that the copper content in the micro-arc oxidation film layer can be increased by using copper ions and copper sodium chlorophyllin as a composite copper source in the electrolyte and accompanying sound assistance during the micro-arc oxidation process.

[0060] It can be seen from Table 1 and Figures 8-10It can be known that the micro-arc oxidation film has good corrosion resistance, thereby proving that the micro-arc oxidation film has good compactness.

[0061] In combination with Table 1 and Figures 11-13 It can be known that the micro-arc oxidation film has excellent antibacterial property.

[0062] Although the above embodiment has made a detailed description of the present application, it is only a part of the embodiments of the present application, but not all the embodiments, and people can also obtain other embodiments according to the present embodiment without creativity, and these embodiments all belong to the protection scope of the present application.

Claims

1. An electrolyte, characterized by, The electrolyte comprises a composite copper source, a film forming agent, a surfactant, a pH regulator and water. The composite copper source comprises a soluble copper salt and sodium copper chlorophyllin.

2. The electrolyte of claim 1, wherein The soluble copper salt comprises one or more of copper chloride, copper sulfate and copper nitrate. The molar ratio of the soluble copper salt and sodium copper chlorophyllin is less than or equal to 4:

1. The film forming agent comprises sodium silicate, a phosphate or a meta-aluminate.

3. The electrolyte according to claim 1 or 2, characterized in that, The molar concentration of copper ions in the electrolyte is 0.1 mol / L or less, the molar concentration of sodium copper chlorophyllin is 0.005-0.045 mol / L, the molar concentration of the film forming agent is 0.05-0.2 mol / L, and the molar concentration of the surfactant is 0.005-0.02 mol / L.

4. The electrolyte of claim 1, wherein The surfactant comprises sodium dodecyl sulfate, sodium dodecyl benzene sulfonate or sodium oleate. The pH regulator comprises a sodium hydroxide solution and / or a potassium hydroxide solution; and the pH of the electrolyte is 8-11.

5. Use of the electrolyte of any one of claims 1-4 in the preparation of a copper-doped micro-arc oxidation film.

6. A method for preparing a copper-doped micro-arc oxidation film, characterized in that, The method comprises the following steps: Micro-arc oxidation is performed using an alloy substrate as an anode and an inert electrode as a cathode to form a copper-doped micro-arc oxidation film on the surface of the alloy substrate; the electrolyte used in the micro-arc oxidation is the electrolyte of any one of claims 1-4.

7. The preparation method according to claim 6, characterized in that, The parameters of the micro-arc oxidation include: constant current mode, current density is 0.05-2.20 A / cm 2 , working frequency is 100-2000 Hz, the distance between the anode and the cathode is 3-20 cm, the duty cycle is 5-40%, the processing time is 5-40 min, and the temperature is 10-30 DEG C; The micro-arc oxidation process is assisted by ultrasound.

8. The preparation method according to claim 6, characterized in that, The alloy substrate comprises pure titanium or a titanium alloy. The titanium alloy comprises TA1 titanium alloy, TA2 titanium alloy, TA3 titanium alloy, TC4 titanium alloy, Ti-Ni alloy, Ti-2Al-2.5Zr titanium alloy, Ti-32Mo titanium alloy or Ti-Mo-Ni titanium alloy. The inert electrode comprises platinum, graphite or stainless steel.

9. The preparation method according to claim 8, characterized in that, When the alloy substrate is TC4 titanium alloy, the electrolyte used in the micro-arc oxidation comprises 0.12 mol / L sodium silicate, 0.04 mol / L sodium copper chlorophyllin, 0.08 mol / L copper sulfate and 0.015 mol / L sodium dodecyl sulfate, and the pH of the electrolyte is 9.5-10.

5. When the alloy substrate is TA1 titanium alloy, the electrolyte used in the micro-arc oxidation comprises 0.08 mol / L sodium silicate, 0.01 mol / L sodium copper chlorophyllin, 0.01 mol / L copper sulfate, 0.005 mol / L sodium dodecyl sulfate and 5 g / L potassium hydroxide, and the pH of the electrolyte is 9.5-10.

5. When the alloy substrate is TA3 titanium alloy, the electrolyte used in the micro-arc oxidation comprises 0.1 mol / L sodium silicate, 0.02 mol / L sodium copper chlorophyllin, 0.08 mol / L copper sulfate and 0.01 mol / L sodium dodecyl sulfate, and the pH of the electrolyte is 9.5-10.

5.

10. The copper-doped micro-arc oxidation film prepared by the method of any one of claims 6-9, characterized in that, The mass percentage of the copper dopant is 0.8-5.5%.

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