Preparation method of conductive oxidation film on surface of aluminum alloy

Abstract

The invention discloses an aluminum alloy surface conductive oxide film preparation method which comprises the following steps: degreasing: degreasing an aluminum alloy in a degreasing fluid, and cleaning after degreasing; deoxidizing treatment: treating the degreased and cleaned aluminum alloy in deoxidizing liquid to remove oxides on the surface of the aluminum alloy, and then cleaning; brightness treatment is conducted, specifically, the cleaned aluminum alloy subjected to deoxidation treatment is subjected to brightness treatment at the room temperature, and cleaning is conducted after brightness treatment is conducted; hard conductive anodic oxidation is conducted, specifically, hard conductive anodic oxidation treatment is conducted on the cleaned aluminum alloy subjected to brightening in oxidation liquid, an oxidation film is formed, cleaning is conducted after hard conductive anodic oxidation treatment is conducted, and drying treatment is conducted; and sealing is conducted, specifically, the dried aluminum alloy obtained after hard conductive anodic oxidation is subjected to sealing treatment in sealing liquid, drying treatment is conducted, and preparation of the hard conductive anodic oxide film is completed. The surface conductivity of the aluminum alloy is effectively improved, the strength and toughness are further improved, the preparation cost is effectively reduced, and the preparation efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of coating technology, and in particular to a method for preparing a conductive oxide film on the surface of an aluminum alloy. Background Art

[0002] Aluminum alloy is being developed and used as a light metal material. In order to improve the hardness and corrosion resistance of aluminum alloy, an oxide film is often prepared on the surface of aluminum alloy. The oxide film improves the surface hardness and corrosion resistance of aluminum alloy. However, the presence of the oxide film seriously affects the electrical conductivity of the aluminum alloy surface, thereby causing energy waste. Summary of the invention

[0003] In order to solve some or all of the technical problems existing in the above-mentioned prior art, the present invention provides a method for preparing a conductive oxide film on the surface of an aluminum alloy.

[0004] The technical solution of the present invention is as follows:

[0005] The present invention provides a method for preparing a conductive oxide film on the surface of an aluminum alloy, comprising:

[0006] Degreasing, degreasing the aluminum alloy in a degreasing liquid and washing it after degreasing;

[0007] Deoxidation treatment, treating the aluminum alloy cleaned after degreasing in a deoxidation liquid to remove oxides on the surface of the aluminum alloy, and cleaning after the deoxidation treatment;

[0008] Brightening, brightening the aluminum alloy after deoxidation treatment and cleaning at room temperature, and cleaning after brightening treatment;

[0009] Hard conductive anodizing: the aluminum alloy cleaned after brightening is subjected to hard conductive anodizing in an oxidizing solution to form an oxide film, which is then cleaned and dried.

[0010] Sealing: The aluminum alloy dried after hard conductive anodizing is placed in a sealing liquid for sealing treatment, and then dried to complete the preparation of the conductive oxide film.

[0011] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy, the degreasing liquid includes: Na2CO3: 10g / L, Na3PO4: 4g / L-6g / L, Na2B4O7: 3g / L-4g / L, and sodium gluconate 10g / L-15g / L; when the aluminum alloy is degreased with the degreasing liquid, the temperature of the degreasing liquid is: 45±5°C, and the degreasing time is: 3min-5min, and when cleaning after degreasing, warm water is first used for cleaning, the warm water temperature is 40°C-50°C, and the cleaning time is 1min-3min, and then cold water is used for cleaning, the cold water temperature is 18°C-30°C, and the cleaning time is 1min-3min.

[0012] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy, the deoxygenating liquid includes: NaOH: 5g / L-8g / L, CH3COONa: 5g / L-8g / L, sodium gluconate: 8g / L-12g / L, and triethanolamine: 6g / L-9g / L. When the deoxygenating liquid is used to deoxidize the degreased aluminum alloy, the temperature of the deoxygenating liquid is 50°C-70°C, and the deoxygenating treatment time is: 1min-3min. When cleaning after the deoxygenating treatment, cold water is used for cleaning, the cold water temperature is 18°C-30°C, and the cleaning time is 1min-3min.

[0013] Furthermore, in the above-mentioned method for preparing the conductive oxide film on the surface of aluminum alloy, the treatment time of the brightening solution is 3min-5min, and when cleaning after brightening, room temperature water is used for cleaning, the cleaning time is 3min-5min, and two ultrasonic vibrations are added during the cleaning process.

[0014] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of aluminum alloy, the oxidizing solution comprises: H2SO4: 150mL / L-170mL / L, NH4HSO4: 30g / L-50g / L, HETP: 5g / L-7g / L, additives: 100mL / L-150mL / L, AI 3 + : An appropriate amount, and when the oxidizing liquid is used to carry out hard conductive anodizing treatment on aluminum alloy, it is divided into two stages. In each stage, when the oxidizing liquid is used for hard conductive anodizing treatment, the oxidizing liquid is flowed and circulated with stirring, and ultrasonic vibration is added.

[0015] Furthermore, in the above-mentioned method for preparing the conductive oxide film on the surface of aluminum alloy, when performing hard conductive anodizing treatment, in the first stage: the temperature of the oxidizing liquid is less than 8°C, the duty cycle is 15%-20%, the frequency is 300Hz-500Hz, and the forward voltage is stepped up from 0V-5V-85V-120V within 3min-5min, and maintained for 30min-45min after reaching 120V, and the negative voltage is not turned on during this process;

[0016] The second stage: the temperature of the oxidizing liquid is less than 15℃, the duty cycle is 15%-20%, the frequency is 300Hz-500Hz, and the forward voltage adopts a segmented boost operation of 120V-160V-180V. After reaching 160V-180V, it is maintained for 30min-40min. I + :I - =10:2, in this stage the negative voltage is any fixed value between 5V-15V.

[0017] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy, the additives include: TiOSO4: 30 g / L-40 g / L, H2SO4 (98%): 10 mL / L-15 mL / L, PASP: 5 mL / L-7 mL / L, HEDP: 5 g / L-7 g / L, and JFC: 0.1 g / L-0.2 g / L.

[0018] Furthermore, in the above-mentioned method for preparing the conductive oxide film on the surface of aluminum alloy, during cleaning after the hard conductive anodizing treatment, two cold water washes are used, and during the drying treatment after cleaning, high-pressure blow drying is first used, and then drying is carried out at a temperature of 100°C-120°C, and the drying time is 15min-30min.

[0019] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy, during the sealing process, the sealing liquid includes: DJB-823: 0.5%, KT-545: 0.5mL / L-1mL / L. When the sealing liquid is used to seal the aluminum alloy after hard conductive anodizing, the sealing liquid temperature is 60°C-65°C, the sealing time is 20s-30s, ultrasonic waves are added during the immersion process, and a drying method is used during the drying process. The drying temperature is 120°C-130°C, and the drying time is 15min-20min.

[0020] Furthermore, the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy also includes a detection step, in which the electrical properties, hardness, corrosion resistance and surface properties of the conductive oxide film prepared on the surface of the aluminum alloy are detected.

[0021] The main advantages of the technical solution of the present invention are as follows:

[0022] The present invention discloses a method for preparing a conductive oxide film on the surface of an aluminum alloy. The method comprises the following steps: degreasing the aluminum alloy in a degreasing solution, performing a deoxidation treatment to remove the oxide skin on the surface of the magnesium alloy, performing a photocatalytic treatment on the deoxidized aluminum alloy in a brightening solution, performing a hard conductive anodizing treatment to improve the conductivity, strength and toughness of the aluminum alloy surface, and introducing TiN nanoparticles by means of pulse plasma discharge. The sealing process makes the coating more solid, and the prepared product has better adhesion and stress corrosion sensitivity. At the same time, the preparation cost is low and the preparation energy consumption is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the embodiments of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0024] In the figure:

[0025] Figure 1 This is a flow chart of the method for preparing a conductive oxide film on the surface of an aluminum alloy according to the present invention;

[0026] Figure 2 This is a schematic diagram of the binding force detection results in Example 1;

[0027] Figure 3 Schematic diagram of the 96h neutral salt spray test results in Example 1. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] The technical solution provided by the embodiments of the present invention is described in detail below with reference to the accompanying drawings.

[0030] Example 1

[0031] The present invention provides a method for preparing a conductive oxide film on the surface of an aluminum alloy. Figure 1 As shown, including:

[0032] Degreasing, degreasing the aluminum alloy in a degreasing liquid and washing it after degreasing;

[0033] Deoxidation treatment, deoxidation treatment of the aluminum alloy cleaned after degreasing in a deoxidation liquid to remove oxides on the surface of the aluminum alloy, and cleaning after the deoxidation treatment;

[0034] Brightening, brightening the aluminum alloy after deoxidation treatment and cleaning at room temperature, and cleaning after brightening treatment;

[0035] Hard conductive anodizing: the aluminum alloy cleaned after brightening is subjected to hard conductive anodizing in an oxidizing solution to form an oxide film, which is then cleaned and dried.

[0036] Sealing: The aluminum alloy dried after hard conductive anodizing is placed in a sealing liquid for sealing treatment, and then dried to complete the preparation of the conductive oxide film.

[0037] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy, the degreasing liquid includes: Na2CO3: 10g / L, Na3PO4: 4g / L-6g / L, Na2B4O7: 3g / L-4g / L, sodium gluconate: 10g / L-15g / L; when the aluminum alloy is degreased with the degreasing liquid, the temperature of the degreasing liquid is: 45±5°C, the degreasing time is: 3min-5min, and when cleaning after degreasing, warm water is first used for cleaning, the warm water temperature is 40°C-50°C, the cleaning time is 1min-3min, and then cold water is used for cleaning, the cold water temperature is 18°C-30°C, and the cleaning time is 1min-3min.

[0038] Preferably, Na2CO3: 10g / L, Na3PO4: 5g / L, Na2B4O7: 3g / L, sodium gluconate: 10g / L, so that the degreasing liquid has the best degreasing effect on aluminum alloy.

[0039] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy, the deoxygenating liquid includes: NaOH: 5g / L-8g / L, CH3COONa: 5g / L-8g / L, sodium gluconate: 8g / L-12g / L, and triethanolamine: 6g / L-9g / L. When the deoxygenating liquid is used to deoxidize the degreased aluminum alloy, the temperature of the deoxygenating liquid is 50°C-70°C, and the deoxygenating treatment time is: 1min-3min. When cleaning after the deoxygenating treatment, cold water is used for cleaning, the cold water temperature is 18°C-30°C, and the cleaning time is 1min-3min.

[0040] Preferably, NaOH: 8 g / L, CH3COONa: 8 g / L, sodium gluconate: 10 g / L, triethanolamine: 7 g / L, so that the deoxidizing liquid has the best effect on removing oxide scale from aluminum alloy.

[0041] Furthermore, in the above-mentioned method for preparing the conductive oxide film on the surface of aluminum alloy, the treatment time of the brightening solution is 3min-5min, and when cleaning after brightening, room temperature water is used for cleaning, the cleaning time is 3min-5min, and two ultrasonic vibrations are added during the cleaning process.

[0042] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of aluminum alloy, the oxidizing solution includes: H2SO4: 150mL / L-170mL / L, NH4HSO4: 30g / L-50g / L, HETP: 5g / L-7g / L, additives: 100mL / L-150mL / L, AI 3+ : An appropriate amount, and when the oxidizing liquid is used to carry out hard conductive anodizing treatment on aluminum alloy, it is divided into two stages. In each stage, when the oxidizing liquid is used for hard conductive anodizing treatment, the oxidizing liquid is flowed and circulated with stirring, and ultrasonic vibration is added.

[0043] Preferably, H2SO4: 160 mL / L, NH4HSO4: 40 g / L, HETP: 6 g / L, additive: 120 mL / L, so that the oxidizing solution has the best hard conductive anodizing effect on aluminum alloy.

[0044] Furthermore, in the above-mentioned method for preparing the conductive oxide film on the surface of aluminum alloy, when performing hard conductive anodizing treatment, in the first stage: the temperature of the oxidizing liquid is less than 8°C, the duty cycle is 15%-20%, the frequency is 300Hz-500Hz, and the forward voltage is stepped up from 0V-5V-85V-120V within 3min-5min, and maintained for 30min-45min after reaching 120V, and the negative voltage is not turned on during this process;

[0045] The second stage: the temperature of the oxidizing liquid is less than 15℃, the duty cycle is 15%-20%, the frequency is 300Hz-500Hz, and the forward voltage adopts a segmented boost operation of 120V-160V-180V. After reaching 160V-180V, it is maintained for 30min-40min. I + :I - =10:2, in this stage the negative voltage is any fixed value between 5V-15V.

[0046] Hard anodizing process: (i.e. the formation process of nano-Al2O3 film)

[0047] After aluminum alloy comes into contact with oxidizing liquid, ①H2O=H + +OH - ;②4OH - =2H2O+O2; ③4Al+3O2=2Al2O3 (Due to the use of pulse current, the amount of reaction ②+③ is limited, so that Al2O3 crystals cannot be continuously generated and nano-crystals are formed)

[0048] Hard anodizing has a faster heat dissipation and a small amount of SO4 2-Ions are deposited in the film layer, making it black and increasing its hardness. Therefore, for hard anodizing, temperature and SO4 2- The concentration is the key, and in terms of influencing factors, temperature>SO4 2- >Al 3+ , Al 3+ If the concentration is too high, diffusion will not occur in time and discontinuous Al2O3 blocks will be formed.

[0049] Conductive formation of hard oxide layer (formation of TiN doping)

[0050] After the hard nano-oxide layer is formed, due to the discontinuity of α-Al2O3, although the volume expansion will occur in the process of Al+O2→Al2O3 in the surface layer, and then the surface bending will be formed due to the surface layer compressive stress, but under the surface effect and size effect of nanoparticles, this bending is not very strong in degree, so its surface dissolution is not good, and the electroosmosis effect is slow. After the addition of HEDP, on the one hand, the Al 3+ The disturbance of concentration near the anode, on the other hand, accelerates the dissolution of the curved bottom and promotes the occurrence of electroosmosis.

[0051] The presence of HEDP destroys the barrier layer, resulting in the infiltration of cations.

[0052] TiN particle generation and doping formation: ④NH 4+ +H2S2O7+H2S2O8→N+H2SO4; ⑤Ti 4+ +N→Ti3N4;

[0053] ④ In the reaction equation, H2S2O7 and H2S2O8 are SO4 2- Intermediates formed by the concentration of ions;

[0054] In addition, due to the high voltage (average voltage and instantaneous voltage) at this time, plasma discharge is generated, so

[0055] ⑥Al2O3+TiN→xAl2O3·yTiN·nH2O, thus forming a conductive layer.

[0056] At this time, the oxidation current gradually increases, and then stabilizes after reaching a certain value.

[0057] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy, the additives include: TiOSO4: 30 g / L-40 g / L, H2SO4 (98%): 10 mL / L-15 mL / L, PASP: 5 mL / L-7 mL / L, HEDP: 5 g / L-7 g / L, and JFC: 0.1 g / L-0.2 g / L.

[0058] Preferably, TiOSO4: 35 g / L, H2SO4 (98%): 12 mL / L, PASP: 6 mL / L, HEDP: 6 g / L, JFC: 0.1 g / L.

[0059] Furthermore, in the above-mentioned method for preparing the conductive oxide film on the surface of aluminum alloy, during cleaning after the hard conductive anodizing treatment, two cold water washes are used, and during the drying treatment after cleaning, high-pressure blow drying is first used, and then drying is carried out at a temperature of 100°C-120°C, and the drying time is 15min-30min.

[0060] Furthermore, in the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy, during the sealing process, the sealing liquid includes: DJB-823: 0.5%, KT-545: 0.5mL / L-1mL / L. When the sealing liquid is used to seal the aluminum alloy after hard conductive anodizing, the sealing liquid temperature is 60°C-65°C, the sealing time is 20s-30s, ultrasonic waves are added during the immersion process, and a drying method is used during the drying process. The drying temperature is 120°C-130°C, and the drying time is 15min-20min.

[0061] The medicinal principle is:

[0062] α-Al2O3 has the characteristics of high melting point, high hardness, corrosion resistance, oxidation resistance, and non-toxicity. In particular, Al2O3-based nanocomposites have very high mechanical properties, and this single-phase Al2O3 has higher strength and toughness.

[0063] TiN (titanium nitride) has the characteristics of high hardness, high melting point, good chemical stability, and electrical conductivity. Al2O3 ceramics with TiN as the reinforcement phase can not only improve the conductivity of the ceramics, but also further increase the strength and toughness.

[0064] On the basis of aluminum alloy hard anodized film, TiN nanoparticles are introduced by means of pulse plasma discharge and directly sintered into Al2O3·TiN composite ceramics.

[0065] Furthermore, the above-mentioned method for preparing a conductive oxide film on the surface of an aluminum alloy also includes a detection step, in which the electrical properties, hardness, corrosion resistance and surface properties of the conductive oxide film prepared on the surface of the aluminum alloy are detected.

[0066] like Figure 2 As shown, the bonding strength of the conductive oxide film is tested using the Hundred Grid method;

[0067] As shown in Table 1, the thickness of the conductive oxide film is tested:

[0068] Table 1 Conductive oxide film thickness

[0069]

[0070] As shown in Table 2, the absorbance of the conductive oxide film was detected using a L(a+b) colorimeter:

[0071] Table 2 Absorbance of conductive oxide film

[0072]

[0073]

[0074] The conductive oxide film resistance is tested as shown in Table 3:

[0075] Conductive Oxide Film Resistors

[0076]

[0077] like Figure 3 As shown, the corrosion resistance is tested by a neutral salt spray test for 96 hours.

[0078] In summary, compared with the prior art, the method for preparing a conductive oxide film on the surface of an aluminum alloy according to the embodiment of the present invention has the following advantages and beneficial effects:

[0079] The present invention discloses a method for preparing a conductive oxide film on the surface of an aluminum alloy. The method comprises the following steps: degreasing the aluminum alloy in a degreasing solution, performing a deoxidation treatment to remove the oxide skin on the surface of the magnesium alloy, performing a photocatalytic treatment on the deoxidized aluminum alloy in a brightening solution, performing a hard conductive anodizing treatment to improve the conductivity, strength and toughness of the aluminum alloy surface, and introducing TiN nanoparticles by means of pulse plasma discharge. The sealing process makes the coating more solid, and the prepared product has better adhesion and stress corrosion sensitivity. At the same time, the preparation cost is low and the preparation energy consumption is low.

[0080] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In addition, "front", "back", "left", "right", "upper" and "lower" in this article are all referenced to the placement state shown in the accompanying drawings.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a conductive oxide film on the surface of an aluminum alloy, characterized in that: include: Degreasing, degreasing the aluminum alloy in a degreasing liquid and washing it after degreasing; Deoxidation treatment, treating the aluminum alloy cleaned after degreasing in a deoxidation liquid to remove oxides on the surface of the aluminum alloy, and cleaning after the deoxidation treatment; Brightening, brightening the aluminum alloy after deoxidation treatment and cleaning at room temperature, and cleaning after brightening treatment; Hard conductive anodizing: the aluminum alloy cleaned after brightening is subjected to hard conductive anodizing in an oxidizing solution to form an oxide film, which is then cleaned and dried. Sealing: The aluminum alloy dried after hard conductive anodizing is placed in a sealing liquid for sealing treatment, and then dried to complete the preparation of the conductive oxide film.

2. The method for preparing a conductive oxide film on the surface of an aluminum alloy according to claim 1, characterized in that: The degreasing liquid includes: Na2CO3: 10g / L, Na3PO4: 4g / L-6g / L, Na2B4O7: 3g / L-4g / L, sodium gluconate: 10g / L-15g / L; when the degreasing liquid is used to degrease the aluminum alloy, the temperature of the degreasing liquid is: 45±5°C, the degreasing time is: 3min-5min, and when cleaning after degreasing, warm water is first used for cleaning, the warm water temperature is 40°C-50°C, the cleaning time is 1min-3min, and then cold water is used for cleaning, the cold water temperature is 18°C-30°C, and the cleaning time is 1min-3min.

3. The method for preparing a conductive oxide film on the surface of an aluminum alloy according to claim 1, characterized in that: The deoxidizing liquid comprises: NaOH: 5g / L-8g / L, CH3COONa: 5g / L-8g / L, sodium gluconate: 8g / L-12g / L, triethanolamine: 6g / L-9g / L. When the deoxidizing liquid is used to deoxidize the degreased aluminum alloy, the temperature of the deoxidizing liquid is 50°C-70°C, the deoxidizing treatment time is: 1min-3min, and when cleaning after the deoxidizing treatment, cold water is used for cleaning, the cold water temperature is 18°C-30°C, and the cleaning time is 1min-3min.

4. The method for preparing a conductive oxide film on the surface of an aluminum alloy according to claim 1, characterized in that: The treatment time of the brightening liquid is 3min-5min, and when cleaning after brightening, room temperature water is used for cleaning, the cleaning time is 3min-5min, and ultrasonic vibration is added twice during the cleaning process.

5. The method for preparing a conductive oxide film on the surface of an aluminum alloy according to claim 1, characterized in that: The oxidizing solution includes: H2SO4: 150mL / L-170mL / L, NH4HSO4: 30g / L-50g / L, HETP: 5g / L-7g / L, additives: 100mL / L-150mL / L, AI 3+ : An appropriate amount, and when the oxidizing liquid is used to carry out hard conductive anodizing treatment on aluminum alloy, it is divided into two stages. In each stage, when the oxidizing liquid is used for hard conductive anodizing treatment, the oxidizing liquid is flowed and circulated with stirring, and ultrasonic vibration is added.

6. The method for preparing a conductive oxide film on the surface of an aluminum alloy according to claim 5, characterized in that: When performing hard conductive anodizing treatment, in the first stage: the oxidation liquid temperature is less than 8°C, the duty cycle is 15%-20%, the frequency is 300Hz-500Hz, and the forward voltage is stepped up from 0V-5V-85V-120V within 3min-5min, and maintained for 30min-45min after reaching 120V. During this process, no negative voltage is turned on; The second stage: the temperature of the oxidizing liquid is less than 15℃, the duty cycle is 15%-20%, the frequency is 300Hz-500Hz, and the forward voltage adopts a segmented boost operation of 120V-160V-180V. After reaching 160V-180V, it is maintained for 30min-40min. I + :I - =10:2, in this stage the negative voltage is any fixed value between 5V-15V.

7. The method for preparing a conductive oxide film on the surface of an aluminum alloy according to claim 5, characterized in that: The additives include: TiOSO4: 30g / L-40g / L, H2SO4 (98%): 10mL / L-15mL / L, PASP: 5mL / L-7mL / L, HEDP: 5g / L-7g / L, and JFC: 0.1g / L-0.2g / L.

8. The method for preparing a conductive oxide film on the surface of an aluminum alloy according to claim 1, characterized in that: When cleaning after hard conductive anodizing treatment, use two cold water washes. When drying after cleaning, first use high-pressure blow drying, then dry at a temperature of 100℃-120℃, and the drying time is 15min-30min.

9. The method for preparing a conductive oxide film on the surface of an aluminum alloy according to claim 1, characterized in that: During the sealing process, the sealing liquid includes: DJB-823: 0.5%, KT-545: 0.5mL / L-1mL / L. When the sealing liquid is used to seal the aluminum alloy after hard conductive anodizing, the sealing liquid temperature is 60℃-65℃, the sealing time is 20s-30s, ultrasonic waves are added during the immersion process, and a drying method is used during the drying process. The drying temperature is 120℃-130℃ and the drying time is 15min-20min.

10. The method for preparing a conductive oxide film on the surface of an aluminum alloy according to claim 1, characterized in that: The method also includes a testing step for testing the electrical properties, hardness, corrosion resistance and surface properties of the conductive oxide film prepared on the surface of the aluminum alloy.

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