High-binding strength, salt-spray-resistant, low-resistance oxide film sealing liquid, preparation method, and use method thereof

Abstract

The present invention discloses a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid, and its preparation and use methods. The preparation method comprises: taking KH-550 silane coupling agent, anhydrous ethanol, and pure water, stirring and mixing them thoroughly, heating in a water bath, and then cooling to room temperature to prepare liquid A; taking pyrophosphoric acid and phosphoric acid and dissolving them in pure water to prepare liquid B; taking ethylenediamine and diethylenetriamine and dissolving them in pure water to prepare liquid C; adding KOH to a C2H5OH solution, freezing it to 45°C, then dropwise adding an AgNO3 solution to an alkaline alcohol solution, standing it at low temperature, filtering it, washing the precipitate with a C2H5OH solution, and retaining the precipitate for later use; mixing liquids A and C and stirring them evenly, adjusting the pH of the mixed liquid to 6.5-7.5 with liquid B to prepare liquid D; adding the precipitate to liquid D, stirring it rapidly, cooling it, and standing it, taking the clarified liquid to prepare a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid. The oxide film sealed by the sealing liquid of the present invention has high conductivity, salt spray resistance and excellent surface organic coating bonding strength.

Description

Technical Field

[0001] The invention belongs to the technical field of surface treatment of magnesium alloy products, and particularly relates to a high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid, and a preparation method and a use method thereof. Background Art

[0002] As a green and lightweight structural material, magnesium alloy is widely used in rail transportation, automotive parts, aerospace and other fields. In actual application, it is usually necessary to treat the surface of magnesium alloy to improve its corrosion resistance.

[0003] Chemical oxidation is one of the main methods for magnesium alloy surface treatment, including anodic oxidation and micro-arc oxidation. Due to the microporous structure on the surface of these films, the existing technology often uses inorganic salt hydrolysis sealing, water boiling sealing, organic filling sealing (such as using alcohol solutions of silane coupling agents or alcohol-water solutions of ethyl silicate), paint coating sealing, etc. These methods, while improving corrosion resistance, often increase the film resistance sharply and sharply reduce the adhesion between the metal substrate and the surface organic coating. As a result, in some applications requiring local coating with high surface conductivity, it is often contradictory and cannot meet the requirements of perfection.

[0004] Therefore, developing an environmentally friendly aqueous sealing liquid that can make the oxide film resistant to salt spray while having low resistance and excellent surface organic coating adhesion is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid and a preparation method and a use method thereof.

[0006] In one aspect of the present invention, a method for preparing a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid is provided, comprising the following steps:

[0007] Step 1: Take 20g of KH-550 silane coupling agent, 75g of anhydrous ethanol, and 8g of purified water, stir and mix thoroughly, heat in a water bath at 60-80°C for 3-4h, and then cool to room temperature to prepare solution A;

[0008] Step 2: Dissolve 10 g of pyrophosphoric acid and 5 g of phosphoric acid in 85 g of pure water to prepare Solution B.

[0009] Step 3: Dissolve 10 mL of ethylenediamine and 30 mL of diethylenetriamine in 60 mL of pure water and cool to room temperature to obtain Solution C.

[0010] Step 4: Add 5 g of KOH to 100 mL of a 90% C2H5OH solution to form an alkaline alcohol solution, freeze the solution to -45°C, and then slowly dropwise add 100 mL of a 5% AgNO3 solution to the alkaline alcohol solution while stirring. After the addition is complete, allow to stand at low temperature for 30 to 40 minutes, filter, and wash the precipitate with a 90% C2H5OH solution. Keep the precipitate for later use.

[0011] Step 5: Mix solution A and solution C and stir evenly, and adjust the pH of the mixed solution to 6.5-7.5 with solution B to obtain solution D.

[0012] Step 6: Add the precipitate obtained in step 4 to liquid D, stir rapidly at a stirring speed of 200-300 r / min for 30-40 minutes, then cool and stand for 1-2 hours, take the clarified liquid for use, and prepare a high-binding strength, salt spray-resistant, low-resistance oxide film sealing liquid.

[0013] In another aspect of the present invention, a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid is provided. The high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid is prepared by the above-mentioned preparation method.

[0014] In another aspect of the present invention, a method for using a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid is provided, wherein the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid is prepared by the above-mentioned method for preparing a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid, and the method for using the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid comprises:

[0015] Spraying a high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid directly onto the surface of the golden conductive oxide film of the magnesium alloy plate, leveling it at room temperature for 10 to 20 minutes, placing it in an oven and baking it in multiple steps, and then cooling it to room temperature with the oven, wherein the multiple step baking sequence includes: baking at 50°C for 15 minutes, baking at 70°C for 10 minutes, baking at 120°C for 10 minutes, and baking at 200°C for 15 minutes; or

[0016] The high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid is diluted 5 to 8 times by volume with pure water, and a magnesium alloy plate prepared with a golden conductive chemical oxide film is immersed in the diluted sealing liquid and vibrated with 50W ultrasonic waves for 1 to 3 minutes. After being taken out of the bath, it is leveled at room temperature for 5 to 10 minutes, and then rinsed with pure water for 1 to 5 minutes. The water droplets hanging on the surface of the magnesium alloy plate are blown dry with dry high-pressure air. After evaporation at room temperature for 10 to 15 minutes, it is baked in an oven in multiple steps and then cooled to room temperature with the furnace. The multiple step-by-step baking sequence includes: baking at 90°C for 10 minutes, baking at 150°C for 10 minutes, and baking at 250°C for 10 minutes.

[0017] The high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid provided by the present invention utilizes KH-550 silane coupling agent and polyvalent organic amines for complexation to form an AgOH monolayer, and then controls the baking temperature and time to ultimately form an Ag2O monolayer. Furthermore, the interaction of ethylenediamine, diethylenetriamine, phosphoric acid, pyrophosphoric acid, etc. is utilized to form a three-dimensional structural network with fewer defects. The oxide film sealed with the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid of the present invention simultaneously has the characteristics of high conductivity, salt-fog resistance, and excellent surface organic coating bonding strength. Moreover, the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid of the present invention is an aqueous sealing liquid, and has the advantages of being safe, environmentally friendly, and easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 The figure is a comparison chart of the salt spray corrosion resistance test results of the embodiment of the present invention and the comparative example. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] The method for preparing a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid of the present invention comprises the following steps:

[0022] Step 1: Take 20g of KH-550 silane coupling agent, 75g of anhydrous ethanol, and 8g of purified water, stir and mix thoroughly, heat in a water bath at 60-80°C for 3-4h, and then cool to room temperature to prepare solution A;

[0023] Step 2: Dissolve 10 g of pyrophosphoric acid and 5 g of phosphoric acid in 85 g of pure water to prepare Solution B.

[0024] Step 3: Dissolve 10 mL of ethylenediamine and 30 mL of diethylenetriamine in 60 mL of pure water and cool to room temperature to obtain Solution C.

[0025] Step 4: Add 5 g of KOH to 100 mL of a 90% C2H5OH solution to form an alkaline alcohol solution, freeze the solution to -45°C, and then slowly add 100 mL of a 5% AgNO3 solution dropwise to the alkaline alcohol solution while stirring. After the addition is complete, allow to stand at low temperature for 30 to 40 minutes, filter, and wash the precipitate with a 90% C2H5OH solution. Keep the precipitate for later use.

[0026] Step 5: Mix solution A and solution C and stir evenly, and adjust the pH of the mixed solution to 6.5-7.5 with solution B to obtain solution D.

[0027] Step 6: Add the precipitate obtained in step 4 to liquid D, stir rapidly at a stirring speed of 200-300 r / min for 30-40 minutes, then cool and stand for 1-2 hours, take the clarified liquid for use, and prepare a high-binding strength, salt spray-resistant, low-resistance oxide film sealing liquid.

[0028] The principle of the sealing, conductivity and bonding strength enhancement of the high-bonding strength, salt-fog-resistant, low-resistance oxide film sealing liquid prepared by the above-mentioned preparation method of the high-bonding strength, salt-fog-resistant, low-resistance oxide film sealing liquid is as follows:

[0029] 1.

[0030] 2. AgNO3+NaOH→AgOH↓+NaNO3

[0031] 3.(1)Silanol

[0032]

[0033] 3.(2) Ethylenediamine

[0034]

[0035] 3.(3)Diethylenetriamine

[0036]

[0037] 3.(4) Ethylenediamine and pyrophosphate

[0038]

[0039] 3.(5) Ethylenediamine and phosphoric acid

[0040]

[0041] 3.(6) Silanol and pyrophosphate

[0042]

[0043] 4. (1) Condensation between silanols

[0044]

[0045] 4.(2) Reaction of silanol condensation products with AgOH, diethylenetriamine, and ethylenediamine

[0046]

[0047] 4.(3) Further condensation with pyrophosphate

[0048]

[0049] Bottom-up monolayer

[0050] 4. (4) Heating shrinkage and film drying and the formation process of AgO monolayer

[0051] ①At 200-300℃, H3PO4 will further cross-link with pyrophosphoric acid and itself;

[0052] ② Ethylenediamine reaches its boiling point at around 120°C and completely evaporates;

[0053] ③Diethylenetriamine reaches its boiling point at around 210℃ and completely evaporates;

[0054] ④AgOH begins to decompose into AgO at around 100℃, while AgO rapidly decomposes and releases O2 at 250℃ and completely decomposes at 300℃ (AgO decomposes into Ag2O at 100-200℃, and the product Ag2O is stable up to 350℃. At 400℃, Ag2O decomposes into Ag and O2);

[0055] ⑤The final product after baking at 150℃ for 30-60min:

[0056]

[0057] In the above three-dimensional structure network, the c layer forms a seal to fill the gaps in the oxide film, especially The unit effectively blocks O₂ intrusion, enhancing the corrosion resistance of the oxide film. Furthermore, the -OH groups in the unit directly combine with metal oxides, strengthening the adhesion of the entire network structure to the underlying oxide film. Layers b and d are compatible with resins such as epoxy, amino, and polyurethane, enhancing the bond between the organic coating and the substrate. Layer a is a monolayer of Ag₂O, present as linear overlapping layers within the three-dimensional network structure. It exists in conjunction with the nitrogen atoms in layer e, while retaining the independent physical properties of Ag₂O and possessing excellent electrical conductivity.

[0058] The method for using the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid of the present invention comprises:

[0059] Spraying a high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid directly onto the surface of the golden conductive oxide film of the magnesium alloy plate, leveling it at room temperature for 10 to 20 minutes, placing it in an oven and baking it in multiple steps, and then cooling it to room temperature with the oven, wherein the multiple step baking sequence includes: baking at 50°C for 15 minutes, baking at 70°C for 10 minutes, baking at 120°C for 10 minutes, and baking at 200°C for 15 minutes; or

[0060] The high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid is diluted 5 to 8 times by volume with pure water, and a magnesium alloy plate prepared with a golden conductive chemical oxide film is immersed in the diluted sealing liquid and vibrated with 50W ultrasonic waves for 1 to 3 minutes. After being taken out of the bath, it is leveled at room temperature for 5 to 10 minutes, and then rinsed with pure water for 1 to 5 minutes. The water droplets hanging on the surface of the magnesium alloy plate are blown dry with dry high-pressure air. After evaporation at room temperature for 10 to 15 minutes, it is baked in an oven in multiple steps and then cooled to room temperature with the furnace. The multiple step-by-step baking sequence includes: baking at 90°C for 10 minutes, baking at 150°C for 10 minutes, and baking at 250°C for 10 minutes.

[0061] The performance of the high-binding strength, salt-spray-resistant, low-resistance oxide film sealing liquid of the present invention is described in detail below in conjunction with specific comparative examples and embodiments of the present invention.

[0062] Example 1

[0063] 1. Take an AZ31B magnesium alloy plate with a size of 80×120×2mm;

[0064] 2. Degreasing: The degreasing solution used includes 5g / L NaOH, 3g / L Na2CO3, 3g / L Na3PO4, 1g / L Na2SiO3, and 0.01g / L OP-10. Degreasing treatment is carried out at 50-60℃ for 1-3min.

[0065] 3. Washing: First wash with 50-60℃ hot water, then rinse with tap water;

[0066] 4. Acid etching: The acid etching solution used includes 10mL / L HNO3 (1.41), 1-2g / L NH4HF2 (1.84), 1mL / L H2SO4, and 2mL / L triethylenetetramine. Acid etching is carried out at room temperature for 1-5 minutes and then cleaned until the surface is bright white.

[0067] 5. Preparation of golden conductive chemical oxidation film: use 4g / L CrO3, 3g / L K2Cr2O7·2H2O, 0.5-0.8g / L KF, and treat at room temperature for 1-3min;

[0068] 6. Rinse with tap water after bathing and dry at 100℃ for 15 minutes;

[0069] 7. Spraying high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid: Spray the high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid directly on the surface of the dried golden conductive oxide film;

[0070] 8. Drying and baking: After leveling at room temperature for 10 to 20 minutes, place in an oven and bake in multiple steps, then cool to room temperature with the oven. The multiple step baking sequence includes: baking at 50°C for 15 minutes, baking at 70°C for 10 minutes, baking at 120°C for 10 minutes, and baking at 200°C for 15 minutes.

[0071] 9. Testing: Prepare three samples according to 1-8 above. One sample is tested for conductivity, one sample is tested for salt spray, and one sample is sprayed with epoxy polyester powder and then cured for adhesion test.

[0072] Example 2

[0073] 1. Referring to 1 to 6 in Example 1, a golden conductive chemical oxidation film was prepared on a magnesium alloy plate;

[0074] 2. Dilute the high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid with pure water by 5 to 8 times by volume, immerse the magnesium alloy plate prepared with a golden conductive chemical oxide film in the dilution of the sealing liquid, and vibrate with 50W ultrasonic waves for 1 to 3 minutes.

[0075] 3. Drying and baking: After coming out of the bath, level at room temperature for 5 to 10 minutes, then rinse with pure water for 1 to 5 minutes, blow dry the water droplets on the surface of the magnesium alloy plate with dry high-pressure air, and let it volatilize at room temperature for 10 to 15 minutes. Then, bake it in an oven in multiple steps and cool it to room temperature with the oven. The multiple step-by-step baking sequence includes: baking at 90°C for 10 minutes, baking at 150°C for 10 minutes, and baking at 250°C for 10 minutes.

[0076] 4. Testing: Prepare three samples according to 1-3 above. One sample is tested for conductivity, one sample is tested for salt spray, and one sample is sprayed with epoxy polyester powder and then cured for adhesion test.

[0077] Comparative Example 1

[0078] 1. Referring to 1 to 6 in Example 1, a golden conductive chemical oxidation film was prepared on a magnesium alloy plate;

[0079] 2. According to QJ20173-2012, seal with 10g / L K2Cr2O7 and then bake dry;

[0080] 3. Testing: Prepare three samples according to 1-2 above. One sample is tested for conductivity, one sample is tested for salt spray, and one sample is sprayed with epoxy polyester powder and then cured for adhesion test.

[0081] Comparative Example 2

[0082] 1. Referring to 1 to 6 in Example 1, a golden conductive chemical oxidation film was prepared on a magnesium alloy plate;

[0083] 2. Use the solution A prepared in step 1 of the method for preparing the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid of the present invention to spray and then bake;

[0084] 3. Testing: Prepare three samples according to 1-2 above. One sample is tested for conductivity, one sample is tested for salt spray, and one sample is sprayed with epoxy polyester powder and then cured for adhesion test.

[0085] The performance evaluation of the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid of the embodiment of the present invention and the comparative working liquid is summarized as follows:

[0086] 1. Surface conductivity test

[0087] Surface conductivity test equipment: DC low resistance tester

[0088] Surface conductivity test method: Take the diagonal line of any sample and test its resistance five times, and take the average value.

[0089] Table 1 Surface resistance of the embodiments of the present invention and the comparative examples

[0090] Case 1 2 3 4 5 Example 1 0.102mΩ 0.089mΩ 0.108mΩ 0.099mΩ 0.104mΩ Example 2 0.068mΩ 0.067mΩ 0.062mΩ 0.070mΩ 0.060mΩ Comparative Example 1 302mΩ 445mΩ 478mΩ 582mΩ 361mΩ Comparative Example 2 125Ω 176Ω 142Ω 135Ω 186Ω

[0091] 2. Salt spray test

[0092] Salt spray test standard: GJB150A-11

[0093] Salt spray test judgment method:

[0094] ① The time when the first eclipse occurs (accounting for 50% of the total score);

[0095] ② After 96 hours, observe the surface corrosion condition and rank them (accounting for 40% of the total score);

[0096] ③ After 96 hours, clean with 200g / L CrO3, measure the corrosion ratio, and then rank (accounting for 10% of the total score);

[0097] ④ Comprehensive judgment based on scores.

[0098] The salt spray test results of the embodiments of the present invention and the comparative examples are shown in Figure 1 , the corresponding salt spray test scores are shown in the table below.

[0099] Table 2 Salt spray test scores of the embodiments of the present invention and the comparative examples

[0100] Case ①Score ②Score ③Score Total score Example 1 100 100 100 100 Example 2 100 100 100 100 Comparative Example 1 60 55 95 61.5 Comparative Example 2 50 45 92 52.2

[0101] 3. Adhesion test

[0102] Adhesion test standard: GB / T 5210-2006 "Adhesion test of paint and clear coat by pull-off method"

[0103] Table 3 Pull-apart test results of the embodiments of the present invention and the comparative examples

[0104]

[0105] 4. Test conclusion

[0106] According to the above surface resistance test results, the surface resistance of the conductive oxide film obtained in Examples 1 and 2 of the present invention is less than 0.2 mΩ, while the surface resistance of Comparative Example 1 is several hundred milliohms, and the surface resistance of Comparative Example 2 is several hundred ohms, indicating that the conductive oxide film sealed with the high-bonding strength, salt spray-resistant, low-resistance oxide film sealing liquid of the present invention has better conductivity than the existing conductive oxide film.

[0107] The results of the salt spray test show that the conductive oxide films obtained in Examples 1 and 2 of the present invention showed no surface corrosion spots after 96 hours of salt spray exposure, while the conductive oxide films in Comparative Examples 1 and 2 began to show corrosion spots after 24 hours of salt spray exposure, and multiple corrosion spots appeared after 96 hours. This indicates that the conductive oxide films sealed with the high-bonding, salt-spray-resistant, low-resistance oxide film sealing solution of the present invention exhibit superior salt spray resistance.

[0108] From the test results of the above pulling-apart experiments, it can be seen that the destructive strength of the conductive oxide film obtained in Examples 1 and 2 of the present invention is above 15 MPa, while the destructive strength of the conductive oxide film of Comparative Examples 1 and 2 is in the range of 9 to 13 MPa, indicating that the conductive oxide film sealed with the high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid of the present invention has higher bonding strength than the existing conductive oxide film.

[0109] In summary, the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid provided by the present invention utilizes KH-550 silane coupling agent and polyvalent organic amines for complexation to form an AgOH monolayer, and then controls the baking temperature and time to finally form an Ag2O monolayer. The interaction of ethylenediamine, diethylenetriamine, phosphoric acid, pyrophosphoric acid, etc. is utilized to form a three-dimensional structural network with fewer defects. The conductive oxide film sealed with the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid of the present invention has the characteristics of high conductivity, salt-fog resistance, and excellent surface organic coating bonding. Moreover, the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid of the present invention is an aqueous sealing liquid, which has the advantages of safety, environmental protection, and ease of use.

[0110] It should be noted that, in this article, the term "comprise" or any other variation thereof is intended to cover non-exclusive inclusion, so that an article or device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements that are inherent to such article or device.

[0111] It should also 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 cause the essence of the corresponding technical solutions to deviate from the scope of the present invention.

Claims

1. A method for preparing a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid, characterized in that: The method for preparing the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid comprises the following steps: Step 1: Take 20g of KH-550 silane coupling agent, 75g of anhydrous ethanol, and 8g of purified water, stir and mix thoroughly, heat in a water bath at 60-80°C for 3-4h, and then cool to room temperature to prepare solution A; Step 2: Dissolve 10 g of pyrophosphoric acid and 5 g of phosphoric acid in 85 g of pure water to prepare Solution B. Step 3: Dissolve 10 mL of ethylenediamine and 30 mL of diethylenetriamine in 60 mL of pure water and cool to room temperature to obtain Solution C. Step 4: Add 5 g of KOH to 100 mL of a 90% C2H5OH solution to form an alkaline alcohol solution, freeze the solution to -45°C, and then slowly dropwise add 100 mL of a 5% AgNO3 solution to the alkaline alcohol solution while stirring. After the addition is complete, allow to stand at low temperature for 30 to 40 minutes, filter, and wash the precipitate with a 90% C2H5OH solution. Keep the precipitate for later use. Step 5: Mix solution A and solution C and stir evenly, and adjust the pH of the mixed solution to 6.5-7.5 with solution B to obtain solution D. Step 6: Add the precipitate obtained in step 4 to liquid D, stir rapidly at a stirring speed of 200-300 r / min for 30-40 minutes, then cool and stand for 1-2 hours, take the clarified liquid for use, and prepare a high-binding strength, salt spray-resistant, low-resistance oxide film sealing liquid.

2. A high-binding strength, salt-spray-resistant, low-resistance oxide film sealing liquid, characterized in that: The high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid is prepared by the preparation method of the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid according to claim 1.

3. A method for using a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid, wherein the high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid is prepared by the method for preparing a high-binding strength, salt-fog-resistant, low-resistance oxide film sealing liquid according to claim 1, characterized in that: The method for using the high-bonding strength, salt-fog-resistant, low-resistance oxide film sealing liquid comprises: Spraying a high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid directly onto the surface of the golden conductive oxide film of the magnesium alloy plate, leveling it at room temperature for 10 to 20 minutes, placing it in an oven and baking it in multiple steps, and then cooling it to room temperature with the oven, wherein the multiple step baking sequence includes: baking at 50°C for 15 minutes, baking at 70°C for 10 minutes, baking at 120°C for 10 minutes, and baking at 200°C for 15 minutes; or The high-bonding strength, salt-spray-resistant, low-resistance oxide film sealing liquid is diluted 5 to 8 times by volume with pure water, and a magnesium alloy plate prepared with a golden conductive chemical oxide film is immersed in the diluted sealing liquid and vibrated with 50W ultrasonic waves for 1 to 3 minutes. After being taken out of the bath, it is leveled at room temperature for 5 to 10 minutes, and then rinsed with pure water for 1 to 5 minutes. The water droplets hanging on the surface of the magnesium alloy plate are blown dry with dry high-pressure air. After evaporation at room temperature for 10 to 15 minutes, it is baked in an oven in multiple steps and then cooled to room temperature with the furnace. The multiple step-by-step baking sequence includes: baking at 90°C for 10 minutes, baking at 150°C for 10 minutes, and baking at 250°C for 10 minutes.

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