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CN-121976188-A - ZK61M magnesium alloy surface modified corrosion-resistant coating and preparation method thereof

CN121976188ACN 121976188 ACN121976188 ACN 121976188ACN-121976188-A

Abstract

The invention relates to a ZK61M magnesium alloy surface modified corrosion-resistant coating and a preparation method thereof. The preparation method of the ZK61M magnesium alloy surface modified corrosion-resistant coating comprises the following steps of (1) adding Al salt and Na salt into a solution containing a chelating agent and regulating the pH value to obtain a reaction solution, (2) placing the pretreated ZK61M magnesium alloy into the reaction solution and carrying out hydrothermal coprecipitation reaction to obtain an MgAl-LDH coating, and (3) placing the ZK61M magnesium alloy with the MgAl-LDH coating into a solution containing corrosion inhibition anions to carry out water bath anion intercalation and modification reaction to obtain the ZK61M magnesium alloy surface modified corrosion-resistant coating.

Inventors

  • YU YUN
  • CHEN MENGHAN
  • YU YANG
  • MI LE
  • FENG AIHU
  • CHEN JUNGE
  • LIU KUN

Assignees

  • 中国科学院上海硅酸盐研究所

Dates

Publication Date
20260505
Application Date
20260115

Claims (8)

  1. 1. The preparation method of the ZK61M magnesium alloy surface modified corrosion-resistant coating is characterized by comprising the following steps of: (1) Adding Al salt and Na salt into a solution containing a chelating agent and regulating the pH value to obtain a reaction solution; (2) Placing the pretreated ZK61M magnesium alloy into the reaction solution and performing hydrothermal coprecipitation reaction to obtain an MgAl-LDH coating; (3) And placing the ZK61M magnesium alloy with the MgAl-LDH coating in a solution containing corrosion inhibition anions to perform water bath anion intercalation and modification reaction to obtain the ZK61M magnesium alloy surface modified corrosion-resistant coating.
  2. 2. The method of claim 1, wherein in step (1), the Al salt comprises Al (NO 3 ) 3 ·9H 2 O), the Na salt comprises NaNO 3 , and the chelating agent comprises EDTA.
  3. 3. The production method according to claim 1 or 2, wherein in the step (1), the concentration of Al salt is 0.05 to 0.1 m, the concentration of na salt is 0.2 to 0.3M, and the concentration of chelating agent is 0.01 to 0.1M in the reaction solution.
  4. 4. A process according to any one of claims 1 to 3, wherein in step (1) the pH of the reaction solution is 9 to 11.
  5. 5. The process according to any one of claims 1 to 4, wherein in step (2), the hydrothermal coprecipitation reaction is carried out at a temperature of 80 to 100 ℃ for a time of 20 to 30 h.
  6. 6. The method according to any one of claims 1 to 5, wherein in step (3), the solution containing a corrosion inhibitor anion comprises a Na 3 VO 4 、Na 3 PO 4 ·12H 2 O、Na 2 MoO 4 、Na 2 SO 4 、NaCl solution, preferably the concentration of the anion in the solution containing a corrosion inhibitor anion is 0.1 to 0.5M.
  7. 7. The process according to any one of claims 1 to 6, wherein in step (3), the temperature of the reaction between the intercalation of the anions in the water bath and the modification is 50 to 95 ℃, the time is 6 to 24 hours, and the ph is 7 to 13.
  8. 8. A ZK61M magnesium alloy surface modified corrosion resistant coating obtainable according to the method of any one of claims 1-7.

Description

ZK61M magnesium alloy surface modified corrosion-resistant coating and preparation method thereof Technical Field The invention belongs to the technical field of preparation of corrosion-resistant coatings on alloy surfaces, and particularly relates to a ZK61M magnesium alloy surface modified corrosion-resistant coating and a preparation method thereof. Background Magnesium zinc alloy (ZK 61M) is an ideal choice for lightweight design in the aerospace field by virtue of low density, high specific strength and excellent thermal stability. However, the magnesium alloy is easy to corrode in various media due to the high electrochemical activity, and the magnesium oxide film formed on the surface is loose and poor in compactness and cannot play a role in resisting corrosion. In order to remarkably improve the corrosion resistance of the magnesium alloy, break through the application limit of the magnesium alloy in a severe environment due to high chemical activity, and effectively carry out surface modification and protection treatment on the magnesium alloy, so that the magnesium alloy has become a key way for expanding the engineering application field of the magnesium alloy. Although the traditional surface treatment method can improve the corrosion resistance of magnesium alloy to a certain extent, the traditional surface treatment method often has the problems of poor adhesive force, difficult operation, easy falling of coating and the like. In contrast, layered Double Hydroxide (LDHs) coatings, with their unique two-dimensional layered structure and excellent properties, are able to form a dense physical barrier that blocks erosion of the substrate by the corrosive medium, thereby providing more reliable protection. But generally, the layered double hydroxide coating is generated in a high-temperature and high-pressure reaction kettle, and the method has the advantages of high energy consumption, complex process and limitation of preparing the large-size magnesium alloy surface coating. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a ZK61M magnesium alloy surface modified corrosion-resistant coating and a preparation method thereof, the preparation method is simple to operate, and the prepared coating has excellent corrosion resistance and can be beneficial to realizing high-efficiency and long-term protection of magnesium alloy. In a first aspect, the invention provides a preparation method of a ZK61M magnesium alloy surface modified corrosion-resistant coating, which comprises the following steps: (1) Adding Al salt and Na salt into a solution containing a chelating agent and regulating the pH value to obtain a reaction solution; (2) Placing the pretreated ZK61M magnesium alloy into the reaction solution and performing hydrothermal coprecipitation reaction to obtain an MgAl-LDH coating; (3) And placing the ZK61M magnesium alloy with the MgAl-LDH coating in a solution containing corrosion inhibition anions to perform water bath anion intercalation and modification reaction to obtain the ZK61M magnesium alloy surface modified corrosion-resistant coating. Preferably, in step (1), the Al salt comprises Al (NO 3)3·9H2 O), the Na salt comprises NaNO 3, and the chelating agent comprises ethylenediamine tetraacetic acid EDTA. Preferably, in the step (1), the concentration of the Al salt in the reaction solution is 0.05-0.1M, the concentration of the Na salt is 0.2-0.3M, and the concentration of the chelating agent is 0.01-0.1M. Preferably, in step (1), the pH of the reaction solution is 9-11. Preferably, in the step (2), the temperature of the hydrothermal coprecipitation reaction is 80-100 ℃ and the time is 20-30 h. Preferably, in the step (3), the solution containing the corrosion inhibitor anions comprises Na3VO4、Na3PO4·12H2O、Na2MoO4、Na2SO4、NaCl solution, and preferably, the concentration of the anions in the solution containing the corrosion inhibitor anions is 0.1-0.5M. Preferably, in the step (3), the temperature of the water bath anion intercalation and the modification reaction is 50-95 ℃, the time is 6-24h, and the pH is 7-13. In a second aspect, the invention provides a ZK61M magnesium alloy surface modified corrosion-resistant coating obtained according to the preparation method. Advantageous effects (1) The modified MgAl-LDH coating provided by the invention has excellent corrosion resistance, and the grown coating has strong binding force with magnesium alloy; (2) The corrosion-resistant coating is prepared by the in-situ coprecipitation assisted by the magnesium alloy substrate chelating agent, and then the coating is modified by anions with corrosion inhibition, so that the high-pressure condition is not needed, the energy consumption is reduced, the preparation process is simple and easy to operate, the cost is low, the environment is protected, and the possibility of wide application is realized; (3) The invention is based on the characteristic of