Corrosion inhibitor coated GO-Al-based composite coating resistant to pitting corrosion and preparation method and application of corrosion inhibitor coated GO-Al-based composite coating
By forming an in-situ graphene oxide network structure on the surface of aluminum powder and electrostatically adsorbing cationic corrosion inhibitors, a corrosion inhibitor@GO-Al based composite coating was prepared. This solved the problem of poor particle interface density in aluminum-based coatings, realized a multi-protection mechanism for the coating, and significantly improved the pitting corrosion resistance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG UNIV OF TECH
- Filing Date
- 2026-04-15
- Publication Date
- 2026-05-15
AI Technical Summary
Cold-sprayed aluminum-based coatings suffer from poor particle interface density, leading to decreased corrosion resistance. Furthermore, the corrosion inhibitor cannot be evenly dispersed in the coating, affecting its pitting corrosion resistance.
Modified aluminum powder was in situ coated with graphene oxide and cationic corrosion inhibitors. A corrosion inhibitor@GO-Al based composite coating was formed on the surface of a magnesium alloy substrate by cold spraying technology. Electrostatic adsorption was used to make the corrosion inhibitor uniformly dispersed and deposited inside the coating.
It improves the shielding and passivation properties of aluminum-based coatings, significantly reduces the corrosion rate, and enhances the coating's resistance to pitting corrosion.
Smart Images
Figure CN122039043A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of metal material surface corrosion protection technology, and more specifically, relates to a pitting corrosion inhibitor @GO-Al based composite coating, its preparation method and application. Background Technology
[0002] Cold spraying is an important method for preparing metal-based composite coatings. It accelerates metal powder to a critical deposition rate, causing it to be deposited onto a substrate surface through plastic deformation to form a robust metal-based coating. Low-pressure cold spraying is characterized by simple equipment, convenient operation, high efficiency, and ease of use, and can be widely used to prepare aluminum-based, copper-based, and zinc-based coatings. However, cold-sprayed metal-based coatings exhibit particle interfaces and slightly lower density, leading to reduced corrosion resistance.
[0003] Aluminum-based coatings are important protective coatings for metals such as steel and magnesium alloys. However, they are prone to pitting corrosion, which affects their lifespan. Common improvement measures include alloying or adding two-dimensional materials to enhance anodic polarization and improve the pitting potential or shielding performance of the coating. Cold-sprayed aluminum-based coatings often combine subsequent heat treatment to reduce the particle interface and improve corrosion resistance, but this increases production costs. Further design of aluminum-based coating composition from the perspective of corrosion mechanism is needed to improve the coating's corrosion resistance. Corrosion inhibitors are a low-cost, high-efficiency metal corrosion protection technology. They are typically added to the corrosive medium to dynamically form a protective isolation film in situ at the corrosion interface, or added as fillers to organic coatings. For cold-sprayed coatings, the presence of corrosion inhibitors prevents the powder from successfully depositing into a coating. Therefore, appropriate methods are needed to uniformly disperse corrosion inhibitors in the aluminum-based coating to improve its corrosion resistance. Summary of the Invention
[0004] To address the shortcomings and drawbacks of the existing technology, the primary objective of this invention is to provide a pitting corrosion inhibitor @GO-Al based coating. This composite coating possesses shielding, passivation, and corrosion inhibition properties, representing an improvement over Al coatings and overcoming their disadvantages.
[0005] Another object of the present invention is to provide a method for preparing the above-mentioned pitting corrosion inhibitor @GO-Al based coating. This method employs cold spraying to in-situ coat modified aluminum powder with graphene oxide and the corrosion inhibitor to prepare the corrosion inhibitor @GO-Al based composite coating.
[0006] Another object of the present invention is to provide the application of the above-mentioned pitting corrosion inhibitor @GO-Al based coating. This corrosion inhibitor @GO-Al based coating is suitable for surface corrosion protection of a variety of metal substrates, providing long-term and effective corrosion protection for a variety of active metals.
[0007] The objective of this invention is achieved through the following technical solution: A pitting corrosion inhibitor-based composite coating is a cationic corrosion inhibitor-graphene oxide-aluminum-based composite coating. The process involves adding aluminum powder to an aqueous solution of graphene oxide and ultrasonically dispersing it until the supernatant is clear. Then, aluminum powder is added to an aqueous solution of the cationic corrosion inhibitor and ultrasonically dispersed again. After settling, the mixture is filtered, washed, and vacuum dried to obtain composite modified aluminum powder. The composite modified aluminum powder and alumina powder are mixed evenly to obtain a mixed powder. A magnesium alloy substrate is sandblasted with silicon carbide under a pressure of 0.6~0.8 MPa to obtain a pretreated magnesium alloy substrate. The mixed powder is then cold-sprayed onto the surface of the pretreated magnesium alloy substrate to obtain the final product.
[0008] Preferably, the mass concentration of the graphene oxide aqueous solution is 0.05~0.15 wt%; the mass concentration of the cationic corrosion inhibitor aqueous solution is 5~15 wt%; the cationic corrosion inhibitor is heptadecanylamine ethyl imidazoline quaternary ammonium salt (ODD), hexadecyltrimethylammonium bromide or hexadecylpyridine chloride; the mass ratio of the spherical aluminum powder, the volume of the graphene oxide aqueous solution and the volume ratio of the cationic corrosion inhibitor aqueous solution is (80~100) g: (80~120) mL: (1~3) mL.
[0009] Preferably, the mass ratio of the composite modified aluminum powder to the alumina powder is (3~5):1.
[0010] The method for preparing the pitting corrosion inhibitor @GO-Al based composite coating includes the following steps: S1. Aluminum powder is added to a multilayer graphene oxide aqueous solution and ultrasonically dispersed until the upper layer is clear. Then, it is added to a cationic corrosion inhibitor aqueous solution and ultrasonically dispersed. After standing and settling, it is filtered, washed and vacuum dried to obtain composite modified aluminum powder. S2. Mix the composite modified aluminum powder and alumina powder evenly to obtain a mixed powder; S3. Under a pressure of 0.6~0.8MPa, the magnesium alloy matrix is sandblasted with silicon carbide to obtain a pretreated magnesium alloy matrix; S4. The mixed powder is cold-sprayed onto the surface of the pretreated magnesium alloy substrate to obtain a cationic corrosion inhibitor@graphene oxide-Al-based composite coating, abbreviated as corrosion inhibitor@GO-Al-based composite coating.
[0011] Preferably, the ultrasonic dispersion time in step S1 is 20-40 min, and the vacuum drying temperature is 60-100℃.
[0012] Preferably, the silicon carbide in step S3 has a particle size of 2.5~5μm; and the surface roughness (Ra) of the pretreated magnesium alloy substrate is 1~3μm.
[0013] Preferably, the parameters for cold spraying in step S4 are: spray gun pressure of 0.6~0.8 MPa, working temperature of 250~450 ℃, nozzle moving speed of 300~500 mm / min, powder supply rate of 50~700 g / min, and spraying distance of 10~25 mm.
[0014] The application of the aforementioned pitting corrosion inhibitor @GO-Al based composite coating in the field of metal surface corrosion resistance.
[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention first forms an in-situ graphene oxide network structure on the surface of aluminum powder by reacting it in situ, so that the powder surface has negative charge. Then, the cationic corrosion inhibitor in the solution is adsorbed onto the surface of the aluminum powder by electrostatic adsorption, so that the corrosion inhibitor is evenly dispersed into the interior of the aluminum base coating.
[0016] 2. The aluminum powder modified by GO and corrosion inhibitor of the present invention has a good deposition rate during cold spraying. The deposition of GO and corrosion inhibitor modified aluminum powder on the substrate surface is achieved by cold spraying technology, and the coating thickness is controllable.
[0017] 3. The corrosion inhibitor @GO-Al based composite coating of the present invention has multiple protection mechanisms: first, the passivation film protection of aluminum; second, the shielding performance of graphene; and third, the adsorption film formed on the coating surface by the in-situ release of the corrosion inhibitor during the corrosion process has excellent corrosion inhibition performance. Attached Figure Description
[0018] Figure 1 The polarization behavior of different coatings in 3.5 wt% NaCl solution for Example 1 and Comparative Examples 1-2; Figure 2 The surface morphology of different coatings in Example 1 and Comparative Examples 1-2 after being fully immersed in 3.5 wt% NaCl solution for 240 h for corrosion. Figure 3 The cross-sectional morphology of different coatings from Examples 1 and Comparative Examples 1-2 after being fully immersed in 3.5 wt% NaCl solution for 360 h for corrosion is shown. Detailed Implementation
[0019] The present invention will be further described below with reference to specific embodiments, but these should not be construed as limiting the invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.
[0020] Example 1 1. 100g of spherical aluminum powder (particle size 15~53μm) was added to 100mL of graphene oxide (GO) aqueous solution (0.1wt%, light brown) and ultrasonically dispersed for 30min until the solution became clear. Then, 1mL of cationic corrosion inhibitor heptadecanylamine ethyl imidazoline quaternary ammonium salt (ODD) aqueous solution (10wt%, light yellow) was added and ultrasonically dispersed for 30min until the yellow solution became lighter. After standing and settling, the mixture was filtered and washed three times with anhydrous ethanol. The resulting powder was dried in a vacuum drying oven at 80℃ for 24h to obtain ODD and GO composite modified aluminum powder. 2. Mix ODD and GO composite modified aluminum powder and alumina powder (average particle size 35μm) in a mass ratio of 4:1 with mechanical stirring for 30 minutes to obtain a mixed powder; 3. Under a pressure of 0.7 MPa, the magnesium alloy substrate was sandblasted with silicon carbide with a particle size of 3 μm, so that the cleanliness level Sa of the metal substrate surface reached 2.5 and its surface roughness (Ra) was 1~3 μm. 4. Add the mixed powder to the powder supply cylinder of the cold spraying machine, and adjust the parameters of the cold spraying equipment: spray gun pressure 0.7MPa, working temperature 300℃, nozzle moving speed 400 mm / min, powder supply rate 60 g / min, and spraying distance 20 mm; run the machine to spray on the sandblasted magnesium alloy substrate surface to obtain an ODD@GO-Al based composite coating with a thickness of 150μm.
[0021] Comparative Example 1 1. Mix spherical aluminum powder (particle size 15~53μm) and alumina powder (average particle size 35μm) in a mass ratio of 4:1 using mechanical stirring for 30 minutes to obtain a mixed powder.
[0022] 2. Under a pressure of 0.7 MPa, the magnesium alloy substrate was sandblasted with silicon carbide with a particle size of 3 μm, so that the cleanliness level Sa of the metal substrate surface reached 2.5 and its surface roughness (Ra) was 1~3 μm.
[0023] 3. Add the mixed powder to the powder supply cylinder of the cold spraying machine, and adjust the parameters of the cold spraying equipment: spray gun pressure 0.7MPa, working temperature 300℃, nozzle moving speed 400 mm / min, powder supply rate 60 g / min, and spraying distance 20 mm; run the machine to spray on the sandblasted magnesium alloy substrate to obtain an aluminum coating with a thickness of 160μm.
[0024] Comparative Example 2 1. 100 g of spherical aluminum powder (particle size 15~53 μm) was added to 100 mL of GO aqueous solution (0.1 wt%, light brown) and ultrasonically dispersed for 30 min until the solution became clear. After standing and precipitation, the powder was filtered, washed three times with anhydrous ethanol, and dried in a vacuum drying oven at 80 °C for 24 h to obtain graphene-modified aluminum powder. 2. Graphene-modified aluminum powder and alumina powder (average particle size 35 μm) in a mass ratio of 4:1 were mechanically stirred for 30 min to obtain a mixed powder. 3. Under a pressure of 0.7 MPa, the magnesium alloy substrate was sandblasted with silicon carbide with a particle size of 3 μm, so that the cleanliness level Sa of the metal substrate surface reached 2.5 and its surface roughness (Ra) was 1~3 μm. 4. Add the mixed powder to the powder supply cylinder of the cold spraying machine, and adjust the parameters of the cold spraying equipment: spray gun pressure 0.7MPa, working temperature 300℃, nozzle moving speed 400 mm / min, powder supply rate 60 g / min, and spraying distance 20 mm; run the machine to spray on the sandblasted magnesium alloy substrate surface to obtain a GO-Al composite coating with a thickness of 120μm.
[0025] Figure 1 The polarization behavior of different coatings in Example 1 and Comparative Examples 1-2 in 3.5 wt% NaCl solution is shown. The aluminum coating of Comparative Example 1 exhibits a low self-corrosion potential and a relatively high self-corrosion current density, indicating poor corrosion resistance. Compared to the aluminum coating, the self-corrosion potential of the GO-Al based composite coating in Comparative Example 2 shifted positively by 150 mV, indicating a reduced tendency for electrochemical corrosion, but the self-corrosion current density increased by 50%, indicating an increased corrosion rate. In contrast, the polarization behavior of the ODD@GO-Al based composite coating in Example 1 in 3.5 wt% NaCl solution, compared to the aluminum coating, shows a positive shift in the self-corrosion potential of the ODD@GO-Al based composite coating by 280 mV, indicating a reduced tendency for electrochemical corrosion, and a 50% decrease in the self-corrosion current density, indicating a significant decrease in corrosion rate. Figure 2 The surface morphology of different coatings from Examples 1 and Comparative Examples 1-2 after immersion corrosion in 3.5 wt% NaCl solution for 240 h is shown. Specifically, (a) is the aluminum coating in Comparative Example 1, (b) is the GO-Al composite coating in Comparative Example 2, and (c) is the ODD@GO-Al composite coating in Example 1. Figure 2As can be seen, compared with the aluminum coating of Comparative Example 1, the GO-Al coating of Comparative Example 2 did not show severe corrosion or accumulation of corrosion products, but pitting corrosion did occur. In contrast, the ODD@GO-Al based composite coating of Example 1, after being fully immersed in 3.5wt% NaCl solution for 240 hours, did not show severe corrosion or accumulation of corrosion products on its surface, and the localized pitting corrosion did not develop into deep pores due to the action of the corrosion inhibitor. The aluminum coating of Comparative Example 1 showed severe accumulation of corrosion products, slightly poor coating density, gaps between particles, and poor corrosion resistance. Figure 3 The cross-sectional morphology of different coatings from Examples 1 and Comparative Examples 1-2 after immersion corrosion in 3.5 wt% NaCl solution for 360 h is shown. (a) is the aluminum coating in Comparative Example 1, (b) is the GO-Al composite coating in Comparative Example 2, and (c) is the ODD@GO-Al composite coating in Example 1. Figure 3 It can be seen that after immersion corrosion in 3.5% NaCl solution for 360 hours, the aluminum coating in Comparative Example 1 showed severe damage at the corrosion points on its cross-section, with corrosion reaching the magnesium substrate, indicating a short protective lifespan for the surface-applied aluminum coating. After immersion corrosion in 3.5% NaCl solution for 360 hours, the GO-Al composite coating in Comparative Example 2 showed no obvious longitudinal corrosion on its cross-section, but the pitting corrosion was more severe than that of the coating in Example 1. After immersion corrosion in 3.5 wt% NaCl solution for 360 hours, the ODD@GO-Al based composite coating in Example 1 showed no obvious longitudinal corrosion on its cross-section, indicating excellent pitting corrosion resistance.
[0026] Example 2 1. Add 100g of spherical aluminum powder (particle size 15~53μm) to 100mL of GO aqueous solution (0.05wt%, light brown), and ultrasonically disperse for 30min until clear. Then add 1mL of ODD aqueous solution (5wt%, light yellow), and ultrasonically disperse for 25min until the yellow solution becomes lighter. After standing and settling, filter, wash three times with anhydrous ethanol, and dry in a vacuum drying oven at 70℃ for 24h to obtain ODD and GO composite modified aluminum powder; 2. Mix ODD and GO composite modified aluminum powder and alumina powder (average particle size 35μm) in a mass ratio of 5:1 with mechanical stirring for 25 minutes to obtain a mixed powder; 3. Under a pressure of 0.7 MPa, the magnesium alloy substrate was sandblasted with silicon carbide with a particle size of 3 μm, so that the cleanliness level Sa of the metal substrate surface reached 2.5 and its surface roughness (Ra) was 1~3 μm. 4. Add the mixed powder to the powder supply cylinder of the cold spraying machine, and adjust the parameters of the cold spraying equipment: spray gun pressure 0.7MPa, working temperature 350℃, nozzle moving speed 350 mm / min, powder supply rate 70 g / min, and spraying distance 20 mm; run the machine to spray on the sandblasted magnesium alloy substrate surface to obtain an ODD@GO-Al based composite coating with a thickness of 250μm.
[0027] The polarization behavior of the ODD@GO-Al based composite coating in 3.5wt% NaCl solution in this embodiment, compared with the aluminum coating in Comparative Example 1, shows a 160mV positive shift in the self-corrosion potential and a 30% decrease in the self-corrosion current density, indicating a significant reduction in corrosion rate. The corrosion morphology of the ODD@GO-Al based composite coating after 360 hours of full immersion corrosion in 3.5wt% NaCl solution shows relatively mild surface corrosion, indicating that the ODD@GO-Al based composite coating is dense and possesses excellent pitting corrosion resistance.
[0028] Example 3 1. Add 100g of spherical aluminum powder (particle size 15~53μm) to 100mL of GO aqueous solution (concentration 0.15wt%, light brown), and ultrasonically disperse for 30min until clear. Then add 1mL of ODD aqueous solution (concentration 15wt%, light yellow), and ultrasonically disperse for 35min until the yellow solution becomes lighter. After standing and settling, filter, wash three times with anhydrous ethanol, and dry in a vacuum drying oven at 90℃ for 24h to obtain ODD and GO composite modified aluminum powder.
[0029] 2. Mix ODD and GO composite modified aluminum powder and alumina powder (average particle size 35μm) in a mass ratio of 3:1 with mechanical stirring for 35 minutes to obtain a mixed powder.
[0030] 3. Under a pressure of 0.7 MPa, the magnesium alloy substrate is sandblasted with silicon carbide with a particle size of 3 μm, so that the cleanliness level Sa of the metal substrate surface reaches 2.5 and its surface roughness (Ra) is 1~3 μm.
[0031] 4. Add the mixed powder to the powder supply cylinder of the cold spraying machine, and adjust the parameters of the cold spraying equipment: spray gun pressure 0.7MPa, working temperature 400℃, nozzle moving speed 450 mm / min, powder supply rate 50 g / min, and spraying distance 20 mm; run the machine to spray on the sandblasted magnesium alloy substrate surface to obtain an ODD@GO-Al based composite coating with a thickness of 120μm.
[0032] The polarization behavior of the ODD@GO-Al based composite coating in 3.5 wt% NaCl solution in this embodiment, compared with the aluminum coating in Comparative Example 1, shows a 100 mV positive shift in the self-corrosion potential and a 20% decrease in the self-corrosion current density, indicating a reduction in the corrosion rate. The corrosion morphology of the ODD@GO-Al based composite coating after 360 hours of full immersion corrosion in 3.5 wt% NaCl solution shows relatively mild surface corrosion, with only slight pitting. This indicates that the ODD@GO-Al based composite coating is relatively dense and has good resistance to pitting corrosion.
[0033] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A pitting corrosion inhibitor @GO-Al based composite coating, characterized in that, The corrosion inhibitor@GO-Al based composite coating is a cationic corrosion inhibitor@graphene oxide-aluminum based composite coating. It is prepared by adding aluminum powder to an aqueous solution of graphene oxide and ultrasonically dispersing it until the supernatant is clear. Then, aluminum powder is added to an aqueous solution of the cationic corrosion inhibitor and ultrasonically dispersed. After settling, the mixture is filtered, washed, and vacuum dried to obtain composite modified aluminum powder. The composite modified aluminum powder and alumina powder are mixed evenly to obtain a mixed powder. A magnesium alloy substrate is sandblasted with silicon carbide under a pressure of 0.6~0.8 MPa to obtain a pretreated magnesium alloy substrate. The mixed powder is then cold-sprayed onto the surface of the pretreated magnesium alloy substrate to obtain the final product.
2. The pitting-resistant corrosion inhibitor @GO-Al based composite coating according to claim 1, characterized in that, The mass concentration of the graphene oxide aqueous solution is 0.05~0.15 wt%; the mass concentration of the cationic corrosion inhibitor aqueous solution is 5~15 wt%; the cationic corrosion inhibitor is heptadecanylamine ethyl imidazoline quaternary ammonium salt, hexadecyltrimethylammonium bromide or hexadecylpyridine chloride; the mass ratio of the aluminum powder, the volume of the graphene oxide aqueous solution and the volume ratio of the cationic corrosion inhibitor aqueous solution is (80~100) g: (80~120) mL: (1~3) mL.
3. The pitting-resistant corrosion inhibitor @GO-Al based composite coating according to claim 1, characterized in that, The mass ratio of the composite modified aluminum powder to alumina powder is (3~5):
1.
4. The method for preparing the pitting-resistant corrosion inhibitor @GO-Al based composite coating according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Aluminum powder is added to a multilayer graphene oxide aqueous solution and ultrasonically dispersed until the upper layer is clear. Then, it is added to a cationic corrosion inhibitor aqueous solution and ultrasonically dispersed. After standing and settling, it is filtered, washed and vacuum dried to obtain composite modified aluminum powder. S2. Mix the composite modified aluminum powder and alumina powder evenly to obtain a mixed powder; S3. Under a pressure of 0.6~0.8MPa, the magnesium alloy matrix is sandblasted with silicon carbide to obtain a pretreated magnesium alloy matrix; S4. The mixed powder is cold-sprayed onto the surface of the pretreated magnesium alloy substrate to obtain a cationic corrosion inhibitor@graphene oxide-Al-based composite coating, abbreviated as corrosion inhibitor@GO-Al-based composite coating.
5. The method for preparing the pitting-resistant corrosion inhibitor @GO-Al based composite coating according to claim 4, characterized in that, The ultrasonic dispersion time in step S1 is 20~40 min, and the vacuum drying temperature is 60~100℃.
6. The method for preparing the pitting-resistant corrosion inhibitor @GO-Al based composite coating according to claim 4, characterized in that, The silicon carbide in step S3 has a particle size of 2.5~5μm; the surface roughness of the pretreated magnesium alloy matrix is 1~3μm.
7. The method for preparing the pitting-resistant corrosion inhibitor @GO-Al based composite coating according to claim 4, characterized in that, The parameters for cold spraying in step S4 are: spray gun pressure of 0.6~0.8 MPa, working temperature of 250~450 ℃, nozzle moving speed of 300~500 mm / min, powder supply rate of 50~700 g / min, and spraying distance of 10~25 mm.
8. The application of the pitting corrosion inhibitor @GO-Al based composite coating according to any one of claims 1-3 in the field of corrosion resistance on metal surfaces.