CN118271881B - Magnesium alloy anti-corrosion ceramic slurry and application thereof - Google Patents

Abstract

The present invention belongs to the technical field of ceramic slurry, and specifically relates to a magnesium alloy anticorrosive ceramic slurry and its application. The magnesium alloy ceramic slurry includes ceramic aggregate, adhesive, additive, and water. The ceramic aggregate is selected by mass percentage to include: _{Al2O3 29} ~33%, MgO 29 _~ 31%, SiO2 ₂₉ ~31%, _CeO2 5~8%; the adhesive contains γ-glycidyloxypropyltrimethoxysilane and sodium silicate; the additive includes _Na2SiF6 . The preparation method is: firstly prepare the ceramic aggregate components according to the designed components and grind them, then prepare the adhesive and add the ground ceramic aggregate powder to make a slurry; then uniformly introduce _Na2SiF6 into the slurry and coat it on the magnesium alloy substrate, and dry it; and obtain _a magnesium alloy anticorrosive coating. The coating components of the present invention are reasonably designed, the preparation process is simple and controllable, the obtained product has excellent performance, and is convenient for industrial application.

Description

A magnesium alloy anticorrosive ceramic slurry and its application

Technical Field

The invention belongs to the technical field of ceramic slurries, and in particular relates to a magnesium alloy anti-corrosion ceramic slurry and application thereof.

Background Art

Magnesium alloys have the advantages of high specific strength, good vibration damping, thermal conductivity and electromagnetic shielding ability, and have great potential for application in automobiles, 3C industry, rail transportation, aerospace, and lightweight weapons and equipment. Magnesium alloys also have low density, high specific strength, specific stiffness, and damping tolerance, and have good application value in the aerospace field. However, the natural corrosion potential of magnesium alloys is extremely low and they are very susceptible to corrosion. The corrosion resistance of magnesium alloys is even worse in humid climates, which limits their application in industrial products. So people began to try to prepare coatings on the surface of magnesium alloys. Among the existing coatings, polymer coatings have relatively excellent performance. Polymer coatings are widely used as a corrosion protection method with simple process and significant performance. As a physical barrier layer, it can effectively resist the attack of harmful species such as acids, alkalis and salt ions, thereby effectively improving the corrosion resistance of magnesium alloys. For example, in patent application CN117567892A, a magnesium alloy anticorrosive coating is provided, including: 30-50 g/L magnesium alloy corrosion inhibitor, 50-80 g/L varnish, 10-15 g/L leveling agent, 5-10 g/L wetting agent and 5-20 g/L defoaming agent. The magnesium alloy corrosion inhibitor is a compound of an inorganic corrosion inhibitor and an organic corrosion inhibitor; wherein the inorganic corrosion inhibitor includes: sodium dihydrogen phosphate, anhydrous sodium sulfate and cerium nitrate, and the concentration of the inorganic corrosion inhibitor is 10-30 g/L; the organic corrosion inhibitor includes: 1-butyl-3-methylimidazole hexafluorophosphate, 1-butyl-3-methylimidazole tetrafluoroborate, barbituric acid, benzotriazole and methionine, and the concentration of the organic corrosion inhibitor is 10-40 g/L. The leveling agent is one or more of diacetone alcohol, trimethylbenzene and N,N-dimethylformamide; the wetting agent is one or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium dodecyl sulfonate and sodium lauryl sulfate; the defoaming agent is one or more of trialkyl melamine, fatty acid glyceride and polymerized propylene oxide. Patent application CN116239906A discloses a preparation method and application of a conductive anti-corrosion coating for magnesium alloy bipolar plates, and the method comprises the following steps:

S1, mixing a conductive polymer, a binder and an organic solvent to obtain a coating;

S2. Apply the paint on the surface of the magnesium alloy to form a coating.

The conductive high molecular polymer is selected from at least one of polyaniline, polypyrrole and polythiophene, for example, polyaniline.

The binder is selected from at least one of polyvinylidene fluoride, polyacrylonitrile, polyethersulfone, vinyl acetate copolymer, and polyethylene terephthalate. Preferably, the binder is selected from polyvinylidene fluoride or polyacrylonitrile.

The organic solvent is selected from at least one of xylene, N-methylpyrrolidone, tetrahydrofuran, and dimethylformamide. For example, the organic solvent is selected from N-methylpyrrolidone.

It can be seen that, up to now, there has been no report on the development and preparation of high-quality magnesium alloy anticorrosion ceramic slurry using γ-glycidyloxypropyltrimethoxysilane as an organic component in combination with inorganic oxides and fluorosilicates.

Summary of the invention

In view of the shortcomings of the prior art, the present invention proposes a magnesium alloy anti-corrosion ceramic slurry and its application. The ceramic slurry has a low curing temperature and is well suited for low-melting-point magnesium alloys. At the same time, a proper amount of organic matter is added to the inorganic matter to obtain a composite coating with fewer defects, thereby improving corrosion resistance and wear resistance, and has the advantages of simple preparation process and low cost.

The present invention attempts for the first time to develop and prepare high-quality magnesium alloy anticorrosive ceramic slurry by using γ-glycidyloxypropyltrimethoxysilane as an organic component in combination with an inorganic binder and fluorosilicate.

The present invention discloses a magnesium alloy anticorrosive ceramic slurry, which comprises ceramic aggregate, a binder, an additive and water. The ceramic aggregate comprises, by mass percentage, 29-33% Al ₂ O ₃ , 29-31% MgO, 29-31% SiO ₂ , and 5-8% CeO ₂ ;

The additive includes Na ₂ SiF ₆ ;

In the magnesium alloy ceramic slurry, the mass percentage of water is 15-25%;

By mass ratio, ceramic aggregate: binder = 1:0.5~1;

The binder is composed of an organic binder and an inorganic binder, wherein the inorganic binder accounts for 80% to 95% of the total mass of the binder, and the balance is an organic binder, wherein the organic binder is γ-glycidyloxypropyltrimethoxysilane (GPTMS), and the inorganic binder is sodium silicate;

The amount of additive added is 6~8% of the mass of ceramic aggregate.

In the present invention, MgO can not only play a certain curing role, but also help reduce the risk of cracking of the coating in the use environment. When the content of MgO in the coating is 20-25%, the coating will partially fall off after being immersed in a 3.5% NaCl solution for two days, indicating that the degree of curing of the coating is low. Further increasing the content of MgO can improve the degree of curing of the coating. When the content of MgO in the coating is 35-40%, the hardness of MgO is low (Mohs hardness 5) and it is brittle, which causes the coating to crack and fall off easily in the friction and wear experiment. Therefore, the content of MgO is finally determined to be 29%-31%.

Since _SiO2 and sodium silicate have the same elements and hydrolysis behavior, an appropriate amount of _SiO2 is beneficial to improve the cohesive strength of the coating and reduce the microscopic defects of the coating, such as microcracks and holes. When the coating contains more _SiO2 , the viscosity is high, resulting in poor slurry fluidity, difficulty in self-leveling, and uneven slurry dispersion. The curing rate of different parts of the coating is different. Therefore, the coating surface is rough and accompanied by many cracks.

In the present invention, the rare earth compound can act as a corrosion inhibitor, improve coating defects, and slow down the corrosion rate of the metal. The present invention adds a small amount of CeO ₂ (such as 7-9%), which can not only improve the corrosion resistance, but also improve the wear resistance of the coating.

As a further preferred embodiment, the present invention provides a magnesium alloy anticorrosive ceramic slurry, in which the mass ratio of ceramic aggregate to binder is 1:0.65~0.85. This includes 1:0.7~0.8, such as 1:0.75, 1:0.8, etc. In the process of technical development of the present invention, the binders initially selected are aluminum dihydrogen phosphate, sodium silicate, and potassium silicate. However, since aluminum dihydrogen phosphate is an acidic substance, when it is coated on the surface of the magnesium alloy substrate used in the present invention, the magnesium alloy is severely corroded and a large number of bubbles emerge. Potassium silicate is an alkaline binder, but the pH value is too high, reaching about 11, which will also cause bubbles to form in the magnesium alloy substrate. Therefore, sodium silicate is selected as the binder. The ratio of inorganic ceramic to binder is preliminarily determined to be 1:0.4, 1:0.8, and 1:1.2. After curing, it was found that too much binder content made it difficult for gas to be discharged during the curing process, resulting in bulging on the coating surface; too little binder will cause cracks on the coating surface, and the bonding between the coating and the substrate will be poor, resulting in partial falling of the coating; when the ceramic aggregate: binder = 1:0.8, there are no obvious defects on the coating surface, no bulging, better bonding with the substrate, and greater bonding strength.

Preferably, the present invention provides a magnesium alloy anticorrosive ceramic slurry, wherein the binder is composed of an organic binder and an inorganic binder, wherein the inorganic binder accounts for 80% to 95% of the total mass of the binder, and the balance is an organic binder, wherein the organic binder is γ-glycidyloxypropyltrimethoxysilane (GPTMS), and the inorganic binder is at least one of sodium silicate, potassium silicate, and aluminum dihydrogen phosphate, preferably sodium silicate. Of course, other inorganic binders can also be used in the present invention.

As a further preference, the present invention provides a magnesium alloy anti-corrosion ceramic slurry, wherein the binder consists of an organic binder and an inorganic binder, wherein the inorganic binder accounts for 84% to 86% of the total mass of the binder, and the remainder is the organic binder.

As a further preference, in the magnesium alloy anti-corrosion ceramic slurry of the present invention, the additive is added in an amount of 6-8% of the mass of the ceramic aggregate, such as 6%, 6.5%, 7%, 7.5%, 8% and the like.

The application of a magnesium alloy anticorrosive ceramic slurry of the present invention comprises the following steps:

Step 1: According to the mass percentage, Al ₂ O ₃ 29-33%, MgO 29-31%, SiO ₂ 29-31%, CeO ₂ 5-8%; mix the raw materials, stir and mix them evenly, and grind them into ceramic aggregates with uniform particles;

Step 2: Prepare a binder in a mass ratio of ceramic aggregate: binder = 1:0.5~1:1, wherein the binder is composed of an inorganic binder and an organic binder, wherein the mass percentage of the inorganic binder in the binder is 75%~95%, and the balance is an organic binder GPTMS, and the prepared organic binder and inorganic binder are uniformly stirred to obtain a mixed binder; the inorganic binder is selected from at least one of sodium silicate, potassium silicate, and aluminum dihydrogen phosphate;

Step 3: adding the mixed binder obtained in step 2 to the ceramic aggregate powder obtained in step 1, and adding deionized water to fully stir to obtain a uniform slurry;

Step 4: Add 6-8%, preferably Na ₂ SiF ₆ (compared to the mass of the slurry) to the slurry obtained in step 3, stir thoroughly for 10-20 minutes to obtain the final magnesium alloy ceramic slurry, evenly coat it on the magnesium alloy metal substrate, and cure at room temperature for 18-32 hours;

Step 5: Place the room temperature cured sample in a drying oven at 50-70°C for 1-3 hours, and then dry it at 100-120°C for 40-90 minutes to obtain a dense organic-inorganic composite coating.

The invention discloses an application of magnesium alloy anticorrosive ceramic slurry. The particle size of each raw material used in preparing the slurry is 100-120 microns. The particle size of the ceramic particles after grinding is 30-60 microns.

The invention provides an application of magnesium alloy anticorrosive ceramic slurry. In step 2, the prepared inorganic binder and organic binder are stirred with a magnetic stirrer at 40° C. to 60° C. for at least 10 minutes, preferably 10 to 20 minutes, to obtain a uniformly mixed binder.

In the present invention, the metal matrix comprises a magnesium alloy. Preferably, the magnesium alloy comprises the following components by mass percentage: Gd 8.0-9.6%, Y 1.8-3.2%, Zr 0.65-0.75%, and the balance is Mg.

In the application of the magnesium alloy anticorrosive ceramic slurry of the present invention, in step 3, the amount of deionized water used is about 15-25% of the total mass of the mixed binder + ceramic powder.

The coating of the present invention is cured at low temperature and a proper amount of sodium fluorosilicate (Na ₂ SiF ₆ ) is added. When Na ₂ SiF ₆ is added to water glass, it can neutralize the sodium hydroxide in the water glass solution to precipitate silicon dioxide gel and harden, so that the coating has good cohesive strength.

The organic matter used in the present invention is γ-glycidyloxypropyltrimethoxysilane (GPTMS), which can undergo dehydration condensation to form a high molecular polymer in the alkaline environment formed by a sodium silicate solution, and at the same time promote the sodium silicate to form a more stable Si-O-Si three-dimensional network structure.

Sodium silicate undergoes the following two steps of hydrolysis and condensation to form a Si-O-Si network structure:

Na ₂ O·nSiO ₂ + (2n+1)H ₂ O → 2NaOH + nSi(OH) ₄ (hydrolysis) (1)

nSi(OH) ₄ → [—Si—O—] _n (condensation) (2)

The chemical formula of GPTMS is CH ₂ CHCH ₂ O(CH ₂ ) ₂ Si(OCH ₃ ) ₃ . In the alkaline environment formed by sodium silicate, -OCH ₃ is first hydrolyzed to form -OH, and then -OH further undergoes condensation reaction to form Si-O-Si bond. In addition, the -OH generated by the hydrolysis of an appropriate amount of GPTMS can undergo condensation reaction simultaneously with Si(OH) ₄ formed by the hydrolysis of sodium silicate, forming a Si-O-Si network structure that is more stable and has a higher degree of polymerization than pure sodium silicate binder.

In the present invention, sodium fluorosilicate acts as a curing agent, and has a significant promoting effect on the curing of sodium silicate water glass. When too much sodium fluorosilicate is added to the slurry, the coating cures too fast, and solidification begins to occur in a short time, making the slurry thick and the fluidity deteriorating. When applied on the substrate surface, the coating is uneven and has a large thickness, and obvious cracks are prone to appear after being fully cured. When the sodium fluorosilicate content is low, the curing degree of the coating is not ideal. The present invention selects 6-8% of sodium fluorosilicate as an additive, so that the coating can be preferably applied on the substrate surface within a certain period of time, and the obtained coating is flat and has a controllable thickness, and can achieve a better curing effect at the same time.

The present invention regulates the corrosion potential E _corr of the coating to -1.25--1.10 V and the corrosion current density I _corr to 1.75×10 ^-9 -4.9×10 ^-10 A/cm ² under the synergistic effect of ceramic aggregates containing a large amount of magnesium oxide, binders and additives, thereby significantly improving the corrosion resistance of the product.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a drying process diagram used in Example 1;

FIG2 is an infrared spectrum of the sample obtained after room temperature curing and drying in Example 1;

FIG3 is an electron microscope image of the inorganic composite coating obtained in Example 2;

FIG4 is an electron microscope image of the organic-inorganic composite coating obtained in Example 5;

FIG5 is a photograph of the coating obtained in Exploration Example 1;

FIG6 is a photograph of the coating obtained in Exploration Example 2;

FIG. 7 is a photograph of the coating obtained in Exploration Example 3.

DETAILED DESCRIPTION

In the embodiments and comparative examples of the present invention, the metal matrix used is composed of the following components by mass percentage: Gd 8.8%, Y 2.5%, Zr 0.7%; the balance is Mg and unavoidable impurities.

Exploration Example 1

Step 1: Weigh the raw materials according to the determined inorganic ceramic component ratio: Al ₂ O ₃ 32wt.%, MgO 30wt.%, SiO ₂ 30wt.%, CeO ₂ 8wt.%, stir and mix them thoroughly, and grind them into ceramic powder with uniform particles; the particle size of the oxide used is 100-120 microns; the particle size of the ceramic particles after grinding is 30-60 microns.

Step 2: Prepare a binder in a mass ratio of ceramic aggregate to binder = 1:0.4, wherein the binder is sodium silicate;

Step 3: Add the mixed binder obtained in step 2 to the ceramic powder, and add deionized water and stir thoroughly to obtain a uniform slurry; the mass of the deionized water is 20% of the total mass of (binder + ceramic powder);

Step 4: Add 8% Na ₂ SiF ₆ (relative to the mass of the slurry) to the slurry obtained in step 3, stir thoroughly for 10 minutes to obtain the final inorganic composite coating slurry, evenly coat it on the metal substrate, and cure it at room temperature for 24 hours;

Step 5: Place the room temperature cured sample in a drying oven at 60°C for 2 hours, and then dry it at 120°C for 60 minutes to obtain a coating. The surface quality of the coating is shown in Figure 5, from which it can be seen that microcracks appear on the surface of the obtained coating. Electrochemical testing found that the corrosive medium can easily enter the surface of the substrate through defects such as cracks, causing corrosion of the substrate, and failing to achieve a more ideal protective effect. The coating impedance R _f is 7.12×10 ⁵ Ω, the charge transfer impedance R _ct is 3.50×10 ⁵ Ω, the corrosion potential E _corr is -1.43V, and the corrosion current density I _corr is 1.51×10 ^-7 A/cm ² .

Exploration Example 2

The other conditions are the same as those in Exploration Example 1, except that:

Step 2: Prepare the binder in the mass ratio of ceramic aggregate: binder = 1:0.8; the surface quality of the coating is shown in Figure 6. It can be seen from Figure 6 that the performance of the obtained coating is that there are no obvious defects on the coating surface, no bulges and microcracks, and the coating is relatively dense. The impedance test results show that a capacitive arc with a large radius appears, the coating impedance R _f is 9.54×10 ⁵ Ω, the charge transfer impedance R _ct is 1.95×10 ⁶ Ω, the corrosion potential E _corr is -1.37V, and the corrosion current density I _corr is 1.45×10 ^-8 A/cm ^2. It shows that the coating can provide better protection.

Exploration Example 3

The other conditions are the same as those in Exploration Example 1, except that:

Step 2: Prepare the binder in a mass ratio of ceramic aggregate: binder = 1:1.2; the surface quality of the obtained coating is shown in FIG7 , which shows obvious bulging, poor bonding with the substrate, and easy to fall off.

Example 1

Other conditions were the same as those in Exploration Example 2, except that: 2% by weight (relative to the weight of the slurry) of curing agent Na ₂ SiF ₆ was added to the slurry, and the final coating slurry was obtained after sufficient stirring for 10 minutes, which was evenly coated on the metal substrate and cured at room temperature for 24 hours;

The room temperature cured sample was placed in a drying oven at 60°C for 2 hours and then dried at 110°C for 60 minutes to obtain an inorganic composite coating. The degree of curing of the obtained coating was not ideal, and its performance was far worse than that of Exploration Example 2.

Example 2

Other conditions were the same as those in Exploration Example 2, except that: 6% by weight (relative to the weight of the slurry) of curing agent Na ₂ SiF ₆ was added to the slurry, and the final coating slurry was obtained after sufficient stirring for 10 minutes, which was evenly coated on the metal substrate and cured at room temperature for 24 hours;

Step 5: Place the room temperature cured sample in a drying oven at 60°C for 1 hour, and then dry it at 110°C for 60 minutes to obtain an inorganic composite coating (see Figure 3). Under this composition, the coating can be well coated on the substrate surface within a certain period of time. The obtained coating is flat and has a controllable thickness. At the same time, it can achieve a better curing effect. The surface is flatter than that of Exploration Example 2, and the curing is more uniform.

It can be seen from Figure 3 that a film layer with a thickness of about 5µm is formed on the surface of the coating, which is mainly formed by the hydrolysis and condensation of sodium silicate. A large number of cracks are generated inside the obtained coating, and a large number of cracks extend from the surface film layer to the metal/coating interface, indicating that the network structure of Si-O-Si bonds formed by the single sodium silicate binder that has not been modified by silane is not strong enough. The corrosive medium can pass through these defects to reach the surface of the metal substrate, causing corrosion of the metal.

Example 3

Other conditions were the same as those in Exploration Example 2, except that: 10% by weight (relative to the weight of the slurry) of curing agent Na ₂ SiF ₆ was added to the slurry, and the final coating slurry was obtained after sufficient stirring for 10 minutes, which was evenly coated on the metal substrate and cured at room temperature for 24 hours;

The performance of the obtained coating is that the coating cures too quickly and begins to cure in a short time, making the slurry thick and the fluidity poor. When applied on the surface of the substrate, the coating is uneven and has a large thickness. After complete curing, obvious cracks are likely to appear.

Example 4

The other conditions are the same as those in Example 2, except that: the mass percentage of the inorganic binder in the binder is 80%, and the balance is the organic binder GPTMS; local microcracks appear on the surface of the obtained coating, but no microcracks appear in the middle layer, so the further electrochemical test results are compared with the sample without adding GPTMS (i.e., the product obtained in Comparative Example 1), the impedance value is increased, the corrosion current density is also lower, and the corrosive medium does not directly reach the surface of the substrate. The specific properties of the obtained coating are: coating impedance _Rf is 1.16× ^104Ω , charge transfer impedance _Rct is 3.35× ^107Ω , corrosion potential _Ecorr is -1.20V, and corrosion current density _Icorr is 1.71× ^10-9A / ^cm2 .

Example 5

The other conditions are the same as those in Example 2, except that the mass percentage of the inorganic binder in the binder is 85%, and the balance is the organic binder GPTMS. The surface and interior of the obtained coating have no obvious defects, the electrochemical test results are optimal, and the corrosion current density is reduced by one order of magnitude compared with Example 4, indicating that the coating can provide a better protective effect. The electron microscope characterization diagram of the coating is shown in Figure 4. It can be seen from Figure 4 that when 15% GPTMS is added to the sodium silicate binder for modification, there is basically no crack inside the coating, only a small number of small closed pores, and the surface film layer still exists, which can prevent the entry of corrosive media to a certain extent. The specific properties of the obtained coating are: coating impedance R _f is 2.67×10 ⁴ Ω, charge transfer impedance R _ct is 6.4×10 ⁷ Ω, corrosion potential E _corr is -1.10V, and corrosion current density I _corr is 4.9×10 ^-10 A/cm ² .

Example 6

The other conditions are the same as those in Example 2, except that: the mass percentage of the inorganic binder in the binder is 90%, and the balance is the organic binder GPTMS; the performance of the obtained coating is that there is no obvious defect on the coating surface, and further microscopic morphology analysis of the cross section shows that cracks appear in the middle layer of the coating, indicating that the crosslinking strength of the coating is worse than that of Example 5, and the ideal crosslinking effect is not achieved. Specifically, the impedance and corrosion current density are worse than those of Example 5. The specific properties of the obtained coating are: the coating impedance _Rf is 9.01×10 ⁵ Ω, the charge transfer impedance _Rct is 1.5×10 ⁷ Ω, the corrosion potential _Ecorr is -1.21V, and the corrosion current density _Icorr is 9.18×10 ^-10 A/cm ^2. Although the coating resistance under this composition is greater than that of Example 5, it can be further seen from the indicator _Rp (polarization resistance) = _Rf + _Rct for evaluating corrosion performance that its corrosion resistance is worse than that of Example 5.

It can be seen from Examples 2, 4, 5 and 6 that the addition of an appropriate amount of GPTMS can promote the increase in the degree of polymerization of silicate aggregates in water glass, form a Si-O-Si network structure with higher cohesive strength, and reduce the generation of defects such as cracks.

Claims (5)

1. The magnesium alloy anticorrosive ceramic slurry is characterized in that: the magnesium alloy ceramic slurry comprises ceramic aggregate, a binder, an additive and water, wherein the ceramic aggregate comprises the following components in percentage by mass: 5-8% of Al ₂O₃ 29~33%、MgO 29~31%、SiO₂ 29~31%、CeO₂; the additive comprises Na ₂SiF₆; in the magnesium alloy ceramic slurry, the mass percentage of water is 15-25%; the ceramic aggregate comprises the following components in percentage by mass: binder = 1: 0.5-1; the adhesive consists of an organic adhesive and an inorganic adhesive, wherein the inorganic adhesive accounts for 80-95% of the total weight of the adhesive, the balance is the organic adhesive, the organic adhesive is gamma-glycidyl ether oxypropyl trimethoxy silane, and the inorganic adhesive is sodium silicate; the addition amount of the additive is 6-8% of the total mass of the ceramic aggregate, the binder and the water.

2. The magnesium alloy corrosion-resistant ceramic slurry according to claim 1, wherein: the ceramic aggregate comprises the following components in percentage by mass: binder = 1:0.65 to 0.85.

3. The magnesium alloy corrosion-resistant ceramic slurry according to claim 1, wherein: the inorganic binder accounts for 84% -86% of the total mass of the binder.

4. An application of magnesium alloy anticorrosive ceramic slurry is characterized in that: comprises the following steps of;

Step 1

According to the mass percentage, 5-8% of Al ₂O₃ 29~33%、MgO 29~31%、SiO₂ 29~31%、CeO₂; preparing raw materials, uniformly stirring and mixing, and grinding into ceramic aggregate with uniform particles;

Step 2

According to the mass ratio, the ceramic aggregate: binder = 1: preparing an adhesive according to a proportion of 0.5-1, wherein the adhesive consists of an inorganic adhesive and an organic adhesive, the mass percentage of the inorganic adhesive in the adhesive is 80% -95%, and the balance is the organic adhesive, and uniformly stirring the prepared organic adhesive and the inorganic adhesive to obtain a mixed adhesive; the inorganic binder is sodium silicate; the organic binder is gamma-glycidyl ether oxypropyl trimethoxy silane;

Step 3

Adding the mixed binder obtained in the step 2 into the ceramic aggregate powder obtained in the step 1, and adding deionized water to fully stir to obtain uniform slurry;

Step 4

Adding Na ₂SiF₆ accounting for 6-8% of the mass of the slurry into the slurry obtained in the step 3, stirring for 10-20 min to obtain magnesium alloy ceramic slurry, uniformly coating the magnesium alloy ceramic slurry on a magnesium alloy metal substrate, and curing the magnesium alloy ceramic slurry at room temperature for 18-32 h;

Step 5

And placing the sample cured at room temperature in a drying oven, drying at 50-70 ℃ for 1-3 hours, and drying at 100-150 ℃ for 40-90 minutes to obtain the magnesium alloy anti-corrosion coating.

5. The use of a magnesium alloy corrosion resistant ceramic slurry according to claim 4, wherein: the grain size of each raw material is 100-120 microns; the particle size of the ceramic particles after grinding is 30-60 microns.