阅读说明：本技术 一种镍包石墨增强耐磨减摩耐腐蚀陶瓷涂层材料、涂层及其制备方法与应用 (Nickel-coated graphite enhanced wear-resistant antifriction corrosion-resistant ceramic coating material, coating, and preparation method and application thereof ) 是由 刘雅玄 吴王平 王永光 卞达 张屹 赵永武 于 2021-07-05 设计创作，主要内容包括：一种镍包石墨增强耐磨减摩耐腐蚀陶瓷涂层材料、涂层及其制备方法与应用,属于金属涂层技术领域。镍包石墨增强耐磨减摩耐腐蚀陶瓷涂层材料包括以下组分：镍包石墨2％～4％、微米氧化铝45％～60％、微米氧化锆2％～8％、钼酸钠4％～6％、固化剂1％～3％、粘结剂40％～45％。本发明还提供了所述陶瓷涂层材料制备而成的粘结陶瓷涂层及其制备方法。本发明制备的镍包石墨增强耐磨减摩耐腐蚀陶瓷涂层,采用溶胶凝胶法制备,制备工艺简单,并且具有良好的耐磨减摩耐腐蚀性能,可以应用于各种苛刻的腐蚀环境以及各种承受冲击和磨损零件表面,具有相当广阔的应用价值。(A nickel-coated graphite enhanced wear-resistant antifriction corrosion-resistant ceramic coating material, a coating, a preparation method and an application thereof belong to the technical field of metal coatings. The nickel-coated graphite reinforced wear-resistant antifriction corrosion-resistant ceramic coating material comprises the following components: 2-4% of nickel-coated graphite, 45-60% of micron alumina, 2-8% of micron zirconia, 4-6% of sodium molybdate, 1-3% of a curing agent and 40-45% of a binder. The invention also provides a bonding ceramic coating prepared from the ceramic coating material and a preparation method thereof. The nickel-coated graphite enhanced wear-resistant, antifriction and corrosion-resistant ceramic coating prepared by the invention is prepared by a sol-gel method, has a simple preparation process and good wear-resistant, antifriction and corrosion-resistant properties, can be applied to various harsh corrosion environments and various surfaces of parts which bear impact and wear, and has quite wide application value.)

1. The nickel-coated graphite enhanced wear-resistant antifriction corrosion-resistant ceramic coating material is characterized by comprising the following raw materials in parts by mass: 2-4 parts of nickel-coated graphite, 45-60 parts of micron alumina, 2-8 parts of micron zirconia, 4-6 parts of sodium molybdate, 1-3 parts of a curing agent and 40-45 parts of a binder.

2. The wear-resistant, friction-reducing and corrosion-resistant ceramic coating material enhanced by nickel-coated graphite according to claim 1, wherein the nickel-coated graphite is one of three series of nickel-coated graphite powders DS237E, DS238E and DS239E, and the corresponding components are 95Ni/5C, 75Ni/25C and 60Ni/40C respectively.

3. The wear-resistant, friction-reducing and corrosion-resistant ceramic coating material reinforced by nickel-coated graphite according to claim 1, wherein the particle size of the nickel-coated graphite is 10-15 μm, the particle size of the micron aluminum oxide is 3-4 μm, and the particle size of the micron zirconium oxide is 1-2 μm.

4. The nickel-coated graphite enhanced wear-resistant, friction-reducing and corrosion-resistant ceramic coating material as claimed in claim 1, wherein the curing agent is a curing agent containing a metal oxide, the metal oxide is at least one of magnesium oxide and zinc oxide, the binder is aluminum dihydrogen phosphate, the nickel-coated graphite is a functional additive, micron-sized aluminum oxide and zirconium oxide are ceramic aggregates, and sodium molybdate is a corrosion inhibitor.

5. The preparation method of the coating of the nickel-coated graphite reinforced wear-resistant, friction-reducing and corrosion-resistant ceramic coating material based on claim 1 is characterized by comprising the following steps:

weighing nickel-coated graphite, micron alumina, micron zirconia, sodium molybdate, a curing agent and a binder according to the mass part ratio, mixing the nickel-coated graphite, the micron alumina, the micron zirconia, the sodium molybdate and the curing agent, and then carrying out ball milling for 6-8 hours;

secondly, adding a binder into the ball-milled powder, and fully and uniformly mixing the powder through magnetic stirring, wherein the stirring time is not less than 12 hours;

and step three, coating the obtained sol-gel on a pretreated metal substrate, and performing step curing treatment to obtain the nickel-coated graphite enhanced wear-resistant, antifriction and corrosion-resistant ceramic coating.

6. The preparation method of the nickel-coated graphite enhanced wear-resistant, friction-reducing and corrosion-resistant ceramic coating according to claim 5, wherein the pretreatment of the substrate in the third step comprises roughening treatment and cleaning pretreatment of the surface of the metal substrate, and the specific process is as follows: firstly, removing rust spots and a surface oxidation layer on the surface of metal by using coarse sand paper; then, primarily scouring surface abrasive dust by running water; then ultrasonically cleaning the substrate by an ultrasonic cleaning machine, wherein the cleaning solution is alcohol, and the cleaning time is 30 minutes; and finally drying the surface of the metal substrate by using a blower.

7. The method for preparing the nickel-coated graphite enhanced wear-resistant, friction-reducing and corrosion-resistant ceramic coating according to claim 5, wherein the gradient curing process in the third step is as follows: curing at room temperature for 12 hours, then curing at 50 ℃, 100 ℃, 200 ℃ and 300 ℃ for 1 hour respectively, and cooling along with a furnace to obtain the nickel-coated graphite enhanced wear-resistant, antifriction and corrosion-resistant ceramic coating.

8. The nickel-coated graphite enhanced wear-resistant, friction-reducing and corrosion-resistant ceramic coating prepared by the method of any one of claims 5 to 7.

9. The nickel-coated graphite enhanced wear-resistant, friction-reducing and corrosion-resistant ceramic coating according to claim 8, wherein the thickness of the coating is 200 μm.

10. The use of the nickel coated graphite wear, friction, corrosion resistant enhanced ceramic coating of claim 8 for repairing and protecting the surfaces of components.

The technical field is as follows:

the invention relates to the technical field of metal coatings, in particular to a nickel-coated graphite reinforced wear-resistant antifriction corrosion-resistant ceramic coating material, a nickel-coated graphite reinforced wear-resistant antifriction corrosion-resistant ceramic coating, a preparation method and application of the nickel-coated graphite reinforced wear-resistant antifriction corrosion-resistant ceramic coating material.

Background art:

metal fretting corrosion is one of the most noticeable problems, and the direct loss of alloy material by fretting corrosion is enormous. Furthermore, with the progress of industrialization, the problem of abrasion and corrosion becomes more and more serious.

The ceramic coating can reduce the friction coefficient and reduce the wear rate, thereby achieving the purpose of protecting metal parts. Many methods, such as electrophoretic deposition, plasma spray, and sol-gel methods, which are effective for preparing ceramic coatings, have been developed to improve the tribological corrosion properties of metallic materials. Among these methods, the sol-gel method has attracted much attention because of its advantages of economy, simple operation, small residual stress, and low curing temperature, which can reduce the possibility of oxidation of the metal substrate. However, due to the different thermal expansion coefficients of the ceramic coating and the substrate, the low compactness of the microstructure of the coating, and the like, the bonding property and the frictional corrosion property of the ceramic coating and the substrate obtained by the method are still to be improved.

Nickel-coated graphite powder is composite powder which takes graphite particles as cores and is coated with metallic nickel. The powder has good lubrication and corrosion resistance, is easy to be widely used for manufacturing high-temperature self-lubricating bearing materials, low-friction materials, porous nickel strips and the like, and has become one of hot spots of research in various countries.

The Chinese patent application with the publication number of CN111910144A discloses a nickel-coated graphite sealing coating on the surface of a cast iron workpiece and a preparation method thereof, wherein a self-lubricating coating containing nickel-coated graphite is prepared by using a thermal spraying technology, so that the bonding strength between the coating and a substrate is improved. Chinese patent application with publication number CN112144056A discloses a nickel-based composite coating applied to austenitic stainless steel and a preparation method thereof, firstly raw materials are evenly coated on the surface of an austenitic stainless steel matrix, raw material powder is a mixed cladding material and consists of nickel-based powder (Ni60A), pure titanium powder (Ti), nickel-coated graphite powder (C @ Ni) and nickel-coated molybdenum disulfide powder ([email protected] Ni), then laser cladding is carried out on the powder surface by adopting a preset powder method, in the laser cladding process, the powder is subjected to in-situ reaction, the reinforcement formed by the in-situ reaction and the matrix are thermodynamically stable, the ceramic hard phase formed by the in-situ reaction of 0Cr18Ni9 has pure interface with the matrix phase, and high interface bonding strength, and effectively solves the problems of uncontrollable reinforcement size and interface reaction and the like in the process of preparing the composite coating by an additional particle method and the problems of poor wear resistance and low hardness of 0Cr18Ni9 austenitic stainless steel in the prior art. It can be seen that the addition of nickel coated graphite can improve the performance of the coating. However, the working environment of metal under actual working conditions is complex, the synergistic effect of friction and corrosion is unavoidable, the two often occur simultaneously, affect each other and interact with each other, the corrosion accelerates the wear loss of the coating, the wear accelerates the corrosion speed of the coating, but at present, research on the comprehensive effect and the influence mechanism of the nickel-coated graphite on the friction corrosion of the bonded ceramic coating is still lacked.

The invention content is as follows:

the technical problem to be solved is as follows: in order to overcome the defects of wear resistance, friction reduction and corrosion resistance of the existing ceramic coating, the invention provides a nickel-coated graphite enhanced wear-resistant, friction-reduction and corrosion-resistance ceramic coating material, a coating, a preparation method and application thereof.

The technical scheme is as follows: a nickel-coated graphite enhanced wear-resistant antifriction corrosion-resistant ceramic coating material comprises the following raw materials in parts by weight: 2-4 parts of nickel-coated graphite, 45-60 parts of micron alumina, 2-8 parts of micron zirconia, 4-6 parts of sodium molybdate, 1-3 parts of a curing agent and 40-45 parts of a binder.

Preferably, the nickel-coated graphite is one of three series of nickel-coated graphite powders DS237E, DS238E and DS239E, and the corresponding components are 95Ni/5C, 75Ni/25C and 60Ni/40C respectively.

Preferably, the particle size of the nickel-coated graphite is 10-15 mu m, the particle size of the micron aluminum oxide is 3-4 mu m, and the particle size of the micron zirconium oxide is 1-2 mu m.

Preferably, the curing agent is a curing agent containing metal oxide, the metal oxide is at least one of magnesium oxide and zinc oxide, the binder is aluminum dihydrogen phosphate, the nickel-coated graphite is a functional additive, the micron-grade aluminum oxide and zirconium oxide are ceramic aggregates, and the sodium molybdate is a corrosion inhibitor.

The preparation method of the coating based on the nickel-coated graphite reinforced wear-resistant antifriction corrosion-resistant ceramic coating material comprises the following steps:

weighing nickel-coated graphite, micron alumina, micron zirconia, sodium molybdate, a curing agent and a binder according to the mass part ratio, mixing the nickel-coated graphite, the micron alumina, the micron zirconia, the sodium molybdate and the curing agent, and then carrying out ball milling for 6-8 hours;

secondly, adding a binder into the ball-milled powder, and fully and uniformly mixing the powder through magnetic stirring, wherein the stirring time is not less than 12 hours;

and step three, coating the obtained sol-gel on a pretreated metal substrate, and performing step curing treatment to obtain the nickel-coated graphite enhanced wear-resistant, antifriction and corrosion-resistant ceramic coating.

Preferably, the pretreatment of the substrate in the third step comprises roughening and cleaning pretreatment of the surface of the metal substrate, and the specific process is as follows: firstly, removing rust spots and a surface oxidation layer on the surface of metal by using coarse sand paper; then, primarily scouring surface abrasive dust by running water; then ultrasonically cleaning the substrate by an ultrasonic cleaning machine, wherein the cleaning solution is alcohol, and the cleaning time is 30 minutes; and finally drying the surface of the metal substrate by using a blower.

Preferably, the gradient curing process in the third step is as follows: curing at room temperature for 12 hours, then curing at 50 ℃, 100 ℃, 200 ℃ and 300 ℃ for 1 hour respectively, and cooling along with a furnace to obtain the nickel-coated graphite enhanced wear-resistant, antifriction and corrosion-resistant ceramic coating.

The nickel-coated graphite enhanced wear-resistant antifriction corrosion-resistant ceramic coating prepared by the method.

Preferably, the thickness of the coating is 200 [ mu ] m.

The nickel-coated graphite enhanced wear-resistant antifriction corrosion-resistant ceramic coating is applied to repairing and protecting the surfaces of parts.

Has the advantages that: the invention provides a nickel-coated graphite enhanced wear-resistant antifriction corrosion-resistant ceramic coating material, a coating, a preparation method and application thereof, and the nickel-coated graphite is introduced to a phosphate bonding ceramic coating, so that the wear-resistant antifriction corrosion-resistant performance of the coating is improved.

(2) The nickel-coated graphite adopted by the invention has good lubricity, and the nickel powder contained in the powder can be used as a toughening phase of the coating, so that the toughness of the coating is improved, and the wear resistance of the coating is further improved. The graphite contained in the powder can be used as a self-lubricating phase of the coating, so that the frictional wear between the coating and a friction pair is effectively reduced, and the service cycle of the metal material is prolonged.

(3) The sodium molybdate adopted by the invention is used as a high-efficiency environment-friendly corrosion inhibitor with low toxicity, no harm and good stability, and can form a passivation film with good corrosion resistance on the surface of steel, thereby effectively delaying the diffusion speed (O) of a corrosion medium₂、H₂O and Cl^-) And the effect of protecting the metal matrix is achieved by matching with nickel-coated graphite.

(4) The preparation method provided by the invention has the advantages of simple process and low cost, widens the application field of the coating in severe environment, and has a very wide market prospect.

Description of the drawings:

FIG. 1 is a microscopic morphology of different series of nickel-coated graphite enhanced phosphate ceramic coatings, wherein (a) is a microscopic morphology of a DS237E nickel-coated graphite enhanced phosphate ceramic coating, (b) is a microscopic morphology of a DS238E nickel-coated graphite enhanced phosphate ceramic coating, and (c) is a microscopic morphology of a DS239E nickel-coated graphite enhanced phosphate ceramic coating;

FIG. 2 is a graph of the friction coefficients of different series (DS 237E, DS238E and DS 239E) of nickel-coated graphite enhanced phosphate ceramic coatings;

FIG. 3 is a graph of wear rates of different series (DS 237E, DS238E, and DS 239E) of nickel-coated graphite enhanced phosphate ceramic coatings;

FIG. 4 is a graph of the wear-induced micro-topography of various series (DS 237E, DS238E, and DS 239E) of nickel-coated graphite enhanced phosphate ceramic coatings, in which (a) is a graph of the wear-induced micro-topography of the coating prepared in comparative example 1; (b) the wear-induced micro-topography of the coating prepared in comparative example 2, (c) the wear-induced micro-topography of the DS237E nickel-coated graphite reinforced phosphate ceramic coating in example 1, (d) the wear-induced micro-topography of the DS238E nickel-coated graphite reinforced phosphate ceramic coating in example 2, and (e) the wear-induced micro-topography of the DS239E nickel-coated graphite reinforced phosphate ceramic coating in example 3.

FIG. 5 shows electrochemical impedance spectra of different series (DS 237E, DS238E and DS 239E) of nickel-coated graphite enhanced phosphate ceramic coatings.

The specific implementation scheme is as follows:

for further explanation of the present invention, the following detailed descriptions of the coating material, the coating layer, the preparation method and the application of the coating material, the coating layer, and the preparation method and the application of the coating material are provided with the nickel-coated graphite for enhancing wear resistance, friction reduction and corrosion resistance, but the invention is not to be construed as limiting the protection scope of the present invention.

And (3) wear-resistant and antifriction test: the tribology test research is carried out on the ceramic coating by adopting an MFT-5000 series universal friction wear testing machine, and the test conditions are as follows: the load is 20N, the test time is 30 minutes, the speed is 20mm/s, and the pair of friction balls are silicon nitride balls with the diameter phi of 9 mm. The main reference indexes are the friction coefficient and the wear rate of the ceramic coating, each sample is repeated for five times to ensure the accuracy of the experiment, and the average value of the results is taken.

And (3) electrochemical performance testing: electrochemical tests were performed using an electrochemical workstation model CHI 660-E. Platinum electrodes and Ag/AgCl electrodes (3M) in saturated KCl solution were used as comparative and reference electrodes, respectively. Before the test, the ceramic coating surface is taken as a working surface, and the rest surfaces are packaged and insulated by silicon rubber. The area of the sample immersed in a 3.5wt% sodium chloride solution during the test was about 1cm². The Electrochemical Impedance (EIS) sine alternating current disturbance wavelength and frequency ranges are respectively 10mV and 10mV^-2~10⁵Hz. To ensure the reliability of the results, three tests were carried out for each testDuplicate measurements.

Example 1

The nickel-coated graphite in this example was DS237E, 95 Ni/5C. The curing agent is zinc oxide. The binder is aluminum dihydrogen phosphate.

(1) Weighing functional additives of nickel-coated graphite, ceramic aggregate (micron alumina and micron zirconia), corrosion inhibitor sodium molybdate, curing agent and binder. The mass portion ratio is as follows: 2 parts of nickel-coated graphite, 50 parts of micron alumina, 2 parts of micron zirconia, 5 parts of sodium molybdate, 1 part of zinc oxide and 40 parts of aluminum dihydrogen phosphate.

(2) And mixing the functional additive, the ceramic aggregate, the corrosion inhibitor and the curing agent by using a ball mill. The rotating speed is 250 r.min during ball milling^-1The total ball milling time is 8 hours, and the proportion of balls to materials is 1.2: 1, agate pellets are adopted as the pellets.

(3) And adding aluminum dihydrogen phosphate binder into the ball-milled powder, and stirring for 12 hours by magnetic stirring to fully and uniformly mix the powder.

(4) The surface of the metal substrate is subjected to roughening treatment and cleaning pretreatment. Firstly, removing rust spots and a surface oxidation layer on the surface of the steel sheet by using coarse sand paper, and then preliminarily flushing surface abrasive dust by flowing water; then ultrasonically cleaning the substrate by an ultrasonic cleaning machine, wherein the cleaning solution is alcohol, and the cleaning time is 30 minutes; and finally drying the surface of the metal substrate by using a blower.

(5) And coating the uniformly mixed slurry on the surface of the treated metal substrate by a blade coating method.

(6) Curing the coating, wherein the curing process comprises the following steps: curing at room temperature for 12 hours, and then curing at 50 ℃, 100 ℃, 200 ℃ and 300 ℃ for 1 hour respectively to obtain the ceramic coating with the nickel-coated graphite content of 2 percent. The coating micro-topography is shown in FIG. 1 (a).

The obtained friction coefficient, wear rate, micro-topography after wear and electrochemical impedance spectrogram are shown in fig. 2, fig. 3, fig. 4 and fig. 5.

Example 2

The nickel-coated graphite in this example was DS238E, 75 Ni/25C. The curing agent is zinc oxide. The binder is aluminum dihydrogen phosphate.

(1) Weighing functional additives of nickel-coated graphite, ceramic aggregate (micron alumina and micron zirconia), corrosion inhibitor sodium molybdate, curing agent and binder. The mass portion ratio is as follows: 2 parts of nickel-coated graphite (DS238E, 75Ni/25C), 50 parts of micron alumina, 2 parts of micron zirconia, 5 parts of sodium molybdate, 1 part of zinc oxide and 40 parts of aluminum dihydrogen phosphate.

(2) And mixing the functional additive, the ceramic aggregate, the corrosion inhibitor and the curing agent by using a ball mill. The rotating speed is 250 r.min during ball milling^-1The total ball milling time is 8 hours, and the proportion of balls to materials is 1.2: 1, agate pellets are adopted as the pellets.

(3) And adding aluminum dihydrogen phosphate binder into the ball-milled powder, and stirring for 12 hours by magnetic stirring to fully and uniformly mix the powder.

(4) The surface of the metal substrate is subjected to roughening treatment and cleaning pretreatment. Firstly, removing rust spots and a surface oxidation layer on the surface of the steel sheet by using coarse sand paper, and then preliminarily flushing surface abrasive dust by flowing water; then ultrasonically cleaning the substrate by an ultrasonic cleaning machine, wherein the cleaning solution is alcohol, and the cleaning time is 30 minutes; and finally drying the surface of the metal substrate by using a blower.

(5) And coating the uniformly mixed slurry on the surface of the treated metal substrate by a blade coating method.

(6) Curing the coating, wherein the curing process comprises the following steps: curing at room temperature for 12 hours, and then curing at 50 ℃, 100 ℃, 200 ℃ and 300 ℃ for 1 hour respectively to obtain the ceramic coating with the nickel-coated graphite content of 2 percent. The coating micro-topography is shown in FIG. 1 (b).

The obtained friction coefficient, wear rate, micro-topography after wear and electrochemical impedance spectrogram are shown in fig. 2, fig. 3, fig. 4 and fig. 5.

Example 3

The nickel-coated graphite in this example is DS239E, 60 Ni/40C. The curing agent is zinc oxide. The binder is aluminum dihydrogen phosphate.

(1) Weighing functional additives of nickel-coated graphite, ceramic aggregate (micron alumina and micron alumina), corrosion inhibitor sodium molybdate, curing agent and binder. The mass portion ratio is as follows: 2 parts of nickel-coated graphite, 50 parts of micron alumina, 2 parts of micron zirconia, 5 parts of sodium molybdate, 1 part of zinc oxide and 40 parts of aluminum dihydrogen phosphate.

(2) And mixing the functional additive, the ceramic aggregate, the corrosion inhibitor and the curing agent by using a ball mill. The rotating speed is 250 r.min during ball milling^-1The total ball milling time is 8 hours, and the proportion of balls to materials is 1.2: 1, agate pellets are adopted as the pellets.

(3) And adding aluminum dihydrogen phosphate binder into the ball-milled powder, and stirring for 12 hours by magnetic stirring to fully and uniformly mix the powder.

(4) The surface of the metal substrate is subjected to roughening treatment and cleaning pretreatment. Firstly, removing rust spots and a surface oxidation layer on the surface of the steel sheet by using coarse sand paper, and then preliminarily flushing surface abrasive dust by flowing water; then ultrasonically cleaning the substrate by an ultrasonic cleaning machine, wherein the cleaning solution is alcohol, and the cleaning time is 30 minutes; and finally drying the surface of the metal substrate by using a blower.

(5) And coating the uniformly mixed slurry on the surface of the treated metal substrate by a blade coating method.

(6) Curing the coating, wherein the curing process comprises the following steps: curing at room temperature for 12 hours, and then curing at 50 ℃, 100 ℃, 200 ℃ and 300 ℃ for 1 hour respectively to obtain the ceramic coating with the nickel-coated graphite content of 2 wt.%. The coating micro-topography is shown in FIG. 1 (c).

The obtained friction coefficient, wear rate, micro-topography after wear and electrochemical impedance spectrogram are shown in fig. 2, fig. 3, fig. 4 and fig. 5.

Comparative example 1

Ceramic coatings were prepared according to the method of example 1 except that no nickel coated graphite was added and the alumina content was 52 wt.%, and the friction coefficient and wear rate were as shown in fig. 2 and 3 under the same conditions as in example 1.

Comparative example 2

The ceramic coating was prepared according to the method of example 1, except that nickel-coated graphite was replaced with nickel powder, and the friction coefficient and wear rate were as shown in fig. 2 and 3 under the same conditions as in example 1.

Comparative example 3

The metal substrate without ceramic coating was used as a blank control example, the metal substrate used was stainless steel, and the obtained electrochemical impedance spectrum was shown in fig. 5.

And (4) evaluating the friction behavior of the nickel-coated graphite reinforced ceramic coating through a friction and wear test. The friction coefficient, wear rate, wear scar topography after wear are shown in fig. 2, 3 and 4. As can be seen from the figure: with the addition of the nickel-coated graphite, the friction coefficient and the wear rate of the ceramic coating are reduced, mainly because the nickel powder in the nickel-coated graphite can play a role in repairing the surface of a grinding crack. And the graphite is equivalent to a lubricant, so that the self-lubricating property of the coating is improved. When the coating is loaded, graphite can be separated out from nickel-coated graphite and flows under the action of tangential force, and the rough-surface valley can be filled and leveled, so that the amplitude and frequency of stress-strain are reduced, and the wear resistance of the coating is improved. In addition, when the nickel-coated graphite corresponds to a composition of 75Ni/25C, the wear rate of the corresponding coating is lowest. The reason for this is that the graphite in the nickel-coated graphite in this ratio can be well embedded in the coating, thereby playing a role in reducing wear. And compared with the coating added with the nickel-coated graphite reinforcing phase, the wear rate of the coating is higher when the reinforcing phase is nickel powder. Therefore, compared with the ceramic coating without nickel-coated graphite and added with nickel powder, the nickel-coated graphite reinforced ceramic coating has better wear-resistant and antifriction characteristics, thereby protecting the matrix from being damaged and prolonging the service life of the metal matrix.

And evaluating the corrosion behavior of the nickel-coated graphite reinforced ceramic coating by an electrochemical test (electrochemical impedance method). The electrochemical impedance spectroscopy curve is shown in fig. 5. As can be seen from fig. 5: the modulus of impedance at the lowest frequency for example 1, example 2 and example 3 compared to stainless steel: (f _min =0.01 Hz), indicating that the nickel-coated graphite reinforced ceramic coating is effective against the penetration of the electrolyte. In addition, the impedance modulus at the lowest frequency of examples 2 and 3 decreases compared to example 1, indicating that the corrosion resistance of the coating improves as the nickel powder content in the nickel-coated graphite increases. Therefore, compared with the metal substrate which is not coated with the ceramic coating, the nickel-coated graphite reinforced ceramic coating has better corrosion resistance,thereby protecting the substrate from being damaged and prolonging the service life of the metal substrate.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.