Splicing method of composite coatings with different thicknesses, metal part and application

Abstract

The invention provides a splicing method of composite coatings with different thicknesses, a metal part and application. The splicing method comprises the following steps: designing the shape of a shelter; the shielding object is adopted to shield a thin layer design area of a metal base material, then a composite coating is deposited on the surface of the metal base material, the shielding object is removed after a certain thickness is deposited, deposition of the composite coating continues to be carried out, and after deposition is finished, composite coatings with different thicknesses are obtained on the surface of the metal base material. The splicing method provided by the invention can realize the adjustment of the friction coefficient and the diversified combination of the material performance, adapts to the change of the microstructure of the material, and improves the overall performance of the material; and meanwhile, the coating can better adapt to metal substrates with various complex shapes, and the covering effect and the protection performance of the coating are improved. Importantly, the splicing method can reduce the cost, improve the production efficiency, reduce the waste in the production process and meet the industrial requirements on the premise of meeting the performance requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of metal coating painting, and in particular relates to a splicing method of composite coatings of different thicknesses, a metal component and an application thereof. Background Art

[0002] Ships are an important means of transportation, and steel is the most commonly used material in ships. However, in the marine environment, steel is prone to electrochemical corrosion, which greatly reduces its service life. Corrosion is the main cause of material degradation and is a key issue that seriously affects the durability and reliability of structures and components.

[0003] Q235 steel material has excellent mechanical properties as well as good formability and weldability, making it widely used in the manufacture of marine environment components. However, due to the influence of chlorine-containing environment, steel will be severely degraded, resulting in pitting or stress corrosion cracking of the material. Therefore, surface treatment must be used to isolate the metal substrate from the corrosive environment to extend the service life of structures and components.

[0004] Among various surface treatment methods, thermal spraying offers a wide range of material options, with advantages such as fast deposition rates and a wide range of coating thicknesses. Therefore, thermal spraying is often used to prepare protective coatings to combat highly corrosive marine environments. Among them, nickel-based coatings have excellent wear resistance and corrosion resistance, and are therefore widely used to improve the performance of material surfaces. Ceramic coatings have enhanced properties, such as chemical and environmental resistance and high thermal stability, and have been widely used in various industries. Therefore, preparing a nickel-based ceramic composite coating is an effective means to increase the life of the material.

[0005] However, in some application scenarios, different parts have different requirements for coating performance. For example, some parts may require higher thermal insulation performance, while other parts may pay more attention to wear resistance or performance. By splicing coatings of different thicknesses, specific performance requirements can be achieved in different areas. When coating the surface of an object with a complex geometry, factors such as the curvature and angle of different parts will affect the uniformity of the coating thickness. Therefore, in order to ensure that the entire surface of the object can be effectively protected by the coating, it may be necessary to splice coatings of different thicknesses. In addition, the thickness of the coating is usually related to the cost, and thicker coatings often require more materials and higher processing costs. Therefore, in some cases, by reasonably splicing coatings of different thicknesses, costs can be reduced while meeting performance requirements.

[0006] Therefore, there is an urgent need to provide a composite coating splicing method to solve the splicing problem of coatings of different thicknesses, thereby reducing costs while meeting performance requirements. Summary of the invention

[0007] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a splicing method, metal parts and applications of composite coatings of different thicknesses. The splicing method provided by the present invention can realize the splicing of composite coatings of different thicknesses. Based on this, not only can the friction coefficient be adjusted to meet different application requirements, but also a diversified combination of material properties can be achieved. Coatings of different thicknesses can provide different performance characteristics, thereby better adapting to changes in the microstructure of the material and improving the overall performance of the material; at the same time, it can better adapt to various complex shapes of metal substrates and improve the coverage effect and protective performance of the coating. Importantly, the splicing method can reduce costs, improve production efficiency, reduce waste in the production process, and meet industrialization needs while meeting performance requirements.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for splicing composite coatings of different thicknesses, the splicing method comprising the following steps:

[0010] Design the shape of the shielding object;

[0011] The shielding object is used to shield the thin layer design area of ​​the metal substrate, and then a composite coating is deposited on the surface of the metal substrate. After deposition to a certain thickness, the shielding object is removed and the deposition of the composite coating is continued. After the deposition is completed, a composite coating with different thicknesses is obtained on the surface of the metal substrate.

[0012] The splicing method provided by the present invention can realize the splicing of composite coatings of different thicknesses, based on which the friction coefficient can be adjusted to meet different application requirements.

[0013] The splicing method provided by the present invention can achieve a diversified combination of material properties, and coatings of different thicknesses can provide different performance characteristics.

[0014] The splicing method provided by the present invention can better adapt to changes in the microstructure of the material and improve the overall performance of the material.

[0015] The splicing method provided by the present invention can better adapt to metal substrates of various complex shapes and improve the covering effect and protective performance of the coating.

[0016] The splicing method provided by the present invention can reduce costs, improve production efficiency, reduce waste in the production process, and meet industrialization needs while meeting performance requirements.

[0017] It should be noted that in order to minimize the impact of thermal stress on materials and coatings during the deposition of the composite coating, the shielding material should be made of a material that is consistent with the metal substrate or has a similar thermal expansion coefficient.

[0018] Preferably, the shielding object is designed in shape according to the shape of the thin layer design area in the metal substrate.

[0019] In the present invention, the shape of the shielding object is flexible and changeable, and is suitable for various complex metal substrates.

[0020] It should be noted that the present invention does not limit the metal substrate. For example, it can be Q235 steel or aluminum alloy.

[0021] Preferably, the shielding object includes any one of a right-angled rectangular shielding object, a circular shielding object or a rounded rectangular shielding object.

[0022] Preferably, the metal substrate is pre-treated before being shielded by the shielding object, and the pre-treatment steps include cleaning and sandblasting.

[0023] In the present invention, cleaning can fundamentally remove dirt such as carbon powder, iron filings, oil stains, etc. formed on the surface of the metal substrate due to mechanical processing, and the surface after cleaning will not be corroded in its entirety or in part.

[0024] Preferably, the specific steps of sandblasting include:

[0025] The surface of the metal substrate to be deposited is ground and then blasted with quartz sand to remove impurities and roughen the surface.

[0026] In the present invention, sandblasting is to polish the metal surface by spraying abrasives such as sand particles at high speed, thereby removing oxide scale, rust, etc. In addition, sandblasting can also roughen the surface of the metal substrate and increase the adhesion between the coating and the substrate.

[0027] Preferably, the mesh size of the quartz sand is 80-120 meshes, for example, it can be 80 meshes, 90 meshes, 100 meshes, 110 meshes or 120 meshes.

[0028] Preferably, during the sandblasting process, the distance between the nozzle of the sandblasting equipment and the metal substrate is 80-120 mm, for example, it can be 80 mm, 90 mm, 100 mm, 110 mm or 120 mm, and the angle between the nozzle and the substrate is 50-70°, for example, it can be 50°, 60° or 70°, etc.

[0029] Preferably, the deposition method of the composite coating comprises a spraying method.

[0030] Preferably, the spraying method comprises an atmospheric plasma thermal spraying method.

[0031] Preferably, in the spraying method, the number of spraying is at least 2 times, for example, it can be 2 times, 3 times, 5 times, 10 times or 15 times.

[0032] Preferably, in the spraying method, the thickness of the composite coating sprayed in a single time is 25 μm-100 μm, for example, 25 μm.

[0033] Preferably, the deposition raw material of the composite coating includes metal ceramic powder or alloy wire.

[0034] Preferably, the cermet powder comprises a metal component and a ceramic component.

[0035] In the present invention, the ceramic component has a relatively high hardness. The addition of the ceramic phase can significantly improve the hardness of the coating, which makes the coating have good wear resistance and can effectively reduce material loss under conditions such as friction and scratching. In addition, the metal substrate provides a certain strength support for the coating, and the reinforcing effect of the ceramic particles further improves the overall strength of the coating. This high-strength property enables the coating to withstand large external forces without easily breaking or peeling off, and performs well when subjected to impact, tensile and other loads.

[0036] Preferably, the metal component in the metal ceramic powder includes a nickel-based metal. Exemplarily, the nickel-based metal may be, for example, Ni60A powder having a mesh size of 300-500 mesh (for example, 300 mesh, 400 mesh, or 500 mesh, etc.).

[0037] In the present invention, nickel-based metal is selected for the corrosive environment because nickel is easily passivated in the air and can quickly form an extremely thin passivation film on the surface of the product to resist the erosion of air and some acids, so the nickel-based coating has a high stability in the air.

[0038] Preferably, the ceramic component in the metal ceramic powder includes Al2O3.

[0039] Preferably, the mesh size of the ceramic component is 400-800 mesh, for example, 400 mesh, 500 mesh, 600 mesh, 700 mesh or 800 mesh.

[0040] Preferably, the mass ratio of the metal component to the ceramic component in the metal ceramic powder is (15-20):(1-5), wherein the selection range of the metal component "15-20" can be, for example, 15, 16, 17, 18, 19 or 20, etc., and the selection range of the ceramic component "1-5" can be, for example, 1, 2, 3, 4 or 5, etc.

[0041] In the present invention, metal components and ceramic components in a suitable mass ratio are used as metal ceramic powder, which helps to reduce defects such as pores and cracks in the composite coating, improve the wear resistance and corrosion resistance of the coating, and thus extend the service life.

[0042] Preferably, the alloy wire comprises Inconel 625 alloy wire.

[0043] Preferably, before the shielding is removed, the deposition thickness of the composite coating is 100-500 μm, for example, 100 μm, 200 μm, 300 μm, 400 μm or 500 μm.

[0044] Preferably, the splicing method comprises the following steps:

[0045] (1) Designing the shape of the shielding object according to the shape of the thin layer design area in the metal substrate;

[0046] (2) Cleaning and sandblasting the surface of the metal substrate, wherein the specific steps of sandblasting include:

[0047] (a) grinding the surface of the metal substrate once with sandpaper of low mesh number (e.g., 200 mesh, etc.), then wiping off the grinding material, then grinding the surface of the metal substrate twice with sandpaper of high mesh number (e.g., 500 mesh, etc.), and then wiping off the grinding material;

[0048] (b) using quartz sand with a mesh number of 80-120 to sandblast the surface of the polished metal substrate to remove impurities and roughen the surface, wherein the distance between the nozzle of the sandblasting equipment and the metal substrate is 80-120 mm, and the angle between the nozzle and the substrate is 50-70°;

[0049] (3) The thin layer design area of ​​the metal substrate is shielded by the shielding object, and then sprayed by atmospheric plasma thermal spraying. The specific steps include:

[0050] Preheat the metal substrate to 80-120°C, for example, 80°C, 90°C, 100°C, 110°C or 120°C, and then spray the metal ceramic powder as a raw material for multiple times, and cool for 3-6 minutes between each spraying, for example, 3 minutes, 4 minutes, 5 minutes or 6 minutes;

[0051] The mass ratio of the metal component to the ceramic component in the metal ceramic powder is (15-20):(1-5), the metal component includes a nickel-based metal, and the ceramic component includes Al2O3;

[0052] (4) After the composite coating is deposited to a certain thickness, the obstruction is removed, and then the surface of the thin layer design area is purged to remove impurities. After the metal substrate is cooled to room temperature, spraying is continued. After the spraying is completed, cooling is performed to obtain composite coatings of different thicknesses on the surface of the metal substrate.

[0053] In a second aspect, the present invention provides a metal component, which is prepared by the splicing method described in the first aspect.

[0054] Preferably, the metal component comprises a metal substrate, and a thin composite coating formed in a thin layer design area of ​​the metal substrate and a thick composite coating formed in a thick layer design area of ​​the metal substrate.

[0055] Preferably, the thin composite coating and the thick composite coating are connected via a transition zone.

[0056] In the present invention, the transition zone between the thin composite coating and the thick composite coating is designed to be a slope, which helps to achieve structural continuity between coatings of different thicknesses and reduce defects.

[0057] In a third aspect, the present invention provides an application of the metal component as described in the second aspect in the field of metal surface treatment.

[0058] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] The splicing method provided by the present invention can realize the splicing of composite coatings of different thicknesses, based on which not only the friction coefficient can be adjusted to meet different application requirements, but also a diversified combination of material properties can be achieved. Coatings of different thicknesses can provide different performance characteristics, thereby better adapting to changes in the microstructure of the material and improving the overall performance of the material; at the same time, it can better adapt to various complex shapes of metal substrates and improve the coverage effect and protective performance of the coating. Importantly, the splicing method can reduce costs, improve production efficiency, reduce waste in the production process, and meet industrialization needs while meeting performance requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 This is a cross-sectional SEM image of a metal component obtained by the splicing method provided in Example 1 of the present invention.

[0062] Figure 2 This is a cross-sectional SEM image of a metal component obtained by the splicing method provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0063] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0064] It should be noted that the room temperature below refers to 25°C.

[0065] Example 1

[0066] This embodiment provides a method for splicing composite coatings of different thicknesses, the splicing method comprising the following steps:

[0067] (1 Design the shape of the shielding object, which is a square shielding object with a shielding area of ​​10 cm × 3 cm.

[0068] (2) Using Q235 sheet as the metal substrate, the surface of the metal substrate is cleaned and sandblasted, and the specific steps of sandblasting include:

[0069] (a) The surface of the metal substrate is polished once with 200-grit sandpaper, and then the polished material is wiped off with a dust-free cloth soaked in anhydrous ethanol. Subsequently, the surface of the metal substrate is polished twice with 500-grit sandpaper, and then the polished material is wiped off with a dust-free cloth soaked in anhydrous ethanol.

[0070] (b) The polished metal substrate surface is sandblasted with quartz sand of mesh number 100 to remove impurities and roughen the surface, wherein the distance between the nozzle of the sandblasting equipment and the metal substrate is 100 mm, and the angle between the nozzle and the substrate is 60°.

[0071] (3) The square shield is used to shield the thin layer design area of ​​the metal substrate, and a clamp is used to fix the square shield and the metal substrate, and the edge of the shield in contact with the metal substrate is chamfered, and then the atmospheric plasma thermal spraying method is used for the first spraying. The specific steps include:

[0072] The metal substrate was preheated to 100° C., and then the metal ceramic powder was sprayed 15 times as the raw material, and cooling was performed for 5 minutes between each two sprayings. After spraying 15 times, the metal substrate was cooled to room temperature.

[0073] The mass ratio of the metal component to the ceramic component in the metal ceramic powder is 17:3, the metal component with a mesh size of 400 is Ni60A, the ceramic component with a mesh size of 500 is Al2O3, and the single spraying thickness is 10 μm.

[0074] (4) After the first spraying is completed, that is, after the coating is deposited to about 150 μm, the square shield is removed, and then nitrogen is used to blow the surface of the thin layer design area to remove impurities. After the metal substrate is cooled to room temperature, the second spraying is continued for 15 times. After the spraying is completed, it is naturally cooled to room temperature to obtain a composite coating of different thicknesses on the surface of the metal substrate.

[0075] This embodiment also provides a metal component, the SEM image of its cross section is as follows Figure 1 As shown, the metal component is prepared by the splicing method as described above.

[0076] The metal component includes a metal substrate, a thin composite coating formed in a thin layer design area of ​​the metal substrate, and a thick composite coating formed in a thick layer design area of ​​the metal substrate. The thickness of the thin composite coating is 150 μm, and the thickness of the thick composite coating is 300 μm. The thin gold composite coating and the thick composite coating are connected through a transition zone.

[0077] Example 2

[0078] This embodiment provides a method for splicing composite coatings of different thicknesses, the splicing method comprising the following steps:

[0079] (1) Design the shape of the shielding object, which is a square shielding object with a shielding area of ​​10 cm × 2 cm.

[0080] (2) Using Q235 sheet as the metal substrate, the surface of the metal substrate is cleaned and sandblasted, and the specific steps of sandblasting include:

[0081] (a) The surface of the metal substrate is polished once with 150-mesh sandpaper, and then the polished material is wiped off with a dust-free cloth soaked in anhydrous ethanol. Subsequently, the surface of the metal substrate is polished twice with 500-mesh sandpaper, and then the polished material is wiped off with a dust-free cloth soaked in anhydrous ethanol.

[0082] (b) The polished metal substrate surface is sandblasted with quartz sand of mesh number 100 to remove impurities and roughen the surface, wherein the distance between the nozzle of the sandblasting equipment and the metal substrate is 80 mm, and the angle between the nozzle and the substrate is 60°.

[0083] (3) The square shield is used to shield the thin layer design area of ​​the metal substrate, and a clamp is used to fix the square shield and the metal substrate, and the edge of the shield in contact with the metal substrate is chamfered, and then the atmospheric plasma thermal spraying method is used for the first spraying. The specific steps include:

[0084] The metal substrate was preheated to 100°C, and then Inconel 625 alloy wire was sprayed three times as raw material, and cooled for 5 minutes after two sprayings. The thickness of a single spraying was about 50 μm.

[0085] (4) After the first spraying is completed, that is, after the composite coating is deposited to 150 μm, the square shield is removed, and then nitrogen is used to blow the surface of the thin layer design area to remove impurities. After the metal substrate is cooled to room temperature, the second spraying is continued for 5 times. After the spraying is completed, it is naturally cooled to room temperature to obtain composite coatings of different thicknesses on the surface of the metal substrate.

[0086] This embodiment also provides a metal component, the SEM image of its cross section is as follows Figure 2As shown, the metal component is prepared by the splicing method as described above.

[0087] The metal component includes a metal substrate, a thin composite coating formed in a thin layer design area of ​​the metal substrate, and a thick composite coating formed in a thick layer design area of ​​the metal substrate. The thickness of the thin composite coating is 250 μm, and the thickness of the thick composite coating is 400 μm. The thin gold composite coating and the thick composite coating are connected through a transition zone.

[0088] Example 3

[0089] The difference between this embodiment and embodiment 1 is that the mass ratio of the metal component to the ceramic component in the metal ceramic powder is 15:1.

[0090] The rest of the splicing methods and parameters remain the same as those in Example 1.

[0091] Example 4

[0092] The difference between this embodiment and embodiment 1 is that the mass ratio of the metal component to the ceramic component in the metal ceramic powder is 20:5.

[0093] The rest of the splicing methods and parameters remain the same as those in Example 1.

[0094] Example 5

[0095] The difference between this embodiment and embodiment 1 is that the metal ceramic powder contains only metal components.

[0096] The rest of the splicing methods and parameters remain the same as those in Example 1.

[0097] Comparative Example 1

[0098] The difference between this comparative example and Example 1 is that no shielding object is provided, that is, the thickness of the composite coating is uniform, which is 300 μm.

[0099] The rest of the splicing methods and parameters remain the same as those in Example 1.

[0100] analyze

[0101] It can be seen from Example 1 and Example 3-4 that metal components and ceramic components of suitable mass ratio as raw materials of composite coatings are helpful to improve the wear resistance of coatings and extend service life. If the mass ratio is too small, the ceramic phase distribution in the coating is uneven, it is difficult to form an effective reinforcement structure, and the microhardness of the coating will be significantly reduced. The reduction in hardness makes the coating more susceptible to scratches and wear when in contact with other objects; if the mass ratio is relatively large, the ceramic phase distribution in the coating is too concentrated, making it difficult to form a uniform microstructure. Coatings with high ceramic content usually have higher porosity. The bonding between ceramic particles and metal matrix is ​​often not as tight as the bonding between metals. When the ceramic content is too high, the pores in the coating are more likely to form and expand. The presence of pores will reduce the density and strength of the coating, making the coating prone to fracture and damage when subjected to load. At the same time, the pores will also become channels for corrosive media, accelerating the corrosion and failure of the coating.

[0102] It can be seen from Example 1 and Example 5 that if the metal ceramic powder contains only metal components, the lack of ceramic phase means that the hardness of the coating is relatively low. Ceramic materials generally have the characteristics of high hardness and can effectively resist wear. Metal coatings without ceramics are more prone to scratches, wear pits and other damage when facing friction and scratches, thereby reducing the service life of the coating. In addition, although some metals themselves have a certain corrosion resistance, their corrosion resistance is often weaker than that of ceramics. Ceramics usually have good chemical stability and can resist erosion by corrosive media such as acids, alkalis, and salts. Metal coatings without ceramics are prone to chemical reactions in corrosive environments, causing the coating to be corroded and damaged, and lose their protective effect on the substrate. .

[0103] It can be seen from Example 1 and Comparative Example 1 that if composite coatings of different thicknesses are not designed, the requirements of coatings of different thicknesses cannot be met, and the design requirements of the workpiece cannot be adapted, resulting in incomplete coating coverage, which is not conducive to the mechanical properties and anti-corrosion performance of the material.

[0104] The applicant declares that the present invention illustrates the process method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for splicing composite coatings of different thicknesses, characterized in that: The splicing method comprises the following steps: Design the shape of the shielding object; The shielding object is used to shield the thin layer design area of ​​the metal substrate, and then a composite coating is deposited on the surface of the metal substrate. After deposition to a certain thickness, the shielding object is removed and the deposition of the composite coating is continued. After the deposition is completed, a composite coating with different thicknesses is obtained on the surface of the metal substrate.

2. The splicing method according to claim 1, characterized in that: The shield is designed in shape according to the shape of the thin layer design area in the metal substrate; And / or, the obstruction includes any one of a right-angled rectangular obstruction, a circular obstruction or a rounded rectangular obstruction.

3. The splicing method according to claim 1, characterized in that: The metal substrate is pre-treated before being shielded by the shielding object, and the pre-treatment steps include cleaning and sandblasting; And / or, the specific steps of sandblasting include: The surface of the metal substrate to be deposited is ground and then sandblasted with quartz sand to remove impurities and roughen the surface; And / or, the mesh number of the quartz sand is 80-120 mesh; And / or, during the sandblasting process, the distance between the nozzle of the sandblasting equipment and the metal substrate is 80-120 mm, and the angle between the nozzle and the substrate is 50-70°.

4. The splicing method according to claim 1, characterized in that: The deposition method of the composite coating includes a spraying method; and / or, the spraying method comprises an atmospheric plasma thermal spraying method; And / or, in the spraying method, the number of spraying is at least 2 times; And / or, in the spraying method, the thickness of the composite coating sprayed in a single time is 25-100 μm.

5. The splicing method according to claim 1, characterized in that: The deposition raw materials of the composite coating include metal ceramic powder or alloy wire; and / or, the metal ceramic powder comprises a metal component and a ceramic component; and / or, the metal component in the metal ceramic powder includes a nickel-based metal; and / or, the ceramic component in the metal ceramic powder includes Al2O3; And / or, the mass ratio of the metal component to the ceramic component in the metal ceramic powder is (15-20):(1-5).

6. The splicing method according to claim 1, characterized in that: Before the mask is removed, the composite coating is deposited to a thickness of 100-500 μm.

7. The splicing method according to claim 1, characterized in that: The splicing method comprises the following steps: (1) Designing the shape of the shielding object according to the shape of the thin layer design area in the metal substrate; (2) Cleaning and sandblasting the surface of the metal substrate, wherein the specific steps of sandblasting include: (a) grinding the surface of the metal substrate once with low-grit sandpaper, then wiping off the grinding material, then grinding the surface of the metal substrate twice with high-grit sandpaper, and then wiping off the grinding material; (b) using quartz sand with a mesh number of 80-120 to sandblast the surface of the polished metal substrate to remove impurities and roughen the surface, wherein the distance between the nozzle of the sandblasting equipment and the metal substrate is 80-120 mm, and the angle between the nozzle and the substrate is 50-70°; (3) The thin layer design area of ​​the metal substrate is shielded by the shielding object, and then sprayed by atmospheric plasma thermal spraying. The specific steps include: Preheat the metal substrate to 80-120℃, then spray the metal ceramic powder multiple times, and cool for 3-6 minutes between each spraying; The mass ratio of the metal component to the ceramic component in the metal ceramic powder is (15-20):(1-5), the metal component includes a nickel-based metal, and the ceramic component includes Al2O3; (4) After the composite coating is deposited to a certain thickness, the obstruction is removed, and then the surface of the thin layer design area is purged to remove impurities. After the metal substrate is cooled to room temperature, spraying is continued. After the spraying is completed, cooling is performed to obtain composite coatings of different thicknesses on the surface of the metal substrate.

8. A metal component, characterized in that: The metal component is prepared by the splicing method according to any one of claims 1 to 7.

9. The metal component according to claim 8, characterized in that The metal component includes a metal substrate, and a thin composite coating formed in a thin layer design area of ​​the metal substrate and a thick composite coating formed in a thick layer design area of ​​the metal substrate; And / or, the thin composite coating and the thick composite coating are connected via a transition zone.

10. Use of the metal component according to claim 8 or 9 in the field of metal surface treatment.

Images