Preparation method of coating with high adhesive force

Abstract

The invention provides a preparation method of a coating with high adhesive force. The preparation method comprises the following steps: providing a spare part base material and coating powder; roughness treatment is conducted on the spare part base material, and the treated spare part base material is obtained; and coating powder is used for conducting spraying operation on the treated spare part base metal, and the coating is obtained. According to the preparation method of the coating with high adhesive force, the adhesive force of the coating on the surface of the spare part can be improved and the service life of the coating is prolonged on the premise of controlling the roughness of the surface of the spare part and remarkably reducing the loss of base metal of the spare part, so that the overall service life of the spare part is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of coating processing, in particular to a method for preparing a coating with high adhesion. Background Art

[0002] In the prior art, a simple sandblasting process is generally used for surface treatment of products in high-temperature vacuum chambers, which can only ensure that the plasma spray coating can adhere to the surface of the spare parts. However, this treatment method often ignores the strict control of the adhesion between the surface of the spare parts and the coating, resulting in the coating being easily delaminated and falling off within the set service life during actual use, which seriously affects the stability and reliability of the product.

[0003] In order to solve the problem of stratification and shedding of the surface coating of spare parts, the main approach currently adopted in the industry is to increase the roughness of the surface of spare parts. The specific approach is to use sandblasting materials with low mesh counts and maintain a high sandblasting pressure, so that the surface roughness of the spare parts before coating is very large. Although this ensures the adhesion of the coating, the roughness of the surface of the spare parts is usually formed by sandblasting with white corundum. The greater the required roughness, the greater the demand for white corundum particles, the greater the sandblasting pressure, and the greater the loss of the spare parts base material, resulting in a significant reduction in the service life of the spare parts base material, causing great economic losses.

[0004] Therefore, there is an urgent need for a method for preparing a coating with high adhesion, which can improve the adhesion of the coating on the surface of the spare parts while controlling the roughness of the spare parts surface and significantly reducing the loss of the spare parts base material, thereby increasing the service life of the coating and thus extending the overall service life of the spare parts. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a method for preparing a coating with high adhesion, which improves the adhesion of the coating on the surface of the spare part while controlling the roughness of the spare part surface and significantly reducing the loss of the spare part base material, thereby increasing the service life of the coating and thus extending the overall service life of the spare part.

[0006] The present invention provides a method for preparing a coating with high adhesion, comprising the following steps:

[0007] Provide spare parts base material and coating powder;

[0008] Performing roughness treatment on the spare part base material to obtain the treated spare part base material;

[0009] The treated spare part base material is sprayed with coating powder to obtain a coating.

[0010] As a further improvement of the present invention, the coating powder comprises Y2O3, the particle size is 20 to 50 μm, and the preparation method comprises: yttrium nitrate dissolution, filtration, ammonia precipitation, filter pressing, hydrothermal, drying, calcination, grinding, surface modification, granulation, demagnetization, degumming, screening, mixing, and packaging processes.

[0011] As a further improvement of the present invention, the spare part mother material includes a metal mother material and a ceramic mother material, and the roughness treatment of the spare part mother material includes cleaning, sandblasting and preheating operations on the spare part mother material.

[0012] As a further improvement of the present invention, the roughness of the metal base material after roughness treatment is 5 to 7 μm, and the roughness of the ceramic base material after roughness treatment is 3 to 5 μm.

[0013] As a further improvement of the present invention, the cleaning operation includes: cleaning the metal mother material with mixed acid, surfactant and DI water, and cleaning the ceramic mother material with alkali, mixed acid, surfactant and DI water.

[0014] As a further improvement of the present invention, the sandblasting particles used in the sandblasting operation are composed of Al2O3, the sandblasting pressure is 0.2-0.6 MPa, and the particle size is 46-400 meshes.

[0015] As a further improvement of the present invention, in the preheating operation, the preheating temperature of the metal base material is 60°C, and the preheating temperature of the ceramic base material is 80°C.

[0016] As a further improvement of the present invention, the voltage of the spraying operation is 60-100V, the current is 500-700A, the powder feeding rate is 20-40%, the spray distance is 13-18mm, the flow rate of gas H2 is 6-10NLPM, and the flow rate of gas Ar is 30-50NLPM.

[0017] As a further improvement of the present invention, in the spraying operation, the powder feeding rate is first controlled to be 20-25% so that the powder melts evenly and thoroughly, and then the powder feeding rate is controlled to be 30-40%.

[0018] As a further improvement of the present invention, the coating thickness of the metal mother material is 100-400 mm, the coating bonding strength is above 12 MPa, and the porosity is 2-6%; the coating thickness of the ceramic mother material is 100-600 mm, the coating bonding strength is above 4.5 MPa, and the porosity is 2-6%.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention provides a method for preparing a coating with high adhesion, which can improve the adhesion of the coating on the surface of the spare part while controlling the roughness of the spare part surface and significantly reducing the loss of the spare part base material, thereby increasing the service life of the coating and thus extending the overall service life of the spare part. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flowchart of a method for preparing a coating with high adhesion disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the present invention will be combined with the attached Figure 1 , a clear and complete description of the technical solutions in the embodiments of the present invention is given. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments, wherein steps S1, S2... in the embodiments described in the present invention do not limit the only execution steps of the present invention; the basic principles of the present invention defined in the description of the present invention can be applied to other implementation schemes, variations, improvements, equivalent schemes, and other technical solutions that do not deviate from the spirit and scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] The present invention finds that the adhesion of the coating is directly related to the hardness of the spare part base material and the roughness of the surface of the spare part base material. Under the same roughness conditions, the higher the base material hardness within a certain range, the higher the adhesion of the coating; under the same spare part base material conditions, the greater the roughness of the spare part base material, the greater the adhesion of the coating. The principle is that, first, the mechanism of the influence of the surface roughness of the spare part on the adhesion of the coating is that the coating penetrates into the gaps between the rough surface during the spraying process to form a mechanical interlock. The surface gaps with large roughness are more and deeper, and the mechanical interlocking effect formed is strong, so it has a higher adhesion; secondly, the increase in roughness will cause the surface area of ​​the spare part to increase accordingly. The larger the real surface area, the greater the contact area between the coating and the spare part, which improves the interfacial adhesion and chemical bond force between the coating and the spare part. Finally, the corrosion products produced when the spare part with a larger roughness is corroded are not easy to diffuse, thereby reducing the influence of the generated corrosion products on the reduction of adhesion.

[0024] However, the roughness of the spare parts surface is usually formed by sandblasting with white corundum. The greater the required roughness, the larger the white corundum particles required, the greater the sandblasting pressure required, and the greater the loss of the parent material, resulting in a significant reduction in the service life of the spare parts parent material and causing great economic losses. In other words, the larger the surface roughness of the spare parts is, the better.

[0025] Therefore, the present invention develops the best roughness for metal and ceramic base materials within an acceptable loss rate range, and adopts the high-adhesion coating preparation method provided in the embodiment of the present invention. The industry standard for coating adhesion is: the adhesion strength of ceramic base material coatings after finishing is 3-6MPa, and the adhesion strength of metal base material coatings is above 10MPa. According to the method of the present invention, the final adhesion strength of ceramic base material coatings can reach above 4.5MPa, and the adhesion strength of metal spare parts surface coatings can reach above 12MPa.

[0026] like Figure 1 As shown, the present invention provides a method for preparing a coating with high adhesion, comprising the following steps:

[0027] S1: Provide spare parts base material and coating powder;

[0028] Preferably, the coating powder comprises Y2O3, the particle size is 20 to 50 μm, and the preparation method comprises: yttrium nitrate dissolution, filtration, ammonia precipitation, filter pressing, hydrothermal, drying, calcination, grinding, surface modification, granulation, demagnetization, degumming, screening, mixing, packaging and other processes.

[0029] Preferably, the spare part base material includes a metal base material and a ceramic base material.

[0030] S2: performing roughness treatment on the spare part base material to obtain the treated spare part base material;

[0031] Preferably, the roughness treatment of the spare part base material includes cleaning, sandblasting and preheating the spare part base material.

[0032] Preferably, the cleaning operation comprises: cleaning the metal base material with mixed acid, surfactant and DI water, and cleaning the ceramic base material with alkali, mixed acid, surfactant and DI water.

[0033] Preferably, the sandblasting particles used in the sandblasting operation are composed of Al2O3, the sandblasting pressure is 0.2-0.6 MPa, and the particle size is 46-400 mesh.

[0034] Preferably, in the preheating operation, the preheating temperature of the metal base material is 60°C, and the preheating temperature of the ceramic base material is 80°C.

[0035] Preferably, the roughness of the metal base material after roughness treatment is 5 to 7 μm, and the roughness of the ceramic base material after roughness treatment is 3 to 5 μm.

[0036] S3: spraying the processed spare part base material with coating powder to obtain a coating.

[0037] Preferably, the voltage of the spraying operation is 60-100V, the current is 500-700A, the powder feeding rate is 20-40%, the spray distance is 13-18mm, the flow rate of the gas H2 is 6-10NLPM, and the flow rate of the gas Ar is 30-50NLPM.

[0038] Preferably, in the spraying operation, the powder feeding rate is controlled at 20-25% in the first few passes to make the powder melt more evenly and thoroughly, the surface of the base material more uniform, and the adhesion higher. In the later stage, the powder feeding rate is controlled at 30-40% to improve the powder coating efficiency and save operation time.

[0039] Preferably, the coating thickness of the metal mother material is 100-400 mm, the coating bonding strength is above 12 MPa, and the porosity is 2-6%; the coating thickness of the ceramic mother material is 100-600 mm, the coating bonding strength is above 4.5 MPa, and the porosity is 2-6%.

[0040] The following is specifically described by examples:

[0041] Example 1

[0042] S1: Provide metal base material and coating powder;

[0043] The coating powder comprises Y2O3, the particle size is 20 to 50 μm, and the preparation method comprises the following steps: yttrium nitrate dissolution, filtration, ammonia precipitation, filter pressing, hydrothermal treatment, drying, calcination, grinding, surface modification, granulation, demagnetization, degumming, screening, mixing and packaging.

[0044] S2: performing roughness treatment on the metal base material to obtain a treated metal base material;

[0045] It includes cleaning operations, sandblasting operations, and preheating operations on the metal base material.

[0046] The cleaning operation includes: cleaning the metal base material with mixed acid, surfactant and DI water.

[0047] The sandblasting particle composition of the sandblasting operation is Al2O3, the sandblasting pressure is 0.2~0.6MPa, and the particle size is 46~400 mesh.

[0048] The preheating temperature of the preheating operation is 60°C.

[0049] The roughness of the metal base material after roughness treatment is 5 to 7 μm.

[0050] S3: spraying the treated metal base material with coating powder to obtain a coating.

[0051] The voltage of the spraying operation is 60-100V, the current is 500-700A, the powder feeding rate is 20-40%, the spray distance is 13-18mm, the flow rate of the gas H2 is 6-10NLPM, and the flow rate of the gas Ar is 30-50NLPM.

[0052] In the first few passes of the spraying operation, the powder feeding rate is controlled at 20-25% to make the powder melt more evenly and thoroughly, the surface of the base material more uniform, and the adhesion higher. In the later stage, the powder feeding rate is controlled at 30-40% to improve the powdering efficiency and save operation time.

[0053] Example 2

[0054] S1: Provide ceramic base material and coating powder;

[0055] The coating powder comprises Y2O3, the particle size is 20 to 50 μm, and the preparation method comprises the following steps: yttrium nitrate dissolution, filtration, ammonia precipitation, filter pressing, hydrothermal treatment, drying, calcination, grinding, surface modification, granulation, demagnetization, degumming, screening, mixing and packaging.

[0056] S2: performing roughness treatment on the ceramic base material to obtain a treated ceramic base material;

[0057] It includes cleaning operations, sandblasting operations, and preheating operations on the ceramic base material.

[0058] The cleaning operation includes: using alkali, mixed acid, surfactant and DI water to clean the ceramic base material.

[0059] The sandblasting particle composition of the sandblasting operation is Al2O3, the sandblasting pressure is 0.2~0.6MPa, and the particle size is 46~400 mesh.

[0060] The preheating temperature of the preheating operation is 80°C.

[0061] The roughness of the ceramic base material after treatment is 3 to 5 μm.

[0062] S3: spraying the treated ceramic base material with coating powder to obtain a coating.

[0063] The voltage of the spraying operation is 60-100V, the current is 500-700A, the powder feeding rate is 20-40%, the spray distance is 13-18mm, the flow rate of the gas H2 is 6-10NLPM, and the flow rate of the gas Ar is 30-50NLPM.

[0064] In the first few passes of the spraying operation, the powder feeding rate is controlled at 20-25% to make the powder melt more evenly and thoroughly, the surface of the base material more uniform, and the adhesion higher. In the later stage, the powder feeding rate is controlled at 30-40% to improve the powdering efficiency and save operation time.

[0065] Comparative Example 1

[0066] In this comparative example, compared with Example 1, the only difference is that in step S2, the roughness of the metal base material is 2-4 μm; in step S3, the powder feeding rate of the spraying operation is 30-40%, the spray distance is 16-18 mm, and the flow rate of the gas H2 is 8-10 NLPM. The remaining steps are the same as in Example 1.

[0067] Comparative Example 2

[0068] In this comparative example, compared with Example 2, the only difference is that in step S2, the roughness of the ceramic base material is 1-2 μm; in step S3, the powder feeding rate of the spraying operation is 30-40%, the spray distance is 16-18 mm, and the flow rate of the gas H2 is 8-10 NLMPM. The remaining steps are the same as in Example 2.

[0069] For the above examples and comparative examples, the adhesion of the coating was tested using an adhesion tester, and the test results are shown in Table 1:

[0070] Table 1:

[0071] Example / Comparative Example Coating Adhesion(MPa) Example 1 10.34～13.64 Example 2 4.75～6.32 Comparative Example 1 6.28～8.54 Comparative Example 2 2.12～3.65

[0072] It can be seen from Example 1 and Comparative Example 1 in Table 1 that, for a metal base material, the adhesion of the coating obtained by the coating preparation method of Example 1 of the present invention is significantly better than that of the coating preparation method of Comparative Example 1. In particular, Example 1 controls the surface roughness of the base material to 5-7 μm, and the adhesion of the coating obtained is significantly better than the adhesion of the coating under the base material surface roughness of Comparative Example 1.

[0073] It can be seen from Example 2 and Comparative Example 2 in Table 1 that, for a ceramic base material, the adhesion of the coating obtained by the coating preparation method of Example 2 of the present invention is significantly better than that of the coating preparation method of Comparative Example 2. In particular, Example 2 controls the surface roughness of the base material to 3-5 μm, and the adhesion of the coating obtained is significantly better than the adhesion of the coating under the base material surface roughness of Comparative Example 2.

[0074] It can be seen that the high-adhesion coating preparation method provided by the present invention can improve the adhesion of the coating on the surface of the spare parts while controlling the roughness of the spare parts surface and significantly reducing the loss of the spare parts base material, thereby improving the service life of the coating and extending the overall service life of the spare parts.

Claims

1. A method for preparing a coating with high adhesion, characterized in that: The following steps are involved: Provide spare parts base material and coating powder; Performing roughness treatment on the spare part base material to obtain the treated spare part base material; The treated spare part base material is sprayed with coating powder to obtain a coating.

2. The method for preparing a coating with high adhesion according to claim 1, characterized in that: The coating powder comprises Y2O3, and the particle size is 20 to 50 μm. The preparation method comprises the following steps: yttrium nitrate dissolution, filtration, ammonia precipitation, filter pressing, hydrothermal, drying, calcination, grinding, surface modification, granulation, demagnetization, degumming, screening, mixing, and packaging.

3. The method for preparing a coating with high adhesion according to claim 1, characterized in that: The spare parts mother material includes a metal mother material and a ceramic mother material, and the roughness treatment of the spare parts mother material includes cleaning, sandblasting and preheating the spare parts mother material.

4. The method for preparing a coating with high adhesion according to claim 3, characterized in that: The roughness of the metal base material after the roughness treatment is 5 to 7 μm, and the roughness of the ceramic base material after the roughness treatment is 3 to 5 μm.

5. The method for preparing a coating with high adhesion according to claim 3, characterized in that: The cleaning operation includes: cleaning the metal base material with mixed acid, surfactant and DI water, and cleaning the ceramic base material with alkali, mixed acid, surfactant and DI water.

6. The method for preparing a coating with high adhesion according to claim 3, characterized in that: The sandblasting particles used in the sandblasting operation have a composition of Al2O3, a sandblasting pressure of 0.2-0.6 MPa, and a particle size of 46-400 meshes.

7. The method for preparing a coating with high adhesion according to claim 3, characterized in that: In the preheating operation, the preheating temperature of the metal base material is 60°C, and the preheating temperature of the ceramic base material is 80°C.

8. The method for preparing a coating with high adhesion according to claim 1, characterized in that: The voltage of the spraying operation is 60-100V, the current is 500-700A, the powder feeding rate is 20-40%, the spray distance is 13-18mm, the flow rate of the gas H2 is 6-10NLPM, and the flow rate of the gas Ar is 30-50NLPM.

9. The method for preparing a coating with high adhesion according to claim 8, characterized in that: In the spraying operation, the powder feeding rate is first controlled to be 20-25% so that the powder melts evenly and thoroughly, and then the powder feeding rate is controlled to be 30-40%.

10. The method for preparing a coating with high adhesion according to claim 3, characterized in that: The coating thickness of the metal matrix is ​​100-400 mm, the coating bonding strength is above 12 MPa, and the porosity is 2-6%; the coating thickness of the ceramic matrix is ​​100-600 mm, the coating bonding strength is above 4.5 MPa, and the porosity is 2-6%.

Images