Preparation method of hard alloy coating

Abstract

The embodiment of the invention provides a preparation method of a hard alloy coating, which comprises the following steps: carrying out sand blasting treatment on the surface of a workpiece, and cleaning with acetone to remove residual gravels on the surface of the workpiece after the sand blasting treatment; wC-25Co powder is adopted as a hard alloy coating component and is cold-sprayed on the surface of a workpiece, and a hard alloy coating is obtained on the surface of the workpiece; and after the workpiece is naturally cooled to the room temperature, the hard alloy coating on the surface of the workpiece is subjected to stirring friction treatment. According to the method, the hard alloy coating prepared on the basis of cold spraying and friction stir treatment can be achieved. And under the action of stirring friction treatment, the hard alloy coating with uniformly distributed ceramic phases can be obtained, the component uniformity of the cold spraying hard alloy is improved, and the properties such as erosion resistance of the coating are improved.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the field of surface engineering technology, and specifically relate to a method for preparing a cemented carbide coating. Background Art

[0002] Cold spraying is a low-temperature and high-pressure solid phase deposition technology, which has the advantages of unlimited thickness of deposited coating, no phase change of materials, small residual stress and compressive stress, etc. Since cold spray particles are combined by plastic deformation of particles, and cemented carbide has high hardness and poor plastic deformation ability, it is difficult to obtain a coating with high bonding strength and good uniformity.

[0003] Traditional post-spraying treatment methods, such as aging or mechanical deformation, have problems with adverse thermal effects or high costs. In order to improve the defects of low bonding strength and poor uniformity of cemented carbide coatings prepared by cold spraying technology, a new cemented carbide coating homogenization technology needs to be developed. Summary of the invention

[0004] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a method for preparing a cemented carbide coating.

[0005] One aspect of an embodiment of the present disclosure provides a method for preparing a cemented carbide coating, comprising:

[0006] The workpiece surface is sandblasted and cleaned with acetone to remove the grit remaining on the workpiece surface after sandblasting;

[0007] WC-25Co powder is used as a cemented carbide coating component and is cold sprayed on the workpiece surface to obtain a cemented carbide coating on the workpiece surface;

[0008] After the workpiece is naturally cooled to room temperature, the cemented carbide coating on the workpiece surface is subjected to friction stir treatment.

[0009] Optionally, the particle size of the WC-25Co powder is 10 to 50 microns.

[0010] Optionally, a hard alloy coating with a thickness of 200 to 300 microns is sprayed on the surface of the workpiece.

[0011] Optionally, the gas pressure during the cold spraying process is 4-5 MPa.

[0012] Optionally, the gas temperature during the cold spraying process is 700-800°C.

[0013] Optionally, the spraying distance during the cold spraying process is 20 to 30 mm.

[0014] Optionally, the stirring head rotates at a speed of 600 rpm during the friction stir treatment.

[0015] Optionally, the residence time of the stirring head during the friction stir treatment is 5 seconds.

[0016] Optionally, during the friction stir treatment, the downward pressing speed of the stirring head is 1 mm / min.

[0017] Optionally, during the friction stir treatment, the stirring head is pressed down to a depth of 0.1 mm.

[0018] The beneficial effects of the embodiments of the present disclosure include:

[0019] In the present disclosure, the above method can realize a hard alloy coating prepared by cold spraying + friction stir treatment. Under the action of friction stir treatment, a hard alloy coating with uniform distribution of ceramic phase can be obtained, the uniformity of cold sprayed hard alloy composition is improved, and the erosion resistance and other properties of the coating are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a process for preparing a cemented carbide coating according to an embodiment of the present disclosure;

[0021] Figure 2 The present invention is a schematic diagram of a method for preparing a cemented carbide coating according to an embodiment of the present invention; the diagram schematically shows the processing process of the layer by a friction stirring head. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0023] The following is a further detailed description of the implementation methods of the present application in conjunction with the accompanying drawings and examples. The detailed descriptions and drawings of the following examples are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments. In the description of the present application, it should be noted that, unless otherwise specified, the meaning of "multiple" is more than two; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inside", "outside", etc. is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the error tolerance range. "Parallel" is not parallel in the strict sense, but within the error tolerance range.

[0024] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0025] like Figure 1 As shown, a method for preparing a cemented carbide coating comprises:

[0026] S101, sandblasting the surface of the workpiece, and cleaning it with acetone to remove the grit remaining on the surface of the workpiece after the sandblasting. The workpiece includes a TC4 titanium alloy part or a 2024 aluminum alloy part.

[0027] S102, using WC-25Co powder as a cemented carbide coating component, and cold spraying it on the workpiece surface to obtain a cemented carbide coating on the workpiece surface.

[0028] S103, after the workpiece is naturally cooled to room temperature, a friction stir treatment is performed on the cemented carbide coating on the surface of the workpiece.

[0029] In the present disclosure, through the above method, a cemented carbide coating prepared based on cold spraying + friction stir treatment can be achieved. Under the action of friction stir treatment, a cemented carbide coating with uniform distribution of ceramic phase can be obtained, the uniformity of cold sprayed cemented carbide components can be improved, and the erosion resistance and other properties of the coating can be improved. Specifically, the violent mechanical stirring action of the friction stir head will cause continuous dynamic recrystallization of the coating, promote grain refinement, improve the distribution of ceramic phases in the cemented carbide coating, and enhance the uniformity of the coating. Furthermore, compared with methods such as ultrasonic impact method and laser impact, friction stir treatment has lower cost and less deformation of the workpiece. Compared with traditional heat treatment methods, friction stir treatment has low temperature and small heat-affected zone, which effectively avoids oxidation of the workpiece.

[0030] In some embodiments, the workpiece surface is sandblasted to achieve a surface roughness Ra of 10 to 300 microns.

[0031] In some embodiments, the workpiece includes a TC4 titanium alloy component or a 2024 aluminum alloy component.

[0032] In some embodiments, the WC-25Co powder has a particle size of 10 to 50 microns.

[0033] In some embodiments, a cemented carbide coating having a thickness of 200 to 300 microns is sprayed on the surface of the workpiece.

[0034] In some embodiments, the gas pressure during the cold spraying process is 4-5 MPa.

[0035] In some embodiments, the gas temperature during the cold spraying process is 700-800°C.

[0036] In some embodiments, the spraying distance during the cold spraying process is 20-30 mm.

[0037] In some embodiments, the stirring head rotates at a speed of 600 rpm during the friction stir treatment.

[0038] In some embodiments, the residence time of the stirring head during the friction stir treatment is 5 seconds.

[0039] In some embodiments, the downward pressing speed of the stirring head during the friction stir treatment is 1 mm / min.

[0040] In some embodiments, the stirring head is pressed down to a depth of 0.1 mm during the friction stir treatment.

[0041] In some embodiments, the method further includes post-processing the cold spray coating by friction stir processing, including removal, anti-corrosion coating application, etc.

[0042] refer to Figure 2 , the specific examples provided by the present disclosure include:

[0043] Example 1: Preparation of coating on the surface of TC4 titanium alloy component. WC-25Co powder is used as spraying material.

[0044] Before spraying, the surface of the TC4 titanium alloy parts was sandblasted to make the surface of the workpiece present a uniform rough state without metallic luster, and was cleaned with acetone to remove the grit remaining on the surface of the workpiece after sandblasting.

[0045] Furthermore, WC-25Co powder was used to cold spray a WC-25Co coating with a thickness of 200 to 300 microns on the surface of the TC4 titanium alloy component. The process parameters used for cold spraying are: gas pressure of 5MPa, gas temperature of 800℃, spraying distance of 30mm, and spraying was stopped until the thickness of the spray repair area exceeded the original workpiece surface by about 0.2mm. Then, a stir friction head was used to stir friction the coating. The process parameters used for stir friction treatment are: stirring head speed of 600rpm, dwell time of 5s, pressing speed of 1mm / min, and pressing depth of 0.1mm.

[0046] Example 2: Preparation of coating on the surface of 2024 aluminum alloy component. WC-25Co powder is used as spraying material.

[0047] Before spraying, the surface of the 2024 aluminum alloy parts was sandblasted to make the surface of the workpiece present a uniform rough state without metallic luster, and was cleaned with acetone to remove the grit remaining on the surface of the workpiece after sandblasting.

[0048] Furthermore, WC-25Co powder was used to cold spray a WC-25Co coating with a thickness of 200 to 300 microns on the surface of the 2024 aluminum alloy parts. The process parameters used for cold spraying are: gas pressure of 4MPa, gas temperature of 700℃, spraying distance of 20mm, and spraying was stopped until the thickness of the spray repair area exceeded the original workpiece surface by about 0.2mm. Then, a stir friction head was used to stir friction the coating. The process parameters used for stir friction treatment are: stirring head speed of 600rpm, dwell time of 5s, pressing speed of 1mm / min, and pressing depth of 0.1mm.

[0049] As can be seen from the above embodiments, the present invention discloses a method for homogenizing cemented carbide, which performs post-treatment of cold spray coatings through friction stir treatment, removal, anti-corrosion coating coating, etc. It is mainly used to improve the density of cold sprayed cemented carbide coatings and promote the uniform distribution of ceramic phases, and has the advantages of low cost and small heat-affected zone. This method is particularly suitable for workpieces with anti-erosion requirements, and can effectively improve the uniformity of cemented carbide coatings and improve the service performance of workpieces.

[0050] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A method for preparing a cemented carbide coating, characterized in that: include: The workpiece surface is sandblasted and cleaned with acetone to remove the grit remaining on the workpiece surface after sandblasting; WC-25Co powder is used as a cemented carbide coating component and is cold sprayed on the workpiece surface to obtain a cemented carbide coating on the workpiece surface; After the workpiece is naturally cooled to room temperature, the cemented carbide coating on the workpiece surface is subjected to friction stir treatment.

2. The method for preparing a cemented carbide coating according to claim 1, characterized in that: The particle size of the WC-25Co powder is 10 to 50 microns.

3. The method for preparing a cemented carbide coating according to claim 1, characterized in that: A hard alloy coating with a thickness of 200 to 300 microns is sprayed on the surface of the workpiece.

4. The method for preparing a cemented carbide coating according to claim 1, characterized in that: The gas pressure during cold spraying is 4-5 MPa.

5. The method for preparing a cemented carbide coating according to claim 1, characterized in that: The gas temperature during cold spraying is 700-800°C.

6. The method for preparing a cemented carbide coating according to claim 1, characterized in that: The spraying distance during the cold spraying process is 20 to 30 mm.

7. The method for preparing a cemented carbide coating according to claim 1, characterized in that: The stirring head speed during the friction stir treatment was 600 rpm.

8. The method for preparing a cemented carbide coating according to claim 1, characterized in that: The residence time of the stirring head during the friction stir treatment was 5 s.

9. The method for preparing a cemented carbide coating according to claim 1, characterized in that: During the friction stir treatment, the downward pressure speed of the stirring head was 1 mm / min.

10. The method for preparing a cemented carbide coating according to claim 1, characterized in that: During the friction stir treatment, the pressing depth of the stirring head was 0.1 mm.

Images