Sealing part with three-dimensional network structure surface coating and preparation method of sealing part

Abstract

The invention provides a sealing component with a surface coating of a three-dimensional network structure and a preparation method, the sealing component comprises a base body and the surface coating, the surface coating is the coating of the three-dimensional network structure, and the three-dimensional space network structure of the coating is independent of the base body. According to the preparation method of the sealing component with the three-dimensional network structure surface coating, the three-dimensional space network structure of the coating is independent of a base body and is combined with the base body through the thermal spraying and surface coating technology, and the coating is prepared through the method that material increasing and patterning machining are alternated and comprises the following steps that patterns and intervals are designed; selecting the surface density and the volume ratio; spraying additive manufacturing and the like and a surface patterning machining technology are adopted for preparing the coating of the spatial three-dimensional network structure, and spraying and patterning machining are alternately carried out. The method has the advantages that the coating can obtain a three-dimensional network structure at the magnitude of several millimeters, so that the performance of a friction pair formed by the sealing component is greatly improved, and the surface of the sealing component has more beneficial tribological performance.

Description

Technical Field

[0001] The invention relates to the technical field of material surface modification and coating preparation, and particularly provides a sealing component with a surface coating having a three-dimensional network structure and a preparation method thereof. Background Art

[0002] Sealing components are widely used in the gas path sealing system of turbine engines and gas turbines, forming scrapable friction pairs with rotating parts such as blades, and using wear clearance to improve sealing efficiency. In order to improve sealing efficiency, the application of coating technology can greatly reduce friction consumption. Studies have shown that the application of scrapable sealing coatings on turbojet engines can reduce the gas path clearance of high-pressure turbine blade tips by 0.254mm and improve fuel efficiency by about 1%.

[0003] The surface of the commonly used sealing component is made of a bonding phase, a lubricating phase and a porous phase using thermal spraying technology: the bonding phase is generally similar to the metal matrix, providing the coating with bonding strength and resistance to erosion, oxidation and corrosion; the lubricating phase plays a role in facilitating shearing, reducing scraping resistance to reduce friction loss and avoid adhesion transfer, and reducing wear; the porous phase plays a role in adaptive deformation of the coating, interrupting and slowing down coating cracks, accommodating wear debris and controlling the transfer of the coating to the blade. Among them, the sealing coating of the sealing component ensures that the sealing groove is formed during high-speed scraping, and is compatible with the friction parts (such as blades) and has a friction-reducing effect, which is the technical key of the sealing coating. However, the thermal spraying preparation process determines its inevitable multi-layer deposition, the doping of the lubricating phase and the metal phase, and the unique structure of multiple pores, which leads to serious problems such as surface roughness and deterioration, severe deformation layer and shedding, coating surface densification, adhesion to blades, and local severe oxidation and block falling during actual use. Summary of the invention

[0004] The purpose of the present invention is to provide a sealing component with a three-dimensional network structure coating and a preparation technology thereof. The three-dimensional network structure is obtained by using a surface graphic processing technology in the process of depositing the coating layer by layer on the sealing component substrate, thereby solving the problems caused by the multi-layer, porous and multi-phase structure of the existing sealing coating, comprehensively regulating the intrinsic properties of the deposited material, and improving the performance of the sealing component.

[0005] It is used in the air path sealing system of aircraft engines and gas turbines, and can also be used for friction seals of hot end parts of gasoline and diesel engines, etc. Through surface graphic processing technology, a three-dimensional network structure coating is manufactured to obtain a sealing component with a multi-phase structure component interwoven on the surface.

[0006] A sealing component with a three-dimensional network structure surface coating comprises two parts: a substrate and a surface coating. The surface coating is a coating with a three-dimensional network structure. The three-dimensional spatial network structure of the coating is independent of the substrate and is combined with the substrate through thermal spraying and surface coating technology. The coating is prepared by alternating additive and patterning processing methods.

[0007] The total number of layers of the coating layer with the three-dimensional network structure is 2 to 20 layers.

[0008] The coating with the three-dimensional network structure, after additive and patterning processing such as spraying, the alternating odd-number coatings and even-number coatings each form a network structure that intersects in space.

[0009] The spatially intersecting network structure includes square, circular, rectangular and triangular patterns.

[0010] A method for preparing a sealing component having a surface coating with a three-dimensional network structure, wherein the three-dimensional network structure of the coating is independent of a substrate and is combined with the substrate through thermal spraying and surface coating techniques, and the coating is prepared by alternating additive and patterning processing methods;

[0011] The preparation method comprises the following steps:

[0012] The coating surface of the sealing component is modeled in three-dimensional network structure according to computer-aided design, and the coating deposition thickness is determined in combination with specific thermal spraying or other coating process parameters, and the side length and spacing of patterns including squares, circles, rectangles and triangles are designed, and the surface density and volume rate are selected;

[0013] Thermal spraying and surface patterning technology are used to prepare spatial three-dimensional network structure coatings. Thermal spraying processes include but are not limited to plasma spraying, supersonic flame spraying and explosion spraying; surface patterning processes include but are not limited to laser etching, electrolysis, and precision machining methods.

[0014] The total thickness of the three-dimensional network coating is related to the layer thickness of spraying or deposition, and the spatial structure parameters of the coating are designed based on the layer thickness, but are not limited to the layer thickness; the three-dimensional spatial network structure parameters of the coating are determined by computer-aided design and simulation calculation.

[0015] The specific technical process for obtaining the three-dimensional spatial network coating required by the design on the surface of the sealing component is to alternately carry out spraying and patterning processing, wherein spraying obtains the additive of the new surface, and patterning processing removes the material to prepare the new surface for subsequent spraying.

[0016] The surface spraying of sealing parts adopts thermal spraying or other coating processes as well as electrodeposition. The obtained surface coating material is designed according to the demand, and the composition of each spraying can be changed or adjusted.

[0017] Graphic processing uses mechanical, chemical or laser etching technology, and the characteristic parameters of each processing are selected based on three-dimensional network structure modeling.

[0018] Computer CAD-aided design is used to model the spatial three-dimensional network structure of the spray layer surface required for the sealing component. Combined with thermal spraying or other coating processes, the pattern data suitable for each deposition thickness is determined, including the side length and spacing of strips, squares, circles, rectangles and triangles, and the surface density and volume rate are selected, and the parameters of the number of spraying and thickness are made in the coating thickness direction.

[0019] Thermal spraying and surface patterning technology are used to prepare spatial three-dimensional network structure coatings. Thermal spraying processes include but are not limited to plasma spraying, supersonic flame spraying, explosion spraying, etc.; surface patterning processes include but are not limited to laser etching, electrolysis, precision machining, etc.

[0020] The specific technical process is to obtain the desired pattern on the surface of the sealing component substrate and alternately construct a three-dimensional network coating composed of two phases. Compared with the existing thermal spraying process, the specific process is as follows: Figure 1 As shown:

[0021] Performing graphic processing on the surface of the sealing component substrate;

[0022] Deposition of a single layer of coating on the patterned substrate surface requires that the composition and structural characteristics are similar to those of the substrate material, with good strength and bonding properties;

[0023] Graphic processing is performed on the single-layer coating to make the double-layer coating penetrate the three-dimensional space;

[0024] The coating is deposited in double layers, and its composition and organizational characteristics are mainly to provide tribological properties, with good friction and wear performance and interface bonding ability;

[0025] The coating is patterned again to form the first composite spatial three-dimensional structure of the odd and even number coatings;

[0026] According to the total coating thickness required by the design, multiple "spraying-patterning" composite forming processes are performed to form the final required surface patterned coating.

[0027] Beneficial effects of the present invention:

[0028] By alternating additive and graphic processing such as spraying, the coating can obtain a three-dimensional network structure at the millimeter level, greatly improving the performance of the friction pair of the sealing components. The deposition thickness of each thermal spraying is about tens of microns, and the surface patterning parameters optimized by laser etching or precision processing conditions are in the range of microns to several millimeters, and can be adjusted in a larger parameter range as needed. The properties of the three-dimensional structure coating, such as density, hardness, microstructure, roughness, etc., can be improved through process optimization and combining the metal phase and lubricating phase of the coating system required by different sealing components, so that the coating has the characteristics of low porosity and high interface bonding strength, so as to obtain more beneficial tribological properties for the surface of the sealing component. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a comparative block diagram of the spatial three-dimensional network coating preparation technology adopted by the present invention;

[0030] Figure 2 It is a typical process and parameter schematic diagram adopted by the present invention;

[0031] Figure 3 is a schematic diagram of the coating friction surface of a conventional sealing component;

[0032] Figure 4 It is a schematic diagram of the service characteristics of the spatial three-dimensional network coating sealing component obtained by the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0034] like Figure 2 As shown, a concave square pattern is first machined on the surface of the sealing component, and the spacing between them forms a network. Then a layer of anti-friction coating A with a composition of X is sprayed, and then a concave square pattern is machined, and the depth penetrates the anti-friction layer A, so that a network with a composition of X is obtained on the A coating. In this way, the next layer of coating B with a composition of Y is sprayed, and the composition Y is different from X to play other roles, and then patterning is performed on the B coating, and a new layer of a new network with a composition of Y is obtained after removing the concave square. Repeating the above process alternately, a three-dimensional spatial network coating with components X and Y cross-connected is obtained. The number of A and B coatings required depends on the total thickness of the target coating and the designed layer thickness of each spray.

[0035] In terms of specific spraying process methods, general technologies such as thermal spraying, cold spraying and electrodeposition can be selected. Patterning processing is also an existing general technology, which is not limited to mechanical processing, chemical or laser etching methods.

[0036] The specific spatial network used can be designed into square, rectangular, circular, triangular, etc.

[0037] In this embodiment, a titanium alloy base sealing ring in an aircraft engine gas path seal is taken as an example to prepare a nickel-graphite sealing coating for detailed description.

[0038] First, the structure design of the three-dimensional space network is carried out, with the side length L of the square pattern being 0.5 mm and the spacing a being 0.2 mm as the basic parameters. Figure 2 of grid.

[0039] Then, nickel graphite powder was selected as the friction-reducing coating A, and plasma thermal spraying technology was used, with a spraying layer thickness of 0.2 to 0.3 mm each time; nickel graphite powder with a trace amount of Cu added was selected as coating B, and plasma thermal spraying technology was still used, with a spraying layer thickness of 0.2 to 0.3 mm each time; each was sprayed 5 times to achieve a surface coating with a total thickness of 2.5 mm.

[0040] The surface of the component is patterned using a precision milling machine. The depth of each processing pit is 0.2-0.3mm, which is adapted to the thickness of the sprayed layer. The patterning process is performed alternately before and after each spraying. The last process is performed after the minimum spraying thickness is greater than 2.5mm, and the thickness is processed to 2.5mm to obtain a uniform outer surface.

[0041] like Figure 4 As shown, when the coating with the three-dimensional spatial network structure is scratched by the friction pair, the three-dimensional network of the scraped surface exhibits a different action mechanism compared to the single structure coating sprayed by multi-layer spraying, which is beneficial to reducing friction energy consumption and resistance, and improving the efficiency of the engine.

[0042] In the specific implementation process, according to the guiding ideology of the present invention, the spraying and patterning processing technologies that can be selected by technicians are all basic process methods, and their combination can achieve better technical and economic effects, which is also the scope of protection required by the patent of the present invention.

Claims

1. A sealing component having a three-dimensional network structure surface coating, characterized in that: The sealing component with a three-dimensional network structure surface coating comprises two parts: a substrate and a surface coating. The surface coating is a coating with a three-dimensional network structure. The three-dimensional spatial network structure of the coating is independent of the substrate and is combined with the substrate through thermal spraying and surface coating technology. The coating is prepared by alternating additive and patterning processing methods.

2. The sealing component having a three-dimensional network structure surface according to claim 1, characterized in that: The total number of layers of the coating layer with the three-dimensional network structure is 2 to 20 layers.

3. The sealing component having a three-dimensional network structure surface according to claim 1, characterized in that: The coating with the three-dimensional network structure, after spraying and patterning, the odd-number coatings and even-number coatings obtained alternately each form a network structure that intersects in space.

4. The sealing component having a three-dimensional network structure surface according to claim 3, characterized in that: The spatially intersecting network structure includes square, circular, rectangular and triangular patterns.

5. A method for preparing a sealing component having a surface coating with a three-dimensional network structure as claimed in claim 1, characterized in that: The three-dimensional network structure of the coating is independent of the substrate and is combined with the substrate through thermal spraying and surface coating techniques. The coating is prepared by alternating additive and patterning processing; The preparation method comprises the following steps: The coating surface of the sealing component is modeled in three-dimensional network structure according to computer-aided design, and the coating deposition thickness is determined in combination with specific thermal spraying or other coating process parameters, and the side length and spacing of patterns including squares, circles, rectangles and triangles are designed, and the surface density and volume rate are selected; Thermal spraying and surface patterning technology are used to prepare spatial three-dimensional network structure coatings. Thermal spraying processes include but are not limited to plasma spraying, supersonic flame spraying and explosion spraying; surface patterning processes include but are not limited to laser etching, electrolysis, and precision machining methods.

6. The method for preparing a sealing component having a surface coating with a three-dimensional network structure according to claim 5, characterized in that: The total thickness of the three-dimensional network coating is related to the layer thickness of the spraying or deposition, and the spatial structure parameters of the coating are designed based on the layer thickness, but are not limited to the layer thickness; The three-dimensional network structure parameters of the coating are determined by computer-aided design and simulation calculation.

7. The method for preparing a sealing component having a surface coating with a three-dimensional network structure according to claim 5, characterized in that: The specific technical process for obtaining the three-dimensional spatial network coating required by the design on the surface of the sealing component is to alternately carry out spraying and patterning processing, wherein spraying obtains the additive of the new surface, and patterning processing removes the material to prepare the new surface for subsequent spraying.

8. The method for preparing a sealing component having a surface coating with a three-dimensional network structure according to claim 5, characterized in that: The surface spraying of sealing parts adopts thermal spraying or other coating processes as well as electrodeposition. The obtained surface coating material is designed according to the demand, and the composition of each spraying can be changed or adjusted.

9. The method for preparing a sealing component having a surface coating with a three-dimensional network structure according to claim 5, characterized in that: Graphic processing uses mechanical, chemical or laser etching technology, and the characteristic parameters of each processing are selected based on three-dimensional network structure modeling.

Images