Sealing component with three-dimensional network structure surface coating

Abstract

According to the sealing component with the three-dimensional network structure surface coating, the surface coating comprises the base body and the surface coating, the surface coating is of the three-dimensional network structure, the three-dimensional space network structure of the coating is independent of the base body, the coating is combined with the base body through the thermal spraying and surface coating technology, and therefore the surface coating is formed. The coating is prepared by a method of alternating additive processing and patterning processing. The sealing component 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] This utility model relates to the field of material surface modification and coating preparation technology, and specifically provides a sealing component with a surface coating having a three-dimensional network structure. Background Technology

[0002] Sealing components are widely used in the gas path sealing systems of turbine engines and gas turbines, forming a scrapable friction pair with rotating blade components to improve sealing efficiency by utilizing wear clearances. To further improve sealing efficiency, coating technology can significantly reduce friction loss. Studies have shown that applying scrapable sealing coatings to turbojet engines can reduce the high-pressure turbine tip gas path clearance by 0.254 mm, improving fuel efficiency by approximately 1%.

[0003] The surface of commonly used sealing components that perform sealing functions is coated using thermal spraying technology to create a structure consisting of a binder phase, a lubricating phase, and a porous phase. The binder phase is generally similar to the metal substrate, providing the coating with bonding strength and resistance to erosion, oxidation, and corrosion. The lubricating phase facilitates shearing, reduces scraping resistance to lower frictional loss, prevents adhesion transfer, and reduces wear. The porous phase allows the coating to adapt to deformation, interrupts and slows down coating cracking, and accommodates wear debris to control coating transfer to the blades. The key technical aspect of sealing coatings is ensuring that, while maintaining sufficient mechanical strength for sealing and resistance to erosion and wear, the sealing coating forms a sealing groove during high-speed scraping, is compatible with the contacting components (such as blades), and provides a friction-reducing effect. However, the thermal spraying process inevitably involves multi-layer deposition, doping of the lubricating and metallic phases, and a unique porous structure. This leads to problems in actual use, such as surface roughness and degradation, severe deformation and peeling, coating surface densification, adhesion to blades, and severe localized oxidation and spalling. Utility Model Content

[0004] The purpose of this invention is to provide a sealing component with a three-dimensional network structure coating. By using surface patterning processing technology during the deposition of coatings layer by layer on the substrate of the sealing component, a three-dimensional network structure is obtained, which solves the problems caused by the multi-layer, porous and multi-phase structure of existing sealing coatings. The intrinsic properties of the deposited material are comprehensively controlled to improve the performance of the sealing component.

[0005] It is used in gas path sealing systems for aero engines and gas turbines, and can also be applied to friction seals for hot-end components of gasoline and diesel engines. A three-dimensional network structure coating is manufactured using surface patterning processes to obtain sealing components with a multiphase interwoven coating on the surface.

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

[0007] The coating of the three-dimensional network structure has a total of 2 to 20 layers.

[0008] The three-dimensional network structure coating, after being sprayed and patterned, alternately forms a spatially intersecting network structure with odd-numbered coatings and even-numbered coatings.

[0009] The spatially intersecting network structure includes patterns of squares, circles, rectangles, and triangles.

[0010] 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 techniques. The coating is prepared by alternating additive and patterning processes.

[0011] Based on computer-aided design, a three-dimensional network structure model is created for the coating surface of the sealing component. The coating deposition thickness is determined in combination with specific thermal spraying or other coating process parameters. Patterns including squares, circles, rectangles and triangles are designed with side lengths and spacing, and areal density and volume fraction are selected.

[0012] A three-dimensional network structure coating is prepared using thermal spraying and surface patterning techniques. Thermal spraying processes include, but are not limited to, ion spraying, supersonic flame spraying, and detonation spraying; surface patterning processes include, but are not limited to, laser etching, electrolysis, and precision machining.

[0013] The specific technical process for obtaining the required three-dimensional spatial network coating on the surface of a sealing component involves alternating spraying and patterning processes. Spraying creates an additive material on the new surface, while patterning removes material to prepare a new surface for subsequent spraying.

[0014] The surface coating of the sealing components is applied using thermal spraying or other coating processes as well as electrodeposition. The resulting surface coating material is designed according to the requirements, and the composition can be changed or adjusted for each spray.

[0015] Computer-aided design (CAD) is used to create a three-dimensional network structure model of the surface of the sealing component to be coated. Combined with thermal spraying or other coating processes, the appropriate pattern data for each deposition thickness is determined, including the side length and spacing of stripes, squares, circles, rectangles and triangles. The areal density and volume fraction are selected, and parameters for the number of sprays and the thickness are determined in the coating thickness direction.

[0016] The preparation of spatial three-dimensional network structure coatings is carried out using additive manufacturing processes such as spraying and surface patterning. Spraying processes include, but are not limited to, plasma spraying, supersonic flame spraying, and explosive spraying; surface patterning processes include, but are not limited to, laser etching, electrolysis, and precision machining.

[0017] The beneficial effects of this utility model are:

[0018] By alternating between spraying and patterning, a three-dimensional network structure can be achieved in the coating on the order of millimeters, significantly improving the performance of the friction pairs in sealing components. Each deposition in thermal spraying is approximately tens of micrometers thick, and the surface patterning parameters, optimized under laser etching or precision machining conditions, range from micrometers to millimeters, and can be adjusted within a wider range as needed. The properties of the three-dimensional structure coating, such as density, hardness, microstructure, and roughness, can be improved through process optimization, combined with the metallic and lubricating phases required by different sealing components in the coating system. This results in coatings with low porosity and high interfacial bonding strength, providing the sealing component surface with more beneficial tribological properties. Attached Figure Description

[0019] Figure 1 It is a schematic diagram of the typical process and parameters used;

[0020] Figure 2 This is a schematic diagram of the friction surface of a traditional sealing component;

[0021] Figure 3 This is a schematic diagram illustrating the service characteristics of the spatial three-dimensional network coating sealing component obtained by this utility model. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0023] like Figure 1 As shown, concave square patterns are first machined onto the surface of the sealing component, with spacing forming a network. Then, a friction-reducing coating A of composition X is sprayed on. The concave square patterns are then machined again, penetrating the friction-reducing layer A, thus creating a network of composition X on coating A. In this manner, a next coating B of composition Y is sprayed on. Composition Y differs from X to perform other functions. Then, patterning is performed on coating B, and the concave squares are removed to obtain a new network of composition Y. This process is repeated alternately to obtain a three-dimensional spatial network coating with interconnected components X and Y. The required number of A and B coating layers depends on the total thickness of the target coating and the designed layer thickness for each spray.

[0024] In terms of specific spraying processes, thermal spraying, cold spraying, and electrodeposition techniques can be selected. Patterning is also an existing general technique and is not limited to mechanical processing, chemical etching, or laser etching methods.

[0025] The specific spatial network used can be designed as a square, rectangle, circle, or triangle.

[0026] In this embodiment, a nickel-graphite sealing coating is prepared in detail, taking a titanium alloy substrate sealing ring in the gas path sealing of an aero-engine as an example.

[0027] First, the structure of the three-dimensional spatial network is designed, with the basic parameters being a square pattern side length L of 0.5mm and a spacing a of 0.2mm, and a grid as shown in Figure 1 is designed.

[0028] Then, nickel graphite powder was selected as the anti-friction coating A, and plasma thermal spraying technology was used to spray a coating thickness of 0.2-0.3 mm each time; nickel graphite powder with trace amounts of Cu was selected as the coating B, and plasma thermal spraying technology was used again to spray a coating thickness of 0.2-0.3 mm each time; each coating was sprayed 5 times to achieve a surface coating with a total thickness of 2.5 mm.

[0029] A precision engraving and milling machine is used to pattern the surface of the parts. The depth of each patterned pit is 0.2 to 0.3 mm, which is adapted to the thickness of the spray coating. Patterning is performed alternately before and after each spray coating. The final processing is performed after the minimum spray coating thickness is greater than 2.5 mm, and is then processed to 2.5 mm to obtain a uniform outer surface.

[0030] like Figure 3 As shown, when the coating with the obtained three-dimensional spatial network structure is scraped by the friction pair, compared with the single-structure coating with multi-layer spraying, the three-dimensional network on the scraped surface exhibits a different mechanism of action, which is beneficial to reduce friction energy consumption and drag, and improve engine efficiency.

[0031] In the specific implementation process, based on the guiding principles of this utility model, the spraying and patterning techniques that technicians can choose are both basic process methods, and their combination can achieve better technical and economic results. This also falls within the scope of protection sought by this utility model patent.

Claims

1. A sealing member having a three-dimensional network structured surface coating, characterized by: The sealing part with the three-dimensional network structure surface coating comprises a base and a surface coating, the surface coating is a three-dimensional network structure coating, the three-dimensional space network structure of the coating is independent of the base, the coating is combined with the base through thermal spraying and surface coating technology, and the coating is prepared by alternately adopting additive and patterning processing.

2. The sealed component having a three-dimensional network structured surface coating of claim 1, wherein: The three-dimensional network structure coating has a total layer number of 2 to 20.

3. The sealed component having a three-dimensional network structured surface coating of claim 1, wherein: After spraying and patterning processing, the single-numbered coating and the double-numbered coating alternately obtained form a space intersecting network structure respectively.

4. The sealed component having a three-dimensional network structured surface coating of claim 3, wherein: The space intersecting network structure comprises square, circular, rectangular and triangular patterns.

Images