A method for preparing an anti-erosion coating, coating structure and components

Abstract

A method for preparing an anti-erosion coating is disclosed, comprising a gradient layer and a hard layer on a substrate surface. The method involves coating the substrate surface with a gradient layer and adjusting the H / E value of the gradient layer to create a gradient distribution along its thickness. This method improves the interlayer adhesion and mechanical property matching between the anti-erosion coating and the substrate, thereby enhancing the coating's performance and service life. The invention also provides an anti-erosion coating structure and component.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine coatings, specifically relating to a method for preparing an anti-erosion coating, the coating structure, and components. Background Technology

[0002] During their service life, aero-engines face complex and harsh operating conditions, such as environments containing impurities like sand, volcanic ash, smog, and rain. In these environments, solid particles carried by high-speed airflow can erode rotating and non-rotating components made of lightweight alloys, such as fans, compressors, and guide vanes, causing surface damage and severe performance degradation. This reduces engine safety, reliability, and maintainability, ultimately shortening its service life. Wind tunnel tests have shown that sand particles larger than 30 μm in diameter can cause significant erosion wear on blades, affecting the mechanical properties, overall structure, and aerodynamic stability of the bladed disk, and even posing a risk of fatigue failure. Erosion damage is one of the key factors leading to a significant decline in aero-engine performance and fatigue life.

[0003] Some existing engines employ hard coatings such as TiB2 on the surface of light alloy blades to achieve erosion resistance. To ensure a strong bond between the substrate and the coating, a gradient layer is often added for transition. However, the inventors recognized that considering only the hardness of the substrate and the hard layer during gradient layer application is insufficient to adequately coordinate the mechanical properties of different materials. Under conditions of mismatched stress and deformation, existing coatings are prone to cracking or peeling. Therefore, proposing a method for preparing an erosion-resistant coating with strong bonding and good stress / deformation coordination has significant application value. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing an erosion-resistant coating, thereby improving the interlayer adhesion and mechanical property matching between the coating and the substrate, and improving the performance and service life of the coating. This invention also provides an erosion-resistant coating structure and component.

[0005] According to one aspect of the present invention, a method for preparing an erosion-resistant coating is provided, for preparing a coating structure comprising a gradient layer and a hard layer on a substrate surface, the method comprising the following steps:

[0006] A gradient layer is coated on the surface of a substrate, and the H / E value of the gradient layer is adjusted to make it gradient-distributed in the thickness direction.

[0007] For composite coating structures that only consider the hardness of the hard layer and the substrate, when the elastic modulus E of the two differs significantly, the strain gradient at the interface under the same load will differ greatly, leading to interlayer strain mismatch and inducing cracks or spalling. By using specific hardness, i.e., the H / E value, as a control variable to design the mechanical property parameters of the gradient layer, the ability of different layers to resist plastic deformation under the same elastic deformation state under service conditions is comprehensively considered. This ensures that the stress-strain difference at the interface is small, preventing cracks and spalling caused by large strain gradient differences, improving coating performance, and extending coating life.

[0008] Furthermore, the substrate and the gradient layer are particulate-reinforced materials, wherein the H / E value is adjusted by controlling the volume or mass percentage of the reinforcing particles. By controlling the volume or mass percentage of the reinforcing particles, the change in H / E in the gradient layer can be accurately adjusted in a quantitative manner.

[0009] Furthermore, before coating the gradient layer, the method includes the following steps: preparing multiple test samples on the substrate, wherein the volume or mass fraction of the reinforcing particles in the test samples gradually increases; measuring and calculating the H / E value of each test sample, and calculating the volume or mass fraction of the reinforcing particles in the corresponding hard layer using interpolation. This allows for convenient control of the parameter variation range during the gradient coating process.

[0010] Furthermore, the coating method for the coating structure includes ion plating, PVD, or CVD. Ion plating, PVD, and CVD can effectively coat the coating while facilitating parameter control.

[0011] Furthermore, the values ​​of hardness H and elastic modulus E were obtained through nanoindentation testing. Nanoindentation testing is convenient and quick, requires a small sample size, and is suitable for testing the mechanical properties of coatings.

[0012] According to another aspect of the present invention, an erosion-resistant coating structure is provided, comprising a substrate, a gradient layer, and a hard layer, wherein the ratio of the hardness H to the elastic modulus E of the gradient layer, H / E, is distributed in a gradient direction along the thickness. This composite coating structure with a gradient H / E ratio harmonizes the interlayer stress / strain, improving the coating's performance and service life.

[0013] Furthermore, the H / E value of the bottom layer of the gradient layer is the same as that of the substrate, and the H / E value of the top layer of the gradient layer is the same as that of the hard layer. A continuous distribution of H / E values ​​at the interface can better improve interlayer stress / strain compatibility.

[0014] Furthermore, the thickness of the gradient layer in the coating is 1 / 5 to 1 / 3 of the thickness of the hard layer. This allows for thickness control without affecting the coating's functionality, thus reducing manufacturing costs.

[0015] Furthermore, the hard layer in the coating is a binary or multi-component coating. Binary or multi-component coatings can provide better protection.

[0016] Furthermore, the hard layer in the coating is multi-layered. The number of coating layers can be varied depending on the actual service environment.

[0017] Furthermore, the reinforcing particles include TiB2, SiC, Al2O3, or B4C. Hard particles made of metal or ceramic materials can effectively improve material properties.

[0018] According to another aspect of the present invention, an erosion-resistant component is provided, the surface of which includes a coating structure, wherein the coating structure is any of the aforementioned coating structures. The erosion-resistant coating structure can effectively improve the service life and performance of the component. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the coating structure in one embodiment;

[0020] Figure 2 A scanning electron microscope image of the coating structure in one embodiment;

[0021] Figure 3 This is a schematic diagram of the coating structure in another embodiment.

[0022] The purpose of the above figures is to provide a detailed description of the invention so that those skilled in the art can understand the technical concept of the invention, and not to limit the invention. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art; the terms used herein are intended only to describe particular embodiments and not to limit the scope of the invention; the terms “comprising” and “having” and their equivalents in the description, claims and foregoing drawings are intended to cover non-exclusive inclusion.

[0025] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment herein. The phrase appearing in various places in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive, independent, or alternative embodiments. Those skilled in the art will understand that the embodiments herein can be combined with other embodiments without causing structural conflicts.

[0026] In this description, terms such as “upper,” “lower,” “surface,” and “bottom” that indicate orientation or positional relationship are intended to accurately describe the embodiments and simplify the description, rather than limiting the parts or structures involved to have a specific orientation, or to be installed or operated in a specific orientation, and should not be construed as limiting the embodiments in this document.

[0027] According to an embodiment of the present invention, a method for preparing an erosion-resistant coating is provided, wherein the prepared coating structure is as follows: Figure 1 As shown, a coating structure comprising a gradient layer 2 and binary hard layers 31 and 32 is prepared on the surface of substrate 1. Substrate 1 is a 2024 aluminum alloy containing 5 wt.% TiB2 reinforcing particles, and the target hard layer is a TiAlN / Ti multilayer binary hard coating. The coating is applied using an ion plating process. The method includes the following steps:

[0028] a-1) Two 20mm × 15mm × 3mm substrate and hard coating samples were prepared, with a coating thickness of 10μm and a total of 16 layers. Nanoindentation testing revealed a substrate hardness of H = 0.918 GPa and an elastic modulus of E = 86.4 GPa, resulting in an H / E ratio of 0.010625. The hard coating hardness was H = 11.85 GPa and an elastic modulus of E = 115.7 GPa, resulting in an H / E ratio of 0.10242. This determined the H / E ranges for the bottom and top layers of the gradient layer.

[0029] a-2) Test samples with different TiB2 contents were prepared on 2024 alloy using ion plating. The content of reinforcing particles in the samples increased in a 5 wt.% gradient, and the sample thickness was controlled between 2 and 3 μm. The ion plating process parameters were controlled as follows: arc current 60 A, duty cycle 10%, and deposition time 60 min. Using linear interpolation, the substrate bias voltage for the ion plating deposition process corresponding to the sample with a specific hardness H / E = 0.010625 was calculated to be -34.5 V, and the substrate bias voltage corresponding to the sample with a specific hardness H / E = 0.10242 was -98.7 V.

[0030] b) A gradient layer is coated on the substrate surface, such that the H / E value at the bottom layer (i.e., the interface between the gradient layer and the substrate) is the same as that of the substrate. The H / E value of the gradient layer is adjusted to form a gradient distribution in the thickness direction. Preferably, the H / E value at the surface layer (i.e., the interface between the gradient layer and the hard layer) is the same as that of the target hard layer. It can be understood that "same" here means within the error range of microhardness testing and calculation or within a difference of 10%, not that the exponential values ​​are completely equal. Specifically, based on the process parameters in step a-2), the substrate bias voltage is controlled to change in a gradient from -34.5V to -98.7V to deposit TiB2 target material, obtaining a gradient layer with a thickness of approximately 2.121μm. The specific hardness of the bottom layer is H / E = 0.010625, and the specific hardness of the surface layer is H / E = 0.10242.

[0031] c) Continue to use ion plating to prepare a multilayer TiAlN / Ti hard coating with a total coating thickness of 10 μm. The process parameters for Ti layer 31 are 0.25 μm / 2.5 min, arc current 70 A, bias voltage -200 V, and duty cycle 20%; the process parameters for TiAlN layer 32 are 0.71 μm / 10 min, arc current 60 A, bias voltage 0 V, nitrogen partial pressure 1.5 Pa, and duty cycle 10%; the vacuum chamber temperature during deposition is 120℃-140℃.

[0032] The coating obtained by the above method is shown in a scanning electron microscope image as follows. Figure 2 As shown, the hard layers consisting of Ti and TiAlN hard layers adhere well to the TiB2 / Al gradient layer. The bright Ti layer is tightly bonded to the darker TiB2 / Al gradient layer without gaps or pores. The multi-layered Ti / TiAlN repeating layers eliminate the occasional protrusions that occurred during the coating process of the underlying hard layer, and its upper surface is basically flat.

[0033] According to another embodiment of the present invention, a method for preparing an erosion-resistant coating is provided, wherein the prepared coating structure is as follows: Figure 3 As shown, a coating structure comprising a gradient layer 2 and a hard layer 3 is prepared on the surface of a substrate 1. The substrate 1 is a 2024 aluminum alloy containing 5 wt.% TiB2 reinforcing particles. The target hard layer is a TiAlN / Ti binary hard coating 31 and 32 with a total of two layers, and the coating is applied using an ion plating process. The method includes the following steps:

[0034] a-1) Prepare 20mm × 15mm × 3mm substrate and hard coating samples, with a coating thickness of 10μm. Nanoindentation testing yielded a substrate hardness H = 0.918 GPa and an elastic modulus E = 86.4 GPa, resulting in an H / E ratio of 0.010625. The hard coating hardness H = 12.195 GPa and an elastic modulus E = 123.6 GPa, resulting in an H / E ratio of 0.095665. This determines the H / E range for the bottom and top layers of the gradient layer.

[0035] a-2) Test samples with different TiB2 contents were prepared on 2024 alloy using ion plating. The content of reinforcing particles in the samples increased in a 5 wt.% gradient, and the sample thickness was controlled between 2 and 3 μm. The ion plating process parameters were controlled as follows: arc current 60 A, duty cycle 10%, and deposition time 60 min. Using Kriging interpolation, the substrate bias voltage for the ion plating deposition process corresponding to the sample with a specific hardness H / E = 0.010625 was calculated to be -34.5 V, and the substrate bias voltage corresponding to the sample with a specific hardness H / E = 0.095665 was -93.7 V.

[0036] (b) A gradient layer is coated on the substrate surface, ensuring that the H / E value of the bottom layer of the gradient layer is the same as that of the substrate. The H / E value of the gradient layer is adjusted to form a gradient distribution in the thickness direction, so that the H / E value of the surface layer is the same as that of the target hard layer. It can be understood that "same" here means within the error range of microhardness testing and calculation, or within a 10% difference, not that the exponential values ​​are completely equal. Specifically, based on the process parameters in step (a-2), the substrate bias voltage is controlled to gradually change from -34.5V to -93.7V to deposit TiB2 target material, obtaining a gradient layer with a thickness of approximately 2.121 μm. The specific hardness of the bottom layer is H / E = 0.010625, and the specific hardness of the surface layer is H / E = 0.095665.

[0037] c) Continue to use ion plating to prepare a multilayer TiAlN / Ti hard coating with a total coating thickness of 10 μm. The process parameters for Ti layer 31 are 1.69 μm / 14 min, arc current 70 A, bias voltage -200 V, and duty cycle 20%; the process parameters for TiAlN layer 32 are 4.44 μm / 55 min, arc current 60 A, bias voltage 0 V, nitrogen partial pressure 1.5 Pa, and duty cycle 10%; the vacuum chamber temperature during deposition is 120℃-140℃.

[0038] In some other embodiments, the H / E value of the gradient layer can also be adjusted by adjusting the composition of the alloy components or phases; the coating can also be applied by physical vapor deposition (PVD) or chemical vapor deposition (CVD); the hardness and elastic modulus of some substrates and coatings can be obtained by consulting industrial handbooks or other testing methods.

[0039] In some other embodiments, the thickness of the gradient layer is 1 / 5 to 1 / 3 of the thickness of the hard layer; the hard layer can be a mono-, binary, or multi-component coating of materials such as TiB2 or other hard ceramic materials, and can be a single-layer or multi-layer structure; the reinforcing particles in the substrate and the gradient layer can also be SiC, Al2O3, or B4C, etc.

[0040] According to another embodiment of the present invention, an erosion-resistant component is provided, the surface of which has a coating structure, which is the coating structure of any of the above embodiments. The component may include rotating parts in an aero-engine, such as compressor or fan blades, or non-rotating parts in an aero-engine, such as stator blades. The component with this erosion-resistant coating has good resistance to the erosion caused by solid particles in the environment. The coating is strong, has a long service life, and is not prone to cracking or peeling, enabling the component to maintain stable performance for a long time under harsh operating conditions, thereby improving the safety, reliability, and maintainability of the engine.

[0041] It should be understood that the purpose of the above embodiments is to provide a detailed description of the technical solutions of the present invention in conjunction with the accompanying drawings, so that those skilled in the art can understand the technical concept of the present invention, and not to limit the present invention. Within the scope of the claims, optimization or equivalent substitution of the parts, structures or method steps involved in the various embodiments, as well as combinations of different embodiments without structural changes and without conflict, all fall within the protection scope of the present invention.

Claims

1. A method for preparing an erosion-resistant coating, used to prepare a coating comprising a gradient layer and a hard layer on a substrate surface, characterized in that, Includes the following steps: Multiple test samples are prepared on the substrate, and the volume or mass fraction of reinforcing particles in the test samples gradually increases; the H / E value of each test sample is measured and calculated, and the volume or mass fraction of reinforcing particles in the corresponding hard layer is calculated by interpolation. A gradient layer is coated on the surface of a substrate, and the H / E value of the gradient layer is adjusted to make it gradient-distributed in the thickness direction. The method of adjusting the H / E value is to control the volume or mass percentage of the reinforcing particles so that the H / E value of the bottom layer of the gradient layer is the same as that of the substrate, and the H / E value of the top layer of the gradient layer is the same as that of the hard layer.

2. The method for preparing the anti-erosion coating according to claim 1, characterized in that, The coating method includes ion plating, PVD, or CVD.

3. The method for preparing the anti-erosion coating according to claim 1, characterized in that, The values ​​of hardness H and elastic modulus E were obtained through nanoindentation testing.

4. An erosion-resistant coating structure, comprising a substrate, a gradient layer, and a hard layer, characterized in that, The gradient layer includes reinforcing particles with different volume or mass percentages in the thickness direction, so that the ratio of the hardness H to the elastic modulus E of the gradient layer, H / E, is distributed in a gradient direction in the thickness direction; the H / E value of the bottom layer of the gradient layer is the same as that of the substrate, and the H / E value of the top layer of the gradient layer is the same as that of the hard layer.

5. The erosion-resistant coating structure according to claim 4, characterized in that, The thickness of the gradient layer is 1 / 5 to 1 / 3 of the thickness of the hard layer.

6. The erosion-resistant coating structure according to claim 4, characterized in that, The hard layer is a binary or multi-element coating.

7. The erosion-resistant coating structure according to claim 4, characterized in that, The hard layer consists of multiple layers.

8. The erosion-resistant coating structure according to claim 4, characterized in that, The reinforcing particles include TiB2, SiC, Al2O3, or B4C.

9. An erosion-resistant component, the surface of which includes a coating structure, characterized in that, The coating structure is the coating structure described in any one of claims 4 to 8.

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