Platinum aluminum coating and preparation method thereof, and engine

Abstract

The present invention provides a platinum-aluminum coating, a preparation method thereof, and an engine. The platinum-aluminum coating comprises a first sub-coating and a second sub-coating, which are sequentially stacked on a substrate. The first sub-coating comprises a platinum-containing γ+γ' phase material, and the second sub-coating comprises a platinum-containing β phase material. The aluminum content in the first sub-coating is lower than that in the second sub-coating. The first sub-coating is positioned between the second sub-coating and the substrate, preventing the second sub-coating (high in aluminum) from direct contact with the substrate. The lower aluminum content in the first sub-coating makes interdiffusion with the substrate less likely.

Description

Technical Field

[0001] The present invention relates to the field of film coating technology, and in particular to a platinum-aluminum coating, a preparation method thereof, and an engine. Background Art

[0002] As the thrust-to-weight ratio of aircraft engines continues to increase, the temperature of the gas before the turbine has reached 2000°C. However, the melting point of current high-temperature resistant alloys is generally around 1200°C, making it difficult for them to directly withstand these temperatures. Thermal barrier coatings provide excellent thermal insulation, allowing the high-temperature resistant alloy substrate to withstand even higher temperatures.

[0003] Thermal barrier coatings typically consist of a surface ceramic layer and a bonding layer. The bonding layer material typically needs to meet the following two conditions: First, the bonding layer material must be able to rapidly generate a continuous, dense oxide film to provide an antioxidant effect; second, the resulting oxide film must have good interfacial bonding with the bonding layer. β-phase platinum-aluminum alloys can better meet these conditions and are therefore often used as bonding layer materials. However, traditional β-phase platinum-aluminum alloys are prone to interdiffusion with the substrate material during operation, resulting in a significant reduction in the mechanical properties of the substrate material. Summary of the Invention

[0004] Based on this, it is necessary to address the problems in the above background technology and provide a method for preparing a platinum-aluminum coating that can meet the requirements of the bonding layer while not easily interdiffusion with the base material.

[0005] According to some embodiments of the present invention, a platinum-aluminum coating is provided, which includes a first sub-coating and a second sub-coating, wherein the first sub-coating and the second sub-coating are sequentially stacked on a substrate, the first sub-coating includes a platinum-containing γ+γ' phase material, the second sub-coating includes a platinum-containing β phase material, and the aluminum content in the first sub-coating is lower than the aluminum content in the second sub-coating.

[0006] In some embodiments of the present invention, the atomic weight proportion of aluminum in the first sub-coating layer is less than 25%.

[0007] In some embodiments of the present invention, the atomic weight of aluminum in the second sub-coating layer accounts for 30% to 60%.

[0008] In some embodiments of the present invention, the thickness of the first sub-coating layer is 5 μm to 30 μm.

[0009] In some embodiments of the present invention, the thickness of the second sub-coating layer is 10 μm to 50 μm.

[0010] Furthermore, the present invention also provides a method for preparing the platinum-aluminum coating as described in the above embodiment, which comprises the following steps:

[0011] Preparing a platinum metal layer on a substrate, and preparing a platinum-containing alloy material layer based on the platinum metal layer, wherein the alloy material layer includes a γ-phase material;

[0012] The alloy material layer is subjected to an aluminizing treatment so that the top portion of the alloy material layer is converted into a β-phase material to form the second sub-coating, and at least the portion of the alloy material layer below the second sub-coating is converted into a γ+γ' phase material to form the first sub-coating.

[0013] In some embodiments of the present invention, the step of performing aluminizing treatment on the alloy material layer includes: performing vapor phase aluminizing treatment on the alloy material layer to convert part of the alloy material layer into β-phase material, and during the vapor phase aluminizing treatment, the aluminizing agent includes a catalyst and an aluminizing source, the catalyst includes one or more of ammonium bifluoride and ammonium bichloride, and the aluminizing source is selected from one or more of nickel-aluminum alloy and iron-aluminum alloy.

[0014] In some embodiments of the present invention, in the aluminizing agent, the mass proportion of the aluminizing source is 95% to 99%; and / or,

[0015] The mass proportion of the catalyst is 1% to 3%.

[0016] In some embodiments of the present invention, during the vapor phase aluminizing process, the aluminizing temperature is controlled to be 850° C. to 1200° C.

[0017] In some embodiments of the present invention, the thickness of the platinum metal layer is 2 μm to 10 μm.

[0018] In some embodiments of the present invention, the substrate includes nickel elements, and the steps of preparing a platinum-containing alloy material layer based on the platinum metal layer include: placing the substrate in a vacuum environment, heating the platinum metal layer and controlling the temperature of the platinum metal layer to 900°C~1150°C, so that the platinum metal layer is combined with the nickel element in the substrate to form the alloy material layer.

[0019] Furthermore, the present invention also provides an engine, which includes an engine substrate and the platinum-aluminum coating as described in the above embodiment, wherein the first sub-coating and the second sub-coating in the platinum-aluminum coating are sequentially stacked on the engine substrate.

[0020] To meet the requirements for strong oxidation resistance and interfacial bonding, conventional technologies typically use a β-phase platinum-aluminum alloy as the bonding layer. However, the high aluminum content in β-phase platinum-aluminum alloys can easily lead to interdiffusion with the base material, resulting in a gradual degradation of the base material's mechanical properties over long-term use.

[0021] The platinum-aluminum coating of the present invention includes a first sub-coating and a second sub-coating, which are sequentially stacked on a substrate. The first sub-coating includes a platinum-containing γ+γ' phase material, and the second sub-coating includes a platinum-containing β phase material. The aluminum content in the first sub-coating is lower than that in the second sub-coating. In the platinum-aluminum coating, the second sub-coating away from the substrate includes a platinum-containing β phase material, which has a high aluminum content and can meet the requirement of rapidly generating an oxide film. The first sub-coating close to the substrate includes a platinum-containing γ+γ' phase material, which can stably combine with the substrate and the β phase in the second sub-coating, meeting the interface bonding force requirement. In addition, the first sub-coating is located between the second sub-coating and the substrate, avoiding direct contact between the second sub-coating with a high aluminum content and the substrate. The first sub-coating has a low aluminum content and is less prone to interdiffusion with the substrate.

[0022] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, without paying any creative work, they can also obtain drawings of other embodiments based on these drawings.

[0024] Figure 1 Schematic diagram of the structure of a platinum-aluminum coating of the present invention;

[0025] Figure 2 Schematic diagram of the steps of a method for preparing a platinum-aluminum coating;

[0026] Figure 3 Schematic diagram of the cross-sectional structure of the coating prepared in Example 1;

[0027] Figure 4 This is a schematic diagram of the cross-sectional structure of the coating prepared in Example 2;

[0028] Figure 5 Schematic diagram of the cross-sectional structure of the coating prepared in Comparative Example 1;

[0029] Figure 6 Schematic diagram of the cross-sectional structure of the coating prepared in Comparative Example 2;

[0030] The reference numerals and their meanings are as follows:

[0031] 110. Substrate; 120. First sub-coating layer; 130. Second sub-coating layer. DETAILED DESCRIPTION

[0032] To facilitate understanding of this document, a more comprehensive description of this document is provided below. Preferred embodiments of this document are provided herein. However, this document can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present document.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this document pertains. The terms used herein in the specification are for the purpose of describing specific embodiments only and are not intended to limit this document.

[0034] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent to, connected to, or coupled to the other element or layer, or there can be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there can be no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion.

[0035] Spatially relative terms such as "under," "beneath," "beneath," "under," "over," "above," and the like, may be used herein for convenience of description to describe the relationship of one element or feature to other elements or features. It should be understood that the spatially relative terms are intended to also encompass different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, then elements or features described as "under" or "beneath" or "beneath" the other elements would be oriented "over" the other elements or features. Thus, the exemplary terms "under" and "under" may encompass both the above and below orientations. The device may be otherwise oriented (e.g., rotated 90 degrees or in other orientations) and the spatial descriptors used interpreted accordingly.

[0036] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present disclosure. When used herein, the singular forms "a," "an," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "including," when used in this specification, identify the presence of features, integers, steps, operations, elements, and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0037] The present invention provides a platinum-aluminum coating, which includes a first sub-coating and a second sub-coating. The first sub-coating and the second sub-coating are sequentially stacked on a substrate. The first sub-coating includes a platinum-containing γ+γ' phase material, and the second sub-coating includes a platinum-containing β phase material. The aluminum content in the first sub-coating is lower than the aluminum content in the second sub-coating.

[0038] To meet the requirements for strong oxidation resistance and interfacial bonding, conventional technologies typically use a β-phase platinum-aluminum alloy as the bonding layer. However, the high aluminum content in β-phase platinum-aluminum alloys can easily lead to interdiffusion with the base material, resulting in a gradual degradation of the base material's mechanical properties over long-term use.

[0039] The platinum-aluminum coating of the present invention includes a first sub-coating and a second sub-coating, which are sequentially stacked on a substrate. The first sub-coating includes a platinum-containing γ+γ' phase material, and the second sub-coating includes a platinum-containing β phase material. The aluminum content in the first sub-coating is lower than that in the second sub-coating. In the platinum-aluminum coating, the second sub-coating away from the substrate includes a platinum-containing β phase material, which has a high aluminum content and can meet the requirement of rapidly generating an oxide film. The first sub-coating close to the substrate includes a platinum-containing γ+γ' phase material, which can stably combine with the substrate and the β phase in the second sub-coating, meeting the interface bonding force requirement. In addition, the first sub-coating is located between the second sub-coating and the substrate, avoiding direct contact between the second sub-coating with a high aluminum content and the substrate. The first sub-coating has a low aluminum content and is less prone to interdiffusion with the substrate.

[0040] Figure 1 This is a schematic structural diagram of a platinum aluminum coating of the present invention. Figure 1 As shown, the platinum-aluminum coating includes a first sub-coating 120 and a second sub-coating 130, which are sequentially stacked on a substrate 110. The first sub-coating 120 includes a γ+γ' phase material containing platinum, and the second sub-coating 130 includes a β phase material containing platinum. The aluminum content in the first sub-coating 120 is lower than that in the second sub-coating 130.

[0041] In the first sub-coating layer 120, the γ+γ' phase material refers to a eutectic material composed of γ and γ' phases. The γ phase material may include platinum and nickel and may be represented as γ(Ni, Pt). The γ' phase material may include platinum, nickel, and aluminum and may be represented as γ'(Ni, Pt)3Al. The β phase material may also include platinum, nickel, and aluminum and may be represented as β(Ni, Pt)Al. The aluminum content in the β phase material is higher than that in the γ+γ' phase material.

[0042] Although there are some technologies that mention the use of γ' phase materials as bonding layers to improve the interdiffusion problem as much as possible, it is difficult for γ' phase materials to quickly generate dense oxide films, and it is also difficult to maintain a single oxide film for a long time. The platinum aluminum coating of the present invention sets a γ+γ' phase material as the first sub-coating 120, and further sets a β phase material as the second sub-coating 130 on the first sub-coating 120. The second sub-coating located above contains the β phase material, which can effectively improve the overall oxidation resistance of the platinum aluminum coating. The first sub-coating of the γ+γ' phase located below can effectively improve the compatibility between the coating and the substrate, and improve or even avoid the problem of interdiffusion between the β phase material and the base substrate 110. Therefore, the platinum aluminum coating can take into account the anti-oxidation effect while making it less likely for the platinum aluminum coating and the substrate 110 to have interdiffusion problems.

[0043] In this embodiment, the substrate 110 may be a high-temperature alloy. A high-temperature alloy refers to a metal material that can withstand certain stresses and maintain normal operation at temperatures above 600° C. In some examples of this embodiment, the substrate 110 may include nickel.

[0044] In some examples of this embodiment, the first sub-coating layer 120 may be composed of a γ+γ′ phase material, and the second sub-coating layer 130 may be composed of a β phase material.

[0045] In some examples of this embodiment, the molar ratio of aluminum in the first sub-coating 120 is less than 25%. The molar ratio can also be understood as an atomic ratio, i.e., the ratio of the total number of aluminum atoms to all atoms in the first sub-coating 120. It is understood that the first sub-coating 120 contains γ+γ' phase material.

[0046] In some examples of this embodiment, the content of aluminum in the first sub-coating 120 may be 10% to 25%. For example, the content of aluminum in the first sub-coating 120 may be 10%, 12%, 14%, 15%, 16%, 18%, 20%, 22%, 24%, or 25%. Alternatively, the content of aluminum in the first sub-coating 120 may be between any two of the above content ratios. Controlling the content of aluminum in the first sub-coating 120 to be between 5% and 19% helps to minimize interdiffusion issues while ensuring strong bonding between the first sub-coating 120 and the second sub-coating 130.

[0047] In some examples of this embodiment, the amount of aluminum in the second sub-coating layer 130 is 30% to 60%. For example, the amount of aluminum in the second sub-coating layer 130 may be 30%, 35%, 37%, 40%, 42%, 45%, 47%, 50%, 52%, 55%, 57%, or 60%. Alternatively, the amount of aluminum in the second sub-coating layer 130 may be between any two of the above amount ratios.

[0048] In some examples of this embodiment, the thickness of the first sub-coating layer 120 is 5 μm to 30 μm. Controlling the thickness of the first sub-coating layer 120 to be between 5 μm and 30 μm can effectively alleviate the interdiffusion problem and ensure high compatibility between the entire platinum-aluminum coating and the substrate 110.

[0049] In some examples of this embodiment, the thickness of the first sub-coating layer 120 is 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, or 30 μm. Alternatively, the thickness of the first sub-coating layer 120 may be within a range between any two of the above thicknesses.

[0050] It is understood that, due to the actual manufacturing process, the thickness of the first sub-coating 120 may not be completely uniform, and may have thinner areas and thicker areas. The thickness of the first sub-coating 120 here refers to the average thickness of the first sub-coating 120.

[0051] In some examples of this embodiment, the thickness of the second sub-coating layer 130 is 10 μm to 50 μm. Controlling the thickness of the second sub-coating layer 130 to be between 10 μm and 50 μm can ensure that the platinum-aluminum coating layer has a good anti-oxidation effect.

[0052] In some examples of this embodiment, the thickness of the second sub-coating 130 is 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm, or the thickness of the second sub-coating 130 can also be in a range between any two of the above thicknesses.

[0053] It is understood that, due to the actual manufacturing process, the thickness of the second sub-coating 130 may not be completely uniform, and may have thinner areas and thicker areas. The thickness of the second sub-coating 130 here refers to the average thickness of the second sub-coating 130.

[0054] Furthermore, the present invention also provides a method for preparing the above-mentioned platinum-aluminum coating. Figure 2 Schematic diagram of the steps of a method for preparing a platinum aluminum coating. Figure 2 As shown, the preparation method of the platinum-aluminum coating includes steps S1 to S3.

[0055] Step S1 : preparing a platinum metal layer on the substrate 110 .

[0056] In this embodiment, the substrate 110 may be a high-temperature alloy. A high-temperature alloy refers to a metal material that can withstand certain stresses and maintain normal operation at temperatures above 600° C. In some examples of this embodiment, the substrate 110 may include nickel.

[0057] In some examples of this embodiment, the thickness of the platinum metal layer may be 2 μm to 10 μm. In some examples of this embodiment, the thickness of the platinum metal layer is 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, or the thickness of the platinum metal layer may be in a range between any two of the above thicknesses.

[0058] In some examples of this embodiment, the platinum metal layer may be formed on the substrate 110 by electroplating. In the step of forming the platinum metal layer, the substrate 110 may be placed in a platinum plating solution, and a current may be applied to the substrate 110 to electroplate platinum on the substrate 110 and form the platinum metal layer.

[0059] Step S2: preparing a platinum-containing alloy material layer based on the platinum metal layer.

[0060] In this embodiment, the platinum-containing alloy material layer includes a γ-phase material, and the alloy material layer can serve as a precursor of the first sub-coating layer.

[0061] In some examples of this embodiment, the substrate 110 includes nickel, and the step of preparing the platinum-containing alloy material layer based on the platinum metal layer includes: placing the substrate 110 in a vacuum environment, heating the platinum metal layer, and combining the platinum metal layer with the nickel element in the substrate 110 to form the alloy material layer. It will be understood that under the heating condition, the nickel atoms in the substrate 110 can diffuse into the platinum metal layer and combine with the platinum atoms in the platinum metal layer to form a γ-phase material.

[0062] In some examples of this embodiment, in the step of heating the platinum metal layer, the temperature of the platinum metal layer can be controlled to be 900° C. to 1150° C. For example, the temperature of the platinum metal layer can be controlled to be 900° C., 920° C., 950° C., 970° C., 1000° C., 1020° C., 1050° C., 1070° C., 1100° C., 1120° C., or 1150° C. Alternatively, the temperature of the platinum metal layer can be controlled to be within a range between any two of the above temperatures.

[0063] In some examples of this embodiment, in the step of preparing the platinum-containing alloy material layer based on the platinum metal layer, the vacuum degree of the vacuum environment can be controlled to be less than 10 -3 Pa.

[0064] In some examples of this embodiment, in the step of preparing a platinum-containing alloy material layer based on a platinum metal layer, the treatment time can be controlled to be 2 hours to 6 hours. For example, the treatment time can be controlled to be 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, or 6 hours, or the treatment time can be controlled to be within a range between any two of the above time periods.

[0065] Step S3: performing aluminizing treatment on the alloy material layer to convert a portion of the alloy material layer into β-phase material.

[0066] In this embodiment, when the alloy material layer is aluminized, aluminum atoms enter the surface portion of the γ-phase material to form a β-phase material. It is understood that the second sub-coating layer 130 may include the β-phase material.

[0067] Furthermore, in this embodiment, when the alloy material layer is aluminized, aluminum atoms enter the γ phase material in the underlying layer, thereby forming a γ+γ' phase material. The first sub-coating layer 120 may include a γ+γ' phase material.

[0068] In some examples of this embodiment, the step of performing aluminizing treatment on the alloy material layer includes: performing vapor phase aluminizing treatment on the alloy material layer to convert part of the alloy material layer into β-phase material, and during the vapor phase aluminizing treatment, the aluminizing agent includes a catalyst and an aluminizing source.

[0069] In some examples of this embodiment, when the alloy material layer is subjected to an aluminizing treatment, the aluminizing source includes one or more of an iron-aluminum alloy and a nickel-aluminum alloy.

[0070] Furthermore, in some examples of this embodiment, when the alloy material layer is subjected to aluminizing treatment, the catalyst may be selected from one or more of ammonium bifluoride and ammonium bichloride.

[0071] By using iron-aluminum alloy or nickel-aluminum alloy as the aluminum diffusion source and combining it with ammonium bifluoride or ammonium bichloride as a catalyst, the aluminum element can be controlled to penetrate into the surface of the alloy material layer more evenly and gradually form a β-phase material. In addition, the aluminum element is less likely to penetrate into the bottom layer, so that part of the alloy material layer located at the bottom layer forms a γ+γ' phase material, thereby realizing the preparation of stacked γ+γ' phase material and β-phase material.

[0072] In some examples of this embodiment, the aluminizing agent may consist of an aluminizing source and a catalyst.

[0073] In some examples of this embodiment, the mass proportion of the aluminizing source in the aluminizing agent is 95% to 99%. For example, the mass proportion of the aluminizing source can be controlled to be 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, or 99%, or the mass proportion of the aluminizing source can be controlled to be within a range between any two of the above mass proportions.

[0074] In some examples of this embodiment, the catalyst may comprise 1% to 3% by mass of the aluminizing agent. For example, the catalyst may comprise 1%, 1.5%, 2%, 2.5%, or 3% by mass, or may comprise any range between any two of the above ranges.

[0075] In some examples of this embodiment, during the vapor phase aluminizing process, the aluminizing temperature can be controlled to be 850° C. to 1200° C. For example, the aluminizing temperature can be controlled to be 860° C., 870° C., 880° C., 900° C., 920° C., 940° C., 950° C., 960° C., 980° C., 1000° C., 1050° C., 1100° C., 1150° C., or 1200° C. Alternatively, the aluminizing temperature can be controlled to be within a range between any two of the above temperatures.

[0076] In some examples of this embodiment, during the vapor phase aluminizing treatment, the aluminizing time can be controlled to be 2h~12h. For example, the aluminizing time can be controlled to be 2h, 3h, 4h, 6h, 8h, 10h, 12h, or the aluminizing time can be controlled to be within the range between any two of the above times. The effect of controlling the aluminizing time can be used to control the thickness of the formed β-phase material to avoid the β-phase material completely replacing the γ+γ' phase structure, thereby forming a stacked first sub-coating and a second sub-coating. The aluminizing time can be controlled based on the aluminizing temperature. For example, when the aluminizing temperature is high, the aluminizing time can be controlled to be shorter, and when the aluminizing temperature is low, the aluminizing time can be controlled to be longer.

[0077] By controlling the parameters of the above-mentioned vapor phase aluminizing, a β-phase material with a more uniform growth thickness can be obtained. At the same time, the thickness of the γ+γ' phase material in the platinum aluminum coating can be ensured to be more uniform and continuous, thereby further improving the problem of mutual diffusion and improving the anti-oxidation effect of the coating.

[0078] It can be understood that through steps S1 to S3, the following can be prepared: Figure 1 The platinum-aluminum coating shown. Compared to the conventional process flow for preparing only β-phase platinum-aluminum coatings, this preparation process does not add more complex new processes or introduce new processing steps. Through structural improvements and corresponding preparation methods, the present invention can meet the requirements of the bonding layer without significantly increasing the preparation difficulty, while also preventing interdiffusion with the substrate 110.

[0079] In order to facilitate understanding of the technical solution of the present invention, more specific embodiments and comparative examples are provided below. Through the description of the embodiments and comparative examples, the specific implementation of the present invention will be easier to understand, and the advantages of the present invention will also be more obvious.

[0080] Example 1

[0081] DZ406 high temperature alloy is provided as a substrate.

[0082] A platinum metal layer with a thickness of 5 μm was electroplated on the DZ406 high-temperature alloy.

[0083] Place the DZ406 high temperature alloy plated with platinum metal layer in a vacuum chamber and control the pressure of the vacuum chamber to be greater than 10 - 3 Pa, control the temperature in the vacuum chamber to 1050℃, keep it warm for 4 hours and then take it out.

[0084] The DZ406 high-temperature alloy was transferred to a vapor aluminizing chamber, and a mixture of iron-aluminum alloy and ammonium bifluoride was used as the aluminizing agent, with ammonium bifluoride accounting for 1% by mass and the balance being iron-aluminum alloy. The temperature of the vapor aluminizing chamber was controlled to be 870°C and the aluminizing time was 10 hours. The cross-sectional scanning electron microscope observation image of the platinum-aluminum coating prepared in Example 1 can be seen in Figure 3 .

[0085] Example 2

[0086] DD6 high temperature alloy is provided as a substrate.

[0087] A platinum metal layer with a thickness of 6 μm was electroplated on the DD6 high temperature alloy.

[0088] Place the DD6 high temperature alloy plated with platinum metal layer in a vacuum chamber and control the pressure of the vacuum chamber to be greater than 10 - 3Pa, control the temperature in the vacuum chamber to 1150℃, keep it warm for 2h and then take it out.

[0089] The DD6 high-temperature alloy was transferred to a vapor aluminizing chamber, and a mixture of nickel-aluminum alloy and ammonium bifluoride was used as the aluminizing agent. The mass proportion of ammonium bichloride was 3%, and the balance was nickel-aluminum alloy. The temperature of the vapor aluminizing chamber was controlled to be 1080°C and the aluminizing time was 2 hours. The cross-sectional scanning electron microscopy observation of the platinum-aluminum coating prepared in Example 2 can be seen in Figure 4 .

[0090] Comparative Example 1

[0091] DZ406 high temperature alloy is provided as a substrate.

[0092] A platinum metal layer with a thickness of 5 μm was electroplated on the DZ406 high-temperature alloy.

[0093] Place the DZ406 high temperature alloy plated with platinum metal layer in a vacuum chamber and control the pressure of the vacuum chamber to be greater than 10 - 3 Pa, control the temperature in the vacuum chamber to 1050℃, keep it warm for 4 hours and then take it out.

[0094] The DZ406 high-temperature alloy was transferred to a vapor aluminizing chamber. A mixture of iron-aluminum alloy and ammonium fluoride was used as the aluminizing agent. The mass proportion of ammonium fluoride was 1%, and the balance was iron-aluminum alloy. The temperature of the vapor aluminizing chamber was controlled to 870°C and the aluminizing time was 10 hours. The cross-sectional scanning electron microscope observation image of the platinum-aluminum coating prepared in Comparative Example 1 can be seen in Figure 5 .

[0095] Comparative Example 2

[0096] DZ406 high temperature alloy is provided as a substrate.

[0097] A platinum metal layer with a thickness of 5 μm was electroplated on the DZ406 high-temperature alloy.

[0098] Place the DZ406 high temperature alloy plated with platinum metal layer in a vacuum chamber and control the pressure of the vacuum chamber to be greater than 10 - 3 Pa, control the temperature in the vacuum chamber to 1050℃, keep it warm for 4 hours and then take it out.

[0099] The DZ406 high-temperature alloy was transferred to a vapor aluminizing chamber. A mixture of iron-aluminum alloy and ammonium bifluoride was used as the aluminizing agent. The mass proportion of ammonium bifluoride was 10%, and the balance was iron-aluminum alloy. The temperature of the vapor aluminizing chamber was controlled to be 1080°C and the aluminizing time was 2 hours. The cross-sectional scanning electron microscopy observation of the platinum-aluminum coating prepared in Comparative Example 2 can be seen in Figure 6 .

[0100] Reference Figure 3 As shown, Figure 3 Depending on the substrate, the coating consists of the substrate, the first sub-coating, and the second sub-coating from bottom to top. The second sub-coating is separated from the substrate by the first sub-coating. The second sub-coating, located at the top, has a higher aluminum content and is primarily composed of a platinum-containing β-phase material. The first sub-coating has a lower aluminum content and is primarily composed of a platinum-containing γ+γ' phase material. Figure 4 The structure shown in Figure 3 The structure shown in is similar. Figure 3 and Figure 4 It is illustrated that the preparation methods of Example 1 and Example 2 can prepare a platinum-aluminum coating including a first sub-coating and a second sub-coating.

[0101] Figure 5 Schematic diagram of the cross-sectional structure of the coating prepared in Comparative Example 1, Figure 6 This is a schematic diagram of the cross-sectional structure of the coating prepared in Comparative Example 1. Figure 5 and Figure 6 As shown, both Comparative Examples 1 and 2 produced a surface β-phase material. Furthermore, a TCP precipitate formed between the β-phase material and the substrate, rather than a γ+γ' phase. The aluminum content in the TCP precipitate was typically greater than 25%. This indicates that during aluminization in Comparative Examples 1 and 2, the aluminum content in the coatings was too high and the aluminum penetrated too deeply, preventing the simultaneous formation of both the β-phase and the γ+γ' phases.

[0102] Please note that the above embodiments are for illustrative purposes only and are not intended to be limiting of this document.

[0103] It should be understood that, unless otherwise expressly stated herein, there is no strict order restriction for the execution of steps, and these steps may be executed in other orders. Furthermore, at least a portion of the steps in the preparation process may include multiple sub-steps or multiple stages, and these sub-steps or stages do not necessarily need to be completed at the same time, but may also be executed at different times. The order of execution of these sub-steps or stages is not necessarily sequential, but may be executed in rotation or alternation with other steps or at least a portion of the sub-steps or stages of other steps.

[0104] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0105] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A method for preparing a platinum aluminum coating, characterized in that: The platinum-aluminum coating comprises a first sub-coating and a second sub-coating, wherein the first sub-coating and the second sub-coating are sequentially stacked on a substrate, wherein the first sub-coating comprises a platinum-containing γ+γ' phase material, and the second sub-coating comprises a platinum-containing β phase material, and the aluminum content in the first sub-coating is lower than the aluminum content in the second sub-coating; the preparation method comprises the following steps: Preparing a platinum metal layer on a substrate, and preparing a platinum-containing alloy material layer based on the platinum metal layer, wherein the alloy material layer includes a γ-phase material; The alloy material layer is subjected to an aluminizing treatment so that the top portion of the alloy material layer is converted into a β-phase material to form the second sub-coating, and at least the portion of the alloy material layer below the second sub-coating is converted into a γ+γ' phase material to form the first sub-coating.

2. The method for preparing the platinum-aluminum coating according to claim 1, characterized in that: The step of performing aluminizing treatment on the alloy material layer includes: performing vapor phase aluminizing treatment on the alloy material layer to convert part of the alloy material layer into β-phase material. During the vapor phase aluminizing treatment, the aluminizing agent includes a catalyst and an aluminizing source, the catalyst includes one or more of ammonium bifluoride and ammonium bichloride, and the aluminizing source is selected from one or more of nickel-aluminum alloy and iron-aluminum alloy.

3. The method for preparing the platinum-aluminum coating according to claim 2, characterized in that: In the aluminizing agent, the mass proportion of the aluminizing source is 95% to 99%; and / or, The mass proportion of the catalyst is 1% to 3%.

4. The method for preparing the platinum-aluminum coating according to claim 3, characterized in that: During the vapor phase aluminizing process, the aluminizing temperature is controlled to be 850°C to 1200°C.

5. The method for preparing a platinum-aluminum coating according to any one of claims 1 to 4, characterized in that: The thickness of the platinum metal layer is 2 μm to 10 μm.

6. The method for preparing a platinum-aluminum coating according to any one of claims 1 to 4, characterized in that: The substrate includes nickel elements, and the steps of preparing a platinum-containing alloy material layer based on the platinum metal layer include: placing the substrate in a vacuum environment, heating the platinum metal layer and controlling the temperature of the platinum metal layer to 900°C~1150°C, so that the platinum metal layer is combined with the nickel elements in the substrate to form the alloy material layer.

7. The method for preparing a platinum-aluminum coating according to any one of claims 1 to 4, characterized in that: The atomic weight of aluminum in the first sub-coating layer accounts for less than 25%.

8. The method for preparing a platinum-aluminum coating according to any one of claims 1 to 4, characterized in that: The atomic weight of aluminum in the second sub-coating layer accounts for 30% to 60%.

9. The method for preparing a platinum-aluminum coating according to any one of claims 1 to 4, characterized in that: The thickness of the first sub-coating layer is 5 μm to 30 μm; and / or, The thickness of the second sub-coating layer is 10 μm to 50 μm.

10. An engine, characterized in that: It comprises an engine substrate and a platinum-aluminum coating prepared by the preparation method according to any one of claims 1 to 9, wherein the first sub-coating and the second sub-coating in the platinum-aluminum coating are sequentially stacked on the engine substrate.

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