Wear-resistant and corrosion-resistant thermal barrier composite coating and preparation method thereof

Abstract

The invention provides a wear-resistant and corrosion-resistant thermal barrier composite coating and a preparation method thereof, and relates to the technical field of material surface engineering. The wear-resistant and corrosion-resistant thermal barrier composite coating comprises a wear-resistant and corrosion-resistant layer formed on the surface of a base body, and the material of the wear-resistant and corrosion-resistant layer is one or more of WC-6Co, WC-12Co, WC-17Co, WC-10Co-4Cr, WC-9Co-5Cr-1Ni, WC-10Ni-5Cr and WC-20Cr3C2-7Ni; the thermal barrier layer is formed on the surface of the wear-resistant and corrosion-resistant layer, and the material of the thermal barrier layer is one or more of YSZ (Yttria Stabilized Zirconia), La2Zr2O7, Gd2Zr2O7, Sc2O3-Y2O3-ZrO2, La2Hf2O7, Yb2SiO5, Y2SiO5, YNbO4 and GdTaO4. The performance of the coating can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of materials surface engineering technology, and more specifically, to a wear-resistant and corrosion-resistant thermal barrier composite coating and its preparation method. Background Technology

[0002] With the rapid development of modern industry towards high temperature, high speed, and high load, the service environment of key hot-end components (such as aero-engine turbine blades, gas turbine blades, and high-temperature valves) is becoming increasingly harsh. These components are not only exposed to high-temperature oxidizing and hot corrosive atmospheres for extended periods, but also frequently endure severe mechanical wear, solid particle erosion, and frequent thermal cycling. Their base materials are mostly high-temperature alloys, but even the most advanced nickel-based or cobalt-based high-temperature alloys are approaching their service limits in terms of melting point, high-temperature strength, and corrosion resistance, making it difficult to meet the higher performance and lifespan requirements of next-generation equipment.

[0003] To protect these expensive core components, surface protection technologies, especially thermal barrier coatings, have become indispensable. However, poor coating performance is a common problem at present.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to provide a wear-resistant and corrosion-resistant thermal barrier composite coating and its preparation method, thereby overcoming, at least to some extent, the problem of poor coating performance.

[0006] According to a first aspect of this disclosure, a wear-resistant and corrosion-resistant thermal barrier composite coating is provided, comprising: a wear-resistant and corrosion-resistant layer formed on the surface of a substrate, wherein the material of the wear-resistant and corrosion-resistant layer is one or more selected from WC-6Co, WC-12Co, WC-17Co, WC-10Co-4Cr, WC-9Co-5Cr-1Ni, WC-10Ni-5Cr, and WC-20Cr3C2-7Ni; and a thermal barrier layer formed on the surface of the wear-resistant and corrosion-resistant layer, wherein the material of the thermal barrier layer is one or more selected from YSZ, La2Zr2O7, Gd2Zr2O7, Sc2O3-Y2O3-ZrO2, La2Hf2O7, Yb2SiO5, Y2SiO5, YNbO4, and GdTaO4.

[0007] Optionally, the matrix is ​​a titanium alloy, a nickel-based high-temperature alloy, a cobalt-based high-temperature alloy, or an iron-based heat-resistant alloy.

[0008] According to a second aspect of this disclosure, a method for preparing a wear-resistant and corrosion-resistant thermal barrier composite coating is provided, comprising: coating a wear-resistant and corrosion-resistant layer on the surface of a substrate by supersonic flame spraying, wherein the material of the wear-resistant and corrosion-resistant layer is one or more of WC-6Co, WC-12Co, WC-17Co, WC-10Co-4Cr, WC-9Co-5Cr-1Ni, WC-10Ni-5Cr, and WC-20Cr3C2-7Ni; and coating a thermal barrier layer on the surface of the wear-resistant and corrosion-resistant layer by plasma spraying, wherein the material of the thermal barrier layer is one or more of YSZ, La2Zr2O7, Gd2Zr2O7, Sc2O3-Y2O3-ZrO2, La2Hf2O7, Yb2SiO5, Y2SiO5, YNbO4, and GdTaO4.

[0009] Optionally, during the supersonic flame spraying process, the fuel flow rate is 20~30L / h, the oxygen flow rate is 700~900L / min, the carrier gas flow rate is 5~10L / min, and the powder feeding rate is 70~100g / min.

[0010] Optionally, during supersonic flame spraying, the spraying distance is 30~50cm.

[0011] Optionally, during plasma spraying, the spraying power is 40~60kW, the main gas flow rate is 40~150L / min, and the powder feeding rate is 20~50g / min.

[0012] Optionally, during plasma spraying, the spraying distance is 8~20cm.

[0013] Optionally, before applying the wear-resistant and corrosion-resistant layer to the surface of the substrate using supersonic flame spraying, the preparation method further includes: sequentially cleaning, drying, and roughening the substrate.

[0014] Optionally, a roughening process is performed to control the surface roughness of the substrate to be greater than or equal to 3.2 μm and less than or equal to 6.3 μm.

[0015] Optionally, the matrix is ​​a titanium alloy, a nickel-based high-temperature alloy, a cobalt-based high-temperature alloy, or an iron-based heat-resistant alloy.

[0016] In the exemplary embodiments of this disclosure, WC (tungsten carbide)-based cermet is used as the wear-resistant and corrosion-resistant underlayer to replace the traditional MCrAlY bonding layer, and combined with a multi-element thermal barrier ceramic top layer. A robust and integrated synergistic protection system is constructed using a combination of supersonic flame spraying and plasma spraying technologies. On one hand, this system not only significantly improves the coating's wear resistance, erosion resistance, and corrosion resistance through the high hardness and toughness of the wear-resistant and corrosion-resistant layer, but also effectively blocks high-temperature attack thanks to the excellent thermal insulation and phase stability of the top layer material. On the other hand, the extremely high interfacial bonding strength and dense structure provided by the supersonic flame spraying technology, along with the thermal expansion gradient design between the two layers, jointly ensure the coating's excellent thermal shock fatigue resistance under thermo-mechanical coupling loads. This systematically solves the key problem of traditional thermal barrier coatings having limited protective functions and being prone to early failure under extreme and complex working conditions, significantly extending the service life of core hot-end components. Furthermore, the spraying scheme adopted in this disclosure is stable and reliable, requiring no complex equipment modification or special material pretreatment, and is easy to industrialize. Meanwhile, by adjusting the process parameters, it can be adapted to a variety of substrate materials, with strong coating compatibility. It does not require complex substrate pretreatment, can cover the protection needs of more industrial fields, and has high market application value.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0019] Figure 1 A schematic diagram of the structure of the wear-resistant and corrosion-resistant thermal barrier composite coating according to an embodiment of the present disclosure is shown.

[0020] Figure 2 A flowchart illustrating the preparation method of the wear-resistant and corrosion-resistant thermal barrier composite coating according to an embodiment of the present disclosure is shown.

[0021] Figure 3 The microstructure of the wear-resistant and corrosion-resistant thermal barrier composite coating of Embodiment 1 of this disclosure is shown. Detailed Implementation

[0022] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of these specific details omitted, or other methods, processes, steps, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0023] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. The flowcharts shown in the drawings are merely exemplary illustrations and do not necessarily include all steps. For example, some steps may be broken down, while others may be combined or partially combined; therefore, the actual order of execution may change depending on the specific circumstances.

[0024] In some solutions, the thermal barrier coating system adopts a two-layer structure of "metal bonding layer (such as MCrAlY, M=Ni, Co, etc.) + ceramic surface layer (such as YSZ coating)". However, when dealing with complex working conditions where there is both severe mechanical wear and high-temperature corrosion, the YSZ ceramic layer is brittle and has poor toughness, making it prone to cracking and rapid peeling, leading to failure of the thermal insulation function. The MCrAlY layer cannot provide effective wear-resistant protection and will quickly wear down, resulting in damage to the substrate.

[0025] This disclosure provides a composite coating with high wear resistance, erosion resistance and excellent thermal barrier properties, and a method for preparing the same, to solve some technical problems of insufficient wear resistance and erosion resistance caused by the high brittleness of the ceramic layer and the softness of the adhesive layer in some thermal barrier coating systems, as well as their tendency to fail prematurely under mechanical-thermal coupling loads.

[0026] Figure 1 A schematic diagram illustrating the structure of the wear-resistant and corrosion-resistant thermal barrier composite coating according to an embodiment of this disclosure is shown. (Reference) Figure 1The wear-resistant and corrosion-resistant thermal barrier composite coating of this disclosure may include a wear-resistant and corrosion-resistant layer formed on the surface of a substrate and a thermal barrier layer formed on the surface of the wear-resistant and corrosion-resistant layer. The wear-resistant and corrosion-resistant layer is made of one or more of WC-6Co, WC-12Co, WC-17Co, WC-10Co-4Cr, WC-9Co-5Cr-1Ni, WC-10Ni-5Cr, and WC-20Cr3C2-7Ni. The thermal barrier layer is made of one or more of YSZ, La2Zr2O7, Gd2Zr2O7, Sc2O3-Y2O3-ZrO2, La2Hf2O7, Yb2SiO5, Y2SiO5, YNbO4, and GdTaO4.

[0027] This wear-resistant and corrosion-resistant thermal barrier composite coating can be applied to various hot-end components, such as aero-engine turbine blades, gas turbine blades, and high-temperature valves. Correspondingly, the substrate can be titanium alloy, nickel-based high-temperature alloy, cobalt-based high-temperature alloy, or iron-based heat-resistant alloy, and this disclosure does not impose any restrictions on it.

[0028] In wear-resistant and corrosion-resistant thermal barrier composite coatings, the wear-resistant and corrosion-resistant layer is the bottom layer, and the thermal barrier layer is the top layer. The hardness of the wear-resistant and corrosion-resistant layer is greater than or equal to 1000 HV. 0.3 The coating's bonding strength is greater than or equal to 70 MPa, and the coating's volumetric erosion rate is less than or equal to 5 mm. 3 / g, 1100℃ (holding temperature for 5 min) - the number of thermal shocks under water quenching is greater than or equal to 120.

[0029] Figure 2 A flowchart illustrating the preparation method of the wear-resistant and corrosion-resistant thermal barrier composite coating according to an embodiment of this disclosure is shown schematically. (Reference) Figure 2 The method for preparing the wear-resistant and corrosion-resistant thermal barrier composite coating according to the present disclosure may include the following steps: S22. Apply a wear-resistant and corrosion-resistant layer to the surface of the substrate using supersonic flame spraying.

[0030] In an exemplary embodiment of this disclosure, the material of the wear-resistant and corrosion-resistant layer is one or more of WC-6Co, WC-12Co, WC-17Co, WC-10Co-4Cr, WC-9Co-5Cr-1Ni, WC-10Ni-5Cr, and WC-20Cr3C2-7Ni.

[0031] The matrix can be titanium alloy, nickel-based superalloy, cobalt-based superalloy or iron-based heat-resistant alloy.

[0032] During the supersonic flame spraying process, the fuel flow rate is 20~30L / h, the oxygen flow rate is 700~900L / min, the carrier gas flow rate is 5~10L / min, the powder feeding rate is 70~100g / min, and the spraying distance is 30~50cm.

[0033] S24. A thermal barrier layer is applied to the surface of the wear-resistant and corrosion-resistant layer using plasma spraying.

[0034] In an exemplary embodiment of this disclosure, the material of the thermal barrier layer is one or more of YSZ, La2Zr2O7, Gd2Zr2O7, Sc2O3-Y2O3-ZrO2, La2Hf2O7, Yb2SiO5, Y2SiO5, YNbO4, and GdTaO4.

[0035] During plasma spraying, the spraying power is 40~60kW, the main gas flow rate is 40~150L / min, the powder feeding rate is 20~50g / min, and the spraying distance is 8~20cm.

[0036] According to some embodiments of this disclosure, before applying a wear-resistant and corrosion-resistant layer to the surface of a substrate using supersonic flame spraying, the substrate can be sequentially cleaned, dried, and roughened. The roughening process is performed to control the surface roughness of the substrate to be greater than or equal to 3.2 μm and less than or equal to 6.3 μm.

[0037] The embodiments and comparative examples of the present disclosure will be used to illustrate the solutions of the present disclosure.

[0038] Example 1

[0039] The wear-resistant and corrosion-resistant thermal barrier composite coating may include a wear-resistant and corrosion-resistant layer formed on the surface of the substrate and a thermal barrier layer formed on the surface of the wear-resistant and corrosion-resistant layer. The wear-resistant and corrosion-resistant layer is a WC-17Co coating, and the thermal barrier layer is a YSZ coating.

[0040] The corresponding preparation methods may include: First, the substrate is cleaned and dried, and then roughened using a sandblasting machine. In this embodiment, the substrate is a titanium alloy. During the roughening process of the substrate surface using the sandblasting machine, the surface roughness Ra of the substrate can be adjusted to 4.4 μm by adjusting the sandblasting pressure, distance, and angle.

[0041] Next, WC-17Co powder with a particle size of 15μm to 53μm was coated onto the substrate surface using supersonic flame spraying to form a wear-resistant and corrosion-resistant layer. The process parameters included: fuel flow rate of 25L / h, oxygen flow rate of 800L / min, carrier gas flow rate of 8L / min, powder feed rate of 80g / min, and spraying distance of 40cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 150μm and a porosity of 0.3%.

[0042] Then, YSZ powder with a particle size of 15μm to 53μm was coated onto the WC-17Co coating surface using plasma spraying to form a thermal barrier layer. The process parameters included: spraying power of 42kW, main gas flow rate of 40L / min, powder feed rate of 25g / min, and spraying distance of 12cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 120μm and a porosity of 7.2%.

[0043] Figure 3 A microscopic morphology image of the wear-resistant and corrosion-resistant thermal barrier composite coating of Embodiment 1 of this disclosure is shown. The resin on the thermal barrier layer is used for subsequent mounting. (Reference) Figure 3 The wear-resistant and corrosion-resistant thermal barrier composite coating prepared in Example 1 of this disclosure has a tight bond between its layers and no obvious defects such as cracks.

[0044] Example 2

[0045] The wear-resistant and corrosion-resistant thermal barrier composite coating may include a wear-resistant and corrosion-resistant layer formed on the surface of the substrate and a thermal barrier layer formed on the surface of the wear-resistant and corrosion-resistant layer. The wear-resistant and corrosion-resistant layer is a WC-10Co-4Cr coating, and the thermal barrier layer is a Gd2Zr2O7 coating.

[0046] The corresponding preparation methods may include: First, the substrate is cleaned and dried, and then roughened using a sandblasting machine. In this embodiment, the substrate is a nickel-based high-temperature alloy. During the roughening process of the substrate surface using the sandblasting machine, the surface roughness Ra of the substrate can be adjusted to 6.3 μm by adjusting the sandblasting pressure, distance, and angle.

[0047] Next, WC-10Co-4Cr powder with a particle size of 15μm to 45μm was coated onto the substrate surface using supersonic flame spraying to form a wear-resistant and corrosion-resistant layer. The process parameters included: fuel flow rate of 30L / h, oxygen flow rate of 900L / min, carrier gas flow rate of 10L / min, powder feed rate of 90g / min, and spraying distance of 50cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 50μm and a porosity of 0.1%.

[0048] Then, Gd₂Zr₂O₇ powder with a particle size of 15μm to 53μm was coated onto the WC-10Co-4Cr coating surface using plasma spraying to form a thermal barrier layer. The process parameters included: spraying power of 60kW, main gas flow rate of 100L / min, powder feed rate of 30g / min, and spraying distance of 15cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 100μm and a porosity of 3.0%.

[0049] Example 3

[0050] The wear-resistant and corrosion-resistant thermal barrier composite coating may include a wear-resistant and corrosion-resistant layer formed on the surface of the substrate and a thermal barrier layer formed on the surface of the wear-resistant and corrosion-resistant layer. Specifically, the wear-resistant and corrosion-resistant layer is a WC-10Ni-5Cr coating, and the thermal barrier layer is a Sc2O3-Y2O3-ZrO2 coating.

[0051] The corresponding preparation methods may include: First, the substrate is cleaned and dried, and then roughened using a sandblasting machine. In this embodiment, the substrate is a cobalt-based high-temperature alloy. During the roughening process of the substrate surface using the sandblasting machine, the surface roughness Ra of the substrate can be adjusted to 3.2 μm by adjusting the sandblasting pressure, distance, and angle.

[0052] Next, WC-10Ni-5Cr powder with a particle size of 15μm to 53μm was coated onto the substrate surface using supersonic flame spraying to form a wear-resistant and corrosion-resistant layer. The process parameters included: fuel flow rate of 20L / h, oxygen flow rate of 700L / min, carrier gas flow rate of 6L / min, powder feed rate of 100g / min, and spraying distance of 30cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 100μm and a porosity of 1.0%.

[0053] Then, Sc2O3-Y2O3-ZrO2 powder with a particle size of 15μm to 75μm was coated onto the surface of the WC-10Ni-5Cr coating using plasma spraying to form a thermal barrier layer. The process parameters included: spraying power of 50kW, main gas flow rate of 150L / min, powder feed rate of 50g / min, and spraying distance of 20cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 100μm and a porosity of 8.0%.

[0054] Example 4

[0055] The wear-resistant and corrosion-resistant thermal barrier composite coating may include a wear-resistant and corrosion-resistant layer formed on the surface of the substrate and a thermal barrier layer formed on the surface of the wear-resistant and corrosion-resistant layer. Specifically, the wear-resistant and corrosion-resistant layer is a WC-20Cr3C2-7Ni coating, and the thermal barrier layer is a La2Hf2O7 coating.

[0056] The corresponding preparation methods may include: First, the substrate is cleaned and dried, and then roughened using a sandblasting machine. In this embodiment, the substrate is an iron-based heat-resistant alloy. During the roughening process of the substrate surface using the sandblasting machine, the surface roughness Ra of the substrate can be adjusted to 3.5 μm by adjusting the sandblasting pressure, distance, and angle.

[0057] Next, WC-20Cr3C2-7Ni powder with a particle size of 15μm to 45μm was coated onto the substrate surface using supersonic flame spraying to form a wear-resistant and corrosion-resistant layer. The process parameters included: fuel flow rate of 22L / h, oxygen flow rate of 830L / min, carrier gas flow rate of 5L / min, powder feed rate of 70g / min, and spraying distance of 40cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 80μm and a porosity of 0.8%.

[0058] Then, La2Hf2O7 powder with a particle size of 15μm to 45μm was coated onto the surface of the WC-20Cr3C2-7Ni coating using plasma spraying to form a thermal barrier layer. The process parameters included: spraying power of 40kW, main gas flow rate of 80L / min, powder feed rate of 20g / min, and spraying distance of 8cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 200μm and a porosity of 5.7%.

[0059] Comparative Example 1

[0060] The wear-resistant and corrosion-resistant thermal barrier composite coating may include a wear-resistant and corrosion-resistant layer formed on the surface of a substrate and a thermal barrier layer formed on the surface of the wear-resistant and corrosion-resistant layer. The wear-resistant and corrosion-resistant layer is a NiCrAlY coating, and the thermal barrier layer is a YSZ coating.

[0061] The corresponding preparation methods may include: First, the substrate is cleaned and dried, and then roughened using a sandblasting machine. In this embodiment, the substrate is a titanium alloy. During the roughening process of the substrate surface using the sandblasting machine, the surface roughness Ra of the substrate can be adjusted to 4.4 μm by adjusting the sandblasting pressure, distance, and angle.

[0062] Next, NiCrAlY powder with a particle size of 15μm to 53μm was coated onto the substrate surface using plasma spraying to form a wear-resistant and corrosion-resistant layer. The process parameters included: spraying power of 45kW, main gas flow rate of 50L / min, powder feed rate of 30g / min, and spraying distance of 12cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 150μm and a porosity of 3.0%.

[0063] Then, YSZ powder with a particle size of 15μm to 53μm was coated onto the NiCrAlY coating surface using plasma spraying to form a thermal barrier layer. The process parameters included: spraying power of 42kW, main gas flow rate of 40L / min, powder feed rate of 25g / min, and spraying distance of 12cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 120μm and a porosity of 7.2%.

[0064] Comparative Example 2

[0065] The wear-resistant and corrosion-resistant thermal barrier composite coating may include a wear-resistant and corrosion-resistant layer formed on the surface of a substrate and a thermal barrier layer formed on the surface of the wear-resistant and corrosion-resistant layer. The wear-resistant and corrosion-resistant layer is a NiCrAlY coating, and the thermal barrier layer is a YSZ coating.

[0066] The corresponding preparation methods may include: First, the substrate is cleaned and dried, and then roughened using a sandblasting machine. In this embodiment, the substrate is a titanium alloy. During the roughening process of the substrate surface using the sandblasting machine, the surface roughness Ra of the substrate can be adjusted to 4.4 μm by adjusting the sandblasting pressure, distance, and angle.

[0067] Next, NiCrAlY powder with a particle size of 15μm to 53μm was coated onto the substrate surface using supersonic flame spraying to form a wear-resistant and corrosion-resistant layer. The process parameters included: fuel flow rate of 25L / h, oxygen flow rate of 800L / min, carrier gas flow rate of 8L / min, powder feed rate of 80g / min, and spraying distance of 40cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 150μm and a porosity of 0.5%.

[0068] Then, YSZ powder with a particle size of 15μm to 53μm was coated onto the NiCrAlY coating surface using plasma spraying to form a thermal barrier layer. The process parameters included: spraying power of 42kW, main gas flow rate of 40L / min, powder feed rate of 25g / min, and spraying distance of 12cm. The resulting wear-resistant and corrosion-resistant layer had a thickness of 120μm and a porosity of 7.2%.

[0069] The coatings prepared in the above embodiments and comparative examples were tested for underlayer hardness, bond strength, volumetric erosion rate, and thermal shock performance under 1100℃ (holding temperature for 5 min) and water quenching. The test results are shown in Table 1. Table 1

[0070] As can be seen from Table 1, compared with Examples 1 to 4, Comparative Examples 1 and 2 are inferior in all four indicators: substrate hardness, bonding strength, coating volume erosion rate, and thermal shock resistance. In other words, the solution of this disclosure can improve the overall performance of the coating, and the coating performance can be controlled by adjusting the coating process parameters.

[0071] It should be noted that although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0072] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this disclosure and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0073] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0074] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A wear-resistant and corrosion-resistant thermal barrier composite coating, characterized in that, include: A wear-resistant and corrosion-resistant layer formed on the surface of a substrate, wherein the material of the wear-resistant and corrosion-resistant layer is one or more of WC-6Co, WC-12Co, WC-17Co, WC-10Co-4Cr, WC-9Co-5Cr-1Ni, WC-10Ni-5Cr, and WC-20Cr3C2-7Ni; A thermal barrier layer is formed on the surface of the wear-resistant and corrosion-resistant layer, wherein the material of the thermal barrier layer is one or more of YSZ, La2Zr2O7, Gd2Zr2O7, Sc2O3-Y2O3-ZrO2, La2Hf2O7, Yb2SiO5, Y2SiO5, YNbO4, and GdTaO4.

2. The wear-resistant and corrosion-resistant thermal barrier composite coating according to claim 1, characterized in that, The matrix is ​​a titanium alloy, a nickel-based high-temperature alloy, a cobalt-based high-temperature alloy, or an iron-based heat-resistant alloy.

3. A method for preparing a wear-resistant and corrosion-resistant thermal barrier composite coating, characterized in that, include: A wear-resistant and corrosion-resistant layer is coated on the surface of the substrate using supersonic flame spraying. The material of the wear-resistant and corrosion-resistant layer is one or more of WC-6Co, WC-12Co, WC-17Co, WC-10Co-4Cr, WC-9Co-5Cr-1Ni, WC-10Ni-5Cr, and WC-20Cr3C2-7Ni. A thermal barrier layer is coated on the surface of the wear-resistant and corrosion-resistant layer by plasma spraying. The material of the thermal barrier layer is one or more of YSZ, La2Zr2O7, Gd2Zr2O7, Sc2O3-Y2O3-ZrO2, La2Hf2O7, Yb2SiO5, Y2SiO5, YNbO4, and GdTaO4.

4. The preparation method according to claim 3, characterized in that, During the supersonic flame spraying process, the fuel flow rate is 20~30L / h, the oxygen flow rate is 700~900L / min, the carrier gas flow rate is 5~10L / min, and the powder feeding rate is 70~100g / min.

5. The preparation method according to claim 3 or 4, characterized in that, During the supersonic flame spraying process, the spraying distance is 30~50cm.

6. The preparation method according to claim 3, characterized in that, During the plasma spraying process, the spraying power is 40~60kW, the main gas flow rate is 40~150L / min, and the powder feeding rate is 20~50g / min.

7. The preparation method according to claim 3 or 6, characterized in that, During the plasma spraying process, the spraying distance is 8~20cm.

8. The preparation method according to claim 3, characterized in that, Before applying a wear-resistant and corrosion-resistant layer to the surface of the substrate using supersonic flame spraying, the preparation method further includes: The substrate is then subjected to cleaning, drying, and roughening treatments in sequence.

9. The preparation method according to claim 8, characterized in that, The roughening process is performed to control the surface roughness of the substrate to be greater than or equal to 3.2 μm and less than or equal to 6.3 μm.

10. The preparation method according to claim 3, 8 or 9, characterized in that, The matrix is ​​a titanium alloy, a nickel-based high-temperature alloy, a cobalt-based high-temperature alloy, or an iron-based heat-resistant alloy.

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