Thermal barrier coating and preparation method thereof, thermal barrier coating workpiece and aviation component

Abstract

The invention relates to the technical field of thermal barrier coating preparation, in particular to a thermal barrier coating and a preparation method thereof, a thermal barrier coating workpiece and an aviation assembly. The preparation method of the thermal barrier coating comprises the following steps that a base body is provided, and a metal bonding layer is prepared on the surface of the base body; preparing a ceramic thermal insulation layer on the surface of one side, deviating from the substrate, of the metal bonding layer by adopting a plasma physical vapor deposition method; the preparation process parameters of the ceramic heat insulation layer are as follows: the Ar gas flow is 10 L / min to 30 L / min, the He gas flow is 40 L / min to 50 L / min, the current is 1000 A to 1400 A, the power is 30 KW to 50 KW, the temperature of the matrix is 600 DEG C to 800 DEG C, and the working air pressure is 2 mbar to 5 mbar. According to the preparation method, the adopted power, the He gas consumption, the power and the current are low, the spraying cost can be effectively reduced, and the preparation method is further suitable for thin-wall or small-size workpieces.

Description

Technical Field

[0001] The present application relates to the technical field of thermal barrier coating preparation, and in particular to thermal barrier coatings and preparation methods thereof, thermal barrier coating workpieces, and aviation components. Background Art

[0002] Thermal barrier coatings (TBCs) technology is a surface protection technology that combines ceramic materials with low thermal conductivity, strong resistance to oxidation and corrosion, and strong temperature resistance with metal substrates in the form of coatings, thereby increasing the operating temperature of metal hot-end components and extending the service life of hot-end components.

[0003] At present, thermal barrier coatings are generally prepared by electron beam-physical vapor deposition (EB-PVD) or atmospheric plasma spray (APS). The above two methods have their own advantages and disadvantages. Among them, the EB-PVD method can prepare thermal barrier coatings with regular structure and excellent thermal shock resistance, but the equipment investment cost of the EB-PVD method is high, the cycle for preparing the coating is long, and the thermal insulation performance of the coating is lower than that of the coating prepared by APS. The APS technology deposits the coating faster, and the prepared coating has excellent thermal insulation performance, but its preparation process needs to be carried out under high jet temperature, high He gas dosage, high power and high current, which greatly increases the spraying cost. In addition, the current thermal barrier coatings are not suitable for thin-walled or small-sized workpieces. Summary of the invention

[0004] Based on this, the present application provides a thermal barrier coating and a preparation method thereof, a thermal barrier coating workpiece, and an aviation component. The thermal barrier coating preparation method provided in the present application uses relatively low power, He gas dosage, power, and current, which can effectively reduce the spraying cost, and the preparation method is also suitable for thin-walled or small-sized workpieces.

[0005] In a first aspect of the present application, a method for preparing a thermal barrier coating is provided, comprising the following steps:

[0006] Providing a substrate, and preparing a metal bonding layer on the surface of the substrate;

[0007] A ceramic heat-insulating layer is prepared on the surface of the metal bonding layer facing away from the substrate by using a plasma physical vapor deposition method;

[0008] The preparation process parameters of the ceramic thermal insulation layer include: Ar gas flow rate of 10L / min~30L / min, He gas flow rate of 40L / min~50L / min, current of 1000A~1400A, power of 30KW~50KW, temperature of the substrate of 600℃~800℃, and working gas pressure of 2mbar~5mbar.

[0009] In one embodiment, the preparation process parameters of the ceramic thermal insulation layer also include:

[0010] The powder feeding rate is 2g / L~10g / L, the powder feeding carrier gas Ar flow rate is 5L / min~9L / min, and the spraying distance is 400mm~800mm.

[0011] In one embodiment, the thickness of the ceramic heat insulation layer is 50 μm to 500 μm; and / or,

[0012] The ceramic heat insulation layer is a columnar crystal structure.

[0013] In one embodiment, the powder used to prepare the ceramic thermal insulation layer is yttria-doped zirconium oxide.

[0014] In one embodiment, the metal bonding layer comprises one or more of MCrAlYSi, MCrAlY and PtAl; wherein M, when it appears each time, is independently one or more of Ni and Co; and / or,

[0015] The thickness of the metal bonding layer is 30 μm to 200 μm.

[0016] In a second aspect of the present application, a thermal barrier coating is provided, comprising:

[0017] Metal bonding layer;

[0018] A ceramic heat-insulating layer is arranged on one side surface of the metal bonding layer, the ceramic heat-insulating layer is prepared by plasma physical vapor deposition, and the ceramic heat-insulating layer has a columnar crystal structure.

[0019] In one embodiment, the thermal barrier coating has one or more of the following features:

[0020] (1) The metal bonding layer includes one or more of MCrAlY and PtAl; wherein M includes one or more of Ni and Co;

[0021] (2) The thickness of the metal bonding layer is 30 μm to 200 μm;

[0022] (3) The thickness of the ceramic thermal insulation layer is 150 μm to 250 μm.

[0023] A third aspect of the present application provides a thermal barrier coating workpiece, comprising a substrate and the thermal barrier coating described in the second aspect of the present application, wherein the metal bonding layer and the ceramic thermal insulation layer in the thermal barrier coating are sequentially arranged on the surface of the substrate.

[0024] In one embodiment, the substrate has one or more of the following features:

[0025] (1) The size of the substrate is 5 mm to 200 mm;

[0026] (2) The substrate is a nickel-based single crystal high-temperature alloy;

[0027] (3) The matrix includes a γ' phase material containing nickel.

[0028] A fourth aspect of the present application provides an aviation component, comprising the thermal barrier coating workpiece described in the third aspect of the present application.

[0029] The preparation method of the thermal barrier coating provided in this application has at least the following advantages:

[0030] In the preparation method of the thermal barrier coating provided in the present application, the metal bonding layer is arranged on the surface of the substrate, which can avoid the bonding difficulty caused by the large difference in the physical and chemical properties of the substrate and the ceramic thermal insulation layer, and can effectively enhance the bonding strength between the ceramic thermal insulation layer and the substrate. The ceramic thermal insulation layer is further prepared by plasma physical vapor deposition, which combines the advantages of low cost and high efficiency of the EB-PVD method and the fast deposition speed of APS, and can realize the large-scale production of low-cost, high thermal insulation performance thermal barrier coatings.

[0031] In addition, the preparation process parameters of the ceramic thermal insulation layer defined in the present application reduce the power, He gas dosage, power and current, realize physical vapor deposition at low power, and can prepare a thermal barrier coating with excellent mechanical properties and excellent thermal insulation properties. Furthermore, the preparation method of the thermal barrier coating provided in the present application is also suitable for thin-walled or small-sized workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A process flow chart of the thermal barrier coating preparation method provided in this application;

[0033] Figure 2 This is a schematic diagram of the structure of a thermal barrier coating workpiece in this application;

[0034] Figure 3~Figure 5 The microscopic morphology of the ceramic thermal insulation layer prepared in Example 1 of the present application at different magnifications;

[0035] Figure 6~Figure 8 Microscopic morphology of the ceramic thermal insulation layer prepared in Comparative Example 1 of the present application at different magnifications.

[0036] Description of reference numerals:

[0037] In the figure, 10 is a substrate, 20 is a metal bonding layer, and 30 is a ceramic heat insulation layer. DETAILED DESCRIPTION

[0038] The following is a further complete and clear description of the thermal barrier coating and its preparation method, thermal barrier coating workpiece, and aviation component of the present application in conjunction with specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0039] In this application, "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0040] When a numerical range is disclosed herein, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. Unless otherwise specified or there is a contradiction, the terms or phrases used herein have the following meanings:

[0042] In the present application, "plurality", "multiple", "multiple times", "plurality", etc., unless otherwise specified, refer to a number greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0043] In this application, in the "first aspect", "second aspect", "third aspect", "fourth aspect", etc., the terms "first", "second", "third", "fourth", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0044] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0045] In the present application, references to “combinations thereof”, “any combination thereof”, “any combination thereof”, etc. include all suitable combinations of any two or more of the listed items.

[0046] In this application, the “suitable” mentioned in “suitable combination”, “suitable method”, “any suitable method”, etc. shall be based on the ability to implement the technical solution of this application, solve the technical problems of this application, and achieve the expected technical effects of this application.

[0047] In the present application, the terms “preferred”, “better”, “more preferred” and “suitable” are only used to describe implementation methods or examples with better effects, and it should be understood that they do not constitute limitations on the scope of protection of the present application.

[0048] In the present application, the terms “further”, “furthermore”, “particularly”, etc. are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present application.

[0049] In this application, "optionally", "optional" and "optional" refer to optional, that is, to any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0050] In the present application, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the optional numerical distribution is considered continuous within the above numerical interval, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical range, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers within the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints. In this article, it is equivalent to directly listing each integer, such as t is an integer selected from 1 to 10, indicating that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. In addition, when multiple ranges are provided to describe features or characteristics, these ranges can be combined. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges included therein.

[0051] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0052] In the present application, the percentage content, unless otherwise specified, refers to mass percentage for solid-liquid mixing and solid-solid mixing, and volume percentage for liquid-liquid mixing.

[0053] In this application, when it comes to percentage concentration, unless otherwise specified, it refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.

[0054] At present, the process parameters generally involved in the method of preparing metal thermal insulation layers by plasma physical vapor deposition include: current of 1800A~2000A, power of 100KW~120KW, and temperature of 900℃. This method requires a higher jet temperature, so the amount of He gas used will also increase, thereby increasing the spraying cost. In addition, the component that generates plasma in the plasma physical vapor deposition equipment is mainly the spray gun. Since the power and current used in the traditional preparation method are relatively high, a high voltage needs to be applied between the electrodes when the spray gun is working to ionize the gas to form plasma. However, the application of high voltage will cause the electrode to ablate faster, requiring additional replacement costs.

[0055] Based on this, see Figure 1 In a first aspect of the present application, a method for preparing a thermal barrier coating is provided, comprising the following steps:

[0056] S10, providing a substrate, and preparing a metal bonding layer on the surface of the substrate.

[0057] S20, preparing a ceramic heat-insulating layer on the surface of the metal bonding layer facing away from the substrate by using a plasma physical vapor deposition method.

[0058] Among them, in step S20, the preparation process parameters of the ceramic thermal insulation layer include: Ar gas flow rate is 10L / min~30L / min, He gas flow rate is 40L / min~50L / min, current is 1000A~1400A, power is 30KW~50KW, the temperature of the substrate is 600℃~800℃, and the working gas pressure is 2mbar~5mbar.

[0059] In the preparation process parameters of the ceramic thermal insulation layer provided in the present application, the amount of Ar gas and He gas used, the current and the power are further reduced by adjusting the working gas pressure and the substrate temperature, so as to realize physical vapor deposition at low power. At the same time, the preparation process parameters can also prepare a ceramic thermal insulation layer with a high gas phase content, thereby giving the thermal barrier coating a more excellent thermal insulation performance and thermal shock resistance.

[0060] Specifically, among the above process parameters, Ar gas is used as an inert gas, and its flow rate in the plasma physical vapor deposition process is 10L / min~30L / min, which can help stabilize the plasma and adjust the concentration of active substances in the plasma, thereby controlling the deposition rate of the ceramic thermal insulation layer to form a uniform ceramic thermal insulation layer. For example, the Ar gas flow rate includes but is not limited to 10L / min, 12L / min, 14L / min, 16L / min, 18L / min, 20L / min, 22L / min, 24L / min, 26L / min, 28L / min or 30L / min, or within the range formed by any two of the above point values ​​as endpoint values.

[0061] He gas has good thermal conductivity, and the present application limits the He gas flow rate to 40L / min~50L / min. Within this range, He gas can effectively transfer the heat generated by the plasma to the substrate surface, making the substrate temperature more uniform. At the same time, He gas can also increase the activity of the plasma, making the deposited ceramic particles smaller and more uniform. The present application limits the gas flow rates of He gas and Ar gas, and the two cooperate with each other to optimize the composition of the plasma and promote the densification of the ceramic thermal insulation layer. By way of example, the He gas flow rate includes but is not limited to 40L / min, 42 L / min, 44 L / min, 46 L / min, 48 L / min or 50L / min, or within the range formed by any two of the above point values ​​as endpoint values.

[0062] In the process parameters of the ceramic thermal insulation layer of the present application, the current is 1000A~1400A and the power is 30KW~50KW. Due to the coordination of other process parameters, the present application limits the current and power within the above-mentioned lower range, which can provide sufficient energy to fully evaporate and ionize the ceramic source, and at the same time enable the ceramic particles to be deposited at a suitable speed to form a dense and uniform microstructure. For example, the current value includes but is not limited to 1000A, 1050A, 1100A, 1150A, 1200A, 1250A, 1300A, 1350A or 1400A. The power value includes but is not limited to 30 KW, 32 KW, 34 KW, 36 KW, 38 KW, 40 KW, 42 KW, 45 KW, 48 KW or 50 KW, or any two of the above point values ​​as the range of endpoint values.

[0063] The substrate temperature of 600°C to 800°C can provide a suitable thermal environment for the deposition of the ceramic thermal insulation layer, making it easier for the ceramic material to adsorb, diffuse and react on the substrate surface. For example, the substrate temperature includes but is not limited to 600°C, 620°C, 650°C, 680°C, 700°C, 720°C, 750°C, 780°C or 800°C, or any two of the above points as endpoint values.

[0064] The working gas pressure has an important influence on the state of the plasma. In the gas pressure range of 2 mbar to 5 mbar, the plasma can maintain an appropriate density and activity between the spray gun and the substrate. This gas pressure range can prevent the plasma from over-diffusion or over-concentration, so that the active substances in the plasma can effectively interact with the ceramic source material and the substrate surface, thereby ensuring the deposition quality of the ceramic thermal insulation layer. For example, the working gas pressure includes but is not limited to 2 mbar, 2.2 mbar, 2.5 mbar, 2.7 mbar, 3 mbar, 3.2 mbar, 3.5 mbar, 3.8 mbar, 4 mbar, 4.2 mbar, 4.5 mbar, 4.8 mbar or 5 mbar, or in the range consisting of any two of the above point values ​​as endpoint values.

[0065] In one example, the preparation process parameters of the ceramic thermal insulation layer also include:

[0066] The powder feeding rate is 2g / L~10g / L, the powder feeding carrier gas Ar flow rate is 5L / min~9L / min, and the spraying distance is 400mm~800mm.

[0067] In the present application, the limitation of the powder feeding rate and the flow rate of the carrier gas Ar for feeding the powder can ensure the deposition efficiency of the ceramic thermal insulation layer. It can avoid the slow deposition speed caused by a slightly low powder feeding rate and a slightly low carrier gas flow rate, and can also avoid the uneven accumulation of powder caused by a little more powder reaching the surface of the metal bonding layer at the same time, which affects the quality of the ceramic thermal insulation layer.

[0068] For example, the powder feeding rate includes but is not limited to 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L or 10 g / L, or a range consisting of any two of the above point values ​​as endpoint values.

[0069] For example, the powder carrier gas Ar flow rate includes but is not limited to 5 L / min, 6 L / min, 7 L / min, 8 L / min or 9 L / min, or a range formed by any two of the above point values ​​as endpoint values.

[0070] In the present application, the spraying distance refers to the distance between the spray gun and the substrate. In the range of 400mm~800mm, the powder can be deposited on the substrate surface more evenly under the action of plasma. Then it can be avoided that the spraying distance is slightly close, and the powder is subjected to the excessive heat flow and impact force of the plasma, resulting in the disadvantage of increased surface roughness of the coating. It can also be avoided that the spraying distance is slightly far, and the powder loses too much energy during the spraying process, and cannot be fully melted and deposited, affecting the shortcomings of the compactness and uniformity of the coating. For example, the above-mentioned spraying distance includes but is not limited to 400mm, 450 mm, 500 mm, 550 mm, 600 mm, 650mm, 700 mm, 750 mm or 800 mm, or any two of the above-mentioned point values ​​are used as the range of the endpoint values.

[0071] In one example, the thickness of the ceramic thermal insulation layer is 50 μm to 500 μm.

[0072] The thickness of the ceramic insulation layer plays an important role in preventing the transfer of heat. In this application, the thickness of the ceramic insulation layer is limited to 50μm~500μm, so that when the heat passes through the ceramic insulation layer, it will be scattered and absorbed multiple times in the lattice, grain boundary and pore structures inside the ceramic material. At the same time, this thickness can also increase the heat propagation path, thereby reducing the heat transfer rate from high-temperature combustion gas to the substrate. By way of example, the thickness of the ceramic thermal insulation layer includes but is not limited to 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, 320 μm, 340 μm, 360 μm, 370 μm, 380 μm, 400 μm, 420 μm, 450 μm, 480 μm or 500 μm, or within the range formed by any two of the above point values ​​as endpoint values.

[0073] In one example, the ceramic thermal insulation layer has a columnar crystal structure.

[0074] In the present application, the ceramic thermal insulation layer is a columnar crystal structure, wherein there are a large number of grain boundaries in the columnar crystal structure, and the heat flow will be continuously scattered when crossing the grain boundaries, thereby effectively reducing the thermal conduction efficiency. In addition, the columnar crystal structure has good crystal directionality, which can better disperse thermal stress; when the ceramic thermal insulation layer is subjected to a sharp change in temperature and generates thermal stress, the interaction between the columnar crystals can disperse the stress to different grains and grain boundaries, reduce stress concentration, and improve the thermal shock resistance of the thermal barrier coating.

[0075] In one example, the powder used to prepare the ceramic thermal insulation layer is yttria-doped zirconium oxide.

[0076] Yttria doping can stabilize the crystal structure of zirconia, inhibit the occurrence of phase change, and make yttria-doped zirconia have lower thermal conductivity. And yttria-doped zirconia matches the thermal expansion coefficient of various metal substrates. It can expand and contract synchronously with the substrate material, reduce the thermal stress caused by the difference in thermal expansion coefficient, and thus reduce the risk of spalling of the ceramic insulation layer.

[0077] Furthermore, in the yttria-doped zirconia, the mass fraction of yttria is 6% to 8%.

[0078] In one example, the metal bonding layer includes one or more of MCrAlYSi, MCrAlY and PtAl; wherein M, when it appears each time, is independently one or more of Ni and Co.

[0079] The Al in MCrAlYSi and MCrAlY can form a chemical bond with the ceramic thermal insulation layer, while Ni and Co can form a metallurgical bond with the substrate, so that the bonding layer can play a good transition role between the ceramic thermal insulation layer and the substrate, and improve the bonding strength of the thermal barrier coating. PtAl alloy has a special intermetallic compound structure, in which the Pt element can improve the wettability of the interface, making it easier for the ceramic thermal insulation layer to adhere to the bonding layer; the Al element can interact with the components in the ceramic thermal insulation layer through chemical reactions to enhance the bonding effect. This good bonding can effectively prevent the ceramic thermal insulation layer from peeling off during high-temperature operation, so as to form a good interface bond between the ceramic thermal insulation layer and the substrate.

[0080] Illustratively, the metal bonding layer includes one or more of NiCrAlYSi, CoCrAlYSi, NiCrAlY, CoCrAlY and PtAl.

[0081] In one example, the thickness of the metal bonding layer is 30 μm to 200 μm. When the thickness of the metal bonding layer is within the above range, it can effectively play a bonding role between the ceramic thermal insulation layer and the substrate, thereby avoiding the disadvantage of uneven coverage of the substrate surface caused by a slightly thin metal bonding layer, which affects the bonding strength. For example, the thickness of the metal bonding layer includes but is not limited to 30 μm, 40 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, 320 μm, 340 μm, 360 μm, 370 μm, 380 μm, 400 μm, 420 μm, 450 μm, 480 μm or 500 μm, or any two of the above points are used as endpoint values.

[0082] In a second aspect of the present application, a thermal barrier coating is provided, comprising:

[0083] Metal bonding layer;

[0084] A ceramic heat-insulating layer is arranged on one side surface of the metal bonding layer, the ceramic heat-insulating layer is prepared by plasma physical vapor deposition, and the ceramic heat-insulating layer has a columnar crystal structure.

[0085] In thermal barrier coatings, the metal bonding layer and the ceramic insulation layer can work together to provide insulation. The metal bonding layer can reflect some heat to a certain extent and reduce the transfer of heat to the substrate. The ceramic insulation layer, as the main insulation part, has a columnar crystal structure that can effectively hinder heat conduction and has excellent thermal shock resistance. When the thermal barrier coating is applied to high-temperature components such as aircraft engines, it can significantly reduce the heat transfer from high-temperature combustion gas to metal components inside the engine, thereby improving the thermal efficiency of the engine and the service life of the components.

[0086] In one example, the metal bonding layer includes one or more of MCrAlY and PtAl; wherein M includes one or more of Ni and Co.

[0087] In one example, the thickness of the metal bonding layer is 30 μm to 200 μm.

[0088] In one example, the thickness of the ceramic insulation layer is 150 μm to 250 μm.

[0089] It can be understood that in the second aspect of the present application, the properties, thickness, etc. of the metal bonding layer and the ceramic insulation layer are similar to those of the first aspect of the present application, so they will not be repeated here.

[0090] See also Figure 3 According to a third aspect of the present application, a thermal barrier coating workpiece is provided, comprising a substrate 10 and the thermal barrier coating described in the second aspect of the present application, wherein the metal bonding layer 20 and the ceramic thermal insulation layer 30 in the thermal barrier coating are sequentially arranged on the surface of the substrate 10.

[0091] It can be understood that in the present application, the substrate is a metal substrate.

[0092] In the thermal barrier coating provided in the present application, the metal bonding layer and the metal heat insulation layer can be applied not only to the surface of a large-sized substrate, but also to a small-sized substrate. In one example, the size of the substrate is 5 mm to 200 mm.

[0093] In this application, "size" refers to the longest linear dimension of a substrate that can be measured in space.

[0094] In one example, the substrate is a nickel-based single crystal high temperature alloy. The thermal expansion coefficient of the nickel-based single crystal high temperature alloy can be well matched with the metal bonding layer and the ceramic insulation layer in the thermal barrier coating. During the temperature change process, this matching can reduce thermal stress and prevent the thermal barrier coating from peeling off.

[0095] At the same time, nickel-based single crystal high-temperature alloys have good chemical compatibility with the components in thermal barrier coatings (such as MCrAlY and PtAl in the metal bonding layer). At high temperatures, a certain chemical reaction can occur between the alloy matrix and the metal bonding layer to form a strong bonding interface.

[0096] In one example, the substrate includes a γ′ phase material containing nickel.

[0097] In a high temperature environment, the γ' phase material containing nickel can effectively hinder dislocation movement and resist creep deformation at high temperatures. For example, the matrix includes but is not limited to DD6 single crystal superalloy, IC10 single crystal superalloy and IC21 single crystal superalloy.

[0098] The following further specific examples are provided to explain the present application in detail. It should also be understood that the following examples are only used to further explain the present application and cannot be understood as limiting the scope of protection of the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present application belong to the scope of protection of the present application. The specific process parameters of the following embodiments are also only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not necessarily limited to the specific values ​​of the embodiments below.

[0099] Example 1

[0100] Embodiment 1 provides a thermal barrier coating and a preparation method, comprising the following steps:

[0101] (1) Providing a substrate, wherein the substrate is a Φ14*2mm DD6 single crystal high temperature alloy;

[0102] (2) preparing a metal bonding layer on the surface of the substrate, wherein the metal bonding layer is NiCrAlYSi and has a thickness of 40 μm;

[0103] (3) A ceramic thermal insulation layer is prepared on the surface of the metal bonding layer facing away from the substrate by plasma physical vapor deposition. The preparation process parameters of the ceramic thermal insulation layer include: Ar gas flow rate of 20 L / min, He gas flow rate of 40 L / min, current of 1400 A, power of 50 kW, substrate temperature of 800 °C, working gas pressure of 3 mbar, powder feeding rate of 5 g / L, powder carrier gas Ar flow rate of 5 L / min, and spraying distance of 600 mm. The powder is yttria-doped zirconia, and the thickness of the ceramic thermal insulation layer is 190 μm.

[0104] Example 2

[0105] Embodiment 2 provides a thermal barrier coating and a preparation method, comprising the following steps:

[0106] (1) Providing a substrate, wherein the substrate is a Φ14*2mm IC10 single crystal high temperature alloy;

[0107] (2) preparing a metal bonding layer on the surface of the substrate, wherein the metal bonding layer is PtAl and has a thickness of 50 μm;

[0108] (3) A ceramic thermal insulation layer is prepared on the surface of the metal bonding layer facing away from the substrate by plasma physical vapor deposition. The preparation process parameters of the ceramic thermal insulation layer include: Ar gas flow rate of 10 L / min, He gas flow rate of 50 L / min, current of 1000 A, power of 30 kW, substrate temperature of 600 °C, working gas pressure of 4 mbar, powder feeding rate of 3 g / L, powder carrier gas Ar flow rate of 5 L / min, and spraying distance of 400 mm. The powder is yttria-doped zirconia, and the thickness of the ceramic thermal insulation layer is 190 μm.

[0109] Example 3

[0110] Embodiment 3 provides a thermal barrier coating and a preparation method, comprising the following steps:

[0111] (1) Providing a substrate, wherein the substrate is a Φ14*2mm IC21 single crystal high temperature alloy;

[0112] (2) preparing a metal bonding layer on the surface of the substrate, wherein the metal bonding layer is PtAl and has a thickness of 30 μm;

[0113] (3) A ceramic thermal insulation layer is prepared on the surface of the metal bonding layer facing away from the substrate by plasma physical vapor deposition. The preparation process parameters of the ceramic thermal insulation layer include: Ar gas flow rate of 30 L / min, He gas flow rate of 40 L / min, current of 1200 A, power of 40 kW, substrate temperature of 700 °C, working gas pressure of 2 mbar, powder feeding rate of 2 g / L, powder carrier gas Ar flow rate of 9 L / min, and spraying distance of 800 mm. The powder is yttria-doped zirconia, and the thickness of the ceramic thermal insulation layer is 190 μm.

[0114] Comparative Example 1

[0115] Comparative Example 1 provides a thermal barrier coating and a preparation method, comprising the following steps:

[0116] (1) Providing a substrate, wherein the substrate is a Φ14*2mm IC21 single crystal high temperature alloy;

[0117] (2) preparing a metal bonding layer on the surface of the substrate, wherein the metal bonding layer is PtAl and has a thickness of 30 μm;

[0118] (3) A ceramic thermal insulation layer is prepared on the surface of the metal bonding layer facing away from the substrate by plasma physical vapor deposition. The preparation process parameters of the ceramic thermal insulation layer include: Ar gas flow rate of 30 L / min, He gas flow rate of 60 L / min, current of 1800 A, power of 60 kW, substrate temperature of 900 °C, working gas pressure of 2 mbar, powder feeding rate of 5 g / L, powder carrier gas Ar flow rate of 10 L / min, and spraying distance of 1200 mm. The thickness of the ceramic thermal insulation layer is 180 μm.

[0119] Figure 3~Figure 5 The microscopic morphology of the ceramic thermal insulation layer prepared in Example 1 of the present application at different magnifications; Figure 6~Figure 8 The microscopic morphology of the ceramic heat insulation layer prepared in Comparative Example 1 of the present application at different magnifications. Figure 3~Figure 5 It can be seen that the thickness of the ceramic thermal insulation layer prepared in Example 1 of the present application is about 190 μm, and the thermal insulation layer has fewer pores and cracks, and its structure is relatively dense, so it has good thermal insulation performance and mechanical strength. Figure 6~Figure 8 It can be seen that the ceramic thermal insulation layer prepared in Comparative Example 1 has more pores and cracks, and its structure is relatively loose, which will affect the thermal insulation performance and mechanical strength of the coating.

[0120] The bonding strength of the thermal barrier coating was tested with reference to the standard GB / T 8642-2002. The thermal insulation effect of the thermal barrier coating was tested with reference to the standard Q / 18A3046-2010 using gas thermal shock, and the difference between the surface temperature of the thermal barrier coating and the substrate temperature was tested, and the difference was recorded as the thermal insulation effect. The corresponding test results are shown in Table 1.

[0121] Table 1

[0122]

[0123] Furthermore, it can be seen from Table 1 that the thermal barrier coatings prepared in Examples 1 to 3 of the present application have better bonding strength and thermal insulation effects than those of Comparative Example 1.

[0124] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0125] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A method for preparing a thermal barrier coating, characterized in that: The following steps are involved: Providing a substrate, and preparing a metal bonding layer on the surface of the substrate; A ceramic heat-insulating layer is prepared on the surface of the metal bonding layer facing away from the substrate by using a plasma physical vapor deposition method; The preparation process parameters of the ceramic thermal insulation layer include: Ar gas flow rate of 10L / min~30L / min, He gas flow rate of 40L / min~50L / min, current of 1000A~1400A, power of 30KW~50KW, temperature of the substrate of 600℃~800℃, and working gas pressure of 2mbar~5mbar.

2. The method for preparing a thermal barrier coating according to claim 1, characterized in that: The preparation process parameters of the ceramic thermal insulation layer also include: The powder feeding rate is 2g / L~10g / L, the powder feeding carrier gas Ar flow rate is 5L / min~9L / min, and the spraying distance is 400mm~800mm.

3. The method for preparing a thermal barrier coating according to claim 1, characterized in that: The thickness of the ceramic heat insulation layer is 50 μm to 500 μm; and / or, The ceramic heat insulation layer is a columnar crystal structure.

4. The method for preparing a thermal barrier coating according to claim 1, characterized in that: The powder used to prepare the ceramic heat insulation layer is yttria-doped zirconium oxide.

5. The method for preparing a thermal barrier coating according to any one of claims 1 to 4, characterized in that: The metal bonding layer comprises one or more of MCrAlYSi, MCrAlY and PtAl; wherein M, when it appears each time, is independently one or more of Ni and Co; and / or, The thickness of the metal bonding layer is 30 μm to 200 μm.

6. A thermal barrier coating, characterized in that: include: Metal bonding layer; A ceramic heat-insulating layer is arranged on one side surface of the metal bonding layer, the ceramic heat-insulating layer is prepared by plasma physical vapor deposition, and the ceramic heat-insulating layer has a columnar crystal structure.

7. The thermal barrier coating according to claim 6, characterized in that: The thermal barrier coating has one or more of the following characteristics: (1) The metal bonding layer includes one or more of MCrAlY and PtAl; wherein M includes one or more of Ni and Co; (2) The thickness of the metal bonding layer is 30 μm to 200 μm; (3) The thickness of the ceramic thermal insulation layer is 150 μm to 250 μm.

8. A thermal barrier coating workpiece, characterized in that: It comprises a substrate and the thermal barrier coating according to claim 6 or 7, wherein the metal bonding layer and the ceramic thermal insulation layer in the thermal barrier coating are sequentially arranged on the surface of the substrate.

9. The thermal barrier coating workpiece according to claim 8, characterized in that: The substrate has one or more of the following characteristics: (1) The size of the substrate is 5 mm to 200 mm; (2) The substrate is a nickel-based single crystal high-temperature alloy; (3) The matrix includes a γ' phase material containing nickel.

10. An aviation component, characterized in that: A workpiece comprising the thermal barrier coating as claimed in claim 8 or 9.

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