Metal ceramic composite bonding layer and preparation method and application thereof

Abstract

The invention discloses a metal ceramic composite bonding layer and a preparation method and application thereof. Relates to the technical field of thermal barrier coatings. The metal ceramic composite bonding layer is prepared from the following raw material components: an aluminum-based MAX phase ceramic material and a high-temperature alloy material, the mass ratio of the high-temperature alloy material to the aluminum-based MAX-phase ceramic material is (3-2): 1; the high-temperature alloy material is an Al-containing Ni-based and / or Co-based alloy material. By adopting a composite system of an aluminum-based MAX-phase ceramic material and a high-temperature alloy material, a metal-ceramic composite bonding layer which cannot generate spinel oxide in a high-temperature oxidation environment is successfully constructed.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal barrier coatings, and in particular to a cermet composite bond coat and a preparation method and application thereof. Background Art

[0002] Thermal barrier coatings (TBCs), as an important high-temperature protection material, are widely used in high-temperature hot-end components of gas turbines and aeroengines to effectively prevent oxidation of the substrate metal material and increase the heat-receiving temperature of the hot-end components. These coatings can not only significantly improve the combustion efficiency of the engine but also extend the service life of the engine, especially playing a crucial role under working conditions in high-temperature and high-pressure environments. However, with the increase in the thrust-to-weight ratio of modern engines and the continuous enhancement of combustion efficiency, the working temperature of the hot-end components of engines and gas turbines is also increasing continuously, bringing a more severe working environment. Therefore, the high-temperature resistance and service life of existing thermal barrier coatings are facing unprecedented challenges. This makes the development of new thermal barrier coatings with higher high-temperature resistance and longer service life become a hot spot in current research and application.

[0003] Classical thermal barrier coatings usually consist of three parts: a ceramic top coat, a bond coat, and a thermally grown oxide (TGO) layer. The ceramic top coat, usually made of materials such as yttria-stabilized zirconia (YSZ), mainly plays a role in heat insulation; the bond coat, usually an MCrAlY (M = Ni, Co, NiCo) alloy containing nickel, cobalt, or nickel-cobalt alloy, has the function of high-temperature oxidation resistance; and the TGO layer is an alumina layer formed at the interface between the two layers due to high-temperature oxidation reaction. Ideally, the TGO layer should be composed of dense Al2O3 with a low oxygen diffusion coefficient, which can effectively prevent oxygen from diffusing to the substrate in a high-temperature environment, thereby protecting the substrate material from further oxidation and corrosion.

[0004] However, in practical applications, during the high-temperature oxidation process of traditional thermal barrier coatings, in addition to the formation of the expected Al2O3 protective layer, porous and brittle spinel oxides (usually the phase of (Ni,Cr)2O4) often form. The formation of spinel oxides is a harmful phase in the structure of thermal barrier coatings. Its presence not only affects the protective performance of the coating but also accelerates the failure of the coating. This failure mechanism is mainly reflected in two aspects: on the one hand, due to its brittle and porous structure, spinel oxides reduce the mechanical strength of the thermal barrier coating, resulting in the coating being more prone to cracking and spalling; on the other hand, the formation of spinel oxides exacerbates the thickness of the thermally grown oxide layer, further increasing the stress inside the coating and leading to the acceleration of coating failure.

[0005] The formation of spinel oxides is also closely related to the traditional plasma spraying process. During the preparation of the coating, the plasma spraying technology melts the powder material in a high-temperature flame and sprays it onto the substrate surface to form a coating. However, there are several potential problems in this process. First, due to the extremely high temperature of the plasma spraying flame, which can usually reach several thousand degrees Celsius, the aluminum element in the MCrAlY powder is prone to react with oxygen during spraying to form a large amount of Al2O3. Although this phenomenon can effectively improve the oxidation resistance of the coating, before the coating preparation, a large amount of aluminum element in the bond coat may be consumed, resulting in a significant reduction in the aluminum content of the bond coat, thus affecting its subsequent oxidation reaction ability and the ability to form a protective layer.

[0006] As the coating is used in a high-temperature environment, the thermal cycle oxidation effect gradually appears. Under high-temperature conditions, the coating will undergo multiple heating and cooling cycles, and this thermal cycle oxidation will lead to insufficient supply of aluminum element inside the bond coat. The shortage of aluminum element exacerbates the outward diffusion of elements such as Ni and Cr, which react with oxygen to form spinel oxides ((Ni,Cr)2O4), replacing the formation of Al2O3. Since the formation rate of spinel oxides is faster than that of alumina, this process causes the thickness of the thermally grown oxide layer to increase rapidly, and the stress inside the coating also increases accordingly. These stresses will cause the coating to crack, spall, etc., thus accelerating the failure of the thermal barrier coating.

[0007] In addition, the formation of spinel oxides is also closely related to the material composition, preparation process, and service environment of the bond coat in the coating. Especially during the high-temperature oxidation of the bond coat, the element diffusion and phase transformation mechanisms are the key factors determining the coating performance. The flow of elements inside the bond coat and the penetration of oxygen play a decisive role in the growth of the TGO layer and the stability of the bond coat. Research shows that optimizing the composition of the bond coat material and improving the microstructure of the bond coat can effectively improve the oxidation resistance, thermal crack resistance, and mechanical properties, thereby increasing the service life of the thermal barrier coating.

[0008] Based on this, it is urgent to develop a new type of bond coat to improve the life and high-temperature resistance of the thermal barrier coating. Summary of the Invention

[0009] The purpose of the present invention is to provide a cermet composite bond coat that does not generate spinel oxides during high-temperature oxidation and has a long thermal cycle resistance life.

[0010] The first aspect of the present invention lies in:

[0011] To provide a cermet composite bond coat.

[0012] The second aspect of the present invention lies in:

[0013] Provide a method for preparing a cermet composite bonding layer.

[0014] The third aspect of the present invention lies in:

[0015] The application of the cermet composite bonding layer.

[0016] Specifically, the technical solution adopted according to the first aspect of the present invention is:

[0017] A cermet composite bonding layer, the raw materials comprising the following components:

[0018] Al-based MAX phase ceramic material and superalloy material;

[0019] The mass ratio of the superalloy material to the Al-based MAX phase ceramic material is 4 - 2:1;

[0020] The superalloy material is an Al-containing Ni-based and / or Co-based alloy material.

[0021] According to the embodiments of the present invention, at least one of the following advantages or beneficial effects is achieved by one of the technical solutions in the technical solutions:

[0022] By adopting a composite system of Al-based MAX phase ceramic material and superalloy material, the present invention successfully constructs a metal-ceramic composite bonding layer that does not generate spinel oxides in a high-temperature oxidation environment. This design breaks through the technical bottleneck of traditional bonding layers. The present invention adopts an Al-containing Ni-based and / or Co-based alloy material, which can in-situ generate a continuous and dense Al2O3 barrier layer during high-temperature oxidation, effectively inhibiting the diffusion of oxygen ions; while the superalloy material, as the main material of the bonding layer, ensures the good high-temperature oxidation resistance and corrosion resistance of the bonding layer.

[0023] The innovative synergistic effect of the Al-based MAX phase ceramic material and the superalloy material also solves the performance contradiction of single materials: Although the superalloy material has good high-temperature oxidation resistance and corrosion resistance, due to the influence of the alloy brittleness of the superalloy material, its Al element content is relatively low, and it is difficult to continuously provide sufficient Al elements to form an Al2O3 protective film, thus limiting the service life of the system; while a single MAX phase ceramic material as the bonding layer cannot meet the mechanical property requirements of the bonding layer. Based on this, the synergy of the Al-based MAX phase ceramic material and the superalloy material, the Al-based MAX phase ceramic material provides a continuous Al source for the formation of Al2O3, and the superalloy material provides sufficient mechanical properties for the bonding layer;

[0024] In addition, when doping the aluminum-based MAX-phase ceramic material, an appropriate amount is required to ensure that the thermally grown oxide formed by the oxidation of the cermet composite bonding layer during the high-temperature process is continuous and has a relatively thin thickness, reducing the thermal stress generated during the thermal shock process, improving the high-temperature oxidation resistance of the bonding layer, and ensuring its effective protective effect in a high-temperature environment.

[0025] According to an embodiment of the present invention, the mass ratio of the superalloy material to the aluminum-based MAX-phase ceramic material is 4:1, or 3:1, or 2:1. Preferably, it is 3:1.

[0026] According to an embodiment of the present invention, the Al-containing Ni-based and / or Co-based alloy material includes at least one of NiCrAlY, NiCoCrAlY, and NiCoCrAlTaY.

[0027] According to an embodiment of the present invention, in the raw material components of the cermet composite bonding layer, the mass percentage content of the aluminum-based MAX-phase ceramic material is 15% - 85%.

[0028] According to an embodiment of the present invention, in the raw material components of the cermet composite bonding layer, the mass percentage content of the aluminum-based MAX-phase ceramic material is 15 - 45%.

[0029] According to an embodiment of the present invention, in the raw material components of the cermet composite bonding layer, the mass percentage content of the aluminum-based MAX-phase ceramic material is 20 - 30%.

[0030] According to an embodiment of the present invention, in the raw material components of the cermet composite bonding layer, the mass percentage content of the superalloy material is 15% - 85%.

[0031] According to an embodiment of the present invention, in the raw material components of the cermet composite bonding layer, the mass percentage content of the superalloy material is 55% - 85%.

[0032] According to an embodiment of the present invention, in the raw material components of the cermet composite bonding layer, the mass percentage content of the superalloy material is 70% - 80%.

[0033] According to an embodiment of the present invention, the aluminum-based MAX-phase ceramic material includes at least one of Cr2AlC and Ti2AlC. Preferably, the aluminum-based MAX-phase ceramic material includes Cr2AlC. Due to its unique layered structure, the Cr2AlC material can in-situ generate a more continuous and dense Al2O3 barrier layer during the high-temperature oxidation process, effectively inhibiting the diffusion of oxygen ions.

[0034] According to an embodiment of the present invention, the shape of the aluminum-based MAX-phase ceramic material is irregular.

[0035] According to an embodiment of the present invention, the particle size of the aluminum-based MAX phase ceramic material is 1 μm to 100 μm.

[0036] According to an embodiment of the present invention, the particle size of the aluminum-based MAX phase ceramic material is 5 μm to 100 μm.

[0037] According to an embodiment of the present invention, the particle size of the aluminum-based MAX phase ceramic material is 5 μm to 20 μm.

[0038] According to an embodiment of the present invention, the shape of the superalloy material is spherical or quasi-spherical. Preferably, the shape of the superalloy material is spherical.

[0039] According to an embodiment of the present invention, the particle size of the superalloy material is 1 μm to 100 μm.

[0040] According to an embodiment of the present invention, the particle size of the superalloy material is 5 μm to 100 μm.

[0041] According to an embodiment of the present invention, the particle size of the superalloy material is 15 μm to 45 μm.

[0042] According to an embodiment of the present invention, the mixed powder of the aluminum-based MAX phase ceramic material and the superalloy material is used to prepare the cermet composite bonding layer through a supersonic spraying process.

[0043] Specifically, the technical solution adopted in the second aspect of the present invention is as follows:

[0044] A method for preparing the cermet composite bonding layer includes the following steps:

[0045] Mix the aluminum-based MAX phase ceramic material and the superalloy material to obtain a metal-ceramic mixed powder;

[0046] Spray the metal-ceramic mixed powder on the surface of the substrate through a supersonic spraying process to form the cermet composite bonding layer.

[0047] According to the embodiment of the present invention, at least one of the following advantages or beneficial effects is achieved by one of the technical solutions in the technical solution:

[0048] The present invention uses a supersonic spraying process to prepare a metal-ceramic composite coating, effectively solving the oxidation problem in traditional spraying techniques. During the preparation process, the metal-ceramic mixed powder impacts the surface of the substrate at a high speed of 400-600 m / s through supersonic spraying. Among them, the superalloy material undergoes plastic deformation in a softened state and forms a high-strength metallurgical bond with the substrate. At the same time, the aluminum-based MAX phase ceramic material is co-deposited to form a composite coating structure. Compared with the limitations of traditional plasma spraying (the flame temperature > 6000 °C is likely to cause oxidation of Al elements), the method of the present invention uses a supersonic spraying process, and the mechanical interlocking effect generated by the impact of supersonic particles can significantly improve the bonding strength between the coating and the substrate.

[0049] According to an embodiment of the present invention, the supersonic spraying process includes at least one of supersonic air-assisted combustion flame spraying and supersonic oxygen-assisted combustion flame spraying.

[0050] According to an embodiment of the present invention, the speed of the metal-ceramic mixed powder when sprayed on the surface of the substrate is 300-600 m / s.

[0051] According to an embodiment of the present invention, the speed of the metal-ceramic mixed powder when sprayed on the surface of the substrate is 400-600 m / s.

[0052] According to an embodiment of the present invention, the speed of the metal-ceramic mixed powder when sprayed on the surface of the substrate is 300-400 m / s.

[0053] According to an embodiment of the present invention, in the supersonic spraying process, the flame temperature during spraying < 2000 °C.

[0054] According to an embodiment of the present invention, the method of the present invention significantly reduces the heat input by controlling the flame temperature (typical value < 2000 °C), and cooperates with the powder flying speed of 300-400 m / s to shorten the high-temperature exposure time, double-guaranteeing the chemical stability of the aluminum-based MAX phase ceramic material and the Al element in the superalloy material, and avoiding the formation of Al2O3 oxidation products.

[0055] According to an embodiment of the present invention, the method of mixing the aluminum-based MAX phase ceramic material and the superalloy material includes mechanical ball milling.

[0056] According to an embodiment of the present invention, the mechanical ball milling is carried out in a protective atmosphere. Preferably, the mechanical ball milling is carried out in an argon atmosphere.

[0057] According to an embodiment of the present invention, the mechanical ball milling is carried out under the condition that the rotational speed of the ball mill is 100 r / min to 120 r / min, and 2 to 3 cycles are carried out. The purpose of mechanical ball milling is to make the micron-scale superalloy material and the micron-scale aluminum-based MAX-phase ceramic material reach physical mixing uniformity. The rotational speed of the ball mill should not be too fast and the ball milling time should not be too long to avoid changing the morphology and size of the powder.

[0058] According to an embodiment of the present invention, the substrate includes a cobalt-based superalloy substrate.

[0059] Another aspect of the present invention also provides a thermal barrier coating. It includes the cermet composite bonding layer as described in the embodiment of the first aspect above. Since this application adopts all the technical solutions of the above cermet composite bonding layer, it has at least all the beneficial effects brought by the technical solutions of the above embodiments.

[0060] According to an embodiment of the present invention, the thermal barrier coating includes a substrate, the cermet composite bonding layer and a ceramic surface layer. The thermal barrier coating includes the cermet composite bonding layer. The composite system of aluminum-based MAX-phase ceramic material and superalloy material in the cermet composite bonding layer ensures that a continuous and dense Al2O3 protective film can be formed for a long time in a high-temperature environment, preventing oxygen from diffusing into the ceramic surface layer and the interior of the substrate to cause oxidation, and reducing the outward diffusion of elements such as Ni and Cr to the surface to form spinel oxides, so as to better and more durably maintain the structural integrity of the thermal barrier coating and extend the service life of the coating.

[0061] Another aspect of the present invention also provides an aeroengine, including the thermal barrier coating.

[0062] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will be obvious from the specification or understood by implementing the present invention. Description of the Drawings

[0063] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0064] Figure 1 It is a schematic structural diagram of the thermal barrier coating in Embodiment 1.

[0065] Figure 2 It is a graph of the thermal shock life test results of the thermal barrier coatings of Comparative Examples 1-3 and Embodiment 1.

[0066] Figure 3 It is an organizational structure diagram of the cross-section of the bonding layer of the thermal barrier coating in Comparative Example 1.

[0067] Figure 4It is an organizational structure diagram of the cross-section of the metal-ceramic composite bonding layer in the thermal barrier coating of Example 1.

[0068] Figure 5 It is an organizational structure diagram of the cross-section of the metal-ceramic composite bonding layer in the thermal barrier coating of Comparative Example 2.

[0069] Figure 6 It is an organizational structure diagram of the cross-section of the metal-ceramic composite bonding layer in the thermal barrier coating of Comparative Example 3.

[0070] Figure 7 It is an SEM image of the cross-section of the thermal barrier coating of Comparative Example 1 after cyclic oxidation at 1100 °C for 17 days.

[0071] Figure 8 It is an SEM image of the cross-section of the thermal barrier coating of Example 1 after cyclic oxidation at 1100 °C for 53 days.

[0072] Figure 9 It is an SEM image of the cross-section of the thermal barrier coating of Comparative Example 2 after cyclic oxidation at 1100 °C for 5 days.

[0073] Figure 10 It is an SEM image of the cross-section of the thermal barrier coating of Comparative Example 3 after cyclic oxidation at 1100 °C for 3 days

[0074] Reference numerals:

[0075] 10 - CH5188 cobalt-based superalloy substrate; 20 - metal-ceramic composite bonding layer; 30 - ceramic surface layer. Detailed implementation manners

[0076] The embodiments of the present invention will be described in detail below. The same or similar reference numerals throughout the embodiments represent the same or similar elements or elements having the same or similar functions. The embodiments described below are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0077] The terms "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain cases. However, in the same or other cases, other embodiments may also be preferred. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not available, nor is it intended to exclude other embodiments from the scope of the present invention.

[0078] When a numerical range is disclosed herein, the above range is considered continuous and includes the minimum and maximum values of the range, as well as every value therebetween. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0079] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of the present invention.

[0080] The reagents, methods, and equipment used in the present invention, unless otherwise specified, are all conventional reagents, methods, and equipment in this technical field.

[0081] Example 1

[0082] A cermet composite bonding layer 20, the raw materials comprising the following components:

[0083] Irregularly shaped aluminum-based MAX phase ceramic materials with a particle size of 5 μm to 20 μm and spherical superalloy materials with a particle size of 15 μm to 45 μm;

[0084] The mass ratio of the above-mentioned superalloy material to the above-mentioned aluminum-based MAX phase ceramic material is 3:1;

[0085] The above-mentioned superalloy material is NiCrAlY;

[0086] The above-mentioned aluminum-based MAX phase ceramic material is Cr2AlC;

[0087] A method for preparing the above-mentioned cermet composite bonding layer 20, comprising the following steps:

[0088] Spherical NiCrAlY alloy powder with a particle size of 15 μm to 45 μm and irregularly shaped Cr2AlC with a particle size of 5 μm to 20 μm are added to a ball mill according to a mass ratio of 3:1, and the ball mill is controlled to rotate at 120 r / min for 3 cycles in an argon atmosphere to obtain a metal-ceramic mixed powder;

[0089] The surface of the GH5188 cobalt-based superalloy substrate is sandblasted and ultrasonically cleaned with acetone, and then the metal-ceramic mixed powder is sprayed on the substrate surface by a high-velocity air-fuel (HVAF) process to form a cermet composite bonding layer 20.

[0090] A thermal barrier coating, the structural schematic diagram is as Figure 1 shown, including a GH5188 cobalt-based superalloy substrate 10, the above-mentioned cermet composite bonding layer 20 and a ceramic surface layer 30.

[0091] Among them, the ceramic surface layer 30 is prepared by the following method:

[0092] The yttria-stabilized zirconia 8YSZ powder with a particle size of 15 μm to 45 μm (the mass percentage content of yttria is 8%) is sprayed on the surface of the cermet composite bonding layer 20 by a plasma spraying process, and the ceramic surface layer 30 is obtained.

[0093] Comparative Example 1

[0094] A thermal barrier coating, including a GH5188 cobalt-based superalloy substrate, a metal bonding layer and a ceramic surface layer.

[0095] A method for preparing a thermal barrier coating includes the following steps:

[0096] The surface of the GH5188-based superalloy substrate is subjected to sandblasting and ultrasonic cleaning with acetone, and then the spherical NiCrAlY alloy powder with a particle size of 15 μm to 45 μm is sprayed on the surface of the GH5188 cobalt-based substrate by a high-velocity air-fuel (HVAF) spraying process to obtain a metal bonding layer;

[0097] The yttria-stabilized zirconia 8YSZ powder with a particle size of 15 μm to 45 μm (the mass percentage content of yttria is 8%) is sprayed on the surface of the metal bonding layer by a plasma spraying process to form a ceramic surface layer, and the thermal barrier coating is obtained.

[0098] Comparative Example 2

[0099] The difference between Comparative Example 2 and Example 1 is that: the mass ratio of the superalloy material to the above-mentioned aluminum-based MAX phase ceramic material is different. In Example 1, it is 3:1, and in Comparative Example 2, it is 1:1.

[0100] A cermet composite bonding layer, the raw materials include the following components:

[0101] Irregularly shaped aluminum-based MAX phase ceramic materials with a particle size of 5 μm to 20 μm and spherical superalloy materials with a particle size of 15 μm to 45 μm;

[0102] The mass ratio of the above-mentioned superalloy material to the above-mentioned aluminum-based MAX phase ceramic material is 1:1;

[0103] The above-mentioned superalloy material is NiCrAlY;

[0104] The above-mentioned aluminum-based MAX phase ceramic material is Cr2AlC;

[0105] A method for preparing the above-mentioned cermet composite bonding layer, comprising the following steps:

[0106] Spherical NiCrAlY alloy powder with a particle size of 15 μm to 45 μm and irregularly shaped Cr2AlC with a particle size of 5 μm to 20 μm are added to a ball mill in a mass ratio of 1:1, and the rotation speed of the ball mill is controlled at 120 r / min in an argon atmosphere for 3 cycles of ball milling to obtain a metal-ceramic mixed powder;

[0107] The surface of the GH5188 cobalt-based superalloy substrate is subjected to sandblasting and ultrasonic cleaning with acetone, and then the metal-ceramic mixed powder is sprayed on the substrate surface by a high-velocity air-fuel (HVAF) spraying process to form a metal-ceramic composite bonding layer.

[0108] A thermal barrier coating, comprising a GH5188 cobalt-based superalloy substrate, the above-mentioned cermet composite bonding layer, and a ceramic surface layer.

[0109] Among them, the ceramic surface layer is prepared by the following method:

[0110] 8YSZ powder of yttria-stabilized zirconia with a particle size of 15 μm to 45 μm (the mass percentage content of yttria is 8%) is sprayed on the surface of the metal-ceramic composite bonding layer by a plasma spraying process to obtain the ceramic surface layer.

[0111] Comparative Example 3

[0112] The difference between Comparative Example 3 and Example 1 lies in that the mass ratio of the superalloy material to the above-mentioned aluminum-based MAX phase ceramic material is different. In Example 1, it is 3:1, and in Comparative Example 3, it is 1:3.

[0113] A cermet composite bonding layer, the raw materials of which include the following components:

[0114] Irregularly shaped aluminum-based MAX phase ceramic material with a particle size of 5 μm to 20 μm and spherical superalloy material with a particle size of 15 μm to 45 μm;

[0115] The mass ratio of the above-mentioned superalloy material to the above-mentioned aluminum-based MAX phase ceramic material is 1:3;

[0116] The above-mentioned superalloy material is NiCrAlY;

[0117] The above-mentioned aluminum-based MAX phase ceramic material is Cr2AlC.

[0118] A method for preparing the above-mentioned cermet composite bonding layer, comprising the following steps:

[0119] Spherical NiCrAlY alloy powder with a particle size of 15 μm to 45 μm and irregularly shaped Cr2AlC with a particle size of 5 μm to 20 μm were added to a ball mill in a mass ratio of 1:3. The ball mill was controlled to rotate at 120 r / min under an argon atmosphere for 3 cycles of ball milling to obtain a metal-ceramic hybrid powder;

[0120] The surface of the GH5188 cobalt-based superalloy substrate was sandblasted and ultrasonically cleaned with acetone, and then the metal-ceramic hybrid powder was sprayed on the substrate surface by the high-velocity air fuel (HVAF) process to form a metal-ceramic composite bonding layer.

[0121] A thermal barrier coating includes a GH5188 cobalt-based superalloy substrate, the above-mentioned metal-ceramic composite bonding layer, and a ceramic surface layer.

[0122] Among them, the ceramic surface layer was prepared by the following method:

[0123] Yttria-stabilized zirconia 8YSZ powder with a particle size of 15 μm to 45 μm (the mass percentage content of yttria is 8%) was sprayed on the surface of the metal-ceramic composite bonding layer by the plasma spraying process to obtain the ceramic surface layer.

[0124] Performance test:

[0125] The thermal barrier coatings of Comparative Examples 1-3 and Example 1 were respectively placed in a muffle furnace, heated to 1100 °C and held for 23 h, then taken out and cooled in air for 1 h as one cycle (1 day), and cyclic tests were carried out until obvious spalling occurred on the thermal barrier coating. The number of cycles was recorded (to avoid the contingency of test results, 3 specimens were used for each test sample and the average value was taken to ensure the accuracy of the test results). The thermal shock life test results obtained are as Figure 2 shown. Figure 2 In the table, thermal cycling lifetime is the thermal cycle life. The thermal cycle life of the thermal barrier coating in the comparative example is 17 days, the thermal cycle life of the thermal barrier coating in Example 1 is 53 days, the thermal cycle life of the thermal barrier coating in Comparative Example 2 is 3 days, and the thermal cycle life of the thermal barrier coating in Comparative Example 3 is 5 days.

[0126] From Figure 2 it can be seen that: compared with the comparative examples, the thermal cycle life of the thermal barrier coating prepared by the high-velocity air fuel spraying process with metal-ceramic composite powder to form a metal-ceramic composite bonding layer in Example 1 is significantly improved.

[0127] The cross-sectional microstructure diagrams of the bonding layers in the thermal barrier coatings of Comparative Examples 1-3 and Example 1 (observed by scanning electron microscopy, (SEM, GeminiSEM300, Carl Zeiss SMT, Ltd., UK) are as Figures 3 to 6 shown.

[0128] It can be seen from Figure 3 that: The pure NiCrAlY metal bond coat prepared by the high-velocity oxy-fuel spraying process in Comparative Example 1 has good bonding with the substrate, and the coating texture is uniform.

[0129] It can be seen from Figure 4 that: In Example 1, a metal-ceramic composite bond coat was prepared by the high-velocity oxy-fuel spraying process. The ceramic particles in the prepared metal-ceramic composite bond coat are evenly distributed, and the thermal cycle life of the final thermal barrier coating is greatly improved compared with that of Comparative Example 1.

[0130] It can be seen from Figure 5 that: In Comparative Example 2, a metal-ceramic composite bond coat was prepared by the high-velocity oxy-fuel spraying process. The ceramic particles in the prepared metal-ceramic composite bond coat are evenly distributed. However, due to the relatively large content of ceramic particles, the porosity inside the bond coat is relatively high, and the thermal cycle life of the final thermal barrier coating is reduced compared with that of Comparative Example 1.

[0131] It can be seen from Figure 6 that: In Comparative Example 3, a metal-ceramic composite bond coat was prepared by the high-velocity oxy-fuel spraying process. The ceramic particles in the prepared metal-ceramic composite bond coat are evenly distributed. The Cr2AlC ceramic particles become the main phase, the porosity inside the bond coat is relatively high and it shows brittleness, and it is prone to fracture. The thermal cycle life of the final thermal barrier coating is greatly reduced compared with that of Comparative Example 1.

[0132] The scanning electron microscope (SEM) images of the cross-sections of the thermal barrier coatings of Comparative Examples 1-3 and Example 1 after cyclic oxidation at 1100 °C for 17 days, 53 days, 5 days and 3 days respectively are as Figures 7 to 10 shown.

[0133] It can be seen from Figure 7 that: The thermally grown oxide formed by the oxidation of the thermal barrier coating in Comparative Example 1 during the high-temperature process is thick and spinel oxide is formed, and the antioxidant effect is poor.

[0134] It can be seen from Figure 8 that: The thermally grown oxide formed by the oxidation of the thermal barrier coating in Example 1 during the high-temperature process is continuous and relatively thin, which greatly reduces the thermal stress generated during the thermal shock process. There are no dispersed oxides and no spinel oxides formed inside the coating, and the antioxidant effect is greatly improved.

[0135] It can be seen from Figure 9 that: In the thermal barrier coating of Comparative Example 2, oxidation occurs at both the upper and lower interfaces of the bond coat during the high-temperature process, resulting in the formation of oxides at the interface between the bond coat and the substrate, which reduces the coating adhesion and causes the coating to fail prematurely, and the life is greatly reduced.

[0136] It can be seen from Figure 10It can be seen that the porosity inside the bond coat of the thermal barrier coating in Comparative Example 3 is too high. During high-temperature oxidation, oxidation occurs inside the bond coat, and fractures are extremely likely to occur inside the coating, greatly reducing the service life of the coating.

[0137] In summary, it can be seen that the metal-ceramic composite bond coat in Example 1 of the present invention improves the problem of insufficient supply of Al element existing in the metal bond coat of the traditional thermal barrier coating. Moreover, the metal-ceramic composite bond coat in the present invention changes the oxidation behavior of the thermal barrier coating, can form a continuous, dense and thin Al2O3 thermally grown oxide, inhibits the formation of spinel oxide, reduces the thermal stress of the thermal barrier coating, improves the stability of the thermal barrier coating, and significantly improves the oxidation resistance and thermal cycling life of the thermal barrier coating.

[0138] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent transformation made by using the content of the specification of the present invention, or directly or indirectly applied in the related technical field, shall be equally included in the patent protection scope of the present invention.

Claims

1. A metal-ceramic composite bonding layer, characterized in that: The raw materials include the following components: Aluminum-based MAX phase ceramic materials and high-temperature alloy materials; The mass ratio of the high temperature alloy material to the aluminum-based MAX phase ceramic material is 3-2:1; The high temperature alloy material is a Ni-based and / or Co-based alloy material containing Al.

2. The metal-ceramic composite bonding layer according to claim 1, characterized in that: The aluminum-based MAX phase ceramic material includes at least one of Cr2AlC and Ti2AlC.

3. The metal-ceramic composite bonding layer according to claim 1, characterized in that: The Al-containing Ni-based and / or Co-based alloy material includes at least one of NiCrAlY, NiCoCrAlY, and NiCoCrAlTaY.

4. The metal-ceramic composite bonding layer according to claim 1, characterized in that: The particle size of the aluminum-based MAX phase ceramic material is 1 μm to 100 μm; the particle size of the high-temperature alloy material is 1 μm to 100 μm.

5. A method for preparing a metal-ceramic composite bonding layer as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: Mixing aluminum-based MAX phase ceramic material and high temperature alloy material to obtain metal-ceramic mixed powder; The metal-ceramic mixed powder is sprayed on the surface of the substrate through a supersonic spraying process to form the metal-ceramic composite bonding layer.

6. The method according to claim 5, characterized in that: The supersonic spraying process includes at least one of supersonic air-assisted flame spraying and supersonic oxygen-assisted flame spraying.

7. The method according to claim 5, characterized in that: The speed of the metal-ceramic mixed powder when spraying on the substrate surface is 300-600 m / s.

8. The method according to claim 5, characterized in that: In the supersonic spraying process, the flame temperature during the spraying process is less than 2000°C.

9. A thermal barrier coating, characterized in that: It comprises a substrate, a bonding layer and a ceramic surface layer stacked in sequence, wherein the bonding layer comprises a metal-ceramic composite bonding layer as described in any one of claims 1 to 4 or a metal-ceramic composite bonding layer prepared by the method as described in any one of claims 5 to 9.

10. An aircraft engine, characterized in that: Comprising the thermal barrier coating according to claim 9.

Images