A self-healing ytterium silicate-based environmental barrier coating and a method of making the same

Abstract

The application relates to the technical field of thermal protection coating materials, and discloses a self-healing ytterbia-based environmental barrier coating and a preparation method thereof. The preparation method of the self-healing ytterbia-based environmental barrier coating comprises the following steps: adding ytterbium-aluminum-silicon microcrystalline glass self-healing agent and ytterbium disilicate powder into a dispersant, then adding a binder, and mixing and stirring to obtain environmental barrier coating slurry; uniformly coating the environmental barrier coating slurry on a CMC base material, heating at 70-80 DEG C to remove the dispersant, and obtaining a pretreated CMC base material; heating the pretreated CMC base material to 1500-1600 DEG C and keeping the temperature, and obtaining the self-healing ytterbia-based environmental barrier coating. The preparation method is low in cost, simple in process and controllable; the ytterbium-aluminum-silicon microcrystalline glass is in-situ crystallized at high temperature, and corrosion-resistant Yb2Si2O7 crystals and mullite crystals are precipitated; residual glass phases serve as self-healing phases and melt into Yb2Si2O7 coating to penetrate into the CMC base, a mechanical pinning effect is formed, the bonding strength of the coating and the CMC base is enhanced, and the high-temperature water-oxygen corrosion resistance is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal protection coating materials, in particular to a self-healing ytterbia-based environmental barrier coating and a preparation method thereof. BACKGROUND

[0002] Ceramic matrix composites (CMC) are expected to replace traditional high-temperature alloys as structural materials for high-temperature components of advanced aero-engine due to their light weight, high specific strength, high specific modulus and high temperature resistance. However, in practical application, CMC components produce water and oxygen corrosion and molten salt corrosion in high-temperature gas environment, resulting in reduced performance. The service life of CMC in engine environment can be effectively improved by preparing a high-temperature corrosion-resistant environmental barrier coating (EBC) on the surface of the CMC component.

[0003] The existing environmental barrier coating generally includes a silicon bonding layer and a rare earth silicate surface layer. The most typical one is the environmental barrier system of Si bonding layer and ytterbium disilicate (YbDS) surface layer, because ytterbium disilicate has only beta phase at high temperature, which is very stable, and its thermal expansion coefficient is close to that of SiC-based composite material CMC; while other rare earth element disilicates have multiple crystal forms at high temperature, which will undergo crystal transformation at high temperature, resulting in volume change in the coating, thereby generating stress and causing cracking, reducing the service life of the coating.

[0004] However, in the environmental barrier system of Si bonding layer and ytterbium disilicate (YbDS) surface layer, the melting point of the Si bonding layer is low, which cannot be used for a long time above 1400℃, and the Si bonding layer is highly sensitive to oxygen and is easily oxidized to form a new phase, resulting in stress and coating failure. It is urgent to develop an environmental barrier coating with better water and oxygen corrosion resistance, no silicon bonding layer and high bonding strength with the substrate. SUMMARY

[0005] The purpose of the present application is to provide a self-healing ytterbia-based environmental barrier coating and a preparation method thereof, aiming to solve the problems of low use temperature, poor water and oxygen corrosion resistance and easy oxidation failure of the existing environmental barrier coating.

[0006] In order to achieve the above purpose, the following technical solutions are adopted in the present application.

[0007] The first aspect of the present application provides a preparation method of a self-healing ytterbia-based environmental barrier coating, comprising:

[0008] S1, adding a self-healing agent and ytterbium disilicate powder into a dispersant, then adding a binder, mixing and stirring to obtain an environmental barrier coating slurry;

[0009] S2, uniformly coating the environmental barrier coating slurry on a CMC substrate material, heating at 70-80℃ to remove the dispersant, and obtaining a pretreated CMC substrate material;

[0010] S3, heating the pretreated CMC matrix material to 1500-1600 DEG C and holding, to obtain a self-healing ytterbia-based environmental barrier coating.

[0011] In some embodiments, the self-healing agent is ytterbia-alumina-silica glass-ceramics.

[0012] In some embodiments, the ytterbia-alumina-silica glass-ceramics is prepared by the following method:

[0013] Yb2O3 powder, Al2O3 powder and SiO2 powder are dispersed in a solvent, and mixed uniformly to obtain a pre-sintering material;

[0014] The pre-sintering material is dried and ground to obtain a fine powder, and the fine powder is heated to 1600-1800 DEG C and held for 1-2 h, and quenched to obtain ytterbia-alumina-silica glass-ceramics.

[0015] In some embodiments, the molar ratio of Yb2O3, Al2O3 and SiO2 is (0.8-1.2):(0.8-1.2):(2.4-3.6).

[0016] In some embodiments, the mass ratio of the self-healing agent to ytterbia disilicate powder is 1:10.

[0017] In some embodiments, the particle size of the self-healing agent is less than 5 μm, and the particle size of the ytterbia disilicate powder is less than 5 μm.

[0018] In some embodiments, the dispersant is anhydrous ethanol, anhydrous methanol or acetone; and the binder is a PVA solution.

[0019] In some embodiments, the ratio of the total mass of the self-healing agent and ytterbia disilicate powder to the mass of the dispersant is (1.3-2.1):(0.6-1).

[0020] In some embodiments, the amount of the binder is 1-3% of the total mass of the self-healing agent and ytterbia disilicate powder.

[0021] In a second aspect of the present application, a self-healing ytterbia-based environmental barrier coating prepared by the above preparation method is provided.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The preparation method of the present application has low cost, simple and controllable process, and the prepared environmental barrier coating has good high-temperature stability. The preparation method of the present application can be used to prepare environmental barrier coatings on complex components, and has wide applicability.

[0024] The preparation method of the application introduces ytterbium aluminum silicon glass-ceramics as a self-healing agent, so that the environmental barrier coating can be self-repaired at high temperature. The ytterbium aluminum silicon glass-ceramics in-situ crystallizes at high temperature, and precipitates ytterbium disilicate Yb2Si2O7 crystals and mullite crystals with high chemical tolerance, which have a synergistic effect, improving the corrosion resistance and melting point of the environmental barrier coating, and further improving the use temperature of the environmental barrier coating; at the same time, the residual glass phase in the ytterbium aluminum silicon glass-ceramics acts as a self-healing phase and a flux to coat the ytterbium disilicate layer into the CMC matrix, forming a mechanical pinning effect to enhance the bonding strength of the environmental barrier coating and the CMC matrix material, without the need for a silicon adhesive, and with high adhesion, avoiding coating failure caused by oxidation of the Si adhesive layer.

[0025] The self-healing ytterbium silicate-based environmental barrier coating of the application is a single-layer coating, which has high stability and can effectively protect the CMC matrix composite material after 300 hours of water and oxygen corrosion test at 1450℃, and has good water oxidation resistance. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings described below are only some embodiments described in the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0027] Figure 1 XRD spectrum of ytterbium aluminum silicon glass-ceramics prepared for Example 1;

[0028] Figure 2 XRD spectrum of YbAS-Yb2Si2O7 coating prepared for Example 1;

[0029] Figure 3 SEM spectrum of the cross section of the YbAS-Yb2Si2O7 coating prepared for Example 1;

[0030] Figure 4 Macroscopic morphology of the YbAS-Yb2Si2O7 coating prepared for Example 1 and after corrosion in a water and oxygen environment at 1450℃ for 300 hours. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0032] In the following description of the present embodiments, the terms "comprise", "contain", "have" and "include" and the like are open-ended terms, i.e., meaning "including but not limited to".

[0033] In the following description of the present embodiments, the term "and / or" is used to describe the relationship between associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the cases of A alone, B alone and A and B at the same time. Wherein A, B can be singular or plural. The character " / " generally represents that the associated objects before and after are in an "or" relationship.

[0034] In the following description of the present embodiments, the term "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or the like means any combination of the items, including any combination of single item or multiple items. For example, "at least one of a, b or c", or "at least one of a, b and c", can represent a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c can be single or multiple.

[0035] The terms used in the present embodiments are merely for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a" and "the" used in the present embodiments and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0036] Those skilled in the art should understand that in the following description of the present embodiments, the order of the serial numbers does not mean the order of execution, and some or all steps can be executed in parallel or in sequence, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the present embodiments.

[0037] Those skilled in the art should understand that in the present embodiments, the numerical range should be understood as also specifically disclosing each intermediate value between the upper limit and the lower limit of the range. Each smaller range between any stated value or stated range of intermediate values and any other stated value or intermediate value within the stated range is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0038] Unless otherwise defined, technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All documents mentioned herein are incorporated by reference to disclose and describe in full the methods and / or materials which are described therein. In case of conflict, the content of the present specification will control.

[0039] In a first aspect, the present application provides a preparation method of a self-healing ytterbia-based environmental barrier coating, comprising:

[0040] S1, adding a self-healing agent and ytterbia disilicate powder into a dispersant, then adding a binder, mixing and stirring to obtain an environmental barrier coating slurry;

[0041] S2, uniformly coating the environmental barrier coating slurry on a CMC matrix material, heating at 70-80°C to remove the dispersant, and obtaining a pretreated CMC matrix material;

[0042] S3, heating the pretreated CMC matrix material to 1500-1600°C and holding, to obtain a self-healing ytterbia-based environmental barrier coating.

[0043] In the present application, the self-healing agent is ytterbia-alumina-silica glass-ceramics. The ytterbia-alumina-silica glass-ceramics is prepared by the following method:

[0044] Disperse Yb2O3 powder, Al2O3 powder and SiO2 powder in a solvent, mix thoroughly and uniformly, to obtain pre-sintered material;

[0045] Dry and grind the pre-sintered material to obtain fine powder, heat the fine powder to 1600-1800°C for 1-2h, and quench, to obtain ytterbia-alumina-silica glass-ceramics.

[0046] Specifically, the Yb2O3 powder, Al2O3 powder and SiO2 powder are dispersed in a solvent, and the oxide powders are mixed by wet ball milling with a planetary ball mill for 6-12h. The solvent is anhydrous ethanol or acetone, preferably anhydrous ethanol. Since the densities and particle sizes of the components are not the same, wet ball milling can effectively refine the particles and make the components uniformly distributed. The pre-sintered material after wet ball milling is dried to remove the solvent, ground through a 500 mesh sieve, to obtain fine powder with a particle size of about 25μm. Heat the fine powder to 1600-1800°C for 1-2h, and quickly pour into cold water to quench, to obtain ytterbia-alumina-silica glass-ceramics (YbAS).

[0047] In the embodiments of the present application, the molar ratio of Yb2O3, Al2O3 and SiO2 is preferably (0.8-1.2):(0.8-1.2):(2.4-3.6). Within this ratio range, the ytterbium-aluminum-silicon microcrystalline glass prepared can be crystallized at high temperature to precipitate ytterbium disilicate (YbDS) and mullite Al6Si2O 13 The residual glass phase after crystallization can on the one hand act as a flux to enable liquid phase sintering of the ytterbium disilicate powder at a lower temperature, and on the other hand act as a high temperature binder to improve the adhesion of the environmental barrier coating to the CMC matrix material, and enable the environmental barrier coating to have a self-healing function. The molar ratio of Yb2O3, Al2O3 and SiO2 is more preferably 1:1:3.

[0048] In the present application, the ytterbium disilicate powder (YbDS) is prepared by a sol-gel method. Specifically, the ytterbium disilicate powder is prepared by the method described in the patent with the publication number CN102964128B and the title "A sol-gel preparation method of Yb2Si2O7 powder". The prepared ytterbium disilicate powder is wet-milled in a planetary ball mill jar for 48 hours, and the ytterbium disilicate powder after ball milling is dried and ground to a particle size of 5 μm. The ytterbium disilicate powder, as the main component of the environmental barrier coating, has excellent corrosion resistance, which improves the water and oxygen corrosion resistance of the environmental barrier coating. In addition, the ytterbium disilicate has good compatibility with the ytterbium-aluminum-silicon microcrystalline glass, and after high-temperature sintering, the glass phase of the ytterbium-aluminum-silicon microcrystalline glass can coat the ytterbium disilicate, thereby improving the bonding strength of the coating to the CMC matrix material.

[0049] In the present application, the ytterbium-aluminum-silicon microcrystalline glass powder and the ytterbium disilicate powder are proportioned according to a weight ratio of 1:10, then a dispersant is added, followed by the addition of a binder, and then the mixture is stirred by a magnetic stirrer for 12-24 hours to obtain an environmental barrier coating slurry. The dispersant is used to uniformly distribute the microcrystalline glass powder and the binder, and the dispersant can be selected from anhydrous ethanol, anhydrous methanol or acetone, and the anhydrous ethanol is preferred. The binder is used to increase the adhesion of the slurry and improve the coating effect of the slurry on the surface of the CMC matrix material, and in the embodiments of the present application, the binder is selected from a PVA solution.

[0050] In the present application, the ratio of the total mass of the ytterbium-aluminum-silicon microcrystalline glass powder and the ytterbium disilicate powder to the mass of the dispersant is (1.3-2.1):(0.6-1); and the amount of the binder is 1-3% of the total mass of the ytterbium-aluminum-silicon microcrystalline glass powder and the ytterbium disilicate powder. Within this ratio range, the environmental barrier coating slurry has a good coating effect on the surface of the CMC matrix material, and the environmental barrier coating slurry has good sintering properties.

[0051] In the present application, the environmental barrier coating slurry is applied to the CMC matrix material, and then heated to 70-80℃ and kept for 1-2 hours to fully remove the dispersant in the slurry coating, reduce the pores and defects in the slurry coating, and improve the adhesion of the sintered environmental barrier coating.

[0052] In the present application, the pretreated CMC matrix material is heated to 1500-1600℃ in a high-temperature tube furnace and kept for 1-2h, so that the YbAlSi glass-ceramics is analyzed, Yb2Si207 and mullite are precipitated, and the residual glass phase is infiltrated into the matrix as a self-healing phase and a flux coating, to obtain a YbAS-Yb2Si2O7 environmental barrier coating.

[0053] In a second aspect, the present application provides a self-healing ytterbia-based environmental barrier coating prepared by the above preparation method, which does not contain a silicon binder and has good high-temperature resistance; at the same time, it is not easy to oxidize and has good high-temperature water-oxygen corrosion resistance, with a service life of more than 300h in a water-oxygen environment at 1450℃.

[0054] The present application is further illustrated by the following examples.

[0055] It should be noted that the oxides used in the examples of the present application can be obtained by purchasing commercial products, and the purity is 99.9% and the particle size is 3-10μm.

[0056] Example 1

[0057] Yb2O3, Al2O3 and SiO2 powders are mixed according to a molar ratio of 1:1:3, anhydrous ethanol is added, and the oxide powders are fully mixed by a planetary ball mill for 12h to obtain pre-sintered material;

[0058] The pre-sintered material is dried and ground into fine powder with a particle size of about 25μm, the fine powder is loaded into an alumina crucible, heated to 1650℃ in a high-temperature glass block furnace, kept for 2h, quickly poured into cold water for quenching, to obtain ytterbia-alumina-silica glass-ceramics, denoted as YbAS; the ytterbia-alumina-silica glass-ceramics is wet-milled in a planetary ball mill jar for 48h, the milled ytterbia-alumina-silica glass-ceramics powder is dried and ground to a particle size of 5μm, and is ready for use.

[0059] Yb2Si2O7 powder is prepared by the method described in the patent with publication number CN102964128B and the name "a sol-gel preparation method of Yb2Si2O7 powder", the Yb2Si2O7 powder is wet-milled in a planetary ball mill jar for 48h, the milled Yb2Si2O7 powder is dried and ground to a particle size of 5μm, and is ready for use.

[0060] The above ytterbia-alumina-silica glass-ceramics powder and Yb2Si2O7 powder are mixed according to a mass ratio of 1:10, the mixed powder and anhydrous ethanol are then mixed according to a mass ratio of 1.7:0.8, a PVA solution with a weight of 1% of the mass of anhydrous ethanol is added, and the mixture is stirred on a magnetic stirrer for 12h to obtain an environmental barrier coating slurry;

[0061] The environmental barrier coating slurry is uniformly coated on the CMC matrix material, and the coating is kept at 70℃ for 2 hours to fully remove the anhydrous ethanol in the coating, to obtain a pretreated CMC matrix material; in this embodiment, the CMC matrix material is selected as SiC / SiC ceramic matrix composite material.

[0062] The pretreated CMC matrix material is heated to 1500℃ in a tubular high-temperature furnace and kept for 2 hours to obtain a self-healing ytterbia-based environmental barrier coating, which is recorded as YbAS-Yb2Si2O7 coating.

[0063] Example 2

[0064] Yb2O3, Al2O3 and SiO2 powders are mixed according to a molar ratio of 0.8:1.2:3.6, anhydrous ethanol is added, and the oxide powders are fully mixed in a planetary ball mill for 12 hours to obtain pre-sintered material;

[0065] The pre-sintered material is dried and ground into fine powder with a particle size of about 25μm, the fine powder is loaded into an alumina crucible, heated to 1800℃ in a high-temperature glass block furnace, kept for 1 hour, and then quickly poured into cold water to quench, to obtain ytterbia-alumina-silica glass-ceramics, which is recorded as YbAS; the ytterbia-alumina-silica glass-ceramics is wet-milled in a planetary ball mill for 48 hours, the milled ytterbia-alumina-silica glass-ceramics powder is dried, and ground to a particle size of 5μm for use.

[0066] Yb2Si2O7 powder is prepared by the method described in the patent with publication number CN102964128B and the name "a sol-gel preparation method of Yb2Si2O7 powder", the Yb2Si2O7 powder is wet-milled in a planetary ball mill for 48 hours, the milled Yb2Si2O7 powder is dried, and ground to a particle size of 5μm for use.

[0067] The ytterbia-alumina-silica glass-ceramics powder and the Yb2Si2O7 powder are mixed according to a mass ratio of 1:10, the mixed powder and anhydrous ethanol are mixed according to a mass ratio of 1.3:1, a PVA solution with a weight of 3% of the mass of the anhydrous ethanol is added, and the mixture is stirred on a magnetic stirrer for 12 hours to obtain an environmental barrier coating slurry.

[0068] The environmental barrier coating slurry is uniformly coated on the CMC matrix material, and the coating is kept at 80℃ for 2 hours to fully remove the anhydrous ethanol in the coating, to obtain a pretreated CMC matrix material; in this embodiment, the CMC matrix material is selected as SiC / SiC ceramic matrix composite material.

[0069] The pretreated CMC matrix material is heated to 1600℃ in a tubular high-temperature furnace and kept for 2 hours to obtain a self-healing ytterbia-based environmental barrier coating.

[0070] Example 3

[0071] Mix Yb2O3, Al2O3, SiO2 powders according to the molar ratio of 1.2:0.8:2.4, add anhydrous ethanol, and mix the oxide powders by using a planetary ball mill for 12 hours to obtain a pre-sintered material;

[0072] Dry the pre-sintered material, grind it into a fine powder with a particle size of about 25 μm, and load the fine powder into an alumina crucible. Heat the crucible to 1700℃ in a high-temperature glass block furnace, keep it at this temperature for 1 hour, and then quickly pour it into cold water to quench it. In this way, ytterbium-aluminum-silicon glass-ceramics, denoted as YbAS, is obtained. Wet mill the ytterbium-aluminum-silicon glass-ceramics in a planetary ball mill jar for 48 hours. Dry the milled ytterbium-aluminum-silicon glass-ceramics powder, and grind it to a particle size of 5 μm. The powder is ready for use.

[0073] Prepare ytterbium disilicate powder by using the method described in the patent with the publication number CN102964128B and the title “A sol-gel preparation method for Yb2Si2O7 powder”. Wet mill the ytterbium disilicate powder in a planetary ball mill jar for 48 hours. Dry the milled ytterbium disilicate powder, and grind it to a particle size of 5 μm. The powder is ready for use.

[0074] Mix the ytterbium-aluminum-silicon glass-ceramics and the ytterbium disilicate powder according to the mass ratio of 1:10. Then, mix the mixed powder and anhydrous ethanol according to the mass ratio of 2.1:0.6. Add a PVA solution with a weight of 1% of the mass of the anhydrous ethanol. Stir the mixture on a magnetic stirrer for 12 hours to obtain an environmental barrier coating slurry.

[0075] Coat the environmental barrier coating slurry evenly on a CMC matrix material. Keep the coated material at 80℃ for 2 hours to fully remove the anhydrous ethanol in the coating. In this way, a pretreated CMC matrix material is obtained. In this embodiment, the CMC matrix material is a SiC / SiC ceramic matrix composite material.

[0076] Heat the pretreated CMC matrix material in a tubular high-temperature furnace to 1550℃, and keep it at this temperature for 2 hours. In this way, a self-healing ytterbium silicate-based environmental barrier coating is obtained.

[0077] Perform XRD tests on the ytterbium-aluminum-silicon glass-ceramics prepared in Example 1 and the YbAS-Yb2Si2O7 coating prepared in Example 1. The spectra are shown in Figure 1 and Figure 2 .

[0078] As can be seen from Figure 1 , the XRD spectrum of the ytterbium-aluminum-silicon glass-ceramics exhibits amorphous characteristics, indicating that the ytterbium-aluminum-silicon glass-ceramics is in an amorphous state.

[0079] As can be seen from Figure 2It can be seen that Yb2Si2O7 and Mullite crystalline phases appear in the XRD spectrum of the YbAS-Yb2Si2O7 coating, proving that after heat treatment at 1550℃, the ytterbium aluminum silicon glass-ceramics undergoes in-situ crystallization and precipitates Yb2Si2O7 and Mullite crystalline phases; due to the low content of residual glass phase, the XRD system did not detect the residual glass phase.

[0080] The YbAS-Yb2Si2O7 coating prepared in Example 1 was subjected to a high-temperature water-oxygen corrosion performance test. The test method is as follows:

[0081] The corrosion resistance test of the environmental barrier coating is carried out in an environment of 1450°C, 90% water vapor-10% oxygen (90% and 10% are volume percentages), and a pressure of 1 atm until the coating shows obvious peeling (peeling area greater than 10%), which is defined as failure.

[0082] The YbAS-Yb2Si2O7 coating prepared in Example 1 was subjected to SEM testing to observe its cross-sectional morphology. Figure 3 As shown. Figure 3 The YbAS-Yb2Si2O7 coating is dense and defect-free, and penetrates the CMC substrate, forming a mechanical pinning effect and maintaining a strong bond with the CMC substrate. Furthermore, the YbAS-Yb2Si2O7 coating contains a large number of corrosion-resistant crystalline phases, which improves its resistance to water and oxygen corrosion at high temperatures. Furthermore, the YbAS-Yb2Si2O7 coating is a single layer, which offers greater stability than dual-layer or multi-layer environmental barrier coatings.

[0083] Figure 4 The YbAS-Yb2Si2O7 coating prepared in Example 1 and its macroscopic appearance after being corroded in a water-oxygen environment at 1450°C for 300 hours. Figure 4 As shown, after 300 hours of corrosion in a 1450°C water-oxygen environment, the YbAS-Yb2Si2O7 coating remained essentially unchanged, with no macroscopic defects such as cracking or flaking. The YbAS-Yb2Si2O7 coating of this application exhibits excellent high-temperature stability and corrosion resistance without requiring a silicon bonding layer.

[0084] The environmental barrier coatings prepared in Example 2 and Example 3 were subjected to a high-temperature water-oxygen corrosion performance test, and both had good water-oxygen corrosion resistance.

[0085] The self-healing ytterbium silicate-based environmental barrier coating prepared in this application is silicone-free and resistant to corrosion at 1450°C, demonstrating excellent high-temperature performance. It also boasts a lifespan exceeding 300 hours of high-temperature water-oxygen corrosion resistance and is not susceptible to oxidation failure, thus possessing broad application prospects. The ceramic-based composite material containing this environmental barrier coating exhibits excellent high-temperature resistance and a long lifespan in high-temperature water-oxygen corrosion resistance, making it suitable for the manufacture of high-temperature components in aircraft engines.

[0086] While the application has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. It is therefore intended that whatever lies within the scope of the application be covered by the appended claims.

Claims

1. A method for preparing a self-healing ytterbium silicate-based environmental barrier coating, characterized in that: include: S1, adding a self-healing agent and ytterbium disilicate powder to a dispersant, then adding a binder, and mixing and stirring to obtain an environmental barrier coating slurry; S2, uniformly coating the environmental barrier coating slurry on the CMC substrate material, heating at 70-80° C. to remove the dispersant, thereby obtaining a pretreated CMC substrate material; S3, heating the pretreated CMC substrate material to 1500-1600° C. and maintaining the temperature to obtain a self-healing ytterbium silicate-based environmental barrier coating; The self-healing agent is ytterbium aluminum silicon glass-ceramics.

2. The method for preparing the self-healing ytterbium silicate-based environmental barrier coating according to claim 1, characterized in that: The ytterbium aluminum silicon glass-ceramics is prepared by the following method: Disperse Yb2O3 powder, Al2O3 powder and SiO2 powder in a solvent and mix them thoroughly to obtain a pre-sintered material; The pre-sintered material is dried and ground to obtain fine powder, the fine powder is heated to 1600-1800° C. and kept warm for 1-2 hours, and quenched to obtain ytterbium aluminum silicon glass-ceramics.

3. The method for preparing the self-healing ytterbium silicate-based environmental barrier coating according to claim 2, characterized in that: The molar ratio of Yb2O3, Al2O3 and SiO2 is (0.8-1.2):(0.8-1.2):(2.4-3.6).

4. The method for preparing the self-healing ytterbium silicate-based environmental barrier coating according to claim 1, characterized in that: The mass ratio of the self-healing agent to the ytterbium disilicate powder is 1:

10.

5. The method for preparing the self-healing ytterbium silicate-based environmental barrier coating according to claim 1, characterized in that: The particle size of the self-healing agent is less than 5 μm, and the particle size of the ytterbium disilicate powder is less than 5 μm.

6. The method for preparing the self-healing ytterbium silicate-based environmental barrier coating according to claim 1, characterized in that: The dispersant is anhydrous ethanol, anhydrous methanol or acetone; and the binder is PVA solution.

7. The method for preparing a self-healing ytterbium silicate-based environmental barrier coating according to claim 1, characterized in that: The ratio of the total mass of the self-healing agent and the ytterbium disilicate powder to the mass of the dispersant is (1.3-2.1):(0.6-1).

8. The method for preparing a self-healing ytterbium silicate-based environmental barrier coating according to claim 1, wherein: The amount of the binder is 1-3% of the total mass of the self-healing agent and ytterbium disilicate powder.

9. A self-healing ytterbium silicate-based environmental barrier coating prepared according to the method for preparing a self-healing ytterbium silicate-based environmental barrier coating according to any one of claims 1 to 8.

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