Thermal barrier-environmental barrier coating materials, methods of making and using the same, and thermal barrier-environmental barrier coatings and methods of making the same

Abstract

The present application relates to the technical field of thermal barrier-environment barrier coating materials, and particularly relates to a thermal barrier-environment barrier coating material, a preparation method and application thereof, and a thermal barrier-environment barrier coating and a preparation method thereof.The thermal barrier-environment barrier coating material is a complex material containing rare earth monosilicate and rare earth disilicate; the rare earth monosilicate is monoclinic structure, and the space group is C2 / c; the rare earth disilicate is beta-monoclinic structure and / or gamma-monoclinic structure; the space group of the beta-monoclinic structure is C2 / m; and the space group of the gamma-monoclinic structure is P21 / c.The thermal barrier-environment barrier coating material prepared by the present application is a complex material containing rare earth monosilicate and rare earth disilicate, which has lower thermal conductivity and higher toughness compared with pure-phase double-rare earth silicate, and has higher toughness and lower thermal expansion coefficient compared with pure-phase rare earth monosilicate, and has more excellent performance when applied in the fields of aerospace engines, high-temperature gas turbines and the like.

Description

Technical Field

[0001] This invention relates to the field of thermal barrier-environmental barrier coating materials, and particularly to thermal barrier-environmental barrier coating materials, their preparation methods and applications, and thermal barrier-environmental barrier coatings and their preparation methods. Background Technology

[0002] To meet the high-temperature protection requirements of hot-end components such as aerospace engines and high-temperature gas turbines, it is necessary to find ceramic thermal barrier coating materials with excellent thermal insulation and mechanical properties.

[0003] Traditional high-temperature alloys have reached their theoretical limits, necessitating the development of more heat-resistant alternatives. Among these, ceramic fiber reinforced ceramic matrix composites (CMCs) hold the greatest potential. While CMCs offer numerous advantages over high-temperature alloys, including high temperature resistance, low density, and strong high-temperature mechanical properties, several limitations remain in high-temperature combustion environments, restricting their further application. SiC matrix materials exhibit excellent oxidation resistance in dry, high-temperature environments with oxygen, forming a dense SiO2 layer on their surface. This passivation and oxidation limitation protects the CMCs. However, in steam environments, SiO2 is rapidly lost, leading to a sharp decline in CMC performance. To address this, researchers have discovered that depositing a SiO2 coating followed by a Yb₂Si₂O₇ or Y₂Si₂O₇ coating on CMC ceramics effectively improves their service temperature and lifespan. However, Yb₂Si₂O₇ and Y₂Si₂O₇ exhibit high thermal conductivity and poor fracture toughness. To address the aforementioned issues, there is a need to find a thermal barrier-environmental barrier coating material with low thermal conductivity, high toughness, and resistance to water vapor corrosion to protect the substrate. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, this invention provides a thermal barrier-environmental barrier coating material, its preparation method, and its application; and a thermal barrier-environmental barrier coating material and its preparation method, wherein the coating material, by controlling the total amount and type of rare earth doping elements, becomes a multiphase material containing rare earth monosilicates and rare earth disilicates, exhibiting high fracture toughness and low thermal conductivity.

[0005] To this end, the first aspect of the present invention provides a thermal barrier-environmental barrier coating material, wherein the thermal barrier-environmental barrier coating material is a multiphase material comprising rare earth monosilicate and rare earth disilicate;

[0006] The rare earth monosilicate has a monoclinic structure and a space group of C2 / c.

[0007] The rare earth bissilicate has a β-monoclinic structure and / or a γ-monoclinic structure;

[0008] The space group of the β-monoclinic structure is C2 / m; the space group of the γ-monoclinic structure is P21 / c.

[0009] This invention provides a thermal barrier-environmental barrier coating material, which is composed of rare earth monosilicate and rare earth disilicate composite materials. The rare earth monosilicate and rare earth disilicate have a specific spatial structure, which makes the obtained thermal barrier-environmental barrier coating material have high toughness and low thermal conductivity.

[0010] According to an embodiment of the present invention, the chemical composition of the thermal barrier-environmental barrier coating material satisfies: (RE₂O₃) x (SiO2) 1-x ;

[0011] Where RE represents rare earth elements; 0.33 <x<0.5。

[0012] According to an embodiment of the present invention, the rare earth element is provided by a rare earth oxide, which includes Gd₂O₃, Dy₂O₃, and Ho₂O. 3、 At least two of Y2O3, Er2O3, Yb2O3, Lu2O3, or Sc2O3.

[0013] According to an embodiment of the present invention, the molar amounts of Gd2O3 and Dy2O3 account for x1 and x2 of the total molar amounts of the rare earth oxides, respectively;

[0014] Where x1 + x2 ≤ 30 mol%

[0015] The percentages of the molar amounts of Ho2O3, Y2O3, Er2O3, Yb2O3, Lu2O3, and Sc2O3 relative to the total molar amounts of the rare earth oxides are y1, y2, y3, y4, y5, and y6, respectively.

[0016] Among them, y1 + y2 + y3 + y4 + y5 + y6 ≥ 70 mol.

[0017] According to an embodiment of the present invention, the particle size of the thermal barrier-environmental barrier coating material is 30-110 μm.

[0018] A second aspect of the present invention provides a method for preparing the thermal barrier-environmental barrier coating material described in the first aspect, comprising the following steps:

[0019] Silicon oxide and rare earth oxides were mixed to obtain mixture 1;

[0020] The mixture 1 is subjected to ball milling and calcination once to obtain mixture 2;

[0021] The mixture 2 is subjected to secondary ball milling, granulation, and secondary calcination to obtain the thermal barrier-environmental barrier coating material.

[0022] The preparation method provided by the present invention controls the total amount and type of rare earth doping elements, as well as the ratio of rare earth oxides to silicon oxides, so that the obtained thermal barrier-environmental barrier coating material is a rare earth monosilicate and rare earth disilicate composite material, thereby having high fracture toughness and low thermal conductivity.

[0023] According to an embodiment of the present invention, the time for one ball milling is 3-6 hours.

[0024] According to an embodiment of the present invention, the temperature of the first calcination is 1000-1250°C.

[0025] According to an embodiment of the present invention, the calcination time is 2-4 hours.

[0026] According to an embodiment of the present invention, the secondary ball milling time is 6-10 hours.

[0027] According to an embodiment of the present invention, the temperature of the secondary calcination is 1350-1500℃.

[0028] According to an embodiment of the present invention, the secondary calcination time is 3-4 hours.

[0029] The third aspect of the present invention provides a method for preparing a thermal barrier-environmental barrier coating, comprising the following steps: depositing or coating the thermal barrier-environmental barrier coating material described in the first aspect or the thermal barrier-environmental barrier coating material obtained according to the preparation method described in the second aspect onto the surface of a substrate to obtain the thermal barrier-environmental barrier coating.

[0030] Because the rare earth monosilicate and rare earth disilicate are uniformly mixed in the thermal barrier-environmental barrier coating material prepared by this invention, the resulting coating has a uniform composition and fine grains, which is beneficial to improving the thermal cycling performance of the coating.

[0031] The fourth aspect of the present invention provides a thermal barrier-environmental barrier coating obtained by the preparation method described in the third aspect.

[0032] The fifth aspect of the present invention provides the application of the thermal barrier-environmental barrier coating material described in the first aspect or the thermal barrier-environmental barrier coating material obtained according to the preparation method described in the second aspect in the aerospace field and / or heavy-duty gas turbines.

[0033] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0034] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0035] Figure 1 The XRD patterns of the thermal barrier-environmental barrier coating materials prepared in Examples 1-3 and Comparative Examples 1-2 of this invention after calcination at 1400°C for 100 h are shown.

[0036] Figure 2 The images show SEM images of the thermal barrier-environmental barrier coating materials prepared in Examples 1-3 of the present invention. Specifically, image a is the SEM image of the thermal barrier-environmental barrier coating material prepared in Example 1; image b is the SEM image of the thermal barrier-environmental barrier coating material prepared in Example 2; and image c is the SEM image of the thermal barrier-environmental barrier coating material prepared in Example 3.

[0037] Figure 3 The image shows a SEM image of the thermal barrier-environmental barrier coating material prepared in Example 1 of the present invention. Detailed Implementation

[0038] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0040] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0041] To facilitate understanding of the invention, certain technical and scientific terms are specifically defined below. Unless otherwise expressly defined elsewhere in this document, all other technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains.

[0042] In this document, the terms “comprising” or “including” are open-ended expressions, meaning that they include the contents specified in this invention, but do not exclude other aspects.

[0043] In this document, the terms “optionally,” “optionally,” or “optionally” generally refer to an event or condition that may, but may not, occur, and the description includes both cases in which the event or condition occurs and cases in which the event or condition does not occur.

[0044] According to an embodiment of the present invention, a first aspect of the present invention provides a thermal barrier-environmental barrier coating material, wherein the thermal barrier-environmental barrier coating material is a multiphase material comprising rare earth monosilicate and rare earth disilicate;

[0045] The rare earth monosilicate has a monoclinic structure and a space group of C2 / c.

[0046] The rare earth bissilicate has a β-monoclinic structure and / or a γ-monoclinic structure;

[0047] The space group of the β-monoclinic structure is C2 / m; the space group of the γ-monoclinic structure is P21 / c.

[0048] This material has a quasi-eutectic structure with deflection and bridging between grains, thus exhibiting better toughness and lower thermal conductivity compared to single-phase materials.

[0049] According to a specific embodiment of the present invention, the chemical composition of the thermal barrier-environmental barrier coating material satisfies: (RE₂O₃) x (SiO2) 1-x ;

[0050] Where RE represents rare earth elements; 0.33 <x<0.5。

[0051] According to specific embodiments of the present invention, the value of x is not particularly limited. As some specific examples, x can be 0.34, 0.39, 0.44, 0.49, etc.

[0052] According to specific embodiments of the present invention, the rare earth element is provided by a rare earth oxide, and the type of rare earth oxide is not particularly limited. As some specific examples, the rare earth oxide includes Gd₂O₃, Dy₂O₃, and Ho₂O. 3、 At least two of Y2O3, Er2O3, Yb2O3, Lu2O3, or Sc2O3.

[0053] According to a specific embodiment of the present invention, the molar amounts of Gd2O3 and Dy2O3 account for x1 and x2 of the total molar amounts of the rare earth oxides, respectively;

[0054] Where x1 + x2 ≤ 30 mol%

[0055] The percentages of the molar amounts of Ho2O3, Y2O3, Er2O3, Yb2O3, Lu2O3, and Sc2O3 relative to the total molar amounts of the rare earth oxides are y1, y2, y3, y4, y5, and y6, respectively.

[0056] Among them, y1 + y2 + y3 + y4 + y5 + y6 ≥ 70 mol.

[0057] According to specific embodiments of the present invention, the value of x1 + x2 is not particularly limited. As some specific examples, the value of x1 + x2 can be 0 mol%, 10 mol%, 20 mol%, 30 mol%, etc.; the value of y1 + y2 + y3 + y4 + y5 + y6 is not particularly limited. As some specific examples, the value of y1 + y2 + y3 + y4 + y5 + y6 can be 70 mol%, 80 mol%, 90 mol%, 100 mol%, etc.

[0058] According to specific embodiments of the present invention, the particle size of the thermal barrier-environmental barrier coating material is 30-110 μm. As some specific examples, the particle size of the thermal barrier-environmental barrier coating material can be 30 μm, 50 μm, 70 μm, 90 μm, 110 μm, etc.

[0059] According to embodiments of the present invention, a second aspect provides a method for preparing the thermal barrier-environmental barrier coating material described in the first aspect, comprising the following steps:

[0060] Silicon oxide and rare earth oxides were mixed to obtain mixture 1;

[0061] The mixture 1 is subjected to ball milling and calcination once to obtain mixture 2;

[0062] The mixture 2 is subjected to secondary ball milling, granulation, and secondary calcination to obtain the thermal barrier-environmental barrier coating material.

[0063] By adjusting the total amount and type of rare earth doping elements, as well as the ratio of rare earth oxides to silicon oxide, the crystal phase type and structure of the generated material can be changed. Using the raw material ratio in the preparation method described in this invention, a rare earth monosilicate and rare earth disilicate composite material can be obtained. Compared with pure phase dirare earth silicates, it has lower thermal conductivity and higher toughness, and compared with pure phase rare earth monosilicates, it has higher toughness and lower coefficient of thermal expansion.

[0064] According to a specific embodiment of the present invention, the ball milling time is 3-6 hours. As some specific examples, the ball milling time can be 3 hours, 4 hours, 5 hours, 6 hours, etc. Specifically, the medium used for the ball milling is not particularly limited and can be zirconium oxide balls and alcohol, etc. After ball milling, separation treatment can be performed to obtain a precipitate, which is then ground, sieved, and subjected to a first calcination treatment.

[0065] According to a specific embodiment of the present invention, the temperature of the first calcination is 1000-1250℃. As some specific examples, the temperature of the first calcination can be 1000℃, 1050℃, 1100℃, 1150℃, 1200℃, 1250℃, etc.

[0066] According to a specific embodiment of the present invention, the calcination time is 2-4 hours. As some specific examples, the calcination time can be 2 hours, 3 hours, 4 hours, etc.

[0067] According to a specific embodiment of the present invention, the secondary ball milling time is 6-10 hours. As some specific examples, the secondary ball milling time can be 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, etc.

[0068] According to a specific embodiment of the present invention, the granulation includes granulating powder with a particle size of 200-300 mesh. The granulation method is not particularly limited, and includes, but is not limited to, spray granulation.

[0069] According to a specific embodiment of the present invention, the temperature of the secondary calcination is 1350-1500℃. As some specific examples, the temperature of the secondary calcination can be 1350℃, 1400℃, 1450℃, 1500℃, etc.

[0070] According to a specific embodiment of the present invention, the secondary calcination time is 3-4 hours. As some specific examples, the secondary calcination time can be 3 hours, 3.5 hours, 4 hours, etc. Specifically, after the secondary calcination, the product can be sieved to screen out particles with a size of 30-110 μm.

[0071] According to a specific embodiment of the present invention, the preparation method may further include molding the thermal barrier-environmental barrier coating material to facilitate subsequent application. Specifically, the molding process may involve a combination of pre-pressing and cold isostatic pressing.

[0072] According to a specific embodiment of the present invention, the preparation method further includes: removing impurities from the silicon oxide and rare earth oxides. The impurity removal method is not particularly limited; as some specific examples, the raw materials can be calcined at high temperature to remove adsorbed impurities such as water and carbon dioxide.

[0073] According to a specific embodiment of the present invention, a third aspect of the present invention provides a method for preparing a thermal barrier-environmental barrier coating, comprising the following steps: depositing or coating the thermal barrier-environmental barrier coating material described in the first aspect or the thermal barrier-environmental barrier coating material obtained according to the preparation method described in the second aspect onto the surface of a substrate to obtain the thermal barrier-environmental barrier coating.

[0074] Because the rare earth monosilicate and rare earth disilicate are uniformly mixed in the thermal barrier-environmental barrier coating material prepared by this invention, the resulting coating has a uniform composition and fine grains, which is beneficial to improving the thermal cycling performance of the coating.

[0075] According to specific embodiments of the present invention, the coating method is not particularly limited, and as some specific examples, it includes, but is not limited to, atmospheric plasma spraying.

[0076] According to a specific embodiment of the present invention, a fourth aspect of the present invention provides a thermal barrier-environmental barrier coating obtained according to the preparation method described in the third aspect.

[0077] According to specific embodiments of the present invention, the fifth aspect of the present invention provides the application of the thermal barrier-environmental barrier coating material described in the first aspect or the thermal barrier-environmental barrier coating material obtained according to the preparation method described in the second aspect in the aerospace field and / or heavy-duty gas turbines.

[0078] The thermal barrier-environmental barrier coating material obtained by this invention has excellent thermal insulation performance and mechanical toughness, which can meet the high-temperature protection requirements of hot-end components such as aerospace engines and high-temperature gas turbines.

[0079] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0080] Example 1

[0081] The preparation method of the thermal barrier-environmental barrier coating material in this embodiment is as follows:

[0082] (a) Ho2O3, Er2O3, Y2O3, Yb2O3, Sc2O3 and SiO2 were calcined at 1100℃ for 1h to remove adsorbed water and carbon dioxide and other impurities;

[0083] (b) The dried Ho2O3, Er2O3, Y2O3, Yb2O3, Sc2O3 and SiO2 are mixed according to [(Ho 0.2 Er 0.2 Y0.2 Yb 0.2 Sc 0.2 )2O3] 0.4 -(SiO2) 0.6 Weigh out the proportions to obtain mixture 1;

[0084] (c) The mixture 1 is ball-milled once, wherein the media for the ball milling is zirconia balls and alcohol, and the ball milling time is 5 hours.

[0085] (d) Separate the slurry after one ball milling, grind and sieve the obtained blocks, and then calcine them once at a temperature of 1100℃ for 2 hours to obtain mixture 2;

[0086] (e) The mixture 2 was ball-milled twice for 6 hours, and then passed through a 200-mesh sieve;

[0087] (f) Spray granulation, followed by secondary calcination at 1500℃ for 3 hours, and then sieved to select particles with a size of 30-70μm.

[0088] (g) Using a 15mm diameter abrasive, the particles prepared in step (f) are pre-pressed to a pressure of 100MPa; using cold isostatic pressing, the obtained blank is held at 200MPa for 60s, and then the block is calcined at 1600℃ for 10 hours to obtain [(Ho 0.2 Er 0.2 Y 0.2 Yb 0.2 Sc 0.2 )2O3] 0.4 -(SiO2) 0.6 For subsequent performance testing.

[0089] The XRD pattern of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows: Figure 1 As shown, the SEM image is as follows: Figure 2-3 As shown, the fracture toughness, structure, thermal conductivity, and coefficient of thermal expansion are presented in Table 1. Figure 1 As shown in Table 1, the thermal barrier-environmental barrier coating material prepared in this embodiment comprises rare earth monosilicates (monoclinic structure, space group C2 / c) and rare earth disilicates (β-monoclinic structure, space group C2 / m), and is composed of... Figure 2 It can be seen that the two phases coexist inside the sample, indicating that the thermal barrier-environmental barrier coating material prepared in this embodiment has formed a quasi-eutectic structure. Figure 3 It can be seen that the crack deflected and bridged multiple times during the propagation process, indicating that the thermal barrier-environmental barrier coating material prepared in this embodiment has high toughness.

[0090] Example 2

[0091] The difference between the preparation method of the thermal barrier-environmental barrier coating material in this embodiment and the preparation method of the thermal barrier-environmental barrier coating material in Example 1 is only that:

[0092] The raw materials in step (a) are Lu₂O₃, Gd₂O₃, Y₂O₃, Yb₂O₃, and SiO₂. The chemical formula is [(Gd₂O₃, Gd₂O₃, Yb₂O₃, and SiO₂]. 0.25 Y 0.25 Yb 0.25 Lu 0.25 )2O3] 0.4 -(SiO2) 0.6 .

[0093] The XRD pattern of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows: Figure 1 As shown, the SEM image is as follows: Figure 2 As shown, the fracture toughness, structure, thermal conductivity, and coefficient of thermal expansion are presented in Table 1. Figure 1 As shown in Table 1, the thermal barrier-environmental barrier coating material prepared in this embodiment comprises rare earth monosilicates (monoclinic structure, space group C2 / c) and rare earth disilicates (β-monoclinic structure, space group C2 / m), and is composed of... Figure 2 It can be seen that the two phases coexist inside the sample, indicating that the thermal barrier-environmental barrier coating material prepared in this embodiment has formed a quasi-eutectic structure.

[0094] Example 3

[0095] The difference between the preparation method of the thermal barrier-environmental barrier coating material in this embodiment and the preparation method of the thermal barrier-environmental barrier coating material in Example 1 is only that:

[0096] The raw materials in step (a) are Lu2O3, Gd2O3, Y2O3, Yb2O3, and Ho2O. 3、 Dy₂O₃, Er₂O₃, and SiO₂. The chemical formula is [(Gd...]. 1 / 7 Dy 1 / 7 Ho 1 / 7 Y 1 / 7 Er 1 / 7 Yb 1 / 7 Lu 1 / 7 )2O3] 0.4 -(SiO2) 0.6 .

[0097] The XRD pattern of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows: Figure 1 As shown, the SEM image is as follows: Figure 2 As shown, the fracture toughness, structure, thermal conductivity, and coefficient of thermal expansion are presented in Table 1. Figure 1As shown in Table 1, the thermal barrier-environmental barrier coating material prepared in this embodiment comprises rare earth monosilicates (monoclinic structure, space group C2 / c) and rare earth disilicates (β-monoclinic structure, space group C2 / m), and is composed of... Figure 2 It can be seen that the two phases coexist inside the sample, indicating that the thermal barrier-environmental barrier coating material prepared in this embodiment has formed a quasi-eutectic structure.

[0098] Example 4

[0099] The difference between the preparation method of the thermal barrier-environmental barrier coating material in this embodiment and the preparation method of the thermal barrier-environmental barrier coating material in Example 1 is only that:

[0100] The raw materials in step (a) are Lu₂O₃, Gd₂O₃, Y₂O₃, Yb₂O₃, Ho₂O₃, Dy₂O₃, Er₂O₃, Sc₂O₃, and SiO₂. The chemical formula is [(Gd₂O₃, Gd₂O₃, Y₂O₃, Yb₂O₃, Ho₂O₃, Dy₂O₃, Er₂O₃, Sc₂O₃, and SiO₂. 1 / 8 Dy 1 / 8 Ho 1 / 8 Y 1 / 8 Er 1 / 8 Yb 1 / 8 Lu 1 / 8 Sc 1 / 8 )2O3] 0.4 -(SiO2) 0.6 .

[0101] Example 5

[0102] The difference between the preparation method of the thermal barrier-environmental barrier coating material in this embodiment and the preparation method of the thermal barrier-environmental barrier coating material in Example 1 is only that:

[0103] The raw materials in step (a) are Lu₂O₃, Gd₂O₃, and SiO₂. The chemical formula is [(Gd₂O₃, Gd₂O₃, and SiO₂]. 1 / 4 Lu 3 / 4 )2O3] 0.4 -(SiO2) 0.6 .

[0104] Comparative Example 1

[0105] The only difference between the preparation method of the thermal barrier-environmental barrier coating material in this comparative example and the preparation method of the thermal barrier-environmental barrier coating material in Example 1 is:

[0106] In step (a), the raw materials are Y2O3 and SiO2, with a molar ratio of 1:2.

[0107] The XRD pattern of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows: Figure 1 As shown, the fracture toughness, structure, thermal conductivity, and coefficient of thermal expansion are presented in Table 1. Figure 1As shown in Table 1, the thermal barrier-environmental barrier coating material prepared in this comparative example is Y2Si2O7 with a γ-monoclinic structure.

[0108] Comparative Example 2

[0109] The only difference between the preparation method of the thermal barrier-environmental barrier coating material in this comparative example and the preparation method of the thermal barrier-environmental barrier coating material in Example 1 is:

[0110] In step (a), the raw materials are Yb2O3 and SiO2, with a molar ratio of 1:2.

[0111] The XRD pattern of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows: Figure 1 As shown, the fracture toughness, structure, thermal conductivity, and coefficient of thermal expansion are presented in Table 1. Figure 1 As shown in Table 1, the thermal barrier-environmental barrier coating material prepared in this comparative example is Yb2Si2O7 with a β-monoclinic structure.

[0112] Test case

[0113] The fracture toughness, structure, thermal conductivity, and coefficient of thermal expansion of the thermal barrier-environmental barrier coating materials prepared in the examples and comparative examples were tested. The test methods are as follows: (1) Fracture toughness test of thermal barrier-environmental barrier coating materials:

[0114] According to national standards, the fracture toughness of the specimen is measured using the three-point bending method. The specimen is 20mm×4mm×2mm in size, and a wire cutting technique is used to pre-make a notch with a depth of about 2mm. The fracture toughness of the specimen is then measured using a universal testing machine.

[0115] (2) Structural testing of thermal barrier-environmental barrier coating materials:

[0116] The thermal barrier-environmental barrier coating materials prepared in the examples and comparative examples were calcined at 1400°C for 100 h, and their structures were analyzed using XRD patterns.

[0117] (3) Thermal conductivity test of thermal barrier-environmental barrier coating materials:

[0118] First, the thermal diffusivity (λ) of the sample was measured using the laser flash apparatus (LFA) method. Then, the specific heat capacity (C) of the sample was measured using the Neumann–Kopp rule. P Then the thermal conductivity (κ) of the material was calculated:

[0119]

[0120] (4) Test of thermal expansion coefficient of thermal barrier-environmental barrier coating material:

[0121] The coefficient of thermal expansion was tested from room temperature (25°C) to 1300°C using a thermal expansion coefficient tester according to the test method of standard ASTM E831-06. The test results are shown in Table 1.

[0122] Table 1

[0123]

[0124] As shown in Table 1, the toughness of Examples 1-5 is significantly higher than that of Comparative Examples 1-2, and the thermal conductivity of Examples 1-5 is significantly lower than that of Comparative Examples 1-2. This indicates that the thermal barrier-environmental barrier coating material prepared by the method of the present invention has lower thermal conductivity and higher toughness than pure phase dual rare earth silicates, and its coefficient of thermal expansion is adjustable. It has superior performance when applied to aerospace engines, high-temperature gas turbines and other fields.

[0125] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0126] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A thermal barrier-environmental barrier coating material, characterized in that, The thermal barrier-environmental barrier coating material is a multiphase material containing rare earth monosilicates and rare earth disilicates. The rare earth monosilicate has a monoclinic structure and a space group of C2 / c. The rare earth bissilicate has a β-monoclinic structure and / or a γ-monoclinic structure; The space group of the β-monoclinic structure is C2 / m; the space group of the γ-monoclinic structure is P21 / c. The rare earth elements are provided by rare earth oxides, including Gd₂O₃, Dy₂O₃, and Ho₂O. 3、 At least two of Y₂O₃, Er₂O₃, Yb₂O₃, Lu₂O₃, or Sc₂O₃ The percentages of the molar amounts of Gd2O3 and Dy2O3 to the total molar amounts of the rare earth oxides are x1 and x2, respectively. Where x1 + x2 ≤ 30 mol% The percentages of the molar amounts of Ho2O3, Y2O3, Er2O3, Yb2O3, Lu2O3, and Sc2O3 relative to the total molar amounts of the rare earth oxides are y1, y2, y3, y4, y5, and y6, respectively. Among them, y1 + y2 + y3 + y4 + y5 + y6 ≥ 70 mol.

2. The thermal barrier-environmental barrier coating material according to claim 1, characterized in that, The chemical composition of the thermal barrier-environmental barrier coating material satisfies: (RE2O3) x (SiO2) 1-x ; Where RE represents rare earth elements; 0.33 <x<0.5。 3. The thermal barrier-environmental barrier coating material according to claim 1, characterized in that, The particle size of the thermal barrier-environmental barrier coating material is 30-110 μm.

4. A method for preparing a thermal barrier-environmental barrier coating material according to any one of claims 1-3, characterized in that, include: Silicon oxide and rare earth oxides were mixed to obtain mixture 1; The mixture 1 is subjected to ball milling and calcination once to obtain mixture 2; The mixture 2 is subjected to secondary ball milling, granulation, and secondary calcination to obtain the thermal barrier-environmental barrier coating material.

5. The preparation method according to claim 4, characterized in that, The ball milling time is 3-6 hours.

6. The preparation method according to claim 5, characterized in that, The temperature of the first calcination is 1000-1250℃.

7. The preparation method according to claim 5, characterized in that, The calcination time for one calcination is 2-4 hours.

8. The preparation method according to claim 4, characterized in that, The secondary ball milling time is 6-10 hours.

9. The preparation method according to claim 8, characterized in that, The temperature of the secondary calcination is 1350-1500℃.

10. The preparation method according to claim 8, characterized in that, The secondary calcination time is 3-4 hours.

11. A method for preparing a thermal barrier-environmental barrier coating, characterized in that, include: The thermal barrier-environmental barrier coating material according to any one of claims 1-3 or the thermal barrier-environmental barrier coating material obtained by the preparation method according to any one of claims 4-10 is deposited or coated on the surface of the substrate to obtain the thermal barrier-environmental barrier coating.

12. A thermal barrier-environmental barrier coating, characterized in that, The thermal barrier-environmental barrier coating is obtained by the preparation method described in claim 11.

13. The application of a thermal barrier-environmental barrier coating material according to any one of claims 1-3 or a thermal barrier-environmental barrier coating material obtained by the preparation method according to any one of claims 4-10 in the aerospace field and / or heavy-duty gas turbines.

Images