Thermal barrier-environmental barrier coating material, preparation method and application thereof, thermal barrier-environmental barrier coating and preparation method thereof

Abstract

The invention relates to the technical field of thermal barrier-environmental barrier coating materials, in particular to a thermal barrier-environmental barrier coating material, a preparation method and application of the thermal barrier-environmental barrier coating material, a thermal barrier-environmental barrier coating and a preparation method of the thermal barrier-environmental barrier coating. The thermal barrier-environmental barrier coating material is a multiphase material containing rare earth monosilicate and rare earth disilicate; wherein the rare earth monosilicate is of a monoclinic structure, and the space group is C2 / m; the rare earth disilicate is of a beta-monoclinic structure and / or a gamma-monoclinic structure; the space group of the beta-monoclinic structure is C2 / c; the space group of the gamma-monoclinic structure is P21 / c. The thermal barrier-environmental barrier coating material prepared by the invention is a multiphase material containing rare earth monosilicate and rare earth disilicate, 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; the material has more excellent performance when being applied to the fields of airspace engines, high-temperature gas turbines and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal barrier-environmental barrier coating materials, and in particular to thermal barrier-environmental barrier coating materials and preparation methods and applications thereof, thermal barrier-environmental barrier coatings and preparation methods thereof. Background Art

[0002] In order 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] The performance of traditional high-temperature alloys has reached its theoretical limit, and there is an urgent need for more high-temperature resistant alternative materials. Among them, ceramic fiber reinforced ceramic matrix composites (CMCs) have the greatest development potential. Although CMCs materials have many advantages over high-temperature alloys, such as high temperature resistance, low density, and strong high-temperature mechanical properties, there are still some problems that limit their further application in high-temperature gas environments. The matrix SiC material has a good antioxidant effect in a dry and high-temperature environment with oxygen. Its surface will be oxidized to form a dense SiO2 thin layer. This passivation oxidation restriction reaction plays a protective role for CMCs. However, in a water vapor environment, SiO2 will be lost rapidly, resulting in a sharp decrease in the performance of CMCs. To this end, researchers have found that depositing a layer of SiO2 coating in CMCs ceramics and then depositing a layer of Yb2Si2O7 or Y2Si2O7 coating can effectively improve the service temperature and life of CMCs. However, Yb2Si2O7 and Y2Si2O7 have high thermal conductivity and poor fracture toughness. In view of the above problems, it is necessary 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] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the present invention provides a thermal barrier-environmental barrier coating material and a preparation method and application thereof, and a thermal barrier-environmental barrier coating and a preparation method thereof, wherein the coating material is transformed into a composite material containing rare earth monosilicate and rare earth disilicate by adjusting the total amount and type of rare earth doping elements, and has 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] Wherein, the rare earth monosilicate has a monoclinic structure and a space group of C2 / m;

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

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

[0009] The invention provides a thermal barrier-environmental barrier coating material, which is composed of rare earth monosilicate and rare earth disilicate composite materials, and the rare earth monosilicate and rare earth disilicate have a specific spatial structure, so that the obtained thermal barrier-environmental barrier coating material has 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] Among them, RE is rare earth element; 0.33 <x<0.5。

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

[0013] According to an embodiment of the present invention, the percentages of the molar amount of Gd2O3 and Dy2O3 to the total molar amount of the rare earth oxide are x1 and x2 respectively;

[0014] Wherein, x1+x2≤30mol%;

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

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

[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] The second aspect of the present invention provides a method for preparing the thermal barrier-environmental barrier coating material according to the first aspect, comprising the following steps:

[0019] mixing silicon oxide and rare earth oxide to obtain a mixture 1;

[0020] The mixture 1 is subjected to a ball milling and a calcination to obtain a 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 adjusts the total amount and type of rare earth doping elements and the usage ratio of rare earth oxide and silicon oxide 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 of the first ball milling is 3-6 hours.

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

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

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

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

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

[0029] A third aspect of the present invention provides a method for preparing a thermal barrier-environmental barrier coating, comprising the following steps:

[0030] 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 is deposited or coated on the surface of a substrate to obtain the thermal barrier-environmental barrier coating.

[0031] Since the rare earth monosilicate and the rare earth disilicate are uniformly mixed in the thermal barrier-environmental barrier coating material prepared by the present invention, the prepared coating has uniform composition and fine grains, which is beneficial to improving the thermal cycle performance of the coating.

[0032] The fourth aspect of the present invention provides a thermal barrier-environmental barrier coating obtained according to the preparation method described in the third aspect.

[0033] A fifth aspect of the present invention provides an 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 aviation field and / or heavy-duty gas turbines.

[0034] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0036] Figure 1 The XRD patterns of the thermal barrier-environmental barrier coating materials prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention after calcination at 1400° C. for 100 h are shown;

[0037] Figure 2 The SEM images of the thermal barrier-environmental barrier coating materials prepared in Examples 1-3 of the present invention are shown. Among them, Figure a is a SEM image of the thermal barrier-environmental barrier coating material prepared in Example 1; Figure b is a SEM image of the thermal barrier-environmental barrier coating material prepared in Example 2; Figure c is a SEM image of the thermal barrier-environmental barrier coating material prepared in Example 3;

[0038] Figure 3 The SEM image of the thermal barrier-environmental barrier coating material prepared in Example 1 of the present invention is shown. DETAILED DESCRIPTION

[0039] 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 understood as limiting the present invention.

[0040] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0041] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0042] In order to make the present invention more easily understood, certain technical and scientific terms are specifically defined below. Unless otherwise clearly defined elsewhere in this document, all other technical and scientific terms used herein have the meanings commonly understood by those skilled in the art to which the present invention belongs.

[0043] In this document, the terms “include” or “comprising” are open expressions, that is, including the contents specified in the present invention but not excluding other contents.

[0044] As used herein, the terms "optionally", "optional" or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0045] 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;

[0046] Wherein, the rare earth monosilicate has a monoclinic structure and a space group of C2 / m;

[0047] The rare earth disilicate has a β-monoclinic structure and / or a γ-monoclinic structure;

[0048] The space group of the β-monoclinic structure is C2 / c; the space group of the γ-monoclinic structure is P21 / c.

[0049] The material has a quasi-eutectic structure with deflections and bridges between grains, so it has better toughness and lower thermal conductivity than single-phase materials.

[0050] 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 ;

[0051] Among them, RE is rare earth element; 0.33 <x<0.5。

[0052] According to a specific embodiment of the present invention, the value of x is not particularly limited. As some specific examples, x may be 0.34, 0.39, 0.44, 0.49, etc.

[0053] According to a specific embodiment of the present invention, the rare earth element is provided by a rare earth oxide, and the type of the rare earth oxide is not particularly limited. As some specific examples, the rare earth oxide includes Gd2O3, Dy2O3, Ho2O 3、 At least two of Y2O3, Er2O3, Yb2O3, Lu2O3 or Sc2O3.

[0054] According to a specific embodiment of the present invention, the percentages of the molar amount of Gd2O3 and Dy2O3 to the total molar amount of the rare earth oxide are x1 and x2 respectively;

[0055] Wherein, x1+x2≤30mol%;

[0056] The percentages of the molar amounts of Ho2O3, Y2O3, Er2O3, Yb2O3, Lu2O3 and Sc2O3 to the total molar amount of the rare earth oxides are y1, y2, y3, y4, y5 and y6 respectively;

[0057] Among them, y1+y2+y3+y4+y5+y6≥70mol%.

[0058] According to a specific embodiment of the present invention, the value of x1+x2 is not particularly limited. As some specific examples, the value of x1+x2 may 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 may be 70 mol%, 80 mol%, 90 mol%, 100 mol%, etc.

[0059] According to a specific embodiment 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 may be 30 μm, 50 μm, 70 μm, 90 μm, 110 μm, etc.

[0060] According to an embodiment of the present invention, the second aspect of the present invention provides a method for preparing the thermal barrier-environmental barrier coating material according to the first aspect, comprising the following steps:

[0061] mixing silicon oxide and rare earth oxide to obtain a mixture 1;

[0062] The mixture 1 is subjected to a ball milling and a calcination to obtain a mixture 2;

[0063] The mixture 2 is subjected to secondary ball milling, granulation, and secondary calcination to obtain the thermal barrier-environmental barrier coating material.

[0064] The type and structure of the crystal phase of the generated material can be changed by regulating the total amount and type of rare earth doping elements and the usage ratio of rare earth oxide and silicon oxide. By using the raw material ratio in the preparation method of the present invention, a rare earth monosilicate and rare earth disilicate composite material can be obtained, which has lower thermal conductivity and higher toughness than pure phase di-rare earth silicate, and has higher toughness and lower thermal expansion coefficient than pure phase rare earth monosilicate.

[0065] According to a specific embodiment of the present invention, the time of the first ball milling is 3-6 hours. As some specific examples, the time of the first ball milling can be 3 hours, 4 hours, 5 hours, 6 hours, etc. Specifically, the medium used in the first ball milling is not particularly limited, and zirconium oxide balls and alcohol, etc. can be used. After ball milling, separation treatment can be performed to obtain a precipitate, and the precipitate is ground, sieved and calcined once.

[0066] According to a specific embodiment of the present invention, the temperature of the primary calcination is 1000-1250°C. As some specific examples, the temperature of the primary calcination may be 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, 1250°C, etc.

[0067] According to a specific embodiment of the present invention, the time of the first calcination is 2-4 hours. As some specific examples, the time of the first calcination can be 2 hours, 3 hours, 4 hours, etc.

[0068] According to a specific embodiment of the present invention, the time of the secondary ball milling is 6-10 hours. As some specific examples, the time of the secondary ball milling can be 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, etc.

[0069] According to a specific embodiment of the present invention, the granulation includes granulating powder with a particle size of 200-300 meshes. The granulation method is not particularly limited, including but not limited to spray granulation.

[0070] According to a specific embodiment of the present invention, the temperature of the secondary calcination is 1350-1500°C. As some specific examples, the temperature of the secondary calcination may be 1350°C, 1400°C, 1450°C, 1500°C, etc.

[0071] 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.

[0072] According to a specific embodiment of the present invention, the preparation method may further include molding the thermal barrier-environmental barrier coating material for subsequent application. The molding process may be specifically a combination of pre-pressing and cold isostatic pressing.

[0073] According to a specific embodiment of the present invention, the preparation method further comprises: removing impurities from the silicon oxide and the rare earth oxide. The impurity removal method is not particularly limited. As some specific examples, the raw materials may be calcined at high temperature to remove adsorbed impurities such as water and carbon dioxide.

[0074] 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:

[0075] 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 is deposited or coated on the surface of a substrate to obtain the thermal barrier-environmental barrier coating.

[0076] Since the rare earth monosilicate and the rare earth disilicate are uniformly mixed in the thermal barrier-environmental barrier coating material prepared by the present invention, the prepared coating has uniform composition and fine grains, which is beneficial to improving the thermal cycle performance of the coating.

[0077] According to a specific embodiment of the present invention, the coating method is not particularly limited, and some specific examples include but are not limited to atmospheric plasma spraying.

[0078] According to a specific embodiment of the present invention, the fourth aspect of the present invention provides a thermal barrier-environmental barrier coating obtained according to the preparation method described in the third aspect.

[0079] According to a specific embodiment 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 aviation field and / or heavy-duty gas turbines.

[0080] The thermal barrier-environmental barrier coating material obtained by the present invention has excellent thermal insulation performance and mechanical toughness, and can meet the high-temperature protection requirements of hot end components such as aerospace engines and high-temperature gas turbines.

[0081] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0082] Example 1

[0083] The preparation method of the thermal barrier-environmental barrier coating material in this embodiment is as follows:

[0084] (a) Ho2O3, Er2O3, Y2O3, Yb2O3, Sc2O3 and SiO2 were calcined at 1100°C for 1 h to remove adsorbed impurities such as water and carbon dioxide;

[0085] (b) The dried Ho2O3, Er2O3, Y2O3, Yb2O3, Sc2O3 and SiO2 were heated to [(Ho 0.2Er 0.2 Y 0.2 Yb 0.2 Sc 0.2 )2O3] 0.4 -(SiO2) 0.6 Weigh the mixture in proportion to obtain mixture 1;

[0086] (c) subjecting the mixture 1 to a first ball milling, wherein the media for the first ball milling are zirconium oxide balls and alcohol, and the first ball milling time is 5 h;

[0087] (d) separating the slurry after the first ball milling, grinding and sieving the obtained blocks, and then calcining them once at a temperature of 1100° C. for 2 h to obtain a mixture 2;

[0088] (e) subjecting the mixture 2 to a secondary ball milling for 6 h, and then passing through a 200-mesh sieve;

[0089] (f) spray granulation, secondary calcination, calcination temperature is 1500 ° C, calcination time is 3 hours, and then sieving to screen out particles with a size of 30-70 μm;

[0090] (g) The particles prepared in step (f) were pre-pressed into a mold with a diameter of 15 mm at a pressure of 100 MPa; the obtained green body was kept at 200 MPa for 60 s by cold isostatic pressing, and then the block was calcined at 1600° C. for 10 h to obtain [(Ho 0.2 Er 0.2 Y 0.2 Yb 0.2 Sc 0.2 )2O3] 0.4 -(SiO2) 0.6 Used for subsequent performance testing.

[0091] The XRD spectrum of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows Figure 1 As shown in the SEM images Figure 2-3 The fracture toughness, structure, thermal conductivity and thermal expansion coefficient are shown in Table 1. Figure 1 As shown in Table 1, the thermal barrier-environmental barrier coating material prepared in this embodiment comprises rare earth monosilicate (monoclinic structure, space group C2 / m) and rare earth disilicate (β-monoclinic structure, space group C2 / c), 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 forms a quasi-eutectic structure. Figure 3 It can be seen that the crack showed multiple deflections and bridges during the expansion process, indicating that the thermal barrier-environmental barrier coating material prepared in this embodiment has high toughness.

[0092] Example 2

[0093] 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 that:

[0094] The raw materials in step (a) are Lu2O3, Gd2O3, Y2O3, Yb2O3 and SiO2. The chemical formula is [(Gd 0.25 Y 0.25 Yb 0.25 Lu 0.25 )2O3] 0.4 -(SiO2) 0.6 .

[0095] The XRD spectrum of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows Figure 1 As shown in the SEM images Figure 2 The fracture toughness, structure, thermal conductivity and thermal expansion coefficient are shown in Table 1. Figure 1 As shown in Table 1, the thermal barrier-environmental barrier coating material prepared in this embodiment comprises rare earth monosilicate (monoclinic structure, space group C2 / m) and rare earth disilicate (β-monoclinic structure, space group C2 / c), 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 forms a quasi-eutectic structure.

[0096] Example 3

[0097] 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 that:

[0098] The raw materials in step (a) are Lu2O3, Gd2O3, Y2O3, Yb2O3, 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 .

[0099] The XRD spectrum of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows Figure 1 As shown in the SEM images Figure 2 The fracture toughness, structure, thermal conductivity and thermal expansion coefficient are shown in Table 1. Figure 1As shown in Table 1, the thermal barrier-environmental barrier coating material prepared in this embodiment comprises rare earth monosilicate (monoclinic structure, space group C2 / m) and rare earth disilicate (β-monoclinic structure, space group C2 / c), 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 forms a quasi-eutectic structure.

[0100] Example 4

[0101] 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 that:

[0102] The raw materials in step (a) are Lu2O3, Gd2O3, Y2O3, Yb2O3, Ho2O3, Dy2O3, Er2O3, Sc2O3 and SiO2. The chemical formula is [(Gd 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 .

[0103] Example 5

[0104] 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 that:

[0105] The raw materials in step (a) are Lu2O3, Gd2O3 and SiO2. The chemical formula is [(Gd 1 / 4 Lu 3 / 4 )2O3] 0.4 -(SiO2) 0.6 .

[0106] Comparative Example 1

[0107] The 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 that:

[0108] The raw materials in step (a) are Y2O3 and SiO2, and the molar ratio is 1:2.

[0109] The XRD spectrum of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows Figure 1 The fracture toughness, structure, thermal conductivity and thermal expansion coefficient are shown in Table 1. Figure 1As can be seen from Table 1, the thermal barrier-environmental barrier coating material prepared in this comparative example is Y2Si2O7 with a γ-monoclinic structure.

[0110] Comparative Example 2

[0111] The 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 that:

[0112] The raw materials in step (a) are Yb2O3 and SiO2, and the molar ratio is 1:2.

[0113] The XRD spectrum of the thermal barrier-environmental barrier coating material prepared according to the above process is as follows Figure 1 The fracture toughness, structure, thermal conductivity and thermal expansion coefficient are shown in Table 1. Figure 1 As can be seen from Table 1, the thermal barrier-environmental barrier coating material prepared in this comparative example is Yb2Si2O7 with a β-monoclinic structure.

[0114] Test Case

[0115] The fracture toughness, structure, thermal conductivity and thermal expansion coefficient of the thermal barrier-environmental barrier coating materials prepared in the examples and comparative examples were tested, and the test method was as follows:

[0116] (1) Fracture toughness test of thermal barrier and environmental barrier coating materials:

[0117] According to national standards, the three-point bending method is used to measure the fracture toughness of the sample. The size of the sample is 20mm×4mm×2mm, and the wire cutting technology is used to pre-make the incision. The incision depth is about 2mm. The fracture toughness of the sample is measured using a universal testing machine.

[0118] (2) Structural testing of thermal barrier and environmental barrier coating materials:

[0119] The thermal barrier-environmental barrier coating materials prepared in the examples and comparative examples were calcined at 1400° C. for 100 h, and then their structures were analyzed using XRD spectra.

[0120] (3) Thermal conductivity test of thermal barrier-environmental barrier coating materials:

[0121] The thermal diffusivity (λ) of the samples was first tested by the laser flash apparatus (LFA), and then the specific heat capacity (C P ), and then the thermal conductivity (κ) of the material is calculated:

[0122] κ=ρC P λ

[0123] (4) Thermal expansion coefficient test of thermal barrier-environmental barrier coating materials:

[0124] The thermal expansion coefficient 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.

[0125] Table 1

[0126]

[0127]

[0128]

[0129] It can be seen from the data in Table 1 that 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, indicating that the thermal barrier-environmental barrier coating material prepared according to the method of the present invention has lower thermal conductivity and higher toughness than pure phase double rare earth silicate, and the thermal expansion coefficient is adjustable, and has better performance when applied to aerospace engines, high-temperature gas turbines and other fields.

[0130] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0131] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary 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 composite material comprising rare earth monosilicate and rare earth disilicate; Wherein, the rare earth monosilicate has a monoclinic structure and a space group of C2 / m; The rare earth disilicate has a β-monoclinic structure and / or a γ-monoclinic structure; The space group of the β-monoclinic structure is C2 / c; the space group of the γ-monoclinic structure is P21 / c.

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 ; Among them, RE is rare earth element; 0.33 <x<0.5; Optionally, the rare earth element is provided by rare earth oxides, and the rare earth oxides include Gd2O3, Dy2O3, Ho2O 3、 At least two of Y2O3, Er2O3, Yb2O3, Lu2O3 or Sc2O3.

3. The thermal barrier-environmental barrier coating material according to claim 2, characterized in that: The percentages of the molar amounts of Gd2O3 and Dy2O3 to the total molar amount of the rare earth oxides are x1 and x2 respectively; Wherein, x1+x2≤30mol%; The percentages of the molar amounts of Ho2O3, Y2O3, Er2O3, Yb2O3, Lu2O3 and Sc2O3 to the total molar amount of the rare earth oxides are y1, y2, y3, y4, y5 and y6 respectively; Among them, y1+y2+y3+y4+y5+y6≥70mol%.

4. 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.

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

6. The preparation method according to claim 5, characterized in that: The time of the first ball milling is 3-6h; Optionally, the primary calcination temperature is 1000-1250°C; Optionally, the primary calcination time is 2-4 hours.

7. The preparation method according to claim 5, characterized in that: The secondary ball milling time is 6-10h; Optionally, the secondary calcination temperature is 1350-1500°C; Optionally, the secondary calcination time is 3-4 hours.

8. 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 to 4 or the thermal barrier-environmental barrier coating material obtained by the preparation method according to any one of claims 5 to 7 is deposited or coated on the surface of a substrate to obtain the thermal barrier-environmental barrier coating.

9. A thermal barrier-environmental barrier coating, characterized in that: The thermal barrier-environmental barrier coating is obtained by the preparation method described in claim 8.

10. Use of the thermal barrier-environmental barrier coating material according to any one of claims 1 to 4 or the thermal barrier-environmental barrier coating material obtained by the preparation method according to any one of claims 5 to 7 in the aviation field and / or heavy-duty gas turbines.

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