Ceramic materials, methods of making and using the same

Abstract

The application relates to the technical field of ceramic materials, in particular to a ceramic material and a preparation method and application thereof. x Hf y )2O7, wherein Re comprises one or more of Y, Er, Yb and Lu, 0<=x<=0.95, 0.05<=y<=1, and x+y=1. The ceramic material has excellent sintering resistance and mechanical properties.

Description

Technical Field

[0001] This application relates to the field of ceramic materials technology, and in particular to a ceramic material, its preparation method, and its application. Background Technology

[0002] Aerospace equipment typically operates at extremely high temperatures, especially the hot ends of ramjet engines, aerospace engines, and high-temperature gas turbines. To ensure these structural components can operate for extended periods at these extreme temperatures, a thermal barrier coating with excellent heat insulation capabilities is required on their surface. Among all high-temperature resistant materials, ceramic oxides are the best choice for thermal barrier coatings. Traditional YSZ (7wt%–8wt% Y2O3 partially stabilized ZrO2) ceramic materials have become the most widely used and mature thermal barrier coating material due to their superior performance. However, during long-term service at high temperatures (1200℃ and above), due to differences in energy and concentration, spontaneous migration of materials into microcracks and micropores occurs within the ceramic layer of the thermal barrier coating. This leads to the gradual healing of microcracks and micropores, resulting in a decrease in porosity and an increase in density, significantly degrading its mechanical and thermal properties. Furthermore, YSZ ceramic materials have a relatively high intrinsic thermal conductivity (2.6 W / m²). -1 K -1 At 800℃, sintering can easily occur, which will lead to a significant decrease in its heat insulation and protection performance. Summary of the Invention

[0003] Therefore, it is necessary to provide a ceramic material that can improve sintering resistance and mechanical properties, as well as its preparation method and application.

[0004] In a first aspect, this application provides a ceramic material, the chemical formula of which is LaRe(Zr) x Hf y )2O7, wherein Re includes one or more of Y, Er, Yb and Lu, 0≤x≤0.95, 0.05≤y≤1, and x+y=1.

[0005] In some embodiments, the ceramic material comprises a fluorite phase and a pyrochlore phase, wherein the chemical formula of the fluorite phase is A. a B (1-a) O (2-a / 2) The chemical formula of the pyrochlore phase is A₂B₂O₇, where A is Re or La, B is Zr or Hf, and 0.4 <a<0.6。

[0006] In some embodiments, the ceramic material has a quasi-eutectic structure, which is composed of LaO 1.5 ReO 1.5 ZrO2 and HfO2 are formed.

[0007] In some embodiments, the ceramic material comprises, by molar percentage, the following components:

[0008] LaO 1.5 25 mol% ~ 25 mol%, ReO 1.5 25 mol%–25 mol%, ZrO2 0 mol%–47.5 mol%, and HfO2 2.5 mol%–50 mol%.

[0009] Secondly, this application provides a method for preparing a ceramic material as described in the first aspect, comprising the following steps:

[0010] Re2O3, La2O3, HfO2 and ZrO2 are dispersed in a solvent to form a mixed slurry;

[0011] The mixed slurry is separated to obtain a solid material, and the solid material is calcined to form ceramic powder, thereby preparing the ceramic material.

[0012] In some embodiments, the molar ratio of Re2O3, La2O3, HfO2 and ZrO2 is 1:1:(0.1-2):(0-1.9).

[0013] In some embodiments, after dispersing Re2O3, La2O3, HfO2 and ZrO2 in a solvent, a ball milling step is further included;

[0014] Optionally, the ball mill rotates at a speed of 200 rpm / min to 300 rpm / min for a time of 5 h to 10 h.

[0015] In some embodiments, the preparation method satisfies at least one of the following characteristics:

[0016] 1) The calcination temperature of the solid material is 1250℃~1400℃, and the time is 1h~3h;

[0017] 2) The particle size of the ceramic powder is 200-300 mesh.

[0018] In some embodiments, the method further includes the steps of ball milling and calcining the ceramic powder;

[0019] Optionally, the ball milling of the ceramic powder is performed at a speed of 200 rpm / min to 300 rpm / min for a time of 5 h to 10 h.

[0020] Optionally, the calcination temperature of the ceramic powder is 1450℃~1700℃, and the time is 2h~10h.

[0021] In some embodiments, after calcining the ceramic powder, the method further includes granulating the calcined ceramic powder to form ceramic particles and calcining the ceramic particles.

[0022] Optionally, the particle size of the ceramic particles is 30 μm to 110 μm;

[0023] Optionally, the calcination temperature of the ceramic particles is 1250℃~1400℃, and the time is 1h~3h.

[0024] Thirdly, this application provides a device including a device body and a thermal barrier coating formed on the surface of the device body, wherein the material of the thermal barrier coating includes the ceramic material described in the first aspect.

[0025] This application forms a matrix with the chemical formula LaRe(Zr2O7) by doping HfO2 into a LaReZr2O7 matrix, which has excellent mechanical properties and phase stability. x Hf y The ceramic material provided in this application has a high melting point, low thermal conductivity, and high coefficient of thermal expansion. Compared with traditional ceramic materials used in thermal barrier coatings (such as YSZ), its thermal conductivity is significantly reduced. Furthermore, by introducing Hf, the shrinkage rate and average grain size of the ceramic material can be reduced, improving its resistance to sintering and enabling long-term use in environments above 1300°C. It also imparts a lower thermal conductivity. Therefore, the thermal barrier coating formed using the ceramic material provided in this application exhibits excellent resistance to sintering and superior mechanical properties, thus meeting the service requirements of equipment. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 The images show the XRD patterns of the bulk ceramic materials formed by the ceramic materials prepared in Examples 1-5 and Comparative Example 1.

[0028] Figure 2 The graph shows the thermal conductivity test results of the bulk ceramic materials obtained in Examples 1-4 and Comparative Example 1.

[0029] Figure 3 Scanning electron microscope (SEM) images of the bulk ceramic materials formed by Examples 1-4 and Comparative Example 1. Detailed Implementation

[0030] To facilitate understanding of this application, a more complete description is provided below. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0032] the term:

[0033] As used herein, the term "and / or" encompasses any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" includes three parallel options: A, B, and "a combination of A and B".

[0034] In this document, unless otherwise stated, "one or more" means any one of the listed items or any combination of the listed items. Similarly, "one or more" and other instances of "one or more" are to be understood in the same way unless otherwise stated.

[0035] In this document, terms such as "further," "even further," "especially," "for example," "as," "example," and "exemplary" are used for descriptive purposes to indicate a connection in the coverage of different technical solutions presented earlier and later. However, they should not be construed as limitations on the preceding technical solution or on the scope of protection of this document. Unless otherwise specified, A (as in B) indicates that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0036] In this document, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "present" or "absent." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. In this application, descriptions such as "optionally contains" and "optionally includes" indicate "contains or does not contain." "Optional component X" indicates whether component X exists or does not exist, or whether component X is contained or not.

[0037] In this document, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood as not constituting a closed limitation on quantity.

[0038] In this article, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions that include the listed features.

[0039] In this document, when referring to numerical intervals (i.e., numerical ranges), unless otherwise specified, the distribution of selectable values ​​within a numerical interval is considered continuous, and includes the two endpoints (i.e., the minimum and maximum values) of the numerical interval, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in this numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, and other numerical interval types.

[0040] In this document, for methods involving multiple steps, unless otherwise explicitly stated herein, there is no strict order constraint on the execution of these steps; they may be executed in any order other than those described. Moreover, any step may include multiple sub-steps or multiple stages, which are not necessarily completed at the same time, but may be executed at different times, and their execution order is not necessarily sequential, but may be executed in turn, alternately, or simultaneously with other steps or parts of the sub-steps or stages of other steps.

[0041] Traditional ceramic materials used in thermal barrier coatings have high thermal conductivity and are prone to sintering, resulting in poor thermal insulation performance. Furthermore, their susceptibility to microcrack and micropore healing leads to low mechanical properties. Therefore, this application provides a ceramic material to address these problems.

[0042] In a first aspect, this application provides a ceramic material, the chemical formula of which is LaRe(Zr) x Hf y)2O7, where Re includes one or more of Y, Er, Yb, and Lu, 0 ≤ x ≤ 0.95, 0.05 ≤ y ≤ 1, and x + y = 1.

[0043] In this application, by doping HfO2 into the LaReZr2O7 matrix with excellent mechanical properties and phase stability, a ceramic material with the chemical formula LaRe(Zr x Hf y )2O7 is formed. The ceramic material provided by this application has a high melting point, low thermal conductivity, and high thermal expansion coefficient. Compared with traditional ceramic materials used for thermal barrier coatings (such as YSZ), the thermal conductivity is significantly reduced. In addition, by introducing the Hf element, the shrinkage rate and average grain size of the ceramic material can be reduced, its anti-sintering ability can be improved, it can be used in an environment above 1300 °C for a long time, and at the same time, a lower thermal conductivity can be given to the ceramic material. Therefore, the thermal barrier coating formed by using the ceramic material provided by this application has excellent anti-sintering ability and mechanical properties, thus being able to meet the service requirements of the equipment.

[0044] In some embodiments, 0 < x ≤ 0.95, 0.05 ≤ y < 1.

[0045] In some embodiments, the chemical formula of the ceramic material is LaYb(Zr 0.9 Hf 0.1 )2O7, LaYb(Zr 0.8 Hf 0.2 )2O7, LaYb(Zr 0.7 Hf 0.3 )2O7, LaYb(Zr 0.5 Hf 0.5 )2O7 or LaYbZrHfO7.

[0046] In some embodiments, the ceramic material includes a fluorite phase and a pyrochlore phase. The chemical formula of the fluorite phase is A a B (1-a) O (2-a / 2) , and the chemical formula of the pyrochlore phase is A2B2O7, where A is Re or La, B is Zr or Hf, and 0.4 < a < 0.6. By doping HfO2 into the LaReZr2O7 matrix, a LaRe(Zr x Hf y )2O7 ceramic material with a two-phase structure of an ordered pyrochlore phase and a disordered fluorite phase is formed. The simultaneous presence of the two-phase structure can inhibit the growth of grains in the ceramic material, thereby reducing the grain size (the average grain size can be reduced to at least below 1.2 μm), and further improving the anti-sintering ability of the ceramic material.

[0047] In some embodiments, the ceramic material has a quasi-eutectic structure, which is composed of LaO 1.5 ReO 1.5 ZrO2 and HfO2 are formed.

[0048] The ceramic material in this application is a quasi-eutectic ceramic material, that is, during the solid-state reaction, zirconates of La and Re with large differences in ionic radii decompose due to huge lattice stress to form a two-phase mixture of pyrochlore and fluorite, thus forming a quasi-eutectic structure. By forming a quasi-eutectic structure, the grains in the ceramic material can be further refined, thereby improving the anti-sintering properties and mechanical properties of the ceramic material.

[0049] In some embodiments, the ceramic material comprises, by molar percentage, the following components:

[0050] LaO 1.5 25 mol% ~ 25 mol%, ReO 1.5 The molar percentages of each component in the ceramic material, especially the molar percentage of HfO2, are controlled within this range. This ensures that the ceramic material is composed of both pyrochlore and fluorite phases, thereby effectively controlling the anti-sintering ability of the ceramic material and ensuring that the ceramic material has extremely low thermal conductivity.

[0051] Furthermore, the molar percentage of ZrO2 is 2.5 mol% to 47.5 mol%. Preferably, LaO2... 1.5 The molar percentage is 25 mol%, ReO 1.5 The molar percentages of ZrO2 and HfO2 are 25 mol%, 35 mol%, and 15 mol%, respectively.

[0052] Secondly, this application provides a method for preparing a ceramic material as described in the first aspect, comprising the following steps:

[0053] Re2O3, La2O3, HfO2 and ZrO2 are dispersed in a solvent to form a mixed slurry;

[0054] The mixed slurry is separated to obtain a solid material, and the solid material is calcined to form ceramic powder, thereby preparing the ceramic material.

[0055] In some embodiments, the molar ratio of Re₂O₃, La₂O₃, HfO₂, and ZrO₂ is 1:1:(0.1–2):(0–1.9). Further, the molar ratio of Re₂O₃, La₂O₃, HfO₂, and ZrO₂ is 1:1:(0.1–2):(0.1–1.9). By controlling the mass ratio of each metal oxide within the above range, it is possible to ensure that the formed ceramic material has a specific molar percentage of LaO₂. 1.5 ReO 1.5 ZrO2 and HfO2 are used to ensure the formation of a stable quasi-eutectic structure and improve the anti-sintering performance.

[0056] In some embodiments, after dispersing Re2O3, La2O3, HfO2, and ZrO2 in the solvent, a ball milling step is further included. By employing ball milling, the individual metal oxides can be uniformly dispersed in the solvent, forming a homogeneous mixed slurry.

[0057] It is understandable that zirconia balls can be added as milling media during the ball milling process. The mass ratio of the zirconia balls to the total mass of Re2O3, La2O3, HfO2 and ZrO2 can be (10-20):1.

[0058] In some embodiments, the ball mill rotates at a speed of 200 rpm / min to 300 rpm / min for a time of 5 h to 10 h.

[0059] It is understood that the solvent can be selected from any solvent known in the field of ceramic material preparation, and can be an organic solvent or an inorganic solvent. For example, the solvent may include ethanol (alcohol) or water.

[0060] To remove impurities such as water or carbon dioxide from the various metal oxides, some embodiments include a step of calcining Re2O3, La2O3, HfO2, and ZrO2 before dispersing them in a solvent. The calcination temperature can be 1000℃ to 1200℃, and the time can be 1 hour to 3 hours.

[0061] It is understood that the method used to separate the mixed slurry into solid material can be a commonly used separation method in the field of solid-liquid separation. As an example, the method for separating the mixed slurry into solid material can be centrifugation.

[0062] In some embodiments, the solid material is calcined at a temperature of 1250°C to 1400°C for a time of 1 hour to 3 hours.

[0063] It is understandable that, in order to ensure uniform calcination, the solid material is ground and sieved before calcination.

[0064] In some embodiments, the particle size of the ceramic powder is 200-300 mesh.

[0065] In some embodiments, the method further includes the steps of ball milling and calcining the ceramic powder.

[0066] In some embodiments, the ball milling of the ceramic powder is performed at a speed of 200 rpm / min to 300 rpm / min for a time of 5 h to 10 h.

[0067] In some embodiments, the ceramic powder is calcined at a temperature of 1450℃ to 1700℃ for a time of 2h to 10h.

[0068] It is understood that, in order to obtain powder with the target particle size, a sieving step may be included before calcining the ceramic powder.

[0069] In some embodiments, after calcining the ceramic powder, the process further includes granulating the calcined ceramic powder to form ceramic particles and then calcining the ceramic particles. Granulating the ceramic powder facilitates storage and the formation of a thermal barrier coating.

[0070] In some implementations, the granulation method is spray granulation.

[0071] In some embodiments, the particle size of the ceramic particles is 30 μm to 110 μm.

[0072] In some embodiments, the ceramic particles are calcined at a temperature of 1250°C to 1400°C for a time of 1 hour to 3 hours.

[0073] In one specific embodiment, the method for preparing ceramic materials includes the following steps:

[0074] S100: Calcination of Re2O3, La2O3, HfO2 and ZrO2 to remove impurities;

[0075] S200: Disperse the calcined Re2O3, La2O3, HfO2 and ZrO2 from step S100 in a solvent, and ball mill them to form a mixed slurry;

[0076] S300: Separate the mixed slurry obtained in step S200, and grind, sieve and calcine the solid material to obtain mixed powder;

[0077] S400: The mixed powder obtained in step S300 is ball-milled, sieved, and calcined to prepare ceramic powder;

[0078] S500: Granulate and calcine the ceramic powder obtained in step S400 to obtain ceramic particles.

[0079] It is understood that the ceramic material obtained in this application can be a powder or a granular material.

[0080] Thirdly, this application provides a device including a device body and a thermal barrier coating formed on the surface of the device body, wherein the material of the thermal barrier coating includes the ceramic material described in the first aspect.

[0081] In this application, the method for forming the thermal barrier coating is not limited; any process commonly used in the field of coating preparation can be selected. For example, an atmospheric plasma spraying process can be used to form the thermal barrier coating.

[0082] It is understood that the equipment described in this application may include aerospace and marine equipment, military equipment, mechanical equipment, etc.

[0083] The present application will be further described in detail below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0084] In the specific embodiments described below, the measurement parameters involving raw material components may have slight deviations within the weighing accuracy range unless otherwise specified. Temperature and time parameters are subject to acceptable deviations due to instrument testing accuracy or operational precision.

[0085] Example 1

[0086] 1) Calcine Yb2O3, La2O3, HfO2 and ZrO2 at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they adsorbed;

[0087] 2) Weigh out the Yb₂O₃, La₂O₃, HfO₂, and ZrO₂ treated in step 1) in a molar ratio of 1:1:0.2:1.8 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0088] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 2 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaYb(Zr) 0.9 Hf 0.1 )2O7 ceramic material. In LaYb(Zr 0.9 Hf 0.1 In LaO2 ceramic materials, 1.5 The molar percentage is 25 mol%, YbO 1.5 The molar percentages are 25 mol%, ZrO2 45 mol%, and HfO2 5 mol%.

[0089] Example 2

[0090] 1) Calcine Yb2O3, La2O3, HfO2 and ZrO2 at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they adsorbed;

[0091] 2) Weigh out the Yb₂O₃, La₂O₃, HfO₂, and ZrO₂ treated in step 1) in a molar ratio of 1:1:0.4:1.6 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0092] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 2 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaYb(Zr) 0.8 Hf 0.2 )2O7 ceramic material. In LaYb(Zr 0.8 Hf 0.2 In LaO2 ceramic materials, 1.5 The molar percentage is 25 mol%, YbO 1.5 The molar percentages are 25 mol%, ZrO2 40 mol%, and HfO2 10 mol%.

[0093] Example 3

[0094] 1) Calcine Yb2O3, La2O3, HfO2 and ZrO2 at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they adsorbed;

[0095] 2) Weigh out the Yb₂O₃, La₂O₃, HfO₂, and ZrO₂ treated in step 1) according to a molar ratio of 1:1:0.6:1.4 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0096] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 2 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaYb(Zr) 0.7 Hf 0.3 )2O7 ceramic material. In LaYb(Zr 0.7 Hf 0.3 In LaO2 ceramic materials, 1.5 The molar percentage is 25 mol%, YbO 1.5 The molar percentages are 25 mol%, ZrO2 15 mol%, and HfO2 35 mol%.

[0097] Example 4

[0098] 1) Calcine Yb2O3, La2O3, HfO2 and ZrO2 at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they adsorbed;

[0099] 2) Weigh out the Yb₂O₃, La₂O₃, HfO₂, and ZrO₂ treated in step 1) according to a molar ratio of 1:1:0.8:1.2 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0100] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 5 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaYb(Zr) 0.6 Hf 0.4 )2O7 ceramic material. In LaYb(Zr 0.6 Hf 0.4 In LaO2 ceramic materials, 1.5 The molar percentage is 25 mol%, YbO 1.5The molar percentages are 25 mol%, ZrO2 30 mol%, and HfO2 20 mol%.

[0101] Example 5

[0102] 1) Calcine Yb2O3, La2O3, HfO2 and ZrO2 at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they adsorbed;

[0103] 2) Weigh out the Yb₂O₃, La₂O₃, HfO₂, and ZrO₂ treated in step 1) in a molar ratio of 1:1:1:1 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0104] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 2 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaYb(Zr) 0.5 Hf 0.5 )2O7 ceramic material. In LaYb(Zr 0.5 Hf 0.5 In LaO2 ceramic materials, 1.5 The molar percentage is 25 mol%, YbO 1.5 The molar percentages are 25 mol%, ZrO2 molar percentages are 25 mol%, and HfO2 molar percentages are 25 mol%.

[0105] Example 6

[0106] The preparation method in this embodiment is basically the same as that in Example 1, except that the molar ratio of Yb2O3, La2O3, HfO2 and ZrO2 is adjusted to make LaYb(ZrO2)2O3(Hf ... 0.9 Hf 0.1 The molar percentage of HfO2 in the 2O7 ceramic material is 1 mol%.

[0107] Example 7

[0108] The preparation method in this embodiment is basically the same as that in Example 1, except that Y2O3 is used instead of Yb2O3. The specific steps are as follows:

[0109] 1) Calcine Y2O3, La2O3, HfO2 and ZrO2 at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they adsorbed;

[0110] 2) Weigh out the Y₂O₃, La₂O₃, HfO₂, and ZrO₂ treated in step 1) in a molar ratio of 1:1:0.2:1.8 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0111] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 2 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaY(Zr) 0.9 Hf 0.1 )2O7 ceramic material. In LaY(Zr 0.9 Hf 0.1 In LaO2 ceramic materials, 1.5 The molar percentage is 25 mol%, YO 1.5 The molar percentages are 25 mol%, ZrO2 45 mol%, and HfO2 5 mol%.

[0112] Example 8

[0113] The preparation method in this embodiment is basically the same as that in Example 1, except that Er2O3 is used instead of Yb2O3. The specific steps are as follows:

[0114] 1) Er2O3, La2O3, HfO2 and ZrO2 were calcined at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they had adsorbed;

[0115] 2) Weigh the Er₂O₃, La₂O₃, HfO₂, and ZrO₂ treated in step 1) according to a molar ratio of 1:1:0.2:1.8 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0116] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 2 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaEr(Zr) 0.9 Hf 0.1 )2O7 ceramic material. In LaEr(Zr 0.9 Hf 0.1 In LaO2 ceramic materials, 1.5The molar percentage is 25 mol%, ErO 1.5 The molar percentages are 25 mol%, ZrO2 45 mol%, and HfO2 5 mol%.

[0117] Example 9

[0118] The preparation method in this embodiment is basically the same as that in Example 1, except that Lu2O3 is used instead of Yb2O3. The specific steps are as follows:

[0119] 1) Calcine Lu2O3, La2O3, HfO2 and ZrO2 at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they adsorbed;

[0120] 2) Weigh the Lu₂O₃, La₂O₃, HfO₂, and ZrO₂ treated in step 1) according to a molar ratio of 1:1:0.2:1.8 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0121] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 2 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaLu(Zr) 0.9 Hf 0.1 )2O7 ceramic material. In LaLu(Zr 0.9 Hf 0.1 In LaO2 ceramic materials, 1.5 The molar percentage is 25 mol%, LuO 1.5 The molar percentages are 25 mol%, ZrO2 45 mol%, and HfO2 5 mol%.

[0122] Comparative Example 1

[0123] The preparation method of Comparative Example 1 is basically the same as that of Example 1, except that HfO2 was not doped. The specific steps are as follows:

[0124] 1) Calcine Yb2O3, La2O3 and ZrO2 at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they adsorbed;

[0125] 2) Weigh out the Yb₂O₃, La₂O₃, and ZrO₂ treated in step 1) in a molar ratio of 1:1:2 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0126] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 2 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaYbZr2O7 ceramic material. In the LaYbZr2O7 ceramic material, LaO 1.5 The molar percentage is 25 mol%, YbO 1.5 The molar percentage is 25 mol%, and the molar percentage of ZrO2 is 50 mol%.

[0127] Comparative Example 2

[0128] The preparation method of Comparative Example 2 is basically the same as that of Example 1, except that CeO2 is used instead of HfO2. The specific steps are as follows:

[0129] 1) Calcine Yb2O3, La2O3, CeO2 and ZrO2 at 1100℃ for 3h to remove impurities such as water and carbon dioxide that they adsorbed;

[0130] 2) Weigh out the Yb₂O₃, La₂O₃, CeO₂, and ZrO₂ treated in step 1) in a molar ratio of 1:1:0.2:1.8 to form a first mixed powder. Then, mix the first mixed powder with ethanol to form a mixed slurry. The mass ratio of zirconia balls to the mixed powder in the ball milling process is 15:1, and the ball milling speed is 250 rpm / min.

[0131] 3) The mixed slurry was separated to obtain blocky solids. The obtained blocky solids were ground, sieved, and calcined at 1250℃ for 2 hours to form a second mixed powder. The second mixed powder was ball-milled at 250 rpm / min, sieved, and calcined at 1500℃ for 5 hours to obtain LaYb(Zr) 0.9 Ce 0.1 )2O7 ceramic material. In LaYb(Zr 0.9 Ce 0.1 In LaO2 ceramic materials, 1.5 The molar percentage is 25 mol%, YbO 1.5 The molar percentages are 25 mol%, ZrO2 45 mol%, and CeO2 5 mol%.

[0132] Performance testing:

[0133] The ceramic materials obtained in Examples 1-9 and Comparative Examples 1 and 2 were respectively made into blocks with a diameter of 15 mm. Relevant performance tests were then performed on them.

[0134] 1) XRD test: The bulk ceramic materials formed in Examples 1-5 and Comparative Example 1 were calcined at 1600℃ for 10 hours, and their XRD patterns were tested as follows. Figure 1 As shown. By Figure 1 It is known that the ceramic materials prepared in each embodiment contain two phases, namely fluorite phase and pyrochlore phase, indicating that the ceramic materials provided in this application have a quasi-eutectic structure.

[0135] 2) Thermal conductivity: The density of each block was measured using the water displacement method. Subsequently, the thermal diffusivity of the blocks was tested using the laser scintillation method, and the thermal conductivity of each block was calculated based on the specific heat capacity of each sample at different temperatures (400℃~800℃). The test results are shown in Table 1. The thermal conductivity test results of the ceramic materials prepared in Examples 1-4 and Comparative Example 1 are shown in the figure below. Figure 2 As shown.

[0136] 3) Shrinkage rate: After calcining each block at 1500℃ for 5 hours, the shrinkage rate of the blocks was measured using vernier calipers. The test results are shown in Table 1.

[0137] 4) Average grain size: After calcining each of the prepared bulk materials at 1600℃ for 10 h, the average grain size of each bulk material was characterized by scanning electron microscopy (SEM). The test results are shown in Table 1. SEM images are shown below. Figure 3 As shown; wherein, the scanning electron microscope (SEM) images of the ceramic materials prepared in Examples 1-4 and Comparative Example 1 are respectively Figure 3 (b) Figure 3 (c) Figure 3 (d) Figure 3 (e) and Figure 3 As shown in (a).

[0138] 5) The hardness and fracture toughness of each block were tested by indentation method.

[0139] Table 1

[0140]

[0141]

[0142] As shown in Table 1 above, the ceramic material provided in this application not only possesses a high melting point (2200℃) and high phase stability, but also exhibits a thermal conductivity that is at least 30% lower than that of traditional YSZ materials, indicating its superior thermal stability and insulation performance. Furthermore, it demonstrates excellent anti-sintering properties. Therefore, the heat treatment temperature of the thermal barrier coating made from the ceramic material provided in this application can reach over 1400℃, demonstrating that the ceramic material provided in this application can be used for extended periods in environments exceeding 1300℃, exhibiting good practicality.

[0143] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0144] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification can be used to interpret the scope of the claims.

Claims

1. A ceramic material, characterized in that, The chemical formula of the ceramic material is LaRe(Zr) x Hf y )2O7, wherein Re includes one or more of Y, Er, Yb and Lu, 0 < x ≤ 0.95, 0.05 ≤ y ≤ 1, and x + y = 1; The ceramic material comprises, by molar percentage, the following components: LaO 1.5 25 mol%, ReO 1.5 25 mol%, ZrO2 2.5 mol%~47.5 mol%, and HfO2 2.5 mol%~50 mol%; The ceramic material comprises a fluorite phase and a pyrochlore phase, wherein the chemical formula of the fluorite phase is A. a B (1-a) O (2-a / 2) The chemical formula of the pyrochlore phase is A₂B₂O₇, where A is Re or La, B is Zr or Hf, and 0.4 <a<0.6; The ceramic material has a quasi-eutectic structure, which is composed of LaO 1.5 ReO 1.5 ZrO2 and HfO2 are formed.

2. The ceramic material as described in claim 1, characterized in that, The ceramic material comprises, by molar percentage, the following components: LaO 1.5 25 mol%, ReO 1.5 25 mol%, ZrO2 35 mol%, and HfO2 15 mol%.

3. A method for preparing a ceramic material as described in any one of claims 1 to 2, characterized in that, Includes the following steps: Re2O3, La2O3, HfO2 and ZrO2 are dispersed in a solvent to form a mixed slurry; The mixed slurry is separated to obtain a solid material, and the solid material is calcined to form ceramic powder, thereby preparing the ceramic material.

4. The preparation method according to claim 3, characterized in that, The molar ratio of Re2O3, La2O3, HfO2 and ZrO2 is 1:1:(0.1~2):(0~1.9).

5. The preparation method according to claim 3, characterized in that, After dispersing Re2O3, La2O3, HfO2 and ZrO2 in the solvent, the process further includes a ball milling step.

6. The preparation method according to claim 5, characterized in that, The ball mill operates at a speed of 200 rpm / min to 300 rpm / min for 5 h to 10 h.

7. The preparation method according to claim 3, characterized in that, It meets at least one of the following characteristics: 1) The calcination temperature of the solid material is 1250℃~1400℃, and the time is 1h~3h; 2) The particle size of the ceramic powder is 200~300 mesh.

8. The preparation method according to any one of claims 3 to 7, characterized in that, It also includes the steps of ball milling and calcining the ceramic powder.

9. The preparation method according to claim 8, characterized in that, The ball milling of the ceramic powder is performed at a speed of 200 rpm / min to 300 rpm / min for a time of 5 h to 10 h.

10. The preparation method according to claim 8, characterized in that, The ceramic powder is calcined at a temperature of 1450℃ to 1700℃ for a time of 2 hours to 10 hours.

11. The preparation method according to claim 8, characterized in that, After calcining the ceramic powder, the process further includes granulating the calcined ceramic powder to form ceramic particles and calcining the ceramic particles.

12. The preparation method according to claim 11, characterized in that, The ceramic particles have a particle size of 30μm to 110μm.

13. The preparation method according to claim 11, characterized in that, The ceramic particles are calcined at a temperature of 1250℃ to 1400℃ for a time of 1 hour to 3 hours.

14. A device, characterized in that, It includes a device body and a thermal barrier coating formed on the surface of the device body, wherein the material of the thermal barrier coating includes the ceramic material as described in any one of claims 1 to 2.

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