A non-equidistantly doped rare earth cerium zirconate thermal barrier coating material and its preparation method

Abstract

The present invention discloses a non-equiatomic doped rare earth zirconate thermal barrier coating material containing Ce and a preparation method thereof. The present invention relates to the technical field of thermal barrier coating materials. The chemical composition formula of the thermal barrier coating material of the present invention is (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7. Preparation method: S1, weighing metal sources according to the chemical composition formula to prepare a solution; S2, preparing materials by a reverse co-precipitation method; S3, pre-sintering and then sintering the powder to obtain the thermal barrier coating material. According to the calculation of the atomic size difference, the present invention prepares a single-phase structure with stable structure at high temperature under the condition of satisfying the formation of a single-phase solid solution. Under the condition of simultaneously satisfying low thermal conductivity and high thermal expansion performance, the mechanical properties such as hardness, elastic modulus, fracture toughness and brittleness are significantly improved, thereby promoting the practical application of the rare earth zirconate thermal barrier coating material containing Ce in the field of thermal barrier coating materials.

Description

Technical Field

[0001] The invention relates to the technical field of thermal barrier coating materials, and in particular to a non-isotropically doped Ce-containing rare earth zirconate thermal barrier coating material and a preparation method thereof. Background Art

[0002] Thermal barrier coatings are used on the surface of alloy substrates of turbine blades in aircraft engines or internal combustion engines to provide heat insulation, isolating the alloy component substrate from high-temperature combustion gas, reducing the substrate temperature, and allowing turbine blades to operate at high temperatures, thereby improving engine thermal efficiency (more than 60%) and extending service life. The currently widely used 8YSZ coating will undergo phase change and sintering when its service temperature is higher than 1200°C, and cannot meet the needs of the next generation of high thrust-to-weight ratio aircraft engines. High-temperature phase stability is one of the basic properties of new thermal barrier coating ceramic materials used to replace traditional YSZ ceramic materials.

[0003] The zirconate material system has low thermal conductivity, large thermal expansion coefficient, good sintering resistance, high temperature phase stability and other properties. It is currently the most promising thermal barrier coating ceramic material to replace 8YSZ. However, the thermal expansion properties and mechanical properties of zirconate material system thermal barrier coating ceramic materials still limit their use in the field of thermal barrier coating materials. In order to alleviate the thermal stress concentration caused by the mismatch of thermal expansion coefficients of thermal barrier coatings, which leads to coating peeling, the most effective measure is to increase the thermal expansion coefficient of the ceramic layer as much as possible and reduce the difference in linear expansion coefficient between it and the bonding layer. In addition, in order to improve the stress-strain tolerance of the thermal barrier coating ceramic layer material and avoid various stress concentrations that cause coating failure, the ceramic layer should be guaranteed to have a higher hardness, a lower elastic modulus, a higher fracture toughness and a lower brittleness index. Summary of the invention

[0004] The object of the present invention is to address the above-mentioned deficiencies in the prior art and to propose a non-isotropically doped Ce-containing rare earth zirconate thermal barrier coating material and a preparation method thereof having good high-temperature phase stability, lower thermal conductivity, elastic modulus and brittleness index, high thermal expansion coefficient, higher hardness and higher fracture toughness.

[0005] The present invention discloses a non-isotropically doped Ce-containing rare earth zirconate thermal barrier coating material, the chemical composition of which is as follows: 0.1 Sc 0.1 Dy 0.2 Sm 0.2 G 0.2 Yb 0.2 )2Zr2O7.

[0006] The preparation method of the non-isotropically doped Ce-containing rare earth zirconate thermal barrier coating material of the present invention comprises the following steps:

[0007] S1, rare earth source and zirconium source according to (Ce0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 in the molecular formula for batching and mixing to prepare a solution;

[0008] S2, using the reverse co-precipitation method, dropwise add the solution obtained in step S1 into ammonia water and continuously stir;

[0009] S3, centrifuge, wash and dry the flocculent precipitate obtained in step S2;

[0010] S4, preheat the dried mixed powder obtained in step S3 for a period of time to obtain a mixed heat-treated powder, and sinter the preheated mixed powder in a muffle furnace for a period of time to obtain a rare earth zirconate thermal barrier coating powder.

[0011] Further, during the reverse co-precipitation titration in step S2, dropwise add the acidic solution into ammonia water, and continuously add ammonia water during the whole titration process to control the pH to be always greater than 10 to ensure complete formation of the flocculent precipitate.

[0012] Further, in step S4, the preheat treatment temperature is 950 - 1200 °C.

[0013] Further, the preheat treatment time is 5 - 10 h.

[0014] Further, in step S4, sinter in the air atmosphere of the muffle furnace, and the calcination temperature is 1350 - 1600 °C.

[0015] Further, the calcination time is at least 6 h.

[0016] Further, the rare earth source includes but is not limited to rare earth oxides, rare earth chlorides, rare earth nitrates, and rare earth sulfates.

[0017] Further, the zirconium source includes but is not limited to zirconium oxychloride octahydrate, zirconium nitrate, zirconium sulfate, and zirconium chloride.

[0018] Further, in step S3, the generated flocculent precipitate is first centrifugally washed with deionized water repeatedly until neutral, and then washed once with ethanol and once with n-butanol respectively.

[0019] According to the calculation of atomic size difference, under the condition of satisfying the formation of a single-phase solid solution, a single-phase structure with stable structure at high temperature is prepared, ensuring that the material does not undergo a phase change during long-term high-temperature service. A new non-equiatomic doping system is provided, which significantly improves the mechanical properties of the Ce-containing rare earth zirconate thermal barrier coating material. The hardness and fracture toughness are significantly improved, while the elastic modulus and brittleness index are reduced. Moreover, the non-equiatomic doped material has good high-temperature phase stability, lower thermal conductivity and high thermal expansion coefficient. That is, under the condition of simultaneously satisfying low thermal conductivity and high thermal expansion performance, the Sc-doped Ce-containing rare earth zirconate thermal barrier coating material solves the mechanical property defects in the actual application process of the Ce-containing rare earth zirconate thermal barrier coating material, and significantly improves the mechanical properties such as hardness, elastic modulus, fracture toughness and brittleness of the Ce-containing rare earth zirconate thermal barrier coating material. The comprehensive performance of the rare earth zirconate is improved, the service life of the material is extended, and the practical application of the Ce-containing rare earth zirconate thermal barrier coating material in the field of thermal barrier coating materials is promoted. Description of the Drawings

[0020] Figure 1 is the X-ray diffraction pattern of (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 in Example 1 and the high-entropy rare earth zirconate (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 sintered at 1600 °C for 10 h;

[0021] Figure 2 is the X-ray diffraction pattern of (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 in Example 2 and the high-entropy rare earth zirconate (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 sintered at 1350 °C for 6 h;

[0022] Figure 3 is the X-ray diffraction pattern of (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2)2Zr2O7 and the high-entropy rare-earth zirconate of Comparative Example 3 (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 thermal expansion coefficient comparison diagram;

[0023] Figure 4 It is (Ce in Example 3 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 and the high-entropy rare-earth zirconate of Comparative Example 3 (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 mechanical property comparison diagram: hardness (HV), elastic modulus (E), fracture toughness (K IC ), brittleness index (Br);

[0024] Figure 5 It is the (Ce prepared in Example 3 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 (right figure) and the physical photo of the high-entropy rare-earth zirconate of Comparative Example 3 (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 (left figure). Detailed implementation manners

[0025] The following are specific embodiments of the present invention. In combination with the accompanying drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

[0026] Example 1

[0027] (1) According to the chemical composition formula: (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7. Dissolve rare-earth oxides Sc2O3, Dy2O3, Sm2O3, Gd2O3, Yb2O3 in dilute nitric acid to form a rare-earth nitrate solution; dissolve CeCl3 and ZrOCl2·8H2O in deionized water to form Zr4+ and Ce 3+ solution

[0028] (2) The mixed solution obtained in step (1) is added dropwise to ammonia water with pH > 10.0, and pH > 10 is maintained throughout the process while continuously stirring to form a flocculent precipitate;

[0029] (3) The precipitate obtained in step (2) is repeatedly centrifuged and washed with deionized water until pH ≈ 7 to remove chloride ions, and then dispersed, centrifuged, washed, and dried with ethanol and isopropanol;

[0030] (4) The dried mixed powder obtained in step (3) is preheated at 950 °C for 10 h in a high-temperature sintering furnace; the heat-treated powder is sintered at 1600 °C for 10 h in a high-temperature sintering furnace to obtain a pure-phase rare-earth zirconate thermal barrier coating material.

[0031] Example 2

[0032] (1) According to the chemical composition formula: (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7. Dissolve rare-earth oxides Sc2O3, Dy2O3, Sm2O3, Gd2O3, and Yb2O3 in dilute nitric acid to form a rare-earth nitrate solution; dissolve CeCl3 and ZrOCl2·8H2O in deionized water to form a Zr 4+ and Ce 3+ solution

[0033] (2) The mixed solution obtained in step (1) is added dropwise to ammonia water with pH > 10.0, and pH > 10 is maintained throughout the process while continuously stirring to form a flocculent precipitate;

[0034] (3) The precipitate obtained in step (2) is repeatedly centrifuged and washed with deionized water until pH ≈ 7 to remove chloride ions, and then dispersed, centrifuged, washed, and dried with ethanol and isopropanol;

[0035] (4) The dried mixed powder obtained in step (3) is preheated at 950 °C for 5 h in a high-temperature sintering furnace; continue to sinter at 1350 °C for 6 h in a high-temperature sintering furnace to obtain a pure-phase (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 powder

[0036] The powder is sintered in a spark plasma sintering furnace (SPS) for a period of time to obtain a dense rare earth zirconate thermal barrier coating bulk material, which is used to test the thermal and mechanical properties.

[0037] The pure-phase powder obtained in step (4) is loaded into a high-strength graphite mold and sintered in a spark plasma sintering furnace (SPS) at a pressure of 40 MPa and 1500 °C for 5 minutes. After decarburization and grinding, the thermal and mechanical properties are tested.

[0038] The thermal expansion coefficient of the rare earth zirconate thermal barrier coating material is 11.14×10 -6 K -1 (room temperature - 1500 °C), hardness (12.19 GPa), fracture toughness (1.33 MPa·m 1 / 2 ).

[0039] Example 3

[0040] (1) According to the chemical composition formula: (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7. The rare earth oxides Sc2O3, Dy2O3, Sm2O3, Gd2O3, and Yb2O3 are dissolved in dilute nitric acid to form a rare earth nitrate solution; CeCl3 and ZrOCl2·8H2O are dissolved in deionized water to form Zr 4+ and Ce 3+ solutions.

[0041] (2) The mixed solution obtained in step (1) is added dropwise to ammonia water with pH > 10.0, and the pH is maintained > 10 throughout the process, with continuous stirring, to generate a flocculent precipitate;

[0042] (3) The precipitate obtained in step (2) is repeatedly centrifuged and washed with deionized water until pH ≈ 7 to remove chloride ions, and then dispersed, centrifuged, washed, and dried with ethanol and isopropanol;

[0043] (4) The dried mixed powder obtained in step (3) is preheated in a high-temperature sintering furnace at 950 °C for 10 h; it is then sintered in the high-temperature sintering furnace at 1350 °C for 10 h to obtain a pure-phase (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 powder.

[0044] The powder was sintered in a spark plasma sintering furnace (SPS) for a period of time to obtain a dense rare earth zirconate thermal barrier coating bulk material, which was used to test the thermal and mechanical properties.

[0045] The pure phase powder obtained in step (4) was loaded into a high-strength graphite mold and sintered in a spark plasma sintering furnace (SPS) at a pressure of 40 MPa and 1500 °C for 5 min. After decarburization and grinding, the thermal and mechanical properties were tested.

[0046] The obtained thermal barrier coating material has a low thermal conductivity (0.95 W·m -1 K -1 , 1500 °C), a high coefficient of thermal expansion (11.65×10 -6 K -1 , room temperature - 1500 °C).

[0047] High hardness (17.41 GPa), a relatively low elastic modulus (252.42 GPa), a relatively high fracture toughness (1.84 MPa·m 1 / 2 ) and a low brittleness index (8.80 μm -1 / 2 ).

[0048] Comparative example 1:

[0049] (1) According to the chemical composition formula: (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7. The rare earth oxides Dy2O3, Sm2O3, Gd2O3, and Yb2O3 were dissolved in dilute nitric acid to form a rare earth nitrate solution; CeCl3 and ZrOCl2·8H2O were dissolved in deionized water to form a Zr 4 + and Ce 3+ solution.

[0050] (2) The mixed solution obtained in step (1) was added dropwise to ammonia water with pH > 10.0, and the pH was maintained > 10 throughout the process with continuous stirring to form a flocculent precipitate;

[0051] (3) The precipitate obtained in step (2) was repeatedly centrifuged and washed with deionized water until pH ≈ 7 to remove chloride ions, and then dispersed, centrifuged, washed, and dried with ethanol and isopropanol;

[0052] (4) The dried mixed powder obtained in step (3) was preheated at 950 °C for 10 h in a high-temperature sintering furnace; the heat-treated powder was sintered at 1600 °C for 10 h in a high-temperature sintering furnace to obtain a pure phase high-entropy rare earth zirconate thermal barrier coating material.

[0053] Comparative Example 2

[0054] (1) According to the chemical formula: (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7. Dissolve rare earth oxides Dy2O3, Sm2O3, Gd2O3, Yb2O3 in dilute nitric acid to form a rare earth nitrate solution; dissolve CeCl3 and ZrOCl2·8H2O in deionized water to form a Zr 4 + and Ce 3+ solution.

[0055] (2) Slowly add dropwise the mixed solution obtained in step (1) into ammonia water with pH>10.0, and keep pH>10 throughout the process, stirring continuously to generate a flocculent precipitate;

[0056] (3) Wash the precipitate obtained in step (2) repeatedly by centrifugation with deionized water until pH≈7 to remove chloride ions, and then disperse, centrifuge, wash and dry with ethanol and isopropanol;

[0057] (4) Preheat the dried mixed powder obtained in step (3) in a high-temperature sintering furnace at 950°C for 5 h; continue to sinter at 1350°C in the high-temperature sintering furnace for 6 h to obtain a pure-phase (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 powder.

[0058] Sinter the powder in a spark plasma sintering furnace SPS for a period of time to obtain a dense rare earth zirconate thermal barrier coating bulk material for testing thermal and mechanical properties.

[0059] Put the pure-phase powder obtained in step (4) into a high-strength graphite mold, in a spark plasma sintering furnace (SPS), sinter at 1500°C for 5 min under a pressure of 40 MPa, and perform thermal and mechanical property tests after decarburization and polishing.

[0060] The coefficient of thermal expansion is 11.09×10 -6 K -1 (room temperature - 1500°C), hardness (10.63 GPa), fracture toughness (1.07 MPa·m 1 / 2 )

[0061] Comparative Example 3

[0062] (1) According to the chemical formula: (Ce 0.2 Dy 0.2 Sm0.2 Gd 0.2 Yb 0.2 )2Zr2O7. The rare earth oxides Dy2O3, Sm2O3, Gd2O3, and Yb2O3 are dissolved in dilute nitric acid to form a rare earth nitrate solution; CeCl3 and ZrOCl2·8H2O are dissolved in deionized water to form a solution of Zr 4 + and Ce 3+ solution.

[0063] (2) The mixed solution obtained in step (1) is added dropwise to ammonia water with pH > 10.0, and the pH is maintained > 10 throughout the process, with continuous stirring to form a flocculent precipitate;

[0064] (3) The precipitate obtained in step (2) is repeatedly centrifuged and washed with deionized water until pH ≈ 7 to remove chloride ions, and then dispersed, centrifuged, washed, and dried with ethanol and isopropanol;

[0065] (4) The dried mixed powder obtained in step (3) is preheated at 950 °C for 10 h in a high-temperature sintering furnace; it is then sintered at 1350 °C for 10 h in the high-temperature sintering furnace to obtain a pure phase (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 powder.

[0066] The powder is sintered in a spark plasma sintering furnace (SPS) for a period of time to obtain a dense rare earth zirconate thermal barrier coating bulk material for testing thermal and mechanical properties.

[0067] The pure phase powder obtained in step (4) is loaded into a high-strength graphite mold, and in a spark plasma sintering furnace (SPS), at a pressure of 40 MPa, sintered at 1500 °C for 5 min, and after decarburization and grinding, thermal and mechanical property tests are carried out.

[0068] The obtained thermal barrier coating material has a low thermal conductivity (0.77 W·m -1 K -1 , 1500 °C), a high coefficient of thermal expansion (11.57×10 -6 K -1 ). A relatively low hardness (13.80 GPa), elastic modulus (267.23 GPa), poor fracture toughness (1.24 MPa·m 1 / 2 ) and a high brittleness index (11.52 μm -1 / 2 ).

[0069] Figure 1 is in Example 1 (Ce 0.1 Sc0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 and the high-entropy rare-earth zirconate of Comparative Example 1 (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 X-ray diffraction pattern sintered at 1600 °C for 10 h; From Figure 1 It can be seen that the thermal barrier coating materials prepared in Example 1 and Comparative Example 1 are both in phase.

[0070] Figure 2 It is (Ce in Example 2 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 and the high-entropy rare-earth zirconate of Comparative Example 2 (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 X-ray diffraction pattern sintered at 1350 °C for 6 h; From Figure 2 It can be seen that the thermal barrier coating materials prepared in Example 2 and Comparative Example 2 are both in phase.

[0071] Figure 3 In Example 3 (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 and the high-entropy rare-earth zirconate of Comparative Example 3 (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 coefficient of thermal expansion comparison chart;

[0072] Figure 4 In Example 3 (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 and the high-entropy rare-earth zirconate of Comparative Example 3 (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb0.2 ) Comparison chart of the mechanical properties of 2Zr2O7: hardness (HV), elastic modulus (E), fracture toughness (K IC ), and brittleness index (Br).

[0073] As Figure 3 and Figure 4 shown, in Comparative Example 3, due to the relatively large bond length of the Ce-O bond, the introduction of Ce elements can effectively increase the thermal expansion coefficient of the rare earth zirconate coating material, but its mechanical properties such as hardness and fracture toughness are relatively low. The non-equimolar doped (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 sample compared with the high-entropy (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7: The doping of element Sc ensures a low thermal conductivity while obtaining a slightly higher high thermal expansion coefficient than the high-entropy sample. And the non-equimolar doped (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 sample compared with the high-entropy (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 sample has a 26% increase in hardness, a 48% increase in fracture toughness, and a 31% decrease in the brittleness index of the material.

[0074] Figure 5 is the physical photograph of (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 (right figure) prepared by SPS sintering in Example 3 and the high-entropy rare earth zirconate (Ce 0.2 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 (left figure) in Comparative Example 3. As can be seen from Figure 5 it, the SPS sintered sample in Comparative Example 3 is extremely prone to cracking because the high-entropy rare earth zirconate ceramic material containing the variable-valence element Ce is reduced to Ce during the SPS high-temperature sintering process3+ , after annealing and decarburization, it is oxidized to Ce again 4+ . As the valence state of the element changes, the internal stress is large and the sample is severely cracked. The doped sample of this application is not easy to crack, avoiding this problem.

[0075] Where not otherwise involved, the prior art applies.

[0076] Although some specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the specific embodiments described or substitute them in a similar manner, but will not deviate from the direction of the present invention or exceed the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc. made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. A non-equidistant doping Ce-containing rare earth zirconate thermal barrier coating material, characterized in that, Its chemical composition formula is: (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7.

2. A preparation method of a non-equi-ratio doped Ce-containing rare earth zirconate thermal barrier coating material as described in claim 1, characterized in that, It includes the following steps: S1. Mix the rare earth source and zirconium source according to the molar ratio in the molecular formula of (Ce 0.1 Sc 0.1 Dy 0.2 Sm 0.2 Gd 0.2 Yb 0.2 )2Zr2O7 to prepare a mixed solution; S2. Using the reverse co-precipitation method, the solution obtained in step S1 is added dropwise to ammonia water while stirring continuously; S3. The flocculent precipitate obtained in step S2 is centrifuged, washed and dried; S4. The dried mixed powder obtained in step S3 is preheated for a period of time to obtain a mixed heat-treated powder, and the preheated mixed powder is sintered in a muffle furnace for a period of time to obtain a rare earth zirconate thermal barrier coating powder.

3. The preparation method according to claim 2, characterized in that: During the reverse co-precipitation titration in step S2, the solution is added dropwise to ammonia water, and ammonia water is continuously added during the whole titration process to control the pH to be always greater than 10 to ensure the complete formation of the flocculent precipitate.

4. The preparation method according to claim 2, characterized in that: In step S4, the preheating temperature is 950 - 1200 °C.

5. The preparation method according to claim 4, characterized in that: The preheating time is 5 - 10 h.

6. The preparation method according to claim 5, characterized in that: In step S4, it is sintered in the air atmosphere of the muffle furnace, and the calcination temperature is 1350 - 1600 °C.

7. The preparation method according to claim 6, characterized in that: The calcination time is at least 6 h.

8. The preparation method according to claim 2, characterized in that: The rare earth source includes rare earth oxides, rare earth chlorides, rare earth nitrates, and rare earth sulfates.

9. The preparation method according to claim 2, wherein: The zirconium source includes zirconium oxychloride octahydrate, zirconium nitrate, zirconium sulfate, and zirconium chloride.

10. The preparation method according to claim 2, characterized in that: In step S3, the generated flocculent precipitate is first centrifuged and washed repeatedly with deionized water until neutral, and then washed once with ethanol and n-butanol respectively.

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