Modified zirconate thermal barrier coating material resistant to corrosion of CMAS and molten salt as well as preparation method and application of modified zirconate thermal barrier coating material

Abstract

The invention discloses a modified zirconate thermal barrier coating material capable of resisting corrosion of CMAS and molten salt as well as a preparation method and application of the modified zirconate thermal barrier coating material. A high-temperature solid-phase reaction method is adopted, Sm2O3 powder, Yb2O3 powder, ZrO2 powder and Ce2O3 powder serve as raw materials and are subjected to ball milling and mixing according to the proportion, modified zirconate ceramic powder is synthesized, and then the compact zirconate thermal barrier coating material is obtained through dry pressing forming, high-temperature sintering and other methods. The obtained material is of a single-phase defect type fluorite crystal structure, and the fluorite structure has high fracture toughness. Meanwhile, the ytterbium ions can be quickly diffused to an interface to participate in a reaction due to the small radius, a high-melting-point apatite compact barrier layer is generated, the multi-element corrosion resistance of the ytterbium ions in a harsh turbine service environment can be improved, and the ytterbium ions can be used as a thermal barrier coating material on the surface of a hot end component of an aero-engine and have a good market prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparing thermal barrier coating materials for aero-engines, and particularly relates to a modified zirconate thermal barrier coating material resistant to CMAS + molten salt corrosion, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous development of aviation technology, the performance requirements of engines are continuously improved, and their thrust-to-weight ratio is getting higher and higher, resulting in a sharp rise in the turbine inlet temperature. However, the higher engine operating temperature makes the engine turbine blades and the TBCs materials on their surfaces face serious CMAS corrosion. The currently most widely used 6-8 wt.% Y2O3 partially stabilized ZrO2 (abbreviation: YSZ) material can no longer meet the requirements of the aviation industry for advanced TBCs. In addition to the coating cracking and failure caused by common sintering, phase change and other phenomena, the coating spalling failure caused by CMAS corrosion at temperatures above 1200 °C has attracted the attention of scholars. Therefore, scientific researchers are striving to seek new TBCs materials that can replace YSZ materials.

[0003] Among many new TBCs materials, rare earth zirconates not only have similar thermophysical properties to YSZ materials, but also have very good anti-CMAS corrosion performance, so they have been widely studied. However, compared with YSZ, the comprehensive mechanical properties of zirconates are poor. For example, the elastic modulus is higher and the fracture toughness is lower, which greatly limits their development and application.

[0004] The latest research shows that below the service temperature of the CMAS melting point, a thermal barrier coating failure similar to CMAS corrosion also occurs. This is because when some inferior fuels (usually containing impurities such as vanadium, sulfur, and sodium) are used in a turbine engine or when it is used in an offshore environment, the service air of the gas engine contains a large amount of salts. CMAS and molten salts (such as V2O5, NaVO3, Na2SO4, and NaCl, etc.) will have a coupling effect. The addition of salts reduces the CMAS melting point and weakens its crystallization ability, improves its flow permeability, so that it can penetrate into the coating at a lower temperature and react with it, accelerating the coating failure process. The multi-media corrosion of CMAS coupled with salts is more harmful to TBCs. Among them, CMAS + 10 wt% NaVO3 is the most harmful to TBCs and has become a representative in the study of CMAS coupled molten salt corrosion media.

[0005] Therefore, aiming at the problems of poor comprehensive mechanical properties and multi-element corrosion existing in the above zirconate materials, it is imperative to develop a modified zirconate thermal barrier coating material resistant to CMAS + molten salt corrosion. Summary of the Invention

[0006] The object of the present invention is to overcome the deficiencies existing in the prior art, and provide a modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion, its preparation method and application, so as to solve the problems of poor comprehensive mechanical properties of rare earth zirconate materials and poor multi-media corrosion resistance of traditional TBC materials.

[0007] To achieve the above technical object, the technical solution adopted in the embodiment of the present invention is as follows:

[0008] A modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion, its chemical formula is (Sm 1-x Yb x )2(Zr 0.7 Ce 0.3 )2O7, where n(Sm):n(Yb):n(Zr):n(Yb) = 1 - x:x:0.7:0.3, the value range of x is 0.1 - 0.3, the coating material is a defective fluorite structure, and the relative density reaches 91.85% - 95.13%, and the influence of porosity on thermophysical and mechanical properties can be ignored.

[0009] The preparation method of the above-mentioned modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion is prepared by a high-temperature solid-state reaction method using Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder as raw materials, and includes the following steps:

[0010] Step 1, using Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder as raw materials, weighing according to the specified molar ratio and pouring them into the ball mill tank in sequence, and dissolving and mixing the powders with absolute ethanol as the medium;

[0011] Step 2, ball milling in a planetary ball mill to make them fully mixed and uniform and refine the powder particle size to obtain a mixed slurry;

[0012] Step 3, drying the ball-milled mixed slurry and synthesizing zirconate powder by a high-temperature solid-state reaction method;

[0013] Step 4, grinding and sieving the synthesized ceramic powder, and using dry pressing molding method in combination with debinding and high-temperature sintering method to obtain a rare earth zirconate thermal barrier coating ceramic block material with the chemical formula (Sm 1-x Yb x )2(Zr 0.7 Ce 0.3 )2O7.

[0014] Further, the powder purity of the Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder in step 1 is ≥99.9%.

[0015] Further, in step 2, the rotation speed of ball milling is 400–500 rpm, and the ball milling time is 18–24 h.

[0016] Further, in step 3, the drying temperature of the mixed slurry is 400–600 °C, the time is 4–6 h, the high-temperature solid-phase reaction temperature is 1450–1550 °C, and the time is 4–8 h.

[0017] Further, in step 4, the powder after solid-phase reaction needs to be ground and sieved through 100–150 meshes. The first pressure for dry pressing is 150–190 MPa, the time is 55–65 s, the second pressure is 100–160 MPa, the time is 25–35 s, the debinding temperature is 500–550 °C, the time is 2–3 h, the sintering temperature is 1450–1500 °C, and the time is 15–20 h.

[0018] Application of the above-mentioned modified zirconate thermal barrier coating material with resistance to CMAS+ molten salt corrosion in preparing a thermal barrier coating on the surface of a hot-end component of an aeroengine.

[0019] Beneficial effects:

[0020] The present invention uses ytterbium- and cerium-doped samarium zirconate material to form a single-phase defective fluorite crystal structure, and the fluorite structure has high fracture toughness. At the same time, due to the relatively small ionic radius of ytterbium ions, they can diffuse to the interface faster to participate in the reaction, generating a dense high-melting-point apatite barrier layer, which can improve its resistance to multi-element corrosion in a harsh turbine service environment.

[0021] The rare-earth zirconate (Sm 1-x Yb x )2(Zr 0.7 Ce 0.3 )2O7 thermal barrier coating ceramic material obtained by the present invention through dry pressing and high-temperature sintering has a hardness of ≥9.85 GPa and a fracture toughness of ≥3.3126 MPa·m 1 / 2 , and its hardness and fracture toughness are higher than those of the undoped Sm2(Zr 0.7 Ce 0.3 )2O7 material (hardness is about 8.91 GPa, fracture toughness is about 3.003 MPa·m 1 / 2) have been significantly improved, which is beneficial to enhancing the anti-external impact ability of the thermal barrier coating. At the same time, the anti-CMAS + 10wt% NaVO3 multi-media corrosion performance of this material is better than that of Sm2Zr2O7 ceramic material, and it can generate a dense high-melting-point apatite barrier layer that effectively prevents the penetration of multi-media corrosion more quickly, and the thickness of the corrosion reaction layer is thinner, which will enhance the anti-multi-media corrosion ability of the thermal barrier coating in harsh service environments. At the same time, it has excellent anti-CMAS + 10wt% NaVO3 multi-media corrosion performance at 1300°C. This material has better comprehensive performance and has good promotion prospects in the field of heat insulation and protection of hot-end components such as gas turbines and aero-engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 XRD schematic diagrams of the (Sm 0.7 Yb 0.3 )2(Zr 0.7 Ce 0.3 )2O7 ceramic powders and sintered dense bulk materials prepared in Examples 1-3 and Comparative Example 1;

[0023] Figure 2 Schematic diagrams of the surface microtopographies of Examples 1-3 and Comparative Example 1: (A) Comparative Example 1; (B) Example 1; (C) Example 2; (D) Example 3;

[0024] Figure 3 Schematic diagrams of the comparison of hardness and fracture toughness of Examples 1-3 and Comparative Example 1;

[0025] Figure 4 Schematic diagrams of the comparison of surface morphologies of Examples 1-3 and Comparative Example 1 after being corroded by CMAS + 10wt% NaVO3 at 1300°C for 1, 5, and 10 h: (A) Comparative Example 1 corroded for 1 hour; (B) Example 1 corroded for 1 hour; (C) Example 2 corroded for 1 hour; (D) Example 3 corroded for 1 hour; (E) Comparative Example 1 corroded for 5 hours; (F) Example 1 corroded for 5 hours; (G) Example 2 corroded for 5 hours; (H) Example 3 corroded for 5 hours; (I) Comparative Example 1 corroded for 10 hours; (J) Example 1 corroded for 10 hours; (K) Example 2 corroded for 10 hours; (L) Example 3 corroded for 10 hours;

[0026] Figure 5Schematic diagram of cross-sectional morphology comparison between Examples 1-3 and Comparative Example 1 after being corroded by CMAS + 10wt% NaVO3 at 1300°C for 1, 5, and 10 hours: (A) Comparative Example 1 corroded for 1 hour; (B) Example 1 corroded for 1 hour; (C) Example 2 corroded for 1 hour; (D) Example 3 corroded for 1 hour; (E) Comparative Example 1 corroded for 5 hours; (F) Example 1 corroded for 5 hours; (G) Example 2 corroded for 5 hours; (H) Example 3 corroded for 5 hours; (I) Comparative Example 1 corroded for 10 hours; (J) Example 1 corroded for 10 hours; (K) Example 2 corroded for 10 hours; (L) Example 3 corroded for 10 hours. Detailed implementation manners

[0027] To more clearly elaborate the purpose, technical solution, and advantages of the present invention, the following further details the present invention in conjunction with the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] A modified zirconate thermal barrier coating material resistant to CMAS + molten salt corrosion, whose chemical formula is (Sm 1-x Yb x )2(Zr 0.7 Ce 0.3 )2O7, where n(Sm):n(Yb):n(Zr):n(Yb) = 1 - x:x:0.7:0.3, the value range of x is 0.1 - 0.3, the coating materials are all defective fluorite structures, and the relative density reaches 91.85% - 95.13%, and the influence of porosity on thermophysical and mechanical properties can be ignored.

[0029] The preparation method of the above-mentioned modified zirconate thermal barrier coating material resistant to CMAS + molten salt corrosion is prepared by a high-temperature solid-state reaction method using Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder as raw materials, and includes the following steps:

[0030] Step 1, using Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder as raw materials, weighing according to the specified molar ratio and pouring them into the ball mill tank in sequence, and dissolving and mixing the powders with absolute ethanol as the medium;

[0031] Step 2, ball milling in a planetary ball mill to make them fully mixed and refined powder particle size to obtain a mixed slurry;

[0032] Step 3, drying the ball-milled mixed slurry and synthesizing zirconate powder by a high-temperature solid-state reaction method;

[0033] Step 4, grinding and sieving the synthesized ceramic powder, and using dry pressing molding method in combination with debinding and high-temperature sintering method to obtain a chemical formula of (Sm1-x Yb x )2(Zr 0.7 Ce 0.3 rare earth zirconate thermal barrier coating ceramic bulk material of (Sm

[0034] Further, the powder purities of the Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder described in step 1 are all ≥ 99.9%.

[0035] Further, the rotation speed of ball milling in step 2 is 400–500 rpm, and the ball milling time is 18–24 h.

[0036] Further, the drying temperature of the mixed slurry in step 3 is 400–600 °C, the time is 4-6 h, the high-temperature solid-phase reaction temperature is 1450-1550 °C, and the time is 4–8 h.

[0037] Further, the powder after solid-phase reaction in step 4 needs to be ground and then screened through a 100-150 mesh sieve. The first pressing for dry pressing forming is 150-190 MPa, the time is 55-65 s, the second pressing is 100-160 MPa, the time is 25-35 s, the debinding temperature is 500-550 °C, the time is 2-3 h, the sintering temperature is 1450-1500 °C, and the time is 15-20 h.

[0038] Example 1

[0039] A preparation method of a modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion, comprising the following steps:

[0040] (1) First, calculate the amounts of each oxide required to prepare the ceramic according to the molar ratio of the elements, weigh the corresponding amounts of Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder, and pour the four powders into the ball milling tank in turn with anhydrous ethanol as the medium to fully mix the powders. Among them, the purities of the Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder are all ≥ 99.9%;

[0041] (2) Place the ball milling tank in a planetary ball mill and ball mill at a speed of 400 rpm for 18 h to obtain a uniform mixed solution;

[0042] (3) Place the obtained mixed solution in a muffle furnace for drying at 600 °C for 6 h, and then carry out a high-temperature solid-phase reaction at 1500 °C for 5 h to obtain (Sm 0.9 Yb 0.1 )2(Zr 0.7 Ce 0.3 )2O7 rare earth zirconate ceramic powder;

[0043] (4) The obtained rare earth ceramic powder is successively subjected to treatments such as grinding, passing through a 100-mesh sieve, granulating with PVA, and dry pressing (one-time pressing at 163 MPa for 60 s, and secondary pressing at 102 MPa for 30 s). Then, it is degummed in a muffle furnace (the degumming temperature is 550 °C and the duration is 2.5 h), and sintered at 1500 °C for 18 h to obtain the required (Sm 0.9 Yb 0.1 )2(Zr 0.7 Ce 0.3 )2O7 rare earth ceramic block; the molar ratio of Sm2O3, Yb2O3, ZrO2, and Ce2O3 is 0.9:0.1:0.7:0.3; among them, the concentration of PVA is 5%, and PVA is weighed according to 8% of the mass of the ceramic powder and mixed with the ceramic powder to enhance the plasticity of the ceramic powder and achieve the granulation effect.

[0044] CMAS + 10 wt% NaVO3 multi-element corrosion test: The surface of the prepared (Sm 0.9 Yb 0.1 )2(Zr 0.7 Ce 0.3 )2O7 sintered ceramic block is polished, and the CMAS + 10 wt% NaVO3 powder is uniformly coated on the sample surface at a density of 30 mg / cm 2 . Subsequently, it is placed in a muffle furnace and heated to 1300 °C at a heating / cooling rate of 5 °C / min and held for 1, 5, and 10 h in batches, and the corrosion situation of the specimen is observed by SEM and EDS.

[0045] Example 2

[0046] A preparation method of a modified zirconate thermal barrier coating material resistant to CMAS + molten salt corrosion, comprising the following steps:

[0047] (1) First, calculate the amounts of each oxide required for the ceramic to be prepared according to the molar ratio of the elements, weigh the corresponding amounts of Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder, and pour the four powders into the ball milling tank in turn with absolute ethanol as the medium to fully mix the powders. Among them, the purities of Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder are all ≥ 99.9%;

[0048] (2) Place the ball milling tank in a planetary ball mill and ball mill at a speed of 400 rpm for 18 h to obtain a uniform mixed solution;

[0049] (3) Put the obtained mixed solution into a muffle furnace and dry it at 600 °C for 6 h and carry out a high-temperature solid-phase reaction at 1500 °C for 5 h to obtain (Sm 0.8 Yb 0.2 )2(Zr0.7 Ce 0.3 )2O7 rare earth zirconate ceramic powder;

[0050] (4) After the obtained rare earth ceramic powder is successively subjected to grinding, passing through a 100-mesh sieve, PVA granulation, and dry pressing (one-time pressing, 163 MPa, time 60 s, secondary pressing 102 MPa, time 30 s), etc., it is then degummed in a muffle furnace (temperature 550 °C, time 2.5 h), sintered at 1500 °C for 18 h to obtain the required (Sm 0.8 Yb 0.2 )2(Zr 0.7 Ce 0.3 )2O7 rare earth ceramic bulk; The molar ratio of Sm2O3, Yb2O3, ZrO2 and Ce2O3 is 0.8:0.2:0.7:0.3. Among them, the concentration of PVA is 5%, and PVA is weighed according to 8% of the mass of the ceramic powder and mixed with the ceramic powder. The purpose is to enhance the plasticity of the ceramic powder and achieve the granulation effect.

[0051] CMAS + 10 wt% NaVO3 multi-component corrosion test: The prepared (Sm 0.8 Yb 0.2 )2(Zr 0.7 Ce 0.3 )2O7 sintered ceramic block is polished on the surface, and the CMAS + 10 wt% NaVO3 powder is uniformly coated on the sample surface at a density of 30 mg / cm 2 . Subsequently, it is placed in a muffle furnace and heated to 1300 °C at a heating / cooling rate of 5 °C / min and held for 1, 5, and 10 h in batches, and the corrosion condition of the specimen is observed by SEM and EDS.

[0052] Example 3

[0053] A preparation method of a modified zirconate thermal barrier coating material resistant to CMAS + molten salt corrosion, comprising the following steps:

[0054] (1) First, calculate the dosage of each oxide in the ceramic to be prepared according to the molar ratio of the elements, weigh the corresponding amounts of Sm2O3 powder, Yb2O3 powder, ZrO2 powder and Ce2O3 powder, and pour the four powders into the ball milling tank in turn with anhydrous ethanol as the medium to make the powders fully mixed. Among them, the purities of Sm2O3 powder, Yb2O3 powder, ZrO2 powder and Ce2O3 powder are all ≥ 99.9%;

[0055] (2) Place the ball milling tank in a planetary ball mill and ball mill at 400 rpm for 18 h to obtain a uniform mixed solution;

[0056] (3) The obtained mixed solution is placed in a muffle furnace for drying at 600 °C for 6 h and high-temperature solid-phase reaction at 1500 °C for 5 h to obtain (Sm 0.7 Yb 0.3 )2(Zr 0.7 Ce 0.3 )2O7 rare earth zirconate ceramic powder;

[0057] (4) The obtained rare earth ceramic powder is successively ground, passed through a 100-mesh sieve, granulated with PVA, and dry-pressed (one-time pressure of 163 MPa, time of 60 s, two-time pressure of 102 MPa, time of 30 s), etc. After treatment, it is then degummed by a muffle furnace (temperature 550 °C, time 2.5 h), sintered at 1500 °C for 18 h to obtain the required (Sm 0.7 Yb 0.3 )2(Zr 0.7 Ce 0.3 )2O7 rare earth ceramic bulk; The molar ratio of Sm2O3, Yb2O3, ZrO2 and Ce2O3 is 0.7:0.3:0.7:0.3. Among them, the concentration of PVA is 5%, and PVA is weighed according to 8% of the mass of the ceramic powder and mixed with the ceramic powder to enhance the plasticity of the ceramic powder and achieve the granulation effect.

[0058] CMAS + 10 wt% NaVO3 multi-element corrosion test: The surface of the prepared (Sm 0.7 Yb 0.3 )2(Zr 0.7 Ce 0.3 )2O7 sintered ceramic block is polished, and the CMAS + 10 wt% NaVO3 powder is uniformly coated on the sample surface at a density of 30 mg / cm 2 . Subsequently, it is placed in a muffle furnace and heated to 1300 °C at a heating / cooling rate of 5 °C / min for batchwise insulation for 1, 5 and 10 h, and the corrosion situation of the specimen is observed by SEM and EDS.

[0059] Comparative Example 1

[0060] A preparation method of a modified zirconate thermal barrier coating material resistant to CMAS + molten salt corrosion includes the following steps:

[0061] (1) First, calculate the amounts of each oxide required to prepare the ceramic according to the molar ratio of the elements, weigh the corresponding amounts of Sm2O3 powder, ZrO2 powder and Ce2O3 powder, and pour the four powders into the ball mill tank in turn with anhydrous ethanol as the medium to fully mix the powders. Among them, the purities of Sm2O3 powder, ZrO2 powder and Ce2O3 powder are all ≥ 99.9%;

[0062] (2) Put the ball milling pot into a planetary ball mill and ball mill at 400 rpm for 18 h to obtain a uniform mixed solution;

[0063] (3) Put the obtained mixed solution into a muffle furnace and dry it at 600 °C for 6 h and carry out high-temperature solid-state reaction at 1500 °C for 5 h to obtain Sm2(Zr 0.7 Ce 0.3 )2O7 rare earth zirconate ceramic powder;

[0064] (4) After the obtained rare earth ceramic powder is successively ground, passed through a 100-mesh sieve, granulated with PVA, and dry-pressed (one-time pressing, 163 MPa, time 60 s, secondary pressing 102 MPa, time 30 s), etc., then carry out debinding through a muffle furnace (temperature 550 °C, time 2.5 h), sinter at 1500 °C for 18 h to obtain the required Sm2(Zr 0.7 Ce 0.3 )2O7 rare earth ceramic bulk; The molar ratio of Sm2O3, ZrO2 and Ce2O3 is 1:0.7:0.3. Among them, the concentration of PVA is 5%, and PVA is weighed according to 8% of the mass of the ceramic powder and mixed with the ceramic powder. The purpose is to enhance the plasticity of the ceramic powder and achieve the granulation effect.

[0065] CMAS + 10 wt% NaVO3 multi-element corrosion test: Polish the surface of the prepared Sm2(Zr 0.7 Ce 0.3 )2O7 sintered ceramic block, and uniformly coat the CMAS + 10 wt% NaVO3 powder on the sample surface at a density of 30 mg / cm 2 . Then put it into a muffle furnace and heat it to 1300 °C at a heating / cooling rate of 5 °C / min and hold for 1, 5 and 10 h in batches, and observe the corrosion situation of the specimen by SEM and EDS.

[0066] Performance test

[0067] As can be seen from [[ID=, Figure 1 the rare earth zirconate ceramic material synthesized by the solid-state reaction method has characteristic peaks (222), (400), (440), (622), (444) of the defective fluorite structure. Combining Figure 2 it can be known that the rare earth zirconate ceramic of the present invention is a defective fluorite phase, and the surface of this ceramic is dense and has a low porosity, as Figure 2 shown.

[0068] As can be seen from Figure 3 the fracture toughness and hardness of Examples 1-3 are 3.3126 MPa×m 1 / 2 and 9.85 GPa, 3.2321 MPa×m 1 / 2and 9.16 GPa, 3.2005 MPa×m 1 / 2 and 9.76 GPa, both are higher than 3.0003 MPa×m of fracture toughness and hardness in Comparative Example 1 1 / 2 and 8.91 GPa, indicating that doping is beneficial to enhancing the strain tolerance and anti-particle erosion ability of the coating material.

[0069] From Figure 4 the corrosion surface morphology, it can be seen that when the (Sm 1-x Yb x )2(Zr 0.7 Ce 0.3 )2O7 ceramics and the Sm2(Zr 0.7 Ce 0.3 )2O7 ceramic material of Comparative Example 1 react with CMAS + 10 wt% NaVO3 at 1300 °C for 1 h, there are residual corrosion media on the surface, indicating that all four materials have a certain anti-corrosion performance in the early stage of multi-element corrosion. At the same time, it can be observed that the size of the corrosion products in Comparative Example 1 is relatively large, while the size of the corrosion products on the corrosion surfaces of Examples 1-3 becomes smaller and the number increases with the increase of the doping content. After 5 h of corrosion, there are still residual corrosion media on the surfaces of the four samples, but the residual amount is significantly less than that of the 1 h sample corrosion surface. Among them, the corrosion surface of Comparative Example 1 has the least residue and is about to expose the morphology of the internal inter-reaction layer, indicating that all four materials still have a certain anti-corrosion performance in the middle and early stages of multi-element corrosion. It can also be observed that the size of the corrosion products in Comparative Example 1 is relatively large and the number is small, while in Examples 1-3, with the increase of the doping content, the number of corrosion products increases and the size becomes smaller. After 10 h of corrosion with CMAS + 10 wt% NaVO3, the internal reaction layer morphology is exposed for all four ceramics. Through comparative analysis, it can be seen that with the increase of the Yb doping content, the proportion of rod-shaped apatite increases and the size becomes smaller, and the proportion of spherical fluorite structure decreases and the size also becomes smaller. This is because the rare earth element Yb with a smaller ionic radius diffuses to the reaction interface faster than Sm with a plasma radius, and the formation enthalpy of Yb-apatite is lower, so a large amount of apatite can be generated faster. In the middle and late stages of corrosion, the more the number of rod-shaped apatite generated and the smaller the size, the denser barrier layer can be formed by interlacing with spherical fluorite, slowing down the further rapid penetration of the corrosion medium. When the penetration rate of the corrosion medium is less than the generation rate of the corrosion products, the harm caused by multi-element corrosion can be reduced and the anti-corrosion performance of the thermal barrier coating can be improved. Compared with Comparative Example 1 and Example 1, the rod-shaped and spherical products on the corrosion surfaces of Examples 2 and 3 are small and dense, which also shows that (Sm 0.8 Yb 0.2 )2(Zr 0.7 Ce 0.3 )2O7 and (Sm 0.7 Yb 0.3 )2(Zr0.7 Ce 0.3 The Ce2O7 ceramic has good corrosion resistance in a multi - corrosion environment.

[0070] From Figure 5 the corrosion cross - section morphology, it can be seen that the corrosion morphologies of the four thermal barrier coating materials and CMAS + 10wt% NaVO3 can be divided into three parts: the top - layer CMAS + 10wt% NaVO3 residual layer, the middle reaction layer, and the bottom uncorroded ceramic layer. Among them, the middle reaction layer can be further divided into an upper loose reaction layer and a lower dense reaction layer. The resistance of the ceramic material to the multi - corrosion of CMAS + 10wt% NaVO3 is reflected in the depth and change of the corrosion reaction layer. Through comparative analysis, it can be found that at the same corrosion time, the thickness of the reaction layer decreases with the increase of the Yb content. As time prolongs, the thickness of the reaction layer gradually increases, and the growth rate of the reaction layer thickness in Example 2 and Example 3 gradually slows down, indicating that the (Sm 0.7 Yb 0.3 )2(Zr 0.7 Ce 0.3 )2O7 ceramic material has good multi - corrosion resistance.

[0071] In summary, compared with Sm2(Zr 0.7 Ce 0.3 )2O7, the rare - earth zirconate of the present invention has higher fracture toughness and hardness, as well as more excellent multi - corrosion resistance, and can meet the material selection requirements for thermal barrier coating materials to serve in harsh service environments.

[0072] Finally, it should be noted that the above - mentioned specific embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion, characterized in that, The chemical formula of the modified zirconate thermal barrier coating material is (Sm 1-x Yb x )2(Zr 0.7 Ce 0.3 )2O7, where n(Sm):n(Yb):n(Zr):n(Yb) = 1 - x:x:0.7:0.3, the value range of x is 0.1 to 0.

3. The coating materials are all defective fluorite structures, and the relative density reaches 91.85% - 95.13%. The influence of porosity on the thermophysical and mechanical properties can be ignored.

2. The preparation method of the modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion according to claim 1, characterized in that It is prepared from Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder by the high-temperature solid-state reaction method, and includes the following steps: Step 1: Weigh Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder as raw materials according to the specified molar ratio and pour them into the ball mill tank in sequence, and dissolve the mixed powder with anhydrous ethanol as the medium; Step 2: Ball mill in a planetary ball mill to make them fully mixed and refined, and obtain a mixed slurry; Step 3: Dry the mixed slurry after ball milling and synthesize zirconate powder by the high-temperature solid-state reaction method; Step 4, grind and screen the synthesized ceramic powder, and use the dry pressing forming method in combination with debinding and high-temperature sintering to obtain a rare earth zirconate thermal barrier coating ceramic bulk material with the chemical formula (Sm 1-x Yb x )2(Zr 0.7 Ce 0.3 )2O7.

3. The preparation method of the modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion according to claim 1, characterized in that, The powder purity of the Sm2O3 powder, Yb2O3 powder, ZrO2 powder, and Ce2O3 powder described in Step 1 is ≥99.9%; 4. The preparation method of the modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion according to claim 1, characterized in that, The rotation speed of ball milling in Step 2 is 400–500 rpm, and the ball milling time is 18–24 h; 5. The preparation method of the modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion according to claim 1, characterized in that, In Step 3, the drying temperature of the mixed slurry is 400–600 °C, the time is 4–6 h, the high-temperature solid-state reaction temperature is 1450–1550 °C, and the time is 4–8 h; 6. The preparation method of the modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion according to claim 1, characterized in that, In Step 4, the powder after solid-state reaction needs to be ground and screened through 100-150 mesh. The first pressure of dry pressing is 150-190 MPa, the time is 55-65 s, the second pressure is 100-160 MPa, the time is 25-35 s, the debinding temperature is 500-550 °C, the time is 2-3 h, the sintering temperature is 1450-1500 °C, and the time is 15-20 h; 7. Application of the modified zirconate thermal barrier coating material resistant to CMAS+ molten salt corrosion prepared by the preparation method according to any one of claims 2-6 in preparing the thermal barrier coating on the surface of the hot-end components of an aero-engine.

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