Multicomponent rare earth zirconia material resistant to molten sand dust erosion and method for producing the same

Abstract

The application discloses a kind of multi-element rare earth zirconia materials resistant to molten sand dust erosion and a preparation method thereof, and belongs to the technical field of thermal barrier coating materials of aero-engine.The material is ZrO 2、 The main rare earth oxide Y2O3, the auxiliary rare earth oxide A2O3 and B2O3 are used as base raw materials, precisely proportioned, ball-milled and mixed, and a multi-element rare earth zirconia material is synthesized by a high-temperature solid-phase reaction method.The material exhibits the structural characteristics of a defect fluorite phase, is prepared into a dense ceramic block by dry pressing and high-temperature sintering, and has excellent performance, low thermal conductivity and high-temperature stability after its resistance to molten sand dust corrosion is investigated.The material of the application is suitable for application to thermal barrier coating materials of hot-end components of an aero-engine, significantly improves the resistance to high-temperature molten sand dust corrosion and service life of the components.The application solves the technical problems of high thermal conductivity, insufficient resistance to molten sand dust erosion and poor thermal stability of thermal barrier coating materials.

Description

Technical Field

[0001] This invention belongs to the technical field of thermal barrier coating materials for aero-engines, specifically relating to a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion and its preparation method. Background Technology

[0002] High-temperature alloy components operating under the high temperature and pressure of aero-engines and the harsh turbine environment require thermal barrier coatings (TBCs) with low thermal conductivity, high thermal insulation, and good fracture toughness to improve strain tolerance under complex stress conditions. With increasing demands for high efficiency in aero-engines, higher surface temperatures present new challenges for TBCs. During service, TBCs must withstand not only high temperatures and pressures but also the erosion of environmental contaminants (CMAS) such as dust and sand. CMAS deposits melt, penetrate, and react with the thermal barrier coating (TBC), reducing its thermomechanical properties and leading to premature failure. The composition of sand and dust from the environment is particularly complex; molten sand and dust can cause more severe erosion and damage to the TBC, necessitating excellent resistance to molten sand and dust erosion in the TBC.

[0003] Traditional YSZ (yttrium-stabilized zirconium oxide) materials can chemically react with molten CMAS adhering to their surface, leading to coating phase instability and structural damage. Studies have shown that rare-earth zirconate materials (such as gadolinium zirconate) are considered a potential choice for thermal barrier coatings due to their lower thermal conductivity and good CMAS resistance. However, these materials exhibit limitations in corrosion resistance (especially resistance to molten sand and dust erosion) at service temperatures above 1300°C. The rare-earth elements in these materials cannot quickly form a continuous, dense barrier layer with CMAS to resist high-temperature molten sand and dust corrosion, thus failing to provide reliable long-life protection for thermal barrier coatings. With the deepening research and technological maturity of multi-component ceramic systems, ceramic materials developed through multi-component design often exhibit comprehensive properties surpassing those of single-component zirconium oxide or zirconate materials, particularly in mechanical, thermal, and corrosion resistance, thus showing great application potential in the field of high-temperature structural materials for aerospace.

[0004] In view of the shortcomings of existing technologies, a high-performance thermal barrier coating material integrating excellent mechanical, thermal, and molten sand and dust erosion properties is being developed through multi-element rare earth synergistic design. The development of this novel thermal barrier coating material is expected to improve the performance and durability of aero-engine components, thereby promoting the development of aerospace technology to a higher level. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a multi-element rare earth zirconium oxide material and its preparation method that resists molten sand and dust erosion, so as to solve the technical problems of high thermal conductivity, insufficient resistance to molten sand and dust erosion and poor thermal stability of thermal barrier coating materials.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention provides a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion. The chemical composition of the multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion is: (xY2O3-yA2O3-yB2O3)-(1-x-2y)ZrO2, wherein the molar percentage of x is: 17%≤x≤31%, the molar percentage of y is: 1.5%<y<8.5%, and 34%≤(x+2y)≤46%.

[0008] The multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion includes zirconium oxide, primary rare earth oxide Y2O3, secondary rare earth oxide A2O3, and secondary rare earth oxide B2O3. Among them, the rare earth elements A or B in secondary rare earth oxides A2O3 and B2O3 include any one of Gd, Dy, Yb, and Er. The primary rare earth oxide Y2O3 and the two secondary rare earth oxides are in a non-equimolar ratio, while the secondary rare earth oxides are in an equimolar ratio.

[0009] As an improvement, the particle size of the multi-element rare earth zirconium oxide material is less than 0.15 mm.

[0010] This invention also provides a method for preparing the above-mentioned multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion, specifically including the following steps:

[0011] 1) Based on the predetermined molar ratio of oxide components, accurately calculate the amount of each raw material required for Y2O3, A2O3, B2O3 and ZrO2 powders, weigh out Y2O3, A2O3, B2O3 and ZrO2 powders respectively, and ball mill them to obtain a mixed slurry;

[0012] 2) The above mixed slurry is dried to remove excess ethanol, and then the powder is sieved to ensure uniform particle size. The treated powder is then subjected to a solid-phase reaction at high temperature to synthesize a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion.

[0013] As an improvement, in step 1), the Y2O3, A2O3, B2O3 and ZrO2 powders are nano-sized powders with a particle size ≤50nm and a purity ≥99.9%.

[0014] As an improvement, in step 1), the ball milling conditions are as follows: the powder is added to the ball milling jar in sequence, and an appropriate amount of grinding beads and solvent are added as a mixing medium, wherein the mass ratio of grinding beads, powder and solvent is 3:1:2 ~ 6:1:3, the rotation speed is 130~160 rpm, and the time is 12~24 h.

[0015] The main function of ball milling is to uniformly mix powder materials and reduce agglomeration through mechanical force. During ball milling, the number of grinding balls, the proportion of materials, the amount of solvent, and the settings of ball milling speed and time all directly affect the uniformity and dispersibility of the powder.

[0016] As an improvement, in step 2), after drying at a temperature of 80~100℃, the material is sieved through a 40-mesh sieve.

[0017] As an improvement, in step 2), the high-temperature solid-phase reaction is first heated to 800~1000 ℃ and held for 1~4 h, then heated to 1200~1400 ℃ and held for 1~4 h, and finally cooled with the furnace.

[0018] As an improvement, the multi-element rare earth zirconium oxide material in step 2) above is further ground and sieved, and then formed by dry pressing. The formed block is sintered at high temperature to obtain dense multi-element rare earth zirconium oxide ceramic block material.

[0019] As an improvement, the above sieve mesh size is 150 mesh, and the multi-element powder material is dry-pressed into shape using a manual hydraulic press with a uniaxial pressure of 200MPa for 30~60 s. The diameter of the green blank is 10-25.4 mm and the thickness is not less than 1 mm.

[0020] Dry pressing with a uniaxial pressure of 200 MPa helps the powder to achieve uniform densification during the forming process, reducing the formation of pores and cracks. This pressure value ensures the mechanical strength of the green body, and the powder can maintain good morphological stability during sintering.

[0021] As an improvement, the sintering temperature is 1500~1600 ℃ and the time is not less than 20 h.

[0022] As an improvement, the mesh size of the sieve is 100-200 mesh.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention provides a multi-component rare earth zirconium oxide material resistant to molten sand and dust erosion. It employs a multi-component rare earth zirconium oxide design, with Y₂O₃ as the main rare earth oxide and A₂O₃ and B₂O₃ as auxiliary rare earth oxides. The main rare earth oxide and auxiliary rare earth oxides are in a non-equimolar ratio, while the auxiliary rare earth oxides are in an equimolar ratio. This specific ratio makes the chemical composition of the material more stable and helps to improve the material's resistance to molten sand and dust erosion by utilizing the synergistic effect of the main and auxiliary rare earths. The chemical formula of the multi-element rare earth zirconium oxide material is (xY₂O₃-yA₂O₃-yB₂O₃)-(1-x-2y)ZrO₂. The main rare earth oxide, Y₂O₃, imparts stability to the crystal structure, enhancing the material's structural stability and resistance to molten sand and dust erosion. The addition of auxiliary rare earth oxides can regulate the material's lattice structure and physical properties. Through the combined effect of different ionic radii and lattice distortions, the scattering effect of the lattice can be increased, thereby reducing the material's thermal conductivity and improving the coating's thermal insulation performance. This invention utilizes the synergistic design of multiple rare earth elements. The synergistic effect of multiple rare earth elements can overcome the performance deficiencies of single rare earth materials in high-temperature environments, providing superior overall performance. By optimizing the composition ratio of the main and auxiliary rare earth elements and combining the advantages of multiple rare earth elements, a novel multi-element rare earth zirconium oxide thermal barrier coating material has been developed, improving the thermal barrier coating's resistance to molten sand and dust erosion, low thermal conductivity, and thermal stability. This invention solves the technical problems of high thermal conductivity, insufficient resistance to molten sand and dust erosion, and poor thermal stability in thermal barrier coating materials.

[0025] This invention also provides a method for preparing a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion. The ternary rare earth zirconium oxide material is synthesized from Y2O3, A2O3, B2O3 and ZrO2 through a high-temperature solid-state reaction method, and then the dense ceramic block of multi-element rare earth zirconium oxide resistant to molten sand and dust erosion is obtained by dry pressing and high-temperature sintering. First, controlling the molar percentage of the main rare earth oxides to 17 ≤ x ≤ 31% ensures the structural stability of the rare earth zirconia thermal barrier coating material under high-temperature corrosion conditions. The total molar percentage of the auxiliary rare earth oxides is controlled to 3 < 2y < 17%. The addition of auxiliary rare earth oxides can adjust the lattice structure and physical properties of the material. Through the combined effect of different ionic radii and lattice distortions, the lattice scattering effect can be increased, thereby reducing the thermal conductivity of the material and improving the thermal insulation performance of the coating. Ensuring the molar percentage of (x + 2y) is between 34-46% balances the effects of the main and auxiliary rare earth oxides, enhancing the overall performance of the material, including low thermal conductivity, high-temperature phase stability, and resistance to molten sand and dust erosion. It also helps to form a more stable oxide phase, reducing the erosion and penetration of molten CMAS into the coating material and improving resistance to molten sand and dust. Second, a solid-state reaction is carried out at high temperature to synthesize the multi-element rare earth zirconia material from the powder. This step is crucial for material formation; high temperature promotes the chemical reaction between oxides, forming the desired multi-element rare earth zirconia material.

[0026] Furthermore, the original powder of the multi-element rare earth zirconium oxide material has a particle size ≤50nm and a purity ≥99.9%. The use of nanoscale powder (≤50nm) can significantly improve the material's reactivity and sintering density. On the one hand, the smaller particle size provides a larger specific surface area, promoting uniform dispersion and reaction among the components. This helps to obtain a more uniform microstructure and avoids performance defects caused by the uneven distribution of large particles; powder with a purity ≥99.9% can reduce the introduction of impurities, preventing impurities from causing a decline in material performance at high temperatures. On the other hand, due to the high surface energy and reactivity of nanoparticles, high-temperature solid-state reactions using nanomaterials can usually be completed at lower temperatures. This not only saves energy but also reduces equipment requirements and production costs. At the nanoscale, the material's microstructure and component distribution are more uniform. Using nanomaterials makes it easier to control the material's composition and uniformity, avoiding the component segregation problem caused by large particles in traditional preparation methods. At the same time, nanoparticles can form a dense microstructure through diffusion or sintering at high temperatures, which can significantly improve the material's durability and corrosion resistance. Experiments show that the multi-element rare-earth zirconium oxide material exhibits a lower molten sand corrosion depth than NASA's ZrO2-9.5Y2O3-2.25Gd2O3-2.25Yb2O3 multi-element ceramic material and gadolinium zirconate material, making it more suitable for operation in environments with ambient sand and dust. Furthermore, after molten sand and dust corrosion at 1400 °C, the multi-element rare-earth zirconium oxide material of this invention forms a dense ternary rare-earth silicate barrier layer (Y-Yb-Gd)Si2O7 and a calcium-rich apatite network layer (the product of the reaction and crystallization of multi-element rare-earth zirconium oxide and molten sand and dust), effectively hindering the penetration of molten sand and dust, inhibiting grain boundary corrosion, and possessing excellent resistance to molten sand and dust erosion. This is expected to improve the resistance to environmental sand and dust corrosion in the harsh turbine service environment in the field of thermal barrier coatings.

[0027] Furthermore, the mass ratio of milling beads, powder, and solvent is controlled at 3:1:2 to 6:1:3, the rotation speed is 130 to 160 rpm, and the time is 12 to 24 hours. These parameters ensure that the powder is fully mixed and avoid excessive milling that could lead to overly fine particle size or powder agglomeration. By precisely controlling the milling parameters, the composition distribution of the material is more uniform, which is conducive to subsequent sintering densification and uniform phase formation, thereby improving the overall performance of the material.

[0028] Furthermore, the high-temperature solid-state reaction promotes the full reaction of the various oxide powders at high temperatures to generate the target multi-element rare-earth zirconium oxide material. Heating to 800-1000℃ and holding for 1-4 hours helps remove surface adsorbates and residual stress from the powder. The subsequent heating to 1200-1400℃ and holding for 1-4 hours, the main reaction temperature stage, ensures the full reaction of all components. Furnace cooling avoids microcracks caused by thermal stress from excessively rapid cooling. Segmented heating and holding ensures the full reaction of all components and the densification of the material. Furnace cooling avoids thermal stress concentration during cooling, enhancing the material's mechanical strength and thermal stability.

[0029] Furthermore, the multi-element rare earth zirconium oxide material is sintered at high temperature to obtain a dense multi-element rare earth zirconium oxide ceramic block. The high-temperature sintering ensures the stability and corrosion resistance of the material.

[0030] Furthermore, the sintering temperature was set to 1500℃ and maintained for at least 20 hours to ensure sufficient sintering and appropriate grain growth, thus guaranteeing the final material's density and high-temperature performance. High-pressure molding and prolonged sintering resulted in a dense material structure with low porosity, improving its resistance to molten sand and dust erosion.

[0031] The multi-element rare earth zirconium oxide material provided by this invention has superior corrosion resistance at extreme high temperatures. At the same time, this patented material can remain stable at 1400℃, making it more suitable for the application of high-performance thermal barrier coatings in next-generation ultra-high temperature aero engines or high temperature gas turbines. Attached Figure Description

[0032] Figure 1 Prepared as described in Example 1 of this invention XRD pattern of the material;

[0033] Figure 1a This is a surface microstructure diagram of Example 1;

[0034] Figure 1b Prepared as in Example 1 Corrosion depth map of the material;

[0035] Figure 1c Prepared as in Example 1 Material and Comparative Example 1: Comparison of molten sand and dust corrosion depth of ZrO2-9.5Y2O3-2.25Gd2O3-2.25Yb2O3 multi-element zirconium oxide material reported by NASA;

[0036] Figure 2 Prepared for Example 2 XRD pattern of the material;

[0037] Figure 2a This is a surface microstructure diagram of Example 2;

[0038] Figure 2b Prepared for Example 2 Material and Comparative Example 1: Comparison of molten sand and dust corrosion depth of ZrO2-9.5Y2O3-2.25Gd2O3-2.25Yb2O3 multi-element zirconium oxide material reported by NASA;

[0039] Figure 3 Prepared for Example 3 XRD pattern of the material;

[0040] Figure 3a This is a surface microstructure diagram of Example 3;

[0041] Figure 3b Prepared for Example 3 Comparison of corrosion depth between the material and Comparative Example 2 gadolinium zirconate (Gd2Zr2O7) molten sand dust;

[0042] Figure 3c The image shows the EDS-Mapping diagram of gadolinium zirconate (Gd2Zr2O7) in Comparative Example 2.

[0043] Figure 4 Prepared as described in Example 4 of this invention XRD pattern of the material;

[0044] Figure 4a The surface microstructure diagram is shown in Example 4.

[0045] Figure 4b Prepared for Example 4 Comparison of corrosion depth of material and comparative example 2 gadolinium zirconate (Gd2Zr2O7) molten sand dust. Detailed Implementation

[0046] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0047] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0049] This invention provides a multi-element rare earth zirconia thermal barrier coating material resistant to molten sand and dust erosion. Specifically, the multi-element rare earth zirconia thermal barrier coating material is prepared from nano-Y2O3 powder, nano-A2O3 powder, nano-B2O3 powder and nano-ZrO2 powder as raw materials by high-temperature solid-state reaction method to obtain the required multi-element rare earth zirconia ceramic powder, and then obtained by dry pressing and high-temperature sintering to obtain multi-element rare earth zirconia dense bulk material.

[0050] The nano-Y2O3 powder, nano-A2O3 powder, nano-B2O3 powder, and nano-ZrO2 powder used in the aforementioned multi-element rare earth zirconium oxide thermal barrier coating material for resisting molten sand and dust erosion have a particle size ≤50nm and a purity ≥99.9%.

[0051] The formula for the multi-element rare earth zirconium oxide thermal barrier coating material that resists molten sand and dust erosion is (xY2O3-yA2O3-yB2O3)-(1-x-2y)ZrO2, where x and y represent the molar percentage content of the main rare earth oxide and the auxiliary rare earth oxide, respectively.

[0052] The multi-element rare earth zirconium oxide thermal barrier coating material described above has the characteristics of low thermal conductivity and excellent resistance to molten sand and dust erosion.

[0053] Example 1

[0054] 1) First, based on the predetermined molar ratio of oxide components in the multi-element rare earth zirconium oxide, the required amounts of each raw material for the multi-element ceramic were accurately calculated. Then, nano-sized Y₂O₃, Yb₂O₃ (ytterbium oxide), Gd₂O₃ (gadolinium oxide), and ZrO₂ powders were weighed out. These four nano-powders were then sequentially poured into a ball mill jar, and appropriate amounts of grinding beads and anhydrous ethanol were added as a mixing medium.

[0055] 2) Place the filled ball mill jar into the ball mill and perform ball milling to obtain a uniform mixed slurry;

[0056] 3) The slurry obtained after ball milling is dried to remove excess ethanol, and then sieved to ensure uniform particle size. The treated powder is then subjected to a solid-state reaction at high temperature to synthesize multi-element rare earth zirconium oxide materials;

[0057] 4) The synthesized multi-element rare earth zirconium oxide material is further ground and sieved, and then formed using a dry pressing method. The formed blocks are sintered at high temperature to form a material with resistance to molten sand and dust erosion. A dense multi-element rare earth zirconium oxide ceramic material, wherein the molar percentages of Y2O3, Yb2O3, and Gd2O3 are 27%, 6%, and 6%, respectively, and the remainder is zirconium oxide;

[0058] 5) Grind and polish the surface of the obtained multi-element rare earth zirconium oxide block, mix sand and dust powder with an appropriate amount of anhydrous ethanol and deposit it evenly on the polished ceramic block surface, and after drying, put it into a high-temperature furnace for molten sand and dust corrosion.

[0059] The nano-Y2O3 powder used has a particle size of 30nm and a purity of 99.999%; the nano-Yb2O3 powder has a particle size of 50nm and a purity of 99.9%; the nano-Gd2O3 powder has a particle size of 30nm and a purity of 99.9%; and the nano-ZrO2 powder has a particle size of 20nm and a purity of 99.9%.

[0060] In steps 1) and 2), the ratio of grinding balls, material, and solvent in the grinding jar is 5:1:2, the rotation speed is 145 rpm, and the time is 12 h.

[0061] In step 3), the drying temperature is 85 ℃. The high-temperature solid-phase reaction is first heated to 1000 ℃ at a heating rate of 10 ℃ / min and held for 2 hours, then heated to 1300 ℃ at a heating rate of 5 ℃ / min and held for 2 hours, and finally cooled with the furnace.

[0062] In step 4), the sieve mesh size is 150 mesh. The multi-element powder is dry-pressed into shape using a manual hydraulic press at a uniaxial pressure of 200 MPa for 60 seconds. The blank diameter is 10 mm and the thickness is 1 mm. The sintering temperature is 1550 ℃ and the time is 20 h.

[0063] In step 5), the volume ratio of sand powder to alcohol is 1:2, and the deposition density of sand powder on the surface of the ceramic block is 30 mg / cm³. 2After the sand and dust are deposited, the drying temperature is 85℃. The heating rate of the high-temperature furnace is 10℃ / min below 1000℃ and 5℃ / min between 1000-1400℃. After constant temperature holding, the cooling rate is 5℃ / min above 1000℃. Then the power is turned off and the furnace is cooled.

[0064] Comparative Example 1:

[0065] The difference between the material preparation steps shown in Comparative Example 1 and Example 1 is that:

[0066] In step 1, according to the information reported by NASA regarding the ZrO2-9.5Y2O3-2.25Gd2O3-2.25Yb2O3 multi-component zirconium oxide material, appropriate amounts of nano-sized Y2O3, Yb2O3, Gd2O3, and ZrO2 powders (molar percentages of 9.5%, 2.25%, 2.25%, and 86%, respectively) were weighed out in molar ratio, and the rest was the same as in Example 1.

[0067] Depend on Figure 1 It can be seen that the multi-element rare earth zirconia material synthesized by high-temperature solid-state reaction method has characteristic peaks (111), (220), and (200) of defective fluorite structure; therefore, this multi-element rare earth zirconia ceramic is a defective fluorite phase; such as Figure 1a As shown, the ceramic surface is dense with low porosity; Figure 1b As shown, the corrosion depth of the material after 20 hours of corrosion at 1400℃ was only 5.64 μm, demonstrating a significant improvement in the material's thermal stability and corrosion resistance; Figure 1c As shown, during the molten sand and dust corrosion process at 1400℃, the material in Example 1 first exhibits needle-like (Y-Yb-Gd)2Si2O7 phases on its surface, followed by a subsurface network of apatite phases (RE8Ca2Si6O). 28The material contains rare earth elements (RE) and fluorite phases. The ternary rare earth silicate precipitates on the surface, along with the network-distributed apatite and fluorite phases, collectively resist corrosion from molten sand and dust in the initial stages. At high temperatures, as corrosion time increases, (Y-Yb-Gd)₂Si₂O₇ at the solid-liquid interface continuously grows, eventually forming a dense and continuous protective layer that blocks further erosion by molten sand and dust. This layer is long-lasting and structurally more stable, providing sustained resistance to molten sand and dust erosion. The network-distributed fluorite phase is a product of the decomposition of the ternary rare earth zirconium oxide matrix after corrosion by molten sand and dust, and its resistance to erosion is relatively low. Furthermore, in Comparative Example 1, as molten sand and dust continue to corrode the material, zircon phases precipitate on the surface, and the grain boundaries are gradually dissolved. As corrosion time increases, the molten sand and dust continuously erodes and dissolves along the grain boundaries, penetrating into the material's interior. Compared to Example 1, the zircon phase precipitated on the surface of Comparative Example 1 cannot provide protection against molten sand and dust erosion, and its penetration depth is much greater than that of Example 1 at the same time, indicating that Example 1 exhibits excellent resistance to molten sand and dust penetration.

[0068] Example 2

[0069] 1) First, based on the predetermined molar ratio of oxide components in the multi-element rare earth zirconium oxide, the required amount of each raw material for the multi-element ceramic is accurately calculated. Then, nano-sized Y2O3, Dy2O3, Er2O3, and ZrO2 powders are weighed out respectively. These four nano-powders are then poured into a ball mill jar in sequence, and appropriate amounts of grinding beads and anhydrous ethanol are added as a mixing medium.

[0070] 2) Place the filled ball mill jar into the ball mill and perform ball milling to obtain a uniform mixed slurry;

[0071] 3) The mixed slurry obtained after ball milling is dried to remove excess ethanol, and then sieved to ensure uniform particle size; the treated powder is then subjected to a solid-phase reaction at high temperature to synthesize multi-element rare earth zirconium oxide materials.

[0072] 4) The synthesized multi-element rare earth zirconium oxide powder was further ground and sieved, and then formed using a dry pressing method. The formed blocks were sintered at high temperature to form a structure with resistance to molten sand and dust erosion. A dense multi-element rare earth zirconium oxide ceramic material, wherein the molar percentages of Y2O3, Dy2O3 and Er2O3 are 24%, 5% and 5% respectively, and the remainder is zirconium oxide;

[0073] 5) Grind and polish the surface of the obtained multi-element rare earth zirconium oxide block, mix sand and dust powder with an appropriate amount of anhydrous ethanol and deposit it evenly on the polished ceramic block surface, and after drying, put it into a high-temperature furnace for molten sand and dust corrosion.

[0074] The nano-Y2O3 powder used has a particle size of 30nm and a purity of 99.999%; the nano-Dy2O3 powder has a particle size of 50nm and a purity of 99.9%; the nano-Er2O3 powder has a particle size of 50nm and a purity of 99.9%; and the nano-ZrO2 powder has a particle size of 20nm and a purity of 99.9%.

[0075] In steps 1) and 2), the ratio of grinding balls, material, and solvent in the grinding jar is 3:1:2, the rotation speed is 130 rpm, and the time is 24 hours.

[0076] In step 3), the drying temperature is 82 ℃. The high-temperature solid-phase reaction is first heated to 800 ℃ and held for 1 hour, then heated to 1200 ℃ and held for 1 hour, and finally cooled with the furnace.

[0077] In step 4), the sieve mesh size is 100 mesh. The multi-element powder is dry-pressed into shape using a manual hydraulic press at a uniaxial pressure of 200 MPa for 30 seconds. The blank diameter is 15 mm and the thickness is 3 mm. The sintering temperature is 1500 ℃ and the time is 22 h.

[0078] In step 5), the volume ratio of powder to alcohol is 1:2, and the deposition density of sand and dust on the surface of the ceramic block is 30 mg / cm³. 2 After the sand and dust are deposited, the drying temperature is 85℃. The heating rate of the high-temperature furnace is 10℃ / min below 1000℃ and 5℃ / min between 1000-1400℃. After constant temperature holding, the cooling rate is 5℃ / min above 1000℃. Then the power is turned off and the furnace is cooled.

[0079] Depend on Figure 2 It can be seen that the multi-element rare earth zirconia material synthesized by high-temperature solid-state reaction method has characteristic peaks (111), (220), and (200) of defective fluorite structure; therefore, this multi-element rare earth zirconia ceramic is a defective fluorite phase; such as Figure 2a As shown, the ceramic surface is dense with low porosity; Figure 2bAs shown, during the corrosion process of the material in Example 2 at 1400℃ by molten sand and dust, granular (Y-Dy-Er)₂Si₂O₇ and a subsurface network of apatite and fluorite phases initially precipitate on the surface. The ternary rare earth silicate precipitates and the network of apatite and fluorite phases on the surface work together to resist corrosion from the molten sand and dust in the initial stage. At high temperatures, as corrosion time increases, the (Y-Dy-Er)₂Si₂O₇ at the solid-liquid interface continuously grows, eventually forming a dense and continuous protective layer that blocks further erosion by the molten sand and dust. This layer is long-lasting and structurally more stable, providing continuous resistance to molten sand and dust corrosion. In addition, a small amount of zircon phase precipitates in some areas due to Zr dissolving in the molten sand and dust at the interface. The network of fluorite phase is a product of the decomposition of the ternary rare earth zirconium oxide matrix after corrosion by the molten sand and dust, and its resistance to corrosion is relatively low. Furthermore, in Comparative Example 1, as the molten sand and dust continued to corrode, zircon phase precipitated on the surface, and the grain boundaries were gradually dissolved. As the corrosion time increased, the molten sand and dust continued to erode and dissolve along the grain boundaries, penetrating into the interior of the material. Compared to Example 2, the material in Comparative Example 1 could not provide protection against molten sand and dust erosion, and the penetration depth was much greater than that in Example 2 at the same time, indicating that Example 2 had excellent resistance to molten sand and dust penetration.

[0080] Example 3

[0081] 1) First, based on the predetermined molar ratio of oxide components in the multi-element rare earth zirconium oxide, the required amount of each raw material for the multi-element ceramic is accurately calculated. Then, nano-sized Y2O3, Dy2O3, Yb2O3, and ZrO2 powders are weighed out respectively. These four nano-powders are then poured into a ball mill jar in sequence, and appropriate amounts of grinding beads and anhydrous ethanol are added as a mixing medium.

[0082] 2) Place the filled ball mill jar into the ball mill and perform ball milling to obtain a uniform mixed slurry;

[0083] 3) The slurry obtained after ball milling is dried to remove excess ethanol, and then sieved to ensure uniform particle size. The treated powder is then subjected to a solid-state reaction at high temperature to synthesize multi-element rare earth zirconium oxide materials;

[0084] 4) The synthesized multi-element rare earth zirconium oxide material is further ground and sieved, and then formed using a dry pressing method. The formed blocks are sintered at high temperature to form a material with resistance to molten sand and dust erosion. A dense multi-element rare earth zirconium oxide ceramic material, wherein the molar percentages of Y2O3, Dy2O3, and Yb2O3 are 24%, 5%, and 5%, respectively, and the remainder is zirconium oxide;

[0085] 5) Grind and polish the surface of the obtained multi-element rare earth zirconium oxide block, mix sand and dust powder with an appropriate amount of anhydrous ethanol and deposit it evenly on the polished ceramic block surface, and after drying, put it into a high-temperature furnace for molten sand and dust corrosion.

[0086] The nano-Y2O3 powder used has a particle size of 30nm and a purity of 99.999%; the nano-Dy2O3 powder has a particle size of 50nm and a purity of 99.9%; the nano-Yb2O3 powder has a particle size of 50nm and a purity of 99.9%; and the nano-ZrO2 powder has a particle size of 20nm and a purity of 99.9%.

[0087] In steps 1) and 2), the ratio of grinding balls, material, and solvent in the grinding jar is 6:1:3, the rotation speed is 160 rpm, and the time is 12 hours.

[0088] In step 3), the drying temperature is 85 ℃. The high-temperature solid-phase reaction is first heated to 1000 ℃ at a heating rate of 10 ℃ / min and held for 4 hours, then heated to 1400 ℃ at a heating rate of 5 ℃ / min and held for 4 hours, and finally cooled with the furnace.

[0089] In step 4), the sieve mesh size is 160 mesh. The multi-element powder is dry-pressed into shape using a manual hydraulic press at a uniaxial pressure of 200 MPa for 30 seconds. The blank diameter is 20 mm and the thickness is 4 mm. The sintering temperature is 1600 ℃ and the time is 24 h.

[0090] In step 5), the volume ratio of powder to alcohol is 1:2, and the deposition density of sand and dust on the surface of the ceramic block is 30 mg / cm³. 2 After the sand and dust are deposited, the drying temperature is 85℃. The heating rate of the high-temperature furnace is 10℃ / min below 1000℃ and 5℃ / min between 1000-1400℃. After constant temperature holding, the cooling rate is 5℃ / min above 1000℃. Then the power is turned off and the furnace is cooled.

[0091] Comparative Example 2:

[0092] The difference between the material preparation steps shown in Comparative Example 2 and Example 3 is that:

[0093] In step 1, nano-sized Gd2O3 and ZrO2 powders were weighed according to the stoichiometric ratio of gadolinium zirconate (Gd2Zr2O7) at a molar ratio of 1:2, and the rest was the same as in Example 3.

[0094] Depend on Figure 3 It can be seen that the multi-element rare earth zirconia material synthesized by high-temperature solid-state reaction method has characteristic peaks (111), (220), and (200) of defective fluorite structure; therefore, this multi-element rare earth zirconia ceramic is a defective fluorite phase; such as Figure 3aAs shown, the ceramic surface is dense with low porosity; Figure 3b As shown, in Example 3, during the corrosion process with molten sand and dust at 1400℃, granular (Y-Dy-Yb)₂Si₂O₇ and a subsurface network of apatite and fluorite phases initially precipitate on the surface. The ternary rare earth silicate precipitates and the network of apatite and fluorite phases on the surface work together to resist corrosion from the molten sand and dust in the initial stage. At high temperatures, as corrosion time increases, the (Y-Dy-Yb)₂Si₂O₇ at the solid-liquid interface continuously grows, eventually forming a dense and continuous protective layer that blocks further erosion by the molten sand and dust. This layer is long-lasting and structurally more stable, providing continuous resistance to molten sand and dust corrosion. In addition, in some areas, a small amount of zircon phase (ZrSiO₄) precipitates at the interface due to Zr dissolving in the molten sand and dust. The network of fluorite phase is a product of the decomposition of the ternary rare earth zirconium oxide matrix after corrosion by the molten sand and dust, and its resistance to corrosion is relatively low. Furthermore, Comparative Example 2 shows that there is a large corrosion depth in the early stages of corrosion. As the molten sand and dust continue to erode, scattered zircon phases (ZrSiO4) precipitate on the surface, while the subsurface layer is composed of alternating networks of gadolinium silicate and gadolinium-doped zirconium oxide. Figure 3c As shown, surface scanning spectroscopy reveals that a large amount of silicon in the molten sand penetrates into the matrix material, exhibiting poor resistance to corrosion. In the upper half of the corrosion zone, the dissolution of grain boundaries accelerates the reaction and penetration of the molten sand into the matrix, resulting in more severe corrosion. In the lower half of the corrosion zone, aluminum enrichment is observed, forming a three-phase coexistence region near the uncorroded area of ​​the matrix, consisting of gadolinium aluminum perovskite, gadolinium silicate, and gadolinium-doped zirconium oxide. With increasing corrosion time, the molten sand continuously erodes and dissolves the matrix material through reaction, leading to more severe corrosion. In Comparative Example 2, the reacted precipitates, whether zircon, gadolinium silicate, or gadolinium aluminum perovskite, did not exhibit resistance to the molten sand. Compared to Example 3, they failed to provide protection against molten sand erosion, and their penetration depth was significantly greater than that of Example 3 within the same timeframe, indicating that the material in Example 3 exhibits excellent resistance to molten sand penetration.

[0095] Example 4

[0096] 1) First, based on the predetermined molar ratio of oxide components in the multi-element rare earth zirconium oxide, the required amount of each raw material for the multi-element ceramic is accurately calculated. Then, nano-sized Y2O3, Yb2O3, Gd2O3, and ZrO2 powders are weighed out respectively. These four nano-powders are then poured into a ball mill jar in sequence, and appropriate amounts of grinding beads and anhydrous ethanol are added as a mixing medium.

[0097] 2) Place the filled ball mill jar into the ball mill and perform ball milling to obtain a uniform mixed slurry;

[0098] 3) The mixed slurry obtained after ball milling is dried to remove excess ethanol, and then sieved to ensure uniform particle size. The treated powder is then subjected to a solid-phase reaction at high temperature to synthesize multi-element rare earth zirconium oxide powder;

[0099] 4) The synthesized multi-element rare earth zirconium oxide powder was further ground and sieved, and then formed using a dry pressing method. The formed blocks were sintered at high temperature to form a structure with resistance to molten sand and dust erosion. A dense multi-element rare earth zirconium oxide ceramic material, wherein the molar percentages of Y2O3, Yb2O3, and Gd2O3 are 30%, 7%, and 7%, respectively, and the remainder is zirconium oxide;

[0100] 5) Grind and polish the surface of the obtained multi-element rare earth zirconium oxide block, mix sand and dust powder with an appropriate amount of anhydrous ethanol and deposit it evenly on the polished ceramic block surface, and after drying, put it into a high-temperature furnace for molten sand and dust corrosion.

[0101] The nano-Y2O3 powder used has a particle size of 30nm and a purity of 99.999%; the nano-Yb2O3 powder has a particle size of 50nm and a purity of 99.9%; the nano-Gd2O3 powder has a particle size of 30nm and a purity of 99.9%; and the nano-ZrO2 powder has a particle size of 20nm and a purity of 99.9%.

[0102] In steps 1) and 2), the ratio of grinding balls, material, and solvent in the grinding jar is 4:1:2, the rotation speed is 145 rpm, and the time is 15 h.

[0103] In step 3), the drying temperature is 90℃. The high-temperature solid-phase reaction is first heated to 1000℃ at a heating rate of 10℃ / min and held for 2 hours, then heated to 1300℃ at a heating rate of 5℃ / min and held for 2 hours, and finally cooled with the furnace.

[0104] In step 4), the sieve mesh size is 200 mesh. The multi-element powder is dry-pressed into shape using a manual hydraulic press at a uniaxial pressure of 200 MPa for 60 seconds. The diameter of the green blank is 25.4 mm and the thickness is 2 mm. The sintering temperature is 1580 ℃ and the time is 20 h.

[0105] In step 5), the volume ratio of powder to alcohol is 1:2, and the deposition density of sand and dust on the surface of the ceramic block is 30 mg / cm³. 2 After the sand and dust are deposited, the drying temperature is 90℃. The heating rate of the high-temperature furnace is 10℃ / min below 1000℃ and 5℃ / min between 1000-1400℃. After constant temperature holding, the cooling rate is 5℃ / min above 1000℃. Then the power is turned off and the furnace is cooled.

[0106] The difference between the material preparation steps shown in Comparative Example 3 and Example 4 is as follows:

[0107] In step 1, nano-sized Gd2O3 and ZrO2 powders were weighed according to the stoichiometric ratio of gadolinium zirconate (Gd2Zr2O7) at a molar ratio of 1:2, and the rest was the same as in Example 4.

[0108] Depend on Figure 4 It can be seen that the multi-element rare earth zirconia material synthesized by high-temperature solid-state reaction method has characteristic peaks (111), (220), and (200) of defective fluorite structure; therefore, this multi-element rare earth zirconia ceramic is a defective fluorite phase; such as Figure 4a As shown, the ceramic surface is dense with low porosity; Figure 4b As shown, during the corrosion process of the material in Example 4 at 1400℃ by molten sand and dust, granular (Y-Gd-Yb)₂Si₂O₇ and a subsurface network of apatite and fluorite phases initially precipitate on the surface. The ternary rare earth silicate precipitates on the surface, along with the network of apatite and fluorite phases, collectively resist corrosion from the molten sand and dust in the initial stage. At high temperatures, as corrosion time increases, the (Y-Dy-Yb)₂Si₂O₇ at the solid-liquid interface continuously grows, eventually forming a dense and continuous protective layer that blocks further erosion by the molten sand and dust. This layer is long-lasting and structurally more stable, providing continuous resistance to molten sand and dust corrosion. In addition, in some areas, a small amount of zircon phase (ZrSiO₄) precipitates at the interface due to the dissolution of Zr in the molten sand and dust. The network of fluorite phase is a product of the decomposition of the ternary rare earth zirconium oxide matrix after corrosion by the molten sand and dust, and its resistance to corrosion is relatively low. Furthermore, Comparative Example 2 shows a large corrosion depth even in the early stages of corrosion. With the continuous erosion by molten sand and dust, scattered zircon phases (ZrSiO4) precipitate on the surface, while the subsurface layer consists of alternating networks of gadolinium silicate and gadolinium-doped zirconium oxide. In the upper half of the corroded area, the dissolution of grain boundaries accelerates the reaction and penetration of molten sand and dust into the matrix, resulting in more severe erosion. In the lower half of the corroded area, aluminum enrichment is observed, forming a three-phase coexistence zone near the uncorroded area of ​​the matrix, consisting of gadolinium aluminum perovskite, gadolinium silicate, and gadolinium-doped zirconium oxide. As corrosion time increases, the molten sand and dust continuously erode and dissolve the matrix material through reaction, leading to more severe corrosion. In Comparative Example 2, neither the zircon phase, gadolinium silicate, nor gadolinium aluminum perovskite structure exhibited resistance to molten sand and dust. Compared to Example 4, it failed to provide protection against molten sand and dust erosion, and its penetration depth was significantly greater than that of Example 4 within the same timeframe, indicating that Example 4 demonstrated excellent resistance to molten sand and dust penetration.

[0109] Compared to reaction-barrier gadolinium zirconate (Gd₂Zr₂O₇) materials with excellent CMAS resistance, the defective fluorite structure in the ternary rare-earth zirconium oxide prepared in this invention can facilitate ion migration at high temperatures by providing oxygen vacancies, thereby forming a stable and dense barrier layer (such as a calcium-rich apatite network layer and a ternary rare-earth silicate layer) at the material interface. These barrier layers can effectively prevent the penetration of molten sand and dust, reduce grain boundary corrosion, and give the material superior resistance to molten sand and dust erosion, meeting the material selection requirements for high-performance thermal barrier coating materials.

[0110] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion, characterized in that, The chemical composition of the multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion is: (xY2O3-yA2O3-yB2O3)-(1-x-2y)ZrO2, wherein the molar percentage of x is: 17%≤x≤31%, the molar percentage of y is: 1.5%<y<8.5%, and 34%≤(x+2y)≤46%; The multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion includes zirconium oxide, primary rare earth oxide Y2O3, secondary rare earth oxide A2O3, and secondary rare earth oxide B2O3. Among them, the rare earth elements A or B in the secondary rare earth oxides A2O3 and B2O3 include any one of Gd, Dy, Yb, and Er. The primary rare earth oxide Y2O3 and the two secondary rare earth oxides are in a non-equimolar ratio, while the secondary rare earth oxides are in an equimolar ratio.

2. The multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion according to claim 1, characterized in that, The particle size of the multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion is less than 0.15 mm.

3. A method for preparing a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion as described in any one of claims 1 to 2, characterized in that, Includes the following steps: 1) Weigh Y2O3, A2O3, B2O3 and ZrO2 powders according to the molar ratio of oxide components and ball mill them to obtain a mixed slurry; 2) The above mixed slurry is dried and sieved to obtain powder. The powder is then subjected to a solid-phase reaction at high temperature to synthesize a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion.

4. The method for preparing a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion according to claim 3, characterized in that, In step 1), the Y2O3, A2O3, B2O3 and ZrO2 powders are nano-sized powders with a particle size ≤50nm and a purity ≥99.9%.

5. The method for preparing a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion according to claim 3, characterized in that, In step 1), the ball milling conditions are as follows: the powder is added to the ball milling jar, and an appropriate amount of grinding beads and solvent are added as the mixing medium, wherein the mass ratio of grinding beads, powder and solvent is 3:1:2 ~ 6:1:3, the rotation speed is 130~160 rpm, and the time is 12~24 h.

6. The method for preparing a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion according to claim 3, characterized in that, In step 2), the high-temperature solid-phase reaction is first heated to 800~1000℃ and held for 1~4 h, then heated to 1200~1400℃ and held for 1~4 h, and finally cooled with the furnace.

7. The method for preparing a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion according to claim 3, characterized in that, The multi-element rare earth zirconium oxide material in step 2) is then ground and sieved, and then formed by dry pressing. The formed block is sintered at high temperature to obtain dense multi-element rare earth zirconium oxide ceramic block material.

8. The method for preparing a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion according to claim 7, characterized in that, Dry pressing includes: a time of 30-60 seconds, a blank diameter of 10 mm-25.4 mm, and a thickness of not less than 1 mm.

9. The method for preparing a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion according to claim 7, characterized in that, The sintering temperature is 1500~1600℃ and the time is not less than 20 h.

10. The method for preparing a multi-element rare earth zirconium oxide material resistant to molten sand and dust erosion according to claim 7, characterized in that, The sieve mesh size is 100-200 mesh.

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