Partially yttrium-stabilized zirconia powder with a multi-modal pore structure and a method for producing the same

Abstract

The application provides a partially yttrium stabilized zirconia powder with a multi-pore structure and a preparation method thereof. A slurry is prepared by adding a pore-forming agent and adjusting the mass ratio of a nano yttrium stabilized zirconia powder, the pore-forming agent powder, a dispersant solution and deionized water, then the slurry is spray granulated and corresponding parameters are adjusted, and finally a partially yttrium stabilized zirconia powder with a multi-pore structure is prepared through a vacuum drying and debinding calcination process. Through optimization of atmospheric plasma spraying parameters, such as setting the plasma working voltage and current, the powder feeding parameters and the powder feeding speed, and adjusting the powder feeding gas volume, a coating with a composite pore is prepared. The powder has the advantages of a multi-stage pore structure, an internal support skeleton, good sphericity and sprayability, etc. by reasonably configuring the pore-forming agent and the dispersant in the precursor slurry and through processes such as spray granulation, vacuum drying and debinding calcination. The powder can be used to prepare a coating with a multi-pore composite structure, and the stability of the coating is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of thermal protection application technology, and more specifically, to a partially yttrium-stabilized zirconia powder with a multi-morphological porous structure and its preparation method, for use in the preparation of ceramic layers on the surface of thermal barrier coatings. Background Technology

[0002] Yttrium-stabilized zirconia powder is a key material for thermal protection of hot-end components in aero-engines and gas turbines, and is mainly prepared as a thermal barrier coating ceramic layer using plasma spraying technology. However, ceramic layers prepared using traditional dense powders are no longer sufficient to break through the thermal barrier coating's heat resistance limit. Therefore, designing powder structures to create coatings with different pore structures has become a feasible approach to further improve the heat resistance limit of thermal barrier coatings.

[0003] Existing methods involve designing hollow structures for powders, typically including spray granulation combined with heat treatment and sintering with binders. For example, patent CN111566047A provides a method for manufacturing hollow silica particles by adjusting the pH of the emulsion and adding different silicon sources. This method can produce particles with hollow characteristics, but there is still room for optimization in terms of the consistency of the shell thickness and the powder's resistance to breakage during spraying. Another patent, CN104129991B, discloses a method for preparing hollow spherical YSZ particles with a particle size of 10-106µm using a precursor slurry containing foaming organic matter through spray drying and subsequent heat treatment. This method has a relatively simple process, is cost-effective, and has certain industrialization potential. However, the particles obtained in this patent have a hollow structure, lack an internal supporting framework, and have insufficient structural stability. Summary of the Invention

[0004] Existing hollow structure powder designs feature an inner hollow shell structure. On one hand, because hollow structure powders lack internal support, they break and splatter during spraying, resulting in low powder utilization. On the other hand, while the hollow structure increases coating porosity during coating preparation, thereby improving heat resistance, the uniform pore size and structure lead to instability at high temperatures, resulting in a significant decrease in coating thermal stability.

[0005] To overcome the shortcomings of existing technologies, this invention provides a partially yttrium-stabilized zirconia powder with a multi-morphological porous structure and its preparation method. This invention successfully prepares a partially yttrium-stabilized zirconia powder with a multi-morphological porous structure through steps such as preparing a precursor slurry, spray granulation, and debinding and calcination. This powder contains pores formed by a pore-forming agent, pores between agglomerated nanoparticles, and pores between nanoparticles, and possesses an internal supporting structure. It is not easily broken during spraying and can be used to prepare coatings with a composite porous structure, significantly improving the thermal stability of the coating.

[0006] This invention is achieved through the following technical solution: a method for preparing partially yttrium-stabilized zirconia powder with a multi-morphological porous structure, characterized by comprising the following steps:

[0007] Step S1: Preparation of spray granulation slurry; mix nano-yttrium stabilized zirconia powder, pore-forming agent powder, dispersant solution and deionized water, with the mass ratio of each component being (10~30):(2~10):(1~8):(20~40), the nano-yttrium stabilized zirconia powder having a particle size range of 5~100nm and a yttrium element content of 3~15%; the pore-forming agent is a high molecular weight polymer composed of C, H and O elements with an ignition point of 200~1000 degrees Celsius and a particle size of 0.5~30μm; use ammonia water at a mass ratio of 1:10 to adjust the pH of the slurry to between 7 and 10;

[0008] Step S2: Spray granulation slurry mixing; mix the spray granulation slurry prepared in step S1 with zirconia grinding balls at a ball-to-material ratio of (1~3):(3~5); use a planetary ball mill for ball milling at a speed of 100~200 rpm for 2~8 hours to obtain a uniformly dispersed suspension slurry; then add 3%~5% binder and 0.3%~0.5% solid phase mass of 0.1~0.3% n-octanol to the suspension slurry, and finally put it into a planetary ball mill for further ball milling for 4~12 hours to obtain a viscous spray granulation slurry;

[0009] Step S3: Spray drying to prepare agglomerated powder; The spray drying process is as follows: Spray drying experiment is carried out using an airflow spray granulator, wherein the air pressure is between 0.1 and 0.2 MPa, the inlet air temperature is between 100 and 200°C, and the feeding rate is between 10 and 30 rpm; Finally, the collected agglomerated powder is placed in a vacuum drying oven and kept at that temperature for 30 to 120 minutes.

[0010] Step S4: Degreasing and calcination treatment of agglomerated powder; The degreasing and calcination process includes the following steps: First, raise the temperature to 100℃ and hold for 30~60 minutes; then, raise the temperature to 500~600℃ at a rate of 5℃ / min and hold for 1~4 hours; finally, heat the powder to 800~1200℃ and hold for 2~6 hours. The cooling method after calcination is furnace cooling, resulting in a partially yttrium-stabilized zirconia powder with a multi-morphological porous structure.

[0011] As a preferred embodiment, the mass ratio of nano-yttrium stabilized zirconium oxide powder, pore-forming agent powder, dispersant solution and deionized water in step S1 is (15~25):(3~6):(2~5):(25~35), the particle size range of nano-yttrium stabilized zirconium oxide is 5~40nm, and the yttrium element content is 3~9%; the pore-forming agent is starch, polystyrene, or polymethyl methacrylate powder.

[0012] As a preferred embodiment, in step S2, the spray granulation slurry prepared in step S1 is mixed with zirconia grinding balls at a ball-to-material ratio of (1~3):(3~5); a planetary ball mill is used for ball milling at a speed of 120~180 rpm for 1~4 hours to obtain a uniformly dispersed suspension slurry; finally, the slurry is placed in the planetary ball mill for further ball milling for 6~8 hours to obtain a viscous spray granulation slurry.

[0013] As a preferred embodiment, the air pressure in step S3 is between 0.15 and 0.2 MPa, the inlet air temperature is between 140 and 180°C, and the feeding rate is between 15 and 20 rpm; the material is kept in the vacuum drying oven for 60 to 90 minutes.

[0014] As a preferred option, in step S4, the powder is heated to 1000-1100℃ and held for 3-5 hours.

[0015] A partially yttrium-stabilized zirconia powder with a multimorphic porous structure is prepared by the above-mentioned method for preparing partially yttrium-stabilized zirconia powder with a multimorphic porous structure.

[0016] By employing the above technical solutions, this invention has the following beneficial effects compared to existing technologies:

[0017] To address the problems of single pore type, lack of internal support structure, and poor stability in existing technologies, this invention proposes a method for preparing partially yttrium-stabilized zirconia powder with multi-morphological pore structure.

[0018] (1) The powder forms a multi-level pore structure, an internal support skeleton, and good sphericity and sprayability by rationally configuring pore-forming agents and dispersants in the precursor slurry and then performing spray granulation, vacuum drying and degreasing calcination processes.

[0019] (2) This powder can be used to prepare coatings with porous composite structures, and the stability of the coating is significantly improved.

[0020] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0022] Figure 1 This is a flowchart of the powder preparation process;

[0023] Figure 2 The image shows the surface and cross-sectional morphology of partially yttrium-stabilized zirconia powder with a multi-morphological porous structure.

[0024] Figure 3 It is a coating composite porous structure;

[0025] Figure 4 This refers to the change in the elastic modulus of the coating during thermal exposure.

[0026] Figure 5 The changes in porosity during the thermal exposure of the coating: left shows the preparation of porous powder, and right shows the preparation of hollow powder. Detailed Implementation

[0027] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0029] The following is combined Figures 1 to 5 The present invention provides a detailed description of the partially yttrium-stabilized zirconia powder with a multimorphic porous structure and its preparation method according to embodiments of the present invention.

[0030] like Figure 1 As shown, this invention proposes a method for preparing partially yttrium-stabilized zirconia powder with a multi-morphological porous structure. Specifically, it involves adding a pore-forming agent to a slurry and then calcining it to prepare agglomerated powder with a special porous structure. This invention uses a method of adding a pore-forming agent and adjusting the mass ratio of nano-yttrium-stabilized zirconia powder, pore-forming agent powder, dispersant solution, and deionized water to prepare the slurry. This slurry is then spray-granulated with adjusted parameters, and finally prepared through vacuum drying and degreasing calcination processes to obtain partially yttrium-stabilized zirconia powder with a multi-morphological porous structure. By optimizing atmospheric plasma spraying parameters, such as setting the plasma working voltage and current, powder feeding parameters and speed, and adjusting the powder feeding gas volume, a coating with composite pores is obtained.

[0031] Specifically, the following steps are included:

[0032] Step S1: Preparation of spray granulation slurry. Nano-yttrium stabilized zirconia powder, pore-forming agent powder, dispersant solution, and deionized water are mixed in a mass ratio of (10~30):(2~10):(1~8):(20~40), preferably (15~25):(3~6):(2~5):(25~35). The yttrium stabilized nano-zirconia has a particle size range of 5~100nm (preferably 5~40nm) and a yttrium content of 3~15% (preferably 3~9%). The pore-forming agent is a high-molecular-weight polymer composed of C, H, and O elements with a flash point of 200~1000 degrees Celsius and a particle size of 0.5~30μm, preferably starch, polystyrene, or polymethyl methacrylate powder. Ammonia water is used at a mass ratio of 1:10 to adjust the pH of the slurry to between 7 and 10.

[0033] Step S2: Spray granulation slurry mixing. The prepared slurry is mixed with a certain number of zirconia grinding balls at a ball-to-material ratio of (1~3):(3~5). A planetary ball mill is used for ball milling at a speed of 100~200 rpm (preferably 120~180 rpm) for 2~8 hours (preferably 1~4 hours) to obtain a uniformly dispersed suspension slurry. Then, 3%~5% of a binder and 0.3%~0.5% of n-octanol (by solid mass) are added to the suspension slurry. During the addition process, the slurry needs to be rapidly stirred to prevent the binder from agglomerating. Finally, the mixture is placed back into the planetary ball mill and milled for another 4~12 hours (preferably 6~8 hours) to obtain a spray granulation slurry with a certain viscosity.

[0034] Step S3: Spray drying to prepare agglomerated powder. The spray drying process is as follows: a spray drying experiment is conducted using an airflow spray granulator, wherein the air pressure is between 0.1 and 0.2 MPa (preferably 0.15 to 0.2 MPa), the inlet air temperature is between 100 and 200°C (preferably 140 to 180°C), and the feeding rate is between 10 and 30 rpm (preferably 15 to 20 rpm). Finally, the collected agglomerated powder is placed in a vacuum drying oven and kept at that temperature for 30 to 120 minutes (preferably 60 to 90 minutes) to remove the moisture adhering to the powder.

[0035] Step S4: Degreasing and calcination treatment of agglomerated powder. The main steps of the degreasing and calcination process are as follows: First, raise the temperature to 100℃ and hold for 30-60 minutes. Then, raise the temperature to 500-600℃ at a rate of 5℃ / min and hold for 1-4 hours; finally, heat the powder to 800-1200℃ (preferably 1000-1100℃) and hold for 2-6 hours (preferably 3-5 hours). The cooling method after calcination is furnace cooling, resulting in a partially yttrium-stabilized zirconia powder with a multi-morphological porous structure, such as... Figure 2 As shown.

[0036] Step S5: Coating preparation using multi-morphological porous powder. The substrate with the prepared adhesive layer is fixed on the worktable, and sprayed using an atmospheric plasma spraying device. The following parameters are optimized to achieve stable spraying: The plasma working voltage (60~90V) and current (500~600A) are set, and the powder feeding parameters must be synchronized. The powder feeding speed is controlled within the range of 10~30g / min, and the powder feeding gas volume (4~6L / min) is adjusted to ensure uniform powder delivery into the plasma jet core area. Precise control of the spray gun trajectory is required during spraying: the spraying distance is maintained at 100~200mm to improve particle melting effect; the spray gun moving speed is adjusted to 10~30mm / s to ensure coating continuity. Finally, a coating with composite pores is obtained, such as... Figure 3 As shown.

[0037] Step S6: Sintering experiments were conducted on the coatings prepared from the two powders, and the changes in their mechanical properties during heat exposure were analyzed. An SX2 series box-type resistance furnace was used for the sintering experiments. The heat exposure temperature was set to 1100℃, and the experimental time was divided into five stages: 1h, 5h, 20h, 50h, and 100h. First, the samples and crucibles were ultrasonically cleaned and dried. Then, the resistance furnace was heated to the set temperature at a heating rate of 5℃ / min. The coating samples were marked and placed in the resistance furnace. Timing began after the furnace temperature stabilized. The coating samples were removed at the set temperature intervals and placed on refractory bricks to cool. After polishing the cross-section of the coating samples, the microstructure morphology was observed using a scanning electron microscope, and the changes in the elastic modulus of the two coatings during heat exposure were analyzed. Compared with dense ceramics, if the increase in the elastic modulus of the porous coating is small after long-term heat exposure, it indicates that the spherical pore structure inside the coating effectively suppresses the high-temperature sintering effect, slows down the degradation of mechanical properties caused by sintering densification, and thus endows the coating with excellent high-temperature structural stability.

[0038] Example 1

[0039] In this embodiment, nano-yttrium stabilized zirconia powder, pore-forming agent powder, dispersant solution, and deionized water are mixed at a mass ratio of 15:3:2:25. The yttrium stabilized nano-zirconia particles have a particle size range of 5-20 nm and a yttrium content of 3%. The pore-forming agent is a polymer composed of C, H, and O elements with a particle size of 0.5-10 μm. Starch is selected as the pore-forming agent, and ammonia water is used at a mass ratio of 1:10 to adjust the pH of the slurry to between 7 and 10.

[0040] Preparation of multi-scale porous zirconia nanospheres by spray granulation: A prepared slurry was mixed with a certain number of zirconia grinding balls at a ball-to-material ratio of 1:2. The mixture was then ball-milled using a planetary ball mill at 120 rpm for 2 hours to obtain a uniformly dispersed suspension. Next, 3% binder and 0.3% (by weight of solids) 0.1% n-octanol were added to the suspension. During the addition process, the slurry was rapidly stirred to prevent binder agglomeration. Finally, the mixture was placed back into the planetary ball mill and ball-milled for another 6 hours to obtain a spray-granulated slurry with a certain viscosity.

[0041] Spray granulation experiment: Spray drying was performed using an airflow spray granulator with an air pressure of 0.15 MPa, an inlet air temperature of 150℃, and a feed rate of 15 rpm. Finally, the collected agglomerated powder was placed in a vacuum drying oven and kept at that temperature for 60 minutes to remove any adhering moisture.

[0042] Degreasing and calcination treatment of agglomerated powder: The temperature is raised to 100℃ and held for 30 minutes; then, the temperature is raised to 500℃ at a rate of 5℃ / min and held for 2 hours; finally, the powder is heated to 1000℃ and held for 3 hours. The cooling method after calcination is furnace cooling, resulting in a partially yttrium-stabilized zirconia powder with a multimorphic porous structure.

[0043] Coating Preparation: The substrate with the adhesive layer prepared was fixed on the worktable, and spraying was performed using an atmospheric plasma spraying system. The plasma working voltage was set to 60V, the working current to 500A, and the powder feeding parameters were synchronized and matched. The powder feeding speed was controlled at 15g / min, and the powder feeding gas flow rate was adjusted to 4L / min to ensure that the powder was uniformly delivered into the core area of ​​the plasma jet. Precise control of the spray gun trajectory was maintained during spraying: the spraying distance was kept at 120mm to improve the particle melting effect; the spray gun moving speed was adjusted to 15mm / s to ensure coating continuity. The final product was a coating with composite pores.

[0044] Figure 4 The change in elastic modulus of the coating prepared in this embodiment compared to coatings prepared from hollow and dense powders during thermal exposure. Figure 4 It can be seen that in the initial stage of heat exposure (0-20 hours), the elastic modulus of all three coatings increased rapidly and tended to stabilize after 50 hours. The hollow and dense powder coatings had lower elastic moduli than the composite porous coating in the prepared state, but after 20 hours of heat exposure, their elastic moduli increased significantly, while the composite porous coating only increased by 37.4%. After 50 hours of heat exposure, the composite porous coating increased from 123.46 GPa to 186.8 GPa, significantly lower than the other two. This is because the spherical pore structure in the composite porous coating helps to mitigate the mechanical property degradation caused by sintering, allowing it to maintain good mechanical properties even under long-term heat exposure.

[0045] Example 2

[0046] In this embodiment, nano-yttrium stabilized zirconia powder, pore-forming agent powder, dispersant solution, and deionized water are mixed at a mass ratio of 25:4:3:30. The yttrium stabilized nano-zirconia particles have a diameter range of 20-40 nm and a yttrium content of 9%. The pore-forming agent is a polymer composed of C, H, and O elements with a particle size of 10-20 μm. Starch is selected as the pore-forming agent, and ammonia water is used at a mass ratio of 1:10 to adjust the pH of the slurry to between 7 and 10.

[0047] Preparation of multi-scale porous zirconia nanospheres by spray granulation: A prepared slurry was mixed with a certain number of zirconia grinding balls at a ball-to-material ratio of 1:3. The mixture was then ball-milled using a planetary ball mill at 170 rpm for 4 hours to obtain a uniformly dispersed suspension. Next, 5% binder and 0.5% (by weight of solids) 0.3% n-octanol were added to the suspension. During the addition process, the slurry was rapidly stirred to prevent binder agglomeration. Finally, the mixture was placed back into the planetary ball mill and ball-milled for another 8 hours to obtain a spray-granulated slurry with a certain viscosity.

[0048] Spray granulation experiment: Spray drying was performed using an airflow spray granulator with an air pressure of 0.2 MPa, an inlet air temperature of 170℃, and a feed rate of 18 rpm. Finally, the collected agglomerated powder was placed in a vacuum drying oven and kept at that temperature for 90 minutes to remove any adhering moisture.

[0049] Degreasing and calcination treatment of agglomerated powder: The temperature is raised to 100℃ and held for 60 minutes; then, the temperature is raised to 600℃ at a rate of 5℃ / min and held for 4 hours; finally, the powder is heated to 1100℃ and held for 5 hours. The cooling method after calcination is furnace cooling.

[0050] Coating Preparation: The substrate with the adhesive layer prepared was fixed on the worktable, and spraying was performed using an atmospheric plasma spraying system. The plasma working voltage was set to 70V, the working current to 570A, and the powder feeding parameters were synchronized and matched. The powder feeding speed was controlled at 25g / min, and the powder feeding gas flow rate was adjusted to 6L / min to ensure that the powder was uniformly delivered into the core area of ​​the plasma jet. Precise control of the spray gun trajectory was maintained during spraying: the spraying distance was kept at 150mm to improve the particle melting effect; the spray gun movement speed was adjusted to 25mm / s to ensure coating continuity. The final product was a coating with composite pores.

[0051] Figure 5 The porosity changes of the coating prepared in this embodiment and the coating prepared from hollow powder during thermal exposure are shown. Figure 5It can be seen that the sintering behavior of the two coatings is related to their pore structure. Spherical pores dominate in the composite porous coating, accounting for approximately 51% of the total porosity. Furthermore, the structure of these spherical pores does not change significantly throughout the sintering process, with a healing rate of only 2.1%. After 100 hours of heat exposure, spherical pores still account for 62.1% of the total porosity in the coating. This indicates that the spherical pores possess extremely high structural stability during sintering, effectively mitigating the impact of coating sintering on performance.

[0052] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for producing a partially yttria-stabilized zirconia powder having a polymodal pore structure, characterized in that ,Specifically comprising the following steps: Step S1: spray granulation slurry preparation; the nano yttrium stabilized zirconia powder, pore forming agent powder, dispersant solution and deionized water are mixed, the mass ratio of each component is (10-30):(2-10):(1-8):(20-40), the nano yttrium stabilized zirconia powder particle size range is 5-100 nm, the yttrium element content is 3-15%; the pore forming agent is a high molecular polymer composed of C, H and O elements with a burning point of 200-1000 degrees Celsius and a particle size of 0.5-30 microns; use ammonia water to adjust the slurry pH to 7-10 according to the mass ratio of 1:10; Step S2: spray granulation slurry mixing; the spray granulation slurry prepared in step S1 is mixed with zirconia grinding balls, the ball-to-material ratio is (1-3):(3-5); planetary ball milling is used for ball milling, the ball milling speed is 100-200 rpm, the ball milling time is 2-8 h, and a uniformly dispersed suspension slurry is obtained; then 3%-5% of a binder and 0.3%-0.5% of a solid phase mass 0.1-0.3% of n-octanol are added to the suspension slurry, and finally it is put into a planetary ball mill for continuous ball milling for 4-12 h to obtain a spray granulation slurry with viscosity; Step S3: spray drying to prepare agglomerated powder; the spray drying process is: using air flow type spray granulator for spray drying experiment, wherein the air pressure is between 0.1-0.2 MPa, the inlet air temperature is between 100-200℃, and the feeding rate is between 10-30 rpm; finally, the collected agglomerated powder is placed in a vacuum drying oven for 30-120 min; Step S4: defatting and calcining treatment of the agglomerated powder; the defatting and calcining process includes the following steps: first, the temperature is raised to 100℃ and kept for 30-60 minutes; then, the temperature is raised to 500-600℃ at a rate of 5℃ / min and kept for 1-4 hours; finally, the powder is heated to 800-1200℃ and kept for 2-6 hours, and the cooling method after calcination is furnace cooling, obtaining a partially yttrium stabilized zirconia powder with a multi-modal pore structure.

2. The method of claim 1, wherein the partially yttria-stabilized zirconia powder having a polymodal pore structure is characterized by ,The mass ratio of the nano yttrium stabilized zirconia powder, pore forming agent powder, dispersant solution and deionized water in step S1 is (15-25):(3-6):(2-5):(25-35), the nano yttrium stabilized nano zirconia particle size range is 5-40 nm, and the yttrium element content is 3-9%; the pore forming agent is a starch, polystyrene, polymethyl methacrylate powder pore forming agent.

3. The method of claim 1, wherein the partially yttria-stabilized zirconia powder having a polymodal pore structure is characterized by ,In step S2, the spray granulation slurry prepared in step S1 is mixed with zirconia grinding balls, the ball-to-material ratio is (1-3):(3-5); planetary ball milling is used for ball milling, the ball milling speed is 120-180 rpm, the ball milling time is 1-4 h, and a uniformly dispersed suspension slurry is obtained; finally, it is put into a planetary ball mill for continuous ball milling for 6-8 h to obtain a spray granulation slurry with viscosity.

4. The method of claim 1, wherein the partially yttria-stabilized zirconia powder having a polymodal pore structure is characterized by The air pressure in step S3 is between 0.15-0.2 MPa, the air inlet temperature is between 140-180 DEG C, and the feeding rate is between 15-20 rpm; and the powder is kept in the vacuum drying box for 60-90 min.

5. The method of claim 1, wherein the partially yttria-stabilized zirconia powder having a polymodal pore structure is characterized by In step S4, the powder is finally heated to 1000-1100 DEG C and kept for 3-5 hours.

6. A partially yttria-stabilized zirconia powder having a polymodal pore structure, characterized in that The method is used for preparing the partial yttrium stabilized zirconia powder with the polymorphous pore structure according to any one of claims 1-5.

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