Large-size AZO rotating target with high density, low resistivity, and minimal white skin and its preparation method

Abstract

This invention belongs to the field of target material technology and discloses a method for preparing large-size AZO rotating targets with high density, low resistivity, and minimal white skin. The method includes: spray granulation of a mixed slurry of zinc oxide and aluminum oxide to obtain a mixed powder; cold isostatic pressing of the mixed powder into a mold to obtain a green body; the cold isostatic pressing is performed in 4-6 stages, with the pressure of each subsequent stage being 30-60 MPa higher than the previous stage; sintering the green body in an inert atmosphere, heating it to 1300-1550℃ at a rate of 0.3℃ / min-2℃ / min and holding it at that temperature for 0.5-1 h, then cooling it to 1200-1350℃ at a rate of 2℃-5℃ / min and holding it at that temperature for 10-20 h to obtain the AZO rotating target. By modifying the cold isostatic pressing method and sintering regime in the existing preparation process, it is possible to obtain rotating targets with a length greater than 500 mm, an outer diameter greater than 150 mm, and a thickness greater than 20 mm. Furthermore, the relative density of these rotating targets can be greater than 99.86%, and their resistivity less than 7%. ‑4 It has a high surface quality (Ωcm), low white skin, uniform color inside and out, and a grain size of less than 15μm.

Description

Technical Field

[0001] This invention belongs to the field of target technology, specifically relating to a method for preparing zinc oxide aluminum targets. Background Technology

[0002] With the application of semiconductor materials in fields such as computers and solar energy, the application areas of transparent conductive oxide thin films with superior optical and electrical properties have expanded from infrared radiation reflectors, energy-saving window glass, low-emissivity film glass, antistatic coatings, and anti-icing and defrosting functional glass to optoelectronic fields such as modern liquid crystal displays, organic light-emitting diodes, flat panel displays, plasma displays, gas-sensitive elements, and transparent electrodes. Currently, the industrially prepared and produced transparent conductive thin films are mainly indium tin oxide (ITO) films, but their raw materials are expensive, resulting in high costs; their visible light transmittance is low at high temperatures; and they are easily reduced in hydrogen ions, affecting the efficiency and lifespan of solar cells. Aluminum-doped zinc oxide (AZO) films are abundant and inexpensive, with resistivity and average visible light transmittance reaching 10⁻⁶. -4 Ωcm and 85%; in addition, compared with ITO film, AZO film is more stable in hydrogen ion atmosphere and is a new type of transparent conductive oxide film.

[0003] CN115849896A discloses a zinc oxide target material, its preparation method, and its application. Zinc oxide powder is molded, then subjected to cold isostatic pressing, degreasing, and sintering to obtain the zinc oxide target material. The molding pressure of the zinc oxide blank is 200-400 MPa; the sintering temperature is 1000℃-1200℃. This invention provides a simple and low-cost method for preparing the zinc oxide target material, but the relative density of the target material can only reach 96%.

[0004] CN117756518A discloses a method for preparing zinc oxide aluminum target material. The method uses spray drying sintering process, static pressing molding, and sintering to prepare zinc oxide aluminum target material. The molding pressure is 200MPa, the sintering temperature is 1450℃, and the holding time is 24h. The density of zinc oxide aluminum target material is as high as 99%.

[0005] Under normal pressure sintering conditions, appropriately increasing the sintering temperature tends to increase the density of the target material. However, for AZO targets, high-temperature sintering presents the problem of Zn volatilization. Zinc oxide itself has the characteristic of slight oxygen loss at 800℃ and slight volatilization at 1200℃. Prolonged high-temperature sintering will result in Al-rich areas on the target surface, forming ZnAl2O4. This component is a dielectric material and does not conduct electricity, which will cause uneven surface composition, performance degradation, and increased processing workload in subsequent processes.

[0006] Furthermore, current methods for preparing zinc oxide aluminum targets (AZO targets) make it difficult to produce qualified large-sized AZO targets. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of this invention is to provide a method for preparing large-size AZO rotating targets with high density, low resistivity and less white skin.

[0008] The large-size AZO rotating target material described in this invention refers to an AZO rotating target material with a length greater than 500mm, an outer diameter greater than 150mm, and a thickness greater than 20mm.

[0009] To achieve the above objectives, the present invention provides the following specific technical solutions.

[0010] A method for preparing a large-size AZO rotating target with high density, low resistivity, and minimal white skin includes:

[0011] The mixture of zinc oxide and aluminum oxide slurry is spray-granulated to obtain a mixed powder.

[0012] After the mixed powder is loaded into the mold, it is subjected to cold isostatic pressing to obtain a green body; the cold isostatic pressing is carried out in 4-6 stages, and during the pressurization process, the pressure of the later stage is 30-60 MPa greater than the pressure of the previous stage;

[0013] The green blank is sintered in an inert atmosphere, heated to 1300℃~1550℃ at a rate of 0.3℃ / min~2℃ / min and held for 0.5-1h, and then cooled to 1200℃~1350℃ at a rate of 2℃~5℃ / min and held for 10-20h to obtain AZO rotating sputtering target.

[0014] In a further preferred embodiment, the mass ratio of zinc oxide to aluminum oxide in the zinc oxide and aluminum oxide slurry is 99~98:1~2.

[0015] In a further preferred embodiment, the zinc oxide and aluminum oxide mixed slurry is obtained by mixing zinc oxide slurry and aluminum oxide slurry.

[0016] Furthermore, a binder is added when mixing zinc oxide slurry and alumina slurry.

[0017] Further, the binder is at least one selected from polyvinyl alcohol, carboxymethyl cellulose, polyacrylamide, polyacrylate, and polyethylene glycol. More preferably, the amount of the binder used is 1-5% of the mass of the zinc oxide and alumina mixture slurry.

[0018] Further, alumina powder, a first dispersant, and water are mixed and slurried to obtain an alumina slurry; zinc oxide powder, a second dispersant, and water are mixed and slurried to obtain a zinc oxide slurry.

[0019] Furthermore, the first dispersant and the second dispersant are independently selected from one or more of polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, and sodium hexadecylbenzenesulfonate.

[0020] Furthermore, the amount of the first dispersant is 1-5% of the mass of the alumina slurry; the amount of the second dispersant is 10-15% of the mass of the zinc oxide slurry.

[0021] In a further preferred embodiment, spray granulation is performed using a spray drying tower, wherein the outlet air temperature of the spray drying tower is 130-200℃ and the atomizer frequency is 40-70Hz.

[0022] In a further preferred embodiment, the loose density of the mixed powder is 1.55-1.7 g / cm³. 3 .

[0023] In a further preferred embodiment, the cold isostatic pressing is performed in five stages: the pressure of the first stage is 30-50 MPa, and the holding time is 3-6 min; the pressure of the second stage is 60-90 MPa, and the holding time is 2-6 min; the pressure of the third stage is 100-130 MPa, and the holding time is 1-3 min; the pressure of the fourth stage is 140-160 MPa, and the holding time is 1-3 min; and the pressure of the fifth stage is 170-200 MPa, and the holding time is 10-15 min.

[0024] In a further preferred embodiment, the inert atmosphere is an argon atmosphere.

[0025] Based on the same inventive concept, this invention provides a large-size rotating AZO target material, wherein the length of the large-size rotating AZO target material is greater than 500 mm, the outer diameter is greater than 150 mm, the thickness is greater than 20 mm, the relative density is greater than 99.86%, and the resistivity is less than 7. -4 Ωcm.

[0026] Further preferably, the grain size of the large-size rotating AZO target is less than 15 μm.

[0027] Compared with the prior art, the above-described one or more technical solutions of the present invention can achieve at least one of the following beneficial effects:

[0028] The method for preparing AZO rotating targets provided by this invention can prepare rotating targets with a length greater than 500 mm, an outer diameter greater than 150 mm, and a thickness greater than 20 mm. The targets have good surface quality, little white skin, uniform internal and external color, and a grain size of less than 15 μm.

[0029] By modifying the cold isostatic pressing method and sintering regime in the existing preparation process, a relative density greater than 99.86% and a resistivity less than 7 can be obtained. -4 The large-size AZO rotating target with an Ωcm diameter can be used on existing production lines without increasing equipment and site costs.

[0030] The preparation method provided by this invention is simple and reliable. Attached Figure Description

[0031] Figure 1 This is a SEM image of a cross section of the AZO rotating target obtained in Example 1. Detailed Implementation

[0032] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0033] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0034] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0035] Example 1

[0036] Step 1: Weigh out zinc oxide powder and aluminum oxide powder according to the mass ratio of zinc oxide to aluminum oxide of 98:2 and set aside.

[0037] Step 2: Add a certain amount of pure water and polyvinylpyrrolidone dispersant to the dispersion tank. Add the alumina powder weighed in Step 1 to the dispersion tank for pre-dispersion. The dispersion time is 30 minutes and the dispersion speed is 180 rpm. The amount of polyvinylpyrrolidone accounts for 5% of the total mass of the material.

[0038] Step 3: The slurry obtained in Step 2 is pumped into a sand mill using a pneumatic diaphragm pump for grinding. The grinding time is 6 hours and the grinding speed is 900 r / min to obtain alumina slurry.

[0039] Step 4: Add a certain amount of pure water and polyvinylpyrrolidone dispersant to the dispersion tank. Add the zinc oxide powder weighed in Step 1 to the dispersion tank for pre-dispersion. The dispersion time is 40 minutes and the dispersion speed is 200 rpm. The amount of polyvinylpyrrolidone accounts for 15% of the total mass of the material.

[0040] Step 5: The slurry obtained in Steps 3 and 4 is pumped into a sand mill and ground for 6 hours at a speed of 800 r / min using a pneumatic diaphragm pump. 1.8% polyvinyl alcohol by mass of the slurry obtained in Steps 3 and 4 is added to obtain a zinc oxide aluminum mixed slurry.

[0041] Step 6: The mixed slurry obtained in Step 5 is fed into a spray drying tower for spray granulation, followed by mixing and sieving to obtain zinc oxide aluminum mixed powder. The outlet air temperature is 130℃, and the atomizer frequency is 70Hz. The loose powder density is 1.7g / cm³. 3 .

[0042] Step 7: The mixed powder obtained in Step 6 is loaded into a rotating target (large size) mold, and then subjected to cold isostatic pressing to obtain a zinc oxide aluminum target blank. The process parameters for cold isostatic pressing are: 30 MPa for 3 min, 60 MPa for 2 min, 90 MPa for 1 min, 120 MPa for 3 min, and 180 MPa for 15 min in the pressurization and depressurization sections.

[0043] Step 8: Sinter the zinc oxide aluminum target blank. In the sintering furnace, argon gas is introduced to purge the air and argon gas is continuously introduced at a rate of 40 L / min. The temperature of the argon gas is maintained to ensure stable heating and cooling during the sintering process. First, the temperature is increased to 1550℃ at a heating rate of 2℃ / min and held for 0.5 h. Then, the temperature is decreased to 1350℃ at a cooling rate of 4℃ / min and held for 15 h to obtain the target material.

[0044] Figure 1 This is a SEM image of a cross section of the AZO rotating target obtained in Example 1.

[0045] Comparative Example 1

[0046] The only difference between Comparative Example 1 and Example 1 is step 8. Specifically:

[0047] Step 8: Sinter the zinc oxide aluminum target blank. In the sintering furnace, argon gas is introduced to purge the air and argon gas is continuously introduced at a rate of 40 L / min. The temperature of the argon gas is maintained to ensure stable heating and cooling during the sintering process. The temperature is increased to 1550℃ at a rate of 2℃ / min and held for 15 hours to obtain the target material.

[0048] Comparative Example 2

[0049] The only difference between Comparative Example 2 and Example 1 is step 7. Specifically:

[0050] Step 7: Perform cold isostatic pressing on the mixed powder obtained in step 6, pressurize to 180 MPa and hold for 15 min.

[0051] Comparative Example 3

[0052] The only difference between Comparative Example 3 and Example 1 is step 7. Specifically:

[0053] Step 7: The mixed powder obtained in Step 6 is subjected to cold isostatic pressing to obtain zinc oxide aluminum target blanks. The process parameters for cold isostatic pressing are: 30 MPa for 3 min, 50 MPa for 2 min, 80 MPa for 1 min, 100 MPa for 3 min, and 200 MPa for 15 min in the pressurization and depressurization sections.

[0054] Comparative Example 4

[0055] The only difference between Comparative Example 4 and Example 1 is that the heating rate in step 8 is 0.2℃ / min.

[0056] Comparative Example 5

[0057] The only difference between Comparative Example 5 and Example 1 is that the heating rate in step 8 is 2.5°C / min.

[0058] Comparative Example 6

[0059] The only difference between Comparative Example 6 and Example 1 is that the cooling rate in step 8 is 1°C / min.

[0060] Comparative Example 7

[0061] The only difference between Comparative Example 7 and Example 1 is that the cooling rate in step 8 is 6°C / min.

[0062] Comparative Example 8

[0063] The only difference between Comparative Example 8 and Example 1 is that in step 8, the temperature is first increased to 1550°C at a heating rate of 2°C / min and held for 1.5 hours, and then decreased to 1350°C at a cooling rate of 0.4°C / min and held for 15 hours.

[0064] Comparative Example 9

[0065] The only difference between Comparative Example 9 and Example 1 is that:

[0066] Step 8 is different. Specifically:

[0067] Step 8: Sinter the zinc oxide aluminum target blank. In the sintering furnace, argon gas is introduced to purge the air and argon gas is continuously introduced at a rate of 40 L / min. The temperature of the argon gas is maintained to ensure stable heating and cooling during the sintering process. The temperature is increased to 1350℃ at a rate of 2℃ / min and held for 15 hours to obtain the target material.

[0068] Example 2

[0069] Step 1: Weigh out zinc oxide powder and aluminum oxide powder according to the mass ratio of zinc oxide to aluminum oxide of 98:2 and set aside.

[0070] Step 2: Add a certain amount of pure water and sodium dodecylbenzenesulfonate dispersant to the dispersion tank. Add the alumina powder weighed in Step 1 to the dispersion tank for pre-dispersion. The dispersion time is 30 min and the dispersion speed is 180 rpm. The amount of sodium dodecylbenzenesulfonate accounts for 3% of the total mass of the material.

[0071] Step 3: The slurry obtained in Step 2 is pumped into a sand mill using a pneumatic diaphragm pump for grinding. The grinding time is 6 hours and the grinding speed is 900 r / min to obtain alumina slurry.

[0072] Step 4: Add a certain amount of pure water and sodium hexadecylbenzenesulfonate dispersant to the dispersion tank. Add the zinc oxide powder weighed in Step 1 to the dispersion tank for pre-dispersion. The dispersion time is 40 minutes and the dispersion speed is 200 rpm. The amount of sodium hexadecylbenzenesulfonate accounts for 12% of the total mass of the material.

[0073] Step 5: The slurry obtained in Steps 3 and 4 is pumped into a sand mill and ground for 6 hours at a speed of 800 r / min using a pneumatic diaphragm pump. 5% polyacrylamide is added based on the mass of the slurry obtained in Steps 3 and 4 to obtain a zinc oxide aluminum mixed slurry.

[0074] Step 6: The mixed slurry obtained in Step 5 is fed into a spray drying tower for spray granulation, followed by mixing and sieving to obtain zinc oxide aluminum mixed powder. The outlet air temperature is 150℃, and the atomizer frequency is 50Hz. The loose bulk density of the mixed powder is 1.7 g / cm³. 3 .

[0075] Step 7: The mixed powder obtained in Step 6 is loaded into a rotating target (large size) mold, and then subjected to cold isostatic pressing to obtain a zinc oxide aluminum target blank. The process parameters for cold isostatic pressing are: holding pressure at 40 MPa for 5 min, 70 MPa for 2 min, 120 MPa for 2 min, 150 MPa for 2 min, and 200 MPa for 10 min in the pressurization and depressurization sections.

[0076] Step 8: Sinter the zinc oxide aluminum target blank. In the sintering furnace, argon gas is introduced to purge the air and argon gas is continuously introduced at a rate of 40 L / min. The temperature of the argon gas is maintained to ensure stable heating and cooling during the sintering process. First, the temperature is increased to 1450℃ at a heating rate of 1℃ / min and held for 1 hour. Then, the temperature is decreased to 1300℃ at a cooling rate of 2℃ / min and held for 20 hours to obtain the target material.

[0077] Example 3

[0078] Step 1: Weigh out zinc oxide powder and aluminum oxide powder according to the mass ratio of zinc oxide to aluminum oxide of 99:1 and set aside.

[0079] Step 2: Add a certain amount of pure water and sodium dodecylbenzenesulfonate dispersant to the dispersion tank. Add the alumina powder weighed in Step 1 to the dispersion tank for pre-dispersion. The dispersion time is 30 min and the dispersion speed is 180 rpm. The amount of polyvinylpyrrolidone accounts for 1% of the total mass of the material.

[0080] Step 3: The slurry obtained in Step 2 is pumped into a sand mill using a pneumatic diaphragm pump for grinding. The grinding time is 6 hours and the grinding speed is 900 r / min to obtain alumina slurry.

[0081] Step 4: Add a certain amount of pure water and sodium cetylbenzene dispersant to the dispersion tank. Add the zinc oxide powder weighed in Step 1 to the dispersion tank for pre-dispersion. The dispersion time is 40 min and the dispersion speed is 200 rpm. The amount of polyvinylpyrrolidone accounts for 10% of the total mass of the material.

[0082] Step 5: The slurry obtained in Steps 3 and 4 is pumped into a sand mill and ground for 6 hours at a speed of 800 r / min. 1% of the mass of the slurry obtained in Steps 3 and 4 is added with carboxymethyl cellulose to obtain a zinc oxide aluminum mixed slurry.

[0083] Step 6: The mixed slurry obtained in Step 5 is fed into a spray drying tower for spray granulation, followed by mixing and sieving to obtain zinc oxide aluminum mixed powder. The outlet air temperature is 200℃, and the atomizer frequency is 60Hz. The loose powder density is 1.65g / cm³. 3 .

[0084] Step 7: The mixed powder obtained in Step 6 is loaded into a rotating target (large size) mold, and then subjected to cold isostatic pressing to obtain a zinc oxide aluminum target blank. The process parameters for cold isostatic pressing are: holding pressure at 50 MPa for 3 min, 90 MPa for 2 min, 120 MPa for 2 min, 150 MPa for 2 min, and 180 MPa for 10 min in the pressurization and depressurization sections.

[0085] Step 8: Sinter the zinc oxide aluminum target blank. In the sintering furnace, argon gas is introduced to purge the air and argon gas is continuously introduced at a rate of 40 L / min. The temperature of the argon gas is maintained to ensure stable heating and cooling during the sintering process. First, the temperature is increased to 1300℃ at a heating rate of 0.5℃ / min and held for 0.5h. Then, the temperature is decreased to 1200℃ at a cooling rate of 5℃ / min and held for 20h to obtain the target material.

[0086] Example 4

[0087] Step 1: Weigh out zinc oxide powder and aluminum oxide powder according to the mass ratio of zinc oxide to aluminum oxide of 99:1 and set aside.

[0088] Step 2: Add a certain amount of pure water and polyvinylpyrrolidone dispersant to the dispersion tank. Add the alumina powder weighed in Step 1 to the dispersion tank for pre-dispersion. The dispersion time is 30 minutes and the dispersion speed is 180 rpm. The amount of polyvinylpyrrolidone accounts for 2% of the total mass of the material.

[0089] Step 3: The slurry obtained in Step 2 is pumped into a sand mill using a pneumatic diaphragm pump for grinding. The grinding time is 6 hours and the grinding speed is 900 r / min to obtain alumina slurry.

[0090] Step 4: Add a certain amount of pure water and polyvinylpyrrolidone dispersant to the dispersion tank. Add the zinc oxide powder weighed in Step 1 to the dispersion tank for pre-dispersion. The dispersion time is 40 minutes and the dispersion speed is 200 rpm. The amount of polyvinylpyrrolidone accounts for 12% of the total mass of the material.

[0091] Step 5: The slurry obtained in Steps 3 and 4 is pumped into a sand mill and ground for 6 hours at a speed of 800 r / min. 3% polyvinyl alcohol is added based on the mass of the slurry obtained in Steps 3 and 4 to obtain a zinc oxide aluminum mixed slurry.

[0092] Step 6: The mixed slurry obtained in Step 5 is fed into a spray drying tower for spray granulation, followed by mixing and sieving to obtain zinc oxide aluminum mixed powder. The outlet air temperature is 180℃, and the atomizer frequency is 40Hz. The loose bulk density of the mixed powder is 1.7 g / cm³. 3 .

[0093] Step 7: The mixed powder obtained in Step 6 is loaded into a rotating target (large size) mold, and then subjected to cold isostatic pressing to obtain a zinc oxide aluminum target blank. The process parameters for cold isostatic pressing are: 50 MPa for 3 min, 90 MPa for 2 min, 130 MPa for 2 min, 170 MPa for 3 min, and 200 MPa for 15 min in the pressurization and depressurization sections.

[0094] Step 8: Sinter the zinc oxide aluminum target blank. In the sintering furnace, argon gas is introduced to purge the air and argon gas is continuously introduced at a rate of 40 L / min. The temperature of the argon gas is maintained to ensure stable heating and cooling during the sintering process. First, the temperature is increased to 1350℃ at a heating rate of 0.3℃ / min and held for 1 hour. Then, the temperature is decreased to 1200℃ at a cooling rate of 3℃ / min and held for 20 hours to obtain the target material.

[0095] The relative density, resistivity, white skin thickness, and grain size of the AZO target were tested using the following methods.

[0096] (1) Relative density: Archimedes' method of displacement.

[0097] (2) Resistivity: Four-probe method.

[0098] (3) Thickness of the white skin layer: measured by vernier calipers.

[0099] (4) Grain size: Determined by measuring the grain size in the SEM image.

[0100] The results are shown in Table 1.

[0101] Table 1

[0102]

[0103] As can be seen from the data in Table 1, the cold isostatic pressing and sintering processes are crucial in obtaining large-sized AZO rotating targets that balance high relative density, low resistivity, and minimal blasting. Low heating or cooling rates result in more blasting on the surface of the rotating target; long high-temperature holding times increase blasting and grain size. The method for preparing large-sized AZO rotating targets provided by this invention produces targets with good surface quality, minimal blasting, uniform internal and external color, grain size less than 15 μm, a relative density greater than 99.86%, and a resistivity less than 7%. -4 Ωcm.

[0104] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a large-size AZO rotating target with high density, low resistivity, and minimal white skin, comprising: The mixture of zinc oxide and aluminum oxide slurry is spray-granulated to obtain a mixed powder. After the mixed powder is loaded into the mold, it is subjected to cold isostatic pressing to obtain a green body; The cold isostatic pressing is performed in five stages. During the pressurization process, the pressure in each subsequent stage is 30-60 MPa higher than that in the previous stage. The pressure in the first stage is 30-50 MPa, and the holding time is 3-6 minutes. The pressure in the second stage is 60-90 MPa, and the holding time is 2-6 minutes. The pressure in the third stage is 100-130 MPa, and the holding time is 1-3 minutes. The pressure in the fourth stage is 140-160 MPa, and the holding time is 1-3 minutes. The pressure in the fifth stage is 170-200 MPa, and the holding time is 10-15 minutes. The green blank is sintered in an inert atmosphere, heated to 1300℃~1550℃ at a rate of 0.3℃ / min~2℃ / min and held for 0.5-1h, and then cooled to 1200℃~1350℃ at a rate of 2℃~5℃ / min and held for 10-20h to obtain AZO rotating target material. The large-size rotating AZO target has a length greater than 500mm, an outer diameter greater than 150mm, and a thickness greater than 20mm.

2. The preparation method according to claim 1, characterized in that, The mass ratio of zinc oxide to aluminum oxide in the zinc oxide and aluminum oxide slurry is 99~98:1~2.

3. The preparation method according to claim 1 or 2, characterized in that, The zinc oxide and aluminum oxide mixed slurry is obtained by mixing zinc oxide slurry and aluminum oxide slurry; Alumina powder, a first dispersant, and water are mixed to form a slurry and then ground to obtain an alumina slurry. Zinc oxide powder, a second dispersant, and water are mixed to form a slurry and then ground to obtain a zinc oxide slurry.

4. The preparation method according to claim 3, characterized in that, When mixing zinc oxide slurry and alumina slurry, a binder is added; the binder is at least one of polyvinyl alcohol, carboxymethyl cellulose, polyacrylamide, polyacrylate, and polyethylene glycol; the amount of the binder is 1 to 5% of the mass of the mixed zinc oxide and alumina slurry.

5. The preparation method according to claim 3, characterized in that, The first dispersant and the second dispersant are independently selected from one or more of polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, and sodium hexadecylbenzenesulfonate; the amount of the first dispersant is 1 to 5% of the mass of the alumina slurry; and the amount of the second dispersant is 10 to 15% of the mass of the zinc oxide slurry.

6. The preparation method according to claim 1, characterized in that, Spray granulation is performed using a spray drying tower, wherein the outlet air temperature of the spray drying tower is 130-200℃ and the atomizer frequency is 40-70Hz.

7. The preparation method according to claim 1, characterized in that, The inert atmosphere is an argon atmosphere.

Images