A method for preparing TZO powder by solid phase synthesis

Abstract

The present application relates to the technical field of TZO powder processing, and more specifically, to a method for preparing TZO powder by solid phase synthesis, comprising the following preparation steps: ball milling ZnO and SnO2 to obtain a mixed powder; pre-sintering the mixed powder to obtain an activated mixed powder; sintering the activated mixed powder in a vacuum environment, cooling after sintering, and screening to obtain TZO powder; the sintering process comprises thirteen sintering stages, wherein the first sintering stage is heated from 25°C to 95-105°C, the second sintering stage to the third sintering stage, and the fourth sintering stage is heated from 25°C to 95-105°C. The rising temperatures of the five sintering stages are 45-55°C, 45-55°C, 195-205°C and 95-105°C respectively; the rising temperatures of the seventh sintering stage to the eighth sintering stage are 45-55°C and 295-305°C respectively; the sixth sintering stage, the ninth sintering stage, the eleventh sintering stage and the thirteenth sintering stage are all constant temperature sintering stages, and the constant temperature sintering temperatures are 475-520°C, 815-880°C, 1065-1180°C and 1400-1500°C respectively. This process has short time, simple equipment and low cost.

Description

Technical Field

[0001] The present application relates to the technical field of TZO powder processing, and more specifically, to a method for preparing TZO powder by solid-phase synthesis. Background Art

[0002] TZO powder is an important ceramic material, widely used in coated glass, electronics, ceramics, metallurgy, and other fields due to its excellent conductivity, high transmittance, high thermal stability, and chemical stability. Currently, the main methods for preparing TZO powder include sol-gel method, co-precipitation method, and vapor phase method.

[0003] The sol-gel method, which involves forming a sol through a chemical reaction in a solution, followed by gelation, drying, and sintering, produces TZO powder. Advantages of this method include low reaction temperature, high product uniformity, easy control of doping levels, high flexibility, and minimal equipment requirements. However, the sol-gel method has disadvantages such as high raw material costs, a long production process, susceptibility to cracking of the finished product, and incomplete sintering.

[0004] The co-precipitation method involves adding a precipitant to a solution to co-precipitate the cations in the solution, forming a TZO powder precursor. The final product is then washed, dried, and calcined. Advantages of this method include uniform chemical composition, uniform particle size distribution, simple process, low cost, and a short production cycle. However, co-precipitation has disadvantages such as agglomeration, high control precision requirements, and complex subsequent processing.

[0005] The gas phase method is a method in which a gaseous or vaporous substance reacts in the gas phase or at a gas-solid interface to form a solid deposit. Chemical vapor deposition (CVD) or physical vapor deposition (PVD) techniques can be used to prepare TZO powder. The advantages of the gas phase method include high product purity, controllable particle size, good dispersibility, and suitability for preparing TZO powders with complex shapes. However, the gas phase method also has disadvantages such as complex equipment, difficult operation, and high cost.

[0006] The above three methods have problems such as complex operation, high equipment requirements, high cost, and unstable performance of the prepared TZO powder. Therefore, it is necessary to develop a method for preparing TZO powder that is simple to operate, has low equipment requirements, low cost, good uniformity, and stable performance. Summary of the Invention

[0007] In order to solve the problem that the existing technology for preparing TZO powder cannot simultaneously achieve simple operation, low equipment requirements, low cost, good uniformity and stable performance, the present application provides a method for preparing TZO powder by solid phase synthesis.

[0008] In a first aspect, the present application provides a method for preparing TZO powder by solid-phase synthesis, which adopts the following technical solution: A method for preparing TZO powder by solid-phase synthesis, comprising the following preparation steps:

[0009] S1, ball milling ZnO and SnO2 to obtain a mixed powder;

[0010] S2, pre-calcining the mixed powder to obtain an activated mixed powder;

[0011] S3, sintering the activated mixed powder in a vacuum environment, cooling after sintering, and screening to obtain TZO powder;

[0012] The sintering process includes thirteen sintering stages, wherein the temperature is raised from 25°C to 95-105°C in the first sintering stage, the temperature is raised from the second sintering stage to the fifth sintering stage to 45-55°C, 45-55°C, 195-205°C and 95-105°C respectively; the temperature is raised from the seventh sintering stage to the eighth sintering stage to 45-55°C and 295-305°C respectively;

[0013] The sixth sintering stage, the ninth sintering stage, the eleventh sintering stage and the thirteenth sintering stage are all constant temperature sintering stages, and the constant temperature sintering temperatures are 475-520°C, 815-880°C, 1065-1180°C and 1400-1500°C respectively.

[0014] By adopting the above technical solution, the TZO powder prepared has high purity, uniform particle size distribution, stable thermal performance, stable chemical properties, and good strength. The method is simple to operate, short in time, has low equipment requirements, low cost, and can be mass-produced.

[0015] By precisely controlling the temperature during the sintering process, especially by adopting multi-stage heating and constant temperature sintering, problems such as cracking and incomplete sintering of the powder during the sintering process can be effectively avoided, thereby obtaining a TZO powder with more stable performance. Compared with the sol-gel method and the vapor phase method, the equipment required for this method is simpler, and does not require complex solution processing equipment or high-vacuum vapor deposition equipment. At the same time, since the raw materials are only ZnO and SnO2, and the preparation process is simple, no chemical reagents and long-term processing are required, so the cost is greatly reduced. Sintering in a vacuum environment in step S3 can effectively avoid the powder from reacting with oxygen or other gases in the air at high temperatures, thereby ensuring the purity and performance of the product. At the same time, by precisely controlling the temperature of the thirteen sintering stages, the temperature is gradually increased, so that the powder particles gradually fuse during the sintering process to form a dense TZO powder.

[0016] The low-temperature heating process in the first to fifth sintering stages facilitates the initial bonding of powder particles and eliminates internal stress. The sintering process in the sixth to tenth sintering stages allows the powder particles to fully react at high temperatures, forming a stable TZO phase. The high-temperature sintering and constant temperature holding in the eleventh to thirteenth sintering stages further promote powder densification and grain growth, resulting in a TZO powder with excellent performance.

[0017] In step S1, the ball milling process thoroughly mixes and refines the ZnO and SnO2 powders, increasing the contact area between the particles and facilitating uniform subsequent reactions. In step S2, the pre-calcination treatment removes moisture and volatile impurities from the powders while activating the powder particle surface, enhancing reactivity during subsequent sintering.

[0018] Preferably, the heating rates of the first to fifth sintering stages are 0.8-1°C / min, 0.4-0.5°C / min, 0.5-0.6°C / min, 0.5-0.6°C / min, 1.9-2.1°C / min and 0.5-0.6°C / min respectively; the heating rates of the seventh to eighth sintering stages are 0.3-0.35°C / min and 1.9-2.1°C / min respectively; the heating rate of the tenth sintering stage is 2.0-2.1°C / min; and the heating rate of the twelfth sintering stage is 1.5-1.6°C / min.

[0019] By employing this technical solution, precise control of the heating rate during each sintering stage ensures that the TZO powder undergoes appropriate temperature changes and reaction times during the production process, resulting in a high-quality product with uniform chemical composition, optimal particle size distribution, and stable performance. The first sintering stage helps the powder particles gradually acclimate to the temperature change at a low temperature, reducing thermal stresses caused by rapid heating, and facilitating subsequent sintering. Relatively slow heating rates are used in the second through fifth sintering stages, particularly in the second, third, and fourth stages, to facilitate initial bonding between powder particles and release internal stresses. The heating rate is increased by 1.9-2.1°C / min in the fifth stage to accelerate the reaction process before entering the higher temperature range and avoid the adverse effects of excessive heating. The seventh stage uses an extremely slow heating rate to further stabilize the powder structure and reduce thermal stress before entering the high-temperature range. The eighth stage rapidly increases the heating rate to quickly pass through the 295-305°C temperature range to avoid adverse phase changes or reactions within this range. The tenth stage is designed to quickly reach a higher sintering temperature and promote powder densification. The twelfth stage helps the powder to continue the sintering process stably at high temperature while avoiding the problems that may arise from too rapid a temperature increase.

[0020] Preferably, the sintering times of the sixth sintering stage, the eighth sintering stage, the ninth sintering stage and the thirteenth sintering stage are 110-130 min, 25-35 min, 25-35 min and 220-260 min, respectively.

[0021] The sixth sintering stage helps the powder particles to fully react at a lower temperature to form a stable TZO phase. The bonding between the powder particles is gradually strengthened, and the internal stress is released, which facilitates subsequent sintering. The sintering time of the eighth stage is relatively short, and is mainly used for the rapid adaptation and initial densification of the powder at high temperature. The shorter sintering time helps to reduce unnecessary energy consumption and avoid abnormal grain growth or phase change that may result from prolonged stay at high temperature. The sintering time of the ninth stage is also relatively short, which promotes the further formation of the TZO phase and the growth of grains. The appropriate sintering time can ensure sufficient bonding between the powder particles, while avoiding performance degradation caused by excessive grain growth. The thirteenth sintering stage is long. Sintering for a long time at high temperature helps to completely bond the powder particles, form a dense microstructure, and improve the stability of the product.

[0022] Preferably, in step S3, the vacuum degree reaches 10 -3 -10 -5 Pa.

[0023] By adopting the above technical solutions, the influence of oxygen and moisture in the air is reduced, the purity of TZO powder is improved, and at the same time, the diffusion and bonding between powder particles are promoted, the sintering process is promoted, and a dense microstructure is formed.

[0024] Preferably, the temperature of the preheating treatment in step S2 is 600-800° C., and the preheating time is 20-30 minutes.

[0025] By adopting the above technical solution, moisture and volatile impurities in the mixed powder can be effectively removed, while the contact and initial bonding between the powder particles are promoted, which helps to form a denser microstructure in the subsequent sintering process.

[0026] Preferably, the average particle size of the mixed powder after ball milling in step S1 is 5-15 microns.

[0027] By adopting this technical solution, the specific surface area is increased, resulting in closer and more frequent contact between powder particles, thereby improving mixing uniformity. Furthermore, the refined powder particles have higher surface energy and activity, facilitating the diffusion and reaction between atoms and ions during the sintering process. This helps accelerate the formation of the TZO phase and grain growth, thereby improving sintering efficiency and product quality.

[0028] Preferably, in step S1, the molar ratio of ZnO to SnO2 is 1:(0.8-1.1).

[0029] By adopting the above technical solution, within this range, the activity and reaction rate of the reactants are relatively stable, which is conducive to controlling the morphology, size and distribution of the products and helping to improve the stability and repeatability of the process.

[0030] Preferably, a grinding aid is added in step S1.

[0031] The adoption of the above technical solution is conducive to promoting the grinding of ZnO and SnO2, improving the grinding efficiency and shortening the grinding process.

[0032] Preferably, the thirteen sintering stages are as follows:

[0033] The first sintering stage was heated from 25°C to 100°C, and the heating rate of the first sintering stage was 0.83°C / min;

[0034] The second sintering stage was heated from 100 °C to 150 °C, and the heating rate of the second sintering stage was 0.42 °C / min;

[0035] The third sintering stage is heated from 150°C to 200°C, and the heating rate of the third sintering stage is 0.56°C / min;

[0036] The fourth sintering stage is heated from 200°C to 400°C, and the heating rate of the fourth sintering stage is 2°C / min;

[0037] The fifth sintering stage is to heat the material from 400°C to 500°C, with a heating rate of 0.56°C / min.

[0038] The sixth sintering stage is to maintain sintering at 500°C for 120 minutes;

[0039] The seventh sintering stage is to heat the sample from 500°C to 550°C, with a heating rate of 0.33°C / min.

[0040] The eighth sintering stage is heated from 550°C to 850°C, and the heating rate of the eighth sintering stage is 2°C / min;

[0041] The ninth sintering stage is to maintain sintering at 850°C for 30 minutes;

[0042] The tenth sintering stage is heated from 850°C to 1100°C, and the heating rate of the tenth sintering stage is 2.08°C / min;

[0043] The eleventh sintering stage is maintained at 1100°C for 30 minutes;

[0044] The twelfth sintering stage is heated from 1100°C to 1400°C, and the heating rate of the twelfth sintering stage is 1.75°C / min;

[0045] The thirteenth sintering stage is carried out at a temperature of 1400° C. and a sintering time of 240 min.

[0046] The above technical solution is the preferred range in this application. Within this range, TZO powder with high purity, uniform particle size distribution, stable thermal performance, stable chemical properties and better strength can be obtained.

[0047] In summary, this application has the following beneficial effects:

[0048] 1. Easy operation: This method has clear steps and is easy to implement. It does not require complicated operating skills or difficult equipment operation, which reduces the technical threshold in the production process.

[0049] 2. Low equipment requirements: Due to the use of solid-phase synthesis, this method has relatively low equipment requirements and does not require special equipment or complex production lines, which is conducive to reducing production costs.

[0050] 3. Low cost: By optimizing the sintering stage and temperature control, this method can reduce energy consumption and material loss while ensuring product quality, thereby effectively controlling production costs.

[0051] 4. Good uniformity: Through ball milling and pre-sintering treatment, ZnO and SnO2 can be fully mixed and activated, providing good conditions for the subsequent sintering process and helping to obtain TZO powder with good uniformity.

[0052] 5. Stable Performance: This method ensures the crystal structure and phase composition of the TZO powder by carefully controlling the temperature and time during the sintering process, thereby improving the product's performance stability. In particular, the multi-stage sintering process, including multiple heating stages and a constant temperature sintering stage, allows the powder to fully react and crystallize during the formation process, avoiding performance issues caused by temperature fluctuations or inadequate sintering. This ensures the TZO powder has high purity, uniform particle size distribution, stable thermal and chemical properties, and excellent strength. DETAILED DESCRIPTION

[0053] Example

[0054] Example 1

[0055] A method for preparing TZO powder by solid phase synthesis comprises the following preparation steps:

[0056] S1, ZnO0.5kg and SnO20.9kg3, and 1kg of grinding aid (ethanol) are ball-milled to obtain a mixed powder with an average particle size of 5-10 microns;

[0057] S2, pre-sintering the mixed powder at a temperature of 600° C. for 20 min to obtain an activated mixed powder;

[0058] S3, sintering the activated mixed powder in a vacuum environment at a sintering temperature ranging from room temperature to 1400° C. The sintering process includes thirteen sintering stages. After sintering, cooling, screening, and obtaining TZO powder;

[0059] The thirteen sintering stages are as follows:

[0060] The first sintering stage was heated from 25°C to 95°C, and the heating rate of the first sintering stage was 0.83°C / min;

[0061] The second sintering stage was heated from 95°C to 140°C, and the heating rate of the second sintering stage was 0.42°C / min;

[0062] The third sintering stage was heated from 140°C to 185°C, and the heating rate of the third sintering stage was 0.56°C / min;

[0063] The fourth sintering stage is heated from 185°C to 380°C, and the heating rate of the fourth sintering stage is 2°C / min;

[0064] The fifth sintering stage is heated from 380°C to 475°C, and the heating rate of the fifth sintering stage is 0.56°C / min;

[0065] The sixth sintering stage is to maintain sintering at 475°C for 120 minutes;

[0066] The seventh sintering stage is heated from 475°C to 550°C, and the heating rate of the seventh sintering stage is 0.33°C / min;

[0067] The eighth sintering stage is heated from 520°C to 815°C, and the heating rate of the eighth sintering stage is 2°C / min;

[0068] The ninth sintering stage is to maintain sintering at 815°C for 30 minutes;

[0069] The tenth sintering stage is heated from 815°C to 1065°C, and the heating rate of the tenth sintering stage is 2.08°C / min;

[0070] The eleventh sintering stage is maintained at 1065℃ for 30min.

[0071] The twelfth sintering stage is heated from 1065°C to 1400°C, and the heating rate of the twelfth sintering stage is 1.75°C / min;

[0072] The thirteenth sintering stage is carried out at 1365° C. for 240 min.

[0073] The difference between Example 2-3 and Example 1 is that the raw material amounts and experimental parameters for preparing TZO powder are different. The specific differences are shown in Table 1:

[0074] Table 1 Raw material dosage and experimental parameters of TZO powder in Examples 1-3

[0075]

[0076]

[0077] Example 4

[0078] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the thirteen sintering stages are as follows:

[0079] The first sintering stage was heated from 25°C to 100°C, and the heating rate of the first sintering stage was 0.83°C / min;

[0080] The second sintering stage was heated from 100°C to 150°C, and the heating rate of the second sintering stage was 0.42°C / min;

[0081] The third sintering stage was heated from 150°C to 200°C, and the heating rate of the third sintering stage was 0.56°C / min;

[0082] The fourth sintering stage is to heat the material from 200°C to 400°C, and the heating rate of the fourth sintering stage is 2°C / min;

[0083] The fifth sintering stage is to heat the material from 400°C to 500°C, with a heating rate of 0.56°C / min.

[0084] The sixth sintering stage is to maintain sintering at 500°C for 120 minutes;

[0085] The seventh sintering stage is to heat the sample from 500°C to 550°C, with a heating rate of 0.33°C / min.

[0086] The eighth sintering stage is heated from 550°C to 850°C, and the heating rate of the eighth sintering stage is 2°C / min;

[0087] The ninth sintering stage is to maintain sintering at 850°C for 30 minutes;

[0088] The tenth sintering stage is heated from 850°C to 1100°C, and the heating rate of the tenth sintering stage is 2.08°C / min;

[0089] The eleventh sintering stage is maintained at 1100°C for 30 minutes;

[0090] The twelfth sintering stage is heated from 1100°C to 1400°C, and the heating rate of the twelfth sintering stage is 1.75°C / min;

[0091] The thirteenth sintering stage is carried out at a temperature of 1400° C. and a sintering time of 240 min.

[0092] Example 5

[0093] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the heating rate in the first stage is 1.5°C / min.

[0094] Example 6

[0095] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the heating rate in the fourth stage is 1°C / min.

[0096] Example 7

[0097] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the heating rate in the eighth stage is 1.5°C / min.

[0098] Example 8

[0099] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the time of the fifth stage is 150 minutes.

[0100] Example 9

[0101] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the time of the eighth stage is 20 minutes.

[0102] Example 10

[0103] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the duration of the eleventh stage is 20 minutes.

[0104] Example 11

[0105] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the duration of the thirteenth stage is 200 minutes.

[0106] Comparative Example

[0107] Comparative Example 1

[0108] A method for preparing TZO powder by solid phase synthesis. The difference between this comparative example and Example 1 is that step S2 is omitted.

[0109] Comparative Example 2

[0110] A method for preparing TZO powder by solid phase synthesis. The difference between this comparative example and Example 1 is that: in step S3, sintering is performed under normal pressure of 101.325 kPa.

[0111] Comparative Example 3

[0112] A method for preparing TZO powder by solid phase synthesis. The difference between this comparative example and Example 1 is that the temperature is increased from 25°C to 475°C in the first sintering stage to the fifth sintering stage at a heating rate of 1.28°C / min.

[0113] Comparative Example 4

[0114] A method for preparing TZO powder by solid phase synthesis. The difference between this comparative example and Example 1 is that the temperature is increased from 475° C. to 815° C. from the seventh sintering stage to the eighth sintering stage, and the heating rate is 1.1° C. / min.

[0115] Comparative Example 5

[0116] A method for preparing TZO powder by solid-phase synthesis. The difference between this embodiment and Example 1 is that: the temperature in the third sintering stage is raised from 140°C to 335°C, and the heating rate in the second sintering stage is 2°C / min; the temperature in the fourth sintering stage is raised from 335°C to 380°C, and the heating rate in the third sintering stage is 0.56°C / min.

[0117] Comparative Example 6

[0118] A method for preparing TZO powder by solid-phase synthesis. The difference between this embodiment and embodiment 1 is that: the temperature in the seventh sintering stage is raised from 500°C to 800°C, and the heating rate in the seventh sintering stage is 2°C / min; the temperature in the eighth sintering stage is raised from 800°C to 850°C, and the heating rate in the eighth sintering stage is 0.33°C / min.

[0119] Comparative Example 7

[0120] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the heating temperature of the fourth stage is 210°C, and the heating temperature of the fifth stage is 80°C.

[0121] Comparative Example 8

[0122] A method for preparing TZO powder by solid-phase synthesis. The difference between this embodiment and embodiment 1 is that: in the sixth sintering stage, the temperature is increased from 475°C to 520°C at 0.3°C / min, and in the seventh stage, the temperature is maintained at a constant temperature for 110 minutes.

[0123] Comparative Example 9

[0124] A method for preparing TZO powder by solid-phase synthesis. The difference between this embodiment and embodiment 1 is that: in the twelfth sintering stage, the temperature is raised from 1065°C to 1300°C, the heating rate of the twelfth sintering stage is 1.75°C / min, and the thirteenth sintering stage is maintained at 1300°C for 240 minutes.

[0125] Comparative Example 10

[0126] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the sixth sintering stage is omitted.

[0127] Comparative Example 11

[0128] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the ninth sintering stage is omitted.

[0129] Comparative Example 12

[0130] A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the eleventh sintering stage is omitted.

[0131] Detection method / test method

[0132] Bulk density: refer to Scott volumetric method.

[0133] Thermal performance test: TZO powders prepared in Examples 1-11 and Comparative Examples 1-12 were taken, 10 mg of each was placed in a crucible, and then placed in a thermogravimetric analyzer with a heating rate of 10°C / min and an end temperature of 900°C to calculate the mass loss.

[0134] Chemical stability: 10 g of each of the TZO powders prepared in Examples 1-11 and Comparative Examples 1-12 was taken and placed in an environment of 85° C. and 90% humidity for 72 h. The weight was then measured again and the weight change was calculated.

[0135] Hardness test: 10 g of TZO powder was prepared from Examples 1-11 and Comparative Examples 1-12, and placed in a 5 cm * 5 cm * 2 cm grinding tool. The powder was then pressed at a pressure of 200 MPa and a temperature of 30°C to obtain a powder cake. The hardness of the powder cake was then tested using a Vickers hardness tester with a load of 100 g and a loading time of 15 seconds.

[0136] Table 2 Experimental data of Examples 1-11 and Comparative Examples 1-12

[0137]

[0138]

[0139] Comparing Example 1 with Comparative Examples 1-2, the bulk density in Example 1 is greater than that in Comparative Examples 1-2; in the thermal test experiment, the weight loss of Comparative Examples 1-2 is greater than that of Example 1; in the chemical stability test, the weight gain of Comparative Examples 1-2 is greater than that of the example; in the hardness test, the hardness of Comparative Examples 1-2 is greater than that of Example 1, indicating that the TZO prepared by the process of this application has good fluidity, thermal stability, chemical stability and hardness.

[0140] Comparing Example 1 with Comparative Examples 3-9, the bulk density in Example 1 is greater than that in Comparative Example 3-9; the weight loss of Comparative Example 3-9 in the thermal test experiment is greater than that in Example 1; the weight gain of Comparative Example 3-9 in the chemical stability test is greater than that in the example; and the hardness of Comparative Example 3-9 in the hardness test is greater than that in Example 1, indicating that the TZO prepared by the heating process of the present application has good fluidity, thermal stability, chemical stability and hardness.

[0141] Comparing Example 1 and Comparative Examples 10-11, the bulk density in Example 1 is greater than that in Comparative Examples 10-11; in the thermal test experiment, the weight loss of Comparative Example 10-11 is greater than that of Example 1; in the chemical stability test, the weight gain of Comparative Example 10-11 is greater than that of the example; in the hardness test, the hardness of Comparative Example 10-11 is greater than that of Example 1, indicating that the process of this application can improve the fluidity, thermal stability, chemical stability and hardness of TZO powder by sintering for a long time.

[0142] Comparing Example 1 with Example 4, the bulk density of Example 4 is greater than that of Example 1; the weight loss of Example 4 in the thermal test experiment is less than that of Example 1; the weight gain of Example 4 in the chemical stability test is less than that of Example 1; and the hardness of Example 4 in the hardness test is greater than that of Example 1. The sintering parameters of Example 4 can improve the fluidity, thermal stability, chemical stability and hardness of TZO powder.

[0143] Comparing Example 1 and Example 5-11, the bulk density in Example 1 is greater than that in Example 5-11; the weight loss of Example 5-11 in the thermal test experiment is greater than that of Example 1; the weight gain of Example 5-11 in the chemical stability test is greater than that of the example; and the hardness of Example 5-11 in the hardness test is greater than that of Example 1, indicating that the sintering parameters of Example 1 can improve the fluidity, thermal stability, chemical stability and hardness of TZO powder.

[0144] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing TZO powder by solid phase synthesis, characterized in that: The method comprises the following preparation steps: S1, ball milling ZnO and SnO2 to obtain a mixed powder; S2, pre-calcining the mixed powder to obtain an activated mixed powder; S3, sintering the activated mixed powder in a vacuum environment, cooling after sintering, and screening to obtain TZO powder; The sintering process includes thirteen sintering stages, wherein the temperature is raised from 25°C to 95-105°C in the first sintering stage, the temperature is raised to 45-55°C, 45-55°C, 195-205°C and 95-105°C in the second to fifth sintering stages respectively; the temperature is raised to 45-55°C and 295-305°C in the seventh to eighth sintering stages respectively; The sixth sintering stage, the ninth sintering stage, the eleventh sintering stage and the thirteenth sintering stage are all constant temperature sintering stages, and the constant temperature sintering temperatures are 475-520° C., 815-880° C., 1065-1180° C. and 1400-1500° C. respectively; The heating rates of the first to fifth sintering stages are 0.8-1°C / min, 0.4-0.45°C / min, 0.5-0.6°C / min, 1.9-2.1°C / min, and 0.5-0.6°C / min, respectively; the heating rates of the seventh to eighth sintering stages are 0.3-0.35°C / min and 1.9-2.1°C / min, respectively; the heating rate of the tenth sintering stage is 2.0-2.1°C / min; and the heating rate of the twelfth sintering stage is 1.75 / min; In step S1, the molar ratio of ZnO to SnO2 is 1:(0.8-1.1); The average particle size of the mixed powder after ball milling in step S1 is 5-15 microns.

2. The method for preparing TZO powder by solid phase synthesis according to claim 1, characterized in that: The sintering times of the sixth sintering stage, the eighth sintering stage, the eleventh sintering stage and the thirteenth sintering stage are 110-130 min, 25-35 min, 25-35 min and 220-260 min respectively.

3. The method for preparing TZO powder by solid phase synthesis according to claim 1, characterized in that: In step S3, the vacuum degree reaches 10 -3 -10 -5 Pa.

4. The method for preparing TZO powder by solid phase synthesis according to claim 1, characterized in that: In step S2, the temperature of the pre-firing treatment is 600-800° C., and the pre-firing time is 20-30 minutes.

5. The method for preparing TZO powder by solid phase synthesis according to claim 1, characterized in that: In step S1 , a grinding aid is added.

6. The method for preparing TZO powder by solid phase synthesis according to claim 1, characterized in that: The thirteen sintering stages are as follows: The first sintering stage was heated from 25°C to 100°C, and the heating rate of the first sintering stage was 0.83°C / min; The second sintering stage was heated from 100°C to 150°C, and the heating rate of the second sintering stage was 0.42°C / min; The third sintering stage was heated from 150°C to 200°C, and the heating rate of the third sintering stage was 0.56°C / min; The fourth sintering stage is to heat the material from 200°C to 400°C, and the heating rate of the fourth sintering stage is 2°C / min; The fifth sintering stage is to heat the material from 400°C to 500°C, with a heating rate of 0.56°C / min. The sixth sintering stage is to maintain sintering at 500°C for 120 minutes; The seventh sintering stage is to heat the sample from 500°C to 550°C, with a heating rate of 0.33°C / min. The eighth sintering stage is heated from 550°C to 850°C, and the heating rate of the eighth sintering stage is 2°C / min; The ninth sintering stage is to maintain sintering at 850°C for 30 minutes; The tenth sintering stage is heated from 850°C to 1100°C, and the heating rate of the tenth sintering stage is 2.08°C / min; The eleventh sintering stage is maintained at 1100°C for 30 minutes; The twelfth sintering stage is heated from 1100°C to 1400°C, and the heating rate of the twelfth sintering stage is 1.75°C / min; The thirteenth sintering stage is carried out at a temperature of 1400° C. and a sintering time of 240 min.

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