Method for preparing TZO powder through solid-phase synthesis

Abstract

The invention relates to the technical field of TZO powder processing, in particular to a method for preparing TZO powder through solid-phase synthesis, which comprises the following preparation steps: carrying out ball milling on ZnO and SnO2 to obtain mixed powder; pre-sintering the mixed powder to obtain activated mixed powder; the activated mixed powder is placed in a vacuum environment to be sintered, after sintering is completed, cooling and screening are conducted, and TZO powder is obtained; the sintering process comprises thirteen sintering stages, the temperature is raised from 25 DEG C to 95-105 DEG C in the first sintering stage, and the temperature raised from the second sintering stage to the fifth sintering stage is 45-55 DEG C, 45-55 DEG C, 195-205 DEG C and 95-105 DEG C respectively; the temperature rising from the seventh sintering stage to the eighth sintering stage is 45-55 DEG C, and the temperature rising from the seventh sintering stage to the eighth sintering stage is 295-305 DEG C; 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 DEG C, 815-880 DEG C, 1065-1180 DEG C and 1400-1500 DEG C. The process is short in time, simple in equipment and low in 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, which is widely used in coated glass, electronics, ceramics, metallurgy and other fields due to its excellent conductivity, high transmittance, high thermal stability and chemical stability. At present, the methods for preparing TZO powder mainly include sol-gel method, coprecipitation method and gas phase method.

[0003] Among them, the sol-gel method is a method of preparing TZO powder by forming a sol through a chemical reaction in a solution, and then undergoing steps such as gelation, drying and sintering. The advantages of this method include low reaction temperature, high product uniformity, easy control of doping amount, high flexibility and low equipment requirements. However, the sol-gel method has disadvantages such as high raw material cost, long time consumption, easy cracking of the product and incomplete sintering.

[0004] The coprecipitation method is to add a precipitant to the solution to make the cations in the solution precipitate together to form the precursor of TZO powder, and then obtain the final product through washing, drying and calcination. The advantages of this method include uniform chemical composition, uniform particle size distribution, simple process, low cost and short preparation cycle. However, the coprecipitation method has the disadvantages of agglomeration, high control precision requirements and complex subsequent processing.

[0005] The gas phase method is a method of generating solid deposits by reacting gaseous or vaporous substances in the gas phase or at the gas-solid interface. When preparing TZO powder, chemical vapor deposition (CVD) or physical vapor deposition (PVD) and other technologies can be used. The advantages of the gas phase method include high product purity, controllable particle size, good dispersibility, and suitability for preparing TZO powders of 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 the problems of complex operation, high equipment requirements, high cost and unstable performance of the prepared TZO powder. Therefore, it is necessary to study a method for preparing TZO powder with simple operation, low equipment requirements, low cost, good uniformity and stable performance. Summary of the invention

[0007] In order to solve the problem that the prior art 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 scheme: A method for preparing TZO powder by solid phase synthesis, comprising the following preparation steps: S1, ball milling ZnO and SnO2 to obtain mixed powder; S2, pre-calcining the mixed powder to obtain an activated mixed powder; S3, placing the activated mixed powder in a vacuum environment for sintering, 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 rises 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 rises from the seventh sintering stage to the eighth sintering stage to 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.

[0009] By adopting the above technical scheme, the prepared TZO powder has high purity, uniform particle size distribution, stable thermal performance, stable chemical properties, and good strength. The method is simple to operate, short time, low equipment requirements, low cost, and can be mass-produced.

[0010] By accurately controlling the temperature during the sintering process, especially by adopting multi-stage heating and constant temperature sintering, the 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 gas phase method, the equipment required for this method is simpler, and no complex solution processing equipment or high vacuum vapor deposition equipment is required. 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 accurately 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.

[0011] The low temperature heating process in the first to fifth sintering stages helps 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 temperature to form a stable TZO phase. The high temperature sintering and constant temperature maintenance in the eleventh to thirteenth sintering stages further promote the densification and grain growth of the powder, resulting in a TZO powder with excellent performance.

[0012] In step S1, the ZnO and SnO2 powders are fully mixed and refined through the ball milling process, which increases the contact area between the particles and is conducive to the uniformity of the subsequent reaction. The pre-sintering treatment in step S2 can remove moisture and volatile impurities in the powder, while activating the surface of the powder particles and improving the reaction activity in the subsequent sintering process.

[0013] Preferably, the heating rates from the first sintering stage to the fifth sintering stage 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 from the seventh sintering stage to the eighth sintering stage 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.

[0014] By adopting the above technical scheme, the heating rate of each sintering stage is precisely controlled to ensure that the TZO powder undergoes appropriate temperature changes and reaction time during the preparation process, so as to obtain high-quality products with uniform chemical composition, reasonable particle size distribution and stable performance. Among them, the first sintering stage helps the powder particles gradually adapt to temperature changes at low temperatures, reduces the thermal stress caused by rapid heating, and is conducive to the subsequent sintering process. The second to fifth sintering stages use a relatively slow heating rate, especially the second, third and fourth stages, which helps the initial bonding between powder particles and the release of internal stress. The heating rate in the fifth stage is appropriately increased by 1.9-2.1℃ / min to accelerate the reaction process before entering the higher temperature area and avoid the adverse effects of too fast heating. The seventh stage adopts an extremely low heating rate to further stabilize the powder structure and reduce thermal stress before entering the high temperature area. The heating rate in the eighth stage increases rapidly in order to quickly pass through the temperature range of 295-305℃ to avoid adverse phase changes or reactions in this range. The tenth stage is to quickly reach a higher sintering temperature and promote the densification of the powder. The twelfth stage helps the powder to continue the sintering process stably at high temperature while avoiding the problems that may arise from heating up too quickly.

[0015] 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.

[0016] 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 is convenient for subsequent sintering. The sintering time of the eighth stage is relatively short, which 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 be caused by staying at high temperature for a long time. 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. Appropriate sintering time can ensure the full bonding between the powder particles, while avoiding the performance degradation caused by excessive grain growth. The thirteenth sintering stage is long. Long-term sintering at high temperature helps the powder particles to fully bond, form a dense microstructure, and improve the stability of the product.

[0017] Preferably, in step S3, the vacuum degree reaches 10 -3 -10 -5 Pa.

[0018] By adopting the above technical solutions, the influence of oxygen and moisture in the air is reduced, the high purity of TZO powder is improved, and at the same time the diffusion and bonding between powder particles promote the sintering process, which helps to form a dense microstructure.

[0019] Preferably, the preheating temperature in step S2 is 600-800° C., and the preheating time is 20-30 min.

[0020] 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.

[0021] Preferably, the average particle size of the mixed powder after ball milling in step S1 is 5-15 microns.

[0022] By adopting the above technical solution, the specific surface area is increased, making the contact between powder particles closer and more frequent, thereby improving the uniformity of mixing. The refined powder particles have higher surface energy and activity, making it easier for atoms and ions to diffuse and react during the sintering process, helping to accelerate the formation of TZO phases and the growth of grains, thereby improving sintering efficiency and product quality.

[0023] Preferably, in step S1, the molar ratio of ZnO to SnO2 is 1:(0.8-1.1).

[0024] 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. Preferably, a grinding aid is added in step S1.

[0025] 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.

[0026] Preferably, the thirteen sintering stages are as follows: The first sintering stage is heated from 25°C to 100°C, and the heating rate of the first sintering stage is: 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 is heated from 150°C to 200°C, and the heating rate of the third sintering stage is 0.56°C / min; 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; The fifth sintering stage is heated from 400°C to 500°C, and the heating rate of the fifth sintering stage is 0.56°C / min; The sixth sintering stage is sintering at 500°C for 120 minutes; The seventh sintering stage is heated from 500°C to 550°C, and the heating rate of the seventh sintering stage is 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 sintering 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; In the thirteenth sintering stage, the sintering temperature is maintained at 1400° C. and the sintering time is 240 min.

[0027] The above technical solution is a better 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.

[0028] In summary, this application has the following beneficial effects: 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.

[0029] 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.

[0030] 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.

[0031] 4. Good uniformity: Through ball milling and pre-sintering treatment, ZnO and SnO2 can be fully mixed and activated, which provides good conditions for the subsequent sintering process and helps to obtain TZO powder with good uniformity.

[0032] 5. Stable performance: This method ensures the crystal structure and phase composition of TZO powder by finely controlling the temperature and time during the sintering process, thereby improving the performance stability of the product. In particular, through a multi-stage sintering process, including multiple heating stages and constant temperature sintering stages, the powder can fully react and crystallize during the formation process, avoiding performance problems caused by temperature fluctuations or insufficient sintering, and ensuring high purity, uniform particle size distribution, stable thermal properties, stable chemical properties and good strength of TZO powder. DETAILED DESCRIPTION Example

[0033] Example 1 A method for preparing TZO powder by solid phase synthesis comprises the following preparation steps: S1. Ball mill 0.5kg ZnO, 0.9kg SnO and 1kg grinding aid (ethanol) to obtain a mixed powder with an average particle size of 5-10 microns. S2, pre-sintering the mixed powder at a temperature of 600° C. for 20 min to obtain an activated mixed powder; S3, sintering the activated mixed powder in a vacuum environment, the sintering temperature ranges from room temperature to 1400° C., and the sintering process includes thirteen sintering stages. After sintering, cooling and screening are performed to obtain TZO powder; The thirteen sintering stages are as follows: 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; 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; 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; 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; 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; The sixth sintering stage is sintering at 475°C for 120 min. 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; 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; The ninth sintering stage is to maintain sintering at 815°C for 30 minutes; 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; The eleventh sintering stage is to maintain sintering at 1065°C for 30 minutes; 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; In the thirteenth sintering stage, the sintering temperature is maintained at 1365° C. and the sintering time is 240 min.

[0034] The difference between Example 2-3 and Example 1 is that the raw material dosage and experimental parameters for preparing TZO powder are different. The specific differences are shown in Table 1: Table 1 Raw material dosage and experimental parameters of TZO powder in Examples 1-3 Example 4 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: 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 is heated from 150°C to 200°C, and the heating rate of the third sintering stage is 0.56°C / min; 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; The fifth sintering stage is heated from 400°C to 500°C, and the heating rate of the fifth sintering stage is 0.56°C / min; The sixth sintering stage is sintering at 500°C for 120 minutes; The seventh sintering stage is heated from 500°C to 550°C, and the heating rate of the seventh sintering stage is 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 sintering 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; In the thirteenth sintering stage, the sintering temperature is maintained at 1400° C. and the sintering time is 240 min.

[0035] Example 5 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.

[0036] Example 6 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.

[0037] Example 7 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.

[0038] Example 8 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.

[0039] Example 9 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.

[0040] Example 10 A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the time of the eleventh stage is 20 minutes.

[0041] Embodiment 11 A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that the time of the thirteenth stage is 200 minutes.

[0042] Comparative Example Comparative Example 1 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.

[0043] Comparative Example 2 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.

[0044] Comparative Example 3 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. from the first sintering stage to the fifth sintering stage, and the heating rate is 1.28° C. / min.

[0045] Comparative Example 4 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.

[0046] Comparative Example 5 A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that: the third sintering stage is heated from 140°C to 335°C, and the heating rate of the second sintering stage is 2°C / min; the fourth sintering stage is heated from 335°C to 380°C, and the heating rate of the third sintering stage is 0.56°C / min.

[0047] Comparative Example 6 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 increased 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 increased from 800°C to 850°C, and the heating rate in the eighth sintering stage is 0.33°C / min.

[0048] Comparative Example 7 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.

[0049] Comparative Example 8 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 constant temperature is maintained for 110 minutes.

[0050] Comparative Example 9 A method for preparing TZO powder by solid phase synthesis. The difference between this embodiment and embodiment 1 is that: the temperature in the twelfth sintering stage is increased from 1065°C to 1300°C, the heating rate in the twelfth sintering stage is 1.75°C / min, and the sintering temperature in the thirteenth sintering stage is maintained at 1300°C, and the sintering time is 240min.

[0051] Comparative Example 10 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.

[0052] Comparative Example 11 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.

[0053] Comparative Example 12 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.

[0054] Detection method / test method Bulk density: Refer to Scott volume meter method.

[0055] Thermal performance test: TZO powders were prepared from Examples 1-11 and Comparative Examples 1-12, 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 a termination temperature of 900°C to calculate the mass loss.

[0056] Chemical stability: 10 g of TZO powder was prepared from Examples 1-11 and Comparative Examples 1-12, and then placed in an environment of 85° C. and 90% humidity for 72 hours. The weight was then measured again and the weight change was calculated.

[0057] Hardness test: Prepare TZO powders from Examples 1-11 and Comparative Examples 1-12, take 10 g of each, place them in a 5 cm*5 cm*2 cm mold, and then press them at a pressure of 200 MPa and a temperature of 30°C to obtain a powder cake. The hardness of the powder cake is then tested using a Vickers hardness tester. The load of the Vickers hardness tester is 100 g, and the loading time is 15 seconds.

[0058] Table 2 Experimental data of Examples 1-11 and Comparative Examples 1-12 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 in this application has good fluidity, thermal stability, chemical stability and hardness.

[0059] Comparing Example 1 with Comparative Examples 3-9, the bulk density in Example 1 is greater than that in Comparative Examples 3-9; in the thermal test experiment, the weight loss of Comparative Example 3-9 is greater than that in Example 1; in the chemical stability test, the weight gain of Comparative Example 3-9 is greater than that in the example; in the hardness test, the hardness of Comparative Example 3-9 is greater than that in Example 1, indicating that the TZO prepared by the heating process in the present application has good fluidity, thermal stability, chemical stability and hardness.

[0060] Comparing Example 1 with 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 Examples 10-11 is greater than that of Example 1; in the chemical stability test, the weight gain of Comparative Examples 10-11 is greater than that of the example; in the hardness test, the hardness of Comparative Examples 10-11 is greater than that of Example 1, indicating that the fluidity, thermal stability, chemical stability and hardness of TZO powder can be improved by increasing the sintering time of the process in the present application.

[0061] By comparing Example 1 with Example 4, the bulk density in Example 4 is greater than that in 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; 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. Comparing Example 1 with Example 5-11, the bulk density in Example 1 is greater than that in Example 5-11; in the thermal test experiment, the weight loss of Example 5-11 is greater than that of Example 1; in the chemical stability test, the weight gain of Example 5-11 is greater than that of the example; in the hardness test, the hardness of Example 5-11 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.

[0062] 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 modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be 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 mixed powder; S2, pre-calcining the mixed powder to obtain an activated mixed powder; S3, placing the activated mixed powder in a vacuum environment for sintering, 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 rises 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 rises from the seventh sintering stage to the eighth sintering stage to 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.

2. The method for preparing TZO powder by solid phase synthesis according to claim 1, characterized in that: The heating rates of the first sintering stage to the fifth sintering stage are 0.8-1°C / min, 0.4-0.45°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 sintering stage to the eighth sintering stage 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; the heating rate of the twelfth sintering stage is 1.5-1.6°C / min.

3. 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.

4. 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.

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

6. The method for preparing TZO powder by solid phase synthesis according to claim 1, characterized in that: In step S1, the molar ratio of ZnO to SnO2 is 1:(0.8-1.1).

7. The method for preparing TZO powder by solid phase synthesis according to claim 1, characterized in that: The average particle size of the mixed powder after ball milling in step S1 is 5-15 microns.

8. 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.

9. 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 is heated from 150°C to 200°C, and the heating rate of the third sintering stage is 0.56°C / min; 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; The fifth sintering stage is heated from 400°C to 500°C, and the heating rate of the fifth sintering stage is 0.56°C / min; The sixth sintering stage is sintering at 500°C for 120 minutes; The seventh sintering stage is heated from 500°C to 550°C, and the heating rate of the seventh sintering stage is 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 sintering 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; In the thirteenth sintering stage, the sintering temperature is maintained at 1400° C. and the sintering time is 240 min.

Images