阅读说明：本技术 一种用于高压避雷器的氧化锌压敏电阻及其制备方法 (Zinc oxide piezoresistor for high-voltage arrester and preparation method thereof ) 是由 龚文 张磊 潘俊乔 于 2020-06-12 设计创作，主要内容包括：本发明公开了一种用于高压避雷器的氧化锌压敏电阻及其制备方法,涉及无铅压电陶瓷技术领域,该方案采用铋、锑、钴、镍、锰、铬、铝、硅、稀土元素进行掺杂,提高其电学性能。本发明使用微波烧结的工艺制备的氧化锌压敏电阻,相比传统的烧结工艺,相同配方下微波烧结的烧结温度更低,烧结时间更短,可降低氧化锌压敏电阻在生产过程中的能源使用,节能环保。(The invention discloses a zinc oxide piezoresistor for a high-voltage arrester and a preparation method thereof, and relates to the technical field of lead-free piezoelectric ceramics. Compared with the traditional sintering process, the microwave sintering process for preparing the zinc oxide piezoresistor has the advantages that the sintering temperature of the microwave sintering process under the same formula is lower, the sintering time is shorter, the energy consumption of the zinc oxide piezoresistor in the production process can be reduced, and the energy is saved and the environment is protected.)

1. A zinc oxide piezoresistor for a high-voltage arrester is characterized in that: comprises ZnO and Bi₂O₃、Sb2O₃、Co₃O₄、NiO、MnO₂、Cr₂O₃、Al(NO₃)₃·9H₂O、SiO₂、In₂O₃And rare earth oxide Sm₂O₃、Y₂O₃、CeO₂、La₂O₃Mixing to form a mixture; in the mixture, the mole fraction of ZnO is 93.5% -97%, Bi₂O₃The mole fraction of the Sb is 0.5-1 percent₂O₃、Co₃O₄、NiO、MnO₂、Cr₂O₃、Al(NO₃)₃·9H₂O、SiO₂The mole fraction of the active component is 1.5-3.35%, and In₂O₃The mole fraction of the rare earth oxide is 0-0.3%, and the mole fraction of the rare earth oxide is 0-0.3%.

2. The method for preparing the zinc oxide varistor for the high-voltage arrester according to claim 1, characterized by comprising the following steps:

(1) mixing the materials and the proportion according to the claim 1 to form a mixture, adding a binder PVA and ultrapure water into the mixture, performing ball milling and mixing by using a ball mill to obtain mixed slurry, drying the slurry at 90 ℃, and granulating to obtain mixed powder; wherein the PVA accounts for 0.003-0.006% of the mass fraction of the powder mixture, the mass ratio of the ultrapure water to the powder is 3:2, the ball milling speed is 400-500 r/min, and the ball milling time is as follows: 0.5-4 h;

(2) pouring the dried powder into a die, pressing the mixed powder into a shape under 7 MPa-10 MPa by using a tablet press to obtain a blank, and drying for 30min at 150 ℃ by using a blast drier;

(3) sintering the molded blank sample in an air atmosphere at 800-1200 ℃ under the frequency of 2.45-24 GHz by using a microwave sintering furnace to obtain a sheet ZnO ceramic;

(4) and printing silver electrode slurry on two surfaces of the chip ZnO ceramic by adopting a screen printing process, drying the paste by using a blast drying oven at 150 ℃, and processing the paste in an air atmosphere at 550-650 ℃ to obtain the chip zinc oxide piezoresistor.

3. The method for preparing the zinc oxide varistor for the high-voltage arrester according to claim 2, characterized in that: in the step (1), Bi is added to the mixture₂O₃、Sb₂O₃、Co₃O₄、NiO、MnO₂、Cr₂O₃、Al(NO₃)₃·9H₂O、SiO₂The total amount added is not more than 5.1mol% of the total amount.

4. The preparation method of the zinc oxide varistor used for the high-voltage arrester according to claim 2,the method is characterized in that: in the step (1), SmO is further added to the mixture₂、Y₂O₃、CeO₂、La₂O₃、In₂O₃Wherein one or more of them are added in a total amount of not more than 0.3% mol of the mixture.

5. The method for preparing the zinc oxide varistor for the high-voltage arrester according to claim 2, characterized in that: in the step (1), PVA is further added into the mixture to serve as a binder auxiliary material, and the total amount of the PVA is 0.003-0.006% of the mass fraction of the mixture.

6. The method for preparing a zinc oxide varistor for a high-voltage arrester according to any of claims 2 to 5, characterized in that: in the steps (3) - (4), sintering the blank obtained in the step (2) in an air atmosphere by using a microwave sintering process at a frequency of 2.45 GHz-24 GHz and at a temperature of 800-1200 ℃, printing silver electrodes on two sides by using a screen printing process, and performing heat treatment at a temperature of 550-650 ℃ in the air atmosphere to obtain the silver-plated copper-based alloy.

Technical Field

The invention belongs to the technical field of electronic ceramic components, and particularly relates to a method for preparing a zinc oxide piezoresistor for a high-voltage arrester by a microwave sintering process.

Background

The ZnO varistor lightning arrester has excellent electrical properties such as excellent nonlinear characteristics, high response speed, strong high-energy circulation capability and the like, is widely applied to power systems and power grid systems, and serves as surge impact resistant protection equipment. With the rapid development of the high-speed railway of the ultrahigh-voltage transmission line box in China, the domestic demand for ZnO varistor lightning arrester devices is higher and higher, and the electrical properties of the ZnO varistor lightning arrester devices are also higher.

The traditional preparation method of the ZnO varistor lightning arrester is to sinter the ZnO varistor lightning arrester at the temperature of over 1000 ℃ by using a box furnace, and has the advantages of higher temperature, long heat preservation time and high energy consumption in the preparation process.

Microwave sintering is a special sintering process which is newly developed, and the process utilizes the heat generated by the loss of a medium in a material under the action of microwaves to heat. In the heating process, the kinetic energy of molecules or ions in the material is increased, the sintering activation energy is reduced, and the material has the characteristics of high mass transfer speed, uniform heating and the like.

Disclosure of Invention

The invention aims to provide a zinc oxide piezoresistor for a high-voltage arrester and a preparation method thereof, so as to solve the problems in the background art.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a zinc oxide varistor for high-voltage lightning arrester comprises ZnO and Bi₂O₃、Sb2O₃、Co₃O₄、NiO、MnO₂、Cr₂O₃、Al(NO₃)₃·9H₂O、SiO₂、In₂O₃And rare earth oxide Sm₂O₃、Y₂O₃、CeO₂、La₂O₃Mixing to form a mixture; the molar fraction of ZnO in the mixture was 93.5%~97%,Bi₂O₃The mole fraction of the Sb is 0.5-1 percent₂O₃、Co₃O₄、NiO、MnO₂、Cr₂O₃、Al(NO₃)₃·9H₂O、SiO₂The mole fraction of the active component is 1.5-3.35%, and In₂O₃The mole fraction of the rare earth oxide is 0-0.3%, and the mole fraction of the rare earth oxide is 0-0.3%.

A preparation method of a zinc oxide piezoresistor for a high-voltage arrester comprises the following steps:

(1) mixing the materials and the proportion according to the claim 1 to form a mixture, adding a binder PVA and ultrapure water into the mixture, performing ball milling and mixing by using a ball mill to obtain mixed slurry, drying the slurry at 90 ℃, and granulating to obtain mixed powder; wherein the PVA accounts for 0.003-0.006% of the mass fraction of the powder mixture, the mass ratio of the ultrapure water to the powder is 3:2, the ball milling speed is 400-500 r/min, and the ball milling time is as follows: 0.5-4 h;

(2) pouring the dried powder into a die, pressing the mixed powder into a shape under 7 MPa-10 MPa by using a tablet press to obtain a blank, and drying for 30min at 150 ℃ by using a blast drier;

(3) sintering the molded blank sample in an air atmosphere at 800-1200 ℃ under the frequency of 2.45-24 GHz by using a microwave sintering furnace to obtain a sheet ZnO ceramic;

(4) and printing silver electrode slurry on two surfaces of the sheet ZnO ceramic by adopting a screen printing process, and drying at 150 ℃ by using an air-blast drying oven. And after drying, treating the chip zinc oxide varistor at 550-650 ℃ in an air atmosphere to obtain the chip zinc oxide varistor.

Further, in the step (1), Bi is added to the mixture₂O₃、Sb₂O₃、Co₃O₄、NiO、MnO₂、Cr₂O₃、Al(NO₃)₃·9H₂O、SiO₂The total amount added is not more than 5.1mol% of the total amount.

Further, in the step (1), SmO is also added to the mixture₂、Y₂O₃、CeO₂、La₂O₃、In₂O₃Wherein one or more of them are added in a total amount of not more than 0.3% mol of the mixture.

Further, in the step (1), PVA is added into the mixture to serve as a binder auxiliary material, and the total amount of the PVA is 0.003-0.006% of the mass fraction of the mixture.

Further, in the steps (3) - (4), sintering the blank obtained in the step (2) at 800-1200 ℃ in an air atmosphere by using a microwave sintering process at a frequency of 2.45-24 GHz, printing silver electrodes on two sides by using a screen printing process, and performing heat treatment at 550-650 ℃ in the air atmosphere to obtain the silver-plated copper-clad aluminum alloy.

Has the advantages that: the invention provides a zinc oxide piezoresistor for a high-voltage arrester and a preparation method thereof, which adopt a microwave sintering process, shorten the sintering time, reduce the sintering temperature, reduce the energy consumption in the preparation process, and control the growth of ZnO crystals in the sintering process under the action of rare earth oxide or indium oxide, so that the obtained product has good electrical performance.

Drawings

Fig. 1 is a flow chart of a preparation method of a zinc oxide varistor for a high-voltage arrester according to the invention.

Detailed Description

The present embodiments are to be considered in all respects as illustrative and not restrictive. The technical features of the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example one

A zinc oxide piezoresistor for high-voltage lightning arrester is prepared from ZnO and Bi₂O₃And Sb2O3, Co3O4, NiO, MnO2, Cr2O3, SiO2 and rare earth oxide Sm2O 3.

(1) And weighing the powder materials according to the molar mass. Wherein, the mol fraction of ZnO is 94.9 percent, the mol fraction of Bi2O3 is 0.8 percent, the mol fractions of Sb2O3, Co3O4, NiO, MnO2, Cr2O3 and SiO2 are 1.1 percent, 0.5 percent, 1 percent, 0.5 percent, 0.4 percent and 0.5 percent respectively,Sm₂O₃is 0.3%.

(2) Adding a binder PVA and ultrapure water into the mixture, then performing ball milling and mixing by using a ball mill to obtain mixed slurry, and drying the obtained slurry at 90 ℃ to obtain mixed powder; wherein PVA is 0.003 percent of the mass fraction of the powder mixture, the mass ratio of ultrapure water to powder is 3:2, the ball milling speed is 500r/min, and the ball milling time is as follows: and (3) carrying out ball milling on the mixture for 30min to obtain slurry, and drying the slurry at 90 ℃.

(3) And pouring the dried powder into a die, pressing the mixed powder into a shape under 7.5MPa by using a tablet press to obtain a blank, and drying for 30min at 150 ℃ by using a blast drier.

(4) And sintering the formed blank in an air atmosphere at 900 ℃ under the frequency of 2.45GHz by using a microwave sintering furnace to obtain the sheet ZnO ceramic.

(5) And printing silver electrode slurry on two surfaces of the sheet ZnO ceramic by adopting a screen printing process, and drying at 150 ℃ by using an air-blast drying oven. And after drying, treating the chip zinc oxide varistor at 650 ℃ in an air atmosphere to obtain the chip zinc oxide varistor.

Example two

A zinc oxide varistor for high-voltage lightning arrester is prepared from ZnO, Bi2O3, Sb2O3, Co3O4, NiO, MnO2, Cr2O3, SiO2 and Al (NO)₃)₃`9H₂O, the preparation method comprises the following steps.

(1) And weighing the powder materials according to the molar mass. Wherein, Bi₂O₃0.8%, Sb2O3, Co3O4, NiO, MnO2, Cr2O3 and SiO2 in a molar ratio of 1.14%, 0.55%, 1.06%, 0.5%, 0.35% and 0.88%, respectively, and Al (NO)₃)₃`₉The mole fraction of H2O was 0.01%, the balance being ZnO.

(2) Adding a binder PVA and ultrapure water into the mixture, then performing ball milling and mixing by using a ball mill to obtain mixed slurry, and drying the obtained slurry at 90 ℃ to obtain mixed powder; wherein PVA is 0.003 percent of the mass fraction of the powder mixture, the mass ratio of ultrapure water to powder is 3:2, the ball milling speed is 500r/min, and the ball milling time is as follows: and (3) carrying out ball milling on the mixture for 30min to obtain slurry, and drying the slurry at 90 ℃.

(3) And pouring the dried powder into a die, pressing the mixed powder into a shape under 7.5MPa by using a tablet press to obtain a blank, and drying for 30min at 150 ℃ by using a blast drier.

(4) And sintering the formed blank in an air atmosphere at 900 ℃ under the frequency of 2.45GHz by using a microwave sintering furnace to obtain the sheet ZnO ceramic.

(5) And printing silver electrode slurry on two surfaces of the sheet ZnO ceramic by adopting a screen printing process, and drying at 150 ℃ by using an air-blast drying oven. And after drying, treating the chip zinc oxide varistor at 650 ℃ in an air atmosphere to obtain the chip zinc oxide varistor.

EXAMPLE III

A zinc oxide piezoresistor for high-voltage lightning arrester is prepared from ZnO and Bi₂O₃And Sb2O3, Co3O4, NiO, MnO2, Cr2O3, SiO2 and In2O 3.

(1) And weighing the powder materials according to the molar mass. Wherein, the mol fraction of ZnO is 94.9 percent, the mol fraction of Bi2O3 is 0.8 percent, the mol fractions of Sb2O3, Co3O4, NiO, MnO2, Cr2O3 and SiO2 are 1.1 percent, 0.5 percent, 1 percent, 0.5 percent, 0.4 percent and 0.5 percent respectively, In₂O₃Is 0.3%.

(2) Adding a binder PVA and ultrapure water into the mixture, then performing ball milling and mixing by using a ball mill to obtain mixed slurry, and drying the obtained slurry at 90 ℃ to obtain mixed powder; wherein PVA is 0.003 percent of the mass fraction of the powder mixture, the mass ratio of the ultrapure water to the powder is 3:2, the ball milling speed is 480r/min, and the ball milling time is as follows: and (3) carrying out ball milling on the mixture for 2h to obtain slurry, and drying the slurry at 90 ℃.

(3) And pouring the dried powder into a die, pressing the mixed powder into a shape under the pressure of 8MPa by using a tablet press to obtain a blank, and drying the blank for 30min at the temperature of 150 ℃ by using a blast dryer.

(4) And sintering the formed blank in an air atmosphere at 950 ℃ under the frequency of 24GHz by using a microwave sintering furnace to obtain the sheet ZnO ceramic.

(5) And printing silver electrode slurry on two surfaces of the sheet ZnO ceramic by adopting a screen printing process, and drying at 150 ℃ by using an air-blast drying oven. And after drying, treating the chip zinc oxide varistor at 650 ℃ in an air atmosphere to obtain the chip zinc oxide varistor.

Example four

A zinc oxide piezoresistor for high-voltage lightning arrester is prepared from ZnO and Bi₂O₃And Sb2O3, Co3O4, NiO, MnO2, Cr2O3, SiO2 and rare earth oxide CeO 2.

(1) And weighing the powder materials according to the molar mass. Wherein, the mole fraction of ZnO is 94.90%, the mole fraction of Bi2O3 is 0.8%, the mole fractions of Sb2O3, Co3O4, NiO, MnO2, Cr2O3 and SiO2 are respectively 1.1%, 0.5%, 1%, 0.5%, 0.4% and 0.5%, and the mole fraction of CeO2 is 0.3%.

(2) Adding a binder PVA and ultrapure water into the mixture, then performing ball milling and mixing by using a ball mill to obtain mixed slurry, and drying the obtained slurry at 90 ℃ to obtain mixed powder; wherein PVA is 0.006 percent of the mass fraction of the powder mixture, the mass ratio of ultrapure water to powder is 3:2, the ball milling speed is 500r/min, and the ball milling time is as follows: and (3) carrying out ball milling on the mixture for 2h to obtain slurry, and drying the slurry at 90 ℃.

(3) And pouring the dried powder into a die, pressing the mixed powder into a shape under 7.5MPa by using a tablet press to obtain a blank, and drying for 30min at 150 ℃ by using a blast drier.

(4) And sintering the formed blank in an air atmosphere at 1000 ℃ under the frequency of 2.45GHz by using a microwave sintering furnace to obtain the sheet ZnO ceramic.

(5) And printing silver electrode slurry on two surfaces of the sheet ZnO ceramic by adopting a screen printing process, and drying at 150 ℃ by using an air-blast drying oven. And after drying, treating the chip zinc oxide varistor at 650 ℃ in an air atmosphere to obtain the chip zinc oxide varistor.

EXAMPLE five

A zinc oxide piezoresistor for high-voltage lightning arrester is prepared from ZnO and Bi₂O₃And Sb2O3, Co3O4, NiO, MnO2, Cr2O3, SiO2 and rare earth oxide CeO 2.

(1) And weighing the powder materials according to the molar mass. Wherein, the mol fraction of ZnO is 94.90%, the mol fraction of Bi2O3 is 0.8%, the mol fractions of Sb2O3, Co3O4, NiO, MnO2, Cr2O3 and SiO2 are respectively 1.1%, 0.5%, 1%, 0.5%, 0.4% and 0.5%, and the mol fraction of Y2O3 is 0.3%.

(2) Adding a binder PVA and ultrapure water into the mixture, then performing ball milling and mixing by using a ball mill to obtain mixed slurry, and drying the obtained slurry at 90 ℃ to obtain mixed powder; wherein PVA is 0.006 percent of the mass fraction of the powder mixture, the mass ratio of ultrapure water to powder is 3:2, the ball milling speed is 500r/min, and the ball milling time is as follows: and (3) carrying out ball milling on the mixture for 2h to obtain slurry, and drying the slurry at 90 ℃.

(3) And pouring the dried powder into a die, pressing the mixed powder into a shape under 7.5MPa by using a tablet press to obtain a blank, and drying for 30min at 150 ℃ by using a blast drier.

(4) And sintering the formed blank in an air atmosphere at 1000 ℃ under the frequency of 2.45GHz by using a microwave sintering furnace to obtain the sheet ZnO ceramic.

(5) And printing silver electrode slurry on two surfaces of the sheet ZnO ceramic by adopting a screen printing process, and drying at 150 ℃ by using an air-blast drying oven. And after drying, treating the chip zinc oxide varistor at 650 ℃ in an air atmosphere to obtain the chip zinc oxide varistor.

EXAMPLE six

A zinc oxide piezoresistor for high-voltage lightning arrester is prepared from ZnO and Bi₂O₃And Sb2O3, Co3O4, NiO, MnO2, Cr2O3, SiO2 and rare earth oxide La2O 3.

(1) And weighing the powder materials according to the molar mass. Wherein, the mol fraction of ZnO is 94.90%, the mol fraction of Bi2O3 is 0.8%, the mol fractions of Sb2O3, Co3O4, NiO, MnO2, Cr2O3 and SiO2 are respectively 1.1%, 0.5%, 1%, 0.5%, 0.4% and 0.5%, and the mol fraction of La2O3 is 0.3%.

(2) Adding a binder PVA and ultrapure water into the mixture, then performing ball milling and mixing by using a ball mill to obtain mixed slurry, and drying the obtained slurry at 90 ℃ to obtain mixed powder; wherein PVA is 0.006 percent of the mass fraction of the powder mixture, the mass ratio of ultrapure water to powder is 3:2, the ball milling speed is 500r/min, and the ball milling time is as follows: and (3) carrying out ball milling on the mixture for 2h to obtain slurry, and drying the slurry at 90 ℃.

(3) And pouring the dried powder into a die, pressing the mixed powder into a shape under 10MPa by using a tablet press to obtain a blank, and drying for 30min at 150 ℃ by using a blast drier.

(4) And sintering the formed blank in an air atmosphere at 1000 ℃ under the frequency of 2.45GHz by using a microwave sintering furnace to obtain the sheet ZnO ceramic.

(5) And printing silver electrode slurry on two surfaces of the sheet ZnO ceramic by adopting a screen printing process, and drying at 150 ℃ by using an air-blast drying oven. And after drying, treating the chip zinc oxide varistor at 650 ℃ in an air atmosphere to obtain the chip zinc oxide varistor.

EXAMPLE seven

A zinc oxide piezoresistor for a high-voltage arrester comprises ZnO, Bi2O3, Sb2O3, Co3O4, NiO, MnO2, Cr2O3, Al (NO3) 3.9H 2O, SiO2, In2O3, rare earth oxides Sm2O3, Y2O3, CeO2 and La2O3 which are mixed; in the mixture, the mole fraction of ZnO is 93.5-97%, the mole fraction of Bi2O3 is 0.5-1%, the mole fraction of Sb2O3, Co3O4, NiO, MnO2, Cr2O3, Al (NO3) 3.9H 2O, the mole fraction of SiO2 is 1.5-3.35%, the mole fraction of In2O3 is 0-0.3%, and the mole fraction of rare earth oxide is 0-0.3%.

A preparation method of a zinc oxide piezoresistor for a high-voltage arrester comprises the following steps:

(1) mixing the materials and the proportion according to claim 1 to form a mixture, adding a binder PVA and ultrapure water into the mixture, performing ball milling and mixing by using a ball mill to obtain mixed slurry, adding PVA as a binder auxiliary material, adding the PVA in an amount of 0.003-0.006% of the mass fraction of the mixture, drying the obtained slurry at 90 ℃, and granulating to obtain mixed powder; wherein the PVA accounts for 0.003-0.006% of the mass fraction of the powder mixture, the mass ratio of the ultrapure water to the powder is 3:2, the ball milling speed is 400-500 r/min, and the ball milling time is as follows: 0.5-4 h;

wherein, Bi2O3, Sb2O3, Co3O4, NiO, MnO2, Cr2O3, Al (NO3) 3.9H 2O and SiO2 are added into the mixture, and the total addition amount is not more than 5.1mol percent of the total amount;

one or more of SmO2, Y2O3, CeO2, La2O3 and In2O3 are also added into the mixture, and the total amount is not more than 0.3 mol percent of the mixture;

(2) pouring the dried powder into a die, pressing the mixed powder into a shape under 7 MPa-10 MPa by using a tablet press to obtain a blank, and drying for 30min at 150 ℃ by using a blast drier;

(3) sintering the molded blank sample in an air atmosphere by using a microwave sintering process at the frequency of 2.45 GHz-24 GHz and at the temperature of 800-1200 ℃, printing silver electrodes on two sides by using a screen printing process, and performing heat treatment at the temperature of 550-650 ℃ in the air atmosphere to obtain a sheet ZnO ceramic;

(4) and printing silver electrode slurry on two surfaces of the sheet ZnO ceramic by adopting a screen printing process, and drying at 150 ℃ by using an air-blast drying oven. And after drying, treating the chip zinc oxide varistor at 550-650 ℃ in an air atmosphere to obtain the chip zinc oxide varistor.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.