15 results about "Varistor ceramics" patented technology

This invention discloses a high-voltage-gradient tin oxide varistor ceramic with adjustable nonlinear coefficients, its preparation method, and its applications, belonging to the field of functional ceramics and their preparation technology. This invention solves the problems of low voltage gradient, difficult-to-control nonlinear coefficients, and limited application in surge protection devices of existing SnO2-based ceramic materials. This invention employs multiple metal oxide composite doping and solid-state sintering to control the varistor performance of SnO2 ceramics through both doping and sintering processes.

The invention belongs to the field of electrical materials and preparation, and particularly discloses a wide-temperature-range low-temperature sintered medium-voltage zinc oxide voltage-sensitive ceramic material and a preparation method thereof. The voltage-sensitive ceramic material is composed of ZnO, Bi2O3, Sb2O3, CoO, MnO2, NiO, Cr2O3, Al2O3 and CaO according to the molar ratio of the ZnO to the Bi2O3 to the Sb2O3 to the CoO to the MnO2 to the NiO to the Cr2O3 to the Al2O3 to the CaO of (97.000 to 98.500) to (0.050 to 0.500) to (0.0125 to 0.0500) to (0.200 to 1.600) to (0.010 to 0.300) to (0.100 to 0.800) to (0.010 to 0.050) to (0.025 to 0.100) to (0.010 to 0.200), the total molar amount of all the components is 100 percent, and the molar ratio of Bi to Sb is (4 to 8) to 1. The preparation method comprises the following steps: preparing a main material ZnO and an additive metal element salt, and carrying out high-energy ball milling to obtain slurry; and calcining the slurry, controlling the average particle size of the obtained composite powder to be less than 0.3 mu m, granulating the composite powder, removing plastic, and sintering to finally obtain the product with the voltage gradient E1mA of 200-230 V / mm. The zinc oxide voltage-sensitive ceramic material is good in performance, the energy consumption in the preparation process is reduced, the influence of sintering temperature fluctuation on the performance of the zinc oxide voltage-sensitive ceramic material is reduced, the consistency of the product performance is ensured, and a thought is expected to be provided for industrial low-carbon production.

The application discloses a ZnO pressure-sensitive ceramic and a simple low-temperature sintering method. The composition of the ZnO pressure-sensitive ceramic is [100-(a+b+c+d+e)] mol% ZnO+amol% Bi2O3+bmol% Co3O4+cmol% Mn2O3+dmol% Cr2O3+emol% SnO2, wherein 2.1<=a+b+c+d+e<=7.5. The ceramic is sintered at a sintering temperature of 800-1000 DEG C, and the voltage gradient E of the ZnO pressure-sensitive ceramic is 1529-2362 V / mm, the nonlinear coefficient a is 63-86, the leakage current density I is 0.2-0.7 mu A / cm b , and the performance is better than that of the commercially available ZnO pressure-sensitive ceramic at the present stage, and the performance requirement of the pressure-sensitive ceramic in actual production can be met. L 2 ​​

This invention discloses a zinc oxide ceramic with tunable nonlinear coefficient, its preparation method, and its applications, belonging to the field of functional ceramics and their preparation technology. This invention solves the problem that existing ZnO-based varistor ceramics cannot achieve tunable nonlinear coefficients. This invention uses AlN as an additive to dope and modify ZnO, utilizing the significant difference in conductivity between AlN and ZnO to construct a Schottky barrier within the ZnO grains, inducing the varistor properties of the ZnO ceramic; and AlN and ZnO have the same crystal structure, Al... 3+ Ions can easily enter the ZnO lattice, achieving the purpose of improving nonlinear characteristics through doping. This allows AlN to simultaneously act as a varistor and a doping modifier for ZnO, resulting in doped zinc oxide ceramics that possess both a single-phase cubic zinc sphalerite-type zinc oxide structure and varistor properties. By changing the doping content of AlN, the nonlinear coefficient and varistor potential gradient can be controlled, thus broadening the application range of zinc oxide ceramics.

The application discloses a three-layer structure pressure-sensitive ceramic containing only a single double-Schottky grain boundary barrier and a sol-gel preparation method and application thereof, and belongs to the technical field of pressure-sensitive materials. A solid-phase sintering method is adopted, ZnO is used as raw material, oxide doped ZnO ceramic green bodies are obtained by doping oxide and pressing, a sol-gel solution containing Bi elements is coated in the middle of the ZnO ceramic green bodies doped with metal oxide, and ZnO green body-rich Bi layer-ZnO green body three-layer structure bodies are obtained by pressing. After sintering, the three-layer structure pressure-sensitive ceramic containing only a single double-Schottky grain boundary barrier with simple structure is obtained, which comprises two ZnO ceramic layers and a middle Bi-rich layer. Based on the structure, the structure, performance and conductive mechanism of the single double-Schottky grain boundary barrier in the ZnO pressure-sensitive ceramic have obvious advantages, the single ZnO grain-grain boundary-ZnO grain structure formed in the complex structure of the conventional ZnO pressure-sensitive ceramic can be simulated, and this provides strong evidence for exploring the internal characteristics of the polycrystal.

The invention belongs to the technical field of voltage-sensitive ceramic material preparation, and particularly relates to multi-element doped ZnO voltage-sensitive ceramic as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing a gallium source, a nickel source, a zirconium source, aluminum nitrate and a solvent, and adjusting the pH value to 7-8 to obtain a mixed solution; the gallium source comprises gallium nitrate and / or gallium acetate; the nickel source comprises nickel nitrate and / or nickel acetate; the zirconium source comprises zirconium nitrate and / or zirconium acetate; the molar ratio of the gallium source to the nickel source to the zirconium source is (0.2-1.5): (0.5-1.8): (0.2-1); and (2) mixing the mixed solution with the remaining raw materials to obtain a mixture, granulating and forming to obtain a green body, and sintering. The gallium source, the nickel source and the zirconium source are used as raw materials in the form of salt at the same time, the prepared ZnO voltage-sensitive ceramic has large discharge-current capacity, high voltage gradient, low leakage current and low residual voltage ratio, the comprehensive performance meets the ionization protection requirement, for example, the ZnO voltage-sensitive ceramic is used for overvoltage protection of lightning protection insulators and ionization equipment.

The invention discloses ZrO2-doped reinforced cold-sintered ZnO voltage-sensitive ceramic and a preparation method thereof.The preparation method comprises the steps that initial ZnO powder and multiple metal oxide dopants including ZrO2 are mixed to form precursor powder, then the precursor powder and a prepared acetic acid solution are mixed, ground and dispersed to obtain mixed slurry, the mixed slurry is put into a mold, the mold is subjected to cold sintering, and the ZrO2-doped reinforced cold-sintered ZnO voltage-sensitive ceramic is obtained; and pressurizing for cold sintering, and then matching with an annealing process to obtain the high-performance ZnO-based voltage-sensitive ceramic. The doped ZrO2 serves as a high-quality intermediate phase and greatly hinders growth and combination of crystal grains, compared with a common heat treatment auxiliary cold sintering process, the heat treatment temperature is lower, volatilization of a doping agent is greatly reduced, and the service life of the material is prolonged. Therefore, the crystal grain size is extremely small, the leakage current is extremely low, and excellent electrical characteristics of a breakdown electric field of 713V / mm and a nonlinear coefficient of 45.75 are obtained. The preparation method is suitable for being applied to high-performance electronic components, energy consumption is reduced, and the electrical property of the ceramic is improved.

The application relates to the technical field of solid-liquid dual-purpose samplers, and discloses a solid-liquid dual-purpose sampler for zinc oxide pressure-sensitive ceramic and a sampling method, which comprises a sampler body, a sampling assembly and an adjusting assembly. The sampling assembly is assembled on the top of the sampler body in a plug-in mode, the adjusting assembly is assembled in the sampler body in a sliding mode, the adjusting assembly is located below the sampling assembly, and the sampler body is fixedly provided with a controller in the inside. When sampling, the granularity of the material is reflected according to the detection value of the pressure sensor, the expansion degree of the expansion air bag is adjusted according to the granularity, corresponding discharging operation is realized according to different material granularity, and it is ensured that the material does not stay in the sampler. When liquid sampling is completed and sample discharging is performed, the expansion air bag inputs gas into the exhaust pipe, the residual liquid is blown dry, and the sample is prevented from being polluted in the next use.

The application discloses a kind of superhigh voltage gradient and nonlinear coefficient dysprosium acetate solution method doped ZnO voltage-dependent ceramic and preparation method, the ZnO voltage-dependent ceramic is composed of ZnO, voltage-dependent forming agent Bi2O3 and voltage-dependent enhancer CoO, Mn2O3, Cr2O3, SnO2, CaO, Dy (C2H3O2) 3·4H2O, wherein ZnO content is 95.15~96.04mol%, voltage-dependent forming agent Bi2O3 content is 1.0mol%, voltage-dependent enhancer Co3O4, MnO2, Cr2O3, SnO2, CaO is 0.5mol%, 0.5mol%, 0.5mol%, 1.0mol% and 0.45mol% respectively, and the content of Dy (C2H3O2) 3·4H2O is 0.01~0.9mol%.Dy (C2H3O2) 3·4H2O in the application is modifier and sintering aid.The application also provides a kind of preparation method of the above-mentioned superhigh voltage gradient and nonlinear coefficient ZnO voltage-dependent ceramic.The application solves the problem that existing high-voltage voltage-dependent ceramic preparation method is difficult to obtain high-voltage voltage-dependent ceramic with poor performance, and the preparation method of the application has the advantages of simple process, low energy consumption, green environmental protection and the like.

Multilayer component (1) comprising a ceramic base body (2) and at least one metal structure (3, 5, 6), wherein - the metal structure (3, 5, 6) is co-sintered, - the base body (2) is a varistor ceramic sintered with liquid phases and has the following composition: - ≥ 95 % Mol ZnO, - from 0.5 to 5% mol Sb2O3, - from 0.05 to 2% mol CO3O4, Mn2O3, SiO2 and / or Cr2O3, - < 0.1 % mol B2O3, Al2O3 and / or NiO, - the metal structure (3, 5, 6) has silver and / or palladium and, - the ceramic base body (2) has a doping with material of the metal structure (3, 5, 6).

This invention relates to the field of varistor ceramics technology, and discloses a zinc oxide varistor ceramic, its preparation method, and its applications. The zinc oxide varistor ceramic comprises the following raw materials: 90.3-95.4 wt% zinc oxide, 2-4 wt% bismuth oxide, 1.5-2.5 wt% antimony oxide, 0.5-1.5 wt% cobalt oxide, 0.3-0.8 wt% manganese oxide, 0.2-0.6 wt% silicon oxide, and 0.1-0.3 wt% aluminum oxide. The zinc oxide varistor ceramic has a density ≥95% and a grain size distribution between 5 and 15 μm. The zinc oxide varistor ceramic of this invention has high density, uniform grain size, excellent performance, high nonlinear coefficient, strong surge current carrying capacity, low leakage current, and stable performance. It can be widely used for overvoltage protection in medium and high voltage power systems, electronic equipment, and communication equipment.

The application provides an insulator shed sheath, which comprises an insulator shed sheath layer and an insulator shed sheath anti-aging layer wrapped outside the insulator shed sheath layer; the shed sheath layer is made of silicon rubber mixed with pressure-sensitive ceramic; the pressure-sensitive ceramic is MnO2-ZnO-SnO2-based ceramic; the molar fraction of each component of the MnO2-ZnO-SnO2-based ceramic is (0.05-1%) MnO2:(90-99.5%) ZnO:(1-10%) SnO2; the insulator shed sheath anti-aging layer comprises a crosslinking agent, a catalyst, a plasticizer, a flame retardant and a reinforcing aid. By coating an insulator shed sheath anti-aging layer outside the insulator shed sheath layer, the anti-aging performance of the insulator shed sheath is improved and the service life is prolonged through the synergistic effect between the material layers.

The application discloses a kind of based on heat treatment auxiliary cold sintering ZnO base pressure-sensitive ceramic preparation method, including with deionized water and citric acid preparation citric acid solution;Initial ZnO powder is mixed with metal oxide dopant to constitute precursor powder, then precursor powder is mixed with citric acid solution, obtains mixed slurry after grinding dispersion;Mixed slurry is placed in steel mould, pressure is applied, and cold sintering is carried out;The sample after cold sintering is heat treated, and finally high-performance ZnO base pressure-sensitive ceramic is obtained.The application prepares ceramic with relative density up to 99% under the condition of ≤950 DEG C, the prepared ceramic also has excellent nonlinear coefficient up to 92, and 1600V / mm ultra-high breakdown strength, far more than ZnO base pressure-sensitive resistance prepared by solid phase method.Compared with traditional high-temperature sintering process, the application not only reduces sintering temperature, saves energy, and can significantly improve electrical performance.

The application discloses a chip type voltage-dependent resistor and electronic equipment, wherein the voltage-dependent ceramic main body of the chip type voltage-dependent resistor comprises a first material layer and a second material layer. The first material layer and the second material layer are stacked and arranged, and an internal electrode is arranged between the adjacent first material layer and the second material layer. The ceramic materials of the first material layer and the second material layer are different, and a potential gradient difference is formed between the adjacent first material layer and the second material layer. In the chip type voltage-dependent resistor disclosed by the application, the first material layer, the second material layer and the cover plate structure are stacked, and at least three internal electrodes can be arranged in the chip type voltage-dependent resistor. There is a potential gradient layer between two adjacent internal electrodes in the three internal electrodes, that is, at least two potential gradient layers are formed. When the two potential gradient layers are stacked, the chip type voltage-dependent resistor increases the response range to surges, so that the chip type voltage-dependent resistor can cope with a wide range of surges and avoid damage caused by surge impact on the chip type voltage-dependent resistor.

The application relates to low-voltage gradient zinc oxide pressure-sensitive ceramic and a preparation method and application thereof. By adjusting sintering pressure and content of a second phase, the pressure-sensitive voltage of undoped and doped pressure-sensitive ceramic can be effectively controlled, low-voltage gradient ZnO pressure-sensitive ceramic is obtained, and the problem that the existing zinc oxide pressure-sensitive ceramic cannot realize the low-voltage gradient characteristic is solved.