24 results about "Varistor ceramics" patented technology

The invention belongs to the technical field of functional ceramic materials, and particularly relates to luminous multifunctional ZnO-Bi2O3-based voltage-sensitive ceramic as well as a preparation method and application thereof. The luminous multifunctional ZnO-Bi2O3-based voltage-sensitive ceramic provided by the invention has up-conversion luminescence performance, can detect red emitted light under the excitation of 980nm laser, has a high nonlinear coefficient, is adjustable between 34 and 40.3, has excellent comprehensive performance, and can be used for ensuring the nonlinear coefficient alphagt; when the voltage is 30, the voltage-sensitive voltage is as low as 424.2 V / mm, the leakage current IL is as low as 1.8 [mu] A / cm < 2 >, the energy consumption is low, the cost is low, and the method is green and environment-friendly.

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 invention belongs to the technical field of voltage-sensitive ceramics, and particularly relates to a luminous ZnO-Bi2O3-based voltage-sensitive ceramic material and a preparation method thereof. The voltage-sensitive ceramic material is prepared from a voltage-sensitive modified material and a fluorescent material through solid-phase sintering, the molar ratio of the voltage-sensitive modified material to the fluorescent material is (1.8-2.8): 100, the voltage-sensitive modified material is MnO2, Sb2O3 and Bi2O3, and the molar ratio of the MnO2 to the Sb2O3 to the Bi2O3 is 0.5: 0.5: (0.8-2.8); the fluorescent material is ZnO and Er2O3, and the doping concentration of the Er2O3 in the fluorescent material is 0.2 mol%-0.6 mol%. According to the invention, a luminescence center is introduced into the ZnO-Bi2O3-based voltage-sensitive ceramic, so that the material is endowed with fluorescence characteristics while the microstructure and performance of the matrix are retained, and the potential application of the voltage-sensitive ceramic in the aspects of anti-counterfeiting and identification, intelligent sensing and indication and the like is expanded.

The application discloses a high-performance bismuth-free ZnO-Cr2O3-based pressure-sensitive ceramic and a preparation method and application of defect regulation, and belongs to the technical field of pressure-sensitive materials. The method comprises the following steps: ZnO, doped oxides, polyvinyl alcohol aqueous solution, tributyl phosphate and deionized water are ball-mixed to obtain mixed powder; after drying, sieving, granulating and compression molding, oxide-doped ZnO green bodies are obtained; after glue removal and sintering, high-performance bismuth-free ZnO-Cr2O3-based pressure-sensitive ceramic is obtained. The bismuth-free ZnO-Cr2O3-based pressure-sensitive ceramic is obtained by adopting a solid-phase sintering method, taking ZnO as main raw material, and doping multiple oxides for compression and sintering. Immovable acceptor defects and stable double Schottky barrier structures are formed in the oxides enriched at the ZnO grain boundaries, which provides an important technical thought for the electrical performance optimization of different system pressure-sensitive ceramics. The high-performance bismuth-free ZnO-Cr2O3-based pressure-sensitive ceramic has high nonlinearity coefficient and breakdown field strength and small leakage current density, and has a wide application prospect in miniaturized electronic circuit systems.

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 ​​

The invention discloses a zinc oxide voltage-sensitive ceramic resin encapsulation fixing method and a fixing hanger. According to the method, the center line in the length direction of the fixed hanger is taken as a starting point, and ceramic fixing clamps on which rows of zinc oxide voltage-sensitive ceramics are fixed extend towards the two ends in the length direction of the fixed hanger in an arithmetic progression decreasing mode respectively. The device comprises a square frame, a plurality of limiting holes are formed in the two sides of the square frame in the length direction, and a ceramic fixing clamp is arranged between the limiting holes in the two sides. The limiting holes in the same side take the center line in the length direction of the square frame as the starting point, and the limiting holes in the two sides extend towards the two ends in the length direction of the square frame in an arithmetic progression decreasing mode. The method is easy to operate, uniform diffusion of the resin powder can be achieved, sealing omission and reworking are reduced, and the product quality and the processing efficiency can be improved; the fixing hanging frame is simple in structure, reasonable in design, high in practicability, remarkable in effect and suitable for wide application and popularization.

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 present invention discloses a method and system for analyzing the defect distribution of piezoresistive ceramics, belonging to the technical field of piezoresistive ceramics. The method of the present invention comprises: cooling piezoresistive ceramics with different doping amounts or manufacturing processes to a first set temperature, and measuring the first dielectric response of the piezoresistive ceramics within a set frequency range; heating the piezoresistive ceramics to a second set temperature, and measuring the second dielectric response of the piezoresistive ceramics within a set frequency range; drawing a first frequency spectrum of the piezoresistive ceramics at the first set temperature based on the first dielectric response, and drawing a second frequency spectrum of the piezoresistive ceramics at the second set temperature based on the second dielectric response; extracting the slopes of the curves on both sides of the loss peak in the first and second frequency spectrums, and determining the defect distribution of the piezoresistive ceramics based on the slopes. The present invention achieves the characterization of the defect distribution of piezoresistive ceramics, providing a new approach to aging detection of piezoresistive ceramics.

The application discloses a kind of based on impedance circle ZnO voltage-dependent ceramic stability evaluation and device.Method includes: at preset temperature and given frequency, the impedance test is carried out to newly-made ZnO voltage-dependent ceramic, determines the first impedance circle of ZnO voltage-dependent ceramic;After a predetermined period of time, the impedance test is carried out to ZnO voltage-dependent ceramic at preset temperature and given frequency, determines the second impedance circle of ZnO voltage-dependent ceramic;According to the first impedance circle and the second impedance circle, determine the impedance change rate of ZnO voltage-dependent ceramic;According to impedance change rate, determine the stability of ZnO voltage-dependent ceramic.Long-term stability of ZnO voltage-dependent ceramic is effectively evaluated.

The automatic stripping system comprises an operation table, a stripping groove is formed in the operation table, a discharging opening is formed in one end of the stripping groove, an automatic stripping machine is arranged above the discharging opening, and an automatic pushing mechanism is arranged on one side of the stripping groove; the automatic stripping machine comprises a stripping assembly and a position sensing assembly. The stripping assembly comprises a stripping knife, and the stripping knife is connected with a reciprocating driving device; the position sensing assembly comprises a linkage plate, and the horizontal plane of the lower end of the linkage plate is lower than the horizontal plane of the lower end of the stripping knife; the linkage plate and the stripping knife are positioned on the same vertical surface, and the vertical surface is parallel to a gap surface during stripping of the zinc oxide voltage-sensitive ceramic; and a microswitch is arranged on the linkage plate. The system provided by the invention has the characteristics of high automation degree, time and labor saving, high stripping efficiency, accurate and controllable operation, small fragment risk, reliable product quality and reasonable design.

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 invention relates to a surface insulation treatment method suitable for chip zinc oxide voltage-sensitive ceramic before electroplating, and belongs to the technical field of special equipment or methods for manufacturing resistors. The surface insulation treatment method suitable for the chip type zinc oxide voltage-sensitive ceramic before electroplating comprises the following steps: soaking the zinc oxide voltage-sensitive ceramic in a surface treatment solution, taking out the zinc oxide voltage-sensitive ceramic, drying the zinc oxide voltage-sensitive ceramic, and performing heat treatment to obtain the chip type zinc oxide voltage-sensitive ceramic with a surface insulation layer, the surface treatment liquid comprises the following components: zinc oxide, zinc dihydrogen phosphate, sodium fluoride, bismuth nitrate, nitric acid and water. According to the treatment method, a uniform and firm insulating layer can be formed on the surface of the chip zinc oxide voltage-sensitive ceramic, and the problem of overplating of chip voltage-sensitive resistor electroplating can be effectively solved.

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 invention discloses a chip varistor and electronic equipment, and a voltage-sensitive ceramic main body of the chip varistor comprises a first material layer and a second material layer. The first material layer and the second material layer are stacked, and an inner electrode is arranged between the adjacent first material layer and second material layer. The first material layer and the second material layer are made of different ceramic materials, and potential gradient difference is formed between the adjacent first material layer and second material layer. When the first material layer, the second material layer and the cover plate structure in the chip varistor disclosed by the invention are stacked, at least three inner electrodes can be arranged in the chip varistor. A potential gradient layer exists between every two adjacent inner electrodes in the three inner electrodes, namely at least two potential gradient layers are formed by the three inner electrodes. And when the two potential gradient layers are overlapped, the surge response range of the chip piezoresistor is enlarged, so that the chip piezoresistor can cope with large-range surges, and the chip piezoresistor is prevented from being damaged due to surge impact.

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.