1256 results about "Alumina ceramic" patented technology

The invention relates to the technical field of nano ceramic materials, and discloses a high-strength nano aluminum oxide ceramic product and a preparation process thereof.The preparation process comprises the following preparation steps that aluminum oxide powder, a composite binder, composite gel, a plasticizer and a solvent are mixed and subjected to ball milling, and composite slurry is obtained; placing the composite slurry in a mold, and performing mold pressing and drying to obtain a green body; and putting the green body into a high-temperature sintering furnace, carrying out high-temperature sintering, and cooling to room temperature to obtain the nano aluminum oxide ceramic product. Nano zirconium oxide and nano magnesium oxide are formed on the surfaces of the pretreated silicon carbide whiskers, and can form a solid solution with nano aluminum oxide in the sintering process to serve as a bridge of the silicon carbide whiskers and nano aluminum oxide particles, so that the binding force of the silicon carbide whiskers in a nano aluminum oxide ceramic matrix is remarkably enhanced; phosphoric acid and aluminum ammonium sulfate are firmly combined on the surfaces of nanometer aluminum oxide particles through carboxymethyl cellulose, and the situation that phosphoric acid and aluminum ammonium sulfate are not firmly combined with the nanometer aluminum oxide particles is avoided.

The invention relates to the technical field of electronic ceramic materials, and particularly discloses a high-purity aluminum oxide ceramic substrate and a preparation process thereof. The high-purity aluminum oxide ceramic substrate is prepared from the following raw materials in parts by weight: 0.20 to 0.25 part of magnesium oxide, 0.35 to 0.55 part of zirconium oxide, 1.2 to 1.5 parts of dispersing agent, 60 to 65 parts of ethanol, 99.7 to 99.8 parts of aluminum oxide, 12 to 15 parts of adhesive, 6 to 9 parts of plasticizer and 50 to 55 parts of n-butyl alcohol, the adhesive is a mixture of polyvinyl butyral, water glass and modified paraffin. The prepared high-purity aluminum oxide ceramic substrate has excellent chemical stability and mechanical strength, and the obtained aluminum oxide ceramic substrate has better density, mechanical property and thermal stability by mixing various raw material components, and is not easy to break when subjected to bending load.

The invention discloses a preparation process of an aluminum oxide ceramic material, which comprises the following steps: S1, pretreatment of aluminum oxide powder: taking alpha-Al2O3 powder as a raw material, adding a dispersion medium, carrying out ball milling, transferring into an ultrasonic dispersion machine, dispersing, and further carrying out vacuum drying to obtain pretreated aluminum oxide powder; s2, chemical activation treatment: weighing pretreated aluminum oxide, magnesium oxide, nano silicon dioxide, calcium oxide, zirconium dioxide, titanium dioxide and modified nano silicon carbide in parts by weight, mixing, sequentially adding a dispersing agent absolute ethyl alcohol and a KH550 silane coupling agent, stirring at a high speed, adding a polyvinyl alcohol binder, and continuously stirring to obtain ceramic slurry; s3, sieving the ceramic slurry, filling the ceramic slurry into a mold, and performing isostatic pressing to obtain a ceramic green body; and S4, putting the ceramic green body into a box-type sintering furnace, sintering step by step, and cooling to room temperature along with the furnace to obtain the aluminum oxide ceramic material. The prepared aluminum oxide ceramic material has high compactness, excellent dielectric strength and mechanical property, low energy consumption and great application potential.

The invention discloses reflection-heat insulation dual-functional aluminum oxide ceramic and a preparation method and application thereof.The method comprises the steps that after surface silanization treatment is conducted on nanoscale hollow oxide filler, surface-modified nanoscale hollow oxide filler is prepared; and then adding the surface-modified nanoscale hollow oxide filler into a high-molecular polymer and a mixed polar solvent to obtain the thermal insulation coating. The method comprises the following steps: coating the surface of aluminum oxide ceramic with a heat insulation coating to form a primary coating, and carrying out gradient heating curing to obtain aluminum oxide ceramic with a functionalized heat insulation coating; and coating the surface of the thermal insulation coating functionalized aluminum oxide ceramic with an infrared reflection coating, and carrying out annealing treatment in a nitrogen atmosphere to prepare the reflection-thermal insulation dual-functionalized aluminum oxide ceramic. By constructing a double-layer composite structure, enhancing interface thermal resistance through chemical bonding, directionally distributing the nanofiller and designing a low-radiation layer structure, heat conduction and radiation heat transfer of the aluminum oxide ceramic-based material are synergistically reduced, and the high-temperature heat insulation performance of the aluminum oxide ceramic-based material is improved.

The invention relates to an anti-static black aluminum oxide ceramic substrate and a preparation process thereof. The ceramic substrate comprises ceramic powder, an organic solvent, a dispersing agent, a binder and a plasticizer. The black aluminum oxide ceramic substrate is prepared through the processes of tape casting, warm pressing and sintering. The ceramic powder comprises the following materials in parts by weight: 40-55 parts of aluminum oxide, 2.5-5 parts of nano semiconductor whiskers, 5-20 parts of special anti-static black pigment, 20-30 parts of an organic solvent, 1-3 parts of a dispersing agent, 5-8 parts of an adhesive and 3-7 parts of a plasticizer. The special anti-static black pigment can form a continuous conductive phase, and static accumulation is reduced. The added nano semiconductor whiskers have certain conductivity, and the whiskers form a conductive and heat-conducting network channel in the substrate through a warm-pressing process, so that generated electrostatic charges can be discharged in time, and meanwhile, the heat dissipation performance of the substrate is further enhanced. The light-shielding and light-absorbing material has good light-shielding and light-absorbing performance, and is suitable for photosensitive integrated circuits, semiconductor components, nixie tube packaging shells and the like. The problem that electronic components are damaged due to static electricity accumulation generated in the manufacturing and using processes of the electronic devices is effectively solved.

The invention relates to the technical field of dispersing agents for ceramics, and discloses a preparation method of a dispersing agent for ceramics, and the novel dispersing agent for ceramics is prepared by taking methoxypolyethylene glycol, bromoacetyl bromide, 4-hydroxyphthalic anhydride, 2, 4, 6-diethanolamine amino-1, 3, 5-s-triazine and the like as raw materials. The polyether polyol contains a plurality of carboxyl groups, has strong interaction with the surface of ceramic powder such as aluminum oxide, has a star-shaped multi-arm polyether molecular chain, can well coat the aluminum oxide powder, can effectively inhibit the growth of crystal nucleus particle size of the aluminum oxide powder, reduces the particle size of the aluminum oxide, and avoids agglomeration and sedimentation of the aluminum oxide; the modified aluminum oxide ceramic powder has good activation degree in solvents such as water, ethanol, dichloromethane or N, N-dimethylformamide and the like, is lower in settling volume and shows excellent dispersing performance.

The invention belongs to the technical field of friction catalysis, and particularly relates to application of an aluminum oxide substrate in friction catalytic degradation of high-concentration organic dye wastewater, an aluminum oxide ceramic chip is used as a substrate, titanium dioxide nano powder is used as a catalyst, and the aluminum oxide ceramic chip is fixed at the bottom of a flat-bottom glass beaker; the method comprises the following steps: adding organic dye wastewater, a magnetic turntable and titanium dioxide nano powder into a flat-bottomed glass beaker, then putting the flat-bottomed glass beaker in a dark environment at room temperature, stirring and reacting on a magnetic stirrer for 90-150 minutes, and after the reaction is completed, completely degrading organic dye in the wastewater. According to the method, the aluminum oxide ceramic chip is added into a system for performing friction catalytic degradation on the organic dye wastewater by using the titanium dioxide nano powder as the substrate, so that the degradation rate of the organic dye is greatly improved, the complete degradation time of the organic dye is shortened, and a new thought is provided for performing friction catalytic degradation on the organic dye wastewater by using the titanium dioxide nano powder.

The invention discloses a preparation method of fine-grain aluminum oxide ceramics, and belongs to the technical field of electrostatic chucks, the preparation method comprises the following steps: powder pretreatment: dispersing nano aluminum oxide powder in a horizontal ball mill, adding a second-phase additive accounting for 1-10% of the total volume fraction, and uniformly stirring; mixing a second phase additive with a solvent, then adding a structure-directing agent PEG and a dispersing agent, carrying out ball milling in a planetary ball mill, and finally transferring the obtained solution into a vertical stirring mill for grinding; sol: firstly adding 60 parts of toluene, 20 parts of isopropanol and 20 parts of plasticizer into a pneumatic sol machine, and then adding 30-50 parts of adhesive; dispersing: weighing a certain amount of 3mm balls and a mixed solvent of methylbenzene and n-butyl alcohol into a stirring mill, then adding the pretreated nano aluminum oxide powder, and stirring; mixing: adding PVB colloid and transferring into a defoaming tank; vacuum defoaming: feeding the slurry in the roller ball mill into a defoaming tank by using N2 air pressure; and forming and sintering.

The utility model relates to the technical field of resistors, in particular to an anti-vulcanization moisture-resistant thick-film resistor. According to the technical scheme, the resistor comprises an aluminum oxide ceramic substrate, a resistor body is printed on the upper surface of the aluminum oxide ceramic substrate, front electrodes are printed at the two ends of the resistor body, extending parts of the two ends of the resistor body are covered with the front electrodes, back electrodes are printed on the lower surface of the aluminum oxide ceramic substrate, and the aluminum oxide ceramic substrate is provided with side electrodes. The front electrode, the back electrode and the side electrode are all silver electrodes, a nickel electrode is arranged outside the silver electrodes, a tin electrode is arranged outside the nickel electrode, and a first anti-vulcanization layer is arranged between the silver electrode and the nickel electrode at the two ends of the resistor body. A second anti-vulcanization layer is arranged between the nickel electrode and the tin electrode at the two ends of the resistor body, and a first protective layer and a second protective layer are arranged on the surface of the resistor body.

The invention relates to the technical field of ceramics, and discloses an aluminum oxide ceramic glaze based on domestic waste ceramics, and a preparation method and application thereof. The aluminum oxide ceramic glaze comprises the following raw materials in parts by weight: 28-42 parts of domestic waste ceramic, 25-30 parts of kaolin, 6-12 parts of calcined talc, 3-7 parts of borax, 6-14 parts of aluminum oxide, 3-5 parts of zirconium oxide, 1-3 parts of lanthanum oxide and 3-6 parts of self-repairing particles. The self-repairing particles comprise mesoporous alumina doped with Si and Zr, and V2O5-B2O3-TeO2 series glass which is filled in pores of the mesoporous alumina and has a softening point of 200-300 DEG C. After the glaze is applied to the surface of the aluminum oxide ceramic to form a glaze layer, the insulativity of the aluminum oxide ceramic can be effectively improved, meanwhile, the high bonding stability between the glaze layer and the aluminum oxide ceramic can be achieved, and the problems that the insulativity is greatly reduced and the glaze layer cracks during heat circulation are solved.

The invention relates to the technical field of brazing processes, in particular to a brazing process for connecting aluminum oxide ceramic and metallic titanium through low-activation brazing filler metal. According to the technical scheme, the method comprises the following steps that a to-be-welded face of the aluminum oxide ceramic is subjected to magnetron sputtering titanium film plating, the sputtering power ranges from 80 W to 150 W, the argon pressure ranges from 0.5 Pa to 1.5 Pa, the film thickness ranges from 0.5 micrometer to 5 micrometers, inert gas annealing treatment is conducted after film plating, the annealing temperature ranges from 400 DEG C to 550 DEG C, and the heat preservation time ranges from 10 min to 30 min; and the surface of the metal titanium substrate is subjected to laser micro-texture treatment, and a periodic groove structure with the depth being 10-50 microns is formed. The problems of poor wettability of the brazing filler metal and the ceramic, low joint strength and joint stress cracks are solved, meanwhile, radioactive substances generated by the brazing filler metal under the irradiation condition can be released within a short time, the equipment maintenance period is greatly shortened, and the equipment service life is prolonged.

The invention relates to the technical field of ceramic substrates, and provides a bending-resistant aluminum oxide multilayer ceramic substrate and a preparation method thereof. The bending-resistant aluminum oxide multilayer ceramic substrate comprises the following raw material components in parts by weight: 95-110 parts of aluminum oxide, 3-8 parts of a plasticizer, 6-12 parts of an auxiliary agent, 4-7 parts of a binder, 3-6 parts of a dispersant and 60-70 parts of a solvent, the preparation method of the additive comprises the following steps: A1, adding calcium oxide into ethanol, adding glucose, stirring until the materials are uniformly mixed, and concentrating to obtain a glucose coated material; a2, carrying out annealing treatment on the glucose coated material to obtain a carbon coated material; and A3, uniformly mixing the carbon-coated material with magnesium oxide and titanium dioxide, and carrying out ball milling to obtain the auxiliary agent. According to the technical scheme, the problem of low mechanical property of the aluminum oxide ceramic substrate in the prior art is solved.

The invention provides a method for preparing a beta ''-aluminum oxide ceramic membrane through tape casting, and belongs to the field of conductive ceramic materials. The method comprises the following steps: carrying out first ball milling on a high-purity aluminum-containing compound, a sodium-containing compound, a stabilizer, a dispersant and a solvent to obtain first slurry; adding a binder, a plasticizer and a foam inhibitor into the first slurry to obtain second slurry; performing second ball milling on the second slurry to obtain third slurry; defoaming the third slurry to obtain fourth slurry with set viscosity; carrying out tape casting on the fourth slurry to obtain an aluminum oxide green body; and degumming, pre-sintering and sintering the aluminum oxide green body to obtain the beta ''-aluminum oxide ceramic membrane. Therefore, the beta ''-aluminum oxide ceramic membrane with controllable thickness, stable quality and low resistivity is obtained, and the application performance of the beta''-aluminum oxide ceramic membrane is improved.

The invention relates to the technical field of ceramic substrates, and provides a high-toughness aluminum oxide ceramic substrate and a preparation method thereof, the high-toughness aluminum oxide ceramic substrate comprises the following raw materials by weight: 100 parts of aluminum oxide, 1-3 parts of a plasticizer, 4-6 parts of an auxiliary agent, 4-6 parts of a binder, 1-3 parts of a dispersant, and 55-65 parts of water; the auxiliary agent is composed of an auxiliary agent A and an auxiliary agent B, the auxiliary agent A comprises rare earth oxide, and the auxiliary agent B is composed of molybdenum boride, scandium oxide and zirconium oxide. According to the technical scheme, the problem of low toughness of the aluminum oxide ceramic substrate in the prior art is solved.

The invention belongs to the field of semiconductor bridge current protection, and particularly relates to a semiconductor bridge current protection method based on a vanadium dioxide thick film thermistor. Firstly, copper, nickel and gold interdigital electrodes are deposited and grown on an aluminum oxide ceramic substrate, then a methanol solution of vanadyl acetylacetonate is sprayed on the surface of the heated interdigital electrode, a vanadium dioxide thermistor device is obtained, the vanadium dioxide thermistor device is connected with a semiconductor bridge in parallel, and current protection of the semiconductor bridge thermistor is achieved. Vanadium dioxide with a single valence state can be synthesized by adjusting the synthesis method and process, M-phase vanadium dioxide is synthesized on the interdigital electrode in one step, the vanadium dioxide prepared by the method avoids the tedious process that vanadium dioxide powder is firstly prepared and then transplanted to the surface of the interdigital electrode, and the preparation method is simple and convenient to operate. And the vanadium dioxide can be more stably combined on the surface of the interdigital electrode.

The invention belongs to the field of conductive aluminum oxide ceramic preparation, and particularly relates to a treatment method for performing carbon deposition infiltration on the surface of aluminum oxide ceramic to enable the aluminum oxide ceramic to have certain conductivity. According to the invention, wheat starch and corn starch are used as main raw materials and are converted into a volatile carbon source through a high-temperature carbonization process under the protection of inert gas; and placing the carbon source and aluminum oxide ceramic pre-subjected to conductive treatment in a high-temperature furnace protected by inert gas, and performing deposition carburizing treatment on the surface of the aluminum oxide ceramic at 800-900 DEG C to obtain the aluminum oxide conductive ceramic with certain conductivity. The method is low in raw material cost, low in sintering temperature of the related process, low in equipment investment, good in surface carburization uniformity of the aluminum oxide ceramic and stable in property.

The invention belongs to the technical field of metamaterial sensors, and particularly relates to a metamaterial multi-parameter sensor for a complex environment, which comprises a dielectric substrate, a temperature sensor, a pressure sensor and a strain sensor, and is characterized in that the dielectric substrate is made of high-temperature co-fired alumina ceramic; the temperature sensor is arranged at the left end of the dielectric substrate; the pressure sensor is arranged in the middle of the medium substrate; and the strain sensor is arranged at the right end of the dielectric substrate and comprises a metal sheet structure capable of generating relative displacement. According to the invention, long-distance signal monitoring is realized by adopting a microwave scattering technology, and the problem that a traditional wired sensing transmission line is damaged at a high temperature is solved; the high-temperature-resistant aluminum oxide HTCC ceramic is used as the dielectric substrate, temperature measurement within the range of 25 DEG C to 1200 DEG C, pressure within the range of 0 kPa to 700 kPa and strain measurement within the range of-400 mu epsilon to + 400 mu epsilon are achieved, the sensor is smaller in size and higher in sensitivity, and application of a traditional sensor in the multi-metal environment is expanded.

The invention discloses 95 aluminum oxide ceramic for a vacuum switch and a preparation method of the 95 aluminum oxide ceramic, and belongs to the technical field of aluminum oxide ceramic and vacuum switches. The ceramic disclosed by the invention is prepared from the following raw materials: 3 to 5 parts of nano alpha-aluminum oxide, 0.05 to 0.1 part of yttrium oxide, 0.04 to 0.08 part of lanthanum oxide, 0.3 to 0.6 part of zirconium silicate, 3.0 to 4.5 parts of fused quartz, 1 to 1.6 parts of magnesium fluoride, 0.3 to 0.5 part of calcium carbonate, 0.3 to 0.5 part of barium carbonate, 1.5 to 2.5 parts of Suzhou clay and 93 to 94 parts of micron alpha-aluminum oxide. The prepared high-performance 95 aluminum oxide ceramic has excellent breaking strength, electric breakdown strength, thermal shock resistance, chemical stability and the like, can meet the performance requirements of a high-pressure vacuum tube in a severe working environment, and ensures the working stability of a circuit.

The invention discloses a bimetallic Ag and Pd loaded WO3 material and a preparation method thereof, and relates to the technical field of sensor material preparation, and the preparation method comprises the following steps: 1, dissolving a tungsten source in an ethanol solution, mixing, hydrolyzing, aging, precipitating, washing, drying, calcining and cooling; 2, adding deionized water, adding a silver source solution and a palladium source, adding ascorbic acid, and stirring; 3, centrifuging, washing with ethanol and deionized water, and drying; 4, selecting a gold interdigital electrode with aluminum oxide ceramic as a substrate as a base electrode material, dipping the WO3 nano-particle dispersion liquid by using a line drawing pen, and uniformly coating the WO3 nano-particle dispersion liquid on the surface of the interdigital electrode; and 5, electrode drying and heat treatment. The efficient gas sensing material is prepared through the preparation method which is easy to operate, environmentally friendly and economical, and the gas sensing material has the advantages of being high in sensitivity, rapid in response, good in selectivity and the like at the low working temperature.

The invention discloses a production process of an aluminum oxide ceramic product. The method comprises the following steps: proportioning raw materials; static pressure forming; sintering and molding; and post-processing. According to the raw material ratio, high-purity aluminum oxide powder is selected as a basic raw material, and the purity of the aluminum oxide powder is not lower than 95%. Adding a proper amount of fluxing agent and additive according to the performance requirement of the required ceramic product; the preparation method comprises the following steps: uniformly mixing the raw materials according to a certain proportion, and carrying out refining treatment by adopting a ball milling process for 8-12 hours, so that the average particle size of the raw material particles reaches 0.5-1.5 microns. The preparation method has the beneficial effects that raw material particles are refined by optimizing a raw material formula and adopting a ball milling process, so that the uniformity and the sintering activity of a green body are improved, and the compactness and the mechanical property of a ceramic product are favorably improved; according to the forming technology combining dry pressing forming and isostatic pressing forming, the density and uniformity of the green body are effectively improved, defects in the green body are reduced, and therefore the yield of products is improved.

The invention provides a preparation method of a high-thermal-conductivity 99 aluminum oxide ceramic substrate, and belongs to the field of electronic ceramic materials. The method comprises the following steps: homogenizing and grinding a high-purity aluminum-containing compound and a modifier to obtain pretreated powder; mixing the pretreated powder with a carrier gas, and carrying out melt spheroidization to obtain a submicron spherical alumina precursor raw material; homogenizing and defoaming the submicron spherical aluminum oxide precursor raw material, an inorganic sintering aid, a dispersing agent, a binder, a plasticizer and a foam inhibitor in a solvent to obtain ceramic slurry; carrying out tape casting on the ceramic slurry to obtain an aluminum oxide green body; the alumina green body is subjected to rubber discharging, pre-sintering and sintering, and the 99 alumina ceramic substrate is obtained. The submicron spherical alumina powder is prepared through a melt spheroidizing process, the surface of the powder is smooth, particle size distribution is concentrated, grain boundary resistance between the powder is remarkably reduced, sintering densification is promoted, and therefore the technical problems that existing tape casting slurry is poor in stability and high in sintering temperature, and consequently microdefects are caused are solved.

The invention belongs to the technical field of magnetism isolating plates, and particularly relates to a novel magnetism isolating plate which comprises a composite plate, the composite plate is composed of an outermost wear-resistant and corrosion-resistant protective layer, a middle high-permeability magnetism isolating material layer and an inner buffer layer in good contact with protected equipment, and the outermost wear-resistant and corrosion-resistant protective layer can be made of PTFE (polytetrafluoroethylene). The surface of the magnet vane is covered with the coating in a spraying or dipping mode, a uniform protective layer is formed, and the thickness of the uniform protective layer is usually 20 microns 300; and the middle layer of high-permeability magnetic isolation material layer is permalloy composed of 45 N i-Fe alloy containing 45% of nickel and 80 N i-Fe alloy containing 80% of nickel. According to the invention, the outermost layer is wear-resistant and corrosion-resistant, such as a PTFE or aluminum oxide ceramic layer, so that the interior is protected; the middle high-permeability magnetic isolation material layer effectively isolates a magnetic field; the inner buffer layer provides buffer, the buffer holes disperse stress and absorb energy and buffer, and the interval grooves enhance the fitting degree, so that stable operation of equipment in various complex environments is ensured jointly, and the service life of the magnet vane and the service life of the equipment are prolonged.

The invention discloses a seawater conductivity sensor electrode material based on a copper-nickel-based nanostructure and a preparation method, the electrode material comprises: a substrate, a copper-nickel-based nanostructure layer being formed on the surface of the substrate; the substrate comprises an insulating compound and a coating coated on the surface of the insulating compound, the insulating compound comprises at least one of high-resistance silicon, silicon oxide, aluminum oxide ceramic and plastic, the coating comprises a metal coating and / or a semiconductor coating, and the copper-nickel-based nanostructure layer is in a dendritic crystal or cluster form. The copper-nickel alloy nanostructure is a core material of the electrode, so that the electrode material has high specific surface area and rich active sites, the measurement accuracy and measurement limit of the electrode material can be improved, the service life can be prolonged, the manufacturing cost can be reduced, and the application requirements of the ocean Internet of Things can be met.

The invention provides modified zirconium silicate whisker reinforced aluminum oxide ceramic as well as a preparation method and application thereof, and belongs to the technical field of new materials. The preparation method comprises the following steps: modifying the surface of alumina powder with a silane coupling agent with sulfydryl to generate zirconium silicate in situ, uniformly mixing the zirconium silicate with zirconium silicate whiskers which are treated by hydrogen peroxide and modified by phytic acid and tannic acid and a CeO2-Y2O3-MgO-SiO2 compound, and performing spark plasma sintering to obtain the modified zirconium silicate whisker reinforced alumina ceramic. The modified zirconium silicate whisker reinforced aluminum oxide ceramic prepared by the invention has better interface bonding force, excellent mechanical properties and good wear resistance, realizes ceramic densification, and has wide application prospects.

The invention relates to the technical field of ceramics, in particular to aluminum oxide ceramic slurry as well as a preparation method and application thereof. The aluminum oxide ceramic slurry is prepared from alpha-aluminum oxide coarse powder, alpha-aluminum oxide fine powder, modified aluminum oxide powder, acrylamide, N, N '-methylene bisacrylamide and deionized water, multiple active functional groups are introduced into the surface of the modified aluminum oxide powder, interface bonding of particles with a dispersion medium and a polymer monomer is enhanced, and the surface of the particles is improved. According to the present invention, with the preparation method, the particle agglomeration tendency is reduced, such that the slurry can maintain the low viscosity under the high solid content condition so as to meet the gel injection molding process requirements, and the sintering body obtained through the gel injection molding has characteristics of high bending strength and high hardness, and can be widely used in the fields of electronic devices, mechanical sealing members, biomedical apparatuses and instruments, and the like.

The invention relates to a mold for forming a large-size three-hole ceramic guide rail and a forming process, and belongs to the technical field of ceramic forming. The die comprises an auxiliary die sleeve, a rubber sleeve, a rubber plug, a positioning disc and a mandrel. The rubber plugs are located at the upper end and the lower end of the rubber sleeve, and the positioning disc and the mandrel are located in the rubber sleeve; integrated forming of the large-size aluminum oxide ceramic guide rail is achieved, the technical barrier of the manufacturing technology of the large-size aluminum oxide ceramic guide rail is overcome, and the domestic blank is filled up; the qualified large-size aluminum oxide ceramic guide rail for the large-size three-coordinate measuring machine is prepared through ingenious mold design and assembly, a tight sealing process, a novel demolding process and transfer tool design; according to the method, the product percent of pass is increased, and theoretical and technical support is provided for industrialization of the large-size three-hole guide rail.

The invention belongs to the technical field of ceramic material preparation, and particularly relates to a high-throughput preparation method and device based on an aluminum oxide ceramic system diffusion couple. An aluminum oxide model green body containing a plurality of blind holes is prepared through the powder extrusion 3D printing technology, a diffusion material is embedded through a rivet type structure, and the layering risk is eliminated in combination with the thermal expansion coefficient gradient design (the inner layer is large, and the outer layer is small); sPS low-temperature rapid sintering is adopted, and multiple binary diffusion couples are prepared at a time. According to the method, the problems that a traditional diffusion couple is not tight in contact, easy to layer and incapable of being produced in batches are solved, the efficiency is improved by 80% or above, diffusion couple samples of different materials can be prepared at the same time, multiple binary diffusion couple systems can be obtained through subsequent sample cutting, and the preparation method is simple, efficient, easy to operate and suitable for aluminum oxide and rare earth oxide systems.

The invention discloses a stannic oxide-based ammonia gas sensor as well as a preparation method and application thereof, relates to the technical field of gas sensors, and solves the problems of high detection lower limit, poor gas selectivity and low sensitivity of a traditional semiconductor ammonia gas sensor. A sensitive material based on oxygen vacancy regulation and control SnO2 / ZIF-67 is prepared on the surface of an interdigital gold electrode by adopting a chemical vapor deposition method, a planar electrode, an aluminum oxide ceramic substrate, a heater and a Pt wire are welded and packaged according to a general indirectly-heated gas sensitive element, and the SnO2 / ZIF-67 semiconductor ammonia gas sensor is prepared. The lower detection limit of the SnO2 / ZIF-67 semiconductor ammonia gas sensor is 1 ppm; meanwhile, the NH3 selectivity and sensitivity of the sensor are improved through the synergistic effect of SnO2 and ZIF-67, and the sensor can be used for detecting ammonia gas leakage and can be applied to judging the safety of ammonia gas in chemical production operation, environmental gas detection and other applications.

The application belongs to the field of ceramic fibers, and particularly relates to a preparation method of fine-crystal dense alumina ceramic fibers. The application first configures an aluminum sol, an iron sol, a PVP solution and an acidified silica sol, then mixes them according to a set proportion to obtain a mixed sol, concentrates the mixed sol to obtain a spinnable gel, heats the spinnable gel to 500-600 DEG C at a heating rate of 2-10 DEG C / min for pre-sintering after spinning, finally performs microwave sintering at 1000-1400 DEG C at a power of 3000-5000 W and a heating rate of 50-100 DEG C / min to obtain the fine-crystal dense alumina ceramic fibers. The application has simple and controllable process, and the obtained product has excellent performance and is convenient for large-scale industrial application.

The invention provides a black aluminum oxide ceramic material as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing aluminum oxide, magnesium oxide, silicon dioxide, iron oxide, manganese oxide, chromium oxide and a solvent to obtain an aluminum oxide ceramic mixed solution; (2) mixing the alumina ceramic mixed solution with a binder, and grinding to obtain alumina ceramic powder; and (3) carrying out cold pressing treatment on the aluminum oxide ceramic powder, and carrying out vacuum pressureless sintering treatment to obtain the black aluminum oxide ceramic material. The black aluminum oxide ceramic material prepared by the method disclosed by the invention is relatively small in crystal grain, relatively small in pore and relatively high in density, and has relatively high compactness and thermal conductivity.