21results about How to "High sintering activity" patented technology

The application provides a ceria / yttria composite stabilized zirconia grinding medium and a preparation method. The method comprises the following steps: step one, mixing zirconia, ceria, yttria and kaolin, and then adding an appropriate amount of dispersant and water to obtain a slurry; step two, performing centrifugal spray drying on the slurry to obtain ceria / yttria composite stabilized zirconia powder; step three, adding the ceria / yttria composite stabilized zirconia powder into a binder, and then rolling to form a green body of spherical grinding medium; and step four, sintering and polishing the green body of spherical grinding medium to obtain the ceria / yttria composite stabilized zirconia grinding medium. The method can obtain low particle size and high specific surface area through high-temperature ball milling, and can also promote the solid solution of the stabilizer into the zirconia crystal lattice through heat treatment, so as to improve sintering activity, reduce sintering temperature and reduce production cost.

The application discloses a preparation method of a high-strength aluminum nitride substrate and relates to the technical field of aluminum nitride substrate preparation. The method comprises the following steps: preparing modified aluminum nitride powder; adding a non-oxygen composite sintering aid composed of fluorides and borides to the modified aluminum nitride powder to obtain a mixture; the adding amount of the composite sintering aid is 0.5wt%-5wt% of the total mass of the modified aluminum nitride powder; the mixture, a binder and a dispersant are mixed in a planetary ball mill to obtain a uniform slurry; the slurry is subjected to flow casting to form a green porcelain embryo, and then, glue removal treatment is performed under the protection of flowing inert gas to remove the binder; the green porcelain embryo after glue removal is placed in an atmosphere sintering furnace to perform a multi-stage temperature rising sintering procedure to form a ceramic body; and the sintered ceramic body is subjected to heat treatment and then cooled to obtain the aluminum nitride substrate. The application reduces the lattice thermal resistance of the aluminum nitride substrate and improves the mechanical strength of the aluminum nitride substrate.

The invention discloses a (Ti, W) C-AlCrCoNiMo high-entropy metal ceramic material as well as a preparation method and application thereof, and belongs to the technical field of metal ceramic materials. The invention provides a metal ceramic material which is prepared by taking (Ti, W) C ceramic as a matrix, adding Al, Cr, Co, Ni and Mo as a high-entropy alloy binding phase, carrying out two-step wet-dry composite ball milling process treatment and carrying out spark plasma coupling high-frequency induction sintering. The problem of segregation can be solved after two-step wet-dry composite ball milling process treatment, ideal pre-alloyed powder is obtained, the components are more uniform, the dispersity is better, and the composite powder treated by an optimized ball milling method is sintered through spark plasma coupling high-frequency induction. And the high-entropy metal ceramic material with high bending strength, high hardness and excellent fracture toughness can be obtained at the sintering temperature of 1300 DEG C.

This invention discloses an active metal brazing paste and its preparation method. The active metal brazing paste is characterized by comprising brazing powder and a binder, wherein the binder component accounts for 8-20% by mass. The brazing powder comprises the following components by mass percentage: 10-30% nano-silver powder; 60-80% silver-copper alloy powder; 5-10% aluminum-silicon alloy powder / titanium-aluminum alloy powder; 2-5% titanium hydride powder. The binder comprises the following components by mass fraction: 75-90% solvent; 5-10% thickener; 2-4% surfactant; 1-2% dispersant; 2-5% thixotropic agent. Compared with the prior art, the active metal brazing paste of this invention has the following beneficial effects: the ceramic copper-clad laminate prepared by the active metal brazing paste has high connection reliability and excellent resistance to thermal cycling.

The invention relates to alumina toughened zirconia ceramic powder as well as a preparation method and application thereof. The invention develops a modification preparation method which integrates precise proportioning, multi-stage PH regulation and control, composite coating agent modification and controllable aging process, and definitely adopts a solid-to-liquid ratio of (50-200): (100-1500) (the solid-to-liquid mass ratio is (0.5-2): (1-15)) to ensure the stability of the slurry, so that uniform dispersion of powder, strong interface bonding and collaborative optimization of mechanical properties and chemical stability are realized. Compared with the prior art, the invention has the advantages of good powder dispersibility, strong phase interface bonding, high slurry stability, excellent ceramic mechanical properties and chemical stability, and the like.

This application relates to the field of infrared transparent ceramic materials technology. Specifically, an embodiment discloses an infrared transparent ceramic material and its preparation method. The preparation method includes: dissolving yttrium nitrate hexahydrate and magnesium nitrate hexahydrate in deionized water according to a stoichiometric ratio; adding citric acid and ethylene glycol as chelating agents and binders; stirring to form a transparent sol; subsequently evaporating and drying to obtain a gel; placing the gel in a muffle furnace for a two-step high-temperature foaming treatment to obtain composite nanoparticles; ball milling the nanoparticles and pre-firing to obtain biphasic nanoparticles; loading the pre-firing nanoparticles into a graphite mold and sintering under axial pressure using SPS technology to obtain ceramic sheets; after furnace cooling, annealing the ceramic sheets in air; and polishing to obtain the infrared transparent ceramic material. The method of this application reduces scattering losses caused by pores and grain boundaries, overcoming the technical challenge of simultaneously achieving broad spectral coverage and high transmittance.

The invention relates to the technical field of aluminum oxide preparation, in particular to calcined alpha aluminum oxide with high sintering activity and a preparation method thereof. The preparation method comprises the following steps: mixing an aluminum hydroxide raw material with boric acid to obtain a primary mixed raw material; mixing alumina seeds with the primary mixed raw material to obtain a secondary mixed raw material; wherein the adding mass m1 of the aluminum oxide seeds and the adding mass m2 of the boric acid meet the condition that m1: m2 is greater than or equal to 8: 1; and calcining the secondary mixed raw material to obtain calcined alpha alumina. According to the preparation method, the sintering activity of the calcined alpha alumina is synergistically improved through three key links of boric acid fluxing, alumina seed phase change promotion and mass ratio regulation and control of boric acid and alumina seeds. And finally, the calcined alpha-alumina with the original grain size of 2.75 mu m or less, the specific surface area of 0.85 m < 2 > / g or more and the sodium oxide content of 0.271% or less can be obtained, which shows that the calcined alpha-alumina has high sintering activity.

This invention discloses a method for preparing Zr-2.5Nb alloy by hot-pressing sintering coarse-grained pre-alloyed spherical powder below the β phase transformation temperature. The method includes: 1. Selecting coarse-grained spherical Zr-2.5Nb alloy pre-alloyed powder prepared by the plasma rotating electrode method as raw material; 2. Placing the raw material into a mold and placing it in a hot press furnace under vacuum; 3. Heating to a temperature below the β phase transformation temperature of Zr-2.5Nb alloy and holding at that temperature for hot-pressing sintering; 4. Cooling to room temperature to obtain a dense Zr-2.5Nb alloy. This invention utilizes the characteristics of coarse-grained spherical Zr-2.5Nb alloy pre-alloyed powder—namely, its fine grain structure, crystal defects, and metastable α′ martensitic phase transformation activity—to achieve efficient densification at lower temperatures and suppress grain coarsening, resulting in a Zr-2.5Nb alloy material with uniform structure, high density, and excellent overall performance, suitable for the field of biomedical implants.

The present application relates to the technical field of metal powder material preparation, and particularly relates to a porous silver powder, a preparation method and application, by introducing a carbonate foaming agent into raw materials, the carbonate foaming agent can react with nitric acid generated in a liquid phase reduction process of silver nitrate and a reducing agent to generate carbon dioxide bubbles, and the carbon dioxide bubbles play an inducing role in a silver microcrystal formation process, so that the generated silver powder has a rich pore structure and a high specific surface area. Compared with the porous silver powder in the prior art, the porous silver powder has a higher specific surface area and sintering activity, by controlling the addition amount of the foaming agent, the pore structure, the specific surface area and the sintering activity of the silver powder can be accurately controlled, and the control method is simple, and the problems of low pore structure and high cost in the preparation of the porous silver powder in the prior art are solved.

The application discloses a barium titanate-based dielectric energy storage ceramic material with low loss and high energy storage efficiency and a preparation method thereof. The barium titanate-based dielectric energy storage ceramic material belongs to the field of dielectric functional ceramics and has a chemical composition of 0.85[0.88BaTiO3-0.12Bi 2 / 3 Mg 1 / 3 Ta 2 / 3 O3]‑0.15CaZrO3+xwt.%MnO2: wherein 0.5≤x≤2, x is a molar percentage, and the barium titanate-based energy storage ceramic doped with multi-ions Bi 3+ , Mg 2+ , Ta 5+ , Ca 2+ , Zr 4+ and MnO2 with different mass percentages has excellent energy storage efficiency and density, low loss, and is used for dielectric capacitors, and thus can be used in the fields of electronic power, military industry and high-energy pulse power technology.

The invention belongs to the technical field of advanced ceramic material preparation, and particularly discloses high-performance nearly-spherical zirconium oxide feeding powder and a preparation method thereof, and the method comprises the following steps: (1) preparing composite precursor liquid; (2) graded controllable thermal conversion; and (3) post-treatment: carrying out heat treatment on the product obtained in the step (2) in an oxidizing atmosphere at 500-700 DEG C for 0.5-3 hours to obtain the zirconium oxide powder. The special structure powder with the dense outside and the inner holes is prepared. The smooth and compact surface endows the powder with excellent fluidity; the internal uniform closed nano-pores properly reduce the particle density and further facilitate flowing, and more importantly, the pores can partially absorb a binder during feed preparation and play roles in'internal stress buffering 'and binder distribution optimization, so that higher powder loading capacity is allowed under the same viscosity, and the feed preparation efficiency is improved. Or lower viscosity and better rheological property can be obtained under the same loading capacity.

The invention discloses low-cost submicron silver powder capable of being quickly sintered at low temperature and a preparation method thereof, and belongs to the technical field of silver powder preparation. The preparation method comprises the following steps: preparing a nano-emulsion which is obtained by pouring an emulsifier ethanol solution into an organic alkali aqueous solution and stirring until the solution is clarified, and the mass ratio of an emulsifier to organic alkali in the nano-emulsion is 2: 1; preparing a silver nitrate aqueous solution and a reducing agent aqueous solution; the preparation method comprises the following steps: adding PVP K90 into water to prepare a reaction base solution, adding a nano-emulsion accounting for 0.9-1.1% of the total mass of silver nitrate into the reaction base solution, and uniformly stirring for later use; and under stirring, a silver nitrate aqueous solution and a reducing agent aqueous solution with the same volume are all dropwise added into the reaction base solution at the same flow speed, then organic salt is added for flocculation, stirring is stopped after flocculation is finished, suction filtration is conducted on the obtained reaction solution, obtained sediment is washed and dried, and the submicron silver powder is obtained. The submicron silver powder is prepared by adding the organic salt to destroy the colloid steady state.

This invention discloses a method for preparing functional materials by synergistic Joule heating sintering of dual-state powders. First and second ball-milled powders are prepared according to a target composition. The first ball-milled powder undergoes a first rapid Joule heating pretreatment to obtain a pre-Joule-heat-treated powder. The second ball-milled powder, used as the ball-milling active powder, is mixed with the pre-Joule-heat-treated powder, cold-pressed, and then rapidly Joule-heat-sintered without external densification pressure to obtain a sintered functional material. Optional post-current treatment is performed. The two types of powders have the same, similar, or complementary compositions, and the overall composition after mixing corresponds to the target functional material. The pre-Joule-heat-treated powder provides the phase composition basis, while the ball-milling active powder participates in local reactions, particle bonding, and pore filling, achieving rapid and complete forming. The post-current treatment is used to regulate the phase composition, defect state, and functional properties. This method is applicable to the rapid preparation and optional post-treatment of inorganic functional materials.

The invention relates to the technical field of aluminum oxide material preparation, in particular to a preparation method of aluminum oxide granulation powder, which comprises the following steps: step 1, raw material pretreatment: alpha-aluminum oxide micro powder with the purity of more than or equal to 99.9% is selected as a main material, and the average particle size of the alpha-aluminum oxide micro powder is 0.5-2 mu m; adding gamma-alumina micro-powder which accounts for 0.5-1.5% of the mass of the alpha-alumina micro-powder into the alpha-alumina micro-powder to serve as a sintering aid, wherein the average particle size of the gamma-alumina micro-powder is 50-100nm; according to the preparation method, alpha-aluminum oxide and nano gamma-aluminum oxide are reasonably proportioned, and efficient dispersion of the planetary ball mill is combined, so that the problem of agglomeration of the aluminum oxide micro powder is effectively solved; a polyvinyl alcohol and methyl cellulose compound bonding system is adopted, so that the strength and the flowability of the granulation powder are synergistically improved; after segmented roasting modification, the granulated powder is high in sphericity degree, uniform in particle size distribution, stable in apparent density and excellent in sintering activity, and can meet strict requirements in the fields of high-end electronic ceramics, precision grinding and the like.

The invention provides a doped corrosion-resistant dioxin-resistant silicon carbide wear-resistant ceramic material, and relates to the technical field of advanced ceramic materials, the material comprises, by weight, 80-95 parts of silicon carbide powder, 1-10 parts of a functional dopant, 2-8 parts of a sintering aid, 2-5 parts of a flexibilizer, 0.5-3 parts of a dispersant, and 0.5-10 parts of a binder. The core function dopant is core-shell structure nano-powder with an anatase TiO2 core and a mixed valence Ce / Sn silicate shell, and is prepared through sol-gel and heat treatment. On the basis of keeping high strength and high wear resistance of silicon carbide ceramic, the material is successfully endowed with long-acting and stable chemical corrosion resistance and high-temperature dioxin catalytic degradation capability, and the material is suitable for extreme environments such as waste incineration and chemical engineering.

The application relates to a small-particle-diameter nano W-Re-Y2O3 alloy powder and a preparation method thereof. The small-particle-diameter nano W-Re-Y2O3 alloy powder comprises 79-94 wt.% of W, 10-20 wt.% of Re and 1-5 wt.% of Y2O3 according to mass percentage. The small-particle-diameter nano W-Re-Y2O3 alloy powder is prepared by a sol-gel method. Specifically, citric acid is dissolved in deionized water, then ammonium metatungstate, ammonium perrhenate and yttrium nitrate are added respectively, and water bath heating and stirring are carried out until a colloid is formed. After the colloid is dried and calcined, a nano oxide powder is obtained. The nano oxide powder is placed in a reaction furnace, and hydrogen reduction is carried out to obtain W-Re-Y2O3 powder. The application realizes the combination of W and Re at an atomic scale by using the sol-gel method, and Y2O3 particles are generated in situ during calcination, so that Y2O3 is uniformly mixed in the powder. The average particle diameter of the prepared alloy powder is about 12 nm, and the reduced powder does not need subsequent treatment. The preparation method is simple, the raw material cost is low, and the method is easy to realize large-scale production.

The invention provides an asymmetric solid oxide fuel cell / electrolytic cell connector assembly, a preparation method and a solid oxide fuel cell / electrolytic cell, the connector assembly is composed of an air side functional layer and a fuel side functional layer, the air side functional layer and the fuel side functional layer are both made of perovskite type rare earth chromate, and the air side functional layer and the fuel side functional layer are made of perovskite type rare earth chromate. The chemical composition is represented as La1-xAxCr1-y-zByCzO3-delta (0.2 < = x < = 0.4, 0 < = y < = 0.8, and 0 < = z < = 0.1); wherein A is selected from Ca or Sr, B is selected from Co or Fe, and C is selected from Zn, Ti or Cu; the sum of the doping amount of B and C in the air side functional layer is not lower than the sum of the doping amount of B and C in the fuel side functional layer; compared with the prior art, the asymmetric solid oxide fuel cell / electrolytic cell connector assembly provided by the invention has the advantages of excellent thermomechanical matching property and structural reliability, high conductivity, low ohmic loss, good sintering activity and preparation process compatibility, and good industrial application prospect.

The invention relates to silver powder internally provided with holes and a preparation method of the silver powder. The preparation method comprises the steps that a reducing solution containing a reducing agent, a dispersing agent, a surface modifying agent and nanocrystalline seeds and a silver solution containing silver nitrate are prepared; in the stirring state, the reducing solution is added into the silver solution for a reaction, after the reaction is conducted for a first preset time, a coating agent is added, after the reaction is continued for a second preset time, the reaction is ended, silver powder slurry is obtained, and the second preset time is longer than the first preset time; the silver powder slurry is subjected to solid-liquid separation, solids obtained through separation are cleaned, the cleaned solids are subjected to rinsing, secondary coating and drying, and the silver powder with the holes inside is obtained, so that the preparation method of the silver powder with the multiple holes inside is provided, the prepared silver powder has higher sintering activity, and the prepared silver powder has the good sintering performance. The preparation method is more suitable for the field of photovoltaic conductive silver paste, and the preparation method is simple and rapid, does not need complex subsequent treatment, is stable in reaction, and is beneficial to large-scale and continuous mass production.

The invention relates to a method for manufacturing an electrolyte sheet, an electrolyte sheet, and a solid oxide battery. The invention relates to a manufacturing method. Comprising the following steps: 1) providing a raw material composition comprising an oxide powder and a crystalline phase stabilizer powder, and the oxide substantially exists in a crystalline phase stable at room temperature in its pure state, 2) grinding the raw material composition to obtain a ground composition, wherein B / A1 = 0.53-0.67, where A1 is the particle size DV (50) of the oxide powder in the raw material composition and B is the particle size DV (50) of the polishing composition, 3) molding the polishing composition into a sheet, and 4) sintering the sheet to obtain an electrolyte sheet containing crystal grains obtained by stabilizing the oxide with the crystal phase stabilizer. According to the manufacturing method, the production process is shortened, the production efficiency is improved, and the method is more suitable for commercial production.

The application discloses a kind of micro-jet continuous preparation methods of micro-pleated spherical silver powder, to solve the problem that traditional stirring reaction method is difficult to continuously prepare high sphericity, high dispersibility and surface has regular micro-pleated structure silver powder using micro-jet mixing reaction mode.The method comprises: configuration and filtration silver precursor and reducing agent solution;Temperature is controlled to 15-35 DEG C respectively;Two solutions are pumped into Y type micro-jet reactor with flow ratio 1:1 by metering pump, and high-speed collision mixing is formed at a certain flow and angle at the reactor outlet, efficient mixing and reaction are realized;Add total addition amount is 1% of silver nitrate weight Gelatin and stearic acid as dispersion stabilizer to inhibit agglomeration and control wrinkle morphology;After suction filtration, washing and vacuum drying, the product is obtained.By using the above technical scheme, continuous, high-stability preparation of micro-pleated high-sphericity silver powder can be realized, and the process method is easy to expand production by modularization.

The invention relates to the technical field of preparation of metal composite powder, in particular to a preparation process of tungsten-copper alloy powder, which comprises the following steps: S1, precursor compounding: performing electrochemical replacement reaction on a tungsten-containing substance and a copper-containing substance in a liquid phase to prepare a tungsten-copper composite precursor suspension; s2, freeze drying: performing spray freeze drying on the tungsten-copper composite precursor suspension to obtain fluffy porous precursor powder; and S3, reduction: performing low-temperature heat treatment on the precursor powder in a reducing atmosphere to obtain the tungsten-copper alloy powder. According to the method, copper atoms are directly subjected to reduction deposition on active sites of tungsten by utilizing the characteristic that electrochemical replacement reaction is carried out spontaneously, compounding on the atomic scale is achieved, and compared with physical mixing and surface coating of a copper plating method in the prior art, the uniformity of tungsten-copper two-phase mixing is effectively improved.