363 results about "Sintered ceramic" patented technology

The invention discloses a preparation method of high-polarization bismuth ferrite-lead titanate-barium zirconate titanate-based ferroelectric ceramic, which comprises the following steps: preparing oxide raw materials according to the chemical formula of the bismuth ferrite-barium titanate ceramic-based ferroelectric ceramic, mixing to obtain mixed powder, pre-sintering the mixed powder to obtain pre-sintered powder, granulating the pre-sintered powder to obtain granules, and sintering the granules to obtain the high-polarization bismuth ferrite-lead titanate-barium zirconate titanate-based ferroelectric ceramic. Performing compression molding on the granules to obtain a green body, performing degumming sintering on the green body to obtain sintered ceramic, and performing annealing treatment on the sintered ceramic to obtain the bismuth ferrite-lead titanate-barium zirconate titanate based ferroelectric ceramic. According to the invention, annealing treatment is carried out on sintered ceramic, after annealing treatment, defect dipoles generated by volatilization of Pb and Bi in the ceramic are rearranged under the action of a temperature field, relaxor ferroelectric-ferroelectric phase change occurs in a ceramic phase, a ferroelectric hysteresis loop reflects that the girdling of the loop is opened, and the rectangularity is increased; a bipolar strain curve is converted into a typical butterfly shape of ferroelectric from a bud shape, and the ferroelectricity of the ceramic is further greatly improved.

The invention discloses a high-entropy lead-free energy storage ceramic material and a preparation method and application thereof. The preparation method comprises the following steps: S1, weighing: respectively weighing precursor raw materials according to a stoichiometric ratio for later use; s2, primary ball milling: mixing the weighed precursor raw materials and then carrying out ball milling; s3, pre-sintering: pre-sintering the slurry subjected to ball milling; s4, secondary ball milling: carrying out ball milling on the pre-sintered raw materials again, and drying to obtain pre-sintered ceramic powder; s5, molding: adding a binder into the pre-sintered ceramic powder, and then carrying out compression molding to obtain a ceramic blank; s6, glue discharging and sintering: heating the obtained ceramic green body, and then carrying out heat preservation treatment to obtain a glue-discharged green body; and then, sintering the rubber-removed green body. According to the magnesium-lanthanum co-doped high-entropy ceramic strategy, the relaxation behavior and voltage breakdown resistance of the ceramic material are remarkably improved, the polarization intensity is improved, meanwhile, high energy storage density and high energy storage efficiency are achieved, and the prepared high-entropy ceramic is good in comprehensive performance.

The invention discloses an environment-friendly ceramic and a preparation method thereof, and belongs to the field of ceramics, the method comprises the following steps: grinding and mixing kaolin, boric oxide, carbon powder, zirconium, barium carbonate, calcium carbonate, boron, silicon and titanium to obtain a mixture; mixing zinc nitrate, zirconium nitrate and a dispersing agent to obtain a mixed solution; mixing the mixture with the mixed liquid to obtain mixed slurry; preparing the mixed slurry into a blank body; putting the blank body into a sintering furnace, heating to 560-720 DEG C, and treating in a first treatment environment for 1.5-4 hours; the temperature of the sintering furnace is increased to 880-1130 DEG C, and treatment is conducted for 2-5 h in a second treatment environment; the temperature of the sintering furnace is increased to 1280-1420 DEG C, and treatment is conducted for 3-6 h in a third treatment environment; the temperature of the sintering furnace is increased to 1530-1620 DEG C, and treatment is conducted for 1-3 h in a fourth treatment environment; the first treatment environment, the second treatment environment, the third treatment environment and the fourth treatment environment comprise vacuum or inert atmosphere. The sintered ceramic is high in strength and good in wear resistance and corrosion resistance.

A method of manufacturing ceramic tape includes a step of directing a tape of partially-sintered ceramic into a furnace. The tape is partially-sintered such that grains of the ceramic are fused to one another yet the tape still includes at least 10% porosity by volume, where the porosity refers to volume of the tape unoccupied by the ceramic. The method further includes steps of conveying the tape through the furnace and further sintering the tape as the tape is conveyed through the furnace. The porosity of the tape decreases during the further sintering step.

The invention belongs to the technical field of ceramic slurry, and particularly relates to ceramic slurry and a preparation method and application thereof.The ceramic slurry comprises inorganic components and organic components, the inorganic components comprise inorganic additives and glass powder, the inorganic additives comprise Al2O3, ZrO2 and Y2O3, and the organic components comprise modified acrylic resin, organic solvent and auxiliaries. By controlling the relative content of carboxyl and ester groups in the modified acrylic resin and utilizing the polarity difference of functional groups, selective adsorption of inorganic powder is realized, so that the dispersion uniformity of the powder in the ceramic slurry is remarkably improved, segregation of yttrium oxide is effectively inhibited, and the service life of the ceramic slurry is prolonged. Therefore, monoclinic-phase zirconium oxide, tetragonal-phase zirconium oxide and cubic-phase zirconium oxide with a proper proportion can be formed in the sintered ceramic substrate, further the bending strength of the ceramic substrate is remarkably improved, and the ceramic substrate is particularly suitable for manufacturing miniaturized and thin electronic components.

A method for manufacturing a multilayer ceramic capacitor including an operation of preparing a ceramic green sheet; an operation of forming a conductive paste on the ceramic green sheet; an operation of forming a ceramic laminate by stacking a ceramic green sheet on which the conductive paste is formed; an operation of sintering the ceramic laminate; and an operation of forming an external electrode on an exterior of the ceramic laminate, wherein the conductive paste includes a first mixture including a metal powder, a dispersant, and a hydrophobic solvent and a second mixture including a hydrophilic binder and a hydrophilic solvent, the conductive paste being an emulsion in which the first mixture is dispersed in the second mixture.

The invention discloses a microwave sintering method and microwave sintering equipment for a ceramic roller, and relates to the technical field of ceramic roller preparation. The microwave sintering method comprises the following steps that a microwave multi-mode resonant cavity is adopted for microwave sintering, the microwave multi-mode resonant cavity comprises a sintering cavity and an outer cavity from inside to outside, the outer cavity is provided with a focusing reflector, and a heating area, a sintering area and a cooling area are sequentially formed in the sintering cavity from top to bottom; a microwave source is started, the working frequency and power of the microwave source are adjusted, and the temperature of the sintering area is made to range from 1200 DEG C to 1600 DEG C; the auxiliary heating base is placed in the sintering cavity; and enabling the ceramic roller to enter and pass through the sintering cavity at the speed V1 to be subjected to microwave sintering while keeping the rotary motion, so as to obtain the microwave sintered ceramic roller. According to the microwave sintering method and microwave sintering equipment for the ceramic roller, effective microwave sintering can be conducted on the aluminum oxide ceramic roller, the microwave sintering temperature reaches 1200 DEG C or above, and the ceramic roller can be heated more evenly through dynamic continuous sintering.

The invention relates to the technical field of ceramics, and particularly discloses green special refractory ceramic slurry as well as a preparation method and application thereof. The green special refractory ceramic slurry is prepared from aluminum oxide, methyltrimethoxysilane-phosphoric acid modified polysiloxane, fluorocarbon emulsion, expanded vermiculite powder, silane coupling agent modified feldspar tailing powder, a dispersing agent, an organic silicon defoaming agent, a polyurethane curing agent and deionized water. After being sintered, the green special refractory ceramic slurry provided by the invention has excellent high-temperature stability, corrosion resistance, thermal shock resistance and mechanical strength, and solves the problems of low high-temperature-resistant upper limit and poor corrosion resistance of the traditional slurry, so that the sintered ceramic adapts to severe high-temperature working conditions such as steel plant converter liners and chemical high-temperature reaction kettle inner walls; and long-term protection requirements of industrial equipment are met.

The invention relates to a slide ring of a mechanical seal assembly, comprising a sintered, ceramic ring (41) having a slide surface (4a), which ring is made of an electrically non-conductive ceramic material, a contact body (42), which is configured for electrical contact and is arranged in the ring (41), wherein the electrical contact body (42) is made of a sintered ceramic material which is electrically conductive, and wherein the electrical contact body (42) is arranged in an recess (40) in the ring (41) and fills the recess (40).

The invention discloses a preparation method of high-purity alumina electrostatic chuck ceramic, which belongs to the technical field of electrostatic chucks, and comprises the following steps: a) ball milling: mixing high-purity alumina powder with an organic binder, a dispersant and a solvent, and carrying out ball milling treatment; b) tape casting: spreading the aluminum oxide slurry on a tape casting machine through a tape casting process to form a ceramic film, and forming an aluminum oxide ceramic green body; c) preparing an electrode: preparing an electrode layer arranged in the ceramic; d) punching: reserving electrode through holes and holes required by other designs on the formed aluminum oxide ceramic body; e) laminating: laminating a plurality of layers of ceramic films to form a ceramic green body; f) glue discharging: placing the laminated ceramic green body in a glue discharging furnace for heating treatment; g) sintering: performing high-temperature sintering on the degummed ceramic green body; h) leveling: carrying out leveling treatment on the sintered ceramic to enable the surface of the ceramic to be flat; and i) hot isostatic pressing treatment: placing the leveled ceramic main body in hot isostatic pressing equipment.

The invention discloses a preparation method of low-temperature sintered ceramic. The preparation method comprises the following steps: S1, pretreating kaolin; s2, modifying kaolin; s3, preparing a ceramic green body; s4, preparing a glaze material; and S5, preparing the low-temperature sintered ceramic. According to the low-temperature sintered ceramic provided by the invention, the kaolin is pretreated and modified, and the special grinding aid is added in the preparation process of the ceramic green body, so that the sintering temperature of the ceramic is effectively reduced, the sintering process is optimized, low-temperature sintering of the ceramic is realized, the energy consumption is reduced, and the production efficiency is also improved; the method has remarkable economic benefits and environmental protection significance, and the prepared ceramic has good mechanical properties.

The invention discloses a low-temperature sintered microwave dielectric ceramic material and a preparation method thereof, and belongs to the technical field of electronic materials. The composite material comprises the following raw materials: CaCO3, SrCO3, Bi2O3 and B2O3. The preparation method comprises the following steps: burdening and weighing according to a stoichiometric ratio CaxSr1-xBi2B2O7 (x is more than 0.1 and less than 0.9), then carrying out ball milling and mixing, pre-sintering to obtain pre-sintered ceramic powder, adding an organic material to prepare stable slurry, carrying out tape casting to obtain a green body, and sintering to obtain the low-temperature sintered microwave dielectric ceramic material. The sintering temperature of the ceramic material is 700-800 DEG C, the dielectric constant range is 4-8, the loss value is less than 0.00002, and the ceramic material has low dielectric constant and ultrahigh quality factor. The problems that an existing low-temperature sintering microwave dielectric ceramic material is high in water absorption and high in material cost are solved. The microwave ceramic dielectric is applied to the technical field of electronic components requiring low dielectric constant and low loss value microwave ceramic dielectric.

A sintered ceramic having corrosion resistance to a halogen containing corrosive gas or plasma, the sintered ceramic is disclosed. The sintered ceramic is a mixed lanthanoid garnet phase aluminum oxide having a formula of (YpLnq)3Al5O12) wherein p plus q are less than or equal to 100 mole percent wherein p is greater than or equal to 25 mole percent and less than or equal to 75 mole percent and wherein is greater than or equal to 25 mole percent and less than or equal to 75 mole percent wherein Y is yttrium and Ln is a lanthanoid, such as erbium, ytterbium, lutetium and combinations thereof.

The invention discloses a preparation method of a high-volume-resistivity electrostatic chuck aluminum nitride ceramic plate, and belongs to the technical field of electrostatic chucks, the method comprises the following steps: raw material preparation: aluminum nitride powder, an oxide dopant and an organic additive are used as raw materials, the oxide dopant comprises 0.1-1 wt% of SiO2, 0.1-1 wt% of TiO2, 0.1-5 wt% of Y2O3, 0.1-2 wt% of CaO, 0.1-2 wt% of MgO and 0.1-2 wt% of BaO, the organic additive is added into the aluminum nitride powder, and the organic additive is added into the aluminum nitride powder; the organic additives comprise a solvent, a dispersing agent and a binder; the raw materials are subjected to mixing and ball milling for 4-8 h through a planetary ball mill, the ball milling rotating speed is 350-450 r / min, and the ball milling temperature is 25-30 DEG C; forming: forming by adopting a dry pressing forming method or a tape casting forming method; glue discharging: the highest temperature of glue discharging is 500-600 DEG C; sintering: adopting double-shaft pressurized nitrogen hot pressed sintering, keeping the highest temperature of the ceramic body at 1600-1800 DEG C for 2-8 hours, and keeping the pressure at 5-30 Mpa.

Proppant particles formed from slurry droplets and methods of use are disclosed herein. The proppant particles can include a sintered ceramic material and can have a size of about 80 mesh to about 10 mesh and an average largest pore size of less than about 20 microns. The methods of use can include injecting a hydraulic fluid into a subterranean formation at a rate and pressure sufficient to open a fracture therein and injecting a fluid containing a proppant particle into the fracture, the proppant particle including a sintered ceramic material, a size of about 80 mesh to about 10 mesh, and an average largest pore size of less than about 20 microns.

The invention relates to a particulate mixture intended to be used as an annealing agent; - consisting of sintered ceramic particles having a porosity greater than 20%; - having a chemical composition such that, in weight percentages on the basis of the oxides: Al2O3 + SiO2 > 70%, with SiO2 < 70% oxides other than SiO2 and Al2O3: making up the remainder to 100%; and - having a particle size distribution such that D90 < 5 millimeters and D10 > 0.5 millimeters, wherein D10 and D90 reprsent the particle sizes corresponding to the percentages that are equal to 10% and 90% by volume, respectively, on the particle size distribution curve of the particulate mixture, the particle sizes being classified in ascending order.

The invention relates to a particulate mixture intended to serve as an annealing agent, - consisting of sintered ceramic particles having a porosity greater than 20%, - having a chemical composition such that, in mass percentages on the basis of oxides: Al2O3 + SiO2 > 70%, with SiO2 < 70% oxides other than SiO2 and Al2O3: complement to 100%; and - having a particle size distribution such that D90 < 5 millimeters and D10 > 0.5 millimeters, D10 and D90 denoting the particle sizes corresponding to the percentages equal respectively to 10% and 90%, by volume, on the particle size distribution curve of the particulate mixture respectively, said particle sizes being classified in ascending order.

Disclosed is a pre-sintered ceramic block for a dental restoration, which has a low pre-sintering temperature, contains a silica main crystal phase, but does not contain or contains a small amount of lithium metasilicate crystal phase. The pre-sintered ceramic block has a low hardness, with a Vickers hardness of 0.5-3 GPa, which is significantly lower than that of a ceramic block containing a lithium metasilicate crystal phase, and same is suitable for dry machining and also wet machining when being machined into a dental restoration.

The invention discloses a high-durability multifunctional composite material for landscape architecture and a preparation method of the high-durability multifunctional composite material, and relates to the technical field of outdoor wood composite materials. Thermoplastic, plant fibers, a hydrophobic agent, a compatilizer and a composite antioxidant are blended to prepare a hydrophobic modified wood-plastic composite material, and the hydrophobic modified wood-plastic composite material is used as a core layer; the preparation method comprises the following steps: blending a wood unit, a low-temperature sintered ceramic precursor, nano titanium dioxide and an inorganic binder to prepare a photocatalyst-loaded microporous ceramic-wood composite material, and forming a functional surface layer of the photocatalyst-loaded microporous ceramic-wood composite material; according to the high-durability multifunctional composite material for the landscape architecture, synchronous co-extrusion is utilized, the surface of the core layer is coated with the functional surface layer, curing and shaping are conducted, and the high-durability multifunctional composite material for the landscape architecture is obtained and is a novel landscape material which integrates high durability, long service life, low maintenance, environment friendliness and aesthetic value and can actively keep the surface clean.

A method of manufacturing ceramic tape includes a step of directing a tape of partially-sintered ceramic into a furnace. The tape is partially-sintered such that grains of the ceramic are fused to one another yet the tape still includes at least 10% porosity by volume, where the porosity refers to volume of the tape unoccupied by the ceramic. The method further includes steps of conveying the tape through the furnace and further sintering the tape as the tape is conveyed through the furnace. The porosity of the tape decreases during the further sintering step.

The invention relates to a sintered ceramic body having a large size and a method for manufacturing the same. The method comprises the following process steps: providing a ceramic powder (5) within an internal volume of a spark plasma sintering tool (1), wherein the tool comprises: a mold (2); upper and lower punches (4, 4 ') creating a gap (3) between the punches and the inner wall when at least one of the punches moves within the internal volume; creating a vacuum condition within the interior volume; moving at least one of the punches to apply pressure to the ceramic powder while heating, and sintering; and reducing the temperature of the sintered ceramic body.

The invention provides a carbon ceramic vessel and a preparation method thereof.The preparation method of the carbon ceramic vessel comprises the steps that a ceramic body is subjected to first-time polishing treatment, and the polished ceramic body is obtained; carrying out sintering molding on the polished ceramic green body to obtain a sintered ceramic green body; carrying out liquid carburization and gas carburization on the sintered ceramic body to obtain a ceramic body of which at least part of pores contain a carbon film; and carrying out secondary polishing treatment on the ceramic green body containing the carbon film in at least part of pores to obtain the carbon ceramic vessel. According to the preparation method of the carbon ceramic vessel, through liquid carburization and gas carburization, a large number of carbon films can be formed in pores of the ceramic body, the water absorption rate of the ceramic body is greatly reduced, and the heat transfer performance is improved; and meanwhile, through two times of polishing treatment, the surface roughness and surface pores of the carbon ceramic ware can be reduced, and the carbon ceramic ware is glossy and better in appearance effect.

This invention discloses a selective roughening method for ceramic copper-clad laminates, comprising the following preparation steps: S1 printing an active solder layer between ceramic and copper foil; S2 preparing the ceramic copper-clad laminate; S3 etching copper onto the sintered ceramic copper-clad laminate; S4 removing unwanted solder layers; S5 cleaning, roughening, cleaning, acid washing, cleaning, immersion, and drying the patterned ceramic copper-clad laminate according to the following process, and filling it with nano-silicon and organosilane; S6 printing a thermosetting wet film to expose the area to be surface treated; S7 removing the surface roughening structure; S8 finally, subjecting the ceramic copper-clad laminate to nickel plating, chemical silvering, and then stripping to form the final structure. Compared with the prior art, this invention has the following beneficial effects: effectively avoiding the problem of solder voids caused by surface roughening pits, good surface weldability, and the concave structure of the welding area effectively prevents solder overflow during the welding process and reduces micropores in the chemical silver plating layer.

The invention provides a low-smoke halogen-free high-flame-retardant power cable and a preparation method thereof, and the low-smoke halogen-free high-flame-retardant power cable comprises a conductor, an insulating layer and a sheath layer. The sheath layer is prepared from the following raw materials: 25 to 40 parts of ethylene-vinyl acetate copolymer, 15 to 25 parts of linear low-density polyethylene, 5 to 15 parts of metallocene polyethylene, 8 to 15 parts of reactive phosphorus-nitrogen-silicon hybrid compatibilizer, 12 to 22 parts of low-temperature sintered ceramic composite powder, 30 to 45 parts of surface-treated magnesium hydroxide, 15 to 25 parts of surface-treated aluminum hydroxide, 3 to 6 parts of organic modified montmorillonite and 1.5 to 2.5 parts of triallyl isocyanurate. 1.0 to 2.0 parts of a composite antioxidant, 1.0 to 2.5 parts of a calcium-zinc stabilizer and 0.5 to 1.5 parts of silicone master batch. The prepared low-smoke halogen-free high-flame-retardant power cable has excellent flexibility, mechanical property, heat resistance and processability, is stable in flame retardant property and stable in size, and is suitable for safety protection of power cables.

The invention relates to a preparation method of conductive ceramic Mg3Ga2GeO8 for an all-solid-state battery, and belongs to the technical field of all-solid-state batteries. The preparation method mainly comprises the following steps: roasting MgO, Ga2O3 and GeO2 powder in an air atmosphere, adding a solvent, and drying after ball milling; adding the primary sintered ceramic wafer and a binder into a solvent, grinding, drying, tabletting, and carrying out air burning at 1200-1400 DEG C to obtain a primary sintered ceramic wafer; and crushing and grinding the primarily sintered ceramic chip, taking powder, and repeatedly sintering for 2-3 times to obtain the Mg3Ga2GeO8 ceramic chip with a compact structure and a single phase. The ionic conductivity of the prepared ionic conductive oxide Mg3Ga2GeO8 is high, the ionic conductivity reaches 10 <-5 > S / cm at 25 DEG C, the activation energy is as low as 0.80 eV, the process is simple, and the method is suitable for industrial production.

The invention relates to a method for preparing an aluminum oxide ceramic substrate through gel casting by using a three-stage drying method, which effectively reduces capillary force in a water evaporation process through replacement drying of polyethylene glycol, relieves the problem of rapid shrinkage of the surface of a green body, and avoids the phenomenon of internal high stress concentration through uniform diffusion of a replacement solution; in the microwave drying stage, synchronous migration of moisture inside and outside the green body is achieved through temperature control adjustment, the dry shell effect is avoided, finally hot air drying is carried out, and the compactness and dimensional precision of the finally sintered ceramic substrate are further improved. And the replacement drying and the microwave drying are combined, so that the moisture removal rate is obviously increased. Compared with a traditional natural drying mode or a single hot air drying mode, the whole drying time of the process is shortened by 30% or above. Through a scientifically designed three-stage drying process, the problems of cracks, deformation, low drying efficiency and the like in the preparation of the gel-casting aluminum oxide ceramic substrate are comprehensively solved, and the yield and the performance of the substrate are remarkably improved.

The utility model relates to the technical field of vacuum arc extinguish chambers, in particular to a vacuum arc extinguish chamber shielding cylinder fixing structure which comprises a shell, a shielding cylinder and a plurality of movable parts, the shell is provided with a vacuum cavity, the cavity wall of the vacuum cavity is provided with a first protruding part, and the side wall of the shielding cylinder is provided with a second protruding part. The second protruding part abuts against one end of the first protruding part, and each movable part is in threaded connection with the shielding cylinder, extends out of the outer side wall of the shielding cylinder by a preset distance and abuts against the other end of the first protruding part. And the movable piece abuts against the first protruding part, so that the protrusion with the adjustable extending length is achieved, and the shielding cylinder is prevented from shaking and making abnormal sounds.

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.

This utility model discloses a demolding device for a pressing mold, including a pressure screw, a hollow demolding screw, and a screw support. The screw support includes a base, on which a hollow demolding screw support nut bracket and a pressure screw support nut bracket are fixedly installed. The hollow demolding screw is threadedly connected to the nut hole on the hollow demolding screw support nut bracket, and a pressure screw is threadedly connected to the nut hole on the pressure screw support nut bracket. A cylindrical cavity is formed in the center of the hollow demolding screw, through which the pressure screw passes. This demolding device for a pressing mold significantly reduces cracking damage to the ceramic blank after demolding. It has good demolding effects for both experiments with and without adhesive powder. The demolded blanks have high consistency and few defects, providing accurate and reliable performance evaluation of the sintered ceramic powder. Furthermore, it greatly improves the demolding success rate, efficiently obtaining high-quality blanks.

A method for enhancing mechanical properties of sintered, zirconia ceramic bodies and zirconia ceramic dental restorations is provided. A porous or pre-sintered stage of a ceramic body may be treated with a tantalum-containing composition prior to sintering. Alternatively, zirconia ceramic powder may be coated with a tantalum-containing composition prior to forming a shaped ceramic body. After sintering, the resulting ceramic bodies have enhanced mechanical properties, such as greater fracture toughness, without a significant decrease in optical properties.