19results about How to "Improve sintered density" patented technology

The invention discloses a low-loss manganese-zinc soft magnetic ferrite material suitable for wide frequency and wide temperature and a preparation method thereof, the material comprises the following main components in percentage by mass: 71.25%-71.5% of Fe2O3, 6.0%-7.5% of ZnO and the balance of MnO; the additive is prepared from the following components in percentage by mass: 0.4 percent to 0.5 percent of Co3O4 and 0.07 percent to 0.11 percent of SnO2; the raw materials comprise, by weight, 0.004%-0.008% of SiO2, 0.03%-0.04% of CaCO3 and 0.01%-0.02% of ZrO2; and 0.02% to 0.03% of Nb2O5. According to the present invention, the main component raw materials are subjected to pre-sintering, coarse crushing, sand grinding and fine crushing after the additive is added, spray granulation, and sintering in the nitrogen and oxygen mixed atmosphere, such that the wide frequency, wide temperature and low loss of the manganese zinc ferrite material are achieved, and the application prospect is good when the manganese zinc ferrite material is used for the low-loss electronic transformer.

The invention discloses a preparation method of a high-purity corundum crucible for high-temperature alloy smelting, belongs to the technical field of precision casting refractory material forming preparation, and aims to solve the problems that an Al2O3 crucible is easily eroded by high-temperature alloy, impurities are generated during high-temperature alloy smelting, and the Al2O3 crucible is difficult to be suitable for high-temperature alloy smelting. According to the technical key points, 60%-70% by mass of aluminum oxide Al2O3 powder and 30%-40% by mass of silicon oxide SiO2 powder are added into a ball milling tank to be subjected to ball milling treatment, the aluminum oxide Al2O3 powder comprises fine powder mixed powder with the particle size being 5-50 micrometers, medium powder mixed powder with the particle size being 50-300 micrometers and coarse powder mixed powder with the particle size being 0.4-0.5 mm, and the coarse powder mixed powder is mixed with the medium powder mixed powder with the particle size being 2-5 micrometers. A binder polyvinyl alcohol (PVA) solution is added into the mixed powder for granulation operation, after the mixed material is aged, the mixed material is pressed in a cold isostatic pressing mode, a crucible preformed blank is obtained and sintered at different temperatures after being dried, and the crucible is obtained. The method has the effect that the sintered high-purity corundum crucible has excellent high temperature resistance and thermal stability at the same time.

The invention provides a preparation method of pressureless sintered boron nitride composite ceramic, and relates to the technical field of ceramic composite material preparation. The method comprises the following steps: carrying out surface modification on boron nitride whiskers by using ethanolamine, and activating hexagonal boron nitride powder in a ball milling tank by using an alkaline solution; the preparation method comprises the following steps: uniformly mixing the boron nitride powder and the boron nitride powder in a mixing tank, carrying out cold isostatic pressing to obtain a cold-pressed green body, and carrying out high-temperature calcination on the cold-pressed green body in an inert atmosphere to finally obtain the boron nitride composite ceramic. According to the invention, the physical property characteristics of the boron nitride whisker are fully utilized, and the boron nitride whisker can be fully combined with the hexagonal boron nitride powder subjected to surface activation during calcination through further chemical surface modification, so that relatively high mechanical strength can be realized only by using one phase of boron nitride on the premise of not introducing other sintering aids; the method has the characteristics of high product purity, low production cost and high mechanical strength.

The invention discloses a powder metallurgy brake lining material, a preparation method and a brake lining, the powder metallurgy brake lining material is obtained by sintering powder, and the powder metallurgy brake lining material comprises the following raw materials in parts by mass: 67-70 parts of electrolytic copper powder; 12 to 17 parts of iron powder; 5-9 parts of tungsten; 12 to 18 parts of flaky graphite; 7-9 parts of molybdenum disulfide; 5-8 parts of zirconium dioxide; 7 to 11 parts of nano silicon dioxide; the interface metallographic phase of a sintered body is improved, the combinability of all components in the powder metallurgy brake pad material is enhanced, the deformation resistance of the powder metallurgy brake pad material at high temperature is provided for the powder metallurgy brake pad material, and when a high-speed train brakes and the temperature of the brake pad is rapidly increased, all the components in the powder metallurgy brake pad material are tightly combined and are not prone to disengagement; and heat fading of friction performance of the powder metallurgy brake lining material is inhibited, so that excellent friction performance and low abrasion loss of the brake lining under high-speed braking are guaranteed.

The invention discloses a modified ATO ceramic target material and a preparation method thereof. The modified ATO ceramic target material comprises the following raw material components in parts by weight: 89-98 parts of tin oxide, 1-10 parts of antimony oxide and 1-3 parts of doped oxide, and the doped oxide is at least one of ZnO, Bi2O3, TiO2 and Ta2O5. The specific metal oxide is adopted to perform doping modification on the ATO ceramic target material, the sintering atmosphere and the sintering temperature system are controlled, and the characteristics of the doped oxide and the interaction between the doped oxide and SnO2 are utilized, so that the sintering density of the target material is improved, pores of grain boundaries are eliminated, and the target material is prepared. And the conductivity of the target material and the stability of the target material in the magnetron sputtering process are further improved. The relative density of the modified ATO ceramic target material is larger than or equal to 97.8% and even can reach 99.2%; and the resistivity is less than or equal to 5.2 * 10 <-3 > omega.cm and even can reach 3.8 * 10 <-3 > omega.cm.

The invention relates to a manganese zinc ferrite composite material as well as an internal mixing method and application thereof. The manganese zinc ferrite composite material comprises manganese zinc ferrite powder and an additive, the additives comprise a framework material, a binder, a lubricant and an antioxidant; the average particle size D50 of the manganese zinc ferrite powder is 0.95 [mu] m to 1.75 [mu] m. According to the invention, the additive comprising the framework material, the binder, the lubricant and the antioxidant is mixed with the manganese-zinc ferrite powder with the average particle size D50 of 0.95-1.75 [mu] m, and the manganese-zinc ferrite powder with the particle size can be uniformly dispersed in the manganese-zinc ferrite composite material under the combined action of the framework material, the binder, the lubricant and the antioxidant; and therefore, the uniform consistency of internal mixing is guaranteed, the problem that internal mixing is difficult due to the fact that the manganese zinc ferrite powder is small in particle size is solved, the quality of soft magnetic material injection molding products is improved, large-scale production is promoted, and the requirement of the market for high-performance soft magnetic materials is met.

This invention discloses a black-based blue-spotted glaze with an earthworm-like pattern and its preparation method. The glaze consists of a body, a black base glaze, and a blue-spotted glaze from the inside out. The raw materials for the black base glaze are: feldspar, calcite, calcium borate, dolomite, talc, barium carbonate, quartz, bentonite, zirconium silicate, rutile, cobalt oxide, manganese oxide, and iron oxide. The raw materials for the blue-spotted glaze are: feldspar, limestone, alumina, talc, barium sulfate, Datong clay, zinc oxide, quartz, and titanium dioxide. The preparation method includes: 1. Wet ball milling the black base glaze raw materials to obtain a black base glaze slurry; 2. Wet ball milling the blue-spotted glaze raw materials to obtain a blue-spotted glaze slurry; 3. Bisque firing the body; 4. Applying the black base glaze slurry to the body and drying it; 5. Applying the blue-spotted glaze slurry to the body and drying it; 6. Oxidation firing and reduction firing of the body, followed by natural cooling to obtain the black-based blue-spotted glaze. The raw material formula of this invention is reasonable and environmentally friendly, which can improve the mechanical properties of the glaze; the preparation method is simple and the yield is high.

The invention discloses a photocuring forming preparation method of high-strength fused quartz ceramic, and belongs to the technical field of photocuring forming. Comprising the following steps: blending fused quartz powder with a modifier I and a modifier II to prepare mixed powder, performing wet grinding, drying and sieving to obtain modified fused quartz powder; mixing the prepolymer I, the prepolymer II, a resin monomer I, a resin monomer II, a photoinitiator I and a photoinitiator II to prepare a photosensitive resin system; adding a dispersing agent into the photosensitive resin system, uniformly mixing, then adding the modified fused quartz powder and SiC powder, and uniformly mixing, so as to prepare fused quartz ceramic photocuring slurry; carrying out printing forming, degreasing treatment and sintering on the fused quartz ceramic photocuring slurry to obtain fused quartz ceramic; the use amount of the SiC powder is 1wt%-5wt% of the mass of the modified fused quartz powder. The preparation method can reduce the curing depth of the fused quartz, improve the forming precision and improve the sintering density of the fused quartz.

This invention discloses a high thermal conductivity semiconductor packaging substrate and its preparation method, relating to the field of electronic materials technology. The method includes the following steps: mixing composite aluminum nitride powder with a sintering aid, ball milling, drying, and pressing into shape; sintering under high temperature and high pressure in a nitrogen atmosphere to obtain an aluminum nitride ceramic substrate; washing and drying the aluminum nitride ceramic substrate; covering both sides of the aluminum nitride ceramic substrate with copper foil, laying active solder between the aluminum nitride ceramic substrate and the copper foil, and then connecting them by vacuum brazing to obtain the semiconductor packaging substrate; the composite aluminum nitride powder is composed of aluminum nitride powder and modified aluminum nitride powder in a mass ratio of (6~8):(2~4). The semiconductor packaging substrate prepared by this method has excellent interfacial compatibility, effectively reduces interfacial thermal stress, and has good thermal conductivity.

The invention relates to the technical field of rock wool furnaces, in particular to a low-chromium aluminum-chromium refractory material for a rock wool furnace lining and a preparation method of the low-chromium aluminum-chromium refractory material. The preparation method comprises the following steps: S1, stirring and mixing corundum particles and fused zirconium mullite particles to obtain a premixed particle material; s2, the corundum fine powder, the chromium concentrate fine powder, the andalusite fine powder and the zirconite fine powder are mixed and ground together until the particle size is smaller than or equal to 65 micrometers, and premixed fine powder is obtained; s3, mixing the premixed granular material and the premixed fine powder material to obtain a premixed material; s4, sequentially adding Si powder and aluminum silicate fibers into the premix, and mixing to obtain a mixture; s5, adding a phosphoric acid solution into the mixture, stirring and mixing, adding into a mold for vibration molding, naturally curing, and drying to obtain a green material; and S6, the green body material is subjected to high-temperature heat preservation for a period of time. The refractory material prepared by the invention is environment-friendly, high in sintering density, good in thermal shock resistance, small in thermal expansion coefficient and strong in erosion resistance.

The invention belongs to the technical field of ferrite materials, and provides an ultrahigh-Bs, wide-temperature, high-flux and low-loss material which comprises main components and auxiliary components, the main components comprise, by mole, 65-67 mol% of Fe2O3, 28-30 mol% of Mn3O4, 10-12 mol% of ZnO and 0.5-0.7 mol% of NiO, and the total proportion of the main components is 100 mol%; the auxiliary components comprise CaCO3, SnO2, Bi2O3, SiO2, TiO2, ZrO2, Ta2O5, V2O5, CuO and C2H4O, and the auxiliary components comprise CaCO3, SnO2, Bi2O3, SiO2, TiO2, ZrO2, Ta2O5, the ultrahigh-Bs, wide-temperature, high-flux and low-loss material and the sintering method thereof are researched and developed, the effects of high sintering density and better Bs characteristics are achieved, the energy efficiency is improved within the wide-temperature range, and miniaturization is achieved.

The invention relates to the technical field of aluminum-based composite material preparation, in particular to a ceramic reinforced aluminum-based workpiece and a preparation method. The ceramic reinforced aluminum-based workpiece is prepared by the method. The method comprises the steps that a forming die is assembled and filled with aluminum-based composite powder; sintering the forming die filled with the aluminum-based composite powder in an inert atmosphere to obtain a sintered green body; performing die forging treatment on the sintered green body to obtain a prefabricated green body; and after the prefabricated blank is machined to the size of a finished product, the prefabricated blank is sequentially subjected to solution treatment and aging treatment, and the ceramic reinforced aluminum-based workpiece is obtained. By means of the method, the ceramic reinforced aluminum-based workpiece with the large length-diameter ratio can be prepared, and the problems that cracks are generated when a formed blank is not separated from the female die, and layering and fragmentation are generated in the demolding process are solved.

The invention discloses a titanium alloy. The titanium alloy is obtained by injection molding of titanium alloy powder. The titanium alloy powder comprises a titanium alloy ball, a TiB2 layer, a polyamine layer and a graphene oxide layer, the surface of the titanium alloy ball is sequentially coated with the TiB2 layer, the polyamine layer and the graphene oxide layer, and the graphene oxide layer contains cerium. The invention also discloses a preparation method of the titanium alloy, which comprises the following steps: mixing titanium alloy powder with a binder, carrying out injection molding, degreasing, carrying out vacuum sintering at 1000-1100 DEG C for 2-3 hours, cooling to room temperature, carrying out solid solution at 700-720 DEG C for 40-60 minutes, carrying out air cooling to room temperature, carrying out heat preservation at 450-470 DEG C for 3-3.5 hours, and then carrying out air cooling to room temperature to obtain the titanium alloy. The titanium alloy disclosed by the invention keeps good toughness while having good strength.

The invention discloses a method for preparing a Zr3Si2 material based on electric arc melting, crushing and sintering, and relates to the technical field of zirconium alloy preparation. The preparation method comprises the following steps: firstly, synthesizing a Zr3Si2 material through an electric arc melting method liquid phase reaction, then, carrying out mechanical crushing and ball milling to obtain powder, and finally, carrying out powder densification sintering by using spark plasma sintering, thereby obtaining the Zr3Si2 / Zr3Si2 composite material. The electric arc melting technology is used for providing a high-temperature environment, reactants can be completely molten, molten silicon and zirconium are fully diffused and react, and it is ensured that the product purity is high. And rapid smelting and rapid cooling are achieved through electric arc smelting, the phenomenon of grain growth can be avoided, and a uniform microstructure is formed. Only silicon and zirconium are used as raw materials, no other substances participate in the reaction, the raw materials are pure, the reaction is carried out through a liquid phase, the raw materials are fully mixed, generation of other zirconium-silicon intermetallic compounds is reduced, Zr3Si2 obtained through the reaction is high in purity, and introduction of impurities is reduced to a great extent.

The application relates to the technical field of soft magnetic ferrite materials, and discloses a soft magnetic ferrite core with high power density and low loss and an application, wherein the soft magnetic ferrite core is prepared from 70%-73% of main material A, 22%-23% of main material B, 3%-7% of main material C, 0.15%-0.65% of auxiliary material D and 0.08%-0.30% of auxiliary material F; the double auxiliary material system of the auxiliary material D and the auxiliary material F is constructed to improve the grain boundary resistivity, refine the grain size, reduce the sintering temperature and simultaneously realize ultra-low power loss; the whole-process fine process control of step-by-step sand milling, subcritical pre-sintering, secondary submicron sand milling, spray granulation and segmented balanced atmosphere sintering is adopted to obtain a microstructure soft magnetic ferrite core with concentrated particle size, small and uniform spinel phase grain, high sintering density and balanced Fe 2+ / Fe 3+ proportion, so that the soft magnetic ferrite core is successfully applied to the on-board charger and DC-DC converter of a new energy vehicle, a photovoltaic inverter and a 5G communication power supply field.

The invention discloses a preparation method of chopped carbon fiber reinforced SiC ceramic, and relates to the technical field of novel materials. By adjusting the introduction mode of the ceramic additive, ceramic sintering densification is greatly influenced, boron modified phenolic resin is adopted as the modified phenolic resin, boron can selectively segregate at the silicon carbide grain boundary, the grain boundary energy is reduced, the ratio of the grain boundary energy to surface energy is reduced, and sintering is promoted; meanwhile, the boron element can be dissolved in silicon carbide crystal lattices to generate lattice defects, so that the diffusion coefficient is increased, and the sintering compactness of the ceramic is promoted; carbon can reduce an oxide layer on the surface of the silicon carbide micro-powder, improve the surface energy of the micro-powder and improve the sintering driving force; the modified phenolic resin realizes dispersion of boron and carbon at a molecular level, so that the boron and the carbon can uniformly coat the surfaces of the carbon fibers and the silicon carbide micro powder, the sintering promotion effect of the boron and the carbon is effectively exerted, air holes in the ceramic are favorably removed, and the sintering density of the ceramic is improved.

The application discloses a kind of titanium alloys, the titanium alloy is obtained by titanium alloy powder injection molding;Wherein, the titanium alloy powder includes: titanium alloy ball and TiB2 layer, polyamine layer, graphene oxide layer successively coated on the surface of titanium alloy ball, and the graphene oxide layer contains cerium element.The application also discloses a preparation method of the above-mentioned titanium alloy, comprising the following steps: taking titanium alloy powder and binder mixing, injection molding, degreasing, vacuum sintering at 1000-1100 DEG C for 2-3h, cooling to room temperature, solid solution at 700-720 DEG C for 40-60min, air cooling to room temperature, then heat preservation at 450-470 DEG C for 3-3.5h, and then air cooling to room temperature, to obtain titanium alloy.The titanium alloy has good strength while maintaining good toughness.

The application discloses a manganese-zinc ferrite and a preparation method thereof, and the method comprises the following steps: mixing manganese-zinc ferrite powder and a polyvinyl alcohol solution to obtain a mixture, and grinding the mixture; performing a compression molding treatment on the ground mixture to obtain a compression molding product; and performing a sintering treatment on the compression molding product to obtain the manganese-zinc ferrite; wherein the sintering treatment comprises a temperature rising treatment stage, and the temperature rising treatment stage comprises a plurality of temperature rising stages, at least two of which have different temperature rising rates. The manganese-zinc ferrite prepared by the application can have a high saturation magnetic flux density and a low residual magnetism while keeping a low loss at a high frequency, that is, the manganese-zinc ferrite with a large magnetic induction intensity change amount is prepared.

This invention discloses a low-glass phase exudation zirconium corundum brick and its preparation method, belonging to the field of refractory material technology. It employs a core-shell dopant as a sintering aid. The core-shell dopant has a core-shell structure with flower-shaped nano-titanium dioxide as the core and calcium oxide as the shell. At high temperatures, the flower-shaped nano-titanium dioxide reacts with calcium oxide to form CaTiO3, which resides in the grain boundary pores, reducing the concentration of calcium oxide. CaTiO3 is less prone to hydration, preventing calcium ions from reacting with water vapor in the air to form calcium hydroxide, thus eliminating the volume expansion caused by hydration. The flower-shaped nano-titanium dioxide of this invention possesses a large specific surface area and a flower-shaped structure, enabling it to exert a template effect and guide the CaAl... 12 O 19 Lamellar crystals grow in a directional manner to avoid disordered growth, CaAl 12 O 19 Lamellar crystals can synergistically improve the mechanical strength and toughness of zirconium corundum bricks through crack deflection and bridging.