110results about How to "Good sphericity" patented technology

The invention provides a preparation method of an isotropic Ti2AlNb / TiAl-based interpenetrating composite material, and belongs to the technical field of intermetallic compound-based composite materials. The method comprises the following steps: firstly, designing a Ti2AlNb reinforcement framework of various TPMS configurations by utilizing implicit function modeling; then, carrying out anisotropy research on the TPMS configuration by utilizing finite element simulation; secondly, a Ti2AlNb reinforcement framework of a TPMS configuration is prepared through a selective laser melting (SLM) technology; and finally, the TPMS configuration Ti2AlNb / TiAl-based interpenetrating composite material is prepared through vacuum hot pressing sintering of HPS. Therefore, strong anisotropy of a traditional fiber reinforced composite material in mechanical property is avoided, good matching of strength, plasticity and toughness of the composite material is achieved, and a new thought and a new solution are provided for breaking through the application bottleneck of TiAl in spaceflight power system hot end components.

The invention relates to the technical field of battery materials, in particular to a ternary precursor, a preparation method thereof and a ternary positive electrode material. The preparation method of the ternary precursor comprises the following steps: preparing a mixed metal salt solution containing a nickel source, a cobalt source and a manganese source; the mixed metal salt solution, alkali liquor and a complexing agent are added into the base solution for a coprecipitation reaction, and the coprecipitation reaction comprises the steps that a nucleation reaction is conducted when the pH value of a reaction system ranges from 12 to 13, and then the pH value is gradually reduced to 11 or above along with the growth reaction till product particles reach the target particle size, in the process of gradually reducing the pH value to 11 or above, at least two times of pH value constant time exist, and the pH value constant time of one time is 40 hours or above; and carrying out solid-liquid separation on the product after the coprecipitation reaction is finished to obtain the ternary precursor. According to the preparation method, the ternary precursor material which is narrow in span distribution, small in particle and stable can be obtained.

The invention belongs to the technical field of powder metallurgy, and discloses a novel double-circular-seam atomizer and an atomizing device.The novel double-circular-seam atomizer comprises an atomizer base body, a vertically-through melt channel is formed in the middle of the atomizer base body and used for allowing a flow guide nozzle to penetrate through, and the atomizer base body is provided with a cavity coaxial with the melt channel and a circular-seam spraying hole; the cavity is used for inputting high-pressure gas, and the circular seam spraying hole communicates with the cavity and is used for spraying out the high-pressure gas to form high-speed gas flow so as to break metal melt liquid flow flowing out of the flow guide nozzle. The number of the circular seam spraying holes is two, the two circular seam spraying holes are the first circular seam spraying hole and the second circular seam spraying hole, the second circular seam spraying hole surrounds the first circular seam spraying hole from the outer side of the first circular seam spraying hole, and on any longitudinal section plane of the atomizer base body, the jet flow center lines of the second circular seam spraying hole and the first circular seam spraying hole intersect at one point; the melt liquid flow crushing effect can be improved, the diffusion angle of metal liquid drops is increased, formation of large particles is reduced, and metal powder with smaller particle size and better sphericity degree is obtained.

The invention discloses a method for preparing high-purity uranium carbide microspheres by a microfluidic-assisted internal gelation process, which comprises the following steps of: designing a uranium glue solution component containing carbon black to obtain a uranium glue solution which is stable for a long time at room temperature and quickly gelates at high temperature; the preparation method comprises the following steps: preparing gel microspheres with uniform size by using a uranium glue solution as a micro-fluidic dispersion phase through a micro-fluidic assisted inner gel process; the pore structure in the gel microspheres is maintained through washing and soaking with propylene glycol monomethyl ether, so that the crack-free gel microspheres are obtained; the UC nuclear fuel microspheres which are uniform in size, good in sphericity degree and high in phase purity are prepared through the carbon thermal reduction reaction of the non-cracking gel microspheres under the optimized sintering schedule, and development of ultrahigh-temperature gas cooled reactor nuclear fuel is expected to be promoted.

The invention discloses a circumferential air inlet gas spiral-flow type atomizing nozzle, and aims to solve the problems of disordered air flow distribution and unbalanced pressure in a gas storage cavity of an existing atomizing nozzle so as to improve the atomizing efficiency and the powder quality. Comprising an upper cover, an air inlet disc and a base, the upper cover and the air inlet disc are matched to form an air inlet cavity for circumferential air inlet and a circular seam outlet, an air inlet channel is arranged in the circumferential direction of the air inlet cavity, and three guide blades are arranged at the lower end of the upper cover at equal angles and used for guiding the airflow direction; in addition, a metal liquid flow channel is formed in the center of the upper cover, and a base groove is used for containing an air inlet pipe and fixing a nozzle. By arranging the circumferential air inlet channel and the guide vanes, gas flows in a vortex shape, the mixing efficiency is improved, vortexes and dead zones are reduced, pressure balance in the cavity is achieved, rotating airflow with high impact force is formed, and the atomization effect is optimized; by improving the structural design of the atomizing nozzle, the particle size uniformity and sphericity degree of atomized powder are remarkably improved, satellite powder is reduced, and the powder yield and the powder quality are improved.

The invention provides a method for preparing a catalyst and the catalyst prepared by the method. The method comprises the following steps: immersing alkoxy magnesium particles in molten paraffin, raising the temperature to 70-120 DEG C, and fully stirring to enable pores of the particles to be filled with the paraffin; filtering the mixture of the paraffin and the particles, cooling a filter cake to 0-40 DEG C, and removing the paraffin on the surfaces of the particles; flattening the surfaces of the particles by using a chlorinated silane compound to generate a product mixture; filtering and washing the product mixture to obtain flattened particles; removing paraffin in pores of the flattened particles to obtain porous flattened particles; and adding the porous flattened particles into a titanium compound at a temperature of-20 to 110 DEG C, and reacting to obtain the catalyst. By applying the technical scheme provided by the invention, the problems that the particle size of the catalyst is difficult to control and the catalyst is easy to break in the prior art can be solved, and the prepared small-particle-size catalyst has excellent sphericity and can retain the pore structure of original particles.

The invention belongs to the technical field of material preparation, and discloses high-crystallinity spherical silicon carbide powder and a preparation method and application thereof.The method comprises the steps that tetraethyl silicate and 4-phenylbutyltrimethoxysilane are dissolved in absolute ethyl alcohol, a catalyst is added, and a uniform mixed solution is obtained after stirring; heating the mixed solution in a water bath at 25-35 DEG C, stirring and dropwise adding ammonia water, stopping dropwise adding ammonia water when the mixed solution becomes milk white, heating in a water bath at 50-60 DEG C, and centrifuging and washing the obtained product to obtain a spherical silicon-carbon mixture; and sintering the mixture at 1500-1600 DEG C in a protective atmosphere, and grinding to obtain the high-crystallization spherical silicon carbide powder with the average particle size of 2.6-5.5 microns and the crystallinity of 92% or above. The spherical silicon carbide powder disclosed by the invention has the advantages of easily available raw materials, simple process, high crystallinity and excellent comprehensive performance, and can be widely applied to the fields of electronics and photoelectricity.

The invention relates to the field of thermal spraying ceramic coatings, and particularly discloses plasma spraying ceramic powder, a ceramic composite coating and a preparation method of the ceramic composite coating. The plasma spraying ceramic powder is prepared from the following raw materials in parts by weight: 100 parts of nano powder and 10 to 30 parts of silicate glass powder, the nano powder comprises nano Al2O3 powder, nano TiO2 powder, nano CeO2 powder and nano YSZ (Yttria Stabilized Zirconia) powder in a weight ratio of (80-86): 10: 2: (2-8). The plasma spraying ceramic powder has the beneficial effects of being good in fluidity, smooth in surface, high in compactness and good in sphericity degree, and the prepared ceramic composite coating has the beneficial effects of being low in porosity, high in compactness, good in corrosion resistance and long in service life.

The invention provides a polycaprolactone microsphere as well as an interfacial membrane emulsification preparation method and application thereof, and the interfacial membrane emulsification preparation method comprises the following steps: firstly, respectively preparing a dispersion phase containing polycaprolactone and a continuous phase containing a surfactant, and then centrifugally mixing the dispersion phase containing polycaprolactone and the continuous phase containing the surfactant in a planetary centrifugal emulsifying machine to form emulsion droplets; and finally, stirring the emulsion droplets to volatilize the organic solvent, washing with water, centrifuging and drying to obtain the polycaprolactone microspheres. The interfacial membrane emulsification preparation method is simple in process, convenient to operate and short in consumed time, and meanwhile, the prepared polycaprolactone microspheres are very uniform in particle size distribution, relatively narrow in particle size distribution, good in sphericity and good in application prospect, and the appearance of the polycaprolactone microspheres is of a spherical structure.

The embodiment of the invention provides a preparation method of a tungsten-copper alloy and the tungsten-copper alloy, and relates to the technical field of alloy preparation.The method comprises the steps that superfine tungsten oxide powder, tungsten salt, copper salt and a polymer additive are added into deionized water to be evenly mixed, and a precursor mixed solution is obtained; carrying out spray granulation on the precursor mixed solution by adopting a spray dryer to obtain spherical tungsten-copper precursor composite powder; roasting the spherical tungsten-copper precursor composite powder to obtain tungsten-copper oxide composite powder, and carrying out segmented reduction on the tungsten-copper oxide composite powder to obtain tungsten-copper composite powder with tungsten grains having a nanocrystalline / ultra-fine grain bimodal distribution characteristic; and the tungsten-copper composite powder is pressed to obtain an alloy blank, the alloy blank is sintered, and the tungsten-copper alloy is prepared. According to the double-peak distribution tungsten-copper composite powder, full densification of the alloy can be promoted through coupling rearrangement of large and small tungsten particles in the sintering process, and the compactness, the heat conductivity and the electric conductivity of the tungsten-copper alloy can be improved.

The invention belongs to the technical field of lithium ion battery materials, and particularly discloses an in-situ doped and coated lithium iron phosphate material as well as a preparation method and application thereof. The lithium iron phosphate material comprises an in-situ carbon coating layer and a lithium iron phosphate core doped with high-valence metal cations in situ, the chemical general formula of the lithium iron phosphate material is LiFe1-xMxPO4 (at) C, x is more than or equal to 0.003 and less than or equal to 0.007, and M comprises at least one of Nb, V, Ti or Y. The lithium iron phosphate material has the advantages of favorable crystallinity, favorable sphericity, uniform distribution of large and small particles, excellent electrochemical properties, high compaction density and low powder resistivity of the material powder, and has high specific discharge capacity and cycle capacity retention ratio when being used as the positive electrode material of the lithium ion battery. The invention also provides a preparation method and application of the lithium iron phosphate material.

The invention discloses a method for preparing a manganese sulfate crystal by using manganese carbonate ore. The preparation method of the manganese sulfate crystal comprises the following steps: leaching manganese carbonate ore by using sulfuric acid to obtain a leaching solution, precipitating the leaching solution by using a heavy removing agent to remove heavy metal ions, neutralizing redundant sulfuric acid in the leaching solution, introducing a precipitating agent, reacting with the precipitating agent to obtain a precipitate, washing the precipitate with water to remove impurities, and dissolving by using sulfuric acid to obtain the manganese sulfate crystal. And after dissolving, precipitating a small amount of residual calcium and magnesium ions by using fluoride, filtering to obtain fluorine-containing manganese sulfate filtrate, finally adding a fluorine removal agent for solid-liquid separation, and evaporating and crystallizing the filtrate to obtain manganese sulfate crystals. The manganese sulfate crystal is suitable for production of a lithium ion battery positive electrode material. According to the preparation method of the manganese sulfate crystal, the impurity removal cost is greatly reduced. The invention also discloses a method for preparing manganous-manganic oxide from manganese carbonate ore. The tap density of the manganous-manganic oxide is greater than 2.3 g / cm < 3 >, the specific surface area is less than 3m < 2 > / g, and the requirement of a battery-grade material is met.

The invention belongs to the technical field of additive manufacturing of metal-based composite materials, and particularly relates to a preparation method of carbon nanotube coated functional titanium alloy composite powder. The preparation method comprises the following steps: by taking spherical alloy powder of titanium alloy with special functions of hydrogen storage, shape memory, super elasticity, high damping, high biocompatibility and the like as a matrix, growing carbon nanotubes on the surface of the powder in situ to obtain a composite powder raw material for the 3D printing titanium-based composite material; the composite powder has the advantages of high sphericity, good fluidity, low impurity content, uniform distribution of the carbon nanotubes on the surface of the powder, controllable content and the like. The method is realized through a fluidized bed technology, and has the advantages of simple process, low cost, short flow, easy realization of large-scale production and the like.

The invention provides a preparation method of micro low-oxygen spherical TiAl alloy powder, and relates to the technical field of spherical titanium-based alloy powder. The preparation method comprises the steps of raw material selection and treatment of a wire material, preparation of a TiAl composite wire, preparation of a TiAl alloy wire, treatment of the TiAl alloy wire, establishment of a gas system, high-frequency induction preheating, radio frequency plasma smelting and atomization powder preparation which are sequentially carried out. According to the method, through multiple wire twisting, multiple continuous hot drawing, diffusion homogenization annealing, high-frequency induction preheating, radio frequency plasma smelting and atomization powder preparation, the TiAl alloy wire with the evenly-distributed components can be directly prepared at the low temperature, then the TiAl alloy fine powder with the low oxygen content and the evenly-distributed components is prepared, the TiAl alloy fine powder is suitable for additive manufacturing, and the method is suitable for being used for additive manufacturing. The method is high in flexibility, simple to operate, wide in application, low in cost and very suitable for large-scale industrial production.

The invention provides an oxygen-vacancy-rich Bi5O7I microsphere piezoelectric-photocatalyst and a preparation method thereof, and belongs to the technical field of light pressure concerted catalysis, and the preparation method comprises the following steps: mixing Bi (NO3) 35H2O and PEG 6000 powder, dissolving in absolute ethyl alcohol, uniformly stirring, dropwise adding a NaI solution, uniformly stirring again, sequentially washing and drying to obtain a dried product, and calcining the dried product to obtain the oxygen-vacancy-rich Bi5O7I microsphere piezoelectric-photocatalyst. The Bi5O7I microsphere piezoelectric-photocatalyst rich in oxygen vacancy is obtained; according to the invention, richer oxygen vacancies are introduced into the Bi5O7I powder, the spectral absorption range of the piezoelectric-photocatalyst is expanded, and the concentration of current carriers is improved by utilizing the capturing effect of the oxygen vacancies on electrons, so that the photocatalytic, piezoelectric catalytic and light-pressure synergistic catalytic efficiency of the piezoelectric-photocatalyst is improved; the oxygen-vacancy-enriched Bi5O7I microsphere piezoelectric-photocatalyst prepared by the preparation method disclosed by the invention has efficient organic dye degradation performance, and the catalytic effect of the oxygen-vacancy-enriched Bi5O7I microsphere piezoelectric-photocatalyst is far superior to that of pure-phase Bi5O7I powder.

According to the sodium-electric single-crystal layered positive electrode material precursor and the preparation method thereof, the sodium-electric single-crystal layered positive electrode material and the sodium-ion battery, high alkalinity is controlled in the coprecipitation process, the pH value is controlled in stages, oxidation is strictly controlled in the reaction process and the aging process, and the sodium-ion battery performance is improved. The secondary particle sphere or sphere-like single crystal precursor with the particle size D50 of 3.5-10.0 mu m and uniformly distributed elements and composed of thick insertion sheet-shaped primary particles can be obtained, ion segregation and generation of fine particles can be well inhibited, subsequent firing of a single crystal positive electrode material is facilitated, the smoothness and roundness of single crystal particles are improved, and the preparation method is simple and convenient to operate. The sintering difficulty of the single-crystal positive electrode material is reduced, the structure and performance of the positive electrode material are improved, and the performance of the sodium ion battery is further improved.

The invention provides a large-particle lithium-rich manganese-based precursor and preparation thereof, a positive electrode material and application, and the preparation method comprises the following steps: (1) enabling a first mixed salt solution, a precipitator solution and a complexing agent solution to flow into a reaction base solution in parallel, and carrying out a first co-precipitation reaction to obtain first slurry; (2) enabling a second mixed salt solution, a precipitant solution and a complexing agent solution to flow into the first slurry obtained in the step (1) in parallel, and carrying out a second coprecipitation reaction to obtain a large-particle lithium-rich manganese-based precursor; the second mixed salt solution contains an anionic surfactant. The anionic surfactant contained in the second mixed salt solution in the preparation method can reduce the surface tension of the reaction slurry, and alleviate the problem of non-uniform surface stress distribution in the synthesis process; in addition, in the preparation method, the anionic surfactant is negatively charged, and primary particles on the surface are combined more tightly through the electrostatic attraction effect; in addition, the preparation method is simple in process and low in requirements on equipment.

The invention provides a preparation method of fine low-oxygen spherical Ti-based high-entropy alloy powder, and relates to the technical field of spherical titanium-based alloy powder. The preparation method comprises the steps of raw material selection and treatment of the wire, preparation of the pre-alloyed wire, preparation of the titanium-based high-entropy alloy wire, treatment of the titanium-based high-entropy alloy wire, establishment of a gas system, high-frequency induction preheating, radio frequency plasma smelting and atomization pulverization which are carried out in sequence. Through multiple wire twisting, multiple continuous hot drawing, diffusion homogenization annealing, high-frequency induction preheating, radio frequency plasma smelting and atomization powder preparation, the Ti-based high-entropy alloy wire with uniform component distribution can be directly prepared at a low temperature, then the Ti-based high-entropy alloy fine powder with low oxygen content and uniform component distribution is prepared, and the Ti-based high-entropy alloy fine powder is suitable for additive manufacturing and has good application prospects. The method is high in flexibility, simple to operate, wide in application, low in cost and very suitable for large-scale industrial production.

The invention provides a spherical graphite material and a preparation method and application thereof, and the spherical graphite material meets the following conditions: the r value of the spherical graphite material is gt; 0.7, the sphericity degree of the spherical graphite material is larger than or equal to 0.75, 10 30 nm * 30 nm areas are randomly selected for any cross section of particles of the spherical graphite material, TEM images are obtained respectively, and graphite lattice layer-amorphous carbon layer-graphite lattice layer crystal form change areas exist in the TEM images of not larger than 3 areas. The prepared lithium-ion battery cathode material has the characteristics of high tap density and small orientation, so that the lithium-ion battery cathode material shows excellent processability, and shows the characteristic of low expansion when being applied to the lithium-ion battery cathode material. The graphite material is high in graphitization degree, and shows the characteristics of high capacity and high first efficiency when being applied to a lithium ion battery negative electrode material.

The invention provides a large-particle narrow-span distribution ternary precursor and a preparation method and application thereof, and belongs to the technical field of batteries, the preparation method comprises the following steps: ammonia concentration in a base solution A is 2.0-5.0 g / L, a nickel-cobalt-manganese metal salt solution, ammonia water and an alkali solution are introduced into the base solution A in a parallel flow manner, a first coprecipitation reaction is carried out, and a nickel-cobalt-manganese ternary precursor seed crystal is prepared; in the first coprecipitation reaction, the stirring rotating speed is 150 to 350rpm; a base solution B is prepared, the ammonia concentration in the base solution B is 5.0-7.0 g / L, a nickel-cobalt-manganese metal salt solution, ammonia water and an alkali solution are introduced into the base solution B in a parallel flow mode, a second coprecipitation reaction is conducted, and a nickel-cobalt-manganese ternary precursor is prepared; in the second coprecipitation reaction, the stirring rotation speed is 150 to 280 rpm. The problems that nickel-cobalt-manganese ternary precursor particles are prone to cracking and agglomeration are solved, and therefore the precursor narrow in particle size distribution and good in sphericity degree is obtained.

The invention discloses a high-nickel large-particle precursor as well as a preparation method and application thereof, and belongs to the technical field of battery materials. The preparation method of the precursor comprises the following steps: adding a metal salt solution, a precipitator solution and a complexing agent solution into a first reaction container with a base solution in a parallel flow manner, and carrying out a first co-precipitation reaction under a stirring condition until a preset particle size is reached, so as to obtain first slurry; transferring the first slurry into a second reaction container, simultaneously adding a metal salt solution, a precipitator solution, an additive solution and a complexing agent solution in a parallel flow manner, and carrying out a second coprecipitation reaction under a stirring condition to obtain second slurry; and concentrating the second slurry until the material grows to the target particle size, and aging. The preparation method is simple, can produce the high-nickel ternary large-particle precursor with high secondary particle sphericity degree, relatively wide distribution and mixed large and small particles, and is beneficial to solving the hidden dangers of the high-nickel ternary lithium battery in the aspects of performance and safety caused by secondary particle cracking of the high-nickel ternary precursor.

The invention discloses a preparation method of intermediate carbon microspheres, which comprises the following steps of: preparing precursor asphalt by taking naphthenic base aromatic hydrocarbon-rich heavy oil as a raw material and adopting a low-temperature thermal polycondensation process; the preparation method comprises the following steps: carrying out fluidized bed hydrotreatment on precursor asphalt under proper reaction conditions by matching with a proper isomerization functional catalyst and a molecular sieve catalyst to obtain refined aromatic hydrocarbon-rich distillate oil with a boiling range of more than 400 DEG C, and taking the refined aromatic hydrocarbon-rich distillate oil as a raw material; the preparation method comprises the following steps: carrying out a catalytic polycondensation reaction under the dual catalytic action of a heteropolyacid aluminum salt catalyst and a heteropolyacid ferric salt catalyst to obtain intermediate pitch, extracting the intermediate pitch through an extraction solvent, removing isotropic pitch components to obtain green carbon microspheres, and finally carrying out carbonization treatment on the green carbon microspheres to obtain the mesocarbon microbeads. The invention provides a brand new aromatic hydrocarbon-rich raw material refining treatment process through technical coupling, has the advantages of wide raw material application range and high production efficiency, and opens up a new path for low cost and high quality of mesocarbon microbeads.

The invention belongs to the technical field of water treatment materials, and particularly relates to a coal gasification slag unfired ceramsite filter material as well as a preparation method and application thereof. The coal gasification slag thermal insulation material comprises the following raw materials in parts by weight: 67.5-95 parts of coal gasification slag, 5-15 parts of active powder, 0-20 parts of metakaolin, 2-8 parts of expanded perlite, 0.1-0.5 part of a foam stabilizer and 1-3 parts of a foaming agent. The unfired ceramsite filter material has the advantages of being reusable, green and environment-friendly in preparation process, low in follow-up treatment cost, capable of being reused after failure and the like.

The invention provides a hydrophilic core-shell polylactic acid microsphere as well as a preparation method and application thereof, and belongs to the technical field of polylactic acid microspheres. The preparation method comprises the following steps: mixing polylactic acid with an organic solvent to obtain an oil phase, then mixing the oil phase with a surfactant solution for emulsification, controlling the emulsification rate to obtain polylactic acid microspheres with uniform particle sizes, and then mixing the polylactic acid microspheres with a modifier solution to obtain the hydrophilic core-shell polylactic acid microspheres. By controlling the variety of the modifier, the hydrophilicity, stability and reaction activity of the polylactic acid microspheres are improved, a silane coupling agent or an initiator does not need to be used in the preparation process, and the preparation method is safe and non-toxic.

The invention discloses a preparation method of an ultrahigh-temperature ceramic and refractory metal silicide composite coating on the surface of refractory alloy, and designs a preparation method of an ultrahigh-temperature ceramic and refractory metal silicide composite coating, which comprises the following steps: (1) preparing ZrC ceramic powder with better sphericity by adopting a spray granulation method; the preparation method comprises the following steps: (1) preparing an ultrahigh-temperature ceramic / refractory metal ((Zr, Ta) C-Ta (W)) coating with a gradient structure on a Ta-10W substrate by adopting a high-speed laser cladding process; and (3) a refractory metal phase in the (Zr, Ta) C-Ta (W) coating is converted into a corresponding silicide phase through an embedding siliconizing technology, and therefore the ultrahigh-temperature ceramic / refractory metal silicide ((Zr, Ta) C-TaSi2) composite coating is obtained. The novel composite coating disclosed by the invention has the properties of uniform tissue components, relatively high hardness, high compactness, continuous multi-layer structure, high-temperature ablation resistance and the like.

The present invention provides a rare earth metal modified layered positive electrode material for sodium ion batteries and a preparation method thereof. The main structure of the rare earth metal modified layered positive electrode material for sodium ion batteries is an O3 phase, and the chemical formula is NaNi a Fe b Mn c Re d O 2 , 0.28≤a≤0.33, 0.28≤b≤0.33, 0.28≤c≤0.33, 0≤d≤0.05, Re represents a rare earth metal element; the layered positive electrode material includes spherical secondary particles, the secondary particles include a plurality of stacked flaky primary particles, part of the rare earth metal elements are distributed on the surface of the secondary particles in the form of rare earth metal oxides, and part of the rare earth metal elements are doped in the layered positive electrode material lattice in the form of rare earth metal ions. The positive electrode material provided by the present invention is modified based on rare earth metal elements, and has good sphericity and rich pore structure. The battery containing the positive electrode material exhibits excellent rate performance and good cycle stability.

The invention discloses a soft magnetic alloy powder and a preparation method thereof, a magnetic ring inductor and a preparation method thereof, which belong to the field of alloy materials. Industrial pure iron, pure copper, industrial ferroboron, single crystal silicon, ferroniobium and ferrophosphorus with a purity of 99.9% are selected as raw materials, and a corundum crucible is added to burn steel. A supersonic gas atomization nozzle is used to atomize the obtained powder, and the water-powder separation and vacuum drying are carried out to obtain the required amorphous powder precursor; and the required amorphous nano soft magnetic alloy powder is obtained through the batch processing of crystallization annealing treatment, powder classification and screening. The beneficial effects of the invention are: through medium frequency induction melting, gas spray water cooling atomization, combined with the later water-powder separation, vacuum drying, crystallization annealing treatment, powder classification and screening and other processes, the prepared powder has the characteristics of good sphericity, low oxygen content, reasonable particle size distribution and the like.

The invention belongs to the technical field of ceramic tube preparation, and particularly relates to a pressureless sintered silicon carbide grinding medium and a preparation method thereof. The invention relates to a preparation method of a pressureless sintered silicon carbide grinding medium, which comprises the following specific steps: proportioning: preparing basic materials of the silicon carbide grinding medium according to the weight ratio: 98-99 wt% of submicron silicon carbide and 1-2 wt% of boron carbide; ball-milling and mixing; performing spray granulation; intensely stirring, mixing and granulating; drying the biscuit; dewaxing the biscuit; and sintering at high temperature to finish preparation. The preparation method is simple in technological process, use of large forming equipment such as a dry press and a cold isostatic press is avoided, the production input cost is greatly reduced, and the prepared pressureless sintered silicon carbide grinding medium is good in sphere sphericity degree, high in density, high in strength, high in toughness, ultrahigh in wear resistance, long in service life, resistant to high temperature and good in chemical stability.

The invention discloses a preparation method of high-nitrogen steel powder with ultrahigh nitrogen content, which specifically comprises the following steps: adding the high-nitrogen steel powder into a vacuum boiler filled with nitrogen for heating, and continuously stirring to uniformly heat the powder and avoid agglomeration at the same time; after heat preservation is conducted for a proper time, a filter screen window below the boiler is opened, meanwhile, a lower powder outlet of the boiler is opened, and powder in the boiler is screened through a filter screen under the action of high-pressure nitrogen jet flow; the screened powder falls into a liquid nitrogen pool for rapid cooling and nitrogen dissolving treatment; and after the powder is treated by liquid nitrogen for a certain time, a filter screen at the bottom of the liquid nitrogen pool is opened to treat redundant liquid nitrogen and screen the powder, and finally the high-nitrogen steel powder with the ultrahigh nitrogen content is obtained in the liquid nitrogen pool. According to the method, the high-nitrogen steel powder with the ultrahigh nitrogen content can be obtained on the basis of traditional high-nitrogen steel powder preparation, and the method has the advantages of being simple in process, low in cost, high in practicability, convenient to achieve industrial production and the like.

The invention discloses metal ceramic spraying powder and a preparation method thereof, and relates to the technical field of metal ceramic powder spraying materials. The metal ceramic spraying powder comprises one or more of titanium carbonitride, titanium carbide and titanium nitride; the metal ceramic spraying powder disclosed by the invention is uniform in component and has excellent sphericity, so that the spraying powder is good in flowability, and an obtained coating is good in stability; the coating formed by the spraying powder and the matrix metal surface layer is high in binding force, the advantages of corrosion resistance, high temperature resistance, low porosity, high density, high red hardness and the like are also achieved, and the preparation method is simple, easy to implement, low in cost and easy for mass production.