512 results about "Argon atmosphere" patented technology

The invention provides a high-stability lithium-rich manganese-based positive electrode material and a preparation method thereof, and relates to the technical field of lithium-rich manganese-based positive electrode materials, and the method comprises three steps of preparation of a homogeneous precursor, solid-state mechanical fusion doping and coating, and high-temperature sintering; a lithium-rich manganese-based precursor is prepared by adopting a homogeneous coprecipitation process, uniform distribution of metal ions is ensured, then an aluminum source, a zirconium source and a fluorine source are introduced as doping agents, phosphate and a titanate coating agent are combined, doping and coating integrated treatment is realized through mechanical ball milling, and the lithium-rich manganese-based composite material is obtained. And finally, mixing with a lithium source in an argon atmosphere, and carrying out high-temperature sintering of temperature programming and staged heat preservation to form a stable composite coating layer in situ. Therefore, manganese ion migration is effectively inhibited through lattice doping, a layered structure is prevented from being converted into spinel or rock salt phase, meanwhile, a nanoscale ion / electron transmission channel is constructed, interface impedance is reduced, and the charging and discharging efficiency under high voltage is improved.

The invention belongs to the technical field of superfine tungsten powder, and particularly relates to superfine tungsten powder and a preparation method thereof.The preparation method includes the steps that an ammonium tungstate solution, hydrochloric acid and carbon black serve as raw materials to prepare a mixture of tungstic acid and a carbon precursor; calcining the tungstic acid and carbon precursor mixture in a nitrogen atmosphere to obtain a tungsten oxide and carbon mixture; a tungsten oxide and carbon mixture is calcined in an argon atmosphere, the argon atmosphere is kept for natural cooling, the superfine tungsten powder is obtained, the superfine tungsten powder is uniform in dispersion, complete in grain development, smooth in surface, free of pores and complex in morphology, the crystal structure of the superfine tungsten powder is a body-centered cube, the average particle size is smaller than or equal to 0.7 micrometer, and the specific surface area is smaller than or equal to 1.0 m < 2 > / g.

The invention discloses a carbon-doped titanium dioxide nanotube-molybdenum disulfide energy-storage antibacterial material and a preparation method thereof. The preparation method comprises the following steps: carrying out primary anodic oxidation on a clean titanium foil in a mixed electrolyte of ethylene glycol, water and ammonium fluoride; after ultrasonic treatment is carried out in a hydrochloric acid solution for set time, secondary anodic oxidation is carried out, and the mixed electrolyte of the secondary anodic oxidation is the same as that of the primary anodic oxidation; annealing the titanium foil subjected to anodic oxidation twice in an argon atmosphere, putting an annealed sample into a mixed solution of sodium molybdate, a sulfur source and glucose, and carrying out hydrothermal treatment; and the titanium foil subjected to hydro-thermal treatment is cleaned and dried, and the carbon-doped titanium dioxide titanium foil with the surface covered with molybdenum disulfide is obtained. The MoS2-coated carbon-doped titanium dioxide nanotube (TNT-C-atMoS2) with high biocompatibility developed by the invention has a synergistic effect of charge antibiosis and chemical sterilization, so that the problem of intractable biological fouling of a titanium-based metal material in ocean engineering equipment is effectively solved.

The invention discloses a preparation method and application of a high-capacity starch-based sodium ion hard carbon negative electrode material. The preparation method comprises the following steps: adding maleic anhydride and zinc chloride into starch, uniformly mixing, putting into a crucible, putting into a drying oven of 50-100 DEG C for esterification treatment, then heating to 240-280 DEG C for pre-carbonization treatment, and collecting a precursor solid; crushing the precursor solid, putting the crushed precursor solid into a ball milling tank, and carrying out ball milling to obtain intermediate powder; and putting the intermediate powder into a graphite boat, putting the graphite boat into a tubular furnace, and performing high-temperature carbonization in an argon atmosphere to obtain the starch-based sodium ion hard carbon negative electrode material. According to the starch-based sodium ion hard carbon prepared through joint modification of maleic anhydride and zinc chloride, the interlayer spacing is remarkably increased, the oxygen content of the material is reduced, and the disorder degree, the number of closed pores and the volume are increased. The method is simple and convenient in operation steps and has the potential of large-scale production.

The application discloses a kind of derived biomass hard carbon material pulverization process, belong to biomass charcoal material processing technical field, first, pulverization process includes the following steps: after drying, the coconut shell derived hard carbon block is carried out primary crushing, while spraying first modifier, obtain the particle size 1~3mm of coarse crushing modified particle;Coarse crushing modified particle is carried out secondary precision crushing under argon atmosphere, while spraying second modifier, obtain the precision crushing modified particle of D 50 Particle size is 15 μm;Precision crushing modified particle is carried out roll grinding spheroidization, while spraying third modifier, obtain the spherical modified particle of D 50 Particle size is 10 μm;Spherical modified particle is carried out flash drying after cooling, then add magnesium stearate to it, after mixing, obtain derived biomass hard carbon material.Then, the application realizes breakthrough in tap density, particle size distribution, first efficiency and other core indexes by the coordination of three-stage gradient modification and progressive pulverization process.

The invention discloses preparation of a high-performance carbon matrix embedded iron-based catalyst based on a metal organic framework precursor and application of the high-performance carbon matrix embedded iron-based catalyst in reverse water-gas shift reaction. In the preparation process, commercially available 1, 3, 5-trimesic acid iron (the chemical formula is C9H3FeO6, abbreviated as Fe-BTC) is selected as a raw material, pyrolysis treatment is carried out in an argon atmosphere, then air passivation is carried out, and finally the high-performance carbon matrix embedded iron-based catalyst based on the metal organic framework precursor is successfully prepared. The MOF-600 has excellent performance in many catalysts, the carbon dioxide production rate reaches 24.0 mmol CO.gcat <-1 >. S <-1 > at the temperature of 400 DEG C in a reverse water gas shift reaction, the performance is remarkably superior to that of an existing non-noble metal catalyst, and extremely high catalytic efficiency and application potential are shown.

The invention discloses a modified metal oxide catalyst and a plasma coupling electro-catalysis ammonia synthesis system based on the catalyst, cobalt oxide is modified by using radio frequency inductively coupled plasma (ICP) under a vacuum condition and an argon atmosphere, and the cobalt oxide catalyst rich in defects is obtained after discharging is finished. The ammonia synthesis system comprises a plasma activated air system and an electrocatalytic ammonia synthesis system; carrying out plasma discharge on air to generate NOX, cooling, and introducing the NOX into the absorption liquid; the absorption liquid is used as catholyte for electrocatalytic ammonia production in an H-shaped pool, and a cobalt oxide catalyst modified by plasma treatment is selected as a cathode. The cobalt oxide is treated by ICP, so that the problems of low conductivity, inert surface and the like of metal oxide are solved, and the performance of the catalyst is improved. The method solves the problems that plasma air discharge products are complex, and the ammonia yield is low due to the fact that N is equivalent to N cannot be efficiently activated through electro-catalysis.

The invention relates to a carbon carrier material for microwave-assisted phosphoric acid treatment and oxygen reduction, a catalyst, a preparation method and application thereof, and the scheme is innovated by the following steps: dipping conductive carbon black (such as ketjen black ECP600JD) and 60-70wt% phosphoric acid solution according to a solid-to-liquid ratio of 1g / (15-18) mL, preheating at 100-250 DEG C in an argon atmosphere, then carrying out a reaction for 10-100 seconds under the assistance of a microwave power of 100-600 W, and carrying out vacuum drying to obtain the carbon carrier material for microwave-assisted phosphoric acid treatment and oxygen reduction. The phosphorus content of the prepared carbon carrier material is 4-6wt%, and the graphitization degree of the carbon carrier material is improved (ID / IG value is 1.15-1.20). And after the platinum-cobalt alloy is further loaded, the particle size of the nanoparticles is uniform, the potential loss is only 3 mV after 5000 accelerated attenuation tests in the proton exchange membrane fuel cell, and the power density attenuation is reduced by 58%. The method has the advantages of quick reaction, low energy consumption, high corrosion resistance and the like, and the stability of the catalyst is remarkably improved.

The invention discloses high-flexibility low-reflection flexible photovoltaic glass and a preparation method thereof, and belongs to the technical field of photovoltaic glass preparation. The preparation method comprises the following steps: carrying out cleaning and plasma activation treatment on a flexible glass substrate in an argon atmosphere at the power of 100W for 5 minutes; spin-coating a perovskite precursor solution and annealing to form an active layer, and depositing a transparent conductive layer and a back electrode; carrying out vacuum lamination packaging by adopting an EVA material; coating an acrylic acid adhesive transition layer; spin-coating ultraviolet cured SiO2 sol to form an inorganic coating; a PVDF / Ag / PVDF sandwich structure is constructed, the coverage rate of the nano-silver is 40-50%, and the PVDF layer contains 0.5% of antioxidant. After the flexible photovoltaic glass is circularly bent for 1000 times under the curvature radius of 5mm, the recovery rate is greater than 95%, the PAR transmittance is greater than 92.5%, the NIR reflectivity is greater than 89.3%, the reflectivity retention rate is greater than 96% after the flexible photovoltaic glass is aged for 100 hours at 85 DEG C / 85% RH, and the flexible photovoltaic glass has excellent flexibility, optical performance and environmental stability.

The invention relates to the technical field of waste resourceful treatment, in particular to a sponge titanium weight bottom skin crushing and impurity removing method which comprises the following steps of peeling, bottom skin brake cutting, water jet cutting and crushing, acid leaching and impurity removing, ultrasonic cleaning, argon drying and screening and recycling. The bottom skin is crushed into small-granularity particles by adopting a cross grid water jet cutting technology, metal impurities such as Fe and Ni are removed in combination with acid leaching treatment, residual impurities are removed through multi-stage ultrasonic cleaning, oxidation discoloration is avoided through argon atmosphere drying, and meanwhile water jet sand is recycled; in the process, key indexes such as brake cutting pressure, cutting parameters, acid leaching time and ultrasonic frequency are accurately controlled through a quantification formula. The method effectively solves the problems that equipment is easy to damage during crushing and impurities are difficult to remove in a traditional process, remarkably improves the grade of bottom leather materials, widens the downstream application range, improves the resource utilization rate and economic benefits, and is suitable for industrial batch production.

The invention relates to a preparation method of an oxygen vacancy-rich bismuth molybdate / bismuth vanadate composite photo-anode and a product and application thereof, and belongs to the technical field of photoelectrocatalysis. The invention discloses a preparation method of an oxygen vacancy-rich bismuth molybdate / bismuth vanadate (Bi2Mo2O9 / BiVO4) composite photo-anode, which mainly comprises the following steps: immersing a fluorine ion-doped tin dioxide (FTO) conductive glass substrate into a Bi < 3 + > ion solution and an I <-> ion solution to form a bismuth oxyiodide (BiOI) film, dropwise adding a dimethyl sulfoxide solution of vanadyl acetylacetonate (VO (acac) 2), and putting into a muffle furnace to prepare the BiVO4 photo-anode. And then vertically immersing into a Bi < 3 + > ion solution and a Mo < 6 + > ion solution, and carrying out annealing treatment in an argon atmosphere to prepare the Bi2Mo2O9 / BiVO4 composite photoanode rich in oxygen vacancies. The Bi2Mo2O9 / BiVO4 material rich in oxygen vacancies is a metal oxide composite photo-anode, the photoelectrocatalysis efficiency can be improved, and hydrogen peroxide (H2O2) can be continuously generated in natural seawater through photoelectrocatalytic oxidation of water for a long time.

The invention discloses a method for preparing (SmxY1-x) Co5 rare earth magnetic particles with high magnetic properties by a chemical method, and belongs to the field of rare earth magnetic materials. The invention particularly relates to a novel technology for preparing (SmxY1-x) Co5 ternary alloy magnetic powder with high magnetic properties by combining chemical liquid phase synthesis with calcium reduction reaction. A Sm (OH) 3 / Y (OH) 3 / Co (OH) 2 (at) Ca (OH) 2 crystalline state mixed precursor prepared by chemical coprecipitation and a hydrothermal reaction is uniformly subjected to a complete calcium reduction reaction with a certain amount of metal calcium particles, KCl and CaCl2 diffusion media in an argon atmosphere, and the magnetic powder is prepared. The saturation magnetization intensity and the residual magnetization intensity of the magnetic powder are improved by doping the yttrium element, but the coercive force of the magnetic powder is slightly reduced, and the method provides a new thought for preparing high-performance rare earth magnetic particles.

The invention discloses a catalysis-high temperature synergistic preparation method of a lignin-based electromagnetic shielding carbon material, which comprises the following steps: carbonizing lignin, dipping in an aqueous solution containing Mn < 2 + > overnight, drying, carrying out graphitization reaction in an argon atmosphere, and cooling to obtain a final product. After lignin pyrolytic carbon is impregnated with Mn < 2 + >, growth of graphite microcrystals is promoted through cooperation of the catalytic graphitization effect and the high-temperature effect of Mn under a certain temperature condition, finally, the temperature is further increased, Mn is gasified and removed while the graphitization degree is increased, and follow-up acid pickling operation is avoided. The shielding effectiveness of the obtained product on electromagnetic waves with the wave band of 1-8.5 GHz can be close to 40 dB, the medium shielding performance is achieved, and the good application prospect is achieved.

The invention discloses an all-chemical vapor deposition preparation method of a carbon-carbon heater with the density of 1.6-1.8 g / cm < 3 >, and belongs to the technical field of carbon-carbon heater preparation. The scheme comprises the following steps: 1) preparing a carbon fiber preform with the volume density of 0.5 + / -0.03 g / cm < 3 > by adopting a needling process; 2) taking natural gas as a carbon source, taking low-molecular mixed hydrocarbon gas as auxiliary gas, and performing densification treatment on the carbon fiber preform by adopting an all-chemical vapor deposition method in a nitrogen or argon atmosphere; and (3) carrying out high-temperature graphitization treatment on the densified preform, and sleeving a graphite tool into the heater for fixing in the treatment process, so as to prepare the carbon-carbon heater with the density of 1.6-1.8 g / cm < 3 >. The carbon-carbon heater prepared by the preparation method has the characteristics of stable heat supply, no resistance fluctuation, good corrosion resistance, long service life, short preparation period and the like.

The invention discloses a press-fit preparation method of a high-thermal-conductivity circuit board and the high-thermal-conductivity circuit board, and the preparation method comprises the steps: carrying out the dispersion and solidification of a liquid metal gallium-indium alloy and fiber mixture in an inert argon atmosphere, and fusing with a substrate, and obtaining a self-adaptive heat-conduction substrate; carrying out gradient deposition and etching treatment on the self-adaptive heat conduction base material to obtain a gradient spacing template; carrying out electrospinning infiltration and heat treatment on the gradient spacing template to obtain a base material containing a dynamic heat-conducting network; conducting layer pre-pressing treatment is conducted on the base material containing the dynamic heat conduction network, and a pre-assembled plate is obtained; performing staged dynamic pressing treatment on the pre-assembled board to obtain a molded circuit board; and performing surface spraying and deposition treatment on the molded circuit board to obtain the high-thermal-conductivity circuit board. The problems of poor heat flow path, poor interface bonding performance and the like in the prior art are solved, the heat management effect is remarkably improved, and the reliability and performance of an electronic product are remarkably improved.

The preparation method of the Ni-Mn bimetallic oxide modified magnesium-based hydrogen storage composite material comprises the steps that 1, under the protection of an argon atmosphere, pure magnesium powder is placed in a reaction kettle, and a product MgH2 is obtained; step 2, dissolving nickel nitrate hydrate and manganous nitrate hydrate in absolute ethyl alcohol, adding urea into the mixed solution, continuously stirring at room temperature, and then carrying out constant-temperature reaction in a tetrafluoropolyvinyl chloride high-pressure reaction kettle in a drying oven; after the reaction is finished, cooling to room temperature, and carrying out centrifugal washing; supernate obtained after centrifugal washing is poured out, precipitates are reserved and transferred into a vacuum drying box, and vacuum drying is conducted; grinding a block obtained after drying, and transferring the block into a tubular furnace for heat treatment to obtain a bimetallic oxide NiMn2O4; 3, MgH2, NiMn2O4 and stainless steel ball milling beads are weighed and put into a mechanochemical reaction ball milling kettle, intermittent ball milling is conducted for a certain time under the protection of a specific atmosphere, and then a composite sample MgH2-NiMn2O4 is collected. The practical application benefit of the magnesium-based hydrogen storage technology can be greatly improved.

A nickel iron phosphide / nickel molybdate core-shell structure composite electrode material, the nickel iron phosphide / nickel molybdate core-shell structure composite electrode has a nickel foam substrate, and the nickel foam substrate has an array of nickel iron phosphide / nickel molybdate core-shell structure. The present invention also relates to a preparation method of the electrode, comprising the following steps: first pre-treating the nickel foam substrate to remove oxides and impurities on the surface of the nickel foam substrate; placing the nickel foam in a reactor for hydrothermal treatment by an in-situ growth method to obtain a nickel molybdate precursor with a cubic array structure; then placing the nickel molybdate precursor in a potassium ferrocyanide solution for ion exchange to obtain a nickel iron Prussian blue / nickel molybdate composite electrode; finally, placing the nickel iron Prussian blue / nickel molybdate composite electrode in a tubular furnace, phosphating under an argon atmosphere, and obtaining a nickel iron phosphide / nickel molybdate core-shell structure composite electrode. The preparation method of the present invention is simple, and the prepared nickel iron phosphide / nickel molybdate core-shell structure composite electrode has significantly improved electrochemical performance and stability compared with a single phosphide electrode.

The invention discloses a ZnF2 (at) FeF3. 0.33 H2O positive electrode material as well as a preparation method and application of the ZnF2 (at) FeF3. 0.33 H2O positive electrode material. The preparation method comprises the following steps: step 1, uniformly mixing ethanol and PEG-400 to obtain a mixed solvent; 2, ferric nitrate and zinc nitrate are dissolved in a mixed solvent, then an HF aqueous solution is dropwise added into the obtained solution under stirring, after stirring, the obtained mixed solution is transferred into a stainless steel high-pressure kettle to be heated in a closed mode and cooled to the room temperature, a product is washed, centrifuged and dried in vacuum, and powder is obtained; 3, the powder is placed in a tubular furnace and subjected to heat preservation treatment in the argon atmosphere, then the powder is naturally cooled to the room temperature, a product is taken out and ground, and the ZnF2-coated FeF3. 333 H2O material is obtained. By doping ZnF2, FeF3. 0.33 H2O has higher electronic conductivity and a more stable structure, and an all-solid-state lithium battery prepared from the FeF3. 0.33 H2O has higher specific capacity and better cycling stability.

The invention discloses a one-dimensional tubular selenide-carbon composite material assembled by hollow particles and a preparation method and application thereof.The preparation method comprises the following steps that ZnCo-ZIF nanotubes and 2, 5-dihydroxyterephthalic acid are mixed, N, N-dimethylformamide is added, a reaction is conducted, after the reaction is completed, a product is subjected to centrifugal separation, and the one-dimensional tubular selenide-carbon composite material assembled by the hollow particles is obtained. And washing and drying to obtain the one-dimensional tubular MOF material assembled by the hollow particles. And annealing the MOF material in an argon atmosphere to obtain the one-dimensional porous carbon nanotube material assembled by the hollow particles. And then uniformly mixing with selenium powder, and annealing under argon protection to obtain the one-dimensional tubular selenide-carbon composite material assembled by hollow particles. The method is simple to operate and controllable in process, and the prepared product is widely applied to the fields of energy storage, catalysis, environmental governance, biomedicine and the like.

The application discloses a high-performance stainless steel-based electrolytic water dual-function electrode and application thereof, and the electrode is prepared through the following steps: step 1, pretreating a stainless steel surface to remove impurities on the surface; step 2, placing the stainless steel obtained after the treatment in step 1 and a phosphorus source in an argon atmosphere under the condition of 350-450 DEG C, phosphorizing the stainless steel for 1-3 hours to obtain a phosphorized stainless steel electrode, wherein the linear distance between the phosphorus source and the stainless steel is kept at 5-10 cm; and step 3, placing the phosphorized stainless steel electrode obtained after the treatment in step 2 in a RuCl3 solution, and performing electrodeposition on the phosphorized stainless steel as a cathode to obtain the electrode, wherein the concentration of the RuCl3 solution is 2-8 mmol / L, the potential window during the electrodeposition is-2 V-0 V, and the electrodeposition time is 15-25 cycles.

The invention relates to the technical field of preparation of silicon carbide ceramics, in particular to an in-situ reaction sintered silicon carbide ceramic and a preparation method thereof.The preparation method comprises the following technological stages which are conducted in sequence: S1, preparation of silicon carbide slurry, specifically, organic matter precursor raw materials are weighed according to the mass content percentage to form the silicon carbide slurry; s2, vacuum grouting: injecting the silicon carbide slurry in the vacuum grouting tank into the shaping mold from the bottom of the shaping mold to form a silicon carbide green body; and S3, in-situ reaction sintering is conducted, specifically, the silicon carbide green body is placed in a sintering furnace, heating, heat preservation and cooling are conducted on the silicon carbide green body in the argon atmosphere through a segmented temperature control technology, and the silicon carbide ceramic is obtained. The silicon carbide ceramic prepared by the method disclosed by the invention has relatively high density and excellent mechanical properties.

The invention belongs to the technical field of powder preparation, and relates to a preparation method of submicron 3C-SiC powder, which comprises the following steps: (1) mixing silicon powder, a carbon-containing raw material and a fluorine-containing raw material according to a certain proportion, fully ball-milling and uniformly mixing the powder and then drying, (2) putting the dried powder into an atmosphere furnace, introducing argon atmosphere, heating to 1400-1500 DEG C, preserving heat for 1-3 hours, and cooling to room temperature to obtain the submicron 3C-SiC powder. And (3) putting the reacted powder into a muffle furnace, and carrying out carbon removal treatment, so as to obtain the high-purity 3C-SiC powder. And the prepared powder is uniform in morphology and granularity and relatively high in purity. The method is simple, has low requirements on instruments and equipment, and is suitable for batch production. The 3C-SiC powder synthesized and prepared through the method is uniform in particle size (about 130 nm) and special in morphology, and a spherical structure is formed. The method is relatively simple in preparation process and convenient to operate, and lays a certain foundation for industrial production.

The invention relates to an easy-to-prepare low-cost high-performance sodium ion battery hydrogen peroxide modified hard carbon negative electrode material, and a preparation method comprises the following steps: S1, crushing alfalfa, cleaning, filtering, and carrying out vacuum drying to obtain a biomass precursor material; s2, performing low-temperature cracking, and annealing in an argon atmosphere to obtain a hard carbon precursor carbon material; s3, completely dispersing the hard carbon precursor material in the step S2 in deionized water to obtain a hard carbon precursor material mixed solution, dropwise adding an acid solution to adjust the pH value, then dropwise adding a hydrogen peroxide aqueous solution, filtering and washing to be neutral after reaction to obtain an intermediate product, and performing vacuum drying to obtain a modified hard carbon precursor carbon material; and S4, performing high-temperature pyrolysis and annealing under the protection of an argon atmosphere. The biomass alfalfa is used as a main raw material, and compared with a hard carbon negative electrode material prepared from a traditional biomass material, the specific capacity, the first coulombic efficiency and the capacity retention rate are remarkably improved.

The invention discloses a high-toughness and high-entropy alloy with dynamically-enhanced dislocation cells and a preparation method of the high-toughness and high-entropy alloy, and relates to the technical field of alloy preparation. The preparation method sequentially comprises the following steps that S1, in a high-purity argon atmosphere, an alloy ingot is prepared through a suspension melting method, and then homogenization treatment is conducted for 24 h at the temperature of 1200 DEG C; and S2, multi-pass small-strain rolling is carried out in three steps, namely cold rolling, hot rolling and cold rolling, the total thickness is reduced by 84%, and the high-toughness and high-entropy alloy with the dynamically-enhanced dislocation cells is obtained. According to the preparation method, the dislocation cell structure can be prepared in the high-entropy alloy, the steps are simple, the efficiency is high, the risk caused by additional defects is avoided, and meanwhile the preparation method is not limited by the sample size. More importantly, the obtained dislocation cell structure can be dynamically enhanced in the deformation process, so that the alloy has higher ductility under the flow stress of kilomega Pa, and the balance between the strength and the ductility is avoided.

The invention discloses a plasma arc fuse wire additive manufacturing method of a high-performance rare earth magnesium alloy. The manufacturing method comprises the following steps: step 1, preparation before deposition; secondly, deposition forming is conducted; and thirdly, in-situ standing and cooling are conducted in the argon atmosphere, and the ZM6 magnesium alloy workpiece is obtained. According to the manufacturing method, the plasma with more stable heat input quantity is adopted as a heat source, ZM6 magnesium alloy additive manufacturing is carried out, volatilization of alloy elements and melt splashing can be reduced, air holes and other defects are avoided, the problems that a ZM6 magnesium alloy workpiece manufactured through a traditional casting method is high in cost, and shrinkage cavities and inclusions exist in the workpiece are solved, and the product quality is improved. The method is suitable for the technical field of metal additive manufacturing.

The invention belongs to the technical field of powder metallurgy, and particularly relates to a high-fluidity MIM metal feed and a forming process thereof.The high-fluidity MIM metal feed is composed of the following materials: metal powder: spherical metal powder (a titanium alloy TC4 material), polycaprolactone and graphene nanosheets; wherein the volume ratios are 68-72 vol%, 0.5-2 wt% (based on the mass of the metal powder) and 0.1-0.5 wt% (based on the mass of the metal powder) respectively; a powder oxide layer is removed through vacuum plasma cleaning (300-500 W, argon atmosphere), a metal core-PCL / graphene shell structure is prepared in combination with ultrasonic-assisted in-situ polymerization, lubrication and adhesion enhancement are synchronously achieved, the powder oxygen content is controlled to be smaller than 500 ppm, and sintering oxidation defects are reduced.

The present invention provides a zinc oxide / titanium dioxide / titanium carbide composite microwave absorbing material and a preparation method thereof, belonging to the technical field of electromagnetic wave absorbing materials. The method first adds Ti3C2T x nanosheets into deionized water and stirs evenly to obtain a Ti3C2T x nanosheet suspension; dissolves Zn(CH3COO)2·2H2O in methanol to obtain a Zn(CH3COO)2·2H2O solution; finally mixes the two solutions, transfers them to a Teflon-sealed autoclave for reaction, and performs heat treatment in a tubular furnace under an argon atmosphere to obtain a zinc oxide / titanium dioxide / titanium carbide composite microwave absorbing material. The composite microwave absorbing material has a rose-shaped, sandwich-like hamburger-shaped or spiny sea urchin-shaped structure. By partially oxidizing titanium carbide and introducing a material with a moderate dielectric constant, a zinc oxide / titanium dioxide / titanium carbide composite microwave absorbing material with a special morphology is prepared to improve the problem of limited microwave absorbing performance caused by the too high conductivity of titanium carbide.

The invention discloses a SiC reinforced CrMnFeCoNi high-entropy alloy composite material and a preparation method thereof, and belongs to the technical field of composite materials and preparation thereof. The composite material disclosed by the invention comprises the following components in percentage by mass: 95 to 99.5 percent of CrMnFeCoNi high-entropy alloy and 0.5 to 5 percent of SiC, the preparation method comprises the following steps: S1, carrying out ball milling on CrMnFeCoNi high-entropy alloy powder in an argon atmosphere; s2, SiC powder is added into the CrMnFeCoNi high-entropy alloy powder obtained after ball milling in the step S1, ball milling continues to be conducted in the argon atmosphere, and composite material powder is obtained; and S3, the composite material powder prepared in the step S2 is subjected to vacuum hot pressing sintering, and a SiC reinforced CrMnFeCoNi high-entropy alloy composite material block is obtained. Through the step-by-step ball milling process, the negative influence generated by a brittle phase is reduced, and meanwhile, the strength of the composite material is remarkably improved, so that the comprehensive performance of the composite material is in a rising trend, and the comprehensive performance of the composite material is at a better level.

The invention relates to a method for improving the purity of tundish molten steel, and belongs to the technical field of continuous casting pouring processes in the metallurgical industry. According to the technical scheme, the method comprises the steps that firstly, a plurality of blowing devices (1) facing the interior of the tundish are arranged in the circumferential direction of the side wall of the tundish; secondly, before casting is started, argon is blown into the tundish through a blowing device (1), air in the tundish is exhausted, and an argon atmosphere is formed; and thirdly, after casting is started, after the liquid level of the molten steel in the tundish exceeds the height of the blowing device (1), argon continues to be blown into the tundish, and the molten steel in the tundish is stirred through the argon blown into the tundish in different directions. The argon blowing device has the beneficial effects that air in the tundish can be discharged before casting to form an argon atmosphere, argon is continuously blown into the tundish after the height of molten steel exceeds the height of the blowing device after casting, the argon blown into the tundish in different directions stirs the molten steel, inclusions in the molten steel are promoted to float upwards and enter a covering agent above the molten steel level, and the molten steel is prevented from entering the covering agent. The purpose of reducing inclusions in the molten steel is achieved.

The invention belongs to the field of silicon carbide ceramics, and discloses a method for preparing nano-whisker reinforced reaction sintered silicon carbide ceramics, comprising: mixing 55-75% silicon carbide powder and 10-20% carbon black by ball milling, then adding 15-35% ceramic precursor resin waste, and then adding a binder, a dispersant and water to obtain a slurry; injecting the slurry into a mold for molding, and obtaining a porous ceramic body after demoulding; burying the porous ceramic body with silicon powder, heating to 1300-1500° C. in a flowing argon atmosphere, and keeping the temperature, so that the ceramic precursor generates ceramic nano-whiskers in situ during atmosphere sintering, and obtains an enhanced SiC / C porous ceramic preform; heating to 1600-1700° C., vacuum keeping the temperature, and obtaining nano-whisker reinforced reaction sintered silicon carbide ceramics. The method of the invention is simple, can generate ceramic nano-whiskers in situ, and can achieve toughening of reaction sintered silicon carbide ceramics through a stress loss mechanism inside the material.