35 results about "Nanocrystalline composites" patented technology

The invention relates to the technical field of electronic component manufacturing, and discloses a method for improving the anti-aging capability of an inductance magnetic core, which comprises the following steps: pretreatment and bottom layer electroplating: performing oil removal and acid pickling activation on the inductance magnetic core, performing nickel electroplating treatment after cleaning, and forming a bottom nickel layer on the surface of the end of the magnetic core; chemical densification deposition: adopting the plating solution in the first aspect, immersing the magnetic core treated in the step (1) into the heated plating solution, and reacting under the condition of not applying impressed current, a Ni-P-B-W barrier layer is deposited on the surface of a bottom nickel layer, an amorphous-nanocrystalline composite structure is constructed on the surface of an electrode through a combined process of bottom nickel electroplating, middle chemical deposition of the Ni-P-B-W compact barrier layer and surface tin electroplating, the barrier layer utilizes the co-deposition effect of phosphorus, boron, tungsten and nickel, the grain boundary defect is eliminated, and the performance of the electrode is improved. And a mutual diffusion path of bottom layer metal and surface layer tin and a permeation channel of an external corrosive medium are effectively blocked.

The utility model discloses steam turbine high pressure cylinder and medium pressure cylinder shaft seal body outer cylinder body spraying heat insulation material heat preservation structure, including base layer, main heat insulation layer, transition layer, ceramic fiber suture line layer, anchor nail, heat reflection layer, ceramic fiber reinforced layer and protective surface layer. Base layer adopts nanometer silane interface agent to spray on the surface of cylinder body, and main heat insulation layer is nanocrystalline composite heat insulation material, and transition layer is composed of metal base layer, ceramic base layer and organic composite base layer, and the multiple suture lines of ceramic fiber suture line layer are orthogonal grid inlay in the surface of main heat insulation layer, and anchor nail top is equipped with barb structure and root installs elastic silicone rubber gasket, and heat reflection layer is the aluminum foil that etches nanometer level groove and is equipped with wave embossing, and ceramic fiber reinforced layer is sealedly installed paraffin, and protective surface layer adopts organic silicon modified acrylic resin material. The structure has solved the problems of easy cracking of heat insulation layer, easy breaking of heat preservation material, unreasonable shaft seal heat preservation and oil touch flammable etc, and has improved heat preservation performance, structural stability and safety.

The invention belongs to the technical field of permanent magnet materials, and relates to a nanocrystalline composite permanent magnet material and a manufacturing method thereof. The nanocrystalline composite permanent magnet material comprises a hard magnetic phase and a soft magnetic phase, the grain size of the hard magnetic phase and the grain size of the soft magnetic phase are independently smaller than or equal to 25 nm; the content of the soft magnetic phase is greater than 40 wt.%; the hard magnetic phase comprises a hard magnetic main phase, the proportion of the hard magnetic main phase in the hard magnetic phase is larger than 50 wt.%, and the hard magnetic main phase is a rare earth cobalt-based hard magnetic phase. The maximum magnetic energy product of the nanocrystalline composite permanent magnet material obviously exceeds the theoretical upper limit of the magnetic energy product of the single-phase hard magnetic material of the hard magnetic main phase. The giant magnetic energy product effect of the nanocrystalline composite permanent magnet material is realized by strictly controlling the raw material ratio and the preparation process.

This invention belongs to the field of hydrogen barrier coating technology, specifically relating to a nickel-phosphorus-based amorphous-nanocrystalline composite hydrogen barrier coating and its preparation method. The coating uses a nickel-phosphorus alloy as an amorphous matrix, embedding a composite nano-reinforcing phase composed of core-shell structured phosphide nanoparticles, molybdenum disulfide-metal hydroxide heterostructure two-dimensional nanosheets, and silane coupling agent-modified hexagonal boron nitride nanosheets. The microstructure exhibits a coexistence of amorphous and nanocrystalline phases, with a small amount of alloying elements added to the matrix. This invention involves the controlled preparation of three composite nano-reinforcing phases, which are then combined with nickel salts and a phosphorus source to prepare a uniformly dispersed composite plating solution. This solution is deposited on a pretreated steel substrate to form an amorphous nickel-phosphorus alloy coating, followed by gradient heat treatment to construct the target microstructure. This coating, through multi-phase synergy, enhances substrate adhesion and hydrogen barrier performance, showing promising industrialization prospects in hydrogen energy storage and transportation, and petrochemical equipment protection.

The invention provides a preparation method of an anti-oxidation coating from inside to outside, which comprises the following steps: A) preparing an MCrAlY alloy layer on the surface of a pretreated matrix, M being one or more selected from Ni, Co or Fe; b) spraying MCrAlY powder and nano ceramic powder on the surface of the MCrAlY alloy layer to obtain a nanocrystalline composite layer; c, the nanocrystalline composite layer is subjected to laser remelting and then cooled, and the anti-oxidation coating is obtained.The compact diffusion barrier layer is prepared through a controllable atmosphere spraying technology, is used for inhibiting easy-to-oxidize elements in a base body from migrating to the surface under the high-temperature service condition and is suitable for high-temperature components such as aero-engine blades and nuclear reactor components.

The invention provides a preparation method of a water-proof and oxygen-proof nanocrystal composite material, which comprises the following steps: atomizing and drying a solution I containing a nanocrystal precursor and a polymer to obtain nanocrystal composite particles, dispersing the nanocrystal composite particles in a colloidal solution, ultrasonically and uniformly mixing the nanocrystal composite particles with a solution II containing a water-proof and oxygen-proof polymer, and performing secondary atomizing and drying to obtain the water-proof and oxygen-proof nanocrystal composite material. And forming a polymer protective layer with water and oxygen barrier property on the surfaces of the nanocrystalline composite particles to obtain the water-proof and oxygen-proof nanocrystalline composite material. The nanocrystalline composite material can be dispersed in packaging base materials such as EVA and POE, has high photoelectric conversion efficiency, maintains long-term environmental stability, and remarkably prolongs the service life of a display device. According to the preparation method, the nanocrystalline composite material is prepared by adopting a secondary spray drying process, the destructive effect on the nanocrystalline material in a traditional liquid phase coating method is avoided, the second waterproof oxygen-barrier polymer layer can greatly improve the environmental stability of the nanocrystalline material, and meanwhile, the nanocrystalline material can be prepared with high efficiency and high material utilization rate; and the method is suitable for large-scale production.

The invention provides an amorphous-nanocrystalline composite structure high-entropy nitride film and a preparation method thereof, and relates to the technical field of film materials. A multi-arc ion plating technology and a high-power pulse magnetron sputtering technology are adopted, and the (Ti / TiN...) / (nc-HEAN / a-Si3N4) multi-layer nano composite structure high-entropy film is prepared by regulating and controlling the composition proportion and the structure. The nano-multilayer structure has the advantages that the crack deflects at an interface, the tip of the crack at the interface is passivated, and microcrack initiation and propagation caused by stress concentration are prevented. The nanocrystalline nc-HEAN high-entropy nitride is embedded in the amorphous a-Si3N4, so that a nanocrystalline / amorphous multiphase composite structure is formed. By means of a nano multilayer structure and a nanocrystalline / amorphous multiphase composite structure, the multilayer nano composite high-entropy nitride film with high hardness / high toughness is prepared so as to meet the high-performance application requirements of the modern industrial technology on cutters and grinding tools.

The invention is applicable to the technical field of metal material welding, and provides a duplex stainless steel pipe welding method which comprises the following steps: S1, performing transient eutectic liquid phase diffusion pretreatment on a groove, and forming a nanocrystalline composite activation layer rich in nickel, nitrogen and rare earth oxides in the groove in situ; s2, a microalloyed welding wire with specific components is adopted for welding, and the welding wire contains 0.8 wt%-1.5 wt% of Cu and 0.01 wt%-0.03 wt% of P which are cooperatively added; s3, after welding, interface excitation and high-temperature and high-pressure nitrogen directional penetration cooperative treatment is conducted; the pretreated nanocrystalline composite activation layer and Cu and P in the welding wire are subjected to a synergistic metallurgical reaction during welding, Ni-Cu-P clusters are generated, the phase boundary can be pinned, the structure can be refined, and a welding seam can be purified in situ; meanwhile, the nanocrystalline composite activation layer provides a high-speed channel for subsequent directional permeation of nitrogen atoms, so that a nitrogen-rich strengthening region is formed on the inner wall of the joint; according to the method, the weak area of the fusion line is fundamentally eliminated, homogenization and functional gradient of the joint structure performance are achieved, and the comprehensive performance is improved.

The invention discloses a preparation method of a full bio-based foaming material, which comprises the following steps: S1, dissolving 90-99 parts by weight of L-polylactic acid and 1-10 parts by weight of cellulose nanocrystal grafted D-polylactic acid in an organic solvent a, fully stirring, and desolventizing at 20-80 DEG C to obtain a polylactic acid / cellulose nanocrystal composite material; the length-diameter ratio of the cellulose nanocrystal is 15 to 30; s2, placing the polylactic acid / cellulose nanocrystalline composite material in a press vulcanizer for compression molding to obtain a sheet; and S3, placing the sheet in carbon dioxide gas, heating to a saturation temperature for saturation treatment, then cooling to a foaming temperature, and immediately releasing the pressure to normal pressure for foaming to obtain the full-bio-based foaming material. The full-bio-based foaming material prepared by the preparation method has excellent heat-insulating property and mechanical property.

The invention provides a preparation method of a nanocrystalline composite material with low cost and high performance. Iron-based nanocrystalline powder, FeNi powder and FeSiAl powder are mixed, pressing and heat treatment are carried out after resin insulation coating are carried out, the nanocrystalline composite material is obtained, in the process, through quality control over all the powder, resin insulation coating is carried out after inorganic coating is carried out on the powder, and cooperative control over two-step pressing and two-step heat treatment is carried out, so that the composite material is obtained. The nanocrystalline composite material which is low in cost, high in frequency, low in loss, high in magnetic conductivity and high in direct current bias is prepared, and the nanocrystalline composite material is suitable for high-frequency power electronic equipment in the fields of 5G communication, new energy automobiles, aerospace and the like.

The invention relates to the technical field of metal composite materials, in particular to a grain heterogeneous tungsten-copper composite material and a preparation method and application thereof. The method comprises the following steps that titanium carbide powder and a first part of tungsten powder are subjected to ball milling treatment, and W-TiC composite powder is obtained; the W-TiC composite powder and the first part of copper powder are subjected to ball milling treatment, and nanocrystalline composite powder is obtained; the remaining tungsten powder and the remaining copper powder are subjected to ball milling treatment, and coarse-grain composite powder is obtained; the nanocrystalline composite powder and the coarse grain composite powder are subjected to ball milling treatment, and mixed powder is obtained; and the mixed powder is sintered, and the grain heterogeneous tungsten-copper composite material is obtained. According to the invention, a grain heterostructure composed of a W-phase nanocrystalline area and a coarse grain area is successfully constructed through a step-by-step ball milling-mixed sintering process. By means of the structure, the composite material can still maintain excellent plasticity and high conductivity while having high yield strength.

The application discloses a kind of high-conductivity insulation halogen-free fireproof special cable and its preparation method and application, belong to cable manufacturing technical field.Cable is from inside to outside by composite conductor layer, inner wrapping tape layer, inner insulation layer, outer insulation layer, shielding layer, outer wrapping tape layer and sheath layer composition;Composite conductor layer is formed by the stranding of multiple composite conductor filaments;Composite conductor filament is from inside to outside by three layers, respectively as: core copper, inner surface layer and outer surface layer;Inner surface layer is 18-32nm thick amorphous-nanocrystalline composite copper layer;Outer surface layer is 35-78nm thick graphene layer.The cable of the application has high conductivity, strong insulation and fire resistance, non-toxic fire resistance and other characteristics.The preparation method of the application significantly improves the conductivity, mechanical strength and high-temperature stability of the conductor through thermal-magnetic-optical multi-field coupling.

The invention belongs to the technical field of photoelectric thin film materials, and particularly relates to a full-spectrum transparent conductive thin film material and a preparation method thereof.The thin film material is of a quasi-continuous homologous nanocrystalline enhanced amorphous composite structure and specifically comprises a transparent substrate serving as an amorphous phase, the chemical component of an amorphous area of the transparent substrate is CuSe < 1 + x >, x is 0.8-1, and the chemical component of the transparent substrate is CuSe < 1 + x >, the components of the whole amorphous region are uniform and present an amorphous structure; the invention relates to a copper-based composite material which is characterized in that the copper-based composite material serves as a conductive reinforcing phase of a crystal phase, a crystal region of the conductive reinforcing phase is composed of nanocrystal grains with a space group of Fm-3m, the chemical component of the nanocrystal grains is CuSe (1-y), and y is equal to 0.4-0.6. According to the invention, a copper selenide material is used as a conductive material, so that the material has good transmissivity in a full spectrum and has the characteristic of high conductivity; the quasi-continuous homologous nanocrystalline composite film is formed by carrying out magnetron sputtering, thermal annealing and other post-treatment methods on a copper selenide target material, and integration of full-wave band transparency and conductivity is achieved.

The application discloses a vacuum diffusion welding pressure plate with a water cooling structure, which comprises an upper plate and a lower plate, the upper plate and the lower plate are integrally formed into the welding pressure plate through sintering, a water cooling channel is arranged at the top of the lower plate, the material of the welding pressure plate is Mo-Si-B alloy, the bottom of the lower plate is provided with an array type micro-protrusion, the protrusion height is 50-80 microns, the protrusion diameter is 100-150 microns, and the center distance is 200-250 microns, and the preparation method of the welding pressure plate comprises the following steps: S1, the Mo-Si-B alloy composition is as follows in terms of atomic percentage: Mo is 10-15, Si is 8-12, B is 1-3, and the additive is 0.5-1.5 wt% ZrO2 or Y2O3 as a grain boundary strengthening phase; and S2, mechanical alloying: the Mo powder, the Si powder, the B powder, the steel powder and the additive are placed in a high-energy ball milling tank and mixed under the protection of argon gas to prepare a nanocrystalline composite powder.

The application discloses a kind of detection food aldehyde flavor substance perception gas sensitive sensing electrode and its preparation method and application, it is related to gas sensitive sensing and food detection technical field, to solve the technical problem of low sensitivity, poor selectivity and insufficient stability of existing gas sensitive electrode to food aldehyde flavor substance perception.The application includes: (S1) preparation Co 2+ @ZIF-8 precursor;(S2) pyrolysis conversion into nanocrystalline composite material;(S3) MXene-NH2, with carboxylated composite material, form complex by amidation reaction;(S4) the complex is heated first, then keep warm, finally annealing, obtain ternary composite sensitive material;(S5) ternary composite sensitive material is coated on interdigital electrode, after drying, it is obtained.The gas sensitive sensing electrode obtained by the application is used for high sensitivity, high selectivity perception of aldehyde flavor substance in food, and is suitable for food quality and safety monitoring and flavor evaluation analysis.

The invention discloses a nanocrystalline composite ceramic insulating material and a preparation method thereof, and belongs to the field of nanocrystalline ceramic material preparation. Raw materials of the catalyst comprise the following components by mole percent: 40-50% of SiO2; 30%-38% of CaCO3 (calcium carbonate); 13% to 18% of Na2CO3; 0.5 to 2.5 percent of TiO2; zrO2: 0.5% to 2.5%; 1 to 3 percent of Al2O3; and 0.5 to 4.5% of K2O. The preparation method comprises the following steps: weighing the raw materials according to the proportioning requirement, fully mixing the raw materials, and carrying out ball milling treatment; keeping the temperature of the mixture at 850-950 DEG C for more than 2 hours, then keeping the temperature at the temperature not lower than 1450 DEG C for 60-90 minutes, then pouring the mixture into a preheated brass mold, and keeping the temperature at 500-550 DEG C and annealing for more than 10 hours; heat treatment is carried out in an air atmosphere through a two-step method, heat preservation is carried out at the temperature of 600-650 DEG C for a certain time, then heat treatment is carried out at the temperature of 650-700 DEG C, and the temperature interval between the heat treatment and the heat treatment is 50-100 DEG C. The nanocrystalline composite ceramic insulating material disclosed by the invention has more excellent mechanical strength and dielectric property, and is of great significance in promoting a power transmission and transformation system to develop towards a direction of higher voltage, longer distance and more reliability.

The invention discloses a high-conductivity insulating halogen-free fireproof special cable and a preparation method and application thereof, and belongs to the technical field of cable manufacturing. The cable is composed of a composite conductor layer, an inner belting layer, an inner insulating layer, an outer insulating layer, a shielding layer, an outer belting layer and a sheath layer from inside to outside. The composite conductor layer is formed by twisting a plurality of composite conductor monofilaments; the composite conductor monofilament is composed of three layers from inside to outside: core copper, an inner surface layer and an outer surface layer. The inner surface layer is an amorphous-nanocrystalline composite copper layer with the thickness of 18-32 nm; and the outer surface layer is a graphene layer with the thickness of 35-78nm. The cable has the characteristics of high conductivity, strong insulation and fire resistance, no toxicity, fire resistance and the like. According to the preparation method disclosed by the invention, the conductivity, the mechanical strength and the high-temperature stability of the conductor are remarkably improved through thermal-mechanical-magnetic-optical multi-field coupling.

The invention relates to the field of clothing accessories, in particular to a preparation method of low-magnetism metal zipper teeth. The preparation method provided by the invention comprises the following steps: mixing Fe-based alloy powder and Y2O3 nanoparticles to obtain pre-alloyed powder; then the pre-alloyed powder is prepared into spherical powder through a plasma rotating electrode atomization method; preparing the spherical powder into a zipper tooth blank through a selective laser melting process; then the zipper tooth blank is sequentially subjected to pulsed magnetic field treatment and microwave rapid annealing treatment, and annealed zipper teeth are obtained; and finally, titanium nitride ion beams are used for conducting surface modification treatment on the annealed zipper teeth, an amorphous-nanocrystalline composite layer is formed on the surfaces of the annealed zipper teeth, and the zipper teeth are obtained. The phase change suppression and magnetic field compensation synergistic process is adopted, the powder metallurgy pre-alloying technology and the pulsed magnetic field annealing technology are originally fused, the magnetic anisotropy field, the resistivity and the friction coefficient can be effectively reduced, and the grain refining effect and the tensile strength can be improved.

The application discloses a preparation method of a green and environment-friendly amorphous nanocrystalline composite wave-absorbing film, which comprises the following steps: adding an absorbent into deionized water, and performing ultrasonic dispersion to obtain an absorbent dispersion liquid; diluting water-based polyurethane emulsion with deionized water, and uniformly stirring to obtain a base emulsion; dropwise adding the absorbent dispersion liquid into the base emulsion, and mixing under the joint action of ultrasonic and mechanical stirring to obtain a film-forming precursor suspension; pouring the film-forming precursor suspension into a mold, drying at 70-90 DEG C for 12-24 h to obtain a preformed dry film; and hot-pressing the preformed dry film at 170-190 DEG C and under a pressure of 4-6 atm for 3-5 min, demolding after cooling to obtain the green and environment-friendly amorphous nanocrystalline composite wave-absorbing film. The preparation method is simple, green and environment-friendly, the filler is uniformly dispersed, the interface is firmly combined, and an amorphous nanocrystalline composite wave-absorbing film with a high bandwidth-thickness ratio can be prepared.

The present application relates to a kind of anode catalysts for alkaline system direct urea fuel cell, it is with nickel salt, H3BO3 and PVP dispersed in water heating reaction preparation precursor, then under inert atmosphere calcination obtained, by nitrogen-containing carbon material wrapped elemental nickel / nickel oxide / nickel boride nanocrystalline composite material.The present application introduces non-metallic boron and PVP carbon material, after calcination, active substance nickel / nickel oxide / nickel boride replaces traditional noble metal, by forming metal boride and oxide to adjust catalyst electronic structure, improve the catalytic activity and electrode conductivity of catalyst, with it as the anode catalyst for alkaline system direct urea fuel cell, with excellent electrochemical reaction activity.

The invention provides a Cu composite MAX phase conductive composite coating as well as a preparation method and application thereof, and relates to the technical field of functional coating materials. The conductive composite coating is of a uniform nanocrystalline structure, and the conductive composite coating comprises an MAX phase and a Cu-Al alloy phase. Compared with the prior art, the preparation method has the advantages that a uniform nanocrystalline composite structure taking the MAX phase as a base and the Cu-Al phase as a reinforcement is constructed, so that synergistic improvement of multiple key properties is successfully realized. The MAX phase provides high hardness, arc ablation resistance and fusion welding resistance of the coating, and the introduction of the Cu-Al phase significantly enhances the electrical and thermal conductivity and improves the lubrication and wear resistance. The two-phase structure is tightly combined on the nanoscale, so that the coating has excellent conductivity, mechanical strength and tribological performance, the comprehensive performance of the coating is far better than that of a single-phase coating, and the service life of an electric contact part under the severe working condition is remarkably prolonged.

The utility model relates to gluing equipment technical field, concretely relates to a kind of non-crystalline nanocrystalline composite strip self-adhesion coating's coating mechanism, it includes: base, the base top is fixedly connected with the mounting plate being set as L shape, the mounting plate is provided with the glue storage box for storing coating, the glue outlet is provided with glue roller in the glue storage box bottom, the mounting plate inside is provided with three auxiliary rollers for assisting non-crystalline nanocrystalline composite strip conveying, glue scraping assembly, including two fixedly connected in the mounting plate inside shell, the shell inside is slidably connected with scraper, the utility model is provided, when the amount of glue on scraper reaches certain amount and needs to be cleaned during non-crystalline nanocrystalline composite strip gluing operation, control servo motor works, the height of two scrapers is switched, without closing gluing equipment, to ensure non-crystalline nanocrystalline composite strip gluing efficiency.

The invention provides a method for preparing a SiC-based nanocrystalline multiphase ceramic material from a liquid silicon-carbon precursor or a derivative thereof, and belongs to the technical field of ceramic material preparation. Comprising the following steps: mixing liquid polycarbosilane or a derivative thereof, a reinforcement and a sintering aid, heating under an oil bath condition, and continuously stirring to form a gel-state mixture; the obtained gel-state mixture is subjected to high-temperature curing treatment and then subjected to thermal cracking in an inert atmosphere, and amorphous SiC-based ceramic composite powder is obtained; and sintering the obtained amorphous SiC-based ceramic composite powder at a high temperature for a short time to obtain the material. According to the preparation method disclosed by the invention, through a combination method of precursor gelation compounding and rapid sintering in-situ crystallization coating, the problems that a reinforcement is difficult to uniformly disperse and impurities are easy to introduce to influence the densification effect in a traditional mixing method such as ball milling and the like are effectively solved, and nanocrystallization, densification and matrix-reinforcement phase interface strengthening of the material are synchronously realized; the high-strength and high-toughness SiC-based nanocrystalline composite ceramic is prepared.

The invention belongs to the field of amorphous nanocrystalline composite coatings, and discloses an anti-corrosion wear-resistant high-toughness core-shell structure amorphous nanocrystalline composite coating and a preparation method thereof.The anti-corrosion wear-resistant high-toughness core-shell structure amorphous nanocrystalline composite coating comprises an amorphous matrix phase and a nanocrystalline phase, the volume ratio of the amorphous matrix phase to the nanocrystalline phase is 80-90%, the volume ratio of the nanocrystalline phase to the nanocrystalline phase is 10-20%, the nanocrystalline phase is composed of particles of a crystalline state core-shell structure, and the volume ratio of a shell layer in any particle is 70-80%; the volume ratio of the core part is 20%-30%, the shell layer simultaneously comprises a Ni solid solution phase and a Mg6Cu16Si7 configuration intermetallic compound phase, the core part is a Co2Si configuration intermetallic compound phase, the hardness of the amorphous matrix phase is between the hardness of the shell layer and the hardness of the core part, and the hardness of the core part is greater than that of the shell layer. The invention further discloses a method for preparing the coating in an ultra-high-speed laser cladding mode. The method solves the problem that a coating with comprehensive high corrosion resistance, excellent wear resistance and good plasticity and toughness cannot be prepared in the prior art.

The application discloses a kind of in-situ generation of rich alumina protective layer on the surface of rare earth magnesium alloy fast transient ultrasonic processing method and its application, belong to metal material surface engineering and modification technical field.Method includes: providing magnesium alloy workpiece containing aluminum and rare earth element, using ultrasonic tool head to workpiece surface in oxygen-containing environment Mechanical contact and high-frequency vibration irradiation;Through ultrasonic friction heat and the coupling effect of severe plastic deformation, induce surface layer aluminum element rapid diffusion and oxidation, in 5-15 seconds in-situ growth with alumina as main dense protective layer.The protective layer presents black, with amorphous-nanocrystalline composite structure of size increasing from surface to heart.This application does not need electrolyte and external heat source, process green environmental protection and extremely efficient, the obtained oxide layer and matrix form firm metallurgical bonding, significantly improve the surface hardness, wear resistance and corrosion resistance of magnesium alloy, suitable for industrialization online processing.

The invention discloses a SiN film for realizing super lubrication on the surface of engineering steel and a preparation method of the SiN film, and belongs to the field of surface engineering and tribology. According to the method, a HiPIMS / DC composite deposition technology is innovatively adopted, and the SiN film with a specific gradient structure, a uniform amorphous nanocrystalline composite phase and a narrow optimized residual stress window (-0.71-0.23 GPa) is successfully prepared on a GCr15 and other conventional engineering steel substrates only by accurately controlling the flow ratio of Ar to N2 to be 4: 1 + / -0.5 (optimally 4: 1). The film shows excellent comprehensive performance, the hardness is larger than or equal to 15 GPa, the obdurability is good (H / E is larger than or equal to 0.10), and stable super lubrication can be achieved under the action of PEGP lubricants (the friction coefficient is smaller than or equal to 0.01). According to the method, the inherent dependence of a super-lubrication technology on a Si3N4 ceramic friction pair is broken through, the intrinsic super-lubrication function is achieved on the surface of cheap engineering steel for the first time, and a brand new way for cooperatively regulating and controlling the stress performance friction behavior of a thin film structure through a single gas parameter is disclosed. The method is simple in process, stable in control, good in repeatability and low in cost, and a revolutionary surface technology solution is provided for performance jump of mechanical basic parts such as high-end bearings, hydraulic elements and precision dies.

The invention discloses a wireless power transmission device for an unmanned aerial vehicle, and the device comprises a receiving end, and the receiving end comprises a coupling coil which is formed by winding a Litz wire; a circuit module; the magnetic isolation structure adopts a ferrite-nanocrystalline composite laminated structure and is arranged between the coupling coil and the circuit module; and the aluminum nitride insulation radiator is arranged between the magnetic isolation structure and the circuit module, so that a preset buffer space is formed between the magnetic isolation structure and the circuit module. According to the embodiment of the invention, the wireless power transmission device of the unmanned aerial vehicle charges the battery of the unmanned aerial vehicle under high density and high efficiency, electromagnetic interference generated by a circuit structure on the unmanned aerial vehicle under the action of a high-frequency magnetic field and eddy-current loss generated on a metal structure of the unmanned aerial vehicle due to the action of magnetic field leakage are reduced, and the safety and reliability of the wireless power transmission process of the unmanned aerial vehicle are ensured.

The present disclosure relates to a nanocrystal composite includes a connected aggregate including a plurality of nanocrystal fragments connected to one another, each nanocrystal fragment having a main surface and an end surface, and nanoparticles supported on the connected aggregate. The plurality of nanocrystal fragments each have a flaky shape; the plurality of nanocrystal fragments have gaps between the main surfaces; and the gaps G are arranged so as to open to the outside of the connected aggregate. The nanoparticles have a metallic element different from that of the plurality of nanocrystal fragments; and a proportion of a visual field area of the nanoparticles with respect to a visual field area of the plurality of nanocrystal fragments is 2% or more and 50% or less.

The invention discloses a cobalt-based nanocrystal, a composite material and a preparation method and application of the cobalt-based nanocrystal and the composite material, and belongs to the technical field of photocatalytic materials. The preparation method of the cobalt-based nanocrystal comprises the steps that a cobalt precursor and oleylamine are mixed, then the temperature is increased to 180-280 DEG C, heat preservation is conducted, and the cobalt-based nanocrystal is obtained. The invention further provides the cobalt-based nanocrystal which is prepared by the preparation method. The invention further provides a composite material, and the composite material is obtained by modifying g-C3N4 with the cobalt-based nanocrystal. The invention also provides a preparation method of the composite material. The preparation method comprises the following steps: mixing the cobalt-based nanocrystalline dispersion liquid and g-C3N4 powder, and carrying out hydrothermal treatment to obtain an intermediate product; the intermediate product is subjected to annealing treatment at the temperature of 400-600 DEG C, and the composite material is obtained through annealing treatment. According to the composite material provided by the invention, the hydrogen production amount can be remarkably increased in the process of producing hydrogen by catalytically reforming PET (Polyethylene Terephthalate).

The application provides a high-permeability low-loss iron-based nanocrystalline magnetic powder core and a preparation method thereof. The preparation method of the nanocrystalline magnetic powder core comprises the following steps: dispersing a resin bonding agent in acetone, adding an iron-based amorphous powder, and stirring until the acetone is completely volatilized; adding a release agent after granulation and drying, and obtaining an amorphous magnetic powder core after pressing and curing; the molecular formula of the iron-based amorphous powder is Fe a Si b B c Cu d Nb e M f M is a combination of two or three of metal elements Mn, V and C; and the obtained amorphous magnetic powder core is subjected to vacuum annealing treatment to obtain a nanocrystalline magnetic powder core. The obtained iron-based nanocrystalline magnetic powder core can simultaneously improve the permeability and reduce the loss by optimizing the components, and the comprehensive performance is improved; the optimized components can improve the stability and reliability of the magnetic powder core, so that the magnetic performance of the magnetic powder core can be maintained stable in a long-term use process.