254 results about "Iron nitride" patented technology

A spherical or ellipsoidal iron nitride magnetic powder having a core comprising iron nitride including a Fe₁₆N₂ phase as a primary phase and an outer layer containing yttrium (Y) and aluminum (Al), in which an average particle size r of the iron nitride magnetic powder is 20 nm or less, an average diameter d of the core is 4 to 10 nm, and a ratio of r to d (r/d) is 2 to 3, and average content of yttrium and aluminum in the outer layer are from 0.9 to 5 atomic % and from 30 to 50 atomic %, respectively, each based on the total number of iron atoms in the iron nitride magnetic powder, and standard deviations of the contents of yttrium and aluminum are 0.6 atomic % or less and 17 atomic % or less, respectively.

The invention discloses a nano silicon nitride and boron nitride reinforced titanium carbonitride based cermet. A reinforced phase is added into a base material having a main phase of titanium carbonitride Ti(C, N) and a binder phase of nickel and cobalt metals, is at least one of nano silicon nitride and nano boron nitride, and is 0.5 to 2.5 volume percent of the base material. The preparation method comprises the following process flows: preparing raw material powder containing the nano silicon nitride and/or nano boron nitride; mixing; adding a forming agent; performing wet grinding; sieving; drying and granulating; performing compression molding; sintering in nitrogen; and obtaining the cermet. The cermet has the advantages of high hardness, high strength and high toughness, and can be widely applied to middle and low carbon steel and low alloy steel high-speed cutting tool materials; and the preparation process is easy to control and is suitable for large-scale industrial production.

The invention discloses a preparation method for core-shell type carbon-coated iron nitride nano-composite particles and the application of the core-shell type carbon-coated iron nitride nano-composite particles, and belongs to the field of nano-material preparation technologies and application. The method is characterized by comprising the following steps of: automatically controlling direct current arc hydrogen plasma equipment to evaporate bulk iron raw materials, and simultaneously introducing methane and argon according to a certain proportion to obtain carbon-coated iron nano-particle precursors; and performing nitriding thermal treatment on the precursors in the ammonia atmosphere of 400 DEG C for 3 to 4 hours to obtain the carbon-coated iron nitride nano-composite particles. A lithium ion battery cathode prepared from the carbon-coated iron nitride nano-composite particles which serve as active substances has the first reversible specific capacity of 550mAh/g and high cycle stability. The method and the application have the advantages that: the carbon-coated iron nitride nano-composite particles prepared by the low-temperature nitriding of the in-situ synthesized carbon-coated iron nano-particle precursors have high lithium intercalation/de-intercalation capacity density and cycle stability; the raw materials are low in cost; a process is simple; the carbon-coated iron nitride nano-composite particles can be prepared in large scale; and industrial production requirements are met.

The present invention relates to a nitrogen-doped graphene-iron-based nanoparticle composite catalyst and a preparation method thereof, wherein the catalyst is a complex of nitrogen-doped graphene and iron-based nanoparticles (including metal iron and iron nitride). The main preparation process comprises: carrying out a reaction of a graphene oxide aqueous solution and a reducing agent (hydrazine hydrate or sodium borohydride) for 1 h under an oil bath to obtain reduced graphene oxide; mixing the reduced graphene oxide aqueous solution and an iron salt, completely stirring, and carrying out freezing drying to obtain a reduced graphene oxide-iron salt aerogel precursor; and carrying out a high temperature heat treatment under a mixed atmosphere of ammonia gas and an inert gas to obtain the nitrogen-doped graphene and iron-based nanoparticle complex. Compared with the commercial platinum-carbon catalyst, the composite non-precious metal catalyst of the present invention has advantages of simple preparation process, low cost, high oxygen reduction catalysis activity, good methanol tolerance and the like, and can be used for fuel cells, lithium-air batteries and other oxygen reduction catalysis reaction systems.

The invention discloses polyaniline coated composite powder and a preparation method thereof. The composite powder comprises three parts, namely a core layer made of a carbon material, an interlayer made of monomer iron nano particles and iron nitride, and a coating layer made of a polyaniline thin film. The preparation method comprises the following synthesis steps: allowing the carbon material to fully absorb solution of ferric nitrate, and coating the monomer iron particles and the iron nitrate by hydrogen reduction and amination respectively; and finally, coating the polyaniline on the outside layer of the product of the amination by using in-situ polymerization technology, and thus obtaining the polyaniline coated composite powder. The powder has both the conductive and anticorrosionperformance of the polyaniline and the magnetic and catalytic performance of iron magnetic particles; the raw materials of the composite powder are widely available and the process flow of the composite powder is simple; and the composite powder has a bright application prospect in fields of electromagnetic wave shielding, metal corrosion resistance, treatment of refractory waste water, plastic rubber additive and the like.

The invention discloses a cobalt/nitrogen-codoped nitrogen-carbon-material-carrier-carried nano nickel iron nitride composite material. The composite material uses a cobalt/nitrogen-codoped nitrogen carbon material as the carrier, and iron nickel nitride nanoparticles are carried in situ on the surface of the cobalt/nitrogen-codoped carbon material. The preparation method comprises the following steps: protecting a zeolite imidazate framework structure material precursor by using silicon dioxide to obtain the high-dispersity carbon-base nanoparticle material, and growing nickel iron hydrotalcite in situ on the carbon material, and calcining to obtain the cobalt/nitrogen-codoped nitrogen-carbon-material-carrier-carried nano nickel iron nitride composite material. The cobalt/nitrogen-codoped nitrogen-carbon-material-carrier-carried nano nickel iron nitride composite material has excellent activity in catalyzing oxygen redox reaction, and can be used as a high-efficiency zinc-air battery negative pole material.

A permanent magnet may include a Fe16N2 phase constitution. In some examples, the permanent magnet may be formed by a technique that includes straining an iron wire or sheet comprising at least one iron crystal in a direction substantially parallel to a <001>; crystal axis of the iron crystal; nitridizing the iron wire or sheet to form a nitridized iron wire or sheet; annealing the nitridized iron wire or sheet to form a Fe16N2 phase constitution in at least a portion of the nitridized iron wire or sheet; and pressing the nitridized iron wires and sheets to form bulk permanent magnet.

A nitrided steel member including an iron nitride compound layer formed on a surface of a steel member having predetermined components, wherein: in X-ray diffraction peak intensity IFe₄N (111) of a (111) crystal plane of Fe₄N and X-ray diffraction peak intensity IFe₃N (111) of a (111) crystal plane of Fe₃N, which are measured on a surface of the nitrided steel member by X-ray diffraction, an intensity ratio expressed by IFe₄N (111)/{IFe₄N (111)+IFe₃N (111)} is 0.5 or more; Vickers hardness of the iron nitride compound layer is 900 or less, Vickers hardness of a base metal immediately under the iron nitride compound layer is 700 or more, and a difference between the Vickers hardness of the iron nitride compound layer and the Vickers hardness of the base metal is 150 or less; and a thickness of the iron nitride compound layer is 2 to 17 μm.

An iron nitride magnetic powder comprised primarily of Fe₁₆N₂ phase is characterized in that its coercive force Hc is 200 KA/m or greater and bulk switching field distribution BSDF is 2 or less. The magnetic powder can be produced by allowing a nitriding reaction of Fe particles with a nitrogen-containing gas for producing nitrided particles of primarily Fe₁₆N₂ phase to proceed under an increased pressure of 0.1 MPa or greater. The enhanced properties of the iron nitride magnetic powder make it suitable as a magnetic material for high-density magnetic recording media.

The disclosure describes magnetic materials including iron nitride, bulk permanent magnets including iron nitride, techniques for forming magnetic materials including iron nitride, and techniques for forming bulk permanent magnets including iron nitride.

The present invention provides ferromagnetic iron nitride particles, in particular, in the form of fine particles, and a process for producing the ferromagnetic iron nitride particles. The present invention relates to a process for producing ferromagnetic iron nitride particles, comprising the steps of mixing metallic iron obtained by mixing at least one compound selected from the group consisting of a metal hydride, a metal halide and a metal borohydride with an iron compound, and then subjecting the obtained mixture to heat treatment, with a nitrogen-containing compound; and then subjecting the resulting mixture to heat treatment, in which a reduction step and a nitridation step of the iron compound are conducted in the same step, and the at least one compound selected from the group consisting of a metal hydride, a metal halide and a metal borohydride is used as a reducing agent in the reduction step, whereas the nitrogen-containing compound is used as a nitrogen source in the nitridation step.

The invention discloses a dendritic iron nitride powder and a preparation method thereof. The microstructure of the dendritic iron nitride powder has anisotropy, is in a dendritic shape, and is composed of a micron-scale trunk structure and a nano-scale branch structure. The dendritic iron nitride powder is composed of a gamma'-Fe4N or epsilon-Fe3N single phase, or any two or more of gamma'-Fe4N, epsilon-Fe3N and Fe. The length of the micron-scale trunk structure is 3-10 mu m, the length of the nano-scale branch structure is 200nm-2 mu m, and the diameter of the branch structure is 50-400nm. Dendritic ferric oxide used as a precursor is subjected to a reduction nitriding one-step process to obtain the dendritic iron nitride powder. The iron nitride powder can implement special optical, electric, magnetic, catalytic and other physicochemical properties which can not be implemented by the common spherical iron nitride powder, and especially has important application value in the field of stealth materials.

The invention relates to a thin-film material and a preparation method thereof, in particular to an iron nitride thin-film material which can be applied to a magnetic sensitivity active layer of Hall elements and a preparation method thereof. The general formula of the nanocrystal iron nitride thin-film material is FexN, wherein x is the atom number ratio between the iron and the nitrogen contained in the material and x is larger than 2 and less than 4; the thickness of the thin-film is between 4 nanometers and 400 nanometers; compared with the traditional thin-film made of semiconductor materials and particles, the nanocrystal iron nitride thin-film has the advantages of low resistivity, wide operating temperature range, excellent linearity and small volume, and simple preparation process and low cost, thus having a wide range of application prospect in the fields of aviation, astronavigation, military and the like.

A flocculant, according to embodiments of the present disclosure, includes a core nanoparticle and at least one positively charged functional group on a surface of the core nanoparticle. The nanoparticle may comprise a silica, alumina, titania, iron oxide, iron nitride, iron carbide, or a carbon-based nanoparticle. The flocculant may be used, in a method of bitumen recovery, to neutralize and agglomerate bitumen droplets and/or mineral particles derived from oil sands ore. The bitumen droplets agglomerate about the core nanoparticle of the flocculant to form bitumen flocs, while the mineral particles agglomerate about the core nanoparticle of the flocculant to form mineral flocs. The buoyant bitumen flocs may then separate from the dense mineral flocs to enable high-yield recovery of bitumen from oil sands.