2570results about "Magnetic materials" patented technology

A double cold rolled non-oriented electrical steel sheet having a composition including: 0.0001%≤Carbon≤0.007%, 0.1%≤Manganese≤0.2%, 3.1%≤Silicon≤3.6%, 0.8%≤Aluminum≤1.1%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and can contain various optional elements. The remainder composition being iron and unavoidable impurities caused by processing, the microstructure is made of ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, is from 35% to 45% when calculated in accordance of Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.64 T to 1.66 T.

A double cold rolled non-oriented electrical steel sheet having a composition including, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.15%≤Manganese≤0.3%, 3.2%≤Silicon≤3.8%, 0.8%≤Aluminum≤1.1%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and can contain various optional elements. The remainder composition being iron and unavoidable impurities caused by processing, the microstructure is made of ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, less than 30% when calculated in accordance of Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.66 T to 1.69 T.

A non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%,, 0.15% ≤Manganese≤0.2%, 3%≤Silicon≤3.6%, 0.7%≤Aluminum≤1.3%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, with 3.85%≤Si+Al+Mn ≤5.5%, and can contain various optional elements, the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet being made of ferrite and including in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, of 35 to 55% when calculated in accordance with Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.635T to 1.670T.

A double cold rolled non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.1%≤Manganese≤0.3%, 3.1%≤Silicon≤3.8%, 0.6%≤Aluminum≤0.8%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and can contain various optional elements. The remainder composition is iron and unavoidable impurities caused by processing. The microstructure ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, of 40 to 50% when calculated in accordance with Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.66T to 1.7T.

The invention discloses a neodymium-iron-boron magnet with double main phases and light rare earth diffusion based on asymmetric cerium distribution and a preparation method, and relates to the technical field of neodymium-iron-boron magnets. The method comprises the steps that a diffusion matrix is prepared through a double-main-phase technology, in the double-main-phase technology, the components of a main-phase alloy and an auxiliary-phase alloy are RaCebFe100-a-b-c-dMcBd, R is PrNd alloy or Nd metal, M is at least one of Cu, Al, Zr, Co and Ga, the content of Ce in the main-phase alloy is larger than that of Ce in the auxiliary-phase alloy, then the upper surface and the lower surface of the diffusion matrix are coated with a diffusion source solution, and the diffusion matrix is obtained through heat treatment. Carrying out heat treatment and aging treatment to obtain a neodymium-iron-boron magnet; the diffusion source solution is formed by mixing a diffusion source and a solvent, and the diffusion source is (PrmNdn) aAlbCucZrdCoeMgf. The neodymium-iron-boron magnet obtained through the method has high residual magnetism and high coercive force at the same time, the diffusion efficiency of the diffusion source is high, and the rare earth utilization rate is increased.

A non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.15%≤Manganese≤0.25%, 3.2%≤Silicon≤3.8%, 0.7%≤Aluminum≤1.3%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and various optional elements. The remainder composition is iron and unavoidable impurities caused by processing. The microstructure is ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, less than 33% when calculated in accordance with Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.630T to 1.65T.

A non-oriented electrical steel sheet having a composition of the following elements, expressed in percentage by weight 0.0001%≤Carbon≤0.007%, 0.15%≤Manganese≤0.25%, 2.9%≤Silicon≤3.4%, 0.8%≤Aluminum≤1.1%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, with 3.85%≤Si+Al+Mn≤5.5%, and the following optional elements 0%≤Niobium≤0.1%, 0%≤Titanium≤0.1%, 0%≤Vanadium≤0.1%, 0%≤Chromium≤1%, 0%≤Molybdenum≤0.5%, 0%≤Tungsten≤0.1%, 0%≤Cobalt≤1%, 0%≤Arsenic≤0.05%, 0.001%≤Calcium≤0.01%, 0%≤Copper≤1%, 0%≤Nickel≤1%, 0%≤Boron≤0.05%, 0%≤Lead≤0.2%, 0%≤Tin≤0.2%, 0%≤Antimony≤0.2%, the remainder composition being composed of iron and unavoidable impurities caused by processing. The microstructure is made of ferrite and including in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses less than 25% and simultaneously having a magnetic polarization at 5000 A / m from 1.625 T to 1.690 T.

The invention discloses a neodymium iron boron magnet with a protective film and a manufacturing method thereof, and the manufacturing method specifically comprises the following steps: S1, pretreating a plurality of raw materials to ensure the purity and cleanliness of the raw materials; s2, the pretreated materials are mixed in proportion and smelted to prepare uniform neodymium-iron-boron alloy; s3, the smelted alloy is crushed, and particle powder meeting the requirement is prepared through jet mill equipment; s4, the powder is put into a mold, forming orientation is conducted through a magnetic field press, and the maximum residual magnetism is obtained; s5, performing high-temperature sintering on the molded magnet to improve the density and the magnetic performance of the molded magnet; s6, the sintered magnet is machined, and the needed size and shape are obtained; s7, carrying out pretreatment on the surface of the magnet, and carrying out aftertreatment after chemical nickel plating to ensure the quality of a plating layer; according to the method, the surface of the neodymium-iron-boron magnet is coated with a high-phosphorus chemical nickel layer in a plating mode, the magnet can be effectively prevented from being corroded by the external environment, and the service life of the magnet is prolonged.

The invention discloses an yttrium-rich neodymium-iron-boron magnet and a preparation method thereof, and belongs to the technical field of rare earth permanent magnet material preparation. The preparation method comprises the following steps: mixing yttrium-rich neodymium-iron-boron matrix alloy powder with grain boundary doped alloy powder containing Gd and / or Ho, and carrying out compression molding and sintering tempering treatment to obtain a first yttrium-rich neodymium-iron-boron magnet. According to the invention, the grain boundary doped alloy powder containing Gd and / or Ho is added into the yttrium-rich neodymium iron boron matrix alloy powder and then is sintered, so that a continuous and uniform non-magnetic thin-wall grain boundary phase structure is formed in the grain boundary, and the coercive force of the magnet is enhanced. Dy and / or Tb heavy rare earth element grain boundary diffusion is carried out based on the first yttrium-rich neodymium-iron-boron magnet after grain boundary modification, a second yttrium-rich neodymium-iron-boron magnet is obtained, the diffusion depth of Dy and / or Tb in the magnet can be increased, the utilization rate can be increased, the cost can be reduced, the coercivity of the magnet can be improved, and the adverse effect of Dy and / or Tb on residual magnetism can be reduced.

A non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.21%≤Manganese≤0.7%, 3%≤Silicon≤3.6%, 0.7%≤Aluminum≤1.3%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, with 3.85%≤Si+Al+Mn≤5.5%, and can contain various optional elements. The remainder composition being composed of iron and unavoidable impurities. The microstructure is ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, from 35% to 45% and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.63T to 1.66T.

The invention relates to a Fe-Si-Nb-B-Cu-Er amorphous alloy and a preparation method and application thereof, and belongs to the technical field of metal materials. The atomic percent expression of the Fe-Si-Nb-B-Cu-Er amorphous alloy disclosed by the invention is (Fe < 83 > Si < 3 > Nb < 4 > B < 9 > Cu < 1 >) < 100-x > Er < x >, wherein x is equal to 3.5 to 4.5. The rare earth element Er is added to optimize the soft magnetic performance of a Fe-Si-Nb-B-Cu amorphous alloy system, the coercive force of the Fe-Si-Nb-B-Cu amorphous alloy system is reduced, the preparation method is simple and easy to implement, and the Fe-based amorphous alloy with the excellent soft magnetization performance is obtained. The magnetization intensity of the amorphous alloy is sharply increased along with increase of a magnetic field under a low magnetic field and then gradually reaches saturation, typical soft magnetic performance is presented, and the amorphous alloy has wide application space in the field of magnetic materials.

The invention relates to a low-loss multiphase inductance material which comprises a magnet and a winding, coils adjacent to the winding are wound in the reverse direction, meanwhile, the magnet extends out to form electrodes, and the magnet comprises Fe-based nanocrystalline and iron powder. The invention has the effect of reducing the loss of the inductance material.

A high-abundance rare earth iron boron regenerated magnet and its preparation method belong to the field of rare earth permanent magnet materials and their recycling technology. After surface treatment, high-abundance Ce / La rare earth iron boron unqualified products and processing waste are subjected to coarse crushing and hydrogen explosion powdering; a Ce, La, Nd, and Pr rare earth alloy is prepared using a rapid solidification belt spinning technology and hydrogen explosion; the above two materials are ball milled, mixed, oriented, and pressed according to a certain proportion, and then sintered and heat treated to obtain a regenerated sintered magnet. The regenerated magnet prepared by the present invention has a waste material utilization rate of up to 95%, a low rare earth addition amount (0 to 5wt.%), and a light rare earth addition ratio (LaCe / NdPr) greater than 50%. The coercive force of the regenerated magnet is significantly improved, and the comprehensive magnetic properties are equivalent to or even higher than those of the original magnet. The present invention can accurately control the cheap light rare earths La and Ce to obtain a high-performance regenerated magnet, thereby realizing the high-value recycling of high-abundance rare earth permanent magnets.

The invention deals with a non-oriented electrical steel sheet having a composition of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.05%≤Manganese≤0.15%, 2.5%≤Silicon≤3.1%, 0.26%≤ Aluminum≤0.7%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and can contain various optional elements. The remainder composition is composed of iron and unavoidable impurities caused by processing. The microstructure of the steel sheet is made of ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, from 35% to 45% when calculated in accordance of Bertotti method.

The application relates to the technical field of integrally-formed inductors, in particular to a moisture-resistant soft magnetic composite material and a preparation method thereof and an integrally-formed inductor. The moisture-resistant soft magnetic composite material comprises the following components by mass: 100 parts of soft magnetic powder, 2-5 parts of a resin bonding agent and silicon resin, wherein the mass ratio of the silicon resin to the resin bonding agent is (0.3-2.0):100. The moisture-resistant soft magnetic composite material can avoid the phenomenon of explosion of the integrally-formed inductor during a reflow soldering process after moisture absorption.

A non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001% ≤ Carbon≤0.007%, 0.17%≤Manganese≤0.4%, 3%≤Silicon≤3.6%, 0.7%≤Aluminum≤1.3%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, with 3.85%≤Si+Al+Mn≤5.5% and can contain various optional elements the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet being made of ferrite and including in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, less than 25% when calculated in accordance of Bertotti method.

The invention discloses a high-temperature-resistant high-performance neodymium-iron-boron permanent magnet material and a preparation method thereof, and belongs to the technical field of neodymium-iron-boron permanent magnet materials. The material is prepared from neodymium iron boron magnetic powder, auxiliary metal, hyperbranched polyimide polymer modified nano zirconium oxide and a silane coupling agent through mixing, smelting, crushing, sintering, tempering, coating and curing. The hyperbranched polyimide polymer modified nano-zirconia is introduced into the components, so that the permanent magnet material has excellent thermal stability, the permanent magnet material can still keep stable magnetic performance and mechanical performance at high temperature, the attenuation resistance is good, the thermal demagnetization is low, and the interface bonding strength is improved after the nano-zirconia is modified by hyperbranched polyimide. The interfacial compatibility between the nano zirconium oxide and the polyimide is enhanced through click chemical reaction, and the interfacial bonding strength of the nano zirconium oxide on a neodymium iron boron matrix is improved. The three-dimensional branched structure of the hyperbranched polyimide can form physical crosslinking points in the material, so that the mechanical strength of the material is enhanced.

The invention relates to an MIM injection-molded samarium-iron-nitrogen magnet and a preparation process thereof.The preparation process comprises the steps that Nb is added into Sm2Fe17, a Nb nano-modified layer is formed through high-energy ball milling and heat treatment, then a degreased blank is obtained through a paraffin-polylactic acid-stearic acid ternary binder system with the mass ratio being 60: 30: 10 and gradient degreasing, and after the degreased blank is sintered, the MIM injection-molded samarium-iron-nitrogen magnet is obtained; nitriding treatment is carried out by adopting a three-stage process, and then the samarium-iron-nitrogen magnet with high magnetism is obtained after ultrasonic cleaning and other treatment.

A method for preparing a high-coercivity and high-thickness NdFeB magnet belongs to the technical field of rare earth permanent magnet material preparation and solves the technical problem of preparing high-thickness and high-coercivity NdFeB magnets. The method comprises the following steps: first, sequentially subjecting the NdFeB magnets to rapid solidification strip spinning, hydrogen crushing, airflow milling, magnetic field orientation molding, cold isostatic pressing, and vacuum low-temperature sintering to obtain a thin low-temperature sintered green body; second, subjecting the low-temperature sintered green body to a grain boundary thermal diffusion treatment after preparing a heavy rare earth element layer on the surface of the low-temperature sintered green body; third, subjecting the low-temperature sintered green body after the diffusion heat treatment to mechanical coarse crushing, hydrogen crushing, powder mixing, airflow milling, magnetic field orientation molding, and cold isostatic pressing to obtain a thick, high-thickness compact; finally, subjecting the high-thickness compact to vacuum low-temperature heat treatment, vacuum high-temperature sintering, and two heat treatments to obtain a high-coercivity and high-thickness NdFeB magnet. The method has a simple preparation process, significantly improves the coercivity of bulk NdFeB sintered magnets, and enables the magnets to have a high magnetic energy product.

The invention discloses a preparation method of Fe3O4 magnetic nanoparticles rich in carboxyl groups on the surface, which comprises the following steps: modifying Fe3O4 nanoparticles by using polyethylene glycol and silicon dioxide to enhance the dispersity and biocompatibility of the magnetic nanoparticles, modifying the surfaces of PEG-Fe3O4 coated SiO2 nanoparticles by using a silane coupling agent containing silane groups and unsaturated double bonds to obtain the magnetic nanoparticles rich in carboxyl groups on the surface, and modifying the magnetic nanoparticles rich in carboxyl groups on the surface by using a silane coupling agent containing silane groups and unsaturated double bonds to obtain the magnetic nanoparticles rich in carboxyl groups on the surface. Then octavinyl-POSS and double bonds on the surfaces of the nano particles are subjected to click modification to form an octahedral cage, 4-mercaptobenzoic acid and double bonds are further subjected to click modification, the surfaces of the nano particles are rich in carboxyl, and a polymer brush rich in carboxyl is constructed. Compared with a conventional streptavidin coupling method, a high-density polymer chain provides a large number of carboxyl active binding sites, so that the streptavidin coupling amount is increased, the antibody coupling rate is increased, and a solution is provided for applications such as high-sensitivity biological detection, efficient targeted drug delivery and stable immunoassay.

A non-oriented electrical steel sheet having a composition of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.09%≤Manganese≤0.15%, 2.5%≤Silicon≤3%, 0.1% ≤ Aluminum≤0.5%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and can contain various optional elements, the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet being made of ferrite and including in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, from 35% to 45% when calculated in accordance of Bertotti method.

The invention discloses a method for improving performance of rare earth permanent magnet sintered neodymium iron boron grain boundary diffusion, and belongs to the technical field of rare earth permanent magnet materials. The method comprises the steps that a low-melting-point metal layer and a diffusion layer containing heavy rare earth elements are sequentially formed on the surface of a clean sintered neodymium-iron-boron magnet, and then vacuum diffusion heat treatment and tempering treatment are conducted. Wherein the low-melting-point metal layer comprises at least one of copper, aluminum, gallium and tin or an alloy of the copper, the aluminum, the gallium and the tin; the heavy rare earth element comprises at least one of dysprosium, terbium, holmium and gadolinium. The low-melting-point metal layer is preferentially diffused and wets the grain boundary in the heat treatment process, heavy rare earth elements are promoted to be deeply and uniformly diffused towards the interior of the magnet along the grain boundary, so that a heavy rare earth-rich shell layer is formed outside main phase grains of the magnet, and the intrinsic coercive force is improved; meanwhile, the low-melting-point metal forms a strengthening phase at the grain boundary, the brittleness of the magnet after diffusion is improved, the surface corrosion phenomenon is restrained, and collaborative optimization of the comprehensive performance of the magnet is achieved.

A non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.18%≤Manganese≤0.5%, 3.1%≤Silicon≤3.8%, 0.7%≤Aluminum≤1.3%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, with 3.85%≤Si+Al+Mn≤5.5%, and can contain various optional elements the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet being made of ferrite and including in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, less than 34% when calculated in accordance with Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.60 T to 1.65 T.

The invention provides laser additive manufacturing of a FeCoNi-based soft magnetic high-entropy alloy multilayer alternate composite structure, and relates to the technical field of advanced manufacturing of soft magnetic high-entropy alloys. The laser additive manufacturing of the FeCoNi-based soft magnetic high-entropy alloy multi-layer alternate composite structure comprises the steps of respective preparation of three kinds of pre-alloyed powder, respective ball-milling preparation of two kinds of mixed powder, pretreatment of a base plate, argon protection in a forming bin and laser additive manufacturing. The FeCoNi-based soft magnetic high-entropy alloy multi-layer alternate composite structure is obtained through respective preparation of three kinds of pre-alloy powder, respective ball milling preparation of two kinds of mixed powder, pretreatment of a base plate, argon protection in a forming bin and laser additive manufacturing. The preparation method is simple and easy to operate, green and environment-friendly, low in cost, short in process, high in efficiency and beneficial to industrial large-scale production and popularization.

The invention discloses a samarium cobalt permanent magnet material and a preparation method thereof. The preparation method comprises the following steps: mixing samarium cobalt magnet powder with non-magnetic metal powder and / or non-magnetic metal oxide and / or non-magnetic metal compound powder according to a mass ratio to obtain powder A; the samarium-cobalt magnet powder and the powder A are mixed or laid, and powder B is obtained; the powder B is subjected to orientation forming, isostatic cool pressing, sintering, solid solution and aging heat treatment, and the samarium-cobalt permanent magnet material is prepared. By doping the non-magnetic metal powder and / or the non-magnetic metal oxide and / or the non-magnetic metal compound powder step by step, fine regulation and control of the microstructure of the samarium-cobalt magnetic material can be achieved, and the samarium-cobalt magnetic material with high magnetic performance and high mechanical performance has industrialization value; and meanwhile, the purpose of improving the mechanical property of the samarium-cobalt magnetic material at relatively low cost is achieved. The samarium-cobalt permanent magnet material provided by the invention comprises a heterostructure in which a fine grain region and a coarse grain region coexist, so that the samarium-cobalt permanent magnet material has excellent mechanical properties and magnetic properties at the same time.

The present disclosure provides a hydrogen decrepitation apparatus and a hydrogen recycling method. The hydrogen decrepitation apparatus comprises a hydrogen decrepitation furnace, a solid hydrogen-storage device, a first hydrogen recovery pipeline, a second hydrogen recovery pipeline, a hydrogen reuse pipeline, a first discharge pipe, a second discharge pipe, an inert gas pipeline, and a bypass pipeline. The hydrogen decrepitation apparatus enables hydrogen used in hydrogen decrepitation to be reused, thereby reducing costs of hydrogen decrepitation and lowering energy waste.

A non-oriented electrical steel sheet having a composition including the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.15%≤Manganese≤0.7%, 3%≤Silicon≤3.6%, 0.7%≤Aluminum≤1.3%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, with 3.85%≤Si+Al+Mn≤5.5%, and can contain various optional elements, the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet being made of ferrite and including in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, from 30 to 40% when calculated in accordance with Bertotti method.

The invention provides a neodymium iron boron magnet and a preparation method thereof, and belongs to the technical field of magnetic materials. The neodymium-iron-boron magnet comprises rare earth elements R, transition metal elements T, metal elements M and B elements, the R comprises Pr and Nd, the mass percent of the R is 29-32 wt%, the R comprises heavy rare earth elements Tb and Dy with the mass percent being 0-0.1 wt%, the M at least comprises Ti and Zr, and the sum of the mass percent of Ti and the mass percent of Zr is 0.1-0.6 wt%; t comprises Fe, or Fe and Co; the mass percent of the B is 0.84 wt%-0.94 wt%; the neodymium-iron-boron magnet is provided with a main phase and a grain boundary phase comprising a rare earth-rich phase, the proportion of the rare earth-rich phase to the grain boundary phase is 0.15-0.35, and the atom proportion of Pr in R in the rare earth-rich phase is 0.4-0.5. The neodymium-iron-boron magnet disclosed by the invention has excellent magnetic performance under the condition of no heavy rare earth or low heavy rare earth elements.

The invention provides a Y-rich rare earth permanent magnet and a preparation method and a magnetic performance improving method thereof, and the performance improving method comprises the steps: uniformly mixing to-be-diffused metal powder containing Dy and / or Tb elements with an organic solvent to obtain to-be-diffused alloy liquid; the alloy liquid to be diffused is attached to the surface of the Y-rich rare earth permanent magnet, and the Y-rich rare earth permanent magnet is placed in a vacuum sintering furnace; the Y-rich rare earth permanent magnet is subjected to grain boundary diffusion heat treatment through the vacuum sintering furnace, so that Dy and / or Tb elements are diffused into the surface layer of a main phase lattice of the Y-rich rare earth permanent magnet; and carrying out tempering treatment on the Y-rich rare earth permanent magnet. The problems that the coercive force of an existing Y-containing magnet is difficult to effectively improve, and residual magnetism is easily reduced can be effectively solved.

The invention belongs to the field of magnetic materials. The invention provides a preparation method of a rare earth permanent magnet, which comprises the following steps: weighing rare earth magnetic powder, adding a binder solution, uniformly mixing, and drying until a solvent is completely volatilized to obtain bonded magnetic powder; the bonded magnetic powder is placed in a die cavity of a constant-temperature die for heat preservation and preheating; an inner cavity of the constant-temperature mold is vacuumized to form a vacuum environment, and gas adhering to gaps of the magnetic powder is exhausted; applying a magnetic field to the mold, forming an oriented magnetic field in the mold cavity, arranging easy magnetization axes of the magnetic powder along the direction of the oriented magnetic field, and applying pressing force to obtain a mold pressing blank; and heating and curing the molded green body to obtain the rare earth permanent magnet. The rare earth permanent magnet prepared through the preparation method has high compactness, the residual magnetism and the maximum magnetic energy product capacity of the permanent magnet are improved, rare earth magnetic powder is prevented from being oxidized, and the coercive force of the permanent magnet is remarkably improved.