3615results 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.

The invention relates to the field of neodymium iron boron magnetic materials, in particular to a high intrinsic coercive force neodymium iron boron magnetic material and a preparation method thereof, and the high intrinsic coercive force neodymium iron boron magnetic material comprises the following raw materials in parts by weight: 52.5-57.2 parts of PrNd, 105-115.3 parts of Nd, 9.0-10.3 parts of B, 15-35 parts of Tb, 70-80 parts of Dy, 10-25 parts of Co and 650-680 parts of Fe. The two rare earth elements Tb and Dy are added into the neodymium-iron-boron magnetic material, so that the magnetocrystalline anisotropy field of the crystal is remarkably enhanced, and the intrinsic coercive force of the neodymium-iron-boron magnetic material is greatly improved.

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.

The invention discloses a production method of a high-performance sintered neodymium-iron-boron magnet. The production method comprises the steps of rapid quenching flaking, hydrogen decrepitation mixing, magnetic field forming, multi-stage treatment and composite coating. A nanocrystalline sheet is prepared through a rapid quenching technology, and uniform distribution of a grain boundary phase and rare earth elements is achieved through hydrogen decrepitation and material mixing; forming in a strong magnetic field and applying high pressure to improve the orientation degree; through high-temperature sintering, medium-temperature annealing and low-temperature aging treatment, magnet densification, grain boundary phase reconstruction and a magnetic domain structure are optimized; and finally, the corrosion resistance is improved by adopting a composite coating. The high-performance sintered neodymium-iron-boron magnet produced by the method comprises a main phase alloy, a grain boundary phase additive and a rare earth supplementary phase. Through low-oxygen nanocrystal preparation, grain boundary coordinated regulation and green process integration, compatibility of high performance, low cost and environmental protection is realized, and sustainable development of the rare earth permanent magnet material is promoted.

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.

The invention discloses a preparation method of low-loss high-saturation iron-nickel soft magnetic powder. Comprising the following steps of S1, alloy smelting and S2, atomization. S3, carrying out ball milling treatment; s4, annealing treatment; s5, carrying out surface coating; the low-loss high-saturation iron-nickel soft magnetic powder is prepared from the following raw materials in percentage by weight: 77.6%-78.2% of electrolytic nickel, 21.4%-22.3% of electrolytic iron and 0.1%-1% of an additive, the performance of the iron-nickel soft magnetic powder and a magnetic powder core prepared by the process is improved in multiple aspects, and the iron-nickel soft magnetic powder has great application advantages.

A non-oriented silicon steel for a high-speed motor and a manufacturing method therefor. The chemical components of the non-oriented silicon steel for a high-speed motor are as defined in the description, wherein the thickness of a finished product is 0.20-0.30 mm, and the grain size of the finished product is 80-100 μm. The manufacturing method for the non-oriented silicon steel for a high-speed motor comprises: performing smelting and casting into a continuous casting billet, and performing cooling, heating, hot rolling, normalizing, pickling, cold rolling, annealing and coating treatment on the continuous casting billet.

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.

The present invention discloses a medium-high performance neodymium iron boron and a preparation method thereof. Through the master-slave phase double alloy process, the master phase alloy is cerium iron boron with a low total rare earth content, and the slave phase is a neodymium iron boron alloy with a high total rare earth content, avoiding the entry of light rare earths in the master phase into the grain boundaries, while the surplus rare earths in the slave phase enter the grain boundaries and are recombined into rare earth-rich phases. The prepared magnet is processed into a thin magnetic sheet, and a low-melting-point HReM alloy is magnetron sputtered, realizing low-temperature grain boundary diffusion. This alloy improves the grain boundary wettability and also improves the fluidity of the rare earth-rich phase, enabling the cerium-containing neodymium iron boron master and slave phase grains to be quickly isolated during grain boundary diffusion. The low-temperature diffusion avoids the replacement of the diffused heavy rare earths by praseodymium, neodymium, and cerium elements, inhibits the exchange coupling between cerium iron boron grains, and makes the heavy rare earths free in the grain boundaries or interact with the rare earth-rich phase to form a core-shell structure on the surface layer of the master phase grains, enabling the rare earth-rich phase to be continuously and uniformly distributed, effectively enhancing the effectiveness of the grain boundary diffusion of heavy rare earth elements in improving the intrinsic coercivity of the cerium-containing magnet.

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 and a method for regulating and controlling the grain size and the grain size distribution of a coarse grain layer of the neodymium-iron-boron magnet, and particularly relates to the technical field of neodymium-iron-boron magnet material preparation. Collecting a local temperature change rate and a stress change rate in real time in a sintering temperature rise and heat preservation stage; triggering coarse grain layer structure evolution evaluation according to the monitoring data, and extracting a feature data set; a diffusion coupling non-uniformity index and a grain boundary migration tensor index are calculated based on the feature data set, a machine learning model is input, a coarse grain layer abnormal risk level is output, and sintering process parameters are dynamically adjusted according to the coarse grain layer abnormal risk level; according to the method, the abnormal evolution of the coarse grain layer is dynamically sensed by monitoring local temperature and stress changes in real time, the abnormal risk level of the grain size of the coarse grain layer is intelligently predicted based on the characteristic data set, abnormal growth of coarse grains is inhibited in time, and the microstructure consistency and service performance stability of the neodymium-iron-boron magnet are improved.

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.

Disclosed in the present application are a method for strengthening a neodymium-iron-boron magnet by means of grain boundary diffusion, and a grain-boundary-strengthened neodymium-iron-boron magnet. The method comprises: applying a first diffusion source to a surface of a neodymium-iron-boron magnet, and performing a low-temperature grain boundary diffusion treatment; applying a second diffusion source to the surface of the neodymium-iron-boron magnet that has been subjected to the low-temperature grain boundary diffusion treatment, and performing a medium-temperature grain boundary diffusion treatment; applying a third diffusion source to the surface of the neodymium-iron-boron magnet that has been subjected to medium-temperature grain boundary diffusion treatment, and performing a high-temperature grain boundary diffusion treatment, wherein the contents of heavy rare earth elements in the first diffusion source, the second diffusion source and the third diffusion source gradually increase; and finally, performing an annealing treatment, so as to obtain a grain boundary-strengthened neodymium-iron-boron magnet. In the present application, by means of multiple grain boundary diffusion treatments in which the content of heavy rare earths is regulated and controlled, targeted adjustments are made to the microstructure inside the magnet, the utilization rate of heavy rare earths is effectively increased, and the coercive force of the magnet is enhanced; and the method is suitable for batch diffusion and modification of large-size magnets, and achieves good consistency.

The invention belongs to the field of stainless steel. Specifically, the invention relates to soft magnetic stainless steel containing Cr, Cu, Mo, Nb and rare earth elements, and a soft magnetic stainless steel profile and a product prepared from the soft magnetic stainless steel. The Cu element contained in the soft magnetic stainless steel can be separated out to form nano Cu when the soft magnetic stainless steel is subjected to aging treatment, so that the mechanical property of the obtained soft magnetic stainless steel profile can be effectively improved, and the soft magnetic stainless steel profile has excellent low-temperature toughness and soft magnetic property; in addition, microalloy precipitation is optimized through Nb and rare earth element compounding, so that the proper fine grain size is obtained, and the soft magnetic stainless steel profile has excellent low-temperature toughness; and meanwhile, the tensile strength of the soft magnetic stainless steel profile is improved through the solution strengthening effect of Mo, and the corrosion resistance of the soft magnetic stainless steel profile is improved. The soft magnetic stainless steel profile can be effectively applied to electromagnetic valves and related products which serve in low-temperature media and require certain strength, and has good popularization prospects and application value.

Disclosed are a neodymium-iron-boron magnet material, a preparation method, use thereof and a motor. The neodymium-iron-boron magnet material has an amorphous RE-rich phase located in a grain boundary phase. The amorphous RE-rich phase, containing elements TM, RE, Cu and Ga at an atom ratio of TM:RE:Cu:Ga=(15-30):(40-60):(10-25):(10-30), accounts for 3-8% by volume of the grain boundary phase. TM is Fe and Co. RE is a rare earth element. The neodymium-iron-boron magnet material increases the coercivity using none or a small amount of heavy rare earth elements, while maintaining high remanence and magnetic energy.

The invention relates to the technical field of magnetic materials, in particular to high-performance samarium-iron-nitrogen powder and a preparation method and application thereof. The invention provides a preparation method of samarium-iron-nitrogen powder, which comprises the following steps: (1) mixing Sm2O3 powder, Fe powder and a Ca reducing agent, and carrying out reduction reaction to obtain samarium-iron alloy; (2) mixing and crushing the samarium-iron alloy, mixing the crushed samarium-iron alloy with a dispersant and a passivation solution, carrying out ball milling, separating, and drying to obtain samarium-iron alloy powder; (3) nitriding the samarium-iron alloy powder to obtain samarium-iron-nitrogen powder; wherein the dispersing agent is selected from at least one of alkali metal phosphates; the passivation solution comprises chromium chloride, nitric acid, sulfuric acid and colloidal silicon dioxide. The samarium-iron-nitrogen powder prepared through the method has good magnetic performance.

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.

An implantable marker for imaging and surgical guidance by susceptometry comprising one or more pieces of a ferromagnetic material having a total length to diameter ratio of at least about 500, and a total volume of less than about 1×10−11 m3. The one or more pieces of ferromagnetic material may have a high initial relative permeability (μr,i)>about 1000. Also disclosed is a detection system for locating an implantable marker comprising such an implantable marker; at least one drive coil arranged to excite the marker with an alternating magnetic field, and at least one sense coil arranged to detect a signal received from the excited marker; a magnetic field generator arranged to drive an alternating magnetic field through the at least drive coil; and at least one detector arranged to receive the signal from the sense coil and detect one or more harmonics of the drive frequency in the received signal.

The invention discloses a high-performance sintered neodymium-iron-boron magnet and a preparation method thereof.The high-performance sintered neodymium-iron-boron magnet is characterized in that raw materials for preparing the neodymium-iron-boron magnet comprise a main alloy and an auxiliary alloy, and the auxiliary alloy does not contain Fe and Co elements; the microstructure of the neodymium-iron-boron magnet comprises a matrix phase and a rare earth-rich grain boundary phase, the matrix phase is (RE / RE ') 2 (F) 14B, F is Fe and Co, the content of Co is 0-3, the mass percent of Fe to RE / RE' in the rare earth-rich grain boundary phase is 1: (1.4-7), RE is Nd or PrNd, and RE 'is one or more of Pr, Ho, Dy and Tb. The neodymium-iron-boron magnet has relatively high magnet magnetic performance.

The invention discloses a near-net-shape endless rolling non-oriented electrical steel ultra-thin strip and a preparation method thereof, and belongs to the technical field of metal processing. According to the method, the near-net-shape endless rolling non-oriented electrical steel ultra-thin strip with the finished product thickness being only 0.05-0.15 mm is prepared through the processes of smelting, thin slab continuous casting, endless rolling hot continuous rolling, coiling, online heat preservation, acid pickling, primary cold rolling and continuous annealing, normalizing and secondary cold rolling annealing are not needed in the process, and short-process, low-cost and efficient production can be achieved. The defects that the surface of the non-oriented electrical steel ultra-thin strip is corrugated, the magnetic performance is poor, the surface is scratched and severely narrowed in the annealing process, iron loss is not easy to control, and energy consumption is high are overcome, and the prepared non-oriented electrical steel ultra-thin strip is excellent in magnetic property and can be applied to high-frequency and high-speed motors. And the development requirements of new energy and low-altitude economy are met.

The invention relates to a high-flux selective diffusion agent and application thereof. The high-flux selective diffusion agent is obtained by mixing heavy rare earth-containing spherical powder and a solid organic binder and then melting and processing; the particle size of the heavy rare earth-containing spherical powder is 10-60 [mu] m, and the sphericity is greater than 85%. According to the method, the heavy rare earth-containing spherical powder with high sphericity degree and good fluidity and the raw material suitable for additive manufacturing are adopted, and the comprehensive magnetic performance of the subsequently prepared magnet can be remarkably improved by strictly controlling the morphology of the heavy rare earth-containing spherical powder. According to the method, the high-flux selected area dispersion technology is combined with the additive manufacturing means, selected area diffusion is conducted on the surface of the neodymium-iron-boron magnet, and the coercive force and high-temperature stability of the neodymium-iron-boron magnet can be greatly improved under the condition that the use amount of heavy rare earth is small. The method is suitable for multi-batch and small-batch production exploration and has the advantages of being high in technological process automation process and short in research and development period.

The invention provides a method for coating slurry on the surface of a sintered neodymium-iron-boron matrix, a preparation method of a sintered neodymium-iron-boron magnet and the slurry. The method for coating the surface of the sintered neodymium-iron-boron substrate with the slurry comprises the steps that the slurry is prepared; wherein the slurry comprises powder containing heavy rare earth elements, an organic solvent and a binder, and the viscosity of the slurry is 2000-5000 mPa.s; and coating the surface of the sintered neodymium-iron-boron substrate with the slurry by adopting a roller coater to form a coating layer. The slurry provided by the invention is low in viscosity, good in flowability, low in thixotropy, low in shear viscosity mutation rate and low in temperature sensitivity, the weight gain uniformity of magnets in each batch and between batches is good, and the coercive force is obviously improved.

The invention relates to a diffusion source for a neodymium-iron-boron magnet and a preparation method and application of the diffusion source. The invention discloses a rare-earth metal catalyst which comprises the following components in percentage by mass: 46%-49% of an organic solvent, 0.1%-2% of an adhesive, 0.1%-5% of a metal oxide and 46%-49% of rare-earth metal, and the melting point of the metal oxide is higher than that of the neodymium-iron-boron magnet. The specific organic solvent, the adhesive, the metal oxide and the rare earth metal are matched for use according to a specific matching relation, so that the diffusion source is more stable, the diffusion effect is improved, and when the magnet attached with the diffusion source is subjected to thermal diffusion treatment, the rare earth metal can be diffused into the magnet so as to improve the coercive force and other properties of the magnet. In the process, the high-melting-point metal oxide is adhered to the surface of the magnet and then serves as a spacer, the adhesion phenomenon of the magnet in the high-temperature sintering diffusion process is reduced or avoided, grain boundary diffusion is further promoted, and the performance of the magnet is improved.

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.

The invention discloses a neodymium iron boron flexible magnet which is prepared from the following raw materials in parts by weight: 93.5-94.6 wt% of neodymium iron boron magnetic powder; 0.2 wt%-0.5 wt% of a magnetic powder surface treating agent; 2.7 wt% to 3.7 wt% of a binder; 0.3 wt% to 1.0 wt% of an antioxidant; 0.5 wt% to 1.8 wt% of a plasticizer; wherein the binder is prepared by compounding an A-type thermoplastic elastomer and a B-type thermoplastic elastomer; the mass ratio of the A-type thermoplastic elastomer to the B-type thermoplastic elastomer is (1: 9)-(4: 6). The A-type thermoplastic elastomer is selected from one or more of a thermoplastic polyamide elastomer and a thermoplastic polyurethane elastomer; the B-type thermoplastic elastomer is selected from one or more of a styrene block copolymer, a dynamic vulcanization thermoplastic elastomer, a thermoplastic polyolefin elastomer and a thermoplastic polyester elastomer. The granule for the injection molding flexible magnet, which is high in magnetic powder filling ratio and high in flowability, is realized by adopting a mode of double-component magnetic powder and double-component resin, and the high-performance injection molding flexible magnet of which the maximum magnetic energy product (BH) max is 7.5-9.0 MGOe is prepared on the basis of the granule.

The invention discloses a grain boundary diffusion method of a sintered neodymium-iron-boron magnet. The grain boundary diffusion method comprises the following steps: providing a magnet to be diffused; coating the surface of the magnet to be diffused with coating slurry containing heavy rare earth metal powder, and performing grain boundary diffusion after vacuum heat preservation and dehydrogenation; the vacuum heat preservation dehydrogenation process comprises the steps that under the vacuum condition, the temperature is increased to 220-250 DEG C from the normal temperature after 1-1.5 h, heat preservation is conducted for 2-3 h, then the temperature is increased to 520-560 DEG C after 1-2 h, and heat preservation is conducted for 1-2 h; the grain boundary diffusion process comprises the following steps: heating to 650-750 DEG C after 1-1.5 hours, and preserving heat for 24-30 hours for permeation; and finally, the temperature is increased to 970-1000 DEG C after 1-1.5 h, and heat preservation is conducted for 2-3 h. According to the grain boundary diffusion method, the coercive force of the center part of the sintered neodymium-iron-boron magnet with the high permeation thickness can be remarkably improved, and the intrinsic coercive force gradient difference of the surface layer and the center part of the magnet is reduced.