5250results about "Magnetic materials" patented technology

The invention belongs to the technical field of soft magnetic materials, and discloses an amorphous nanocrystalline soft magnetic material with high saturation flux density and a preparation method thereof. The preparation method comprises the following steps that an iron-based amorphous strip is crushed into flat powder with the thickness being 5-25 microns and the diameter being 30-80 microns, and scaly amorphous soft magnetic powder is obtained; the method comprises the following steps: performing insulation coating treatment on spherical iron-silicon soft magnetic powder with the average particle size of 2-20 microns to obtain insulation coating modified spherical magnetic powder; and mixing the obtained scaly amorphous soft magnetic powder, the insulating coated modified spherical magnetic powder and bonding resin, performing compression molding, performing annealing crystallization treatment at the temperature of 450-550 DEG C, and then raising the temperature to 600-900 DEG C for sintering treatment to obtain a finished product. According to the amorphous nanocrystalline soft magnetic material and the preparation method thereof, the spherical iron-silicon soft magnetic powder modified through insulation coating is compounded with the scaly amorphous soft magnetic powder, and low loss is maintained while the obtained amorphous nanocrystalline soft magnetic material Bs is remarkably improved.

The invention relates to a neodymium-iron-boron magnet which comprises main-phase crystal grains, a thin-layer crystal boundary phase and a triangular-area crystal boundary phase. Grain boundary phase distribution of a triangular region in the neodymium-iron-boron magnet meets the condition that S1 / S is greater than or equal to 0.057 and less than or equal to 0.073 The neodymium-iron-boron magnet comprises R, M, M1, Co, B and T; r is selected from one or more of Nd, Pr, Ho, Ce, Gd, Dy and Tb; m is selected from one or more of Al, Cu and Ga; m1 is selected from one or more of Ti, Zr, Nb, W and V; t is selected from Fe and other impurity elements; the content of R in the neodymium-iron-boron magnet is 28-32 wt%, and the content of M1 is 0.4-1.0 wt%; the triangular grain boundary phase comprises an R-T-M-Co phase, and the content of Co in the R-T-M-Co phase is 6.2 to 10.4 at%. The neodymium-iron-boron magnet provided by the invention has the advantages that the main phase grain roundness is high, the area proportion of the thin layer grain boundary phase is reduced, the area proportion of the triangular region grain boundary phase is increased, the atomic percent of Co in the R-T-M-Co phase formed in the triangular region grain boundary phase is increased, and the magnet has relatively high coercive force and squareness.

The invention discloses a low-cost high-cerium neodymium iron boron diffusion magnet and a preparation method and application thereof, and relates to the technical field of rare earth permanent magnet materials. Comprising the steps that a neodymium iron boron alloy casting piece Ce30 with the Ce content being 10 wt% and a neodymium iron boron alloy casting piece Ce50 with the Ce content being 15 wt% are prepared through burdening and smelting, after the Ce30 and Ce50 neodymium iron boron alloy casting pieces are evenly mixed, hydrogen decrepitation, jet milling, oriented pressing, cold isostatic pressing and vacuum sintering are sequentially carried out, and a high-cerium sintered neodymium iron boron matrix is obtained; carrying out grain boundary diffusion on the high-cerium sintered neodymium-iron-boron matrix to obtain a high-cerium neodymium-iron-boron diffused magnet; the performance of the blank prepared through the method is close to the N40 mark, the performance of the magnetic sheet after diffusion reaches the 38MT mark, the magnetic performance is kept at the high level, the Ce content is high, efficient utilization of the high-abundance element cerium is achieved, the production cost of the rare earth permanent magnet material is greatly reduced, industrial batch production can be achieved, and balanced utilization of rare earth resources is promoted.

The invention discloses thin-gauge non-oriented silicon steel and a production method thereof, and a motor iron core and a manufacturing method thereof. The production method comprises the following steps: heating a steel billet to 1080-1120 DEG C, preserving heat for 150-200 minutes, performing rough rolling to obtain an intermediate billet of 35-45 mm, performing finish rolling, and coiling to obtain a hot-rolled coiled plate of 2.30-3.00 mm; the initial rolling temperature of finish rolling is 970 + / -20 DEG C, the final rolling temperature is 850 + / -20 DEG C, the reduction rate is 92% or above, and the coiling temperature is 700 + / -20 DEG C; acid pickling and cold rolling are carried out under the condition that normalizing is not carried out, and cold-rolled strip steel with the thickness ranging from 0.15 mm to 0.35 mm is obtained; the total reduction rate of cold rolling is greater than or equal to 86%; performing primary annealing, cooling and coating to obtain a steel plate finished product; the annealing temperature is 830-870 DEG C, and the temperature is kept for 60-90 seconds. Therefore, the same piece of non-oriented silicon steel can meet the requirements of the stator and rotor iron cores at the same time, the manufacturing cost of the stator and rotor iron cores is low, and material waste is avoided.

The invention relates to a neodymium-iron-boron magnet with high residual magnetism and high coercive force, and the neodymium-iron-boron magnet comprises R2T14B main phase grains and a grain boundary phase A, the neodymium-iron-boron magnet comprises R, M, B and Fe, R comprises RL and RH, RL comprises at least one of Pr, Nd, La, Ce and Y, RH comprises at least one of Dy, Tb, Gd and Ho, M comprises Co, Cu and optional M ', and M' comprises one or more of Cr, Ni, Ga, Al, Zr, Nb and Ti; in the grain boundary phase A, the content of R is 29-55 at%, the content of Co is 3-7 at%, and the content of Cu is 7-20 at%. The neodymium-iron-boron magnet provided by the invention is low in impurity element content, the diffusion depth of heavy rare earth elements is effectively improved, and the neodymium-iron-boron magnet has high coercive force and high residual magnetism.

The invention discloses a control method for improving single weight consistency of neodymium-iron-boron green bodies, and relates to the technical field of neodymium-iron-boron magnetic material production, which comprises the following steps: before powder filling, according to the particle size distribution and flow characteristics of superfine neodymium-iron-boron powder, the airflow velocity is preset, so that the airflow is kept stable in the filling process, and the powder can be effectively disturbed; therefore, the filling uniformity is improved. Through real-time monitoring, intelligent analysis and dynamic regulation and control, the single weight consistency of the neodymium iron boron green body is improved, and the problem of flow velocity mutation in the powder filling process is solved. Uniform filling is ensured by presetting the airflow velocity, the powder flowing state is intelligently judged in combination with data collection, feature extraction and a deep learning model, and precise control is achieved. When it is detected that the powder flow speed is abnormally increased, the system adjusts the airflow intensity in a self-adaptive mode and temporarily reduces the feeding amount, and powder accumulation is prevented. The powder filling uniformity is optimized, the green body quality, the magnetic performance stability and the production efficiency are improved, and the rejection rate and material waste are reduced.

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.

The invention discloses a neodymium-iron-boron magnet, which comprises main phase crystal grains, a thin layer crystal boundary phase and a triangular region crystal boundary phase, and is characterized in that the neodymium-iron-boron magnet comprises 28 to 33 weight percent of R, 0.84 to 0.94 weight percent of B, 0.05 to 1 weight percent of Co, 0.05 to 0.55 weight percent of Cu, 0.3 to 0.6 weight percent of Ga, 0 to 0.55 weight percent of M2, 0.1 to 0.6 weight percent of M3, 66 to 70 weight percent of Fe and the balance of Fe, wherein R is a rare earth element and at least comprises PrNd; the triangular region grain boundary phase comprises an R6T13M1 phase, the element M in the R6T13M1 phase is selected from any two or more elements of Al, Cu, Ga, Ti, Sn and / or Zr, and the element T comprises Fe and / or Co; the sum of the areas of the R6T13M1 phases in the microscopic structure cross section of the neodymium-iron-boron magnet accounts for 5.2%-8.4% of the area of the microscopic structure cross section. The rare earth permanent magnet with high residual magnetism, high coercive force and good squareness consistency is obtained under the condition that no heavy rare earth is added or a small amount of heavy rare earth is added.

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.

The invention discloses a neodymium iron boron composite magnet and a production process thereof, and belongs to the technical field of magnetic materials. Carrying out sand blasting and phosphoric acid treatment on the neodymium-iron-boron magnet to obtain a pretreated neodymium-iron-boron magnet; and mixing 50-60 parts of epoxy resin, 30-40 parts of polyurethane and 10-20 parts of polysiloxane, then adding 10-20 parts of a solvent, 8-16 parts of filler, 3-5 parts of an auxiliary agent and 1-3 parts of dibenzoyl peroxide, stirring to obtain a protective coating, then spraying the protective coating on the surface of the pretreated neodymium-iron-boron magnet, and curing to obtain the neodymium-iron-boron composite magnet. The auxiliary agent contains a hindered phenol structure, a benzotriazole structure and fluorine atoms, and a hybrid cross-linked network structure is formed among the auxiliary agent, the epoxy resin and the filler, so that the auxiliary agent and the filler can be highly dispersed and stably exist in the protective coating and fully play roles, and the protective coating has the advantages that the protective coating is more stable in performance due to the combined action of the other raw materials in the protective coating; the neodymium-iron-boron composite magnet has excellent and stable water resistance, aging resistance, corrosion resistance and the like.

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.

The invention discloses an iron-cobalt-based amorphous nanocrystalline soft magnetic alloy and a preparation method thereof, and relates to the technical field of nanocrystalline alloys.The iron-cobalt-based amorphous nanocrystalline soft magnetic alloy comprises an amorphous matrix and nanocrystalline distributed on the amorphous matrix in a dispersed mode, the chemical expression of the iron-cobalt-based amorphous nanocrystalline soft magnetic alloy is FexCoySiaBbPcCdCue, x, y, a, b, c, d and e in the formula respectively represent the atom percentage content of all corresponding components, wherein 6 < = c < = 10, 0 < = e < = 1, and x + y + a + b + c + d + e = 100. The preparation method comprises the following steps: mixing the raw materials according to the atomic percentage, smelting, preparing a molten master alloy ingot into an amorphous alloy strip by adopting a single-roller quenching method, cutting, wrapping with tinfoil, and carrying out annealing heat treatment in an annealing furnace. According to the iron-cobalt-based amorphous nanocrystalline magnetically soft alloy, a wide heat treatment process window can be obtained through component regulation and control, the iron-cobalt-based amorphous nanocrystalline magnetically soft alloy can be suitable for industrial production, and the iron-cobalt-based amorphous nanocrystalline magnetically soft alloy has good soft magnetic performance and can become a new material in the high-frequency working field.

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.

The invention discloses a magnet assembly and a preparation method and application thereof, the magnet assembly at least comprises two magnet units, and two adjacent magnet units have different magnetization directions; a welding point exists between every two adjacent magnet units; each magnet unit can be provided with a plating layer or not on the combination surface of two adjacent magnet units, and the plating layer contains other elements except Nd, Fe and B. The magnet unit is characterized in that the combination surface of the magnet unit and the two adjacent magnet units can be provided with a plating layer or not provided with a plating layer. According to the magnet assembly, on the premise that the Halbach array mode of magnet arrangement is not changed, the connection strength of the magnet structure and / or the stability in severe environments such as high temperature and high humidity are / is remarkably improved, and unnecessary loss of magnet performance is avoided. In addition, the preparation method of the magnet assembly also remarkably improves the assembly efficiency of the magnet assembly, and can be widely applied to large-scale production.

The invention relates to the technical field of magnetic materials, in particular to a grain boundary diffusion method of a neodymium-iron-boron rare earth permanent magnet material, which comprises the following steps: preparing a sintered neodymium-iron-boron diffusion matrix, a diffusion source being turbid liquid slurry consisting of a mixture of rare earth fluoride and rare earth oxide and a proper amount of organic solvent; the method comprises the following steps: processing a diffusion substrate into a required size, carrying out grain boundary diffusion treatment after oil removal and acid pickling treatment, coating the surface of the diffusion substrate with a diffusion source, drying the coated magnet, carrying out primary diffusion treatment, and carrying out secondary low-temperature tempering treatment. The diffusion method provided by the invention is simple in process, can effectively improve the coercive force of the neodymium-iron-boron magnet, especially the coercive force of a Ce-containing magnet, and is embodied in the following aspects: improving the anisotropic field of the surface of a crystal grain, improving the microstructure of a crystal boundary, effectively increasing the diffusion depth, obviously improving the coercive force of the magnet, and improving the coercive force of the neodymium-iron-boron magnet. And the original residual magnetism and the maximum magnetic energy product of the magnet are not obviously reduced.

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.

The invention relates to a high-frequency and high-performance iron-nickel alloy magnetic powder core and a preparation method and application thereof, belongs to the field of metal magnetic powder cores, and solves the problems that in the prior art, when a metal magnetic powder core is applied at high frequency, high magnetic conductivity, high magnetic conductivity stability and high quality factor are difficult to consider, and the saturation flux density is low. And the preparation process is tedious. The invention discloses a preparation method of a high-frequency high-performance iron-nickel alloy magnetic powder core. The preparation method comprises the following steps: S1, preparing raw materials; s2, performing pretreatment; s3, the pretreated iron-nickel alloy powder and nano SiO2 powder are blended, and inorganic insulation coating powder is obtained; s4, adding the inorganic insulating coating powder into a first coating agent to obtain inorganic and first organic insulating coating powder; s5, adding the inorganic and first organic insulation coating powder into a second coating agent to obtain inorganic and double-layer organic insulation coating powder; and S6, compression molding. The comprehensive magnetic performance of the iron-nickel magnetic powder core is improved, and the preparation process is simplified.

A diffusion preparation method of a Fe-rich high-coercivity samarium-cobalt magnet belongs to the technical field of magnetic material preparation, solves the technical problems that the Fe-rich samarium-cobalt magnet is not easy to form a good cellular structure and the process flow is long, and comprises the following steps: S1, weighing a samarium-cobalt permanent magnet alloy raw material, and preparing an alloy ingot; s2, alloy particles are prepared through a mechanical crushing method, and the alloy particles are prepared into alloy powder; s3, the samarium-cobalt alloy powder is subjected to magnetic field orientation forming and cold isostatic pressing forming, and a green body is prepared; s4, performing sintering solution treatment on the green body to prepare a sintered samarium-cobalt permanent magnet blank, and processing the blank into a samarium-cobalt magnet sheet; s5, performing primary PrCu diffusion treatment on the samarium-cobalt magnet sheet; s6, the magnet sheet is subjected to secondary SnFe diffusion treatment; and S7, performing aging treatment on the secondary diffusion sheet to obtain the samarium-cobalt permanent magnet. The preparation method provided by the invention is easy to operate, control and industrialize, and the prepared Fe-rich sintered samarium-cobalt magnet is excellent in performance.

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 invention belongs to the field of rare earth magnetic materials, and particularly relates to a rare earth high-entropy alloy, an annular magnet and a preparation method of the rare earth high-entropy alloy. The invention discloses a rare earth high-entropy alloy, the component of which is (HEA-Re) 2Fe14B, HEA-Re is more than four of rare earth elements La, Ce, Pr, Nd, Y, Gd, Ho, Dy and Tb, and the content proportions of the rare earth elements are the same; meanwhile, the invention discloses a preparation method for preparing the annular magnet by adopting the rare earth high-entropy alloy through the steps of smelting, solution rapid quenching, annealing heat treatment, magnetic powder preparation, magnet pre-forming, hot pressing, thermal deformation and the like, and the prepared annular magnet. According to the annular magnet prepared through the components and the method, the magnetic performance and the mechanical performance are obviously improved, the content of high-price rare earth elements is reduced, and the cost is effectively saved.

The invention discloses a method for preparing anisotropic samarium-iron-nitrogen magnetic powder, and belongs to the technical field of magnetic materials, the method comprises the following steps: preparing Sm and Fe according to design components, and smelting to obtain samarium-iron alloy molten steel; casting the samarium-iron alloy molten steel onto a cooling roller to obtain an iron-samarium alloy sheet; the iron-samarium alloy sheet is placed in a vacuum heat treatment furnace to be subjected to homogenization treatment, the alloy sheet obtained after homogenization treatment is cooled to 200-300 DEG C, in the vacuum environment, hydrogen is introduced into the furnace, the absolute pressure of the hydrogen is controlled to be 0.05-0.1 MPa, and hydrogenation treatment is conducted for 2 h; after hydrogenation is completed, the temperature is increased to 400 DEG C, nitrogen is introduced to 0.5 MPa, the temperature is increased to 530 DEG C, then the furnace temperature is reduced to the room temperature, and the anisotropic samarium-iron-nitrogen magnetic powder is obtained.The preparation method of the samarium-iron-nitrogen magnetic powder has the advantages of being simple in preparation process, low in energy consumption, high in production efficiency, small in magnetic powder particle size, high in magnetic performance and good in magnetocrystalline anisotropy.

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 a neodymium-iron-boron quick-setting casting sheet, neodymium-iron-boron magnetic powder and a preparation method. The neodymium iron boron quick-setting casting piece is provided with a roller attaching surface and a free surface, and the neodymium iron boron quick-setting casting piece is composed of a Re2Fe14B main phase and an intergranular Re-rich phase and does not contain an alpha-Fe phase; the main phase has a columnar crystal morphology along the section in the direction from the roller attaching surface to the free surface, the width of the columnar crystal is 2.5-3.7 microns, dendritic crystals are distributed on the two sides of the columnar crystal, the width of the dendritic crystals is close to the width of the columnar crystal, Re-rich phases are attached to the two sides of the columnar crystal and the two sides of the dendritic crystals, and the Re-rich phases are uniformly distributed along the columnar crystal and the dendritic crystals. The neodymium-iron-boron quick-setting casting piece is beneficial to improving the yield of neodymium-iron-boron magnetic powder and improving the normal distribution of the granularity of the neodymium-iron-boron magnetic powder.