819 results about "Coercivity" patented technology

The invention discloses an efficient and high-precision compensation system and method of an intelligent mutual inductor, and particularly relates to the technical field of mutual inductors. The method comprises the following steps: acquiring magnetic flux density and magnetic field intensity data of a mutual inductor under different current and voltage change rates, generating a hysteresis loop diagram, extracting hysteresis loop width, residual magnetism and coercive force characteristics, and establishing a hysteresis effect error model; the harmonic distortion is identified in combination with spectrum analysis, the harmonic distortion degree in a high-frequency environment is predicted, the hysteresis of the hysteresis effect and the harmonic distortion are comprehensively analyzed, and the accuracy of a compensation algorithm for processing nonlinear errors is evaluated; and finally, the compensation signals are divided into high-accuracy signals and low-accuracy signals, the high-accuracy signals are directly output, and the low-accuracy signals are output after error correction, so that the problem that a conventional compensation algorithm cannot correct non-linear errors is effectively solved, and the measurement precision of the mutual inductor in an extreme environment and the operation stability of a system are 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 method for synchronously reducing hysteresis loss and eddy-current loss of a FeSiAl magnetic powder core, which comprises the following steps: preparing a salt solution of metal M which is low-melting-point metal with atomic radius unequal to that of Al atoms and can form a replacement solid solution with Al; adding the salt solution into the FeSiAl magnetic powder core, drying to obtain an insulated and coated magnetic powder core, and then adding a binder and a lubricant to prepare magnetic powder to be formed; and performing compression molding on the to-be-molded magnetic powder, and performing heat treatment to obtain the magnetic powder core. The low-melting-point M atoms are diffused into the FeSiAl matrix and occupy Al vacancies, lattice distortion can be reduced in the annealing process, and therefore coercive force and magnetic hysteresis loss are reduced; more importantly, after the FeSiAl is doped with the M atoms, the resistivity of the matrix is increased, eddy-current loss in the particles can be effectively inhibited, meanwhile, the Al2O3 coating layer generated through in-situ oxidation can effectively isolate the eddy-current loss among the particles, and therefore the magnetic hysteresis loss and the eddy-current loss are synchronously reduced through the method.

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 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.

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 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.

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.

The invention discloses a neodymium-iron-boron magnet and a preparation method and application thereof. The neodymium-iron-boron magnet comprises an easy-to-demagnetize area, a non-easy-to-demagnetize area and a bonding area, and the volume of the easy-to-demagnetize area accounts for 15%-50% of the total volume of the neodymium-iron-boron magnet; wherein the volume of the bonding area accounts for 0.5%-4.0% of the total volume of the neodymium-iron-boron magnet; wherein the ratio of the coercive force of the non-easy demagnetization area to the coercive force of the easy demagnetization area is 0.7-1. According to the neodymium-iron-boron magnet provided by the invention, the cost can be greatly reduced, and meanwhile, good demagnetization resistance is kept.

The invention discloses a C-band ultralow-loss self-bias hexagonal gyromagnetic ferrite material, and belongs to the technical field of ferrite material preparation. The ferrite material comprises a BiCaZrVIn-YIG gyromagnetic ferrite material and a LaScBiCu-BaM hexagonal gyromagnetic ferrite material, wherein the weight ratio of the BiCaZrVIn-YIG gyromagnetic ferrite material to the LaScBiCu-BaM hexagonal gyromagnetic ferrite material is 0.1 to 10; the doping agent accounts for the weight percentage of the ferrite material, and the doping agent comprises the following components in percentage by weight: 0.3-0.7 wt% of La2O3, 0.4-0.8 wt% of SiO2 and 0.5-0.9 wt% of SrTiO3. According to the invention, LaScBiCu-BaM hexagonal gyromagnetic ferrite with high Mr / Ms and Hc characteristics is grown on the surfaces of low-loss BiCaZrVIn-YIG gyromagnetic ferrite particles, and a hexagonal gyromagnetic ferrite material with high and adjustable anisotropic field Ha, high coercive force Hc and residual magnetism ratio Mr / Ms, ultralow ferromagnetic resonance line width H and dielectric loss tan delta epsilon characteristics is developed. And the engineering requirements of low loss and wide bandwidth of the C-band miniature integrated device are met.

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 belongs to the technical field of magnetic functional materials, and particularly relates to a nanocrystalline magnetically soft alloy and a preparation method and application thereof. The invention provides a nanocrystalline soft magnetic alloy which comprises the following chemical components: Fe, Si, B, Nb, Cu, P and rare earth metal, and the rare earth metal is selected from at least one of Nd and Sm. According to the nanocrystalline magnetically soft alloy, a proper amount of rare earth metal is added, the ferromagnetic coupling exchange effect between ordered phases of the nanocrystalline magnetically soft alloy is improved, so that the magnetic induction intensity and the high-frequency magnetic conductivity of the nanocrystalline magnetically soft alloy are both improved, the magnetic conductivity of the nanocrystalline magnetically soft alloy at 100 kHz can reach 42000 or above, and the high-frequency magnetic conductivity of the nanocrystalline magnetically soft alloy at 100 kHz can reach 42000 or above. Meanwhile, the saturation flux density reaches up to 1.75 T or above, and the coercive force is as low as 0.8 A / m.

The invention relates to the technical field of neodymium-iron-boron magnets, in particular to a neodymium-iron-boron rare earth magnet and a preparation method thereof.The neodymium-iron-boron rare earth magnet is a sintered neodymium-iron-boron permanent magnet and comprises a main phase, a two-particle grain boundary phase and a triangular area grain boundary phase; the main phase comprises an R2T14B phase, R refers to at least one of Nd and Pr, T refers to Fe, and Co at least contains Fe; the two-particle grain boundary phase comprises a grain boundary copper-rich phase, and / or a needle-shaped ZrBx phase with the width of 10-50 nm, and / or a needle-shaped TiBx phase with the width of 10-50 nm; the triangular region grain boundary phase comprises an FCC type NdOx phase, an RCu phase, an RGa phase, an R-rich phase, a 6: 14 phase and / or a needle-shaped ZrBx phase with the width of 10-50 nm and / or a needle-shaped TiBx phase with the width of 10-50 nm, the neodymium-iron-boron rare earth magnet does not contain heavy rare earth and is good in uniformity, and the coercive force and residual magnetism can be regulated and controlled through the design of the grain boundary phase.

A preparation and diffusion treatment method for a high-performance diffusion coating used for a sintered neodymium-iron-boron magnet. The method comprises the following steps: the preparation of alloy powders, the preparation of glue, the preparation of a diffusion coating, a pretreatment, coating with the coating, surface drying, and a heat treatment. By controlling the components and particle size of the alloy powders, the compounding of the glue, an anti-bonding powder and an auxiliary agent ensures that under the condition of a relatively small usage amount of a diffusion heavy rare earth metal, the coercive force is greatly improved, the residual magnetism is almost not reduced or is slightly reduced, and the phenomena of the shedding of the coating and the bonding of magnetic sheets after diffusion are avoided.

The invention belongs to the technical field of iron-based material preparation, and particularly relates to a method for optimizing soft magnetic performance of an iron-based amorphous alloy through cyclic stress annealing, the iron-based amorphous alloy and application. The method comprises the steps that periodic stress is applied to the iron-based amorphous alloy, and periodic strain is generated; the peak strain of the periodic strain is less than or equal to 2%, and the valley strain of the periodic strain is lower than the peak strain. Appropriate periodic stress is applied to the iron-based amorphous alloy at the low temperature, periodic strain is generated, the negative influence of rapid cooling on the soft magnetic performance during preparation of the iron-based amorphous alloy in the prior art can be improved, the brittleness problem generated by high-temperature annealing can be avoided, the soft magnetic performance and brittleness are better balanced, and the service life of the iron-based amorphous alloy is prolonged. And the effect of coexistence of ultralow coercive force and good toughness is achieved.

The invention belongs to the technical field of magnetic materials and sensing, and particularly discloses a magnetic code disc material, an angular displacement magnetic sensor, a high-speed motorized spindle of a numerical control machine tool and a preparation method.The magnetic code disc material comprises a metal substrate, a Ta buffer layer, a FeCoCr-clamped TaN low-dimensional magnetic film and a Ta protective layer, the invention also discloses an angular displacement magnetic sensor made of the magnetic code disc material, the angular displacement magnetic sensor has 512 phase-AB magnetizing magnetic poles, and the distance between the phase-AB magnetizing magnetic poles is 0.4 mm; and one Z-phase magnetizing magnetic pole is arranged, the width is 0.4 mm, and the Z phase is not diffused. The magnetic code disc material disclosed by the invention has more excellent magnetic domain size, excellent coercive force and residual magnetism performance, so that more excellent magnetic pole density can be provided when the magnetic code disc material is applied to an angular displacement magnetic sensor, the signal density is higher, and the magnetic code disc material can be applied to the angular displacement magnetic sensor through the AB-phase and Z-phase matching structure of the magnetic sensor. Therefore, when the angular displacement magnetic sensor is applied to a high-speed motorized spindle of a numerical control machine tool, the precision of the numerical control machine tool can be improved.

The invention provides a method for strengthening the coercive force of a neodymium-iron-boron magnet through composite reduction grain boundary diffusion, which comprises the following steps of: (1) mixing a reducing agent, a dispersing agent and a composite rare earth diffusion source to obtain mixed powder; the composite rare earth diffusion source comprises a multi-element rare earth compound diffusion source and / or a composite compound diffusion source; (2) coating the mixed powder obtained in the step (1) on the surface of a neodymium-iron-boron magnet to obtain a coating layer magnet; and (3) carrying out sectional composite reduction-grain boundary diffusion heat treatment and tempering treatment on the coated magnet in the step (2) to obtain the neodymium iron boron diffusion magnet. According to the method, the composite rare earth diffusion source is adopted, the preparation cost of the neodymium iron boron diffusion magnet is reduced, meanwhile, the grain boundary diffusion efficiency is improved, and the large-scale market application prospect is achieved.

The invention provides a method for preparing a high-coercivity sintered neodymium-iron-boron magnet, and belongs to the technical field of rare earth permanent magnet material preparation, and the method comprises the following steps: 1, taking the sintered neodymium-iron-boron magnet as a base material, and removing an oxide layer through alkali washing deoiling, ultrasonic water washing and acid pickling cleaning; 2, taking the Pr-Dy-Cu-Ga quaternary alloy as a diffusion source, and cutting the Pr-Dy-Cu-Ga quaternary alloy into slices; 3, attaching the thin sheet to the surface of a base material for diffusion heat treatment; fourthly, low-temperature tempering is conducted; 5, testing a room temperature demagnetization curve of the sample; light rare earth Pr replaces a part of heavy rare earth Dy and is matched with Cu and Ga elements in a certain proportion to be smelted to obtain quaternary alloy, the quaternary alloy with low heavy rare earth serves as a diffusion source, the microscopic characteristics of the magnet are improved, grain boundary phase distribution is optimized, and under the condition that residual magnetism and the maximum magnetic energy product are slightly reduced, the coercive force of the sintered neodymium-iron-boron magnet is improved; and terbium and dysprosium are not used, so that the use amount of heavy rare earth elements and the production cost are reduced.

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 the technical field of heat treatment of neodymium-iron-boron permanent magnet materials, in particular to a uniform heat treatment process of a neodymium-iron-boron permanent magnet material. The invention discloses a uniform heat treatment process for a neodymium iron boron permanent magnet material. The uniform heat treatment process comprises the following steps: preparing fluorinated carbon nanotubes; preparing permanent magnet powder containing the fluorinated carbon nanotubes; ultrasonic preheating of the permanent magnet powder; and performing uniform heat treatment on the permanent magnet. In the tempering heat treatment process of the sintered magnetic block, the tempering furnace is filled with the plasmas with good heat conductivity, the magnetic field generated by the magnetic block is offset through the magnetic field generation device, the influence of the magnetic field on distribution of the plasmas is prevented, and therefore the plasmas are evenly distributed in the tempering furnace; and when part of the heating burners are started to carry out low-temperature tempering treatment on the magnetic block, heat can be uniformly distributed in the tempering furnace through plasmas, so that the magnetic block is uniformly heated, and the coercivity of the neodymium iron boron permanent magnet material is better improved.

The invention discloses an iron-based nanocrystalline soft magnetic alloy and a preparation method thereof. A magnetically soft alloy strip is prepared through smelting and a single-roller melt-spinning method, stress relief annealing is carried out on the magnetically soft alloy strip through assistance of a magnetic field, and then crystallization annealing treatment is carried out. Different from a traditional method for regulating and controlling the magnetic performance of the alloy through precipitation of a large number of nanocrystals, the method only induces precipitation of a very small number of nanocrystals, and high saturation flux density and low coercive force can be obtained while the toughness of the strip is ensured; the iron-based nanocrystalline soft magnetic alloy with high saturation flux density and low coercive force can be prepared by taking Fe as a main element, Co element with the atomic fraction lower than 8%, Cu element with the atomic fraction lower than 1% and at least one of oxygen, sulfur, phosphorus, carbon, silicon, boron and the like as other trace elements.

The invention relates to the field of metal soft magnetic materials, in particular to a high-frequency high-permeability metal soft magnetic powder core and a preparation method thereof. The preparation method comprises the following steps: S1, screening magnetically soft alloy powder with a preset particle size; s2, preparing passivation powder; s3, preparing granulation powder; s4, a blank is prepared through compression molding; s5, the blank piece is subjected to curing treatment; and S6, the cured part is subjected to high-temperature heat treatment in vacuum, and the high-frequency and high-permeability metal soft magnetic powder core is obtained. The preparation method disclosed by the invention is simple, mild in reaction condition, low in cost and capable of realizing automatic large-scale production. The high-frequency and high-permeability metal soft magnetic powder core prepared by the invention has high frequency, high magnetic induction intensity and high unit power density, particularly, the internal stress of a metal soft magnetic material is released to the greatest extent by adopting high-temperature heat treatment, the coercive force is reduced, the density and the permeability are remarkably improved, and the high-frequency and high-permeability metal soft magnetic powder core is widely applied to DC-DC and power supply circuits with ultrahigh switching frequency and high magnetic conductivity. And a MHz-level power supply circuit.

The invention belongs to the technical field of magnetic material preparation, and particularly relates to permanent magnetic ferrite and a preparation method and application thereof. The preparation method of the permanent magnetic ferrite provided by the invention comprises the following steps: (1) mixing iron scale subjected to heat treatment with strontium carbonate, and carrying out dry vibration ball milling and pre-sintering to obtain pre-sintered powder; wherein the temperature of the heat treatment is 700 to 900 DEG C; and (2) mixing the pre-sintered powder with a first additive, and sintering. The residual magnetism (Br), the magnetic induction coercive force (Hcb), the intrinsic coercive force (Hcj) and the maximum magnetic energy product ((BH) max) of the prepared permanent magnetic ferrite are relatively high.

The invention belongs to the technical field of neodymium iron boron rare earth permanent magnets, and relates to a cerium-containing neodymium iron boron magnet with high coercivity and high stability and a preparation method thereof. According to the preparation method, the cerium-containing copper auxiliary alloy and the neodymium iron boron magnetic powder are ingeniously combined, the whole preparation process is optimized, and remarkable technical progress and economic benefits are achieved. Firstly, in the aspect of magnetic performance, Ce in a specific proportion is added into the cerium-containing copper auxiliary alloy, the cerium-containing copper auxiliary alloy is used, the coercive force of a magnet is effectively improved, high residual magnetism is kept to a certain degree, and introduction of Cu is beneficial to refining of grains and improvement of a grain boundary phase structure; therefore, the reverse magnetization resistance in the magnet is enhanced, and the magnet can maintain stable performance in a wider temperature range.

The invention belongs to the technical field of particle accelerators, and discloses a nonlinear impact magnet based on a nanocrystalline magnetic material and a matched power supply system. The nonlinear impact magnet comprises a magnetic core and a magnet exciting coil assembly, the magnetic core comprises magnetic poles and a magnetic yoke; the magnetic pole and the magnet yoke are both of a fully-symmetrical annular structure, and the magnet yoke is arranged on the periphery of the magnetic pole. The magnetic pole comprises N same magnetic pole units, N is 4, 6 or 8, and the magnetic pole is made by laminating nanocrystalline strips; and the excitation coil assembly is wound outside each magnetic pole unit. Compared with a traditional silicon steel sheet or ferrite magnetic core, the magnet provided by the invention can improve the uniformity of a magnetic field, and the magnetic pole made of the nanocrystalline strip with ultrahigh magnetic conductivity and low coercive force has stronger magnetic field uniformity and low disturbance characteristic; and the design requirement of the STCF clash ring off-axis injection system for low disturbance of the circulating beam bunch can be better met.

The present invention relates to the technical field of powder metallurgy, and in particular to a sintered NdFeB and a preparation method thereof, wherein the heat treatment temperature and time are adjusted to promote the RE6Fe 13 The M phase is generated or disappears, thereby increasing or decreasing the remanence and coercivity of the magnet; specifically, by composition design or adding RE6Fe to the grain boundary 13 The M phase alloy composition is then adjusted to 420‑700°C heat treatment temperature to promote RE6Fe 13 The M phase is formed or disappears. This method can regulate the changes in remanence and coercivity within a certain range to improve the redundancy of the formulation process, and at the same time can better adapt to the different performance requirements of customers, with excellent economic benefits.

The invention relates to the technical field of neodymium-iron-boron magnets, in particular to a Zr-containing neodymium-iron-boron magnet and a preparation method and application thereof.The Zr-containing neodymium-iron-boron magnet comprises main phase crystal grains and a grain boundary phase, and the component of the main phase crystal grains is R2Fe14B; zrC particles are distributed in the grain boundary phase; the grain boundary phase comprises two thin-layer grain boundary phases and a triangular grain boundary phase, the two thin-layer grain boundary phases are located between any two main phase grains, and the triangular grain boundary phase is located between any three or more main phase grains; a strong carbide is added into the magnet to form an element Zr, in the sintering process, Zr reacts with C dissolved in an Nd-rich phase, and a large number of ZrC particles exist in a triangular grain boundary phase, so that the content of C dissolved in the Nd-rich phase is reduced, the coercivity of the magnet is improved, meanwhile, a small number of ZrC particles are generated in a two-grain thin-layer grain boundary phase, growth of main-phase grains can be hindered, and the coercivity of the magnet is improved. And the coercive force of the magnetic force is further improved.

The invention discloses auxiliary alloy nano powder, modified magnetic powder, a sintered neodymium-iron-boron magnet and a preparation method. According to the preparation method of the auxiliary alloy nanopowder for modifying the magnetic powder, the chemical component of the auxiliary alloy nanopowder is Re100-m-n (Cu, X) mQn, Re is a light rare earth element, X is selected from at least one of Al, Ga, Co, Mg, Sn, Te and Sb, and Q is selected from at least one of Ti, Zr, Hf, V, Nb, Ta, W and Mo; m and n are atomic numbers respectively, m is greater than or equal to 24 and less than or equal to 72.4, n is greater than or equal to 12.5 and less than or equal to 76, and 100-m-n is greater than or equal to 0; the auxiliary alloy nano powder does not contain Fe and B; the preparation method comprises the following steps: (1) providing an auxiliary alloy sheet; and (2) mixing the auxiliary alloy sheet, a modified substance and an organic solvent, and carrying out primary crushing and fine crushing to obtain the auxiliary alloy nano powder. The coercive force and the squareness of the sintered neodymium-iron-boron magnet can be improved, and the absolute value of the residual magnetism temperature coefficient and the absolute value of the coercive force temperature coefficient of the sintered neodymium-iron-boron magnet are reduced.

The invention provides a high-performance neodymium-iron-boron magnet formed by MIM (metal injection molding), which comprises the following components in percentage by weight: 28 to 38 weight percent of Re, 4 to 5 weight percent of FeB, 0.05 to 0.2 weight percent of Cu, 0 to 0.15 weight percent of Al, 0.15 to 0.3 weight percent of Ga, 0.2 to 1.5 weight percent of Co, 0.15 to 0.2 weight percent of Zr and the balance of iron and other inevitable impurities, the MIM injection molding process is carried out under the protection of nitrogen, the position of an extrusion material rod opening and the interior of a mold cavity are both under the protection of inert gas, and the extrusion material rod opening and the mold cavity are sealed. Meanwhile, a mold core is in a pulsed magnetic field environment in the injection molding process, it is guaranteed that the magnet has a proper neodymium-rich phase by regulating the rare earth content to be 28-38%, and therefore the coercive force of the magnet is improved, the compactness of the magnet is improved, the production cost is reduced, and through the optimized jet milling technology, the particle size and particle size distribution of neodymium-iron-boron powder are controlled, so that the yield of neodymium-iron-boron powder is improved. And meanwhile, the proportions of the magnetic powder with different particle sizes are adjusted through the sorting wheel, so that gap coating of the pre-coating solute is facilitated, and the injection molding density of the MIM neodymium iron boron is improved.

The present invention provides a flywheel energy storage flux adjustable induction motor and its magnetic adjustment method, wherein the motor comprises two permanent magnets with different coercive forces and a DC magnetic adjustment winding. A square wave pulse is input into the DC magnetic adjustment winding to generate a magnetic adjustment magnetic field, so that the residual magnetism of the low-coercive force permanent magnet changes in magnitude or direction, thereby realizing rapid adjustment of the motor air gap flux. When the motor is working, the DC magnetic adjustment winding is disconnected, and the residual magnetic flux generated by the high-coercive force permanent magnet and the low-coercive force permanent magnet enters the air gap in parallel to provide excitation flux for the motor; when the motor is on standby, a negative square wave pulse is input into the DC magnetic adjustment winding to generate a magnetic adjustment magnetic field that can reversely saturate magnetize the low-coercive force permanent magnet, so that the low-coercive force permanent magnet is reversely magnetized, and the residual magnetic flux of the high-coercive force and low-coercive force permanent magnets is equal in magnitude and opposite in direction, so that the air gap flux is reduced to 0, thereby eliminating standby iron loss. In addition, the DC magnetic adjustment winding can also be used as a backup excitation source to prevent the risk of permanent magnet demagnetization.