647 results about "Coercivity" patented technology

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.

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.

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.

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 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 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 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.

The invention provides a magnetic code disc film material and a preparation method and application thereof. By introducing the TiN layer, a proper amount of nitrogen atoms can enter lattice gaps of iron, electron cloud distribution of iron atoms is changed, and the magnetic moment of the iron atoms is changed; the magnetic moment of Fe atoms can be influenced by N atoms and crystal structures, an alpha-Fe8N phase is formed in FeCoCr through introduction of N ions, the average magnetic moment of each Fe atom in the alpha-Fe8N phase is 2.4 mu B, alpha-Fe8N is a metastable phase, a sample can finally form stable gamma '-Fe4N through annealing, and the magnetic moment of the stable gamma'-Fe4N is generally about 2.5 mu B-2. 7 mu B and is higher than the magnetic moment 2.2 mu B of the Fe atoms in metal Fe; besides, Ti forms a Ti-Fe weak magnetic phase pinning magnetic domain wall in the FeCoCr thin film, and the coercive force and residual magnetism of the FeCoCr layer can be effectively improved at the same time through the method.

A treatment method for enhancing coercive force of neodymium iron boron magnet includes the following steps: subjecting the neodymium iron boron magnet to electrochemical deposition in a diffusion water-based solution to obtain a neodymium iron boron magnet containing a heavy rare earth; and subjecting the neodymium iron boron magnet containing the heavy rare earth to heat treatment to complete enhancement of the coercive force of the neodymium iron boron magnet. The raw material used in the present invention is cheap heavy rare earth compounds which increases the selection of diffusion sources and lowers costs. Metal alloy particles are mainly obtained in a nanoscale size and can effectively enter crystal grains, and low-melting-point metal alloy components can enhance a demagnetizing coupling effect between main phase grains. According to the present invention, the coercive force of the magnet is increased by nearly 30%, and residual magnetism is almost not changed.

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

The invention provides a linear Halbach array based on a non-uniform permanent magnet and a preparation method of the linear Halbach array, and belongs to the field of permanent magnets. The method comprises the steps that the interior of a mold is divided into an area A1, an area A2 and an area B, wherein the area A1 and the area A2 are symmetrical on the two sides and concave in an arc shape; the B area is loosely filled with low-grade magnetic powder, and the A1 area and the A2 area are loosely filled with high-grade magnetic powder; carrying out compression molding and magnetization orientation to obtain a neodymium iron boron pressed blank; the neodymium-iron-boron pressed blank is subjected to heat treatment after being demolded to obtain the non-uniform permanent magnet, and the heat treatment comprises preheating, gradient sintering of first heating and then cooling, and tempering treatment; and (2n + 3) groups of non-uniform permanent magnets are adhered and fixed by using magnet glue to obtain the linear Halbach array. According to the non-uniform permanent magnet, the non-uniform permanent magnet is manufactured by adopting different marks of magnetic powder partition mold pressing, region strengthening is carried out on the edge, the demagnetization effect of the magnet at the corner angle under the extreme condition is reduced, the local intrinsic coercive force is improved, the service performance of the magnet is enhanced, and the performance of a Halbach array assembled by the non-uniform permanent magnet is promoted to be more excellent.

The invention discloses an energy-saving control method for a new-energy high-low-voltage direct-current relay. The energy-saving control method comprises the steps of analyzing a mapping relation between a silicon steel sheet stacking angle and a magnetic flux path deviation, calculating magnetic domain wall moving resistance according to magnetic domain boundary stress, determining a magnetic domain overturning speed by combining a magnetic field change rate, and measuring a hysteresis loop width parameter. Adjusting the width and frequency of the excitation current pulse according to the magnetic domain overturning frequency and the hysteresis loop offset and width to obtain an optimized excitation current pulse sequence, and determining the hysteresis loop expansion speed according to the hysteresis loop area change rate; the local high-temperature area temperature is analyzed through the iron core temperature rise rate, the local high-temperature area distribution and the magnetic domain energy dissipation data, if the local high-temperature area temperature exceeds the preset threshold value, the excitation current pulse is adjusted, stable iron core temperature rise control data is obtained, the coercive force change amplitude is determined, the magnetic hysteresis loss and the temperature rise are reduced, the stability of the relay under high-frequency switching is improved, and the reliability of the relay is improved. And the operation efficiency and reliability of the system are greatly improved.

The invention discloses a method for preparing (SmxY1-x) Co5 rare earth magnetic particles with high magnetic properties by a chemical method, and belongs to the field of rare earth magnetic materials. The invention particularly relates to a novel technology for preparing (SmxY1-x) Co5 ternary alloy magnetic powder with high magnetic properties by combining chemical liquid phase synthesis with calcium reduction reaction. A Sm (OH) 3 / Y (OH) 3 / Co (OH) 2 (at) Ca (OH) 2 crystalline state mixed precursor prepared by chemical coprecipitation and a hydrothermal reaction is uniformly subjected to a complete calcium reduction reaction with a certain amount of metal calcium particles, KCl and CaCl2 diffusion media in an argon atmosphere, and the magnetic powder is prepared. The saturation magnetization intensity and the residual magnetization intensity of the magnetic powder are improved by doping the yttrium element, but the coercive force of the magnetic powder is slightly reduced, and the method provides a new thought for preparing high-performance rare earth magnetic particles.

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

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

The invention discloses a corrosion-resistant magnetic temperature compensation alloy and a preparation method thereof, and belongs to the field of soft magnetic materials. The alloy is composed of, by atomic percent, 32%-38% of Ni, 0.8%-1% of Co, 1%-2% of Cr, 0.8%-1% of Mn, 0.8%-1.2% of Si, 1%-2% of Al, 0.4%-0.8% of Ti, 0.1%-0.5% of La, 0.1%-0.2% of B and the balance Fe and impurities. Al, Ti, La and B are added in the form of pre-alloyed AlTiLaB alloy powder. The magnetic temperature compensation alloy is prepared through the steps of smelting, refining, adding of AlTiLaB alloy powder, ultrasonic casting and heat treatment. According to the alloy, the corrosion resistance is improved through cooperation of multiple elements, the magnetization intensity is enhanced, the coercive force is reduced, the alloy is suitable for high-power electromagnetic equipment in a complex corrosion environment, and the performance stability and consistency are good.

The invention provides a preparation method of high-performance rapid-quenching samarium-iron-nitrogen magnetic powder, and belongs to the technical field of magnetic materials, and the preparation method comprises the following steps: A1, weighing according to 2-3% excess Sm, and smelting and rapidly hardening samarium powder and iron powder in a small smelting and rapid-quenching device to obtain primary alloy powder; a2, cooling the primary alloy powder, uniformly mixing the cooled primary alloy powder with metal samarium powder, and carrying out smelting and rapid hardening again to obtain secondary alloy magnetic powder; a3, the secondary alloy powder is subjected to HDDR treatment, and modified alloy powder is obtained; and A4, the modified alloy powder is subjected to nitriding treatment, and the high-performance rapid-quenching samarium-iron-nitrogen magnetic powder uniform in structure is obtained. According to the invention, through loss of metal samarium in a primary alloy powder stage and alloy component segregation caused by density difference of a molten pool in smelting, metal samarium complementation in secondary smelting is increased, and the phenomenon of nonuniform magnetic performance of magnetic powder particles caused by alloy component segregation is effectively restrained; and the prepared magnetic material has relatively high coercive force, magnetic performance and uniformity.

The invention discloses a solid flexible neodymium-iron-boron magnet diffusion source and a preparation method and application thereof. The preparation method comprises the following steps: mixing an alloy with a mixed adhesive to prepare diffusion source sol; wherein elements in the alloy comprise rare earth elements and non-rare earth elements; the mixed adhesive comprises a collagen agent, a high-temperature diluent, a low-temperature diluent, a flame retardant and an antioxidant; and carrying out heating drying, cooling and compression molding treatment on the diffusion source sol to prepare the solid flexible neodymium-iron-boron magnet diffusion source. According to the solid-state flexible neodymium-iron-boron magnet diffusion source, diffusion heat treatment is conducted on a commercial sintered neodymium-iron-boron magnet through the diffusion source, the coercive force of the magnet is remarkably improved, and the improvement effect is stable; and meanwhile, the diffusion source has the dual characteristics of solid state and flexibility, can be prepared on a large scale and stably stored, and solves the problems that the neodymium-iron-boron magnet diffusion source is difficult to store and transport.

The invention discloses a neodymium-iron-boron magnet, the neodymium-iron-boron magnet comprises R2T14B main phase grains and a grain boundary phase, a heavy rare earth shell layer is arranged on the surface layer of the R2T14B main phase grains in the area, 0.1-100 microns away from the surface of the magnet, of the neodymium-iron-boron magnet, the neodymium-iron-boron magnet comprises the following components: 28-32 wt% of R, 0.85-0.94 wt% of B, 0.4-2 wt% of Co, 0.1-0.8 wt% of Cu, 0.1-0.3 wt% of Ga, 0.05-0.5 wt% of Al and 0.4-1.0 wt% of M1, M1 is selected from one or two of Ti, Zr, Nb, W and V, and 63-69 wt% of Fe; wherein R is a rare earth element and at least comprises PrNd and RH, and RH is a heavy rare earth element and is selected from one or two of Dy and Tb; wherein the area of all grain boundary phases in the cross section of the neodymium-iron-boron magnet, which is 0.1-100 microns away from the surface of the magnet, accounts for 5.2-7.5% of the total area of the cross section.

The invention relates to a Ti element doped high-performance high-temperature samarium cobalt permanent magnet material and a preparation method thereof, and belongs to the field of rare earth permanent magnet materials. Elements of Sm, Co, Fe, Cu, Zr and Ti with the purity higher than 99.9% are uniformly mixed and smelted into an original cast ingot, a powder metallurgy preparation technology is adopted, the cast ingot is ground into alloy powder, and the samarium-cobalt permanent magnet material is prepared through orientation compression, isostatic pressing, high-temperature sintering, solid solution and isothermal aging heat treatment processes. According to the invention, by doping the Ti element, the grain size is increased, the grain boundary impurity phase precipitation is inhibited, and the thickness and the content of the flaky phase are properly reduced, so that the number of reverse magnetization nucleation sites is reduced, and the magnetic properties such as the coercive force and the maximum magnetic energy product of the magnet are effectively improved.

The invention discloses saturation magnetic induction prediction and component design of an iron-based amorphous alloy and an ultrahigh saturation magnetic induction iron-based amorphous / nanocrystalline alloy. The core effects of ferromagnetic element content, alloy mixing enthalpy and poor electronegativity are disclosed by combining a machine learning model XGBoost with SHAP analysis, the amorphous forming ability is not deteriorated while the high ferromagnetic element content is kept, extremely low coercive force can be obtained after annealing, and collaborative optimization of high saturation magnetic induction, the amorphous forming ability and the coercive force is realized. Parameters used by the component design criterion provided by the invention do not need experimental data, and can be directly calculated from alloy components. High-performance components are rapidly screened in combination with a machine learning model, the research and development period and cost of a traditional trial and error method are remarkably reduced, systematic theoretical guidance is provided for development of high-performance soft magnetic materials, and industrial feasibility is improved.

The invention provides a grain boundary diffusion neodymium iron boron magnet and a preparation method thereof, and relates to the technical field of magnetic materials. The preparation method comprises the steps of surface pretreatment and purification, precise diffusion source construction through magnetron sputtering and diffusion promotion through vacuum heat treatment. The core function of pretreatment is to remove surface impurities and lay a foundation for subsequent deposition of alloy films; the proportion of Tb, Al and Cu in a diffusion source is accurately regulated and controlled in the magnetron sputtering stage, and the synergistic effect is achieved; and the vacuum heat treatment promotes Tb to diffuse into the neodymium iron boron. According to the method, a technical closed loop with pretreatment as a basis, a diffusion source as a core and heat treatment as power is formed, the microstructure of the neodymium-iron-boron magnet is optimized, a complete and continuous shell structure with the moderate thickness is formed, the diffusion depth of heavy rare earth is greatly increased, and the service life of the neodymium-iron-boron magnet is prolonged. Finally, the coercive force of the neodymium-iron-boron magnet is remarkably improved, and the utilization rate of heavy rare earth elements is effectively improved. The problem of low Tb utilization rate in the prior art is solved, and the bottleneck of coercive force improvement is broken through.

A method for preparing a high coercivity grain boundary diffusion neodymium iron boron (NdFeB) magnet by high-pressure torsion, including: Step 1: mixing a NdFeB powder and a heavy rare earth powder, and grinding to achieve uniform mixing to obtain a composite powder; Step 2: pre-pressing the composite powder into a block magnet; Step 3: placing the block magnet in a high-pressure torsion device to cause nucleation, elongation, and refinement to obtain a sheet magnet; and Step 4: performing a diffusion heat treatment on the sheet magnet under a vacuum condition to produce in-situ grain boundary diffusion, and obtaining a high coercivity NdFEB magnet.