152results about How to "Improve coercive force" patented technology

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 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.

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 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 relates to the technical field of sintered neodymium-iron-boron magnet preparation technologies, in particular to a sintered neodymium-iron-boron pressure-assisted grain boundary diffusion enhancing method and a sintered neodymium-iron-boron magnet, and the sintered neodymium-iron-boron pressure-assisted grain boundary diffusion enhancing method comprises the following steps: S1, after a neodymium-iron-boron magnet is sintered, low-temperature pre-aging cooling is performed to normal temperature; s2, performing slicing, diffusion pretreatment, rare earth diffusion source coating, non-rare earth diffusion source pressure compounding and diffusion heat treatment on the pre-aged magnet; the composition of a sintered neodymium-iron-boron magnet matrix is RE < x > M < y > B < z > Fe < 100-x-y-z >, wherein RE comprises at least two elements of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; the strength and toughness of the magnetic steel are improved, the unfilled corner rate is reduced, meanwhile, the grain boundary phase width is increased through pre-aging, a channel is provided for diffusion, the diffusion effect is improved, and the temperature coefficient of a product is improved, so that a diffusion source, especially a spraying or printing diffusion source, is better combined with a substrate.

The invention provides a neodymium iron boron sintered magnet and a preparation method and application thereof. The neodymium iron boron sintered magnet comprises the following components: R, wherein the mass content of R is 28-33wt%; r comprises Nd and Ce, and optionally comprises or does not comprise at least one of Pr, Dy, Tb, Ho and Gd; m, wherein the mass content of the M is 1.5-2.5 wt%; b, the mass content of the B is 0.95 to 1.05 wt%; the mass content of the Ti ranges from 0.1 wt% to 0.25 wt%; fe is the balance; in the neodymium iron boron sintered magnet, the mass content of Ce is 0.3-5 wt%. By accurately controlling the main alloy element components, the generation of a soft magnetic phase in main phase grains is avoided; and meanwhile, the element components of the auxiliary alloy are optimized, and the dosage ratio of the main alloy to the auxiliary alloy is adjusted, so that main phase grains are refined, a fine titanium-rich phase which is dispersed and distributed is formed in a grain boundary phase, and the magnetic performance of the product is improved.

The invention provides a method for improving coercive force of a neodymium-iron-boron magnet through power ultrasonic treatment, and belongs to the field of magnets. According to the method for improving the coercive force of the neodymium-iron-boron magnet through power ultrasonic treatment, in the heat preservation process of heat treatment of the neodymium-iron-boron sintered magnet, contact type introduction power ultrasonic treatment is carried out; the method for improving the coercive force of the neodymium-iron-boron magnet through power ultrasonic treatment comprises the steps that a neodymium-iron-boron sintered magnet is sequentially subjected to first heat treatment, second heat treatment and third heat treatment, and the high-coercive-force neodymium-iron-boron magnet is obtained; in the heat preservation process of at least one time of heat treatment in the first heat treatment, the second heat treatment and the third heat treatment, contact type introduction power ultrasonic treatment is carried out. According to the method for improving the coercive force of the neodymium-iron-boron magnet through power ultrasonic treatment, the volume ratio of a rare earth-rich phase (alpha (RE)) in a grain boundary structure of the neodymium-iron-boron magnet can be obviously increased, and the coercive force of the neodymium-iron-boron magnet can be further improved.

The invention discloses a large-size high-performance R-T-B rare earth permanent magnet and a preparation method thereof. The thickness of the magnet in the orientation direction is 4-14 mm; the residual magnetism Br of the large-size high-performance magnet is greater than or equal to 14.0 kGs, and the coercive force Hcj is greater than or equal to 23.0 kOe. When the magnet base body is prepared, a layered powder laying mode is adopted, so that the surface layer of the magnet is made of single alloy easy to diffuse, the core part of the magnet is made of double alloy, it is guaranteed that the core part of the magnet has high coercive force, meanwhile, the grain boundary diffusion capacity of the surface layer of the magnet is optimized, and the advantages of the double alloy and grain boundary diffusion are fully combined. Besides, an alloy of a low-melting-point metal element M2 and a heavy rare earth element RH in a certain proportion is adopted as an auxiliary alloy and a grain boundary diffusion source, the diffusion depth of the heavy rare earth element RH is promoted, excessive enrichment of the heavy rare earth element RH in a small area is prevented, and generation of body diffusion is inhibited. According to the method, the coercive force of the magnet is remarkably improved, meanwhile, it is guaranteed that the magnet has high residual magnetism, and the large-size high-performance R-T-B rare earth permanent magnet is prepared.

The invention discloses a thermal deformation neodymium-iron-boron magnet and a preparation method thereof, the component of the thermal deformation neodymium-iron-boron magnet is RaCobBcNidCueTfFebal, R is one or more rare earth elements taking Nd as an essential element, T is selected from one or two of Ti and Zr, a + b + c + d + e + f + bal = 100 (by atomic percent), 13.5 < = a < = 16.5, 0.0 < = b < = 2.0, 5.2 < = c < = 5.6, 0.2 < = d + e < = 3.0, and 0 < = f < = 0.2. In the magnet, non-ferromagnetic grain boundary phases exist on the grain boundaries of the c surface and the ab surface of neodymium iron boron grains.

The invention provides a method for remarkably improving the coercive force of a cerium-rich neodymium-iron-boron magnet. The method comprises the following steps: (1) preparing cerium-rich magnetic powder I of which the cerium content accounts for not less than 24% of the total content of rare earth; (2) preparing cerium-poor rare earth-rich magnetic powder II in which the cerium content is not more than 24% of the total content of rare earth and the total content of the rare earth is more than 30%; (3) preparing low-melting-point nano metal powder III by taking at least one of Ga, Al, Zn and Sn as a raw material; (4) magnetic powder I, magnetic powder II and metal powder III with the mass being m1, m2 and m3 are taken and mixed uniformly according to the ratio that (m2 + m3): m1 is larger than or equal to 1 and larger than 0, and after uniform mixing, orientation forming, sintering and cutting machining are conducted to prepare a base material; and (5) the surface of the base material is coated with the diffusion source, the weight of the base material is increased by md, 0.05 > = md: (m1 + m2 + m3) > 0, then heat treatment is conducted, and the cerium-rich neodymium-iron-boron magnet is obtained. The prepared cerium-rich neodymium-iron-boron magnet has the advantages of being excellent in performance, low in cost, high in cost performance and the like, and especially compared with a conventional cerium-rich neodymium-iron-boron magnet, the coercive force of the cerium-rich neodymium-iron-boron magnet is greatly improved.

The present invention relates to the field of magnetic material technology, and in particular to a method for preparing isotropic samarium iron nitrogen magnetic powder and isotropic samarium iron nitrogen magnetic powder. A method for preparing isotropic samarium iron nitrogen magnetic powder comprises the following steps: 2 Fe 17 The invention discloses a method for preparing a samarium iron alloy by mixing metal Sm and Fe with an excess of 5% to 10% of Sm, and then melting and rapidly solidifying the metal Sm-Fe alloy flakes; crushing the Sm-Fe alloy flakes to prepare powdered Sm-Fe alloy; subjecting the powdered Sm-Fe alloy to HDDR treatment to obtain an isotropic alloy block; crushing the isotropic alloy block, and subjecting the powdered Sm-Fe alloy to aging treatment to obtain an isotropic alloy powder; subjecting the isotropic alloy powder after aging treatment to high temperature nitriding treatment to obtain Sm 2 Fe 17 N 3 Isotropic magnetic powder. The prepared isotropic samarium iron nitrogen magnetic powder has both high magnetic energy product and coercive force.

The invention provides a grain boundary diffusion neodymium-iron-boron magnet base material and a preparation method of a grain boundary diffusion neodymium-iron-boron magnet, and relates to the technical field of sintered neodymium-iron-boron materials. The grain boundary diffusion neodymium-iron-boron magnet base material comprises, by mass, 29.2% < = Nd < = 29.6%, 0.96% < = B < = 0.98%, < = 0.2% of Cu + Ga, < = 0.15% of Zr, < = 1% of Co, 0 < = Ti < = 0.06% and the balance iron and inevitable impurities. According to the method, the defects in the prior art are overcome, the problem that high-remanence neodymium iron boron lacks grain boundaries and cannot be effectively diffused can be solved by controlling the element ratio and finely regulating and controlling in the preparation process, the coercive force of the base material is greatly increased, and only a small amount of remanence is lost.

The invention discloses a diffusion source, a preparation method of the diffusion source and a processing method of a neodymium-iron-boron magnet. The diffusion source comprises aluminum or aluminum alloy foil, wherein rare earth element-containing particles, non-rare earth metal oxide and non-rare earth metal are attached to the upper surface and the lower surface of the aluminum or aluminum alloy foil respectively; the rare earth elements in the rare earth element-containing particles are selected from one or more of terbium, dysprosium, praseodymium and neodymium; the rare earth element-containing particles are selected from one or more of rare earth hydride particles, rare earth fluoride particles and rare earth metal particles; the non-rare earth metal oxide is selected from one or more of aluminum oxide and magnesium oxide; the non-rare earth elements in the non-rare earth metals are selected from one or more of copper, aluminum, magnesium, iron, zirconium, niobium and gallium. The diffusion source can reduce the use amount of rare earth elements and effectively improve the coercive force of the neodymium-iron-boron magnet.

The invention discloses a method for preparing a neodymium iron boron permanent magnet through composite diffusion, and relates to the technical field of rare earth permanent magnet material processing. The method comprises the following steps: step 1, weighing a main alloy material and an auxiliary alloy material; secondly, the main alloy material is smelted and cast into a throwing piece through a piece casting furnace, and then the throwing piece is subjected to annealing treatment. According to the invention, through a composite grain boundary diffusion technology, evaporation treatment is firstly carried out to obtain an intermediate-state magnet, so that the demagnetization exchange coupling effect between adjacent main phase grains is enhanced, and a channel beneficial to subsequent diffusion of heavy rare earth elements is also formed; and then complete diffusion between grain boundaries is achieved, the maximum diffusion depth is achieved, and the best diffusion effect is achieved through subsequent aging treatment.

The present application relates to the field of magnet technology, and specifically discloses a high coercive force NdFeB magnetic material and a preparation method thereof. The high coercive force NdFeB magnetic material of the present application includes a magnetic material body, a heavy rare earth layer and a light rare earth layer. The magnetic material body is mainly made of the following raw materials: neodymium, gadolinium, copper, boron, cerium, aluminum, niobium iron, and iron; the preparation method includes: the preparation of the magnetic material body includes the following steps: melt stripping, hydrogen crushing and grinding, pressing and molding, and sintering to obtain a magnetic material body one; the preparation of the heavy rare earth layer includes the following steps: slicing, mixing, heating and melting, evaporation, and forming a thin film on one side of the slice; infiltration, quenching and tempering treatment to obtain a magnetic material body two; the preparation of the light rare earth layer includes the following steps: preparing a light rare earth alloy sheet, the light rare earth alloy sheet is attached to the side of the magnetic material body two opposite to the heavy rare earth layer, and thermal diffusion and tempering are performed to obtain the magnetic material body two. The NdFeB magnetic material of the present application has high coercive force and low cost.

The permanent magnet comprises, by mass, REaNbFe100-a-b-c-dCocBd, RE is a combination of two or more of rare earth elements including lanthanum, cerium, praseodymium and neodymium and must contain the cerium element, the mass percentage of the cerium element is not lower than 6%, N is one or more of aluminum, copper, gallium and zirconium, the sum of the mass percentage of the elements is not lower than 6%, the sum of the mass percentage of the elements is not lower than 6%, the sum of the mass percentage of the elements is not lower than 6%, and the sum of the mass percentage of the elements is not lower than 6%. The permanent magnet is prepared from two raw materials including a main phase alloy and an auxiliary phase alloy through double-alloy formation, the main phase alloy comprises a cerium element, and the auxiliary phase alloy comprises a cobalt element; through the addition of the cobalt element, the precipitation of the CeFe2 phase can be reduced, a new main phase is formed, the main phase volume ratio of the permanent magnet is increased, the problem of magnetic performance deterioration caused by the addition of the cerium element is avoided, and the prepared cerium-containing rare earth permanent magnet has high coercive force.

The invention discloses a grain boundary diffusion material, a diffusion magnet and a method. The grain boundary diffusion material comprises R, M1 and M2, wherein R is selected from at least one of Pr, Nd, Dy and Tb and must contain heavy rare earth elements; m1 is selected from at least one of Zr, Hf, Ta and Nb; m2 is selected from two of Al, Cu, Ga and Mg and must contain Cu; a rare earth alloy film formed by the grain boundary diffusion material has the following composition: RxM1yM2z, x is the weight part of the element R, y is the weight part of the element M1, z is the weight part of the element M2, and the content of Cu is greater than z / 2; based on 100 parts by weight of the rare earth alloy film, x is 60-75 parts by weight, y is 3.5-15 parts by weight, and z is 10-36.5 parts by weight. The grain boundary diffusion material disclosed by the invention is beneficial to greatly improving the coercive force of the magnet.

The invention relates to a method for controllably preparing a magnetic nanofiber film by current regulation and control magnetic field assisted electrospinning, which comprises the following steps: weighing PAN white powder, dissolving in a DMF organic solvent, continuously stirring by magnetic field force, and carrying out ultrasonic dispersion treatment on the solution by using an ultrasonic cleaner to prepare a uniformly dispersed PAN / DMF solution; adding Fe3O4 nanoparticles and a dispersing agent Triton X-100 with the same amount as the Fe3O4 nanoparticles into the prepared solution, and performing ultrasonic dispersion treatment to form a uniformly dispersed magnetic electrostatic spinning solution; according to the prepared magnetic electrostatic spinning solution, a thin and uniform high-performance magnetic nanofiber sample is prepared through a controllable magnetic field generated by a current control electromagnetic lens to assist an electrostatic spinning device, the thin and uniform high-performance magnetic nanofiber sample is placed in a drying box to be dried, and the thin and uniform high-performance magnetic nanofiber sample with the reduced deposition circle area, the increased thickness, the increased mechanical property, the improved magnetic property and the high-performance magnetic performance is obtained. The average diameter of the nanofibers is reduced and the nanofibers are uniform.

The invention discloses a preparation method for controlling magnet performance through a forming process, and belongs to the technical field of sintered neodymium-iron-boron permanent magnet materials. The method comprises the steps that S1, an upper pressing head assembly moves upwards to a preset powder adding position on a mold, and then sintered neodymium-iron-boron powder is quantitatively added into the mold; s2, the upper pressure head assembly moves downwards to a preset micro-descending position on the mold; s3, the lower pressing head assembly moves downwards and moves to a preset pre-pressing position on the grinding tool, and the sintered neodymium iron boron powder in the mold is pre-pressed; s4, after pre-pressing of the sintered neodymium iron boron powder is completed, magnetizing orientation operation is conducted on the sintered neodymium iron boron powder in the mold; s5, after the magnetizing orientation operation is completed, the upper pressing head assembly and the lower pressing head assembly synchronously move towards the middle of the mold, and the sintered neodymium-iron-boron powder is subjected to bidirectional opposite pressing; and S6, after the sintered neodymium-iron-boron powder is pressed, demagnetization operation is carried out. The technical scheme is used for solving the problem that powder distribution in a die cavity is not uniform when neodymium iron boron powder is pressed and sintered.

The invention discloses a method for improving coercive force of a neodymium-iron-boron magnet. The method comprises the following steps: taking raw materials of each element of the neodymium-iron-boron magnet according to a component proportion, and smelting and casting to obtain a throwing sheet; performing vacuum heat treatment on the throwing sheet at the temperature of 450-600 DEG C, performing hydrogen demolishing and airflow grinding on the throwing sheet subjected to vacuum heat treatment to obtain powder, performing orientation molding on the powder to obtain a green body, performing cold isostatic pressing on the green body, and finally performing vacuum sintering to obtain the neodymium-iron-boron magnet. Heat treatment below the ternary eutectic temperature is carried out on the throwing piece, distribution of a rare earth-rich phase in the throwing piece is improved through solid-phase diffusion, the rare earth-rich phase extends to the periphery of a columnar crystal, blocky rare earth-rich phases are reduced, rare earth loss in the jet milling stage is reduced, components are closer to nominal components, and the rare earth loss is reduced. And the proportion of rare earth-rich phases attached to the surfaces of airflow fine powder particles is increased, so that the coercive force of the sintered magnet is improved.

The invention provides a diffusion source and a grain boundary diffusion process, and relates to the technical field of permanent magnet grain boundary diffusion. The diffusion source is prepared by adopting DyF3 and Sn as diffusants and mixing a curing agent and a dispersing agent, and the diffusion source is used for stacking and coating magnetic sheets and then carrying out primary heat treatment at 950-1000 DEG C and secondary heat treatment at 680-700 DEG C to complete grain boundary diffusion. According to the method, the defects in the prior art are overcome, the diffusion source and the grain boundary diffusion process are suitable for industrial application, effective diffusion of DyF3 on the thick magnet is achieved, the corresponding grain boundary diffusion neodymium-iron-boron magnet is provided, and the magnetic performance of the magnet is effectively improved.

The present invention relates to a neodymium iron boron rare earth magnet and a preparation method thereof, and relates to the technical field of rare earth magnet preparation. By designing the coordinated diffusion of a diffusion source and a magnet, diffusion and aging treatment are performed to obtain a high-performance heavy rare earth-free magnet. The diffusion source is prepared by coating a layer of heavy rare earth-free alloy film on a diffusion source sheet, and performing aging treatment to form a new type of diffusion source, wherein the diffusion source sheet is R α RH δ M β B γ Fe 100‑α‑β‑γ‑δ The heavy rare earth-free film is a film with the chemical formula R n M m , aging treatment is carried out to form a new diffusion source; the chemical formula of NdFeB magnet is R a M 1b M 2c B d Fe 100‑a‑b‑c‑d After the magnet is diffused with Dy diffusion source, the remanent magnetism decreases by less than 0.15kGs, and the Hcj increases by more than 8kOe. After the magnet is diffused with Tb diffusion source, the remanent magnetism decreases by less than 0.15kGS, and the Hcj increases by more than 11kOe.

The invention aims to design a composite material capable of improving a magnetic exchange bias field. The material is a porous nano alpha-Fe2O3 / g-C3N4 composite material capable of improving the magnetic exchange bias field, which is synthesized by loading g-C3N4 on an ordered alpha-Fe2O3 nanowire. The method is simple to operate, environment-friendly and low in energy consumption; the porous nano composite material prepared by the method has a relatively high specific surface area, and meanwhile, the composite material has more surface disordered spinning, so that the blocking temperature and coercive force of the composite material are improved, the exchange bias field of the composite material is improved, and the composite material has a relatively good practical utilization prospect.

The invention discloses a high-resistivity sintered NdFeB permanent magnet material and a preparation method thereof, which relates to the technical field of permanent magnet materials. The material is prepared from the following raw materials in parts by mass: 95.0-99.9 parts of base alloy fine powder, 0.1-5 parts of rare earth fluoride powder, 0.1-0.3 parts of antioxidant, 0.2-1.2 parts of lubricant, 0.2-5 parts of aviation gasoline and 0.1-0.5 parts of nanomaterial; the composition of the base alloy fine powder is (PrNd) a (TM) b (HM) c Ga d B e Fe 100‑a‑b‑c‑d‑e , 29.5≤a≤32.5, 0<b≤5, 0<c≤0.8, 0.3≤d≤0.5, 0.88≤e≤0.94, wherein TM is one or more of Al, Cu, Co, and Mn, and HM is one or more of Nb, Zr, Hf, Ti, and V. The permanent magnetic material has high resistivity and excellent comprehensive magnetic properties.

The invention discloses a self-adaptive control system and method for neodymium-iron-boron sheet production, and relates to the technical field of material preparation and processing.The self-adaptive control system comprises a smelting analysis module, a rotating speed analysis module, an iron-boron alloy powder particle analysis module, a sintering temperature and duration analysis module, a neodymium-iron-boron sheet quality analysis module and a database; according to the method, various historical customer orders are combined, the appropriate smelting temperature and duration of the customer orders and the viscosity of neodymium iron boron alloy liquid based on the customer orders are obtained through analysis, the rotating speed of a melt-spinning machine is analyzed, parameters such as pressing pressure, sintering temperature and duration are determined according to the granularity of neodymium iron boron alloy powder, and finally the quality of the neodymium iron boron sheet is analyzed. And due to high intelligence and automation, the production efficiency is greatly improved, and the quality and consistency of products are ensured.

The invention discloses a double-alloy sintered neodymium-iron-boron permanent magnet and a preparation method and application thereof, and relates to the technical field of rare earth permanent magnet materials. Comprising the following steps that a main alloy and an auxiliary alloy are evenly mixed and then subjected to orientation profiling, cold isostatic pressing, liquid phase sintering and tempering heat treatment in sequence, the double-alloy neodymium iron boron permanent magnet is prepared, the chemical composition of the auxiliary alloy is AlxRE2yM100-x-y, RE2 is selected from one or more combinations of Ce, Dy, Gd, Ho, La, Nd, Pr, Tb and Y, and M is selected from any one or more combinations of Co, Cu, Ga, Ti, Zr and Nb; x and y satisfy 5 < = x < = 50 and 20 < = y < = 80; according to the method, on the premise that the magnetic performance of the neodymium iron boron permanent magnet is synchronously optimized, the mechanical performance of the neodymium iron boron permanent magnet is further improved, the mechanical performance and the magnetic performance of the sintered magnet have good consistency and stability, the technological method is simple and easy to implement, and the method is suitable for industrial production.

This invention belongs to the field of permanent magnet materials technology, specifically relating to a high-lanthanum-cerium NdFeB sintered permanent magnet and its preparation method. The raw materials for preparing this high-lanthanum-cerium NdFeB sintered permanent magnet include alloy one and alloy two. The chemical formula of alloy one is [(PrNd)]. 1‑x (RL) x ] a (TM) b (HM) c B d Fe 100‑a‑b‑c‑d Given the following conditions: 0.3 ≤ x < 1, 29.5 ≤ a ≤ 32.5, 0 < b ≤ 5, 0 < c ≤ 0.8, 0.85 ≤ d ≤ 1.1, the chemical formula of the alloy component II is (PrNd). a1 Ga b1 Fe 100‑a1‑b1 70≤a1≤90, 0<b1≤20. By combining alloy one and alloy two, and combining them with appropriate sintering and aging processes, high lanthanum-cerium NdFeB sintered permanent magnets are obtained, achieving surface magnetic hardening of high lanthanum-cerium main phase grains.

This invention discloses a high-coercivity hard magnetic oxide semiconductor thin film with perpendicular magnetic anisotropy and its preparation method. The invention employs a multi-target alternating gradient film preparation process, using NiFeO4 and NiCo2O4 targets for alternating sputtering to prepare NiCo2-xFexO4-NiCo2O4 gradient thin films. Experimental results show that the obtained films exhibit a coercivity as high as 1T and good conductivity, with an anomalous Hall resistivity reaching 52.5 μΩ·cm. This preparation method has the advantages of simplicity and low cost, providing new possibilities for the development of magnetic storage devices. This method has significant application potential for realizing high-density, high-speed, and low-power magnetic storage devices, contributing to the development and application of magnetic storage technology.

The present invention belongs to the technical field of permanent magnetic materials, and relates to a heavy rare earth-free high-performance lanthanum-cerium rare earth permanent magnet and a manufacturing method thereof. The chemical composition of the lanthanum-cerium rare earth permanent magnet is expressed as: [(R1) 1‑x (R2) x ] a M1 b M2 c M3 d B e Fe 1‑a‑b‑c‑d‑e , wherein: 10%≤x≤25%, 29.5%≤a≤32.5%, 1%≤b≤2%, 0.5%≤c≤1%, 0%<d<2.5%, 0.85%≤e≤0.95%, wherein R1 is one or both of Pr and Nd, R2 is one or both of La and Ce, M1 is Cu and Ga, M2 is Nb and Zr, and M3 is one or more of Al, Co, and Mn. The present invention reasonably controls the composition of the permanent magnet to obtain a high-performance lanthanum-cerium magnet without adding heavy rare earth elements, effectively reduces the production cost of the magnet, and broadens the application of the lanthanum-cerium magnet in the market.

The present invention provides: a Nd-Fe-B multilayer sintered magnet which is magnetically uniform, while having high magnetic characteristics; and a method for producing the Nd-Fe-B sintered magnet without performing a cutting step. The method of the present invention comprises the steps of: producing a Nd-Fe-B thin plate-shaped sintered magnet in which the c-axis direction of an Nd2Fe14B tetragonal compound is oriented within the main surface of the Nd-Fe-B thin plate-shaped sintered magnet, and which has a high degree of orientation of 90% or more and a thickness of 3 mm or less, without performing a cutting step, by supplying and filling an alloy powder into a mold having a structure partitioned by a plurality of partition plates arranged at a predetermined interval, applying a magnetic field in a direction parallel to a main surface of a cavity partitioned by the partition plates to orient the alloy powder, and then performing sintering, and laminating a plurality of Nd-Fe-B thin plate-shaped sintered magnets obtained by the above step.