21 results about "Sintered magnets" patented technology

This invention discloses an R-T-B sintered magnet with reduced eddy current losses, its preparation method, and its application. The magnet has partition grooves on one or two orientation surfaces, where each orientation surface is perpendicular to the orientation direction of the magnet. The partition grooves extend through the magnet in a first extension direction but not in a second extension direction. The first extension direction of the partition grooves is perpendicular to the orientation direction of the magnet, and the second extension direction is parallel to the orientation direction of the magnet. By creating crisscrossing partition grooves on the magnet and filling them with an insulating layer, this invention increases the resistivity of a thin layer on the magnet's surface by a certain thickness, significantly reducing motor power loss due to eddy current effects. The insulating layer filling the grooves increases the resistivity of both the magnet surface and the grooves, effectively preventing conduction due to poor processing or current breakdown when the groove width is narrow. It also compensates for the reduction in mechanical strength caused by the grooving, ultimately resulting in a low-eddy-current, high-strength sintered magnet.

To provide an R-Fe-B sintered magnet that exhibits high coercivity while keeping material costs down. [Solution] The R-Fe-B sintered magnet contains a rare earth element R including Tb, an element T consisting of Fe or a combination of Fe and Co, B, and each of Al, Cu, and Ga, with an element M consisting of a combination of Al, Cu, and Ga, and includes an RTM phase in the grain boundary phase, where the number of atoms of element M in the RTM phase is in the order of Cu > Al > Ga. Furthermore, in the RTM phase, the atomic ratio of the rare earth element R to element M is preferably 6.0 for the rare earth element R and 1.3 or more for element M.

A method for cleaning rare earth alloy powder, includes the steps of: mixing rare earth oxides, metals, and metal compounds as raw materials, and reducing the rare earth oxides chemically to produce alloy powder that contains the reduced rare earth elements in alloy form; and cleaning the alloy powder, where the cleaning step include the steps of adding the alloy powder in a solution containing an aliphatic organic acid and an organic acid ammonium salt and removing components other than those constituting the alloy powder from the added alloy powder by the organic acid ammonium salt.

A method for producing an R-T-Q system sintered magnet according to the present disclosure comprises: a pulverization step in which an alloy powder is formed by pulverizing an R-T-Q system magnet alloy; and a step in which an R-T-Q system sintered magnet is formed by sintering a molded body of the alloy powder. The R content is 30 mass% or less, the B content is 0.90 mass% or less, and the total content of B and C is 0.99 mass% or less. The pulverization step comprises a hydrogen pulverization step and a fine pulverization step, and the hydrogen pulverization step comprises: a hydrogen storage step in which hydrogen is stored in the alloy at a temperature of 200°C or less within a processing chamber; and a dehydrogenation step in which a dehydrogenation treatment is carried out by discharging hydrogen from the processing chamber and heating the alloy to a temperature within the range from 80°C to 350°C, thereby forming a coarse pulverized powder that has a hydrogen content of 1,000 ppm to 2,000 ppm. In the fine pulverization step, a fine powder having a median diameter d50 of 3.5 µm or less is obtained by pulverizing the coarse pulverized powder.

A sintered magnet including one or more rare-earth elements is partitioned into three or more magnets. The three or more magnets include pair of first magnets disposed at ends of the sintered magnet and made of a first material, and a second magnet made of a second material different from the first material. By applying a permanent with a high coercive specification to the ends relatively vulnerable to a reverse magnetic field and applying a permanent with a low coercive force specification in comparison to the edges to a central portion thereof, it is possible to reduce the use of heavy rare-earth elements and manufacturing process cost for manufacturing partitioned magnets.

Disclosed is an Sm-Fe-N-based sintered magnet that comprises crystal grains which contain samarium, iron, and nitrogen and which include main phase grains that contain not less than 9 atom% but less than 13 atom% of samarium and sub-phase grains that contain 13 atom% or more of samarium, iron, and nitrogen. The ratio (M2 / M1) of the average value M2 of the X-ray magnetic circular dichroism intensities of the iron of the sub-phase grains to the average value M1 of the X-ray magnetic circular dichroism intensities of the iron of the main phase grains, which is obtained in a plane that is perpendicular to the easy axis of magnetization in an environment in which a static magnetic field of 4T is applied in a direction that is parallel to the direction of the easy axis of magnetization is 10% to 83% inclusive.

The present invention provides a rare earth sintered magnet which contains R (R represents one or more rare earth elements essentially including Nd), T (T represents one or more iron group elements essentially including Fe), B, M1 (M1 represents one or more elements selected from among Al, Si, Cr, Mn, Cu, Zn, Ga, Ge, Mo, Sn, W, Pb and Bi) and M2 (M2 represents one or more elements selected from among Ti, V, Zr, Nb, Hf and Ta), while comprising an R2T14B phase as the main phase. This rare earth sintered magnet is characterized in that: the M1 is in an amount of from 0.5% by atom to 2% by atom; if (R), (T), (M2) and (B) are the respective atomic percentages of the above-described R, T, M2 and B, the relational expression (1) ((T) / 14)+(M2)≤(B)≤((R) / 2)+((M2) / 2) is satisfied; and from 0.1% by volume to 10% by volume of all grain boundary phases in the magnet is composed of an R6T13M1 phase. This rare earth sintered magnet is able to achieve excellent magnetic characteristics including a good balance between high Br and high HcJ.

The present invention pertains to a method for producing a sintered magnet containing a manganese-aluminum alloy, the method comprising (i) preparing magnetic particles having a manganese-aluminum alloy containing a τ phase, (ii) molding the magnetic particles to form a molded body, and (iii) sintering the molded body in a predetermined temperature range while a predetermined pressure is applied, wherein a sintered body obtained after (iii) has a plurality of domains in a predetermined observation region in a cross-sectional view, and some of the domains have a predetermined crystal structure portion.

This invention provides a core-shell structure R-T-B rare earth permanent magnet with Gd-rich cores for high-temperature environments. In the magnet, the rare earth element R content is 29.0 wt.% to 34.0 wt.%, and R is composed of Gd and R1. The Gd element content is 1.0 wt.% to 20.0 wt.% of the magnet mass. The main phase grains contain main phase grains with a volume ratio of 20 vol.% to 80 vol.% of Gd-rich cores and Gd-poor shells. This invention employs a dual-alloy method to separately melt alloy sheets with high and low Gd contents, then prepares sintered magnets. During high-temperature diffusion treatment, Gd elements in the high-Gd-content main phase diffuse into the R-rich phase at the grain boundaries. Ultimately, the high-Gd-content main phase grains form an anti-shell structure with a Gd-depleted shell and a Gd-rich core. The Gd-depleted shell significantly reduces the degradative effect of Gd on the magnet's coercivity, thus fully utilizing the characteristics of Gd to prepare a magnet with a low temperature coefficient and high coercivity. Grain boundary diffusion treatment of Dy / Tb elements can further improve the magnet's coercivity, preparing R-T-B rare-earth permanent magnets suitable for higher operating temperatures.

This invention discloses a ferrite magnetic powder material and its preparation method that induces oriented alignment through wet ball milling, belonging to the field of new materials technology. The method addresses the problem that traditional wet ball milling cannot induce preferred grain alignment due to the isotropic nature of mechanical action. A coarse ferrite powder slurry is injected into a dedicated ball milling device. During the milling process, a rotating magnetic field is simultaneously applied and the grinding chamber is rotated to form a directional fluid shear field. A closed-loop control system maintains a fixed phase difference between the rotating magnetic field vector and the local fluid velocity vector, achieving spatiotemporal synchronization. Simultaneously, the slurry rheological properties, medium filling rate, and process parameters are precisely controlled. This magnetic powder exhibits significantly enhanced response capabilities in subsequent magnetic field orientation pressing, effectively improving the remanence of the final sintered magnet and reducing coercivity fluctuations, with excellent batch-to-batch consistency in magnetic properties.

The present invention discloses a method for manufacturing an RE-Fe—B-based sintered magnet and the RE-Fe—B-based sintered magnet manufactured using the method. The invention comprises: a step of preparing a mixed powder by mixing magnet powder containing RE-Fe—B-based grains with a heavy rare earth diffusion source, a step of pressing the mixed powder to produce a compact, a step of performing spark plasma sintering (SPS) on the compact to form a sintered body, and a step of heating the sintered body to diffuse the heavy rare earth diffusion source into the grain boundaries of the sintered body, wherein the grain size of the RE-Fe—B-based grains is controlled during the step of forming the sintered body.

The utility model relates to the technical field of inductance, provide a kind of copper iron co-fired inductance, including sintered magnet and conductor;The conductor is integrally formed structure, the conductor includes connecting portion and the end portion respectively connected in the both ends of connecting portion, the connecting portion of the conductor is located in the sintered magnet, the both ends of the conductor are exposed to sintered magnet, as terminal, and there is electroplating layer at terminal, forms electrode, the sintered magnet surface is provided with the recess for the terminal accommodation. Reduce electrode exposure, inductance has higher electromagnetic characteristic, to reduce inductance leakage flux, improve inductance performance.

The application discloses an ultrahigh-coercivity sintered Nd-Fe-B magnet and a preparation method thereof. The steps include: smelting alloy raw materials, and performing flake casting; sequentially performing heat treatment, hydrogen crushing, airflow milling, magnetic field forming, cold isostatic pressing treatment, and sintering to obtain a sintered Nd-Fe-B magnet one; depositing a non-rare earth target material on the surface of the sintered Nd-Fe-B magnet one by using a molecular beam epitaxy technology; performing grain boundary diffusion and heat treatment; depositing a heavy rare earth target material on the surface of the sintered magnet by using the molecular beam epitaxy technology to obtain a sintered Nd-Fe-B magnet two, performing grain boundary diffusion and heat treatment, and then performing a tempering process to obtain the sintered Nd-Fe-B magnet. The method realizes atomic-level film layer control by using the molecular beam epitaxy technology, overcomes the problem that it is difficult to obtain a uniform and thin diffusion layer by using a traditional coating method, can efficiently utilize diffusion materials, improves the uniform diffusion depth of heavy rare earth elements in the magnet, and prepares the ultrahigh-coercivity magnet, thereby meeting the needs of the rare earth permanent magnet motor industry.

The application belongs to the technical field of regenerative magnets, and relates to a high-performance rare earth neodymium-based regenerative magnet and a preparation method and application thereof. The application discloses a preparation method of a high-performance rare earth neodymium-based regenerative magnet, wherein different particle sizes of waste magnet coarse broken particles are processed in batches, the particle size of airflow grinding powder is effectively controlled, and thus the loss of rare earth is reduced; the obtained regenerative sintered magnet and the high-performance rare earth neodymium-based regenerative magnet basically recover comprehensive magnetic properties, and the temperature coefficient of the high-performance rare earth neodymium-based regenerative magnet is improved.

Disclosed is a method for improving the coercivity of a samarium-cobalt magnet, comprising the following steps: placing metal raw materials in a vacuum induction furnace according to a proportion to obtain an ingot by smelting, crushing the ingot to obtain alloy powder; molding the alloy powder in a magnetic field to obtain a green body by cold isostatic pressing; sintering the green body to obtain a sintered magnet by solid solution treatment; heating the sintered magnet to 400-800 DEG C at a heating rate of 50-150 DEG C / s in a heat treatment furnace, keeping the temperature for 30-300 s, and then cooling to room temperature at a cooling rate of 5-50 DEG C / s; and cooling the sintered magnet to room temperature after aging treatment to obtain a samarium-cobalt magnet, wherein the aging treatment comprises two steps, the first step is aging at a temperature of 810-900 DEG C for 5-40 h, and then the second step is aging at a temperature of 400 DEG C at a cooling rate of 0.7 DEG C / min for 1-20 h, and then cooling to room temperature to obtain the samarium-cobalt magnet.

The present invention provides an R-Fe-B-based sintered magnet which is characterized in that: R, B, Co, Ga, M1, M2, O, C, N, and Fe are contained at a specific ratio; the grain boundary phase includes an R-Fe(Co)-(Ga, M1) phase that contains the elements at a specific ratio; and when [Fe] is the concentration of Fe atoms with respect to the total amount of the elements in the phase, [Co] is the concentration of Co atoms with respect to the total amount of the elements in the phase, [Ga] is the concentration of Ga atoms with respect to the total amount of the elements in the phase, and [M1] is the concentration of M1 atoms with respect to the total amount of the elements in the phase, the relational expression 4.0 ≤ ([Fe] + [Co]) / ([Ga] + [M1]) ≤ 7.8 is satisfied.　It is possible to obtain an R-Fe-B-based sintered magnet that achieves both high Br and high HcJ at the minimum necessary Ga content by increasing the utilization efficiency of Ga.

To provide an R-T-B-based sintered magnet and its manufacturing method, capable of multipolar magnetization and of enlarging a generated magnetic field after magnetization even when the magnetization is performed in a small pole pitch.SOLUTION: An R-T-B-based sintered magnet (R stands for a rare earth element including Nd and T stands for a transition metal element including Fe) contains at least dysprosium (Dy) as a rare earth element. When a saturation remnant magnetization value of the R-T-B-based sintered magnet is B, and a magnetization value while applying an external magnetic field of 500 kA / m in an initial magnetization curve for the R-T-B sintered magnet is A, and a magnetization ratio is expressed as A / B, a magnetization ratio is less than 1.0 (but greater than 0). A pole pitch in the R-T-B sintered magnet is less than 4 mm (but greater than 0 mm).SELECTED DRAWING: None

The application relates to a preparation method of a high-abundance cerium magnet, and belongs to the technical field of rare earth permanent magnet materials. The method is used to solve at least one of the problems that the performance of the high-abundance cerium magnet prepared by the existing method is uneven, low cost and performance improvement cannot be simultaneously considered, the preparation process is unstable, the process is complex, and the production cost is high. In the application, the total amount of Ce / rare earth is controlled in a high proportion, and the component design of the composite element addition and the size of the rapid solidification casting piece and the particle size control of the fine powder are combined. The magnet prepared by the application can balance the cost and the performance, the controllable replacement of the typical praseodymium-neodymium element by the low-price high-abundance rare earth element is realized under the condition that the proportion of Ce is greater than or equal to 50%, the cost of the sintered magnet is maximally reduced, the formation of the soft magnetic impurity phase of the cerium magnet is inhibited through component optimization, the grain boundary phase structure is stabilized, and the high-abundance cerium magnet with high magnetic performance is obtained.

The present disclosure relates to a sintered Nd-Fe-B magnet and a method for preparing the sintered Nd-Fe-B magnet, the method comprising the following steps: S1, preparing a sintered Nd-Fe-B magnet substrate; S2, attaching a diffusion source containing RE to the surface of the sintered Nd-Fe-B magnet substrate, and then performing grain boundary diffusion treatment and tempering treatment; RE is Dy and / or Tb; wherein the grain boundary diffusion treatment comprises an initial diffusion heat treatment and N stages of diffusion process segments, N≥1, each stage of the diffusion process segment comprises, in sequence, a high-temperature diffusion heat treatment and a low-temperature diffusion heat treatment; the low-temperature diffusion heat treatment has a temperature of 850-950 ℃ and a time of 6-12 h; the high-temperature diffusion heat treatment has a temperature lower than the sintering temperature and 50-200 ℃ higher than the temperature of the low-temperature diffusion heat treatment, and a time of 2-8 h. The method can promote the diffusion of heavy rare earth elements to the central region of the sintered magnet in the grain boundary diffusion process, and further improve the comprehensive magnetic properties of the sintered Nd-Fe-B magnet.

An anisotropic rare earth sintered magnet represented by the formula (R1-aZra)x(Fe1-bCOb)100-x-y(M11-cM2c)y. R is Sm and at least one element selected from rare earth elements, M1 is at least one element selected from the group consisting of V, Cr, Mn, Ni, Cu, Zn, Ga, Al, and Si, M2 is at least one element selected from the group consisting of Ti, Nb, Mo, Hf, Ta, and W, and x, y, a, b, and c each satisfy 7≤x≤15 at %, 4≤y≤20 at %, 0≤a≤0.2, 0≤b≤0.5, and 0≤c≤0.9. The magnet includes 80% by volume or more of a main phase composed of a compound of a ThMn12 type crystal, the main phase having an average crystal grain size of 1 μm or more, and an intergranular grain boundary phase being formed between adjacent main phase grains.