Abstract: The present disclosure relates to the technical field of neodymium-iron-boron preparation, in particular to a method for improving the coercivity of a neodymium-iron-boron magnet and a magnet prepared by the method. The method specifically includes: (S1) subjecting a heavy rare earth diffusion source powder, an organic adhesive, a spherical high temperature resistant ceramic powder and an organic solvent to mixing and stirring to prepare a heavy rare earth slurry; (S2) coating a surface of a neodymium-iron-boron magnet with the heavy rare earth slurry and drying the heavy rare earth slurry to form a heavy rare earth coating; and (S3) performing high-temperature diffusion and aging treatment. According to the method above, the heavy rare earth coating has high hardness and strength. In addition, the neodymium-iron-boron magnet has higher and more uniform properties after diffusion, and less heavy rare earth elements are consumed.

Abstract: The invention relates to a method of increasing the coercivity of a sintered type NdFeB permanent magnet. The method comprises the following steps: a) preparing of an organic film with a predetermined thickness on a surface of the sintered type NdFeB permanent magnet; b) creating holes in the organic film according to a given pattern with the holes extending to the surface of the sintered type NdFeB permanent magnet; c) filling the holes with a metal powder, the metal powder including or consisting of at least one of Dy and Tb; and d) performing a thermally induced grain boundary diffusion process.

Abstract: The disclosure refers to a NdFeB alloy powder for forming high-coercivity sintered NdFeB magnets. The NdFeB alloy powder includes NdFeB alloy core particles with a multi-layered coating, wherein the multi-layered coating comprises: a first metal layer directly disposed on the NdFeB alloy core particles, wherein the first metal layer consists of at least one of Tb and Dy; a second metal layer directly disposed on the first metal layer, wherein the second metal layer consists of at least one of W, Mo, Ti, Zr, and Nb; and a third metal layer directly disposed on the second metal layer, wherein the third metal layer consists of (i) at least one of Pr, Nd, La, and Ce; or (ii) a combination of one of the group consisting of Cu, Al, and Ga and at least one of the group consisting of Pr, Nd, La, and Ce.

Abstract: The present disclosure discloses a cerium-added RE-T-B-M series sintered neodymium-iron-boron magnet, which relates to the technical field of neodymium-iron-boron permanent magnets, the structure of the magnet contains a RE2Fe14B main phase, a RE-rich phase, a REFe2 phase, and a sandwich grain boundary phase, wherein the sandwich grain boundary phase includes a RE-rich phase, a Fe-rich phase, and a REFe2 phase, and in the sandwich grain boundary phase, starting from the side near the grains of RE2Fe14B main phase, the first layer is the RE-rich phase, the second layer is the Fe-rich phase, and the third layer is the REFe2 phase, where RE includes cerium element and at least one of other rare earth elements, and the cerium element accounts for 3.0-15.0% by mass of the total elements, T is iron element and cobalt element, B is boron element, and M is Al, Cu, Ga, and Ti elements.

Abstract: The disclosure relates to a preparation device and method of forming a ceramic coating on a sintered type NdFeB permanent magnet. The preparation device comprises a holding barrel, a pump body, a spraying system, and a fixture mechanism. The pump body is connected with the holding barrel and the spraying system and the spraying system is located above the fixture mechanism and there is a distance between the spraying system and the fixture mechanism. The fixture mechanism is connected with a recovery bucket through a pipeline, and the recovery bucket is connected with the holding barrel through the pipeline. The spraying system comprises a nozzle, wherein the inlet of the nozzle is connected with the pipeline of the pump body. The fixture mechanism comprises a support plate, an upper recovery trough plate and a lower recovery trough plate, wherein the lower recovery trough plate is located above the support plate.

Abstract: The disclosure provides a preparation method, which comprises: providing a moulding die for a ring-shaped sintered Nd—Fe—B magnet; placing a Nd—Fe—B magnetic powder into the mould cavity of the moulding die in a loosely packed state, the loosely packed height of the Nd—Fe—B magnetic powder is L; placing a flexible cylindrical core into the loosely packed Nd—Fe—B magnetic powder at a L/2 position, wherein an axial direction of the flexible cylindrical core is horizontal and parallel to the direction of a magnetic field in the mould cavity; applying a vertical pressure to the Nd—Fe—B magnetic powder to obtain a ring-shaped green block assembly with the flexible cylindrical core embedded; after encapsulating and isolating the ring-shaped green block assembly, applying an isostatic pressure to the ring-shaped green block assembly; sintering the ring-shaped green block assembly to obtain a ring-shaped sintered blank; thermally aging, grinding and slicing the ring-shaped sintered blank.

Abstract: The present disclosure provides a method for preparing a high-coercivity sintered NdFeB magnet. The method including the steps of: S1, Providing a NdFeB powder as a main material; S2, Vacuum coating a layer of a rare earth alloy RxH(100-x) on a surface of a metal nano-powder M to obtain an auxiliary alloy material with a core-shell structure, with R being selected from one or more of Dy, Tb, Pr, Nd, La, and Ce; H being selected from one or more of Cu, Al, and Ga; the nano-powder M being selected from one or more of Mo, W, Zr, Ti, and Nb; 0?x?90 wt. %; S3, Adding the auxiliary alloy material obtained by step S2 to the NdFeB powder of step S1 and mixing, then orientation pressing of the mixture to obtain a compact body; and S4, Sintering and annealing treatment of the compact body to obtain the high-coercivity sintered NdFeB magnet.

Abstract: The present disclosure provides an NdFeB rare earth magnet and manufacturing method thereof, which belongs to the field of rare earth magnet technology. The production method of diffusion source is to coat a layer of non-heavy rare earth alloy film on the diffusion source sheet, and aging treatment are carried out to form diffusion source. The diffusion source is R?RH?M?B?Fe100-?-?-?-?. The chemical formula of the non-heavy rare earth alloy film is RnMm. The chemical formula of NdFeB magnet base material is RaM1bM2cBdFe100-a-b-c-d. The performance NdFeB by diffusion source containing Dy have ?Hcj>636.8 kA/m and containing Tb have ?Hcj>875.6 kA/m, containing DyTb have ?Hcj>716.4 kA/m.

Abstract: The present disclosure provides a rare earth magnet and manufacturing method thereof, which belongs to the field of rare earth magnet technology. The diffusion source is coated on the NdFeB base material, which is diffused and aged to obtain NdFeB magnet. The diffusion source alloy is R?M?B?Fe100-?-?-?, wherein R refers to at least one of Nd and Pr, and M Refers to at least one of Al, Cu, Ga. The Br reduction range is lower than 0.03 T, and Hcj growth is more than 318 kA/m.

Abstract: The disclosure relates to a method for improving the coercivity of an arc-shaped Nd—Fe—B magnet. A method for increasing the coercivity of an arc-shaped Nd—Fe—B magnet is provided. Said method comprises the steps of: a) providing of a flexible film with a heavy rare earth coating thereon, wherein the heavy rare earth coating comprises at least one of Dy and Tb; b) arranging the arc-shaped Nd—Fe—B magnet and the flexible film such that a first curved surface of the arc-shaped Nd—Fe—B magnet and the heavy rare earth coating on the flexible film are facing each other; such that a curved surface of the first ceramic body lies on the side of the flexible film opposite the arc-shaped Nd—Fe—B magnet, then pressing the first ceramic body and the magnet together; and d) performing a thermally induced grain boundary diffusion process.

Abstract: The present disclosure refers to a method for preparing sintered NdFeB magnets, including: a) Preparing alloy flakes from a raw material by strip casting, performing a hydrogen decrepitation to produce alloy pieces, pulverization the alloy pieces to an alloy powder, performing molding and orientation, cold isostatic pressing, and getting a green compact; b) Putting the green compact into a vacuum furnace and performing a first sintering step in 830 to 880° C. for 2 to 10 hours and 5×10?1 Pa or less; c) Performing a second sintering step while applying a pressure to the green compact achieved by step b), the pressure is 1 MPa to 5 MPa and the sintering temperature is 720 to 850° C. for 15 to 60 minutes, and the temperature of the first sintering step is at least 10° C. higher than that of the second sintering step; d) Subjecting the sintered magnet of step c) to an annealing treatment.

Abstract: The disclosure discloses a NdFeB permanent magnet and a preparation method thereof. The magnet is composed of main phase I, a shell structure, a grain boundary phase adjacent to the shell structure, a main phase II, a Ga rich region and a Cu rich region. The magnet has high remanence, high coercivity, and high magnetic energy. In addition, this method can significantly reduce the production cost.

Abstract: The disclosure relates to a method of preparing a low-heavy rare earth magnet comprising the following steps: S1, smelting and strip casting of the raw materials of a NdFeB alloy to obtain a NdFeB alloy sheets, and mechanically crushing the NdFeB alloy sheets into flaky alloy sheets; S2, mechanically mixing the flaky alloy sheets, a low melting point powder and a lubricant to obtain a mixture, followed by hydrogen absorption and dehydrogenation treatment of the mixture and jet milling of the product to obtain a NdFeB magnet powder; S3, pressing, forming and sintering the NdFeB magnet powder to obtain a sintered NdFeB magnet; S4, mechanically processing the sintered NdFeB magnet to a desired shape, and then forming a diffusion source film on the surface of the sintered NdFeB magnet; and S5, performing a diffusion process and aging to obtain the low-heavy rare earth magnet.

Abstract: The disclosure relates to the technical field of sintered type NdFeB permanent magnets, in particular to a low-cost rare earth magnet and manufacturing method. There is provided a method of preparing a high-coercivity, sintered NdFeB magnet including cerium comprising the following steps: (S1) Providing alloy flakes composed of RxT(1-x-y-z)ByMz; (S2) Mixing the alloy flakes, a low melting point powder, and a lubricant, then subjecting the mixture to a hydrogen embrittlement process followed in this order by pulverizing the process product to an alloy powder by jet milling, magnetic field orientation molding of the alloy powder to obtain a blank, sintering and aging treatment the blank; (S3) Coating a film composed of a diffusion source of formula R1xR2yHzM1-x-y-z on the sintered NdFeB magnet; and (S4) Performing a diffusion heat treatment, followed by aging the sintered NdFeB magnet to obtain the low-cost rare earth magnet.

Abstract: The disclosure refers to a method for preparing NdFeB magnets including at least one of Ce and La. The method includes: S1) Separately preparing flakes of alloy R1 and flakes of alloy R2 each by a strip casting process, wherein the alloy R1 includes at least one of La and Ce, but the alloy R2 does not include La and Ce; S2) separately subjecting the flakes of alloy R1 and R2 to a hydrogen embrittlement process followed by pulverizing the process product to alloy powders by jet milling, wherein a ratio of the average particle sizes D50 of the powder of alloy R1 and R2 satisfied formula: 0.32?R2/R1?0.66; S3) mixing the powder of alloy R1 and R2; and S4) subjecting the mixed powders to molding and magnetic field orientation, cold isostatic pressing, sintering, and an annealing process.

Abstract: The present disclosure relates generally to a method for improving the performance of sintered NdFeB magnet. A method of preparing a sintered NdFeB magnet therefore comprises the steps of: a) preparing alloy flakes from a raw material of the NdFeB magnet by a strip casting process; and b) preparing a coarse alloy powder from the alloy flakes by a hydrogen decrepitation process, the hydrogen decrepitation process including treatment of the alloy flakes under a hydrogen pressure of 0.10 MPa to 0.25 MPa for a duration of 1 to 3.5 hours, then degassing the hydrogen at a predetermined temperature between 300° C. to 400° C. for a duration time of 0.5 to 5 hours, and then mixing the resulting coarse alloy powder with a lubricant.

Abstract: The present disclosure provides a method for preparing a high-coercivity sintered NdFeB magnet. The method including the steps of: S1, Providing a NdFeB powder as a main material; S2, Vacuum coating a layer of a rare earth alloy RxH(100-x) on a surface of a metal nano-powder M to obtain an auxiliary alloy material with a core-shell structure, with R being selected from one or more of Dy, Tb, Pr, Nd, La, and Ce; H being selected from one or more of Cu, Al, and Ga; the nano-powder M being selected from one or more of Mo, W, Zr, Ti, and Nb; 0?x?90 wt. %; S3, Adding the auxiliary alloy material obtained by step S2 to the NdFeB powder of step S1 and mixing, then orientation pressing of the mixture to obtain a compact body; and S4, Sintering and annealing treatment of the compact body to obtain the high-coercivity sintered NdFeB magnet.

Abstract: The disclosure refers to a preparation method for NdFeB permanent magnet including: a) Preparing main alloy flakes consisting of (Pr2Nd8)xFe100-x-y-zByMz,where M is at least one of Al,Co,Cu,Ga,Ti and Zr, 28.5 wt. % ?x?31.0 wt. %,0.85 wt. %?y?0.98 wt. % and 0.5 wt. %?z?5.0 wt. %; b) Preparing auxiliary alloy flakes consisting of LuFe100-u-v-wBvMw,where L is at least one ofPr and Nd,M is at least one of Al,Co,Cu,Ga,Ti and Zr, 35.0 wt. %?u?45.0 wt. %,0 wt. %?v?5.0 wt. % and 2.0 wt. %?w?10.0 wt.

Abstract: The present disclosure refers to a method for preparing sintered NdFeB magnets, including: a) Preparing alloy flakes from a raw material by strip casting, performing a hydrogen decrepitation to produce alloy pieces, pulverization the alloy pieces to an alloy powder, performing molding and orientation, cold isostatic pressing, and getting a green compact; b) Putting the green compact into a vacuum furnace and performing a first sintering step in 830 to 880° C. for 2 to 10 hours and 5×10?1 Pa or less; c) Performing a second sintering step while applying a pressure to the green compact achieved by step b), the pressure is 1 MPa to 5 MPa and the sintering temperature is 720 to 850° C. for 15 to 60 minutes, and the temperature of the first sintering step is at least 10° C. higher than that of the second sintering step; d) Subjecting the sintered magnet of step c) to an annealing treatment.

Abstract: A method of increasing coercivity of a sintered Nd—Fe—B permanent magnet includes a first step of providing a sintered Nd—Fe—B magnet block having a pair of block surfaces extending perpendicular to a magnetization direction. The method then proceeds with depositing an organic adhesive layer on one of the block surfaces. Next, the method proceeds with depositing a powder containing at least one heavy rare earth element on the organic adhesive layer. After depositing the powder, the sintered Nd—Fe—B magnet block is pressed to adhere the powder to the organic adhesive layer. Then, the method follows with a step of removing excess powder from the sintered Nd—Fe—B magnet block to form a uniform film. Then, the powder is diffused into the sintered Nd—Fe—B magnet is diffused into the sintered Nd—Fe—B magnet block to produce a diffused magnet block. Next, the method proceeds with aging the diffused magnet block.