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 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 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 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 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: 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.

Abstract: The disclosure relates to a method for preparing sintered type NdFeB permanent magnet. The NdFeB magnet is covered with a diffusion source to form a NdFeB magnet intermediate. The diffusion source refers to an alloy, the alloying elements include one or more of Nd, Pr, Ce, La, Ho, Tb, Dy, Ga, Al, Cu, and Mg. The NdFeB magnet intermediate is then put into a furnace and a diffusion treatment and subsequently an aging treatment is performed. The aging treatment is divided into a heating step and a cooling step. The cooling step is carried out by means of argon gas positive pressure circulation cooling such that NdFeB magnets with a thickness of grain boundaries in the range of 10 nm to 1 ?m are formed.

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: A method of increasing coercivity of an Nd—Fe—B sintered permanent magnet includes a step of providing an organic film. A powder, containing at least one heavy rare earth elements, is uniformly deposited on the organic film forming a diffusion source. Then, a sintered Nd—Fe—B magnet block having a pair of block surfaces extending perpendicular to a magnetization direction is provided. Next, the diffusion source is deposited on at least one of the block surfaces with the powder being in abutment relationship with at least one of the block surfaces. After depositing the diffusion source, the sintered Nd—Fe—B magnet block containing the diffusion source is pressed allowing the powder of the diffusion source to be in close contact with the block surface. The diffusion source is then diffused into the sintered Nd—Fe—B magnet block to produce a diffused magnet block. Next, the diffused magnet block is aged.

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 disclosure provides a novel NdFeB alloy powder for forming high-coercivity sintered NdFeB magnets. The NdFeB alloy powder includes NdFeB alloy core particles with a mixed metal coating. The mixed metal coating is formed by simultaneously vapor deposition of a) at least one high-melting metal M selected from the group consisting of Mo, W, Zr, Ti, and Nb; and b) at least one metal R, where R is selected from the group consisting of Pr, Nd, La, and Ce; or a metal alloy RX, where X is one selected from the group consisting of Cu, Al, and Ga and R is at least one selected from the group consisting of Pr, Nd, La, and Ce.

Abstract: Some embodiments of the invention belongs to a technical field of NdFeB magnet processing, and mainly relates to a device and method for improving the coercivity of ring-shaped NdFeB magnet. A layer of heavy rare earth coating is sprayed on the inner and outer surfaces of the ring-shaped NdFeB magnet by the device, and then the ring-shaped NdFeB magnet sprayed with the heavy rare-earth coating is subjected to diffusion treatment to improve the coercivity of the ring-shaped NdFeB magnet. The invention uses heavy rare earth slurry as the diffusion source, combined with spraying technology, can quickly and uniformly cover a layer of heavy rare earth coating on the inner and outer surfaces of the ring-shaped NdFeB magnet, and the coercivity of the ring-shaped NdFeB magnet is improved after heat treatment.

Abstract: A method of improving coercivity of an Nd—Fe—B magnet includes a first step of providing an Nd—Fe—B magnet having a first surface and a second surface. Next, a first solidified film of at least one pure heavy rare earth element is formed and attached to the first surface of the Nd—Fe—B magnet to prevent a reduction in corrosion resistance caused by oxygen and fluorine and hydrogen. After forming the first solidified film, the Nd—Fe—B magnet is subjected a diffusion treatment in a vacuum or an inert atmosphere. After the diffusion treatment, the Nd—Fe—B magnet is subjected to an aging treatment in the vacuum or the inert atmosphere.

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.