The present disclosure discloses a sintered neodymium-iron-boron magnet and a preparation method thereof. The sintered neodymium-iron-boron magnet includes the following raw materials in mass percentage: 1%-40% of an iron powder or a steel powder with a magnetic induction intensity of more than 1.2 T, not more than 10% of a praseodymium-neodymium metal hydride powder, and a remainder of a neodymium-iron-boron fine powder, wherein the mass percentages of the above raw materials add up to 100%. The preparation method includes: weighing the raw materials in mass percentage; mixing the weighed raw materials uniformly, and then subjecting to magnetic-field press molding, isostatic pressing, sintering and tempering to obtain the sintered neodymium-iron-boron magnet.

Provided is a rare-earth anisotropic magnet powder capable of achieving high magnetic properties while reducing the usage of Nd and Pr. The present invention provides a rare-earth anisotropic magnet powder comprising magnetic particles that contain rare-earth elements, boron, and a transition metal element. The rare-earth elements include a first rare-earth element that comprises Ce and/or La and a second rare-earth element that comprises Nd and/or Pr. The rare-earth elements have a first ratio (R1/Rt) of 5% to 57%. The first ratio (R1/Rt) is a ratio of an amount (R1) of the first rare-earth element to a total amount (Rt) of the rare-earth elements in terms of the number of atoms. The first rare-earth element has a La ratio (La/R1) of 0% to 35%. The La ratio (La/R1) is a ratio of an amount of La to the amount (R1) of the first rare-earth element in terms of the number of atoms. The magnetic particles have a Ga content of 0.35 at % or less with respect to 100 at % as a whole. By adjusting the Ga content to a predetermined value or less, both the reduction of Nd (Pr) and the high magnetic properties can be achieved at a high level.

The present invention discloses manufacturing methods of a powder for compacting rare earth magnet powder and rare earth magnet that omit jet milling process, which comprises the steps as follows: 1) casting: casting the molten alloy of rare earth magnet raw material by strip casting method to obtain a quenched alloy with average thickness in a range of 0.20.4 mm; 2) hydrogen decrepitation: decrepitating the quenched alloy and a plurality of rigid balls into a rotating hydrogen decrepitation container simultaneously, the quenched alloy is crushed under a hydrogen pressure between 0.011 MPa, cooling the alloy and the balls, then screening the mixture to remove the rigid balls and obtain the powder. As the jet milling process is omitted, the oxygenation during the process of the jet milling may be avoided, therefore the process may be non-oxide, and the mass production of magnet with super high property may be possible.

A method of processing NdFeB magnetic powder comprises: providing a source of hydrogenated NdFeB powder (101, 102, 103); feeding said powder into an inlet of a cyclone separator (104); separating the powder into an overflow enriched in Nd-rich grain boundary phase and an underflow enriched in NdxFeyBHz matrix phase particles (106); optionally feeding the underflow back into the inlet of the cyclone separator whereby to further enrich the underflow in the NdxFeyBHz matrix phase particles (108a); and collecting the underflow (108).

A method to separate rare earth material from a rare earth magnet. At least one embodiment comprises a method that heats a provided rare earth magnet to at least 600 C. whereby the rare earth magnet absorbs a dry gas. Separated rare earth materials are created. Magnetic rare earth materials are produced from the separated rare earth materials.

A rare earth magnet molding (1) of the present invention includes rare earth magnet particles (2), and an insulating phase (3) present among the rare earth magnet particles. Segregation regions (4) in which at least one element selected from the group consisting of Dy, Tb, Pr and Ho is segregated are distributed in the rare earth magnet particles (2). Accordingly, the rare earth magnet molding that has excellent resistance to heat in motor environments or the like while maintaining high magnetic characteristics (coercive force) is provided.

The present invention is directed to a method for preparing a permanent magnet, and more specifically, to a method for preparing a high-performance sintered NdFeB permanent magnet, in order to solve the problems of increased brittleness or high cost present in the permanent magnet prepared by the existing process. A method for preparing a sintered NdFeB permanent magnet includes the step of ingredient calculation and raw material preparation including calculating ingredients and preparing raw materials according to the ingredient formula of the resultantly sintered NdFeB permanent magnet, and dividing the raw materials into a rare earth FeB compound and rare earth metals.

Provided is a cleaning device for cleaning a magnet powder including: a flask provided to contain the magnet powder and a cleaning material used to clean the magnet powder; and a vacuum manifold provided to maintain the magnet powder and the cleaning material contained in the flask in an inert state during cleaning.

Provided is a method for cleaning a magnet powder including a loading operation for loading a magnet powder, a cleaning solution, and zeolite into a flask; a gas injecting operation for injecting an inert gas into the flask; and a vacuum drying operation for drying the magnet powder and the zeolite in a vacuum.

Provided is a method for manufacturing a magnet powder including: preparing a primary mixture by mixing neodymium (III) nitrate, boric acid, and iron (III) nitrate nonahydrate; preparing an oxide by heat-treating the primary mixture; removing a residual organic material of the oxide by heat-treating the oxide; preparing a hydrogen-reduced oxide by reacting the oxide, from which the residual organic material is removed, with hydrogen by heat treatment; preparing a secondary mixture by mixing the hydrogen-reduced oxide with calcium; obtaining a product by subjecting the secondary mixture to reduction-diffusion reaction by heat treatment; and obtaining Nd.sub.2Fe.sub.14B powder by pulverizing the product.

A method of increasing anisotropy of magnetic materials formed by a hydrogenation-disproportionation-desorption-recombination (HDDR) process is provided. The method includes subjecting a starting magnetic material to a hydrogenation-disproportionation (HD) step in the presence of a magnetic field to obtain intermediate materials. The strength of the applied magnetic field is between 0.25 T and 9 T, optionally less than or equal to 2 T. The HD step may be performed for a period of time between 10 and 60 minutes at a temperature of at least 600? C., optionally in the range of 600? C. to 900? C. Subsequently, the intermediate materials are subjected to a desorption-recombination (DR) step to obtain a magnetic powder. Application of the magnetic field during the hydrogenation-disproportionation step increases the magnetic anisotropy of the obtained magnetic powder. Magnetic powders obtained by the method and bonded magnets formed with the magnetic powders are also provided.

Provided are an auxiliary alloy casting piece, a high-remanence and high-coercive force NdFeB permanent magnet, and preparation methods thereof. The method for preparing the auxiliary alloy casting piece includes the following steps: providing an auxiliary alloy material including, by mass percentage, 40% to 45% of Pr, 1% to 2% of Co, 0.5% to 1% of Ga, 0.6% to 0.8% of B, 0.1% to 0.2% of V, 0.3% to 0.7% of Ti, and a balance of Fe; smelting the auxiliary alloy material to obtain a smelted material; and subjecting the smelted material to a quick-setting casting to obtain the auxiliary alloy casting piece; where the quick-setting casting includes a refining and a casting in sequence.