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.

Provided are a neodymium-iron-boron magnet material, raw material composition, preparation method, and application. The raw material composition of the neodymium-iron-boron magnet material comprises the following mass content components: R: 28-33%; R is a rare earth element, R comprises R1 and R2; R1 is a rare earth element added during smelting, and R1 comprises Nd and Dy; R2 is a rare earth element added during grain boundary diffusion, R2 comprises Tb, the content of R2 is 0.2%-1%; Co: <0.5%, but not 0; M: ≤0.4%, but not 0, and M is one or more of Bi, Sn, Zn, Ga, In, Au, and Pb; Cu: ≤0.15%, but not 0; B: 0.9-1.1%; Fe: 60-70%; the percentage is the mass percentage of the mass of each component to the total mass of the raw material composition. The neodymium-iron-boron magnet material has high remanence, coercivity, and good thermal stability.

Disclosed are a method for pulverizing a waste magnet and a waste magnet powder produced by the method. More particularly, disclosed is a method for efficiently producing a waste magnet powder having a small average particle size by pulverizing a raw material containing a hydrogen-occluded rare earth metal before dehydrogenation of the raw material.

An R-T-B series permanent magnet material, a raw material composition, a preparation method, and an application. The R-T-B series permanent magnet material comprises the following components: R: 29-31.0 wt. %, RH is greater than 1 wt. %, B: 0.905-0.945 wt. %, C: 0.04-0.15 wt. %, N: 0.1-0.4 wt. %, and Fe: 67-69 wt. %, wherein R comprises RL and RH, RL is a light rare earth element, RL comprises Nd, RH is a heavy rare earth element, a (RL.sub.1-yRH.sub.y).sub.2T.sub.17C.sub.x phase is present at the grain boundary of the R-T-B series permanent magnet material, x: 2-3, y: 0.15-0.35, and T must comprise Fe, and also comprises one or more among Co, Ti and N. The permanent magnet material retains relative high Br and Hcj under different heat treatment temperatures.

According to the present invention, a method for manufacturing a rare earth magnet that is capable of manufacturing a high-performance rare earth magnet with stable quality in large amount by the grain boundary diffusion method utilizing a film formed by the physical vapor phase deposition method is provided.

Disclosed is a segmented magnet which may adjust the application direction of a heavy rare earth element for grain boundary diffusion depending on the magnetization direction of the segmented magnet so as to simplify the manufacturing process of the segmented magnet while reducing eddy current loss, and a method for manufacturing the same. The method includes preparing a plurality of permanent magnet parent bodies having a constant magnetization direction, diffusing a diffusion material into the prepared permanent magnet parent bodies via a pair of planes thereof opposite each other and parallel to the magnetization direction along grain boundaries so as to form a pair of diffusing surfaces, preparing a permanent magnet assembly by stacking the permanent magnet parent bodies in a line such that the diffusing surfaces thereof face each other, and segmenting the permanent magnet assembly into a plurality of pieces along planes perpendicular to the magnetization direction.

A sintered magnet body (R.sub.aT.sup.1.sub.bM.sub.cB.sub.d) coated with a powder mixture of an intermetallic compound (R.sup.1.sub.iM.sup.1.sub.j, R.sup.1.sub.xT.sup.2.sub.yM.sup.1.sub.z, R.sup.1.sub.iM.sup.1.sub.jH.sub.k), alloy (M.sup.1.sub.dM.sup.2.sub.e) or metal (M.sup.1) powder and a rare earth (R.sup.2) oxide is diffusion treated. The R.sup.2 oxide is partially reduced during the diffusion treatment, so a significant amount of R.sup.2 can be introduced near interfaces of primary phase grains within the magnet through the passages in the form of grain boundaries. The coercive force is increased while minimizing a decline of remanence.

Disclosed are a neodymium-iron-boron magnet material, a raw material composition, a preparation method therefor and a use thereof. The raw material composition of the neodymium-iron-boron magnet material comprises the following components by mass percentage: 29.5-32.8% of R′, wherein R′ includes Pr and Nd, and Pr≥17.15%; Al≥0.5%; 0.90-1.2% of B; and 60-68% of Fe. The percentages are the mass percentages relative to the total mass of the raw material composition of the neodymium-iron-boron magnet material. Without adding a heavy rare earth element to the neodymium-iron-boron magnet material, the performance of the neodymium-iron-boron magnet material can still be significantly improved.

Disclosed are a stirring process and a stirring system for a neodymium-iron-boron powder and a process for manufacturing a neodymium-iron-boron magnetic steel. The stirring process for the neodymium-iron-boron powder mainly comprises the following aeration, feeding and stirring. Specifically, the aeration refers to filling a mixer with nitrogen and/or an inert gas, with the internal space of the mixer closed; the feeding refers to placing a neodymium-iron-boron powder to be stirred into the mixer and keeping the internal space of the mixer closed; and the stirring refers to introducing the mixer with a pulsed air stream, which is an intermittently jetted air stream formed by nitrogen and/or an inert gas, and by which the neodymium-iron-boron powder can be repeatedly blown up and down to mix and stir the neodymium-iron-boron powder.

Provided is a rare earth magnet alloy having a tetragonal R.sub.2Fe.sub.14B crystal structure, including: a main phase containing, as main constituent elements, at least one kind selected from the group consisting of: Nd; La; and Sm, Fe, and B; and a sub-phase containing, as main constituent elements, at least one kind selected from the group consisting of: Nd; La; and Sm, and O, wherein La substitutes for at least one of a Nd(f) site or a Nd(g) site, wherein Sm substitutes for at least one of a Nd(f) site or a Nd(g) site, wherein La segregates in the sub-phase, and wherein Sm is dispersed in the main phase and the sub-phase without segregation.