H01F1/0573

METHOD FOR PRODUCING A PERMANENT MAGNET FROM A MAGNETIC STARTING MATERIAL

The invention relates to a method of producing a permanent magnet from a powdered magnetic base material. The powdered magnetic base material is shaped, wherein a raw form is prepared. The raw form is sintered, wherein the permanent magnet is produced. In at least one step of the method, between particles of the powdered magnetic base material an electrical resistance layer having a lower electrical conductivity than the powdered magnetic base material is formed.

HIGH-STRENGTH R-T-B RARE EARTH PERMANENT MAGNET AND PREPARATION METHOD THEREOF
20230135049 · 2023-05-04 ·

The present invention discloses a high-strength R-T-B rare earth permanent magnet and a preparation method thereof. The magnet contains 0.3-1.5 wt. % of an element Zr, and a cast strip prepared through vacuum induction melting and melt spinning is treated at a high temperature to make the element Zr therein precipitate in a form of fibrous Zr compounds from R-rich phases, and the fibrous Zr compounds can be uniformly mixed with magnetic powder after hydrogen decrepitation and powder jet milling and mixing, and gradually grow into rod-like Zr compounds existing in the R-rich intergranular phases during the sintering of a green compact. By adjusting the content of the element Zr, sintering temperature and time and other process parameters, the morphology, size and distribution of Zr compounds can be effectively controlled, and the mechanical properties of the magnet can be improved by strengthening the R-rich intergranular phases without deteriorating the magnetic properties of the magnet.

NEODYMIUM-IRON-BORON MAGNET MATERIAL, RAW MATERIAL COMPOSITION, PREPARATION METHOD THEREFOR AND USE THEREOF
20220285059 · 2022-09-08 ·

Disclosed are a neodymium-iron-boron magnet material, a raw material composition and 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% of R′, wherein R′ is a rare earth element and includes Pr and Nd; and Pr≥17.15%; Cu≥0.35%; 0.9-1.2% of B; 64-69.2% of Fe. The percentages refer to the mass percentages relative to the total mass of the raw material composition of the neodymium-iron-boron magnet material. Without the addition of a heavy rare earth element, the neodymium-iron-boron magnet material can still have a high remanence and coercive force.

R-T-B PERMANENT MAGNET MATERIAL AND PREPARATION METHOD THEREFOR AND USE THEREOF
20220293311 · 2022-09-15 ·

An R-T-B permanent magnet material and a preparation method therefor and a use thereof. The R-T-B permanent magnet material comprises the following components: R′, which is between 29.5 wt. % and 33.0 wt. %, the R comprising R, Pr, and Nd, R being a rare earth element other than Pr and Nd, the Pr content being greater than or equal to 8.85 wt. %, the mass ratio of Nd to R being less than 0.5; N, which is greater than 0.05 wt. %, and less than or equal to 4.1 wt. %, the N being Ti, Zr, or Nb; B, which is between 0.90 wt. % and 1.2 wt. %; and Fe, which is between 62.0 wt. % and 68.0 wt. %. A sintered permanent magnet product having a high coercive force and a stable temperature coefficient is prepared by using a formulation having a high Pr content. The described formulation can maximally exert the advantage of Pr, and effectively reduce production costs.

R-T-B-BASED PERMANENT MAGNET MATERIAL, PREPARATION METHOD THEREFOR AND USE THEREOF
20220293309 · 2022-09-15 ·

Disclosed are an R-T-B-based permanent magnet material, a preparation method therefor and the use thereof. The R-T-B-based permanent magnet material I comprises the following components: 29.0-32.5% of R including RH, 0.30 to 0.50 wt. % of Cu, 0.05 to 0.20 wt. % of Ti, 0.85 to 1.05 wt. % of B, 0.1 to 0.3 wt. % of C, 66 to 68 wt. % of Fe, wherein R is a rare earth element and R at least includes Nd; and RH is a heavy rare earth element and RH at least includes Tb or Dy, A Cu—Ti—C grain boundary phase is formed in the R-T-B-based permanent magnet material I, and Hcj is significantly improved.

RARE EARTH PERMANENT MAGNET MATERIAL, RAW MATERIAL COMPOSITION,PREPARATION METHOD, APPLICATION, AND MOTOR
20220262550 · 2022-08-18 ·

A rare earth permanent magnet material, a raw material composition, a preparation method, an application, and a motor. The present rare earth permanent magnet material comprises the following ingredients in mass percentage: R 28.5-33.0 wt. %; RH>1.5 wt. %; Cu 0-0.08 wt. %, but not 0 wt. %; Co 0.5-2.0 wt. %; Ga 0.05-0.30 wt. %; B 0.95-1.05 wt. %; and the remainder being Fe and unavoidable impurities. The R-T-B system permanent magnet material has excellent properties and, under the condition that the content of heavy rare earth elements in the permanent magnetic material is 3.0-4.5 wt. %, Br≥12.78 kGs and Hcj≥29.55 kOe; under the condition that the content of heavy rare earth elements in the permanent magnet material is 1.5-2.5 wt. %, Br≥13.06 kGs and Hcj≥26.31 kOe.

SINTERED NEODYMIUM-IRON-BORON MAGNET AND PREPARATION METHOD THEREOF

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.

Magnet production

A process is provided for the production of rare earth magnets comprising the steps of exposing a rare earth alloy to hydrogen gas at an elevated temperature so as to effect hydrogenation and disproportionation of the alloy, mechanically processing the disproportionated alloy, and degassing the processed alloy so as to effect hydrogen desorption and recombination of the alloy. The process of the invention finds use in the production and shaping of rare earth magnets, and may be particularly applicable to the production of thin magnetic sheets.

RARE-EARTH PERMANENT MAGNET AND METHOD OF MANUFACTURING THE SAME

Disclosed are a rare-earth permanent magnet having improved magnetic properties and a method of manufacturing the same.

A method of manufacturing a rare-earth permanent magnet may include: preparing a mixed powder including i) a first alloy represented by R1.sub.aR2.sub.bB.sub.cM.sub.dFe.sub.bal and ii) a second alloy represented by R2.sub.bB.sub.cM.sub.dFe.sub.bal where R1 is one or two or more of La, Ce, and Y; R2 is a rare-earth element except for La, Ce, and Y; and M is a metal element; press-forming and sintering the prepared mixed powder in a magnetic field to prepare a sintered body; and performing a heat treatment based on diffusion temperature conditions of an R1 component and an R2 component contained in the prepared sintered body.

METHOD FOR PRODUCING RARE-EARTH MAGNET POWDER
20210308754 · 2021-10-07 · ·

A method for producing rare-earth magnet powder having high magnetic properties including a disproportionation step of causing hydrogen absorption and disproportionation reaction to a magnet raw material obtained by exposing a cast alloy containing a rare earth element (R), boron (B) and a transition metal (TM) to a hydrogen atmosphere having a temperature of 350 to 550 deg. C, and a recombination step of causing hydrogen desorption and recombination reaction to the magnet raw material after the disproportionation step.