Star Group Ind. Co., Ltd

Hyundai Motor Company

Kia Motors Corporation

Koon Seung Kong

Dong Hwan Kim

Jae Hyuk Jang

Do Hoon Kim

Hyung Ju Lee

Jae Ryung Lee

Young Beom Kim

There is provided a method for manufacturing a rare earth sintered magnet to improve the high temperature demagnetization characteristic of the rare earth permanent magnet, by diffusing a heavy rare earth element to the grain boundary of a sintered magnet to improve the magnetic characteristics based on temperature.

Method for manufacturing rare earth permanent magnet

There is provided a method for manufacturing a rare earth sintered magnet having a stable magnetic performance, by uniformly distributing a heavy rear earth element to the surface of the magnet and the grain boundary inside of the magnet by using a mixture of a heavy rare earth compound or a heavy rare earth metal alloy and a rare earth magnet powder, to lower a decrease rate of the magnetic characteristics based on the temperature of the rare earth sintered magnet.

There is provided a method for manufacturing a rare earth sintered magnet by many times repetitively finely pulverizing a rare earth alloy on a jet mill by supplying high-pressure nitrogen gas to narrow grain size distribution to make an easy alignment in a magnetic field, and by micronizing crystal grains by using a hydrogenation-disproportionation-desorption-recombination (HDDR) process, to improve the coercivity and thermostability of the rare earth sintered magnet.

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 R1R2BMFeand ii) a second alloy represented by R2BMFewhere 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.

Rare-earth permanent magnet and method of manufacturing the same

A method for producing a heavy rare earth grain-boundary-diffused RE-Fe&#x2014;B-based rare earth magnet and a heavy rare earth grain-boundary-diffused RE-Fe&#x2014;B-based rare earth magnet produced thereby is disclosed. More particularly, a method for producing a heavy rare earth grain-boundary-diffused RE-Fe&#x2014;B-based rare earth sintered magnet having a reduced content of a heavy rare earth element is disclosed, in which a hydrogen compound of a heavy rare earth is mainly used as a diffusion material in the production of the grain-boundary-diffused magnet so that a product having uniform and stable quality can be produced. The coercive force of the magnet can be increased while minimizing the amount of heavy rare earth used in the production of the grain-boundary-diffused magnet, by solving the problem that the heavy rare earth is not uniformly diffused into the magnet, and a heavy rare earth grain-boundary-diffused RE-Fe&#x2014;B-based rare earth magnet produced thereby.

Method for producing heavy rare earth grain-boundary-diffused RE&#x2014;Fe&#x2014;B-based rare earth magnet and heavy rare earth grain-boundary-diffused RE&#x2014;Fe&#x2014;B-based rare earth magnet produced thereby

The present invention provides a method for manufacturing a rare-earth magnet, the method comprising the steps of preparing a rare-earth magnet raw material powder including R, Fe and B as composition components (R is one or more elements selected from the rare earth elements including Y and Sc); packing the raw material powder into a molding die, and compacting and molding the raw material powder while applying a magnetic field, wherein, in the compacting and molding step, compacting is performed biaxially, in the directions of X and Y axes, when the magnetic field is applied in the direction of Z axis.

Method for manufacturing rare earth magnet

Disclosed is a method of producing a rare earth permanent magnet including preparing a NdFeB sintered magnet, coating a surface of the NdFeB sintered magnet with a grain boundary diffusion material including R hydrate or R fluoride, and RMor M, to form a grain boundary diffusion coating layer, and diffusing the grain boundary diffusion material into a grain boundary of the NdFeB sintered magnet by heat treatment, wherein M is a metal having a melting point higher than a heat treatment temperature during the diffusion, R is a rare earth element, and a and b each represent atomic percentages which satisfy the following Equations (1) and (2):0.1&#x3c;&#x3c;99.9&#x2003;&#x2003;(1)=100&#x2003;&#x2003;(2).

Growing community of inventors

Daegu, South Korea

Koon Seung Kong