Nissan Motor Company Limited

Osaka University

Shinichirou Fujikawa

Takashi Furuya

Kenichi Machida

Akihiko Ikeda

Masaya Arai

Yoshio Kawashita

Ryou Murakami

Hiroki Matsunae

Koichi Nakazawa

Masaru Uenohara

Seiji Kawai

Michihiro Sako

Genya Yamato

A method for manufacturing a sintered magnet includes molding a green compact formed by compacting a magnet powder by press-molding the magnet powder, the green compact forming an R&#x2014;Fe&#x2014;B based sintered magnet having Nd as the principal component and containing a rare earth element R, sintering the green compact by heating to a sintering temperature, so as to mold a sintered magnet, pressure molding the sintered magnet by heating to a temperature not exceeding the sintering temperature, so as to correct dimensions of the sintered magnet, and adjusting the texture of the sintered magnet by aging heat treatment using heated atmosphere produced when correcting the dimensions of the sintered magnet at a temperature not exceeding the temperature during the pressure molding.

Method for manufacturing sintered magnet

An improvement of coercive force of Nd&#x2014;Fe&#x2014;B base sintered magnet can be realized while suppressing a decrease in remanent magnetic flux density to the minimum using a method for modifying grain boundary which comprises heat-treating an Nd&#x2014;Fe&#x2014;B base magnet with a specific alloy disposed on its surface, the alloy having the following Formula 1:RAB&#x2003;&#x2003;(1)wherein R represents at least one rare earth element including Sc and Y, A represents Ca or Li, B represents an unavoidable impurity, and 2&#x2264;x&#x2264;99, 1&#x2264;y&#x3c;x, and 0&#x2264;z&#x3c;y.

Method for modifying grain boundary of Nd&#x2014;Fe&#x2014;B base magnet, and body with modified grain boundary treated by the method

A bond magnet molding is provided that contains coated magnetic particles having at least two layers of an oxide layer of 1-20 nm on a surface of magnetic particles and an organic layer of 1-100 nm on an outer side of the oxide layer. The bond magnet molding preferably includes a Zn alloy as a binder. The Zn alloy has a strain rate sensitivity exponent (m value) of not less than 0.3 and an elongation at break of not less than 50%. The magnet particles have a nitrogen compound containing Sm and Fe that are solidified using the binder at a temperature not higher than a molding temperature.

Magnet particles and magnet molding using same

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Kanagawa, Japan

Shinichirou Fujikawa