METHOD FOR PRODUCING RARE EARTH PERMANENT MAGNETS, AND RARE EARTH PERMANENT MAGNETS

WIPO Patent Application WO/2011/145674

A1

R-T-B permanent magnetic powder is manufactured by the HDDR process, said magnetic powder having an average crystal grain size of 0.1 μm to 1 μm and an aspect ratio (major axis/minor axis) for the crystal grains of not more than 2 (Step A). R is a rare earth element containing at least 95 at% Nd or Pr with respect to total R. T is a transition metal element in which Fe or a portion of Fe has been substituted with Co and/or Ni, and which contains at least 50 at% Fe. Meanwhile, an R'-Cu alloy powder is prepared, said alloy powder comprising R' and Cu, and containing between 2 at% and 50 at% Cu (Step B). R' is a rare earth element containing at least 90 at% Nd and/or Pr with respect to total R', and not containing Dy and Tb. After mixing the R-T-B permanent magnetic powder with the R'-Cu alloy powder (Step C), the mixed powder is treated with heat at a temperature of 500°C to 900°C in an inert atmosphere or a vacuum (Step D).

JPS61231710	METHOD FOR ASSEMBLING TRANSFORMER CORE
JP3267133	ALLOY FOR RARE EARTH MAGNET, ITS PRODUCTION AND PRODUCTION OF PERMANENT MAGNET
JP3521284	MAGNETIC FIELD ORIENTED DIE

HONO KAZUHIRO (JP)
OHKUBO TADAKATSU (JP)
SEPEHRI AMIN HOSSEIN (JP)
NOZAWA NORIYUKI (JP)
NISHIUCHI TAKESHI (JP)
HIROSAWA SATOSHI (JP)

PCT/JP2011/061488

November 24, 2011

May 19, 2011

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NAT INST FOR MATERIALS SCIENCE (JP)
HITACHI METALS LTD (JP)
HONO KAZUHIRO (JP)
OHKUBO TADAKATSU (JP)
SEPEHRI AMIN HOSSEIN (JP)
NOZAWA NORIYUKI (JP)
NISHIUCHI TAKESHI (JP)
HIROSAWA SATOSHI (JP)

H01F41/02; B22F1/00; B22F3/14; C21D6/00; C22C38/00; H01F1/053; H01F1/06

WO2011070847A1	2011-06-16
WO2004064085A1	2004-07-29

JP2011061038A	2011-03-24
JP2000096102A	2000-04-04

OKUDA SEIJI (JP)
Seiji Okuda (JP)

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