R−T−B−C BASED RARE EARTH MAGNETIC POWDER AND BONDED MAGNET

Title:

R−T−B−C BASED RARE EARTH MAGNETIC POWDER AND BONDED MAGNET

Document Type and Number:

WIPO Patent Application WO/2003/003386

Kind Code:

A1

Abstract:

A method for preparing a R−T−B−C based rare earth alloy magnetic material, which comprises a step of quenching a melt of a R−T−B−C based rare earth alloy, wherein R represents at least one of the rare earth elements including Y, T represents a mixture of transition metals containing iron as a main component, B is boron and C is carbon, to form a rapidly solidified alloy, and a heat treatment step of heating the rapidly solidified alloy to allow crystallization to proceed, wherein a first compound phase having a R₂Fe₁₄B type crystal structure and a second compound phase having a diffraction peak at a position corresponding to a lattice plane interval (d) of from 0.295 nm to 0.300 nm (approximately 2Ѳ = 30&ring ) are formed in the heat treatment step, and the intensity ratio of the above diffraction peak of the second compound phase to the diffraction peak ascribed to (410) plane of the R₂Fe₁₄B type crystal structure is 10 % or more&semi and a R−T−B−C based rare earth alloy magnetic material prepared by the method. The rare earth alloy magnetic material contains carbon (C) as an essential element and also has excellent magnetic characteristics and thus can be recycled with ease and at a low cost.

Inventors:

TOMIZAWA HIROYUKI (JP)
KANEKO YUJI (JP)

Application Number:

PCT/JP2001/005688

Publication Date:

January 09, 2003

Filing Date:

June 29, 2001

Export Citation:

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Assignee:

SUMITOMO SPEC METALS (JP)
TOMIZAWA HIROYUKI (JP)
KANEKO YUJI (JP)

International Classes:

B22F1/00; B22F9/10; B22F8/00; C22C33/02; C22C38/00; H01F1/04; H01F1/053; H01F1/057; H01F1/058; H01F1/06; H01F1/08; (IPC1-7): H01F1/04

Foreign References:

JPH0778706A	1995-03-20
JPH10324962A	1998-12-08
JP2001143916A	2001-05-25
JP2001118710A	2001-04-27
EP1085531A2	2001-03-21
EP1005050A2	2000-05-31

Other References: