R-T-B-BASED ALLOY POWDER AND METHOD FOR PRODUCING SAME, AND R-T-B-BASED SINTERED MAGNET AND METHOD FOR PRODUCING SAME

Title:

R-T-B-BASED ALLOY POWDER AND METHOD FOR PRODUCING SAME, AND R-T-B-BASED SINTERED MAGNET AND METHOD FOR PRODUCING SAME

Document Type and Number:

WIPO Patent Application WO/2015/146888

Kind Code:

A1

Abstract:

A R-T-B-based alloy powder which comprises 27.5 to 36.0% by mass inclusive of R (wherein R comprises at least one rare earth element and R essentially contains Nd and/or Pr), 0.85 to 1.05% by mass inclusive of B (boron), 0.1 to 2.5% by mass inclusive of element M (wherein M represents at least one element selected from the group consisting of Al, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn, Hf, Ta, W, Pb and Bi), and a remainder made up by T (wherein T represents Fe or both of Fe and Co), and which contains a powder at a percent ratio of 20% or more, wherein the powder satisfies the requirement represented by the formula: L/d ≤ 5.39 - 1.07(a/b) wherein a/b represents the ratio of the longer diameter (a) to the shorter diameter (b) in a shape produced by two-dimensionally projecting each particle of the powder and L/d represents the ratio of the perimeter (L) of each particle of the powder to the equivalent circle diameter (d) of the particle (the diameter of a circle having the same area as that of the particle).

Inventors:

ISHII RINTARO

Application Number:

PCT/JP2015/058686

Publication Date:

October 01, 2015

Filing Date:

March 23, 2015

Export Citation:

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Assignee:

HITACHI METALS LTD (JP)

International Classes:

H01F1/057; B22F1/00; B22F1/05; B22F1/06; B22F1/14; B22F3/00; B22F3/02; B22F9/04; C22C38/00; H01F1/06; H01F1/08; H01F41/02

Domestic Patent References:

WO2012002531A1

2012-01-05

Foreign References:

JPS634001A	1988-01-09
JPH0774012A	1995-03-17
JPH09143514A	1997-06-03
JP2003049204A	2003-02-21
JP2005042156A	2005-02-17
JPH05135930A	1993-06-01
JPH06340903A	1994-12-13

Other References: