IP Library Granted Patent US 11,239,011
Granted Patent B2
US 11,239,011 · App. 16/826,380 · Granted Feb 1, 2022

Sintered R-T-B based magnet

Inventor: Futoshi Kuniyoshi (Minato-ku, JP)
Assignee: HITACHI METALS, LTD.
H01F1/0577C22C38/005H01F41/0293C22C2202/02
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Quick Facts
Patent No.
US 11,239,011
App. No.
16/826,380
Granted
Feb 1, 2022
Kind
B2
Abstract

A sintered R-T-B based magnet has remanence (B r ) of 1.47 T or greater and coercivity (H cJ ) of 1900 kA/m or greater and contains Tb at a content of 0.35 mass % or lower.

Claims (11)

1. A sintered R-T-B based magnet comprising:

a main phase which includes R 2 T 14 B compound particles;

a grain boundary phase which is at grain boundaries of the main phase;

a portion in which a concentration of Tb gradually decreases from a surface toward an interior of the magnet;

a portion in which a concentration of Pr gradually decreases from the surface toward the interior of the magnet;

a portion in which a concentration of Ga gradually decreases from the surface toward the interior of the magnet;

Tb at a content of 0.30 mass % or lower, wherein

the sintered R-T-B magnet:

has a remanence (B r ) of 1.47 T or greater and coercivity (H cJ ) of 1900 kA/m or greater,

includes RL (RL is at least one type of light rare-earth element and includes Nd and Pr), and satisfies 26.5 mass %≤[RL]−6[oxygen]≤28.8 mass %, where [RL] is the content (mass %) of RL and [oxygen] is the content (mass %) of oxygen, and

satisfies 0.07 mass %≤[oxygen]≤0.15 mass %.

Assignments (2)
CHANGE OF NAME Recorded Dec 27, 2023
From: HITACHI METALS, LTD.
To: PROTERIAL, LTD.
Reel/Frame 066130/0563 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 23, 2020
From: KUNIYOSHI, FUTOSHI
To: HITACHI METALS, LTD.
Reel/Frame 052204/0870 →
Priority Claims (2)
JP JP2019-056142 · Mar 25, 2019 · national
JP JP2019-176506 · Sep 27, 2019 · national
Continuity (1)
Related Publication 20200312492A1 · Oct 1, 2020