Invention Application
- Patent Title: RARE-EARTH SINTERED MAGNET
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Application No.: US16465402Application Date: 2017-11-30
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Publication No.: US20200005973A1Publication Date: 2020-01-02
- Inventor: Takurou IWASA , Ryuji HASHIMOTO , Masashi ITO
- Applicant: TDK CORPORATION
- Applicant Address: JP Tokyo
- Assignee: TDK CORPORATION
- Current Assignee: TDK CORPORATION
- Current Assignee Address: JP Tokyo
- Priority: JP2016-232112 20161130; JP2017-054942 20170321
- International Application: PCT/JP2017/043075 WO 20171130
- Main IPC: H01F1/055
- IPC: H01F1/055 ; H01F1/053 ; C22C38/00 ; C22C38/10 ; C22C33/02

Abstract:
A rare-earth sintered magnet contains main phase crystal grains having an Nd5Fe17-type crystal structure, includes R and T (where R represents one or more rare-earth elements that essentially include Sm and T represents Fe or one or more transition metal elements that essentially include Fe and Co), and wherein the compositional ratio of R is 20-40 at % and the remaining portion is substantially T; the remaining portion other than R is substantially only T or only T and C; and when the main phase crystal grains' average grain size in one cross-sectional surface of the rare-earth sintered magnet is defined as Dv, while grain size of individual main phase crystal grains is defined as Di, Dv is at least 1.0 μm, and the main phase crystal grains' area ratio that satisfy 0.7Dv≤Di≤2.0Dv is at least 80% with respect to the area of a cross-sectional surface of the rare-earth sintered magnet.
Public/Granted literature
- US11081265B2 Rare-earth sintered magnet Public/Granted day:2021-08-03
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