R-t-b based sintered magnet
AssigneeTDK Corporation
InventorsTetsuya HIDAKA, Takuma HAYAKAWA, Makoto IWASAKI, Ayato KAKOKI
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Abstract
An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.
Claims19
An R-T-B based sintered magnet comprising “R”, “T”, and “B”, wherein
- “R” represents a rare earth element,
- “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, and Co,
- “B” represents boron or boron and carbon,
- a content of “R” is 28.0 to 31.5 mass % with respect to 100 mass % of a total mass of the R-T-B based sintered magnet,
- a content of Cu is 0.04 to 0.50 mass % with respect to 100 mass % of a total mass of the R-T-B based sintered magnet,
- a content of Mn is 0.02 to 0.10 mass % with respect to 100 mass % of a total mass of the R-T-B based sintered magnet,
- a content of Al is 0.15 to 0.30 mass % with respect to 100 mass % of a total mass of the R-T-B based sintered magnet,
- a content of Co is 0.50 to 3.0 mass % with respect to 100 mass % of a total mass of the R-T-B based sintered magnet, and
- a content of “B” is 0.85 to 1.0 mass % with respect to 100 mass % of a total mass of the R-T-B based sintered magnet.
A method for manufacturing an R-T-B based sintered magnet, comprising the steps of:
- preparing a sintered body;
- and
- conducting a heat treatment for grain boundary diffusion after attaching a compound or alloy containing a heavy rare earth element on a surface of the sintered body, wherein
- “R” represents a rare earth element,
- “T” represents a metal element other than rare earth elements,
- “B” represents boron or boron and carbon, and
- the sintered body comprises at least Fe, Cu, Mn, Al, Co, Ga, and Zr as “T”.
Dependencies are inferred from the claim text.