Invention Grant
- Patent Title: Method for preparing rare earth permanent magnet material
- Patent Title (中): 稀土永磁材料的制备方法
-
Application No.: US11916498Application Date: 2007-03-28
-
Publication No.: US08420010B2Publication Date: 2013-04-16
- Inventor: Hajime Nakamura , Takehisa Minowa , Koichi Hirota
- Applicant: Hajime Nakamura , Takehisa Minowa , Koichi Hirota
- Applicant Address: JP Tokyo
- Assignee: Shin-Etsu Chemical Co., Ltd.
- Current Assignee: Shin-Etsu Chemical Co., Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Westerman, Hattori, Daniels & Adrian, LLP
- Priority: JP2006-112358 20060414
- International Application: PCT/JP2007/056586 WO 20070328
- International Announcement: WO2007/119551 WO 20071025
- Main IPC: B22F7/00
- IPC: B22F7/00

Abstract:
A method for preparing a rare earth permanent magnet material is characterized by comprising the steps of disposing a powder mixture on a surface of a sintered magnet body of R1—Fe—B composition wherein R1 is at least one element selected from rare earth elements inclusive of Sc and Y, the powder mixture comprising a powder containing at least 0.5% by weight of M which is at least one element selected from Al, Cu, and Zn and having an average particle size equal to or less than 300 μm and a powder containing at least 30% by weight of a fluoride of R2 which is at least one element selected from rare earth elements inclusive of Sc and Y and having an average particle size equal to or less than 100 μm, and heat treating the magnet body having the powder disposed on its surface at a temperature equal to or below the sintering temperature of the magnet body in vacuum or in an inert gas, for causing at least one of M and R2 in the powder mixture to be absorbed in the magnet body. The invention provides an R—Fe—B sintered magnet with high performance and a minimized amount of Tb or Dy used.
Public/Granted literature
- US20090226339A1 METHOD FOR PREPARING RARE EARTH PERMANENT MAGNET MATERIAL Public/Granted day:2009-09-10
Information query