RARE-EARTH PERMANENT MAGNET, PROCESS FOR PREPARING THE SAME AND PERMANENT MAGNET ROTATING MACHINE

文件类型：PDF文档
文件大小：388K
PURPOSE : An R-Fe-B based rare earth permanent magnet having a low eddy current and a high coercive force suitably for permanent magnet rotary machines, wherein R is at least one element selected from rare earth elements including Y and Sc, a method for making the magnet, and a permanent magnet rotary machine using the magnet are provided. CONSTITUTION : In a method for making a rare earth permanent magnet from a sintered magnet body having a R^1-Fe-B based composition, wherein R^1 is at least one element selected from rare earth elements including Y and Sc, the method comprises : forming a plurality of slits in at least one surface of the corresponding magnet body; and heat treating the corresponding magnet body and the powder to a sintering temperature of the corresponding magnet body or less in vacuum or in an inert gas in the state that a powder comprising at least one compound selected from an oxide of R^2, a fluoride of R^3, and an oxyfluoride of R^4 is present on a surface of the corresponding magnet body, wherein each R^2, R^3, and R^4 is at least one element selected from rare earth elements including Y and Sc. © KIPO 2007