A method of manufacturing a rare earth permanent magnet

文件类型：PDF文档
文件大小：155K
PROBLEM TO BE SOLVED : To suppress the increase of the content of oxygen after a finely pulverizing stage and to suppress deterioration in magnetic properties in a method for producing an R-T-B-based permanent magnet comprising a stage of contact with air. SOLUTION : Alloy powder for a permanent magnet having a nitrogen content of ≤300 ppm and an oxygen content of ≤6, 000 ppm is used, so that the R-T-B-based permanent magnet having stable magnetic properties can be obtained even if the time in contact with air in the state of fine powder varies. The alloy powder for the permanent magnet can be obtained by a finely pulverizing stage of performing air flow pulverizing in an inert gas atmosphere having an oxygen concentration of 500 to 4, 500 ppm. COPYRIGHT : (C)2005, JPO&NCIPI