R-Fe-B production of sintered-type permanent magnet

文件类型：PDF文档
文件大小：108K
PROBLEM TO BE SOLVED : To obtain an R-Fe-B based sintered permanent magnet excellent in corrosion resistance and magnetic characteristics by controlling the quantity of N in the sintered body of R-Fe-B based sintered permanent magnet. SOLUTION : In the method for pulverizing rough powder of R-Fe-B based material, molding and sintering the pulverized powder to produce an R-Fe-B based sintered permanent magnet (R represents one or more than one kind of rare earth element including Y), the rough powder of R-Fe-B based material is loaded into a pulverizer and Ar gas is substituted for the gas in the pulverizer such that the concentration of oxygen in Ar gas is substantially 0%. Subsequently, N2 gas is introduced and the concentration of N2 gas in Ar gas is conditioned in the range of 0.0001-0.5wt.%. The rough powder is pulverized in Ar gas containing N2 gas and the pulverized powder is collected directly into a solvent under Ar gas atmosphere to produce a slurry. The slurry is subjected to wet molding in magnetic field and the molding is subjected to desolation in a vacuum furnace before being sintered to produce an R-Fe-B based sintered permanent magnet.