METHOD FOR PREPARING R-Fe-B BASED SINTERED MAGNET

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PROBLEM TO BE SOLVED : To provide a method for preparing a R-Fe-B based sintered magnet, by means of which processing cost of Dy is greatly reduced, the process is simplified, and the coercive force of a magnet after heat treatment can be greatly improved. SOLUTION : The method for preparing a R-Fe-B based sintered magnet comprises : firstly utilizing a conventional method to prepare a R-Fe-B based sintered magnet 3, and cleaning the sintered magnet through steps such as oil removing, acid-washing and water deionization; bespreading metal Dy 5 at the bottom of a bottle 2, and then filling the inside of the bottle with zirconia, silica or alumina powder 4 regardless of shape; inserting the sintered magnet 3 into powder in a direction perpendicular to a magnetization direction or placing a metal Dy plate, high-melting-point powder particles, the sintered magnet and the high-melting-point powder particles in this order inside the bottle in a layered mode; and placing the bottle inside a sintering furnace without contacting the bottom of the magnet with the Dy particles in the bottom of the bottle and without contacting adjacent magnets to each other, and performing heat treatment at 750-1000°C in a vacuum or argon gas protective atmosphere and enabling Dy to enter the inside of the sintered magnet along a grain boundary through diffusion. COPYRIGHT : (C)2015, JPO&INPIT