RARE EARTH SINTERED MAGNET AND MANUFACTURING METHOD FOR THE SAME

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PROBLEM TO BE SOLVED : To provide a rare earth sintered magnet which is low in impurity density and has less carbon density difference in the magnet, and a manufacturing method for the same. SOLUTION : A manufacturing method for a rare earth sintered magnet has : a melting step for obtaining material alloy; a pulverization step for preparing alloy fine powders; a molding step for obtaining a mold of the alloy fine powders; and a sintering step for sintering the mold. The pulverization step includes a coarse pulverization step and a fine pulverization step that include hydrogen storage processing, and includes a lubricant addition step before or after the coarse pulverization step. The sintering step includes an atmosphere heat treatment step and a vacuum heat treatment step. At the atmosphere heat treatment step, temperature is raised to decomposition temperature of lubricant or higher and to sintering temperature or lower to be held for a prescribed time, and temperature raising and the prescribed temperature holding are performed in 10 kPa to 100 kPa inert gas atmosphere. SELECTED DRAWING : None COPYRIGHT : (C)2022, JPO&INPIT