METHOD OF MANUFACTURING COPPERRSUBSTITUTED RARE EARTH COBALT PERMANENT MAGNET

摘要

PURPOSE:To reduce the characteristic deterioration of a copper-substituted rare earth cobalt permanent magnet and improve the productivity thereof by sintering powder pressure-molded in magnetic field at relatively low temperature at first step to thereby density it to form a preliminary sintered magnet and again sintering it at higher temperature than the first step at a second step. CONSTITUTION:After copper-substituted rare earth metal cobalt is pulverized to powder having predetermined mean grain size, the powder is pressure-molded in predetermined magnetic field. The powder is sintered on the same day as the pressure-molding day at a first step so that the sintering specific weight rho(g/cm3) is 7.0=rho=8.0 to thus form a preliminary sintered magnet. The sintered magnet is again sintered at higher temperature than the first step for predetermined time at a second step on the later day, and quenched, thereby manufacturing a permanent magnet having less magnetic characteristic deterioration.