SINTERED MAGNET PRODUCTION METHOD

摘要

The present invention addresses the problem of providing a sintered magnet production method in which the cracking of the sintered magnets hardly occurs. It is a method having a pulverizing process in which a lump of alloy of a material for a sintered magnet is pulverized by a method including a hydrogen pulverization method, a filling process in which a cavity is filled with alloy powder obtained by the pulverizing process, an orienting process in which the alloy powder is magnetically oriented by applying a magnetic field to the alloy powder, and a sintering process in which the alloy powder is sintered by heating it according to a predetermined temperature history. In the sintering process, the alloy powder is heated in an inert-gas atmosphere at a higher pressure than atmospheric pressure until the temperature reaches a predetermined pressurization maintenance temperature which is higher than a hydrogen desorption temperature as well as equal to or lower than the sintering temperature. By performing the heating treatment in such a pressurized inert gas, hydrogen-gas molecules remaining in the alloy powder are prevented from suddenly desorbing from the alloy powder, so that the cracking of the sintered magnets hardly occurs.