PURPOSE: To obtain the rare-earth magnet, having a wide corrugated area of surface magnetic density and a high peak value, on which a high torque can be generated when it is used for a stepping motor and the like by a method wherein the rare-earth magnet, consisting of R-Fe-B in fundamental composition, is oriented in ultraanisotropy in a direct current magnetic field and it is pressure-molded using a pressing machine.
CONSTITUTION: A metal mold ring 8, consisting of a non-magnetic metal is fixed to the inner surface of a magnetic yoke 1 in order to give strength as a metal mold, and space 7 is formed with the lower core 4. Ultraanisotropic magnetic field is charged by a DC power source separately provided on the conducting wire 11 which is connected to a coil 9, and magnetic force is generat ed as shown by a magnetic line of force 10. The magnetic powder of the compo sition of (Ce0.2, Pr0.2, Nd0.5, Dy0.1)16, Fe66, CO10B8 is molded, and a ring-shaped ultraanisotropic molded body is obtained using said metal mold and a molding device. A ring-shaped ultraanisotropic magnet is formed by sintering said molded body, by performing an aging treatment and by conducting a grinding process, and a rotor magnet is formed by adhering the synthetic resin disc, which is lighter than a metal material, to the inner circumference as a spacer 12.
ISHIBASHI TOSHIYUKI
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