| 摘要 |
PURPOSE: To obtain a bonded magnet which has a prescribed heat resisting temperature or above by a method wherein a magnet material is of nano composite texture where a hard magnetic phase and a soft magnetic phase which meet certain requirements are smaller than a specific value in average grain diameter, a specific amount or more of hard magnetic material powder smaller than a specific value in diameter is contained, and a molding operation is carried out using thermoplastic resin whose melting point is higher than a certain value as binder. CONSTITUTION: The composition formula of a hard magnetic phase of Nd2 Fe14 B structure and a soft magnetic phase of body-centered cubic iron, iron boride is represented by a formula, Rx (Fe1-u )Cou )100-x-y-z By Cr2 (R is one or more elements selected out of Pr, Nd, and Dy), wherein x (atom %), y (atom %), and z (atom %), and U are so set as to satisfy following formulas, 4.5<=x<=6.0, 15<=y<=20, 3<=z<=7, and 0.04<=u<=0.10. A magnet material is of nano composite texture where both a hard magnetic phase and a soft magnetic phase are set smaller than 50nm in average grain diameter, and 50% or more by volume of hard magnetic material powder smaller than 300μm in diameter is contained, and a molding operation is carried out using thermoplastic resin whose fusing point is higher than a temperature of 250 deg.C as binder. By this setup, an injection-molded resin bonded magnet with heat resisting temperatures of 200 deg.C or above can be obtained. |
