To provide a method for producing magnetic powder provided with good weatherability by uniformly and completely coating the surface of fine powder of a rare-earth iron based alloy and intermetallic compound magnetic material with a metal, alloy or compound having good weatherability, and manufacture a high-performance bonded magnet having good weatherability by using the surface-coated magnetic material powder as the material.
The surface of fine powder of a superior rare-earth iron based alloy and intermetallic compound as Sm2Fe17NX, uniformly dispersed in an organic solvent such as hexane, is uniformly and completely coated with a metal, alloy or compound generated by decomposition and reduction of a metal salt, a metal complex and an organic metal complex which are soluble to the organic solvent, thus producing magnetic material powder having good weatherability. Moreover, as necessary, the dispersion and heating in an organic solvent such as silicone oil improve the proceeding of reaction or the contactability between the magnetic material fine particles and the coating layer, thus providing a magnetic material powder having more superior weatherability. Using the surface-coated fine powder thus obtained as a material, high-performance bonded magnet having good weatherability at, for example, a point of a small demagnetization factor is manufactured.
MACHIDA KENICHI
NOGUCHI KENJI
NISHIMURA MASASHI
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