RAW MATERIAL FOR PERMANENT MAGNETS AND PRODUCTION METHOD OF THE SAME

摘要

A raw material for samarium.iron.boron-permanent magnets superior in magnetic properties is provided together with the production method. The material for the permanent magnets comprises an acicular iron powder being prepared by reducing acicular FeOOH (goethite) crystal with hydrogen and having diffused layer of samarium and boron on the surface. The raw material is produced by mixing acicular iron powder obtained by hydrogen reduction of acicular FeOOH crystal with powder of a samarium.cobalt alloy having a melting point lower than 700.degree.C and powder of boron or powder of a ferro-boron alloy; heating the mixed powder under a hydrogen-nitrogen atmosphere at a temperature between the melting point of the samarium.cobalt alloy and 1200.degree.C to form coated and diffused layer with the samarium and boron on the surface of the acicular iron powder; and pulverizing the product thus obtained.