METHOD FOR PRODUCING MAGNETICALLY HARD NANOCRYSTAL-STRUCTURE COMPOSITE MATERIAL Russian patent published in 2003 - IPC

FIELD: production of nanocrystal-structure powder permanent magnets. SUBSTANCE: proposed method for producing high-energy permanent magnets based on natural iron-containing powder material includes treatment of source iron-containing material in high-energy mill charged with crushed source iron-containing material and working bodies made in the form of steel balls, production of intermediate iron-containing material, and its heat treatment in furnaces. Used as source iron- containing material is natural iron-containing powder material having following phase composition, mas.%: Fe₂O₃, 93.00-99.3; FeO, 0.20- 2.00; SiO₂, 0.20-2.00; satellite impurities, the balance. Said operations result in production of magnetically hard composite material with nanocrystal structure of following phase composition: Fe₃O₄, α-Fe, FeO, SiO₂, and satellite impurities. EFFECT: enhanced magnetic properties of magnetically hard nanocrystal-structure composite material. 6 cl, 3 tbl