METHOD OF RECEIVING OF HARD MAGNETIC COMPOSITE MATERIAL WITH NANOCRYSTALLINE STRUCTURE Russian patent published in 2009 - IPC H01F1/10 B22F3/12 B82B3/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to powder metallurgy, particularly to receiving of constant powder-like magnets with nanocrystalline structure. It can be used at manufacturing of high-energy constant magnets on the basis of natural iron-containing powder material. Initial powder material, containing, wt %: α-Fe 25-50, Fe₂O₃ 30-75, FeO 0,2-2, attendant admixtures - the rest, it is treated in high-energy mill, to which there are loaded actuating mediums in the forms of steel balls. Treatment is implemented at value of energy-intensity, equal to 12-20 watt/g., during the time, required for transformation of initial powder material into intermediate powder material, containing, wt %: FeO 50-80, α-Fe 10-35, amorphous phase 10-30, attendant admixtures - the rest. Intermediate material is pressed at 300-600 MPa with receiving of compacted samples and it is implemented magnetothermal treatment of received samples in vacuum furnaces at residual pressure not less than 10^-1 mm of mercury at annealing temperature, equal to 200-400°C, during time not less than 1 h and at value of magnetising force from 3 kE up to 7 kE.

EFFECT: receiving of hard-magnetic composite material with nanocrystalline structure containing, wt %: Fe₃O₄ - 65-80%, α-Fe - 35-20%, attendant admixtures - the rest, with magnetic and crystalline texture with keeping of high magnetic properties.

9 cl, 1 tbl