METHOD OF MANUFACTURING MAGNETS BASED ON RARE METAL/IRON/BORON ALLOYS Russian patent published in 1998 - IPC

FIELD: magnet manufacture. SUBSTANCE: specified- composition alloy is smelted under inert gas atmosphere and ingots obtained are disintegrated in several steps. They are first crushed into 3-5-cm lumps, which are then crushed into particles with size no higher than 5 mm, these particles being further ground into fraction less than 0.7 mm and then, in ethyl or isopropyl alcohol medium, to form alcohol suspension of powder with grain size 1-3 mcm. Resultant powder is compressed in magnetic field, dried in vacuum, sintered under high vacuum at residual pressure no higher than 10^-5 mm Hg, heated with two retention times, and thermally treated in vacuum at 500 to 900 C. Half-finished products obtained are cooled, machine-worked, subjected to additional heat treatment, and covered by anticorrosive layer. EFFECT: stabilized formation of high hysteresis properties, increased magnetic characteristics and coercive force value. 16 cl, 1 dwg