PROCESS OF MANUFACTURE OF R-Fe-B PERMANENT MAGNETS Russian patent published in 1998 - IPC

FIELD: metallurgy. SUBSTANCE: in agreement with proposed process there are used finely ground powders produced by method of comminution of ingot or by method of Ca thermal reduction or by method of squeezing out of ingot from mould. Alloys are subjected to coarse comminution by grinding or by absorption of H₂ and decomposition and later are ground finely mechanically or in vortex mill with production of fine powder of R-Fe-B with average size of particles between 1,0-10 μм.. Then these powders are compacted in mould with compaction density of 1.4- 3.5 g/cu.cm and pulsating magnetic field having intensity bigger than 10.0 kOe is applied to mould with repeated inversion of magnetization vector. Finally cold isostatic compaction in static magnetic field is carried out. Produced magnets display excellent compaction characteristics, high degree of orientation of magnetization vector of each crystalline grain and total sum A+B, where A-(BH)_max and B-iHc(koe), that is greater than 59.5. EFFECT: increased efficiency of process. 20 cl, 4 tbl