Process for producing magnetic materials
AssigneeSumitomo Special Metals Co., Ltd.
InventorsHitoshi Yamamoto, Masato Sagawa, Setsuo Fujimura, Yutaka Matsuura
Life of this patent
Estimating the term…
Abstract
Permanent magnetic materials of the Fe-B-R type are produced by: preparing an metallic powder having a mean particle size of 0.3-80 microns and a composition of, by atomic percent, 8-30% R (rare earth elements), 2-28% B, and the balance Fe, compacting, sintering at a temperature of 900-1200 degrees C., and aging at a temperature ranging from 350 degrees C. to the temperature for sintering. Co and additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) may be present.
Claims38
A process of producing a permanent magnet of the Fe-B-R type comprising:
- providing a sintered body having a composition consisting essentially of, by atomic percent, 12-24% R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and at least 50% of R consists of Nd and/or Pr, 4-24% B, and at least 52% Fe, and
- heat-treating the sintered body at a temperature ranging from 350 degrees C. to the sintering temperature in a non-oxidizing atmosphere for at least 5 minutes to increase the intrinsic coercivity of the sintered body.
Dependencies are inferred from the claim text.