Patent 7507302 was granted and assigned to Hitachi on March, 2009 by the United States Patent and Trademark Office.
A rare-earth alloy powder is obtained by rapidly cooling a melt of an alloy by an atomization process. The alloy has a composition represented by (Fe1-mTm)100-x-y-zQxRyTizMn, where T is at least one of Co and Ni, Q is at least one of B and C, R is at least one of the rare-earth metal elements and yttrium, and M is at least one of Nb, Zr, Mo, Ta and Hf. The mole fractions x, y, z, m and n satisfy 10 at %<x≦25 at %, 6 at %≦y<10 at %, 0.1 at %≦z≦12 at %, 0≦m≦0.5, and 0 at %≦n≦10 at %, respectively. By adding Ti to the alloy, the nucleation and growth of α-Fe during the rapid quenching process can be minimized.