Patent ID: 7217328

Claim:
A compound for a rare-earth bonded magnet, the compound comprising a rare-earth alloy powder and a binder, wherein the rare-earth alloy powder includes at least about 2 mass % of Ti-containing nanocomposite magnet powder particles, and the Ti-containing nanocomposite magnet powder particles have a composition represented by the general formula: (Fe 1-m T m ) 100-x-y-z Q x R y M z where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C and always includes B; R is at least one rare-earth element substantially excluding La and Ce; M is at least one metal element selected from the group consisting of Ti, Zr and Hf and always includes Ti; and the mole fractions x, y, z and m satisfy the inequalities of: 10 at %<x≦20 at %; 6 at %≦y<10 at %; 0.1 at %≦z≦12 at %; and 0≦m≦0.5, respectively, the Ti-containing nanocomposite magnet powder particles include at least two ferromagnetic crystalline phases, in which hard magnetic phases have an average crystal grain size of about 10 nm to about 200 nm, soft magnetic phases have an average crystal grain size of about 1 nm to about 100 nm, and the average crystal grain size of the soft magnetic phases is smaller than the average crystal grain size of the hard magnetic phases, the Ti-containing nanocomposite magnetic powder particles include an R 2 Fe 14 B compound phase at 60 volume % or more, and the soft magnetic phase of the Ti-containing nanocomposite magnetic powder particles includes an iron-based boride phase.