| 摘要 |
An R-T-B based alloy powder which is composed of not less than 27.5 mass% and not more than 36.0 mass% of R (where R is at least one among the rare-earth elements and always includes either Nd or Pr), not less than 0.85 mass% and not more than 1.05 mass% of B (boron), not less than 0.1 mass% and not more than 2.5 mass% of element M (where M is at least one selected from the group consisting of Al, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn, Hf, Ta, W, Pb and Bi), and a balance T (where T is: Fe; or Fe and Co), and in which powder satisfying the condition L / d ‰¦ 5.39-1.07( a / b ) accounts for 20% or more, given a ratio a / b between a longer diameter a and a shorter diameter b and a ratio L / d between a circumferential length L and an equivalent circular diameter d (i.e., a diameter of a circle of an identical area) of contour shapes resulting from two-dimensional projection of particles. |
