Patent ID: 8105446

Claim:
Alloy flakes for a rare earth sintered magnet, said alloy flakes having a composition consisting of 27.0 to 33.0 mass % of at least one element R selected from the group consisting of rare earth metal elements including yttrium, 0.94 to 1.30 mass % of boron, and the balance of at least one element M selected from the group consisting of transition metals, silicon, carbon, and mixtures thereof, with iron being essential, and an alloy structure comprising R-rich regions and dendrites of an R 2 Fe 14 B phase, wherein an average interval r between said R-rich regions is 1 to 10 μm, and an average size of crystal grains in the alloy structure is larger than (6r+2.74x−65) μm and not smaller than 40 μm, wherein r stands for an average interval between said R-rich regions, and x stands for a content of R in mass %.