Patent ID: 8317937
Filing Date: 2012-11-27
Classification: C22C,H01F

Abstract:
1. A material alloy used to produce a sintered R-T-B-M magnet having a composition that comprises: 12 at % to 17 at % of R, which represents rare-earth elements that include both a light rare-earth element RL and a heavy rare-earth element RH and which includes either Nd or Pr as the light rare-earth element RL and at least one of Tb, Dy and Ho as the heavy rare-earth element RH; 5 at % to 8 at % of B, part of which is replaceable with C; 2 at % or less of an additive element M, which is at least one element 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 T (which is a transition metal that includes Fe as a major component and that possibly includes Co) and inevitable impurities as the balance, wherein a continuous region where the heavy rare-earth element RH has a high concentration is present at an interface between crystals of an R