Method for manufacturing alloy for RTB-based rare earth sintered magnet and method for manufacturing RTB-based rare earth sintered magnet

摘要

The alloy for R-T-B-based rare earth sintered magnet of the invention is characterized by comprising rare earth element R, transition metals containing Fe as the main component, metal elements M containing at least one element selected from Al, Ga and Cu,and B and inevitable impurities; containing 13 to 16 atom % R, 4.5 to 6.2 atom% B, and 0.1to 2.4 atom% M, and the rest is T; the ratio of Dy in the total rare earth element is 0 to 65 atom%, satisfying following (expression 1), and comprising a main phase containing R2Fe14B and more alloy grain boundary phase containing R compared with the main phase; the interval of the alloy grain boundary phase is from 1[mu]m to 3[mu]m. 0.30=B/TRE=0.37 (expression 1).