Patent ID: 10515747

Abstract:
The invention provides an R—Fe—B sintered magnet consisting essentially of 12-17 at % of Nd, Pr and R, 0.1-3 at % of M1, 0.05-0.5 at % of M2, 4.8+2*m to 5.9+2*m at % of B, and the balance of Fe, containing R2(Fe,(Co))14B intermetallic compound as a main phase, and having a core/shell structure that the main phase is covered with a grain boundary phases. The sintered magnet has an average grain size of less than 6 μm, a crystal orientation of more than 98%, and a degree of magnetization of more than 96%, and exhibits a coercivity of at least 10 kOe despite a low or nil content of Dy, Tb, and Ho.