Influence of chemical composition non-homogeneity and texture on magnetic properties of (Nd, Dy, Tb)-(Fe,Ti)-B sintered magnets

A study was made into the role of dysprosium and terbium in formation of magnetic properties of sintered magnets bared on the alloy (Nd, Dy, Tb)15.7Fe75.5T1.3B7.5 as well as the influence of heat treatment conditions on coercive force and magnetization. Magnetic alloys were produced by induction melting with subsequent comminution, pressing and sintering. Microscopical examination and magnetic measurements showed that for an increase of coercive force in the alloy studied it is necessary to have maximal Tb and Dy concentrations in a main magnetically hard phase, especially in the vicinity of grain boundaries with nonmagnetic structural constituents. 8 refs., 2 figs., 2 tabs