Crystallization behavior and magnetic properties of the low rare-earth content (Nd=6 at. %) Nd–Fe–Co–V–B nanocomposite magnet ribbons prepared by rapid quenching method.

The low rare-earth content α-Fe/Nd[SUB2]Fe[SUB14]B nanocomposite magnets having a high soft phase ratio) were fabricated by the rapid quenching method and evaluations were made of the crystallization behavior, microstructure, and magnetic properties in the annealing process. An investigation of the relationship between the roller surface velocity, V[SUBs], and magnetic properties showed that changes)in the crystal grain size of the α-Fe phase following annealing could be attributed to differences in the amorphous content of the as-melt-spun ribbons. As the amorphous content was increased, their crystal grain size tended to become finer and their magnetic properties tended to improve. However, it was observed that the optimum rapid quenching rate exists. The slight presence of clusters in as-melt-spun ribbons is favorable for obtaining good magnetic properties because the growth of a-Fe crystals is inhibited. The presumed reason for this inhibiting effect is that α-Fe growth occurs in a process in which clusters containing Nd expel this element. In the case of a completely amorphous state, large crystals grew easily, because they consisted of only Fe and Co in the initial stage. [ABSTRACT FROM AUTHOR]