Melt-spun hard magnetic three-phase nanocrystalline Nd5Fe78.5B16.5 alloy

The aim of the present work was to prepare a three-phase nanocomposite containing high saturation {alpha}-Fe and Fe{sub 3}B soft phases and the Nd{sub 2}Fe{sub 14}B hard magnetic phase. The requirements for the microstructure of an exchange coupled material are a very fine and homogeneous grain size distribution and substantial absence of any intergranular phase. Since the crystallization of amorphous alloy is a multistage process, coarsening of the phase crystallizing in the first stage may occur till completion of the crystallization process, leading to deterioration in coercivity. The effect of annealing treatment on the intrinsic coercivity was therefore determined. Results of these investigations are reported in this paper.