Significant changes in crystallization kinetics of Nd2Fe14B/α- Fe nanocomposites induced by Nb addition

The effects of Nb addition on the crystallization kinetics, microstructure and magnetic properties of melt-spun Nd2Fe14B/α-Fe nanocomposite magnets have been studied. The analysis of crystallization kinetics for the alloys indicates that the growth of crystallites in the Nb-doped alloy needs more activation energy than that in the Nb-free alloy. This crystallization behaviour contributes to the formation of a finer and more homogeneous microstructure in the Nb-doped alloy than in the Nb-free alloy. And the Nb addition makes the grains more equiaxed shape. The intrinsic coercivity and the maximum energy product increase from 600 kA/m, 105 kJ/m3 for Nd10Fe84B6 alloy to 750 kA/m, 120 kJ/m3 for Nd10Fe83Nb1B6 alloy, respectively.