Crystallization behavior of Nd–Fe–B-based alloys

Abstract Minor alloying additions to Nd–Fe–B significantly alter the crystallization kinetics of the alloy. The crystallization behavior of stoichiometric Nd 2 Fe 14 B displayed conventional behavior, with an Avrami exponent, n , close to 3. TiC additions stabilized the glassy phase and contributed to a more uniform crystallized grain structure. The time to complete crystallization was extended, implying a change in crystallization kinetics. The kinetic behavior and microstructural evolution implied growth-controlled crystallization. However, substitution additions to form a nine-component alloy displayed anomalous crystallization behavior (large n ). EDS results, which showed partitioning of Ti and C, interfacial enrichment of the rare-earth elements, and interfacial depletion of Fe, suggested that diffusion processes may be important in this system, while microstructural development suggested that the transformation was dominated by a rapidly changing nucleation rate.