Microstructural characteristics of Nd2Fe14B/α-Fe nanocomposite ribbons bearing Nb element

The effects of Nb on the microstructure and magnetic properties of (Nd0.9Dy0.1)9.5Fe79-xCo5NbxB6.5 (x = 0, 1) nanocomposite magnets were investigated. A fine and uniform microstructure was achieved for the ribbons annealed at 710°C for 4 min, enhancing the interaction coupling between grains and improving the magnetic properties. The results of three-dimensional atom probe (3DAP) indicated that Fe-Nb-B intergranular phase existed at the grain boundaries, suppressing the grain growth during the crystallization process. The coercivity was improved from 224 to 643 kA/m for the modification of the microstructure.