Study on magnetization reversal behavior for annealed Nd2Fe14B/α-Fe nancomposite alloys

Effect of thermal annealing on the magnetization reversal behavior of α-Fe/Nd2Fe14B alloys was investigated. A drastic increase of the remanence Mr from 0.67 up to 0.87 T and remanence ratio Mr/Ms from 0.66 up to 0.76, respectively, was observed in the α-Fe/Nd2Fe14B alloys annealed at 610 °C as compared with the as-quenched sample. Whereas the further annealing at 680 °C resulted in a strong increase of the corecivity Hc as high as 491 kA/m but a slight decrease in Mr. The analysis result of the magnetization reversal behavior showed that the maximum value of the integrated recoil loop area about 1.58 kJ/m3 was obtained in the α-Fe/Nd2Fe14B alloys at the annealing temperature of 610 °C, significantly lower than other annealed samples. This indicated a significant advantage for the application of this material as permanent magnets in electrical machines and generators due to a low energy loss.

Recoil loops of the initial magnetization and demagnetization curves for the Nd2Fe14B/α-Fe samples annealed at various temperatures (a) As-quenched; (b) 610 °C; (c) 680 °C; (d) 800 °CFigure optionsDownload as PowerPoint slide