ENHANCEMENT OF MATERIAL PROPERTIES BY MAGNETIC FIELD ASSISTED PHASE TRANSFORMATION

摘要

Using magnetic field assisted phase transformation, an enhancement of the exchange coupling and hard magnetic properties of melt-spun Nd_2Fe_(14)B/α-Fe-type nanocomposites was achieved by optimizing their nanostructure and morphology. Compared with the Nd_(2.4)Pr_(5.6)Dy_1Fe_(84)Mo_1B_6 sample annealed without a magnetic field, the magnetic annealing results in a noticeable improvement in the coercivity _iH_c, the remanence 4πM_r, and energy product (BH)_(max) for Nd_(2.4)Pr_(5.6)Dy_1Fe_(84)Mo_1B_6 alloys. (BH)_(max) at 50 K was enhanced by 43.7% after magnetic annealing in a 19 T field. The kink in the demagnetization curve disappeared and, additionally, a much better squareness of the demagnetization curves was observed in the magnetically annealed samples.