摘要
Effects of addition of Co on the microstructure and magnetic properties of the series of (Nd, Pr)_ 10.5(Fe, Zr)_ 83.5-xCo_xB_6 alloys, which were prepared by over-quenching and post annealing method, were investigated. The free surface microstructures of crystallized ribbons were observed by means of Atom force microscopy (AFM). The significant improvement of remanence B_r and maximum energy product (BH)_m by Co addition is attributed to the increase of each phase magnetization and the exchange-coupling regions between the soft and hard magnetic phases. However, Co addition decreases the intrinsic coercivity (H_ ci), resulting from the grain coarsening and the (Nd,Pr)_2Co_ 14B phase, which has less anisotropy field (HA) at room temperature. The value of 2%(atom fraction) of Co addition is optimal. The bonded magnets of (Nd,Pr)_ 10.5(Fe,Zr)_ 81.5Co_2B_6 has the best combination of properties, which are B_r=0.662 T, H_ ci=616 kA·m -1 and (BH)_ max=74.0 kJ·m -3.
Effects of addition of Co on the microstructure and magnetic properties of the series of (Nd, Pr)_ 10.5(Fe, Zr)_ 83.5-xCo_xB_6 alloys, which were prepared by over-quenching and post annealing method, were investigated. The free surface microstructures of crystallized ribbons were observed by means of Atom force microscopy (AFM). The significant improvement of remanence B_r and maximum energy product (BH)_m by Co addition is attributed to the increase of each phase magnetization and the exchange-coupling regions between the soft and hard magnetic phases. However, Co addition decreases the intrinsic coercivity (H_ ci), resulting from the grain coarsening and the (Nd,Pr)_2Co_ 14B phase, which has less anisotropy field (HA) at room temperature. The value of 2%(atom fraction) of Co addition is optimal. The bonded magnets of (Nd,Pr)_ 10.5(Fe,Zr)_ 81.5Co_2B_6 has the best combination of properties, which are B_r=0.662 T, H_ ci=616 kA·m -1 and (BH)_ max=74.0 kJ·m -3.
基金
NatureScienceFoundationofSichuanProvince(2004A110)
