Magnetic Properties and Corrosion Characteristics of Nd-(Fe,Co,Ni)-B Pseudo-Ternary System

Melt-spun ribbons and sintered materials with the composition Nd15(Fe1-x-yCoxNiy).77B8 were investigated with respect to the saturation magnetization, coercivity, Curie temperature and corrosion characteristics. It was found that simultaneous substitution of Co and Ni atoms for Fe atoms enhances the intrinsic coercivity of sintered magnets in the composition range 0.2¿x¿0.4 and 0.0¿y¿0.2, and also improves the corrosion resistance. A further addition of Ti atoms to the system increases the coercivity and makes the demagnetization curve rectangular. For example, the (BH)max and intrinsic coercivity in Nd15(Fe0.585Co0.30Ni0.10 Ti0.015)77B8 are as high as 33.8 MGOe and 10.4 kOe respectively.