Microstructure and magnetic properties of sintered Nd–Fe–B magnets with Ce substitution for Nd by intergranular-alloy method

Abstract

Aiming at the comprehensive utilization of the rare-earth resources and the preparation of the high-performance low-cost Nd–Fe–B magnets, sintered magnets with different Ce substitution amounts of 17.2 wt%, 24.8 wt% and 31.8 wt% were prepared by intergranular-alloy method. The influence of substitution of Ce for Nd on their microstructure and magnetic properties in this work was detailedly investigated. The results indicated that the remanence (Br) and the maximum energy product ((BH)max) of the sintered magnets decreased monotonically with the increase in Ce substitution. However, the obvious enhancement of coercivity (Hcj) was also observed, which was mainly due to the improvement of microstructure and the smooth, continuous grain boundary (GB). It can be found that a reasonable Ce substitution of 24.8 wt% for the sintered magnets could promote the refinement of microstructure, leading to the realization of superior magnetic properties. It is expected that the investigations could be beneficial to offer a feasible method for preparing the high-performance low-cost Ce-doped magnets.