The study on grain-boundary microstructure of sintered (Ce, Nd)-Fe-B magnets

The Nd-Fe-B magnets have attracted continuous interests in both technological and scientific fields because of their superior magnetic properties. However, the applications of the magnets have been hindered, especially, in price-sensitive areas by their relatively high cost. For the Nd-Fe-B magnets, neodymium nearly accounted for 90 % of the cost of raw materials. The price of Ce is only one tenth of the price of Nd. It is very attractive to reduce the cost by replacing Nd with more abundant and more inexpensive rare-earth elements of Ce, or mischmetal, despites of the fact that the magnetic anisotropy field, the saturation magnetization, and the Curie temperature of the Ce
₂
Fe
₁₄
B compound are much 1ower than those of the Nd
₂
Fe
₁₄
B. In the past several years, with the lasted developments in the preparation technologies of sintered Nd-Fe-B magnets, it has become feasible with a large proportion of Ce over 50 wt.% substituted for Nd in sintered (Ce, Nd)-Fe-B magnets (called as “Ce-Fe-B magnets”) [1]-[4].