Preparation of Sintered (Ce1−x Ndx)30FebalCu0.1B1 Magnets by Blending Powder Method

Magnets with nominal compositions of (Nd1-x Cex)30 Febal Cu0.1 B1 (x = 0, 0.15, 0.3 and 0.4, mass %) have been fabricated by blending powder method. The remanence (Br), intrinsic coercivity (Hc) and maximum energy product (BH)max of the RE2Fe14B type magnets deteriorated when Nd was replaced by Ce. The chemical composition and crystal structure of magnet were investigated systemically. Backscattered electron (BSE) and energy dispersive spectroscopy (EDS) results revealed that Ce-rich and Ce-lean matrix grains coexisted in the magnets. The magnetic coupling mechanism among the double hard magnetic phases was discussed. Low melting point RE-Cu phase was in favor of the formation of uniform continuous grain boundary. Transmission electron microscopy (TEM) investigation showed the presence of fcc (Nd, Ce)Ox phase in the grain boundary. When the Ce content was 15% of the total amounts of all the rare earth, the maximum energy product of the sintered magnet was 359.8 kJ/m3.