Phase and microstructure formation of strip-cast Ce–Fe–B alloys for multi-phases RE-Fe-B magnets.

The starting alloy has a strong influence on the processing and the magnetic properties of the sintered magnets. Aiming at the preparation of the high-performance low-cost (Nd, Ce)–Fe–B magnets, the phase constitution and microstructure of Ce–Fe–B alloy are systematically investigated in this work. The results showed that Ce 2 Fe 14 B phase coexists with CeFe 2 phase in the Ce–Fe–B alloy. A fairly high proportion of 2:14:1 phase (～93.1%) and column crystals structure which is similar to that of Nd-Fe-B alloy could be obtained by regulating the composition of Ce–Fe–B alloy. Owing to the structure optimization of Ce–Fe–B alloy, the sintered magnet which possessed a microstructure of fine grains together with smooth and continuous grain boundaries could maintain the superior magnetic properties of B r = 13.1 kGs, H cj = 7.79 kOe and (BH) max = 40.49 MGOe by the mixture of (Pr, Nd) 12.75 Fe 80.25 M 1.0 B 6.0 and Ce 17 Fe bal M 2.0 B 6.0 (M = Al, Cu, Ga, Nb in at.%). This work thus provides useful guideline for the preparation of Ce-doped hard magnets. • A fairly high proportion of 2:14:1 phase (～93.1%) and column crystals structure could be obtained in Ce 17 alloy. • The sintered magnets could obtain excellent microstructure due to the structure optimization of Ce–Fe–B alloy. • The (BH) max of 40.49 MGOe was obtained with 25 wt% Ce substitution for Pr–Nd. [ABSTRACT FROM AUTHOR]