High-performance Ce-substituted (Nd0.7Ce0.3)-Fe-B hot-deformed magnets fabricated from amorphous melt-spun powders

We report a method to produce high-performance and cost-effective Ce-substituted Nd-Fe-B hot-deformed magnets with 30% Nd reduction. To suppress the formation of the Ce-dissolved REFe2 phase, which primarily limits [001] texture development and RE-rich grain boundary phase formation, amorphous melt-spun precursors were used to fabricate 30%-Ce-substituted hot-deformed magnets. By suppressing the formation of REFe2 phase from the precursors, the c-axis alignment of 2:14:1 platelets in the magnets due to grain boundary sliding and rotation improved, and the Nd/Ce-concentration of grain boundary phases in the magnets increased. As a result, both coercivity (Hcj) and remanence (4πMr) of the magnets noticeably increased to 15 kOe and 13 kG, respectively, in relation to those of the magnets fabricated from crystalline precursors containing an REFe2 phase (Hcj = 13.4 kOe, 4πMr = 12.1 kG). The magnetic performance of the 30%-Ce-substituted magnets developed in this work is sufficient to replace the N42M-graded commercial Ce-free magnets.