Preparation and Performance of Nano-crystalline （Nd, Ce）-Fe-B/（Nd, R）-Fe-B （R=Pr, La） Hot-pressed Magnets

Based on the dual-alloy technology, isotropic nanocrystalline (Nd, Ce) -Fe-B/(Nd, R)-Fe-B (R = Pr, La ) hot-pressed magnets with different proportions were prepared by spark plasma sintering, and the magnetic properties and microstructure of the hot-pressed magnets were investigated. The results show that the remanence and coercivity are improved with the addition of (Pr, Nd)-Fe-B alloy. BSE images(results) shows that the agglomerated block rare earth-rich phase gradually disappears, and the grain boundary phase becomes more uniform and thin, thereby increasing the coercivity. In addition, the increase of the proportion of (Pr, Nd)-Fe-B main phase also effectively improves the magnetic properties of hot-pressed magnets. When the addition amount is 60 %, the magnetic properties of J_r=8.58 ×0.1 (T), H_cj=12.65 ×79.6 (kA/m), (BH)_max=15.79 ×7.96 (kJ/m³) were obtained.