Magnetic properties, thermal stability, and microstructure of spark plasma sintered multi-main-phase Nd-Ce-Fe-B magnet with PrCu addition.

Nanostructured multi-main-phase (MMP) Nd-Ce-Fe-B magnet produced by melt-spinning powders has great potential for achieving high performance. However, the inferior intrinsic properties of the Ce 2 Fe 14 B phase lead to the low coercivity and thermal stability of this magnet. In this study, low-melting-point Pr 68 Cu 32 powders were introduced into nanostructured MMP magnet through intergranular addition to further improve its coercivity and thermal stability. When only 2 wt% Pr 68 Cu 32 was added, the intrinsic coercivity H cj and thermal stability were significantly improved with a slight reduction in the remanence B r and the maximum energy product (BH) max. The microstructure evolution of MMP magnet with adding Pr 68 Cu 32 was revealed by microstructural and compositional characterization and thermodynamic calculation, and a schematic model was proposed. Furthermore, mechanisms underlying changes in magnetic properties were systematically analyzed by combining micromagnetic simulation. ● Grain boundary modification is adopted for fabricating high-performance nanostructured MMP Nd-Ce-Fe-B magnet. ● H cj and thermal stability are significantly improved with a slight reduction in B r and (BH) max. ● Microstructure and microchemistry evolution are investigated and a corresponding model is proposed. ● Mechanisms underlying changes in magnetic properties are systematically analyzed. [ABSTRACT FROM AUTHOR]