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

Abstract 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 Ce2Fe14B phase lead to the low coercivity and thermal stability of this magnet. In this study, low-melting-point Pr68Cu32 powders were introduced into nanostructured MMP magnet through intergranular addition to further improve its coercivity and thermal stability. When only 2 wt% Pr68Cu32 was added, the intrinsic coercivity Hcj and thermal stability were significantly improved with a slight reduction in the remanence Br and the maximum energy product (BH)max. The microstructure evolution of MMP magnet with adding Pr68Cu32 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.