Preparation of Pr-Fe-Co-B-M (M=Nb, Zr) nanocomposite permanent magnets with enhanced coercivity by rapid solidification

摘要

Direct synthesis of NdFeB/Fe_3B based nanocomposite permanent magnets by rapid solidification of casting has received considerable attention. Chang group reported a series of ejection cast NdFeB rods with diameters of 0.5～1.5 mm. Most importantly, different from most previous BMG alloys, these magnets had much higher RE content (up to 9.5 at.%), which significantly improved the coercivity. In this work, using selected compositions and casting parameters, nanocrystalline Pr-Fe-Co-B-M (M=Nb, Zr) alloy rods with a diameter of 2 mm have been prepared by copper mold suction casting. The structure and magnetic properties of these rod magnets, together with ribbons samples with similar compositions, before and after heat treatment were investigated.