Abstract
Fe69B20.2Nd4.2Nb3.3Y2.5Zr0.8 hard magnets in rods were produced by injection casting method. Magnetic properties, phase evolution and microstructure for Fe69B20.2Nd4.2Nb3.3Y2.5Zr0.8 magnets have been investigated and presented in as-cast and annealed states. The magnets possess soft magnetic characteristics in as-cast state, and hard magnetic characteristics after annealing. The Nb refines the grain sizes of α-Fe, Fe3B and Nd2Fe14B magnetic phases, while Y and Zr improve the glass forming ability. Good magnetic properties in Fe69B20.2Nd4.2Nb3.3Y2.5Zr0.8 magnets arise from the microstructure composed of magnetically exchange coupled nanocrystalline α-Fe, Fe3B and Nd2Fe14B phases. Optimal annealed magnets of 2mm diameter and 30mm length demonstrate the hard magnetic properties, i.e. intrinsic coercivity jHc of 496kA/m, remanence Br of 0.76T and maximum energy product (BH)max of 72.0kJ/m3.
► Fe69B20.2Nd4.2Nb3.3Y2.5Zr0.8 magnets are produced by injection casting. ► Magnetic properties depend on the intrinsic properties of the phases. ► Microstructure is composed of α-Fe, Fe3B Nd2Fe14B nano-grains. ► Magnets demonstrate jHc of 496kA/m, Br of 0.76T and (BH)max of 72kJ/m3.