Effect of Multiple Alloying Elements on Microstructure and Magnetic Properties of Nanocomposite Nd2Fe14B／α-Fe Magnets

Effect of multiple alloying elements (Ga, Nb, Zr, Hf and Pr) on microstructure and magnetic properties of nanocomposite Nd9-xPrxFe86.5-y-z-m-nGayNbzZrmHfnB4.5 (x=0, 2.25; y, z, m, n=0.5, 1.0) ribbons was investigated by a L16(215) orthogonal experiment. The results show that the addition of multiple alloying elements can effectively reduce the grain size of Nd2Fe14B and α-Fe phases and promote amorphous phase to occur at low wheel speed. No inhomogeneous growth of grains was found in annealed ribbons, but a large amount of additives would results in irregularity of Nd2Fe14B and α-Fe grains. On the other hand, addition of multiple alloying elements has complex effects on magnetic properties due to interactions between alloying elements. When the content of Nb is 0.5%, increasing the content of Pr and Ga and decreasing the content of Zr and Hf can improve the magnetic properties effectively. The optimum magnetic properties were obtained in Nd2.25Pr6.75Fe84.5Ga1.5Nb0.5B4.5 ribbons spun at 15 m*s-1 with Jr=1.053 T, iHc=530.9 kA*m-1,(BH)max＝124 kJ*m-3.