Effect of Multiple Alloying Elements on Microstructure and Magnetic Properties of Nanocomposite Nd_2Fe_(14)B/α-Fe Magnets

摘要

Effect of multiple alloying elements (Ga, Nb, Zr, Hf and Pr) on microstructure and magnetic properties of nanocomposite Nd_(9-x)Pr_xFe_(86.5-y-z-m-n)Ga_yNb_zZr_mHf_nB_(4.5)(x = 0, 2.25; y, z, m, n =0.5, 1.0) ribbons was investigated by a L_(16)(2~(15) ) orthogonal experiment. The results show that the addition of multiple alloying elements can effectively reduce the grain size of Nd_2Fe_(14)B and α-Fe phases and promote amorphous phase to occur at low wheel speed. No inhomo-geneous growth of grains was found in annealed ribbons, but a large amount of additives would results in irregularity of Nd_2Fe_(14)B 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 Nd_(2.25)Pr_(6.75)Fe_(84.5)Ga_(1.5Nb_(0.5)B_(4.5) ribbons spun at 15 m·s~(-1) with J_r = 1 .053 T, _iH_c = 530.9 kA·m~(-1), (BH)_(max) = kJ·m~(-3).