Enhancement of magnetic properties of Fe3B/Nd2Fe14B magnet by the addition of Co

The addition of Co was found to enhance the magnetic properties of Fe3B/Nd2Fe14B nanocomposite magnets by evaluating Nd4Fe77.5xCox(HfGa)(y)B-18.5(0 less than or equal to x less than or equal to 5, 0 less than or equal to y less than or equal to 0.5). The enhancements were resulted from the fact that the Co addition retarded the crystallization of alpha-Fe and Fe3B and accelerated that of Nd2Fe14B. The decreased interval between the crystallization temperature of Fe3B and Nd2Fe14B enabled the grain growth of each phase to Be uniform during post annealing of the melt spun ribbons. The addition of Co. from 3 to 5 wt.% increased the coercivity(iH(c)) from 3.27 to 3.54 kOe with the enhanced remanence(4 pi M-r,) around 11.54 kG. By the optimized processing for the nanocomposite magnets of Nd4Fe71.5Co5Hf0.5Ga0.5B18.5 ribbons span at 26 m/sec and magnetization annealing at 680 degrees C for 10 min, the magnetic properties of B-r = 11.54 kG, H-i(c) = 3.54 kOe and (B.H)(max),= 14.35 MGOe were obtained from volume production line.