Effect of Gallium Addition on Magnetic Properties of Nd_2Fe_(14)B-Based/α-Fe Nanocomposite Magnets

摘要

The influence of Ga addition on the crystallization behavior and the magnetic properties of nanocomposite Nd_2Fe_(14)B-based/α-Fe magnets was investigated. It was found that the addition of 0.2% did not change the crystallization temperature of amorphous alloy, but the magnetic properties were improved significantly because of the strong exchange coupling interaction between the hard and soft magnetic phases. The optimum magnetic properties with _iH_c = 600.3 kA·m~(-1), B_r = 0.75 T, and (BH)_(max) = 88.03 kJ·m~(-3) were obtained in bonded Nd_(9.5)(FeCoZr)_(83.8)Ga_(0.2)B_(6.5) magnet with 15 m·s~(-1) wheel speed and 670℃ annealing treatment. The apparent improvement of magnetic properties originates from the grain refinement calculated using the Scherrer formula from corresponding XRD patterns and the excellent rectangulari-ty of the demagnetization curve.