快淬速度对纳米晶复合Nd8.5Fe77.7Nb2Co5Ga0.6B6.2粘结永磁体温度系数的影响

Effect of Melt-Spun Speeds on the Temperature Coefficients of Nanocomposite Nd8.5Fe77.7Nb2Co5Ga0.6B6.2 Bonded Magnet

摘要:

采用熔体快淬法及真空退火工艺制备了不同淬速的Nd8.5Fe77.7Nb2Co5Ga0.6B6.2粘结磁体，研究了不同淬速下磁体的磁性能及温度系数。结果表明，适当的快淬速度有利于合金退火后的晶粒细化，有效地改善了退火后软、硬磁相间的交换耦合作用。快淬速度对磁体的温度系数有显著的影响，矫顽力温度系数β随着淬速的增加而逐渐降低；随着淬速的增加，剩磁温度系数α先降低后升高，这可能与合金中软、硬磁相间的交换耦合作用的变化有密切的关系。

Abstract:

Nanocomposite Nd8.5Fe77.7Nb2Co5Ga0.6B6.2 bonded magnets were prepared by melt-spun and vacuum annealing processes. The dependence on the melt-spun speed of magnetic properties and temperature coefficients of the magnets was investigated. The results show that a proper melt-spun speed is beneficial to the grain refinement and the exchange coupling effect between the Nd2Fe14B and α-Fe phases of the alloys annealed is greatly improved. It is also shown that the temperature coefficients are significantly influenced by the melt-spun speed. With the increase of the melt-spun speed, the temperature coefficient β of coercivity is continuously decreased. The temperature coefficient α of remanence is decreased first and then increased with the increase of the melt-spun speed. It might be closely related to the exchange coupling effect between the Nd2Fe14B and α-Fe phases.