晶界扩散Dy/Tb烧结NdFeB研究进展

Progress in sintered NdFeB magnets with Dy/Tb grain boundary diffusion

由于汽车和电子应用领域对节能电动机的需求,在VCM、电动机、信号发生器、手机和MRI等领域中得到广泛应用的烧结钕铁硼在电动机市场应用会进一步扩展。剩磁和矫顽力等磁性能的提高有利于烧结磁体在电动机市场快速增长。通常,烧结磁体一些性能的改善总是以牺牲其他性能为代价。而晶界扩散Dy/Tb烧结磁体与传统的同类磁体相比较,其矫顽力和剩磁可同时得以改善,本文对晶界扩散Dy/Tb钕铁硼的一些研究成果进行了综述和总结。晶界扩散Dy/Tb过程中烧结磁体晶界的成份和微观组织的变化对烧结磁体磁性能改善至为重要。

Many new applications of Nd-Fe-B magnets, such as voice coil motor （VCM） in hard disc drive, motors, generators, mobile phone, MRI, ere, are expected to expand in future because of strong energy saving requirements from the automobile and electric appliances markets. Magnetic property improvement in residual （Br） and coercive force （Hcj） helps the rapid growth of the motor market. In many instances, an improvement of some characteristics of sintered magnet is achieved but only at the expense of other characteristics. It has been found that Dy/Tb grain boundary diffusion processed Nd-Fe-B sintered magnets have improvement in both the highest remanence and cocercivity among conventional rare-earth permanent mgnets, which have been introduced in this paper. The influence of Dy/Tb grain boundary diffusion on composition and microstructure of grain boundaries phase is a key point for magnetic property improvement of sintered magnet.