Recent progress of grain boundary diffusion process for hot-deformed Nd-Fe-B magnets

Grain boundary diffusion process (GBDP) was first proposed for sintered Nd-Fe-B magnets to achieve the high utilization efficiency of heavy rare earth elements. Recent success of fabricating high performance nanocomposite magnets by GBDP indicates that this method also exerts huge applicable potential on hot-deformed Nd-Fe-B magnets. In this review, the development and magnetic property enhancement mechanisms of different diffusion methods proposed on hot-deformed magnets were thoroughly elucidated. Moreover, the improve room for further property enhancement and the accompanying problems of GBDP on hot-deformed magnets are also discussed in this article.