Coercivity and thermal stability enhancement of NdFeB magnet by grain boundary diffusion Tb80Al20 alloys

Grain boundary diffusion of Tb and Al elements can improve the coercivity and optimize grain boundary of NdFeB magnets. In this paper, we investigated magnetic property and microstructure evolution of sintered NdFeB magnets by grain boundary diffusion Tb80Al20 alloys. The coercivity and thermal stability of the magnets were effectively improved. Microstructural analysis confirmed the formation of Tb-rich shells and continuous grain boundary, contributing to coercivity enhancement of magnet. The element distribution and diffusion mechanism of the magnets have been disused. This work may shed light on developing low heavy rare earth sintered NdFeB magnets.