LAUSR

Abstract Laser powder bed fusion is a well-established additive manufacturing method that can be used for the production of net-shaped Nd Fe B magnets. However, low coercivity has been one of the drawbacks in the laser powder bed fusion processed Nd Fe B magnets. In this work, we have demonstrated that the grain boundary diffusion process using low-melting Nd Cu, Nd Al Ni Cu, and Nd Tb Cu alloys to the selective laser sintered NdFeB magnets can results in a substantial enhancement of coercivity from 0.65 T to 1.5 T. Detailed microstructure investigations clarified that the formation of Nd-rich grain boundary phase, the introduction of Tb-rich shell at the surface of Nd2Fe14B grains, and maintaining the grain size in nano-scale are responsible for the large coercivity enhancement.