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arXiv · 1903.02233

Coercivity enhancement of selective laser sintered NdFeB magnets by grain boundary infiltration

Christian Huber·Hossein Sepehri-Amin·Michael Goertler·Martin Groenefeld·Iulian Teliban·Kazuhiro Hono·Dieter Suess
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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 sintered 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 formation of Nd-rich grain boundary phase, introducing Tb-rich shell at the surface of Nd2Fe14B grains, and maintaining the grain size in nano-scale are responsible for the large coercivity enhancement.

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Christian Huber, Hossein Sepehri-Amin, Michael Goertler, Martin Groenefeld, Iulian Teliban, Kazuhiro Hono, Dieter Suess. 2019-03-06. Coercivity enhancement of selective laser sintered NdFeB magnets by grain boundary infiltration. https://arxiv.org/abs/1903.02233

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