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

Author(s)
Christian Huber, Hossein Sepehri-Amin, Michael Goertler, Martin Groenefeld, Iulian Teliban, Kazuhiro Hono, Dieter Suess
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. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Organisation(s)
Physics of Functional Materials
External organisation(s)
National Institute of Materials Science (NIMS), JOANNEUM RESEARCH Forschungsgesellschaft mbH, Magnetfabrik Bonn GmbH
Journal
Acta Materialia
Volume
172
Pages
66-71
No. of pages
6
ISSN
1359-6454
DOI
https://doi.org/10.1016/j.actamat.2019.04.037
Publication date
06-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/coercivity-enhancement-of-selective-laser-sintered-ndfeb-magnets-by-grain-boundary-infiltration(12f4a86c-3503-4dad-a01d-429e4b6b1264).html