Metal Injection Moulding of NdFeB Based on Recycled Powders

Philipp Imgrund, Oxana Weber, Thomas Schlauf, Karsten Pischang, Lydia Pickering, Allan Walton, Joamin Gonzalez-Gutierrez, Christian Kukla, Carlo Burkhardt

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


Over the last ten years several groups have been carrying out research into metal injection moulding (MIM) of neodymium-iron-boron (NdFeB) powders to produce isotropic or anisotropic rare earth magnets with higher complexity than in the conventional press and sintering approaches. However, difficult processability due to the high affinity of the powder to oxygen and carbon pickup remains problematic in terms of obtaining sufficient remanence and coercivity. In this paper, a new approach to MIM of NdFeB magnets is presented. It is based on the use of powder obtained from recycling of used rare earth magnets by the hydrogen decrepitation (HD) process. Different types of binder systems have been used for producing mouldable MIM feedstock. Influence of debinding and sintering conditions on interstitial contents and magnetic properties of sintered MIM parts are presented and discussed. Magnets with a remanence of 570 mT, a coercivity of 970 kA/m and an energy product of 57 kJ/m³ could be produced without additional heat treatment.
Original languageEnglish
Title of host publicationWorld PM2016 Congress & Exhibition
EditorsFrank Petzoldt
Place of PublicationHamburg, Germany
PublisherEuropean Powder Metallurgy Association
Number of pages7
Publication statusPublished - 9 Oct 2016
EventPowder Metallurgy World Congress and Exhibition - Congress Centrum Hamburg, Hamburg, Germany
Duration: 9 Oct 201613 Oct 2016


ConferencePowder Metallurgy World Congress and Exhibition
Abbreviated titleWorld PM 2016
Internet address


  • metal injection molding
  • magnets
  • Rare earths recycling
  • sintering

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