Organic Contamination During The PIM Process Of High Performance NdFeB Magnets: Mechanims And Solutions

Authors:

Thomas Bioud (Université Grenoble Alpes CEA, France),
Maëlig Ollivier (Mines de Saint-Etienne, France),
Sorana Luca (Université Grenoble Alpes CEA, France),
Sébastien Rolère (Université Grenoble Alpes CEA, France)

Abstract:

NdFeB permanents magnets are key components for green transition technologies that require high energy|volume ratio. The conventional powder metallurgy process (alloying, powdering, compression and sintering) allow obtaining high magnetic performances however it does not allow the manufacturing of complex shapes and machining produces critical and expensive material waste.The Powder Injection Molding (PIM) process, involving the manufacturing of a feedstock that can be shaped using the conventional injection molding equipment, would solve these issues. Nevertheless, the use of organic binders for injection moulding, and the post-injection debinding steps during the PIM procedure, are sources of carbon and oxygen contaminations that reduce the magnetic properties. In this work, we investigated the organic contamination mechanism in magnets produced by PIM using polyolefin-based feedstocks. The control of the debinding parameters combined with specific feedstock and particle coating engineering steps, allowed us to produce magnets with excellent magnetic properties.

DOI:

https://doi.org/10.59499/WP225372001