Transfer of knowledge to industry
Département des Technologies des NanoMatériaux (LITEN)
Laboratoire de Formulation des Matériaux
01-11-2020
SL-DRT-20-0329
Energy efficiency for smart buildings, electrical mobility and industrial processes (.pdf)
Due to their remarkable magnetic properties, permanent magnets made of NdFeB alloys are an important part of the Energy Transition, with several applications in Energy (wind turbines) and in Transport (electric vehicle) sectors, for example. NdFeB magnets are usually produced by powder compression and sintering, and complex shapes are obtained through expensive machining operations. The powder injection moulding (PIM) process allows the direct production of parts with complex geometries through the conventional plastics processing technics, and is a way to reduce both machining operations and waste materials. Therefore, PIM is currently under consideration for the manufacturing of permanent NdFeB magnets with high density and magnetic performances and complex geometries. Nevertheless, the use of organic polymer binders for injection moulding (i), and the post-injection chemical and physical debinding steps (ii) during the PIM procedure, can be responsible of potential organic (i.e. carbon and/or oxygen) contaminations of the NdFeB powder, and consequently, of a significant degradation of magnetic properties of the magnets. Each of these contributions needs to be in-depth studied, for optimizing the magnetic properties of injection-moulded permanent NdFeB magnets. In particular, the understanding of the physicochemical interactions between polymer binders (and/or their degradation products) with the NdFeB powders, should lead to the development of feedstocks compatible with the injection moulding of low-contaminated permanent magnets.
