Nd2Fe14B Permanent Polymeric Composite Magnets

Manufacture of polymeric composite magnets using isotropic NdFeB powder and different polymeric matrices; polyethylene glycol (PEG) as thermoplastic, epoxy as thermoset and styrene butadiene rubber (SBR) as elastomeric matrices have been studied in this work. Magnet powder was crushed mechanically and sorted in the particle sizes of 74-100, 2-10, and 1 microns. PEG Nano-powder was also prepared via solvent/non-solvent method. The effects of particle size of the magnetic powder, polymer content, type of polymeric matrices and processing conditions on the magnetic properties of the product, i.e. residual magnetic induction (Br), coercive field strength (Hc), maximum energy product (BH)max and density were investigated. NdFeB-PEG permanent composite magnet made of magnetic powders with a particle size of 74-100 μm and 5 php (the ratio of polymer loading per 100 g magnetic powder) of PEG nano-powder was found to have the best magnetic properties. The measured properties of this product were as follows: final density = 5.444 g/mL; Br= 3.82 kG, Hc = 8.415 and kOe; (BH)max= 14.454 MGOe.