Rheology Of Bonded Magnet Feedstocks And Their Applications

Although the injection molding magnets have been reported to possess all-around outstanding service properties, they have also been reported to be difficult processability because of their poor flowability. The poor flowability of magnetic feedstock, especially for rare earth powders, limits their uses in numerous potential applications so that impedes magnet injection molding technology to achieve industrialization. In fact, bonded magnetic melt is a solidification suspension and its flowability is a critical factor for the successful utilization of injection molding technology in manufacturing bonded magnets. The study on the rheological behaviors of bonded magnets for injection molding is of important scientific and practical significance. Consequently, the rheology of bonded magnet feedstock is theoretical description of evaluating and improving the processing ability of bonded magnetic materials.The work of this study mainly involves three segments: the testing technology, the rheology of bonded magnet feedstock and the rheology applying. The molding method of bonded magnets is governed by its rheological behavior of the feedstock melts. The viscosity of feedstock melts decides the processing conditions and the geometry shapes of bonded magnet and accordingly determines the mechanic properties, magnetic properties and thermal properties of bonded magnets. The rheological properties of magnetic feedstock are strongly affected by the internal structure, the powder concentration, the types of binder, the morphological features...