Preparation and characterization of polymeric composite permanent magnet Nd2Fe14B

Preparation of polymeric composite magnets using isotropic NdFeB powder and polymeric materials (epoxy resin and latex rubber) have been investigated in this work. Isotropic powder NdFeB was crushed mechanically by hand mortar and sieved until passing 400 mesh. Epoxy Resin / latex rubber with the isotropic powder NdFeB were manually mixed for 20 minutes to achieve a good (homogeneous) mixture. Amount of polymeric materials were 5, 10, 15, and 20 % wt. from the mass of magnetic powder NdFeB. The mixtures were moulded in cylindrical die with a diameter of 10 mm by cold pressing under a force of three tons, then all samples were cured at temperature 100oC for two hours by using drying oven. The cured samples were measured bulk density by archimedes method, and all samples were magnetized by impulse magnetizer. The surface magnetic field strength (FS) was measure by Gaussmeter, other magnetic properties (remanence Br, coercivity Hc and energy product BHmax) were measured by permeagraph. The measured properties for all samples are as follows : the optimum value of bulk density are 5.21 g/cm3 for samples with 5 % wt. epoxy resin and 5.03 g/cm3 for samples with 10 % wt. latex rubber. The sample with 5 % wt. epoxy resin has FS=2400 Gauss, Br=0.558 T, Hc=6.77 kOe, and BHmax=7.28 MGOe; also the sample with 10 % wt. latex rubber has FS=1750 Gauss, Br=0.402 T, Hc=5.14 kOe, and BHmax=4.38 MGOe.