Rolling of ferromagnetic ferrite powder by use of synthetic rubber. Bainda yo gomu wo mochiita ihosei jisei funmatsu no atsuen kako

For the purpose of producing composite magnetic substances having flexibility and favorable orientation, it was attempted to form a composite material containing anisotropic magnetic powder by means of rolling process. Plate-type anisotropic Sr-ferrite (average particle size of 1.15[mu]m) for bond magnet was used as magnetic powder, and kneaded with Zn-22Al superplastic alloy powder and synthetic rubber in various mixing ratios Then, the kneaded and compacted material was rolled, and the relations between its properties and forming conditions such as draft, rolling temperature (50-120[degree]C), mixing ratio of magnetic powder, and addition of calcium stearate were investigated. Residual flux density (Br) and coercivity (iHc) were evaluated as magnetic properties. The optimum forming conditions were draft of 90% and temperature of about 80[degree]C during rolling. The Br value of the obtained composite material approximated to the theoretical value which is calculated from ferrite content per unit volume. It showed that orientation of ferromagnetic powder was accomplished almost completely. 7 refs., 10 figs., 2 tabs.