Controlling new die mechanisms for magnetic characteristics of super-largeferrite cores

If a super-large core with a groove is molded with an axial molding press r eplacing the conventional die set, uneven density distribution occurs in th e core because the molding pressure considerably converges on the groove of the core. Since this induces the residual stress in the groove to be relea sed during the sintering process, it is difficult with the conventional die set to obtain the necessary dimensional precision and satisfactory magneti c characteristics. we devised a die mechanism capable of solving these prob lems through the reduction of converging pressure on the groove. This new d ie mechanism improves the moldability and magnetic characteristics of super -large ferrite cores through the uniform distribution of density and magnet ic characteristics.