MANUFACTURE OF W PHASE TYPE HEXAGONAL FERRITE MAGNET OF LEAD SYSTEM

摘要

PURPOSE:To prevent a part of ferrite particles comprising W phase type hexagonal metallic oxides from performing the phase transfer to M phase type hexagonal metallic oxides, even when burning them after molding them in a magnetic field, by making the powder of PbO exist within a predetermined range when molding the powder of the W phase type hexagonal metallic oxides in the magnetic field. CONSTITUTION:PbO, ZnO, alpha-Fe2O3 and Al2O3, obtained by burning in the air, are so blended that the final composition of a ferrite magnet is 0.1PbO.0.2 ZnO.xFe2O3 when blending three components and is (0.1PbO.0.2ZnO.0.7Fe2 O3)100-y.(Al2O3)y when blending four components, (x is 6-9 and y is 0.1-2.0 in the equations), and are reduced to powder coarsely. This powder or the molded material by pressing this powder is burned and reduced to powder finely. At this time, PbO is added, and the fine powder of PbO is made to exist by 2-8weight% for the above-mentioned metallic oxides. After the obtained mixture is press molded in a magnetic filed, burned again at 1000-1250 deg.C in the air to obtain the ferrite magnet product.