MANUFACTURE OF R-FE-B ANISOTROPIC COMPRESSION-MOLDED BONDED MAGNET

摘要

PURPOSE:To improve the magnetic property of the title magnet, such as the packing ratio, degree of magnetic orientation, etc., of magnetic powder by performing the first compression molding on a mixture of R-Fe-B anisotropic magnetic powder and a binder under a low pressure in the direction perpendicular to a magnetic field impressing direction, and then, the second compressionmolding on the mixture with a pressure lower than the first pressure in the direction parallel to the magnetic field impressing direction. CONSTITUTION:The first compression-molded body is formed by performing the first compression-molding on a mixture of R-Fe-B anisotropic magnetic powder prepared by pulverizing thin bands obtained by quenching an R-Fe-B (R: a rare earth element containing Y) liquid and a binder after hot upsetting under a low pressure in the direction perpendicular to a magnetic field impressing direction. Then the second compression-molding is performed on the mixture with a pressure lower than the pressure of the first compression-molding in the direction parallel to the magnetic field impressing direction. As a result, an R-Fe-B anisotropic compression-molded magnet with anisotropic magnetic powder which is high in degree of magnetic orientation and packing ratio can be obtained. The second compression- molding can be performed while the magnetic field is applied in the same direction as the magnetic field applied direction and it is preferable to set the pressure of the first compression- molding at 0-3 tons/cm2 (however, '0' is not contained).