A method for the preparation of an anisotropic sintered permanent magnet

• Main Authors: TAWARA, YOSHIO, OHASHI, KEN
• Format: Patent
• Language: English; French; German
• Published: 22.10.1986
• Edition: 4
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INDUCTANCES; MAGNETS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; TRANSFORMERS

In place of the static magnetic field used in the conventional powder metallurgical process in the step of the orientation of anisotropically magnetic particles during shaping by compression to give a green body prior to sintering, the magnetic field applied to the mass of magnetic particles is given pulse-wise and an impacting compressive force is applied to the thus oriented particles in the direction parallel to the magnetic field during the period in which a pulse of the pulse-wise magnetic field is sustained. This method ensures to obtain a much higher degree of particle orientation than in the conventional static-field method by virtue of the possibility of obtaining a much stronger magnetic field without problems otherwise unavoidable. The principle of the method is applicable also to the preparation of a cylindrical or annular permanent magnet magnetizable in a plurality of radial directions.