MANUFACTURING METHOD FOR ANISORTOPIC SINTERED MAGNET AND MANUFACTURING EQUIPMENT THEREFOR

• Main Author: NOMURA TADAO
• Format: Patent
• Language: English
• Published: 16.03.2001
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; INDUCTANCES; MAGNETS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS

PROBLEM TO BE SOLVED: To mass-produce an anisotropic sintered magnet of a high magnet characteristic by a method wherein a magnetic field pressed Nb-Fe-B based compact is sintered in energization by use of a pulse current without deforming under pressure. SOLUTION: In a manufacturing method of an anisotropic sintered magnet, a magnetic field and a press molding have been beforehand applied to fine powders of a magnet alloy, which are a compact 2 by aligning an axis of easy magnetization. Next, an upper electrode 1 of an energization sintering device is installed on an upper face of the compact 2, and a lower electrode 3 thereof is installed on a lower face thereof. A position of the upper electrode 1 is not fixed, and is installed movably in accordance with contraction. Furthermore, a side face of the compact 2 is set in a state of not coming into contact with a structural member of the energization sintering device. Next, after the interior of the energization sintering device is set in a vacuous or inactive ambience, the compact 2 is energized through both upper and lower electrodes 1, 3. A short rectangular pulse current from a pulse current 4 is used as current, and the energization conditions are in the range of a current density I/A=10 to 1000 A/cm2, a voltage V=1 to 100 V, and a pulse period t=10 to 1000 ms.