| 摘要 |
PROBLEM TO BE SOLVED: To provide an arcuate permanent magnet which has a performance-to-price ratio matching that of the hard ferrite magnet and can contribute to the size reduction of a magnetic circuit, without using any pulverizing method nor bond magnet forming method nor requiring any cutting work after molding. SOLUTION: In a method for manufacturing arcuate permanent magnet, an amorphous thin belt which has high toughness and an average thickness of 10-100 μm and can be worked easily is produced by quenching a molten alloy having a specific composition containing <=6 at.% rare-earth elements and 15-50 at.% boron under a specific condition. Then, a curved laminated thin belt having a microcrystalline structure is formed by laminating two or more pieces of the amorphous belt so that the thickness of the laminated body may become an arbitrary value and heat-treating the laminated body, until a microcrystalline structure of 10-50 nm in average crystal grain diameter is obtained in the laminated body, while the laminated body is curved in a desired shape by means of a holding apparatus. Thereafter, an arcuate permanent magnet which has a high performance, a price-to-performance ratio matching to that of a hard ferrite magnet, a hard magnetic characteristic of iHc>=2 kOe and Br>=8 kG, and an average thickness of >=20 μm and can contribute to the size reduction and performance improvement of household electric appliances, office automation equipment, electric appliances, etc., is manufactured by bonding the laminated thin belts to each other. |
