| 摘要 |
PURPOSE:To obtain a bonded magnet with excellent flame-retardant properties which can be widely applied to an electric equipment such as a sensor field magnet, a driving magnet or a convergence correction magnet by covering rare-earth cobalt system alloy magnet powder with inorganic oxidation-resistant material. CONSTITUTION:A bonded magnet is composed of alloy magnet powder covered with inorganic oxidation-resistant material, flame-retardant agent and organic binder. The employed rare-earth magnet powder is expressed by a general formula Rm5, wherein R denotes rare-earth metal element such as samarium, praseodymium, cerium, neodymium or yttrium and M denotes transition metal element such as cobalt. In order to make the rare-earth magnet powder exhibit magnetic characteristics, the average grain size is normally less then 10mum. A covering is formed by coating the surface of the alloy magnet powder with oxidation-resistant fine inorganic material. The organic binder is suitably selected among generally used thermoplastic resin, thermosetting resin or rubber. |
