| 摘要 |
PURPOSE:To obtain a high-performance anisotropic resin-bonded magnet at a low cost by a method wherein a powder, which has been obtained by quenching an alloy composed of light rare-earth elements, heavy rare-earth elements, a transition metal and boron at a cooling speed in a specific range, is worked at more than a specific temperature and a crushed powder is resin- bonded. CONSTITUTION:An alloy whose basic components are light rare-earth elements, heavy rare-earth elements, a transition metal and boron is melted and cast; a powder, a lamina or an ingot which has been formed by quenching the alloy at a cooling speed of 10<0>-10<5> deg.C/sec is worked at a temperature of 500 deg.C or higher; an anisotropic magnet is formed; a crushed powder is resin-bonded. For example, an ingot of Nd10R5Fe77B8 (where R is Dy, Tb, Ho) is melted in an induction furnace; it is crushed to an average particle diameter of about 5mum; it is molded in a magnetic field and sintered at 1060 deg.C for three hours. The sintered magnet is crushed again; it can be crushed mechanically down to an average particle diameter of 20mum; an epoxy resin is added and kneaded mechanically. This mixture is molded in a magnetic field; after that, the resin is hardened at 120 deg.C for two hours; a resin-bonded magnet can be obtained. |
