MAKING METHOD FOR PERMANENT MAGNETS

摘要

Hard magnets are produced by melting an alloy of 8-30 atom.% rare earth metal; 2-28 B; max 50 Co; max 15 Al; balance Fe plus unavoidable impurities, casting into a block and heat-treating at min 250 deg.C to obtain fine crystals which are aligned in a special direction to harden the magnet. Heat treatment is carried out at 500 deg.C or more. The alloy can be atomised due to its property of easily forming fine grains by hot working and each particle contg. several magnetic R2Fe14B grains with R being a rare earth metal. The powder is mixed with an organic binder and hardened in a power metallurgical method. The magnet is produced at l ow cost.