METHOD OF MANUFACTURING R-Fe-B BOND MAGNETS OF HIGH CORROSION RESISTANCE

摘要

A method of manufacturing R-Fe-B bond magnets, capable of forming various corrosion resisting films on a R-Fe-B bond magnet uniformly with a very high bond strength so as to attain such a very high corrosion resistance thereof that prevents the bond magnet from being rusted even in a long-period high-temperature high-humidity test; comprising barrel-polishing a porous R-Fe-B bond magnet by a dry method using as media an abrasive stone formed by sintering inorganic powder of Al2O3, SiC, ZrO and MgO, or a mixture of an abrasive for metal balls and vegetable media, such as vegetable skin chips, sawdust, rind of a fruit and a core of corn, or a mixture of vegetable media the surfaces of which are modified by the above-mentioned abrasive and the above-mentioned inorganic pulverized bodies, so as to enable a surface of the magnet to be smoothed and sealed; or immersing a magnet material in a neutral or alkali bath so as to enable a layer of electroless plating to be formed thereon; or subjecting a magnet material to electrolytic plating so as to enable a film of markedly high bond strength and dimensional accuracy to be formed thereon, whereby an object R-Fe-B bond magnet of a high dimensional accuracy and a high corrosion resistance is obtained.