| 摘要 |
A preparation process for corrosion-resistant, permanently magnetic powders consisting of an alloy of the basic type Se-Fe-B used in magnet manufacturing, the magnetic powders prepared in this way being characterised by excellent resistance to oxidation and being capable of being processed, without sintering, into isotropic or anisotropic magnets with high coercitivity field strengths and maximum energy product. This is achieved by the original alloy, provided in pieces or in the form of ingots, being crushed, the powder particles produced in this way being heat-treated to improve their magnetic characteristics, preferably in a temperature range from 300 - 1000 DEG C, and the surfaces of the individual heat-treated powder particles subsequently being coated with a ceramic or metallic protective layer, to prevent corrosion, the metallic coating preferably being applied by electrolytic means from an aqueous solution. The invention also relates to a magnet of permanently magnetic powder which is characterised by the powder particles consisting of an alloy containing 25-45% by weight of Se, 0.5-3% by weight of B and iron or a combination of iron with at least one other metal of the cobalt, aluminium and niobium group, and by being coated with a ceramic or metallic protective coating. |
