Permanent magnet with ferrite and rare earth material and protective surface - provided by nickel@ or nickel@ alloy avoiding corrosion caused by external effects.

摘要

A permanent magnet has an alloy consisting of a base metal such as Fe, together with a rare earth metal having yttrium and born. This is combined with a protective layer of nickel or nickel alloy that is not greater than 30 microns thick. The inter cellular cell spacing within the layer is 14 microns or more. The permanent magnet is produced in a sintering process with particle sizes of 50 microns or less. ADVANTAGE - High corrosion resistance. (Drawings unsuitable for reproduction)