Abstract: Oxidation of fully dense rare earth magnets is reduced when a passivating agent such as an oxidation resistant composition or corrosion inhibitor or combinations thereof, is coated thereon. The oxidation resistant composition is a binary or a ternary composition made from (a) at least one amino containing silane compound such as an aminosilane or a polyaminosilane, or (b) at least one epoxy resin, or (c) an epoxy silane compound, or all three such compounds. The oxidation resistant composition, the corrosion inhibitor, or combinations thereof, passivate the surface of the fully dense rare earth magnets and generally form a highly concentrated coating on the surface thereof. Antidegradants are optionally utilized to improve the performance of the fully dense rare earth magnets with regard to improved oxidation resistant properties and generally include organic phosphorus compounds and/or alcohols.
Type:
Grant
Filed:
January 24, 1991
Date of Patent:
December 22, 1992
Assignee:
The B. F. Goodrich Company
Inventors:
E. Douglas Dickens, Jr., Anthony M. Mazany