Patent ID: 7592051

Claim:
A method for protecting a copper-based alloy component against high temperature oxidation, comprising the steps of: (a) placing the copper-based alloy component in a chamber adapted to function at reduced pressures including a copper metal source, a chromium metal source, an electron beam source and an ion beam source; (b) evacuating the chamber to provide a partial vacuum therein; and (c) vapor depositing said copper metal source or said chromium metal source by said electron beam and activating said ion beam source and directing ions at said copper-based alloy component and forming a coating on the copper-based alloy component, wherein the coating has a total thickness of less than about 10 μm and comprises alternating layering of at least one substantially chromium-free layer comprising copper and at least one substantially copper-free layer comprising chromium; wherein the chromium content of the coating is greater than about 8 weight percent and less than 16.5 weight percent and wherein the copper and chromium particles deposited on the copper-based alloy component are of a diameter less than about 10 nm, wherein said Cu—Cr coating in the presence of oxygen over a period of three hours or less has a mass gain of less than or equal to about 200 micrograms per square centimetre at 650° C.