METHOD FOR PROTECTING SURFACE OF NICKEL BASE ARTICLE WITH CORROSION-RESISTANT ALUMINUM ALLOY LAYER

摘要

PROBLEM TO BE SOLVED: To protect a surface of a nickel-base article, e.g. an internal surface (36) of a gas turbine airfoil (22) with a protective layer (40) of aluminum and at least one other element. SOLUTION: A donor alloy is brought into contact with the protected surface of the article to form the protective layer (40). The article and the donor alloy are simultaneously heated to a coating temperature that is greater than about 0.7 of the absolute solidus temperature of the donor alloy but is such that the donor alloy remains in the form of a condensed phase contacting the protected surface of the article. Then the donor alloy is interdiffused into the protected surface of the article.