United Technologies Corporation

Michael S Milaniak

Walter E Olson

Dinesh K Gupta

Foster Philip Lamm

David E DeSaulniers

Clark T Okawa

Dennis J Orzel

An aqueous slurry process for producing a diffusion aluminide protective coating in superalloy articles, particularly on internal passages in superalloy articles. Aqueous slurry containing a source of aluminum in particulate form, an inert ceramic particulate, a halide activator compound in particulate form and a viscous aqueous base dispersant is injected into the internal passage or otherwise coated on the internal surface to be protected. The coated article is heated to dry the slurry and remove the aqueous solvent base. The dried, coated article is diffusion heat treated between about 1,350.degree. F. and 2,250.degree. F. for a period of time between approximately 4 hours and 24 hours to transfer the aluminum to the surfaces of the passages and diffuse the aluminum into the substrate material to form the protective coating.

Aqueous slurry coating system for aluminide coatings

A powder mixture for applying gas phase aluminide coatings to nickel or cobalt base superalloys is described. A preferred mixture consists essentially of Co.sub.2 Al.sub.5, NH.sub.4 F.HF, and chromium metal. The mixture is substantially free of aluminum oxide.

Method for applying aluminide coatings to superalloys

Methods are described for forming an yttrium enriched aluminide coating on the surface of a nickel or cobalt base superalloy article. In one preferred embodiment, a pack mixture for forming the coating consists essentially of, by weight percent, 5-35 of an Al-Y-Si alloy, 1-20 CoI.sub.2, balance Y.sub.2 O.sub.3.

Powder mixture for making yttrium enriched aluminide coatings

Yttrium enriched aluminide coatings

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Middlefield, CT, United States of America

Michael S Milaniak