Method for depositing a variable thickness aluminide coating on aircraft turbine blades
AssigneeUnited Technologies Corporation
InventorsRussell A. Beers, Allan A. Noetzel
Life of this patent
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Abstract
A method for coating articles, such as gas turbine blades, with a coating of variable thickness by securing a shield having one or more holes extending therethrough to the article thereby defining a shielded portion of the article, exposing the article and shield to a metal-bearing gas which is circulated around the article to deposit a metallic coating thereon, wherein the circulation of the gas adjacent the shielded portion of the article is restricted by the presence of the shield, thereby producing a substantially thinner coating on the shielded portion of the article than on the unshielded portion.
Claims3
A method of producing a coating of variable thickness on an exposed surface of a turbine blade, said exposed surface having a shielded portion and an unshielded portion, said method comprising:
- providing a shield for partially shielding said shielded portion of said exposed surface from a metal-bearing gas, said shield including at least one hole to allow said metal-bearing gas to pass therethrough and an edge which conforms to contours of said exposed surface;
- securing said shield in fixed, and spaced, relation to said shielded portion of said exposed surface, defining a shielded region therebetween;
- placing said turbine blade into a coating apparatus;
- heating said turbine blade in said coating apparatus to a temperature in excess of 1700.degree. F.;
- introducing said metal-bearing gas into said coating apparatus;
- and,
- circulating said metal-bearing gas into contact with said shielded portion and said unshielded portion providing a metal coating thereon, whereby circulation of said gas into said shielded region is so restricted that said metal-bearing gas deposits a thinner coating on said shielded portion than on said unshielded portion of said exposed surface.
Dependencies are inferred from the claim text.