Article including a substrate with a metallic coating and a protective coating thereon, and its preparation and use in component restoration

A coated article comprising:

• a metallic substrate that is a component of a gas turbine engine and has a substrate composition selected from the group consisting of a nickel-base alloy and a cobalt-base alloy, the metallic substrate having an original thickness;
• a metallic coating overlying and contacting the metallic substrate, wherein the metallic coating is a precipitation-strengthened nickel-base superalloy having a metallic-coating composition different from the substrate composition, and wherein the substrate has previously been in service without the metallic coating thereon, the metallic coating restoring the metallic substrate to about the original thickness and having a thickness of from about 0.003 inch to about 0.015 inch;
• and
• a protective coating overlying and contacting the metallic coating, wherein the protective coating comprises
• a platinum-group metal-aluminide diffusion coating layer overlying and contacting the metallic coating, and
• a ceramic thermal barrier coating overlying and contacting the aluminide diffusion coating layer,
• wherein the coated article is dimensionally;
• and
• wherein the aluminide diffusion coating layer comprises at least about 16 percent by weight aluminum and at least about 16 percent by weight of a platinum group metal.

A method for restoring a key dimension of and protecting an article, comprising the steps of

• providing an article that has previously been in service, wherein the key dimension of the article is below a minimum permissible dimensional value as a result of the previous service, and wherein the article serves as a metallic substrate having a substrate composition having an original thickness and a protective coating overlying the substrate;
• depositing a metallic coating overlying and contacting the metallic substrate to restore the metallic substrate to about the original thickness, wherein the metallic coating has a metallic-coating composition different from the substrate composition and the metallic coating has a thickness of from about 0.0003 inch to about 0.015 inch;
• and
• depositing a protective coating overlying and contacting the metallic coating, wherein the metallic coating and the protective coating together have a restoration thickness sufficient to increase the key dimension to no less than the minimum permissible dimensional value, and wherein the protective coating comprises
• an aluminide diffusion coating layer overlying and contacting the metallic coating,
• wherein the aluminide diffusion coating layer comprises at least about 16 percent by weight aluminum and at least about 16 percent by weight of a platinum group metal;
• and
• a ceramic thermal barrier coating overlying and contacting the aluminide diffusion coating layer;
• and wherein the protective coating is deposited to a thickness sufficient to resist debonding.