Abstract: A method of refurbishing a transition duct (100) for a gas turbine system includes providing the transition duct. The transition duct has a first wall (221) defining a first passageway (110) and having holes (223) through a metal layer (322) and a ceramic layer (323), and the transition duct also has a second wall (222) adjacent to and separate from the first wall and external to the first passageway, where the first and second walls define a second passageway (210) coupled to the first passageway through the holes in the first wall. The method further includes masking the holes in the first wall, sealing the first passageway, and after sealing the first passageway, using a liquid etchant to chemically remove the ceramic layer from the first wall while keeping the liquid etchant out of the second passageways.

Abstract: The present invention relates generally to an oxidation and corrosion resistant coating composition produced by a vapor phase co-deposition of transition metals on metallic components. In particular, this coating includes aluminum and silicon and the coated substrate may comprise precious metal, nickel, cobalt or MCrALY. Such coatings are particularly useful in protecting nickel and cobalt and iron-based superalloys from heat corrosion and oxidation attack, especially during high temperature operation, e.g., gas turbine and jet engine hot zones.

Abstract: The present invention relates generally to an oxidation and corrosion resistant coating composition produced by a vapor phase co-deposition of transition metals on metallic components. In particular, this coating includes aluminum and silicon and the coated substrate may comprise precious metal, nickel, cobalt or MCrALY. Such coatings are particularly useful in protecting nickel and cobalt and iron-based superalloys from heat corrosion and oxidation attack, especially during high temperature operation, e.g., gas turbine and jet engine hot zones.