Abstract: A method of forming a metal coating on surfaces of internal passages of a turbine blade includes, in an exemplary embodiment, the steps of positioning the turbine blade in a CVD chamber, coupling a reagent gas manifold to at least one internal passage inlet, and coating the surfaces of the at least one internal passage by a CVD process using metal coating reagent gases to form a metal coating on the surfaces of the at least one internal passage.

Abstract: A method of removing a virgin metal oxide coating from the surface of a superalloy gas turbine engine component. The component bearing the applied metal oxide coating is contacted with an aqueous coating-removal solution, typically containing by weight about 10-25% alkali hydroxide, about 1-8% alkanolamine, and about 0.5-5% gluconate salt at a temperature of from about 170° F. (67° C.) to about 210° F. (99° C.), for a time sufficient to remove the metal oxide coating from the superalloy blade by gentle mechanical means. The metal oxide coating can comprise one or more metal oxide layers, such as a chromium oxide layer and an aluminum oxide layer.

Abstract: An article comprising a substrate and an outer metallic layer, such as a coating, is provided with augmented heat transfer from the substrate through the combination of a layer thickness of about 0.003″ to about 0.017″, a layer surface roughness of at least about 500 micro inches Ra, a layer tensile bond strength of at least about 5 ksi, and a heat transfer augmentation of at least about 1.1. A method of making the article uses an electric arc wire thermal spray process in which the atomizing gas pressure is maintained within the range of about 20-80 psi.

Abstract: Apparatus for producing a metal powder includes a cooled hearth structure in which a metallic alloy is melted and a heat source above the hearth positioned to heat the melt in the hearth. The cooling of the hearth causes a protective hearth skull to form between the melt and the hearth itself. The hearth is placed within an environmental control chamber. A supply structure provides a continuous supply of the metallic alloy to the hearth structure from the exterior of the chamber. A metal powder producer is positioned to receive molten metal from the hearth, and a continuous stream of the molten alloy from the hearth is transferred to the metal powder producer. The transfer is accomplished by tipping the hearth or by teeming through an opening in the bottom of the hearth. The hearth structure can utilize two individual hearths, controllably arranged so that molten metal is drawn from one hearth while the other is recharged.