Howmet Research Corporation

Howmet Corporation

Joel Lee Cockerill

Bruce M Warnes

John Edward Schilbe

Kenneth S Murphy

Andrew L Purvis

Irving R McFarren

Alexander J Nordin

Irving R Mcfarren

An outwardly grown diffusion aluminide bondcoat is formed on a superalloy substrate and has higher concentrations of Al and Pt and lower concentrations of harmful impurities (e.g. Mo, W, Cr, Ta, S, etc.) at an outermost region of the bondcoat than at an innermost region thereof adjacent the substrate. The bondcoat is pretreated prior to deposition of a ceramic thermal insulative layer in a manner that reduces grain boundary ridges on the outermost bondcoat surface without adversely affecting the outermost region thereof, and then is heat treated to thermally grow a stable alpha alumina layer on the bondcoat prior to deposition of a ceramic layer.

Thermal barrier coating method and article

Method of forming an outwardly grown aluminide diffusion coating on a superalloy substrate disposed in a coating retort including the steps of heating the substrate to a temperature of 900 to 1200 degrees C., flowing a coating gas comprising aluminum trichloride and a carrier gas through the coating retort at a flow rate of the coating gas of about 100 to about 450 standard cubic feet per hour, providing a concentration of aluminum trichloride in the retort of less than 1.4% by volume of the coating gas, and providing a total pressure of the coating gas in the coating retort of about 100 to about 450 Torr.

Method of forming aluminide diffusion coatings

Thermal barrier coating method

Manufacture of superalloy component wherein the component is blasted with abrasive grit particles at one or more stages during the manufacture, is treated with a chemical grit removal medium effective to dissolve and remove abrasive grit particles from the surface of the component without degradation of the component (substrate), and then is coated with a protective coating such that entrapped grit particles are substantially reduced or eliminated from the coating.

Superalloy component with abrasive grit-free coating

A gas turbine engine component having a thermal barrier coating is immersed in an inorganic hydroxide bath having a high concentration of alkali or alkaline earth hydroxide with the bath at ambient (atmospheric) pressure and elevated temperature for a time sufficient to effect rapid detachment of the thermal barrier coating for removal from the substrate. The component then optionally can be immersed in a water bath to remove any remaining thermal barrier coating. The thermal barrier coating is removed without detectable damage to the substrate or any bondcoat present thereon.

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Montague, MI, United States of America

Joel Lee Cockerill