Abstract: 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.

Abstract: 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.

Abstract: 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.