Abstract: A process for forming an oxidation and corrosion resistant coating on selective surfaces of an airfoil providing a chamber having an external wall which receives a hollow sleeve for defining an internal space and an annular space between the external wall and sleeve. The airfoil to be coated is located within the internal space. An activator is provided in the internal space below the airfoil. The chemical coating composition is located in the annular space. The chamber is closed and heated to a desired temperature for a sufficient time to coat selective surfaces of the airfoil with the coated composition.

Abstract: A coating apparatus is provided which comprises a can defining an internal chamber. A hollow sleeve which itself defines an internal space is located within the chamber. The hollow sleeve defines with the can an annular space. A plurality of perforations are located in the wall of the hollow sleeve for communicating the annular space with the internal space defined by the sleeve. A lid for enclosing the can and the hollow sleeve is secured to the can for forming a closed compartment.

Abstract: The present invention relates to a composition for coating internal surfaces of an airfoil, particular high pressure temperature airfoils such as vanes and blades. The composition includes a dry composition consisting essentially of from about 2.5 wt % to about 7.0 wt % aluminum fluoride, from about 5.0 wt % to about 20 wt % of a chromium-aluminum powder, and from about 75 wt % to about 92.5 wt % Al.sub.2 O.sub.3. The dry composition is mixed with water and a cellulose compound to form a slurry which is thereafter injected into the airfoil. The coating compositions of the present invention are valuable in that they are capable of forming an oxidation and corrosion resistant coating on the internal surfaces of the airfoil simultaneously with the formation of an exterior corrosion and oxidation resistant coating. A process for simultaneously forming corrosion and oxidation resistant coatings on the interior and exterior surfaces of an airfoil is described herein.

Abstract: The present invention relates to a composition for coating internal surfaces of an airfoil, particular high pressure temperature airfoils such as vanes and blades. The composition includes a dry composition consisting essentially of from about 2.5 wt % to about 7.0 wt % aluminum fluoride, from about 5.0 wt % to about 20 wt % of a chromium-aluminum powder, and from about 75 wt % to about 92.5 wt % Al.sub.2 O.sub.3. The dry composition is mixed with water and a cellulose compound to form a slurry which is thereafter injected into the airfoil. The coating compositions of the present invention are valuable in that they are capable of forming an oxidation and corrosion resistant coating on the internal surfaces of the airfoil simultaneously with the formation of an exterior corrosion and oxidation resistant coating. A process for simultaneously forming corrosion and oxidation resistant coatings on the interior and exterior surfaces of an airfoil is described herein.