A method of both coating a substrate with aluminum oxide and infusing the substrate with elemental aluminum is disclosed. In one example, the method includes providing a metal powder/polymer binder slurry, the slurry having a solvent, an organic binder, metal granules and a seed element, wherein the metal granules include Al; dispersing the slurry upon a Cr-containing surface; after dispersing the slurry, exposing the slurry to air and maintaining the temperature of the slurry and substrate below 110.degree. C. to remove at least a portion of the solvent from the slurry; and, in a combined step, both exposing the binder, metal granules and substrate to air and heating the remaining slurry and substrate at a temperature less than or equal to 1000.degree. C. to both diffuse at least a portion of the metal of the metal granules into the substrate and coat the substrate with aluminum oxide.