Abstract: A “one-step” method of forming diffused noble metal-aluminide coatings with or without minor incorporations of Si, Cr, Mn, Hf, La, and Y, is disclosed. With the inventive method, two or more powdered metals or metal alloys are applied and diffused into the metal substrate together, using a sequential multi-stage heating process. This method contrasts with the prior art technology where metals were applied and diffused into the substrate separately.

Abstract: A platinum-silicon powder is electrophoretically deposited on a nickel or cobalt base superalloy substrate. The deposited powder is heated to form a transient liquid phase on the substrate and initiate diffusion of Pt and Si into the substrate. An aluminum-chromium powder is then electrophoretically deposited on the Pt-Si enriched substrate and diffusion heat treated to form a corrosion- and oxidation-resistant Pt-Si enriched diffused aluminide coating on the substrate. The presence of both Pt and Si in the aluminide coating unexpectedly improves coating ductility as compared to a Pt-enriched diffused aluminide coating without Si on the same substrate material.