US Patent 7229701 Chromium and active elements modified platinum aluminide coatings

The present invention provides a chromium and active elements modified platinum aluminide coating that may be used on a surface of a gas turbine engine component such as a turbine blade. The coating may be used as a protective coating that impedes the progress of corrosion, oxidation, and sulfidation in superalloy materials that comprise the substrate of the turbine blade. Additionally, the coating may be used as a bond coat onto which a thermal barrier coating is deposited. The presence of active elements as well as chromium and platinum provides improved corrosion, oxidation, and sulfidation resistance. The coating is applied using an electron beam physical vapor deposition. The coating is applied alternatively using selected sequential diffusion processing steps involving chromium, platinum and aluminum.