Method for selective surface protection of a gas turbine blade which has previously been in service

摘要

A gas turbine blade which has previously been in service is protected by cleaning the gas turbine blade, and then first depositing a platinum first layer on the airfoil and the platform of the gas turbine blade. Thereafter, a platinum second layer is deposited over the platform but not the airfoil. A platinum-aluminide protective coating is formed by depositing an aluminum-containing layer overlying both the platform and the airfoil and interdiffusing the platinum and the aluminum.