Patent ID: 7357958

Claim:
A process of depositing a coating system on a nickel-base superalloy substrate, the process comprising the steps of: forming on a surface of the substrate a platinum group metal layer and at least one separate layer, the platinum group metal layer containing at least one platinum group metal and the at least one separate layer containing aluminum, optionally nickel, optionally chromium, optionally silicon, and optionally one or more reactive elements; and then diffusion heat treating the platinum group metal layer and the at least one separate layer to form a homogeneous overlay coating on the surface of the substrate, the overlay coating consisting essentially of nickel aluminide intermetallic, the at least one platinum group metal, one or more elements that diffused into the overlay coating from the substrate, optionally chromium, optionally silicon, and optionally the one or more reactive elements, the nickel aluminide intermetallic being predominantly gamma prime phase.