Article with intermediate layer and protective layer, and its fabrication

A protected article comprising:

• a nickel-base superalloy substrate;
• an interlayer overlying the substrate, wherein the interlayer comprises from about 15 to about 35 percent by volume of alpha chromium phase;
• and
• a protective layer overlying the interlayer, the protective layer having a composition comprising rhodium, platinum, and palladium, wherein the palladium is present in an amount of from about 1 to about 41 atomic percent, the platinum is present in an amount of about (40+atomic percent palladium) atomic percent for palladium ranging from about 1 atomic percent to about 14 atomic percent and up to about 54 atomic percent for palladium ranging from about 15 atomic percent up to about 41 atomic percent, rhodium in an amount of at least about 24 atomic percent, zirconium, hafnium, titanium, and mixtures thereof in an amount from zero up to about 5 atomic percent, ruthenium in an amount from zero up to about 5 atomic percent, balance impurities, wherein the interlayer has a coefficient of thermal expansion intermediate between that of the substrate and that of the protective layer.

A method for protecting an article, comprising the steps of

• furnishing a substrate comprising a nickel-base alloy;
• applying an interlayer overlying the substrate;
• and
• applying a protective layer overlying the interlayer, the protective layer having a composition comprising at least one element selected from the group consisting of rhodium, platinum, palladium, and ruthenium, balance other elements and impurities.