Article having a superalloy protective coating, and its fabrication

An article protected by a protective coating, comprising:

• a substrate having a substrate surface, wherein the substrate is made of a nickel-base superalloy substrate material that is susceptible to the formation of a secondary reaction zone when overlaid by a diffusion aluminide coating or an aluminide overlay coating;
• and
• a deposited coating at the substrate surface, the deposited coating having a protective coating outer surface and a composition, in weight percent, of from about 7.4 to about 7.8 percent chromium, from about 5.3 to about 5.6 percent tantalum, from about 2.9 to about 3.3 percent cobalt, from about 7.6 to about 8.0 percent aluminum, from about 0.12 to about 0.18 percent hathium, from about 0.5 to about 0.6 percent silicon, from about 3.7 to about 4.0 percent tungsten, from about 1.5 to about 1.8 percent rhenium, from about 0.01 to about 0.03 percent carbon, from about 0.01 to about 0.02 percent boron, balance nickel and incidental impurities, wherein
• there is no secondary reaction zone formed by interdiffusion between the substrate and the deposited coating.

A method of fabricating an article protected by a protective coating comprising the steps of:

• providing a substrate having a substrate surface, wherein the substrate is made of a nickel-base superalloy substrate material that is susceptible to the formation of a secondary reaction zone when overlaid by a diffusion aluminide coating or an aluminide overlay coating;
• and
• applying a deposited coating to the substrate surface, the deposited coating having a composition, in weight percent, of from about 7.4 to about 7.8 percent chromium, from about 5.3 to about 5.6 percent tantalum, from about 2.9 to about 3.3 percent cobalt, from about 7.6 to about 8.0 percent aluminum, from about 0.12 to about 0.18 percent hafnium, from about 0.5 to about 0.6 percent silicon, from about 3.7 to about 4.0 percent tungsten, from about 1.5 to about 1.8 percent rhenium, from about 0.01 to about 0.03 percent carbon, from about 0.01 to about 0.02 percent boron, balance nickel and incidental impurities, wherein
• there is no secondary reaction zone formed by interdiffusion between the substrate and the deposited coating.