High-temperature coatings with pt metal modified gamma-ni+gamma'-ni3al alloy compositions

A coating on a substrate, wherein the coating is an alloy which comprises:

• aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein the alloy consists essentially of gamma prime Ni3Al phase and either beta NiAl phase or gamma Ni phase.

A coating on a superalloy substrate of a gas turbine, wherein the coating is an alloy which comprises:

• about 10 at % to about 23 at % aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein
• the alloy consists essentially of gamma prime Ni3Al phase and either beta NiAl phase or gamma Ni phase, and
• the alloy is predominantly gamma prime Ni3Al phase.

A coating on a superalloy substrate of a gas turbine, wherein the coating is an alloy which comprises:

• about 10 at % to about 23 at % aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein the alloy consists essentially of gamma prime and beta NiAl phase or gamma Ni phase.

A coating on a substrate, wherein the coating is an alloy which comprises:

• about 10 at % to about 23 at % aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein
• the alloy consists essentially of gamma prime Ni3Al phase and either beta NiAl phase or gamma Ni phase, and
• the coating has an innermost region with a platinum group metal content of greater than the average platinum group metal content in the coating.

A coating on a substrate, wherein the coating is an alloy which comprises:

• aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein the alloy comprises gamma prime Ni3Al phase and either beta NiAl phase or gamma Ni phase.

A coating on a superalloy substrate of a gas turbine, wherein the coating is an alloy which comprises:

• about 10 at % to about 23 at % aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein
• the alloy comprises gamma prime Ni3Al phase and either beta NiAl phase or gamma Ni phase, and
• the alloy is predominantly gamma prime Ni3Al phase.

A coating on a superalloy substrate of a gas turbine, wherein the coating is an alloy which comprises:

• about 10 at % to about 23 at % aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein the alloy comprises gamma prime and beta NiAl phase or gamma Ni phase.

A coating on a substrate, wherein the coating is an alloy which comprises:

• about 10 at % to about 23 at % aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein
• the alloy comprises gamma prime Ni3Al phase and either beta NiAl phase or gamma Ni phase, and
• the coating has an innermost region with a platinum group metal content of greater than the average platinum group metal content in the coating.

A coating on a substrate, wherein the coating is an alloy which comprises:

• aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein the alloy is predominantly gamma prime Ni3Al phase and also contains either beta NiAl phase or gamma Ni phase.

A coating on a substrate, wherein the coating is an alloy which comprises:

• aluminum,
• nickel,
• at least one platinum group metal, and
• about 0.5 at % to about 2 at % hafnium,
• wherein the alloy has a predominantly gamma nickel and gamma prime Ni3Al phase constitution.