Oxidation-resistant coated superalloy

1. An article comprising:

a Ni-based superalloy substrate comprising, by weight percent: 2.0-5.1 Cr; 0.9-3.3 Mo; 3.9-9.8 W; 2.2-6.8 Ta; 5.4-6.5 Al; 1.8-12.8 Co; 2.8-5.8 Re; 2.8-7.2 Ru; and

a coating comprising, exclusive of Pt group elements, by weight percent: Ni as a largest content; 7.4-9.0 Al; 9.3-11.9 Cr; 7.4-9.0 Co; 0.0 Ta; 0.0 W; 0.0 Mo; 0.1-0.5 Hf; 0.1-0.3 Si; 0.3-0.6 Y; 0.1-0.5 Zr; and 0.0 Re,

wherein:

the coating has less than 0.50 weight percent Ru, if any; and

in weight percent exclusive of Pt group elements, the coating has less than 1.0 weight percent individually elements other than said Ni, Al, Cr, Co, Ta, W, Mo, Hf, Si, Y, Zr, Re, Ru, and Pt group elements, if any.

2. The article of claim 1 wherein:

the substrate comprises 0.05-0.7 weight percent Hf.

3. The article of claim 1 wherein:

the substrate has a 1800° F. & 45 ksi (982° C. & 310 MPa) rupture life of at least 120 hours.

4. The article of claim 1 wherein:

the substrate is a single crystal alloy.

5. The article of claim 1 wherein:

the coating has less than 1.0 weight percent overall said Pt group elements combined.

6. The article of claim 1 wherein:

in weight percent the coating has 55.0≤Ni+Cr≤67.0 and Ni≥52.

7. The article of claim 1 wherein:

the coating has said weight percent combined of said Y, Hf, Zr, and Si of up to 1.5 weight percent.

8. The article of claim 1 wherein:

a SRZ, if any, is less than 0.001 inch (0.025 mm) thick.

9. The article of claim 1 being a turbine blade.

10. The article of claim 1 wherein at least one of:

the substrate is a single crystal alloy;

the substrate has a density of 0.315-0.327 pounds per cubic inch (8.72-9.05 g/cm 3 ); and

the substrate has a creep resistance of at least 50° F. (28° C.) greater than that of PWA1484.

11. An article comprising:

a Ni-based superalloy substrate comprising, by weight percent: 2.0-3.0 Cr; 2.0-3.0 Mo; 7.0-9.0 W; 2.0-4.0 Ta; 5.0-6.0 Al; 7.0-9.0 Co; 3.0-5.0 Re; 4.0-6.0 Ru; and

a coating comprising, exclusive of Pt group elements, by weight percent: Ni as a largest content; 6.3-7.7 Al; 4.1-5.3 Cr; 11.8-14.2 Co; 5.0-6.2 Ta; 4.3-5.3 W; 0.0 Mo; 0.1-0.5 Hf; 0.2-0.4 Si; 0.3-0.7 Y; 0.0 Zr; and 0.0 Re,

wherein:

in weight percent exclusive of Pt group elements, the coating has less than 1.0 weight percent individually elements other than said Ni, Al, Cr, Co, Ta, W, Hf, Si, Y, and Pt group elements, if any.

12. An article comprising:

a Ni-based superalloy substrate comprising, by weight percent: 2.0-5.1 Cr; 0.9-3.3 Mo; 3.9-9.8 W; 2.2-6.8 Ta; 5.4-6.5 Al; 1.8-12.8 Co; 2.8-5.8 Re; 2.8-7.2 Ru; and

a coating comprising, exclusive of Pt group elements, by weight percent: Ni as a largest content; 6.3-7.7 Al; 4.1-5.3 Cr; 11.8-14.2 Co; 5.0-6.2 Ta; 4.3-5.3 W; 0.0 Mo; 0.1-0.5 Hf; 0.2-0.4 Si; 0.3-0.7 Y; 0.0 Zr; and 0.0 Re,

wherein:

the coating has less than 0.50 weight percent Ru, if any; and

in weight percent exclusive of Pt group elements, the coating has less than 1.0 weight percent individually elements other than said Ni, Al, Cr, Co, Ta, W, Mo, Hf, Si, Y, Zr, Re, Ru, and Pt group elements, if any.

13. The article of claim 12 wherein:

the substrate comprises 0.05-0.7 weight percent Hf.

14. The article of claim 12 wherein:

the substrate has a 1800° F. & 45 ksi (982° C. & 310 MPa) rupture life of at least 120 hours.

15. The article of claim 12 wherein:

a SRZ, if any, is less than 0.001 inch (0.025 mm) thick.

16. The article of claim 12 being a turbine blade.

17. The article of claim 12 wherein at least one of:

the substrate is a single crystal alloy;

the substrate has a density of 0.315-0.327 pounds per cubic inch (8.72-9.05 g/cm 3 ); and

the substrate has a creep resistance of at least 50° F. (28° C.) greater than that of PWA1484.

18. The article of claim 12 wherein:

the coating has less than 1.0 weight percent overall said Pt group elements combined.

19. The article of claim 12 wherein:

the substrate is a single crystal alloy.