Oxidation-resistant coated superalloy
A coating-substrate combination includes: 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; 5.8-9.3 Al; 4.4-25 Cr; 3.0-13.5 Co; up to 6.0 Ta, if any; up to 6.2 W, if any; up to 2.4 Mo, if any; 0.3-0.6 Hf; 0.1-0.4 Si; up to 0.6 Y, if any; up to 0.4 Zr, if any; up to 1.0 Re, if any.
1. An article comprising:
a Ni-based superalloy substrate falling within one of the “Broad” ranges of Table VI; and
a coating comprising, exclusive of Pt group elements, by weight percent: Ni as a largest content; 6-8 Al; 3-6 Cr; 9-15 Co; 5-7 Ta; 4-6 W; 0 Mo; 0.050-0.70 Hf; 0.1-0.5 Si; 0.1-0.7 Y; 0 Zr; 0 Ru; and 0 Re.
2. The article of claim 1 wherein:
the coating comprises 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 Mo; 0.1-0.5 Hf; 0.2-0.4 Si; 0.3-0.7 Y; 0 Zr; 0 Ru; and 0 Re.
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 coating comprises exclusive of Pt group elements, by weight percent: 0.4-0.6 said Hf; and 0.2-0.4 said Si.
5. The article of claim 4 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 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, and Pt group elements, if any.
7. The article of claim 1 wherein:
the substrate falls within one of the “Narrow” ranges of Table VI with balance nickel plus impurities.
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 falling within one of the “Broad” ranges of Table VI; and
a coating comprising, exclusive of Pt group elements, by weight percent: Ni as a largest content; 7.0-10.0 Al; 9.0-12.0 Cr; 11.0-15.0 Co; 0.0 Ta; 0.0 W; 0.0 Mo; 0.05-0.7 Hf; 0.1-0.5 Si; 0.1-0.7 Y; 0.05-0.7 Zr; 0.0 Ru; and 0.0 Re.
12. The article of claim 11 wherein:
the coating comprises, exclusive of Pt group elements, by weight percent: Ni as a largest content; 7.4-9.0 Al; 9.3-11.9 Cr; 11.8-14.2 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; 0.0 Ru; and 0.0 Re.
13. The article of claim 11 being a turbine blade.
14. The article of claim 11 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.
15. The article of claim 11 wherein:
the substrate falls within one of the “Narrow” ranges of Table VI with balance nickel plus impurities.
16. The article of claim 15 wherein:
the coating comprises exclusive of Pt group elements, by weight percent: 0.4-0.6 said Hf; and 0.2-0.4 said Si.
17. The article of claim 16 wherein:
the coating has less than 1.0 weight percent overall said Pt group elements combined.
18. The article of claim 11 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, Mo, Hf, Si, Y, Zr, Re, and Pt group elements, if any.
19. An article comprising:
a Ni-based superalloy substrate falling within one of the “Broad” ranges of Table VI; and
a coating comprising, exclusive of Pt group elements, by weight percent: 7.0-10.0 Al; 9.0-12.0 Cr; 11.0-15.0 Co; 0.05-0.7 Hf; 0.1-0.5 Si; 0.1-0.7 Y; 0.05-0.7 Zr; and Ni balance and less than 0.1 weight percent each, if any, elements other than said Al, Cr, Co, Hf, Si, Y, Zr, and Ni.
20. The article of claim 19 being a turbine blade.