Oxidation resistant superalloy and article

• US 20050271886A1
• Filed: 03/24/2005
• Published: 12/08/2005
• Est. Priority Date: 10/30/2000
• Status: Abandoned Application

• Current Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Cetel, Alan D.
• Application Number:
  US11/089,392
• Publication Number:
  US 20050271886A1
• Time in Patent Office: Days
• US Class Current: 428/472
• CPC Class Codes: C22C 19/056 with the maximum Cr content being at least 10% but less than 20%
• CPC Class Codes: C22C 19/057 with the maximum Cr content being less 10%
• CPC Class Codes: C23C 28/321 with at least one metal alloy layer
• CPC Class Codes: C23C 28/3215 at least one MCrAlX layer
• CPC Class Codes: C23C 28/345 with at least one oxide layer
• CPC Class Codes: C23C 28/3455 with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer
• CPC Class Codes: F01D 5/288 Protective coatings for blades

Abstract

An oxidation resistant, nickel base superalloy is described. The combination of alloy and a thermal barrier coating can be used to fabricate turbine components with good high temperature strength and good oxidation resistance, while maintaining other relevant properties.

Claims

1. A nickel base superalloy in weight percent consisting essentially of:

about 7.5 to about 12.5% Cr;

about 4.5 to about 5.5% Al;

up to about 2% Ti;

about 3.5 to about 4.5% W;

about 11.5-12.5% Ta;

about 3-16% Co;

about 0.2 to about 0.5% Hf

no intentional addition of Y, and less than 300 ppm;

no intentional addition of Zr, and less than 500 ppm;

up to about 0.05% C;

up to about 0.005% B;

up to about 8.5% of additional elements selected from the group consisting of Mo, Re, Nb and V;

balance essentially Ni; and

wherein

P=−

200 Cr+80 Mo²−

250 Ti²−

50 (Ti×

Ta)+15 Cb+200 W−

14 W²+30 Ta−

1.5 Ta²+0.5 Co+1200 Al−

100 Al²+100 Re+1000 Hf−

2000 Hf²+700 Hf³−

2000 V−

500 C−

15000 B−

500 Zr, wherein P is less than about 2500, and wherein the alloy has oxidation resistance at least about 25% greater than an alloy having a nominal composition of 10% Cr, 5% Co, 4% W, 1.5% Ti, 5% Al, balance Ni.

2. An alloy as in claim 1 wherein the quantity Al+Ti+0.2 Ta (in wt %) ranges from 7-10%, and the quantity W+0.8 Ta ranges from 12-18%.

3. An alloy as in claim 1 wherein C is less than 0.05%, B is less than 0.005%, Zr is less than 0.5% and Y is less than 30 ppm.

4. An alloy as in claim 1, wherein P is less than about 1800.

5. An alloy as in claim 1, wherein Y is less than 50 ppm, and the additional elements selected from the group consisting of Mo, Re, Nb and V is less than 1.

9. A superalloy article as in claim 1 having a single crystal microstructure.

10. A superalloy article as in claim 1 having a columnar microstructure.

6. A nickel base superalloy composition consisting essentially of:

A nickel base superalloy in weight percent consisting essentially of;

about 9 to about 11% Cr;

about 4.75 to about 5.25% Al;

about 1 to about 2% Ti;

about 3.5 to about 4.5% W;

about 11.5-12.5% Ta;

about 4-6% Co;

about 0.25 to about 0.45% Hf

no intentional addition of Y, and less than 300 ppm;

no intentional addition of Zr, and less than 300 ppm;

up to about 0.01% C;

up to about 0.005% B;

up to about 8.5% of additional elements selected from the group consisting of Mo, Re, Nb and V;

balance essentially Ni; and

wherein

P=−

200 Cr+80 Mo²−

250 Ti²−

50 (Ti×

Ta)+15 Cb+200 W−

14 W²+30 Ta−

1.5 Ta²+0.5 Co+1200 Al−

100 Al²+100 Re+1000 Hf−

2000 Hf²+700 Hf³−

2000 V−

500 C−

15000 B−

500 Zr, wherein P is less than about 2500, and wherein the alloy has oxidation resistance at least about 25% greater than an alloy having a nominal composition of 10% Cr, 5% Co, 4% W, 1.5% Ti, 5% Al, balance Ni.

7. A composition as in claim 6 where in the quantity Al+Ti+0.2 Ta (in wt %) ranges from 7-10, and the quantity W+0.8 Ta (in wt. %) ranges from 12-18%.

8. A composition as in claim 6 wherein C is less than 0.05%, B is less than 0.005%, Zr is less than 0.05%, and Y is less than 0.003%.

11. A single crystal superalloy gas turbine engine blade which comprises:

a. about 7.5 to about 12.5% Cr;

about 4.5 to about 5.5% Al;

up to about 2% Ti;

about 3.5 to about 4.5% W;

about 11.5-12.5% Ta;

about 3-16% Co;

about 0.2 to about 0.5% Hf

no intentional addition of Y, and less than 300 ppm;

no intentional addition of Zr, and less than 500 ppm;

up to about 0.05% C;

up to about 0.005% B;

up to about 8.5% of additional elements selected from the group consisting of Mo, Re, Nb and V;

balance essentially Ni; and

wherein

P=−

200 Cr+80 Mo²−

250 Ti²−

50 (Ti×

Ta)+15 Cb+200 W−

14 W²+30 Ta−

1.5 Ta²+0.5 Co+1200 Al−

100 A12+100 Re+1000 Hf−

2000 Hf²+700 Hf³−

2000 V−

500 C−

15000 B−

500 Zr, wherein P is less than about 2500, and wherein the alloy has oxidation resistance at least about 25% greater than an alloy having a nominal composition of 10% Cr, 5% Co, 4% W, 1.5% Ti, 5% Al, balance Ni;

b. an aluminum containing coating on the substrate, the coating being capable of forming a durable adherent alumina scale,

c. a ceramic thermal barrier coating adhering to said alumina scale.

12. A gas turbine blade as in claim 11 wherein said thermal barrier coating has a columnar microstructure.

13. A gas turbine blade as in claim 11, wherein the aluminum containing coating is an overlay coating.

14. A gas turbine blade as in claim 11, wherein the aluminum containing coating is an aluminide.