Environmentally resistant disk

Abstract

An environmentally resistant gas turbine engine disk is disclosed. The disk includes a substrate metal having locally enriched surface regions, the locally enriched surface regions comprising alloying elements present in a higher percentage than found in the substrate metal. A method for making the disk and other articles is also disclosed. The method includes furnishing a plurality of powder particle substrates made of a substrate metal, providing a nonmetallic precursor of a metallic coating material, wherein the metallic coating material includes an alloying element that is thermophysically melt incompatible with the substrate metal, contacting the powder particle substrates with the nonmetallic precursor, and chemically reducing the nonmetallic precursor to form coated powder particles comprising the powder particle substrates having a surface-enriched layer of the metallic coating material thereon, wherein the step of chemically reducing is performed without melting the powder particle substrates.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a gas turbine disk prepared according to the present approach;

FIG. 2 is a block flow diagram of an approach for forming the gas turbine articles of the present invention;

FIG. 3 is a schematic representation of a first embodiment of an apparatus for forming coated powder particles;

FIG. 4 is a schematic representation of a second embodiment of an apparatus for forming coated powder particles; and

FIG. 5 is a schematic cross sectional view of a coated powder particle after chemical reduction.

Claims

1. An environmentally resistant gas turbine engine disk comprising: a disk comprising a substrate metal having locally enriched surface regions, the locally enriched surface regions comprising alloying elements present in a higher percentage than found in the substrate metal, wherein the disk has a rim portion defining an aperture therethrough for receiving a shaft of a gas turbine engine, the rim portion including a plurality of slots equally spaced about the circumference of the rim portion of the disk, each slot configured to receive a turbine engine blade.

2. The environmentally resistant gas turbine engine disk of claim 1, wherein the substrate base metal is a nickel-base superalloy.

3. The environmentally resistant gas turbine engine disk of claim 2, wherein the nickel-base superalloy has a composition, in weight percent, of from about 16.0 percent to about 22.4 percent cobalt, from about 6.6 percent to about 14.3 percent chromium, from about 1.4 percent to about 3.5 percent tantalum, from about 1.9 percent to about 4.0 percent tungsten, from about 1.9 percent to about 3.9 percent molybdenum, from about 0.03 percent to about 0.10 percent zirconium, from about 0.9 percent to about 3.0 percent niobium, from about 2.4 percent to about 4.6 percent titanium, from about 2.6 percent to about 4.8 percent aluminum, up to about 2.5 percent rhenium, from about 0.02 percent to about 0.10 percent carbon, from about 0.02 percent to about 0.10 percent boron, balance nickel and incidental impurities.

4. The environmentally resistant gas turbine engine disk of claim 2, wherein the nickel-base superalloy has a composition, in weight percent, of from about 12 percent to about 14 percent cobalt, from about 15 percent to about 17 percent chromium, from about 3.5 percent to about 4.5 percent molybdenum, from about 3.5 percent to about 4.5 percent tungsten, from about 1.5 percent to about 2.5 percent aluminum, from about 3.2 percent to about 4.2 titanium, from about 0.5 percent to about 1.0 percent niobium, from about 0.01 percent to about 0.04 percent boron, from about 0.01 percent to about 0.06 percent carbon, from about 0.01 percent to about 0.06 zirconium, up to about 0.01 percent vanadium, up to about 0.3 percent hafnium, up to about 0.01 percent yttrium, balance nickel and incidental impurities.

5. The environmentally resistant gas turbine engine disk of claim 1, wherein the alloying elements are selected from the group consisting of calcium, magnesium, hafnium, lanthanum, yttrium, tungsten, molybdenum, niobium, tantalum, chromium, nitrogen, carbon, zirconium, boron, silicon, rhenium, osmium, ruthenium, platinum and combinations thereof.

6. A method for increasing the percentage of retained thermophysical melt incompatible elements in the making of an article, comprising the steps of: furnishing a plurality of powder particle substrates made of a substrate metal;providing a nonmetallic precursor of a metallic coating material, wherein the metallic coating material comprises an alloying element that is thermophysically melt incompatible with the substrate metal;contacting the powder particle substrates with the nonmetallic precursor; andchemically reducing the nonmetallic precursor to form coated powder particles comprising the powder particle substrates having a surface-enriched layer of the metallic coating material thereon, wherein the step of chemically reducing is performed without melting the powder particle substrates and wherein the amount of the thermophysically melt incompatible alloying element retained in the article is substantially the same as the amount provided in the non-metallic precursor of the metallic coating material.

7. The method of claim 6, wherein the step of furnishing includes the step of furnishing superalloy powder particle substrates.

8. The method of claim 7, wherein the step of furnishing includes the step of furnishing powder particle substrates selected from the group consisting of a nickel-base metal, a cobalt-base metal, an iron-base metal, a nickel-iron base metal, a nickel-iron-cobalt base metal, a titanium-base metal, an aluminum-base metal, a magnesium-base metal, and combinations thereof.

9. The method of claim 7, wherein the step of furnishing includes the step of producing the powder particle substrates by atomization of a melt.

10. The method of claim 7, wherein the step of furnishing includes the step of producing the powder particle substrates by a meltless process.

11. The method of claim 6, wherein the alloying element is selected from the group consisting of calcium, magnesium, hafnium, lanthanum, yttrium, tungsten, molybdenum, niobium, tantalum, chromium, nitrogen, carbon, zirconium, boron, silicon, rhenium, osmium, ruthenium, platinum and combinations thereof.

12. The method of claim 6, wherein the step of providing the nonmetallic precursor includes the step of providing a gaseous nonmetallic precursor.

13. The method of claim 6, wherein the article produced has a composition, in weight percent, of from about 16.0 percent to about 22.4 percent cobalt, from about 6.6 percent to about 14.3 percent chromium, from about 1.4 percent to about 3.5 percent tantalum, from about 1.9 percent to about 4.0 percent tungsten, from about 1.9 percent to about 3.9 percent molybdenum, from about 0.03 percent to about 0.10 percent zirconium, from about 0.9 percent to about 3.0 percent niobium, from about 2.4 percent to about 4.6 percent titanium, from about 2.6 percent to about 4.8 percent aluminum, up to about 2.5 percent rhenium, from about 0.02 percent to about 0.10 percent carbon, from about 0.02 percent to about 0.10 percent boron, balance nickel and incidental impurities.

14. The method of claim 6, wherein the article produced has a composition, in weight percent, of from about 12 percent to about 14 percent cobalt, from about 15 percent to about 17 percent chromium, from about 3.5 percent to about 4.5 percent molybdenum, from about 3.5 percent to about 4.5 percent tungsten, from about 1.5 percent to about 2.5 percent aluminum, from about 3.2 percent to about 4.2 titanium, from about 0.5 percent to about 1.0 percent niobium, from about 0.01 percent to about 0.04 percent boron, from about 0.01 percent to about 0.06 percent carbon, from about 0.01 percent to about 0.06 zirconium, up to about 0.01 percent vanadium, up to about 0.3 percent hafnium, up to about 0.01 percent yttrium, balance nickel and incidental impurities.

15. The method of claim 6, including an additional step, after the step of chemically reducing, of processing the coated powder particles to form the article, wherein the step of processing is performed without melting the powder particle substrates.

16. The method of claim 15, wherein the step of processing includes the step of consolidating the coated powder particles.

17. The method of claim 15, wherein the step of processing includes the step of heat treating the article.

18. The method of claim 15, wherein the step of processing includes the step of fully interdiffusing the surface-enriched layer with its respective powder particle substrate so that substantially no surface-enriched layer remains at the surface of the respective powder particle substrates.

19. The method of claim 15, wherein the step of processing includes the step of maintaining at least a portion of the surface-enriched layer at the surface of the respective powder particle substrates without fully interdiffusing the surface-enriched layer with the respective powder particle substrate.

20. A method of making an environmentally resistant gas turbine disk comprising the steps of: furnishing a plurality of powder particle substrates made of a superalloy substrate metal;providing a nonmetallic precursor of a metallic coating material, wherein the metallic coating material comprises an alloying element that is thermophysically melt incompatible with the superalloy substrate metal;contacting the powder particle substrates with the nonmetallic precursor;chemically reducing the nonmetallic precursor to form coated powder particles comprising the powder particle substrates having a surface-enriched layer of the metallic coating material thereon, wherein the step of chemically reducing is performed without melting the powder particle substrates; andprocessing the coated powder particles to form the gas turbine engine disk without melting the powder particle substrates, wherein the step of processing includes the step ofconsolidating the coated powder particles; andheat treating the gas turbine engine disk.