Chromium and active elements modified platinum aluminide coatings

• US 20060046091A1
• Filed: 08/26/2004
• Published: 03/02/2006
• Est. Priority Date: 08/26/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Madhava, Murali, Reimer, George, Floyd, Margaret, Duffy, Timothy R.
• Granted Patent: US 7,229,701 B2
• Time in Patent Office: Days
• US Class Current: 428/689
• CPC Class Codes: C23C 10/58 more than one element being diffused in more than one step
• CPC Class Codes: C23C 14/16 on metallic substrates or on substrates of boron or silicon
• CPC Class Codes: C23C 14/246 Replenishment of source material
• 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 28/325 with layers graded in composition or in physical properties
• 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
• CPC Class Codes: F05D 2230/90 Coating; Surface treatment manufacture with deposition of material F05D2230/30
• CPC Class Codes: F05D 2300/611 Coating
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10T 428/12931 Co-, Fe-, or Ni-base components, alternative to each other
• CPC Class Codes: Y10T 428/12944 Ni-base component

Abstract

The present invention provides a chromium and active elements modified platinum aluminide coating that may be used on a surface of a gas turbine engine component such as a turbine blade. The coating may be used as a protective coating that impedes the progress of corrosion, oxidation, and sulfidation in superalloy materials that comprise the substrate of the turbine blade. Additionally, the coating may be used as a bond coat onto which a thermal barrier coating is deposited. The presence of active elements as well as chromium and platinum provides improved corrosion, oxidation, and sulfidation resistance. The coating is applied using an electron beam physical vapor deposition. The coating is applied alternatively using selected sequential diffusion processing steps involving chromium, platinum and aluminum.

Claims

1. A turbine blade surface coating having a weight composition comprising:

2. A turbine blade surface coating having a weight composition comprising:

about 20 to about 45% Ni, about 10% to about 20% Cr, about 15% to about 30% Al, about 15% to about 45% Pt, about 1.5% to about 6.0% Hf, and about 3.5% to about 4.5% Si.

3. The turbine blade surface coating according to claim 2 having a nominal weight composition comprising:

4. The turbine blade surface coating according to claim 2 having a nominal weight composition comprising:

5. The turbine blade surface coating according to claim 2 having a nominal weight composition comprising:

6. The turbine blade surface coating according to claim 2 having a nominal weight composition comprising:

7. A turbine blade comprising:

a superalloy substrate

a bond coating having a weight composition comprising;

Alabout 8 to about 30%Crabout 5 to about 30%Coabout 3 to about 10%Ptabout 15 to about 45%Hfabout 0.5 to about 8%Siabout 1 to about 6%Yabout 0.05 to about 0.5%Xabout 0 to about 5%Nibalance

wherein X comprises one or more of tantalum, rhenium, or zirconium.

8. The turbine blade according to claim 7 further comprising a thermal barrier coating on top of the bond coating.

9. The turbine blade according to claim 7 wherein the bond coating is deposited onto the substrate by an EBPVD process.

10. A turbine blade comprising:

a superalloy substrate

a bond coating having a weight composition comprising about 24 to about 32% Ni, about 10% to about 15% Cr, about 21% to about 24% Al, about 22% to about 40% Pt, about 1.5% to about 6.0% Hf, and about 3.5% to about 4.5% Si.

11. The turbine blade according to claim 10 wherein the bond coating consists essentially of an alloy having a weight composition of about 24 to about 32% Ni, about 10% to about 15% Cr, about 21% to about 24% Al, about 22% to about 40% Pt, about 1.5% to about 6.0% Hf, and about 3.5% to about 4.5% Si.

12. The turbine blade according to claim 10 further comprising a thermal barrier coating on top of the bond coating.

13. The turbine blade according to claim 10 wherein the bond coating is deposited onto the substrate by an EBPVD process.

14. A method of coating a turbine blade comprising the steps of:

loading an ingot of an alloy into an EBPVD feeder, wherein the alloy comprises

Alabout 8 to about 30%Crabout 5 to about 30%Coabout 3 to about 10%Ptabout 15 to about 45%Hfabout 0.5 to about 8%Siabout 1 to about 6%Yabout 0.05 to about 0.5%Xabout 0 to about 5%Nibalance

wherein X comprises one or more of tantalum, rhenium, or zirconium;

placing a turbine blade into an EBPVD vacuum chamber;

directing an electron beam from an electron gun onto the alloy ingot; and

directing an electron beam from an electron gun onto the turbine blade.

15. The method according to claim 14 further comprising the steps of:

preparing an alloy,

converting the alloy ingot form, and

cutting the ingot to desired lengths.

16. The method according to claim 14 further comprising the step of rotating the turbine blade.

17. The method according to claim 14 wherein the alloy comprises about 24 to about 32% Ni, about 10% to about 15% Cr, about 21% to about 24% Al, about 22% to about 40% Pt, about 1.5% to about 6.0% Hf, and about 3.5% to about 4.5% Si.

18. A method for providing a coating comprising the steps of:

forming an active elements modified chromium diffusion coating;

depositing noble metals to a thickness in the range of 3 to 12 microns;

performing a diffusion cycle in the temperature range of approximately 1800°

F. to 2000°

F. to form a Ni/Cr/Pt layer with or with-out active elements; and

performing an aluminizing step to generate coating microstructures.

19. The method according to claim 18 further comprising the step of performing a post coat diffusion treatment in the 1900°

F. to 2025°

F. temperature range.

20. The method according to claim 18 wherein the step of forming a diffusion coating is a chromium diffusion alone.

21. The method according to claim 18 wherein the step of depositing Noble metals comprises depositing a layer of platinum.

22. The method according to claim 18 wherein the step of depositing Noble metals further comprises depositing through the procedures of electroplating or PVD.

23. The method according to claim 18 wherein the step of performing an aluminizing steps comprises a Low Activity or Intermediate Activity or High Activity aluminizing step.

24. The method according to claim 18 wherein a multiphase additive layer containing a platinum, chromium, nickel aluminide LI phase is formed.

25. A method for providing a coating comprising the steps of:

depositing noble metals to a thickness in the range of 3 to 12 microns;

diffusing the Noble metals in the 1800 to 2000°

F. temperature range;

performing an active elements modified chromium diffusion coating;

performing a diffusion cycle in the temperature range of approximately 1800°

F. to 2000°

F. to form a Ni/Cr/Pt layer with or with-out active elements; and

performing an aluminizing step to generate coating microstructures.

26. The method according to claim 25 further comprising the step of performing a post coat diffusion treatment in the 1900°

F. to 2025°

F. temperature range.

27. The method according to claim 25 wherein the step of forming a diffusion coating is a chromium diffusion alone.

28. The method according to claim 25 wherein the step of depositing Noble metals comprises depositing a layer of platinum.

29. The method according to claim 25 wherein the step of depositing Noble metals further comprises depositing through the procedures of electroplating or PVD.

30. The method according to claim 25 wherein the step of performing an aluminizing steps comprises a Low Activity or Intermediate Activity or High Activity aluminizing step.