NIOBIUM SILICIDE-BASED TURBINE COMPONENTS, AND RELATED METHODS FOR LASER DEPOSITION

• US 20090280269A1
• Filed: 07/17/2009
• Published: 11/12/2009
• Est. Priority Date: 06/30/2005
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Azer, Magdi N., Bewlay, Bernard Patrick, Young, Craig Douglas, Cretegny, Laurent, Ritter, Ann Melinda
• Application Number:
  US12/504,976
• Publication Number:
  US 20090280269A1
• Time in Patent Office: Days
• US Class Current: 427/596
• CPC Class Codes: B22F 2207/01 Composition gradients
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 5/009 of turbine components other than turbine blades of turbine blades B22F5/04
• CPC Class Codes: B22F 5/04 of turbine blades
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23K 2103/08 Non-ferrous metals or alloys
• CPC Class Codes: B23K 2103/18 Dissimilar materials
• CPC Class Codes: B23K 2103/26 Alloys of Nickel and Cobalt and Chromium
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/144 the fluid stream containing particles, e.g. powder
• CPC Class Codes: B23K 26/32 taking account of the properties of the material involved
• CPC Class Codes: B23K 26/34 Laser welding for purposes other than joining
• CPC Class Codes: B23K 35/327 comprising refractory compounds, e.g. carbides
• CPC Class Codes: B23P 15/02 turbine or like blades from one piece
• CPC Class Codes: B23P 6/007 using only additive methods, e.g. build-up welding
• CPC Class Codes: C22C 27/02 Alloys based on vanadium, niobium, or tantalum
• CPC Class Codes: C22C 29/18 based on silicides
• CPC Class Codes: C23C 24/10 with intermediate formation of a liquid phase in the layer
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: F01D 5/28 Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
• CPC Class Codes: F01D 5/288 : Protective coatings for blades
• CPC Class Codes: F05D 2230/13 : using lasers
• CPC Class Codes: F05D 2230/31 : Layer deposition
• CPC Class Codes: F05D 2230/80 : Repairing, retrofitting or upgrading methods
• CPC Class Codes: F05D 2230/90 : Coating; Surface treatment manufacture with deposition of material F05D2230/30
• CPC Class Codes: F05D 2300/2261 : of silicon

Abstract

A turbine component formed from a niobium silicide-based composition is described. The component can be compositionally-graded through at least a portion of its structure. A turbine blade formed from a composition which includes a niobium silicide alloy is also described. The blade includes an airfoil; an airfoil tip region; a platform on which the airfoil is mounted; and a dovetail root attached to an underside of the platform. The niobium silicide alloy in at least one portion of the turbine blade is compositionally different from the niobium silicide alloy in another portion of the blade. Processes for fabricating a niobium silicide-based turbine article are also described, using laser cladding techniques. Repair methods are also set forth in the application.

Claims

1-28. -28. (canceled)

29. A process for fabricating a niobium silicide-based turbine article, wherein said article has a pre-selected shape and is characterized as a plurality of parallel cross-sections, each cross-section having a pre-selected pattern and thickness, comprising the steps of:

(i) melting a niobium silicide material with a laser beam, and depositing the molten material to form a first layer in the pattern of a first cross-section of the article, the thickness of the first deposited layer corresponding to the thickness of the first cross-section;

(ii) melting a niobium silicide material with a laser beam and depositing the molten material to form a second layer in the pattern of a second cross-section of the article, at least partially overlying the first layer of deposited material, the thickness of the second deposited layer corresponding to the thickness of the second cross-section; and

then

(iii) melting a niobium silicide material with a laser beam and depositing the molten material to form successive layers in patterns of corresponding cross-sections of the article, at least one of the successive cross-sections partially overlying the underlying cross-section, wherein the molten material is deposited and the successive layers are formed until the article is complete.

30. The process of claim 29, wherein at least one of the niobium silicide materials has a composition different from at least one other niobium silicide material used to form a cross-section of the article.

31. The process of claim 29, wherein, during each step of melting a niobium silicide material and depositing the molten material over a previously-deposited niobium silicide material to form successive layers, a portion of the previously-deposited material is melted, so as to form a welded bond between layers.

32. The process of claim 29, wherein each niobium silicide material to be melted is in the form of a powder.

33. The process of claim 29, wherein the niobium silicide material for each step is directed to a laser beam spot on a surface of the article being fabricated, through at least one delivery nozzle.

34. The process of claim 33, wherein the niobium silicide material is directed to the surface through multiple delivery nozzles which are spaced around the laser beam spot.

35. The process of claim 29, wherein the composition of at least some of the niobium silicide materials forming individual layers of the article is varied by changing the composition of a feed material which communicates with at least one delivery nozzle, said delivery nozzle directing the niobium silicide materials to the surface of the article being fabricated.

36. The process of claim 35, wherein the variation of the composition of the niobium silicide materials is carried out to provide compositional grading through at least a portion of the turbine article.

37. The process of claim 29, wherein the steps of melting the niobium silicide material and depositing the molten material in patterns of corresponding cross-sections of the article is controlled by at least one computer processor.

38. The process of claim 29, wherein the niobium silicide-based turbine article is selected from the group consisting of buckets, nozzles, rotors, disks, blades, vanes, stators, shrouds, combustors, blisks, and combinations thereof.

39. A method of repairing a turbine component formed of a material comprising a niobium silicide, and including a damaged segment, said method comprising the step of replacing or modifying the damaged segment with at least one replacement material comprising niobium silicide, using a laser cladding process.

40. The method of claim 39, wherein the turbine component is a blade.

41. A method of modifying a turbine component formed from a material comprising a niobium silicide, comprising the step of applying additional material which comprises a niobium silicide to at least a portion of the turbine component, according to a designated pattern, so that the turbine component is modified according to shape, composition, or a combination of shape and composition.

42. The method of claim 41, further comprising at least one machining or pressing step to modify the turbine component to a desired shape.