METHOD OF PRODUCING BLADES OR BLADE ARRANGEMENTS OF A TURBOMACHINE WITH EROSION PROTECTION LAYERS AND CORRESPONDINGLY PRODUCED COMPONENT

Abstract

The present invention relates to a method for producing a blade or blade arrangement of a turbomachine, which features the following steps: producing a blade (4) from at least one blade material, machining the blade in at least one region of the blade by a surface machining process, cleaning the surface of the blade depositing an erosion protection coating (10) of at least two layers of different hardness by physical vapor deposition in the at least one region, machining the erosion protection coating (10) by a coating smoothing process in order to establish a defined surface roughness.

Furthermore, the invention relates to correspondingly produced blades or blade arrangements.

Claims

1.-15. (canceled)

16. A method for producing a blade or blade arrangement of a turbomachine, wherein the method comprises subjecting a blade made of at least one blade material to a surface machining process in at least one region of the blade; cleaning the surface of the blade which has been subjected to the surface machining process in the at least one region; depositing on the at least one region of the blade which has been cleaned an erosion protection coating comprising at least two layers of different hardness by physical vapor deposition; machining the deposited erosion protection coating by a coating smoothing process.

17. The method of claim 16, wherein the blade is a part of a blisk.

18. The method of claim 16, wherein the at least one blade material is selected from one or more of titanium alloys, nickel alloys, steel, composite materials, ceramic-matrix composite materials.

19. The method of claim 16, wherein the surface machining process is selected from one or more of grinding, slide grinding, polishing, electropolishing, shot peening, shot blasting.

20. The method of claim 16, wherein the erosion protection coating comprises a sequence of layers which are selected from one or more of metal layers, metal alloy layers, ceramic layers, metal-ceramic layers, graded metal-ceramic layers.

21. The method of claim 20, wherein the sequence of layers has a total thickness of less than 50 μm and/or each layer of the sequence of layers has a thickness of from 0.2 μm to 10 μm.

22. The method of claim 20, wherein the sequence of layers comprises a layer which is nanostructured and deposited in a plurality of sub-layers.

23. The method of claim 22, wherein the plurality of sub-layers is a plurality of alternately repeating sub-layers of which an individual sub-layer has a thickness of from 10 nm to 200 nm.

24. The method of claim 20, wherein the layers of the sequence of layers comprise layers of one or more of chromium, chromium alloys, CrAlN, CrN.

25. The method of claim 16, wherein prior to deposition of the erosion protection coating a diffusion barrier layer and/or an adhesion promoting layer is deposited.

26. The method of claim 16, wherein the coating smoothing process comprises at least one of grinding, slide grinding, polishing, electropolishing.

27. The method of claim 16, wherein before or after the coating smoothing process, shot peening is carried out.

28. The method of claim 27, wherein the shot peening comprises shot blasting.

29. The method of claim 16, wherein after the machining of the blade by a surface machining process and prior to deposition of the erosion protection coating, a cutting of the blade to length and/or a deposition of a tip armor plating is carried out.

30. The method of claim 29, wherein the erosion protection coating is deposited over the tip armor plating.

31. The method of claim 16, wherein after the coating smoothing process one or more functional layers are applied.

32. The method of claim 16, wherein the erosion protection coating, in the case of partial application thereof, is deposited on the blade with decreasing layer thickness toward edges of the erosion protection coating and/or is deposited on a flow leading edge and/or flow trailing edge of the blade with a different layer thickness compared to that on a blade airfoil.

33. The method of claim 32, wherein the erosion protection coating is deposited on a flow leading edge and/or flow trailing edge of the blade with a thickness of from 20% to 200% of a layer thickness on the blade airfoil.

34. The method of claim 32, wherein the erosion protection coating is deposited on a flow leading edge and/or flow trailing edge of the blade with a continuous transition from the blade airfoil to the flow leading edge or trailing edge.

35. A blade or blade arrangement of a turbomachine, produced by the method of claim 16.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In the attached drawings, in a purely schematic manner

[0030] FIG. 1 shows a perspective view of a first exemplary embodiment of blades produced according to the invention in the form of a bladed disk (blisk),

[0031] FIG. 2 shows a perspective view of a second exemplary embodiment of a blade produced according to the invention, as can be used in turbomachines,

[0032] FIG. 3 shows a sectional view through the blade airfoil of the blade according to FIG. 2 and

[0033] FIG. 4 shows a sectional view through the coating construction of an erosion protection coating deposited according to the invention.

EXEMPLARY EMBODIMENTS

[0034] Further advantages, characteristics and features of the present invention become clear in the subsequent detailed description of exemplary embodiments. However, the invention is not limited to these exemplary embodiments.

[0035] FIG. 1 shows a perspective view of a so-called blisk 1 (blade integrated disk or integrally bladed rotor) which features a disk 2 and a multiplicity of blades 3 which are arranged integrally therein. The depicted blisk 1 is a single-row blisk 1 in which only one encompassing row of blades 3 is provided. However, blisk drums (not shown), in which a plurality of blade rows are provided next to each other on one or more integrally interconnected disks, can also be used. For example, such blisk drums can be created as a result of the axial welding of a plurality of blisks 1, as are shown in FIG. 1. Such blisk drums can also be produced by means of the method according to the invention.

[0036] FIG. 2 shows in a purely schematic manner a perspective view of a blade, as can be used in a turbomachine, such as a stationary gas turbine or an aviation engine. The blade 4 has a blade root 5 which can be installed in a disk which rotates with a shaft of the turbomachine. The blade furthermore has a blade airfoil 6 which is arranged in the flow passage of the turbomachine and either compresses the fluid which flows through the turbomachine or is driven by the fluid flowing past. Located at the radially outer end of the blade 4 is the so-called blade tip 7 which for avoiding flow losses butts as tightly as possible against an encompassing flow passage housing or even cuts into this. To this end, provision is made on the blade tip 7 for a blade-tip armor plating (see FIG. 3) which also has a cutting function so that the blade tip 7 can cut into an encompassing flow passage housing or sealing material which is arranged thereon. For example, the blade-tip armor plating can be formed by a coating with a nickel matrix with embedded cubic boron nitride particles.

[0037] For protection of the blade 4, the blade airfoil 6 also has a coating, specifically an erosion protection coating 10, which is intended to protect the material of the blade 4 against erosive wear. Such an erosion protection coating 10 can consist of a so-called multilayer coating or multiple layered coating, which can consist of a multiplicity of alternately deposited hard and soft layers, particularly ceramic layers and metal layers. The erosion protection coating 10 can be deposited in the main on the blade airfoil 6 and also on the leading edge 8 and the trailing edge 9 of the blade, but also on the blade tip 7, e.g. over a blade-tip armor plating (not shown).

[0038] It is to be gathered from FIG. 3 that the erosion protection coating can be deposited with different coating thickness on the blade 4 or on the blade airfoil 6. Therefore, for example the coating thickness D of the erosion protection coating 10 on the flow leading edge 8 can have up to 200% of the coating thickness d of the erosion protection coating 10 on the blade airfoil surface. Furthermore to be gathered from FIG. 3 is that the coating thickness of the erosion protection coating 10 can alter continuously so that there is no abrupt transition or an edge between the erosion protection coating 10 on the blade airfoil surface and the erosion protection coating 10 on the leading edge 8 or the trailing edge 9. In the embodiment of FIG. 3, the erosion protection coating 10 in cross section is arranged around the entire blade airfoil 6, wherein the erosion protection coating 10 can also be only partially applied to the blade airfoil 6, however, for example only on the pressure side and not on the suction side of the blade 4, wherein at the corresponding limits, on which the erosion protection coating 10 runs out, a correspondingly continuous transition can again be provided so that termination edges, which could lead to unfavorable stress ratios and to crack development, are dispensed with.

[0039] FIG. 4 shows a partial cross section through an erosion protection coating according to the invention, as for example can be applied to the blades 3 of the blisk 1 or to the blade airfoil 6 of the blade 4.

[0040] In the depicted exemplary embodiment of FIG. 4, an adhesion promoting layer 12, on which the actual erosion protection coating 10 is arranged, is first of all arranged on the base material 11 of the blade 3 or 4 which can be formed from a titanium alloy, a nickel alloy, steel, a composite material or a ceramic-matrix composite material or another suitable base material. The adhesion promoting layer 12 can be formed from a ceramic material, especially a gradient material which starting from the boundary surface on the base material 11 has an ever decreasing proportion of the base material. For example, the adhesion promoting layer 12 can be formed from graded CrN, wherein the CrN layer also serves at the same time as a diffusion barrier layer.

[0041] Two identical layer sequences 13 and 14 with the respective layers 16, 17, 18, 19, which in turn are separated from each other by a diffusion barrier layer 15, preferably consisting of CrN, are applied on top of the adhesion promoting layer or the diffusion barrier layer 12.

[0042] In the case of the individual layers of the layer sequences 13, 14 it is a metal layer 16, a metal alloy layer 17, a metal-ceramic gradient layer 18 and a nanostructured ceramic layer 19, which in turn are formed from a plurality of alternately provided ceramic sub-layers 21, 22.

[0043] The metal layer 16 is formed for example as a chromium layer in the depicted exemplary embodiment, whereas the metal alloy layer 17 is a Cr—Ni layer. In the case of the metal-ceramic gradient layer 18, it is a Cr.sub.xAl.sub.xN layer in the exemplary embodiment, whereas the nanostructured ceramic layer 19 consisting of ceramic sub-layers 21, 22 is formed from CrAlN and CrN.

[0044] In the case of the nanostructured ceramic layer 19, the sub-layers 21, 22 can be formed with layer thicknesses within the range of between 10 mm and 200 mm, whereas the layer thicknesses of the layers 16, 17, 18, 19 of the layer sequences 13, 14 can lie within the range of between 0.2 μm and 10 μm. The individual layers are deposited by means of physical vapor deposition (PVD) and especially by means of cathode evaporation (sputtering) or by means of cathodic arc deposition (CatArc).

[0045] After deposition of the layers, the uppermost layer is smoothed by means of grinding or polishing and the applied erosion protection coating 10 can he strengthened by shot blasting before or after the smoothing of the surface.

[0046] Although the present invention has been clearly described by the exemplary embodiments, it is self-evident that the invention is not limited to these exemplary embodiments but rather that modifications are possible in a way that individual features can be omitted or other types of combinations of features can be realized providing the extent of protection of the attached claims is not abandoned. The present disclosure includes all combinations of the presented individual features.

LIST OF REFERENCE NUMERALS

[0047] 1 Blisk [0048] 2 Disk [0049] 3 Blade [0050] 4 Blade [0051] 5 Blade root [0052] 6 Blade airfoil [0053] 7 Blade tip [0054] 8 Leading edge [0055] 9 Trailing edge [0056] 10 Erosion protection coating [0057] 11 Base material [0058] 12 Adhesion promoting layer or diffusion barrier layer [0059] 13 Layer sequence [0060] 14 Layer sequence [0061] 15 Diffusion barrier layer [0062] 16 Metal layer [0063] 17 Metal alloy layer [0064] 18 Metal-ceramic gradient layer [0065] 19 Nanostructured ceramic layer [0066] 21 Ceramic sub-layer [0067] 22 Ceramic sub-layer