BLADE FOR A TURBOMACHINE INCLUDING BLADE TIP ARMOR AND AN EROSION PROTECTION LAYER, AND METHOD FOR MANUFACTURING SAME

Abstract

blade for a turbomachine is provided. The blade at its blade tip (4) includes blade tip armor (5), and an erosion protection layer (11) above the blade tip armor. For the blade, the erosion protection layer in the area of the blade tip has a layer thickness in the range of 5 .Math.m to 100 .Math.m, in particular 10 .Math.m to 50 .Math.m.

Claims

1-10. (canceled)

11. A blade for a turbomachine, the blade comprising: a blade tip including blade tip armor, and an erosion protection layer above the blade tip armor, the erosion protection layer in the area of the blade tip has a layer thickness in the range of 5 .Math.m to 100 .Math.m.

12. The blade as recited in claim 11 wherein the layer thickness is in the range of 10 .Math.m to 50 .Math.m.

13. The blade as recited in claim 11 wherein the layer thickness is in the range of 15 .Math.m to 35 .Math.m.

14. The blade as recited in claim 11 wherein the blade includes an airfoil, the erosion protection layer, but no blade tip armor, being in the area of the airfoil.

15. The blade as recited in claim 11 wherein the blade tip armor includes a nickel layer with embedded hard material particles or an MCrAlY layer with embedded hard material particles, where M of the MCrAlY layer is a metal.

16. The blade as recited in claim 11 wherein the blade tip armor has the MCrAlY layer and M is in particular nickel, cobalt, or iron, and the embedded hard material particles include oxides or carbides or boron nitride.

17. The blade as recited in claim 16 wherein the embedded hard material particles include cubic boron nitride or aluminum oxide.

18. The blade as recited in claim 11 wherein the erosion protection layer includes at least one metal layer and a ceramic layer.

19. The blade as recited in claim 18 wherein the erosion protection layer includes multiple repeated, layer sequences of the metal layer and the ceramic layer, optionally with an additional a metal alloy layer or a metal-ceramic mixed layer.

20. The blade as recited in claim 18 wherein the metal layer of the erosion protection layer includes titanium, platinum, palladium, tungsten, chromium, nickel, or cobalt or a metal alloy layer includes at least one component that is selected from the group consisting of titanium, platinum, palladium, tungsten, chromium, nickel, cobalt, iron, aluminum, zirconium, hafnium, tantalum, magnesium, molybdenum, and silicon.

21. The blade as recited in claim 18 wherein a metal-ceramic mixed layer or the ceramic layer of the erosion protection layer include at least one oxide, nitride, carbide, or boride of at least one metal of the metal layer or of a metal alloy layer of the erosion protection layer.

22. The blade as recited in claim 11 wherein the blade includes a Cr-containing steel, a nickel-based superalloy, an iron-based superalloy, a titanium-based alloy, or a cobalt-based superalloy.

23. A method for manufacturing a blade of a turbomachine, the method comprising initially applying blade tip armor at the blade tip, and subsequently applying an erosion protection layer above the blade tip armor.

24. The method as recited in claim 23 wherein the application of the blade tip armor takes place via a process from the group including electroplating, soldering, applying a slip layer, physical and chemical vapor deposition, spraying, thermal spraying, and plasma-assisted spraying.

25. The method as recited in claim 23 wherein the erosion protection layer is deposited by physical vapor deposition.

26. The method as recited in claim 25 wherein the physical vapor deposition is a process selected from the group consisting of evaporation deposition, cathodic arc deposition, electron beam evaporation, atomization, and magnetron sputtering.

27. A method for manufacturing the blade as recited in claim 11, the method comprising initially applying the blade tip armor at the blade tip, and subsequently applying the erosion protection layer above the blade tip armor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The appended drawings show the following in a purely schematic manner:

[0022] FIG. 1 shows a perspective view of a blade, as may be used in turbomachines;

[0023] FIG. 2 shows a top view onto the blade tip of the blade according to FIG. 1; and

[0024] FIGS. 3a, 3b and 3c show a portion of a turbine blade in a sectional view according to various method steps of the method according to the present invention.

DETAILED DESCRIPTION

[0025] Further advantages, characteristics, and features of the present invention will become apparent in the following detailed description of the exemplary embodiments. However, the present invention is not limited to these exemplary embodiments.

[0026] FIG. 1 shows in a purely schematic manner a perspective view of a blade as may be used in a turbomachine, for example a stationary gas turbine or an aircraft engine. Blade 1 includes a blade root 2 which may be inserted into a disk that rotates together with a shaft of the turbomachine. Blade 1 also includes an airfoil 3 that is situated in the flow channel of the turbomachine, the airfoil either compressing the fluid flowing through the turbomachine or being driven by the fluid flowing past. A shroud 10 is situated between blade root 2 and airfoil 3. So-called blade tip 4, which for avoiding flow losses rests as closely as possible against a surrounding flow channel housing or even grinds into same, is situated at the radially outward end of blade 1. For this purpose, blade tip armor which also has a cutting function is provided at blade tip 4 (cf. FIG. 3), so that blade tip 4 may cut into a surrounding flow channel housing or into sealing material situated at same. For example, the blade tip armor may be formed by a coating with a nickel matrix 6 that includes embedded cubic boron nitride particles 7.

[0027] FIG. 2 shows in a purely schematic illustration a top view onto the blade from FIG. 1. It is apparent that blade tip 4 includes a blade tip surface that faces away from the blade root, and that in the shown example has a basic shape of a banana. According to the present invention, blade tip armor and an erosion protection layer are situated on the blade tip surface.

[0028] FIG. 3 a) through c) show the various stages during the manufacture of a blade 1 that includes blade tip armor 5 and an erosion protection layer 11 at blade tip 4.

[0029] FIG. 3a) shows a portion of a blade 1 together with airfoil 3 and blade tip 4.

[0030] According to FIG. 3b), blade tip armor 5, made up of a nickel matrix 6 and hard material particles 7 made of cubic boron nitride embedded therein, is applied to blade tip 4. The application of blade tip armor 5 takes place, for example, by electroplating nickel matrix 6 in which the cubic boron nitride particles are embedded. However, the blade tip armor may also be implemented in some other suitable manner.

[0031] After blade tip armor 5 is completed, erosion protection layer 11 is applied (cf. FIG. 3c )), hard material particles 7 that are embedded in blade tip armor 5 and protrude from blade tip armor 5 being incorporated into the erosion protection layer. Since erosion protection layer 11, having a thickness of 25 .Math.m, for example, is so thin that protruding hard material particles 7 cannot be completely accommodated in erosion protection layer 11, a portion of hard material particles 7 may protrude beyond erosion protection layer 11 in order to cut in, via the hard material particles, a groove for the labyrinth seal in the oppositely situated sealing material of the flow channel boundary.

[0032] Erosion protection layer 11 may be deposited by physical vapor deposition (PVD), in particular using various methods of vapor deposition or applying the corresponding partial layers of the multilayer erosion protection layer by atomization (sputtering).

[0033] Although the present invention has been described in detail with reference to the exemplary embodiments, it is naturally understood by those skilled in the art that the present invention is not limited to these exemplary embodiments; rather, modifications are possible in such a way that individual features may be omitted or other combinations of features may be implemented without departing from the scope of protection of the appended claims. In particular, the present disclosure encompasses all combinations of the individual features presented in the various exemplary embodiments, so that individual features that are described only in conjunction with one exemplary embodiment may also be used for other exemplary embodiments or combinations of individual features not explicitly described.

LIST OF REFERENCE NUMERALS

[0034] 1 blade [0035] 2 blade root [0036] 3 airfoil [0037] 4 blade tip [0038] 5 blade tip armor [0039] 6 Ni matrix [0040] 7 BN particles (hard material particles) [0041] 8 leading edge [0042] 9 trailing edge [0043] 10 shroud [0044] 11 erosion protection layer