EP1794341A1

EP1794341A1 - Method for producing a layer system

Info

Publication number: EP1794341A1
Application number: EP05787327A
Authority: EP
Inventors: Georg Bostanjoglo; Nigel-Philip Cox; Rolf WILKENHÖNER
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2004-10-07
Filing date: 2005-09-01
Publication date: 2007-06-13
Also published as: WO2006040221A1; EP1794340A1; EP1645652A1; WO2006040220A1

Abstract

Prior art layer systems often have, due to their type of coating, only a low adherence to the substrate. The layer can detach in the instance of components that are subjected to high levels of mechanical stress. According to the inventive method for producing a layer system (1), an outer layer (9) is produced layer-by-layer together with anchoring means (10) passing completely therethough or with inner anchoring means (13).

Description

Method for producing a layer system

The invention relates to methods for producing a layer system according to the preamble of claim 1.

Components for high temperatures are usually provided with protective coatings today.

These may be metallic corrosion protection layers (MCrAlX layers) or ceramic thermal barrier layers as well as layer systems with metallic corrosion protection layers and / or ceramic thermal barrier coatings.

As a coating method for these coatings, plasma-assisted powder spraying processes are used because of their comparatively high cost-effectiveness.

The bonding of such layers to the substrate takes place by mechanical clamping and subsequent diffusion heat treatment. Occasionally, it can occur in highly loaded areas or unfavorable, i. Especially at mechanically high loaded points of the component to a detachment of the layer come in operation. The spalling of the layer during operation leads to damage to the base material, so that the component life is substantially reduced.

No. 5,869,798 discloses a method in which elevations are produced on a surface by means of a welding method, wherein the elevation consists of a different material than the underlying substrate.

EP 1 275 748 A2 discloses anchoring means disposed on a surface of the substrate or an intermediate layer.

DE 100 57 187 A1 discloses anchoring means which project into a substrate in order to improve the adhesion of a non-metallic material to the metallic substrate. EP 0 713 957 A1 discloses a method in which a depression in a layer is filled up with material.

Further prior art is known from DE 30 38 416 A1 as well as from the journal Journal of Materials Science 24 (1989), page 115-123 entitled "Enhanced metal-ceramic adhesion by sequential sputter deposition and pulsed laser melting of copper films on sapphire Substrates "by AJ Pedraza, MJ Godbole.

It is therefore an object of the invention to provide a process for the production of a layer system which results in a better bond between a protective layer and a substrate and / or of layers with one another.

The object is achieved by an inventive method for producing a layer system according to claim 1.

The layer system produced by the method according to the invention has separately produced anchoring means which have a very strong bond to the substrate or to a layer arranged underneath it on the substrate and in a different way than the layer to the substrate or the other layer are connected.

The stronger bonding of the anchoring means compared to the existing layer bonding (for example Ver¬ clamping by surface roughness), for example, by a melt-metallurgical bond, which is produced in a separate from the application of the actual layer material process. Thus, furthermore, the cost-effective and economical plasma spraying process can be used to apply the layer.

In the subclaims further advantageous Verfahrens¬ steps are listed. The measures listed in the dependent claims can be advantageously combined with each other in an advantageous manner.

1 shows a layer system according to the prior art,

2, 4 to 9 layer systems, FIG. 3 a perspective top view of a layer system, FIGS. 10 to 13 method steps of a method according to the invention, FIGS. 14 to 22 method steps of further methods according to the invention,

Figure 23, 24 process steps of a further inventive method.

FIG. 25 shows a gas turbine, FIG. 26 shows a combustion chamber and FIG. 27 shows a turbine blade.

FIG. 1 shows a layer system 1 'according to the prior art.

The layer system 1 ^f has a substrate 4. At least one outer layer 9 with an outer surface 16 is present on the substrate surface 5 of the substrate 4. This may be a metallic and / or ceramic outer layer 9.

The bonding of the outer layer 9 on the substrate 4 takes place according to the prior art solely by mechanical clamping (surface roughness) to the underlying surface and subsequent diffusion heat treatment.

FIG. 2 shows, starting from FIG. 1, a layer system 1 prepared by a method according to the invention. The substrate 4 may be metallic or ceramic and is in the case of gas turbine components, in particular made of an iron-, nickel- or cobalt-based superalloy.

For turbine blades 120, 130 (FIGS. 25, 27), for example, a metallic corrosion protection layer is applied to the substrate 4 as an intermediate layer 7 (FIGS. 5, 6, 7) of the MCrAlX type, whereupon an additional outer layer is additionally provided - For example, a ceramic thermal barrier coating 9 is applied.

Continuous anchoring means 10 or inner anchoring means 13 are present in the intermediate layer 7 and / or the outer layer 9 and extend into the substrate 4 or into the intermediate layer 7, for example with a certain proportion 14 of their volume or their length. In the following, a layer system 1 with an outer layer 9 is explained by way of example.

The proportion 14, that is to say an extent of the continuous anchoring agent 10 or of the inner anchoring means 13 into the substrate 4, represents the smaller proportion relative to the length of the continuous anchoring means 10 or the inner anchoring means 13, so that the continuous anchoring means 10 or the inner anchoring means 13 is located in the outer layer 9 with the largest proportion.

The continuous anchoring means 10 or the inner anchoring means 13 have, in particular, a different type of connection, in particular with an increased bonding force (more precisely: force / per contact surface), to the substrate 4 compared to the type of the outer layer 9 to the substrate 4th

The continuous anchoring means 10 or the inner Ver¬ anchoring means 13 are suitable for example by a guided laser welding process fusion metallurgically bonded to the substrate 4.

It is likewise conceivable for the outer layer 9 to be applied at specific points by laser cladding (laser powder coating) and thus to form continuous anchoring means 10 or inner anchoring means 13. The through-going anchoring means 10 or the inner anchoring means 13 can also be cast on or produced during the casting of the substrate 4. The continuous anchoring means 10 or the inner anchoring means 13 constitute adhesion bridges for the outer layer 9 surrounding the continuous anchoring means 10 or the inner anchoring means 13.

The continuous anchoring means 10 start from the substrate 4 or substrate surface 5 and in particular extend only to the outer surface 16 of the outer layer 9.

The continuous or inner anchoring means 10, 13 are, for example, of a columnar design and may also have a concave or convex curve (FIG. 7).

The anchoring means 10, 13 preferably extend in a direction which runs almost or completely perpendicular to the surface 5, 8.

The inner anchoring means 13 are covered by the outer layer 9, so that the inner anchoring means 13 do not extend to the outer surface 16 of the outer layer 19, that are arranged inside the outer layer 9 ending. They extend 13 to at least 10%, 20%, 30%, 40% or more of the thickness of the outer layer 9 in the outer layer. 9

The above statements apply analogously to an intermediate layer 7 to which an outer layer 9 is applied. The continuous anchoring means 10 or the inner anchoring means 13 are present, for example, only locally, ie locally limited (FIG. 3), on the substrate 4 or the intermediate layer 7, for example where the mechanical load is greatest.

This is, for example, the region of the leading edge 409 of a turbine blade 120, 130. The remaining blade would then have no continuous anchoring means 10 or inner anchoring means 13.

FIG. 3 shows a plan view of an inner surface 8 of an intermediate layer 7 or of an outer surface of an outer layer 9. The inner anchoring means are indicated by dashed lines

13, which do not extend to the inner surface 8 of the intermediate layer 7 or to the outer surface 16 of the outer layer. The continuous anchoring means 10 or the inner anchoring means 13 may have various geometries such as circles, stitching (i.e., they are elongate and intersecting), waveforms, parallel paths, and combinations thereof.

FIG. 6 shows a further layer system 1 produced by a method according to the invention.

The layer system 1 consists of a substrate 4, an intermediate layer 7 and an outer layer 9. The intermediate layer 7 is, for example, a metallic MCrAlX layer and the outer layer 9 is, for example, a ceramic thermal barrier coating 9 on the intermediate layer 7,

Continuous anchoring means 10 or inner anchoring means 13 are present both in the intermediate layer 7 and in the outer layer 9. However, the intermediate layer 7 does not have to have any continuous anchoring means 10 or inner anchoring means 13 in the sense of the present invention (FIG. 5). Likewise, the anchoring means may be present only in the intermediate layer 7 (FIG. 7).

In this case, some, but not necessarily all, continuous anchoring means 10 or inner anchoring means 13 in the intermediate layer 7 or the outer layer 9 may have a portion 14 which extends into the substrate 4 or into the intermediate layer 7.

The continuous anchoring means 10 or the inner anchoring means 13 in the intermediate layer 7 and / or the outer layer 9 may extend from the substrate surface 5 of the substrate 4 to the inner surface 8 of the intermediate layer 7 or from the inner surface 8 of FIG Intermediate layer 7 extend to the outer surface 16 of the outer layer 9, but not beyond, or are covered by the intermediate layer 7 or the outer layer 9, so that the inner anchoring means 13 is not up to Innen¬ surface 8 of the intermediate layers 7 or outer Surface 16 of the outer layer 9 extend.

The continuous anchoring means 10 or the inner anchoring means 13 in the intermediate layer 7 improve the bonding of the intermediate layer 7 to the substrate 4. The material of the continuous anchoring means 10 of the intermediate layer 7 can, for example, also be chosen such that an improved adhesion of the outer layer 9 on the continuous anchoring means 10 results (Fig. 7).

The material composition of the continuous anchoring means 10 or inner anchoring means 13 in the intermediate layers 7 or the outer layer 9 is suitably selected depending on the requirement. The material of the continuous anchoring means 10 or the inner anchoring means 13 corresponds for example to the material in which it is arranged for the most part. Thus, if the continuous anchoring means 10 or the inner anchoring means 13 is largely located in the intermediate layer 7, the material of the anchoring means 10, 13 corresponds to the material of the intermediate layer 7. If the continuous anchoring means 10 or the inner anchoring means 13 is largely in arranged the outer layer 9, the material of the respective Veran¬ kerungsmittels example corresponds to the material of the outer layer. 9

The continuous anchoring means 10 or the inner anchoring means 13 are present in particular in thermally and / or mechanically highly loaded areas.

For turbine blades 120, 130, for example, this is the leading edge 409, the trailing edge 412 or the transition between the blade leaf 406 and the platform 403.

The layer system 1 is for example a component of a gas 100 (also aircraft turbine) or steam turbine. Thermally highly loaded components of the turbines have such a layer system, such as e.g. Turbine blades 120, 130, Hitzeschild¬ elements 155 of a combustion chamber 110 and other Gehäus¬ parts that are along the flow path of a hot steam or hot gas.

The layer system 1 can be applied to a newly manufactured component and to components that are refurbished after use (refurbishment). In this case, the components are previously freed from degraded layers, cracks are repaired if necessary, and a renewed coating of the substrate 4 takes place. FIG. 7 shows a further exemplary embodiment of a layer system 1 produced by a method according to the invention.

In this layer system 1, the continuous anchoring means 10 or the inner anchoring means 13 are present only in the intermediate layer 7. On the intermediate layer 7, the outer layer 9 is present. A contact surface of the continuous anchoring means 10 on the inner surface 8 improves the adhesion of the outer layer 9 to a comparable contact surface with the intermediate layer 7. This is achieved, for example, in that the contact surfaces of the continuous anchoring means 10 form germinal points (aluminum oxide) on the inner surface 8 for example, epitaxial growth of an outer layer 9 on the intermediate layer 7 or a further intermediate layer of Alumi¬ niumoxid.

Even without an intermediate layer 7 (FIG. 4), an improved layer system 1 is achieved in that the continuous anchoring means 10 or the inner anchoring means 13 lead to improved bonding of the outer layer 9 to the substrate 4.

For example, some, but not necessarily all, continuous anchoring means 10 or inner anchoring means 13 extend into the substrate 4 with a portion 14.

FIG. 5 shows a further exemplary embodiment of a layer system 1 produced by a method according to the invention.

In this exemplary embodiment, the continuous anchoring means 10 or the inner anchoring means 13 are present only in the outer layer 9. For example, some, but not necessarily all, continuous anchoring means 10 or inner anchoring means 13 extend into the intermediate layer 7.

FIG. 4 shows a further layer system 1.

In a first step was on the substrate 4 in known

Way applied an outer layer 9.

The outer layer 9 is, for example, with a laser 17th

(Figure 14) or an electron beam gun 17 which emits a corresponding laser or electron beam 19 (Figure 14). As a result of this type of treatment, the material of the outer layer 9 as far as the substrate surface 5 of the substrate 4 or, for example, with a portion 14 into the substrate 4, is locally converted, for example melted, so that a molten metal alloy is formed Connection of the material of the outer layer 9 in the substrate 4 results. With this method, continuous anchoring means 10 are produced, which extend from the substrate surface 5 all the way to the outer surface 16 of the outer layer 9.

FIG. 9 shows a further exemplary embodiment of a component 1 (cross section through continuous anchoring means 10) produced by a method according to the invention. The continuous anchoring means 10 has a larger cross-sectional area at the outer surface 16 than at the lower substrate surface 5 (FIG. 8, top view of FIG. 9). The shape of the continuous anchoring means 10 in cross section is bell-shaped here. The cross-sectional contour may also have other shapes, such. B. a parabolic course, wherein the parabola can be open to the top 16 (FIG. 8) or 5 down. The cross section of the continuous anchoring means 10 is here, for example, round (FIG. 8). Dashed lines indicate the cross-sectional area of the continuous anchoring means 10 on the substrate surface 5 or in the substrate 4.

The continuous anchoring means 10 may also extend into the substrate 4 (not illustrated).

The above statements apply analogously to an intermediate layer 7, to which an outer layer 9 is applied.

For example, the material of the continuous anchoring means 10 in the intermediate layer 7 may correspond to the material of the substrate 4 or be ceramic, whereby the ceramic thermal barrier coating 9 better with the continuous anchoring means 10 extending to the inner surface 8 of the intermediate layer 7, can connect or the continuous anchoring means 10 serve as a growth nucleus, in particular during epitaxial growth, during the coating of the intermediate layer 7 with the ceramic material of the äuße¬ Ren layer. 9

FIGS. 10 to 13 show a method according to the invention for producing the layer system 1.

The outer layer 9 and the continuous anchoring means 10 or inner anchoring means 13 are produced, for example, in layers, ie the outer layer 9 is er¬ and then or simultaneously the Veran¬ kerkerungsmittel 10 or inner anchoring means 13. Keines¬ if first, the anchoring means at least mostly or completely produced and then the layer or vice versa. Thus, starting from the substrate 4, which does not yet have an outer layer 9 (FIG. 10), material for the outer layer 9 is layered in sublayers 9 ^f (FIG. 11), 9 ^ff (FIG. 12), 9 ^fff (FIG 13) are applied and also in layers the continuous anchoring means 10 are produced in anchoring medium layers 10 ', 10 ", 10' ^ff .

The inner anchoring means 13 can also be produced in layers (not shown).

Depending on whether continuous anchoring means 10 or inner anchoring means 13 are to be produced, at locations where a continuous anchoring means 10 or an inner anchoring means 13 is to be formed, the spot is heated and melted by means of a laser, for example. the temperature is increased temporarily and locally.

If an inner anchoring means 13 is to be produced (FIGS. 12, 13) which is not intended to extend as far as the outer surface 16 of the outer layer 9, the outer layer 9 ', 9 ^{ff is} no longer locally raised at a certain height ¬ molten (Figure 12).

The explanations regarding the outer layer 9 apply analogously for an intermediate layer 7, to which an outer layer 9 is applied or analogously for an outer layer 9 on an intermediate layer 7.

FIGS. 14 to 16 show a further method according to the invention.

Here, an outer layer 9 is already partially present on the substrate 4. This is the case, in particular, when it is a component 1 to be repaired, which was used, for example, and in particular has a local damage in the form of a depression 34. An area around this recess 34 is weakened, for example, or was exposed to increased requirements in use, so that the area was removed during or after use and the recess 34 was formed.

Then, in a first step, for example, by means of a laser 17 (or electron gun) and its laser beams 19, the material in the recess 34 is treated (Figure 14), so that continuous anchoring means 10 or inner anchoring means 13 form (Figure 15).

In a further method step (FIG. 16), the depression 34 is filled with layer material 25, for example by a material conveyor 22 (for example by laser welding), wherein either only layer material 25 is filled without the inner anchoring means 13 according to FIG is formed, so that an inner anchoring means 13 is formed, which does not extend to äuße¬ Ren surface 16 or example, the laser 17 for laser deposition welding is also used, for example, to grow the continuous anchoring means 10 of FIG 15 to the outer surface 16 , This results in the recess 34, a newly formed layer region 28th

The continuous anchoring means 10 or the inner Veran¬ kerungsmittel 13 may, but not necessarily with a proportion 14 (indicated by dashed lines) extend into the substrate 4 and have a shape according to Figure 8, 9.

The layer material 25 can be material of the outer layer 9 or of the substrate 4, but also have a different composition.

The statements apply analogously to an intermediate layer 7, to which an outer layer 9 is applied (FIGS. 17-19). Likewise, no intermediate layer 7 can be present locally in the depression 34, and layer material 25, for example, of the intermediate layer 7 is applied to the substrate surface 5 and continuous anchoring means 10 or inner anchoring means 13 are produced (FIGS. 20-22).

The newly formed layer region 28 can also form the continuous anchoring means 10 or the inner anchoring means 13, so that the continuous anchoring means

(10) or the inner anchoring means (13) of the recess 34 corresponds, so fills (Fig. 14 to 22).

FIGS. 23, 24 show further exemplary embodiments of a method according to the invention for producing a layer system

To produce the outer layer 9, for example, a plasma torch 31: APS, VPS, LPPS (FIG. 23) is used.

By means of a laser 17 and its laser beams 19, a continuous anchoring means 10 or inner anchoring means 13 is thereby simultaneously produced, for example by melting, in which at least temporarily at the locations predetermined for the continuous anchoring means 10 or the inner anchoring means 13 ¬ rial treated by means of the laser 17, that is, for example, is melted.

Likewise, two lasers 17, 17 '(FIG. 17) may be used, using a laser 17' for the application process, for example laser deposition welding with the aid of a material conveyor 22 (for example powder conveyor) which supplies the layer material 25, and a laser 17, which, as in FIG. 17, produces the continuous anchoring means 10 or the inner anchoring means 13. In FIGS. 14-24, the intermediate layers 7 or the outer layer 9 and the continuous anchoring means 10 or the inner anchoring means 13 can be produced in layers.

Instead of the lasers 17, 17 'or plasma torches 31, electron beam guns can also be used. The use of lasers, plasma torches is not limited to the embodiments on the continuous anchoring means 10 or the inner anchoring means 13, which extend with a proportion 14 in the substrate 4 or the intermediate layer 7 or on a special cross-sectional shape as shown in FIG. 9, 8.

The anchoring means as described above can also be used for multilayer systems with or without substrate, as they are preferably present in CMC materials. These ceramic CMC materials of fibers, especially carbon fibers, have many interlaminar layers. By the anchoring means between the respective layers, the strength of the layers can be improved with each other. The individual layers are virtually sewn together.

FIG. 25 shows a gas turbine 100 in a longitudinal section. The gas turbine 100 has inside a rotatably mounted about a rotation axis 102 rotor 103, which is also referred to as Turbi¬ nenläufer. Along the rotor 103, an intake housing 104, a compressor 105, a torus-like combustion chamber 110, in particular a ring combustion chamber 106, with a plurality of coaxially arranged burners 107, a turbine 108 and the exhaust gas housing 109 follow one another. The annular combustion chamber 106 communicates with, for example, a ring-shaped hot gas channel 111. There, for example, four form Turbine stages 112 connected in series form the turbine 108. Each turbine stage 112 is formed from two blade rings. As seen in the direction of flow of a working medium 113, in the hot gas channel 111 of a row of guide vanes 115, a series 125 formed of rotor blades 120 follows.

The guide vanes 130 are fastened to the stator 143, whereas the rotor blades 120 of a row 125 are attached to the rotor 103 by means of a turbine disk 133. Coupled to the rotor 103 is a generator or a work machine (not shown).

During operation of the gas turbine 100, air 105 is sucked in by the compressor 105 through the intake housing 104 and compressed. The compressed air provided on the turbine-side end of the compressor 105 is fed to the burners 107 and mixed there with a fuel. The mixture is then burned in the combustion chamber 110 to form the working medium 113. From there, the working medium 113 flows along the hot gas channel 111 past the guide vanes 130 and the rotor blades 120. The working medium 113 unwinds on the rotor blades 120 in a pulse-transmitting manner, so that the rotor blades 120 drive the rotor 103 and this drives the machine connected to it.

The components exposed to the hot working medium 113 are subject to thermal loads during the operation of the gas turbine 100. The guide vanes 130 and rotor blades 120 of the first turbine stage 112, viewed in the flow direction of the working medium 113, are subjected to the highest thermal load in addition to the heat shield bricks which line the annular combustion chamber 106. In order to withstand the temperatures prevailing there, they are cooled by means of a coolant. Likewise, the blades 120, 130 can have coatings against corrosion (MCrAlX, M = Fe, Co, Ni, X = Y, rare earths) and heat (thermal barrier coating, for example ZrC> 2, Y2O4-ZrO2). The guide blade 130 has a guide blade root facing the inner housing 138 of the turbine 108 (not illustrated here) and a guide blade head opposite the guide blade root. The vane head faces the rotor 103 and fixed to a mounting ring 140 of the stator 143.

FIG. 26 shows a combustion chamber 110 of a gas turbine 100. The combustion chamber 110 is designed, for example, as a so-called annular combustion chamber, in which a multiplicity of burners 107 arranged around the turbine shaft 103 in the circumferential direction open into a common combustion chamber space. For this purpose, the combustion chamber 110 in its entirety is configured as a ring-shaped structure which is positioned around the turbine shaft 103.

To achieve a comparatively high efficiency, the combustion chamber 110 is designed for a comparatively high temperature of the working medium M of about 1000 ° C to 1600 ° C. In order to allow a comparatively long service life for these operating parameters, which are unfavorable for the materials, the combustion chamber wall 153 is provided on its side facing the working medium M with an inner lining formed by heat shield elements 155. Each heat shield element 155 is equipped on the working medium side with a particularly heat-resistant protective layer or made of highly heat-resistant material. Due to the high temperatures inside the combustion chamber 110, a cooling system is additionally provided for the heat shield elements 155 or for their holding elements.

FIG. 27 shows a perspective view of a moving blade 120 or guide blade 130 of a turbomachine that extends along a longitudinal axis 121. The turbomachine may be a gas turbine of an aircraft or a power plant for generating electricity, a steam turbine or a compressor.

The blade 120, 130 has, along the longitudinal axis 121, a mounting area 400 adjacent to one another, a blade platform 403 adjacent thereto and an airfoil 406.

As a guide blade 130, the blade 130 may have an additional platform at its blade tip 415 (not shown).

In the mounting region 400, a blade root 183 is formed, which serves for attachment of the blades 120, 130 to a shaft or a disc (not shown).

The blade root 183 is designed, for example, as a hammer head. Other designs as Christmas tree or Schwal¬ benschwanzfuß are possible. The blade 120, 130 has a leading edge 409 and a discharge edge 412 for a medium that flows past the blade 406.

In conventional blades 120, 130, in all areas 400, 403, 406 of the blade 120, 130, for example, massive metallic materials, in particular superalloys, are used.

Such superalloys are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949; These documents are part of the disclosure regarding the chemical composition of the alloy.

The blade 120, 130 can hereby be produced by a casting process, also by directional solidification, by a forging process, by a milling process or combinations thereof.

Workpieces with a monocrystalline structure or structures wer¬ used as components for machines that are in operation high mechanical, thermal and / or chemical Belastun¬ conditions are exposed.

The production of such monocrystalline workpieces follows er¬ example. by directed solidification from the melt. These are casting processes in which the liquid metallic alloy is transformed into a monocrystalline structure, i. to the single-crystal workpiece, or directionally solidified. Here, dendritic crystals are aligned along the heat flow and form either a columnar grain structure (columnar, i.e. grains which run the full length of the workpiece and here, for general language use, are referred to as directionally solidified) or a monocrystalline structure, i. The entire workpiece is made of a single crystal. In these processes, it is necessary to avoid the transition to globulitic (polycrystalline) solidification since, due to undirected growth, it is necessary to form transverse and longitudinal grain boundaries which negate the good properties of the directionally solidified or monocrystalline component. If the term generally refers to directionally solidified structures, then it means both single crystals which have no grain boundaries or at most small-angle grain boundaries, and stem crystal structures which have grain boundaries which probably run in the longitudinal direction but have no transverse grain boundaries. In these second-mentioned crystalline

Structures are also known as directionally rigidified structures

(directionally solidified structures).

Such methods are known from US Pat. No. 6,024,792 and EP

0 892 090 Al known; These writings are part of the revelation.

Likewise, the blades 120, 130 may be coatings against corrosion or oxidation (MCrAlX; M is at least one element of the group iron (Fe), cobalt (Co), nickel (Ni), X is an active element and is yttrium (Y) and / or silicon and / or at least one element of the rare earths, or hafnium (Hf)). Such alloys are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1, which are to be part of this disclosure with regard to the chemical composition of the alloy.

On the MCrAlX may still be a thermal barrier layer and consists for example of ZrC> 2, Y2Ü4-Zrθ2, i. it is not, partially or completely stabilized by yttrium oxide and / or calcium oxide and / or magnesium oxide. By suitable coating methods, e.g. Electron beam evaporation (EB-PVD) produces stalk-shaped grains in the thermal barrier coating.

Refurbishment means that components 120, 130 may need to be stripped of protective layers after use (e.g., by sandblasting). This is followed by removal of the corrosion and / or oxidation layers or products. Optionally, even cracks in the component 120, 130 are repaired. This is followed by a re-coating of the component 120, 130 and a renewed use of the component 120, 130.

The blade 120, 130 may be hollow or solid. If the blade 120, 130 is to be cooled, it is hollow and may still have film cooling holes 418 (indicated by dashed lines).

Claims

claims

1. A method for producing a layer system (1), at least consisting of a substrate (4) and an outer layer (9), in particular with at least one intermediate layer (7), wherein the outer layer (9) or the intermediate layer (7) due a depression (34) is present at least partially on the substrate (4) or on the intermediate layer (7),

characterized,

that on the substrate (4) or in the intermediate layer (7) or in the outer layer (9) columnar, continuous anchoring means (10) or columnar, inner anchoring means (13) in the recess (34) are produced, and in the same or in a further process step, layer material (25) is applied at least into the depression (34) and a layer region (28) newly formed by the layer material (25) and / or columnar, continuous anchoring means (10) or columnar, inner columnar anchoring means (13) in the Vertie¬ tion (34) are generated.

2. A method for producing a layer system (1) according to claim 1, characterized in that

in that an apparatus (17) selected from the group including at least one laser or plasma torch, in particular a laser, is used to produce an intermediate layer (7) or an outer layer (9), in particular by laser deposition welding, and in that an apparatus (17 ') selected from the group including at least laser or plasma torch is used to column-like, continuous anchoring means (10) or columnar inner anchoring means (13) on the Sub¬ strat (4), in the intermediate layer (7) or in the outer

To produce layer (9).

3. The method according to claim 1 or 2, characterized

in that a plasma torch (31) or a laser (17 ') is used to produce the intermediate layer (7) or the outer layer (9), and that a laser (17) is used to provide the continuous anchoring during coating medium (10) or the inner anchoring means (13) to produce.

4. The method according to claim 1, 2 or 3, characterized in that

the continuous anchoring means (10) or the inner anchoring means (13) are produced by a laser welding process.

5. The method according to claim 1 or 2, characterized in that

the continuous anchoring means (10) or the inner anchoring means (13) are produced by electron irradiation.

6. The method of claim 1, 2, 3, 4 or 5, characterized in that

the continuous anchoring means (10) or the inner anchoring means (13) are produced in such a way that they have a fusion metallurgical connection to the substrate (4) or to the intermediate layer (7).

7. The method of claim 1, 2, 3, 4 or 5, characterized in that

the temperature in the intermediate layer (7) to be produced or in the outer layer (9) is increased temporarily and locally in order to produce the continuous anchoring means (10) or the inner anchoring means (13).

8. The method according to claim 2, characterized in that

as apparatus (17, 17 ') an electron beam gun is used.

9. The method according to claim 1 or 2, characterized in that

a layer system (1) with an intermediate layer (7), in particular of an alloy of the MCrAlX type, and a ceramic outer layer (9) is produced as the layer system.

10. The method according to claim 1 or 2, characterized in that

continuous anchoring means (10) or inner anchoring means (13) are produced in the intermediate layer (7) and the outer layer (9).

11. The method according to claim 1 or 2, characterized in that

only anchoring means (10) or inner anchoring means (13) which are continuous in the outer layer (9) are produced.

12. The method according to claim 1 or 2, characterized in that

only in the intermediate layer (7) continuous anchoring means (10) or inner anchoring means (13) are produced.

13. The method according to one or more of the preceding claims, characterized in that

a material of the intermediate layer (7), the outer layer (9) or the substrate (4) is used for the material of the continuous anchoring means (10) or the inner anchoring means (13).

14. The method according to one or more of the preceding claims, characterized in that

for the material of the continuous anchoring means (10) or the inner anchoring means (13), a material different from the material of the intermediate layer (7) or the outer layer (9) or the substrate (4) is used.

15. The method according to one or more of the preceding claims, characterized in that

the continuous anchoring means (10) or the inner anchoring means (13) are produced locally limited on the substrate (4) or the intermediate layer (7).

16. The method according to claim 1 or 2, characterized in that

the continuous anchoring means (10) are only produced up to an inner surface (8) of the intermediate layer (7) or only to the outer surface (16) of the outer layer (9).

17. The method according to claim 1 or 2, characterized in that

the inner anchoring means (13) are produced only within the intermediate layer (7) or the outer layer (9), in particular with a minimum thickness of at least 10% of the thickness of the intermediate layer (7) or the outer layer (9).

18. The method according to claim 1, characterized in that

by filling the depression (34), the anchoring means is formed such that the continuous anchoring means (10) or the inner anchoring means (13) fills the depression (34).

19. The method according to claim 1 or 2, characterized in that

the layer system (1) is a newly manufactured or rebuilt component of a gas (100) or steam turbine, in particular a turbine blade (120, 130), a heat shield element (155) or a housing part along the flow path a hot gas.

20. The method according to claim 1 or 2, characterized in that

the layer system (1) represents a multilayer system with or without a substrate (4).

21. The method according to claim 1, 2 or 20, characterized in that

the multilayer system (1) is a CMC material,

22. The method of claim 1, 2, 20 or 21, characterized in that

the anchoring means (10, 13) are present between interlaminar layers of the multilayer system.