(19)
(11)EP 2 024 607 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
15.10.2014 Bulletin 2014/42

(21)Application number: 06761985.8

(22)Date of filing:  08.06.2006
(51)International Patent Classification (IPC): 
F01D 5/28(2006.01)
(86)International application number:
PCT/EP2006/005470
(87)International publication number:
WO 2007/140805 (13.12.2007 Gazette  2007/50)

(54)

COATED TURBINE COMPONENT AND METHOD OF COATING A TURBINE COMPONENT

BESCHICHTETE TURBINENKOMPONENTE UND METHODE ZUR BESCHICHTUNG EINER SOLCHEN KOMPONENTE

COMPOSANTS DE TURBINE REVÊTUS ET PROCÉDÉ POUR REVÊTIR UN COMPOSANT DE TURBINE


(84)Designated Contracting States:
DE ES FR GB IT

(43)Date of publication of application:
18.02.2009 Bulletin 2009/08

(73)Proprietor: Siemens Aktiengesellschaft
80333 München (DE)

(72)Inventors:
  • BOX, Paul
    Washinborough, Lincolnshire LN4 1DJ (GB)
  • WHITEHURST, Mick
    Hayle, Cornwall TR27 4DL (GB)

(74)Representative: Maier, Daniel Oliver et al
Siemens AG Postfach 22 16 34
80506 München
80506 München (DE)


(56)References cited: : 
WO-A-2005/031038
US-B1- 6 270 318
DE-A1- 19 859 477
US-B1- 6 296 447
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The invention relates to turbine components and to methods of coating a turbine component.

    [0002] Components of gas turbines are operated in a highly aggressive environment which can cause damage to the component in service. The environmental damage may occur in various forms in the hot combustion gas environment, such as particle erosion, different types of corrosion and oxidation, and complex combinations of these damage modes. The rate of environmental damage can be reduced by the use of protective layers.

    [0003] For example it is known that chromium provides excellent protection against so called type I and type II hot corrosion. In this regard, diffusion coatings produced by the diffusion of chromium and aluminium into the alloy substrate have long been used to provide this protection. MCrAlY overlay coatings (where M is Ni or Co or a combination of the two) have been applied as an alternative to diffusion coatings at higher temperatures to protect against oxidation. Diffused chromium alone is known to provide excellent protection against relatively low temperature type II hot corrosion, and further to be strain tolerant.

    [0004] Recent developments have shown that it is favourable to provide different types of coatings on different parts of a component. The coatings are chosen such that they are especially adapted to the thermal and corrosive conditions being present on the parts of the component during use.

    [0005] US 6,296,447 B1 discloses a gas turbine component with a location-dependent protective coating. The component is a turbine blade with a root, a neck, a platform, and an airfoil extending from the platform, having an outer and an inner surface defining cooling passages therethrough. A first coating is provided on at least a portion of the platform, a second coating is provided on the outer surface of the airfoil and a third coating is provided on the inner surface of the airfoil. The first coating differs in its composition from the second coating and the second coating differs in its composition from the third coating.

    [0006] In DE 198 59 477 A1, a turbine blade is disclosed, which is covered in its root area with a wear-resistant layer. This protective layer is based on an alloy, for example CuAlTi or FeCrB.

    [0007] Another protective coating is known from WO 2005/031038 A1. This document describes the application of a wear-resistant layer, particularly an erosion-resistant layer on gas turbine components. The layer may comprise several individual layers, arranged on top of each other, which can be provided by dip-coating for example.

    [0008] In US 6,270,318 B1, a turbine blade is disclosed having a root, a neck, a platform and an airfoil. The platform and the neck area can be covered with a zirconium-oxide layer.

    [0009] However, the various types of environmental damage are still observed, often necessitating premature replacement or repair of components after service exposure. As a result there is a need for an improved approach to the protection of in particular gas turbine components such as turbine blades and vanes.

    [0010] Accordingly it is an object of the present invention to provide a turbine component with an improved heat and corrosion resistance and to provide a method of coating a turbine component.

    [0011] A first aspect of the invention provides a turbine component with a root, a neck, a platform and an airfoil having an outer surface and an inner surface defining cooling passages therethrough, wherein at least a first coating is provided on the root.

    [0012] According to one embodiment a second coating may be provided on the neck. In this case the composition of the first coating should be different from the second coating.

    [0013] Further it is possible to provide the second coating also on the outer surface of the airfoil and on at least a part of the platform and to provide additionally a third coating on the inner surface of the airfoil. In this case the first, second and third coating have different compositions.

    [0014] The first coating which can comprise Cr which can be diffused into the component applying known methods like pack cementation or chemical vapour deposition (CVD).

    [0015] Experiments have shown that good protection properties can be obtained if the first coating is a layer which is 5 to 25 µm thick and/or comprises 15 to 30 weight-% Cr.

    [0016] The second coating can comprise MCrAlY, wherein M can be Co or Ni or a combination of both. Further elements such as Re, Si, Hf and/or Y can be included in the coating.
    A preferred composition of the coating is 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y.
    Different thermal spray techniques such as vacuum plasma spraying (VPS), low pressure plasma spraying (LPPS), high velocity ox-fuel spraying (HVOF), cold gas spraying (CGS) or electroplating can be applied.

    [0017] The second coating can further have one of the following compositions:

    30 weight-% Ni, 28 weight-% Cr, 8 weight-% Al, 0.6 weight-% Y, 0.7 weight-% Si, Co balance;

    28 weight-% Ni, 24 weight-% Cr, 10 weight-% Al, 0.6 weight-% Y and Co balance;

    23 weight-% Cr, 10 weight-% Co, 12 weight-% Al, 0.6 weight-% Y, 3.0 weight-% Re, Ni balance;

    21 weight-% Cr, 12 weight-% Co, 11 weight-% Al, 0.4 weight-% Y and 2.0 weight-% Re, Ni balance;

    17 weight-% Cr, 25 weight-% Co, 10 weight-% Al, 0.4 weight-% Y and 1.5 weight-% Re, Ni balance.



    [0018] The third coating can comprise Cr and Al. Preferably the coating is a Al modified Cr coating which can be provided by diffusion of Al into a chromized surface applying known methods such as CVD and ATP. It was found that a composition of the third coating in an outer beta layer of between 15 to 30 weight-% Al and 5 to 15 weight-% Cr shows excellent protection properties.

    [0019] Alternatively, a second coating can be provided on the inner and on the outer surface of the airfoil and on at least a part of the platform, and a third coating may be provided on the neck. In this case the first, the second and the third coating are different in their compositions.

    [0020] The first coating, which may comprise Cr can be diffused into the component by known methods like pack cementation or chemical vapour deposition (CVD). Experiments have shown that good protection properties can be obtained if the first coating is a layer which is 5 to 25 µm thick and/or comprises 15 to 30 weight-% Cr.

    [0021] According to one embodiment the second coating can comprise Cr and Al. Preferably the coating is a Al modified Cr coating which can be provided by diffusion of Al into a chromized surface using known methods such as CVD and ATP. It was found that a composition of the third coating in an outer beta layer of between 15 to 30 weight-% Al and 5 to 15 weight-% Cr shows excellent protection properties.

    [0022] The third coating may comprise MCrAlY, wherein M can be Co or Ni or a combination of both. Further elements such as Re, Si, Hf and/or Y can be included in the coating. A preferred composition of the coating is 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y. Different thermal spray techniques such as vacuum plasma spraying (VPS), low pressure plasma spraying (LPPS), high velocity ox-fuel spraying (HVOF), cold gas spraying (CGS) or by electroplating can be applied.

    [0023] The third coating can further have one of the following compositions:

    30 weight-% Ni, 28 weight-% Cr, 8 weight-% Al, 0.6 weight-% Y, 0.7 weight-% Si, Co balance;

    28 weight-% Ni, 24 weight-% Cr, 10 weight-% Al, 0.6 weight-% Y and Co balance;

    23 weight-% Cr, 10 weight-% Co, 12 weight-% Al, 0.6 weight-% Y, 3.0 weight-% Re, Ni balance;

    21 weight-% Cr, 12 weight-% Co, 11 weight-% Al, 0.4 weight-% Y and 2.0 weight-% Re, Ni balance;

    17 weight-% Cr, 25 weight-% Co, 10 weight-% Al, 0.4 weight-% Y and 1.5 weight-% Re, Ni balance.



    [0024] Preferably the part of the platform to be coated is the top surface and/or the side face.

    [0025] According to a further embodiment of the first aspect the first coating can also be provided on the neck and on the inner surface of the airfoil.

    [0026] A second coating can be provided on the outer surface of the airfoil and on the top face and/or the side face of the platform, the first and the second coating being different in their composition.

    [0027] Also a third coating can be provided on top of the second coating on the outer surface of the airfoil and on the top face and/or the side face of the platform. In this case the first, the second and the third coating are different in their composition.

    [0028] The first coating, which may comprise Cr can be diffused into the component by known methods like pack cementation or chemical vapour deposition (CVD). Experiments have shown that good protection properties can be obtained if the first coating is a layer which is 5 to 25 µm thick and/or comprises 15 to 30 weight-% Cr.

    [0029] The second coating may comprise MCrAlY, wherein M can be Co or Ni or a combination of both. Further elements such as Re, Si, Hf and/or Y can be included in the coating. A preferred composition of the coating is 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y. Different thermal spray techniques such as vacuum plasma spraying (VPS), low pressure plasma spraying (LPPS), high velocity ox-fuel spraying (HVOF), cold gas spraying (CGS) or by electroplating can be applied.

    [0030] The second coating can further have one of the following compositions:

    30 weight-% Ni, 28 weight-% Cr, 8 weight-% Al, 0.6 weight-% Y, 0.7 weight-% Si, Co balance;

    28 weight-% Ni, 24 weight-% Cr, 10 weight-% Al, 0.6 weight-% Y and Co balance;

    23 weight-% Cr, 10 weight-% Co, 12 weight-% Al, 0.6 weight-% Y, 3.0 weight-% Re, Ni balance;

    21 weight-% Cr, 12 weight-% Co, 11 weight-% Al, 0.4 weight-% Y and 2.0 weight-% Re, Ni balance;

    17 weight-% Cr, 25 weight-% Co, 10 weight-% Al, 0.4 weight-% Y and 1.5 weight-% Re, Ni balance.



    [0031] Further the third coating can comprise Al. Preferably the coating is overaluminised using known methods such as CVD and ATP. Good protection properties were found if the outer surface of the second coating had an Al content of between 15 to 30 weight-%.

    [0032] Experiments have shown that good protection properties are achieved if none of the coatings comprises Pt.

    [0033] The turbine component can consist of a super alloy, e.g. MarM247, IN6203 or CMSX4 and it can be provided by conventional or directionally solidified casting techniques.

    [0034] According to one preferred embodiment the turbine component is a turbine blade.

    [0035] According to a second aspect the object is also solved by a turbine component with a root, a neck, a platform and an airfoil having an outer surface and an inner surface defining cooling passages therethrough, wherein the inner surface of the airfoil is provided with a first coating and the outer surface of the airfoil is provided with a second coating, the first an the second coating having different compositions.

    [0036] According to one embodiment of the second aspect the second coating is a MCrAlY overlay coating (M representing combinations of Ni, Co and/or Fe).

    [0037] The second coating can contain 10-40 weight-% Cr, 5-35 weight-% Al, 0-2 weight-% Y, 0-7 weight-% Si, 0-2 weight-% Hf, balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total. A composition of the second coating with 20-40 weight-% Cr, 5-20 weight-% Al, 0-1 weight-% Y, 0-2 weight-% Si, 0-1 weight-% Hf, balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total is also possible. Preferably the second coating contains 25-40 weight-% Cr, 5-15 weight-% Al, 0-0.8 weight-% Y, 0-0.5 weight-% Si, 0-0.4 weight-% Hf, balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total.

    [0038] According to a third aspect of the invention the above object is also solved by a turbine component with a root, a neck, a platform and an airfoil having an outer surface and an inner surface defining cooling passages therethrough, wherein neck is provided with a first coating.

    [0039] Further, according to a forth aspect the object is solved by a turbine component with a root, a neck, a platform and an airfoil having an outer surface and an inner surface defining cooling passages therethrough, wherein the neck is provided with a first coating and the bottom of the platform is provided with a second coatings, the first an the second coating having different compositions.

    [0040] Still further, according to a fifth aspect of the invention the object is solved by a turbine comprising a first stage of blades and vanes and a second stage of vanes and blades, wherein the blades of the first stage are turbine components according to any of the claims 2 to 16 and the blades of the second stage are turbine blade components according to any of the claims 17 to 31.

    [0041] Finally according to a sixth aspect of the invention this object is solved by a method of coating a turbine component, with a root, a neck, a platform and an airfoil having an outer surface and an inner surface defining cooling passages therethrough, which comprises the following steps. A first coating is applied on all outer and inner surfaces of the component. Then a second coating is applied on a first portion of the component which is already coated with the first coating. Finally a third coating is applied on a second portion of the coated component. The first, the second and the third coating have different compositions.

    [0042] In other words the main principle of the present method is to coat the component as a whole with a first coating and to then apply on selected portions of the component further coatings to improve the thermal resistance, corrosion resistance etc. in the respective portions of the component. In this way a component may be designed, which by the provision of the different coatings has properties that meet the requirements in use.

    [0043] It is also possible to mask certain parts of the component especially the parts which shall be coated afterwards with a MCrAlY coating prior to the application of the first coating using masking elements and techniques know in the art. In this case the masked parts of the component will not be coated with the first coating.

    [0044] According to one embodiment the first coating is diffused into the component. This diffusion may be achieved by any suitable method like pack cementation or chemical vapour deposition (CVD). It is in particular possible to diffuse Cr into the compound which is known to provide an excellent protection against hot corrosion. Experiments have shown that good protection properties can be obtained if the first coating is a layer which is 5 to 25 µm thick and/or comprises 15 to 30 weight-% Cr.

    [0045] Preferably, the selected regions are regions which are not subject to high physical stress in the subsequent use of the component. This restriction ensures, that those regions of the component that are subject to higher physical stress are coated with the chromium diffusion coating alone, which is strain tolerant, and that the strain tolerance of this coating is not degraded by the application of further coatings.

    [0046] In a preferred embodiment of the sixth aspect the first portion comprises the neck, the outer surface of the airfoil and at least a part of the platform and the second portion is the inner surface of the airfoil.

    [0047] The second coating may be an overlay coating, that can comprise MCrAlY, wherein M can be Co or Ni or a combination of both. Further elements such as Re, Si, Hf and/or Y can be included in the coating. A preferred composition of the coating is 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y. Different thermal spray techniques such as vacuum plasma spraying (VPS), low pressure plasma spraying (LPPS), high velocity ox-fuel spraying (HVOF), cold gas spraying (CGS) or electroplating can be applied.

    [0048] The second coating can also have one of the following compositions:

    30 weight-% Ni, 28 weight-% Cr, 8 weight-% Al, 0.6 weight-% Y, 0.7 weight-% Si, Co balance;

    28 weight-% Ni, 24 weight-% Cr, 10 weight-% Al, 0.6 weight-% Y and Co balance;

    23 weight-% Cr, 10 weight-% Co, 12 weight-% Al, 0.6 weight-% Y, 3.0 weight-% Re, Ni balance;

    21 weight-% Cr, 12 weight-% Co, 11 weight-% Al, 0.4 weight-% Y and 2.0 weight-% Re, Ni balance;

    17 weight-% Cr, 25 weight-% Co, 10 weight-% Al, 0.4 weight-% Y and 1.5 weight-% Re, Ni balance.



    [0049] According to a further embodiment it is possible to apply the second and/or third coating, which can comprise Al, by diffusion, e.g. by CVD or above the pack (ATP).

    [0050] In still another preferred embodiment of the sixth aspect the first portion comprises the inner and the outer surface of the airfoil and at least a part of the platform and the second portion comprises the neck of the component.

    [0051] As in the first preferred embodiment it is possible to diffuse the second coating, which can comprise Al, into the component by CVD or ATP.

    [0052] The third coating may comprise MCrAlY, wherein M can be Co or Ni or a combination of both. Further elements such as Re, Si, Hf and/or Y can be included in the coating. A preferred composition of the coating is 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y. Different thermal spray techniques such as vacuum plasma spraying (VPS), low pressure plasma spraying (LPPS), high velocity ox-fuel spraying (HVOF), cold gas spraying (CGS) or by electroplating can be applied.

    [0053] The third coating can also have one of the following compositions:

    30 weight-% Ni, 28 weight-% Cr, 8 weight-% Al, 0.6 weight-% Y, 0.7 weight-% Si, Co balance;

    28 weight-% Ni, 24 weight-% Cr, 10 weight-% Al, 0.6 weight-% Y and Co balance;

    23 weight-% Cr, 10 weight-% Co, 12 weight-% Al, 0.6 weight-% Y, 3.0 weight-% Re, Ni balance;

    21 weight-% Cr, 12 weight-% Co, 11 weight-% Al, 0.4 weight-% Y and 2.0 weight-% Re, Ni balance;

    17 weight-% Cr, 25 weight-% Co, 10 weight-% Al, 0.4 weight-% Y and 1.5 weight-% Re, Ni balance.



    [0054] Preferred parts of the platform to be coated are the top surface and/or the side face.

    [0055] Tests have shown that good protection results can be obtained, if the coatings do not comprise Pt.

    [0056] The method according to the invention can be used to coat turbine blades which may consist of a super alloy, e.g. MarM247, IN6203 or CMSX4.

    [0057] Preferably the turbine component is a turbine blade.

    [0058] The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

    Figure 1 is a perspective view of a turbine blade according to a first embodiment of the present invention,

    Figure 2 is a side view of the turbine blade shown in figure 1,

    Figure 3 is a longitudinal sectional view of the turbine blade shown in figure 2,

    Figure 4 is a cross sectional view taken along line IV-IV in figure 2,

    Figure 5 is schematic view of the turbine blade shown in figure 1,

    Figure 6 is a perspective view of a turbine blade according to a second embodiment of the present invention,

    Figure 7 is a side view of the turbine blade shown in figure 6,

    Figure 8 is a longitudinal sectional view of the turbine blade shown in figure 7 and

    Figure 9 is a cross sectional view taken along line IX-IX in figure 7, and

    Figure 10 is schematic view of the turbine blade shown in figure 6.

    Figure 11 is a perspective view of a turbine blade according to a third embodiment of the present invention,

    Figure 12 is a side view of the turbine blade shown in figure 11,

    Figure 13 is a longitudinal sectional view of the turbine blade shown in figure 12 and

    Figure 14 is a cross sectional view taken along line XIV-XIV in figure 12, and

    Figure 15 is schematic view of the turbine blade shown in figure 11.



    [0059] Figures 1 to 5 show a turbine blade 1 according to the invention having a root 2, a neck 3, a platform 4 and an airfoil 5 with an outer surface 6 and an inner surface 7.
    In this case the turbine blade 1 consists of the superalloy MarM247 and is provided by directionally solidified casting techniques.
    The root 2 is connected with the neck 3 which carries the platform 4.
    The airfoil 5 extends from the platform 4.
    Inside the airfoil 5 the inner surface 7 defines at least one cooling passage 8 which is depicted in figure 4.

    [0060] A first diffusion Cr coating is present on all outer and inner surfaces of the blade 1. It is about 5 to 25 µm thick and comprises of 15 to 30 weight-% Cr.

    [0061] A second MCrAlY coating is provided on top of the first coating in restricted parts of the blade 1 only, namely on the neck 3, the outer surface 6 of the airfoil 5 and on the whole of the platform 4.
    The coating has a composition of 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y.

    [0062] The second MCrAlY coating can also have the following composition:

    10 to 40 weight-% Cr, 5 to 35 weight-% Al, 0 to 2 weight-% Y, 0 to 7 weight-% Si, 0 to 2 weight-% Hf and balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total, preferably 20 to 40 weight-% Cr, 5 to 20 Al, 0 to 1 weight-% Y, 0 to 2 weight-% Si, 0 to 1 weight-% Hf and balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total, more preferably 25 to 40 weight-% Cr, 5 to 15 weight-% Al, 0 to 0.8 weight-% Y, 0 to 0.5 weight-% Si, 0 to 0.4 weight-% Hf and balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total.



    [0063] The border between the portion of the blade 1 which is provided with the second coating and the root 2 which does not carry the coating is indicated by the dotted line A.

    [0064] A third coating covers the first coating on the inner surface 7. The third coating is a Al modified Cr coating which has in an outer beta layer a composition of 15 to 30 weight-% Al and 5 to 15 weight-% Cr.

    [0065] The distribution of the three different coatings on the blade 1 is also indicated in figure 5. A dotted line represent the first, a dashed line (short dash) the second and a dashed line (long dash) the third coating.

    [0066] In order to produce the coated turbine blade 1 in a first step all outer and inner surfaces of the blade 1 are diffusion coated with Cr by chemical vapour deposition.

    [0067] It is also possible to mask certain parts of the component especially the parts which shall be coated afterwards with a MCrAlY coating prior to the application of the first coating using masking elements and techniques already know in the art. In this case the masked parts of the component will not be coated with the first coating.

    [0068] In a second step MCrAlY as the second coating is applied to the neck 3, the outer surface 6 of the airfoil 5 and on the whole of the platform 4 to cover the first coating by high velocity ox-fuel spraying. Other thermal spraying techniques are also possible. It is important to use suitable masking elements to prevent stray deposition on parts of the blade 1 which shall not be coated with the second coating.

    [0069] Finally the third coating in the form of the Al modified Cr coating is applied. For this purpose Al is diffused by chemical vapour deposition into the already chromized (the first coating) inner surface 7 of the airfoil 5. This yields the outer beta layer of the desired composition.

    [0070] Figures 6 to 10 show another turbine blade 1 according to the invention also having a root 2, a neck 3, a platform 4 and an airfoil 5 with an outer surface 6 and an inner surface 7. In this case the turbine blade 1 consists of the superalloy IN6203 and is provided by conventional casting techniques.

    [0071] A first diffusion Cr coating is present on all outer and inner surfaces of the blade 1. It is between 5 to 25 µm thick and comprises of 15 to 30 weight-% Cr.

    [0072] A second coating is provided on top of the first coating in selected regions, namely on the outer and the inner surface (6,7) of the airfoil 5 and on the whole of the platform 4. The second coating is a Al modified Cr coating which has an outer beta layer with a composition of 15 to 30 weight-% Al and 5 to 15 weight-% Cr. The border between the portion of the blade 1 which is provided with the second coating and the neck 3 which does not have the second coating is indicated by the dotted line B.

    [0073] A third coating comprising MCrAlY covers the first coating on the neck 3 between line B and the root 2, the border being indicated by dotted line C. The third coating has the following composition: 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y.

    [0074] The third MCrAlY coating can also have the following composition: 10 to 40 weight-% Cr, 5 to 35 Al, 0 to 2 weight-% Y, 0 to 7 weight-% Si, 0 to 2 Hf and balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total, preferably 20 to 40 weight-% Cr, 5 to 20 Al, 0 to 1 weight-% Y, 0 to 2 weight-% Si, 0 to 1 Hf and balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total, more preferably 25 to 40 weight-% Cr, 5 to 15 Al, 0 to 0.8 weight-% Y, 0 to 0.5 weight-% Si, 0 to 0.4 Hf and balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total.

    [0075] The distribution of the three different coatings on the blade 1 is also indicated in figure 10. A dotted line represent the first, a dashed line (long dash) the second and a dashed line (short dash) the third coating.

    [0076] In order to produce the coated turbine blade 1 in a first step all outer and inner surfaces of the blade 1 are diffusion coated with Cr by pack cementation.

    [0077] It is also possible to mask certain parts of the component especially the parts which shall be coated afterwards with a MCrAlY coating prior to the application of the first coating using masking elements and techniques already know in the art. In this case the masked parts of the component will not be coated with the first coating.

    [0078] In a second step the second coating in the form of the Al modified Cr coating is prepared by diffusing Al into the already chromized (the first coating) outer and inner surface 6,7 of the airfoil 5 and the whole of the platform. This yields the outer beta layer of the desired composition.

    [0079] Finally the MCrAlY as the third coating is applied to the first coating on the neck 3 by vacuum plasma spraying. It is important to use suitable masking elements to prevent stray deposition on parts of the blade 1 which shall not be coated with the third coating.

    [0080] Figures 11 to 15 show a third turbine blade 1 according to the invention having a root 2, a neck 3, a platform 4 and an airfoil 5 with an outer surface 6 and an inner surface 7. In this case the turbine blade 1 consists of the superalloy CMSX4 and is provided by directionally solidified casting techniques. The root 2 is connected with the neck 3 which carries the platform 4. The airfoil 5 extends from the platform 4. Inside the airfoil 5 the inner surface 7 defines at least one cooling passage 8 which is depicted in figure 4.

    [0081] A first diffusion Cr coating is present on the root 2, the neck 3 and on the inner surface 7 of the airfoil 5. It is about 5 to 25 µm thick and comprises of 15 to 30 weight-% Cr.

    [0082] A second MCrAlY coating is provided in restricted parts of the blade 1 only, namely on the outer surface 6 of the airfoil 5 and on the top face and the side of the platform 4. The coating has a composition of 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y.

    [0083] The second MCrAlY coating can also have the following composition: 10 to 40 weight-% Cr, 5 to 35 Al, 0 to 2 weight-% Y, 0 to 7 weight-% Si, 0 to 2 Hf and balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total, preferably 20 to 40 weight-% Cr, 5 to 20 Al, 0 to 1 weight-% Y, 0 to 2 weight-% Si, 0 to 1 Hf and balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total, more preferably 25 to 40 weight-% Cr, 5 to 15 Al, 0 to 0.8 weight-% Y, 0 to 0.5 weight-% Si, 0 to 0.4 Hf and balance primarily Ni and/or Co with all other elemental additions comprising <20 weight-% of the total.

    [0084] The border between the portion of the blade 1 which is provided with the second coating and the portions of the platform 4 which do not carry the coating is indicated by the dotted line D.

    [0085] A third coating covers the second coating completely. It is provided on the outer surface 7 of the airfoil 5 and on the top face and the side face of the platform 4. The third coating comprises Al which was overaluminised. The second coating has in its outer surface a content of between 15 to 30 weight-% Al.

    [0086] The distribution of the three different coatings on the blade 1 is also indicated in figure 15. A dotted line represent the first, a dashed line (short dash) the second and a dashed line (long dash) the third coating.

    [0087] In order to produce the coated turbine blade 1 in a first step the inner surface 7 of the airfoil 5, the neck 3 and the root 2 of the blade 1 are diffusion coated with Cr by chemical vapour deposition. The other parts of the blade 1 are protected from being coated by suitable masking elements.

    [0088] In a second step MCrAlY as the second coating is applied to the outer surface 6 of the airfoil 5 and on the top face and/or the side face of the platform 4 by high velocity ox-fuel spraying. Other thermal spraying techniques are also possible. It is important to use suitable masking elements to prevent stray deposition on parts of the blade 1 which shall not be coated with the second coating.

    [0089] Finally the third coating is applied on top of the second coating. For this purpose Al is overaluminised by chemical vapour on the outer surface 6 of the airfoil 5 and on the top face and/or the side face of the platform 4. This yields the outer surface of the second surface with an Al content of between 15 to 30 weight-%.

    [0090] It is to be noted, that in the two described embodiments the turbine blades 1 are provided with the second and third coatings only in selected regions, whereas the reminder of the blade 1 is coated with a chromium diffusion coating alone which is strain tolerant, and that the strain tolerance of this coating is not degraded by the application of the second and third coatings.


    Claims

    1. Turbine component (1) with
    a root (2),
    a neck (3),
    a platform (4) and
    an airfoil (5)
    with an outer surface (6) and an inner surface (7) defining cooling passages (8) therethrough,
    wherein at least a first coating is provided on the root (2) and wherein a second coating is provided on the neck (3),
    the composition of the first coating differing from the second coating.
     
    2. Turbine component (1) according to claim 1,
    wherein a third coating is provided on the inner surface (7) of the airfoil (5),
    the first, the second and the third coating being different in their composition.
     
    3. Turbine component (1) according to claim 1 or 2,
    wherein the second coating also is provided on the outer surface (6) of the airfoil (5) and on at least a part of the platform (4).
     
    4. Turbine component (1) according to any of the claims 1 to 2,
    wherein the first coating comprises Cr.
     
    5. Turbine component (1) according to claim 4,
    wherein the Cr of the first coating is diffused into the component (1),
    especially only Cr is diffused.
     
    6. Turbine component (1) according to claim 5,
    wherein the Cr of the first coating is diffused by pack cementation or by chemical vapour deposition (CVD).
     
    7. Turbine component (1) according to any of the claims 4 to 6,
    wherein the first coating is a layer comprising 15 to 30 weight-% Cr and/or
    being 5 to 25 µm thick.
     
    8. Turbine component (1) according to any of the claims 1 to 7,
    wherein the second coating comprises MCrAlY,
    M being Co or Ni or both,
    especially the second coating consists of MCrAlY.
     
    9. Turbine component (1) according to claim 8,
    wherein the second coating further comprises Re, Si, Hf and/or Y
    especially Y.
     
    10. Turbine component (1) according to claim 8 or 9, wherein the second coating has a composition of
    30 to 70 weight-% Ni,
    30 to 50 weight-% Co,
    15 to 25 weight-% Cr,
    5 to 15 weight-% Al and
    up to 1 weight-% Y.
     
    11. Turbine component (1) according to any of the claims 1, 2, 3, 8 to 10,
    wherein the second coating is applied by thermal spray techniques such as a vacuum plasma spraying (VPS), low pressure plasma spraying (LPPS), high velocity ox-fuel spraying (HVOF), cold gas spraying (CGS) or by electroplating.
     
    12. Turbine component (1) according to any of the claims 2 to 11,
    wherein the third coating comprises Cr and Al.
     
    13. Turbine component (1) according to claim 12,
    wherein the third coating is a Al modified Cr coating, especially only Al and Cr are used for diffusing.
     
    14. Turbine component (1) according to claim 13,
    wherein the third coating is provided by diffusing Al into a chromized surface.
     
    15. Turbine component (1) according to claim 14,
    wherein the Al is diffused into the chromized surface by CVD or other methods such as above the pack (ATP).
     
    16. Turbine component (1) according to any of the claims 12 to 15,
    wherein the third coating has a composition in an outer beta layer of between 15 to 30 weight-% Al and 5 to 15 weight-% Cr.
     
    17. Turbine component (1) according to claim 1,
    wherein the second coating is provided on the inner (7) and on the outer surface (6) of the airfoil (5) and on at least a part of the platform (4).
     
    18. Turbine component (1) according to claim 17,
    wherein and a third coating is provided on the neck (3), the first, the second and the third coating differing in their composition.
     
    19. Turbine component (1) according to claim 17 or claim 18,
    wherein the first coating comprises Cr.
     
    20. Turbine component (1) according to claim 19, wherein the Cr of the first coating is diffused into the component (1),
    especially only Cr is diffused.
     
    21. Turbine component (1) according to claim 20,
    wherein the Cr of the first coating is diffused by pack cementation or CVD.
     
    22. Turbine component (1) according to any of the claims 17 to 21,
    wherein the first coating is a layer comprising 15 to 30 weight-% Cr and/or
    being 5 to 25 µm thick.
     
    23. Turbine component (1) according to any of the claims 17 to 22,
    wherein the second coating comprises Cr and Al.
     
    24. Turbine component (1) according to claim 23,
    wherein the second coating is a Al modified Cr coating.
     
    25. Turbine component (1) according to claim 24, wherein the second coating is provided by diffusing Al into a chromized surface,
    especially only Al and Cr are used for diffusing.
     
    26. Turbine component (1) according to claim 25,
    wherein the Al is diffused into the chromized surface by CVD or other methods such as ATP.
     
    27. Turbine component (1) according to any of the claims 23 to 26,
    wherein the second coating has a composition in an outer beta layer of between 15 to 30 weight-% Al and 5 to 15 weight-% Cr.
     
    28. Turbine component (1) according to any of the claims 18 to 27,
    wherein the third coating comprises MCrAlY, M being Co or Ni or both,
    especially the third coating consists of MCrAlY.
     
    29. Turbine component (1) according to claim 28,
    wherein the third coating further comprises Re, Si, Hf and/or Y
    especially Y.
     
    30. Turbine component (1) according to claim 18 or 29, wherein the third coating has a composition of
    30 to 70 weight-% Ni,
    30 to 50 weight-% Co,
    15 to 25 weight-% Cr,
    5 to 15 weight-% Al and
    up to 1 weight-% Y.
     
    31. Turbine component (1) according to any of the claims 18, 28 to 30,
    wherein the third coating is applied by thermal spray techniques such as VPS, LPPS, HVOF, CGS or by electroplating.
     
    32. Turbine component (1) according to any of the claims 3 to 31,
    wherein the part of the platform (4) to be coated is the top surface and/or the side face of the platform (4).
     
    33. Turbine component (1) according to claim 1,
    wherein the first coating is provided also on the inner surface (7) of the airfoil (5).
     
    34. Turbine component (1) according to claim 33, wherein
    a second coating is provided on the outer surface (6) of the airfoil (5) and
    on the top face and/or
    on the side face of the platform (4),
    the first and the second coating differing in their composition.
     
    35. Turbine component (1) according to claim 33,
    wherein a third coating is provided on top of the second coating on the outer surface (6) of the airfoil (5) and on the top face and/or
    the side face of the platform (4),
    the first, the second and the third coating differing in their composition.
     
    36. Turbine component (1) according to any of the claims 33 to 35,
    wherein the first coating comprises Cr.
     
    37. Turbine component (1) according to claim 36,
    wherein the Cr of the first coating is diffused into the component (1),
    especially only Cr is diffused.
     
    38. Turbine component (1) according to claim 37,
    wherein the Cr of the first coating is diffused by pack cementation or by chemical vapour deposition (CVD).
     
    39. Turbine component (1) according to any of the claims 36 to 38,
    wherein the first coating is a layer comprising 15 to 30 weight-% Cr and/or
    being 5 to 25 µm thick.
     
    40. Turbine component (1) according to any of the claims 33 to 39,
    wherein the second coating comprises MCrAlY,
    M being Co or Ni or both,
    especially the second coating consists of MCrAlY.
     
    41. Turbine component (1) according to claim 40,
    wherein the third coating further comprises Re, Si, Hf and/or Y,
    especially Y.
     
    42. Turbine component (1) according to claim 34 or 41, wherein the second coating has a composition of
    30 to 70 weight-% Ni,
    30 to 50 weight-% Co,
    15 to 25 weight-% Cr,
    5 to 15 weight-% Al and
    up to 1 weight-% Y.
     
    43. Turbine component (1) according to any of the claims 35, 40 to 42,
    wherein the third coating is applied by thermal spray techniques such as VPS, LPPS, HVOF, CGS or by electroplating.
     
    44. Turbine component (1) according to any of the claims 35 to 43,
    wherein the third coating comprises Al.
     
    45. Turbine component (1) according to claim 44,
    wherein the third coating is overaluminised.
     
    46. Turbine component (1) according to claim 45,
    wherein the Al of the third coating is overaluminised by pack cementation or by chemical vapour deposition (CVD).
     
    47. Turbine component (1) according to claim 46,
    wherein the outer surface of the second coating has an Al content of between 15 to 30 weight-%.
     
    48. Turbine component (1) according to any of the claims 1 to 47,
    wherein none of the coatings comprises Pt.
     
    49. Turbine component (1) according to any of the claims 1 to 48,
    wherein the turbine component (1) consists of a superalloy, e.g. MarM247, IN6203 or CMSX4.
     
    50. Turbine component (1) according to claim 49,
    wherein the turbine component (1) is provided by conventional or directionally solidified casting techniques.
     
    51. Turbine component (1) according to any of the claims 1 to 50,
    wherein the turbine component (1) is a turbine blade.
     
    52. Turbine comprising a first stage of blades and vanes and a second stage of blades and vanes,
    wherein the blades of the first stage are turbine components (1) according to any of the claims 1 to 16 or 32 and
    the blades of the second stage are turbine blade components (1) according to any of the claims 17 to 32.
     
    53. A method of coating a turbine component (1),
    having a root (2),
    a neck (3),
    a platform (4) and
    an airfoil (5) with an outer (6) and an inner surface (7), defining cooling passages (8) therethrough, comprising the steps:

    - applying a first coating on all outer and inner surfaces of the component (1);

    - applying a second coating on a first portion of the coated component (1), wherein the first portion comprises the neck (3);

    - applying a third coating on a second portion of the coated component (1),

    wherein the first, the second and the third coating have different compositions.
     
    54. A method according to claim 53,
    wherein the first coating is diffused into the component (1).
     
    55. A method according to claim 54,
    wherein the first coating is diffused by pack cementation or by chemical vapour deposition (CVD).
     
    56. A method according to claim 55,
    wherein the first coating comprises Cr.
     
    57. A method according to any of the claims 53 to 56,
    wherein the first coating is a layer comprising 15 to 30 weight-% Cr and/or being 5 to 25 µm thick.
     
    58. A method according to claim any of the claims 53 to 57,
    wherein the first portion further comprises the outer surface (6) of the airfoil (5) and at least a part of the platform (4) and wherein the second portion comprises the inner surface (7) of the airfoil (5).
     
    59. A method according to claim 58,
    wherein the second coating comprises MCrAlY, M being Co or Ni or both.
     
    60. A method according to claim 59,
    wherein the second coating further comprises Re, Si, Hf and/or Y.
     
    61. A method according to claim 60,
    wherein the second coating has a composition of 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y.
     
    62. A method according to any of the claims 59 to 61,
    wherein the second coating is applied by thermal spray techniques such as vacuum plasma spraying (VPS), low pressure plasma spraying (LPPS), high velocity ox-fuel spraying (HVOF), cold gas spraying (CGS) or by electroplating.
     
    63. A method according to any of the claims 53 to 62,
    wherein the third coating is applied by diffusion.
     
    64. A method according to claim 63,
    wherein the third coating comprises Al.
     
    65. A method according to claim 64,
    wherein the Al is diffused by CVD or other methods such as above the pack (ATP).
     
    66. A method according to claim any of the claims 53 to 57,
    wherein the first portion further comprises the inner (7) and the outer surface (6) of the airfoil (5) and at least a part of the platform (4) and wherein the second portion comprises the neck (3).
     
    67. A method according to claim 66,
    wherein the second coating is applied by diffusion.
     
    68. A method according to claim 67,
    wherein the second coating comprises Al.
     
    69. A method according to claim 68,
    wherein the second coating is diffused by CVD or other methods such as ATP.
     
    70. Method according to any of the claims 66 to 69,
    wherein the third coating comprises MCrAlY, M being Co or Ni or both.
     
    71. A method according to claim 70,
    wherein the third coating further comprises Re, Si, Hf and/or Y.
     
    72. A method according to claim 71,
    wherein the third coating has a composition of 30 to 70 weight-% Ni, 30 to 50 weight-% Co, 15 to 25 weight-% Cr, 5 to 15 weight-% Al and up to 1 weight-% Y.
     
    73. A method according to any of the claims 70 to 72,
    wherein the third coating is applied by thermal spray techniques such as VPS, LPPS, HVOF, CGS or by electroplating.
     
    74. A method according to any of the claims 58 to 73,
    wherein the part of the platform (4) is the top surface and/or the side face of the platform (4).
     
    75. A method according to any of the claims 53 to 74,
    wherein none of the coatings comprises Pt.
     
    76. A method according to any of the claims 53 to 75,
    wherein the component (1) consists of a super alloy, e.g. MarM247, IN6203 or CMSX4.
     
    77. A method according to any of the claims 53 to 76,
    wherein the turbine component (1) is a turbine blade.
     


    Ansprüche

    1. Turbinenkomponente (1) mit
    einem Fuß (2),
    einem Hals (3),
    einer Plattform (4) und
    einem Schaufelblatt (5)
    mit einer Außenfläche (6) und einer Innenfläche (7), welche Kühlkanäle (8) durch dieses definieren,
    wobei mindestens eine erste Beschichtung auf dem Fuß (2) vorgesehen ist und wobei eine zweite Beschichtung auf dem Hals (3) vorgesehen ist,
    wobei sich die Zusammensetzung der ersten Beschichtung von derjenigen der zweiten Beschichtung unterscheidet.
     
    2. Turbinenkomponente (1) nach Anspruch 1,
    wobei eine dritte Beschichtung auf der Innenfläche (7) des Schaufelblattes (5) vorgesehen ist,
    wobei sich die erste, die zweite und die dritte Beschichtung in ihrer Zusammensetzung unterscheiden.
     
    3. Turbinenkomponente (1) nach Anspruch 1 oder 2,
    wobei die zweite Beschichtung auch auf der Außenfläche (6) des Schaufelblattes (5) und auf wenigstens einem Teil der Plattform (4) vorgesehen ist.
     
    4. Turbinenkomponente (1) nach einem der Ansprüche 1 bis 2,
    wobei die erste Beschichtung Cr umfasst.
     
    5. Turbinenkomponente (1) nach Anspruch 4,
    wobei das Cr der ersten Beschichtung in die Komponente (1) diffundiert wird,
    wobei insbesondere nur Cr diffundiert wird.
     
    6. Turbinenkomponente (1) nach Anspruch 5,
    wobei das Cr der ersten Beschichtung durch Pack-Beschichten oder durch chemische Gasphasenabscheidung (CVD) diffundiert wird.
     
    7. Turbinenkomponente (1) nach einem der Ansprüche 4 bis 6,
    wobei die erste Beschichtung eine Schicht ist, die 15 bis 30 Gew.-% Cr umfasst und/oder 5 bis 25 µm dick ist.
     
    8. Turbinenkomponente (1) nach einem der Ansprüche 1 bis 7, wobei die zweite Beschichtung MCrAlY umfasst,
    wobei M Co oder Ni oder beides ist,
    wobei insbesondere die zweite Beschichtung aus MCrAlY besteht.
     
    9. Turbinenkomponente (1) nach Anspruch 8,
    wobei die zweite Beschichtung ferner Re, Si, Hf und/oder Y umfasst,
    insbesondere Y.
     
    10. Turbinenkomponente (1) nach einem der Ansprüche 8 oder 9, wobei die zweite Beschichtung folgende Zusammensetzung aufweist:

    30 bis 70 Gew.-% Ni,

    30 bis 50 Gew.-% Co,

    15 bis 25 Gew.-% Cr,

    5 bis 15 Gew.-% Al und

    bis 1 Gew.-% Y.


     
    11. Turbinenkomponente (1) nach einem der Ansprüche 1, 2, 3, 8 bis 10,
    wobei die zweite Beschichtung durch thermische Spritzverfahren, wie etwa Vakuum-Plasmaspritzen (VPS), Niederdruck-Plasmaspritzen (LPPS), Hochgeschwindigkeits-Flammspritzen (HVOF), Kaltgasspritzen (CGS), oder durch Galvanisieren aufgebracht wird.
     
    12. Turbinenkomponente (1) nach einem der Ansprüche 2 bis 11,
    wobei die dritte Beschichtung Cr und Al umfasst.
     
    13. Turbinenkomponente (1) nach Anspruch 12,
    wobei die dritte Beschichtung eine Al-modifizierte Cr-Beschichtung ist, wobei insbesondere nur Al und Cr zum Diffundieren verwendet werden.
     
    14. Turbinenkomponente (1) nach Anspruch 13,
    wobei die dritte Beschichtung hergestellt wird, indem Al in eine verchromte Oberfläche diffundiert wird.
     
    15. Turbinenkomponente (1) nach Anspruch 14,
    wobei das Al in die verchromte Oberfläche durch CVD oder andere Verfahren, wie etwa Above-the-Pack (ATP), diffundiert wird.
     
    16. Turbinenkomponente (1) nach einem der Ansprüche 12 bis 15,
    wobei die dritte Beschichtung eine Zusammensetzung in einer äußeren Beta-Schicht von 15 bis 30 Gew.-% Al und 5 bis 15 Gew.-% Cr aufweist.
     
    17. Turbinenkomponente (1) nach Anspruch 1,
    wobei die zweite Beschichtung auf der Innenfläche (7) und auf der Außenfläche (6) des Schaufelblattes (5) und auf wenigstens einem Teil der Plattform (4) vorgesehen ist.
     
    18. Turbinenkomponente (1) nach Anspruch 17,
    wobei eine dritte Beschichtung auf dem Hals (3) vorgesehen ist,
    wobei sich die erste, die zweite und die dritte Beschichtung in ihrer Zusammensetzung unterscheiden.
     
    19. Turbinenkomponente (1) nach Anspruch 17 oder Anspruch 18,
    wobei die erste Beschichtung Cr umfasst.
     
    20. Turbinenkomponente (1) nach Anspruch 19,
    wobei das Cr der ersten Beschichtung in die Komponente (1) diffundiert wird,
    wobei insbesondere nur Cr diffundiert wird.
     
    21. Turbinenkomponente (1) nach Anspruch 20,
    wobei das Cr der ersten Beschichtung durch Pack-Beschichten oder CVD diffundiert wird.
     
    22. Turbinenkomponente (1) nach einem der Ansprüche 17 bis 21,
    wobei die erste Beschichtung eine Schicht ist, die 15 bis 30 Gew.-% Cr umfasst und/oder 5 bis 25 µm dick ist.
     
    23. Turbinenkomponente (1) nach einem der Ansprüche 17 bis 22,
    wobei die zweite Beschichtung Cr und Al umfasst.
     
    24. Turbinenkomponente (1) nach Anspruch 23,
    wobei die zweite Beschichtung eine Al-modifizierte Cr-Beschichtung ist.
     
    25. Turbinenkomponente (1) nach Anspruch 24,
    wobei die zweite Beschichtung hergestellt wird, indem Al in eine verchromte Oberfläche diffundiert wird,
    wobei insbesondere nur Al und Cr zum Diffundieren verwendet werden.
     
    26. Turbinenkomponente (1) nach Anspruch 25,
    wobei das Al in die verchromte Oberfläche durch CVD oder andere Verfahren, wie etwa ATP, diffundiert wird.
     
    27. Turbinenkomponente (1) nach einem der Ansprüche 23 bis 26,
    wobei die zweite Beschichtung eine Zusammensetzung in einer äußeren Beta-Schicht von 15 bis 30 Gew.-% Al und 5 bis 15 Gew.-% Cr aufweist.
     
    28. Turbinenkomponente (1) nach einem der Ansprüche 18 bis 27,
    wobei die dritte Beschichtung MCrAlY umfasst, wobei M Co oder Ni oder beides ist,
    wobei insbesondere die dritte Beschichtung aus MCrAlY besteht.
     
    29. Turbinenkomponente (1) nach Anspruch 28,
    wobei die dritte Beschichtung ferner Re, Si, Hf und/oder Y umfasst,
    insbesondere Y.
     
    30. Turbinenkomponente (1) nach Anspruch 18 oder 29,
    wobei die dritte Beschichtung folgende Zusammensetzung aufweist:

    30 bis 70 Gew.-% Ni,

    30 bis 50 Gew.-% Co,

    15 bis 25 Gew.-% Cr,

    5 bis 15 Gew.-% Al und

    bis 1 Gew.-% Y.


     
    31. Turbinenkomponente (1) nach einem der Ansprüche 18, 28 bis 30,
    wobei die dritte Beschichtung durch thermische Spritzverfahren, wie etwa VPS, LPPS, HVOF, CGS, oder durch Galvanisieren aufgebracht wird.
     
    32. Turbinenkomponente (1) nach einem der Ansprüche 3 bis 31,
    wobei der zu beschichtende Teil der Plattform (4) die Oberseite und/oder die Seitenfläche der Plattform (4) ist.
     
    33. Turbinenkomponente (1) nach Anspruch 1,
    wobei die erste Beschichtung auch auf der Innenfläche (7) des Schaufelblattes (5) vorgesehen ist.
     
    34. Turbinenkomponente (1) nach Anspruch 33,
    wobei eine zweite Beschichtung auf der Außenfläche (6) des Schaufelblattes (5) und
    auf der Oberseite und/oder
    auf der Seitenfläche der Plattform (4) vorgesehen ist,
    wobei sich die erste und die zweite Beschichtung in ihrer Zusammensetzung unterscheiden.
     
    35. Turbinenkomponente (1) nach Anspruch 33,
    wobei eine dritte Beschichtung über der zweiten Beschichtung auf der Außenfläche (6) des Schaufelblattes (5) und
    auf der Oberseite und/oder
    auf der Seitenfläche der Plattform (4) vorgesehen ist,
    wobei sich die erste, die zweite und die dritte Beschichtung in ihrer Zusammensetzung unterscheiden.
     
    36. Turbinenkomponente (1) nach einem der Ansprüche 33 bis 35,
    wobei die erste Beschichtung Cr umfasst.
     
    37. Turbinenkomponente (1) nach Anspruch 36,
    wobei das Cr der ersten Beschichtung in die Komponente (1) diffundiert wird,
    wobei insbesondere nur Cr diffundiert wird.
     
    38. Turbinenkomponente (1) nach Anspruch 37,
    wobei das Cr der ersten Beschichtung durch Pack-Beschichten oder durch chemische Gasphasenabscheidung (CVD) diffundiert wird.
     
    39. Turbinenkomponente (1) nach einem der Ansprüche 36 bis 38,
    wobei die erste Beschichtung eine Schicht ist, die 15 bis 30 Gew.-% Cr umfasst und/oder 5 bis 25 µm dick ist.
     
    40. Turbinenkomponente (1) nach einem der Ansprüche 33 bis 39,
    wobei die zweite Beschichtung MCrAlY umfasst,
    wobei M Co oder Ni oder beides ist,
    wobei insbesondere die zweite Beschichtung aus MCrAlY besteht.
     
    41. Turbinenkomponente (1) nach Anspruch 40,
    wobei die dritte Beschichtung ferner Re, Si, Hf und/oder Y umfasst,
    insbesondere Y.
     
    42. Turbinenkomponente (1) nach einem der Ansprüche 34 oder 41,
    wobei die zweite Beschichtung folgende Zusammensetzung aufweist:

    30 bis 70 Gew.-% Ni,

    30 bis 50 Gew.-% Co,

    15 bis 25 Gew.-% Cr,

    5 bis 15 Gew.-% Al und

    bis 1 Gew.-% Y.


     
    43. Turbinenkomponente (1) nach einem der Ansprüche 35, 40 bis 42,
    wobei die dritte Beschichtung durch thermische Spritzverfahren, wie etwa VPS, LPPS, HVOF, CGS, oder durch Galvanisieren aufgebracht wird.
     
    44. Turbinenkomponente (1) nach einem der Ansprüche 35 bis 43,
    wobei die dritte Beschichtung Al umfasst.
     
    45. Turbinenkomponente (1) nach Anspruch 44,
    wobei die dritte Beschichtung überaluminisiert wird.
     
    46. Turbinenkomponente (1) nach Anspruch 45,
    wobei das Al der dritten Beschichtung durch Pack-Beschichten oder durch chemische Gasphasenabscheidung (CVD) überaluminisiert wird.
     
    47. Turbinenkomponente (1) nach Anspruch 46,
    wobei die Außenfläche der zweiten Beschichtung einen Al-Gehalt zwischen 15 und 30 Gew.-% aufweist.
     
    48. Turbinenkomponente (1) nach einem der Ansprüche 1 bis 47,
    wobei keine der Beschichtungen Pt umfasst.
     
    49. Turbinenkomponente (1) nach einem der Ansprüche 1 bis 48,
    wobei die Turbinenkomponente (1) aus einer Superlegierung besteht, z B. MarM247, IN6203 oder CMSX4.
     
    50. Turbinenkomponente (1) nach Anspruch 49,
    wobei die Turbinenkomponente (1) durch herkömmliche Gießverfahren oder Gießverfahren mit direktionaler Verfestigung hergestellt wird.
     
    51. Turbinenkomponente (1) nach einem der Ansprüche 1 bis 50,
    wobei die Turbinenkomponente (1) eine Turbinenlaufschaufel ist.
     
    52. Turbine, welche eine erste Stufe von Laufschaufeln und Leitschaufeln und eine zweite Stufe von Laufschaufeln und Leitschaufeln umfasst,
    wobei die Laufschaufeln der ersten Stufe Turbinenkomponenten (1) nach einem der Ansprüche 1 bis 16 oder 32 sind und
    die Laufschaufeln der zweiten Stufe Turbinenschaufelkomponenten (1) nach einem der Ansprüche 17 bis 32 sind.
     
    53. Verfahren zum Beschichten einer Turbinenkomponente (1), welche einen Fuß (2),
    einen Hals (3),
    ein Schaufelblatt (5) mit einer Außenfläche (6) und einer Innenfläche (7), welche Kühlkanäle (8) durch dieses definieren, aufweist,
    welches die folgenden Schritte umfasst:

    - Aufbringen einer ersten Beschichtung auf alle Außen- und Innenflächen der Komponente (1);

    - Aufbringen einer zweiten Beschichtung auf einen ersten Abschnitt der beschichteten Komponente (1), wobei der erste Abschnitt den Hals (3) umfasst;

    - Aufbringen einer dritten Beschichtung auf einen zweiten Abschnitt der beschichteten Komponente (1),

    wobei die erste, die zweite und die dritte Beschichtung unterschiedliche Zusammensetzungen aufweisen.
     
    54. Verfahren nach Anspruch 53,
    wobei die erste Beschichtung in die Komponente (1) diffundiert wird.
     
    55. Verfahren nach Anspruch 54,
    wobei die erste Beschichtung durch Pack-Beschichten oder durch chemische Gasphasenabscheidung (CVD) diffundiert wird.
     
    56. Verfahren nach Anspruch 55,
    wobei die erste Beschichtung Cr umfasst.
     
    57. Verfahren nach einem der Ansprüche 53 bis 56,
    wobei die erste Beschichtung eine Schicht ist, die 15 bis 30 Gew.-% Cr umfasst und/oder 5 bis 25 µm dick ist.
     
    58. Verfahren nach einem der Ansprüche 53 bis 57,
    wobei der erste Abschnitt ferner die Außenfläche (6) des Schaufelblattes (5) und wenigstens einen Teil der Plattform (4) umfasst, und wobei der zweite Abschnitt die Innenfläche (7) des Schaufelblattes (5) umfasst.
     
    59. Verfahren nach Anspruch 58,
    wobei die zweite Beschichtung MCrAlY umfasst, wobei M Co oder Ni oder beides ist.
     
    60. Verfahren nach Anspruch 59,
    wobei die zweite Beschichtung ferner Re, Si, Hf und/oder Y umfasst.
     
    61. Verfahren nach Anspruch 60,
    wobei die zweite Beschichtung eine Zusammensetzung aus 30 bis 70 Gew.-% Ni, 30 bis 50 Gew.-% Co, 15 bis 25 Gew.-% Cr, 5 bis 15 Gew.-% Al und bis 1 Gew.-% Y aufweist.
     
    62. Verfahren nach einem der Ansprüche 59 bis 61,
    wobei die zweite Beschichtung durch thermische Spritzverfahren, wie etwa Vakuum-Plasmaspritzen (VPS), Niederdruck-Plasmaspritzen (LPPS), Hochgeschwindigkeits-Flammspritzen (HVOF), Kaltgasspritzen (CGS), oder durch Galvanisieren aufgebracht wird.
     
    63. Verfahren nach einem der Ansprüche 53 bis 62,
    wobei die dritte Beschichtung durch Diffusion aufgebracht wird.
     
    64. Verfahren nach Anspruch 63,
    wobei die dritte Beschichtung Al umfasst.
     
    65. Verfahren nach Anspruch 64,
    wobei das Al durch CVD oder andere Verfahren, wie etwa Above-the-Pack (ATP), diffundiert wird.
     
    66. Verfahren nach einem der Ansprüche 53 bis 57,
    wobei der erste Abschnitt ferner die Innenfläche (7) und die Außenfläche (6) des Schaufelblattes (5) und wenigstens einen Teil der Plattform (4) umfasst und wobei der zweite Abschnitt den Hals (3) umfasst.
     
    67. Verfahren nach Anspruch 66,
    wobei die zweite Beschichtung durch Diffusion aufgebracht wird.
     
    68. Verfahren nach Anspruch 67,
    wobei die zweite Beschichtung Al umfasst.
     
    69. Verfahren nach Anspruch 68,
    wobei die zweite Beschichtung durch CVD oder andere Verfahren, wie etwa ATP, diffundiert wird.
     
    70. Verfahren nach einem der Ansprüche 66 bis 69,
    wobei die dritte Beschichtung MCrAlY umfasst, wobei M Co oder Ni oder beides ist.
     
    71. Verfahren nach Anspruch 70,
    wobei die dritte Beschichtung ferner Re, Si, Hf und/oder Y umfasst.
     
    72. Verfahren nach Anspruch 71,
    wobei die dritte Beschichtung eine Zusammensetzung aus 30 bis 70 Gew.-% Ni, 30 bis 50 Gew.-% Co, 15 bis 25 Gew.-% Cr, 5 bis 15 Gew.-% Al und bis 1 Gew.-% Y aufweist.
     
    73. Verfahren nach einem der Ansprüche 70 bis 72,
    wobei die dritte Beschichtung durch thermische Spritzverfahren, wie etwa VPS, LPPS, HVOF, CGS, oder durch Galvanisieren aufgebracht wird.
     
    74. Verfahren nach einem der Ansprüche 58 bis 73,
    wobei der Teil der Plattform (4) die Oberseite und/oder die Seitenfläche der Plattform (4) ist.
     
    75. Verfahren nach einem der Ansprüche 53 bis 74,
    wobei keine der Beschichtungen Pt umfasst.
     
    76. Verfahren nach einem der Ansprüche 53 bis 75,
    wobei die Komponente (1) aus einer Superlegierung besteht, z B. MarM247, IN6203 oder CMSX4.
     
    77. Verfahren nach einem der Ansprüche 53 bis 76,
    wobei die Turbinenkomponente (1) eine Turbinenlaufschaufel ist.
     


    Revendications

    1. Composant (1) de turbine comprenant
    un talon (2) ;
    un col (3) ;
    une plate-forme (4), et
    une pale profilée (5)
    présentant une surface externe (6) et une surface interne (7) définissant des passages de refroidissement (8) à travers elle,
    étant entendu qu'au moins un premier revêtement est prévu sur le talon (2) et qu'un deuxième revêtement est prévu sur le col (3),
    la composition du premier revêtement différant de celle du deuxième revêtement.
     
    2. Composant (1) de turbine selon la revendication 1,
    dans lequel un troisième revêtement est réalisé sur la surface interne (7) de la pale profilée (5),
    le premier revêtement, le deuxième et le troisième différant par leur composition.
     
    3. Composant (1) de turbine selon la revendication 1 ou 2,
    dans lequel le deuxième revêtement est aussi réalisé sur la surface externe (6) de la pale profilée (5) et sur au moins une partie de la plate-forme (4).
     
    4. Composant (1) de turbine selon l'une quelconque des revendications 1 ou 2,
    dans lequel le premier revêtement comprend du Cr.
     
    5. Composant (1) de turbine selon la revendication 4,
    dans lequel le Cr du premier revêtement est diffusé dans le composant (1),
    en particulier seul du Cr est diffusé.
     
    6. Composant (1) de turbine selon la revendication 5,
    dans lequel le Cr du premier revêtement est diffusé par cémentation solide ou par dépôt chimique en phase vapeur (CVD).
     
    7. Composant (1) de turbine selon l'une quelconque des revendications 4 à 6,
    dans lequel le premier revêtement est une couche comprenant 15 à 30 % en poids de Cr et/ou
    faisant 5 à 25 µm d'épaisseur.
     
    8. Composant (1) de turbine selon l'une quelconque des revendications 1 à 7,
    dans lequel le deuxième revêtement comprend du MCrAlY,
    M étant du Co ou du Ni ou les deux,
    en particulier le deuxième revêtement consiste en MCrAlY.
     
    9. Composant (1) de turbine selon la revendication 8,
    dans lequel le deuxième revêtement comprend par ailleurs du Re, du Si, du Hf et/ou de l'Y,
    en particulier de l'Y.
     
    10. Composant (1) de turbine selon la revendication 8 ou 9,
    dans lequel le deuxième revêtement a une composition comprenant
    30 à 70 % en poids de Ni ;
    30 à 50 % en poids de Co ;
    15 à 25 % en poids de Cr ;
    5 à 15 % en poids d'Al, et
    jusqu'à 1 % en poids d'Y.
     
    11. Composant (1) de turbine selon l'une quelconque des revendications 1, 2, 3, 8 à 10,
    dans lequel le deuxième revêtement est appliqué au moyen de procédés de projection thermique tel que la projection par plasma sous vide (VPS), la projection par plasma sous basse pression (LPPS), la projection par flamme supersonique (HVOF), la projection par gaz froid (CGS) ou l'électroplastie.
     
    12. Composant (1) de turbine selon l'une quelconque des revendications 2 à 11,
    dans lequel le troisième revêtement comprend du Cr et de l'Al.
     
    13. Composant (1) de turbine selon la revendication 12,
    dans lequel le troisième revêtement est un revêtement de Cr modifié par de l'Al,
    en particulier seuls l'Al et le Cr sont utilisés pour la diffusion.
     
    14. Composant (1) de turbine selon la revendication 13,
    dans lequel le troisième revêtement est réalisé par diffusion d'Al dans une surface chromisée.
     
    15. Composant (1) de turbine selon la revendication 14,
    dans lequel l'Al est diffusé dans la surface chromisée par CVD ou au moyen d'autres procédés tels que celui dit above the pack (ATP).
     
    16. Composant (1) de turbine selon l'une quelconque des revendications 12 à 15,
    dans lequel le troisième revêtement a une composition dans une couche bêta externe de 15 à 30 % en poids d'Al et de 5 à 15 % en poids de Cr.
     
    17. Composant (1) de turbine selon la revendication 1,
    dans lequel le deuxième revêtement est réalisé sur la surface interne (7) et sur la surface externe (6) de la pale profilée (5) et sur au moins une partie de la plate-forme (4).
     
    18. Composant (1) de turbine selon la revendication 17,
    dans lequel un troisième revêtement est réalisé sur le col (3), le premier revêtement, le deuxième et le troisième différant par leur composition.
     
    19. Composant (1) de turbine selon la revendication 17 ou la revendication 18,
    dans lequel le premier revêtement comprend du Cr.
     
    20. Composant (1) de turbine selon la revendication 19,
    dans lequel le Cr du premier revêtement est diffusé dans le composant (1),
    en particulier seul du Cr est diffusé.
     
    21. Composant (1) de turbine selon la revendication 20,
    dans lequel le Cr du premier revêtement est diffusé par cémentation solide ou CVD.
     
    22. Composant (1) de turbine selon l'une quelconque des revendications 17 à 21,
    dans lequel le premier revêtement est une couche comprenant 15 à 30 % en poids de Cr et/ou
    faisant 5 à 25 µm d'épaisseur.
     
    23. Composant (1) de turbine selon l'une quelconque des revendications 17 à 22,
    dans lequel le deuxième revêtement comprend du Cr et de l'Al.
     
    24. Composant (1) de turbine selon la revendication 23,
    dans lequel le deuxième revêtement est un revêtement de Cr modifié par de l'Al.
     
    25. Composant (1) de turbine selon la revendication 24,
    dans lequel le deuxième revêtement est réalisé par diffusion d'Al dans une surface chromisée,
    en particulier seuls l'Al et le Cr sont utilisés pour la diffusion.
     
    26. Composant (1) de turbine selon la revendication 25,
    dans lequel l'Al est diffusé dans la surface chromisée par CVD ou au moyen d'autres procédés tels que l'ATP.
     
    27. Composant (1) de turbine selon l'une quelconque des revendications 23 à 26,
    dans lequel le deuxième revêtement a une composition dans une couche bêta externe comprenant de 15 à 30 % en poids d'Al et 5 à 15 % en poids de Cr.
     
    28. Composant (1) de turbine selon l'une quelconque des revendications 18 à 27,
    dans lequel le troisième revêtement comprend du MCrAlY, M étant du Co ou du Ni ou les deux,
    en particulier le troisième revêtement consiste en MCrAlY.
     
    29. Composant (1) de turbine selon la revendication 28,
    dans lequel le troisième revêtement comprend par ailleurs du Re, du Si, du Hf et/ou de l'Y,
    en particulier de l'Y.
     
    30. Composant (1) de turbine selon la revendication 18 ou 29, dans lequel le troisième revêtement a une composition comprenant
    30 à 70 % en poids de Ni ;
    30 à 50 % en poids de Co ;
    15 à 25 % en poids de Cr ;
    5 à 15 % en poids d'Al, et
    jusqu'à 1 % en poids d'Y.
     
    31. Composant (1) de turbine selon l'une quelconque des revendications 18, 28 à 30,
    dans lequel le troisième revêtement est appliqué au moyen de procédés de projection thermique tel que la VPS, la LPPS, la HVOF, la CGS ou l'électroplastie.
     
    32. Composant (1) de turbine selon l'une quelconque des revendications 3 à 31,
    dans lequel la partie de la plate-forme (4) à revêtir est la surface supérieure et/ou la face latérale de la plate-forme (4).
     
    33. Composant (1) de turbine selon la revendication 1,
    dans lequel le premier revêtement est aussi réalisé sur la surface interne (7) de la pale profilée (5).
     
    34. Composant (1) de turbine selon la revendication 33, dans lequel
    un deuxième revêtement est réalisé sur la surface externe (6) de la pale profilée (5) et
    sur la face supérieure et/ou
    sur la face latérale de la plate-forme (4),
    le premier revêtement et le deuxième différant par leur composition.
     
    35. Composant (1) de turbine selon la revendication 33,
    dans lequel un troisième revêtement est prévu au-dessus du deuxième revêtement sur la surface externe (6) de la pale profilée (5) et
    sur la face supérieure et/ou
    la face latérale de la plate-forme (4),
    le premier revêtement, le deuxième et le troisième différant par leur composition.
     
    36. Composant (1) de turbine selon l'une quelconque des revendications 33 à 35,
    dans lequel le premier revêtement comprend du Cr.
     
    37. Composant (1) de turbine selon la revendication 36,
    dans lequel le Cr du premier revêtement est diffusé dans le composant (1),
    en particulier seul du Cr est diffusé.
     
    38. Composant (1) de turbine selon la revendication 37,
    dans lequel le Cr du premier revêtement est diffusé par cémentation solide ou par dépôt chimique en phase vapeur (CVD).
     
    39. Composant (1) de turbine selon l'une quelconque des revendications 36 à 38,
    dans lequel le premier revêtement est une couche comprenant 15 à 30 % en poids de Cr et/ou
    faisant 5 à 25 µm d'épaisseur.
     
    40. Composant (1) de turbine selon l'une quelconque des revendications 33 à 39,
    dans lequel le deuxième revêtement comprend du MCrAlY,
    M étant du Co ou du Ni ou les deux,
    en particulier le deuxième revêtement consiste en MCrAlY.
     
    41. Composant (1) de turbine selon la revendication 40,
    dans lequel le troisième revêtement comprend par ailleurs du Re, du Si, du Hf et/ou de l'Y,
    en particulier de l'Y.
     
    42. Composant (1) de turbine selon la revendication 34 ou 41,
    dans lequel le deuxième revêtement a une composition comprenant
    30 à 70 % en poids de Ni ;
    30 à 50 % en poids de Co ;
    15 à 25 % en poids de Cr ;
    5 à 15 % en poids d'Al, et
    jusqu'à 1 % en poids d'Y.
     
    43. Composant (1) de turbine selon l'une quelconque des revendications 35, 40 à 42,
    dans lequel le troisième revêtement est appliqué au moyen de procédés de projection thermique tels que la VPS, la LPPS, la HVOF, la CGS ou l'électroplastie.
     
    44. Composant (1) de turbine selon l'une quelconque des revendications 35 à 43,
    dans lequel le troisième revêtement comprend de l'Al.
     
    45. Composant (1) de turbine selon la revendication 44,
    dans lequel le troisième revêtement est aluminisé.
     
    46. Composant (1) de turbine selon la revendication 45,
    dans lequel l'Al du troisième revêtement est aluminisé par cémentation solide ou par dépôt chimique en phase vapeur (CVD).
     
    47. Composant (1) de turbine selon la revendication 46,
    dans lequel la surface externe du deuxième revêtement a une teneur en Al allant de 15 à 30 % en poids.
     
    48. Composant (1) de turbine selon l'une quelconque des revendications 1 à 47,
    dans lequel aucun des revêtements ne comprend de Pt.
     
    49. Composant (1) de turbine selon l'une quelconque des revendications 1 à 48,
    dans lequel le composant (1) de turbine consiste en un superalliage, par exemple le MarM247, l'IN6203 ou le CMSX4.
     
    50. Composant (1) de turbine selon la revendication 49,
    dans lequel le composant (1) de turbine est réalisé au moyen de procédés de moulage classiques ou à solidification dirigée.
     
    51. Composant (1) de turbine selon l'une quelconque des revendications 1 à 50,
    dans lequel le composant (1) de turbine est une aube mobile de turbine.
     
    52. Turbine comprenant un premier étage d'aubes mobiles et fixes et un second étage d'aubes mobiles et fixes,
    dans laquelle les aubes mobiles du premier étage sont des composants (1) de turbine selon l'une quelconque des revendications 1 à 16 ou 32 et
    les aubes mobiles du second étage sont des composants (1) de turbine selon l'une quelconque des revendications 17 à 32.
     
    53. Procédé de revêtement d'un composant (1) de turbine, comprenant un talon (2),
    un col (3) ;
    une plate-forme (4), et
    une pale profilée (5) présentant une surface externe (6) et une surface interne (7) définissant des passages de refroidissement (8) à travers elle,
    comprenant les étapes consistant :

    - à appliquer un premier revêtement sur toutes les surfaces externes et internes du composant (1) ;

    - à appliquer un deuxième revêtement sur une première partie du composant (1) revêtu, la première partie comprenant le col (3) ;

    - à appliquer un troisième revêtement sur une seconde partie du composant (1) revêtu,

    étant entendu que le premier revêtement, le deuxième et le troisième ont des compositions différentes.
     
    54. Procédé selon la revendication 53,
    dans lequel le premier revêtement est diffusé dans le composant (1).
     
    55. Procédé selon la revendication 54,
    dans lequel le premier revêtement est diffusé par cémentation solide ou par dépôt chimique en phase vapeur (CVD).
     
    56. Procédé selon la revendication 55,
    dans lequel le premier revêtement comprend du Cr.
     
    57. Procédé selon l'une quelconque des revendications 53 à 56,
    dans lequel le premier revêtement est une couche comprenant 15 à 30 % en poids de Cr et/ou faisant 5 à 25 µm d'épaisseur.
     
    58. Procédé selon l'une quelconque des revendications 53 à 57,
    dans lequel la première partie comprend par ailleurs la surface externe (6) de la pale profilée (5) et au moins une partie de la plate-forme (4) et dans lequel la seconde partie comprend la surface interne (7) de la pale profilée (5).
     
    59. Procédé selon la revendication 58,
    dans lequel le deuxième revêtement comprend du MCrAlY, M étant du Co ou du Ni ou les deux.
     
    60. Procédé selon la revendication 59,
    dans lequel le deuxième revêtement comprend par ailleurs du Re, du Si, du Hf et/ou de l'Y.
     
    61. Procédé selon la revendication 60,
    dans lequel le deuxième revêtement a une composition comprenant 30 à 70 % en poids de Ni, 30 à 50 % en poids de Co, 15 à 25 % en poids de Cr, 5 à 15 % en poids d'Al et jusqu'à 1 % en poids d'Y.
     
    62. Procédé selon l'une quelconque des revendications 59 à 61,
    dans lequel le deuxième revêtement est appliqué au moyen de procédés de projection thermique tels que la projection par plasma sous vide (VPS), la projection par plasma sous basse pression (LPPS), la projection par flamme supersonique (HVOF), la projection par gaz froid (CGS) ou l'électroplastie.
     
    63. Procédé selon l'une quelconque des revendications 53 à 62,
    dans lequel le troisième revêtement est appliqué par diffusion.
     
    64. Procédé selon la revendication 63,
    dans lequel le troisième revêtement comprend de l'Al.
     
    65. Procédé selon la revendication 64,
    dans lequel l'Al est diffusé par CVD ou au moyen d'autres procédés tels que celui dit above the pack (ATP).
     
    66. Procédé selon l'une quelconque des revendications 53 à 57,
    dans lequel la première partie comprend par ailleurs la surface interne (7) et la surface externe (6) de la pale profilée et au moins une partie de la plate-forme (4) et dans lequel la seconde partie comprend le col (3).
     
    67. Procédé selon la revendication 66,
    dans lequel le deuxième revêtement est appliqué par diffusion.
     
    68. Procédé selon la revendication 67,
    dans lequel le deuxième revêtement comprend de l'Al.
     
    69. Procédé selon la revendication 68,
    dans lequel le deuxième revêtement est diffusé par CVD ou au moyen d'autres procédés tels que l'ATP.
     
    70. Procédé selon l'une quelconque des revendications 66 à 69,
    dans lequel le troisième revêtement comprend du MCrAlY, M étant du Co ou du Ni ou les deux.
     
    71. Procédé selon la revendication 70,
    dans lequel le troisième revêtement comprend par ailleurs du Re, du Si, du Hf et/ou de l'Y.
     
    72. Procédé selon la revendication 71,
    dans lequel le troisième revêtement a une composition comprenant 30 à 70 % en poids de Ni, 30 à 50 % en poids de Co, 15 à 25 % en poids de Cr, 5 à 15 % en poids d'Al et jusqu'à 1 % en poids d'Y.
     
    73. Procédé selon l'une quelconque des revendications 70 à 72,
    dans lequel le troisième revêtement est appliqué au moyen de procédés de projection thermique tels que la VPS, la LPPS, la HVOF, la CGS ou par électroplastie.
     
    74. Procédé selon l'une quelconque des revendications 58 à 73,
    dans lequel la partie de la plate-forme (4) est la surface supérieure et/ou la face latérale de la plate-forme (4).
     
    75. Procédé selon l'une quelconque des revendications 53 à 74,
    dans lequel aucun des revêtements ne comprend du Pt.
     
    76. Procédé selon l'une quelconque des revendications 53 à 75,
    dans lequel le composant (1) consiste en un superalliage, par exemple le MarM247, l'IN6203 ou le CMSX4.
     
    77. Procédé selon l'une quelconque des revendications 53 à 76,
    dans lequel le composant (1) de turbine est une aube mobile de turbine.
     




    Drawing
































    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description