EP2584067A1 - Component with graphene and method for producing components with graphene - Google Patents

Abstract

The component (1) has a substrate (4) and graphene layer (7'). The substrate is made of metallic material such as nickel-or cobalt-based superalloy. The graphene layer is directly arranged on the substrate. A metallic protective layer such as metal-chromium-aluminum layer (10) is formed on the substrate. A ceramic layer is directly arranged on the graphene layer. An independent claim is included for method for producing component.

Description

The invention relates to components with graphene, which serve for the oxidation and / or corrosion protection and mechanical stability of components which are used in particular at high temperatures, as well as a method for the production of components with graphene.

Materials for high-temperature applications must have good mechanical strength at high temperatures and generally also good oxidation properties.

This combination is rare for a material alone, so that protective layers are applied to substrates that serve to protect against oxidation. These are e.g. Aluminide, platinum aluminide or MCrAl layers on nickel- or cobalt-based substrates.

However, these protective layers consume and do not have the same mechanical properties as the substrate.

It is therefore an object of the invention to solve this problem.

The object is achieved by a layer system with graphene according to claim 1 and a method according to claim 9.

In the dependent claims further advantageous measures are listed, which can be combined with each other in order to achieve further advantages.

Figuren 1 - 10

verschiedene Ausführungsbeispiele der Erfindung,

Figur 11

Graphen,

Figur 12

eine Turbinenschaufel,

Figur 13

eine Brennkammer,

Figur 14

eine Gasturbine,

Figur 15

eine Liste von Superlegierungen.

Show it:

Figures 1-10

different embodiments of the invention,

FIG. 11

graphs

FIG. 12

a turbine blade,

FIG. 13

a combustion chamber,

FIG. 14

a gas turbine,

FIG. 15

a list of superalloys.

The description and the figures represent only embodiments of the invention.

Graphene 7 ', 7 ", 7"', 7 ^IV , 7 ^V represents a two-dimensional honeycomb structure ( Fig. 11 ). Each node contains one carbon atom.

Graphene 7 'can preferably be applied directly to a substrate 4 according to FIG FIG. 1 be applied or be present. The substrate 4 may be metallic or ceramic. For high temperature components such as turbine blades 120, 130 or combustor elements 155, this is preferably a nickel-based or cobalt-based superalloy, especially a nickel-based superalloy, most preferably an alloy according to FIG FIG. 15 ,

The graph 7 'may already be cast in, i. it is already present in a casting during casting or is introduced into the melt there.

A protective layer 10, in particular a metallic protective layer 10, can preferably be applied over the graphene 7 'on the substrate 4 ( Fig. 3 ).

The graphene 7 'may be in direct contact with the protective layer 10 or may be disposed within the substrate 4.

Likewise, graphene 7 "may be applied to a protective layer 10, in particular to a metallic protective layer 10, which has already been applied on the substrate 4 in advance ( Fig. 2 ), with no further layer on the graph 7 ".

The metallic protective layer 10 is preferably an aluminide, platinum aluminide or MCrAl layer, the MCrAl layer 10 still further additives, in particular as yttrium (M = Ni, Co) (also preferably for Fig. 3, 4, 6 . 8, 9, 10 ).

FIG. 4 shows a further embodiment.

There is on the graph 7 "still applied an outer ceramic layer 13, ie corresponds to a component 1, 120, 130, 155 according to FIG. 2 with a ceramic layer 13, in particular an outermost ceramic layer 13.

FIG. 5 shows another embodiment in which graphene 7 '''represents the outermost layer on a ceramic layer 13.

Graphene 7 '''is applied to a ceramic layer 13. At least one metallic protective layer can be applied under this ceramic layer 13 (also in accordance with FIG Fig. 7 ; not shown in detail).

Likewise, the graphene 7 ', 7 ^IV , 7 ^{V can be arranged} within the metallic protective layer 10, and / or the ceramic layer 13 ( Fig. 6 . 7, 8, 9 ).

Likewise, graphene 7 '', 7 '''may be present on the metallic protective layer 10 and the outer ceramic layer 13 ( Fig. 10 ), wherein preferably the graphene also still within the layers (according to Fig. 6 . 8th ) may be arranged (not shown).

The thickness of the graph 7 ', 7 ",... Is shown only schematically in the figures.

Due to the high chemical resistance and the scarcely or not at all present tendency to oxidation and corrosion of graphene, graphs 7 ', 7 ",... Simply or multiply in a layer system 1, 120, 130, 155 on or in the metallic layer 10 or the ceramic layer 13 and / or on or in the ceramic layer 13, whereby the Exposure of oxidation and corrosion to the substrate 4, the metallic protective layer 10 is reduced, so that the oxidation and / or corrosion rates are significantly reduced (especially in the FIGS. 1, 2, 4, 5 . 7, 8, 9, 10 ) and the life of the layer 10, 13 is extended.

Likewise, the application or introduction of graphene 7 ', ... improves the mechanical strength of the protective layers 10, 13 and increases the lifetime of the layer system ( Figures 2 - 10 ).

Likewise applies to the embodiments of the FIGS. 1 to 10 in that an oxide, in particular aluminum oxide, can form or has formed on the substrate 4 or on the protective layer 10.

The graphene 7 ', 7'',7''', 7 ^IV , 7 ^V can be introduced into the warm and therefore soft layers 10 or is annealed or fixed by a laser treatment of the substrate 4 or the layer 10, 13.

It is also possible that graphene 7 ', 7'',7''', 7 ^IV , 7 ^{V is} grown directly on the substrate 4 or layers 10, 13.

It is likewise possible to apply graphene 7 ', 7 ",... To a substrate 4 or a metallic protective layer 10 or ceramic layer 13 and then to apply the material of the layer 10, 13 around the graph 7', 7",. .. or to over-spray the graph 7 ', 7 ", ... so that the graph 7', 7", ... is anchored.

The FIG. 12 shows a perspective view of a blade 120 or guide vane 130 of a turbomachine, which extends along a longitudinal axis 121.

The turbomachine may be a gas turbine of an aircraft or a power plant for power generation, a steam turbine or a compressor.

The blade 120, 130 has along the longitudinal axis 121 consecutively a fastening region 400, a blade platform 403 adjacent thereto and an airfoil 406 and a blade tip 415.

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

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

The blade root 183 is designed, for example, as a hammer head. Other designs as Christmas tree or Schwalbenschwanzfuß are possible.

The blade 120, 130 has a leading edge 409 and a trailing edge 412 for a medium flowing past the airfoil 406.

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

Such superalloys are for example from EP 1 204 776 B1 . EP 1 306 454 . EP 1 319 729 A1 . WO 99/67435 or WO 00/44949 known.

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

Workpieces with a single-crystal structure or structures are used as components for machines that are in operation high mechanical, thermal and / or chemical stresses are exposed.

The production of such monocrystalline workpieces takes place e.g. 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 that run the full length of the workpiece and here, in common usage, are referred to as directionally solidified) or a monocrystalline structure, i. the whole workpiece consists of a single crystal. In these processes, it is necessary to avoid the transition to globulitic (polycrystalline) solidification, since non-directional growth necessarily produces transverse and longitudinal grain boundaries which negate the good properties of the directionally solidified or monocrystalline component.

The term generally refers to directionally solidified microstructures, which means both single crystals that have no grain boundaries or at most small angle grain boundaries, and stem crystal structures that have probably longitudinal grain boundaries but no transverse grain boundaries. These second-mentioned crystalline structures are also known as directionally solidified structures. Such methods are known from U.S. Patent 6,024,792 and the EP 0 892 090 A1 known.

Likewise, the blades 120, 130 may have coatings against corrosion or oxidation, e.g. M is at least one element of the group iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and / or silicon and / or at least one element of the rare ones Earth, or hafnium (Hf)). Such alloys are known from the EP 0 486 489 B1 . EP 0 786 017 B1 . EP 0 412 397 B1 or EP 1 306 454 A1 ,

The density is preferably 95% of the theoretical density.

A protective aluminum oxide layer (TGO = thermal grown oxide layer) is formed on the MCrAlX layer (as an intermediate layer or as the outermost layer).

Preferably, the layer composition comprises Co-30Ni-28Cr-8A1-0.6Y-0.7Si or Co-28Ni-24Cr-10Al-0.6Y. In addition to these cobalt-based protective coatings, nickel-based protective layers such as Ni-10Cr-12Al-0.6Y-3Re or Ni-12Co-21Cr-11Al-0.4Y-2Re or Ni-25Co-17Cr-10Al-0.4Y-1 are also preferably used , 5RE.

On the MCrAlX may still be present a thermal barrier coating, which is preferably the outermost layer, and consists for example of ZrO ₂ , Y ₂ O ₃ -ZrO ₂ , ie it is not, partially or completely stabilized by yttria and / or calcium oxide and / or magnesium oxide.

The thermal barrier coating covers the entire MCrAlX layer. By suitable coating methods, e.g. Electron beam evaporation (EB-PVD) produces stalk-shaped grains in the thermal barrier coating.

Other coating methods are conceivable, e.g. atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may have porous, micro- or macro-cracked grains for better thermal shock resistance. The thermal barrier coating is therefore preferably more porous than the MCrAlX layer.

Refurbishment means that components 120, 130 may have to be freed of protective layers after use (eg 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 film cooling holes 418 (indicated by dashed lines) on.

The FIG. 13 shows a combustion chamber 110 of a gas turbine.

The combustion chamber 110 is configured, for example, as a so-called annular combustion chamber, in which a plurality of burners 107 arranged around a rotation axis 102 in the circumferential direction open into a common combustion chamber space 154, which generate flames. For this purpose, the combustion chamber 110 is configured in its entirety as an annular structure, which is positioned around the axis of rotation 102 around.

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 enable a comparatively long service life even with these, for the materials unfavorable operating parameters, the combustion chamber wall 153 is provided on its side facing the working medium M side with an inner lining formed from heat shield elements 155.

Each heat shield element 155 made of an alloy is equipped on the working medium side with a particularly heat-resistant protective layer (MCrAIX layer and / or ceramic coating) or is made of high-temperature-resistant material (solid ceramic stones).

These protective layers may be similar to the turbine blades, so for example MCrAlX means: M is at least one element of the group iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and / or silicon and / or at least one element of the rare earths, or hafnium (Hf). Such alloys are known from the EP 0 486 489 B1 . EP 0 786 017 B1 . EP 0 412 397 B1 or EP 1 306 454 A1 ,

On the MCrAlX, for example, a ceramic thermal barrier coating may be present and consists for example of ZrO ₂ , Y ₂ O ₃ -ZrO ₂ , ie it is not, partially or completely stabilized by yttria 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.

Other coating methods are conceivable, e.g. atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may have porous, micro- or macro-cracked grains for better thermal shock resistance.

Refurbishment means that heat shield elements 155 may need to be deprotected (e.g., by sandblasting) after use. This is followed by removal of the corrosion and / or oxidation layers or products. If necessary, cracks in the heat shield element 155 are also repaired. This is followed by a recoating of the heat shield elements 155 and a renewed use of the heat shield elements 155.

Due to the high temperatures inside the combustion chamber 110 may also be provided for the heat shield elements 155 and for their holding elements, a cooling system. The heat shield elements 155 are then, for example, hollow and possibly still have cooling holes (not shown) which open into the combustion chamber space 154.

The FIG. 14 shows by way of example a gas turbine 100 in a longitudinal partial section.

The gas turbine 100 has inside a rotatably mounted about a rotation axis 102 rotor 103 with a shaft 101, which is also referred to as a turbine runner.

Along the rotor 103 successively follow an intake housing 104, a compressor 105, for example, a torus-like

Combustion chamber 110, in particular annular combustion chamber, with a plurality of coaxially arranged burners 107, a turbine 108 and the exhaust housing 109th

The annular combustion chamber 110 communicates with an annular annular hot gas channel 111, for example. There, for example, four turbine stages 112 connected in series form the turbine 108.

Each turbine stage 112 is formed, for example, 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 an inner housing 138 of a stator 143, whereas the moving blades 120 of a row 125 are attached to the rotor 103 by means of a turbine disk 133, for example.

Coupled to the rotor 103 is a generator or work machine (not shown).

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

The components exposed to the hot working medium 113 are subject to thermal loads during operation of the gas turbine 100. The guide vanes 130 and rotor blades 120 of the first turbine stage 112 seen in the direction of flow of the working medium 113 become, in addition to the annular combustion chamber 110 lining heat shield elements most thermally stressed.

To withstand the prevailing temperatures, they can be cooled by means of a coolant.

Likewise, substrates of the components may have a directional structure, i. they are monocrystalline (SX structure) or have only longitudinal grains (DS structure).

As the material for the components, in particular for the turbine blade 120, 130 and components of the combustion chamber 110, for example, iron-, nickel- or cobalt-based superalloys are used.

Such superalloys are for example from EP 1 204 776 B1 . EP 1 306 454 . EP 1 319 729 A1 . WO 99/67435 or WO 00/44949 known.

Also, the blades 120, 130 may be anti-corrosion coatings (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 , Scandium (Sc) and / or at least one element of the rare earth or hafnium). Such alloys are known from the EP 0 486 489 B1 . EP 0 786 017 B1 . EP 0 412 397 B1 or EP 1 306 454 A1 ,

On the MCrAlX may still be present a thermal barrier coating, and consists for example of ZrO ₂ , Y ₂ O ₃ -ZrO ₂ , that is, it is not, partially or completely stabilized by yttria 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.

The vane 130 has a guide vane foot (not shown here) facing the inner housing 138 of the turbine 108 and a vane head opposite the vane foot. The vane head faces the rotor 103 and fixed to a mounting ring 140 of the stator 143.

Claims (12)

Component (1),
in particular high-temperature component,
that (1) has at least: a substrate (4) and at least in places at least one layer of graphene (7 ', 7'',7''', 7 ^IV , 7 ^V ). Component according to claim 1,
wherein the substrate (4) is metallic,
in particular has a nickel- or cobalt-based superalloy,
in particular, consists of it. Component claim 1 or 2,
in the graph (7 ') is present on or in the substrate (4),
in particular on the substrate (4),
in particular directly on the substrate (4). Component according to one or more of claims 1, 2 or 3,
wherein on the substrate (4) a layer (10),
in particular a metallic protective layer (10),
in particular an MCrAlX layer (10),
is available,
is present on the (10) or under the (10) graphs (7 "),
in particular directly on the layer (10) is present. Component according to one or more of claims 1, 2, 3 or 4,
in which a ceramic layer (13) is present on graphene (7 ''),
especially directly on graphene (7 '') is present. Component according to one or more of claims 1, 2, 3, 4 or 5,
in the graph (7 ''') directly on a ceramic layer (13),
in particular directly on an outermost ceramic layer (13) is present. Component according to one or more of the preceding claims,
in which graphene (7 ^IV , 7 ^V ) is present within at least one metallic (10) or ceramic layer (13). Component according to one or more of the preceding claims,
in the graph (7 ', 7'',7''', 7 ^IV , 7 ^V ) only locally in or on the substrate (4) or only locally in or on at least one layer (10, 13) is present. Method of manufacturing a component (1) according to claim 1, 2, 3, 4, 5, 6, 7 or 8,
at least one location,
in particular, only one layer of graphene (7 ', 7'',7''', 7 ^IV , 7 ^V ) on or in the substrate (4) or on or in at least one layer (10, 13) or introduced becomes. Method according to claim 9,
in which graphene (7 ', 7'',7''', 7 ^IV , 7 ^V ) is grown directly on the substrate (4) or on or in the layers (7, 13). Method according to one or both of claims 9 or 10,
in which a layer of graphene (7 ', 7 ^IV , 7 ^V ) is introduced into a layer (10, 13) and thus mechanically connected. Method according to one or more of claims 9, 10 or 11,
in which a layer of graphene (7 ', 7'',7''', 7 ^IV , 7 ^V ) is placed on a layer (10, 13) or a substrate (4) and overcoated, in particular over-injected, so that it is mechanically connected to the layer (10, 13).

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