Layer system and process for its production

0001The invention relates to a layer system according to the preamble of claim 1 and method for producing a Layer system according to the preamble of claims 18 and 19th

0002Components for high temperatures are nowadays usually provided with protective layers. This may metallic corrosion protection layers (MCrAlX layers) or ceramic thermal barrier coatings and coating systems with metallic corrosion protection coatings and ceramic be thermal barrier coatings. Used as a coating method for these coatings one plasma-based powder spraying process because of their comparatively high efficiency. The connection of such layers to the substrate is carried out by mechanical clamping and subsequent diffusion heat treatment. Occasionally it can in high stress areas or unfavorable, ie particularly stressed at high mechanical Set the component to film peeling come in operation. The flaking of the layer during operation leads to damage of the base material, so that the Component life is substantially reduced.

0003It is therefore an object of the invention, a layer system and show possible method for producing a layer system, the better connectivity of a protective layer on a comprising substrate and / or layers to one another.

0004The object is achieved by a layer system as of claim 1 and by a method for producing a Layer system according to the claims 18 and 19th

0005The layer system according to the invention comprises separately generated Anchoring means on which the very strong connection to Substrate or below it arranged on a on the substrate have layer and on another manner than the attached to the substrate layer or the other layer are.

0006The compared to the existing layer bonding (eg stapling by surface roughness) stronger links the anchoring means for example, by a melting metallurgical bond in a separate process is produced. Thus, further the cost and economic plasma spraying method can be used to the layer applied.

0007In the dependent claims are further advantageous measures listed. The measures listed in the subclaims can in advantageously be combined.

0008Show it<dl tsize="16" compact="compact"><dt>figure 1</dt><dd>a layer system according to the prior Technology,</dd><dt>2, 6, 7, 8</dt><dd>inventively constructed layer systems,</dd><dt>figure 3</dt><dd>a top perspective view of a invention designed according to the layer system,</dd><dt>figure 4</dt><dd>Method steps of the invention process,</dd><dt>figure 5</dt><dd>Process steps of another invention process,</dd><dt>figure 9</dt><dd>a gas turbine and</dd><dt>figure 10</dt><dd>a combustion chamber.</dd></dl>

00091 shows a layer system according to the prior art. The layer system comprises a substrate 4th The substrate 4 may be metallic or ceramic, and is The case of gas turbine components, in particular from an iron-, nickel- or cobalt-based super alloy.

0010On the substrate 4, at least one layer 7, 9 (in Fig. 6, 7, 8, two layers) are present. This can be a metallic and / or ceramic layer 7, be. 9

0011For turbine blades 120, 130 (Fig. 9), for example, on the substrate 4, a metallic corrosion protective layer 7 (Fig. 6, 7, 8) of the MCrAlX type is applied, whereupon in addition even an external, such as a ceramic Thermal insulation layer 9 (Fig. 6, 7, 8) is applied.

0012The connection of the intermediate layer 7 on the substrate 4 or the layers 7, 9 with each other is based on the previous State of the art solely by mechanical clamping (Surface roughness) on the underlying surface and subsequent Diffusion heat treatment.

00132 shows from figure 1, an inventive Layer system. 1 On the surface 5 of the substrate 4 are anchoring means 10, 13 available. The anchoring means 10, 13 have a Type of connection to the surface 5, which increased Connection power (more precisely, force / per contact area) to the Surface 5 with respect to the type of connection of the intermediate layer 7 results to the surface. 5

0014The anchoring means 10, 13 are, for example, by a suitably guided laser welding process smelting attached to the substrate. 4 It is also conceivable that the layer 7 in certain Ask applied by laser cladding (laser powder coating) is thus forming anchoring means 10,. 13 The anchoring means 10, 13 can also be molded or are produced during casting of the substrate 4 with. The anchoring means 10, 13 provide adhesion bridges for the anchoring means 10, 13 surrounding layer 7, 9 represent. The anchoring means 10 may extend from the surface 5 of the substrate 4 to the outer surface 8 of the Interlayer 7 extend or they are represented by the 13 Layer 7 is covered, so that the anchoring means 13, do not extend up to the surface 8 of the layer 7, ie within the layer 7, 9 are arranged ending. there they extend at least 13 up to 10%, 20%, 30%, 40% the thickness of the layer 7, 9 in the layer 7 9th

0015The anchoring means 10, 13 are, for example, only locally, thus locally (Fig. 3) on the substrate 4 or the Layer 7 is present, namely where the mechanical load is greatest. This is for example the area of ​​the leading edge of a Turbine blade 120, 130. The remaining airfoil would then have no anchoring means.

0016Figure 3 shows a plan view of a surface 8 of a Layer. 7 indicated by dashed lines are the anchoring means 13, the do not extend to the surface 8 of the layer. 7 The Anchoring means 10, 13 can be different on the surface 5 Geometries such as circles, topstitching (ie they are elongate and intersect), waveforms parallel runways and Combinations thereof.

0017Figure 6 shows a further inventively constituted Layer system. 1 The layer system 1 comprises a substrate 4 and two Layers 7, 9th

0018The intermediate layer 7 is for example a metallic MCrAlX layer and the outer layer 9 is, for example, a ceramic thermal barrier layer 9 on the interlayer 7th

0019Anchoring means 10, 13 are both in the intermediate layer 7 as also present in the outer layer. 9

0020However, the intermediate layer 7 has no anchoring means 10, 13 in the context of the present invention (FIG. 8). Likewise, the anchoring means can only in the intermediate layer 7 be present (Fig. 7).

0021The anchoring means 10, 13 in the layers 7, 9 may starting from the surface 5, 8 of the substrate 4 and the intermediate layer 7 to the outer surface 8, 16 of the Layer 7, 9 extend or through the layers 7, 9 covered, so that the anchoring means 13 does not extend up to the surface 8, 16 of the layers 7, 9 extend.

0022The anchoring means 10, 13 in the intermediate layer 7 improve the connection of the intermediate layer 7 to the substrate . 4 The material of the anchoring means 10 of the layer 7 for example also be selected so that an improved Adhesion of the outer layer 9 on the anchoring means 10 results (Fig. 7). For example, the material the anchoring means 10 in the intermediate layer 7 ceramically be, whereby the ceramic thermal barrier coating 9 better with the anchoring means 10, extending to the surface 8 the intermediate layer 7 extend, to connect or Anchoring means 10 serve as a growth seed, in particular the epitaxial growth, the coating of the intermediate layer 7 with the ceramic material of the outer layer. 9

0023The material composition of the anchoring means 10, 13 in the layers 7, 9 is suitably selected depending on requirements.

0024The anchoring means 10, 13 are thermally, in particular in and / or mechanically highly stressed areas exist.

0025The layer system 1 is, for example, a component of a gas-100 (Fig. 9) (also aircraft turbine) or steam turbine. thermal highly stressed components of the turbines have such a Layer system, such as turbine blades 120, 130, linings 155 a combustion chamber 110 and other housing parts, along the flow path of a hot steam or hot gas are located.

0026The layer system 1 may indicate a newly produced component be applied, as well as on components that use after the be refurbished (refurbishment). Here are the Components previously exempt from degraded layers, cracks possibly repaired and there is a renewed coating of the substrate. 4

00277 shows a further embodiment of an inventive Layer system. 1 In this layer system 1, the anchoring means 10, 13 only present in the intermediate layer. 7 On the intermediate layer 7, the outer layer 9 is present. A contact surface the anchoring means 10 improves on the surface 8 the adhesion of the outer layer 9 over a comparable Area of ​​contact with the intermediate layer 7. This For example, achieved by the fact that the contact surfaces 10 form of the anchoring means to the surface 8 nucleation points for example, epitaxial growth of an outer Layer 9 on the interlayer 7th Even without intermediate layer 7 (Fig. 4, 5, right side) is an improved Layer system 1 achieved in that the anchoring means 10, 13 to an improved connection of the outer Layer 9 lead to the substrate. 4

0028Figure 8 shows a further embodiment of the invention Layer system. 1 In this embodiment, the anchoring means 10, No 13 only in the outer layer 9, ie they are on the intermediate layer 7 is present that to better connect the outer layer 9 to the underlying intermediate layer 7 lead. The anchoring means 10, 13 are then applied to the surface 8 the intermediate layer 7 bonded.

0029Figure 4 shows an example of process steps of an inventive Method for producing a layer system 1. In a first step, on the substrate 4 or to a already present on the substrate layer in a known manner and, the at least one layer 7, 9 applied.

0030The layer 7, 9, 16 with a laser or an electron beam gun 16 treated that an appropriate laser or Electron beam 19 emits. Through this type of treatment the material of the layer 7, 9 to the surface 5, 8 of the substrate 4 or the interlayer 7 out locally converted, for example, melted, so that a melting metallurgical bonding material from the layer 7, 9 to the substrate 4 or a previously applied thereon Layer results. With this method, anchoring means 10 produced which to extend from the surface 5, 8 up Surface 8, 16 of the layer 7, 9 extend.

0031The anchoring means 10 are, for example, columnar formed and can also be curved concavely or convexly running (FIG. 7).

00325 shows another example according to the invention Process.

0033In a first step, on the substrate 4 or the Layer 7 first the anchoring means 10, 13 is applied, So generated separately. This can be in a variety of Manner, such as by a suitably guided laser welding process or laser cladding done. The anchoring means 10, 13 have a very strong, in particular melt-metallurgy attachment to the surface 5, 8 on the substrate 4 or the interlayer 7th

0034However, the anchoring means 10, 13 can already even at have been generated the production of the substrate 4, for example by a casting process.

0035In a subsequent process, the layer 7, 9 is applied, wherein the anchoring means 10, 13 of the material the layer 7, 9 are enclosed and adhesion bridges the layer 7, 9 represent.

0036The material of the anchoring means 10, 13 may be equal to the Material of the layer 7, 9, equal to the material of the substrate 4 or equal to the material of the following layer or also have a different material composition. The material the anchoring means 10, 13 in the layer 7 must not necessarily equal to the material of the substrate. 4

00379 shows a gas turbine 100 in a longitudinal partial section. The gas turbine 100 internally comprises about a rotation axis 102 rotatably mounted rotor 103, also known as the turbine rotor referred to as. Along the rotor 103 consecutive an intake manifold 104, a compressor 105, a, for example, toroidal combustion chamber 110, in particular annular combustion chamber 106, with a plurality of coaxially arranged burners 107, a turbine 108 and the exhaust manifold 109. The ring combustion chamber 106 communicates with an eg annular Hot gas channel 111. There, for example, form four successive turbine stages 112 form the turbine 108th Each turbine stage 112 is formed from two blade rings. In the direction of flow of a working medium 113, seen following one of the hot gas passage 111 a row of guide vanes 115 Rotor blades 120 formed series 125th

0038The guide vanes 130 are secured to the stator 143, whereas the rotor blades 120 of a row 125 by means of a Turbine disk 133 are attached to the rotor 103rd To the Rotor is coupled 103 A generator or a working machine (not shown).

0039During operation of the gas turbine 100 is from the compressor 105 104 135 air sucked through the intake and compressed. The provided at the turbine-side end of the compressor 105 compressed air is passed to the burners 107 and there mixed with a fuel. The mixture then, forming the working medium 113 in the combustion chamber 110 burned. From there, the working medium flows 113 along the hot gas channel 111 past the guide vanes 130 and the rotor blades 120. At the rotor blades 120 laid The working medium 113, transferring its momentum, so that the rotor blades 120 drive the rotor 103 and the coupled to it working machine.

0040subject to the hot working medium 113 components exposed thermal during operation of the gas turbine 100 Loads. The guide vanes 130 and rotor blades 120 of seen in the flow direction of the working medium 113, first Turbine stage 112, in addition to the annular combustion chamber 106 heat shield bricks most thermally stressed. To the temperatures prevailing there withstand these are cooled by a coolant. can also the blades 120, 130 may have coatings against corrosion (MCrAlX; M = Fe, Co, Ni, X = Y, rare earths) and heat (thermal barrier coating, For example, ZrO₂, Y₂O₄-ZrO₂) Exhibit.

0041The guide vane 130 has a the inner housing 138 of Turbine 108 facing vane root (not shown here) and a guide vane head's opposite Vane root. The guide vane rotor 103 facing and on a fastening ring 140 of the stator 143 set.

004210 shows a combustion chamber 110 of a gas turbine 100th The combustion chamber 110 is, for example, as so-called annular combustion chamber configured in which a plurality of circumferentially arranged around the turbine shaft 103 Burners 102 open into a common combustion chamber space. For this, the combustion chamber 110 is in its entirety as an annular Structure designed that around the turbine shaft 103 is positioned around.

0043is to achieve a relatively high efficiency, The combustion chamber 110 for a relatively high temperature the working medium M designed about 1000 ° C to 1600 ° C. Around even under these unfavorable for the materials operating parameters To allow a relatively long operating time, the combustion chamber wall 153 on its side facing the working medium M-facing side with a from heat shield elements 155 inner lining formed provided. Each heat shield element 155 is equipped with a particularly heat-resistant Protective layer or is made from high temperature manufactured material. Due to the high temperatures inside the combustion chamber 110, is for the Heat shield elements 155 or for their holding elements a Cooling system provided.