The present invention relates to a device for the partial coating of a component, particularly for the coating of components of a gas turbine or an aircraft engine. The invention further relates to a method for the partial coating of a component, particularly for the coating of components of a gas turbine or an aircraft engine.
Components, in particular components of a gas turbine or an aircraft engine, which are subject to erosive stress, are generally coated with layers, in particular erosion-resistant layers. However, these protective layers may have a negative impact on the fatigue strength and/or service life of these types of components. This applies particularly in the case of ceramic hard material layers, which serve in particular to protect against erosion, because there is a risk that incipient cracks in the ceramic layer will rapidly run into the base material of the component and lead to premature failure of the component. In particular these incipient cracks occur in layer regions subject to high component stress, such as for example, those with high tensile strain. The possibility that such incipient cracks will form in coated component regions subject to high stress, particularly high mechanical stress, therefore has a negative impact on the quality and the service life of the corresponding component in this region.
It is therefore the object of the present invention to make available a generic device for the partial coating of a component, particularly for the coating of components of a gas turbine or an aircraft engine, which makes a reliable and quick coating of the component possible while taking critical component regions into account, i.e., regions that are subject to high component stress, in particular mechanical stress.
It is further the object of the present invention to make available a generic method for the partial coating of a component, particularly for the coating of components of a gas turbine or an aircraft engine, which makes a reliable and quick coating of the component possible while taking critical component regions into account, i.e., regions that are subject to high component stress, in particular mechanical stress.
A device according to the invention for the partial coating of a component, particularly for the coating of components of a gas turbine or an aircraft engine comprises at least one base receptacle for at least partially receiving the component and a first partial region of the component not to be coated, and at least one plate-shaped cover that can be positioned in the base receptacle, and wherein the cover comprises at least one recess or opening for a second partial region of the component to be coated to pass through and the shape of the recess or opening corresponds to the profile of the component in the region between the partial region not to be coated and the partial region to be coated. The device according to the invention makes it possible for critical component regions, i.e., regions subject to high component stress, particularly high mechanical stress, to be masked or covered so that these regions are not coated. As a result, the development of incipient cracks from a coating in the base material of the component which could lead to a premature failure of the component as a whole is avoided in these critical partial regions of the component. The partial regions of the component that are not covered or masked may be coated reliably and quickly. In designing the plate-like cover and the corresponding recess or opening for the partial region to be coated to pass through, knowledge about the stress pattern of the component, particularly a mechanical stress pattern, is taken into account so that there may be an optimized distribution between the coated and non-coated partial regions of the component.
In advantageous embodiments of the device according to the invention, the cover is configured to be flat, uneven or arched, or straight, curved or polygonal in cross section. Other embodiments of the cover are also conceivable, wherein the design of the cover is always based on an optimized separation between the partial regions of the component to be coated and those not to be coated with knowledge of the component stress. In addition, it is possible for the cover to be made of metal, a metal alloy, ceramic, glass or plastic, in particular temperature-resistant plastic.
In a further advantageous embodiment of the device according to the invention, the base receptacle has corresponding support regions or projections for positioning, in particular for positioning the height of the cover. This makes it possible for the base receptacle to be adapted to the separation required in the respective individual case of the partial regions of the component to be coated and those not to be coated.
In another advantageous embodiment of the device according to the invention, the base receptacle is configured to be displaceable for changing the position of the cover in relation to the component. This makes it possible to make a change in the position of the cover relative to the component to be coated, for example during the coating process. As a result, it is possible in an advantageous manner to vary the layer thickness of the coating. In addition, it is possible, particularly in the case of multiple layers, to apply different multilayers on the component.
In another advantageous embodiment of the device according to the invention, the device has at least one fixing device for detachably fixing the cover on the base body. In this case, the fixing device may be configured to be sleeve-like with at least one passage opening for the second partial region of the component to be coated to pass through.
In a further advantageous embodiment of the device according to the invention, the partial coating of the component is carried out by means of a physical vapor deposition method (PVD).
In another advantageous embodiment of the invention, the coating is a protective layer, in particular an erosion-resistant layer. In this case, the protective layer may be made in particular of a hard ceramic material and/or a metal or a metal alloy. Titanium nitride for example may be used as the hard ceramic material. The protective layer in this case may be made of several layers, wherein for example, a layer is structured in an alternating manner of a hard ceramic material and a metal or a metal alloy.
In further advantageous embodiments of the device according to the invention, the component is a blade of a rotor of a gas turbine, wherein the blade may be in particular part of an integral rotor design (BLISK or BLING). A method according to the invention for the partial coating of a component, particularly for the coating of components of a gas turbine or an aircraft engine, is comprised of the following steps:
a) Receiving and positioning the component in a base receptacle;
b) Covering a partial region of the component not to be coated by means of a cover, wherein a partial region of the component to be coated is fed through a recess or opening in the cover and the shape of the recess or opening corresponds to the profile of the component in the region between the partial region not to be coated and the partial region to be coated; and
c) Coating the partial region of the component to be coated.
It is advantageously possible through the method according to the invention for critical component regions, i.e., regions subject to high component stress, in particular mechanical stress, to be masked or covered so that there is no coating in these partial regions of the component. As a result, a formation of cracks initiated by the coating, which may extend into the region of the base material of the component, is prevented. In addition, a reliable and rapid coating of those partial regions of the component that lie outside of the cited critical component regions is possible. The design of the cover in this case takes into account the distribution of the component stress, wherein the partial regions that are subject to high component stress are reliably masked by the cover. In an advantageous embodiment of the method according to the invention, prior to the process step c), a fixing of the base receptacle with the cover is carried out by means of a fixing device. In addition, it is possible for the fixing device to be configured to be sleeve-like with at least one passage opening for the second partial region of the component to be coated to pass through. These process steps guarantee a secure positioning of the cover in the base receptacle as well as a secure fastening of the to-be-coated component in the base receptacle.
In another advantageous embodiment of the method according to the invention, the base receptacle is configured to be displaceable for changing the position of the cover in relation to the component, wherein a change in the position of the cover is made after and/or during the coating according to process step c). Because of the possibility of changing the position of the cover in relation to the component it is possible for different layer thicknesses to be applied to the component. In addition, it is possible, for example in the case of multilayered coatings, for the layer regions to be applied on the component in a different layer sequence. Furthermore, this makes a coating with a homogeneous layer run-out possible.
In a further advantageous embodiment of the method according to the invention, the partial coating of the component is carried out by means of a physical vapor deposition method (PVD).
In another advantageous embodiment of the method according to the invention, a protective layer, in particular an erosion-resistant layer, is formed by the coating according to process step c). The protective layer in this case may be made of a hard ceramic material such as for example, TiN and/or a metal or a metal alloy. The protective layer may also be configured to be multilayered, wherein for example, hard ceramic materials and metallic materials are formed in an alternating manner.
A device or a method as described in the foregoing is used in particular for producing and repairing engine components, particularly for producing, repairing and coating integral rotor designs (BLISK or BLING).
A component of a gas turbine or an aircraft engine according to the invention is produced in accordance with a method according to the invention described in the foregoing and/or by means of a device according to the invention described in the foregoing. In this case, the component may be a blade of a rotor of a gas turbine or a blade as part of an integral rotor design (BLISK or BLING).
Additional advantages, features and details of the invention are disclosed in the following description of two graphically depicted exemplary embodiments.
Number | Date | Country | Kind |
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10 2008 011 242.9 | Feb 2008 | DE | national |
This application claims the priority of International Application No. PCT/DE2009/000153, filed Feb. 4, 2009, and German Patent Document No. 10 2008 011 242.9, filed Feb. 14, 2008, the disclosures of which are expressly incorporated by reference herein.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE2009/000153 | 2/4/2009 | WO | 00 | 8/13/2010 |