METHOD FOR ADDITIVE MANUFACTURING BY MEANS OF A POROUS AUXILIARY STRUCTURE, COMPONENT AND DEVICE

Abstract

A method for the additive manufacturing of a component includes: the additive building up of a structure from a base material for the component by an additive manufacturing method; the introduction, during the additive building up of the structure, of a porous auxiliary structure into an interior of the structure to define a functional area for the component in the interior; and the removing, in particular melting, of the porous auxiliary structure from the functional area by heating the auxiliary structure so that the functional area no longer has the auxiliary structure. A component is produced in accordance with the method and a corresponding device.

Claims

1.-11. (canceled)

12. A method for additive manufacturing of a component, comprising: additive building up of a structure from a base material for the component by an additive manufacturing method, introducing a porous auxiliary structure consisting of a metal foam into an interior of the structure during the additive building up of the structure in order to define a functional region for the component in the interior, wherein the additive building up of the structure and/or the introducing of the porous auxiliary structure are or is carried out by laser deposition welding or micro cladding, wherein, to form the porous auxiliary structure, a metallic material for the porous auxiliary structure is mixed with a pore former, and wherein the corresponding mixture for forming the porous auxiliary structure is heated above a melting point of the metallic material, and the pore former is evaporated, and detaching the porous auxiliary structure from the functional region by heating the porous auxiliary structure, with a result that the functional region is freed from the porous auxiliary structure.

13. The method as claimed in claim 12, wherein parts of the structure and of the porous auxiliary structure are alternately built up in layers.

14. The method as claimed in claim 12, wherein the porous auxiliary structure is introduced into the interior in such a way that the porous auxiliary structure supports the structure for the component.

15. The method as claimed in claim 12, wherein a material of the porous auxiliary structure remains in the interior of the component.

16. The method as claimed in claim 12, wherein the structure for the component is built up in such a way that the component has at least one inlet and/or outlet which is fluidically connected to the interior, and wherein the structure is formed in such a way that the porous auxiliary structure is removeable in a simple manner from the interior by melting.

17. A component which is produced or can be produced by the method as claimed in claim 12, wherein the component is a high temperature resistant and/or highly heatproof component for use in a turbomachine, wherein the functional region is provided to be traversed by a fluid for cooling, and wherein the functional region is at least partially defined by a material.

18. A device for the additive manufacturing of a component by the method as claimed in claim 12, the device comprising: a reservoir for separate storage of a base material for the component, of a material and of a further material, a processing head which is connected to the reservoir, wherein the processing head is further designed for guiding a welding beam, and in such a way as to selectively deposit the base material, and/or the further material on a processing surface and to melt said materials, wherein the device is a beam welding device for laser deposition welding or micro cladding, and a delivery device for selectively delivering the base material, the material of the porous auxiliary structure, and the further material into the processing head.

19. The device as claimed in claim 18, further comprising: a heating device which is designed to heat a structure of the component to a temperature of at least 800 C.

20. The device as claimed in claim 19, wherein the heating device is an inductive heating device.

21. The method as claimed in claim 12, wherein the pore former is a metal hydride.

22. The method as claimed in claim 12, wherein the detaching comprises melting the porous auxiliary structure from the functional region by heating the porous auxiliary structure.

23. The component as claimed in claim 17, wherein the functional region is at least partially defined by a metallic material.

24. The device as claimed in claim 18, wherein the material is a metallic material.

25. The device as claimed in claim 18, wherein the welding beam is a laser or electron beam.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Further details of the invention will be described below with reference to the figures.

[0047] FIG. 1 schematically shows a device according to the invention and indicates, by way of a cross-sectional view of a component, method steps of a method carried out according to the invention by the device.

[0048] FIG. 2 schematically shows an auxiliary structure for the additive building-up of the component.

[0049] FIG. 3 schematically indicates a further method step of the method.

[0050] FIG. 4 shows by way of example a component produced according to the method.

[0051] FIG. 5 shows a simplified flow diagram which indicates method steps according to the invention.

DETAILED DESCRIPTION OF INVENTION

[0052] In the exemplary embodiments and figures, identical or identically acting elements can each be provided with the same reference signs. The illustrated elements and their size ratios relative to one another are, in principle, not to be considered as true to scale; rather, for better illustratability and/or for better comprehension, individual elements may be illustrated as exaggeratedly thick or largely dimensioned.

[0053] FIG. 1, in the upper part of the illustration, indicates a device 20 according to the invention in a simplified manner. In the lower part of the illustration there is schematically illustrated the additive building-up of a component in a cross-sectional view as part of a method according to the invention. In particular a structure 1 for the component 100 (cf. FIG. 3 below) according to the invention is indicated by way of example by means of the device 20. The method step of the additive building-up of the structure 1 is further designated in a simplified manner in the flow diagram of FIG. 5 by the reference sign a).

[0054] The component 100 is advantageously a component consisting of a nickel-based alloy or superalloy or another, in particular highly heatproof or high-temperature-resistant, component, in particular for use in a turbomachine, such as a gas turbine.

[0055] The device 20 is basically a beam welding and/or beam melting device, in particular a device for laser deposition welding, particularly advantageously for laser powder deposition welding or micro cladding.

[0056] The device 20 comprises a reservoir 21. The reservoir 21 advantageously holds or stores pulverulent starting and auxiliary materials for the additive building-up of the structure 1 by means of the device 20. The reservoir 21 can, as illustrated, be subdivided into three separate or mutually separated sub-reservoirs 21a, 21b and 21c, wherein each sub-reservoir contains only one material. Without limiting the generality, the sub-reservoir 21a can, for example, hold a base material for the structure 1 or the component 100.

[0057] For example, the sub-reservoir 21b holds or contains an, advantageously metallic, auxiliary material 3. The auxiliary material 3 can be an additive material which is of the same kind as or similar kind to the base material for the structure 1. For example, both materials, i.e. the base material and the auxiliary material 3, can be metallic. However, the respective melting points are advantageously different. The melting point of the auxiliary material 3 is advantageously lower than the melting point of the base material under standard pressure conditions.

[0058] The sub-reservoir 21c contains a further material, for example. The further material can likewise be an auxiliary material and/or a functional material (not explicitly indicated). In particular, the functional or further material is a pore former with which metallic foams and/or porous structures can be produced in interaction with the auxiliary material 3. The functional or further material can, for example, likewise be pulverulent or else liquid.

[0059] The device 20 further comprises a processing head 23 which is schematically indicated in FIG. 1. The processing head 23 is advantageously equipped with an optics 26 for guiding a welding beam 25, for example a laser or electron beam. The processing head 23 is further connected to the reservoir 21, to be more precise to each of the sub-reservoirs 21a, 21b, 21c, with the result that material can be delivered from a corresponding reservoir into the processing head or fed thereto (for the additive building-up). This is advantageously made possible by means of a delivery device 22, or respectively separate delivery devices 22 for each sub-reservoir, wherein the corresponding material can be delivered into the processing head 23 selectively and independently of the delivery of another material. This can be achieved by means known to a person skilled in the art, for example conventional powder-delivering methods, in particular pneumatic devices, pumps or other means.

[0060] The delivery device(s) 22, the reservoir(s) 21, under certain circumstances together with a corresponding controller, advantageously make it possible for mutually separated fully automatically or semiautomatically controlled delivery paths to be configured which feed the described materials for the additive building-up of the component 100 selectively via the powder nozzle 24 to a melt pool.

[0061] The materials for the additive building-up are advantageously first mixed in the processing head 23 and then, analogously to conventional laser deposition welding, deposited by a powder nozzle 24 on a processing surface or on a substrate (cf. reference sign 6) and melted by means of the welding beam 25 for building-up purposes.

[0062] In FIG. 1, the structure 1 for the component 100 is shown as being already (virtually) completely built up on the substrate 6.

[0063] In other words, the structure 1 has, according to the described method, been built up, advantageously in layers, along a building-up direction AB by means of the device 20. Here, the dashed horizontal lines in the lower region of the structure 1 in FIG. 1 indicate the individual layers. The stated layers may, for example, already have been depicted or been present in a data model (for example CAD and/or CAM model) for the construction of the component (slicing) relative to its structure 1.

[0064] According to the method presented (cf. also FIG. 5), the structure 1 is or has been built up on the substrate 6 from a corresponding pulverulent base material by means of laser deposition welding.

[0065] During the additive building-up, an auxiliary structure 2, advantageously consisting of a metal foam, is introduced or built up in an interior, designated by reference sign I, of the structure 1 or of the component 100. The introduction of the auxiliary structure 2 is indicated further below in FIG. 5 by the reference sign b), wherein the stated method step can occur, for example, simultaneously or in layers with the building-up of the structure 1 and also subsequently thereto.

[0066] There is thereby advantageously defined or delimited a functional region FB which later becomes necessary for the component or its function during operation. This can occur (additively) in layers just like the actual building-up of the structure 1, wherein the material has to be changed in layers for the corresponding building-up of the layer, under certain circumstances via a corresponding controller and the corresponding activation of the powder-delivering devices 22. For this purpose, there can be required overall in particular a particularly rapid response of the powder nozzle 24, of the delivery devices 22 and/or of the processing head 23.

[0067] Alternatively, it is also possible at first for a plurality of layers of the structure 1 to be built up additively virtually three-dimensionally and for a thus defined interior or inner region I subsequently to be filled with the auxiliary material 3, for example up to the time at which an overhang 8 must be produced in the structure.

[0068] It can be seen from the checkered illustration of the auxiliary structure 2 that what is concerned here is a porous material which has, for example, a porosity of 50% or more. The auxiliary structure 2 has in particular the purpose of supporting the actual structure 1 for the component above the inner region I for the required dimensional stability during the additive manufacturing. The porosity can be selected accordingly and can be, for example, 30%, 40%, 60%, 70% or more.

[0069] FIG. 2 shows an exemplary structure of the stated auxiliary structure with a porosity which is expedient therefor according to the present invention. According to the illustration of FIG. 2, the porosity can be 50%.

[0070] The porous auxiliary structure 2 is in particular formed or built up by virtue of the fact that the stated, in particular metallic, auxiliary material 3 is mixed with the pore former, for example a metal hydride, in the processing head 23 and the corresponding mixture for forming the auxiliary structure 2 is heated above the melting point of the auxiliary material 3. Here, the pore former advantageously evaporates and produces the desired porosity of the auxiliary structure 2. In particular, the porosity can be set the mixing ratio of auxiliary material 3 and pore former and by the correspondingly introduced thermal energy (laser power).

[0071] The stated auxiliary material 3 is advantageously a solder material, in particular a high-temperature solder, which can be detached and liquefied again in a subsequent temperature step of the described method (see FIG. 5). The stated high-temperature solder can contain Cu, Co or Ni.

[0072] According to the illustration of FIG. 2 (cf. lower region), the component is built up in such a way that an arc-like auxiliary structure 2 has been introduced into an inner region I in a simple rectangular or parallelepipedal geometry of the structure 1. The auxiliary structure 2, and advantageously corresponding inner region I, have, moreover, horizontally extending portions or arms which define corresponding overhangs of the structure 1.

[0073] The interior I or the auxiliary structure 2 is expediently covered again with the actual base material (cf. upper region of the component 100 in FIG. 1) in a subsequent building-up phase until completion.

[0074] As a departure from the illustration of FIG. 1, it is possible for the component 100, its structure 1 and/or the auxiliary structure 2 introduced into the inner region I or the fusion region FB to have any individually desired shape or geometry, for example a shape already predetermined by the construction of the component. In particular, the inner region I, which, according to the present invention, is occupied temporarily, i.e. advantageously completely by the auxiliary structure 2 during the manufacturing, can be provided for a cooling duct structure (not explicitly indicated) via which the component 100 can be expediently traversed during operation by a cooling fluid for cooling. For this purpose, the structure 1 is advantageously built up in such a way that a fluid inlet and/or a corresponding outlet are or is provided for the component.

[0075] The method further comprises the detachment or removal (cf. method step c) in FIG. 5), in particular the melting or melting-out of the porous material of the auxiliary structure from the fusion region FB by heating the auxiliary structure, in particular after the structure 1 has been completely built up, with the result that the functional region FB is freed from the auxiliary structure.

[0076] For this purpose, the device 20 can have a heating device 27 which is likewise schematically indicated in the lower region of FIG. 1. The heating device 27 can be an inductive device, for example an induction furnace, in order to heat the structure 1, but in particular the auxiliary structure 2, to expediently high temperatures after the described additive building-up, for example in such a way that the auxiliary structure can be melted down. Temperatures of above 700 C., advantageously of about 800 C., particularly advantageously of above 900 C. or more, are advantageously reached for removing the auxiliary structure from the functional region FB.

[0077] Alternatively, the heating device can be a device which is separate from the described device 20.

[0078] FIG. 3 shows the component 100 or its structure 1, wherein, by virtue of the described removal, in particular by means of a high-temperature treatment or high-temperature soldering, the auxiliary structure 3 has been removed from the functional region FB by liquefaction (cf. method steps c) in FIG. 5). Correspondingly, FIG. 3 advantageously shows a complete or substantially completely manufactured state of the component 100.

[0079] The described melting down of the auxiliary structure 2 means that it necessarily loses its dimensional stability, its original volume and also its supporting action for the structure 1. The melted-down material of the auxiliary structure 2 can remain, for example, on or in portions of the inner region I. Accordingly, the functional region FB is advantageously completely arranged in the inner region and/or constitutes a subregion of the inner region I.

[0080] The greater the porosity, the greater can subsequently be the functional region FB, since more volume (gas volume) is available for forming the hollow or functional region FB on account of the greater porosity.

[0081] It is indicated in particular by the dashed lines in FIG. 3 that the, in particular metallic, auxiliary material 3, i.e. the melted-down material of the auxiliary structure, remains on inner walls of the structure 1 or of the inner region I or accumulates there. Alternatively or in addition, the auxiliary material 3 can be at least partially received in regions pockets provided therefor (likewise dashed and indicated by reference sign 4 in FIG. 3), into which regions said material flows, for example, after liquefaction under the influence of gravitation.

[0082] Alternatively, the complete building-up of the structure 1 for the component 100 can be carried out according to the invention in such a way that the component 100 has at least one inlet and/or outlet 4 which is fluidically connected to the interior I. The auxiliary material can then advantageously likewise be removed from the inner region I through the inlets and/or outlets 4 provided in the structure, and thus an even greater volume for the fusion region can be made available.

[0083] The stated inlet and/or outlet 4 can be provided at the position(s) of the pockets or receiving regions.

[0084] FIG. 4 shows, merely as an exemplary embodiment, a turbine blade, for example a guide blade or rotor blade of a gas turbine, as component 100. At the tip of the component 100 there is shown an inner region or cavity which constitutes the described functional region FB. In this context, the turbine blade shown can be provided with an inner cooling duct or cavity using the described method, with the result that the blade can be expediently cooled, for example, for an operation of the gas turbine.

[0085] As an alternative to the turbine blade shown, the component 100 can be, for example, another component which is used in the hot-gas path of a gas turbine, for example a burner component or a part of a combustion chamber wall of the turbine.

[0086] Although not explicitly shown in the presently described figures, the described method and/or the corresponding component can be characterized by the additive deposition of further materials, for example oxidation protection layers (MCrAlX) and/or thermal insulation layers.

[0087] Furthermore, it is possible within the scope of the described inventionas an alternative to the described welding methodsto use further coating methods, such as, for example, electron beam evaporation (EB-PVD) or atmospheric plasma spraying (APS), LPPS, VPS or CVD, insofar as the described concept according to the invention with metallic foam as porous auxiliary structure can be applied thereto.

[0088] The invention is not limited by the description on the basis of the exemplary embodiments to said embodiments, but encompasses any novel feature and any combination of features. This includes, in particular, any combination of features in the patent claims, even if this feature or this combination itself is not explicitly specified in the patent claims or exemplary embodiments.