Method for the partial construction or repair of a component

Abstract

The present application relates to a method for the partial construction or repair of a component (1), in particular a turbomachine component (2, 3, 4), in which method: i) the component (1) is subjected to a protective gas atmosphere (6) at least in a working region (A), wherein the protective gas atmosphere (6) is doped with a mass fraction of at least 0.5% monosilane; ii) a metal application material (8) is applied to the component (1) in the working region (A), wherein the metal application material (8) is a matrix material (8.3) with embedded ceramic hard-material particles (8.4); and iii) the metal application material (8) is subjected, in the working region (A), to a working beam (10) generated by an energy source (9), in such a way that the matrix material (8.3) is liquefied and consequently integrally bonded to the component (1), wherein an aggregate state of the hard-material particles (8.4) of the application material (8) remains unchanged during the welding.

Description

[0001] METHOD FOR ASSEMBLING OR REPAIRING A COMPONENT PART IN PART

[0002] DESCRIPTION

[0003] Technical field

[0004] The present invention relates to a method for the section-by-section assembly or repair of a component.

[0005] State of the art

[0006] Turbomachinery typically consists of a number of components, which are subjected to high thermal and / or mechanical stress, at least in some sections.

[0007] These turbomachinery components must therefore be regularly inspected and maintained, especially in highly stressed areas. To reduce operating and maintenance costs for turbomachinery components, they are often repaired using material deposition processes, or new components are at least partially built up using these processes. A variety of material deposition manufacturing processes are known in industrial practice, particularly for the partial assembly or repair of turbomachinery components.

[0008] For example, manual methods are known in which, to restore the geometric integrity of highly stressed blade areas of individual guide and / or rotor blades of a blade grid or ring, a surface orthogonal to their stacking axis is often first created by material removal, usually by grinding, and then material is deposited by melting using manual or machine-guided cladding welding. Electrically generated arcs, plasma, or high-energy lasers are frequently used as energy sources for this, and the deposit material can be supplied in the form of powder or wire.

[0009] Laser cladding processes are increasingly being used for section-by-section assembly or repair. These processes allow for precise control of material deposition while maintaining a relatively small heat-affected zone. This reduces deformation and thermal stresses within the component, enabling targeted repairs or reinforcement of components within a specific work area without affecting the component as a whole. Laser-based processes also allow for high manufacturing accuracy combined with a high degree of geometric design freedom for components, which is particularly advantageous for turbomachinery components such as blade grids.

[0010] Description of the invention

[0011] The present invention is based on the technical problem of providing a particularly advantageous method for the section-by-section assembly or repair of a component, in particular a turbomachine component.

[0012] This is achieved according to the invention using the method according to claim 1. In this method, the component, at least in one working area, is exposed to a working jet in a protective gas atmosphere doped with a mass fraction of at least 0.5% monosilane, such that an applied metallic coating material is metallurgically bonded to the component. Preferably, the metallurgical bond is produced by cladding. According to the invention, a matrix material of the metallic coating material is liquefied without, however, changing the state of matter of the hard particles incorporated in the matrix material. In simplified terms, in the method according to the invention, the matrix material is welded to the component in the working area, but the hard particles contained in the coating material do not change their state of matter.

[0013] Laser cladding processes are, as mentioned at the beginning, well-known in themselves. However, material build-up or repair of titanium or superalloys commonly used in turbomachinery can only be achieved with considerable additional technical effort. These components typically require homogeneous preheating and maintaining a constant temperature during processing. Furthermore, if hard materials such as cubic bohmerite (CBN) are to be introduced into the component surface for the so-called "armoring" of individual component sections, these hard material particles can decompose due to the laser beams used.

[0014] The inventors have now recognized that the aforementioned problems can be solved with the method according to the invention, and in particular, time-consuming preheating and / or temperature control steps can be eliminated. For example, by doping the protective atmosphere with a mass fraction of at least 0.5% monosilane in the working area, the tendency of the turbomachine components to develop hot cracks can be reduced, resulting in an overall more efficient process. Preferably, the mass fraction of monosilane in the protective atmosphere is at least 1%, 2%, 3%, or 4% (possible upper limits for the mass fraction of monosilane in the protective gas atmosphere could, for example, be at most 10% or 5%).

[0015] For the purposes of the invention, the working area is understood to be a section of the component, for example a blade tip of a guide or running blade of a respective blade grid, e.g. an area with a surface area of ​​at most 75 cm². 2, preferably no more than 50 cm 2 , 30 cm 2 , 20 cm 2 or 10 cm 2 .

[0016] For the purposes of the invention, a matrix material is understood to be a component of a metallic composite material which, in its applied state, surrounds hard particles embedded in the material in a matrix-like manner. Preferably, this matrix material is melted without altering the state of matter of the hard particles contained therein. The hard particles can be formed monolithically from a single material, but can also, for example, be provided with an external coating.

[0017] Preferred embodiments are found in the dependent claims and the entire disclosure, whereby the description of the features does not always explicitly distinguish between process and apparatus aspects; in any case, the disclosure is to be read implicitly with regard to all claim categories. For example, if a specific procedural configuration is described, this is also to be read as referring to an apparatus that is set up to carry out a corresponding process.

[0018] In a preferred embodiment, the working beam exhibits electromagnetic radiation with a spectral component at wavelengths of 380 nm to 490 nm and / or 490 nm to 580 nm, preferably with no spectral components outside these wavelengths. For example, at least 70%, 80%, or 90% of the intensity of the electromagnetic radiation can lie in the aforementioned wavelength ranges; preferably, the entire intensity (100%) lies within these ranges. The use of electromagnetic radiation with a spectral component at the aforementioned wavelengths enables, for example, the reliable liquefaction and welding of the matrix material onto the component.However, at the wavelengths described above, the coupling of electromagnetic radiation into the hard material particles is prevented, so that they remain in the liquefied matrix material and thus in the bond formed between the component and the matrix material (after cooling) without changing their state of matter. In other words, the coupling of electromagnetic radiation into the hard material particles can be reduced or prevented.

[0019] A laser beam source, such as a CO2 laser, Nd:YAG laser, or Yb fiber laser (preferably with a multimode fiber), or a diode laser, is preferably used as the energy source. This laser beam source is configured to generate electromagnetic radiation with the aforementioned wavelength ranges. The laser beam source can be operated continuously, i.e., with a constant laser power over a certain period, or preferably in pulsed mode, i.e., exhibiting a certain fluctuation in laser power over a defined period. In this process, the energy source can advantageously be designed taking into account a defined energy-time ratio, from which a defined temperature-time ratio in the operating range results.

[0020] In a preferred embodiment, the coating material is applied to the component in the working area as a preformed hard material carrier film. This is a film-like matrix material containing embedded hard particles, which is applied to the component before irradiation and then bonded to it. Compared to conventional methods, which require a high vacuum and inductive heating of the component to join the preformed hard material carrier film, this method can, for example, save process time and reduce overall labor.

[0021] In an alternative preferred embodiment, the coating material is applied to the component as a powder jet via a nozzle within the working area. The use of a nozzle allows the powdered starting material to be supplied directly within the working area in the form of a powder jet, thereby avoiding overspray and reducing the overall consumption of powdered coating material compared to conventional methods. The coaxial application of the powder jet is also considered an invention independent of the monosilane-doped protective gas atmosphere and is hereby disclosed accordingly, although combinations with the other features disclosed herein are possible. Lateral feeding with a leading, co-leading, or trailing motion system also leads to advantageous repair results.

[0022] In a preferred embodiment, when applying the powdered coating material, the main flow direction of the powder jet generated by the nozzle is coaxial to the working jet, at least within the working area. In simplified terms, the powder jet is guided parallel to the working jet within the working area. Preferably, the powder jet surrounds the working jet in a ring-like fashion, at least within the working area (viewed in a plane perpendicular to the working jet), thus enclosing it at least partially, and preferably completely.

[0023] The coaxial arrangement of the powder jet and working jet enables, on the one hand, the targeted introduction of the powder jet containing the hard particles into the working area and, on the other hand, the avoidance of unwanted overspray. Furthermore, the coaxial arrangement of the powder and working jets allows for targeted material build-up, which is essentially independent of the direction of irradiation by the powder and working jets. Overall, this results in an improved material build-up rate compared to conventional systems. In addition, the hard particles can be precisely introduced into the working area, thereby locally increasing the strength of the component.

[0024] In a preferred embodiment, the protective gas atmosphere further comprises at least 95% argon and / or helium by mass. This protective gas atmosphere with a mass fraction of at least 95% argon and / or helium makes it possible, for example, to further reduce the hot cracking tendency of the processed alloys; thus, high-quality components can be obtained.

[0025] The invention also relates to a device for the section-by-section assembly or repair of a component, in particular a turbomachine component. This device comprises, in addition to a protective gas chamber with a receptacle for the component, an application device for depositing a metallic coating material onto the component in the working area and a power source. The device is configured, at least in one working area, to supply the component with a doped protective gas atmosphere containing at least 0.5% monosilane by mass.

[0026] The energy source is configured to generate a working jet in order to impart this jet to the metallic coating material in the working area in such a way that the matrix material is liquefied and consequently bonded to the component, whereby the aggregation state of the hard particles of the coating material remains unchanged during the welding process. The device is specifically designed to carry out the aforementioned process.

[0027] In a preferred embodiment, the working beam exhibits electromagnetic radiation with a spectral component at wavelengths of 380 nm to 490 nm and / or 490 nm to 580 nm, preferably with no spectral components outside these wavelengths. The electromagnetic radiation of the aforementioned wavelengths prevents coupling into the hard material particles (see above). In a preferred embodiment, the protective gas atmosphere further comprises at least 95% argon and / or helium by mass. The use of the described protective gas atmosphere reduces the tendency for hot cracking (see above).

[0028] In a preferred embodiment, the device further comprises a nozzle configured to apply the coating material to the component in the form of a powder jet within the working area. The use of a nozzle makes it possible to avoid unwanted overspray (see above).

[0029] In a preferred embodiment, the main flow direction of the powder jet generated by the nozzle is coaxial with the working jet, at least within the working area. This coaxial arrangement of the powder jet and the working jet enables, on the one hand, the targeted introduction of the powder jet containing the hard particles into the working area and, on the other hand, the prevention of unwanted overspray (see above).

[0030] In a preferred embodiment, the component is a rotationally symmetrical blade grid with a receiving bore arranged at a point of symmetry, wherein the receiving bore has a cylindrical shaft journal for receiving the blade grid. The cylindrical shaft journal is preferably designed to receive the rotationally symmetrical blade grid, namely having an outer diameter adapted to an inner diameter of the receiving bore. This makes it possible to position the component at its point of symmetry in the device. Furthermore, the component can be rotated about its axis of symmetry without reopening the device, for example, with a corresponding internal drive mechanism.

[0031] In a preferred embodiment, the protective gas chamber forms a cylindrical interior whose radius lies in a plane perpendicular to the central axis of the cylindrical shaft journal, and whose vertical axis is parallel to the central axis of the cylindrical shaft journal. The cylindrical interior reduces the volume of the interior exposed to the protective gas atmosphere compared to other housing shapes, thus requiring less protective gas overall. This can, for example, accelerate the flooding process of the interior and reduce protective gas consumption.

[0032] In a preferred embodiment, the device further comprises a gas-tight door with a central recess, wherein the shaft journal of the protective gas chamber is at least partially pressure-tightly enclosed in this recess when the door is closed. In simplified terms, the gas-tight door thus has a recess corresponding to the shaft journal. When the door is closed, the journal seals the recess pressure-tight, allowing the protective gas atmosphere to build up inside. The recess still allows access to the journal from the outside, and (provided the journal is rotatably mounted in the device) the component attached to it can be rotated from the outside about its axis of symmetry. This eliminates the need for an additional internal drive mechanism for rotating the component.

[0033] In a preferred embodiment, the device comprises a gas-tight movable aperture by means of which a lance and / or nozzle surrounding the working jet are introduced from an external environment into an interior formed by the protective gas chamber. The gas-tight movable aperture thus allows the working jet, which travels in the lance, and preferably also the powder jet, which travels in the nozzle, to enter the interior. Particularly preferably, the lance surrounds both the working jet and the powder jet, for example, in the case of a coaxial arrangement of the working jet and the powder jet.

[0034] Brief description of the drawings

[0035] The invention will now be explained in more detail using an exemplary embodiment, whereby the individual features within the scope of the dependent claims may also be essential to the invention in other combinations, and no distinction will be made in detail between the different claim categories.

[0036] Figure 1 shows a schematic representation of a mantle flow drive system to illustrate an advantageous application environment;

[0037] Figure 2a shows a schematic representation of a device for carrying out the method according to the invention;

[0038] Figure 2b shows an enlarged view of a coaxial superposition of a working jet and a powder jet;

[0039] Figure 3a shows a schematic top view of the device for the sectional assembly or repair of a component;

[0040] Figure 3b shows a section through the device along line AA (see Figure 3a).

[0041] Preferred embodiment of the invention

[0042] Figure 1 shows a turbomachine 100, specifically a turbofan engine, in axial section. The turbomachine 100 is constructed from a multitude of turbomachine components and is functionally divided into compressor 2, combustion chamber 3, and turbine 4. Both compressor 2 and turbine 4 are each composed of several stages, namely a low-pressure compressor 2.1, a high-pressure compressor 2.2, a high-pressure turbine 4.1, and a low-pressure turbine 4.2. Each of the stages 2.1, 2.2, 4.1, and 4.4 consists of a plurality of guide vanes and a rotor blade array or ring, each of which has a plurality of guide vanes and rotor blades, respectively. In compressor 2, the intake air is compressed; it is then combusted with added kerosene in the downstream combustion chamber 3 and fed to turbine 4.

[0043] Figure 2a shows a schematic representation of a device 17 for the section-by-section assembly or repair of the component 1, in particular the turbomachine component 2, 3, 4. This device 17 has, in addition to a protective gas chamber 12 with a receptacle 13 for the component 1, an application device 7 for applying a metallic coating material 8 to the component 1 in the working area A and a power source 9.

[0044] The device 17 is configured, at least in a working area A, to supply the component 1 with a doped protective gas atmosphere 6, which has a mass fraction of at least 0.5% monosilane. The energy source 9 is configured to generate a working jet 10 in order to apply the working jet 10 to the metallic coating material 8 in working area A in such a way that a matrix material 8.3 is liquefied and consequently bonded to the component 1 by means of a metallurgical bond, i.e., welded onto it, whereby the state of matter of the hard particles 8.4 of the coating material 8 embedded in the matrix material 8.3 remains unchanged during the welding process. The controlled supply of hard particles immediately before application to the component can also achieve advantageous repair results.This means that the mixing of metallic and ceramic coating materials does not necessarily have to take place in the powder feed unit of the system; rather, a defined and controlled introduction can be advantageous. The ceramic particles remain embedded, but this embedding only occurs shortly before the metallurgical bond is formed.

[0045] In the example shown in Figure 2a, the application device 7 is a nozzle 11 configured to apply the coating material 8 in the form of a powder jet 8.2 to the component 1 in the working area A. For clarity, the working jet 10 and the powder jet 8.2 are shown tilted relative to each other in Figure 2a; however, they are preferably arranged coaxially.

[0046] Figure 2b shows the working jet 10 and the powder jet 8.2 from Figure 2a in a coaxial arrangement, which is preferred. The coaxial arrangement makes it possible to introduce the hard material particles 8.4 in a controlled and direct coaxial manner into the powder jet 8.2 in the working area A.

[0047] Figure 3a shows a schematic top view of the device 17 for the section-by-section assembly or repair of a component 1. In the example shown, the protective gas chamber 12, viewed in a plane perpendicular to a central axis of the cylindrical shaft journal 14, forms a cylindrical interior space 12.1. This cylindrical interior space 12.1 is closed with a door 15; see Figure 3b.

[0048] Figure 3b shows a section through the device 17 along line AA. The section reveals the door 15, which has a central recess 15.1. In the closed state of the door 15 shown, the shaft 14 of the protective gas chamber 12 is at least partially pressure-tightly enclosed in this recess 15.1; thus, the interior space 12.1 is sealed gas-tight via this recess. Figure 3b also shows a gas-tight movable aperture 16, by means of which a lance 10.1 surrounding the working jet 10 and, optionally, the nozzle 11 are introduced from an external environment into an interior space formed by the protective gas chamber 12.

[0049] REFERENCE MARK LIST

[0050] Component 1

[0051] Compressor 2

[0052] Low-pressure compressor 2.1

[0053] High-pressure compressor 2.2

[0054] Turbine 3

[0055] Combustion chamber 4

[0056] High-pressure turbine 4.1

[0057] Low-pressure turbine 4.2

[0058] Protective gas atmosphere 6

[0059] Application device 7

[0060] Order material 8

[0061] Preform - Hard substrate film 8.1

[0062] Pul verstrahl 8.2

[0063] Matrix material 8.3

[0064] Hard particles 8.4

[0065] Energy source 9

[0066] Working beam 10

[0067] Lance 10.1

[0068] Nozzle 11

[0069] Inert gas chamber 12

[0070] Recording 13

[0071] Wave pin 14 gas-tight door 15

[0072] Recess 15.1, movable aperture 16

[0073] Device 17

[0074] Work area A

Claims

REQUIREMENTS 1. Method for the section-by-section assembly or repair of a component (1), in particular a turbomachinery component, in which: i) the component (1) is exposed to a protective gas atmosphere (6) at least in a working area (A), wherein the protective gas atmosphere (6) is doped with a mass fraction of at least 0.5% monosilane; ii) a metallic coating material (8) is applied to the component (1) in the working area (A), wherein the metallic coating material (8) is a matrix material (8.3) with embedded ceramic hard particles (8.4); and iii) the metallic coating material (8) in the working area (A) is subjected to a working jet (10) generated by an energy source (9) in such a way that the matrix material (8.3) is liquefied and consequently bonded to the component (1) in a metallurgical manner, whereby the state of matter of the hard particles (8.4) of the coating material (8) remains unchanged during the welding process.

2. Method according to claim 1, wherein the working beam (10) has electromagnetic radiation with a spectral component at wavelengths of 380 nm to 490 nm and / or 490 nm to 580 nm, preferably with no spectral components outside these wavelengths.

3. Method according to claim 1 or 2, wherein the coating material (8) is applied to the component (1) as a preform hard carrier film (8.1) in the working area (A).

4. Method according to claim 1 or 2, wherein the coating material (8) is applied to the component (1) as a powder jet (8.2) by means of a nozzle (11) in the working area (A).

5. Method according to claim 4, wherein, during the application of the powdered coating material (8), a main flow direction of the powder jet (8.2) generated by the nozzle (11) is coaxial to the working jet (10) at least in the working area (A).

6. Method according to any one of claims 1 to 5, wherein the protective gas atmosphere (6) further comprises at least a mass fraction of 95% argon and / or helium.

7. Device (17) for the section-by-section assembly or repair of a component (1), in particular a turbomachine component, comprising: a protective gas chamber (12) with a receptacle (13) for the component (1), wherein the device (17) is configured at least in a working area (A) for supplying the component (1) with a protective gas atmosphere (6) doped with a mass fraction of at least 0.5% monosilane; an application device (7) for applying a metallic coating material (8) to the component (1) in the working area (A), wherein the metallic coating material (8) is a matrix material (8.3) with embedded ceramic hard particles (8.4); and an energy source (9) configured to generate a working jet (10) in order to supply the metallic coating material (8) in the working area (A) with the working jet (10) such that the matrix material (8.3) is liquefied and consequently bonded to the component (1), whereby the state of matter of the hard particles (8.4) of the coating material (8) remains unchanged during welding.

8. Device (17) according to claim 7, wherein the working beam (10) has electromagnetic radiation with a spectral component at wavelengths of 380 nm to 490 nm and / or 490 nm to 580 nm, preferably with no spectral components outside these wavelengths.

9. Device (17) according to claim 7 or 8, wherein the protective gas atmosphere (6) contains at least 95% argon and / or helium by mass.

10. Device (17) according to one of claims 7 to 9, further comprising a nozzle (11) which is configured to apply the coating material (8) in the form of a powder jet (8.2) to the component (1) in the working area (A).

11. Device (17) according to claim 10, wherein a main flow direction of the powder jet (8.2) generated by the nozzle (11) is coaxial to the working jet (10) at least in the working area (A).

12. Device (17) according to one of claims 7 to 11, wherein the component (1) is a rotationally symmetrical blade grid with a receiving bore arranged at a point of symmetry, and wherein the receiving (13) has a cylindrical shaft journal (14) for receiving the blade grid.

13. Device (17) according to claim 12, wherein the protective gas chamber (12) forms a cylindrical interior space (12.1).

14. Device (17) according to claim 12 or 13, further comprising a gas-tight door (15) which has a recess (15.1) in the center, wherein the shaft journal (14) of the protective gas chamber (12) is received in this recess (15.1) at least partially in a pressure-tight manner when the door (15) is closed.

15. Device (17) according to one of claims 7 to 14, further comprising a gas-tight movable aperture (16) by means of which a lance (10.1) surrounding the working jet (10) and / or the nozzle (11) are introduced from an external environment into an interior formed by the protective gas chamber (12).

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