Apparatus for removing excess material and method of operating the same

Abstract

A device (100) for removing excess material (P), preferably powder, from a cavity (12) of a component (10) is provided. The device comprises: a platform (1) for holding a component (10), preferably an additively manufactured component (10), a drive mechanism (2) coupled to the platform (1), wherein the drive mechanism (2) is configured to independently rotate the component (10) held by the platform (1) around two orthogonal spatial directions (X, Y), each with an unlimited angular deflection (α, β), an actuation device (3) for mechanically actuating the platform (1) during removal of the excess material (P), and a housing (4) defining a workspace (WS) in which the excess material (P) can be removed from the cavity (12), wherein the housing (4) seals the workspace (WS) with respect to the environment, and wherein any electrical components for the drive mechanism (2) are arranged outside the workspace (WS). Furthermore, a method for operating the device is provided.

Description

[0001] The invention discloses an apparatus for additive component manufacturing, in particular for removing excess material, preferably powder, from a cavity of a component. Furthermore, a method for operating the apparatus is proposed. The apparatus may be a packing device, which is particularly suitable for application in a powder bed fusion process for the manufacture of metal components.

[0002] Preferably, the component refers to a component which is applied in turbomachinery, for example in fluid path hardware of a gas turbine.Therefore, preferably, the component is made of a nickel-based or cobalt-based superalloy, for example a precipitation hardening alloy.

[0003] For example, a comparable device for additive manufacturing is described in, for example, WO 2017 / 215921 A1.

[0004] Additive manufacturing and / or powder bed fusion methods have proven to be useful and advantageous in the production of prototypes or complex components, such as components with maze-like or convoluted structures or functional cooling components. In addition, additive manufacturing stands out due to its short chain of process steps, which in turn enables material savings and particularly short delivery times.

[0005] The term "additive" in the context of manufacturing shall particularly refer to a layer-by-layer, generative, and / or bottom-up manufacturing process.

[0006] For example, powder bed-based or powder bed fusion (PBF) manufacturing methods, such as selective laser melting (SLM), selective laser sintering (SLS), or electron beam melting (EBM) are relatively well-known methods for making, prototyping, or manufacturing parts or components from powdered substrates. Conventional equipment or settings for such methods typically include a manufacturing or construction platform on which components are constructed layer by layer after feeding a layer of a substrate, which can then be melted and subsequently solidified, for example, by the energy of a laser beam. The layer thickness is determined by a recoater or wiper, which, for example, automatically moves over the powder bed and removes excess material from the manufacturing plane or construction space. Typical layer thicknesses total between 20 μm and 40 μm. During manufacturing, the laser beam scans over the surface and melts the powder on a selected area, which can be predetermined by a CAD file according to the geometry of the component to be manufactured.

[0007] After the additive buildup of a part or component by powder bed fusion, i.e. preferably after the individual construction works, "3D printing", are completed, the internal channels and cavities of the constructed part (or parts) are inherently filled with residual powder or excess material. Therefore, it is necessary to remove the excess material from the internal cavities of the manufactured component. However, because the parts or components are usually heavy due to the powder filling, it is not easy to remove the excess powder. In particular, gas turbine components are heavy due to the need to use high-performance alloys. In addition, the internal channels and cavities may be narrow, convoluted, or form particularly complex shapes.

[0008] In summary, inadequate removal of powder from cavities or internal passages or channels of manufactured parts can lead to serious problems during post-manufacturing heat treatments, where the parts often need to be exposed in order to relieve mechanical stresses or similar purposes. During said heat treatments, the remaining powder in the cavities may melt, sinter, or bond together and subsequently block the channels. Obviously, these effects may result in a small loss of the entire part.

[0009] In view of the increasing importance of additive manufacturing in industry, as well as the increasing relevance of digitalization and the so-called "Internet of Things", there is a need for reliable process chains and technologies suitable for stimulating or supporting the industrialization of additive manufacturing. In particular, there is a need for robust and / or heavy-duty equipment that enables the reliable and safe removal of said excess base material from the interior of a component constructed with a powder bed.

[0010] Even though there are commercially available instruments that help facilitate the "de-powdering" or unpacking of additively produced parts, parts are often cleaned of any excess powder manually or using simple mechanical tools. Manual methods are particularly time-consuming and expensive in terms of time and money.

[0011] Even the most advanced suppliers of given "de-powdering" equipment suffer from a lack of operational safety. Any motors and / or electrical drives for shaking out powder residues and / or for moving or tilting fixed platforms of the individual components (see, for example, DE 10 2013 223407 A1) provide a possible source of ignition in the workspace or construction space. This, in turn, poses a serious danger to any operator of the respective manufacturing device. It is known that, for example, in the presence of oxygen or traces of oxygen in the construction space or de-powdering equipment, small micrometer-sized powder particles are extremely flammable and / or explosive.

[0012] The object of the present invention is to provide means to overcome the described disadvantages. In particular, a device for removing said excess powder material is provided, which complies with industrial requirements or demands in terms of operational safety. Furthermore, the device is particularly versatile and robust and is also suitable for being applied in (industrial) additive manufacturing sequences of heavy parts.

[0013] The stated objects are achieved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0014] The object of the present invention relates to a device for removing excess material, preferably powder, from a cavity of a component. The device comprises a platform for carrying, retaining and / or fixing a component, preferably an additively manufactured component.

[0015] The apparatus further comprises a drive mechanism coupled to the platform, wherein the drive mechanism is configured to independently rotate or deflect the component, assuming the component is held by the platform, about two orthogonal, preferably linearly independent spatial directions, each with unlimited angular deflection. Such endless or infinite rotational freedom of the platform is particularly important for sophisticated strategies that may have to be controlled in order to clear heavy and very complex components of powdered substrates.

[0016] The apparatus also includes an actuating device for mechanically actuating the platform during the removal of excess material. Preferably, the actuating device is configured to actuate the substrate at a wide frequency range or multiple frequencies or frequency ranges. By the actuating device, for example, the platform is typically shaken or moved, and simultaneously rotated, tilted, or its orientation is changed, so as to conveniently remove any residual powder material from the cavity of the part having a delicate internal passage structure.

[0017] The device also includes a housing defining a working space in which excess material can be removed from the cavity, wherein the housing preferably seals the working space against the environment. The working space can be a space of an apparatus and / or an additive manufacturing device, which is typically contaminated or tainted by metal powders at least during its operation. Therefore, in the presence of oxygen or traces of oxygen in the working space, due to the highly reactive micron-sized powder particles as mentioned above, there are inevitably significant health risks and / or deficiencies in operational safety. The working space can also be a spatial volume that can theoretically be fluidly connected to any area of ​​the additive manufacturing device or the corresponding unpacking station or equipment that is contaminated or tainted by powder.

[0018] According to the proposed device, electrical components, circuits, connections etc. for the drive mechanism are arranged outside the working space.

[0019] Thus, any risk of ignition of powder clouds or dust explosions during the removal of the substrate in the device can be reduced to a minimum or even completely excluded. Thus, the operational safety of the additive manufacturing plant of the facility can be increased or even ensured. In view of the current industrialization trends, the proposed device can even provide the prerequisites for the widespread application and / or automated integration and industrialization of additive manufacturing.

[0020] In an embodiment, the drive mechanism comprises two independently controllable worm gears or worm gear boxes, each of which is configured to rotate the platform around a spatial direction. According to this embodiment, infinite rotational freedom or movement with unlimited angular deflection can be easily achieved.

[0021] In an embodiment, the electric motor for driving the mentioned worm gear and any electrical connections are arranged outside the working space or are fluidically sealed or separated with respect to the working space.Therefore, metal dust explosions can be reliably prevented.

[0022] In an embodiment, the actuation device is arranged inside the workspace and is driven by pressurized inert gas without any electrical gear. According to this embodiment, actuation of the platform can be achieved without any electrical drive, which may be a source of ignition or reaction of the remaining metal powder. At the same time, the actuation device can be arranged very close to the platform and has a large amount of momentum for actuating, shaking, or vibrating components loaded with even heavy powders.

[0023] In an embodiment, the actuation device comprises a first vibration generator configured for actuating the substrate and / or the component at a first frequency of the frequency range.

[0024] In an embodiment, the actuation device comprises a second vibration generator configured for actuating the substrate and / or the component at a second frequency.

[0025] Preferably, the second frequency or frequency range is different from or separate from the first frequency of the frequency range.

[0026] According to these embodiments, actuation can be performed for different purposes. For example, in order to reliably remove powder in the context of additive manufacturing, it is often necessary to loosen or break up powder particles that are, for example, partially melted or sintered in a cavity or inner space. In a separate step, the loosened powder must then still be shaken out of any cavity, such as, for example, by moving according to a trajectory that defines an optimal escape channel out of the component.

[0027] In an embodiment, the first vibration generator is a low frequency, high impact or momentum generator. According to this embodiment, the actuator device can be configured for actuation of particularly heavy structures or components, for which a higher momentum and / or power is required. Thus, for example, the actuator device can be customized for actuation of larger amplitudes. For example, when the additively manufactured part or component is heavy, customization may be required if the internal space or cavity is very large and / or a large amount of powder must be shaken out of the cavity.

[0028] In an embodiment, the second vibration generator is a high frequency, low impact or momentum generator. According to this embodiment, the actuator device can be configured for actuation of, for example, lighter components, for which the actuation of the lighter components is dominant, the frequency is critical, and only a small momentum or power is required. Therefore, the actuator device can be customized only for high frequency and small amplitude actuation. For example, when the additively manufactured component is quite small and the internal space from which the powder must be removed is also small and may be complex or maze-like, customization may be required. In addition or alternatively, the second vibration generator can actually also be used to loosen the powder in the case of heavy components.

[0029] In an embodiment, wherein the first frequency of the frequency range comprises a frequency from 1 mHz to 1 Hz or from 100 mHz to 1 Hz.

[0030] In an embodiment, the second frequency of the frequency range includes frequencies from 1 Hz to 10 kHz.

[0031] In an embodiment, wherein the first vibration generator and the second vibration generator are independently controllable.

[0032] In an embodiment, the device is configured to allow driving and actuating and / or rotating the platform (for removing powder) while carrying or holding a large mass, in particular a mass greater than 50 kg. According to this embodiment, preferably, the weight of the component together with the residual shaft material included or surrounded is greater than 50 kg.

[0033] In an embodiment, the apparatus is configured such that a powdered substrate contained in a cavity, for example a complex or convoluted cavity, of a component may be removed or shaken out of said cavity by mechanical actuation of the platform.

[0034] In an embodiment, the device comprises a control unit connected to the drive mechanism and / or the actuating means. By means of the control unit, the entire device may preferably be controlled, for example, by computer control and / or an algorithm, which may cause the device to operate such that an optimized or ideal escape path or powder travel route is selected. The path or route may, for example, be the result of a calculation and / or simulation.

[0035] Another aspect of the invention relates to a method of operating an apparatus wherein the apparatus is controlled by a computer program that drives and actuates the platform taking into account gravity, the location of the cavity opening of the component, and the desired removal path of the shaft material.

[0036] Advantages and embodiments described in relation to the device may also relate to the method of operating the device, and vice versa.

[0037] Other features, conveniences and advantageous modifications will become apparent from the following description of exemplary embodiments taken in conjunction with the accompanying drawings.

[0038] Figure 1 In the schematic diagram an additive powder bed fusion process is shown in which a component is shown during its additive manufacturing process.

[0039] Figure 2 A simplified schematic diagram of an apparatus according to the invention for removing excess material from the interior of an additively manufactured component is shown.

[0040] Similar elements, elements of the same type and elements having the same function may be provided with the same reference symbols in the figures.

[0041] Figure 1 An additive manufacturing device 200 is shown. The device 200 may constitute state-of-the-art hardware for selective laser melting or electron beam melting. The device 200 comprises a constructed platform or substrate 11. On the substrate 11, preferably, a component 10 is directly manufactured, i.e. welded. Preferably, the component 10 is layered in the device 200 with a powder bed of powder P. Preferably, the component or part 10 relates to a turbine component, such as a component applied in the hot gas path of a gas turbine (not explicitly indicated). In particular, the component 10 may relate to a blade, a vane, a shroud, a barrier, such as a thermal barrier, a tip, a segment, an insert, an injector, a seal, a transition, a burner, a nozzle, a filter, an orifice, a bushing, a distributor, a dome, a booster, a cone, a lance, a plate, a resonator, a piston, or any corresponding modification.

[0042] exist Figure 1 In the embodiment, the component 10 is preferably drawn during its manufacture and only partially built up. This means that after the powder layers have been deposited, for example with the help of a deposition device or a re-coater 30, the energy beam 21 is used to selectively melt the powder for the layer-by-layer build-up of the component 10. Figure 1 As indicated on the right side of , the layer thickness of this layer can amount to LT.

[0043] Preferably, said energy beam 21 is emitted from an irradiation device 20, such as an electron beam or a laser source. After local melting due to the energy beam 21, the material is conveniently solidified in the final structure of the component 10.

[0044] After the layer has been manufactured, the platform 1 is preferably lowered by a distance corresponding to the layer thickness LT. Figure 1 As shown on the left, the deposition device 30 preferably dispenses a further powder layer, which can be moved from a corresponding supply or supply of powdery substrate P (not explicitly indicated by numbers).

[0045] Preferably, the actual powder bed fusion process is performed in an inert gas atmosphere or at least in an atmosphere with a reduced oxygen content, in order to avoid significant oxidation or degradation of the powder and / or the component 10. The inert gas or gas flow (not explicitly indicated) can be established in a laminar manner as follows, for example, with an inlet and an outlet in the constructed space. Additionally or alternatively, during operation of the device, the inert gas can be used to purge or "inertize" only parts of the powder bed, such as the molten pool.

[0046] Figure 2 The apparatus 100 is shown in a schematic (at least partially) cross-sectional view. Preferably, the apparatus 100 is a depackaging apparatus and / or is configured for removing excess material P, preferably excess powder as a base material, from an interior, cavity, or other passage or space defined by the structure and / or design of the manufactured part 10.

[0047] The device 100 includes a device for holding a component (see Figure 2 The platform 1 of the figure mark 10 in FIG. The platform can be a table, and the base plate 11 can be fixed or clamped or otherwise fastened to the table.

[0048] The device 100 further comprises a drive mechanism 2 coupled to the platform 1. Preferably, the drive mechanism 2 is configured to independently rotate or deflect the component 10 around two orthogonal spatial directions, the two orthogonal spatial directions being defined by Figure 2 denoted by the horizontal axis X and the vertical axis Y in the figure. Preferably, the drive mechanism 2 enables the platform 1 to be deflected or rotated with unlimited degrees of freedom around the X-axis and the Y-axis. In other words, preferably, the platform can be rotated in an endless cycle or in a multi-rotation manner, so that very complex and delicate powder escape rotations and actuations of the platform carrying or holding the component can be applied in order to reliably remove excess powder P from the cavity (not explicitly indicated) of the component 10.

[0049] Figure 2 It is shown that a rather complex and heavy component 10 is arranged, preferably welded, to a base plate 11. The base plate 11 is, in turn, held by the platform 1. Figure 2 In the drawings, the numeral RP is also used to indicate a curved arrow. The arrow RP will indicate the powder removal path of a powder P which, for example, remains close to the substrate 11 and originates from a powder bed-based manufacturing (see Figure 1 ).

[0050] To facilitate rotation, for example about the X-axis, a first motor M1 is provided by the drive mechanism 2. Preferably, the motor M1 drives a drive shaft via a first worm gear or worm gearbox WG1, so that the platform 1 can be angularly deflected or rotated by an angle α.

[0051] To facilitate rotation, for example about the Y axis, a second motor M2 is provided by the drive mechanism 2. Preferably, the motor M2 drives the drive shaft via a second worm gear or worm gearbox WG2, so that the platform 1 can be angularly deflected or rotated by an angle β.

[0052] In particular, the worm gear embodiment allows for unlimited rotational movement when the motors M1 , M2 , respectively, are operated continuously.

[0053] The worm gears WG1 , WG2 expediently act independently, wherein each worm gear is provided for rotating the platform 1 about a respective spatial direction.

[0054] like Figure 2 As shown in , preferably, the motor, drive shaft and worm gear (box) are arranged so that the independent control and movement can be achieved. To this effect, the second worm gear WG2 or its corresponding drive shaft (not explicitly shown) is, for example, axially positioned (i.e., aligned with the X-axis), wherein the first worm gear (box) WG1 can be aligned with the Y-axis and / or parallel to the longitudinal axis of the component 10 orthogonal to the base plate 11.

[0055] exist Figure 2 In the exemplary embodiment given in , the platform 1 may be directly mounted with a platform plane which is vertically aligned with respect to the drive shaft of the second worm gear WG2. Furthermore, the platform 1 is coupled and / or fixed to the rod of the first worm gear WG1.

[0056] Of course, the motors M1, M2 can be controlled independently, so that any superposition of the rotational movements can be selected and implemented for very complex powder removal paths (see above). For example, by these infinite rotational degrees of freedom about two linearly independent spatial directions (X, Y), every appreciable orientation of the component 10 can be achieved. For simplification purposes only, Figure 2 Only the vertical alignment orientation of the longitudinal axis of the component 10 is shown (see the X axis). Therefore, assuming that customized or intelligent control and algorithms are applied to the control of the device, drive mechanism and / or actuator, it is possible to obtain the vertical alignment orientation of the longitudinal axis of the component 10 from the cavity (in Figure 2The only reason for this is that there is an opening of sufficient size in the chamber through which the substrate can escape from the part.

[0057] If the component 10 is, for example, a combustor component for a gas turbine, the calculated or simulated escape routes through which the powder P must be removed may be very complex and require the use of many customized movements and actuations to control the device.

[0058] Preferably, the device 100 further comprises a control unit 40. Via the control unit 40, the device 100 may be controlled, for example computer controlled. Thus, the control unit 40 may constitute or comprise a data processing unit.

[0059] The apparatus 100 further comprises a housing 4. Preferably, the housing 4 defines a work space WS. During operation of the apparatus 100, the work space WS is conveniently contaminated, stained, or exposed to or fluidly connected to residual powder material P that is actually being removed from the interior of the component 10. Thus, the swirling dust or powder cloud may cause a significant risk of fire or explosion.

[0060] according to Figure 2 In the embodiment shown in FIG. 5 , during or after the removal of powder in the working space WS, residual powder P may fall to the bottom of the working space WS and be collected in a hopper and / or a collecting tray 5 .

[0061] According to the present solution, the housing 4 seals a working space WS (not explicitly indicated) from the environment by means of a seal 6. The seal 6 can, for example, surround a drive shaft of an electric motor M1, M2 for driving the respective worm gear.

[0062] Figure 2 It is also shown that any electrical components for the drive mechanism and / or any further sensible electrical components are arranged outside the working space WS in order to reduce and most preferably exclude any risk of the powder cloud catching fire in the working space WS.

[0063] The device 100 also comprises actuation means 3 for mechanically actuating the platform during the removal of excess material P.

[0064] The actuating device 3 is arranged inside the working space WS and is driven by pressurized inert gas without any electrical tools. This allows minimizing the risk of dust fire and / or explosion in the working space WS (see above).

[0065] The actuation device 3 comprises a first vibration generator Vbr1 configured to actuate the platform 1 , the substrate 11 and / or the base material P at a first frequency F1 corresponding to the frequency range.

[0066] Preferably, the actuating device 3 further comprises a second vibration generator Vbr2, which is configured to actuate the platform 1, the substrate 11 and / or the base material P at a second frequency F2 or a corresponding frequency range.

[0067] Preferably, the second frequency (range) F2 is different from the first frequency (range) F1.

[0068] Preferably, the first vibration generator Vbr1 is a low frequency, high impact generator.The first frequency F1 may, for example, include or span frequencies from 1 mHz to 1 Hz.

[0069] On the other hand, preferably, the second vibration generator Vbr2 is a high frequency, low impact generator. The second frequency F2 may include frequencies from 1 Hz to 10 kHz.

[0070] Although the actuating device 3 is preferably arranged inside the working space WS, this embodiment of the actuating device 3 does not offer a risk of explosion, since the actuating device 3 is preferably driven by pressurized inert gas and without any electrical tools. Furthermore, the actuation can be performed in situ, i.e. directly at the platform 1 and in the vicinity of the platform 1, where the actuation effect is required.

[0071] Preferably, the device 100 and all its components and features are configured to drive, i.e., move, actuate, and rotate a large mass, preferably a mass exceeding 10 kg, preferably a mass exceeding 50 kg, or even a larger mass, such as a mass exceeding 100 kg or more. Thus, the device 100 can be applied in a very versatile manner, without limiting the substrate used.

[0072] The scope of protection of the present invention is not limited to the examples given above. Even if this feature or this combination of features is not explicitly stated in the claims or examples, the present invention can be implemented with each novel characteristic and each combination of characteristics, and each combination of the above characteristics particularly includes each combination of any features stated in the claims.

Claims

1. An apparatus (100) for removing excess material (P) from a cavity (12) of a component (10), comprising: - a platform (1) for holding said component (10), - a drive mechanism (2) coupled to the platform (1), wherein the drive mechanism (2) is configured to independently rotate the component (10) held by the platform (1) around two orthogonal spatial directions (X, Y), and the platform (1) has unlimited angular deflection (α, β) around each orthogonal spatial direction, - actuation means (3) for mechanically actuating said platform (1) during the removal of said excess material (P), and - a housing (4) defining a working space (WS) in which the excess material (P) can be removed from the cavity (12), wherein the housing (4) seals the working space (WS) relative to the environment, wherein any electrical components for the drive mechanism (2) are arranged outside the working space (WS), and wherein the drive mechanism is configured to rotate the platform around the two orthogonal spatial directions (X, Y) when the platform is inside the housing.

2. The device (100) according to claim 1, in, The excess material includes powder.

3. The device (100) according to claim 1, in, The component comprises an additively manufactured component.

4. The device (100) according to any one of claims 1 to 3, wherein: The drive mechanism (2) comprises two independently controllable worm gears (WG1, WG2), each of which is configured for rotation of the platform (1) around a spatial direction (X, Y), and wherein a first motor and a second motor for driving the worm gears (WG1, WG2) and any electrical connections are arranged outside the work space (WS).

5. The device (100) according to any one of claims 1 to 3, wherein: The actuating device (3) is arranged inside the working space (WS) and is driven by pressurized inert gas and without any electrical tools.

6. The device (100) according to any one of claims 1 to 3, wherein: The actuating device (3) comprises a first vibration generator (Vbr1) and a second vibration generator (Vbr2), wherein the first vibration generator is configured to actuate the platform (1) at a first frequency (F1), and the second vibration generator is configured to actuate the platform (1) at a second frequency (F2) different from the first frequency (F1).

7. The device (100) according to claim 6, wherein The first vibration generator (Vbr1) is a low frequency high impact generator, and the second vibration generator (Vbr2) is a high frequency low impact generator.

8. The device (100) according to claim 6, wherein The first frequency (F1) includes frequencies from 1 mHz to 1 Hz.

9. The device (100) according to claim 6, wherein: The second frequency (F2) includes frequencies from 1 Hz to 10 kHz.

10. The device (100) according to claim 6, wherein: The first vibration generator (Vbr1) and the second vibration generator (Vbr2) are independently controllable.

11. The device (100) according to any one of claims 1 to 3, wherein: The device (100) is configured to allow driving and actuating the platform (1) while maintaining a large mass greater than 50 kg.

12. The device (100) according to any one of claims 1 to 3, comprising: A control unit (40) is connected to the drive mechanism (2) and the actuating device (3).

13. A method of operating a device (100) according to any one of claims 1 to 12, wherein: The device (100) is controlled by a computer program that drives and actuates the platform (1) taking into account gravity, the cavity opening of the component (10) and the desired excess material removal path (RP).

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