METHOD FOR PROVIDING DATA FOR ADAPTIVE TEMPERATURE REGULATION

Abstract

A method, device, and computer program product for providing data for temperature regulation in the additive manufacture of a component, where the method includes a) acquiring temperature data at various positions of a layer built up additively; b) processing the layer for the component using a processing device at the positions of the layer, wherein regulation data for regulating the processing device is acquired depending on a position; and c) generating an adapted data set from the acquired data comprising position-dependent adapted regulation data.

Claims

1. A method for providing data for temperature regulation in the additive manufacturing of a component, comprising: a) capturing temperature data in each case at different positions of an additively constructed layer, b) processing the layer for the component with a processing device at the positions of the layer, wherein regulation data for regulating the processing device are captured in a position-dependent manner, wherein the regulation data denote data or parameters of or for a PID regulator, wherein the regulation data include or regulate a control parameter which is suitable for controlling, for the processing, a heating power for preheating a layer during the construction of the component, and c) generating an adapted data record from the captured data comprising position-dependent adapted regulation data.

2. The method as claimed in claim 1, wherein a further layer following the layer during the manufacturing of the component is processed according to the adapted regulation data.

3. The method as claimed in claim 1, wherein the adapted data record comprises only the adapted regulation data.

4. The method as claimed in claim 1, wherein the adapted data record comprises temperature data in addition to the adapted regulation data.

5. The method as claimed in claim 1, wherein the regulation data to be captured for each position on the layer are captured and/or stored over a predetermined course of time.

6. The method as claimed in claim 1, wherein the adapted data record is generated by machine optimization methods.

7. The method as claimed in claim 1, which is a computer-implemented method.

8. The method as claimed in claim 1, which is a recursive method which is used again for successive layers during the manufacturing of the component.

9. An apparatus for controlling a processing device, comprising: means for carrying out the steps of the method as claimed in claim 1, a temperature capture device, a computer, and a regulation device.

10. The apparatus as claimed in claim 9, which is configured in such a manner that the temperature capture device, the computer, the regulation device and an inductive heating device coupled to the apparatus form a measurement system together with a structure of at least one constructed layer of the component.

11. The apparatus as claimed in claim 9, which is part of an additive manufacturing system.

12. A non-transitory computer readable media, comprising: instructions which, when executed by a computer, cause the computer to perform the method as claimed in claim 1.

13. A method for the additive manufacturing of a component, comprising: layer-by-layer additive construction of the component from a powder, wherein, after or during the solidification of a powder layer by means of an energy beam, this layer is processed by means of the processing device on the basis of the method as claimed in claim 1.

14. The apparatus as claimed in claim 9, wherein the apparatus comprises an inductive heating device.

15. The apparatus as claimed in claim 11, wherein the additive manufacturing system comprises a system for powder-bed-based additive manufacturing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIG. 1 shows a schematic sectional view of a component during its additive manufacturing.

[0055] FIG. 2 shows a schematic plan view of a component cross section which is processed with a processing device.

[0056] FIG. 3 uses a schematic plan view of a solidified component layer to indicate a sequence of a plurality of processing steps.

[0057] FIG. 4 shows a schematic flowchart which indicates method steps of the method described.

DETAILED DESCRIPTION OF INVENTION

[0058] In the exemplary embodiments and figures, identical or identically acting elements can each be provided with the same reference signs. The elements shown and their proportions to one another are fundamentally not to be regarded as true to scale; rather, individual elements can be shown exaggeratedly thick or with large dimensions for better presentability and/or for better understanding.

[0059] FIG. 1 uses a schematic sectional view to indicate the additive manufacturing of a component 10 from a powder bed, advantageously by means of selective laser melting or electron beam melting. A corresponding additive manufacturing system is identified with the reference sign 200.

[0060] A starting material P for the component 10 is selectively irradiated in layers by an energy beam, advantageously a laser beam 105, in accordance with the desired (predetermined) geometry. For this purpose, the component is manufactured on a substrate or a construction platform 12 or welded to it.

[0061] The platform simultaneously serves as a mechanical support during manufacturing in order to protect the component from thermal distortion. After the solidification of each layer, a manufacturing surface (not explicitly identified) is newly coated with powder P, advantageously by a coater 11, and the component is constructed further in this way. Layers 1 and 2 are indicated by dashed lines in FIG. 1 merely by way of example, the layer thickness of which in such processes is usually between 20 and 80 μm.

[0062] The component 10 is advantageously a component which is used in the hot gas path of a turbomachine, for example a gas turbine. In particular, the component can be a rotor or guide blade, a segment or ring segment, a burner part or a burner tip, a frame, a shield, a heat shield, a nozzle, a seal, a filter, an orifice or lance, a resonator, a stamp or an agitator, or a corresponding transition, insert, or a corresponding retrofit part. Accordingly, the component 10 is advantageously a component that is thermally and/or mechanically highly stressed in its intended operation and is made of a superalloy, for example a cobalt-based or nickel-based superalloy.

[0063] A processing device 20 is also indicated on the right-hand side of a manufacturing surface (on the right in the figure). The processing device can be used to expediently pretreat and/or post-treat a newly applied powder layer or a freshly solidified or irradiated component layer. This processing is particularly advantageous or expedient in order to carry out an advantageous or necessary heat treatment (heat management) of the corresponding components, advantageously in-situ during construction.

[0064] The large process-inherent temperature gradients in powder-bed-based processes often exceed 10.sup.5 K/s and accordingly cause high chemical imbalances, cracks and/or mechanical stresses. It is therefore expedient, for example, to thermally treat a newly applied powder layer (see reference sign 2) or an already solidified component layer (see reference sign 1) with a processing device (see reference sign 20).

[0065] The means described in the present case for the processing or the processing device 20 are advantageously suitable for heating a processing or preheating of the component or a component layer to be subsequently manufactured to a temperature of over 1000° C.

[0066] FIG. 2 shows a schematic plan view of a layer 1 freshly irradiated with the energy beam 105 and solidified. As in FIG. 1, a coater 11 or a coating device can be seen here, which is configured to apply new powder P for a layer to be subsequently irradiated (see reference sign 2 in FIG. 1).

[0067] According to the illustration in FIG. 2, the cross section of the component 10 is only shown in a rectangular shape for the sake of clarity. In the case of components for which additive manufacturing is offered or worthwhile, this is of course often not the case, and the component cross section can have a complicated geometry, for example a geometry which is not closed or has cavities.

[0068] In contrast to FIG. 1, according to the present invention, it is possible to see a processing device 20 which advantageously comprises or represents an inductive heating device. Alternatively, the processing device can introduce heat into a component layer using a different principle, for example.

[0069] A conventional additive manufacturing system (see reference sign 200 in FIG. 1) advantageously comprises a temperature capture device 101, advantageously an infrared camera, which can be used to record, advantageously for each irradiated layer, a complete temperature image of the layer or of the manufacturing surface. An item of image information from the temperature image can, for example, be converted into a temperature via calibration and can be evaluated at corresponding positions of later processing (see FIG. 3 further below).

[0070] Via a computer 102 or a data processing device and advantageously also a regulation device 103, captured temperature data, advantageously said temperature or the thermal image of the layer 1, can be stored and transferred to the processing device 20 or this can be controlled accordingly.

[0071] An apparatus 100 can accordingly be configured to control the processing device 20 and can also comprise said computer program means (see reference sign CPP further below), the temperature capture device 101, the computer 102 and, for example, the regulation device 103. Accordingly, the apparatus 100 can be coupled or connected to the processing device 20.

[0072] In the embodiment shown in FIG. 2, the processing device 20 has an inductive heating device or an induction coil 104. Although this is not explicitly shown, the device 20 can also have a plurality of induction coils, for example a coil arranged displaceably or movably along the X direction and a coil arranged displaceably or movably along the Y direction. The coils mentioned can also be superimposed in such a way that desired or predefined heating, for example heating of over 1000° C., can be achieved only in a selected region (cf. “region of interest” and reference sign ROI). For the sake of simplicity, only one coil 104, which can heat a region ROI to be selected in a predefined manner, is identified in FIG. 2. The coil 104 is arranged to be movable and displaceable along the X direction. In the same way, a similar coil could be movable along the Y direction and arranged in such a way that the selected region ROI can be expediently heated.

[0073] The processing device 20 is also advantageously configured, through its movability, over any positions above the powder bed or the layer surface that both an already solidified component layer (see layer 1) and a layer of newly applied powder material (see layer 2) can be heated. In contrast to the solid component structure, however, heating of the powder (see on the left in FIG. 2) is negligible, and the heating power is dominated or absorbed by the already solidified layers at the bottom. In the SLM method, these layers are generally significantly thinner than the penetration depth of the induction field or the magnetic flux of the coil(s) 104 that induces the eddy currents.

[0074] The apparatus 100 is advantageously also configured in such a manner that the temperature capture device 101, the computer 102, the regulation device 103 and an inductive heating device 20, 104 coupled to the apparatus 100 form a measurement system S or a corresponding regulation chain together with a structure of at least one constructed layer 1 of the component 10. This system or this regulation chain is composed of the temperature capture device 101, the computer 102 and the aforementioned computer program means, the device 20 or the induction coil 104 and the structure of the component 10 itself, or comprises these components.

[0075] For example, with each recorded camera or temperature image, the measurement system S transfers an actual temperature for each selected region ROI to the regulation device 103 which comprises a PID regulator, for example.

[0076] The component 1, 10 itself or the point currently to be heated or preheated can influence the regulation in two ways in this case: On the one hand, the coupling efficiency and thus the effect of the induction heating on the component 10 can change. On the other hand, the limited heat conduction can lead to a delay between heating and temperature change. Both variables or values are greatly dependent on the actual geometry and are usually unknown to the regulation system. Even if the geometry is exactly known, the values can only be determined by complete simulation of the electrical and thermal behavior that adequately describes the phenomena described.

[0077] The present invention now proposes means for optimizing and improving the regulation system in such a way that the simulations mentioned can be dispensed with, and for deriving adapted data or regulation parameters from the system itself (see FIGS. 3 and 4 further below).

[0078] FIG. 3 shows, on the basis of a representation similar to the representation in FIG. 2, a sequence of processing steps, on the basis of which a solidified component layer 1 is processed, advantageously inductively heated, advantageously immediately, after solidification by means of the processing device 20 described.

[0079] For example, a heat treatment tailored to the alloy of the component may be necessary or advantageous, for example, in order to relieve tension in the component, avoid or prevent hot cracks or to prevent large process-inherent temperature gradients which in turn prevent cracks, chemical imbalances or, in principle, weldability of the base material.

[0080] The corresponding processing regions (compare ROI at positions P1, P2 and P3 in FIG. 3) can be, for example, those positions which are also irradiated one after the other according to an irradiation strategy. Alternatively, they may be specially selected regions, for example regions in the layer which are particularly susceptible to structural defects or other factors, for example strength-related factors. The positions can also—unlike in FIG. 3—merge continuously or steadily into one another.

[0081] Typically, after processing a first position P1, the coil 104 or the processing device 20 is moved to a subsequent second position P2 or third position P3, which then indicates a not yet heated or cold point and can be processed, for example, in a corresponding ROI of the position. Instead of three positions and ROIs, as indicated in FIG. 3, in reality, for example, several hundred positions can be approached and processed per layer.

[0082] According to the present invention, the temperature data, as described above, are stored and/or captured at different positions of the additively constructed layer 1 (see method step a) further below). Furthermore, according to the invention, during the processing of the layer, for example along the positions P1 to P3, regulation data, for example comprising control parameters for the processing device, are stored and/or captured in a position-dependent manner and for each position (P1 to P3) (see method steps b) in FIG. 4 further below). Furthermore, according to the method described (see method steps c) in FIG. 4 further below), an adapted or optimized data record D′ is generated or provided from the captured data comprising regulation data R′ (see below) that are adapted in a position-dependent manner.

[0083] According to the method described, only the adapted regulation data, for example regulation data and a control parameter for a PID regulator as regulation device 103, or temperature data in addition to the adapted regulation data can be included in the adapted data record.

[0084] In the context of the described method, the regulation data to be captured can be captured and/or stored, for example, for each position on the layer again over a predetermined course of time (not explicitly identified in the figures). Ideally, the current internal values for the integration and differentiation (in the case of a PID regulator) are also stored.

[0085] Within the scope of the described invention, provision is made for the adapted data record to comprise, for example, by means of machine optimization methods, for example representing or comprising artificial neural networks or genetic or evolutionary algorithms. Alternatively, other optimization methods can be used to provide the adapted data record.

[0086] The described method, in particular the provision of the adapted data record, can furthermore be a recursive method, for example a method which is used again or iteratively for successive layers during the additive manufacturing of the component 10, for example in order to get better and better adapted values for each layer for the regulation parameters, and thus to optimize the temperature regulation and the process efficiency even further.

[0087] In a simple embodiment, it is not necessary to record the values for a complete layer or the complete component. The new or adapted parameters for the last processed position are then determined directly after heating and only the PID values (regulation parameters) for the next layer, for example layer 2, are stored.

[0088] In the case of small batches or large batches, it can be advantageous, for example in industrialized additive manufacturing, to store the determined parameters completely for all layers. Since the parameters determined actually apply to the current layer and not to the next one, the correct values can already be used in the current layer from the second component on, for example.

[0089] FIG. 4 summarizes method steps according to the invention using a schematic flowchart and indicates that the method described is a computer-implemented method, for example a method in which a computer program product or a corresponding computer program generates the adapted data record.

[0090] The method is a method for providing data D for temperature regulation in the additive manufacturing of the component 10. The method comprises a) capturing temperature data T in each case at different positions P1, P2 of an additively constructed layer 1.

[0091] The captured data D can be, for example, initial regulation data R, a control parameter SP, temperature data T or information relating to the captured temperature image (see above).

[0092] The method also comprises b) processing the layer 1 for the component 10 with a processing device 20 at the positions P of the layer 1, wherein regulation data R for regulating the processing device are captured in a position-dependent manner.

[0093] The method also comprises c) generating an adapted data record D′ from the captured data. In addition to the position-dependent, adapted regulation data R′, the adapted data record can, for example, comprise temperature data T or, for example, a control parameter SP for controlling or regulating the processing device 20. In particular, this method step can be implemented by means of a computer program or a corresponding computer program product CPP.

[0094] The invention is not restricted by the description based on the exemplary embodiments to these exemplary embodiments, but rather encompasses any new 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.