3D printing device with movable gas flow

Abstract

The invention relates to a device (1) for producing a three-dimensional workpiece, comprising a carrier (10) which is designed to receive a plurality of raw material powder layers, and an irradiation unit (11) which is designed to direct one or more irradiation beams (110a-d) onto predetermined points (100a-d) of an uppermost raw material powder layer in order to solidify the raw material powder at the predetermined points (100a-d). The device (1) further comprises at least one gas inlet (13) and at least one gas outlet (14), which are designed and arranged relative to one another in such a way that, during operation of the device (1), a gas flow (G) flows from the gas inlet (13) above the uppermost raw material powder layer in the direction of the gas outlet (14). The gas inlet (13) and the gas outlet (14) are designed to be moved together in a translational manner along a first axis (A1) above the uppermost raw material powder layer of the carrier (10).

Description

[0001] Page 1

[0002] Brose Fahrzeugteile SE & Co. Kommanditgesellschaft, Coburg Max-Brose-Straße 1 96450 Coburg

[0003] 3D printing device with movable gas flow

[0004] Description

[0005] The invention relates to a device and a method for producing a three-dimensional workpiece.

[0006] Powder bed fusion is an additive manufacturing process in which powdered raw materials, such as metals, ceramics, or polymers, are processed into three-dimensional (3D) workpieces using an energy source like a laser or electron beam. For this process, a layer of raw material powder is applied to a substrate using a powder deposition device. The raw material powder is then selectively exposed to radiation, depending on the desired geometry of the workpiece. The radiation penetrating the raw material powder layer causes it to heat up and subsequently melt or sinter the raw material powder particles. Further layers of raw material powder are then successively applied to the already irradiated layer until the workpiece has the desired shape and size.Examples of powder bed fusion processes include selective laser melting (SLM), selective laser sintering (SLS), and electron beam melting.

[0007] 2024 374 WO Page 2

[0008] Powder bed fusion allows for the production of various types of 3D workpieces, such as prototypes, tools, components, or medical prostheses, based on CAD data. This manufacturing process is therefore also known as 3D printing.

[0009] However, 3D printing processes regularly produce unwanted byproducts such as soot or weld spatter. To remove these byproducts, the top layer of raw material powder on the substrate, which is exposed to radiation for melting or sintering, is typically flushed with a gas stream. Often, (inert) shielding gases such as argon or nitrogen are used for this purpose. These shielding gases can displace gases present in the air within the printer chamber, such as oxygen, thus protecting the raw materials used to produce the workpiece from unwanted chemical reactions, such as oxidation. A uniform and homogeneous gas flow is therefore necessary to maintain consistent properties of the printed workpieces across the entire build area of ​​the printer. In particular, a laminar gas flow has proven to be especially advantageous.

[0010] However, it has become apparent that maintaining a uniform gas flow becomes increasingly difficult, if not impossible, as the size of the printer build chambers increases. Furthermore, with relatively large printer build chambers and when using multiple lasers in a single printer, it can be problematic that, despite striving for a uniform gas flow, some lasers located within the fume trail of a parallel, downstream laser on the same flow axis may be unable to operate. This is because an upstream fume trail emanating from one laser can undesirably influence the beam direction of a parallel laser operating upstream in the same direction. This can significantly impair the productivity of 3D printers with multiple lasers.

[0011] The object of the present invention is therefore to improve the productivity and production quality of 3D printing devices, especially those with large build volumes.

[0012] This problem is solved by an object having the features of claim 1.

[0013] Accordingly, a device for manufacturing a three-dimensional workpiece is provided. The device comprises a carrier designed to hold several layers of raw material powder.

[0014] 2024 374 WO Page 3

[0015] Within the scope of this disclosure, a plane parallel to a surface of the device's support (and therefore parallel to a top layer of raw material powder) is defined as the xy-plane of a Cartesian coordinate system used herein. A direction perpendicular to this plane is further defined as the z-direction. The cross-section of the support in the xy-plane can define the size of a build area. For example, the cross-section of the support is rectangular. The build area is the surface on which workpieces can be produced by the device through irradiation. The build area is preferably defined by the surface area of ​​the top layer of raw material. The build area is parallel to the surface of the support (and therefore parallel to the top layer of raw material powder).

[0016] The carrier can be movable in the z-direction in order to be lowered after completion of an irradiation process of a top layer of raw material powder, so that a new layer of raw material powder can be applied by a powder application device.

[0017] The device further comprises an irradiation unit. The irradiation unit is designed to direct one or more irradiation beams onto predetermined locations of an uppermost layer of raw material powder in order to solidify the raw material powder at these predetermined locations. Advantageously, the irradiation unit can include a radiation source, such as a laser. Alternatively, a particle source, such as an electron source, can also be provided. Depending on the radiation source, the solidification of the raw material can thus be achieved by SLM (selective laser melting) or SLS (selective laser sintering) in the case of a laser, or by electron beam melting when using an electron source.

[0018] Furthermore, the device comprises at least one gas inlet and at least one gas outlet. The gas inlet and the gas outlet are configured so that, during operation of the device, a gas flow runs from the gas inlet above the uppermost layer of raw material powder towards the gas outlet. For this purpose, a gas, such as an (inert) protective gas, can flow in through the gas inlet. The gas inlet can be a gas source or a gas feedthrough through which a gas from a (separate) gas source can flow in. The gas (flowing in through the gas inlet) can then exit through the gas outlet. Preferably, the gas outlet is designed such that it can selectively draw in and discharge the gas (flowing in through the gas inlet).

[0019] 2024 374 WO Page 4

[0020] This allows a gas flow between the gas inlet and the gas outlet.

[0021] For example, the gas outlet can include a suction device.

[0022] The gas inlet and outlet are arranged such that, during operation of the device, a gas flow runs from the gas inlet above the uppermost layer of raw material powder towards the gas outlet. For example, the gas inlet and outlet are arranged opposite each other in the xy-plane. This generates a gas flow that runs parallel to the uppermost layer of raw material powder. This, in turn, generates a uniform gas flow in the xy-plane above the uppermost layer of raw material powder for the removal of unwanted byproducts, such as soot.

[0023] Furthermore, the gas inlet and the gas outlet are designed to be moved translationally together along a (first) axis above the uppermost layer of raw material powder on the carrier. The (first) axis preferably runs parallel to the surface of the carrier and / or to the xy-plane. In the case of a rectangular cross-section of the carrier, the (first) axis can, for example, run along, i.e., parallel to, one side of the rectangular cross-section. The gas inlet and the gas outlet are thus movable together above the build area. This allows, particularly with large build areas, the distance between the gas inlet and the gas outlet to be selected as sufficiently small to generate a uniform and homogeneous, especially a laminar, flow between the gas inlet and the gas outlet, and to maintain this flow during operation of the device by moving the gas inlet and the gas outlet across the build area.At the same time, the translational mobility of the gas inlet and gas outlet allows the entire build area to be traversed, even if the distance between the gas inlet and gas outlet is narrower than the longitudinal extent of the build area, or allows for a particularly uniform and laminar gas flow in the respective working area of ​​the irradiation device, thus enabling a particularly efficient and reliable removal of unwanted by-products and, if necessary, a particularly reliable protection of the workpieces to be produced from unwanted chemical reactions.

[0024] In one example, the distance between the gas inlet and gas outlet is constant, regardless of their position in the device. This allows for the maintenance of a constant, and therefore particularly uniform and homogeneous, gas flow despite movement of the gas inlet and gas outlet during operation. This ensures a particularly uniform removal of unwanted substances.

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[0026] By-products along the entire path of the gas flow during operation of the device are permitted.

[0027] In one example, the support is planar. This means that the length and width of the support in the xy-plane are each greater than its height in the z-direction. The support's extent in the xy-plane is subsequently referred to as its principal extent plane. The (first) axis can run parallel to the principal extent plane of the planar support. This ensures that the gas flow between the gas inlet and the gas outlet during operation of the device reaches every point on the surface of the support, or rather the uppermost layer of raw material powder, along the travel path, and that at every point in the build area, the raw material powder layer being processed flows over it at a distance (in the z-direction) that is as uniform as possible.This ensures a particularly uniform and constant gas flow along the entire construction area, and thus a particularly reliable protection of the working areas of the irradiation facility from unwanted by-products.

[0028] During operation of the device, the gas flow can run parallel to the (first) axis. In particular, the gas inlet and outlet are arranged and configured such that the gas flow between them during operation runs parallel to the (first) axis. This allows any disturbances in the gas flow caused by the movement of the gas inlet and outlet along the (first) axis, such as turbulence, to be minimized, thus maintaining a laminar gas flow throughout the entire travel path of the gas inlet and outlet. The travel path or direction of travel of the gas inlet and outlet is, by way of example, opposite to the direction of gas flow. In this way, upstream soot can be carried in the opposite direction of the travel path.This ensures that when the device is operating in the working area of ​​the irradiation unit, which is always downstream of the previous position of the gas inlet and outlet according to the travel path, no soot is drawn into the irradiation beam area. This allows for particularly high productivity of the device.

[0029] In one example, the gas inlet and the gas outlet are arranged on a common axis of motion. Here, the axis of motion—in contrast to the (first) axis, which is a spatial axis—is a mechanical component, such as a...

[0030] 2024 374 WO Page 6

[0031] Linear axis. This has the advantage that only a few components, and in particular only one common (linear) drive, are needed to move the gas inlet and the gas outlet. Furthermore, moving the gas inlet and the gas outlet via a common axis of motion allows for a particularly smooth, simultaneous movement of both, thus maintaining a particularly constant gas flow during operation. The (common) axis of motion preferably runs parallel to the (first) axis.

[0032] The irradiation unit can be configured to direct irradiation beams (only) onto the area of ​​the uppermost raw material powder layer that is (currently) being overflowed by the gas stream. This makes it possible to minimize the working area, i.e., the area in which irradiation beams are directed onto the uppermost raw material powder layer and a gas stream is simultaneously generated, particularly in large build areas. This prevents interference, especially in multi-laser systems, such as upstream soot plumes from lasers operating in parallel above the build area, and thus increases the productivity of the device. Furthermore, this design allows the distance between the gas inlet and outlet to be kept as small as possible and configured in such a way as to ensure a laminar, i.e., particularly uniform and homogeneous, flow at every point in the build area during operation of the device.

[0033] The irradiation unit can comprise one or more lasers. Accordingly, the irradiation beams can be laser beams. Irradiation with laser beams enables particularly precise and detailed manufacturing of three-dimensional workpieces. Examples of processes that can be carried out with the proposed device include selective laser melting (SLM) and selective laser sintering (SLS).

[0034] In one example, the device comprises two gas inlets and two gas outlets. Each gas inlet and outlet can be arranged opposite each other with respect to the direction of extension of the (first) axis, and particularly in the xy-plane. This allows a gas flow to pass between each gas inlet and outlet. Preferably, the gas inlets and outlets are arranged alternately, i.e., gas inlet - gas outlet - gas inlet - gas outlet, and / or one after the other along the (first) axis. Such an arrangement with multiple gas inlets and outlets allows for a larger and preferably (almost) the

[0035] 2024 374 WO Page 7 The entire build area is to be covered with gas flow over the individual gas inlets and outlets with the shortest possible travel distance. A short or small travel distance results in fewer disturbances to the gas flow and allows for even more reliable maintenance of a constant gas flow between the respective gas inlets and outlets. Furthermore, with multiple gas inlets and outlets, and thus multiple working areas, it is possible for several lasers to operate in parallel, which in turn increases the productivity of the device.

[0036] In one variant, the gas inlets and outlets are arranged in a common plane parallel to the xy-plane. In this variant, the gas inlets and outlets can be arranged on a common axis of movement and all move together above the uppermost layer of raw material powder. For the advantages, please refer to the explanations above regarding the common axis of movement.

[0037] The design variants described so far with regard to one gas inlet and one gas outlet, and which will also be described below, can be freely transferred to the second gas inlet and the second gas outlet. For example, the respective distances between the gas inlet and gas outlet can be identical.

[0038] The raw material powder can be, for example, a metal or a metal alloy, such as stainless steel, aluminum, copper, or nickel. However, the raw material powder can also be ceramic or a plastic, such as a polymer.

[0039] In one example, one side of the support, particularly of the build area, has a length of at least 600 mm. The support can, for instance, have a rectangular cross-sectional area in the xy-plane. Accordingly, one side length of the rectangular cross-sectional area of ​​the support can be at least 600 mm. This allows the device to be built large, which in turn results in a relatively large build area on which a large number of three-dimensional workpieces can be produced in a single printing process.

[0040] The device can further include a coating unit for coating the workpiece produced by the device. For example, after the 3D workpiece has been produced, its surface can be finished using the coating unit. The coating unit can be positioned above the uppermost raw material powder layer along a

[0041] 2024 374 WO Page 8 The second axis must be translationally movable. Including a coating unit in the device allows for the production and finishing of the three-dimensional workpiece with just one device. Because the coating unit can also be movable, it can move across the entire build area and coat all manufactured workpieces.

[0042] The first and second axes can be independent of each other. For example, the first and second axes can be perpendicular to each other, particularly with respect to the main direction of extension of the support. With respect to the z-direction, the first and second axes can be skew to each other. This variant allows for independent movement of the gas inlet and outlet on the one hand and the coating unit on the other. For instance, it is conceivable to activate the coating unit and move it translationally across the build area only when a coating of the workpiece is actually planned following its production. Otherwise, for the sake of process efficiency, only the gas inlet and outlet can be moved across the build area.

[0043] In another variant, the first and second axes can run parallel to each other. This allows the coating unit to move in the same direction across the build area as the gas inlet and outlet. For example, the coating unit can be arranged on the same axis of movement as the gas inlet and outlet. This allows for a combined movement across the build area and, in particular, enables the irradiation of the top layer of raw material powder and simultaneous, or at least immediately subsequent, coating of the solidified raw material powder. This provides a device that allows for even more efficient and economical production of three-dimensional workpieces.

[0044] In this variant, a gas outlet and a gas inlet can each be arranged on one (common) side of the coating unit with respect to the extension direction of the first and second axes. This allows for coating on both sides with respect to the build area, i.e., either only on one side of the coating unit at a time or simultaneously on both sides.

[0045] Furthermore, in this variant, the (respective) gas inlet can be arranged closer to the coating unit than the (respective) gas outlet with respect to the direction of extension of the first and second axes. In particular, in this variant, the coating unit is located closer to the coating unit with respect to the direction of extension of the first axis.

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[0047] The first axis and the second axis are arranged between the gas inlets. This allows unwanted byproducts such as soot to be removed from the working area of ​​the coating unit.

[0048] According to another aspect, a method for manufacturing a three-dimensional workpiece is provided. The method comprises the following steps: In a first step, a layer of raw material powder is applied to a substrate. In a second step, one or more irradiation beams are directed onto one or more predetermined locations of the raw material powder layer using an irradiation unit in order to solidify the raw material powder at the one or more predetermined locations. It is provided that, at least during the directing of the irradiation beams onto predetermined locations of the raw material powder layer, a gas flow is maintained from a gas inlet towards a gas outlet above the raw material powder layer.The gas inlet and outlet are moved translationally together along an axis above the raw material powder layer, with the irradiation beams directed onto the raw material powder layer in an area that is covered by the gas flow between the gas inlet and outlet at the time of irradiation. Regarding the advantages, reference is made to the above information on the device.

[0049] Optionally, after completion or during an irradiation process of the uppermost raw material powder layer, a coating unit can be moved translationally across the build area to coat, and in particular refine, already produced (partial) areas of the workpiece. Alternatively, it can be provided that only after repeating the aforementioned process steps and completely producing all workpieces on the build area, these are coated using a coating unit that can be moved translationally across the build area.

[0050] The method is carried out in particular with a device according to any embodiment described herein.

[0051] The underlying concept of the invention will be explained in more detail below with reference to the exemplary embodiments shown in the figures. The figures show:

[0052] Fig. 1A shows a schematic top view of a device for producing a three-dimensional workpiece with a gas inlet and gas outlet movable over a build area and a coating unit;

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[0054] Fig. 1B shows the device according to Fig. 1A, wherein the gas inlet and the gas inlet above the construction area have been moved to a different position;

[0055] Fig. 2A shows a schematic top view of a device for producing a three-dimensional workpiece with two gas inlets and gas outlets movable over a build area and a coating unit;

[0056] Fig. 2B shows the device according to Fig. 2A, wherein the gas inlets and gas outlets above the build area have been moved to a different position;

[0057] Fig. 3A shows a schematic top view of a device for producing a three-dimensional workpiece with two gas inlets and gas outlets movable over a build area and a coating unit, wherein the gas inlets, gas outlets and the coating unit are movable along a common axis;

[0058] Fig. 3B shows the device according to Fig. 3A, wherein the gas inlets and gas outlets were moved to a different position together with the coating unit above the build area;

[0059] Fig. 3C shows the device according to Fig. 3A, wherein the working area has been moved to the construction site;

[0060] Fig. 4 Steps of a process for manufacturing a three-dimensional workpiece.

[0061] Figures 1A-3C show a schematic top view of a device 1 for manufacturing a three-dimensional workpiece. The device 1 comprises a carrier 10 designed to receive several layers of raw material powder. At the beginning of a manufacturing process for a three-dimensional workpiece, a layer of raw material powder, such as metal powder, can be applied to the carrier 10 as the top layer (not shown), for example, by means of a powder application device. The device 1 further comprises an irradiation unit 11. The irradiation unit 11 is designed to direct one or more irradiation beams 110a-d onto predetermined locations 100a-d of the top layer of raw material powder. The raw material powder can be applied to

[0062] 2024 374 WO Page 11 the predetermined locations are selectively solidified. The predetermined locations 100a-d on the uppermost layer of the raw material powder, onto which irradiation beams 110a-d are directed, correspond to a (partial) geometry of a workpiece to be manufactured.

[0063] In the example shown, the support 10 extends in the xy-plane of a Cartesian coordinate system. Furthermore, the support 10 is movable in the z-direction so that, after completion of an irradiation process of the uppermost layer of raw material powder, it can be lowered, for example, by a powder application device, allowing a new layer of raw material powder to be applied.

[0064] In the example shown, the beam 10 is planar. This means that the length and width of the beam 10 in the xy-plane are each greater than its height in the z-direction. Specifically, the beam 10 has a cross-sectional area in the xy-plane in the form of a rectangular area. The extent of the beam 10 in the xy-plane forms the principal plane E of the beam 10.

[0065] The cross-section of the carrier 10 in the xy-plane can define the size of a build area 12. The build area 12 is the surface on which workpieces are produced by the device 1 through irradiation. In other words, the build area 12 is defined by the area of ​​the top layer of raw material in the xy-plane. The build area 12 runs parallel to the cross-sectional area of ​​the carrier 10 (and therefore parallel to a top layer of raw material powder). For example, one side of the cross-sectional area of ​​the carrier 10 in the xy-plane, in particular of the build area 12, has a length of at least 600 mm.

[0066] The irradiation unit 11 can comprise a radiation source, such as a laser. Alternatively, a particle source, such as an electron source, can also be provided. Depending on the radiation source, the irradiation beams 110a-d can therefore be, for example, laser beams or electron beams. In a preferred embodiment, the radiation source is a laser and the irradiation beams 110a-d are accordingly laser beams. For example, the irradiation unit comprises a ytterbium fiber laser.

[0067] The irradiation unit 11 is designed to selectively direct the irradiation beams 110a-d onto the uppermost layer of raw material powder on the carrier 10. In this way,

[0068] 2024 374 WO Page 12 the raw material powder in the uppermost raw material powder layer - depending on the desired geometry of the workpiece to be produced - is selectively exposed to energy radiation and solidified.

[0069] The raw material powder can be, for example, a metal or a metal alloy, but it can also be ceramic or plastic.

[0070] As further shown in Figures 1A-3C, the device 1 comprises at least one gas inlet 13 and one gas outlet 14. Gas can flow into the device 1 via the gas inlet 13. The gas inlet 13 can be a gas source itself or a gas passage through which gas from a (separate) gas source can flow in. Gas, in this case the gas flowing in via the gas inlet 13, can flow out of the device 1 and / or into a gas circuit via the gas outlet 14. Preferably, the gas outlet 14 is designed to draw in and discharge the gas (flowing in via the gas inlet). For example, the gas outlet 14 can include a suction device (not shown). By allowing a gas to flow in through the gas inlet 13 and drawing in and removing the gas through the gas outlet 14, a gas flow G can be generated from the gas inlet 13 towards the gas outlet 14.

[0071] The gas inlet 13 and the gas outlet 14 are arranged above the surface of the carrier 10. In this way, during operation of the device 1, a gas flow G can flow from the gas inlet 13 above the uppermost layer of raw material powder towards the gas outlet 14. In the example shown, the gas inlet 13 and the gas inlet 14 are arranged opposite each other in the xy-plane. This allows a gas flow to be generated that flows parallel to the uppermost layer of raw material powder.

[0072] In the example shown, the gas flow G is represented by parallel arrows extending from the gas inlet 13 to the gas outlet 14. This symbolizes a preferably laminar gas flow G.

[0073] The gas inlet 13 and the gas outlet 14 are designed to be moved translationally together along a first axis A1 above the uppermost layer of raw material powder on the carrier 10. The first axis A1 runs parallel to the surface of the carrier 10 and also to the xy-plane. Furthermore, the first axis A1 runs parallel to the build area 12. In the example shown, the (first) axis A1 also runs parallel to one side of the rectangular cross-sectional area of ​​the carrier 10.

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[0075] The gas inlet 13 and the gas outlet 14 are thus jointly movable above the build area 12. In this way, a uniform and homogeneous laminar gas flow G can be generated between the (respective) gas inlet 13 and gas outlet 14. The gas flow G from the gas inlet 13 to the gas outlet 14 can be shifted and simultaneously maintained above the build area 12 by translational movement of the gas inlet 13 and the gas outlet 14.

[0076] In the illustrated embodiments, the distance between gas inlet 13 and gas outlet 14 is (in each case) smaller than the (minimum) longitudinal extent of the main extension plane E of the support 10 and also of the construction area 12. Furthermore, in the example shown, the distance between gas inlet 13 and gas outlet 14 is constant, regardless of their position in the device 1. This allows a constant, and therefore particularly uniform and homogeneous, gas flow G to be maintained despite movement of gas inlet 13 and gas outlet 14 during operation of the device 1. This ensures a particularly uniform removal of unwanted byproducts along the entire travel path of the gas flow G during operation of the device 1.

[0077] In the examples shown, the gas inlet 13 and the gas outlet 14 are arranged on a common axis of motion 15. Here, the axis of motion 15—in contrast to the first axis A1, which is a spatial axis—is a mechanical component, such as a linear axis. The axis of motion 15 runs parallel to the first axis A1.

[0078] In the examples shown in Figures 2A to 30, the device 1 comprises two gas inlets 13 and two gas outlets 14. Each gas inlet 13 and gas outlet 14 are arranged opposite each other with respect to the direction of extension of the first axis A1 and, in particular, in the xy-plane. This allows a gas flow G to flow between each gas inlet 13 and gas outlet 14. In the example shown in Figures 2A and 2B, the gas inlets 13 and gas outlets 14 are arranged alternately, i.e., gas inlet - gas outlet - gas inlet - gas outlet, one after the other along the first axis A1. In the device 1 according to Figs. 2A and 2B, the travel distances of the individual gas inlets 13 and gas outlets 14 are shorter than in the example according to Figs. 1A and 1B. A shorter or smaller travel distance results in fewer disturbances of the gas flow G during the process and allows for even greater efficiency.

[0079] 2024 374 WO Page 14 more reliable maintenance of a constant gas flow G between the respective gas inlet 13 and gas outlet 14.

[0080] In the example shown in Figures 2A and 2B, the gas inlets 13 and gas outlets 14 are arranged in a common plane parallel to the xy-plane. In this configuration, the gas inlets 13 and gas outlets 14 are arranged on a common axis of movement 15 above the uppermost layer of raw material powder. This allows all gas inlets 13 and gas outlets 14 to be moved together along the first axis A1 using only one component.

[0081] The irradiation unit 11 is designed to direct irradiation beams 110a-d (only) onto that area of ​​the uppermost raw material powder layer which is (currently) being overflowed by the gas stream G during operation of the device 1. The gas stream G thus defines a working area A for the irradiation unit 11. The working area A is the area in which irradiation beams 110a-d are directed onto the uppermost raw material powder layer and a gas stream G is simultaneously generated. This is illustrated in particular in Figures 1A-2B. From Figure 1A to Figure 1B, the gas inlet 13 and gas outlet 14 move in a direction V from left to right across the build area 12. Irradiation beams 110a-d are always directed by the irradiation unit 11 only onto predetermined locations 100a-d in that area of ​​the uppermost raw material powder layer which is overflowed by the gas stream G. This area is the depicted work area A. In the Fig.2A and 2B each have two gas inlets 13 and two gas outlets 14, thus providing two working areas A. Several irradiation beams operate simultaneously or in parallel within these two working areas A.

[0082] In the examples shown, exactly one irradiation unit 11 is provided in each case. However, it is also possible that, particularly in the case of multiple working areas A, several irradiation units 11 are provided, in particular one irradiation unit 11 per working area A. Alternatively or additionally, it is also conceivable that the irradiation unit 11 can move along the first axis A1 and / or along the direction of travel V, as shown, for example, in Figures 3A and 3B.

[0083] In the examples shown in Figures 1A to 30, the device 1 further comprises a coating unit 16. The coating unit 16 is designed to coat workpieces produced by means of the device 1 or already produced during the process.

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[0085] to coat (partial) areas of it. For example, after the production of a 3D workpiece, its surface can be finished using the coating unit 16. The coating unit 16 is, in this case, translationally movable above the uppermost raw material powder layer along a second axis A2. The coating unit 16 can thus move (translationally) across the entire build area 12 along the second axis A2.

[0086] The first axis A1 and the second axis A2 can be independent of each other, as shown in the examples in Figs. 1A-1B and 2A-2B. In these examples, the first axis A1 and the second axis A2 are perpendicular to each other with respect to the principal extension plane E of the support 10. With respect to the z-direction, the first axis A1 and the second axis A2 are skew to each other. This configuration allows for independent movement of the gas inlets 13 and gas outlets 14 on the one hand, and the coating unit 16 on the other. This allows the coating unit 16 to be moved translationally across the build area only when necessary, i.e., when coating of the workpiece is actually planned following its production.

[0087] In another variant, as shown in Figs. 3A-3C, the first axis A1 and the second axis A2 run parallel to each other. This allows the coating unit 16 to move in the same direction across the build area 12 as the gas inlets 13 and the gas outlets 14. In the example shown, the coating unit 16 is arranged on the same axis of movement 15 as the gas inlets 13 and the gas outlets 14. This allows for a combined process across the build area 12 and, in particular, for irradiating the uppermost raw material powder layer and simultaneously or at least immediately following coating the solidified raw material powder.

[0088] In the example with two gas inlets 13 and two gas outlets 14 according to Figs. 3A to 3C, one gas outlet 13 and one gas inlet 14 are each arranged on a common side of the coating unit 16 with respect to the extension direction of the second axis A2. This allows for coating on both sides with respect to the build area 12, i.e., either only on one side of the coating unit 16 at a time or simultaneously on both sides.

[0089] In the example shown in Fig. 3A-3C, the (respective) gas inlet 13 is arranged closer to the coating unit than the (respective) gas outlet 14 with respect to the direction of extension of the first axis A1 and / or the second axis A2.

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[0091] In this example, coating unit 16 is positioned between the gas inlets 13 with respect to the direction of extension of the first axis A1 and / or the second axis A2. This allows unwanted byproducts such as soot to be removed from the working area of ​​coating unit 16.

[0092] The direction of travel V of gas inlet 13 and gas inlet 14 runs in Figures 1A-3B opposite to the direction of flow of the gas stream G. Depending on the arrangement, however, the direction of flow can also coincide with the direction of travel V, as shown for example in Fig. 3C.

[0093] Fig. 4 shows a method for producing a three-dimensional workpiece, in particular with a device 1 of the type mentioned above. The method comprises the following steps (optionally in the exact order shown): In a first step S1, a layer of raw material powder is applied to a carrier 19. In a second step S2, one or more irradiation beams 110a-d are directed onto one or more predetermined locations 100a-d of the raw material powder layer by means of an irradiation unit 11 in order to solidify the raw material powder at the one or more predetermined locations 100a-d. It is provided that, at least during the directing of the irradiation beams 110a-d onto predetermined locations 100a-d of the raw material powder layer, a gas flow G flows from a gas inlet 13 towards a gas outlet 14 above the raw material powder layer.Parallel to the second step S2 and / or in a third step S3, the gas inlet 13 and the gas inlet 14 are moved translationally together along a (first) axis A1 above the raw material powder layer. The irradiation beams 110a-d are directed (only) in an area on the raw material powder layer that is covered by the gas flow G between the gas inlet 13 and the gas outlet 14 at the time of irradiation.

[0094] The underlying idea of ​​the invention is not limited to the embodiment described above, but can also be realized in other ways.

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[0096] Reference symbol list

[0097] I Device

[0098] 10 carriers

[0099] 100a-d predetermined positions

[0100] II Irradiation Unit

[0101] 110a-d Irradiation rays

[0102] 12 Building plot

[0103] 13 Gas inlet

[0104] 14 Gas outlet

[0105] 15 axis of movement

[0106] 16 coating units

[0107] A work area

[0108] A1 (first) axis

[0109] A2 (second) axis

[0110] E Main extent plane

[0111] G Gas flow

[0112] S1-S3 process steps

[0113] V Direction of travel

[0114] 2024 374 WO

Claims

Page 18 Claims 1. Device (1) for producing a three-dimensional workpiece, comprising - a carrier (10) designed to receive multiple layers of raw material powder; - an irradiation unit (11) designed to direct one or more irradiation beams (110a-d) onto predetermined locations (100a-d) of an uppermost raw material powder layer in order to solidify the raw material powder at the predetermined locations (100a-d); - at least one gas inlet (13) and at least one gas outlet (14) which are arranged and configured in such a way that, during operation of the device (1), a gas flow (G) flows from the gas inlet (13) above the uppermost raw material powder layer in the direction of the gas outlet (14); wherein the gas inlet (13) and the gas outlet (14) are designed to be moved translationally together along a first axis (A1) above the uppermost raw material powder layer of the carrier (10).

2. Device (1) according to claim 1 , characterized in that the distance between the gas inlet (13) and the gas outlet (14) is constant regardless of their position in the device (1).

3. Device (1) according to claim 1 or 2, characterized in that the support (10) is designed as a planar structure and the first axis (A1) runs parallel to the main extension plane (E) of the planar support (10).

4. Device (1) according to one of claims 1 to 3, characterized in that when the device (1) is in operation the gas flow (G) runs parallel to the first axis (A1).

5. Device (1) according to one of the preceding claims, characterized in that the gas inlet (13) and the gas outlet (14) are arranged on a common axis of movement (15) which runs parallel to the first axis (A1).

6. Device (1) according to one of the preceding claims, characterized in that the irradiation unit (11) is designed to operate 2024 374 WO Page 19 of the device (1) to direct irradiation beams (110a-d) onto the area of ​​the uppermost raw material powder layer which is overflowed by the gas stream (G).

7. Device (1) according to one of the preceding claims, characterized in that the irradiation unit (11) comprises one or more lasers and the irradiation beams (110a-d) are laser beams.

8. Device (1) according to one of the preceding claims, characterized in that two gas inlets (13) and two gas outlets (14) are provided, wherein one gas outlet (13) and one gas inlet (14) are arranged opposite each other with respect to the extension direction of the first axis (A1), such that a gas flow (G) can flow between the gas outlet (13) and the gas inlet (14).

9. Device (1) according to one of the preceding claims, characterized in that the raw material powder is metal.

10. Device (1) according to one of the preceding claims, characterized in that one side of the support (10) has a length of at least 600 mm.

11. Device (1) according to one of the preceding claims, characterized by a coating unit (16) for coating the workpiece produced by means of the device (1), wherein the coating unit (16) is translationally movable above the uppermost raw material powder layer along a second axis (A2).

12. Device (1) according to claim 11 , characterized in that the first axis (A1) and the second axis (A2) are perpendicular to each other.

13. Device (1) according to claim 11 , characterized in that the first axis (A1) and the second axis (A2) run parallel to each other.

14. Device (1) according to claim 13, insofar as it refers back to claim 5, characterized in that the coating unit (16) is arranged on the same axis of movement (15) as the gas inlet (13) and the gas outlet (14). 2024 374 WO Page 20 15. Device (1) according to claim 13 or 14, insofar as referring back to claim 8, characterized in that a gas outlet (13) and a gas inlet (14) are arranged on one side of the coating unit (16) with respect to the extension direction of the first axis (A1) and second axis (A2).

16. Device (1) according to claim 15, characterized in that the gas inlet (13) is located closer to the coating unit (16) than the gas outlet with respect to the direction of extension of the first axis (A1) and the second axis (A2). (14), in particular wherein the coating unit (16) is located between the gas inlets (13) with respect to the extension direction of the first axis (A1) and the second axis (A2).

17. Method for producing a three-dimensional workpiece, wherein the method comprises the following steps and is carried out in particular with a device (1) according to one of the preceding claims: - Applying a layer of raw material powder to a substrate (10); - Directing one or more irradiation beams (110a-d) onto one or more predetermined locations (100a-d) of the raw material powder layer by means of an irradiation unit (11) in order to solidify the raw material powder at the one or more predetermined locations (100a-d); wherein, at least during the directing of the irradiation beams (110a-d) onto predetermined locations (100a-d) of the raw material powder layer, a gas stream (G) flows from a gas inlet (13) towards a gas outlet (14) above the raw material powder layer, wherein the gas inlet (13) and the gas outlet (14) are moved translationally together along an axis (A1) above the raw material powder layer, and wherein the irradiation beams (110a-d) are directed onto the raw material powder layer in an area which, at the time of irradiation, is overflowed by the gas stream (G) between the gas inlet (13) and the gas outlet (14). 2024 374 WO

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