DE102018121136A1 - Layer construction device for additive manufacturing of at least one component area of a component, method for operating such a layer construction device and storage medium - Google Patents

Abstract

The invention relates to a layer construction device (10) for the additive production of at least one component area of a component (40) by an additive layer construction method. The layer construction device (10) comprises a process chamber (20), within which at least one construction field (I) for layer-by-layer construction of the component area from a material (56), at least one flow guiding device (16) which has at least one channel (36) with an outlet opening ( 14a) for introducing a protective gas into the process chamber (20), and a gas outlet device (30) which is stationary with respect to the construction field (I) for discharging the protective gas from the process chamber (20). The flow guide device (16) is designed to arrange an end region of the channel (36) of the flow guide device (16) surrounding the outlet opening (14a) above a level of the construction field (I) during operation of the layer construction device (10) and thus relative to the level of the construction field (I) that at least a predominant part of the protective gas can be conducted locally over a partial area of the construction field (I) along a main flow direction (H) which is at least substantially parallel to the plane of the construction field (I). The invention further relates to a method for operating such a layer construction device (10) and a storage medium with a program code for controlling such a layer construction device (10).

Description

The invention relates to a layer construction device for the additive production of at least one component area of a component, a method for operating such a layer construction device and a storage medium with a program code for controlling such a layer construction device.

In so-called additive or generative manufacturing processes (so-called rapid manufacturing or rapid prototyping processes), a component area or a complete component, which can be, for example, a component of a turbomachine or an aircraft engine, is built up in layers. Mainly metallic components are usually manufactured by laser or electron beam melting or sintering processes. First, a mostly powdery material is applied in layers in the area of a construction field or a build-up and joining zone in order to form a powder layer. The material is then solidified locally by supplying energy to the material in the area of the construction field by means of at least one energy beam, as a result of which the material melts or sinters and forms a component layer. The energy beam is controlled as a function of layer information of the component layer to be produced in each case. The layer information is usually generated from a 3D CAD body of the component and divided into individual component layers. After the molten material has solidified, the building platform is lowered in layers by a predefined layer thickness. Then the steps mentioned are repeated until the desired completion of the desired component area or the entire component. The component area or the component can in principle be produced on a construction platform or on an already generated part of the component or component area or on a support structure. The advantages of this additive manufacturing lie in particular in the possibility of being able to produce very complex component geometries with cavities, undercuts and the like in a single process.

The fact that zones with swirling of the powder layer or dust as well as other contaminants such as condensate, smoke or spatter, which accumulate in an uncontrolled manner on the construction site, on melted powder or on already solidified areas of the component layer, is problematic with these layer construction methods . This can lead to corresponding contamination, inclusions and process disruptions and ultimately to a reduction in component quality.

In order to reduce such problems, it is known to lead protective gas via a channel to a ceiling of a process chamber of the layer construction device used in order to generate a global protective gas stream, that is to say to the entire construction field, which flows from above into the process chamber onto the construction field and is discharged again via a global gas outlet device arranged in the process chamber in the area of the construction field in order to prevent the rise of smoke, dust, condensate and the like and to remove any contaminants. However, the protective gas flow must not be set too high, since it would otherwise stir up the powder layer. Such a global shielding gas flow is therefore only effective to a limited extent against the contaminants mentioned.

The object of the present invention is to provide a layer construction device and a method for operating such a layer construction device, which enable a process-reliable additive production of component layers of a component of higher quality. Another object of the invention is to provide a storage medium with a program code which ensures appropriate control of such a layer construction device.

The objects are achieved according to the invention by a layer construction device with the features of claim 1, by a method for operating such a layer construction device according to claim 14 and by a storage medium according to claim 15. Advantageous developments with expedient developments of the invention are specified in the respective subclaims, advantageous developments of each aspect of the invention being regarded as advantageous developments of the other aspects of the invention and vice versa.

A first aspect of the invention relates to a layer construction device for the additive production of at least one component region of a component by an additive layer construction method. The layer construction device has a process chamber, within which at least one construction field for layer-by-layer construction of the component area from a material, at least one flow guide device which comprises at least one channel with an outlet opening for introducing a protective gas into the process chamber, and a gas outlet device which is stationary with respect to the construction field for discharge of the protective gas from the process chamber are arranged. A process-reliable additive production of component layers of a component with a higher quality is achieved according to the invention in that the flow guiding device is designed to operate the layer construction device Arrange outlet opening, ie a gas inlet, comprising the end region of the channel of the flow guide device above a plane of the construction field and move it relative to the plane of the construction field in such a way that at least a predominant part of the protective gas runs locally over a sub-region along a main flow direction that is at least substantially parallel to the construction field plane of the construction site is conductive. In other words, in contrast to the prior art, it is provided that the flow guide device does not generate a global, but rather a local, protective gas stream, which accordingly does not affect the entire construction site, but only a sub-area of the construction site. In other words, the local protective gas flow does not flow within a volume of the process chamber that lies above the entire area of the construction field, but only within a volume of the process chamber that lies above a partial area of the construction field. The partial area or partial area can basically have an area that 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80%, 79%, 78%, 77%, 76%, 75%, 74%, 73%, 72%, 71%, 70%, 69%, 68%, 67%, 66%, 65%, 64%, 63%, 62% , 61%, 60%, 59%, 58%, 57%, 56%, 55%, 54%, 53%, 52%, 51%, 50%, 49%, 48%, 47%, 46%, 45 %, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12% , 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or less corresponds to the total area of the construction site, with corresponding intermediate values to be regarded as also disclosed. The extent of the local protective gas flow is determined in such a way that in the area of a projection, starting from the outlet opening of the channel, a flow speed is above a predetermined minimum speed and / or a volume flow is above a predetermined minimum value and / or a mass flow is above a predetermined minimum value and / or a flow direction lies within a predetermined maximum deviation, both a horizontal and a vertical expansion of the local protective gas flow being taken into account. Preferably, when determining the extent of the local protective gas flow, only a volume of the process chamber above the construction field that is close to the construction field is considered. For example, the predetermined minimum speed can be 30% or 50% of the maximum speed after the process gas has emerged from the outlet opening. For example, the predetermined maximum deviation can be 30 ° or 45 ° relative to the direction of flow that the protective gas flow has when exiting the outlet opening. Using these criteria, the local protective gas flow z. B. from turbulence or from undirected gas movements within the process chamber, but also from a globally overflowing protective gas stream according to the prior art. Due to the mobility of the outlet opening, the proportion of the area of the partial area of the construction field over which protective gas flows can be varied one or more times during a layer construction method carried out with the aid of the layer construction device. A simple possibility for setting the maximum possible partial area can be done, for example, by a corresponding choice or setting of the horizontal dimension of the outlet opening. Furthermore, the protective gas flow is generated by means of the flow guiding device in such a way that its main flow direction after emerging from the outlet opening of the channel is not perpendicular to the construction field, but rather at a distance parallel or approximately parallel to the construction field or to a plane that comprises the construction field. An at least substantially parallel main flow orientation of the protective gas flow is to be understood in addition to exactly parallel main flow orientations, that is to say main flows arranged exactly parallel to an x / y plane of the layer construction device, also slightly, that is to say main flow orientations deviating from an exactly parallel orientation by ± 20 ° , for example in terms of amount by 1 °, 2 °, 3 °, 4 °, 5 °, 6 °, 7 °, 8 °, 9 °, 10 °, 11 °, 12 °, 13 °, 14 °, 15 °, 16 °, 17 °, 18 °, 19 ° or 20 ° deviating main flow orientations, each measured at the outlet opening of the channel or an inlet device of the channel. The main flow orientation of the protective gas flow can be determined, for example, by the arithmetic mean of a number of flow directions, the individual flow directions or lines, for. B. measured, simulated or otherwise determined. However, the deviations should generally be limited to angles at which it is ensured that the protective gas flow is conducted over the powder layer at a distance from the powder layer and does not whirl it up or otherwise impair it. In this way, contaminants can be removed particularly reliably, since a comparatively strong protective gas flow can be generated directly in the region of the contaminants without the powder layer being undesirably whirled up. Due to the at least substantially parallel alignment, the previously required deflection of a protective gas flow directed perpendicular to the construction field can also be avoided. Any spreading or fanning out of the protective gas flow after exiting the channel can be tolerated and adequately controlled over short distances, for example by appropriate alignment and design of the outlet opening of the channel and by controlling the flow rate or the volume flow of the protective gas. Since the flow guide device according to the invention is also relative to the construction site If necessary, the channel or its outlet opening can be positioned where most contaminants occur at a certain point in time. Since only a local shielding gas stream has to be generated, the shielding gas volume required is also considerably less than in the case of global shielding gas streams, as a result of which the flow guide device according to the invention can be implemented more easily and causes lower operating costs. The channel is preferably configured as tubing or piping, which is connected, for example via an interface in a wall of the process chamber, to a gas supply arranged outside the process chamber, from which gas is transported within the channel to the outlet opening. The process chamber of the layer construction device comprises a cavity above the construction field, the construction field generally forms part of a bottom surface of the process chamber. The process chamber comprises (in particular vertically) ascending walls, the arrangement of which is often a z. B. follows a rectangular outline of the construction site and maintain a certain distance from the construction site. The cavity of the process chamber is closed at the top by a ceiling that z. B. be formed horizontally, but can also include slopes. The gas outlet device can be arranged in a wall of the process chamber and / or adjacent to or near an edge of the construction field. The inlet opening of the gas outlet device generally forms an essentially vertical interface between a cavity of a gas outlet downstream of the inlet opening and a cavity formed by the process chamber.

In summary, the flow guide device according to the invention enables a protective gas flow to be conducted over a distance between the mobile outlet opening of the channel and the stationary gas outlet device. In this way, the spreading of contaminants within the process chamber can be prevented particularly effectively and the contaminants can be transported to the gas outlet device more quickly and directly. Use of the flow guide device in conjunction with the immovable gas outlet device also advantageously makes it possible to dispense with one or more mobile, that is to say movable global or local gas outlet device (s) that can be moved relative to the construction site. In general, "one / one" are to be read as indefinite articles within the scope of this disclosure, ie without "explicitly stated otherwise" as "at least one / at least one". Conversely, "one / one" can also be understood as "only one / only one". Any suitable gas or gas mixture which does not lead to a deterioration in the component quality under the respective production conditions can generally be used as the protective gas. For example, the protective gas can comprise or be argon and / or another noble gas or noble gas mixture (He, Ne, Kr, Xe). The protective gas preferably has minimal impurities in oxygen, nitrogen, hydrogen and water (steam). The lowest possible contamination means contents of at most 20 ppm, in particular of at most 10 ppm or less.

In an advantageous embodiment of the invention it is provided that the layer construction device provides a powder feed for applying at least one powder layer of the material in the area of the construction field and / or at least one radiation source for generating at least one energy beam for layer-by-layer and local melting and / or sintering of the material a component layer by selectively irradiating the material with the at least one energy beam. The layer construction device can, for example, basically be designed as a selective laser sintering and / or laser melting device and have one or more lasers as the radiation source (s). For example, a CO ₂ laser, Nd: YAG laser, Yb fiber laser, diode laser or the like can be provided to generate a laser beam as an energy beam. It is also possible that the device is designed as an electron beam sintering and / or melting device, that is to say has one or more electron sources as radiation source (s) for generating an electron beam as an energy beam. Any combinations of electromagnetic radiation and particle radiation are also conceivable. Depending on the material used and the radiation strategy, melting and / or sintering of the material may occur during the irradiation, so that in the context of the present invention the term “welding” can also be understood to mean “sintering” and vice versa. The energy beam (s) are preferably coupled into or let into the process chamber via one or more regions of the process chamber wall and / or process chamber ceiling (e.g. coupling window) that are transparent to energy beams and cross the cavity of the process chamber on its way to the construction site, where he or she effect the selective solidification of the material locally.

In a further advantageous embodiment of the invention, it is provided that the flow guide device comprises at least one guide surface segment for limiting a spread of the protective gas introduced into the process chamber. With the aid of the at least one guide surface segment, the typical spread of an unguided protective gas flow can be limited on one, two, three or more sides and / or the protective gas flow can be directed. This means that contaminants can be removed more precisely and effectively. At least one The guide surface segment provides in a structurally simple manner a pressure side which can be optimally adapted to the respective application and by means of which the protective gas flow can be limited and / or directed in a desired direction. In its simplest configuration, the guide surface segment can be designed as a “guide plate” or guide plate, wherein the guide surface segment can in principle be formed from metallic and / or non-metallic materials or composite materials. Furthermore, the guide surface segment can be straight or curved depending on the desired flow guidance. The at least one guide surface segment is preferably designed as a component of the flow guide device that is separate from the channel or its outlet opening. As a result, a distance between the guide surface segment and the outlet opening can be variably set. This represents a considerable gain in flexibility due to the ability to coordinate the relative movements of the outlet opening and guide surface segment within the process chamber.

It can be provided that the at least one guide surface segment is at least partially (high) energy beam transparent, in particular laser transparent. This makes it possible, for example, to form a flow guide channel through which the material can nevertheless solidify due to the (high) energy-beam-transparent property of the guide surface segment. For example, the guide surface segment can be partially or completely laser-transparent, so that a laser beam can be directed through the guide surface segment onto the material in order to selectively solidify it. An electron beam transparent embodiment can also be provided. Alternatively or additionally, the at least one guide surface segment consists at least in regions of a non-induction material, in particular of a high-temperature-resistant plastic, of a ceramic, of a composite material or of any combination thereof. As a result, the guide surface segment can advantageously be used in connection with inductive heating devices or be arranged in the vicinity thereof, without undesired heating of the guide surface segment due to induced currents. In the context of the present disclosure, a high-temperature-resistant plastic is understood to mean high-performance plastics with high temperature resistance, which have a continuous use temperature of at least 150 ° C., in particular of at least 300 ° C. An example of such a high-performance plastic is polyether ether ketone (abbreviated PEEK), which belongs to the group of polyaryl ether ketones and has a melting temperature of about 335 ° C. However, other high-performance plastics, combinations of several high-performance plastics and composite materials with one or more high-performance plastics can generally also be used to produce the guide surface segment. Other suitable non-inductive materials can also be used, such as ceramic materials. In general, non-magnetic metals or metal alloys can also be provided.

It has proven to be advantageous if the at least one guide surface segment has a longitudinal extent of at least 50%, preferably of at least 70% and particularly preferably of at least 100%, that is to say of 50%, 51%, 52%, 53%, 54% , 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71 %, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100% or more of a construction site side and / or a construction site diameter of the construction site . As a result, the proportion of the distance between the outlet opening of the channel of the flow guiding device functioning as local gas supply and the inlet opening of the gas outlet device, along which the flow guiding device conducts the protective gas flow at least in sections, can be optimally adjusted and, if appropriate, in a corridor over the entire length of the construction site (100%) be realized. As an alternative or in addition, it is provided that the at least one guide surface segment and the end region of the channel of the flow guide device which comprises the outlet opening can be moved relative to one another. As a result, the outlet opening can be moved, for example, along the guide surface segment, the guide surface segment permanently limiting and guiding the inert gas flow.

Further advantages result from the fact that the flow guide device comprises at least two guide surface segments which are arranged opposite one another and / or which limit an outlet opening of the channel of the flow guide device for the protective gas in relation to the construction site. As a result, the protective gas flow can be limited and guided on two or more sides. By arranging the at least two guide surface segments to be fixed relative to one another or movable relative to one another, either a constant or a variable limitation or flow guidance of the protective gas flow can be realized. For example, two or more guide surface segments can be moved translationally relative to one another, for example displaceable and / or telescopic into one another, in order to allow a variable geometry of a flow channel formed or limited by the guide surface segments. This enables optimized flow control with differently dimensioned component layers. Alternatively or additionally, two or more guide surface segments can be rotated relative to one another, for example tilted or pivoted, in order to realize a limitation or deflection of the protective gas flow.

In a further advantageous embodiment of the invention it is provided that at least one guide surface segment at an angle between 60 ° and 120 °, that is to say for example at an angle of 60 °, 61 °, 62 °, 63 °, 64 °, 65 °, 66 ° , 67 °, 68 °, 69 °, 70 °, 71 °, 72 °, 73 °, 74 °, 75 °, 76 °, 77 °, 78 °, 79 °, 80 °, 81 °, 82 °, 83 °, 84 °, 85 °, 86 °, 87 °, 88 °, 89 °, 90 ° 91 °, 92 °, 93 °, 94 °, 95 °, 96 °, 97 °, 98 °, 99 °, 100 °, 101 °, 102 °, 103 °, 104 °, 105 °, 106 °, 107 °, 108 °, 109 °, 110 °, 111 °, 112 °, 113 °, 114 °, 115 °, 116 °, 117 °, 118 °, 119 ° or 120 ° to the construction site. In other words, the guide surface segment is arranged perpendicularly (90 °) to the construction field or to a plane which encompasses the construction field, wherein inclinations of up to ± 30 ° can be provided. As a result, the spread of the protective gas flowing essentially parallel to the construction site can be limited on one or more sides and directed or, if necessary, deflected. For example, the protective gas flow can be limited or directed transversely to the main flow direction, that is to say perpendicularly, with a deviation of up to ± 30 °. This allows the spreading of the protective gas flow on one or more sides and a more precise and effective removal of impurities. Furthermore, it can be provided that, based on the construction field, a highest point of at least one guide surface segment is at a greater distance from the construction field during operation of the layer construction device than a highest point of an outlet opening of the channel of the flow guide device. In other words, the guide surface segment - measured at right angles from the construction site - projects beyond the outlet opening at least in some areas. This advantageously prevents overflow of the guide surface segment and thus a deterioration in its conductivity. For example, it can be provided that at least one guide surface segment, in whole or in part, based on the construction site, is at least 1 cm, that is to say for example by 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, 1.5 cm, 1.6 cm, 1.7 cm, 1.8 cm, 1.9 cm, 2.0 cm, 2.1 cm, 2.2 cm, 2.3 cm, 2.4 cm, 2.5 cm, 2.6 cm, 2.7 cm, 2.8 cm, 2.9 cm, 3.0 cm, 3.1 cm, 3.2 cm, 3.3 cm, 3.4 cm, 3.5 cm, 3.6 cm, 3.7 cm, 3.8 cm, 3.9 cm, 4.0 cm, 4.1 cm, 4.2 cm, 4.3 cm, 4.4 cm, 4.5 cm, 4.6 cm, 4.7 cm, 4.8 cm, 4.9 cm, 5.0 cm, 10 cm, 15 cm, 20 cm or more, extends over the highest point of the outlet opening . In other words, the guide surface segment projects above the outlet opening in the direction away from the construction site, as a result of which an “overflow” of the shielding gas flow and thus a deteriorated shielding gas flow guidance are reliably prevented.

As an alternative or in addition, it is provided that, based on the construction site, a deepest point of at least one guide surface segment has a smaller distance from the construction site during operation of the layer construction device than a deepest point of an outlet opening of the channel of the flow guide device. This advantageously prevents an underflow of the guide surface segment and thus a deterioration in its conductivity and any swirling of the material. It can be provided that at least one guide surface segment at a distance of at least 0.5 cm and / or at most 5 cm, that is to say for example of 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, 1.5 cm, 1.6 cm, 1.7 cm, 1.8 cm, 1.9 cm, 2.0 cm, 2.1 cm, 2.2 cm, 2.3 cm, 2.4 cm, 2.5 cm, 2.6 cm, 2.7 cm, 2.8 cm, 2.9 cm, 3.0 cm, 3.1 cm, 3.2 cm, 3.3 cm, 3.4 cm, 3.5 cm, 3.6 cm, 3.7 cm, 3.8 cm, 3.9 cm, 4.0 cm, 4.1 cm, 4.2 cm, 4.3 cm, 4.4 cm, 4.5 cm, 4.6 cm, 4.7 cm, 4.8 cm, 4.9 cm or 5.0 cm above the material or construction field or can be arranged. This ensures that the guide surface segment is at a sufficient distance from the material and does not whirl up or otherwise disturb it even when it is moved over the material. At the same time, it is ensured that contaminants arising in the area of the material, for example smoke or spatter, can be reliably detected and removed by the protective gas flow.

The outlet opening of the channel and at least two guide surface segments of the flow guide device are preferably designed and oriented to one another such that, in operation, the two guide surface segments on opposite sides of the outlet opening are preferably arranged parallel to one another and spaced apart such that they frame the outlet opening or delimit it on both sides , wherein the outlet opening is preferably movable along (for example in a direction parallel to) a longitudinal extension of the guide surface segments.

In a further advantageous embodiment of the invention, it is provided that at least one guide surface segment of the flow guide device forms an upper side in relation to the construction field and / or that at least one guide surface segment of the flow guide device forms a lower side in relation to the construction field. This makes it possible to control the flow of protective gas upwards and / or downwards and to define the limits of the expansion of the gas flow upwards, that is to say away from the construction site, and / or downwards, that is to say towards the construction site. Furthermore, with the aid of the guide surface segment or the guide surface segments, a channel that is predominantly or completely closed in cross section can be formed, as a result of which particularly efficient and trouble-free removal of impurities is made possible. In order to nevertheless ensure the passage of an energy beam used to solidify the material onto the construction site, it has proven to be advantageous if at least one guide surface segment of the flow guide device clears a passage opening for an energy beam, at least during operation of the layer construction device. This ensures that a visual axis is released for the energy beam, so that it is not hindered by the flow guide device and can strike the construction field from a ceiling area of the device through the passage opening and selectively solidify the material. In general, two or more passage openings can also be provided, which expose one or more visual axes between the construction field and a ceiling area of the process chamber or an entry area of the energy beam of the radiation source into the process chamber. The passage opening (s) in the simplest embodiment can be cutouts or holes in the relevant guide surface segments through which both the energy beam and gas can pass, thereby advantageously preventing congestion effects. Alternatively, at least one passage opening can be formed from a gas-impermeable material that is transparent to the energy beam.

In a further advantageous embodiment of the invention, it is provided that a position of the flow guide device within the process chamber relative to the construction field as a function of a position of an impact surface of the energy beam and / or as a function of a position, orientation or extent of a current work area of the energy beam within the construction field, e.g. B. a radiation strip or checkerboard field or generally a localized radiation zone as a portion of an object to be irradiated in a layer cross-sectional area on the construction field is adjustable and / or that the flow control device at least substantially simultaneously with the impact surface of the energy beam on the construction field or with the work area is movable relative to the construction site. In this way, contaminants, which predominantly arise when the energy beam strikes the material, can be removed particularly reliably.

Further advantages result from at least one guide surface segment having a changeable geometry and / or from the fact that at least one longitudinal extent of the flow guide device can be set. This enables a particularly flexible adaptation to different construction site and component geometries. For example, the guide surface segment can have a bendable or bendable guide surface. Changes in shape by means of hinges, a curtain or the like are also conceivable in order to direct the protective gas flow along a non-linear flow path. A longitudinal extent of the flow guiding device can be changeable, for example, in that one or more guiding surface segments can be telescoped.

In a further advantageous embodiment of the invention, it is provided that the layer construction device comprises a further flow guiding device in the region of an upper side of the process chamber, by means of which a global protective gas flow with an essentially perpendicular main flow direction with respect to the construction field can be generated. The process chamber can thus be filled with a protective gas atmosphere during the layer construction process, the protective gas atmosphere preferably having a pressure between 50 mbar and 1200 mbar, that is to say for example with 50 mbar, 100 mbar, 150 mbar, 200 mbar, 250 mbar, 300 mbar, 350 mbar , 400 mbar, 450 mbar, 500 mbar, 550 mbar, 600 mbar, 650 mbar, 700 mbar, 750 mbar, 800 mbar, 850 mbar, 900 mbar, 950 mbar, 1000 mbar, 1050 mbar, 1100 mbar, 1150 mbar or 1200 mbar can be provided in the process chamber. The protective gas in the protective gas atmosphere can preferably have the same or a similar composition as the protective gas stream discharged from the local flow control device over the construction site. For example, argon can be used both for the protective gas stream and for the protective gas atmosphere. It can be provided that the protective gas discharged from the local flow guide device is filtered after removal via the gas outlet device in order to remove discharged pollutants, and is then used as protective gas for the global protective gas atmosphere in the process chamber. The protective gas atmosphere in the process chamber can in principle be conducted in a circuit which may be provided with a filter system in order to avoid losses. Because of the first, local flow guide device, the flow velocity or the volume flow of the protective gas can be reduced compared to layer construction devices without such a local flow guide device, as a result of which turbulence in the material is particularly reliably prevented.

In a further advantageous embodiment of the invention, a support device is provided, by means of which at least the end region of the channel of the flow guiding device that comprises the outlet opening and / or at least one guide surface segment can be moved in at least one spatial direction relative to the construction field within the process chamber. This represents a structurally simple possibility for positioning the outlet opening and / or at least one guide surface segment in relation to the construction field. The carrying device is preferably arranged partially or completely within the process chamber. The end region of the channel and / or the guide surface segment can or can be fixed directly or indirectly to the carrying device. The carrying device is preferably designed in such a way that it can evade a possibly existing coater or a powder feeder for applying a powder layer on the building site or that the carrying device and the coater can be moved over the building site without interfering with one another. For this purpose, the carrying device and the coater can be movable, for example, in mutually perpendicular directions of travel at similar height levels or can be moved at different height levels above the construction site.

Further advantages result from the fact that the carrying device comprises at least two supporting arms, each movable relative to the construction field. The support arms can each have one or more degrees of translational freedom and / or one or more degrees of rotational freedom. The first support arm can preferably be moved in exactly one first spatial direction and the second support arm can be moved in the first spatial direction and in a second spatial direction, the second spatial direction being perpendicular to the first spatial direction. For example, it can be provided that one of the support arms can be moved in the y direction of the process chamber, while the other support arm can be moved in the x direction, the x and y directions being defined by the side edges of the construction field. Preferably, at least one guide surface segment is coupled to one of the support arms, so that it moves with it during operation, while the end region of the channel of the flow guiding device comprising the outlet opening is coupled to the other support arm, so that the outlet opening moves with it during operation. Likewise, the at least one guide surface segment and / or the end region of the channel comprising the outlet opening can be moved independently of the construction field, for example by means of a robot arm. The inlet opening of the gas outlet device preferably has a horizontal dimension which essentially corresponds to a horizontal dimension of an adjacent construction site side, particularly preferably has at least the length of the immediately adjacent construction site side. This embodiment proves to be advantageous, for example, if the at least one guide surface segment can only be moved or moved in a single spatial direction relative to the construction field and this spatial direction essentially corresponds to the orientation of a longitudinal extension of the inlet opening. As a result, the local gas flow and impurities in the process chamber atmosphere carried along or displaced by it can be independent of the position of the flow guide device, ie. H. of the duct, its outlet opening and / or the guide surface segment or segments, are transported relative to the construction field directly in the direction of or up to the inlet opening of the gas outlet device and are subsequently removed from the process chamber.

In a further advantageous embodiment of the invention, it is provided that the layer construction device comprises a heating device, by means of which the construction site can be tempered at least in some areas. As a result, even materials that are difficult to melt, such as highly heat-resistant nickel-base superalloys, Mg ₂ Si alloys and intermetallic compounds such as titanium aluminides, can be processed using welding technology because these materials can be preheated using the heating device and preheated to temperatures near their melting point. Furthermore, already solidified material can be heat-treated and / or cooled in a controlled manner using the heating device. The heating device can in principle comprise one or more radiant heaters (IR, microwave, etc.) and / or one or more inductive temperature control devices in order to heat electrically conductive areas in the process chamber of the layer construction device with the help of one or more induction elements due to eddy current losses.

In a further advantageous embodiment of the invention it is provided that the heating device comprises at least a first induction coil and a second induction coil, the first induction coil being fixed on the first support arm and the second induction coil on the second support arm. As a result, the magnetic fields of the induction coils can be deliberately superimposed in order to carry out a temperature control of a selected area of the construction field as required. The induction coils can be moved independently of one another. The second induction coil is preferably made smaller than the first induction coil and can only be moved within a region delimited by the first induction coil. In a further embodiment, the at least two induction coils can be movable with respect to one another in a translatory and / or rotary manner, as a result of which their relative positioning in relation to one another can be set particularly precisely and as required. This permits a correspondingly precise heating of the material or the component layer, in that the magnetic fields of the induction coils can be deliberately superimposed in the desired areas.

In a further advantageous embodiment of the invention, a drive of the heating device is also used synergistically for driving the flow guide device and / or the introduction device. This is appropriate since a heating area of the heating device and a flow target area of the flow guide device and / or the introduction device are at least immediately adjacent to one another, ie adjacent to one another, in the process chamber are arranged. They preferably form an intersection at least in an orthogonal projection of the heating area and the flow target area onto a plane of the construction field. In other words, under certain conditions, a target work area to which the heating device is moved in the horizontal direction can also be a target work area of the flow guide device and / or the introduction device and vice versa. The intersection is understood to mean, in particular, a partial area of the construction field. The heating area is understood in particular to mean a volume of solidified or unconsolidated material which is heated directly or indirectly by the heating device. It is taken into account that, for example, when using an inductive heating device, an uppermost layer of the unconsolidated material on the construction site can be largely indirectly heated (by heat conduction) by heat from a directly heated solid body lying below the uppermost material layer or previously solidified area in the environment, ie in the surrounding material. From the use of this principle for heating one or fewer layers of material lying / lying between a component or a construction platform and the process chamber atmosphere, it can be seen that the indirectly heated area, which by definition is above a predetermined minimum temperature, has a very small spatial extent can the z. B. a few or a few dozen micrometers (at least in a vertical direction perpendicular to the construction field). This also means that the indirectly heated, locally limited area below the surface of the material (including the surface) moves with a corresponding amount even with a slight horizontal displacement of the directly heated area arranged below it. The flow target area is understood to be a partial volume of the process chamber that connects to the construction field immediately above the construction field. The flow target area preferably comprises a surface of the uppermost layer of the material on which a gas stream strikes, or along which a gas stream flows, or over which a gas stream flows. It is taken into account here that a gas flow introduced into the process chamber by means of the introduction device arranged outside the material generally has essentially no depth effect into the material, ie essentially does not penetrate below the surface of the uppermost material layer. A position or movement of the heating device and the heating area generated by it thus determines a position or movement of the flow target area defined by the flow guide device and / or the introduction device. The position or movement of the heating device and / or the flow guide device and / or the introduction device is preferably controlled or regulated in such a way that intersections of the flow target area with the construction field and the heating area with the construction field occur at least during one step of processing the material (e.g. B. in the form of selective solidification) form as large an intersection as possible.

If, for example, the above-mentioned “cross-coil” is used as the heating device, which comprises two inductors that can be moved relative to one another in order to be able to overlay the individual induction fields, the introduction device requires for the outlet opening, ie. H. the gas inlet, which generates a locally limited process gas flow, its own drive or support arm or at least has to be movable in such a way that it can be moved or moved with the overlapping area of the two inductors, that is to say the most intensive heating area of the heating device.

In this embodiment of the heating device, it can then be provided that the introducing device and / or the flow guiding device are attached indirectly or directly to the induction coils or respectively indirectly or directly to an induction coil or jointly to an associated support arm of the carrying device. It can also be provided that the introduction device and / or the flow guide device can be moved at least together with the induction coils or the respectively assigned induction coils with the aid of one or more separate support arms. A common process with the induction coils fully fulfills the goals of the guided flow depending on the heating area, in particular with regard to avoiding undesirable contamination in the assembly and joining area.

A further independent inventive concept lies in coupling the mobility of the flow guide device and / or the introduction device to a selected operating mode of the flow and / or the heating. This can be controlled or regulated, for example, with the aid of a correspondingly designed control device or control unit of the layer construction device. For example, a first, “active” operating position can be provided, in which the local gas inflow and the conduction of the local gas flow take place. This operating position of the heating device and the flow guiding device and / or the introductory device above the construction field is suitable for heating or flow and, as described above, can provide mobility in all degrees of freedom or restricted to degrees of freedom that are appropriate for the respective application. In a second, "inactive" operating position, on the other hand, there is no local gas inflow or no conduction of the local gas flow. This operating position preferably includes moving the Flow guiding device and / or the introducing device into an area outside the travel movement of a coater of the layer building device in order not to hinder the application of a new powder layer.

For example, a method or moving the heating device and / or the flow guiding device and / or the introducing device into a lateral parking position and / or moving or pivoting upwards (z direction) into the free space of the process chamber can be provided. Moving upwards in particular offers the advantage of high operational reliability, since in a region of the process chamber that is close to the ceiling or away from the construction area, typically neither the coater nor other components are moved, and there is therefore no need for additional coordination. The "inactive" operating position can e.g. B. can also be selected during set-up, cleaning, flooding etc. of the layer construction device or in non-process times. This control or regulation of the operating positions of the heating device and / or the flow guide device and / or the introduction device generally represents a separate aspect of the invention, which can be implemented independently of the other aspects of the invention.

Further advantages result from the fact that the end region of the channel of the flow guide device comprising the outlet opening and / or at least one guide surface segment is fixed on the heating device and / or that the end region of the channel of the flow guide device comprising the outlet opening and / or at least one guide surface segment is dependent on a movement the heater is movable. Since the heating device is used for tempering a region of the component to be solidified, a part of the component to be solidified and / or an already solidified area, a common arrangement or mobility is advantageous, since this ensures that the protective gas always has a particular value for the component quality relevant area of the material. Any contaminants are removed particularly reliably, so that a particularly high component quality is guaranteed.

A particularly precise alignment of the main flow direction of the protective gas is achieved in a further embodiment in that the end region of the channel of the flow guiding device comprising the outlet opening comprises a nozzle. The length of the nozzle can have a constant opening cross-sectional area, alternatively the opening cross-sectional area can widen, taper or have complex geometries.

In an advantageous embodiment of the invention, it is provided that the flow guiding device is designed to direct the main flow direction of the protective gas towards the at least one inlet opening of the gas outlet device during operation of the layer construction device such that the main flow direction has an inclination of at most 30 °, for example of 30 ° , 29 °, 28 °, 27 °, 26 °, 25 °, 24 °, 23 °, 22 °, 21 °, 20 °, 19 °, 18 °, 17 °, 16 °, 15 °, 14 °, 13 °, 12 °, 11 °, 10 °, 9 °, 8 °, 7 °, 6 °, 5 °, 4 °, 3 °, 2 °, 1 ° or 0 ° relative to a plane parallel to the construction site, preferably relative to a horizontal. In other words, it is provided that the main direction of flow of the protective gas flow or a virtual line connecting the outlet opening and the inlet opening is oriented at least approximately parallel to the construction field or horizontally, in order to deflect the protective gas along with any entrained contaminants accordingly over the construction field with little deflection and turbulence to conduct and discharge from the process chamber. In addition to a particularly reliable removal of interfering particles, undesirable process gases, etc., this also reliably prevents an undesirable whirling up of the material, since the protective gas flow does not hit a wall, ie. H. is directed or deflected to a flow resistance. This can increase the component quality accordingly. As an alternative or in addition, it is provided that the flow guide device is designed to direct the main flow direction of the protective gas toward the at least one inlet opening of the gas outlet device during operation of the layer construction device such that the main flow direction is arranged parallel or coaxially to a normal of an opening cross section of the inlet opening of the gas outlet device . In other words, it is provided that the surface or plane of the outlet opening and the surface or plane of the inlet opening are at least essentially parallel to one another during operation of the layer construction device. This allows a particularly low-swirling introduction and extraction or removal / discharge of the protective gas and any entrained contaminants from the process chamber.

In a further advantageous embodiment of the invention, it is provided that the outlet opening of the channel and / or the at least one inlet opening of the gas outlet device is arranged closer to the construction field than to a process chamber ceiling during operation of the layer construction device. In other words, it is provided that the outlet opening of the flow guide device and / or the inlet opening of the gas outlet device is or are arranged near the construction site during operation, i.e. closer to the construction site than to the process chamber ceiling, preferably in a lower half of the process chamber, more preferably in the bottom third and particularly preferably in the lowest quarter of a clear height, that is to say a maximum inner height, of Process chamber (viewed vertically or perpendicular to the construction field).

A second aspect of the invention relates to a method for operating a layer construction device according to the first aspect of the invention, in which before, during and / or after an additive production of at least one component region of a component by an additive layer construction method by means of the flow guide device, the end region of the channel of the flow guide device comprising the outlet opening Arranged above the level of the construction field and is moved relative to the level of the construction field in such a way that at least a predominant part of the protective gas emerging from the outlet opening is passed locally over a partial region of the construction field along a main flow direction parallel to the construction field. In this way, a more reliable additive manufacturing of component layers of a component with higher component quality can be achieved, because before, during and / or after the solidification of a component layer, a targeted, locally limited removal of swirled material, dust, condensate, smoke, splashes and / or other contaminants is ensured by means of the local protective gas flow. The protective gas stream is preferably introduced or injected at a predetermined distance from the powder layer and at least substantially parallel to the construction site, that is to say in the x / y plane of the layer construction device (± 30 ° deviation from the x / y plane, ie possible in the z-direction) to prevent the material from being whirled up. This represents a structurally simple and inexpensive way to reliably keep at least selected areas and in particular the current consolidation point or the current working area of the at least one energy beam from smoke, condensate or other contaminants by a directed, local protective gas flow. Any suitable gas or gas mixture that is compatible with the respective production conditions can generally be used as the protective gas. For example, the protective gas can comprise or be argon and / or another noble gas or noble gas mixture (He, Ne, Kr, Xe). The protective gas preferably has minimal impurities in oxygen, nitrogen, hydrogen and water (steam). The lowest possible contamination means contents of at most 20 ppm, in particular of at most 10 ppm or less. To carry out the method according to the invention, the layer construction device can comprise a basically optional control device. The control device can have a processor device which is set up to carry out an embodiment of the method according to the invention. For this purpose, the processor device can have at least one microprocessor and / or at least one microcontroller. Furthermore, the processor device can have a program code which is set up to carry out the embodiment of the method according to the invention when executed by the processor device. The program code can be stored in a data memory of the processor device. In the context of the present disclosure, the expression “trained to” is to be understood in such a way that not only is it general suitability, but that specifically hardware and / or software-based measures are implemented and configured to carry out the steps mentioned in each case. Further features and their advantages result from the description of the first aspect of the invention, advantageous configurations of the first aspect of the invention being regarded as advantageous configurations of the second aspect of the invention and vice versa.

A third aspect of the invention relates to a storage medium with a program code, which is designed to control a layer construction device according to the first aspect of the invention when it is executed by a computing device so that it carries out a method according to the second aspect of the invention. The features resulting from this and their advantages can be found in the descriptions of the first and second aspects of the invention, advantageous configurations of the first and second aspects of the invention being regarded as advantageous configurations of the third aspect of the invention and vice versa.

• 1 eine schematische und teiltransparente Perspektivansicht einer erfindungsgemäßen Schichtbauvorrichtung gemäß einem ersten Ausführungsbeispiel;
• 2 eine schematische Perspektivansicht einer Einleiteinrichtung und einer Heizeinrichtung, die an einem Tragarm angeordnet sind;
• 3 eine schematische Perspektivansicht der Einleiteinrichtung und Strömungsleiteinrichtung, die gemeinsam an dem Tragarm angeordnet sind;
• 4 eine schematische seitliche Schnittansicht der Schichtbauvorrichtung gemäß einer weiteren Ausführungsform;
• 5 eine schematische Aufsicht einer Variante der in 4 gezeigten Schichtbauvorrichtung,
• 6 eine schematische Perspektivansicht, in Teilen Schnittansicht, der Schichtbauvorrichtung gemäß einem weiteren Ausführungsbeispiel; und
• 7 eine schematische, teilweise im Schnitt dargestellte Ansicht der Schichtbauvorrichtung gemäß dem Stand der Technik zur additiven Fertigung von Fertigungsprodukten;

Further features of the invention result from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respectively specified combination, but also in other combinations, without the scope of the invention leave. Embodiments of the invention are thus also to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, but can be derived from the explanations explained and can be generated by separate combinations of features. Versions and combinations of features are also to be regarded as disclosed, which therefore do not have all the features of an originally formulated independent claim. In addition, versions and combinations of features, in particular those explained above, are to be regarded as disclosed which go beyond or differ from the combinations of features set out in the references of the claims. It shows:

• 1 a schematic and partially transparent perspective view of a layer construction device according to the invention according to a first embodiment;
• 2 a schematic perspective view of an introduction device and a heating device which are arranged on a support arm;
• 3 a schematic perspective view of the introduction device and flow guide device, which are arranged together on the support arm;
• 4 is a schematic side sectional view of the layer construction device according to another embodiment;
• 5 a schematic supervision of a variant of the in 4 layer construction device shown,
• 6 is a schematic perspective view, partly in section, of the layer construction device according to a further embodiment; and
• 7 a schematic, partly in section view of the layer construction device according to the prior art for additive manufacturing of manufacturing products;

One in 7 schematically and partially shown in section layer construction device 10 is exemplarily designed as a selective laser sintering or laser melting device according to the prior art and is explained below. For building an object or component 40 it contains a process chamber 20th with a chamber wall 42 , In the process chamber 20th is an open construction container 44 with a wall 46 arranged. Through the top opening of the building container 44 is a working level 48 defined, the area of the working plane lying within the opening 48 that is used to build the object 40 can be used as construction site I referred to as. In the container 44 is one in a vertical direction e.g. movable carrier 50 arranged on which a base plate 52 attached to the building container 44 closes down and thus forms its bottom. The base plate 52 can be one separate from the carrier 50 formed plate, which on the carrier 50 is attached, or it can be integral with the carrier 50 be educated. Depending on the powder and process used, it can be on the base plate 52 another build platform 54 be attached to the object 40 is built up. The object 40 but can also on the base plate 52 be built yourself, which then as a construction platform 54 serves. In 7 is that in the building container 44 on the build platform 54 object to be formed 40 below the working level 48 shown in an intermediate state with several solidified layers, surrounded by material that has remained unconsolidated 56 that serves as construction material. The laser sintering device 10 also contains a storage container 58 for the powdery material that can be solidified by electromagnetic radiation 56 and a coater movable in a horizontal direction Y 60 to apply the material 56 on the construction site I , The reservoir 58 can alternatively also below the level of the construction site I be arranged (not shown). From this the material can 56 e.g. , B. by a vertically movable in the z-direction metering die the coater 60 be fed. The laser sintering device 10 also includes an exposure device 64 with a laser 66 which is a laser beam 68 generated as an energy beam via a deflection device 70 deflected and by a focusing device 72 via a coupling window 22 that is at the top of the process chamber 20th in the wall 42 is attached to the working level 48 is focused.

The stratification device also contains 10 a control unit 74 , about which the individual components of the device 10 can be controlled in a coordinated manner to carry out the construction process. The control unit 74 can contain a CPU, the operation of which is controlled by a computer program (software). The computer program can be stored separately from the device on a storage medium, from which it enters the device, in particular the control unit 74 can be loaded. In operation, the carrier is first used to apply a layer of powder 50 lowered by a height that corresponds to the desired layer thickness. By moving the coater 60 over the working level 48 then becomes a layer of the powdery material 56 upset. The coater pushes for safety 60 a slightly larger amount of material 56 ahead of itself than is required to build up the layer. The planned excess of material 56 the coater pushes 60 in an overflow container 62 , On both sides of the building container 44 is an overflow tank 62 arranged.

The application of the powdery material 56 takes place at least over the entire cross section of the object to be produced 40 , preferably over the entire construction site I , i.e. the area of the working level 48 caused by vertical movement of the carrier 100 can be lowered. Then the cross section of the object to be manufactured 40 from the laser beam 68 scanned with a radiation exposure area (not shown), which schematically shows an intersection of the energy beam with the working plane 48 represents. This turns the powdered material 56 solidified in places corresponding to the cross section of the object to be manufactured 40 correspond. These steps are repeated until the object 40 is completed and the building container 44 can be removed. To produce a preferably laminar Process gas flow in the process chamber 20th contains the laser sintering device 10 also a gas supply channel 34 " , a gas inlet nozzle 34 ' , a gas outlet opening 30 ' and a gas discharge duct 30 " , The process gas flow moves horizontally across the construction site I away. A flow direction of the process gas stream runs in 7 in the same spatial direction as the coating direction Y, ie parallel to it. The gas supply channel 34 " who have favourited Gas Inlet Nozzle 34 ' , the gas outlet 30 ' and the gas discharge duct 30 " can also be rotated by 90 ° in or around the process chamber 20th be arranged so that the (horizontal) coating direction Y (rotated accordingly by 90 °) is essentially perpendicular to the (horizontal) flow direction of the process gas stream. The control unit can also supply and remove gas 74 be controlled (not shown). That from the process chamber 20th Aspirated gas can be supplied to a filter device (not shown) and the filtered gas can be supplied via the gas supply channel 34 " the process chamber again 20th are supplied, whereby a recirculation system with a closed gas circuit is formed. Instead of just a gas inlet nozzle 34 ' and a gas outlet opening 30 ' A plurality of nozzles or openings can also be provided in each case.

1 shows a schematic and partially transparent perspective view of a layer construction device according to the invention 10 , The general structure and the general functioning of the layer construction device 10 are from the description of the in 7 shown example are known, but are varied in some aspects in the present case. 1 is summarized below with 2 and 3 are explained, whereby 2 is a schematic perspective view of an introduction device 14 and a heater 12 working on a common support arm 28a are arranged shows. 3 shows a schematic perspective view of a flow guide 16 with their discharge device 14 together on a support arm 28a a carrying device 28 the stratification device 10 are arranged. The stratification device 10 , which in the present case is also exemplarily designed as a selective laser sintering and / or laser melting device, is used for additive manufacturing of the component 40 or at least a component area of this component 40 through an additive layer construction process. With the component 40 or component area can be, for example, a component 40 of an aircraft engine or another turbomachine, where there are basically no restrictions on the type of component and other component types can also be produced in the manner described below.

The stratification device 10 includes a housing 18th which is a process chamber 20th limited. On the top of the case 18th there is a laser transparent window 22 , through which one or more laser beams for selectively solidifying a powder layer 24 in the housing 18th can occur. The process chamber usually has 20th a relatively large interior height, which is primarily due to the requirements of the laser optics unit. A laser beam coming from a central location above the construction site I positioned optics emerges, hits the edge or eccentric areas of the construction and joining zone of the construction site all the more steeply I on, the greater the distance between the level of the construction site I and is an exit point from the assigned optics. A steeper angle of incidence of the laser beam generally standardizes the imaging properties, reduces the need for correction and thus promotes component precision. A large volume of the process chamber 20th is disadvantageous when it comes to keeping an atmosphere of the process chamber clean 20th and the elements it contains goes. In principle, therefore, a protective gas device (not shown) can be provided, by means of which, for example, through the rear of the housing 18th Shielding gas or process gas such as argon through a shielding gas opening 34 into the process chamber 20th can be directed to a defined gas atmosphere in the process chamber 20th to accomplish. However, for economic reasons, only a comparatively small volume flow of process gas is generally supplied.

The powder layer 24 , which is also referred to as a powder bed, is passed over the coater with the aid of a powder feed (not shown for reasons of clarity) 60 on the construction site I applied that in the operation of the layer construction device 10 above the movable construction platform 54 (not shown). The powder layer 24 is fused and / or sintered in layers and / or sintered in this build-up and joining zone by selective exposure to one or more laser beams, whereby the component 40 or the component area is built up in layers according to a predetermined radiation strategy.

A particularly reliable additive manufacturing of component layers of a component with high quality is made possible by the fact that the layer construction device 10 the introduction device already mentioned 14 has, by means of which, alternatively or in addition to the "global" process gas flow through the process chamber 20th through the protective gas opening 34 a “local” protective gas stream, for example a gas stream essentially formed from argon, over the powder layer 24 can be generated within which the construction site I lies. The discharge device 14 is in the exemplary embodiment shown here above the powder layer and relative to the powder layer 24 in the x- / y-plane, that is translational in two mutually perpendicular spatial directions movable. For this purpose, it comprises an outlet opening 14a as an outlet opening through which the protective gas flow essentially parallel to the powder layer 24 or to the level of the construction site I directed exit. The flow rate or the volume flow of protective gas can be varied as required. For example, a protective gas flow can be set in the range between 0.1 l / min and 20 l / min, for example 1 l / min, 5 l / min, 10 l / min or more. Via a flexible channel 36 the protective gas is fed in via the outlet opening 14a the discharge device arranged at the end region of the channel 14 locally in the process chamber 20th is directed. This local blowing across the canal 36 can basically be made from the same shielding gas reservoir as the global shielding gas supply or from a separate shielding gas reservoir with parameters that can be set independently of the global shielding gas supply (speed, volume flow, shielding gas composition, pressure difference to the environment, etc.). In relation to the volume of the process chamber 20th This makes it possible to remove contaminants from the atmosphere in a small-scale and targeted manner and to create a locally improved protective gas atmosphere directly above the process site that is currently being solidified.

The discharge device 14 is a flow control device 16 for guiding the protective gas flow over the powder layer 24 assigned. The flow control device 16 generally forms a flow channel with the smallest possible connection to the rest of the process chamber 20th and thus effectively prevents spreading at the radiation site ( L , in 1 to 3 not shown) resulting impurities in the space of the process chamber 20th , Instead, the resulting impurities can be removed in a targeted manner. The flow control device 16 for this purpose comprises two guide surface segments in the exemplary embodiment shown 16a . 16b , which act as longitudinal guide surfaces and form a flow channel that is open at the top and bottom (z direction), so that a (high) energy or laser beam 68 unhindered from above onto the powder layer 24 can be directed. The guide surface segments 16a . 16b have a length that is at least substantially the length of a construction site side S equivalent. In other words, the guide surface segments extend 16a . 16b over the entire site S , so that in every possible x position of the energy beam there is a local protective gas flow for removing contaminants via the powder layer 24 can be performed. Furthermore, the guide surface segments 16a . 16b at a distance ( e.g. Direction) between 1 cm and 10 cm, for example at a distance of 1 cm, 2 cm, 3 cm, 4 cm, 5 cm or more, from the powder layer 24 arranged. It can be seen that the outlet opening 14a the introduction device 14 in the exemplary embodiment shown, within the flow channel formed or between end regions of the guide surface segments 16a . 16b is arranged. This overlap ensures that no negative pressure arises, through which z. B. powder could be sucked into the flow channel from behind, and that the inert gas flow cannot escape from the flow channel in an uncontrolled manner.

The flow control device 16 defines an initial direction and a main flow direction marked with two arrows H the local flow of the protective gas just above the x / y plane of the layer construction device 10 , in principle any orientations and curved or curved designs of the flow guide 16 possible are. In general, the flow control device 16 if possible be designed or arranged so that the protective gas flow during operation of the layer construction device 10 does not tear off and is not swirled too much. This comparatively simple construction means that at least the radiation site is used as the working area of an energy beam on the construction site or exposure site with reference to a laser beam 68 as an energy beam reliably kept free from smoke, condensate, splashes and other pollutants and harmful gases and the like by the directed protective gas flow.

The control surface segment 16a is on a support arm in the present example 28a a carrying device 28 arranged. How to get in 2 recognizes are also the heating device 12 and the introduction device 14 via respective support arms 28b . 28c indirectly on the support arm 28a the carrying device 28 held. Alternatively, it can also be provided that the heating device 12 and the introduction device 14 on a common support arm 28b or directly on the support arm 28a are held. The guide surface segments 16a . 16b are in 2 not shown for reasons of clarity. Alternatively, the heater 12 and the introduction device 14 are held and moved via individual or independently movable support arms, robot arms or the like. The heater 12 is in turn presently designed as an inductive heater and comprises at least one induction coil 12a , Alternatively, two or more induction coils, for example a cross-coil arrangement, can also be provided. The discharge device 14 can also directly or indirectly on the support arm 28b the heater 12 be set so that the heater 12 , the injector 14 and the flow guide 16 about the carrying device 28 together relative to the powder layer 24 can be moved. Alternatively, the carrying device 28 for example a robot arm or the like for positioning the heating device 12 , the discharge device 14 and / or the Flow control device 16 include. In a further embodiment it can be provided that the induction coil 12a Holding elements (not shown) by means of which the flow guide device 16 or the guide surface segments 16a . 16b and / or the introduction device 14 on the induction coil 12a being held. For example, the guide surface segments 16a . 16b and / or the introduction device 14 via a clip connection on the heating device 12 be held, which allows a particularly quick and easy assembly and disassembly.

The support arm 28a can along the powder layer 24 can be moved translationally in the y direction, while the support arm, which is U-shaped in the present case 28b in the x-direction along the support arm 28a can be moved to the induction coil 12a to position and certain areas of the powder layer 24 to heat to a predetermined temperature. The laser beam or beams are then usually directed in the z direction under the induction coil 12a lying, pre-tempered area of the powder layer 24 directed to selectively solidify it. One recognizes in particular in 2 that the exhaust port 14a in the z-direction approximately at the level of the induction coil 12a or just above the induction coil 12a is arranged so that the protective gas flow in particular the area of the induction coil which is particularly relevant for the component quality 12a , in which the powder solidifies, keeps it free of impurities.

This comparatively small and slowly movable effective exposure area, namely an at least approximately rectangular field in this exemplary embodiment, the area of which essentially lies on the inner circumference of the induction coil arranged above it 12a is limited, the invention takes advantage of advantage. A width of the through the flow guide 16 or the guide surface segments 16a . 16b The flow channel formed essentially corresponds to the width of the induction coil 12a , while the length of the flow channel is essentially the length of the construction site side S corresponds or possibly goes beyond.

The the induction coil 12a flanking guide surface segments 16a . 16b and the flow channel formed thereby extend in the exemplary embodiment shown in the same direction as a global flow over the construction site, since the flow channel or the protective gas flow delimited by it extends along the entire construction site I always in an inlet opening as an inlet opening in the present example along the entire assembly and joining zone I extending gas outlet device 30th flows. The gas outlet device 30th also serves to extract or discharge the global gas through the shielding gas opening 34 into the process chamber 20th introduced protective gas flow. In other words, there is a local injection and a local (and global) suction or discharge of protective gas at opposite ends of the through the flow guide 16 formed flow channel. The inlet opening of the gas outlet device 30th Alternatively, e.g. B. movable in a horizontal slot and provided with a guide rail outlet, so that local injection, flow channel and local suction coordinated, that is moved in the same direction and speed. In this way, an optimal flow profile can be maintained permanently. In addition, practically no disruptive influences from the outside are possible, which means that dirt is removed very effectively from the process chamber 20th is achievable. Furthermore, it can basically be provided that the gas outlet device 30th one or more over the entire length of the assembly and joining zone I extending inlet opening (s) through which suction or discharge is carried out during the entire layer construction process. A movement of the flow guide 16 and thus the flow channel is essentially limited by the extent of the construction site I or the assembly and joining zone. The gas outlet device 30th accordingly preferably has an extension of at least the side length of the rectangular construction area or the assembly and joining zone I in the y direction. Alternatively, it can be provided that an inlet opening of the gas outlet device 30th together with the heater 12 , the discharge device 14 and / or the flow control device 16 along the assembly and joining zone I (e.g. in the y direction), so that the outlet opening 14a the introduction device 14 always on the inlet opening of the gas outlet device 30th is directed and the protective gas flow is at least essentially free of deflection and thus has a particularly low level of swirling over the powder layer 24 is carried out while adjacent and currently unprocessed areas of the powder layer 24 not be vented. For this purpose, the gas outlet device 30th for example, comprise a plurality of openable and closable flaps, flow guide elements or the like, which are dependent on a relative position of the introduction device 14 if necessary, be opened or closed or adjusted. It is also possible that the gas outlet device 30th comprises a type of blind which selectively releases an inlet opening which is dependent on the position of the introduction device 14 along the gas outlet 30th can be moved. The control or regulation of the individual components of the layer construction device 10 can for example take place via a control and / or regulating device (not shown) which executes a corresponding program code. The program code can for this purpose by means of a storage medium provided and processed by a processor of the control and / or regulating device.

How to get in particular 1 and 3 sees, form the longitudinal guide surface segments 16a . 16b a kind of "guide trough" that extends in the z direction from a height just above the construction site or the powder layer 24 to a height just above the outlet opening 14a the local discharge device 14 extend. For example, the guide surface segments 16a . 16b or their highest point P _h (see 4 ) related to the powder layer 24 in the z direction 1 cm, 2 cm, 5 cm or higher via the outlet opening 14a extend. In addition to advantageous flow guidance of the protective gas, this also enables a relatively flat angle of incidence of a solidifying energy beam (laser / electron beam). Optionally, the guide surface segments 16a . 16b only partially closed at the side or designed openwork. So that when moving the induction coil 12a and the flow guide 16 less gas volume in the process chamber in the y direction 20th emotional. This can cause adverse turbulence, which could otherwise lead to powder blowing on the construction site I can lead, reduce. This beneficial effect can be further enhanced if the guide surface segments are arranged upright or perpendicular (ie in the z direction) 16a . 16b have a height that does not go beyond what is absolutely necessary for flow guidance in the x direction. According to a further embodiment variant, an area of the guide surface segments 16a . 16b , which is in operation in the z direction above the outlet opening 14a the introduction device 14 or above the inlet opening of the gas outlet device 30th lies at a flatter angle to the construction site I be arranged as its underlying area. In other words, the guide surface segments 16a . 16b be angled or curved in profile, being in one of the construction site I opposite direction (ie in the z direction to the window 22 hin) widens a cross section of the flow channel. This constructive solution can be particularly advantageous when using an optional ceiling inflow of process gas, since the resulting funnel effect directs or possibly bundles gas flowing in from above into the guide trough or the flow channel, without disturbing the local flow in the flow channel.

With the described local flow through the construction site I the flow area is locally changeable. To keep the process zone and the impact surface of an energy beam as effective as possible L and for the fastest possible removal of impurities in the gas atmosphere through the guide surface segments 16a . 16b the flow control device 16 formed flow channel for guiding the gas inflow from the introduction device 14 together with the flow target area or a process point at which the powder bed 24 is selectively solidified or is to be moved. The only locally acting, from the outlet opening 14a conducted gas flow and that through the flow guide 16 Flow channels formed can be moved jointly by a single drive or separately by two drives, the two drives being able to be moved mechanically completely or to a limited extent independently of one another. This generally represents a separate aspect of the invention, which in particular does not relate to a specific main flow direction H of the protective gas flow is limited. For example, as in 1 shown a first bracket 28a be movable in a first spatial direction (y as an example here) and a second support arm 28b on the one hand on the first support arm 28a be carried along, on the other hand independent of the first support arm 28a be movable or movable in a second spatial direction (x here as an example). Alternatively, however, are combinations or alternative variants of the translational and / or rotational mobility of the individual support arms 28a . 28b possible. For example, the first arm 28a in exactly one first spatial direction ( y Direction) and the second support arm 28b in the first spatial direction ( y Direction) and in a second spatial direction ( x Direction), the second spatial direction ( x Direction) preferably perpendicular to the first spatial direction ( y Direction). Alternatively or additionally, at least one support arm can be used 28a . 28b within a parallel above the construction field I lying plane can be moved. Every support arm 28a . 28b can generally be a separate drive means of the support device 28 be assigned to move. Alternatively, it can be provided that at least two support arms 28a . 28b by means of a common drive means of the carrying device 28 are movable.

In general, the mobility of the heating device 12 and / or the introduction device 14 and / or the flow control device 16 e.g. , B. in a plane parallel to the construction site I and optionally also take place in the z direction. For example, at least one robot arm (not shown) can be used, which allows free translational and / or rotational mobility in the xy plane and, if appropriate, mobility in the z direction. However, instead of a robot arm there are also alternative carrying devices 28 conceivable.

A drive of the heating device that is often required anyway is preferred 12 synergetic also for the drive of the flow control device 16 and / or the introduction device 14 used. This lends itself to a heating area of the heater 12 and a flow target area of the flow guide 16 and / or the Discharge device 14 can form an intersection or at least adjoin one another, wherein a vertical distance is as small as possible, for example can go to zero. A position or movement of the heater 12 and the heating area generated by it thus determines a position or movement of the flow guide device 16 and / or the introduction device 14 defined flow target area. The position or movement of the heating device is preferably controlled or regulated 12 and / or the flow control device 16 and / or the introduction device 14 such that the flow target area and the heating area form an intersection as large as possible in an orthogonal projection onto the level of the construction field, particularly preferably are essentially identical.

For example, as a heater 12 a so-called "cross-coil" is used, which comprises two inductors that can be moved relative to one another in order to be able to overlay the individual induction fields, requires the introduction device 14 a separate drive or support arm for the local gas inlet or must at least be movable in such a way that it overlaps the area of the two inductors, that is to say the most intensive heating area of the heating device 12 , moves or is movable.

In a further aspect of the invention, which is independent of the other aspects of the invention, the heating device 12 , such as in 5 or 6 shown, a larger inductor or a large induction coil 12a as well as a smaller inductor or a small induction coil 12b on, with the small induction coil 12b - preferably exclusively - within the large induction coil 12a or above the projection surface of the large induction coil 12a on the construction site I is movable or movable. With this configuration of the heating device 12 it can then be provided that the introduction device 14 and / or the flow control device 16 on the induction coils 12a . 12b or in each case on an induction coil 12a . 12b or together on the respective support arm 28a . 28b are attached or at least together with the respectively assigned induction coil 12a . 12b are movable. A process with the induction coils 12a . 12b advantageously fulfills the above-defined goals of the guided flow without restriction depending on the heating area.

Another independent inventive concept lies in coupling the mobility of the flow guide device 16 and / or the introduction device 14 to a selected operating mode of the flow and / or the heating. This can be done, for example, with the aid of a correspondingly designed control device or control unit 74 the stratification device 10 be controlled or regulated. For example, a first, “active” operating position can be provided, in which the local gas inflow and the conduction of the local gas flow take place, as for example in FIG 1 shown. This operating position of the heater 12 and the flow control device 16 and / or the introduction device 14 above the construction site I is suitable for heating or flow and can provide mobility in all degrees of freedom or restricted to degrees of freedom that are appropriate for the respective application. In a second, "inactive" operating position, on the other hand, there is no local gas inflow or no conduction of the local gas flow. This operating position preferably includes moving the flow guide device 16 and / or the introduction device 14 in an area outside the traversing motion of the coater 60 in order not to hinder the application of a new layer of powder. For example, a method of the heating device can be used 12 and / or the flow control device 16 and / or the introduction device 14 in a lateral parking position and / or moving or pivoting upwards (z-direction) into the free space of the process chamber 20th be provided. The "inactive" operating position can e.g. B. also during setup, cleaning, flooding, etc. of the layer construction device 10 or be selected in non-process times. This control or regulation of the operating positions of the heating device 12 and / or the flow control device 16 and / or the introduction device 14 generally represents its own aspect of the invention, which can be implemented independently of the other aspects of the invention.

4 shows a schematic side sectional view of the layer construction device 10 according to a further exemplary embodiment and is summarized below with 5 are explained. 5 shows a schematic plan view of a variant of the layer construction device 10 , The basic structure of the layer construction device 10 corresponds to that of in 1 shown embodiment. In contrast to this embodiment, the flow guide device 16 In the present case, it is designed to be telescopic and comprises - in number and arrangement as an example - three guide surface segments that can be displaced in the X direction 16a-c , It can be seen that the guide surface segments 16a-c for this purpose via individual support arms 28c - 28e on the first arm 28a stored and depending on the x-position of the introduction device 14 relative to the construction site I are movable. In 4 you can also see that the main flow direction H from the outlet opening 14a flowing protective gas or process gas flow is not exactly parallel to the powder layer 24 is aligned, but at a flat angle of about 20 ° to the level of the construction site I , that means lightly on the powder layer 24 directed out of the outlet opening 14a of the channel 36 or his Discharge device 14 exit. Due to the comparatively large distance from the outlet opening 14a to the gas outlet device 30th , through which the local inert gas flow back out of the process chamber 20th is discharged or suctioned, the inert gas stream expands after leaving the outlet opening 14a increasing and moving upwards, i.e. in the z direction from the powder layer 24 away, distracted. The limits of the expanding protective gas flow are indicated by the reference symbol IV shown. The angle of the main flow direction H towards the powder layer 24 is dependent on the flow rate and / or the distance to the gas outlet device 30th chosen in such a way that the protective gas flow does not essentially pass in the z direction via the gas outlet device 30th expands, but at most up to the upper edge of the suction opening of the gas outlet device 30th extends. You can also see in 4 that the guide surface segments 16a-c are of different sizes, that of the outlet opening 14a closest guide surface segment 16a lowest in the z direction and the most distant guide surface segment 16c is highest in the z direction. This ensures that a highest point P _h the flow control device 16 not just in the z direction above the outlet opening 14a , but also above the maximum expanded protective gas flow ( IV ) lies. You can also see that related to the construction site I a lowest point P _n all control surface segments 16a-c closer to the powder layer 24 is arranged as a lowest point or the lower edge of the outlet opening 14a of the channel 36 , This ensures reliable flow guidance in every operating state.

Unlike in the 4 embodiment shown in the 5 the heater 12 a large induction coil 12a and one inside the large induction coil 12a movable small induction coil 12b includes whose fields for preheating the powder layer 24 can be deliberately superimposed in order to generate particularly high temperatures. In 4 and 5 is the target area L an energy beam, for example a laser beam on the powder layer 24 shown regularly within the large and small induction coils 12a . 12b Construction site I lies. One recognizes in particular in 5 also the importance of the at least in the working area of the laser upwards (ie to the housing ceiling of the process chamber 20th ) and below (ie to the construction site I ) open flow control device 16 , which ensures that the laser beam 68 unhindered through the window 22 in the process chamber ceiling on the tempered powder layer 24 can be directed to selectively solidify.

6 shows a schematic perspective view, partially sectional view, of the layer construction device 10 according to a further embodiment. In contrast to the previous example, the flow guide device comprises 16 three guiding surface segments different in size, shape and arrangement 16a-c , Of which is the control surface segment 16b formed as a horizontal top surface that the flow guide 16 at least partially closes in operation. This can prevent that from the channel 36 and the introduction device 14 into the process chamber 20th guided shielding gas flow expands too much and always reliably in the direction of the gas outlet device 30th is directed. The control surface segment 16b is slidably mounted on a vertical guide in the z direction. A position of the guide surface segment is preferred 16b in the z direction, ie their respective distance from the construction site I , depending on a current distance of the introduction device 14 or the outlet opening 14a from the inlet opening of the gas outlet device 30th (in the x direction). For example, at a short distance from the outlet opening 14a from the inlet opening of the gas outlet device 30th a low position of the guide segment 16b can be selected because the flow cone (in 4 with the reference symbol IV characterized) of the local process gas flow only widens slightly before it reaches the inlet opening of the gas outlet device 30th reached, and thus essentially only along the underside of the guide surface segment 16b flows. In contrast, with a large distance of the outlet opening 14a from the inlet opening of the gas outlet device 30th a high position of the guide surface segment 16b to get voted. The control surface segment 16c is below the discharge device 14 arranged and ensures that the shielding gas flow is limited in some areas downwards and via the small induction coil 12b flows. On the one hand, this causes a whirling up of the powder layer 24 prevents and on the other hand a particularly reliable discharge of in the area of the small induction coil 12b resulting contamination ensured.

The design of the flow control device 16 can be varied as required, the only thing that should be ensured is that the powder layer solidifies to a largely undisturbed extent 24 remains possible. For this purpose, it can be provided in a further embodiment of the invention that the flow guide device 16 consists entirely or partially of a (highly) energy-beam-transparent material, which means that partially or fully closed flow channels can also be realized, through which the energy beam nevertheless solidifies onto the powder layer 24 can be directed.

As a further alternative, the flow guide device 16 be formed in one piece and as a rudiment only in some areas between the Discharge or discharge device 14 and the gas outlet device 30th extend to the relative movement of the small induction coil 12b to the large induction coil 12a a collision of the flow control device 16 with other components in the process chamber 20th to exclude. The discharge device 14 can on a wall of the flow guide 16 be set while the flow guide 16 in turn via the induction coil 12b on the support arm 28 can be fixed. So that the discharge device 14 , the flow guide 16 and the induction coil 12b on the one hand always together relative to the induction coil 12a in the x direction and on the other hand together with the induction coil 12a in the y direction over the powder layer 24 be moved. This embodiment also offers the advantage that at least the exposure point is reliably kept clear by a directed flow of smoke / condensate / splashes etc. and that the initial guiding effect of the flow guiding device 16 is guaranteed on both sides, so that in this case also an orientation of the protective gas flow from the outlet opening 14a to the inlet opening of the gas outlet device 30th he follows.

To avoid undesired heating, the flow guide device 16 generally preferably be made of a non-metallic or non-electrically conductive and temperature-stable material such as polyether ether ketone (PEEK), so that the flow control device 16 on the one hand not inductively heating itself and on the other hand that when the powder layer solidifies 24 resists the resulting temperatures without damage.

In summary, the layer construction device according to the invention enables 10 and in particular the flow guide device according to the invention 16 different degrees of delimitation of a flow channel by one or more guide surface segments 16a-c , The flow control device 16 can only direct the shielding gas flow in one direction. Alternatively, the flow guide device 16 form a type of guide trough, as described above by the two longitudinal guide surface segments 16a . 16b was shown, which is in the z-direction from a height just above the powder bed 24 extend to a height just above an outlet of the local injection (e.g. 1, 2, 3, 4, 5 cm or more above). The flow guiding device preferably extends 16 and thus the guide trough formed by this at least substantially along an induction coil 12a or along an entire site S , This enables a relatively flat angle of incidence of a solidifying energy beam (laser / electron beam). A design that is only partially closed off to the side also has advantages when using an optionally bundled global inert gas inflow, since a funnel effect can be realized that directs the inflowing gas into the guide trough or possibly bundles it slightly. The local inert gas flow in through the flow control device 16 The flow channel formed is not disturbed. In addition, when moving the flow control device 16 less gas volume in the process chamber 20th moves when the upright guide surface segments 16a-c are dimensioned comparatively flat. This also reduces disadvantageous turbulence, which may lead to powder blowing on the construction site I could lead.

Alternatively, the flow guide device 16 in principle, at least in some areas, a tunnel which is closed at the top or in its entirety, with a large-area, preferably all-round delimitation of the flow channel by guide surface segments 16a-c form. The flow control device 16 can have one or more recesses or cutouts or high-energy beam-transparent areas on the top ("window") in this case, so that one or more (high) energy or laser beams can hit the construction site unhindered. In this case, a position of the recess or recess is preferably relative to the position of a small induction coil 12b over the assembly and joining zone I firmly. An extension or geometry of the recess or recess can, however, also be designed to be variable. This enables a clearly defined flow of the protective gas flow, which ensures particularly effective removal of contaminants.

The parameter values specified in the documents for the definition of process and measurement conditions for the characterization of specific properties of the subject matter of the invention are also to be considered within the scope of deviations - for example due to measurement errors, system errors, DIN tolerances and the like - as included in the scope of the invention.

Reference list

10

Layer construction device

12th

Heating device

12a

Induction coil

12b

Induction coil

14

Discharge device

14a

Outlet opening

16

Flow control device

16a

Control surface segment

16b

Control surface segment

16c

Control surface segment

18th

casing

20th

Process chamber

22

Coupling window

24

Powder bed

28

Carrying device

28a

Beam

28b

Beam

28c

Beam

30, 30 ', 30 "

Gas outlet device

34, 34 ', 34 "

Gas supply duct

36

channel

40

component

42

Chamber wall

44

Building container

46

Wall

48

Working level

50

carrier

52

baseplate

54

Construction platform

56

material

58

Storage container

60

Coater

62

Overflow tank

64

Exposure device

66

laser

68

laser beam

70

Deflection device

72

Focusing device

74

Control unit

I.

Construction site

IV

Limits of gas flow expansion

x, y

horizontal direction

e.g.

vertical direction

L

Impact area of an energy beam

S

Construction site side

H

Main flow direction

Ph

Highest point of the flow control device

Pn

Lowest point of the flow control device

Claims (15)

Layer construction device (10) for the additive production of at least one component area of a component (40) by an additive layer construction method, comprising a process chamber (20), within which at least: - a construction field (I) for layer-by-layer construction of the component area from a material (56); - at least one flow guide device (16) which comprises at least one channel (36) with an outlet opening (14a) for introducing a protective gas into the process chamber (20); and - a gas outlet device (30) which is stationary with respect to the construction field (I) for discharging the protective gas from the process chamber (20), characterized in that the flow guide device (16) is designed to operate the outlet opening during operation of the layer construction device (10) (14a) comprising the end region of the channel (36) of the flow guiding device (16) above a level of the construction field (I) and moving it relative to the level of the construction field (I) in such a way that at least a predominant part of the protective gas along one to the level of the construction field (I) at least substantially parallel main flow direction (H) can be conducted locally over a partial area of the construction field (I). Layer construction device (10) after Claim 1 , characterized in that the flow guide device (16) comprises at least one guide surface segment (16a-c) for limiting a spread of the protective gas introduced into the process chamber (20). Layer construction device (10) after Claim 2 , characterized in that the at least one guide surface segment (16a-c) has a longitudinal extent of at least 50%, preferably at least 70% and particularly preferably at least 100% of a construction site side (S) and / or a construction site diameter of the construction site (I) and / or that the at least one guide surface segment (16a-c) and the end region of the channel (36) of the flow guide device (16) comprising the outlet opening (14a) can be moved relative to one another. Layer construction device (10) after Claim 2 or 3 , characterized in that the flow guide device (16) comprises at least two guide surface segments (16a-c) which are arranged opposite one another and / or which have an outlet opening (14a) of the channel (36) of the flow guide device for the protective gas limit the construction site (I) and / or which are arranged to be fixed relative to one another or movable relative to one another. Layer construction device (10) according to one of the Claims 2 to 4 , characterized in that at least one guide surface segment (16a-c) is arranged at an angle between 60 ° and 120 ° to the construction field (I) and / or in relation to the construction field (I) a highest point (P _h ) of at least one guide surface segment (16a-c) in operation of the layer construction device (10) is at a greater distance from the construction field (I) than a highest point of an outlet opening (14a) of the channel (36) of the flow guide device (16) and / or in relation to the construction field (I ) a lowest point (P _n ) of at least one guide surface segment (16a-c) during operation of the layer construction device (10) is closer to the construction field (I) than a lowest point of an outlet opening (14a) of the channel (36) of the flow guide device (16 ). Layer construction device (10) according to one of the Claims 2 to 5 , characterized in that at least one guide surface segment (16b) of the flow guide device (16) forms an upper side in relation to the construction field (I) and / or in that at least one guide surface segment (16c) of the flow guide device (16) relates to an underside in relation to the construction field (I) forms and / or that at least one guide surface segment (16b) of the flow guide device (16) opens a passage opening for an energy beam (68) at least during operation of the layer construction device (10). Layer construction device (10) according to one of the Claims 1 to 6 , characterized in that a position of the flow guide device (16) within the process chamber (20) relative to the construction field (I) is adjustable depending on a position of an impact surface (L) of an energy beam on the construction field (I) and / or that the flow guide device ( 16) can be moved at least substantially simultaneously with the impact surface (L) of the energy beam on the construction site (I) relative to the construction site (I). Layer construction device (10) according to one of the Claims 1 to 7 , characterized in that at least one guide surface segment (16a-c) has a changeable geometry and / or that at least one longitudinal extent of the flow guide device (16) is adjustable. Layer construction device (10) according to one of the Claims 1 to 8th , characterized in that it comprises a further flow guiding device in the area of an upper side of the process chamber (20), by means of which a global protective gas flow with an essentially perpendicular main flow direction with respect to the construction field (I) can be generated. Layer construction device (10) according to one of the Claims 1 to 9 , characterized in that a carrying device (28) is provided, by means of which at least the end region of the channel (36) of the flow guide device (16) comprising the outlet opening (14a) and / or at least one guide surface segment (16a-c) is relative in at least one spatial direction to the construction field (I) within the process chamber (20). Layer construction device (10) after Claim 10 , characterized in that the support device comprises at least two support arms (28a, 28b) which can be moved relative to the construction field, preferably the first support arm (28a) being movable in exactly one first spatial direction and the second support arm (28b) in the first spatial direction and in is movable in a second spatial direction, the second spatial direction being perpendicular to the first spatial direction. Layer construction device (10) according to one of the Claims 1 to 11 , characterized in that it comprises a heating device (12) by means of which the construction site (I) can be tempered at least in some areas. Layer construction device (10) according to one of the Claims 1 to 12 , characterized in that the outlet opening (14a) of the channel (36) and / or at least one inlet opening of the gas outlet device (30) is arranged closer to the construction field (I) than to a process chamber ceiling during operation of the layer construction device (10). Method for operating a layer construction device (10) according to one of the Claims 1 to 13 , in which, before, during and / or after an additive production of at least one component region of a component (40) by means of an additive layer construction method by means of the flow guide device (16), the end region of the channel (36) of the flow guide device (16) above the outlet opening (14a) arranged on the level of the construction site (I) and moved relative to the level of the construction site (I) in such a way that at least a predominant part of the protective gas emerging from the outlet opening (14a) along a main flow direction which is at least substantially parallel to the level of the construction site (I) ( H) is led locally over a partial area of the construction site (I). Storage medium with a program code which is designed to execute a layer construction device (10) according to one of the Claims 1 to 13 to control so that this is a procedure Claim 14 carries out.

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