Device and method for powder bed-based additive manufacturing processes using induction

Abstract

A device for powder bed-based additive manufacturing processes, particularly in zero gravity, comprising: a storage container for receiving a powder, having an outlet opening; a build platform for forming a powder bed; and a build platform carrier for receiving the build platform and moving the build platform, having an inlet opening, wherein a receiving space is formed by the build platform, a part of the build platform carrier, and the inlet opening. The storage container and / or the build platform carrier are movable relative to one another. In a first position, the outlet opening of the storage container and the inlet opening of the build platform carrier are aligned with one another, so that the powder can pass from the storage container into the receiving space.At least one first induction coil is arranged around the storage container, wherein the at least one first induction coil generates a first magnetic field inside the storage container to move the powder in the direction of the build platform.

Description

The present invention relates to an apparatus for powder bed-based additive manufacturing processes and to a method for powder bed-based additive manufacturing processes.Powder bed-based additive manufacturing methods are known from the prior art. In the known methods, for example laser beam melting, a component is shaped additively in layers. For this purpose, a powder layer is applied to a construction platform and selectively melted by means of a laser beam. This process is repeated until the component has been completely formed in layers.For example, those regions of the layer which are within the desired component geometry to be produced, that is to say the cross section of the component is imaged in the corresponding layer, are melted with the aid of a laser beam (or other directed energy sources, such as e.g. electron beams).According to the prior art, the layer application can be carried out in different ways, which have the common feature that initially more powder is provided than is required for the respective layer. This powder is transferred to the construction platform and the part of the powder which exceeds the desired layer thickness is removed transversely to the layer thickness, depending on the method using a type of doctor blade, a rotating roller or the like. The removal process ensures the aim of a homogeneously applied powder layer which is important for achieving good and homogeneous mechanical properties of the later component. In order to achieve constant material properties of the component to be produced, it is important that a uniform layer thickness, packing density and particle size distribution is present in the homogeneous powder layer. Furthermore, the packing density of the particles in the powder bed should be as high as possible.A disadvantage of the prior art is the required participation of the force of gravity. The powder particles are usually applied from a storage container to the construction platform by gravity. In addition, the powder particles are stabilized and compacted on the construction platform by the action of gravity. Thus, the known additive manufacturing methods cannot be used in zero gravity, for example in outer space, or under conditions with only low gravity, for example under microgravity.DE 10 2021 109 900 A1 describes a system for controlling the material application during additive manufacturing using a magnetic field.DE 10 2022 129 977 A1 describes a device for particle-based additive manufacturing of components, wherein the storage container comprises an outlet opening facing the support surface, wherein the construction platform is designed to be movable within the lateral plane for changing the distance of the construction platform from the support surface, and wherein the support device is designed to be movable relative to the storage container within the lateral plane.DE 10 2014 212 176 A1 describes a powder bed-based additive manufacturing method and a system for carrying out the method, wherein the layer to be applied is formed and solidified outside the powder bed and the formed layer is temporarily held on a carrier component and deposited on the powder bed, wherein the layer is held on the carrier component with the aid of magnetic or electrostatic forces.DE 10 2007 029 142 A1 describes a device for applying powder to an application surface comprising a powder container and a voltage source for applying a voltage between powder container and application surface, wherein the powder container consists at least partially of a conductive material.DE 10 2015 201 796 B3 describes a powder application unit for a device for generative production of components having at least one electrical line, wherein the electrical line is flexible and functions as a powder distributor and heating elementDE 10 2023 000 212 A1 describes a method and an apparatus for producing microparticles and microparticles by additive manufacturing, wherein the pulverulent material located in the first powder reservoir is subjected to a constant force in the direction of a substrate at least during the application.Proceeding from the aforementioned disadvantages of the prior art, the object of the present invention is to provide a simplified apparatus for powder-bed-based additive manufacturing processes and a method for powder-bed-based additive manufacturing processes, for applying force to the powder particles for transport and for stabilizing and compacting the powder particles on the construction platform, in particular in zero gravity.According to a first aspect of the present invention, a device for powder bed-based additive manufacturing processes, in particular in zero gravity, is provided, having a storage container for receiving a powder, having an outlet opening, a construction platform for forming a powder bed, and a construction platform carrier for receiving the construction platform and for moving the construction platform, having an inlet opening, wherein a receiving space is formed by the construction platform, a part of the construction platform carrier and the inlet opening, wherein the storage container and / or the construction platform carrier are movable relative to one another, wherein in a first position the outlet opening of the storage container and the inlet opening of the construction platform carrier are aligned with one another, such that the powder can pass from the storage container into the receiving space, wherein at least one first induction coil is arranged around the storage container, wherein a first magnetic field is generated in the interior of the storage container by the at least one first induction coil for moving the powder in the direction of the construction platform. A current is induced in the powder particles, which generates a magnetic field that is opposed to the first magnetic field, so that the powder particles experience a repulsive force due to the opposed magnetic fields. The powder particles in the storage container are thus moved by induction in a preferred direction, so that the device is suitable in particular for use under microgravity or in zerogravity. In this case, the spatial orientation of the device is not relevant.The receiving space in the construction platform carrier is preferably designed in particular for receiving the powder bed. Thus, the receiving space comprises the amount of powder applied to the construction platform. In particular, the volume of the receiving space is not constant, but is changed by the movement of the construction platform in the construction platform carrier, in particular is increased until the component is completely formed.The first position defines in particular the alignment of the outlet opening of the storage container and the inlet opening of the construction platform carrier with respect to one another. In particular, either the storage container can be moved or the construction platform carrier or the storage container and the construction platform carrier.It is advantageous that the device according to the invention enables a direct application of force to the powder particles. Thus, the apparatus can be made compact and simple. In addition, no complex, in particular no movable, components are required. This reduces the susceptibility to errors, avoids vibrations and reduces the installation space required. This is particularly advantageous in exposed environments, with greatly limited maintenance possibilities, such as in space.Preferably, at least one second induction coil is arranged around the construction platform carrier, wherein a third magnetic field is generated in the interior of the construction platform carrier by the at least one second induction coil for stabilizing the powder bed on the construction platform or a fourth magnetic field is generated in the interior of the construction platform carrier for moving the powder in the direction of the inlet opening. The magnetic field in the interior of the construction platform carrier generated by the at least one second induction coil can support the direction of movement of the powder particles from the first magnetic field of the storage container and thus contribute to the application of a powder layer on the construction platform. In addition, the third magnetic field stabilizes and compresses the powder bed on the construction platform without the action of gravity, in order to form a homogeneous powder layer, in order to achieve good and homogeneous mechanical properties of the later component. After the component has been shaped, excess or unmelted powder can preferably be moved out of the receiving space by the fourth magnetic field.Preferably, a second magnetic field is generated in the interior of the storage container by the at least one first induction coil, for moving the powder in the direction of the storage container. The powder particles are thus held in the storage container by the second magnetic field in order to prevent uncontrolled emergence of the powder particles through the outlet opening, in particular if the outlet opening is not closed or the powder particles are not intended to emerge from the storage container. Furthermore, the second magnetic field preferably enables the return of powder particles into the storage container, for example of unmelted powder particles from the receiving space, after complete shaping of the component. Thus, at least for the majority of the powder particles, the removal by means of a suction device is also dispensed with. Rather, the excess powder particles are again located in a storage container for a further production process.Preferably, more than one induction coil, preferably at least 3 induction coils, are arranged around the storage container and / or the construction platform carrier. In this case, the plurality of induction coils are arranged in particular parallel to one another in order to form a constant direction of movement of the powder particles. In addition, the plurality of induction coils may be sequentially driven and activated to generate a travelling magnetic field.The device preferably additionally has a radiation source for the sequential melting of a powder layer on the construction platform. In this case, the powder particles of the powder layer are locally thermally joined on the powder bed. The radiation source can preferably be an element selected from the group consisting of a laser beam, an electron beam, a plasma beam, an electric arc, a focused solar radiation or a directed radiation from any desired light source. Incandescent bulbs or gas discharge lamps can be used in particular as further light sources according to the invention. Preferably, xenon lamps, in particular in combination with digital light processing (DLP), can likewise be used as possibilities for local thermal joining of the powder particles.Preferably, the storage container and the inlet opening of the construction platform carrier can be arranged offset with respect to one another in a second position, such that the powder bed on the construction platform is accessible through the inlet opening of the construction platform carrier for the action of the radiation source.Preferably, the outlet opening of the storage container and the inlet opening of the construction platform carrier are configured geometrically similar or identical, so that the storage container and the construction platform carrier lie on top of one another in the first position, in particular are arranged positively with respect to one another, so that no powder can escape from the storage container in an uncontrolled manner. Alternatively, the storage container and in particular the outlet opening of the storage container can be smaller in cross section than the cross section of the inlet opening of the construction platform carrier.Preferably, in the first and / or second position, the storage containers and / or the construction platform carrier can continue to be moved relative to one another, for example for uniform application of the powder on the construction platform, in particular in the case of an outlet opening of the storage container having a smaller cross section than the cross section of the inlet opening of the construction platform carrier. In particular, it does not have to keep itself in a static state in the first and / or second position. In particular, in the first and / or second position, the storage container and / or the construction platform carrier can be moved continuously relative to one another.The storage container preferably has a removal device, wherein the removal device is configured, during a relative movement of the storage container and / or of the construction platform carrier from the first position into the second position, to form a planar powder layer at the inlet opening of the construction platform carrier, in particular after introduction of the powder into the receiving space from the storage container. In this case, the pulling-off device can be designed as a doctor blade. The planar powder layer can preferably be formed successively locally, in particular at the locations at which the forming of the component is subsequently carried out.The device preferably additionally has at least one electric current source which is connected to the at least one first induction coil and / or the at least one second induction coil. The current source is designed to generate a current flow in the respective induction coils. The first and second induction coils can preferably be connected to the same current source. Alternatively, the first and second induction coils are connected to a separate power source.Preferably, the current source generates a DC pulse for generating a magnetic field through the first and / or second induction coils. The DC pulse generates a current flow in the induction coils, whereby these are activated. A changing magnetic field is generated by the pulse, so that a current is induced in the powder particles.The current source is preferably designed to activate the first induction coils and / or the second induction coils in each case in a phase-shifted manner, such that the first and / or the third magnetic field are designed as a migrating magnetic field in the direction of the construction platform. If a current flow takes place in the induction coils in a manner offset in time, the current induced in the powder particles is directed and the powder particles experience a direction of movement in the direction of the migrating magnetic field. If the activation initially begins with the coil furthest from the construction platform and moves in the direction of the coil closest to the construction platform, the magnetic field migrates towards the construction platform and the powder particles are moved in the direction of the construction platform. In this case, the first and second induction coils can be the same or different phase-shifted. In particular, the first and second induction coils are phase shifted with respect to one another in such a way that a continuous movement of the powder particles from the storage container to the construction platform is ensured.The current source is preferably designed to activate the first induction coils and / or the second induction coils in each case in a phase-shifted manner, such that the second and / or the fourth magnetic field are designed as a migrating magnetic field in the direction of the storage container. If the activation begins first with the coil furthest from the storage container and moves in the direction of the coil closest to the storage container, the magnetic field migrates in the direction of the storage container and the powder particles are moved in the direction of the storage container. In this case, the first and second induction coils can be the same or different phase-shifted. In particular, the first and second induction coils are phase shifted with respect to one another in such a way that a continuous movement of the powder particles from the construction platform to the storage container is ensured.The powder preferably comprises electrically conductive particles, in particular metallic particles. The changing magnetic field induces currents in the electrically conductive powder particles. The repulsive axial electromagnetic force generated between the induction coils and electrically conductive powder particles drives the powder particles.Preferably, the device is arranged in the zero gravity position. The electromagnetic force acting between the induction coils and powder particles generates a movement of the powder particles, so that the device is independent of the action of gravity. Thus, the device is particularly suitable for use under microgravity or in zero gravity.A second aspect of the present invention relates to a method for powder bed-based additive manufacturing processes, in particular in zero gravity, comprising the provision of a powder in a storage container, the provision of a construction platform in a construction platform carrier, the movement to a first position, wherein in the first position the outlet opening of the storage container and the inlet opening of the construction platform carrier are aligned with one another, such that the powder can pass from the storage container onto the construction platform, the application of a powder layer for a component constructed in layers to form a powder bed on the construction platform by generating a first magnetic field in the interior of the storage container, such that the powder is moved through the outlet opening, the movement to a second position, wherein in the second position the storage container and the inlet opening of the construction platform carrier are arranged offset with respect to one another, so that the powder bed on the construction platform is accessible through the inlet opening of the construction platform carrier for the action of the radiation source and the forming of a component layer by the action of a radiation source. The individual method steps can be carried out sequentially or in an overlapping manner. For example, the radiation source can act locally on the powder bed, while the powder layer is applied locally at another location on the construction platform or the like.The method is preferably further developed on the basis of the features of the device described above.Preferably, during the movement to the first position and / or the second position, the powder is held in the storage container by building up a second magnetic field in the interior of the storage container. Thus, the second magnetic field prevents uncontrolled escape of powder from the storage container.Preferably, for forming a powder bed on the construction platform, a third magnetic field is built up in the interior of the construction platform carrier, so that the powder bed is compacted and stabilized on the construction platform. The third magnetic field causes a force in the direction of the construction platform. The third magnetic field is preferably activated during the application of a powder layer of a component constructed in layers, in particular permanently activated during the forming of the complete component.Preferably, after the forming of a component layer, by the action of a radiation source, the steps of building up the magnetic field in the storage container, moving to the first position, applying the powder layer, moving to the second position and forming a component layer are repeated until the component is completely formed.After shaping of the component, excess and unmelted powder is preferably moved back into the storage container by the second magnetic field of the storage container, in particular together with the fourth magnetic field of the construction platform carrier. In order to optionally avoid contamination of the powder in the storage container, a further storage container with corresponding induction coils can preferably also move excess and unmelted powder particles away from the construction platform into the further storage container.Preferably, a first and / or second magnetic field is built up by a current flow in at least one first induction coil. The current flow can be generated by a connected current source and activates the induction coil, so that a magnetic field, in particular a changing magnetic field, is generated.Preferably, a third and / or fourth magnetic field is built up by a current flow in at least one second induction coil. In a preferred embodiment, the current flow can be generated by the same connected current source as the first and the third magnetic field and activates the induction coil so that a magnetic field, in particular a changing magnetic field, is generated.The first, second, third and / or fourth magnetic field is preferably designed as a travelling magnetic field, in particular by an activation of the respective first and / or second induction coils, which activation is phase-shifted with respect to one another. In this case, a travelling magnetic field is generated in each case by the phase-shifted activation of the induction coils. The property of the travelling magnetic field is to give the transmitted pulses a direction. The powder particles then move in the direction of the travelling magnetic field.A change in direction of the travelling magnetic field is preferably effected by reversing the phase-shifted activation of the induction coils. Thus, the powder particles can first be stabilized by the first magnetic field in the form of a migrating magnetic field out of the storage container and / or by the third magnetic field in the form of a migrating magnetic field on the construction platform. If the first and / or second induction coils are activated in the reverse sequence, the powder particles are moved with the magnetic field now moving in the opposite direction, in particular moved back into the storage container.In the following, with reference to the attached figures, exemplary embodiments of the device according to the invention and the method according to the invention are explained.The following are shown: FIG. 1A is a schematic sectional side view of a device in a second position according to an exemplary embodiment of the present invention; FIG. 1B is a schematic sectional side view of the apparatus of FIG. 1A during movement from a second position to a first position; FIG. 1C is a schematic sectional side view of the device according to FIG. 1A in a first position; FIG. 1D is a schematic sectional side view of the apparatus of FIG. 1A during movement from a first position to a second position; FIG. 2 is a schematic diagram of exemplary current pulses of a current source in accordance with the present invention; FIG. 3 is a schematic illustration of a method for additive manufacturing processes according to the present invention.Identical or similar components are identified in the figures by the same reference numerals.Figure 1A shows a preferred embodiment of the present invention in a second position. The device 1 has a storage container 10 for receiving a powder 12, wherein the powder 12 has in particular electrically conductive particles, in particular metallic particles, a construction platform 22 and a construction platform carrier 20 for receiving the construction platform 22. The representation of the powder particles 12 is only schematic and not to scale, in particular also not to scale relative to the further components represented. In addition, the number shown is only illustrative and should not be understood as a concrete indication of the powder properties.FIG. 1B shows the device 1 for powder bed-based additive manufacturing processes additionally having an outlet opening 100 of the storage container and an inlet opening 200 of the construction platform carrier. The construction platform 22 can be moved within the construction platform carrier in the direction 46, in particular for receiving the powder 12 from the storage container 10. The storage container 10 is movable in the direction 42. However, the invention is not limited to the illustrated movement 42 of the storage container 10. In particular, alternatively, the construction platform carrier 20 can also be moved or the construction platform carrier 20 and the storage container 10 can be moved, so that the relative position of the storage container 10 and the construction platform carrier 20 changes in the manner shown in FIG. 1B.FIG. 1C shows the device 1 in a first position, additionally comprising a receiving space 26, in particular for receiving a powder bed 24, wherein the receiving space 26 is formed by the volume occurring between the construction platform 22, the inlet opening 200 and the construction platform carrier 20. In particular, in the first position, the outlet opening 100 of the storage container and the inlet opening 200 of the construction platform carrier are aligned with one another, so that the powder 12 can pass from the storage container 10 into the receiving space 26, wherein a first magnetic field is generated in the interior of the storage container 10 by the first induction coils 30 for moving the powder 12 in the direction of the construction platform 22.FIG. 1D shows the device 1 for powder bed-based additive manufacturing processes, wherein the storage container 10 additionally has a removal device 14, wherein the removal device 14 is configured, upon movement of the storage container 10 in the direction 44 from the first position into the second position, to form a planar powder layer on the powder bed 24 at the inlet opening 200 of the construction platform carrier. However, the invention is not limited to the illustrated movement 44 of the storage container 10. In particular, alternatively, the construction platform carrier 20 can also be moved or the construction platform carrier 20 and the storage container 10 can be moved, so that the relative position of the storage container 10 and the construction platform carrier 20 changes in the manner shown in FIG. 1D and, in particular, a planar powder layer is formed on the powder bed 24 by the extraction device 14.In particular, second induction coils 32 are arranged around the construction platform carrier 20, wherein a third magnetic field is generated by the second induction coils 32 in the interior of the construction platform carrier 20 for stabilizing the powder bed 24 on the construction platform 22 or preferably a fourth magnetic field is generated in the interior of the construction platform carrier 20 for moving the powder 12 in the direction of the inlet opening 200.In the second position according to FIG. 1A, the storage container 10 and the inlet opening 200 of the construction platform carrier are arranged offset with respect to one another, so that the powder bed 24 on the construction platform 22 is accessible through the inlet opening 200 of the construction platform carrier for the action of a radiation source, for the sequential melting of a powder layer on the construction platform 22 for layer-by-layer production of the component.The number of six first induction coils 30 and three second induction coils 32 shown in FIGS. 1A to 1D is merely exemplary. In particular, the number of the induction coils is not limited to the illustrated embodiment. The storage container 10 and the construction platform carrier 20 preferably each have three coils or more coils or fewer coils.The device preferably has at least one electric current source which is connected to the first induction coils 30 and / or the second induction coil 32, wherein the current source generates in particular a direct current pulse for generating a magnetic field by the first and / or second induction coils. Furthermore, the current source is preferably designed to activate the first induction coils 30 and / or the second induction coils 32 in each case in a phase-shifted manner, such that the first and / or the third magnetic field are designed as a migrating magnetic field in the direction of the construction platform 22. Therefore, the device for powder bed-based additive manufacturing processes is particularly suitable for use under microgravity or in zero gravity.With reference to FIG. 2, three phase-shifted DC pulses 401, 402, 403 can be embodied as a rectangular function having a fixed pulse duration 410 and a time interval 411 between the individual DC pulses, for example. For example, with reference to FIG. 1A, the first DC pulse 401 could preferably belong to the uppermost induction coil of the second induction coils 32 of the construction platform carrier 20, the second DC pulse 402 could belong to the central induction coil of the second induction coils 32 of the construction platform carrier 20, and the third DC pulse 403 could belong to the lowermost induction coil of the second induction coils 32 of the construction platform carrier 20, such that a migrating magnetic field is formed in the direction of the construction platform 22. Here, the number is not limited to the three DC pulses shown. Preferably, more than three or less than three direct current pulses can also be formed according to the number of induction coils. The function of the direct current pulses is not limited to a rectangular shape and can be triangular or sinusoidal, for example. In addition, the pulse duration 410 can preferably be adapted to the geometric boundary conditions, in particular the distance of the individual induction coils from one another, and / or the properties of the powder, and in particular does not have to be of the same size for all pulses, such that the individual pulses 401, 402, 403 can each represent different functions. The time interval 411 between the individual pulses is shown by way of example in FIG. 2. It can be of equal or different length in relation to the pulse duration. In particular, the individual pulses can also overlap in time, so that the distance 411 becomes negative. In this case, a negative time interval 411 means that two successive pulses do not run sequentially, but that, for example, the subsequent pulse 402 can already be initiated while the preceding pulse 401 has not yet ended. In principle, the individual pulses can be carried out in a narrow temporal sequence, in particular with a frequency between 20 and 320 Hz. The time interval 420 between the recurring DC pulses 401, 402, 403 can be matched to the time interval between the individual pulses 411 or can deviate therefrom. Thus, the time interval 420 between two consecutive and recurring DC pulses can also be negative, so that the first pulse 401 of the subsequent pass already starts before the last pulse 403 of the previous pass is ended.FIG. 3 shows a further aspect of the present invention in a preferred embodiment of the present invention for a method 50 for powder bed-based additive manufacturing processes, in particular in zero gravity. In method step S 01, a powder 12 is provided in a storage container 10. In this case, in particular in the second position, the powder 12 can be held in the storage container 10 by building up a second magnetic field in the interior of the storage container 10.In method step S 02, a construction platform 22 is provided in a construction platform carrier 20. In this case, in particular the method steps S 01 and S 02 are not restricted to the sequence shown. In particular, the provision S 02 of a construction platform can also take place before the provision S 03 of a powder or simultaneously.In method step S 03, the movement to a first position takes place, wherein in the first position the outlet opening 100 of the storage container and the inlet opening 200 of the construction platform carrier 20 are aligned with one another, so that the powder 12 can pass from the storage container 10 onto the construction platform 22. During the movement to the first position, the powder 12 is held in the storage container 10, in particular by building up a second magnetic field in the interior of the storage container 10.In method step S 04, a powder layer of a component constructed in layers is applied to form a powder bed 24 on the construction platform 22 by generating a first magnetic field in the interior of the storage container 10, such that the powder 12 is moved through the outlet opening 100. Preferably, for forming a powder bed 24 on the construction platform 22, a third magnetic field is built up in the interior of the construction platform carrier 20, so that the powder bed 24 is compacted and stabilized on the construction platform 22. In particular, the third magnetic field can assist the movement of the powder particles through the first magnetic field in the interior of the storage container during the application of the powder layer. In particular, the third magnetic field is active during the duration of method steps S 01-S 06.In method step S 05, a second position is approached, wherein in the second position the storage container 10 and the inlet opening 200 of the construction platform carrier are arranged offset with respect to one another, so that the powder bed 24 on the construction platform 22 is accessible through the inlet opening 200 of the construction platform carrier for the action of the radiation source. During the movement to the second position, the powder 12 is preferably held in the storage container 10 by building up a second magnetic field in the interior of the storage container 10.In method step S 06, a component layer is formed on the construction platform 22, by the action of a radiation source.These method steps, in particular method steps S 03-S 06, are repeated until the component has been completely formed in layers. In this case, the construction platform 22, after forming a component layer, is preferably lowered by the layer thickness of the subsequent layer, such that the subsequent powder layer can be applied. As a result, the receiving space 26 is correspondingly enlarged.After forming a component, excess and unmelted powder 12 can preferably be moved back into the storage container 10 by the second magnetic field of the storage container 10, in particular together with the fourth magnetic field of the construction platform carrier 20.The build-up of the magnetic fields in the method is preferably effected by a current flow in the first and / or second induction coils, wherein the build-up of a first and / or second magnetic field is effected by a current flow in the first induction coils 30 and the build-up of a third and / or fourth magnetic field is effected by a current flow in the second induction coils 32. The first, second, third and / or fourth magnetic fields are preferably designed as a migrating magnetic field, in particular by a phase-shifted activation of the respective first 30 and / or second induction coils 32, wherein a change in direction of the migrating magnetic field is preferably effected by a reversal of the phase-shifted activation of the induction coils. Here, the direction of the traveling magnetic field corresponds to the moving direction of the powder particles.List of reference numbers:1 Device for powder bed-based additive manufacturing processes 10 Storage container 12 Powder 14 Extraction device 20 Construction platform carrier 22 Construction platform 24 Powder bed 26 Receiving space 30 First induction coils 32 Second induction coils 42 Direction of movement of the storage container into a first position 44 Direction of movement of the storage container into a second position 46 Direction of movement of the construction platform 50 Method for powder bed-based additive manufacturing processes 100 Outlet opening of the storage container 200 Inlet opening of the construction platform carrier

Claims

Device (1) for powder bed-based additive manufacturing processes, in particular in zero gravity, comprising: - a storage container (10) for receiving a powder (12), comprising an outlet opening (100); - a construction platform (22) for forming a powder bed (24); and - a construction platform carrier (20) for receiving the construction platform (22) and methods of the construction platform (22), comprising an inlet opening (200); wherein a receiving space (26) is formed by the construction platform (22), a part of the construction platform carrier (20) and the inlet opening (200); wherein the storage container (10) and / or the construction platform carrier (20) are movable relative to one another; wherein in a first position the outlet opening (100) of the storage container and the inlet opening (200) of the construction platform carrier are aligned with each other so that the powder (12) can pass from the storage container (10) into the receiving space (26); wherein at least one first induction coil (30) is arranged around the storage container (10), wherein a first magnetic field is generated in the interior of the storage container (10) by the at least one first induction coil (30) for moving the powder (12) in the direction of the construction platform (22).The device (1) according to claim 1, wherein at least one second induction coil (32) is arranged around the construction platform carrier (20), wherein a third magnetic field is generated in the interior of the construction platform carrier (20) by the at least one second induction coil (32) for stabilizing the powder bed (24) on the construction platform (22) or a fourth magnetic field is generated in the interior of the construction platform carrier (20) for moving the powder (12) in the direction of the inlet opening (200).The device (1) according to any one of the preceding claims, wherein a second magnetic field is generated in the interior of the storage container (10) by the at least one first induction coil (30), for moving the powder (12) in the direction of the storage container (10).The device (1) according to any one of the preceding claims, wherein more than one induction coil, preferably at least 3 induction coils, are arranged around the storage container (10) and / or the construction platform carrier (20).Device (1) according to one of the preceding claims, additionally comprising a radiation source for the sequential melting of a powder layer on the construction platform (22).The device (1) according to any one of the preceding claims, wherein in a second position the storage container (10) and the inlet opening (200) of the construction platform carrier are arranged offset with respect to each other, so that the powder bed (24) on the construction platform (22) is accessible through the inlet opening (200) of the construction platform carrier for the action of the radiation source.The device (1) according to any one of the preceding claims, wherein the storage container (10) has a pull-off device (14), wherein the pull-off device (14) is configured, upon movement of the storage container (10) from the first position into the second position, to form a planar powder layer at the inlet opening (200) of the construction platform carrier.Device (1) according to one of the preceding claims, additionally comprising at least one electric current source which is connected to the at least one first induction coil (30) and / or the at least one second induction coil (32).The device (1) according to claim 8, wherein the current source generates a DC pulse for generating a magnetic field by the first and / or second induction coils.The device (1) according to claim 9, wherein the current source is configured to activate the first induction coils (30) and / or the second induction coils (32) in each case in a phase-shifted manner, such that the first and / or the third magnetic field are configured as a migrating magnetic field in the direction of the construction platform (22).The device (1) according to claim 9, wherein the current source is configured to activate the first induction coils (30) and / or the second induction coils (32) in each case in a phase-shifted manner, such that the second and / or the fourth magnetic field are configured as a migrating magnetic field in the direction of the storage container (10).Device (1) according to one of the preceding claims, wherein the powder (12) comprises electrically conductive particles, in particular metallic particles.Method (50) for powder bed-based additive manufacturing processes, in particular in zero gravity, comprising: - providing a powder (12) in a storage container (10); - providing a construction platform (22) in a construction platform carrier (20); - moving to a first position, wherein in the first position the outlet opening (100) of the storage container and the inlet opening (200) of the construction platform carrier (20) are aligned with one another, such that the powder (12) can pass from the storage container (10) onto the construction platform (22); - applying a powder layer for a component constructed in layers to form a powder bed (24) on the construction platform (22) by generating a first magnetic field in the interior of the storage container (10), such that the powder (12) is moved through the outlet opening (100); - Moving into a second position, wherein in the second position the storage container (10) and the inlet opening (200) of the construction platform carrier are arranged offset relative to one another, so that the powder bed (24) on the construction platform (22) is accessible through the inlet opening (200) of the construction platform carrier for the action of a radiation source; - forming a component layer by the action of the radiation source.The method (50) of claim 13, wherein a second magnetic field is generated inside the reservoir (10) such that the powder (12) is held in the reservoir (10).Method (50) according to claim 13, wherein, in order to form a powder bed (24) on the construction platform (22), a third magnetic field is built up in the interior of the construction platform carrier (20), such that the powder bed (24) is compacted and stabilized on the construction platform (22).Method (50) according to one of Claims 13 to 15, wherein, after shaping of the component, excess and unmelted powder (12) is moved back into the storage container (10) by the second magnetic field of the storage container (10), in particular together with the fourth magnetic field of the construction platform carrier (20).Method (50) according to one of Claims 13 to 16, wherein the establishment of a first and / or second magnetic field takes place by a current flow in at least one first induction coil (30).Method (50) according to one of Claims 13 to 17, wherein a third and / or fourth magnetic field is established by a current flow in at least one second induction coil (32).Method (50) according to one of Claims 13 to 18, wherein the first, second, third and / or fourth magnetic field is designed as a travelling magnetic field, in particular by mutually phase-shifted activation of the respective first (30) and / or second induction coils (32).Method (50) according to one of Claims 13 to 19, wherein a change in the direction of the travelling magnetic field takes place by reversing the phase-shifted activation of the induction coils.

Images