Device for treating metal powder particles for 3D printing

Abstract

Device (10) for treating metal powder particles (12) for 3D printing, comprising a supply unit (14) for receiving metal powder particles (12) to be treated and a treatment unit (16) that can be coupled to the supply unit (14) for user-defined treatment of the supplied metal powder particles (12), characterized in that the treatment unit (16) comprises working surfaces (22) which are designed for mechanical interaction with the metal powder particles (12) to be treated, wherein the respective metal powder particles (12) can be accelerated relative to the working surfaces (22) by at least two different forces acting on them, such that a change in the geometry of the respective metal powder particles (12) to be treated can be effected, wherein two mutually aligned working surfaces (22) are provided, wherein at least one of the two working surfaces (22) is user-defined and movable relative to the other working surface (22).so that a user-defined adjustable gap (28) can be set between them, wherein a suction device (34) of the device (10) is provided at at least one end of the gap (28), so that respective metal powder particles (12), which can be transferred from the supply unit (14) to the treatment unit (16) according to the principle of gravity, can be moved between the two mechanically acting surfaces (22) in the direction of at least one end.

Description

[0001] The invention relates to a device for treating metal powder particles for 3D printing.

[0002] In powder-based manufacturing processes, such as 3D printing, predominantly spherical powder particles are used.

[0003] Spherical powder particles offer the advantage of reliably providing the desired optimal flowability. This desired flowability is beneficial for a stable production process, for example, because it allows successive layers in a 3D printing process to be applied in a uniform and consistent manner. The objects produced in this way consequently exhibit a correspondingly consistent quality, thus preventing defects.

[0004] A pretreatment of manufacturing powder, which mainly consists of polymer, is presented below.

[0005] German patent application DE 10 2018 206 236 A1 discloses a known method for producing a powder for use in an additive manufacturing process for a three-dimensional object, wherein the powder comprises at least one polymer. Furthermore, such a powder, produced using this method, is described in more detail. The method comprises the following steps: First, the step of mechanically treating the powder in a mixer with at least one rotating mixing blade, wherein the powder is heated to a temperature T. B is suspended. T B The temperature is at least 30 °C and below the melting point T. m of the polymer (determined according to DIN EN ISO 11357), if the polymer is a semi-crystalline polymer. Or T B is at least 30 °C and at most 50 °C above the glass transition temperature T gof the polymer (determined according to DIN EN ISO 11357), if the polymer is a melt-amorphous polymer. Compared to a point before the start of treatment, this method can achieve a minimum increase in the bulk density of the powder by 10% and a minimum decrease in the BET surface area of ​​the powder by 10% after treatment.

[0006] EP 3 643 429 A1, CN 113231639 A, CN 212651913 U, CN 212917620 U and CN 111347053 A describe grinding devices.

[0007] Metal powders used in powder-based manufacturing processes require specific conditions to ensure efficient processing. Furthermore, specialized equipment is needed for the separate conditioning of such metal powders, which must be used before the actual processing stage.

[0008] The invention is based on the objective of providing a device by means of which cost-effective and efficient conditioning of metal powder particles for use in a 3D printing process can be ensured.

[0009] According to the invention, a device for treating metal powder particles for 3D printing is provided. Such a device comprises a staging unit for receiving the metal powder particles to be treated and a treatment unit that can be coupled to the staging unit for user-defined treatment of the staging metal powder particles. The treatment unit also includes working surfaces designed for mechanical interaction with the metal powder particles to be treated. The respective metal powder particles can be accelerated relative to the working surfaces by at least two different forces acting upon them, such that a change in the geometry of the respective metal powder particles to be treated can be effected.

[0010] In this way, it is possible to provide a device that ensures cost-effective and efficient conditioning of metal powder particles for use in a 3D printing process.

[0011] The device is designed in a surprisingly simple way to shape previously irregularly shaped metal powder particles into spherical particles. A purely mechanical treatment is used, which is considered sufficient to achieve a result. Due to user-defined settings within the device during the conditioning of the metal powder particles, such as the selection of contact surfaces or the combination of acting forces to generate a desired resultant force, it is also possible to achieve individual conditioning of the particles. With its surprisingly efficient design, the device offers a cost-effective solution for conditioning predominantly irregularly shaped metal powder particles in such a way that a change in geometry, in particular a change in the geometry towards a spherical shape, can be achieved in the respective metal powder particles being treated.

[0012] The use of the presented device is particularly worthwhile because it enables a manufacturing company to purchase more cost-effective, sharply shaped metal powder particles and then condition them as desired with manageable effort using the presented device.

[0013] The active surfaces are designed such that a desired change in particle geometry can be achieved during the mechanical interaction. In the context of the presented device, active surfaces are therefore, in particular, surfaces that induce a mechanical interaction that goes beyond mere contact. This is intended, for example, to provide a grinding property or similar characteristics. In this respect, the intended active surfaces differ technically, due to their described properties, from simple mixing blades, which are designed only for the localized displacement of the mixture. Mixing blades, in particular, are designed to mix the respective mixture without damaging it or significantly altering its shape.

[0014] It is understood that the two opposing forces are not intended to be opposite, as they would otherwise cancel each other out. Rather, the at least two forces are to be arranged in such a way that a suitable resultant force is applied to the respective metal powder particles to provide the described effect as desired. Due to the surprisingly simple combination of two opposing forces, it is possible to achieve a wide variety of user-defined settings, so that the provided particles interact with the working surfaces in a defined manner. Depending on the desired geometric change, for example, in terms of achieving a specific sphericity of the respective particles, the treatment unit can be adjusted for user-defined treatment, so that the respective metal powder particles can be accelerated relative to the working surfaces by at least two opposing forces acting upon them.

[0015] Spherical metal powder particles are particularly advantageous for shaping manufacturing processes, such as any 3D printing process, because they offer higher flowability compared to irregularly shaped particles. Furthermore, the presented device allows for a surprisingly simple and cost-effective way to achieve a desired result in terms of the geometric modification of the particles being treated, thanks to user-defined adjustability.

[0016] In a further preferred embodiment of the invention, a filling device is provided for use with a device according to any one of claims 1 to 7. Such a filling device comprises a mixing container for receiving metal powder particles. The filling device also comprises a coupling unit by means of which the filling device can be coupled to a dispensing unit of the device, wherein the mixing container can be moved about at least one axis of rotation of the mixing container in a user-defined manner by means of the coupling unit, so that at least a partial change in the geometry of the respective metal powder particles to be treated can be effected.

[0017] Metal powder particles placed in the presented filling device can thus be pre-conditioned prior to the conditioning process in the device for treating metal powder particles for 3D printing. As the mixing container moves, the individual metal powder particles are moved and accelerated in various ways, colliding with other particles and at least partially with the inner walls of the mixing container, thereby inducing at least a partial change in the geometry of the respective particles. In this way, the filled, essentially spiky-shaped particles can be treated surprisingly easily, resulting in at least a partial change in the geometry of the respective metal powder particles to be treated.

[0018] The metal powder preconditioned in this way can then be transferred in the device to a desired final state, with the presented filling device already providing a certain preliminary stage to ensure a cost-effective and efficient process.

[0019] Further preferred embodiments of the invention result from the other features mentioned in the dependent claims.

[0020] In a further preferred embodiment of the invention, it is provided that the at least two acting forces are selected from: gravitational force, a suction force provided by a suction device of the apparatus, centrifugal force, user-defined adjustable acceleration force.

[0021] Depending on the arrangement of the supply unit for receiving the metal powder particles to be treated and the treatment unit that can be coupled to the supply unit, various combinations are achievable, including adjustability of intensity and time window. Any combination can be achieved by a person skilled in the art with reasonable effort, and even a short application time in the presented device is sufficient to determine whether a desired geometric change occurs. In this sense, any metal powder can be conditioned in a surprisingly simple manner using the device. For example, a combination of gravity and suction force can be adjusted to achieve a particularly targeted acceleration of the particles towards the treatment surfaces, thus allowing for user-defined adjustment of the desired interaction of the particles with the treatment surfaces.

[0022] In a further preferred embodiment of the invention, it is also provided that the extraction device is arranged at least partially in a collection container of the device designed to collect treated metal powder particles.

[0023] In this way, the metal powder, or rather the individual particles, can not only be accelerated in the desired direction towards the working surfaces, but can also be precisely placed into the collection container designed for this purpose. The treated metal powder is thus quickly and efficiently available in the container for subsequent uses.

[0024] Furthermore, in a further preferred embodiment of the invention, it is provided that two mutually aligned working surfaces are provided, wherein at least one of the two working surfaces is user-defined and movable relative to the other working surface, so that a user-defined adjustable gap can be set between them, wherein a suction device of the device is provided at at least one end of the gap, so that respective metal powder particles, which can be transferred from the supply unit to the treatment unit according to the principle of gravity, can be moved between the two working surfaces that mechanically act upon them in the direction of at least one end.

[0025] When the particles fall into the treatment unit, their falling speed causes them to collide with the existing working surfaces. This collision is precisely controllable, as the particles' trajectories can be adjusted depending on the applied suction force. For example, the gap can be adjusted so that the working surfaces together produce a grinding effect through mechanical interaction with the particles.

[0026] For example, the gap can be adjusted by aligning the effective surfaces essentially horizontally and opposite each other, so that the particles come into at least partial contact with both effective surfaces during their passage through the gap. It is also conceivable that the gap can be adjusted so that the effective surfaces are aligned with each other in such a way that the gap narrows continuously or discontinuously towards at least one end. In each case, a mechanical interaction can be ensured that leads to the desired change in geometry. The superposition of the at least two forces results in the particles being accelerated advantageously and selectively towards their respective effective surfaces, according to the fundamental physical principles, thus achieving the desired mechanical interaction.In the context of the presented device, a gap is, for example, at least partially uniform in its shape. Irregular shapes for the resulting gap are also conceivable, as long as the mechanical interaction can be achieved as desired.

[0027] Furthermore, in a further preferred embodiment of the invention, it is provided that the at least one movable working surface is movable in a substantially circular manner around a center point of this working surface and / or wherein the transfer of respective metal powder particles from the supply unit to the treatment unit can be supported by means of a vibration unit of the supply unit for user-defined provision of an excitation frequency to the supply unit.

[0028] This makes it particularly easy to adjust a grinding effect between the working surfaces. Furthermore, if metal powder enters the gap between the two working surfaces and thus undergoes mechanical interaction with them, the resulting centrifugal forces, depending on the intensity and duration of the rotation, cause the individual particles to be accelerated outwards, ultimately exiting this area between the working surfaces at at least one end of the gap. In other words, the metal powder particles are moved through the device in such a way that the desired geometric change occurs due to the mechanical interaction. Particles exiting the device are therefore predominantly spherical and thus advantageously processable in subsequent 3D printing devices.The superimposed forces, and in particular the centrifugal forces, cause the metal powder particles, or more generally the metal powder, to be continuously conveyed outwards from a substantially central area of ​​the device, where they are subject to mechanical interaction. The applied suction forces can further influence this effect and control it in a user-defined manner. For example, a suction device, at least partially circumferential, is provided for this purpose, which is combined with a suitable collection container. As a result, spherical powder particles can be formed, which can then be used directly, for example, in a 3D printing process. Thus, the powder is transported radially outwards by the centrifugal forces and additionally by suction forces within the device.The vibration unit of the dispensing unit, used to apply a user-defined excitation frequency to the dispensing unit, is designed to be continuously adjustable, allowing for the selection of a suitable excitation frequency depending on the metal powder particles being processed. The vibrations introduced into the dispensing unit, for example at the upper edge of one of its walls, excite the individual metal powder particles, which are then conveyed towards the processing unit by means of a user-defined acceleration force. The vibration unit of the dispensing unit can also be used optionally in other embodiments or can be arranged as a structurally separate unit in conjunction with other configurations in a suitable manner.

[0029] In a further preferred embodiment of the invention, it is also provided that both working surfaces are movable in a circular motion relative to each other working surface around a respective center point of the respective working surface, wherein a respective opposite rotational movement of the working surfaces is provided or a respective rotational movement in the same direction relative to each other working surface is provided and / or wherein a substantially synchronous rotational movement relative to each other working surface is provided or wherein a substantially asynchronous rotational movement relative to each other working surface is provided.

[0030] The aforementioned advantages can thus be achieved even more effectively. It is also conceivable that the respective embodiments mentioned could be combined serially within the device by a user, according to a selectable program. Depending on the desired result or the shape of the filled metal powder, the desired mechanical interactions can be provided. For example, the gap can also be adjusted according to the intended relative motion of the contact surfaces to achieve a desired result.

[0031] Furthermore, in a further preferred embodiment of the invention, it is provided that the at least one movable working surface essentially performs a user-defined eccentric movement.

[0032] In particular, coarser metal particles can thus be mechanically treated with a reasonable expenditure of time to achieve a desired change in geometry. The eccentric movement is designed, for example, to additionally accelerate the respective metal powder particles within the device. Furthermore, the eccentric movement is designed to create a grinding effect of the introduced powder between the working surfaces, thereby achieving the desired change in geometry. It is also conceivable that the device is designed to create a corresponding eccentric movement of the respective working surfaces relative to each other, thus creating a grinding effect of the introduced powder between the working surfaces and thereby achieving the desired change in geometry.

[0033] In a further preferred embodiment of the invention, it is also provided that the supply unit comprises an acceleration unit for user-defined acceleration of the metal powder particles in the direction of the treatment unit, and that the effective surfaces provided on the treatment unit are user-defined and movable relative to an exit direction of the metal powder particles exiting the acceleration unit, so that a change in the geometry of the respective metal powder particles to be treated can be effected during a respective impact of the metal powder particles on at least a partial area of ​​the effective surfaces.By means of the acceleration unit, which can be in the form of a compressed air nozzle or the like, the respective metal powder particles can be accelerated towards the effective surfaces in such a way that a mechanical interaction of the respective particles with the effective surfaces, or at least with a portion thereof, can be effected. Since the effective surfaces also move relative to the direction of exit, an advantageous mechanical interaction occurs such that a change in the geometry of the respective metal powder particles to be treated can be effected during each impact of the metal powder particles on at least a portion of the effective surfaces. The superimposed effects result in, for example, initially spiky metal powder particles subsequently being essentially spherical due to the change in geometry.Depending on the intensity with which the particles are accelerated towards the effective surfaces, and depending on the manner in which the intended movement of the effective surfaces is planned, a user-defined result in the sense of the defined geometry change can be achieved accordingly.

[0034] Finally, in a further preferred embodiment of the invention, it is provided that the treatment unit is arranged above the collection container of the device and that the collection container can be coupled to the supply unit by means of a return unit of the device.

[0035] Particles collected in the collection container can thus be conveyed back to the supply unit as often as necessary by means of the device's return unit, so that the device continues to exert the described effect until the desired result, in the form of the conditioned powder or metal powder particles, is achieved. The collection container is also equipped with a suction device, for example, to further ensure this process is carried out in a controlled manner.

[0036] The presented device enables cost-effective conditioning of metal powder particles. Therefore, the presented device is advantageously used prior to any forming process in which a separately conditioned metal powder is employed.

[0037] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless otherwise specified in individual cases.

[0038] The invention is explained below using exemplary embodiments with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of a device for treating metal powder particles for 3D printing; Fig. 2 a further schematic representation of another device for the treatment of metal powder particles for 3D printing; Fig. 3 a further schematic representation of another device for the treatment of metal powder particles for 3D printing; Fig. 4 another schematic representation of another device for treating metal powder particles for 3D printing and Fig. 5 a schematic representation of a filling device for use with a device according to any one of claims 1 to 9.

[0039] Fig. Figure 1 shows a schematic representation of a device 10 for treating metal powder particles 12 for 3D printing. The metal powder particles 12 comprise, for example, iron, magnesium, titanium, aluminum, or any other metal. A dispensing unit 14, as shown, contains metal powder particles 12, which can be filled, for example, via a resealable opening (not shown in detail). These metal powder particles 12 to be treated have a substantially spiky shape. The dispensing unit 14 is, as shown, substantially funnel-shaped, so that, relative to the plane of the image, metal powder particles 12 moving downwards push further particles 12 downwards according to the principle of gravity.The illustrated dispensing unit 14 can, in an embodiment not shown in detail, be supplemented by a corresponding vibration unit for the user-defined provision of an excitation frequency to the dispensing unit. In this way, the flow of the metal powder particles can be advantageously supported, in addition to the principle of gravity, by means of a suitable excitation frequency (for example, in the form of a corresponding vibration).

[0040] The dispensing unit 14 can be coupled to a treatment unit 16 of the device 10. For clarity, the dispensing unit 14 and the treatment unit 16 are shown separately in this schematic representation. However, in an embodiment not shown in detail, it is conceivable that the dispensing unit 14 is reversibly or permanently connected to the treatment unit 16. The in Fig. The variant shown in Figure 1 allows a certain freedom of movement for the treatment unit 16, whereby the metal powder particles 12 emerging from the supply unit 14 fall downwards into the treatment unit 16 according to the principle of gravity.

[0041] In this illustrated embodiment of the device 10, the treatment unit 16 comprises a first and a second millstone 18, 20, each of which has working surfaces 22.

[0042] The first millstone 18 has a through-opening 24, which can also be referred to as a through-bore, through which metal powder particles 12 emerging according to the principle of gravity fall towards the second millstone 20. The second millstone 20 is in a rotary motion, which is indicated by a first movement arrow 26 in a counterclockwise direction.

[0043] The respective working surfaces 22 of the two grinding stones 18, 20 are aligned with each other so that a user-defined adjustable gap 28 can be set between them. In other words, the treatment unit 16 comprises working surfaces 22, which are designed for mechanical interaction with the metal powder particles 12 to be treated. In the present embodiment, the metal powder particles 12 enter the working surface 22 of the second grinding stone 20, which is rotating, via the through-opening 24. The metal powder particles 12 are accelerated to the right or left, relative to the plane of the image, towards a respective suction device 34 by the centrifugal forces acting upon them, and thus enter the gap 28 between the two grinding stones 18, 20. Depending on the user-defined setting of this gap 28, the resulting mechanical interactions cause a change in the geometry of the metal powder particles 12.At the first and second end regions 30, 32 of the gap 28, respective suction devices 34 of the device 10 are provided, which are arranged on respective collection containers 36 of the device 10. In this highly simplified representation, the respective suction devices 34 of the device 10 are arranged externally on the respective collection containers 36 of the device 10. However, it is conceivable that these respective suction devices 34 are integrated into the respective collection containers 36, with a possible location on the respective side walls and / or in a floor and / or ceiling area of ​​the respective collection containers 36 of the device 10. The illustrated collection containers 36 can also be arranged circumferentially, so that they surround the millstones 18, 20 at the level of the gap 28 as a continuous unit.Accordingly, the respective integrated extraction devices 34 can also be arranged circumferentially. In other words, separate collection containers 36 are conceivable, which, due to their respective integrated extraction devices 34, then influence the direction of the particles 12. A circumferential design has the advantage that all end regions of the gap 28 can be used equally as an outlet region for the processed metal powder particles 12. The grinding stones 18, 20 are designed rotationally symmetrically, and a resulting gap 28, which is also rotationally symmetrical, can have a corresponding number of end regions (including the first and second end regions shown) circumferentially. In this respect, the respective grinding stones 18, 20 can also be described as respective bodies of revolution, whereby the gap 28 formed between them has at least one end region.The total number of end areas corresponds to a circumferential end area of ​​column 28, which is located between the outermost edge areas of millstones 18, 20.

[0044] An applied suction force causes a resultant force, superimposed on the centrifugal forces, to accelerate the respective metal powder particles 12 from the essentially central region of the device 10 to an outer region of the device 10, whereby the respective metal powder particles 12 are subject to a corresponding mechanical interaction with the effective surfaces 22, so that a desired change in geometry can be effected. A second and third arrow 38, 40 indicate the movement sequences of the respective metal powder particles 12 resulting from the resultant force.

[0045] The respective working surfaces 22 of the millstones 18, 20 are produced, for example, by means of a PVD process (PVD: Physical Vapor Deposition) or a CVD process (CVD: Chemical Vapor Deposition). Depending on the desired result, corresponding working surfaces 22 can be predicted. It is also conceivable that the respective working surfaces are provided as separate components that are interchangeable or at least partially interchangeable, so that the device 10 can be easily configured for different purposes.

[0046] It is also conceivable that the active surfaces 22 are pre-heat-treated and thus conditioned for the upcoming grinding task, so that a desired result regarding the change in geometry can be achieved. Active surfaces 22 coated with diamonds or at least partially equipped with diamonds or a comparable material are also conceivable.

[0047] The millstones 18, 20 cause, firstly, a desired change in the geometry of the metal powder particles 12 due to their existing effective surfaces 22. A subordinate effect also occurs due to a mutual deformation of the particles 12 among themselves, since these particles 12, when they are in the gap 28, also mechanically influence each other.

[0048] In that respect, it shows Fig. 1. A device 10 for treating metal powder particles 12 for 3D printing, comprising a supply unit 14 for receiving metal powder particles 12 to be treated and a treatment unit 16 that can be coupled to the supply unit 14 for user-defined treatment of the supplied metal powder particles 12. The treatment unit 16 comprises corresponding working surfaces 22, which are designed for mechanical interaction with the metal powder particles 12 to be treated, wherein the respective metal powder particles 12 can be accelerated relative to the working surfaces 22 by at least two different forces acting on them, such that a change in the geometry of the respective metal powder particles 12 to be treated can be effected.

[0049] The metal powder particles 12 provided at the top in the supply unit 14 are essentially of a spiky shape, and the metal powder particles 12 emerging at the respective end regions 30, 32 are essentially of a spherical shape.

[0050] In this variant of the device 10, the metal powder particles 12 are malleable by being guided in a user-defined manner between two essentially planar, parallel working surfaces 22. For this purpose, the granular powder is placed via a hopper between two planar, parallel working surfaces 22, which move relative to each other. The first grinding stone 18 has a through-hole 24 in its center through which the powder can flow into the working area. Centrifugal forces continuously convey the powder outwards and collect it, for example, by a circumferential suction device 34 in a collection container 36. As a result, spherical powder particles are formed, which can then be used directly. This device 10 thus makes it possible to purchase more cost-effective granular powder and condition it internally.

[0051] Fig. Figure 2 shows a further schematic representation of another device 10 for treating metal powder particles 12 for 3D printing. The metal powder particles 12 comprise, for example, iron, magnesium, titanium, aluminum, or any other metal. A dispensing unit 14, as shown, contains metal powder particles 12, which can be filled, for example, via a resealable opening (not shown in detail). These metal powder particles 12 to be treated have a substantially spiky shape. The dispensing unit 14 is, for example, substantially funnel-shaped, as shown, so that, relative to the plane of the image, metal powder particles 12 moving downwards push further particles 12 downwards according to the principle of gravity.The illustrated dispensing unit 14 can, in an embodiment not shown in detail, be supplemented by a corresponding vibration unit for the user-defined application of an excitation frequency to the dispensing unit. In this way, the flow of the metal powder particles can be advantageously supported, in addition to the principle of gravity, by means of a suitable excitation frequency (for example, in the form of a corresponding vibration). The dispensing unit 14 can be coupled to a treatment unit 16 of the device 10. For the sake of clarity, the dispensing unit 14 and the treatment unit 16 are shown separately in this schematic representation.

[0052] In this illustrated embodiment of the device 10, the treatment unit 16 comprises a first and a second millstone 18, 20, each of which has working surfaces 22.

[0053] In this illustrated embodiment, the second millstone 20 is designed to perform an eccentric movement. For this purpose, a drive unit 42, as shown, is coupled to the second millstone 20 by means of a coupling unit 44, so that a user-defined eccentric movement in the direction of the fourth movement arrow 46 shown can be effected. A gap 28 between the first and second millstones 18, 20 can be adjusted so that the effective surfaces 22 are aligned with each other in such a way that a continuous or discontinuous narrowing of the gap 28 occurs in the direction of the lower end section 48 (relative to the plane of the image). In particular, the intended mechanical interaction of the metal powder particles 12 with the effective surfaces 22 can be effected in this lower end section 48.Below this lower end section 48, a suction device 34 of the device 10 is also provided, which is arranged on a collection container 36 of the device 10. In this highly simplified representation, the suction device 34 of the device 10 is arranged externally on the collection container 36 of the device 10. However, it is conceivable that this suction device 34 is integrated into the collection container 36, with a possible location on the respective side walls and / or in a floor area and / or a ceiling area of ​​the collection container 36 of the device 10.An applied suction force causes a resultant force to be superimposed on the acceleration forces and / or the gravitational force, accelerating the respective metal powder particles 12 from the essentially upper region of the device 10 to a lower region of the device 10, whereby the respective metal powder particles 12 are subject to a corresponding mechanical interaction with the effective surfaces 22, so that a desired change in geometry can be effected.

[0054] In other words, at least one of the two millstones 18, 20 performs an eccentric movement. Between the millstones 18, 20, the particles 12 are ultimately shaped spherically. Gravity guides the particles 12 towards the narrowing gap 28 between the working surfaces 22, or between the millstones 18, 20. As the gap 28 decreases, the particles 12 become increasingly smaller and more spherically shaped. Different gap dimensions also allow for particle size sorting. After the particles 12 exit the gap 28 at the lower end, they are collected by the collection container 36 with its integrated suction device 34.

[0055] Fig. Figure 3 shows a further schematic representation of another device 10 for treating metal powder particles 12 for 3D printing. The metal powder particles 12 comprise, for example, iron, magnesium, titanium, aluminum, or any other metal. A dispensing unit 14, as shown, contains metal powder particles 12, which can be filled, for example, via a resealable opening (not shown in detail). These metal powder particles 12 to be treated have a substantially spiky shape. The dispensing unit 14 is, as shown, substantially funnel-shaped, so that, relative to the plane of the image, metal powder particles 12 moving downwards push further particles 12 downwards according to the principle of gravity.The illustrated dispensing unit 14 can, in an embodiment not shown in detail, be supplemented by a corresponding vibration unit for the user-defined application of an excitation frequency to the dispensing unit. In this way, the flow of the metal powder particles can be advantageously supported, in addition to the principle of gravity, by means of a suitable excitation frequency (for example, in the form of a corresponding vibration). The dispensing unit 14 can be coupled to a treatment unit 16 of the device 10. For the sake of clarity, the dispensing unit 14 and the treatment unit 16 are shown separately in this schematic representation.

[0056] In this illustrated embodiment, the treatment unit 16 is essentially funnel-shaped, with a first millstone 18 located within an inner area 50 of a second millstone 20. Both millstones 18 and 20 have respective working surfaces 22, which are aligned with each other. The two millstones 18 and 20 are dimensioned such that a gap 28 forms between them, which tapers downwards relative to the plane of the image. The first millstone 18 is rotatably mounted within the second millstone 20, enabling a rotary motion. The first and second millstones 18 and 20 can also be referred to as the first and second conical drums.

[0057] This rotating movement of the first grinding stone 18 within the second grinding stone 20 causes the resulting mechanical interactions between the respective metal powder particles 12 and the contact surfaces 22, thus enabling a desired change in the geometry of the respective metal powder particles 12. According to the principle of gravity, the sinking metal powder pushes the already filled metal powder particles 12 into the narrowing gap 28, creating a grinding effect. The metal powder particles 12 then exit the treatment unit 16 with a modified geometry. In this variant, the treated metal powder particles 12 fall into a collection container 36, which is equipped with a suction device 34. In this highly simplified representation, the suction device 34 of the device 10 is arranged externally on the collection container 36 of the device 10.However, it is conceivable that this suction device 34 is integrated into the collection container 36, with the device 10 being located on the respective side walls and / or in a bottom and / or a top area of ​​the collection container 36. An applied suction force causes a resultant force, superimposed on the acceleration forces and / or the gravitational force, to accelerate the respective metal powder particles 12 from the essentially upper area of ​​the device 10 to a lower area of ​​the device 10, whereby the respective metal powder particles 12 are subject to a corresponding mechanical interaction between the effective surfaces 22, so that a desired change in geometry can be effected.

[0058] The respective grinding stones 18, 20 are conically shaped, and the angularly shaped particles 12 are introduced into their gap 28 via a funnel. Conditioning towards spherical particles 12 occurs through a rotational movement of at least one of the grinding stones 18, 20, which in this variant can also be referred to as a drum. The particles become increasingly spherical as they pass through the narrowing gap 28 between the conical drums. Here, the particles move towards the outlet due to gravity. A specific particle size can also be filtered out by adjusting the gap size. After the particles have passed through the outlet, they are collected by the collection container 36 with an integrated suction device 34.

[0059] Fig. Figure 4 shows a further schematic representation of another device 10 for treating metal powder particles 12 for 3D printing. The device 10 is shown with a supply unit 14, which includes an acceleration unit 52. By means of the acceleration unit 52, metal powder particles 12 provided in the supply unit 14 can be accelerated in a user-defined manner towards a treatment unit 16 of the device 10. The acceleration unit 52 is, for example, in the form of a compressed air nozzle. The treatment unit 16 has working surfaces 22, which are provided on a substantially circular disk on one side facing the acceleration unit 52. The treatment unit 16 is designed to rotate about a central axis, with a fifth arrow 54 indicating clockwise movement.The metal powder particles 12 exiting the acceleration unit 52 strike the treatment unit 16 in an impact zone 56 of the effective surfaces 22.

[0060] During the impact of the metal powder particles 12 onto the effective surface 22 in the impact zone 56, the roughly shaped metal powder particles 12 undergo geometric changes due to superimposed processes, resulting in an essentially spherical shape. In other words, roughly shaped particles 12 are accelerated by a user-defined airflow, in the direction of a sixth arrow 58, onto an end face with corresponding effective surfaces 22 of a rotating disc by a treatment unit 16. Depending on the intensity of the airflow and the rotational speed of the disc, corresponding geometric changes in the metal powder particles 12 can be achieved. The impacting particles 12 are set into rotation by the rotating disc and thus assume a spherical shape.The impacting metal powder is then collected by a collection container 36 with an integrated extraction device 34. From the collection container 36, previously treated metal powder particles 12 can be returned to the supply unit 14 via a return unit 60 of the device 10, so that the same metal powder particles 12 can undergo this cycle until a desired change in geometry occurs. In other words, this process can be carried out using the device 10 according to this variant until a desired sphericity of the metal powder particles 12 is achieved. In this way, for example, the recycling of previously used metal powder is possible, with this device 10 then being considered a type of processing plant.

[0061] This also makes an integrated sorting process possible, whereby the metal powder is removed according to the number of passes.

[0062] Therefore, in Fig. Figure 4 shows a device 10 in a particular embodiment, which shows the dispensing unit 14 in conjunction with an associated acceleration unit 52. The acceleration unit 52 is designed to accelerate metal powder particles 12 in the direction of the treatment unit 16 in a user-defined manner. The accelerated metal powder particles 12 are movable in the direction of the treatment unit 16. The working surfaces 22 provided on the treatment unit 16 are movable relative to an exit direction of the metal powder particles 12 exiting the acceleration unit 52 in a user-defined manner, so that a change in the geometry of the respective metal powder particles 12 to be treated can be effected during each impact of the metal powder particles 12 on at least a partial area of ​​the working surfaces 22.The treatment unit 16 is arranged above the collection container 36 of the device 10 and the collection container 36 can be coupled to the supply unit 14 by means of a return unit 60 of the device 10.

[0063] Fig. Figure 5 shows a schematic representation of a filling device 62 for use with a device 10 according to any one of claims 1 to 9. In particular, a mixing container 64 of this filling device 62 is shown. This mixing container 64 is designed to receive metal powder particles 12 (as shown). Specifically, it is provided that brittle metal powder particles 12 can be filled into an inner region 66 of the mixing container 64 via an opening (not shown in detail). The filling device 62 comprises a coupling unit (not shown in detail) by means of which the filling device 62 can be coupled to a dispensing unit of the device 10 (also not shown in detail), wherein the mixing container 64 can be moved about at least one axis of rotation of the mixing container 64 by means of the coupling unit in a user-defined manner, so that at least a partial change in the geometry of the respective metal powder particles 12 to be treated can be effected.In the present case. Fig. Figure 5 shows three possible axes of rotation 68, 70, 72 with their respective corresponding arrows. In this way, it is possible to at least partially shape the particles 12 spherically during each rotation through mutual collision and interaction. Here, the particles 12 are conditioned in the rotating mixing container 64 with a user-defined mixing duration and acceleration. For example, a specific mixing control program is provided. Depending on the desired result, a corresponding mixing control program is then provided. The metal powder preconditioned in this way can then be transferred to the device 10 for further processing. Reference symbol list 10 Device 12 metal powder particles 14 Provisioning unit 16 treatment units 18 first millstone 20 second millstone 22 Effective area 24 Through opening 26 first movement arrow 28 gaps 30 first end range 32 second end area 34 Extraction device 36 collection containers 38 second movement arrow 40 third movement arrow 42 Drive unit 44 coupling unit 46 fourth movement arrow 48 lower end section 50 Indoor area 52 Acceleration unit 54 fifth movement arrow 56 Impact zone 58 sixth movement arrow 60 Return unit 62 Filling device 64 mixing containers 66 Interior 68 first axis of rotation 70 second axis of rotation 72 third axis of rotation

Claims

Device (10) for treating metal powder particles (12) for 3D printing, comprising a supply unit (14) for receiving metal powder particles (12) to be treated and a treatment unit (16) that can be coupled to the supply unit (14) for user-defined treatment of the supplied metal powder particles (12), characterized in that the treatment unit (16) comprises active surfaces (22) which are designed for mechanical interaction with the metal powder particles (12) to be treated, wherein the respective metal powder particles (12) can be accelerated relative to the active surfaces (22) by at least two different forces acting on them, such that a change in the geometry of the respective metal powder particles (12) to be treated can be effected, wherein two mutually aligned active surfaces (22) are provided, wherein at least one of the two active surfaces (22) is user-defined and movable relative to the other active surface (22).so that a user-defined adjustable gap (28) can be set between them, wherein a suction device (34) of the device (10) is provided at at least one end of the gap (28), so that respective metal powder particles (12), which can be transferred from the supply unit (14) to the treatment unit (16) according to the principle of gravity, can be moved between the two mechanically acting surfaces (22) in the direction of at least one end. Device (10) according to claim 1, wherein the extraction device (34) is arranged at least partially in a collection container (36) of the device (10) designed to collect treated metal powder particles (12). Device (10) according to one of the preceding claims, wherein the at least one movable working surface (22) is movable in a substantially circular manner around a center point of this working surface (22) and / or wherein the transfer of respective metal powder particles (12) from the supply unit (14) to the treatment unit (16) can be supported by means of a vibration unit of the supply unit (14) for user-defined provision of an excitation frequency to the supply unit (14). Device (10) according to one of the preceding claims, wherein both working surfaces (22) are movable in a circular motion relative to each other working surface (22) about a respective center point of the respective working surface (22), wherein a respective opposite rotational movement of the working surfaces (22) is provided or a respective rotational movement in the same direction relative to each other working surface (22) is provided and / or wherein a substantially synchronous rotational movement relative to each other working surface (22) is provided or wherein a substantially asynchronous rotational movement relative to each other working surface (22) is provided. Device (10) for treating metal powder particles (12) for 3D printing, comprising a supply unit (14) for receiving metal powder particles (12) to be treated and a treatment unit (16) that can be coupled to the supply unit (14) for user-defined treatment of the supplied metal powder particles (12), characterized in that the treatment unit (16) comprises working surfaces (22) which are designed for mechanical interaction with the metal powder particles (12) to be treated, wherein the respective metal powder particles (12) can be accelerated relative to the working surfaces (22) by at least two different forces acting on them, such that a change in the geometry of the respective metal powder particles (12) to be treated can be effected, wherein the at least one movable working surface (22) essentially performs a user-defined eccentric movement. Device (10) for treating metal powder particles (12) for 3D printing, comprising a supply unit (14) for receiving metal powder particles (12) to be treated and a treatment unit (16) that can be coupled to the supply unit (14) for user-defined treatment of the supplied metal powder particles (12), characterized in that the treatment unit (16) comprises working surfaces (22) which are designed for mechanical interaction with the metal powder particles (12) to be treated, wherein the respective metal powder particles (12) can be accelerated relative to the working surfaces (22) by at least two different forces acting on them, such that a change in the geometry of the respective metal powder particles (12) to be treated can be effected.wherein the delivery unit (14) comprises an acceleration unit (52) for user-defined acceleration of the metal powder particles (12) in the direction of the treatment unit (16) and the working surfaces (22) provided on the treatment unit (16) are user-defined and movable relative to an exit direction of the metal powder particles (12) exiting the acceleration unit (52), so that a change in the geometry of the respective metal powder particles (12) to be treated can be effected during a respective impact of the metal powder particles (12) on at least a partial area of ​​the working surfaces (22). Device (10) according to claim 6, wherein the treatment unit (16) is arranged above the collection container (36) of the device (10) and the collection container (36) can be coupled to the supply unit (14) by means of a return unit (60) of the device (10). Filling device (62) for use with a device (10) according to one of claims 1 to 7 comprising a mixing container (64) for receiving metal powder particles (12), characterized in that the filling device (62) comprises a coupling unit by means of which the filling device (62) can be coupled to a dispensing unit (14) of the device (10), wherein the mixing container (64) can be moved by means of the coupling unit about at least one rotation axis of the mixing container (64) in a user-defined manner, so that at least a partial change in the geometry of the respective metal powder particles (12) to be treated can be effected.

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