Electron beam system and method for additive manufacturing of a workpiece

Abstract

An electron beam system (10) for additive manufacturing of a workpiece (43) comprises an evacuatable process chamber (12) and an electron beam generating device (22) which is designed to direct an electron beam (26) in the process chamber (12) onto different lateral positions of a powder bed (42) of a powdery material (46) to be processed.SOLUTION: In order to increase the throughput, the electron beam system (10) has at least one evacuatable prechamber (14) which is continuously connected in a vacuum-tight manner to the process chamber (12) via an airlock door (16) during the operation of the electron beam system (10). Furthermore, at least one movable receiving device (32) for receiving a powder bed (42) and a transport device (30) are provided, by means of which the at least one receiving device (32) can be transported from the prechamber (14) into the process chamber (12).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electron beam system for additive manufacturing of workpieces, comprising a transport device for moving a receiving device between an evacuable process chamber and an evacuable pre-chamber.

[0002] Furthermore, the present invention relates to a method for manufacturing a workpiece in such an electron beam system. [Background technology]

[0003] Additive manufacturing is characterized by the creation of three-dimensional structures by joining volume elements, particularly layer by layer, in particular by using an energy beam to bond powder material in a powder bed to form three-dimensional structures by selectively melting individual powder particles point by point and layer by layer.

[0004] Solidification of the material can be achieved by sintering or completely melting the powder particles with a laser or electron beam (for simplicity, all degrees of melting / sintering will be referred to simply as "melting" in the following). Processing metal powders by selective electron beam melting (SEBM) allows for the production of complex shaped metal structures while allowing for high speed, precision, and a high degree of automation.

[0005] Melting of materials with electron beams is performed in a vacuum because electron collisions with air molecules can result in excessive energy loss and scattering. Therefore, the process chamber of an electron beam system is typically evacuated and cooled to 100°C before operation. -5 ~10 -2 It is operated at a pressure of 1000 mbar.

[0006] Due to the energy supply from the electron beam and optional additional heating of the powder bed, the material surface reaches temperatures of over 1000°C. Before the finished workpiece can be removed, it must be cooled to a predetermined maximum temperature.

[0007] However, cooling of a workpiece in a vacuum process chamber can take hours to days depending on the material, the nature of the powder bed, and the build volume, because there is very little heat exchange in a vacuum due to the lack of convection, resulting in very slow cooling rates and very long cooling times.

[0008] Injecting air into the process chamber early to reduce the cooling time is disadvantageous for several reasons: the hot surface of the workpiece reacts with the oxygen contained in the air, which can result in uncontrolled changes in the structure of the workpiece, such as oxidation of the metal.

[0009] One way to speed up the cooling process is to introduce a noble gas, such as helium. This allows heat to escape more quickly and avoids reaction with the metal surface. However, noble gases are generally expensive, increasing the cost of the process.

[0010] The vacuum must be released at the latest when the workpiece is removed from the process chamber. The time required to restore the vacuum for the next process, during which the system is unavailable, adds up to a significant amount of unproductive time, calling into question the economic viability of this method.

[0011] Known electron beam systems solve this problem by providing multiple process chambers, however this results in significant additional costs in terms of equipment.

[0012] In other systems, the workpiece is produced in a receiving device that can itself be evacuated and introduced into the process chamber, but this requires adapting the receiving device to the system, which does not allow for flexibility of the system and / or receiving device. Summary of the Invention [Problem to be solved by the invention]

[0013] It is an object of the present invention to provide an electron beam system for additive manufacturing of workpieces that is improved with respect to the above-mentioned exhaust problems, in particular by avoiding long cooling times and thereby reducing non-productive time in the manufacturing process.

[0014] Furthermore, it is an object of the present invention to provide a corresponding manufacturing method for operating this system. [Means for solving the problem]

[0015] According to the invention, the object is an electron beam system for additive manufacturing of workpieces, comprising: a) an evacuable process chamber; b) an electron beam generator disposed at least partially within the process chamber and configured to direct an electron beam at different lateral positions of a powder bed of powder material to be processed; Equipped with c) at least one evacuable pre-chamber continuously connected in a vacuum-tight manner to the process chamber via an airlock door during operation of the electron beam system; d) at least one movable receiving device for receiving the powder bed; e) a transfer device capable of transferring at least one receiving device from the pre-chamber to the process chamber; This is achieved by an electron beam system characterized by having:

[0016] The system according to the invention comprises a pre-chamber in which a movable receiving device together with the powder bed and / or the workpiece can be placed, where the pre-chamber and the process chamber are connected in a vacuum-tight manner via an airlock door so that they can be evacuated separately from each other, and a conveying device allows the receiving device for the powder bed to be moved from one chamber to the other.

[0017] The pre-chamber being continuously connected to the process chamber during operation means, inter alia, that the pre-chamber essentially remains connected to the process chamber, however, the pre-chamber can be removed from the process chamber for maintenance purposes outside of normal system operation.

[0018] This allows for a controlled cooling phase of the workpiece without long system idle times. This is because, while a workpiece is being manufactured in the process chamber, another powder bed can be prepared in another receiving device in the pre-chamber without breaking the vacuum on the process chamber. As a result, while the finished workpiece is being cooled in the pre-chamber after being manufactured, the process chamber can already be loaded with the next receiving device. In contrast, in conventional workpiece processing, it is only known to load and unload the finished workpiece.

[0019] For example, if two pre-chambers are used for one process chamber, the movable receiving device for the powder bed can be transferred to the second pre-chamber after the workpiece is produced, while the next movable receiving device is subsequently or during the transfer from the first pre-chamber to the process chamber.

[0020] Thus, the system according to the present invention allows for parallel manufacturing and cooling, which allows for significant time savings in terms of non-productive time in the additive manufacturing process.

[0021] The movable receiving device preferably has a build vessel designed to receive a powder bed in which a workpiece can be additively manufactured.

[0022] In this case, the build vessels of the two receivers can be of different dimensions. In this way, movable receivers with different installation spaces can be introduced into the electron beam system, allowing the size of the powder bed to be adapted to one or more workpieces, for example, optimizing the use of powder material. In addition to saving time, this creates additional variability in the system and improves economy by reducing powder consumption.

[0023] The movable receiving device preferably comprises a storage container for the powder material.

[0024] The storage container for the powdered raw material is also integrated into the receiving device, allowing workpieces of different materials to be produced sequentially without the need to inflate and evacuate the process chamber. This increases the system's flexibility. It also eliminates the need to replenish the powdered material in the process chamber. Furthermore, the amount of powdered material in the vacuum chamber can be kept small, reducing suction losses.

[0025] The movable receiving device preferably comprises a powder application device, in particular a doctor blade, designed to transfer powder material from a storage container to a build container and form a powder bed there for the additive manufacturing of the respective workpiece.

[0026] Although it is basically possible to leave the doctor blade system in the process chamber, it is advantageous if the doctor blade system is also carried by the movable receiving device, since the doctor blade system may have a complex mechanical structure and is therefore more easily maintained. It is preferred that the entire doctor blade system is carried by the movable receiving device. However, it is also possible that only the powder application element, such as the doctor blade, is carried by the movable receiving device, and the drive actuator of the doctor blade system remains permanently in the process chamber.

[0027] The transfer device is preferably designed to exchange a first movable receiving device, which is initially located in the pre-chamber, with a second movable receiving device, which is located in the process chamber.

[0028] In this context, "exchange" refers to a general placement within the respective chamber, not an exchange to the exact same location. For example, a first receiving device may first be removed from a pre-chamber and transferred next to a second receiving device located in a process chamber. The second receiving device can then be transferred into the pre-chamber. By appropriately deflecting the electron beam, the manufacturing process can be performed both in the original location within the process chamber and at another location on the receiving device.

[0029] By replacing the two movable receiving devices, only one pre-chamber is required as the airlock.

[0030] The transport device preferably has at least two transport tracks along which at least two movable receiving devices can be transported back and forth past each other between the pre-chamber and the process chamber.

[0031] Such a transport device allows two receiving devices to be transported at approximately the same pace, thereby reducing the time required to exchange the movable receiving device. In this case, both transport tracks can communicate not only through a common airlock door, but also through two adjacent airlock doors.

[0032] Preferably, the at least two conveying tracks extend parallel to one another.

[0033] This simplifies the structure of the transport device.

[0034] The pre-chamber and / or the receiving device preferably comprises at least one temperature measuring device.

[0035] As a result, it is possible to monitor, among other things, the cooling process taking place in the pre-chamber, and also to measure the temperatures of the workpiece, the powder bed, and / or other components of the system.

[0036] Preferably, a loading / unloading station is connected to the pre-chamber, by means of which at least one movable receiving device can be transported into or out of the electron beam system.

[0037] For this purpose, the pre-chamber has a separate airlock door through which the receiving device can be transferred into or out of the pre-chamber. In the simplest case, the unloading station consists, for example, of a rail system on which the receiving device can be slid into the pre-chamber.

[0038] The electron beam system preferably comprises a control unit for the transport device.

[0039] Although the transport device can be designed to be operated manually by a user, it is advantageous if the transport device is operated automatically via a control unit and corresponding actuators. This allows for shorter cycle times. In particular, the control unit can adjust the process depending on the measured temperature and control the transport device and / or the airlock door.

[0040] The problem described at the outset is solved in terms of a method, which method is for additively manufacturing a workpiece, comprising: a) providing an electron beam system as described above; b) manufacturing a first workpiece in the first movable receiving device by processing powder material in the powder bed using an electron beam in the process chamber; c) attaching a second movable receiving device to the pre-chamber and then evacuating the pre-chamber; d) transferring the first movable receiving device from the process chamber to the pre-chamber; e) transferring the second movable receiving device from the pre-chamber to the process chamber; f) manufacturing a second workpiece in a second movable receiving device by processing the powder material in the powder bed with an electron beam in the process chamber; g) cooling the first workpiece in the first movable receiving device in the pre-chamber; This is solved by a method comprising:

[0041] In this manufacturing method, a previously manufactured workpiece can be cooled to a specific temperature according to an optimized time temperature profile while another workpiece is being manufactured. The cooling can also be accelerated by metering the ventilation of the pre-chamber. Therefore, workpieces manufactured by this manufacturing method are better cooled according to the temperature profile requirements, and therefore, in terms of quality, these workpieces stand out from workpieces manufactured by other methods.

[0042] Preferably, the following steps are provided:

[0043] The first movable receiving device is removed from the pre-chamber together with the workpiece.

[0044] By removing the entire receiving device rather than just the workpiece, the powder bed or storage container can be easily prepared for the production of the next workpiece.

[0045] Workpieces manufactured by the method according to the invention and by the system according to the invention are applied in particular in the aerospace industry as turbine blades, pump wheels, helicopter transmission mounts, in the automotive industry as turbocharger wheels and wheel spokes, in medical technology as orthopedic implants and prostheses, as heat exchangers and in tool and die manufacturing.

[0046] The powder material may include any electrically conductive material suitable for electron beam processing, and suitable examples include metallic or ceramic materials, particularly titanium, copper, nickel, aluminum, and alloys thereof, such as Ti-6Al-4V, AlSi10Mg, and titanium aluminide (TiAl), which are alloys of titanium with 6% by weight of aluminum and 4% by weight of vanadium.

[0047] Other exemplary materials include nickel-based alloys such as NiCr19NbMo, iron and iron alloys, particularly steels such as tool steel and stainless steel, copper and its alloys, refractory metals, particularly niobium, molybdenum, tungsten, and their alloys, precious metals, particularly gold, magnesium, and their alloys, cobalt-based alloys such as CoCrMo, high-entropy alloys such as AlCoCrFeNi, CoCrFeNiTi, and shape memory alloys.

[0048] The powder material used preferably has an average particle size D50 of 10 μm to 150 μm.

[0049] Another aspect of the present application relates to better maintainability of the system and avoidance of contamination in a system for additive manufacturing of workpieces.

[0050] In beam systems, especially electron beam systems, certain parts of the system come into contact with the powder material used for the manufacturing process, so when switching to a different material for a subsequent build process, there is a risk that the new material will be contaminated with powder residue from the previous process, which could potentially impair the system's functionality.

[0051] Therefore, apart from the airlock solution described above, another objective of the present invention is to create better maintenance possibilities and / or reduce the risk of contamination.

[0052] The problem is a system for additive manufacturing of a workpiece, comprising: a) a process chamber, preferably evacuable; b) a build vessel capable of producing the workpiece; c) a storage container for the powder material; d) a powder application device designed to transfer powder material from a storage container to a powder bed within the build container; e) a beam generator designed to direct an energy beam, in particular an electron beam, in the process chamber to different positions laterally of the powder bed, f) The problem is solved by a system in which the powder coating device can be removed from the process chamber.

[0053] Therefore, according to the invention, the powder application device is designed so that it can be easily removed from the process chamber between two workpieces that are produced one after the other in normal operation, and therefore is not particularly fixed within the process chamber.

[0054] In this context, "removable" means that the component can be removed from the system without structural modifications, tools, etc. For example, a powder application device can be pulled out of a process chamber along a guide device.

[0055] In a preferred embodiment, the doctor blade is fixed onto the receiving device, and the entire receiving device can be completely removed from the process chamber. Preferably, the doctor blade and / or the receiving device can be completely removed from the process chamber and / or system.

[0056] The system preferably includes at least one movable receiving device having a build vessel, a storage vessel, and a powder application device.

[0057] In this way, the main components of the system that come into contact with the powdered raw material are combined into a portable, compact unit, reducing the risk of contaminating the new material with powder residues from the previous process when switching to another material.

[0058] Preferably, at least one movable receiving device is transportable into and out of the process chamber.

[0059] The movable receiving device is a mobile, compact unit that is advantageous in terms of handling when being transferred into or out of the process chamber. For the transfer, a transport device, for example a chain hoist, can be provided, which moves the movable receiving device in the process chamber.

[0060] Preferably, at least one movable receiving device is designed to receive shaped vessels and / or storage vessels having different dimensions, in particular different volumes.

[0061] In this way, the space requirements and material consumption can be precisely adjusted to the manufacturing process and / or workpiece. In this case, the external dimensions of the receiving device remain the same, especially if there are means for cooperation with the transport device. The dimensions of the containers may vary from one receiving device to another. However, the receiving devices are preferably designed in a modular manner so that containers of different sizes can be inserted into a given support frame.

[0062] It is preferable that all components involved in the process be removable from the process chamber.

[0063] In particular, all components of the system that intentionally come into contact with powder material in preparation for and / or during the melting process are considered process-related, such as the movable receiving device with the build vessel and powder storage container, the powder application device, as well as overflow and / or powder residue containers (if any), etc. System parts that unintentionally come into contact with powder blown up by, for example, electrostatic powder blowing, such as pumps or process chamber walls, are not considered process-related in this invention.

[0064] According to another aspect of the present invention, the above-mentioned object is achieved by a movable receiving device for a system for additively manufacturing workpieces from powder material, the movable receiving device comprising a build vessel in which the workpieces can be manufactured in layers, a) The movable receiving device comprises a powder application device, in particular a doctor blade, designed to transfer powder material from a storage container to a powder bed in the build container.

[0065] Preferably, a storage container for the powder material is also a component of the mobile receiving device.

[0066] This has the advantage that all major components are part of the movable receiving device.

[0067] The receiving device preferably comprises a support frame having at least two thermally isolated sections.

[0068] This is achieved by having a support frame with at least two sections that are not in direct contact with each other. One section can be connected to the powder application device, while the second section can hold the build chamber. This facilitates temperature control. During workpiece production, higher temperatures occur at the process level than in the surrounding area, so the material in the build chamber and adjacent assemblies is subjected to higher thermal loads and stresses than in the surrounding area. However, the highest precision must be ensured around the doctor blade, as any changes in the doctor blade position have a significant impact on the quality of the workpiece. Therefore, material expansion due to temperature fluctuations must be kept as low as possible. A support frame consisting of two sections that are thermally isolated from each other prevents harmful heat transfer to the doctor blade.

[0069] The build reservoir and the powder application device are preferably secured to different sections of a support frame.

[0070] The above problem is solved by a method for additively manufacturing a workpiece, the method comprising: a) Prepare the beam system described above; b) manufacturing a workpiece by processing a powder material with an energy beam in a process chamber; c) removing the powder application device from the process chamber; The problem is solved by a method comprising the steps of:

[0071] As a result, maintenance of the powder application device, particularly cleaning of powder residue, becomes easier.

[0072] The last-mentioned features and advantages of the removable powder coating device are advantageous not only for electron beam systems but also for laser beam systems. However, in particular, these features and advantages also apply, and in some cases are particularly advantageous, for the systems with pre-chambers and process chambers described at the beginning of this application. The applicant therefore reserves the right to combine these features and advantages with the features and advantages of the systems described at the beginning.

[0073] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Brief explanation of the drawings]

[0074] [Figure 1] 1 is a schematic diagram of an electron beam system according to the present invention for additively manufacturing a workpiece; FIG. [Figure 2] FIG. 1 is a side view of an electron beam system. [Figure 3] FIG. 1 is a top view of an electron beam system. [Figure 4] FIG. 1 is an isometric view of a receiving apparatus for an electron beam system. [Figure 5] FIG. 10 is a side view of an electron beam system according to another embodiment having two pre-chambers. [Figure 6a] 1A-1C are top views of various embodiments of an electron beam system having different pre-chamber locations. [Figure 6b] 1A-1C are top views of various embodiments of an electron beam system having different pre-chamber locations. [Figure 6c]1A-1C are top views of various embodiments of an electron beam system having different pre-chamber locations. [Figure 6d] 1A-1C are top views of various embodiments of an electron beam system having different pre-chamber locations. [Figure 7a] FIG. 1 is a side view of an electron beam system with a vertically oriented pre-chamber. [Figure 7b] FIG. 1 is a side view of an electron beam system with a vertically oriented pre-chamber. [Figure 8a] FIG. 1 is an isometric view of one embodiment of a receiving apparatus for an electron beam system. [Figure 8b] FIG. 1 is an isometric view showing a system for additively manufacturing a workpiece with a movable receiving device. DETAILED DESCRIPTION OF THE INVENTION

[0075] FIG. 1 shows a schematic diagram of the principles of an electron beam system 10 according to the present invention, including a process chamber 12 and a pre-chamber 14 connected to the process chamber 12 via an airlock door 16 .

[0076] Both the process chamber 12 and the pre-chamber 14 are heated and cooled via a commonly known suction system and vacuum pump (not shown in detail) at 10°C. -5 ~10 -2 The electron beam system 10 is defined by a vacuum housing that can be evacuated to pressures in the mbar range. However, with the airlock door 16 closed, the process chamber 12 and the pre-chamber 14 can be evacuated and filled separately. To this end, the electron beam system 10 can have gas inlets in the process chamber 12 and / or the pre-chamber 14, not shown here, for example, for inert gases.

[0077] Additionally, the pre-chamber 14 is provided with another airlock door 18 to an optional unloading station 20 located outside the pre-chamber 14 (see also FIG. 2).

[0078] The electron beam system 10, typically located in a flange of a vacuum housing, includes an electron beam generator 22 with a deflection device 24 that can generate and deflect an electron beam 26 within the process chamber 12.

[0079] As can be seen from Figures 1 and 3, in the embodiment shown, rails 34a, 34b, 36a, 36b, 38a, 38b are provided within the process chamber 12 and pre-chamber 14 and as part of the loading / unloading station 20 as a transport device 30 for the movable receiving device 32.

[0080] Rails 34a, 34b, 36a, 36b, 38a, 38b are interrupted in the area of ​​both airlock doors 16, 18, so that when airlock doors 16, 18 are closed, rails 34a, 34b are located entirely within process chamber 12 and rails 36a, 36b are located entirely within pre-chamber 14.

[0081] The transport device 30 allows the movable receiving device 32 to be transported back and forth between the pre-chamber 14 and the process chamber 12, and possibly a loading / unloading station, via an actuator 40, e.g., a driven roller, which will not be described in detail here.

[0082] Furthermore, as can be seen from FIG. 3, the transport device 30 having rails 34a, 36a, 38a and rails 34b, 36b, 38b has two parallel transport tracks, allowing the two movable receiving devices 32 to pass each other and be transported back and forth from the pre-chamber 14 to the process chamber 12 and vice versa.

[0083] Within the process chamber 12, the transport device 30 is connected to a coordinate table 39 that allows the receiving device 32 to be positioned and moved laterally within the process chamber 12.

[0084] Such a movable receiving device 32 is shown in FIG.

[0085] The receiving device 32 has, among other things, a support frame 33 as a basic component which cooperates with the transport device 30 .

[0086] The receiving device 32 further comprises a build vessel 40 in which a powder bed 42 (see FIG. 1) can be received, from which a workpiece 43 can be produced in an additive manufacturing process (3D printing).

[0087] Additionally, the receiving device 32 includes a storage container 44, here positioned adjacent to the build container 40, in which a powder material 46 is stored.

[0088] Both the shaping vessel 40 and the storage vessel 44 are inserted into the support frame 33 as separate components and can therefore be selected individually, i.e. in particular of different sizes, for each production process. Alternatively, the support frame 33 and the vessels 40, 44 can be fixedly connected or designed as one piece, with the entire receiving device 32 being replaced depending on the production process.

[0089] The build vessel 40 itself has a movable base plate 48 that can be raised and lowered via a lift piston 50 located within the process chamber 12 .

[0090] The same applies to the storage container 44, which has a movable base plate 52 that can be raised and lowered via a second lift piston 54.

[0091] A doctor blade 56 is provided above both containers 40, 44 as a powder application device, and as this doctor blade 56 moves, it scrapes the top layer of loose powder material 46 from the storage container 44 each time and applies it evenly onto the powder bed 42 in the building container 40.

[0092] In this case, the base plates 48, 52 move in opposite directions for each layer, so that the build reservoir 40 gets progressively larger and the storage reservoir 44 gets progressively smaller, depending on the amount of powder required.

[0093] In the simplest configuration, both containers 40, 44 have the same total cross-sectional area. If the total cross-sectional areas are different, the movement of the base plate 52 of the storage container 44 must be adjusted to accommodate the amount of powder required.

[0094] Alternatively, both the storage container 44 and the powder application device may be located within the process chamber 12 separate from the receiving device 32 .

[0095] Additionally, the receiving device 32 may have a powder overflow 58 and a heat shield above the build vessel 44 .

[0096] A control unit 60 is connected to the main components of the electron beam system 10, in particular the electron beam generator 22, the actuators of the transport device 30, the airlock doors 16, 18, and the lift pistons 50, 54, and controls the entire manufacturing process.

[0097] The manufacturing process according to the present invention proceeds as follows.

[0098] To manufacture a workpiece 43 in the electron beam system 10 according to the present invention, a receiving device 32 is placed in the process chamber 12 via the transport device 30 for receiving a powder bed 42 in the build vessel 40 .

[0099] In doing so, powder material 46 is placed in storage container 44 .

[0100] In the next step, the process chamber 12 is evacuated. After the target pressure is reached, the manufacturing process of the workpiece 43 begins. For this, powder material 46 is applied layer by layer in the build vessel 40 using a powder application device, and each layer is partially solidified with the electron beam 26.

[0101] Moving the electron beam 26 relative to the powder bed 42 can be accomplished by deflecting the electron beam 26 with the deflection device 24 or by moving the coordinate table 39 .

[0102] Optionally, the powder material 46 is preheated in a preheating step before the melting step to avoid powder loss and process interruptions due to electrostatic blowing of the material 46.

[0103] While the first workpiece 43 is being fabricated in the evacuated process chamber 12, the next build container 40 and possibly the next storage container 44 are prepared in another receiving device 32 external to the electron beam system 10. This second receiving device 32 is then placed in the pre-chamber 14, while the airlock door 16 to the process chamber 12 can remain closed. The pre-chamber 14 is then similarly evacuated.

[0104] Since each movable receiving device 32 can be prepared individually, it is also possible to fill the storage container 44 with a different material 46 at each time, so that different workpieces 43 can be produced successively from different materials.

[0105] To minimize powder consumption, build vessels 40 of different volumes are provided, which can be selected depending on the size of the workpiece 43 and introduced into the electron beam system 10 using the receiving device 32 .

[0106] Once the first workpiece 43 is completed, the airlock door 16 between the pre-chamber 14 and the process chamber 12 is opened. The completed workpiece 43 is transferred into the pre-chamber 14 on the transfer track of the transfer device 30. The second receiving device 32 is transferred into the process chamber 12 on the second transfer track.

[0107] The first workpiece 43 can be cooled in the pre-chamber 14 while the manufacturing process step of the second workpiece 43 begins in the process chamber 12. This step can be accelerated or precisely defined by introducing an inert gas such as helium. The cooling process of the workpiece 43 is monitored by a temperature measurement device 62 located in the electron beam system 10 and / or in the receiving device 32.

[0108] To monitor the process, particularly the cooling process, temperatures are measured by temperature measuring devices 62 at various points within the electron beam system 10 and in the receiving device 32. Suitable measurement points are, in particular, the base plate 48 of the build vessel 40, the walls of the build vessel 40, the storage vessel 44, and / or the powder overflow 58, along the doctor blade 56, in particular the doctor blade support and / or doctor blade rail, and combinations thereof. The temperature measuring devices 62 can also be mounted within the chamber, for example, on a sidewall or ceiling of the pre-chamber 14 or process chamber 12.

[0109] In one embodiment of the present invention, the control unit 60 is designed to monitor the cooling and, once a certain temperature is reached, automatically admit air to the pre-chamber 14, open the airlock door 18, and transfer the receiving device 32 from the pre-chamber 14.

[0110] The receiving device 32 can then again be prepared and placed in the pre-chamber 14 .

[0111] 5 shows an embodiment of the electron beam system 10 having two pre-chambers 14. In this embodiment, the transport device 30 can have one, two, or four transport tracks. In this system, multiple workpieces 43 can be cooled simultaneously in multiple receiving devices 32, further reducing the time required to cool each workpiece 43.

[0112] Even when two pre-chambers 14 are used, the conveying device 30 can be equipped with only one conveying track, so that one pre-chamber 14 can always be used for loading in a continuous flow manner, and the other pre-chamber 14 can always be used for cooling and unloading, thereby reducing the complexity of the conveying device 30.

[0113] 6a-6d and 7 show an embodiment of the electron beam system 10 in which the volume of the process chamber 12 is reduced and the transfer trajectory of the receiving device 32 is optimized.

[0114] The process chamber 12 of the embodiment shown in FIGS. 6 a - 6 d and 7 is designed to hold exactly one movable receiving device 32 .

[0115] FIG. 6d shows an embodiment of the electron beam system 10 with a turntable in the pre-chamber.

[0116] As shown in Figure 7, the unloading station 20 can be configured in the form of an enclosed working space. The unloading station 20 is preferably a glove box equipped with a powder suction device for safely unpacking and removing the workpieces. The unloading station 20 can be configured in the form of a transport unit that can be connected to the pre-chamber.

[0117] FIG. 7 shows an embodiment of the electron beam system 10 in which the pre-chamber 14 is arranged vertically. The pre-chamber 14 is equipped with an elevator 15. The elevator is designed to hold at least two movable receiving devices 32 vertically above and below each other. The pre-chamber shown in FIG. 7 has two holding positions for the elevator. In FIG. 7, the elevator 15 is in a lower position, allowing transfer from the unloading station 20 to the second loading level 15b of the elevator. The first loading level 15a of the elevator is designed to hold the movable receiving device 32. The upper holding position in FIG. 7 is designated by the reference number 17.

[0118] According to one possible mode of operation, the elevator 15 is loaded with a receiving device 32 and the pre-chamber 14 is evacuated. The airlock door 16 is then opened and the receiving device 32 is transferred into the process chamber. The airlock door 16 is then closed again. During electron beam powder processing in the process chamber, the airlock door 18 of the pre-chamber 14 is opened and another movable receiving device 32 is loaded onto the elevator 15. The airlock door 18 is then closed and the pre-chamber 14 is evacuated.

[0119] Alternatively, the elevator 15 can already be fitted with two receiving devices when loaded by moving the elevator from the first holding position to the second holding position or vice versa.

[0120] Before the powder processing step is completed, the elevator is brought to a position adjacent the still-vacant loading level and the airlock door 16. Once the powder processing step is completed, the airlock door 16 is opened and the receiving device with the processed powder is transferred from the process chamber 12 to the vacant position of the elevator. The elevator then moves and transfers the receiving device 32 with the unprocessed powder into the process chamber to be processed by the electron beam.

[0121] During the powder processing step in the second receiving device, the hot receiving device 32 remains in the pre-chamber with the processed powder and is cooled. In the auxiliary cooling process, the receiving device is placed in a strategic position, for example in the upper region of the pre-chamber or close to the inlet of the cooling means.

[0122] When the desired temperature is reached or before the powder processing step in the second receiving device is completed, the elevator moves into position, the airlock door 18 opens, and the receiving device is transferred out of the pre-chamber. A third receiving device can then be introduced into the pre-chamber, the airlock door 18 closed, and the pre-chamber evacuated. Exchange for a receiving device with processed powder occurs in the same manner as described above. This process can be repeated any number of times.

[0123] The vertical embodiment of the pre-chamber is particularly advantageous because it improves the utilization of the electron beam system with regard to residence time and evacuation issues, as well as reducing the space required, especially in terms of the system footprint.

[0124] Alternatively, the electron beam system 10 may be configured with two pre-chambers 14 and two transfer tracks. In one embodiment of the present invention, the electron beam system 10 includes multiple process chambers 12 and pre-chambers 14, between which a movable receiving device 32 according to the present invention is shuttled using a transfer device 30.

[0125] By paralleling the fabrication and cooling processes, the residence time of the workpiece 43 within the process chamber 12 can be significantly reduced, thereby optimizing the operation of the electron beam system 10.

[0126] FIG. 8a shows an isometric view of a preferred embodiment of a movable receiving device 32 for an electron beam system.

[0127] The movable receiving device 32 comprises a support frame 33 which holds the build vessel 40, the storage vessel 44 and the powder overflow 58 as well as a powder application device 56, a doctor blade unit.

[0128] In this case, the doctor blade unit has one or more doctor blades 45 that can move along rails via a doctor blade support, whereas the actuators for moving the doctor blades 45 are located inside the process chamber 12 and are not shown in the figure.

[0129] Also not visible in the figures, the support frame 33 has two sections that are thermally isolated from each other, where the doctor blade system 45 and the build vessel 40 are thermally isolated because they are not fixed to the same section.

[0130] FIG. 8 b shows an isometric view of the system 10 for additively manufacturing a workpiece by means of a movable receiving device 32 .

[0131] The movable receiving device 32 can be completely removed from the system 10 through the door 16. In this embodiment, the device 32 can be slid out of the process chamber 12 along rails. No disassembly steps are required to remove the movable receiving device 32.

[0132] The actuators for the lifting pistons 50 and 54 (see FIG. 1), the actuator for moving the doctor blade 45 and, optionally, the actuator for the transport device remain within the process chamber 12 and have suitable interfaces to the movable receiving device 32.

[0133] Here, an evacuable pre-chamber and / or unloading station is optional, but can facilitate handling and reduce non-productive time in the manufacturing process.

[0134] Complete removal of the movable receiving device 32 significantly simplifies service activities such as cleaning, repairs, etc. The increased accessibility reduces the risk of contamination with impurity particles when changing materials. The inventions disclosed herein include the following: [Aspect 1] 1. An electron beam system (10) for additive manufacturing of a workpiece (43), comprising: a) an evacuable process chamber (12); b) an electron beam generator (22) designed to direct an electron beam (26) within the process chamber (12) at different lateral positions of a powder bed (42) of powder material (46) to be processed; c) at least one evacuable pre-chamber (14) continuously connected in a vacuum-tight manner to the process chamber (12) via an airlock door (16) during operation of the electron beam system (10); d) at least one movable receiving device (32) for receiving said powder bed (42); e) a transfer device (30) capable of transferring said at least one receiving device (32) from said pre-chamber (14) to said process chamber (12); 1. An electron beam system comprising: [Aspect 2] The electron beam system of aspect 1, characterized in that the movable receiving device (32) has a build vessel (40) designed to receive the powder bed (42) and in which the workpiece (43) can be additively manufactured. [Aspect 3] 3. The electron beam system of claim 2, wherein the movable receiving device (32) comprises a storage container (44) for the powder material (46). [Aspect 4] 4. The electron beam system of claim 3, wherein the movable receiving device (32) is designed to transfer the powder material (46) from the storage container (44) to the build container (40) to form the powder bed (42) therein for additive manufacturing of the workpiece (43). [Aspect 5] 5. The electron beam system of claim 1, wherein the transport device (30) is designed to exchange a first movable receiving device (32) initially disposed in the pre-chamber (14) with a second movable receiving device (32) disposed in the process chamber (12). [Aspect 6] The electron beam system of any one of aspects 1 to 5, characterized in that the transport device (30) has at least two transport tracks along which at least two movable receiving devices (32) can be transported back and forth between the pre-chamber (14) and the process chamber (12) by passing each other. [Aspect 7] 7. The electron beam system of any one of aspects 1 to 6, wherein the pre-chamber (14) and / or the receiving device (32) comprises at least one temperature measuring device (62). [Aspect 8] 8. The electron beam system of any one of aspects 1 to 7, wherein a loading / unloading station (20) is connected to the pre-chamber (14), thereby enabling the at least one movable receiving device (32) to be transported into or out of the electron beam system (10). [Aspect 9] A method for additive manufacturing a workpiece (43), comprising: a) providing an electron beam system (10) according to any one of aspects 1 to 7; b) manufacturing a first workpiece (43) in a first movable receiving device (32) by processing the powder material (46) in the powder bed (42) using an electron beam (26) in the process chamber (12); c) equipping the pre-chamber (14) with a second movable receiving device (32) and then evacuating the pre-chamber (14); d) transferring the first movable receiving device (32) from the process chamber (12) to the pre-chamber (14) or to another pre-chamber (14); e) transferring the second movable receiving device (32) from the pre-chamber (14) to the process chamber (12); f) manufacturing a second workpiece (43) in the second movable receiving device (32) by processing the powder material (46) in the powder bed (42) using an electron beam (26) in the process chamber (12); g) cooling the first workpiece (43) in the first movable receiving device (32) in the pre-chamber (14); A method comprising: [Aspect 10] 10. The method of claim 9, comprising the step of: a) removing the first movable receiving device (32) together with the workpiece (43) from the pre-chamber (14). [Aspect 11] A system (10) for additive manufacturing of a workpiece (43), comprising: a) a process chamber (12), which is preferably evacuable; b) a shaping vessel (40) capable of producing a workpiece (43); c) a storage container (44) for the powder material (46); d) a powder application device (56, 45) designed to transfer the powder material (46) from the storage vessel (44) to the powder bed (42) in the build vessel (40); e) a beam generator (22) designed to direct an energy beam, in particular an electron beam (26), in the process chamber (12) at different lateral positions of the powder bed (42), f) the powder application device (56, 45) is removable from the process chamber; A system for additive manufacturing of a workpiece (43). [Aspect 12] The system (10) according to aspect 11, characterized in that it comprises at least one movable receiving device (32) having the shaping container (40), the storage container (44), and the powder application device (56, 45). [Aspect 13] 13. The system of claim 12, wherein the at least one movable receiving device (32) is transportable into and out of the process chamber (12) from a process chamber. [Aspect 14] A system according to aspect 12 or 13, characterized in that the at least one movable receiving device (32) is designed to receive the shaping containers (40) and / or the storage containers (44) having different dimensions, in particular different volumes. [Aspect 15] 15. The system of any one of aspects 11 to 14, wherein all process-related components are removable from the process chamber (12). [Aspect 16] 1. A movable receiving device (32) for a system (10) for additively manufacturing a workpiece (43) from a powder material (46), the workpiece (43) comprising a shaped container (40) that can be manufactured in layers, comprising: a) The movable receiving device (32) is characterized in that it comprises a powder application device (56, 45), in particular a doctor blade (45), designed to transfer the powder material (46) from a storage container (44) to a powder bed (42) in the build container (40). [Aspect 17] Aspect 17. The movable receiving device according to aspect 16, wherein the storage container (44) for the powder material (46) is also a component of the movable receiving device (32). [Aspect 18] 18. The movable receiving device according to aspect 16 or 17, wherein the receiving device (32) comprises a support frame (33) having at least two thermally separated sections. [Aspect 19] 19. The movable receiving device (32) according to any one of aspects 16 to 18, wherein the shaping vessel (40) and the powder application device (56, 45) are fixed to different sections of the support frame (33). [Aspect 20] A method for additive manufacturing a workpiece (43), comprising: a) providing a beam system (10) according to any one of aspects 11 to 15; b) manufacturing a workpiece by processing the powder material (46) with an energy beam (26) in the process chamber (12); c) removing the powder application device (56, 45) from the process chamber (12); A method comprising the steps.

Claims

1. 1. An electron beam system (10) for additive manufacturing of a workpiece (43), comprising: a) an evacuable process chamber (12); b) an electron beam generator (22) designed to direct an electron beam (26) within said process chamber (12) at different lateral positions of a powder bed (42) of powder material (46) to be processed; c) at least one evacuable pre-chamber (14) continuously connected in a vacuum-tight manner to the process chamber (12) via an airlock door (16) during operation of the electron beam system (10); d) at least one movable receiving device (32) for receiving said powder bed (42); e) a transfer device (30) capable of transferring said at least one movable receiving device (32) from said pre-chamber (14) to said process chamber (12); In an electron beam system having f) the transfer device (30) is designed to exchange a first movable receiving device (32) initially placed in the pre-chamber (14) with a second movable receiving device (32) placed in the process chamber (12); g) an electron beam system characterized in that the pre-chamber (14) is equipped with an elevator (15) designed to hold at least two movable receiving devices (32) above and below each other in a vertical direction.

2. 2. The electron beam system of claim 1, wherein the movable receiving device (32) has a build vessel (40) designed to receive the powder bed (42) and in which the workpiece (43) can be additively manufactured.

3. 3. The electron beam system of claim 2, wherein the movable receiving device (32) comprises a storage container (44) for the powder material (46).

4. 4. The electron beam system according to claim 3, characterized in that the movable receiving device (32) is designed to transfer the powder material (46) from the storage container (44) to the build container (40) to form there the powder bed (42) for additive manufacturing of the workpiece (43), respectively.

5. 5. The electron beam system according to claim 1, wherein the transport device (30) has at least two transport tracks along which at least two movable receiving devices (32) can be transported past each other and back and forth between the pre-chamber (14) and the process chamber (12).

6. Electron beam system according to any one of the preceding claims, characterized in that the pre-chamber (14) and / or the movable receiving device (32) comprise at least one temperature measuring device (62).

7. 7. The electron beam system according to claim 1, wherein a loading / unloading station (20) is connected to the pre-chamber (14), by means of which the at least one movable receiving device (32) can be transported into or out of the electron beam system (10).

8. A method for additively manufacturing a workpiece (43), comprising: a) providing an electron beam system (10) according to any one of claims 1 to 7; b) manufacturing a first workpiece (43) in a first movable receiving device (32) by processing the powder material (46) in the powder bed (42) with an electron beam (26) in the process chamber (12); c) equipping the pre-chamber (14) with a second movable receiving device (32) and then evacuating the pre-chamber (14); d) transferring the first movable receiving device (32) from the process chamber (12) to the pre-chamber (14) or to another pre-chamber (14); e) transferring the second movable receiving device (32) from the pre-chamber (14) to the process chamber (12); f) manufacturing a second workpiece (43) in the second movable receiving device (32) by processing the powder material (46) in the powder bed (42) with an electron beam (26) in the process chamber (12); g) cooling the first workpiece (43) in the first movable receiving device (32) in the pre-chamber (14); A method comprising:

9. 9. The method of claim 8, further comprising the step of: a) removing said first movable receiving device (32) together with said workpiece (43) from said pre-chamber (14).

10. A system (10) for additive manufacturing of a workpiece (43), comprising: a) an evacuable process chamber (12); b) a shaped vessel (40) capable of producing a workpiece (43); c) a storage container (44) for the powder material (46); d) a powder application device (56, 45) designed to transfer said powder material (46) from said storage vessel (44) to a powder bed (42) in said build vessel (40); e) a beam generator (22) designed to direct an energy beam within the process chamber (12) at different lateral positions of the powder bed (42), f) the system (10) comprises at least one movable receiving device (32) having the build container (40), the storage container (44), and the powder application devices (56, 45), characterized in that the at least one movable receiving device (32) is transportable into and out of the process chamber (12) from the process chamber so that the powder application devices (56, 45) can be removed from the process chamber; A system for additive manufacturing of a workpiece (43).

11. 11. The system according to claim 10, characterized in that the at least one movable receiving device (32) is designed to receive the shaping container (40) and / or the storage container (44) having different dimensions.

12. 12. The system according to claim 10 or 11, characterized in that all process-related components can be removed from the process chamber (12).

13. A movable receiving device (32) for a system (10) for additively manufacturing a workpiece (43) from a powder material (46), the workpiece (43) comprising a shaped container (40) that can be manufactured in layers, comprising: a) the movable receiving device (32) has a powder application device (56, 45) designed to transfer the powder material (46) from a storage container (44) to a powder bed (42) in the building container (40), the storage container (44) for the powder material (46) also being a component of the movable receiving device (32).

14. 14. A mobile receiving device according to claim 13, characterized in that the mobile receiving device (32) comprises a support frame (33) having at least two thermally separated sections.

15. 15. The movable receiving device (32) according to claim 14, wherein the shaping vessel (40) and the powder application device (56, 45) are fixed to different sections of the support frame (33).

16. A method for additively manufacturing a workpiece (43), comprising: a) providing a beam system (10) according to any one of claims 10 to 12, b) manufacturing a workpiece by processing the powder material (46) in the process chamber (12) with an energy beam (26); c) removing the powder application device (56, 45) from the process chamber (12); A method comprising the steps.

Images