Beam-generating assembly for a device for producing a component layer from at least one powder layer by means of an electron beam, and use of an aperture unit having an aperture

Abstract

The invention relates to a beam-generating assembly (38) for a device for producing a component layer from at least one powder layer. The beam-generating assembly (38) comprises a beam source unit (42) for generating an electron beam (40). Additionally, the beam-generating assembly (38) comprises a first focusing unit (50) and a second focusing unit (56). A focusing lens (58) of the second focusing unit (56) is arranged downstream of the first focusing unit (50) along a beam direction (R). In addition, the beam-generating assembly (38) comprises an aperture unit (64) having an aperture (66), which is arranged downstream of the first focusing unit (50) along the beam direction (R). The beam-generating assembly (38) also comprises a deflection unit (62) for moving and / or positioning the electron beam (40) on the component layer. The invention additionally relates to the use of an aperture unit (64) having an aperture (66) in a beam-generating assembly (38) for a device for producing a component layer.

Description

[0001] pro-beam GmbH & Co. KGaA

[0002] Zeppelinstr. 26, 82205 Gilching, Germany

[0003] Beam generation assembly for a device for producing a component layer from at least one powder layer using an electron beam, and use of an aperture unit with an aperture.

[0004] The invention relates to a beam generation assembly for a device for producing a component layer from at least one powder layer. The beam generation assembly comprises a beam source unit for generating an electron beam.

[0005] Furthermore, the invention relates to the use of an aperture unit with an aperture in a beam generation assembly for a device for producing a component layer from at least one powder layer using an electron beam.

[0006] Processes in which materials are applied layer by layer to create component layers are also known as additive or generative manufacturing processes. The materials can be supplied in powder form. These processes are characterized by the fact that a three-dimensional component is assembled from individual volume elements to achieve near-net-shape results. Using an electron beam, components can be manufactured with particularly high precision. This is because the electron beam can be focused onto a relatively small area of ​​the powder layer. Furthermore, a comparatively large amount of energy can be transferred to this relatively small area using the electron beam.

[0007] In this context, a beam generation assembly or electron beam column is understood to be that component of a device for producing a component layer which is designed to generate the electron beam and project it into a

[0008] TOP: To provide a TOP workspace or construction area, i.e., a room in which the component to be manufactured is to be produced.

[0009] The object of the present invention is to further improve such beam generation assemblies.

[0010] The problem is solved by a beam generation assembly for a device for producing a component layer from at least one powder layer. The beam generation assembly comprises a beam source unit for generating an electron beam. It also includes a first focusing unit with a first focusing lens for focusing the electron beam and a first centering unit for centering the electron beam on the first focusing lens. The first focusing unit is arranged downstream of the beam source unit along one beam direction. Furthermore, the beam generation assembly includes a second focusing unit with a second focusing lens for focusing the electron beam and a second centering unit for centering the electron beam on the second focusing lens. The second focusing lens is arranged downstream of the first focusing unit along the beam direction.The beam generation assembly also includes an aperture unit with one aperture. The aperture unit is arranged downstream of the first focusing unit along the beam direction. Furthermore, the beam generation assembly includes a deflection unit for moving and / or positioning the electron beam on the component layer and / or the powder layer. The deflection unit is arranged downstream of the second focusing unit and downstream of the aperture unit along the beam direction. In this context, a beam source unit comprises at least one anode and one cathode. Both can be ring-shaped. By applying an electrical voltage between the cathode and the anode, electrons are accelerated out of the cathode, forming the electron beam. The present beam generation assembly comprises a total of two focusing units, with the second focusing lens arranged downstream of the first focusing unit along the beam direction.In such a beam generation assembly, the first focusing unit can also be called an intermediate focusing unit, and the second focusing unit simply a focusing unit. Each of the first and second focusing units comprises a focusing lens. This is a magnetic lens, i.e., an assembly that typically includes several electrical coils and can thus focus the electron beam analogously to the function of an optical lens. Furthermore, each of the focusing units includes a centering unit. Each of the centering units also comprises at least two electrical coils, preferably four. The centering units allow the electron beam to be aligned to a center point and / or a central axis of the respective focusing lens. This facilitates precise and reliable focusing of the electron beam, as lens aberrations are avoided.A centering unit is also frequently referred to as an adjustment unit. The fact that the steelmaking assembly according to the invention comprises a total of two focusing units, i.e., the first focusing unit and the second focusing unit, means that the beam cross-section within the steelmaking assembly can be kept small. In other words, the electron beam is guided through the steelmaking assembly in a concentrated form. Consequently, a reliably and precisely focused electron beam can be provided in a workspace by means of the steelmaking assembly. Thus, a comparatively large amount of energy can be introduced into a comparatively small area of ​​the workspace. Furthermore, due to the deflection unit of the steelmaking assembly, the electron beam can be directed onto different areas within the workspace.The aperture assembly has the effect of preventing outgassing, which can occur during the interaction of the electron beam with the powder layer and / or the component being manufactured in the work area or build zone, from reaching those components of the steelmaking assembly located upstream of the aperture assembly along the electron beam path, i.e., between the beam source unit and the aperture assembly. In simpler terms, the aperture is designed so that the electron beam can pass through unimpeded, but such outgassing is largely prevented from passing through the aperture. This improves the reliability of the steelmaking assembly. This is because the described outgassing can lead to undesirable electrical arcing in the beam source unit, i.e., between the anode and the cathode of the beam source unit.This is prevented by the aperture unit with its aperture. The aforementioned outgassing can occur particularly when materials containing a component with a comparatively high melting point and a component with a comparatively low melting point are processed using the electron beam generated by the steelmaking assembly. This is because a comparatively large amount of energy must be introduced into the material by the electron beam to melt the component with the comparatively high melting point. This, in turn, can lead to the vaporization of the component with the comparatively low melting point. The present steelmaking assembly is therefore particularly well suited, among other things, for processing materials containing a component with a comparatively high melting point.Furthermore, the aforementioned outgassing occurs more frequently when comparatively large areas are exposed to the electron beam, i.e., when the steelmaking assembly is used to produce components with relatively large surfaces. The aperture unit with its aperture therefore also makes this beammaking assembly particularly well-suited for producing workpieces with especially large surfaces. In addition, the aperture unit with its aperture increases the precision of the beam guidance. Consequently, the overall precision of the electron beam provided by the steelmaking assembly is increased.

[0011] Optionally, the steelmaking assembly further comprises a beam shaping unit designed to influence or shape the cross-section of the electron beam provided by the beam source unit. In particular, the aim is to form a beam cross-section that is as circular as possible. Such a beam shaping unit can also be referred to as a stigmator. The beam shaping unit is also designed as an assembly with several electrical coils. Preferably, the beam shaping unit is arranged along the beam direction between the beam source unit and the first focusing unit, or between the first focusing unit and the second focusing unit. The use of a beam shaping unit thus further increases the precision of the electron beam provided by the steelmaking assembly.

[0012] The aperture unit can be positioned along the beam direction between the first and second focusing units. Alternatively, the aperture unit can be positioned along the beam direction between the centering unit and the focusing lens of the second focusing unit. In both configurations, the effects described above are achieved. In the second configuration, i.e., where the aperture unit is positioned along the beam direction between the centering unit and the focusing lens of the second focusing unit, the centering unit is located in front of the aperture along the beam direction. Therefore, in this second configuration, the electron beam can be aligned to a center point and / or a central axis of the aperture using the centering unit of the second focusing unit.In this variant, the centering unit of the second focusing unit can be considered both a centering unit for the second focusing unit and a centering unit for the aperture unit. The centering unit can therefore also be referred to as a shared centering unit. A separate centering unit for the aperture unit is not necessary in this variant.

[0013] According to one embodiment, the aperture unit includes a centering unit for centering the electron beam on the aperture. The centering unit is arranged in front of the aperture along the beam direction. In this embodiment, the centering unit of the aperture unit is provided in addition to the centering units of the focusing units. In other words, the aperture has a separate centering unit designed to align the electron beam to a center point and / or a central axis of the aperture. This further increases the precision of the electron beam provided by the steelmaking assembly. The aperture can have an aperture diameter of 1 mm to 8 mm, particularly 2 mm to 3 mm.It has been found that such apertures are particularly well-suited for allowing the electron beam to pass through while reliably containing outgassing from the processing area. Especially when the aperture unit includes a centering unit or can utilize the centering unit of the second focusing unit, apertures with particularly small aperture diameters can be used. In this context, the aperture diameter can be three to twenty times the focus diameter of the electron beam. The focus diameter can correspond to the full width at half maximum (FWHM).

[0014] According to one variant, the aperture can be configured as the axial end wall of a tubular aperture body. The aperture body is thus formed by a tubular component, with one of its central axes representing an axial direction. The tubular component is closed at one axial end by a wall that has an opening or aperture. Since the wall is located at the axial end, it can also be referred to as the end wall. In this way, the aperture can be provided in a reliable and robust manner. Such a configuration also facilitates the placement of the aperture, i.e., the axial end wall, at a desired location within the beam-generating assembly. This is because the tubular aperture body can be attached at virtually any point along its length within the beam-generating assembly.For example, the orifice body can be attached within the steelmaking assembly at an end opposite the axial end wall forming the orifice. Furthermore, the length of the orifice body can be varied along the axial direction to position the orifice at different locations within the steelmaking assembly. In cases where the orifice separates two gas spaces, such an orifice body can also serve as a reliable throttle. The tubular orifice body and its axial end wall, which forms the orifice, present a comparatively high flow resistance. This allows for the highly reliable separation of the two gas spaces, as will be explained in more detail below.

[0015] In one embodiment, the orifice plate separates two gas spaces. In particular, the gas spaces are vacuum spaces. The orifice plate can therefore be used in a steelmaking assembly comprising at least two gas spaces. The gas spaces can differ by pressure level and / or by the gas present in them. For example, an inert gas or process gas can be used in one of the gas spaces. In a case where the gas spaces are vacuum spaces, different pressure levels can prevail in the gas spaces. Here, a vacuum is understood in the technical sense, i.e., a vacuum denotes a state of a gas in a volume at a pressure lower than atmospheric pressure. Common types of technical vacuums are rough vacuum, fine vacuum, high vacuum, and ultra-high vacuum. As already explained, in such a case, the orifice plate acts as a throttle.

[0016] Preferably, the beam path of the beam generation assembly from the beam source unit to the deflection unit is essentially straight. The beam path of the beam generation assembly is understood to be those sections of the assembly through which the electron beam can propagate. These sections of the beam generation assembly are essentially straight, i.e., arranged along a straight line. This straight line corresponds to the beam direction, if an electron beam is present. In particular, the beam path deviates by less than 15° from a beam generation direction, which is defined as the direction along which the electrons forming the electron beam are accelerated between the cathode and the anode. The beam path of the beam generation assembly therefore has no kinks or deflections.The essentially straight beam path allows the electron beam to be supplied in an energy-efficient manner, i.e., with minimal loss. In one variant, the deflection unit can be water-cooled. During operation of the steelmaking assembly, the electrical coils of the deflection unit generate heat when they are driven to deflect the electron beam. Water cooling allows this heat to be dissipated efficiently and reliably. Consequently, the deflection unit can be operated reliably, even over a comparatively long operating period.

[0017] To enable water cooling, the deflection unit can include at least one cooling channel designed to carry a cooling medium. In particular, the cooling medium contains water.

[0018] According to one embodiment, the deflection unit can be configured to move the electron beam on the component layer by at least 5%, preferably at least 10%, of the distance between the deflection unit and the component layer. The deflection unit can therefore move the electron beam within a comparatively large area of ​​the component layer. In particular, the electron beam can be moved within an area formed by the component layer, i.e., planarly or planarly. Alternatively or additionally, the electron beam can be moved continuously, i.e., forming a linear exposure track, between points on the component layer and / or the powder layer. This allows the component layer to be produced quickly and reliably from the at least one powder layer. This is particularly advantageous because the electron beam can be deflected relatively quickly and precisely. Otherwise, i.e.,In a case where the electron beam cannot be deflected, or only slightly, the component layer would have to be moved. This is many times slower and more complex.

[0019] In one embodiment, the beam generation assembly further comprises a detector configured to detect the position of the electron beam in the region of the aperture unit. In particular, the detector is configured to detect the position of the electron beam relative to the aperture. In this way, it is possible to detect whether the electron beam is aligned relative to the aperture opening such that at least substantial portions of the electron beam pass through the aperture opening. Preferably, it is possible to detect whether the electron beam is centered relative to the aperture opening. In this context, the aperture and / or the aperture body can be made of an electrically conductive material, and the aperture and / or the aperture body can be electrically connected to the detector. In this example, the detector is configured to detect an electric current.In this way, the position of the electron beam can be determined by detecting whether the aperture and / or aperture body conducts an electric current. In particular, the magnitude of any electric current conducted by the aperture and / or aperture body can be detected. This configuration is based on the fact that if the electron beam at least partially strikes the aperture and / or aperture body, the electrons in the beam cause a current to flow within it. Consequently, the position of the electron beam within the aperture unit can be reliably and precisely determined.

[0020] In one example, the detector is connected to a notification unit, allowing a user of the beam generation assembly to be informed about the position of the electron beam in the area of ​​the aperture unit. For instance, the notification unit can issue a warning if the electron beam at least partially hits the aperture and / or the aperture body, i.e., if it does not substantially pass through the aperture opening. Optionally, in this case, it is conceivable to automatically switch off the beam generation assembly. Overall, this increases the precision and reliability in the production of a component layer from at least one powder layer. Furthermore, it improves operational safety.

[0021] In another example, the detector is coupled to a focusing unit associated with the aperture, specifically with a focusing unit of the aperture unit. Thus, based on a detection result from the detector, the focusing unit associated with the aperture, particularly the focusing unit of the aperture unit, can be operated. This focusing unit can therefore be operated in a closed-loop control system with respect to the positioning of the electron beam. Using such a beam generation assembly, the electron beam can be provided with exceptional precision.

[0022] In one variant, the second focusing unit is arranged downstream of the first focusing unit along the beam direction. This means that both the second focusing lens and the second centering unit are positioned downstream of the first focusing unit along the beam direction. In this way, the beam cross-section within the steelmaking assembly can be kept particularly small. In other words, the electron beam is guided through the steelmaking assembly in a highly concentrated form. Consequently, the steelmaking assembly can provide a reliably and precisely focused electron beam within the workspace.

[0023] Furthermore, the problem is solved by using an aperture unit with an aperture in a beam generation assembly for a device for producing a component layer from at least one powder layer. An electron beam is used. The aperture unit is arranged downstream of a first focusing unit along a beam direction. The first focusing unit comprises a first focusing lens for focusing the electron beam and a first centering unit for centering the electron beam on the first focusing lens. The aperture unit with the aperture has the effect that outgassing, which can occur during an interaction of the electron beam with the powder layer and / or the component to be produced in the work area or build area, can be contained by those components of the beam generation assembly that are located upstream of the aperture unit with the aperture along the electron beam direction.between the beam source unit and the aperture unit. In simpler terms, the aperture of the aperture is designed such that the electron beam can pass through unimpeded, but outgassing is largely prevented from passing through. This improves the reliability of the steelmaking assembly. This is because the outgassing described can lead to undesirable electrical discharges in the beam source unit, i.e., between the anode and the cathode of the beam source unit. This is prevented by the aperture unit. The aforementioned outgassing can occur particularly when materials are processed using the electron beam generated by the steelmaking assembly, materials that include a component with a comparatively high melting point and a component with a comparatively low melting point.This is because melting the component with a comparatively high melting point requires a relatively large amount of energy to be introduced into the material via the electron beam. This, in turn, can lead to the vaporization of the component with the comparatively low melting point. Therefore, by using an aperture unit with a single aperture, materials containing a component with a comparatively high melting point can be processed particularly well. The aforementioned outgassing occurs more frequently when comparatively large areas are exposed to the electron beam, i.e., when components with comparatively large surfaces are manufactured. The aperture unit with the aperture thus also enables the efficient production of workpieces with particularly large surfaces. Furthermore, the aperture unit with the aperture increases the precision of the beam guidance.Consequently, the overall precision of the component manufactured using the electron beam is increased.

[0024] The aperture unit can be positioned along the beam direction between the first and second focusing units. Alternatively, the aperture unit can be positioned along the beam direction between the centering unit and the focusing lens of the second focusing unit. In both configurations, the effects described above are achieved. In the second configuration, i.e., where the aperture unit is positioned along the beam direction between the centering unit and the focusing lens of the second focusing unit, the centering unit is located in front of the aperture along the beam direction. Therefore, in this second configuration, the electron beam can be aligned to a center point and / or a central axis of the aperture using the centering unit of the second focusing unit.In this variant, the centering unit of the second focusing unit can be considered both a centering unit for the second focusing unit and a centering unit for the aperture unit. The centering unit can therefore also be referred to as a shared centering unit. A separate centering unit for the aperture unit is not necessary in this variant.

[0025] According to one embodiment, the aperture unit includes a centering unit for centering the electron beam on the aperture. The centering unit is arranged along the beam direction in front of the aperture. In this embodiment, the centering unit of the aperture unit is provided in addition to the centering units of the focusing units. In other words, the aperture has a separate centering unit designed to align the electron beam to a center point and / or a central axis of the aperture. This further increases the precision of the electron beam provided by the steelmaking assembly.

[0026] The aperture can have a diameter of 1 mm to 6 mm, particularly 2 mm to 3 mm. Such apertures have proven particularly well-suited for allowing the electron beam to pass through while reliably containing outgassing from the processing chamber. Especially when the aperture unit includes a centering unit or can utilize the centering unit of the second focusing unit, apertures with particularly small diameters can be used.

[0027] According to one variant, the orifice can be configured as the axial end wall of a tubular orifice body. The orifice body is thus formed by a tubular component, with one of its central axes representing an axial direction. The tubular component is closed at one axial end by a wall that has an opening or aperture. Since the wall is located at the axial end, it can also be referred to as the end wall. In this way, the orifice can be provided in a reliable and robust manner. Such a configuration also facilitates the placement of the orifice, i.e., the axial end wall, at a desired location. This is because the tubular orifice body can be attached at virtually any point along its length within the steelmaking assembly.For example, the orifice plate body can be attached within the steelmaking assembly at an end opposite the axial end wall formed by the orifice plate. Furthermore, the length of the orifice plate body can be varied along the axial direction to position it at different locations within the steelmaking assembly. In cases where the orifice plate separates two gas spaces, such an orifice plate body can also serve as a throttle. This allows for the highly reliable separation of the two gas spaces, as will be explained in more detail below.

[0028] In one embodiment, the orifice plate separates two gas spaces, particularly where the gas spaces are vacuum spaces. The orifice plate can therefore be used in a steelmaking assembly comprising at least two gas spaces. The gas spaces can differ by pressure level and / or by the gas present in them. For example, one of the gas spaces can contain natural gas or process gas. In a case where the gas spaces are vacuum spaces, different pressure levels can prevail in the gas spaces. Here, a vacuum is understood in the technical sense, i.e., a vacuum denotes a state of a gas in a volume at a pressure lower than atmospheric pressure. Common types of technical vacuums are rough vacuum, fine vacuum, high vacuum, and ultra-high vacuum. As already explained, in such a case, the orifice plate acts as a throttle.

[0029] It is understood that the effects, advantages, and features mentioned above in connection with one of the beam generation assemblies and uses according to the invention also apply equally to the other beam generation assemblies and uses according to the invention. The invention is explained below with reference to various exemplary embodiments shown in the accompanying drawings. These show:

[0030] Figure 1 shows a device for producing a component layer from at least one powder layer, comprising a beam generation assembly according to the invention and in which an aperture unit is used according to the invention.

[0031] Figure 2 shows the beam generation assembly from Figure 1 in a schematic representation.

[0032] Depiction,

[0033] Figure 3 shows an alternative embodiment of the beam generation assembly in a view corresponding to Figure 2.

[0034] Figure 4 shows another alternative embodiment of the beam generation assembly in a view corresponding to Figures 2 and 3, and

[0035] Figure 5 shows another alternative embodiment of the

[0036] Beam generation assembly in a view corresponding to Figures 2 to 4.

[0037] Figure 1 shows a device 10 for producing a component layer 12 from at least one powder layer 14. In other words, Figure 1 shows a device 10 for the additive manufacturing of a component layer 12.

[0038] In the example shown in Figure 1, a component is built up three-dimensionally from a multitude of such component layers 12. It should be understood that the depicted component layers 12 are for illustrative purposes only.

[0039] Each component layer 12 is produced from a powder layer 14. The device 10 comprises a first vacuum chamber 16, which can also be referred to as a first gas chamber 16, in which a build area 18 is provided. The build area 18 is bounded by side walls 20. Furthermore, a base plate 22 is provided on the underside of the build area 18, which bounds the build area 18 downwards. The base plate 22 is coupled to a lifting unit 24, by means of which the base plate 22 can be moved in the vertical direction.

[0040] Building area 18 is open-ended.

[0041] The device 10 further comprises a powder reservoir 26, which is laterally bounded by walls 28 and downwardly bounded by a base plate 30. The base plate 30 is also coupled to a lifting unit 32, by means of which the base plate 30 can be moved in the vertical direction.

[0042] Powder reservoir 26 is also open at the top.

[0043] Furthermore, the device includes a doctor blade 34, which can be moved along a direction represented by an arrow 36 within the vacuum chamber 16. The doctor blade 34 is used to transfer powder from the powder reservoir 26 into the build area 18.

[0044] A powder layer 14 can thus be produced in the build area 18 by the coordinated interaction of the doctor blade 34, the lifting unit 24 of the build area 18, and the lifting unit 32 of the powder reservoir 26. For this purpose, the base plate 22 of the build area 18 is lowered by one increment using the lifting unit 24. The base plate 30 of the powder reservoir 26 is raised by one increment using the lifting unit 32. This results in a portion of the powder in the powder reservoir 26 projecting vertically beyond the wall 28 that laterally delimits the powder reservoir 26. This portion of the powder can then be transferred into the build area 18 by moving the doctor blade 34 from the position shown in Figure 1 along the direction indicated by arrow 36. The squeegee 34 is moved into the area of ​​the side wall 20 of the build area 18 that faces away from the powder reservoir 26. In this way, a powder layer 14 with a substantially constant thickness is generated in the build area 18.

[0045] In Figure 1, powdered sections are illustrated by dots. The component layers 12 are shown schematically, as already explained.

[0046] Furthermore, the device 10 includes a beam generation assembly 38, which is configured to generate an electron beam 40 and to provide it in the construction area 18, i.e. in the first vacuum space 16.

[0047] In the illustrated embodiment, the electron beam 40 is a pulsed electron beam.

[0048] The steel production assembly 38 includes a beam source unit 42. This is shown in more detail in Figure 2.

[0049] The beam source unit 42 comprises a cathode 44, a Wehnelt cylinder 46, and an anode 48. The electron beam 40 is generated by heating the cathode 44 either by an electric current or indirectly. This generates free electrons, which are then accelerated by an electrical voltage applied between the cathode 44 and the anode 48.

[0050] The Wehnelt cylinder 46 is an additional control electrode by means of which the beam current can be controlled. In the illustrated embodiment, the Wehnelt cylinder 46 is provided directly at the cathode 44.

[0051] Furthermore, the steel production assembly 38 includes a first focusing unit 50.

[0052] The first focusing unit 50 comprises a first focusing lens 52 for focusing the electron beam 40 and a first centering unit 54 for centering the electron beam 40 on the first focusing lens 52. Along the beam direction R, the first focusing unit 50 is arranged behind the beam source unit 42.

[0053] The centering unit 54 is arranged along the beam direction R in front of the focusing lens 52.

[0054] The steel production assembly 38 also includes a second focusing unit 56.

[0055] The second focusing unit 56 comprises a second focusing lens 58 for focusing the electron beam 40 and a second centering unit 60 for centering the electron beam 40 on the second focusing lens 58.

[0056] Along the beam direction R, the second focusing unit 56 is arranged behind the first focusing unit 50.

[0057] The second centering unit 60 is arranged along the beam direction R in front of the second focusing lens 58.

[0058] In addition, the beam generation unit 38 also includes a deflection unit 62.

[0059] The deflection unit 62 comprises several magnetic coils by means of which the electron beam 40 can be aligned within the build area 18. This means that the electron beam 40 can be selectively directed to different points within the build area 18 by means of the deflection unit 62. The electron beam 40 can then fuse those sections of the powder layer 14 toward which it is directed into a section of the component layer 12 to be produced. Sections of the powder layer that are not directed toward the electron beam 40 remain in powder form.

[0060] In other words, the deflection unit 62 serves to move and / or position the electron beam 40 on the component layer.

[0061] In this case, the deflection unit is configured to move the electron beam 40 on the component layer 12 by at least 10% of the distance between the deflection unit 62 and the component layer 12. In the illustrated embodiment, the electron beam 40 can be moved by approximately 25% of the distance between the deflection unit 62 and the component layer 12 by means of the deflection unit 62.

[0062] In Figure 2, contrary to reality, the electron beam 40 is depicted simultaneously in its two maximally deflected positions. This serves to illustrate the function of the deflection unit 62.

[0063] The deflection unit 62 is arranged along the beam direction R behind the second focusing unit 56.

[0064] In the illustrated embodiment, the deflection unit 62 is water-cooled.

[0065] Furthermore, in the illustrated embodiment the beam path is essentially rectilinear, i.e. the electron beam 40 can extend essentially along a straight line from the beam source unit 42 to the deflection unit 62.

[0066] The steel production assembly 38 also includes an aperture unit 64 with an aperture 66.

[0067] In the illustrated embodiment, the aperture 66 is configured as an axial end wall 68 of a tubular aperture body 70. The aperture body 70 is thus formed as a tube with a circular cross-section, which is closed at one axial end by an end wall 68 having an opening 72. This end wall 68 represents the aperture 66, and the opening 72 is the aperture opening.

[0068] The aperture opening 72 has a diameter of 2.5 mm in this case.

[0069] In the embodiment shown in Figure 2, the aperture unit 64 is arranged along the beam direction R between the first focusing unit 50 and the second focusing unit 56. The aperture 66 is thus positioned along the beam direction R behind the first focusing unit 50 and in front of the second focusing unit 56. Figure 3 shows an alternative embodiment of the steelmaking assembly 38. Only the differences compared to the embodiment shown in Figure 2 are discussed.

[0070] The embodiment according to Figure 3 differs from the previous embodiment in that the aperture unit 64 comprises a centering unit 74. The centering unit 74 is designed to align the electron beam 40 to a center point and / or a central axis of the aperture unit 64. The centering unit 74 is arranged along the beam direction R in front of the aperture 66.

[0071] Furthermore, reference can be made to the explanations regarding the aforementioned embodiment.

[0072] Figure 4 shows another alternative embodiment of the steel production assembly 38. Again, only the differences compared to the embodiments already described are discussed.

[0073] In the embodiment shown in Figure 4, the aperture unit 64 is arranged along the beam direction R between the centering unit 60 of the second focusing unit 56 and the focusing lens 58 of the second focusing unit 56. In this embodiment, the aperture unit 64 does not include its own centering unit.

[0074] Figure 5 shows an additional alternative embodiment of the steel production assembly 38. Again, only the differences compared to the embodiments already described are discussed.

[0075] In the embodiment shown in Figure 5, the first focusing unit 50 and the second focusing unit 56 are arranged in a nested configuration. This means that along the beam direction R, the centering unit 60 of the second focusing unit 56 is located between the centering unit 54 of the first focusing unit 50 and the focusing lens 52 of the first focusing unit 50. As before, the focusing lens 58 of the second focusing unit 56 is located behind the focusing lens 52 of the first focusing unit 50 along the beam direction R.

[0076] In the embodiment shown in Figure 5, the aperture unit 64 is also arranged between the focusing lens 52 of the first focusing unit 50 and the focusing lens 58 of the second focusing unit 56.

[0077] In the embodiment shown in Figure 5, the aperture unit 64 also does not include its own centering unit.

[0078] In all four embodiments mentioned, the aperture unit 64 or the aperture 66 serves to separate two gas spaces, which in this case are designed as vacuum spaces. The aperture 66 thus also acts as a throttle. The first vacuum space 16 is the vacuum space in which the assembly area 18 is located. The second vacuum space 76, or more generally, the second gas space 76, is the gas space in which the electron beam is generated. The first gas space 16 and the second gas space 76 differ in pressure level.

[0079] In the present case, the second gas space 76 has a higher vacuum than the first gas space 16.

[0080] For example, the pressure in the first gas space 16 is 10 4 bear.

[0081] In the second gas chamber 76, the pressure is, for example, 10 5 bear.

[0082] In all four variants mentioned, an aperture unit 64 with an aperture 66 is used in a beam generation assembly 38, wherein the beam generation assembly 38 is intended for use in a device 10 for producing a component layer 12 from at least one powder layer 14 using an electron beam 40.

[0083] The aperture unit 64 is arranged along a beam direction R behind the first focusing unit 50. Reference numeral list

[0084] 10 Device for producing a component layer

[0085] 12 component layers

[0086] 14 Powder coating

[0087] 16 first gas space, first vacuum space

[0088] 18 Construction area

[0089] 20 wall

[0090] 22 Base plate

[0091] 24 lifting units

[0092] 26 Powder reservoir

[0093] 28 Wall

[0094] 30 Base plate

[0095] 32 lifting units

[0096] 34 squeegees

[0097] 36 Arrow

[0098] 38 Beam Generation Assembly

[0099] 40 electron beam

[0100] 42 beam source units

[0101] 44 Cathode

[0102] 46 Wehnelt cylinders

[0103] 48 Anode

[0104] 50 first focusing unit

[0105] 52 first focusing lens

[0106] 54 first centering unit

[0107] 56 second focusing unit

[0108] 58 second focusing lens

[0109] 60 second centering unit

[0110] 62 Deflection unit

[0111] 64 aperture units

[0112] 66 aperture

[0113] 68 End wall

[0114] 70 aperture bodies

[0115] 72 Aperture, aperture

[0116] 74 Centering unit

[0117] 76 second gas space, second vacuum space

[0118] R Beam direction

Claims

Patent claims 1. Beam generation assembly (38) for a device (10) for producing a component layer (12) from at least one powder layer (14), comprising a beam source unit (42) for generating an electron beam (40), a first focusing unit (50) with a first focusing lens (52) for focusing the electron beam (40) and a first centering unit (54) for centering the electron beam (40) on the first focusing lens (52), wherein the first focusing unit (50) is arranged along a beam direction (R) behind the beam source unit (42), a second focusing unit (56) with a second focusing lens (58) for focusing the electron beam (40) and a second centering unit (60) for centering the electron beam (40) on the second focusing lens (58), wherein the second focusing lens (58) is arranged along the beam direction (R) behind the beam source unit (42). first focusing unit (50) is arranged, an aperture unit (64) with an aperture (66),which is arranged along the beam direction (R) behind the first focusing unit (50), and a deflection unit (62) for moving and / or positioning the electron beam (40) on the component layer (12) and / or the powder layer (14), wherein the deflection unit (62) is arranged along the beam direction (R) behind the second focusing unit (56) and behind the aperture unit (64).

2. Beam generating assembly (38) according to claim 1, wherein the aperture unit (64) is arranged along the beam direction (R) between the first focusing unit (50) and the second focusing unit (56), or wherein the aperture unit (64) is arranged along the beam direction (R) between the centering unit (60) of the second focusing unit (56) and the focusing lens (58) of the second focusing unit (56).

3. Beam generating assembly (38) according to claim 1 or 2, wherein the aperture unit (64) comprises a centering unit (74) for centering the electron beam (40) on the aperture (66), wherein the centering unit (74) is arranged along the beam direction (R) in front of the aperture (66).

4. Beam generating assembly (38) according to one of the preceding claims, wherein the aperture (66) has an aperture opening (72) with a diameter of 1 mm to 8 mm, in particular of 2 mm to 3 mm.

5. Beam generating assembly (38) according to one of the preceding claims, wherein the aperture (66) is designed as an axial end wall (68) of a tubular aperture body (70).

6. Beam generating assembly (38) according to one of the preceding claims, wherein the aperture (66) separates two gas spaces (16, 76), in particular wherein the gas spaces (16, 76) are vacuum spaces.

7. Beam generation assembly (38) according to one of the preceding claims, wherein a beam path from the beam source unit (42) to the deflection unit (62) is essentially straight.

8. Beam generating assembly (38) according to one of the preceding claims, wherein the deflection unit (62) is water-cooled.

9. Beam generation assembly (38) according to one of the preceding claims, wherein the deflection unit (62) is configured to move the electron beam (40) on the component layer (12) by at least 5%, preferably by at least 10% of a distance between the deflection unit (62) and the component layer (12).

10. Beam generating assembly (38) according to one of the preceding claims, further comprising a detector configured to detect a position of the electron beam in the region of the aperture unit (64).

11. Beam generating assembly (38) according to one of the preceding claims, wherein the second focusing unit (56) is arranged along the beam direction (R) behind the first focusing unit (50).

12. Use of an aperture unit (64) with an aperture (66) in a beam generation assembly (38) for a device (10) for producing a component layer (12) from at least one powder layer (14) using an electron beam (40), wherein the aperture unit (64) is arranged along a beam direction (R) behind a first focusing unit (50) and the first focusing unit (50) comprises a first focusing lens (52) for focusing the electron beam (40) and a first centering unit (54) for centering the electron beam (40) on the first focusing lens (52).

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