Additive manufacturing method with reduction of surface roughness of a shaped article produced in the manufacturing method

Abstract

A manufacturing method for the layer-by-layer additive manufacturing of a shaped article (10I), wherein a further layer (29a) is repeatedly added to a previous layer arrangement in the direction of a layer sequence, and in each case: VII. A new layer (22a) of a powder (17) is applied to the previous layer arrangement (13); VIII. In a melting area (23a) predetermined for the further layer (29a) and having a contour (25), the powder (17) of the new layer (22a) and at least part of the topmost layer of the previous layer arrangement (13) are melted with a first high-energy beam (24), in particular a laser beam or electron beam, is characterised in that in at least some of the further layers (29a), adding to the further layer (29a) further comprises: IX. A machining part (46) of the contour (25) is determined for the contour (25), and after step II, a second high-energy beam (31a), in particular a laser beam or electron beam, is moved along a line of travel which runs parallel to the machining part (46), as a result of which the further layer (29a) and at least part of the topmost layer of the previous layer arrangement (13) are melted along the line of travel, wherein the second high-energy beam (31a) has a second melt depth (33a) that is greater than the first melt depth (EST) of the first high-energy beam. The invention allows the surface roughness of the side faces of the shaped article to be reduced.

Description

[0001] Additive manufacturing process with reduction of the surface roughness of a molded article produced in the manufacturing process

[0002] Background of the invention

[0003] The invention relates to a manufacturing method for the layer-by-layer, additive manufacturing of a shaped body, wherein a previous layer arrangement is repeatedly supplemented by a further layer in the direction of a layer sequence, wherein the addition of a respective further layer comprises the following steps:

[0004] I. A new layer of powder is applied to the existing layer arrangement;

[0005] II. In a melting range predetermined for the further layer, the powder of the new layer is melted with a first high-energy beam, in particular a laser beam or electron beam, wherein at least a part of an uppermost layer of the previous layer arrangement is also melted, wherein the first high-energy beam has a first melting depth in the direction of the layer sequence and a first line energy, and wherein the predetermined melting range is delimited by a contour.

[0006] The invention further relates to a shaped body produced by such an additive manufacturing process.

[0007] Such a process is known, for example, from WO 2018 / 23171 Al.

[0008] Additive manufacturing processes, also known as 3D printing, enable the production of molded parts with complex geometries that would be impossible or only possible with considerable effort using conventional manufacturing methods such as milling or casting. The molded part is manufactured layer by layer, with a new layer of powder being applied to an existing layer arrangement, and the new layer is locally solidified. Local solidification is achieved using a high-energy beam, such as a laser beam or an electron beam.

[0009] Particularly in the production of molded parts made of copper-based powder, these often exhibit high surface roughness on the side surfaces created during production. This surface roughness can be removed through post-processing methods such as grinding, but this requires considerable effort.

[0010] WO 2018 / 23171 A1 discloses an additive manufacturing process involving the application of successive layers of a feed material to a substrate, wherein, after each layer has been applied, a selected region of the layer is melted. After each melting, the layer is examined for defects, and corresponding sub-segments of the molten region of the feed material are selected for reworking through a further melting process, in which a melt pool is created in the sub-segments using a vapor capillary. This allows irregularities on the surface of a respective layer to be reworked and eliminated. The quality and service life of the component are thus intended to be improved.

[0011] Object of the invention

[0012] The object of the present invention is to provide an additive manufacturing method for a molded body with which the roughness on the lateral surfaces of the molded body can be easily reduced. It is also an object of the invention to provide a molded body with reduced roughness on the lateral surfaces.

[0013] Description of the invention

[0014] This object is achieved according to the invention by a method according to claim 1. The features of the molded body according to the invention are specified in claim 17. Advantageous embodiments emerge from the dependent claims.

[0015] The manufacturing process according to the invention is characterized in that, at least for some of the further layers, the addition of the respective further layer further comprises the following step:

[0016] III. For the contour of the predetermined melting range of the further layer, a processing part of the contour is determined, which is formed by one or more parts of the contour or the entire contour, and after step II, a second high-energy beam, in particular a laser beam or electron beam, is moved along a travel line that runs parallel to the processing part of the contour, whereby the further layer and at least part of the uppermost layer, in particular the entire uppermost layer, of the previous layer arrangement is melted along the travel line, wherein the second high-energy beam has a second melting depth in the direction of the layer sequence, wherein the second melting depth is greater than the first melting depth by a factor FST, with FST>1. Within the scope of the present invention, porosity occurring on or near the side surfaces of the shaped body can be specifically reduced.This allows the roughness of the surface of the side surfaces of the molded body to be reduced.

[0017] In process step III, the powder of the additional layer melted in step II and the molten powder of the next layer or layers of the previous molded body below the additional layer in the direction of the layer sequence, and possibly also a certain amount of powder not melted in process step II, are melted together along the trajectory line. This reduces the porosity in the material, which remains particularly after melting in step II. The reduced porosity leads to a reduction in the roughness of the side surfaces along the contour built up during layer-by-layer production.

[0018] When melting the additional layer in process step II, high heat dissipation into powder located close to the melting zone (which is not melting) can often lead to sintering of powder particles onto the (previous) molded body, particularly when process step II is performed with the first high-energy beam as thermal conduction welding, and particularly when the powder is made of a material with good thermal conductivity, such as copper. In process step III, which is performed with a greater welding depth, a greater proportion of the energy from the second high-energy beam is usually directed into the melting zone than in process step II, so that less sintering of powder particles occurs, particularly when process step III is performed as deep penetration welding.The roughness of the molded body is generally determined by the last process performed on the side wall of the molded body in a respective layer, for which process step III is available within the scope of the invention. Accordingly, the roughness on the sides of the molded body can be reduced.

[0019] During the melting of the melting region of the additional layer according to process step II, the profile of the melt pool created by the first high-energy beam in the material of the new layer may exhibit a noticeable taper toward the uppermost layer of the previous layer arrangement. This can lead to wedge-shaped edges of the resolidified material in the region of the resulting side surfaces. In particular, during step III, previously unmelted powder may melt in the additional layer or a layer in the previous layer arrangement. These edges can be reduced or eliminated if necessary during step III.

[0020] The machining portion of the contour and the associated trajectory line can be determined solely based on the planned geometry of the molded body to be manufactured, particularly taking overhangs and projections into account. Inspection of the respective subsequent layer after step II, particularly to detect surface irregularities, is not necessary for determining the machining portion of the contour or the trajectory line for step III. Nevertheless, the measures of WO 2018 / 23171 A1 can be additionally applied (with a corresponding additional trajectory line that is independent of the contour), if desired.

[0021] The manufacturing process according to the invention eliminates the need for complex post-processing steps to reduce the roughness of the lateral surfaces of the molded body, in which, for example, internal channels could not be machined well.

[0022] Often FST>1.5, preferably FST>2, especially preferred FST>3.

[0023] For the first melting depth EST of the first high-energy beam and a layer thickness SD (measured within the respective melting range) of a respective layer, it typically applies that EST>1.1*SD, preferably EST>1.3*SD, particularly preferably EST>1.5*SD, and usually furthermore that EST<3*SD, preferably EST<2*SD.

[0024] For the second melting depth ZST of the second high-energy beam and a layer thickness SD of a respective layer, ZST>2*SD, preferably ZST>3*SD, and usually also ZST<8*SD, preferably ZST<6*SD, particularly preferably ZST<4*SD applies.

[0025] Typically, the first high-energy beam and the second high-energy beam have the same spot size and are generated with the same high-energy beam source. To generate the increased second melting depth, the second high-energy beam can, for example, propagate more slowly than the first high-energy beam, and / or the energy output for the second high-energy beam can be higher than for the first high-energy beam. Alternatively, it is also possible to select different spot sizes for the first high-energy beam and the second high-energy beam, or to select different high-energy beam sources for generating the first and second high-energy beams, possibly with different energy outputs and / or different propagation speeds. A spot size can be determined in the workpiece surface plane. High-energy beams used within the scope of the invention can be, for example, laser beams or electron beams.The high-energy beams have sufficient energy to melt the powder material.

[0026] Within the scope of the invention, the second high-energy beam can move with its center point along the travel line, or a moving (time) average of the position of the center point moves along the travel line (e.g., when a fast oscillation is applied to the second high-energy beam compared to the feed rate).

[0027] In the latter case, it is possible, for example, for the center of the second high-energy beam to have a movement curve with a spatially oscillating shape (transverse to the local feed direction), whereby an interpolation line through the inflection points of the oscillations corresponds to the travel line, i.e., runs (essentially) parallel to the machining part of the contour. Likewise, it is possible, for example, for the center of the second high-energy beam to have a movement curve with a spatially oscillating shape, whereby an interpolation line through geometric centers of gravity in successive periods of the oscillations corresponds to the travel line, i.e., runs (essentially) parallel to the machining part of the contour, whereby a geometric center of gravity of the movement curve is determined in each of the successive periods.

[0028] The contour corresponds to the edge line of the (predetermined) melting area.

[0029] To process the respective predetermined melting area, patterns, also called "hatches" or "hatchings", are determined, which define the movement curves or vectors of the first high-energy beam when melting the new layer.

[0030] Within the scope of the manufacturing process according to the invention, a modified process regime is achieved through specific parameter settings, in particular the second melting depth (which can be influenced in particular by a second line energy of the second high-energy beam, or the welding speed and energy output (watts per second), as well as the spot size of the second high-energy beam). Step III ("contour control") allows the formation of the (lateral) surface layer to be specifically switched, resulting in lower porosity and less roughness of the surface of the molded body.

[0031] Preferred variants of the invention

[0032] A variant of the manufacturing method according to the invention is characterized in that l <FST<10, bevorzugt 1,5<FST<8, besonders bevorzugt 2<FST<8, ganz besonders bevorzugt 4<FST<6 gilt. Je nach Schichtdicke und der Anzahl der Schichten, über die das Material in Schritt III verschweißt werden sollen, können ein passender FST insbesondere über eine geeignete Linienenergie gewählt werden. Durch einen FST zwischen 1 und 10 kann typischerweise Pulvermaterial in einer ausreichenden Zahl an Schichten verschweißt werden, und eine Glättung der Oberfläche des betreffenden Formkörpers kann bewirkt werden, ohne eine unnötig hohe Leistungsdichte zur Verfügung stellen zu müssen.In an advantageous variant, the second high-energy beam has a second line energy, wherein the second line energy is greater than the first line energy by a factor FL, with FL>1, in particular wherein a spot size of the second high-energy beam is the same size as or greater than a spot size of the first high-energy beam. Increasing the line energy from the first high-energy beam to the second high-energy beam is usually easy to set up in terms of equipment. Furthermore, in practice, porosity and roughness can be reduced particularly well with this procedure, in particular when the same high-energy beam source with a constant spot size was used to generate the first and second high-energy beams. The line energy can be increased by reducing the welding speed and / or increasing the energy of the high-energy beam (e.g. by increasing the laser power).The line energy (also referred to as the energy per unit length) is the energy (joules per meter) introduced into the workpiece by a high-energy beam per length of the welding path. Furthermore, FL>1.3 is often the case, preferably FL>1.5, particularly preferably FL>2, and most particularly preferably FL>4.

[0033] An advantageous further development of this variant of the method according to the invention is characterized in that l <FL<20, bevorzugt l,3<FL<10, besonders bevorzugt 2<FL<8 gilt. Mit einer FL zwischen 1 und 20 wird typischerweise eine ausreichende zweite Schmelztiefe erzielt, um das Material von Schmelzbereichen mehrerer aufeinanderfolgender Schichten aufzuschmelzen und das Material einer Schicht mit dem Material der jeweils benachbarten Schichten zu verschmelzen.

[0034] A variant in which a spot size of the second high-energy beam is smaller than a spot size of the first high-energy beam is also advantageous, in particular wherein the second high-energy beam has a second line energy and the second line energy is equal to or smaller than the first line energy. By changing the spot size, the welding depth for the first and second high-energy beams can also be changed in a comparatively simple manner, in particular wherein the line energy does not need to be changed.

[0035] In a further variant of the process, step III is carried out as each additional layer is added to the existing layer arrangement. Since the processing parts of the contour of the respective melting area are traversed by the second high-energy beam in each layer in step III, deviations between the contours of adjacent layers in terms of their size, shape or position in the respective layer can be taken into account with high precision in the respective step III. Material melted in each step II can be melted again to a particularly large extent in step III if slopes need to be taken into account. In addition, melting material along the contours of the melting areas of the top two (adjacent) layers is sufficient to melt the material in all layers within the scope of step III, so that correspondingly small second welding depths can be used in step III.

[0036] An alternative advantageous variant of the method is characterized in that step III is carried out when adding every nth additional layer to the existing layer arrangement, where n>2. In this embodiment, the time required to carry out the method according to the invention is reduced, since the melting according to step III does not take place in every layer.

[0037] A further development of the above variant is characterized by the fact that n is chosen with n <ZST / SD, mit ZST: zweite Schmelztiefe und SD: Schichtdicke einer jeweiligen Schicht, insbesondere wobei weiterhin auch gilt n> (ZST / SD)-1. This ensures that all layers are melted in a time-efficient manner during step III. If the ZST / SD ratio results in an integer, n is preferably equal to this integer. If the ZST / SD ratio results in a rational number that is not an integer, n is preferably equal to the nearest integer smaller than the ZST / SD ratio.When melting along the contour of a melting region in a further layer with a second high-energy beam according to step III, the powder material is preferably melted accordingly up to the next layer below this further layer in the direction of the layer sequence in which the melting process according to step III was previously carried out; this is particularly efficient and time-saving.

[0038] A preferred variant of the manufacturing process is one in which the melting in step II is carried out by thermal conduction welding and the melting in step III is carried out by deep penetration welding. The thermal conduction welding in step II is simple and quick to perform. The deep penetration welding in step III results in a weld seam with a particularly uniform and defect-free composition and good smoothing of the (lateral) surface of the molded body. During thermal conduction welding, no vapor capillary is created in the molten material, and / or the weld seam produced has a ratio of depth T to width B with T / B<1.4, usually 0.7. <T / B<l,3. Beim Tiefschweißen wird eine Dampfkapillare im aufgeschmolzenen Material erzeugt, und / oder die erzeugte Schweißnaht hat ein Verhältnis von Tiefe T zu Breite B mit T / B> 1.4, mostly with 1.5 <T / B<12, bevorzugt mit 2<T / B<10, besonders bevorzugt zwischen 4<T / B< 8.It should be noted that in the literature (in addition to thermal conduction welding and deep penetration welding), another welding regime called transition mode, also referred to as transition mode welding, is occasionally discussed. This welding regime is located in the transition area between thermal conduction welding and deep penetration welding. Transition mode will not be discussed in detail here, especially since the definition of the welding regimes is not uniform in the literature. For the purposes of the present invention, thermal conduction welding and deep penetration welding can be classified as indicated above.

[0039] In a further variant of the manufacturing method, in step III, a center point of a cross-sectional area of ​​the second high-energy beam in the melting region of the further layer is moved to a maximum of a predetermined safety distance from the processing part of the contour of the melting region, in particular wherein the safety distance corresponds to at least half the diameter of the cross-sectional area of ​​the second high-energy beam or at least half the width B of a weld seam created by the second high-energy beam. The safety distance can be used to prevent unwanted melting of powder that has not yet been melted (in particular in a preceding step II) during step III.Due to the safety distance, melting in step III typically occurs essentially only within the melting range of the additional layer; for this purpose, the safety distance can be selected corresponding to half the spot diameter of the second high-energy beam or half the width of the weld seam. By using an even larger safety distance, it can be achieved that in the direction of the layer sequence below this melting range, melting is limited to parts of the layer arrangement containing material that has already been melted, particularly in the case of inclined side surfaces. Powder material below the melting range of the additional layer, which is not intended to be melted, is then not irradiated by the second high-energy beam due to the safety distance. This prevents an undesired change in the shape of the molded body in step III.The cross-sectional area of ​​the high-energy beam can be determined, for example, at the surface of the further layer.

[0040] A further development of the aforementioned variant of the manufacturing method according to the invention is characterized in that for an overhang part of the processing part of the contour, under which there is at least locally unmelted powder in the direction of the layer sequence in the previous layer arrangement in the area up to the second melting depth and at which an angle of inclination of the shaped body with respect to the direction of the layer sequence reaches a maximum of a first limit angle GW1, a larger safety distance is selected than for a processing part of the contour under which there is no unmelted powder in the direction of the layer sequence in the previous layer arrangement in the area up to the second melting depth, wherein the first limit angle GW1 is selected to be 30° or less, preferably 25° or less, particularly preferably 20° or less, in particular wherein the safety distance increases with the size of the angle of inclination.The angle of inclination can be determined locally in the area of ​​the second melt depth. This refinement ensures that in the overhang portion (which represents a "downskin" region of the molded body), the melt pool of the second high-energy beam moves closer to the (local) contour with increasing depth in step III, preferably with the melt pool only reaching the (local) contour at its greatest depth. Conversely, outside the overhang region, the smaller safety margin generally allows the melt pool to move close to or reach the (local) contour along its second melt depth.The safety distance can thus be easily selected such that no unmelted powder is melted in the direction of the layer sequence below the overhang part of the contour, which is not intended to be fused with the molded body, and at the same time a high proportion of the previously melted material (particularly in step II) is melted again in step III to reduce defects. Below the processing part of the contour, below which there is no unmelted powder in the direction of the layer sequence in the previous layer arrangement in the area up to the second melting depth, the molded body extends to this depth, for example, parallel to the direction of the layer sequence in the previous layer arrangement.

[0041] A variant of the method is advantageous, characterized in that the machining part of the contour omits at least one overhang portion of the contour, below which, in the direction of the layer sequence in the previous layer arrangement, there is at least locally unmelted powder in the region up to the second melting depth, and at which an angle of inclination of the molded body with respect to the direction of the layer sequence is greater than a second critical angle GW2, wherein the second critical angle GW2 is selected to be greater than 20°, preferably greater than 25°, particularly preferably greater than 30°. By omitting the overhang portion of the contour (which represents a "downskin" region of the molded body), it is ensured that no unmelted powder is melted below the overhang portion of the contour, which is not intended to be fused with the molded body. Note that GW2>GW1 applies if overhang portions and overhang portions are taken into account.The inclination angle can be determined locally in the area of ​​the second melting depth.

[0042] In a further development of the aforementioned variant, the machining portion of the contour extends along the entire contour, except for the overhang portion of the contour. This reduces the roughness of the powder melted in step II along the entire contour of the respective melting area, except in the areas where smoothing is impossible due to the excessively large inclination angle. Thus, a comparatively large portion of the (lateral) surface of the molded body is advantageously smoothed.

[0043] In a preferred variant of the manufacturing process, the machining portion of the contour accounts for at least 40%, preferably at least 60%, of the total contour. This ensures that the roughness is reduced at least in approximately half of the respective contour, and thus approximately half of the (lateral) surface of the molded body.

[0044] A further embodiment of the manufacturing process is characterized in that the powder contains copper, in particular with at least 50 wt% copper. With copper materials, any roughness that occurs on the side surfaces of 3D-printed molded bodies can be very effectively reduced within the scope of the invention. A molded body consisting predominantly of copper is also characterized by comparatively high corrosion resistance as well as high electrical and thermal conductivity. Surfaces of copper components produced using the powder bed process typically suffer from a characteristic high porosity, which is reflected in large surface roughness values, for example of approximately 15 pm. These roughness values, e.g., mean roughness values ​​Ra, can vary considerably, for example due to different layer times in the manufacturing process. Roughness values ​​of less than 10 pm, in particular, can be achieved using the manufacturing process according to the invention.The molded body is first built up from the powder bed in each layer using a hatching process, and then a contour scan is carried out with specifically modified operating parameters ("modified process regime"). This results in a significantly reduced surface roughness on the side surfaces of the finished molded body. It should be noted that due to the comparatively high thermal conductivity of pure copper, reducing surface roughness by reducing the spot size of the high-energy beam used or the thickness of the layers is less effective than with other materials for the additive manufacturing of molded bodies. The modified process regime can be achieved, for example, by ensuring that the line energy of the second high-energy beam is greater than a critical threshold of 3 J / mm for a layer thickness of 60 μm for the powder layers.In a line energy range of 2 J / mm to 3 J / mm, improved roughness values ​​typically only occur in certain areas of the molded body's surface. This applies even when the layer thickness is increased by a factor of 2.5.

[0045] A variant of the manufacturing process is advantageous in which the first high-energy beam and / or the second high-energy beam is a laser beam with a mean wavelength in a wavelength range of 500 nm to 560 nm. Using a laser beam with light in the green wavelength range reduces the formation of spatter during powder melting, particularly with copper-based powder. This results in a defect-free and uniform weld. In particular, a laser beam with a mean wavelength of 515 nm and a spot with a diameter of 200 pm in the processing plane can be used.

[0046] A molded body according to the invention is produced by a manufacturing method according to one of the preceding embodiments. The roughness of the surface of such a molded body is reduced during its production with comparatively little time expenditure.

[0047] Further advantages of the invention will become apparent from the description and the drawings. Likewise, the features mentioned above and those further described can be used individually or in combination. The embodiments shown and described are not intended to be exhaustive, but rather are exemplary in nature for describing the invention.

[0048] Detailed description of the invention and drawing

[0049] Fig. 1 shows, for a first variant of the manufacturing method according to the invention, a schematic longitudinal section through a first embodiment of a shaped body in a manufacturing chamber, wherein a new layer of powder is applied in the manufacturing chamber (step I);

[0050] Fig. 2 shows a schematic longitudinal section through the molded body in the manufacturing chamber of Fig. 1, wherein a melting region is irradiated with a first high-energy beam (step II);

[0051] Fig. 3 shows a schematic longitudinal section through the molded body in the manufacturing chamber of Fig. 1, after irradiation by the first high-energy beam (after step II);

[0052] Fig. 4 shows a schematic longitudinal section through the molded body in the manufacturing chamber of Fig. 1, wherein the melting area is irradiated with a second high-energy beam (step III);

[0053] Fig. 5 shows, for a second variant of the manufacturing method according to the invention, a schematic longitudinal section through a second embodiment of a molded body in a manufacturing chamber, wherein several new layers are applied one after the other to a previous layer arrangement and melted (steps I / II several times in succession);

[0054] Fig. 6 shows a schematic longitudinal section through the molded body of Fig. 5 in the production chamber after melting of melt areas in the new layers by the first high-energy beam (after last step II);

[0055] Fig. 7 shows a schematic longitudinal section through the molded body of Fig. 5 in the manufacturing chamber, wherein the melting area is irradiated with a second high-energy beam (step III);

[0056] Fig. 8 shows a schematic longitudinal section through the shaped body after irradiation by the second high-energy beam (after step III) for the first and second variants of the manufacturing process according to the invention;

[0057] Fig. 9 shows, for a third variant of the manufacturing method according to the invention, a schematic longitudinal section through a third embodiment of the molded body in the manufacturing chamber, with a slight inclination of a side surface of the molded body, during irradiation by the second high-energy beam (step III);

[0058] Fig. 10 shows, for a fourth variant of the manufacturing method according to the invention, a schematic longitudinal section through a fourth embodiment of the molded body in the manufacturing chamber, with a medium inclination of a side surface of the molded body, during irradiation by the second high-energy beam (step III);

[0059] Fig. 11 shows, for a fifth variant of the manufacturing method according to the invention, a schematic longitudinal section through a fifth embodiment of the molded body in the manufacturing chamber, with a large inclination of the side surface of the molded body, during irradiation by the second high-energy beam (step III);

[0060] Fig. 12 shows a schematic plan view of another layer of a layer arrangement with which a sixth embodiment of the molded body is manufactured; Fig. 13 shows a first schematic central longitudinal section through the layer arrangement of Fig. 12;

[0061] Fig. 14 shows a second schematic edge-side longitudinal section through the layer arrangement of Fig. 12.

[0062] Fig. 1 shows a schematic longitudinal section through a first embodiment of a (partially manufactured) molded body IO 1 in a production chamber 11 for additive manufacturing of the molded body 10 1. The molded body 10 1 is manufactured layer by layer, whereby a previous layer arrangement 13 is successively supplemented by further layers.

[0063] The previous layer arrangement 13 accordingly comprises a plurality of layers, designated here by way of example as 12a, 12b, 12c. The layers 12a-12c of the previous layer arrangement 13 are each partially (outside the volume of the molded body 10) 1 ) as unfused powder 17, and partly as fused material, which is in the molded body 10 1 The (partially finished) molded body 10 1 is therefore surrounded by powder 17 in the previous layer arrangement 13.

[0064] The molded body 10 1 has a first side surface 14a and a second side surface 14b, which lead to the surface 15 of the molded body 10 1The sequence of powder layers is oriented upwards in the vertical direction 16. The side surfaces 14a, 14b of the molded body 10 1 extend in this direction 16 in the embodiment shown.

[0065] The powder 17 here is a metallic powder and contains, in particular, copper. The molded body 10 1 and the layer arrangement 13 are arranged on a vertically adjustable lifting table 18. The molded body is thus grown on the upper side of the lifting table 18 in the variant shown; if desired, a substrate on which the molded body grows can also be arranged on the lifting table 18 (not shown in detail). In the horizontal direction, the powder layers are held by side walls 19a, 19b.

[0066] In a step I of the manufacturing method according to the invention shown in Fig. 1 in the first variant shown, a new layer 22a of powder 17 is applied to the uppermost layer 20a of the existing layer arrangement 13 in direction 16 of the layer sequence by an application unit 21 to extend the existing layer arrangement 13 by a further layer 29a. If necessary, the applied new layer 22a can be evened out with a brush (not shown in detail).

[0067] Fig. 2 illustrates the next step II of the first variant of the manufacturing process, wherein a first predetermined melting region 23a (cf. Fig. 12) in the new layer 22a is irradiated with a first high-energy beam 24 in order to melt and solidify the powder 17 in the melting region 23a. In the variant shown, the high-energy beam 24 is a laser beam, for example, with a mean wavelength of 515 nm. In the variant shown, the first high-energy beam 24 effects thermal conduction welding. The first predetermined melting region 23a is bordered by a contour 25. A first melt pool 26a of the material (formerly powder) melted by the first high-energy beam 24 is visible in the cross-section shown (which here is perpendicular to the feed direction of the high-energy beam 24 relative to the molded body 10). 1lies) is approximately conical in shape and tapers opposite to the direction 16 of the layer sequence. The melt pool 26a has a first melt depth 27 (also called EST) and extends into a part of the uppermost layer 20a of the previous layer arrangement 13 beneath the new layer 22a; the first melt depth EST here corresponds approximately to 1.6 times a layer thickness SD. The first high-energy beam 24 creates a weld seam, essentially corresponding to the geometry of the melt pool 26a, with a width B and a depth T, here with T / B of approximately 0.9. By moving the first high-energy beam 24 perpendicular to the direction 16 of the layer sequence, the first melt pool 26 is moved along a movement curve 28, here in the form of a hatching (cf. also Fig. 12), which moves the first high-energy beam 24 in the longitudinal section shown in Fig. 2 along the contour 25 perpendicular to the plane of the drawing in Fig. 2. In the longitudinal section of Fig.2, the powder 17 is melted between the opposite sides of the contour 25 with the first high-energy beam 24 in order to form a further (layer-shaped) section of the shaped body 10 in the new layer 22a or the further layer 29a. 1 in the production chamber 11; this section is connected to the mold body 10 1 in its uppermost layer 20a in the previous layer arrangement 13 integrally connected, since the molded body 10 1 in its uppermost layer 20a was melted by the first high-energy beam 24.

[0068] Fig. 3 shows the molded body 10 1 in the production chamber 11 after irradiation by the first high-energy beam 24 (see Fig. 2). After step II, the side surfaces 14a, 14b of the molded body 10 1in the area of ​​the further layer 29a, an undesirable roughness is present due to porosity (not shown in detail). Likewise, an undesirable roughness exists in the area of ​​the further layer 29a on the side surfaces 14a, 14b due to the formed body 10 1 sintered powder particles (also not shown in detail), since the first high-energy beam 24 has noticeably introduced heat into the unmelted powder 17 adjacent to the melt pool 26a.

[0069] In the variant shown, notches 30a, 30b are furthermore formed in the molded body 10 by the profile of the first melt pool 26a (cf. Fig. 2) at the edge of the melting area 23a of the further layer 29a. 1 formed, the width of which increases towards the uppermost layer 20a of the previous layer arrangement 13 (i.e., downwards in Fig. 3). These notches 30a, 30b can also lead to an undesirable roughness of the side surfaces 14a, 14b of the molded body 10 1which belong to its surface 15.

[0070] Fig. 4 shows the molded body 10 1in the production chamber 11, wherein, according to a next step III of the production method, the melting region 23a of the further layer 29a is irradiated with a second high-energy beam 31a. The second high-energy beam 31a creates a second melt pool 32a with a second melting depth 33a that is greater than the first melting depth 27 (also referred to as ZST); the second melting depth ZST here corresponds approximately to 3.6 times a layer thickness SD. Furthermore, in the variant shown, the second high-energy beam 31a has a greater line energy than the first high-energy beam 24, for example, by scanning the second high-energy beam 31a more slowly than the first high-energy beam 24; the laser power and the spot size of the first high-energy beam 24 and the second high-energy beam 31a are each the same in this example.Alternatively, in another example, the spot size (spot diameter at the surface of the upper / further layer 29a) of the second high-energy beam 31a could be selected to be smaller than the spot size of the first high-energy beam 24, with the same line energy of both high-energy beams 24, 31a (not shown in detail). The second line energy is selected to be sufficiently large so that a vapor capillary 34a forms in the second molten pool 32a. The second high-energy beam 31a creates a weld seam, essentially corresponding to the geometry of the molten pool 32a, with a width B and a depth T, here with T / B of approximately 2.0. The second high-energy beam 31a causes deep welding of the part of the molded body 10 melted by the second high-energy beam 31a. 1 .

[0071] The second high-energy beam 31a is guided along a path parallel to the contour 25 (see Fig. 12). The second high-energy beam 31a selectively melts the material of the previous layer arrangement 13 and the further layer 29a only in an area near the contour 25, essentially in the molded body 10. 1 . The porosity in the (again) melted material of the molded body 10 1 near the side surfaces 14a, 14b is significantly reduced, and accordingly the roughness.

[0072] The second high-energy beam 31a is guided at a first safety distance 35a from a processing section 46 of the contour 25 of the melting area (see Fig. 12). The safety distance 35a is measured from the (central) beam axis of the high-energy beam 31a or the center of the corresponding spot on the layer surface of the further layer 29a to the contour 25 (in the processing section 46), perpendicular to the travel line. The first safety distance 35a here corresponds to half the diameter of the cross-sectional area of ​​the second high-energy beam 31a or its spot.

[0073] The second melt pool 32a penetrates the notch 30b and the powder 17 in the notch 30b that was not melted in process step II. By melting the powder 17 in the notch 30b that was not melted in process step II and the powder 17 of the molded body 10 that was melted in process step II (see Fig. 2) 1In the vicinity of the notch 30b, the notch 30b is reduced in size or leveled. Roughness caused by powder particles sintered in the area of ​​the notch 30b is also reduced, since the second high-energy beam 31a concentrates its energy more strongly on the melt pool 32a than the first high-energy beam. As a result, the roughness of the surface 15 of the molded body 10 can be reduced. 1 in the area of ​​the side surface 14b. The notch 30a is treated in a similar manner (not shown in detail).

[0074] Fig. 5 shows a molded body 10 n in a production chamber 11 in a second variant of the production process, which largely corresponds to the first variant of Fig. 1f; accordingly, only the essential differences are explained.

[0075] In the second variant of the molded body 10 11several, here three, further layers 29b, 29c, 29d are applied one after the other with steps I and II, and only after step II of the third further layer 29d does step II follow.

[0076] Fig. 5 shows, in a highly schematic manner, the three new layers 22b, 22c, 22d of powder 17, which are applied sequentially according to method step I to the previous layer arrangement 13 (existing at the time of application). Before the next new layer 22b, 22c, 22d is applied, the powder 17 in each of the new layers 22b, 22c, 22d is melted in the corresponding melting regions 23b, 23c, 23d by the first high-energy beam 24 according to method step II. The respective first melt pool 26b, 26c, 26d extends with the first melting depth 27 into the next lower layer, which is the uppermost layer 20a of the previous layer arrangement 13 (existing at this time) with the layers 12a, 12b, 12c, etc. in the production chamber 11.In each new layer 22b, 22c, 22d, the first high-energy beam 24 passes through the melting region 23b, 23c, 23d delimited by a contour 25 (indicated by a dashed line) in order to melt the powder 17 in the respective melting region 23b, 23c, 23d.

[0077] Fig. 6 shows the molded body 10 n in the production chamber 11 after melting the third melting region 23d by the first high-energy beam 24 according to the second variant of the production method. Near the side surfaces 14a, 14b, the porosity in the melted material of the molded body 10 is nin the further layers 29b, 29c, 29d. In each further layer 29b, 29c, 29d, indentations 30c, 30d, 30e, 30f, 30g, 30h are formed on the contour 25 of the respective melting area 23b, 23c, 23d by the profile of the respective melt pool 26b, 26c, 26d (cf. Fig. 5) during melting. These indentations 30c, 30d, 30e, 30f, 30g, 30h can lead to an undesirable roughness of the surface 15 of the molded body 10. 1 contribute.

[0078] Fig. 7 shows the molded body 10 n in the production chamber 11 with the notches 30c - 30h on the contours of the melting areas of the further layers 29b - 29d. Now, according to step III, the molded body 10 nirradiated with the second high-energy beam 31a along the travel line running parallel to the contour 25, which creates the second melt pool 32a. The second melt pool 32a surrounds the vapor capillary 34a. By (re-)melting the material, especially in the molded body 10", the porosity in the material near the side walls 14a, 14b is significantly reduced. In contrast to the embodiment of step III shown in Fig. 4, here the second melt pool 32a penetrates all three notches 30c, 30d, 30e of the additional three layers 29b, 29c, 29d added to the block simultaneously. As a result, the notches 30c, 30d, 30e of these layers 29b, 29c, 29d are jointly reduced or leveled, whereby the roughness of the surface 15 of the molded body 10 1 can be reduced. Fig. 8 shows the molded body 10 obtained after step III for the first and second variants of the manufacturing process 1 , 10 n in the production chamber 11. The molded bodies 101 , 10 n have a low porosity near the side surfaces 14a, 14b, and there are no notches on the side surfaces 14a, 14b of the molded body 10 1 The side surfaces 14a, 14b have been smoothed by the second high-energy beam 31a (see Fig. 4 and Fig. 7) using the method according to the invention.

[0079] Fig. 9 shows a schematic longitudinal section through a third embodiment of the molded body IO for a third variant of the method according to the invention 111 in the production chamber 11, similar to that shown in Fig. 7 for the second variant; only the essential differences are explained. The first side surface 14a of the molded body 10 nhas a first (lower) wall section 37a that runs parallel to direction 16 of the layer sequence. Above the first wall section 37a, a second wall section 37b of the first side surface 14a is to be manufactured, which is slightly inclined with respect to direction 16 of the layer sequence. For this purpose, when adding four additional layers (cf. layers 12d, 12e, current upper layer 20a of the current previous layer arrangement 13, current additional layer 29e) during the respective steps II, the melt pool of the first high-energy beam was shifted upwards and further outwards (here to the right). Step III is only applied when adding the fourth additional layer, cf. the currently drawn additional layer 29e, as illustrated in Fig. 9.

[0080] In the upper, second wall section 37b, notches 30i, 30j, 30k, 301 are formed in the uppermost four layers 12d, 12e, 20a, 29e, which are offset perpendicularly to the direction 16 of the layer sequence and which were previously produced by irradiation with a first high-energy beam 24 according to step II (cf. Fig. 5).

[0081] The upper ends of the notches 30i, 30j, 30k, 301 of the second wall section 37b lie on a straight line (shown in dashed lines in the figure) which is inclined to the direction 16 of the layer sequence of the molded body 10 111 A first inclination angle NWi is defined here as the angle between this inclined line and the direction 16 of the layer sequence. The notches 30i, 30j, 30k, 301 are increasingly separated from the molded body 10 111 from the outside, the further up they are arranged in direction 16 of the layer sequence.

[0082] According to step III, the further layer 29e is irradiated along the travel line parallel to the contour with a second high-energy beam 31b, which creates a second melt pool 32b that extends through the four uppermost layers 12d, 12e, 20a, 29e ("smoothing block" 48) – and even slightly beyond. The second high-energy beam 31b is irradiated from an overhang portion 44a of a machining portion of the contour of the melt region 23e of the current further layer 29e at a second safety distance 35b such that the outer edge of the melt pool 32b exactly touches the contour of the next layer 12f below the smoothing block 48 at its upper side. The position of the overhang portion 44a can be assigned to the upper end of the uppermost notch 301.

[0083] The second melt pool 32b completely penetrates the notch 30i, which borders the layer 12f, and the unmelted powder 17 arranged therein, and practically completely levels this notch 30i. The notches 30j, 30k, 301 following this notch 30i in the direction 16 of the layer sequence are penetrated by the second melt pool 32b in decreasing proportions. Accordingly, the notches 30j, 30k, 301 are leveled to a decreasing extent in the direction 16 of the layer sequence. Thus, the roughness of the second wall section 37b of the first side surface 37a of the molded body 10 n reduced to a lesser extent than in the first wall section 37a of the first side surface 14a of the shaped body 10 oriented in the direction of the layer sequence n .

[0084] Preferably, step III or the second high-energy beam 31b is subsequently applied after each additional layer, whereby as a result a complete leveling of the associated notches 30j, 30k, 30l can be achieved for all layers 12e, 20a, 29e located further up.

[0085] Fig. 10 shows a schematic longitudinal section through a fourth embodiment of the molded body 10 for a fourth variant of a manufacturing method according to the invention IV in the manufacturing chamber 11, similar to that shown in Fig. 9, with only the essential differences being explained.

[0086] The second wall section 37b of the first side surface 14a is to be manufactured here with a slightly larger inclination angle NW2. The notches 30m, 30n, 30o, 30p in the top four layers 12d, 12e, 20a, 29e of the smoothing block 48 are offset more significantly from each other transversely to the direction 16 of the layer sequence.

[0087] The second high-energy beam 31b is irradiated from an overhang portion 44b of the processing portion of the contour of the melting region 23f of the uppermost layer (current further layer) 29e of the smoothing block 48 at a third safety distance 35c such that the outer edge of the melt pool 32b exactly touches the contour of the next layer 12f below the smoothing block 48 at its upper side. Since the second inclination angle NW2 is greater than the first inclination angle NWi, the third safety distance 35c is also greater than the second safety distance 35b (see Fig. 9). The second melt pool 32b again penetrates the notch 30m, which borders the first wall section 37a, almost completely. The notches 30n, 30o, 30p following this notch 30m in direction 16 of the layer sequence are encompassed by the second melt pool 32b with portions which are each slightly smaller than in the case of the notch shown in Fig.9 shown third embodiment of the molded body 10. 111 In particular, the second melt pool 32b does not extend to the uppermost notch 30p in direction 16 of the layer sequence. Accordingly, the notches 30m, 30n, 30o, 30p are leveled to a lesser extent in direction 16 of the layer sequence than in the third embodiment of the molded body 10 shown in Figure 9. 111 , so that the roughness of the surface of the molded body 10 111 to a lesser extent. Therefore, step III or the second high-energy beam 31b is preferably applied after each additional layer.

[0088] Fig. 11 shows a schematic longitudinal section through a fifth embodiment of the molded body 10 for a fifth variant of the manufacturing method according to the invention. V in the production chamber 11, similar to that shown in Fig. 9; therefore, only the essential differences are explained.

[0089] The second wall section 37b of the first side surface 14a is to be manufactured here with a much larger inclination angle NW3. The first side surface 14a of the molded body 10 IV has a first wall section 37a, which runs parallel to the direction 16 of the layer sequence. Above the first wall section 37a, a second wall section 37b of the first side surface 14a is formed with prongs 39a, 39b, 39c, 39d offset perpendicularly to the direction 16 of the layer sequence in the top four layers 20b, 20c, 20d, 29e, wherein the upper ends of the prongs 39a, 39b, 39c, 39d lie on a straight line (shown in dashed lines in the figure) having a third angle of inclination NW3 with respect to the direction 16 of the layer sequence, which is greater than the angle of inclination NW2 in the third embodiment of the molded body 10. 111(see Fig. 10). The spikes 39a, 39b, 39c, 39d were previously created with a first high-energy beam 24 according to step II (see Fig. 5). The upper end of the uppermost spike 39a defines the position of a projection portion 45a of a contour of the melt region 23g of the current, further layer 29e.

[0090] The second wall section 37b has an inclination defined by the third inclination angle NW3, which is so great that irradiating the second high-energy beam 31b above the second wall section 37b would cause a second melt pool 32b to extend noticeably into the intended unmelted powder 17 below the second wall section 37b, even if the second high-energy beam were applied very close to the plane of the first wall section 37a. Therefore, the second high-energy beam 31b cannot be used effectively in the region of the second wall section 37b with such an inclination. Accordingly, such overhanging sections of the contour are skipped in the processing part in the fifth variant shown.

[0091] Fig. 12 shows a schematic plan view of a previous layer arrangement (see Fig. 13, reference 13) with a further layer 29a arranged thereon, with a predetermined melting region 23a delimited by a contour 25 (see also Fig. 3). The further layer 29a is to be solidified in the melting region 23a.

[0092] In step II, the melting region 23a is processed with a first high-energy beam as part of a thermal conduction welding process, effective for its entire surface (see also Fig. 3). Shown here in dashed lines is a hatching line 40 along which the first high-energy beam is moved to melt the powder 17 in the melting region 23a. The hatching line 40 is stored in an electronic control system (not shown). The first high-energy beam is also moved here along a contour travel line 41 parallel to the contour 25 of the melting region 23a in order to form the contour 25 of the melting region 23a continuously.In step II, the first high-energy beam is typically moved over the further layer 29a with a uniform line energy ELE at a uniform first melting depth EST (if the line energy or the melting depth is not uniform in step II, the maximum value occurring in step II can be used for ELE and EST).

[0093] In step III, a second high-energy beam is used. This beam is moved along a travel line 43, which generally runs parallel to contour 25; the (current) location of the second high-energy beam can be specified based on its (current) center point M on the surface of the further layer 29a. To account for specific features of the geometry of the molded body to be produced, the travel line is adjusted. For contour 25, a processing section 46 is first determined, which may comprise one or more sections of contour 25. In the present case, processing section 46 comprises two sections 46a and 46b of contour 25, which overall correspond to contour 25 with the omission of two projection sections 45b, 45c (see Fig. 14). The travel line 43 runs parallel to the two sections 46a, 46b of the machining part 46 of the contour 25. Accordingly, the travel line 43 also has two sections 43a, 43b.The ends of the projection parts 45b, 45c are indicated by dotted lines, see also Fig. 11. By the recess of the projection parts 45b, 45c for the travel line 43, melting of powder 17 under the projection parts 45b, 45c, which was not melted by the first high-energy beam 24 as intended, can be prevented by the second high-energy beam 31a.

[0094] The second high-energy beam (on the surface of the further layer 29e, i.e., with its "spot") has a cross-section 42, which is approximately circular in shape here. The cross-section has a spot diameter SPD and a center point M. The spot diameter SPD is a measure of the spot size of a high-energy beam, here the second high-energy beam. The spot diameter SPD can be determined, for example, according to the 86% criterion (86% of the energy output of the high-energy beam is within a circle with the spot diameter).

[0095] For section 43a and the areas of section 43b of travel line 43 running in the left-right direction in Fig. 12, a safety distance 35a of the spot (i.e., its center point M) from the contour 25 corresponds to half the diameter SPD of the spot. In a section of section 43b of travel line 43 running in the vertical direction in Fig. 12, the safety distance 35d is significantly greater, here corresponding to approximately 0.75 times the spot diameter SPD. This makes it possible to take into account that in the vertically running section of section 43b, contour 25 runs as an overhang part 44c (see Fig. 13). This makes it possible to prevent melting of powder 17 under the overhang part 44c of contour 25, which was not melted by the first high-energy beam 24 as intended, by the second high-energy beam 31a.

[0096] In step III, the second high-energy beam is typically moved over travel line 43 with a uniform second line energy ZLE at a uniform second melting depth ZST (if the line energy or the melting depth is not uniform in step III, the minimum value occurring in step II can be used for ZLE and ZST).

[0097] In the sixth variant shown, a factor FL=ZLE / ELE with FL=4 is selected. Furthermore, a factor FST=ZST / EST with FST=3 is selected.

[0098] Fig. 13 shows schematically a longitudinal section through the previous layer arrangement 13 and the further layer 29a along the (central) line A in Fig. 12. The further layer 29a is applied to the previous layer arrangement 13, in which the sixth embodiment of the molded body 10 VI is arranged. The molded body 10 VIIn particular, it has a side surface 14c inclined relative to the vertical direction 16 of the layer sequence, which extends under the overhang portion 44c of the contour 25; here, an increased safety distance should be applied (cf. Fig. 12); this can ensure that the melt pool of the second high-energy beam does not undesirably extend into the not yet melted powder. Under the processing portion 46a of the contour 25, which is opposite the overhang portion 44c, the molded body 10 is VI however, it is designed with a side surface 14d oriented in the vertical direction 16; here a smaller safety distance is sufficient (cf. Fig. 12).

[0099] Fig. 14 shows schematically a longitudinal section of the previous layer arrangement 13 and the further layer 29a along the (near edge) line B in Fig. 12. The molded body 10 VIhas a recess 47 beneath the projection 45b (the boundary of which is indicated by dotted lines) containing powder 17, which is not intended to be melted. The path of the second high-energy beam is interrupted in the area of ​​the projection 45b (see Fig. 12).

[0100] In summary, the invention relates to a manufacturing method for the layer-by-layer, additive manufacturing of a shaped body (10 1 ), whereby a previous layer arrangement is repeatedly supplemented by a further layer (29a) in the direction of a layer sequence, each with:

[0101] I. A new layer (22a) of a powder (17) is applied to the previous layer arrangement (13);

[0102] II. In a melting region (23a) having a contour (25) predetermined for the further layer (29a), the powder (17) of the new layer (22a) and at least a part of the uppermost layer of the previous layer arrangement (13) is melted with a first high-energy beam (24), in particular a laser beam or electron beam, characterized in that at least for some of the further layers (29a), the addition of the further layer (29a) further comprises:

[0103] III. A processing part (46) of the contour (25) is determined for the contour (25), and after step II, a second high-energy beam (31a), in particular a laser beam or high-energy beam, is moved along a travel line that runs parallel to the processing part (46), whereby the further layer (29a) and at least part of the uppermost layer of the previous layer arrangement (13) are melted along the travel line, wherein the second high-energy beam (31a) has a second melting depth (33a) greater than the first melting depth (EST) of the first high-energy beam.

[0104] The invention allows the surface roughness of the side surfaces of the molded body to be reduced. List of reference symbols

[0105] 10 I VI molded body

[0106] 11 Production chamber

[0107] 12a-f layers

[0108] 13 previous layer arrangement

[0109] 14a-d side surfaces

[0110] 15 Surface of the molded body

[0111] 16 Direction of the layer sequence

[0112] 17 powders

[0113] 18 lifting table

[0114] 19a, b side walls

[0115] 20a-d top layer (of the previous layer arrangement)

[0116] 21 order unit

[0117] 22a-d new location

[0118] 23a-g melting range

[0119] 24 first high-energy beam

[0120] 25 Contour

[0121] 26a-d first melt pool

[0122] 27 first melting depth

[0123] 28 Movement curve

[0124] 29a-e further layer

[0125] 30a-p notches

[0126] 31a, b second high-energy beam

[0127] 32a, b second melt pool

[0128] 33a second melting depth

[0129] 34a Steam capillary

[0130] 35a-d Safety distance

[0131] 37a first wall section

[0132] 37b second wall section

[0133] 39a-d points

[0134] 40 Hatching line (Step II)

[0135] 41 Contour line of travel (step II) 42 Cross section of the second high-energy beam

[0136] 43 driving line

[0137] 43a, b Sections of the route

[0138] 44a-c overhang parts

[0139] 45a-c cantilever parts

[0140] 46 Processing part

[0141] 46a, b Sections of the contour belonging to the machining part

[0142] 47 recess

[0143] 48 Smoothing block

[0144] B Width (of the weld)

[0145] EST first melting depth

[0146] M Center of the cross-sectional area of ​​the second high-energy beam

[0147] NWi inclination angle

[0148] NW2Inclination angle

[0149] NW3Inclination angle

[0150] SD layer thickness

[0151] SPD Diameter of the high-energy beam / spot

[0152] T Depth (of the weld)

[0153] ZST second melting depth

Claims

Patent claims Manufacturing process for layer-by-layer additive manufacturing of a shaped body (10 I VI ), wherein each existing layer arrangement (13) is repeatedly supplemented in the direction (16) of a layer sequence by a further layer (29a - 29e), wherein the supplementation of each further layer (29a - 29e) comprises the following steps: IV. A new layer (22a - 22d) of powder (17) is applied to the existing layer arrangement (13); V. In a melting zone (23a - 23f) predetermined for the next layer (29a - 29e), the powder (17) of the new layer (22a - 22d) is melted with a first high-energy beam (24), in particular a laser beam or electron beam, whereby at least a part of an uppermost layer (20a) of the previous layer arrangement (13) is also melted, wherein the first high-energy beam (24) has a first melting depth (27, EST) in the direction (16) of the layer sequence and a first line energy, and wherein the predetermined melting zone (23a - 23f) is bounded by a contour (25), characterized in that at least for some of the next layers (29a - 29e) the addition of the respective next layer (29a - 29e) further comprises the following step: VI. A machining part (46) of the contour (25) is determined for the contour (25) of the predetermined melting area (23a - 23f) of the further layer (29a - 29e), which is formed by one or more segments (46a, 46b) of the contour (25) or the entire contour (25). is, and after step II a second high-energy beam (31a, 31b), in particular a laser beam or high-energy beam, is moved along a travel line (43) which runs parallel to the processing part (46) of the contour (25), whereby along the travel line (43) the further layer (29a - 29e) and at least a part of the topmost layer (20a) of the previous layer arrangement (13) is melted, wherein the second high-energy beam (31a, 31b) has a second melting depth (33a, ZST) in the direction (16) of the layer sequence, wherein the second melting depth (33a, ZST) is greater by a factor FST than the first melting depth (27, EST), with FST>1.

2. Manufacturing process according to claim 1, characterized in that l <FST<10, bevorzugt 1,5<FST<8, besonders bevorzugt 2<FST<8, ganz besonders bevorzugt 4<FST<6.

3. Manufacturing method according to claim 1 or 2, characterized in that the second high-energy beam (31a, 31b) has a second line energy, wherein the second line energy is greater than the first line energy by a factor FL, with FL>1, in particular wherein a spot size of the second high-energy beam (31a, 31b) is equal to or greater than a spot size of the first high-energy beam (24).

4. Manufacturing method according to claim 3, characterized in that l <FL<20, bevorzugt l,3<FL<10, besonders bevorzugt 2<FL<8. A manufacturing method according to any one of the preceding claims, characterized in that a spot size of the second high-energy beam (31, 31b) is smaller than a spot size of the first high-energy beam (24), in particular wherein the second high-energy beam (31a, 31b) has a second line energy and the second line energy is equal to or less than the first line energy. A manufacturing method according to any one of claims 1 to 5, characterized in that step III is carried out when adding each further layer (29a - 29e) to the existing layer arrangement (13). A manufacturing method according to any one of claims 1 to 5, characterized in that step III is carried out when adding each nth further layer (12a - 12f) to the existing layer arrangement (13), where n > 2.Manufacturing method according to claim 7, characterized in that n is selected with n <ZST / SD, mit ZST: zweite Schmelztiefe (33a, ZST) und SD: Schichtdicke (SD) einer jeweiligen Schicht (12a - 12f), insbesondere wobei weiterhin auch gilt n> (ZST / SD)-1. Manufacturing process according to one of the preceding claims, characterized in that the melting in step II is carried out by heat conduction welding and the melting in step III is carried out by deep penetration welding. . Manufacturing process according to one of the preceding claims, characterized in that in step III a center point (M) of a cross-sectional area (42) of the second high-energy beam (31a, 31b) in the melting area (23a - 23f) of the further layer (29a - 29e) is moved at most to a predetermined safety distance (35a - 35c) from the processing part (46) of the contour (25) of the melting area (23a - 23f), in particular wherein the safety distance (35a - 35c) is at least one. half the diameter of the cross-sectional area (42) of the second high-energy beam (31a, 31b) corresponds to or at least half the width B of a weld seam produced by the second high-energy beam (31a, 31b). Manufacturing method according to claim 10, characterized in that for an overhang part (44a - 44c) of the processed part (46) of the contour (25), under which, in the direction (16) of the layer sequence in the previous layer arrangement (13) in the area up to the second melt depth (33a, ZST), at least locally unmelted powder (17) is located and at which an inclination angle (NWi - NW3) of the shaped body (10) I VI) with respect to the direction (16) of the layer sequence, a maximum first limiting angle GW1 is reached, a larger safety distance (35a - 35c) is selected than for a processed part (46) of the contour (25) under which, in the direction (16) of the layer sequence, in the previous layer arrangement (13) there is no unmelted powder (17) in the area up to the second melting depth (33a, ZST), wherein the first limiting angle GW1 is selected to be 30° or less, preferably 25° or less, particularly preferably 20° or less, and in particular wherein the safety distance (35a - 35c) increases with the size of the inclination angle (NWi - NW3).Manufacturing method according to one of the preceding claims, characterized in that the processing part (46) of the contour (25) recesses at least one projection part (45a - 45c) of the contour (25), under which, in the direction (16) of the layer sequence in the previous layer arrangement (13) in the area up to the second melting depth (33a, ZST), at least locally unmelted powder (17) is located and on which an inclination angle (NWi - NW3) of the molded body (10. I VI ) with respect to the direction (16) of the layer sequence is greater than a second limiting angle GW2, wherein the second limiting angle GW2 is chosen to be greater than 20°, preferably greater than 25°, particularly preferably greater than 30°. . Manufacturing method according to claim 12, characterized in that the processing part (46) of the contour (25) extends along the entire contour (25) except for the overhanging part (45a - 45c) of the contour (25). . Manufacturing method according to any of the preceding claims, characterized in that the processing part (46) of the contour (25) comprises at least 40%, preferably at least 60%, of the entire contour (25). . Manufacturing method according to any of the preceding claims, characterized in that the powder (17) contains copper, in particular with at least 50 wt% copper. . Manufacturing method according to any of the preceding claims, characterized in that the first high-energy beam (24) and / or the second high-energy beam (31a, 31b) is a laser beam and has a mean wavelength in a wavelength range of 500 nm to 560 nm. . Shaped body (10 I VI), produced by a manufacturing process according to one of the preceding claims.

Images