Hatch strategy during the process of solidifying construction material in an additive manufacturing process

Abstract

A method for providing control data for an additive manufacturing device has: a first step (S1) of accessing model data of at least one section of the object; a second step (S2) of generating at least one data model, the beam being moved along a trajectory, in each case without interrupting the supply of radiation energy to the layer, each of the trajectories having a number of first sub-trajectories (74a, 84) and a number of second sub-trajectories (75, 85), the angle formed between a sub-trajectory and the sub-trajectory following said sub-trajectory being greater than 90° and less than or equal to 180°, the beam being moved alternatingly along first and second sub-trajectories, a respective transition trajectory being specified between pairs of sub-trajectories, a value for the movement speed of the beam being specified for the transition trajectories, said value differing from the average value along the sub-trajectory connected to the respective transition trajectory; and a third step (S3) of providing control data for the manufacturing process.

Description

[0001] Hatch strategy for solidifying the build material in an additive manufacturing process

[0002] The present invention relates to a method and a device for providing control data for an additive manufacturing device, to a correspondingly adapted additive manufacturing method, a corresponding device for controlling energy input devices of an additive manufacturing device, a correspondingly adapted additive manufacturing device and a correspondingly adapted computer program.

[0003] Additive manufacturing devices and associated methods to which the invention relates are, in particular, those in which objects are produced layer by layer by solidifying a shapeless build-up material. Solidification can be achieved, for example, by supplying heat energy to the build-up material by irradiating it with electromagnetic radiation or particle radiation (e.g., laser sintering (SLS or DMLS) or laser melting or electron beam melting). For example, in laser sintering or laser melting, one or more laser beams are moved over those areas of a layer of the build-up material that correspond to the cross-section of the object to be produced in that layer, so that the build-up material is melted at these areas and, after cooling, is in a solidified state.

[0004] Fig. 7 shows the usual procedure for the additive manufacturing of objects by irradiating build material with electromagnetic radiation or particle radiation (e.g., laser sintering (SLS or DMLS) or laser melting or electron beam melting). In Fig. 7, an object cross-section 50 is shown in a

[0005] EP 2379 / PK / 31 .07.2025 The internal or core area 52 and a contour area 51 are subdivided, with the contour area 51 typically being assigned different parameters for energy input into the build-up material than the internal area 52. For example, the contour area 51 is scanned with a laser beam such that the laser beam is moved along the contour. The internal area 52 is usually solidified such that it is subdivided into sub-areas 53, which are typically approximately rectangular or square in shape and are therefore also referred to as "strips" or "squares". The internal area 52 is then scanned sub-area by sub-area with the laser beam.

[0006] As shown in Fig. 7, in each sub-area 53 the laser beam is moved along parallel paths (hatch lines) 54 across the build-up material, resulting in a hatched movement pattern when scanning each sub-area 53 with the laser beam. This process is also known as "hatching" in technical jargon. In Fig. 7, the direction of movement of the laser beam is illustrated by arrows. It can be seen that the directions of movement for adjacent hatch lines 54 are opposite to each other.

[0007] Fig. 8 illustrates how such a movement pattern of the laser beam can be achieved, showing only two hatch lines 64 and 65 of the area 53. For hatch line 64, the starting and ending points are designated 64A and 64E, respectively. For hatch line 65, the starting and ending points are designated 65A and 65E, respectively. In Fig. 8, the laser beam enters the area 53 at the top left and scans the build-up material in the area 53 along the upper hatch line 64. At the end 64E of the hatch line, i.e. when the laser beam has reached the edge of the sub-area 53, the laser beam is switched off and without radiation supply to the build-up material, the direction of movement of the laser beam within the reversal area 55 is changed, so that afterwards the laser beam can be moved along the second-highest hatch line 65 in the opposite direction of movement over the build-up material in the sub-area 53.Following this movement pattern, the entire sub-area 53 is then scanned, as illustrated in Fig. 7.

[0008] EP 2379 / PK / 31 .07.2025 Using this method known from the prior art, the inventors observed, particularly with metal powder as the build-up material, that increased material ejection (splashing) occurs at the beginning of a new hatch line, e.g., at the right end 65A of the second-highest hatch line 65 in Fig. 8, when the laser beam is switched on again. This can locally impair the quality of the manufactured object. In particular, the mechanical properties of the manufactured object may be deteriorated.

[0009] Therefore, the object of the present invention is to provide a method and a device by which the mechanical properties of objects produced by an additive manufacturing process can be improved.

[0010] The problem is solved by a computer-aided method according to claim 1, an additive manufacturing method according to claim 14, a device for providing control data according to claim 15, a device according to claim 16, an additive manufacturing device according to claim 17, and a computer program according to claim 18. Further developments of the invention are claimed in the dependent claims. In particular, a device according to the invention can also be further developed by features of the methods according to the invention described below or in the dependent claims, and vice versa. Furthermore, the features described in connection with a device according to the invention can also be used to further develop another device according to the invention, even if this is not explicitly stated.

[0011] A computer-aided method according to the invention for providing control data for an additive manufacturing device for producing a three-dimensional object, wherein the object is produced by means of the additive manufacturing device by applying a build material layer upon layer and solidifying the build material in a build plane by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by irradiating these locations with at least one beam according to a set of energy input parameter values ​​to effect sintering.

[0012] EP 2379 / PK / 31 .07.2025 or melting process along a number of trajectories, comprises: a first step (S1) of accessing computer-based model data of at least one section of the object to be manufactured, a second step (S2) of generating at least one data model of an area of ​​a build-up material layer to be solidified for the production of the at least one object section, which is assigned to an area of ​​a cross-section of the object, wherein the beam is moved along a trajectory at a speed without interrupting the supply of radiant energy to the layer, wherein each of the trajectories has a number of first sub-trajectories and a number of second sub-trajectories, wherein an angle between a first sub-trajectory and a second sub-trajectory following this first sub-trajectory is greater than 90°, preferably greater than 120°,is and is less than or equal to 180° and wherein the beam is moved alternately along first and second partial trajectories, wherein a transition trajectory is specified between a first partial trajectory and a second partial trajectory and between a second partial trajectory and a first partial trajectory, wherein a value of the beam's velocity is specified for the movement of the beam along a number of the transition trajectories, which differs from the average value of the beam's velocity along the first and second partial trajectories associated with the respective transition trajectory, and a third step (S3) in which control data are provided according to the at least one data model generated in the second step (S2) for the generation of a control data set for the additive manufacturing device.

[0013] By specifying a transition trajectory and by moving the beam along this transition trajectory, the first and second partial trajectories are shorter than a trajectory in the prior art: In the prior art, the beam is switched off during the transition from one hatch line to the next, so

[0014] EP 2379 / PK / 31 .07.2025 states that the first and second partial trajectories of the present invention each correspond to individual (total) trajectories in the prior art. These typically run from one end of a cross-section to the other. In contrast, the first and second partial trajectories according to the invention do not extend over the entire length of a cross-section. For this reason, the exposure times of the first and second partial trajectories are advantageously shorter than those of the prior art trajectories, which leads to an overall reduction in process time.

[0015] Additive manufacturing devices and methods to which the present invention relates are, in particular, those in which energy, in the form of electromagnetic radiation or particle radiation, is selectively supplied to a layer of a shapeless build material. The build plane (also referred to as the working plane) is a plane in which the top surface of the layer to which the energy is supplied lies. The energy supply can be effected, for example, using a laser or an electron beam source. The radiation supplied to the build material heats it, thereby causing a sintering or melting process. In particular, the present invention comprises laser sintering, laser melting, and electron beam melting devices, as well as the associated methods.

[0016] Of particular advantage is an application of the invention in connection with additive manufacturing processes and devices in which a metallic or at least metal-containing build-up material is used, for example a metal powder or metal alloy powder.

[0017] It should be noted here that not only one object, but also several objects can be produced simultaneously using an additive manufacturing device according to the invention. When the present application refers to the production of one object, it is understood that the respective description also applies equally to additive manufacturing processes and devices in which several objects are produced simultaneously.

[0018] The control data set (often also referred to as the control instruction set) is considered here to be a sequence of instructions, layers of the build material one after the other.

[0019] EP 2379 / PK / 31 .07.2025 to apply and to scan areas of the respective layers corresponding to the cross-section of an object to be produced with radiation in order to solidify the build-up material.

[0020] In detail, a control data set is based on a computer-based model of the object(s) to be manufactured, preferably a CAD model. The control data set specifies, for each layer during manufacturing, the locations where solidification of the build material is to be achieved through radiation application, and optionally also the layer thickness. Furthermore, a control data set often contains fixture-specific information, such as the position and orientation of the objects within the additive manufacturing fixture. Typically, the control data set contains all the data required to control the energy input device, i.e., the device that comprises the number of radiation sources and the associated number of beam deflection devices. This allows, among other things, the determination of the radiation power in the beam and / or the beam's traverse speed across the build material and / or an irradiation pattern.

[0021] It should be noted that the diameter of a beam does not necessarily have to be very small, especially if the radiation strikes the build-up material at an angle or if radiation is used that is intentionally designed to cover a larger area when striking the build-up material.

[0022] The control data set can be considered the entirety of all control data specified for controlling the manufacturing process in an additive manufacturing device. The control data relating to a single layer are usually referred to as the layer data set. In the present application, it is specifically assumed that a layer data set contains a data model of the areas of an object's cross-section to be solidified during the manufacturing process. Such a data model is obtained from computer-based model data of the object to be manufactured, in particular a CAD model of the object to be manufactured, by dividing the CAD model into layers (referred to in technical jargon as slicing). However, it is also conceivable to use a

[0023] EP 2379 / PK / 31 .07.2025: Extracting a two-dimensional representation of the object cross-section to be solidified in a layer using one or more beams from the computer-based model data of the object by other means. The layer data set specifies locations corresponding to an object cross-section that are to be solidified in the associated build-up material layer. Furthermore, it may contain additional information regarding the production of the object cross-section, in particular the temporal sequence in which locations corresponding to an object cross-section are to be solidified by specifying beam motion vectors in the build-up plane. The specified motion vectors thus cause the beam to move along a trajectory in the build-up plane. For example, a motion vector could be specified by stating two pairs of coordinates, e.g., (x1, y1, x2, y2).This would specify that the beam must move from point (x1, y1) in the build plane to point (x2, y2) in the build plane. Furthermore, irradiation parameter values, such as the diameter or the traverse speed of the beam impacting the build material, can also be specified. It should be emphasized that there are also special cases in which a layer data set does not refer to a complete object cross-section, but only to a part of it.

[0024] A trajectory is understood here as a line in the build plane along which a beam is moved without interrupting the supply of radiant energy to the build material layer. According to the invention, such a defined trajectory has a plurality of segments or sub-trajectories. A distinction is made between first and second sub-trajectories, which preferably have a constant angle to each other and are preferably parallel to each other, and transition trajectories, which connect a first sub-trajectory with a second, preferably adjacent, sub-trajectory, or connect a second sub-trajectory with a first, preferably adjacent, sub-trajectory. This means that a beam can, for example, meander along a trajectory by alternately traversing a first and second sub-trajectory and moving along the transition trajectories in between.An angle between a first and a second partial trajectory is defined in such a way that the size of the angle is determined not only by the position of the partial trajectories in the construction plane, but also by the direction of movement of the beam.

[0025] EP 2379 / PK / 31 .07.2025 along the two partial trajectories. In other words, the angle corresponds to the angle by which the direction of motion must be rotated when transitioning from the first to the second partial trajectory (or vice versa). Two parallel partial trajectories scanned in opposite directions thus have an angle of 180° to each other. If they were scanned in the same direction in the plane, the angle would be 0°.

[0026] Although the first and second partial trajectories are generally essentially parallel to each other, corresponding to the hatch lines shown in Fig. 8, there are special cases where the angle is less than 180°, i.e., closer to 120° or even 90° than to 180°. Since the partial trajectories are not parallel in the latter case, energy is not supplied homogeneously to the build material. However, this is harmless, for example, in the case of thin walls that are scanned along the wall's length. The non-parallelism reduces the scanning time for a section to be hatched. Angles between 90° and 180° are also conceivable, for example, for partial trajectories that run along or parallel to the contour of an object, such as in so-called "onion hatching."

[0027] Preferably, at least one first and one second partial trajectory and one transition trajectory, and especially preferably all first and second partial trajectories and all transition trajectories, lie completely within the area of ​​the cross-section of the object to be solidified.

[0028] Preferably, at least one transition trajectory, and especially preferably all transition trajectories, intersects an edge of the area of ​​the cross-section of the object to be solidified.

[0029] The computer-based model data could, for example, be a model of the object section to be manufactured, which exists, for instance, as a CAD model or converted into the STL format, and does not yet contain any information about the decomposition into layers for layer-by-layer manufacturing. The model data could also exist in a GML (Generative Modeling Language) description. Alternatively, the computer-based model data could be...

[0030] EP 2379 / PK / 31 .07.2025 concerns a number of layer data sets, each containing a data model of an area of ​​a build-up material layer to be selectively solidified during production, corresponding to a cross-section of the object section. It should be noted here that in the present application, the term 'number' is always to be understood as 'one or more'. Furthermore, it should be noted that the object section need not necessarily refer only to a part of the object to be produced, but can also comprise the entire object to be produced.

[0031] Access to the model data can be achieved by reading the model data from memory or receiving it via a network. The model data for the entire object section does not necessarily have to be read in all at once. It is also possible to have a larger time interval between accesses to parts of the model data. For example, parts of the model data could be read in as needed during a manufacturing process of the object section from memory (which can also be accessed, for example, by the additive manufacturing device) or via a network, and a generated data model could then be integrated into the control data set during the manufacturing process. Thus, based on the method according to the invention, an additive manufacturing device can itself modify the control data set for its operation.

[0032] If the model data accessed in the first step already contains a number of layer data records, then the creation of at least one data model in the second step can consist of modifying a data model of an existing assembly material layer within the model data. Otherwise, a data model of an assembly material layer (or a part thereof) can be created for the first time in the second step.

[0033] If the data model generated in the second step specifies scanning with at least one beam, this means that during the scanning process, at least one beam acts on the build-up material in such a way that a solidification of at least one uppermost layer of the build-up material is caused, which

[0034] EP 2379 / PK / 31 .07.2025 The building material is therefore not merely preheated or reheated, but at least partially melted.

[0035] During the solidification of the build material along a trajectory, the energy input from the beam causes the material to partially or completely melt as it scans, causing the components of the build material (e.g., powder grains) to bond together. After cooling, the build material then exists as a solid.

[0036] It should be noted that there may be build-up materials, such as alloys, for which a melting range, rather than a single, definite melting point, is defined. In principle, in such a case, one can speak of partial melting as soon as the solidus temperature, i.e., the lower limit of the melting range, is exceeded. However, the present invention is preferably applicable to cases in which the build-up material is completely melted, i.e., when the liquidus temperature, or the upper limit of the melting range, is exceeded.

[0037] Since the transitions between partial (i.e., superficial in the case of powder particles) melting (e.g., liquid-phase sintering) and complete melting are fluid, the terms sintering and melting are used synonymously in the present application. In any case, the present invention can be used particularly in additive manufacturing processes in which the complete melting of the build material occurs when a beam is directed onto the build material, especially by means of a keyhole welding process.

[0038] When a beam is moved along a trajectory in the build plane across the build material, energy is transferred to the build material along the linear trajectory such that the resulting melt track in the build material has a non-zero width, depending on the extent of the beam impact area on the build material. In contrast to the melt track, the trajectory is a line of zero width, resulting from the specified movement of the beam in the build plane.

[0039] EP 2379 / PK / 31 .07.2025 The length of a solidification track (melt track) corresponds, for example, in hatching, to the width of a (often strip-shaped or rectangular) section of a cross-section of the object to be manufactured that is to be solidified. If an object cross-section or a (often rectangular) section thereof to be solidified is solidified by means of a jet in the form of a hatching pattern, the first and second partial trajectories corresponding to the hatching lines are also referred to as "hatch lines".

[0040] Preferably, the first and second partial trajectories run essentially parallel to each other, e.g. for at least 80%, preferably at least 95%, of the length of the shorter of the two adjacent partial trajectories.

[0041] When the invention is applied to the consolidation of strip-shaped or square sub-areas, where the first and second partial trajectories are hatch lines when scanning such sub-areas, then the first and second partial trajectories have the same lengths. Otherwise, particularly if the areas to be consolidated are not rectangular or the partial trajectories do not run perpendicular to the edges of a sub-area, the hatch lines can also have different lengths.

[0042] The direction of scanning along a trajectory or partial trajectory generally runs from the start point to the end point, with the start point being the first location scanned and the end point being the last location scanned. To avoid misunderstandings, it should be emphasized that when defining a start or end point, any unwanted swivel movements of the beam around the start or end point are disregarded.

[0043] It should also be noted that the tax data provided for the generation of a tax data record can consist, on the one hand, of the data model itself generated in the second step, and on the other hand, the data model can also be further prepared according to any format requirements for integration into the tax data record.

[0044] EP 2379 / PK / 31.07.2025 The inventors found that the process quality in the manufacture of objects can be improved, in particular porosity reduced, and at the same time the build rate of the manufacturing process can be increased if the radiation supply to the build material is not interrupted along the transition trajectories. In order to avoid an inhomogeneous distribution of the molten build material within the (partial) area to be solidified or irregularities (e.g., superimpositions) after solidification, the value of the movement velocity along the transition trajectories is selected to be different, preferably lower, than the average value (e.g., the arithmetic mean) of the movement velocity along the first and second partial trajectories, which are generally the actual hatch lines.In particular, a lower value is advantageous because it allows for a more homogeneous distribution of the molten build-up material along the transition trajectory.

[0045] Preferably, for the movement of the beam along a number of transition trajectories, a value for the speed of movement is specified that is less than the average value or the minimum value of the speed of movement of the beam along the first and second sub-trajectories associated with the respective transition trajectory.

[0046] It is further preferred that for the movement of the beam along a number of transition trajectories, a value for the speed of movement is specified which is greater than the average value or the maximum value of the speed of movement of the beam along the first and second sub-trajectories associated with the respective transition trajectory.

[0047] In general, the speed of movement will fluctuate only slightly when moving along the first and second partial trajectories, so that the mean speed of movement (e.g. the arithmetic mean) and the maximum speed of movement will differ only slightly from each other in practice.

[0048] EP 2379 / PK / 31 .07.2025 A further computer-aided method according to the invention for providing control data for an additive manufacturing device for producing a three-dimensional object, wherein the object is produced by means of the additive manufacturing device by applying a build material layer upon layer and solidifying the build material in a build plane by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by scanning these locations with at least one beam according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, comprises the steps: a first step of accessing computer-based model data of at least one section of the object to be produced,a second step of generating at least one data model of an area of ​​a build-up material layer to be solidified for the production of at least one object section, which is assigned to an area of ​​a cross-section of the object, wherein the beam is moved along a trajectory at a velocity without interrupting the supply of radiation energy to the layer, wherein each of the trajectories has a number of first sub-trajectories and a number of second sub-trajectories, wherein an angle between a first sub-trajectory and a second sub-trajectory following this first sub-trajectory is greater than 90°, preferably greater than 120°, and less than or equal to 180°, and wherein the beam is moved alternately along first and second sub-trajectories.wherein a transition trajectory is specified between a first partial trajectory and a second partial trajectory and between a second partial trajectory and a first partial trajectory, wherein a value of radiation intensity is specified for the movement of the beam along a number of the transition trajectories, which differs from the average value or the maximum value of the radiation intensity when the beam moves along the first and second partial trajectories associated with the respective transition trajectory, and,

[0049] EP 2379 / PK / 31 .07.2025 a third step in which control data is provided according to at least one data model for generating a control data set for the additive manufacturing device, based on the data model generated in the second step.

[0050] Preferably, in the second step of generating at least one data model for one of the number of transition trajectories, a value for the radiation intensity is specified that is greater than the average value or the maximum value of the radiation intensity when the beam moves along the first and second sub-trajectories associated with the respective transition trajectory.

[0051] In the second step of generating at least one data model for one of the number of transition trajectories, it is further preferred that a value for the radiation intensity is specified which is lower than the average value or the minimum value of the radiation intensity when the beam moves along the first and second sub-trajectories associated with the respective transition trajectory.

[0052] Particularly preferably, in the second step of generating at least one data model along the transition trajectory, a value for the radiation intensity is specified that does not fall below a minimum value. This minimum value for the radiation intensity specified along the transition trajectory is preferably defined on the basis of an average or maximum value of the radiation intensity along the first and second partial trajectories and is at least 20%, preferably at least 50%, particularly preferably at least 70% and / or at most 95%, preferably at most 85%, particularly preferably at most 80% of an average or maximum value of the radiation intensity along the first and second partial trajectories.

[0053] In general, the radiation intensity will fluctuate only slightly during movement along the first and second partial trajectories, so that in practice the mean value of the radiation intensity (e.g. the arithmetic mean) and the maximum value of the radiation intensity will differ only slightly from each other.

[0054] EP 2379 / PK / 31 .07.2025 By ensuring that a minimum value for the radiation intensity along the transition trajectory is not undercut, it is possible to obtain a melt track or melt pool as the beam moves along the transition trajectory and the first and second sub-trajectories associated with the transition trajectory. Obtaining a melt pool or melt track means that at least partial, preferably complete, melting of the build-up material occurs at adjacent locations.

[0055] Several parameters can be used to adjust the radiation intensity, either individually or in combination. For example, reducing the beam focus increases the radiation intensity, provided all other parameters remain constant. Conversely, reducing the power of the radiation source (e.g., the laser power), increasing the beam focus (defocusing), or increasing the beam speed decreases the radiation intensity. Increasing the beam focus (defocusing) can be advantageous because it reduces the depth of the melt pool.

[0056] The inventive method is particularly advantageous when a deep penetration welding process occurs when the radiation acts on the build material. One explanation for this is as follows:

[0057] In selective laser sintering (SLS), also known as laser melting, the build material of metal powder is melted using a deep penetration welding process. This process generates such high temperatures within the material that vaporization occurs, causing the radiation to penetrate a vapor capillary at the material surface. Multiple reflections at the edges of the vapor capillary allow for increased energy transfer into the material. This temporarily formed vapor capillary is also referred to as a "keyhole." If the radiation intensity is increased again after an interruption of the melting process during scanning, a keyhole must first be formed to ensure a stable melting process.

[0058] This creates a melt pool that extends to a greater depth than the

[0059] EP 2379 / PK / 31 .07.2025 Layer thickness of the last applied powder layer. For example, the melt pool extends to a depth two to three times the layer thickness. In particular, this means that material must first be vaporized, which can lead to increased spattering. At the same time, a pore, i.e., a cavity, is left at the point of keyhole formation, which impairs the mechanical properties.

[0060] The invention, in all its embodiments, is not limited to the transition from a single first partial trajectory to a single second partial trajectory. Rather, within an object section, the described procedure can be used for a plurality of transitions, preferably for all transitions, from first partial trajectories to subsequent second partial trajectories and vice versa. In particular, for all transitions within an entire object cross-section or a sub-section thereof, or even within an entire object to be manufactured, the radiation intensity values ​​along the transition trajectories can be selected in the same way. In other words, a transition from a first partial trajectory to a second partial trajectory and vice versa always occurs in the same manner.

[0061] Preferably, in the method, control data for the production of a three-dimensional object from metal-based build material are provided, and the radiation intensity specified for scanning the transition trajectory is set such that a deep welding process takes place when the radiation acts on the build material.

[0062] The type of welding process can be determined, for example, by observing the weld pool with a camera (optical, IR, UV), by analyzing the radiation emitted by the weld pool, or by analyzing test objects produced in preliminary trials. Emissions caused by the vapor capillary generated during the weld pool process, such as spatter or jets, as well as metal vapor, can be used as criteria for the presence of a deep penetration welding process. Another criterion is the aspect ratio of the weld pool (width of the weld pool parallel to the build plane in relation to its depth, i.e.,

[0063] EP 2379 / PK / 31 .07.2025 (perpendicular to the plane of construction), which should be below 1 during the deep penetration welding process, or the surface temperature of the build-up material. If the latter is below the evaporation point of one or all components of the build-up material, then the "keyhole" required for the deep penetration welding process cannot form. As a rule, a deep penetration welding process occurs with steel materials when the applied power per area is 1 MW / cm². 2The investigation of the type of melting process can also be carried out by observing the solidified build-up material in a solidification track. Such an investigation can be performed, for example, using a "speed camera," where the dynamics of the solidification are observed. Alternatively, the solidified build-up material can be observed, for example, using laser Z-scanner profile sensors. In this case, the depth and / or width of the melt track is measured, for example optically, so that the type of melting process (e.g., deep penetration welding) can be reconstructed based on the topology or morphology of the solidified material.

[0064] Preferably, a monotone decrease and / or a monotone increase of an amount of the motion velocity or a constant amount of the motion velocity is specified for the movement of the beam along the transition trajectories.

[0065] Again, the term "monotonic" here is meant to express that the change (decrease or increase) in the speed of motion during the movement of the beam can certainly be continuous, but it does not necessarily have to be; for example, the speed can remain constant at times. Unlike a strictly monotonic decrease or increase, the decrease or increase can therefore also occur in steps. When specifying a constant speed of motion along the transition trajectories, the speed of motion remains unchanged while moving along these trajectories.

[0066] Preferably, the beam's velocity is increased, at least along the transition trajectory, to achieve an overall lower beam energy density in the transition trajectory region. This approach avoids

[0067] EP 2379 / PK / 31 .07.2025 prevents excessive build-up material from melting outside the (partial) area to be solidified and simultaneously allows the build rate to be increased without compromising component quality. To achieve an increased flow rate in the transition trajectory, the following possibilities arise, for example: a) The flow rate of the jet can be increased (continuously or in a number of stages) along the entire transition trajectory, optionally starting at the endpoint of the preceding first partial trajectory, and then decreased again from the starting point of the subsequent second partial trajectory.b) The speed of the beam can be increased (continuously or in a number of steps) towards the endpoint of the preceding first partial trajectory, kept constant along the transition trajectory, and then decreased again from the starting point of the subsequent second partial trajectory. c) The speed of the beam can be increased towards the endpoint of the preceding first partial trajectory and then decreased monotonically along the entire transition trajectory. Optionally, the speed of the beam can be decreased even further from the starting point of the subsequent second partial trajectory.

[0068] It is further preferred that the speed of the beam is reduced, at least along the transition trajectory. This makes it easier to implement changes (increases and decreases) in the speed of movement along the transition trajectory. To achieve a reduced speed of movement in the transition trajectory, the following possibilities, for example, are possible: a) One can reduce the speed of movement along the entire transition trajectory, optionally starting at the endpoint of the preceding first sub-trajectory.

[0069] EP 2379 / PK / 31 .07.2025 a) The beam's speed can be reduced in one direction and then increased again from the starting point of the subsequent second partial trajectory. b) The beam's speed can be reduced towards the endpoint of the preceding first partial trajectory, kept constant along the transition trajectory, and then increased again from the starting point of the subsequent second partial trajectory. c) The beam's speed can be reduced towards the endpoint of the preceding first partial trajectory and then monotonically increased again along the entire transition trajectory. Optionally, the beam's speed can be increased even further from the starting point of the subsequent second partial trajectory.

[0070] Preferably, for the successive movement of the beam along a first partial trajectory, along a transition trajectory and along a second partial trajectory, the magnitude of the speed of movement is specified such that the magnitude of the speed of movement decreases monotonically during the movement along a segment of the first partial trajectory and / or along a segment of the transition trajectory and subsequently increases monotonically during the movement along a segment of the transition trajectory and / or along a segment of the second partial trajectory.

[0071] This approach allows the minimum velocity to be placed in the first or second partial trajectory, or, in particular, in the transition trajectory. The segment of the transition trajectory in which the velocity increases monotonically is distinct from the segment in which the velocity decreases monotonically. Preferably, the segment of the first partial trajectory includes the endpoint of the first partial trajectory or at least borders upon it. More preferably, the segment of the second partial trajectory includes the starting point of the second partial trajectory or at least borders upon it.

[0072] EP 2379 / PK / 31 .07.2025 Preferably, the radiation power is reduced simultaneously or with temporal overlap with the reduction of the movement speed. Further preferably, the radiation power is increased simultaneously or with temporal overlap with the increase of the movement speed. The movement speed and the radiation power are reduced or increased in such a way that the radiation energy density (as defined below) does not exceed or falls below a certain value, or such that the radiation energy density lies within an interval at least along a portion of the transition trajectory. E.g.The beam energy density along at least one part of the transition trajectory is at least 50%, preferably at least 70%, particularly preferably at least 80% and / or at most 150%, preferably at most 120%, particularly preferably at most 95% of an average value or a maximum value of the beam energy density in the first or in the second part of the trajectory.

[0073] Preferably, the speed of movement and the radiation power are gradually reduced during movement along a segment of the first partial trajectory and / or along a segment of the transition trajectory. Alternatively or additionally, preferably after the reduction, the speed of movement and the radiation power are gradually increased during movement of the beam along a segment of the transition trajectory and / or along a segment of the second partial trajectory. Particularly preferably, the speed of movement is reduced or increased with a smaller number of steps than the radiation power.

[0074] Furthermore, preferably, at the endpoint of the first partial trajectory, the velocity of motion has a value that is less than or equal to 75% of the mean value of the velocity of motion specified for the motion along the first partial trajectory, and / or at the starting point of the second partial trajectory, the velocity of motion has a value that is less than or equal to 85% of the mean value of the velocity of motion specified for the motion along the second partial trajectory.

[0075] EP 2379 / PK / 31 .07.2025 Preferably, the respective mean is defined as the arithmetic mean.

[0076] Furthermore, the distance along which the magnitude of the speed of motion increases monotonically is preferred to be longer than the distance along which the magnitude of the speed of motion decreases monotonically.

[0077] In other words, the magnitude of the motion should preferably increase again more quickly than it was previously decreased. In other words, the increase in the magnitude of the motion from its minimum should occur more rapidly than the decrease in the magnitude of the motion down to its minimum. Thus, the behavior of the magnitude of the motion over time is preferably asymmetric with respect to the time at which the minimum value of the radiation intensity is reached. Preferably, the decrease and increase in the magnitude of the motion occur in steps, wherein the number of steps by which the decrease is achieved is greater than the number of steps by which the increase is achieved, and the time period within which the stepwise decrease is achieved is greater than the time period within which the stepwise increase is achieved.

[0078] It is further preferred that a predetermined time interval (“cycle”) elapses between one stage and the next; that is, that the speed of movement within a stage is kept constant for a predetermined time interval. This applies to both a reduction and an increase in the speed of movement (correspondingly to a stepwise change in radiation intensity). The length of the path over which the beam moves during this predetermined time interval corresponds to the product of this time interval and the speed of movement. A reduction in the speed of movement is particularly advantageous for a predetermined time interval because it also reduces the spatial distance over which the speed of movement extends; that is, the speed of movement remains constant over a shorter spatial distance within a stage.This is advantageous because the change (reduction and increase) in speed of movement can occur on a smaller scale.

[0079] EP 2379 / PK / 31 .07.2025 Preferably, for the movement along the transition trajectories, a movement speed is specified which at each point of the transition trajectory is a value that is at least 20%, preferably at least 30%, particularly preferably 40% and / or at most 80%, preferably 70%, particularly preferably 60% of the value of the movement speed at the endpoint of the temporally preceding first or second partial trajectory.

[0080] Preferably, for the movement of the beam along a number of transition trajectories, a value for the beam energy density is specified that differs from the average value along the first and second trajectories associated with the respective transition trajectory.

[0081] The radiation energy density, hereinafter referred to as EB, is defined by the relationship (1 )

[0082] EB = PL / V (1 ).

[0083] Here, PL denotes the laser power and v the movement speed of the laser focus or the beam impact area across the build plane. The definition of beam energy density is identical to the definition of another quantity known in the field of welding, namely the linear energy.

[0084] Since the speed of a digitally controlled beam deflection device can only change in steps whose length is determined by the time interval (e.g., 10 ps), a beam energy density, defined similarly to the line energy, can also be visualized as energy transferred along a distance into the build material, which the beam travels within the build plane within the time interval or within a multiple of the time interval. Strictly speaking, the beam energy density defined in this way is a line density, and it has the unit [J / mm].

[0085] Alternatively, the radiation energy density can also be defined as the energy density EBF per unit area:

[0086] EP 2379 / PK / 31.07.2025 EBF = PL / (V'dHatch) (2).

[0087] Here, dHatch denotes the distance between two adjacent first and second partial trajectories. The presence of dHatch in the formula can be explained by the fact that when uniformly scanning a build-up material area with the laser ("hatching"), the beam width essentially corresponds to dHatch, or at least is correlated with it. Thus, the beam energy density EBF is the energy that is transferred into the build-up material within a time interval or within multiples of a time interval over an area swept by the radiation within that time interval. Since dHatch generally does not change during a change in beam power (e.g., laser power) and movement speed, the beam energy density EBF, defined with respect to the area, varies in the same way as the beam energy density EB when the beam power (e.g., laser power) and movement speed are changed.

[0088] Since, strictly speaking, it depends on the energy introduced into the build-up material per unit volume, the beam energy density can also be defined in relation to the volume as follows:

[0089] EßV = PL / (v ■ dHatch ■ dlayer) (3).

[0090] Here, diayer refers to the thickness of the uppermost build-up material layer, which roughly approximates the depth of the melt pool. Since diayer generally remains constant during changes in beam power (e.g., laser power) and movement speed, the beam energy density EBV, defined per unit volume, varies in the same way as the beam energy densities EB and EBF.

[0091] In particular, it is preferred that a value be specified for the movement of the beam along a number of transition trajectories which is less than an average value or a minimum value of the beam energy density along the first and second sub-trajectories associated with the respective transition trajectory.

[0092] EP 2379 / PK / 31 .07.2025 It is further preferred that for the movement of the beam along a number of transition trajectories a value of the beam energy density is specified which is greater than an average value or a maximum value of the radiation intensity along the first and second sub-trajectories associated with the respective transition trajectory.

[0093] It is further preferred that for the movement of the beam along the number of transition trajectories a monotonic change in the beam energy density or a constant beam energy density is specified at least along a section of the respective transition trajectory.

[0094] The term "monotonic" here is intended to express that the change, i.e., the decrease or increase in the beam energy density during the beam's movement, can certainly be continuous, but it does not necessarily have to be; for example, the beam energy density can remain constant at times. Unlike a strictly monotonic decrease or increase, the decrease or increase can therefore also occur in steps. When specifying a constant beam energy density along the transition trajectories, the beam energy density remains unchanged during movement along these trajectories.

[0095] To achieve a reduced beam energy density in the transition trajectory, the following possibilities arise, for example: a) The beam energy density can be reduced along the entire transition trajectory, optionally starting at the endpoint of the preceding first sub-trajectory, and then increased again from the starting point of the subsequent second sub-trajectory. b) The beam energy density can be reduced towards the endpoint of the preceding first sub-trajectory, the radiation intensity can be kept constant along the transition trajectory, and the beam energy density can be increased from the

[0096] EP 2379 / PK / 31 .07.2025 The starting point of the subsequent second partial trajectory can be increased again. c) The beam energy density can be allowed to decrease towards the endpoint of the preceding first partial trajectory and then increase monotonically again along the entire transition trajectory. Optionally, the beam energy density can be allowed to increase even further from the starting point of the subsequent second partial trajectory.

[0097] Furthermore, the following possibilities, for example, open up to achieve an increased beam energy density in the transition trajectory: a) One can increase the beam energy density along the entire transition trajectory, optionally already towards the endpoint of the preceding first sub-trajectory, in order to allow it to decrease again from the starting point of the subsequent second sub-trajectory. b) One can increase the beam energy density towards the endpoint of the preceding first sub-trajectory, keep the radiation intensity constant along the transition trajectory, and allow the beam energy density to decrease again from the starting point of the subsequent second sub-trajectory. c) One can increase the beam energy density towards the endpoint of the preceding first sub-trajectory and allow the beam energy density to decrease monotonically again along the entire transition trajectory.Optionally, the beam energy density can be further reduced from the starting point of the subsequent second partial trajectory.

[0098] In particular, a monotonic decrease or increase in beam energy density or a constant beam energy density can only be specified for a portion of the transition trajectory.

[0099] Preferably, the radiation energy density is changed so that it does not exceed or fall below a certain amount, or that it is within an interval.

[0100] EP 2379 / PK / 31 .07.2025 remains valid. This applies regardless of whether the beam energy density is reduced or increased. For example, a beam energy density along at least one section of the transition trajectory is at least 50%, preferably 70%, particularly preferably 80% and / or at most 150%, preferably at most 120%, particularly preferably at most 95% of an average or maximum value of the beam energy density in the first or second partial trajectory.

[0101] Preferably, for the successive movement of the beam along a first partial trajectory, along a transition trajectory and along a second partial trajectory, the value of the beam energy density is specified such that the value of the beam energy density decreases monotonically during the movement along a segment of the first partial trajectory and / or along a segment of the transition trajectory and subsequently increases monotonically during the movement along a segment of the transition trajectory and / or along a segment of the second partial trajectory.

[0102] This approach allows the minimum of the beam energy density to be placed in the first partial trajectory, the second partial trajectory, or, more specifically, in the transition trajectory. The segment of the transition trajectory in which the beam energy density increases monotonically is distinct from the segment in which the beam energy density decreases monotonically. Preferably, the segment of the first partial trajectory includes the endpoint of the first partial trajectory or at least borders upon it. More preferably, the segment of the second partial trajectory includes the starting point of the second partial trajectory or at least borders upon it.

[0103] Preferably, the beam energy density is gradually reduced during the beam's movement along a segment of the first partial trajectory and / or along a segment of the transition trajectory. Alternatively or additionally, the beam energy is gradually increased during the beam's movement along a segment of the second partial trajectory and / or along a segment of the transition trajectory.

[0104] EP 2379 / PK / 31 .07.2025 Preferably, the section along which the radiation energy density increases monotonically is longer than the section along which the radiation energy density decreases monotonically.

[0105] Preferably, the value of the radiation energy density should be increased more slowly than it was previously decreased. In other words, the increase in the value of the radiation energy density from its minimum should be slower than the decrease in the value of the radiation energy density to its minimum. The behavior of the value of the radiation energy density over time is therefore preferably asymmetric with respect to the time at which the minimum value of the radiation energy density is reached. Preferably, the decrease and increase of the value of the radiation energy density occur in steps, with the number of steps used for the decrease being particularly preferred, being smaller than the number of steps used for the increase. Preferably, the step size is also larger when decreasing the radiation energy density than when increasing it. Furthermore, it is preferred that a predetermined time interval ("cycle") elapses between each step; i.e.,The beam energy density within a stage is kept constant for a predetermined time interval. This applies to both reductions and increases in beam energy density (correspondingly, to a decreasing or increasing beam energy density stage). The length of the path over which the beam travels within this predetermined time interval is determined by this time interval and the speed (velocity) at which the beam travels within this time interval.

[0106] The described procedure prevents the build material from overheating when the radiation energy density is increased. The inventors were able to determine that a too rapid decrease in the radiation energy density is not as detrimental as a too rapid increase.

[0107] Furthermore, preferably, at the endpoint of the first partial trajectory, the beam energy density has a value that is less than or equal to 70% of the mean or maximum value of the beam energy density specified for the motion along the first partial trajectory, and / or at the starting point of the second partial trajectory, the beam energy density

[0108] EP 2379 / PK / 31 .07.2025 a value that is less than or equal to 80% of the mean or maximum value of the beam energy density specified for movement along the second partial trajectory.

[0109] Preferably, the beam energy density along the transition trajectory is monotonically varied from a value less than or equal to 70% of the average or maximum value of the beam energy density for the beam's movement along the first partial trajectory to a value less than or equal to 80% of the average or maximum value of the beam energy density for the beam's movement along the second partial trajectory. In this approach, to achieve a lower beam energy density in the transition trajectory region, the beam energy density is reduced towards the end of the first partial trajectory and / or only increased to the desired value for the movement along the second partial trajectory during the beam's movement.

[0110] It is further preferred that for the movement along the transition trajectories a minimum value of the beam energy density is specified in relation to the value of the beam energy density at the end of the temporally preceding first or second partial trajectory, wherein in particular the specified minimum value of the beam energy density is less than or equal to 50% of the value of the beam energy density at the end of the temporally preceding first or second partial trajectory.

[0111] In this approach, the value of the beam energy density for the movement along the transition trajectory is chosen to be very low.

[0112] In this approach, it is preferred that the minimum value of the beam energy density specified in connection with the value of the beam energy density at the end of the preceding first or second partial trajectory is compared with a predetermined minimum value for the beam energy density along the transition trajectory. A predetermined minimum value for the beam energy density along the transition trajectory is, for example, at least 20%, preferably at least 40%, particularly preferably at least 60%, and / or at most...

[0113] EP 2379 / PK / 31 .07.2025 95%, preferably at most 85%, particularly preferably at most 70% of an average or maximum value of the beam energy density along the first and second partial trajectories. If the minimum value specified in connection with the value of the beam energy density at the end of the temporally preceding first or second partial trajectory falls below the specified minimum value for the beam energy density along the transition trajectory, a value for the beam energy density along the transition trajectory is specified upon reduction of the beam energy density along the transition trajectory, which is equal to the specified minimum value for the beam energy density along the transition trajectory. This is advantageous because it allows a melt track orA melt pool is obtained during the movement of the jet along the transition trajectory and the first and second sub-trajectories connected to the transition trajectory. The formation of a melt pool or melt track means that at least partial, preferably complete, melting of the build-up material occurs at adjacent locations.

[0114] Preferably, for the movement of the beam along a trajectory, it is specified that the extent of the beam's impact area on the surface of the build-up material at at least one point of one of the number of transition trajectories differs from the extent of the beam's impact area on the surface of the build-up material along the associated first and second partial trajectories, wherein preferably the minimum extent of the beam's impact area at at least one point of one of the number of transition trajectories is smaller than the minimum extent of the beam's impact area along the associated first and second partial trajectories.or wherein preferably the maximum extent of the impact area of ​​the beam at at least one point of one of the number of transition trajectories is smaller than the maximum extent of the impact area of ​​the beam along the associated first and second sub-trajectories.

[0115] EP 2379 / PK / 31 .07.2025 As a rule, but not necessarily, the focus of the beam lies in the build plane, so that the extent of the impact area on the surface of the build material then corresponds to the focus.

[0116] A reduced extent of the beam's impact area on the surface can be advantageous because it results in a smaller amount of molten build-up material along the transition trajectory. The extent of the impact area along the transition trajectory can be, for example, at least 10%, preferably at least 15%, particularly preferably at least 20%, and / or at most 80%, preferably at most 55%, particularly preferably at most 40% of an average value, or with a minimum value for the impact area extent along the first and second partial trajectories. Furthermore, reducing the impact area, for example by focusing the radiation more strongly onto the build-up plane, increases the radiation intensity.

[0117] The radiation intensity I is calculated here as follows:

[0118] I = PL / A, (4) because I = E / (t*A) where PL is again the power in the beam (e.g. the laser power) and A is the area of ​​the impact zone on the building plane (extent of the impact zone).

[0119] In principle, one could also derive an energy density EA from the beam intensity according to the relationship

[0120] EA = I ■ t (5) derive, which has the unit W / m 2 or W / mm 2 would have. However, such an energy density EA must not be confused with the radiant energy density EBF mentioned above, which does not refer to the area of ​​the impact zone. The quantity t above simply reflects the unit of time, while EA otherwise refers to the area A of the impact zone. In contrast, the above relationship (2) for the

[0121] EP 2379 / PK / 31 .07.2025 Calculation of the radiation energy density with reference to the area on which radiation strikes within the time interval.

[0122] Increasing the radiation intensity can be advantageous so that the behavior of the melt pool or melt track during the formation of a keyhole can be better controlled.

[0123] On the other hand, or depending on the requirements of the process or the component, it can be advantageous to reduce the radiation intensity so that not too much build-up material outside the (partial) area to be solidified is melted. If the radiation intensity along the transition trajectory is (or is intended to be) reduced compared to the radiation intensity along the first and second partial trajectories, the power of the radiation source must be reduced and / or the beam velocity increased simultaneously when reducing the extent of the impact area in order to achieve an overall lower beam energy density in the transition trajectory. Reducing the radiation intensity along the transition trajectory can also result in a smaller melt pool volume (or a narrower melt track width).When reducing the radiation intensity along the transition trajectory, the radiation intensity and the extent of the beam's impact area along a transition trajectory on the build-up material are reduced such that a minimum value of at least 20%, preferably at least 40%, particularly preferably at least 60% and / or at most 95%, preferably at most 85%, particularly preferably at most 70% of an average or maximum value of the radiation intensity along the first and second partial trajectories is not undercut. This enables a melt track or melt pool to be obtained as the beam moves along the transition trajectory and the first and second partial trajectories associated with the transition trajectory.The presence of a melt trace means that at least partial, preferably complete, melting of the build-up material takes place at adjacent locations.

[0124] EP 2379 / PK / 31 .07.2025 An increased extent of the jet's impact area on the surface can be advantageous because it reduces the depth of the weld pool. Continuous jet movement without interruption of energy supply can result in greater penetration depth, particularly in deep penetration welding. This means that the melting process creates a weld pool that extends over several layers of already solidified build-up material (possibly also into the weld pool of a previous melting process). The extent of the impact area along the transition trajectory can, for example, be at least 150%, preferably at least 250%, particularly preferably at least 350%, and / or at most 1400%, preferably at most 1000%, particularly preferably at most 600% of an average value or a maximum value of the impact area's extent along the first and second partial trajectories.Increasing the extent of the beam's impact area on the surface results in a smaller penetration depth into the build-up material. This smaller penetration depth reduces, and preferably completely prevents, the ejection of build-up material from the melt pool and thus the formation of pores. Furthermore, increasing the extent of the beam's impact area on the surface reduces the radiation intensity, provided the other parameters along the transition trajectory remain unchanged. This is particularly advantageous when the radiation intensity along the transition trajectory is (or is intended to be) reduced compared to the radiation intensity along the first and second partial trajectories.Preferably, the extent of the beam's impact area along a transition trajectory on the build-up material is increased such that a minimum value for the radiation intensity (at least 20%, preferably at least 40%, particularly preferably at least 60% and / or at most 95%, preferably at most 85%, particularly preferably at most 70% of an average or maximum value of the radiation intensity along the first and second partial trajectories) is not undercut. This ensures that a melt track or melt pool is maintained during the beam's movement along the transition trajectory and the first and second partial trajectories connected to the transition trajectory, even with a shallower weld penetration depth. It is also possible to adjust other irradiation parameters, e.g., the radiation power and / or the...

[0125] EP 2379 / PK / 31 .07.2025 The speed of movement must be adjusted when the extent of the beam's impact area increases, so that the radiation intensity along the transition trajectory remains constant or increases.

[0126] Preferably, in the data model, the area to be solidified is assigned to a first partial cross-section and a second partial cross-section of the object section, wherein it is specified that in the first partial cross-section at least one energy input parameter has a different value on average than in the second partial cross-section, wherein in the data model at least one trajectory extends over the first and second partial cross-sections.

[0127] An energy input parameter can be the beam energy density and, in particular, the velocity of the beam impacting the build-up material along the partial trajectories, the radiant power or intensity in the beam, its diameter or focal depth, its beam profile, or the distance between adjacent partial trajectories. The mean value of an energy input parameter can, for example, be the arithmetic mean of the values ​​of an energy input parameter specified at different locations within a partial cross-section.

[0128] Preferably, the object section extends over several superimposed cross-sections, each containing a first and second sub-cross-section as defined above. It is also conceivable that cross-sections of an object section contain more than two sub-cross-sections, where at least one energy input parameter has a different average value in one sub-cross-section than in another.

[0129] The first and second partial cross-sections can differ, for example, in that they belong to areas of the object that are intended to have different mechanical properties, or that belong to areas of the object that differ significantly in their geometry, e.g., the object's interior and object's edge, or an area in which the object has a very small cross-sectional area parallel to the building plane and an area in which the object

[0130] EP 2379 / PK / 31 .07.2025 has a large cross-sectional area parallel to the construction plane. The sub-cross-sections can also differ in whether or not non-solidifying material is present above and below them during the construction process, and in how many layers of non-solidifying material is present above and below. A sub-cross-section can, for example, be defined by the fact that the energy input parameter values ​​within it do not exceed a predetermined fluctuation limit. As a rule, a precisely defined boundary is established between areas / sub-cross-sections of an object section, separating sub-cross-sections with at least one different energy input parameter on average. This energy input parameter may, but does not necessarily, change directly at or near the boundary.

[0131] The inventors found that, particularly when several sub-areas of an object section with different energy input parameters are present, the process quality during the manufacturing of the object section can be improved. One explanation for this is that, in the inventive method, the supply of radiant energy is not interrupted when crossing the boundary between different sub-areas / partial cross-sections. This prevents a boundary between sub-areas / partial cross-sections, resulting from at least one difference in energy input parameter, from being barely or not at all pronounced in the finished object.

[0132] Preferably, a downskin area is assigned to the first partial cross-section or the second partial cross-section, which is defined by the fact that no hardening of the superstructure material takes place in at least one of the cross-sections to be hardened by p below it, where p is a predetermined non-zero natural number, or an upskin area is assigned, which is defined by the fact that no hardening of the superstructure material takes place in at least one of the cross-sections to be hardened by p above it, where p is a predetermined non-zero natural number.

[0133] EP 2379 / PK / 31.07.2025 A downskin area can also be characterized by having an outer surface of the object being manufactured that faces downwards during manufacturing, towards the substrate which supports the stack of layers of the build-up material. Similarly, an upskin area can be characterized by having an outer surface of the object being manufactured that faces upwards, i.e., away from the substrate, during manufacturing. The build-up material below and above a downskin or upskin area, which is not yet solidified, generally has a lower thermal conductivity than already melted or solidified build-up material. Therefore, it is often precisely in downskin or upskin areas that at least one energy input parameter has a different average value than in an area that is underlain and overlain by build-up material to be solidified.

[0134] Furthermore, the data model preferably specifies that the transition from the first sub-cross-section to the second sub-cross-section occurs by sampling a sub-cross-section transition trajectory, which is one of the transition trajectories.

[0135] The options for selecting energy input parameters or irradiation parameters during the scanning of the transition trajectory, as described above, apply equally to the partial cross-section transition trajectory. This differs from the other transition trajectories only in that it involves a transition from the first partial cross-section to the second partial cross-section.

[0136] In this approach, the transition from the first to the second cross-section during the radiation scanning of the build-up material does not occur during the scanning of a partial trajectory. This allows for completely independent scanning strategies to be chosen for the different energy input parameters in the first and second cross-sections, for example, by selecting different distances between the first and second partial trajectories. For instance, a change in an energy input parameter could then be made during a scan of the partial cross-section transition trajectory.

[0137] EP 2379 / PK / 31 .07.2025 Even more preferably, for the movement of the beam along the partial cross-section transition trajectory, a monotonic decrease and / or a monotonic increase of an amount of the movement speed or a constant amount of the movement speed is specified.

[0138] The term "monotonic" is intended to express that the decrease / increase in the magnitude of the speed of motion can occur continuously, in steps, or in a mixture of both.

[0139] Even more preferably, for the successive movement of the beam along the partial trajectory preceding the scanning of the partial cross-section transition trajectory, along the partial cross-section transition trajectory and the partial trajectory following the scanning of the partial cross-section transition trajectory, the magnitude of the velocity of movement is specified such that the magnitude of the velocity of movement decreases monotonically during the movement along a segment of the partial trajectory preceding the scanning of the partial cross-section transition trajectory and / or along a segment of the transition trajectory and / or along a segment of the partial trajectory following the scanning of the partial cross-section transition trajectory.

[0140] This approach is used when the average speed of movement in the second sub-section is to be lower than in the first sub-section. Preferably, the segment of the first sub-trajectory includes the endpoint of the first sub-trajectory or at least borders upon it. More preferably, the segment of the second sub-trajectory includes the starting point of the second sub-trajectory or at least borders upon it.

[0141] Even more preferred for the successive movement of the beam along the partial trajectory preceding the scanning of the partial cross-section transition trajectory, along the partial cross-section transition trajectory, and along the partial trajectory following the scanning of the partial cross-section transition trajectory is the following:

[0142] EP 2379 / PK / 31 .07.2025 The magnitude of the speed of movement is specified in such a way that the magnitude of the speed of movement increases monotonically during the movement along a segment of the partial trajectory preceding the sampling of the partial cross-section transition trajectory and / or along a segment of the transition trajectory and / or along a segment of the partial trajectory following the sampling of the partial cross-section transition trajectory.

[0143] This approach is used when the average speed of movement in the second sub-section is to be higher than in the first sub-section. Preferably, the segment of the first sub-trajectory includes the endpoint of the first sub-trajectory or at least borders it. More preferably, the segment of the second sub-trajectory includes the starting point of the second sub-trajectory or at least borders it.

[0144] It is further preferred that a monotonic change in beam energy density or a constant beam energy density is specified for the movement of the beam along the partial cross-section transition trajectory.

[0145] The term "monotonic" is intended to express that the decrease / increase in radiation energy density can occur continuously, in steps, or in a mixture of both.

[0146] It is further preferred that for the successive movement of the beam along the partial trajectory preceding the scanning of the partial cross-section transition trajectory, along the partial cross-section transition trajectory and the partial trajectory following the scanning of the partial cross-section transition trajectory, the value of the beam energy density is specified such that the value of the beam energy density decreases monotonically during the movement along a segment of the partial trajectory preceding the scanning of the partial cross-section transition trajectory and / or along a segment of the transition trajectory and / or along a segment of the partial trajectory following the scanning of the partial cross-section transition trajectory.

[0147] EP 2379 / PK / 31 .07.2025 This procedure is used when the average beam energy density of the second sub-area cross-section is to be lower than that of the first sub-area cross-section. Preferably, the segment of the first sub-trajectory includes the endpoint of the first sub-trajectory or at least borders upon it. More preferably, the segment of the second sub-trajectory includes the starting point of the second sub-trajectory or at least borders upon it.

[0148] It is further preferred that for the successive movement of the beam along the partial trajectory preceding the scanning of the partial cross-section transition trajectory, along the partial cross-section transition trajectory and the partial trajectory following the scanning of the partial cross-section transition trajectory, the value of the beam energy density is specified such that the value of the beam energy density increases monotonically during the movement along a segment of the partial trajectory preceding the scanning of the partial cross-section transition trajectory and / or along a segment of the transition trajectory and / or along a segment of the partial trajectory following the scanning of the partial cross-section transition trajectory.

[0149] This approach is used when the average beam energy density of the second sub-section is to be higher than that of the first sub-section. Preferably, the segment of the first sub-trajectory includes or at least borders the endpoint of the first sub-trajectory. More preferably, the segment of the second sub-trajectory includes or at least borders the starting point of the second sub-trajectory.

[0150] Preferably, a welding regime applied in the first cross-section is maintained during the transition from the first partial cross-section to the second partial cross-section.

[0151] EP 2379 / PK / 31.07.2025 Here, a welding regime is preferably understood to mean process parameters under which a deep penetration welding process takes place, or under which no deep penetration welding process takes place, i.e., a heat conduction welding process. The two welding regimes, deep penetration welding and heat conduction welding, can be distinguished by whether or not a keyhole is formed during the welding process, i.e., how deep the weld pool is perpendicular to the build plane. Since a change in the welding regime can lead to discontinuities in the hardened material, maintaining the welding regime improves component homogeneity.

[0152] Preferably, the last sampled partial trajectory or the first sampled partial trajectory of the trajectory runs parallel to at least a part of the contour of the object cross-section.

[0153] Often, different energy input parameters are chosen for the contour, i.e., the edge of an object's cross-section, than for the interior. This is because the quality of the contour's formation is crucial for the surface quality of the finished object. For example, a surface with low roughness is often desirable, so it must be ensured that loose build-up material does not unintentionally adhere to or bond with the surface. The contour can therefore also be considered a partial cross-section in which at least one energy input parameter has a different average value than in the interior. Typically, the beam is moved parallel to the contour for hardening, regardless of whether the contour is hardened first and then the interior, or first the interior and then the contour.

[0154] In an additive manufacturing process according to the invention for producing a three-dimensional object, wherein the object is produced by means of an additive manufacturing device by applying a build material layer upon layer and solidifying the build material in a build plane by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by irradiating these locations with at least one beam

[0155] EP 2379 / PK / 31 .07.2025 according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, the process of the additive manufacturing process is controlled by a control data set generated using a control data provision method according to the invention.

[0156] If control data provided according to the invention are used in a control data set that has been generated for the control of an additive manufacturing process, in particular the control of a layer-by-layer additive manufacturing process, such as a layer-by-layer powder melting or sintering process, such as SLS or DMLS or SLM, then the component quality of the object can be improved.

[0157] The invention is particularly advantageous in additive manufacturing processes where the depth of the melt pool, generated by an impacting jet in the build-up material, is greater than twice the thickness of a build-up material layer, preferably greater than three times the thickness of a build-up material layer. This condition is met, for example, when melting metal powder by means of deep penetration welding (keyhole welding).

[0158] An inventive device for providing control data for an additive manufacturing device for producing a three-dimensional object, wherein the object is produced by means of the additive manufacturing device by applying a build material in a build plane by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by scanning these locations with at least one beam according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, comprises: a data access unit designed to access computer-based model data of at least one section of the object to be produced, and a data model generation unit designed to generate at least one data model of a data model of the object to be produced.

[0159] EP 2379 / PK / 31 .07.2025 to generate a solidifying area of ​​a build-up material layer, which is associated with an area of ​​a cross-section of the object, wherein motion vectors of the at least one beam in the build plane are specified in the data model for scanning locations of the area to be solidified along a number of trajectories, wherein the beam is moved along a trajectory without interrupting the supply of radiant energy to the layer, wherein each trajectory has a number of first sub-trajectories and a number of second sub-trajectories, an angle between a first sub-trajectory and a second sub-trajectory following this first sub-trajectory is greater than 90°, preferably greater than 120°, and less than or equal to 180°, and wherein the beam is moved alternately along first and second sub-trajectories,wherein a transition trajectory is specified between a first partial trajectory and a second partial trajectory and between a second partial trajectory and a first partial trajectory, wherein a value of radiation intensity is specified for the movement of the beam along the transition trajectories which is less than the average value of radiation intensity when the beam moves along the first and second partial trajectories connected with the transition trajectory, and a control data provisioning unit which is designed to provide control data according to the at least one data model generated by the data model generation unit for the generation of a control data set for the additive manufacturing device.

[0160] The provision of the data model generated in the second step for the generation of a control data record can be performed by the control data provisioning unit itself, by integrating the generated data model into a control data record for the additive manufacturing device. Provisioning also includes forwarding the data model to a data processing device, which integrates the data model into a control data record, or forwarding it directly to an additive manufacturing device. In particular, it is possible to dynamically provide data models for object cross-sections yet to be produced during a manufacturing process in the additive manufacturing device. Specifically, in the

[0161] EP 2379 / PK / 31 .07.2025 states that the data models generated in the second step are not individually provided for an additive manufacturing process. Rather, several generated data models can first be collected and then made available in their entirety for integration into a control data set.

[0162] In particular, the device for providing control data can also be integrated into an additive manufacturing device and interact with a control unit in the additive manufacturing device.

[0163] An inventive device for computer-aided control of a number of energy input devices of an additive manufacturing device for producing a three-dimensional object by means of the same, wherein the object is produced by means of the additive manufacturing device by applying a build material layer upon layer and solidifying the build material in a build plane by supplying radiant energy to locations in each layer that are associated with the cross-section of the object in that layer, by scanning these locations with at least one beam according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, is designed such that solidification of the build material is specified by scanning locations of the area to be solidified along a number of trajectories.along which the beam is moved without interrupting the supply of radiant energy to the layer, wherein each trajectory has a number of first partial trajectories and a number of second partial trajectories, wherein an angle between a first partial trajectory and a second partial trajectory following this first partial trajectory is greater than 90°, preferably greater than 120°, and less than or equal to 180°, and wherein the beam is moved alternately along first and second partial trajectories, wherein a transition trajectory is specified between a first partial trajectory and a second partial trajectory and between a second partial trajectory and a first partial trajectory.

[0164] EP 2379 / PK / 31 .07.2025 wherein, for the movement of the beam along the transition trajectories, a value of radiation intensity is specified which is less than the average value of radiation intensity when the beam moves along the first and second sub-trajectories associated with the transition trajectory.

[0165] The device for the computer-aided control of a number of energy input devices can be implemented solely using software components, using a combination of hardware and software components, or even solely using hardware components. A device implemented solely using software components can interact with, or be integrated into, a control unit in an additive manufacturing device for the production of a three-dimensional object. The device for the computer-aided control of a number of energy input devices can improve the component homogeneity of objects produced by an additive manufacturing process.In particular, the device can implement the production of objects by an additive manufacturing process based on a control data set that was generated by means of a method according to the invention for providing control data.

[0166] An additive manufacturing device according to the invention for producing a three-dimensional object, wherein in the additive manufacturing device the object is produced by applying a build material layer upon layer and solidifying the build material in a build plane by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by scanning these locations with at least one beam according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, wherein the additive manufacturing device comprises: a layer application device suitable for applying a layer of a build material to an already existing, preferably selectively solidified, build material layer, and an energy input device suitable forto supply radiant energy to points assigned to the cross-section of the object in a layer by,

[0167] EP 2379 / PK / 31 .07.2025 Locations are scanned with at least one beam bundle according to a set of energy input parameter values ​​along a number of trajectories, wherein the additive manufacturing device has a device according to the invention for computer-aided control of a number of energy input devices and / or is connected to a device according to the invention for computer-aided control of a number of energy input devices via a signal connection.

[0168] An energy input device can comprise a number of radiation sources for generating radiation, e.g., electromagnetic radiation or particle radiation, as well as an associated number of beam deflection or redirection devices for directing the radiation onto the build material. The radiation sources can be, for example, one or more gas or solid-state lasers or any other type of laser, such as laser diodes.

[0169] A computer program according to the invention contains program code means to execute all steps of an inventive method for providing control data or an inventive additive manufacturing process when the computer program is executed by means of a data processor, in particular a data processor interacting with an additive manufacturing device. "Interacting" here means that the data processor is either integrated into the additive manufacturing device or can exchange data with it. The implementation of the inventive method for providing control data and the associated device by means of software enables easy installation on various computer systems at different locations (for example, at the site of the designer of the object or at the site of the operator of the additive manufacturing device).

[0170] Further features and advantages of the invention will become apparent from the description of exemplary embodiments with reference to the accompanying figures.

[0171] EP 2379 / PK / 31 .07.2025 Fig. 1 shows a schematic, partially sectional view of an exemplary device for the additive manufacturing of a three-dimensional object according to an embodiment of the invention,

[0172] Fig. 2 shows an example of a transition according to the invention from a first partial trajectory to a second partial trajectory.

[0173] Figures 3 and 4 show examples of the course of the radiation intensity I and the velocity v when the beam moves along a transition trajectory.

[0174] Fig. 5 illustrates the process of providing tax data,

[0175] Fig. 6 shows the schematic structure of a device for providing control data,

[0176] Fig. 7 shows a procedure known to the applicant for scanning an object cross-section with energy radiation,

[0177] Fig. 8 serves to further explain the procedure shown in Fig. 7.

[0178] Fig. 9 shows an embodiment in which there are two partial cross-sections that are exposed differently.

[0179] Fig. 10 shows a lateral section of an object section to be produced together with the surrounding build-up material to illustrate downskin and upskin areas.

[0180] Fig. 11 shows a top view of an object cross-section to be consolidated, in which there are two partial cross-sections which, according to a further embodiment, are exposed differently.

[0181] EP 2379 / PK / 31 .07.2025 Fig. 12 shows another embodiment in which there are two partial cross-sections that are exposed differently.

[0182] For a description of the invention, an additive manufacturing device according to the invention will first be described below using the example of a laser sintering or melting device with reference to Fig. 1.

[0183] To build an object 2, the laser sintering or laser melting device 1 includes a process chamber or build chamber 3 with a chamber wall 4. An upwardly open build container 5 with a container wall 6 is arranged in the process chamber 3. The upper opening of the build container 5 defines a working plane 7 (also called build plane), and the area of ​​the working plane 7 located within the opening, which can be used to build the object 2, is referred to as the build area 8.

[0184] Inside the build container 5, a support 10, movable in a vertical direction V, is arranged. A base plate 11 is attached to the support plate, forming the bottom of the container 5. The base plate 11 can be a separate plate attached to the support 10, or it can be integral with the support 10. Depending on the powder used and the process, a build platform 12 can be attached to the base plate 11 as a base on which the object 2 is built. Alternatively, the object 2 can be built directly on the base plate 11, which then serves as the build platform. In Fig. 1, the object 2 to be formed in the container 5 on the build platform 12 is shown in an intermediate state below the working plane 7, with several solidified layers surrounded by unsolidified build material 13.

[0185] The laser sintering or melting device 1 further includes a storage container 14 for a build material 15, in this example a powder that can be solidified by electromagnetic radiation, and a recoater 16 movable in a horizontal direction H for applying the build material 15 within the build area 8. Optionally, a heating device, e.g. a

[0186] EP 2379 / PK / 31 .07.2025 A radiant heating element 17 shall be provided for heating the applied assembly material. For example, an infrared radiator may be provided as the radiant heating element 17.

[0187] The exemplary additive manufacturing device 1 further comprises an energy input device 20 with a laser 21, which generates a laser beam 22, and a deflection or beam deflection device 23, for example one or more galvanometer mirrors with associated drive, which deflects or redirects the laser beam 22. By means of a focusing device 24, the laser beam is then focused through an input window 25, which is located on the top of the process chamber 3 in the chamber wall 4, onto the build plane 7.

[0188] In laser sintering or laser melting, an energy input device can, for example, comprise one or more gas or solid-state lasers or any other type of laser, such as laser diodes. The specific setup of a laser sintering or melting device shown in Fig. 1 is therefore only exemplary for the present invention and can, of course, be modified, particularly when using a different energy input device than the one shown.

[0189] The laser sintering device 1 further includes a control unit 29, which controls the individual components of the device 1 in a coordinated manner to carry out the build process. Alternatively, the control unit 29 can also be located partially or completely outside the additive manufacturing device. The control unit can include a CPU whose operation is controlled by a computer program (software). The computer program can be stored separately from the additive manufacturing device in a storage device, from where it can be loaded (e.g., via a network) into the additive manufacturing device, in particular into the control unit.

[0190] During operation, the control unit 29 lowers the carrier 10 layer by layer, activates the coater 16 to apply a new powder layer, and activates the deflection device 23 and, if applicable, the laser 21 and / or the focusing device 24 to solidify the respective layer at the

[0191] EP 2379 / PK / 31 .07.2025 corresponding points on the respective object by scanning these points with the laser.

[0192] All statements made below apply not only to laser sintering or melting devices, but also to other types of additive manufacturing devices in which heat energy is introduced into the build material by means of radiation.

[0193] In the additive manufacturing device just described as an example, a manufacturing process takes place in such a way that the control unit 29 processes a control data set.

[0194] The control data set specifies to an energy input device, in the case of the laser sintering or laser melting device described above, in particular the deflection device 23, at each point during the solidification process, which point on the working plane 7 the radiation is to be directed. As shown in Fig. 6, a device 100 for providing control data to an additive manufacturing device comprises a data access unit 101, a data model generation unit 102, and a control data provision unit 103. The operation of the device 100 for providing control data is described by way of example with reference to Fig. 5.

[0195] In the device 100 shown in Fig. 6 for providing control data for an additive manufacturing device, the data access unit 101 first accesses a number, i.e., one or more, of layer data sets, each of which contains a data model of an area of ​​a build-up material layer to be selectively solidified during manufacturing, preferably the entire area of ​​a build-up material layer to be solidified, which corresponds to a cross-section of an object section. In the process sequence shown in Fig. 5, this is the first step S1.

[0196] In the second step S2 shown in Fig. 5, the data model generation unit 102 now specifies in at least one data model of at least one object section a solidification of locations of a build-up material layer in a

[0197] EP 2379 / PK / 31 .07.2025 temporal sequence corresponding to the movement of a beam along a trajectory over the build-up material. In particular, the movement along partial trajectories 54 shown in Fig. 7 is defined in an interior region 52 of an object cross-section 50, especially in a sub-region 53 of the interior region 52, i.e., for example, a strip.

[0198] After at least one data model has been generated in the second step S2 in Fig. 5, the control data provisioning unit 103 shown in Fig. 6 then provides control data for the generation of a control data record (in Fig. 5 this is step S3). Either the at least one data model generated in the second step S2 can be provided as control information (control data), or the data model can be reformatted into a control data record for better integration. The described procedure can be applied to all sub-trajectories within a strip-shaped or square sub-area.

[0199] In an additive manufacturing process controlled by a control data set generated based on the control data provided in step S3, the build material is then scanned with a beam along partial trajectories (hereinafter also referred to as hatch lines) that are essentially parallel to each other, for example to solidify an inner area 52. For this purpose, the control device 29 then controls the deflection device 23 accordingly.

[0200] Fig. 2 shows a section of a partial area 53 of an interior area 52, which is intended to illustrate the differences from the prior art procedure shown in Fig. 8. Fig. 2 shows, by way of example, a first partial trajectory 64 and a second partial trajectory 65, which are traversed in reverse direction, with the second partial trajectory 65 being traversed after the first partial trajectory 64 in this example. Furthermore, a transition trajectory 55 can be seen in Fig. 2 to the left of the dashed vertical guideline, which is traversed when the beam changes from the first partial trajectory 64 to the second partial trajectory 65.

[0201] EP 2379 / PK / 31 .07.2025 In the example shown in Figure 2, the beam is not switched off as it passes through the transition trajectory 55, as in the prior art shown in Figure 8, but is moved along the transition trajectory 55 without interrupting the supply of radiant energy to the build-up material layer. In particular, a radiation intensity is set for the movement of the beam along the transition trajectory 55 that leads to at least partial, preferably complete, melting of the build-up material.

[0202] The radiation intensity along the transition trajectory 55 is nevertheless set to a value lower than the average radiation intensity when the beam moves along the first and second partial trajectories 64 and 65, respectively. The radiation intensity can be influenced by modifying at least one of the following parameters: the radiation power, the beam focus, or the beam's velocity, i.e., the area where the radiation impacts the build-up layer, i.e., the build-up material. Furthermore, attenuators can be used to reduce the radiation intensity, or, for example, a portion of the radiation can be coupled out so that it does not reach the build-up material layer. It should also be noted that when using pulsed radiation, the pulse parameters can also be modified to result in a lower radiation intensity.

[0203] In Fig. 2, the magnitude of the radiation intensity is illustrated by circles of different diameters. The diameter of the circles is not intended to represent the size of the focus, but rather to depict the radiation intensity along the transition trajectory. As can be seen, the diameter of the circles along the transition trajectory 55 is smaller than along the first and second partial trajectories 64 and 65, respectively, illustrating the lower radiation intensity along the transition trajectory 55. Furthermore, the beam's velocity is lower in the region of the transition trajectory, which facilitates the reversal of motion. Since a lower velocity increases the radiation intensity, the reduced velocity must be more than compensated for by modifying other parameters, in particular by reducing the radiation power and / or increasing the beam's impact area.

[0204] EP 2379 / PK / 31 .07.2025 to achieve an overall lower radiation intensity. Conversely, by reducing the beam power to a certain (suitable) degree and / or increasing the beam's impact area, the movement speed can be reduced so that even with a reduction in radiation intensity, a minimum value for the radiation intensity is not undercut.

[0205] Preferably, the reduction in radiation intensity does not occur only in the region of the transition trajectory 55, but already towards the endpoint 64E of the first partial trajectory 64. In Fig. 2, this is illustrated by a decreasing diameter of the circles towards the endpoint 64E.

[0206] As mentioned above, a change in radiation intensity according to equation (4) (I = PL / A, see above) can be achieved, for example, by changing the radiant power. While the diameters of the circles in Fig. 2 symbolize the magnitude of the radiation intensity, they can also represent a profile of the radiant power, because a reduction (increase) in the radiant power also decreases (increases) the radiation intensity. Preferably, the radiant power at the endpoint 64E is only a maximum of 70% of the maximum or average radiant power along the first partial trajectory 64. Likewise, the radiant power in the region of the transition trajectory 55 preferably does not yet increase to the maximum or average value along the second partial trajectory 65. Rather, from the starting point 65A of the second partial trajectory 65, the radiant power is further increased as it moves along the second partial trajectory 65.Preferably, the radiation power at the starting point 65A is still below 80% of the maximum or average laser power along the second partial trajectory 65.

[0207] Furthermore, also in connection with equation (4), a change in radiation intensity can be achieved by changing the beam focus or the beam's impact area in the plane of construction. According to equation (4), the radiation intensity is reduced (increased) by increasing (decreasing) the beam focus. Preferably, the beam's impact area at endpoint 64E has at least 150% of the maximum or average impact area.

[0208] EP 2379 / PK / 31 .07.2025 along the first trajectory 64. Likewise, the beam focus in the area of ​​the transition trajectory 55 is preferably not yet already at its maximum value.

[0209] The average value along the second partial trajectory 65 is reduced. Rather, from the starting point 65A of the second partial trajectory 65, the beam diameter is further reduced compared to its value at the endpoint 64E. Preferably, the impact area of ​​the beam at the starting point 65A is still greater than 150% of the maximum or average diameter along the second partial trajectory 65.

[0210] In the same way as the radiation power, the speed of motion can also be reduced as the beam moves along the first partial trajectory 64 towards the endpoint 64E of the first partial trajectory 64 and, after passing through the transition trajectory 55, only be increased again to the maximum value for the speed of motion along the second partial trajectory 65 as the beam moves along the second partial trajectory 65. Preferably, the magnitude of the speed of motion at the endpoint 64E is only a maximum of 75% of the average speed of motion along the first partial trajectory 64 and is only a maximum of 85% of the average speed of motion along the second partial trajectory 65 at the starting point 65A of the second partial trajectory 65. At a constant radiation intensity (i.e.,Assuming a constant beam impact area and constant radiation power, a change in the speed of motion leads to a change in the energy density EA according to equation (5), EA = I t, because the time t is influenced by the speed of the beam. A reduction in speed leads to an increase in the time t in which the radiation travels a distance (trajectory, in particular transition trajectory or partial trajectory) and accordingly to an increase in the energy density EA. As already mentioned, a reduced speed of motion facilitates the reversal of motion.Preferably, a reduced radiation intensity is specified for the endpoint 64E and for the starting point 65A (by defining an impact area and a radiation power) so that, despite the reduction in the speed of movement between the endpoint 64E and the starting point 65A, an energy density is obtained which is smaller compared to a maximum value or an average value along the first and / or the second partial trajectory.

[0211] EP 2379 / PK / 31.07.2025 The movement speed can be controlled by appropriately controlling the beam deflection device, in particular the galvanometer mirrors. Specifically, the control of the beam deflection device depends on a predefined time interval (clock signal), e.g., 10 ps, ​​5 ps, 4 ps, 2 ps, etc. In particular, along a transition trajectory and / or along a segment of a partial trajectory (preferably along a segment of a partial trajectory adjacent to the transition trajectory), a specific location (xj, yj) is specified in the control data at each clock interval tj, towards which the beam is to be directed. The locations (xj, yj) and (xj+i, yj+i) are specified at successive clock intervals tj and tj+i. For the build process, a movement speed is set as described in detail above.According to equation (5), the energy density depends on the velocity of motion and thus, through the velocity of motion, on the time interval between the cycle times tj and tj+i, and on the distance between the positions (xj, yj) and (xj+i , yj+i ) specified at the cycle times tj and tj+i. The circles in Fig. 2 can be seen as positions (xj, yj).

[0212] In a further embodiment of the invention, a radiation energy density according to equation (1), EB = PL / V, exhibits a similar profile to the radiation intensity profile in Figure 2. Preferably, the reduction of the energy density EB does not occur only in the region of the transition trajectory 55, but already towards the endpoint 64E of the first partial trajectory 64.

[0213] A change in the energy density EB can be achieved according to equation (1) by changing the radiant power. In this case, the diameters of the circles in Fig. 2 symbolize the magnitude of the radiant power; i.e., the radiant power is reduced towards the endpoint 64E. Preferably, the radiant power at the endpoint 64E is only a maximum of 70% of the maximum or average radiant power along the first partial trajectory 64. Likewise, the radiant power in the region of the transition trajectory 55 preferably does not yet increase to the maximum or average value along the second partial trajectory 65. Rather, from the starting point 65A of the second partial trajectory 65, the radiant power is further increased during movement along the second partial trajectory 65. Preferably,

[0214] EP 2379 / PK / 31 .07.2025 the radiative power at the starting point 65A is still below 80% of the maximum or average radiative power along the second partial trajectory 65.

[0215] Furthermore, as already explained and in connection with equation (1), a change in the energy density EB can also be achieved by changing the velocity. Preferably, the velocity is reduced towards the endpoint 64E, similar to the radiant power, then increased again along the transition trajectory 55, but not yet to the maximum or average value along the second partial trajectory 65, and then further increased along the second trajectory 65. Preferably, the velocity at the endpoint 64E is 75% of the maximum or average velocity along the first partial trajectory 64, and at the starting point 65A it is 85% of the maximum or average velocity along the second partial trajectory 65.

[0216] Figure 3 shows an exemplary curve of the radiation intensity I. In the example shown in Figure 3, the radiation intensity I is gradually reduced from its value at endpoint 64E and, after reaching a minimum, gradually increased again to its value at the starting point 65A of the second trajectory 65. It is important to note that the increase after reaching the minimum is slower than the decrease from the value at endpoint 64E. This is evident in smaller intensity differences from step to step and in more gradual increases. The reason for this asymmetry is to prevent excessively rapid deepening of the keyhole by an excessively rapid increase in radiation intensity. According to the inventors' observations, an excessively rapid increase in radiation intensity leads to an increase in the porosity of the solidified material and, due to spattering, generally degrades the construction quality.

[0217] The radiation intensity curve in Fig. 3 is otherwise only exemplary, and the number of steps, as well as the height and length of the steps, can also be changed. The radiation intensity can, for example, be set to at least 2, preferably at least 3 steps.

[0218] EP 2379 / PK / 31 .07.2025 stages and / or at most 6 stages, preferably at most 8 stages, and are increased in at least 4, preferably at least 8, more preferably at least 12 and / or at most 16, preferably at most 20, more preferably at most 24 stages. In an advantageous embodiment of the invention, the radiation intensity is reduced in four stages and increased again in thirteen stages. The stage length also preferably results from a cycle time of 10 ps (the corresponding length s can be calculated from s = v ■ T (v: beam velocity, T: cycle time)). For technical reasons, it is advantageous to specify the cycle time instead of the stage length. The radiation intensity can be reduced according to equation (4). That is, a reduction in radiation intensity can be achieved by reducing the radiation power or by increasing the area of ​​the impact zone.It is also possible to reduce the radiation intensity by decreasing the area of ​​the impact zone if the radiation power is further reduced. Furthermore, with a constant (preferably reduced) radiation intensity, the energy density EA can be influenced according to equation (5) by changing the speed of travel, whereby the time t over which the beam travels along a path (trajectory) depends on the speed of travel v. It is also possible, for example, to keep the energy density E nearly constant when the radiation intensity increases (e.g., due to a decrease in the area of ​​the impact zone A) by increasing the speed of travel of the beam in the corresponding partial or transition trajectory.This is because the control of the beam deflection device, in particular the galvanometer mirror, is dependent on a predetermined time interval (clock signal), e.g., 10 ps, ​​5 ps, 4 ps, 2 ps, etc. Furthermore, a movement speed is set for the beam through the deflection device. The distance traveled within one time interval is the product of the time interval and the movement speed. Increasing the speed means that a specific distance (e.g., a partial trajectory or a transition trajectory) is covered in fewer time intervals, and thus in a shorter time. This leads to a reduction in energy EA according to equation (5).

[0219] EP 2379 / PK / 31 .07.2025 In particular, instead of a step-like change, a continuous change in radiation intensity is also possible. In any case, it is important that the reduction and subsequent increase of the radiation intensity I should be monotonic. Furthermore, although Fig. 3 explicitly depicts the course of the radiation intensity along the transition trajectory 55, as already mentioned above, the radiation intensity I can also be reduced along the first partial trajectory 64 and / or only increased again to its final value along the second partial trajectory 65.

[0220] It should also be mentioned that, as shown in Fig. 3, the minimum value of the radiation intensity is preferably less than 50% of the value at endpoint 64E of the first partial trajectory 64. Likewise, the minimum magnitude of the motion velocity is preferably less than 50% of the magnitude of the motion velocity at endpoint 64E of the first partial trajectory 64.

[0221] The representation of an exemplary curve of radiation intensity in Fig. 3 applies equivalently to a radiation energy density EB according to equation (1). The radiation energy density EB as a quantity was introduced above with reference to equation (1), which is reproduced here again:

[0222] EB = PL / V (1), where PL denotes the laser power and v the movement speed of the laser focus or beam impact area across the build plane. A reduction in the beam energy density EB is achieved, for example, by lowering the laser power PL and / or increasing the movement speed v. This is because the movement speed implicitly includes the length (L) of the path traveled and the time it takes to travel that path. The length (L) is typically given by the solidification pattern (e.g., an irradiation pattern in laser sintering processes) and is constant for a specific solidification process in a layer (within a solidification pattern). By increasing the movement speed v, the time it takes to travel the length L is reduced, while the power remains constant. This therefore leads to a reduction in the

[0223] EP 2379 / PK / 31 .07.2025 of this route with length L over the time in which this route is travelled, recorded energy density.

[0224] The beam energy density EB can be changed by a suitable profile of the movement speed (or the radiation power) along a trajectory (transition trajectory and / or partial trajectory or segment thereof). An exemplary profile of the movement speed v for changing the beam energy density EB is shown in Figure 4 (a profile of the radiation power could be implemented in an equivalent manner). In the example of Figure 4, the movement speed is gradually reduced from its value at the endpoint 64E and, after reaching a minimum, gradually increased again to its value at the starting point 65A of the second trajectory 65. A stepwise profile of the movement speed is preferably implemented by specifying a value for the movement speed v for a cycle time T, preferably of 10 ps.During this time, the beam is moved over a distance s = v ■ T, which represents the length of a stage (the length of a stage extends along the horizontal axis in Figure 4). The height (i.e., the position on the vertical axis in Figure 4) of the stage corresponds to the value of the speed of movement. Similarly, a radiation power is specified for a distance s. The speed of movement or the radiation power can be reduced, for example, in at least 2, preferably at least 3 stages and / or at most 6 stages, preferably at most 8 stages, and increased in at least 4, preferably at least 8, more preferably at least 12 and / or at most 16, preferably at most 20, more preferably at most 24 stages. In one embodiment, the speed of movement and the radiation power are changed in a different number of stages.It is particularly preferred that the radiant power is changed in twice the number of steps as the speed of motion. That is, a value for the radiant power is specified for a distance s = v ■ T, while a value for the speed of motion is specified over a distance s' = v ■ 2T.

[0225] Fig. 9, which bears a resemblance to Fig. 7, shows an embodiment in which the invention is advantageously applied in an object cross-section having two partial cross-sections that are exposed differently, i.e., in which one

[0226] EP 2379 / PK / 31 .07.2025 The energy input parameter has a different average value. Specifically, in Fig. 9, the two partial cross-sections are the inner region 52 and the contour region 51 of an exemplary rectangular object cross-section. Fig. 9 shows, by way of example, only some of the first and second partial trajectories 64 and 65, respectively, of a trajectory with which the build-up material in the inner region 52 is scanned. Transition trajectories 55 are also visible. For the sake of simplicity, no partial regions 53 are shown. These may or may not be present. The scanning of the contour region, which, unlike in Fig. 7, is shown with a larger area, is carried out with a partial trajectory 960, which runs parallel to the outer surface of the contour region 51. Although only one partial trajectory 960 is shown in this respect, several parallel partial trajectories can also be used to scan the contour region 51.

[0227] As mentioned in the introduction, different energy input parameters are generally assigned to the contour region 51 than to the interior region 52. This is due, among other things, to the fact that the contour region is surrounded by unsolidified build-up material and, after completion of the object, represents its outer surface. To prevent discontinuities in the solidified material resulting from changes in energy input parameters, a partial cross-sectional transition trajectory 955 is scanned in the embodiment shown in Fig. 9 for the transition from the interior region 52 to the contour region 51, on which the energy input parameters are modified. In other words, after scanning the interior region 52, the partial cross-sectional transition trajectory 955 is scanned, followed by the scanning of the partial trajectory 960 in the contour region 51.

[0228] Another embodiment, in which the invention is advantageously applied in an object cross-section having two partial cross-sections that are exposed differently, i.e., in which an energy input parameter has a different value on average, is described below in connection with Figs. 10 and 11.

[0229] EP 2379 / PK / 31 .07.2025 Fig. 10 shows a side section of an object segment to be produced, similar to the side view of object 2 in Fig. 1. The object segment shown in Fig. 10 has seven cross-sections in layers n+1 to n+7, with the upward arrow in the right part of the figure indicating the direction in which the layers are applied and solidified. In all layers, region 70, where no build-up material is solidified, is shown without fill and with a dashed line as its boundary.

[0230] Figure 10 also shows so-called downskin areas 62. These are parts of a cross-section that point downwards during the manufacturing of the object and below which the build-up material is not to be solidified. These areas are represented by slashes “ / ”. Also shown in Figure 10 are so-called upskin areas 61. These are parts of a cross-section that point upwards during the manufacturing of the object and above which the build-up material is not to be solidified. These areas are represented by slashes “\”. Figure 10 also shows cross-sectional areas 63, which are marked by circles “o”. These are areas that are neither underpinned nor covered by unsolidified build-up material and are subsequently also referred to as “sandwich areas”.

[0231] Since unconsolidated building material has a lower thermal conductivity, at least one energy input parameter is usually chosen differently in the areas with upskin surfaces and downskin surfaces compared to the "sandwich areas" 63.

[0232] It should also be mentioned that the description given in connection with Fig. 10 is somewhat simplified. In fact, areas are generally referred to as downskin areas if at least one of p layers below contains non-solidifying build-up material, where p is a non-zero natural number. Similarly, areas are generally referred to as upskin areas if at least one of p layers above contains non-solidifying build-up material, where p is a non-zero natural number.

[0233] EP 2379 / PK / 31 .07.2025 is a natural number. However, for the following description, it is irrelevant whether the value 1 or another value is chosen for p, in accordance with Fig. 10.

[0234] Fig. 11 shows a top view of an object cross-section to be solidified, for example, layer n+2 in Fig. 10. As in Fig. 7, the contour of the cross-section 50 is designated with the reference numeral 51 and the interior area with the reference numeral 52. The interior area consists of a "sandwich" area 63 and the downskin area 62, each with at least one different energy input parameter, for example, a changed radiation intensity, a changed movement speed, a changed beam diameter, or a changed beam shape or focus position.

[0235] For clarity, the transition trajectories 55 are not shown in Fig. 11; however, a partial cross-section transition trajectory 1155 is highlighted. This is scanned, for example, after the first and second partial trajectories 64 and 65 have been traversed in the "sandwich" region 63 and a transition to the downskin region 62 occurs, in which the first and second partial trajectories 64 and 65 are again scanned. The modification of energy input parameters can take place during the traversal of the partial cross-section transition trajectory 1155. Thus, the energy supply does not need to be interrupted for the transition to the partial cross-section with different energy input parameters, and discontinuities in the manufactured object can be avoided by gradually changing parameters along the partial cross-section transition trajectory 1155.

[0236] Fig. 12 shows another embodiment in which the invention is advantageously applied in an object cross-section that has two sub-cross-sections which are exposed differently, i.e., in which an energy input parameter has a different value on average. In Fig. 12, an object cross-section 1200 (the contour area is not shown) has a sub-cross-section 1201 of large extent and a sub-cross-section 1202 of small extent. It can be seen that the sub-trajectories 64, 65 in sub-cross-section 1201 have a significantly greater length than the sub-trajectories 64, 65 in sub-cross-section 1202. As a result, the temperature of the uppermost layer of the build-up material in sub-cross-section 1201 is on average higher than that in sub-cross-section 1202.

[0237] EP 2379 / PK / 31 .07.2025 Temperature of the uppermost layer of the build-up material in sub-section 1202. To counteract this, a number of energy parameters in sub-section 1202 can have a different average value than in sub-section 1201.

[0238] Again, the scanning process can proceed as follows: first, the first and second sub-trajectories 64, 65 in sub-cross-section 1201 are traversed; then, the sub-cross-section transition trajectory 1255 is traversed; and finally, the first and second sub-trajectories 64, 65 in sub-cross-section 1202 are traversed. If the energy input parameters for the transition to sub-cross-section 1202 along the sub-cross-section transition trajectory 1255 are modified, discontinuities in the finished component can be prevented or reduced.

[0239] Finally, it should be mentioned that a device 100 according to the invention for providing control data for an additive manufacturing device can be implemented not only by software components, but also by hardware components alone or by a combination of hardware and software. In particular, the interfaces mentioned in the present application do not necessarily have to be designed as hardware components, but can also be implemented as software modules, for example, if the input or output data can be taken over by other components already implemented on the same device, or only need to be transferred to another component via software. Likewise, the interfaces could consist of hardware and software components, such as a standard hardware interface that is specifically configured by software for the particular application.Furthermore, multiple interfaces can also be combined into a common interface, for example an input-output interface.

[0240] EP 2379 / PK / 31 .07.2025

Claims

Patent claims 1. A computer-aided method for providing control data for an additive manufacturing device (1) for producing a three-dimensional object (2), wherein the object is produced by means of the additive manufacturing device by applying a build material layer upon layer and solidifying the build material in a build plane (7) by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by scanning these locations with at least one beam (22) according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, wherein the method for providing control data comprises: a first step (S1) of accessing computer-based model data of at least one section of the object to be produced,a second step (S2) of generating at least one data model of an area of ​​a build-up material layer to be solidified for the production of at least one object section, which is assigned to an area of ​​a cross-section of the object, wherein the beam is moved along a trajectory at a velocity without interrupting the supply of radiation energy to the layer, wherein each of the trajectories has a number of first partial trajectories (64) and a number of second partial trajectories (65), wherein an angle between a first partial trajectory and a second partial trajectory following this first partial trajectory is greater than 90°, preferably greater than 120°, and less than or equal to 180°, and wherein the beam is moved alternately along first and second partial trajectories,wherein a transition trajectory is specified between a first partial trajectory and a second partial trajectory and between a second partial trajectory and a first partial trajectory, wherein a value for the speed of motion of the beam is specified for the movement of the beam along a number of the transition trajectories, which differs from the average value of the speed of motion of the, EP 2379 / PK / 31 .07.2025 beams along the first and second sub-trajectory associated with the respective transition trajectory, distinguishes, and a third step (S3) in which control data are provided according to at least one data model for generating a control data set for the additive manufacturing device, based on the data model generated in the second step (S2).

2. Method according to one of the preceding claims, wherein a monotone decrease and / or a monotone increase of an amount of the motion velocity or a constant amount of the motion velocity is specified for the movement of the beam along the transition trajectories.

3. A method according to claim 1 or 2, wherein for the successive movement of the beam along a first partial trajectory, along a transition trajectory and along a second partial trajectory the magnitude of the movement speed is specified such that the magnitude of the movement speed decreases monotonically during the movement along a segment of the first partial trajectory and / or along a segment of the transition trajectory and subsequently increases monotonically during the movement along a segment of the transition trajectory and / or along a segment of the second partial trajectory.

4. Method according to claim 2 or 3, wherein at the endpoint of the first partial trajectory the speed of movement has a value that is less than or equal to 75% of the mean value of the speed of movement specified for the movement along the first partial trajectory and / or at the starting point of the second partial trajectory the speed of movement has a value that is less than or equal to 85% of the mean value of the speed of movement specified for the movement along the second partial trajectory.

5. Method according to claim 3 or 4, wherein the distance along which the magnitude of the speed of motion increases monotonically is longer than the distance along which the magnitude of the speed of motion decreases monotonically. EP 2379 / PK / 31 .07.2025 6. A method according to one of the preceding claims, wherein a movement speed is specified for the movement along the transition trajectories, the value of which at each point of the transition trajectory is at least 20%, preferably at least 30%, particularly preferably at least 40% and / or at most 80%, preferably at most 70%, particularly preferably at most 60% of the value of the movement speed at the endpoint of the temporally preceding first or second partial trajectory.

7. Method according to one of the preceding claims, wherein a value for the beam energy density is specified for the movement of the beam along a number of transition trajectories, which differs from the average value along the first and second trajectories associated with the respective transition trajectory.

8. Method according to claim 6 or 7, wherein a monotonic change in beam energy density or a constant beam energy density is specified for the movement of the beam along the number of transition trajectories.

9. Method according to claim 7 or 8, wherein for the successive movement of the beam along a first partial trajectory, along a transition trajectory and along a second partial trajectory the value of the beam energy density is specified such that the value of the beam energy density decreases monotonically during the movement along a segment of the first partial trajectory and / or along a segment of the transition trajectory and subsequently increases monotonically during the movement along a segment of the transition trajectory and / or along a segment of the second partial trajectory.

10. Method according to claim 8 or 9, wherein the distance along which the radiation energy density increases monotonically is longer than the distance along which the radiation energy density decreases monotonically.

11. Method according to any one of claims 7 to 10, wherein at the endpoint of the first partial trajectory the beam energy density has a value which is less than or equal to EP 2379 / PK / 31 .07.2025 70% of the mean or maximum value of the beam energy density specified for movement along the first partial trajectory and / or at the starting point of the second partial trajectory the beam energy density has a value less than or equal to 80% of the mean or maximum value of the beam energy density specified for movement along the second partial trajectory.

12. Method according to any one of claims 7 to 11, wherein a minimum value of the beam energy density is specified for the movement along the transition trajectories, which is less than or equal to 50% of the value of the beam energy density at the end of the temporally preceding first or second partial trajectory.

13. A method according to any of the preceding claims, wherein for the movement of the beam along a trajectory it is specified that the extent of the impact area of ​​the beam on the surface of the build-up material at at least one location of one of the number of transition trajectories differs from the extent of the impact area of ​​the beam on the surface of the build-up material along the associated first partial trajectory and second partial trajectory, wherein preferably the minimum extent of the impact area of ​​the beam at at least one location of one of the number of transition trajectories is smaller than the minimum extent of the impact area of ​​the beam along the associated first and second partial trajectory.or wherein preferably the maximum extent of the impact area of ​​the beam at at least one point of one of the number of transition trajectories is smaller than the maximum extent of the impact area of ​​the beam along the associated first and second sub-trajectories.

14. Method according to one of the preceding claims, wherein in the data model the area to be solidified is assigned to a first partial cross-section and a second partial cross-section of the object section and it is specified that in the first partial cross-section at least one energy input parameter has a different value on average than in the second partial cross-section, EP 2379 / PK / 31 .07.2025 where in the data model at least one trajectory extends over the first and second sub-cross-section.

15. Method according to claim 14, wherein the first partial cross-section or the second partial cross-section is assigned a downskin area, which is defined in that in at least one of the cross-sections to be consolidated by p below, no consolidation of build-up material takes place, wherein p is a predetermined non-zero natural number, or an upskin area is assigned in that in at least one of the cross-sections to be consolidated by p above, no consolidation of build-up material takes place, wherein p is a predetermined non-zero natural number.

16. Method according to claim 14 or 15, wherein the data model specifies that the transition from the first partial cross-section to the second partial cross-section is achieved by scanning a partial cross-section transition trajectory, which is one of the transition trajectories.

17. Method according to claim 16, wherein a monotonic decrease and / or a monotonic increase of an amount of the motion velocity or a constant amount of the motion velocity is specified for the movement of the beam along the partial cross-sectional transition trajectory.

18. Method according to claim 16 or 17, wherein for the successive movement of the beam along the partial trajectory preceding the scanning of the partial cross-section transition trajectory, along the partial cross-section transition trajectory, and the partial trajectory following the scanning of the partial cross-section transition trajectory, the magnitude of the movement velocity is specified such that the magnitude of the movement velocity during the movement along a segment of the partial trajectory preceding the scanning of the partial cross-section transition trajectory EP 2379 / PK / 31 .07.2025 and / or decreases monotonically along a section of the transition trajectory and / or along a section of the sub-trajectory following the sampling of the sub-cross-section transition trajectory.

19. Method according to one of claims 16 to 18, wherein for the successive movement of the beam along the partial trajectory preceding the scanning of the partial cross-section transition trajectory, along the partial cross-section transition trajectory and the partial trajectory following the scanning of the partial cross-section transition trajectory, the magnitude of the movement speed is specified such that the magnitude of the movement speed increases monotonically during the movement along a segment of the partial trajectory preceding the scanning of the partial cross-section transition trajectory and / or along a segment of the transition trajectory and / or along a segment of the partial trajectory following the scanning of the partial cross-section transition trajectory.

20. Method according to one of claims 16 to 19, wherein a monotonic change in beam energy density or a constant beam energy density is specified for the movement of the beam along the partial cross-sectional transition trajectory.

21. Method according to one of claims 16 to 20, wherein for the successive movement of the beam along the partial trajectory preceding the scanning of the partial cross-section transition trajectory, along the partial cross-section transition trajectory and the partial trajectory following the scanning of the partial cross-section transition trajectory, the value of the beam energy density is specified such that the value of the beam energy density decreases monotonically during the movement along a segment of the partial trajectory preceding the scanning of the partial cross-section transition trajectory and / or along a segment of the transition trajectory and / or along a segment of the partial trajectory following the scanning of the partial cross-section transition trajectory. EP 2379 / PK / 31 .07.2025 22. Method according to one of claims 16 to 21, wherein for the successive movement of the beam along the partial trajectory preceding the scanning of the partial cross-section transition trajectory, along the partial cross-section transition trajectory and the partial trajectory following the scanning of the partial cross-section transition trajectory, the value of the beam energy density is specified such that the value of the beam energy density increases monotonically during the movement along a segment of the partial trajectory preceding the scanning of the partial cross-section transition trajectory and / or along a segment of the transition trajectory and / or along a segment of the partial trajectory following the scanning of the partial cross-section transition trajectory.

23. Method according to any one of claims 14 to 22, wherein a welding regime applied in the first partial cross-section is maintained during the transition from the first partial cross-section to the second partial cross-section.

24. Method according to any one of claims 1 to 23, wherein the last sampled partial trajectory or the first sampled partial trajectory of the trajectory runs parallel to at least a part of the contour of the object cross-section.

25. Additive manufacturing method for producing a three-dimensional object, wherein the object is produced by means of an additive manufacturing device by applying a build material layer upon layer and solidifying the build material in a build plane (7) by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by scanning these locations with at least one beam (22) according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, wherein the execution of the additive manufacturing method is controlled by a control data set generated using a method according to any of the preceding claims. EP 2379 / PK / 31 .07.2025 26. Device for providing control data for an additive manufacturing device for producing a three-dimensional object, wherein the object is produced by means of the additive manufacturing device by applying a build material in a build plane (7) by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by scanning these locations with at least one beam (22) according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, wherein the device for providing control data comprises: a data access unit (101) designed to access computer-based model data of at least one section of the object to be produced, a data model generation unit (102) designed toto generate at least one data model of an area of ​​a build-up material layer to be solidified for the production of at least one object section, which is assigned to an area of ​​a cross-section of the object, wherein motion vectors of the at least one beam in the build plane are specified in the data model for scanning locations of the area to be solidified along a number of trajectories, wherein the beam is moved along a trajectory without interrupting the supply of radiant energy to the layer, wherein each trajectory has a number of first sub-trajectories (64) and a number of second sub-trajectories (65), an angle between a first sub-trajectory and a second sub-trajectory following this first sub-trajectory is greater than 90°, preferably greater than 120°, and less than or equal to 180°, and wherein the beam is moved alternately along first and second sub-trajectories,wherein a transition trajectory is specified between a first partial trajectory and a second partial trajectory and between a second partial trajectory and a first partial trajectory, wherein a value of radiation intensity is specified for the movement of the beam along the transition trajectories which is less than that, EP 2379 / PK / 31 .07.2025 average value of the radiation intensity during the movement of the beam along the first and second sub-trajectories associated with the transition trajectory, and a control data provisioning unit (103) designed to provide control data in accordance with at least one data model generated by the data model generation unit (102) for the generation of a control data set for the additive manufacturing device.

27. Device for computer-controlled control of a number of energy input devices of an additive manufacturing device for the production of a three-dimensional object by means of the same, wherein the object is produced by means of the additive manufacturing device by applying a build material layer upon layer and solidifying the build material in a build plane (7) by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by scanning these locations with at least one beam (22) according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, wherein the device is designed such that solidification of the build material is specified by scanning locations of the area to be solidified along a number of trajectories,along which the beam is moved without interrupting the supply of radiant energy to the layer, wherein each trajectory has a number of first partial trajectories (64) and a number of second partial trajectories (65), wherein an angle between a first partial trajectory and a second partial trajectory following that first partial trajectory is greater than 90°, preferably greater than 120°, and less than or equal to 180°, and wherein the beam is moved alternately along first and second partial trajectories, wherein a transition trajectory is specified between a first partial trajectory and a second partial trajectory and between a second partial trajectory and a first partial trajectory, wherein a value of the radiant intensity is specified for the movement of the beam along the transition trajectories which is less than the average value, EP 2379 / PK / 31 .07.2025 the radiation intensity during the movement of the beam along the first and second sub-trajectories associated with the transition trajectory.

28. Additive manufacturing device for producing a three-dimensional object, wherein in the additive manufacturing device the object is produced by applying a build material layer upon layer and solidifying the build material in a build plane (7) by supplying radiant energy to locations in each layer that correspond to the cross-section of the object in that layer, by scanning these locations with at least one beam (22) according to a set of energy input parameter values ​​to effect a sintering or melting process along a number of trajectories, wherein the additive manufacturing device comprises: a layer application device (16) suitable for applying a layer of a build material to an existing, preferably selectively solidified, build material layer, an energy input device (20) suitable forto supply radiant energy to locations assigned to the cross-section of the object in a layer by scanning these locations with at least one beam (22) according to a set of energy input parameter values ​​along a number of trajectories, wherein the additive manufacturing device comprises a device according to claim 27 and / or is signal-connected to a device according to claim 27.

29. Computer program, comprising program code means for performing all steps of a method according to any one of claims 1 to 25, when the computer program is executed by means of a data processor, in particular a data processor cooperating with an additive manufacturing device. EP 2379 / PK / 31 .07.2025

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