Method and device for improving the quality of an object additively manufactured layer by layer

Abstract

The invention relates to a method for improving the quality of a layer-by-layer additively manufactured object (2), which is manufactured from a geometric model (M) by solidifying construction material in specified manufacturing layers (F, F+, F-) by means of an energy beam (22), said method comprising the following steps: providing model data (MD) comprising geometric data of the model (M); defining positions of the manufacturing layers (F, F+, F-), wherein two adjacent manufacturing layers (F, F', F -) lie parallel to one another at a distance A; selecting a number of critical structures (S) of the model (M) on the basis of the model data (MD) and / or an already manufactured object (2) and / or process control data (PS); generating a number of filling regions, wherein each filling region (B) comprises a surface in the position of a manufacturing layer (F), which completely covers at least one vertical projection of a sub-region of a selected critical structure (S) between the positions of said production layer (F) and an adjacent production layer (F+, F-), and filling regions (B) of contiguous sub-regions of a selected critical structure (S) overlap in positions of adjacent manufacturing layers (F, F+, F-) in a vertical projection; using the filling regions (B) to modify the model (M) and / or to modify layer data (SD) of the model (M) and / or control data in order to manufacture an object (2) on the basis of the model (M). The invention also relates to a device, layer data, a control unit and a manufacturing device.

Description

[0001] Method and device for improving the quality of an additively manufactured object layer by layer

[0002] The invention relates to a method and a device for improving the quality of an additively manufactured object layer by layer, preferably for generating layer data or control data. The invention also relates to corresponding layer data, a control device for a manufacturing apparatus for the additive manufacturing of a component, and a manufacturing apparatus.

[0003] In additive manufacturing, the model, which may have been created in a CAD program or exists as a scan of a real object, is often available as a surface model or a solid model. The object is then additively manufactured according to this model, i.e., through the successive solidification of layers of (e.g., powdered) build-up material.

[0004] Since manufacturing occurs layer by layer, the model is sliced ​​into layers using a so-called "slicer," and layer data and control data are then derived from these layers. This process is well-known and can include the arrangement of hatch lines as well as the specification of beam parameters. In the following, the term "slicing" refers to the definition of manufacturing levels and the creation of intersections between the model and these levels.

[0005] The decomposition into layers is generally performed by defining manufacturing layers and finding the intersections of the model with these individual manufacturing layers. The manufacturing layers are virtual layers that correspond to the later object layers. They are typically parallel planes at regular intervals. In a manufacturing process where powdered build material is solidified by an energy beam, the distance between two manufacturing layers can be less than 0.1 mm (a typical layer thickness is, for example, 30 pm - 80 pm for objects made from radiation-solidified powder). This distance ideally corresponds to the layer thickness (also called "layer thickness") of at least some areas of the later object and / or the thickness of a layer of build material. The intersection simply indicates which areas of a manufacturing layer correspond to the model.It is important to note that a slicer typically does not consider a volume; rather, the manufacturing layers are two-dimensional layers in three-dimensional space. During the additive manufacturing process, hatch lines, for example in the form of an exposure pattern, are arranged, particularly within the interface between a manufacturing layer and the model. With very delicate objects or objects with intricate structures, this can lead to small (quasi-one-dimensional) interfaces, especially in structures with very thin walls. Due to the small area of ​​this interface within the manufacturing layer, a sufficient number of hatch lines cannot be placed within the layer to ensure flawless manufacturing of the object in the vertical direction. For example, a thin surface structure intended for use as a heat exchanger might have holes in some places.

[0006] This problem can be countered by only allowing thick structures in a model. However, this is not a solution if delicate structures are desired.

[0007] It is an object of the present invention to provide a method and a device for improving the quality of an additively manufactured object layer by layer, preferably for generating layer data or control data, such layer data, a control device for a manufacturing device for the additive manufacturing of a component and a manufacturing device with which the disadvantages described above are avoided.

[0008] This problem is solved by a method according to claim 1, a device according to claim 10, layer data according to claim 12, a control device according to claim 13 and a manufacturing device according to claim 14.

[0009] A method according to the invention serves to improve the quality of an additively manufactured object produced layer by layer, which is manufactured from a geometric model by solidifying build material in defined manufacturing layers using an energy beam. The method comprises the following steps:

[0010] - Providing model data, including geometric data of the model,

[0011] - Defining the positions of the production layers, where two adjacent production layers are parallel to each other at a distance A,

[0012] - Selecting a number of critical structures of the model based on the model data and / or a previously manufactured object and / or process control data, - Generating a number of fill areas, each fill area comprising an area at the position of a manufacturing layer, which fully covers at least one vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and an adjacent manufacturing layer, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection (i.e., only if such fill areas exist on two adjacent manufacturing layers).

[0013] - Using the fill areas to modify the model and / or to modify or create layer data of the model and / or control data to manufacture an object based on the model.

[0014] As a first approximation, the method can generally be used to improve the quality of a layer-by-layer additively manufactured object, which is produced from a geometric model by solidifying build material in defined manufacturing layers using an energy beam. It should be noted that the improvement takes place before the object is manufactured, which is why it could also be referred to as the "object to be manufactured." However, the quality improvement is always evident in a subsequently manufactured object. The method allows for modification of the model before slicing to improve its layer-by-layer decomposition, modification of the model or the intersections during slicing, or the correction of defects in the sliced ​​model before the object is manufactured. In each of these cases, the basic principle of the method according to the invention provides an improvement in the subsequently manufactured object.

[0015] First, the model data must be known. This always includes the geometric data of the model. The model can, for example, exist as a CAD model in the form of a union of three-dimensional basic structures, or as a surface model (e.g., as an STL file). Essentially, any data set that represents the eventual object can be considered a model.

[0016] To easily understand the following explanations, it is helpful to imagine a 3D volume or surface model. This model should contain delicate structures whose thickness is less than the layer thickness A of the final object. It should be noted that while their thickness in the final object will be at least as thick as a component layer, such thin structures in the model can lead to holes in the object without this method. Regarding the delicate structures, it is easy to imagine that a mathematical function has been used to generate a three-dimensional structure with a very small wall thickness (the walls can also consist of surfaces) within the object.

[0017] In addition to the model, manufacturing layers are defined that should correspond to the later layers in the object's construction ("process layers"). Since the method can be applied before, during, and after slicing, the manufacturing layers do not necessarily need to be present (as they are during slicing); only their positions need to be known. For example, the statement "All points in the XY plane for which Z = N ≤ 0.01 mm with the natural number N (including 0) up to the height of the model" may suffice. If a situation is considered after slicing, the model is already decomposed into manufacturing layers, meaning the positions of the manufacturing layers were already defined during slicing. The manufacturing layers are all parallel to each other at a distance A. In the example above, A would be 0.01 mm. It should be noted that A is typically very small, usually less than 0.1 mm.

[0018] In the model, a number of critical structures are selected; this can be a single critical structure or multiple critical structures. This is done using the available model data and / or a previously manufactured object and / or process control data. For example, it can be checked where a defect exists in a previously manufactured object and the area of ​​the defect in the model can be selected as a critical structure. Alternatively, the model can be examined for thin structures or, after a slicing process, for small or thin cut lines or surfaces in the manufacturing layers. The solidification paths of process control data can also be checked for defects, such as excessively large gaps. Generally, any structure below a specified thickness can be considered a critical structure, but structures can also be analyzed in more detail, e.g.,Only if they lead to a defect in the object. This is particularly the case if a thin structure with an extent in Z (direction of the surface normal of the manufacturing layers) smaller than A runs between two manufacturing layers, whereby a structure that intersects several manufacturing layers can also be selected as a critical structure. It should be noted that the entire model can also be considered a critical structure. For example, the model may have a large area representing a gyroid or a lattice with thin walls. Here, each wall or the entire gyroid / lattice could be considered a critical structure. The component itself could also be considered a critical structure, at least if the substantial part consists of this gyroid / lattice. However, it is preferable to choose the critical structures to be relatively small, so that they penetrate at most 100, and in particular at most 20, manufacturing layers.This allows for a simple, variable treatment of different types of critical structures.

[0019] A critical structure is preferably defined as follows:

[0020] Generally, this should be any part in the model that would lead to an unintended defect in the manufactured object. Since this typically manifests as breaks or holes, this can be specified as follows: a critical structure is preferably a closed structure (planar structure) where, with respect to two adjacent manufacturing layers, the intersections projected in the direction of the surface normal of the manufacturing layers are not closed (a structure with a hole or break), or where a node exists in the model but not in the projected intersections. There are several ways to verify this. A critical structure in the model is any structure that:

[0021] - with an extent D in Z (surface normals of the manufacturing layers) less than the distance A between two adjacent manufacturing layers, preferably at least if this runs at an angle less than 90° arcsin (D / A), and / or

[0022] - whose projection in Z on a manufacturing layer represents a closed surface, wherein the corresponding projection of whose intersections with manufacturing layers has a hole or a break, and / or

[0023] - whose equivalent in a previously manufactured object according to the model has a hole or a break, and / or

[0024] - whose intersections of adjacent manufacturing layers, when projected in the Z direction onto a manufacturing layer, have a distance between them.

[0025] A critical structure can also be the entire model or at least a predetermined sub-area of ​​a model, e.g., a delicate interior. For example, due to the shape of the object or the model, intersections of several (all) pairs of adjacent manufacturing layers may have a distance between them when projected in the Z-direction onto a manufacturing layer.

[0026] It can be advantageous to consider more than two manufacturing layers as described above when selecting critical structures.

[0027] It should be noted that selecting a critical structure in the model does not necessarily mean that this structure must be located within the model itself or between manufacturing layers. A critical structure can also be selected simply by choosing an area (especially on or between) the positions of two manufacturing layers. Alternatively, intersection points (or surfaces) in two adjacent manufacturing layers can be selected as the critical structure, or the area between these intersection points (or surfaces). The crucial factor here is when the critical areas are selected (before, during, or after slicing) and which instance is used to select them. For example, a typical slicer cannot "recognize" what lies between two layers, but only what lies precisely within a layer, namely the intersection points or surfaces.In a CAD program, however, one can, for example, specifically search for structures that fall below a certain thickness in Z and select these as critical structures.

[0028] If at least one critical structure is selected (e.g., due to intersection lines in two adjacent manufacturing layers), then at least one fill area is generated. Often, fill areas are generated in adjacent manufacturing layers, for example, if an elongated critical structure runs diagonally through the manufacturing layers. These fill areas should not be confused with the intersections that are created during slicing anyway. Each fill area encompasses a surface at the position of a manufacturing layer, which completely covers at least one vertical projection of a portion of a selected critical structure between the positions of this manufacturing layer and an adjacent manufacturing layer.

[0029] It should be noted that the fill areas for a manufacturing process, like the other cut surfaces of a manufacturing layer, are also filled with a pattern of hardening paths. Conversely, an additional pattern of hardening paths automatically represents a fill area. A fill area can therefore be, for example, an additional cut surface on a manufacturing layer, part of a model, a three-dimensional object (which can be cut by a manufacturing layer), or a pattern of hardening paths.

[0030] It should be noted here that "vertical" refers to the Z-direction, or the direction of the surface normals of the manufacturing layers. The term "horizontal" means parallel to the manufacturing layers. An object is built vertically, and its component layers lie horizontally.

[0031] It should be noted that a fill area does not necessarily have to be a surface on a manufacturing layer, but can also be an area within a model that modifies the model. The fill area can also be an additional area (surface or volume) that is included on a manufacturing layer to create intersections. Regardless, every fill area must encompass a surface at the location of a manufacturing layer. The fill area must therefore be designed so that the manufacturing layer intersects it at least with this surface. This can be achieved, for example, by placing a solid accordingly. Alternatively, a group of points (or a surface) corresponding to the fill area can be placed precisely on this manufacturing layer. As will be explained in more detail later, a separate fill area can be created for this purpose (i.e., a solid or...(the points are regenerated), part of the model is distorted accordingly, the model (at this point) is given a larger volume (“inflated”) or the model is represented in the form of volume blocks.

[0032] This area cannot be chosen arbitrarily. It is closely linked to the critical structure. Specifically, this area must be a vertical projection (i.e., in the Z-direction or in the direction of the surface normals of the manufacturing layers) of a sub-region of a selected critical structure. This critical structure lies between the positions of the manufacturing layer under consideration and an adjacent manufacturing layer. Thus, a critical structure between these two adjacent manufacturing layers is considered, and a portion of this structure is projected onto the manufacturing layer in question. The fill area must then cover (enclose) this projection; that is, the fill area must be at least equal to this area, but can also be larger.

[0033] It is important to note that “viewing” a critical structure and “projecting” a part of the critical structure do not necessarily constitute steps of a method according to the invention that must be actively performed. It is possible to create the fill areas in such a way that the projection of a part of a critical structure within the fill area is included, for example, due to the properties of the fill area itself or due to a step performed to create the fill area. Whether the step includes the projection of a part of a critical structure between two adjacent manufacturing layers depends on how the fill area is created.

[0034] Normally, this fill area is also larger than the surface (the projection), because the process additionally requires that fill areas of contiguous sub-regions of a selected critical structure overlap in vertical projection at positions of adjacent manufacturing layers. This means that a projection of the other part of the critical structure onto the adjacent manufacturing layer must also be performed, and another fill area must be created from this (which may have already happened in a previous step, for example). These two fill areas must then overlap in vertical projection (i.e., in the Z-direction or in the direction of the surface normals of the manufacturing layers). A thin structure running between two manufacturing layers will therefore, for example, be partially projected onto the upper manufacturing layer and partially onto a lower one.These projections result in two surfaces, one on the upper manufacturing layer and one on the lower layer. Fill areas are then created on these manufacturing layers. Since the surfaces were formed from a single, continuous structure, the fill areas must overlap (especially in vertical projection). If the two surfaces do not overlap (in vertical projection), the fill areas must be extended until they do.

[0035] For example, as will be explained in more detail later, custom fill areas can be created (i.e., a solid or points can be regenerated). Alternatively, a portion of the model can be distorted, taking care to ensure proper overlap. For instance, a saddle between two manufacturing layers can be extended onto one of the layers. The model can also be given a larger volume ("inflated") at this point, so that the surfaces from the "inflated" area overlap in the two adjacent manufacturing layers. The model can also be represented as volume blocks with a minimum height of A. In this case, each volume block is intersected by a manufacturing layer. However, it is crucial to ensure proper overlap in this scenario.

[0036] In practice, all surfaces can first be created at the positions of the production layers, and then, by considering the respective neighbors of all production layers, the fill areas can be created so that the overlaps are optimally distributed across the fill areas.

[0037] The fill areas are then used to modify the model and / or to modify or create layer data of the model and / or control data for manufacturing an object based on the model. For example, the model can be modified in the area of ​​critical structures before or during slicing. It is also possible to modify the manufacturing layers or layer data during slicing. Ultimately, even an already sliced ​​model can be optimized by subsequently changing the layer data or control data. The modified model, layer data, or control data can then be output for further processing or application in the subsequent manufacturing of the object.

[0038] An apparatus according to the invention serves to improve the quality of an additively manufactured object produced layer by layer, which is manufactured from a geometric model by solidifying build material in defined manufacturing layers using an energy beam. The apparatus comprises the following components:

[0039] - a data interface designed to receive model data, including geometric data of the model,

[0040] - a fixing unit designed to fix positions of the manufacturing layers, wherein two adjacent manufacturing layers are parallel to each other at a distance A,

[0041] - a selection unit designed to select a number of critical structures of the model based on the model data and / or a previously manufactured object and / or process control data,

[0042] - a fill area unit designed to generate a number of fill areas, wherein each fill area comprises an area at the position of a manufacturing layer which fully covers at least one vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and a manufacturing layer adjacent to it, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection,

[0043] - a modification unit designed to use the fill areas to modify the model and / or to modify or create layer data of the model and / or control data to manufacture an object based on the model.

[0044] The function of the device's components has already been described. The device is preferably designed to carry out a method according to the invention. The data interface (or another one) can be used to output the results of the modification unit.

[0045] The layer data according to the invention has been created using a method according to the invention, preferably by means of a device according to the invention. It differs from conventional layer data in that it additionally depicts structures that lie between two manufacturing layers in the model and would therefore not normally be depicted.

[0046] A control device according to the invention serves a manufacturing apparatus for the additive manufacturing of a component in a manufacturing process in which build material, preferably a plastic powder or metal powder, is built up layer by layer in a build area, and selective solidification of the build material takes place between the application of two material layers by irradiating the build material with at least one energy beam. The control device comprises a device according to the invention.

[0047] A manufacturing device according to the invention serves for the additive manufacturing of at least one object in an additive manufacturing process. It comprises at least:

[0048] - a feeding device for applying layers of building material in a build area into a process chamber,

[0049] - an irradiation device for selectively solidifying build-up material between the application of two material layers by irradiation with at least one energy beam, as well as

[0050] - a control device according to the invention.

[0051] The invention can be implemented, in particular, in the form of a computer unit with suitable software. The computer unit can, for example, comprise one or more cooperating microprocessors or the like. In particular, it can be implemented in the form of suitable software program components within the computer unit. A largely software-based implementation has the advantage that even previously used computer units can be easily retrofitted by a software or firmware update to operate according to the invention. In this respect, the problem is also solved by a corresponding computer program product with a computer program that can be directly loaded into a memory device of a computer unit, containing program sections to execute all steps of the method according to the invention when the program is run in the computer unit.In addition to the computer program itself, such a computer program product may include additional components such as documentation and / or additional components, including hardware components such as hardware keys (dongles, etc.) for using the software.

[0052] For transport to the computer unit and / or for storage on or in the computer unit, a computer-readable medium, such as a memory stick, a hard drive or other portable or permanently installed data carrier, can be used, on which the program sections of the computer program that can be read and executed by a computer unit are stored.

[0053] Further, particularly advantageous embodiments and developments of the invention result from the dependent claims and the following description, wherein the claims of one claim category may also be further developed analogously to the claims and description parts of another claim category and, in particular, individual features of different embodiments or variants may be combined to form new embodiments or variants.

[0054] According to a preferred embodiment of the method, the selection of the number of critical structures is made according to one or more of the listed points:

[0055] - by (directly) specifying a number of critical structures in the model, e.g., by manually searching for critical structures in the model and specifying them for the procedure,

[0056] - by identifying a number of critical structures according to predefined criteria in the model, which can be done in particular automatically, whereby structures with predefined parameters are sought or structures whose dimensions fall below predefined limits are sought, and / or

[0057] - by comparing the model with the sliced ​​model, where a critical structure in the model forms a closed surface and in the sliced ​​model has a wall thickness below a specified minimum thickness or has a hole or gap,

[0058] - by comparing the model with an object created from the model, where a critical structure in the model forms a closed surface and in the object has a wall thickness below a specified minimum thickness or has a hole or gap,

[0059] - by determining intersection points (individual points or groups of points in the form of intersection surfaces) of a continuous structure in the model with the positions of two adjacent manufacturing layers, wherein in the case that the intersection points of adjacent manufacturing layers have a hole or gap in plan view (i.e. in vertical projection) and the structure in the model does not

[0060] Preferably, a critical structure has a thickness less than four times the distance between the manufacturing layers 4A; more preferably, the thickness is less than A. In particular, a critical structure is a two-dimensional structure and preferably extends over a distance greater than A between two manufacturing layers without touching them.

[0061] Preferably, a fill area is generated from a sub-area of ​​a critical structure that extends more than a predetermined distance within the space between the positions of two adjacent manufacturing layers and / or

[0062] - represents an intersection with another structure with a thickness less than A within the space between the positions of two adjacent manufacturing layers.

[0063] Such critical structures are predisposed to later errors in the object.

[0064] According to a preferred embodiment of the method, a number of critical structures of the model are selected, and the model is modified based on the fill regions (before or during slicing). Preferably, this is done before generating layer data of the model.

[0065] When generating a fill area, layer areas are preferably created at the positions of the manufacturing layers in the model, corresponding to the respective fill areas. In a simple case, surfaces are created or inserted where the slicer can later recognize them. This has the advantage that modifications are only made where they are important for the slicing process.

[0066] Alternatively or additionally, preferably, when generating a fill area, the critical structure is recreated from voxels (or blocks) with predetermined dimensions, preferably wherein each voxel (or block) intersects the position of a manufacturing layer and / or each voxel (or block) has a height of at least A. It is also possible to generate the fill area in the form of voxels (blocks) or to recreate the fill area from voxels (blocks). For example, the fill area can be generated by assigning further voxels (blocks) to a critical structure. This has the advantage that a critical area can be compensated for with very little computational effort.

[0067] Alternatively or additionally, when generating a fill area, a critical structure is deformed and / or shifted in such a way that it results in overlapping fill areas at a number of positions on adjacent manufacturing layers (in top view). The critical structures can be extended so that they cover adjacent manufacturing layers accordingly and / or are shifted onto manufacturing layers. This has the advantage that a model can be optimally modified for a slicing process.

[0068] Preferably, the model is modified such that adjacent fill areas in projection have a predetermined overlap at positions of neighboring manufacturing layers (i.e., a vertical projection in plan view). In particular, layer areas are made correspondingly large and / or voxels are designed or arranged accordingly. Alternatively or additionally, it is also preferred that a critical structure is deformed accordingly.

[0069] According to a preferred embodiment of the method, at least one identified critical structure of the model is extended, preferably wherein the horizontal and / or vertical extension of a sub-area of ​​the critical structure depends on its slope. Preferably, a vertical extension of the critical structure occurs at a low slope (below a predetermined limit), and a horizontal extension occurs at a high slope (above the predetermined limit). This approach has the advantage that the critical structure is modified only as much as necessary, while still ensuring sufficient overlap of the fill areas of adjacent manufacturing layers. At a low slope, vertical extension is more significant, while at a high slope, horizontal extension is more significant.

[0070] The (vertical and / or horizontal) extension of the model can be achieved by extending a critical structure by an amount in one direction (preferably in the direction parallel and / or perpendicular to the manufacturing layers). It is particularly preferred that the critical structure be extended horizontally (i.e., in the direction parallel to the manufacturing layers) by an amount corresponding to a focus size of the energy beam (on the respective build plane). For this purpose, the critical structure is preferably extruded horizontally by at least half the focus size in opposite directions or by at least one focus size in one direction.

[0071] Alternatively or additionally, it is preferred that the critical structure is extended vertically by an amount that preferably corresponds to at least the distance A, in particular wherein the critical structure is extruded vertically by at least A / 2 in opposite directions or at least A in one direction. If a structure has at least the height A, it is always intersected by at least one manufacturing layer.

[0072] When a critical structure is extended, it is possible to extend the entire critical structure (e.g., across multiple layers). The extension of an entire critical structure can be achieved, for example, by a (rigid) displacement of an outer surface of the critical structure by a specified amount in one direction. This displacement can occur in only one direction or in opposite directions. An "outer surface of the critical structure" is an (idealized) surface that encompasses points in the model at the position of the critical structure for which no other point (within a predetermined length) can be found in the model in the direction of the critical structure's extension or in the direction of the displacement of the outer surface itself. The extension of an entire critical structure can also be achieved by rotating or tilting the outer surface around a fixed point in three-dimensional space.This results in a different distance between the original and the rotated or inclined outer surface in each manufacturing layer. Alternatively, when extending a critical structure, it is possible to select (intersection) points and / or (intersection) surfaces of a critical structure in the manufacturing layer and extend the model at the position of these (intersection) points and / or (intersection) surfaces. The extension of the model at these positions can be achieved by (rigidly) translating the (intersection) points or (intersection) surfaces by a specified amount in one direction. The translation can be in only one direction or in opposite directions. (Intersection) points or (intersection) surfaces can be translated by the same amount in different (e.g., in all) manufacturing layers at the position of the critical structure, or they can be translated by different amounts in different manufacturing layers.

[0073] When displacing an outer surface of the critical structure horizontally (parallel to the manufacturing layers) or vertically (perpendicular to the manufacturing layers), and when displacing (intersection) points and (intersection) surfaces of a critical structure, it is preferred that the displacement be equal to the focus size or the distance A. It is further preferred that the outer surface and the (intersection) points / surfaces are displaced horizontally by half the focus size and vertically by a distance A / 2 in opposite directions.

[0074] Preferably, a plurality of points on the critical structure are defined, and for each point, a trajectory angle of the critical structure is determined. If the angle is shallower to the horizontal than to the vertical, a vertical extension of the critical structure is made at that point. If the angle is shallower to the vertical than to the horizontal, a horizontal extension of the critical structure is made at that point.

[0075] Preferably, the procedure includes the following additional steps:

[0076] - Creating layer data of the model from the intersection surfaces (intersections) of the model with planes at the positions of the manufacturing layers,

[0077] - Output of the shift data, preferably wherein control commands for the manufacture of an object according to the shift data are generated from the shift data.

[0078] This occurs during normal slicing, with the difference that the filled areas are now also taken into account, e.g., as additional cutting surfaces or in a specially modified model. It is preferred that the layer data be generated from a modified model, as described above.

[0079] It should be stated again here that the fill areas can be added to the model (modification of the model), form an independent group that can be sliced ​​together with the model (and combined with the model to create the intersections in the manufacturing layers), or can already form areas (intersections) in the manufacturing layers.

[0080] According to a preferred embodiment of the method, layer data is generated from the intersections of several fill areas with planes at the positions of the manufacturing layers. The fill areas are surfaces or volumes at the positions of the manufacturing layers and are not part of the model. Preferably, additional fill areas are considered during and / or after the generation of layer data from the model's intersections with planes at the positions of the manufacturing layers. Therefore, the model does not necessarily need to be modified, as the fill areas can be considered separately.

[0081] Preferably, a corresponding fill area is generated by extending at least one identified critical structure of the model, preferably wherein the horizontal and / or vertical extension of a sub-area of ​​a critical structure depends on its slope. Thus, preferably an extension body is created based on at least one identified critical structure of the model, wherein, for an extension body, the volume of the relevant critical structure is increased at least in the direction of the spacing between the positions of the manufacturing layers to such an extent that it touches or penetrates at least one plane at a position of an adjacent manufacturing layer. It is preferred that the horizontal and / or vertical extension of a sub-area of ​​a critical structure depends on its slope. The extension body can then be sliced ​​at the position of the critical structure.

[0082] Alternatively or additionally preferably, a corresponding fill area is generated by moving a copy of a number of points of the model in each critical structure to at least one of the adjacent manufacturing layers, preferably the nearest one.

[0083] Alternatively or additionally, a corresponding fill area is generated by creating layer areas on the manufacturing layers that correspond to the fill areas in question. This is preferably done by vertically projecting the sub-areas onto the manufacturing layers. In practice, for example, a number of points can be "projected" onto one manufacturing layer so that a fill area is generated in that other layer. Alternatively, some of the points can be copied onto one manufacturing layer and another part onto an adjacent manufacturing layer, and additional points can be created as overlap areas in these manufacturing layers.

[0084] Alternatively or additionally, preferably, a corresponding fill area is generated by forming blocks with a minimum height of A at the position of sub-areas of a critical structure. It is preferred that each block fills the space between two sections of the critical structure with the positions of two adjacent manufacturing layers. These blocks can then be sliced, or the fill area can be formed by the blocks themselves.

[0085] Alternatively or additionally, preferably, a corresponding fill area is generated by reshaping the critical structure from voxels with predetermined dimensions. It is preferred that each voxel intersects the position of a manufacturing layer. These voxels can then be sliced, or the fill area can be formed by the voxels themselves.

[0086] According to a preferred embodiment of the method, after the layer data has been output, control commands are modified by adding additional consolidation paths (i.e., scan lines or hatch lines). This is preferably done according to the following steps:

[0087] - Identifying critical structures in the model,

[0088] - Identifying critical areas in the layer data where a critical structure deviates from its shape in the model, has holes, or is separated into substructures,

[0089] - Creating control commands to manufacture an object from the layer data, adding solidification paths in the critical areas, designed to fill a hole in the critical area in question or to join substructures together,

[0090] - Output of tax data.

[0091] According to a preferred embodiment of the method, after a slicing process, cut areas in manufacturing layers are identified that have an area below a predefined threshold, i.e., are very small. These cut areas are then defined as critical areas. It is preferably checked whether cut areas in two adjacent manufacturing layers belong to a coherent structure in the model. In this case, both cut areas are jointly assigned to a critical structure. Thus, for example, if a thin surface runs diagonally between two manufacturing layers in the model, it will cut them at different points. Small cut surfaces are then identified (the surface only cuts the manufacturing layers in very small areas) that belong to a common structure (the surface) in the model.The two cut areas are then preferably considered contiguous sub-areas of a selected critical structure. Fill areas are then created around these cut areas in both manufacturing layers, overlapping in vertical projection.

[0092] The following considers an embodiment in which intersections (intersection surfaces) of adjacent manufacturing levels are considered to define critical structures.

[0093] According to a particular aspect already mentioned above, the filling areas are created by considering the intersection areas of the critical structures with adjacent manufacturing layers and creating filling areas (at least) in these manufacturing layers that overlap each other (in top view).

[0094] The preferred method, as mentioned, serves to improve the quality of a layer-by-layer additively manufactured object, which is produced from a geometric model by solidifying build material in defined manufacturing layers using an energy beam. The method comprises the following steps:

[0095] - Providing model data including geometric data of the model (so),

[0096] - Defining the positions of the manufacturing layers, where two adjacent manufacturing layers are parallel to each other at a distance A (so).

[0097] - Selecting a number of critical structures of the model based on the model data and / or a previously manufactured object and / or process control data. It should be noted that a critical structure can indeed be selected within the model itself, e.g., in a CAD program or a program that searches for critical structures in the model based on predefined parameters.

[0098] In a preferred variant of the method, which can be performed directly during slicing when examining the manufacturing layers or after slicing, a critical structure is selected based on intersections, cut lines, or cut surfaces in adjacent manufacturing layers (at least two, but potentially more). Intersections or cut lines can be automatically identified, for example, based on their lack of extent (they then originate from lines or surfaces in a CAD model). Thin, three-dimensional structures can be identified based on the dimensions of the resulting cut surfaces. For clarity, the relevant intersections, cut lines, or cut surfaces are referred to below as "critical cutting features."It should be noted that, since the cutting elements are all intersections of the model (defined by the model data) and the manufacturing layers, they are naturally also based on the model data.

[0099] A critical structure is defined based on (in plan view) adjacent critical cutting elements. Since the positions of manufacturing layers are very close to each other in practice, the critical cutting elements are usually not far apart either. Therefore, it is preferred that, for a first critical cutting element at the position of a manufacturing layer, a search is made within a predefined radius around this first critical cutting element for (at least) one second critical cutting element at the position of an adjacent manufacturing layer, and a second critical cutting element found within this radius is considered a "partner" of the first critical cutting element. A critical structure is then assumed to exist between these (at least two) critical cutting elements.

[0100] A critical structure can also be assumed where surfaces of adjacent manufacturing layers do not overlap or overlap too little. Here, prior knowledge of the structure's shape could be helpful, or at least prior knowledge that two surfaces belong to a connected structure. Therefore, regarding the shape of the infill area, one can assume the extent of the (potentially missing) overlap of the surfaces of the critical structures in adjacent manufacturing layers.

[0101] It is possible, and indeed preferred, to identify a critical structure by directly determining the extent of the cross-sectional areas and using the overlap of the projections of the cross-sectional areas of adjacent manufacturing planes as a benchmark. If this overlap is insufficient, a critical structure is identified at that point, and a corresponding fill area is created. The overlap between cross-sectional areas will essentially never be sufficient; therefore, it is preferred to assume a critical structure at a cross-sectional area within a manufacturing plane. In a preferred method according to the invention, the selection of a number of critical structures of the model is based not only on the model data and / or an already manufactured object and / or process control data, but also on an overlap, particularly a lack of overlap, of cross-sectional areas of the model in two adjacent manufacturing layers.

[0102] - Generating a number of fill areas, each fill area comprising an area at the position of a manufacturing layer which fully covers at least one vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and a manufacturing layer adjacent to it, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection.

[0103] Preferably, a first filling area comprises a first surface at the position of a first manufacturing layer (the first filling area includes the first critical cutting element) and a second filling area comprises a second surface at the position of a second manufacturing layer (the second filling area includes the second critical cutting element).

[0104] The first surface (in the first manufacturing layer) covers part of the area between the first critical cutting element and the second critical cutting element, and the second surface (in the second manufacturing layer) covers another part of the area between the first critical cutting element and the second critical cutting element, so that the area between the first critical cutting element and the second critical cutting element is completely covered by the first and second surfaces when viewed from above, and both surfaces overlap (in plan view). The two surfaces preferably overlap with a predetermined degree of coverage (at least partially).

[0105] - Using the fill areas to modify the model and / or to modify or create layer data of the model and / or control data to manufacture an object based on the model.

[0106] The steps of selecting the number of critical structures and generating the number of filling regions of the method according to the invention can also preferably be modified for this embodiment as follows:

[0107] - Selecting a number of critical structures of the model based on the model data and the intersections of the model data with the manufacturing layers, where a critical structure is a pair of intersection surfaces in adjacent manufacturing layers which fall below a specified area measure and / or whose union in vertical projection has a gap or hole and thus differs from the model.

[0108] - Generating a number of fill areas, each fill area comprising a surface at the position of a manufacturing layer which fully covers at least a vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and a manufacturing layer adjacent to it, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection, wherein, starting from the intersection surfaces, fill areas are created in the adjacent manufacturing layers, the union of which at least fully covers the projection of the critical structure of the model in question.

[0109] As an alternative to the above-mentioned selection of the critical structure, the number of critical structures can also be selected according to one or more of the listed points:

[0110] - by (directly) specifying a number of critical structures in the model,

[0111] - by comparing the model with the sliced ​​model,

[0112] - by comparing the model with an object created from the model.

[0113] A critical structure is preferably one with a thickness less than the distance A between adjacent manufacturing layers. In particular, a critical structure is a two-dimensional structure and preferably extends over a distance greater than A between two manufacturing layers without touching them. It preferably intersects adjacent manufacturing layers in (in plan view) separate surface areas.

[0114] According to a preferred embodiment of the method, a number of critical structures of the model are selected, and the model is modified based on the fill regions (before or during slicing). Preferably, this is done before generating layer data of the model.

[0115] According to an alternative preferred embodiment of the method, a number of critical structures of the model are selected, and layer data from manufacturing layers (i.e., essentially intersections with the model) are modified based on the fill areas (during or after slicing). Preferably, this is done before generating layer data of the model.

[0116] Preferably, when generating a fill area, layer areas are created at the positions of the manufacturing layers in the model, corresponding to the respective fill areas. In a simple case, areas are created or inserted where the slicer can later recognize them. This has the advantage that modifications are only made where a slicer can detect them. According to a preferred embodiment of the method, after a slicing process, cut areas in manufacturing layers are identified that have an area below a predefined threshold, i.e., are very small. These cut areas are then defined as critical areas. Alternatively, it can be checked whether (in top view) separate cut surfaces in adjacent manufacturing layers in the model belong to a coherent structure.In general, preference should be given to checking whether cut areas in two adjacent manufacturing layers belong to a coherent structure in the model, whose combined shape (in vertical projection) differs from the vertical projection of the corresponding structure in the model.

[0117] In this case, both intersection areas are jointly assigned to a critical structure. For example, if a thin surface runs diagonally between two manufacturing layers in the model, it will intersect them at different points. Small intersection areas are then identified (the surface only separates the manufacturing layers in very small areas), which belong to a common structure (the surface) in the model. The two intersection areas are then preferentially considered contiguous sub-areas of a selected critical structure.

[0118] In both manufacturing layers, fill areas are then created around these cutting areas, which overlap in vertical projection.

[0119] The following is an embodiment that deals with the expansion of critical structures.

[0120] According to a particular aspect already mentioned above, the filling areas are created by expanding the volume of the critical structures, i.e., figuratively speaking, by "inflating" these structures.

[0121] The step of generating the number of filling areas of the method according to the invention can be modified for this embodiment as follows:

[0122] - Generating a number of fill areas, each fill area corresponding to a critical structure, which is extended in a vertical and / or horizontal orientation until it encompasses an area at the position of a manufacturing layer, which fully covers at least one vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and a manufacturing layer adjacent to it, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection.

[0123] According to a preferred embodiment of the method, the selection of the number of critical structures is made according to one or more of the listed points:

[0124] - by (directly) specifying a number of critical structures in the model, and / or

[0125] - by identifying a number of critical structures according to predefined criteria in the model, and / or

[0126] - by comparing the model with the sliced ​​model, where a critical structure in the model forms a closed surface and in the sliced ​​model has a wall thickness below a specified minimum thickness or a hole or gap is present, and / or,

[0127] - by comparing the model with an object created from the model, where a critical structure in the model forms a closed surface and in the object has a wall thickness below a specified minimum thickness or a hole or gap is present, and / or

[0128] - based on the model data and the intersections of the model data with the manufacturing layers, wherein a critical structure is a pair of intersections in adjacent manufacturing layers which fall below a specified area and / or whose union in vertical projection has a gap or hole and thus differs from the model.

[0129] Particularly in this embodiment, "active" selection of critical structures is advantageous because the selection can influence the overlap of fill areas. This is especially true when fill areas are created after slicing.

[0130] Preferably, a critical structure has a thickness less than the distance A between the manufacturing layers. In particular, a critical structure is a two-dimensional structure and preferably extends over a distance greater than A between two manufacturing layers without touching them. It preferably intersects adjacent manufacturing layers in (when viewed from above) separate surface areas.

[0131] According to an alternative preferred embodiment of the method, a number of critical structures of the model are selected, and fill regions independent of the model are generated for these structures. This preferably occurs before generating layer data of the model. According to a preferred embodiment of the method, at least one identified critical structure of the model is extended, preferably wherein the horizontal and / or vertical extension of a sub-region of a critical structure depends on its slope. Preferably, a low slope (below a predetermined limit) results in a vertical extension of the critical structure, and a high slope (above the predetermined limit) results in a horizontal extension of the critical structure.This approach has the advantage that the critical structure is modified only as necessary, while still ensuring sufficient overlap of the fill areas of adjacent manufacturing layers. With a shallow slope, vertical expansion is more significant, while with a steep slope, horizontal expansion is more prominent. Preferably, a plurality of points on the critical structure are defined, and for each point, a specific angle of extension of the critical structure is determined. If the angle is shallower relative to the horizontal than to the vertical, the critical structure is extended vertically at that point. Conversely, if the angle is shallower relative to the vertical than to the horizontal, the critical structure is extended horizontally at that point.

[0132] It is preferred that the critical structure is extended horizontally (i.e., in the direction parallel to the manufacturing layers) by an amount corresponding to a focus size of the energy beam (on the respective build plane). For this purpose, the critical structure is preferably extruded horizontally by at least half the focus size in opposite directions or by at least one focus size in one direction.

[0133] Alternatively or additionally, it is preferred that the critical structure is extended vertically by an amount that preferably corresponds to at least the distance A, in particular wherein the critical structure is extruded vertically by at least A / 2 in opposite directions or at least A in one direction. If a structure has at least the height A, it is always intersected by at least one manufacturing layer.

[0134] The extension of critical structures can occur before or during slicing. This means that the "extended" critical structures are sliced, and the fill regions are created in association with these "extended" critical structures. Alternatively, the extension of critical structures can occur after slicing. In this case, the fill regions are created in association with the critical structures as they are represented in the model (before extension). According to a preferred embodiment of the method, a number of critical structures in the model are selected, and the model is modified based on the fill regions. This means that the model is modified at the locations of the selected critical structures based on the fill regions corresponding to the critical structures. In particular, the model can be modified to extend at the locations of the critical structures.The model is preferably extended such that it encompasses the fill area corresponding to the critical structure at its position. This results in a modified model in which the projections of the sub-areas of a critical structure overlap, particularly where the sub-areas have a distance A between them in the vertical direction (z-direction). This embodiment is particularly advantageous or preferred before slicing. In particular, the model modified according to this embodiment can be sliced ​​by placing the manufacturing layers at the positions of the sub-areas of a critical structure whose projections overlap, at a distance A (i.e., at a distance equal to the vertical distance between the sub-areas of a critical structure).

[0135] Alternatively or additionally, when generating a fill area, a critical structure is deformed (modified) in such a way that it results in overlapping fill areas at a number of positions in adjacent manufacturing layers. The critical structures can be extended to cover adjacent manufacturing layers accordingly. This has the advantage that a model can be optimally modified for a slicing process.

[0136] Preferably, such a modification of the model is also carried out before the generation of layer data of the model.

[0137] Preferably, a fill area is generated by extending at least one identified critical structure of the model, preferably wherein the horizontal and / or vertical extension of a sub-area of ​​a critical structure depends on its slope. As mentioned above, the extension of a critical structure used to generate a fill area can be achieved by shifting an outer surface or points of the critical structure. Such an extension of the critical structure ensures that fill areas at the level of sub-areas of the critical structure, which have a vertical distance A from each other, or the surfaces encompassed by these fill areas, overlap (sufficiently) in plan view.An extension body is generated at the location of a critical structure, encompassing the fill areas such that sub-areas of this extension body overlap (sufficiently) at a distance A from each other in plan view. Each sub-area of ​​the extension body corresponds to a sub-area of ​​the critical structure; specifically, each sub-area of ​​the extension body lies at the same height as the corresponding sub-area of ​​the critical structure. Typically, the sub-areas of the critical structure (unlike the sub-areas of the extension body) do not overlap (sufficiently) in plan view. The extension body can then be sliced ​​at the location of the critical structure.

[0138] Alternatively, or preferably, a critical structure is extended after slicing, or an extension body is generated after slicing. The extension of the critical structure or the generation of the extension body is based on the cutting elements between the manufacturing layers (which are placed during slicing) and the (unextended) critical structure.

[0139] Particularly in connection with the extension of critical structures after slicing, it is especially preferred to select a critical structure based on the overlap (in plan view) of the cutting elements in the various manufacturing layers. During slicing, the manufacturing layers are laid down, resulting in cutting elements between the manufacturing layers and the model. Therefore, after slicing, it is possible to determine the overlap between the cutting elements and to select a critical structure where the overlap between cutting elements in at least two adjacent manufacturing layers is not present (or insufficient) in plan view. The critical structures are then extended, which in this embodiment of the invention means that the model is extended at the positions of (adjacent) manufacturing layers whose cutting elements do not overlap (or do not overlap sufficiently) in plan view.

[0140] The following is an embodiment that deals with the addition of hardening lines.

[0141] As mentioned above, the fill areas comprise hardening paths and are generated by adding these hardening paths to layer data or control commands during or after slicing. In this variant, it is preferably examined whether critical areas exist (i.e., gaps or holes are present). This examination can preferably be repeated after the fill areas have been generated. The fill areas can be generated according to any of the embodiments disclosed herein.

[0142] Particularly with critical structures that have a particularly complex shape (e.g., gyroids or surfaces with a highly curved surface), the generation of fill areas may be insufficient to produce a critical structure or a part of a critical structure without defects (holes or gaps). In other words, the complete coverage by a fill area at the position of a manufacturing layer of a vertical projection of a sub-area of ​​a selected critical structure between the positions of the manufacturing layer and an adjacent manufacturing layer may not be sufficient to eliminate all defects (holes or gaps) in the manufactured object.A renewed examination to determine whether critical areas exist in a critical structure after the generation of the fill areas makes it possible to identify the locations of a critical structure or a critical structure itself where, despite the generation of the fill areas, the critical structure cannot be built without errors.

[0143] Regardless of whether filling areas are added or not, in this variant of the procedure, consolidation paths are then and at these points of a critical structure or at the position of an (entire) critical structure.

[0144] A critical structure can be modified (e.g., "inflated" or altered by mapping it based on "blocks") by generating fill regions according to the embodiments of the method disclosed herein. Therefore, examining a critical structure after generating the fill regions to determine if critical regions exist can mean examining a structure modified by the generation of the fill regions to determine if critical regions exist. According to this variant, an additional step of adding the solidification paths, an examination step, and a step of identifying critical regions in a (modified) critical structure are performed.

[0145] - Investigate whether critical areas exist in a critical structure, preferably after the generation of fill areas, and further preferably check whether the projection of a sub-area of ​​a selected critical structure between the positions of a manufacturing layer and a manufacturing layer adjacent to it, which is fully covered by an area encompassed by a fill area, falls below a predetermined degree of coverage and / or whether the overlap in vertical projection between fill areas of related sub-areas of a selected critical structure at positions of adjacent manufacturing layers falls below a predetermined degree of overlap;and in the event that the projection of a sub-area falls below the coverage level and / or that the overlap in vertical projection between fill areas falls below a certain overlap level, - Identifying a critical area at the positions in the manufacturing layers where the specified coverage level and / or the specified overlap level is not met;

[0146] - Adding solidification paths at the positions in the manufacturing layers of the identified critical areas.

[0147] An alternative variant includes the steps of examining and identifying the critical areas. However, this alternative variant does not include the step of adding solidification paths, but instead repeats the step of generating the fill areas (as explained in the embodiments of the method disclosed herein) until a minimum predetermined degree of coverage or a minimum predetermined degree of overlap is achieved.

[0148] A coverage ratio can be specified in the following forms:

[0149] - A minimum surface area, where this minimum surface area has an absolute value. For example, the projection of a sub-region of a selected critical structure is at least 6,400 pm. 2 preferably at least 57,600 pm 2 , especially preferred at least 160,000 pm 2The fact that the projection of a sub-area of ​​a critical structure between the positions of a manufacturing layer, which is fully covered by an area encompassed by a fill region, falls below the specified degree of coverage, meant in this case that the surface of this projection was, for example, smaller than 6,400 pm. 2 preferably smaller than 57,600 pm 2 , especially those smaller than 160,000 pm 2 is.

[0150] - A length, where this minimum length is an absolute value. For example, the extent of a projection of a partial region of a selected critical structure in at least one direction of extension of the projection itself is at least 80 pm, preferably at least 240 pm, and particularly preferably at least 400 pm. The fact that the projection of a partial region of a critical structure between the positions of a manufacturing layer, which is fully covered by an area encompassed by a fill region, falls below the specified degree of coverage means, in this case, that the extent of this projection in every direction of extension is, for example, less than 80 pm, preferably less than 240 pm, and particularly preferably less than 400 pm.

[0151] - A percentage of the surface area of ​​the projection of the entire selected critical structure. For example, the surface area of ​​the projection of a sub-area of ​​a selected critical structure is at least 5%, preferably at least 10%, and particularly preferably at least 25% of the surface area of ​​the projection of the entire selected critical structure. In this case, if the projection of a sub-area of ​​a critical structure between the positions of a manufacturing layer, which is fully covered by an area encompassed by a fill region, falls below the specified coverage level, then the surface area of ​​this projection is, for example, less than 5%, preferably less than 10%, and particularly preferably less than 25% of the surface area of ​​the projection of the entire selected critical structure.

[0152] - A minimum number of hardening paths. For example, the projection of a sub-area of ​​a critical structure includes at least one hardening path, preferably at least three hardening paths, and particularly preferably at least five. If the projection of a sub-area of ​​a critical structure between the positions of a manufacturing layer, which is fully covered by an area encompassed by a fill region, falls below the specified degree of coverage, this means that, for example, this projection contains no hardening path, preferably fewer than three hardening paths, and particularly preferably fewer than five.

[0153] The degree of overlap can be specified in the following ways:

[0154] - A minimum overlap area with a predefined minimum overlap (or predefined overlap degree). A preferred overlap area is at least 6,400 pm. 2 preferably at least 57,600 pm 2, especially preferred at least 160,000 pm 2 The fact that the overlap in vertical projection between fill areas falls below a certain overlap degree means, in this case, that the surface area of ​​the overlap is, for example, smaller than 6,400 pm. 2 preferably smaller than 57,600 pm 2 , especially those smaller than 160,000 pm 2 , is.

[0155] - An extent length, where this extent length is an absolute value. A predetermined extent length (or the predetermined overlap ratio) of the overlap in at least one extent direction, for example, is at least 80 pm, preferably at least 240 pm, and particularly preferably at least 400 pm. In this case, the fact that the overlap in vertical projection between filling areas falls below a specified overlap ratio means that the extent length of the overlap in each extent direction is less than 80 pm, preferably less than 240 pm, and particularly preferably less than 400 pm.

[0156] - A percentage of the surface area of ​​the projection of an entire fill region under the two fill regions of contiguous subregions of a selected critical structure at positions of adjacent manufacturing layers, or a percentage of the sum of the surface areas of the projections of the entire two fill regions. A predetermined proportion of the surface area (or the predetermined overlap ratio) of the projection of one of the fill regions is, for example, at least 5%, preferably at least 15%, particularly preferably at least 25% of the surface area of ​​the projection of an entire fill region or of the sum of the surface areas of the two entire fill regions.In this case, the fact that the overlap in vertical projection between fill areas falls below a certain degree of overlap means that the surface area of ​​the overlap of the two fill areas in vertical projection is less than 5%, preferably less than 10%, and particularly preferably less than 25% of the surface area of ​​the projection of an entire fill area or the sum of the surfaces of the projections of the two entire fill areas.

[0157] Consolidation paths can take the form of straight, parallel hatch lines, or of circular or spiral paths. It should be noted that the term "consolidation paths" here does not refer to consolidated structures, but rather to paths traversed for the consolidation process during the construction of an object. Consolidation paths can therefore be tracks or trajectories (hatch lines) comparable to consolidation paths. They differ from consolidation paths in that consolidation paths are added outside of, or not in conjunction with, the fill areas, but rather in connection with critical areas that may arise, for example, between fill areas. In contrast, as explained above, consolidation paths are essentially placed within the fill areas; that is, the fill areas are filled with consolidation paths.

[0158] Regarding the filling areas, the following process step is preferred:

[0159] - Generating a number of fill areas, wherein for the fill areas solidification paths are added to the manufacturing layers, filling an area that fully covers at least one vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and a manufacturing layer adjacent to it, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection.

[0160] According to a preferred embodiment of the method, the number of critical structures is selected according to one or more of the listed points:

[0161] - by (directly) specifying a number of critical structures in the model,

[0162] - by identifying a number of critical structures in the model according to predefined criteria, and / or - by comparing the model with the sliced ​​model, where a critical structure in the model forms a closed surface and in the sliced ​​model has a wall thickness below a predefined minimum thickness or has a hole or gap,

[0163] - by comparing the model with an object created from the model, where a critical structure in the model forms a closed surface and in the object has a wall thickness below a specified minimum thickness or a hole or gap is present, and / or

[0164] - based on the model data and the intersections of the model data with the manufacturing layers, where a critical structure is an area where a few of the intersection surfaces of a structure of the model in adjacent manufacturing layers have a gap or hole when viewed from above and thus differ from the model, or where an already manufactured object has a gap or hole and thus differs from the model.

[0165] Preferably, a critical structure has a thickness less than the distance A between the manufacturing layers. In particular, a critical structure is a two-dimensional structure and preferably extends over a distance greater than A between two manufacturing layers without touching them. It preferably intersects adjacent manufacturing layers in (when viewed from above) separate surface areas.

[0166] According to a preferred embodiment of the method, a number of critical structures of the model are selected, and manufacturing layers are modified based on the fill areas (during or after slicing). Preferably, this is done before generating layer data of the model.

[0167] When generating a fill area, layer areas are preferably created at the positions of the manufacturing layers in the model, corresponding to the respective fill areas. In a simple case, this means areas are created or inserted where the slicer can later recognize them. This has the advantage that modifications are only made where a slicer can detect them.

[0168] Alternatively or additionally preferably, a corresponding fill area is generated by moving a copy of a number of points of the model in each critical structure to at least one of the adjacent manufacturing layers, preferably the nearest one.

[0169] Alternatively or additionally preferably, a corresponding filling area is generated by creating layer areas on the manufacturing layers which correspond to the relevant filling areas, preferably by vertical projection of the sub-areas onto the manufacturing layers.

[0170] In one embodiment of the method, the steps of adding solidification paths, examining, and identifying critical areas are provided, while preferably omitting the step of generating filler areas. This embodiment of the method is particularly advantageous for components where only small manufacturing defects (holes or gaps) are expected, or for components with a periodic structure where the same type of defect (holes or gaps) occurs repeatedly or periodically. In these cases, in particular, manufacturing defects can be corrected even without generating filler areas. According to this embodiment of the method, the following steps are performed:

[0171] - Providing model data, including geometric data of the model;

[0172] - Defining the positions of the production layers, where two adjacent production layers are parallel to each other at a distance A;

[0173] - Selecting a number of critical structures of the model based on the model data and / or a pre-existing object;

[0174] - Investigate whether critical areas exist in a critical structure, preferably by checking whether a projection of a first sub-area of ​​a selected critical structure, which lies between the positions of a first manufacturing layer and a second manufacturing layer adjacent to the first, which fully covers a projection of a second sub-area, which lies between the positions of the second manufacturing layer and a manufacturing layer adjacent to the second, falls below a certain degree of coverage;

[0175] - Identifying a critical area at the positions in the production layers where the specified coverage level is not met;

[0176] - Adding solidification paths at the positions in the manufacturing layers of the identified critical areas.

[0177] In this embodiment, as in known prior art methods, hardening paths are placed at the interfaces between the manufacturing layers and the model. The placement of hardening paths can occur before or after the process steps and, in this embodiment, is not affected by the execution of the process steps. After the hardening paths have been placed and the process steps are executed, the hardening paths (e.g., in the form of a scan pattern) and the hardening paths themselves become part of the layer data used to generate the control data for executing an additive manufacturing process. The selection of critical areas is carried out according to the procedures described above.

[0178] In a preferred embodiment, the investigation to determine whether critical areas exist is based on an overlap between critical cutting elements (as defined above). In this embodiment, the critical structure is examined to determine whether there are intersection points, cutting lines, or cutting surfaces in adjacent manufacturing layers that do not overlap or overlap insufficiently. Cutting surfaces (especially thin cutting surfaces) can be designated as "critical cutting elements" due to a missing or insufficient overlap with another cutting surface of an adjacent manufacturing layer. For intersection points or cutting lines, the overlap with other cutting elements in adjacent manufacturing layers will never be sufficient; therefore, intersection points and cutting lines can be considered critical cutting elements.Prior knowledge of the structure's shape, or at least the understanding that two surfaces belong together to a coherent structure, could be helpful here. If this investigation reveals cut features that have no or insufficient overlap with other critical cut features in adjacent fabricated layers, these cut features are identified as critical areas. Solidification paths are then added at the locations of these identified critical areas.

[0179] In another preferred embodiment, critical structures are selected based on the overlap between critical cut features, so that the step of examining critical areas is performed before or simultaneously with the selection of the critical structures. In this preferred embodiment, it is not examined whether critical areas or critical cut features (the critical areas are identified based on critical cut features) are present in a critical structure, but rather critical structures are selected as such if they contain critical cut features. Hardening paths are then added where a critical cut feature is present or has been identified. According to this preferred embodiment, the steps of selecting a critical structure, identifying critical areas, and adding hardening paths are performed as follows:

[0180] - Selecting a critical structure based on the model data and the intersections of the model data with the manufacturing layers, where a critical structure is an area where a few of the intersection surfaces of a structure of the model in adjacent manufacturing layers, when viewed from above, have a gap or hole and thus differ from the model; - Identifying at least one critical area at the locations of the manufacturing layers of the critical structure.

[0181] - Adding consolidation paths at the locations of the identified areas.

[0182] Alternatively, as mentioned at the beginning, it is also possible to define a critical structure based on errors (gap or holes) in an already manufactured object or in process control data for the manufacture of this object, especially at the points where the manufactured or to-be-manufactured object differs from the model due to these errors.

[0183] It is possible to identify multiple critical regions within a critical structure. It is also possible for the entire critical structure to be identified as a critical region. Specifically, a critical region can be identified at the positions of a pair of manufacturing layers within the critical structure whose intersections (cutting surfaces) do not overlap or do not overlap sufficiently. Since a critical structure can be sliced ​​by multiple manufacturing layers, there can be several pairs of manufacturing layers within a critical structure at the positions of which a critical region can be identified. A hardening path can be added at the position (height) of one of the two manufacturing layers or at the positions (heights) of both manufacturing layers of the identified critical region.The steps of selecting a critical structure and examining and identifying critical areas are therefore carried out alternatively as follows:

[0184] - Selecting a number of critical structures of the model based on the model data and the intersections of the model data with the manufacturing layers, where a critical structure is an area where a few of the intersection surfaces of a structure of the model in adjacent manufacturing layers have a gap or hole when viewed from above and thus differ from the model,

[0185] - Investigate whether critical areas exist in a critical structure, preferably by checking whether a projection of a first sub-area of ​​a selected critical structure, which lies between the positions of a first manufacturing layer and a second manufacturing layer adjacent to the first, fully covers a projection of a second sub-area, which lies between the positions of the second manufacturing layer and a third manufacturing layer adjacent to the second, falls below a predetermined degree of coverage.Alternatively, it is still possible to select a critical structure as such if a projection of a sub-area of ​​the selected critical structure, which lies between the positions of a first manufacturing layer and a second manufacturing layer adjacent to the first, fully covers a projection of a second sub-area of ​​the selected critical structure, which lies between the positions of the second manufacturing layer and a manufacturing layer adjacent to the second, but falls below a predetermined degree of coverage.

[0186] A coverage ratio can be specified in the following forms:

[0187] - A minimum surface area with a predefined minimum area value. For example, the projection of a sub-area of ​​a selected critical structure is at least 6,400 pm. 2 preferably at least 57,600 pm 2 , especially preferably at least 160,000pm 2The fact that the projection of a first sub-area of ​​a critical structure between the positions of a first manufacturing layer and a second manufacturing layer adjacent to the first, which fully covers a projection of a second sub-area between the second and a third manufacturing layer adjacent to the second, falls below the specified degree of coverage, meant in this case that the surface of this projection was, for example, smaller than 6,400 pm. 2 preferably smaller than 57,600 pm 2 , especially those smaller than 160,000 pm 2 is.

[0188] - A length, where this minimum length is an absolute value. For example, the extent of a projection of a sub-area of ​​a selected critical structure in at least one direction of extension of the projection itself is at least 80 pm, preferably at least 240 pm, and particularly preferably at least 400 pm. The fact that the projection of a first sub-area of ​​a critical structure between the positions of a first manufacturing layer and a second manufacturing layer adjacent to the first, which fully covers a projection of a second sub-area between the second and a third manufacturing layer adjacent to the second, falls below the specified degree of coverage, means in this case that the extent of this projection in each direction of extension is, for example, less than 80 pm, preferably less than 240 pm, and particularly preferably less than 400 pm.

[0189] - A percentage of the surface area of ​​the projection of the entire selected critical structure. For example, the surface area of ​​the projection of a sub-region of a selected critical structure is at least 5%, preferably at least 10%, and particularly preferably at least 25% of the surface area of ​​the projection of the entire selected critical structure. If the projection of a first sub-region of a critical structure between the positions of a first manufacturing layer and a second manufacturing layer adjacent to the first, which fully covers a projection of a second sub-region between the second and a third manufacturing layer adjacent to the second, falls below the specified coverage level, then in this case, the surface area of ​​this projection is, for example, less than 5%, preferably less than 10%, and particularly preferably less than 25% of the surface area of ​​the projection of the entire selected critical structure.

[0190] - A minimum number of hardening paths. For example, the projection of a sub-region of a critical structure includes at least one hardening path, preferably at least three hardening paths, and particularly preferably at least five. If the projection of a first sub-region of a critical structure between the positions of a first manufacturing layer and a second manufacturing layer adjacent to the first, which fully covers a projection of a second sub-region between the second and a third manufacturing layer adjacent to the second, falls below the specified degree of coverage, this means that, for example, this projection contains no hardening path, preferably fewer than three hardening paths, and particularly preferably fewer than five.

[0191] In a further preferred embodiment, the step of examining critical areas includes an analysis of the applied hardening paths. This analysis can be performed regardless of how the hardening paths are generated, i.e., whether they are placed within fill areas or in the model. As mentioned earlier, after slicing, hardening paths can be applied at the overlaps (“cutting features”) between a manufacturing layer and the model. A gap or hole in the manufactured part can occur where the overlap between hardening paths in a manufacturing layer or between hardening paths in (two) adjacent manufacturing layers is either absent or insufficient. The absence of overlap between hardening paths in a layer or in (two) adjacent layers will be determined based on the following criteria:

[0192] - No vector in a first manufacturing layer completely covers a second adjacent manufacturing layer in the overhead view;

[0193] - There is only one solidification path in a manufacturing layer.

[0194] - Two consolidation paths in a layer run along a length that is less than a predetermined length, within a distance interval of each other;

[0195] - No intersection point exists for non-parallel hardening paths. The following is an embodiment that deals with the displacement of critical structures.

[0196] As mentioned earlier, the fill areas are created by moving critical structures onto manufacturing layers. This can be done directly in the model (before or during slicing) or separate fill areas can be added at the position of the critical structures, corresponding to the distorted critical areas.

[0197] The step of generating the number of filling areas of the method according to the invention can be modified for this embodiment as follows:

[0198] - Generating a number of fill areas, each fill area corresponding to a critical structure, which is shifted and / or distorted in a vertical and / or horizontal orientation until it encompasses an area at the position of a manufacturing layer, which fully covers at least one vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and an adjacent manufacturing layer, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection.

[0199] According to a preferred embodiment of the method, the number of critical structures is selected according to one or more of the listed points:

[0200] - by (directly) specifying a number of critical structures in the model,

[0201] - by identifying a number of critical structures according to predefined criteria in the model, and / or

[0202] - by comparing the model with the sliced ​​model, where a critical structure in the model forms a closed surface and in the sliced ​​model has a wall thickness below a specified minimum thickness or has a hole or gap,

[0203] - by comparing the model with an object created from the model, where a critical structure in the model forms a closed surface and in the object has a wall thickness below a specified minimum thickness or there is a hole or gap.

[0204] Preferably, a critical structure is one with a thickness less than the distance A between the manufacturing layers. In particular, a critical structure is a two-dimensional structure and preferably extends over a distance greater than A between two manufacturing layers without touching them. It preferably intersects adjacent manufacturing layers in (in top view) separate surface areas. Preferably, a fill area is generated from a sub-area of ​​a critical structure, which

[0205] - more than a predetermined distance runs within the space between the positions of two adjacent production layers and / or

[0206] - represents an intersection with another structure with a thickness less than A within the space between the positions of two adjacent manufacturing layers.

[0207] According to a preferred embodiment of the method, a number of critical structures of the model are selected, and the model is modified based on the fill regions (before or during slicing). Preferably, this is done before generating layer data of the model.

[0208] According to an alternative preferred embodiment of the method, a number of critical structures of the model are selected, and fill regions independent of the model are generated for these structures. Preferably, this is done before generating layer data of the model.

[0209] Alternatively or additionally, when generating a fill area, a critical structure is deformed and / or shifted in such a way that it results in overlapping fill areas at a number of positions on adjacent manufacturing layers. The critical structures can be extended so that they cover adjacent manufacturing layers accordingly and / or are shifted onto manufacturing layers. This has the advantage that a model can be optimally modified for a slicing process.

[0210] The following is an embodiment that deals with “pixelating” areas of the model.

[0211] As mentioned earlier, the fill areas are created by representing critical structures using blocks. This can be done directly in the model (before or during slicing) or blocks can be added at the location of the critical structures.

[0212] The step of generating the number of filling areas of the method according to the invention can be modified for this embodiment as follows:

[0213] - Generating a number of fill areas, each fill area corresponding to a replica of the critical structure by means of blocks that have at least a vertical extent of A (distance between two manufacturing layers) and these blocks represent an area at the position of a manufacturing layer which fully covers at least a vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and a manufacturing layer adjacent to it, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection.

[0214] In practice, for example, a block with a focal width in one direction (preferably in a single direction in the XY plane) and a thickness A can be generated for a cutting line. The two manufacturing layers then cut the block at the top and / or bottom surface. To generate a fill area, a block is preferably duplicated (or a block is added) so that the blocks overlap in the manufacturing layers. It is also preferred that a block is extended by A / 2 in both directions, i.e., the blocks meet midway between two manufacturing layers, and one manufacturing layer intersects the block.

[0215] According to a preferred embodiment of the method, the number of critical structures is selected according to one or more of the listed points:

[0216] - by (directly) specifying a number of critical structures in the model,

[0217] - by identifying a number of critical structures according to predefined criteria in the model, and / or

[0218] - by comparing the model with the sliced ​​model, wherein a critical structure in the model forms a closed surface and in the sliced ​​model has a wall thickness below a specified minimum thickness or there is a hole or gap, - by comparing the model with an object created from the model, wherein a critical structure in the model forms a closed surface and in the object has a wall thickness below a specified minimum thickness or there is a hole or gap.

[0219] Preferably, a critical structure has a thickness less than the distance A between the manufacturing layers. In particular, a critical structure is a two-dimensional structure and preferably extends over a distance greater than A between two manufacturing layers without touching them. It preferably intersects adjacent manufacturing layers in (when viewed from above) separate surface areas.

[0220] According to a preferred embodiment of the method, a number of critical structures of the model are selected, and the model is modified based on the fill regions (before or during slicing). Preferably, this is done before generating layer data of the model.

[0221] According to an alternative preferred embodiment of the method, a number of critical structures of the model are selected, and fill regions independent of the model are generated for these structures. Preferably, this is done before generating layer data of the model.

[0222] When generating a fill area, layer areas are preferably created at the positions of the manufacturing layers in the model, corresponding to the respective fill areas. In a simple case, this means areas are created or inserted where the slicer can later recognize them. This has the advantage that modifications are only made where a slicer can detect them.

[0223] Alternatively or additionally, preferably, when generating a fill area, the critical structure is recreated from voxels (or blocks) with predetermined dimensions, preferably wherein each voxel (or block) intersects the position of a manufacturing layer and / or each voxel (or block) has a height of at least A. This has the advantage that a critical area can be compensated for with very little computational effort.

[0224] Alternatively or additionally preferably, a corresponding fill area is generated by forming blocks with a minimum height of A at the position of sub-regions of a critical structure. In particular, a preferred fill area can be generated by adding additional blocks to a critical structure that has been replicated by voxels (blocks), at least at the position of a manufacturing layer, such that the voxels (both the voxels that replicate the critical structure and the voxels that have been added to the critical structure) at the position of this manufacturing layer form an area which completely covers at least a vertical projection of a sub-region of a selected critical structure between the positions of the manufacturing layer and a manufacturing layer adjacent to it.The fill area preferably corresponds to the sum of the voxels used to recreate the critical structure in a manufacturing layer and the voxels added to the critical structure at the manufacturing layer's position. Thus, the fill area (the sum of the voxels used to recreate the critical structure in a manufacturing layer and the voxels added to the critical structure at the manufacturing layer's position) encompasses an area that fully covers at least one vertical projection of a sub-region of a selected (and voxel-recreated) critical structure between the positions of this manufacturing layer, and that fill areas of contiguous sub-regions of a selected critical structure overlap in vertical projection at positions of vertically adjacent manufacturing layers.

[0225] The reconstruction of critical structures from voxels and the generation of fill areas from added voxels can be performed before slicing. In this case, the voxels are then sliced ​​together with the model.

[0226] The reconstruction of critical structures from voxels and the generation of fill areas can take place after slicing. In this case, the reconstruction of critical structures and the generation of fill areas are based on cutting elements (as defined earlier). Specifically, the voxels are formed starting from a cutting element (cutting surface, cutting line, or intersection point).

[0227] The following is an embodiment that deals with “copying” areas to form a fill area.

[0228] As mentioned earlier, the fill areas are created by copying surface areas onto manufacturing layers. These surface areas correspond to vertical projections of sub-areas of critical structures. This can be done directly in the model (before or during slicing), or points or surfaces can be added to the layer data as cutting surfaces or blocks, preferably with a maximum height A and a maximum width of the focus point.

[0229] The step of generating the number of filling areas of the method according to the invention can be modified for this embodiment as follows:

[0230] - Generating a number of fill areas, wherein cut surfaces are added to the manufacturing layers for the fill areas, the area of ​​which fully covers at least a vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and a manufacturing layer adjacent to it, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection,

[0231] According to a preferred embodiment of the method, the number of critical structures is selected according to one or more of the listed points:

[0232] - by (directly) specifying a number of critical structures in the model, - by identifying a number of critical structures according to predefined criteria in the model, and / or

[0233] - by comparing the model with the sliced ​​model, where a critical structure in the model forms a closed surface and in the sliced ​​model has a wall thickness below a specified minimum thickness or has a hole or gap,

[0234] - by comparing the model with an object created from the model, where a critical structure in the model forms a closed surface and in the object has a wall thickness below a specified minimum thickness or there is a hole or gap.

[0235] Preferably, a critical structure has a thickness less than the distance A between the manufacturing layers. In particular, a critical structure is a two-dimensional structure and preferably extends over a distance greater than A between two manufacturing layers without touching them. It preferably intersects adjacent manufacturing layers in (when viewed from above) separate surface areas.

[0236] According to a preferred embodiment of the method, a number of critical structures of the model are selected, and manufacturing layers are modified based on the fill areas (during or after slicing). Preferably, this is done before generating layer data of the model.

[0237] When generating a fill area, layer areas are preferably created at the positions of the manufacturing layers in the model, corresponding to the respective fill areas. In a simple case, this means areas are created or inserted where the slicer can later recognize them. This has the advantage that modifications are only made where a slicer can detect them.

[0238] Alternatively or additionally preferably, a corresponding fill area is generated by moving a copy of a number of points of the model in each critical structure to at least one of the adjacent manufacturing layers, preferably the nearest one.

[0239] Alternatively or additionally, a corresponding fill area is generated by creating layer areas on the manufacturing layers that correspond to the fill areas in question, preferably by vertical projection of the sub-areas onto the manufacturing layers. A preferred embodiment is described in more detail below, in which copies of structures are added horizontally shifted to create fill areas.

[0240] As mentioned above, the fill areas are created by copying a critical structure, shifted horizontally and / or vertically by a defined distance, next to the original critical structure. This is preferably done directly in the model, or these additional structures are also taken into account during slicing. The following considerations can also be applied to fill areas within the framework of the previously described "copying" embodiment. In this case, the corresponding fill area is copied instead of the critical structure and shifted horizontally or vertically (to the adjacent manufacturing layer).

[0241] The step of generating the number of filling areas of the method according to the invention can be modified for this embodiment as follows:

[0242] - Generating a number of fill areas, wherein each fill area comprises an area at the position of a manufacturing layer, which fully covers at least one vertical projection of a sub-area of ​​a selected critical structure between the positions of this manufacturing layer and a manufacturing layer adjacent to it, and fill areas of contiguous sub-areas of a selected critical structure overlap at positions of adjacent manufacturing layers in vertical projection, wherein fill areas are generated by copying at least one sub-area of ​​a critical structure (or the entire critical structure) and shifting this copy horizontally and / or vertically by a specified distance to the original critical structure.In this sense, the preceding “and / or” means not only that the copy can be moved horizontally and vertically at the same time, but also that one copy can be moved horizontally and another copy can be moved vertically.

[0243] According to a preferred embodiment of the method, the number of critical structures is selected according to one or more of the listed points:

[0244] - by (directly) specifying a number of critical structures in the model,

[0245] - by identifying a number of critical structures according to predefined criteria in the model, and / or

[0246] - by comparing the model with the sliced ​​model, wherein a critical structure in the model forms a closed surface and in the sliced ​​model has a wall thickness below a specified minimum thickness or there is a hole or gap, - by comparing the model with an object created from the model, wherein a critical structure in the model forms a closed surface and in the object has a wall thickness below a specified minimum thickness or there is a hole or gap.

[0247] This embodiment is particularly advantageous for structures in the form of triangular, square, or hexagonal prisms, whereby the walls of these prisms are preferably considered separately as critical structures. Vertical walls can be deliberately excluded from the critical structures, which allows them to be manufactured with optimal precision.

[0248] Preferably, a critical structure has a thickness less than the distance A between the manufacturing layers. In particular, a critical structure is a two-dimensional structure and preferably extends over a distance greater than A between two manufacturing layers without touching them. It preferably intersects adjacent manufacturing layers in (when viewed from above) separate surface areas.

[0249] Preferably, the copying and moving process is performed multiple times with different predefined intervals and / or with different orientations.

[0250] A preferred distance for a displacement is half or the whole distance A between two manufacturing layers (particularly preferred for a vertical displacement) or the radius or diameter of the focus size of the energy beam (particularly preferred for a horizontal displacement).

[0251] Preferably, a copy of a sub-area of ​​a critical structure is shifted horizontally and / or vertically depending on its slope. Preferably, a vertical shift of the copy occurs at a low slope (below a predefined limit), and a horizontal shift of the critical structure occurs at a high slope (above the predefined limit). This approach has the advantage that the critical structure is modified only as much as necessary, while still ensuring sufficient overlap of the fill areas of adjacent manufacturing layers. A vertical shift has a greater impact at a low slope, while a horizontal shift is more significant at a high slope. If the critical structure is curved and has varying slopes, it can be divided, and copies of the sub-areas can be shifted according to the slope of each sub-area.However, it is also possible to copy the entire critical structure and move it both vertically and horizontally. According to a preferred embodiment of the method, a number of critical structures of the model are selected, and the model is modified based on the filled areas (before or during slicing). Preferably, this is done before generating layer data of the model.

[0252] According to an alternative preferred embodiment of the method, a number of critical structures of the model are selected, and fill regions independent of the model are generated for these structures. Preferably, this is done before generating layer data of the model.

[0253] A preferred device further comprises a layer data generation unit designed to create layer data of the model from the cross-sectional surfaces of the model with planes at the positions of the manufacturing layers. The layer data generation unit is preferably designed to create layer data from cross-sectional surfaces of a number of fill areas with planes at the positions of the manufacturing layers, and preferably also to create a fill pattern of lines.

[0254] A preferred device additionally comprises a control data generation unit designed for modifying or creating control commands from shift data. This generation is known in the prior art.

[0255] The use of AI-based methods (AI: "Artificial Intelligence") is preferred for the method according to the invention. Artificial intelligence is based on the principle of machine learning and is generally implemented with a learning algorithm that has been trained accordingly. The English term "machine learning" is frequently used for machine learning, and this also includes the principle of "deep learning".

[0256] Preferably, components of the invention are provided as a "cloud service." Such a cloud service serves to process data, particularly using artificial intelligence, but can also be a service based on conventional algorithms or a service where human evaluation takes place in the background. Generally, a cloud service (hereinafter also referred to simply as "cloud") is an IT infrastructure in which, for example, storage space or computing power and / or application software is provided via a network. Communication between the user and the cloud takes place via data interfaces and / or data transmission protocols. In the present case, it is particularly preferred that the cloud service provides both computing power and application software.

[0257] In a preferred method, data obtained within the scope of the invention is provided to the cloud service via the network. This cloud service comprises a computing system that typically does not include the user's local computer. The method can be implemented using a command structure within a network. The data processed in the cloud is subsequently sent back to the user's local computer via the network.

[0258] The invention is explained in more detail below with reference to the accompanying figures and exemplary embodiments. The same components are designated with identical reference numerals in the various figures. The figures are generally not to scale. They show:

[0259] Figure 1 shows a schematic, partially sectional view of an embodiment of a manufacturing device for additive manufacturing with a device according to the invention.

[0260] Figure 2 shows a method for improving the quality of an additively manufactured object layer by layer.

[0261] Figure 3 shows a preferred variant of the method,

[0262] Figure 4 shows a preferred further variant of the method,

[0263] Figure 5 shows a preferred further variant of the method,

[0264] Figure 6 shows a preferred further variant of the method,

[0265] Figure 7 shows a preferred further variant of the method,

[0266] Figure 8 shows a preferred further variant of the method,

[0267] Figure 9 shows a preferred further variant of the method.

[0268] Figure 10 shows a preferred further variant of the method. The following exemplary embodiments are described with reference to a manufacturing device 1 for the additive manufacturing of components in the form of a selective laser sintering or laser melting device, whereby it is explicitly pointed out again that the invention is not limited to selective laser sintering or laser melting devices.

[0269] Such a manufacturing device 1 is shown schematically in Figure 1. It has a process chamber 3 or process space 3 with a chamber wall 4, in which the manufacturing process essentially takes place. Inside the process chamber 3 is an upwardly open container 5 with a container wall 6. The upper opening of the container 5 forms the current working level 7. The area of ​​this working level 7 located within the opening of the container 5 can be used to build the object 2 and is therefore referred to as the build area 8.

[0270] Container 5 has a base plate 11 that is movable in a vertical direction and is mounted on a support 10. This base plate 11 closes off the container 5 at the bottom, thus forming its base. The base plate 11 can be formed integrally with the support 10, or it can be a separate plate that is attached to or simply supported by the support 10. Depending on the specific material used, such as the powder, and the manufacturing 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 also be built directly on the base plate 11 itself, which then serves as the build platform.

[0271] The basic assembly of object 2 is carried out by first applying a layer of the build material 13 to the build platform 12, then selectively solidifying the build material 13 at the points that are to form parts of the object 2 to be manufactured using a laser beam 22 as an energy beam, then lowering the base plate 11, and thus the build platform 12, with the aid of the support 10, and applying and selectively solidifying a new layer of the build material 13, and so on. In Figure 1, object 2, assembled in the container on the build platform 12 below the working plane 7, is shown in an intermediate state. It already has several solidified layers, surrounded by unsolidified build material 13.Various materials can be used as build-up material 13, preferably powders, in particular metal powders, plastic powders, ceramic powders, sand, filled or mixed powders, or pasty materials, and optionally a mixture of several materials. Fresh build-up material 15 is located in a storage container 14 of the manufacturing device 1. With the aid of a coater 16 movable in a horizontal direction, the build-up material can be applied in the work plane 7 or within the build area 8 in the form of a thin layer.

[0272] Optionally, an additional radiant heater 17 is located in process chamber 3. This heater can be used to heat the applied build-up material 13, so that the irradiation device used for selective solidification does not have to supply too much energy. This means, for example, that a certain amount of base energy can be introduced into the build-up material 13 using the radiant heater 17, which is naturally still below the energy required for the build-up material 13 to fuse or sinter. An infrared radiator or a VCSEL radiator, for example, can be used as the radiant heater 17.

[0273] For selective hardening, the manufacturing device 1 includes an irradiation device 20, or more specifically, an exposure device 20 with a laser 21. This laser 21 generates a laser beam 22, which is deflected by a deflecting device 23 to trace the exposure paths or tracks (hatch lines) in the layer to be selectively hardened, as defined by the exposure strategy, and to selectively introduce the energy. Furthermore, this laser beam 22 is focused onto the working plane 7 in a suitable manner by a focusing device 24. The irradiation device 20 is preferably located outside the process chamber 3, and the laser beam 22 is directed into the process chamber 3 via a coupling window 25 located in the chamber wall 4 on the upper side of the process chamber 3.

[0274] The irradiation device 20 can, for example, comprise not just one, but several lasers. Preferably, these can be gas or solid-state lasers or any other type of laser, such as laser diodes, in particular VCSELs (Vertical Cavity Surface Emitting Lasers) or VECSELs (Vertical External Cavity Surface Emitting Lasers), or an array of such lasers. Most preferably, one or more unpolarized single-mode lasers, e.g., a 3 kW fiber laser with a wavelength of 1070 nm, can be used within the scope of the invention.

[0275] A control device 30, comprising a control unit 29, serves to control the units of the manufacturing device 1. This control unit 29 controls the components of the irradiation device 20, namely the laser 21, the deflection device 23, and the focusing device 24. The control unit 29 also controls the radiant heater 17 using suitable heating control data HS, the recoater 16 using coating control data ST, and the movement of the carrier 10 using carrier control data TS, thus controlling the layer thickness.

[0276] Control device 30 here comprises a device 34 according to the invention for improving the quality of an additively manufactured object 2 layer by layer. The device 34 comprises a data interface 33, a setting unit 34, a selection unit 35, a filling area unit 36, a modification unit 37, a layer data generation unit 38 and a control data generation unit 39.

[0277] The data interface 33 is used to receive model data MD, which includes comprehensive geometric data of the model M.

[0278] The fixing unit 34 is used to fix positions of the production layers F, F+, F-, wherein two adjacent production layers F, F-, F+ are parallel to each other at a distance A.

[0279] Selection unit 35 is used to select critical structures S of model M based on the model data MD and / or an already manufactured object 2 and / or process control data (PS).

[0280] The filling area unit 36 ​​serves to generate a number of filling areas B, wherein each filling area B comprises an area at the position of a manufacturing layer F, which fully covers at least a vertical projection of a sub-area of ​​a selected critical structure S between the positions of this manufacturing layer F and a manufacturing layer F-, F+ adjacent to it, and filling areas B of contiguous sub-areas of a selected critical structure S overlap in vertical projection at positions of adjacent manufacturing layers F, F-, F+.

[0281] The modification unit 37 is used to utilize the fill areas B to modify the model M and / or to modify layer data SD of the model M and / or control data to manufacture an object 2 based on the model M.

[0282] The layer data generation unit 38 is designed to create layer data SD of model M from the intersection surfaces of model M with planes at the positions of the manufacturing layers F, F+, F-. Preferably, layer data SD is created from intersection surfaces of a number of fill areas B with planes at the positions of the manufacturing layers F, F+, F-, e.g., a fill pattern of lines.

[0283] The control data generation unit 39 is designed to modify or create PS control commands from SD shift data.

[0284] It should also be noted again at this point that the present invention is not limited to such a manufacturing device 1. It can be applied to other methods for the generative or additive manufacturing of a three-dimensional object by layer-by-layer application and selective solidification of a build-up material, wherein an energy beam is emitted onto the build-up material to be solidified. Accordingly, the irradiation device can also be anything other than a laser, as described here; any device could be used with which energy can be selectively introduced onto or into the build-up material as wave or particle radiation. For example, instead of a laser, another light source, an electron beam, etc., could be used.

[0285] Figure 2 shows a method for improving the quality of an additively manufactured object 2 layer by layer.

[0286] In step I, model data MD is provided, comprising geometric data of the model M.

[0287] In step II, the positions of the production layers F, F-, F+ are determined, whereby two adjacent production layers F, F- F+ are parallel to each other at a distance A.

[0288] In step III, a number of critical structures S of the model M are selected based on the model data MD and / or an already manufactured object 2 and / or process control data PS.

[0289] In step IV, a number of fill areas B are generated, each fill area B comprising an area at the position of a manufacturing layer F. This area fully covers at least one vertical projection of a sub-area of ​​a selected critical structure S between the positions of this manufacturing layer F and an adjacent manufacturing layer F-, F+. Fill areas B of contiguous sub-areas of a selected critical structure S overlap in vertical projection at the positions of adjacent manufacturing layers F, F-, F+. In step V, the fill areas B are used to modify the model M and / or to modify layer data SD of the model M and / or control data for the manufacturing of an object 2 based on the model M.

[0290] Figure 3 outlines a preferred variant of the method in which infill areas B are generated based on cross-sectional surfaces with manufacturing layers F, F+. Following a slicing process, cross-sectional areas in manufacturing layers F, F+ are identified that have an area below a predefined threshold, or where a hole or gap would be present in an object 2 but not in the model M. These cross-sectional areas are then defined as critical regions. In the model M, a critical structure S exists at this location, as shown on the left of the figure. In this example, an inclined surface (viewed from the side) runs transversely through the manufacturing layers F, F+.

[0291] These two cut areas are now considered as contiguous sub-areas of the critical structure S, and in both manufacturing layers F, F+, fill areas B are created around these cut areas, overlapping in vertical projection (visible on the right in the figure).

[0292] Figure 4 outlines a preferred variant of the method in which consolidation paths are generated as fill areas B. For example, the variant of the method according to Figure 3 can be applied, where the fill areas B are formed by consolidation paths, as indicated here by arrows. This variant can be applied after outputting layer data SD to modify control commands PS. The following steps are preferably used:

[0293] - Identifying critical structures S in the model M (e.g., Figure 3 or the gyroid structure on the left),

[0294] - Identifying critical areas in the layer data SD where a critical structure S has holes or is separated into substructures, deviating from its shape in the model M (e.g. Figure 3 or the gyroid structure on the left),

[0295] - Creating control commands PS to fabricate an object 2 from the layer data SD, whereby hardening paths are added in the critical areas, designed to fill a hole in the respective critical area or to join substructures together. In the middle illustration, the holes in the gyroidal structure are closed by means of additional parallel hatch lines, and in the middle illustration, by means of circular hardening paths. Figure 5 outlines a preferred particular variant of the method in which a determined critical structure S of the model M (shown here on the left) is extended (shown here on the right).

[0296] Figure 6 illustrates this expansion in more detail. A section of a critical structure S is expanded horizontally and / or vertically, with the degree of expansion depending on the structure's slope—that is, how steep it is between the manufacturing layers F, F+, and F-. On the left, expansion is exclusively vertical, demonstrating its suboptimal nature for very steep sections. In the center, expansion is exclusively horizontal, proving suboptimal for very shallow sections. On the right, expansion is vertical in shallow sections and horizontal in steep sections, revealing a regular expansion pattern.

[0297] The critical structure S is preferably extended horizontally by an amount corresponding to a focus size of the energy beam 22, in particular by extruding the critical structure S horizontally by at least half the focus size in opposite directions or by at least one focus size in one direction. The critical structure S is preferably extended vertically by an amount A, by extruding the critical structure S vertically by at least A / 2 in opposite directions or by at least A in one direction. In principle, the dimensions of the extension are arbitrary, but should be at least on the order of the aforementioned dimensions.

[0298] A plurality of points on the critical structure S are then defined, and for each point, a trajectory angle of the critical structure S is determined. If the angle is shallower to the horizontal than to the vertical, a vertical extension of the critical structure S is carried out at that point, and if the angle is shallower to the vertical than to the horizontal, a horizontal extension of the critical structure S is carried out at that point.

[0299] Figure 7 illustrates a preferred variant of the method in which a fill area B in the form of blocks or voxels is created for a critical structure S of the model M (shown here on the left). The critical structure S is recreated from voxels that have side lengths A, corresponding to the distance between the manufacturing layers F, F+, F-. Each voxel thus intersects the position of at least one manufacturing layer F, F+, F-. Figure 8 illustrates a preferred variant of the method in which fill areas B are generated directly on the manufacturing layers F, F+, F-. Layer areas are created at the positions of the manufacturing layers F, F+, F- in the model M or directly on the manufacturing layers F, F+, F-, which correspond to the respective fill areas B. As can be seen in the right-hand illustration, the projections of the critical structure S (left) onto the manufacturing layers F, F+, F- are represented in the form of fill areas B.These filling areas B overlap, so that adjacent layers hold together well and are completely closed during the manufacturing of the object.

[0300] Figure 9 outlines a preferred special variant of the process in which fill regions B are generated by deforming the critical structure S. Two examples of critical structures S are shown above: an intersection of thin structures (left) and a saddle-shaped thin structure that largely lies between two manufacturing layers F, F+, F-. Below are the deformations in which important parts of the structures have been deformed to form fill regions. On the left, the important intersection point has been drawn onto a manufacturing layer F-, and on the right, the saddle-shaped structure.

[0301] Figure 10 illustrates a preferred variant of the process in which fill areas B are generated by copying and horizontally shifting the critical structure S. The solid line represents the critical structure S, and the dashed line represents its shifted copy. The solid circles represent the solidification paths V or the melt pool V during manufacturing. It is clearly visible that these do not overlap in the manufacturing layers F+, F, F-. However, if the copy of the critical structure S is shifted in the direction of the arrow by a predetermined distance, here one diameter of the focal point, new solidification paths V (indicated by dashed lines) are added, and the totality of all now existing solidification paths (or melt pools V) results in a structure that overlaps in the manufacturing layers F+, F, F-.

[0302] Finally, it should be noted once again that the invention described in detail above merely represents exemplary embodiments, which can be modified in various ways by a person skilled in the art without departing from the scope of the invention. Furthermore, the use of the indefinite articles "a" or "an" does not preclude the possibility that the features in question may be present multiple times. Likewise, terms such as "unit" do not preclude the possibility that the components in question consist of several interacting sub-components, which may also be spatially distributed. The term "a number" should be read as "at least one." List of reference numerals

[0303] 1 manufacturing device

[0304] 2 Component / Object

[0305] 3 Process room / Process chamber

[0306] 4 chamber wall

[0307] 5 containers

[0308] 6 Container wall

[0309] 7 Working level

[0310] 8 Building plot

[0311] 10 carriers

[0312] 11 Base plate

[0313] 12 building platforms

[0314] 13 Construction material (in container 5)

[0315] 14 storage containers

[0316] 15 Assembly material (in storage container 14)

[0317] 16 coaters

[0318] 17 Radiant heating

[0319] 18 Sensor arrangement

[0320] 20 Irradiation device / Exposure device

[0321] 21 lasers

[0322] 22 Laser beam / energy beam

[0323] 23 Deflection device / Scanner

[0324] 24 Focusing device

[0325] 25 coupling windows

[0326] 29 Control unit

[0327] 30 Control unit

[0328] 31 Irradiation control interface

[0329] 32 Device

[0330] 33 Data interface

[0331] 34 Unit of measurement

[0332] 35 selection unit

[0333] 36 Filling area unit

[0334] 37 Modification Unit

[0335] 38 Layer Data Generation Unit

[0336] 39 Control data generation unit

[0337] 40 Terminal 60 Bus

[0338] B Filling area

[0339] F manufacturing layer

[0340] F+ manufacturing layer F- manufacturing layer

[0341] HS heating control data

[0342] M Model

[0343] MD model data

[0344] PS Process control data / Control commands S structure

[0345] SD shift data

[0346] ST coating control data

[0347] TS T carrier tax data

[0348] V Solidification path / Melt bath

Claims

55 Patent claims 1. Method for improving the quality of a layer-by-layer additively manufactured object (2) which is manufactured from a geometric model (M) by solidifying build material in defined manufacturing layers (F, F+, F-) by an energy beam (22), the method comprising the steps: - Providing model data (MD) comprising geometric data of the model (M), - Defining the positions of the manufacturing layers (F, F+, F-), where two adjacent manufacturing layers (F, F+, F-) are parallel to each other at a distance A, - Selection of a number of critical structures (S) of the model (M) based on the model data (MD) and / or a previously manufactured object (2) and / or process control data (PS), - Generating a number of fill areas (B), wherein each fill area (B) comprises an area at the position of a manufacturing layer (F) which fully covers at least one vertical projection of a sub-area of ​​a selected critical structure (S) between the positions of this manufacturing layer (F) and an adjacent manufacturing layer (F+, F-), and fill areas (B) of contiguous sub-areas of a selected critical structure (S) overlap in vertical projection at positions of adjacent manufacturing layers (F, F+, F-). - Using the fill areas (B) to modify the model (M) and / or to modify or create layer data (SD) of the model (M) and / or control data to manufacture an object (2) based on the model (M).

2. The method of claim 1, wherein the selection of the number of critical structures - by specifying a number of critical structures (S) in the model (M), and / or - by identifying a number of critical structures (S) according to predefined criteria in the model (M), and / or - by comparing the model (M) with the sliced ​​model (M), where a critical structure (S) in the model (M) forms a closed surface and in the sliced ​​model (M) has a wall thickness below a specified minimum thickness or has a hole or gap, and / or - by comparing the model (M) with an object (2) created according to the model (M), wherein a critical structure (S) in the model (M) forms a closed surface and in the object (2) has a wall thickness below a specified minimum thickness or has a hole or gap, and / or 56 - by determining the intersection points of a continuous structure (S) in the model (M) with the positions of two adjacent manufacturing layers (F, F+, F-), preferably wherein a critical structure (S) is a structure (S) with a thickness less than 4A, preferably less than A, and in particular is a two-dimensional structure (S) and extends over a distance greater than A between two manufacturing layers (F, F+, F-) without touching them.

3. A method according to any of the preceding claims, wherein a number of critical structures (S) of the model (M) are selected, and wherein the model (M) is modified based on the fill areas (B), preferably before generating layer data (SD) of the model (M), preferably wherein when generating a fill area (B), - Layer areas are created at the positions of the manufacturing layers (F, F+, F-) in the model (M), which correspond to the relevant fill areas (B), and / or - the critical structure (S) is formed from voxels with predetermined dimensions, preferably wherein each voxel intersects the position of a manufacturing layer (F, F+, F-) and / or each voxel has a height of at least A, and / or - a critical structure (S) is deformed and / or displaced such that it results in overlapping fill areas (B) at a number of positions of adjacent manufacturing layers (F, F+, F-), preferably wherein the model (M) is modified such that, in projection, adjacent fill areas (B) at positions of adjacent manufacturing layers (F, F+, F-) have a predetermined overlap, in particular layer areas are designed to be correspondingly large and / or voxels are designed or arranged accordingly and / or a critical structure (S) is deformed accordingly.

4. Method according to claim 3 wherein at least one identified critical structure (S) of the model (M) is extended, preferably wherein a horizontal and / or vertical extension of a sub-area of ​​a critical structure (S) depends on its slope, preferably wherein: - the critical structure (S) is extended horizontally by an amount corresponding to a focus size of the energy beam (22), in particular wherein the critical structure (S) is extruded horizontally by at least half the focus size in opposite directions or at least one focus size in one direction, and / or - the critical structure (S) is extended vertically by an amount which preferably corresponds to at least the distance A, in particular wherein the critical structure (S) is extruded vertically by at least A / 2 in opposite directions or at least A in one direction, 57 preferably wherein a plurality of points on the critical structure (S) is defined, a trajectory angle of the critical structure (S) is determined for each point, and in the case that the angle is shallower to the horizontal than to the vertical, a vertical extension of the critical structure (S) is carried out at that point, and in the case that the angle is shallower to the vertical than to the horizontal, a horizontal extension of the critical structure (S) is carried out at that point.

5. Method according to any of the preceding claims, comprising the additional steps: - Creating layer data (SD) of the model (M) from the cross-sectional surfaces of the model (M) with planes at the positions of the manufacturing layers (F, F+, F-), - Output of the layer data (SD), preferably wherein control commands (PS) for the manufacture of an object (2) according to the layer data (SD) are generated from the layer data (SD), preferably wherein the layer data (SD) is created from a modified model (M) according to one of claims 3 or 4.

6. Method according to claim 5, wherein layer data (SD) are created from intersection surfaces of a number of fill areas (B) with planes at the positions of the manufacturing layers (F, F+, F-), wherein the fill areas (B) are surfaces or volumes at the position of the manufacturing layers (F, F+, F-) and are not part of the model (M), preferably wherein additional fill areas (B) are taken into account during and / or after the creation of layer data (SD) of the model (M) from the intersection surfaces of the model (M) with planes at the positions of the manufacturing layers (F, F+, F-).

7. The method of claim 6 wherein a corresponding filling area (B) is generated by: - Extending at least one identified critical structure (S) of the model (M), preferably wherein a horizontal and / or vertical extension of a sub-area of ​​a critical structure (S) depends on its slope, and / or - Moving a copy of a number of points of the model (M) in each critical structure (S) to at least one of the adjacent manufacturing layers (F, F+, F-), preferably the nearest one, and / or - Creating layer areas on the manufacturing layers (F, F+, F-) that correspond to the relevant filling areas (B), preferably by vertical projection of the sub-areas onto the manufacturing layers (F, F+, F-), and / or - Forms of blocks with a minimum height of A at the position of sub-areas of a critical structure (S), preferably wherein each block occupies the space between two sections of the 58 critical structure (S) with the positions of two adjacent manufacturing layers (F, F+, F-), and preferably slicing the blocks, and / or - Reshaping the critical structure (S) from voxels with predetermined dimensions, preferably wherein each voxel intersects the position of a fabrication layer (F, F+, F-), and preferably slicing the voxels.

8. Method according to any one of claims 5 to 7, wherein, after outputting the layer data (SD), control commands (PS) are modified by adding additional solidification paths (V), preferably according to the steps: - Identifying critical structures (S) in the model (M), - Identifying critical areas in the layer data (SD) where a critical structure (S) differs from its shape in the model (M), has holes, or is separated into substructures, - Creating control commands (PS) to manufacture an object (2) from the layer data (SD), adding solidification paths (V) in the critical areas, designed to fill a hole in the critical area in question or to join substructures together, - Output of tax data.

9. A method according to any of the preceding claims, wherein, after a slicing process, cutting areas in manufacturing layers (F, F+, F-) are identified which have an area below a predetermined limit value, and these cutting areas are defined as critical areas, preferably wherein it is checked whether cutting areas in two adjacent manufacturing layers (F, F+, F-) belong to a connected structure (S) in the model (M), and in this case both cutting areas are jointly assigned to a critical structure (S), preferably wherein the two cutting areas are considered as connected sub-areas of a selected critical structure (S), and in both manufacturing layers (F, F+, F-) fill areas (B) are created around these cutting areas which overlap in vertical projection.

10. Device (32) for improving the quality of a layer-by-layer additively manufactured object (2) which is produced from a geometric model (M) by solidifying build material in defined manufacturing layers (F, F+, F-) by means of an energy beam (22), the device (32) comprising: - a data interface (33) designed to receive model data (MD) comprising geometric data of the model (M), - a fixing unit (34) designed to fix positions of the manufacturing layers (F, F+, F-) wherein two adjacent manufacturing layers (F, F+, F-) are parallel to each other at a distance A, - a selection unit (35) designed to select a number of critical structures (S) of the model (M) based on the model data (MD) and / or a previously manufactured object (2) and / or process control data (PS), - a fill area unit (36) designed to generate a number of fill areas (B), wherein each fill area (B) comprises an area at the position of a manufacturing layer (F) which fully covers at least one vertical projection of a sub-area of ​​a selected critical structure (S) between the positions of this manufacturing layer (F) and an adjacent manufacturing layer (F+, F-), and fill areas (B) of contiguous sub-areas of a selected critical structure (S) overlap in vertical projection at positions of adjacent manufacturing layers (F, F+, F-). - a modification unit (37) designed to use the fill areas (B) to modify the model (M) and / or to modify layer data (SD) of the model (M) and / or control data to manufacture an object (2) based on the model (M).

11. Device (32) according to claim 10 further comprising a layer data generation unit (SD) (38) designed for creating layer data (SD) of the model (M) from the cross-sectional surfaces of the model (M) with planes at the positions of the manufacturing layers (F, F+, F-), preferably wherein layer data (SD) is created from cross-sectional surfaces of a number of fill areas (B) with planes at the positions of the manufacturing layers (F, F+, F-), and preferably also for creating a fill pattern from lines, and preferably further comprising a control data generation unit (39) designed for modifying or creating control commands (PS) from layer data (SD).

12. Shift data (SD) characterized in that it has been created using a method according to one of claims 5 to 8, preferably by means of a device (32) according to claim 10 or 11.

13. Control device (30) for a manufacturing device (1) for the additive manufacturing of a component (2) in a manufacturing process in which build material, preferably comprising a plastic powder or metal powder, is built up layer by layer in a build area (8) and selective solidification of the build material by irradiation of the build material with at least one energy beam (22) is used, the control device (30) comprising a device (32) according to claim 10 or 11.

14. Manufacturing device (1) for the additive manufacturing of at least one object (2) in an additive manufacturing process comprising at least - a feeding device for applying layers of build material in a build area (8) into a process chamber (3), - an irradiation device (20) for selectively solidifying build-up material between the application of two material layers by irradiation with at least one energy beam (22), as well as - a control device (30) according to claim 13.

15. Computer program product comprising a computer program which can be directly loaded into a storage device of a computing device, in particular a control device (30) of a manufacturing device (1) for the additive manufacturing of a component layer (2) of a component (2), comprising program sections to execute all steps of the method according to any one of claims 1 to 9 when the computer program is executed in the computing device.

Images