Method for planning local solidification of layers of powdered material during layer-by-layer production of three-dimensional objects

Abstract

The invention relates to a method for planning the local solidification of layers of powdered material during the layer-by-layer production of a three-dimensional object, comprising the following steps: step a): determining at least one inner surface region (15 (II)) and at least one lower surface region (14 (II)) in contiguous regions (18 (I)) of the layer (7) to be solidified; step b): defining, for each inner surface area (15 (II)), an inner surface pattern (21) having inner surface vectors (1 ', 3', 4 ', 6', 7 ', 9', 10 ', 12', 13 '), and defining, for each lower surface area (14 (II)), a lower surface pattern (22) comprising lower surface vectors (2', 5 ', 8', 11 ', 14'), the defining of the inner surface pattern (21) being performed independently of the defining of the lower surface pattern (22); step c): defining a processing sequence of all the inner surface vectors (1 ', 3', 4 ', 6', 7 ', 9', 10 ', 12', 13 ') and the lower surface vectors (2', 5 ', 8', 11 ', 14'); the method is characterized in that, in step c), a plurality of inner surface vector blocks (23a, 23b) and a plurality of lower surface vector blocks (24a, 24b) are defined, the inner surface vector blocks each comprising one or more inner surface vectors (1 ', 3', 4 ', 6', 7 ', 9', 10 ', 12', 13 ') to be continuously processed, and the lower surface vector blocks each comprising one or more lower surface vectors (2', 5 ', 8', 11 ', 14') to be continuously processed, and defining a sequence of vector blocks processing the inner surface vector blocks (23a, 23b) and the lower surface vector blocks (24a, 24b) in which the inner surface vector blocks (23a, 23b) and the lower surface vector blocks (24a, 24b) alternate. By means of the invention, a high-quality, accelerated exposure of the connected lower surface region (14 (II)) and inner surface region (15 (II)) is carried out while avoiding overheating of these regions.

Description

Technical Field

[0001] The invention relates to a method for planning the local solidification of layers of powdered material using a high-energy beam in the layer-by-layer production of a three-dimensional object.

[0002] The method has the following steps:

[0003] Step a): at least one inner surface region and at least one lower surface region are defined in the connected regions of the layer in which the solidification of the powdered material is to be carried out using the high-energy beam,

[0004] Step b): defining, for each inner surface region, an inner surface pattern, the inner surface pattern determining in the inner surface region a geometric extension of a plurality of inner surface vectors for the high energy beam, and defining, for each lower surface region, a lower surface pattern, the lower surface pattern defining in the lower surface region a geometric extension of a plurality of lower surface vectors for the high energy beam,

[0005] wherein the definition of the one or more inner surface patterns within at least one inner surface region is independent of the definition of the one or more lower surface patterns within at least one lower surface region;

[0006] Step c): Defines the processing sequence of all inner and lower surface vectors. Background Art

[0007] From EP 3 563 203 B1 Figure 4 Such a process is known.

[0008] The method for layer-by-layer production of three-dimensional objects, also known as 3D printing, enables the production of such objects with great freedom of design and with relatively little expenditure of time. These objects are produced layer by layer from powder, wherein the layers are locally irradiated with a high-energy beam in order to solidify them. During the production method, the movement of the high-energy beam on the layer to be processed is defined here by a vector.

[0009] The layer to be processed is usually divided into parts, in which the vector of the high-energy beam and / or the assigned parameters are selected differently. It is important here to distinguish between the inner surface area and the lower surface area. In the framework of the present application, the inner surface area is particularly understood as the following section of the layer to be processed, which is positioned on a part of the powder layer placed below and solidified during the manufacture of the object. In the framework of the present application, the lower surface area is particularly understood as the following section of the layer to be processed, which is positioned on a part of the powder layer placed below and remains unsolidified during the manufacture of the object. The lower surface vector is used to process the lower surface area. Accordingly, the inner surface vector is used to process the inner surface area, and the inner surface vector can be different from the lower surface vector, for example, with respect to its line energy or its length.

[0010] EP 3 563 203 B1 Figure 4 A method for manufacturing an object layer by layer is disclosed, wherein the layer of the object has a sandwich region and a lower surface region adjacent to the sandwich region. A high energy beam is initially guided along parallel shadow lines in one of the two regions to cure the region in question. Then, the high energy beam is guided along parallel shadow lines in the other of the two regions in a corresponding manner to cure the other region as well. Thus, curing of one region is completed before curing of the other region begins. Such a method is relatively easy to implement.

[0011] If during this layer-by-layer production of three-dimensional objects using a high-energy beam in the inner surface area or in particular in the lower surface area, all consecutive vectors are directly exposed one after the other, there is a risk of local overheating, which leads to reduced buildability. Overheating can be avoided by waiting times. However, this increases the processing time and reduces the productivity of the production method.

[0012] In EP 3 563 203 B1 Figure 4 b, the following method is also disclosed: in this method, the high-energy beam is guided along a continuous shadow line above the boundary line between the lower surface area and the sandwich area, wherein when changing between the lower surface area and the sandwich area, the beam parameters of the high-energy beam are changed to adapt to the corresponding area. This method is intended to reduce thermal stress on the boundary surface between the lower surface area and the sandwich area.

[0013] However, by using continuous hatching, the characteristics of both the lower surface area and the sandwich area must be considered when selecting the vectors. The pattern of the vectors is generated by a compromise between the characteristics of the two areas. This makes it difficult to select the vectors optimally for the respective area, for example with regard to the density of the vectors. Often, the lower surface area is therefore not optimally treated.

[0014] US 9676032 B2 relates to a method for layer-by-layer production of a three-dimensional object, wherein a first region of a powder layer is exposed by a high-energy beam with parallel scan lines in a first direction, and a second region is exposed with parallel scan lines in a second direction. Here, the scan lines in the first region are exposed or melted immediately before the scan lines in the second region. After applying a further powder layer, the first region is exposed on parallel scan lines in a third direction, and the second region is exposed on parallel scan lines in a fourth direction. The method aims to reduce the time required to produce an object.

[0015] FIG. 12 of DE 10 2017 126 624 A1 discloses selective coating in overhang areas in the generative production of three-dimensional components, wherein the inner surface pattern and the lower surface pattern are planned together.

[0016] Invention Task

[0017] The object of the present invention is to propose a method for planning the local solidification of powder material layers using a high-energy beam during the layer-by-layer production of three-dimensional objects, using which method high-quality, accelerated exposure of connected lower and inner surface areas can be carried out while avoiding overheating of these areas. Summary of the invention

[0018] This object is achieved according to the invention by a method according to claim 1. Advantageous embodiments are revealed in the dependent claims.

[0019] The method according to the invention is characterized in that, in step c), a plurality of inner surface vector blocks and a plurality of lower surface vector blocks are defined,

[0020] wherein the corresponding inner surface vector block includes one or more inner surface vectors that should be processed continuously, and the corresponding lower surface vector block includes one or more lower surface vectors that should be processed continuously,

[0021] A vector block sequence for processing inner surface vector blocks and lower surface vector blocks (hereinafter collectively referred to as vector blocks) is defined, and the inner surface vector blocks and lower surface vector blocks are alternated in the vector block sequence.

[0022] The alternating treatment of inner surface blocks and lower surface blocks according to the invention reduces the risk of local overheating of the connected areas of the layer and reduces the waiting time at the same time. The lower surface area is particularly susceptible to local overheating, since the heat dissipation by the uncured powder in the layer disposed below is lower than the heat dissipation by the cured powder. The invention reduces the risk of overheating, in particular in the lower surface area, since after the lower surface block has been treated, the material in the lower surface area can cool down again while the inner surface block following the lower surface block in the vector block sequence is treated. Within the scope of the method, the time interval used for cooling the lower surface area after the treatment of the lower surface block is at least partially used for the treatment of the inner surface block, whereby the waiting time during which the connected areas of the layer are not exposed due to the risk of overheating can be shortened or even completely eliminated. This speeds up the exposure of the connected areas without reducing the treatment quality of the inner surface area and the lower surface area.

[0023] The vector (inner surface vector or lower surface vector) can be a straight segment extending on the layer at the high-energy beam incident point, or can be composed of a vector column of connected partial vectors, wherein the partial vectors in particular respectively represent straight segments extending on the layer at the high-energy beam incident point, and typically wherein consecutive partial vectors have different extension directions from one another.

[0024] Typically, a vector block includes 1 vector to 10 vectors, and typically also only a single vector or two vectors. For a typical object, each layer typically forms at least 10, typically tens or hundreds of inner surface vectors and at least 10, typically tens or hundreds of lower surface vectors. Typically, at least 5 and typically at least 10 inner surface vector blocks are also formed for the connected areas of the layer, and at least 5 and typically at least 10 lower surface vector blocks are further formed.

[0025] The inner surface pattern and the lower surface pattern are defined independently of each other, in particular because: no information about the inner surface pattern (and in particular the position of the individual inner surface vectors) is needed or applied to define the lower surface pattern (and in particular the position of the individual lower surface vectors), and vice versa. For the independent definition of the inner surface pattern and the lower surface pattern, it is basically sufficient to know the geometry (extension / extension) of the corresponding inner surface area or lower surface area. For example, completely different patterns (e.g. offset fill, stripes or checkerboard patterns) can be selected for the lower surface and the inner surface. The independent definition of the lower surface pattern and the inner surface pattern does not exclude the existence of parameters that are applicable to both (and all other) patterns, such as the orientation of the stripes composed of vectors or the position of the origin from which the surface to be exposed is divided into stripes. In particular, the inner surface pattern and the lower surface pattern can be defined independently of each other in that adjacent inner surface vectors in the inner surface pattern are at least predominantly at a different distance from each other than adjacent lower surface vectors in the lower surface pattern, and / or the inner surface vectors are at least predominantly oriented obliquely to the lower surface vectors.

[0026] The connected area to be exposed has a profile, wherein a profile shift of the high-energy beam can be performed within the framework of the manufacturing method. The profile shift is defined by one or more vectors arranged adjacent to the profile and oriented along the profile. In particular, the exposure in the lower surface area can include a profile shift and provide a corresponding lower surface vector.

[0027] Preferred variations of the invention

[0028] A preferred variant of the method according to the invention is characterized in that, in step c), the vector blocks are defined such that in respective two consecutive vector blocks in the sequence of vector blocks, the respective end point of the last vector of the preceding vector block in the layer is at least predominantly spatially spaced apart from the starting point of the first vector of the succeeding vector block.

[0029] In this configuration, the lower surface area and the inner surface area are exposed alternately, wherein, in the sequence of vector blocks, there is a distance between the end point of the last vector of the previous vector block in the layer and the starting point of the first vector of the next vector block, at which distance no irradiation with the high-energy beam occurs during the change between the vector blocks. Within the framework of the present application, this is particularly referred to as discontinuous exposure. By sufficiently spacing the aforementioned end point from the aforementioned starting point, the heat exchange between the previously exposed sub-area of ​​the connected area and the subsequently exposed sub-area is reduced. The powder in the connected area is only locally heated in the sub-area determined by the vector blocks, respectively, and can be cooled again relatively quickly. The locally limited heating prevents the high-energy beam from further heating the sub-area to be treated, which has already been heated by the heat flow from the adjacent sub-area. The risk of local overheating is further reduced and the waiting time can be further reduced.

[0030] A variant of the method is advantageous in which, in step c), the vector blocks are defined so that, at least primarily in two respective consecutive vector blocks in the sequence of vector blocks, the extension direction of the last vector of the preceding vector block in the layer is inclined to the extension direction of the first vector of the succeeding vector block. This enables the orientation of the vectors to be flexibly adapted to the shape of the connected areas and to the shape of the lower surface area and the inner surface area. In particular, the vectors can be guided along the boundary lines of the connected areas by the orientation of the vectors at corners or curves. Alternatively or additionally, the distances of adjacent lower surface vectors can be selected within the scope of the method to be different from the distances of adjacent inner surface vectors. This enables the density of the lower surface vectors and the inner surface vectors to be adapted to the shape and extension of the lower surface area and the inner surface area, respectively.

[0031] In a further variant of the method according to the invention, the inner surface vector and the lower surface vector are defined such that at least mainly the inner surface vector extends obliquely to the lower surface vector. Thus, the extension of the inner surface vector and the lower surface vector can be adapted in particular to an angle or a curve at the boundary surface between the inner surface area and the lower surface area.

[0032] An advantageous variant of the method according to the invention is characterized in that, at least in a majority of the inner surface patches of the corresponding inner surface vector patches,

[0033] - an inner surface vector block contains at least a first inner surface vector and a last inner surface vector,

[0034] - and the included inner surface vectors are selected such that the starting point of the first inner surface vector is located near the end point of the last inner surface vector, in particular, wherein the starting point and the end point have the following spacing,

[0035] - the spacing is less than 1 / 4 of the length of the longest inner surface vector of the inner surface vector block, preferably less than 1 / 10 of the length of the longest inner surface vector of the inner surface vector block, and / or

[0036] - the spacing is less than 25 times the shadow spacing in the inner surface vector block, preferably less than 10 times the shadow spacing in the inner surface vector block, and / or

[0037] - The spacing is smaller than 2.5 mm, preferably smaller than 1.0 mm.

[0038] This can help reduce non-productive downtime during layer exposure. Typically, lower surface blocks to be processed successively are close together, and inner surface blocks to be processed successively are also close together, and the lower surface blocks are relatively small compared to the inner surface blocks. By arranging the start / end points of the inner surface blocks close to the lower surface blocks (within the corresponding portion of the exposure period of the connected area), the travel path of the high energy beam can be minimized when changing between vector blocks in the vector block sequence.

[0039] In other words: by having the starting point of the first inner surface vector approach the end point of the last inner surface vector, the lower surface vector block processed before the inner surface vector block in question in the vector block sequence and the lower surface vector block processed after the inner surface vector block in question in the vector block sequence can be positioned close to each other. Here, when switching between the inner surface vector block and the lower surface vector block, there is no need to reposition the high-energy beam (after deactivation) over a long distance.

[0040] The extended scheme of the above-mentioned variant is characterized in that the starting point of the first inner surface vector is adjacent to the boundary surface between the inner surface area to which the inner surface vector block is assigned and the adjacent lower surface area, and the first inner surface vector is guided away from the adjacent lower surface area from the starting point, and finally the inner surface vector is guided back to the adjacent lower surface area. Therefore, after processing the lower surface block of the adjacent lower surface area, the high-energy beam is positioned relatively close to the starting point of the first inner surface vector of the inner surface vector block of the inner surface area, and can be quickly guided to the starting point. After processing the inner surface vector block assigned to the first inner surface vector, the high-energy beam is again positioned close to the adjacent lower surface area, and can be quickly guided to the next lower surface vector block in the adjacent lower surface area in the processed vector block sequence.

[0041] A variant of the method according to the invention is preferred, in which, at least in the majority of the inner surface patches, the respective inner surface patch is formed by an even number, in particular two, four or six, inner surface vectors arranged side by side, which have alternating opposite extension directions, in particular, in which the inner surface vectors extend parallel to one another. The parallel orientation of the vectors is advantageously used for shading to create a structurally simple shading pattern, which serves to guide the high-energy beam during the exposure of the adjacent areas. Due to the even number of vectors, the starting point of the first vector and the end point of the last vector can be close together, in particular in the case of inner surface vectors arranged side by side having approximately the same length.

[0042] In another variant, at least in some of the lower surface vectors, the extension of the corresponding lower surface vector follows the extension of the adjacent contour, especially the outer contour, of the assigned lower surface area. This makes it possible to treat the lower surface area in a simple manner by a high-energy beam along the contour of the lower surface area, preferably in the form of contour movement, outlining the contour, especially along the curve or angle of the contour in the lower surface area. In particular, the lower surface area can be increased outward on the manufactured partial section of the inner surface area, which is conducive to rapid heat dissipation and prevention of overheating. In this regard, in particular, a plurality of lower surface vectors can be set for the contour section at different distances from the contour, and the lower surface vectors follow the extension of the contour.

[0043] A variant of the method according to the invention is advantageous, characterized in that, in step c), the inner surface vector block and the lower surface vector block are defined as follows: on the corresponding boundary surface segment between the inner surface area and the lower surface area, all inner surface vectors at least partially located on or near the boundary surface segment are first processed, and then all lower surface vectors at least partially located on or near the boundary surface segment are processed. By processing the inner surface area before the adjacent lower surface area, the heat flow from the connected area is improved because the heat can flow at least partially from the lower surface area to the inner surface area. Compared with directly flowing out from the lower surface area with unsolidified (unmelted) powder below it, the heat flows out from the inner surface area better. The configuration of the method makes it possible to cool the area (especially the lower surface area) treated with a high-energy beam in the connected area more quickly. In particular, if significant heat conduction is carried out through the boundary surface segment when manufacturing the vector, the vector is considered to be close to the boundary surface segment. The length of the boundary surface segment can, for example, correspond to the length of the adjacent lower surface vector.

[0044] An extension of the aforementioned variant is characterized in that at least partially the lower surface vectors that are closer to the boundary surface segment are processed before the lower surface vectors that are farther away from the boundary surface segment. Thus, during the processing of the lower surface vectors, it is ensured that the sub-segment of the lower surface region to be exposed, which is determined by the lower surface vectors, is connected to the inner surface region via the boundary surface based on the solidified powder. This leads to an improved heat flow from the lower surface region through the inner surface region during the processing of the lower surface region, so that the lower surface region is cooled more quickly.

[0045] In a preferred variant, within the framework of step c), a waiting time is also defined between at least some consecutive vector blocks of the sequence of vector blocks, during which the treatment with the high-energy beam is suspended. During the waiting time, the connected area cools down between the treatment with the high-energy beam in order to reduce the risk of overheating. Alternatively or additionally, the waiting time can also be set within the vector block.

[0046] A further variant of the method according to the invention is characterized in that

[0047] At least some of the inner surface vector blocks that follow one another in the vector block sequence and that alternate with the lower surface vector blocks are arranged adjacent to one another in the assigned inner surface region, and / or

[0048] At least some of the lower surface vector blocks that follow one another in the vector block sequence and that alternate with the inner surface vector blocks are arranged adjacent to one another in the associated lower surface region.

[0049] By processing adjacent vector blocks in a sequence of vector blocks in succession, connected regions of a connected region are processed, thereby increasing the stability of the connected region during the processing process. In particular, the formation of island-like exposed regions surrounded by unexposed regions is avoided. Such island-like exposed regions can relatively easily change their position or orientation in an undesirable manner (e.g. due to different density and / or intensity of the exposed region relative to the region that has not yet been exposed).

[0050] The scope of the present invention also includes a computer program product which, when used on a control device or a planning device of a 3D printer, executes the method according to the invention described above. Such a computer program product can be distributed independently of a 3D printer or a planning device with little effort, wherein after the computer program product has been installed on a suitable control device or planning device of a 3D printer, the planning method according to the invention can be executed.

[0051] The scope of the present invention also includes a control device for a 3D printer or a planning device, which is programmed to perform the method according to the present invention described above. The control device is used to control the 3D printer and in particular to perform the planning method according to the present invention, in particular according to the instructions of the aforementioned computer program product. Alternatively, a planning device independent of the 3D printer (usually installed on a PC or a server) can be used to perform the method according to the present invention according to the program; the results of the planning method are then transferred to the independent 3D printer to perform the building process.

[0052] The invention also includes a method for layer-by-layer production of a three-dimensional object, in which a powdered material is solidified successively in layers in corresponding local areas using a high-energy beam.

[0053] wherein for at least some of the layers

[0054] - (step α) planning of local solidification in said layer according to the above method according to the invention, and

[0055] - (step β) performing local solidification of the layer according to the plan of step α by treating the inner surface vectors and the lower surface vectors defined in step b) using a high energy beam in the order defined according to step c) for the plan of the layer.

[0056] By planning the exposure of inner and lower surface areas in connected regions according to the invention, a high-quality, accelerated exposure of these areas can be carried out within the framework of the production method.

[0057] The scope of the invention also includes a 3D printer with a control device, wherein the control device is programmed to carry out the above-described manufacturing method according to the invention on the 3D printer. Such a 3D printer is designed to plan and carry out the exposure of the lower surface area and the inner surface area in the connected area according to the invention, so that these areas are processed with high quality and accelerated speed, and in particular without local overheating.

[0058] Other advantages of the present invention are derived from the description and the drawings. Similarly, the above-mentioned features and the features yet to be presented can be used alone or in any combination. The embodiments shown and described should not be understood as an exhaustive enumeration, but should be understood as having exemplary characteristics for describing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 Schematically shows a longitudinal section through an exemplary 3D printer for the layer-by-layer production of a three-dimensional object according to the invention, wherein a high-energy beam exposes the layer to be processed;

[0060] Figure 2A schematic top view of a first embodiment of a connected region of a layer to be treated according to the invention is shown;

[0061] Figure 3 A schematic top view of a second embodiment of a connected region of a layer to be treated according to the invention is shown;

[0062] Figure 4 Schematically showing a top view of a second embodiment of a connected region, wherein only the inner surface vector and the lower surface vector closest to the contour of the connected region are shown;

[0063] Figure 5 A top view schematically shows a third embodiment of a connected area of ​​a layer to be treated according to the invention;

[0064] Figure 6 A top view of a third embodiment of one of the connected areas of a layer to be treated according to the invention is schematically shown, with a lower surface vector and an inner surface vector extending parallel and adjacent to the contour of the connected area. DETAILED DESCRIPTION

[0065] Figure 1 A longitudinal section through an exemplary 3D printer 1 for the layer-by-layer production of a three-dimensional object 2 according to the invention is schematically shown. The object 2 is grown on a substrate 3a, which is arranged on a lifting table 3 in a production chamber 4 of the 3D printer 1, wherein the lifting table 3 enables the substrate 3a and the object 2 to be moved vertically. The object 2 is produced in the production chamber from powder layers 5a, 5b, 5c. To produce the object, powder from the powder layers 5a, 5b, 5c is successively and locally solidified in the powder layers 5a, 5b, 5c using a high-energy beam 6 of the 3D printer 1. Figure 1 At the time shown, within the framework of the manufacturing process, the powder 8 of the (uppermost) layer 7 to be processed is irradiated with a high-energy beam 6 in order to locally solidify the layer 7 to be processed. The uncured powder 8 is marked here by a ring. Accordingly, the object 2 is constructed layer by layer. The high-energy beam 6 is generated in a beam source 16 for this purpose and is directed by a mirror 17. The planned boundary 9 of the object 2 in the layer 7 to be processed is here at Figure 1 The manufacturing process is controlled by a control device 10 of the 3D printer 1. Here, the control device 10 is designed to plan the local curing of the layer 7 to be processed before executing the local curing by means of a computer program product 11 or its program. In addition, the control device 10 also performs the curing of the corresponding layer to be processed.

[0066] Alternatively, a separate planning device 29 can also be provided, on which local solidification of the layer 7 to be processed (indicated by the dotted line) is planned with the aid of the computer program product 11a or its program; the planning device 29 then transmits the received plan to the control device 10, which then controls the actual solidification of the layer 7.

[0067] When planning the localized solidification, a distinction must be made in particular between lower surface areas and inner surface areas of the object 2, wherein reference numerals 12a, 12b indicate examples of lower surface areas of layers 5b, 5c and reference numerals 13a, 13b indicate inner surface areas of layers 5b, 5c which must be taken into account when producing the object 2 in layers 5b, 5c. (I) An exemplary lower surface area of ​​the layer 7 to be treated is indicated, while reference numeral 15 (I) Indicates the inner surface area of ​​the layer 7 to be processed. When the corresponding layer is locally cured using the high-energy beam 6, for example with respect to the position, orientation and density of the vectors and / or beam parameters, the inner surface areas 13a, 13b, 15 (I) The lower surface areas 12a, 12b, 14 (I) Different handling is usually required than with conventional heat treatment, especially to avoid the risk of local overheating.

[0068] Figure 2 The layer 7 to be treated is schematically shown (see Figure 1 ) of the connected area 18 (I) A top view of a first embodiment, wherein in the connected area 18 (I) In the process, the exposure of the layer 7 to be processed should be carried out using a high energy beam. (I) By inner surface area 15 (II) and lower surface area 14 (II) Composition (such as Figure 2 The lower surface area 14 (II) The boundary surface 19 with the boundary surface section and the inner surface area 15 (II) separate, among them, in Figure 2 2 shows, as examples, a boundary surface segment 27a extending approximately in the longitudinal area of ​​the lower surface vector 2' and a boundary surface segment 27b extending approximately in the longitudinal area of ​​the lower surface vector 14'. (II) By Contour 20 (I) Outwardly limited.

[0069] In the planning of connected areas 18 (I) When curing, the inner surface area is 15 (II) Defines the inner surface vector, where Figure 2In the figure, inner surface vectors 1', 3', 4', 6', 7', 9', 10', 12', 13' are marked as examples. The high-energy beam 6 is applied to the inner surface area 15 during the exposure process. (II) The movement in is determined by the inner surface vectors 1', 3', 4', 6', 7', 9', 10', 12', 13'. Accordingly, for the lower surface area 14 (II) , defines the lower surface vector, where Figure 2 In the figure, the lower surface vectors 2', 5', 8', 11', 14' are marked as examples. The lower surface vectors 2', 5', 8', 11', 14' are used to determine the direction of the high energy beam 6 in the lower surface area 14 during the exposure process. (II) Here we can see that in Figure 2 , the lower surface vectors 2', 5', 8', 11', 14' start and end respectively at the marking lines pointing radially outwards.

[0070] Therefore, for the inner surface area 15 (II) An inner surface pattern 21 is determined, which includes inner surface vectors 1', 3', 4', 6', 7', 9', 10', 12', 13' and defines in particular the position, length and / or orientation of the vectors. (II) A lower surface pattern 22 is determined, which includes lower surface vectors 2', 5', 8', 11', 14' and defines in particular the position, length and / or orientation. The inner surface pattern 21 and the lower surface pattern 22 are selected independently of one another during planning. This can be seen here in particular from the fact that the inner surface vectors 1', 3', 4', 6', 7', 9', 10', 12', 13' extend obliquely to the lower surface vectors 2', 5', 8', 11', 14'.

[0071] Figure 2 The connected area 18 is shown from a point in time (I) During the exposure process, the inner surface vectors (not numbered) above the inner surface vector marked with 1' at this point in time have been processed. In the processing sequence of vectors 1' to 13' defined within the planning framework according to the present invention, vectors 1' to 13' are processed in ascending order according to their numbers.

[0072] In the processing sequence, a plurality of inner surface vector blocks and lower surface vector blocks are introduced, wherein Figure 2 In the figure, inner surface vector blocks 23a, 23b and lower surface vector blocks 24a, 24b (see dashed boxes) are shown as examples. Figure 2 In the example, two inner surface vectors 3', 4' and 6', 7' are included respectively, and the lower surface vector blocks 24a and 24b are Figure 2In the example, there are two lower surface vectors 2' and 14'. (I) Within the framework of solidification, the inner surface vectors 1', 3', 4', 6', 7', 9', 10', 12', 13' or the lower surface vectors 2', 5', 8', 11', 14' are processed continuously in their corresponding vector blocks 23a, 23b or 24a, 24b.

[0073] In the processing sequence, the inner surface vector 1' is now processed first to alternately expose the inner surface region 15 (II) and lower surface area 14 (II) Subsequently, the lower surface vector 2' is processed in the lower surface vector block 24a. Thereafter, the inner surface vectors 3' and 4' are processed in the inner surface vector block 23a, wherein the high energy beam 6 on the inner surface vector 3' is transmitted from the lower surface region 14 (II) Remove and then again on the inner surface vector 4' (II) The upper part is then directed to the lower surface region 14. The lower surface vector 5' is then processed. Next, the inner surface vectors 6' and 7' are processed in the inner surface vector block 23b. Next is the lower surface vector 8'. Then, the inner surface vectors 9' and 10' are processed. Then, the closest contour 20 is processed. (I) Then, the inner surface vectors 12' and 13' are processed. Next, the lower surface vector 14' in the lower surface vector block 24b is processed.

[0074] The lower surface vectors 2 ′, 5 ′, 8 ′, 11 ′ are produced successively (alternating with the inner surface vector segments, in particular 23 a and 23 b ), so that the material melts from the inside outwards at the boundary surface section 27 a .

[0075] Since inner surface vectors 1 ', 3', 4', 6', 7', 9' and 10' have already been processed before lower surface vector 14' begins, lower surface vector 14' can be used to melt material on boundary surface segment 27b, wherein boundary surface segment 27b has already solidified.

[0076] In order to make the travel path of the high energy beam 6 (see Figure 1 ) is minimized, where the inner surface vectors 1', 3', 4', 6', 7', 9', 10', 12', 13' are selected so that in an inner surface vector block, for example, in the inner surface vector block 23a, (in the sequence of processing) the starting point 25 of the first inner surface vector (here 3' is used as an example) is located near the end point 26 of the last inner surface vector (here 4' is used as an example) in the relevant inner surface vector block 23a. In addition, the starting point 25 of the first inner surface vector 3' is adjacent to the boundary surface 19, which is located in the inner surface region 15 of the inner surface vector block 23a. (II)With lower surface area 14 (II) between, so that the high energy beam 6 (see Figure 1 ) can be from the lower surface area 14 (II) Quickly change to the inner surface vector block 23a. Here, the first inner surface vector 3' is directed away from the starting point 25 and away from the adjacent lower surface area 14 (II) , and finally the inner surface vector 4' is directed back to the adjacent lower surface region 14 (II) , whereby the high energy beam 6 can quickly return to the lower surface region 14 after processing the inner surface vector block 23a (II) The first inner surface vector 3' and the last inner surface vector 4' are antiparallel to the effective guidance of the high energy beam 6, ie the first inner surface vector and the last inner surface vector have alternating opposite extension directions.

[0077] In order to heat the connected area 18 only locally during exposure, (I) , the vector blocks 23a, 23b, 24a, 24b are preferably defined so that the corresponding end points of two consecutive vector blocks 24a, 23b in the vector block sequence (here, the end point 28 of the last vector 2' of the previous vector block 24a as an example) are spatially separated from the starting point of the subsequent vector block (here, the starting point 25 of the first vector 3' of the subsequent vector block 23b as an example).

[0078] Figure 3 The layer 7 to be treated is schematically shown (see Figure 1 ) of the connected area 18 (II) A top view of a second embodiment of the present invention. Figure 3 The connected area 18 shown in (II) By inner surface area 15 (III) and the first lower surface area 14 (III) and the second lower surface area 14 (IV) composition, which adjoins the inner surface area 15 (III) On, wherein the inner surface area 15 (III) Here, in the two lower surface areas 14 (III) , 14 (IV) between.

[0079] In order to guide the high energy beam 6 (see Figure 1 ), in the inner surface area 15 (III)In the second embodiment, inner surface vectors are defined, some of which are exemplarily labeled as 1", 2", 4", 5", 8", and in the lower surface region, lower surface vectors are defined, some of which are exemplarily labeled as 3", 6", 7", 12", and 9", 10", 11". In this second embodiment, some of the lower surface vectors (e.g., lower surface vectors 3", 6") extend antiparallel to each other to enable efficient guidance of the high energy beam 6 (see Figure 1 ). Here, the lower surface vectors 3", 6", 7", 12" and 9", 10", 11" are oriented obliquely or perpendicularly to the inner surface vectors 1", 2", 4", 5", 8", whereby the lower surface vectors 3", 6", 7", 12" and 9", 10", 11" are selected in particular independently of the inner surface vectors 1", 2", 4", 5", 8".

[0080] The inner surface vectors are combined into inner surface vector blocks, wherein inner surface vector blocks 23c and 23d are shown as examples for inner surface vectors 1", 2", and 4", 5". Correspondingly, the lower surface vectors are combined into lower surface vector blocks, wherein lower surface vector block 24c is shown as an example for lower surface vector 3". In this case, the inner surface vector blocks and the lower surface vector blocks are processed alternately in a vector block sequence (not shown in detail, in particular here the numbering of the vectors only partially corresponds to the processing sequence). Lower surface region 14 (III) , 14 (IV) and inner surface area 15 (III) Together by Contour 20 (II) Border.

[0081] Figure 4 The connected area 18 is schematically shown (II) A top view of a second embodiment of the present invention, wherein only the portion closest to the contour 20 is shown. (II) The inner surface vectors 1", 8" and the lower surface vectors 6", 7", 9", 10", 11", 12" can be used to melt the connected area 18 in the contour movement defined by these vectors. (II) Profile 20 (II) , if necessary, in these vectors already in the connected area 18 (II) After being processed during the exposure, it is melted again.

[0082] Figure 5 Schematically shows the connected area 18 of the layer 7 to be treated (III) A top view of a third embodiment of the present invention. Figure 5 The rectangular connected area 18 shown (III) By inner surface area 15 (IV)and the first lower surface area 14 (V) and the second lower surface area 14 (VI) Composition, wherein the lower surface area 14 (V) , 14 (VI) Formed in the connected area 18 (III) At the opposite corner of the ground.

[0083] Some of them are Figure 5 The lower surface vectors marked as 3"', 4"', 7"' and 8"' in the corresponding lower surface area 14 (V) , 14 (VI) oriented parallel to each other and inclined to the connecting area 18 (III) Profile 20 (III) Orientation, wherein corresponding two lower surface vectors (for example, lower surface vectors 3"', 4"' or 7"', 8"') are combined into a lower surface vector block, which is exemplarily lower surface vector blocks 24d and 24e. Here, lower surface vectors 3"', 4"', 7"' and 8"' point to the connected area 18 (III) Profile 20 (III) , so that in the corresponding lower surface area 14 (V) , 14 (VI) During the exposure, the high energy beam 6 (see Figure 1 ) from the connected area 18 (III) The interior is guided to the contour 20 (III) , thus improving mechanical stability and achieving better heat dissipation during exposure of the lower surface vectors 3”’, 4”’, 7”’ and 8”’. Some of them are Figure 5 The inner surface vectors exemplarily labeled 1', 2', 5' and 6' are oriented antiparallel in the corresponding inner surface vector blocks 23e, 23f, which enables efficient guidance of the high energy beam 6 (see Figure 1 ).

[0084] In the processing sequence, for example, first the inner surface vectors 1'' and 2'' are processed in the inner surface vector block 23e for alternately exposing the inner surface region 15. (IV) and lower surface area 14 (V) Subsequently, the lower surface vectors 3", 4" in the lower surface vector block 24d are processed. Next, the inner surface vectors 5", 6" in the inner surface vector block 23f are processed. Thereafter, the lower surface vectors 7"', 8"' in the lower surface vector block 24e are processed.

[0085] Figure 6 The connected area 18 is schematically shown (III) A top view of a third embodiment, wherein the inner surface area 15 (IV) or lower surface area 14 (V) , 14(VI) In the middle, the lower surface vectors 9', 10' and 13', 14' and the inner surface vectors 11', 12' and 15', 16' are parallel and adjacent to the connected area 18. (III) Profile 20 (III) Extension. In the connected area 18 (III) In addition to Figure 5 These vectors are provided in addition to the vectors shown in . Figure 6 The lower surface vectors 9'', 10'' and 13'', 14'' and the inner surface vectors 11'', 12'' and 15'', 16'' are shown to direct the high energy beam 6 to perform contour movement and melt the connected area 18 (III) Profile 20 (III) This contour movement is usually used in processing Figure 5 The vectors schematically shown in FIG. 9 finally occur afterwards. The vectors 9'' to 16''' are processed here in the ascending order of their numbers.

[0086] Reference numerals list

[0087] 1 3D Printer

[0088] 2 Three-dimensional objects

[0089] 3 Lifting platform

[0090] 3a Substrate

[0091] 4. Manufacturing Room

[0092] 5a to 5c Powder layer

[0093] 6 High Energy Beam

[0094] 7 Layers to be processed

[0095] 8 Powder

[0096] 9 Planning boundaries in the layers to be processed

[0097] 10 Control Device

[0098] 11 Computer program products

[0099] 11a Computer program products

[0100] 12a to 12b Lower surface area of ​​layers 5b, 5c

[0101] 13a to 13b Inner surface area of ​​layers 5b, 5c

[0102] 14 (I) to 14 (VI) Lower surface area of ​​the layer to be treated

[0103] 15 (I) Up to 15 (VI) The inner surface area of ​​the layer to be treated

[0104] 16 Beam source

[0105] 17 Mirror

[0106] 18 (I) Up to 18 (III) Connected Areas

[0107] 19 Boundary

[0108] 20 (I) Up to 20 (III) contour

[0109] 21 Inner surface pattern

[0110] 22 Lower surface pattern

[0111] 23a to 23f Inner surface vector blocks

[0112] 24a to 24e Lower surface vector blocks

[0113] 25 Starting point of the first inner surface vector

[0114] 26 End point of the final inner surface vector

[0115] 27a, 27b Boundary surface segment

[0116] 28 End point of the last vector of the previous vector block

[0117] 29 Planning Device

[0118] 1' Inner surface vector

[0119] 2' Lower surface vector

[0120] 3' to 4' Inner Surface Vector

[0121] 5' Lower surface vector

[0122] 6' to 7' Inner Surface Vector

[0123] 8' Lower surface vector

[0124] 9' to 10' Inner Surface Vector

[0125] 11' Lower surface vector

[0126] 12' to 13' Inner Surface Vector

[0127] 14' Lower surface vector

[0128] 1” to 2” Inside Surface Vector

[0129] 3” lower surface vector

[0130] 4” to 5” inside surface vector

[0131] 6” Lower Surface Vector

[0132] 7” lower surface vector

[0133] 8” Inner Surface Vector

[0134] 9” to 12” Lower Surface Vector

[0135] 1”' to 2”' Inner surface vector

[0136] 3”' to 4”' Lower surface vector

[0137] 5”' to 6”' Inner Surface Vector

[0138] 7” to 10” Lower surface vector

[0139] 11”’ to 12”’ Inner Surface Vector

[0140] 13”' to 14”' Lower surface vector

[0141] 15”' to 16”' Inner Surface Vector

Claims

1. A method for planning the local solidification of layers (5a, 5b, 5c, 7) of powdered material using a high-energy beam (6) during the layer-by-layer production of a three-dimensional object (2), The method comprises the following steps: Step a): In the connected area (18) of the layer (7) in which the powdered material is to be solidified using the high-energy beam (I) Up to 18 (III) ), determine at least one inner surface area (15 (I) Up to 15 (VI) ) and at least one lower surface area (14 (I) to 14 (VI) ), Step b): For each inner surface area (15 (I) Up to 15 (VI) ) defines an inner surface pattern (21), wherein the inner surface pattern is formed in the inner surface area (15 (I) Up to 15 (VI) ) in which a plurality of inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') are determined for the high energy beam (6) and for each lower surface region (14 (I) to 14 (VI) ) defines a lower surface pattern (22), wherein the lower surface pattern is formed in the lower surface area (14 (I) to 14 (VI) ) defines a geometric extension of a plurality of lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"') for said high energy beam, in, The at least one inner surface area (15 (I) Up to 15 (VI) ) is defined independently of the at least one lower surface region (14 (I) to 14 (VI) ) is defined by one or more lower surface patterns (22); Step c): Define the processing sequence of all inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') and lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"'), It is characterized in that In step c), a plurality of inner surface vector blocks (23a, 23b, 23c, 23d) and a plurality of lower surface vector blocks (24a, 24b, 24c, 24d, 24e) are defined, wherein the corresponding inner surface vector blocks (23a, 23b, 23c, 23d, 23e, 23f) include one or more of the inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') to be processed continuously, and the corresponding lower surface vector blocks (24a to 24e) include one or more of the lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"') to be processed continuously, Among them, a vector block sequence of the inner surface vector blocks (23a to 23f) and the lower surface vector blocks (24a to 24e), which are collectively referred to as vector blocks hereinafter, is defined, and the inner surface vector blocks (23a to 23f) and the lower surface vector blocks (24a to 24e) are alternated in the vector block sequence.

2. The method according to claim 1, characterized in that In step c), the vector blocks (23a to 23f; 24a to 24e) are defined so that, at least primarily in corresponding two consecutive vector blocks (23a to 23f; 24a to 24e) in the vector block sequence, the corresponding end point (28) of the last vector (2') of the previous vector block (24a) in the layer (7) is spatially spaced apart from the starting point (25) of the first vector (3') of the subsequent vector block (23a).

3. The method according to claim 1 or 2, characterized in that: In step c), the vector blocks (23a to 23f; 24a to 24e) are defined so that, at least mainly in the corresponding two consecutive vector blocks (23a to 23f; 24a to 24e) in the vector block sequence, the extension direction of the last vector (2') of the previous vector block (24a) in the layer (7) is inclined to the extension direction of the first vector (3') of the subsequent vector block (24a).

4. The method according to any one of the preceding claims, characterized in that The inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') and the lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"') are defined so that The inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') extend obliquely to the lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"').

5. The method according to any one of the preceding claims, characterized in that At least in most of the inner surface blocks (23a to 23f) of the corresponding inner surface vector blocks (23a to 23f), - the inner surface vector block (23a to 23f) comprises at least a first inner surface vector (3', 6'; 1", 4", 1"', 5"') and a last inner surface vector (4', 7'; 2", 5", 2"', 6"'), - and the inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') included are selected in the following manner: the first inner surface vector (3', 6'; The starting point (25) of the inner surface vector (1", 4"; 1"', 5"') is located near the end point (26) of the final inner surface vector (4', 7'; 2", 5"; 2"', 6"'), In particular, the starting point (25) and the end point (26) have the following spacing, - the spacing is less than 1 / 4 of the length of the longest inner surface vector (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') of the inner surface vector block (23a to 23f), preferably less than 1 / 10 of the length of the longest inner surface vector (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') of the inner surface vector block (23a to 23f), and / or - the spacing is less than 25 times the shadow spacing in the inner surface vector blocks (23a to 23f), preferably less than 10 times the shadow spacing in the inner surface vector blocks (23a to 23f), and / or - The spacing is smaller than 2.5 mm, preferably smaller than 1.0 mm.

6. The method according to claim 5, characterized in that The starting point (25) of the first inner surface vector (3', 6'; 1", 4", 1"', 5"') is adjacent to the following boundary surface (19), which is located at the inner surface area (15) assigned to the inner surface vector block (23a to 23f). (I) Up to 15 (VI) ) and the adjacent lower surface area (14 (I) to 14 (VI) ), and the first inner surface vector (3', 6'; 1", 4"; 1"', 5"') are guided from the starting point (25) away from the adjacent lower surface area (14 (I) to 14 (VI) ), and the final inner surface vector (4', 7'; 2", 5"; 2"', 6"') are directed back to the adjacent lower surface area (14 (I) to 14 (VI) ).

7. The method according to any one of the preceding claims, characterized in that At least in most of the inner surface blocks (23a to 23f), the corresponding inner surface blocks (23a to 23f) are formed by an even number of inner surface vectors, in particular two, four or six inner surface vectors, from the inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') arranged side by side, and the inner surface vectors have alternating opposite extension directions, in particular, wherein the inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') extend parallel to each other.

8. The method according to any one of the preceding claims, characterized in that At least in some of the lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"'), the extension of the corresponding lower surface vector (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"') follows the associated lower surface area (14 (I) to 14 (VI) )'s adjacent contours (20 (I) Up to 20 (III) ), especially the outer contour (20 (I) Up to 20 (III) ) is an extension of .

9. The method according to any one of the preceding claims, characterized in that In step c), the inner surface vector blocks (23a to 23f) and the lower surface vector blocks (24a to 24e) are defined so that in the inner surface area (15 (I) Up to 15 (VI) ) and the lower surface area (14 (I) to 14 (VI) ), first processing all inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') at least partially located on or near the boundary surface segments (27a, 27b), and then processing all lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"') at least partially located on or near the boundary surface segments (27a, 27b).

10. The method according to claim 9, characterized in that Lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"') that are at least partially located closer to the boundary surface segment (27a, 27b) are processed before lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"') that are located farther away from the boundary surface segment (27a, 27b).

11. The method according to any one of the preceding claims, characterized in that Within the framework of step c), a waiting time is also defined between at least some consecutive vector blocks (23a to 23f; 24a to 24e) of the sequence of vector blocks, during which the processing with the high-energy beam (6) is suspended.

12. The method according to any one of the preceding claims, characterized in that At least some of the inner surface vector blocks (23a to 23f) that alternately follow the lower surface vector blocks (24a to 24e) in the vector block sequence are located in the inner surface area (15 (I) Up to 15 (VI) ) are arranged adjacent to each other, and / or At least some of the lower surface vector blocks (24a to 24e) that alternately follow the inner surface vector blocks (23a to 23f) in the vector block sequence are located in the associated lower surface area (14 (I) to 14 (VI) ) are arranged adjacent to each other.

13. A computer program product (11, 11a) which, when used on a control device (10) of a 3D printer (1) or on a planning device (29), executes the method according to claim 1.

14. A control device (10) or a planning device (29) of a 3D printer, which is programmed to carry out the method according to any one of claims 1 to 12.

15. A method for layer-by-layer production of a three-dimensional object (2), wherein: The powdery material (8) is solidified locally in layers (5a to 5c, 7) successively using a high-energy beam (6), wherein at least some of the layers (5a to 5c, 7) are respectively - (step α) planning of the local solidification in the layer (5a to 5c, 7) according to any one of claims 1 to 12, and -(Step β) performing the local solidification of the layer (5a to 5c, 7) according to the planning of step α, by treating the inner surface vectors (1', 3', 4', 6', 7', 9', 10', 12', 13'; 1", 2", 4", 5", 8"; 1"', 2"', 5"', 6"') and the lower surface vectors (2', 5', 8', 11', 14'; 3", 6", 7", 9", 10", 11", 12"; 3"', 4"', 7"', 8"') defined in step b) using the high-energy beam (6) in the order defined according to step c) of the planning for the layer (5a to 5c, 7).

16. A 3D printer (1) having a control device (10), wherein: The control device (10) is programmed to execute the method according to claim 15 on the 3D printer (1).

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