Methods, apparatuses, and devices for controlling an illumination beam

Abstract

This application describes a method for controlling an irradiation beam for irradiating a raw material powder layer in a layered manufacturing process for producing three-dimensional workpieces, wherein the method includes: depositing a raw material powder layer on top of a carrier and / or on top of a preceding material layer above the carrier using a layer deposition mechanism; controlling the irradiation beam to irradiate at least a portion of the raw material powder layer in the irradiation area when the distance between the irradiation area and the layer deposition mechanism is higher than a threshold distance, and wherein the threshold distance depends on (i) the moving speed of the layer deposition mechanism and (ii) the airflow velocity v above the raw material powder layer. g .

Description

Technical Field

[0001] The present invention generally relates to methods, apparatus and devices for controlling an irradiation beam in layer fabrication. Background Technology

[0002] In layered methods, a workpiece is produced layer by layer by creating a series of cured and interconnected workpiece layers. These processes can be distinguished by the type of raw material and / or the method of curing the raw material to produce the workpiece.

[0003] For example, powder bed melting is an additive layering process by which powder materials (particularly metallic and / or ceramic raw materials) can be processed into three-dimensional workpieces with complex shapes. To this end, layers of raw material powder are applied to a carrier and subjected, for example, to electron beam or laser radiation in a position-selective manner, according to the desired geometry of the workpiece to be produced. The radiation penetrating into the powder layer causes heating of the raw material powder particles, thus resulting in melting or sintering of the powder particles. Further layers of raw material powder are then sequentially applied to the radiation-treated layers on the carrier until the workpiece has the desired shape and size. Selective electron beam melting, selective laser melting, or laser sintering can be particularly used for producing prototypes, tools, replacement parts, or medical prostheses (e.g., dental or orthopedic prostheses) based on CAD data.

[0004] Throughout this disclosure, any description of selective laser melting is equally applicable to selective laser sintering, selective electron beam melting, stereolithography, MELATO, selective thermal sintering, or any other energy beam-based additive processing method. Therefore, any description of additive layer fabrication is applicable to one or more of selective laser melting, selective laser sintering, selective electron beam melting, stereolithography, MELATO, selective thermal sintering, and any other energy beam-based additive processing method.

[0005] A key parameter in layer-addition construction methods is the quality of the produced workpieces. Furthermore, production efficiency is crucial for maintaining, for example, the shortest possible production cycle time. Many strategies are known for accelerating the production of individual workpiece layers. However, when producing large workpieces, known methods do not always achieve the desired efficiency and / or quality. Summary of the Invention

[0006] Therefore, a particular objective of this invention is to improve the quality of three-dimensional workpieces produced using layered manufacturing processes. Another objective of this invention is to improve the efficiency of preparing three-dimensional workpieces using layered manufacturing processes while avoiding compromise in the quality of the produced three-dimensional workpieces.

[0007] Therefore, this paper describes a method for controlling an irradiation beam for irradiating a raw material powder layer in a layered manufacturing process for producing three-dimensional workpieces, wherein the method includes: depositing the raw material powder layer on top of a carrier and / or on top of a preceding material layer above the carrier using a layer deposition mechanism; controlling the irradiation beam to irradiate at least a portion of the raw material powder layer in the irradiation area when the distance between the irradiation area and the layer deposition mechanism is higher than a threshold distance, and wherein the threshold distance depends on (i) the moving speed of the layer deposition mechanism and (ii) the airflow velocity v above the raw material powder layer. g .

[0008] The inventors have realized that, particularly due to the movement of the layer deposition mechanism, the laminar airflow above the powder bed can be disturbed. Since it may be desirable to irradiate the raw powder layer while the layer deposition mechanism is moving, it may be necessary to define the irradiation area so that, especially during the movement of the layer deposition mechanism, the distance from the irradiation area to the various portions of the raw powder layer above which the laminar airflow is disturbed can be maintained. Therefore, the airflow in the irradiation area can be freed from disturbance by turbulence, which may be generated by the movement of the layer deposition mechanism. Thus, the quality of the workpiece to be produced is improved while efficiently fabricating the three-dimensional workpiece, because irradiation of the raw powder layer can begin while the layer deposition mechanism is still moving.

[0009] While the movement speed of the layer deposition apparatus (and, in some examples, the shape of the layer deposition apparatus, as will be further outlined below) may affect any turbulence that may occur during the movement of the layer deposition apparatus, the airflow velocity above the feed powder layer is also taken into account when controlling the irradiation beam. This is especially true of the exemplary embodiments of this disclosure, as any turbulence may be carried forward and away from the feed powder layer to be irradiated by the airflow. While the velocity of the airflow itself (particularly for airflow velocities above a threshold velocity) may cause turbulence depending on the shape and / or movement speed of the layer deposition apparatus, the greater the airflow velocity, the faster any turbulence can be carried away. Therefore, considering any operating conditions and parameters for producing three-dimensional workpieces, it may be necessary to find a balance between these considerations to optimize the airflow velocity.

[0010] As will be understood, the layer deposition apparatus may accelerate and decelerate during movement. Therefore, throughout this disclosure, any description of the movement speed of the layer deposition apparatus may refer to one or more of the following: the average movement speed of the layer deposition apparatus over a portion of the travel distance (particularly on the powder bed, i.e., on the feed powder layer, note that the layer deposition apparatus may move over one or more portions where no feed powder (layer) is deposited), the average movement speed of the layer deposition apparatus over the full travel distance of the layer deposition apparatus (wherein the full travel distance may be associated with one or more strokes of the layer deposition apparatus), and the movement speed of the layer deposition apparatus at a specific location (particularly on the powder bed, i.e., on the feed powder layer).

[0011] In some examples, the distance is maintained above a threshold distance as the layer deposition mechanism moves over the carrier and / or the previous material layer on top of the carrier. This ensures improved production efficiency of 3D workpieces while maintaining high quality.

[0012] In some examples, the airflow flows in a first direction parallel to the plane defined by the carrier, wherein the layer deposition mechanism is configured to move in a second direction perpendicular to or substantially perpendicular to the first direction, wherein the second direction is parallel to the plane defined by the carrier, and wherein the threshold distance is related to v in the second direction. ldm / v g Proportional, where v ldm This refers to the movement speed of the layer deposition mechanism in the second direction. This ensures high quality of the produced workpiece because the raw powder layer may not be irradiated in areas where turbulence might occur. In some examples, the threshold distance in the second direction is p. v ldm / v g+ o, where p is a factor greater than 0, and o is an offset greater than 0. In some examples, the offset can be between 10 mm and 50 mm (e.g., 10 mm, 15 mm, 20 mm, ..., 50 mm). In some examples, the offset can be variable, for example, between 10 mm and 50 mm, particularly in a stepwise manner (e.g., in steps of 1 mm or 0.1 mm) and / or continuously. The offset can ensure that the irradiated area is further away from areas where any turbulence may occur. The offset can be selected, for example, based on one or more machine / equipment parameters, such as the possible deflection speed of (one or more) scanner optics (e.g., the rotation speed of one or more scanner optics) and / or the system delay time of the control signals and / or the shape of the layer deposition mechanism. In some examples, p can represent a distance value in a first direction. In this case, the threshold distance on the gas inlet side of the feed powder layer can be lower than the threshold distance on the gas outlet side of the feed powder layer. The starting point of the distance value (p=0) can preferably be at the gas inlet, at the edge of the raw material powder layer, or at a point between the gas inlet and the edge of the raw material powder layer.

[0013] In some examples, the airflow velocity can be measured at one or more heights above the raw material powder layer. In some examples, the one or more heights can be between 5 mm and 50 mm above the raw material powder layer, allowing the airflow velocity to be measured at one or more heights between 5 mm and 50 mm. Therefore, in some examples, the airflow can be measured at two or more heights in a stepwise manner (e.g., in steps of 1 mm or 0.1 mm) and / or continuously (particularly between 5 mm and 50 mm). Additionally or alternatively, the airflow velocity can be measured at the height of the gas inlet.

[0014] In some examples, the airflow velocity can be measured at one or more points / locations within the build chamber, particularly at the gas inlet side edge / edge region and / or gas outlet side edge / edge region and / or above the powder bed (i.e., the raw material powder layer). Throughout this disclosure, any reference to “airflow velocity” may refer to a measurement at one of these points / locations, or the average of one or more (especially any combination of) measurements at two or more of these points / locations.

[0015] In some examples, the irradiation zone excludes areas on the feedstock powder layer that are closer to the layer deposition apparatus than a threshold distance when the layer deposition apparatus moves parallel to the carrier and / or the preceding material layer. Therefore, irradiation of the feedstock powder layer can be avoided in areas where any turbulence may still exist due to the movement of the layer deposition apparatus.

[0016] In some examples, the threshold distance also depends on the shape of the layer deposition apparatus. As will be explained, the shape of the layer deposition apparatus can induce any turbulence, especially when the layer deposition apparatus does not have an aerodynamic shape (or even when the layer deposition apparatus does have an aerodynamic shape). It should be understood that the higher the moving speed of the layer deposition apparatus, the more pronounced any turbulence may be. Furthermore, as mentioned above, particularly for airflow velocities above the threshold velocity, although the velocity of the airflow itself may induce turbulence depending on the shape and / or moving speed of the layer deposition apparatus, the higher the airflow velocity, the faster any turbulence can be carried away. Therefore, the aforementioned parameters can be considered when controlling the irradiation beam, especially when the layer deposition apparatus moves over the carrier and / or the preceding material layer on top of the carrier.

[0017] In some examples, the threshold distance also depends on the direction of gas flow. The direction of the airflow can affect the location and extent of turbulence. Therefore, considering the direction of the airflow enables the fabrication of higher quality 3D workpieces while ensuring that the 3D workpiece is produced while the layer deposition mechanism is still moving.

[0018] In some examples, the airflow velocity v above the raw material powder layer g This includes the gas flow velocity v in the volume within a threshold height from the layer deposition mechanism as the layer deposition mechanism moves parallel to the carrier and / or the preceding material layer. g As will be understood, this parameter allows for the determination of the extent to which any potential turbulence can (still) exist within a threshold distance to the layer deposition apparatus. This enables the irradiation of the feed powder layer to begin in the early stages while the layer deposition apparatus is still moving.

[0019] In some examples, the area is excluded from 1 / v. g Proportional. In other words, the higher the airflow velocity (e.g., at one or more predetermined heights above the raw material powder layer), the smaller the removal area. This is because at higher airflow velocities, any turbulence can be carried away by the airflow more quickly.

[0020] In some examples, the moving speed of the layer deposition mechanism can be adjusted between 0 m / s and 0.5 m / s, particularly continuously and / or in increments of 0.01 m / s. When the layer deposition mechanism moves, for example at a speed of 0.2 m / s, it allows the layer deposition mechanism to efficiently prepare the raw material powder layer, while any turbulence caused by the movement of the layer deposition mechanism can be kept at a reasonable level or a reasonable minimum.

[0021] In some examples, the layer deposition apparatus has a rectangular or generally rectangular shape when viewed from a cross-sectional angle perpendicular to a plane extending from the previous material layer on the carrier and / or the top of the carrier, and wherein the irradiation area excludes the region on the side of the layer deposition apparatus opposite to its direction of movement in the plane. This example allows for consideration of any potential turbulence that may form particularly or primarily behind the layer deposition apparatus, i.e., on the side of the layer deposition apparatus opposite to its direction of movement.

[0022] In some examples, the region has a triangular or approximately triangular shape, wherein the midline of the triangle is formed by the side of the layer deposition apparatus opposite to the direction of movement of the layer deposition apparatus in the plane. The inventors have realized that any potential turbulence is particularly likely to occur in such triangular or approximately triangular regions, making it possible to account for this phenomenon when controlling the irradiation beam, especially when determining which portions or parts of the feed powder layer are not irradiated (at least for a predetermined time period), said portions being within a threshold distance to the layer deposition apparatus. In some examples, the sides of the irradiation region are defined by the hypotenuse of a triangle, wherein the triangle is arranged between the layer deposition apparatus and the irradiation region.

[0023] In some examples, v g Between 1.0 m / s and 2.0 m / s, especially 1.5 m / s, and more specifically, where v g It is adjustable. This has been shown to be an airflow velocity that does not itself cause much turbulence as the airflow passes through the (moving) layer deposition mechanism, while the airflow can effectively eliminate any turbulence caused by the movement of the layer deposition mechanism.

[0024] In some examples, the irradiation of the feedstock powder layer is controlled to begin in the region where the layer deposition apparatus begins to form the feedstock powder layer. It is in this region that any potential turbulence may have already been (or initially) carried away by the airflow.

[0025] In some examples, irradiation of the raw material powder layer is controlled to begin at a position opposite or approximately opposite to the gas inlet of the airflow. This allows the raw material powder layer to be irradiated in the opposite direction to the airflow, ensuring that any fumes generated from irradiating the raw material powder layer do not affect subsequent irradiation of the raw material powder layer in uncured areas of that layer. In some examples, irradiation is controlled to continue against the airflow direction.

[0026] In some examples, the irradiation beam and / or the second irradiation beam are controlled to irradiate an area toward which the layer deposition apparatus moves in a plane extending from the previous material layer on the carrier and / or the top of the carrier. It can be assumed that no (or relatively little) turbulence occurs in this area. In some examples, the area toward which the layer deposition apparatus moves in the plane is changed during irradiation to be at a predetermined safe distance from the layer deposition apparatus, which makes it possible to ensure that no (or relatively little) turbulence occurs in the area to be irradiated.

[0027] This document further describes a computer program product including a program code portion that, when executed on one or more computing devices, performs methods as described herein in any of the exemplary embodiments. In some examples, the computer program product may be stored on a computer-readable recording medium.

[0028] This document further describes an apparatus for controlling an irradiation beam for irradiating a raw material powder layer in a layered manufacturing process for producing three-dimensional workpieces, wherein the apparatus includes: one or more processors; and a memory operatively coupled to the one or more processors, wherein the memory is configured to store a portion of program code that, when executed by the one or more processors, causes the apparatus to control the irradiation beam to irradiate at least a portion of the raw material powder layer in the irradiation area when the distance between the irradiation area and the layer deposition mechanism is greater than a threshold distance, the layer deposition mechanism being used to deposit the raw material powder layer on top of a carrier and / or on top of a preceding material layer on top of the carrier, wherein the threshold distance depends on (i) the moving speed of the layer deposition mechanism and (ii) the airflow velocity v above the raw material powder layer. g The apparatus can be specifically configured to perform the method according to any exemplary implementation throughout this disclosure.

[0029] This document also describes an apparatus for producing a three-dimensional workpiece via a layered manufacturing method, wherein the apparatus includes: a carrier configured to receive material for producing the three-dimensional workpiece; a material supply unit configured to supply material to the carrier and / or one or more prior material layers on top of the carrier; a layer deposition mechanism for forming the supplied material into a material layer on top of the carrier and / or one or more prior material layers on top of the carrier; a curing apparatus configured to cure the material supplied to the carrier and / or one or more prior material layers on top of the carrier to produce the three-dimensional workpiece; a gas supply unit configured to supply protective gas to an area of ​​the material layer to be cured by the curing apparatus; a processing chamber including the gas supply unit and the curing apparatus; and an apparatus according to any exemplary embodiment outlined throughout this disclosure. In some examples, the apparatus includes a computer program product according to any exemplary embodiment outlined throughout this disclosure. Attached Figure Description

[0030] These and other aspects of the invention will now be further described by way of example only with reference to the accompanying drawings, wherein the same reference numerals refer to the same parts, and wherein:

[0031] Figure 1 A schematic cross-sectional view of an apparatus for producing three-dimensional workpieces using a layered manufacturing process, according to some exemplary embodiments described herein, is shown.

[0032] Figure 2a and Figure 2b Cross-sectional side and top views of a layer deposition apparatus used during a layering manufacturing process according to some exemplary embodiments described herein are shown respectively;

[0033] Figure 3 Flowcharts of methods according to some exemplary embodiments described herein are shown;

[0034] Figure 4 Block diagrams of apparatuses according to some exemplary embodiments described herein are shown; and

[0035] Figure 5 A block diagram of a device according to some exemplary embodiments described herein is shown. Detailed Implementation

[0036] The inventors have realized that when the layer deposition mechanism moves, the laminar airflow above the powder bed may be disturbed.

[0037] If irradiation of the raw material powder layer is to begin while the deposition apparatus is still moving, it may be necessary to maintain a sufficient distance from the deposition apparatus to begin irradiation in an area where the airflow has already calmed. If the airflow in the area of ​​the build platform has returned to the desired state, irradiation can begin during the coating process.

[0038] Since turbulence is carried by the airflow, in some examples, the turbulent region is formed within an idealized triangle behind the layer deposition apparatus. As will be understood, among other things, the shape of the turbulent region in some examples is based on the shape of the layer deposition apparatus, which can take various shapes.

[0039] In this example, the extension of the triangle behind the layer deposition mechanism may be affected by the moving speed of the layer deposition mechanism (approximately 0.2 m / s in some examples), the shape of the layer deposition mechanism in some examples (due to turbulence generation), and the airflow velocity (approximately 1.5 m / s in some examples, such as at a height of 30 mm above the powder bed). In some examples, the typical width of the powder bed is between 150 mm and 1000 mm.

[0040] The distance from the stratification deposition apparatus where turbulence ceases (“calm distance”) can be set as a distance parallel to the stratification deposition apparatus. In some examples, this distance is calculated by the longest extension of the triangle (at the overrun edge of the airflow), while in others, it is calculated by an optional offset (an additional safety distance). Alternatively, there can be a boundary parallel to the hypotenuse (along the hypotenuse or in addition to the offset), meaning that in some examples, illumination on the upstream side of the airflow can begin earlier than illumination on the downstream side.

[0041] Irradiation can begin specifically at the edge of the powder bed, where the layer deposition apparatus has already begun to move across the powder bed, preferably also opposite the gas inlet, so that the irradiation process can proceed against the gas flow. Irradiation can begin once the layer deposition apparatus has covered at least the calm distance at the overshoot edge.

[0042] Furthermore, illumination “in front of” the layer deposition apparatus can occur simultaneously (using the same irradiation source and / or a second irradiation source). In some examples, only a small safety distance from the layer deposition apparatus can be maintained, such that calm (laminar) airflow can be assumed in this region in front of the layer deposition apparatus.

[0043] In particular, the present invention relates to methods, apparatus and equipment for producing three-dimensional workpieces using a layer-addition manufacturing process, and layer deposition mechanisms used therein.

[0044] The examples described herein enable increased productivity in layer-addition manufacturing processes, particularly in selective laser melting machines. Examples according to this disclosure allow irradiation to begin during coating (with powder material), or at least after the layer deposition apparatus has left the area of ​​the build platform, when the airflow in the build platform area has returned to the desired state, so that irradiation of the next layer can begin immediately without any loss of quality.

[0045] In some examples, the layer deposition mechanism, and its (mechanical) suspension or attachments, are designed such that the airflow guided above the build platform is minimally affected. In some examples, the suspension is designed as a mesh structure, particularly a honeycomb or layered structure, or as a single narrow mesh whose cross-sectional area in a plane perpendicular to the airflow direction is relatively small compared to the area in a plane defined by the outer contour of the suspension or the layer deposition mechanism. In some examples, the layer deposition mechanism itself is aerodynamically shaped, and in some examples, it may have gently tapered side surfaces to minimize turbulence as the airflow passes over them.

[0046] Figure 1 A schematic cross-sectional view of an apparatus 100 for producing a three-dimensional workpiece 102 using a layered manufacturing process is shown.

[0047] In this example, device 100 includes an irradiation unit 104 (e.g., a laser or particle beam generator) coupled to a deflection unit (scanner) 106, such that an irradiation beam 108 can be directed to a powder layer 110 or a powder bed. By controlling the irradiation beam 108 in this way, workpiece 102 can be suitably produced, wherein the powder material 111 is not cured by the irradiation beam 108 in certain areas.

[0048] In this example, the device includes a carrier 112 on which a three-dimensional workpiece 102 is produced. The carrier 112 can be moved vertically within a processing chamber 116 by a lifting mechanism 114, as shown in this example.

[0049] In this example, device 100 includes a generally pyramidal or trapezoidal layer deposition mechanism 118. In all examples of this disclosure, the layer deposition mechanism may also have only one inclined side surface (e.g., a side surface facing a gas inlet or gas outlet), while the other side surfaces are perpendicular to the carrier plane.

[0050] In this example, the layer deposition mechanism 118 of the apparatus 100 has a lower side 119a and an opposing side 119b parallel to the lower side, on which powder material is applied to a carrier and / or a powder bed having a larger area than the side 119b. A powder spreading device 118b (i.e., a spreading element or doctor blade element, such as a coating machine lip, brush, roller, or pusher) is attached to the lower side of the layer deposition mechanism 118.

[0051] In this example, the layer deposition mechanism 118 has gentle, tapered side surfaces 119c and 119d. In particular, the transitions between side surfaces 119c and 119b, and between side surface 119b and 119d, are convex, allowing airflow to be guided across the layer deposition mechanism 118 without inducing turbulence (or only very minor turbulence) in the airflow.

[0052] In this example, the layer deposition mechanism 118 is coupled to layer deposition mechanism suspensions 120a and 120b in two regions. In some examples, the layer deposition mechanism is coupled to the layer deposition mechanism suspension in only one region. In this example, the device 100 also includes guide rails and / or actuators 122a and 122b, through which the layer deposition mechanism 118, together with the layer deposition mechanism suspensions 120a and 120b, can move on the carrier 112, or, in this example, on the powder layer 110.

[0053] In this example, the device 100 also includes a gas inlet 124 and a gas outlet 126, thereby generating an airflow 125 within the device 100. This airflow 125 forms an airflow, particularly a laminar airflow, over the carrier 112 or the uppermost powder layer 110 when the layer deposition mechanism 118 is not located above the carrier 112. The axis 128 between the gas inlet 124 and the gas outlet 126 is shown as a dashed line. In this example, the device also includes a gas inlet 130 to generate a second airflow 132 between the gas inlet 130 and the gas outlet 126.

[0054] One or more surfaces 119c of the layer deposition mechanism 118 opposite the gas inlet nozzle (i.e., gas inlet 124) serve as gas conduction surfaces and are therefore preferably formed at an angle of 0° to 90° (approximately 45° in this example) to the axis 128.

[0055] The layered deposition mechanism suspension 120a on the surface 119c side and / or the other side 119d is at least partially topped as a gas-flowable structure, particularly a grid structure and / or a layered structure.

[0056] In this example, the gas-flowable structure of the layer deposition mechanism suspensions 120a and 120b has at least a partial flow-direction cross section, particularly an elliptical or teardrop-shaped cross section.

[0057] In this example, the surface 119d of the layer deposition mechanism 118 opposite the gas outlet (i.e., gas outlet 126) also serves as a gas guiding surface, and preferably forms an angle of 0° to 90° (approximately 45° in this example) with respect to the axis 128. Specifically, this angle can be the same as the angle of surface 119c relative to the axis 128. Alternatively, the layer deposition mechanism 118 can continue along the direction of the outlet, particularly until it reaches the wall containing the outlet (i.e., gas outlet 126), and at least partially cover the gas outlet 126.

[0058] In this example, the transition from side 119c to the upper surface / side 119b of the layer deposition mechanism 118 and / or the transition from side 119d to the upper surface / side 119b of the layer deposition mechanism 118 are convex to allow the airflow to contact the surface and avoid turbulence.

[0059] In some examples, the front and / or rear portions of the layer deposition mechanism 118 are also angled. Alternatively, the front and / or rear portions of the layer deposition mechanism 118 may be configured to be angled during movement over the powder layer 110 and may be moved from one or both parking positions (on opposite sides of the powder layer) to an upright position just abutting the wall of the processing chamber. In some examples, the mechanism is coupled to an opening in the powder chute.

[0060] The guide sections of the suspensions 120a and 120b of the layer deposition mechanism can be designed to deflect the airflow differently depending on the direction of movement. For this purpose, these sections can be specifically designed to be adjustable. Depending on the direction of movement, the guide sections can be aligned in the direction of the resulting relative flow to minimize the impact on the airflow.

[0061] Figure 2a A cross-sectional side view of a layer deposition apparatus 118 used during a layering manufacturing process according to some exemplary embodiments described herein is shown.

[0062] As can be seen, when the layer deposition mechanism 118 moves along the moving direction 204, a distance 202 (referred to as the "calm distance" as described above) can be maintained between the irradiation area 203 where the irradiation beam 108 solidifies the raw material powder and the layer deposition mechanism 118. Therefore, it can be ensured that the irradiation beam 108 does not irradiate the raw material powder too close to the layer deposition mechanism 118 where turbulence may occur. In this example, the distance 202 is determined based on the shape of the layer deposition mechanism 118, the moving speed of the layer deposition mechanism 118, and the velocity of the airflow on the raw material powder layer.

[0063] Figure 2b A top view is shown of a layer deposition apparatus 118 used during a layering manufacturing process according to some exemplary embodiments described herein.

[0064] The airflow 212 above the raw material powder layer and the layer deposition mechanism 118 is indicated by arrows.

[0065] As can be seen in this example, a (hypothetical) triangle 214 is formed between the irradiation area 203 and the layer deposition mechanism 118, whereby turbulence may occur, causing this area to be excluded from the irradiation of the irradiation beam 108. This area changes as the layer deposition mechanism 118 moves.

[0066] In this example, an offset is provided between triangle 214 and illumination area 203. Figure 2b (The dashed line in the diagram) This allows for an additional safety distance between the layer deposition apparatus 118 and the irradiation area 203 to ensure that no turbulence occurs in the irradiation area 203 (or only turbulence below a threshold occurs). In an example where the distance 202 is defined parallel to the layer deposition apparatus 118, the offset can be defined as an offset 216 parallel to the edge of the layer deposition apparatus 118, which is opposite to the direction of movement of the layer deposition apparatus 118. In an example where the edge of the irradiation area 203 is defined by the hypotenuse of triangle 214, the offset can be defined as an offset 218 aligned parallel to the hypotenuse of triangle 214. In this example, offset 216 and / or offset 218 are between 10 mm and 50 mm. Offset 216 and / or offset 218 can be variable (as described above, for example, in a stepwise manner (in steps of 1 mm or 0.1 mm) and / or continuously variable).

[0067] In this example, irradiation begins at the edge of the powder bed, where the layer deposition mechanism has already begun its movement (and preferably, additionally, opposite the gas inlet, thus providing irradiation against the gas flow). In this example, irradiation can begin once the layer deposition mechanism has covered at least a distance 202 at the overshoot edge.

[0068] Figure 3 A flowchart of a method 300 according to some exemplary embodiments described herein is shown.

[0069] In this example, method 300 includes step S302, depositing a raw material powder layer on top of a carrier and / or on top of a preceding material layer using a layer deposition apparatus. In step S304, method 300 includes controlling an irradiation beam to irradiate at least a portion of the raw material powder layer in the irradiation area when the distance between the irradiation area and the layer deposition apparatus is greater than a threshold distance, wherein the threshold distance depends on (i) the moving speed of the layer deposition apparatus and (ii) the airflow velocity v above the raw material powder layer. g .

[0070] Figure 4A block diagram is shown of an apparatus 400 for controlling an irradiation beam for irradiating a raw material powder layer in a layered manufacturing process for producing a three-dimensional workpiece, according to some example embodiments described herein.

[0071] In this example, the device 400 includes: one or more processors 402; and a memory 404 operatively coupled to the one or more processors, wherein the memory is configured to store a portion of program code that, when executed by the one or more processors, causes the device to control an irradiation beam to irradiate at least a portion of a raw material powder layer in the irradiation area when the distance between the irradiation area and the layer deposition mechanism is greater than a threshold distance, the layer deposition mechanism being used to deposit the raw material powder layer on top of a carrier and / or on top of a preceding material layer on top of the carrier, wherein the threshold distance depends on (i) the moving speed of the layer deposition mechanism and (ii) the airflow velocity v above the raw material powder layer. g .

[0072] Figure 5 A block diagram of an apparatus 500 for producing three-dimensional workpieces via a layered manufacturing method according to some exemplary embodiments described herein is shown.

[0073] In this example, apparatus 500 includes a carrier 112 configured to receive material for producing a three-dimensional workpiece; a material supply unit 502 configured to supply material to the carrier and / or one or more prior material layers on top of the carrier; a layer deposition mechanism 118 for forming the supplied material into a material layer on top of the carrier and / or one or more prior material layers on top of the carrier; a curing device 104 configured to cure the material supplied to the carrier and / or one or more prior material layers on top of the carrier to produce a three-dimensional workpiece; a gas supply unit 504 configured to supply protective gas to the area of ​​the material layer to be cured by the curing device; a processing chamber 506 including the gas supply unit and the curing device; and examples according to the description herein (particularly). Figure 4 The device 400. The carrier 112, the material supply unit 502 and the layer deposition mechanism 118 can also be arranged in the processing chamber 506.

[0074] Undoubtedly, those skilled in the art will conceive of many other effective alternatives. It should be understood that the invention is not limited to the described embodiments and exemplary implementations, and includes modifications that are obvious to those skilled in the art and fall within the scope of the appended claims.

Claims

1. A method for controlling an irradiation beam for irradiating a raw material powder layer in a layered manufacturing process for producing a three-dimensional workpiece, wherein, The method includes: The raw material powder layer is deposited on top of the carrier and / or on top of the preceding material layer using a layer deposition mechanism; and When the distance between the irradiation area and the layer deposition mechanism is higher than a threshold distance, the irradiation beam is controlled to irradiate at least a portion of the raw material powder layer in the irradiation area, wherein the threshold distance depends on... (i) the moving speed of the layer deposition mechanism, and (ii) The airflow velocity v above the raw material powder layer g , The airflow flows in a first direction parallel to the plane defined by the carrier, and the layer deposition mechanism is configured to move in a second direction perpendicular to the first direction, wherein the second direction is parallel to the plane defined by the carrier. The irradiation area excludes the following regions on the raw material powder layer: when the layer deposition mechanism moves parallel to the carrier and / or the preceding material layer, these regions are closer to the layer deposition mechanism than a threshold distance, wherein the excluded area is proportional to 1 / v. g Proportional.

2. The method according to claim 1, wherein, As the layer deposition mechanism moves past the carrier and / or the preceding material layer on top of the carrier, the distance remains above the threshold distance.

3. The method according to claim 1, wherein, The threshold distance and v in the second direction ldm / v g Proportional, where v ldm It is the moving speed of the layer deposition mechanism in the second direction.

4. The method according to claim 3, wherein, The threshold distance in the second direction is p v ldm / v g + o, where p is a factor greater than 0, and o is an offset greater than 0.

5. The method according to claim 1, wherein, The threshold distance also depends on the shape of the layer deposition mechanism.

6. The method according to claim 1, wherein, The threshold distance also depends on the gas flow direction of the airflow.

7. The method according to claim 1, wherein, The airflow velocity v above the raw material powder layer g This includes the airflow velocity v in the volume within a threshold height from the layer deposition mechanism when the layer deposition mechanism moves parallel to the carrier and / or the preceding material layer. g .

8. The method according to claim 1, wherein, The moving speed of the layer deposition mechanism can be adjusted between 0 m / s and 0.5 m / s.

9. The method according to claim 1, wherein, Viewed from a cross-sectional angle perpendicular to the plane extending from the previous material layer on the top of the carrier, the layer deposition apparatus has a rectangular or substantially rectangular shape, wherein the irradiation area is excluded on the side of the layer deposition apparatus opposite to the direction of movement of the layer deposition apparatus in the plane.

10. The method according to claim 9, wherein, The region has a triangular or approximately triangular shape, wherein the midline of the triangle is formed by the side of the layer deposition mechanism that is opposite to the direction of movement of the layer deposition mechanism in the plane.

11. The method according to claim 10, wherein, The side of the irradiation area is defined by the hypotenuse of the triangle, wherein the triangle is arranged between the layer deposition apparatus and the irradiation area.

12. The method according to claim 1, wherein, v g Between 1.0 m / s and 2.0 m / s.

13. The method according to claim 1, wherein, The irradiation of the raw material powder layer is controlled to begin in the region where the raw material powder layer begins to form in the layer deposition apparatus.

14. The method according to claim 1, wherein, The irradiation of the raw material powder layer is controlled to begin at a position opposite or approximately opposite to the gas inlet of the airflow.

15. The method according to claim 14, wherein, The irradiation is controlled to continue in the opposite direction to the airflow.

16. The method according to claim 1, wherein, The irradiation beam and / or the second irradiation beam are controlled to irradiate an area in which the layer deposition mechanism moves toward the area in a plane extending from the previous material layer on the carrier and / or the top of the carrier.

17. The method according to claim 16, wherein, The area that the layer deposition mechanism moves toward in the plane is changed to a predetermined safe distance from the layer deposition mechanism during irradiation.

18. The method of claim 8, wherein, The moving speed of the layer deposition mechanism can be continuously adjusted between 0 m / s and 0.5 m / s.

19. The method of claim 8, wherein, The moving speed of the layer deposition mechanism can be adjusted in increments of 0.01 m / s between 0 m / s and 0.5 m / s.

20. The method according to claim 12, wherein, v g It is adjustable.

21. The method of claim 12, wherein, v g It is 1.5 m / s.

22. A computer program product comprising a program code portion configured to perform the method according to claim 1 when the computer program product is executed on one or more computing devices.

23. The computer program product according to claim 22, wherein, The computer program product is stored on a computer-readable recording medium.

24. An apparatus for controlling an irradiation beam for irradiating a layer of raw material powder in a layered manufacturing process for producing a three-dimensional workpiece, wherein, The device includes: One or more processors, and A memory operatively coupled to the one or more processors, wherein the memory is configured to store program code portions that, when executed by the one or more processors, cause the apparatus to control the irradiation beam to irradiate at least a portion of the raw material powder layer in the irradiation region when the distance between the irradiation region and the layer deposition mechanism is greater than a threshold distance, the layer deposition mechanism being used to deposit the raw material powder layer on top of a carrier and / or on top of a preceding material layer above the carrier, wherein the threshold distance depends on (i) the moving speed of the layer deposition mechanism and (ii) the airflow velocity v above the raw material powder layer. g , The airflow flows in a first direction parallel to the plane defined by the carrier, and the layer deposition mechanism is configured to move in a second direction perpendicular to the first direction, wherein the second direction is parallel to the plane defined by the carrier. The irradiation area excludes the following regions on the raw material powder layer: when the layer deposition mechanism moves parallel to the carrier and / or the preceding material layer, these regions are closer to the layer deposition mechanism than a threshold distance, wherein the excluded area is proportional to 1 / v. g Proportional.

25. The apparatus according to claim 24, wherein, The apparatus is configured to perform a method for controlling an irradiation beam for irradiating a raw material powder layer in a layered manufacturing process for producing a three-dimensional workpiece, wherein the method includes: The raw material powder layer is deposited on top of the carrier and / or on top of the preceding material layer using a layer deposition mechanism; and When the distance between the irradiation area and the layer deposition mechanism is higher than a threshold distance, the irradiation beam is controlled to irradiate at least a portion of the raw material powder layer in the irradiation area, wherein the threshold distance depends on... (i) the moving speed of the layer deposition mechanism, and (ii) The airflow velocity v above the raw material powder layer g , The airflow flows in a first direction parallel to the plane defined by the carrier, and the layer deposition mechanism is configured to move in a second direction perpendicular to the first direction, wherein the second direction is parallel to the plane defined by the carrier.

26. An apparatus for producing a three-dimensional workpiece via a layered manufacturing method, wherein, The device includes: A carrier configured to receive material for producing the three-dimensional workpiece; A material supply unit configured to supply material to the carrier and / or one or more prior material layers on top of the carrier; A layer deposition apparatus for forming supplied material as a material layer on top of the carrier and / or one or more previous material layers on top of the carrier; A curing apparatus configured to cure material supplied to the carrier and / or one or more prior material layers on top of the carrier to produce the three-dimensional workpiece; A gas supply unit configured to supply protective gas to the area of ​​the material layer to be cured by the curing device; The processing chamber includes the gas supply unit and the curing device; and The apparatus according to claim 24.

27. The device according to claim 26, wherein, The device further includes a computer program product comprising a program code portion configured to, when executed on one or more computing devices, perform a method for controlling an irradiation beam for irradiating a raw material powder layer in an additive manufacturing process for producing a three-dimensional workpiece, wherein the method includes: The raw material powder layer is deposited on top of the carrier and / or on top of the preceding material layer using a layer deposition mechanism; and When the distance between the irradiation area and the layer deposition mechanism is higher than a threshold distance, the irradiation beam is controlled to irradiate at least a portion of the raw material powder layer in the irradiation area, wherein the threshold distance depends on... (i) the moving speed of the layer deposition mechanism, and (ii) The airflow velocity v above the raw material powder layer g , The airflow flows in a first direction parallel to the plane defined by the carrier, and the layer deposition mechanism is configured to move in a second direction perpendicular to the first direction, wherein the second direction is parallel to the plane defined by the carrier.

Images