EP4072754A1 - Inversion de hachurage à transfert de capillaire (keyhole) - Google Patents

Inversion de hachurage à transfert de capillaire (keyhole)

Info

Publication number
EP4072754A1
EP4072754A1 EP20811561.8A EP20811561A EP4072754A1 EP 4072754 A1 EP4072754 A1 EP 4072754A1 EP 20811561 A EP20811561 A EP 20811561A EP 4072754 A1 EP4072754 A1 EP 4072754A1
Authority
EP
European Patent Office
Prior art keywords
trajectory
layer
end point
building material
additive manufacturing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP20811561.8A
Other languages
German (de)
English (en)
Inventor
Peter HOLFELDER
Jochen Philippi
Christoph Seyfert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EOS GmbH
Original Assignee
EOS GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by EOS GmbH filed Critical EOS GmbH
Publication of EP4072754A1 publication Critical patent/EP4072754A1/fr
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/20—Direct sintering or melting
    • B22F10/28—Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/30—Auxiliary operations or equipment
    • B29C64/386—Data acquisition or data processing for additive manufacturing
    • B29C64/393—Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/30—Process control
    • B22F10/36—Process control of energy beam parameters
    • B22F10/366—Scanning parameters, e.g. hatch distance or scanning strategy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/80—Data acquisition or data processing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/10—Processes of additive manufacturing
    • B29C64/141—Processes of additive manufacturing using only solid materials
    • B29C64/153—Processes of additive manufacturing using only solid materials using layers of powder being selectively joined, e.g. by selective laser sintering or melting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y10/00—Processes of additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y30/00—Apparatus for additive manufacturing; Details thereof or accessories therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y50/00—Data acquisition or data processing for additive manufacturing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • the present invention relates to a device and a method for providing control data for an additive manufacturing device, a correspondingly adapted additive manufacturing method, a corresponding device for controlling energy input devices of an additive manufacturing device, a correspondingly adapted additive manufacturing device and a correspondingly adapted computer program.
  • Additive manufacturing devices and associated processes are generally characterized in that objects are manufactured in them layer by layer by solidifying a shapeless building material.
  • the solidification can be brought about, for example, by supplying thermal energy to the building material by irradiating it with electromagnetic radiation or particle radiation (e.g. laser sintering (SLS or DMLS) or laser melting or electron beam melting).
  • electromagnetic radiation or particle radiation e.g. laser sintering (SLS or DMLS) or laser melting or electron beam melting.
  • SLS or DMLS laser sintering
  • laser melting laser melting
  • a laser beam is moved over those points of a layer of the building material which correspond to the object cross-section of the object to be produced in this layer, so that the building material is solidified at these points.
  • FIG. 10 shows the usual procedure in the additive production of objects by irradiating construction material with electromagnetic radiation or particle radiation (e.g. laser sintering (SLS or DMLS)) or laser melting or Electron beam melting).
  • electromagnetic radiation or particle radiation e.g. laser sintering (SLS or DMLS)
  • laser melting or Electron beam melting e.g. laser sintering (SLS or DMLS)
  • an object cross-section 50 is subdivided into an inner area or core area 52 and a contour area 51, the contour area 51 generally being assigned different parameters for the energy input into the building material than the inner area 52
  • the laser beam is scanned in such a way that the laser beam is moved along the course of the contour.
  • the inner area 52 is usually solidified in such a way that the inner area 52 is divided into partial areas 53, which usually have an approximately rectangular or square shape and are therefore also referred to as "strips" or "squares".
  • the inner area 52 is then scanned section by section with the laser beam.
  • each sub-area 53 the laser beam is moved along parallel paths (hatch lines) 54 over the building material, which results in a hatching-like movement pattern when each sub-area 53 is scanned with the laser beam.
  • This process is also known as "hatching" in technical jargon.
  • FIG. 10 the direction of movement of the laser beam is illustrated by arrows. It can be seen that the directions of movement for adjacent hatch lines 54 are opposite to one another.
  • FIG. 11 illustrates how such a movement pattern of the laser beam can be achieved, only two hatch lines 64, 65 of the area 53 being shown.
  • the starting point and the end point are denoted by the reference symbols 64A and 64E, respectively.
  • the starting point and the end point are denoted by the reference numerals 65A and 65E, respectively.
  • the laser beam enters the area 53 at the top left in FIG. 11 and scans the building material in the area 53 along the upper hatch line 64.
  • the laser beam is switched off and the direction of movement of the laser beam is changed within the reversing area 55 without radiation being supplied to the building material, so that the laser beam then moves along the second top hatch line 65 in the opposite direction via the construction material in sub-area 53 can be moved. Following this movement pattern, the entire partial area 53 is then scanned, as is illustrated in FIG. 11.
  • the object of the present invention is therefore to provide a method and a device by means of which the component homogeneity of objects produced by an additive manufacturing method can be improved.
  • a computer-aided method for providing control data for an additive manufacturing device for manufacturing a three-dimensional object, the object being manufactured by means of the additive manufacturing device by applying a building material layer on layer and solidifying the building material in a building plane by supplying radiation energy to locations in each layer corresponding to the cross section of the object in assigned to this layer by scanning these points with at least one beam according to a set of energy input parameter values along a plurality of trajectories, has: a first step of accessing computer-based model data of at least one section of the object to be produced, a second step of generating at least one Data model of an area of a building material layer to be selectively solidified for the production of the at least one object section, the data model specifying a scanning of locations of the area to be selectively solidified along a first trajectory and a second trajectory essentially parallel thereto with at least one beam, the motion vectors of the beam bundles in the construction plane have opposite directional components when scanning along the two trajectories, it being specified that a starting point
  • Additive manufacturing devices and methods to which the present invention relates are in particular those in which energy is selectively supplied as electromagnetic radiation or particle radiation to a layer of a shapeless building material.
  • the working level (also referred to as the construction level) is a level in which the top of the layer to which the energy is supplied lies.
  • the energy input device can have a laser or an electron beam source, for example.
  • the radiation supplied to the building material heats it up and thereby causes a sintering or melting process.
  • the present invention encompasses laser sintering, laser melting and electron beam melting devices and the associated methods.
  • An application of the invention in connection with additive manufacturing processes and devices in which a metallic or at least metal-containing building material is used, for example a metal powder or metal alloy powder.
  • the control data set (often also referred to as a control command set) is a sequence of instructions to apply layers of the building material one after the other and to scan areas of the respective layers that correspond to the cross-section of an object to be manufactured with radiation in order to solidify the building material.
  • a control data set is based on a computer-based model of the object or objects to be produced, preferably a CAD model.
  • the control data set defines the points at which the build-up material is to be solidified by the supply of radiation, and optionally a thickness of the layer.
  • a control data record often also contains manufacturing device-specific information, for example with regard to the position and orientation of the objects in the additive manufacturing device.
  • the control data record contains all of the data required to control the energy input device, which means, inter alia. the radiation power in the beam and / or the speed of movement of the beam can be determined via the construction material and / or an irradiation pattern.
  • beam is used here instead of “beam” to express that the diameter of the beam does not necessarily have to be very small, especially if the radiation strikes the building material at an angle or if radiation is used that strikes it aware of the construction material should cover a larger area (for example if a line imagesetter is used).
  • the control data set can be viewed as the entirety of all control data specified for controlling the manufacturing process in an additive manufacturing device.
  • the control data relating to an individual shift is usually referred to as a shift data record.
  • a slice data set contains a data model of locations of an object cross-section to be solidified during the manufacturing process.
  • Such a data model is obtained from computer-based model data of the object to be produced, in particular a CAD model of the object to be produced, in that the CAD model is broken down into layers (referred to as slicing in technical jargon).
  • a two-dimensional representation of the object cross-section to be solidified in a layer by means of one or more bundles of rays from the computer-based model data of the object in some other way.
  • the layer data set points corresponding to an object cross-section, which are to be solidified in the associated building material layer, are specified.
  • further information regarding the production of the object cross-section can be included, in particular the chronological order in which points corresponding to an object cross-section are to be solidified, i.e. a scan line or a trajectory along which the beam is to be moved, or z.
  • B the layer thickness or irradiation parameter values, such as the diameter or the travel speed of a beam striking the building material, etc.
  • the energy input devices to be controlled often have an inertia that can lead to the actual movement of a beam across the building plane deviating from a trajectory specified in a data model (for example at corners, i.e. places where an abrupt change in direction takes place ). It is known to the person skilled in the art (see e.g. DE 102018205689 A1) how these deviations can be taken into account by making appropriate changes to the data model when determining the control data. In the present application, these possibly necessary changes to the data model are therefore not discussed further and it is assumed that the movement of a beam actually takes place as it is specified in the control data. Any necessary changes to the data model can be made to the control data provided according to the invention at any time by a person skilled in the art.
  • the computer-based model data can be, for example, a model of the object section to be produced, which z. B. is available as a CAD model or converted into the STL format, and does not yet contain any information about the breakdown into layers for a layered Fier ein. It is also conceivable for the model data to be available in a GML (Generative Modeling Language) description.
  • the computer-based model data can be a number of layer data sets, each of which has a data model of a region of a building material layer to be selectively solidified during the setting, which corresponds to a cross section of the object section.
  • the model data can be accessed in such a way that the model data are read out from a memory or received via a network.
  • the model data of the entire object section do not necessarily have to be read in at once. It is also possible that there is a greater time interval between the access processes to parts of the model data, for example parts of the model data as required during a setting process of the object section from a memory (which is also accessed, for example, by the additive setting device can be read in) or via a network and then a generated data model during of the manufacturing process is integrated into the control data record.
  • An additive manufacturing device can therefore itself modify the control data set for its activation on the basis of the method according to the invention.
  • the generation of at least one data model in the second step can consist in modifying a data model of a building material layer that is already present in the model data. Otherwise, a data model of a building material layer (or a part thereof) can be generated for the first time in the second step.
  • those scan lines (sections) can be viewed as consolidation paths in which, when the building material is scanned, the at least one beam actually consolidates it and not merely heats it.
  • a consolidation sheet can e.g. B. be a straight stretch of a certain width, along which the building material is solidified by the scanning.
  • the area to be selectively consolidated in which the first and the second trajectory are specified, can for example comprise one or more of the partial areas 53 in FIG.
  • the building material solidifies along a trajectory, as a result of the energy supplied by the beam when the building material is scanned, the latter is partially or completely melted, as a result of which the constituents of the building material (for example powder grains) combine with one another. After it has cooled down, the build-up material is then present as a solid body.
  • the terms sintering and melting are used synonymously in the present application.
  • the present invention can be used in additive manufacturing processes in which, when a beam is directed onto the building material, the building material is completely melted, in particular by means of a deep welding process.
  • the length of a consolidation path corresponds, for example, to the width of a (often strip-shaped or rectangular) sub-region of a cross-section of the object to be produced that is to be consolidated. If an object cross-section is solidified by means of a beam in the form of a hatched pattern, such solidification paths are also referred to as "hatch lines".
  • the length of a consolidation path can also correspond to the dimensions of the object cross-section in the direction of the course of the hatch lines, with the width possibly also being approximately the same a contour line framing the cross-section must be subtracted from this dimension.
  • the length of a consolidation path can also correspond to the distance between the edge of a (often rectangular or square) sub-area of an object cross-section to be consolidated and the edge of the object cross-section or the contour line.
  • the minimum width of the resulting consolidation path is defined as the extent of the beam perpendicular to the direction of movement of the beam, i.e. the beam width.
  • the present invention relates to a first and a second trajectory which are adjacent to one another, which means that a distance of the second trajectory to the first trajectory is a maximum of five times the beam width of the beam when the beam is moving along the first trajectory, preferably a maximum three times the beam width, more preferably corresponds to a maximum of the beam width.
  • the distance is determined perpendicular to the direction of movement of the beam on the first trajectory. Sections of the first trajectory in which a perpendicular to the direction of movement of the beam along the first solidification path has no point of intersection with the second trajectory are disregarded for the determination of the maximum distance.
  • the first and the second trajectory preferably run essentially parallel to one another, for example to at least 80%, preferably at least 95%, of the length of the shorter of the two.
  • first and second trajectories may run next to one another at an angle of less than 30 °, preferably less than 20 °, even more preferably less than 10 °, most preferably less than 5 ° to one another.
  • running side by side it is meant that on at least 90%, preferably at least 95%, of the length of the shorter of the two trajectories, a perpendicular on the shorter trajectory intersects the other trajectory.
  • the present invention is directed in particular to hatch lines as first and second trajectories which are used for the surface consolidation of areas. If the invention relates to the consolidation of strip-shaped or square partial areas is used, the first and second trajectories are hatch lines when scanning such partial areas, then the first and second trajectories have the same length. Otherwise, especially if the areas to be consolidated are not rectangular or the trajectories do not run perpendicular to the edges of a sub-area, the hatch lines can also have different lengths.
  • the start and end points of a consolidation path in the building plane are assigned to the start or end point of a trajectory. While a point on a trajectory in a data model has no extension per se, this point in the building plane corresponds to an area within which the building material is melted by the action of the beam with a diameter other than zero.
  • the expansion of the resulting melt pool influences the width of the solidification path, i.e. the area that is later hardened.
  • the expansion of the melt pool depends on the expansion of the beam (its diameter) when it hits the build-up material.
  • locations of the building material to be irradiated are encoded in the control data for controlling the at least one beam as points within a coordinate system, which are two-dimensional (based on a layer) and / or three-dimensional (based on a structural volume of the manufacturing device, i.e. a plurality of layers). can be defined. Information about a respective expansion of the beam when it hits the building level can then be linked to these points.
  • a starting point and / or an end point of a consolidation path can therefore definitely be present as mathematical points and the consolidation path can be present as a line (trajectory).
  • the direction of scanning along a trajectory or consolidation along a consolidation path generally runs from the starting point to the end point, with the starting point as the first place of a trajectory scanned in time and the end point as the last place of a trajectory scanned in time.
  • any pivoting movements of the beam around the start or end point are disregarded. If the distance between the consolidation paths is sufficiently small, then the second trajectory does not have to lie directly next to the first trajectory, but the second trajectory can also relate to the next but one or the next but one consolidation path. In such a case, one consolidation path touches the next but one or the next but one consolidation path.
  • adjacent consolidation tracks do not have to be at a distance from one another, but can also overlap one another by 5% or 10%.
  • the scanning of the second trajectory does not necessarily have to immediately follow the scanning of the first trajectory in terms of time. Rather, it is also possible to scan along other trajectories in the intervening time, even if a scan along the second trajectory immediately following the scan along the first trajectory is a preferred procedure.
  • a distance between an end point of a trajectory and a starting point of the temporally following trajectory can be determined on the basis of a comparison of the positions of the starting point and end point in the data model or data space.
  • half the beam width of the beam as the maximum value of the distance between the starting point and the end point
  • half the distance between the beam axes of the energy beam at the end point, i.e. the position of the coupling-out, and at the starting point, i.e. the position of the re-coupling can be selected as the maximum value.
  • This distance between the beam axes must then be selected so that it is smaller than 50% of the larger of the two beam widths, preferably smaller than 30%, even more preferably smaller than 10% of the larger of the two beam widths.
  • the distance between the start and end point is chosen so that the impingement surfaces of the beam bundles at the start and end point overlap one another by at least 50%.
  • the beam axis of an energy beam is defined in such a way that it runs through the geometric center of gravity of a virtual impact surface of the energy beam, which lies in a plane of intersection through the energy beam that is perpendicular to the beam axis.
  • the beam axis can be through a center point of the virtual The impact surface run and / or be identical to a beam propagation direction.
  • an intensity distribution of an energy beam includes the spatial shape or expansion of the energy beam in the cutting plane (cross-sectional area) perpendicular to the beam axis and also the spatial distribution of the intensity over the cross-sectional area, i.e.
  • a beam expansion is to be understood as any dimension or expansion of the impingement surface of the beam at right angles to the direction of movement of the beam in the building plane, in particular a beam width, whereby a beam width always means the expansion perpendicular to the current direction of movement of the impingement area on the construction field is.
  • the beam expansion does not necessarily have to run through the beam axis or the center of the intensity distribution in the building plane, in particular if the energy beam does not have a rotationally symmetrical intensity distribution and / or strikes at an angle.
  • the beam expansion is defined here in such a way that it runs from one edge to the opposite edge of the intensity distribution in the building plane, whereby the edge is arbitrarily defined here so that 95%, preferably 99% of the radiation power of the energy beam is within the edge (i.e. in the through the edge of the enclosed area) hit the building level.
  • a beam expansion or beam width of a beam can in particular be determined in such a way that the surface is initially at a perpendicular incidence of the radiation an area of the building level is determined in which 95% or 99% of the radiation power reach. This can be done, for example, by arranging a radiation measuring device, for example a semiconductor detector or an IR camera, in the construction level.
  • the determination of the beam expansion is preferably carried out at a radiation power which is of the same order of magnitude as the radiation power used to solidify the building material.
  • the impingement surface of the beam has an eccentricity, which is understood here to be the ratio between the largest diameter and the smallest diameter
  • half of a mean diameter of the beam can be used as the maximum distance between the starting point of the second trajectory and the end point of the previously scanned first trajectory to be set.
  • the mean value over all sections through the impingement surface of the beam corresponds to the mean diameter.
  • the mean diameter can be determined in such a way that first the area of the area of the building level is determined in which 95% or 99% of the radiation power reach. A diameter of a symmetrical figure with the same area is then defined as the mean diameter. If the impingement surface has an elliptical shape, for example the diameter of a circle with the determined area or the determined surface area can be regarded as the mean diameter of the beam. In cases in which the impact surface has a polygonal shape, the diameter of a circumference around a regular polygon, for example a pentagon, can alternatively be defined as the mean diameter.
  • control data provided for the generation of a control data set can consist of the at least one data model itself generated in the second step, and the at least one data model can also be prepared in accordance with any format requirements for integration into the control data set.
  • the build-up material is melted using a deep welding process during selective laser beam sintering or laser beam melting.
  • a deep penetration welding process temperatures are generated in the material that are so high that evaporation occurs and, in particular, the radiation penetrates into a vapor capillary on the surface of the material.
  • the temporarily formed vapor capillary is also referred to as a "keyhole". If the radiation power hitting the starting point is increased at the starting point of a consolidation path, then a keyhole first has to be formed for a stable melting process.
  • the weld pool extends to a depth that corresponds to two to three times the layer thickness. In particular, this means that material must first be evaporated, which can lead to increased formation of cracks.
  • the starting point (better starting area) of a consolidation path overlaps with the end point (better end area) of a previous consolidation path. This allows you to take advantage of the following effect at the end point of a consolidation path:
  • the radiation power hitting the end point is reduced too abruptly so much that the energy input per unit area falls below the energy per unit area required to melt the building material (for example by switching off the beam), then as a result of the rapid solidification process of the melted build-up material in the solidified object, the temporarily formed vapor capillary, so the "keyhole", no longer with melted material fill so that a crater is formed. Since in the procedure described the starting point of a trajectory is very close to the end point of a previously scanned trajectory, when the beam is switched on again at the starting point of the subsequent trajectory, the beam at least partially penetrates this crater.
  • a multiple reflection of the beam on the crater walls improves the absorption of radiation and, despite the continued movement of the beam, the stable end state in which a deep welding process takes place can be reached close to the starting point. As a result, there is less material ejection, which results in better component quality. Furthermore, the per se disadvantageous crater at the end point of a consolidation path is at least partially eliminated during the movement of the beam away from the starting point when the second consolidation path is scanned.
  • the component quality can be improved even with only a partial overlap, since the heating process of the building material can take place more quickly at the starting point even with a partial overlap.
  • the positions of the starting point and the end point specified in the data model generated in the second step are preferably at a distance from one another that is less than 50% of the beam width of the beam at the end point of the first trajectory, more preferably a distance that is less is than 30% of the beam width, most preferably a distance that is less than 10% of the beam width.
  • the invention in all of its configurations is not limited only to the transition from a first trajectory to a second trajectory. Rather, it is possible to proceed in the manner described for all transitions from one trajectory to a subsequent trajectory in an object section.
  • the procedure can be carried out within an entire object cross-section or a partial area of the same, even for an entire object to be produced, be carried out consistently. In other words, a transition from one trajectory to the next always takes place in the same way.
  • control data for the production of a three-dimensional object from metal-based construction material are preferably provided and the radiation power impinging on the starting point, preferably the radiation power specified for the second trajectory during the scanning of the entire second trajectory, and / or the radiation power impinging on the end point, is preferred the radiation power specified for the first trajectory during the entire scanning along the first trajectory, determined in such a way that a deep welding process takes place when the radiation acts on the building material.
  • the investigation of the nature of the welding process can e.g. B. by observing the weld pool by means of a camera (optical, IR, UV), by analyzing the radiation emitted by the weld pool or by analyzing test objects produced in preliminary tests.
  • a camera optical, IR, UV
  • emissions that are caused by the vapor capillary generated during the deep welding process i.e. spatter or jets as well as metal vapor, can be used.
  • Another criterion is the aspect ratio of the weld pool (width of the weld pool parallel to the working plane in relation to the depth, ie perpendicular to the working plane), which should be below 1 in the deep welding process, or the surface temperature of the build-up material.
  • a first movement speed v1 is defined in the method for moving the beam along the first trajectory, the beam being moved over the end point with at least 80%, preferably at least 90%, even more preferably 100% of the value of the first movement speed v1 , and / or set a second movement speed v2 for the movement of the beam along the second trajectory, the Beam bundle is moved over the starting point with at least 80%, preferably at least 90%, even more preferably with 100% and / or at most 120%, preferably at most 110% of the value of the second movement speed v2.
  • the direction of incidence of the beam of the beam at the starting point of the second trajectory is more preferably selected so that it forms an angle with the direction of incidence of the beam at the end point of the first trajectory that is smaller than 15 °, preferably smaller than 10 °, even more preferably is smaller than 5 °, particularly preferably smaller than 1 °.
  • the bundle of rays When the end point of the first trajectory is scanned, the bundle of rays does not strike the building plane perpendicularly but at an angle, the Form the steam capillary so that it does not extend vertically, but at an angle into the depth. So that the bundle of rays can then penetrate well into the remaining crater when the starting point of the second trajectory is scanned, the bundle of rays should impinge on the building plane from approximately the same direction.
  • the direction of incidence can be easily defined by spherical coordinates with the origin of coordinates at the starting point or end point, i.e. by specifying an angle in the building plane and an angle against the perpendicular to the building plane.
  • the bundle of rays is perpendicular to the building plane
  • the bundle of rays should also be as perpendicular to the building plane as possible.
  • the second trajectory is scanned with a different beam than the first trajectory, it is important to ensure that the solid angle that the two directions of incidence enclose is limited. If the beam for scanning the second trajectory is directed onto the building plane by means of a different scanner than the beam for scanning the first trajectory, then the other scanner usually has a different position above the building plane, which automatically results in a different direction of incidence. The specification of an upper limit value for the angle thus has an influence on the decision with which beam bundle which trajectory can be scanned.
  • a different beam is directed onto the starting point of the second trajectory than that which was directed onto the end point of the first trajectory.
  • the transition from scanning the first trajectory to scanning the second trajectory can take place quickly.
  • a change in the direction of movement of the beam and / or a delay / acceleration of the movement does not have to be undertaken in a possibly complex manner, since the other beam is directed onto the second trajectory with the aid of a different deflection device than that for scanning the first trajectory.
  • a consolidation of the building material is also preferably specified, section by section, each section having a plurality of the first and second trajectories, with at least a first and second section being adjacent to one another at a boundary so that the start and end points of the first and second trajectories of the first sub-area adjoin the start and end points of the first and second trajectories of the second sub-area, with starting points of the second trajectories of one sub-area at the boundary opposite a gap between starting points of the second trajectories in the other sub-area and / or a gap are opposite between the second trajectories of the other sub-area.
  • the sub-areas mentioned can be, for example, the sub-areas 53 shown in FIG. 10, that is to say strip-shaped or square areas.
  • the construction material is scanned with a beam bundle like hatching along trajectories (hatch lines), the trajectories often running essentially parallel to one another.
  • the start and end points of the individual trajectories usually define the boundary of their sub-area, so that on a boundary between two sub-areas, the start and end points of trajectories are adjacent to those in the other sub-area, i.e. they border one another.
  • the positions of the start and end points in the respective sub-areas are selected so that the start and end points are not exactly opposite one another on the boundary line running between the two sub-areas, so that a starting point in one sub-area is the space between two starting points in is opposite to the other sub-area or an end point in one sub-area is opposite the space between two end points in the other sub-area.
  • those points in the other sub-area at which there is a large distance to adjacent start / end points of the other sub-area can be supplied with heat energy during the consolidation of the start / end points in one sub-area, so that a more uniform consolidation of the Construction material at the border between the sub-areas is taken care of.
  • the distances between the start / end points and the border between the partial areas should preferably be less than 10% of the minimum value for the beam widths of the beam bundles at the end points of trajectories adjoining the border, more preferably less than 5%. Even more preferably, the two partial areas should overlap one another at the border, particularly preferably by at least 50% of the beam width.
  • the start / end points of one sub-area are arranged between trajectories of the other sub-area, which can ensure even greater homogeneity of the properties of the object after it has solidified, since the two sub-areas have an interlocking of trajectories at their boundary.
  • the radiation power hitting the end point must be reduced so far that no evaporation of build-up material (keyhole formation) takes place beyond the end point.
  • a 100% reduction in the radiation power that causes this can be brought about by switching off the radiation source, e.g. the laser, or by deflecting the beam so that it hits other points on the building level or not the building level at all more hits.
  • the radiation power can be reduced at least so much that it cannot cause the melting temperature or solidus or liquidus temperature of the building material to be exceeded when the beam continues to move beyond the end point.
  • the radiation power incident on the end point can be reduced, for example, by reducing the output power of the radiation source or by adding an attenuator.
  • the radiation source for example, the pulse duty factor and / or the pulse frequency can also be modified accordingly.
  • the beam can also be defocused to such an extent that the energy input per unit of time and area is no longer sufficient to cause solidification or melting of the building material.
  • the starting point of the second trajectory it is further preferred at the starting point of the second trajectory to increase the radiation power impinging on the starting point to at least 50%, preferably at least 80%, even more preferably at least 90%, even more preferably at least 100% of the mean radiation power impinging on the second trajectory during the movement of the Specified beam along the second trajectory.
  • the radiation power must not already have values before reaching the starting point at which evaporation of the building material takes place when the beam moves over the building material.
  • the radiation power impinging on the second consolidation path be increased to values that are suitable for evaporation of building material.
  • the radiation power preferably has a value at which sintering or melting of building material does not yet take place, that is, a solidus or liquidus temperature of the building material is not yet exceeded.
  • mean radiation power impinging on the second trajectory refers to the fact that the impinging radiation power can vary when the second trajectory is scanned. If the radiation power impinging on the second trajectory does not vary during the scanning of the second trajectory, then the value of the mean impinging radiation power is equal to the constant value of the radiation power impinging on the second trajectory when scanning the second trajectory.
  • the radiation power can be increased, for example, by increasing the output power of the radiation source.
  • the pulse duty factor can also be used, for example and / or the pulse rate can be modified accordingly.
  • the beam can also be focused more strongly, so that the energy input per unit of time and area is sufficient to bring about a solidification or melting of the building material.
  • a movement of the preferably fictitious beam on a continuous reversal path is also preferably specified, which preferably intersects at at least one point.
  • an oval or a polygon can be traversed, whereby a corner is present where the start / end point is located, the interior angle of which is equal to the angle between the direction of movement of the beam to the end point towards and the direction of movement of the beam is away from the starting point.
  • the shape can be selected so that a transition time from the first trajectory to the second trajectory is as short as possible or, for example, the deflection or scanning device is subjected to as little thermal and / or mechanical stress as possible during the movement.
  • the beam is preferably switched off when traveling the continuous reversing path and a beam deflecting device (eg a scanner) is nevertheless moved or controlled as if the beam was switched on, ie it is a fictitious beam.
  • the direction in the construction plane in which the beam is moved away from the end point of the first trajectory and the direction in the construction plane in which the beam is moved to the starting point of the second trajectory preferably close (corresponding to the direction of movement from Starting point of the second trajectory away along the second trajectory), an angle that is greater than or equal to 20 ° and / or less than or equal to 100 °.
  • the result is that the first consolidation path and the second consolidation path must touch one another at their end.
  • the directions of movement of the beam at the end point of the first trajectory and at the starting point of the second trajectory differ from one another by a minimum angle.
  • a maximum angle between the directions of movement should not be exceeded: If there is too great a deviation between the directions of movement, the penetration of the beam at the starting point into the crater created by the reduction in radiation power at the end point is more difficult.
  • the first angle can be established, for example, in such a way that the angle between the respective tangents to the consolidation paths at the start or end point is determined in the building plane.
  • the first trajectory and / or the second trajectory preferably have a curved path section.
  • the present invention relates primarily to hatch lines.
  • a hatch-like scanning (scanning) of the building material solidifies it in one area.
  • the hatch lines are generally straight over at least 70% of their length, preferably at least 90% of their length.
  • neighboring consolidation tracks can overlap their start / end point it is not necessary that both consolidation tracks have a curvilinear course at their respective end. Rather, one of the two consolidation tracks can be 100% straight, while only the other has a curved track section at its end.
  • any variations of the courses of neighboring trajectories that lead to an overlap of the starting point and end point are possible.
  • the first and second trajectories can be (axially) symmetrical to one another, as a result of which the start / end point then lies in the middle between the two trajectories.
  • courses of the first and second trajectories that are asymmetrical to one another are also conceivable, which then results in a position of the start / end point that is closer to one of the two trajectories.
  • the position of the start / end point with respect to the first and second trajectories is preferably retained for an entire partial area of a cross section of the object to be manufactured or an entire cross section or the entire object to be manufactured.
  • the inventive procedure is equally advantageous if the trajectories not only have curvilinear sections at their ends, that is to say there is also a deviation from the straight course away from the start / end point of the trajectories.
  • trajectories can also be curvilinear as a whole.
  • the curved path section of the first trajectory and / or the second trajectory preferably comprises at least 1%, preferably at least 5% and / or a maximum of 50%, preferably a maximum of 30%, more preferably a maximum of 20% of the length of the trajectory.
  • a lower limit for the length of the curved path section prevents excessive curvatures, in particular near the start / end point. This is because small radii of curvature lead to high acceleration values at the deflecting devices (for example galvanometer mirrors) and thus to inaccuracies due to the inertia of the deflecting device and furthermore to high loads for the galvanometer drives.
  • the upper limit for the length of the curved path section expresses that trajectories should preferably have as straight a course as possible, on the one hand to avoid cornering accelerations, on the other hand because they should be as straight as possible
  • the course of the trajectories allows a simpler scanning strategy for an area to be consolidated.
  • an additive manufacturing method for manufacturing a three-dimensional object, the object being manufactured by means of an additive manufacturing device by applying a building material layer on layer and solidifying the building material in a building plane by supplying radiant energy to locations in each layer that correspond to the cross section of the object are assigned to this layer by scanning these points with at least one beam according to a set of energy input parameter values along a plurality of trajectories, the sequence of the additive manufacturing process is controlled by a control data set that was generated using a method according to the invention for providing control data.
  • control data provided according to the invention are used in a control data set that was generated for the control of an additive manufacturing process, in particular the control of a layered additive manufacturing process, such as a layered powder melting or sintering process, such as SLS or DMLS or SLM, then the component homogeneity of the Object to be improved.
  • a layered additive manufacturing process such as a layered powder melting or sintering process, such as SLS or DMLS or SLM
  • an area to be selectively solidified along a first solidification path and a second solidification path essentially parallel to it is melted by irradiation with at least one beam, so that the material is in a solid state after a cooling process.
  • the motion vectors of the beam bundles in the building plane preferably have mutually opposite directional components when scanning along the consolidation paths.
  • the motion vectors can be arranged rotated by 180 ° with respect to one another.
  • an end point of the first consolidation path overlaps with a starting point of the second consolidation path at least to such an extent that the melt pool generated by the beam bundle at the start point of the second consolidation path overlaps the The end point of the first consolidation path is covered by a crater that occurs during a deep welding process.
  • the end point of the first consolidation path is at a distance from the starting point of the second consolidation path that is less than half the beam width of the beam at the end point, preferably less than a quarter of the beam width of the beam at the end point.
  • the end point of the first consolidation path which coincides with the end point of the first trajectory, can be viewed approximately as the geometric center or center of area of the melt pool generated at the end point by the beam in the construction plane.
  • the starting point of the second solidification path coincides with the starting point of the second trajectory and can be viewed approximately as the geometric center of the melt pool generated at the starting point by the beam bundle in the building plane.
  • the object is preferably made from a metal-based building material and so much radiant energy is supplied to solidify the building material that it is melted in a deep welding process, the radiant power of the beam arriving at the end point of the first trajectory being set so that a depression forms at the end point in the build-up material as a result of the deep welding process and the position of the starting point of the second trajectory is selected so that the beam directed at the starting point at least partially, preferably completely, impinges on the depression.
  • a device for providing control data for an additive manufacturing device for manufacturing a three-dimensional object, the object being manufactured by means of the additive manufacturing device by applying a building material layer on layer and solidifying the building material in a building level by supplying radiant energy to locations in each layer, associated with the cross-section of the object in this slice, by placing these points with at least one beam according to a set of Energy input parameter values are sampled along a plurality of trajectories, has: a data access unit which is designed to access computer-based model data of at least one section of the object to be produced, a data model generation unit which is designed to selectively produce at least one data model for producing the at least one object section To generate the area of a building material layer to be solidified, the data model specifying solidification of the building material by scanning locations of the area to be selectively solidified along a first trajectory and a second trajectory adjacent thereto with at least one beam, the motion vectors of the beam in the building plane in the scanning of the two trajectories have mutually opposite directional components,
  • the provision of the data model generated in the second step for the generation of a control data set can be done by the control data provision unit itself by integrating the generated data model into a control data set for the additive manufacturing device.
  • providing also includes forwarding the data model to a data processing device which integrates the data model into a control data record, or direct forwarding to an additive manufacturing device.
  • data models generated in the second step do not have to be provided individually for an additive manufacturing process. Rather, several can also be generated Data models are first collected and then made available in their entirety for integration into a control data set.
  • the provision can also include generating the data model.
  • a device for computer-aided control of a number of energy input devices of an additive manufacturing device for manufacturing a three-dimensional object by means of the same, the object being manufactured by means of the additive manufacturing device by applying a build-up material layer on top of a layer and solidifying the build-up material in a building level by supplying radiant energy in each layer, which are assigned to the cross-section of the object in this layer, in that these locations are scanned with at least one beam according to a set of energy input parameters along a plurality of trajectories, is designed so that a solidification of the building material by scanning locations of the selectively area to be solidified is specified along a first trajectory and a second trajectory adjacent thereto with at least one beam, the motion vectors of the beam have opposite directional components in the building plane when scanning the two trajectories, it being specified that a starting point of the second trajectory is at a distance from an end point of the previously scanned first trajectory that is less than half the beam width of the beam at the end point of the first Trajector
  • the device for the computer-aided control of a number of energy input devices can be implemented solely by means of software components, by means of a mixture of hardware and software components, or even solely by means of hardware components.
  • a device implemented solely by means of software components can interact in particular with a control device in an additive manufacturing device for the production of a three-dimensional object or be integrated in such a control device.
  • the device for the computer-aided control of a number of energy input devices the component homogeneity can be reduced by an additive Manufacturing process produced objects are improved.
  • the device can implement the production of objects by means of an additive production method on the basis of a control data set that was generated by means of a method according to the invention for providing control data.
  • An additive manufacturing device for manufacturing a three-dimensional object, the object being manufactured in the additive manufacturing device by applying a building material layer on layer and solidifying the building material by supplying radiant energy to locations in each layer that are assigned to the cross-section of the object in this layer by scanning these points with at least one beam according to a set of energy input parameters along a plurality of trajectories, has: a layer application device which is suitable for applying a layer of a building material to an already existing, preferably already selectively solidified, building material layer, an energy input device , which is suitable for supplying the cross-section of the object in a layer assigned points of radiation energy by these points with at least one beam according to a set of energy input p parameter values are scanned along a plurality of trajectories, the additive manufacturing device according to the invention having a device according to the invention for computer-aided control of a number of energy input devices of an additive manufacturing device and / or being connected to such a device for signaling purposes.
  • An energy input device can include a number of radiation sources for generating radiation, for example electromagnetic radiation or particle radiation, as well as an associated number of beam deflection or deflection devices for directing the radiation onto the building material.
  • the radiation sources can, for example, be one or more gas or solid-state lasers or any other type of lasers such as laser diodes, in particular VCSELn (Vertical Cavity Surface Emitting Laser) or VECSELn (Vertical External Cavity Surface Emitting Laser) or a line of these lasers act.
  • control data when the control data is generated in the additive manufacturing device, it can dynamically generate data models for object (partial) cross-sections still to be manufactured during a manufacturing process by means of the data model generation unit.
  • a computer program according to the invention has program code means in order to carry out all steps of a computer-aided method according to the invention for providing control data for an additive manufacturing device and / or an additive manufacturing method according to the invention when the computer program is executed by means of a data processor, in particular a data processor cooperating with an additive manufacturing device.
  • Interaction here means that the data processor is either integrated into the additive manufacturing device or can exchange data with it.
  • the implementation of the method according to the invention for providing control data and the associated device by means of software enables simple installation on different EDP systems at different locations (for example at the creator of the design of the object or at the operator of the additive manufacturing device).
  • FIG. 1 shows a schematic, partially sectioned view of an exemplary device for the additive manufacture of a three-dimensional object according to an embodiment of the invention
  • FIG. 2 shows schematically an example of the procedure according to the invention when consolidating a strip-shaped partial area ("hatch") of an object cross-section
  • 3 and 4 schematically show further examples of possible courses of the trajectories at the start / end point according to the invention
  • FIG. 5 shows schematically the directing of the beam onto a starting point of a consolidation path which coincides with an end point of the preceding consolidation path, with a depression remaining at the end point as a result of an abrupt reduction in the radiation power supplied by the beam that does not hit the building plane perpendicularly,
  • Fig. 6 shows schematically a preferred procedure at the border between two sub-areas
  • FIG. 8 shows the schematic structure of a device for providing control data
  • FIG. 11 serves to further explain the procedure shown in FIG. 10.
  • the laser sintering or laser melting device 1 contains a process chamber or construction chamber 3 with a chamber wall 4.
  • a construction container 5, which is open at the top and has a container wall 6, is arranged in the process chamber 3.
  • a working plane 7 (also called a construction plane) is defined through the upper opening of the construction container 5, the area of the working plane 7 lying within the opening, which can be used to construct the object 2, being referred to as construction field 8.
  • a carrier 10 which is movable in a vertical direction V and to which a base plate 11 is attached, which closes off the container 5 at the bottom and thus forms its bottom.
  • the base plate 11 can be a plate formed separately from the carrier 10 and attached to the carrier 10, or it can be formed integrally with the carrier 10.
  • a construction platform 12 can also be attached to the base plate 11 as a construction base, on which the object 2 is built.
  • the object 2 can, however, also be built on the base plate 11 itself, which then serves as a construction base.
  • FIG. 1 the object 2 to be formed in the container 5 on the building platform 12 is shown below the working plane 7 in an intermediate state with several solidified layers, surrounded by building material 13 that has remained unsolidified.
  • the laser sintering or melting device 1 furthermore contains a storage container 14 for a building material 15, in this example a powder that can be solidified by electromagnetic radiation, and a coater 16 movable in a horizontal direction H for applying the building material 15 within the building field 8.
  • a heating device for example a radiant heater 17, can be arranged in the process chamber 3, which is used to heat the applied building material.
  • An infrared radiator for example, can be provided as the radiant heater 17.
  • the exemplary additive manufacturing device 1 furthermore contains an energy input device 20 with a laser 21 which generates a laser beam 22 which, via a deflection device 23, for example one or more Galvanometer mirror together with the associated drive is deflected and is focused on the working plane 7 by a focusing device 24 via a coupling window 25 which is attached to the top of the process chamber 3 in the chamber wall 4.
  • a deflection device 23 for example one or more Galvanometer mirror together with the associated drive is deflected and is focused on the working plane 7 by a focusing device 24 via a coupling window 25 which is attached to the top of the process chamber 3 in the chamber wall 4.
  • an energy input device can, for example, one or more gas or solid-state lasers or any other type of laser such as laser diodes, in particular VCSEL (Vertical Cavity Surface Emitting Laser) or VECSEL (Vertical External Cavity Surface Emitting Laser), or a line of these lasers exhibit.
  • VCSEL Vertical Cavity Surface Emitting Laser
  • VECSEL Very External Cavity Surface Emitting Laser
  • FIG. 1 The specific structure of a laser sintering or melting device shown in FIG. 1 is therefore only exemplary for the present invention and can of course also be modified, in particular when using a different energy input device than that shown.
  • the term “beam” is often used synonymously with “beam” in this application.
  • the laser sintering device 1 furthermore contains a control device 29, via which the individual components of the device 1 are controlled in a coordinated manner in order to carry out the construction process.
  • the control device can also be attached partially or entirely outside of the additive manufacturing device.
  • the control device can contain a CPU, the operation of which is controlled by a computer program (software).
  • the computer program can be stored separately from the additive manufacturing device in a storage device, from where it can be loaded (e.g. via a network) into the additive manufacturing device, in particular into the control device.
  • the carrier 10 is lowered layer by layer by the control device 29, the coater 16 is controlled to apply a new powder layer and the deflecting device 23 and, if necessary, the laser 21 and / or the focusing device 24 are controlled to solidify the respective layer on the the respective object corresponding points by means of the laser by scanning these points with the laser.
  • a manufacturing process takes place in such a way that the control unit 29 processes a control data record.
  • the control data set specifies to an energy input device, in the case of the above laser sintering or laser melting device, specifically the deflection device 23, for each point in time during the solidification process, at which point on the working plane 7 radiation is directed.
  • an apparatus 100 for providing control data for an additive manufacturing device contains a data access unit 101, a data model generation unit 102, and a control data provision unit 103 7 described by way of example.
  • the data access unit 101 first accesses a number, that is to say one or more, of layer data records, each of which is a data model of a region of a building material layer to be selectively solidified during manufacture , preferably of the entire area to be solidified of a building material layer, which corresponds to a cross section of an object section. In the process sequence shown in FIG. 7, this is the first step S1.
  • the data model generation unit 102 now specifies in at least one data model of the at least one object section a consolidation of locations of a building material layer in one temporal sequence that corresponds to the movement of a beam along a trajectory over the building material.
  • the movement along trajectories 54 shown in FIGS. 10 and 11 is defined in an inner region 52 of an object cross-section 50, in particular in a partial region 53 of inner region 52, that is, for example, a strip.
  • control data provision unit 103 shown in FIG. 8 then provides control data for the generation of a control data record (in FIG. 7 this is step S3).
  • Either the at least one data model generated in the second step S2 can be provided as control information (control data) or the data model is reformatted into a control data record for better integrability.
  • the procedure described can be used for all trajectories within a strip-shaped or square sub-area.
  • FIG. 2 shows a detail from a partial area 53 of an inner area 52, on the basis of which the differences to the prior art procedure shown in FIG. 11 are to be clarified.
  • the directions in which a beam is moved along the flatch lines are again indicated by arrows.
  • Adjacent flatch lines are traversed in the opposite direction, so that in the figure one can distinguish between flatch lines 74a, 74b traversed from left to right and flatch lines 75 traversed from right to left.
  • the flatch line 75 is scanned after the flatch line 74a and the flatch line 74b is scanned after the flatch line 75.
  • the starting point 75A of the second hatch line 75 that is to say the location of this hatch line scanned first in time, essentially coincides with the end point 74aE of the first hatch line 74a, that is to say the location of this hatch line scanned last in time.
  • the starting point 74bA of the third hatch line 74b essentially coincides with the end point 75E of the second hatch line 75.
  • the deflection device 23 is activated in this example in such a way that the beam is moved on a continuous reversing path 76.
  • this section 76 either the radiation power supplied to the building material by the beam is weakened so much that the boiling temperature is not exceeded, in particular the melting temperature or solidus or liquidus temperature of the building material is not exceeded, in other words no solidification of the Building material is effected, or the radiation power per unit area (irradiance) is reduced to a value close to zero, e.g. B. by blocking or interrupting the radiation or switching off the radiation source.
  • Activating the deflection device 23 in such a way that the non-existent beam is moved along the continuous reversing path 76 even when the laser is switched off enables a braking process of the galvanometer mirror of the deflection device 23 at least partially after the energy input device has been switched off or an acceleration process of the galvanometer mirror of the deflection device 23 can be carried out at least partially before the energy input device is switched on, with braking or acceleration under certain circumstances also being able to be carried out completely in the reversal zone with alternating hatches.
  • the continuous reversal path 76 is selected in such a way that an optimal reversal process is guaranteed.
  • a minimum or maximum reversal time that is to say the time within which the path 76 is traversed, can be selected as the optimization criterion.
  • the path 76 can be selected so that the deflection device 23 is operated as energy-efficiently as possible or a galvanometer drive is loaded as little as possible.
  • FIG. 9 it is explained below how the course of the trajectories specified in the data model on which the control data is based affects the manufacturing process in the additive manufacturing device.
  • FIG. 9 schematically shows a top view of the building plane in the area of the first hatch line (trajectory) 74a and the second hatch line (trajectory) 75 of FIG. 2.
  • FIG. 9 also illustrates the edges 740 and 750 of the two trajectories 74a and 75, respectively assigned areas (solidification tracks) in which the build-up material is melted due to the movement of the laser beam along the trajectory and which for this reason are also referred to as melting traces.
  • an exemplary circular beam 745, 755 is shown on both trajectories in order to illustrate the size relation between the width B of this beam on the one hand, i.e. the extent perpendicular to the respective trajectory, and the width B 'of the melt track on the other hand.
  • the area 746, 756 melted by each of the two beam bundles is also shown approximately circular.
  • the regions 740 and 750 which correspond to the hardened consolidation tracks, overlap one another, as is often the case, in order to avoid gaps of unsatisfactorily consolidated building material between the consolidation tracks.
  • the width of the overlap area is selected, for example, between 5% and 10% of the width of one of the reinforcement webs 740 or 750.
  • FIG. 9 a crater 80 which has remained at the end 74aE of the trajectory 74 due to the switching off or reduction of the beam power, which was already mentioned above. It should be emphasized that this crater 80 is only shown very schematically. It will not necessarily have the circular shape shown in the figure and will tend to have a smaller diameter than the consolidation web 740. The end point 74aE will also normally not lie exactly in the center of the crater 80.
  • FIG. 9 shows, by means of a dashed curve, a (fictitious) movement of the beam along the reversing trajectory 76 brought about by the beam deflecting device 23.
  • the movement is referred to as fictitious, since after the beam is switched off the scanning of the end point 74aE cannot actually be referred to as the movement of a beam. If the beam is not switched off after the end point 74aE has been scanned, but only the radiation power is reduced, then the dashed path 76 illustrates the movement of the beam in the building plane until it reaches the starting point 75A of the trajectory 75. As can be seen in FIG. however, no melting or solidification of building material takes place before starting point 75A is reached.
  • the starting point 75A in this example does not lie exactly in the center of the crater 80 or at the location of the end point 74aE, even if this would be desirable.
  • the figure is intended to illustrate the conditions in reality, where there may well be a distance between the end point 74aE and the start point 75A. Such a distance can be tolerated as long as it is not greater than half the beam width B of the beam with which the first trajectory 74a is scanned at the end point 74aE, preferably not greater than a quarter of the beam width B, even more preferably less than 10% is the beam width B of the beam. It is important here that the molten pool created when the second trajectory 75 is scanned fills the crater 80 as far or completely as possible. As already mentioned above, it can then be ensured that a deep welding process is achieved in an accelerated manner when the second trajectory 75 is scanned.
  • the hatch line 84 is curvilinear near its end point 84E
  • the course shows, while the hatch line 85, beginning with its starting point 85A, shows a straight course, as shown in FIG. 4.
  • the start / end point is placed can also be made dependent on which shape of the continuous reversing path 76, 86 leads to the shortest possible transition time from the first hatch line to the second hatch line, or on the shape of the continuous reversing path 76, 86 leads to the lowest possible thermal and / or mechanical stress on the deflection device.
  • the bundle of rays preferably moves at the starting point of the second hatch line in the plan view of the building plane in essentially the same direction, more preferably in exactly the same direction, as the bundle of rays at the end point of the first hatch line.
  • the best results are achieved because the beam can then penetrate particularly well into the crater at the end of the first hatch line, especially if the angle between the direction of incidence of the beam at the starting point and that at the end point is very small, i.e. less than 10 °, preferably less than 5 °, particularly preferably less than 1 °.
  • good results can also be achieved if the direction when scanning the starting point deviates from the direction when scanning the end point by an angle which is less than 100 °, more preferably less than 90 ° and even more preferably less than 20 °.
  • the smallest possible deviation of the direction of movement of the beam when scanning the starting point compared to the direction of movement of the beam when scanning the end point is particularly important when the beam does not strike the construction plane perpendicularly.
  • a crater at the end point of the first consolidation path will not run perpendicular to the building plane, as is illustrated with reference to FIG. 5.
  • the angle of inclination a when scanning the starting point should be the same or at least similar to the angle of inclination against the building plane when scanning the end point.
  • the end points of the hatch lines define the edge of a sub-area 53.
  • the pairs of hatch lines 91 are positioned in sub-area 53b in such a way that at the boundary 100 between the two sub-areas the start / end points 97b of the pairs of hatch lines 91 are exactly between the start / end points. End points 97a of hatch line pairs 90 lie.
  • an overlap of the subregions 53a, 53b can optionally also be provided.
  • the sub-area 53a or the pairs of hatching lines 90 would be shifted in it in the direction of the sub-area 53b and / or the sub-area 53b or the hatching line pairs 91 would be shifted in it in the direction of the sub-area 53a.
  • the extent of the displacement of one sub-area in the direction of the other can be selected to be so large that it corresponds to half the beam width of a beam used in this sub-area, but is preferably less than, for example, a quarter of the beam width.
  • a device 100 according to the invention for providing control data for an additive manufacturing device can be implemented not only by software components, but also solely by hardware components or mixtures of hardware and software.
  • interfaces mentioned in the present application do not necessarily have to be designed as hardware components, but can also be implemented as software modules, for example if the data fed in or output can be taken over from other components already implemented on the same device, or to a other components only have to be transferred in terms of software.
  • the interfaces could consist of hardware and software components, such as a standard hardware interface that is specially configured by software for the specific application.
  • several interfaces can also be combined in a common interface, for example an input-output interface.

Abstract

L'invention concerne un procédé permettant de fournir des données de commande pour un dispositif de fabrication additive (1) destiné à fabriquer un objet tridimensionnel (2), ledit procédé comprenant : une première étape (S1) d'accès à des données de modèle informatiques d'au moins une partie de l'objet à fabriquer, une deuxième étape (S2) de formation d'au moins un modèle de données d'une zone d'une couche de matériau de construction à solidifier de manière sélective pour fabriquer ladite au moins une partie d'objet, un balayage de sites de la zone à solidifier de manière sélective le long d'une première trajectoire (74a, 84) et d'une seconde trajectoire (75, 85) sensiblement parallèle à la première étant spécifié avec au moins un faisceau de rayons, dans le modèle de données, les vecteurs de déplacement des faisceaux de rayons présentant dans le plan de construction, lors du balayage le long des deux trajectoires des composantes directionnelles opposées les unes aux autres, étant spécifié qu'un point de départ (75A, 85A) de la seconde trajectoire (75, 85) présente un écart avec un point terminal (74aE, 84E) de la première trajectoire (74a, 84) balayée au préalable, lequel est inférieur à une demi-largeur de rayon (B) du faisceau de rayons au niveau du point terminal (74aE, 84E) de la première trajectoire (74a, 84), et une troisième étape (S3), au cours de laquelle des données de commande sont fournies conformément audit au moins un modèle de données produit à la deuxième étape (S2) pour générer un jeu de données de commande pour le dispositif de fabrication additive.
EP20811561.8A 2019-12-10 2020-11-19 Inversion de hachurage à transfert de capillaire (keyhole) Pending EP4072754A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102019219276.9A DE102019219276A1 (de) 2019-12-10 2019-12-10 Hatchumkehr mit Keyhole-Übergabe
PCT/EP2020/082781 WO2021115756A1 (fr) 2019-12-10 2020-11-19 Inversion de hachurage à transfert de capillaire (keyhole)

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EP4072754A1 true EP4072754A1 (fr) 2022-10-19

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US (1) US20230008970A1 (fr)
EP (1) EP4072754A1 (fr)
DE (1) DE102019219276A1 (fr)
WO (1) WO2021115756A1 (fr)

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5182055A (en) * 1988-04-18 1993-01-26 3D Systems, Inc. Method of making a three-dimensional object by stereolithography
US20150367577A1 (en) * 2014-06-19 2015-12-24 Materialise N.V. Use of multiple beam spot sizes for obtaining improved performance in optical additive manufacturing techniques
EP3242762A1 (fr) * 2015-01-07 2017-11-15 EOS GmbH Electro Optical Systems Dispositif et procédé génératif de construction par couches permettant de produire un objet tridimensionnel au moyen d'une pluralité de rayons
DE102015207254A1 (de) * 2015-04-21 2016-12-01 Eos Gmbh Electro Optical Systems Vorrichtung und Verfahren zur generativen Herstellung eines dreidimensionalen Objektes
US11642725B2 (en) * 2016-01-19 2023-05-09 General Electric Company Method for calibrating laser additive manufacturing process
DE102017107362A1 (de) * 2017-04-06 2018-10-11 Amsis Gmbh Verfahren zur additiven Fertigung eines dreidimensionalen Bauteils und Verfahren zur Berechnung einer Scanstrategie zwecks entsprechender Ansteuerung einer Anlage zur additiven Fertigung eines dreidimensionalen Bauteils
DE102018205689A1 (de) 2018-04-13 2019-10-17 Eos Gmbh Electro Optical Systems Verfahren und Vorrichtung zur Verbesserung der Bauteilhomogenität von durch ein additives Herstellverfahren hergestellten Objekten
DE102018205688A1 (de) * 2018-04-13 2019-10-17 Eos Gmbh Electro Optical Systems Verfahren und Vorrichtung zur Verbesserung der Bauteilqualität von durch ein additives Herstellverfahren hergestellten Objekten
DE102018110294A1 (de) * 2018-04-27 2019-10-31 Eos Gmbh Electro Optical Systems Verfahren und Vorrichtung zur Generierung von Steuerdaten für eine Vorrichtung zur additiven Fertigung

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WO2021115756A1 (fr) 2021-06-17
US20230008970A1 (en) 2023-01-12

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