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
  • B22F10/30—Process control
  • B22F10/37—Process control of powder bed aspects, e.g. density
• • 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
  • B22F12/00—Apparatus or devices specially adapted for additive manufacturing; Auxiliary means for additive manufacturing; Combinations of additive manufacturing apparatus or devices with other processing apparatus or devices
  • B22F12/90—Means for process control, e.g. cameras or sensors
• • 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
  • B22F10/10—Formation of a green body
  • B22F10/14—Formation of a green body by jetting of binder onto a bed of metal powder
• • 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
  • 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
  • B22F10/85—Data acquisition or data processing for controlling or regulating additive manufacturing processes
• • 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
• • 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
  • B29C64/165—Processes of additive manufacturing using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• • 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
  • B29C64/20—Apparatus for additive manufacturing; Details thereof or accessories therefor
  • B29C64/205—Means for applying layers
  • B29C64/214—Doctor blades
• • 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
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—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
  • B33Y10/00—Processes of additive manufacturing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—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
  • 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 [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y50/00—Data acquisition or data processing for additive manufacturing
  • B33Y50/02—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
  • B22F2999/00—Aspects linked to processes or compositions used in powder metallurgy
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—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
  • B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
  • B33Y40/20—Post-treatment, e.g. curing, coating or polishing
• • 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 invention relates to a method for generating a 3D structure, in which a 3D structure is built up in layers in a 3D printer.
• the construction is computer-controlled from one or more liquid or solid materials according to specified dimensions and shapes.
• Specifications for the components or workpieces to be printed can be provided, for example, by so-called computer-aided design systems (CAD).
• CAD computer-aided design systems
• particulate building material also referred to as particulate material or powdery building material
• particulate material or powdery building material on a so-called building field in order to form a layer of non-solidified particulate material
• DE 102005022 308 A1 discloses a coater and a method for applying powdery layers in a device for producing a three-dimensional object by solidifying layers of a powdery material at the points corresponding to the respective cross-section of the object.
• the object to be achieved is to provide a device and a method for producing a three-dimensional object by solidifying layers of a powdery building material, with which the building time for the three-dimensional object can be shortened.
• the device has a coater, which can be moved over a construction field, for applying the layers of the powdery construction material in the construction field.
• the coater is designed with a stiff blade that is rigidly connected to the coater.
• the coater is provided with a heating device which is at least partially integrated into the coater. This makes it possible to have the powder already preheat as a layer during or before the application and thus shorten the overall construction time for the three-dimensional object.
• the aim is to provide a method and a material system with which constant material properties, in particular the flow properties of the building material, can be ensured during the construction process.
• the particulate construction material is applied to a construction field in a defined layer thickness by means of a coater.
• binder liquid is selectively applied to the building material via a print head, the binder liquid being polymerized by means of at least one activator introduced into the sand.
• the construction field is lowered by the layer thickness or the coater is raised by one layer thickness and these steps are repeated until the desired molded part is produced, with agents being introduced into the building material, the binder liquid and / or the activator or, with which the moisture content of the building material mixture can be regulated.
• the moisture in the sand is regulated.
• the water content and the liquid content are regulated or at least stabilized. In this way, essentially the same chemical and physical properties should always be achieved in the manufacture of the three-dimensional molded parts.
• this speed is also increased in order to carry out 3D printing in a smaller unit of time to be able to. In doing so, speeds or travel speeds of the work equipment over the construction field of 500 mm / s and more are achieved.
• a disadvantage of this known state of the art is that, for example, as a result of ever higher speeds when printing a layer in a 3D printer in areas susceptible to this or mechanically susceptible areas, partial areas in a layer that is currently to be built up or one below it are torn open or shifted Layer lying layer can be done. This results in defects in the three-dimensional end product, which reduce the quality and, in the worst case, lead to a reject product.
• the object of the invention is to provide a method for generating a 3D structure or layers of a 3D structure in a 3D printer, with which the layers are built up more reliably and precisely in a 3D printing process.
• the quality of the 3-D printing is to be ensured in critical areas in which partial structures of the 3-D structure can be torn open or shifted in a layer currently to be built up or in a layer below this layer.
• the method for generating a 3D structure in a 3D printer is used in all 3D printers or 3D printing machines in which a substrate application and / or a fluid application takes place, especially in 3D printers or 3D printing machines, in which the construction of the 3D structure is computer-controlled.
• Such 3D printers have a control unit which controls the structure of the layers during 3D printing and which control commands are transmitted in a machine-readable form or a machine-readable code.
• Such a machine-readable code with control commands that controls the generation of the layers during 3D printing can be generated from specifications for the components or workpieces to be printed by a computer-aided design system (CAD) and transmitted to the control unit of the 3D printer.
• CAD computer-aided design system
• This machine-readable code is usually a digital code, which usual standards or norms, such as the international standard ICE 61131 or the international standard ICE 61499, corresponds.
• errors in the 3D structure to be generated are understood to mean, in particular, tearing open and / or shifting areas or partial areas of the 3D structure to be generated in one or more layers.
• Areas in which a partial structure of the 3D structure to be generated is applied directly to the surface of a substrate are classified as critical areas, since in this case insufficient adhesion can occur between the partial structure to be applied and the substrate.
• the substrate is a surface on which the 3D structure to be generated is built up in layers and which is also referred to as the construction field or construction bed of a 3D printer.
• Such critical areas are also areas in which a partial structure of the 3D structure to be generated is to be applied to small partial structures of an underlying layer.
• small substructures arise, for example, when the dimensions of the substructures arranged in layers one above the other are so small that only low mechanical strengths are to be expected in the case of a stack-like construction of these substructures, for example.
• Such low strengths have substructures with the smallest possible dimensions, for example in the range of a length of 0.1 mm and a width of 0.1 mm up to dimensions in the range of a length of 5 mm or more and a width of 5 mm or more . These dimensions depend on the molding material, the processing speed of the molding material and the fluid properties. In addition, such critical areas can also comprise part of a current layer or be a complete layer, for example due to the expensive or complicated 3D structure to be produced.
• the length does not have to be the same as the width of the substructure.
• long but very narrow substructures in the range of the specified dimensions also have a low mechanical strength during construction.
• the alignment of such narrow and long structures is also important here. If a long and narrow partial structure, for example with the dimensions of a length of 20 mm and a width of 0.3 mm, has a longitudinal extension in the direction in which the working equipment of the 3D printer is moved over the construction field, then problems arise in the layer structure For example, only at the beginning and at the end of this partial structure if the speed of movement of the work equipment of the 3D printer over the construction field is too great.
• Such working means of the 3D printer are, for example, a stripping element such as a squeegee, a blade or a swing blade.
• this elongated partial structure is to be built up layer by layer with its longitudinal extension at an angle of 90 degrees to the direction in which the working equipment of the 3D printer is moved over the construction field, problems arise in the layer structure along the entire area this elongated partial structure if the speed of movement of the work equipment of the 3D printer over the construction field is too great.
• Another critical area is an area in which a partial structure of the 3D structure to be generated is applied to a substrate that does not offer sufficient support in the event that the speed of movement of the working equipment of the 3D printer over the construction field is too great.
• One such subsoil is particulate building material. This case occurs if, after the construction of one of the multiple layers of the 3D structure to be generated, a partial structure takes place at a point above the particulate building material by means of selective solidification or gluing of the particulate building material at the point of this partial structure, since this partial structure is not yet connected or Has connection point to the 3D structure to be generated. In this case, such a connection to the 3D structure is only established in the course of the 3D printing process in a layer to be generated later, which is at a greater distance from the construction bed.
• a critical area is recognized in the structure, data or driving data for this recognized critical area are generated and saved or documented.
• These data include at least one piece of information on the location or on a position of the identified critical area. Its position on or above the construction bed is thus known with corresponding coordinates, for example in an X, a Y and a Z direction of a coordinate system on the construction site.
• this data can also contain information on an outer contour or track curve of the substructure and / or its dimensions or extent, for example with a length and a width, also as Called bounding box. It is intended to transmit the data or driving data from the analysis, i.e. the identified critical areas, to the control unit. Such a transmission of the data to the identified critical areas can take place to the control unit independently or with the data which control the layer-by-layer construction of the 3D structure by the control unit.
• control unit compares the current position of the construction of the 3D structure with the position data of the critical areas and, in the event that a match is detected, changes the speed of movement of the working equipment of the 3D printer over the construction field.
• This change can be a strong reduction in the speed of movement in critical areas or particularly critical areas. Alternatively, this change can be a less severe reduction in the speed of movement in less critical areas.
• the substrate discharge i.e. the amount of substrate of the particulate substrate that is applied over the construction field per meter, or to adapt it to the changing speed of movement.
• the height of the applied particulate substrate is regulated or kept constant.
• a time for this advance can be determined.
• a distance can be determined in which the speed of movement is reduced before a critical area is reached.
• the control unit by comparing the current position of the construction of the 3D structure with the position data of the critical areas, recognizes when such a critical area is left. In this case, the speed of movement of the working equipment of the 3D printer over the construction field can be changed again, for example increased. Such an increase in the speed of movement can be continued until the speed of movement at which the working equipment of the 3D printer moved before reaching the critical area has been reached again. Alternatively, the increase in the speed of movement can be continued until a maximum possible speed of movement of the work equipment has been reached.
• a measure of the probability of defects occurring in the three-dimensional end product is determined by this critical area.
• this probability is high, provision is made to reduce the speed of movement of the working equipment of the 3D printer over the construction field more than in the case of a lower probability. In this way, particularly sensitive sub-areas of the 3D structure can be reliably generated, with a smaller reduction in the speed of movement of the work equipment in less sensitive sub-areas allowing a time advantage when generating the 3D structure.
• an amount of a particulate substrate to be applied to a layer is influenced as a function of the speed.
• the amount of the particulate substrate to be applied per unit of time is increased in order to achieve a constant layer thickness of the particulate substrate and vice versa.
• Fig. 1 an exemplary process sequence of the method according to the invention for generating a 3D structure in a 3D printer.
• FIG. 1 shows an exemplary process sequence of the method according to the invention for generating a 3D structure in a 3D printer.
• a step 1 the method for generating a 3D structure or layers of a 3D structure in a 3D printer starts.
• a second step 2 the analysis of the 3D structure to be generated is carried out in such a way that so-called critical areas are found within the 3D structure to be generated or within the layers of the 3D structure to be generated.
• the data on which the analysis is based for generating the 3D structure can be generated, for example, by means of a computer-aided design system and are available in a machine-readable form such as a digital code.
• critical areas i.e. mechanically susceptible areas in which partial structures can be torn open or shifted according to the examples given above.
• Position data for these areas are determined and saved in step 3. These position data can correspond, for example, to an X, a Y and a Z direction of a coordinate system on the construction field. Alternatively, only one X and one Y coordinate above the construction field and a number for the corresponding layer in which the critical area is located can be determined.
• step 6 If no critical areas are determined in step 2 in the analysis of the 3D structure to be generated, the method for generating a 3D structure is ended in step 6.
• the 3D printing takes place, controlled by a control unit, which converts the machine-readable data generated by the computer-aided design system and controls the 3D printing.
• the position data determined in step 3 are sent to the control unit controlling the 3D printing, such as a programmable logic controller (PLC), are transferred and flow into the control process of 3D printing accordingly.
• PLC programmable logic controller
• control unit changes or reduces the speed of movement of the work equipment of the 3D printer over the construction field in step 5.
• step 5 This reduction in the speed of movement of the work equipment can take place shortly before a critical area is reached in step 5. After leaving a critical area, the speed of movement of the work equipment is increased again in step 5, this increase in speed also being able to take place with a time delay.
• the speed of movement of the work equipment is increased, for example, until the speed driven before reaching the critical area or a maximum possible speed has been reached.
• parameters that are related to a change in the speed of movement such as the amount of particulate material to be applied to a layer per unit of time or the pressure of a blade with which the particulate material can be attracted and / or solidified, adapted speed-dependent by the control unit.
• the speed of movement of the work equipment is reduced by the control unit for an area which spatially extends far beyond a critical area.
• step 6 With the completion of the 3D print, the process for generating a 3D structure in step 6 is ended.
• such a movement speed of the work equipment of the 3D printer over the construction field can be 1000mm / s, while the movement speed of the work equipment in or in front of critical areas is reduced to 300mm / s.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Optics & Photonics (AREA)
• Automation & Control Theory (AREA)
• Plasma & Fusion (AREA)
• Analytical Chemistry (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Family Cites Families (38)

• 2020
  • 2020-06-13 DE DE102020003536.1A patent/DE102020003536A1/de active Pending
• 2021
  • 2021-06-09 CN CN202180042219.6A patent/CN115697593A/zh active Pending
  • 2021-06-09 EP EP21737553.4A patent/EP4164828A1/de active Pending
  • 2021-06-09 JP JP2022575903A patent/JP7839115B2/ja active Active
  • 2021-06-09 WO PCT/DE2021/000108 patent/WO2021249588A1/de not_active Ceased
  • 2021-06-09 US US17/998,663 patent/US12397509B2/en active Active
  • 2021-06-09 KR KR1020227044314A patent/KR20230025668A/ko active Pending

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