EP3921101A1

EP3921101A1 - System for generative manufacturing of a component and method

Info

Publication number: EP3921101A1
Application number: EP20700702.2A
Authority: EP
Inventors: Dieter Holz; Martin Schoepf; Michael Walther; Arne Stephen FISCHER; Marius Winter
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2019-02-06
Filing date: 2020-01-13
Publication date: 2021-12-15
Also published as: CN113438996A; JP2022520356A; CN113438996B; WO2020160876A1; DE102019201494A1; JP7180006B2; KR20210123316A

Abstract

The invention relates to a system (1) for the generative manufacture of a component (2) from a material powder, having a construction platform (11) for constructing the component (2), having at least one application portion for applying a powder layer (12) to the construction platform (11), having at least one irradiation portion (17) for selectively irradiating the powder layer (12), having a transport unit (7), wherein the transport unit (7) is designed to move and/or cause the construction platform (11) to travel in a system chamber (4) along a transport path, wherein the application portion and the irradiation portion (13) are spaced apart and/or adjacent along the transport path.

Description

description

title

Plant for additive manufacturing of a component and process

State of the art

System for the generative production of a component from a powdery material powder, with a building platform for building the component, with at least one application section for applying a powder layer to the building platform, with at least one irradiation section for selectively irradiating the powder layer.

Powder bed-based systems for the additive construction of components, for example 3D printing, are known in the prior art. Such systems have a linear structure, i.e. the powder coating works translationally within the process chamber and causes downtimes that significantly reduce the overall productivity of additive manufacturing processes. In the prior art, for example, multi-laser systems are used to increase the selectivity, in which several laser beams are used simultaneously to build several components in a process chamber.

The publication DE 10 2016 211 799 A1, which probably represents the closest prior art, describes a device for producing workpieces from a powder material. The device has a carrier device with at least one build-up container for the powdery material, from which the workpieces can be produced by selective melting and subsequent solidification by means of a machining beam inside the build-up container. At least one storage container has a separate distribution element which is rotatable about an axis relative to the fixedly arranged carrier device. One consideration of the invention is to provide a system in which assembly times for the component, as well as downtimes and waiting times for the system, are reduced.

Disclosure of the invention

A system for the additive manufacturing of a component having the features of claim 1 is proposed. Furthermore, a method for the additive manufacturing of a component having the features of claim 15 is proposed. Preferred and / or advantageous embodiments of the invention emerge from the subclaims, the description and the attached figures.

A system for the additive manufacturing of a component from a powdered material is proposed. The system is designed in particular to carry out a powder-bed-based build-up process, preferably a powder-bed-based printing process. The system forms, for example, a 3D printing system. The component and / or the material powder can comprise and / or form a metal, ceramic and / or plastic material. In particular, the system is designed as a selective laser melting system (SLM), as an electron beam-based assembly system (EBM) or an ion beam assembly process. In particular, the system has a system room. The plant room can for example be surrounded and / or delimited by a housing of the plant. The component is preferably a layer component and comprises more than two layers and / or fewer than 100 layers. The component preferably forms a flat component. The powdery material powder is, for example, a metal powder, a ceramic powder or a plastic powder. In particular, the material powder can comprise a binder.

The system comprises at least one building platform for building the component. The building platform has at least one flat section. The building platform and / or its flat section is preferably flat. In particular, the construction platform can form a metal support. For example, the construction platform is designed as a metal, plastic or ceramic plate. In particular, the construction platform can be designed as an endless material, for example as a sheet metal from a roll.

The system has at least one application section. The application section is in particular a flat or a volume section of the plant room. In particular, the application section and a building platform have at least temporarily an overlap. A powder layer can be applied to the building platform in the application section. In particular, the powder layer can be applied to an intermediate layer between the building platform and the free surface. For example, a previous powder layer has already been irradiated and / or cured, so that this powder layer is applied to the previous one. For example, the system has a powder application device for this purpose. The powder application device can have a reservoir for the material powder and / or the powder. The powder layer is created in particular from the material powder. For this purpose, the material powder in particular is applied over a large area in powder form. In particular, the application device has a doctor blade and / or a smoothing device for this purpose. The powder layer can completely fill the building platform; alternatively, the powder layer is only applied over a partial area of the building platform. The powder layer in particular has a powder layer thickness. The application section is arranged in particular in the plant room.

The system also has at least one irradiation section. The irradiation section is preferably a flat section in the system room, alternatively the irradiation section is a volume section of the irradiation room. The construction platform and / or the applied powder layer is preferably arranged and / or can be arranged at least temporarily in the irradiation section. The system has, for example, an irradiation device which can selectively irradiate the powder layer. The irradiation can take place, for example, as an irradiation with a laser, an ion or an electron beam. For example, the irradiation device has a laser, an ion source or an electron source for this purpose. As a result of the selective irradiation, the powder layer is melted in particular selectively, punctiform, linear and / or flat. After the irradiation, a Solidification step, so that the melted powder layer can solidify and solidify.

The system has a transport unit. The transport unit is designed to move, move and / or displace the construction platform in the plant room. The construction platform can be moved and / or moved along a transport path by means of the transport unit. The transport path is preferably a straight path; alternatively and / or in addition, the transport path can form an angled, curved and / or branched transport path. The transport route is preferably arranged entirely in the plant room. Alternatively, it can be provided that parts of the transport route are arranged outside the plant room. The transport unit is designed to transport the building platform from the application section to the irradiation section. If the system has several application sections and / or several irradiation sections, the transport unit is designed in particular to transport the construction platform from one application section to an irradiation section and from the irradiation section to further application sections and / or irradiation sections.

According to the invention it is provided that the application section and the irradiation section are spaced apart, arranged one after the other and / or adjacent to one another. In particular, the application section and the irradiation section are spaced apart along the transport path. The application section and the irradiation section can be separated from one another by a further section; alternatively, the irradiation section and the application section are adjacent to one another without a transition.

One consideration of the invention is to provide a system for the more effective and / or faster production of a component by means of a generative production process. In particular, it is a consideration to reduce and / or combine idle times, changeover times and / or preparation times. This is achieved in particular by the fact that the coating and irradiation are temporally and / or spatially decoupled from one another. Instead of letting the construction platform remain in a fixed position during the construction process, as has been the case up to now, and possibly only the plate lowering can be done by moving the construction platform during the construction within the system, applying powder and exposing sequentially arranged and used. In particular, the duration of the build-up per component is no longer given as the pure sum of all coating and exposure processes, but is only determined from the duration of the individual exposure processes.

One embodiment of the invention provides that the system has a plurality of application sections and a plurality of irradiation sections. The number of application sections preferably corresponds to the number of irradiation sections. For example, all application sections and all irradiation sections are arranged within a common housing of the system and thus in a common system room. The application sections and irradiation sections are arranged along the transport path. In particular, application sections and irradiation sections are arranged alternately along the transport path. The transport path leads in particular from a first application section to a first irradiation section, from the first irradiation section to the second application section up to, with possible further irradiation sections and application sections, to a last irradiation section. The irradiation sections and application sections are arranged in particular along a linear and / or straight transport path. The transport unit connects the plurality of application sections with the plurality of irradiation sections.

It is particularly preferred that at least one application section is arranged between each two irradiation sections. Alternatively, it can be provided that an irradiation section is followed by a further irradiation section, for example in order to further process, melt and / or structure the powder layer by means of a further laser beam, for example with a different wavelength or power.

It is particularly preferred that the system has a first application device for applying the powder layer with a first material powder and a second application device for applying the powder layer in a second application section with a second material powder. In particular the system can be designed so that different material powders are used in the first application section and in a second application section. The first material powder and the second material powder have different physical properties, chemical properties and / or compositions. This embodiment is based on the idea of providing a system in which a component can be produced from different powder layers, in particular material powders, the different material powders being applied to different application sections which are spaced from one another over the transport path. In particular, mixing of the material powders can thus be avoided.

In particular, the component forms a multilayer component comprising a number of layers. The number of layers corresponds in particular to the number of powder layers that are necessary to build up the component.

The number of layers is preferably greater than two and in particular greater than five. Furthermore, it is preferably provided that the number of layers is less than twenty. Optionally, the system has a number of irradiation sections and / or application sections which is equal to the number of layers of the component. This refinement is based on the consideration of providing a production system in such a way that all layers required to build up the component can be and / or generated in one line.

One embodiment of the invention provides that the construction platform is encompassed by the transport unit and / or the construction platform forms the transport unit. For example, for this purpose the construction platform is connected by means of a mechanism, for example a linkage or ropes, in such a way that they can be displaced, moved and / or moved in the plant room. In particular, the construction platforms that are included in the transport unit are reusable construction platforms that can be used again after a component has been built

Structure of a new further component can be used. For example, after the component has been successfully assembled, a construction platform is provided again and / or used at the start of the transport route. It is particularly preferred that the transport unit and / or the construction platform form a conveyor belt. For example, the construction platform forms a metal strip on which the powder layers are applied and the component is built on it. The construction platform and / or the conveyor belt thus in particular form an endless belt which is arranged in a loop and / or closed. It is particularly preferred that the construction platform is designed for direct application and / or construction of the component on it. For example, the construction platform and / or the conveyor belt forms a base material and / or a base layer of the component. For example, the built-up component can then be punched out of the building platform and / or the conveyor belt and / or separated therefrom.

The system preferably has a processing chamber. The processing chamber is formed, for example, by the housing of the system. In particular, the plant room is arranged within the processing chamber. For example, it is provided that at least and / or all of the irradiation sections are arranged in the processing chamber. Furthermore, it is preferably provided that at least one or all application sections are arranged in the processing chamber. In particular, it is provided that a protective gas atmosphere prevails inside the processing chamber. For example, the system has an atmosphere supply device for this purpose, which supplies and / or discharges protective gas. In particular, the processing chamber forms a barrier for the protective gas atmosphere with respect to the surroundings and / or the atmosphere. It is preferably provided that the transport route and / or the entire transport route is arranged within the processing chamber.

One embodiment of the invention provides that the processing chamber has an entry lock section and an exit lock section. The transport path preferably extends from the entrance lock section to the exit lock section. The entry lock section and / or the exit lock section is designed, for example, as a slot in the housing and / or the processing chamber. The height of the slot is preferably dimensioned so that the construction platform can enter the transport unit at the entrance lock section and at the Exit lock section the component can exit. The entry lock section and the exit lock section serve to open the processing chamber to the environment, while at the same time maintaining a protective gas atmosphere. For example, there is a protective gas overpressure in the processing chamber, so that the inlet lock section and exit lock section serve to discharge the overpressure and / or the protective gas, so that the protective gas atmosphere always prevails inside the processing chamber.

It is particularly preferred that the system has at least one de-powdering unit. The de-powdering unit is designed, for example, as a suction unit or as a magnetization unit or unit for generating an electric field. The powder removal unit is preferably arranged after an irradiation section. By means of the powder removal unit, powder that has not been melted and / or not used can be removed and / or sucked off. In particular, it can be provided that instead of and / or in addition to suctioning off the powder in the case of metallic and / or other powders, the removal can take place by electrical charging and / or separation and by magnetization. This embodiment is based on the idea of providing a resource-saving system so that, for example, the pulverulent material powder that was not used can be reused and used later.

It is optionally provided that the powder removal unit is arranged between application sections in which different

Material powders or material powders are used.

For example, a first material powder is used in a first application section and a different material powder is used in the second application section, after the irradiation section for the first material powder the de-powdering unit sucks off the unused first material powder and only then does the further material powder apply. This refinement is based on the consideration of being able to avoid mixing the types of material powder when changing the material powder within the system, so that each material powder can in particular continue to be used and / or recycled. It is particularly preferred that the transport unit is designed to carry out the transport of the construction platform continuously. For example, the construction platform is continuously conveyed at a constant speed along the transport path. This refinement is based on the idea of enabling continuous processing and / or thus being able to avoid shifting, slipping and / or smearing of the powder layer. Alternatively, it is provided that the transport unit is designed to transport the construction platform discontinuously, for example step by step. For example, the construction platform is transported along a given translation path with a given and / or adjustable length.

It is optionally provided that the component forms a flat component, the system forming a system for producing a flat component. In particular, the system is designed and / or set up so that the exit lock section and / or the entry lock section are set up on flat components. Examples of flat components are, for example, components with fewer than ten layers and / or with a height of less than five centimeters. In particular, it is provided that the component forms a structural component, a surface and / or a heat sink.

It is particularly preferred that the component forms a bipolar plate and / or a flow field for a fuel cell. For example, the component is a bipolar plate for PEM fuel cells. For example, flow fields and / or bipolar plates for PEM fuel cells have five to ten layers. One consideration here is to be able to produce, for example, fuel cell parts and / or bipolar plates in a system with a cycle time of one to two seconds per bipolar plate.

Another subject matter of the invention is a method for manufacturing a component in a generative manufacturing process. In particular, the method is carried out with the system as described above. To manufacture the component, a powder layer is applied to a building platform and the powder layer is then selectively irradiated. In the method it is provided that the powder application is spatially separated and / or at a distance from the irradiation. For this purpose, for example, the construction platform is transported from an application section to an irradiation section. According to the method, provision is made, for example, to spatially separate the powder application and the exposure, so that a shortened processing time is possible.

Further advantages, effects and configurations emerge from the attached figures and their description. Show:

FIG. 1 shows an exemplary embodiment of a system for the additive manufacturing of a component;

FIG. 2 shows a further exemplary embodiment of a system for the additive manufacturing of a component;

FIG. 3 shows a third embodiment of a system for the additive manufacturing of a component.

FIG. 1 shows schematically a first exemplary embodiment of a system 1 for the additive manufacturing of a component 2. The system is designed as a system for carrying out a powder-bed-based manufacturing process and / or additive manufacturing process. For example, the system 1 is designed as a system for selective laser melting. The system 1 is designed here as a system such as a production system for the linear conveyance and / or manufacture of the component 2. The component 2 here preferably forms a flat component which is made up of a plurality of layers. The layers can have the same or a different material composition. The component 2 forms a 3D component which, in particular, has three-dimensional structures. For example, the component 2 forms a bipolar plate for a fuel cell.

The system 1 has a housing 3 which defines a processing chamber. The housing defines a plant space 4 which is located inside the housing 3. The housing 3 has an entry lock section 5 and an exit lock section 6. The entry lock section 5 and the exit lock section 6 are designed as openings in the housing 3, and are preferably designed as slots. The dimensioning of the exit lock opening 6 is selected in particular so that the height of the slot is greater than the height of the component 2 to be produced, but preferably has a lower height than twice the height of the component 2.

The system 1 has a transport unit 7. The transport unit 7 is designed as a conveyor belt. The conveyor belt is conveyed by a conveyor device 8. The actual conveyor belt is preferably conveyed continuously at a uniform speed. The conveyor belt and / or the transport unit 7 extends in particular from the entrance lock section 5 to the exit lock section 6. A protective gas atmosphere is located in the housing 3 and thus in the plant room 4. To do this, a

Protective gas generating device regularly supplied protective gas 9 so that a continuous protective gas atmosphere prevails in the processing chamber and / or in the plant room. In particular, the protective gas atmosphere and / or the supply of protective gas 9 is selected in such a way that there is an overpressure so that the protective gas escapes slightly at the inlet lock section 5 and the outlet lock section 6.

The system 1 comprises three application devices 10, which are arranged in the system room 4 and are located along the transport route. The transport path is defined and / or fixed by the transport unit 7 and in particular by the conveyor belt. The transport path extends from the entrance lock section 5 to the exit lock section 6. The application devices 10 are designed to apply a material powder as a powder layer to the transport unit and in particular to a construction platform 11. The building platforms are, for example, metal, plastic or ceramic plates that serve as a construction base for component 2. The building platforms 11 are arranged on the conveyor belt and are transported by the transport unit 7 along the transport path. The application devices 10 each apply a powder layer 12. The first application device 10 on the transport route applies the powder layer to the construction platform, which Subsequent application devices 10 apply the powder layer to a previous powder layer and optionally to a melted powder layer. The height profile of the powder layers increases from the entry lock section to the exit lock section with each application device 10, in particular these are arranged in a stepped manner in the height profile. For example, the material powder is applied continuously with the application devices 10, for example when the construction platforms 2 are continuously conveyed by the transport unit 7 at a constant speed.

The system 1 has an irradiation unit 13. The irradiation unit 13 is designed here as a laser which emits a main laser beam 14. The laser beam 14 is guided at least in sections within the housing 3 and / or in the plant room 4. The system 1 has a scanner device 15 which is designed to subdivide the laser beam 15 into partial laser beams 16. The partial laser beams, also just called laser beams for short, are directed into irradiation sections 17. In particular, the irradiation sections 17 are each located after an application section. In the irradiation section 17, the powder layer 12 is selectively melted by the laser beam 16. The melted powder is then cooled and allowed to solidify. The next powder layer is applied to the cooled and / or solidified sections as well as the non-melted powder layer in a subsequent application device 10 and then irradiated and / or melted in the next irradiation section 17. By arranging the application sections and irradiation sections 17 one after the other and using several irradiation sections and / or several application sections, the component 2 can be processed and / or manufactured more quickly.

The system 1 comprises a powder removal unit 18. The powder removal unit 18 is arranged in the housing 3. In particular, the powder removal unit 18 is arranged along the transport path after the last irradiation section 17. The powder removal unit 18 is designed to suck up unused, melted and / or recyclable material powder. The component 2 is thus exposed and / or cleaned the suction and / or removal of the application powder by means of the powder removal unit 18 recycling of the material powder, which can be returned to the application devices 10.

FIG. 2 shows a further embodiment of the system 1. The system 1 is designed essentially the same as the system 1 from FIG. The system 1 in FIG. 2 essentially differs in that the construction platform 11 serves directly as a conveyor belt for the transport unit 7. A base sheet is conveyed as a construction platform 12 directly along the transport route. The base sheet 2 is guided through the application devices 10, the powder layer being applied by the first application device 10 directly to the conveyor belt, here the base sheet. In the irradiation section 17 after the first application device 10, the powder layer is melted. In particular, the melted powder layer partially connects to the base sheet and thus to the building platform 12. The base sheet then forms part of the component 2 to be produced. The subsequent application of further powder layers and further melting takes place on the powder layers already applied and / or melted sections. After the last melting section, the component 2 is de-powdered with the de-powdering unit 18. The component 2 is then guided out of the processing chamber along the transport path. After powder removal and removal, the component 2 is separated from the base sheet or from the building platform. For example, the component 2 is punched out, cut out or otherwise separated for this purpose. In particular, the separating, cutting out and / or punching out takes place in such a way that part of the base sheet or the construction platform remains part of the component 2. This refinement is based on the idea of conveying the building platform directly, for example by driving it with motors, a pulling or pushing device. This saves a separate conveyor belt and wear and tear on it. In particular, the base sheet can be provided as an endless material and the components can then be obtained by singling and / or punching / cutting out.

FIG. 3 shows a third embodiment of a system 1 for the additive manufacturing of a component 2. The system 1 in FIG. 3 is essentially similar to FIG the other two embodiments from Figures 2 and 1 formed. An essential difference from the previous embodiments is that the application devices 10a, 10b and 10c are designed to apply a different material powder. The first application device 10a thus applies a first material powder as a powder layer. This powder layer is melted in the irradiation section. After this irradiation, the first material powder that is not used is suctioned off with the powder removal unit 18a. The powder removal unit 18a removes the material powder that has not been used and can thus be returned to the application device 10a by type. A second material powder is applied to the de-powdered section with the application device 10b after the de-powdering unit 18a. The second material powder differs in its composition and / or in its physicochemical properties from the material powder that was used previously. The powder layer of the second material powder applied in this way is melted, in particular selectively melted, in a subsequent irradiation. After melting and, if necessary, cooling, unused second material powder is removed from the powder removal unit 18b. The material powder removed with the powder removal unit 18b is again sorted and can be returned to the application device 10b. In a subsequent application device 10c, a third material powder is applied as a powder layer. The composition and / or the physicochemical properties of the third material powder are in particular different from those of the second material powder. The applied powder layer of the third material powder is then also selectively melted and / or irradiated. Unused third material powder is removed with the de-powdering unit 18c. The removed third material powder can be returned from the de-powdering unit 18c of the application device 10c.

This embodiment is based on the idea of being able to produce components with multiple layers generatively, the layers having different material compositions and / or properties. By arranging application devices 10a, 10b and 10c one after the other, a powder and / or material change can be saved and the process can be continuous be guided. By suctioning off unused powder after each melting, a sorted reuse of the powder can be guaranteed.

Claims

Expectations

1. Plant (1) for additive manufacturing of a component (2) from one

Material powder, with a building platform (11) for building up the component (2), with at least one application section for applying a powder layer (12) to the building platform (11), with at least one irradiation section (17) for selectively irradiating the powder layer (12), characterized by a transport unit (7), wherein the transport unit (7) is designed to move and / or move the construction platform (11) in a plant room (4) along a transport path, the

Application section and the irradiation section (13) along the

Transport path are spaced and / or adjacent.

2. Plant (1) according to claim 1, characterized by a plurality of

Application sections and a plurality of irradiation sections (13), the application section and the irradiation sections (13) being spaced apart along the transport path.

3. Plant (1) according to claim 2, characterized in that at least one application section is arranged between two irradiation sections (13).

4. Plant (1) according to one of the preceding claims, characterized by a first application device (10, 10a, 10b) for applying a first material powder in a first of the application sections and a second application device (10, 10b, 10c) for applying a second Material powder in a second of the application sections, with the first and second material powder being designed and / or composed differently.

5. Plant (1) according to one of the preceding claims, characterized in that the component (2) forms a multilayer component and is made up of a number of layers, the plant (1) having at least one

Number of layers of irradiation sections (13) and / or at least a number of layers of application sections.

6. Plant (1) according to one of the preceding claims, characterized in that the construction platform (11) is surrounded by the transport unit (7) and / or the construction platform (11) forms the transport unit (7).

7. Plant (1) according to one of the preceding claims, characterized in that the transport unit (7) and / or the construction platform (11) forms a conveyor belt.

8. Plant (1) according to one of the preceding claims, characterized by a processing chamber, wherein at least one of the irradiation sections (13) and at least one of the application sections are arranged in the processing chamber.

9. Plant (1) according to claim 8, characterized in that the

Processing chamber an entry lock section (9) and a

Having exit lock section (10), the transport path leading from the entry lock section (9) to the exit lock section (10).

10. Plant (1) according to one of the preceding claims, characterized by at least one de-powdering unit (18, 18a-c) for removing

unused material powder.

11. Plant (1) according to claim 10, characterized in that the

Powder removal unit (18, 18a-c) is arranged between two application sections for changing materials.

12. Plant (1) according to one of the preceding claims, characterized in that the transport unit (7) is designed to move the construction platform (11) continuously and / or to move it at a constant speed.

13. Plant (1) according to one of the preceding claims, characterized in that the component (2) forms a flat component.

14. Plant (1) according to one of the preceding claims, characterized in that the component (2) forms a bipolar plate.

15. A method for producing a component (2), in particular with the system (1) according to one of the preceding claims, wherein a powder layer (12) is applied to a building platform (11), the powder layer (12) then being selectively irradiated, whereby the application of the powder layer and the irradiation of the powder layer (12) take place spatially separately.