DE102017122088A1 - Additive manufacturing process - Google Patents

Abstract

The present invention relates to an additive manufacturing method for manufacturing a component, the method comprising the following method steps: a) providing a raw material (16), b) feeding the raw material (16) to a nozzle (22), c) melting the raw material ( 16) in front of the nozzle (22) or in the nozzle (22), d) discharging the molten raw material (16) from the nozzle (22) onto a support (26), wherein e) the raw material (16) is multilayered onto the support (16) Carrier (26) is applied to build the component; characterized in thatf) a lower layer (32) of raw material (16) is applied to the carrier (26); andg) heating the raw material (16) of the lower layer (32) such that it is at least partially melted; andh) an upper layer (32) of raw material (16) is applied to the lower layer (32), wherein process step h) occurs before, during or after process step g).

Description

The present invention relates to an additive manufacturing process. In particular, the present invention relates to a melt-layer method or a strand-laying method, by means of which components having a particularly high density can be produced in a simple manner. The present invention further relates to an arrangement for an additive manufacturing method.

Melt-screening processes are widely known as additive manufacturing processes. Such methods are also known as fused filament fabrication (FFF). Another similar method is the strand deposition method. Such methods are used for example in the manufacture or printing of prototypes, but are in principle also suitable for series production. So far, however, the production of components having a high density is problematic with such methods.

Basically, in melt-layer processes or strand-laying processes, individual strands of a raw material melted in a nozzle are placed on a platform or on or next to already deposited material. From the individual deposited strands of the material, a layer is formed. The component is composed of several layers. The production of dense components in this process is done so far by a downstream process step, wherein components are exposed to an acetone vapor. Thereby, an improved connection of the individual strands should be made one above the other. The better connection is based on a chemical process and is limited to certain materials.

Such known from the prior art solutions may therefore have further potential for improvement, in particular with regard to the formation of dense or high-density components.

It is the object of the present invention to at least partially overcome the disadvantages known from the prior art. In particular, it is the object of the present invention to provide a solution by which an additive manufacturing process, in particular a melt-layer process or a strand-laying process, is improved in such a way that the components produced have an improved density in a simple manner.

The object is achieved according to the invention by an additive manufacturing method with the features of claim 1 and by an arrangement for an additive manufacturing method having the features of claim 9. Preferred embodiments of the invention are described in the subclaims, in the description or the figures, wherein further in the subclaims or in the description or the figures described or shown features individually or in any combination may form an object of the invention, if the context does not clearly indicate otherwise.

1. a) Bereitstellen eines Rohmaterials;
2. b) Führen des Rohmaterials zu einer Düse;
3. c) Aufschmelzen des Rohmaterials vor der Düse oder in der Düse;
4. d) Ausbringen des geschmolzenen Rohmaterials aus der Düse auf einen Träger, wobei;
5. e) das Rohmaterial mehrschichtig auf den Träger aufgebracht wird zum Aufbauen des Bauteils; wobei
6. f) eine untere Schicht aus Rohmaterial auf den Träger aufgebracht wird; und
7. g) das Rohmaterial der unteren Schicht derart erhitzt wird, dass dieses zumindest teilweise geschmolzen wird; und
8. h) eine obere Schicht aus Rohmaterial auf die untere Schicht aufgebracht wird, wobei Verfahrensschritt h) erfolgt vor, während oder nach Verfahrensschritt g).

It is proposed an additive manufacturing method for manufacturing a component, the method comprising the following method steps:

1. a) providing a raw material;
2. b) feeding the raw material to a nozzle;
3. c) melting the raw material in front of the nozzle or in the nozzle;
4. d) discharging the molten raw material from the nozzle onto a carrier, wherein;
5. e) the raw material is applied to the carrier in a multi-layered manner for constructing the component; in which
6. f) a lower layer of raw material is applied to the carrier; and
7. g) the raw material of the lower layer is heated so that it is at least partially melted; and
8. h) an upper layer of raw material is applied to the lower layer, wherein process step h) takes place before, during or after process step g).

In particular, by such a method can be easily achieved a component with an improved density.

The method described above is thus an additive method for manufacturing a component. The components to be produced are not fundamentally limited and may in principle comprise any components. Examples include components that are intended for the management and management of liquid media, such as thermal management modules, as they have high demands on the tightness. Furthermore, the additive manufacturing method may be, in particular, a melt-layer method or a strand-laying method.

In this context, an additive or additive manufacturing process can be understood as meaning, in particular, a process in which a component is built up in layers on the basis of digital 3D design data by depositing or constructing material. An additive manufacturing process is different clearly from conventional, erosive manufacturing methods. Instead of, for example, milling a workpiece out of a solid block, as is known in the case of removing methods, the components are built up in additive manufacturing processes, in particular layer by layer, from materials or raw materials which are present as starting material in the method described here.

Using an additive method offers the particular advantage that the component can be produced in a simple manufacturing step without joints. As a result, simple procedures can be implemented, which can reduce the manufacturing costs. Moreover, an additive process without increasing the manufacturing cost substantially allows any suitable structure, such as in particular size and geometry, which can further improve adaptability of the desired dimensions and geometry. It is also equally possible to form the component from a single material or from different materials.

Such methods are used, for example, in so-called rapid prototyping or in series production.

For example, the raw material may be present as a filament or as a fiber. In this case, can be spoken of a melt-layer process.

Thus, a melt-layer process is basically understood to mean a process in which individual strands of a material melted before or in a nozzle are placed on a platform or on or next to already deposited material. From the individual deposited strands of the material, a layer is formed. The component is composed of several layers.

Another possibility is that raw material is present as granules. In this case, we can speak of a strand deposition method. Again, a strand of molten raw material is deposited. In the strand laying process, the raw material is melted, in particular, in front of the die in an extruder or otherwise.

Accordingly, the melt-layer process described here comprises the following process steps.

First, according to process step a), the provision of a raw material which may be formed as a filament or granules or may have the form of a filament or granules. Under a raw material is to be understood in particular the material from which the component is to be formed. By way of example, in particular plastics, predominantly thermoplastics, such as acrylonitrile-butadiene-styrene copolymers (ABS) or polylactides (PLA), but without being limited to this embodiment. Furthermore, a filament is to be understood in a manner known per se as a raw material which is present in the form of fibers or in the form of wires, and may be rolled up on a roll or roller, for example. Granules are characterized by the presence of the material in small units, such as pellets.

Furthermore, the method according to method step b) comprises feeding the raw material to a nozzle. In this method step, the raw material provided in method step a) is thus guided or transported to a nozzle, so that a discharge of the raw material, from which, for example, the filament or granulate is constructed, can be realized by the nozzle. The exact implementation of this step is not fundamentally limited. For example, the raw material may be fed to the nozzle and rolled off about a roll.

Correspondingly, method step c) comprises the melting of the raw material in front of the nozzle or in the nozzle. For example, this can be done in particular for a filament through a heated nozzle, which can realize a particularly simple procedure and also safely allow a melting of the raw material. For example, the nozzle may be an extruder die, wherein the raw material, in particular in the form of granules, can be melted. Thereby, the raw material in at least partially, in particular completely, molten state according to process step d) are discharged from the nozzle and applied to a carrier. Thus, as indicated above, it is provided in particular to at least partially, for example completely melt, a raw material present as a filament before it is introduced into the nozzle or to at least partially melt, for example completely, a raw material present in the form of granules in front of the nozzle.

Furthermore, it is provided according to method step e) that the raw material is applied to the carrier in a multi-layered manner for constructing the component. This is a central component of the additive process. Because of a multi-layer structure, it can be made possible in particular by different surface application in different layers that the desired component is reproduced or formed exactly. The layer sequence or the different surface application can be based on three-dimensional product data, as is basically known for additive manufacturing processes.

In the additive manufacturing method described here, it is further provided that, according to method step f), a lower layer of the raw material is applied to the carrier and according to method step g) the raw material of the lower layer is heated so that it is at least partially melted. Thus, the material applied as a lower layer is first cooled or may at least partially solidify and is subsequently melted again at least partially. According to method step h), an upper layer is applied to the lower layer before, during or after method step g). In particular, this embodiment can offer significant advantages over the solutions of the prior art.

A lower layer is applied, whereupon an upper layer is applied. The terms lower layer and upper layer should be understood to mean, in particular relative to each other, but not to limit any absolute positioning in a plurality of layers or layers.

The lower layer or the material thereof is treated or heated so that it is at least partially melted, which can be realized before, during or after the application of the upper layer. This can be realized in particular but not exclusively by an additional heating means, that is, by a heating means used for the first melting of the raw material before application to the carrier additional heating means.

The heating means or additional energy source to be introduced in addition to the heating means which are generally present should thus be designed such that it heats the already deposited material in a defined area. The heating should be such that the already deposited and optionally solidified material melts again easily. This makes it possible that a better connection between already stored solidified and newly deposited material, ie between the lower and upper layer, can take place. The resulting improved connection between individual tracks and layers leads to significantly denser components. This is much more efficient than is the case in the prior art.

The comparatively less pronounced density of the components produced according to the prior art results from the fact that always newly molten material is deposited on or next to already solidified material. The already solidified track is melted only superficially by the newly deposited material. The individual tracks or layers are thus only superficially connected to each other and form no dense component. However, this connection problem of individual layers can be improved with the method described here.

So far, an improvement in the density by an additional process step, namely a post-treatment with acetone allows. However, this additional step is limited to certain sufficiently durable materials. Advantage of the method described here is that this is in principle conceivable in all thermally fusible materials and is not limited to a few materials which resist an acetone treatment. Furthermore, a process step can be saved, which is also of significant advantage.

Another advantage of the improved attachment is the reduction in anisotropy, which may benefit the material properties for some applications.

The use is conceivable for components that have requirements for the tightness of components, such as thermal management modules. The resulting improved isotropy is generally advantageous for all components produced by this method, such as prototypes.

It may be preferred that process step h), after which an upper layer is applied to a lower layer, takes place before process step g), after which the raw material of the lower layer is heated such that it is at least partially melted. In this embodiment, it can be provided that the introduction of additional energy for better fusion of the deposited webs takes place only after completion of an entire layer. In this case, for example, after each layer, a laser could expose the entire layer and merge the deposited tracks. Also in this embodiment, dense components can be produced and excellent adhesion of the layers to each other can be realized.

However, it is particularly preferred that process step h), after which an upper layer is applied to the lower layer, after process step g), after which the raw material of the lower layer is heated so that it is at least partially melted, takes place. In this embodiment, therefore, a lower layer, which is still present on the surface, are melted, so that the subsequent applied layer can be firmly connected to the lower, at least partially melted layer. This configuration can be particularly simple to carry out in terms of process technology, since only an upper layer and in particular the exposed surface needs to be melted. The process parameters to be used for this purpose are basically easy to set. In addition, the method can be configured particularly energy-saving in this embodiment.

Furthermore, it may be preferred that process step g) takes place using an active heating means. In this embodiment, a heating means is thus used, which actively discharges heat and the temperature directed specifically to the heated position of the lower layer. For example, the heating means may be an additional heating means, which is provided in addition to the heating means, which melts the configured approximately as filament or granules raw material. Thus, the heating means is not, for example, the hot applied upper layer, but rather a separately controllable component. This allows a particularly efficient and targeted and defined heat input to be heated to the position to be heated. As a result, it can be ensured that the position to be heated is heated sufficiently that fusion takes place, but at the same time, the entire assembly is not melted. Thus, in this embodiment, by ensuring a desired reflow, the production of a defined product can be enabled.

With respect to the active heating means, it may be particularly preferable to use a laser as such. In particular, using a laser, the heating of the lower layer can be made possible both before application of the upper layer, and after application of the upper layer, as described above. Because by a laser, a particularly defined and precise point entry of heat is possible, so that the melting of the lower layer can run in a particularly defined. In this case, the melting of the lower layer can be easily possible if the upper layer is already present, since the energy input is controlled by a laser particularly defined. In principle, it is possible, in particular by means of a laser, to obtain clean and narrow melting regions through a locally limited heat-affected zone, so that the structure of the component to be produced is not adversely affected by the additional melting. Furthermore, the method is particularly adaptable in this embodiment.

Particularly preferably, it may be provided that heating of the lower layer or method step g) takes place using scanner welding. In scanner welding, the laser beam is guided, in particular, by means of movable mirrors. By adjusting the mirror, in particular via corresponding changes in the angle of the mirror, the laser beam can be performed highly accurate. Thus, an edit field can arise in which highly dynamic and precise melting can be made possible. The size of the heat-affected area can be adjusted in a simple manner by the working distance and deflection angle. As a result, the method described above is particularly adaptable, in particular in this embodiment, so that the most varied products can be formed by a device, which is advantageous in particular in the case of an additive method.

With regard to further technical features and advantages of the additive method, reference is made to the description of the arrangement, the figures and the description of the figures.

The present invention further provides an assembly for an additive manufacturing method, comprising a device for providing a raw material and having a nozzle, wherein a raw material provided by the device can be brought to the nozzle, and wherein the raw material from the nozzle in at least partially melted state can be applied, wherein the arrangement further comprises a carrier, on which the raw material from the nozzle can be applied, wherein the arrangement further comprises a heating means by which the material applied to the carrier is heated so that it is at least partially melted.

With this configuration, it can be advantageously made possible that an already applied to a support and optionally already hardened material is reheated and at least partially melted. Thereby, adhesion of an upper layer to a lower layer can be improved, and further, a material having a particularly high density can be produced.

In particular, the heating means by which the material applied to the carrier can be heated may be a second heating means and in addition to the heating means, the raw material may be heated prior to application to the carrier, which may be configured as a heated nozzle, for example. In particular, this second heating means can act locally and / or be configured as a laser. For example, the second heating means may be provided in or on the print head.

Examples of a laser as a second heating means include, for example, a CO ₂ laser, an Nd: YAG laser, a fiber laser or a diode laser.

Particularly preferably, it can be provided that a movable mirror is provided for deflecting a laser beam emitted by the laser beam. In this embodiment, the arrangement may be suitable for scanner welding. As a result, the heating device or the laser can be arranged stationary, even if the nozzle moves approximately for application of the raw material, which may allow improved long-term stability. In addition, such a very accurate heating of the lower layer can be done, whereby even the finest components can be designed highly defined.

For example, this arrangement and accordingly also the method described above can be used in the manufacture of components for a thermal management module.

With regard to further technical features and advantages of the arrangement, reference is made to the description of the method, the figures and the description of the figures.

• 1; eine schematische Darstellung einer Anordnung zum Durchführen eines Schmelzschichtverfahrens als additives Verfahren.

In the following, a particularly preferred embodiment of the invention will be explained with reference to the accompanying drawings, wherein it is explicitly pointed out that the object according to the invention is not limited to the exemplary embodiment described. It shows:

• 1 ; a schematic representation of an arrangement for performing a melt layer process as an additive method.

In the 1 is an arrangement 10 which is suitable for a melt layer process as an additive manufacturing process.

The order 10 includes a device 12 for providing a raw material formed as filament 14 16 , The device 12 can be about two particular rotatable rollers 18 include the filament 14 or the raw material 16 which as a role 20 rolled up, promotes and to a particular horizontally movable nozzle 22 leads. The nozzle 22 can be heated about and the raw material 16 so melt and melt 24 deliver.

Furthermore, it may be possible to melt the raw material from a granulate to the nozzle 22 to promote, say, if the nozzle 22 is an extruder die. The procedure described below is then appropriate.

Discharged from the nozzle 22 can the raw material 16 on a carrier 26 be applied. The carrier 26 For example, an edition 28 exhibit on one foot 30 is arranged. In particular, the edition 28 be adjustable in height, for example by an adjustable length of the foot 30 , so by applying raw material 16 on the carrier 26 or on the edition 28 a component can be built up additive by the nozzle 22 , together with a housing 34 in which the nozzle 22 for better temperature control can be arranged, is moved horizontally and the support 28 is moved in height. This is the raw material 16 or the melt 24 in several layers 32 applied. In particular, in the 1 a lower layer 32 ₁ and an upper layer 32 ₂ shown.

It is further shown that the arrangement 10 Further, a heating means 36 through which the on the carrier 26 applied raw material 16 or on the carrier 26 applied lower layer 32 ₁ is heated so that this or this is at least partially melted. In the 1 In this case, an embodiment is shown in which the nozzle 22 and the heating medium 36 work that way, that the lower layer 32 ₁ from the heating medium 36 is heated before the upper layer 32 _{2 is} applied.

According to 1 is the heating medium 36 as a laser 38 configured, which is suitable for a scanner welding. Accordingly, a movable mirror 40 provided by the laser 38 emitted laser beam 42 reflect and steer to the desired position. Although also the heating medium 36 can be arranged in the housing 34 or can basically and independently of the specific embodiment, the heating means with the nozzle 22 are moved, however, it is possible by the provision of a scanner welding process, the heating means 36 static or immovable execute and still any suitable position on the carrier 24 or the lower layer 32 ₁ to treat.

1. a) Bereitstellen des Rohmaterials 16;
2. b) Führen des Rohmaterials 16 zu der Düse 22;
3. c) Aufschmelzen des Rohmaterials 16 vor der Düse 22 oder in der Düse 22;
4. d) Ausbringen des geschmolzenen Rohmaterials 16 als Schmelze 24 aus der Düse 22 auf einen Träger 26, wobei;
5. e) das Rohmaterial 16 beziehungsweise die Schmelze 24 mehrschichtig auf den Träger 26 aufgebracht wird zum Aufbauen des Bauteils; wobei
6. f) die untere Schicht 32₁ aus Rohmaterial 16 auf den Träger 26 aufgebracht wird;
7. g) das Rohmaterial 16 der unteren Schicht 32₁ derart erhitzt wird, dass dieses zumindest teilweise geschmolzen wird; und
8. h) die obere Schicht 32₂ aus Rohmaterial 16 auf die untere Schicht 32₁ aufgebracht wird, vor, während oder nach Verfahrensschritt g).

Thus, by the described arrangement 10 an additive method for manufacturing a component with the following method steps possible:

1. a) Providing the raw material 16 ;
2. b) guiding the raw material 16 to the nozzle 22 ;
3. c) melting of the raw material 16 in front of the nozzle 22 or in the nozzle 22 ;
4. d) discharging the molten raw material 16 as a melt 24 from the nozzle 22 on a carrier 26 , in which;
5. e) the raw material 16 or the melt 24 multilayered on the carrier 26 is applied to build the component; in which
6. f) the lower layer 32 ₁ from raw material 16 on the carrier 26 is applied;
7. g) the raw material 16 the lower layer 32 ₁ is heated so that it is at least partially melted; and
8. h) the upper layer 32 ₂ from raw material 16 on the lower layer 32 ₁ is applied before, during or after process step g).

LIST OF REFERENCE NUMBERS

10

arrangement

12

contraption

14

filament

16

raw material

18

roller

20

role

22

jet

24

melt

26

carrier

28

edition

30

foot

32

layer

32 ₁

Lower class

32 ₂

upper layer

34

casing

36

heating

38

laser

40

mirror

42

laser beam

Claims (10)

An additive manufacturing method for manufacturing a component, the method comprising the following method steps: a) providing a raw material (16); b) feeding the raw material (16) to a nozzle (22); c) melting the raw material (16) in front of the nozzle (22) or in the nozzle (22); d) discharging the molten raw material (16) from the nozzle (22) onto a support (26), wherein; e) the raw material (16) is applied in multiple layers to the support (26) for building up the component; characterized in that f) a lower layer (32 ₁ ) of raw material (16) is applied to the carrier (26); and g) heating the raw material (16) of the lower layer (32 ₁ ) such that it is at least partially melted; and h) an upper layer (32 ₂ ) of raw material (16) is applied to the lower layer (32 ₁ ), wherein i) method step h) takes place before, during or after method step g). Additive manufacturing method according to Claim 1 , characterized in that method step h) takes place before method step g). Additive manufacturing method according to Claim 1 , characterized in that method step h) takes place before method step g). Additive manufacturing method according to one of Claims 1 to 3 , characterized in that the nozzle (22) is heatable. Additive manufacturing method according to one of Claims 1 to 4 , characterized in that step g) takes place using an active heating means (36). Additive manufacturing method according to Claim 5 , characterized in that a laser (38) is used as the heating means (36). Additive manufacturing method according to Claim 6 , characterized in that method step g) is carried out using a scanner welding. An additive manufacturing process assembly comprising apparatus (12) for providing a raw material (16) and having a nozzle (22), a raw material (16) provided by the apparatus (12) being engageable with the nozzle (22), and the raw material (16) being ejectable from the nozzle (22) in an at least partially molten state, the assembly (10) further comprising a support (26) to which the raw material (16) can be applied by the nozzle (22). characterized in that the arrangement (10) further comprises a heating means (36) through which the on the carrier (26) applied raw material (16) is heated so that it is at least partially melted. Arrangement according to Claim 8 , characterized in that the heating means (36) is a laser (38). Arrangement according to Claim 9 , characterized in that a movable mirror (40) is provided for deflecting a laser beam (42) emitted by the laser (38).

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