Abstract
A method for the additive manufacture of a component within a receiving unit using a powdery material wherein, in one step, the powdery material is introduced into the receiving unit via a feed unit. In a further step, an oscillation is applied to the powdery material introduced into the receiving unit. In a further step, the oscillation is applied over a period of time to the powdery material introduced into the receiving unit until a predetermined distribution of the powdery material within the receiving unit is achieved. In a further step, at least a part of the powdery material within the receiving unit is solidified after the predetermined distribution of the powdery material has been achieved. An apparatus for the additive manufacture of a component within a receiving unit using a powdery material is also described.
Claims
1. A method for an additive manufacture of a component within a receiving unit using a powdery material, the method comprising: introducing the powdery material into the receiving unit via a feed unit; applying an oscillation to the powdery material introduced into the receiving unit; applying the oscillation over a period of time to the powdery material introduced into the receiving unit until a predetermined distribution of the powdery material within the receiving unit is achieved; and solidifying at least a part of the powdery material within the receiving unit after the predetermined distribution of the powdery material within the receiving unit has been achieved.
2. The method according to claim 1, wherein the predetermined distribution of the powdery material is a measure of a flatness of an exposed surface of the powdery material introduced into the receiving unit.
3. The method according to claim 1, wherein the predetermined distribution of the powdery material is a measure of a layer thickness distribution of the powdery material introduced into the receiving unit.
4. The method according to claim 1, further comprising: monitoring whether the powdery material within the receiving unit has achieved the predetermined distribution.
5. The method according to claim 1, further comprising: applying the oscillation to the powdery material introduced into the receiving unit during and/or immediately after the introduction of the powdery material into the receiving unit.
6. The method according to claim 1, wherein the predetermined distribution of the powdery material within the receiving unit is achieved without using mechanical contact smoothing in the region of an exposed surface of the powdery material introduced into the receiving unit.
7. The method according to claim 1, further comprising: applying the oscillation to the powdery material introduced into the receiving unit by an oscillation unit coupled to the receiving unit.
8. The method according to claim 1, further comprising: applying the oscillation to the powdery material introduced into the receiving unit by an acoustic output unit.
9. The method according to claim 1, further comprising: applying the oscillation to the powdery material introduced into the receiving unit by an oscillation element introduced at least partially into the powdery material.
10. The method according to claim 1, further comprising: fixing a solidified part of the powdery material within the receiving unit by a fixing unit.
11. The method according to claim 1, further comprising: introducing an insert volume into the receiving unit, wherein the insert volume is arranged in a first region within the receiving unit, the first region differing from a second region, in which the part of the powdery material to be solidified is arranged.
12. An apparatus for an additive manufacture of a component within a receiving unit using a powdery material, comprising: a feed unit configured to introduce the powdery material into the receiving unit; an oscillation unit configured to apply oscillation to the powdery material introduced into the receiving unit; a control unit configured to monitor a current distribution of the powdery material introduced into the receiving unit and to maintain the oscillation on the powdery material introduced into the receiving unit over a period of time until the current distribution of the powdery material within the receiving unit has achieved a predetermined distribution of the powdery material within the receiving unit; and a solidification unit configured to solidify at least a part of the powdery material within the receiving unit after the predetermined distribution of the powdery material within the receiving unit has been achieved.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1A shows an apparatus having an oscillation unit for distributing a powdery material according to one exemplary embodiment.
[0036] FIG. 1B shows an apparatus having an oscillation unit for distributing a powdery material according to another exemplary embodiment.
[0037] FIG. 2A shows an apparatus having an oscillation unit during feeding of powdery material according to one exemplary embodiment.
[0038] FIG. 2B shows an apparatus having an oscillation unit after feeding of powdery material according to one exemplary embodiment.
[0039] FIG. 2C shows an apparatus having an oscillation unit after distribution of a powdery material according to one exemplary embodiment.
[0040] FIG. 3 shows a manufacturing process in an apparatus for the additive manufacture of a component according to one exemplary embodiment.
[0041] FIG. 4 shows an apparatus having an acoustic output unit for distributing a powdery material according to one exemplary embodiment.
[0042] FIG. 5A shows a fixing device for fixing an additively manufactured component on a receiving unit according to one exemplary embodiment.
[0043] FIG. 5B shows a fixing device for fixing an additively manufactured component on a receiving unit according to another exemplary embodiment.
[0044] FIG. 5C shows a fixing device for fixing an additively manufactured component on a receiving unit according to another exemplary embodiment.
[0045] FIG. 5D shows a fixing device for fixing an additively manufactured component on a receiving unit according to another exemplary embodiment.
[0046] FIG. 5E shows a fixing device for fixing an additively manufactured component on a receiving unit according to another exemplary embodiment.
[0047] FIG. 5F shows a fixing device for fixing an additively manufactured component on a receiving unit according to another exemplary embodiment.
[0048] FIG. 6A shows an insert volume according to one exemplary embodiment arranged in a receiving unit.
[0049] FIG. 6B shows an insert volume according to another exemplary embodiment arranged in a receiving unit.
[0050] FIG. 6C shows an insert volume according to another exemplary embodiment arranged in a receiving unit.
[0051] FIG. 6D shows an insert volume according to another exemplary embodiment arranged in a receiving unit.
[0052] FIG. 7 shows a flow chart for a method for the additive manufacture of a component within a receiving unit using a powdery material according to one exemplary embodiment.
DETAILED DESCRIPTION
[0053] The illustrations in the figures are schematic and not to scale.
[0054] If the same reference signs are used in various figures in the following description of the figures, they designate identical or similar elements. However, identical or similar elements may also be designated by different reference signs.
[0055] FIGS. 1A and 1B show an apparatus 1 having an oscillation unit 20 for distributing a powdery material 14. The apparatus 1 is an apparatus 1 for the additive manufacture of a component 10 within a receiving unit 12 in the form of a powder bed 12 using the powdery material 14. The apparatus 1 comprises a feed unit 16, which introduces the powdery material 14 into the receiving unit 12 or feeds it to the latter. As illustrated, the feed unit 16 can be arranged above the receiving unit 12, such that the powdery material 14 falls from above into a collecting container of the receiving unit 12. The apparatus 1 also has an oscillation unit 20, which applies an oscillation to the powdery material 14 introduced into the receiving unit 12. The oscillation unit 20 has a drive motor 21, which transmits the oscillation directly to the receiving unit 12 in the form of a forward and backward movement or a vibration, with the result that ultimately oscillation or vibration is imparted to the powdery material 14. The receiving unit 12 can comprise a type of floating mounting, for example a spring mounting 13. The oscillation can take place in all spatial directions, can have a specific amplitude or deflection, can have a specific frequency and can take place over a predetermined period of time. These oscillation parameters are set or specified by means of a control unit 30. The control unit 30 can be part of the apparatus 1 and is designed to receive various input variables which serve as the basis for setting the said parameters. In particular, the control unit 30, which is designed to monitor a current distribution of the powdery material 14 introduced into the receiving unit 12 and to maintain the oscillation on the powdery material 14 introduced into the receiving unit 12 over a period of time until the current distribution of the powdery material 14 within the receiving unit 12 has achieved a predetermined distribution of the powdery material 14 within the receiving unit 12. The apparatus 1 also comprises a solidification unit 28, which is designed to solidify at least a part of the powdery material 14 within the receiving unit 12 after the predetermined distribution of the powdery material 14 within the receiving unit 12 has been achieved.
[0056] The component 10 is additively manufactured in the receiving unit 12, that is to say is generated in a three-dimensional printing process. This 3D printing takes place via a plurality of steps, wherein, in one step, the powdery material 14, that is to say the powder 14, is introduced into the receiving unit 12, the powder 14 is distributed in a subsequent step, and, in a further subsequent step, a part of the powder 14 is solidified by means of the solidification unit 28, for example by laser sintering. This sequence of steps can be repeated over a plurality of iterations, with the result that the component 10 is ultimately generated or printed in layers.
[0057] Here, the predetermined distribution of the powdery material 14 is a measure of a flatness of an exposed surface 18 of the powdery material 14 introduced into the receiving unit 12. As shown in FIGS. 1A and 1B, the exposed surface 18 forms the respective uppermost interface between the powdery material 14 and an ambient fluid in the apparatus 1.
[0058] FIG. 1B also shows a movement device 40, which can move a base plate 41 of the receiving unit 12 upwards or downwards. In the course of the manufacturing process, the base plate 41 can thus be lowered (indicated by arrow) in order to provide a further receiving space within the receiving unit 12 in the region of the exposed surface 18 of the powder 14, thus enabling further material layers to be fed in and solidified in order in this way to successively manufacture the component 10. The movement device 40 can also define a layer height of the powder material 14, thus enabling excess powder material 14 to be shaken, as it were, over the edge of the receiving unit 12, while in the case of exemplary embodiments without a movement device 40 (cf. for example FIG. 3 below) the material metering would have to be carried out with sufficient accuracy and a laser focus of the solidification unit 28, etc., would have to compensate for the difference in height.
[0059] FIGS. 2A, 2B and 2C show the apparatus 1 during a manufacturing process of the component 10. Here, part of the component 10 has already been manufactured. It can be seen in FIG. 2A that, in one step, the powdery material 14 is introduced into the receiving unit 12 via the feed unit 16, wherein individual material quantities 17 are poured onto powder 14 already located in the receiving unit 12. As illustrated, this results in local accumulations 19 of the powdery material 14, which lead to unevenness on the exposed surface 18. Powder material 14 falling over the edges of the receiving unit 12 can be collected and made available again to the feed unit 16.
[0060] In a further step, which is represented by FIG. 2B, the oscillation unit 20 introduces oscillations or vibrations into the powdery material 14, with the result that the accumulations 19 of the powdery material 14 at the exposed surface 18 are at least partially distributed and thus continuous levelling of the exposed surface 18 is achieved.
[0061] FIG. 2C now shows a state in which a predetermined distribution 50 of the powdery material 14 within the receiving unit 12 has already been achieved. The application of the oscillation to the powdery material 14 introduced into the receiving unit 12 thus takes place over a period of time until this predetermined distribution 50 of the powdery material 14 within the receiving unit 12 is achieved. The achievement of this predetermined distribution 50 is characterized in that only very small or no more accumulations 19 are present on the exposed surface 18. The predetermined distribution 50 is representative of a certain flatness of the exposed surface 18. That is to say that deviations from a plane forming the exposed surface 18 no longer exceed a specified threshold value. As mentioned above, a current distribution is monitored by the control unit 30 (cf. FIGS. 1A and 1B). In this case, monitoring is carried out as to whether the powdery material 14 within the receiving unit 12 has achieved the predetermined distribution 50. In other words, when the current distribution of the powder 14 has achieved the predetermined distribution 50 of the powder 14 on the exposed surface 18, then the application of oscillations by the oscillation unit 20 can be terminated and subsequently the solidification of a corresponding part of the powder 14 can be carried out by means of the solidification unit 28, as illustrated in FIG. 2C. The predetermined distribution 50 of the powdery material 14 within the receiving unit 12 can thus be achieved without using mechanical contact smoothing in the region of an exposed surface 18 of the powdery material 14 introduced into the receiving unit 12.
[0062] FIG. 3 shows a manufacturing step in the apparatus 1 for the additive manufacture of the component 10. As can be seen, the receiving unit 12 is not completely filled with powder 14. The component 10 is manufactured in layers. As illustrated, the solidification unit 28 is used for solidification here. In the case of laser sintering, a laser beam impinges on the regions of the exposed surface 18 to be solidified in order to generate the component 10. In this case, solidification does not take place until the predetermined distribution 50 has been achieved before each solidification step.
[0063] FIGS. 1A to 3 each show the oscillation unit 20, which is configured in the form of a table vibrator or vibrating table. Instead of using a table vibrator or vibrating table for the entire powder bed 12, a vibrating rod (or some other vibrating element) can be introduced into the powder 14 for a similar effect, with applicability potentially depending on the material used. The oscillation or vibration may also be introduced only into certain parts or certain regions of the powder bed 12, depending on the specific mechanics. For example, the oscillation may be introduced only into the base plate 41 (cf. FIG. 1B), directly via the base plate 41 or via its movement mechanisms. Means can be provided for preventing the propagation of the oscillations to other parts of the apparatus 1. Decoupling of the vibrating parts, such as the receiving unit 12, from the non-vibrating parts can be achieved, for example, by means of suitable springs and dampers, or by the implementation of a structure in which vibrating parts and non-vibrating parts are mounted independently of one another. For example, the housing which carries the material supply or the feed unit 16 and a power source (not illustrated), can be mounted on the floor and decoupled from the vibrating printing bed 12.
[0064] Alternatively, it is also possible to use sound waves to achieve the abovementioned distribution effect, the oscillations being introduced via the fluid medium surrounding the powder 14, or the fixed structure of the receiving unit 12 being excited by the sound waves. The powder 14 can be mixed with a liquid to produce a slurry and to improve sound transmission and behaviour under vibration.
[0065] FIG. 4 shows the apparatus 1 having an acoustic output unit 22 for distributing a powdery material 14 instead of the oscillation unit 20. Here, therefore, the application of the oscillation to the powdery material 14 introduced into the receiving unit 12 is accomplished by means of an acoustic output unit 22. However, the oscillation unit 20 can also be used in addition or in an auxiliary capacity, as illustrated in FIGS. 1A to 3. All other components of the apparatus 1 can be configured as described above.
[0066] In the above-described approaches for achieving the predetermined distribution 50 of the powder 14, the exciter frequency, amplitude and direction can be changed by means of a suitable construction, placement and/or mounting and control of the exciter unit or oscillation unit. This applies both to the mechanical excitation by, for example, a table vibrator, which is based on mass movement, and to excitation by pressure waves or sound waves, which are generated, for example, by way of a loudspeaker system, it being possible to modulate both approaches in such a way that they best correspond to the material used and the desired effect. The parameters used can be adapted not only to the material 14 used, but also to the shape of the receiving unit 12 in which it is distributed (e.g. types/forms of powder, size distribution, desired layer thicknesses, etc.). It is possible with the aid of a light barrier to ensure that no excess material remains above a certain level on the exposed surface 18. These approaches for distributing the powder 14 can be combined with mechanical contact smoothing solutions, such as roller smoothing, in order to make possible a two-stage powder distribution process in which the vibration step ensures that unevenness is eliminated and/or optimum compression of the powder 14 is achieved.
[0067] FIGS. 5A to 5F show various fixing devices 24 for fixing the additively manufactured component 10 on a receiving unit 12. In order to avoid a relative movement between the solidified or printed component 10 and the receiving unit 12 during the application of oscillations, fixing of the already printed component material 10 can be ensured by the fixing unit 24. In cases in which adhesion to a base plate 41 of the receiving unit 12 cannot be achieved, fixing can be achieved in various possible ways.
[0068] FIG. 5A shows a structured base plate 41 with structured elements 42 such as, for example, grooves or slots, which are provided on the base plate 41 of the receiving unit 12 and which can engage with complementary ribs on the component 10 in order to fix the component 10.
[0069] FIG. 5B shows needles 43 and/or pins 43 which extend into the desired build space of the receiving unit 12 and on which the already produced part of the component 10 can be fixed.
[0070] FIG. 5C shows a base plate extension 44 in the form of a template, which fixes the lower part(s) of the structure of the printed component 10. In this case, the base plate extension 44 in the form of a template forms a widened or thickened portion of the base plate 41, which, however, has cutouts in the region of the component 10 which is to be printed or has already been printed.
[0071] FIG. 5D shows lateral fixing pins 45 and/or needles 45, which can also be attached to the receiving unit 12 at higher layer levels at a distance from the base plate 41 in order to fix the printed component 10.
[0072] The possibilities mentioned can also be used in combination with a special support structure which is produced during the printing process.
[0073] Another possibility of keeping the printed component 10 connected to the base plate 41 during printing, in particular during the vibration phases, is illustrated in FIGS. 5E and 5F. In this case, the fixing unit 24 can have a prefabricated insert 46 or an inlay 46, which can be, for example, printed, cast, milled and is mounted on the printing base plate 41. Mounting can take place via any desired connection, for example positive or nonpositive as well as adhesive bonding, etc., which ensures that the structure 10 which is printed thereon has a good connection to the rigid parts of the receiving unit 12. The powder material 14 can be selected in such a way that printing of these inlays 46 with a good connection between the inlay 46 and the printed component 10 is ensured, and this can be achieved by a suitable choice of material.
[0074] FIGS. 6A to 6D each show an insert volume 26, which is arranged in the receiving unit 12, wherein the insert volume 26 is arranged in a first region within the receiving unit 12, which region differs from a second region, in which the part of the powdery material 14 to be solidified, i.e. the subsequent component 10, is arranged.
[0075] In other words, the apparatus 1 can be used to reduce the build volume in a simple way in order to save on powder material 14, for example if only a small or low partial quantity of the powder material 14 is printed or if the shape of the subsequent component 10 leads to large regions of the receiving unit 12 being virtually unused. For this purpose, a build volume enclosure in the form of the insert volume 26 can be used. The insert volume 26 can be regarded as a type of volume filler. This can be a plurality of modular insert volumes 26 with different sizes and shapes, as illustrated in FIG. 6D. This enables the build volume for the subsequent component 10 to be adapted in a flexible manner. Metal or plastic parts can be used as insert volumes 26, which can be produced by 3D printing, milling or similar methods and can be reused for various component versions. Both standard sizes for producing a specified smaller build volume, and sizes which are adapted to a specific print type and optimize the effective build volume in order to minimize powder consumption are possible. In scraping or roller systems for contact smoothing, these insert volumes 26 would collide with the corresponding mechanism. However, the oscillation application techniques disclosed herein render this problem obsolete.
[0076] Different types of shapes can be provided for the insert volume 26, and they can be combined with fixings, base plate adaptations, etc. (see FIGS. 5A to 5F). In one example, the oscillation unit 20 is installed or integrated into one of these insert volumes 26, or the oscillation can be coupled into the receiving unit 12 and thus into the powdery material 14 via these insert volumes 26.
[0077] As shown in FIG. 6D, the insert volumes 26 can have a connection system 27, e.g. positive engagement, which is achieved by the structuring of surfaces of the insert volumes 26 or by holes for connecting them to one another, allowing the use of a number of standard shapes, which can be combined as required. This connection system 27 can also be provided on the base plate 41 or on the sides 47 of the receiving unit 12 in order to allow the coupling of the insert volumes 26 and to avoid movements during printing and during the vibrations.
[0078] According to one example, the insert volume 26 illustrated in FIGS. 6A to 6D can be produced or printed simultaneously with the component. In this case, the manufacture of the insert volume 26 or of the insert volumes 26 can take place in layers. For example, in the case of series manufacture, the insert volume 26 could be printed in the first pass, to be precise next to the first component 10 to be manufactured. In other words, the insert volume 26 is also printed in the first pass and remains in the receiving unit 12 for all further passes. Thus, the volume 26 is solidified or sintered in the first pass around the target geometry of the component 10 in such a way that only a small region around the component geometry to be printed remains free, and the insert volume 26 then remains in the 3D printer for all further passes. This can be automated on the software side, for example by way of the control unit 30 (cf. FIGS. 1A and 1B).
[0079] FIG. 7 shows a flow chart for a method for the additive manufacture of a component 10 within a receiving unit 12 using a powdery material 14. In one step S10 of the method, the powdery material 14 is introduced into the receiving unit 12 via a feed unit 16. In a further step S20, an oscillation is applied to the powdery material 1 introduced into the receiving unit 12. In a further step S30, the oscillation is applied over a period of time to the powdery material 14 introduced into the receiving unit 12 until a predetermined distribution 50 of the powdery material 14 within the receiving unit 12 is achieved. In a further step S40, at least a part of the powdery material 14 within the receiving unit 12 is solidified after the predetermined distribution 50 of the powdery material 14 has been achieved.
[0080] The steps mentioned can be carried out in the sequence indicated. It is also possible to provide further optional steps. In a further step S31, the oscillation can, for example, be applied to the powdery material 14 introduced into the receiving unit 12 during and/or immediately after the introduction of the powdery material 14 into the receiving unit 12. In a further step S32, the oscillation can be applied to the powdery material 14 introduced into the receiving unit 12 by means of an oscillation unit 20 coupled to the receiving unit 12. In a further step S33, the oscillation can be applied to the powdery material 14. introduced into the receiving unit 12 by means of an acoustic output unit 22. In a further step S34, the oscillation can be applied to the powdery material 14 introduced into the receiving unit 12 by means of an oscillation element introduced at least partially into the powdery material 14. In a further step S35, monitoring is carried out, for example, as to whether the powdery material 14 within the receiving unit 12 has achieved the predetermined distribution 50.
[0081] In addition, it should be noted that “comprising” does not exclude other elements or steps and “a” or “an” does not exclude a multiplicity. Furthermore, it should be noted that features or steps which have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above. Reference signs in the claims should not be regarded as a restriction.
[0082] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.
