Additive Manufacturing Method

Abstract

The present disclosure relates to an additive manufacturing method. The method includes applying metallic powder in layers to a base surface. The base surface is formed in part by a base plate and in part by at least one insert arranged in a through opening in the base plate. The metallic powder layers are bonded in some region or regions by heating, whereby an object having connecting structures that are connected to the at least one insert is manufactured. After manufacture is finished, each insert is adjusted within a through opening relative to the base plate, thereby separating at least parts of the connecting structures from the insert.

Claims

1. An additive manufacturing method comprising: applying metallic powder layers to a base surface that is formed by a base plate and at least one insert arranged in a through opening in the base plate; bonding at least one region of the metallic powder layers by heating, whereby an object having connecting structures that are connected to the at least one insert is manufactured; and adjusting the at least one insert within the through opening relative to the base plate, thereby separating at least one part of the connecting structures from the at least one insert.

2. The manufacturing method as claimed in claim 1, wherein at least one insert is removed from the through opening after the separation of the connecting structures.

3. The manufacturing method as claimed in claim 1, wherein the base plate has a plurality of through openings, wherein an insert is arranged in each through opening.

4. The manufacturing method as claimed in claim 1, wherein the object is connected to the at least one insert via the connecting structures.

5. The manufacturing method as claimed in claim 1, wherein at least one insert is moved in a direction of a rear side of the base plate.

6. The manufacturing method as claimed in claim 1, wherein at least one insert is adjusted by a screw-like movement.

7. The manufacturing method as claimed in claim 1, wherein at least one insert is adjusted by a screwed joint or a bayonet joint.

8. The manufacturing method as claimed in claim 1, wherein predetermined breaking points are produced on the connecting structures and the connecting structures break when the at least one insert is adjusted.

9. The manufacturing method as claimed in claim 1, wherein the at least one insert is arranged in such a way for manufacture that each partial surface (B2), formed by an insert, of the base surface (B) is flush with a partial surface (B1) formed by the base plate.

10. The manufacturing method as claimed in claim 1, wherein the at least one insert is motor-adjusted.

11. The manufacturing method as claimed in claim 1, wherein a laser beam is used to bond the at least one region of the metallic powder layers.

12. An additive manufacturing method comprising: distributing metal powder with an application device to a base surface that is formed by a base plate and at least one insert arranged in at least one through opening defined by the base plate; moving the application device along a direction parallel to the base surface while distributing the metal powder to produce metallic powder layers; selectively bonding at least one region of each metallic powder layer by heat to produce a layer of an object having connecting structures that are connected to the at least one insert; and adjusting each insert within the through opening relative to the base plate to separate at least one part of the connecting structures from the at least one insert.

13. The manufacturing method as claimed in claim 12 further comprising lowering the base plate a distance that corresponds to a predetermined layer thickness after each layer of the object is produced until the object is manufactured.

14. The manufacturing method as claimed in claim 13 further comprising applying metallic powder to a buildup surface that is created when the base plate is lowered, wherein the buildup surface is parallel to the base surface.

15. The manufacturing method as claimed in claim 12, wherein a laser beam is used to bond the at least one region of each metallic powder layer.

16. The manufacturing method as claimed in claim 12, wherein the connecting structures are tapered such that each connecting structure defines a predetermined breaking point adjoining a corresponding insert.

17. The manufacturing method as claimed in claim 16, wherein the connecting structures break when the at least one insert is adjusted.

18. The manufacturing method as claimed in claim 12 wherein the at least one insert is adjusted by a screw joint or a bayonet joint.

19. The manufacturing method as claimed in claim 12, wherein the at least one insert is motor-adjusted.

20. The manufacturing method as claimed in claim 12, wherein the at least one insert is removed from the through opening after the at least one part of the connecting structures are separated from the at least one insert.

Description

DRAWINGS

[0045] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

[0046] FIG. 1 shows a side view of a first form of an apparatus for carrying out a method according to the present disclosure during buildup of an object;

[0047] FIG. 2 shows a side view of a base plate of the apparatus from FIG. 1 with inserts according to the present disclosure;

[0048] FIG. 3 shows a side view of a base plate with a finished object according to the present disclosure;

[0049] FIG. 4 shows a side view of a base plate and an object during separation of connecting structures according to the present disclosure;

[0050] FIG. 5 shows a side view of an object with connecting structures after separation according to the present disclosure;

[0051] FIG. 6 shows a perspective partial sectional representation of part of a base plate and of an insert from FIG. 1;

[0052] FIG. 7 shows a perspective partial sectional representation of part of a base plate and of an insert according to a second form according to the present disclosure;

[0053] FIG. 8 shows a side cross-sectional view of part of a base plate and of an insert according to a third form according to the present disclosure; and

[0054] FIG. 9 shows a perspective illustration of a base plate according to a fourth form according to the present disclosure.

[0055] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

[0056] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0057] FIG. 1 shows a first form of a manufacturing system 1, by means of which the method according to the present disclosure can be carried out. The illustration is highly schematized and, for reasons of clarity, various parts of the manufacturing system 1 have been omitted. The figure illustrates a base plate 2 having a plurality of through openings 2.1, in each of which inserts 3 are arranged. As can be seen in the detail illustration in FIG. 6, each through opening 2.1 has an internal thread 2.2, which interacts with an external thread 3.1 of the respective insert 3. The respective insert 3.1 can be screwed into a through opening 2.1 or screwed out of said opening by exerting a torque on a head 3.2 having a hexagonal cross-section (wrench surface). In the example under consideration, the inserts 3 thus have the form of hexagon-head screws. Of course, it would also be possible to use a head 3.2 having a slot, a crosshead slot, an internal hexagon or the like, for example, instead of a hexagon head 3.2. As an alternative, as shown in FIG. 8, each through opening 2.1 could have a recess 2.5 to accommodate the head 3.2, allowing the head to be recessed. When screwed in, the inserts 3 form a base surface B together with the base plate 2, wherein a first partial surface B1 is formed by the base plate 2, and second partial surfaces B2 are formed by the inserts 3. Said surfaces B, B1, B2 can be seen from FIG. 2, where it can also be seen that the second partial surfaces B2 are flush with the first partial surface B1, i.e. lie in one plane.

[0058] Metal powder 6 is applied in layers to the base surface B by an application device 5, more specifically along a buildup surface A parallel to the base surface. The application device 5 can have a kind of nozzle or valve for dispensing powder and a smoothing device, e.g. a doctor. As indicated by the double arrow, the application device 5 can be moved parallel to the buildup surface A in order to distribute powder along the entire buildup surface A. The base plate 2 is adjoined on both sides by side walls 4, which inhibits metal powder 6 from trickling away sideways. In the example under consideration, the base surface B and the buildup surface A are parallel to the horizontal H, although deviations from this are also conceivable as long as the buildup plane A encloses an angle with the horizontal H which is smaller than the angle of repose of the metal powder 6. To protect the metal powder 6 from oxidation or to protect against explosions, the parts of the apparatus which are shown are normally accommodated in a housing (not shown here), which may be filled with inert gas.

[0059] When the application device 5 has applied a layer of metal powder 6, some of the powder 6 is selectively melted by means of a laser beam 8, thereby producing a layer of an object 10 to be manufactured. The laser beam 8 is produced by a laser 7 and is directed onto an envisaged coordinate within the buildup surface A by means of a pivotable mirror 9. Here, the activation of the laser 7 and the control of the mirror 9 are performed under computer control in accordance with predetermined CAM data of the object 10. While a powder layer is being applied and partially melted, the base plate 2 with the inserts 3 remains in a fixed position along the vertical V and is then lowered by a distance which corresponds to the envisaged layer thickness. For this purpose, the base plate 2 can be mounted on a lifting device (likewise not shown here).

[0060] By means of the action of the laser beam 8, the object 10 produced is strongly heated, even if the melted powder 6 solidifies again when the action of the laser beam 8 is ended. Since effective heat transfer is possible neither to the surrounding powder 6 nor to the inert gas, it is desired that heat transfer to the base plate 2 can take place in order to avoid thermally induced deformations of the object 10. To assist this process, connecting structures 12 connected to the inserts 3 are produced in addition to a component 11, which represents the usable part of the object 10 in this example. These connecting structures 12 can be used to stabilize the object 10, but they serve primarily for better heat dissipation to the inserts 3 and, from there, into the base plate 2. Heat conduction is promoted by the fact that both the base plate 2 and the inserts 3 are manufactured from metal, e.g. steel, and by the fact that they are in close thermal contact via the threads 2.2, 3.1.

[0061] In the example under consideration, the connecting structures 12 taper in the direction of the inserts 3, thereby in each case defining a predetermined breaking point 12.1 adjoining an insert 3, at which point the connecting structures 12 may break or crack. When viewed in section, the connecting structures 12 are, by way of example, shown as truncated cones, wherein the narrow bottom side thereof is arranged on the insert side and the wider top side thereof is arranged on the component side. The predetermined breaking point 12.1 is arranged on the insert side in the illustrative form shown.

[0062] FIG. 3 shows the base plate 2, the inserts 3 and the object 10 on conclusion of additive manufacture. The excess metal powder 6 has been removed and the base plate 2 has been removed from the manufacturing system 1. As is readily apparent here once again, the object 10 is connected to the inserts 3 exclusively via the connecting structures 12, i.e. there is no direct connection with the base plate 2. The base plate comes into contact only with unmelted powder and can therefore be reused without further processing.

[0063] In order to free the object 10 with the connecting structures 12, the inserts 3 are screwed out of the base plate 2 by operating the head 3.2. This involves a screw-like movement of the respective insert 3 within the through opening 2.1. Thus, a combination of shear and tension forces acts between the insert 3 and the connecting structure 12, leading to the connecting structure 12 breaking in the region of the predetermined breaking point 12.1, while the insert 3 is screwed out in the direction of a rear side 2.3 of the base plate, said side being situated opposite the base plane B. Unscrewing can be performed in a fully automatic manner, e.g. by means of a motor-operated screwdriver arranged on a robot arm. No separating tools are involved for this purpose, and separation can be carried out exclusively from the rear side 2.3 by adjusting the inserts 3 from there. Upon separation, slight residues of the connecting structure 12 normally remain on the respective insert 3, and therefore said insert cannot be reused without being reconditioned. For a further manufacturing operation, which can take place within a short time by virtue of the efficiency of separation, new inserts 3 can be screwed into the base plate 2.

[0064] FIG. 5 shows the object 10 after separation is complete, wherein the connecting structures 12 are still connected to the component 11. They can then be separated in a conventional manner, e.g. mechanically or by spark erosion.

[0065] FIG. 7 shows a detail of an alternative form of an insert 3 and of a base plate 2, which are formed substantially as in FIGS. 1-6, although the insert 3 interacts with the through opening 2.1 via a bayonet joint. For this purpose, a groove 2.4, which interacts with a radially outward-directed extension 3.3 of the insert 3, is introduced into the through opening 2.1.

[0066] FIG. 8 shows a base plate 2 in which the through opening 2.1 has a recess 2.5, in which the head 3.2 of the insert 3 can be accommodated, said head in this case being of round rather than hexagonal design. The head 3.2 can have a slot, crosshead slot, internal hexagon, Torx or the like, for example.

[0067] FIG. 9 shows an illustrative alternative form of a base plate 2, which has a multiplicity of through openings 2.5, 2.6, which are arranged in accordance with a rectangle grid. Here, larger through openings 2.5 in each case alternate with smaller through openings 2.6. It is self-evident that the through openings 2.5, 2.6 of different sizes are provided for inserts 3 of different diameters. The base plate 2 illustrated can be used to manufacture objects 10 of many different sizes and shapes, wherein in each case only the inserts 3 in some of the through openings 2.5, 2.6 are used. That is to say that connecting structures 12 are produced in association with only some of the inserts 3, while other inserts only come into contact with unmelted powder.

[0068] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.