WO2024121134A1

WO2024121134A1 - Additive manufacturing machine for manufacturing annular parts

Info

Publication number: WO2024121134A1
Application number: PCT/EP2023/084310
Authority: WO
Inventors: Albin EFFERNELLI
Original assignee: Addup
Priority date: 2022-12-08
Filing date: 2023-12-05
Publication date: 2024-06-13
Also published as: FR3142922A1

Abstract

The invention relates to an additive manufacturing machine (10) for additive manufacturing by deposition of layers of powder and selective consolidation of these layers of powder, the machine (10) comprising a device (18) for depositing layers of powder, a working plane (12), a selective consolidation zone (14), a main jacket (42) of outer contour (Cex), and a secondary jacket (46) arranged inside the main jacket (42) and defining a non-manufacturing zone (48) inside the selective consolidation zone, the device (18) for depositing layers of powder comprising a powder distribution device (22) and a powder spreading device (24), the secondary jacket (42) is closed at the top by a flat closure wall parallel to the working plane (12) of the machine, and the powder spreading device (24) moves in translation above the selective consolidation zone (14) along a rectilinear movement axis (DR).

Description

ADDITIVE MANUFACTURING MACHINE FOR THE MANUFACTURE OF ANNULAR PARTS

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an additive manufacturing machine by deposition of layers of powder and selective consolidation of these layers of powder.

[0002] More precisely, the invention aims at additive manufacturing by deposition of layers of powder and selective consolidation of large parts with a hollow central part, for example fixed parts of turbojets: casing, flow straighteners, etc.; or rotating parts of turbojet engines: turbine disks, etc.

[0003] When manufacturing parts having a hollow central part with an additive manufacturing machine equipped with a cylindrical or parallelepiped manufacturing liner, there is a large central volume in the manufacturing liner in which no part of the part is is consolidated. Consequently, this central volume is unnecessarily filled with powder.

[0004] To address this drawback, additive manufacturing machines with annular manufacturing jackets have been designed. Thanks to the annular shape of their manufacturing jacket, these machines make it possible to manufacture large parts with a hollow central part while limiting powder consumption.

DESCRIPTION OF THE PRIOR ART

[0005] Document EP 3300819 relates to a machine for manufacturing annular parts by selective melting of powder, this machine comprising an internal annular wall and an external annular wall which are concentric and delimit an annular powder deposition zone. For spreading the layers of powder, the machine comprises a powder distributor movable in rotation around the axis of the internal and external annular walls, this powder distributor comprising a scraper extending between the internal annular wall and the annular wall external by forming a predefined angle with the radial direction of the internal and external annular walls. Thanks to the angle formed by the scraper with respect to the radial direction, the excess powder is evacuated laterally towards the inner side or towards the outer side of the annular zone.

[0006] According to a first drawback, the distribution of rotating powder provided for in document EP 3300819 offers relatively complex kinematics which will require numerous tests before being able to be validated for use in a manufacturing cycle. For example, due to its rotational movement, the speed of the scraper is not identical at every point along its length: it is minimum at its inner end and maximum at its outer end. On the other hand, different additive manufacturing powders have different flow characteristics. Consequently, and for each type of powder, it is necessary to find the best compromise between the maximum speed of the scraper at its outer end and the minimum speed of the scraper at its inner end. Additionally, the angle of the scraper relative to the radial direction must be adjusted each time the powder is changed. SUMMARY OF THE INVENTION

[0007] The present invention aims to remedy these drawbacks of the prior art by proposing a configuration of an additive manufacturing machine which makes it possible to limit the consumption of powder during the manufacture of parts having a hollow central part and which is easily and quickly exploitable.

[0008] For this purpose, the subject of the invention is an additive manufacturing machine by deposition of layers of powder and selective consolidation of these layers of powder, the machine comprising a device for deposition of layers of powder and a source of selective consolidation layers of powder, the machine comprising a work surface and a zone for selective consolidation of the layers of powder located in this work surface, the machine comprising a main jacket opening into the work surface through an opening defining the external contour of the selective consolidation zone, the machine comprising a secondary jacket disposed inside the main jacket and defining a non-manufacturing zone inside the selective consolidation zone, the machine comprising a manufacturing plate moving in translation between the main jacket and the secondary jacket under the effect of an actuator, and the powder layer deposition device comprising a powder distribution device and a powder spreading device, such as a roller or a squeegee, on the zone of selective consolidation.

[0009] According to the invention, the secondary jacket is closed in the upper part by a flat closing wall parallel to the work surface of the machine, and the powder spreading device moves in translation above the zone of selective consolidation along a rectilinear axis of movement.

[0010] Advantageously but not necessarily, the invention can also provide that: - the powder spreading device extends in a transverse direction perpendicular to its rectilinear axis of movement,

- the length of the powder spreading device in the transverse direction is greater than the maximum dimension of the external contour of the selective consolidation zone in this transverse direction,

- the powder distribution device makes it possible to take or deposit a bead of powder on the work surface between the selective consolidation zone and the powder spreading device when this powder spreading device is located in a position waiting area located outside the selective consolidation zone,

- the powder distribution device comprises a mobile powder receiving surface relative to the work surface and to the selective consolidation zone,

- the powder distribution device comprises a mobile powder reservoir above the work surface,

- the upper surface of the closing wall of the secondary jacket is located in the same plane as the upper surface of the work surface,

- the manufacturing plate includes a closed contour opening through which the secondary jacket passes,

- the secondary shirt has a shape identical to the main shirt in a horizontal plane, but reduced homothetically,

- the secondary jacket and the main jacket are cylindrical and extend in a vertical direction, - the secondary jacket and the main jacket are coaxial.

DESCRIPTION OF DRAWINGS

Other characteristics and advantages of the invention will appear in the description which follows. This description, given by way of example and not limitation, refers to the attached drawings in which:

- [Fig.l] represents a schematic top view of a machine according to the invention with a first variant of a powder distribution device,

- [Fig.2] represents a schematic side view of a machine according to the invention with a second variant of a powder distribution device.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to an additive manufacturing machine by deposition of layers of powder and selective consolidation of these layers of powder.

[0013] Additive manufacturing by deposition of powder layers and selective consolidation is an additive manufacturing process in which one or more parts are manufactured by the selective consolidation of different layers of additive manufacturing powder superimposed on each other. The first layer of powder is deposited on a support such as a tray, then selectively consolidated using at least one consolidation source according to a first section of the part(s) to be manufactured. Then, a second layer of powder is deposited on the first layer of powder which has just been consolidated, and this second layer of powder is selectively consolidated in turn, and so on until the last layer of powder useful for the manufacturing the last section of the part(s) to be manufactured.

[0014] In the context of the invention, an additive manufacturing powder is preferably metallic, but can also be non-metallic.

[0015] An additive manufacturing machine 10 by powder bed deposition and selective consolidation according to the invention is schematically illustrated in top view in Figure 1.

This machine 10 comprises a work surface 12 and a selective consolidation zone 14 of the powder layers located in this work surface. The work surface 12 and the selective consolidation zone 14 are preferably located in an enclosure 16 which can be closed in a sealed manner. A wall of this enclosure 16 may include a door giving access to the work surface 12 and to the selective consolidation zone 14. The work surface 12 and the selective consolidation zone 14 are preferably located in a horizontal plane.

[0017] For the implementation of additive manufacturing, the machine 10 comprises a device 18 for deposition of layers of powder and at least one source of selective consolidation 20 of the layers of powder.

[0018] In the example shown in Figure 2, the machine 10 comprises several sources of selective consolidation 20. This plurality of sources of selective consolidation is adapted to the additive manufacturing of large parts in a selective consolidation zone 14 of large dimensions. dimensions. Indeed, the machine according to the invention is particularly intended for the manufacture of large-sized parts and it preferably offers a selective consolidation zone 14 of large dimensions. Large parts are for example parts with an external diameter greater than 35 centimeters and a height greater than 35 centimeters. Preferably, each selective consolidation source 20 is a source emitting at least one laser beam making it possible to fuse at least part of a layer of powder present in the consolidation zone 14. A laser source 20 comprises for example a scanning head making it possible to move the spot of the laser beam over at least part of the selective consolidation zone 14 and a device for managing the focusing of the laser beam. Each source 20 can also include a device for monitoring the laser beam emitted and/or the melt pool created by the laser beam emitted in a layer of powder.

Alternatively, a selective consolidation source can also be a particle beam, such as an electron gun for example.

The powder layer deposition device 18 comprises a powder distribution device 22 and a powder spreading device 24, such as a roller or a squeegee, on the selective consolidation zone 14.

[0022] Preferably, the powder distribution device 22 makes it possible to take or deposit a bead of powder on the work surface 12 between the selective consolidation zone 14 and the powder spreading device 24 when this device The powder spread 24 is located in a waiting position located outside the selective consolidation zone, like that illustrated in Figure 1 for example.

[0023] In a first variant, the powder distribution device 22 comprises at least one powder distributor 25 and a powder receiving surface 26 movable relative to the work surface 12 and to the selective consolidation zone 14 and relative to the powder dispenser 25. For example, the powder dispenser 25 includes a powder reservoir mounted above a screw dispenser. The mobile receiving surface 26 moves under the powder distributor 25 so as to receive the powder delivered by the distributor 25 which forms a bead of powder on this mobile receiving surface. Then, the receiving surface 26 is positioned with its bead of powder between the spreading device 24 and the selective consolidation zone 14 so that the spreading device 24 can spread the bead of powder on the selective consolidation zone.

[0024] In the example illustrated in Figure 1, the powder distribution device 22 comprises two distributors 25 arranged on either side of the selective consolidation zone 14 and two mobile powder receiving surfaces 26 arranged in either side of the zone of selective consolidation. Thus, the powder spreading device 24 can spread a new layer of powder during each of its movements above the selective consolidation zone.

[0025] In a second variant, the powder distribution device 22 comprises at least one powder reservoir 28 movable above the work surface 12. For example, a movable powder reservoir 28 is mounted on the spreading device 24 of powder. Preferably, and in order to deposit a bead of powder in front of the spreading device, a powder reservoir 28 is mounted movable in translation relative to the spreading device 24. The powder distribution device 22 preferably comprises an inlet of powder 30 in the enclosure 16 to replenish a mobile powder reservoir 28 with powder.

In the example illustrated in Figure 2, the powder distribution device 22 comprises two mobile powder reservoirs 28 mounted on the spreading device, one reservoir on each side of the spreading device. Thus, a bead of powder can be deposited on each side of the spreading device, and the powder spreading device 24 can spread a new layer of powder during each of its movements above the selective consolidation zone 14.

[0027] In the first variant of the powder distribution device 22, each mobile powder receiving surface 26 is mounted movable in translation in a housing 32 provided in the work surface. Advantageously, this housing 32 makes it possible to recover the powder deposited in excess during the production of a new layer of powder on the selective consolidation zone.

[0028] In the second variant of the powder distribution device 22, at least one reservoir 34 for collecting the powder deposited in excess is provided in the work surface 12. Preferably, two reservoirs 34 for collecting the powder deposited in excesses are provided, one on each side of the selective consolidation zone 14.

Due to the fumes created by the selective melting operations of the powder in the consolidation zone, the machine 10 preferably comprises a device 36 for collecting the fumes created by the selective consolidation. This collection device 36 makes it possible to generate a flow of gas F for evacuating smoke above the selective consolidation zone. In more detail, the evacuation gas flow F circulates for example between an entry ramp 38 located on a first side of the consolidation zone 14 and an exit ramp 40 located on the other side of the consolidation zone. consolidation 14. For example, the collection device 36 comprises a device for generating the evacuation gas flow F and a smoke filtration device (not shown in the figures) located in a circuit connected to the inlet and discharge ramps. exit.

[0030] Advantageously, the entry ramps 38 and exit ramps 40 can be movable in translation between a position dedicated to selective fusion (illustrated in dotted lines in Figure 1) where they are located as close as possible to the selective consolidation zone and a position dedicated to layering the powder (illustrated in strong lines in Figure 1) in which they are further away from the selective consolidation zone so as not to prevent the movements of the powder spreading device.

SELECTIVE CONSOLIDATION AREA

[0031] According to the invention, and in particular with a view to manufacturing large parts having a hollow central part, the machine 10 comprises a main jacket 42 opening into the work surface 12 via an opening 44 defining the exterior contour Cex of the selective consolidation zone 14, at least one secondary jacket 46 arranged inside the main jacket 42 and defining a non-manufacturing zone 48 inside the selective consolidation zone 14, and a manufacturing tray 50 moving in translation between the main jacket 42 and the secondary jacket 46 under the effect of at least one actuator 52. The non-manufacturing zone 48 is a sub-zone of the selective consolidation zone 14 in which no consolidation selective powder is not implemented.

[0032] In a variant of the selective consolidation zone not illustrated in the figures, the machine 10 may comprise several secondary jackets 46 arranged inside the main jacket 42 and defining several non-manufacturing zones 48 inside. of the selective consolidation zone 14. In this case, the manufacturing plate 50 moves in translation between the main liner 42 and the different secondary liners 46.

[0033] In more detail, the main shirt 42 extends below the work surface 12. For example, the main shirt 42 is removably fixed to the work surface 12. Each secondary shirt 46 also extends under the work surface 12. For example, each shirt secondary 46 is removably mounted on a support 54 secured to the frame of the machine 10. The main liner 42 and the secondary liner(s) 46 are removably mounted to facilitate their extraction from the machine with the manufactured parts and the production plate. manufacturing 50, for example via the lower part of the machine.

The manufacturing plate 50 preferably moves in translation along a vertical axis AV corresponding to the vertical direction in which the different layers of powder are superimposed. Preferably, several actuators 52 are used to move the build plate 50 relative to the main and secondary liners. Advantageously, in addition to the actuator(s), the machine 10 may include means for guiding the translation of the manufacturing plate (not illustrated).

[0035] According to the invention and in order to limit the consumption of powder during the manufacture of large parts with a hollow central part, each secondary jacket 46 is closed in the upper part by a closing wall 56 which is flat and parallel to the plane. working 12 of the machine.

In addition to closing the upper part of each secondary jacket, the powder spreading device 24 moves in translation above the selective consolidation zone 14 along a rectilinear movement axis DR. Coupled with the closure in the upper part of each secondary jacket, the rectilinear movement of the spreading device 24 makes it possible to easily and quickly control the layering of the powder on the selective consolidation zone. Indeed, thanks to the rectilinear movement of the spreading device, the speed of the roller or the scraper of the spreading device is identical over its entire length, and thanks to the closure in the upper part of each secondary jacket, the formation of a layer of powder is carried out as if the selective consolidation zone 14 did not include a non-manufacturing zone.

Preferably, the axis of rectilinear movement DR of the powder spreading device 24 is horizontal. Preferably, the axis of rectilinear movement DR of the powder spreading device 24 is perpendicular to the gas flow F for evacuating the smoke. Preferably, the axis of rectilinear movement DR of the powder spreading device 24 is perpendicular to the vertical axis AV of translation of the manufacturing plate 50.

SPREADING DEVICE

[0038] Still with a view to easily and quickly controlling the layering of the powder on the selective consolidation zone 14, the powder spreading device 24 extends in a transverse direction DT perpendicular to its axis of rectilinear movement DR . More precisely, the roller or the scraper of the powder spreading device 24 extends in a transverse direction DT perpendicular to its axis of rectilinear movement DR.

[0039] In order to guarantee a layering of the powder of uniform thickness over the entire surface of the selective consolidation zone 14, the length L24 of the powder spreading device 24 in the transverse direction DT is greater than the dimension maximum DM of the outer contour Cex of the selective consolidation zone 14 in this transverse direction DT. Preferably and in order to avoid moving the entry ramps 38 and exit 40 too far from the consolidation zone 14, the length L24 of the powder spreading device 24 in the transverse direction DT is only a few millimeters greater than the maximum dimension DM of the exterior contour Cex of the selective consolidation zone 14 in this transverse direction DT. [0040] By extending over a length L24 greater than the maximum dimension DM of the external contour Cex of the selective consolidation zone 14 in the transverse direction DT and by moving along a rectilinear movement axis DR, the device powder spreading 24 offers a layering of the powder that is easy to implement and more efficient in terms of deposition speed than a rotary powder distribution solution.

FIRERS AND TRAY

[0041] In a first preferred variant of the closure in the upper part of each secondary jacket, the upper surface 58 of the closing wall 56 of a secondary jacket 46 is located in the same plane as the upper surface 60 of the work surface 12. In this first variant, the upper surface 58 of the closing wall 56 of a secondary jacket 46 and the upper surface 60 of the work surface 12 are located a few tenths of a millimeter, 0.5 millimeter for example, in below the generator of the roller or the squeegee of the spreading device 24. This prevents the roller or the squeegee from rubbing on the upper surface 58 of the closing wall 56 of a secondary jacket 46 and on the upper surface 60 of the work surface 12. Also, this space between the generator of the roller or the squeegee of the spreading device 24 and the upper surfaces of a closing wall 56 and of the work surface 12 is filled with powder when from the first layer of powder and it remains filled with powder until the end of manufacturing.

[0042] In a second variant (not illustrated), the upper surface 58 of the closing wall 56 of a secondary jacket 46 is located very slightly above the plane of the upper surface 60 of the work surface 12, by a few tenths of millimeters for example. In this second variant, the upper surface 58 of the closing wall 56 of a secondary jacket 46 is always located below the generator of the roller or the scraper of the spreading device 24.

[0043] In a third variant (not illustrated), the upper surface 58 of the closing wall 56 of a secondary jacket 46 is located very slightly below the plane of the upper surface 60 of the work surface 12, by a few tenths of millimeters for example. In this third variant, a significant thickness of powder, of several tenths of a millimeter, must be formed by the spreading device 24 above a closing wall 56. It is planned to produce this significant thickness of powder at the beginning of manufacturing cycle during the first layering of powder, by distributing more powder in front of the spreading device 24 with the distribution device 22 than for the subsequent layers of powder. Advantageously, the first layer of powder to be consolidated in the selective consolidation zone 14 is produced simultaneously with this significant thickness of powder.

[0044] Ideally, a secondary jacket 46 is entirely surrounded by the manufacturing plate 50. Also, the manufacturing plate 50 includes an opening 62 of closed contour CF through which the secondary jacket 46 passes. In the case where several secondary jackets 46 are installed inside the main jacket 42, the manufacturing plate 50 comprises several openings 62 of closed contour CF each crossed by one of the secondary jackets 46.

In the example shown in the figures, the secondary jacket 46 has a shape identical to the main jacket 42 in a horizontal plane, but reduced homothetically. For example, the main jacket 42 has a circular exterior contour Cex and the interior contour Cl of a secondary jacket 46 is also circular but with a diameter 1.01 to 10 times smaller, the interior contour Cl of a secondary jacket 46 corresponding with closed contour CF of the opening 62 provided in the plate 50 for this secondary jacket. However, the main jacket 42 and the secondary jacket(s) 46 can take different shapes, for example polygonal.

[0046] With a view to manufacturing annular parts, that is to say having an axis of revolution, the secondary liner 42 and the main liner 46 are for example cylindrical and extend in a vertical direction DV parallel to the vertical axis AV of translation of the plate 50 and superposition of the layers of powder. For example, the secondary jacket 46 and the main jacket 42 are coaxial around the same vertical central axis ACV.

[0047] In the present invention, the main jackets 42 and secondary jackets 46 take the form of metal walls several millimeters thick, at least 15 to 20 millimeters thick.

[0048] Advantageously, to avoid leaks of powder towards the lower part of the machine 10, sealing means 64, such as seals, can be provided between the manufacturing plate 50 and the main jackets 42 and secondary jacket(s). 46.

VARIANTS

[0049] As a variant (not shown in the figures), the entry ramp 38 and the exit ramp 40 of the smoke collection device 36 can be located along the exterior contour Cex of the selective consolidation zone 14 and the or the interior contours Cl of the secondary jacket(s). In a first example, the entry ramp 38 is located along the exterior contour Cex of the selective consolidation zone 14 and an exit ramp 40 is located along the interior contour Cl of a secondary jacket 46. In another example, an entry ramp 38 is located along the interior contour Cl of a secondary jacket 46 and an exit ramp 40 is located along the exterior contour Cex of the selective consolidation zone 14. In such a configuration, and when the selective consolidation zone 14 is annular, gas flows F for evacuating smoke extend radially above the selective consolidation zone 14. Still in such a configuration, the inlet 38 and outlet ramps 40 are retractable, for example in the work surface 12 or in height several centimeters above the work surface 12, so as not to hinder the movements of the powder spreading device.

Claims

1. Machine (10) for additive manufacturing by deposition of layers of powder and selective consolidation of these layers of powder, the machine (10) comprising a device for deposition (18) of layers of powder and a source of selective consolidation (20) layers of powder, the machine comprising a work surface (12) and a selective consolidation zone (14) of the layers of powder located in this work surface, the machine comprising a main jacket (42) opening into the work surface by an opening (44) defining the exterior contour (Cex) of the selective consolidation zone, the machine comprising a secondary jacket (46) disposed inside the main jacket (42) and defining a non-manufacturing zone ( 48) inside the selective consolidation zone, the machine (10) comprising a manufacturing plate (50) moving in translation between the main liner and the secondary liner under the effect of an actuator (52), the powder layer deposition device (18) comprising a powder distribution device (22) and a powder spreading device (24), such as a roller or a squeegee, on the selective consolidation zone (14), the machine (10) being characterized in that the secondary jacket (42) is closed in the upper part by a closing wall (56) flat and parallel to the work surface (12) of the machine, and in that the device The powder spread (24) moves in translation above the selective consolidation zone (14) along a rectilinear axis of movement (DR).

2. Additive manufacturing machine according to claim 1, in which the powder spreading device (24) extends in a transverse direction (DT) perpendicular to its axis of rectilinear movement (DR).

3. Additive manufacturing machine according to claim 2, in which the length (L24) of the powder spreading device (24) in the transverse direction (DT) is greater than the maximum dimension (DM) of the external contour (Cex) of the selective consolidation zone (14) in this transverse direction (DT).

4. Additive manufacturing machine according to one of the preceding claims, in which the powder distribution device (22) makes it possible to take or deposit a bead of powder on the work surface (12) between the selective consolidation zone (14) and the powder spreading device (24) when this powder spreading device is located in a waiting position located outside the selective consolidation zone (14).

5. Additive manufacturing machine according to claim 4, in which the powder distribution device (22) comprises a powder receiving surface (26) movable relative to the work surface (12) and to the selective consolidation zone ( 14).

6. Additive manufacturing machine according to claim 4, in which the powder distribution device (22) comprises a powder reservoir (28) movable above the work surface.

7. Additive manufacturing machine according to one of the preceding claims, in which the upper surface (58) of the closing wall (56) of the secondary jacket is located in the same plane as the upper surface (60) of the plane of work (12).

8. Additive manufacturing machine according to one of the preceding claims, in which the manufacturing plate (50) comprises an opening (62) of closed contour (CF) through which the secondary jacket (46) passes.

9. Additive manufacturing machine according to claim 8, in which the secondary jacket (46) has a shape identical to the main jacket (42) in a horizontal plane, but reduced homothetically.

10. Additive manufacturing machine according to claim 9, in which the secondary jacket (46) and the main jacket (42) are cylindrical and extend in a vertical direction (DV).

11. Additive manufacturing machine according to claim 10, in which the secondary liner (46) and the main liner (42) are coaxial.