Additive manufacturing machine for the production of ring-shaped parts.

Abstract

The invention relates to an additive manufacturing machine (10) for depositing powder layers and selectively consolidating these powder layers, the machine (10) comprising a powder layer deposition device (18), a work surface (12), a selective consolidation zone (14), a main outer contour jacket (42) (Cex), and a secondary jacket (46) disposed inside the main jacket (42) and defining a non-manufacturing zone (48) inside the selective consolidation zone, the powder layer deposition device (18) 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 work surface (12) of the machine, and the powder spreading device (24) moves in translation above the selective consolidation zone (14) along a straight axis of movement (DR).Figure from the summary: 1.

Description

Title of the invention: Additive manufacturing machine for the manufacture of ring parts.

[0001] The present invention relates to an additive manufacturing machine by depositing layers of powder and selective consolidation of these layers of powder.

[0002] More specifically, the invention aims at additive manufacturing by depositing 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 turbojets: turbine discs, etc.

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

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

[0005] Document EP 3300819 relates to a machine for manufacturing annular parts by selective powder melting. This machine comprises concentric inner and outer annular walls, defining an annular powder deposition zone. For spreading the powder layers, the machine includes a movable powder distributor rotating about the axis of the inner and outer annular walls. This powder distributor includes a scraper extending between the inner and outer annular walls at a predetermined angle to the radial direction of the inner and outer annular walls. Due to the angle formed by the scraper with respect to the radial direction, excess powder is discharged laterally to the inner or outer side of the annular zone.

[0006] According to a first drawback, the rotary powder distribution system described in document EP 3300819 has a relatively complex kinematic design that will require numerous tests before it can be validated for use in a manufacturing cycle. For example, due to its rotational movement, the scraper speed is not uniform along its length: it is minimal at its inner end and maximal at its outer end. Furthermore, different additive manufacturing powders have different flow characteristics. Consequently, for each type of powder, 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. Furthermore, the angle of the scraper relative to the radial direction must be adjusted with each change of powder.

[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 when manufacturing parts having a hollow central part and which is easily and quickly operational.

[0008] To this end, the invention relates to an additive manufacturing machine for depositing powder layers and selectively consolidating these powder layers, the machine comprising a powder layer deposition device and a source for selectively consolidating the powder layers, the machine comprising a work surface and a zone for selectively consolidating the powder layers located in this work surface, the machine comprising a main jacket opening into the work surface through an opening defining the outer 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 build platform moving in translation between the main jacket and the secondary jacket under the effect of an actuator,and the powder coating deposition device comprising a powder distribution device and a powder spreading device, such as a roller or a squeegee, on the selective consolidation zone.

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

[0010] Advantageously, but not necessarily, the invention may 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 outer contour of the selective consolidation zone in that transverse direction, - The powder dispensing device allows a bead of powder to be carried or deposited onto the work surface between the selective consolidation zone and the powder spreading device when the latter is in a standby position located outside the selective consolidation zone; - The powder dispensing device includes a powder receiving surface that is movable relative to the work surface and the selective consolidation zone. - The powder dispensing device includes a mobile powder reservoir above the work surface, - the upper surface of the secondary sleeve's closing wall is in the same plane as the upper surface of the worktop, - The manufacturing platform includes a closed contour opening through which the secondary jacket passes. - the secondary jacket has the same shape as the main jacket in a horizontal plane, but reduced homothetically. - the secondary and main liners are cylindrical and extend in a vertical direction, - the secondary jacket and the main jacket are coaxial.

[0011] Other features and advantages of the invention will become apparent in the following description. This description, given by way of example and not limitation, refers to the accompanying drawings in which: - [Fig. 1] 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.

[0012] The invention relates to an additive manufacturing machine by depositing layers of powder and selective consolidation of these layers of powder.

[0013] Additive manufacturing by powder deposition 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 one on top of the other. The first layer of powder is deposited onto a support such as a tray, then selectively consolidated using at least one consolidation source along a first section of the part(s) to be manufactured. Then, a second layer of powder is deposited on the first layer of powder that has just been consolidated, and this second layer of powder is in turn selectively consolidated, and so on until the last layer of powder required to manufacture 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] A powder bed deposition and selective consolidation additive manufacturing machine 10 according to the invention is schematically illustrated in top view by [Fig.1].

[0016] This machine 10 comprises a work surface 12 and a selective consolidation zone 14 for the powder layers located within this work surface. The work surface 12 and the selective consolidation zone 14 are preferably located within an enclosure 16 which can be hermetically sealed. 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 includes a device for depositing powder layers 18 and at least one source for selectively consolidating the powder layers 20.

[0018] In the example shown in [Fig. 2], the machine 10 comprises several selective consolidation sources 20. This plurality of selective consolidation sources is suitable for the additive manufacturing of large parts within a large selective consolidation zone 14. Indeed, the machine according to the invention is particularly intended for the manufacture of large parts and preferably offers a large selective consolidation zone 14. Large parts are, for example, parts with an outside diameter greater than 35 centimeters and a height greater than 35 centimeters.

[0019] Preferably, each selective consolidation source 20 is a source emitting at least one laser beam capable of fusing at least a portion of a powder layer present in the consolidation zone 14. A laser source 20 includes, for example, a scanning head for moving the laser beam spot over at least a portion of the selective consolidation zone 14 and a device for managing the laser beam focusing. Each source 20 may also include a device for monitoring the emitted laser beam and / or the melt pool created by the emitted laser beam in a powder layer.

[0020] Alternatively, a selective consolidation source can also be a particle beam, such as an electron gun for example.

[0021] The powder layer deposition device 18 includes 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 allows a bead of powder to be carried or deposited on the work surface 12 between the selective consolidation zone 14 and the powder spreading device 24 when this powder spreading device 24 is in a waiting position located outside the selective consolidation zone, such as that illustrated in [Fig.1] for example.

[0023] In a first embodiment, the powder dispensing device 22 comprises at least one powder dispenser 25 and a powder receiving surface 26 movable relative to the work surface 12 and the selective consolidation zone 14 and relative to the powder dispenser 25. For example, the powder dispenser 25 It comprises a powder reservoir mounted above a screw feeder. The movable receiving surface 26 moves beneath the powder feeder 25 to receive the powder dispensed by the feeder 25, which forms a bead of powder on this movable receiving surface. The receiving surface 26 then positions itself, along 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 onto the selective consolidation zone.

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

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

[0026] In the example illustrated in [Fig. 2], the powder dispensing device 22 comprises two movable 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 with each of its movements over the selective consolidation zone 14.

[0027] In the first embodiment of the powder distribution device 22, each movable powder receiving surface 26 is mounted in a sliding recess 32 provided in the work surface. Advantageously, this recess 32 allows for the recovery of excess powder deposited during the application of a new layer of powder to the selective consolidation zone.

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

[0029] Due to the fumes created by the selective powder melting operations in the consolidation zone, the machine 10 preferably includes a device collection device 36 for fumes created by selective consolidation. This collection device 36 makes it possible to generate a fume evacuation gas flow F above the selective consolidation zone. More specifically, the evacuation gas flow F circulates, for example, between an inlet ramp 38 located on one side of the consolidation zone 14 and an outlet ramp 40 located on the other side of the consolidation zone 14. For example, the collection device 36 includes a device for generating the evacuation gas flow F and a fume filtration device (not shown in the figures) located in a circuit connected to the inlet and outlet ramps.

[0030] Advantageously, the inlet ramp 38 and outlet ramp 40 can be movable in translation between a position dedicated to selective melting (illustrated in dashed lines in [Fig.l]) where they are located closest to the selective consolidation zone and a position dedicated to the layering of the powder (illustrated in bold lines in [Fig.l]) in which they are further away from the selective consolidation zone so as not to impede the movements of the powder spreading device. .

[0031] SELECTIVE CONSOLIDATION ZONE

[0032] According to the invention, and in particular for the manufacture of large parts having a hollow central part, the machine 10 comprises a main sleeve 42 opening into the work surface 12 through an opening 44 defining the outer contour Cex of the selective consolidation zone 14, at least one secondary sleeve 46 disposed inside the main sleeve 42 and defining a non-manufacturing zone 48 inside the selective consolidation zone 14, and a manufacturing platform 50 moving in translation between the main sleeve 42 and the secondary sleeve 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 selective powder consolidation is carried out.

[0033] In a variant of the selective consolidation zone not illustrated in the figures, the machine 10 can include several secondary jackets 46 arranged inside the main jacket 42 and defining several non-manufacturing zones 48 inside the selective consolidation zone 14. In this case, the manufacturing platform 50 moves in translation between the main jacket 42 and the various secondary jackets 46.

[0034] In more detail, the main sleeve 42 extends below the work surface 12. For example, the main sleeve 42 is removably attached to the work surface 12. Each secondary sleeve 46 also extends below the work surface 12. For example, each secondary sleeve 46 is removably mounted on a support 54 attached to the machine frame 10. The main sleeve 42 and the secondary sleeve(s) 46 are removably mounted to facilitate their removal from the machine with the manufactured parts and the manufacturing platform 50, for example via the lower part of the machine.

[0035] The build 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 primary and secondary jackets. Advantageously, in addition to the actuator(s), the machine 10 may include means for guiding the build plate in translation (not shown).

[0036] According to the invention and in order to limit the consumption of powder when manufacturing large parts with a hollow central part, each secondary jacket 46 is closed at the top by a closing wall 56 flat and parallel to the working surface 12 of the machine.

[0037] In addition to the closure at the top of each secondary jacket, the powder spreading device 24 moves in translation above the selective consolidation zone 14 along a straight axis of movement DR. Coupled with the closure at the top of each secondary jacket, the straight movement of the spreading device 24 allows for easy and rapid control of the powder layering on the selective consolidation zone. Indeed, thanks to the straight movement of the spreading device, the speed of the roller or scraper of the spreading device is identical along its entire length, and thanks to the closure at the top of each secondary jacket, the formation of a powder layer occurs as if the selective consolidation zone 14 did not contain a non-production zone.

[0038] Preferably, the linear axis of movement DR of the powder spreading device 24 is horizontal. Preferably, the linear axis of movement DR of the powder spreading device 24 is perpendicular to the fume exhaust gas flow F. Preferably, the linear axis of movement DR of the powder spreading device 24 is perpendicular to the vertical axis AV of translation of the manufacturing platform 50.

[0039] SPREADING DEVICE

[0040] In order to easily and quickly control the application of the powder to the selective consolidation zone 14, the powder spreading device 24 extends in a transverse direction DT perpendicular to its linear axis of movement DR. More precisely, the roller or scraper of the powder spreading device 24 extends in a transverse direction DT perpendicular to its linear axis of movement DR.

[0041] To ensure a homogeneous powder coating 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 maximum dimension DM of the outer contour Cex of the selective consolidation zone 14 in this transverse direction DT. Preferably, and to avoid placing the inlet ramps 38 and outlet ramps 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 outer contour Cex of the selective consolidation zone 14 in this transverse direction DT.

[0042] SHIRTS AND TRAY

[0043] In a first preferred embodiment of the closure at the top of each secondary sleeve, the upper surface 58 of the closure wall 56 of a secondary sleeve 46 is located in the same plane as the upper surface 60 of the work surface 12. In this first embodiment, the upper surface 58 of the closure wall 56 of a secondary sleeve 46 and the upper surface 60 of the work surface 12 are located a few tenths of a millimeter, for example 0.5 millimeter, below the generatrix of the roller or the squeegee of the spreading device 24. This prevents the roller or the squeegee from rubbing against the upper surface 58 of the closure wall 56 of a secondary sleeve 46 and against the upper surface 60 of the work surface 12.Also, this space between the generator of the roller or scraper of the spreading device 24 and the upper surfaces of a closing wall 56 and the work surface 12 is filled with powder during the first layering of powder and it remains filled with powder until the end of manufacturing.

[0044] In a second embodiment (not illustrated), the upper surface 58 of the closing wall 56 of a secondary sleeve 46 is located very slightly above the plane of the upper surface 60 of the work surface 12, by a few tenths of a millimeter, for example. In this second embodiment, the upper surface 58 of the closing wall 56 of a secondary sleeve 46 is always located below the generatrix of the roller or the scraper of the spreading device 24.

[0045] In a third embodiment (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 a millimeter, for example. In this third embodiment, a significant thickness of powder, several tenths of a millimeter thick, must be formed by the spreading device 24 above a closing wall 56. This significant thickness of powder is intended to be achieved at the beginning of the manufacturing cycle during the first powder layering, by distributing more powder in front of the spreading device. 24 with the distribution device 22 only for subsequent powder layering. Advantageously, the first layer of powder to be consolidated in the selective consolidation zone 14 is carried out simultaneously with this significant thickness of powder.

[0046] Ideally, a secondary sleeve 46 is completely surrounded by the manufacturing tray 50. Also, the manufacturing tray 50 includes a closed contour opening 62 CF through which the secondary sleeve 46 passes. In the case where several secondary sleeves 46 are installed inside the main sleeve 42, the manufacturing tray 50 includes several closed contour openings 62 CF each through which one of the secondary sleeves 46 passes.

[0047] In the example shown in the figures, the secondary sleeve 46 has the same shape as the main sleeve 42 in a horizontal plane, but reduced homothetically. For example, the main sleeve 42 has a circular outer contour Cex, and the inner contour CI of a secondary sleeve 46 is also circular but with a diameter 1.01 to 10 times smaller, the inner contour CI of a secondary sleeve 46 corresponding to the closed contour CF of the opening 62 provided in the tray 50 for this secondary sleeve. However, the main sleeve 42 and the secondary sleeve(s) 46 may have different shapes, for example, polygonal.

[0048] For the manufacture of annular parts, i.e., parts 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 platform 50 and of superposition of the powder layers. For example, the secondary liner 46 and the main liner 42 are coaxial about the same central vertical axis ACV.

[0049] In the present invention, the main 42 and secondary 46 liners take the form of metallic walls several millimeters thick, at least 15 to 20 millimeters thick.

[0050] Advantageously, to prevent powder leakage towards the lower part of the machine 10, sealing means 64, such as gaskets, can be provided between the manufacturing platform 50 and the main 42 and secondary 46 jackets.

[0051] VARIANTS

[0052] Alternatively (not shown in the figures), the inlet ramp 38 and outlet ramp 40 of the fume collection device 36 may be located along the outer contour Cex of the selective consolidation zone 14 and the inner contour(s) CI of the secondary jacket(s). In a first example, the inlet ramp 38 is located along the outer contour Cex of the selective consolidation zone 14 and an outlet ramp 40 is located along the inner contour CI of a jacket secondary 46. In another example, an inlet ramp 38 is located along the inner contour CI of a secondary jacket 46 and an outlet ramp 40 is located along the outer contour Cex of the selective consolidation zone 14. In such a configuration, and when the selective consolidation zone 14 is annular, fume evacuation gas flows F extend radially above the selective consolidation zone 14. Also in such a configuration, the inlet ramps 38 and outlet ramps 40 are retractable, for example in the work surface 12 or at a height several centimeters above the work surface 12, so as not to hinder the movements of the powder spreading device.

Claims

1.

2. Demands Additive manufacturing machine (10) for powder layer deposition and selective consolidation of these powder layers, the machine (10) comprising a powder layer deposition device (18) and a selective consolidation source (20) for the powder layers, the machine comprising a work surface (12) and a selective consolidation zone (14) for the powder layers located in this work surface, the machine comprising a main jacket (42) opening into the work surface through an opening (44) defining the outer 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 build platform (50) moving in translation between the main jacket and the secondary jacket 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 scraper, on the selective consolidation zone (14), the machine (10) being characterized in that the secondary jacket (42) is closed at the top by a closing wall (56) flat and parallel to the working surface (12) of the machine, in that the powder spreading device (24) moves in translation above the selective consolidation zone (14) along a straight axis of movement (DR), the machine (10) further comprising a device for collecting fumes created by the selective consolidation,the collection device (36) being arranged to generate above the selective consolidation zone (14) a gas flow (F) for fume evacuation circulating between an inlet ramp (38) and an outlet ramp (40) located on either side of the selective consolidation zone (14), the rectilinear axis of movement (DR) of the spreading device (24) being perpendicular to the gas flow (F). Additive manufacturing machine according to claim 1, in which the powder spreading device (24) extends in a transverse direction (DT) perpendicular to its rectilinear axis of movement (DR).

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

4. Additive manufacturing machine according to any one of the preceding claims, wherein the powder distribution device (22) allows a bead of powder to be carried or deposited on the work surface (12) between the selective consolidation zone (14) and the powder spreading device (24) when this powder spreading device is in a standby position located outside the selective consolidation zone (14).

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

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

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

8. Additive manufacturing machine according to any one of the preceding claims, wherein the build platform (50) includes a closed contour (CF) opening (62) through which the secondary sleeve (46) passes.

9. Additive manufacturing machine according to claim 8, wherein 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, wherein 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, wherein the secondary jacket (46) and the main jacket (42) are coaxial.

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